drywall mud pump invention manufacturer

Drywall mud is a paste compound of calcium carbonate composites, such as mica, talc, and silica, that is used to fill corners, crevices, gaps and cracks in and between drywall sheets, often in conjunction with paper or fiberglass-mesh drywall tape. Drywall installers screw sheets in place and use mud and tape to form a smooth surface to be painted. Mud is applied in a paste or plastic state and dries in about 20 minutes if an accelerant is used, but otherwise can take several days, depending on the weather. Various specialized tools, such as tapers, flat boxes and angle boxes are used to apply the mud evenly and efficiently.

In practice, the drywaller uses pre-mixed mud or mixes a batch of mud in a container, such as a bucket, by adding water to the powdered material. He then transfers the mud to a hawk, or hand-held mud platform, and with a trowel applies the mud to the wall. Other tools, such as the automatic taper, the flat box and the angle box, include reservoirs for containing a quantity of mud and permit the drywaller to apply the mud directly to the wall. One common tool at construction sites is a mud pump, designed to fit over the edge of a bucket and capable of transferring mud into a tool with a mud reservoir for dispensing mud onto the wall.

A disadvantage of the existing mud pump is that its configuration forces the drywaller to stand bent over in an awkward position with one hand holding the tool being filled and the other moving the pump handle. It is an objective of the present invention to configure the pump so that the drywaller may be in a position to exert better leverage on the pump handle when filling a spreading tool. It is a further objective to increase the efficiency of the pump by transferring more mud per stroke of the handle. SUMMARY OF THE INVENTION

An improved capacity mud pump is achieved by lengthening the link between the piston and the pump handle in such a way that each stroke of the handle moves the piston farther, thus transferring more mud per stroke. Ergonomics are improved by raising the pivot point of the pump handle, lengthening the link to the handle and reconfiguring the output aperture by attaching a high filler that allows the user to hold the empty tool in a position that affords better leverage in working the pump handle. The wear characteristics and mechanical resistance to pumping are improved by adding a longer pump shaft guide inside the pump head. BRIEF DESCRIPTION OF THE DRAWINGS

The configuration of a typical prior art pump is shown in FIGS. 1 and 2. Pump (1) comprises a main body tube (2), a piston (3) inside the main body tube, a pump head assembly (8), a handle (4) and a foot plate (5). In operation, the foot plate is placed outside the mud container and the main body tube is submerged in the mud.

Foot valve (6), protected by mesh screen (7), comprises the input through which mud enters the main body tube (2). Head assembly (8) includes an output aperture (9) with connection nuts (10) and an integral link base (11). Piston (3) includes piston rod (12) and piston head (13), made up of piston cup (14) and valve disc (15), that travel inside the main body tube (2).

In operation, once the pump is primed, as the handle (4) is pushed downward, pulling piston rod (12) upward, mud is drawn into the main body tube (2) and mud above the piston cap (14) is expelled through output aperture (9), which is adapted to fittings designed to fill different tools. When handle (4) is pulled upward, pushing the piston rod (12) downward, valve (15) opens and allows mud to pass above the piston, to be expelled in the next stroke.

The prior art mud pump has certain disadvantages. When the drywaller holds a tool to be filled, such as a flat box, at the pump"s output aperture, he must bend down to an awkwardly low position to mate the tool"s input aperture to the output. Typically, when the handle is halfway through a stroke in a level position, the operator has to reach 16 inches toward the pump head and 4¼ inches down to hold the empty tool. As a result, the drywaller"s other arm, which operates the pump handle, does not have an advantageous range of motion or very good leverage because his body is too close to the pump. See FIG. 5.

Another problem with prior art pumps is the stability of the pump shaft. Current pumps use a ¾ inch gland nut shaft guide in the top of the pump head. This allows the pump shaft to move horizontally in operation and puts a horizontal force on the shaft guide, causing wear on the pump cylinder, piston and shaft guide. It also requires application of more force on the handle to pump the mud.

The current invention improves the operation of a mud pump in three ways. First, the stroke of the piston is increased by increasing the length of link member (16) between the handle (4) and the link base (11). Average mud pumps known in the art are about 19½ inches high and have a piston stroke of about 4 inches. A lengthening of the link to 6 inches from the standard 4 inches causes the same piston to travel about 2 inches farther as the handle moves from its uppermost position to its lowermost.

Raising the link base by about 1 inch on the pump head, when combined with a 2 inch increase in the length of the link, has the effect of raising the pivot point of the pump handle by 3 inches. The higher location increases the difference in elevation between the operator"s handle-gripping hand and his hand that holds in place the empty tool and the output aperture. This differential distorts the body position of the operator and decreases leverage and range of motion in working the handle.

To avoid the aforesaid distortion, a high filler (40) is attached to the pump, as seen in FIG. 4. In one embodiment, shown in FIG. 7, the high filler is an S-shaped stainless steel tube with a 1 inch inside diameter, an overall length of 11½ inches, and a vertical rise of 7¾ inches between the apertures at either end of the tube. One end (41) is matched to the fitting at the output aperture (109) and the other end (42) is matched to the tool to be filled, positioned at approximately the height of the handle (104) when extended horizontally. With the high filler in place, the pump operator is able to stand more comfortably while holding the empty tool and the pump handle simultaneously during a fill operation. See FIG. 6. It has been observed that the working position is more comfortable if the high filler is mounted at a slight angle rather than vertically, as seen in FIGS. 4 and 6. Workable variants of the high filler range from an overall length of a few inches to about 20 inches.

Another improvement relates to the pump shaft. In prior art pumps, a shaft guide is provided in the top of the pump head, often a ¾ inch gland nut. This guide allows the shaft to wobble and introduces horizontal forces on the gland nut when the handle is pumped. The forces in turn cause unnecessary wear on the cylinder, piston cap and gland nut, and increase the resistance to pump motion.

The inventive design improves the pump"s durability and ease of use by effectively lengthening the shaft guide elements. A longer gland nut, 1½ inches rather than the industry-standard ¾ inch gland nut, is placed in the top of the pump head. In addition, a 1½ inch gland nut is positioned in the bottom of the pump head in the flow of the mud being pumped. This combination creates a shaft guide about 4½ inches long, decreasing wobble and more efficiently directing the force from the handle vertically. The result is an easier pumping action and reduced wear on the pump cylinder, piston cup and gland nut.

One embodiment of the invention is shown in exploded view in FIG. 3. Main body tube (102), foot valve (106) and mesh screen (107) are similar to prior pumps, as is the foot plate (105). Piston shaft (112) connects to piston cup (113) enclosing valve disc (113), making up the piston head. The top end of piston shaft (112) connects to the base (117) of handle (104) with a quick connect pin (118).

Link (116) connects handle (104) to the pump head enclosure (108) at link base (111). As previously described, link (116) is approximately 6 inches long, which is 2 inches longer than the corresponding link in prior art pumps, and link base (111) is attached to pump head housing (108) about an inch higher than in prior art pump configurations.

The upper shaft guide (123) is a gland nut attached to the head housing (108) with threaded bolts (123). Bushing liner (121) and U-cup (124) complete the upper assembly. The output aperture (109) is surrounded by a mounting bracket incorporating a pair of mounting nuts (110) that match standard tools the pump is designed to fill.

Although the invention has been described with respect to a specific embodiment, persons of ordinary skill in the art will readily understand that the inventive concepts may be applied to a variety of configurations.

{"links":[{"url":"https://www.graco.com/us/en/contractor/solutions/articles/how-to-mix-drywall-mud-for-texture-spraying.html", "anchor_text":"How to Mix Drywall Mud for Texture Spraying"},{"url":"https://www.graco.com/us/en/contractor/products/drywall-finishing-interior-texture/interior-texture-sprayers.html", "anchor_text":"Interior Texture Sprayers"},{"url":"https://www.graco.com/us/en/contractor/products/drywall-finishing-interior-texture/drywall-finishing-tools-accessories.html", "anchor_text":"Drywall Finishing Tools & Accessories"}]}

This invention is a portable drywall joint compound pump station that pumps joint compound into drywall finishing tools and facilitates cleanup at drywall construction sites.

Drywall has become a dominant material in the construction of building interiors. In particular, building interiors generally have vertical stud walls that support pre-formed drywall panels attached to the stud walls. Joints between the adjacent drywall panels are taped and finished with joint compound before painting or wallpapering. Many drywall finishing tools have been developed over the years to facilitate taping and finishing with joint compound.

One type of drywall finishing tool is disclosed in U.S. Pat. No. 2,815,142, issuing on Dec. 3, 1957. This tool mechanically applies tape and, contemporaneously, a first coat of joint compound. This mechanical tool includes a reservoir for joint compound that needs to be filled before applying the joint compound to the drywall surface. After the tape and the first coat of joint compound have been applied over the joint, a second and sometimes even a third coat of joint compound are applied. The second and third coats are typically applied using finishing tools such as a flat box or a corner angle finishing tool. Conventional flat boxes and comer angle finishing tools also need to be filled with the joint compound.

A pneumatic apparatus for applying joint compound is disclosed in Denkins U.S. Pat. No. 5,863,146, issuing on Jan. 26, 1999. This tool also needs to be filled with joint compound before applying the joint compound to the joint between adjacent panels of drywall. The Denkins apparatus is powered by compressed air that can be easily metered to effectively control the application of joint compound. Several finishing attachments, such as heads for flat joints and corners, are removably attached to the pneumatic tool.

When working with drywall finishing tools, substantial amounts of time are spent mixing joint compound, filling application tools with joint compound, and cleaning the tools. U.S. Pat. No. 5,878,925, entitled “Drywall Joint Compound Pump Workstation,” by Jeffrey L. Denkins and Steven J. Mondlock, issuing on Mar. 9, 1999, and assigned to the assignee of the present application, discloses a drywall joint compound pump workstation that is designed to accommodate these needs, as well as other needs present at drywall construction work sites. The workstation disclosed in the Denkins et al. "925 patent effectively mixes and pumps joint compound for drywall finishing tools. The pump workstation has a series of quickly interchangeable attachments and is extremely versatile. It is also designed to facilitate rinsing and cleaning of the workstation and drywall finishing tools at the work site. In its commercial embodiment, the pump workstation includes a rather large supply reservoir having an open top and a closed bottom for mixing and holding a supply of joint compound. A gravity fed pump is attached to the bottom of the supply reservoir. A transport tube is connected to the pump, and an outlet of the transport tube is positioned in the vicinity of the open top of the supply reservoir. The top of the transport tube is preferably provided with a quick-disconnect fitting so that one of several attachments can be attached to the outlet of the transport tube to facilitate the task at hand. For example, a gooseneck attachment is attached to the transport tube in order to mix and recirculate joint compound from the supply reservoir through the pump and the transport tube back into the supply reservoir. Various filling adapters are also provided at the top of the transport tube in order to fill various drywall tools, such as the mechanical tool of the type disclosed in U.S. Pat. No. 2,815,142, the pneumatic joint compound application tool as disclosed in Denkins et al. U.S. Pat. No. 5,863,146; or other tools such as flat boxes. In addition, a threaded nipple attachment is provided along with a water hose to facilitate on-site rinsing and cleaning.

In order to facilitate portability of the aforementioned workstation, the workstation is mounted on a conventional wheeled hand truck. The pump is mounted to the base of the hand truck and the supply reservoir is mounted directly above the pump so that both the pump and the supply reservoir are balanced on the hand truck. The pump is preferably a pneumatic pump that is powered by compressed air. The availability of a compressed air supply at the drywall work site is commonplace.

While the drywall joint compound pump workstation disclosed in Denkins et al. U.S. Pat. No. 5,878,925 has been commercially successful, some drywall workers feel that the station may be too expensive or too bulky for their needs. It is an object of the present invention to accommodate the needs of these drywall workers with a portable drywall joint compound pump station that is compact, reliable, and durable. The pump station should also able to fill a variety of application tools with joint compound, and facilitate the rinsing and cleaning of tools on-site.

The invention is a portable drywall joint compound pump station that uses a pneumatic pump to pump joint compound from a mud container such as a five gallon bucket or other similar container. The pneumatic pump is preferably a double diaphragm pneumatic pump. In order to use the pump station, the drywall joint compound should be pre-mixed in the container. In the preferred embodiment of the invention, the pneumatic pump is mounted to a frame having legs that support the pneumatic pump at a height above the ground such that an inlet for the pump is higher than the typical height for a five-gallon bucket. Alternatively, it may be desirable for the bottom of the legs to mount onto the container itself (see for example FIGS. 15-17).

An intake tube is connected to the pump inlet and extends downward such that the inlet port for the intake tube is positioned close to the bottom of the container when the intake tube is placed within the container (e.g., ½″-¾″ above the ground surface). In order to accommodate the suction of a consistent flow of mixed drywall joint compound through the pneumatic pump, it is important that the diameter of the intake tube be sufficiently large to avoid significant restriction of the flow of joint compound through the intake tube into the pump. Preferably, the inside diameter of the intake tube is about two inches. The pump outlet preferably faces in the same direction as the pump inlet, thereby enabling the filling of tools to occur over the open top of the container. This configuration reduces messes at the work site. In the preferred embodiment of the invention, the pump station is designed to be placed adjacent a five gallon-bucket filled with pre-mixed joint compound, such that the intake tube is located within the bucket and dips in the mixture of joint compound in the bucket. The legs for the pump station are located adjacent the bucket. The pump outlet preferably includes a quick-disconnect fitting, such as a cam lever coupling, in order to facilitate the connection and removal of various accessories such as filling tubes for application tools, filling adapters for flat boxes or corner angle finishing tools, a hose adapter for a rinsing and cleaning water hose, or a recirculation tube to direct joint compound from the pump outlet downward into the bucket.

The frame for the pump station is preferably constructed of two arch-shaped, steel members. The pneumatic pump is mounted to the arch-shaped members using a pair of mounting panels in such a manner that the pair of arch-shaped members provide four legs for the pump station, as well as looped handles above the pump. The leg portions of the arch-shaped members taper slightly outward in order to render the pump station stable as it stands on the ground (or as it is mounted to the top of a larger container or tub). The pneumatic pump is mounted substantially entirely within an imaginary peripheral surface contained within the arch-shaped members. The arch-shaped members, therefore, provide a protective cage that protects the pneumatic pump from damage when the pump station is laid on its side for transportation, or if the pump station tips over accidentally.

As mentioned, it is preferred that the pump station be designed so that the filling of tools occurs over the open top of the mud container (e.g., a five-gallon bucket). In order to accomplish this task with the joint compound application tool disclosed in Denkins et al., U.S. Pat. No. 5,863,146, a filling tube with a convoluted shape and a filling adapter at its end is removably connected to the quick-disconnect fitting at the pump outlet. A brace is provided between the front legs on the frame. The brace has a notch that supports the convoluted tube when the filling port for the application tool is inserted in the filling adapter for the convoluted filling tube. In addition, a removable mast is provided at the rear of the frame for the pump station. A support bar, preferably pivotable, is connected to the mast and supports the end of drywall application tool opposite the filling port. In this manner, the filling port is located above the open top of the mud container, and also the load on the frame remains relatively balanced while the application tool is being filled. In order to fill the mechanical tool disclosed in U.S. Pat. No. 2,815,142 a convoluted filling tube having a different configuration is used. The different configuration is needed for balancing purposes because the orientation of the filling port for the application tool is different than that disclosed in Denkins et al., U.S. Pat. No. 5,863,146. In the filling tube for the mechanical tool disclosed in U.S. Pat. No. 2,815,142, it is preferred that the location of the filling adapter on the convoluted filling tube be relatively low with respect to the pump station. Also, it is preferred that a cradle for the body of the application tool be permanently connected to the convoluted filling tube. When filling this type of mechanical tool (U.S. Pat. No. 2,815,142), it is not normally desirable to use the support brace on the mast.

Under normal operating conditions, it takes approximately 7 to 10 seconds to fill either the mechanical tool of U.S. Pat. No. 2,815,142 or the pneumatic tool of U.S. Pat. No. 5,863,146 using a pneumatic pump station designed in accordance with the invention. In order to control operation of the pump station, the preferred embodiment of the invention provides a control lever to operate a spring-actuated valve mechanism that supplies compressed air to the pneumatic pump. Also preferably, a guide member is provided for the control lever. The guide member provides a catch that holds the lever to maintain the spring-actuated valve in an open position, thereby rendering the pump in continuous operation. Continuous operation is most likely to be desirable when using the pump station for rinsing and cleaning, or even sometimes for recirculation of the drywall joint compound from the mud container (e.g. bucket or tub) through the pneumatic pump and back into the mud container (e.g. bucket or tub).

It should be apparent to those skilled in the art that the invention provides an easily portable, yet effective and versatile drywall joint compound pump station. For example, in its preferred embodiment, the pump station without attachment weighs approximately 25 pounds. In addition to being relatively light, the pump station in its preferred embodiment is stable and durable. Other advantages and features of the invention should be apparent to those skilled in the art upon reviewing the drawings and the following description thereof.

FIG. 1 is a perspective view of a portable drywall joint compound pump station constructed in accordance with a preferred embodiment of the invention.

FIG. 2 is a schematic view illustrating the pump workstation shown in FIG. 1 along with various detachable accessories for filling drywall finishing tools and rinsing and cleaning of such tools.

FIG. 3 is a side elevational view of a portable drywall joint compound pump station constructed in accordance with the preferred embodiment of the invention.

FIG. 10 is a schematic view showing the attachment of a recirculation tube to the pump outlet as in accordance with the preferred embodiment of the invention.

FIG. 11 is a schematic drawing showing the attachment of a convoluted filling tube to the pump outlet in order to fill a pneumatic tool of the type shown in Denkins et al. U.S. Pat. No. 5,863,146, as in accordance with the preferred embodiment of the invention.

FIG. 12 is a schematic view showing the attachment of a convoluted filling tube to the pump outlet in order to fill a tool of the type disclosed in U.S. Pat. No. 2,815,142, as in accordance with the preferred embodiment of the invention.

FIG. 13 is a schematic view showing the pump station with a flat box filling adapter attached to the pump outlet as in accordance with the preferred embodiment of the invention.

FIG. 14 is an expanded isometric view illustrating another embodiment of the invention in which a brace for supporting a convoluted filling tube is attached to the convoluted filling tube rather than to the frame of the pump station.

FIG. 1 shows a portable drywall joint compound pump station 10 constructed in accordance with a preferred embodiment of the invention. The pump station 10 comprises a frame 12 that supports a pneumatic pump 14 above the ground 16. The pneumatic pump 14 has an inlet 18 and an outlet 20. An intake tube 22 depends from the pump inlet 18. The intake tube 22 has an inlet port 24 located close to the ground 16 when the pump station 10 is standing on the legs 26 of the frame 12. Preferably, the inlet port 24 is located approximately ½ to ¾ of an inch above the ground surface when the pump station 10 is in operation. In operation, the portable drywall joint compound pump station 10 is preferably placed adjacent a mud container (e.g., bucket 28 in FIG. 3) containing drywall joint compound. For example, the intake tube 22 is located inside of the bucket 28 and dips into joint compound located within the bucket 28 and the legs 26 of the frame 12 are placed on the ground floor 16 outside of the bucket 28. In some circumstances, however, it may be desirable to use a larger tub or the mud container. When a larger tub is used or a mud container, it may be desirable to place the pump station 10 entirely within the tub.

Referring to FIG. 3, pre-mixed drywall joint compound located in the bucket 28 is sucked upward from the bucket 28 through the intake tube 22 and into the pump inlet 18 when the pneumatic pump 14 is operating. The pneumatic pump 14 pumps the joint compound through the pump outlet 20. The flow of drywall joint compound from the bucket 28, through the intake tube 22 and the pump 14 is depicted by arrows 21 a, 21 b, 21 c, 21 din FIG. 3.

The pump 14 is preferably a pneumatically driven, suction-type, double diaphragm pump that is manufactured by Arrow Corporation of Brian, Ohio, Model No. 66610X-X-C. It is important that the pump 14 have sufficient pumping capability to consistently pump drywall joint compound, which can on occasion can become relatively stiff as it sits in the bucket 28. Even immediately after mixing, drywall joint compound normally has a consistency such that the joint compound is not pourable. Drywall joint compound must be relatively thick for the joint compound to be useful. The thick consistency, however, provides resistance to suction through the intake tube 22 and the pump 14. The preferred pump is a one-inch, double diaphragm pump. This pneumatic pump 14 has sufficient suction power to ensure consistent operation of the pump station 10, yet it is also important that the inside diameter of the intake tube 22 be sufficiently large to allow consistent flow of the non-pourable drywall compound when the pneumatic pump 14 is operating. Preferably, the inside diameter of the intake tube 22 is approximately two inches. Testing has shown that an inside diameter of two inches is sufficient for ensuring adequate flow to the pump 14 even after drywall joint compound sits idle in the bucket 28 for a reasonable amount of time.

Referring to FIGS. 1 and 3, the outlet 20 for the pump 14 preferably faces in the same direction with respect to the pump 14 as the intake tube 22. Note that the pump outlet 20 is preferably located directly above the intake tube 22. As shown in FIG. 3 (and in FIGS. 9, 10, 11, 12 and 13), the pump outlet 20 is provided with a quick disconnect fitting 30. The quick disconnect fitting 30 is preferably a cam lever coupling such as the type commercially manufactured by Tara Products of Crawfordsville, Indiana and sold under the Banjo™ trademark. Each coupling 30 includes a pair of pivotally mounted arms 32 having eccentrically shaped cam surfaces. Each of the adapters 34 a, 36 a, 38 a, 40 a, 42 aon the accessories 34, 36, 38, 40, 42 preferably includes a circumferential rim that extends deep into the outlet coupling 30, and is secured by the cam surfaces on the arms 32 within the coupling 30 when the arms 32 are closed. The accessories 34, 36,38, 40, 42 can be easily removed by opening the arms 32 and detaching the accessory.

Referring to FIG. 5, compressed air is supplied to the pump 14 through compressed air hose 44. The compressed air hose 44 supplies compressed air to the pump 14 from a compressed air source, such as a conventional compressor which is typically available at the job site. The pump station 10 includes a nipple fitting 46 to which the compressed air hose 44 is removably attached. Compressed air is provided through the nipple fitting 46 into a compressed air manifold 48. The compressed air manifold 48 includes the inlet nipple fitting 46, a compressed air supply port 50, and a pressure regulator 52. Optionally, the compressed air manifold 48 may also include an air filter (not shown). From the pressure regulator 52, compressed air is supplied through pneumatic supply line 54 to a valve 56 having a spring-loaded control lever 58. The pressure regulator 52 is provided because compressed air pressure at job sites is often inconsistent. The pressure of the compressed air exiting from the pressure regulator 52 should be consistent with the needs for the pneumatic pump 14, and in the preferred embodiment, is approximately 60 through 90 psi.

The compressed air supply port 50 is provided with a quick release fitting 60 that enables the connection of a compressed air supply line 62 directly from the pump station 10. Such a compressed air supply line 62 is desirable, for example, when a worker desires to operate a texture gun using the pump station 10.

Referring now to FIGS. 6-8, compressed air is supplied to the pneumatic pump 14 only when it is desired to pump either joint compound or water through the pump 14. The supply of compressed air to the pump 14 is controlled by valve 56. the valve 56 has a valve body 56 that is preferably spring biased in a closed position by spring 60. More specifically, compressed air in line 54 is supplied to an elbow fitting 62. From elbow fitting 62, compressed air is supplied through supply line 64. A collar 66 is mounted around the outside of the supply line 64. Pneumatic valve 56 is installed in-line with supply line 64 downstream of the collar 66. When the body of the pneumatic valve 56 is in an open position (towards the left in FIGS. 7 and 8), compressed air is allowed to flow through lines 54 and 64 to the pump 14. When the body of the pneumatic valve 56 is moved to the closed position (as shown in FIG. 6 and towards the right in FIGS. 7 and 8), compressed air power is not supplied to the pump 14. The biasing spring 60 is mounted around the supply line 64 between the housing of the pump 14 and the movable body of the pneumatic valve 56. Because the spring is compressed, the spring 60 biases the body of the valve 56 into the closed position (i.e., towards the right in FIGS. 7 and 8). A control lever 58 is provided to move the valve body 56 and open the pneumatic valve 56. The control lever 58 includes a leveraging plate 68, a handle 70, and an intermediate stepped portion 72 connecting the handle 70 to the leveraging plate 68.

Referring now in particular to FIG. 6, the leveraging plate 68 includes a hole (not shown) through which the supply line 64 passes. The leveraging plate 68 is mounted around line 64 such that the leveraging plate 68 fits between the collar 66 and the movable body of the pneumatic valve 56. In FIG. 6, the position of the handle 70 of the control lever 58 is in the neutral or closed position. As mentioned, in the neutral or closed position, the spring 60 biases the movable body of the pneumatic valve 56 away from the pump 14 and against the leveraging plate 68 and the collar 66. A guide member 74 is provided for guiding and controlling the position of the handle 70 of the control lever 58. The guide member 74 is preferably a plate of sheet metal or the like that is fixed to either the pump 14 or the frame 12 in a fixed position. The guide member 74 contains a slot 76 through which the handle 70 of the control lever 58 is able to move in order to open and close the pneumatic valve 56. Note that it is desirable for the slot 76 to be configured and located such that the handle 70 of the control lever 58 can move either forward or backward as depicted by arrows 78 band 78 f. In addition, the guide member 74 is also provided with a notch 80 adjacent one end of the longitudinal slot 76. The notch 80 provides a catch that holds the handle 70 of the control lever 58 when the handle is moved in the direction of arrow 78 band rotated into the notch 80. The control lever 58 is sufficiently rigid so that movement of the handle 70 either forward (78 f) or backward (78 b) causes the leveraging plate 68 to push the movable valve body 56 away from the fixed collar 66 against the tension of the spring 60. When the handle 70 is locked in the fully backward position by catch 80, compressed air is supplied to the pump 14 continuously. In normal operation when the station 10 is used to fill tools, it is not preferred that the pneumatic valve 56 be locked in the open position. Locking the valve 56 in the open position is, however, preferable when cleaning or rinsing tools with water, or occasionally when it is desirable to recirculate drywall joint compound from the mud container through the pump and back into the mud container.

Referring again to FIG. 1, the frame 12 is preferably constructed from a pair of tubular arch-shaped members 80, each with a mounting plate 82 mounted horizontally between the legs 26 of the respective arch-shaped member 80. Each side of the pump 14 is bolted to the respective mounting plate 82, preferably using the same holes that are provided by the pump manufacturer for bolting together the housing of the diaphragm pump 14.

The legs 26 (i.e., the bottom portion of each arch-shaped member 80) flair outward away from each other as the legs 26 extend downward. In this manner, the legs 26 provide a stable support for the pump 14 even under heavy working conditions. Furthermore, the top portion 84 of the arch-shaped members 80 provide handles for lifting the portable pump station 10. Also, as shown in FIG. 1 and the sectional view of FIG. 4, the tubular arch-shaped members 80 and the flat mounting plates 82 preferably provide a protective cage for the other components of the pump station 10. In other words, the pneumatic pump 14, and most of the components that are permanently attached to the pneumatic pump 14, reside substantially within an imaginary peripheral surface defined by the location of the arch-shaped members 80. In this manner, the pump station 10 is protected in case it tips over, or so that it can be laid down on its side for transportation, etc.

Referring to FIG. 2, the system 10 preferably includes numerous detachable accessories including a detachable recirculation tube 34, detachable filling tubes 36, 38, detachable filling adapter 40, and a detachable water hose 42. FIG. 9 shows the water hose 42 connected to the outlet 20 of the pump 14. Water should be contained in the mud container (e.g. bucket 28) when the water hose 42 is connected to the pump 14.

FIG. 10 shows a recirculation tube 34 connected to the outlet 20 of the pump 14. A brace 86 helps to support the recirculation tube 34 against the frame 12. In order to recirculate drywall joint compound in the bucket 28, drywall joint compound is sucked into the intake tube 22 (arrows 88), up through the intake tube (arrow 90), through the pump 14 (arrows 92), and discharged through the pump outlet 20 into the recirculation tube 34 (arrow 94), and eventually returned to the bucket 28 (arrow 96).

FIG. 11 shows filling tube 36 connected to the outlet 20 of the pump 14. The filling tube 36 includes an adapter 36 bwhich is designed to fit the filling port of drywall application tool 98. Drywall application tool 98 shown in FIG. 11 is a pneumatically powered application tool as disclosed in Denkins U.S. Pat. No. 5,863,146 issued on Jan. 26, 1999. Note that the pneumatic application tool 98 has significant length. In order to hold the tool 98, the station 10 is provided with a removable mast 100. As shown in both FIGS. 1 and 11, the mast 100 includes a pivotable arm 102. A stop is provided between the mast 100 and the pivotable arm 102 so that the pivotable arm does not pivot beyond a perpendicular orientation with the mast 100. The end of the pneumatic tool 98 is supported on the pivotable arm 102 as shown in FIG. 11. The arm 102 is pivotable so that the arm 102 can be pivoted into alignment with the mast 100 when the mast 100 is not in use. The removable mast 100 is attachable to the station frame 12 by way of a receiving collar 104. A pin 106 locks the mast 100 into the collar 104.

FIG. 12 shows a different filling tube 38 connected to the outlet 20 of the pump 14. The filling tube 38 includes a filling adapter 38 bwhich is designed to accept the filling port on application tool 108. The application tool 108 shown in FIG. 12 is a drywall finishing tool as disclosed in U.S. Pat. No. 2,815,142 which issued on Dec. 3, 1957. Note that the station 10 does not use the mast to fill tool 108. Rather, the filling tube 38 itself includes a holding brace 110 to hold the body of the filling tool 108.

FIG. 13 shows filling tool 40 connected to the outlet 20 of the pump 14. Filling tool 40 is shown in FIG. 13 as filling a flat box 112. Referring to FIG. 2, it is preferred that the spout 40 bof the filling tool 40 be removable from the adapter 40A for the flat box filling tool 40. In this manner, other attachments, such as 41 aor 41 b, can be attached to the adapter 40 a. Alternatively, the adapter 40A can be used to directly fill certain tools, such as a corner angle finishing tool.

FIGS. 15-18 show two embodiments 210, 310 of the drywall joint compound pump station in which the legs 226, 326 are not supported on the ground. Rather, the legs 226, 326 are supported by the mud container 228, 328, respectively. In FIG. 15, the legs 226 on the station 210 are supported by brackets 230 mounted to an upper rim 232 of the mud container 228. Note that the brackets 230 include a set screw or some other mechanism which allows the legs 226 to be easily tightened into the brackets 230 so that the station 210 can be removed from the mud container 228. FIG. 16 is a detailed view showing screw 234 securing a leg 226 in an associated bracket 236 on the mud container 228. The configuration shown in FIGS. 15 allows the use of a mud container 228 with significantly more capacity than the five-gallon bucket shown in the embodiment described with respect to FIGS. 1-14. As with the earlier embodiment shown in FIGS. 1-14, it is still desirable that the intake opening 224 at the bottom of the intake tube 222 be located in relatively close proximity to the bottom of the mud container 228.

The embodiment 310 shown in FIG. 17 is similar to the embodiment 210 shown in FIG. 15, except that the mud container 328 in FIG. 17 includes an upper platform 330 for supporting the station 310. More specifically, foot holders 332 are affixed to the top surface of the upper platform 330. The legs 326 are set into the foot holders 332 to hold the station 310 in place on top of the upper platform 330. The intake tube 322 extends outward and downward from the pump and the platform into the mud container 328 containing drywall joint compound. As in the other embodiments, it is desirable that the bottom opening 324 of intake tube 322 be located in close proximity to the bottom of the mud container 328.

Various alternatives and other embodiments are contemplated as being within the scope of the following claims which particularly point out and distinctly claim the subject matter regarded as the invention.

Have you ever wondered about the origins of your automatic drywall taping tool in all your years as a contractor? Did it ever cross your mind to discover the history of this tool and its evolution?

With all your experience, it makes sense to know all you can know about this tool to help make your job easier. Read up on the history of the automatic drywall taping tool and learn about this device that allows you to produce precise results.

In 1939, brothers Bob and Stan Ames invented the taping tool in Georgia. They were painters and plasterers who came up with the first drywall taping tool known as the Corner Stone. The Corner Stone applied joint compound to seams using air pressure and a long hose.

The brothers started a production line of taping tools from this first invention that revolutionized the drywall industry. In 1945, the brothers invented the precursor of today’s Bazooka (automatic taper). By 1951, Bob Ames had created the first drywall boxes, nail spotters, and the automatic taper.

The standard way contractors applied their drywall was with a hawk and trowel (pan) and knife method. To tape the seams, you would use a tube full of joint compound with paper tape attached to apply both products in one motion. Naturally, this method demanded more from the contractor physically.

The next generation of drywall finishing tools that was introduced focused on being pneumatic (air) driven. These tools used compressed air to push the joint compound to the drywall. Ultimately, this method decreased the physical strain on the user’s body.

The continuous flow system was the drywall finishing tool invention that came onto the scene next. With its airless system, the finisher takes the joint compound from the bucket to the wall without going back to the pump to fill it up. This method allows the contractor to complete the application with less effort and increases efficiency.

The evolution of finishing tools over the years has undoubtedly made the job of a drywall contractor easier. At Timothy’s Toolbox, we have a selection of TapeTech taping tools, including finishing boxes, knives, and automatic tapers.

All these products make the job of the finisher more efficient. The benefits of the automatic drywall taping tool go beyond reducing the physical strain on the user’s body.

This brief history lesson about automatic drywall taping tools should increase your affection for your instrument. It has gone through some exciting development stages to make your job easier. For more information on our tools and supplies, visit our website.

This invention relates to drywall taping and texture systems, and, in particular embodiments, to a drywall taping and texture system using an automatic pneumatic bladder pump with a flip/flop logic mechanism, that may be controlled remotely by an operator.

Traditionally, in gypsum wallboard or “drywall” panel installation, sheets of drywall are nailed or screwed in place. Seams between the drywall sheets must be taped over, and the nail or screw heads must be coated with paper tape and mastic material to form a continuous wall surface. Tape and mastic material must also be applied to inside corners to form a complete wall system. The task of applying drywall tape and mastic drywall mud is generally laborious, tedious, and messy. Although inventions have made the task easier, improvement is still needed. One currently available drywall taping tool is the pedestrian mud pan and drywall knife.

With a mud pan and drywall knife, a workman manually applies drywall tape and mud. First, the workman removes a scoop of mud from a bulk container in a mud supply area and places it in the mud pan. This action is repeated until the pan is full. The workman then walks from the mud supply area to the seam that he wishes to tape. The workman then scoops a quantity of mud onto the knife, turns the knife blade towards the wall, and with a series of wiping motions, coats the seam with mud more or less uniformly. After precutting the tape, the workman lays paper tape over the seam and presses it into the mud to achieve tape attachment. He then glides the knife over the tape, forcing mud and air out from behind the tape, and begins to smooth the surface. A first coat of mud is applied to the drywall tape either at the time that the tape is applied or later, depending on the workman"s technique.

After a period of drying, another coat of mud is applied to the tape and dressed with a drywall knife, thus covering the seam with a wider coat of mud. The same steps of walking to the mud supply area, scooping out mud until the pan is full, and then walking back to the work area are repeated.

After a second period of drying, most inexperienced workmen sand the seams before applying a final coat of mud. The final coat of mud requires further walking between the mud supply and the work areas and further scooping and filling of the mud pan as before.

Complicating the situation are inside corner seams. Most occasional drywall workmen find inside corner seams the hardest and most time consuming to tape and coat of any seam. There are special knives that have a ninety degree bend to help dress these difficult seams.

To overcome the drawbacks of pedestrian drywall tape application and finishing tools such as the mud pan and drywall knife, a professional “automatic” drywall taping system has been developed by Ames Tool Company (Ames), for example, that includes a manual, lever action, fluid mud pump that fills assorted mud applicator tools from a 5 gallon bucket filled with slightly thinned drywall mud. A hand lever on the manual pump is pumped up and down to transfer drywall mud out of the bucket directly into a mud applicator tool. The mud is squirted into a slot in some tools and into other tools through a special fitting.

However, this system still requires walking between the mud supply station and the current work areas, thus wasting time and energy. Only about ninety feet of tape can be applied with the Ames taper tool before a mud refilling is required, while each roll of paper tape is about 500 feet. Only about three to four vertical seams, where each seam is about eight feet long, can be filled with the Ames box tools before more mud is required. Thus, a day"s work may require hundreds of trips for mud refills between the mud supply and work areas with the Ames drywall taping system.

Additionally, each of the tools in the Ames system takes some toll upon the user"s energy. The Ames taper tool is powered by the user forcing a wheel to turn as it contacts the wall at the end of the tool. The Ames box tool requires the operator to forcefully wipe a heavy box of mud held out on an extended handle. Each of the Ames tools mechanically disgorges drywall mud as the result of strenuous human labor. Many tasks in drywall taping with Ames type systems are thus prone to cause repetitive stress injury.

Furthermore, Ames tools require both a reservoir that holds one shot of mud and a mechanical device to manually exude the shot of mud out of the tool and onto a drywall surface. The Ames system is expensive, heavy, and manually actuated. Ames-type tools are now manufactured by several companies using similar designs that are based upon many complicated and varied machined metal parts and are thus expensive to manufacture. Those tool designs do not lend themselves to mass production of most of the parts (e.g., in plastic) for the “do it yourself” market. There is also a learning curve with Ames-type tools due to the skill required to properly operate them. In addition, there is extensive tool cleaning required after each use to ensure proper operation, and tool failures are common in the Ames system due to dried mud and mechanical failures.

The stator tube pump is well known to the drywall industry, particularly with commercial drywall texture sprayers. This type of pump has a hollow threaded internal rubber sleeve encompassing a softly threaded extended rod. As the rod is turned, fluid drywall material is forced to exit the pump under pressure into a material hose. However, the stator pump requires an electric motor or gas engine to operate. As such, it is expensive to build and costly to buy and operate. The stator pump is also very inefficient due to tremendous friction, so a large power source is required. Therefore, fluid material delivery systems using a stator pump for drywall work are an expensive way to go, with a market limited to professionals.

A second approach to spraying drywall textures is a hopper device with a gun and compressed air, which atomizes the material. This device is less expensive than pump units. However, it must be held overhead in the case of ceiling texturing, thus making its use very messy and tiring due to the stress of holding a heavy hopper full of texture overhead for extended periods. Presently, a gun on a hose is by far the preferred tool for texture application; however, such a device is currently too expensive for “do-it-yourself”, non-professional users.

An ideal system would be one in which the automatic tape functions of the Ames System are combined with the preferred spray functions of a material pump with a gun on a hose in such a way as to provide for an inexpensive solution for “do it your self” users. In such a system, the disadvantage in existing systems of carrying drywall mud back and forth will be reduced since the material is delivered by hose directly to the wall.

Examples of such a drywall taping and texture system are described in U.S. Pat. No. 6,299,686. In various embodiments discussed therein, the system includes various interchangeable tools that connect to a pump. A pump residing in a housing forces fluid drywall material through a material line. A control line hose also runs from the pump to the various tools.

The tools may include a button or trigger, allowing the user to remotely control the function of the pump by covering or uncovering an air release hole on the tool that is inter-connected to the control line to the pump. The control line outlet to the atmosphere is “normally open” at the distal, tool end. To close the control line, a plug is inserted into the air release hole to the atmosphere. Thus, opening the control line to the atmosphere releases air and resets the pump, whereas closing the control line starts the pumping action.

Additional air release mechanisms may be also be included in the pump housing itself, such as a pneumatic automatic flip flop logic switching system. This function may be performed in several ways. For example, in various embodiments of the invention of U.S. Pat. No. 6,299,686, this may be achieved electronically, with sensors and an electrical solenoid pneumatic valve, and/or mechanically, with a two-stage pressure relief valve. Both of these approaches provide for a less-expensive way of building and operating a bladder pump control than is available in previous mud pumping systems. In addition, in both cases, the device may be remotely controlled by an operator and run on a small, inexpensive air compressor of ¼ horsepower. Still, improvements may be made in the bladder pump and pneumatic system.

Other features and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, various features of embodiments of the invention.

A detailed description of embodiments of the invention will be made with reference to the accompanying drawings, wherein like numerals designate corresponding parts in the several figures.

FIG. 3a is a perspective view of the interior parts of the pump shown in FIG. 1. FIG. 3b is a partial cross-sectional view of the interior of the pump shown in FIG. 1.

FIGS. 4a and 4b are partial cross-sectional views of the interior of the pump illustrating the pump in action. FIG. 4a shows the pump during intake of drywall material, and FIG. 4b shows the pump during exhaust of drywall material.

FIG. 5a is a side, cross-sectional view of a pump cap in accordance with an embodiment of the present invention. FIG. 5b is a top plan view of the pump cap, and FIG. 5c is a perspective view of the pump cap.

FIGS. 6a-6d are views of seat and ball components of a valve in accordance with an embodiment of the present invention. FIG. 6a is a cross-sectional view of a seat in accordance with an embodiment of the present invention. FIG. 6b is a perspective view of the seat, and FIG. 6c is a top plan view of the seat. FIG. 6d is a cross-sectional view of a ball in accordance with an embodiment of the present invention.

FIGS. 8a and 8b are perspective views of a button with a hole, which is an air release mechanism in accordance with an embodiment of the present invention. FIG. 8a depicts the air release mechanism in the open position, and FIG. 8b depicts the air release mechanism in the closed position.

FIGS. 9a-9c are views of an electrical version of the pump in accordance with an alternative embodiment of the present invention. FIG. 9a is a partial cross-sectional view of the interior of the pump. FIG. 9b is an exploded perspective view of a solenoid module for controlling the electrical version of the pump. FIG. 9c is an exploded, partial cross-sectional view of an inflation sensor for electronically sensing the condition of the bladder.

FIGS. 11a-11c are views of a pneumatic tape cutter in accordance with an embodiment of the present invention. FIGS. 11a and 11b are partial cross-sectional views of the pneumatic tape cutter. FIG. 11c is a cross-sectional view of the pneumatic tape cutter.

FIGS. 12a and 12b are views of a wand tool in accordance with an embodiment of the present invention. FIG. 12a is a perspective view of the wand tool, and FIG. 12b is a partial cross-sectional view of the wand tool.

FIGS. 18a-18c are views of adapter parts that allow use of the pump with Ames Tool Company"s tools in accordance with an embodiment of the present invention. FIG. 18a shows perspective and top plan views of an Ames adapter button. FIG. 18b is a perspective view of an Ames adapter gooseneck. FIG. 18c shows perspective and top plan views of an Ames adapter box filler.

FIGS. 19a-19e are views of an universal tool fitting part in accordance with an embodiment of the present invention. FIGS. 19a and 19b are cross-sectional views of the universal tool fitting part, FIG. 19c is a perspective view of the universal tool fitting part, and FIGS. 19d and 19e are cross-sectional views of components of the universal tool fitting part.

FIGS. 21a-21e are views of a wheel with a hollow axle, which is a wheel air release mechanism in accordance with an embodiment of the present invention. FIGS. 21a and 21b are cross-sectional views of a wheel taken through the point at which air holes are located, depicting the wheel with a wheel air hole surrounding a hollow axle with an axle air hole. FIGS. 21c and 21d are cross-sectional views depicting the same wheel taken through the point at which material dispensing holes are located, depicting the wheel with multiple material dispensing holes around the same hollow axle with a material hole. FIG. 21e is a cross-sectional view of the same wheel, the cross-section taken at a plane perpendicular to those in FIGS. 21a-21d, depicting a wheel with a wheel air hole and multiple dispensing holes around a hollow axle with an axle air hole and an axle material hole.

FIGS. 22a-22b are views of an air release mechanism in accordance with an embodiment of the present invention. FIG. 22a is a perspective view of a pressure release valve situated on a housing. FIG. 22b is a perspective view of a pressure release valve in the closed position.

FIGS. 24a and 24b are partial cross-sectional views of the interior of the pump depicted in FIG. 23, illustrating the pump in action. FIG. 24a shows the pump during exhaust of drywall material, and FIG. 24b shows the pump during intake of drywall material.

FIG. 25 is a perspective exploded view of a bladder pump with pneumatic pressure relief valve in accordance with the pump depicted in FIGS. 23 and 24.

FIG. 26a is a perspective view of the interior valve core assembly parts of a pump in accordance with an embodiment of the present invention. FIG. 26b is a partial cross-sectional view of the parts of this same embodiment.

FIG. 27a is the pump at rest, 27b is the pump with bladder filling, FIG. 27c is at valve opening, FIG. 27d is at bladder discharge, FIG. 27e is at valve closing.

FIG. 33 is a drawing of a bladder pump that uses electrical sensors and a magnet on the bladder to operate, with a schematic for the sensors, electro-pneumatic valve, latching relay and power input.

As shown in the drawings for purposes of illustration, the invention is embodied in a drywall taping and texture system and a pump. In preferred embodiments of the present invention, the drywall taping and texture system utilizes the pump and various tools connected to the pump for applying drywall tape, as well as mastic or fluid drywall mud and texture, to wall surfaces. However, it will be recognized that the disclosed bladder pump may be used in other systems and with other fluids, such as water, oil, gas, or the like.

FIG. 1 shows a perspective view of a drywall taping and texture system using a pump in accordance with an embodiment of the present invention. The drywall taping and texture system preferably includes a pump 1 immersed in a container of mastic or fluid drywall material 32. The pump 1 may be supported in the container by a bucket clip 22. Referring to FIGS. 1 and 2, the pump 1 is preferably contained within a generally cylindrical housing 29. The housing 29 may be a solid shell with strength to withstand changes in pressure within the pump 1 and to support various parts of the pump 1. The housing 29 may be manufactured from a plastic extrusion, such as simple plastic drain pipe, which is cut to an appropriate length and then drilled to hold fasteners, such as screws or the like, that penetrate into various parts of the pump 1. The pump 1 may include a cap 10 attached to the housing 29 using fasteners such as a pin or bolt, or the like. The pump cap 10 may further include an air stem fitting 13 for connecting to an air compressor 28; a material line fitting 26 for connecting a preferably plastic material line 14 to the pump 1; and a control line fitting 27 for connecting a preferably plastic control line 15 to the pump 1. The material line 14 and the control line 15 may attach at their respective distal ends through another material line fitting 26 and another control line fitting 27, respectively, to a variety of tools, such as a tape applicator tool 200, a wand tool 300, a mud knife tool 400, a mud bead tool 500, a wall texture spray tool 600, or an acoustic texture spray tool 700. The pump 1 may also be attached to a variety of tools manufactured by Ames Tool Company See FIG. 18a-c and the like, through adapter parts 800, 801, and 802.

In the embodiment illustrated in FIGS. 1 and 2, the pump 1 preferably has an air gauge 24 and a pressure relief valve 25. The pressure relief valve 25 is one type of air release valve or mechanism for releasing air from the drywall taping and texture system, as will be discussed below. In alternative embodiments, the air gauge 24 and the pressure relief valve 25 may be omitted.

As shown in FIGS. 3a and 3b, the bottom of the pump 1 may include an intake orifice 8 covered with a screen 9, which may be a barrier to particulate matter that might ruin the drywall finish or plug the tool attached to the pump 10. The mesh size of the screen 9 is preferably large enough to allow passage of acoustic ceiling grains, but small enough to stop larger particles. A user may change the screen 9 to screen mud or to spray acoustic. The screen 9 may be positioned over the intake orifice 8 so that all drywall material 32 passes through the screen 9 prior to entering the pump 1.

In preferred embodiments, the pump 1 has upper and lower valves for controlling the flow of the drywall material 32. In preferred embodiments, the valves are check valves that create a one-way flow of the drywall material 32 upward through the pump 1. In the embodiment illustrated in FIGS. 3a-4b, each valve includes a seat 3 or 7 having an orifice 17 or 8, respectively, through which the drywall material 32 flows, and a member 2 or 6 for controlling the flow of the drywall material 32 through the orifice 17 or 8, respectively. See FIG. 6a-d. However, in alternative embodiments, the valves may include other components, such as flappers or the like. The lower valve is preferably formed from a lower seat 7 and a lower member or ball 6. The upper valve may be similarly formed from an upper seat 3 and an upper member or ball 2. The upper and lower members may, in some embodiments, be formed as a plug, as illustratively depicted in FIGS. 23, 24, 26 and 27.

Referring to FIGS. 3a-4b and 6a-6d, the upper and lower seats 3 and 7 may be generally shaped as a band or ring, configured to fit with the upper and lower balls 2 and 6, respectively. The seats 3 and 7 may be secured to the housing 29 using fasteners, such as screws, glue, bolts, or the like. Drywall material 32 may flow through an orifice 8 at about the center of the seat 3 or 7. The seat 3 or 7 may include a raised ring that contacts the ball 2 or 6, respectively, to separate granular elements from the drywall material 32 for proper sealing of the seat 3 or 7 and the ball 2 or 6, respectively. In alternative embodiments, the seat 3 or 7 may have other shapes.

In the illustrated embodiment, the lower seat 7 holds the screen 9. The intake orifice 8 in the lower seat 7 may alternatively have lateral vents so that pump 1 is not closed off by contact with the bottom of the container of drywall material 32.

Preferably, the upper and lower balls 2 and 6 are similar. The ball 2 or 6 is preferably made from a heavyweight material, such as iron, lead, or the like, and covered with a soft rubber or rubber-like material, such as elastromeric material or the like. The rubber or rubber-like material may help the ball 2 or 6 to seal with the seat 3 or 7 when stopping the backwards flow of the drywall material 32. By way of example, the ball 2 or 6 may be a solid material ball with a rubber coating, a rubber ball with a lead shot filling, or a spring-loaded ball. Most preferably, the ball 2 or 6 plugs the seat 3 or 7, respectively, when the drywall material 32 flows backwards, but does not stick in the orifice 17 or 8 of the seat 3 or 7, respectively. The upper and lower valves may thus create a one-way flow of the drywall material 32 upward through the pump 1.

The pump 1 may include a bladder 5 mounted within the housing 29 between the upper and lower valves. Referring to FIGS. 3a-4b and 7, the bladder 5 may be made from a resilient, rubber or rubber-like material, such as elastomeric material or the like, with a diameter smaller than the diameter of a material chamber 4 of the pump 1. When inflated, the bladder 5 could be larger than the material chamber 4, but is preferably restrained by the cylinder body pump housing 29. The rubber-like material of the bladder 5 preferably has a plastic memory and will resiliently seek from a hyper inflated state to return to its “normal size” (uninflated).

The bladder 5 may be inexpensively built and easily replaced using adjustable bands 108 that clamp a rubber cylinder between them and the bladder attachment to pump head part 115 at the top and the lower bladder part 116 at the bottom. An alternative bladder 5 forming arrangement may be provided using a plurality of bladder clips 11 which seal the top and bottom of the bladder 5.

Referring to FIGS. 4a and 4b, when the pump 1 is placed in the container filled with mastic or fluid drywall material 32, drywall material 32 preferably wants to flow into the pump 1. The lower ball 6 may be lifted out of the lower seat 7 due to greater pressure outside the pump 1 and lower pressure inside the pump 1. Resistance to the flow of the drywall material 32 from the container into the pump 1 may be minor because the lower valve resists flow in the opposite direction. Once the pump 1 is filled with drywall material 32, the bladder 5 may be inflated, resulting in positive pressure within the pump 1. This pressure may close the lower valve and lift the upper ball 2 out of the upper seat 3, forcing drywall material 32 through the material line 14 and the attached tool, and onto the work surface.

An automatic air release mechanism may be included to vent air from the bladder of the system. When the air release mechanism is open the bladder will deflate, pulling more drywall material into the housing. When the air release mechanism is closed, however, air may enter and inflate the bladder, forcing drywall material to the work surface via a control line and tool. Multiple air release mechanisms may be included in particular embodiments of the present invention, and most preferably at least one such mechanism is included (e.g., a button 50 or a trigger 147) and a pump mounted pressure relief valve.

Each tool preferably includes an air release mechanism, such as a button 50 or trigger 147, that allows the user 146 to remotely control the pump I, via the control line 15. In particular, the user may utilize the air release mechanism to deliver drywall material 32 to