Patent Publication Number: US-6712238-B1

Title: Drywall taping and texture system using bladder pump with pneumatic flip/flop logic remote control

Description:
RELATED APPLICATION 
     This application is related to U.S. patent application Ser. No. 09/113,002, filed Jul. 9, 1998, now U.S. Pat. No. 6,299,686. 
    
    
     FIELD OF THE INVENTION 
     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. 
     BACKGROUND OF THE INVENTION 
     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&#39;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&#39;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&#39;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. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     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. 1 is a perspective view of a drywall taping and texture system using a pump in accordance with an embodiment of the present invention. 
     FIG. 2 is a perspective view of the exterior of the pump shown in FIG.  1 . 
     FIG. 3 a  is a perspective view of the interior parts of the pump shown in FIG.  1 . FIG. 3 b  is a partial cross-sectional view of the interior of the pump shown in FIG.  1 . 
     FIGS. 4 a  and  4   b  are partial cross-sectional views of the interior of the pump illustrating the pump in action. FIG. 4 a  shows the pump during intake of drywall material, and FIG. 4 b  shows the pump during exhaust of drywall material. 
     FIG. 5 a  is a side, cross-sectional view of a pump cap in accordance with an embodiment of the present invention. FIG. 5 b  is a top plan view of the pump cap, and FIG. 5 c  is a perspective view of the pump cap. 
     FIGS. 6 a - 6   d  are views of seat and ball components of a valve in accordance with an embodiment of the present invention. FIG. 6 a  is a cross-sectional view of a seat in accordance with an embodiment of the present invention. FIG. 6 b  is a perspective view of the seat, and FIG. 6 c  is a top plan view of the seat. FIG. 6 d  is a cross-sectional view of a ball in accordance with an embodiment of the present invention. 
     FIG. 7 is a perspective view of bladder clips and a bladder in accordance with an embodiment of the present invention. 
     FIGS. 8 a  and  8   b  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. 8 a  depicts the air release mechanism in the open position, and FIG. 8 b  depicts the air release mechanism in the closed position. 
     FIGS. 9 a - 9   c  are views of an electrical version of the pump in accordance with an alternative embodiment of the present invention. FIG. 9 a  is a partial cross-sectional view of the interior of the pump. FIG. 9 b  is an exploded perspective view of a solenoid module for controlling the electrical version of the pump. FIG. 9 c  is an exploded, partial cross-sectional view of an inflation sensor for electronically sensing the condition of the bladder. 
     FIGS. 10 a  and  10   b  are front and back perspective views of a tape applicator tool in accordance with an embodiment of the present invention. 
     FIGS. 11 a - 11   c  are views of a pneumatic tape cutter in accordance with an embodiment of the present invention. FIGS. 11 a  and  11   b  are partial cross-sectional views of the pneumatic tape cutter. FIG. 11 c  is a cross-sectional view of the pneumatic tape cutter. 
     FIGS. 12 a  and  12   b  are views of a wand tool in accordance with an embodiment of the present invention. FIG. 12 a  is a perspective view of the wand tool, and FIG. 12 b  is a partial cross-sectional view of the wand tool. 
     FIG. 13 is a perspective view of a corner tool in accordance with an embodiment of the present invention. 
     FIGS. 14 a  and  14   b  are top and side plan views of a mud knife tool in accordance with an embodiment of the present invention. 
     FIGS. 15 a  and  15   b  are top and side plan views of a mud bead tool in accordance with an embodiment of the present invention. 
     FIGS. 16 a  and  16   b  are cross-sectional and perspective views of a wall texture spray tool in accordance with an embodiment of the present invention. 
     FIGS. 17 is a perspective view of an acoustic texture spray tool in accordance with an embodiment of the present invention. 
     FIGS. 18 a - 18   c  are views of adapter parts that allow use of the pump with Ames Tool Company&#39;s tools in accordance with an embodiment of the present invention. FIG. 18 a  shows perspective and top plan views of an Ames adapter button. FIG. 18 b  is a perspective view of an Ames adapter gooseneck. FIG. 18 c  shows perspective and top plan views of an Ames adapter box filler. 
     FIGS. 19 a - 19   e  are views of an universal tool fitting part in accordance with an embodiment of the present invention. FIGS. 19 a  and  19   b  are cross-sectional views of the universal tool fitting part, FIG. 19 c  is a perspective view of the universal tool fitting part, and FIGS. 19 d  and  19   e  are cross-sectional views of components of the universal tool fitting part. 
     FIGS. 20 a - 20   c  are partial cross-sectional views of an universal spray head part in accordance with an embodiment of the present invention. 
     FIGS. 21 a - 21   e  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. 21 a  and  21   b  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. 21 c  and  21   d  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. 21 e  is a cross-sectional view of the same wheel, the cross-section taken at a plane perpendicular to those in FIGS. 21 a - 21   d , 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. 22 a - 22   b  are views of an air release mechanism in accordance with an embodiment of the present invention. FIG. 22 a  is a perspective view of a pressure release valve situated on a housing. FIG. 22 b  is a perspective view of a pressure release valve in the closed position. 
     FIG. 23 is a perspective view of the interior parts of a pump in accordance with an embodiment of the present invention. 
     FIGS. 24 a  and  24   b  are partial cross-sectional views of the interior of the pump depicted in FIG. 23, illustrating the pump in action. FIG. 24 a  shows the pump during exhaust of drywall material, and FIG. 24 b  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. 26 a  is a perspective view of the interior valve core assembly parts of a pump in accordance with an embodiment of the present invention. FIG. 26 b  is a partial cross-sectional view of the parts of this same embodiment. 
     FIG. 27 a  is the pump at rest,  27   b  is the pump with bladder filling, FIG. 27 c  is at valve opening, FIG. 27 d  is at bladder discharge, FIG. 27 e  is at valve closing. 
     FIG. 28 is a perspective view of a pneumatic pressure relief valve in accordance with the pump depicted in FIGS. 26 and 27 a-e.    
     FIG. 29 is a fluid valve in accordance with an embodiment of the present invention. 
     FIG. 30 is a drawing of the pump in use showing an operator and a small compressor 
     FIG. 31 is a perspective drawing of a manifold cartridge with bladder assembly being inserted into the hollow cavity of the pump. 
     FIG. 32 is a drawing of the under side of the cap manifold as it attaches to the cartridge manifold showing the valve core assembly as it inserts into the valve cavity. 
     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. 
     FIG. 34 is a chart showing  4  described methods of creating an active valve core which flips abruptly to open or close. FIG. 34 a  shows a closed valve with clip, FIG. 34 b  show a closed valve with clip, FIG. 34 c  shows a valve with a changing vector spring in the closed position, FIG. 34 d  is closed, FIG. 34 e  is a cylinder with grooves that catch on the o-rings of the valve core, FIG. 34 f  is closed, FIG. 34 g  is a magnetically closed valve core, and FIG. 34 h  is the magnetic valve core in the open position. 
     FIG. 35 a  is a sectional view of a texture gun showing a universal hose connector and trigger assembly. FIG. 35 b  is a perspective view of the gun with universal hose connector in place. FIG. 35 c  shows a universal hose connector being inserted into the hollow gun body and the hose set. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     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. 18 a-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. 3 a  and  3   b , 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. 3 a - 4   b , 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. 6 a-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. 3 a - 4   b  and  6   a - 6   d , 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. 3 a - 4   b  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 . 
     As shown in FIGS. 3 a - 5   a , an airway  18  in the cap  10  may connect a pressure relief valve  25 ; a control line fitting  27  that is in turn connected to a control line  15 ; an air stem fitting  13  that is in turn connected to the air compressor  28 ; and the bladder  5  via the air stem  12 . Air flow communication may thus be established among these parts. 
     Referring to FIGS. 4 a  and  4   b , 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 the work surface as needed and to control an air release valve or mechanism remotely located on the pump  1  (i.e., when an air release mechanism included on the tool is continually sealed, a second automatic air release mechanism on the housing may be forced to open). FIGS. 8 a - 8   b ,  21   a - 21   e ,  22   a - 22   c  and FIG. 35 a  illustrate four types of such tool related air release mechanisms. 
     As illustrated in FIGS. 8 a  and  8   b , an air release mechanism may be a button  50  with an air release hole  51  at about the center of the button  50 . The user may open and close the air release mechanism by alternatively uncovering and covering the hole  51 , respectively. This type of air release mechanism may be directly connected to the tool. 
     Referring to FIGS. 21 a  and  21   b , a wheel air release mechanism may include a hollow axle  504  with a radial air hole  63  and a wheel  503  with a radial air hole  508 . As the wheel  503  is rolled along the work surface, the wheel  503  preferably rotates around the axle  504 . When the radial air hole  63  in the axle  504  is aligned with the radial air hole  508  in the wheel  503 , the wheel air release mechanism may temporarily open. Otherwise, when the radial air hole  63  in the axle  504  is not aligned with the radial air hole  508  in the wheel  503 , the air release mechanism is preferably closed. The wheel air release mechanism may also be directly connected to the tool. 
     Referring to FIGS. 22 a - 22   c , an air release mechanism may be a pressure relief valve  25  connected to the pump housing  29 . The pressure relief valve  25  may include a pull ring  31 , a valve core  34 , and a valve body  33 . The pressure relief valve  25  may also include an added compression spring  30  inserted over and surrounding the valve core  34 , to dampen closing to thus expand the range of pressure variation during which pressure relief valve  25  remains in the open position. The pressure relief valve  25  preferably opens momentarily when the bladder  5  inflates to a maximum air pressure level, and the pressure relief valve  25  preferably closes (FIG. 22 b ) when the bladder  5  deflates to a minimum air pressure level. Absent spring element  30 , or another similar mechanism, pressure relief valve  25  may open when bladder  5  reaches a maximum air pressure level and may close once the pressure drops slightly below this maximum level. Thus, in a preferred embodiment, spring element  30  possesses sufficient mechanical and elastic properties such that pressure relief valve  25  opens at a maximum air pressure level of approximately 80 psi, and remains open until the pressure drops to a minimum pressure level of approximately 40 psi. This same preferred pressure relief valve  25  may close at a pressure level of approximately 60 psi when spring element  30  is not included therein. A two stage air release regulator (not shown) which opens at 80 psi and closes at 10 psi may be used but is much more expensive than the modified pressure relief valve  25 , with a simple spring  30 . 
     The trigger  147  may be used on a number of various tools to release air which controls the pump. The trigger best shown on FIG. 35 a  shows a rubber air seal washer  162  which is attached to the under side of the trigger  147  such that as the trigger is pulled back by the user operator  146 , the air flow from the control line  15  is selectively held to remotely start pump action. 
     Therefore, in preferred embodiments, each tool has a button or trigger  147 , for remotely controlling the pump  1  via the control line  15 . When the user presses the button  50 , or pulls the trigger, the normal release of air at the tool is stopped and air release at the pump  1 . The default condition of the pump bladder is deflated and the control valve default is closed. Pressure then builds up in the control line  15  and causes the bladder  5 , to inflate, thus forcing drywall material  32  through the upper valve and out of the pump  1 , through the material line  14  and the tool, and onto the work surface. After a surge of a certain volume of drywall material  32 , the user may reduce the air pressure by releasing air at the tool by releasing the trigger preferably included therein. The bladder  5  quickly deflates upon the release of air through the button  50  or trigger  147 . The resulting partial vacuum formed by the shrinking bladder  5  refills the material chamber  4  of the pump  1  with drywall material  32  through the lower valve. Subsequent inflation of the bladder  5  forces drywall material  32  through the upper valve, as previously discussed. 
     When a more continuous flow of drywall material  32  is desired, a pressure relief valve may be additionally included such that the user may continuously hold down the trigger  147  on the tool. This may cause the pressure within the bladder  5  to rise until the maximum air pressure level of the pressure relief valve is reached. At that point, the pressure relief valve preferably opens, deflating the bladder and drawing fresh drywall material into the housing. The pressure relief valve preferably closes once pressure drops to a minimum air pressure level, causing the bladder to again inflate and force drywall material to the work surface. Notably, a trigger  147 , if included on the tool, need not be released for this continuous, cyclic action of the device, sometimes referred to as a “flip flop” action controlled by pneumatic logic. 
     Where periodic, user-controlled extrusions of drywall material onto a work surface are desirable, a trigger may be sufficient as a sole air release mechanism in the tool. However, in alternate embodiments, such as the mud bead tool  500  depicted in FIGS. 15 a - 15   b , the additional inclusion of a second air release mechanism in the tool may allow air to periodically be released from the bladder even while the aforementioned button is depressed, thereby cyclically refilling the pump housing with drywall material as the bladder deflates with each release of air from the additional air release mechanism. This feature allows the tool to be used continuously, without the user having to release the button on the tool at particular time intervals to refill the housing with drywall material. This is particularly advantageous when the tool is one where a substantially consistent flow of drywall material is desired, as opposed to a periodic extrusion. In this latter embodiment, the trigger may need only be released when the user desires to terminate the extrusion of drywall material from the tool altogether. In a most preferred embodiment of the system used with a mud bead tool, three air release mechanisms may be included: a button  50 , or trigger  147 , on the tool as a pressure relief valve, and a wheel air release mechanism as well. 
     FIGS. 9 a - 9   c  illustrate an electrical version of the pump  1  in accordance with an embodiment of the present invention. An air compressor  28  may be mounted within the pump housing  29  and connected to the bladder  5 . An inflation sensor may include a first sensor element  41 , preferably a magnet, attached to the bladder  5 , and a second sensor element  42 , preferably a reed switch, attached to the housing  29 . The inflation sensor may determine the inflation state of the bladder  5 . When the inflation sensor determines that the bladder  5  is deflated (e.g., when the first and second sensor elements are separated by a distance sufficient to result in minimal magnetic force therebetween), the air compressor  28  is preferably turned on to inflate the bladder  5 . When the inflation sensor determines that the bladder  5  is inflated (e.g., when the first and second sensor elements are sufficiently near one another to result in substantial magnetic force therebetween), the air compressor  28  is preferably turned off. The air compressor  28  may be pneumatically controlled with a solenoid module  40  or electrically controlled. 
     As shown in FIG. 9 a , the pump  1  may include a secondary exhaust valve with a material exhaust orifice  16 , connected to the material line fitting  26  and the material line  14 . The secondary exhaust valve may further include a secondary check ball  19 , a seat  20 , and a chamber  21 , which support the material line fitting  26 . This secondary valve may be advantageous where the drywall material or other fluid utilized with the present invention has particles suspended therein that might prevent the valve member from seating properly in the orifice. The inclusion of a secondary valve thus provides an added protection against undesirable backflow of material. 
     The set of tools that may be used with the pump  1  includes drywall mud, tape, and texture application and finishing devices. Each tool preferably connects to the material line  14  and the control line  15 . Referring to FIGS. 19 a - 19   e , a universal hose/tool fitting part  900  may be used with the tools, where appropriate. The universal fitting part  900  is preferably made using an injection molding process. The universal fitting part  900  may form part of the handle, the material line fitting  901 , the control line fitting  902 , a high pressure air fitting  904  and the control line orifice  903  on a wand tool  300 , a mud knife tool  400 , a mud bead tool  500 , a wall texture spray tool  600 , and an acoustic texture spray tool  700 . 
     Referring to FIGS. 20 a - 20   c , a universal spray head part  1000  may be used with the two spray tools: the wall texture spray tool  600  and the acoustic texture spray tool  700 . The universal spray head part  1000 , in combination with a universal tool fitting part  900  and a short section of PVC pipe, may form a wall texture spray tool  600 . The universal spray head part  1000 , in combination with a universal tool fitting part  900  and a section of PVC pipe, may form an acoustic texture spray tool  700 . 
     As shown in FIGS. 10 a  and  10   b , the tape applicator tool  200  may be used to hold, cut, and apply drywall tape and mud. The tool  200  preferably connects to the material line  14  and control line  15  via fittings  201  for material and fitting  202  for control air. The tape applicator tool  200  may have a cavity that holds a supply of drywall tape  206  and an area to advance and cut off the tape  204 . The tool  200  may also have a material line that feeds the drywall material  32  into a wetting chamber as it flows out of the tool  200  onto the work surface. The tool  200  may further include a base plate  203  to enclose the tool and a set of tape rollers  207 . The tape applicator tool  200  may have a metering wheel to retrieve drywall material  32  from the pump  1  according to the distance that the tool  200  is moved along the work surface. As illustrated in FIGS. 11 a  through  11   c , a pneumatic tape cutter  220  may also be added to the tape applicator tool  200  for cutting the drywall tape  204 . 
     Referring to FIGS. 12 a  and  12   b , the wand tool  300  may be used to apply drywall mud to seams. The tool  300  may be a hollow, elongated tool with threads  301  on the distal end, material and control line fittings  307  and  308 , and a control button  306 . Referring to FIG. 13, a corner tool  320  may be attached to the threaded end  301  of the wand tool  300  via a threaded end  311  of the corner tool  320 . The corner tool  320  may be used to deliver drywall material  32  into corners through a hole  310 . The corner-shaped blades  309  may finish the corners as the tool  320  is slid back and forth over the corner seam. 
     Referring to FIGS. 14 and 14 b , the mud knife tool  400  may be used for dispensing and dressing coats of mud. The tool  400  may include a broad knife blade  401  and a smaller knife blade  402  mounted next to the broad knife blade  401 . The tool may also have a handle  404 , material and control line fittings  406  and  407 , and a control button  405 . The mud valve  403  is preferably activated when the blades  402  and  401  are flexed against the work surface while the trigger  405  is pulled. 
     As illustrated in FIGS. 15 a - 15   b  and  21   a - 21   e , the mud bead tool  500  may be used to measure a distance rolled and to apply a bead of mud for other tools. The tool  500  may include an elongated hollow body  506 , material and control line fittings  501  and  502 , a control button  505 , and a wheel  503  on the distal end of the tool  500  that is rolled upon the work surface. As depicted in FIG. 21 c , when the wheel  503  is rolled upon the work surface and the control button  505  is depressed, drywall material  32  preferably flows through the hollow axle  504 , through axle material hole  71 , and finally out the distal end of mud bead tool  500  through dispensing holes  507 . As shown in FIG. 21 d, when axle material hole  71  is not aligned with one of dispensing holes  507 , drywall material is preferably not extruded to the exterior surface of the wheel  503 . Notably, material may be present on the outer surface of the wheel  503  even at times when it is not being extruded thereto, since this material may have been pumped to the outer surface of the wheel while the holes  71  and  507  were previously aligned. 
     As depicted in FIG. 21 a , when wheel air hole  508  in wheel  503  is momentarily aligned with axle air hole  63  in hollow axle  504 , air  65  is preferably released from mud bead tool  500 , causing the bladder  5  to at least partially deflate, and drywall material  32  to flow into the pump  1  from the container. However, during periods when wheel air hole  508  and axle air hole  63  are not aligned, air is preferably not released through the end of mud bead tool  500 . The resulting effect is periods of pressurization and quick periods of depressurization as the wheel  503  is rolled along a work surface. Thus, when there is but one radial air hole in each of axle  504  and wheel  503 , as illustratively depicted in FIGS. 21 a  and  21   b , air may be released only once per revolution of the wheel  503 . The number of holes in axle  504  and wheel  503  may be varied, as appropriate for particular applications, though in preferred embodiments there is one axle air hole  63  and one wheel air hole  508 . Similarly, multiple material holes  71  may be included in axle  504  in alternate embodiments of the instant invention, though in the preferred embodiment, there is but one material hole  71 . 
     In preferred embodiments employing mud bead tool  500 , drywall material  32  and air  65  simultaneously flow through hollow axle  504 , however, in such preferred embodiments, the two substances are not mixed together. As depicted in FIG. 21 e , hollow axle  504  preferably contains two interior cavities: an air cavity  76  and a material cavity  75 . The air cavity  76  is preferably in fluid communication with the control line of tool  500  such that air may flow through the system, from the pump to the wheel air hole  508  or other air release mechanism (e.g., the control button  505  on the handle of the tool  500 ). Similarly, material cavity  75  is preferably in fluid communication with the material line of mud bead tool  500  such that drywall material  32  may flow through the system, from the pump to a dispensing hole  507 . 
     A tape roll holder  509  that supports a roll of drywall tape  204  may be attached to the mud bead tool  500  to form a tape applicator tool. A pneumatic cutter  320  may also be attached to the mud bead tool  500 . 
     In addition to the tools described above, the pump  1  may be used with tools manufactured by the Ames Tool Company. See FIG. 18 a-c  To employ these tools, the control line  15  may be replaced with an adapter button  800 , and the material line  14  may be replaced with an adapter gooseneck  801  and an adapter box filler part  802 . 
     In an alternative embodiment of the instant invention, as depicted in FIGS. 23-28, a pneumatic pressure relief valve may be included in the drywall taping and texture system as an air release mechanism. The pneumatic pressure relief valve utilizes flip flop pneumatic logic to regularly maintain two states: fully open and fully closed, corresponding to progression from inflated and deflated bladder states, respectively. In preferred embodiments, the transition between the open and closed states of the pneumatic pressure relief valve is fast, owing in part to the valve preferably including a flip flop effect clip  128 . This fast, preferably spring-loaded transition may prevent the valve from freezing in a position between its two regular states, open and closed. 
     The pneumatic pressure relief valve may include a valve core  101 , which is preferably a hollow plug fitted with one or more O-rings  103 , about its outer circumference, to provide an airtight fit of the valve core within the valve hollow chamber  126 . The lower end of the valve core stem  129  is preferably solid, though a small hole  130  may be bored there through to accommodate a steel leader  114 . The valve core  101  may include at least one orifice  104  through its side, which allows air to vent from the interior of the bladder  127  to the exterior of the system when the valve is in the open position. Most preferably, the valve core  101  includes two or more such orifices  104  disposed opposite one another. In a most preferred embodiment, the valve core  101  also includes a circumferential steel ring or washer  105  about the exterior surface of its lower end that may interact with a flip flop effect clip  128 . 
     The valve core  101  may be affixed to a closing tube or closing rod  109 , which is preferably a hollow member that supports the valve core  101  by the valve core rod  107  and holds the valve core  101  in proper alignment within the hollow valve chamber  126 . The interior of the valve core  101  is preferably in fluid communication with the atmosphere such that air may pass from the interior of the pump head, through the at least one orifice  104 , when the valve core is in the open position. Once air reaches the interior of the pump head, it may travel through the closing tube  109  and the bladder attachment to the pump head part. The valve core  101 , valve rod assembly is preferably slidably disposed within the hollow valve chamber  126 , such that the valve may be readily opened by sliding the assembly  101 / 107  down, relative to the valve chamber  126 , or closed by sliding the assembly  101 / 107  up, relative to the valve chamber  126 . 
     A closing rod  109  may further be included within the bladder wall  127  of the pump. The lower end of the closing rod  109  is preferably secured to the lower bladder part  116 , and the upper end preferably accommodating a shelf member  143  that is in mechanical contact with a closing spring  110 . Most preferably, closing spring  110  forcefully contacts the valve core  101  only upon closing the discharge of air from the bladder  5 . A leader attachment  111  may be secured to the closing rod  109  near the lower end of the closing rod  109 . A spring attachment cable  112  may connect the leader attachment  111  to an opening spring  113 , and a steel leader  114  may further connect the opening spring  113  to the valve rod  107  and thus the valve core  101 . The steel leader  114  may pass through the interior of the closing spring  110 , and may further pass through a small hole  106  bored through the lower end of the valve core rod  109  to affix the steel leader  114  thereto. 
     A flip-flop effect clip  128  may be included in the pneumatic pressure relief valve. The flip flop effect clip  128  may include both an upper groove  141   a  and a lower groove  141   b  configured to receive a single corresponding circumferential ring  148  disposed on the exterior surface of the valve core  101 . When the pneumatic pressure relief valve is in the fully open position, the circumferential ring  148  preferably resides in the lower groove  141   b . When the pneumatic pressure relief valve is in the fully closed position, the circumferential ring  148  preferably resides in the upper groove  141   a . The flip flop effect clip  128  may aid in the transition of the pneumatic pressure relief valve between valve states (i.e., from the fully closed to the fully open position, and the reverse), by increasing the level of force required to effect this change. The clip positions resist change until spring tension becomes unstoppable and the clip flips back to allow a valve state change. 
     For example, to effect a transition in valve state from fully open to fully closed, not only must the force of air pressure flowing through the valve be overcome, but the friction force provided by the interlocking of the lower groove  141   b /circumferential ring  148  must be overcome as well. This heightened force requirement may equate to a greater initial velocity of the valve core  101 /valve stem  107  assembly relative to the valve chamber  126  upon closure of the valve. This initial velocity may be further increased by the inclusion of a closing spring  110 . The energy stored in the closing spring  110  will increase as the spring is compressed between the assembly.  101 / 107  and the rigid closing tube  109  during deflation of the bladder  5 . Thus, when the assembly  101 / 107  begins to close, the energy stored in closing spring  110  may translate to faster movement of the assembly  101 / 107 . The greater velocity preferably results in a reduced likelihood of the valve reaching only a partially closed state. 
     Conversely, by way of example, to effect a transition in valve state from fully closed to fully open, the interlocking force of the upper groove  141   a /circumferential ring  143  must be overcome in conjunction with the force of elevated air pressure inside the bladder  5  relative to atmospheric pressure. Furthermore, an opening spring  113  may be included, and the energy stored in the opening spring  113  may increase as the spring is stretched between the closed assembly  101 / 107  and the leader attachment  111  during inflation of the bladder  127 . Thus, when the assembly  101 / 107  begins to open, the energy stored in opening spring  113  may translate to increased movement of the assembly  101 / 107 . This heightened force requirement and inclusion of an opening spring  113  may result in a greater initial velocity of the assembly  101 / 107  relative to the valve chamber  126  upon opening, preferably resulting in a reduced likelihood of the valve reaching only a partially open state. 
     To accommodate the pneumatic pressure relief valve, a valve stem rod  107  and a series of interlocking manifolds is preferably included in the pump head housing. The valve stem rod  107  and closing tube may be included to provide an means for the pneumatic pressure relief valve and the elements that operate with the valve that preferably reside within the bladder wall  127  (i.e., spring attachment cable  112 , opening spring  113 , steel leader  112 , closing rod  109 , and closing spring  110 ) to function together without sacrificing the preferred airtight nature of the bladder  5 . As such, the valve rod preferably reaches from within the bladder  5  at its lower end to within the interlocking manifolds at its upper end, and is most preferably mounted to the pump by way of the bladder attachment to the pump head part  115  with an adjustable hose band. The inclusion of interlocking manifolds may be desirable as the manifolds may be cast separately and combined to form the single pump head cartridge unit. In a most preferred embodiment, there are three interlocking manifolds: a valve manifold  122 , a cartridge manifold  121 , and a cap manifold  120 . The interlocking manifolds may connect to one another by any appropriate means, including snap fittings or simple male-female friction fittings or glue, and most preferably prevent the mixing of drywall material with the compressed air that drives the system. The lower end of the system may be constructed as in other embodiments of the instant invention (i.e., a lower valve including a seat  118  with an orifice  119  and a member  117  that mates therewith to prevent backflow of drywall material). The member may have a soft washer  145  mounted thereon to facilitate a proper fluid seal with the beveled upper edge  144  of the seats  131  and  118 . 
     A fluid valve manifold  122  may include a valve that is similar to those described in alternate embodiments above (i.e., an upper valve including a seat  131  with an orifice  132  and a member  133  that mates therewith to prevent backflow of drywall material). However, in alternative embodiments, the valve may include other components, such as flappers or the like. A most preferred valve includes a seat  131  and the member  133  is a plug. 
     A cartridge manifold  121  may interlock on its lower end with a valve manifold  122  and on its upper end with a cap manifold  120 . Most preferably, the cartridge manifold  121  has an O-ring  123  disposed about its outer circumference to create a seal between the cartridge manifold and the interior of the hollow pump housing. This may prevent the leakage of drywall material along the outer portion of the cartridge manifold  121  and, subsequently, the top of the pump. 
     A cap manifold, see FIG. 32,  120  may include an air chamber  148  that provides gaseous communication among an air intake fitting  134 , a control line  13 , the bladder  5  and the local atmosphere via the valve. See FIG. 5 a -FIG. 5 c . The control line  13  may be connected to a tool, as discussed above. Similarly, the cap manifold  120  may include a material line fitting  136  that connects to a material line that is also connected to a tool, as discussed above. A snorkel hose  137  may be connected to the exterior valve outlet  138  such that the entire pump may be submerged in drywall material without risk of either introducing drywall material into the valve or percolating air through the material upon release of such air from the valve outlet  138 . 
     Embodiments of the present invention are directed to an improved drywall taping and texture system as shown in FIG. 30, wherein an improved bladder pump is employed which obviates, for practical purposes, the limitations in prior systems. In one aspect, an automatic bladder pump allows mud on demand to make drywall taping and texturing easier. Additionally, a pneumatic, automatic flip flop logic switching system may include an air-release mechanism that operates pneumatically, as opposed to electronically or mechanically, with a magnetic valve core assembly. 
     The ideal function for a bladder pump is to have the bladder fill relatively slowly but discharge quickly to allow a more-or-less continuous flow of fluid. Flexible material hoses tend to expand under pressure creating an expansion chamber which allows the material to continue to flow, when the upper material valve closes briefly to allow the pump to refill with material, thus smoothing out surges in the material flow. When filling with air, the bladder displaces fluid trapped within the space between upper and lower one-way fluid valves and forces it through the upper one way valve exiting the pump. As the bladder quickly discharges air from a hyper inflated state, the bladder&#39;s resilient reduction to its original size creates a partial vacuum which refills the pump body with fluid vacuumed upwards through the lower fluid valve. When a control valve is sensitive to, and controlled by, the bladder state, the pump operates at maximum cycle speed and efficiency. Most current bladder pumps use expensive, often inefficient, time-delay devices to fill and discharge the bladder, which is a major complication and disadvantage of prior bladder pumps. 
     In a preferred embodiment, the control system for a bladder pump may be a device that is powered, sequentially in each cycle, by a number of forces, including: the effect of a set of strong magnets opposing an alternative set of strong magnets; the energy exerted between two distal points on the bladder wall; powered first by bladder expansion by way of an air compressor introducing more air into the system than is being discharged by the system, by the elastic memory action of the rubber bladder, and also a set of opposing springs which alternately store and release kinetic energy. 
     Energy to operate the control system is taken from the power required to compress air, which is used to expand the bladder. Some energy is taken from the forceful contraction of the bladder reducing in size from a hyper inflated state when a control valve or control line is opened to the atmosphere. In both expansion and contraction of the bladder, some energy is saved by opposing springs which allow a sudden release of kinetic energy that flips the pneumatic control valve open or jerks it closed to create a fully mechanical flip flop air release control mechanism. 
     This system utilizes a device including a continuous air supply feeding into a manifold cavity and a trapped sliding valve core, wherein the latter is capable of sealing automatically when the bladder state becomes deflated and thus ready to be refilled, and flipping back open to discharge air as the bladder reaches the set maximum inflation limit. When this series of actions is repeated, a continuous cycle of inflation and deflation is created. The cycle is managed by an automatic bladder pump control system that is free of electronics in this mode. The pump in this preferred embodiment uses only compressed air to operate. 
     Referring to FIG. 28, the sliding pneumatic valve core  101 , is attached to a heavy steel washer  105 , which is suspended between two sets of strong permanent magnets, an upper set of magnets  124 , mounted adjacent to the valve core chamber  102 , magnets each set in small cavities in the cap manifold and an opposing set of magnets  125 , mounted below the valve chamber which are also set in the cartridge manifold part which also has such small cavities for magnets to be mounted or glued in place. The opposing sets of magnets  124  and  125 , tend to decisively select either a fully open or fully closed valve state by both pulling upon the steel washer  105  mounted to the valve core  101 . The magnets also tend to resist the valve core  101  changing position while at rest, until a sufficient carrying force is gathered by stressed springs  110  and  113 , to cleanly push the valve core  101  all the way to engage the other set of magnets, which are also pulling the valve core  101  to firmly capture it. 
     The trapped valve core  101  is aligned by the valve core chamber  102  and by a valve core rod sliding within a rigid closing tube member  109 , the tube  109  being attached to a distal point on the bladder whereby, as the discharged bladder  5 , elastically reduces in size, the bladder shrinkage forces the rigid closing rod  109 , to move upwards against a closing spring  110 , and suddenly push the valve core  101  into a closed position. The bladder  5 , then begins to inflate. When fully inflated to the flip open point, the enlarging bladder  5  pulls the closing cable to pull the valve core  101  towards the open position which causes it to flip back to the open position, thus creating a continuous cycle of inflation and deflation. 
     Remote control of the pump is accomplished at the distal end of a control line hose  15 . An operator can start and stop the pump action at any time by using a pneumatic trigger  405 , or button  50 , that normally releases air into the atmosphere or selectively holds air in the control line hose  15 , which is interconnected to the interior of the pump head assembly  149 . 
     In a second embodiment, a similar flip flop effect is created by using electrical reed switches  150 , controlled by a magnet  151 , mounted on the rubber bladder wall  127 , using an electric current to open or close an electrically actuated pneumatic control valve  152 , to operate the bladder pump,  1 . Here, two reed switches  150  are disposed as bladder condition sensors, one of which is mounted on the interior surface of the pump body cylindrical housing  29 , and the other reed switch is mounted at the inside center of the bladder,  5 . One or more magnet(s) are mounted on the rubber bladder wall  127 , which align with the opposing sensors, to act in combination as sensors and a switch activator. A latching electrical relay  153 , which is hooked up with wires to an electrical power supply  154 . Both magnetic reed switches  150 , are wired to control power to the relay&#39;s actuation coil. The relay  153 , is also wired to a normally closed electrically powered pneumatic solenoid valve  152 ,, which parts in combination, create a flip flop effect, which controls a bladder pump&#39;s action. The remote control action of an operator  146 , can start or stop the pump action at any time by way of a trigger  405 , or button  50 , to distally open or close the control line hose  15 , to release compressed air into the atmosphere. Control may also be effected by using an electrical control switch  155 , that would also open the electrical solenoid valve  152 , upon the user&#39;s demand. 
     In a third embodiment, a pressure relief valve  25  that is interconnected to the air way  18 , within the pump head assembly  149 , and the outer atmosphere, which pressure release valve  25  may be dampened by an added spring  30 , to close more slowly to allow more air to discharge before resetting, thus to again fill the bladder Ideally a two stage relief valve (not shown), may open at a high pressure limit and close at low pressure limit is mounted at the same position as  25 . Should the control line hose  15 , be opened by the operator  146 , remotely, the default condition is that the bladder  5 , deflates and is ready to refill with air and again pump fluid material  32 , as soon as the control line hose  15  is closed. 
     An additional embodiment is that the control valve core  101  is held in either of two positions by way of a spring loaded clip  22  mounted near the control valve chamber,  102 . The resilient clips hold the valve core by a steel washer mounted on the valve core, at fully open and at fully closed until sufficient force in the closing and opening springs builds up to effect a flip open or closed. FIG. 34 a depicts the valve clip arrangement, here described, showing the valve closed. FIG. 34 b  shows the same valve in the closed position. 
     Another embodiment of the valve is when a spring or pair of springs is set to rotate to various vectors to favor a fully open or fully closed position of the valve core where the spring is oriented to follow the moving valve core. See FIG. 34 c  and FIG. 34 d . One end of the spring is loosely secured to the valve core cavity and the other end of the springs are loosely attached to the valve core. The compression springs are therefore less compressed when the valve core is fully open or fully closed. This approach works in conjunction with the closing spring and opening spring device of the preferred embodiment which carries the valve core through the full movement of the core. This embodiment is shown in FIG. 34 c  closed and FIG. 34 d  in the open position. 
     Another embodiment uses groove on the valve core wall that traps a cylindrical ring member is shown in FIG. 34 e  in the closed position and in FIG. 34 f  in the open position. The O rings on the valve core act as the cylindrical ring to catch on grooves in the valve cylinder wall. While this is not the preferred embodiment, this mode can be made to work with the closing spring and opening spring as previously described, offer sufficient power to effect flipping the valve to the opposite position. 
     The preferred embodiment of the valve core switching device is opposing magnets. FIG. 34 g  and FIG. 34 h  show the preferred embodiment using strong magnets that oppose a second set of strong magnets pulling a steel washer mounted to the trapped sliding valve core. FIG. 34 g  shows the valve closed and FIG. 34 h  shows the valve open. 
     According to a preferred embodiment of the present invention, a drywall taping and texture system for pumping drywall mastic material from a container filled with the drywall mastic material to a work surface includes a pump housing  29 , a small air compressor  28 , or air supply to operate the pump  1 , interchangeable tools for applying and dressing the drywall mastic material upon the work surface, a hose set consisting of; a material line hose,  14  and pump control line hose  15 , a third hose  158 , is a high pressure air supply from a second larger air compressor (also not shown) which is required for some tools, an inflatable bladder  5  (e.g., made of rubber or similar elastic material  127 ), a pneumatic pressure control system, and an airway  18 . 
     It is noted that one large air compressor may be used with a regulator to supply both a small flow of compressed air to run the pump and the remaining larger air flow is used for the tools that require a lot of air. 
     The pump housing  29 , is either partially or fully immersed in a container filled with slightly thinned drywall mastic material  32 , and the small air compressor&#39;s  28 , air supply hose is, connected to the pump head assembly  149 . 
     The bladder  5 , and pump head assembly  149  may be inserted (as a removable cartridge) into a the hollow cylindrical pump housing  29 , which housing includes the lower material check valve  118  and intake screen  9 . See FIG.  31 . The pump head assembly  149 , supports an “O” ring  123 , that allows an air tight pneumatic fit with the interior wall of the pump housing  29 . A bolt  139 ,may be passed through two adjacent holes  157 , in the pump housing  29  and also pass through a matching passage  142 , in the cartridge manifold  121  section of the pump head  149 , passage  142  is located above the large “O” ring  123 , to secure the pump head and bladder assembly securely in place during use. A butterfly retaining nut  140 , holding the bolt  139 , is removed to allow the bolt  139 , to be extracted by the user to allow the bladder and pump head assembly to be removed as a single cartridge unit for cleaning. 
     The material hose  14 , control line hose  15 , and a separate high pressure air line  158  are all connected between the pump head and the various tools such that there is material and air flow communication, respectively, therebetween. The bladder  5  is mounted within the pump housing  29  between upper  131  and lower  118 , one-way fluid valves for controlling the flow of the drywall mastic material  32 . The airway  18 , connects the air compressor  28 , the control line  15 , the bladder  5 , and the pneumatic pressure relief valve, such that there is continuous air flow communication therebetween. 
     When the pneumatic control valve is closed and the control line hose is open to the atmosphere, the pump is in the ready mode. The operator then closes the control line orifice on any attached tool, which orifice is normally open and continuously releases air into the atmosphere. This works as a trigger mechanism that is pulled to stop the outflow of air at the tool. As a result, the bladder inflates, such that drywall mastic material in the sealed pump housing is pumped through the upper one-way valve, through the material line, and through any hollow dressing tool to the work surface. When the pneumatic pressure relief valve flips opens automatically at the preset fill limit, or when the operator opens the control line at a distal tool, the bladder deflates such that drywall mastic material in the container is pumped upwards through the lower valve into the pump housing by way of a partial vacuum that causes the bottom material valve to open and the upper material valve to close. 
     Part of the air release mechanism consists of a stiff hollow tube  109 , that is attached at one distal point within the bladder  5 , and extends through the interior of the bladder to a proximal point into the head of the pump. See FIG. 26 a  and FIG. 26 b . A valve core rod  107  slides freely inside the hollow tube  109 , keeping both rod and tube in substantial alignment. An air release valve core  101 , is mounted on the top end of the rod  107 . The valve core&#39;s opposing dual hold and release mechanism may be any of the following: the valve core has a heavy steel washer  105  mounted under it which is attracted magnetically to two opposing sets of strong magnets  124  and  125 , mounted within the head of the pump, there may be resilient clips  128 , grooves  141  and ridges  143 , a one  25  or two stage air release valve  156 , an electro-pneumatic valve  152 , or vector changing spring(s) see FIGS. 34 c  and  34   d.    
     As air is constantly introduced into the pump head  149 , when the air release mechanism closes, the bladder  5 , hyper-inflates such that drywall mastic material  32  in the pump housing  29  is pumped through the upper valve  131 , the material line  14 , and an attached tool to the work surface. When the air release mechanism on any tool opens, the bladder  5  deflates such that drywall mastic material  32 , in the container is pumped through the lower valve  118 , into the pump housing  29 , thus refilling it. The bladder  5 , then returns to a ready state. 
     FIGS. 19 a-e  show a common connection system for texture guns using the system. FIG. 16 a  and  16   b  show a gun with a button  50  using the universal connection system of FIG.  19 . FIG. 17 shows a ceiling texture gun also using the universal connection system of FIG.  19 . FIG. 35 a , FIG. 35 b  and FIG. 35 c  show another texture gun design that includes a trigger  147 , that selectively plugs the control line  15 , to manage the pump system. Both of the above gun designs also provide for a material line  14  attachment and can be connected to a high pressure air line  158 , for proper atomization of sprayed textures. In particular embodiments of the present invention, all the various drywall mud dressing tools further include a pneumatic button  50 , or trigger  147 , for remotely controlling the pump. The air release orifice on an attached tool is an extension of the air release orifice of the control line hose which may extend through the universal hose fitting  900 , of the drywall system. 
     In other embodiments of the present invention, each of the upper  132  and lower valves  118 , for controlling the flow of the fluid drywall mastic material  32 ,(which may include particulate matter in suspension) includes a raised beveled rim  144 , on the seat lip, defining an orifice  119  and  132 , through which the drywall mastic material flows. See FIG.  29 . The orifice in each of the valve seats selectively accepts a plug member  116  and  132 , having a matching flat surface (which flat surface may be covered with a soft washer  145 ) for sealing the flow of the fluid drywall mastic material through the orifice. When the member  116  or  132  mates with a seat, a seal is formed to block the flow of the drywall mastic material backwards through the orifice. When the member moves in a direction transverse to the seat, flow of the drywall mastic material through the orifice is allowed. 
     In a preferred embodiment of the invention, as depicted in FIG. 29, a valve plug  117  mates with a seat  118  to block an orifice  119 , and a ridge  144  is included on the seat  118 . The ridge  144  may facilitate the movement of particles suspended in the drywall material to either side of the ridge  144  upon closing of the valve, thus preventing the plug  117  from improperly mating with the seat  118  (i.e., preventing particles from being lodged between the plug  117  and the seat  118 ). A soft washer  145  may be mounted on the plug  117  In yet other embodiments of the present invention, the pump housing further includes a screen mounted at the bottom thereof for filtering excessively large particles out of the drywall mastic material or texture which might plug the material line. 
     A set of interchangeable drywall texture spray application guns and drywall tape finishing tools may be alternatively attached to the universal hose fitting  1000 , and used with the drywall taping and texture system. A second industrial design for a universal tool fitting is shown at FIG. 35 a -FIG. 35 c . Such tools include: a paper tape applicator tool with a pneumatic tape cutter feature for applying muddy drywall tape to a drywall work surface; a wand applicator tool for putting a bead of mud down on flat seams and in corners; a corner finishing tool attachment for placing a bead of mud upon an inside corner seam while glazing mud upon a strip of paper tape; a mud knife tool for dispensing and dressing coats of mud on flat surface seams; a box tool also for coating flat seams; a wall texture spray gun  600 , with an adjustable nozzle; and an acoustic texture spray tool head, a universal extension handle that supports various attachments. A set of adapter parts that allow use of the pump with Ames tools may also be attached to and filled with the pump. 
     In another embodiment of the present invention, a drywall taping and texture system for pumping drywall mastic material from a container filled with the drywall mastic material to a work surface includes a pump housing, a tool for applying the drywall mastic material to the work surface, material and control lines, an inflatable bladder, an inflation sensor, a control unit, a pneumatic solenoid control valve and an air compressor. The pump housing is either partially or fully immersed in the container filled with the drywall mastic material. The material and control lines are connected between the pump housing and the tool such that there is material and air flow communication, respectively, therebetween. The bladder is mounted within the pump housing between upper and lower valves for controlling the flow of the drywall mastic material; 
     Part of the inflation sensor is coupled to the bladder for determining when the bladder is inflated and when the bladder is deflated. The air compressor is connected to the control line and the bladder such that there is flow communication therebetween. When the inflation sensor determines that the bladder is fully deflated, the air release solenoid is activated to close and the bladder inflates such that drywall mastic material in the pump housing is pumped through the upper valve, the material line, and the tool to the work surface. When the inflation sensor determines that the bladder is fully inflated, the air valve is opened and the bladder deflates such that drywall mastic material in the container flows through the lower valve into the pump housing. 
     A further possible embodiment is a system using two magnetic sensors which control an electrical relay, which controls a pneumatic valve, which controls the pump. See FIG.  33 . One, normally closed, magnetic reed switch  150  is mounted in the center of the bladder to sense a magnet mounted on the bladder when the bladder is discharged, and a second, normally open, magnetic reed switch is mounted on the pump cylinder wall to sense the bladder being full. The relay is wired to trip a pneumatic valve open when the bladder wall approaches pump wall and to re-close when the bladder wall reaches a point near the center of the bladder. The control line will reset the bladder to the ready and discharged state at any time. 
     When short bursts of material are required, the operator closes the control line but not long enough to reach the fill limit and trigger automatic discharge. This is the logic for “Burst Mode” (Chart No. 1 below). On the other hand, when the operator wants a continuous cycle for a more or less steady flow of fluid material he closes the control line and keeps in closed until he opens the control line to cause the bladder to reset to Ready at any point in the cycle. This is “Auto Cycle Mode” (Chart No. 2 below). Drawing numbers in the first column refer to the drawings  27   a-e . 
     
       
         
           
               
            
               
                   
               
               
                 Flow Chart of Pneumatic Flip Flop 
               
               
                 Logic Control System - Chart No. 1 
               
            
           
           
               
               
               
               
               
               
               
            
               
                 Drawing 
                 Cycle 
                 Bladder 
                   
                 Control 
                   
                 Fluid 
               
               
                 # 
                 # 
                 State 
                 Valve 
                 Line 
                 Logic 
                 Flow 
               
               
                   
               
               
                 27a 
                 1 
                 Ready 
                 Closed 
                 Open 
                 Static Closed 
                 No 
               
               
                 27b 
                 2 
                 Fills 
                 Closed 
                 Closed 
                 Static Closed 
                 Yes 
               
               
                 27c 
                 3 
                 Fill to Limit 
                 Closed 
                 Closed 
                 Static Closed 
                 Yes 
               
               
                 27b 
                 3 
                 Disc/control 
                 Closed 
                 Open 
                 Static Closed 
                 Yes 
               
               
                 27a 
                 1 
                 Ready 
                 Closed 
                 Open 
                 Static Closed 
                 No 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
            
               
                   
               
               
                 Flow Chart of Pneumatic Flip Flop 
               
               
                 Logic Control System - Chart No. 2 
               
            
           
           
               
               
               
               
               
               
               
            
               
                 Drawing 
                 Cycle 
                 Bladder 
                   
                 Control 
                   
                 Fluid 
               
               
                 # 
                 # 
                 State 
                 Valve 
                 Line 
                 Logic 
                 Flow 
               
               
                   
               
               
                 27a 
                 1 
                 Ready 
                 Closed 
                 Open 
                 Static 
                 No 
               
               
                   
                   
                   
                   
                   
                 Closed 
               
               
                 27b 
                 2 
                 Fills 
                 Closed 
                 Closed 
                 Static 
                 Yes 
               
               
                   
                   
                   
                   
                   
                 Closed 
               
               
                 27c 
                 3 
                 Fills to 
                 Closed 
                 Closed 
                 Static 
                 Yes 
               
               
                   
                   
                 Limit 
                   
                   
                 Closed 
               
               
                 27d 
                 4 
                 Flip Open 
                 Open 
                 Closed 
                 Flip open 
                 Slows 
               
               
                 27d 
                 5 
                 Rapid 
                 Open 
                 Closed 
                 Stay open 
                 Slows 
               
               
                   
                   
                 Discharge 
               
               
                 27e 
                 6 
                 Discharge 
                 Close 
                 Closed 
                 close 
                 Be- 
               
               
                   
                   
                 Limit 
                   
                   
                   
                 gins 
               
               
                   
                   
                 tripped 
               
               
                 27b 
                 7 
                 fills 
                 Closes 
                 Closed 
                 Static 
                 Yes 
               
               
                   
                   
                   
                   
                   
                 Closed 
               
               
                 27c 
                 3 
                 fills to limit 
                 Closed 
                 Closed 
                 Static 
                 yes 
               
               
                   
                   
                   
                   
                   
                 Closed 
               
               
                 27a 
                 1 
                 Ready 
                 Closed 
                 Open 
                 Static 
                 no 
               
               
                   
                   
                   
                   
                   
                 Closed 
               
               
                   
               
            
           
         
       
     
     One complete pneumatic cycle of the pump in this preferred embodiment depicted in FIGS. 23 and 24 may begin with the introduction of compressed air to the pump head through the air intake  134 . The introduction of compressed air is continuous whenever the pump is in use or in the ready mode. The pressure within the system may be regulated by a user of the system remotely at the distal end of the control line selectively discharging air through a tool attachment or holding air at the tool attachment, as discussed above. Irrespective of the mechanism that initiates a higher pressure in the pump head and the bladder  5 , the bladder  5  preferably expands both radially and axially. Axial bladder expansion most preferably causes the lower bladder part  116  to migrate away from the upper bladder attachment to pump head part  115 . Correspondingly, the leader attachment  111  may pull on the spring attachment cable  112 , stretching the opening spring  113  and pulling on the steel leader  114 . The steel leader may pull on the valve core  101 , forcing the pneumatic pressure relief valve to abruptly pop open into the fully open position, once the requisite force level is met to overcome the additional friction provided by the mating of circumferential ring  143  and upper groove  129 . Air is then preferably released from the interior of the bladder  127  to the local atmosphere, through the valve stem  130 , the at least one orifice  104  and hollow center of the valve core  101 , through the valve tube  107 . Release of air preferably causes the bladder  127  to return to its initial shape, the bladder  127  preferably being sufficiently elastic so as to have a memory of this initial shape and a mechanical propensity to return thereto. 
     Thus, the lower bladder part  116  preferably migrates axially toward the upper bladder attachment to the pump head  115  upon deflation. Correspondingly, the shelf member  143  of closing rod  107  may press on the closing spring  110 , which may press on the valve core  101 , and force the pneumatic pressure relief valve into the fully closed position once a sufficient amount of air has been evacuated from the bladder assembly  5 , and the requisite force level is met to overcome the additional friction provided by the mating of circumferential ring  143  and lower groove  1 . The next cycle may then begin, with compressed air being introduced into the pump. 
     In an alternative embodiment of the present invention, as depicted in FIGS. 26-28, the pneumatic pressure relief valve may be included at a point at or near the top of the housing. In this most preferred embodiment of the present invention, the pneumatic pressure relief valve operates in substantially the same fashion as described above. Further included in this embodiment may be an opening cable  114 , connected via an hole in the closing rod  106 , at its lower end to the lower bladder part  116 , and at its upper end to the valve rod  107  through an attachment hole. Most preferably, a shelf member  143  is attached to the top of the valve rod at the bottom of the valve core  101 . The valve rod may pass through the interior of the closing spring  110 . Cable may further pass through a small hole bored through the lower end of the valve rod  107  core to affix the opening cable members thereto. The valve rod preferably resides at least partially within closing rod  107 , such that the two rods may move independent of one another while staying aligned. Most preferably, a closing rod hole is bored through the end of closing rod  107 , such that steel leader  114  may pass there through, preferably being operable connected to valve rod at one end and to opening spring  113  at the other end. 
     One complete pneumatic cycle of the pump in this most preferred-embodiment depicted in FIGS. 26-27 may begin with the introduction of compressed air to the pump through the air intake  134 , as above. The bladder  5  preferably expands both radially and axially upon introduction of air. Axial bladder expansion most preferably causes the lower bladder part  116  to migrate away from the upper bladder attachment to the pump head. Correspondingly, the leader attachment  111  may pull on the spring attachment cable  112 , stretching the opening spring  113  and pulling on the steel leader  114 . The steel leader may pull on the valve rod, which may pull on valve core  101 , forcing the pneumatic pressure relief valve into the fully open position, once the requisite force level is met to overcome the additional friction provided by the mating of circumferential ring  143  and upper groove  141 . Air is then preferably released from the interior of the bladder  5  to the local atmosphere, through the closing rod, the cap manifold  120 , the at least one orifice  104  and hollow center of the valve core  101 . Release of air preferably causes the bladder  5  to return to its initial shape, the bladder  5  preferably being sufficiently elastic so as to have a memory of this initial shape and a mechanical propensity to return thereto. 
     While the description above refers to particular embodiments of the present invention, it will be understood that many modifications may be made without departing from the spirit thereof. The accompanying claims are intended to cover such modifications as would fall within the true scope and spirit of the present invention. 
     The presently disclosed embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims, rather than the foregoing description, and all changes that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.