Patent Abstract:
A sprayer for providing a regulated flow of material to a gun wherein said material is disbursed by means of a flow of air provided by a compressor. The sprayer includes a number of features that facilitate usage. Such features include a polygonal-shaped free end of a cartridge shaft that is aligned with and coupled to thereby rotate with the augur of a pump. An aperture in a guard that overlies the free end of the shaft permits easy access with a socket-like tool for unfreezing the pump without disassembly. The rear panel of a hopper exceeds that of the side and front panels to permit tipping of the sprayer frame for manual transport without spillage of material. A hook is provided on the frame of the sprayer for ready attachment and detachment of controller electronics.

Full Description:
BACKGROUND 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to sprayers for use in the application of textured finishes to surfaces. More particularly, this invention pertains to a convenient and user-friendly sprayer unit for jobs of relatively-limited scope. 
         [0003]    2. Description of the Prior Art 
         [0004]    Texture spray equipment for use in small and medium size jobs that offers quick set-up, easy disassembly, compactness, portability and interchangeability of parts for quick, inexpensive repair has been developed over the years to address the inadequacies of bulky drywall material spraying systems for pumping liquids at job locations. Such bulky systems require mounting onto vehicles or trailers for ease of transportation and are characterized by, for example, large storage tanks that render their usage economical only for large jobs. 
         [0005]    Examples of such spray equipment for smaller jobs include the sprayer taught by U.S. Pat. No. 5,967,426 of McLoed covering “Knockdown portable Liquid Drywall Material Spray System and Apparatus” and others. Such systems are typically mounted on a wheelable cart-like frame and interact with a compressor to provide a controllable spray of material for adhering onto a surface. 
         [0006]      FIG. 1  is a schematic view of a generalized texture deposition system  10  of the type discussed above. The sprayer  11  of the sprayer system is indicated in broken outline. A hopper  12  is arranged to receive input material  14  for eventual deposition onto a surface. The material (e.g. drywall)  14  is transferred, generally by means of gravity feed, into a pump  16  of the screw-feed (rotor and stator) type. The pump  16  advances the received material  14  linearly toward a nozzle  18 , in response to the output of an electric motor  20  whose speed and power are selectively controlled by means of a control box  22 . 
         [0007]    A hose  24  is fitted to the nozzle  18  to receive the material  14  at a predetermined flow rate. The material hose  24  feeds the flowing material to a gun  26 . A second input to the gun  26  comprises an air flow generated by a compressor  28  and delivered through an air hose  30 . The relative flow parameters of material  14  through the material hose  24  and air through the air hose  30  to the gun  26  determine the thickness and texture of the resultant material deposited upon a surface. 
         [0008]    While texture deposition systems as described above may be configured for suitability for small and medium sized jobs, such equipment is often not user friendly. Although relatively portable, operation of such wheeled equipment is complicated by such limitations as spillage of material from the hopper  12  and shorting of the circuitry of the control box  22  as a result of weather. Furthermore, the sprayer  11  often requires disassembly of the pump  16  after period of extended non-use as a result of adhesion of the internal rotor to a surrounding layer of rubber within the stator. 
       SUMMARY OF THE INVENTION 
       [0009]    The present invention addresses the preceding and other shortcomings of the prior art by providing, in a first aspect, a sprayer for providing a regulated flow of material to a gun for subsequent dispersion onto a surface. Such sprayer includes a hopper for receiving the material. 
         [0010]    A pump is provided having an elongated cartridge shaft and an elongated augur aligned with the shaft and arranged to respond to rotation of the shaft. The cartridge shaft has opposed coupled and free ends, the free end being of polygonal shape. The pump is responsive to a motor. A controller unit is provided for controlling the motor. 
         [0011]    The sprayer includes a manually transportable frame. 
         [0012]    In a second aspect, the invention provides a sprayer for providing a regulated flow of material to a gun for subsequent dispersion onto a surface that includes a hopper for receiving the material. Such hopper includes (i) a bottom characterized by a plurality panels oriented to slope downwardly toward an internal aperture, (ii) substantially parallel side panels, a rear panel and a front panel extending upwardly from edges of the bottom to define a predetermined volume, (iii) the height of the rear panel exceeding that of the front panel and (iv) the heights of each of the side panels being equal to that of the rear panel at their junctions with said rear panel and being equal to that of said front panel at their junctions with the front panel. 
         [0013]    The sprayer in accordance with the second aspect of the invention additionally including a pump having an upstanding input port for receiving material from the hopper. Such pump being responsive to a motor. A controller unit for controlling the motor and a manually transportable frame. 
         [0014]    In a third aspect, the invention provides a sprayer for providing a regulated flow of material to a gun for subsequent dispersion onto a surface. Such sprayer includes a hopper for receiving the material, a pump having an upstanding input port for receiving material from the hopper and responsive to a motor. 
         [0015]    A controller unit is provided for controlling the motor. The sprayer includes a manually transportable frame that includes at least one horizontal rear frame member. A generally u-shaped member is fixed to the horizontal rear frame member. The controller has a hook for engaging the u-shaped member. 
         [0016]    The foregoing and other features of the invention will become further apparent from the detailed description below. Such description is accompanied by a set of drawing figures. Numerals of the drawing figures, corresponding to those of the written description, point to the features of the invention with like numerals referring to like features throughout. 
     
     
       BRIEF DESCRIPTION OFT THE DRAWINGS 
         [0017]      FIG. 1  is a schematic view of a sprayer system in accordance with the prior art; 
           [0018]      FIGS. 2(   a ) through  2 ( c ) are a perspective view, a partially exploded side elevation view and an exploded perspective view of the cover assembly, respectively, of a sprayer in accordance with an embodiment of the invention; 
           [0019]      FIGS. 3(   a ) and  3 ( b ) are a side sectional view of the pump and a frontal view of the free end of the cartridge shaft, respectively, of a sprayer in accordance with an embodiment of the invention; 
           [0020]      FIGS. 4(   a ) through  4 ( c ) are perspective views in juxtaposition of the hopper and the transport frame and an enlarged exploded perspective view illustrating the interface of the hopper with a portion of the pump, respectively, of a sprayer in accordance with an embodiment of the invention; and 
           [0021]      FIG. 5  is a perspective view of a removable control box engaged to the frame of a sprayer in accordance with an embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0022]      FIGS. 2(   a ) through  2 ( c ) are a perspective view, a partially exploded side elevation view and an exploded perspective view of the cover assembly, respectively, of a sprayer in accordance with an embodiment of the invention. Such a sprayer includes numerous user-friendly features that facilitate maintenance, portability and usability. As a result, the device of the invention further advances the ability of a user to complete low volume texturizing jobs in an efficient manner and absent the “overkill” of large-scale systems. 
         [0023]    As seen in  FIG. 2(   a ), the sprayer  32  comprises two main functional units, a hopper  34  for receiving material and pump  36  whose operation is powered by an electric motor  38 . (A control box for controlling the operation of the motor  38  cannot be seen in  FIG. 2(   a ) but is described and illustrated below.) The entire sprayer assembly is mounted on a frame  40  that includes a pair of wheels  42  (only one of which is visible in  FIG. 2(   a )) that are aligned and rotatable about a common axis  44 . The tubular frame  40  includes legs  46 ,  48  for stabilizing the sprayer  32  at rest and a handle for facilitating ready transport. As will be seen below, the hopper  34  is designed to facilitate transport of the sprayer  32  despite the presence of material within the hopper  34  while the design of the frame  40  facilitates the cooperative engagement of a removable control box, thereby permitting the sprayer  32  to be left outside during inclement weather that would otherwise subject the control electronics of the sprayer  32  to damage. 
         [0024]    A guard  52  overlies the mechanism whereby the output of the motor  38  drives the pump  36 . Such mechanism will be appreciated by additional reference to  FIGS. 2(   b ), a partially-exploded side elevation view of the sprayer  32 , and  2 ( c ), an exploded perspective view of the guard  52  including associated mechanisms. Referring to  FIGS. 2(   a ) through  2 ( c ) now in combination, the motor  38  is fixed to a bracket mount  54  so that the output drive shaft  56  of the motor is arranged to protrude through a v-shaped opening  58  at the bottom of an inner cover  60  that includes a peripheral edge  61 . A planar outer cover  62  is fixed to the inner cover by means of cap screws  64  whereby opposed planar surfaces of the inner and outer covers  60 ,  62  are maintained in parallel spacing defined by the height of the peripheral edge  61  of the inner cover  60 . 
         [0025]    A mentioned earlier, the drive shaft  56  of the motor  38  is aligned to protrude within the region formed between the inner and outer cover  60  and  62  at the v-shaped opening  58 . A small gear is fixed to the end of the drive shaft  56  to engage a timing belt  68  for driving a large gear wheel  70 . The large gear wheel  70  will be seen below to be fixed to an end of a drive train for driving the pump  36 . 
         [0026]    An annular hub  72  is located at the center of the large gear wheel  70  for coupling to a cartridge shaft (not shown) at the end of the drgive train of the pump. A upper aperture  74  within the rear cover  60  is aligned with both the center of the annular hub  72  and with an aperture  76  within the front cover  62 . As a result, the end of the cartridge shaft is aligned with the aperture  76  when fixed to the annular hub  72 . Accordingly, the end of the cartridge shaft is thereby accessible, through the aperture  76  of the front cover  62 , without disassembly of the guard  52 . 
         [0027]    Reference is now made to  FIGS. 2(   b ) and  3 ( a ), a side sectional view of the pump  36  of a sprayer in accordance with an embodiment of the invention, in combination. As can be seen, the pump  36  includes a pump housing block  78  having an upstanding input port  80  for receiving gravity-fed material from the overlying hopper  34 . A cartridge tube  82  and a stator  84  are treadably engaged to opposed ends of the pump housing block  78 . The pump housing block  78  includes an internal elongated passageway  86  within which is located a pump drive train comprising, in combination, aligned elongated elements including a rotor , a connecting rod  90  and a cartridge shaft  92 . The cartridge shaft  92  comprises and elongated member consisting of three adjoining cylindrical elements of successively reduced diameter (when one proceeds outwardly from the interior of the pump housing block  78 ). It is centered for rotation within the internal elongated passageway  86  of the pump housing block  78  by means of an inner bearing  94  and an outer bearing  96 . 
         [0028]    The connecting rod  90  is joined to the cartridge shaft  92  and to the rotor  88  by means of dowel pins  98 ,  100 . The stator  84 , of conventional design, includes a filled rubber interior  100  within, which the rotor  88  is aligned for rotation along the central axis of the elongated internal passageway  86  of the pump housing block  78 . Accordingly, the axes of rotation of the elongated stator  88 , the connecting rod  90  and the cartridge shaft  92  are aligned within the pump housing block  78 . 
         [0029]    The free end  102  of the cartridge shaft  92  is polygonal, preferably hexagonally shaped as seen in  FIG. 3(   b ), a frontal view of the free end of the cartridge shaft  92 . In the prior art, the rubber of the filled rubber interior  100  of the standard stator  88  is known to adhere to the rotor  88  during periods of non-use. As a consequence, disassembly of the pump  36  has been required to render the sprayer operational. Such disassembly can be tedious and time-consuming. To overcome this difficulty, in the present invention, the free end  102  of the cartridge shaft  92  comprises a polygonal shape that may be engaged by an appropriately-shaped socket wrench. Further, the cylinder shaft  92  is positioned in alignment with the aperture  76  within the outer cover  62  of the guard  52 . As result, the free end  102  may be engaged by such a socket wrench without any disassembly. Once so engaged, the user can free the rotor from adhesion to the filled rubber interior  100  of the stator  84  by applying manual (or mechanical) for to the wrnch to cause the entire aligned, elongated pump drive assembly comprising the cylinder shaft  92 , the connecting rod  90  and the rotor  88  to rotate a sufficient amount to break the adhesion force. 
         [0030]      FIGS. 4(   a ) through  4 ( c ) are perspective views in juxtaposition of the hopper and the transport frame of a sprayer in accordance with an embodiment of the invention. The hopper  34  comprises an integral molded structure of plastic or other synthetic composition that defines a volume within an interior bounded by a front panel  104 , opposed side panels  106  and  108 , and a rear panel  110 . The height of the rear panel  110  exceeds that of the front panel  104 . Accordingly, the edges of side panels  106  and  108  that intersect the rear panel  110  are of greater than those that intersect the front panel  104  as shown. A lid  112  protrudes from the top of the rear panel  110  and adjoins the extended regions of the side panels  106 ,  108  having heights approximately equal to that of the rear panel  110 . 
         [0031]    Viewing the hopper  34  in conjunction with the juxtaposed frame  40 , one can see that the hopper  34  is aligned with respect to the transport frame so that the rear panel  110  lies against upstanding tubular frame members  114 ,  116  that define the back of the frame  40 . Such members  114 ,  116  are positioned to rotate about the axle  44  common to the paired wheels  42 . The permits the user to transport the sprayer by rotating the handle  50  downwardly and pushing the device. The lid  112  that covers the rear portion of the hopper  34  prevents the overflow of material from the hopper  34  during such transport. Thus, unlike other knockdown sprayers, one may relocate the sprayer of the invention without first emptying the hopper of drywall or other material prior to manual transport. This additionally simplifies and facilitates the use of the invention. 
         [0032]    As can be seen in  FIG. 4(   b ), a generally u-shaped flange member  118  is fixed to the handle  50  of the frame  40 . Such member  118  is provided for engaging a mounting bracket  119  fixed to a control box  120  as illustrated in  FIG. 5 . The control box  120  provides the switches for adjusting the direction and speed of the electric motor  38  that, in turn, controls operation of the pump  36 . While of standard design, it is significant that the control box  120  of a sprayer in accordance with an embodiment of the invention is fully removable, allowing its ready removal upon decoupling of associated cabling  122  from other elements of the sprayer. This permits one to then lift the control box  120  from the generally u-shaped flange  118  at the rear of the frame  40  for interior storage while the sturdy remainder of the sprayer is left outside. Again, this feature, a control box  120  removably fixed to the frame of the sprayer, further facilitates the use of the invention. 
         [0033]    Thus it is seen that the present invention provides a user friendly sprayer of the knockdown type. By employing a sprayer in accordance with the claimed invention, the user enjoys numerous user-friendly features. Such features avoid any need to disassemble the sprayer pump after periods of prolonged non-use, permit manual transport of the sprayer while drywall or other material is present in the hopper and allow the device to be left outside during inclement weather. 
         [0034]    While the invention has been described with reference to a presently-preferred embodiment, it is not limited thereto. Rather, the invention is limited only insofar as it is defined by the following set of patent claims and includes within its scope all equivalents thereof.

Technology Classification (CPC): 5