Air compressor workbench

Information

  • Patent Grant
  • 6773237
  • Patent Number
    6,773,237
  • Date Filed
    Monday, August 27, 2001
    23 years ago
  • Date Issued
    Tuesday, August 10, 2004
    20 years ago
Abstract
A workbench for an air compressor that includes a work surface as its top surface. The workbench is provided on wheels, such as caster wheels. The workbench may be closed by panels to attenuate sound. The panels may be removable to provide access to the compressor for maintenance or repair. A mechanism may be provided whereby a drain for the air compressor may be remotely actuated so that the compressor tank may be drained without opening the panels or having to reach under the workbench. The power feed to the motor may be used to power an outlet on the workbench when the motor is not running. The outlet may be provided on the outer shell of the workbench (e.g., on a panel on the outside of the workbench). A switch may be provided that routes the power to the outlet instead of the motor.
Description




FIELD OF THE INVENTION




The present invention relates generally to power tools, and more particularly to compressors.




BACKGROUND OF THE INVENTION




Air compressors are becoming commonplace in home workshops. In general, an air compressor, or an air pump, is a machine that decreases the volume and increases the pressure of a quantity of air by mechanical means. Air thus compressed possesses great potential energy, because when the external pressure is removed, the air expands rapidly. The controlled expansive force of compressed air is used in many ways and provides the motive force for air motors and tools, including pneumatic hammers, air drills, sandblasting machines, and paint sprayers.




A conventional home workshop air compressor includes a storage tank for compressed air, and a prime mover mounted on the storage tank for compressing the air in the tank. The prime mover may be a gas engine or an electric motor, but most conventional home workshop models utilize electric power. The tanks are typically steel and cylindrical in shape, and sizes vary greatly, but typically, home workshop models range between four and thirty gallons. The air compressors typically include a pedestal of some kind (e.g., four feet) that allow the compressors to rest on a surface such as a floor. Alternatively, for some larger models, a pair of wheels may be provided on one end of the tank and a handle on the other end, permitting the air compressor to be wheeled around a work shop, for example.




While conventional air compressors work well for their intended purpose, they often add additional clutter in an already crowded work shop or garage. This problem is particularly true for compressors that have larger tanks, which handymen often select because of their larger air reserve capacity.




The size and configuration of conventional home workshop air compressors can also make their storage difficult. For most designs, the tanks are rounded, and the handle, pump, and the motor protrude above the tank. This configuration makes stacking or storing items on the tank difficult or impossible.




Another problem with air compressors is aesthetics. For most conventional air compressor designs, the motor, the tank, the wheels, and the handle are exposed, causing the compressor to have an industrial appearance. Although the compressor is often stored and used in a workshop environment, the various components that are visible on a compressor may make the workshop appear crowded or unkempt.




Home workshop air compressors can also be loud, especially in a closed environment. The compressor must run to generate and maintain pressure in the tank, and its operation can be a loud distraction.




SUMMARY OF THE INVENTION




The present invention solves many problems of the prior art by providing an air compressor that is mounted in a workbench. The workbench includes a work surface at its top, on which work may be performed, or items may be stored.




In accordance with one aspect of the invention, the workbench may be provided on wheels, such as caster wheels. This feature permits the compressor and workbench to be wheeled to a convenient location. The workbench may have open sides, so that the compressor is exposed, or may have panels so that the compressor is hidden from view. If panels are used, the workbench may have an attractive appearance, and thereby may easily be integrated into a workshop or other environment. In addition, the panels may be used to attenuate noise from the compressor motor. The panels may be removable to provide access to the compressor for maintenance or repair.




If panels are used on the outside of the workbench, in accordance with another aspect of the invention, a mechanism may be provided whereby a drain for the air compressor may be remotely actuated. For example, a handle may be provided on the outside of a panel on the workbench that is connected to the drain plug by a linkage. As another example, a foot pedal may be provided that is connected to the drain plug. The remote actuation of the compressor provides a mechanism by which the compressor tank may be drained without opening the panels or having to reach under the workbench.




The air compressor mounted within the workbench may utilize direct drive, belt drive, or other suitable drive systems. The prime mover for the air compressor is preferably electric. If the motor utilizes an electrical system, the power feed to the motor may be used to power an outlet on the workbench. The outlet may be provided on the outer shell of the workbench (e.g., on a panel on the outside of the workbench). A switch may be provided that routes the power to the outlet instead of the motor, or the outlet may be alive at all times.











Other advantages will become apparent from the following detailed description when taken in conjunction with the drawings, in which:




BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is an isometric view of a compressor workbench in accordance with one aspect of the present invention;





FIG. 2

is a front, view of a the compressor workbench of

FIG. 1

, with panels removed, exposing a compressor mounted in the workbench;





FIG. 3

is an isometric view of the compressor workbench of

FIG. 1

, showing side and rear panels and a work surface removed;





FIG. 4

is a left side view of the compressor workbench of

FIG. 1

;





FIG. 5

is a top, side perspective view of a tool tray for the compressor workbench of

FIG. 1

;





FIG. 6

is a bottom, side perspective view of the tool tray of

FIG. 5

;





FIG. 7

is a partial-cutaway, side view of the a bottom portion of the compressor workbench of

FIG. 1

showing a drain valve actuation mechanism;





FIG. 8

is a partial-cutaway, side view of the a bottom portion of the compressor workbench of

FIG. 1

, similar to

FIG. 7

, with the drain valve actuation mechanism actuated;





FIG. 9

is a cutaway detail view of the handle for the drain valve actuation mechanism, shown in a normal, closed position;





FIG. 10

is a cutaway detail view of the handle of

FIG. 9

, shown in an opened position;





FIG. 11

is a simple schematic for a compressor and outlet combination that may be used with the workbench of

FIG. 1

;





FIG. 12

is a simple schematic for an alternate embodiment of a compressor and outlet combination that may be used with the workbench of

FIG. 1

, with a switch turned to an “outlet on” position, and





FIG. 13

is the simple schematic of

FIG. 12

, with the switch turned to a “compressor pump on” position.











DETAILED DESCRIPTION




In the following description, various aspects of the present invention will be described. For purposes of explanation, specific configurations and details are set forth in order to provide a thorough understanding of the present invention. However, it will also be apparent to one skilled in the art that the present invention may be practiced without the specific details. Furthermore, well-known features may be omitted or simplified in order not to obscure the present invention.




Briefly described, with reference to

FIG. 1

, the present invention provides a workbench


20


for an air compressor


22


(the air compressor is hidden in

FIG. 1

, but shown in FIG.


2


). A work surface


24


is mounted on the top of the workbench


20


, and the workbench includes wheels


26


so that the workbench may be easily moved.




As can be seen in

FIG. 2

, the workbench includes a frame


28


made, for example, of tubular steel or aluminum. The frame


28


includes left and right U-shaped frame ends


30


,


32


(detail of the left U-shaped frame end


30


is shown in FIG.


3


), the top edges of which extend to the work surface


24


. The lower parts of the left and right U-shaped frame ends


30


,


32


are attached to a wheel support


34


. The wheel support


34


may simply be a plate or a bracket that extends between the lower parts of the left and right U-shaped frame ends


30


,


32


, or may be a pan that extends around the bottom of the compressor


22


.




Front and rear bottom frame members


36


,


38


(

FIGS. 2 and 3

, respectively) extend along, and are attached, for example, by welding or screws, to the left and right U-shaped frame ends


30


,


32


. The front and rear bottom frame members


36


,


38


provide structural reinforcement for the bottom of the frame


28


.




The wheels


26


may be plastic, solid or inflatable rubber, or any other suitable material, and are attached to the bottom pan


34


by brackets


40


,


42


. As can be seen in

FIG. 4

, the brackets


40


on one end may swivel, and the brackets


42


on the other end may be fixed, so that the workbench


20


may be easily directed to a desired location. If desired, however, all four brackets


40


,


42


may swivel for increased maneuverability of the workbench


20


. In addition, if desired, one or more of the wheels may be lockable so as to secure the workbench


20


in position. Other suitable caster wheels may be used for the workbench


20


, and may be attached as appropriate.




Front and rear top frame members


44


,


45


(

FIG. 3

) extend between the top ends of the left and right U-shaped frame ends


30


,


32


. The front and rear top frame members


44


,


45


extend against the work surface


24


and add further structural reinforcement to the frame


28


. Side braces


46


,


48


extend between upper ends of the left and right U-shaped frame ends


30


,


32


, and add further support for the frame


28


.




The frame


28


includes a drawer housing


50


. The drawer housing


50


includes front and rear L-shaped supports


52


,


54


, a side panel


56


, and a bottom panel


58


. The front and rear L-shaped supports


52


,


54


, along with the front and rear top frame members


44


,


45


and the left and right U-shaped frame ends


30


,


32


, form a reinforced box for the front and rear ends of the drawer housing


50


. As can be understood, the drawer housing


50


may be constructed differently. For example, a single piece of metal may be bent around the bottom and two sides, and/or the top of the housing. However, however constructed, preferably the panels of the drawer housing


50


(e.g., the side panel


56


and the bottom panel


58


) separate the inside of the drawer housing


50


from the compressor, providing safety and cleanliness. A drawer


62


(

FIG. 1

) is mounted in the drawer housing


50


, for example on drawer slides (not shown).




The work surface


24


is large, sturdy, and rectangular, and is made, for example, of MDF, wood, metal, or another suitable material. A pair of bars


72


,


74


extend down opposite sides of the work surface


24


. The outer faces of the bars


72


,


74


include T-slots


76


(only the T-slot for the front bar


72


is shown, but the rear bar


74


may include a similar T-slot). The T-slots


76


are configured to receive attachments, such as nuts. The attachments may be used to hang accessories or other items along the edges of the work surface


24


. The T-slots


76


shown in the drawing are located on the outer edges of the bars


72


,


74


, but similar T-slots may be provided on other locations on the workbench, such as on the top and bottoms of the bars.




A pair of handles


80


,


82


are mounted at opposite ends of the work surface


24


, and extend between the bars


72


,


74


. The handles


80


,


82


may be formed of wood, steel, plastic, or another suitable material, and may be used to push the workbench


20


, or for lifting the ends of the workbench, if necessary.




In accordance with one aspect of the present invention, the work surface


24


includes a cup and tool holder


84


, the details of which are shown in

FIGS. 5 and 6

. A top side of the cup and tool holder


84


includes holes


86


at one end for upright storage of tools, e.g., air tools. An open storage bin


87


for miscellaneous tools and objects is located along the middle of the cup and tool holder


84


, and a cup holder


88


is located on the end opposite the holes


86


. The bottom of the cup and tool holder


84


includes ribs


89


(

FIG. 6

) for reinforcement. Ends


85


of the cup and tool holder


84


are flattened, and configured to fit against the bars


72


,


74


, so that the cup and tool holder is captively fit adjacent the work surface


24


. The cup and tool holder


84


may be formed of plastic or any other suitable material.




As can best be seen in

FIG. 3

, the workbench


20


includes a front panel


90


, left and right panels


92


,


94


, and a rear panel


96


. In one embodiment, the front panel


90


is fixed to the frame


28


, and the left and right panels


92


,


94


, and the rear panel


96


are removable. To aid in easy removal, left and right panels


92


,


94


include a lower 90-degree lip


98


, side edges


100


,


102


, and a top 90-degree lip


104


.




To place the left panel


92


onto the frame


28


, the lower 90-degree lip


98


and a top 90-degree lip


104


are aligned slightly over the bottom of the left U-shaped frame end


30


and the side brace


46


, respectively, with the side edges


100


,


102


aligned just inside the left U-shaped frame end. The left panel


92


is then lowered so that the lower 90-degree lip


98


and a top 90-degree lip


104


rest on the bottom of the left U-shaped frame end


30


and on the side brace


46


, respectively. The side edges are sandwiched between, and held steady by, the outer legs of the left U-shaped frame end


30


. The right panel


94


may similarly be placed on the opposite side of the frame


28


. A handle


104


is provided at the bottom of each of the left and right panels


92


,


94


to aid in removal and replacement. One or more screws or other fasteners may be used to lock a panel once it is in position.




The left and right panels


92


,


94


include a series of vent holes


106


distributed along their surfaces. The vent holes


106


provide circulation for the compressor


22


, and apertures into which hooks for accessories or other items may be hung.




Other structures may be provided for attaching to the ends of the frame


28


. For example, one or two tool boxes may be provided that are configured to be attached to the ends of the frame


28


.




The left and right panels


92


,


94


may be attached in different ways, but preferably at least one of the outer panels of the workbench is easily removable to provide access to the compressor


22


. The structure for left and right panels


92


,


94


described above is removable without tools, and if a single fastener is used, is quickly removable by releasing the single fastener with a single tool. The rear panel


96


may include similar structure for easy removal, or may include screws or other fasteners that permit removal. By allowing easy removal of the panels


92


,


94


, and


96


, the compressor


22


may be accessed for repair or maintenance.




The panels


90


,


92


,


94


, and


96


form an enclosure around the compressor


22


, and help to attenuate the noise made by the air compressor


22


. The panels


90


,


92


,


94


, and


96


may be made of any suitable material, such as steel, and may be insulated for sound. In addition, other internal panels may be provided that extend downward from the work surface


24


and surround the prime mover for the compressor


22


for further sound attenuation. If desired, the outer surfaces of the panels


90


,


92


,


94


, and


96


may be painted or otherwise decorated to alter the appearance of the workbench


20


.




The air compressor


22


may be a direct drive, belt driven, or may utilize another suitable driving mechanism. Air compressors and their function are well known, and their operation is not discussed in detail here. The air compressor is preferably mounted within the workbench, and, if the panels are used, is surrounded by the panels. In this manner, the compressor


22


is fully supported by the workbench


20


, and moves with the workbench when the workbench is rolled around on the wheels


26


. In addition, the panels may attenuate some of the sound of the compressor.




A prime mover


108


for the compressor


22


preferably includes an electric motor and a pump, but alternatively may utilize a gasoline engine and a pump. A power cord


109


is provided for connecting the prime mover


108


to a power source. A cord wrap


110


(

FIG. 4

) may be provided, for example on the back of the rear panel


96


, for storage of the power cord


109


. If desired, a hose hook (not shown) or the like may be provided for storing one or more air hoses.




The air compressor


22


includes a tank


112


, for example a twenty gallon cylindrical tank. The tank


112


includes a drain valve


114


(

FIG. 7

) on its lower surface for draining water that is generated during compression of air. A metal guard cage


116


(shown in phantom so that other details are visible) extends around the drain valve


114


to prevent the drain valve from being damaged during moving of the workbench


20


.




The workbench


20


includes a drain valve actuation mechanism


118


that permits the drain valve


114


to be opened without having to reach under the workbench. The drain valve actuation mechanism


118


includes an L-shaped pivot arm


120


that is pivotally attached at one end to a surface on the bottom of the workbench


20


, for example to the lower wall of the tank


112


. A plunger


122


of the drain valve


114


extends through a hole or slot in the L-shaped pivot arm


120


and includes an “E” retaining ring


124


(best shown in

FIG. 8

) at its distal end. The “E” retaining ring


124


is sized so that it does not fit through the hole or slot in the L-shaped pivot arm


120


. The plunger


122


is spring-biased to a closed position such that the internal pressure of the tank will not open the valve during operation of the compressor


22


.




A linkage


128


is connected to the free end of the L-shaped pivot arm


120


by a push retainer


130


, which connects up and down movement of the linkage to movement of the L-shaped pivot arm


120


. The opposite end of the linkage includes a 90-degree bend


131


that extends through a C-slot


132


in the front panel


90


. A knob


134


is attached to the distal end of the linkage


128


.




During operation of the compressor


22


, the knob


134


is typically maintained in an upper position, such as is shown in FIG.


9


. In the upper position, the linkage


128


is prevented from moving downward by the 90-degree bend


131


of the linkage being caught in a downwardly-sloping portion


136


(shown best in

FIG. 10

) at the upper end of the C-slot


132


. In this position, the drain valve


114


is closed.




To operate the drain valve actuation mechanism


118


to open the drain valve


112


, the knob


134


is grasped by a user, and rotated around the C-slot to the lower position shown in FIG.


9


. This movement causes the linkage to move down, shown by the arrow


137


in

FIG. 8

, which in turn causes the L-shaped pivot arm


120


to pivot downward (arrow


138


), pulling the plunger


122


downward (arrow


139


), and opening the drain valve


112


.




Using the drain valve actuation mechanism


118


permits a user to drain water from the tank


112


without having to reach under the workbench


20


. Other mechanisms may be used to actuate the drain valve remotely. For example, a drain valve actuation mechanism may be foot operated, may use one or more solenoids connected to a switch, or may have other means for remotely opening a drain valve that is connected to the air compressor tank.




In accordance with another aspect of the present invention, a control panel


140


(

FIG. 1

) is mounted on the front side of the workbench


20


on the outside of the enclosure formed by the panels


90


,


92


,


94


, and


96


. The control panel


140


includes a quick disconnect


142


to which an air hose may be attached, a safety relief valve


144


for the tank


112


, and a regulator knob


146


for setting the outlet flow of an air hose attached to the quick disconnect


142


. A pressure gauge


148


for the tank is supplied, as well as a pressure gauge


150


for the hose connected to the quick disconnect


142


. An on/off switch


162


is provided on the front of the control panel


140


. The function and operation of each of these items is known in the art of air compressors, and thus will not be discussed in detail here. Other controls and gauges may be provided. For example, a second quick disconnect, regulator, and gauge may be provided for a compressor that can handle multiple outputs.




The workbench


20


of the present invention may be sized as convenient, but preferably is of sufficient size so that the compressor can be fully enclosed by the panels


90


,


92


,


94


, and


96


. In one embodiment of the present invention, the workbench


20


is 39 inches high, 36 inches wide, and 19 inches deep. This size allows the workbench


20


to be reasonably stored, and provides a work surface


24


that is sized so that it may be used for several different home improvement projects.




In accordance with one aspect of the present invention, the workbench may include a power supply, such as an outlet


160


(FIG.


1


). A simplified circuit for the outlet


160


is shown in FIG.


11


. The outlet


160


is connected to a power supply, with a circuit breaker


158


(e.g., a 15 amp circuit breaker) between the power supply and the outlet.




The prime mover


108


is wired in series with the outlet


150


, and power to the prime mover is determined by the switch


162


and the pressure switch


164


. The pressure switch


164


is connected to the tank


112


, and is in a normally opened position, and closes when the tank exceeds a lower pressure threshold. The pressure switch remains closed as long as the pressure is above the lower pressure threshold, and the tank does not exceed an upper pressure threshold. In general, for the prime mover


108


to operate, the switch


162


must be turned to an “on” position, and the pressure switch must be in the closed position. When the pressure in the tank


112


exceeds the upper threshold, the pressure switch


164


is opened, and the power to the prime mover is cut.




In the system shown in

FIG. 11

, the outlet


160


has power whether the prime mover


108


is operating or not. If desired, the power circuit for the outlet


160


and the prime mover


108


may include a switching system that permits a user to remove power from the prime mover


108


, so that all power is directed to the outlet


160


. Such a system is shown in

FIGS. 12 and 13

. In the system of these figures, a switch


200


, for example, a heavy duty switch or relay mounted on the front panel, may be set at “ELECTRICITY” or “AIR.” When the switch is set to the “ELECTRICITY” position, power is cut to the pump motor (prime mover)


108


, and all current is directed towards the outlet


160


at the rated amperage of the circuit (e.g., 15 amps). When the switch


200


is set to “AIR,” the power is cut to the outlet


160


, and the routed to the pump motor (prime mover)


108


. The pump motor


108


then activates as needed to maintain pressure in the tank


112


in a manner known in the art.




As is known, when a pump for a compressor is running, air is pressurized in the pump head, and as it reaches an appropriate pressure, enters the compressor tank through a one-way check valve. In normal air compressors, a pressure switch


202


bleeds the air trapped between the pump and the check valve when there is a signal from the tank (e.g., upper pressure limit) to deactivate the motor. The pressurized air is thus removed from the pump head, so that the pump is ready for use again when the pressure in the tank falls below the minimum threshold.




When the pump is turned off by the switch


200


, however, there may be pressurized air trapped in the pump's head. A user may, for example, switch power away from the pump during an activated cycle, and switch back later. If the pressure is too great within the pump's head, the motor may not be able to start operation of the pump against the pressure.




To alleviate this problem, in accordance with one aspect of the present invention, an air solenoid


204


is provided in the circuit with the switch


200


and the pressure switch


202


. The air solenoid


204


is connected to the check valve


206


for the air tank


112


, and is in a normally open position (FIG.


12


), wherein pressure for the pump head is allowed to vent (via the check valve through the opened air solenoid


204


). The air solenoid


204


, wired with the pressure switch


202


, will close when the switch


200


is placed in the “AIR” position, allowing the pressure switch to bleed as needed (i.e., such as in normal air compressor operation). The air solenoid


204


is in the normal, opened position when the switch


200


is in the “ELECTRICAL” position. Thus, when the electrical outlet


160


is activated, the pressure in the pump head is released, allowing the pressure switch


200


to bleed the pump head pressure through a the air solenoid


204


.




Other variations are within the spirit of the present invention. Thus, while the invention is susceptible to various modifications and alternative constructions, a certain illustrated embodiment thereof is shown in the drawings and has been described above in detail. It should be understood, however, that there is no intention to limit the invention to the specific form or forms disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention, as defined in the appended claims.



Claims
  • 1. An apparatus comprising:a frame; an air compressor mounted in the frame, the air compressor comprising an air tank; an enclosure surrounding the air tank; a drain valve on the tank; a manual drain actuation mechanism mounted outside of the enclosure; and a linkage connecting the drain actuation mechanism to the drain valve, wherein manual actuation of the drain actuation mechanism causes the drain valve to open, permitting the tank to drain.
  • 2. The apparatus of claim 1, further comprising wheels on the apparatus, the wheels being positioned so that the apparatus can be rolled.
  • 3. The apparatus of claim 1, wherein the enclosure comprises multiple panels, and wherein at least one of the panels fits into a slot on the frame, wherein the panel may be easily removed or replaced.
  • 4. The apparatus of claim 1, wherein the enclosure comprises multiple panels, and wherein at least one of the panels is removable with the removal of a single fastener.
  • 5. The apparatus of claim 1, wherein the enclosure comprises multiple panels, and wherein at least one of the panels is removable.
  • 6. The apparatus of claim 1, wherein the drain actuation mechanism comprises a handle.
  • 7. The apparatus of claim 1, further comprising:a power cord connected to the motor by an electric circuit; and an electrical outlet wired to the circuit in series with the motor.
  • 8. The apparatus of claim 7, further comprising a switch for selectively switching power supplied via the power cord between the motor and the outlet.
  • 9. The apparatus of claim 8, further comprising a bleed valve for bleeding the pressure within the pump when the switch switches power to the outlet, and a mechanism, connected to the circuit, that opens the bleed valve when the switch switches power to the outlet.
  • 10. The apparatus of claim 9, wherein the mechanism is a solenoid.
  • 11. The apparatus of claim 7, wherein the outlet is mounted on the enclosure.
  • 12. The apparatus of claim 7, further comprising sound-detonating panels mounted around the motor.
  • 13. The apparatus of claim 1, further comprising sound-detonating panels mounted around the motor.
  • 14. The apparatus of claim 1, wherein the enclosure comprises front, rear, left and right side panels, and wherein the side panels are removable.
  • 15. An Apparatus comprising:an electric motor connected to a compressor a power cord connected to the electric motor by an electric circuit; an electrical outlet wired to the circuit in series with the motor; and a switch for selectively switching power supplied via the power cord between the motor and the outlet, the switch being operable between a first position where power is directed to the outlet and is cut from the electrical motor, and a second position where power is directed to the electrical motor and cut from the outlet.
  • 16. The apparatus of claim 15, wherein the compressor is an air compressor comprising a pump, and further comprising a bleed valve for bleeding the pressure within the pump when the switch switches power to the outlet, and a mechanism, connected to the circuit, that opens the bleed valve when the switch switches power to the outlet.
  • 17. The apparatus of claim 16, wherein the mechanism is a solenoid.
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