Vacuum system

A vacuum system has a cabinet that can be mounted to a wall. The cabinet includes a hose storage compartment with a hose drive assembly for automatically extending and retracting a vacuum hose. A portable vacuum unit can be removably docked to the cabinet and connected to the vacuum hose so that waste can be picked up the vacuum hose when the portable vacuum unit is docked. When undocked, the portable vacuum unit can be used alone.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates generally to vacuum systems, and more particularly to a wall mounted vacuum system with a portable vacuum unit.

2. Description of the Related Art

While not as popular as portable vacuums, central vacuum systems are found in many residential homes. Central vacuums have a fixed location vacuum unit, which many users find convenient since they do not have to pull the vacuum unit throughout the house. There are two common hose systems for central vacuums. One of which is the movable hose, where a detachable hose can be moved from one vacuum port to another. The vacuum ports are located at strategic locations in the house. In a movable hose system, the user only has to carry the hose from room to room.

The other common hose system is a retractable hose that is stored within a housing at a central location in the house. The hose housing can be located within a wall or appear as a cabinet in the wall. The retractable house is more convenient regarding the storing of the hose.

Most users of central vacuum systems prefer them over portable vacuums in that they are less burdensome to use in that the vacuum unit need not be carried or pulled around the house. However, a lot of owners of central vacuum systems also own a portable vacuum in that there is inevitably some place in the home where the central vacuum cannot reach or they desire to vacuum outside the home, say a car or garage, where the central vacuum was not designed to reach.

In the case of vacuuming areas such as a garage or shop, most users have yet another type of vacuum, which is design to vacuum larger particles, such as wood chips, and even water, unlike the standard household vacuum. These types of vacuums are generally referred to as shop vacs. They tend to have a more robust motor, stronger vacuum, and a filter system that permits the vacuuming of water.

There is a need to provide the benefits of both a central vacuum system and a portable vacuum cleaner. Moreover, there is a need to do so while providing the benefits of a shop vacuum.

SUMMARY OF THE INVENTION

This need is met in the present invention of a vacuum system comprising a cabinet adapted to be mounted to a wall, a hose extendable from the cabinet between a retracted position and an extended position and having a proximal end fixed within the cabinet, and a portable vacuum unit detachably mountable to the cabinet. The portable vacuum unit has a tank, an inlet port in fluid communication with the tank, and a vacuum source to draw air from the inlet port into the tank. The proximal end of the hose is connectable with the inlet port when the portable vacuum unit is docked to the cabinet, so that the hose can be used to vacuum waste into the tank when the portable vacuum unit is docked to the cabinet with the proximal end connected to the inlet port. But also, the portable vacuum unit can be used to vacuum waste into the tank when the portable vacuum unit is detached from the cabinet.

The cabinet can include a hose storage compartment where the hose is stored when the hose is in the retracted position. The system can also have a retraction stop mechanism to limit retraction of the hose. Preferably, the reaction stop mechanism includes a sleeve mounted to the hose and a limit switch mounted to the cabinet so that the sleeve will activate the limit switch to halt retraction of the hose. Similarly, the system can also have an extension stop mechanism to limit extension of the hose. Preferably, the extension stop mechanism includes a projection on the hose and a limit switch mounted to the cabinet so that the projection will activate the limit switch to halt extension of the hose.

A handle can be mounted to the hose, preferably retained out of the cabinet when the hose is in the retracted position. The handle can have an LED. Preferably, the handle has a nozzle portion and a grip portion, with the nozzle portion being angled relative to the grip portion. Also, preferably, the handle nests within a collar on a top wall of the cabinet. Ideally, the handle is canted relative to the cabinet for ease of access.

In another aspect of the invention, a portable vacuum hose is mounted to the portable vacuum unit for use when vacuuming with the portable vacuum unit. Preferably, the portable vacuum unit has an outlet port. If so, the outlet port can be configured to receive a blower hose to direct air from the outlet port as a blower.

In a further aspect, the proximal end of the hose and the inlet port are automatically connected when the portable vacuum unit is docked to the cabinet. Similarly, the cabinet has a power outlet and the portable vacuum unit receives power from the power outlet when it is docked with the cabinet. Preferably, the portable vacuum unit will have a power switch operable to actuate the vacuum source when the portable vacuum unit is detached from the cabinet. If so, then it can also have a bypass mechanism to bypass the power switch when the portable vacuum unit is docked with the cabinet. In yet a further aspect, the vacuum source and the power outlet are automatically connected when the portable vacuum unit is docked with the cabinet.

In another aspect of the invention, the vacuum system can include a hose drive assembly wherein the hose can be selectively driven automatically between the retracted and extended positions. Preferably, the hose drive assembly includes a reversible drive motor, and further preferably, the reversible drive motor is operable in response to actuation of switches on the hose.

In this configuration, the hose may have a handle and the switches can be in the handle. The switches can actuate the reversible drive motor by wireless signals. If so, the hose can have a transmitter and the cabinet can have a controller with a receiver. The controller is electrically connected to the reversible drive motor so that signals from the switches are transmitted to the receiver for actuation of the reversible drive motor by way of the controller.

With a hose drive assembly, the vacuum system can include a retraction stop mechanism to limit retraction of the hose, and/or an extension stop mechanism to limit extension of the hose. Also, the vacuum system can have a clutch mechanism to disengage the hose from the hose drive assembly.

DETAILED DESCRIPTION

The invention is embodied in a vacuum system10illustrated generally inFIGS. 1-3. The vacuum system10comprises a cabinet12adapted to be mounted on a wall. Here, the cabinet12is mounted on a slot wall construction of the type sold by Whirlpool Corporation under the Gladiator® trademark and disclosed in U.S. Pat. No. 6,811,043. The cabinet12comprises an upper portion14and a lower portion16, both bounded by a rear wall18and opposed sidewalls20,22. The upper portion14houses a hose storage compartment24covered by a removable panel26which can provide access to the compartment.

Inside the storage compartment24is a considerable length of vacuum hose28, preferably on the order of 40 feet in length. The vacuum hose28is typically corrugated or formed with a spiral rib, and may be extendable and compressible. The upper end of the vacuum hose28extends through a hose drive assembly30to a handle32. The handle32nests within a collar34around an opening35in an upper wall36of the cabinet12with the vacuum hose28and/or handle32extending through the opening35. The handle32is preferably canted relative to the cabinet when stored as shown. The lower end of the vacuum hose28fluidly communicates with a conduit38that projects into the lower portion16through a wall40that separates the lower portion16from the upper portion14. A female coupler39can be provided on the end of the conduit38.

The lower portion16has a door42that provides access to a lower compartment44. The lower compartment44is also open at a lower end of the cabinet12. A portable vacuum unit46is removably mountable to the cabinet12within the lower compartment44. In this embodiment, a ledge48is mounted to each sidewall20,22within the lower compartment44. The portable vacuum unit46rests on the ledges48so that a portion of it is housed within the lower compartment, accessible by way of the door42, and another portion of it extends through the open lower end of the cabinet12. The cabinet12could just as easily be sized such that the portable vacuum unit is completely received within the interior of the cabinet.

The lower compartment44also houses one or more enclosures50,52for supporting electrical circuitry and controllers that operate the hose drive assembly30and the portable vacuum unit46when it is mounted within the cabinet12. In addition, the lower compartment44can also house additional vacuum attachments such as extension54.

Preferably, the cabinet12will be mounted to a wall in a position so that the portable vacuum unit46will be more than 1½ to 2 feet off the floor. This is especially important in a garage where flammable vapors may accumulate closer to the floor. On the other hand, the cabinet12should not be mounted so high that the handle32is difficult to access. In this respect, it is within the scope of the invention for the handle32and the vacuum hose28to extend from the cabinet12at some point other than the top of the cabinet.

Turning now toFIGS. 4-7, the portable vacuum unit46is more clearly illustrated. The portable vacuum unit46comprises a platform56that supports a motor housing58above it and suspends a tank60beneath it. The tank60is removably mounted to the platform56by clips62or other conventional fasteners. The tank60will also preferably have feet64that will enable the portable vacuum unit46to rest stably on a horizontal surface. Preferably, the portable vacuum unit46will have some means to enable it to be hung separately on a wall47as shown inFIG. 5. Such means can include hooks or mating fasteners such utilized with the Gladiator® system, or something as simple as one or more receptacles to be received on corresponding wall-mounted hooks.

It will be appreciated that the portable vacuum unit46can function as a wet/dry vacuum, and therefore the tank60will have a drain66disposed at a lower portion thereof. The drain66will be sealed by a removable cap68.

Referring primarily toFIGS. 6 and 7, the platform56has a centrally disposed outlet opening70and, to one side thereof, an upwardly extending cone72. The upper end of the cone72defines an inlet opening74. An impeller housing76is disposed over the outlet opening70and defines an exhaust channel78to an outlet opening80opposite the inlet opening74. A vacuum motor82is positioned to drive an impeller within the impeller housing76in conventional manner. The motor housing58houses the inlet opening74, the outlet opening80, the impeller housing76, and the vacuum motor82.

A handle84extends upwardly from the motor housing58, and may be formed of two clamshell halves86,88, and a bridge90. One side of the handle84defines a vacuum port92and the other side of the handle defines a blower port94. A vacuum conduit96extends from the vacuum port92to the inlet opening74, and an exhaust conduit98extends from the outlet opening80to the blower port94. A male adapter100extends out of the vacuum port92in fluid communication with the vacuum conduit96. A power switch102is mounted in the handle84and is electrically connected to the vacuum motor82. A conventional electrical cord104with plug105is also wired in conventional manner to the switch102and to the vacuum motor82to deliver power.

A cylindrical filter106depends from the platform56coaxially around the central outlet opening70. Preferably, a longitudinally slotted support cup108is secured to the platform56around the central outlet opening70. A leg assembly110comprising a central securing plate112and four radially extending legs114is secured to the support cup108by a threaded bolt116. The cylindrical filter106is securely retained between securing plate112and the bottom of the platform56. It will be appreciated that the leg assembly110enables the platform56, motor housing58, handle84, and all the components enclosed therein to stand upright on the leg assembly when the tank60is removed from the platform56.

The motor housing58can further be adapted with various slots and cradles to support assorted tools and attachments117customarily used in vacuuming operations. For example, a separate onboard hose extension118rests in a cradle120around the handle84. It is also within the scope of the invention for the portable vacuum unit46to be cordless, i.e., having an onboard rechargeable battery that can, for example, the automatically recharged when the portable vacuum unit is docked in the cabinet12.

Turning now toFIGS. 8-10, the hose drive assembly30is illustrated in greater detail. The hose drive assembly30comprises a gearbox122, preferably formed of two clamshell halves123,125that define an upper wall124and the lower wall126. An aperture128in the upper wall124is located in registry with an aperture130in the lower wall126. The diameters of the apertures128,130are such that the vacuum hose28can extend through the gearbox122and move freely through the apertures in both directions. The gearbox122houses a reversible drive motor132having a shaft and a worm (not shown inFIG. 8-10). A drive spur gear134mounted to a shaft136engages the worm to rotate when the reversible drive motor132is actuated. A first roller spur gear138is mounted to a shaft140and engages the drive spur gear134. A first roller142is disposed to move with the first roller spur gear138, preferably by either mounting to the first roller spur gear138or mounting to the shaft140. A second roller spur gear144is mounted to a shaft146and engages the first roller spur gear138. A second roller148is disposed to move with the second roller spur gear144, preferably by either mounting to the second roller spur gear144or mounting to the shaft146. The first and second rollers142,148have recessed sheaves150that define a gap152between the rollers. The vacuum hose28extends between the apertures128,130through the gap152so that the corrugations or ribs on the hose engage the sheaves150of the first and second rollers142,148.

It will be apparent that when the reversible drive motor132is actuated in an extending direction, the worm causes the drive spur gear134to rotate in the direction shown by the arrow A inFIG. 8. Similarly, rotation of the drive spur gear134causes the first roller spur gear138and the first roller142to rotate in the opposite direction shown by the arrow B inFIG. 8. In addition, rotation of the first roller spur gear148causes the second spur gear144and the second roller148to rotate in the same direction as the drive spur gear134, shown by the arrow A. As the two rollers142,148rotate in the indicated directions, the sheaves150bear against the corrugations or ribs to urge the vacuum hose28through the gap152, through the opening35in the cabinet12, and out of the hose storage compartment24. Conversely, if the reversible drive motor132were to be actuated in a retracting direction opposite the extending direction, the two rollers142,148will be urged to rotate in opposite directions from that indicated inFIG. 8, thereby urging the vacuum hose28into the storage compartment24.

The hose drive assembly30further comprises a retraction stop mechanism154to stop the reversible drive motor132when the vacuum hose28reaches a predetermined retraction limit, preferably with the vacuum hose completely within the storage compartment24, and the handle32nested within the collar34. It also comprises an extension stop mechanism156to stop the reversible drive motor132when the vacuum hose28reaches a predetermined extension limit.

Exemplary embodiments of a retraction stop mechanism154and an extension stop mechanism156are illustrated inFIGS. 9 and 10. Looking atFIG. 9, a first embodiment of an retraction stop mechanism154includes a hose conduit158extending upwardly from the upper aperture in the gearbox122, and terminates in an annular slot160at or beneath the collar34. A limit switch162, preferably in the form of a microswitch, is mounted within the storage compartment24adjacent the annular slot160. A trigger164is mounted within the annular slot160and movable between a first position where it engages the limit switch162and a second position where it does not engage the limit switch. The trigger164is preferably biased to the second position. The upper end of the vacuum hose28near the handle32carries an annular sleeve166sized to be received within the annular slot160. When the annular sleeve166is nested within the annular slot160, it urges the trigger164to the first position where it engages the limit switch162. The limit switch162is electrically connected to the reversible drive motor132, preferably by way of a printed circuit board (PCB) that controls the drive motor operation in a manner that when the limit switch is engaged by the trigger164being in the first position, the reversible drive motor132is deactivated. In operation, as the vacuum hose28approaches its limit of retraction, the annular sleeve166is received within the annular slot160where it contacts the trigger164, urging the trigger to the first position where it engages the limit switch162to deactivate the reversible drive motor132.

Looking now atFIG. 10, a second embodiment of a retraction stop mechanism154′ includes a hose conduit158extending upwardly from the upper aperture128in the gearbox122. The hose conduit158terminates in an annular cup170. A limit switch172, preferably in a form of a microswitch, is mounted within the annular cup170. A compression spring174extends upwardly from the bottom of the annular cup170and surrounds but does not engage the vacuum hose28. A sleeve176is secured to the upper end of the compression spring174, and has an open socket178at an upper end thereof. A nub180depends from the sleeve176outside the compression spring174in line to engage the limit switch172when the compression spring174is compressed, but not engage the limit switch172when the compression spring174is uncompressed. The open socket178is sized to contact the lower end of the handle32, yet to allow the vacuum hose28to move freely through it. In operation, as the vacuum hose28approaches its retraction limit, the lower end of the handle32contacts the open socket178, and bears against the sleeve176causing it to compress the compression spring174. As the spring174compresses, the nub180is urged into contact with the limit switch172, deactivating the reversible drive motor132.

The extension stop mechanism156includes an open cup182depending from the lower aperture130of the gearbox122. A limit switch184, preferably in the form of a microswitch, is mounted within the storage compartment24adjacent the open cup182. A trigger186is mounted within the open cup182and movable between a first position where it engages the limit switch184and a second position where it does not engage the limit switch. The trigger186is preferably biased to the second position. A projection188, preferably in the form of the spherical mounting on the exterior of the vacuum hose28is sized to enter the open cup182and move the trigger186to the first position as the vacuum hose28approaches its maximum extension, thereby engaging the limit switch184. The limit switch184is electrically connected to the reversible drive motor132, preferably by way of the PCB in a manner that when it is engaged, the reversible drive motor132is deactivated. Moreover, the size of the projection188is such that further extension of the vacuum hose28is prohibited by the contact the projection188with the open cup182or the lower aperture130of the gearbox122.

It is within the scope of the invention for the retraction stop mechanism154or the extension stop mechanism156, or both, to be utilized with a hose drive assembly30in any vacuum system, whether or not incorporated in the present embodiment. For example, they can be used in portable vacuum systems, wall-mounted vacuum systems, and central vacuum systems.

Looking nowFIG. 11, the handle32comprises a grip portion180, and a nozzle portion182. The nozzle portion182preferably extends an obtuse angle relative to the longitudinal axis of the grip portion180. The nozzle portion182is also sized to frictionally receive one or more vacuum attachments54,117either stored in the lower compartment or cradled in the portable vacuum unit46.

It is contemplated that control of the vacuum motor82and control of the hose drive assembly30will be wireless from the handle32. Thus, a transmitter enclosed in the handle32will transmit signals from an “on” switch to turn on the vacuum motor82, and an “off” switch to turn off the vacuum motor82, a “forward” switch to actuate the reversible drive motor132in the extending direction, and a “reverse” switch to actuate the reversible drive motor132in a retracting direction. There may also be an “off” switch to turn off the reversible drive motor132between the extension and retraction limits. In the present embodiment of the handle32illustrated inFIG. 11, the “on” switch and “off” switch for the vacuum motor82are encompassed in a single toggle key185, the forward switch is actuated by a forward key187, and the reverse switch is actuated by a reverse key189. The “off” switch for the reversible drive motor132can be either a separate key, or preferably toggled from either the forward key187or the reverse key189. Preferably, the RF frequency for transmission is 433 MHz, and the modulation method is ASK.

The handle32also has a light191, preferably an LED, which activates whenever the “on” switch is activated. The light191is preferably directed in same direction as the nozzle182to provide illumination to the area to be vacuumed by the nozzle. It is within the scope of the invention for the handle light191to be utilized in any vacuum system, whether or not incorporated in the present embodiment. For example, it can be used in portable vacuum systems, wall-mounted vacuum systems, and central vacuum systems.

Looking now also atFIG. 12, the electronic interaction among the various components is illustrated schematically. The cabinet12houses the gearbox122, which includes the reversible drive motor132. A receiver190is located in the cabinet12, preferably in the enclosure52. Also, a controller194, preferably disposed in the enclosure52of the lower compartment44, includes a processor192. The controller194is electrically connected on the one hand to the gearbox122(preferably to the PCB connected to the reversible drive motor132), and on the other hand to a power socket196also disposed in the enclosure52. The handle32is connected to the cabinet12by way of the vacuum hose28, but electrically, a wireless connection is preferred. The portable vacuum unit46, as explained above, is a separate device. A user wishing to use the portable vacuum unit46apart from the cabinet12need only plug the electrical cord104into a conventional power socket using the plug105, and turn on the power switch102.

In this embodiment in order to use the portable vacuum unit46with the vacuum hose28of the cabinet12, the user must do three things, manually, once the portable vacuum unit is installed in the cabinet: (1) connect the conduit38to the vacuum port92, (2) plug the electrical cord104into the power socket196, and (3) turn on the power switch102. It will be understood that when the portable vacuum unit146is so docked, no power is delivered to the power socket196; the portable vacuum unit is placed only in a condition of readiness for operation.

All control of the vacuum system10can thereafter be accomplished entirely from the handle32. Pressing the toggle key185to actuate the “on” switch sends a coded signal to the receiver190, whereupon the processor192decodes the signal and energizes the power socket196. Conversely, pressing the toggle key185to actuate the “off” switch sends a coded signal to the receiver190, whereupon the processor192decodes the signal and de-energizes the power socket196. Similarly, pressing the forward key187sends a coded signal to the receiver190, whereupon the processor192decodes the signal and turns on the reversible drive motor132in the extending direction. The vacuum hose28will be automatically extended from the hose storage compartment24during actuation of the hose drive assembly30, and the user can guide the extension of the hose with the help of the handle32to the fully extended position, whereupon the hose drive assembly30will be shut off by the extension stop mechanism156. If the user wanted the vacuum hose28to be partially extended, pressing the forward key187again will stop the hose drive assembly30. By continually pressing the forward key187or the reverse key189, as needed, the user can position the vacuum hose28is desired.

It is within the scope of the invention for the forward key187and the reverse key189to provide continuous activation of the hose drive assembly30. In other words, as long as the forward key186is pressed between the extension and retraction limits, the reversible drive motor132will be energized in the extension direction. When the forward key187is released, the reversible drive motor132will be shut off. Similarly, as long as the reverse key189is pressed between the extension and retraction limits, the reversible drive motor132will be energized in the retraction direction. When the reverse key189is released, the reversible drive motor132will be shut off. In any event, it is contemplated that when the vacuum hose28is fully retracted and the limit switch162or172is actuated, the reverse key189will be inoperative so as to prevent damage to the hose. Similarly when the vacuum hose28is fully extended and the limit switch184is actuated, the forward key187will be inoperative so as to prevent damage to the hose. In order to stabilize operation of the reversible drive motor132, a step start of the motor is initiated preferably within the first second of actuation.

To prevent damage to the vacuum hose28and to the hose drive assembly30in the event the vacuum hose28becomes jammed during extension or retraction, an anti-jamming circuit198is provided. In the anti-jamming circuit198, a Hall effect sensor200is disposed in the gearbox122near a magnetic ring on the shaft of the reversible drive motor132. The Hall effect sensor200monitors the speed of the reversible drive motor132and sends a signal indicative of the speed to the processor192. The processor192is programmed to recognize a lower limit of normal speeds for the reversible drive motor132, say 3000 rpm. It is assumed that if the motor speed drops below 3000 rpm when neither an “off” switch nor a limit switch is activated, there is a jammed condition, and the controller194will turn off the reversible drive motor132. Preferably, the controller194will permit the system to reset to an operative condition only when the jamming problem is resolved.

Any one or all of the three manual operations for connecting the portable vacuum unit46to the cabinet12can be automated. For example, a mechanism can be provided to automatically bypass the power switch102when the portable vacuum unit46is mounted to the cabinet12, thereby obviating the need to turn on the power switch. Two variations of such a mechanism are illustrated inFIGS. 13-16. In the first variation shown inFIGS. 13 and 14, a protrusion202extends from the rear wall18of the cabinet12. Some portion of the portable vacuum unit46, preferably the motor housing58has an aperture204sized to receive the protrusion202. A switch module206is disposed immediately behind the aperture204and comprises a button208movably connected to a wall210. A reed switch212is mounted adjacent to the path of movement of the button208. The button208carries a magnet214, and is biased to a position where the magnet214is not adjacent the reed switch212, yet is positioned to contact the protrusion202when the protrusion is received in the aperture204.

As the portable vacuum unit46is mounted in the cabinet12, as for example by resting on the ledges48as explained above, the motor housing58is brought near the rear wall18of the cabinet12. The aperture204is located such that it goes over the protrusion202. Simultaneously as the protrusion202extends through the aperture204, it bears against the button208, and urges the button to move against its bias toward the wall210. As the button208moves, the magnet214passes the reed switch212, activating it. Actuation of the reed switch212energizes a coil216that, in turn, triggers a relay218to close a circuit between the electrical cord104and the vacuum motor82. Thus, upon placement of the portable vacuum unit46within the cabinet12, the user need not perform the manual operation of turning the power switch102on because the power switch is effectively automatically bypassed by triggering the relay218.

An alternative to the aforementioned bypass circuit is shown inFIGS. 15-16where like components bear like reference numerals. The difference in this circuit is that instead of using the more complex magnetically operated reed switch with coil and relay, a simple microswitch220is mechanically actuated by the button208.

Another manual operation the can be automated is connecting the conduit38to the vacuum port92. An example of a structure to accomplish this operation is shown inFIG. 17. The conduit38extending from the vacuum hose28into the lower compartment44has an extension220projecting outwardly from the rear wall18. A female coupler222is located on the end. The portable vacuum unit46has a conduit224extending rearwardly from the vacuum port92on the end of which is a male coupler226. The couplers222,226slidably mate, and one or both has a flexible sealing gasket to seal the connection, at least when a vacuum is drawn through the conduits220,224. Thus, as the portable vacuum unit46is placed within the cabinet12, as for example to rest on the ledges48, the male coupler226is simultaneously received within the female coupler222to automatically connect the conduit38to the vacuum port92.

It is further contemplated that an automatic power connection can be obtained upon docking the portable vacuum unit46to the cabinet12in at least a couple ways. In one alternative, the electrical cord104can be mounted on a spring-biased reel in the portable vacuum unit46. When fully reeled in, only the plug105projects from the portable vacuum unit46. The power socket196can be disposed within the lower compartment44so that as the portable vacuum unit46is docked (for example, to rest on the ledges48), the plug105is simultaneously urged into the socket196. In another alternative, a separate electrical coupling can be provided between the portable vacuum unit46and the cabinet12, with a bypass circuit in the portable vacuum unit to bypass the electrical cord104for delivery of power to the vacuum motor92.

It has been found desirable to provide a clutch mechanism to disengage the vacuum hose28from the reversible drive motor132so that it can be manually extended or retracted, for example in the event of the power failure. An embodiment of such a clutch mechanism is illustrated inFIGS. 18A-C.FIGS. 18A and 18Billustrate the three shafts136,140, and146on which the spur gears134,138, and144are respectively mounted. The vacuum hose28is shown in its relative position. The drive spur gear134has a clutch mechanism250interposed between it and the worm252on the shaft of the reversible drive motor132. The worm252engages a worm gear254mounted on the shaft136and spaced from the drive spur gear134. One of the worm gear254and the drive spur gear134rotates freely on the shaft136; the other is fixed and rotates with the shaft136. A generally cylindrical coupler256is slidably mounted on the shaft136between the worm gear254and the drive spur gear134. The coupler256has an intermediate radial flange258, with a spur keyway260on the cylindrical wall facing the drive spur gear134, and a worm keyway262on the cylindrical wall facing the worm gear254. A worm key264extends from the shaft136and into the worm keyway262. A spur key266extends from a collar268on the drive spur gear134, and is sized to be received within the spur keyway260. The coupler256is biased by a compression spring270(between the worm gear254and the radial flange258) so that the spur key266is received by the spur keyway260, as shown inFIG. 18A. When the coupler256is so positioned, the drive spur gear134rotates with the worm gear254.

A lever272is pivotally mounted to the gear box122so that one arm bears against the radial flange258and the other arm (either directly or by linkage) projects through a control plate274(seeFIG. 18C). The control plate274has an L-shaped slot276where the lever272can be moved between an engaged position278and a disengaged position280. The “L” portion of the slot276can provide for a hold position282where the lever can be retained in a disengaged position.

Looking now atFIG. 18A, it can be seen that when the lever272is in the engaged position278, the coupler256is biased so that the spur key266is received in the spur keyway260, thus engaging the vacuum hose28with the reversible drive motor132. Looking now at fig year18B, it can be seen that when the lever272is in a disengaged position280, the arm bears against the radial flange258to urge the coupler256away from the drive spur gear134so that the spur key266is out of the spur keyway260. In this position, the drive spur gear134is free to rotate relative to the worm gear254, and consequently free to rotate relative to the reversible drive motor132. Thus, the vacuum hose28is disengaged from the reversible drive motor132and free to be manually retracted or extended as desired. In the hold position282, the lever272is retained in a disengaged position against the bias of the compression spring270.