Abstract:
A vacuum cleaner includes a housing having a nozzle assembly and a handle. An agitator brush is mounted for relative rotation on the nozzle assembly. A motor and fan subassembly are mounted in the housing. A three position control switch is carried on the handle. The control switch is selectively positionable in an off position, a continuously on position and an automatic on/off touch control position whereby the motor is activated by squeezing the control switch assembly and deactivated by releasing the control switch assembly.

Description:
TECHNICAL FIELD 
     The present invention relates generally to the vacuum cleaner art and, more particularly, to a unique three position control switch assembly for a vacuum cleaner providing greater versatility and control convenience to the vacuum cleaner operator. 
     BACKGROUND OF THE INVENTION 
     Vacuum cleaners have long utilized snap action on/off switches in order to control the operational state of the motor or motors that drive the fan to produce the vacuum suction and drive the agitator brush that beats and scrubs dirt and debris from the nap of the carpet being cleaned. Such control switches have been provided at various locations. For example, many designs incorporate an on/off control switch on the lowermost portion of the housing adjacent the floor. Others incorporate an on/off control switch in the area of the hand grip of the handle. Still others incorporate an on/off control switch at an intermediate position, either along the handle below the hand grip or on the canister body which holds the dust bag. 
     While an on/off control switch on the housing adjacent the floor may usually be conveniently accessed for manipulation by means of the foot of the operator, it should be appreciated that many operators prefer to manipulate the on/off switch by hand. Thus, a switch mounted in such a low position inconveniently requires such an operator to stoop or squat in order to reach the switch which is a significant annoyance. 
     It should further be appreciated that an on/off control switch mounted on the lowermost housing portion of the vacuum cleaner is often difficult to reach. Specifically, as the vacuum cleaner is manipulated by the operator, the handle pivots relative to the lowermost portion of the housing covering the nozzle assembly. At certain pivot angles, an operator holding the hand grip cannot reach an on/off control switch on the nozzle housing with his/her foot or other means. Further, the nozzle body in some circumstances may be underneath a chair, table or other furniture which blocks the line of sight of the operator to the on/off control switch thereby preventing, for example, deactivation of the vacuum cleaner at a time when the fringe of a throw rug or other object is inadvertently drawn into the agitator brush. Of course, at such times rapid degenerization of the vacuum cleaner motor is desired and any delay may result in damage to the throw rug or even the vacuum cleaner. 
     Of course, it should also be appreciated that at certain pivot angles of the handle a switch along the intermediate portion of the handle or canister body may also be difficult to see and/or access readily in this type of emergency. Thus, at first it appears that the mounting of the control switch on the operator hand grip is the solution. Upon further consideration, however, it should be appreciated that such a hand grip mounted control switch is often inadvertently triggered as the operator applies the necessary force to manipulate the vacuum cleaner along the floor. This can be inconvenient and frustrating for the operator. Further, it should be appreciated that such a switch may make the hand grip uncomfortable to the operator as the vacuum cleaner is guided across the floor first pushing and then pulling in a reciprocating forward and backward motion. Accordingly, a need exists for a better solution and the development of a more versatile control switch which meets all the needs of the vacuum cleaner operator. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is a primary object of the present invention to provide a vacuum cleaner incorporating a novel three position control switch assembly overcoming the above described limitations and disadvantages of the prior art. 
     Still another object of the present invention is to provide a control switch assembly for a vacuum cleaner that provides greater versatility and ease of operation. 
     Still another object of the present invention is to provide a vacuum cleaner control switch assembly providing three distinct operating modes including an off position, a continuously on position and an automatic on/off touch control position whereby the motor of the vacuum cleaner is activated by squeezing the control switch assembly and deactivated by releasing the control switch assembly formed in the hand grip of the vacuum cleaner. Accordingly, sure positive control of the vacuum cleaner is provided at all times in accordance with the desire of the operator. 
     Additional objects, advantages and other novel features of the invention will be set forth in part in the description that follows and in part will become apparent to those skilled in the art upon examination of the following or may be learned with the practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the appended claims. 
     To achieve the foregoing and other objects, and in accordance with the purposes of the present invention as described herein, a vacuum cleaner is provided incorporating a novel three position control switch assembly convenience feature. The vacuum cleaner includes a housing having a nozzle assembly and a handle. An agitator brush is mounted for relative rotation on the nozzle assembly. A motor and fan subassembly are mounted in the housing. Either one or two motors may be provided for driving the fan and producing a vacuum suction and driving the agitator brush which beats and brushes dirt and debris from the nap of the carpet being cleaned. 
     The vacuum cleaner also includes the novel three position control switch assembly. This control switch assembly is mounted on the handle and includes an off position, a continuously on position and an automatic on/off touch control position. In this latter position, the motor(s) of the motor and fan subassembly is activated by squeezing the control switch assembly, located in the hand grip of the handle, and deactivated by releasing the control switch assembly. Thus, in this position when the hand grip assembly is grasped by the vacuum cleaner operator, the switch is closed and the motor is energized to allow vacuuming. In contrast, immediately upon release of the hand grip, the motor is deenergized. Hence, the vacuum cleaner is essentially made immediately responsive to the operator with the motor(s) being energized with a squeeze of the hand grip and deenergized with the release of pressure on the hand grip. 
     Preferably, the control switch assembly includes a switch lever and a cooperating switch lever lock for engaging the switch lever. The switch lever is mounted for pivotal movement relative to the hand grip of the handle and the switch lever lock is mounted to provide relative sliding movement along the handle. The control switch assembly further includes a microswitch and a linkage connecting the switch lever to the microswitch. In accordance with yet another aspect of the present invention, the switch lever includes a notch providing two stops and the switch lever lock includes a cooperating camming lug received in that notch. When the control switch assembly is in the off position the camming lever engages the first of those stops. When the control switch assembly is in the continuously on position, the camming lug engages the second of those stops. Cooperating cam faces on the switch lever and switch lever lock function to allow the switch lever lock to displace the switch lever into the off and continuously on positions from the intermediate, automatic on/off control position. 
     Advantageously, the control switch assembly incorporated into the vacuum cleaner of the present invention provides versatile operation that may be tailored to the needs of the vacuum cleaner operator. For example, in a first position, the switch lever lock functions to lock the switch lever in order to insure that the vacuum cleaner remains in an off position. This is true whether or not the hand grip is grasped and squeezed by the operator. Thus, the vacuum cleaner may be manipulated and moved by means of the hand grip without energizing the vacuum cleaner motor. This allows the operator to quietly guide the vacuum cleaner from place to place by grasping the hand grip even when operation of the vacuum cleaner motor is not desired. 
     In the on position, the switch lever lock engages the switch lever and maintains the motor in an energized state whether or not the hand grip is grasped by the operator. This is a desired operating condition when, for example, off the floor cleaning is being completed by means of the suction hose and auxiliary attachments. 
     Finally, in the third position the vacuum cleaner is energized when the operator grips and squeezes the control handle. When the control handle is released, however, the motor is deenergized. This is a preferred operating mode when, for example, vacuuming a child&#39;s bedroom where the operator must periodically move shoes, toys or other objects from the path of the vacuum cleaner. Thus, when the operator releases the hand grip to move the object, the motor is deenergized and the agitator brush ceases to rotate so that when the vacuum cleaner is stationary, a spot of the carpet is not subjected to needless wear by the agitator brush. When the operator then again grasps the control handle, the motor is reenergized and vacuuming continues. Advantageously, this “automatic response” is provided without any manipulation of a snap switch. Accordingly, operator convenience is maximized. 
     Still other objects of the present invention will become apparent to those skilled in this art from the following description wherein there is shown and described a preferred embodiment of this invention, simply by way of illustration of one of the modes best suited to carry out the invention. As it will be realized, the invention is capable of other different embodiments and its several details are capable of modification in various, obvious aspects all without departing from the invention. Accordingly, the drawings and descriptions will be regarded as illustrative in nature and not as restrictive. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawing incorporated in and forming a part of the specification, illustrates several aspects of the present invention and together with the description serves to explain the principles of the invention. In the drawing: 
     FIG. 1 is a perspective view of the vacuum cleaner of the present invention; 
     FIG. 2 is a detailed, schematical elevational view showing the control switch assembly in the continuously on position. 
     FIG.  3   a  is a view similar to FIG. 2 but showing the control switch assembly in the off position; 
     FIG.  3   b  is a view similar to FIG.  3   a  with the control switch assembly in the on/off touch control position and with the application of pressure on the hand grip and particularly the switch lever shown by phantom line; and 
     FIG. 4 is a detailed view similar to FIGS. 2,  3   a  and  3   b  but showing the control switch assembly in the continuously on position. 
    
    
     Reference will now be made in detail to the present preferred embodiment of the invention, an example of which is illustrated in the accompanying drawing. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference is now made to FIG. 1 showing, in perspective view, an upright vacuum cleaner  10  incorporating a three position control switch assembly  11  constructed in accordance with the teachings of the present invention. The overall basic design of an upright vacuum cleaner  10  is generally well known in the art. Specifically, the upright vacuum cleaner  10  includes a canister assembly  12  pivotally connected to a nozzle assembly  14  by means of a hinge assembly (not shown). A handle  16  is rigidly attached to the top of the canister assembly  12 . The handle  16  includes a hand grip  18  which carries the control switch assembly  11  for turning the vacuum cleaner on and off. Of course, electrical power is supplied through a cord (not shown). 
     At the lower portion of the canister assembly  12 , rear wheels  24  are provided to support the weight of the vacuum cleaner  10  and provide a pivot point about which the nozzle assembly  14  pivots when the height of the nozzle assembly is adjusted by manipulation of the height adjustment switch  26 . The operation of the height adjustment switch  26  and its cooperating mechanism are described in detail in U.S. Pat. No. 5,467,502 to Johnson et al. Of course, as is known in the art, a foot latch  28  locks the canister assembly  12  in an upright position shown in FIG. 1 in order to allow storage and off the floor cleaning. When the foot latch  28  is released, the canister assembly  12  may be pivoted relative to the nozzle assembly  14  in a manner well known in the art. 
     The canister assembly  12  also includes a motor  30  that drives a fan  32  which generates a negative pressure or vacuum suction in an internal chamber  34  which also houses a dust bag  36 . Nozzle assembly  14  includes, at its front portion, a nozzle  38  that houses a rotating agitator brush  40 . The agitator brush  40  is rotatively driven by the motor  30 . Specifically, the motor  30  includes a drive shaft that is connected to the agitator brush  40  by means of a belt  44  (not shown) in a manner well known in the art. Specifically, the motor  30 , fan  32  and brush  40  cooperate to brush and beat dirt from the nap of a carpet being cleaned and then draw dirt laden air into the chamber  34  and thorough the porous walls of the dust bag  36 . The bag  36 , of course, serves to trap suspended dirt and particles inside while allowing the air to pass freely through to the exhaust port  37 . 
     The three position control switch assembly  11  will now be described in detail with reference to FIGS. 2,  3   a ,  3   b  and  4 . As best shown in FIG. 2, the control switch assembly  11  includes a trigger or switch lever  42  pivotally connected to the housing at the hand grip  18  by means of the pin  46 . As shown, the switch lever  42  includes a projecting actuator pad  48  that extends through the opening  50  in the hand grip for relatively easy and comfortable engagement by the operator. Additionally, the distal end of the switch lever  42  includes an integral cam  52  that engages a cam lever  54  pivotally mounted to the housing by means of the pin  56 . The cam lever  54  is operatively connected to one end of a push rod linkage  58  that extends through the handle  16  of the vacuum cleaner and has an opposite end that engages a flat spring trip lever  59  for actuating a microswitch  60  mounted remote from the switch assembly  11  in the handle or the canister assembly  12 . 
     Thus, as should be appreciated from viewing FIG.  3   b , when the hand grip  18  is squeezed (note action arrow A) and the actuator pad  48  is thereby forced into the hand grip opening  50  as a result of the natural grip of the operator, the cam  52  engages the cam lever  54  causing it to pivot about the pin  56  (see phantom line position). This results in the push rod linkage  58  being extended against (note action arrow B) the lever  59  thereby closing the microswitch  60  and energizing the motor to provide vacuum cleaner operation. In contrast, when the hand grip is released, the switch lever  42  is biased by the flat spring trip lever  59  to the full line position with the actuator pad  48  extending from the hand grip opening  50 . In this position, the push rod linkage  58  is retracted (note action arrow C in FIG. 2) under the biasing force of the lever  59  causing the microswitch  60  to open thereby deengerizing the motor. 
     The actual operation of the switch lever  42  just described is controlled by means of the switch lever lock  62 . More specifically, the switch lever lock  62  engages the hand grip  18  so as to provide relative sliding movement along the hand grip. Specifically, the switch lever lock  62  includes an inwardly projecting leg  64  that extends through an elongated opening  66  in the hand grip  18 . A backing block  68  insures that the switch lever lock  62  does not pull free from the opening  66 . 
     As further shown in FIGS. 2,  3   a ,  3   b  and  4 , the leg  64  carries a camming lug  70 . Camming lug  70  projects laterally and is received in a cooperating notch  72  in the switch lever  42 . As shown, the notch  72  defines two stops  74 ,  76 . When the switch lever control assembly  11  is in the off position, the switch lever lock  62  is positioned so that the camming lug  70  engages the first stop  74  on the switch lever  42  (see FIG.  3   a ). This engagement prevents the operator from squeezing the actuator pad  48  into the opening  50 . Thus, pivotal movement of the switch lever  42  about the pin  46  is also prevented. As a consequence, the control switch assembly  11  is locked in an off position since the push rod linkage  58  cannot be extended to close the lever  59  on the microswitch  60 . This is, of course, true even if the hand grip is engaged by the operator of the vacuum cleaner since the engagement of the camming lug  70  with the first stop  74  prevents pivotal movement of the switch lever  42  and therefore, activation of the vacuum cleaner motor. 
     In the automatic on/off touch control position shown in FIG.  3   b , the switch lever lock  62  is moved in the direction of action arrow D into an intermediate position wherein the camming lug  70  is positioned in a gap between the first stop  74  and the second stop  76 . This gap provides the necessary clearance to allow pivotal movement of the switch lever  42 . Accordingly, when the hand grip  18  is disengaged or no squeezing pressure is exerted, the switch lever remains in the full line position shown in FIG.  3   b  and the motor  30  remains deenergized. However, when squeezing pressure is provided on the hand grip  18  (note action arrow A), the actuator pad  48  is depressed into the opening  50 . As a result, the switch lever  42  pivots about the pin  46 , the cam  52  engages the cam lever  54  which pivots about the pin  56  and the push rod linkage  58  is extended so as to close the lever  59  and thereby close the microswitch  60  (see phantom line showing in FIG.  3   b ). Accordingly, the vacuum cleaner motor  30  is then energized. In this way, the vacuum cleaner provides instantaneous response to operator manipulation in this position. Specifically, squeezing of the hand grip results in the energization of the vacuum cleaner motor and operation of the vacuum cleaner. Releasing of pressure on the hand grip results in the return of the control switch assembly to the position shown in full line in FIG.  3   b  and the deenergization of the motor. As should be appreciated, the free operation of the switch lever  42  between the on/off positions is provided as a result of the notch  72  which provides clearance for the camming lug  70  between the first and second stops  74 ,  76 . 
     When desired, the control switch assembly  11  may even be placed in a continuously on position shown in FIG.  4 . Specifically, in this position, the switch lever lock  62  is moved in the direction of action arrow D along the hand grip  18  so as to slide the camming lug  70  into engagement with the second stop  76 . The cooperating camming surfaces  78  and  80  on the respective camming lug  70  and switch lever  42  allows this movement and function to force the switch lever  42  to pivot about the pin  46  into the position as shown. This functions to also pivot the cam lever  54  and extend the push rod linkage  58  so as to close the lever  59  and the microswitch  60  thereby energizing the motor  30  of the vacuum cleaner  10 . In this position, the engagement of the camming lug  70  with the second stop  76  functions to maintain the vacuum cleaner continuously on until vacuum cleaner operation is interrupted by some other means such as when the electrical cord is unplugged or the control switch assembly  11  is moved to another position. Of course, it should be appreciated that when the control switch assembly  11  is returned to the off position, the cooperating camming surfaces  82  and  84  on the respective camming lug  70  and switch lever  42  function to allow the desired movement and force the switch lever  42  back into the position shown in FIG.  3   a  with the camming lug  70  engaging the first stop  74 . 
     In summary, numerous benefits result from employing the concepts of the present invention. Advantageously, the three position control switch assembly  11  allows the operating characteristics of the vacuum cleaner to be tuned to the desires of the operator. More particularly, the control switch assembly  11  may be placed in a continuously off or a continuously on position in accordance with standard snap action type switches prevalent in the prior art. As an added alternative and performance feature, the control switch assembly  11  also provides an automatic on/off touch control position. In this position when the operator squeezes the hand grip and particularly, the actuator pad  48 , the vacuum cleaner motor  30  is energized and vacuum cleaner operation is provided. When the operator releases the pressure on the hand grip or releases the hand grip all together, the vacuum cleaner motor is deenergized and vacuum cleaner operation ceases. 
     In many instances, this is a more desirable operating scheme since automatic operation is effectively provided without manipulation of a snap action switch. In fact, this is a desirable feature for both commercial and residential applications as the operator of the vacuum cleaner often has to move objects to vacuum and it is undesirable to leave the agitator brush in engagement with the carpet nap when the vacuum cleaner is maintained in a stationary position for any length of time. This causes excessive and undesired wear on the carpet nap. This problem is easily avoided with the present invention. 
     The foregoing description of a preferred embodiment of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. For example, the present three position switch finds equal utility when used on other devices such as, for example, extractors. The embodiment was chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally and equitably entitled.