Abstract:
A floor care machine with an adjustable handle assembly that allows an operator to quickly and conveniently adjust the angular position of the handle relative to the floor working unit is provided. The handle adjustment assembly allows the operator to select the handle position by hand without bending or otherwise placing the operator in a non-preferred ergonomic position. The handle adjustment assembly features a clamping mechanism with an adjustment lever for securement and release of a frictional grip of the main handle member to maintain the position of the handle relative to the floor working unit.

Description:
FIELD OF THE INVENTION 
     The present invention relates to floor care machinery and more particularly to an infinitely adjustable handle with a releasable clamp for floor care machines such that the operator may position the handle so as to optimize the operator&#39;s control of the machine and ergonomic correctness. 
     BACKGROUND OF THE INVENTION 
     Various types of floor care machines are currently available in the marketplace including machines that scrub, sweep, polish and/or burnish the floor surface. Such floor care machines typically include a base, an electric motor coupled to the base and a handle attached to the base for guiding and operating the floor care machine. Presently available floor care machines can provide for adjustment of the handle relative to the base. Many floor care machines are electrically powered, often requiring power cords. The handle designs of many of the floor care machines with associated electrical cords incorporate hooks for coiling the cord during periods of non-use. 
     One known handle adjustment mechanism provides a low-mounted cam-action lever, mounted directly to the base, which tightens a clamp that is otherwise free to slide on the handle. This mechanism allows for continuous adjustment of the handle relative to the base, but has a major disadvantage. The operator must either use a foot to actuate the clamp lever or bend over to reach the low-mounted lever by hand. Operating the lever by foot is acceptable when shifting the lever downward, but is ergonomically poor and difficult when shifting the actuator upward. The operation of the low-mounted lever by hand is ergonomically improper because the operator must exert force while bending or kneeling. 
     Another known handle adjustment mechanism provides a high-mounted handle release for a pawl and gear, or a pawl and notched plate. With this mechanism, the operator can select from a “storage” position (typically vertical) and several “working” positions. The operator actuates a release lever to disengage the pawl from the gear or notched plate. Once the handle is positioned as desired, the operator releases the lever such that the handle settles into the nearest gear or notch. This adjustment mechanism can suffer from certain drawbacks. First, it is relatively expensive and complex to manufacture, thus generally relegated to expensive, feature-rich machines. Second, this mechanism limits the operator to a few specific handle positions. Unless the handle coincidentally falls into an ideal position, the operator is forced to work in an incorrect position. Third, this mechanism typically is subject to manufacturing tolerances and, hence, the handle position will have some “play” or “slop.” This noticeable looseness in the handle position reduces the operator&#39;s necessary precision in controlling the floor care machine, especially in low speed polishers where precise control can be crucial. 
     Yet another known handle adjustment design employs an expandable split ring mechanism on the interior tube of concentric, telescoping tubes to provide a releaseable friction clamp. While this design provides a high-mount handle and continuous adjustment, this split ring configuration appears to increase the cost of machine manufacture and assembly thereof. Moreover, the interior location of the clamping mechanism may make repair and maintenance challenging and time consuming. 
     In view of these perceived deficiencies in known floor care machines, it would be beneficial to provide an adjustable handle for a floor care machine in which the operator may conveniently and quickly adjust the handle to the desired location. It would also be advantageous to provide the operator of a floor care machine with a high-mounted lever to adjust the handle without placing himself or herself in an ergonomically undesirable position. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention, an adjustable handle assembly for floor care machines is disclosed. The adjustable handle assembly allows the operator of a floor care machine to conveniently adjust the handle unit of the machine relative to the floor working unit of the machine. Proper adjustment gives the operator optimal control over the floor working unit while working in a proper ergonomic position. 
     The floor machine of the present invention includes a floor working unit, a main handle assembly, and a handle adjustment assembly. The floor working unit performs the desired surface treatment, hence may include a scrubber pad or a burnishing disc. The main handle assembly is connected to the floor working unit and includes a gripping handle. The gripping handle is the means by which the operator grasps and controls the floor machine. The handle adjustment assembly includes an adjustment member and a locking assembly with an adjustment lever and a clamping mechanism. The operator of the floor machine may adjust the position of the main handle assembly by releasing the locking assembly, positioning the main handle assembly as desired, and securing the locking assembly. The release and securement of the locking assembly can be performed by moving the adjustment lever which actuates the clamping mechanism. 
     In another embodiment, the main handle assembly may include a main handle member. The main handle member may be a tube or a solid shaft. The adjustment member of the handle adjustment assembly is moveable relative to the main handle member. The handle adjustment assembly and the main handle member can be concentric tubes with the main handle member interior to the handle adjustment assembly. 
     The clamping mechanism of the handle adjustment assembly may include a first clamp block and a second clamp block, although a single, split block could be used. In the embodiment having two blocks, the clamp blocks are interconnected and attached to the handle adjustment assembly and are located exteriorly to the main handle member. The first clamp block may be moved toward or away from the second clamp block by moving the adjustment lever. The clamping mechanism may also contain an adjustment rod connected to the adjustment lever and the first and second clamp blocks. The adjustment rod can be pivotally connected to the adjustment lever and moveably connected to both the first clamp block and the second clamp block. The adjustment lever may incorporate a cam-type design on its contact surface with the first clamp block. The cam-type interface provides for the tensioning and release of the adjustment rod by positioning the adjustment lever along the cam surface. 
     The relative position of the main handle member to the handle adjustment assembly may be secured by pivoting the adjustment lever such that the first and second clamp blocks moved towards each other. The first and second clamp blocks frictionally grip the main handle member. 
     The handle adjustment assembly may also incorporate a lower block on the opposite end of the handle adjustment assembly from the first and second clamp blocks. The lower block may provide a mounting surface for two link arms. The link arms are attached to the lower block and may be pivotally connected to the main handle assembly or the floor working unit. Thus, the link arms maintain a spatial relationship between the lower block and either the main handle assembly or the floor working unit. The lower block may also incorporate a lower power cord wrapping member for storage of a power cord during periods of non-use. The power cord may be wrapped around the lower power cord wrapping member and the gripping handle. The main handle assembly may incorporate an upper power cord wrapping member. In this embodiment, the power cord is wrapped around the lower and upper power cord wrapping members, leaving the gripping handle unencumbered by the cord. 
     Based on the foregoing summary, a number of worthwhile aspects of the present invention can be readily identified. A floor machine is provided with a simple and convenient way of adjusting the handle of a floor machine relative to the base unit. The operator of the floor care machine may grasp and actuate the adjustable lever while holding the gripping handle. Since the adjustable lever is near the gripping handle, the operator need not place himself or herself in a physically compromising position to adjust the handle. The selection of an operating position is equally simple, since the operator need only to pivot the adjustment handle to secure the handle position. The simplicity of the design may reduce manufacturing costs such that the adjustable handle design of the present invention is available even on the less expensive models of floor care machines. Finally, the inherent design of the handle adjustment assembly is such that distance from the lower power cord wrapping member and the gripping handle, or the upper power cord wrapping member if so equipped, is greatest in the stored position. This allows the operator to quickly and easily remove the cord, without unwinding it, by simply lowering the handle from the storage position and placing the cord aside. 
     Additional advantages of the present invention will become readily apparent from the following discussion, particularly when taken together with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the floor care machine of the present invention with the adjustable handle shown in the stored position and in an operating position; 
     FIG. 2 is an exploded view of the handle adjustment assembly of the present invention; 
     FIG. 3 is a partial cross-sectional view of the clamping mechanism of the present invention; 
     FIG. 4A is an elevation view of the floor care machine of the present invention in the stored position; 
     FIG. 4B is an elevation view of the floor care machine of the present invention is an operating position. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With reference to FIG. 1, a floor machine  8  with a floor working unit  10  and an adjustable handle unit  20  is illustrated. The floor working unit  10  typically comprises a motor  12  mounted on a disc housing  14 . The motor  12  drives a floor working pad (not shown) selectively chosen to accomplish the desired floor work, i.e., polishing or burnishing. The motor  12  drive shaft extends through the disc housing  14  and attaches to the floor working pad. The floor working unit  10 , as shown, includes a frame  16  for connecting the handle unit  20  with the floor working unit  10 . Two wheels  18  are connected to the frame  16  to facilitate transportation of the floor machine  8 . Other embodiments of the floor working unit  10  may be employed. For example, the disc housing  14  may be a solid casting with built-in connection brackets for the handle unit  20  and wheels  18 . 
     The handle unit  20  of the present invention includes a main handle member  26  and a main handle assembly  22 , including a gripping handle  24  and a floor working unit engagement lever  25 . The main handle member  26  is pivotally connected to the floor working unit  10  at one end. The main handle assembly  22  is attached to the main handle member  26  at the opposite end from the floor working unit  10 . 
     The handle adjustment assembly  28  includes an adjustment member  30 , a clamping mechanism  44 , with an adjustment lever  38 , and a lower block  64 , as seen in FIG.  2 . The adjustment member  30  is a sleeve sized to receive the main handle member  26  such that the handle adjustment assembly  28  is free to travel axially along the exterior of the main handle member  26  when the clamping mechanism  44  is disengaged by the adjustment lever  38 . The clamping mechanism  44  and the lower block  64  are attached to the adjustment member  30  at opposite ends of the adjustment member  30 . The lower block  64  is connected to the floor working unit  10  by a first link arm  66  and a second link arm  68 . The link arms  66  and  68  maintain the spatial relationship between the lower block  64  and the floor working unit  10 . In the preferred embodiment, a lower cord wrapping member  76  is attached to the lower block  64 . 
     FIG. 2 illustrates the handle adjustment assembly  28  of the preferred embodiment in exploded view. The adjustment assembly  28  includes the lower block  64  attached at the lower end of the adjustment member  30  and a clamping mechanism  44  at the upper end of the adjustment member  30 . 
     Referring to FIG. 2, the clamping mechanism  44  includes a first clamp block  46  and a second clamp block  48 . The first clamp block  46  is attached to the second clamp block  48  along the two lateral edges of the first and second clamp blocks  46  and  48 . Along one lateral edge, the first clamp block  46  is attached to the second clamp block  48  with a clamp block bolt  50 , a clamp block washer  52 , and a clamp block nut  54 . The clamp block bolt  50  is inserted through the first clamp block  46  and second clamp block  48 . The clamp block bolt  50  secures the first clamp block  46  to the second clamp block  48  by placing the clamp block washer  52  onto the clamp block bolt  50  after it is inserted through the first and second clamp blocks  46  and  48  and then threading and tightening the clamp block nut  54  onto the clamp block bolt  50 . As shown in FIG. 2, the first clamp block  46  may include a clamp block bolt head recess  56  for receiving the head of the clamp block bolt  50 . The clamp block bolt head recess  56  prevents rotation of the clamp block bolt  50 , and thus enables the clamp block nut  54  to be tightened using only one wrench. Along the second lateral edge, the first clamp block  46  is attached to the second clamp block  48  with an adjustment rod  58 . The adjustment rod  58  may be a rod having a threaded end and a flattened end. The flattened end has an aperture for receiving the adjustment lever securement device  42  which connects the adjustment lever  38  to the adjustment rod  58 . The adjustment lever  38  is attached to the adjustment rod  58  by placing the adjustment lever washer  40  onto the adjustment rod  58 . The adjustment lever washer  40  has a slot sized to receive the flattened end of the adjustment rod  58 . The adjustment lever  38  has gripping end and a cam surface end. The cam surface end of the adjustment lever  38  includes a groove sized to receive the flattened end of the adjustment rod  58  and an aperture to receive the adjustment lever securement device  42 . The groove for receiving the flattened end of the adjustment rod  58  is perpendicular to the aperture for receiving the adjustment lever securement device  42 . The adjustment lever  38  is attached to the adjustment rod  58  by inserting the flattened end of the adjustment rod  58  into the groove in the adjustment lever  38  and inserting the adjustment lever securement device  42  through the aligned apertures in the adjustment rod  58  and the adjustment lever  38 . The adjustment rod  58  is inserted through the first clamp block  46  and the second clamp block  48 . The adjustment rod  58  is then secured to the first and second clamp blocks  46  and  48 , in the manner described above for the clamp block bolt  50 , by the adjustment rod washer  60  and the adjustment rod nut  62 . 
     The first and second link arms  66  and  68  are attached to the handle adjustment assembly  28  at the lower block  64 . Apertures for receiving a link arm bolt  70  are provided in the one end of the first and second link arms  66  and  68  and the lower block  64 . The apertures of the first and second link arms  66  and  68  are aligned with the aperture in the lower block  64  on opposite sides of the lower block  64 . The link arm bolt  70  is inserted through the first link arm  66 , the lower block  64 , and the second link arm  68 . The link arm bolt is secured by a link arm washer  72  and a link arm nut  74 . 
     FIG. 3 illustrates the clamping mechanism  44  in its secured position. The main handle member  26  is received into the adjustment member  30 . The adjustment lever  38  may be pivoted about the adjustment lever securement device  42 . The cam surface end of the adjustment lever  38  operates to force the first clamp block  46  and second clamp block  48  together by creating tension in the adjustment rod  58  as secured by the adjustment rod washer  60  and the adjustment rod nut  62 . The tension in the adjustment rod  58  is maintained by a landing on the cam surface end of the adjustment lever  38 . The main handle member  26  and the adjustment member  30  are held in relative position to one another by the friction created by the above-described clamping action between the main handle member  26  and the first and second clamp blocks  46  and  48 . 
     FIG.  4 A and FIG. 4B illustrate an additional feature of the present invention. FIG. 4A shows the floor machine  8  in the “stored” position; the handle unit  20  is vertical in this position. Dimension “X” is the distance between the lower cord wrapping member  76  and the gripping handle  24  when the handle unit  20  is in the stored position. FIG. 4B shows the floor machine  8  with the handle unit  20  in one possible working position. Dimension “Y” is the distance between the lower cord wrapping member  76  and the gripping handle  24  when the handle unit  20  is in a working position. 
     Dimension “X” is always greater than dimension “Y.” Thus, if the floor machine power cord (not shown) is wrapped around the lower cord wrapping member  76  and the gripping handle  24  for storage, the power cord can be easily removed and set aside when the handle unit  20  is lowered into operating position. This feature also exists when the main handle assembly  22  contains an upper cord wrapping member (not shown), provided the upper cord wrapping member is mounted on the handle assembly above the adjustment member  30 . Most logically, the upper cord wrapping member would be mounted on the main handle assembly  22  such that it does not interfere with the gripping handle  24 , the floor working unit engagement lever  25 , or the movement of the adjustment member  30  along the main handle member  26 .