Abstract:
A shower-mounted back-scrubber device is installed on the wall of a shower stall at a height approximating the height of the user&#39;s back. The device has a pair of scrub brushes that rotate and reciprocate vertically. The user stands comfortably with his or her back abutting the device. The brushes traverse and clean the entire surface of the user&#39;s back without awkward manual manipulation or translation relative to the device. The brushes are motor-driven by a drive shaft connecting the motor to a transmission. The transmission and drive shaft have a telescoping connection that permits positioning a housing of the device relative to the motor. A controller regulates rotational and reciprocal speed of the brushes.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a device for scrubbing and massaging the human body, especially the back. 
       BACKGROUND OF THE INVENTION 
       [0002]    There are a wide variety of known devices that enable a person to more easily scrub his or her back while showering. Back brushes having sponges, pads or bristles fixed to an elongate handle may be the most basic back scrubbing device. While relatively inexpensive and commonplace, back brushes have limited effectiveness for scrubbing the surface of the back and provide no massaging effect for the muscles of the back. Further, a person with limited flexibility or other handicap may not be able to properly manipulate a back brush behind the head, neck and/or back. Therefore, it would be desirable to provide a back scrubbing device that does not require awkward manual manipulation to clean the entire surface of the back. 
         [0003]    Another form of back scrubbing device generally consists of one or more stationary brushes, sponges, cleansing pads or the like connected to a housing unit, which is removably or permanently fixed to a vertical surface in the shower. Examples of such devices are disclosed by Brignoni in U.S. Pat. No. 7,175,357, Brown in U.S. Pat. No. D444,916, Swann in U.S. Pat. No. D450,158, Jackson in U.S. Pat. No. 5,517,705, and Jahnke in U.S. Pat. No. 5,704,903. Such devices require the user to lean against the cleansing surface and then translate both vertically and horizontally relative to the cleaning surface until the cleaning surface has traversed the entirety of the user&#39;s back. 
         [0004]    For a person with limited flexibility or mobility, and even healthy persons, translating one&#39;s torso while maintaining good contact with the cleansing surface is difficult and dangerous, especially when standing on a wet shower floor. Further, these devices provide no massaging effect on the muscles. 
         [0005]    A similar but more complex form of back scrubbing device consists of one or more rotating brushes, sponges, cleansing pads or the like connected to a housing unit, which is removably or permanently fixed to a vertical surface in the shower. Examples of such devices are disclosed by Roach in U.S. Pat. No. 6,058,545, Richardson in U.S. Pat. No. 7,062,815, Goss in U.S. Pat. No. 5,345,640, Clark, Jr. in U.S. Pat. No. 6,996,861, and Sarel in U.S. Pat. No. 5,561,869. Such devices have cleaning brushes that are rotated by motors or impellers. While more effective than stationary brushes, such devices still require the user to translate both vertically and horizontally relative the cleaning brushes. Therefore, it would be desirable to provide a back scrubbing device that does not require the user to translate relative to the device in order to clean the entire surface of the back. 
       SUMMARY OF THE INVENTION 
       [0006]    The invention comprises a device for scrubbing the human body, and in particular the user&#39;s back. In a preferred embodiment, the device is installed on the wall of a shower stall at a height approximating the height of the user&#39;s back. The device has a pair of scrub brushes that rotate and reciprocate vertically. The user stands comfortably with his or her back abutting the device. The brushes traverse and clean the entire surface of the user&#39;s back without awkward manual manipulation or translation relative to the device. 
         [0007]    The device has a housing that can be releasably mounted to a wall within the shower. The brushes are mounted on a carrier within the housing. The carrier and brushes are driven by a motor through a transmission connecting the motor to the carrier. The transmission simultaneously rotates and vertically reciprocates the scrub brushes relative to the housing. The carrier, transmission and brushes are mounted on the housing while the motor is remote from the housing and adjustably connected to the transmission by a drive shaft. The transmission and drive shaft have a telescoping connection that permits the housing to move distally and proximally relative to the motor. 
         [0008]    In a preferred embodiment, the pair of brushes simultaneously rotates in opposite directions. A controller regulates the rotational and reciprocal speed of the brushes. A single motor drives both rotational and vertical movement. 
         [0009]    The transmission includes a worm gear assembly for reciprocating the brushes vertically and a pair of pinion gear assemblies for rotating the brushes. The gear of the worm gear is fixed to the carrier and the worm of the worm gear assembly is rotatably mounted on the housing. The gear of the worm gear assembly is centrally located on the carrier. The pinion gear assemblies are located on each side of the worm gear assembly. The pinions of each pinion gear assembly are rotatably mounted on opposed sides of the carrier. The racks of the pinion gear assemblies are mounted on opposed sides of the worm of the worm gear assembly. The racks are fixed parallel to and equidistantly from the worm and lie generally vertically along the shower wall. The pinions include fixed shafts extending from the central axis. The brushes are removably fixed to the pinion shafts. 
         [0010]    The scrub brushes reciprocate vertically between upper and lower limit positions. The device includes contact switches that reverse the direction of travel of the brushes at the limit positions. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is a perspective of a back scrubbing device installed in a shower stall in accordance with an embodiment of the invention; 
           [0012]      FIG. 2  is an exploded perspective of the back scrubbing device of  FIG. 1 ; 
           [0013]      FIG. 3  is a cross section taken along lines  3 - 3  of  FIG. 1 ; 
           [0014]      FIG. 4  is a cross section taken along lines  4 - 4  of  FIG. 3 ; and 
           [0015]      FIG. 5  is a cross section taken along lines  5 - 5  of  FIG. 3 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0016]    For the purpose of illustrating the invention, an embodiment of the invention is shown in the accompanying drawings. However, it should be understood by those of ordinary skill in the art that the invention is not limited to the precise arrangements and instrumentalities shown therein and described below. Throughout the specification, like reference numerals are used to designate like elements. 
         [0017]    A device for scrubbing the human body in accordance with an embodiment of the invention is illustrated in  FIGS. 1-5  and is designated generally by reference numeral  10 . The device  10  is illustrated in  FIG. 1  installed in a shower stall  6  and is described below with reference to that environment. However, it should be appreciated that the device  10  can be installed and used in other environments wherein people bathe such as a bathtub surround or the shower walls of a locker room. 
         [0018]    The device  10  is also shown mounted to a vertical surface  8  within the stall  6  at a height approximating the vertical distance to the middle of the back of an average person. However, it should be appreciated that the device  10  could be mounted at a lower height and used in a similar manner to scrub and massage a person&#39;s lower torso, legs, or feet. To accomplish this, the device may be slidably mounted on two parallel rails  11   a  and  11   b  affixed to the shower wall so that the device  10  can be adjustably mounted within a range of heights and can be easily adjusted. 
         [0019]    Referring to  FIG. 1 , the device  10  has a generally-rectangular main housing  12  having front  12   a , back  12   b , top  12   c , bottom  12   d , left  12   e  and right  12   f  walls. The housing  12  is preferably made from a sturdy, corrosion-resistant material such as plastic. The width “w” and length “l” of the housing may vary but should preferably be large enough so that the brushes  18  can traverse an average adult person&#39;s back in a single stroke. For example, in the embodiment shown in  FIGS. 1-5 , the housing is about 25.4 cm wide and about 83.8 cm long. 
         [0020]    The housing  12  is preferably water-tight except for two vertically-extending slots  14  formed in the front wall  12   a , and several drainage holes  15  in the bottom wall  12   d  as best seen in  FIG. 5 . The slots  14  traverse nearly the entire length of the housing  12 . As best seen in  FIG. 3 , the housing  12  includes fasteners  16  fixed to the back side  12   b , which releasable secure the housing  12  to the vertical surface  8  of the shower stall  6 . In the embodiment shown in  FIGS. 1-5 , the fasteners  16  comprise suction cups but may comprise other types of releasable fasteners, such as double-sided tape, that do not puncture the vertical wall  8 . 
         [0021]    A pair of brushes  18  extends from the front wall  12   a  of the housing  12 . The brushes  18  reciprocate vertically within the slots  14  while they simultaneously rotate. In the embodiment shown in  FIGS. 1-5 , each brush  18  has a circular base  20 . Soft bristles  22  extend axially from one side of the base  20  and a socket  24  extending axially from the center of the other side of the base  20  and socket  24  may include a set screw  26  that threads into a radially-extending bore  28  to secure the brush  18  on one of the pinion shafts  50  as described below or may be removably attached by snap rings. By the removal of the brushes exchanged with rollers, the device may be converted from a scrubber to a massager. 
         [0022]    The brushes  18  are powered by a motor  30 , which is connected to a power source by electrical leads  32 . In the embodiment shown in  FIGS. 1-5 , the motor  30  sits on top of the sill of the shower stall  6  in a vertically-distal position from the main housing  12  to avoid direct contact from water expelled from the shower head or deflected off the user. 
         [0023]    A drive shaft  34  extends from the motor  30  and connects to a transmission inside the main housing  12 . An alternate design may include a DC motor driven by a power pack as is used in portable power tools. To protect the drive shaft  34  from corrosion and protect the user from injury, the drive shaft  34  is encased in a conduit  36 . Preferably, the conduit  36  comprises an upper section  36   a  and a lower section  36   b  that telescope so that the length of the conduit  36  can be adjusted to accommodate vertical height adjustment of the main housing  12  on the vertical wall  8  of the shower stall  6 . As described below, the manner in which the drive shaft  34  is connected to the transmission also accommodates vertical height adjustment of the main housing  12  on the vertical wall  8  of the shower  6 . 
         [0024]    The transmission simultaneously rotates the brushes  18  in opposite directions and reciprocates the brushes  18  vertically up and down. Vertical movement is generated by a worm gear assembly, which includes a worm  38 , worm gear  40 , and mounting brackets  42 . The worm  38  comprises a threaded shaft having a length approximating the length of the housing  12 . The worm gear  40  comprises a cylindrical segment having a threaded axial bore that meshes with the worm  38 . Rotation of the worm  38  causes the worm gear  40  to move upwardly and downwardly along the worm  38 . 
         [0025]    Referring to  FIG. 3 , the worm  38  has an axial bore  39 . The lower portion of the drive shaft  34  has a cross section that complements the cross section of the bore  39  so that the drive shaft  34  slides into the worm  38 . Preferably, the complementing cross-sections are not circular so that the drive shaft  34  and worm  38  can not rotate relative to one another. For example, the drive shaft  34  may be splined or have a square cross section. The irregular, complimenting cross sections allow the drive shaft  34  and worm  38  to freely telescope to accommodate vertical height adjustment of the main housing  12  on the vertical wall of the shower. 
         [0026]    Rotational movement of the brushes  18  is generated by two rack and pinion assemblies. As best seen in  FIG. 2 , a rack  44  is fixed to the back wall  12   b  of the housing on each side of the worm  38 . Each rack  44  is arranged parallel and equidistantly to the worm  38 . The racks  44  have a length approximating the length of the housing  12  and the worm  38 . Each rack  44  engages a pinion  46 . The pinions are mounted on opposed ends of a carrier  48  connected to the worm gear  40 . Cover plates  49  straddle each rack  44  to prevent the pinions  46  from running off the racks  44 . A square shaft  50  extends axially from the central axis of each pinion  46  through the elongate slots  14  in the front wall  12   a  of the housing  12 . Each square shaft  50  inserts into the socket  24  of one of the brushes  18 . 
         [0027]    In operation, the worm  38  is driven by the drive shaft  34 . As the worm  38  rotates, the carrier  48  is driven linearly vertically. The pinions  46 , which are held in engagement with the racks  44  by the carrier  48 , rotate as they translate along the racks  44 . This combined linear and rotational movement causes the brushes  18  to rotate while simultaneously reciprocating upwardly and downwardly to scrub and massage the user&#39;s back. The transmission maintains the brushes  18  at the same height in the shower enclosure during reciprocation so that a balanced force is applied to the user&#39;s back. 
         [0028]    The brushes  18  reciprocate vertically between upper and lower limit positions. In a preferred embodiment, the device  10  includes a contact switch  52  located near each end of the worm  38 . The switches  52  are electrically connected to the motor  30  by wires  54  that are encased in an electrical conduit  56 . Similar to the drive shaft conduit  36 , the electrical conduit has telescoping upper  56   a  and lower  56   b  sections. As the worm gear  40  approaches either end of the worm  38 , the carrier  48  contacts one of the switches  52 , which reverses the polarity in the motor  30  and reverses the direction of the brushes  18 . 
         [0029]    The scrubbing and massaging device  10  can be used by persons of varying heights by adjusting the vertical location of the main housing  12  on the shower wall  8 . To make the adjustment, the user need only release the set screws on the sliders which ride on rails  11   a  and  11   b  and reposition the main housing  12  at the desired height. The motor  30  remains in a fixed location. The length of the drive shaft  34  between the motor  30  and main housing  12  automatically adjusts by sliding freely in and out of the worm bore  39 . The user need not make any other mechanical adjustment. 
         [0030]    In a preferred embodiment, the motor  30  can be operated at variable speeds to control the speed of reciprocation and rotation of the brushes. In one embodiment, the motor  30  includes a control knob  58 , which activates and controls the speed of the motor  30  by rotating the knob  58  between limit positions. 
         [0031]    The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.