Abstract:
An adjustable foot rest includes an elliptically-shaped foot pad having an upper surface and lateral sides. A pair of legs are eccentrically pivoted to the sides of the foot pad. Rotation of the legs provides a plurality of different height positions for the foot pad. A ratchet mechanism between the legs and the pad restricts rotation of the legs to a single direction.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to foot rests and more particularly to an adjustable foot rest, capable of supporting a user&#39;s feet at proper ergonomic heights and tilt angles. 
     The introduction of electronic data processing equipment, personal computers and word processing equipment in the office environment has increased the importance of proper posture and ergonomic fitting of equipment to the user. For example, keyboard supports are now provided which adjustably position the keyboard with respect to the user. In addition, office seating typically provides height and tilt adjustment. Also, a fairly wide variety of foot rests, or foot supports are presently available. Foot rests are provided to support the user&#39;s feet in an elevated and inclined position. Such support reduces fatigue, leg strain and lower back discomfort which is associated with extended periods of sitting. 
     A fixed position foot rest provides adequate or proper support for only a limited, average portion of the total population. Supports which are adjustable as to height and tilt angle are necessary to accommodate a wide range of users. Different attempts have been made to provide an adjustable foot rest. The available foot rests suffer from various problems, including complexity, difficulty in manufacture and use, and relatively high cost. Examples of prior adjustable foot rests may be found in U.S. Pat. No. 4,441,758 entitled ADJUSTABLE FOOT SUPPORT, issued on Apr. 10, 1984 to Fleischer and U.S. Pat. No. 4,549,767 entitled ADJUSTABLE FOOT SUPPORT, issued on Oct. 29, 1985 to Hampshire et al. 
     A need exists for an adjustable foot rest or foot support, which is reliable, relatively easy to use, adjustable in height and tilt and adaptable to a wide range of users, yet which is relatively easy and inexpensive to manufacture. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention, the aforementioned need is fulfilled. Essentially, an adjustable foot rest is provided which includes a foot pad having an upper surface and lateral sides. A pair of legs are pivoted to the lateral sides of the foot rest. Rotation of the legs provides for mechanical height adjustment of the foot pad upper surface. 
     In narrower aspects of the invention, the upper surface of the foot pad has an elliptical shape in side elevation. The elliptical shape allows the user to place his or her feet at angles from 0° to 22° at each of the mechanical height and tilt positions. Further, a ratchet mechanism is included to restrict rotation of the legs to one direction only. 
     The adjustable foot rest in accordance with the present invention provides for multiple height and tilt adjustments. Varying tilt angles are provided by a combination of mechanical height positions and the elliptical shape of the foot pad. The assembly is easy to use. The assembly is relatively inexpensively manufactured and reliable in operation. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of an adjustable foot rest in the present invention; 
     FIG. 2 is an exploded assembly view of the foot rest; 
     FIG. 3 is an elevational view or a ratchet member or detent washer incorporated in the present invention; 
     FIG. 4 is a side elevational view of the detent washer of FIG. 3; and 
     FIG. 5 a fragmentary partially sectioned view schematically illustrating the operation of the ratchet mechanism incorporated in the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A foot rest, in accordance to the present invention, is illustrated in FIG. 1 and generally designated by the numeral 10. Foot rest 10 includes a foot pad assembly 12 and a pair of rotatable legs 1 4, 16. As described in more detail below, legs 14, 16 are rotatably mounted at lateral sides 18, 20 of foot pad assembly 12. Each leg 14, 16 is generally rectangular in shape. Each leg includes lateral sides 22, 24, 26, 30. Caps 32 may also be included. Legs 14, 16 rotate together so that they both may be selectively positioned on the floor surface on one of the lateral sides 22, 24, 26, 30. In this fashion, mechanical height adjustment of foot pad assembly 12 is provided. 
     As best seen in FIGS. 1 and 2, foot pad subassembly 12 includes a molded plastic housing 34. Housing 34 defines a pair of bosses 36. Bosses 36 are molded integral at lateral sides 18, 20 of the foot pad assembly. Housing 34 defines an upper surface 38 which is recessed inwardly. A foot pad mat 40 is positioned within the recessed upper surface. Mat 40 defines nonslip bars 42 on its upper surface 44. Pad 40 is secured to housing 34 by a suitable adhesive. It is presently preferred that housing 34 be injection molded from an engineering plastic. Pad 40 is fabricated from a limited slip or rubberized pad-like material. 
     As seen in FIGS. 1 and 2, foot pad assembly 12 including housing 34 has an elliptical shape in side elevation. The elliptical shape allows the users to place their feet at angles from 0° at the upper portion 46 of housing 34 to approximately 22° at the bottom or lower portion 48. The available foot angles are provided at all mechanical height/tilt positions of the foot rest assembly. 
     An elongated shaft 52 extends between and through lateral sides 18, 20 of foot pad assembly 12. Shaft 52 extends through bosses 36 defined by the lateral sides of the foot pad housing. Each end 54 of shaft 52 may be knurled as seen in FIG. 2. Each leg 14, 16 is of identical construction with the legs being mirror images of each other. Legs 14, 16 are preferably molded from an engineering plastic material. An inner surface 56 of each leg defines a molded boss 58. Reinforcement ribbing 60 may be also provided. Boss 58 is located eccentrically of the lateral and vertical centerlines of each leg. As a result, the distances between boss 58 and each lateral side 22, 24, 26, 30 are different. Ends 54 of shaft 52 are fitted into bosses 58. In the alternative and as presently preferred, ends 54 of shaft 52 have a square cross section. Bosses 58 are also square in shape to receive ends 54. Legs 14, 16 are nonrotatably secured to shaft 52. Rotation of one leg, therefore, rotates the shaft and the remaining leg. 
     Shaft 52 is supported on foot pad housing 34 by bushings 72, 74. Each bushing 72 includes a hub portion 76 and a circular flange 78. Hub 76 defines a bore 80. Bushing 74 similarly includes a cylindrical hub portion 82, a circular flange 84 and a hub bore 86. Hubs 76, 82 are fitted into bosses 36 defined by foot pad housing 34. Shaft 52 extends through passages 80, 86 defined by the bushings. The bushings support shaft 52 for rotation within the housing. A Belleville or spring washer 90 is positioned on shaft 52 between leg 16 and bushing 74. A ratchet mechanism 92 is supported on shaft 52 at leg 14. 
     Ratchet mechanism 92 includes a ratchet or detent washer 96 and a ramp or pawl 98 on bushing 72. As best seen in FIGS. 3, 4 and 5 detent washer or ratchet member 96 is a generally circular disc-like member formed with a plurality of axially-extending leaf springs or ratchet teeth 102. Teeth 102 are integral with and flexibly joined or hinged to ratchet member 96 at ends 104. Opposite ends 106 of each ratchet 102 are freefloating. Leaf springs 102 are positioned spaced circumferentially around the disc at positions corresponding to the lateral sides 22, 24, 26 and 30 of legs 14. In addition, ratchet member 96 defines apertures 110, 112. Disc 96 is secured to leg 14 by suitable fasteners passing through apertures 110. A center aperture 111 is also included for shaft 52. Disc 96 will, therefore, rotate with axle 52 and legs 14, 16. 
     As seen in FIGS. 2 and 5, pawl 98 is an angled ramp formed on flange 78 of bushing 72. Bushing 72, since it is press-fitted to foot pad housing 34, is fixed with respect to the housing. As is apparent from FIG. 5, leg 14 may be rotated in one direction with leaf springs or ratchets 102 riding up and over ramp 98. Disc or ratchet member 96 is preferably fabricated from stainless steel. The fingers have spring memory so that they flex as they move over ramp 98. Upon reverse rotation of leg 14, one of the ratchet teeth 102 will engage a vertical end 112 of ramp 98. Since bushing 72 is fixed with respect to pad subassembly 12, reverse rotation of leg 14 and hence axle 52 and leg 16 is prevented. Spring 90, adjacent leg 16, loads the assembly, accommodates manufacturing tolerances and insures that ratchet fingers 102 are in contact with flange 78 and ramp 98 of bushing 72. 
     The foot rest in accordance with the present invention accommodates a wide variety of physical characteristics of potential users. Four mechanical height positions are provided by legs 14, 16. It is presently preferred that the legs be dimensioned and axle bosses 58 positioned so that height positions of 3.1 inches, 3.9 inches, 4.4 inches and 6 inches are provided. The foot print area of the assembly is approximately 16 inches wide by 12.7 inches deep from front to back. The total width of the foot rest is approximately 18.5 inches. 
     Tilt positioning of the upper surface of the pad assembly as provided by the mechanical height positions and the elliptical shape of the foot pad housing. The elliptical shape allows the user to place his or her feet at angles from 0° to 22° at all four mechanical height/tilt positions. A smooth pivot action is provided since the shaft 52 rides within hub portions 76, 82 of bushings 72, 74. Operation is simplified from prior devices. The legs and shaft are permitted to rotate in only one direction. Rotation of one leg rotates both legs. Additional anti-skid characteristics may be provided by the application of a rubberized material to lateral sides 22, 24, 26, 30 of legs 14, 16 as well as of the undersurface of front portion 48 of the foot pad subassembly 12 where the subassembly contacts the floor. Foot pad mat 40 is preferably manufactured from compression molded nitrile (Buna-N). The foot pad housing 34 is preferably manufactured from a structural plastic, such as an injection molded ABS. The legs are manufactured from an injection molded ABS. The axle 52 is fabricated from cold-rolled steel. Bushings 72, 74 are preferably fabricated from injection molded nylon 6/6. Ratchet member 96 and spring washer 90 are stamped from stainless steel. 
     In view of the above description, those of ordinary skill in the art may envision various modifications which would not depart from the inventive concepts disclosed herein. It is expressly intended, therefore, that the above description should be considered as only that of the preferred embodiment. The true spirit and scope of the present invention may be determined by reference to the appended claims.