Chair Lift

Abstract

In combination with a chair having four legs, a chair lift for raising the legs off the floor comprises roller means for supporting the chair when the legs are raised; support means from which the roller means depend into contact with the floor comprising two plate members disposed between opposite pairs of chair legs; means on the support means for pivotably mounting each plate member about an axis between the pairs of adjacent legs for limited pivotal movement between inclined and horizontal positions relative to the floor and a lever arm overlying and contacting one of the plate members and non-rotatable in a vertical plane with respect thereto, the lever arm adapted for pivotal movement in a vertical plane between inclined and horizontal positions relative to the floor and pivotally connected to the other plate member for pivoting the plate members between their inclined and horizontal positions in response to pivotal movement of the lever arm between its inclined and horizontal positions.

Description

The present invention relates to devices for raising the legs of chairs off the floor and, more particularly, to such devices which permit the chain to be rolled with the legs raised off the floor.

Conventional four-leg chairs, such as kitchen or dining room chairs, are not designed to be movable while a person is seated in the chair. Accordingly, when it is desirable to adjust the chair position, e.g., relative to a table, a person must transfer his weight from the chair to his legs, at least for the instant necessary to move the chair. Even when the chair is to be moved by a person other than the one seated in the chair, unless the seated person can support most of his own weight, the chair is extremely difficult to move. This difficulty is further compounded when the chair is located on a carpet or other frictional surface.

While adjusting the position of a chair by sliding or pulling one's self closer to the table is a relatively simple and routine act for most people, elderly and ill or crippled people are able neither to move their own chairs nor to support their own weight. For them such simple and routine every day acts are extremely difficult.

Accordingly, it is the primary object of this invention to facilitate four-leg chair movement by providing a chair lift device which raises the legs of the chair off the floor and supports the chair on rollers.

It is another object of this invention to provide a chair lift which may easily be attached or detached from a chair to permit its temporary or intermittent use.

It is still another object of this invention to provide a chair lift which can be operated by a person other than the person seated in the chair by simply depressing a lever on the front or rear of the chair lift.

It is yet a further object of this invention to provide a chair lift which can be locked in the lifted position and constitute, together with the chair, a small, easy to maneuver wheelchair.

Other object and advantages will become apparent from the following description and appended claims.

Briefly stated, in accordance with the aforesaid objects, the present invention provides a chair lift for raising the legs of a chair off the floor comprising roller means for supporting the chair when the legs are raised off the floor, support means from which the roller means depend into contact with the floor comprising two plate members disposed between opposite pairs of chair legs; means on the support means for pivotally mounting each plate member about an axis between the pairs of adjacent legs for limited pivotal movement between inclined and horizontal positions relative to the floor and a lever arm overlying and contacting one of the plate members and non-rotatable in a vertical plane with respect thereto, the lever arm adapted for pivotal movement in a vertical plane between inclined and horizontal positions relative to the floor and pivotally connected to the other plate member for pivoting the plate members between their inclined and horizontal positions in response to pivotal movement of the lever arm between its inclined and horizontal positions.

The invention will be better understood from the following description taken in conjunction with the accompanying drawings.

FIG. 1 is a perspective view of the chair lift of the present invention in the extended or lift position.

FIG. 2 is a side elevation of the chair lift of the present invention in the rest position attached to the legs of a chair.

FIG. 3 is a side elevation of the chair lift shown in FIG. 2 in the extended or lift position.

FIG. 4 is a plan view of the chair lift of FIG. 1.

FIG. 5 is a sectional view taken substantially along line 5--5 in FIG. 4.

Turning now to the drawings, and particularly to FIG. 1, there is shown generally at 10 the chair lift of the present invention. Lift 10 consists of generally rectangular front plate 12 substantially spanning the space between front legs 100 and 102 of the chair and generally rectangular rear plate 14 substantially spanning the space between rear legs 104 and 106 of the chair. It will be appreciated that the plate members need not necessarily be associated with the front pair and rear pair of legs, but can be associated with any opposite pairs of chair legs. Adjacent the front margin of plate 12 and the rear margin of plate 14 and disposed near the respective sides of each plate are housings 16. Each housing 16 is generally square in cross section and extends inwardly from the side edges of the plates 12, 14 a relatively short distance toward the center of the plates. Slidable and rotatable within a lengthwise bore 18 in each housing are spindles 20a, 20b, 20c and 20d extending outwardly from the housings toward chair legs 100, 102, 104 and 106 respectively. Associated with each spindle is a U-bolt 22, the threaded legs 24 of which pass through horizontally disposed holes 26 in the spindle 20. Preferably, the closed portion of the U-bolts face forwardly (on front plate 12) and rearwardly (on rear plate 14) and the legs of the chair are received within the U-bolts as seen most clearly in FIGS. 2-4. The U-bolts 22 are secured tightly around the chair legs by tightening nuts 28 onto the threaded legs 24 of the bolts. Lift 10 is adjustable to accommodate various chair leg arrangements by relative movement of spindles 20 in housings 16. Thus, spindles 20 may be extended or retracted to accommodate various size chairs. When fully retracted, the nut 28 adjacent housing 16 abuts the housing. Lift 10 is further adjustable by relative sliding movement of housings 16 toward and away from the sides of plates 12, 14. Each housing 16 has associated with it two slots 30 extending a short distance inwardly from the side of the plate adjacent the housing toward the center of the plate. Screws 32, having their head portions abutting the undersides of plates 12, 14 and their shank portions extending through slots 30, are threaded into housings 16 (FIG. 5) to secure the housings in place. Depending from the underside of each of the front and rear plates and preferably adjacent the side edges thereof, are conventional swivel caster assemblies 34 or other suitable roller means, such as conventional wheels, to support the chair when the legs are raised off the floor.

Secured, as by welding or other suitable means, to the underside of front plate 12 and extending perpendicularly rearward therefrom is front abutment member 36 which consists of a generally rectangular bar member having an arcuate upwardly offset portion 38 at one end thereof. The offset portion is disposed rearwardly of plate 12 and oriented with the offset portion 38 opening downwardly. When the top surface of the member 36 is mounted face to face with the underside of plate 12 the convex top 40 of arcuate portion 38 is disposed in substantially the same plane as the upper surface of plate 12. A rear abutment member 42 is similarly secured to the underside of rear plate 14 and extends perpendicularly forwardly therefrom. In construction, rear abutment member 42 is essentially the same as front abutment member 36 and consists of a generally rectangular bar member having an arcuate upwardly offset portion 44 at one end thereof. Rear member 42 is mounted with its upper surface in face to face engagement with the lower surface of rear plate 14 and with the arcuate offset portion 44 extending forwardly of plate 14 and opening downwardly. In this configuration the convex top 46 of arcuate portion 44 is substantially coplanar with the upper surface of plate 14. Abutment members 36 and 42 are preferably disposed about midway between and parallel to the side edges of plates 12, 14 respectively.

A lever arm 48 is disposed in generally perpendicular relation to plates 12, 14. Arm 48 extends rearwardly from plate 12, overlies plates 12 and 14 in generally vertical registry with abutment members 36, 42 and has a portion 50 projecting rearwardly beyond the rear marginal edge of rear plate 14. Arm 48 is attached to front plate 12 and front abutment member 36 for pivotal movement in a horizontal plane only through bolt 52 passing through one of apertures 54 in the arm and a corresponding aperture 56 in front abutment member 36. The bolt is secured in place with nut 58. As can be seen from FIGS. 1 and 4 the arm is forwardly and rearwardly shiftable relative to plates 12, 14 by the provision of a number of apertures 54 for insertion of bolt 52. Arm 48 is not attached to rear plate 14 or to rear abutment member 44. Rather it is loosely connected thereto, to allow relative horizontal and vertical rotational movement through loose fitting U-bolt 60. As can be seen in FIG. 1, the legs of U-bolt 60 depend along the sides of arm 48 and rear abutment member 44 just rearwardly of arcuate offset portion 44 while the web of U-bolt 60 rests on the top surface of arm 48. The legs of U-bolt 60 pass through the openings in conventional U-bolt flange 62 disposed underneath rear abutment member 44 and are secured by nuts 64.

The structural aspects of lift 10 will be more clearly understood from a description of its operation. As can be seen in FIG. 2, which shows lift 10 in its rest position with U-bolts 22 firmly secured around legs 100, 102, 104, 106 of the chair, front plate 12 and arm 48 form a unit which is rigid in the vertical plane and which inclines rearwardly and upwardly. Rear plate 14 is independent of this unit and inclines forwardly and upwardly. In the rest position, arm 48 contacts the tops 40, 46 of abutment members 36, 42 respectively, and, due to the inclination of plate 12, is spaced apart from rear plate 14. Contact between the arm and the rear plate is loosely maintained through U-bolt 60. By virtue of the inclination of plates 12, 14, caster wheel assemblies 34 are inclined inwardly toward the center of the chair and in contact with the floor surface.

To operate lift 10 to its lift position shown in FIG. 3, a vertically downward force is applied to rear portion 50 of arm 48 to rotate the arm into contact with rear plate 14, after which arm 48 is pivoted horizontally about bolt 52 (see FIG. 4) until the arm locks in place beneath a locking means. The locking means is preferably an inverted L-shaped keeper arm 66 (best seen in FIG. 1) having the free end of its vertical leg secured to the top surface of rear plate 14 at a point slightly offset from the lateral mid-point of the plate and the horizontal leg overhanging the mid-point of the plate with the L opening toward arm 48. As the rear portion of arm 48 rotates downwardly toward plate 14, the portions of arm 48 rearward of bolt 52 exert vertically downward forces at abutment points 40 and 46. These vertical forces cause the front plate 12 to rotate counterclockwise about front spindles 20a and 20b to a generally horizontal position and the rear plate to rotate clockwise about rear spindles 20c and 20d to a generally horizontal position. With arm 48 locked under keeper 66, lift 10 assumes the lift or extended position shown in FIG. 3. In this position, the roller means support the chair with the legs raised off the floor surface.

Although the present invention has been described in connection with a four-leg chair and has oriented the lift 10 with plate 12 spanning the front legs and plate 14 spanning the rear legs, it will be appreciated that the invention is equally applicable where the plate members span, respectively, the right side front and rear legs and the left side front and rear legs, i.e., opposite pairs of legs. Likewise, plate 12 can span the rear legs and plate 14 span the front legs, in which case portion 50 of lever arm 48 would extend toward the front of the chair. In this position arm 48 could be operated by a person seated in the chair who has some strength in at least one leg. Moreover, the principle of operation herein described would be equally applicable for various leg configurations and even for chairs having more or less than four legs, or having, e.g., front and rear or side runners in lieu of legs. In the latter instance, of course, it would be necessary to modify the means by which the lift attaches to the chair. Accordingly, all modifications and equivalents may be resorted to which fall within the scope of the invention as claimed.

Claims

What is claimed as new is as follows:

1. A lift device for raising the legs of a chair off the floor comprising:

a. roller means for supporting said chair when the legs are raised off the floor;

b. support means for supporting said roller means from opposite pairs of adjacent legs for limited vertical shifting of said roller means between upper and lower positions relative to said legs, said support means comprising first and second mounting means from which said roller means depend;

c. attaching means for pivotably attaching said mounting means to the legs of the chair, said attaching means including a housing on said mounting means and clamping means having one end journaled in said housing and the other end engaging the legs of the chair; and

d. said support means including an operator adapted for movement between first and second positions and operatively connected to said roller means for shifting the latter between their upper and lower positions in response to movement of said operator between its first and second positions.

2. A device, as claimed in claim 1, wherein said first and second mounting means comprise first and second plate means, each said plate means including a housing at opposite ends thereof, extension means having one end journaled for rotation in said housing and the other end extending outwardly of said plate means into contact with a leg of the chair, said other end including clamping means for engaging said leg.

3. A device, as claimed in claim 2, wherein said extension means is slidable in said housing toward and away from the said leg of said chair.

4. A device, as claimed in claim 3, including slot means in each said plate means extending inwardly toward the center from the sides thereof, and means slidable in said slot means and associated with said housings whereby said housings are adjustable toward and away from the said legs of said chair.

5. A device, as claimed in claim 3, wherein said first plate means is associated with a first adjacent pair of legs and said second plate means is associated with a second and opposite adjacent pair of legs.

6. A device, as claimed in claim 5, wherein said operator comprises a lever arm bearing upon and non-rotatable in a vertical plane with respect to said first plate means, and means pivotally connecting said arm to said second plate means.

7. A device, as claimed in claim 6, wherein said lever arm is pivotable in a vertical plane relative to said second plate means whereby downward movement of said lever arm between its first and second positions causes said first and second plate means to rotate about said extension means and to shift said roller means between their upper and lower positions.

8. A device, as claimed in claim 7, wherein said roller means comprises wheels associated with each of the legs of the chair.

9. A device, as claimed in claim 7, further including means for locking said lever arm in its second position.

10. A lift device for raising the legs of a four-leg chair off the floor comprising:

a. first support means rotatable about a horizontal axis between an adjacent pair of legs and second support means rotatable about a horizontal axis between the opposite pair of adjacent legs, each of said support means including a housing thereon and clamping means having one end journaled in said housing and the other end engaging the legs of the chair whereby said support means are rotatable between first and second positions relative to the floor;

b. roller means depending from said first and second support means for supporting the chair when the legs are raised off the floor;

c. lever means operatively associated with each of said support means and adapted for shifting between first and second positions, whereby said support means rotate between their respective first and second positions in response to shifting of said lever means between its first and second positions.

11. A device, as claimed in claim 10, wherein said first and second support means are rotatable between inclined and horizontal positions relative to said floor in response to shifting of said lever means.

12. A device, as claimed in claim 11, wherein said shifting of said lever means comprises pivotal movement thereof in a substantially vertical plane between an inclined and a horizontal position.

13. In combination with a chair having four legs, a chair lift for raising the legs off the floor, said chair lift comprising:

a. roller means for supporting said chair when the legs are raised off the floor;

b. first and second roller support means, each said means comprising a plate member substantially spanning the space between a pair of adjacent legs of the chair, said roller means depending from said plate member into contact with the floor;

c. means on each said roller support means for pivotally mounting each said plate member to said legs for limited pivotal movement about an axis between said pair of adjacent legs between inclined and horizontal positions relative to the floor; and

d. a lever arm overlying and contacting said first support means and non-rotatable in a vertical plane with respect thereto, said lever arm adapted for pivotal movement in a vertical plane between inclined and horizontal positions relative to the floor, and pivotally connected to said second support means for pivoting said plate members between their inclined and horizontal positions in response to pivotal movement of said lever arm between its inclined and horizontal positions.

14. The combination of claim 13 wherein said pivotal mounting means comprises a housing at opposite ends of each said plate member adjacent the legs of the chair, means slidable in each said housing having one end journaled for rotation in said housing and the other end extending outwardly of said plate member into contact with one of the legs, said other end including clamping means for firmly engaging said legs.

15. The combination of claim 13 further including means for locking said lever arm in its horizontal position.

16. The combination of claim 15 wherein said lever arm overlies said second support means in substantially perpendicular relation thereto.

17. The combination of claim 16 wherein said plate members incline relative to said floor when said lever arm is in its inclined position and said plate members are horizontal relative to said floor when said lever arm is in its horizontal position.