Furniture glide

A self-adjusting furniture glide includes an upper body piece rotatably mounted to a lower foot piece having an arcuate ramp surface on which a complimentary ramp surface of the body piece rests, and a coil spring mounted between the foot and body pieces to downwardly bias the foot pieces and to apply a torque which opposes mutual rotation of the pieces.

The present invention relates in general to furniture supports, and it 
relates more particularly to a new and improved furniture support which 
automatically adjusts to retard rocking or tilting of an associated piece 
of furniture on an uneven floor. 
BACKGROUND OF THE INVENTION 
Furniture bases which contact the floor at more than three places are 
frequently unstable and tend to rock about the line connecting two of the 
contact points. This instability is particularly annoying with tables, and 
for that reason many different types of adjustable furniture supports have 
been designed and marketed. In some cases the supports were self 
adjustable while in some cases they were manually adjustable. Where the 
table or other piece of furniture was frequently moved on an uneven floor, 
as for example, in a restaurant, the manually adjustable supports were 
unsatisfactory because of the frequent need for adjustment. On the other 
hand, the self-adjusting furniture supports of the prior art were in some 
cases expensive to manufacture, were often fragile and susceptible to 
damage, and in many cases did not function satisfactorily. In Pat. No. 
3,827,663 there is described a self-adjusting furniture glide which is 
easily adjusted by pushing the piece of furniture along the floor. Where 
the surface of the floor resists such sliding movement, such glides are 
not so easily adjusted. 
It would, therefore, be desirable to provide a furniture glide or other 
support which responds either to sliding or to lifting the subsequent 
lowering of the associated piece of furniture to self-adjust in length so 
as to automatically compensate for the uneveness of the floor on which it 
is supported. 
SUMMARY OF THE INVENTION 
Briefly, there is provided in accordance with the present invention a new 
and improved furniture support which comprises upper and lower mutually 
rotatable parts having mutually abutting ramp surfaces. The upper part is 
rotatable relative both to the bottom part and to the furniture and a coil 
spring is connected between the two parts to urge them apart and to apply 
a torque which resists upward movement of the lower part. 
When the weight is removed from the self-adjusting support, the upper part 
is rotated by the spring and the spring simultaneously expands to press 
the lower foot part in a downward direction toward the floor. When the 
piece of furniture is subsequently lowered so as to rest only on its 
associated furniture supports, the lower foot parts of the self-adjusting 
supports will move up until the weight on the respective support is 
balanced by the spring and the friction between the abutting ramp 
surfaces. 
The ramp angle is selected such that the upper and lower parts are not 
jammed or locked together under the weight of the furniture with which the 
supports are used, but rather the upper part rotates to permit the lower 
foot part to move down into engagement with the floor or to move up until 
the weight thereon is balanced. 
An advantage of the furniture support of this invention is that it is 
relatively inexpensive to manufacture, wherefore it becomes economical to 
use such supports on all of the legs of the associated table or other 
piece of furniture.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION 
Referring to FIG. 1, there is shown a table 10 having a base 12, a post or 
pedestal 14, and a table top 16 attached to the top of the post 14. The 
base 12 includes a plurality of symmetrically disposed legs 18 each 
resting on one of an equal number of furniture supports 20. Preferably, 
the supports are all self-adjusting devices of the type described 
hereinafter, but only one of the supports need be self-adjusting to 
prevent rocking of the table on most uneven floors. 
It will be understood that the pedestal table is shown for purposes of 
illustration and that the furniture support of the present invention finds 
use on most any type of table and other pieces of furniture. 
Referring now to FIGS. 2 and 3, the self-adjusting furniture support 20 may 
be seen to include an upper part 22, a lower foot part 24, a coil spring 
26, a screw 28 and a nut 30. The upper end of the screw 28 is threadedly 
received in an internally threaded hole in the bottom of a piece of 
furniture 32 with which the support 20 is used. The foot part 24 is shown 
in FIG. 3 in its maximum extended position, and as will be apparent from 
the following description, with the foot part 24 resting on the floor the 
weight of the furniture piece 32 will cause the upper part 22 to rotate 
against the force of the spring 26 and permit the foot part 24 to retract 
into the upper part 22. 
Considered in greater detail, the lower foot part 24, which is preferably 
molded of plastic has an annular, smooth, planar bottom surface 34 which 
is adapted to rest on a floor or other supporting surface. The part 24 
also includes a centrally disposed, upstanding tubular portion 36 having 
an inturned annular flange 38 at the top, and a second upstanding tubular 
portion 40 having a pair of inclined ramps 42 and 43 on its upper end. The 
ramps each have an angular extent of 180 degrees and are spaced apart by 
vertical walls 45 and 46. As may be seen in FIG. 2, the head of the screw 
28 is larger than the opening through the flange 38 and thus maintains the 
foot part 34 assembled to the remainder of the support. An end cap 39 is 
pressed into the central opening in the foot 24 and its outer end lies 
flush with the bottom surface. 
The upper part 22 is also preferably molded of plastic and includes a 
centrally disposed, depending tubular portion 50 whose internal diameter 
is larger than the maximum external diameter of the shank of the screw 28 
so as to be freely rotatable thereon. The nut 30 is threaded onto the 
screw 28 above the upper part 22 to secure it in place on the screw. The 
part 22 also has an annular boss 54 on the top surface which underlies the 
nut 30 to provide a smooth bearing surface to permit free rotation of the 
upper part 22 on the shank of the screw 28. It may thus be seen that the 
screw is a shaft on which the upper part 22 may rotate as well as being a 
fastening device for attaching the upper and lower parts together and to 
the associated piece of furniture. The nut 30 is suitably locked in place 
on the screw 23 in any suitable manner such as by a cement or by staking 
to prevent spurious movement of the nut on the screw. 
The upper part 22 also includes a depending annular wall 56 having a 
cylindrical inner surface 57 which is larger in diameter than is the 
outside cylindrical surface of the wall portion 40 of the foot part 24 so 
that the foot part may move freely within the upper part as the support 20 
self-adjusts. Between the annular portions 50 and 56, the upper part 22 is 
provided with a pair of downwardly facing inclined ramps 59 and 60 which 
are complimentary to the ramps 42 and 43 on the foot part. The downwardly 
facing inclined ramps 59 and 60 are sufficiently recessed within the upper 
part 22 such that annular portion 56 serves as a skirt for protecting the 
interface between the upper ramps 59 and 60 and lower ramps 42 and 43 
against environmental contamination. The upper and lower ramps are held in 
mutual abutment by the screw 28 and the nut 30 as best shown in FIG. 3. 
The ramps 59 and 60 are spaced apart by means of vertical walls or 
shoulders 62 and 63 which abut with the respective shoulders 45 and 46 to 
limit rotation between the parts 22 and 24. 
The coil spring 26 is coaxially disposed relative to the screw 28 and has 
its upper and lower end portions 66 and 67 offturned. The end portions 66 
and 67 extend into respective blind holes 69 and 70 in the parts 22 and 
24. The end portions 66 and 67 and the holes 69 and 70 are located so that 
when the foot part is in the fully extended position as shown in FIG. 3, 
the spring 26 is slightly compressed and applies a torque between the 
upper and lower parts 22 and 24 which forces the shoulders 62 and 63 into 
abutment with the shoulders 45 and 46. 
OPERATION 
In use, the screw 28 is finger threaded into the threaded opening at the 
bottom of a table or other piece of furniture and an open end wrench is 
then placed on the nut 30 and used to tighten the furniture support 20 in 
place. Additional ones of the supports 20 are then assembled to the piece 
of furniture the same way. At this time, the foot parts 24 will be held in 
abutment with the shoulder surfaces 62, 63. 
When the associated piece of furniture is then positioned with the 
furniture supports 20 resting on the floor, the weight of the furniture 
will exert a downward force on the upper member 22 causing it to rotate 
and thus move downwardly over the lower foot part 24 until the weight is 
counterbalanced by the spring 26. It will be understood that the spring 26 
must be both twisted and compressed for the foot part 24 to be retracted 
into the upper part 22. Moreover, the friction between the upper and lower 
abutting ramp surfaces must also be overcome by the weight on the 
particular support for such movement to occur. 
I have found that ramp surfaces having an inclination of about nine degrees 
provides a particularly smooth operating self-adjusting support for 
tables. An inclination of about eight degrees or less will cause the upper 
and lower parts to be jammed or locked together against rotation when the 
associated piece of furniture rests on the support 20. 
While the present invention has been described in connection with a 
particular embodiment thereof, it will be understood by those skilled in 
the art that many changes and modifications may be made without departing 
from the true spirit and scope of the present invention. Therefore, it is 
intended by the appended claims to cover all such changes and 
modifications which come within the true spirit and scope of this 
invention.