US2975468A - Self-stabilizing foot for retractable castered tables - Google Patents

Description

March 21, 1961 R, MOCLELLAN SELF-STABILIZING FOOT FOR RETRACTABLE CASTERED TABLES Filed Nov. 2, 1956 XNVENTOR: .FAL PHZ".M:5L2L

/ TTORNEY United States Patent SELF-STABILIZING FOOT FOR RETRACTABLE CASTERED TABLES Ralph E. McClellan, Toledo, Ohio, assignor to The Meilink Steel Safe Company, Toledo, Ohio, a corporation of Ohio Filed Nov. 2, 1956, Ser. No. 620,085 7 Claims. (CI. 16-34) This invention relates to an improvement in a table with retractable casters. More particularly, it deals with such a table in which automatic leveling means are located at each caster or at the end of each leg of the table to support the table when the casters are retracted. The table of this invention finds use for example, as a typewriter table or stand which will rest level and steady on an uneven floor when the table is being used, and may be readily raised on to its casters and rolled out of the way when not in use.

This invention is an improvement of the construction of the retractable caster table described in McClellan copending application Serial No. 477,210, filed December 23, 1954, for a Table With Retractable Casters, now United States Patent No. 2,788,219, issued on April 9, 1957.

It is an object of this invention to produce a simple, durable, eflicient, effective automatic stabilizing means for the feet of a table having retractable casters.

Another object is to produce means for mounting such retractable casters on such a table, which mountings are vertically adjustable on the legs of the table.

Another object is to produce such a table which is level, steady, lightweight and has relatively large, adjustable automatic leveling feet at the end of its legs for increasing the stability of the table when it is in its stable or rest position with the casters retracted, and which feet distribute the load placed on them over relatively large surface areas of contact.

Another object is to produce a foot for a leg and/or table which surrounds a retractable caster and which automatically engages the entire surface of its floor-engaging base with the floor, regardless of the angle at which the leg or support for the caster is with respect to that floor, whereby the load placed on the foot is distributed over a relatively large surface and is stable in engagement with the floor to prevent movement of the table, once the weight of the table is placed on that foot.

Generally speaking, the table of this invention comprises a flat top with a plurality of legs having automatic floor engaging feet means at the ends of each leg and retractable casters at the lower end of each leg. Special means may be provided for extending and retracting said casters, such as a lever mounted under the top of the table for simultaneously extending and retracting all of the casters. The automatic stabilizing means may comprise one or more resilient means, such as gaskets, mounted at and around the lower end of each of the legs or caster supporting means, and a foot anchored to such resilient means, such as a bell-shaped cover having an aperture in its top to fit over the end of the table leg and extend downwardly over each caster, so that the foot or base of the bell-shaped cover can support the leg when said caster is retracted up into the bell, cover or foot.

Thus, when the floor in which the table or legs to be used is uneven, the foot or bell-shaped cover will tilt by deon the floor, which increases the frictional engagement with the floor and stability of the table by distributing the load of the table or weight on the leg thereof over as large an area of contact as possible.

The assembly or mounting for the resilient means or gaskets between the end of the table legs and the bellshaped feet may include flanged sleeves which hold the gasket and bell cover together and which also may be vertically adjustable, such as by screw threads, along the lower ends of the table legs outside of the supports for the retractable casters. The aperture at the top of the bell which surrounds the end of the table leg, is large enough to be spaced from the leg, so as to permit freedom of movement by deformation of the resilient means or gasket which connects it with the leg.

The above mentioned and other features and objects of this invention and the manner of attaining them will become more apparent and the invention itself will be best understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawing, wherein:

Fig. l is a side elevation of a typewriter type table or stand having casters retractable into bell-shaped feet provided with one embodiment of the automatic stabilizing means of this invention;

Fig. 2 is an enlarged vertical section taken through one of the bell-shaped feet of the table in Fig. 1, showing the retractable caster in its retracted position inside the bellshaped foot, and in dotted lines its extended position, and the tiltability of the bell-shaped foot to completely engage the surface of an uneven or tilted floor;

Fig. 3 is a vertical section of just the automatic stabilizing mounting shown in Fig. 2 showing in dotted lines how that embodiment of the invention may be assembled by bending over end flanges on the sleeve to hold the gaskets in position and to clamp between them the upper edge of the aperture in the bell-shaped foot;

Fig. 4 is a top plan view of the completed assembly shown in Fig. 3;

Fig. 5 is a partial plan view similar to Fig. 3 of another embodiment of the means for assembling the stabilizing means of the invention, in which a plurality of bent tongues hold the gaskets together in their bell-shaped foot clamping position; and

Fig. 6 is a partial vertical section similar to Fig. 3 of still another embodiment of the means for assembling the stabilizing means of this invention, in which a ring nut on an externally threaded sleeve holds the gaskets and the bell-shaped foot clamped together.

the legs of the U-shaped members form two of the legs 11 and 12 on each side of the table. The connecting portion 15 of the U-shaped leg members may be fastened to the table top 10 such as by bolt means 17; Mounted below the top' of the table between the legs may be a plate or tray 29 upon which are pivotally mounted a manual lever arm 21 and cam means for automatically and simultaneously extending and retracting the flexible cables 22 extending through each of the hollow legs 11 and 12 for operating the retractable caster wheels 24. The details of the means for operating the retractable casters may be seen in said above mentioned co-pending application, and since they are not a part of the present invention they will not be further described herein in that any means for retracting and extending the casters under the bell-shaped feet of this invention may be provided without departing from the scope of this invention. j

The mounting of the specific retractable casters shown in Fig. 2, is such that the flexible cord 22 may pass freely through the hollow center of a caster supporting swivel pin or stem 3% mounted in a sleeve 31 which may be wedged into the open end of the hollow leg 11, until its outwardly extending bevel 32 contacts the end of the leg. The hollow swivel stem 39 is connected to a brackct member 33 upon which are mounted pivots 34 and 35 with a pivoted lever 36 mounted on the pivot 35, one end of which is connected through a universal type joint 37 to the'end 38 of the flexible operating cable 22, and the other end of which lever 36 is pivoted to one end of a pair of links 39 which supports the axle 40 of the caster wheel 24. This axle 40 is also connected by another pair of links 41 to the other pivot 34 on the bracket member 33. Thus, when an upward pull is exerted on cable 22, the levers 36 tilt to extend the casters 40 to below the lower edges 45 of the bell-shaped feet 25 and the legs of the table are then supported by the wheels 24 of the casters, so that the table may be freely moved about the room. But when the tension in the cord 22 is reduced, then the weight of the table causes the casters 24 to retract into the position shown in Figs. 1 and 2 inside of the feet 25, and the table is then stably supported by the edges 45 of said feet 25. The extended position i; a 2caster wheel 24 is shown by a dashed circle 46 in Referring now to the self-leveling bell-shaped feet 25 and their mounting on the ends of the legs of the table 19, an aperture 50 is provided at the upper end of the bell-shaped foot or housing 25, which is of larger diameter than the outside diameter of the end of the leg 11, and even larger than the outside of the metal sleeve 51 which is employed for anchoring the foot housing 25 to the end of the leg 11. The looseness and space between the edge of the aperture 50 and the inner face of the sleeve 51 as shown in Figs. 2, 3 and 6 and permits slight angular movement of the upper end of the bell-shaped housing 25 with respect to the leg 11 to compensate for any non-perpendicular angularity of the leg or unevenness in the floor 26 between the diiferent legs of the table as shown for the floor 26 in Fig. l and which is accentuated by the dotted floor line 27 shown in Fig. 2.

The sleeve 51 may be rigidly anchored to the end of the table leg 11 or 12, or it may be vertically adjustable thereon, such as by threads 52 provided on the outside of the end of the leg 11 which coact with the internal threads 53 mounted on and inwardly extending on the restricted portion 54 of the sleeve 51. Between the ends of the sleeve 51, there may be provided a pair of resilient gaskets 55 and 56, which, in the embodiment shown in Figs. 2, 3 and 4, are clamped between the flanged ends 57 and 58 of the sleeve bent over from their straight positions shown by the dotted lines 55 and 6% in Pig. 3. Between the inside edges of the flanges 57 and 5S and the resilient gasket means 55, there may be provided metal washers or rings 61 and 62 to protect the resilient or rubber rings or gaskets 55 and 56 and to provide a larger clamping surface against gaskets which in turn clamp or hold the opposite sides of the aperture 59' in the top of the bell-shaped foot 25. Thus, the bent over flanges securely but resiliently hold the edges of the 4- members 55 and 56 in clamped position around the edges of the aperture 50 of the foot 25.

Still further, another type [of sleeve 81 shown in Fig. 6 may be employed having an internal threaded section 83, a bent-over bottom flange 88, similar to bent-over flange 58, and an externallythreaded section 84 upon which a ring nut 85 may be threaded to clamp the washer 61 against the resilient gaskets 55 and 56 for clamping the edges of aperture 50= of the foot 25. The bottom flange 88 of the sleeve 81 may be bent from its dotted line position 90, similarto that of 60 shown in Fig. 3.

Although the sleeves 51, 71 and 81 are only partially internally. threaded, they may be entirely threaded and not require the offset sections and space 91 (Fig. 2) shown between their upper portions and the end of the leg 11. The advantage of only having them partially threaded is that there is provided a longer vertical adjustment of the sleeves on the same length of threads 52 on the legs. This threaded vertical adjustment feature of the sleeves 51, 71 and 81 enables each of the legs to be further adjusted to exactly the same length to compensate for any possible out of vertical angularity of the legs 11 and 12 themselves.

Instead of a pair of gaskets 55 and 56 as shown, the resilient means may comprise a single resilient ring with a central outer groove into which the edge 50 of the bell-shaped member 25 would fit.

If desired, the bell-shaped feet may be replaced by three or more finger type legs which are held in .a resilient gasket and extend outwardly and downwardly from the gasket and around the retractable casters. Also, the operating means 22 for the caster may be through a hole in the side of the foot housing 25 instead of through the center of the leg 11 or 12, without departing from'the scope of the present invention.

While there is described above the principles of this invention in connection with specific apparatus, it is to be clearly understood that this description is made only by way of example and not as a limitation to the scope of this invention.

What is claimed is:

l. A table comprising a plurality of legs, bell shaped feet at the end of each leg spacing the end of said legs from the floor upon which the table rests, each foot having a lower rim floor engaging portion and an upper aperture through which the lower end of said leg extends, and means for attaching said foot around said aperture to said adjacent portion of saidleg, said foot attaching means comprising: a sleeve in said aperture connected to said leg, the peripheral edge of'said aperture being sufficiently larger than the outside of the adjacent portion of said sleeve to permit free angular and longitudinal movement of said foot with respect to the longitudinal axis of said leg whereby said foot may substantially completely contact the plane of the floor even though said axis of said leg is not perpendicular to the plane of the floor under said foot, means on at least one leg of said table for adjusting the connection of said sleeve axially of said leg, annular resilient means around said sleeve and overlapping opposite sides of said peripheral edge of said aperture, ring means on said sleeve covering the opposite ends of the overlapping portions of said resilient means, and flange means on the opposite ends of said sleeve for compressingly engaging said rings against said resilient means to clamp said opposite sides of said peripheral edge of said aperture between said overlapping portions of said resilient means.

2. A table according to claim 1 wherein said resilient means comprises a pair of annular gaskets one mounted on each side of said opposite sides of said peripheral edge of said aperture.

3. A table according to claim 1 wherein one of said flange means comprises a plurality of tongues on said sleeve.

4. A-table according to claim 1 wherein one of said flange means on said sleeve comprises a ring nut threaded on said sleeve for adjusting the compression of said resilient means.

5. A table comprising a plurality of legs, retractable casters at the lower ends of each leg, a swivel for said casters rigidly mounted on the end of each leg, lever means in said caster for extending and retracting said caster relative to said swivel, means extending through the center of said swivel for operating said lever means, bell shaped feet at the end of each leg covering said retractable casters and spacing the ends of the legs from the floor upon which said table rests when said casters are retracted, each foot having a lower rim floor engaging portion and an upper aperture through which the outside of the lower end of each leg extends, and means for attaching said foot around said aperture to said adjacent portion of said leg, said foot attaching means comprising: a sleeve in said aperture connected to said outside of said leg, the peripheral edge of said aperture being sufficiently larger than the outside of the adjacent portion of said leg to permit the free angular and longitudinal movement of said foot with respect to said longitudinal axis of said leg whereby said foot may substantially completely contact the plane of the floor even though said axis of said leg is not perpendicular to the plane of the floor under said foot, means on at least one leg for adjusting the connection of said sleeve axially of said leg, annular resilient means around said sleeve on both sides of said edge of said aperture and overlapping opposite sides of said edge of said aperture, and means on said sleeve for compressing said resilient means to clamp said overlapping portions of said resilient means against said opposite sides of said peripheral edge of said aperture to resiliently attach said foot to said sleeve.

6. A table according to claim 5 including means for simultaneously extending and retracting all of said retractable casters on each leg.

7. A table comprising a plurality of legs, retractable casters at the lower end of each leg, a swivel for said casters rigidly'mounted in the end of each leg, lever means in each said caster for extending and retracting said caster relative to said swivel, means extending through the center of said swivel and said legs for operating said lever means of all of said casters simultaneously, bell shaped feet at the end of each leg covering said retractable casters and spacing the ends of said legs from the floor upon which said table rests when said casters are retracted, each foot having a lower rim floor engaging portion and an upper aperture through which the lower outside end of each leg extends, and means for attaching said foot around said aperture to said adjacent outside portion of said leg, said foot attaching means comprisng: a sleeve in said aperture connected to said leg, the peripheral edge of said aperture being sufiieiently larger than the outside of the adjacent portion of said sleeve to permit only free angular and longitudinal movement of said foot with respect to said longitudinal axis of said leg whereby said foot may substantailly completely contact the plane of the floor even though the axis of the leg is not perpendicular to the plane of the floor under said foot and is prevented from lateral movement relative to said leg, threaded means on at least one leg for adjusting the connection of said sleeve axially to said leg, annular resilient means around said sleeve at least partially in contact with said sleeve and overlapping opposite sides of said edge of said aperture, ring means on said sleeve covering the opposite overlapping portions of said resilient means, and flange means on the opposite ends of said sleeve compressingly engaging said rings against said resilient means to clamp said opposite sides of said peripheral edge of said aper ture between said overlapping portions of said resilient means.

References Cited in the tile of this patent UNITED STATES PATENTS 1,863,370 Geyer June 14, 1932 1,952,115 Borst Mar. 27, 1934 2,597,878 Lee May 27, 1952 2,642,252 Pietz June 16, 1953 2,655,387 Cramer Oct. 13, 1953 2,766,163 Schwartz Oct. 9, 1956 2,827,281 Cooney Mar. 18, 1958

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