US2137803A - Chair tip and fastener therefor - Google Patents

Description

NGV. 22, 1938. GQ Wl HAMBROQK 2,137,803

CHAIR TIP AND FASTENER THEREFOR Filed May 16, 19.58

nmii-lmv Patented Nov. 22, 1938 UNITED STATES PATENTOFFICE CHAIR T IP AND FASTENER `THEREFOR.

George W. Hambrook, Oak Park, Ill., assigner to l Clarin Mfg. C'o., Chicago. Ill., a corporation of Illinois ApplicationMay 16,

6 Claims.

This invention pertains to chair tips of the kind typically shown in Letters Patent to Grant, No. 1,789,974, dated January 27, 1931, and consisting of a foot in the form of a block of solid rubber or other exible material and a fastener for securing the foot to the lower end of a chair leg. In the structure disclosed in the said patent the tip is used on a metal chair leg which has hollow beads on its longitudinal edges, and the fastener consists of a U-shaped yoke bent to shape from a section of round rod stock, the base and lower portions of the arms of the yoke being embedded in the foot and the projecting portions of the arms being driven into and frictionally engaged with the beads of the chair leg.

An extended manufacturing experience with this type of chair tip by my assignee has disclosed some faults therein, which it is the object of the present invention to remedy. In the first place, the base member of the yoke being of round cross-section, when the lower portion of the foot wore off exposing the base of the yoke, the latter would make ydents and'grooves in the surface of the floor. In the second place, in order to prevent the lower end of the chair leg from cutting down into the rubber foot it was found necessary to insert metal washers on each arm of the yoke between the beads of the leg and the top of the foot, which added to the cost; and in the third place, the embedded portion of the yoke, being of round cross-section and smooth external surface lacked a secure grip on the rubber foot such as to prevent relative movement between the two.

The improved fastener of the present invention has a wide flat imperforate base that willnot dent, score, or otherwise mar the surface of the floor if brought into Contact therewith; the arms are formed with stop shoulders that limit the penetration of the beads of the chair leg into the foot, and thus do away with the metal washers heretofore used; and the yoke being of rectangular cross-section throughout, and preferably made as a metal stamping, has a secure grip on the foot that prevents any looseness of fit or relative movement of the foot and the yoke.

A preferred embodiment of the invention is illustrated in the accompanying drawing, in which Fig. 1 isa perspective view of the novel fastener yoke.

Fig. 2 is a top'plan view of the same.

Fig. 3 is a side elevation of the same.

Fig. 4 is a perspective elevation of the lower portion of a chair leg with the rubber foot attached thereto.

193s,` serial No. 208,156

(c1. '4s-137.1) i I Fig. 5 is a vertical longitudinal section through the leg and foot on line 5-5 of Fig. 8.

Fig. 6 is a Vertical transverse section on line B--6 of Fig. 5; and

Figs. 7 and 8 are horizontal sections on lines 1 -1 and -zrespectively of Fig. 5.

Referring to the drawing and rst describing partsthat areold and disclosed in the aforesaid Grant patent, Ill designates as an entirety a metal leg of a foldable'chair which is made from a strip of suitable sheet metal, the longitudinal edge portions of whichv are rolled`to form parallel tube-like edgeslor beads II. I2 designates the foot, which is preferably a solid block of vulcanized rubber.

The footjis attached to the chair leg by an improved fastener yoke in which the novelty of the present invention mainly resides. This yoke is preferablydie-stamped from a flat strip of suitable metal, such assoft steel, and is then bent to the general Uf-shapeshown in Figs. 1, 3 and 5. Theformof -thedie issuch as to create a pair of arms and a transverse connecting member or base. When the device is bent to nished shape the arms are substantially parallel, and the upper main portions I3 thereof that are driven into the beads I I are narrower than the lower portions I3 thereof and the fiat base I4 that are embedded in the rubber foot I2 prior to vulcanizing the latter. At the mergence of the relatively narrow and wide portions I3 and I3' of the arms are formed shoulders I5 that normally lie slightly below the top surface of the foot I2, as shown in Figs. 5 and 6.

The upper end of one leg portions I3 is bent inwardly as shown at IB, and the distance between the free end of this bend I6 and the upper end of the other leg portions I3 is slightly less than the distance between the walls of the beads engaged by said ends, so that the arms of the fastener yoke are slightly expanded as they are driven into the beads and have a friction bite or grip on the internal walls of the beads at the points a., b, c, and d (Fig. 7), amply sufficient to prevent the foot from dropping off the leg when the latter is raised to take the foot off the floor.

The base member I4 of the yoke has a wide, flat, smooth imperforate bottom surface, so that if or when the rubber foot wears down sufficiently to expose said surface it will not dent, groove or otherwise mar the surface of the floor, but will act as a glider.

The main function of the shoulders I5 is that of a stop to limit the extent to which the lower ends of the beads can cut into the rubber foot.

Obviously, they take the place of. and render unnecessary, the metal washers 5 of the aforesaid Grant patent. And since the upper portion of the rubber foot is molded over said shoulders, the latter aid in locking the foot onto the portion of the yoke embedded therein.

The fact that the fastener yoke is of rectangular cross-section throughout gives it certain advantages over a similar yoke of round cross-section. It presents greater resistance to any tendency of the foot to slip or turn locally on the base of the yoke when the foot may be dragged sidewise over the floor; due also to the substantial width of the base member I4 the latter strongly resists any tendency of the foot to cant or tilt sidewise relatively to the chair leg; and the rectangular cross-section of the arms creates comparatively sharp point contacts of the arms on the walls of the beads that strongly oppose any relative sliding movement.

Detail variations from the specic form of the improvement shown in the drawing may be resorted to within the scope of the appended claims.

I claim:

1. A chair tip of the class described, comprising a foot, and a fastener for securing the same to the lower end of a chair leg having hollow beads on its longitudinal edges, said fastener comprising a U-shaped metal member having arms adapted to fit frictionally in said beads and a flat bottomed base of greater width than the bead engaging portions of said arms, said base and the lower portion of said arms being embedded in said foot.

comprising a U-shaped metal member having arms adapted to iit frictionally in'said beads and a nat bottomed base, said base and the lower portions oi" said arms being of greater width than the portions of said arms engaged with said beads and being embedded in said foot.

3. A chair tip of the class described, comprising a foot, and a fastener for securing the same to the lower end of a chair leg having hollow beads on its longitudinal edges, said fastener comprising a U-shaped metal stamping of rectangular cross-section throughout having relatively narrow arms adapted to fit frictionally in said beads and a relatively wide at base, said base and the lower portions of said arms being embedded in said foot.

4. A chair tip of the class described, comprising a foot, and a fastener for securing the same to the lower end of a chair leg having hollow beads on its longitudinal edges, said fastener comprising a U-shaped metal stamping of rectangular cross-section throughout having relatively narrow arms and a relatively wide at base, said arms formed with stop shoulders limiting the penetration of said beads into saidr foot, and said base, said shoulders, and the portions of said arms therebetween being embedded in said foot.

5. As a new article of manufacture, a one-piece fastener for securing a foot to the lower end of a chair leg, comprising a U-shaped metal stamping of rectangular cross-section throughout having relatively narrow arms and a relatively wide flat base integrally connecting the lower ends of said arms.

6. As a new article of manfcature, a one-piece fastener for securing a foot to the lower end of a chair leg, comprising a U-snaped metal stamping of rectangular cross-section throughout having arms formed with relatively narrow upper portions, widened lower portions, and stop shoulders at the junction of said upper and lower portions, and a flat base integrally connecting said lower portions and of the same width as the latter.

GEORGE W. HAMBROOK.

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