US2499277A - Caster structure - Google Patents

Description

C. R. NALLE CASTER STRUCTURE Feb. 28, 1950 Filed OOC. 18, 1945 Patented Feb. 28, 195() UNITED sTATEs PATENT oEFlcE CASTER STRUCTURE Charles R. Nalle, Philadelphia, Pa.

Application October 18, 1945, Serial No. 623,030

4 Claims.

This invention relates to adjustable caster structures for articles of furniture and the like, for preventing rocking or distortion of such articles, or for correcting distortion thereof, 'as may arise from unevenness of the floor or other surface on which an article of said kind may be standing.

The adjustable caster structures or devices of the prior art, including those procurable on the open market, are normally of a complicated nature involving many parts, which increases the cost of manufacture, and consequently the cost to the ultimate consumer, materially,

The principal object of the present invention is to reduce the number of parts of 4an adjustable caster structure to a minimum, for example, three relatively movable members, and to construct these elements in a manner whereby they may be manufactured and lassembled at a minimum of cost, whereby the devices may be sold to the ultimate consumer at a very low retail price.

In the accompanying drawings Fig. l illustrates the preferred form of the device of the present invention in side elevation, as installed in a table leg, etc. which latter is shown in vertical sectional elevation;

Fig. 2 is -a vertical sectional elevation as taken on the line 2-2, Fig. 1;

Fig. 3 is a sectional plan View as taken on the line 3-3, Fig. 2;

Fig. 4 is a sectional elevation of two of the three relatively movable parts of which the device of the present invention is composed and as shown in Figs. 1 and 2, said two parts being illustrated as being in the course of assembling; and

Fig. 5 shows a wheel type caster which may be emplo-yed with the present invention.

` In the preferred form of the invention as shown in Figs. 1 to 4 inclusive, two of the elements of the device of the present invention are preferably composed of die castings.

The device, as shown in Figs, 1 to 4 inclusive, is composed of a floor-engaging element such as a conventional caster wheel, or a ball or button type glide A, a ferrule or socket B, and a captive nut C.

The hoor-engaging element A includes an ex ternally threaded Stem I, with diametrically opposite side portions thereof attened and disposed parallel to each other, as indicated at 2, 2; and with diametrically opposite side portions 3,3, lying intermediate and alternating with the flat faces 2, y2, being of a segmental or arcuate nature, with square or V-shaped threads formed therein, the root circle 4 of said threads being substan- 2 tially tangent to the fiat faces 2, 2 of said stem.

The ferrule or socket B includes a circular disclike head 5 and an axially extending elongated neck 6 integral with one end thereof, said neck being adapted to be inserted in a circular bore d formed in the lower end of a table or bed leg D etc.

The neck 6 is provided with an axial cavity I of the same cross section as the stem I, with opposite parallel fiat internal side faces 8, 8 adjacent `and in Snuglysliding contact with the flat side faces 2, 2 of the stem I, and with intermediate arcuate internal side faces 9, 9 adjacent and in snugly sliding contact with the arcuate faces 3, 3 of the stem I which constitute the outer surface of the interrupted or mutilated screw threads formed on the stem I.

The head disc 5 is provided on -an upper annular surface I0 thereof, which surrounds the neck 6, with a plurality of circumferentially spaced, axially extending prongs I I, I I, which are adapted to be driven into or otherwise anchored in the lower end of the leg D to prevent rotation of the ferrule B within the leg cavity d, and to prevent accidential withdrawal of the neck 6 from said leg cavity.

The head disc 5 of the socket BI is also provided with a circumferential annular or peripheral edge ange I2 which nts within an internal annular groove I3 formed in the captive nut C.

The under surface I4 of the head disc 5 is flat and smooth and is adapted to bear on a similar smooth iiat bearing surface I5 formed in the captive nut C.

The captive nut C is held against axial movement in one direction relative `to the ferrule B by contact of the annular surface I5 of the nut C with the bearing surface I4 of the ferrule B; and in the opposite direction by lan annular inturned flange or lip I6 formed on the upper end of said nut and overlying the upper annular surface I1 of the circumferential ange I2 of the ferrule head 5.

The captive nut C is axially bored and internally threaded, as indicated at I8, for cooperation with the segmental thread portions 3, 3 on the stem I; whereby, as the nut C' is rotated clockwise or counter-clockwise, the stem I is moved axially to shorten or lengthen the leg D.

As previously noted, the nut C and ferrule B are preferably made of die castings with the annular lip or ange I6 of the nut C originally extending axially in open ended cylindrical form, as shown at y in Fig. 4, from one end of the threaded base portion of the nut, to form a cer.

tral concentric cavity :c in said one end thereof.

The nut C and ferrule B are assembled, as clearly shown in Fig. 4, by inserting the circumferentially flanged head of the ferrule in the cylindrical cavity of the nut C, after which the axially extending ange y of the nut C is swaged radially inward over the top surface l1 of the annular peripheral flange I2 on the head disc 5, to form the inturned flange or lip I6 and thereby forming the annular groove I3 in the captive nut C by which the nut C is retained in rotatable but axially non-slidable rotation to the ferrule B.

The caster structure of iny present invention is applied to an article of furniture or the like by first forming a hole, like the bore d aforesaid, therein to receive the neck 6 of the ferrulev or socket B. The stem l of the ioor-engaging element A is rst removed from the captive nut C, and the neck of the ferrule is inserted in the said hole in the article to be supported until the ends of the prongs ll engage the surface of the article surrounding said hole, whereupon a sharp blow directed against the exposed lower face of the nut C will cause the prongs il to become anchored in the article. The stem l of the iioorengaging element is then reentered into the captive nut C, until the cooperating threads thereof are engaged, whereupon, turning of the nut or hand -wheel C will move the stern axially into the cavity 'i of the head 5 and neck ii, until the hoor-engaging element A is in a desired initial position with respect to the article.

Normally it would be cliflicult toalign the flat sides 2, 2 of the stem l with the iiat sides 8, 8 of the head 5 at the lower end of the socket or ferrule B after the threads of the stem had caught with the threads in the nut C, and to assist in this operation, in the present instance, the free end of the stem I is reduced in diameter at least to the root diameter of the threads and is devoid of threads for a distance greater than the length of the threaded bore of the nut C, as illustrated at 30. i

This plain end 30 functions as a lead in advance of the threaded section 3 of the stem l to pass uninterruptedly through the threaded `bore of the nut C and to enter between the flat faces 8 supra, whereby a person assembling the floor-engaging elementrinitially with the ferrule or socket B may feel his way in, it ybeinggunderstood that the plain end of the stem will enter the open end of the flat sided opening in the ferrule head 5 before the threads on the stem l engage with the threads in the bore of the nut C and thereby will guide the end of the stem into said opening, then by slight circular manipulation between the stem and the nut the at sides of the stem can be readily aligned with the iiat sides of the opening in the head 5, after which the stem may be readily moved in the ferrule by rotation of the nut C.

While the floor-engaging element A isshown as being of the iiat button type of glide, yit will be readily understood that this glide may be replaced on the end of the stein l by any conventional type of roller or wheel such for example as the ball-bearing type as shown diagrammatically in Fig. 5, wherein a pair of ball races l3l and 32 are mounted on a reduced lower lend 33 of the stem therebetween, and wherein this assemblage is held on the lower end of the stem by riveting the lower end of the stem over a washer thereon, as indicated at 35.

The lower race 32 carries a pair of spaced parl with a series of anti-friction balls 34 I claim: 1. A caster structure composed solely of a oorengaging element including an externally threaded axial stem having at least one axial flat extending along the threaded portion thereof, a ferrule including an elongated neck having an axial bore adapted to receive said stem, at least one axial flat extending along said bore adapted to cooperate with the iiat on the stem preventing relative rotation but permitting relative axial movement between the stem and ferrule, a disc-like head rigidly connected to one end of said neck, a captive nut adjacent and axially aligned with said head and having 'an internally threaded bore adapted to cooperate with the threads on said stem for effecting relative axial movement between said stem and said ferrule, and a peripheral iiange on said head operating in a circumferential groove in said nut to allow relative rotation and to prevent relative axial movement between said nut and said ferrule.

2. A caster structure composed solely of a floor-engaging element including an externally threaded stem having a pair of opposite axial flats cut therein, said ilats being tangent to the root diameter of the stem, a ferrule including an' elongated neck having a bore adapted to receive said stein, a pair of opposite axial flats extending along said bore adapted to cooperate with thev flats on the stem and preventing relative rotation but permitting relative axial movement between the stem and ferrul'e, la captive mit rotatably mounted on one end of said ferrule and pro'- vided with a central internally threaded bore for' cooperation with the' threads on said stem for effecting said relative axial movement between said licor-engaging Aelement and said ferrule, a

f disc-like head forming part of said ferrule and rigidly connected to one end 'of said neck, and a series of circumfer'entally spaced prongs surrounding and spaced radially from the axismof said neck and extending in va 'direetion parallel to said axis for securing said feriule against ife-l tation relative to an article of furniture andthe like to which said caster structure is applied.

3. A caster structure composed solely of a' floor engaging element including an externally threaded Aaxial stem having at least 'one axiall flat extending along the threaded portion thereof, a ferrule including an elongated neck having an axial bore adapted to receive said stem, at leastcne axial iiat extending along said bore' adapted to cooperate with the flat on the stern preventing relative rotation by'perinitting relative axial movement between the stein and ferrule, and a captive nut rotatably mounted on one end of said ferrule and provided with a central internally threaded bore for 'cooperation with the threads on said stem for effecting said relative axial movement between said floor-engaging element and said ferrule;

4. A caster structure Vcomposed solely of ay vfloor-engaging element including an externally threaded stem having a pair vof opposite axial iats cut therein, said iiats being tangent to the root diameter of the stem, a, ferrule including an elongated neck having'a bore adapted to receive said stem, a pair of Iopposite axial flats extending along said bore adapted to cooperate with the ats on the stem and preventing relative rotation but permitting relative axial movement between the stem and ferrule, and a captive nut rotatably mounted on one end of said ferrule and provided with a central internally threaded bore for cooperation with the threads on said stem for effecting said relative axial movement between said floor-engaging element and said ferrule.

CHARLES R. NALLE.

REFERENCES CITED le of this patent:

Number Number UNITED STATES PATENTS Name Date Hartmann Dec. 4, 1928 Nalle Sept. 27, 1932 Nalle Sept. 2,y 1941 Nalle Nov. 23, 1943 Nalle Jan. 18, 1944 FOREIGN PATENTS Country Date France Apr. 22, 1920 Certificate of Correction Patent No. 2,499,277 February 28, 1950 CHARLES R. NALLE It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correction es follows:

Column 3, line 12, for the Word rotation read relation; column 4, line 61, for "by permitting read but permitting;

and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the cese in the Patent Oice.

Signed and sealed this 30th day of May, A. D. 1950.

[out] THOMAS F. MURPHY,

Assistant Uommz'saoner of Patents.

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