US543870A - Ernest gustav hoffmann - Google Patents

Description

FMANN. ER.

((No Model.)

',Ptentsd Aug. 6

ilisrrnn Sterns @erster @errent ERNEST GUSTAV HOFFMAN, GF NEW YORK, N. Y., ASSGNOR TO THE STANDARD @ASTER ANB til'El'l COMPANY, Oh SAME PLACE.

caerse..

SPEGIFIGATIQNforming part of Letters Eatent No. 543,870, dated August 6, 1895.

I VApplication filed February 15, 18957. Serial No. 538,487. (No niodel.i

To all whom it may concern:

Be it known that I, ERNEST Gns'rriv Horn MANN, a subject'of the Emperor of Germany, and a resident of the city and county of New York, State of New York, have invented cer-` tain new and useful Improvements in Casters and Caster-Sockets, of which the following is a specification, reference being had to the aecompanying drawings, forming part hereof.

This invention relates vto casters, such as are employed for supporting articlesrofffurniture and for analogous purposes, and relates 'more particularly to sockets adapted to beinserted in the articles'of furniture for receiving and holding such casters and to the bearings for such castersin the sockets oi' articles of furniture.

My invention has for its objects to improve and siinplifythe construction of Stich devices.

One of the difficulties heretofore encountered in the manufacture ,of casteiesockets has been in forming the detaining--spring or other detainingdevicehavingforits object the holding of the caster with a yielding pressure sufficient o prevent the caster from falling out when the articlel is lifted, but permittingthe caster to be inserted in or reinorcd from the socket upon the exertion of-slight force. Various means have been devised for pcie forming this function; but the construction heretofore employed with a detaining spring ltongue stamped inward from the wall of the socket is best adapted for the various forms of casters and sockets and is in all respects the most satisfactory; but it has heretofore been ditlicnlt to obtain the proper clearance between this spring-tongue and the wall of the socket such as vis necessary to insure free action of the spring tongue without weakening the blank 4too much to permit it to be drawn into shape, and the formation of this spring-tongue has required extra operations, which extra operations in ariiclesvsnch as caster-sockets, which are made iu large quantities at the minimum cost,nicans a ecnsiderable and substantial extra expense and is, therefore, highly objectionable.. The detaining-spring of iny-iinproved socket may bc cnt out or formed in the operation ot cutting ont or formingr the blank from a sheet or strip of metal, and in one or more stamping operations, `whereby the blank is stamped orI drawn into a complete socket., the detainingspring may be brought iutoproper position in the wall of the socket and with a proper y clearance of the wall. I prefer to employ two stamping operations for the formation ofi'the complete socket from the blank, and 1n thpje first of these stamping operations the detaining-spring is drawn into the wall of tliie socket, Iand in the second of these operations the detaining spring is bent inward into desired position to engage with and yieldingly hold the pintle of the caster.

` It is highly desirable to employ ball-bearings in casters in such a manner as to substantially do aiiay with'siidi-ugi,r friction between the caster andthe socket er article sup ported by the caster, and ball-bearings have to some extent been heretofore employed for such purpose; but no construction has heretofore been devised wherein, as in the c011- struction embodying iny invention, hereinafter described, the highly desirable feature of a separate socket has been combined with ball-bearings between such caster and the socket or article supported thereby.

According to my invention compiete sockets for casters may be produced by a single cuttingoperation and one or two stamping operations, and a tubular caster-socket with one or more detaining springtongues in thew'all thereof may be made by forming a blank having one or more. projecting tongues, and havi-ngelongated portions entendil gon either side ot' said tongue or tongues, said elongated portions being suitably shaped, so tliat \vl1en folded there will be a sutlicient opening or openings between them for clearance of the spring-tongues, as by inoentations formed in such elongated portions in proximity to the tongue or tongues, and then hsubmittingbr the blank to one or incre stamping' operations, whereby the elongated portions are folded up into tubular form with the tongue or tonguesin the wall thereof. In the construction hereinafter particularly described, two of said elongated portions are formed in lin@ with'each other, and two of said tongues are formed, one on each side of the blank, and the complete socket has a tubnlarportion composed of two substantially seinitubnlar parte joined at their upper ends, with the re taining-springe in the openings between said eeniitubular parte; ont other constructions may be devised within the purview ott' my invention,in whichthetuhularportion. ielongitndinally divided into more than twopartn, and in which but.` one iettiiiilig'-s1i1iiig or a greater number et'A retaining-springeare ern-` ployed,vor in which the retainingeprings are omitted. f

Theaccompanyingdrawings illustrate enr bodiments of my invention.

Figure l is a .face .view'of a blank for a caster-socket having a flange or-supportingplate thereon and adapted for use m an vartielehaving awooden hase or lege. Fig. 2 isn vertical central Section showing the partiallyformed Socket made from ihe blank shown in Fig. l at the termination ofthe tiret nta1nping operation. Fig. is a sideelevation Show: ing the completed socket made from the blank shown in Fig. l. Fig. 4 is -an underneath plan view of thesalne. Figa 5 is a verticall central section of a complete easter and a socket such as is illustrated in Figs. 3 and '4 and a portion ot a leg or base of a wooden article of furniture in which said socket in Secured and said cantor held. Fig. (j is afaee view of a blank for a caster-socket not pro vided with a flange or siu'iporting-plate and adapted for use in au article having al metal base or legs. Fig. 7 is a side elevation ot the completed socket Stamped from the blank shown in Fig. ti. Fier. 8 is a vertical central section of a complete socket. such as is illusl trated in Fig. Tand, a portion of a metal eg or haeo ot' an article of furniture, and shouts in full elerztion a caster held therein.

in making,r my improved castereocltete the tirs-t operation in that ot forming;` the blank, and this may be et'lected by a single cutting f iperaton, although it in, oi' course, evident: that'tthe blank may be formed by any desired menue. when the socket in to -be used iu metal articles and it is not desired to torni :t flange or.supporting-plate thereon, the blank is made up ot' elongated portions ot eem-rally rectangular lorm, and in the c0n ntruction shown, wherein the etnnpleted tulnl lar part iS iliade up ot' two Selni-tnben, two

elontntted portions (L d are provided, and lat orztlly-projecting tongues n d are I'orxned thereon between :iaid elongated portions, and the width of the elongated pol-tionen, in prox imity tothe tongue in Such an to provideV an openinfr -uith proper clearanee for said tongues from the wall of` thecolnpleted inhular portieri ot the Socket, thin heingprovided tor by l't'nmint;F indentatiouo o? at the edgce ot. the blanh oneithcr eide of and in proximity to these tongues, and the parte of the .longitudinal portions beyond the length of said tongues are of full width, no .ne to produce tivo 'substantiallyeoinplete eeniitnhes. "lhie blank for the :toeliet unprovidedwith n. Lianne or eupportiiw plate ienhoivn in Figi. 6'.

llfhen the toeliet to notified .iu'n-ioodeu and that if only one detainingpspringv is desired one ofthe tongues maybe omitted, and

A that where other means than these detaining- Springs are provided for holding;l the easter within the socket, or where it is not desired to yieldingly hold thecasterwithin the socket, these spring-tongnes may loe omitted altogether. If one or both of said spring-temples were omitted, the intflentationel n.2 o? would not usually he as deep as shown, but would exist; to some extent to facilitate the formation of the Socket during the stamping operation.

'lhe blank shown in Fig. G may be formed up into the socket shown in Fig. 7 by a sin gie stamping operation, d tiring which operation the elongated portions rt ou either side of the swing-tongue are folded up .into suhstantially semituhular parte, joined at their upperends to forma continnauee-rinegand the spring-tongues ol are drawn into the walls of the tubular parteoinposed of said semituhular parte, and said spring-tongues extend downward into the openings between said lemi tubular parts and {vith Suitable clearance ot' the walls of said semitnbular parte, so that there will he no interference with the free action ot theoe Sprin; ;-tonguen as detainingr- Springe. I prefer to hendin these spring tongues o. to their final positions, in which they are shown in 'ltig. S, hya Separate operation, which may tnltepl'aee while the not-het in held in the stamping-die or after itv han been removed therefrom. In sockets? fornletalartieles Ipretertohavo the upper end ot` thesoeket completely closed, as shown, hut said closed end does notactas a hearing; to suetain the vertical pressures from the caster, as the cavity or holo in the lee, of the metal article is usually sufficiently deep to leave considerable clearance between the top of the soeketand the end of the cavity, and an there 1s noSustaining-ilange on the socket the pintlc will push the Socket up into the eavity as far as the pintle io allowed to movev hy other bearingsurt'aceo which nus-tain the vertical preesu re, and which will loe hereinafter deaerihed.

In Fig. 8 Z1 represents a portion of the leg of a metal artiele-snch, for instance, as nu iron or brass b edstead-aud b is the cavity or hole formed therein to receive and hold the eoclret. Ae lieferte rt-tated, the blank for n flanged. toeliet in rhown in lilo'. l. The Haugen ot? this .nov'ided for by the fan-shaped enlargements or enlarged ends ai a3, and several points or teeth a4 are formed along the outer edges of these'ends. ln shaping or -orming this blank into a complete socket l prefer to.

socket and of the jdetaining-springs is sub? stantially the same as already described in relation to the socket unprovided with a 1 tlangeorsupporting-plate; but-itis desirable,

in sockets to'he employed on woodenwarticles to have the upper end of the socket completely open,for the reason-that the socketis rigidly held hy itsilange from exceeding a certain de grec of penetration into the article, and therefore anv chi sorshavinvswhich were wedfred lJ e e r-intothe socket would, if the socket had its upper end closed, act to clog and choke the socket, so as to prevent the insertion of the casterpintle. x I therefore cut away the upper end of the socketA during the irst stamping operation, so that the tubular portion is open at both ends at the completion of this operation.

The annularflange at the mouth of the socket is only partially formed during' this iirst operation, a concave recessed, annular portion being formed therein, but with the portion of the flange outside of said recess in flattened condition. In the second stamping operation the shaping lof the liange vis completed by formingan yannular bead thereon and turning npthe outer edge so that the points a4 project upwardly. I 4prefer to bend the detaining-springs d inward into their desired working positions during this second stamping operation. Thus a complete 'flanged socket having a -rounded supporting-plate thereon and having detaining-springs in the walls thereof held in operative position with clearance of said walls, and havinfr an open upper end is formed by three operations,one cutting operation and two stamping operations.

It will be observed that in the tubular portion of the socket the upper end of the socket is a complete tube or continuous ring not seemed ordivided,andthat the spring-tongues extend downward from this complete tubular portion or ring, and that the tubular portion below this 'complete tubular part is seamedor divided longitudinally into two substatitiallysemituhular parts, and that the springvtongues d are located within the openings between these scmituhulaiparts, and that thel'la'nge is'rnedially divided or seemed and is made up ofl two seniian'nnlar parts, each continuous with one of said semitubular parts, and that the liange has a concave annular recesssurrounded by anannnlar head and has points extending-upward around the edgeslof said bead, said points being adapted to penetrate the article of furniture. Itis of course evident that these points may he slightly inclined inward so as to tend to force the .two semi-parts toward each other when the socket is driven in place.

It will he noted that the socket is largely reinforced and held against any lateral pressureor strain both by the walls ot' the cavity or hole c in the leg or base c of the the article of furniture wherein said socket is held and by the penetration of the points of into the lower surface of said leg or base c, and thus any tendency to' spreading ot the socket is effeotually resisted.,

It is desirable that the lower surface of the socket-flange shall he without projecting. points or edges, so asv to slide smoothly over the floor or ground, and l therefore slightly round. the lower edges of .the flange along the radial dividing-lines of v.the flange, as shown in the drawings. This may he readily effected as a part of the stampingoperation hy suitably forming the dies, as lwill loe well underf stood. t

The caster shown in the drawings is provided with' a wheel d fitted to rotate on apin d passing through the arms of a horn-frame e. The pintle-f is rigidly secured to the hornframe, the lower end of the pintlef having a somewhat 'conical shoulder or enlargement fitting against a depressed portion of the hortvfrarne e around'a central perforation, l

and the extreme lower end of the pintlefheing tightly riveted over againstthe lower face of the horn-franie e. This manner of uniting the horn-frame and pintle is simple and effective; but the parts maybe otherwise united or made in one piece. The pintlef has a knob or enlargement at its upper end,

which inno-operation with the detainingsprings a yieldingly holds 'the caster in the socket.l

A ball bearing case g ,is provided, fitted upon the pintle so as to rotate freely thereon,

IOO

EIO

and is longitudinally held thereto, but with sufficient freedom' to transmit all vertical strains to the caster through the halls h, arranged within said hall-hearing case. These balls intervene between the ball-hearing case g and the caster-pintle and frame, and, as shown, bear vertically downward against the horn-frame and laterally inward against the pintle. To restrain the hallhearing case from moving upwardly to sl ch an extent as. to release the balls or become detached from the caster, l form burrsf, raised from the mateg rial of the pintle f and projecting outward just above the upper surface of theloall-hearing case g, and this construction is exceedingly simple and inexpensive and eiliectively holds the ball-bearingcase and bearing-balls to the other parts of the caster, so as to prevent any separation of said parts.

The ball-bearing case g is shaped sofas to t within' the concave-annular recess ot' the socket :when the socket is provided with a angeHa/s shown in Fig. 5, or to lit within a concave depression formed in the bottoni' of bead and a concave annular reeeSS en@ being made up of radially divided parte -Qh continuous with one of the tubular parts, in oombination with a caster having a pintle held in said tubular portion of the socket, e, ball bearing case free to rotate on said pintle and .ftting into the annular recess of the eoeket flange, and bearing balls within said case .and

intervening between said case and the caster pintle and frame, substantially as set forth. xo This specification signed and witnessed this 13th day of February, A. D. 1895.

ERNEST GUSTAV HOFFMANN. In presence of- HENRY D. WILLIAMS, GEO. I-I. SONNEBORN.

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