US1769245A - Insulating link for pull chains - Google Patents

Description

July 1, 1930.

W. C. TREGONING lNSULATING LINK FOR PULL CHAINS Filed March 3, 1927 l I INfENTOR. wiwl ATTORNEY.

Patented July 1, 1930 entree s'rares PATENT orrica WILLIAM C. TREGONING, OF MILWAUKEE, WISCONSIN, ASSIGNOR, BY MESNE AS- SIGNMENTS, T0 CUTLER-HAMMER, INCL, TION OF DELAWARE INSULATING LINK Application filed March 3,

This invention relates to improvements in insulating links for switch pull chains.

An object of the invention is to provide an insulating link of the above character which is of improved and simplified constrpction, embodying but one piece of materia Another object is to provide for engagement and retention of the metallic links of the chain by the insulating link itself, whereby the necessity for the usual metallic attachments for the latter is obviated.

Another object is to provide insulating links of similar character which are respectively adaptable for either ermanent or manual attachment to a pull c liLlIl.

Another object is to provide an insulating link which may be readily and economically manufactured.

Other objects and advantages of the invention will hereinafter appear.

The accompanying drawing illustrates certain embodiments of my invention which will now be described, it being understood that the invention susceptible of embodiment in other forms without departing from the spirit and scope of the appended claims. In the drawing, Figures 1 and 2 are on larged views in front elevation and longitudinal section, respectively, of one form of insulating link constructed in accordance with my invention, and showin the same applied to a well knowntype of ead chain. Figs. 3 and 4 are front elevational and longitudinal sectional views, respectively, of a modified form of the device illustrated in Fi s. 1 and 2.

igs. 5 and 6 are front elevational and longitudinal sectional views of another form of insulating link constructed in accordance with my invention, and

Figs. 7 and 8 are front elevational and longitudinal sectional views, respectively, of a modified form of the device illustrated in Figs. 5 and 6.

Referring to the drawing, wherein like parts have been given like characters of reference, the numeral 10 designates a tubular member formed of tough and relatively stifl insulating material which is capable of OLE MILWAUKEE, WISCONSIN, A CORPORA- FOR PULL CHAINS 1927. Serial No. 172,547.

being deformed or bent under pressure and of retaining therein such deformations. Thus, as shown in Figs 1 and 2 the tubular member 10 has an inside diameter sufficiently large to permit insertion into its opposite ends of one or more beads or balls 11 of a pull chain. After insertion of the respective terminal or end beads 11, as shown in dotted lines in Fig. 1, the wall of member 10 is indented or pressed inwardly as shown at 12 to provide internal shoulders or shutments 12", which prevent withdrawal of said beads 11 from the insulating member or link 10. While I have shown such abutments as formed by two circumferentially spaced indentations in the wall of member 10 at each end thereof, it is obvious that the number of indentations may be varied; whereas if desired such retaining means may take the form of a complete annular inden tation adjacent to or at the respective ends of member 10.

Thus as shown in Figs. 5 and 6 the terminal beads 11 of the two portions of the pull chain to be insulated from each other are inserted into the respective ends of tubular member 10, whereupon the ends of the latter are spun or pressed inwardly to provide annular retaining shoulders 13.

As will be apparent the insulating links shown in Figs. 1, 2, 5 and 6 are especially adapted for application to a pull chain dur ing manufacture or assembly of the latter. On the other hand, the insulating link illustrated in Figs. 3 and 4 is particularly adapted for application to a pull chain after complete assembly of the latter; that is to say, as an attachment to be applied by the user. The tubular member 10 in Figs. 3 and 4 is in many respects like that shown in Figs. 1 and 2, being provided with the indentations 12 forming shoulders or abutinents 12 for retaining the beads 11 within the ends thereof. However, in order to provide for manual insertion of the terminal beads 11 within the respective ends of tubular member 10 the latter is slit longitudinally, as indicated at 14', whereby pressure manually exerted upon said terminal beads 11 will cause expansion of member 10 to a degree suiiicient to permit passage of said beads over and into interlocking engagement with the internal shoulders or abutments 1Q. \Vhile I have shown a single slit ll extending throughout the length of member 10, it will be apparent that the latter may alter natively be provided with one or more relatively s .orter slits extending inwardly from each end thereof for the purpose aforementioned. l'loreover. in order to prevent accidental insertion of such a number of beads within the respective ends of the tubular member 10 to result in too close proxim ity of the respective chain ends, I preferably provide a pair of lon itudinally spaced indentations forming abntments or shoulders as indicated at 15.

The insulating link shown in Figs. 7 and 8 is likewise apt-ed for manual attachment to the en' 'r of separated portions of a pull chain. This device is in general like that shown in Figs. 5 and 6, in that the respective ends ot the tubular member 10 are spun or pressed inwardly to provide the annular retaining shoulders 13. Moreover. the member 10 slit or slotted longitudinally thereof as indicated at 15, and as described in connection with Figs. 3 and 4.. The slit 1? is provided with an intermediate enlargement 16. oi a size sui'licient to permit insertion of the respective terminal beads 11 whereby the latter may be moved longitudinally and internally of the member 10 to its opposite ends.

The insulating material of which the tubular members 10 are formed may comprise bakelite or any other insulating substance having the characteristics aforementioned, whereas the substance employed may preferably include a fibrous filler to increase the toughness and resiliency thereof.

In the foregoing manner I have provided a pull chain insulating link which is neat and attractive in appearance, and which may be readily and cheaply manufactured from a single piece of tubular insulating stock.

\Vhat I claim as new and desire to secure by Letters Patent is:

1. An insulator for head chains comprising a tubular insulating member, said mem her being slit longitudinally to permit expansion ot the walls thereof, integral internal projections adjacent to the respective ends of said member, said projections having surfaces converging toward each other inwardly of said ends to facilitate passage of chain beads therebeyond, and said pro jections also having transverse shoulders to resist removal of the chain beads from said member.

2. An insulator for bead chains comprising a tubular insulating member, said mem her being slit longitudinally to permit expansion of the walls thereof, integral intera us nal projections adjacent to the respective ends of said member, said projections being arranged to provide a gradually restricted passage inwardly of said respective ends to necessitate forcible endwise insertion of the chain beads thereinto said projections also having transverse shoulders to resist removal of the chain beads from said member, and internal abutments located intermediate the ends of said member, said abutments being formed by depressing the walls of said memher and being adapted to limit the number oi beads insertable within the respective ends of said member.

In witness whereof, I have hereunto subscribed my name.

IVILLIAM C. TREGONING.

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