US2022785A

US2022785A - Electric plug

Info

Publication number: US2022785A
Application number: US658182A
Authority: US
Inventors: Michael A Rollman
Original assignee: Individual
Current assignee: Individual
Priority date: 1933-02-23
Filing date: 1933-02-23
Publication date: 1935-12-03
Anticipated expiration: 1952-12-03

Description

Patented Dec. 3, 1935 UNrreo stares rA'rENr ori-*ie M2535 ELEGTBQ@ IDLG:

d., li'nll'man, Morini, li'oy, Pa. Application February 23, M533, Serial. No. 658,132

The object or" this invention is to provide the plug with a handle which may be used for pull'- ing it out of and putting it into the socket, to thus relieve the conductor proper of strain, this handle being laterally exible so as to protect the corded conductor from injury by frequent sharp bending at the point of connection with the usual plug proper or cap as more fully hereinafter set forth.

My present invention has particular reference to improvements on the electric plug covered by my former Patent No. 1,810,439, dated June 16, 1931. In the drawing:-

Fig. 1 is a side elevation of my device complete.

Flgfz is alongitudinal sectional view of the device.

Fig. 3 is a detail View of the thimble or ferrule; and

Fig. 4 isa View partly in side `elevation and partly in longitudinal section, showing my device applied to the plug at the appliance-end of the cord.

Referring to Figs. 1, 2 and 3 of the drawing annexed by reference characters, 5 designates the body or cap of the plug which carries in the usual. manner the two terminals 6 adapted to enter the usual slots in the usual wall socket. The cap 5 is provided with a` central passage through which the corded conductor t passes, the two wire conductors enclosed therein being respectively connected to the usual winding screws in the cap.

The cap 5 is moulded, as usual, out of some in-n sulating material, and imbedded in the outer face of the cap in the moulding operation is a. collar IUof metal or some hard insulating material. This collar is anchored rigidly in the' cap, and in Order to insure against rotation of the cap the collar is provided' with an annular milled bead Il at its buried end. This collar is interiorly threaded to receive the screw ,thread-like cord armor I2 of the usual construction. This armor I 2 is screwed into the collar I0 until its inner end is approximately flush with the inner end of 'the collar I 0, and it is then rigidly anchored to the collar bymeans of a ferrule I3 which is inserted into'the end of the tubular armor and is expanded to rigidly clamp the inner wall'thereof. 'I'he body of the ferrule is slightly tapered, as shown in Fig. 3, to facili'- tate it being inserted into the tubular armor and then it is expanded by a suitable tool torigidlyv clamp the armor against the inner wall of the collar III. The outer endof the ferrule I3 isy provided with an outwardly .extending flange I4 (Ci. 17d-322) winch when the ferrule is expanded, is clamped over and against the raw inner end oi the tubular armor i2, the connection between'this ange itl and body of the ferrule being rounded so as to eliminate an annular cuttingv edge at this g point, which cutting edgewould be undesirable in that it would be liable to cut or rupture the fabric covering of the cord In this way the flexible armor I2 is rigidly anchored to the cap 5 in such a manner that it can neither turn nor y@ pullout and also so that no,rough edges will be left that would be likely to fray or cut the covering of the cable'. In assembling, the parts iii, i2 and it are first properly assembled and then the inner end of the collar is moulded or cast 'is permanently into body cap 5. f

Attached to the outer end of the flexible armor I2 is a pull-knob I5 in the form of a collar which surrounds the outer end of the armor and is attached thereto in the same manner that the 20 armor is attached to the collar Ill i. e., by means of a thimble I6 inserted'into the outer end oi the armor tube and expanded in a manner similar to the inner end of the thimble it. The outer end of this thimble I6 is flanged outwardly 25 at Il and this flange is clamped down over the raw edge of the armor tube and is countersunl:l into an annular recess in the collar-knob I5. 'Ihe knob I5 is screwed onto the end of the armor tube in the same manner as the collar I0 is screwed 30 to the tube.

Where the handle is to be applied to the other, appliance-end of the cord, this is done in the manner shown in Fig. 4. I use the usual plug casing I8 which is divided longitudinally as usual 35 and clamped together by screws IB, this casing containing the usual binding screws for' connection with'the two wires of the cable. Instead, however, of casting or moulding the inner end of the collar-Illin ythe `bodyiI Iclamp the same 40 thereinsuciently-rigidlyto avoid rotation in the casing This casing I8 is` as stated, usually made in two half` sections so that it is an easy matter 'to'clampithe-inner end of the collar IIB between the halves'of the casingvby simply tight- 45 ening the `screws I 9. f

Itvwill be understood thata feature of impor- Y tance lies in the idea offscrewing the end of the spiral flexible armor tube into a rigid collar-like member, such as the collar I0 or the pull-knob 50 I5, and thenfrigidlyl anchoring it therein byA an inserted ferrulewhich is expanded against the y inner wall-ofthe armor tube to thus clamp the armor `tube against `thecollarlike member, it being important* that the collar-like member 55 shall have sumeient strength to permit the ferrule to be expanded without cracking or rupturing the collar-like member.

In accordance with the provisions of the patent statutes, I have herein described the principle of operation of my invention, together with the apparatus which I now consider to reprent the best embodiments thereof, but I desire to have it understood that the apparatus disclosed is only illustrative and that the invention can be carried out by other means.

I claim:

1. In a device of the class set forth, a. body, an

one end embraced non-rottively'by said body, a. flexible armor tube having an external thread and having one of its ends screwed into the threaded interior of said collar and extending to the inner end of said collar, and a. metal ferrule in the inner end of said ilexible armor, this ferrule being deformed outwardly so as to rigidly and permanently clamp the inner end of said ilexlble'armoragainsttheintlorotnideoilcr totherebyrlgidlyfastentheendofthelnmr tubetothecoiiar. Y

2.Thestructurerecitedinclaim1,theinner annularedge of said ferrule being curved oui:- wsrdlytonotonlycovertherawinneredgeof 'thearmortubebutalsotopmvideanannuhr rounded edge which. will avoid cutting the mm1 electric fabric-covered cord.

3.Inadeviceoftheclasssetiorth.arigid `(screwed into the threaded e of said body, unyielding collar threaded internally and having andafernllettedintotheendofsaidarmor' tuhethatlieswlthinthebodyand deformedperu womens. noLunN.