US2553681A - Two-part strain relief clamp - Google Patents

Description

y 1951 J. SCHMIER 2,553,681

Two PART STRAIN RELIEF CLAMP Filed Apiil 30, 1949 IN V EN TOR.

Jacob Schmier.

g AZ ORNEX Patented May 22, 1951 Jacob SchmienAllentown, Pan-assigl mrto K011211161 Mfg, .00., Inc., Emmaus, Pa.,,. a...corporation.of;

Pennsylvania ApplicationApril. 30, 1949; .Serial No: 902730 f:

2 Claims:

My invention-.relatesto electricconnectorsand; includes thetype of connectorwhich .carriesea... socket, as well-asthe :typewhich ,carrieswprongss for making an electrical contact to an electrical receptacle or. outletr.

It is an objet of my invention to provide an electrical connector with'asclampiytc prevent any strainupon the. ,cord or cable/carrying the conductors from being transmitted(to theelectrical.

contacts to which the conductors are connected."

Another object of my --invention: is :to provide a metal disc which is attached or embedded-etc:

the-rubber connector plug whicmprovidestheanchorage for-the cable clamp.

Another object of my inventionris to? provide anrelectric connector with a'clamp which clamp may be attached to an anchor disc rapidly and easily.

Another object of my invention is to provide a cord clamp and an anchoring disc which are complementary to one another but which are complete of themselves and which require no tools to assemble.

Still another object of my invention is to provide a clamp which will assure the firm retention of the .cable or cord passing through it by means of the compression of the clamp and also, in addition the extra securing efiect resulting from the dimpling in the clamp which provides two high pressure points which prevents twisting of the cord or slippage.

Still another object of the invention is to provide a clamping device which will prevent misalignment by being sufficiently adjustable of the clamping assembly for such misalignment which might otherwise result.

Another object of my invention is to provide a plug type which will also allow for the quick and easy removal of the anchor plate which secures the clamp to the plug housing.

Still another object of the invention is to provide a clamp assembly directly into the rubber housing of the electrical plug and providing for its firm retention in the rubber housing and also, further providing by means of a recession in the rubber housing into which part of the clamp assembly projects, for any torque which might be exerted when adjusting the clamp, and thereby preventing the rotation of the clamp assembly in the rubber plug housing.

Other objects of my invention are to provide an improved device of the character described, that is easily and economically produced, which is sturdy in construction, and which is highly efficient in operation,

2-. With. thegabove and l related objects ;in view, my;inv ention :consistslin-the-detailsaof construc:

tion and combination; of parts, as -will be-.-mo re. fully understood from theffollowing;description, 1 when 2 read-Lin-v conjunction with the; accompanying-:draw-ingin which: 1

Fig.4 is a-.;side elevational. view ofianelectricahv connector. embodying:;myinven-tiom:

Fig. -2 is -a view" of the @connector-as seen along the line 2-4 of Fig. 1.;

Fig. .,3- 153a,! view-of; the conncctor; as :seen along the line 3-:--3 -of,-Fig.-l 1.

Fig. 4-;is :a.- sectional; ,viewtaken along the line 4-4 of Fig. 2'.

Fig. a side zelevational view of. another type eofelectrical connector-embodying my; invention.

Fig. 6 is an end view as seen along the line 66 of Fig. 5.

Fig. 7 is an end view as seen along the line 1-1 of Fig. 5

Fig. 8 is a sectional view as taken along the line 88 of Fig. 6.

Fig. 9 is a fragmentary sectional view of the housing alone.

Fig. 10 is an end view as seen along the line Ill-I0 of Fig. 9.

Fig. 11 is an end view as seen along the line Hll of of Fig. 9.

Fig. 12 is a sectional view as taken along the line l2l2 of Fig. 11.

Fig. 13 is a perspective view of the electrical cord clamp and the anchoring disc.

Referring now in detail to the drawing wherein similar reference characters refer to similar parts I show an electric plug which is adapted to connect a pair of electrical conductors to a complementary receptacle. The plug comprises a body, generally designated as A, which is of suitable insulating material. At one end of the body A is a disc II] to which a pair of plug prongs l2, 12 are attached. At the other end of the housing is an inner recess [4 into which recess the outer edge of a disc, generally designated as B, interfits. In other words, the disc B is locked to the housing A by engaging the housing recess Id. The disc B has a central opening l5 through which a cord l8 passes and a pair of slots l9, I9 which are longer than they are wide. Each of the slots is adapted to receive a T-shaped hook on one end of a clamp, generally designated as C. The T-shaped hook has a stem and a head attached to said stem. It is to be noted that the head goes under the under side of the disc B when the hook looks upon the disc. The clamp C has two identical parts each of which engage a part of the conductor iii. The clamp or strap C is a thin stamped metal piece having a curved central portion 22 with a slight indentation 24 therein so that the cord will not slip. A threaded screw opening or tapped bore 26 is to receive a threaded screw 28 and an elongated opening 30 is to the other side of the curved central portion 24.

It is to be seen that in assembling the unit about a conductor l8 the wires in the conductor are stripped and attached to the prongs [2, I2 the complementary clamps or straps C are locked into the disc by virtue of the complementary tongue or T-shaped end 20 and the opening 9. The tongue 20 cannot be pulled from the opening when the strap surrounds the cord l8 and then a screw 28 is pushed through a slot 38 in one strap and screwed into the tapped bore 26 in the second strap; since two screws are used a tight grip is formed. The tongue and opening l9 have sufiicient play to be self-adjusting, that is to say if the cord is not in the exact center the clamps may be moved.

It is to be particularly noted that the disc B and its clamps C, C are prevented from rotating with respect to the housing by virtue of the T-shaped tongue 20 engaging a small narrow recess 32 in the housing A. The recess 32 enables the tongue 20 to be located therein but it prevents the tongue from moving too far. If the disc and clamp could turn completely around then the conductors might be sheared from the terminals to which they are attached.

In Fig. 4 I show a modification of my invention wherein the disc Bi is clamped permanently to the housin Al.

Although my invention has been described in detail, such description is intended as being illustrative rather than limiting, since the invention may be variously embodied, and the scope of the invention is to. be determined as claimed.

I claim as my invention:

1. In an electrical connector comprising a cylindrical insulating body having an inner bore, a disc attached to said body, said disc having a pair of elongated apertures therein, a pair of detachable straps, each strap having a stem and head forming a T-shaped tongue therein, each of said tongues of each strap being disposed with its stem within one of said apertures, and its head engaging the under side of the disc and said pair of straps being adapted to clamp about an electric cord to relieve the strain imposed thereon.

2. The subject matter of claim 1, said body having a pair of recesses therein which are located beneath the disc recesses, and the T-shaped tongues being adapted to interfit with said body recesses to prevent relative rotary movement of said body and said disc.

JACOB SCHMIER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Date Number Name 342,194 Finnegan et a1 May 18, 1886 1,510,978 Conklin Oct. 7, 1924 1 579323 Hubbell Aug. 7, 1928 1,880,151 Peterson Sept. 27, 1932

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