US2033960A

US2033960A - Attachment plug cap

Info

Publication number: US2033960A
Application number: US538956A
Authority: US
Inventors: Frank J Tiffany
Original assignee: Harvey Hubbell Inc
Current assignee: Harvey Hubbell Inc
Priority date: 1931-05-21
Filing date: 1931-05-21
Publication date: 1936-03-17
Anticipated expiration: 1953-03-17

Description

F. J. TIFFANY ATTACHMENT PLUG CAP March 17, 19.36.

Filed May 21, 1931 Patented Mar. 17, 1936 PATENT OFFICE ATTACHMENT PLUG CAP Frank J. Tiffany, Bridgeport, Conn., assignor to Harvey Hubbell, Inc., Bridgeport, Conn., a corporation of Connecticut Application May 21, 1931, Serial No. 538,956

Claims. (Cl. 173-361) This invention relates to new and useful improvements in attachment plug caps and particularly to attachment plug caps adapted to be used in garages, factories or the like where they are liable to be subjected to rough handling, and is equally applicable to attachment plug caps including two, three or more blades.

An object of the invention is to provide an attachment plug cap including a body of unbreakable material such as live rubber whereby the body of the cap will not become cracked'or broken when brought into contact with a hard object as when dropped on a floor or the like, and whereby the cap will withstand rough usage.

Another object is to provide an attachment plug cap including a body of resilient rubber and wherein the contact blades are so secured to the body that when the blades are forcibly brought into contact with a hard object the blades will not be bent but the body will yield to protect the blades. 7

A further object is to provide an attachment plug cap including a body of resilient rubber, a plate secured to, the back of the body to stiffen the same and said plate serving also to secure a cable or cord clamp to the body.

An additional object is to. provide an attachment plug cap including a resilient rubber body and improved means for securing contact blades to the body whereby lateral stress applied to the blades will be transmitted to and taken up by the body to prevent bending of the blades.

Other objects and advantages will become apparent from a consideration of the following detailed description taken in connection with the accompanying drawing wherein a satisfactory embodiment of the invention is shown. However, it will be understood that the invention is not limited to the details disclosed but includes all such variations and modifications as fall within the spirit of the invention and the scope of the appended claims to which claims reference is o to be had for a definition of the invention.

In the drawing: I

Fig. l is a transverse sectional view on the line i-lof Fi 3;

Fig. 2 is a top plan view of the improved attachment plug cap;

Fig. 3 is a bottom plan view thereof;

Fig. 4 is a side elevational view thereof on a reduced scale;

Fig. 5 is a sectional view thereof showing a detail of construction the view being taken alongthe line 55 of Fig. 3; and

Fig. 6 is a plan view of a portion of the body of the new attachment plug cap, the back plate being omitted.

Referring in detail to the drawing the improved attachment plug cap of the present invention is shown as including a body It preferably formed right angles to the blade proper and adapted to of live rubber and which while herein shown is in the form of a relatively thick disc or cylinder may of course have any desired shape.

At its outer or upper side the body Ill receives or has applied against it a metal stiffening plate II which plate may conform generally to the shape of the body. Preferably the body is recessed to receive the plate ll whereby when the plate is applied to the body the edges of the plate will be protected by the material of the body. This is as shown at l2 in Figs. 1 and 5. While a number of means for securing the plate II to the body will readily suggest themselves it is pre ferred that the plate be secured as by means of rivets l3 which pass entirely through the body and have their heads at the lower side of the body recessed into the body whereby they lie flush with the surface of the body or below such surface.

The lower or inner side of the body is recessed as at l4 to receive the contact blades and the means for attaching these blades. As herein shown, the attachment plug cap includes three contact blades 15 for use with a three wire system, one contact being for the grounded or neutral wire, although it will be obvious that the invention is applicable to a two blade attachment plug cap or for use with any number of blades desired. Each blade 15 includes a relatively large anchoring or attaching portion l6 arranged at be secured against the inner side of the body l0 and within the recess 14.

As here shown each contact blade I5 is secured to the body by two rivets indicated respectively at I! and I8. These rivets of course pass through the portions I6 of the respective blades. Entering the body from the outer or upper side thereof are wells or recesses l9 and 20, there being one well or recess IQ for each rivet l1 and one well or recess 20 for each rivet I8. The heads 2| of the rivets H are disposed in the recesses l9 and an inspection of Fig. 5 will show that these heads are disposed a considerable distance below the plate I l whereby there will be no danger of short circuiting.

Recesses 20 are non-circular in cross section and such recesses are here shown as square. This is to prevent turning of the rivets l8 and-in order that the heads 22 of the rivets will properly cooperate with the recesses these heads are prefer- 5o ably square. The rivets iii are tapped to receive binding screws 23 whereby in addition to functioning in the securing of the contact blades to the body these rivets form an anchoring means for the binding screws. The ends of rivets l1 and I8 are, of course, upset against the outer surface of the portions N5 of the contact blades whereby to secure the blades against the body.

.Extending centrally through the body In is an opening 24 adapted to receive a cord 25 which preferably includes a heavy rubber covering encasing conductors 26 one of which in a three Wire system provides a grounded or neutral wire. In its upper or outer surface the body III has a pair of opposed grooves 21 and 28 which extend radially from the opening 24 to a point spaced from the sides of the body. These grooves are below the stiffening plate II. y

In addition to performing as a stiffening member the plate I I also serves to secure a cord clamp 29 to the body. This cord clamp includes a pair of similar sections 30 and 3I each of which is substantially L-shaped, including an attaching or foot piece 32 adapted to be received in one or the other of the grooves 21 and 28 under the plate II. As shown in the accompanying drawing the foot piece 32 of the section 30 is received in the groove 21 while the foot piece 32 of the section 3I is received in the groove 28.

Plate I I being disposed over the foot pieces 32 of the respective sections will, of course, serve to secure the sections to the body and the sections may be moved toward and from each other and in such movement will be guided by the walls of the grooves 21 and 28 and plate II. The sections 30 and 3I are adapted to clamp a cord between them, as for example the cord 25, and means are therefore provided for drawing the sections toward one another. As here shown this means includes a pair of laterally extending ears 33 on the section 30 and apair of laterally extending ears 34 on the section 3|. These ears are arranged opposite each other and screws 35 each passing through one ear 34 and one ear 33 have threaded connection with the ears 33 and when tightened serve to draw the sections against the cord.

It will therefore appear that plate II performs its two functions and secures" the cord clamp to the body in such a manner that its sections may be easily adjusted toward and from each other but are so secured that any pull on the cord will be taken up by the clamp and transmitted to the plate. Thus the pull on the cord is not transmitted to the connections of the leads with-the binding screws. Also, attention is directed to the fact that the body I0 being of live rubber will not become cracked or broken when dropped on a floor or struck against a hard object and that the improved attachment plug cap is therefore particularly adapted for use in factories, garages or the like where it will receive harsh treatment.

The mounting for the contact blades is such that these blades are protected in that if the attachment plug .cap is dropped on the blades or should the blades in any other manner be brought smartly against a hard object the body will yield permitting the blades?) yield and the blades will not be bent. Any reasonable lateral force, or any reasonable force applied laterally to the blades will result in movement of the blades but this movement will be due to a yielding of the body I0 as the force is transmitted to the body through the rivets I1 and I8.

Having thus set forth the nature of my invention, what I claim is:

1. In anattachment plug cap, a body of live rubber, a contact blade secured to said body and extending from one side thereof, said body having an opening therethrough for a cord, said body having a recess in its side opposite that from which the blade extends, a stiifening plate secured in said recess and having an opening aligning with the opening in the body, said stiffening plate being of substantially the diameter of said body, a cord clamp comprising a pair of sections each of which is substantially L-shaped, each of said sections having an arm disposed below said stiffening plate whereby the sections are secured to the body, and means to draw said sections toward each other to have them clamp a cord entering the opening through the body.

2. In an attachment plug cap, a body of live I rubber, a contact blade secured to said body and includes a mounting arm disposed in one of, said grooves'and below the stifiening plate whereby the sections are secured to the body and guided for movement toward and from each other, and means to draw said sections toward each other to have them clamp a cord entering the opening through the body.

3. In an attachment plug cap, a body of live rubber, said body recessed in its opposite sides,

a contact blade secured in the recess at one side of the body and extending outwardly therefrom, said body having relatively deep wells entering from the recessed side opposite that to which the blade is attached, means having their heads in said wells and extending through the body and securing the contact blade to the body, one of said wells and the head of one of said means being non-circular whereby to prevent turning of the means, a binding screw threaded to said means, and a stiifening plate secured in the recess at the side of the body opposite the side from which the contact blade extends.

4. In an attachment plug cap, a body of live rubber, said body recessed in its opposite sides, a contact blade secured in the recess at one side of the body and extending outwardly therefrom, said body having a relatively deep well entering from the recessed side of the body opposite that to which the blade is attached, means having its head in the lower portion of said well and extending through the body and securing the contact blade to the body, and a stiffening plate secured in the recess at the side of the body opposite the side from which the contact blade extends. l

5. In anattachment plug cap, a body of live rubber, a contact blade secured to said body and extending from one side thereof, a stiffening plate, means securing said plate to the body against the other side thereof, said body and plate having aligned openings for the passage of a cord, a cord clamp comprising a pair of sections each including an arm extending outwardly through the opening in the plate and an arm extending radially of said opening at the body side of the plate whereby the plate secures the sections to the body, and means to move said clamp sections toward each other to have them clamp a cord passing through the opening in the plate.

FRANK J. TIFFANY.