US2406144A

US2406144A - Contact blade assembly

Info

Publication number: US2406144A
Application number: US398098A
Authority: US
Inventors: William P Herman
Original assignee: Individual
Current assignee: Individual
Priority date: 1941-06-14
Filing date: 1941-06-14
Publication date: 1946-08-20
Anticipated expiration: 1963-08-20

Description

Aug. :20, 1946 w. P. HERMAN 2,406,144 CONTACT BLADE ASSEMBLY I V Filed June 14, 1941 INVENTOR ATTORNEY Patented Aug. 20, 1946 CONTACT BLADE ASSEMBLY William P. Herman, Providence, R. I. Application June 14, 1941, Serial No. 398,098

2 Claims.

My present invention relates to the manufacture of electrical contact plugs and has particular reference to a novel construction of contact blades and novel methods of assembly of the contact blade with the electric cord.

This application is a continuation in part of my copending application Ser. No. 188,262, filed February 2, 1938, and entitled Contact plug assembly, issued July 8, 1941, Patent No. 2,248,082.

It is the principal object of my invention to provide a contact blade which'is firmly attached to the cord lead wire against pulls and abnormal strains.

It is an additional object of my invention to provide a contact blade which can be so attached to the end of a cord lead wire as to provide a strain relief which will withstand much more than the minimum required by the Underwriters Laboratories.

Another object of my invention is to provide various methods which will facilitate the securing of cord lead wire to the contact blade, which are easy and economical to practice, and which will facilitate assembly of the final plug.

With the above and other advantageous features in View, my invention consists of a novel arrangement of parts, and novel methods of manufacture and assembly, more fully disclosed in the detailed description following, in conjunction with the accompanyin drawing, and more specifically defined in the claims appended hereto.

In the drawing,

Fig. l is a perspective view of a self-anchoring contact blade embodying my invention;

Fig. 2 is an edge view thereof with the cord lead wire inserted therein preparatory to solder- Fig. 3 is a similar View, the cord lead wire being passed through the second slot after soldering;

Fig. 4 is a perspective view of the blade and cord soldered and ready for assembly;

Fig. 5 is a plan view thereof.

In the manufacture of electrical contact plugs, it has been found desirable to eliminate the use of screws, clamps, or other outside anchoring means. It is therefore necessary to provide a blade and cord lead connection which affords a positive electrical contact of sufiicient strength to meet the requirements of the Underwriters Laboratories. While the present invention may be applied to any type of blade, for the purposes of illustration I have shown the invention as applied to a self-anchoring blade having intermediate shoulders for interlocking with a plug slot.

Referring more in detail to the drawing illustrating my invention, and particularly Fig. 1 thereof, the contact blade illustrated is preferably stamped in one, flat, integral piece. The blade comprises the conventional contact portion 32, the intermediate self-anchoring portion, and the upper cord receiving portion.

The upper cord receiving portion of the blade 32 is provided with a transverse slot 33 adjacent to its upper end, and a second transverse slot 34 below the slot 33 and extending from the opposite edge of the blade 32. The slot 34 preferably extends inwardly from the blad edge at a slight upward angle so that tension or pull on the cord lead wire will tend to slide the wire into the slot rather than outwardly.

The blade 32 may be soldered or spot welded to the lead wire. The bared end 35, of a cord 35, is attached to the upper edge of the blade 32, either by soldering or welding, as shown in Fig. 2. The wire is then passed through the slot 33, back through the slot 34, see Fig. 3, and then reentrantly bent into the position shown in Figs. 4 and 5 ready for assembly.

This construction provides a strong relief against stresses and strains. Any strain on the cord is taken up by the convolutions of the insulated portion of the conductor through the slots of the blade and very little of the strain is transmitted to the bared contact portion.

While I have described a specific constructional embodiment of my invention, and a Specific method of assembly, size and shape of the parts, in their relative arrangement, and in the method of assembly, may be made to suit the requirements for difierent plug designs, without departing from the spirit and the scope of the invention as defined in the appended claims.

I claim:

1. In combination, a contact blade for an electrical contact plug comprising a flat, one-piece, rigid stamping of generally elongated form and having two spaced transverse slots extending inwardly from opposite side edges adjacent the upper portion of said blade, the lower slot extending inwardly at an upward angle, and an insulated cord lead wire having its bared end fixed to one side of said blade adjacent the upper slot and extending upwardly above the upper slot, said insulated wire passing alternately through the upper and then the lower slots and being bent to extend upwardly in alignment with said blade.

2. In combination, a contact blade for an electrical contact plug comprising a flat, one-piece,

it is obvious that changes in the wire having its bared end fixed to one side of said 5 rigid stamping of generally elongated form and wardly above the upper slot, said insulated wire having two spaced transvers slots extending inpassing alternately through the upper and then wardly from the side and adjacent the upper the lower slots and being bent to extend upwardly portion of said blade, and an insulated cord lead in alignment with said blade.

blade adjacent the upper slot and extending up- WILLIAM P. HERMAN.