US2947968A

US2947968A - Electrical termination

Info

Publication number: US2947968A
Application number: US649688A
Authority: US
Inventors: George C Mapelsden; Francis H Cowe
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1957-04-01
Filing date: 1957-04-01
Publication date: 1960-08-02
Anticipated expiration: 1977-08-02

Description

United States Patent ELECTRICAL TERMINATION George C. Mapelsden, Easton, and Francis H. Cowe, Devon, Conn, assignors to General Electric Company, a corporation of New York t 1 Filed Apr. 1, 1957, Ser.No. 649,688 3 Claims. or. 339-276) This invention relates to a means of crimping a wire conductor to an electrical contact or terminal. Portable electrical cords usually are provided with attachment plugs with two or more contacts or blades which are inserted into a convenience outlet for making an electrical connection. In some attachment plugs the contacts extend in a direction longitudinally of the cord, while in others the contacts are perpendicular to the cord. Such plugs in the latter category are oftentimes referred to as right angle plugs or merely as angle plugs.

The present invention finds its greatest use in angle plugs where the stranded wire is crimped to the contacts with a right angle crimp. This angular relation between the wire and the contact has fostered the use of the designation flag-type crimp for reasons which will be immediately apparent after studying the article in question. Previously, the wire conductors were fastened to the contacts of an angle plug in the same manner as in standard plugs so that the contacts were mere extensions of the conductors. However, this became very troublesome with the larger size conductors since the copper strands would oftentimes break when the conductors were bent at such a sharp angle before the plugs could be molded. This bending operation both stretches the outer strands of the conductors and work-hardens the material so that breakage may occur either in handling or during the molding operation. substitute a flag-type crimp so that little or no bending will be required in assembling the contacts in the mold ing machine.

The principal object of this invention is to provide an electrical connector with a flag-type. crimp having a special latching feature which will resist the loosening of the gripping force when the wire conductor is under tension.

A further object of this invention is to provide a flag-type crimp for the contacts of an angle plug having a special latching arrangement that will hold the crimped portion firmly in engagement with the wire and will not tend to shear the strands of the wire.

The preferred embodiment of this invention is illustrated in the drawing as it would be incorporated with the contact blade of an angle plug. The same invention would also be useful as a connection between a wire and a terminal member; or wherever a wire, be it solid or stranded, is to be connected to a thin strip of metal. A slotted opening is first formed adjacent one end of the strip and then a tab is lanced out of the strip to serve later as the latching member. In actual practice, the tab is formed from material adjacent the opening so that when it is folded back it enlarges the opening. The adjacent end of the strip containing the slottedopening is likewise preformed outwardly to lie parallel with the beforementioned tab to form a receiving section for a wire conductor. Such a conductor is placed crosswise of the opening and the end of the strip is rolled over the conductor to produce a tight grip. Finally, the tab is Our solution is to 2,947,968 Patented Aug. 2, 1960 room air conditioners.

Our invention will be better understood from the following description taken in connection with the accompanying drawing and its scope will be pointed out in the appended claims. 7

Figure 1 is a plan view of an electrical contact embodying our invention taken before the crimping operation.

Figure 2 is a right end view of the contact of Figure 1 showing the terminal end.

Figure 3 is a side elevational view of the contact of Figure 1.

Figure 4 is a partial view showing a blank of the material from which the contact is formed.

Figure 5 is an isometric view of the contact embodying our invention before the crimping operation takes place.

Figure 6 is an isometric view similar to that of Figure 5 with the wire crimped firmly to the contact.

Referring in detail to the drawing and in particular to Figure 5, 10 represents an electrical contact of thin metal strip material which is doubled over to form a two-ply blade construction with a short leg 11 and a long leg 12. The folded end of the contact has an anchor loop 13 for making good mechanical connection with the contacts (not shown) of a convenience outlet. A circular aperture 14 through the contact adjacent the anchor loop 13 is also provided for increasing the mechanical holding force between the contact and a receptacle. The free end 15 of the short leg 11 is bent outwardly at a right angle to the main portion of the contact so that when a plug is molded over the end of the contact, the portion 15 will serve to anchor the contact and prevent displacement and withdrawal.

The novel portion of our invention may be seen at the free or terminal end 16 of the long leg 12 of the contact. A slotted opening 17 is made in the terminal end, and a tab 18 is lanced out of the material forming one edge of the opening. This opening 17 is spaced from the edges of terminal end 16, with a transverse rib spacing it from the outer transverse edge of the terminal end 16. (See Fig. 5.) This tab 18 is bent at a right angle, and in so doing the slotted opening 17 is enlarged to the dimensions as shown. Figure 4 shows a blank of the portion of the long leg 12 of the contact where the tab 18 is situated in the plane of the leg. It should be understood, however, that the tab 18 is not cut as shown in Figure 4 and then folded, but that it is lanced or struck out of the material of the contact in one operation.

Looking at Figure 3, the terminal end 16 is made with a partial loop 20 that is open upwardly and an upstanding portion that lies parallel with the lanced tab 18. This is the condition of the contact just prior to the assembly of the wire conductor 21 of Figure 6. The conductor is placed in the loop portion 20 across the slotted opening 17 and between the terminal end 16 and the tab 18. Then the terminal end 16 is rolled over the conductor so that the free edge of the terminal end 16 lies adjacent the base of the tab 18. This type of connection would be satisfactory in many situations, but the tab 18 is an additional precaution that will prevent the terminal end 16 from springing back and releasing its grip onpthe conductor. Tab 18 is formed over the terminal end where it latches into the slotted opening 17 as shown in Figure 6. The tab 18 is not actually crimped over the conductor, but it is crimped over the terminal end of the contact.

Having described above our invention of a novel flagtype crimp for an electrical connector, it should be clear to those skilled in this art that the resulting product is both simple to manufacture and reliable in operation. It is'so designed that it is well adapted to mass production methods of stamping by progressive dies, and it represents a decided improvement in angle plugs over previous methods of crimping thev contacts where the contacts extended longitudinally of the conductors.

Modifications of our invention will occur to those skilled in this art, and it is; to be understood, therefore, that; this invention is not. limited, to the particular embodiments disclosed, but that it is intended to cover all modifications which are within the true spirit and scope of thisv inventon.

What we claim is new and desire to secure by Letters Patent of the United, States is:

1. An electrical connector of thin metal strip having a terminal end that is to be crimped over a bare conductor, a lanced tab struck out of one side of the terminal end of said stirp to establish an opening in the end that is spaced from the edges of the strip, a bare wire lying across the terminal end and over the opening, the terminal end being rolled over the wire on said side of said strip to hold the wire firmly in place, the tab also being rolled over the crimped portion of the terminal end to WIIG.

2. An electrical connector of thin metal strip of doubled=over construction comprising a long and a short leg, the free end of the long leg having a slotted opening that is spaced from the edges of the strip, said opening being spaced from the outer transverse edge of the free end by a transverse rib, a lanced tab struck from said strip and projecting outwardly from one side of said strip, a wire conductor extending across said strip and lying over said opening, said free end of said strip being folded over said conductor with the transverse rib of said strip adjacent said side of said strip, said tab formed over the free end and latched into the opening to engage said rib and hold the free end of the strip from releasing its grip on the conductor.

3. An electrical connector of thin metal material comprising a slotted opening adjacent one end, said opening spaced from the outer transverse edge of said end by a transverse rib, a wire conductor lying across the end of the connector and over the opening, said end of the material being folded over the conductor to hold it in a tight grip, said transverse rib disposed on one side of said strip, and a tab extending outwardly from said side of said strip and folded over said rib and latched into the opening to hold the end from releasing its grip on the conductor.

References Cited in the-file of this patent UNITED STATES PATENTS 445,491 Biesen Jan. 27, 1891 2,445,537 Schaefier July 20, 1948 2,659,871 Berg Nov. 17, 1953 2,765,454 Long Oct. 2, 1956 2,845,108 Hammell et a1. July 29, 1958