US3613052A

US3613052A - Electrical locking pin terminal

Info

Publication number: US3613052A
Application number: US6104A
Authority: US
Inventors: Frederick Jean Maltais
Original assignee: AMP Inc
Current assignee: TE Connectivity Corp
Priority date: 1970-01-27
Filing date: 1970-01-27
Publication date: 1971-10-12
Anticipated expiration: 1988-10-12

Abstract

A hollow tubular locking pin terminal for securement in a sphinctered opening is provided with a resilient lance means extending axially within the terminal and having a locking member extending through an opening in the wall of the terminal to lock behind the constriction in the sphinctered opening. The tubular pin terminal including the resilient lance and locking member are all made from a unitary blank.

Description

United States Patent [72] Inventor Frederick Jean Maltais Camp Hill, Pa. [21] Appl. No. 6,104 [22] Filed Jan. 27, 1970 [45] Patented Oct. 12, 1971 [73] Assignee AMP Incorporated Harrisburg, Pa.

[54] ELECTRICAL LOCKING PIN TERMINAL 7 Claims, 5 Drawing Figs.

[52] US. Cl 339/217 S [51] Int. Cl H0lr 9/12 [50] Field of Search 339/217, 91, 252,213, 256, 258

[56] References Cited UNITED STATES PATENTS 3,085,222 4/1963 Watts 339/217 3,425,029 1/1969 Zak 339/252 3,513,438 5/1970 Henschen et a1. 339/217 F OREIGN PATENTS 1,355,758 2/1964 France 339/217 S Primary Examiner-Marvin A. Champion Assistant Examiner-Robert A. I-Iafer Attorneys-Curtis, Morris and Satford, William J. Keating,

Ronald D. Grefe, William Hintze, Adrian .1. La Rue, Frederick W. Raring, Jay L. Seitchik and John P. Vandenburg ABSTRACT: A hollow tubular locking pin terminal for securement in a sphinctered opening is provided with a resilient lance means extending axially within the terminal and having a locking member extending through an opening in the wall of the terminal to lock behind the constriction in the sphinctered opening. The tubular pin terminal including the resilient lance and locking member are all made from a unitary blank.

PATENTEU U 1219?! 3,613,052

I/Vl/E/VTOR FREDERICK JEAN MALTAIS ELECTRICAL LOCKING PIN TERMINAL The invention relates to an electrical locking pin terminal and the method of making such terminal.

It is essential in many cases, to ensure that a pin terminal after insertion into a mating socket or opening, be securely held therein so that it does not fall out due to rough handling or vibration and that it may not be easily withdrawn by persons unauthorized to do so. To those ends, the mating opening or socket for the terminal is sphinctered or constricted intermediate its ends. The terminal is made hollow and provided with a locking member or lance which is mounted on a resilient member within the terminal and extends through an opening therein to look behind the constriction when housed in the opening to prevent its withdrawal. The locking member is so mounted and constructed that upon an attempt to withdraw the pin from the socket, the lance tends to project still further from the slot and the forward face of the lance or locking member is forced against the edge of the opening in the pin body, preventing lance depression and locking the pin in place.

In order to mass produce such pin terminal in a simple and economical manner, I provide a single blank which may be stamped out in a single operation and from which the hollow pin terminal, including the locking member with its resilient mounting, may be integrally formed.

It is therefore an object of this invention to provide a locking pin terminal especially for use with a sphinctered opening.

It is a further object of the invention to provide a complete locking pin terminal out of a single metal blank.

It is still a further object of the invention to provide a pin terminal which cannot fall out of a mating hole or be extracted from such hole without the use of a tool.

These and other objects and advantages of the invention will appear more fully in the description of the invention with specific reference to the drawings, in which:

FIG. 1 shows the locking pin terminal of the invention in perspective;

FIG. 2 is a cross section of the pin terminal of FIG. 1 along the line 2-2, with the right-hand end portion showing the conductive connection to the terminal omitted;

FKG. 3 is a plan view of the blank from which the pin terminal of FIG. 1 is formed, an end portion thereof being omitted;

FlGS. 4 and 5 are cross-sectional views of the terminal taken along lines 4-4 and 5-5 respectively of FIG. 2.

First referring to the blank from which the pin terminal is formed, it can be seen that the blank, which is of flat stock material, has a body portion 4 which is substantially rectangular in shape having straight parallel sides 3 and 3' and is substantially crenellated at the forward end 5, as shown in FIG. 3. At the other end of the body portion 4, the blank is necked down, as at 9, and terminates in a further region, not shown in FIG. 3, but shown to the right in FIG. 1. Such region, designated as 1 1, is part of the flat stock material of the blank which is bent into tubular forms as later described and thus crimped in a conventional manner to a conductor to form an electrical connection therewith. A rectangular slot or opening 2 is provided in the body portion 4 of the blank at a substantially central location thereof. An arm or tongue member 6, spaced from one side of the body portion and extending therealong for a short distance is integrally connected to the side of the body portion 4 of the blank by a bridging section 8. For purposes to be described later, the body portion 4 is notched, as at 10, adjacent to the side of the bridging section closer to the opening 2. The distance between the outer edge 7 of the tongue and the bottom of the notch 10 is substantially that between side 3 and the longitudinal center of the slot 2.

The free end of the arm or tongue 6 terminates at substantially the same distance from one end of the blank as the farthest edge of the opening or slot 2 is from that end. The terminal portion 12 at the free end of the arm extends laterally outward and is of substantially the same length as the slot. The laterally outermost edge 14 of the portion 12 extends at an angle to the straight side 3 of the body portion 4, being further from the side 3 at the extreme free end of the tongue 6. The rear edge 16 of the outstanding portion 12 tapers forwardly as it approaches the same side. Between the slot 2 and the necked-down narrower portion 9, the blank is provided with pairs of parallel coextensive slits 20 extending in a transverse direction. The forward and rearward slits 20 are in respective alignment in a direction transverse to the body portion 4. Rearwardly of the slits 20, the blank is further provided with pairs of parallel coextensive slits 22 extending lengthwise of the body portion. Adjacent the forward end of the body portion 4 of the blank, the side 3' is provided with a notch 24 at a location transversely opposite to that of the bridging section 8 and is of a length somewhat exceeding that of the last mentioned section. As can be seen from the above description of the blank from which the locking terminal pin is made, it can be stamped out of flat stock or otherwise formed of normally used electrical terminal materials.

To form the locking pin terminal shown in FIG. 1, the bridging section in FIG. 3 may first be bent upwardly through an arc of from the plane of the paper. The blank is then bent into tubular form about a central longitudinal axis so that the tongue 6 is encompassed to extend substantially along the axis when the sides 3, 3' of the body portion meet. At this point, the outstanding section 12 will extend into the opening 2. Before the bending operation, the crenellations at the forward end of the blank can be dished and so shaped that when the blank assumes the tubular form, they can be folded over to meet at their side and forward edges as shown in FIG. 1, to form a smooth and rounded forward end for easy insertion into an opening. Also, the material between the

slots

20 and 22 may be forced outwardly to form

projections

24 and 26 respectively without breaking or tearing the material before bending the blank into tubular form. Preferably however, the blank may be formed into the desired shape on a mandrel which is slitted axially along a portion of its length, to accommodate the tongue or arm 6 and to permit the enlarged portion 12 to extend into the opening and to then slide the formed pin off the mandrel. It is obvious, of course, that the end of the mandrel corresponding to the forward or nose end of the terminal would be round and smooth so as to allow the crenellated end of the blank to be formed thereon to assume the same shape, as shown in FIGS. 1 and 2. The resultant pin terminal is therefore tubular in shape and encompasses therewithin a lance means provided by the arm 6 and enlarged locking portion 12 integrally formed from the metal of the pin. The length of the lance means and the use of the bridging section 8 for hinging it to the pin proper, is closed to provide a low lance depression force and the stress at the hinge area is within the allowable working stress of normally used electrical materials. The natural resiliency of the metal tends to project the locking portion 12 of the lance means through the opening 2 regardless of the number of times the locking portion is depressed. The opening 26 in a block B, into which the pin terminal of the invention is inserted and secured, is sphinctered. Such an opening may be formed by counterboring the rear end of the opening or both ends if so desired, in the manner shown in FIG. 2. As can be seen, the projecting members or stops 24 are spaced rearwardly of the rearmost edge of the locking member 12 by at least the thickness of the wall 30 which constricts the diameter of the opening 28. When the pin terminal is inserted into the opening 28 in the block B with the forward end or nose 5 first in the direction of the arrow, the lance means is depressed as the locking member 12 engages the inner edge of wall 30 until it passes the forward surface of the wall and resiliently locks thereagainst. At this time the projections or stops engage the rear surface of the wall so that the pin terminal is prevented from either forward or rearward movement. The stops 26 on the pin terminal are of a height to substantially make contact with the wall of the counterbored opening 28 to prevent movement of the pin radially of the opening.

As fully shown and described above, the pin terminal is so constructed that when locked in a sphinctered opening any attempt to extract it from such opening, by pulling in a direction counter to the arrow, would cause the rear edge 16 of the locking member to cam against the edge of wall 30 and pull the lance means upwardly and locking member further out of the pin body. Should the lance means tend to bend or buckle under greater extraction force, the forward edge 18 of the locking portion would be forced against the forward edge of slot 2 in the pin body, and by reason of its forwardly facing angle, prevent lance depression and lock the pin place. Where the opening in the block is counterbored at its forward as shown in FIG. 2, the pin may be extracted by sliding a flat rigid member over the locking member in the wider portion of the opening to depress it. Where the block B, with one or more openings therein, is mounted at a location where its forward side is not accessible to authorized personnel, it is obvious that the locking pin could not be withdrawn. If the block B is utilized with electrical devices subjected to jarring or vibration, the lockin pin of the invention is held therein so securely that danger of falling out and perhaps disconnecting a circuit, is avoided.

While a preferred embodiment of the invention has been illustrated, many obvious modifications may be made without departing from the spirit and scope of the invention and the claims are to be construed as covering such obvious modifications.

What is claimed is:

1. A tubular electrical terminal member for insertion into an opening in a body which is constricted by an inwardly directed wall having forward and rear surfaces comprising, an opening in the wall of the tubular member, resilient lance means connected to the tubular member and extending in an axial direction interiorly thereof, the lance means being provided adjacent its free end with locking means having forward and rearward edges extending therefrom and projecting through the opening, the lance means being of a greater width than thickness and integrally connected at its forward end by tongue means to the tubular member adjacent its forward end and with a side defining its width extending in a plane substantially parallel to a radial plane, the tubular member having means at its rear end for connection to a conductor.

2. A tubular electrical terminal member according to claim 1 in which the rear edge of the locking means tapers rearwardly from its connection to the tongue means, to provide a camming means cooperating with the forward side of the constricting wall upon movement of the tubular member rearward, to project the locking means further outwardly from the opening.

3. A tubular electrical terminal member according to claim 2 wherein the outermost edge of the locking means tapers outwardly from its forward edge to its rear edge to pennit insertion of a tool in the body opening to unlock the lance means from the constricting wall.

4. A tubular electrical terminal member according to claim 3 in which the locking means is an integral radial extension of the lance means adjacent the free end thereof and has its forward edge adjacent to the forward edge of the opening to resist forward movement of the lance means.

5. A tubular electrical terminal member according to claim 4 in which the forward edge of the locking means tapers rearwardly inward toward the lance means and cooperates with the forward edge of the opening to prevent inward movement of the lance means.

6. A tubular electrical terminal member according to claim 5 wherein the tubular member is provided with at least one outwardly extending projection rearwardly of the locking means at a distance at least equal to the thickness of the constricting wall and of a height to contact the rear wall surface, when the tubular member is inserted into the body opening.

7. A tubular electrical terminal member according to claim 6 including at least one further outward projection on said tubular member located rearward] of the first projections and of a height to engage the wall of e opening rearwardly of the constricting wall.

Claims

3. A tubular electrical terminal member according to claim 2 wherein the outermost edge of the locking means tapers outwardly from its forward edge to its rear edge to permit insertion of a tool in the body opening to unlock the lance means from the constricting wall.

7. A tubular electrical terminal member according to claim 6 including at least one further outward projection on said tubular member located rearwardly of the first projections and of a height to engage the wall of the opening rearwardly of the constricting wall.