US2691146A - Snap latch plug - Google Patents

Description

0st. 5, 1954 s. w. PoLLocK 2,691,146

SNAP LATCH PLUG Filed MEICh l, 1951 BY 25a ATTORNEY I Patented Oct. 5, 1954 SNAP LATCH PLUG Samuel Wilson Pollock, Camp Hill, Pa., assigner to Aircraft-Marine Products, Inc., Harrisburg,

Application March 1, 1951, Serial No. 213,310

9 Claims.

This invention relates to electrical connectors of the type adapted for quick insertion and withdrawal, often referred to as hand plugs and more particularly in the illustrative forms set forth hereinafter to latch plugs wherein the latch is released only by a pull on the Wire.

In modern day electrical equipment, it is common practice to employ connector panels or boards wherein connector plugs are inserted selectively in corresponding receptacles to connect and disconnect the various control circuits. It is desirable that the plug be easily removable by a pull from the outside of the panel but not removable by the push of the contact spring on the plug nose from the inside.

It is accordingly an object of this invention to provide a snap latch plug removable by a pull from the outer end. Another Aobject is to provide a snap latch plug that will not be ejected by a push on the tip or by vibration. It is a further object to provide a snap latch plug that will not become disassembled so as to drop short-circuiting parts behind the panel. A still further object s to provide a plug that is easily mass produced and substantially foolproof in operation. Other objects will in part be pointed out as the description proceeds and will in part become apparent therefrom.

I have discovered that the foregoing may be readily accomplished by providing a resiliently actuated latch depressible by cam action during insertion and retractable by a pull on the end into which the conducting wire is inserted but engaging fully against other forces which would tend to eject the plug.

In this specication and the accompanying drawings I have shown and described preferred embodiments of my invention and suggested various modifications thereof; but it is to be understood that these are not intended to be exhaustive nor limiting of the invention but, on the contrary, are given for purposes of illustration in order that others skilled in the art may fully understand the invention and the principles thereof and the manner of applying it in various forms, each as may be best suited to the conditions of a particular use.

The principles of the invention will be more readily perceived in connection with the following detailed description of specific illustrative embodiments and from the accompanying drawings in which:

Figure 1 is a sectional view of a plug of the cam actuated latch type partially inserted in the board;

Figure 2 is a sectional View of the plug of Figure 1 fully inserted;

Figure 3 is a plan View of the plug of Figure 2;

Figure 4 is a sectional view of another embodiment of a cam actuated latch type plug; and

Figure 5 is a section taken along line 5-5 of Figure 4.

Referring to Figures 1-3, a conducting wire 20 is crimped into a metal sleeve 22 which is part of a terminal connector 24 arranged to slide within the hollow plug shell 26. The terminal 24 presents a conical cam surface 2'! with a depression 28 at one end and a stop 3i! at the other which engage a detent 32, one of the two fingers of the resilient latch section 34 of the plug shell 26.

In operation the plug is inserted into a receptacle in the board 35 with the latch section 34 in its normal flush relation (as shown in Figure l). After the plug is fully inserted, a push on the wire effects a cam action of the cam portion 27 against the latch detent 32 as the plunger is forced forward in the shell. This lifts the latch 313 so that its straight finger engages the board 35 to prevent withdrawal. When fully inserted, the detent 32 drops into depression 28 to serve as a stop against accidental pull on the wire and against vibration, etc. The latch section 34 does not drop far enough to permit the plug to be pushed out by the force of contact spring 38, or to relax the spring effect of section 34, which thus maintains good Contact pressure between the terminal 24 and the shell 25.

When it is desired to withdraw the plug, the conducting wire is pulled, which draws the terminal 2A to the rear until detent 32 abuts the head 30 and allows the latch section to lie flush again. Further pull is transmitted by stop 30 to the shell 26 and the plug is thus withdrawn as a unit.

Thus this hand plug can be easily withdrawn by a pull from the outside and yet cannot be pushed out from the inside.

In this embodiment while I obtain a simple positive action, it is necessary to push the wire and sleeve into the plug to engage the latch. In Figure 4 is shown a self-latching plug that requires nothing more than insertion of the plug to engage the latch.

The conducting wire 20a is crimped into a sleeve 22a of the terminal 2da which is adapted to slide within shell 26a. Latch spring Bda is formed so as to normally project through opening 38 with a cam part 32a and its end adapted to abut against the board 35.

In inserting, the latch spring 34a, is depressed by its own cam section 32a on contacting the panel board 35, until the .plug is inserted far enough to allow it to snap up on the inside and latch against the board as shown in Figure 4. In removing ythe plug, a pull on the wire 20a causes section 40 (Figures 4 and 5) at the end of terminal 24a to cam the latch spring down until it is flush and Iallows the .plug to be withdrawn. The latch spring 34a is made to contact the nose of the plug before the cam section 32a can contact the shell 26a so the spring pressure on the nose cannot cam the section 32a of the spring back into the shell so as to permit the plug to be ejected by a push on the tip. The latch spring 34a land terminal 24a are keyed to the shell by projection 42 to `prevent accidental disassembly. -A slot 43 in the terminal accommodates the relative movement of the terminal in the shell. An insulating sleeve 44 is shown attached to the end of theshell but is not essential to the present invention.

In this embodiment, I thus obtain a plug that requires no special insertion procedure, is easily mass produced, since all parts can be made as stampings, and which meets the requirements of not being ejected by vibration or -pressure yet being easy to withdraw by a pull on the wire.

Various modifications and additional applications will suggest themselves to those skilled in the art. These embodiments shown are only by way of illustration and not limitation; all those modiiica'tions within the spirit of this invention being intended to be covered in the appended claims.

I' claim:

1. A Ahand plug of the ty-pe adapted to be connected to a wire and inserted into and withdrawn from a plugboard only by a pull on the wire, comprising, an integral outer shell open at one end and being closed and tapered at the other; an enlarged portion at said open end, an opening in said shell; a spring member having a latch portion positioned within said shell with said latch portion .projecting through said opening in position to be engaged with the rear face of said plugboard; a cam member positioned within said shell having at one end a cam bar engaging said spring latch and carrying yat the other end in said enlarged shell portion a ferrule forming portion whereby when a wire is engaged in said ferrule portion a pull on said Wire will `cam said latch into said shell to vpermit withdrawal of said plug from the plugboard.

2. A hand plug as described in claim 1 wherein said plug shell has a second opening therein and said second opening carries thereon a detent yportion extending into said second hole to prevent accidental disassembly of said spring member, cam member and shell portion.

3. An electrical connector of the type adapted to be inserted into a plugboard comprising a shell, a terminal slidably mounted in said shell and adapted for connection to a wire inserted therein, a latch, means to laterally project said latch through said shell for engagement with the plugboard when said connector is mounted therein, and means operative upon relative axial movement of said terminal and said shell to withdraw said latch from engagement.

4. An electrical connector of the type adapted to be inserted into a plugboard yand held therein by a latching means releasable only by a pull on a wire connected to said plug which comprises a unitary shell portion, a latch member adapted to laterally extend from said shell into engagement with the rear face of said plugboard to secure said plug against removal from said plugboard by rearward pressure on the tip thereof, an actuating member positioned within said shell and operatively engaging said latch member, a terminal portion axially slidably mounted within said shell and adapted for connection to a wire inserted therein, means joining said actuating member and said terminal portion whereby relative axial movement of said terminal and said shell by means of a pull on a wire connected to said terminal will retract said latch member and permit Iwithdrawal of said plug from the plugboard.

5. A device as described in claim 4 wherein said latch is an integral portion of said shell partially severed along longitudinal lines and said actuating member includes a cam whereby said latch is adapted to be extended radially by said cam to latch the plug into `a receptacle.

6. A device as described in claim 5 rwherein said integral latch .portion comprises a split tip, one part of said tip 4forming a depressed detent nger adapted to engage said actuating cam, and Ianother part forming a straight tip to engage the border of a receptacle to latch the plug against Withdrawal.

7. A device as described in claim 6 wherein said actuating cam comprises a cone shaped -portion on said terminal, having stops at each end adapted to engage the detent nger, a sleeve joining said cam to said conducting wire within said plug.

8. A device as described in claim 4 wherein said latch comprises a spring having a cam section thereon adapted to project through said opening in said shell to engage said plugboard, said actuating member including a slide portion extending transversely of the axis of said shell adjacent said cam section, said slide being movable toward said section yto cam down the projecting portion of said spring whereby to release said plug from said plugboard.

9. A device as described in claim 8 wherein said latch and cam are keyed to the plug shell whereby accidental disassembly is prevented.

References Cited in the ile of this patent UNITED STATES PATENTS Number Name Date 2,336,385 Batcheller Dec. rI, 1943 2,405,400 Buttereld Aug. 6, 1946 2,427,297 Modrey Sept. 9, 1947 2,496,732 rLyman Feb. 7, 1950 2,498,743 Theriault Feb. 28, 1950 2,521,516 Heidman Sept. 5, 1950 2,624,774 Cunningham Jan. 6, 1953 FOREIGN PATENTS Number Country Date 480,469 Great Britain Feb. 23, 1938

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