WO1997010627A1

WO1997010627A1 - Connector housing with improved latch members

Info

Publication number: WO1997010627A1
Application number: PCT/US1996/014984
Authority: WO
Inventors: Daines Milfred Self
Original assignee: The Whitaker Corporation
Priority date: 1995-09-12
Filing date: 1996-09-12
Publication date: 1997-03-20

Abstract

The invention comprises an electrical connector having a housing with a side surface (23, 25). A latch arm (26) is disposed along the side surface, the latch arm has a joint (34) securing the latch arm to the side surface. A groove (32) extends from the joint to a free end of the latch arm to receive a second latch arm on a matable connector. A stress rib (38) extends from a side wall of the joint to the side surface of the housing. Stresses formed during deflection of the latch arm are distributed over the length of the latch arm, through the joint and stress rib.

Description

CONNECTOR HOUSING WITH IMPROVED LATCH MEMBERS

The invention relates to improved latch members for use with an electrical connector housing. In particular, the latch members are configured tc eliminate a hinge having a pivotal axis, thereby minimizing the potential for latch breakage.

Housings for certain electrical connectors are molded from dielectric plastic material and are intended to be secured to mating connector housings when the connectors have been moved together in a mated condition, in which the respective arrays of electrical contacts are mated to complete electrical connections. In some of these connectors, hardware is fastened to the respective housings to secure them together in their mated condition, but it is desirable that the housings have an integral latching means. Integrally molded latch arms are disposed along opposed sides of the housing of one of the connectors and extend forwardly to latchingly engage corresponding latching surfaces of the housing of the other connector, when the connectors are moved together into a mated condition.

Latch arms used for securing connectors together are known in U.S. Pat. No. 4,867,700. The latch arms include rearward portions which are deflectable to unlatch the latch arms when it is desired to separate and unmate the connectors, in which case the latch arms can be said to be hingedly joined to the housing and rotates about a central axis along the hinge joint. Such latch arms are subjected to stress and torque during mating and unmating, especially taking into consideration that the hinge joint is molded of plastic material which can commonly lose strength over time when worked and subjected to temperature cycling as well.

U.S. Pat. No. 5,382,177 discloses a connector with latch arms which are joined to the housing with flexible hinge joints. The hinge joints are "dogbone" shaped and are configured to properly distribute the stresses associated with the latch arms, such that as forces are applied to the latch arms, concentration of stresses will be avoided on the hinge joints. These latch arms are also subjected to stress and torque during mating and unmating and can, over time, loose strength and break.

It is desired to provide latch arms which are designed to resist stress and torque and yet be flexible to allow many cycles of deflection of the latch arm during mating and unmating of the connectors.

The invention comprises an electrical connector, having a housing with a side surface, a mating face, a rearward face, and contact receiving cavities extending from the rearward face through the mating face to receive contacts therein. A latch arm is disposed along the side surface, the latch arm has a joint securing the latch arm to the side surface. A stress rib extends from a side wall of the joint to the side surface of the housing. Stresses formed during deflection of the latch arm are distributed over the length of the latch arm, through the joint and stress rib.

An embodiment of the invention will be described with reference to the accompanying drawings, in which:

Figure 1 is an isometric view of a connector of the present invention;

Figure 2 is a side view of the connector;

Figure 3 is a top view of the connector; Figure 4 is a top view of the connector and a mating connector; and

Figure 5 is a similar view to Figure 4 with the connectors mated.

Referring to Figure l, a preferred form of the connector assembly in accordance with the invention comprises a plug connector 10. The plug connector 10 comprises a block 12 having a mating face 14 and a rearward face 16. Contact silos 18 extend forwardly from the mating face 14. Contact receiving cavities 20 extend longitudinally through the connector 10 from the rearward face 16 through the contact silos 18. The contact receiving cavities 20 receive electrical contacts (not shown) which can be electrically connected to contacts in a mating connector.

The block 12 has upper and lower surfaces 22, 24. The block 12 has side surfaces 23, 25 from which latch arms 26 extend. Each latch arm 26 has a free end 28 with a latch member 30. Along the forwardly facing portion of the latch member 30 is a ramped surface 31. The latch arm 26 has a joint 34 from which the latch arm 26 extends. In the preferred embodiment, the latch arm 26 comprises two separate arms which extend from two separate joints to the free end 28. A groove 32 extends from the joint 34 to the latch member 30 between the separate arms. Along the forwardly facing portion of the free end 28 of the latch member 30 are serrations 36. The serrations form an engaging surface which allows easy manipulation of the latch arm by the finger of the user.

The joint 34 is a basically rectangular body which joins the latch arm 26 with the block 12. Extending rearwardly from each joint is a ramped rib 38. The rib 38 extends downwardly from the side wall 40 of the joint to the side surface 23, 25 of the block 12. The ramped rib is integrally molded with both the joint 34 and the block 12. Each joint has a ramped rib 40 extending rearwardly from the side walls 40.

Figures 4 and 5 show the mating of the plug connector 10 with a matable connector 50. The matable connector has latch arms 52 along either side surface 51, each latch arm 52 has a barbed end 54 with a second ramped surface 53 to engage the latch arm 26 on the plug connector. The mating connector 50 has a mating face 58 and a rearward face 60. Contact receiving cavities extend longitudinally from the mating face 58 to the rearward face 60. Contacts are received in the contact receiving cavities to electrically connect with the contacts in the plug connector 10. When the plug connector and the mating connector 50 are mated, the contact silos 18 are received within the contact receiving cavities of the mating connector 50 and the contacts are brought into electrical contact with each other. During mating of the plug 10 and matable connectors 50, the ramped surface 31 of the latch member 30 engages the second ramped surface 53 and deflects the latch arms 26, outwardly as is indicated by the arrow shown in Figure 4. Upon complete mating, latch members 30 are moved beyond the barbed end 54 such that the latch arm 26 resiles to its initial position and the barbed end 54 is positioned within the groove 32. In this position, shoulder 44 of the latch arms 26 engages shoulder 56 of latch arms 52, as is shown in Fig. 5, to prevent inadvertent delatching caused by stress or vibration when the connectors are in the mated position.

To unlatch the connectors, the free end 28 of the latch arm 26 is pushed outwardly away from the matable connector by the thumb and forefinger of the user, see Fig. 5. The serrated section 36 provides a textured surface which is easily engaged with the finger of the user. Once the latch arms 26 are pushed outwardly, the ramped surface 31 on the latch member 28 engages the barbed end 54 on the latch arm 52. The force of the latch arms 26 pushing towards their natural, undeflected position and the ramped surface 31 operating on the second ramped surface 53 acts to push the matable connector 50 away from the plug connector 10.

In order to disconnect other latching arms on other connectors, it is necessary to push the latch arm away from the matable connector and hold it in that position while the connectors are being moved apart from each other. The improvement in the latch arms in the current connector only requires that the latch arms be pushed outwardly initially, it is not necessary to continue to hold the latch arms in this position while the connectors are being moved apart, the ramped surfaces on the latch arms accomplish this task themselves.

The deflection of the latch arm 26 is a beam deflection. The stresses from deflection are distributed along the length of the latch arm and through the joint. The ramped rib provides additional distribution of the stresses from beam deflection. The latch arm disclosed in U.S. Pat. No. 5,382,177 has a hinge joint such that the latch arm rotates around a central axis. Over time, the stresses in the hinge joint can cause the hinge joint to become weakened and to fail. The use of a beam deflection rather than rotation about a hinge joint provides better distribution of the stresses and therefore provides a latch arm which can withstand mating and unmating of the connectors for a longer period of time.

In connectors of this type, the joint 34 is subjected to various forces including pull-out forces and displacement forces. The pull-out forces occur when the plug connector 10 is pulled away from the mating connector 50 without disengaging the latch arms. These pull-out forces have an axial component and a rotational component associated therewith. The displacement forces are the forces associated with the rotation of the latch arms from the mating position to the unmating position. Both the pull-out and displacement forces are transmitted to the joint causing the joint to be stressed. As each force is different, the stress distribution of the joint varies for each force. Consequently, the optimum design for the joint must be one which allows for flexibility of the joint and which can accommodate the various stress distributions without failure. For the connector illustrated, this optimum design is described above.

The connector and latch arm of the present invention and many of its attendant advantages will be understood from the foregoing description. It is apparent that various changes may be made in the form, construction, and arrangement of parts thereof without departing from the spirit or scope of the invention, or sacrificing all of its material advantages.

Claims

We Claim :

1. An electrical connector comprising a housing having a side surface (23,25), a mating face (14), a rearward face (16) , and contact receiving cavities (20) extending from the rearward face through the mating face to receive contacts therein, a latch arm (26) disposed along the side surface, the latch arm having a joint (34) securing the latch arm to the side surface, the latch arm extending from the joint to a free end (28) , characterized in that a stress rib (38) extends from a side wall (40) of the joint to the side surface of the housing (23,25), wherein stresses formed during deflection of the latch arm are distributed over the length of the latch arm, through the joint and stress rib.

2. The electrical connector of claim l, wherein the latch arm (26) comprises two separated arms with a groove (32) therebetween, the free end includes a latch member (30) with a serrated surface along a forwardly facing surface.

3. The electrical connector of claim 1, wherein the joint (34) comprises a substantially rectangular shape having a side wall (40) and the stress rib is ramped from the side wall to the side surface of the housing.

4. The electrical connector of claim 1, wherein the housing further comprises contact silos (18) extending forwardly from the mating face (14) , the contact silos having polarizing sides to ensure proper orientation during mating with the matable connector, the contact receiving cavities (20) extending from the rearward face, through the contact silos.

5. The electrical connector of claim 4, wherein the latch arm comprises two separated arms with the groove (32) therebetween, the free end (28) includes a latch (30) member with a serrated surface along a forwardly facing surface.

6. The electrical connector of claim 5, wherein the housing comprises a block (12) , the contact silos (18) extend forwardly from the block, the latch arm (26) extending forwardly from the side walls such that the latch arm is substantially parallel with the contact silos.

7. The electrical connector of claim 6, wherein the stress rib (30) is directed substantially parallel with the latch arm, the rib extending rearwardly from the joint (34) .

8. The electrical connector of claim 1, wherein the latch arm (26) has a latch member (30) on an end remote from the joint, the latch member has a shoulder (44) to engage a matable connector, the latch arm has a ramped surface which will act to deflect the latch arm during mating with the matable connector and which will serve to keep the latch arm deflected and to guide the connectors apart during unmating.