WO1998031076A9

WO1998031076A9 - Contact latch member and electrical connector using the same

Info

Publication number: WO1998031076A9
Application number: PCT/US1998/003346
Authority: WO
Filing date: 1998-01-06
Publication date: 1998-12-23

Abstract

The present invention provides a metal contact latch member which allows the stable and secure fastening of contacts in a compact, high-density electrical connector, and an electrical connector using the contact latch member. Attachment slots (44a, 44b) are provided in an insulating housing (40) which extend parallel to contact-receiving cavities (41a, 41b) extending between an engaging surface (42) and rear surface (43) of the insulating housing (40). Separate metal contact latch members (30) are fastened by press-fitting in the attachment slots (44a, 44b). Each contact latch member (30) has a fastening section (31), a transition section (33), a flexible flat plate (35), and a contact-engaging projection (36) which is cut out and bent from a side edge of the flexible flat plate (35).

Description

CONTACT LATCH MEMBER AND ELECTRICAL CONNECTOR USING THE SAME

The present invention relates an electrical connector, and specifically relates to a latch member which latches electrical contacts inside a housing, and an electrical connector using the latch member.

Electrical connectors are generally constructed from an insulating housing and one or more electrical contacts or terminals which are held in contact-receiving cavities inside the housing.

Means for holding or fastening the contacts inside the contact-receiving cavities of the housing include contact lances and housing lances. In the former type, lances are formed on the contacts themselves; in the latter type, flexible lances are generally formed as integral beams inside the contact-receiving cavities at the time of molding.

These contact lances and housing lances have respective advantages and disadvantages. Specifically, lances of the former type generally make it possible to hold the contacts securely within the contact-receiving cavities and with a large holding force. However, the contacts may become entangled with each other or with the wires terminated to the contacts; as a result, not only are the handling characteristics poor, but the contact lances may exceed their flexible limit and be deformed so that the contact-holding force is absorbed by the contact lances, or that the contact lances become unable to hold the contacts. In lances of the latter type, on the other hand, since the lances are formed inside the contact- receiving cavities as integral parts of the housing, there is little danger that the lances will be deformed or damaged as a result of being subjected to external forces during handling; however, it is difficult to confirm whether or not the lances have been correctly formed at the time of molding. Especially in the case of compact high-density electrical connectors, the housing lances themselves are also small; accordingly, normal lance formation is difficult, and the holding force is small.

Conventionally, various improvements have been tried in an attempt to avoid such drawbacks. In lances of the former type, improvements have been proposed in which protrusion of the contact lances to the outside of the contacts is suppressed, or deformation or entanglement with other contacts or wires is prevented by forming lance-protecting ribs thereon. In lances of the latter type, for example, the housing may be formed as a two-part structure in which the housing lances are formed separately from the main body of the housing as disclosed in Japanese Patent Application No. 60-748, with the housing being assembled and the contacts inserted in the contact-receiving cavities after it has been confirmed prior to the insertion of the contacts that the housing lances have been properly formed.

In order to satisfy both requirements in terms of handling and assembly of the contacts and in terms of compact size, lances that are formed on the housing side are preferable to contact lances. Here, therefore, an electrical connector using housing lances or latches will be described. Figures 8A and 8B show a conventional connector 10 using metal lances which are separate from the housing. Connector 10 is disclosed in Japanese Utility Model Application No. 3-37768. Contacts 12, which have projections 12a on their bottom surfaces, are inserted into the contact-receiving cavities 14 of the housing 11 of connector 10. Metal contact latch members 16 of Figure 8B are further inserted into the contact-receiving cavities 14 along bottom surfaces thereof as shown in Figure 8A. In contact latch members 16, a portion of main body 16a is cut out and raised to form lance 17, which is caused to engage the projection 12a on the corresponding contact 12, so that the contact 12 is prevented from slipping out. Furthermore, the contacts of a mating connector (not shown) are inserted into the contacts 12 via openings 13 in the engaging surface of the housing 11 so that an electrical connection is established.

Figure 9 also shows a conventional double-lock connector 20, which is disclosed in Japanese Utility Model Application No. 61-161975. In connector 20, lances 22, which are made of a shaped-memory alloy, are installed in the contact-receiving cavities 14 of the housing 10A along with housing lances 18, which engage with the contacts 12A, and lances 22 engage with projections 26, which protrude from the outside surfaces of the contacts 12A so that the contacts 12A are prevented from slipping out. In the case of electrical connectors using conventional housing lances or separate metal lances described above, sufficient strength cannot be obtained, or use is difficult, when such lances are used in compact high-density electrical connectors. Furthermore, the assembly characteristics are poor, and the contacts cannot be replaced once they have been inserted in the contact- receiving cavities.

Accordingly, one feature of the present invention is to provide a contact latch member which makes it possible to hold compact high-density contacts with sufficient strength, and an electrical connector using the contact latch member.

Another feature of the present invention is to provide an electrical connector using separate latches, which has good assembly characteristics, and which allows the removal of contacts when necessary.

Furthermore, another feature of the present invention is to provide a novel metal contact latch member which makes it possible to latch contacts with sufficient strength in contact-receiving cavities even in cases where the contact latch member is extremely small. In order to solve the problems described above and - achieve the above features, the contact latch member of the present invention is a member which is inserted into contact-receiving cavities of a connector housing, and which latches electrical contacts that are inserted into the contact-receiving cavities, the contact latch member is a single metal member which has a fastening section formed in the vicinity of one end of the contact latch member, which is inserted into and maintained in an attachment slot extending parallel to each contact- receiving cavity, a transition section oriented substantially perpendicular to a direction of length of the contact latch member, a latching section having a substantially flexible flat plate which forms a wall surface of the corresponding contact-receiving cavity, and a contact-engaging projection on the flexible flat plate, and which is oriented substantially perpendicular to a plane of the flexible flat plate.

Furthermore, the contact latch member of the present invention is a member formed from a single metal plate which has a fastening section which is folded back so that it has a double thickness, a latching section in the form of a flexible flat plate which extends in the form of a cantilever beam with respect to the fastening section and a contact-engaging projection which is formed by cutting out and bending one edge of the flexible flat plate and which extends vertically with respect to the flexible flat plate.

Moreover, the contact latch member of the present invention engages with electrical contacts inserted into contact-receiving cavities of an electrical connector housing, and latches the contacts within the contact- receiving cavities and a fastening section which is fastened in place by press-fitting in an attachment slot of the housing. The fastening section preferably has a first plate - which is formed by folding back the metal plate and which includes a press-fitting projection, and a second plate which overlaps with the first plate, extends to the vicinity of a latching section, and forms a pressing shoulder for press-fitting at a tip end of the second plate. The pressing shoulder is ordinarily offset from the latching section in the direction of height thereof.

The fastening section and the latching section are preferably connected by a transition section which extends at an inclination.

The contact-engaging projection is preferably formed on one side edge of the flexible flat section, and a reinforcing portion is formed by folding back and overlapping the flexible flat section on a opposite side from the contact-engaging projection.

Furthermore, the electrical connector housing which uses the contact latch member of the present invention is equipped with one or more contact-receiving cavities and attachment slots formed adjacent the contact-receiving cavities, and one or more metal contact latch members, each of which has a fastening section which is inserted into and held in the corresponding attachment slot of the housing, a latching section in the form of a flexible flat plate which extends in the form of a cantilever beam from the fastening section to the vicinity of an engaging surface of the housing, and a contact-engaging projection which is formed by cutting out and bending one edge of the flexible flat plate, and which is caused to protrude into the corresponding contact-receiving cavity, and the contacts inserted into the respective contact-receiving cavities are held by the contact latch members.

A metal contact latch member for use in a contact- receiving cavity of an insulating housing for latching an electrical contact in the contact-receiving cavity comprises a flat plate disposed along the contact- receiving cavity and having a contact-engaging projection for engaging the electrical contact to maintain the electrical contact in the contact-receiving cavity, wherein a fastening section is connected to the flat plate for engagement within an attachment slot of the insulating housing, and a press-fitting surface is disposed adjacent the flat plate for engagement by a tool for press fitting the fastening section in the attachment slot.

Embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which:

Figure 1A is a plan view of contact latch members connected by a carrier strip.

Figured IB is an enlarged view of an area indicated by box B in Figure 1A.

Figure 1C is a side view looking upward from the bottom of Figure 1A.

Figure 2 is a cross-sectional view of an electrical connector in which the contact latch members of Figure 1A- 1C are positioned along contact-receiving cavities thereof.

Figure 3A is a front view of the connector housing shown in Figure 2.

Figure 3B is a plan view of the connector housing shown in Figure 2.

Figures 4A and 4B are perspective views of an embodiment of the contact latch member.

Figure 5A is a side view of the contact latch member shown in Figures 4A and 4B. Figure 5B is a cross-sectional view taken along line 5B-5B of Figure 5A.

Figure 6 is a cross-sectional view of an embodiment of the electrical connector in which the contact latch members of Figures 4A-5B are positioned along contact- receiving cavities thereof. Figure 7A is a perspective view of a conventional - contact latch member shown in Figures 8A and 8B.

Figure 7B is a side view of Figure 7A.

Figure 7C is a perspective view of a latching section of the contact latch member shown in Figures 1A-1C.

Figure 7D is a side view of Figure 7C.

Figure 8A is a cross-sectional view of a conventional electrical connector using a separate contact latch member shown in Figures 7A, 7B. Figure 8B is a perspective view of the conventional contact latch members connected to a carrier strip that are used in the conventional electrical connector of Figure 8A.

Figure 9 is a cross-sectional view of another conventional electrical connector using another known separate contact latch member.

Contact latch member 30 of the present invention will be described with reference to Figures 1A-1C, which are formed by stamping and forming a metal plate made of a copper alloy. Like conventional electrical connector contacts, the contact latch members 30 are connected to each other by a carrier strip CS. Numerous contact latch members 30 of this type are generally wound on a reel and supplied to an electrical connector assembling machine by an assembly feeder. Immediately prior to assembly, the carrier strip CS is cut by a shearing blade, so that individual contact latch members 30 are provided. Furthermore, the assembly of the contact latch members 30 to the electrical connector will be described later with reference to Figure 2.

The contact latch member 30 will be described in detail with reference to Figures 1A-1C. As shown most clearly in Figure 1C, the contact latch member constructed according to a preferred embodiment of the present invention has a fastening section 31 at one end (the right end) which is folded back into a double thickness including overlapping plates 31a, 31b, a transition section 33, which is oriented substantially perpendicular to the direction of length at the opposite end of the fastening section 31 from the tip end 32 of the fastening section 31, a latching section 35 in the form of a flexible flat plate, which extends in the direction of length from the transition section 33 toward the other end 34 of the contact latch member, and contact-engaging projection 36, which is formed by forming a slit running from one edge toward the other edge in the central portion of the flexible flat plate 35, and bending the cut-out portion so that this portion is substantially perpendicular to the plane of the flexible flat plate 35. As is clear from Figure 1C, the contact-engaging edge 37 at the rear end of the contact-engaging projection 36 forms an angle of less than 90 degrees with respect to the plane of the flexible flat plate, and is thus formed so that contact-engaging edge 37 securely engages with the contact. Furthermore, barbs 38, which are substantially wave-shaped, are formed on the outer edges of the fastening section 31, and the barbs 38 are press fitted in contact-attachment slots which extend parallel to the contact-receiving cavities of the connector housing (which will be described later) . Furthermore, the tip end 32 of the fastening section 31 of the contact latch member 30 is rounded, so that insertion into the contact-attachment opening is facilitated.

As will be clear from the description below, the transition section 33 of each contact latch member 30 is utilized as a pressing surface during press-fitting of the contact latch member 30 in the contact-attachment slot of the connector housing. Furthermore, the flexible flat plate 35 acts as a cantilever beam with respect to the fastening section 31, thus endowing the contact latch member 30 with the required flexibility. As a result of using such a specified shape, it is possible not only to fasten the contact latch member 30 in the contact- attachment slot of the connector housing by press-fitting, but also to achieve fastening of the contacts within the contact-receiving cavities, and to remove erroneously inserted or damaged contacts. Details of these features will be described later.

Next, an electrical connector using the contact latch members shown in Figures 1A-1C will be described with reference to Figure 2. Figure 2 is a longitudinal cross- sectional view of a preferred example of electrical connector 100 of the present invention. In the electrical connector 100 shown in Figure 2, upper and lower contact- receiving cavities 41a and 41b are formed inside an insulating housing 40; furthermore, a latch arm 50 is integrally molded on the upper surface of the connector housing. Since latch arm 50 has a universally known shape, details of the construction of the latch arm 50 will be omitted here. Briefly, however, latch arm 50 has a fixed end 51 which is fastened to the insulating housing 40 on the side of the engaging surface 42, an operating member

53 at an opposite free end 52, and a latch-engaging member 54, which is formed on the upper surface of the central portion of the latch arm 50. A latch-engaging surface (not shown) on a mating connector effects a latch engagement with latch-engaging member 54, especially with a shoulder 55 on a rear surface thereof.

As is clear from Figure 2, contact-attachment slots 44a and 44b for the contact latch members 30, which extend parallel to the contact-receiving cavities 41a and 41b of the electrical connector 100 are formed above central portions of the respective cavities 41a and 41b. Furthermore, stop surfaces 45a and 45b, which stop the contacts (not shown) inserted from the rear surface 43, and contact guide openings 46a and 46b for the contacts of the mating connector are formed in the vicinity of the engaging surface 42. The contacts are inserted into the respective contact-receiving cavities 41a and 41b from the rear surface 43 of the insulating housing 40. Here, it should be noted that since the contact-receiving cavities 41a and 41b have relatively simple shapes in which conventional housing lances are not formed, manufacture of the connector housing is easy and inexpensive.

Furthermore, prior to the insertion of the contacts into the contact-receiving cavities 41a and 41b, the contact latch members 30 are fastened by press-fitting above the respective contact-receiving cavities 41a and 41b. As was described above, this press-fitting is accomplished by pressing against the transition sections 33 of the contact latch members 30 with a jig. Here, the pressing jig is inserted together with the contact latch members 30 into the openings 47a and 47b for the contact latch members 30, which are formed above the contact- receiving cavities 41a and 41b, and which communicate therewith. As is clear from Figure 2, the openings 47a, 47b communicate with the contact-receiving cavities 41a, 41b on the side of the engaging surface 42, so that when the contact latch members 30 are completely fastened by press- fitting, the contact-receiving cavities 41a, 41b and the openings 47a, 47b are separated by the flexible flat plates 35 of the contact latch members 30. As a result, the contact-engaging projections 36 protrude into the interiors of the contact-receiving cavities 41a and 41b. This state is clearly illustrated in Figure 2. Contact- engaging sections 36 engage with engaging shoulders or with edge portions of openings formed in box-type receptacle contacts when inserted into the contact- receiving cavities.

As shown in Figure 2, after the contact latch members 30 have been completely fastened by press-fitting in the attachment openings 44a and 44b through the openings 47a, 47b extending parallel to the contact-receiving cavities - 41a and 41b in the insulating housing 40, contacts are then inserted into the contact-receiving cavities 41a and 41b from the rear surface 43 of the insulating housing 40. When the contacts are inserted, the upper portions of the contacts engage the contact-engaging projections 36; however, since an acutely-angled taper is formed on the rear surfaces of the contact-engaging projections 36, the flexible flat plates 35 of the contact latch members bend upward so that the contacts can be inserted relatively smoothly. On the other hand, when the contacts are completely inserted into the contact-receiving cavities 41a, 41b, the contact-engaging projections 36 are aligned with the openings of the contacts, so that the flexible flat plates 35 return to the normal horizontal state as a result of the flexibility of the flat plates 35. Consequently, the contacts are fastened inside the contact-receiving cavities 41a, 41b of the insulating housing 40. Specifically, the respective contacts are prevented from moving forward toward the engaging surface

42 by the stop surfaces 45a, 45b of the insulating housing 40, and are prevented from moving toward the rear surface

43 by the engagement between the contact-engaging projections 36 of the contact latch members 30 and the shoulders of the contacts. As a result, the contacts are securely latched in prescribed positions in the contact- receiving cavities 41a, 41b.

Furthermore, the contacts inserted into the contact- receiving cavities 41a, 41b generally terminate prescribed wires. Accordingly, even if the contacts are identical, it is necessary that the respective contacts be inserted into specific predetermined contact-receiving cavities 41a, 41b of the insulating housing 40. In some cases, it may be necessary to replace contacts which have already been inserted and fastened in place. In order to satisfy such requirements, it is necessary to design the connector so that contacts, which have already been inserted and latched in place, can be unlatched and removed from the contact-receiving cavities of the insulating housing 40 if necessary. Accordingly, it should be noted that the free end of the flexible flat plate 35 of each contact latch member 30 is spaced back slightly from the engaging surface 42 of the insulating housing 40, and that a small space 48 is formed beneath the free end thereof.

In order to remove a contact which has already been inserted and latched in place, a small flat-blade screw driver is inserted into the space 48 between one of the openings 47a, 47b and one of the contact-receiving cavities 41a, 41b, the free end of the flexible flat plate 35 is lifted upward into recesses 49a, 49b of openings 47a, 47b so that the engagement between the contact- engaging projection 36 and the contact is released. The contact is then pulled to the rear. In this way, any desired contact can be removed from the corresponding contact-receiving cavity of the insulating housing 40. Figures 3A and 3B are respectively a view of the electrical connector 100 (shown in Figure 2) from the engaging surface, and a plan view of the electrical connector 100. Except for the shape of the engaging surface, such an electrical connector 100 resembles a connector which is universally known for use in automobiles; accordingly, a detailed description will be omitted.

Figures 4A, 4B and 5A, 5B illustrate an embodiment of contact latch member 230 of the present invention. The contact latch member 230 has a press-fitting fastening section 231, and a flexible flat plate 235 which includes a contact-engaging projection 236 similar to the contact- engaging projection 36 (see Figure 1C) . As shown, the press-fitting fastening section 231 and the flexible flat plate 235 are integrally connected by a transition section 233 which extends at an inclined angle. The press-fitting fastening section 231 is formed by folding back a metal plate, and has a first plate 206 which includes a press-fitting portion 238 having wave- shaped barbs, and a second plate 207 which overlaps with the first plate 206 and extends to a point in the vicinity of the flexible flat plate 235 forming a shoulder 205 at the tip end. The second plate 207 has a narrower width than the first plate 206. The first plate 206 and second plate 207 overlap and are positioned via a substantially U-shaped end 203 so that a gap is formed between the two plates. The shoulder 205 of the second plate 207 is used as a pressing shoulder when the contact latch member 230 is press-fitted inside insulating housing 240 as will be described later. As shown in Figures 4A, 4B and 5A, the end portion 202 of the second plate 207 in the vicinity of the shoulder 205 is offset in the direction of height toward the first plate 206 from the remaining portion of the second plate 207. Since the shoulder 205 is positioned at a height that is intermediate between the first plate 206 and second plate 207, the contact latch member 230 can be smoothly inserted and fastened in place by being pushed into the interior of the insulating housing 240. It should be noted that the end portion 202 is ordinarily shifted in the direction of height with respect to the flexible flat plate 235.

The contact-engaging projection 236, which is formed on the flexible flat plate 235 in a position close to the transition section 233 is also formed by folding the side edge of the metal plate back along the direction of length. As in the case of the contact-engaging projection 36 (see Figure 1C) , the edge 237, which engages with the contact (not shown) , forms an acute angle with the plane of the flexible flat plate 235. Furthermore, a reinforcing member 201, which is formed by folding back and overlapping the flexible flat plate on the opposite side from the contact-engaging projection 236, is formed on the opposite side edge of the flexible flat plate 235 in a position facing the position of the contact-engaging projection 236. The reinforcing member 201 is used to prevent deformation of the flexible flat plate 235 when the contact engaged with the contact-engaging projection 236 is subjected to a substantial tensile force. It should be noted that the reinforcing member 201 is formed along a length which exceeds the total length of the contact- engaging projection 236. The flexible flat plate 235 includes an extended portion 208, which is further extended from the vicinity of the contact-engaging projection 236. This extended portion 208 is constructed so that it becomes narrower in width toward the free end 209. The action and effect of the extended portion 208 will be described later.

Like the contact latch members 30 (see Figure 2), the contact latch members 230 in the connector 300 shown in Figure 6 are positioned within openings 247a, 247b which are formed along the contact-receiving cavities 241a and 241b of the insulating housing 240, and which communicate with the upper sides of the contact-receiving cavities 241a and 241b. The contact latch members 230 are respectively inserted via openings 247a and 247b, and the press-fitting fastening sections 231 are fastened in place by being press-fitted in contact-attachment slots 244a and 244b. The substantially U-shaped end 203 of the press- fitting fastening section 231 engages with end walls 212a and 212b inside the attachment slots 244a and 244b. In this case, the flexible flat plates 235 extend along the contact-receiving cavities 241a and 241b and form upper walls of the contact-receiving cavities 241a and 241b. Furthermore, the free ends 209 of the extended portions 208 reach the vicinity of the openings 247a and 247b, and terminate inside the insulating housing 240. Moreover, since the extended portions 208 are formed so that the extended portions 208 become narrower in width toward the free ends 209 (as was described above) , there is no danger that the extended portions 208 will interfere with the side surfaces of the openings 211a and 211b, even if the orientation of the press-fitting of the press-fitting fastening sections 231 deviates slightly from the prescribed orientation.

As in the case of the connector 100 containing the contact latch members 30, the flexible flat plates 235 of the contact latch members 230 are deflected upward inside the recesses 211a, 211b of openings 247a, 247b when contacts (not shown) are accommodated in the contact- receiving cavities 241a and 241b. In order to avoid interference with the respective extended portions 208, the openings 247a, 247b have recessed step surfaces 212a and 212b so that spaces for flexing are provided.

Furthermore, since the portions of the openings 247a, 247b that communicate with the contact-receiving cavities 241a and 241b are formed with a narrower width than the flexible flat plates 235 (although details of this are not shown), there is no bending of the flexible flat plates 235 into the contact-receiving cavities 241a and 241b.

When the contacts (not shown) are completely accommodated in the contact-receiving cavities 241a and 241b, the contact latch members 230 return to the state shown in Figure 6 from a flexed state. In cases where a tensile force is applied to the contacts, a force is applied to the contact latch members 230 in the direction indicated by arrow F in Figure 6; in such a case, however, since the substantially U-shaped ends 203 of the press- fitting fastening sections 231 are in engagement with the end walls 212a and 212b inside the contact-attachment slots 244a and 244b, and since the areas around the contact-engaging projections 236 are reinforced by the reinforcing members 201, the contacts can be sufficiently held against a substantial tensile force with no deformation of the contact latch members 230. Especially in cases where the shoulder 205 is formed in close proximity to the reinforcing member 201 in each contact latch member 230, the reinforcing members 201 can also engage with the shoulders 205 when a tensile force is applied to the contacts.

Furthermore, in the connector 300 as in the connector 100, spaces 248 are formed beneath the free ends 209 of the contact latch members 230. Accordingly, in cases where contacts which have been inserted and fastened in place are to be removed, a tool such as a screw driver is inserted into the spaces 248, and the flexible flat plates 235 are lifted; as a result, the engagement between the contact latch members 230 and the contacts can be released. Furthermore, the areas in the vicinity of the extended portions 208 can also be used to test the electrical continuity of the contacts. Specifically, when the contacts are accommodated in the prescribed positions inside the insulating housing 240 of the connector 300, there is also electrical continuity between the contacts and the metal contact holding members 230. Accordingly, the electrical continuity of the contacts can be tested merely by inserting a continuity test probe into the openings 247a and 247b or spaces 248, and causing the probe to engage the contact latch members 230 in the vicinity of the free ends thereof. Furthermore, since the probe does not come into direct contact with the contacts, there is no danger that the contacts will be damaged during such an electrical continuity test.

Next, the differences between the contact latch member 30 of the present invention and a conventionally proposed contact holding member will be described in some detail with reference to Figures 7A and 7B. In conventional contact latch member 16 of Figures 8A, 8B, the contact-engaging projection 17 is formed by forming a U-shaped slit in approximately the center of the flat plate, and raising the resulting cut portion. Accordingly, the width of the contact latch member 16 must be several- millimeters in order to obtain the required strength and holding force. This dimension is far larger than that stipulated by the contact density required in recent electrical connectors for use in automobiles. In other words, conventional contact latch member 16 cannot be used in the compact, high-density electrical connector that is the target of the present invention. Furthermore, since the contact-engaging projection 17 is cut out and raised at an inclined angle, the engaging end surface unavoidably has an angle a (corresponding to the angle by which the cut-out is raised) oriented rearward with respect to the transverse direction of the plane of the contact latch member 16. This angle cannot be freely set, and in particular cannot be inclined forward; accordingly, the engaging force with the contact that is engaged is weak. Meanwhile, Figures 7C, 7D show a representation of the contact latch member 30 of the present invention shown in Figures 1A-1C. As is clear from Figures 7C, 7D, the angle of the engaging edge 37 of the contact-engaging projection 36 can be set at any desired angle b which is inclined forward with respect to the transverse line of the plane of the flexible flat plate 35. Furthermore, the contact-engaging projection 36 has a sufficiently long base so that the contact-engaging projection 36 will not buckle even if a large pulling force is applied to the contact. Accordingly, it will be seen that a large holding force can be obtained, and that the engagement with the contact can be made more secure, i. e., more highly reliable, as a result of the forward-oriented angle described above. Moreover, it is clear that the contact latch member 230 also has the same effect.

Embodiments of the contact latch member of the present invention and an electrical connector using the contact latch member have been described above with reference to the attached drawings. However, it will be understood by a person skilled in the art that these embodiments merely indicate examples of the present invention, and that various modifications and alterations are possible in accordance with specified uses. Accordingly, the present invention also includes such modifications and alterations.

As is clear from the above description, the contact latch member of the present invention makes it possible to hold small contacts in a compact, high-density electrical connector with sufficient strength; the reliability and stability of this holding action are good, and contacts can easily be fastened in place by press-fitting the contact latch member in prescribed positions in the insulating housing. Furthermore, compared to conventional contact latch members, the contact latch member of the present invention also possesses the following conspicuous merit: i. e., the contact latch member of the present invention can easily be manufactured by stamping and forming a metal plate. Furthermore, in an electrical connector using contact latch members constructed according to the present invention, press-fitting of the contact latch members into the housing is easy, and contacts can easily be removed when necessary. Such special features cannot be obtained using the conventional technique illustrated in Figures 8 and 9. Thus, the electrical connector of the present invention is suitable for use as an automobile electrical connector which is subjected to large vibrations, impacts and thermal stresses. Furthermore, in the contact latch member of the present invention, a fastening section, which is formed by stamping and forming a metal plate, and which is fastened in place by press-fitting into an attachment slot in the housing, and a flexible flat plate including a contact- engaging projection having an edge which is formed by cutting out and bending a portion of the metal plate, are connected into an integral unit in the direction of length while being offset in the direction of height. Accordingly, the fastening section and flexible flat plate can be functionally separated, so that there is no danger of damage to the flexible flat plate when the contact latch member is press-fitted into the housing. Furthermore, the space in which a tool used to press the fastening section is placed during press-fitting can be used as a flexing space for the flexible flat plate; accordingly, the space required for the installation of the contact latch member is relatively small. Moreover, since the flexible flat plate is formed with a considerable length, the removal of contacts which is accomplished by inserting a tool from outside the housing and releasing the hold on the contacts is facilitated. Furthermore, since an extended portion of the flexible flat plate can also be utilized as a contact surface which contacts a probe used for electrical continuity testing of the contacts, such testing is also facilitated; at the same time, any danger that the contacts will be damaged during such testing is eliminated.

Claims

1. A metal contact latch member (30, 230) for use in a contact-receiving cavity (41, 241) of an insulating housing (40, 240) for latching an electrical contact in the contact-receiving cavity comprising a flat plate (35, 235) disposed along the contact-receiving cavity and having a contact-engaging projection (36, 236) for engaging the electrical contact to maintain the electrical contact in the contact-receiving cavity, characterized in that a fastening section (31, 231) is connected to the flat plate (35, 235) for engagement within an attachment slot (44a, 244a) of the insulating housing, and a press- fitting surface (33, 205) is disposed adjacent the flat plate (35, 235) for engagement by a tool for press fitting the fastening section (31, 231) in the attachment slot.

2. A metal contact latch member as claimed in claim 1, wherein said flat plate (35, 235) is flexible and is extendible along a recess (47a, 211a) of the contact- receiving cavity (41, 241) .

3. A metal contact latch member as claimed in claims 1 and 2, wherein the fastening section (32, 231) has overlapping plates (31a, 31b; 206, 207) connected together by a rounded end (32, 203) .

4. A metal contact latch member as claimed in claim 3, wherein wave-shaped barbs (38, 238) are provided along edges of one of the overlapping plates.

5. A metal contact latch member as claimed in claim 2, wherein the contact-engaging projection (36, 236) extends downwardly from an edge of said flexible flat plate (35, 235)

6. A metal contact latch member as claimed in claim 5, wherein a reinforcing member (201) extends from an opposite edge of said flexible flat plate (235) across said flexible flat plate.

7. A metal contact latch member as claimed in claim 3, wherein said press-fitting surface (205) is located at an end of one of the overlapping plates (206, 207) .

8. A metal contact latch member as claimed in claim 1, wherein said press-fitting surface (33) extends perpendicular with respect to said flat plate (35) and said fastening section (31) .

9. An electrical connector comprising an insulating housing (40, 240) having contact-receiving cavities (41, 241) for receiving electrical contacts therein, metal contact latch members (30, 230) extending along the contact-receiving cavities and having contact-engaging projections (36, 236) for engaging the electrical contacts when inserted into the contact-receiving cavities to maintain the electrical contacts therein, characterized in that said insulating housing (40, 240) having contact- attachment slots (44a, 4b; 244a 244b) along the contact- receiving cavities in which fastening sections (31, 231) of said contact latch members are disposed, said contact- engaging projections (36, 236) extending outwardly from flexible flat plates (32, 231) into said contact-receiving cavities.

10. An electrical connector as claimed in claim 9, wherein said contact-receiving cavities (41, 241) have recesses (47a, 47b; 211a, 211b) along which said flexible flat plates (32, 231) extend.