Connector

This invention relates to a connector for establishing an electrical connection between male contacts and female contacts, and in particular to a connector having a molded connector housing which receives contact terminals which serve as female contacts.

In the connector as mentioned above, the contact terminals are inserted into and held in place in corresponding insertion holes which are formed in the connector housing. It is therefore necessary to provide means for retaining the contact terminals in the corresponding insertion holes so as to prevent the contact terminals from coming out from the insertion holes.

There is known a connector having a connector housing which is provided with stepped portions located in the insertion holes, so that elastic projections (lances) formed on the contact terminals are engaged by the stepped portions so as to prevent the contact terminals from coming out of the corresponding insertion holes. However, in this type of a connector, there is a strong possibility that the lances may be broken or deformed during the operation of the connector, resulting in the separation of the contact terminals from the corresponding insertion holes while the connector is in use.

In order to solve the problem of the lances being broken or deformed during the operation of the connector, there has been proposed a connector housing which is itself provided with abutment members, in place of the lances provided on the contact terminals, so that the abutment members engage corresponding recesses which are formed in the contact terminals. However, in the connector hitherto known, since contact areas between the abutment projections of the connector housing and the corresponding contact terminals are small, the abutment projections can be easily broken when the corresponding contact terminals are subjected to a large drawing force. In particular, when the connector is a multi-contact connector type, breakage of only one abutment member requires replacement of the connector by a new one.

The present invention is directed to a type of a connector in which the connector housing is provided with abutment members and the contact terminals are provided with recesses which the abutment members engage.

The object of the present invention is to provide a reliable connector which can hold the contact terminals at a predetermined position in the corresponding insertion holes so that the terminals cannot accidentally come out of the insertion holes, and whereby an electrical connection between the male and female contacts can be reliably ensured.

In order to eliminate the above mentioned drawback, in the present invention large contact areas are provided between the abutment members and the corresponding contact terminals.

According to the present invention, there is provided a connector comprising a molded connector housing including insertion holes which can be formed by using a molding core and which receive female connector elements which are to be inserted therein; and flexible abutment members which are located in the corresponding insertion holes and which are molded integral with the connector housing. The flexible abutment members are provided with separate free ends which provide large contact areas between the flexible abutment members and the corresponding female contact elements which are to be inserted in the insertion holes to prevent the female contact elements from coming out of the corresponding insertion holes. The flexible abutment members are also provided with recessed grooves having inclined surfaces which enable the molding core to be withdrawn from the connector housing to form the insertion holes after the completion of the connector housing.

The invention will be discussed below in detail, with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of a connector housing of a connector, according to the present invention, viewed from behind,

FIG. 2 is a partially broken and enlarged perspective view of the connector housing illustrated in FIG. 1, but viewed from the front,

FIG. 3 is an enlarged perspective view of a flexible abutment arm of the connector housing illustrated in FIG. 2,

FIG. 4 is a sectional side view of a molding device for molding a connector housing of a connector according to the present invention,

FIGS. 5A-5C are sectional side views which illustrate successive steps in a molding process for manufacturing a molded connector housing of a connector according to the present invention,

FIG. 6 is an exploded perspective view of a connector with upper and lower covers, according to the present invention, and

FIG. 7 is a perspective view of a known flexible abutment member according to the prior art.

First, with reference to FIGS. 1 and 2, the connector housing is designated as 1. The connector housing 1 has two series of insertion holes 2 (only one series of insertion holes 2 are illustrated in FIG. 2) in the illustrated embodiment. The number of the series of the insertion holes 2 is not limited to two and may be less or more than two. Each insertion hole 2 has open ends 2a and 2b. Through one of the open ends, for example 2b, is inserted into the insertion hole 2 a contact terminal 7 which forms a female contact. Through the other open end 2a of each insertion hole are inserted corresponding contact pins 10, which form male contacts and which are arranged in correspondence to the arrangement of the insertion holes 2. Each open end 2a is provided with a smaller diameter portion 3.

The connector housing 1 has two series of flexible abutment members 4 which are molded integrally with the connector housing 1. The abutment members 4 have a common base end 4b and separate free ends 4a so that the members 4 can be flexible. The members 4 are arranged corresponding to the insertion holes 2 so that the members 4 form the top walls of the insertion holes 2. The members 4 are separated by partition walls 21 which form the side walls of the insertion holes 2. Each of the members 4 has at its free end 4a an abutment 5 which projects into the corresponding insertion hole 2, and a recessed groove 6.

The contact terminals 7 can be made, for example, by punching and bending metal plates of a conductive material, such as a phosphor bronze. At one end of the terminals 7 are crimped leads 8, having a single wire or a plurality of wires 22. Each of the terminals 7 is provided, at its other end, with a pair of opposed spring contacts 12, only one of which is illustrated in FIG. 2. The pairs of spring contacts 12 can elastically hold therebetween the corresponding contact pins 10 when inserted thus making an electrical connection between the leads 8 and the corresponding contact pins 10. Each of the terminals 7 further comprises an engagement recess 9 into which the abutment 5 of the member 4 can be fitted. Thus, when the abutments 5 of the members 4 are fitted into the corresponding recesses 9 of the terminals 7, the terminals 7 cannot come out of the corresponding insertion holes 2, even under the influence of a large drawing force being applied to the leads 8.

The leads 8 are stripped at their front ends to expose bare wires 22 which are in turn crimped to the terminals 7 to establish an electrical connection between the terminals 7 and the leads 8. The leads 8 are preferably collected to form a cable 24 (FIG. 6).

The contact pins 10 can be formed, for example, by crushing conductive metal rods. They are secured to a molded body 11 (FIG. 2) to provide male connector elements. The female connector elements are provided by the contact terminals 7. When the contact pins 10 of the male connector elements are inserted into the corresponding contact terminals 7 of the female connector elements and are contacted by the spring contacts 12, an electrical connection is established between the female connector elements and male connector elements.

As mentioned above, in the open ends 2a of the insertion holes 2 are provided the smaller diameter portions 3 which are adapted to prevent the front ends of the contact pins 10 from coming into contact with end faces 7a of the contact terminals 7 when the contact pins 10 are inserted into the contact terminals 7. Therefore, a mold core 16 (FIG. 4) for molding insertion holes 2 must be withdrawn therefrom only in one direction, i.e. in the right hand direction as illustrated in FIG. 4, because of the presence of the smaller diameter portions 3. However, the abutments 5 which project into the insertion holes 2 hinder the core 16 from being withdrawn from the insertion holes 2 in this fashion.

In order to make it possible to withdraw the core 16 from the insertion holes 2 which are to be formed by the core 16, the present invention provides the recessed grooves 6, which are formed on the bottom sides of the members 4, adjacent to the abutments 5, as illustrated in FIG. 3. Each of the recessed grooves 6 has an inclined surface 13.

With reference to FIG. 4, the connector housing can be manufactured by filling cavities with a molding material 31 such as an insulation resin (sand-like), said cavities being defined by an upper die 15, a lower die 14 and the core 16. The core 16 has projections 17 which are adapted to form the recessed grooves 6 (FIG. 3) on the bottoms of the flexible members 4 (FIG. 3) which are to be molded. The projections 17 have inclined surfaces 19 corresponding to the inclined surfaces 13 (FIG. 3) of the recessed grooves 6. The upper die 15 has projections 18 which are adapted to form the abutments 5 (FIG. 3) of the flexible members 4 (FIG. 3).

FIGS. 5A-5C illustrate successive steps in withdrawing the core 16, after the upper and lower dies 15 and 14 (FIG. 4) have been removed. When the core 16 is withdrawn from the insertion holes 2, the molded flexible members 4 are flexed upward due to the presence of the inclined surfaces 19 of the core 16. It will be understood that the molded flexible members 4 return to their original positions, due to their flexibility, after the core 16 is withdrawn from the insertion holes 2. Thus, the connector housing 1 having flexible members 4 integral therewith are molded.

According to the present invention, the area A of the free end 4a of each of the flexible members 4, which is hatched by oblique lines in FIG. 3, contributes to contact with the corresponding contact terminals 7 (FIG. 2) to prevent the latter from coming out of the corresponding insertion hole 2 (FIG. 2). That is, the area A extends over the entire width L of the free end 4a, and accordingly is considerably larger than the area B hatched by oblique lines in FIG. 7 which illustrates a flexible member 4' according to the prior art. In FIG. 7, the prior art flexible member 4' has two inclined surfaces 13' on both sides of an abutment 5'. That is, the inclined surfaces 13' extend to the front face of the free end 4a' on both sides of the abutment 5'. This results in a decreased contact area, which is identical to area B, in comparison with area A of the present invention as illustrated in FIG. 3. The flexible member 4' according to the prior art as illustrated in FIG. 7 has the drawback that the abutment 5' can be easily broken or torn because of the small contact area B when a large pressing force is applied to the free end 4a' of the flexible arm 4' by a contact lead (not illustrated) such as the contact terminal 7 of the present invention. By contrast, in the present invention, since large contact areas A (FIG. 3) can be provided between the contact terminals 7 and the corresponding abutments 5 of the flexible members 4, there is no possibility that the abutments 5 might be broken or torn by the contact terminals 7, even when a strong force is applied to the latter. The provision of the recessed grooves 6 having the inclined surfaces 13 makes it possible to provide the abutments 5 having the large contact area A.

The connector housing 1 is preferably protected by a pair of upper and lower insulation covers 41A and 41B, as illustrated in FIG. 6.

The insulation covers 41A and 41B have grooves 42A and 42B which receive the cable 24. The covers 41A and 41B hold the connector housing 1 therebetween and are for example, by machine screws 43 and nuts (not illustrated). Each of the covers 41A and 41B has a U-shaped member 44 and a projection 45. The covers 41A and 41B are assembled in a snap fashion by the engagement of the U-shaped members 44 and the projections 45. In order to prevent the connector housing 1 from being displaced between the upper and lower covers 41A and 41B, the connector housing 1 is provided, on its upper and lower faces, with channels 25 which may be U-shaped in section. Since the covers 41A and 41B are provided, on their inner faces, with ridges 46 (only one of which is illustrated in FIG. 6) which are closely fitted in the corresponding channels 25 of the connector when held between the covers, the flexible arms which might otherwise buckle when they are subject to compression forces in the lengthwise direction by the corresponding contact terminals do not buckle even under the influence of withdrawing forces.