GB1590365A

GB1590365A - Multiple contact assemblies and method of producing them

Info

Publication number: GB1590365A
Application number: GB16373/78A
Authority: GB
Original assignee: Bunker Ramo Corp
Current assignee: Bunker Ramo Corp
Priority date: 1977-04-29
Filing date: 1978-04-25
Publication date: 1981-06-03
Also published as: JPS6134232B2; DE2719262C2; DE2719262A1; FR2389255B1; CA1091319A; FR2389255A1; JPS53149689A

Description

(54) MULTIPLE CONTACT ASSEMBLIES AND METHOD OF PRODUCING THEM (71) We, BUNKER RAMO CORPORATION a Corporation organised and existing under the laws of the State of Delaware, United States of America, of 900 Commerce Drive, Oak Brook, Illinois, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following state ment:- The invention relates to multiple contact assemblies and a method of producing them.

Known multiple contact assemblies include contact members produced by slotting individual contact members from material in the form of a band. Each contact member consists of two congruent resilient arms and a web joining the arms at the ends opposite to the contact tips. After the slotting, the arms are bent around the line of symmetry of the contact member, with the line extending parallel to the direction in which a plug is inserted, so that the two congruent blade arms form a pair of arms resembling a tuning fork. The tuning fork defines the opening of a slit between the contact tips to allow insertion of a p]ug and has a U-shaped cross section when viewed in the area opposite the slit and in conjunction with the web. A terminal post provided with a bracket section is attached to the web. An insulating housing is provided for the resilient contacts produced in the above manner, with the bracket sections of the terminal posts abutting shoulders in the recesses in the housing.

However, due to the large number of steps required for the production of the individual contact blades, the above process is time-consuming and expensive. In addition, the waste from the slotting implies great expenditures of material.

The goal of the present invention is to develop a process of the above-specified type, which makes it possible to produce multiple contact assemblies rapidly and at low cost.

According to the present invention there is provided a method of producing multiple contact assemblies from a band of material, comprising the steps of slotting a portion of the band to form a plurality of contact member blanks connected by a web, simultaneously bending the blanks around at least one axis common to the plurality of blanks and parallel to a longitudinal axis of the web to form contact members each with a stem portion and two spaced apart arms extending from the stem portion for reception of a pin contact therebetween, attaching a respective terminal post to the stem portion of each of the contact members while the members are still connected to the web to form two-piece contacts, inserting a plurality of two-piece contacts into an insulating housing, and subsequently severing the contacts from the web.

The terminal posts can be simultaneously applied to the contact members and welded in a single step. The common production of a plurality of contact members reduces the time required for the bending operations, the mounting of the terminal posts, and the insertion into the insulating housing. Very little material is required for these operations. Templates and gauges can be used to simplify many process steps and to automate them. The bending employed in the invention contrasts with the prior bending of the contact members around individual axes after the slotting operations, with the axes of bending extending parallel to the direction of insertion.

Further according to the invention there is provided a multiple contact assembly comprising an insulating housing and a plurality of contacts mounted in the housing, each contact including an h-shaped contact member with two resilient arms, a double layer stem portion aligned with one of the arms and a shoulder portion connecting the double layer stem portion to the other arm, and a terminal post attached to the double layer stem portion of the contact member with an end of the post against the shoulder portion of the contact member, the thickness of the terminal post and the thickness of the double layer stem portion being such that the centre line of the terminal post is coincident with the centre line between the two arms.

It is known in the production of knife-like contacts and assemblies containing them to produce the individual knife-like contacts connected via a slotted strip and to break off the strip after inserting the contacts into an insulating housing, but in that case the problems originating from the bending of the contact members and from the attachment of the terminal posts do not arise. Therefore, a process suitable for producing assemblies with knife-shaped contacts cannot be employed for producing multiple contact assemblies having bent contact members and terminal posts attached thereto.

Furthermore, a process is known in which the contacts of a strip are jointly bent while the contacts are in the connected state. However, those assemblies do not comprise insulating housings. After initially slotting the arms at two opposite sides of a sheet metal plate, the plate is bent around the centre line so that congruent pairs of arms are formed in alignment. After that, a plastic strip is moulded in the region of the arms and the individual contacts are electrically separated from each other by cutting operations. In those contact assemblies, the terminal posts are formed by the bent or folded sheet metal pins which remain after the cutting operations. Terminal posts of this type cannot support great loads and proved to be unsuitable for wire wrapping installations. Additionally, the moulding of the plastic strips is a complicated operation.

In the preferred embodiment of the invention, the bending step includes folding the contact member blanks through 1800 at a first axis of bending to form the stem portions of double thickness, having two aligned layers, bending one of the layers of each blank back at an angle of about 90" around a second axis of bending to form shoulders at right angles to the stem portions, and bending the said one layer of each member toward the other layer about a third axis to form h-shaped members; and wherein the terminal posts are attached to the stem portions with the ends of the posts engaging the shoulders.

Therefore, the terminal posts are relatively strong, and remain joined with the contact members even when they are subjected to a high mechanical force.

Good contact properties are obtained by bending at least one tab integral with the contact member laterally around the aligned portions of the contact member after the contact members have been bent around the first axis of bending. In this manner, the aligned portions of the contact member are prevented from separating. The bending forces resulting from spreading apart the arms are therefore absorbed by the blade contact proper without the arms bearing against the inner walls of the insulating housing.

After inserting the joined blade contacts into a bottom section of the insulating housing excellent support for the blade contacts inside the housing is obtained by closing the bottom section with a lid section which snaps into its position and has chambers for receiving the contact members. In this operation, locking shoulders in the form of steps provided on the inner walls of the chambers are seated on matching recesses provided on the contact members.

The invention will now be explained with reference to a preferred embodiment shown in the drawings, by way of example. In the drawings: Figure 1 shows a portion of a slotted band with contact members which are connected via a strip and have not yet been bent; Figure 2 shows several contacts still attached to the strip; Figure 3 is a side view of the contacts with the strip of Figure 2; Figure 4 is a cross section of a multiple contact assembly including a contact; Figure 5 is front view of a single bent contact member; and Figure 6 is a cross section along line A-B of Figure 5.

Figure 1 shows a portion 1 of a band from which several contact members S (not yet bent) and a slotted strip 15 connecting the contact members have been formed by stamping operations. Points at which a separation is to take place upon breaking the strip material have been scored between the slotted strip 15 and the unbent contact members S during the slotting operations. In the embodiment described, the contact members have a spacing of 2.54 mm(0.1") and the sheet metal has a thickness of 0.25 mm. The initially unbent contact members S are bent in succession around the axes of bending which are denoted by I, II, and III in Figure 1. In this manner h-shaped contact members 2 are obtained.

In Figures 2 and 3, the h-shaped contact members 2 are shown with terminal posts 3 attached thereto by welding. A bent or stem portion 9 which was obtained by folding around axis I consists of two aligned contact sections 9a and 9b. Contact section 9b has recesses 10 which were obtained along with the contact members during the slotting operation. Tabs 11 which are integral with contact section 9a are bent into recesses 10 so that the tabs embrace contact section 9b.

Bent portion 9 is followed by a shoulder 8 obtained by bending around axis II. Axis III of bending is chosen so that contact member 2 has approximately square cross section in the plane of shoulder 8. Shoulder 8 is adjacent an end of two arms 4a and 4b which end in the form of divergent contact tips 5a and 5b. The divergent contact tips form a slit-like opening 7. Contact member 2 is provided with lateral cut-outs 12 which have shoulders 13 ab ove shoulder 8, extending parallel to the longi tudinal axis of the blade contact and disposed o on diagonally opposite sides of arms 4a and 4b and of contact tips 5a and Sb. After bending contact members 2, a terminal post 3 is placed on each of the bent portions 9 so that one end face of the terminal post abuts shoulder 8.

Each terminal post 3 is attached with the aid of welding pipes 17 on bent portion 9 by spot welding. Terminal post 3 consists of a material capable of sustaining mechanical loads formed from a 0.6 mm x 0.6 mm wire material. Terminal post 3 has bevelled end faces 3a and 3b so that the post 3 can be fed into the assembly operations without preliminary alignment work.

About one third of a side face of terminal post 3 rests on bent portion 9. Tabs 11, which embrace contact portions 9a and 9b of bent portion 9 are shaped so that the ends of the tabs bear against terminal post 3. The positions of bending axis III, the thickness of terminal post 3, and the thickness of the sheet metal used for the contact member are chosen so that the centre line MP of terminal post 3 coincides with centre line MS between the arms 4a and 4b which are disposed in a symmetric relationship about, and parallel to, the centre line MS.

In the next operation, contact members 2 which are still connected by slotted strip 15 are inserted into an insulating housing 20 along with posts 3 welded to the contact members.

Terminal posts 3 protrude from openings 25 which are formed as a series of openings in bottom section 21 of insulating housing 20. Figure 4 is a cross section of a blade contact mounted inside insulating housing 20. The bent end of folded portion 9 of contact member 2 is seated on bottom section 21.

After breaking slotted strip 15 along the scored points at which the breaking is to take place, a lid portion 22 provided with chambers 24 is inserted into bottom section 21 of insulating housing 20 by snapping the lid portion 22 into its position with the aid of detents 23.

The cross section of chamber 24 slightly exceeds the greatest horizontal cross section of contact members 2 so that arms 4a and 4b do not touch on the inner walls even when the multiple contact assembly is in the assembled state. The inner walls of the chambers are provided with step-like protrusions 26 on two diagonally opposite sides. Protrusions 26 have locking shoulders 28 perpendicular to the direction in which the contact members are inserted. Furthermore, bevelled guiding sections 29 are provided on the step-like protrusions to facilitate the application and insertion of lid portion 22. Locking shoulders 28 firmly bear against the shoulders 13 of the cut-outs 12. The thickness of each protrusion 26 is slightly smaller than the width of each cut-out 12 so that the lid portion can be easily applied. Since protrusions 26 and cut-outs 12 are provided on diagonally opposite sides, the blade contacts and the terminal posts can be inserted, even after 1800 rotation, into the bottom portion 21 of insulating housing 20. This guarantees a simple, reliable assembly of the multiple contact assembly.

Contact member 2 which was bent to have the shape of an "h"(see Figure 2 and 3) is a particularly advantageous embodiment. A contact member bent in this manner can be used not only in multiple contact assemblies but also in individual connectors or connectors with circular cross section.

The process described allows the manufacture of all multiple contact assemblies having terminal posts attached by welding to the contacts. To this end, a plurality of contact members is formed simultaneously by bending around common axes of bending, all terminal posts of a contact strip are attached in a single operation, and the contact members are simultaneously mounted in an insulating housing while they are still connected.

WHAT WE CLAIM IS: 1. A method of producing multiple contact assemblies from a band of material, comprising the steps of slotting a portion of the band to form a plurality of contact member blanks connected by a web, simultaneously bending the blanks around at least one axis common to the plurality of blanks and parallel to a longitudinal axis of the web to form contact members each with a stem portion and two spaced apart arms extending from the stem portion for reception of a pin contact therebetween, attaching a respective terminal post to the stem portion of each of the contact members while the members are still connected to the web to form two-piece contacts, inserting a plurality of two-piece contacts into an insulating housing, and subsequently severing the contacts from the web.

2. A method according to Claim 1, wherein the bending step includes folding the contact member blanks through 1800 at a first axis of bending to form the stem portions of double thickness, having two aligned layers, bending one of the layers of each blank back at an angle of about 90" around a second axis of bending to form shoulders at right angles to the stem portions, and bending the said one layer of each member toward the other layer about a third axis to form h-shaped members; and wherein the terminal posts are attached to the stem portions with the ends of the posts engaging the shoulders.

3. A method according to Claim 2, wherein after bending the blanks, at least one tab integral with one of the layers is bent over the other layer to secure the layers together in the stem portion of each member.

4. A method according to Claim 1, 2 or 3 further comprising the step of securing a lid portion of the insulating housing after inserting the contacts, the lid portion having chambers

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. opening 7. Contact member 2 is provided with lateral cut-outs 12 which have shoulders 13 ab ove shoulder 8, extending parallel to the longi tudinal axis of the blade contact and disposed o on diagonally opposite sides of arms 4a and 4b and of contact tips 5a and Sb. After bending contact members 2, a terminal post 3 is placed on each of the bent portions 9 so that one end face of the terminal post abuts shoulder 8. Each terminal post 3 is attached with the aid of welding pipes 17 on bent portion 9 by spot welding. Terminal post 3 consists of a material capable of sustaining mechanical loads formed from a 0.6 mm x 0.6 mm wire material. Terminal post 3 has bevelled end faces 3a and 3b so that the post 3 can be fed into the assembly operations without preliminary alignment work. About one third of a side face of terminal post 3 rests on bent portion 9. Tabs 11, which embrace contact portions 9a and 9b of bent portion 9 are shaped so that the ends of the tabs bear against terminal post 3. The positions of bending axis III, the thickness of terminal post 3, and the thickness of the sheet metal used for the contact member are chosen so that the centre line MP of terminal post 3 coincides with centre line MS between the arms 4a and 4b which are disposed in a symmetric relationship about, and parallel to, the centre line MS. In the next operation, contact members 2 which are still connected by slotted strip 15 are inserted into an insulating housing 20 along with posts 3 welded to the contact members. Terminal posts 3 protrude from openings 25 which are formed as a series of openings in bottom section 21 of insulating housing 20. Figure 4 is a cross section of a blade contact mounted inside insulating housing 20. The bent end of folded portion 9 of contact member 2 is seated on bottom section 21. After breaking slotted strip 15 along the scored points at which the breaking is to take place, a lid portion 22 provided with chambers 24 is inserted into bottom section 21 of insulating housing 20 by snapping the lid portion 22 into its position with the aid of detents 23. The cross section of chamber 24 slightly exceeds the greatest horizontal cross section of contact members 2 so that arms 4a and 4b do not touch on the inner walls even when the multiple contact assembly is in the assembled state. The inner walls of the chambers are provided with step-like protrusions 26 on two diagonally opposite sides. Protrusions 26 have locking shoulders 28 perpendicular to the direction in which the contact members are inserted. Furthermore, bevelled guiding sections 29 are provided on the step-like protrusions to facilitate the application and insertion of lid portion 22. Locking shoulders 28 firmly bear against the shoulders 13 of the cut-outs 12. The thickness of each protrusion 26 is slightly smaller than the width of each cut-out 12 so that the lid portion can be easily applied. Since protrusions 26 and cut-outs 12 are provided on diagonally opposite sides, the blade contacts and the terminal posts can be inserted, even after 1800 rotation, into the bottom portion 21 of insulating housing 20. This guarantees a simple, reliable assembly of the multiple contact assembly. Contact member 2 which was bent to have the shape of an "h"(see Figure 2 and 3) is a particularly advantageous embodiment. A contact member bent in this manner can be used not only in multiple contact assemblies but also in individual connectors or connectors with circular cross section. The process described allows the manufacture of all multiple contact assemblies having terminal posts attached by welding to the contacts. To this end, a plurality of contact members is formed simultaneously by bending around common axes of bending, all terminal posts of a contact strip are attached in a single operation, and the contact members are simultaneously mounted in an insulating housing while they are still connected. WHAT WE CLAIM IS:

1. A method of producing multiple contact assemblies from a band of material, comprising the steps of slotting a portion of the band to form a plurality of contact member blanks connected by a web, simultaneously bending the blanks around at least one axis common to the plurality of blanks and parallel to a longitudinal axis of the web to form contact members each with a stem portion and two spaced apart arms extending from the stem portion for reception of a pin contact therebetween, attaching a respective terminal post to the stem portion of each of the contact members while the members are still connected to the web to form two-piece contacts, inserting a plurality of two-piece contacts into an insulating housing, and subsequently severing the contacts from the web.

receiving the contact members, such that locking shoulders of step-like protrusions on the inner walls of the chambers engage shoulders provided on the contact members to prevent removal of the contacts.

5. A multiple contact assembly comprising an insulating housing and a plurality of contacts mounted in the housing, each contact including an h-shaped contact member with two resilient arms, a double layer stem portion aligned with one of the arms and a shoulder portion connecting the double layer stem portion to the other arm, and a terminal post attached to the double layer stem portion of the contact member with an end of the post against the shoulder portion of the contact member the thickness of the terminal post and the thickness of the double layer stem portion being such that the centre line of the terminal post is coincident with the centre line between the two arms.

6. A multiple contact assembly according to Claim 5, wherein each contact member includes at least one tab integral with one of the layers of the double layer stem portion, the tab being wrapped over the other of the layers.

7. A multiple contact assembly according to Claim 5 or 6, further comprising a lid section for the housing, the lid section having individual chambers receiving the contact members, the interior walls of the chambers including step-like protrusions with bevelled guiding sections and retaining shoulders, the resilient arms of the contact members including diagonally opposite cut-out portions forming shoulders engaging the retaining shoulders.

8. A multiple contact assembly according to Claim 7, wherein the cross section of the chambers slightly exceeds the cross section of the contact members so that the arms do not touch the walls of tile chambers.

9. A multiple contact assembly substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.