Contact mount strip and process for severing a contact held on said strip

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a contact mount strip as well as to a process for severing a contact held on the strip. More particularly, it finds application in the automation of a process for mounting these contacts in a connector which has receptacles for accomodating each a contact, a socket or a pin. The contacts inserted in this kind of connector are sometimes miniature-sized and fragile. A strip according to the invention allows easy transportation of the contacts mounted on the strip, as well as safe mounting of contacts, particularly when the latter are miniature-sized.

2. Description of Prior Developments

In prior art, from document U.S. Pat. No. 5,456,616 the existence of bandoliers is known from U.S. Pat. No. 5,456,616. These bandoliers (preferably shaped rather than cut out) are designed to support and. transport contacts in a typically coiled strip. In this manner, on the one hand, contacts are delivered more easily, without interlocking, and on the other hand, the introduction of contacts in connector receptacles may be more effectively automated, thanks to the provision of a standard spacing therebetween. These bandoliers are particularly designed for displacing miniature contacts. A bandolier has contacts in the same parallel arrangement as required for insertion in a connector. To this end, a connector receiving this type of contacts has several paralleled receptacles. This bandolier, which is provided in coiled form, is less space-requiring during transportation. Thanks to this bandolier, miniature contacts may be massively transported from a manufacturing site to an operating site. During transportation, the contacts mounted on the bandolier are protected from impacts and maintained intact, which cannot be ensured when bulk contacts are transported.

Prior art miniature contacts, which are to be mounted in connector receptacles, typically have a generally cylindrical shape. The receptacles for receiving these contacts also have a cylindrical shape. A diameter of a receptacle is such that it can only receive a single contact. However, a diameter of a receptacle is slightly greater than a diameter of a contact. Hence, a contact inserted in its receptacle slightly floats therein. Therefore, in order that the contact might be retained in its receptacle in prior art, a retaining member is used around the contact. This retaining member is, as known, a retaining clip. The retaining clip has jaws spaced apart slantwise with respect to the contact, and these jaws may be temporarily snapped against the contact, to be restored in their spaced apart condition when the snapping stress stops. The retaining clip is mounted around the contact before insertion of the contact in its receptacle. Then, the ends of the jaws of the retaining clip interact with a release in the inner walls of the receptacle.

Additionally, in the prior art, contact bandoliers are known, i.e. coiled strips which only have retaining clips. In the mounting step, the retaining clips are severed from the coiled strips, to be mounted on the contacts. Further, the contacts so equipped, each surrounded by a retaining clip, are inserted in connector receptacles.

In the prior art, positioning a contact inside a connector receptacle involves a problem. Such positioning is not immediate and requires a number of operations, particularly providing contacts with retaining clips or previously positioning such retaining clips in the receptacles before positioning contacts. Further, in order to mount such a contact, two kinds of intermediate bulky elements are needed, on the one hand a bandolier for contact support and on the other hand a strip of retaining clips. A further drawback of the prior art consists in that this process for positioning a contact inside a connector generates two waste types: empty bandoliers, whose contacts have been severed and empty strips, whose retaining clips have been removed. Also, these two intermediate objects are two separate elements to be supplied and stocked in equal amounts at the connector assembly site. Errors might occur if different contact formats and retaining clip formats are available.

SUMMARY OF THE INVENTION

The invention has the object to solve the above problems by providing a single strip which has, on the one hand a first means for holding a contact on said strip, and on the other hand a second means for also holding the contact on said strip and simultaneously forming a retaining clip around the contact. The first means has the main function, like in prior art, to hold the contact on the strip when the strip is transported. The second means surrounds the contact and forms a clip which acts as a retaining member. In the invention, the second means, said clip, may be severed from the strip. When the clip is severed from the strip, the contact remains inside the second means, whereby it is still fitted with the clip. The clip, formed by the second means around the contact acts as a contact retaining member, when the contact is inserted in a connector receptacle. Then, the clip wrapped around the contact interacts with the inner walls of the receptacle. Preferably, the clip is severed after transportation of the bandolier, upon insertion of the contact in its receptacle.

Therefore, the solution provided by the invention is such that a single strip is provided, also able to be coiled, that the contact is mounted in the first means and in the second means simultaneously and that mounting of the contact, fitted with its clip, in a connector receptacle may be automated. Further, a single strip is provided, which forms the only waste resulting from mounting of contacts in connector receptacles. Additionally, no inventory error may occur.

Then, the invention relates to a contact mount strip, including a first device for temporarily holding a contact, and a contact supported in such first device, characterized in that it includes a second retaining device which forms a retaining clip around a section of the contact.

The invention also relates to a process for severing a contact held in a clip of such a strip, characterized in that it includes the following steps:

pivoting the contact about a perforated part, while pushing it through a cutout of the strip beyond a plane formed by said strip;

thereby removing the contact from the first device for temporarily holding it by a rotary force;

bending the perforated part through a sufficiently narrow angle to rupture the perforated part;

disengaging the contact and the clip surrounding the contact from the cutout by a translational motion perpendicular to the plane of the strip.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be understood more clearly by reading the following description and by analyzing the accompanying figures. The latter are only shown by way of example and do not intend to limit the invention in any manner. The figures show:

FIG.

1

: a top view of a strip and a contact in accordance with the invention before mounting the contact on the strip;

FIG.

2

: a cross section of a strip equipped according to the invention;

FIG.

3

: a sectional view with time of the process for severing a contact from a strip according to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1

shows a part of the strip

1

of the invention, corresponding to a contact location. This part of the strip

1

is designed to receive a contact

2

. The strip

1

has a first cutout

3

. The first cutout

3

is made according to a first perimeter

4

, particularly by die stamping. The strip

1

has a first temporarily holding device cut out in the strip and particularly shaped according to the first cutout

3

. After shaping, said first device has a substantially rectangular and flat blade

5

. The blade

5

is defined in the same plane as the one formed by the strip

1

. Before mounting a contact on the strip, the blade

5

defined by the perimeter

4

is aligned in the direction of the strip

1

. The blade is linked to the strip

1

on the perimeter

4

by a foot

6

. The foot

6

has a width

7

. The first device has a width

8

. The width

8

is greater than the width

7

.

The first device may be shaped by bending the flanks

9

and

10

of the blade

5

perpendicular to the plane of the strip

1

and by providing them with a substantially cylindrical shape. The flanks

9

and

10

are symmetric with respect to a plane of symmetry

11

which cuts the foot

6

at its center, perpendicular to the strip

1

. The plane

11

is also preferably a plane of symmetry of the first cutout

3

. In order to cover a first section

12

of the contact

2

, the flanks

9

and

10

may be provided with curved tips

9

.

1

and

10

.

1

, at the ends of the blade

5

respectively. As a variant, the flanks

9

and

10

are slightly inclined towards each other. The width

8

and the height of the flanks

9

and

10

are such that the flanks

9

and

10

cannot wholly encircle the circumference of a truncated cylinder formed by the first section

12

. The section A forms a hollow stem for receiving an electric wire, e.g. welded or crimped thereto.

In a preferred embodiment of the invention, the first device includes a second cutout

13

in the strip

1

. The second cutout

13

has a periphery

14

. The second cutout

13

allows to form a second blade

15

. The blade

15

is linked to the strip

1

by a first foot

16

and a second foot

17

. The plane of symmetry

11

passes through the center of the feet

16

and

17

. The blade

15

has a first flank

18

and a second flank

19

. The flanks

18

and

19

are symmetrical with respect to the plane

11

. They are not linked to the periphery

14

of the second cutout

13

. Therefore, like the flanks

9

and

10

, the flanks

18

and

19

may be shaped. Preferably, the flanks

18

and

19

are raised perpendicular to the strip

1

, on the same side, with respect to the plane formed by the strip

1

, as the flanks

9

and

10

, and are provided with a substantially cylindrical shape. The flanks

18

and

19

are then raised so that they may encircle a second section

20

of the contact

2

. In one embodiment, the second section

20

of the contact

2

has the same diameter as the section

12

. Further, the flanks

18

and

19

are such that they do not allow to fully encircle the circumference of a truncated cylinder formed by the second section

20

. They may be provided with curved tips.

The first blade

5

and the second blade

15

so formed constitute a support for the contact

2

on the strip

1

, which is thereby held with a controlled clearance. The obtained blades form two open elastic clamps. When a contact

2

is to be mounted on the strip

1

, then the contact

2

is slid into the two elastic clamps. The clamps are such that they encircle the contact

2

substantially over a first third

21

at a first end of the contact

2

. The contact

2

has an elongate structure with a central section

22

. Said central section

22

is situated on an axis which defines the elongation of the contact

2

. Depending on this longitudinal axis, the contact

2

includes, substantially over another third, at a second end thereof

23

, a pin (not shown) or a socket

25

. The socket

25

(or the pin) is designed to form, in a connector wherein the contact

2

is mounted, an accessible part of the contact

2

to be put in contact with a complementary contact of a complementary connector. In practice, the first section

12

is forcibly inserted between the flanks

9

and

10

and

18

and

19

, which hold it against the strip

1

. The elasticity of the flanks is sufficient to hold it with a certain clearance. The central section

22

may have a smaller diameter, particularly to receive a retaining member, i.e. a retaining clip.

In the invention, the contact

2

is retained on the strip

1

at the end

21

, which has no part to be connected to a complementary contact. In fact, the first blade

5

and the second blade

15

might locally deteriorate the outer surface of the contact

2

. However, since the stem A is designed to receive a conductor of a cable therein, an outer surface of the stem A may be slightly scratched with no damage risk. In the invention, the contact is held against the strip

1

by an end

21

, which is the last to be inserted in a connector. As will be apparent below, the strip will paradoxically keep on having its retention role during mounting.

A bandolier according to the invention, fitted with its contacts, preferably has contacts all of the same type. However, there will only be provided one kind of contact mount strip, regardless of their being male or female contacts. The different part of a contact, according to its being male or female, is not held by the strip

1

.

In the invention, the strip

1

includes a second device

26

to be shaped. The second device

26

is a retaining device. It is formed by a third perimeter

27

of a third stamped cutout

28

. The device

26

is linked to the strip

1

by a third foot

29

and a fourth foot

30

. Therefore, die stamping is effected in two symmetric parts. Preferably, the feet

29

and

30

have a trapezoidal shape, with a large and a small base. Preferably, small bases are embrittled from the start by perforations, e.g. all over their length. The plane of symmetry

11

is also a plane of symmetry of the second device

26

. The plane of symmetry

11

passes through the third and fourth feet

29

and

30

.

Further, the strip

1

has a fourth cutout

31

. The fourth cutout

31

is separated from the third cutout by a segment

32

. The fourth foot

30

is linked to the strip

1

by this segment

32

.

The strip so equipped is carried towards the mounting site. Later, at the mounting site, the segment

32

is separated from the strip

1

, for instance by shearing it. Then, the segment

32

and the fourth foot

30

are removed, particularly by twisting both about the small base of the foot

30

. So, the third cutout

28

will communicate with the fourth cutout

31

. This overall cutout is such that it extends beyond the end of the section

23

of the contact

2

.

Preferably, the second retaining device is formed prior to contact introduction. Therefore, preferably, in order to mount the contact

2

on the strip

1

, the contact is slid through the two devices, already shaped, until the section

12

abuts against the blade

5

. According to a variant, the second device may be formed around the central part

22

of the contact, after or upon mounting the contact

2

on the strip

1

in the supports

5

and

15

. In accordance with another variant, the contact

2

may be mounted on the strip

1

also by wrapping the flanks

9

and

10

around the first section

12

of the contact

2

, and by wrapping the flanks

18

and

19

around the second section

20

of the contact

2

, then by covering the central connecting section

22

with the second device

26

. Typically, the second device

26

fully covers the connecting section

22

. In another embodiment of the invention, the contact

2

may be first inserted in the first temporarily retaining device, then the second device only is shaped directly around the contact

2

.

The cutouts

3

,

13

,

28

and

31

are made along the plane

11

. The plane

11

passes through the center of the foot

6

and of the feet

16

,

17

,

29

and

30

. The contact

2

is laid over the devices

5

and

26

of the strip

1

, so that the longitudinal axis of the contact

2

overlaps the axis

11

.

1

.

The second device

26

covers the connecting section

22

as effectively as possible over the whole circumference and length thereof. At this location, it forms a tube around the contact

2

. The second device

26

includes a first series

33

of holes and a second series

34

of holes. The holes are obtained by stamped cutouts in the strip

1

. There are preferably provided three holes in the first series and two holes in the second. These series of holes are aligned in the direction of the strip

1

. The series of holes are designed to act as series of elastic devices. A first elastic device

35

of the first series

33

of holes has a tab

36

. The tab

36

is flexible inside a hole

37

of the first elastic device

35

. Before mounting the contact

2

on the strip

1

, the tab

36

is preferably bent towards a second side of the plane formed by the strip

1

. The second side is opposite to the one whereon the flanks

9

and

10

and the flanks

18

and

19

are formed. A second type of elastic device

38

may be obtained from the series

34

of holes. Here, the elastic device

38

consists of a flexible wing

39

inside a hole

40

of the second device

38

. Before mounting, the wing

39

is bent outwardly with respect to the strip

1

, on the same side as the tab

36

.

The contact

2

is mounted in the second device

26

in such a manner that the tabs

36

and the tongues

39

increasingly widen around the central part

22

from the end

23

to the end

21

. The tabs

36

and the wings

39

are compressible along a section formed by the central connecting section

22

of the contact

2

. Therefore, when a contact

2

, surrounded by the tube formed by the second device

26

is introduced in a connector receptacle (with the end

23

ahead), the tabs

36

and wings

39

fold down along the contact

2

. The introduction being completed, the wings

39

act as a non-return clip when the contact

2

is inserted in a connector receptacle, and turn back to their widened state in a wider cavity of said receptacle. Hence, they prevent any withdrawal of the contact

2

from the connector wherein the contact

2

has been introduced. The wings

39

widen in such a manner that their ends may abut against a release of an inner wall of a receptacle of this connector. The tabs

36

are in regular arrangement over the periphery of the central connecting section

22

. The tabs

36

, also widened with respect to the connecting section

22

, act as a centering device for the contact

2

in its receptacle. For this reason, they are preferably three in number.

The strip

1

has several contacts like the contact

2

. The contacts are disposed, like the contact

2

, in devices like the devices

5

,

15

and

26

. The strip

1

has contacts in parallel arrangement. The strip

1

with the contacts may be coiled. A coiling axis for this strip is typically parallel to an axis such as the one passing through the plane

11

defined for the contact

2

. Anyway, the coiling radius cannot be too small.

In order to prevent the contacts supported by the strip from crushing when two turns of the strip coil superpose, the strip

1

includes at least one third protection device

41

, as shown in FIG.

2

. The third device

41

is a spacer block. A block of the third device

41

raises perpendicularly to the plane formed by the strip

1

. The block has a backward extension

42

. The backward extension

42

is parallel to the plane formed by the strip

1

. In a preferred embodiment of the invention, the strip

1

has two spacer blocks like the block

41

for contact support. These two blocks are disposed along an axis parallel to the plane

11

. The spacer blocks

41

raise on the same side of the plane formed by the strip

1

as the side whereon the devices

5

,

15

and

26

are formed. The spacer blocks are disposed between two consecutive contacts.

For an enhanced protection of the contacts supported by the strip

1

, a protection sheet

43

is laid over the backward extensions

42

of the spacer blocks

41

, particularly upon coiling. Hence, the protection sheet

43

is coiled parallel to the strip

1

. The height of the blocks

41

is such that the protection sheet

43

does not touch the contacts supported by the strip

1

.

In

FIG. 1

, the foot

29

has a perforated part

44

therein. Hence, when a contact

2

is mounted in a second device

26

, after removing the segment

32

and the foot

33

, the second device

26

, with the contact

2

surrounded thereby may be severed from the strip

1

. In a preferred embodiment of the invention, a pin (not shown) is inserted in the stem A to sever the contact

2

from the strip

1

. So, the contact may be pivoted about a pivot point situated at the perforated part

44

, by using the pin as a lever arm. This movement allows to remove the contact

2

from the elastic clamps

5

and

15

, and to rupture the connection at the perforated part

44

. Finally, the contact

2

held on the pin may for instance be laid on a positioner allowing, after withdrawal of the pin, to put a conductor strand at the right place and to crimp the contact and the conductor strand together. Then, the contact may be handled through the conductor strand and be placed in a corresponding receptacle of a connector.

In one variant, a contact

2

may be severed from a strip

1

by pressing on the second end

23

of the contact

2

. The second end

23

is opposite to the first end

21

.

FIG. 3

shows a male contact

2

whose second end

23

has a pin

24

. The principle wherewith a contact

2

is severed from a strip such as the strip

1

is identical regardless of whether the end

23

has a socket

25

or a pin

24

situated at the second end

23

.

In order to sever a contact from a strip, the contact

2

is oscillated about a pivot point at the perforated part

44

. In this manner, the contact

2

crosses a plane

47

of the strip

1

. It turns in the direction of the curved arrow

48

. To cross the plane

47

, the contact

2

passes through the common opening of the third and fourth cutouts

28

and

31

. The first and second sections

12

and

20

of the contact

2

, held by the flanks

9

and

10

and by the flanks

18

and

19

come out of these elastic support clamps. The contact

2

is oscillated about the pivot point through a sufficient angle, here for instance above 90°, so as to rupture the perforated part

44

. Then, the contact

2

, still fitted with the clip formed by the second device

26

is disengaged, and this assembly passes completely through the common opening of the third and fourth cutouts

28

and

31

. This displacement is effected by a translational motion

49

wherein the pin

24

, or the socket

25

, as the case may be, is in the front position.

The assembly is disengaged from the strip

1

by a translational motion generally perpendicular to the plane

47

. This releases a contact

2

with its clip, ready to be inserted in connector receptacle. If needed, several pins

24

or sockets

25

of a strip section may be simultaneously engaged in a connector, while they take an intermediate pivoting position

50

, between the one wherein they are held on the strip

1

and the one wherein the connecting part

44

is ruptured. This is obtained by rotating a strip section with the contacts to be inserted. Such operation is perfectly fit for automation. Once the insertion is completed, the wings

39

prevent withdrawal from the insertion side. Possibly, the rupture of the perforated part

44

occurs when the wings

39

are locked inside the receptacles.

The strip

1

allows displacement of contacts from one location to the other, while providing these contacts with a retaining clip, which is required for them to be held in a connector receptacle.

Number	Name	Date	Kind
4369572	Atkins	Jan 1983	A
4428642	Schwindt et al.	Jan 1984	A
4687267	Header et al.	Aug 1987	A
5094636	Zinn et al.	Mar 1992	A
5190486	Tsuk	Mar 1993	A
5456616	Fuerst et al.	Oct 1995	A
5974768	Scholzke et al.	Nov 1999	A
6159049	Schramme et al.	Dec 2000	A

Number	Date	Country
4340375	Jun 1995	DE
2103433	Feb 1983	GB

Contact mount strip and process for severing a contact held on said strip

Information

Patent Number

Date Filed

Date Issued

Inventors

Original Assignees

Examiners

Agents

CPC

US Classifications

Field of Search

US

International Classifications

Abstract

Description

Claims

Priority Claims (1)

US Referenced Citations (8)

Foreign Referenced Citations (2)