GB2124292A

GB2124292A - Locking separable captive screw

Info

Publication number: GB2124292A
Application number: GB08316949A
Authority: GB
Inventors: Gilles Francois Andre Tournier
Original assignee: Deutsche ITT Industries GmbH; ITT Industries Inc
Current assignee: TDK Micronas GmbH; ITT Inc
Priority date: 1982-07-02
Filing date: 1983-06-22
Publication date: 1984-02-15
Also published as: GB2124292B; DE8318459U1; FR2529629A1; GB8316949D0

Abstract

A captive screw for a connector is made in two parts, the first (2) of which is passed through an opening of a connector shell (1). The second part (3) is fitted on a shaped end (7, 8, 9) of the first part and locked axially by the wide base (20) of a frusto-conical part (8) of the end of the first part engaging behind internal walls (16) inside the second part. The flattened end (9) of the first part engages in slots (14 and 15) of the second part to prevent relative rotational movement so that rotation of the head (10) of the second part produces rotation of the threaded end (6) of the first part. <IMAGE>

Description

SPECIFICATION Device for locking separable components together This invention relates to a device for locking separable components together, and in particular, concerns a captive screw for electrical connectors.

When male and female connectors halves are assembled, and it is desired to hold their shells against one another reliably, a locking system is used. Locking systems of this type often use lateral lugs attached to the shells. For a knurled nut locking device, a male part and a female part are respectively mounted on the opposite lugs of the two shells to be locked. The female part is fitted with a threaded rod on either side of the lug of the first shell, which can, for example, be attached to a supporting panel by means of a nut, and a threaded sleeve intended to receive the threaded rod of the corresponding male part. This male part, whilst being coupled to the lug of the other shell, must be capable of being moved in the tightening or loosening direction, so as to lock or unlock the connectors.This part may consist of a screw, rendered captive, on the lug of the shell, by means of a locking ring or a screw in two sections located on either side of the lug, these sections being coupled by bonding or crimping.

In addition to the number of components involved and the problems encountered in storage and delivery to the assembly site, this type of locking system has the drawback of requiring handling of small dimension parts few millimetres -- and to couple the male part to its shell, of requiring a special tool, or the use of a tube of adhesive.

When the locking system is not systematically fitted to connector shells, but installed as required by the user himself, the importance attached to the simplification of the assembly of the parts forming the locking system can be fully appreciated.

It is therefore an object of the invention to improve known male screw locking systems by simplifying them, i.e. by proposing a new, easy-tohandle male part, which is easy to insert in the opening of a shell lug, which does not require any special tool, and dispenses with the present bonding or crimping attachments, or instaliation of a locking ring.

According to the invention in its broadest aspect, there is provided a device for locking separable components together characterised in that it consists of first and second separate parts, one used for attachment, and the other to operate the previous part, the latter comprising portions of appropriate shape to co-operate with corresponding portions of the second part, so as to couple the parts to one another, both axially and rotatingly, each of these parts also comprising coupling means to a support so that after mounting the parts on this support, they are captively locked to the support.

The installation of this device is simple. It consists in inserting the shaped end of the first part in the shell attachment opening, from one surface of the latter, until a shoulder comes into contact with this surface and stops insertion. The sleeve is then slid from the other side of the shell to the shaped end; this then locks, rendering the first part captive, while permitting its rotation in either direction.

An embodiment of the invention will now be described by way of example with reference to the accompanying drawing representing in a perspective view the two parts of a device intended to lock separable components together, in accordance with the present invention.

The device described can be fitted to a male or female connector shell; this shell bears the reference 1 on the figure. The device consists of two parts 2 and 3, part 2 behaving as an attaching screw in the female element of the shell locking system, part 3 forming the movable sleeve, accessible to an operator.

Part 2 comprises a central part 4, the diameter of which is related to the opening of shell 1, in which it can be housed without difficulty; this is associated with a flange 5, the diameter of which is greater than that of the opening. On one side of this central part is provided a threaded end 6, and on the other side, the other end of part 2 is shaped so that it provides a cylindrical body 7, a truncated cone body 8 and a flattened head 9.

Part 3 - the device operating sleeve comprises a head 10, which is knurled to facilitate manual control and provided with a slot 11 for a screwdriver. Head 10 is extended by two lips 12 and 13, which between them determine slots 14 and 15, the width of which corresponds to the thickness of flattened head 9. Each lip 12 and 13 also features an interior wall such as wall 16, which alone is visible in the figure: between them, both walls 16 determine a circular aperture or opening, the diameter of which corresponds to that of the cylindrical body 7. Moreover, the length of walls 16 is equal to that of the body 7. It should be noted that each wall 1 6 of the lips 12 and 13 outwardly terminates in a chamfer 17.

After this description of the parts of the device of the invention, the manner in which these co-operate with each other when parts 2 and 3 are assembled will now be described.

The head 9 of the part 2 is inserted through the opening of the shell 1, in the direction indicated by the arrow 18, until the flange 5 comes into contact with the surface of the shell 1. Then, sleeve 3 is fitted on part 2 by inserting the flats of head 9 in slots 14 and 1 5 and pushing the sleeve in the direction of arrow 1 9. When the walls 1 6 reach the level of body 8, they bear against its truncated cone surface, causing them to separate gradually from one another, the slots 14 and 1 5 providing appropriate elasticity for the lips 12 and 13.When the complete lengths of walls 16 have slid over the edge formed by the wide base 20 of the truncated cone section of body 8, and these walls 16 are completely facing body 7, body 8 no longer bears against walls 16, so that lips 12 and 13 can return to their initial position in which their distance approximately corresponds to the diameter of body 7. These are held between base 20 of body 8 and central part 4; it should be noted that in this position, the end of head 9 bears against the base of slots 14 and 1 5. To release sleeve 3, it is necessary to separate lips 12 and 1 3 sufficiently to enable passage of body 8 between walls 1 6 and to pull the sleeve in the direction opposite to arrow 19.

With the walls 1 6 in place around body 7 the flat head 9 is located at the base of slots 14 and 1 5. Thus, by turning the head 10 in the direction of arrow 21 or 22 -- manually or using a screwdriver -- head 9 is driven simultaneously by lips 12 and 13, and consequently, the whole part 2, causing threaded end 6 to rotate in the tightening or loosening direction. When this threaded end engages a nut part coupled to the other shell, rotation according to arrows 21 or 22 serves in fact to lock or unlock the connector shells.

Thus, as long as parts 2 and 3 have not been separated by separating lips 12 and 13 to release head 9, the captive device of the invention remains coupled to shell 1. It should be noted that, on locking, i.e. when rotating according to arrow 21, the free ends 23 of lips 12 and 13 bear against the surface of shell 1 to attract the other shell. Conversely, on unlocking, when rotating according to arrow 22, flange 5 bears against the other surface of the shell.

Claims

1. A device for locking separable components together characterised in that it consists of first and second separate parts (2 and 3), one (2) used for attachment, and the other (3) to operate the previous part (2), the latter comprising portions (7, 8 and 9) of appropriate shape to co-operate with corresponding portions (12, 13, 14, 15 and 16) of the second part, so as to couple the parts to one another, both axially and rotatingly, each of these parts also comprising coupling means (4, 5, 23) to a support (1), so that, after mounting the parts (2 and 3) on this support (1), they are captively locked to the support.

2. A device in accordance with claim 1, characterised in that the first part (2) used for attachment, comprises a threaded end (6) and a shaped end presenting portions (7, 8 and 9) of appropriate forms, the zone located between these two ends comprising the coupling means (4 and 5) to the support (1).

3. A device in accordance with claim 2, characterised in that the shaped end comprises a cylindrical body (7), a truncated cone-shaped body (8) and a flattened head (9).

4. A device in accordance with claim 2, characterised in that the zone comprises a cylindrical part (4), the diameter of which corresponds to that of the opening in the support (1) intended to accommodate it, together with a flange (5), the diameter of which is greater than that of the opening.

5. A device in accordance with claim 1, characterised in that the part (3) used to rotate the attaching part (2) includes a knurled head (10) for manual control and a slot ( 1 1 ) for screwdriver control of such rotation.

6. A device in accordance with claim 3, characterised in that the second part (3), used to rotate the first part (2), comprises lips (12 and 13) determined by slots (14, 15) rendering the lips elastically deformable, slots (14, 15) enabling insertion of the flat head (9) to control rotation of the part (2), the inside walls of the lips being shaped (16) to co-operate with the bodies (7 and 8) so as to ensure axial coupling by engagement of the parts (2 and 3).

7. A device in accordance with claim 3, characterised by the fact that the cylindrical body (7) and the truncated cone body (8) are adjacent, the wide base (20) of the truncated cone body (8) having a diameter greater than that of the cylindrical body (7).

8. A device according to claim 6, characterised in that the lips (12, 13) are semi-circular, and separated by slots (14 and 1 5), the end of each slot opposite the drive head (10) comprises an internal wall (1 6), these walls bounding a circular opening, the diameter of which corresponds to that of the large base of the truncated cone body (8), the length of the walls (16) corresponding to the length of body (7) between the cylindrical part (4) and the wide base of the body (8).

9. A device in accordance with claim 6, characterised in that the length of the shaped end (7, 8, 9) of the first part (2) corresponds to the depth of slots (14 and 15) on the second part (3).

10. A device for locking separable components together substantially as described with reference to the accompanying drawings.