GB2296995A

GB2296995A - Pull-out apparatus for plug-in units

Info

Publication number: GB2296995A
Application number: GB9518548A
Authority: GB
Inventors: Michael Joist
Original assignee: Schroff GmbH
Current assignee: Schroff GmbH
Priority date: 1995-01-23
Filing date: 1995-09-11
Publication date: 1996-07-17
Anticipated expiration: 2015-09-11
Also published as: GB2296995B; GB9518548D0

Abstract

A withdrawal or extractor device for plug-in units has a support frame 3 for securing a front plate 2 and a circuit board 1 to the profiled rail 12 of a mounting rack. A pivot lever 4 is linked to the support frame 3 and bears with a release shoulder 14 at a front surface 16 of the profiled rail 12. To facilitate the withdrawal and the achievement of a large withdrawal stroke the pivot lever 4 is displaceable relative to the support frame 3 with the aid of a link mechanism consisting of a link pin 10 on the support frame 3 and a link track 18 on the pivot lever 4, the pivot pin 17 of which is displaceable in a longitudinal hole 11 in the support frame 3.

Description

PuU < )ut Apparatus for Plug-ln Units The invention concerns a pull-out (extractor) apparatus for plug-in units which are provided for insertion into mounting racks, with a retaining support for the releasably securing of a front plate as well as a circuit board to a profiled rail of the mounting rack, a pivot lever journalled at the retaining support by means of at least one pivot pin, and with an extractor shoulder at the pivot lever which when the plug-in unit is inserted stands opposite a front surface of the profiled rail.

The invention finds the utility particularly with larger and densely equipped plug-in units which in the inserted position are connected by means of plug-connections with the mounting rack and thus with other electrical components.

The utilisation of four-poled plug-in connections arranged in three rows and equipped with up to 96 spring contacts results in high forces for the insertion and particularly for the pulling-out of the plug-in units from the mounting racks. The requirement of force during pulling-out is significantly greater than that for insertion because at the beginning the high frictional adhesive forces between the microscopically rough connector pins and springs must be overcome.

To overcome the insertion and withdrawal forces, lever-operated extractor or withdrawal devices of the most various sort are known. Their aim is to achieve the highest possible lever ratio and simultaneously to achieve a sufficiently wide displacement through the length of the blades of the commercially conventional plug-in connector. In the design of these devices internationally standardised measurements and spatial requirements must be observed which, for instance regarding the length of the lever arm, may not be exceeded. The underlying task of the invention is to design a pull-out device with which, while maintaining a small space requirement and respecting the industry standards, a highest possible lever ratio and thus lower pull-out forces, while at the same time a higher pull-out stroke, can be achieved.

To solve the task set one starts with pull-out apparatus for plug-in units provided for insertion into mounting racks, with a retaining support for releasably securing a front plate as well as a circuit board at a profiled rail of the mounting rack, a pivoted lever journalled by means of at least one pivot bolt at the retaining support with an extractor shoulder at the pivoted lever which lies opposite to a front surface of the profiled rail when the plug-in unit is inserted. Such a pullout device has become known for instance from the applicant's German Utility Model Application Number G 86 07 046.0. (=GB-B-2 188 196) The task set is solved in that the pivoted lever is displaceable relative to a retaining support by way of a link mechanism.It has been proved that - as it is yet to be explained - by utilisation of a link mechanism by means of which the position of the pivotal axis of the pivot lever is altered during its pivotal movement, the problem can be solved.

Advantageously the pivot bolt seated at the pivot lever is displaceable in a longitudinal hole of the retaining support.

Expediently, as a link mechanism a link pin is arranged at the retaining support and a slide track is provided at the pivot lever.

To reduce the frictional forces the slide pin is formed in right cylindrical shape.

For constructional reasons the slide track is an open channel of rectangular cross-section.

The slide track is so arranged that relative to the pivot bolt it has a concave curvature. In the construction of the curvature of the slide track account can be taken of the kinematics of the stroke, in dependence on the angle of rotation of the pivot lever.

The invention is described below in greater detail by way of the attached sheet of drawing wherein: Fig. 1 shows a retaining support and an associated pivot lever in a perspective view pulled out from each other and on an approximately doubled scale; Fig. 2 is a partial view in vertical section of a plug-in unit inserted into a mounting rack; Fig. 3 shows the plug-in unit according to Fig. 2 in a withdrawn (extracted) position.

The plug-in unit shown partially in Figure 2 consists essentially of a circuit board 1, a front plate 2, a retaining support 3 and a pivoted lever 4.

The circuit board 1 show broken away is made of an insulating material and has an array or grid of holes for securing electrical and electronic components which are connected together by conductive paths. In the region of its front, lower corner the circuit board 1 is screwed to the retaining support 3 by means of a head screw 5. At its rear edge the circuit board 1 carries the connecting bar of a commercially conventional 4-poled plug-in connector the connector blade bar of which is secured to the mounting rack. The circuit board 1 is electrically connected with other components of the mounting rack with the aid of this connector bar.

The front plate 2 consists of an aluminium sheet and is also shown broken away. It is an elongated right angled plate which is pushed by way of its lower narrow side into a transverse slit 6 of the retaining support 3 and is secured there.

The retaining support 3 (see Fig. 1) consists of a cast part and has a rear shoulder 7 with a threaded bore 18 for the screw 5. The transverse slit 6 cut deeply into the body of the retaining support 3 receives the lower edge of the front plate 2 and carries securing means for the front plate. The retaining support 3 has a moulded-on bracket 9 in the form of a three-edged prism with a slide pin 10 projecting at its front side which pin is formed in a right cylindrical shape.

An elongated hole 11 passes through the bracket 9.

It is the task of the retaining support 3 to connect the front plate 2 with the circuit board 1 and releaseably to secure the plug-in unit at one of the front profiled rails 12 (see Fig. 2) of the mounting rack. This fixing takes place by way of a long threaded screw passing through the retaining support 3 which engages in a threaded hole of a thread bar pushed into a longitudinal groove 13 of the profiled rail 12. A positioning pin provided at the retaining support 3 and engaging into the longitudinal groove 13 facilitates the accurate insertion of the plug-in unit into the mounting rack. Elements not provided here with reference numbers are not shown in the drawing, they belong to the self-evident construction of commercially conventional plug-in units and mounting racks.

The two-armed pivot lever 4 made of plastics material (Fig. 1) has at its shorter lever arm an extractor shoulder 14. The longer lever arm serves as an actuating grip 15 on withdrawal (and also on insertion) of the plug-in unit. When the plug-in unit is inserted the extractor shoulder 14 stands opposite the front surface 16 of the profiled rail 12 at a small spacing, as may be seen in Figure 2.

A cylindrical pivot pin 17 projects laterally and transversely at the pivot lever 4 and passes into the longitudinal hole 11 of the retaining support 3, it being not only rotatable but also displaceable therein. Suitable fixing means are provided for journalling the pivot lever 4 at the retaining support 3, for instance a screw which is drawn into a central threaded bore provided in the pivot pins 17. This journalling may also be realised by means of a plastics snap connection.

In addition the pivot lever 4 carries a slide or link track 18. This track 18 is an open channel of rectangular cross-section into which the slide or link pin 10 of the retaining support 3 passes.

In relation to the pivot pin 17 the slide track 18 has a concave curvature; an initial region 19 of this track 18 lies concentrically with the pivot pin 17.

When the plug-in unit is inserted into the mounting rack, see Figure 2, the pivot lever 4 is at an upper position, the extractor shoulder 14 lies at a small spacing opposite the front face 16 of the profiled rail 12 and the up to 100 or more connectors of the connector bar seated at the circuit board 1 are plugged into the blades of the blade bars secured to the mounting racks. The pivot pins 17 bears against the edge of the longitudinal hole 11 facing the bracket 9. By utilising the threaded screw passing through the support frame 3 the plug-in unit is secured to the mounting rack.

After releasing the threaded screw that fixes the support frame 3, the plug-in unit may be pulled out from the mounting rack. To this end the actuation grip 15 is pressed by hand downwardly in the direction of arrow 20, whereby the link (slide) mechanism is activated in that the link pin 10 slides forwardly in the slide track 18. As long as the link pins 10 moves in the initial region 19 no displacement of the plug-in unit takes place, nor is it displaced on the pivot pin 17 in the longitudinal hole 11 of the retaining support 3. This initial pivoting of the pivot lever 4 is utilised, for instance, to actuate a microswitch. When the actuation grip 15 is then further pressed downwardly, the extractor shoulder 14 bears on the front face 16 of the profiled rail 12 and its internal link shoulder 21 adjacent to the pivot pin 17 withdraws the plug-in unit forwardly in the direction of the arrow 20 via the slide pins 10 of the retaining support 3 from the mounting rack. In the course of this pivotal movement of the pivot lever 4, the pivot pin 17 of the pivot lever 4 is displaced in the longitudinal hole 11 of the retaining support 3 in the direction towards its extractor shoulder 14. During this pivotal movement the connectors of the plug connector are pulled out of the blades (pins) wherein, because of the lever ratio of the pivot lever 4, only a modest expenditure of force is necessary.However, the pull-out or withdrawal path achieved by the slide mechanism is of decisive significance, which path is always greater than the length of the plugs of the plug-in connectors, without exceeding the spatial requirement prescribed by standards for the withdrawal device.

The end of the withdrawal process achieved with the slide mechanism is reached when the extractor shoulder 14 finds no further application on the front surface 16 of the profiled rail 12.

Then a boss 23 (Fig. 3) provided at the pivot lever 4 is actuated which presses itself into the front edge 24 of a frontal longitudinal bar 25 of the profiled rail 12. Figure 3 shows the plug-in unit in its fully withdrawn position in which it can be taken out of the mounting rack.

As an aid for pulling in the plug-in unit, a nose 26 lying oppositely the boss 23 is provided on the pivot lever which on pivoting of the pivot lever in a direction opposite to that of the arrow 20 engages into a recess 27 in the longitudinal bar 25 of the profiled rail 12. The profiled rail 12 carries a row of equidistantly arranged similar recesses 27. On pulling the plug-in unit in the pivot lever 4 is guided by the slide mechanism during which the slide mechanism works in the opposite direction.

In the annexed claims reference numbers have been added purely by way of illustration and as an aid to comprehension but absolutely no limitation of the scope of the claims is intended thereby.

List of Reference Number 1 Circuit board 2 Front plates 3 Retaining support 4 Pivot lever 5 Head screw 6 Cross-section 7 Shoulder 8 Threaded bore 9 Bracket 10 Slide pin 11 Longitudinal hole 12 Profiled rail 13 Longitudinal groove 14 Extractor shoulder 15 Actuation grip 16 Front surface 17 Pivot pin 18 Slide track 19 Initial region 20 Arrow 21 Slide shoulder 22 Arrow 23 Boss 24 Front edge 25 Longitudinal bar 26 Nose 27 Recess

Claims

Claims 1. Pull-out (extractor) apparatus for plug-in units provided for insertion into mounting racks, comprising: - a retaining support for releasably securing a front plate as well as a circuit board at a profiled rail of the mounting rack, - a pivoted lever journalled by means of at least one pivot bolt at the retaining support, - and an extractor shoulder at the pivoted lever which lies opposite to a front surface of the profiled rail when the plug-in unit is inserted, the pivoted lever (4) being displaceable relative to the retaining support (3) by way of a link mechanism.
2. Pull-out apparatus according to claim 1, wherein the pivot bolt (17) seated at the pivot lever (14) is displaceable in a longitudinal hole (11) of the retaining support (3).
3. Pullsut apparatus according to claim 1 or 2, wherein the slide track (18) is an open channel of rectangular cross-section.

4 Apparatus according to claim 1 substantially as herein described with reference to and as shown in the accompanying drawing.

3. Pull-out apparatus according to claim 1 or 2, wherein as a slide mechanism a slide pin (10) is arranged at the retaining support (3) and a slide track (18) is provided at the pivot lever (4).

4. Pull-out apparatus according to claim 3, wherein the slide pin (10) is formed rightcylindrically.

5. Pull-out apparatus according to claim 3 or 4, wherein the slide track (18) is an open channel of rectangular cross-section.

6. Pull-out apparatus according to claim 3, wherein in relation to the pivot pins (17) the slide track (18) has a concave curvature.

7. Apparatus according to claim 1 substantially as herein described with reference to and as shown in the accompanying drawing.

Amendments to the claims have been filed as follows Claims 1. Pullsut (extractor) apparatus for plug-in units provided for insertion into mounting racks, comprising: - a retaining support (3) for releasably securing a front plate as well as a circuit board on a profiled rail of the mounting rack, - a pivoted lever (4) journalled by means of at least one pivot bolt (17) on the retaining support and displaceable relative to the latter by means of a slide mechanism, - and an extractor shoulder on the pivoted lever (4) which lies opposite to a front surface of the profiled rail when the plug-in unit is inserted, the pivoted lever (4) being displaceable relative to the retaining support (3) by way of a link mechanism, - the pivot bolt (17) being displaceable in a longitudinal hole (11) of the retaining support (3), - said slide mechanism including a slide pin (10) arranged on the retaining support (3) and a slide track (18) provided on the pivot lever (4), and wherein - the slide track (18) has a concave curvature relative to the pivot bolt (17).

2. Pullsut apparatus according to claim 1, wherein the slide pin (10) is formed right cylindrically.