GB1576012A

GB1576012A - Mounting of electrical units

Info

Publication number: GB1576012A
Application number: GB193877A
Authority: GB
Original assignee: Midland Electric Manufacturing Co Ltd
Current assignee: Midland Electric Manufacturing Co Ltd
Priority date: 1977-01-18
Filing date: 1977-01-18
Publication date: 1980-10-01
Also published as: FR2377745B3; DE2801651A1; FR2377745A1; DE7801134U1

Description

(54) MOUNNNG OF ELECTRICAL UNITS (71) We, MIDLAND ELECTRICAL MANUFACTURING COMPANY LIMITED, a British Company, of Reddings Lane, Birmingham B11 3EZ, do hereby decIare 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 statement : This invention relates to the mounting of electrical units.

Electrical units are frequently designed to enable them to be mounted on DIN rails, such as those described in German Standard DIN 46 277 Sheet 3. Fbr that purpose, the mounting face of each unit is formed with a slot to receive the DIN rail and permanently carries a spring-biased pIunger which engages with one edge of the rail to retain the unit to the rail. The unit cost is therefore greater than that of a technically identical unit not equipped with such a clip.

One aspect of' the invention resides in an electrical unit having first means capable of receiving fixing members intended to- enter a flat mounting surface to which the unit is to be secured in position,. and second means comprising slots capable of receiving rail mounting clips separable from the unit for alternatively clipping the unit to a mounting rail. The unit may then be mounted' either on a flat surface using conventional fixing methods, in which case the user is saved the expense of the clips, or on a mounting rail, in which case the user can obtain the clips separately.

A second aspect of the invention provides the combination of such an electrical unit and at least two rail-mounting clips which are separate from the unit but are attachable thereto, and which, when so attached, project beyond the unit and' enable the unit to be clipped on to opposite edges of a mounting rail. Preferably each clip is made integrally from leaf spring and advantageously comprises an attachment part adapted to be attached to the unit and at least one resilient foot which is angled fo grip an edge of a mounting rail. The attachment part may have a resilient tang upset from the plane of the attachment part, to enable the clip to be retentively attached to the unit The extremity of the foot may be bent outwardly to form a lug, enabling the foot to be released from a DIN rail..

Another aspect of the invention resides in a method of fixing an electrical unit to a mounting rail, in which method separate clips are attached to the sides of the unit, each clip having at least one resilient fdot which is angled to grip the rail edge, the unit is placed on the rail and the foot or feet of each clip is or are urged over the respective edge of the rail.

The invention may be more readily understood by way of example from the following description of the mounting of a unit, reference being made to the accompanying drawings, in which: Figures 1 and 2 are respectively a front view of a clip and a section on the line II-II of Figure 1 Figure 3 is a perspective view of a unit fixed to a DIN rail by two of the clips, Figure 4A and 4B indicate the method of attaching the unit to the rail, Figure 5 schematically illustrates the gripping action of the spring clips, and Figure 6 is a view similar to Figure 3, but showing another form of clip.

The clip 12 shown in detail in Figures I and 2 is a single leaf spring stamping and has an attachment part 13 and a foot part 14. In the attachment part 13, a Ushaped. slot 15 is stamped out of the leaf spring to leave a central tang 16 which. is upset at its free end, as can be clearly seen in Figure 2, that free end thus projecting out of the plane of the attachment part.

The foot 14 is tongue-shaped and is bent outwardly, i.e. in the same direction as the tang 16 and then back to form an inclined face 17. The face 17 extends rearwardly to a point behind the plane of the attachment part 13, and is then bent forwardly and sharply to form a lug 18.

In Figures 3 and 4, the unit to be fixed is exemplified by an electrical contactor 21 which is to be mounted on and secured to a DIN rail 22 which has parallel lateral edges 23. Normally the rail 22 is secured in position with the plane through the edges 23 vertical, but for convenience is shown in Figure 3 with that plane horizontal.

The unit has a mounting face 21A, which is flat over the area of the face of rail 22.

Integral side bars 24 extend along the edges of the sides of the unit adjacent the face 21A. A slot 25 is formed between the side of the unit 21 and each bar 24, and opens to the mounting face 21A; each slot can receive a clip 12. When it is required to fix the unit to the DIN rail 22, one of the clips 12 is pushed upwardly through each slot 25, until the resilient tang emerges above the bar and springs outwardly to lock the clip against downward movement.

The unit 21 has additionally at least two integral shoulders 21B extending outwardly from the sides. In the construction shown in Figure 3, there is a single shoulder on each side and these shoulders- are located diagonally opposite one another. The shoulders 21B extend beyond the plane of face 21A to form location feet 26 which are spaced apart by the width of the rail 22 between edges 23. A hole 27 extends through each shoulder 21B and foot 26.

The unit 21 is placed on the rail 22 as shown in Figure 4A, i.e. with the unit angled to the rail and with one edge 23 engaged against one of the clips 12. The unit 21 is then turned on to the rail as indicated by the arrow in Figure 4A until lug 18 of the other clip 12 acts against the other edge 23 to spring the clip over that edge. The unit is then locked to the rail, the edges 23 engaging the inclined faces of the clips 12 so that the unit 21 is biased against the rail 22, as illustrated in Figure 5. When in the locking position, the rail 22 is straddled by the feet 26 which locate the unit with respect to the rail.

Although the unit 21 is retained on the rail 22 by the two clips 12, it can be moved along the rail 22 by the application of a positive force. The unit 21 can be released from the rail 22 by pulling it away with sufficient force to cause the clips 12 to spring outwardly over the rail edges 23.

Alternatively, a small screwdriver can be inserted in the hole shown at 14A in the foot 14 of one of the clips and levered to release that clip from the DIN rail 22.

The unit 21 may alternatively be secured by conventional methods on a flat surface, such as a wall. For that purpose, fixing screws or bolts are passed through the holes 27 and engaged in the mounting sur face.

In the alternative and preferred form of clip shown at 30 in Figure 6, the attach ment part 32 of the clip is similar to that of the clip 12, but there are two feet 33 which extend downwardly from a bar 34 formed integrally with the attachment part 32.

The entire clip 30 is formed in one piece from a leaf spring, as before, and each of the feet 33 is similar to the foot 14 of the clip shown in Figures 1 and 2. The clips are mounted on a unit 31 and the unit 31 is fixed to, and removed from, the rail 22 as previously described. The provision of two resilient feet 33 on each clip provides improved locking of the unit to the rail.

The unit 31 can alternatively be secured by conventional fixing means as before.

WHAT WE CLAIM IS:- 1. An electrical unit having first means capable of receiving fixing members in- tended to enter a flat mounting surface to which the unit is to be secured in position, and second means comprising slots capable of receiving rail-mounting clips separable from the unit for alternatively clipping the unit to a mounting rail.

2. The unit according to claim 1, in which the second means comprises slots on opposite sides of the unit each to receive and to secure a rail-mounting clip.

3. The unit according to claim I or 2, in which the unit comprises spaced shoulders designed to receive between them the mounting rail.

4. The unit according to claim 1, 2 or 3, in which the first means comprises holes in the unit, separate from the slots, for fixing screws or bolts.

5. The unit according to claims 3 and 4, in which the holes, extend through the shoulders.

6. The combination of an electrical unit according to any one of claims 1 to 5, and at least two rail-mounting clips which are separate from the unit but are attachable thereto, and which, when so attached, pro ject beyond the unit and enable the unit to be clipped on to opposite edges of a mounting rail.

7. The combination according to claim 6, in which each clip has an attachment part adapted to be attached to the unit and at least one resilient foot which is angled to grip an edge of a mounting rail.

8. The combination according to claim 7, in which the unit has slots on opposite sides thereof, each to receive a clip, and in which the attachment part of each clip has a resilient tang designed to retentively

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. outwardly, i.e. in the same direction as the tang 16 and then back to form an inclined face 17. The face 17 extends rearwardly to a point behind the plane of the attachment part 13, and is then bent forwardly and sharply to form a lug 18. In Figures 3 and 4, the unit to be fixed is exemplified by an electrical contactor 21 which is to be mounted on and secured to a DIN rail 22 which has parallel lateral edges 23. Normally the rail 22 is secured in position with the plane through the edges 23 vertical, but for convenience is shown in Figure 3 with that plane horizontal. The unit has a mounting face 21A, which is flat over the area of the face of rail 22. Integral side bars 24 extend along the edges of the sides of the unit adjacent the face 21A. A slot 25 is formed between the side of the unit 21 and each bar 24, and opens to the mounting face 21A; each slot can receive a clip 12. When it is required to fix the unit to the DIN rail 22, one of the clips 12 is pushed upwardly through each slot 25, until the resilient tang emerges above the bar and springs outwardly to lock the clip against downward movement. The unit 21 has additionally at least two integral shoulders 21B extending outwardly from the sides. In the construction shown in Figure 3, there is a single shoulder on each side and these shoulders- are located diagonally opposite one another. The shoulders 21B extend beyond the plane of face 21A to form location feet 26 which are spaced apart by the width of the rail 22 between edges 23. A hole 27 extends through each shoulder 21B and foot 26. The unit 21 is placed on the rail 22 as shown in Figure 4A, i.e. with the unit angled to the rail and with one edge 23 engaged against one of the clips 12. The unit 21 is then turned on to the rail as indicated by the arrow in Figure 4A until lug 18 of the other clip 12 acts against the other edge 23 to spring the clip over that edge. The unit is then locked to the rail, the edges 23 engaging the inclined faces of the clips 12 so that the unit 21 is biased against the rail 22, as illustrated in Figure 5. When in the locking position, the rail 22 is straddled by the feet 26 which locate the unit with respect to the rail. Although the unit 21 is retained on the rail 22 by the two clips 12, it can be moved along the rail 22 by the application of a positive force. The unit 21 can be released from the rail 22 by pulling it away with sufficient force to cause the clips 12 to spring outwardly over the rail edges 23. Alternatively, a small screwdriver can be inserted in the hole shown at 14A in the foot 14 of one of the clips and levered to release that clip from the DIN rail 22. The unit 21 may alternatively be secured by conventional methods on a flat surface, such as a wall. For that purpose, fixing screws or bolts are passed through the holes 27 and engaged in the mounting sur face. In the alternative and preferred form of clip shown at 30 in Figure 6, the attach ment part 32 of the clip is similar to that of the clip 12, but there are two feet 33 which extend downwardly from a bar 34 formed integrally with the attachment part 32. The entire clip 30 is formed in one piece from a leaf spring, as before, and each of the feet 33 is similar to the foot 14 of the clip shown in Figures 1 and 2. The clips are mounted on a unit 31 and the unit 31 is fixed to, and removed from, the rail 22 as previously described. The provision of two resilient feet 33 on each clip provides improved locking of the unit to the rail. The unit 31 can alternatively be secured by conventional fixing means as before. WHAT WE CLAIM IS:-

1. An electrical unit having first means capable of receiving fixing members in- tended to enter a flat mounting surface to which the unit is to be secured in position, and second means comprising slots capable of receiving rail-mounting clips separable from the unit for alternatively clipping the unit to a mounting rail.

attach the clip to the unit when so re ceived in a slot.

9. The combination according to claim 7 or claim 8, in which the extremity of the foot or each foot is bent outwardly to form a lug enabling the foot to be released from a mounting rail.

10. The combination according to any one of claims 6 to 9, in which each clip is made integrally from leaf spring.

11. A method of fixing an electrical unit according to any one of claims 1 to 5 to a mounting rail, in which separate clips are attached to the slides of the unit, each clip having at least one resilient foot which is angled to grip the rail edge, the unit is placed on the rail and the foot or feet of each clip is or are urged over the respective edge of the rail.

12. A rail-mountable electrical unit substantially as herein described with reference to the accompanying drawings.

13. The combination of an electrical unit and rail-mounting clips, the combination being substantially as described with reference to the accompanying drawings.