GB2165102A

GB2165102A - Wiring equipment and means for attachment thereof

Info

Publication number: GB2165102A
Application number: GB08500376A
Authority: GB
Inventors: Shiori Fujiyoshi
Original assignee: Jimbo Electric Co Ltd
Current assignee: Jimbo Electric Co Ltd
Priority date: 1981-09-10
Filing date: 1985-01-08
Publication date: 1986-04-03
Also published as: GB2165102B; GB2106722A; GB8500376D0; PH18027A; GB2106722B

Abstract

A wiring appliance which is adapted to be located on the reverse side of a plate of the attachment device which is formed of molded plastics and has an aperture therein for receiving the appliance, has a case body (26), a lid (25) having a frame on its upper face and a connection fitting (27) for joining the case body to the lid, and slot means defined by a projection formed on the fitting or the lid and a projecting portion formed on an external wall of the case body. In operation the slot receives an engaging projection (18) of a support (17) for the appliance when the appliance is located in the aperture. <IMAGE>

Description

1 GB 2 165 102 A 1

SPECIFICATION

Wiring equipment and means for attachment thereof The present invention relates to a wiring appliance designed to be attached to a panel wall either di rectly or through a box embedded therein, and is also concerned with a means for attachment thereof.

In most, cases, the prior art technique for attach ment of wiring appliances such as switches or plug receptacles has made use of a mounting metallic frame and a plate, and has had the disadvantages that it involves a rather complicated mounting ar rangement, and requires laborious assembling steps. Besides, when the plate held in place is not level, the attitude of the mounting frame can only be corrected by virtue of troublesome and time consuming steps. For this reason, it has been pro posed to dispense with the mounting frame and fix the wiring equipment to the plate. According to this proposal, however, it is possible to permit re placement of the wiring equipment alone and use continuous-duty wiring equipment.

The invention relates to an assembly comprising a wiring appliance and an attachment device there for, wherein the attachment device comprises a plate-like element formed of plastics material, the plate-like element having an aperture for receiving the wiring appliance, a support provided adjacent the aperture, the lower end of the support being capable of resilient deformation outwardly of the aperture, an engagement projection provided at said lower end of the support and arranged to 100 project therefrom towards said aperture, and wherein the wiring appliance has slot means pro vided in its external surface and adapted to detach ably receive said engagement projection when the appliance is received in said aperture, said support 105 being provided with detachment means adapted for engagement by a tool such that said engage ment projection can be detached from said slot means by resilient deformation of the lower end of said support.

The invention provides a wiring appliance for an assembly as aforesaid, which appliance comprises a case body, a lid having a frame on its upper face and a connection fitting for joining the case body to said lid, and slot means defined by projection formed on said fitting or said lid and a projecting portion formed on an external wall of said case body, said slot means being cipable of receiving detachably said engaging projection of the support of said attachment device when the wiring appli ance is located in use in said aperture of the at tachment device.

An advantage of the present invention is that it makes it possible to provide a wiring appliance and a means for attachment thereof which can do without such steps as are needed for attaching the mounting frame to the plate in the above de scribed prior art, can be used in common with both a metallic mounting frame and a plastic plate, and can be held in place very simply.

Embodiments of the invention will now be described by way of example and with reference to the accompanying drawings, in which:- Figure 1 is a front view of a means for attach- ment of the wiring appliances according to the present invention, having the right-hand half of its face plate removed; Figure 2 is a sectional view taken along the line 11-11 of Figure 1; 75 Figure 3 is a rear view of the means of Figure 1 Figure 4 is an enlarged, partial section taken along the line 11-11 of Figure 11; Figure 5 is a front view of the wiring appliance according to the present invention; 80 Figure 6 is a side view of the appliance of Figure 5; Figure 7 is a view, similar to Figure 1, showing another embodiment of the attachment means according to the invention; 85 Figure 8 is a rear view of a further embodiment of the attachment means according to the invention; Figures 9 and 10 are partial sections of the embodiments of the detachment means according to the invention; Figures 11 and 12 are front views of further em bodiments of the wiring appliances according to the invention; Figure 13 is a side view of Figure 11; and Figure 14 is a plan view of the metallic mounting frame.

Referring to Figures11 to 3, a plate 1 formed of molded plastics includes a flat plate portion 3 hav ing its front side recessed at 2, leaving a surround ing peripheral edge. Three openings 4, 4 and 4 for attachment of wiring appliances are formed in par allel in the plate portion 3, which is also provided therein with elongated slots 5 for attachment of the plate 1 as well as with slots 7 for attachment of a face plate 6 and slots 9 for supporting a fitting 8 used to mount the plate 1 in a panel wall, not illus trated. The flat plate portion 3 is provided on its re verse side with parting walls 10 adapted to define the respective openings 4, side walls 11 and end walls 12, all of said walls being substantially identical in height with the peripheral edge 13 of the plate 1. One end wall 12 is formed at its lower end with three pairs of stoppers 14 extending inwardly into the respective openings 4.

The opposite end wall 12 has a U-shaped recess 15 in its portions confronting the respective openings 4. Both ends of each depression 15 are flush with the ends of the stoppers 14, and serve as supporting means 16. An elastically deformable sup- port 17 extends from the portion of the flat plate 3 within the depressions 15 towards the reverse side of the plate 1, and has its lower end provided with engaging projections 18 extending from the lower face of the plate 1 toward the opening 4. The upper faces of the projections 18 are slightly lower in height than the supporting means 6. The support 17 is formed with a detechment means which, in the illustrated embodiment, comprises a groove 20, of an Lshape in cross-section, provided in the side opposite to the projections 18. What is shown 2 GB 2 165 102 A at 20a is an upstanding piece.

When, in attachment, a tool or driver 22 is in serted in a space 21 defined between the depres sion 15 and the support 17 into the groove 20 to give a force to the upstanding piece 20a in the di rection shown by an arrow (see Figure 4), the sup port 17 is elastically deformed as shown by broken lines in Figure 4. Excessive deformation and hence breakage of the support is then prevented by the wall of the depression 15.

Figures 5 and 6 are front and side views of the wiring appliance according to the present inven tion, which, in Figure 7, is shown as being attached to the plate 1. The wiring appliance shown gener ally at 23 includes a case body 26 joined by means 80 of a fitting 27 to a lid 25 having on its upper face a frame of a rectangular shape in cross-section. The lid 25 is provided on both its sides with lugs 28 and 28, and the base body 26 is provided on both its sides with ribs 29 and 29. These lugs and ribs then form together slots 30 on both sides of the case body 26. The lower portions of the ribs 29 are inclined at 31 for the reasons to be given later.

The operation for attachment of the wiring appli ance 23 to the plate 1 will now be explained. As the case body 26 of the appliance 23 is inserted into the opening 4 from above it, the inclined por tions 31 of the case body 26 first abut upon the stoppers 14 of the said one end wall 12 and the engaging projections 18 of the said other end wall 95 12 of the opening 4, and the support 17 and the projections 18 undergo elastic deformation in their outward direction, as thown in Figure 4 by broken lines. When the ribs 29 of the case body 26 then go past the stoppers 14 and the engaging projec- 100 tions 18, the engaging projections 18 engage within the slot 30 of the case body 26 due to the elastic restoration of the support 17 and the engag ing projections 18, while the stoppers 14 engage within the opposite slots 30. In this way, attach- 105 ment of the wiring appliance 23 is completed. The wiring appliance 23 can surely be mounted on the plate 1, since the lower faces of the lugs 28 of the lid 25 abut upon the stoppers 14 and the support ing means 16 of the engaging projections 18, and 110 the circumference of the lid 25 comes in contact with the parting walls 10 and the side walls 11.

After given wiring is applied with the appliance 23, the plate 1 is screwed onto the embedded box through the slots 5. The faced plate 6 is then elasti- 115 caNy fitted at its legs 6a into the slots 7, and held in the recess 2. When the embedded box is on the tilt, the position of the plate 1 can be corrected, since the elongated slots are of sufficient size.

To remove the wiring appliance 23 from the plate 1, the faced plate 6 is first detached from the recess 2 to remove the plate 1 from the embedded box. A driver or other tools 22 is then inserted into the L-shaped groove 20 from the space 21 between the depression 15 and the support 17 to give a force to the upstanding piece 20a in the outward direction, as shown in Figure 4, whereby the sup port 17 is elastically deformed as shown by the ar row and the engaging projections 13 are separated from the slots 30. Thereafter, the appliance 23 is 2 detached from the opening 4. While the aforesaid embodiment has been described as providing the said one end wall 12 with the elastically deformable support 17 having the engaging projections 18, such supports may be formed on both end walls.

In the embodiment illustrated, the wires are detached from the wiring appliance 23 followed by removal of it from the plate 1. When two or more wiring appliances are connected to each other by way of cross lines, however, it is advantageous to remove simultaneously the appliance from the plate 1 in a state where the lines remain intact. To this end, short tongue piece 10a is formed on the end wall 12 of the parting wall 10.

Figure 8 illustrates an embodiment in which a to tal of six wiring appliances 23 are attached to a single plate la in two rows. A longitudinal partition 12a is provided in the center of the plate for the end wall 12, and formed on its right and left sides with two stoppers 14, 14 for each opening 4a. A support 17 having engaging projections 18 is formed in a depression 5 confronting the respec tive stoppers 14.

Figure 9 shows another embodiment of the de- tachment means for the projections 18. A protru- sion 33 is located on the intermediate portion of the L-shaped groove 20 in the support 17, and depends from the flat plate portion 3. When the support 17 is too largely spaced away from the upstanding piece 20a of the groove 20 in the absence of such a protrusion, there is a fear that unsatisfactory elastic deformation of the support 17 may be caused, or the support 17 of the upstanding piece 20a may be damaged at the time when an excessive force is applied. With the arrangement wherein the protrusion 33 is located on the immediate portion of the groove 30, however, the support 17 can be deformed with a slight force exerted by insertion of the driver 22 in between the protrusion 33 and the upstanding piece 20a of the groove 20 with no risk of damaging them. Figure 10 shows a further embodiment of the detachment means, in which a small detachable piece 34 depends from the support 17 without forming the L-shaped groove therein. With this arangement, the engaging projections 18 can easily be detached from the slot 30 by permitting outward elastic deformation of the support 17 by inserting the driver 22 in between the wall of the case body 26 and the detachable 34. This detachment means is advantageous in that the manufacturing of molds can be eflected at very low costs, since this means takes up a smaller space as compared with that using an L-shaped groove. 120 Figures 11 and 12 show another embodiment of the wiring appliance 23, in which connecting pieces 35 are formed on the fitting 27 for joining the case body 26 to the lid 25 in such a manner that they are contiguous to the sides of the frame 24. The embodiment is similar to that of Figure 5 except that grooves 36 are provided. The wiring appliance 23 shown in Figure 12 is identical with that of Figure 11 except that the lugs 28 have a smaller thickness, and the ribs 29 of the case body 26 have a height corresponding to the thickness of 3 GB 2 165 102 A 3 the lid 25. The thus constructed appliance 23 can be mounted on the plate 1 in a way similar to that used in the foregoing embodiment, and can be attached to conventional metallic frames as well.

The metallic mounting frame generally shown at 36 will now be explained with reference to Figure 14. This frame includes therein openings 37 for at tachment of the wiring appliances. Each opening is formed in its one side with a slot 38. A narrow por tion 39 is then defined between the opening 37 and the edge of the slot opposite thereto. A T shaped piece 40 is formed on the said edge, ex tending into the slot 38, and a protrusion 39a is formed on the edge of the opening 37 opposite to the narrow portion 39. To mount the wiring appli ance 23 on the frame 36, the frame 24 of the appli ance is inserted into the opening 37, while the protrusion 39a is caused to engage within the groove 36 in one connecting piece 35 to forcedly insert the driver into the slot 38, whereupon the 85 piece 40 is forced toward the opening 37. As a re sult of the deformation of the central portion of the narrow portion 39, the piece 40 is inserted into the groove 36 in the connecting piece 35. In this way, attachment of the wiring appliance is completed. 90 To remove the appliance 3 from the frame 36, an outward force is applied to a fug 40a of the piece by means of a driver or other tool to cause out ward restoration of the narrow portion 39, whereby the portion is drawn out of the groove 36.

As described above, the arrangement according to the present invention can do without any steps of attachment of the plate to the mounting frame, as is the case with the prior art, and permits the wiring appliance to be attached easily and surely 100 to the plate by a single operation, resulting in sub stantial increases in the efficiency of wiring opera tion. Attachment or detachment of the wiring appliance can be effected only by removal of the faced plate in a state where the plate remains at tached to the wall. Besides, maintenance and re pair of the wiring appliance is also effected easily.

Since only the engaging projections extend from the lower face of the plate, are of very short length, and are fitted into the underside of the lid of the wiring appliance, there is an ample space between the embedded box and the engaging pro jections. This assures that, even when the box is on the tilt, the attitude of the plate can be kept in proper conditions. Furthermore, the molds for forming the plate can be manufactured at low costs, resulting in a drop of the production cost.

The wiring appliance can be used in common with both a plastic-made plate and a metallic mounting frame in a simple manner.

Claims

1. A wiring appliance, which applicance com prises a case body, a lid having a frame on its up per face and a connection fitting for joining the case body to said lid, and slot means defined by a projection formed on said fitting or said lid and a projecting portion formed on an external wall of said case body, said slot means being capable of receiving detachable said engaging projection of the suport of said attachment device when the wir ing appliance is located in use in said aperture of the attachment device.

2. A wiring appliance as claimed in Claim 1, wherein two projections are formed on said fitting or said lid and cooperate with respective projecting portions formed on an external wall of said case body to define two spaced slots for receiving two spaced engagement projections provided on the support of said attachment means.

3. A wiring appliance as claimed in Claim 1 or Claim 2 having at least one projection provided on said fitting or said lid and at least one projecting portion provided on external walls of said case body at each of a pair of opposite ends of the appliance to define slot means at each end thereof.

4. A wiring appliance as claimed in any of Claims 1 to 3, wherein said projecting portion on the case body is provided with a ramp surface at its lower end to assist engagement of the appliance in said aperture in said attachment device by causing resilient deformation of the lower end of said support thereof.

5. A wiring appliance as claimed in any of Claims 1 to 4 for an assembly as claimed in Claim 2, which apliance has a connecting piece mounted by said fitting to be contiguous with an end wall of said frame and being provided with a groove herein for receiving said narrow portion of said metallic mounting plate when that narrow portion is forcibly deformed as aforesaid.

6. A wiring appliance substantially as hereinbefore described with reference to, and as illustrated in, Figures 5 and 6, or Figure 12, or Figures 11 and 13, of the accompanying drawings.

Printed in the UK for HMSO, D881 8935, 2186, 7102. Published by The Patent Office, 25 Southampton Buildings, London, WC2A lAY, from which copies may be obtained.