GB2115614A

GB2115614A - Box for electrical components

Info

Publication number: GB2115614A
Application number: GB08204354A
Authority: GB
Inventors: David William Bramwell
Original assignee: EGATUBE Ltd
Current assignee: EGATUBE Ltd
Priority date: 1982-02-15
Filing date: 1982-02-15
Publication date: 1983-09-07
Also published as: GB2115614B

Abstract

Boxes for electrical components are provided with elongate grooves (3) to receive self-tapping screws 41 for securing the components in the box. The grooves may extend above or below the bottom of the box and the upper edges may be bevelled to receive more than one size of screw. The grooves may be formed in integral channels 4. <IMAGE>

Description

SPECIFICATION Box for electrical components This invention relates to boxes intended to contain electrical circuit elements such as terminals, relays and lighting components.

According to an aspect of the invention there is provided a box for electrical components of which an interior surface is provided with at least one elongate groove dimensioned to receive and engage self-tapping screws for securing electrical components within the box. The groove may be such that a screw may be engaged at substantially any point along the groove.

The grooves may be positioned on the bottom of the box and may form a pattern extending over most of the area of the bottom so that screws may be inserted at a wide variety of locations in the box, allowing a high degree of flexibility in locating components therein. The grooves may be formed either by ridges extending above the bottom (i.e. extending into the box interior) or by channel portions extending below the bottom. In the latter case the walls of the box may extend below the bottom and the lower exterior surfaces of the channel portions may be substantially flush with the lower edges of the walls of the box.

The grooves may be dimensioned so as to receive a standard self-tapping screw, such as No.

6 screw in such a manner that the screw thread will bite the interior walls of the grooves and provide a screw fastening for components engaging the screw. The lower portion of the grooves may be parallel sided so that the lower portion is of uniform width but the upper edges of the grooves may be bevelled, providing an upper portion of increased width capable of receiving a larger screw, for example, a No. 8 self-tapping screw. This arrangement allows more than one size of screw to be used.

The box button may be provided with holes to receive screws for mounting the box on a wall or other support surface.

One type of box may be closed with a lid attached to the body of the box by screws and a gasket may be provided between the lid and box body to render the box dust-proof and moistureproof in order to protect components mounted inside. Wires may be run into the box through holes in the bottom or walls. The holes may be drilled or formed by pushing out knock-out portions of small thicknesses provided in the walls or bottom.

Another type of box comprises two half-boxes of similar construction which are held together by screws with their respective upper edges abutting face-to-face: in this embodiment both half-boxes may be provided with grooves so that components can be mounted on either half. Wires can enter the box so formed by holes in the bottoms or walls of the half-boxes. Alternatively the abutting edges may be such that when the half-boxes are assembled together a gap between the edges is provided on part of the periphery of the boxes, the gap being wide enough to allow wires to pass through. The gap may be occupied by a pad of resilient material mounted on at least one of the edges to close the gap and render the box dust-proof while allowing passage of wires through the gap.

The boxes may be made by moulding of polyvinylchloride, a polycarbonate or other plastics material.

Boxes according to embodiments of the invention will now be described by way of example, with reference to the accompanying drawings, in which:~ Figure 1 is a perspective view of a box and lid to contain electrical circuit elements, the bottom of the box being provided with slots, Figure 2 is a cross-section of a wall and part of the bottom of the box of Figure 1, one of the slots being shown in longitudinal cross-section, Figure 3 is another cross-section of a wall and part of the bottom of the box of Figure 1, one of the slots being shown in transverse cross-section, Figures 4 and 5 are perspective views of another type of box, shown open and closed respectively.

Referring to Figures 1 and 2 an open-topped box has walls 1 of height 54 mm and thickness 3.5 mm and a flat bottom 2 of thickness 3.5 mm, the lower surface of the bottom being raised above the lower edge of the wall by a distance x of 8 mm.

The bottom is provided with a plurality of slots 3 defined by channel portions 4 extending below the bottom, the lower surfaces of the channel portions being almost flush with the lower edges of the walls. A knock-out portion 40 is provided in the middle of the bottom. The slots are of uniform width and are shown in cross-section in Figure 3.

The depth of each slot is 9.5 mm, the lower part of the slot is parallel-sided and of width 2.7 mm whereas the upper part of the slot has edges bevelled to 150 from the vertical. These slot dimensions allow a standard No. 6 self-tapping screw 41 to be screwed into and securely held at any point along the slot.

As shown in Figure 1 the slots are arranged to extend from the centre to the sides of the bottom in different directions so that they form a pattern extending over most of the area of the bottom.

This arrangement allows a component to be secured to the bottom of the box at substantially any position by means of a screw inserted into the most convenient slot.

The bottom of the box is provided with means for securing the box to a wall or the like. These means comprise well portions 5 extending below the lower surface of the bottom, as shown in Figure 3, the lower surface of the well portion being flush with the bottom edge of the wall. The well portions 4 in number, each have a hole 6 of 4.5 mm diameter to receive a No. 8 woodscrew 7 or 4 mm bolt by which the box may be attached to a wall. The screw or bolt may be provided with a skid washer and a seal washer in conventional manner.

The box may be closed by a lid 8. In order to render the box dust-proof after assembly the upper edge of wall 1 is provided with a shoulder 9 extending around the whole periphery of the wall.

The lid has a downwardly extending edge flange 10 to engage the upper edge of the wall and the engaging surface of the flange has an outer lip 11 to extend into the shoulder 9, an inner lip 12 of lesser depth than lip 11 and a gasket 13 of resilient material between the lips to abut the edge 14 of the wall.

The lid is held against the wall of the box by threaded bolts 15 which extend through holes in the lid and engage threaded inserts 16 mounted in holes formed in pillars 17 projecting inwardly of the walls adjacent the corners of the box. A gasket seal 18 is provided around each bolt 15 and the bolt is provided with a skid washer and seal washer adjacent the head. Entry of dust to the box past the bolt is thus prevented.

Wiring may be led into the box through holes provided in the sides or bottom. Such holes may be made by drilling or the box wall and/or bottom may comprise knock-out portions such as 40 which are pressed out as required to provide the necessary openings.

The box shown in Figures 4 and 5 comprises two identical half boxes which are joined together edge-to-edge to form a closed box. The bottom 23 of each half-box is 2.5 mm thick and has a lower surface 1.5 mm above the lower edge of the wall 24 of the half-box. The upper (inside) surface of the bottom 23 carries upstanding ridges 25 extending 4.5 mm above the inside surface forming grooves 26. The lower surface of the bottom 23 has ribs 27 opposite the grooves extending beyond the bottom by 1 mm. The grooves have a depth of 7 mm and are parallel sided at their lower part with a width of 4 mm, the upper ends of the grooves being bevelled. These dimensions allow the grooves to securely engage a No. 6 self-tapping screw which may be inserted in and securely engage the groove sides at any point on the grooves. A component may thus be supported within the box in a wide choice of positions.

The upper edge of the wall has an outwardly extending peripheral flange 28 having holes 29 to receive bolts 21 to clamp the two half-boxes together. Holes 29 of the lower half-box shown in Figure 4 have female threaded inserts to engage these bolts which are inserted through holes 29 of the upper half-box. On both of the shorter sides of the box the flange has an outer upstanding lip of which one has an internal shoulder 31 and the other an external shoulder 32. When two identical half-boxes are fitted together as shown in Figure 5 the lip having an internal shoulder of one flange engages the lip having an external shoulder of the other flange so that the lips together provide a dust-proof seal.

When the half-boxes are clamped together in this way there is a gap about 3 mm wide between respective flanges 28 on the longer sides of the box and to fill this gap each of the flanges on the longer sides is provided with a pad 32 of compressible resilient material such as a foam rubber, the pad being about 1.5 mm thick. The abutting pad of the respective half-boxes provide a dust-tight seal but as the pad material is deformable wires may pass from the exterior to the interior of the box through the gap occupied by the pads, the abutting pads holding the wires in place. This feature allows wires to be passed into the box at any longitudinal position along either of its longer sides.

The bottom of each half-box is also provided with circular upstanding ridges 33 defining circular holes 34 of similar width to grooves 26 to receive self-tapping screws; however these holes are of greater depth (15 mm) to receive longer screws as required. The bottom is also provided with knock-out portions 35 allowing screws to be passed through the bottom to mount the half-box on a wall or the like.

Both the boxes described above may be made of a known plastics material such as polyvinyl chloride or a polycarbonate and may be formed to shape by moulding.

The boxes described are capable of containing a a wide variety of electrical and electronic components and assemblies which are secured inside the boxes by screws engaging the grooves.

The boxes have a neat appearance and are easily mounted in any location. The grooves are adapted to receive a standard No. 6 self-tapping screw but as they are slightly wider at the mouth they can also receive a wider No. 8 screw if required.

Claims (filed on 9 Feb 1983) 1. A box for electrical components of which an interior surface is provided with at least one elongate groove dimensioned to receive and engage self-tapping screws for securing electrical components within the box.

2. A box according to Claim 1, in which the lower portion of the groove is parallel sided and the upper edges of the groove are bevelled so that the groove can receive and engage more than one size of screw.

3. A box according to Claim 1 or 2, in which the groove is defined by a pair of ridges inside the box extending above the bottom of the box.

4. A box according to Claim 1 or 2, in which the groove is defined by a channel extending below the bottom of the box.

5. A box according to Claim 4, in which the walls of the box extend below the bottom and the lower exterior surface of the channel is substantially flush with the lower edge of the walls.

6. A box according to any preceding claim having a plurality of elongate grooves forming a pattern extending over substantially the whole of the bottom of the box.

7. A box according to any preceding claim, comprising two similar half-boxes which may be fastened together with the upper edges of their respective walls abutting each other.

8. A box according to Claim 7, provided with a gap between parts of the upper edges of the

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. render the box dust-proof after assembly the upper edge of wall 1 is provided with a shoulder 9 extending around the whole periphery of the wall. The lid has a downwardly extending edge flange 10 to engage the upper edge of the wall and the engaging surface of the flange has an outer lip 11 to extend into the shoulder 9, an inner lip 12 of lesser depth than lip 11 and a gasket 13 of resilient material between the lips to abut the edge 14 of the wall. The lid is held against the wall of the box by threaded bolts 15 which extend through holes in the lid and engage threaded inserts 16 mounted in holes formed in pillars 17 projecting inwardly of the walls adjacent the corners of the box. A gasket seal 18 is provided around each bolt 15 and the bolt is provided with a skid washer and seal washer adjacent the head. Entry of dust to the box past the bolt is thus prevented. Wiring may be led into the box through holes provided in the sides or bottom. Such holes may be made by drilling or the box wall and/or bottom may comprise knock-out portions such as 40 which are pressed out as required to provide the necessary openings. The box shown in Figures 4 and 5 comprises two identical half boxes which are joined together edge-to-edge to form a closed box. The bottom 23 of each half-box is 2.5 mm thick and has a lower surface 1.5 mm above the lower edge of the wall 24 of the half-box. The upper (inside) surface of the bottom 23 carries upstanding ridges 25 extending 4.5 mm above the inside surface forming grooves 26. The lower surface of the bottom 23 has ribs 27 opposite the grooves extending beyond the bottom by 1 mm. The grooves have a depth of 7 mm and are parallel sided at their lower part with a width of 4 mm, the upper ends of the grooves being bevelled. These dimensions allow the grooves to securely engage a No. 6 self-tapping screw which may be inserted in and securely engage the groove sides at any point on the grooves. A component may thus be supported within the box in a wide choice of positions. The upper edge of the wall has an outwardly extending peripheral flange 28 having holes 29 to receive bolts 21 to clamp the two half-boxes together. Holes 29 of the lower half-box shown in Figure 4 have female threaded inserts to engage these bolts which are inserted through holes 29 of the upper half-box. On both of the shorter sides of the box the flange has an outer upstanding lip of which one has an internal shoulder 31 and the other an external shoulder 32. When two identical half-boxes are fitted together as shown in Figure 5 the lip having an internal shoulder of one flange engages the lip having an external shoulder of the other flange so that the lips together provide a dust-proof seal. When the half-boxes are clamped together in this way there is a gap about 3 mm wide between respective flanges 28 on the longer sides of the box and to fill this gap each of the flanges on the longer sides is provided with a pad 32 of compressible resilient material such as a foam rubber, the pad being about 1.5 mm thick. The abutting pad of the respective half-boxes provide a dust-tight seal but as the pad material is deformable wires may pass from the exterior to the interior of the box through the gap occupied by the pads, the abutting pads holding the wires in place. This feature allows wires to be passed into the box at any longitudinal position along either of its longer sides. The bottom of each half-box is also provided with circular upstanding ridges 33 defining circular holes 34 of similar width to grooves 26 to receive self-tapping screws; however these holes are of greater depth (15 mm) to receive longer screws as required. The bottom is also provided with knock-out portions 35 allowing screws to be passed through the bottom to mount the half-box on a wall or the like. Both the boxes described above may be made of a known plastics material such as polyvinyl chloride or a polycarbonate and may be formed to shape by moulding. The boxes described are capable of containing a a wide variety of electrical and electronic components and assemblies which are secured inside the boxes by screws engaging the grooves. The boxes have a neat appearance and are easily mounted in any location. The grooves are adapted to receive a standard No. 6 self-tapping screw but as they are slightly wider at the mouth they can also receive a wider No. 8 screw if required. Claims (filed on 9 Feb 1983)

1. A box for electrical components of which an interior surface is provided with at least one elongate groove dimensioned to receive and engage self-tapping screws for securing electrical components within the box.

8. A box according to Claim 7, provided with a gap between parts of the upper edges of the respective walls when the half-boxes are fastened together to allow passage of wires.

9. A box according to Claim 8, in which the gap is provided with a pad of resilient material to render the box dust-proof while allowing passage of wires through the gap.

10. A box for electrical components, substantially as hereinbefore described with reference to Figures 1,2 and 3 or Figures 4 and 5 of the accompanying drawings.