GB2426638A

GB2426638A - Dry lining box with rotatable clamping means

Info

Publication number: GB2426638A
Application number: GB0510813A
Authority: GB
Inventors: John Robert Harrison; Tom Doherty; Daniel John Richardson
Original assignee: Novar ED&S Ltd
Current assignee: Novar ED&S Ltd
Priority date: 2005-05-26
Filing date: 2005-05-26
Publication date: 2006-11-29
Also published as: GB0510813D0

Abstract

A dry lining box has a body 30 and a clamping means 50. The clamping means is rotatable about an axis into the box (such as hinge sleeve 38) so that it can be inside the box when the box is fitted or outside the box to clamp it in position. For a thin wall, the box is clamped using the abutment surface 105 of spacer boxes 100; with a thicker wall, spacers 100 remain in the box and the wall is clamped against shelf 62.

Description

DRY LINING BOX

FIELD OF THE INVENTION The present invention relates to a dry lining box for mounting in an aperture provided in a wall. In particular, the present invention relates to clamping means for clamping the dry lining box to the wall.

BACKGROUND OF THE INVENTION Dry lining boxes are used for mounting electrical points to cavity wall structures, dry lining partitions, plasterboard and false wall environments. For example, dry lining boxes may be used to mount mains electricity sockets and lighting switches into such walls. Figure 1 shows a known dry lining box mounted in an aperture of a cavity wall to provide an electrical socket. The box may be pushed into the aperture such that it extends into the cavity of the two-part wall. A flange extends around an open front face of the box. The flange engages the front of the wall to locate the box and stop the box from moving too far into the aperture of the wall in the direction shown by arrow X. Electrical cables extend through the cavity and are connected to the electrical socket through the back of the box. The electrical socket is provided by a front plate wiring device that is mounted on the open front face of the box. The box thus encloses the electrical components which connect the electrical cables to the connections on the front plate wiring device. The front plate may be attached to the box by means of one or more screws. Many different types of front plate wiring devices and/or fittings are currently available for dry lining boxes. The front plate wiring device of Figure 1 covers the same wall area as the flange of the box, although the front plate wiring device may be larger to ensure the cover is hidden from view. The box comprises clamping means, indicated at "A", to secure the dry lining box and front plate wiring device in position on the wall. The clamping means press on the back surface of the wall, such that the wall is sandwiched between the flange and the clamping means. Once the box has been fully inserted into the aperture, the clamping means prevents the box from coming out of the aperture in the direction shown by arrow Y. During installation of the box, the clamping means must reside within the box to ensure they do not interfere with the push fit of the box into the wall. Hence, the clamping means have to be pushed out from within the box once the box is in position. One known arrangement is to provide the clamping means on hinges that extend along the width of the box. The hinge parts contain a screw thread for cooperating with the screws of the front plate wiring device. Hence, as the screws are tightened, the clamping means is urged into the back surface of the wall. Generally, all known clamping means are small and awkward to operate within the confines of the box itself.

SUMMARY OF THE INVENTION Against this background, and from a first aspect, the present invention resides in a dry lining box for mounting in a wall, comprising a body and clamping means, the body comprising an open front face for receiving a front plate wiring device, and a side provided with an aperture for receiving the clamping means that are operable to secure the dry lining box to the wall. The clamping means is provided with a first abutment surface that faces the front face of the dry lining box. This abutment surface is for abutting against the back of the wall to which the dry lining box is to be mounted. A further abutment surface will abut the front of the wall to clamp the dry lining box in place. This further abutment surface may be provided by the dry lining box, e.g. a peripheral flange, or may be provided by a front plate wiring device that attaches to the front of the dry lining box. The clamping means are rotatably mounted adjacent the aperture so as to rotate about an axis that extends substantially in the direction of the depth of the dry lining box from a first position to a second position. In the first position, the first abutment surface resides within the dry lining box. This is to allow the dry lining box to be pushed into a hole in a wall of corresponding size without the clamping means fouling. In the second position, the clamping means projects through the aperture such that at least part of the first abutment surface resides outside of the dry lining box. In this position, the first abutment surface may be placed in contact with the back of the wall. In this way, a relatively large clamping means is provided that is robust and easy to handle, in contrast to the prior art described above. Advantageously, the hinge may be arranged to allow the clamping means to move along the hinge axis relative to the body. Due to the orientation of the hinge along the depth of the dry lining box, this movement is conveniently towards the front face of the dry lining box. Hence, the first abutment surface may be moved into contact with the wall. This is useful where, for example, the position of the body relative to the wall is fixed by a flange or the like. Several methods of effecting movement of the clamping means are possible. A preferred arrangement is to provide the clamping means with a screw thread that receives a screw. The screw may bite against either a surface provided at or near the open face of the body (e.g. a flange) or may bite against a front plate wiring device mounted to the dry lining box. The screw thread may be integrally formed with the clamping means or may be provided by a nut retained by the clamping means. Optionally, the axial movement of the hinge may be provided by having a hinge formed of a post received within a sleeve, the post having an enlarged section that is received within an enlarged bore of the sleeve, the length of the enlarged bore being greater than the length of the enlarged section of the post. A groove may be provided in the enlarged section to allow it to contract as it is passed to the enlarged bore. Alternatively, the sleeve may be provided with means to allow it to expand to accommodate the enlarged section as it passes through to the enlarged bore. Where a hinge comprising a sleeve and post is used, the sleeve may be provided by the body and the post by the clamping means, or vice versa. The sleeve may have an open section, wherein an edge of the open section provides a stop for limiting rotation of the clamping means. Preferably, this stop sets the first position where the clamping means resides within the body. A stop may be provided on the clamping means to limit rotation of the clamping means, preferably setting the second position where the first abutment surface is outside of the body. This stop may be a tab or the like that overlaps with a section of the body adjacent the aperture. Optionally, a fastener may be provided to secure the clamping means in the second position. The fastener may be a catch that catches on a section of the wall adjacent the aperture.The catch may be resilient so that it deflects as the clamping means moves into the aperture and then snaps into position against the body. Optionally, the first abutment surface is provided by a shelf that projects from the clamping means. The clamping means may further comprise a spacer that provides a second abutment surface. The spacer may attach to the remainder of the clamping means such that the second abutment surface faces the open front face of the dry lining box. Advantageously, the spacer may be attached to the clamping means such that it is positioned on the first abutment surface. Optionally, the clamping means may be provided with a hole that allows the spacer to fall from the first abutment surface into the interior of the body. The aperture may be positioned in the side of the body such that it is close to the front face of the dry lining box. Preferably, the aperture is positioned such that some dry lined walls will have a thickness sufficient for the wall to overlap with the aperture. The first abutment surface may be positioned such that it protrudes through the aperture at a position always behind such walls. The thickness of the spacer may be chosen such that it fits behind thinner types of dry lined wall, but overlaps thicker types. Thus, when the clamping means are moved to the second position, the spacer is forced from the first abutment by a thicker wall. From a second aspect, the present invention resides in a method of partially installing the above dry lining box, comprising pushing the dry lining box into a hole provided in a wall such that a portion of the wall overlaps the aperture in the body's side, and pushing the clamping means to rotate the clamping means to the second position thereby causing the spacer to strike the overlapping portion of wall such that the spacer is pushed through the hole into the interior of the body. Optionally, the spacer comprises two blocks connected by a resilient link. A pair of correspondingly sized holes may be provided in the clamping means. Catches may be provided on the blocks to secure the blocks in position on the first abutment surface. The catches may pass through the holes as the blocks move together by virtue of the resilient link. The blocks will then spring apart so that he catch catches on the side of the holes. From a third aspect, the present invention resides in the combination of any of the above dry lining boxes and a front plate wiring device for attaching to the dry lining box. Other preferred but optional features of the present invention are defined in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings in which: Figure 1 is a prior art dry lining box for mounting in an aperture of a wall; Figure 2 is an exploded view of a dry lining box according to an embodiment of the present invention; Figures 3 to 6 are perspective views of the dry lining box of Figure 2 installed in a wall and showing the position of hinged clamping means through various stages of closure; Figure 7 is a perspective view of an assembled clamping means; and Figure 8 is a side view of the dry lining box of Figure 1 installed in walls of varying thicknesses.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS A dry lining box 10 suitable for installation in a wall 20 such as a cavity wall structure, a dry lining partition, plasterboard or other false wall environments is shown in Figure 2 in exploded form. The dry lining box 10 is suitable for use with standard front plate wiring devices such as electrical sockets and light switches. Front plate wiring devices are not shown in Figures 2 to 8 as they attach in conventional fashion, as will become clear from the following description. The dry lining box 10 comprises a body 30 and two identical clamping means 50, each clamping means 50 comprising a door 60, a nut 90 and a pair of linked spacer boxes 100. The door 60 is attached to the body 30 of the dry lining box 10 by a hinge 61. The body 30 of the dry lining box 10 comprises a square front face defined by a peripheral flange 31, but is otherwise open to allow access to the interior of the dry lining box 10. The flange 31 is provided to abut against the front face 21 of the wall 20 to which the dry lining box 10 is mounted, as per the prior art described above. The body 30 also comprises four sides 32-35 and a back 36. The sides 32-35 are rectangular such that the body 30 is slightly deeper than it is tall or wide. The sides 32-35 form matching, opposed pairs. One pair 33 and 35 have central apertures 37, whereas the other pair 32 and 34 do not. The central apertures 37 are provided to accommodate the hinged clamping means 50. As mentioned above, each clamping means 50 comprises the door 60, the nut 90 and the pair of spacer boxes 100. Each clamping means 50 assembles such that the pair of linked spacer boxes 100 sit on a shelf 62 that extends from the door 60 and the nut 90 is received in a housing 63. Dealing first with the spacer boxes 100, the spacer boxes 100 are joined by a thin U-shaped link 101 that allows the spacer boxes 100 to flex towards each other. The spacer boxes 100 are located on the shelf 62 by pushing the spacer boxes 100 through a pair of holes 64 provided in the door 60 from behind, that is as indicated by the arrows B in Figure 2. The link 101 between the spacer boxes 100 rests against the wall 65 separating the holes 64 when the spacer boxes 100 are correctly in position. A pair of tabs 102 and 103 are also provided to locate the spacer boxes 100 in the correct position: one tab 102 extends upwardly from one spacer box 100 and the other tab 103 extends downwardly from the other spacer box 100, so as to rest against the door 60 adjacent the holes 64.To hold the spacer boxes 100 in position, their outer side has a prism-shaped pip 104 whose flat face catches on the side of the hole 64 when the spacer boxes 100 are pushed into position. The angled face causes the spacer boxes 100 to flex together as they are pushed through the hole 64, such that the spacer boxes 100 clip into position with a snap. The dry lining box 10 is intended to be supplied with the spacer boxes 100 already in place on the shelf 62. Returning now to the nut 90, its housing 63 is only slightly larger than the nut 90 so that the nut 90 may not rotate in its housing 63 and has little room for translational movement. The housing 63 has a central bore 66 sized to receive a screw onto which the nut 90 threads. The U-shaped link 101 that joins the spacer boxes 100 sits immediately below the housing 63, and is U-shaped to ensure it passes around the end of a long screw that may project beyond the nut 90. The body 30 of the dry lining box 10 has a pair of hinge sleeves 38 defining half of the hinge 61 that joins the body 30 and the clamping means 50. The hinge sleeve 38 is sized to receive a hinge post 67 that extends from a side of the door 60. The hinge sleeves 38 are formed integrally with the body 30, and are located to extend from the back 36 along the depth of the dry lining box 10 adjacent the edge of one of the central apertures 37. The hinge sleeve 38 has a lower enclosed portion 39 with includes a section with an enlarged bore to receive an enlarged foot 68 of the hinge post 67. The foot 68 of the hinge post 67 is provided with a groove 69 to allow the foot 68 to flex as it is passed through the narrower part of the enclosed portion 39 of the hinge sleeve 38.The upper part 40 of the hinge sleeve 38 is partially open to allow the door 60 to rotate from a closed position where it is received in the central aperture 37 and an open position where the door 60 resides within the box 10. The open part 40 of the hinge sleeve 38 provides a stop to limit rotation of the door 60 into the body 30. A stop is also provided by a tab 70 on the unhinged side of the door 60 that abuts against the side of the central aperture 37 when the door 60 is in the closed position, thereby preventing the door 60 from moving beyond the closed position. The door 60 is held closed by a catch 71 that comprises a U-shaped flexible portion 72 that extends from the unhinged side of the door 60, adjacent the tab 70, the ends with a shoulder 73 that locks against a strip 41 provided on the edge of the central aperture 37. The dry lining box 10 is intended to be supplied with the door 60 free to rotate rather than being fixed in the closed position. The enlarged bore in the lower part 39 of the hinge sleeve 38 has a greater height than that of the enlarged foot 68 of the hinge post 67, thus allowing the clamping means 50 to move through translation relative to the body 30. As the axis of the hinge 61 is conveniently aligned with the depth of the dry lining box 10, the clamping means 50 can move closer to and further from the front face of the dry lining box 10. This movement allows the spacer boxes 100 to be moved into contact with the back 22 of the wall 20 to which the dry lining box 10 is mounted, as follows. The front plate wiring device attaches to the dry lining box 10 via two screws: these screws cooperate with the nuts 90 of the clamping means 50 when the doors 60 are in their closed position. Thus, as the screws are tightened, the clamping means 50 is pulled towards the front plate wiring device because the nut 90 cannot move in its housing 63. Eventually the wall 120 becomes clamped between the flange 31 of the dry lining box 10 and the tops 105 of the spacer boxes 100. This embodiment of the present invention provides a distinct advantage in ease of installation to walls 20 of varying thicknesses. Figures 8a to 8c show the dry lining box 10 installed in walls 20 having thicknesses of 10mm, 20mm and 30mm. Figure 3c shows that the shelves 62 themselves may be used to clamp against the back 22 of the wall 20. Figures 3a and 3b show thinner walls 20 where the tops 104 of the spacer boxes 100 clamp against the wall 20. Thus, the spacer boxes 100 effectively act as spacers: without the spacer boxes 100, the screws would require substantial tightening to move the clamping means 50 far enough for the shelf 62 to contact the wall 20. This advantageously reduces installation time. Moreover, as will be appreciated from the installation procedure described below, the installer need not worry as to whether or not the spacer boxes 100 should be used to obtain the correct spacing because selection is performed automatically. As described above, the dry lining box 10 is supplied with the clamping means 50 attached to the body 60 of the dry lining box 10 and the clamping means 50 are allowed to rotate freely on their hinges 61. The spacer boxes 100 are already clipped into place. An installer will install the dry lining box 10 into a correspondingly sized hole in a wall 20 by pushing the dry lining box 10 into the hole, with the back 36 of the dry lining box 10 entering first, until the underside of the flange 31 meets the wall 20. The clamping means 50 should be in their open position such that the spacer boxes 100 and the shelves 62 do not foul on the sides of the hole in the wall 20 as the dry lining box 10 is pushed into position. However, it does not matter if they are not in the correct position because of the action of three angled guide members 74 provided beneath each shelf 62.The angled guide members 74 will act to push the clamping means 50 into the dry lining box 10 as the dry lining box 10 is pushed into the wall 20. Thus, the doors 60 are forced to turn about their hinges 61 until the shelf 62 and hence spacer boxes 100 are clear of the hole in the wall 20. With the dry lining box 10 in place with flange 31 resting against the wall 20, the installer may push the doors 60 into their closed position such that the tabs 70 rest against respective side of the central apertures 37 and the catch 71 springs into position to keep the door 60 closed. It is this closing action that causes automatic selection of whether or not the spacer boxes 100 should be retained. Figures 3 to 6 show the door 60 in various positions as it is being closed. The dry lining box 10 is being installed in a relatively thick wall 20, such as the 30mm wall 20 of Figure 8c. It can be seen that respective portions 23 of the wall 20 overlap each of the central apertures 73. As each door 60 is closed, the spacer boxes 100 are pushed against the overlapping portion 23 of wall 20. The small pips 104 offer only a small resistance such that, as shown in Figure 4, the spacer boxes 100 are pushed back through the holes 64 provided in the door 60 and fall into the interior of the dry lining box 10. The installer may then continue to push the door 60 closed until the catch 71 snaps into position, as shown in Figures 5 and 6. The spacer boxes 100 may then be removed by the installer. It will be appreciated that for thinner walls, the overlap of the wall 20 with the central apertures 73 will be reduced, if present at all, such that the spacer boxes 100 do not make contact with any overlap. As a result, the door 60 merely closes with the spacer boxes 100 still clipped in place and ready for being screwed into contact with the back 22 of the wall 20. With the doors 60 shut, the dry lining box 10 is then ready for the installation of the front plate wiring device, including its connection to electrical cables. This electrical connection is performed as follows. U-shaped knockouts 75 are provided in the sides 32-35 of the box's body 60 that extend inwardly from the back edge of each side 32-35. Two such knockouts 75 are provided in each of the sides 32 and 34 without a central aperture and one such knockout 75 is provided in each of the sides with a central aperture 33 and 35. Corresponding knockouts 76 are provided in the back 36, such that the knockouts 75 and 76 form back-to-back pairs as best seen in Figures 3 to 5. These knockouts 75 and 76 may be removed to provide access for electrical cables to connect to the front plate wiring device. Hence cables are merely pulled through suitably removed knockouts 75 and 76 and connected to the front plate wiring device in the usual fashion. With the front plate wiring device wired up, the front plate wiring device is attached to the dry lining box 10 to complete the installation. A pair of screws are placed through holes provided in the front plate wiring device (positioned according to industry standards). The nuts 90 also adopt the industry standard positions when the doors 60 are closed, such that the screws may be pushed through the bore 66 provided in the nut's housing 63 to engage with the thread of the nut 90. As the screws are tightened, the clamping means 50 are urged towards the wall 20 as the hinge post 67 slides along the hinge sleeve 38. Eventually either the tops 105 of the spacer boxes 100 or the shelves 62 contact the back 21 of the wall 22, and the screws are tightened a little more to ensure that the wall 20 is firmly clamped between the flange 31 and the spacer boxes 100/shelves 62. Accordingly, a dry lining box is provided that allows rapid installation in a variety of walls. Moreover, the installation requires little input from the installer. The design of the dry lining box also results in a requirement for the installer to carry fewer tools. In fact, a screwdriver may be all that is required. The screwdriver may be used to punch out knockouts, to lever the doors shut and to tighten the screws. As will be evident to the person skilled in the art, variations may be made to the embodiments described above without departing from the scope of the present invention defined by the appended claims.

Claims

CLAIMS:

1. A dry lining box for mounting in a wall, comprising a body and clamping means, the body comprising an open front face for receiving a front plate wiring device, and a side provided with an aperture for receiving the clamping means that are operable to secure the dry lining box to the wall, wherein the clamping means is provided with a first abutment surface that faces the front face of the dry lining box, the clamping means being rotatably mounted adjacent the aperture so as to rotate about an axis that extends substantially in the direction of the depth of the dry lining box from a first position where the first abutment surface resides within the body to a second position where the clamping means projects through the aperture such that at least part of the first abutment surface resides outside of the body.

2. The dry lining box of claim 1, wherein rotation of the clamping means is provided by a hinge that links the body to the clamping means.

3. The dry lining box of claim 2, wherein the hinge is arranged to allow the clamping means to move along the hinge axis relative to the body.

4. The dry lining box of claim 3, the clamping means further comprises a screw thread aligned to receive a screw entering from the front face.

5. The dry lining box of claim 4, wherein the screw thread is provided by a nut retained by the clamping means.

6. The dry lining box of any of claims 3 to 5, wherein the hinge comprises a post received within a sleeve, the post having an enlarged section that is received within an enlarged bore of the sleeve, the length of the enlarged bore being greater than the length of the enlarged section of the post.

7. The dry lining box of claim 6, wherein a groove is formed in the enlarged section to allow it to contract.

8. The dry lining box of claim 6 or claim 7, wherein the sleeve is provided by the body and the post is provided by the clamping means.

9. The dry lining box of any of claims 6 to 8, wherein the sleeve has a partially open section with an edge the open section providing a stop for limiting rotation of the clamping means.

10. The dry lining box of claim 9, wherein the stop sets the first position where the clamping means resides within the body.

11. The dry lining box of any preceding claim, wherein the clamping means further comprises a stop.

12. The dry lining box of claim 11, wherein the stop of the clamping means sets the second position where the first abutment surface is outside of the body.

13. The dry lining box of claim 12, wherein the stop comprises a tab arranged to overlap with a section of the body adjacent the aperture.

14. The dry lining box of any preceding claim, further comprising a fastener for securing the clamping means in the second position.

15. The dry lining box of claim 14, wherein the fastener is a catch that catches on a section of the wall adjacent the aperture.

16. The dry lining box of claim 15, wherein the catch is resilient to be able to deflect as the clamping means moves into the aperture and then to snap into position against the body.

17. The dry lining box of any preceding claim, wherein the first abutment surface is provided by a shelf that projects from the clamping means.

18. The dry lining box of claim 17, wherein the clamping means further comprises a spacer that provides a second abutment surface.

19. The dry lining box of claim 18, further comprising means for attaching the spacer to the remainder of the clamping means such that the second abutment surface faces the open front face of the dry lining box.

20. The dry lining box of claim 19, wherein the spacer is attached to the clamping means such that it is positioned on the first abutment surface.

21. The dry lining box of claim 20, wherein the clamping means comprises a hole sized and positioned to allow the spacer to fall from the first abutment surface into the interior of the body.

22. The dry lining box of claim 21, wherein the spacer comprises two blocks connected by a resilient link and a pair of holes sized to allow the spacer to fall from the first abutment surface into the interior of the body.

23. The dry lining box of claim 22, wherein the blocks comprise catches to secure the blocks in position on the first abutment surface.

24. The dry lining box of any preceding claim, wherein the body has a peripheral flange.

25. The dry lining box of any preceding claim, wherein the body comprises a hole or a knockout for passing cables into the interior of the body.

26. A method of partially installing the dry lining box of any of claims 21 to 25, comprising pushing the dry lining box into a hole provided in a wall such that a portion of the wall overlaps the aperture in the body's side, and pushing the clamping means to rotate the clamping means to the second position thereby causing the spacer to strike the overlapping portion of wall such that the spacer is pushed through the hole into the interior of the body.

27. The combination of any of the dry lining boxes of claims 1 to 25 and a front plate wiring device for attaching to the dry lining box.

28. The combination of claim 27 comprising the dry lining box of claim 6 or any of claims 7 to 25 when dependent upon claim 6, further comprising a screw threadingly engaged with the screw thread of the clamping means and tightened to bite on the front plate wiring device thereby causing the clamping means to clamp onto a wall.

29. A dry lining box substantially as described herein with reference to any of Figures 2 to 8 of the accompanying drawings.

30. The combination of a dry lining box and a front plate wiring device substantially as described herein with reference to any of Figures 2 to 8 of the accompanying drawings.

31. A method of installing a dry lining box substantially as described herein with reference to any of Figures 2 to 8 of the accompanying drawings. 231356; NPT; NPT