GB2508225A

GB2508225A - An electrically conductive earthing connector block

Info

Publication number: GB2508225A
Application number: GB201221242A
Authority: GB
Inventors: Graham Taylor
Original assignee: BAXXTERS Ltd
Current assignee: BAXXTERS Ltd
Priority date: 2012-11-26
Filing date: 2012-11-26
Publication date: 2014-05-28
Anticipated expiration: 2032-11-26
Also published as: GB2518553B; GB2518554B; GB2508225B; GB201221242D0; GB2518554A; GB2518553A

Abstract

An electrically conductive earthing block 10 has stepped edge faces (16) with preferably at least one bore 28 in each face. It may also have the same number of bores in an opposed straight edge face (22). Screws 30 hold elongate conductors in these bores. It may be mounted on a top-hat mounting plate 62 using insulating pillars 122, or on a flat insulating plate (130, Fig 14), and may have attachment means for a safety label 72. A T-shaped extension block 64 may also be attached. The block may be mounted near to a link block 80, to which it may be electrically connected either by a pivoting link bar (90, Fig 8) attached to holes 38, 82, or by a link pin (100, Fig 10) going through hole 86 into bore 28.

Description

[0001] An electrically conductive earthing connector block [0002] The present invention relates to an electrically conductive earthing connector block, for example, using the terminology of the electrical regulations for the United Kingdom for an example within a group of products to which the present invention relates, a Main Earthing Terminal block (MET) . It also relates to an assembly which includes such a block.

[0003] One previously proposed construction of electrically conductive earthing connector block comprises a block of electrically conductive material having a series of bores provided in an intended upper face, and a series of bores provided in an intended lower face in registration with those provided in its upper face. Each of the bores is designed to receive an end of an earthing conductor, for example a cable or a wire. One or more screws which are in screwthreaded connection with a screwthreaded hole or respective screwthreaded holes extending transversely of the bores are used to clamp the earthing conductors or other protective conductors in electrical connection with the earthing connector block.

[0004] A disadvantage of such a construction is ifs limited versatility.

[0005] The present invention seeks to provide a remedy to this disadvantage.

[0006] Accordingly, a first aspect of the present invention is directed to an electrically conductive earthing block having two main faces on respective opposite sides of the block, and having, as viewed in a direction generally a right angles to one of the main faces, towards that face, a stepped edge, the thickness of the block providing edge faces along that stepped edge, extending between the said main faces, the block having a plurality of bores extending into the block from the edge faces at the stepped edge, there being at least one bore of the said plurality of bores at each step of the stepped edge, the bores of the said plurality of bores being adapted to receive respective ends of respective elongate electrical earthing conductors to effect, when the block is in use, electrical connections between those earthing conductors and the earthing block.

I

[0007] The stepped edge provides some similarities as regards connectability with the previously proposed construction of earthing block, but at the same time provides a larger main face which can be used for example to mount onto the block a plate bearing letters and/or numbers, such as a warning plate or an instruction plate or an identification plate, or to mount an extension block on to the earthing block, or to mount the block on one or more insulators.

Alternatively or in addition, the stepped construction affords the advantage that a link bar can be connected to the earthing block, and swung away from a step edge without at any time extending beyond the overall width of the block, so as to facilitate a ready disconnection without requiring a space wider than the width of block.

[0008] The block may also have, as viewed in the said direction, a generally straight edge on the opposite side of the block to that of the stepped edge, the thickness of the block providing an edge face along the said generally straight edge, extending between the said main faces, the block having a further plurality of bores extending into the block from the edge face at the said generally straight edge, in the opposite direction relative to that in which the plurality of bores referred to in statement of invention number one extend into the block, the bores of this further plurality of bores also being adapted to receive respective ends of respective elongate electrical earthing conductors to effect, when the block is in use, electrical connections between those earthing conductors and the earthing block.

[0009] This provides the advantage of an increased number of possible connections to the earthing block. The conductors connected in the holes along the straight edge may be in alignment with the conductors connected in the holes along the stepped edge. To maximise the number of the holes available in this way, the same number of such holes may be provided along the straight edge as are provided along the stepped edge, and may be in registration therewith.

[0010] At least one electrically insulating pillar may be mounted on one of the said main faces of the block.

[0011] This provides a convenient manner of electrically insulating the block from its surroundings.

[0012] A location for a label or indicator plate, for example a safety warning label, may be provided on one of the said main faces of the block.

[0013] This makes efficient use of space on that main face of the block provided by virtue of the stepped construction.

[0014] The earthing block may be provided with an electrically conductive extension block electrically connected to one of the main faces of the earthing block.

[0015] This makes an alternative efficient use of space on one of the main faces of the earthing block provided by virtue of the stepped construction, to enable an increase in the number of connections that can be made to that block.

[0016] According to a second aspect of the present invention, there is provided an assembly comprising an electrically conductive earthing block having two main faces on respective opposite sides of the block, and having, as viewed in a direction generally at right angles to one of the main faces, towards that face, a stepped edge, the assembly further comprising an electrically conductive link block spaced apart from the said electrically conductive earthing block but electrically connected thereto by a link bar pivoted to the link block and releasably connected, when in use, to the earthing block on a step of the stepped edge inwardly of the ends of the stepped edge, so that the earthing block and the link block can be electrically disconnected from one another by swinging the bar about the pivot away from an edge of the step.

[0017] The stepped construction enables the link bar to be connected to the earthing block, and swung away from a step edge without extending beyond the overall width of the block, so as to facilitate a ready disconnection without reguiring a space wider than the width of block.

[0018] According to a third aspect of the present invention, there is provided an assembly comprising an electrically conductive earthing block having two main faces on respective opposite sides of the block, and having, as viewed in a direction generally at right angles to one of the main faces, towards that face, a stepped edge, the assembly further comprising an electrically conductive link block spaced apart from the said electrically conductive earthing block but electrically connected thereto, when the blocks are in use, by a generally linear link pin extending through respective holes in the electrically conductive link block and the electrically conductive earthing block.

[0019] Such a construction enables a link pin co effect connection and disconnection between the earthing block and the link block without the need for any pivoting action.

[0020] The hole in the electrically conductive link block may be a through-hole, whereby the link pin may be withdrawn from the earthing block through the hole in the link block.

[0021] According to a fourth aspect of the present invention, there in provided an assembly comprising an electrically conductive earthing block having two main faces on respective opposite sides of the block, and having, as viewed in a direction generally at right angles to one of the main faces, towards that face, a stepped edge, the assembly further comprising an electrically conductive link block spaced apart from the said electrically conductive earthing block but electrically connectable thereto by a link bar pivotable about the link block and connectable to the earthing block on a step of the stepped edge inwardly of the ends of the stepped edge, and also electrically connectable by a generally linear link pin extending through respective holes in the electrically conductive link block and the electrically conductive earthing block, whereby electrical connection between the earthing block and the link block can be effected selectively either by such a link bar or by such a link pin.

[0022] This affords the advantage that the earthing block and the link block can be electrically connected to one another, or electrically isolated from one another, selectively by a bar or a pin.

[0023] Example embodiments of these aspects of the present invention will now be described in greater detail with reference to the accompanying drawings, in which: [0024] Figure 1 shows a side view of an electrically conductive earthing block embodying the present invention; [0025] Figure 2 shows a view from one end of the block shown in Figure 1; [0026] Figure 3 shows the view from the other end of the block shown in Figure 1; [0027] Figure 4 shows a perspective view of the block shown in Figures 1 to 3 from one side and from one end thereof; [0028] Figure 5 shows a perspective view of the block shown in Figures 1 to 3 from one side and from the other end thereof; [0029] Figure 6 shows a perspective view from one side and from one end of an assembly which incorporates the block shown in Figures 1 to 5; [0030] Figure 7 shows a part of the assembly shown in Figure 6 from one side, together with a link bar; [0031] Figure 8 shows a side view of the part shown in Figure 7 together with another part of the assembly shown in Figure 6, with some features not shown, for clarity; [0032] Figure 9a shows a side view of a connecting link pin to be used in conjunction with the assembly shown in Figure 6; [0033] Figure 9b shows a side view of the connecting link pin shown in Figure Sa connected to one part of the assembly shown in Figure 6; [0034] Figure 10 shows a side view of the pin shown in Figure 9a connected to two parts of the assembly shown in Figure 6, with some features not shown, for clarity; [0035] Figure 11 shows an underneath view of the assembly shown in Figure 6; [0036] Figure 12 shows an end view of parts of the assembly shown in Figure 11; [0037] Figure 13 shows a perspective view of the parts shown in Figures 11 and 12 from one side and from one end; and [0038] Figure 14 shows a front view of an insuiafing plate which may be used instead of the parts shown in Figures 11 to 13.

[0039] An earthing block 10 shown in Figure 1 is made of an electrically conductive material, for example a copper alloy, for example bronze or brass. It has two main faces 12, only one of which is visible in Figure 1. The view shown in Figure 1 is in a direction towards and generally at right angles to this main face 12.

[0040] As can be seen from Figure 1, the block 10 has a straight edge 14, and, opposite this straight edge 14, a stepped edge 16, providing a series of steps 18 progressing from both sides of the block 10 as shown in Figure 1 at respective positions relatively close to the straight edge 14 to an end 20 of the block 10 opposite to the end of the block 10 at the straight edge 14.

[0041] As can be seen from Figures 2 and 3, the thickness of the block 10 between its main faces 12 provides an upper face 22 along the straight edge 14, and a series of lower faces 24 of the respective steps 18 respectively of the stepped edge 16.

[0042] A series of bores 26 extend inwardly from the upper face 22 in a downward direction towards the opposite end 20 of the block 10. Respective bores 28 extend inwardly into the block 10 respectively from each of the steps 18, in a direction towards the upper face 14. Associated with each of the bores 26 and 28 are a pair of screwthreaded holes extending from the said one of the main faces 12 towards its associated bore 26 or 28 transversely thereof, with respective screws 30 (only the heads of which are visible in Figure 1) extending through these screwthreaded holes towards the associated bore 26 or 28.

[0043] The two bores 26 at one end of the upper face 22, as well as the two bores 26 at the other end of the upper face 22, are of greater diameter than the other bores 26 in the upper face 22.

Likewise, the screws 30 for these bores of greater diameter are themselves of greater diameter. The bores 28 are of the same diameter as that of the larger bores 26, and their associaned screws are of the same diameter as that of the screws of the larger bores 28, except that the bore 28 at the end 20 and the bores 28 of the next most adjacent steps 18, along with their associated screws 30, are larger still.

[0044] A through-hole 32 extends through the block 10 from one main face 12 to the other, the through-hole 32 being substantially central relative to the main faces 12. Bores 34 are provided on both sides of the through-hole 32, extending into the block 10 from the said one of the main faces 12. Ihese provide recesses for corresponding locators on an extension block not shown in Figure 1.

[0045] Internally screwthreaded through-holes 36 are provided which extend all the way through the block 10 from one mann face 12 to the other. These facilitate the mounting of the block 10.

[0046] A further through-hole 38 extends through the block 10 at the end step 18, adjacent to the end 20 of the block 10. A rectangular recess 40 also extends from this end 20 inwardly towards the end 14 underneath the through hole 38, to accommodate the head of an electrically conductive bolt which may pass through the hole 38 when the block 10 is in use.

[0047] Internally screwthreaded bores 42 are provided respectively on opposite sides of the through-hole 36 to facilitate the attachment of an indicator plate not shown in Figure 1.

[0048] When the block 10 is in use, respective ends of electrical earthing conductors (not shown) are inserted into the bores 26 and 28, and are clamped in electrical connection with the earthing block 10 by means of the screws 30.

[0049] An electrical earthing assembly 60 shown in Figure 6 comprises an earthing block 10 as shown in Figures 1 to 5 mounted on a top-hat sectioned mounting plate 62 having mounting holes 63 along its sides. The manner in which it is so mounted will be described subsequently herein. The assembly 60 further comprises an electrically earthing extension block 64 which is generally T-shaped and which is electrically connected to the block 10 by way of a bolt 66 which passes through a hole (not shown) in the extension block 64 and the hole 32 in the mounting block 10. Locating spigots (not shown) on the underside of the extension block 64 are received in the bores 34 of the main block 10 to inhibit rotation of the extension block 64 about the bolt 66, so that the extension block 64 is rigidly connected to the block 10. The extenoion block 64 is provided with a series of through-holes 68 which pass through the upper part of the 7-shape, in the same direction as the bores 26 and 28, and fixing screws 70 are provided for each through-hole 68 in the same manner as the screws 30 are provided for the bores 26 and 28.

[0050] An indicator plate 72 has been attached to the said one of the main faces 12 of the block 10 by way of screws 74 which pass through the plate 72 into the screwthreaded bores 42 of the block 10.

[0051] The assembly 60 further comprises an electrically conductive link block 80 comprising a bar of the same electrically conductive material as the block 10, oriented generally parallel to the end faces 20 and 22, and located adjacent to but spaced apart from the end 20 of the block 10. The length of the bar is substantially the same as the width of the block 10 adjacent to the end 20 and one step upwardly therefrom.

[0052] The link block 80 is provided with a through-hole 82 and a recess 84 corresponding in shape, size and orientation with the hole 38 and recess 40 in the block 10, and positioned in registration therewith. Likewise, the link block 80 is provided with a through-hole 86 and screws 88 corresponding to the bore 28 and associated screws 30 at the end 20 of the block 10, and in registration there with, and screwthreaded through-holes 89 corresponding to the holes 36 in the main eartbing block 10.

[0053] One way in which the link block 80 may be electrically connected to the earthing block 10 is shown in Figures 7 and 8. Thus a bar or plate 90 in which a through-hole (not shown) is provided at one end of the plate 90 through which a bolt 92 extends, is also provided with a slot 94 at its other end. The bolt 92 also extends through the hole 82 in the link bar 80 and is secured thereto by this bolt 92. The plate 90 is pivotable about the bolt 92 when the latter is slackened. The other end of the plate 90 is secured to the block 10 by way of a bolt 96 which passes through the siot 94 of the bar 90 and aiso through the through-hole 38 in the main biock 10.

[0054] To disconnect the electrical connection between the link biock 80 and the main block 10, the boits 92 and 96 are slackened, and the plate 90 is pivoted about the bolt 92 so that the end of the plate 90 in which the slot 94 is provided swings away from the end step of the block 10, so that the bolt 96 is no longer in the slot 94, without the plate 90 needing to extend beyond the full width of the block 10, defined by the end face 14 thereof, before a complete electrical isolation of the link block 80 from the main earthing block 10 is effected.

[0055] An alternative manner in which the link block 80 can be electrically connected to and electrically isolated from the main earthing block 10 is shown in Figures 9 and 10. Thus Figure 9 shows a link pin 100 which is generally circular in cross-section and which has an enlarged rectangular cross-section at one end 102 thereof.

With the pin 100 inserted through the through-hole 86 and the bore 28 at the end 20 of the main earthing block 10, and the associated screws 88 and 30 duly tightened, a full electrical connection is effected between the main earthing block 10 and the link block 80.

The screws may be slackened so that the pin 100 falls away from the main block 10 to effect an electrical isolation between the link block 80 and the main block 10.

[0056] An end of a main earthing conductor (not shown) of the means of earthing may be electrically connected to the link block 80.

Such a connection may be effected either by insertion of that end into the hole 86 and then secured by means of the screws 88, or if that end is constituted by a crimped copper tube terminal for example, it may be secured to the link block 80 by means of the bolt 92.

[0057] It will be appreciated that either selected one of the pin 100 and the plate 90 can be used to effect electrical connection and electrical isolation between the link block 80 and the main earthing block 10.

[0058] Figures 11 to 13 show the manner in which the main block and the link block 80 are mounted on the mounting plate 62. Thus the main block 10 is securely fixed to but spaced from the mounting plate 62 byway of insulating pillar bolts 120 extending through respective holes in the mounting plate 62 and into the screwthreaded holes 36 in the main block 10, with electrically insulated or insulating pillars 122 comprising solid cylinders from which screwthreaded bolt portions 124 extend, the pillars 122 being sandwiched between the main earthing block 10 and the mounning plate 62. Corresponding bolts 120 are provided for the link block 80.

[0059] As an alternative to the mounting plate 62, there may be provided a generally flat insulating plate 130 as shown in Figure 14.

[0060] The earthing block 10 and the assembly 60 provide means for testing, insulating, and earthing conductor identification in an earthing system. The diameter of the smaller of the bores 26 may be in the range for example from 2mm to 8mm, and that of the larger bores 26 and the bores 28 may be in the range from 3mm to 15mm, but it will be appreciated that these bores could be any size suitable for any application for which the block 10 and assembly 60 are used.

[0061] Numerous variations and modifications to the illustrated embodiment of the present invention may be made without taking the resulting construction outside the scope of the present invention.

For example they may be more or fewer steps in the earthing block 10.

Equally there may be more or fewer bores 26 and 26 formed in the earthing block 10.

Claims

Claims: 1. An electrically conductive earthing block having two main faces on respective opposite sides of the block, and having, as viewed in a direction generally at right angles to one of the main faces, towards that face, a stepped edge, the thickness of the block providing edge faces along that stepped edge, extending between the said main faces, the block having a plurality of bores extending into the block from the edge faces at the stepped edge, there being at least one bore of the said plurality of bores at each step of the stepped edge, the bores of the said plurality of bores being adapted to receive respective ends of respective elongate electrical earthing conductors to effect, when the block is in use, electrical connections between those earthing conductors and the earthing block.
2. An electrically conductive earthing block according to claim 1, in which the block also has, as viewed in the said direction, a generally straight edge on the opposite side of the block to that of the stepped edge, the thickness of the block providing an edge face along the said generally straight edge, extending between the said fl main faces, the block having a further plurality of bores extending * .*.*.* iito the block from the edge face at the said generally straight edge, in the opposite direction relative to that in which the * plurality of bores referred to in claim 1 extend into the block, the S..* bores of this further plurality of bores also being adapted to receive respective ends of respective elongate electrical earthing ***: conductors to effect, when the block is in use, electrical * connections between those earthing conductors and the earthing block.
3. An electrically conductive earthing block according to claim 2, in which the bores extending into the block from the edge face at the said generally straight edge are in alignment respectively with the bores referred to in claim 1.
4. An electrically conductive earthing block according to claim 3, in which the same number of such bores are provided along the straight edge as are provided along the stepped edge, and are respectively in registration therewith.
5. An electrically conductive earthing block according to any preceding claim, in which at least ne electrically insulating pillar is mounted on one of the said main faces of the block.
6. An electrically conductive earthing block according to any preceding claim, in which a location for a label or indicator plate, for example a safety warning label, is provided on one of the said main faces of the block.
7. An electrically conductive earthing block according to any preceding claim, in which the earthing block is provided with an electrically conductive extension block electrically connected to one of the main faces of the earthing block.
8. An assembly comprising an electrically conductive earthing block having two main faces on respective opposite sides of the block, and having, as viewed in a direction generally at right angles to one of the main faces, towards that face, a stepped edge, the assembly further comprising an electrically conductive link block spaced apart from the said electrically conductive earthing block but electrically connected thereto by a link bar pivoted to the link * block and releasably connected, when in use, to the earthing block on ". : a step of the stepped edge inwardly of the ends of the stepped edge, * " so that the earthing block and the link block can be electrically disconnected from one another by swinging the bar about the pivot *r away from an edge of the step.
9. An assembly comprising an electrically conductive earthing block having two main faces on respective opposite sides of the block, and having, as viewed in a direction generally at right angles to one of the main faces, towards that face, a stepped edge, the assembly further comprising an electrically conductive link block spaced apart from the said electrically conductive earthing block but electrically connected thereto, when the blocks are in use, by a generally linear link pin extending through respective holes in the electrically conductive link blocc and the electrically conductive earthing block.
10. An assembly according to claim 9, in which the hole in the electrically conductive link block is a through-hole, whereby the link pin may be withdrawn from the earthing block through the hole in t:-e link block.
11. An assembly comprising an electrically conductive earthing block having two main faces on respective opposite sides of the block, and having, as viewed in a direction generally at right angles tD one of the main faces, towards that face, a stepped edge, the assembly further comprising an electrically conductive link block spaced apart from the said electrically conductive earthing block but electrically connectable thereto by a link bar pivotable about the link block and connectable to the earthing block on a step of the stepped edge inwardly of the ends of the stepped edge, and also electrically connectable by a generally linear link pin extending through respective holes in the electrically conductive link block and the electrically conductive earthing block, whereby electrical connection between the earthing block and the link block can be effected selectively either by such a link bar or by such a link pin.
12. An electrically conductive earthing block substantially as *: hereinbefore described with reference to and as illustrated in Figures 1 to 5 of the accompanying drawings.
13. An assembly substantially as hereinbefore described with reference to and as illustrated in Figures 6, 11, 12 and 13, with or * without the parts shown in Figures 7 and 8, and with or without the cart shown in Figures 9a, 9b and 10, and with or without the modification shown in Figure 14 of the accompanying drawings. *.se* * *