BRACKET FOR SUSPENDING A CHAIN

Abstract: A bracket (3) for suspending a chain (19) or the like member is disclosed. The bracket (3) comprises a body portion (7, 9, 11) and a pair of slots (15) formed in the body portion for receiving links (17) of the chain (19) that are separated by one or more intermediate links (17a).

Description: BRACKETFORSUSPENDINGACHAIN The present invention relates to a bracket for suspending a chain, cable or the like elongate member which has a cross-sectional profile that varies along the length of the member. The present invention relates particularly to a bracket for suspending a chain. A particular application of the bracket is in underground mining or tunnelling where services for a mine, such as, but not limited to, ventilation ducts, electrical cables, water pipes, air pipes, and gas extraction ducts, are usually supported from the roof of the mine in order to minimise the possibility of damage to the services. A known method of supporting services in underground mines is by means of chains which are suspended from exposed ends of rock bolts, -straps, mesh, bearing plates, or other members that are secured to the mine roof for other purposes. In underground mines, it is also known to support services (particularly heavier services) directly with purpose-built brackets that are secured to the mine roof as part of the installation procedure for the services. An object of the present invention is to provide a support arrangement for services, and more particularly a bracket for use as part of the support arrangement, which is an improvement over known support arrangements. According to the present invention there is provided a bracket for suspending a chain or the like member, the bracket comprising a body portion and a pair of slots formed in the body portion for receiving links of the chain that are separated by one or more intermediate links. It can readily be appreciated that with such an arrangement the chain can be securely locked to the bracket when two links that are separated by one or more intermediate links are positioned in the slots. It can also readily be appreciated that such an arrangement does not require the use of pins or other means in conjunction with the bracket to achieve secure locking of the chain to the bracket as is required by way of example with a number of the embodiments of Australian complete application 28615/92 in the name of Kwadcorp Pty. Ltd. It is preferred that the body portion and the slots be formed so that, when one link is in each slot, and a force is applied to an end of the chain, the intermediate link or links that separate the links in the slots contacts the body portion and thereby prevents the links in the slots sliding from the slots to release the chain from the bracket in response to the applied force. A preferred application of the bracket is in -underground mining to support a chain from the roof of an underground mine as part of a support arrangement for services, such as water pipes or conveyors for the mine. In this application, pairs of the brackets are supported from the roof of the mine at spaced intervals along the required path for the services and a chain is suspended from the brackets of each pair and the services are cradled by the chains. In the underground mining application, it is preferred that (a) the bracket comprise a hook and that (b) W-straps, bearing plates, or other members which are secured to the underground mine roof in the normal course of events comprise an opening for receiving the hook so that the brackets used to suspend the chains can be supported from the roof of the mine by the W-straps, bearing plates or other existing members. It is preferred that the body portion comprises a central member which separates the slots. It is preferred particularly that the body portion comprises two parallel outer members, one on each side of the central member, with the spaces between each outer member and the central member defining the slots. It is preferred particularly that the central member be longer than the outer members and define the hook of the bracket. According to the present invention there is also provided a chain hanger for use in supporting services in an underground mine comprising, in combination, a plurality of the brackets of the present invention as described in the preceding paragraphs, and W-straps, bearing plates, or other members adapted to be secured to a roof of an underground mine and each having one or more openings for receiving the hooks of the brackets. According to the present invention there is also provided a support arrangement for services in an underground mine comprising, in combination, a plurality of the chain hangers described in the preceding paragraph, and a plurality of chains for use with the chain hangers to cradle services. The present invention is described further by way of example with reference to the accompanying drawings, in which: Figure 1 is a series of front, side, and perspective views of one preferred embodiment of a bracket in accordance with the present invention; Figure 2 is a series of front, side, and perspective views of another preferred embodiment of a bracket in accordance with the present invention; Figure 3 is a series of front, side, and perspective views of another preferred embodiment of a bracket in accordance with the present invention; Figure 4 is a part-sectional, part-side view of a rock bolt assembly secured to the roof of an underground mine with a bearing plate positioned between the nut of the rock bolt assembly and the roof of the mine and two brackets of the type shown in Figure 1 coupled to the bearing plate with each bracket suspending a chain; and Figure 5 is a view of the lefthand side (shown in Figure 4 in the direction of the arrow A in Figure 4) with the bearing plate removed in order to simplify the figure. The preferred embodiments of the bracket 3 shown in Figures 1, 2, and 3 have the same general configuration and the same reference numerals are used in the Figures to denote the same structural features. The brackets 3 are particularly suited for use in underground mining to support chains from the roof of an underground mine as part of a support arrangement for services, such as water pipes or conveyors, for the mine. In this application; i. pairs of the brackets 3 are supported from the roof of the mine at spaced intervals along the required path for the services, by coupling the brackets 3 to W- straps, bearing plates, or other members that are secured to the mine roof in the normal course of a mining operation, and ii. a chain is suspended from the brackets 3 of each pair and the services are cradled by the chains. With reference to Figures 1, 2, and 3, each bracket 3 is formed advantageously from a plate and comprises a central prong 7 and two outer prongs 9 which extend in a parallel arrangement from an interconnecting web 11. The central prong 7 of each bracket 3 is longer than the outer prongs 9 and is folded over at its free end to form a hook 13 to couple the bracket 3 to a W-strap, bearing plate, or other support member. By way of example, with reference to Figure 4, the hooks 13 of two brackets 3 of the type shown in Figure 1 are shown received in openings 21 in a bearing plate 23 that is secured to a mine roof 61 by means of a rock bolt assembly 63 so that the brackets 3 are supported from the roof 61. The bearing plate 23 is of a type described in International application PCT/AU94/00419 (WO95/03477) of the applicant, and the disclosure in the International application is incorporated herein by reference. It can readily be appreciated that the hooks 13 of the brackets 3 could be received in openings formed in any suitable members that are secured to a mine roof. With reference to 2, for high loading conditions the hook 13 may include a locking pin 71. With further reference to Figures 1, 2, and 3, each bracket 3 comprises a pair of slots 15 which are formed by the gaps between the central prong 7 and each outer prong 9. As can be seen in Figure 5, in relation to the bracket 3 of the type shown in Figure 1, the dimensions of the slots 15 are selected to receive, in use, the links 17 of a chain 19. Furthermore, with reference to Figures 4 and 5, the width W of the central prong 7 of the brackets 3 of the type shown in Figure 1 (and also of the brackets 3 shown in Figures 2 and 3) is selected so that, in use, the links 17 that are received in the slots 15 are separated by a single link 17a (or a multiple of the links) . With this arrangement, as can be seen from Figure 4, it can readily be appreciated that the chain 19 can be suspended from the bracket 3 by wrapping an end section of the chain 19 around the central prong 7 of the bracket 3 and inserting the links 17 in the slots 15 with the interconnecting link 17a (or links) extending across the central prong 7. It can also readily be appreciated that, with this arrangement, when a force is applied to one end of the chain 19 in the direction of the arrow marked F in Figures 4 and 5, the bracket 3 prevents the interconnecting link 17a (or links) sliding into and through the slot 15 on the lefthand side of Figure 5 in response to the force F. Specifically, the force F causes the interlocking link 17a (or links) to contact the outer prong 9 on the lefthand side of Figure 5 and this contact prevents the interconnecting link 17a (or links) sliding into and through the slot 15. As a consequence, the combination of the structure of the bracket 3 and the structure of the chain 19 enables the chain 19 to be securely locked to the bracket 3. It is noted that in order to securely lock the chain 19 to the bracket 3 it is not essential that there be a close fit of the links 17 in the slots 15. This is a considerable advantage in underground mining where the working environment is difficult. It is also noted that the configuration of the bracket 3 avoids the necessity to feed the chain 19 through the relatively small keyhole opening which characterises the arrangement of Kwadcorp complete application 28615/92. With the bracket 3, all that is required is to loop the chain 19 around the central prong 7 and to adjust the position of the chain 19 relative to the bracket 3 until the links are received in the slots 15. Many modifications may be made to the preferred embodiments of the bracket 3 without departing from the spirit and scope of the present invention. For example, whilst each preferred embodiment of the bracket 3 comprises a pair of slots 15 and therefore is designed to suspend a single chain 19, it can readily be appreciated that the present invention is not restricted to such an arrangement and extends to brackets which can support a plurality of chains 19. By way of particular example, a suitable form of such a bracket may comprise a plurality of pairs of slots. Furthermore, whilst each preferred embodiment of the bracket 3 is a separate member which is formed with a hook 13 that is adapted to co-operate with openings 21 in bearing plates 23 or other members, such as W-straps, that are secured to a mine roof, it can readily be appreciated that the present invention is not restricted to such an arrangement and extends to arrangements in which the bracket is formed integrally with the bearing plates or other such members. Furthermore, whilst the preferred embodiments of the bracket 3 are described as being suitable to suspend chains 19, it can readily be appreciated that the present invention is not restricted to this application and the bracket of the present invention may be used to suspend any elongate member that has a cross-sectional profile that varies along the length of the member.

Claims: THE CLAIMS DEFINED IN THE INVENTION ARE AS FOLLOWS: 1. A bracket for suspending a chain or the like member, the bracket comprising a body portion and a pair of slots formed in the body portion for receiving links of the chain that are separated by one or more intermediate links. 2. The bracket defined in claim 1 wherein the body portion and the slots are formed so that, when one link is in each slot, and a force is applied to an end of the chain, the intermediate link or links that separate the links in the slots contacts the body portion and thereby prevents the links in the slots sliding from the slots to release the chain from the bracket in response to the applied force. 3. The bracket defined in claim 2 wherein the body portion comprises a central member which separates the slots. 4. The bracket defined in claim 3 wherein the body portion comprises two parallel outer members, one on each side of the central member, with the spaces between each outer member and the central member defining the slots. 5. The bracket defined in claim 4, wherein the central member is longer than the outer members. 6. The bracket defined in any one of the preceding claims further comprises a hook for coupling the bracket to a support member. 7. The bracket defined in claim 6, when dependent on claim 4, wherein the central member defines the hook. 8. A chain hanger for use in supporting services in an underground mine comprising, in combination, a plurality of the brackets defined in any one of the preceding claims, and W-straps, bearing plates, or other support members adapted to be secured to a roof of an underground mine and each having one or more openings for receiving the hooks of the brackets. 9. A support arrangement for services in an underground mine comprising, in combination, a plurality of the chain hangers defined in claim 8, and a plurality of chains for use with the chain hangers to cradle services.

Inventors: GRAY PETER ANDREW, GRAY, PETER, ANDREW
Applicants: BHP ENG PTY LTD, GRAY PETER ANDREW, BHP ENGINEERING PTY. LTD., GRAY, PETER, ANDREW
Application year: 1995
Main classification: F16B45
IPC codes: E21F17, F16G15, F16L3