CA1111265A

CA1111265A - Mine roof supports

Info

Publication number: CA1111265A
Application number: CA340,106A
Authority: CA
Inventors: Malcolm Wake
Original assignee: Fletcher Sutcliffe Wild Ltd
Current assignee: Fletcher Sutcliffe Wild Ltd
Priority date: 1976-11-19
Filing date: 1979-11-19
Publication date: 1981-10-27
Also published as: AU5278179A; DE2948495A1; GB1557174A

Abstract

Abstract of the Disclosure A mine roof support comprises a plurality of chock legs, each being mounted at its lower end in a base means of the support, with co-operating and contacting convex/concave surfaces on the chock leg and base means respectively, and the chock leg being provided at a distance spaced upwardly from the contacting surfaces with an exterior abutment attached to a spacer tube extending from, and attached to, the end cap of the chock leg remote from the contacting convex/concave surfaces, the base means providing a co-operating abutment such that contact between the two abutments prevents withdrawal of the chock leg from the base means.

Description

s~J5 This invention relates to minc roof supports of the type ad~pted to extend along a mineral face at the goaf side of an armoured ~ace conveyor, and incor-porating a plurality of hydraulically extensible chock legs.
To accommodate relative movement between roof and floor, each chock leg has an articulated connection :
both at a base means of the support and at a roof beam of the support. In a known articulated connection a diametral hole is drilled in each end of the chock leg, to receive a retention pin for the pin in turn to be located in the base means or the roof beam to prevent withdrawal of the chock leg from the base means.
The object of the present invention is to provide a chock leg and base means cons-truction in which the use of pins is eliminated.
According to the present invention, there is provided a mine roof support comprising a plurality of chock legs, and base means, a lower end of each chock leg being mounted in said base means with cooperating and contacting convex/concave surfaces on said chock leg and said base means respectively, and end cap of said chock leg located remote from said contacting convex/concave surfaces, a -~
spacer tube extending from the end cap, abutment means ~:
': :
attached to said spacer tube, said abutment means including an exterior abutment attached to said spacer tube at a distance spaced upwardly from said convex/concave contacting surfaces, and a cooperating abutment connected to said base means, such that contact between said two abutments prevents withdrawal of said chock leg from said base means.

2~

With a chock leg restoration device as described in U.S. patent 4,030,308, the co-operating abutment of the base means may be constituted by the yoke common to a pair of spaced chock legs, which may partially surround the collar of each chock leg, the yoke and collar having co-operating arcuate surfaces. A stop surface may be carried by an abutment plate located at the free end of the preferably hydraulically and/or mechanically loaded restoration pin attached to the yoke, which abutment plate may be secured in position by a nut.

The invention will now be described in greater detail, by way of example, with reference to the accompany-ing drawings, in which:-Figure 1 is a front elevation of the base meansand lower ends of a pair of chock legs of a mine roof support in accordance with the invention; and Figure 2 is a side elevation of Figure 1.

In the drawings, the roof support 1 can be seen to comprise a fabricated base means 2 carrying a pair of forward and rearward hydraulically extensible chock legs in the case ~or example of a four leg support, each leg being indicated at 3, lower ends 4 of each leg terminating in a convex surface 5 to seat on a complementary concave surface 6 oE a member of the basc means 2, so that the chock leg may rock about its longitudinal axis in accord-ance with rela-tive roof/floor movements encoun-tered in service.

Be-tween the chock legs 3 is a restoration device described in greater detail in U.S. patent ~,030,308, the device comprising basically a hydraulically loaded pin 7 passing through a spherical bearing 8 in a yoke g .

2~

in enyagement at each end 10 to an adjacent chock leg 3, th~ pin 7 bclllg mountcd on a hydraulic ram (not shown).
For that purpose, each chock leg is provided with ~-_ 3 _ , ~3L~ 6~ - -8 collar ll ~ecured by the yoke end 10 and a semi circular yoke clamp 12, by bolte at centres 13 (Figure 2) with a oommo~ pt~ 14 having a shank 15 and a head 16 of larger cross-~ectlonal araa than the shank 157 the head 16 angag~ng a corre ponding hole in the collar ll. The pin 14 prevents leg rotation and hence avoids hydraulic ho e alignment problams. The ~ollar ll and yoke end 10 have complementary convex/concave surfaces 17, 18, re~pectively and the collar i~ supported from a spacer tube 19, attached to a chock leg end cap 20. Spaced from the yoke 9 i~ an abutment plate 21 havin~ a stop slur~ace 22 a~d ~ecured on the pin 7 by a nut 23. , Thu , the chock legs 3 are retalned with re~pect to the ba9e means 2 by the interen~agement of arcuate surfaces 17, 18, a~d whe~ it i~
des~red to releasa the lo~er ends of the chock legs 3 e.g. to enabla the legs to be removed from tha ~upport l, tha bolts on centres 13 are removed, whereupon the collar 11 may be removed from the yoke end lO by disassembling *he yoke clamp 12.
Should ~or any ~eason the chock legs 3 be lifted from ~eating on surfaces 6 of the ba~a mean~ 2, , .

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only partial lif t~ng can taXe place until the yoke 9 contact~ the Cltop 3urface 22, the bearin~ 8 Ylidi~ up the pin 7.

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Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A mine roof support comprising a plurality of chock legs, and a base means, a lower end of each chock leg being mounted in said base means with co-operating and contacting convex/concave surfaces on said chock leg and said base means respectively, an end cap of said chock leg located remote from said contacting convex/concave surfaces, a spacer tube extending from the end cap, abutment means attached to said spacer tube, said abutment means including an exterior abutment attached to said spacer tube at a distance spaced upwardly from said convex/concave contacting surfaces, and a co-operating abutment connected to said base means, such that contact between said two abutments prevents withdrawal of said chock leg from said base means.

2. A mine roof support as claimed in claim 1, wherein said abutment means includes a collar and said co-operating abutment includes a yoke between a pair of spaced chock legs said yoke forming part of a chock leg restoration device, said yoke partially surrounding said collar of each of said chock legs, said yoke and said collar having co-operating arcuate surfaces.

3. A mine roof support as claimed in claim 2, wherein said restoration device further comprises a hydraulically and/or mechanically loaded restoration pin and an abutment plate located at a free end thereof.