GB2030638A

GB2030638A - A Quick-release Joint Between a Prop and a Sill Piece

Info

Publication number: GB2030638A
Application number: GB7932009A
Authority: GB
Original assignee: GORNICZOHUTNICZY MIEDZI ZAKLAD
Current assignee: GORNICZOHUTNICZY MIEDZI ZAKLAD
Priority date: 1978-09-15
Filing date: 1979-09-14
Publication date: 1980-04-10
Also published as: GB2030638B; DE2937326C2; PL117063B1; FR2445434A1; DE2937326A1; PL209638A1

Abstract

A joint for interconnecting a prop 4 and sill piece 2 in a mining roof- support unit, comprises a ball 1 fixed to the sill piece and engaging in a part-spherical socket of a socket member 3 fixed to the lower end of the prop, at least two holders 5 for holding the ball in the socket, having lower parts 9 which together encircle the ball 1 below its horizontal plane of symmetry, and upper parts 8 held between the socket member 3 and a locking ring 6 mounted slidably on the socket member, such that in a locked position of the joint the locking ring 6 prevents the release of the holders from the socket member but permits release of the holders and thus of the joint when it is shifted in an upward direction. <IMAGE>

Description

SPECIFICATION A Quick-release Joint Between a Prop and a Sill Piece This invention relates to a joint for interconnecting a prop to a sill piece in a mining roof-support unit.

Known joints between props and sill pieces include a universal joint or ball coupling, and coupling elements such as screws, threaded elements or pins. Under the operating conditions prevailing in mines, these coupling elements are intensively corroded, since they are in contact with softened rock floors of the mines and corrosive mine water. As a result, frequent damage occurs. The greatest disadvantage of these known joints is that they are very difficult to disassemble and it often happens that it is impossible for disassembly to be achieved.

Because of this, it is necessary to strap not only the joint itself, but also the elements co-operating with it from the side of the prop and the sill piece.

One known joint disclosed in Polish Patent Specification No. 79,328 comprises a ball mounted in a semi-circular socket of a socket member and locked in the socket with a split ring cotter to prevent the ball from slipping out of the socket. The split ring cotter is fixed permanently to the socket member by screws.

A similar joint is disclosed in Polish Patent Specification No. 83,379, and comprises a ball coupling for joining a prop to the roof-support bar.

The convex part of the ball coupling is carried by the prop whereas the concave part of the coupling is carried by the roof-support bar. The whole coupling is prevented from releasing by a ring-like plate having an aperture in the form of a spherical sector wherein the convex part of the coupling is fitted. The convex part of the coupling in the region of the plate consists of at least two halfring parts whose outer profiles are that of a ball surface. The aforesaid elements of the joints are connected together by screws.

In G.F.R Patent Specification No. 1,199,723 there is disclosed a joint consisting of a spherical recess in a prop and supported on a spherical projection of a roof support bar. The spherical projection is connected with the spherical recess by means of a transverse pin pushed through the projection and the recess and into the prop.

The main object of the present invention is to avoid or substantially reduce the aforementioned disadvantages of the known joints which include elements which are damaged under the operating conditions prevailing in mines and which are of complicated design hindering repair.

In accordance with the invention a quickrelease joint between a prop and a sill piece in a mining roof-support unit, having a ball fixed to the sill piece and a socket member having a concave spherical socket and constituting the lower end of a prop, is characterized in that at least two segmental holders are mounted separably in the socket member and preferably have a crosssection which is similar to a channel whose upper wall is supported on the threshold of a recess in the socket member with the lower wall of the recess being the holding part of said holders which engages with the ball at the opposite side of the plane of symmetry of the ball which is remote from the socket member and in that on the outer surface of the socket member a locking ring is slidably mounted and in a locked position of the joint is coupled with said holders.

Preferably, on the side of the ball which is remote from the socket member the lower channel walls of the holders are each shaped as a sector of a sphere whose radius is equal to the radius of the ball.

When the joint interconnects the prop and the sill piece the distance between the bottom of the prop and the upper surface of the locking ring is greater than the length of that part of the locking ring which is adjacent to the holders in the locked position of the joint.

The joint according to the invention is of a very simple and durable design due fo which it is very useful and easy to operate under difficult mining conditions and can be quickly released. It does not have any known screw joints or knuckle joints, which in mining operating conditions, corrode very quickly and increase the break-down rate of the hydraulic lining. The joint according to the invention renders it possible to replace quickly a broken-down prop from an automatized lining.

This has a very favourable effect upon increasing the regularity of mining fronts and in greater mining efficiency.

The joint may be disassembled to separate the prop from the sill piece by axial displacement of the locking ring upwards until the holders are completely exposed, i.e. disengaged from the locking ring. In this position the holders can be disconnected from the socket member by being moved in the radially outward direction to disconnect the prop from the sill piece.

In order that the invention may be more readily understood, reference will now be made to the accompanying drawings, in which: Fig. 1 is a part-sectional side elevation of one embodiment of joint constructed in accordance with the invention, and Fig. 2 is a part-sectional side elevation of another embodiment.

The joint shown in Fig. 1 comprises a socket member 3 having a part-spherical socket and being fixed to the prop 4. The socket member 3 rests on a ball 1 which engages in the socket of the socket member 3 and which is welded to a sill piece 2. The outer surface of the socket member 3 is of cylindrical form and is provided with a depression constituted by a recess in a form of an annular groove 7 which extends around the entire outer surface of the socket member. The groove 7 serves as a mounting seat for two holders 5 of segmental shape, made of sheet metal or bars and together encircling the ball 1 and socket member 3 and holding the ball in the socket. The holders 5 are of arcuate shape and in this embodiment extend for approximately one half of a circle i.e.

each extend for a segment of a circle, and are generally channel shaped in cross-section. The upper wall 8 of the channel in each holder 5 engages in the groove 7 to support the holders on the socket member 3. The lower wall 9 of the channel in each holder 5 projects towards the ball. The free end of each wall 9 is of partspherical shape and has a radius which is the same as the radius of the ball and engages the ball on that side of the horizontal plane of symmetry of the ball which is further from the socket member 3. The bottom wall of the channel abuts against the outer surface of the socket member 3, below the groove 7.The engagement of the upper walls 8 of the channels in the groove 7 ensures that the holders 5 cannot be displaced along the axis of the prop 4 and are prevented from displacement in the peripheral direction by means of a locking ring 6 having a stepped inner surface. The larger diameter portion 6a of the locking ring 6 slidably engages the outer surface of the socket member 3, the smaller diameter portion 6b of the locking ring slidably engages the outer surfaces of the holders 5 and the step in the ring engages that portion of the upper wall 8 of the channel in each holder 5 which projects from the groove 7.

The distance between the bottom of the prop 4 and the upper surface of the locking ring 6 is greater than the length of the smaller diameter portion 6b of the locking ring 6 which engages the outer surfaces of the holders 5 so that the locking ring 6 can be displaced upwards a sufficient distance for the lower end of the portion 6b to clear the holders 5 and permit release of the joint. The holders 5 are each provided with a flange 10 whose external diameter is at least equal to the external diameter of the locking ring 6, i.e. the flange projects radially outwardly for at least the same distance as the locking ring. The flange 10 prevents accidental release of the joint by pieces of the mined material, since those pieces could raise the locking ring 6 during advance of the roof-support unit.

In the embodiment illustrated in Fig. 2 the locking ring 6 and its inner surface which engages the socket member 3 and holders 5 is not stepped but is generally of cylindrical form and its lower end projects into a vertical arcuate groove 11 in the upper surfaces of the holders 5 facing the bottom of the prop 4.

It will be appreciated that various modifications may be made without departing from the scope of the invention as defined in the appended claims. For example, more than two segmental holders may be used. Instead of the annular mounting groove 7, separate recesses or holes may be provided in the outer surface of the socket member 3 at spaced intervals therearound.

In such cases, the upper walls 8 have appropriately shaped projections or cylindrical pins which enter the recesses or the holes in the socket member 3. Moreover, the locking ring and the outer surface of the socket member need not be of cylindrical shape but may be of polygonal shape, for example square. The locking ring may be of sheet metal and be of undulated form or have corrugations therein with the risers or convexities in the undulations or corrugations engaging the socket member 3 and with the depressions or concavities in the undulations or corrugations engaging the ball holders 5 or vice versa if the socket member has an external diameter which is greater than that of the ball holders.

Claims

1. A joint for interconnecting a prop and a sill piece in a mining roofsupport unit, having a socket member defining a part-spherical socket and a ball engaging in the socket, characterized in that at least two holders are removably mounted on the socket member and engage with the ball to hold the ball in the socket and in that a locking ring is slidably mounted on the socket member to be movable between a locking position in which the ball holders are engaged by the locking ring and are prevented from ,noving relative to the ball and a releasing position in which the locking ring is disengaged from the ball holders which can then be moved relative to the ball to release the joint.

2. A joint as claimed in claim 1, wherein each of the holders is generally of channel-shaped cross-section with one of the walls of the channel engaging in at least one depression in the outer surface of the socket member to support the holders on the socket member and with the other wall of the channel being disposed adjacent the ball on that side of the plane of symmetry of the ball which is further from the socket member.

3. A joint as claimed in claim 2, wherein the depression is in the form of a recess which extends entirely around the outer surface of the socket member.

4. A joint as claimed in claim 2, wherein the socket member has a plurality of said depressions therein which are in the form of recesses or holes extending at spaced intervals around the outer surface of the socket member, and said one channel wall of each socket member has projections or pins which engage in the recesess or holes respectively.

5. A joint as claimed in any one of claims 2 to 4, wherein the free end of said other wall of the channel of each holder is of part-spherical shape and has a radius which is at least substantially equal to that of the ball.

6. A joint as claimed in any one of claims 1 to 5, wherein the base wall of the channel of each 4erjroiectsoutwardlybeyond the outer surface of the socket member and wherein the inner surface of the locking ring is of stepped configuration with its portion of greater width engaging the outer surface of the socket member and with its portion of lesser width engaging the outer surface of the base wall of the channel.

7. A joint as claimed in any one of claims 1 to 5, wherein the locking ring, when considered in vertical cross-section, has a straight inner surface which engages the outer surface of the socket member and holders, the end of the ring which is nearer the holders engaging in grooves therein.

8. A joint as claimed in any one of claims 1 to 7, wherein the holders each have a flange beneath said at least one depression which projects outwardly for at least the same distance as the locking ring.

9. A joint as claimed in any one of claims 1 to 8, and interconnecting the prop with the sill piece, wherein the distance between the bottom of the prop and the upper surface of the locking ring is greater than the length of that part of the locking ring which is adjacent the holders.

10. A joint for interconnecting a prop and a sill piece in a mining roof-support unit, substantially as hereinbefore described with reference to Fig. 1 of the accompanying drawings.

1 A joint for interconnecting a prop and a sill piece in a mining roof-support unit, substantially as hereinbefore described with reference to Fig. 2 of the accompanying drawings.

12. A mining roof-support unit including a prop and a sill piece interconnected by a joint as claimed in any one of claims 1 to 11.