US3431737A - Hydraulic roof supports - Google Patents

Description

March 11, 1969 RBOWER 3,431,737

HYIJJRAULIC ROOF SUPPORTS File d Feb. 14, 1967 [nvenfor A ew/s Rainer? Bower Sheet 5 of 5 March 11, 1969 R. BOWER 3,431,737

HYDRAULI C ROOF SUPPORTS Filed Feb. 14, 1967 Sheet 2 of 5 FIGQ Lye/772; Zeal/ls l PoberfBower March 11, 1969 L. R. BOWER 3,431,737

HYDRAULIC ROOF SUPPORTS Filed Feb. 14, 1967 Sheet 3 of s FIG?! [r7 venfor Lew/'5' Robefl Bo wer United States Patent Office 3,431,737 Patented Mar. 11, 1969 4 Claims ABSTRACT OF THE DISCLOSURE An advancing mine roof support having a pair of hydraulic chocks joined by spring steel strips at floor and roof level, the strips bowed downwardly and upwardly respectively and held in the chocks by pins, some of the strips extending beyond one of the chocks and connected by a plate to form a support in advance of said one chock.

This invention relates to mine roof supports, and particularly though not exclusively to mine roof supports for use in longwall working in thin seams and intended to be attached to a face conveyor. The invention finds particular application in underground coal mines, but can be applied in any form of underground mineral mining where working methods akin to those of coal mining are adopted.

It is one object of this invention to provide a mine roof support adapted for low mine seams and one which is flexible and can adapt itself to irregularities in the mine floor or roof.

Another object is to provide a mine roof support of the self advancing type with provisions to support the roof over the face conveyor in advance of the forward chock.

According to the invention we provide a mine roof support comprising at least two fluid operated chocks each of which has a roof canopy whose underside has a groove, the chocks being joined by a roof-contacting member in the form of a strip of spring steel which is at least partly located in the groove.

In a preferred form of the invention, the strip of spring steel is so located by means of one or more removable pins. These pins seat in suitable apertures in the roof canopy, or in suitable brackets or the like secured thereto. The strip of spring steel may have a turned-over end through which an additional pin can pass to make the spring steel strip captive to the canopy.

Further features of the invention will appear from the following illustrative and particular description thereof given with reference to the accompanying drawings, in which:

FIG. 1 is a side elevation of one form of roof support according to the invention,

FIG. 2 is a plan view of the support shown in FIG. 1,

FIG. 3 is a side elevation of the support shown in FIG. 1 showing particularly the arrangement and construction of the floor and roof level outer spring sets,

FIG. '4 shows the support shown in FIGS. 1 and 2 and particularly shows the arrangement of the central springs at floor and roof level.

The illustrated mine roof support comprises a front hydraulic chock and a rear hydraulic chock 12, the former of which has a base 14 and a roof canopy 16 and the latter of which has a base 18 and a roof canopy 20. Spring steel sets generally indicated at 22, 24 and 26- in FIG. 2 extend between these roof canopies and two pairs of spring steel strips, one pair generally indicate-d at 30 and the other pair at 50, extend between the base members. The strips are located beneath springs 22 and 26 and the springs 30 are spaced inwardly therefrom as seen in FIG. 2. In an alternative embodiment, not illllllstrajted, the support could comprise three chocks in line a ea An extension plate assembly 34 is mounted at the forward end of cantilever springs 22, 26 and in use gives support to the roof above the face conveyor.

As seen best in FIG. 3, the outer spring sets at roof level are each made up of three springs 32, 34 and 36, the upper two extending between the front and rear roof canopies and beyond the front, and the third spring 36 being attached to the front roof canopy and serving as a cantilever support. The outer pair of springs 50 at floor level extends between pins 40, 42 one pin being mounted in a side wall 44 -(see FIG. 1) on the front base member and one being removably mounted in a side wall 46 on the rear base member. These pins extend respectively between outer side walls 44 and 46 and inner side walls (not referenced).

The central springs are seen best in FIG. 4 and are located on or symmetrical to the centreline of the support. They comprise one roof spring 24 and two floor springs 30 somewhat inset from the spring strips 50-. Each spring 30 extend between pins 52 on the respective base members. The spring 24 extends between pins 53 on the respective roof canopies. In common with the remaining springs (except 36) the springs 24, 30 and 50 are preformed to a shape such that they present a convex surface towards roof or floor extending beyond the plane of the upper surface of the roof canopies 16, 20 or the plane of the lower surface of the base members 14, 18 as the case may be. The number and width of the upper and lower centre springs can be adjusted in order to suit varying floor and roof conditions.

The upper portions of the chocks 10 and 12 are formed in the shape of a flat cone having in the centre a raised portion which acts as a centralising and retaining boss for the roof canopies 16, 20, the shape of the said portions and the design of the roof canopies being such as to allow the canopies a certain amount of universal pivotal movement.

As can be seen from FIG. 2, the undersides of the roof canopies have grooves in which part of the spring steel strips are located, in that the canopies are provided with downwardly projecting plates or brackets which form the side walls of the grooves. Mechanical equivalents of such a construction are deemed to be within the scope of the present invention.

The base members 14 and 18 have similar open grooves, however opening upwardly in this case, to receive the floor level springs 50.

In the preferred embodiment of this invention, it has been mentioned that the roof level spring sets comprise three individual springs, the uppermost of which (32) has an eye formed at its rear extremity. The second spring of this set, namely 34, also has an eye formed at its rear extremity, this eye being so sized that it can be received within the eye formed in spring 32. A removable pin 54 makes these two springs captive to the roof member 20. The cantilever spring 36 is located by an eye formed at its rear end engaged by a removable pin 56, and this spring and the springs 32 and 34 are all supported by a generally horizontal removable pin 58. In operation, a supporting pin 61 and the supporting pin 58 form fulcrums when loading is applied to the arched portions of springs 32 and 34, as for instance upon setting of the chocks to the roof, and pin 58 forms a fulcrum point for all three springs when the cantilever portions 34 is similarly deflected by contact with the roof.

The outer springs at floor level (50) are positioned, as stated, directly below the outer spring sets 22 and 26 at roof level, and are formed with an eye at each end of a size appropriately chosen in relation to removable pins 40, 42.

Referring to FIG. 2, on either side of the roof support are seen double acting hydraulic rams 60, 62 each of which is attached to an attachment plate, 64, 66. These parts function to effect steering of the roof support dur ing forward movement.

The construction specifically described herein has the important practical advantages that the whole roof support is constructed of simple parts and is easily dismantled, for example for routine maintenance, Replacement of roof or floor springs is particularly simple as it is 1 merely necessary to withdraw the appropriate removable pin or pins.

I claim:

1. An advancing mine roof support comprising at least a forward and a rearward fluid-operated chock each of which has a roof canopy whose underside has at least one groove, the chocks being joined by a plurality of roofcontacting members in the form of strips of spring steel, and by a plurality of floor-contacting members in the form of strips of spring steel, each of the laterally outermost roof contacting members bein at least partly located in a corresponding one of the grooves, and the said outermost roof-contacting members projecting beyond the forward chock and a plate supported on and extending between them which in operation serves to provide support to the roof in advance of the forward chock.

2. A support according to claim 1 in which each roof contacting strip is preformed to a shape such that it presents a convex surface towards roof and extends beyond the plane of the upper surface of the roof canopies and each floor contacting strip presents a convex surface toward the floor and extends beyond the plane of the lower surface of the floor contacting members.

3. A support according to claim 2 which includes four parallel strips at floor level and three at roof level joining the chocks.

4. A support according to claim 1 in which the outermost strip-s at roof level each have a turned-over end in the form of a loop, a pin in said canopy and passing through said loop to render the said strip captive to the canopy and in which a further pin is provided in said canopy to maintain each said strip in its associated groove.

References Cited UNITED STATES PATENTS OTHER REFERENCES M24317, V1/5c, 8-1956, German patent application to Muller et 211., 61-45.

JACOB SHAPIRO, Primary Examiner.

US. Cl. X.R. 248-357

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