US3364683A

US3364683A - Advanceable roof support suitable for use in mines

Info

Publication number: US3364683A
Application number: US443421A
Authority: US
Inventors: Farr Peter
Original assignee: Dowty Mining Equipment Ltd
Current assignee: Dowty Mining Equipment Ltd
Priority date: 1964-03-31
Filing date: 1965-03-29
Publication date: 1968-01-23
Anticipated expiration: 1985-01-23
Also published as: GB1091603A

Description

P. FARR Jan. 23, 1968 ADVANCEABLE ROOF SUPPORT SUITABLE FOR USE IN MINES 2 Sheets-Sheet 1 Filed March 29, 1965 IMVEMTOQ VErE/e FAKK whm ATToamav Jan. 23, .1968

Filed March 29, 1965 P. FARR 3,364,683

ADVANCEABLE ROOF SUPPORT SUITABLE FOR USE IN MINES 2 Sheets-Sheet 2 INVEM'TOE Para F'AEK ATToewzy United States Patent 3,364,683 ADVANCEABLE ROOF SUPPORT SUITABLE FOR USE IN MENES Peter Farr, Cheltenham, England, assignor to Dowty Mining Equipment Limited, Ashchurch, Tewi-xesbury, Engiand, a British company Filed Mar. 29, 1965, Ser. I o. 443,421 Claims priority, application Great Britain, Miar. 31, B64, 13,1'77/64 11 Claims. (Cl. 61-45) ABSTRACT OF THE DISCLOSURE During advance of individual roof supports, such as are pivotally connected to the conveyor, such a roof support tends to slew about its pivotal connection. For proper support of the roof and coordination of the successive roof supports any such tendency to slew about should be counteracted, and the roof supports when reset in their ultimate advanced positions should be left in parallelism to one another, each perpendicular to the working face of the mine and to the ultimate advanced position of the conveyor.

Various attempts have been made to guide the roof supports as they advance so that they do not slew about, but this is likely to set up binding in the guide means, of such nature as to prevent proper advance, and to require corrective measures that are rather dangerous to miners. There have been other attempts to permit slewing, followed by realignment by interengagement between an advancing roof support and one or more temporarily fixedly positioned roof supports.

According to the present invention each individual roof support incorporates means that reacts between the same and a part of its own advancing means to effect realignment automatically, within each given roof support, as its advance proceeds. This is achieved by utilizing spaced abutments on one part of the jack that efiects advance, that cooperate with complemental abutments carried by the floor-engaging member but which are spaced somewhat farther apart (in the direction of advance) than the first-mentioned abutments, whereby some slight relative shifting axially of the one part of the jack with respect to the floor support is effected. Thereby slewing of the jack about the pivotal connection of its other part to the conveyor is permitted; the abutments are so mounted as to be free to move vertically to accommodate roughness of the floor, but not horizontally. Slewing is also produced by a couple that develops during advance by reason of the location of the pivotal 0onnec tion of the jack to the conveyor at a point off-set from the thrust axis of the jack. At the same time that tendency to slew about is counteracted and reduced, and the roof support is restored to its correct disposition, by reaction between a profiled surface of one of the abutments and its complemental abutment.

Detailed description This invention relates to mining equipment, especially such as includes advanceable roof support assemblies and alternatively advanceable snakeable conveyors that serve as anchorages.

Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings of which,

FIGURE 1 is a plan view of a roof support assembly secured to a conveyor,

FIGURE 2 is a side view of a part of the roof support assembly of FIGURE 1,

FIGURE 3 is a plan view of part of a floor beam of 'ice a modified roof support assembly (with a steering arm omitted),

FIGURE 4 is a sectional view of the floor beam along the line 4-4 of FIGURE 3,

FIGURE 5 is a plan view of the steering arm for use with the floor beam shown in FIGURE 3, and

FIGURE 6 is a side view of the steering arm shown in FIGURE 5.

With reference to the accompanying drawings, FIG- URES 1 and 2 show a mine roof support assembly including an advanceable roof support 1 to which is secured a iiuid-pressure-operated piston-and-cylinder jack 2. The roof support 1 includes two spaced-apart floor beams 3, 4 which are parallel to one another and to the direction in which the roof support advances. The floor beams 3, 4 are rigidly connected by connecting means 5. The floor beam 3 carries three fluid-pressure-operated props 6, one behind the other, and the floor beam 4 carries two fluidpressure-operated props 7, one behind the other. The rear ends of the floor beams 3, 4 are laterally aligned, but the floor beam 3 is longer than the floor beam 4. The front prop 7 is laterally aligned with the rear prop 6. The front prop 6 is carried by a portion of the floor beam 3 which projects beyond the floor beam Each prop 6, 7 is mounted in a resilient prop mounting 3 carried by the respective floor beam 3, 4 such that each prop 6, 7 is resiliently urged to a predetermined angular position relative to the respective floor beam 3, 4 and is capable of a limited amount of angular movement from its predetermined angular position. The prop mounting 8 has not been shown in detail, as such mountings are well-known.

The middle and rear props 6 and the two props 7 carry a roof canopy 9 in such a manner that they are capable of a limited amount of angular movement relative to the canopy 9. The front prop 6 carries a roof bearn 11 connected to the canopy 9 by a hinge 12 such that the roof beam 11 and canopy 9 are capable of relative angular movement about an axis extending laterally of the direction of advance. The front prop 6 is capable of a limited amount of angular movement relative to the roof beam 11.

A roof support with two floor beams rigidly connected together by connecting means is the subject of US. patent application of T. D. H. Andrews, Ser. No. 430,922, filed Feb. 8, 1965.

The cylinder 13 of the jack 2 has a spigot 14 at its rear end which is located in a slot formed by two upstanding lugs 15 secured to the connecting means 5. This enables the jack 2 to move angularly relative to the roof support by a limited amount about a vertical axis and to move by a limited amount vertically and also horizontally relative to the roof support.

A steering arm 16 is carried by the floor beam 3 at a position just behind the front prop 6. The steering arm 16 extends towards the floor beam 4 across and above the front end portion of the jack cylinder 13. This front end portion of the jack cylinder 13 has two blocks 17 secured thereto, one one each side of the centre line of the cylinder 13, the purpose of which is to provide flat surfaces on which the steering arm 16 rests. Also, two upstanding lugs 18 are secured to the cylinder 13 at positions spaced in a manner to be described from the lugs 15, and the two lugs 18 carry a retainer 19 which extends forwardly over the blocks 17 and over the steering arm 16, to prevent that arm rising from the position where lugs 18 can contact it.

The forwardly-facing surfaces of the lugs 18 and the rearwardly-facing surface of the steering arm 16 are shaped for a purpose which will be described later. An end portion of the steering arm 16 is located in a slot 21 in the floor beam 3 and has a projection 22 which is located in a further slot 23 communicating with the slot 21. The steering arm 16 is thereby capable of angular movement about an axis passing through the projection 22 and of vertical movement in the slots 21, 23. The opposite end portion of the steering arm 16 has a stop 24- which limits angular movement of the jack 2 relative to the roof support 1.

The piston rod of the jack 2 has an offset portion 26 at its free end, and this offset portion 26 is pivotally attached to a conveyor 27 by a pin 28, the axis whereof is upright.

In FIGURES 1 and 2, the jack 2 is in its fully contracted condition and the roof support 1 is in a fully-advanced position relative to the conveyor 27. FIGURE 1 shows the initial position of the jack 2' when the jack 2 has been supplied with fiuid under pressure in a jack-extending sense to advance the conveyor 27, the roof support 1 being in a roof-supporting condition with all its props 6, 7 set. The jack cylinder 13- has moved rearwardly with the rear end of the jack cylinder 13 abutting the lugs 15. The lugs 18 at this time are spaced from the steering arm 16-. Thus, as the conveyor 27 then advances, the jack 2 reacts against the lugs 15, pushes at the pin 28, and can move angularly by an amount predetermined by the shape of the lugs 15.

When the conveyor 27 has been advanced, the props 6, 7 are released so that the canopy 9 and roof beam 11 are lowered from the roof, and fluid under pressure is then supplied to the jack 2 in a jack-contracting sense. Initially, the jack cylinder 13 moves forwardly until the front surfaces of the lugs 18 abut the rear surface of the steering arm 16, the rear end of the cylinder 13 then being spaced from the lugs 15. The jack-contracting force is then transmitted through the steering arm 16 to the roof support 1 with the result that the roof support 1 advances towards the conveyor 2 Owing to the presence of the offset portion 26 secured to the piston rod 25, the line of action of the force exerted by the jack 2 does not pass through the pin 28, and the resultant couple tends to balance the couple caused because the centre of friction between the roof support 1 and the floor is displaced from the line of action of the force exerted by the jack in the direction of the fioor beam 3.

If the roof support 1 does tend to slew about the intended direction of advance parallel to the line of action of the jack 2, the relative movement between the shaped front surfaces of the lugs 18 and the shaped rear surface of the steering arm 16 causes the advancing force exerted by the jack 2 through the steering arm 16 on the roof support 1 to have a component tending to correct the slewing movement. Such slewing may be caused, for example, by unevenness in the floor. When such unevenness is encountered, the steering arm 16 can move angularly and vertically in the slots 21, 23, as previously described.

FIGURES 3 to 6 show a modified steering arm 31 and door beam 32. An end portion 33 of the steering arm 31 fits into a slot 34 in the floor beam 32 and has a projection 35 which fits into a further slot 36 communicating with the slot 34. The rear portion 38 of the slot 34 has less depth than the remainder of the slot 34. The arrangement is such that upward angular movement of the steering arm 31 about projection 35 by more than a predetermined amount causes the projection 35 to move upwardly out of the slot 36, with the result that the steering arm 31 becomes disconnected from the floor beam 32. Such upward angular movement of the steering arm 31 may occur with an exceptionally uneven floor, and the disconnection of the steering arm 31 from the floor beam 32 prevents damage to the jack and steering arm 31.

The conveyor 27 may have parts which, during the last part of the advance of the roof support, override the operation of the steering arm 16 and align the roof support 1 in a desired manner with the conveyor 27. When the roof support 1 has been reset against the roof after its advance, the roof support and the parts of the conveyor 27 may co-operate to prevent movement of the conveyor 27 in a direction perpendicular to the direction of advance.

What I claim is:

1. Mining equipment including, in combination, an advanceable anchorage and an advanceable roof support, said roof support having a floor-engaging member and at least one telescopic prop carried by the floor-engaging member, a telescopic jack including a first and a complemental second part, for advancing each of the floorengaging members and the anchorage by reaction of one to the other, said first part of said jack being pivotally connected to said anchorage, and hence capable of slewing laterally with respect to the direction of advance, and the second part being connected to said floor-engaging member, one end portion of said second part being remote from the anchorage, said remote end portion and an adjacent part of the floor-engaging member having complemental abutments, and the opposite end portion of the second part, that nearer the anchorage, and an adjacent part of the floor-engaging member, also having complemental abutments, the several abutments being so spaced that when the abutments at one end are abutted, those at the opposite end are spaced apart, and vice versa, one of the abutments at such nearer end being angularly directed with respect to its complemental abutment to guide advancing movement of the floor-engaging member to counteract any lateral slewing of the jack and of the connected floor-engaging member.

2. Mining equipment as in claim 1, wherein the pivotal connection of the first part of the jack to the anchorage is offset from the line of thrust of the jack, and the abutment carried by the floor-engaging member at such nearer end is bowed concavely with respect to its complemental abutment.

3. Mining equipment as in claim 1, wherein props on the floor-engaging member are arranged in two parallel rows directed in the direction of advance, one such row being longer than the other, the jack being disposed to the side of the shorter row that corresponds to the longer row, and the pivotal connection of the jack to the anchorage being offset from the jacks line of thrust towards the longer row, the abutment carried by the floor-engaging member at such opposite end being bowed concavely with respect to the complemental abutment to counteract the slewing tendency produced by the offset location of the jack and its pivotal connection.

4. Mining equipment as in claim 1, wherein the abutment carried by the floor-engaging member at such nearer end is the one that is angularly directed.

5. Mining equipment as in claim 4, wherein the angularly directed abutment is separate from the floorengaging member, and means supporting said abutment from said floor-engaging member for freedom of up and down movement of the abutment relative to the floorengaging member, but restraining relative horizontal movement.

6. Mining equipment as in claim 5, wherein the means: supporting the angularly directed abutment is arranged for pivotal movement about a horizontal axis.

7. Mining equipment as in claim 6, wherein the means. supporting the angularly directed abutment is also arranged for its additional bodily vertical movement.

8. Mining equipment as in claim 7, wherein the angularly directed abutment is carried upon one end of an arm, the floor-engaging member being formed with a transversely directed upright slot wherein the arms opposite end is received for vertical movement, a pivot projection from said opposite end being received in a second upright slot angularly related to the first slot, for pivotal movement.

9. Mining equipment as in claim 8, including means to limit upward movement of the slot-confined end of the arm, to effect release of the pivot projection from its second slot in the event of excessive vertical movement of the arm.

19. fining equipment including in combination, a snakea'ole conveyor, an advanceable roof support having releasable means settabie between the floor and the roof, a two-part telescopic jack a first part whereof is connected at its forward end to said conveyor, its second part having a forward and a rearward bearing surface, said bearing surfaces being spaced apart lengthwise of the jacks second part by a given distance, a forward and a rearward thrust-receiving surfaces carried by the roof support in position to receive thrust from the respective bearing surfaces, said thrust-receiving surfaces being spaced apart a distance in excess of the spacing of said bearing surfaces, whereby as either pair of bearing and thrust-receiving surfaces is engaged, the other pair is disengaged.

11. Mining equipment including in combination, a snakeable conveyor, an advanceable roof support having releasable means settable between the floor and the roof, a telescopic fluid-pressure jack the piston whereof is connected at its forward end to said conveyor, forward and rearward bearing surfaces upon the jack cylinder spaced apart by a given distance, thrust-receiving surfaces carried by the roof support in position to receive thrust from the respective bearing surfaces, upon the jack cylinder that are complementai to each such bearing surface but spaced apart a distance sufiiciently in excess of the spacing between said bearing surfaces that as the complemental rearward surfaces are engaged during advance of the conveyor the complemental forward surfaces are spaced apart, to permit slewing of the roof support, and vice versa, as the forward surfaces are engaged during advance of the roof support the rearward surfaces are spaced apart, the forward surfaces being angularly directed to counteract any slewing by their interengagernent.

References Cited UNETED STATES PATENTS 2,910,281 16/1959 \Vilkenloh et al. 2621 3,113,661 12/1963 Linlze et al. 198-126 FOREIGN PATENTS 1,363,750 6/1964 France.

DAVID J. VJILLIAMOVVSKY, Primary Examiner.