US3355898A

US3355898A - Roof support assembly

Info

Publication number: US3355898A
Application number: US507730A
Authority: US
Inventors: Wesley H Barrett; Law Kenneth
Original assignee: Dowty Mining Equipment Ltd
Current assignee: Dowty Mining Equipment Ltd
Priority date: 1964-11-17
Filing date: 1965-11-15
Publication date: 1967-12-05
Anticipated expiration: 1984-12-05
Also published as: GB1059557A

Description

Dec. 5, 1967 H. BARRETT ETAL 3,355,898

ROOF SUPPORT ASSEMBLY Filed Nov. 15', 1965 INVENTORS wEsL-Ey he 'BAKK'Eff llEN ETH LA w BY ATTORNEY United States Patent 3,355,898 ROOF SUPPORT ASSEMBLY Wesley H. Barrett, Cheltenham, and Kenneth Law, Tewkesbury, England, assignors t0 Dowty Mining Equipment Limited, Tewkesbury, England, a British company Filed Nov. 15, 1965, Ser. No. 507,730 Claims priority, application Great Britain, Nov. 17, 1964, 46,777/64 Claims. (Cl. 61-45) ABSTRACT OF THE DISCLOSURE According to this invention a guide member disposed between one roof support and the next is connected to a fixed anchorage, such as the conveyor becomes during the advance of a roof support. The manner in which the guide is associated with the conveyor (pivotally) and the manner in which that guide is associated with the support (guide rollers engaging and embracing the I-section at one point in the length of the guide) takes into account the possible happenings during snaking of the conveyor and during advance of a support. By the construction described in detail hereinafter, when two adjacent sup ports are set against the roof, and the part of the conveyor in front of them is snaked, two rollers carried upon these supports are opposite to each other on the I-beam, and their rollers provide a very short overlap on the I-beam (virtually line contact) and the beam can therefore move with the conveyor along the S-bend referred to hereinafter. When a given roof support is advanced towards the conveyor, adjacent roof supports will be set against the roof, and the guides on either side will allow only a limited amount of lateral sliding of the advancing roof support to occur. Further, and preferably but still optionally, realignment of the support is aided by certain wedge-shaped members carried by the I-beam.

Interengagement between the individual supports and the guides allows vertical and pivotal movement of one relative to the other, to further eliminate stresses.

Background 0 the invention divider 61 thus controls conduction in transistor Q2 and SCR Q1 during those half cycles when line L3 is positive with respect to ground and SCR can apply power to winding RY2. Similarly, voltage divider 63 controls con- This invention concerns the so-called long-wall system of mining, wherein a coal cutter advances along a coal face of indeterminate length, to deposit the coal which is out upon a. conveyor that extends from end to end of the coal face. The conveyor is of the snakeable type, such as is advanced by increments towards the coal face behind the advancing cutter. At equal intervals along the length of the coal face, at the side of the conveyor remote from the coal face, are disposed roof-supporting assemblies which are directed generally in parallelism towards the coal face, and which must successively serve as anchorages for the application of force to advance the conveyor portion immediately in advance thereof, and then must individually be themselves advanced, by reaction from the conveyor and the other roof supports, to a new roof-supporting position. It will be clear that if the mine floor slopes lengthwise of the coal face, say downwardly from left to right, there will be a tendency for advancing roof supports to slide laterally (to the right) of their direction of advance.

This tendency can produce certain undesirable results, and has heretofore in constructions wherein a guide eleent paralleling the direction of advance is closely slidably connectedespecia1ly if so connected at two points in its length-to one or to both roof support assemblies. The lateral sliding of an advancing roof support, occurring by reason of the effect of gravity as the roof support slides over the sloping and irregular floor, sets up stresses that can prevent advance, and that must be relieved, or the frozen elements replaced, before advance can continue. Such relief or replacement can be dangerous to a miner attempting it, and is likely to interrupt or slow down the mining operation.

According to this invention this undesirable result is avoided by allowing the guide element to move flexibly relative to the conveyor, as by being pin-jointed thereto at its one end, and by interengaging each of two adjacent roof support assemblies with that guide element at a single point in its length, with provision for free vertical movement at each such point of engagement, but not for any substantial lateral movement. Since one of the two roof support assemblies thus paired is set or fixed in position while the other one advances, and vice versa, it will be clear that the advancing one is guided by the fixed one through the guide element that is guided upon the fixed one, and so lateral displacement cannot occur. By connecting the individual roof support assemblies, through their advancing means, such as double-acting jacks, in like pin-joint manner to the conveyor, flexibility to accommodate irregularities in the floor is achieved, yet the guiding interengagement is such that any substantial lateral displacement of free ends is prevented, and bending or binding cannot occur. As a refinement, wedgeshaped guides may be arranged to counteract any slight lateral displacement of the guide member or of roof support assemblies that may occur.

Since each roof support is pin-jointed at its advancing end to the conveyor, its trailing end must be free, and can swing laterally relative to the conveyor during snaking. The point of attachment to the conveyor of the jack that connects them does not advance in a straight line, but traces out an S-bend. The amplitude of this movement is not predictable, nor is it certain that the advanced position of this point of attachment will be immediately in front of its initial position when the advance starts; it may be to the right or to the left of the initial position. Good support of the roof requires that any lateral slippage of one or more roof supports be corrected, and that the slipped roof support be realigned with-i.e., set substantially perpendicular tothe conveyor after it has completed its advancing operation. The present invention does this, and maintains the correct orientation between the individual roof support, their guides, and the conveyor.

FIGURE 1 is a diagrammatic support assembly, and

FIGURE 2 is a sectional view on an enlarged scale along the line 2-2 of FIGURE 1.

Referring to the accompanying drawings, wherein an example of the invention is shown, a mine roof support assembly includes two laterally-spaced roof. supports 1, 2. The roof support 1 has two laterally-spaced

floor beams

3, 4 connected by a cross member 5, and each

floor beam

3, 4 carries three fluid-pressure-operated props 6, 7 respectively. The props 6, 7 carry a roof member assembly (not shown). A fluid-pressure-operated advancing jack 8 extends between the two

floor beams

3, 4, and the end portion 9 of the piston rod of the jack 8 which projects from its cylinder 11 is connected to the floor beams 3,fiexible' means such as-4 by four

chains

12, 13, 14, 15. The chains the end portion 9 to the plan view of a

mine roof

12,13 extend forwardly from able conveyor 17 with extends along the working face of the mine. The pivotal connection between the cylinder 11 and the conveyor 17, besides allowing relative pivotal movement laterally, or in a substantially horizontal plane, also allows a limited amount of relative vertical movement. The jack cylinder 11 may have laterallyextending wedge shaped guides 18 which align the roof support 1, during its advance, with the conveyor 17, as will be described later.

As so far described, the roof support 1 is identical with the roof support 2 and the same reference numerals are used for those parts of the roof support 2 which have previously been described with reference to the roof support 1.

Between the two roof supports 1, 2, that is to say between the floor beam 4 of the roof support 1 and the floor beam 3 of the roof support 2, extends a guide member 19 which is pivotably connected at one end to the conveyor 17 by a pin 21. The guide member 19 has an H-shaped or I beam across section formed by two laterally-spaced vertical side or

flange portions

22, 23 connected by a horizontal web portion 24. The end portion of the guide member 19 adjacent the conveyor 17 preferably has two laterally-extending wedge shaped guides 20 which assist in aligning the roof supports 1, 2, during their advance, with the conveyor 17, as will be described later. The pivot-al connection between the guide member 19 and the conveyor 17, besides allowing relative pivotal movement in a substantially horizontal plane, also allows a limited amount of relative vertical movement.

The floor beam 4 of the roof support 1 carries a guide assembly 30 including a bracket 25 bolted to the side of the floor beam 4 facing the floor beam 3 of the roof support 2. The bracket 25 has two side portions 26 (only one of which is shown) which are spaced in a direction parallel to the length of the floor beam 4, and are directed laterally in vertical planes. Each side portion 26 has a vertical slot 27, and a pin 28 has one end portion in one such slot 27 and the other end portion in the other slot 27. A claw member 29 mounted on the pin 28 between the side portions 26 has two vertically spaced arms 31a, 31b, the arm 31a being located above the flange 22 of the guide member 19 and the arm 31b being located below the flange 22. The arm 31a has a downwardly projecting shaft 32 carrying a roller 33 engageable with the inner surface of the upper part of the flange 22, above the web 24, and the arm 31b has an upwardly projecting shaft 34 carrying a roller 35 engageable with the inner surface of the lower part of the flange 22, below the web 24. A distance piece as located between the arms 31a, 31b is engageable with the outer surface of the flange 22. As can be seen from FIGURE 2, the guide member 19 is a loose fit in the guide assembly 30.

The floor beam 3 of the roof support 2 carries a similar guide assembly 30 for whose parts the same reference numerals are used as have been used for the guide assembly 30 carried by the floor beam 4 of the roof support 1. The drawing of the guide assembly 30 carried by the floor beam 3 of the roof support 2 shows that the bracket 25 is bolted to the floor beam 3 by bolts 37 with spacers 38 between the bracket 25 and the side of the floor beam 3. The roller 33 in the guide assembly 30 carried by the roof support 2 is engageable with the inner surface of the upper part of the flange 23 of the guide member 19, the roller 35 is engageable with the inner surface of the lower part of the flange 23, and the distance piece 36 is engageable with the outer surface of the flange 23.

Assuming that the relative positions of the conveyor 17 and the roof supports 1, 2 are as shown in FIGURE 1, and that the roof supports 1, 2 are set as anchors against the roof, the conveyor 17 is first advanced by extending the jacks 8 associated with the roof supports 1, 2. The advance of the conveyor 17 also results in the advance of the guide member 19 relative to the guide assemblies 30. As the conveyor 17 advances, the wedge shaped

guides

18 and 20 become progressively more spaced from the

relevant floor beams

3, 4, and a limited amount of lateral movement of the conveyor 17 (due to lateral slope of the floor, for example) relative to the roof supports 1, 2 can occur without damage to the jacks 11. v

After the conveyor 17 has been advanced, each roof support 1, 2 is advanced in turn. To advance the roof support 1, its props 6, 7 are first released from a roof supporting condition, and then the associated jack 8 is contracted to advance the roof support 1 towards the conveyor 17 which acts as an anchorage. If for example, the mine floor is sloping downhill in a direction from left to right in FIGURE 1, the roof support 1 will tend to slide downhill or towards the right during its advance. However, the associated guide assembly 30 and the guide member 19 will prevent this since the distance piece 36 will engage the outer surface of the flange 22. The guide member 19 is held against lateral pivotal movement by the guide assembly 30 of the roof support 2 (apart from a very slight lateral movement resulting from the loose fits of the guide assemblies 30 on the guide member 19), since the roof support 2 is set against the roof. Towards the end of the advance of roof support 1, the

floor beams

3, 4 of the roof support 1 are aligned with that is to say, are urged laterally with respect to the conveyor 17, to compensate for any previous lateral slippage, by the as'-

sociated guides

18, 20. After the advance, the props 6, 7 of the roof support 1 are returned to a roof-sup porting condition.

The roof support 2 is then advanced. Its props 6, 7 are released from a roof-supporting condition and its jack 8 is contracted. During the advance, the roof sup port 2 is prevented from sliding downhill by the inter action of its guide assembly 30 and the guide member 19, by the engagement of the

rollers

32, 35 with the inner surface of the flange 23, and by the interaction of a guide 19 at the right of support 2 with the next right roof support. The guide member 19 is held against lateral pivotal movement by the guide assembly 30 of the roof support 1 which is set against the roof.

The freedom of movement in a vertical sense of the pins 28 in the slots 27 of the guide assemblies 30, and of the jack cylinders 11 and guide member 19 relative to the conveyor 17, enables relative vertical movement between the conveyor 17 and the advancing roof support to or stressing of occur, without damage to the jacks 8 or guide member 19. Such relative vertical movement may be caused by uneveness of the floor.

If desired, each roof support may have two guide assemblies 30 engaging the guide member 19, the guide assemblies 30 being located at positions which are spaced apart along the length of the relevent floor beams.

Also, the roof support assembly may include a sec- 0nd guide member which is located above and is carried by the guide member 19, each roof support having one or more further guide assemblies 30 slidably connected to the second guide member. Such an arrangement can be used to reduce the likelihood of the roof supports toppling sidewise in a steep mine seam.

Further the jack cylinders 11 and the guide member 18 may be slidably pivotably connected to the conveyor 17, so that if the conveyor 17 has moved to the left or right in FIGURE 1 relative to the roof supports 1, 2 after one or more advances, the pivoted connections can be moved along the conveyor 17 to re-align the jacks 8 and guide member 19 parallel to the desired direction of advance.

We claim: 7

1. In combination with two individually advanceable and laterally spaced roof support assemblies and a snakeably advanceable anchorage, suitable for use in mines the floor whereof slopes laterally with respect to the direction of advance, means extending in the direction of advance and connected at one end to said anchorage and at its opposite end to each roof support assembly, said means being operable to advance each individual roof support assembly relative to the other, and to advance said anchorage relative to the roof support assemblies, and guide means including an element extending in the direction of advance and connected at one end to said anchorage, said guide means also including a cooperating guide assembly and means connecting the same to each roof support assembly, said guide assembly and said connecting means including means arranged to allow free vertical but substantially no lateral movement of either roof support assembly relative to the other during advance, whereby to prevent substantial lateral slippage of either roof support assembly.

2. The combination of claim 1, wherein the points of connection of the cooperating guide assemblies with the element are opposite one another, distant from the point of connection of the element to the anchorage.

3. The combination of claim 2, wherein all points of connection are arranged as pivotal connections swingable about upright axes.

4. The combination of claim 3, wherein the cooperating guide assemblies are arranged for relative vertical movement with respect to the roof support assembly with which they are interconnected, but not for relative lateral movement.

5. A roof support assembly according to claim 1 wherein the guide member is pivotably connected to the anchorage such that the guide member is capable of pivotal movement relative to the conveyor in a substantially horizontal plane.

6. The combination of claim 1, including spreader means carried by said guide element and engageable with the respective roof support assemblies during relative movement between such roof support assemblies and the guide element in the direction of advance, to deflect the advancing one thereof laterally in the event of its departure from the direction of advance.

7. The combination of claim 6, wherein each roof support assembly includes two individual roof supports, and further spreader means interposed between and engageable with said two roof supports, and also extending in the direction of advance, said spreader means being connected at one end to the anchorage for limited lateral movement of its opposite end.

8. The combination of claim 7, and flexible means flxing such opposite end of the advancing means with relation to the ends of each roof support that are distant from the connection of the advancing means to the anchorage.

9. The combination of claim 8, wherein the guide element is of H-shape in cross section, disposed with the flanges in vertical planes, and each guide assembly includes a claw vertically shiftable relative to and extending from its roof support assembly about the flange at the corresponding side to engage the flanges inner surface for free relative movement lengthwise of the guide element.

10. The combination of claim 9, including pin and slot means interconnecting each claw and its roof support assembly for limited vertical movement of the claw relative to said roof support assembly.

References Cited UNITED STATES PATENTS 2,324,207 7/1943 Gsell 248-430 3,106,825 10/1963 Barall et al. 6145 3,192,721 7/1965 Gaskell a- 61-45 3,197,965 8/1965 Lee et al. 61--45 3,201,943 8/1965 Wilkenloh et al. 61-45 FOREIGN PATENTS 1,159,884 12/1963 Germany. 1,164,959 3/ 1964 Germany.

ROY D. FRAZIER, Primary Examiner. R. P. SEITTER, Assistant Examiner.

Claims

1. IN COMBINATION WITH TWO INDIVIDUALLY ADVANCEABLE AND LATERALLY SPACED ROOF SUPPORT ASSEMBLIES AND A SNAKEABLY ADVANCEABLE ANCHORAGE, SUITABLE FOR USE IN MINES THE FLOOR WHEREOF SLOPES LATERALLY WITH RESPECT TO THE DIRECTION OF ADVANCE, MEANS EXTENDING IN THE DIRECTION OF ADVANCE AND CONNECTED AT ONE END TO SAID ANCHORAGE AND AT ITS OPPOSITE END TO EACH ROOF SUPPORT ASSEMBLY, SAID MEANS BEING OPERABLE TO ADVANCE EACH INDIVIDUAL ROOF SUPPORT ASSEMBLY RELATIVE TO THE OTHER, AND TO ADVANCE SAID ANCHORAGE RELATIVE TO THE ROOF SUPPORT ASSEMBLIES, AND GUIDE MEANS INCLUDING AN ELEMENT EXTENDING