US3383865A

US3383865A - Mine roof supports

Info

Publication number: US3383865A
Application number: US511492A
Authority: US
Inventors: Ian B Wilson; Norman Eric
Original assignee: Mastabar Mining Equipment Co Ltd
Current assignee: Mastabar Mining Equipment Co Ltd
Priority date: 1965-12-03
Filing date: 1965-12-03
Publication date: 1968-05-21
Anticipated expiration: 1985-05-21

Description

y 1968 B. WILSON ETAL 3,383,865

MINE ROOF SUPPORTS Filed Dec. 5, 1965 5 Sheets-Sheet l INVENTORS: IAN B wusau Y Emc NORMAN A TTo RMErs l. B. WILSON ETAL 3,383,865

MINE ROOF SUPPORTS May 21, H

Filed Dec. 5, 1965 5 Sheets-Sheet 23 INVENTORsj IAN .8 WuJo/v ER: Alden/w y 21, 9 9. WILSON E1"AL 3,383,865

MINE ROOF SUPPORTS Filed Dec. 5, 1965 5 Sheets-Sheet 4 lNVENTORfiI IAN 8. wuso/v ma NOKMA a FIG. .1. Q Q

' Arro wg ys y 1968 B. WILSON ETAL 3,3

MINE ROOF SUPPORTS Filed Dec. 5, 1965 5 Sheets-Sheet 5 INVENTORS. IAN 5 Watson 5 RIC Nay/n4 PNEY United States Patent Office 3,383,865 Patented May 21, 1968 3,383,865 MINE ROGF SUPPORTS Ian B. Wilson, Kirkcaldy, Fife, Scotland, and Eric Norman, Hull, England, assignors to Mastabar Mining Equipment Company Limited, Hull, Yorkshire, England, a British company Filed Dec. 3, 1965, Ser. No. 511,492 12 Claims. (Cl. 61-45) ABSTRACT OF THE DISCLOSURE In a roof support and conveyor assembly for a mine, a plurality of roof support units each having at least one horizontal ram attached to the conveyor for advancing the latter upon extension and for drawing the units towards the conveyor to new positions upon retraction; and a plurality of cams fixed to the conveyor to respectively engage certain portions of the units to move the units into a position normal to the conveyor path upon retraction of the rams.

This invention concerns mine roof supports and relates more particularly to so-called powered roof supports.

Powered roof supports are generally used in selfadvancing arrangements wherein a support comprises a plurality of individual units each including a number of hydraulic pit props and each capable of being advanced independently of the others, so that while one group of units is employed to support the roof, another group may be advanced to a new position. The advancing movement of a unit is usually effected by a horizontal hydraulic ram incorporated in the unit and, in the majority of situations, the ram is secured at its free end to the supporting structure of an armoured conveyor which abuts the coal or mineral face being worked. However, difficulties can arise in such arrangements because the movement of the conveyor, as it is pushed by the ram against the face following a cutting operation, is not parallel to the face but is somewhat arcuate. Conditions therefore arise when the ram is not normal to the line of the conveyor or to the face line, and after a series of successive so-called snaking operations on the conveyor, the ram rod can become bent and may fail to retract.

According to the present invention, in an assembly including a powered roof support and a conveyor, the conveyor structure is provided with guide means by which the individual units of the support are caused, during retraction of the unit ram, to undergo both a lateral as well as an advancing movement and to finish such movement normal to the conveyor line.

The guide means may conveniently be cams arranged at spaced intervals along the conveyor structure.

The invention will be described further, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a diagrammatic plan view of the first section of a powered roof support and conveyor installation incorporating the invention;

FIG. 1a: is a diagrammatic plan view of the second section, which is continuous with FIG. 1, of a powered roof support and conveyor installation incorporating the invention;

(FIG. 2 is a diagrammatic plan view of part of another roof support and conveyor installation embodying the invention;

FIG. 3 is a similar view of another embodiment of the invention;

FIG. 4 is a detail in plan view, showing a modification of the embodiments of FIGS. 2 and 3, and

FIG. 5 is a view similar to that of FIG. 3 and illustrating another modification thereof.

*In FIG. 1 and FIG. la of the drawings an articulated conveyor generally designated 10 is shown as lying against a coal face 12, a cut 14 having been made in the face to produce a new face line 16 parallel to the original face 12. Adjoining the conveyor 10 are a plurality of roof support units 18 each comprising a base frame 20, a pair of front hydraulic props 22, a pair of rear hydraulic props 24 and a horizontal hydraulic ram 26 having the free or forward end of its ram rod 28 connected to the supporting structure of the conveyor 10. The installation as described thus far is conventional, and in operation, for the purpose of bringing the conveyor '10 against the new face line 16, with the props 22 and 24 of those roof support units which are located in the newly cut region, extended and in a roof-supporting condition, the rams 26 are operated to extend their rods 28 and push the conveyor 10 to its new position. The props 22 and 24- are then collapsed and the rams 26 operated to retract their rods 28, thus drawing the base frames 20 of the units 18 forward to the new conveyor line. However, as indicated earlier, the resulting conveyor movement is arcuate rather than linear, so that when the ram rods 28 are retracted to draw the base frames 20 up to their new positions, it is found that the centre lines of the base frames are not normal to the conveyor line or the face line and that successive snaking operations bend the ram rods 28 beyond a point when they are capable of retracting. The spacing between the units 18 also departs from the ideal of equal spacing.

In order to avoid these disadvantages, the invention provides a plurality of cam plates 30 mounted on the conveyor structure at intervals corresponding to the spacing between the roof support units 18. Each cam plate 30 has a base portion '32 by which it is secure-d to the conveyor structure and, opposite to the base portion, a relatively slender, generally V-shaped projection 34 with sides 36 which flare outwardly where they join the base portion. When the conveyor 10 is against the coal face, the projection 34 of each cam plate lies along a line normal to the conveyor and midway between an adjacent pair of units 18. When the conveyor "10 has been moved by the rams 26 from the face line 12 to the new face line 16, therefore, the cam plates 30 define both the intervals which it is desirable the units 18 shall have between them and also the direction normal to the new face line, While the spaced periphery of each cam plate serves to engage and guide one of the front props 22 of each unit 18 as its ram 26 is retracted to cause the unit to advance to its new position. By virtue of this peripheral shape, during its advancing movement, the unit 18 is also laterally deflected to ensure that it finishes in a position in which it is again normal to the conveyor 10. In this way, the rams 26 are protected from damage, the units 18 are maintained at a proper spacing and proper control of the supported roof is ensured.

In the embodiment of the invention illustrated in FIG. 2 of the drawings accompanying the complete specification, each roof support unit comprises three hydraulic props 40 mounted on a rear shoe 42 at the apices of an equilateral triangle with two of the props 40 situated on a line transverse to the length of the unit and the other prop 40 positioned forwardly of that line and on the centre line of the unit. A single front prop 44 is mounted on a centrally situated front shoe 46 which is of generally rectangular shape having chamfered front corners 48. On the conveyor structure are secured a plurality of spaced cam plates 50, of which two such plates are visible in FIG. 2, and the arrangement is such that a portion of each cam plate projects freely beyond the conveyor structure and has sides 52 which are inclined to converge in a direction away from the conveyor and thus to correspond to the inclination of the chamfered corners of the front shoe 46 of each support unit. The front shoe has laterally extending lugs 54 each of which carries a pivotally mounted collar 56 within which is secured the cylinder 58 of a hydraulic ram having its piston rod 60 attached to a cooperating one of the cam plates 50. Hydraulic control means (not shown) are provided to enable each of the

rams

58, 60 to be operated independently of the other, thus giving facility for the unit to be steered during an advancing movement.

The embodiment of the invention shown in FIG. 3 is similar to that of FIG. 2, except that the two steering and advancing rams, whilst being secured by their piston rods 62 as before to the co-operating cam plates on the conveyor structure, have their rear ends of their hydraulic cylinders 64 pivotally attached to the rear shoe 42 of the support unit, which for this purpose is provided at its front edge with a pair of forwardly extending and laterally spaced lugs 66. In all other respects, the construction and operation of this embodiment of the invention is comparable with that of FIG. 2.

FIG. 4 shows an alternative arrangement to that of FIGS. 2 and 3, in which the adjacent rams of adjacent roof support units are pivotally connected as by their piston rods 68 to the same cam plate 70, thus enabling a substantial reduction to be made in the total number of cam plates required.

FIG. 5 shows a modification of the embodiment of FIG. 2, in which the arms 72 are not simply attached to the rear shoe 42 but are actually mounted within that shoe and are pivotally connected by link bars 74 to the cam plates 50.

We claim:

1. In the combination of a self-advancing mine roof support and a conveyor, said roof support comprising a plurality of individual units each including a number of hydraulic pit props and each having generally horizontally disposed ram means for advancing said unit independently of the remaining units in the support so that while one group of units is employed to support the roof another group may be advanced to a new position, each unit having means interconnecting the associated pit props such that the pit props move together as a unit upon advancement by the ram means, the improvement wherein each ram means is fixed at a stationary point to the conveyor to advance the conveyor upon extension of the ram means and wherein the structure of the conveyor is provided with cam means for engaging cooperable portions of the individual units of the support, during the retraction of the ram means of the unit, to effect both a lateral and an advancing movement of the units to ultimately position of the units normal to the line of the conveyor.

2. The combination claimed in claim 1, wherein the cam means is a plurality of cams arranged at spaced intervals along the line of the conveyor.

3. The combination claimed in claim 1, wherein the advancing ram means of each unit is secured between the front of said unit and the conveyor.

4. The combination claimed in claim 1, wherein the advancing ram means of each unit is secured between the rear of said unit and the conveyor.

5. The combination claimed in claim wherein the advancing ram means of each unit comprises a pair of horizontal hydraulic rams arranged one at each side of said unit and independently operable for enabling the unit to be steered.

6. The combination claimed in claim 2, wherein each cam is a plate having a base portion by which it is secured to the conveyor structure and, opposite the base portion, inclined sides which are convergent in a direction away from said base portion.

7. The combination claimed in claim 2, wherein each cam is a generally rectangular plate secured along a rear edge region to the conveyor structure and formed with chamfered corners at the ends of its free edge.

8. The combination claimed in claim 3, wherein the cam means comprises a plurality of generally rectangular cam plates secured along their rear edge regions to the conveyor structure and having free front edges formed with charnfered corners at their ends, and wherein each ram means is secured to an associated one of said cam plates.

1". The combination claimed in claim 4, wherein the cam means comprises a plurality of generally rectangular cam plates secured along their rear edge regions to the conveyor structure and having free front edges formed with chamfered corners at their ends, and wherein each ram means is secured to an associated one of said cam plates.

10. The combination claimed in claim 6, wherein the inclined sides define a slender, generally V-shaped projection of which the regions of the sides adjoining the base portion flare outwardly to meet said base portion.

11. The combination claimed in claim 8, wherein adjacent rams of adjacent support units are secured to a common cam plate.

12. The combination claimed in claim 9, wherein adjacent rams of adjacent support units are secured to a common cam plate.

References Cited UNITED STATES PATENTS 3,192,721 7/1965 Gaskell 61- 15 FOREIGN PATENTS 4/1964 France.

German printed application 1,147,907, Klockner, May

JACOB SHAPIRO, Primary Examiner.