US3925995A

US3925995A - Roof support frames for mining

Info

Publication number: US3925995A
Application number: US496687A
Authority: US
Inventors: Guenter Harmsma; Harry Rosenberg; Johannes Laabs; Kunibert Becker
Original assignee: Gewerkschaft Eisenhutte Westfalia GmbH
Current assignee: Gewerkschaft Eisenhutte Westfalia GmbH
Priority date: 1974-08-12
Filing date: 1974-08-12
Publication date: 1975-12-16
Anticipated expiration: 1992-12-16

Abstract

A roof support frame has a roof bar which is supported on first props connected to a base. A second prop depends from the roof bar and is retractable to enable it to be set on one side or other of the conveyor.

Description

United States Patent Harmsma et a1.

[ Dec. 16, 1975 ROOF SUPPORT FRAMES FOR MINING Inventors: Guenter Harmsma,

Bergkamen-Overberge; Harry Rosenberg, Leudinghausen; Johannes Laabs, Oberaden; Kunibert Becker, Werl, all of Germany Gewerkschaft Eisenhutte Westfalia, Westfalia, Germany Filed: Aug. 12, 1974 Appl. No.: 496,687

Assignee:

US. Cl. 61/45 D; 248/357 Int. Cl. E21D 15/44 Field of Search 61/45 D; 299/31, 33;

Primary Examirier-Dennis L. Taylor Attorney, Agent, or FirmSughrue, Rothwell, Mion, Zinn & Macpeak 5 7 ABSTRACT A roof support frame has a roof bar which is supported on first props connected to a base. A second prop depends from the roof bar and is retractable to enable it to be set on one side or other of the conveyor.

6 Claims, 10 Drawing Figures US. Patent Dec. 16,1975 Sheet2of4 3,925,995

mw mm @m I l I I IL ROOF SUPPORT FRAMES FOR MINING BACKGROUND OF INVENTION The invention relates to a support frame. There is a known and widely used system in which working breast or panel.

One object of the invention is to enable a support frame or the like, capable of being fed forward over the floor of the working, to be constructed in such a way that theroof can be supported in the working area particularly effectively, especially if the mining machines used penetrate the face to considerable depths, e.g., .to more than 1 meter. A further object of the invention is to provide an advancing device which is of comparatively moderate overall length but which will A support frames or other moving supporting elements nevertheless advance the frame by a distance comparable with the cutting depth. These and other objects will appear in greater detail from consideration of a specific embodiment of the invention which will now be described by way of example and with reference to the accompanying drawings, wherein each of FIGS. 1 to 3 is a side view of a roof support frame at a respective stage of advance, and each of FIGS. 40 to 4g is a plan view of a double-stroke advancing device for use with the support frame shown in FIGS. 1 to 3.

Referring to FIGS. 1 to 3, a longwall mine working includes a mineral face 11, a floor and a roof 19. A scraper chain conveyor 10 extends alongside the face and conveys to the end of the working mineral which is removed fromthe face by a shearing machine 12. The shearing machine has two cutting drums 13 which are adjustable in height and have an axial length of about 1500 mm. for example. One of the cutting drums removes the upper part of the seam while the other removes the lower part of the seam. Since the drums are of a substantial length, the machine is unbalanced and is therefore provided with a lateral extension 14 which bears against the floor on the face side of the conveyor rearwardly of the lower drum.

The roof of the working is supported by a series of support units or frames, only one of which is shown in FIGS. 1 to 3, but which is identical to the others.

The support frame has four hydraulic props l6 situated at the comers of a square and only two of which are shown in the side view. The feet of the props 16 rest on a floor bar 17 or are interconnected by some other device bearing against the floor. The upper ends of the props l6 bear a roof bar 18 which supports the roof 19 on the goaf side of the conveyor. The props are flexibly connected to the roof bar and floor bars. The roof bar 18 forms the main part of the superstructure of the support frame and is connected by a joint 20 with a further roof bar 21 which supports the roof in the working and conveying zones. At least one hydraulic prop 22 is suspended from the roof bar 21 by means of a ball-and-socket joint 23, and includes a number of telescope sections. The foot of the prop 22 is fitted with a base plate 24 by means of a ball joint. The hydraulic prop 22 is so constructed, in the known manner, that it can be retracted by subjecting its annular chambers to hydraulic fluid. Because the prop is suspended from the roof bar 21, the foot 24 of the prop is raised from the floor 15 during retraction, as shown by the dot-anddash line at 22 in FIG. 2.

The advancing device for shifting the support frame consists of a hydraulic advancing ram 25 having a cylinder articulated at 26 to an attachment 27 which is connected to a T-rail 28 secured to the goaf side of the conveyor. The piston rod 29 of the ram has a bifurcated end 30 which is articulated to a connecting bracket 31. at the rear end of the floor bar and projecting to the goaf side thereof. The rear prop 16 of the support frame and the advancing ram are protected by a shield 32.

The support frame is depicted in FIG. 1 prior to the passage of the shearing machine 12. The roof bar 21 is in a rearward position and the prop 22 is fully extended. As soon as the said machine has passed the support frame the advancing prop 22 is raised into the position 22 shown in FIG. 2 and the piston rod 29, retracted into its cylinder so that the support frame is shifted towards the work face 11 with the advancing prop depending from the roof bar 21. The prop 22 is thus brought into a position on the face side of the conveyor 10. The prop 22 is then extended to engage its base plate 24 with the floor and hold the roof bar 21 against the roof in the zone of the working area.

To advance the conveyor 10, the prop 22 is once again retracted to raise its base plate 24 from the floor and the ram 25 is actuated to extend its piston rod. The conveyor 10 is thus pushed under the prop 22 andagainst the work face, as shown in FIG. 3. The prop 22 is then once again extended and set, this time on the goaf side of the conveyor 10. Needless to say, during the shifting of the conveyor 10 the props 16 of the support frame are set between the roof and the floor and form the reaction for the shifting process.

A lever arm 33 projects from the rearward end of the roof bar 21 and has pivoted to it at 34 a cylinder 35. The piston rod 36 of the cylinder rests against the lower side of the roof bar 18. By extending the cylinder 35, the roof bar 21 is swung upwards towards the roof 19. During the shifting of the conveyor 10, therefore, the roof bar 21 is held firmly against the roof, even though the prop 22 has been lifted off the floor. It is also possible for the roof bar 21, during the shifting of the sup-- port frame, to be kept in contact with the roof by pressurising the cylinder 35. I

The support frame can be fitted with a number of props 22, (e.g., with two such props in succession to each other, as viewed in the work face direction) the props being suspended from one common roof bar 21' or from two adjacent roof bars.A number of cylinders.

35 or other pivoting devices for pivoting the roof bar 21 upwards can likewise be provided. Needless to say, the stroke of the cylinder 25 must be made equal to the depth of cut of the ripping machine 12, in order to enable the support frame and the conveyor to be shifted by a distance corresponding to the depth of cut.- As shown in FIGS. 1 and 3, these conditions are ful-- filled by a shifting cylinder which is extremely longwhen extended and which, on the goaf side, extends as;

far as the stowage compartment.

The advancing device shown in FIGS. 1 to 3 is of a simplified kind to facilitate understanding of the operation of the frame as a whole. I

In order to reduce the over-all length of the advancing device and nevertheless to obtain a sufficient advance stroke, it is preferred in accordance with the invention to use a double stroke advancing device of the construction shown in FIGS. 4a to 4g.

In FIGS. 4a to 4g the support frame A (from which the prop 22 has been omitted) is shown in the various phases of the shifting movement, its hydraulic props 16 being interconnected by floor bars 17 comprising leaftype springs. Between the props 16 is a double-acting shifting ram 25 articulated at 26 to the coal face conveyor 10. The stroke of the shifting ram 25 is approximately equal to half the cutting depth of the mining machine.

Parallel guide bars

50 and 51, which consist of flat bars and along which is guided a sliding block 52 constructed as a slide, are affixed to the two floor bars 17 of the support frame. The floor bars are fitted at their rearward ends with brackets 53 which form prolongations of the guide bars 50 and 51 and which are provided with stop lugs 54. The guide bars 50 and 51 are provided with

recesses

55 and 56 respectively in the vicinity of the brackets 53 and also forwardly thereof. In addition, stops 57 are situated at the front ends of the guide bars. The piston rod 29 of the shifting ram 25 is connected via a pin joint 58 with a pressure-and tension-proof, approximately box-shaped coupling element 59 which bears apivot shaft 60 on which are pivotably mounted two claws 61 and 6 1-. To the sliding block 52 are affixed two bolts 62 and 62' of a link guide, which pass through slots 63 of the claws. The link guide is so constructed that on the retraction and extension of the shifting ram 25 the claws are moved from a position in which'they have been pivoted forwards (FIG. 4b) into a position in which they have been pivoted backwards (FIG.- 4c).

FIG. 4a shows the support frame A in the initial position, in which it props 16 have been set. In order to shift the conveyor 10, the shifting ram 25 is extended as shown in FIG. 4b, the support frame providing the reaction for the shifting ram. In this process the piston rod 29 rests via the coupling element 59 and the slide block 52, and by means of the stops 24 indicated in FIG. 412, against the lugs 54 of the brackets 53. It may be seen that when the shifting ram 25 is subjected to pressure, the slide block 52 is first of all moved by the extending piston rod 29 towards the right, as viewed in the drawings, until the stops 64 of the slide block encounter the lugs 54. In this adjusting movement the claws 61 and 61' are pivoted from the piston shown in FIG. 4a into that shown in FIG. 4b.

In FIG. 4b the conveyor has been shifted by a distance corresponding to half the cutting depth of the shearing machine. In order to shift the conveyor by a further partial stroke to bring it into engagement with the new face, the shifting ram is retracted in accordance with FIG. 40. In this process the slide block 52 is drawn forwards in the direction shown by the arrow S, by the retracting piston rod 26, and the claws 61 and 61' are pivoted, via the coupling element 59 and the link guide 62, 63, into the position shown in FIG. 40. When the shifting ram 25 has been fully retracted, the

claws

61 and 61 are situated in the vicinity of the recesses 56 of the guide bars 51. If the shifting ram 25 is once again extended, then the

claws

61 and 61 are first of all spread outwards, at the beginning of the extending movement of the piston rod, as shown in FIG. 4d, in such a way that the said claws come to rest by their contact surfaces 65 against stops 66, which are formed by the end faces of the guide bars in the vicinity of the recesses 56. The piston rod 29 of the shifting ram 25 now rests against the support frame, via the

pivot claws

61 and 61 and the

stops

65 and 66, so that on the further extension of the shifting ram the conveyor 10 is shifted by a further partial stroke. At the end of the shifting process the conveyor 10 has been shifted to a distance corresponding to the complete advance movement (FIG. 4d).

The support frame A is then drawn up into position, in two partial strokes. For this purpose the shifting ram 25 is retracted, in accordance with FIG. 4e. The slide block 52 is first of all drawn forwards until it encounters the front stop lug 57, the

claws

61 and 61 being at the same time pivoted inwards. The retracting piston rod 29 then causes the slide block 52, which is resting against the stops 57, to accompany its movement in the direction shown by the arrow S. When the piston rod has been fully retracted, the support frame A has been shifted by a distance corresponding to half the advance movement (FIG. 42).

In order to shift the support frame A by afurther partial stroke, the shifting ram 25 is once again extended. The piston rod 29 moves the slide block 52 back into the position shown in FIG. 4f in which process the claws 61 and 61', at the beginning of the outward movement of the piston rod, are pivoted from the position shown in FIG. 42 into that shown in FIG. 4f. To enable the claws to be pivoted in this manner, the guide bars 50 and 51 are provided with the recesses 56. If the shifting ram 25 is now once again extended when in the position shown in FIG. 4f, then the

claws

61 and 61 are spread outwards at the beginning of the retracting stroke of the piston rod, so that their contact surfaces 65 come to rest against stops 66 of the guide bars and formed by the front edges of the recesses 55 of the said guide bars. On further retraction of the piston rod 29, the support frame A is drawn up to the conveyor 10, via the pivot claws which have been spread outwards. The support frame A now once again occupies the basic position shown in FIG. 4a.

It can be seen that the slide block'52, in conjunction with the locking device consisting of the claws, forms an adjustable stop providing reaction for the shifting cylinder 25 and its piston rod 29, and that in this manner the conveyor 10 and the support frame A can each be shifted in two partial strokes, the action of locking the slide block 52 and the claws in position in relation to the support frame being carried out automatically on the retraction and extension of the piston rod 29.

What we claim is:

l. A longwall mining system comprising: a conveyor, a mining machine guided for movement along the conveyor, and a series of roof supports arranged alongside the conveyor; at least one roof support comprising a base, at least one first prop extending upwardly from the base, a roof bar means supported on said at least one first prop, at least one second prop depending from said roof bar means forwardly of said at least one first prop, said at least one second prop being retractable from a fioorengaging position into a position spaced from the floor by a distance at least equal to the height of the conveyor, means for advancing the roof support in order to displace the said at least one second prop from a position rearwardly of the conveyor to a position forwardly of the conveyor, said means including a fluid operated ram means having a stroke shorter than the advance step of the roof support, said ram means being coupled between the conveyor and a sliding block, the base defining a guideway for the sliding block, said guideway having associated therewith a first stop means for supporting the sliding block against the force of the ram means during an initial extension stroke thereof and second stop means for supporting the sliding block against the force of the ram means during a subsequent extension stroke thereof, said second stop means being located forwardly of the first stop means and being cooperable with a locking device adapted to be moved into an active position upon extension of the ram means during said subsequent extension stroke.

2. A longwall mining system comprising: a conveyor, a mining machine guided for movement along the conveyor, and a series of roof supports arranged alongside the conveyor; at least one roof support comprising a base, at least one first prop extending upwardly from the base, a roof bar means supported on said at least one first prop, at least one second prop depending from said roof bar means forwardly of said at least one first prop, said at least one second prop being retractable from a floor engaging position into a position spaced from the floor by a distance at least equal to the height of the conveyor, means for advancing the roof support in order to displace the said at least one second prop from a position rearwardly of the conveyor to a posi tion forwardly of the conveyor, said means including a fluid operated ram means having a stroke shorter than the advance step of the roof support, a sliding block guided for movement along said base, a locking device pivoted on said sliding block, said ram means being coupled at one end to the conveyor and at its other end to the locking device, extension of said ram causing said locking means to pivot into an active position, and a guideway for the sliding block, said guideway including rearward stop means for engagement with the sliding block and forward stop means for engagement with the locking device when said locking device has been pivoted into its active position.

3. Support frame in accordance with claim 2 characterised by the fact that the locking device consists of two pivot claws which spread outwards during extension of the ram.

4. Support frame in accordance with claim 3, characterized by the fact that the pivot claws are pivotable about a shaft coupled to the ram and movable in relation to the sliding block in the direction of the stroke of the ram and are guided in relation to the sliding block by means of link guides.

5. Support frame in accordance with claim 4, characterized by the fact that the locking device is adjustable from a position in which, in order to move the conveyor, it supports the ram in relation to the stayed support frame, to a position in which it couples the ram to the support frame in order to move the latter up into position.

6. Support frame in accordance with claim 5, characterized by the fact that the sliding block is guided on parallel guide bars of the support frame, the said bars being provided with recesses to enable the pivot claws to be pivoted through, and with stop faces as a means of supporting the pivot claws.

Claims

1. A longwall mining system comprising: a conveyor, a mining machine guided for movement along the conveyor, and a series of roof supports arranged alongside the conveyor; at least one roof support comprising a base, at least one first prop extending upwardly from the base, a roof bar means supported on said at least one first prop, at least one second prop depending from said roof bar means forwardly of said at least one first prop, said at least one second prop being retractable from a floor engaging position into a position spaced from the floor by a distance at least equal to the height of the conveyor, means for advancing the roof support in order to displace the said at least one second prop from a position rearwardly of the conveyor to a position forwardly of the conveyor, said means including a fluid operated ram means having a stroke shorter than the advance step of the roof support, said ram means being coupled between the conveyor and a sliding block, the base defining a guideway for the sliding block, said guideway having associated therewith a first stop means for supporting the sliding block against the force of the ram means during an initial extension stroke thereof and second stop means for supporting the sliding block against the force of the ram means during a subsequent extension stroke thereof, said second stop means being located forwardly of the first stop means and being cooperable with a locking device adapted to be moved into an active position upon extension Of the ram means during said subsequent extension stroke.

2. A longwall mining system comprising: a conveyor, a mining machine guided for movement along the conveyor, and a series of roof supports arranged alongside the conveyor; at least one roof support comprising a base, at least one first prop extending upwardly from the base, a roof bar means supported on said at least one first prop, at least one second prop depending from said roof bar means forwardly of said at least one first prop, said at least one second prop being retractable from a floor engaging position into a position spaced from the floor by a distance at least equal to the height of the conveyor, means for advancing the roof support in order to displace the said at least one second prop from a position rearwardly of the conveyor to a position forwardly of the conveyor, said means including a fluid operated ram means having a stroke shorter than the advance step of the roof support, a sliding block guided for movement along said base, a locking device pivoted on said sliding block, said ram means being coupled at one end to the conveyor and at its other end to the locking device, extension of said ram causing said locking means to pivot into an active position, and a guideway for the sliding block, said guideway including rearward stop means for engagement with the sliding block and forward stop means for engagement with the locking device when said locking device has been pivoted into its active position.