US3397543A

US3397543A - Mine roof support for progressive exploitation

Info

Publication number: US3397543A
Application number: US480400A
Authority: US
Inventors: Spies Klaus; Weirich Walter
Original assignee: Gewerkschaft Eisenhutte Westfalia GmbH
Current assignee: Gewerkschaft Eisenhutte Westfalia GmbH
Priority date: 1964-08-20
Filing date: 1965-08-17
Publication date: 1968-08-20
Anticipated expiration: 1985-08-20
Also published as: NL6510227A; DE1232908B; GB1123201A; BE667860A

Description

0, 1968 K. SPIES ETAL 3,397,543

MINE ROOF SUPPORT FOR PROGRESSIVE EXPLOITATION Filed Aug. 17, 1965 4 Sheets-Sheet 1 KLAUS SP\ES WALTER WE\RICH MINE ROOF SUPPORT FOR PROGRESSIVE EXPLOITATION Filed Aug. 17, 1965 4 Sheets-Sheet 2 Wyn/mas KLAUS SPIES WALTER WEIRICH Aug. 20, 1968 K. SPlES ETAL 3,397,543

MINE ROOF SUPPORT FOR PROGRESSIVE EXPLOITATION Filed Aug. 17, 1965 4 Sheets-Sheet 5 KLAUS SPIES WALTER WEIRICH ATTORNEY Aug. 20, 1968 K. SPIES ETAL MINE ROOF SUPPORT FOR PROGRESSIVE EXPLOITATION Filed Aug. 17, 1965 4 SheetsSheet 4 MUG M ra/r095 KLAUS SPiES WALTER WEIRICH United States Patent 3,397,543 MINE ROOF SUPPORT FOR PROGRESSIVE EXPLOITATION Klaus Spies, Dortmund-Wellinghofen, and Walter Weirich, Dortmund, Germany, assignors, by mesne assignments, to Gewerkschaft Eisenhutte Westfalia, Altlunen, Germany, a corporation of Germany Filed Aug. 17, 1965, Ser. No. 480,400 Claims priority, applicatigi; Ggelrmany, Aug. 20, 1964,

5 9 9 Claims. (Cl. 61-45) ABSTRACT OF THE DISCLOSURE The invention relates to support means for progressive mine exploitation and includes a plurality of upstanding spaced mineroof supporting units associated by longitudinally extending power-operated means positioned between each of the units. The sub-assembly of the units include ground-engaging glide plate support members as well as parallel upstanding spaced prop means extending above the glide plates and cover means on each of the prop means, The prop means also include power means for raising and lowering the props relative to the groundengaging glide members and spring means are arranged to interconnect the upstanding prop means and the groundengaging means adjacent to the glide plate support means with a feeler member being carried by the cover member of the intermediate prop to control the advance of the assembly and the mine exploitation.

This invention relates to a mine roof support for use in progressive mine exploitation wherein the support comprises parallel spacedly arranged pit props interconnected by means of guiding and advancing mechanisms.

Presently known hydraulic mine roof supports usually comprise two pit props which are interconnected by means of an advancing mechanism. The advancing mechanism comprises, in case of pit props with parallel advancement means the advancing cylinder proper and parallel guide means, and in case of a mine roof support of the type of swinging advancement it comprises mostly rigid steering means and an advancing cylinder which is arranged either diagonally in the mine roof support or is disposed between the steering mechanism adjacent the mine face and the conveyor mechanism.

Further, there are also known mine roof supports of the parallel advancing type which comprise three props which are tied one to another by means of an advancing cylinder having two piston rods as Well as by means of tie beam like connecting pieces. Furthermore, mine roof supports which also permit of a swinging type of advancement have been proposed wherein the leading mine roof support which comprises two props follows along in small swinging steps relative to the mine face while the principal mine roof support means also follows in swinging steps, but is spaced apart by longer distances.

Moreover, it is also known to secure together central props in units of three wherein the two external props are interconnected by means of a yoke on which rests an advancing cylinder for eifectuating the advancement of the middle prop.

Finally, there is also known a walking mine roof support wherein a group of three props are interconnected by means of a common advancing cylinder wherein the flanking or outside props are interconnected by means of a transversal rod and wherein the props move in a trailing rhythm.

The mine roof support including the above-mentioned 3,397,543 Patented Aug. 20, 1968 particular arrangement of the parallel advancement type has several disadvantages when used in sloping walls and thick strata.

It has also been found that the summation of the tolerances in the guidance and advancing mechanism as well as the front weight of the mine roof support, particularly that at the top caused by the projecting cap members, makes the mine roof support wander downhill in sloping strata where progressive exploitation is carried out. Since Wandering is not always equal for each of the supports, the occurrence of unsupported roof portions as well as mutual entanglement between the respective supports is consequently unavoidable. In practice,'it has been attempted to remedy this situation by untensioning the means controlling the three props of the support and thereafter readjusting the support by the alternative use of the advancing cylinder so as to bring the support into an increased advancing direction. This procedure, however, has the disadvantage that although the time of the advancing increases, the efiiciency of exploitation decreases. Furthermore, by untensioning the three props relative to the support, the condition of the mine roof may substantially deteriorate.

When sloping walls or thick strata are encountered relative to the center of gravity of the mine roof support particularly where only two props are utilized and these lie outside the sole plate, then it is possible that in case of unintentional untensioning of all four props of the support there is a danger of tipping as well as sliding which may seriously endanger the safety of the mining crew.

Although mine roof supports of the swinging advancement type (including the particular arrangements mentioned hereinabove) avoid the disadvantage of the absence of readjustment possibility in the event of wandering of the support, they nevertheless have another serious disadvantage in that their advancement follows in circular arcs whereby the advancement of the support means is made quite difficult or even impossible if during exploitation the heap to be exploited extends into the working area.

The above listed embodiments wherein three props are interconnected by means of a single advancing cylinder have also another disadvantage in that (at all times).

when the middle prop is advanced first, the two flanking props follow together simultaneously or vice versa..

Thus, under these circumstances the advancement is carried out necessarily in a rigid succession. Accordinglyit is not possible to provide another order of succession where this arrangement is used for an advancement at will of one of the outside props or the influencing of the supports to avoid downward wandering.

By means of the proposed solution thecombined areaadvancement of the middle prop the advancing cylinders of the two guiding mechanisms may be unequally opperated so that a steering of the entire mine roof support becomes possible.

The possibility of an independent advancement of eachindividual prop in the mine roof support further makes it possible to use one prop as a leading prop and in case of difficult conditions of exploitation follow the mining apparatus with this one particular prop in relatively small steps. In this improvement in the art, the leading prop has incorporated therein suitable means which provides a supporting force smaller than that of the two other props of the mine roof support. With this arrangement, it is possible that even in case of advancement being accomplished in small steps, the undesirable disturbance during the exploitation of the material may be held within tolerable limits.

In accordance with the invention, in order not to increase unnecessarily the crew for advancing the leading mine roof prop, there is provided a leading prop which, while maintaining a residual supporting force, continuously and automatically or intermittently automatically follows the mine face in individual steps upon actuation of a contact mechanism that interconnects the mine face with the leading mine roof prop. In case the stroke of the advancing cylinder between the leading prop and the other two principal props of the triple support is eX- hausted, the advancement of the principal support may be thereby actuated as well.

Accordingly, iti s the primary object of the invention to provide a mine roof support of the type which overcomes the disadvantages mentioned hereinabove.

Another object of the invention is to provide a mine roof support which is characterized by an arrangement of three props and two normally disposed guide and advancing mechanisms of which one guide mechanism and advancing mechanism each interconnect the middle prop with one outside prop.

Still another object of the invention is to provide a mine roof support which is arranged in such a manner that the individual pit props may be advanced independently of each other and the mine roof support may be steered by the alternate actuation of the advancing cylinders.

A further advantageous object of the invention is to provide a mine roof support comprising parts of a support system having two props, which is so arranged that it may be assembled merely by adding an additional new member namely, the middle dual stop shaft, to the conventional support having two props.

In materializing the inventive thought disclosed herein, any mine roof supports of desired construction may be used. Since the advantages of the proposed mine roof supports appear particularly in sloping strata, therefore, primarily those kinds of mine roof supports are considered which are springingly interconnected with guiding and advancing mechanisms and which provide for a vertical setting of the beams or props in the mine roof support after exploitation.

These and other objects and advantages will become apparent from the following description taken in conjunction with the accompanying drawings and which;

FIG. 1 is a front elevational view of three interconnected mine roof supports;

FIG. 2 is a side elevational view of one of the units shown in FIG. 1;

FIG. 3 is a top plan view of the unitary assembly shown in FIG. 1 with several of the caps removed for clarity;

FIG. 4 is a side elevational view of the cap of the leading prop in section showing a built-in contact mechanism with one part contacting mine wall face and FIG. 5 shows the same mechanism as FIG. 4, but in an extended position as the assembly advances.

Turning now to the drawings and more particularly that in FIG. 1, the mine roof support comprises three

conventional prop units

10, 11 and 12 arranged side by side with each of them being interconnected by means of guiding and advancing mechanisms 13 and 13'. The

individual prop units

10, 11 and 12 extend normal to a sole or

glide plates

14, 15 and 16 and are provided at their upper extremity with telescopable

hydraulic posts

17, 18 and 19. The posts are secured to the sole plates in a known manner by means of ball joints and are interjoined elastically by means of spring elements comprising leaf spring bundles 20 and 21 (FIG. 2). Each prop unit engages the mine roof (not shown) through the longitudinally extending

cap cover members

22, 23 and 24.

The

individual prop units

10, 11 and 12 are interdigitated by means of single or double

armed stub members

25 and 26 with the guiding and advancing mechanisms 13 and 13.

In the patent application of Weirich et al., Ser. No. 429,779, filed Feb. 2, 1965, which is also assigned to the assignee of this invention, there is disclosed in greater detail how the ofistanding double armed stub members carried by the guiding and advancing mechanisms are associated with each of the props shown therein. Thus, it appears to suffice to point out herein only that the U- shaped brackets carried by the guiding and advancing mechanisms hereof are removably secured to the props by the pivotal operator means 27 which carries a shaft (not shown).

The guiding'and advancing mechanisms 13 and 13 are built in such a manner that they are attachable to the support means or adapted to operate the same even when turned Thus, it is apparent that it is possible to advance at will first either the left or the right pit prop, i.e., 10 or 12 while it is connected to a respective guiding mechanism 13 or 13.

Moreover, by means of a corresponding arrangement of the guiding and advancing mechanisms and through the required actuation of the double action hydraulic cylinders of the advancing mechanism, the individual prop units may be advanced in any desired order of succession. Further, each pit prop unit may be used at the desire of the workman as a leading unit. The steerability of the mine roof support is achieved by the alternate actuation of the two cylinders of the advancing mechanism. In detail the steering is carried out in the following manher:

The inequality in the elevation of the apparatus which is brought about by the lowering of the previously advanced middle prop is first taken up by the

spring elements

20 and 21, and after the settling of the middle prop 11 and the forward motion process of the two flanking props, the

spring elements

20 and 21 move back into their normal position so that the two flanking prop units may also swing in the direction of the middle pit prop unit. This guiding motion may be carried out during the advancement process without additional manipulation. The same effect can also be achieved if the two flanking pit prop units are advanced first.

In the event one of the pit prop units of the triple support means is used as a leading prop unit, there are two possibilities for advancing this leading prop unit. First, that particular unit may be made to continuously follow the mine face during which time the cylinders, which are positioned outboard thereof and intermediate the adjacent prop units of the triple support means, are constantly provided with pressure and the leading prop unit is advanced while the pressure necessary to support the cap cover 24 is decreased sufliciently to permit the same to slide along the roof of the mine.

In the embodiment of the invention illustrated in FIGS. 4 and 5 there is shown a portion of the leading prop and longitudinal cap means beneath which is arranged a cylinder 35 and within which is slidably arranged a rod 36. The rod 36 includes an abutment 37 at its rearward portion which provides a sliding support for a spring 38 positioned in the chamber formed by the rear wall of the cylinder and the abutment 37 and at its front end includes a feeler member 39 adapted to engage the mine wall 40.

The abutment 37 includes a depending nose element 41 which is arranged to project through an elongated slot provided in the bottom of the cylinder and together with the feeler performs a function which will be best understood from perusing the description of operation.

Operation The feeler 39 is constantly urged against the mine face by means of the spring 38 disposed in the chamber of the slotted tube 35. This condition takes place particularly when the prop is in its settled position, i.e., not in complete weight-bearing contact with the roof of the mine wall. Y

As viewed in FIG. 4, for example, the feeler mechanism carried by the leading prop is in engagement with the mine wall 40. Accordingly, considering FIG. 4 further, when coal is exploited, the mine face is displaced towards the right in the view in the drawing and during this time lever 42 is displaced into a substantially vertical neutral position. It will be apparent that under the influence of spring 38 the feeler 39 will maintain its contact with the mine face. In the event a sufficiently wide coal strip is exploited (see FIG. 5), the nose portion 41 of the abutment 37 causes the lever 42 to move toward the right as viewed in this figure whereupon it will engage contact 43. As soon as the circuit is closed, a signal is transmitted from a suitable power supply source (not shown) to the intermediately disposed or leading prop unit. As a consequence of this signal the telescopable hydraulically actuated spaced posts 1818 are untensioned so that they are freed of their contact with the roof. As soon as this happens and through transmission of another signal, reciprocable pistons (not shown), which are positioned within the guiding and advancing mechanisms 13 and 13', are actuated causing advancement of the leading prop toward the mine wall. When this prop has attained a predetermined position adjacent to the wall and the opposite face of the pistons are brought into contact with the other end of the cylinder cover, another switch is actuated thus causing the telescopable hydraulically actuated spaced posts 18-18 to be raised again into supporting contact with the mine roof or ceiling.

It is also possible to work with a residual force of the spaced telescopable members applied against the roof. Accordingly, the pressure in the telescopable members may be reduced only to such a value that they may remain pushed against the ceiling, but only with such a limited amount of force that can be overcome by the advancing cylinders during the sliding movement of the spaced prop units.

In view of the foregoing, it will be apparent that through advancement of the intermediate prop, the feeler 39 is once again pushed back countering the force of spring 38 and at the same time the rod 32, which carries the feeler 39, displaces the switch lever 41 from its neutral vertically extending position into the other contact-making position at 44, thus efiectuating advancing movement through the current source of the two outboard prop units. These control slides or pushers arrive in a position in which the associated hydraulically actuated telescopable members of the prop units are untensioned so that they will free themselves from the ceiling of the mine. The decreasing pressure thus afiects the control slide for the guiding and advancing mechanisms 13 and 13 in that the opposite sides of the pistons referred to are activated, whereupon the cylinders are moved forward to advance the outboard prop units. When this motion is accomplished, a terminal switch provided within the cylinders of the guiding and advancing mechanisms 13 and 13' causes the caps of the hydraulically telescopable posts 17 and 19 to be set once again into contact against the ceiling thus terminating a working cycle.

Although only one embodiment of the invention has been depicted and described, it will be apparent that this embodiment is illustrative in nature and that a number of modifications in the apparatus and variations in its end use may be effected without departing from the spirit or scope of the invention as defined in the appended claims.

That which is claimed is:

1. A plurality of upstanding spaced mine roof supporting units interconnected by first power-operated means positioned therebetween and normal relative thereto comprising, a unitary structure including ground-engaging glide plate support means, parallel upstanding spaced prop means extending above said last named means, cover means on said prop means, said prop means including second power means for raising and lowering the prop means relative to said ground-engaging means and spring means interconnecting said upstanding prop means and said ground-engaging meansadjacent said glide plate support means, said first power means being adapted to advance one of said units relative to its associated companion units and thereafter any one of the other of the plurality of said units in sequence.

2. A plurality of at least three interconnected upstanding spaced mine roof supporting units associated by first power-operated means positioned between each of said units and normal relative thereto comprising, a unitary structure including ground-engaging glide plate support means, parallel upstanding spaced prop means extending above said last named means, cover means on said prop means, said prop means including second power means for raising and lowering the prop means relative to said ground-engaging means and spring means interconnecting said upstanding prop means and said ground-engaging means adjacent said glide plate support means.

3. A plurality of at least three interconnected upstanding spaced mine roof supporting units as claimed in claim 2, wherein the cover means of the intermediately disposed of said units includes control means adapted to engage the face of a mine wall.

4. A plurality of at least three upstanding spaced mine roof supporting units interdigitated by first power operated means positioned therebetween and normal relative thereto comprising, a unitary structure including ground-engaging glide plate support means, parallel upstanding spaced prop means extending above said last named means, cover means on said prop means, said prop means including second power means for raising and lowering the prop means relative to said ground-engaging means and spring means interconnecting said upstanding prop means and said ground-engaging means adjacent said glide plate support means, longitudinally extending means interconnecting the cover means of said spaced prop means and feeler means carried by at least one of said cover means for controlling the forward motion process of said units.

5. A plurality of at least three upstanding spaced mine roof supporting units as claimed in claim 4, wherein the feeler means includes an electro-hydraulic switch means and plural reciprocable means for tripping the same into on and off positions.

6. A plurality of at least three upstanding spaced mine roof supporting units as claimed in claim 5, wherein the electro-hydraulic means includes means adapted to introduce power from said means into either of said first power means and plural reciprocable means for tripping said switch means into on and off positions whereby any one of said units may be advanced relative to its companion interconnected units.

7. A plurality of at least three upstanding spaced mine roof supporting units as claimed in claim 6, wherein the electro-hydraulic means includes a cylindrical element positioned beneath the cover means, said cylindrical element being provided with an elongated slot means adapted to confine at least one of said reciprocable means to a predetermined path of travel.

8. A plurality of at least three upstanding spaced mine roof supporting units as claimed in claim 7, wherein the cylindrical element includes an extensible spring means adapted to urge the plural reciprocable means longitudinally relative to said cap means.

9. A plurality of at least three upstanding spaced mine roof supporting units as claimed in claim 4, wherein the feeler means is associated with the cover means of the intermediately disposed prop means.

(References on following page) 8 References Cited FOREIGN PATENTS UNITED STATES PATENTS 1,190,532 4/1959 France.

947,078 1/ 1964 Great Britain. 2,859,022 11/1958 Frye 6145.2 3,246,730 4/1966 Bolton et a1. 61-45.2 5 DAVID WILLIAMOWSKY, Primary in r- 3,309,880 3/1967 Potts et a1. 61-45 D. L. TAYLOR, Assistant Examiner.