US3832856A

US3832856A - Device for vertically positioning the props of a mine roof supporting frame

Info

Publication number: US3832856A
Application number: US00315238A
Authority: US
Inventors: S Sigott; A Zitz; H Sussenbeck
Original assignee: Alpine Montan AG
Current assignee: Alpine Montan AG
Priority date: 1971-12-14
Filing date: 1972-12-14
Publication date: 1974-09-03
Anticipated expiration: 1991-09-03
Also published as: GB1379417A; JPS4876702A; ES409544A1; PL73430B1; YU301072A; AT310114B; CS166831B2; DE2259271A1; HU165109B; FR2163542A1; JPS5315443B2; DE2259271B2; YU35180B; SU639472A3; FR2163542B1

Abstract

A device for vertically positioning the props of a mine roof supporting frame in which a cap is supported by a plurality of props against a floor frame, comprising two claws being disposed so as to be movable towards each other; a stationary abutment, the two claws being arranged both sides of the abutments; a post being disposed stationarily on the floor frame, the abutment being located on the post; a hydraulic cylinder-and-piston arrangement being adapted for locating a prop between the two claws, the piston of the hydraulic cylinder-and-piston arrangement being disposed between the two claws; and pressurerelief valve means for maintaining constant the positioning force and thereby limiting the positioning force so that when excessive forces occur due to ground movements the pressure relief valve means opens before the props are damaged, the valve means being disposed in the working chamber of the hydraulic cylinder-andpiston arrangement.

Description

United States Patent [191 Sigott et al.

[ 1 Sept. 3, 1974 DEVICE FOR VERTICALLY POSITIONING THE PROPS OF A MINE ROOF SUPPORTING FRAME [75] Inventors: Siegfried Sigott, Alfred Zitz;

Heinrich Sussenbeck, all of Zeltweg, Austria [73] Assignee: Oesterreichisch-Alpine Montangesellschaft, Vienna, Austria [22] Filed; Dec. 14, 1972 [21] Appl. No.: 315,238

[30] Foreign Application Priority Data Dec. 14, 1971 Austria 10739/71 [52] US. Cl. 61/45 D, 248/357 [51] Int. Cl E21d 15/44 [58] Field of Search 61/45 D; 248/357; 91/189; 299/31, 33

[56] References Cited UNITED STATES PATENTS 3,016,992 l/1962 Wilson 92/52 X 3,309,054 3/1967 Davis-Ratcliffe 248/357 X FOREIGN PATENTS OR APPLICATIONS 779,791 7/1957 Great Britain 248/357 Primary ExaminerDennis L. Taylor Attorney, Agent, or Firml-lolman & Stern [57] ABSTRACT A device for vertically positioning the props of a mine roof supporting frame in which a cap is supported by a plurality of props against a floor frame, comprising two claws being disposed so as to be movable towards each other; a stationary abutment, the two claws being arranged both sides of the abutments; a post being disposed stationarily on the floor frame, the abutment being located on the post; a hydraulic cylinder-andpiston arrangement being adapted for locating a prop between the two claws, the piston of the hydraulic cylinder-and-piston arrangement being disposed between the two claws; and pressure-relief valve means for maintaining constant the positioning force and thereby limiting the positioning force so that when excessive forces occur due to ground movements the pressure relief valve means opens before the props are damaged, the valve means being disposed in the working chamber of the hydraulic cylinder-and-piston arrangement.

10 Claims, 4 Drawing Figures PATENTEDSEP3 m4 sum 1. u; 2

FIG.

. PROPS OF A MINE ROOF SUPPORTING FRAME BACKGROUND OF THE INVENTION The present invention refers to a device for vertically positioning the props of a mine roof supporting frame in which the cap is supported by a plurality of props against a floor frame. Such known devices for vertically positioning the props are formed of resilient elements. Such resilient elements are suitable to avoid folding up of the mine roof supporting frame and to maintain the props in upright direction as long as these props are not subjected to laterally acting forces, such resilient elements are, however, unsuitable for exerting sufficiently strong positioning forces. Such elastic members are not suitable for maintaining the props in vertical direction relative to the mine floor when the props are subjected to laterally acting forces.

SUMMARY OF THE INVENTION The invention now aims at avoiding these drawbacks and is essentially characterized in that two claws are arranged at both sides of an abutment stationarily arranged relative to the floor frame, in that these claws are arranged for being pressed together by a hydraulic cylinder and in that the prop is located between these claws, noting that to the working chamber of the hydraulic cylinder a pressure relief valve is connected for limiting the positioning force. In this manner the prop can be subjected to a considerable positioning force which may surpass even laterally acting forces. In view of the fact that the seam to be exploited is not always in a horizontal position, the position of props arranged vertically to the mine floor can substantially deviate from the perpendicular position, and it is just in this case that considerable laterally acting forces may occur, which, however, may be overcome by a positioning device according to the invention. When using a hydraulic pressure relief valve, the positioning force can be kept constant and by thus limiting the positioning force any risk of breakage can also be avoided. By providing between the claws a stationary abutment, the normal position of the prop relative to the mine floor is determined by limiting the positioning movement. Props assuming an oblique position are thus drawn in direction to the stationary abutment and therewith into normal position. Only when both claws are engaging the stationary abutment, the prop assumes a normal position in which the claws surround the prop without play or with little play. The positioning force exerted on one prop is effective also on the other props because these props are coupled together by means of the floor frame and the cap. In a usual arrangement, in which two props are arranged side by side and two such pairs of props are arranged, seen in direction of the cap, one after the other, the positioning means is conveniently arranged for acting on the props located side by side.

According to a preferred embodiment of the invention, the claws are acting on the prop and, respectively, the props at a level corresponding to at least one third of the length of the prop or props. In this manner, the lever arm on which the positioning force is acting is relatively long so that relatively considerable positioning forces can be exerted. According to an advantageous embodiment, the claws and, conveniently, also the abutment are arranged on a post surrounding the prop.

In a usual construction, according to which two props are arranged side by side, the claws are, conveniently, dual-acting and arranged for surroundingly grasping with both of their arms the props arranged side by side, noting that the hydraulic cylinder is acting upon the claws at a location between the props and that the abutment is arranged between both props.

BRIEF DESCRIPTION OF THE DRAWINGS The invention is further illustrated with reference to the drawing in which a device according to the invention is schematically shown.

FIG. 1 shows a side elevation of a mine roof supporting frame equipped with a positioning device for vertically arranging the props relative to the mine floor. FIG. 2 shows in a greater scale the positioning device in a perspective view. FIGS. 3 and 4 show the arrangement of the claws, noting that FIG. 3 represents a top plan view and FIG. 4 represents a section along line IV-IV of FIG. 3.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Cap 1 of the mine roof supporting frame is supported against the floor frame 6 by means of four

props

2, 3 and 4, 5. The

props

2, 3, 4 and 5 are pivotally connected to floor frame 6 and cap 1.

Two double-

arm claws

8 and 9 are slidingly guided within guides 10 and 11 arranged on a post 7. The

claws

8 and 9 are grasping the

props

2 and 3 in surrounding relation at the area of their rounded recesses 12. An abutment I3 is stationarily arranged on the post 7. The abutment 13 has an opening 14 through which two

tongues

15 and 16 are inserted. Claw 8 is welded to the

tongues

15 and 16 and a hydraulic cylinder 17 is connected to these

tongues

15 and 16 and the claw 8. The piston 18 of the hydraulic cylinder 17 has a piston rod 19 which is connected by means of a bolt 20 to claw 9. According to the embodiment shown in FIG. 4 a portion of the

tongues

15 and 16 is forming the body of the hydraulic cylinder 17 and to this body and the

tongues

15 and 16 are welded with their portions 15, 15'. Bolt 20 is introduced into elongated slots 21 of

tongues

15 and 16.

When introducing hydraulic fluid into the working chamber 22 of cylinder 17, claw 9 is drawn by piston rod 19 and bolt 20 in direction to claw 8, both parts (arms) of which are welded to cylinder 17. As soon as one of the claws is engaging with its engaging surface 23 the stationary abutment 13, the other one of the claws, i.e., claw 8 or claw 9, is drawing both

props

2 and 3 in direction to abutment 13 and thus into nonnal position in which finally also the engaging surface 23 of the other claw is engaging the stationary abutment 13. In this position,

props

2 and 3 assume a vertical position, and, in view of props 4 and 5 being coupled to cap 1 and floor frame 6, also props 4 and 5 were brought in vertical position. In this position the rounded recesses 12 of

claws

8 and 9 are engaging

props

2 and 3 without any play or with little play.

A pressure relief valve 24 is connected to working chamber 22 for limiting the positioning force and, respectively, maintaining constant the full positioning force attained. If the props are pressed in oblique position by eventually occuring ground movements, the claws may yield until the constant positioning force is no more exceeded.

Post 7 is, as shown in the drawing, of such a height that the

claws

8 and 9, which are arranged on top of the post, engage the props at a level corresponding to at least one third of their length.

The lower tongue 16 is laterally guided between guiding ledges. Tongues and 16 are secured against movement in vertical direction by the opening 14 provided within abutment 13. In total, the claws are, therefore secured against movement in all lateral directions as well as in vertical direction.

We claim:

1. A device for vertically positioning the props of a mine roof supporting frame in which a cap is supported by a plurality of props against a floor frame, said device comprising:

two claws being disposed so as to be movable towards each other;

a stationary abutment, said two claws being arranged on both sides of said abutment;

a post being disposed stationarily on the floor frame,

said abutment being located on said post;

a hydraulic cylinder-and-piston arrangement being adapted for locating a prop between said two claws, the piston of said hydraulic cylinder-andpiston arrangement being disposed between said two claws; and

pressure relief valve means for maintaining constant the positioning force and thereby limiting the positioning force so that when excess forces occur due to ground movement said pressure relief valve means opens before the props are damaged, said valve means being disposed in the working chamber of said hydraulic cylinder-and-piston arrangement.

2. A device as claimed in claim 1, wherein said two claws are engaging the prop at a level corresponding to at least one third of the length of the prop.

3. A device as claimed in claim 2, wherein said two claws are engaging said stationary abutment when assuming the position in which they surround the prop without play or with little play.

4. A device as claimed in claim 2, wherein said two claws and, conveniently, also said abutment are arranged on said post surrounding the prop.

5. A device as claimed in claim 2, wherein said claws are twin-arm claws and surroundingly engage the prop arranged side by side, said hydraulic cylinder-andpiston arrangement acting on said two claws between the prop and wherein said abutment is arranged between the prop.

6. A device as claimed in claim 2, further including said hydraulic cylinder-and-piston arrangement and two tongues, which are disposed adjacent to opposite sides of said two claws being rigidly connected to one of said two claws and the other one of said two claws being guided by means of said two tongues and connected with a piston rod of said hydraulic cylinder-andpiston arrangement.

7. A device as claimed in claim 6, wherein said stationary abutment has an opening through which said tongues are inserted.

8. A device as claimed in claim 2, wherein said post is provided with guides laterally engaging and guiding the lower one of said two tongues, said two claws being adapted for sliding movement on said guides.

9. A device as claimed in claim 2, wherein said two claws have an arcuate engaging surface for engaging the prop also laterally.

10. A device as claimed in claim 2, wherein said two claws are arranged at the pair of props being most remotely located from the cutting face.

Claims

1. A device for vertically positioning the props of a mine roof supporting frame in which a cap is supported by a plurality of props against a floor frame, said device comprising: two claws being disposed so as to be movable towards each other; a stationary abutment, said two claws being arranged on both sides of said abutment; a post being disposed stationarily on the floor frame, said abutment being located on said post; a hydraulic cylinder-and-piston arrangement being adapted for locating a prop between said two claws, the piston of said hydraulic cylinder-and-piston arrangement being disposed between said two claws; and pressure relief valve means for maintaining constant the positioning force and thereby limiting the positioning force so that when excess forces occur due to ground movement said pressure relief valve means opens before the props are damaged, said valve means being disposed in the working chamber of said hydraulic cylinder-and-piston arrangement.

5. A device as claimed in claim 2, wherein said claws are twin-arm claws and surroundingly engage the prop arranged side by side, said hydraulic cylinder-and-piston arrangement acting on said two claws between the prop and wherein said abutment is arranged between the prop.

6. A device as claimed in claim 2, further including said hydraulic cylinder-and-piston arrangement and two tongues, which are disposed adjacent to opposite sides of said two claws being rigidly connected to one of said two claws and the other one of said two claws being guided by means of said two tongues and connected with a piston rod of said hydraulic cylinder-and-piston arrangement.