US3570255A

US3570255A - Mine roof support

Info

Publication number: US3570255A
Application number: US735698A
Authority: US
Inventors: Peter Shuttleworth
Original assignee: Mastabar Mining Equipment Co Ltd
Current assignee: Mastabar Mining Equipment Co Ltd
Priority date: 1968-06-10
Filing date: 1968-06-10
Publication date: 1971-03-16
Anticipated expiration: 1988-03-16

Abstract

AN ADVANCING MINE ROOF SUPPORT HAVING A SOLID CANOPY WHICH IS SUPPORTED ABOVE A BASE FRAME BY A PLURALITY OF HYDRAULIC PROPS, MOUNTED AT THE FRONT AND REAR OF THE BASE FRAME, WHICH ARE EXTENDABLE TO RAISE AND LOWER THE CANOPY. THE REAR OF THE SUPPORT IS ENCLOSED BY AN UPSTANDING SHIELD OF SRAP-AROUND CONFIGURATION HAVING TWO SIDE WALLS AND A SLOPING REAR WALL, THE SHIELD AND BASE FRAME TOGETHER FORMING A SHOE ASSEMBLY AND, WITH THE CANOPY, SERVE TO PROTECT THE INTERIOR OF THE SUPPORT FROM ROOF FALLS AND THE FLUSHING OF THE CAVED WASTE. FURTHER PROTECTION IS AFFORDED BY A FLAP, HINGED TO THE REAR OF THE CANOPY AND ARRANGED TO REST AGAINST THE INCLINED REAR WALL OF THE SHIELD. THE FLAP MAY INCLUDE SIDE WALL PORTIONS TO OVERLIE THE SIDES OF THE SHIELD AND PREVENTS WASTE FROM ENTERING BETWEEN THE CANOPY AND SHIELD WHEN THE

FORMER IS RAISED. THE BASE FRAME IS OF SLEDGE LIKE CONSTRUCTION, HAVING TWO SIDES MEMBERS OR RUNNERS, LINKED BY ONE OR MORE LATERAL CROSS BEAMS. HINGED OR LOST MOTION CONNECTIONS ARE PROVIDED BETWEEN THE ENDS OF THE PROPS AND THE CANOPY AND BASE FRAME AND BETWEEN THE FLAP AND THE CANOPY AND HYDRAULIC RAM MEANS IS CONVENIENTLY MOUNTED ON THE BASE FRAME FOR CONNECTING TO A CONVEYOR FRAMEWORK OR THE LIKE, TO EXTEND OR RETRACT THE SUPPORT RELATIVE TO THE FRAMEWORK AND FACE BEING WORKED.

Description

March 16, 1971 P. SHUTTLEWORTH 3,570,255

MINE ROOF SUPPORT Filed June 10, 1968 4 Sheets-Sheet 1 INVENTOR:

PETER SHUTTLEWORTH SLWla/w fiwmld M March 16, 1971 P. SH UTTLEWQRTH 3,570,255-

MINE ROOF SUPPORT Filed June 10, 1968 4 Sheets-Shegt 2 I I W L "A III INVENTOR:

PET ER SHUTTLEWORTH 4 Sheets-sheaf I5 INVENTOR:

PETER SHUTTLE WORTH P. SH UTTLEWORTH March 16, 1971 MINE ROOF SUPPORT Filed June 10, 1968 h xi! l l l l I l l l l l l lll F I l l l I I I l l m m m "mu" u n. n a mm m? g Q EE March 16, 1971 P. SHUTTLEWORTH 3,570,255

MINE ROOF SUPPORT Filed June 10, 1968 4 Sheets-Sheet 4 K v WA IN ENTOR.

' PETER SHUTTLE-WORTH BY 640w, S Av- Mid;

United States Patent 3,570,255 MINE ROOF SUPPORT Peter Shuttleworth, Hornsea, England, assignor to Mastabar Mining Equipment Company Limited, Hull, England Continuation-impart of application Ser. No. 632,755, Apr. 21, 1967. This application June 10, 1968, Ser. No. 735,698

Int. Cl. E21c 41/00; E21d 11/00, 23/20 U.S. Cl. 61-45 19 Claims ABSTRACT OF THE DISCLOSURE An advancing mine roof support having a solid canopy which is supported above a base frame by a plurality of hydraulic props, mounted at the front and rear of the base frame, which are extendable to raise and lower the canopy. The rear of the support is enclosed by an upstanding shield of wrap-around configuration having two side walls and a sloping rear wall, the shield and base frame together forming a shoe assembly and, with the canopy, serve to protect the interior of the support from roof falls and the flushing of the caved waste. Further protection is afforded by a flap, hinged to the rear of the canopy and arranged to rest against the inclined rear wall of the shield. The flap may include side wall portions to overlie the sides of the shield and prevents waste from entering between the canopy and shield when the former is raised. The base frame is of sledge like construction, having two side members or runners, linked by one or more lateral cross beams. Hinged or lost motion connections are provided between the ends of the props and the canopy and base frame and between the flap and the canopy and hydraulic ram means is conveniently mounted on the base frame for connecting to a conveyor framework or the like, to extend or retract the support relative to the framework and face being worked.

This application is a continuation-in-part of my prior application Ser. No. 632,755, which has been abandoned.

This invention concerns advancing mine roof supports, that is to say, mine roof supports which are capable of being advanced under power, usually hydraulic power, from a position which they occupy during and up to the time when a face cutting operation is completed, to a new position corresponding to the cutting of the next succeeding thickness of face.

It is a primary object of the invention to provide an improved base construction for advancing mine roof supports.

Modern rapid extraction from a mine face, especially in coal mining, necessitates the caving of the roof behind the extracted areas, and this in turn requires adequate protection for the operators, particularly from roof falls and from so-called flushing of the caved waste that is, from the tendency of the collapsed material in the caved areas to run forward down its own natural slope.

To this end it has been proposed to provide a shield at the rear of a mine roof support. It is a further object of the invention to provide additional protection to that provided by the shield.

According to the present invention an advancing mine roof support comprises forward and rearward hydraulic props mounted on a base with a canopy above and covering the area defined by the base and an upstanding shield of Wrap-around configuration having an inclined rear wall and side walls enclosing the sides of the base at the rearward part thereof, the shield forming with the base part of a shoe assembly and providing a mounting for the rear hydraulic props in which the base is formed 3,57%,255 Patented Mar. 16, 1971 from a pair of parallel spaced apart sledge-like runners which are rigidly joined together by bridge members at the front and rear of the support.

Preferably a flap is hinged to the rear underside of the canopy and is arranged to rest in sliding relation against the rear wall of the shield to cover any gap between the canopy and shield which results from the extension of the hydraulic props and the hinged connection conveniently permits a degree of sliding movement between the flap and the shield. In order to prevent the entry of debris from the sides, the flap is preferably of wraparound configuration and includes side portions which overlie the sides of the shield.

In operation a number of roof supports are positioned side-by-side with their front ends adjacent one side of a coal conveyor running parallel with the coal face. On the other side of the conveyor a face cutting machine travels along the coal face. In order to prevent roof fall over the conveyor, the canopy of each support preferably extends forwardly to cover the conveyor.

According to a particularly preferred feature the forward extension of the canopy exceeds the width of the conveyor by an amount substantially equal to the width of the coal face cutting machine. In this way the supports can be moved up immediately behind the face cutting machine as the latter travels along the coal face so that the freshly exposed roof can be supported immediately.

Since the extended portion of the canopy merely supports the roof above equipment and not personnel, it need not be solid but can comprise a cantilevered arm assembly of resilient material such as spring steel.

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

FIG. 1 is a perspective view of a mine roof support in which the base is formed from a pair of parallel spaced apart runners,

FIGS. 2 and 3 are side views of a coal face and illustrate how a roof support according to the invention can support the freshly exposed roof beyond the face conveyor,

FIG. 4 is a plan view from below of a cantilevered extension for the front end of the support canopy, and

FIG. 5 is a section on AA of FIG. 2.

FIG. 1 illustrates an embodiment of the invention in which the base of the roof support is formed from two similar sledge-

like runners

70, 72 which are arranged in a parallel spaced arrangement and are rigidly joined at the front by a bridging housing 76 and at the rear of the support by a bridge member 74. A shield 30 is secured across and around the rear of the two

runners

70, 72. Clamps 23 for securing two front hydraulic props 22 are carried by the housing 76.

A hydraulic ram 26 is secured between the two

runners

70, 72 at the rear of the support and the two runners serve to protect a relay bar 28 which extends from the ram 26, between the two runners and under the housing 76 to emerge at the front of the support for connection to a conveyor framework (see FIGS. 2 and 3). In operation, the conveyor is maintained both adjacent and parallel to the face being worked by extending the ram 26, and also serves as an abutment towards which the support may be drawn by retracting the ram, in each instance dependent upon extension or retraction of the props 22 and 24.

The support also includes a solid canopy 25 which is supported by the two front props 22 and by two props 24 mounted at the rear of the support. The canopy provides uninterrupted cover over the whole area defined by the base of the support. Together, therefore,

the roof canopy and the rear shield 30, provide full protection against roof falls and also against flushing of waste material into the rear of the base frame. Thus, when a plurality of roof supports as proposed by the invention are arranged, as in practice, in side-by-side relation, they provide a continuous tunnel through which an operator can pass in safety. The canopy and rear shield also protect the ram 26 and relay bar 28 against damage when they are used for advancing the conveyor or the support, and provide a safe housing for hydraulic pipes and hydraulic controls. Still further, when the waste is caved, should the rear of the support become buried, its shape permits easy extraction, whilst at the same time, burying of the support is itself useful in preventing the rear of the base frame from lifting excessively over what little debris may have found its way between and under adjacent supports.

The sides of the rear shoe prevent flushed waste entering around the rear props, particularly when a support is not in line with the others as for example, when advancing them after the conveyor has been pushed over to a newly cut coal face. The supports are then stepped, because they cannot all be released from the roof and advanced as a whole, but must be operated in sequence. Often when a roof support is moved the roof behind the waste side immediatdely caves and can bury the rear of the support and flush around the side.

The space between the front bridging housing 76 and the shield 30 may be covered when the support is in use, by a crawl guard shown in dotted outline and identified by the reference numeral 78.

It will be appreciated that, should it become necessary tho extend the props 22 and 24 significantly, a gap can occur between the top of the shield 30 and the underneath of the roof canopy 25 through which debris can fall and to prevent this, a flap 46 is hinged to the canopy 25 and arranged to rest in sliding relation on the shield 30. In this way, whatever gap may be created as a result of extension of the props the interior of the tunnel is always guarded by the flap 46. In order to provide the flap 46 with a degree of upward or downward movement so that it will lie in contact with the rear of the upstanding shield 30 at all times, the flap 46 is preferably hinged to the rear end of the canopy 25 in slotted holes 48 formed in the canopy 25 or the sides of the flap 46 or both. In consequence the flap 46 is prevented from being forced from contact with the exterior of the rear of the upstanding shield 30.

In order to prevent the entry of debris from the sides, the flap 46 is of wraparound configuration and to this end is formed with side panels one of which is shown in dotted outline in FIG. 1 and is identified by the reference numeral 50. The side panels 50 are arranged to overlie the sides of the shield 30 and may be of integral construction with the flap 46 or formed separately and secured to the flap 46 for example by means of bolts.

By virtue of the inclination of the rear flap 46, the force due to the weight of any debris and roof fall on the rear flap can be considered to have a forward horizontal component in addition to a downward vertical component, which components respectively assist in urging the roof support in a forward direction and the canopy in a downward direction to assist in the retraction of the props.

It will be appreciated that the hydraulic props may occasionally have to be removed for replacement or overhaul when the roof support is in use. To facilitate their removal, particularly when they are in their collapsed state, the upper end of each hydraulic prop is located within a recess in the canopy which permits a degree of angular displacement of each prop relative to the canopy. To withdraw a prop it is then only necessary to free the lower end and swing the prop about its upper end, after which it can be lowered out of the recess and removed from the roof support.

To this end each runner is of generally U cross-section and the lower ends of the props 22, 24 fit between the two upright walls 78, (78, 80") of the U section. The lower ends of the front props 22 are normally prevented from moving backwards by pins (not shown) which are removably fitted in the

runners

70, 72. The lower ends of the two rear props 24 are prevented from moving forward by means of stop members 19 of open box construction for rigidity, which are bolted or pinned between the upright walls 78, 80 (78, 80") of the U- section of the two runners 7 0, 72.

As shown in FIGS. 2 and 3 the forward end of the canopy 25 extends beyond the front of the base so that the canopy can support the roof 102 above a conveyor arranged in front of the support. The length of the canopy extension 27 is such as to both overlie the conveyor and when the support is moved close up against the side of the conveyor, also the freshly exposed roof 106 immediately behind a face cutting machine (not shown) whose path of travel is parallel to the conveyor and on the side thereof remote from the roof support(s).

As shown in FIGS. 1 to 3 the overhang 27 may be a solid member formed integrally with or secured to the canopy 25.

When the roof canopy 25 is so extended, jamming of the front props 22 can occur on retraction, due to the great weight of unsupported canopy. To overcome this power retraction (not shown) may be applied to the rear props 24. Alternatively or in addition, restrictors 94 (shown in dotted outline) may be mounted on the front props 22. The restrictors per semay have any conventional construction and need not be described further.

As illustrated in FIGS. 4 and 5 the canopy overhang may alternatively compromise a cantilever, resilient armlike structure, comprising two multiple element spring steel leaf springs 84 joined at their forward ends to a load spreader plate 86 and secured at their rearward ends to an inclined mounting 88 within the canopy 25. The latter is cut away to receive the rearward ends of the two leaf springs 84 and the springs are secured to the mountings 88 by a quick release pin assembly 90. The resilience of the springs 84 causes the spreader plate 86 to be urged against the mine roof whilst accommodating any uneveness therein.

Although the load spreader 86 has been shown and described as a single plate member, this need not necessarily be the case. In fact it has been found in practice that two plates joined by a spring steel strap are more suitable than a single plate under certain circumstances. A two part spreader plate so formed, can accommodate much greater uneveness in the mine roof than a single plate member. Accordingly, where the expression spreader plate has been used in the specification it is to be understood that this expression includes both a single plate as illustrated in FIGS. 4 and 5 and two plates joined by a spring steel spreader.

The invention is of particular use in conjunction with coal face cutting machines having a width of out between 1 foot and 5 foot.

Although not shown in detail, a ring of rubber is sandwiched between the

clamps

23, 38 and the legs 22, 24 to permit movement of the latter within and relative to the clamps.

I claim:

1. An advancing mine roof support comprising in combination, a base frame including two laterally spaced apart generally parallel sledge-like runners engageable with ground surface of a mine, and front and rear bridge members located above the runners and rigidly interconnecting the two runners at the front and rear of the support respectively, at least two vertical hydraulic props mounted at the front of the base frame and secured to said front bridge member and at least two vertical hydraulic props mounted at the rear of the base frame, the base frame being open between said runners and the runners extending continuously between the hydraulic props at the front and rear of the frame, a canopy carried by the hydraulic props and covering the area defined by the base frame, and an upstanding shield of wrap around configuration secured across the rear of the base frame to said runners and having an inclined rear wall and two side walls enclosing the sides of the base frame at the rear end thereof, said shield forming a part of a shoe assembly and providing a mounting for the hydraulic props at the rear end of the base frame.

2. A mine roof support according to claim 1 further comprising,

a flap which is hingedly joined to the rear of the canopy and is arranged to rest in sliding relation against the shield to cover any gap between the canopy and shield which results from extension of the hydraulic props.

3. A mine roof support according to claim 2 wherein the flap is of wrap-around configuration and includes side portions which overlap the side walls of the shield.

4. A mine roof support according to claim 2 wherein the hinged connection between the flap and the canopy permits sliding movement of the flap relative to the shield.

5. A mine roof support according to claim 4 wherein the canopy is in part cut away on opposite sides to define two slots and two lugs are formed on opposite sides of the fiap, the two lugs engaging in the slots and forming said hinged connection.

6. A mine roof support according to claim 4 wherein opposite sides of the flap are in part cut away to define two slots and two lugs are formed on opposite sides of the canopy, the two lugs engaging in the slots to form said hinged connection.

7. A mine roof support according to claim 4 wherein the canopy and the flaps are both in part cut away on opposite sides to define two slots and two lugs engage in the slots and provide said hinged connection.

8. A mine roof support according to claim 1, further comprising, in combination a hydraulic ram, mounted centrally of the rear hydraulic props, and

mechanical force transmitting means secured to the ram for securing the ram to a face conveyor framework so that by extending the ram the roof support is maintained adjacent and parallel to a face being worked and by retracting the ram, the roof support is drawn towards the framework.

9. A mine roof support according to claim 1 wherein portions of the canopy are cut away to define recesses and the upper end of each hydraulic prop is located at least in part within one of these recesses thereby to permit a degree of angular displacement of the prop relative to the canopy.

10. A mine roof support according to claim 9 further comprising stop members located at the lower end of each hydraulic prop to prevent movement of the props relative to the base frame, said stop members being separately removable to permit angular displacement of each prop and to thereby allow each prop to be swung about its upper end so that it can be withdrawn from the support.

11. A mine roof support according to claim 1 further comprising a flat removable platform overlying the two parallel runners intermediate the front and rear ends of the support, the platforms of adjacent supports coopertaing to provide a substantially continuous fiat surface on which face workers can operate.

12. A mine roof support according to claim 1, in which the canopy constitutes an uninterrupted roof over at least the base area of the support.

13. A mine roof support according to claim 1 for use in conjunction with a coal face cutting machine and conveyor disposed between the support and the coal face in which the canopy extends forwardly beyond the front end of the support by an amount at least equal to the width of the coal conveyor.

14. A mine roof support according to claim 13 in which the canopy extends forwardly beyond the front end of the support by an amount equal to the sum of the width of the coal conveyor and the width of the cut made by the coal face cutting machine.

15. A mine roof support according to claim 13 further comprising power retraction means applied to the rear hydraulic props to assist in lowering the canopy.

16. A mine roof support according to claim 13 in which the forwardly extended portion of the canopy comprises a cantilevered arm formed at least in part from resiilent material.

17. A mine roof support according to claim 16 in which the cantilevered arm comprises two forwardly directed parallel leaf springs secured at one end to the foward end region of the canopy and a load speading plate secured to and bridging the remote ends of the two leaf springs.

18. A mine roof support according to claim 16 further including means including a quick release pin assembly securing said cantilevered arm to the remainder of the canopy whereby the cantilever arm is readily de tachable from the canopy.

19. A mine roof support according to claim 13 further comprising restrictor means fitted to the front hydraulic props.

References Cited UNITED STATES PATENTS 2,657,028 10/1953 Joy 61-45 3,483,705 12/ 1969 Roberts 61-45 3,342,034 9/1967 Andrews et al. 61-45 3,381,480 5/1968 Andrews 61-45 3,425,229 2/1969 Groetschel 61-45 3,324,664 6/1967 Allen 61-45 3,370,431 2/1968 Adcock et al. 61-45 FOREIGN PATENTS 982,024 1965 Great Britain 61-45 1,313,208 11/1962 France 61-45 1,426,731 12/1965 France 61-45 983,079 2/ 1965 Great Britain 61-45 JACOB SHAPIRO, Primary Examiner US. Cl. X.R.