GB1597973A - Boom-mounted impact-type rock breaker - Google Patents

Description

(54) BOOM-MOUNTED IlPACtTYPE ROCK BREAKER (71) We, GULLICK DOBSON LIMITED, a British Company, of Ince, Wigan, Lancashire, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed to be particularly described in and by the following statement: This invention relates to a machine having a tool, particularly an impact-type rock breaker, manipulable on a boom carried by a main frame, of the machine, and is especially applicable to mining machines.

Embodiments of the invention have particular but not exclusive application to traversable selective mining machines such as disclosed in our co-pending application no. 19478/77 (Serial No. 1597972). There, such a machine has a manipulable cutting tool mounted on an extensible boom which is carried by a main frame. The entire machine is translatable on a guide rail parallel to the face, but before cutting begins, the main frame is staked floor-to-floor by rams, so that the load is not carried by the translation mechanism. During cutting, the cutting tool will be moved away from the main frame on the boom and also positioned and directed for best cutting engagement by means of a multi-arm manipulable mount.Although the mineral being mined, for example gold, may occupy a relatively narrow seam, it is necessary to remove the surrounding hard rock to open up the face and allow subsequent advance of the machine and its associated guide means and conveyor, and provide access to the workings for the operatives.

The cutting tool is thus required to range over a relatively large area of the face, possibly removing a metre cube of rock between translation steps of the main frame, and may also be required to remove floor rock to form strike gulleys. When removing material at or near the deepest or furthest postions of the cut, high radial forces will be transmitted through the tool manipulating mount to the main frame boom Where the tool is an impacting type cutter, the loading at the tool point might be considerable, for example in excess of 10 tons, producing on the boom a correspondingly high torque loading. The boom, which is preferably rotatable as well as extensible must be able to tolerate such high torque, often beyond what is readily handled by conventional gear type drives.

An object of the present invention is to provide a machine capable of satisfactory operation under such conditions.

According to the present invention there is provided a machine comprising a main frame having a boom supporting a tool head in the form of an impact-type rock breaker, which boom is axially extensible from the main frame and is positively rotatable about its axis by means of a drive coupling from a linearly movable actuator.

A preferred drive mechanism comprises a longitudinally extensible drive arm such as a pressure-fluid-operated, preferably hydraulic, ram. Such a ram may act between a position fixed relative to the main frame, say a pivotal coupling thereto, and a drive coupling that is preferably slidable relative to the boom and rotatable therewith, to achieve a desired arc of boom rotation.

The slidable coupling between the longitudinally extensible member and the boom may be by way of a collar with a splined coupling to the boom. The arc of boom positive rotation may itself be rotated about the boom axis by altering the position at which the extensible drive member is coupled to the collar for example by securing the member via a removable pin to different ones of a plurality of holes spaced around flanging of the collar.

Extension of the boom may be by means of a fluid operated, preferably hydraulic ram, coaxial with and conveniently at least partly inside the rear of the boom.

At the front part of the boom, a pressurefluid, preferably hydraulic ram for manipulating the tool relative to the boom may also be located at least partly inside the end of the boom and pivotal relative thereto.

Such an arrangement of internal rams affords a compact machine construction, particularly useful in hard rock mining situations where space is limited.

An embodiment of the invention will now be described by way of example only and with reference to the accompanying drawings in which: Figure 1 is a diagrammatic view of a mining machine, Figure 2 is a sectional side view of a portion of the machine.

Figure 3 is a sectional end view of a part of the machine.

The machine shown in Figure 1 is described in greater detail in our co-pending application no. 19478/77 (Serial No. 1597972). Briefly, a mine face conveyor 10 comprises end-to-end articulated pans 11 with a relatively rearward mining machine guide rail 12 overlying the pans, usually at the position of a reciprocable drive means for pan-sweeping restricted arc flights.

The mining machine comprises a main frame or body 15 at the front of the conveyor which main frame or body is stakeable floor-to-roof by pairs of oppositely acting prop rams 16, 17 and is pivotally attached to a translation mechanism 18 on the guide rail 12.

Within the frame or body 15 is a ram-andcylinder drive for extension and retraction of a boom 20 carrying a multi-arm manipulable mount 21 for a selective mining head 22.

Specifically, a shallowly C-shaped middle link 23 is pivoted at one end 14 to a rearwardly offset first link 25 to the boom 20 and at its other end 26 to a mining head mounting link 27. The linkage is operated by rams 28 and 29 acting, respectively via pivotal connections, between an extension 30 of the link 23 and the boom 20 and between an extension 31 of the head mount link 27 and a fixed position 32 on the middle link 23.

The head 22 is of an impacting type, preferably having a hydraulically retracted hammer, piston driven for impacting by compression of a trapped volume of gas. As shown, a shortstroke head is movable along the length of the mounting link 27 by a fixed piston 33 and movable cylinder 34 arrangement called "crowd". The "crowd" is itself rotatable within a selectively braked or clutched bearing 35 by a hydraulic motor 36, see for example co-pending application no. 28403/76 (Serial No. 1585119).

The boom 20 is rotatable under power and indexable so as to give complete maneouvrability of the selective mining head, perhaps particularly for digging strike gulleys in a stope mining system and is shown inmore detail in Figure 2 and 3.

The boom 20 comprises a generally tubular member slidably mounted in the machine main frame casing 60 and has a portion 61 of larger internal diameter at its forward end. The larger diameter end portion partially accommodates the head manipulating ram 28 with its inner end 62 pivoted at 63 to the boom.

Inside the rearward part of the boom is a coaxial hydraulic ram arrangement 65 which serves to extend and retract the boom relative to the main frame casing 60, the boom being shown fully retracted in the drawings.

Splines 66 extending along the outside of the rear part of the boom 20 engage between corresponding teeth 67 of a surrounding short collar 68, which is rotatable within he main frame casing but secured against longitudinal movement relative thereto by pawls 69 secured to the casing 60 and protruding into a circumferential groove 70 of the collar 68. A hydraulic ram 71 serves to positively rotate the collar 68 and hence the beam 20. The ram 71 is pivoted at one end 72 to the main frame 15 of the machine and at its other end is coupled to the collar to act about the beam axis, by way of a clevis 73, providing pivotal securement for the end of the ram by means of a bolt 74.

The clevis 73 fits between axially spaced circumferential flanges 75 and 76 of the collar 68 and is secured to the collar by a pin 77 exten ding through holes 78, 79 and 80 of the flanges 75, 76 and clevis 73 respectively.

Additional pairs of registering holes 78 and 79 are provided spaced around the flanges of the collar so that the radial position at which the ram 71 acts against the collar, and hence the boom, may be adjusted in steps, i.e. indexed, by removing the pin 77, sliding the clevis 72 around the collar 68 to align with a different pair of holes, then replacing the pin. Clearly, it will be generally advantageous, even necessary for safety reasons to make provision against free boom rotation during such adjustment, and this is readily provided by a locking latch or pin temporarily actuated or fitted to hold the flanged collar relative to the machine casing 60 or by a pawl engaging the splines 66, or any other convenient braking or clamping means.

Generally, the range of extension of the ram 71 will be sufficient for most cutting operations, save perhaps for cutting strike gulleys wholly from a stope end position, and the indexing mechanism will be employed relatively infrequently. Then access to the pin 77 may be satisfactorily achieved by removing a part of the machine casing. Should a particular application require more frequent use of the indexing mechanism, obviously readier access could be provided.

The use of a hydraulic ram as part of the drive coupling for rotating the boom enables the machine to withstand more readily torque loadings which are too great for conventional drives such as employing fluid motor driven gearing. Since the extension of the arm is generally horizontally of the machine body no increase in height of the machine is required.

Embodiments of the invention are particularly advantageous where a machine is to operate in situations where a requirement that the face height be minimised, such as in gold mining, imposes limitations on the permissible height of the machine.

WHAT WE CLAIM IS: 1. A machine comprising a main frame having a boom supporting a tool head in the form of an impact-type rock breaker, which boom is axially extensible from the main frame and is positively rotatable about its axis by means of a drive coupling from a linearly

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (15)

**WARNING** start of CLMS field may overlap end of DESC **. Figure 2 is a sectional side view of a portion of the machine. Figure 3 is a sectional end view of a part of the machine. The machine shown in Figure 1 is described in greater detail in our co-pending application no. 19478/77 (Serial No. 1597972). Briefly, a mine face conveyor 10 comprises end-to-end articulated pans 11 with a relatively rearward mining machine guide rail 12 overlying the pans, usually at the position of a reciprocable drive means for pan-sweeping restricted arc flights. The mining machine comprises a main frame or body 15 at the front of the conveyor which main frame or body is stakeable floor-to-roof by pairs of oppositely acting prop rams 16, 17 and is pivotally attached to a translation mechanism 18 on the guide rail 12. Within the frame or body 15 is a ram-andcylinder drive for extension and retraction of a boom 20 carrying a multi-arm manipulable mount 21 for a selective mining head 22. Specifically, a shallowly C-shaped middle link 23 is pivoted at one end 14 to a rearwardly offset first link 25 to the boom 20 and at its other end 26 to a mining head mounting link 27. The linkage is operated by rams 28 and 29 acting, respectively via pivotal connections, between an extension 30 of the link 23 and the boom 20 and between an extension 31 of the head mount link 27 and a fixed position 32 on the middle link 23. The head 22 is of an impacting type, preferably having a hydraulically retracted hammer, piston driven for impacting by compression of a trapped volume of gas. As shown, a shortstroke head is movable along the length of the mounting link 27 by a fixed piston 33 and movable cylinder 34 arrangement called "crowd". The "crowd" is itself rotatable within a selectively braked or clutched bearing 35 by a hydraulic motor 36, see for example co-pending application no. 28403/76 (Serial No. 1585119). The boom 20 is rotatable under power and indexable so as to give complete maneouvrability of the selective mining head, perhaps particularly for digging strike gulleys in a stope mining system and is shown inmore detail in Figure 2 and 3. The boom 20 comprises a generally tubular member slidably mounted in the machine main frame casing 60 and has a portion 61 of larger internal diameter at its forward end. The larger diameter end portion partially accommodates the head manipulating ram 28 with its inner end 62 pivoted at 63 to the boom. Inside the rearward part of the boom is a coaxial hydraulic ram arrangement 65 which serves to extend and retract the boom relative to the main frame casing 60, the boom being shown fully retracted in the drawings. Splines 66 extending along the outside of the rear part of the boom 20 engage between corresponding teeth 67 of a surrounding short collar 68, which is rotatable within he main frame casing but secured against longitudinal movement relative thereto by pawls 69 secured to the casing 60 and protruding into a circumferential groove 70 of the collar 68. A hydraulic ram 71 serves to positively rotate the collar 68 and hence the beam 20. The ram 71 is pivoted at one end 72 to the main frame 15 of the machine and at its other end is coupled to the collar to act about the beam axis, by way of a clevis 73, providing pivotal securement for the end of the ram by means of a bolt 74. The clevis 73 fits between axially spaced circumferential flanges 75 and 76 of the collar 68 and is secured to the collar by a pin 77 exten ding through holes 78, 79 and 80 of the flanges 75, 76 and clevis 73 respectively. Additional pairs of registering holes 78 and 79 are provided spaced around the flanges of the collar so that the radial position at which the ram 71 acts against the collar, and hence the boom, may be adjusted in steps, i.e. indexed, by removing the pin 77, sliding the clevis 72 around the collar 68 to align with a different pair of holes, then replacing the pin. Clearly, it will be generally advantageous, even necessary for safety reasons to make provision against free boom rotation during such adjustment, and this is readily provided by a locking latch or pin temporarily actuated or fitted to hold the flanged collar relative to the machine casing 60 or by a pawl engaging the splines 66, or any other convenient braking or clamping means. Generally, the range of extension of the ram 71 will be sufficient for most cutting operations, save perhaps for cutting strike gulleys wholly from a stope end position, and the indexing mechanism will be employed relatively infrequently. Then access to the pin 77 may be satisfactorily achieved by removing a part of the machine casing. Should a particular application require more frequent use of the indexing mechanism, obviously readier access could be provided. The use of a hydraulic ram as part of the drive coupling for rotating the boom enables the machine to withstand more readily torque loadings which are too great for conventional drives such as employing fluid motor driven gearing. Since the extension of the arm is generally horizontally of the machine body no increase in height of the machine is required. Embodiments of the invention are particularly advantageous where a machine is to operate in situations where a requirement that the face height be minimised, such as in gold mining, imposes limitations on the permissible height of the machine. WHAT WE CLAIM IS:

1. A machine comprising a main frame having a boom supporting a tool head in the form of an impact-type rock breaker, which boom is axially extensible from the main frame and is positively rotatable about its axis by means of a drive coupling from a linearly

movable actuator.

2. A machine according to Claim 1, wherein the actuator comprises an extensible and retractable drive arm.

3. A machine according to Claim 2, wherein the drive arm comprises a pressure-fluid-operated ram.

4. A machine according to Claim 3, wherein the ram is hydraulic.

5. A machine according to Claim 2, 3 or 4, wherein the drive arm is pivotally coupled at or near one end to the main frame and at or near its other end to the drive coupling.

6. A machine according to any preceding Claim, wherein the drive coupling comprises a member rotatable with the boom which is slidable relative to the member.

7. A machine according to Claim 6, wherein the member is a collar about the boom and internally formed to mate with longitudinal splining of the boom.

8. A machine according to Claim 7, wherein the collar is flanged for coupling to the actuator.

9. A machine according to Claim 8, wherein the collar has two spaced flanges about its exterior to receive and locate the actuator or a part coupled thereto.

10. A machine according to Claim 9, wherein said part comprises a clevis located between the flanges by bolting or pinning through registering holes.

11. A machine according to any preceding Claim, wherein the drive coupling has optional connection positions to the actuator which positions are spaced circumferentially of the boom.

12. A machine according to Claim 11 with Claim 10, wherein said positions comprise spaced registering holes in the flanges.

13. A machine according to any preceding Claim, wherein said boom has at its tool mounting end an internal recess within which is pivotally mounted a ram for actuating a manipulating linkage for the tool head.

14. A machine having a boom supporting an impact type rock breaker arranged and adapted to perate substantially as herein described with reference to and as shown in Figures 2 and 3 of the accompanying drawings.

15. A mining machine having a boom supporting an impact type rock breaker, arranged and adapted to operate substantially as herein described with reference to and as shown in Figures 1, 2 and 3 of the accompanying drawings.