Tool Positioning Extensible Boom

Abstract

An extensible boom, particularly for mounting on a mobile rock breaking or mining machine, comprises an extensible member mounted for rotation about an axis extending in the direction of its length, a non-rotatable extensible member operative to impart extension to said rotatable member of the boom, means for extending the non-rotatable extensible member of the boom and means on said rotatable member of the boom for mounting a rock breaking or other tool thereon so that said tool operates on an axis which is different to said axis of the rotatable member of the boom and is movable relatively thereto. In one preferred arrangement the tool is supported on a tiltable turntable pivotally mounted on the forward end of the boom. This invention is for improvements in or relating to an extensible boom for carrying and positioning or guiding a tool. One particular application of the invention is to a boom for carrying and applying a rock breaking tool to a rock or other mineral face for the excavation or breaking down thereof. According to the present invention there is provided an extensible boom in which one extensible member of the boom is also adapted for rotation about an axis extending in the direction of its length and another and non-rotatable extensible member of the boom imparts such extension to said rotatable member of the boom, means being provided for extending the non-rotatable extensible member of the boom, said rotatable member providing a mounting for a tool which operates on an axis which is different to said axis of the rotatable member and is movable relatively thereto. Conveniently, the boom comprises a fixed or stationary outer member, a rotatable inner extensible member, a non-rotatable, slideable intermediate extensible member, means for effecting sliding movement of said intermediate member and interengaging or connecting means between the intermediate member and the rotatable inner member whereby they are together extended and retracted. In one preferred embodiment of the invention rotation of the extensible inner member is effected through a splined drive shaft rotatably mounted on the stationary outer member and on which the inner member is slideable.

Description

One particular embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a diagrammatic longitudinal sectional view of a boom,

FIG. 2 is a more detailed longitudinal elevation of the boom with the upper half in section,

FIG. 3 is a cross-sectional view of the rotary driving mechanism of the boom shown in FIG. 2,

FIG. 4 is a side elevation of a mobile rock breaking or mining machine fitted with a boom as shown in FIGS. 1, 2 and 3,

FIG. 5 is a rear elevation of the machine shown in FIG. 4, and

FIG. 6 is a plan view of the machine shown in FIG. 4.

The boom shown in FIG. 1 comprises a stationary outer cylindrical casing 10, an intermediate hollow cylindrical member 11 slideable in the casing 10, and an inner hollow cylindrical member 12 slideable and rotatable in the intermediate member 11. The intermediate member 11 is held against rotation in the casing 10 by a key 13.

Rotation of the inner member 12 is effected by hydraulic motor 14, mounted on the casing 10, which, through worm and worm-wheel gearing 15 and 16, drives a splined shaft 17 on which the inner member 12 is slidably mounted and to which it is keyed for rotation as indicated at 18. The worm and worm-wheel gearing is housed in an enlargement 10a of the outer casing 10. The worm and worm-wheel gearing has the advantage that the inner member 12 is automatically locked against rotation except when the motor 14 is operating because the worm-wheel cannot drive the worm. Instead of a worm and worm-wheel a crank and connecting rod arrangement may be used.

A double-acting hydraulic ram 19 is connected between a lug 20 on the stationary member 10 and a lug 21 on the intermediate member.

Interengaging abutments 22 and 23 are provided between the inner and intermediate members at the rear ends thereof and interengaging abutments 24 and 25 are provided between said members at the forward ends thereof.

When the intermediate member 11 is extended, by extending the ram 19, the abutments 22 and 23 cause the inner rotatable member 12 to be extended. By operating the motor 14 the inner member 12 can be rotated.

Retraction of the intermediate member 11 by the ram 19 will, through the abutments 24 and 25, retract the rotatable member 12.

The extending means for the boom (e.g., the ram 19) may be external of the fixed member 10 or internal and there may be more than one such extending means.

The ram 19 can be used as a hydraulic lock to hold the boom against extension or retraction, the control valve means for the ram being adapted for that purpose. Similarly the hydraulic motor 14 can be adapted to operate as a hydraulic lock to hold the member 12 against rotation.

The boom shown in greater detail in FIGS. 2 and 3 is basically of the same construction as that above described with reference to FIG. 1 and like reference numerals have been used to designate like parts.

The mining machine shown in FIGS. 4, 5 and 6 is similar in construction, with the exception of the boom, to the machine described in the Specification of our patent Application Ser. No. 198,365.

Briefly, the machine comprises a walking carriage 27 on which is mounted a chassis 28 and a turntable 29. The turntable 29 supports, for angular movement about a vertical axis 30, bearing brackets 31 which support, for angular movement about a horizontal axis 32, a bearing bracket 33 formed on the enlargement 10a of the outer cylindrical casing 10 of the boom. Thus, the boom is supported on the chassis so that it can be angled both laterally and vertically.

Said lateral angular movement of the boom is effected by a hydraulic ram 34 and the vertical angular movement of the boom is effected by a hydraulic ram 35.

The rock breaking equipment 26 comprises a boom extension 36 secured to the forward end 12a of the rotatable extensible member 12, said extension having pivotally mounted on its forward end, for adjustment about an axis 37, a tiltable turntable 38. Adjustment of the table 38 about the axis 37 is effected by a hydraulic ram 39 and about an axis 37a by a further ram, not shown. A pressure-fluid operated rock breaking tool 40, which actuates a chisel 26a, is mounted on the table 38 and may be adjustable therealong. This pressure-fluid operated rock breaking tool may be constructed as described in the Specification of our Application for Patent Ser. No. 218,671.

It will be noted that the table 38 provides a mounting, on the rotatable member 12 of the boom, for a tool which operates on the axis I--I which is different from the axis II--II of the rotatable member 12 and is movable relatively to the said axis II--II. More particularly, the axis I--I can be rotated around the axis II--II of the boom, by rotating the member 12 by the motor 14, and also the axis I--I can be tilted about the pivot 37 relative to the axis II--II.

Thus, to apply the tool 26a to a particular part of a mineral face there is the ability to raise or lower the boom and swing it laterally, extend or retract the boom, rotate the tool in a circular path about the axis of the boom and tilt the tool outwardly or inwardly, with respect to the boom, about the pivot 37.

Claims

I claim:

1. An extensible boom comprising a fixed or stationary outer member, a non-rotatable intermediate extensible member slidably mounted in said outer member, an inner extensible member mounted in said intermediate member for rotation about an axis extending in the direction of its length, means for effecting sliding movement of said intermediate member, inter-engaging means between the intermediate member and the rotatable inner member whereby they are together extended and retracted, and means on said rotatable member of the boom for mounting a tool thereon so that said tool operates on an axis which is different to said axis of the rotatable member of the boom and is movable relative thereto.

2. A boom as claimed in claim 1, wherein the axis of the tool is movable about the axis of the rotatable member of the boom.

3. A boom as claimed in claim 1, wherein the axis of the tool is tiltable with respect to the axis of the rotatable member of the boom.

4. An extensible boom as claimed in claim 1, wherein the means for extending the non-rotatable extensible member of the boom is a pressure-fluid ram.

5. An extensible boom as claimed in claim 1, wherein the rotatable extensible member of the boom is slidable on a splined shaft provided with means whereby it can be rotated.

6. An extensible boom as claimed in claim 1, wherein rotation of the extensible inner member is effected by a drive shaft rotatably mounted on the stationary outer member and on which drive shaft the inner member is slidable and to which it is keyed.

7. An extensible boom as claimed in claim 1, wherein rotation of the rotatable extensible member of the boom is effected by a motor.

8. An extensible boom as claimed in claim 1, wherein rotation of the inner member is effected by a motor mounted on the fixed or stationary outer member.

9. An extensible boom as claimed in claim 1, wherein rotation of the rotatable extensible member of the boom is effected through worm and worm-wheel gearing.

10. An extensible boom as claimed in claim 1, wherein a double-acting pressure-fluid ram, for extending the intermediate member of the boom, is connected between said member and the fixed or stationary outer member.

11. An extensible boom as claimed in claim 1, wherein interengaging abutments are provided between the inner member and intermediate member at the rear ends thereof and between said members at the forward ends thereof whereby extension and retraction of the intermediate member extends and retracts the inner member.

12. An extensible boom as claimed in claim 1, and having, pivotally mounted on its forward end, support means for a tool.

13. An extensible boom as claimed in claim 12, wherein said support means includes a tiltable turntable.

14. A boom as claimed in claim 1, wherein at least one of the extensible members may be held against extension or retraction or the rotatable member may be held against rotation.

15. A boom as claimed in claim 14, wherein at least one of the extensible members is held against extension or retraction or the rotatable member is held against rotation by making provision for a hydraulic lock in hydraulic operating means for said members.

16. A boom as claimed in claim 14, wherein a driving motor for the rotatable member is geared to said member by a mechanism which locks said member against rotation except when said driving motor is in operation.

17. An extensible boom as claimed in claim 1 and having rock breaking equipment mounted on its forward end.

18. An extensible boom as claimed in claim 17 and having means mounting it on a mobile rock breaking or mining machine.