Mineral Mining Machine Steering Means

Abstract

This invention relates to steering means in a mineral mining machine of the type having cutting elements at each end thereof, said elements being capable of being raised or lowered to cut and form a roof or to cut and form a floor and said cutting elements being either rigidly mounted to the machine body or mounted on ranging arms pivotally mounted to the machine body. The steering means provides for controlling the height of a leading floor mounted support for the machine on the face side of the machine to suit variations in the horizontal and vertical plane of the leading cutting element and thereby maintain the transverse plane of the machine body on a predetermined plane. The steering means includes hydraulic servo control means connected to hydraulic jacks for the support members and adjustable detecting means, responsive to change in the predetermined transverse plane of the machine, operate valve means to actuate the hydraulic jack on the leading support member to maintain the machine body in said predetermined plane.

Description

This invention relates to mineral mining machine steering means.

More particularly the invention relates to steering means for a mining machine of the type having cutting elements at each end, the cutting elements being capable of being raised or lowered to cut and form a roof or to cut and form a floor. The leading cutting element cuts and forms the floor and the trailing cutting element cuts and forms the roof.

The machine may be built with the usual unit construction comprising a power unit, haulage winch unit and gearbox units to drive the cutting elements, and the machine is supported by support elements which are located as close as possible to the cutting elements. A pair of support elements is provided for each cutting element, one support element of each pair is located on the face side of the machine and supported on the floor and the opposite support element of each pair is located on the gob side of the machine and supported on the floor or on a face conveyor or conveyor structure and is captive to the conveyor or conveyor structure.

The face side of the machine is the side adjacent the mineral face to be cut and the gob side is the side of the machine remote from the mineral face and adjacent the face conveyor.

The cutting element at each end of the machine may be of the ranging arm type in which the elements are each mounted on an arm which is adjustable in height so that the plane of cutting can be varied in relation to the machine body.

Alternatively the cutting elements may be rigidly mounted on each end of the machine and the plane of cutting is varied by raising or lowering one end of the machine relative to the other end of the machine. Such machines are hereinafter referred to as machines of the type referred to.

In machines of the type referred to where the leading cutting element is cutting and forming the floor slightly in advance of the leading support elements, difficulty has been found in steering the machine so as to maintain the transverse plane of the machine body on a predetermined plane relative to the plane of advance of the mineral face.

The present invention provides a means for controlling the height of the leading floor mounted support on the face side of the machine to suit variations in the horizontal and vertical plane of the leading cutting element and thereby maintaining the transverse plane of the machine body on a predetermined plane.

According to the invention a mineral mining machine of the type referred to includes steering means comprising hydraulic servo control means in a hydraulic circuit operatively connectable to a hydraulic jack for a leading support member on the face side of the machine, adjustable means in the hydraulic circuit for detecting a predetermined transverse plane of the machine body, said detecting means responsive to change in said transverse plane to operate a valve member to provide a pressure differential in the hydraulic circuit which is applied to an intensifier in the form of a double-acting piston to actuate valve means which actuate the leading hydraulic jack to maintain the machine body in said predetermined plane.

The detecting means may be provided by an adjustable pendulum oscillatable about an axis parallel to the longitudinal axis of the machine body.

The valve member may comprise a double nozzle flapper valve or a swinging nozzle valve associated with the pendulum or the arm member.

Embodiments of the invention illustrated by way of example in the accompanying drawings in which:

FIG. 1 is an elevational view from the gob side of a mining machine of the type referred to having cutting elements at each end of the machine each mounted at the end of a ranging arm which is adjustable in height so that the plane of cutting can be varied in relation to the machine body;

FIG. 2 is a side elevation of the machine of FIG. 1 taken from the face side of the machine;

FIG. 3 is a plan view of the machine of FIG. 1;

FIG. 4 is a sectional view on the line 4--4 of FIG. 3 showing one embodiment of steering means;

FIG. 5 is a side elevation of the gob side of a mining machine of the type referred to incorporating a further embodiment of the invention;

FIG. 6 is a plan view of the machine of FIG. 5;

FIG. 7 is a sectional view on the line 7--7 of FIG. 6;

FIG. 8 is a diagrammatic illustration of one embodiment of a hydraulic servo control circuit;

FIG. 9 is a diagrammatic illustration of another embodiment of a hydraulic servo control circuit;

FIG. 10 is a diagrammatic illustration of a further embodiment of a hydraulic servo control circuit.

Referring to FIGS. 1 to 4 of the drawings 1 denotes generally a mining machine of the type referred to having a power unit 2, a haulage winch unit 3 and gearbox units 4 to drive cutting elements 5 mounted at each end of the machine.

The cutting units may, as illustrated, comprise a drum 6 having cutting picks 7 mounted on helical flanges 8.

The cutting elements 5 are of the ranging arm type in which the elements 5 are each mounted on an arm 9 which is adjustable in height so that the plane of cutting can be varied in relation to the machine body.

The mineral machine is supported by support elements 10, 10a and 11, 11a arranged in pairs at each end of the machine as close as possible to the cutting elements.

The gob side of the machine 1 is supported by support elements 10 and 11 which comprise two skid shoes each rigidly attached to an end of the machine as near as possible to the cutting elements 5. The shoes 10 and 11 are carried by the face side 12 of a face conveyor or conveyor structure 13 and are captive to the conveyor for sliding movement along the conveyor.

The face side of the machine is supported by support elements 10a and 11a which comprise two floor mounted skid shoes located one at each end of the machine as near as possible to the cutting elements 5.

Each of the skid shoes 10a and 11a on the face side of the machine is attached to the lower end of a vertically slidable guide 14 and a hydraulic jack 15 is interposed between the vertical guide and the machine body so that the height of the machine body from the floor at the face side of the machine can be varied by operation of the jacks.

Hydraulic servo control means, which will be described later, is provided whereby the hydraulic jack associated with the leading floor mounted support element on the face side of the machine can be actuated so that, if the transverse plane of the machine body departs from a predetermined plane, which would normally be the plane of advance of the mineral face, the jack for the leading floor mounted support element will operate to restore the machine body to the predetermined plane.

The jack associated with the floor mounted support element at the trailing end of the machine is supplied with a substantially constant fluid pressure to support approximately half of the weight of the trailing end of the machine.

The inoperative or zero position of the servo control means can be adjusted so that the predetermined transverse plane of the machine body can be other than the plane of advance of the coal face.

Referring now to FIGS. 5 to 7 where like elements are referred to by the same reference numerals as the above described embodiment, the cutting elements 5 at each end of the machine are rigidly mounted to the machine body so that, to cut and form a floor the leading end of the machine is lowered to lower the cutting element 5 at that end and the trailing end of the machine is raised to raise the cutting elements 5 at that end of the machine to cut and form a roof.

The gob side of the machine is supported on two skid shoes 10 and 11 located as near as possible to the cutting elements. The shoes are each carried on the face side 12 of the face conveyor or conveyor structure 13 and are captive to the conveyor for sliding movement along the conveyor. Alternatively the shoes may be located on the floor adjacent the conveyor 13 and captive to the conveyor for sliding movement along the conveyor.

The shoes 10 and 11 are each mounted at one end of an associated slidable guide member 14 which is operated by a hydraulic jack 15a attached to the machine frame for adjusting the height of the shoes and therefore the height of that side of the machine.

The adjusted position of the gob side shoes is determined by manual operation of the hydraulic jacks 15a, the operator positioning the leading shoe so that the cutting element cuts and forms a floor and positioning the trailing shoe so that the cutting element at that end of the machine cuts and forms a roof.

The face side of the machine is provided with floor mounted supports or skid shoes 10a and 11a identical with those of the first mentioned embodiment with the leading face side support having hydraulic servo control means while the trailing face side support may be hydraulically coupled in parallel with the gob side trailing shoe to share the weight of the trailing end of the machine.

The hydraulic servo control means is provided by a hydraulic circuit adapted to be connected to the jack associated with the leading support or skid shoe on the face side of the machine.

One embodiment of the hydraulic circuit is illustrated in FIG. 8 of the accompanying drawings and is provided by a pump P supplying hydraulic fluid through restriction means 20 to each nozzle of a double nozzle flapper valve which is actuated by a pendulum 21 adjustably suspended for oscillation about an axis parallel to the longitudinal axis of the machine body. The flapper valve comprises a pair of nozzle members 22 and 23 arranged one on each side of the arm of the pendulum 21 to direct a jet of hydraulic fluid in the direction of the pendulum arm so that when the pendulum swings in one direction the nozzle at that side of the pendulum is blocked or partially blocked while the opposite nozzle is clear thus a pressure differential is built up in the conduits leading to the nozzle members. The conduits are connected one to each side of an intensifier 24 formed by a double acting piston and the pressure differential is transmitted to the double acting piston 24 which provides a force to actuate valve means 25 in a hydraulic circuit supplied by a second pump P which is connected via a flow control valve 26 to the jack for the leading support to raise or lower the jack.

The first pump P also supplies a constant pressure to the jack for the trailing support means on the face side of the machine. A manually operable change-over valve 29 is connected in both hydraulic circuits so that when the direction of travel of the machine is changed the hydraulic circuits can be directed to their respective jacks.

In another embodiment of the hydraulic servo control means illustrated in FIG. 9 of the drawings which is similar to the embodiment of FIG. 8 except that the double nozzle flapper valve is substituted by a swinging nozzle valve 27 in which hydraulic pressure is supplied to a nozzle 28 associated with the pendulum 21 mounted for oscillation about an axis parallel to the longitudinal axis of the machine body to direct a jet of hydraulic fluid under pressure in the direction of the ends of two hydraulic lines 32 and 33 arranged in the line of oscillation of the nozzle 28 and each connected to opposite sides of the intensifier 24 which is in the form of a double acting piston operatively connected to the valve means 25 in the second hydraulic circuit.

A further embodiment of the hydraulic servo control means is illustrated in FIG. 10 of the drawings which is similar to the embodiment of FIG. 8 except that the pump P only provides constant pressure to the jack for the trailing support means. A third pump P.sub.3 supplies hydraulic fluid to a pair of jets 30 and 31 which are aligned with openings in conduits 32 and 33 connected one to each side of the double acting piston 24.

A jet disturbing plate 34 is interposed between the jets 30,31 and conduits 32, 33 and is so arranged that in a mid neutral position the plate 34 is clear of the jets and conduits allowing free flow of fluid.

The pendulum 21 is operatively connected to the plate 34 to swing the plate in one extreme position between the jet 30 and conduit 32 to cut-off the supply of fluid through the conduit to an opposite extreme position cutting-off communication between the jet 31 and conduit 33.

The pendulum is provided with adjustment means 35 which provides for altering the relative angular position of the plate 34 to the pendulum arm thereby varying the neutral or zero position of the plate or pendulum control.

The plate 34 is connected to the arm of the pendulum by an arm 36 which is angularly adjustable relative to the arm of the pendulum by screw threaded means 35.

Claims

What is claimed is:

1. A mineral mining machine of the type referred to including steering means comprising hydraulic servo control means in a hydraulic circuit operatively connectible to a hydraulic jack for a leading support member on the face side of the machine, adjustable pendulum means oscillatable about an axis parallel to the longitudinal axis of the machine to detect transverse tilting of the machine from a predetermined position and responsive to said tilting to operate a valve member in the hydraulic circuit to provide a pressure differential, said pressure differential applied to an intensifier, said valve member comprising a pair of nozzles aligned with the open ends of a pair of conduits, said conduits connected to opposite ends of said intensifier, a jet disturbing member operatively connected to said pendulum and interposed between said nozzles and said conduits and movable between one extreme position in which the jet disturbing member cuts-off the supply of hydraulic fluid from one nozzle to its associated conduit to another extreme position in which the supply of hydraulic fluid from the other nozzle to its associated conduit is cut-off, said intensifier comprising a double acting piston to actuate valve means, said valve means operable to actuate said leading hydraulic jack to maintain the machine in said predetermined position.

2. A mineral mining machine according to claim 1 in which the support members on the gob side of the machine are rigidly attached to the machine and the cutting elements are each mounted on an adjustable arm at the ends of the machine.

3. A mineral mining machine according to claim 1 in which the cutting elements at each end of the machine are rigidly mounted to the machine, the support members on the gob side of the machine are each mounted on a vertically slidable guide member, said guide members each actuated by a manually operable hydraulic jack for raising or lowering the support members, and the trailing support member on the face side of the machine is operatively connected to a jack hydraulically coupled in parallel with the gob side trailing support member.

4. A mineral mining machine of the type referred to including steering means comprising hydraulic servo control means in a hydraulic circuit operatively connectible to a hydraulic jack for a leading support member on the face side of the machine, adjustable pendulum means oscillatable about an axis parallel to the longitudinal axis of the machine to detect transverse tilting of the machine from a predetermined position and responsive to said tilting to operate a valve member in the hydraulic circuit to provide a pressure differential, said pressure differential applied to an intensifier, said valve member comprising a swinging nozzle valve in which an oscillatable nozzle is operatively connected to said pendulum arm to direct a jet of hydraulic fluid in the direction of the open ends of two hydraulic lines arranged in the line of oscillation of the nozzle and each of said hydraulic lines being connected to an opposite side of intensifier, said intensifier operable to actuate valve means, said valve means operable to actuate said leading hydraulic jack to maintain the machine in said predetermined position.