US3537754A

US3537754A - Apparatus for moving a mining machine relative to a face being worked

Info

Publication number: US3537754A
Application number: US769648A
Authority: US
Inventors: Alfred Valantin
Original assignee: Charbonnages de France CDF
Current assignee: Charbonnages de France CDF
Priority date: 1967-10-27
Filing date: 1968-10-22
Publication date: 1970-11-03
Anticipated expiration: 1987-11-03
Also published as: DE1805341A1; FR1548671A; GB1222229A; BE721791A; DE1805339A1; CA918688A

Description

A A. VALANTIN 3,537,754 APPARATUS FOR MOVING A MINING MACHINE RELATIVE Nov. 3, 1970 TO A FACE BEING WORKED l0 Sheets- 55991; 2

Filed Oct. 22. 1968 I Nov. 3, 1 9170 A. VALANT'IN j 3,537,754

APPARATUS FOR MOVING A MINING MACHINE RELATIVE' To A FACE BEING WORKED Filed Oct. 2 2. 1968 v 10 She etS-Sheet 1 Nov. 3, 1970 A. VALANTIN 3,537,754

' APPARATUS FOR MOVING A MINING MACHINE RELATIVE TO A FACE BEING WORKED Filed 001;. 22, 1968 10 Sheets-Sheet 3 1 1 'go i NOV: 3, ,1970 A. VALANTIN 3,537,754

APPARATUS FOR MOVING A MINING MACHINE RELATIVE TO A FACE BEING WORKED Nov. 3, 1970 A. VALANTIN VING A MINING MACHINE RELATI A FACE BEING WORKED j APPARATUS FOR MO 10 Sheets-Sheet 5 Filed Oct. 22, 1968 Nov. 3, 1970 A. VALANTIN 3,537,754

APPARATUS FOR MOVING A MINING MACHINE RELATIVE TO A FACE BEING WORKED Filed Oct; 22. 1968 10 Sheets-Sheet 6 Nov. 3,' 1970 A. VALANTIN 3,537,754

APPARATUS FOR MOVING A MINING MACHINE RELATIVE TO A FACE BEING WORKED Filed Oct, 22, 1968 10 Sheets-Sheet 7 Nov; 3, 1970 A. VALANT lN 3 537,754

' APPARATUS FOR MOVING A MINING MACHINE RELATIVE TO A FACE BEING WORKED 1 Filed Oct. 22, 1968 10 Sheets-Sheet 8 A. VALANTIN 3,537,754 ov A MINING MACHINE RELATIVE A E BEING WORKED Nov. 3, 1970 APPARATUS F0 Filed 001.,22, 1968 10 Sheets-Sheet 9 FIG. 22

FIG. 23

' Nov. 3,1970

Filed 001;. 22) 1968 APPARATUS FOR MOVING A MINING MACHINE RELATIVE TO A FACE BEING WORKED lIo Sheets-Sheet 10 FIG. 24

A. VALA NTIN 3,537,754

United States Patent 01 3,537,754 Patented Nov. 3, 1970 ace Int. c1. E21c 29/02 US. Cl. 299-32 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to devices for the displacement of an ore-mining machine along the cutting face, while being supported on a longitudinal guide of rigid elements of constant section, held fixed at least momentarily with respect to said cutting face, said devices comprising at least one double-acting jack and at least a pair of jaws located on each side of said longitudinal guide, one of said jaws being free in orthogonal translation while the other is coupled to one element of the jack, the other element being rigidly coupled to the machine, and means for successively. and alternatively bringing closer together and separating said jaws in synchronism with the alternative movements of said jack.

The displacement of ore-mining machines of the kind which move along a cutting face is mainly obtained by two different methods:

The machine is towed, by means of a winch installed on the machine itself, along a chain stretched between two fixed points located at the extremities of the cutting face;

The machine is drawn by a chain winding on a winch installed at an extremity of the cutting face.

In both these cases, it is found that the movement of the machine is frequently pulsating, which may have serious repercussions on the behavior of the mechanical parts.

There are many reasons for this:

Elasticity of the chain;

The actual nature of the cutting action, which is a discontinuous tearing-away of more or less large lumps of ore;

Variations of the coefiicient of friction between the machine and the surface on which it slides, whether the latter is the ground or a metal surface (metal-cased conveyor, for example).

Different orders of magnitude of the coefficient of friction and the coetficient of slip between the machine and the surface on which it slides;

Variations of the mechanical characteristics of the material to be cut (hardness);

Variations of its nature and its degree of heterogeneity.

Most of the solutions proposed for reducing the effects of pulsation in the movement of the machine tend to eliminate or to overcome the jerks due to variations of the coeflFicient of friction, but not those due to the nature of the material to be cut, in which the variations of characteristics are the cause of random variations in the length of the chain.

The present invention relates to devices more particularly adapted to displace the machine along a cutting face,

without utilizing a fixed or moving haulage chain, said machine being supported on a line of rigid elements of constant section so called longitudinal guide.

In the text which follows, the terms longitudinal translation or translation will designate any movement taking place parallel to the direction of a guide (as defined below) and the term orthogonal translation signifies any movement eifected transversely to the direction of this guide.

Generally speaking the translation of the machine with the devices in accordance with the invention is efiected by taking a support on a line of rigid elements of constant section (known as the longitudinal guide) held fixed, at least momentarily with respect to the said cutting face, by means of at least one double-acting jack, one of the elements of which is rigidly coupled to the said machine while the other element is supported on the said longitudinal guide by means of a gripping device having two positions, a gripping position and a sliding position, by first causing simultaneously the clamping movement of the said gripping device and one of the times of operation of the said jack and then simultaneously the sliding movement of the said gripping device and the other time of operation of the said jack.

In an alternative form, the translation of the machine is effected by means of two gripping devices.

According to another alternative form, the translation of the machine is effected by means of two gripping devices acting simultaneously, either in the gripping position or in the sliding position.

According to a preferred form of embodiment, the translation of the machine is eifected by means of two symmetrical gripping devices acting simultaneously and in a reversible manner, one in the gripping position, the other in the sliding position.

According to a characteristic feature, the said longitudinal guide is associated with the conveyor which evacuates the products out by the machine.

According to an alternative form, the longitudinal guide is constituted by all the protecting tubes of the return side of the haulage chain with which each hopper of an armoured scraped conveyor is normally equipped.

According to a further characteristic feature, the longitudinal guide is associated with a supporting assembly.

Thus the invention relates to devices for carrying the above displacement. The device is essentially composed of at least one double-acting jack and at least one gripping device, known in the text which follows as a gripping hand, which is associated with it, and is characterized in that:

The gripping hand comprises a body and two jaws, known in the text which follows as the lower jaw and the upper jaw, located on each side of the longitudinal guide, one jaw being free in orthongonal translation while the other is coupled to one of the elements of the jack, the other element of the jack being rigidly coupled to the machine which is to be moved; and

In that it comprises means for successively bringing together and separating the said jaws.

According to a characteristic feature, the said means for successively bringing together and separating the jaws are constituted by jamming devices.

According to a further characteristic feature, the said means are constituted by hydraulic clamping devices.

In accordance with a first form of embodiment, the said means for successively bringing together and separating the jaws are constituted by:

A first fiat jamming face, coupled rigidly to one of the jaws;

A second jamming face, rigidly coupled to the other jaw grooved with transverse imprints, forming with the first flat jamming face, pairs of secant planes converging in the same direction;

A roller with a transverse axis, mounted between the planes of each pair of secant planes;

Means of any type known per se, for continuously urging each roller in the direction of convergence of the planes of the said pairs of secant planes;

Means being provided for periodically reversing the direction of translation of the rod of the double-acting jack with respect to the body of the said jack.

According to an advantageous characteristic feature, the body of the double-acting jack is coupled for translation to the grooved face of the said transverse imprints.

According to a further advantageous characteristic, the said transverse imprints are symmetrical and a selector device is provided for urging the rollers into one or the other of the directions of convergence of the said secant planes.

According to a further characteristic feature, the angle of convergence of the secant planes is substantially 12.

In accordance with one form of embodiment of this jamming device:

The body of the gripping hand has the form of a C enclosing the longitudinal guide;

The lower part of the body of the gripping hand forms the lower jaw;

The internal face of the upper part of the body of the gripping hand constitutes the said second jamming face;

The upper jaw is located between the longitudinal guide and the said second jamming face;

The face of the upper jaw located facing the second jamming face constitutes the said first jamming face;

The body of the double-acting jack is coupled for translation to the body of the gripping hand;

The means for urging the rollers in one or the other of the directions of convergence of the pairs of secant planes are constituted, in a manner known per se, by a cage mounted between the jamming faces, provided with transverse stays located on each side of the rollers and each provided with spring push-rods acting in opposite directions;

A selector device is provided for placing the said cage in such manner that the rollers are in contact either with the push-rods acting in one direction or with the pushrods acting in the other direction;

The means for periodically reversing the direction of translation of the piston of the double-acting jack with respect to the body of the said jack are constituted by a four-way hydraulic fluid distributory with two positions, and devices, of any type known per se, for detecting the end-of-travel positions of the piston of the said jack and for controlling the change of the position of operation of the hydraulic distributor.

According to one preferred form of construction, the device for carrying into effect the method according to the invention comprises two gripping hands as defined above, and has the following characteristics:

The pistons of the double-acting jacks are coupled for translation by means of a synchronizing rod extending between the bodies of the said jacks;

The bodies of the double-acting jacks are coupled in translation in opposite directions by means of a chain winding over two pulleys located on each side of the two gripping hands, one of the straight sides of the chain being connected in translation to one of the bodies of the double-acting jacks, the other straight side of the chain being coupled in translation to the other body of the double-acting jack, the shafts of the pulleys being fixed to the body of the machine;

Means are provided for placing the cages in such manner that the spring push-rods urge the rollers of the two gripping hands in the same direction;

The double-acting jacks are supplied with hydraulic fluid by means of a four-way two-position distributor and two piping systems each opening into the bodies of the said jacks, symmetrically with respect to the centre of the synchronizing rod.

In accordance with a second form of construction, the said means for successively bringing together and separating the jaws are constituted by hydraulic clamping devices, comprising:

A clamping face, fiat and rigidly coupled to one of the jaws;

At least one single-acting jack rigidly coupled to the other jaw; and

Means for simultaneously applying a hydraulic pressure to the said single-acting jack and to one of the sides of the said double-acting jack, and then simultaneously connecting the single-acting jack to the tank and applying a pressure on the other side of the double-acting jack.

According to one form of embodiment of this hydraulic clamping device:

The body of the gripping hand has the form of a C surrounding the longitudinal guide;

The lower part of the body of the gripping hand forms the lower jaw;

The internal face of the upper part of the body of the gripping hand constitutes the said clamping face;

The upper jaw is hollowed out with at least one imprint, in which slides the piston of the single-acting jack;

The body of the double-acting jack is coupled in translation to the body of the gripping hand;

The means for periodically reversing the direction of translation of the piston of the double-acting jack with respect to the body of the said jack are constituted by a hydraulic fluid distributor with four ways and two positions, and devices of any type known per se for detecting the end of travel positions of the piston of the said jack and to control the change in position of operation of the hydraulic distributor;

The means for simultaneously applying the pressure to the single-acting jack and to one of the sides of the doubleacting jack are constituted by three-way distributor with two positions hydraulically actuated by the supply circuit of the double-acting jack;

A selector device is further provided so as to apply simultaneously a pressure on the single-acting jack and on one of the sides of the double-acting jack, or simultaneously on the single-acting jack and on the other side of the double-acting jack.

In accordance with a preferred form of embodiment, the device for carrying into effect the method according to the invention comprises two gripping hands of the hydraulic type described above, and having in addition the following characteristics:

The pistons of the double-acting jacks are coupled in translation by means of a synchronizing rod extending between the bodies of the said jacks;

The bodies of the double-acting jacks are coupled together in translation in opposite directions by means of a chain which winds over two pulleys located on each side of the two gripping hands, one of the straight sides of the chain being coupled in translation to one of the doubleacting jack bodies, the other straight side of the chain being coupled in translation to the other double-acting jack body, the shafts of the pulleys being fixed on the body of the machine;

The double-acting jacks are supplied with hydraulic fluid by means of a four-way distributor with two positions and two conduit systems each opening into the bodies of the said jacks, symmetrically with respect to the centre of the synchronizing rod;

Means are provided for simultaneously applying a pressure on the single-acting jack of one of the gripping hands and on one of the conduit systems opening into the doubleacting jack bodies and then simultaneously on the singleacting jack of the other gripping hand and on the other conduit opening into the double-acting jack bodies.

Other characteristic features and advantages of the present invention will be brought out in the description which follows below, reference being made to the accompanying drawings in which:

FIGS. 1 and 2 are two views in cross-section of a form of construction of the gripping hand;

FIG. '3 is a plan view of the push-rod cage;

FIGS. 4 to 9 show diagrammatic views of the forwardmovement mechanism of the gripping hand;

FIGS. 10 and 11 are two views in cross-section of another form of construction of the gripping hand;

FIG. 12 is a plan view of the push-rod cage associated with the gripping hand;

FIG. 13 is a view in longitudinal section of a preferred form of construction of the device for the semi-continuous displacement of the machine;

FIGS. 14 to 18 show diagrammatic views of the forward movement mechanism of the machine, obtained by means of the device shown in FIG. 12;

FIG. 19 shows a form of construction of the gripping hand with hydraulic clamping;

FIGS. 20 and 21 give diagrammatic views of installations employing two gripping hands with hydraulic clamp- FIG. 22 shows a machine-towing installation-in which the longitudinal guide is associated with the conveyor along which the machine is moved;

FIG. 23 shows a machine-towing installation in which the longitudinal guide is associated with a supporting assembly;

FIGS. 24 and 25 show diagrammatic views of an alternative form of construction of the device shown in FIGS. 10, 11 and 12.

In the text which follows, there will be designated by non-accentuated letters all the movements taking place from the right-hand towards the left-hand of the drawings, and by accentuated letters all the movements taking place from the left towards the right.

The assembly 1, known in the text which follows as a gripping hand, consists essentially:

Of a gripping hand body 2, the transverse section of which has roughly the shape of a C;

Of a carrier bed 3, free in orthogonal translation but having its longitudinal translation movement limited in amplitude;

Of rollers 4;

Of a cage (see FIG. 3).

The body of the double-acting gripping hand 2 is coupled in translation to the body 6 of a hydraulic jack 7 (FIGS. 4 to 9), the piston 8 of which is rigidly fixed by means of the rod to the machine M to be displaced along a longitudinal guide 9.

The longitudinal guide of constant section, shown in the non-limitative form of a hollow cylindrical tube, is placed between the lower part 11 of the body of the gripping hand and the bed 3.

The lower part 11 of the body of the gripping hand cone stitutes what has been known as the lower jaw, while the bed 3 constitutes the upper jaw.

The lower face 12 of the upper part of the 'body of the gripping hand and the flat upper face of the bed, parallel to the face 12, form the so-called jamming faces.

The jamming face 12 is hollowed out with transverse imprints 13, each forming a portion 14 of a plane forming with the jamming face 15 a small angle, preferably about 12.

The jamming face 15 and each of the planes 14 form what has been known as a pair of secant planes; all the 6 pairs of secant planes 14-15 converge in the same direction f.

A roller 4 is placed in the hollow of each imprint 13. Its diameter is greater than the maximum distance h separating the face 15 from the face 12.

The cage 5 is provided with as many pairs of spring push-rods 16 as there are rollers, the push-rods being mounted in the cross-braces 17.

Each pair of push-rods 16 continuously urges a roller in the direction of convergence f of the pairs of planes 14-15.

The operation of the gripping hand is described below, it being understood that the starting position is the position of full jack extension (FIG. 4).

When the hydraulic pressure is applied to the jack in such manner that the jack 7 has a movement of withdrawal (FIGS. 4 to 7), or in other words in such manner that, when the jack body is stationary, the piston 8 has a tend ency to move in the direction of convergence of the pairs of planes 14-15, several movements take place.

(A) Locking period of the gripping hands Since the machine M is heavier than the gripping hand, it remains stationary and keeps the piston 8 stationary; the jack body 6 moves (arrow fmp) in the direction 0pposite to the direction of convergence f of the pairs of planes 14-15 and moves laterally the body of the gripping hand 1 (FIG. 5).

As this takes place, the rollers 4 separate the bed 3 from the upper part of the body of the gripping hand 2 by means of the inclined planes 14 until they are locked be tween the plane 14 and the lower face 15 of the bed 3 or, which comes to the same thing, cause the relative approach (arrows f FIG. 1) of the bed 3 (or upper jaw) and the lower jaw 11, until these two elements grip the guide-tube 9 without slipping.

(B) Forward movement period of the machine As the gripping hand is locked in translation on the guide tube 9, when the jack 7 continues its movement of withdrawal, the piston 8 displaces the machine M, through the intermediary of the rod 10 or driving member, in the direction of convergence 1 of the pairs of convergent planes 14-15 (FIG. 6, arrow F).

During this advance period, the machine M is displaced over a distance which is practically equal to the travel of the piston 8 of the jack (FIG. 7).

If the direction of application of the hydraulic pressure on the jack 7 is reversed (see FIG. 7) or in other words if the piston has a tendency to move in the direction opposite to the direction of convergence of the pairs of planes 14-15, there follows:

(C) The sliding period of the gripping hand or return period As the machine M is heavier than the gripping hand, the piston '8 remains stationary and the body of the jack 6 moves in the direction f that is to say in the direction of convergence 1 of the pairs of planes 14-15 (FIG. 7).

When this occurs, the jack body 6 drives the gripping hand body 1 in translation in the direction 1, at the same time releasing the rollers 4 and freeing the

jaws

11 and 3.

The gripping hand, free in translation with respect to the guide 9, moves with respect to this guide and to the machine M, remaining stationary, over a distance approximately equal to the travel d of the piston 8 (FIG. 9).

The device described thus carries out a discontinuous movement of translation of the machine in the direction (arrow F) of convergence of the pairs of planes 14-15, and over a length approximately equal to the travel of the piston. It is clear that reversal of the direction of application of the hydraulic pressure on the jack 7 between the forward-movement period and the return period on the one hand, and the return-period and the forwardmovement period on the other, must be efffiected automatically, for example by means of detectors (not shown) of the extreme positions of the piston '8 (end of extension and end of withdrawal), the said detectors controlling the operation of the hydraulic distributor 18 of the type having four ways and two positions of use.

In order to effect a discontinuous displacement of in one or the other of the two possible directions, there may be provided two gripping hands comprising pairs of planes converging in opposite directions 3 and f, everything else remaining unchanged, and one or the other of the jacks coupling the machine to each gripping hand, is put under pressure.

Also, as shown in FIGS. 10, 11 and 12, only one gripping hand may be installed.

In this case, the jamming face 12 is hollowed out with symmetrical transverse imprints 19 in the shape of a V with the point upwards, the push-rod cage being provided with pairs of push-rods 16, 16' acting in opposite directions 1, f.

The

planes

15 and 14 converge in the directions 1 and the

planes

15 and 14 converge in the direction f.

A selector device determines the direction of movement of the machine M by imposing the direction in which the rollers 4 are continuously urged.

In the form of embodiment shown in FIG. 10, the selector device is a pillar 20 rigidly fixed to the cage 5 and capable of assuming two positions fixed with respect to the body of the gripping hand, located on each side of the abutment constituted by the transverse lever 21 articulated on the body of the gripping hand, so that, for the fixed position 206 (see FIG. located to the left of the lever 21, the rollers 4 are urged in the direction of convergence 1 of the pairs of secant planes -14 and, for the other fixed position D (drawn in broken lines in FIG. 10) located on the right of the lever 21, the rollers 4 are urged in the direction j (opposite to j) of convergence of the pairs of secant planes 15-14'.

When the pillar 20 is in the position 20G, everything takes place as in the case of FIGS. 1 to 9, and the machine (not shown) is displaced in a discontinuous manner in the direction F.

When the pillar 20 is in the position 20D, all the movements are reversed and the machine is displaced in a discontinuous manner in the direction F opposite to F and to 1.

FIG. 13 shows a view in longitudinal section of a preferred form of construction of the device according to the invention.

This form of construction utilizes two gripping hands with a face 12 having transverse symmetrical imprints 19.

In the text which follows, the symbols of everything which is associated with the gripping hand 1G on the left-hand side looking on the drawing has been given the letter G, while the symbols of everything associated with the right-hand gripping hand looking on the drawing have been given the letter D.

In order to avoid overloading the drawings, the cages and the selector devices have not been shown, the force applied by the various push-rods being indicated symbolically by the arrows f6 and 7D.

Each

gripping hand body

1G, 1D is coupled for translation to the body 66, GB of a double-acting jack,

The pistons 86 and SD of the jacks are coupled together by a synchronizing rod 22, each piston being furthermore fixed on the machine M by means of the driving elements 106 and 10D.

Two

longitudinal channels

23 and 24 are pierced in the synchronizing rod 22 and in the pistons 8G and 8D. They are symmetrical with respect to the centre of the assembly 8G-22-8D, and open:

At their left-hand extremity, one on one side of the piston 86 and the other on the other side of the piston 8G.

At their right-hand extremity, one at one side of the piston 8D and the other at the other side of the piston 8D.

Two pulleys 25 and 26, the shafts of which are fixed on the body of the machine M, are mounted on each side of the assembly comprising the two

gripping hands

16 and 1D.

A endless chain 27 passes round the two pulleys, one of its straight sides being rigidly fixed on one of the jack bodies (point N6 of the body 66), while its other straight side is fixed to the other jack body (point ND of the body 6D).

Taking the foregoing into account, it can be seen that the shafts of the pulleys 25 and 26, the coupling elements 10G-10D, the pistons 8G-8D and the synchronizing rod 22 are rigidly fixed to the body of the machine M, while each jack body is coupled for translation to the body of a gripping hand.

The cages (not shown) of the two gripping hands are locked in the same position, which means that the pushrods (not shown) urge the rollers 4G and 4D in the same direction (arrows fG andfD).

In order to describe below the operation of the device, there will be taken as the starting position that which corresponds to the gripping hands as far separated from each other as possible (see FIG. 14).

When the hydraulic pressure is applied to the shortest longitudinal conduit (conduit 23), that is to say to the conduit which opens in the vicinity of the faces of the pistons opposite each other:

(A) The machine M being the heaviest part of the installation, first remains stationary and holds the pistons 8G and 8D and the rod 22 stationary; then, simultaneously (FIGS. 13 and 15):

(a) the jack body 66 moves towards the right (arrow j'mpg), that is to say in the direction opposite to the direction of action fg of the push-rods of the gripping hand 16; the hand 16 effects the locking period;

(b) the jack body 6D moves towards the left (arrow fmpd) under the simultaneous action of the hydraulic pressure and of the chain 27 (arrows fch and felt), this latter having a tendency to cause the points NG and ND to move together and therefore the bodies of the gripping

hands

1G and 1D; the rollers 4D are released and the hand 1D, free in translation, begins its return movement.

(B) As the hand 1G is locked by gripping one the guide-tube 9 (FIG. 16), it carries out the advance period, while the hand 1D continues its return period; the machine M and the hand ID are displaced in the same direction F.

When the pistons 8G and 8D have reached the limit of their travel, the machine M has been moved over a distance which is practically equal to the travel d of the pistons, while the hand 1D has been displaced over a distance equal, to within the clearances, to twice the travel of the pistons. The two hands 16 and ID are then in their closest positions (heavy lines for the gripping hand 1D).

(C) The reversal of the direction of action of the hydraulic pressure causes (FIG. 17):

(a) Simultaneously, the locking period of the hand 1D and the release of the jaws of the hand 16;

(h) Then, simultaneously, the advance period of the hand D, the return period of the hand G, and the progressive separation of the

hands

1G and 1D.

The machine M and the hand 1G are moved in the same direction F as previously, up to the end positions shown in heavy lines in FIG. 18, for which the various elements are again found in the relative position shown in FIG. 14.

The machine M has again been displaced over a distance substantially equal to d, and the hand 16 over a distance substantially equal to 2d.

It should be observed that, in addition to the synchronization of the movements of 1G and 1D, the chain 27 transmits to the jack body which effects the return period, the thrust applied by the jack controlling the ad- Vance period, which amounts to the same thing as saying that, in order to overcome a given force which opposes the movement of the machine, a thrust must be developed on the jack effecting the advance period, giving half the driving force necessary to overcome the resisting force.

It is clear that, all other things remaining the same, if the cages are locked in the other position, that is to say if the rollers are urged in directions opposite to fG and fD, the machine M is displaced in the same manner in the direction F, opposite to F.

It may furthermore be observed that in any of the forms of embodiment described, the locked gripping hand is provided with self-regulation of its clamping etfect on the guide-tube 9.

In fact, if the force developed by the jack is too great (see FIGS. 1 and 4 for example), the gripping hand assembly has a tendency to slip along the tube in the direction fmp opposite to the direction of movement F of the machine.

In such case, the body of the gripping hand 2 drives the rollers by friction in the direction 1, the rollers move up the sloping face formed by the planes 14, and there results an increase in the gripping force fs of the

jaws

3 and 11.

According to a further form of embodiment, the gripping hand is designed in an entirely hydraulic form.

FIG. 19 is a form of construction of the towing installation comprising a single gripping hand.

This latter form is distinguished from that shown in FIG. 1 by the fact that the approach movement of the

jaws

3 and 11 is effected by means of at least one singleacting jack placed between the upper jaw 13 and the body 2 of the gripping hand.

In FIG. 19, there can be seen three single-acting jacks 40, the pistons 41 of which come into contact with the body 2. In the description of this form of construction, the internal face 39 of the upper part of the gripping hand body on which the pistons of the single-acting jacks are supported, will be known as the clamping face.

These jacks are supplied from a source of pressure P1, which may furthermore be the pressure source P which supplies the double-acting jack 7 serving to drive the machine M, by means of the conduit 42 and the distributor 43 of the type having three ways and two positions.

The distributor 43 is advantageously operated hydraulically by the jack 7 by means of the distributor 44 of the type with four ways and two positions with manual control and

pilot conduits

45 and 46 connected in parallel with the

conduits

47 and 48 coupling the distributor 18 to the jack 7, in such manner that:

(I) For the position of the distributor 44 shown in FIG. 19:

(a) When the pressure P is applied to the conduit 47, the pressure P is simultaneously applied to the jacks 40 so as to cause the approach movement of the

jaws

3 and 11, from which follows the displacement of the machine in the direction F.

(b) When the pressure P is applied to the conduit 48, the jacks 40 are simultaneously put to the tank R and the

jaws

3 and 11 are released, from which follows the displacement of the gripping hand in the direction F.

(II) For the other position, not shown, of the distributor 44:

(c) The pressure P is applied to the jacks 40 when the pressure P is applied to the conduit 48, from which follows the displacement of the machine M in the opposite direction to F.

(d) The jacks 40 are connected to the tank R when the pressure P is applied to the conduit 47, from which results the displacement of the gripping hand in the direction opposite to F.

It can thus be seen that the manually-operated distributor 44 carries out the functions of an operation reversing :10 device, and corresponds to the selector device 20-21 shown in FIGS. 10 and 11.

FIG. 20 is a first form of embodiment of the towage installation comprising two synchronized gripping hands of the same kind as that shown in FIG. 13.

The gripping hand 1G is provided with single-acting jacks 406 and the gripping hand 1D is provided with single-acting jacks 40D.

The distributor 49 of the type with four ways and two positions is connected:

On the intake side to a source of pressure P and to a tank R On the utilization side, on the one hand to the jacks 40G by means of the conduit 42G, and on the other hand to the jacks 40D by means of the conduit 42D.

The jack 49 is hydraulically actuated by the combination of the

jacks

7G and 7D by means of the

conduits

45 and 46 and the distributor 44 of the manually controlled type with four ways and two positions, so that there is obtained one of the two following sequences:

(I) The distributor 44 being in the position shown in FIG. 20, there is obtained simultaneously:

Either P applied to the conduit 23;

P applied to the conduit 426 and to the jacks 40G;

The conduit 24 to the tank R;

The jacks 40D to the tank R resulting in the dis placement of the machine and the gripping hand 1]) in the direction F P applied to the conduit 24;

P applied to the conduit 42 D and to the jacks 401);

The conduit 23 to the tank R;

The jacks 40G to the tank R which results in displacement of the machine M and the gripping hand 1G in the direction F.

(II) When the distributor 44 is in the other position, not shown in FIG. 20, the reverse operation is obtained, from which follows the displacement of the machine in the direction opposite to the direction F. If it is possible to utilize the source of pressure P to supply the

jacks

40G and 40D, the hydraulic installation may take the form shown in FIG. 21 which, with respect to FIG. 13, only comprises the following additional elements:

The

pilot conduits

45 and 46;

The distributor 44 for reversing the direction of movement;

The

conduits

42G and 42D; and the

jacks

40G and 40D.

For the position of operation shown of the distributor 44, the single automatic actuation of the distributor 18 causes:

(a) Simultaneously, the application of pressure to the conduit 23, and to the jacks 40G and the connection to the tank R of the jacks 40D and the conduit 24, from which follows the displacement of the machine M and the gripping hand 1D in the direction F.

(b) Then, simultaneously, the application of pressure to the conduit 24 and to the jacks 40D, and the connection to the tank R of the jacks 40G and the conduit 23, which results in displacement of the machine M and the gripping hand 1G in the direction F.

For the other position of operation of the distributor 44, the displacement of the machine M and of first one and then the other gripping hand, is effected in the direction opposite to F.

In all the forms of embodiment, the forward movement period is carried out without any random pulsations due, for example, to the elasticity of a chain; the mechanical elements are thus placed in the best conditions of use.

At the moment of passage of the machine, it is essential that each element of the longitudinal guide should be held in a fixed position with respect to the cutting face.

In order to do this, it is only necessary for each element to be associated with any available bearing point at the cutting face.

Thus, each element may be associated with a pan of the armoured flexible conveyor 30, evacuating the products cut by the machine (see FIG. 22), the element being fixed to the outer side 31 of the pan by any means known per se, such as, for example, by bolting or welding.

According to an advantageous alternative form, each element is constituted by the protecting tube of the return side of the towing chain with which each pan of an armoured flexible conveyor, normally used as the sliding track of a winning machine of the plough type, is usually equipped.

According to another form of construction, each element may be fixed by any known means, on the main prop of a chock of stanchions forming part of a mine roof support assembly installed at the cutting face.

In FIG. 23, the means for fixing the longitudinal guide is shown, without this having any limitative nature, by an angle-iron 32, welded on the one hand to the longitudinal guide element and bolted on the other hand to the main prop 33 of the chock 34.

The installations shown in FIGS. 22 and 23 are readily adaptable to rise-workings by equipping them with known means for keeping the machine parallel to the ground, or alternatively for installing the conveyor horizontally.

It is clear that modifications and technological improvements could be made to the devices described purely by way of explanation and not in any way limitative sense, without thereby departing from the scope of the invention while remaining in conformity with its spirit.

Thus, the transverse imprints could be formed in the bed. This latter must be coupled in translation to the body of the jack, all other conditions remaining the same.

Modifications and improvements may also be applied to the means provided for continuously urging the rollers in the desired direction of convergence of the pairs of secant planes.

An alternative form of embodiment is shown in FIGS. 24 and 25. As can be seen from these figures, the imprints 19 have the form of a trapezoidal isosceles prism.

Two

rollers

4, 4 are installed in each imprint. A spring is inserted between the adjacent rollers. The springs 28 are inserted between the rollers 4 and 4' mounted in the imprints, while the springs 29 are inserted between the pairs of rollers.

The springs 28 have a tendency to apply the rollers 4 and 4' respectively against the inclined planes 14 and 14'.

The

springs

28 and 29 pass through the cross-braces 17 of the cage 5.

When the pillar 20 is in the position 206 (FIG. 24), the springs 29 urge the rollers 4 towards the left and cause them to leave contact with the planes 14.

The springs 28 are compressed and continuously apply the rollers 4 against the planes 14.

The active rollers are therefore the rollers 4 urged in the direction of convergence 1 of the pairs of secant planes 14-15. The machine (not shown) will be displaced in the direction F, coincident with f.

When the pillar 20 is in the position 29D, the springs 28 continuously apply the rollers 4' against the planes 14' and the machine will be displaced in the direction opposite to F.

The modifications may also be applied to the means for controlling the reversal of the position of operation of the hydraulic distributor 18, and which may be mechanical, hydraulic, electro-hydraulic or even electronic.

Finally it is clear that the methods according to the invention and also the devices for carrying these methods into effect are applicable to any type of mining machine, whether it is of the static-tool type (for example a plough) or of the type with active tools (for example a shearer),

the longitudinal guide have a constant section other than circular.

I claim:

1. A gripper for mining machine hauling apparatus including means for effecting relative movement between the gripper and a guide member, said guide member defining a generally rigid path of travel along which the hauling apparatus will be propelled, said gripper comprising in combination: a mining machine member, a pair of clamp assemblies each including a body having a piston chamber, said piston chambers being in a general axial alignment, jaw means on said bodies for releasably gripping the guide member,

said jaw means including directional-responsive actuating means for gripping and releasing said guide member in relation to relative movement of said bodies on said guide member,

a piston-and-rod means comprising an elongated rod terminally connected to said machine member and extending generally along the path of travel defined by said guide member,

said rod means extending axially through said piston chambers and including integral spaced piston respectively disposed in one of said piston chambers and defining variable-volume fluid chambers on opposite sides thereof, fluid pressure means connected to said variable volume chambers for optionally directing fluid pressure into the chambers to move the bodies relative to each other, with res ect to said guide member, and relative to said piston rod; and

synchronizing means connected between said bodies and said machine member for actuating said deactivating said directional-responsive actuating means.

2. The structure as claimed in claim 1 in which said synchronizing means comprises a pair of spaced pulley members journalled on said machine member for rotation on an axis transverse to the path of movement of said machine member,

an endless force transmitting member entrained over said pulleys and having opposite runs fixed to said clamp assembly bodies whereby movement of said machine member causes simultaneous movement of said clamp assembly body members.

3. The structure as claimed in claim 1 in which said jaw means, directional-responsive actuating means comprise alternately-controlled fluid-pressure operated clamping menas for urging said jaw means into clamped relation on said guide member.

4. The structure as claimed in claim 3 in which said synchronizing means comprises a pair of spaced pulley members journalled on said machine member for rotation on an axis transverse to the path of movement of said machine member,

5. The structure as claimed in claim 3 in which said bodies have a generally C-shape in end elevation and define upper and lower jaws for receiving the guide member transversely therebetween, one of said jaw members including a displaceable element engaging said guide member, and a plurality of fluid-pressure operated jack elements extending between said body and said displaceable element.

6. Structure as claimed in claim 1 in which said jaw means comprises a pair of spaced jaws, one of said jaws comprising a planar face, the other jaw comprising an angled cam face diverging toward said planar face, a casing displaceably mounted between said faces and having relative movement therebetween, said casing including roller means journalled in said casing and engageable with said cam face for being urged toward said planar face.

7. The structure as claimed in claim 6 in Which said bodies have a generally C-shape in end elevation and define upper and lower jaws for receiving the guide member transversely therebetween, the upper jaw including said cam face and the lower jaw including said planar face, said casing including cross bars extending generally in the same direction as said roller means, and means for selectively directing the roller means toward or away from said cam face.

18'. Structure as claimed in claim 6 in which said clamp assembly bodies are integral with the jaw including said cam face.

9. Structure as claimed in claim 8 including means normally urging said roller means toward said cam face.

10. The structure as claimed in claim 9 in which said cam face extends at an angle of about 12 with respect to said planar face. 1

References Cited UNITED STATES PATENTS ERNEST R. PURSER, Primary Examiner US. Cl. X.R.