US3220011A

US3220011A - Advance and position indicator for coal-cutter or like stoping machine

Info

Publication number: US3220011A
Application number: US317885A
Authority: US
Inventors: Fraisse George
Original assignee: Lorraine Houilleres
Current assignee: Houilleres du Bassin de Lorraine
Priority date: 1962-10-23
Filing date: 1963-10-22
Publication date: 1965-11-23
Anticipated expiration: 1982-11-23
Also published as: FR1361864A; DE1226971B; NL299550A; GB995210A

Description

3,220,01 1' CUTTER Nov. 23, 1965 G. FRAISSE ADVANCE AND POSITION INDICATOR FOR COAL- OR LIKE STOPING MACHINE 2 Sheets-Sheet 1 Filed Oct. 22, 1963 3,220,011 CUTTER G. FRAISSE Nov. 23, 1965 ADVANCE AND POSITION INDICATOR FOR COAL OR LIKE STOPING MACHINE 2 Sheets-Sheet 2 Filed 001:. 22. 1965 United States Patent 3,220,011 ADVANCE AND POSITION INDICATOR FOR COAL-CUTTER 0R LIKE STOPING MACHINE George Fraisse, Petite-Rosselle, Moselle, France, as-

signor to Houilleres du Bassin dc Lorraine, Moselle, France Filed Oct. 22, 1963, Ser. No. 317,885 Claims priority, application France, Oct. 23, 1962, 913,120, Patent 1,361,864 4 Claims. (Cl. 346-33) This invention relates to indicator means adapted for being employed with coal cutter machines or like stoping apparatus.

In mines, the progress made in operating methods depend upon the obtaining of accurate measurements. Thus, it became possible to develop the mechanization of mine workings by graphically establishing the working cycles of coal-cutters or stoping machines, by manually plotting, subsequent to timing, the displacement times of the coal-cutter. Such diagrams are complementary to the reports made by the supervising personnel and furnish the higher staif level not only with a synthesized insight into the rate of advance of a cutting face but also with elements of comparison between in dividual stations or individual mine workings. It might be added that, generally speaking, such diagrams facilitate work programming at a cutting face and enable the supervising personnel to make a quantitative estimate of the magnitude of possible incidents and an objective assessment of the effect of a poor operating method, from one station to the other.

This manual method, however, has its limitations as well as numerous drawbacks. The timing procedures are inevitably hasty and improvised to some extent and are concerned only with the arrival and departure of the coal-cutter at the ends of the cutting face and with important incidents, such as those entailing stoppages of over five minutes. This method, furthermore, leads to the timing operation being entrusted either to the foreman at the cutting face, thereby further burdening his tasks, or to a full-time time-study man, thereby increasing the labor strength. To this can be added the inaccuracies and inadequacies inherent in the method, which stem from the time-study mans aptitudes and behavior alike. Finally, the diagram is not obtained forthwith but must be established a posteriori.

With a view to overcoming these inadequacies and drawbacks and automatically recording the travel of the coal-cutter or stoping machine in terms of time at a point remote from the working and particularly from the office of the engineer in charge of operating the coal face, the present invention has for its object to provide a rate-of-advance recorder for a coal-cutter or like stoping machine with advance and position indicator, characterized in that its comprises, on the one hand, an underground selective generator of electrical pulses corresponding respectively to a determinate amount of travel of the coal-cutter during its forward and reverse motions and, on the other hand, a surface recorder having a drum which is rotated at uniform speed and associated with a stylus moved longitudinally of itself by a worm gear which is rotated step by step in one direction or the other by a selective pulse receiver.

Such advance and position indicator apparatus acts as an integrator of electrical pulses emitted at a frequency proportional to the speed of the coal-cutter, and enables the obtaining of a complete harmonogram of the rate of advance on the cutting face for twenty-four hours. It enables all movement of the coal-cutter in the mine working to be followed visually at all times Patented Nov. 23, 1965 'ice while a graphical representation of the work is obtained immediately, at the same time. The apparatus also provides continuous, full and objective observation of the rate of advance of the mechanized cutting faces and enables obtaining a solution to many problems which have hitherto remained obscure for lack of precise or systematic information.

The description which follows with reference to the accompanying drawings, which are filed by way of nonlimitative examples, will give a clear understanding of how the invention can be carried into practice and will disclose still further particularities thereof.

Referring to the drawings filed herewith:

FIGURE 1 shows schematically the selective pulse generator of the indicator apparatus according to this invention;

FIGURE 2 shows in perspective the worm gear, the stylus, and the recording drum;

FIGURE 3 is an overall circuit diagram; and

FIGURE 4 shows a graph obtained with the indicator apparatus according to the present invention.

Referring first to FIGURE 1, the selective pulse generator shown thereon comprises a cam 1 having lobes 2 mutually spaced at equal angular distances. Said cam is mounted concentrically on a driving sprocket wheel 3 of the winch that meshes with the chain 4 stretched along the length of the conveyor and enables the machine to be displaced. As the whole assembly rotates, the lobes 2 of cam 1 coact with one of the ends 5 of a lever 6 which is fulcrumed about a vertical shaft 7 and the other end 8 of which is adapted to actuate one of two .pushbuttons or selector contacts 9 9,. The shape of the end 5 of lever 6 is so determined that each lobe 2 causes said lever to tilt towards that pushbutton which corresponds to the direction of travel of the coal-cutter and at the same time permits escapement of that particular lobe with respect to the lever end. If the coal-cutter moves in the direction of arrow P in the coal-cutting process and in the direction of arrow F during the return phase, then selector contact 9,. will sustain the pressures of lever 6 during the return phase, as shown in the figure, whereas selector contact 9 will sustain the pressures of lever 6 during the coal-cutting phase. This assembly could be disposed underneath the standard protective enclosure provided for the bosses.

The electrical pulses generated by the successive pressures of lever 6 on one of selector contacts 9 9, for a specific work phase and the number of which is proportional to the distance travelled by the coal-cutter, are conveyed up to the surface by a telephone network 11 (FIGURE 3) and reach the indicator proper. The latter consists of a drum 12 rotated uniformly about its shaft by a clockwork mechanism (not shown), whereby to furnish a time scale. Said drum is provided with a graph-paper support 13 upon which bears a stylus 14 rigid with a nut 15 cooperating with an endless screw 16 in such manner as to be translated by rotation of said screw. Each electrical pulse delivered by the coalcutter energizes an

electrical actuating relay

17, or 17,- which causes the endless screw to rotate in response to the thrust of a

pawl

18,, or 18 against one of two op positely toothed ratchet wheels 19 19 supported by said endless screw, whereby to rotate the latter by a fraction of a revolution that is function of the number of teeth on

ratchet Wheels

19 and 19,. Thus, displacement of nut 15 faithfully follows the advance of the machine, while motion of the stylus 14 on the graph support 13, which stems from the composition of the motion of nut 15 and the rotation of drum 12, enables the space-time graph of the motion of the coal-cutter to be obtained.

In order to enable the pulses to be transmitted from the coal-cutter to the indicator, a junction box 2% is connected past the selector contacts 9 and 9 This box comprises a rectifier Ell interposed between one of the poles 22 of a source S of low-voltage (24 volts, say) electric current and one of the fixed contact studs of the selec tor contacts. The other pole 23 of said source is con nected to each of the other fixed contact studs of selector contacts 9, and fi via servo-control relays 2 t and 24-, which, when energized, are adapted to close two normallyopen contacts 25 and 25,. One of the fixed contact studs of said contacts is connected through a rectifier 25 to one of the poles of a second low-voltage source of electric current, while their other studs are connected to the other pole of the latter-mentioned source, as will be described hereinafter. The assembly 27, consisting of relays M 24,, rectifier 26, and contacts 25 25,, forms a servocontrol box for the direction of travel of the coal-cutter. The source S, the relays 24 2d,, the rectifier 21 and the selector contacts 9 9 form an intrinsic safety circuit.

The second source of low-voltage current consists of a transformer the primary winding 28 of which is connected, for example, to a 220 v. grid and the secondary winding 29 of which delivers 24 v. for example. One of the extremities of the secondary winding is on the one hand grounded through fuse 30 and, on the other, connected to rectifier 26 as well as to one of the studs of two normallyopen contacts 31 and 31,. of control relays 32,, and 32,. The other extremity of secondary winding 29 is connected via control relays 32 and 32 to the other studs of contacts 25 and 25,. It additionally supplies the actuating

relays

17 and 17 which are connected to the other studs of contacts 31 and 31, through normally closed limit contacts 33 33, and normally-closed locking contacts 3% and 34,.

The apparatus hereinbefore described functions in the following manner:

If the coal-cutter is considered during the return or loading phase, selector contact 9 is closed, thereby energizing servo-control relay 2d, and closing its contact 25,. The servo-control box 27 does then indeed fulfill its function, since it servo-controls the whole to the return channel. On closure of contact 25,, control relay 32,. is energized, thereby simultaneously closing its contact 3l and opening locking contact 34 whereby to ensure that only actuating relay 17 is energized. The pawl 1d then drivingly engages with ratchet wheel 1% to move the nut 15 in the direction of arrow f (see FIGURES 2 and 3). When it reaches the end of its return path, the nut operates on limit contact 33,, thereby deenergizing relay 17,.

In one possible embodiment, cam it has four lobes, while driving sprocket 3 has seven cogs and meshes with a marine-type chain having a pitch of 0.128 metre; each pulse consequently corresponds to a displacement of the coal-cutter through 0.224 metre. Each ratchet wheel 19 has twelve teeth, the scale chosen for the graph is one millimetre per metre and one millimetre for two minutes, which means that the endless screw 16 will have a pitch of 2.688 mm.

FIGURE 4 shows one of the graphs obtained with the apparatus hereinbefore specified. This graph provides instant detection of all incidents occurring during operation of the coal-cutter. Thus it may be seen that during the first coal-cutting and return phase, at a a large block has become jammed during the outfall, at b a slow-down has been introduced by an overhang, at c the precutting arm has become jammed, at d the stop at the loading point has occurred followed by an overhang blasting, at e and at f the machine has been raised for cleaning prior to scraping, following which scraping was effected at g. During the second cutting and return phase, at h the drum became jammed in the face, at i the machine was halted because of an overhang, at j the overhang was blasted and the timbering transported and at k the scraping and timbering were carried out. During the third cutting and return phase, at I there was a change of crew, at m a halt for haulage and at n scraping and timbering. Lastly, during the fourth cutting and return phase, at 0 the precutting arm became jammed, at p several falls from an overhang caused numerous jammings of the machine, while at q the overhang fell. There was no material to convey over the return path.

Such an indicator now makes it possible, in mining operations, to immediately determine a theoretical cycle of maximum daily advance for a given material and seam, thereby permitting optimum programming of the timbering or stowing cycles. It additionally enables coal-cutter picks to be evaluated and the optimum frequency of their replacement to be determined. Similarly, to achieve an integral coal-cutting operation, the recording of a series of tests will bring out, through a comparative study of the graphs, the most advantageous characteristics, from the standpoints for instance of length, depthwise position, and number of heads on the precutting arm which is mounted on the stoping machine, more particularly for breaking up dangerous overhangs that might remain attached to the roof subsequent to passage of the principal drum. Lastly, it is also possible to observe the behavior of the loading shoes in terms of evacuation of the fines, to detect the hard zones and note the effect of concussion blasts or of injecting water into the mass, and finally to note what difficulties are encountered in handling the material in the mine working as a function of the seam openings.

In addition to starting and end-of-station times, the apparatus enables all stoppages of the coal-cutter or the stoping machine to be recorded. Thus, for example, if the subject apparatus of the present invention is combined with a conveyor travel recorder, it can be established to what extent the work which has been or is to be carried out at a cutting face is governed by the haulage effected by the conveyor. Finally, this invention enables repetitive incidents at a cutting face to be detected and the lay-up times to be thereby reduced by precise and continuous monitoring.

What I claim is:

l. An advance and position indicator for coal-cutters of the type having a winch provided with a driving sprocket wheel which, for displacing the coal cutter, engages a stationary chain disposed along the length of an associated conveyor to be loaded by the coal-cutter, said recorder comprising a source of current at ground level, two normally open underground selector contacts connected to said source, means connected to the driving sprocket wheel of the coal-cutter for closing a respective one of said contacts for a determinate displacement of the coal-cutter during opposite strokes thereof corresponding to cutting and return motion, to generate selective electrical pulses, means for conveying said pulses to ground level, a recorder at ground level including a rotary drum with an axis and a stylus at right angles to the axis of said drum and displaceable parallel to said axis, means for rotating said drum at uniform speed, means for step by step displacing said stylus parallel to said axis in opposite directions, and selective pulse receiving means interconnecting the conveying means and the step by step displacing means for controlling the displacement of said stylus in relation to those of said coal-cutter during its cutting and return motion, respectively, said means for the step by step displacing of the stylus comprising a nut rigid with the stylus, an endless screw parallel to the drum axis and engaging said nut, and means interconnecting said selective pulse receiving means and said endless screw for rotating said screw step by step in respective opposite directions, the latter means comprising two oppositely toothed ratchet wheels respectively mounted on the extremities of said screw, two actuating relays connected to the selective pulse receiving means respectively energized by the pulses generated during the cutting and return motion of the coal-cutter, and two pawls respectively controlled by said relays for respectively engaging said ratchet wheels, said selective pulse receiving means comprising a second source of current one pole of which is connected to one end of the actuating relays, two control relays interconnecting said one pole of said second source and the means for conveying the pulses, said control relays having normally open contacts connected to the other pole of said second source, two normally closed limit contacts respectively connected to the other end of said actuating relays and adapted to be opened by the nut when said nut reaches the ends of its path, and two normally closed locking contacts respectively interconnecting said limit contacts and the contacts of said control relays, each one of said locking contacts being opened when the control relay the contact of which is not connected to it is energized.

2. An indicator according to claim 1, wherein the second source of current comprises the secondary winding of a transformer having a primary winding which is connected to a grid.

3. An indicator according to claim 1, wherein the means for conveying the pulses to ground level comprises a telephone link connecting the control relays of the surface selective pulse receiving means and the underground selector contacts.

4. An indicator according to claim 1, wherein the telephone link comprises a junction box having a rectifier in terconnecting one pole of the first source of current and the selector contacts, and a direction-of-travel servo-control box comprising two servo-control relays respectively interconnecting the other pole of said first source of current and the selector contacts and the contacts of which are normally open and connected to the control relays of the selective pulse receiving means, and a second rectifier interconnecting the other pole of the second source of current and the contacts of said servo-control relays.

References Cited by the Examiner UNITED STATES PATENTS 880,592 3/1908 Sterling 34633 938,516 11/1909 Russell 346-138 X 2,326,219 8/1943 Hayward 346-33 X 2,390,178 12/1945 Rutherford 34630 2,628,498 2/1953 Smith. 3,009,355 11/1961 Abs et al. 346-33 X LEO SMILOW, Primary Examiner.

Claims

1. AN ADVANCE AND POSITION INDICATOR FOR COAL-CUTTERS OF THE TYPE HAVING A WINCH PROVIDED WITH A DRIVING SPROCKET WHEEL WHICH, FOR DISPLACING THE COAL CUTTER, ENGAGES A STATIONARY CHAIN DISPOSED ALONG THE LENGTH OF AN ASSOCIATED CONVEYOR TO BE LOADED BY THE COAL-CUTTER, SAID RECORDER COMPRISING A SOURCE OF CURRENT AT GROUND LEVEL, TWO NORMALLY OPEN UNDERGROUND SELECTOR CONTACTS CONNECTED TO SAID SOURCE, MEANS CONNECTED TO THE DRIVING SPROCKET WHEEL OF THE COAL-CUTTER FOR CLOSING A RESPECTIVE ONE OF SAID CONTACTS FOR A DETERMINATE DISPLACEMENT OF THE COAL-CUTTER DURING OPPOSITE STROKES THEREOF CORRESPONDING TO CUTTING AND RETURN MOTION, TO GENERATE SELECTIVE ELECTRICAL PULSES, MEANS FOR CONVEYING SAID PULSES TO GROUND LEVEL, A RECORDER AT GROUND LEVEL INCLUDING A ROTARY DRUM WITH AN AXIS AND A STYLUS AT RIGHT ANGLES TO THE AXIS OF SAID DRUM AND DISPLACEABLE PARALLEL TO SAID AXIS, MEANS FOR ROTATING SAID DRUM AT UNIFORM SPEED, MEANS FOR STEP BY STEP DISPLACING SAID STYLUS PARALLEL TO SAID AXIS IN OPPOSITE DIRECTIONS, AND SELECTIVE PULSE RECEIVING MEANS INTERCONNECTING THE CONVEYING MEANS AND THE STEP BY STEP DISPLACING MEANS FOR CONTROLLING THE DISPLACEMENT OF SAID STYLUS IN RELATION TO THOSE OF SAID COAL-CUTTER DURING ITS CUTTING AND RETURN MOTION, RESPECTIVELY, SAID MEANS FOR THE STEP BY STEP DISPLACING OF THE STYLUS COMPRISING A NUT RIGID WITH THE STYLUS, AN ENDLESS SCREW PARALLEL TO THE DRUM AXIS AND ENGAGING SAID NUT, AND MEANS INTERCONNECTING SAID SELECTIVE PULSE RECEIVING MEANS AND SAID ENDLESS SCREW FOR ROTATING SAID SCREW STEP BY STEP IN RESPECTIVE OPPOSITE DIRECTIONS, THE LATTER MEANS COMPRISING TWO OPPOSITELY TOOTHED RATCHET WHEELS RESPECTIVELY MOUNTED ON THE EXTREMITIES OF SAID SCREW, TWO ACTUATING RELAYS CONNECTED TO THE SELECTIVE PULSE RECEIVING MEANS RESPECTIVELY ENERGIZED BY THE PULSES GENERATED DURING THE CUTTING AND RETURN MOTION OF THE COAL-CUTTER, AND TWO PAWLS RESPECTIVELY CONTROLLED BY SAID RELAYS FOR RESPECTIVELY ENGAGING SAID RATCHET WHEELS, SAID SELECTIVE PULSE RECEIVING MEANS COMPRISING A SECOND SOURCE OF CURRENT ONE POLE OF WHICH IS CONNECTED TO ONE END OF THE ACTUATING RELAYS, TWO CONTROL RELAYS INTERCONNECTING SAID ONE POLE OF SAID SECOND SOURCE AND THE MEANS FOR CONVEYING THE PULSES, SAID CONTROL RELAYS HAVING NORMALLY OPEN CONTACTS CONNECTED TO THE OTHER POLE OF SAID SECOND SOURCE, TWO NORMALLY CLOSED LIMIT CONTACTS RESPECTIVELY CONNECTED TO THE OTHER END OF SAID ACTUATING RELAYS AND ADAPTED TO BE OPENED BY THE NUT WHEN SAID NUT REACHES THE ENDS OF ITS PATH, AND TWO NORMALLY CLOSED LOCKING CONTACTS RESPECTIVELY INTERCONNECTING SAID LIMIT CONTACTS AND THE CONTACTS OF SAID CONTROL RELAYS, EACH ONE OF SAID LOCKING CONTACTS BEING OPENED WHEN THE CONTROL RELAY THE CONTACT OF WHICH IS NOT CONNECTED TO IT IS ENERGIZED.