US3372397A - Travel recording apparatus for coal cutters or other mining machines - Google Patents

Description

March 5, 1968 P TRAVEL RECORDI ERS OR OTHER MINING MACHINES 5 Sheets-Sheet 1 Filed Sept. 22, 1965 w WM m f m 5 a M w 4 @m H i 0 5 m A B p a R M 6 Z M w dd Av 1 m w 7 w e l 0 F W N K Qn/W/I /|WW A B m w v m D M 5 Z 57 WW 5 m i3 5w March 5, 1968 P. L. J. TISON 3,372,397

TRAVEL RECORDING APPARATUS FOR COAL CUTTERS 1 OR OTHER MINING MACHINES Filed Sept. 22, 1965 3 Sheets-Sheet 2 v I I I I M40075 6/7965 g 1x765 I 3 827065 fl rzoaqavr am fZifiEf QJ* v A5. 01 I I g I 3/I I I 579 65! n //V// {if/($09776! /I/ $701,962 M I I I I I I .32 34 I I I I I I I I I I I I I I I I I United States Patent Qfifrce 3,372,397 TRAVEL RECORDING APPARATUS FOR COAL CUTTERS OR OTHER MINING MACHINES Pierre Louis Joseph Tison, Saint-Avoid, Moselle, France,

assignor to Houilleres du Bassin de Lorraine, Merlebach, Moselle, France Filed Sept. 22, 1965, Ser. No. 489,351 Claims priority, application France, Sept. 25, 1964, 989,354, Patent 86,439 6 Claims. (Cl. 346-33) ABSTRACT OF THE DISCLOSURE Travel recording apparatus for coal cutters or other mining machines, comprising a pulse generator incorporated in the coal cutter and generating two bits of logic initial information the values of which are a function of the position of the rotating shaft on the winch which is mechanically interconnected with the chain used to haul the coal cutter, and, above ground, a transit detector which receives these initial bits of information and delivers an addition or subtraction pulse according thereto, and a recording unit operated by said addition and subtraction pulses.

In U.S. patent application Ser. No. 317,885, filed Oct. 22, 1963, now Patent No. 3,220,011, there was described a travel recording apparatus for coal cutters or other mining machines, comprising on the one hand a selective generator of electrical pulses each corresponding to a determinate forward or backward displacement of the coal cutter and, on the other hand, a drum-type recorder positively rotated at uniform speed and associated to a stylus moved longitudinally of itself by a worm gear which is rotated stepwise in one direction or the other by a selective transducer receiving said pulses which is located above ground together with said recorder and which is connected by a telephone link to the selective pulse generator, the latter being positioned on the coal cutter in the gallery being worked.

Such apparatus may in certain cases furnish a recording containing undetectable errors due to such undesirable pulses as may occur through bouncing of the selector contact points of the pulse generator when they are contacted by the contact studs rigid with the coal-cutter winch driving sprocket, or when they leave said contact studs.

The present invention has for its object to overcome these disadvantages and accordingly relates to improvements made to said apparatus, to the remote transmission of information from the mine gallery to the surface, and to the surface recording unit.

It is accordingly the object of the invention to provide a travel recording apparatus for coal cutters or other mining machines, comprising a pulse generator incorporated in the coal cutter and generating two pieces of logic initial information (hereinafter referred to as informations) the values of which are a function of the position of the rotating shaft on the winch which is mechanically interconnected with the chain used to haul the coal cutter, and, above ground, a transit detector which receives these initial logic informations and delivers an addition or subtraction pulse according to whether the information sequence it receives between two informations of absence of both initial informations contains in a given order or in the reverse order information indicating the presence of one initial information and the absence of the other initial information, and vice versa, and a recording unit operated by said addition and subtraction pulses.

The pulse generator may consist either of a dynamic type device such as a plate mounted on the winch shaft 3,372,397 Patented Mar. 5, 1968 and equipped with a set of protruding cams adapted to close a pair of contact points as they transit past the same, or of a static type device such as a pair of transit detectors utilizing a photoelectric cell, a pair of slot type detectors employing any convenient system such as the coupling of a resonant circuit or flux variations in a coil, or else two short-detectiomrange type detectors of the presence of a conducting mass.

The logic informations furnished by the two detectors indicate whether detection has been effected or not, and the values of these informations are respectively 1 and 0 in accordance with functional logic practice. Preferably, the reference pair of logic informations is taken as ()0.

The transit detector preferably comprises conventional combinative pulse-emitting output circuits, and input circuits for receiving logic information indicative of sequence inputs or outputs and for delivering a signal for the two pairs of informations corresponding to the two determinate states of the coal cutter, said circuits being connected through gates to storages for storing the initial appearance of the pairs of informations corresponding to said two determinate states, a storage for storing the sequence of said initial appearances and a functional time-delaying operator for zeroing these storages upon the appearance of the pair of reference informations.

Preferably, the recording unit comprises an adder-subtractor which receives the pulses from the transit detector and is connected to a recorder through a digital-analog converter.

The description which follows with reference to the accompanying non-limitative exemplary drawings will give a clear understanding of how the invention can be carried into practice.

In the drawings,

FIG. 1 shows a first form of the embodiment of a pulse generator according to the invention;

FIG. 2 shows the pair of logic information signal trains furnished by the generator of FIG. 1;

FIGS. 3, 4 and 5 show diagrammatically three other forms of the embodiment of a pulse generator according to the invention;

FIG. 6 is a block the invention;

FIG. 7 is a detailed block diagram of the information processing unit;

FIG. 8 shows the circuit diagram of a transit detector furnishing a pulse for a given direction of rotation of the coal-cutter winch shaft;

FIG. 9 shows the circuit diagram of a transit detector furnishing two pulses corresponding to the two directions of rotation of the coal-cutter winch shaft, respectively;

FIG. 10 is a block diagram of a digital-analog converter usable in the apparatus according to the invention;

FIG. 11 is a block diagram similar to that of FIG. 6, comprising functional elements for permitting operation of the apparatus in the event of a failure in the mains pp y;

FIG. 12 is a block diagram similar to the preceding ones but embodying a special feature; and

FIG. 13 is a schematic illustration of a selsyn-type inching motor usable in the apparatus according to the invention.

Referring first to the form of embodiment shown in FIG. 1, the pulse generator shown thereon consists of a plate 1 having a plurality of protruding cams 2 along its periphery, for example three cams as shown in FIG. 1. Plate 1 is keyed to the shaft 3 of the coal-cutter winch, the drive sprocket of which meshes with the hauling chain stretched along the length of the conveyor whereby to displace the coal cutter. Said plate cooperates with two cam followers 4 and 5 which close two contact points diagram of the apparatus according to points 4 and 5, respectively, afunction of the position of shaft'3. With the followers When they engage with one of the cams 2 and open these points when they ride off the cam.

The pulses thereby obtained at each third of a revolution of the .plate are used to produce two logic informations A and'B corresponding tothe pulses from contact and the values of which are 4 and positioned between two cams 2, then if shaft 3 drives the plate 1 in the direction of the arrow F the logic informations A and B will take the sequence of values 00 01 11 l0 ()0 until'thesefollowers are positioned in the gap between the next two cams 2. If shaft rotates in the opposite direction, then the informations A and'B will take the sequence of values 00 ()1 11 01 00. Thus a characteristic sequence is obtained for each third of a reovlution of shaft 3. Should it be desired to increase the degree of accuracy, then the number of cams 2 carried by-plate 1 may be increased.

The logic informations A and B are dispatched-above ground in the form of overlapping signal trains, as shown in FIG. 2 in which the lower train corresponds to logic information A and the upper train to logic information B. The informations A and B delivered thus represent the rotations of the drive shaft to within a fraction of a revolution and permit of reconstituting, above ground, the direction of travel of the coal cutter and of generating addition or subtraction pulses in numbers-proportional to the numberof rotations of the shaft 3,-i.e. to the displacement of the coal cutter.

Instead of utilizing a pulse generator based on a dynamic action of the rotating compound, recourse may be had alternatively to a pulse generator based solely on a static action of said compound, without contact with the pulse generating members. Thus, as shown in FIG. 3, theplate la mounted on shaft 3 is formed with two peripheral lobes 6 and 7 adapted to cause two photoelectric cells 8 and 9 to be illuminated by two light sources 10 and 11, whereby either of the two precedingly indicated sequences may be obtained depending on the direction of rotation of shaft 3.

Reference is next had to FIG. 4, in which the plate 1b driven by shaft 3 carries a protruding peripheral member 12 cooperating with a member 13, without contact therewith, whereby to utilize any convenient principle such as the coupling of a resonant circuit or flux variations in a coil.

Alternatively, recourse may be had to a detector of the .presence of a conductive mass as exemplified by the detector shown in FIG. 5, in which the plate 1c driven by shaft 3 carries a protruding peripheral conductive mass 14 which transits before two conductive mass detectors 15 and 16 having a short detection range.-lVIanifestly, in the case of FIGS. 3, 4 and 5, thepair of apertures 6, 7 or the elements 12. or 14 could be provided in any convenient number along the plate periphery.

The logic informations A and'B generated at the cuttingface by means of the sensor 17 on the coal cutter, consisting of any one of the devices shown in FIGS. 1, 3; 4 or 5, are dispatched above ground by any convenient remote transmission system 18, examples being of the wire-to-wire, coded digital, or multiplexed or non-multiplexed characteristic frequency type, via a transmitter 13 (see FIG. 6). There is thus made available above ground,

at the output of a transducer 20 of a type adapted to the .kind of remote transmission employed, the two logic functions A and B under any convenient form (contacts, levels, voltages). These logic informations A and B are then transmitted to a unit 21 for processing the information.

As shown in the block diagram of FIG. 7, the unit 21 consists of a transit detector 22 emitting addition pulses C and subtraction pulses D which are transmitted to an adder-su-bstractor 23 which operates the recorder 25 through the medium of a digital-analog converter such as the. decoder 24.

Provided that the state of the adder-subtractor is known when the coal cutter or other machine under control is at a given point on the job-site, then its aggregate reading will make it possible to know the position of the machine at any given instant to within a fraction of a revolution of the drive shaft-3. It is, however, imperative to avoid counting errors, with the generation of addition and subtraction pulsesa general problem associated with sequential automation devices-being achieved as indicated hereinbelow by means of the-transit detectors of FIGS. 8 and 9, and with due note being taken of the following remarks.

Addition and subtraction pulses must be generated only when either of the aforementioned two sequences relevant to the logic informations A and B have occurred, care being taken to prevent a pulse from being produced when none should occur, as for instance in the event of an abnormal sequence such as a sequence embodying a repetition of informatiomsince this would lead to functional errors in the system. Considering the two sequences 00 01 1110 '00 and 00 10 ll 01 '00, it can be seenthat they are characterized by the fact that the states 01 and 10 occur in a certain order, which is the designprinciple used for a transit detector. When the reference state 00 is reached after having started from that same reference state 00, the transit detector must produce an addition pulse C if 01 and 10 have been obtained in that order, or a subtraction pulse D if 10 and 01 have been obtained in that order, or a single pulse C if an abnormal sequence such as 00 01 ll 01 11 1O 00 is obtained.

'It should be remembered that in functional logic the notation A indicates the absence of state A.

FIG. 8 illustrates by way of example the design of a transit detector utilizing the above principle for delivering solely addition pulses C.

The transit detector shown in FIG. 8 comprises a first stage consisting of AND logic circuits 26 through 28, of which the first, 26, receives the logic informations A'B for generating level 01, the second, 27, the logic informations AB for generating level 10 and the third, 28, thevlogic informations A'B for generating reference level 00. The signal 01 passes through an open gate located in-a second stage and consisting of an AND logic circuit 29 the signal from which blocks, in a third stage, a storage 30 for storing the initial appearance of level 01, which storage is connected in a fourth stage to an AND logic circuit 31 delivering the addition pulses C. Connected into the third stage is. a storage 32 for storing the initial appearance of level .10 and a sequence, storage 33 which is connected to storages 3G and 32 and which is blocked by whichever of stages 01 or 10 is reached first. The storage-for the initial appearance of level 10, connected to gate 29, closes the latter if level 10 is reached before level 01, whereby the addition pulse C can be emitted onappearance of level 00 at the output from circuit 28 only provided that level 01 appears before level 10, in which case an output pulse, namely an addition pulse C,-will be delivered by circuit 31 on appearance of said level 00.

The storages 30, 32 and 33 are zeroed by the appearance of level ()0, but in order that the output pulse C from circuit 31 should not be fugitive, the zeroing is timedelayed by a delay system 34 connected into the second stage and delivering to said storages a 00 signal which-is time-delayed with respect to the instant .when the reference state signal 00 appears.

The transit detector of FIG. 9 differs from that of FIG. 8 in that it is capable of delivering addition pulses C and subtraction pulses D. In addition to having identical components to those of the detector of FIG. 8 (designated by like ref rence numerals followed by the suffix a), the detector of FIG. 9 includes a second gate 35 in the second stage consisting of an AND-circuit which is connected to the circuit 27a delivering level 10 and to the storage 32a for storing .the initial appearance .of that level 10. Further, an AND-circuit 36 in the fourth stage is connected to storage 32a and, like the circuit 31a in the fourth stage, to the sequence storage 33 and to the circuit 28a for generating the level 00. In this detector, the gate 35 performs the same function in respect to the level 10 as the gate 29a to the level 01. As a result, an addition pulse C is obtained when the sequence 01 00 occurs, and a subtraction pulse D when a sequence 00 10 01 00' occurs, and the terms in the sequence included between 01 and 10 may involve a repetition of these two levels.

The addition and subtraction pulses C and D are transmitted from the transit detector to the adder-subtractor 23, which enables the position of the machine or coal cutter to be known from the aggregate reading it gives. In order that this position may be plotted graphically against time, the number recorded is converted into a continuous quantity by means of a digital-analog converter 24 the output of which is connected to the input of a suitable recorder 25, which recorder will be of the potentiometric type if the analog data take the form of voltages, or of the galvanometric type if they take the form of current intensities for example.

The analog data can be obtained by direct decoding by utilizing the system shown in FIG. 10, in which an inching motor 37, which receives the addition pulses C and subtraction pulses D, actuates a potentiometer 38 which operates as a rotation decoder and activates the recorder 25.

The recorder 25 may embody special features such as a reserve of operation, automatic paper windback, or a graduated scale to permit ready removal of a recording which is under way.

The gain of the digital-analog converter can be made variable to enable the recorder scale to be matched to the length of the back-and-forth movement of the coal cutter and make allowance for changes in pitch resulting from the continual elongation of the hauling chains, for different numbers of teeth on the drive sprocket, different chain pitches, the variety of possible mining machines, and the different possible lengths of the job-sites.

In the event of a failure in the power supply above ground, the subject apparatus of the invention can be maintained in operation by using a buffer battery 39 (see FIG. 11) for powering the data processing unit comprising the transit detector generating the addition and subtraction pulses, the adder-subtractor, and the digitalanalog converter, the recorder itself incorporating an electrical or mechanical reserve drive 40. Should no buffer battery be available, the adder-subtractor can be caused to trip out when the current fails and to set off an alarm device when current is restored. The adder-subtractor must be capable of being readily zeroed manually at any time and of being preset at any possible value before the apparatus is placed in service.

The system can be further improved by prohibiting the recording of negative numbers when the machine on the job-site reaches a limit position that is caused to correspond to zero on the adder-subtractor, in which case the latter will be associated to a zero sensor 41, as shown in FIG. 12.

The information processing unit may alternatively consist of a selsyn-type inching motor drivingly connected to a potentiometer (see FIG. 13). Such a motor may comprise a permanent magnet 42 positioned in the field generated by two overlapping windings 43, 44 which receive the logic informations A and B respectively. The field directions corresponding to the states 00; 01, 11 and 10 of the variables A and B will differ from one another by 90.

The rotor consisting of the permanent magnet 42 drives the shaft of the circular potentiometer, and the buffer battery can be dispensed with. The voltage supplied to the potentiometer can be made adjustable in order to allow for the chain length and cutting distance.

Further, the headquarter premises of mining undertakings usually dispose of several simultaneously operating, coal-cutter position remote recording systems, in which case the corresponding pieces of apparatus may be grouped together above ground, with each machine having its own transit detectors and adder-subtractor; in that case a single digital-analog converter would be utilized and be operated cyclically in particular in respect of each coal cutter. The corresponding recorders may be of the single track type, or may have multiple tracks and thereby enable the positions of several coal cutters tobe noted on the same recording and a harmonigram. to be thus obtained. Likewise, a single power supply and buffer battery may be used for the entire system.

What I claim is:

1. In a device for indicating the advance and position of coal cutters and like stoping machines having a hauling chain, said device comprising a winch mechanically interconnected with said chain and mounted on a rotating shaft, a selective generator of electrical pulses disposed underground on said stopping machine, pulse conveying means, a selective pulse recorder and a rotary recorder both disposed at the surface, said rotary recorder rotating at a uniform speed about an axis and having a stylus displaced parallel to said axis by means of an endless screw which is step-by-step driven in opposite directions through the selective pulse recorder by addition and subtraction pulses, said selective pulse recorder being electrically connected by said pulse conveying means to said selective generator of electrical pulses, the improvement wherein said selective generator of electrical pulses comprises first generating means for generating first periodic rectangular pulses and second generating means for generating second periodic rectangular pulses having the same period and same length as the first periodic rectangular pulses, said rotating shaft being provided with control means for controlling successively said first generating means and said second generating means when the rotating shaft is rotated clockwise, whereby said first periodic rectangular pulses are phase advancing in relation to said second periodic rectangular pulses, and vice versa when the rotating shaft is rotating counter-clockwise, whereby said first periodic rectangular pulses are phase lagging, said selective pulse recorder comprising a recording unit and transit detection means for delivering said addition pulses when said first periodic rectangular pulses are phase advancing, and said subtraction pulses when said first periodic rectangular pulses are phase lagging, said transit detection means being connected to said pulse conveying means and said recording unit being connected to said transit means and to said rotary recorder.

2. A device according to claim 1, wherein said control means is a movable device comprising a plate mounted on said rotating shaft and a set of cams protruding on said plate, said first and second generating means being a pair of contact elements each generating a pulse when said cams travel therepast.

3. A device according to claim 1, wherein said control means is a static device comprising two photoelectric celltype detectors.

4. A device according to claim 1, wherein said transit detection means comprises first, second and third input combinative circuits receiving logic informations respectively of the simultaneous absence of first and second periodic rectangular pulses, of the existence of first periodic rectangular pulses and absence of second periodic rectangular pulses, and of the absence of first periodic rectangular pulses and existence of second periodic rectangular pulses, inputs of said input combinative circuits being connected to a transducer connected to said pulse conveying means, a first output combinative circuit for delivering said addition pulses, which circuit is connected to said recording unit, a first storage for storing the initial appearance of the simultaneous absence of a first periodic rectangular pulse and existence of a second periodic rec tangular ,pulse,

7 a second storage for storing the initial appearance of the simultaneous existence of a first periodic rectangular pulse and absence of a second periodic rectangular pulse, a sequence storage for storing the sequence of said initial appearances, a functional time-delaying operator for zeroing said storages upon the appearance of the simultaneous absence of first and second periodic rectangular pulses and a first intermediate combinative circuit, the output of the first input combinative circuit being connected to inputs of said time-delaying operator and first output combinative circuit, the output of said time-delaying operator being connected to the inputs of f the three said storages, the output of said second input combinative circuit being connected to the inputs of said second and sequence storages, the output of said third input cornbinative circuit being connected to the inputs of said first intermediate co-mbinative circuit and sequence storage, the output of said first intermediate cornbinative 'circuit being connected to the input of said first storage,

the outputs of said first and sequence storages being connected to the input of said first output combinative circuit and the output of said second storage being connected to the input of said first intermediate combinative circuit.

5. A device according to claim 4, wherein said transit detection means comprises a second output combinati-ve circuit for delivering said subtraction pulses, which circuit is connected to said recording unit and a second intermediate cornbinative circuit connected between said second input combinative circuit and said second storage, the output of said first storage being connected to the input of said second intermediate circuit, the outputs of said second storage, sequence storage and first input combinative circuit being connected to the input of said second output combinati-ve circuit.

6. A device according to claim 1, Wherein said selective pulse recorder comprises a potentiometer connected to said rotary recorder, means for supplying an adjustable voltage to said potentiometer, and a selsyn-type motor which is electrically connected to said transit detection means and which rotates through a given angle at each change of state of the input variables and which is operativcly connected to the shaft of said potentiometer.

. References Cited UNITED STATES PATENTS 6/ 1959 Cohen 346-35 346-33 2,889,189 3,220,011 11/1965 Fraisse

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