US 3192704 A
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Description (OCR text may contain errors)
July 1955 R. L. J. MACRAE 3,192,704
MEANS FOR PROTECTING THE SUPPLY CABLES OF MINING MACHINES 4 Sheets-Sheet 1 Filed March 1, 1962 FIG.3
y 6, 1.965 R. 1.. J. MACRAE 3,192,704
MEANS FOR PRQTECTING THE SUPPLY CABLES OF MINING MACHINES Filed March 1, 1962 4 Sheets-Sheet 2 y 6, 1955 R. J. MACRAE 3,192,704
MEANS FOR PROTECTING THE- SUPPLY CABLES OF MINING MACHINES Filed March 1, 1962 4 Sheets-Sheet a FIG. 5.
y 1955 R. L. J. MACRAE 3,192,704
MEANS FOR PROTECTING THE SUPPLY CABLES OF MINING MACHINES I 7 Filed March 1, 1962 v v 4 Sheets-Shet 4 farm/45AM M w/P 4M fi'wlw 72% Amway:
United States Patent C) 3,192,794 MEANS FUR PRGTECTTNG THE SUFPLY CABLES 0F MENHQG MACES Ronald L. 3. h iacrae, Ashhy-de-la-Zoueh, England, assignor to Coal Industry (Patents) Limited, London, England Filed Mar. 1, N62, er. No. 176,693 4 Claims. ill. 59-78.!)
This invention relates to means for protecting a flexible cable leading to a machine of the type which in operation travels to and fro over a defined path and is supplied with power (hydraulic, pneumatic or electric) through flexible trailing cables connected at one end to the machme and at the other end' to a power supply. Such machines will hereinafter be referred to as of the type described. One example of sucha machine is a mining machine arranged to traverse the face of a coal seam and in that case the cable may be a supply cable. It will be understood that the word cable includes hose.
It is a present practice where such mining machines are in use, to lead the trailing cable to the mid point of the face, and to anchor it at that point. From there, a length of cable equal to half the travel of the mining machine, is led to the said machine. As the mining travels from one end of the face to the other, the flexible cable which, when the machine is at one end of its travel, is fully ex tended, is turned back on itself to form a loop which is dragged along by the mining machine until the machine reaches the other end of the face when the cable is once again fully extended. As the said machine moves in the opposite direction, a reverse loop is formed, and this is, in turn, dragged down the face. This system has the following disadvantages.
(i) The cable is under tension, due to the friction of its own weight, and is thus liable to suffer damage.
(ii) The cable is free to rub on itself and other surfaces,
and the outer cover can be severely abraded.
(iii) Unless an operator supervises the trailing loop, the latter is liable to be fouled and fractured by projections found on a mineral face.
An object of the present invention is to provide means for protecting a flexible cable of a machine of the type described, and, in accordance with the present invention, this object is achieved by providing a chain for carrying the flexible cable, the chain being so constructed that the flexible cable whilst being free to form a natural loop within its length to follow movement of the machine, is not subjected to dragging tension, does not rub on itself or the floor, and is protected against damage arising through fouling of the loop. The chain links are constructed and spaced in such a manner that when the chain is folded back on itself to accommodate looping of the carried cable, the upper length of chain can slide freely on the lower length.
A trough may be provided, adapted to accommodate the chain in its folded condition and arranged to extend over the full distance of travel of the machine; where the machine is a mining machine, the trough is conveniently provided on a face conveyer with which the mining machine in operation co-operates.
The chain may be connected to the machine by a first swivel attachment adapted to permit the portion'of chain adjacent the machine to move from a position in which it extends in one direction relative to the machine to a position in which it extends in the opposite direction. The chain may be connected towards one end of a second similar'swivel attachment at a location intermediate the ends of the path of the machine; the said second swivel attachment may be arranged for limited translational movement in' a direction parallel to the path of the machine and may be adapted to perform said translational movement when ice the machine approaches one end of the said path, whereby the power supply to the machine is cut oil".
Two embodiments of the present invention will now be described in greater detail, by way of example only, with reference to the accompanying drawings of which FIGURE 1 shows a plan View, partly in'section, of one form of chain,
FIGURE 2 shows a view of'one of the channel-shapedlinks in'the direction of arrow A in FIGURE 1,
FIGURE 3 is a cross-sectional view along line 33 o'f FIGURE 1, with an electric cable and a water hose in position in the chain, 7
FIGURE 4 shows a vertical transverse section through a trough mounted on theside of an armoured'fiexibleconveyor (part only of which is shown), the'trough accommodating two lengths of the chain shown in FIGURES 1-3, on'e'length of chain resting on the other,
FIGURE 5 shows schematically and in plan view a general arrangement of a mining machine mounted for move ment along an armoured flexible conveyor and having a flexible trailing cable protected by the means of the present invention,
FIGURES 6, 7 and 8' show schematically and in side views various positions of the arrangement of FIGURE 5, parts only'of the arrangement being shown,
FIGURE 9 shows a plan view of a second form of nected together alternately with links 3 each constituted by a pair of parallel plates secured'to links 2 by riviets 4. The link 2 are channel-shaped in the direction of the length of the chain 1 so that, as can be seen in FIGURE 3, the electric supply cable 5 and, as shown, the water hose 6 'of the'rnining machine to which the chain 1 is to be attached, can be fully inserted into the-longitudinal opening defined by the series of links 2. The cable 5 (and the water hose 6) is retained in the links 2 by the provision in eachlink 20f a removable pin 7 which extendsacross the otherwise openside S of the link 2 opposite to the base 9to which the" adjacent links 3 are connected. It will be seen that each link 2 comprises upper and lower vertically-spaced horizontal limbs 10 interconnected by an upstanding pom tion' 9 to form a generally U-sectioned link. As can be further seen from the drawing, portions 9 on adjacent? links are pivotally connected together for relative movement about parallel and horizontal axes disposed trans verse" to the length of the chain; The limbs 10 are dis- Y posed all in the same direction to define the longitudinal opening for the cable; The limbs 10 of each linkare each strengthened by an" integral longitudinal rib 11, whilst the upstanding portion 9 is similarly strengthened by an integral transverse rib 1 3which constitutes a continuation of the ribs 11. To permit sliding of the chain on itself in a manner to be described below, it will beseen that each limb ltl of each'link 2 has a-length in the direction of the chain, greater than the distance separatingadjacent limbs it) on immediately adjacent links, and has opposed lateral V edge portions lZ'inwardly turned towards the central axis of the chain.
The use of the above described chain will now be de'- scribed with reference to FIGURES 4-8.-
Fr-om FIGURE 5 will be seen the general arrangement of'a mining machine'Zll (of which one end only is shown) which traverses the coal face (not indicated); on the armoured conveyor 21. The conveyor 21 (see FIGURES 4 and'S) differs from the well-known armoured conveyors only in that there is attached to the goat side of the conveyor and extending along its length a fabricated trough 22 (FIGURE 4) of such internal dimensions as to receive both lengths 23 and 24 of the chain 1 when it is folded upon itself. The mining machine 2% is supplied with power through a flexible cable 5 having a first portion 5a leading from a source of supply (not shown) to a swivel (see below) located at the mid-point of the conveyor 21 i.e. the mid-point of travel of the machine 2-3, and a second portion 5b extending between the swivel 25 and the machine 20, the latter portion 5!; having a length equal to half the travel of the machine 2%. The cable portion 512 is inserted into the chain so as to be effectively enclosed thereby on all sides except in the vicinity of the longitudinal opening in the chain, where pins 7 are inserted at spaced intervals to prevent movement of the cables laterally out of the chain.
In FIGURES 5-8, for the sake of clarity, only a part of cable portion 5b is shown as being enclosed in the links 23 of chain 1 but it will be understood that the whole length of cable portion 51) between the machine 28 and a swivel 25 is so enclosed. Similarly, in FIGURES 58 the water hose 6 has also been omitted.
The chain 1 is connected at one end to the machine 29 by means of a swivel attachment 26 comprising a tubular elbow 27 to which the last link 3 of the chain I is directly connected at 28, which is rotatably mounted in a bearing block 29 secured on the machine 29.
The swivel 25 is similar to swivel attachment 26 and is mounted at the mid-point of the traverse of the machine for limited sliding movement in a frame 3 The, mouth 32 of the tubular elbow 31 of swivel 25, through which the cable 5 projects is arranged in line with the trough 22 and the outer side wall of the trough 22 is cut-away at this point to permit the elbow 31 to be pivoted into the oppositely facing position (see FIGURES 7 and 8).
Mounted in the frame such as to project in the path of the swivel bearing block 33 is an electrical switch plunger 34 which operates to cut-off the supply of power to the haulage motor of the machine 2%,
The operation of the above described arrangement is as follows:
Assuming the machine is in the position shown in FIG- URE 5 and is traversing in the direction of arrow A, the chain 1 will be folded upon itself and the upper length 23 will slide over the lower length 24. It is to be noted at this stage, that the spacing and construction of the links 2 (FIGURE 1) is such that the links 2 of the upper length 2 3 will slide freely on the links 2 of the lower length. Thus, the upper length 23 of chain 1 can slide on the lower length 23 without engaging or damaging the portion of the cable 5 in the lower length 2 The upper length 23 continues to slide over the lower length 24 as the machine 28' traverses the face through the position of FIGURE 6 (in which a part of the upper length 23 is still moving over the lower length 24 and a part of the upper length 23 is clear of the lower length 24 and engages directly in the trough 22 not shown in FIGURE 6) to the position in FIGURE 7 in which the machine 20 is approaching the right-hand end of its traverse. In the position of FIGURE 7, the whole length of the chain It now directly engages within the trough 22 and, after the elbow 31 of swivel 25 has pivoted from a position in which it faces to the left (see FIGURE 6) to a position in which it faces to the right (see FIGURE 7), the chain 1 lies in a straight line in the trough 22. It will be noticed also that the bearing block 33 has been moved a short distance to the right from the position shown in FIGURE 6 by the machine 26 towing the chain 1, and that the upper surface of block 33 is about to engage (and thus depress) the switch plunger 34. Continued movement of the machine 20 in the direction of arrow A (FIGURE 5) causes the plunger 34 to be depressed by the block 33 thus operating its switch such as to stop the machine 20.
Even after the switch is operated by plunger 34, the machine 20 will continue for a short distance due to its inertia and delay in arresting the machine, so that by the time the machine 2%} actually stops, the block 33 will have been drawn clear of the plunger 34 as shown in FIG- URE 8.
The installation is now ready for traverse of the machine 29 across the face in a direction opposite to that shown by arrow A in FIGURE S. Traverse of the machine Zil in this direction causes the above described events to occur but all in the opposite sense.
In FIGURES 9 and 10, and 11, of the accompanying drawings is shown a second form of chain which can also be used in the manner described above. The chain shown in FIGURES 9 and 10 comprises channel-shaped links 42 each provided at one end with an apertured lug 43 and at the opposite end an apertured fork 44, the links 42 being pivotally connected together by rivets 48 each of which passes through the apertured lug 43 of one link 42 and the apertured fork 44 of the adjacent link 42. It is seen in FIGURE 10 that the strengthening integral rib 56 in this case presents an arcuate surface to the cable 45. The cable &5 (and water hose 46) is retained in the links 42 by the provision in every fifth link of a spring dowel pin 47. Further strengthening of each link 42 is provided by the inturned portions 52 which also serve to ensure that when the chain is folded on itself one length can slide freely on the other length.
1. Means for protecting a flexible supply cable arranged to connect a source of supply to a unit movable relative to said source of supply, comprising a chain adapted to receive and carry said flexible supply cable, said chain comprising a plurality of links each having a lower horizontal limb, an upper horizontal limb spaced above said lower horizontal limb and an upstanding portion interconnecting upper and lower limbs to form a generally U-sectioned link. said links being arranged with their limbs direction all in the same direction towards one side of the chain to define an opening longitudinally of the chain, into which opening said flexible supply cable can be frilly inserted, and means pivotally connecting adjacent links to each other for relative movement about parallel and horizontal axes disposed transverse to the length of the chain, each horizontal limb of a link having a length in the direction of the chain, greater than the distance separating immediately adjacent limbs on adjacent links and further having opposed lateral edge portions disposed transverse to the length of the chain, which edge portions are inwardly turned towards the central aXis of the chain whereby when the chain is folded back on itself, an upper length of the said chain can slide freely on a lower length of the said chain.
2, Means for protecting a flexible supply cable arranged to interconnect a source of supply and a mining machine mounted for travel along an armoured face conveyor, said source of supply being disposed intermediate the ends of the conveyor, comprising a chain adapted to receive and carry said flexible supply cable and having one end attached to a location immediately adjacent said source of supply and the opposite end attached to the mining machine, and a trough mounted on one side of said conveyor and adapted to support said chain, the latter comprising a plurality of links each having a lower horizontal limb, an upper horizontal limb spaced above said lower horizontal limb and an upstanding portion mterconnecting said upper and lower limbs to form a generally U-sectioned link, said links being arranged with their horizontal limbs directed all in the same direction towards one side of the chain to define an opening extending longitudinally of the chain, into which opening the said flexible supply cable can be fully inserted, and means pivotally connecting adjacent links to each other for relative movement about parallel and horizontal axes disposed to the length of the chain, each horizontal limb of a link having a length in the direction of the chain,
- greater than the distance separating immediately adjacent limbs on adjacent links and further having opposed lateral edge portions disposed transverse to the length of the chain, which edge portions are inwardly turned towards the central axis of the chain whereby when the chain is folded back on itself, an upper length of the said chain can slide freely on a lower length of the said chain.
3. Means as claimed in claim 2, wherein the said end of the chain attached to a location immediately adjacent said source of supply, is connected to a swivel attachment adapted to permit a portion of the chain adjacent the said location to move from a position in which said portion extends in one direction relative to said location to a position in which said portion extends in the opposite direction.
4. Means as claimed in claim 3, wherein said swivel 1 attachment is aranged for limited translational movement in a direction parallel to the path of movement of 5 translational movement to co-operate with switch means operative to stop further movement of the machine.
References Cited by the Examiner UNITED STATES PATENTS 10 2,864,907 12/58 Waninger.
3,020,362 2/62 Waninger 59-78 FOREIGN PATENTS 14,773 6/ l 1 Denmark.
CHARLES W. LANHAM, Primary Examiner.