ROCK-SCALING DEVICE

Abstract: A rock-scaling device for use in mining operations in mine galleries or in tunnel construction operations. The device is adapted to be mounted on a crane structure. The device comprises an arm (18) consisting of an hydraulically operated piston-and-cylinder unit (21) wherein is rotationally mounted a tube (24). A rod (25) is axially displaceably but non-rotationally mounted in said tube (24). The rod (25) is actuated by the hydraulic piston-and-cylinder unit for reciprocating movements inwards and outwards. Turning movements of the tube is effected by a hydraulically operated rotary member (26) and tube movements thus also cause the rod (25) to turn. At the outer end of the rod is provided a chisel-shaped member (28). This member is intended to be inserted into cracks formed in the rock and to be turned. Upon turning movement of the chisel-shaped member the arm may pivot about a pin (17), since it is supported only by a spring (19). In this manner chisel-shaped member is eased into cracks, rendering the scaling operation efficient.

Description: Rock-Scaling Device BACKGROUND OF THE INVENTION The subject invention concerns a rock-scaling device for use particularly in mining operations. More precisely, the invention concerns a device which is adapted to be mounted on a crane structure which may be of a . type already known. In rock-blasting operations for ore mining, tunnel constructions or other purposes, cracks form in the rock, loosening boulders and stones therein, which makes the risk of slides and accidents »imminent. It is therefore necessary to break away and remove loose boulders and stones. Often, they are so loose that a msre touch is sufficient to cause them to fall. One method used to remove such boulders and stones is to use manual labour and long prying tools by means of which the boulders are hacked away. Obviously this method involves great risks to the workmen and this method is no longer allowed. ' Another method used for this purpose is scraping, that is, a crane-mounted bucket or similar tool provided with prongs is used to exert a scraping action on the ceiling and walls of the tunnel or mine gallery. However, this method is unsatisfactory, since many dangerously loose boulders or stones are not dislodged and the imminent risks of slides and accidents therefore remain. Still another prior-art rock-scaling method is to flush the walls and ceiling with high-pressure water jets. However, this method is disadvantageous since it wettens the walls, whereby distorting and deceptive water reflexes are created, which makes cracks difficult to discern. In addition, a foggy mist is generated in the gallery or tunnel, impairing visibility and delaying or obstructing further work. SUMMARY 0E THE INVENTION The subject invention provides a device by means of which rock scaling may be performed easily, safely and thoroughly, making the mine gallery or tunnel safe for further mining operations. The device in accordance with the invention is designed to be fitted onto a crane structure which may be of any conventional type and on the outer end of which an arm is pivotally mounted. The invention is characterised in that the arm supports on its outer end a rotatably mounted chisel- -shaped member the movements of which are controllable, that the arm is resiliently suspended in its direction of pivotment, whereby it can effect pivotal movements upon application of a force on its outer end, and that the chisel-shaped member is mounted on a projecting part of the arm. The device in accordance with the invention provide a number of advantages. The scaling operation is per¬ formed ' by a machine operator who, while remaining inside the control cabin is yet able to superwise the work and ensure that it is satisfactorily performed. Accessability with the use of a device in accordance with, the invention is excellent. The device in accordance with the invention operates smoothly and is flexible enough to penetrate deep into cracks, fis¬ sures and the like formed in the rock as opposed to O FI prior-art devices which only scrape and attack the surface layer. BRIEF DESCRIPTION OP THE DRAWINGS The invention will be described in closer detail in the following with reference to the accompanying drawings, wherein Fig. 1 is a lateral view of a device in accor¬ dance with the invention, mounted on a conventional crane structure, this drawing figure showing the de- vice while engaged in a rock-scaling operation, Fig. 2 illustrates on an enlarged scale a longi¬ tudinal sectional view through the device in accor¬ dance with the invention, Fig. 3 is a view from above of the apparatus in accordance with the invention, this drawing figure also indicating the operational range of the device, and Fig. 4 illustrates on a still larger scale a brake mechanism fitted to the device in accordance with the invention to restrain the pivotal movements in the horizontal plane. DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT The device in accordance with the invention, gene¬ rally indicated by numeral 1 , is mounted on a convention- al crane structure 2. The crane structure 2 consists of a truck 3 on which is pivotally mounted a first crane arm 4. At the upper crane arm end is also pivotally mounted a second crane arm 5. The two crane arms 4, 5 are operated by two hydraulic piston-and-cylinder units 6 and 7. The first crane arm 4 is preferably mounted on a rotary plate 8. At the upper end of crane arm 5 is mounted a holder 9 v/hich may be actuated by a hydraulically operated piston-and-cylinder unit 10. Two stay arms 11, 12 are provided to effect adequate movements of the holder 9- The holder 9 may be raised and iwered and also pivoted in the vertical plane. On the holder 9 is mounted a hydraulically operated rotary means 13 incorporating a shaft 14 (see Fig. 2). By controlling the-hydraulic pressure to the rotary hydraulic means the shaft 14 ' is turned to¬ gether with a plate 15 fitted thereon. The latter sup¬ ports two legs 16. Between the legs projects a pivot in 17 on which is pivotally mounted an arm 18 so as to be able to move in a vertical plane. A leaf-type of spring 19 which preferably comprises two sections and is secured both to the legs 16 and to a bracket 20 on the arm 18, prevents pivotal movement downwards of the arm 18. The arm 18 consists of a hydraulic piston-and-cy¬ linder unit 21 , formed by a cylinder 22 and a piston part or extension 23 mounted for movement inside the cylinder, A tube 24 is provided inside the cylinder. A rod 25 is displaceably mounted inside the ' tube, said rod having a non-round cross-sectional shspe over at least a part of its length. At least a part of the tube 24 has a matching interior cross-sectional shape, preferably a hexagonal or similar shape. This configuration may be obtained by welding a suitably shaped piece onto the upper part of the tube. In this manner, the rod 25 may perform axial reciprocating movements inside the tube but is prevented from turning relative thereto. A slit is formed in the extension 23 to allow movement of the extension relative to the bracket 20. The tube 24 is mounted in a second hydraulically operated rotary means 26. The hydraulic piston-and-cy¬ linder unit 21 , on the other hand, is rigidly secured to a plate 27 which is non-rotationally mounted. By means of the hydraulically operated rotary means 26 the tube therefore may be turned relative to the hydraulic piston-and-cylinder unit. At the outer end of the rod 25 is secured a chisel-shaped member 28. Alternatively, the outer end of the rod may be given this shape by forging its tip into the shape of a chisel. The rod is 'rotationally mounted on the extension 23 with the aid of a bearing 29, whereby the rod (and consequently the chisel-shaped member 28) take part in the outwards and inwards move¬ ments of the extension. Turning movement of the tube 24 results in turning movement also of the rod 25 and of the chisel-shaped member. Consequently, the latter may easily be actuated for movement in all directions from the operator's cabin of the truck 3. An indi¬ cator means 30 makes it easy for the machine operator to check visibly the position of the chisel-blade at any moment. As illustrated, the indicator means may be e.g. a cone-shaped member mounted on a rod. The characteristics of the leaf spring 19 are chos ¬ en to ensure that the arm 18 remains in the same angular position at all times. However, some pivotal movement of the arm in a vertical direction is possible when the arm is affected by an additional force to that of gravity in this direction. The plate 15 is equipped with a brake mechanism 31 (Fig. 4) . The latter consists of a brake shoe 32 on the plate 1 d ^ a braking means 33 which abuts against the shoe and is supported on a pin 34 on which is provided a stop shoulder 35- One end of a helical spring 36 abuts against the stop shoulder while the opposite spring end abuts against a stop shoulder 37 provided on a pin 39 the position of which may be set by a nut 38. By screwing the nut 38 in either direction the O PI pressure exerted by the braking means 33 on the brake shoe may be varied. The braking force thus can be controlled but could never reach an effect such as would prevent rotation of the plate 1 by means of the hydraulically operated rotary means 13. As illustrated in Fig. 3 the arm 18 may have a comparatively large operational range. This range may extend over considerably more than half a circle. " Fig. 3 also shows a protective hood 40 mounted over the joint between the arm 18 and the plate 15. A vibrator 41 is arranged at the mounting point of the chisel-shaped member 28 to the rod 25. The vibrator aids in loosening pieces of rock ~ by imparting vibration to the chisel-shaped member, which vibration may be ef ected also during the rotation of the chisel- -shaped member. The device functions in the following manner. A machine operator operates the device from inside the cabin of the truck 3. From the truck cabin, the operator is able to see the locations and nature of cracks in the rock. The indicator means 30 gives information on the position of the chisel blade. The operator inserts the chisel blade inside a crack while at the same tifπe turning the blade somewhat. The blade will penetrate deeply into the crack, because the pivotable mounting of the arm 18 and the construction and manner of attach¬ ment of the leaf spring 19 allow the arm to pivot some¬ what while the chisel-shaped member 28 is being inserted. In this manner,' the apparatus will automatically penetrate deeply into cracks, resulting in optimum rock- -scaling effects as regards thoroughness and efficiency. The mine gallery or tunnel, when scaled in this way, will offer maximum security during the continued working operations. The boulders or stones are then broken OMPI loose by turning the chisel blade and the vibrator may be used for this purpose to improve the loosening effect. To improve the efficiency of the device it is preferably fitted with an ultrasonic prober. The ultrasonic prober is preferably arranged so that readings and control thereof may be made from the. driver's cabin whereas the prober itself may be mounted close to the forward extremity of the arm 18. The provision of a prober of this kind makes it possible for the operator to discover cracks in the rock which the naked eye is not capable of discerning. In this manner the scaling operation may be performed more thoroughly than has hitherto been possible while at the same time all risks are eliminated that undis¬ covered stones, boulders or compacted stone dust remain after the scaling operation, endangering safety. The technique of ultrasonics is well known within the tech¬ nique of non-destructive testing of e.g. welded joints, for which reason the ultrasonic prober need not be described herein in any detail. The embodiment as described above and illustrated in the drawings is but an example and a variety of modifications are possible within the scope of the appended claims. The spring 19, illustrated as a two-part leaf spring, could be made of other kinds of spring dements. Alternatively, the spring may be dispensed with. Instead the aim 18 is allowed to extend beyond the pivot pin 17 and a balancing load is applied on the aim extension in such a manner and with the weight of the balancing load being chosen to ensure that the weight of the arm is balanced. The device may likewise be mounted on a crane specially designed for the purpose. Another preferred embodiment of the spring holding the arm 18 in position consists of two helical springs the winding turns of which extend in opposite directions, This spring is mounted at the pivot pin 17. Each spring is formed with two tangential arms one of which is secured to the arm 18 and the other one to the plate 15.

Claims: What I claim is:- 1. A rock-scaling device for use in rock and mineral mining and intended to ba mounted on a crane structure which may ba of any conventional typa and u/hich supports a pivotally mounted arm a ' t its outer and, c h a r a c t e r i s e d i n t h a t at its outer and said arm supports a rotatably mounted chisal-shapβd member tha movements of which are controllable, that said arm is rasiliantly suspended in its direction of pivot ant, tuharaby when a force is appliad at the outer arm end, the arm is able to perform pivotal movements, and that tha chisel-shapad member is mounted on a section of the arm that may be extended αutu/ards. 2. A rock-scaling davica as claimed in claim 1 , c h a r a c t e r i s e d i n t h a t the arm is a arranged on a plate which is rotatably mounted on the outer and of tha crane structure so as to render tha arm pivotablθ in a horizontal plane, and that the outer end αf tha crana structure may ba raised and lαiuarad and is so arranged that tha arm is allou/ad to pivot in a vertical plane ωith the aid of the crane structure. 3. A rock-scaling device as claimed in claim 1 or 2, c h a r a c t e r i s e d b y a rod ωhich is attached to the chisal-shapad member and arranged for sliding movements in a rαtationally mounted tube. 4. A rock-scaling device as claimed in any one of the preceding claims, c h a r a c t e r i s e d i n t h a t tha arm is pivotally mounted in a vertical plaπa on a pair of lags provided on said plata, the arm pivot point on said lags being positioned on tha line o . extension of the tube, and that tha arm is held in an angular position relative to the plate with the aid of at least one spring the resilience characteristics of which are chosen to ensure that- upon scaling oparations with tha aid of the chisal- -shapad member the arm automatically adjusts itself and assumes an adequate oparativa position. 5. A rock-scaling device as claimed in any ona of the preceding claims, c h a r a c t e r i s e d i n h a t said spring is a leaf spring which may be formed in two. piacas and which is attached to the legs and to a bracket provided an tha arm, said bracket arranged in a slit formed in the extension section of tha arm. 6. A rock-scaling device as claimed in any one of the preceding claims, c h a r a c t e r i s e d i π ' t h a t at least a part of the rod has a non- -round configuration and that this non-round part extends through a portion of the tube having a matching inner configuration. 7. A rock-scaling device in any one of the preceding claims, c h a r a c t e r i s e d i n t h a t a brake mechanism is provided on the outer end of the crana structure, this brake-mechanism being arranged to counteract rotational movements of the plate, that is, pivotal movements in tha horizontal plane of the arm, and in that the brake-mechanism consists αf a brake shoe formed on the lower face of the plate and of a spring-loaded pin, the latter being pressed against the brake shoe by an adjustable spring. OMPI y 8. A rock-scaling device as claimed in any oπa of the preceding claims, c h a r a c t e r i s e d i n t h a on the part of the tube that is opposite to tha lags is fixedly mounted a tube portion having a hexagonal configuration, and. that the rod that is attached to tha chisel-shaped member has, a matching inner hexagonal configuration. 9. A rock-scaling device as claimed in any one of the preceding claims, c h a r a c t e r i s e d i n 10 h a t the tuba is mounted on a first hydraulically operated rotary member arranged adjacent the legs and in that the plate is arranged on a shaft, which shaft is rαtationally mounted on a second hydraulically operated rotary member. 15 10. A rock-scaling device as claimed in any one of tha precading claims, c h a r a c t e r i s e d b y an indicator means arranged in such a manner on the chisel-shaped member that the machine operator is able to discern the rotational position of tha chisel-member 20 blade from his normal control position, and by a vibrator which is so arranged adjacent the chisal-shaped amber that it may cause the chisel-shaped member to vibrate, and by an ultrasonic prober arranged to be used to examine the rock. 25

Inventors: FORSBERG AXEL MARTIN
Applicants: FORSBERG AXEL MARTIN
Application year: 1982
Main classification: E21C37
IPC codes: E02F3, E21C37, E21D9