US2704654A - Rock drilling device - Google Patents

Description

March 22, 1955 w. BANCK EI'AL 2,704,654

ROCK DRILLING DEVICE Filed March 11, 1952 :s Sheets-Sheet 1 INVf/Vfdkd UM M W I QM W mwz.

March 22, 1955 W. BANCK ETAL ROCK DRILLING DEVICE 3 Sheets-Sheet 2 Filed March 11. 41952 March 22, 1955 w. BANCK ETAL 2,704,654

ROCK DRILLING DEVICE Filed March 11, 1952 3 Sheets-Sheet 3 United States PatentO ROCK DRILLING DEVICE Werner Banck, Stuttgart, Ottmar Baur, Wendlingen, Karl Hiigele, Stuttgart-Wangen, and Wendel Rolli, Stuttgart- .Degerloch, Germany, assignors to Robert Bosch G. m.

b. H., Stuttgart, Germany Application March 11, 1952, Serial No. 275,962

Claims priority, application Germany March 24, 1951 3 Claims. (Cl. 25545) The invention concerns a rock drilling device having a drill which is displaceable, along a girder-like support through hydraulic pressure. Drilling devices are known in which a cylinder, extending in the direction of drilling, is located wholly or substantially wholly behind the drill and with its. hydraulically actuated piston leads the drill forwardly on a girder which is not directly connected with the cylinder and which consists of two sliding guides. This arrangement necessitates a construction of considerable overall length and weight, since the girder and the means for advancing the drill must be secured separately and must be able to withstand various loads. In addition the drill advancing means of the known arrangement is largely exposed to the rock dust.

According to this invention, the girder-like support of the drill consists of a hollow body or tubular member which houses in its interior a piston and cylinder assembly adapted to be connected to the source of pressure and, by means of intermediate connecting means, to advance the drilling machine along the hollow support.

According to another aspect of this invention, a rock drilling device consists of a girder-like support in the form of a hollow body or tubular member, a drilling machine slidably mounted in the hollow body or tubular member, a .cylinder housed within the hollow body or tubular member for connection with a source of fluid pressure, a piston in the cylinder, and intermediate means connecting the piston and drilling machine and adapted to enable the piston to displace the drilling machine along the hollow body or tubular member for advancing the drilling machine when the fluid pressure is supplied to the cylinder.

This arrangement enables the drill advancing means to be largely protected from rock dust and other foreign matter, whilst ,the overall length of the drilling device can be made to conform approximately to that of the depth of the bore hole at least, but in any case is much shorter than that of the known type. In addition a rock drilling device according to this invention possesses sufiicient stability although being relatively light in weight.

The invention is further described with reference to the accompanying drawings in which illustrate two embodiments of the invention by way of examples only and in which:

Fig. 1 is a side elevation partly in section, and Fig. 2 a corresponding end view of the first embodiment,

Fig. 3 is a side elevation also partly in section of the second embodiment,

Fig. 4 is a diagrammatic view of the connections to the valve; and

Fig. 5 is a side elevational view partly in section of the pump, motor and governor which produces the pressure to advance the drilling machine. 1

Referring first to Figs. 1 and 2 of the drawings, a tubular support 1 has two slide guides 2 welded thereon which support and guide a slide 3 onwhich an electric drilling machine 4 is mounted. The latter firmly holds a rock drill 5.

. Disposed in the interior of the tubular support 1 is a cylinder 6, the base 7 of which is located at the forward end 8 of the tubular support 1 facing the bore hole. Displaceably disposed in the cylinder 6 is a piston 9 wherefrom extends a piston rod 10 which carries a reversing or return roller or pulley 11 at the end remote from piston 9. A second reversing or return roller or pulley 12is fitted at the forward end 8 of the tubular support 1. One end of a chain 13 is anchored at 14 in the interior of the tubular support 1. From the anchorage 14 the chain extends rearwardly, around the roller 11 and then forwardly along the lower part of the tubular support 1 to emerge from the end 8 thereof. The chain is then led around the roller 12 and extends rearwardly to the slide 3 and is secured thereto.

The cylinder 6 is approximately half the length of me tubular support 1. A hydraulic pump 16 is mounted at the rear end 15 of the tubular support 1. It is driven by an electric motor 17 which is also mounted on the tubular support 1. On each side of the electric motor 17 there is fitted a fluid tank or reservoir respectively designated 18 and 19. These reservoirs are interconnected by means of pipe lines which are shown in Figures 4 and 5. A pipe 20 (Fig. 2) leads from the reservoir 18 to the suction side of the pump 16. From the pressure side of the pump 16 a pipe 21 leads to the casing 22 of a rotary control valve which is actuated to change the direction of flow by means of a handle 23. From the valve casing 22 a pipe 24 leads to an intake port 24 in the right hand end of the cylinder 6. This pipe runs lengthwise in the interior of the tubular support 1. Additional pipes 25 and 26 lead from the valve casing 22 to the respective reservoirs 18 and 19. In the position shown on the drawings, the control valve is adapted to connect the pipes 21 and 24. When the valve is turned through an angle of the pipes 21 and 26 as well as the pipes 24 and 25 are connected to one another. The pump 16 contains a governor as will be described. The object of the governor is to maintain the pressure of the fluid supply at a certain value, which is adjusted by means of a control handle 27 in accordance with the character of stone or rock to be drilled.

It will be obvious that the distance through which the drilling machine 4 may be retracted along the hollow member 1 towards its rear end 15 will be determined by the effective length of the chain 13. Also, the drilling machine need not necessarily be secured to the end of the chain 13. It may take up a position somewhat forward of the end 15, when in its left end position, depending on the length of the drill 5 in use or whether the stroke of the drilling machine is required to be long or short. If the drilling machine is to be anchored to the chain 13 at a point spaced from its end, then the free or ineffective length of the chain may be rolled up and placed in the base of the drilling machine or in any other convenient position.

The hydraulic operation means and their connections are shown in the Figures 4 and 5. The motor 17 of any suitable and known type turns gears 36, 37 to drive shaft 38 of the pump 16. This pump may be constructed in any known manner; by way of example a type similar to usual fuel injection pumps is shown. A cam 39 fixed to the shaft 38 engages the lower end of a piston 40, which is forced against the cam by a spring 41. The upper end of this piston is provided with an oblique control edge 42; which is controlled by a governor described by way of example in the following.

The piston 40 is guided in the housing 43 of the pump and the cylinder 44. A channel 45 connects this cylinder with the suction pipe 20. The port of this channel leading into the cylinder lies within the range of stroke of the control edge. Another channel 46 leads from the top of cylinder 44 to a check valve 47 and the delivery pipe 21.

The piston 40 is provided with a pinion 48, which meshes with a rack 49 guided horizontally in the housing 43. At the left end of this rack a piston 50 is slidably arranged in a cylinder 51. The space of this cylinder on the right side of the piston 50 is separated from the outside and connected to channel 46 by a passage 52. Against the left side of the piston 50 presses a spring 53, seated against a plate 54. This plate is fixed to a lever 55, which lever is pivoted at 56 in the housing 43. The control handle 27 is the head of a screw 57 the tip of which is in contact with the lever 55.

When driven by the motor 17, the piston 40 reciprocates and delivers fluid through the check valve 47 into the pipe 21. The amount of delivered fluid depends upon the position of the control edge 42 with respect to the port of the channel 45, an effect known in fuel-injection pumps. By turning the piston the position of the control edge is altered and the amount of delivered fluid is varied.

The pressure of the spring 54 acts on the left side of the piston 50, and the delivery pressure acts on its right side. Equilibrium is reached when both forces are equal. An increase of the delivery pressure moves the piston 50 with the rack 49 towards the left, changes the position of the control edge 42 of piston 40, the port of channel 45 is opened for a longer interval until the equilibrium of piston 50 is restored and at a predetermined head of pressure no fluid is pumped. The head of pressure is determined with the aid of handle 27 turning the screw 57, which screw moves the lever 55. The movement of this lever changes the initial pressure of the plate 54 against the spring 53.

The pipe connections to the valve 22 according to Fig. l are diagrammatically shown in Fig. 4. The pipe 21 and pipe 24 are at a right angle with each other and are connected with valve 22. The pipes 25 and 26 are connected with the valve at points opposite of them. The valve member 57 has two channels 58 and 59, connecting in the shown position the pipe 21 with pipe 24 and pipe 25 with pipe 26. After turning the member by 90, the channels connect pipe 21 with pipe 26 and pipe 24 with pipe 25.

The pipe connections according to Fig. 3 are shown in Fig. 5. Pipes 21 and 24 are arranged in the same way as above, opposed to pipes 25 and 31. Pipe 26 is branched of pipe 25. As the valve member being the same as in Fig. 4, it is apparent that in the shown position pipe 21 is connected to pipe 24 and the right end of the cylinder chamber 29, and pipe 31 coming from the left end of the chamber 30 is connected to pipe 25. When turning the valve member by 90, the connections are changed over.

The construction of the valve 22 is merely shown by way of example; it may be arranged, like the pump and the described governor, in any other known manner.

At the beginning of a drilling operation, the drilling machine 4 is disposed at its left final position near the rear end 15 (Fig. 1) of the tubular support 1. The piston 9 is initially situated near the cylinder base 7 and the piston rod 10 is drawn into the cylinder 6 so that the roller 11 is moved to its right hand end position adjacent to the open end of the cylinder 6. When the drilling machine 4 is switched on the drill rotates. When the electric motor 17 has been switched on, the pump 16 discharges fluid into the pipe 21. From this pipe the fluid flows, with the valve 22 in the position illustrated, via the pipe 24 into the cylinder 6 to the right hand side of the piston 9. Pressure fluid entering cylinder 6, forces the piston 9, together with the piston rod and the roller 11, to the left, thus drawing the right hand portion of the chain 13 into the tubular support 1. Consequently, the part of the chain lying above the tubular support 1 travels around the roller 12 to advance the drilling machine 4 with drill 5 towards the bore hole at a pressure dependent upon the pressure adjusted at the pump and the effective surface area of the piston. In the arrangement illustrated, the path travelled by the drilling machine 4 is twice as long as the stroke of the piston 9.

If the drilling machine 4 is to be retracted again, or if the forward motion is to be interrupted, the handle 23 of valve 22 is turned through 90. Nevertheless, the pump 16 can still continue to operate since in this case it discharges to the reservoirs 18 and 19 via the pipes 21 and 26. If the drilling machine is moved backwards, then the chain 13 is drawn out of the tubular support 1. Through this action, the roller 11, piston rod 10 and piston 9 are pushed forwardly into the cylinder 6 and the liquid contained therein is forced back to the valve casing 22 through the pipe 24. From the latter it flows back via the valve bores through the pipe 25 to the reservoirs l8 and 19 which, as previously mentioned, are interconnected.

In the embodiment illustrated in Fig. 3, the previously described arrangement has been extended so that the drilling machine 4 can be retracted as well as advanced by hydraulic pressure in the following manner. A doubleacting piston 28 is inserted in the cylinder 6, the piston rod 10 of which is sealed at the open end of the cylinder 6 so as to form two working chambers 29 and 30. The chamber 29 is connected with the valve casing 22 by means of the pipe 24 as in the previous example, and the chamber 30 by means of a pipe 31 which extends from near the rear end of the cylinder into the chamber 30.

In this example, the valve casing 22 and its valve are constructed so that, in the position illustrated, the pipes 21 and 24 as well as the pipes 31 and 25 are connected together and after turning the valve through 90 the pipes 21 and 31 and the pipes 24 and 25 are connected together. Apart from the reversing roller or pulley 11, a further reversing roller or pulley 32 is secured to the piston rod 10 alongside the pulley 11. One end of a second chain 33 is anchored to a bracket 34 secured to the inside of support 1 and passes around the roller 32 and over a further reversing roller 35 out of the tubular support 1 to be secured at its other end to the slide 3. The remaining parts of the device correspond to those of Fig. 1.

During the forward feed motion of the drilling machine 4, the pressure fluid flows through the pipe 24 into the chamber 29. The piston 28 is thus retracted to the left and with it the piston rod 10; the latter advances the slide 3 by means of the roller 11 and the chain 13, as previously described in connection with Fig. 1. At the same time the chain 33 is pulled out of the tubular sup.- port 1 by the slide 3 in accordance with its forward feed motion; thus, the chain 33 traverses the rollers 35 and 32, whereby the latter roller moves with the piston rod 10 in such a manner that the required length of the chain is released. The fluid contained in the chamber 30 flows during this operation through the pipes 31 and 25 into the reservoirs 18 and 19.

If the drilling machine 4 is to be retracted, the handle 23 of valve 22 is turned through a further right angle so that the pressure fluid now flows through the pipes 21 and 31 into the chamber 30 and forces the piston 28 into the cylinder 6. Although the effective surface area of the piston 28 is smaller on this side than on the other side owing to the presence of the piston rod, the return motion proceeds at a speed greater than the forward motion. The roller 32 when moving in the drilling direction, with the piston 28 and the piston rod 10, consequently draws the chain 33 into the support 1 via the roller 35; the chain 33 thus moves the slide 3 together with the drilling machine 4 towards the rear of the support. The slide 3 in turn draws the chain 13 out of the support 1 via the roller 12. This is rendered possible by the fact that the roller 11 moves to a corresponding extent in the drilling direction.

To obtain a symmetrical construction of the device, one of the chains 13 or 33 may be duplicated, one of these chains lying on each side of the central plane and symmetrical therewith. The device may be further supplemented by means of known supporting and guide members for the chains, piston rod and drill. In both constructions the hydraulic pump 16 together with the driving motor 17 and if necessary with the tanks or reservoirs 18 and 19 may be united to form one complete unit which is secured on the support 1.

We claim:

1. A rock drilling machine comprising an elongated tubular body member having inner and outer closed ends, a cylinder positioned axially in the body member and having an outer closed end disposed adjacent the outer end of the body member and having an inner end spaced from the inner end of the body member, a piston working in said cylinder, a piston rod carried by the piston and slidably and sealingly extending through the inner end of the cylinder, a pulley rotatably mounted on the inner end of the piston rod and rotatable about an axis transverse to the piston rod, an elongated flexible connecting member having one end anchored inside the body member and entrained over said pulley, said outer end of the body member having an opening through which the flexible member is slidingly passed, a guide pulley carried by the body member and disposed forwardly of the outer end thereof and rotatable about a fixed axis transverse to the body member, said flexible member being entrained over said guide pulley, a drilling machine slidably mounted on the body member for guided movement axially thereof, means attaching the other end of the flexible member to the drilling machine and means carried by the body member adjacent its inner end for supplying operating fluid to the cylinder to act on the piston and piston rod to move the drilling machine outwardly on the body member.

2. A machine as claimed in claim 1, wherein said last means includes a hydraulic pump and motor mounted as a unit on the inner end of the body member and having fluid lines connecting with the cylinder and extending through the inner end and a hand control for said lines adjacent said end.

3. A machine as claimed in claim 2, wherein a second pulley is rotatably mounted on the inner end of the piston rod, a second elongated flexible member connected at one end to the drilling machine, a guide pulley rotatably mounted at the inner end of the body member and over which the second flexible member is entrained, means securing the other end of the flexible member inside the body member, said fluid lines being connected to the References Cited in the file of this patent UNITED STATES PATENTS 1,572,371 Smith Feb. 9, 1926 1,844,873 Smith, Sr. Feb. 9, 1932 2,075,706 Curtis Mar. 30, 1937

Images