AU688841B2

AU688841B2 - Feed-extension cylinder arrangement in a feed beam for a rock drill

Info

Publication number: AU688841B2
Application number: AU13877/95A
Authority: AU
Inventors: Leo Hakkinen; Heikki Jantunen
Original assignee: Tamrock Oy
Current assignee: Tamrock Oy
Priority date: 1994-01-05
Filing date: 1995-01-03
Publication date: 1998-03-19
Anticipated expiration: 2015-01-03
Also published as: WO1995018913A1; FI940042A; FI97252B; ZA9525B; AU1387795A; EP0738367A1; FI940042A0; CA2180536A1; FI97252C

Description

WO 95118913 PCT/F95/00002 1 Feed-extension cylinder arrangement in a feed beam for a rock drill The invention relates to a feed-extension cylinder arrangement in a feed beam for a rock drill, the feed beam comprising a lower beam and an upper beam, the lower beam having two vertical side portions and a transverse bottom between the side portions so that the side portions and the bottom define between them a chute-like space, upon the open side of which the upper beam is mounted longitudinally slideably with respect to the lower L and a feed-extension cylinder connected to act between the upper beam and the lower beam, the feed-extension cylinder being mounted in the chute-like space of the lower beam below the upper beam, and the cylinder pipe of the feedextension cylinder and its piston rod being connected to act between the upper beam and the lower beam so that when the feed-extension cylinder is extended, it displaces the upper beam towards the front end of the lower beam, and when the feed-extension cylinder is shortened, it displaces the upper beam towards the rear end of the lower beam.

Telescopic or extension feed beams comprise two superimposed beam portions, i.e. a lower beam and an upper beam slidable upon it. In the drilling process, longer holes are drilled at two stages, i.e. the drill moves along the upper beam by means of a feed device formed by a cylinder and a wire, while the upper beam is displaced upon the lower beam by means of a separate feed-extension cylinder in order that the entire feed length of the beam could be utilized. In prior art solutions, the cylinder displacing the upper beam has been realized by fixing one end of the cylinder pipe to the lower beam and the piston rod to the upper 2 beam so that it protrudes from the rear end of the lower beam when the upper beam has been displaced backwards. A disadvantage of this solution is that the piston rod is unprotected and subject to dirt and damage. This in turn increases the demand of maintenance and various maintenance costs.

The object of the present invention is to provide an arrangement that avoids or reduces the known disadvantages and provides a structure as simple and reliable as possible.

According to a broad aspect of the present invention there is provided a feed-extension cylinder arrangement in a feed 15 beam for a rock drill, the feed beam comprising a lower 'beam and an upper beam, the lower beam having two vertical

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side portions and a transverse bottom between the side portions so that the side portions and the bottom define between them a chute-like space, upon the open side of which the upper beam is mounted longitudinally slideably with respect to the lower beam; and a feed-extension cylinder connected to act between the upper beam and the lower beam, the feed-extension cylinder being mounted in the chute-like of the lower beam below the upper beam, and 25 the cylinder pipe of the feed-extension cylinder and its

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piston rod being connected to act between the upper beam and the lower beam so that when the feed-extension cylinder is extended, it displaces the upper beam towards the front end of the lower beam, and when the feed-extension cylinder is shortened, it displaces the upper beam towards the rear end of the lower beam, wherein the cylinder pipe of the feed-extension cylinder is fixed to the lower beam or to the upper beam immovably with respect to it, and the piston rod is correspondingly connected at its end to the front end of the upper beam or to the rear end of the lower beam so that it is able to move in the transverse direction of the upper beam or the lower beam, respectively, but i/ \\ELBOt\home$\Vtcky\Keep\speci\13877.95.doc IS/01/9B Ky

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3 substantially immovably in its longitudinal direction.

Preferably a feed cylinder for the rock drill and the feedextension cylinder are hydraulically interconnected so that the feed forces of the feed cylinder and the feed-extension cylinder are equal throughout the drilling process.

Preferably a first feed line for hydraulic fluid is connected to both the feed cylinder and the feed-extension cylinder to a cylinder space unoccupied by the piston rod, said first feed line is also connected through a shuttle valve to the cylinder space of the feed-extension cylinder on the side of the piston rod, a second feed line for pressure fluid is connected to the cylinder space of the 15 feed cylinder on the side of the piston rod and through 'said shuttle valve to the cylinder space of the feedextension cylinder on the side of the piston rod, and the effective areas of the piston of the feed-extension cylinder have such dimensions that when hydraulic fluid is 20 fed through the first feed line, the pressure of the 'hydraulic fluid acts on the feed cylinder and at the same time on both cylinder spaces of the feed-extension cylinder so that the forces created by the feed-extension cylinder and the feed cylinder are substantially equal.

In order that the invention may be more clearly ascertained, preferred embodiments will now be described by way of example with reference to the attached drawings, in which: Figure 1 illustrates a feed-extension cylinder arrangement according to a preferred embodiment of the invention as seen from the side of the feeding beam shown in a partial section; Figure 2 is a schematic sectional view of the feed-extension cylinder arrangement shown in Figure 1 in the transverse direction of the feed beam along line A-A indicated in Figure 1; \\MELBO1\lioeS\Vicky\Keep\speci\13877.95.doc 15/01/98 t.

n* 7 r <e 3A Figure 3 is a schematic view of the mounting of the end of the piston rod of the feed cylinder to the lower beam; Figure 4 is a schematic view of a hydraulic connection for the preferred embodiment of the arrangement according to the invention; and Figure 5 is a more detailed schematic view of another embodiment of the arrangement according to the invention.

Figure 1 shows a feed beam comprising an upper beam 1 and a lower beam 2. The upper beam 1 and the S.

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S S S 5 r~r \\HEtBOl\home$\Vicky\Keep\speci\13877.95.doc 15/01/98 WO 95/18913 PCT/FI95/00002 4 lower beam 2 are positioned mutually longitudinally slideably by means of slide rails la provided at the lower edge of the upper beam 1 and slide means 3 attached to the lower beam. The upper beam 1 is preferably made of an aluminium alloy by extrusion, its slide surfaces being preferably formed simultaneously.

The slide rails are provided with slide surfaces 4, usually steel strips or the like, for the slide means.

The slide means 3 in turn are preferably formed by aluminium profiles, to which slides shown in Figure 2 are attached. The slides are in contact with the slide surfaces 4. The slide means 3 in turn are attached to the lower beam 2 by means of bolts 5. At the front end of the lower beam 2, the slide means extend substantially over the entire travel length of the upper beam 1, so that the slides support the upper beam over its entire length, while the aluminium profiles stiffen the low lower beam at the front end. If desired, the slide means 3 may extend over the entire length of the lower beam 2, and slides may be positioned within a desired portion of the aluminium profile.

A feed-extension cylinder 6 is provided below the upper beam 1, and the cylinder pipe of the feedextension cylinder is attached to the lower surface of the upper beam 1. The feed-extension cylinder 6 is preferably fixed to the upper beam 1 rigidly and immovably so that it cannot turn relative to it. A piston rod 7 of the feed-extension cylinder 6 in turn is attached at its end to the rear end of the lower beam 2. The feed-extension cylinder 6 may be fixed e.g. by flanges 6a attached to the cylinder pipe of the cylinder 6 and bolts 8 driven into the flanges through the bottom plate lb of the upper beam 1. The figure also shows a rock drill 9 intended to move along the upper beam, and a drill carriage 10 mounted WO 95/18913 PCT/FI95/00002 in a manner known per se slideably along second slide rails ic provided at the upper edge of the upper beam 1. To displace the rock drill 9 and the carriage 10, a feed cylinder 11 is provided within the upper beam 1, and an idler wheel 12 is connected to the cylinder pipe of the feed cylinder 11. A feed wire 13 in turn passes around the idler wheel 12. It is connected both to the drill carriage 10 and to the upper beam i. This kind of feed cylinder/wire structure is as such wellknown, and therefore it will not be described more closely herein. When pressure fluid is introduced into the feed cylinder 11, its piston rod is expelled and the cylinder pipe moves towards the front end of the upper beam, thus pushing the feed wire 13 ahead of it by means of the idler wheel, and so the rock drill 9 and the carriage 10 move on at a speed twice as high as that of the idler wheel 12. Correspondingly, when the piston of the feed cylinder is retracted, the rock drill moves to the rear portion of the upper beam 1 in a manner known per se. The figure also shows a travelling centralizer 14 provided for a drill rod at the front end of the upper beam 1, and a front centralizer 15 at the front end of the lower beam 2. Such centralizers are fully known per se, and are not essential to the present invention, wherefore they will not be described more closely herein.

Figure 2 is a sectional view of the feed beam structure shown in Figure 1 along line A-A. As appears from Figure 2, the lower beam 2 is formed by vertical side portions 2a and a transverse bottom plate 2b positioned between the side portions. A chute-like space 2c is defined between the side portions and the bottom plate. The feed-extension cylinder 6 is positioned in the space 2c below the upper beam i. As appears from Figure 2, the upper edge of the cylinder pipe of the WO 95/18913 PCT/FI95/00002 6 feed-extension cylinder 6 is provided with a fixing flange 6a, which fixes the cylinder at its both ends immovably to the upper beam i. In this way, the feedextension cylinder 6 and its piston rod 7 remain all the time between the upper beam 1 and the lower beam 2, being thus protected. The aluminium profiles 3 having slides 3a inside them are attached by means of the bolts 5 to the edge flanges 2d provided at the edge of the side portions of the lower beam 2. The slides 3a in turn are in contact with the slide surfaces 4 of the slide rails la of the upper beam 1 so that the upper beam and the lower beam slide in close contact with each other.

Figure 3 schematically illustrates one way of mounting the end of the piston rod 7 of the feedextension cylinder 6 longitudinally immovably with respect to the lower beam 2 while however allowing it to "float" in the transverse direction. This is done e.g. by fixing a connection piece 7a, such as a round or angular flange or plate, to the end of the piston rod 7. The connection piece in turn is mounted to an abutment 16 attached to the end of the lower beam 2.

The abutment is provided with a slot 16a, into which the connection piece 7a can be fitted transversely movably, and with a groove 16b for the piston rod 7, which can move in the groove in the transverse direction of the lower beam 2.

Figure 4 is a schematic view of a hydraulic connection suitable for operating the feed beam according to the invention, where the feed-extension cylinder 6 and the feed cylinder 11 are interconnected hydraulically so that their forces will be equal. This is realized by connecting the two cylinder spaces of the feed-extension cylinder 6 in communication with a feed line for pressure fluid during the drilling, so WO 95/18913 PCTFI95/00002 7 that fluid introduced through the line 17 is admitted into both the feed-extension cylinder 6 and the feed cylinder 11 into a space which is not occupied by the piston rod. From the line 17, the hydraulic fluid is able to flow through a shuttle valve 18 into the feedextension cylinder space on the side of the piston rod 7. When an exhaust line 19 is closed by the shuttle valve 18, the hydraulic fluid acts on the feedextension cylinder 6 in proportion to the effective areas of its piston. Accordingly, when the areas are selected suitably, the force will be equal to that of the feed cylinder 11. Correspondingly, when hydraulic fluid is introduced through the line 19 into the feedextension cylinder 6 into the space on the side of its piston rod and into the feed cylinder 11 into the space on the side of its piston rod, the shuttle valve 18 closes the connection to the line 17, and both of the cylinders move into their most retracted position so that the upper beam will move into its rearmost position with respect to the lower beam and the rock drill 9 returns to the rear end of the upper beam 1.

Figure 5 shows a feed beam similar to that shown in Figure 1, and its reference numerals correspond to those of Figure 1. An essential difference is, however, that the cylinder pipe of the feed-extension cylinder 6 is secured immovably to the lower beam 2, and the rod 7 of the feed-extension cylinder 6 is attached to the upper beam 1 movably in its transverse direction but substantially immovably in the longitudinal direction. The operation and reference numerals of the equipment correspond to those of Figure 1 except that in this case the cylinder pipe of the feed-extension cylinder 6 remains immovable when the upper beam 1 moves with respect to the lower beam 2.

The invention has been described above and shown WO 95/18913 PCT/F195/00002 8 in the drawings by way of example, an'it is not in any way restricted to the example. The feed mechanism of the rock drill need not be a feed cylinder/wire mechanism, but it may also be a feed cylinder mechanism of some other type, even though the cylinder/wire mechanism is advantageous in use.

Claims

9- THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS: 1. A feed-extension cylinder arrangement in a feed beam for a rock drill, the feed beam comprising a lower beam and an upper beam, the lower beam having two vertical side portions and a transverse bottom between the side portions so that the side portions and the bottom define between them a chute-like space, upon the open side of which the upper beam is mounted longitudinally slideably with respect to the lower beam; and a feed-extension cylinder connected to act between the upper beam and the lower beam, the feed-extension cylinder being mounted in the chute-like of the lower beam below the upper beam, and the cylinder pipe of the feed-extension cylinder and its 15 piston rod being connected to act between the upper beam and the lower beam so that when the feed-extension cylinder is extended, it displaces the upper beam towards the front end of the lower beam, and when the feed-extension cylinder is shortened, it displaces the upper beam towards the rear 20 end of the lower beam, wherein the cylinder pipe of the feed-extension cylinder is fixed to the lower beam or to o'i the upper beam immovably with respect to it, and the piston rod is correspondingly connected at its end to the front end of the upper beam or to the rear end of the lower beam 25 so that it is able to move in the transverse direction of the upper beam or the lower beam, respectively, but substantially immovably in its longitudinal direction. 2. A feed-extension cylinder arrangement as claimed in claim 1, wherein a feed cylinder for the rock drill and the feed-extension cylinder are hydraulically interconnected so that the feed forces of the feed cylinder and the feed-extension cylinder are equal throughout the drilling process. 3. A feed-extension cylinder arrangement as claimed in claim 2, wherein a first feed line for hydraulic fluid \\MELB01\home$\Vicky\ieep\speci\l3877.95.doo 15/01/98 LJ' 'Aercy~ 10 is connected to both the feed cylinder and the feed- extension cylinder to a cylinder space unoccupied by the piston rod, said first feed line is also connected through a shuttle valve to the cylinder space of the feed-extension cylinder on the side of the piston rod, a second feed line for pressure fluid is connected to the cylinder space of the feed cylinder on the side of the piston rod and through said shuttle valve to the cylinder space of the feed- extension cylinder on the side of the piston rod, and the effective areas of the piston of the feed-extension cylinder have such dimensions that when hydraulic fluid is fed through the first feed line, the pressure of the hydraulic fluid acts on the feed cylinder and at the sazme time on both cylinder spaces of the feed-extension cylinder 15 so that the forces created by the feed-extension cylinder and the feed cylinder are substantially equal. 4. A feed-extension cylinder arrangement substantially as hereinbefore described with reference to 20 figures 1 to 4 or to figure 5 of the accompanying drawingL o Dated this 15th day of January 1998 TAMROCK OY By their Patent Attorneys S 25 GRIFFITH HACK Fellows Institute of Patent Attorneys of Australia \\HELBOl\homeS\Vicky\Keep\6peci\13077.95.doc 15/01/98