US2708101A - Feeder device for rock drilling machines - Google Patents

Description

w. LICHT-BLAU FEEDER DEVICE FOR oar: DRILLING MACHINES med Nov. '14, 1950- May 10, 1955 4 She ets-Sheet 1 Jn ven for: mm, M

by 124m Attorney May 10, 1955 w. LICHTBLAU 2,708,101

FEEDER DEVICE FOR ROCK DRILLING MACHINES Filed Nov. 14, 1950 4 Sheets-Sheet 2 Fig.3

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A Horney May 10, 1955 w. LICHTBLAU FEEDER DEVICE FOR ROCK DRILLING MACHINES Filed Nov. 14, 1950 4 Sheets-Sheet 3 Jn ven for. Amt/M 14w W 7 Mamb A Horney May 10, 1955 w. LICHTBLAU 2,708,101

FEEDER DEVICE FOR ROCK DRILLING MACHINES Filed Nov. 14, 1950 4 Sheets-Sheet 4 FIG.8

INVENTOR WILHELM LICHTBLAU I 444 A une-4%..

ATTORNEY United States Patent 0 FEEDER DEVICE FOR ROCK DRILLING MACHINES Wilhelm Lichtblau, ,Wilhelmshaven, Germany Application November 14, 1950, Serial No. 195,562

3 Claims. (Cl. 255-45) The invention relates to a feeder device for rock drilling machines, particularly for drill hammers, which are held on the rock face in a pre-bored hole or are pressed against the rock face in any other suitable manner. These devices consist substantially of a guide member on which the drill hammer slides in order to be pressed 1 against the work face by means of a pressing-on device.

In the previously suggested devices of this kind the feed of the drill hammer is effected by feeder cylinders or by means of a ratchet gear operating in one direction only under the vibrations of the drill hammer i. e. substantially rigidly automatic, which has the disadvantage that the feed does not adapt itself to variations in the properties of the rock to be drilled. It is adjusted to a medium value which is too low for soft rock and is too high for hard rock; hence all the disadvantages in relation to the impossibility of always attaining the optimum drilling effect or, in the converse case, resulting from overstraining. Furthermore the devices as hitherto proposed do not permit the feed of the drill hammer during the working operation to be controlled. Finally, owing to all these facts, i. e. to the impossibility of controlling the drilling process, even the usual attachment of the fixing device in the pro-bored hole by means of expanding plugs is quickly loosened and detached.

Due to all these disadvantages holding devices of this kind have not been used in practice as much as they would have been expected to, although they would result in a considerable relief from physical strain of the operators; instead the miners are prepared to put up with physical strain in order to compensate for the lack of adaptability 4.;

of the feeder devices hitherto proposed to the conditions prevailing in the actual case or to varying conditions, repectively.

The invention provides a feeder device, particularly for rock drill hammers, which adapts itself automatically to the varying conditions as regards the properties of the rock etc., and which consequently has the advantage of relieving the operator of the necessity of manually holding the drill hammer against the work face.

This advantage is attained according to the invention in that the feed and/ or bearing pressure of the drill hammer is effected by an elastic cable, for example by a cable composed of rubber cords, which owing to its property and arrangement exerts on the drill hammer a substantially uniform but elastic feed pressure capable of adapting itself to the properties of the rock and of the order of magnitude required.

One end of this rubber cable of e. g. 0.8 to 1 inch diameter is fixed to a rotatable drum which is operated by a ratchet gear and thus allows the tightening and retightening of the cable, and the latter is passed from said drum over return pulleys in two strands via an oblique pulley arranged on the slide for the drill hammer, which is accordingly under the feeder pressure-or rather pull in the present caseadjustable by means of the ratchet gear and capable of being varied even during operation. By this arrangement of the cable and its being wound on iii ice

the said drum (which is constructed in a special manner to be described later) an accumulation of force is attained which results on the one hand in an almost uniform feed during the entire drilling operation and, on the other hand, cushions the reaction jolts owing to the resiliency of the rubber cable determined by the length of its many turns. A non-elastic pull-back rope independent of the elastic feeder cable and attached on the one hand to the slide and, on the other hand, to a drum subjected to spring action and partly Wound upon the latter, is continuously further tensioned against the action of said spring during the feed of the drill slide, and after the termination of the drilling operation pulls the drill slide back into its initial'position as soon as the rubber cable is relaxed by disengaging its drum, and winds itself upon the latter.

It is not necessary that the entire pull rope, which with a length of the slide guide corresponding to the depth of the bore holes in question of more than 2 yards would have a length of more than 11 yards without considering the part to be wound upon the tensioning drum, be made as a rubber rope, and it can be composed of resilient sec: tions-rubber ropeand of nonresilient sections of ordinary steel cable, if desired.

In a further development of the invention the weight of the slide and of the drill hammer resting thereon is adjustably compensated to a great extent by an arrangement of guide pulleys which lead the resilient cable to the return-roller arranged on the slide and transmitting the feed, under circumstances over-compensating to such an extent that the slide is slightly lifted off its guide and the latter is relieved.

A particularly important feature of the invention consists in that by appropriate construction of the winding-0n and tensioning-drum for the rubber cable the elasticity of the wound-on portion thereof, too, is utilised. This is attained by forming the supporting surface for the turns of the rope on the circumference of the drum by a plurality of rings, lying side by side and rotatable independently of the drum, so that the turns of the rubber cable wound upon it do not lie immovably on the circumference of the drum but can twist relatively to one another, yieiding to their elasticity. 1

Further features of the invention consist in the attachment of the whole device to the rock face by plugs con structed in a novel manner, which are in an angular position with respect to one another, so that any pulling off from the rock face of the holding device is reliably prevented.

Alternatively it is possible according to afurther feature of the invention to press the whole device, instead of attaching the same by means of plugs to the rock face, against the latter by means of a support device, and there by to dispense with the drilling of pro-bored holes for the plugs and with the latter too, while still reliably supporting the device.

In the accompanying drawing in which several embodiments of. the invention are illustrated by way of example:

Figure 1 is a perspective view of the complete device according to the invention.

Figure la is an enlarged sectional view of the outer ends of the guide rods and associated drum structure;

Figure 2 shows diagrammatically the pulling cable arrangement,

Figure 3 shows on an enlarged scale a side elevation of the arrangement of the pulley by which the pull is transmitted to the slide, and of the guide pulleys for guiding the cable on to the said pulley.

Figure 4 is a plan view of Figure 3,

Figure 5 shows in side elevation and on an enlarged scale the construction of the tensioningand winding-on drum for the cable.

Figure 6 shows, also on an enlarged scale, one of the plugs to be used in pairs,

Figure 7 shows the pressing-on device to be used as an alternative to the plugs, if desired.

Figure 8 is an enlarged side elevation of the body or frame which is disposed adjacent the rock face, and associated members, and

Figure 9 is a top plan view of the structure shown on Figure 8.

In Figure 1, the drum 2 for tensioningand winding-on the cable is rotatable by means of the lever 1 through a ratchet gear 3 as will be described in more detail with reference to Figure 5.

The drill slide 4 is shiftably supported on two guide rods 9, the rear ends of which have brackets 9a between which is rotatably mounted a drum 6. The forward ends of the rods 9 are attached to a body 12. The latter is provided with a pair of laterally spaced arms 16 to which braces 17 are attached said braces being in turn connected to the guide rods 9. The braces 17 are rigidly secured to brackets 17a which are welded to the under sides of the guide rods 9 respectively. The drum 6 is under the action of a torsion spring 6a arranged inside i the drum. The steel cable 5 is attached, on the one hand, to the said drum 6 and, on the other hand to the slide 4, the end wound upon the drum being drawnofi the latter against the action of the torsion spring while tensioning the latter, when the slide performs its feed motion, and pulls the slide back by the action of the said spring after the termination of the drilling operation.

The body 12 has slotted lateral projections 18 which serve for the attachment of the plugs 15 in a manner hereinafter described. The two vertical arms 16 of the body 12 are connected with one another by a cross beam 19, through which passes an abutment screw 21, operated for example, by a hand wheel 20. A similar adjustable abutment screw 21a is arranged on the level of or slightly above the plugs 15 and between the latter on the body 12.

From the above description and particularly from an inspection of Figures 8 and 9, it will be understood that the body or frame 12 comprises a pair of laterally spaced upright arms or projections 16 which are integrally connected near the lower ends by a transverse beam or brace 1 19 and at the upper ends by a transverse brace 19a. Integral laterally extending arms or projections 18 are at the upper end portions of the vertical arms 16 respectively and extending rearwardly from the upper ends of the vertical arms are integral brackets 2a between which z the drum 2 is mounted. Also extending rearwardly from the vertical arms 16 below the brackets 2a are integral brackets 26a between which are disposed pulleys or sheaves 26 (hereinafter described), supported on a suitable shaft. The ratchet wheel 3 is on the outer side of one of the'brackets 2a suitably fixed to the drum 2 and a pawl 2b is pivoted to such bracket, the pawl having an integral handle for manual operation thereof.

On the slide 4 are mounted guide pulleys 7, pivotable and in a vertical plane for adjusting their vertical position, and a tension pulley 8 arranged at about 45 to the horizontal. On the shaft of the drum 6 are mounted pulleys 24 for cable 25, said pulleys being rotatable independent of the drum.

Figure 2 shows in detail the diagram of the resilient cable 25 which consists preferably of a plurality of rubber cords. The ends of the cable are attached to the drum 2, at two points adjacent the flanges of the said drum and spaced apart from one another; from there they are passed over the cable pulleys 24, then over the return pulleys 26 arranged on the frame 12 and over the guide pulleys 7 and around the tension pulley 8 on the slide 4. Accordingly it is clear that the tension of the cable caused by turning the drum 2 by means of the lever 1 and of the ratchet 3, is transmitted to the pulley S and from there to the slide. By actuating the lever 1, the drum 2 can be rotated for increasing the tension on the rubber cable 25 during the operation of the drillcarrying slide 4. For example, as the slide 4 more closely approaches the rock face, the drum can be rotated for creating greater tension on the rubber cable. However, this is not ordinarily necessary since the rubber cable exerts a constant tensile force through the particular range afforded by the guide rods 9. Furthermore, substantial compensation for the slide movement is effected by the relatively large length of the cable 25 due to the plurality of runs which are provided by passing over the several sheaves.

Figures 3 and 4 show in detail how the pulley 8 is connected by an oblique arm 23 with the slide 4, and moreover show the arrangement for adjusting the vertical portion of the guide pulleys 7. As will be seen the attachmcnt brackets of the pulleys are pivoted at 22 to the body of the slide and by means of bolts 28 are shiftable and fixable in an arc-shaped slot 27. By such adjustment the point of attack of the tensile force on the cable can be so varied that the weight of the drill slide and of the drill hammer is compensated to a great extent and that. as it were, the drill slide with the hammer resting on it is lifted off the guides 9. Point of attack of the tensile force is the point on which any object which is drawn is secured to another object. The lifting of the drill slide and hammer olf the guides can take place under the effect of the tension, because such tension is not exerted in an absolutely parallel direction of the guides for the slide, and, of course, by the component of the tension acting upon the slide, etc., the component of gravity under which the slide rests upon its guides is diminished.

As shown in Figure 5, a plurality of loose rings 10 are arranged on the circumference of the drum 2 and rotatable independently of the drum and forming the supporting surface for the cable. Accordingly relative movements of the individual turns of the cable resting on said rings with respect to one another are made possible, and thereby an exploitation of the elasticity of the whole length of the cable wound upon the drum.

Figure 6 shows an embodiment of the plugs to be used in pairs which, attached in the slotted lateral projections 18 (Figure l), are slightly tilted so as to converge towards the central axis of the whole device so that they jam in their bore holes under the effect of the reaction forces acting on them, and are thus made secure.

These plugs consist of two channel section chuck portions 14 which, after having been driven in, hold the bolt 15 of the plug in the bore hole into which it has been previously inserted; such bolt is per se of a smaller diameter than the bore hole but is slightly thickened conically at its end.

The pull which is excrted by the reaction forces on to the bolt 15 in a direction deviating from the axial direction of the said bolt owing to the tilted position of the bolts, presses the chucks 14 against the walls of the pro-bored holes, thus constantly improving the frictional lock thereof. A tightening nut 11 is prevented by the spring 13 from loosening in the slotted guide 18 on the frame body 12, and by a pull on the bolts 15 presses the chucks 14 against the walls of the bore holes when they tend to yield. The bolt 15 is guided by projecting pins 15 in the gaps between the two chuck halves. The plugs are laterally shiftable in the slotted guides 18.

The pressing-on device illustrated in Figure 7 makes it possible to dispense with the said plugs. It consists in two supporting legs 2? articulated to one another in an angular position relative to each other. A toggle 39 connects intermediate portions of the 'legs 29. By the pressure exerted on to this toggle by means of hand wheel 31 the device, which bears with one of its legs at 32 on to the floor or into a notch of the floor and which, on the, other hand, is articulated at 33 to the body 12, is pressed against the said body, whereby the latter and/or the adjustable spur-and-spindle abutment 21 are pressed against the rock face. Thereby, an absolutely reliable support of the holding device is achieved.

The preferred embodiment of the invention as de scribed hereinabove in detail is of course given merely by way of example, and numerous modifications are possible, without departing from the scope of the invention as defined by the appended claims.

I claim:

1. A feeding device for rock drilling machines comprising a supporting frame work for abutting at one end against the face of the rock to be drilled, a guide secured at one end to said frame work and extending outwardly therefrom, a drilling machine slide shiftable on said guide, a pair of sheaves on said frame work, a pair of sheaves on the outer end portion of said guide, a pair of sheaves on said slide, a tension sheave on said slide with its axis in rear of and transverse to the axis of said first slide sheaves, a cable tension adjusting device on said frame work and operable to effect movement of the cable over said sheaves, a cable of rubberlike material having its ends anchored to said adjusting device and successively reeved over the sheaves on said guide, the sheaves on said frame work, the first slide sheaves, and finally the tension sheave on the slide, thereby constantly to tension the slide toward the rock to be drilled, drum means on the outer end of the guide, a retracting cable connecting said drum and slide, and torsional spring means tending to wind said retracting cable on the drum.

2. A feeding device for rock drilling machines comprising a supporting frame work for abutting at one end against the face of the rock to be drilled, a guide secured at one end to said frame work and extending outwardly therefrom, a drilling machine slide shiftable on said guide, a pair of sheaves on said frame work, a pair of sheaves on the outer end portion of said guide, a pair of sheaves on said slide, a tension sheave on said slide with its axis in rear of and transverse to the axis of said first slide sheaves, a cable tension adjusting device on said frame work and operable to effect movement of the cable over said sheaves, a cable of rubber-like material having its ends anchored to said adjusting device and successively reeved over the sheaves on said guide, the sheaves on said frame work, the first slide sheaves, and finally the tension sheave on the slide, thereby constantly to tension the slide toward the rock to be drilled, said cable tension adjusting device comprising a drum, ratchet and pawl means for manually operating the drum for regulating the cable tension, and a plurality of rings arranged side by side and rotatable independently on the drum for enabling relative movements of the cable turns resting thereon.

3. A feeding device for rock drilling machines comprising a supporting frame work for abutting at one end against the face of the rock to be drilled, a guide secured at one end to said frame work and extending outwardly therefrom, a drilling machine slide shiftable on said guide, a pair of sheaves on said frame work, a pair of sheaves on the outer end portion of said guide, a pair of sheaves on said slide, a tension sheave on said slide with its axis in rear of and transverse to the axis of said first slide sheaves, a cable tension adjusting device on said frame work and operable to effect movement of the cable over said sheaves, a cable of rubber-like material having its ends anchored to said adjusting device and successively reeved over the sheaves on said guide, the sheaves on said frame work, the first slide sheaves, and finally the tension sheave on the slide, thereby constantly to tension the slide toward the rock to be drilled, means for adjustably mounting the slide sheaves for compensating for the weight of the slide and drilling machine carried thereby, said mounting means including sheave attaching brackets pivotally mounted on said slide, and means for holding said brackets in adjusted position.

References Cited in the file of this patent UNITED STATES PATENTS

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