US2789789A - Rock drills - Google Patents

Description

L. LEA, JR

ROCK DRILL-S April 23, 1957 3 Sheets-Sheet 1 Filed July 3, 1953 INVENTOR- L uZ eLea (In,

ATTORNEY L. LEA, JR

ROCK DRILLS April 23, 1957 3 Sheets-Sheet 2 Filed July 3, 1955 INVENTOR ZuZ eLmz, .Jn,

ATTORNEY L. LEA, JR

ROCK DRILLS April 23, 1957 3 SheecsSheet .3

Filed July 3, 1953 ATTORNEY United States Patent i ROCK DRHLS Luke Lea, In, Dayton, Tenn.

Application July 3, 1953, Serial No. 365,936

13 Claims. (Cl. 255-51) This invention relates to rock drills, and more particularly to drill-steel centralizers for hammer rock drills.

In mounted rock drills of the drifter type, the drill bit is carried by an elongated rod or drill steel that is supported at its rear end by a drill hammer motor that is movably mounted on a guide shell that resembles an elongated boom. In operation, the hammer motor is moved along the guide shell as the bit drills into the rock.

Due to the length of the drill steel, it tends to flex and to counteract this, drill steel guides or centralizers are mounted on the forward end of the guide shell to center the drill steel and bit during the starting or spotting of a drill hole. Once the drill hole is started, the bore walls function to centralize the drill steel, and the centralizers, which are usually a pair of levers having guide portions that jointly form a guide, are moved out of the way to permit passage of the drill hammer motor to the full length of the guide shell.

In many cases, the drill steels must be quite long and the guide shell boom must be of substantially equal length. as the centralizers are usually adjacent the outer or front end of the boom-like guide shell, considerable difiiculty is experienced in properly positioning the drill steel and actuating the centralizers. In actual practice, the operator climbs out to the end of the guide shell, and while balancing himself, he lifts the drill steel to central position with one hand and swings the centralizer levers into position and locks them with the other hand. After the drill hole is started, the operator again climbs out on the guide shell and manually releases and swings the centralizer levers out of the way of the hammer motor.

Having in mind the defects of the prior art apparatus, it is the object of the present invention to provide an improved drill steel guide or centralizer which overcomes the principal disadvantages of the prior art devices.

It is another object of the present invention to provide a drill steel centralizer with improved operating means for moving the centralizer between steel guiding and nonguiding positions.

It is still another object of the present invention to provide a drill steel centralizer with improved operating means for moving the centralizer between guiding and open positions and which also functions to lock the centralizer in guiding position.

it is yet another object of the present invention to provide in conjunction with a drill steel centralizer, means for automatically positioning the drill steel to be guided by the centralizer.

it is a further object of the invention to provide a drill steel centralizer with means for automatically positioning the drill steel in position and then guiding the positioned steel.

It is a still further object of the invention to provide in conjunction with a drill steel centralizer means for automatically positioning the drill steel and remote means for operating the centralizer and positioning means.

It is yet a further object of the invention to provide a drill steel centralizer and steel positioning means ineluding controls therefor having simplicity of design, economy of construction and efficiency in operation.

I The foregoing objects and others ancillary thereto are preferably accomplished by providing in conjunction with a drill steel centralizer a lifting means operable to lift the drill steel to centralized position before actuation of the centralizer to guiding position and remote control means for the lifting means and centralizer.

The lifting means preferably comprises a cam means, and in a preferred form, this cam means comprises cams formed on the levers of a centralizer, although a separate cam may be employed. Alternatively, fluid power means may be employed. Thecentralizer levers are remotely actuated by a linkage or lever mechanism and preferably by cams which lock the levers in guiding position.

The novel features that are considered characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and its method of operation, together with additional objects and advantages thereof, will best be understood from the following description of specific embodiments when read in connection with the accompanying drawings, wherein like reference characters indicate like parts throughout the several figures, and in which:

Figure 1 is a diagrammatic side view in elevation of a typical mounted rock drill of the drifter type;

Figure 2 is a diagrammatic view in perspective of a rock drill of the drifter type with a drill steel positioning means and centralizer in accordance with the present invention;

Figure 3 is an enlarged end view of the rock drill shown in Figure 2 and showing the centralizer in accordance with the present invention in elevation;

Figure 4 is a side view of the centralizer shown in Fig ure 3;

Figure 5 is a side view of a modified form of steel positioning means and centralizer actuating cam particularly adapted for adaptation to existing centralizers;

Figure 6 is a top plan view of Figure 5;

Figure 7 is an end view in elevation. of a modification of a combined centralizer and steel position cam of the type shown in Figure 3;

Figure 8 is a top plan view of Figure 7;

Figure 9 is a top plan view of a fluid powered steel positioner and centralizer, and

Figure 10 is an end view in elevation of Figure 9.

Referring now to the drawings, specifically to Figure l, a rock drill of the drifter type comprises a drill hammer motor M which supports one end of the drill steel or rod S that carries the drill bit D at its free end. The motor M is movably supported by a boom-like guide shell G and is advanced therealong as the drill D penetrates the rock. The guide shell G is usually mounted by a swivel or universal joint structure I on a crane-like boom B that is normally carried by a truck or other support, a platform P being supported by the boom B adjacent the rear end of the guide shell G to accommodate the operation.

The drill steel S is relatively long and has a tendency to flex or sag at its free end, as indicated in broken lines. Accordingly, it is guided at its forward end by a centralizer C which comprises a pair of levers pivoted on opposite sides of the guide shell G for movement between open positions-out of the path of the motor M and closed or guiding positions in which they support or guide the drill steel S. The centralizer is closed to guide the drill steel at the start of drilling operations, and then after the drill hole is of sufficient depth to support and guide the drill D, the centralizer is opened to permit the passage of the motor M for the full length of the guide shell G.

In actual operation, it is the practice of the operator to climb out on the guide shell'G and lift the drillsteel'S with one hand and manipulate the centralizer levers with the other hand,.all whilebalancing himself out on the free end of the guide shell. This difficult and dangerous operation is eliminated by the present invention, which resides in providing remotely operated means for lifting the drill steel S into position. and actuatingthe centralizers to close them about the steel in guiding position as well as opening the centralizers to release the steel.

According to a preferred modification of the invention, referring to Figures 2-4, the centralizer comprises a pair of levers 11 mounted on a pivot 12 on. the outer end portion of the guide shell G, and each of said levers 11 carries the usual semi-circular guide portions 13 which cooperatively form a guide for the drill steel S, as shown in broken lines in Figure 31 The levers may be biased to open position by-a suitably arranged spring 14.

In this preferred modification, the centralizer levers 11 are per se adapted to lift the drill steel S from its sagged position, as shown in full lines in Figure 3 to its centralized position, as shown in broken lines. The lifting of the drill steel is effected by providing the upper or facing edges of the levers 11 in the form of earns 15 which jointly engage the drill steel S in sagged position and cam it upwardly as the centralized levers 11 are swung to closed position. The earns 15 are preferably arranged to form in open position a V for catching the steel S and preventing possible lateral displacement thereof.

The centralizer levers 11 are actuated to closed position by remote control mechanism comprising a pair of cams 16 which are rigidly connected and journalled by a pivot 17 on the outer or free end of the guideshell G to engage and cooperate with the outer edges 18 of the centralizer levers 11. The cams 16 are actuated by a link 19 pivotally connected at one end to one of the cams and at the other end to a handle 20 pivotally mounted in a bracket 21 at the other or inner end of the guide shell. The pivotal mounting of the handle 20 is such as to permit the swinging of its pivotal connection with the link 19 to an over-center position, as shown in broken lines in Figure 2, to secure the cams 16 in upper position, Figure 4. The cams 16 thus lock the centralizer levers 11 in closed guiding position.

While the foregoing embodiment is particularly adapted for new fabrication, a modification of the invention as shown in Figures and 6 is particularly adapted for application to existing installations, In this case, the pair of cams 16a are adapted to cooperate with the outer corners or edges 18a of a pair of standard centralizer levers 11a,

having standard guides 13a, and a drill steel lifting cam 25, having a yoke 26 for nesting the drill steel S, is disposed between and fixed with the cams 16a.

The cams 16a may be remotely actuated by the link 19 and the centralizer levers 11a may be spring biased to open position in the usual manner when the cams 16a are swung to open position, as shown in phantom lines in Figure 5. In these standard centralizer constructions, as illustrated in Patent No. 2,350,660, for example, the standard levers have a limited outward or opening movement so that they do not drop sufliciently to block or jam the cams 16a and prevent their swinging to closed position. Upon pulling the link. 19 to pivot the cams 16a to closethe centralizer. levers 11a, the yoke 26 straddles the drill steel S and the cam or arm'25 is swung up to lift the drill steel S to central position prior to the complete closing of the levers 11a by the cams 16a.

Still another modification of the invention is shown in Figures 7 and 8, wherein the centralizer levers 11 are similar to the levers 11, in that they have the guides 13 and the cams for biasing the drill steel S into the guides 13. In this modification, however, the levers 11 are shown as being separately mounted. on .individual pivots 12" and the levers are actuated by a pin 30, on one:

4 lever riding in a cam slot 31 in the other lever and remote actuating means for positively swinging one of the levers in both open and closing directions.

The lever moving means comprises an elongated crank shaft 32 journalled on the guide shell G with a crank handle 33 at one end and a crank arm 34 at the other end and connected by a link 35 to one of the levers 11'. A latch hook 36 is pivotally mounted on the guide shell G and biased by a spring 37 to engage and hold the handle 33 when it is swung down to swing the levers 11 to closed position, as shown in phantom lines in Figure 7. Thus, by swinging the handle 33, the crank arm 34 actuates through the link 35 one of the levers 11' which in turn actuates the other lever 11' by means of the pin 30 and slot 31 connection therebetween.

A further modification of the invention embodying fluid power actuating means is shown in Figures 9 and 10. In this instance, thecentralizing levers 11b may be of a usual type having lower extensions 40 whichare connected by universal joints41with links 42 that are jointly connected by a'pivot 43 to the piston rod 44 of a fluid power cylinder 45 whose piston 46 may be biased in one direction by a spring 47. The cylinder 45 is supported by a plate 4-8 on the guide shell G and having a slot 49 in which the link pivot 43 is slidable.

Another fluid power cylinder 50 is mounted vertically on the end of the guide shell G, and this cylinder has a piston 51 which is spring biased downwardly with a rod 52 extending through the upperend of the cylinder and carrying a yoke 53 for supporting and lifting the drill steel S. A fluid supply line-54, controlled by a valve 55, is connected to the cylinder 45 and another line 56 controlled by a valve 57 is connected to the cylinder 50. The lines 54 and 56 are connected to a master control valve 58 which is connected with a fluid pressure line 59 and a discharge line 60.

In operation, with the centralizing levers 11b in open position and the yoke 53 in lowered position due to the spring retraction of the pistons 46 and 51, the control valves 55 and 57 are both closed and the master valve 58 is then opened to supply pressure fluid from the line 59 to the. lines 54 and 56. The control valve 57 is then opened to supply fluid to the cylinder 50 and lift the piston 51 to raise the yoke 53 and lift the drill steel S to central po'sition. The control valve 55 is then opened to supply fluid to the cylinder 45 and actuates the piston 46 to swing the centralizing levers 11b to closed position, as shown in phantom lines in Figure 10. The control valve 55 is then closed to trap the fluid in the cylinder 45 to hold the centralizer levers 11b in closed position, whereupon the master valve 58 may be actuated to shut off the pressure line 59 and open the discharge line 60. The spring actuation of the piston 51 will then force the fluid from the cylinder 50 back through the line 56 and discharge line 60, the yoke 53 being lowered out of the way. After the drill hole is spotted sufliciently to guide the drill steel '8, the control valve 55 is opened and the piston 46 retracted by the spring 47 to open the levers 11b and force the fluid back through the line 54 to the discharge line 60. As a precautionary action, the control valves 55 and 57 may be closed after the fluid is discharged from their respective lines 54 and 56.

Although certain specific embodiments of the invention centralized. position. to be: guided by;-saidguidezmeans.

when said guide means is in guiding position, and means on said support for actuating said centralizing and guide means.

2. A cen-tralizer for drill steels, as defined in claim 1, wherein said actuating means includes control means at a point remote from said guide means and centralizing means.

3. A centralizer for drill steels, as defined in claim 3, wherein said actuating means comprises a pair of fiuid power actuated devices, one of said devices being operatively connected with said guide means and the other of said devices being operatively connected with said drill steel centralizng means.

4. A centralizer for drill steels, as defined in claim 1, wherein said guide means comprises a pair of levers respectively carrying guide portion-s which cooperatively form a drill steel guide and said centralizing means comprises cams on the adjacent sides of said levers for c0- operatively camming a drill steel to said guide portions.

5, A centralizer for drill steels, as defined in claim 1, wherein said guide means comprises a pair of levers, said actuating means comprises a pair of cams enga ing opposite portions of said levers, and said centralizing means comprises a cam member fixed between said cams and movable therewith to engage and lift the drill steel.

6. A centralizer for drill steel-s, as defined in claim 1, wherein said guide means comprises a pair of levers pivotally mounted on said support, said actuating means comprises a pair of cams pivotally mounted on said support and engaging opposite portions of said levers, and said centralizing means comprises an arm fixed 'between and cams revolvable therewith to engage and lift the drill steel.

7. A centralizer for drill steel-s comprising a support, a pair of centralizing levers having guide portions and pivotally mounted on said support to swing transversely of said support between juxtaposed steel guiding positions and open positions, cams on the adjacent sides of said levers and overlapping transversely of said support to engage and support a drill steel that is sagged from centered position when said levers are in open positions and jointly operative to cam the drill steel upwardly to said guide portions in centered position, means for moving said levers, and means remote from said levers for actuating said moving means.

8. A centralizer, as defined in claim 7, wherein said moving means comprises a pair of cams in fixed relation pivotally mounted on said support on an axis transversely thereof and respectively engaging said levers, and

said actuating means comprises a link pivotally connected at one end to said pair of cams, and means remote from said cams and connected to the other end of said link for reciprocating said link to swing said cams.

9. A centralizer for drill steels, comprising an elongate support, means mounted on said support for cooperation with the normally unsupported end of a drill steel and movable between a first position wherein a drill steel is deflected by its own weight from a predetermined centralized position and a second position in which the drill steel is guidably supported by said means in its predetermined centralized position, said means engaging the drill steel during the movement of the means between the first and second positions to lift the drill steel to the predetermined centralized position, and means on said support for actuating the first mentioned means.

10. A centralizer for drill steels as defined in and by claim 9 wherein the first mentioned means includes a pair of pivotally interconnected levers having registrable free end portions forming a guide for supporting the drill steel in its centralized position.

.11. -A centralizer for drill. steels as defined in and by claim 9 wherein the first mentioned means comprises a pair of pivotally interconnected levers having registrable free end portions forming a guide for supporting the drill steel in its centralized position, said levers having adjacent inner edge portions engaging the drill steel for. moving it to the centralized position.

12. A centralizer for drill steels as defined in and I by claim 9 wherein the first mentioned means comprises a pair of pivotally interconnected levers having registrable free end portions forming a guide for the drill steel in its centralized position, and a lifting arm for raising the drill steel to its centralized position, said arm being rigid with the last mentioned means.

13. A centralizer for drill steels, comprising a support, means mounted on said support to engage and raise a drill steel to a predetermined centralized position and guidably support the same in such position, and means for actuating the first mentioned means.

References Cited in the file of this patent UNITED STATES PATENTS 2,365,680 Curtis Dec. 26, 1944 2,365,681 Gartin Dec. 26, 1944 2,365,686 Osgood Dec. 26, 1944 FOREIGN PATENTS 704,014 Germany Mar. 21, 1941

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