US 575970 A
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Description (OCR text may contain errors)
(No Model.) 5 sheets-sheet 2. J. MGCULLOCH.
Patented Jan. 26, 1897.
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'ROCK DRILL. Y 1 No. 575,970. Patented Jan. 26, 1897.
lA/3 I' f (No Model.) 5 Sheets-Sheet 4.
NQ. 575,970. v Patented Jan. 26, 1897.
` 1 5 sheets-sheet 5. `J. MOGULLOCH. BooK DRILLl No. 575,970. Patented 73.71.126,V 1897;4
M22 M i f M-Wr UNITED STATES PATENT OFFICE.
JAMES MCCULLOCH, OF VVOLVERHAMPTON, ENGLAND.
SPECIFICATION forming part of Letters Patent No. 575,970, dated January 26, 18.97'. Application filed September 30, 1895. Serial No. 564,185. (No model.) Patented in England September 17, 1894,11'0. 17,659.
' ain, residing at Bella Vista, Wolverhampton,
England, have invented certain new and useful Improvements in Rock-Drills, (for which I have obtained a patent in Great Britain, No. 17,659, dated September 17, 1894,) of which the following is a specification, reference being had to the accompanying drawings.
My invention relates to rockdrills, and comprises the improvements hereinafter described.
According to one part lof my invention I provide improved means for preventing the rotation of the twistbar during the backward stroke of the drill. The chief feature of this part of my invention relates to the provision of a twist-bar which can move axially as well as rotate in the drill-casing. It is by the axial movement of the twist-bar that the locking and unlocking of the said bar is effected.
According to other parts of my invention I provide an improved hol'der for the tool or bit and an improved device for easily and readily clamping the drill-casing at any desired angle.
My invention further comprises improved means for taking up slack due to the wear of the guides, feed-screws, and nuts of the rockdrill and for lessening the jar given to the operator by the shocks caused by the recoil of the drill.
My invention also has as a further object the construction of an improved valve for controlling the admission and exhaust of the working fluid. An important feature of'this part of my invention is the novel means which I employ to actuate the valve bythe working fluid in the cylinder.
In order that my invention may be clearly understood, I will now describe the same with reference to the accompanying drawings, in which- Figure lis a longitudinal central section through the drill-casing and parts contained therein. Fig. 2 is a transverse section taken on the line m a: of Fig. 1. Fig. 3 is a section on the line gj y, Fig. 2. Fig. 4 is a central longitudinal section through the rear end cover of the drill-casing, showing a modication hereinafter described. Fig. 5 His a longitudinal section through the cylinders for operating the valve, showing a modification hereinafter described. Fig. G is an elevation of my improved holder for the bit or tool. Fig. 7 is a section on the line e' ,e of Fig. (i. Fig. S is a central transverse section of my improved clamp. Fig. 9 is a plan, and Fig. 10 is Ia side elevation, of the clamp. Fig. 11 is a side elevation of a portion of the drillcasingshowing the device for preventing the wear of the guides. Fig. 12 is a transverse section of a modified form of valve and ports.
A is the drill-casing.
B is the twist-bar.
C is the piston of the drill.
I provide the rear end of the twist-bar with a head B, having teeth or projections B2, of any suitable form, secured thereto or formed integrally therewith. The said head works in a chamber A0, formed in the rear end cover of the drill-casing, and is capable of a limited axial movement in said chamber to lock and unlock the twist-bar. D is a toothed gear so fitted to the said rear end cover of the casing A that it cannot turn. It is adapted to engage with the teeth B2 when the twist-bar is in its rearmost position. IVhen the teeth B2 are engaged with the gear D, the twist-bar B cannot rotate in either direction.
At the commencement of the forward stroke of the drill the friction between the twist-bar B and the twist-nut F of the piston C, through which the twistbar passes, causes the latter to move forward, whereupon the teeth Bzbecome disengaged from the gear D and the twist-bar is then free to rotate. backward stroke of the drill the twist-bar is moved backward by the friction between it and the tw-ist-nut and its teeth B2 are caused to rengage with the stationary gear D, by which means the twist-bar is again locked. The drill will thus be caused to turn during its backward stroke, but will be free to move without turning during its forward stroke.
During the y I sometimes provide that the working fluid in the cylinder A shall assist the friction be'- tween the twist-nut F and the twist-bar B to disen gage the teeth B2 from and rengage the same with the stationary toothed gear D. For this purpose I provide suitable passages IOO or channels GG' in the casing. The channel G communicates with the port leading to the rear end of the cylinder and with the space between the gear D and head B', and the channel G' communicates with the cylinder at a point near the forward end thereof and with the chamber A0 at a point in front of the head B'. During the forward stroke of the drill the working fluid enters the passage G and acts on the rear face of the head B of the twist-bar, thus causing the said head and bar to move forward. During the backward stroke of the drill the fluid en ters the passage G' and acts on the front face of the twistbar head and so causes the bar to move backward. In this manner the twist-bar is locked during the backward stroke of the drill and unlocked during the forward stroke.
I sometimes form the teeth B2 on a conicalshaped head B', adapted to engage with a correspondingl y conical-shaped gear l), as sh own in Fig. 4.
My improved holder E, Figs. G and `7, for the tool, drill, or bit is provided with a keyway E', formed in the side of the socket in which the tool or bit H is held. The said keyway is made of increasing depth from the forward to the rear end, and it is fitted with a corresponding taper-key or wedge J. At the rear end of the key is an extension J', that projects through an' opening in the rear end of the holder. By striking the end of the extension J' the tool will be wedged tightly in the holder and be thereby very firmly held in position. It can be easily released again by striking the opposite end of the wedge, which projects from the front end of the holder.
Figs. 8, 9, and lO illustrate my improved clamp for easily and readily fixing a rockdrill to work at the different angles required. It is constructed as follows, that is to say: The clamp, which can slide and rotate on the bar or stand of the rock-drill, is furnished with a fixed jaw L and a movable jaw L', between which is received the projecting foot A2, Fig. l, provided on the cradle A2 of the rock-drill. A tapered keyway M is formed in the clamp, and a wedge N, sliding in the said keyway, serves for tightening the clamp on the bar. A stud N',which projects into a slotor groove N2 in the wedge N, serves to prevent the accidental loss of the wedge.
The hole P that receives the bar of the rock-drill is not truly cylindrical, but about half the area of the hole, and preferably that part in which the keyway for the wedge is located forms part of a cylinder of .larger diameter than the remaining portion of the hole, as shown in Fig. 8. The clamp can then be' readily applied to and tightened on a bar which is not truly cylindrical and which does not iit the hole P in the clamp. The necessity of having a truly cylindrical bar is thereby avoided. The jaw L' of the clamp is pivoted at L2 and is supported by a conical bolt O, which fits an inclined curved recess L2, formed in the back of the jaw. The ends of the bolt O are parallel or cylindrical and they are received in lugs or ears O', formed on the body of the clamp. One end of the bolt is screw-threaded and screws inio the corresponding lug O' for the purposes of adjustment.v Vhen the bolt is screwed into the clamp, the jaw L' is pressed tightly against the foot A3 of the cradle A2 of the drill,which is thereby rmly secured between the two jaws. By unscrewing the bolt O the foot of the cradle is again released.
O2 is a chain attached to the bolt to prevent loss of the same.
Figs. 2 and l1 show my improved means for taking up slack due to the wear of guides, feed-screws, and nuts in a rock-drill, and also for lessening or preventing the jar occasioned at the handle of the operating mechanism by the recoil of the drill. According to this part of m yimprovemen ts I construct the feed-nuts Q, Fig. 2, for the feed-screw R and the bushes Q' Q', Figs. 2 and 1l, for the guide R' of a conical shape and split them longitudinally at Q2. The said nuts Q and the bushes Q' Q' are received in corresponding conical recesses S S, formed in projecting parts or lugs T T of the drill-casing.- The large ends of the conical bushes and nuts face each other, as indicated with respect to the bushes in Fig. ll. I interpose a spiral spring U between the bushes Q' Q' on the guide R' and a similar spring between the feed-n nts Q, which are on the otherside of the casing and not shown in Fig. 11. The spiral springs U operate to deaden or diminish the force of the shock or jar and to automatically take up any slack in the aforesaid nuts and bushes.
In carrying into practice that part of my invention which relates to an improved valve for controlling the admission and the exhaust of the working fluid to the cylinder A' of the drill I construct the valve V, Figs. l and 2, of cylindrical form, and I arrange it to work in a cylindrical chamber W, formed in the drill-casing A. The axis of said chamber is preferably perpendicular to the direction of motion of the piston C.
The chamber W forming the valve-seat is in the construction shown in Figs. l and 2 provided with three openings or ports NV' W2 W2 in the wall thereof. The port W' communicates with the fluid-chest WVO. The other two ports W2 W3 communicate by passages one to one end and the other to the other end of the workin g cylinderA'. The valve V is provided with eXhaust-ports V' V2, that communieate with a common outlet V4, and it is also provided with an admission port or passage V3. The ports are so arranged that in one position of the valve, as shown in the drawings, Fig. l, a communication is opened between the port W3, leading` to one end of the cylinder A', and the fluid-chest IVO through the passage V3 in the valve, while the port W2,
leadin-g to the other end of the cylinder, is openv to the exhaust through the port V' in the valve. In another position of the valve the fluid-chest W'J is in communication with that end of the cylinder which was before open to exhaust and the opposite end of the cylinder is open to exhaust.
It is obvious that the exhaust from the cylinders Z Z' takes place simultaneously with that from the two ends of the working cylinder A'.
In a modification shown in Fig. l2 the valve chamber or seat has six openings or ports in the side thereof. Two of the said ports-viz., W' and Wij-communicate directly with the iiuid-chest W0, the two ports XV? and W3 communicate with the opposite ends of the working cylinder A', as before, and the two remaining ports V4 and W5 are exhaust-ports.
The valve is provided with ports V', V2, and V3, of which V' and V2 are in communication with one another. -The passages are so arranged that in one position of the valve, as shown, a communication is opened between the port W3, leading to one end of the cylinder A', and the fluid-supply port V3, while the port W2, leading to the other end of the cylinder, is open to the exhaust-port W5 through the ports V' V2 in the valve. In another position of the valve the port TV3, which was formerly opened to the supply-port V3, is then opened to the second exhaust-port IV, and the port W2, which was in communication with the exhaust-port lV, is open to the supplyport V3. Hence when the motive fluid is being admitted to one end of the cylinder the other end of the cylinder is in communication with the exhaust. On the valve being turned to its second position the working fluid is admitted to the opposite end of the cylinder and the first-named end is opened to the exhaust.
For working the valve I provide small cylinders Z Z', Fig. 3, having pistons c c' working therein and also having ports or passages a ct', which communicate with the working cylinder A'. The valve is provided with wings or arms cl d', that project above the pistons c c' and that are operated by said pistons when the latter move up and down. When the piston C in the Working cylinder'A' approaches the end of its forward stroke, it uncovers the passage ct and allows the working iiuid to enter the cylinder Z and act on the small piston c therein. The said piston c is thereby raised and caused to act on the arm d of the valve and thus turn the valve. W'hen the piston O in its backward stroke uncovers the other passage ct', (the passage ct being then closed,) the piston c' of the cylinder Z' is raised and caused in the same manner to turn the valve Vin the opposite direction. The ends of the passages d a.' indicated by dotted lines in Fig. l are really in front of the plane of section.
I sometimes provide only one arm or wing d on the valve, as shown in Fig. 5, and I then place the two cylinders Z Z' on opposite sides of the said arm, so that the pistons c c' of the cylinders Z Z' may act alternately on the said arm, but in opposite directions.
I may employ more than two cylinders such Y as Z Z'. y
rPhe arinsor projections are secured or made solid with the valve in such a manner that the valve will be balanced and will only alter its position when positively operated. Such a vbalanced valve will work equally well in any position and angle at which a rock-drill may be required to be worked. j
My improved valve is not subject to much or uneven wear, since it has a rotary reciprocating motion in place of a sliding reciprocating motion. Moreover, the valve may be easily constructed of such a design as will enable a drill to be made short and light, which are attributes of especial advantage in rockdrills.
l. In a rock-drill, the combination with the casing, and the drill-spindle, of a twist-bar capable of a rotary and a limited axial movement in the casing, a toothed gear fixed on the rear end of said twist-bar, and a non-rotatable, stationary gear D supported in the casing and adapted to lock the twist-bar when the latter is pushed backward, and to become disengaged therefrom when said twist-bar is pushed forward or outward, substantially as described. l
2. In a rock-drill, a tool-holder consisting of a head E furnished with a taper-keyway E' smallest at the forward end, and a wedge or key .I which projects from the head at the forward end and hasv a prolongation J at the rear end projecting through an opening in the rear end of the head, substantially as described.
3. 1 In a rock-drill, the combination with the casing and cradle, of a clamp havinga key- `way M in the opening P for the drill-bar, the key N, the fixed jaw L, the movable jaw L' having in its back the recess L5, and the bolt O working in the lugs O' to support and adjust said movable jaw between which and the fixed jaw is received the foot of the cradle, substantially as described. Y
4. In a rock-drill, the means for taking up slack due to the wear of the feed-screws, guides and bushes, and for preventing jar at the handle of the operating mechanism, said means consisting of split conical feed-nuts Q for the feed-screw and bushes for the guides, received in conical lugs formed on the drillcasing and having their large ends facing each other, and a spiral spring interposed between said large ends substantially as described.
5. In asrock-drill, a balanced circular valve V adapted to oscillate in a valve-chamber without gland or bushing about an axis at right angles to the axis of the working cylin-l uder, wings or arms integral with the valve, pistons c, c' adapted to control the said arms IOO IIO
In testimony whereof I have hereunto set my hand this 5th day of September, 1895.
JAMES MOCULLOCIT. Vtn esses:
SIMON ROBERTS, VILLIAM G. COOPER.