USRE5285E - Improvement in machines for drilling rock - Google Patents

Description

S. W. ROBINSON & De V. WOOD.-

Machines for Drilling Rock. N0. 5,285. Reissued Feb.18,l873.

UNITED STATES PATENT OFFICE.

STILLMAN ROBIN SOX, OF CHAMPAIGN, ILLINOIS, AND DE VOLSOX WOOD, OF ANN ARBOR, MICHIGAN.

IMPROVEMENT IN MACHINES FOR DRILLING ROCK.

Specification forming part of Letters Patent No. 71,329, dated November 26, 1867 reissue No. 5,255, dated February 18, 1873.

To all whom it may concern:

Be it known that we, STILLMAN W. ROBIN- SON, formerly of the city of Ann Arbor, county of Washtenaw, and State of Michigan, but now of Champaign, Champaign county, in the State of Illinois, and DE VOLSON WnoD, of the former place, haveV invented certain 1mpro-vements in Rock-Drills, of which the following is a specication, reference being had to the annexed drawing, in which- Figure 1 is a perspective view of the machine, and Fig.'2 is a longitudinal section of the same through the center of the cylinder and -piston-rod. Fig. 3 is a longitudinal section of the tool-holder shown in Fig. 1.

The nature of our improvement consists in the employment of a reciprocating cylinder for driving the drill; also, of an improved toolholder; also, of an improved automatic feed; and, also, of an-improved device for rotating the tool.

AAis a steam-cylinder, which has no steamports or steam-passages, and which is made steam-tight about the head and piston-rodby any of the well-known ways. The forward end of the cylinder is somewhat prolonged so as to form the tool-holder, as hereafter described. The cylinder is also free to reciprocate over the piston and piston-rod. The tool may be rotated by rotating the cylinder, as will be hereafter described and the cylinder also operates the valve and feed device. Such a cylinder, which, for convenience, is here called a drillbar, is used for driving and operating the tool. The piston-rod B lis firmly secured at its rear end to the projection D of the carriage Z in any convenient manner, and serves as a support and guide to the cylinder A. There may also vbe an additional support and guide, E. The piston-rod also contains the steam-passages b and c, one of which enters the cylinder at R a short distance back of the piston, and the other enters it in front of the piston at S. The other ends of the steam-passages enter the steam-chest, and the movement of the steam to and from the cylinder" is regulated by the vialve F. The movement of the valve F is regulated by the reciprocation of the drill-bar A.

in any convenient manner.

vBy the arrangement above described the cylinder, piston-rod, and piston may all be easily made of wrought-steel or wrought-iron, thus rendering them very durable and not likely to break. This arrangement also secures a more compact drill than has been before made, it beingshorter forthe same length of stroke and the same amount of bearing between the pistonrodand cylinder than any other drill, which is verydesirable in portable drills. By this arrangement, also, the Whole shock produced by the blow is received by the drill-bar, and the steam-packing, which is usually placed on the piston, is not subjected to shocks.

To prevent the forward head of the cylinder from strikin-g the piston at the end of the back stroke of the cylinder the plug T enters the port S, thus automatically closing it and retaining a portion of the motor, which acts as an elastic cushion or spring for bringing the cylinder to rest. In a similar Way the port R may be automatically closed by the rear head A of the cylinder passing over it near the end of the forward stroke, and a cushion thus formed.

The toolholder is made as follows: A hollow cone, P, which is shown in section in Fig. 2, is made in the forward end lH of the drillbar A A. Into this cone are fitted several conical wedges, G G, Fig. 1, the outer surfaces of which have the same slope as the inner snrface e e of the hollow cone P; and between the inner surfaces of the wedges a cylindrical passage is formed to receive the head of the tool N. Any number of wedges may be used; but we have foundthree to be the most convenient number. On account of the slopingsurfaces e e the wedges, as they are drawn outward, will be forced toward the axis ofthe cone, so as to partly close the cylindrical space between them before referred to. If the tool N is inserted and the wedges are thus drawnont they will press upon the tooland hold 'it by friction.

By this arrangement the tool may be antomatically seized as follows: When the tool N, Fig. 1, strikes the rock it is forced back against the bottom of the cone, which is shown at m, Fig. 2, thereby suddenly stopping the advance of the drill-bar A A; but if the wedges G G are loose they will pass on and wedge in bescribed.

tween the hea-d of the tool and the surface of the conc, as before stated, and thus hold the tool. This arrangement ofthe cone and wedges also permits dilferent-sized drill-heads to be used.

` Rotation of the drill-bar is secured as follows: A long click, L L, is pivoted at its ends y so as so rotate about its back edge, and its workin g-edge is somewhat spiral and inclined to the axis of the drill-bar, and is forced into hearing by a spring, a. During the back stroke of the drill-bar the click L L engages the teeth of the ratchet M on the rear head of the cylinder and causes a partial rotation of the drillbar; but during the advance stroke, there being nothing to cause rotation, the click falls intoy the next tooth. The'back of the click` may ybe nearly parallel to the working-edge.

The carriage Z Z, to a projection of which l the piston-rod is attached, as beforestated, may

move along the ways Y Y when there isnothing to prevent. When it is desirable to hold the machine in position the gripe Q so operates as-to prevent a back movement; and O,

`in a similar manner, prevents a forward movement, as hereafter explained. The gripe Q has a notch near one end so as to bind upon the. `rib Y, while the other end is secured to the carringe Z in any convenient manner. The end which bears on the rib is pressed forward by a spring, d. When this gripe is in bearing it 'prevents the machine from moving back in the ways. O is a similar gripe to prevent a forward movement; but, instead of a spring like d, it is held in any desired position by friction, which may he induced by a screw, f, or in any other convenient manner.

The cylinder-head C projects beyond the circumference ofthe cylinder, and has a ratchet, M(before referred to,) on its edge. The lower side 19 ofthe projection serves as a tappet. When the cutting has advanced so far that a forward feed is necessary the tappet p, at f the end of the forward stroke, strikes the lever- N, wl1ich,by pressing against the gripe 0, drives theouter end of said gripeforward on the rib V, where it is retained by friction, as before stated.. v The carriage Z Z is now free to move forward the same amount that 'the gripe O has been advanced. Now -a's themetor enters the rear end of the cylinder to drive backward, the reaction 'of the motor on the piston-which reaction is the samein amount as the pressure on-the rear cylinder-headforces the piston and all attached to it forward as far as is permitted by the new lposition of the gripe 0. The gripe Q, being thus carried forward to the advanced position', holds the cannot return toits old position. When the cutting advances rapidly the gripe O is advanced more frequently, or is advanced more at each blow, orboth at the same time, thus admitting of a rapid feed. In this way the feed is .perfectlyautomat-ic. By freeing the gripe Q while O is in bearing a back feed-may besecured in the same way.

A momentum feed may be secured a/s followsz. 1f, from any cause, the drill does not i strike the rock-as, for instance, if, at `the beginning of work, the drill is too faLfrom the rock-the head of the cylinder, near the end of the forward stroke, automatically closes the port R, and retains a portion of, the. motor,- w-hich now acts as a spring, as before explained; andv at the same time the tappet p drives the lever N and gripe O forward, as before explained; while the momentum of the drillbar and all attached, acting upon the piston at or near the end of theforward stroke,

forces the piston and carriage and all attached i to it forward on the Ways Y Y, where they are retained by the gripe Q, as before described, thus securing a rapid feed until the tool strikes the rock, after which the reaction feed .comes into action.

In these feeds the gripes O and Q do not force the feed on the ways. Their ofce is to regulate the feed.

We do not confine ourselves to these particular devices, as we have used in practice several others for regulating the feed. The devices must be so constructed Aand arranged that the forward feed shall be regulated by the advance of the drill-bar 3 and immediately after the regulating'. device has been operat-l ed the devices must permit the carriage Z Z to move forward by the reaction of the motor in thecylinder.

What we claim'as new, and desire to secure by Letters Patent, is- 1. -In a rock-drill, the construction and arrangement of a cylinder foi` driving a drill, y one end of said cylinder serving as a tool-hol der, and having lsuitable attachments for rotatin g the tool, or feedin g it forward, or both combined, as hereinddescribed.

2.- The click L L, rotating on an axis parallel to or somewhat inclined to the axis of the drill-bar, in combination with the ratchet M, as and for the purposes described.

3. In machines for working on stone in which the tool is reciprocated by an elastic motor in a cylinder, the combination of the cylinder, ways, and gripes 0 and Q, or other suitable devicesfor` holding the` machine to the ways, constructed and arranged essentialyly as set forth, that when the device 0 is freed from its hold at or near the end of the forward stroke by means of a projection on the drill-bar, the machine maybe fed 'forward carriage Z Z and all attached sor that it.

5,2m d a.

4on the ways bv the reaction of the motor in 6. The tool-'holder,as described, consisting the cylinder during the back stroke of the of the hollow coneP and wedges GG, constructdrill-bar, and held i'n its advanced position by ed and arranged as describe means of the device Q, substantially as de- STILLMAN W. ROBINSON. scribed, and vfor the purposes set forth.l DE 'VOLSON WOOD. l 4. The combination of the gripe O, lever N, Witnesses for STILLMAN W. ROBINSON:

ways Y, and tappet p, as and for the purposes R. E. MOORE, described. J. BELLANGEE;

5. The combination 'of the carriage Z, gripe Witnesses for DE VOLSON WOOD: Q, spring d, and ways Y, as and for the pur ZINA P. KING,

.poses described.

B. C. FRENCH.

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