US675490A - Rock-drill. - Google Patents

Description

Patented lune 4, 190|.

ROCK DRILL.

(Application filed Oct. 8, 1900.)

C. T. LITCHFIELD.

(No Model.)

, UNITED STATES PATENT OFFICE.

CHARLES TIFFANY Ll'lCllFIELD, OF SPOKANE, lVASl-IINGTON.

ROCK-DRILL.

SPECIFICATON forming part of Letters Patent No. 675,490, dated June 4, 1901.

.aspiration and october s, 1900. senti No. 32,403. un man.)

Be it known that I, CHARLES TIFFANY LrroHrTEL'n, a citizen of the United States, residing at Spokane, in the county of Spokane and State of Washington, have invented a certai new and useful Improvement in Rock- Drills, of which the following is a full, clear, and exact description.

This invention relates to the valve mechanism of rock-drills and other' pneumatic or Huid-pressure tools or apparatus.

The object of the invention is to provide mechanism whereby not only the forward movement, but the return movement to com plete the stroke, shall be elfected by pressure automatically controlled.

In carrying out my invention I employ a reciprocating piston connected with a plunger, the two being separated by a diaphragm, which permanently divides the pressurechamber in which the piston moves from that in which the plunger moves, and within the medium connecting the piston with the plnn` ger I employ a valve by which the ilow of the iluid or pressure agent is controlled and also by which the pressure is transferred from one side to the other ol the piston to el'l'ect the forward and backward movements to complete the stroke.

I have illustrated my invention as applied to one forni of rock-drill in which compressed air is used as the motive power; but I wish to be understood as not limiting my invention to rock-drills or other apparatus employingr compressed air as the motive power.

lVith this explanation I will proceed now to describe my invention as applied to a rockdrill. l. y

In the accompanying drawings, illustrating my invention, in the several ligurcs ol' which like parts are similarly designated, Figure l is a longitudinal sectional elevation showing the parts in the position they will occupy at the end of the return movement. Fig. 2 is a similar View of oni y so much lof the appara-tu.-. as is necessary to show the position of parts at the beginning ol` the -,forward movement. Fig. i is a View similar to Fig. 2, showing the parts at the end of the forward movement and in position to begin the return movement. Figs. 5, G, and 7 are cross-sections of the cylinder, taken, respectively, in the planes of lines fi, 5, 6, and 7 of Fig. l.

The cylinder a is provided with the internal liners and c, which liners are separated by a diaphragm d, preferably composed of simi lar metallic shells having recessed adjacent faces, in which is arranged any suitable packing, such as an elastic or compressible outer member and a metallic inner member, in one or more sections. The liner b is provided with the longitudinal channel e, which communicates at one end with a supply-passage j for the introduction of compressed air, steam, or other equivalent motive agent, and this passage extends to the diaphragm and communicates with the interior of the liner by means of a port y. The liner c has spiral grooves or other exhaust-passages hin its inner surface. The ends of the cylinder are provided with heads t' and j, which in the case of a rock-drill provide bearings la and l for the feed-screw m, which is arranged in a nut o of a supporting-bracket p, and the said feed-screw may be provided with any suitable means, suoli as a crank-handle, as shown, for rotating it. The chamber formed in the liner b between the head 'i and the diaphragm receives the piston q, and this piston has a longitudinal channel r extending through it and throughout the length ol its rod r', which is of less diameter than the piston-headpand this rod is connected with the plunger r2, which is arranged in the chamber in the liner c between the forward side oi' the diaphragm and the head j and made air or llnid tight therein by suitable packing, as at r3.

The piston-rod is provided with the through ports fr near one end and ith lateral ports T5 'r5 and through-ports 1 at or nearthe other end. W'ithin this hollow piston-rod is ar ranged a valve s, having a longitudinal bere sx extending from one end to near the other and at such closed end having a longitudinally-extended lateral port s', of a length sul'licient to uncover the ports T5, r, and lr?. The closed end of this valve projects into a chamber within the plnngerrzand is backed up by a-spring s2 in said chamber, which normally tends to throw the valve to the left or rearward. The chamber in the plungerl which contains the spring has a longitudinal chan` the back or return movement of the stroke,

as shown in Fig. 1, the motor fluid is admitted through inlet f, channel e, and port g into the space between the-forward side of the piston-head and the rear side of. the diaphragm and at the same time escapes through ports r and s' and bore 3X and the channel r to the rear of the piston-head on one side of the diaphragm. The pressure being now wholly to the left or rear of the diaphragm serves to move the valve s forward from the position Fig. 1 to the position Fig. 2, thus opening orts 14- and 77, thus admitting the pressure duid through the holler; valve and ports T5 and lr7 into the chamber? the other or forward side of the diaphragm, and since the superficial area of pressure surface, comprising the rear face of the piston, the rear end of the plunger, and the exposed surfaces of the valve, is greater than the supercial area of the forward end ot the piston it fol lows that the piston and its adjuncts will be moved forwardly until the ports r4 enter the diaphragm and are closed thereby, and thereby further admission of air to the rear of the piston is prevented, and then the air acting by its expansive force will complete the forward movement until the plunger uncovers the exhaust-passages h, as lshown in Fig. 2. When this occurs, all of the air in the cylinder escapes excepting that which is confined in the chamber in the liner h between the 'for ward-face of the pistonhead and the rear face of the diaphragm and air is admitted through channels s3 and s4 to the forward solid end of the valve, and that pressure, to- A gether with they recoil of the'spring s2, is sufticient to shift the valve to the left, asin Figs. 1 and 3, covering up the ports r4, which have been moved to the right of the diaphragm, and uncovering the through-ports T7 to exhaust the pressure in the rightehand chamber, so that the piston and plunger are relieved from back pressure on the return movement. As soon as the ports r* are closed by the reaction of the valve the air-pressure in the inlet-chamber between the forward face of the' piston-head and the rear face of the diaphragm, which pressure is constant, forces the piston to the left on the com pletion of the return movement. When the port is passed to the rear or left-hand side of the diaphragm on the backwardI movement, Fig. l, air is ad.- mitted through said port and the hollow valve and hollow piston to the rear of the piston,

vnext forward movement.

and the first result is the return or forward movement of the valve, so as to uncover the ports r4 and close the portsr'l-fromthe outer air, and thus the parts are in position for the rIhe diaphragm being made of sections with interposed packing material and being arranged between the liners and the liners being held in place by the heads of the outer cylinder, lam enabled to insure a sufficient compression of the packing against the piston-rod to obtain at all'-l times a fluid-tight joint.

I do not limit my invention to the employment of liners, since' the various channels may be made in the body of the cylinder; but for structural purposes and for purposes of re'- newal and repair l much prefer to use the liners.

l. A. fluid-motor, having a cylinder, a dia' phragm dividing the cylinder into'two cham; bers one of which is, the inlet and the other the outlet for said cylinder, a piston arranged in the inlet-chamber and a plunger arranged in the outlet-chamber, a hollow piston-rod passing fluid-tight through the diaphragm..

and rigidly connecting the piston and plun ger, and having a series of portsnear its opposite ends, and a valve arranged in said' hollow rod and provided with a longitudinal bore opening axially at one end and laterally near the other end and cooperating with the several ports in the hollow rod to control the admission and exhaustion of the motive fluid so as positively to eiect the movement of the piston in both directions, substantiallyas de scribed.

l. 2., A cylinder having a diaphragm dividing it into inlet and outlet chambers, a piston in the former and a plunger in the `latterga hollow ported rod passing Huid-tight through the diaphragm and connecting the piston and plunger, and an axially-bored and laterallyported slide-valve arranged within said hollow rod and edperating with its ports, substantially as described.

3. A cylinder having a diaphragm, channeled liners arranged withinihec'ylinder and on opposite sides of said diaphragm and form'- ing inlet and outlet chambers respectively, a piston in the inlet-chamber and a plunger in the outlet-chamber, a tubular ported connection for the piston' and the plunger, and a slide-valve arranged in the tubular connection and bored longitudinally at one end and ported laterally near the other end and co operating with the ports in the said connection, the plunger itself having pressure-inlets communicating with the valve,substantially as described. r

et. A cylinder having a diaphragm dividing it into inlet and outlet chambers, apiston in the former and a plunger in the latter, ahollow ported rod passing duid-tight through the diaphragm and plunger, andan axially-bored and laterallyported slide-valve arranged within said holloo IIO

connecting the pistou and low rod and coperating with its ports, the diaphrasgrnA itself periodically serving to cub oi the admission of the motive agent to the rear of the piston, substantially as'described. Y

5. Acylinder havinga. diaphragm dividing it; into inlet and outlet chambers, liners arranged in said chambers and having channels opening into the chambers and communicating respectively with a source of supply of power and the external air, on'opposite sides of the diaphragm, a piston in the inlet-chamber and a plunger in the outlet-chamber, and valve mechanism for controlling -the admission and exhaustion of the power agent, sub- I5' stantially as described.

6. A cylinder having a compressible diaphragm dividing it into two chambers, liners arranged in said chambers and abutting against the diaphragm, and cylinder-'heads 2o holding the'liners nslplace, substantially as described. y 4 In testimony whereof I have hereunto set. my hand this 1st day of October, A. D. 1900.-

- CHARLES TIFFANY LITOIIFIELD.

Witnesses:

B. LICHTY,

DAN L. WEAVER.

Itis hereby ceried that in lLetters Patent'No. 675,490, grantedunei, *1901, upon lcheapplieetaion of Charles Tiffany Litchfield, of Spokane, Washington, for an imprese? meub in Rock-Drills, an error appears in the printed'specication requiring correc-v tion, as follows: In line 34., page 1, after the .word r0ck-drl1s,a,l comma and the words or to rock-drills should be inserted; and that the said Letters Patent shold be read with this correction therein thai; the same mary conform to the record of the case in the Patent; Oice. I n i l Signed, countersigned, and sea? `d this 18th day of June, A. D., 1901.

[sEAL] F. L. CAMPBELL,

Assistant Secretary ofthe Litcror.

Countersigned 1F. I. ALLEN,

Chmmissoner of Paients.

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