US822367A - Pneumatic drill. - Google Patents

Description

No. 822,367. PATENTED JUNE 5, 1906. A. P.-HANSUOM.

PNEUMATIG DRILL.

APPLICATION FILED AUG. Z7, 1903.

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ADELBEHT P. HANSCOM, OF MALDEN, MASSACHUSETTS.

PNEUMATIC DRILL.

Speccation of Letters Patent.

Patented June 5, 1906.

Application filed August 27,1903 Serial N0.

To @ZZ whom t vta/y concern:

Be it known that l, ADELBERT P. HANS- ooM, a citizen of the United States, and residing at Malden, in the county of Middlesex and State of Massachusetts, have invented an Improvement in Pneumatic Drills, of which the following description, in connection with the accompanying drawings, is a specification, like characters on the drawings representing like parts.

This invention relates to pneumatic drills, and more particularly to that type of such apparatus wherein a plurality of pistons and cylinders actuate, by or through suitable speed-changing mechanism, a centrally-arranged arbor by which the drill is carried.

One of the objects of my present invention is the arrangement of the various working parts of the apparatus in a compact, strong, and durable manner, the engine or motor being so disposed with relation to the drill-carrying arb or that maximum power may be imparted thereto with an eflicient balancing of parts.

Another object of my invention is the improvement and simplification of the valve mechanism which controls the ingress of the motive fluid to and its exhaust from the cylinders of the engine or motor.

Another'object of my invention is the production of a simple and convenient reversing device to change the direction of rotation of the arbor.

The various novel features of my invention will be fully described in the subjoined specification and particularly pointed out in the following claims.

Figure l is a vertical sectional view of a pneumatic drill embodying one form of my invention, taken on the line l 1,Fig. 2, a por-v tion of the transmitting-gearing and the arbor being shown in elevation. Fig. 2 is a vertical section in a plane at right angles thereto on the irregular line 2 2, Fig. l, looking toward the left with 'the arbor in elevation, the engine-pistons being shown at full stroke, as in Fig. l. Fig. 3 is an enlarged detail in plan and partly broken out, showing the reversing means for the engine. Fig. 4 is sectional detail thereof on the line 4 4, Fig. 8, looking toward the left. Fig. 5 is an enlarged longitudinal section on line 5 5, Figs. 6 and 7, of the means for controlling the passage of motive fluid to and from the cylinders andi which also serves as the common fulcrum or? trunnion on which the cylinders oscillate, the

i the cylinders, the latter being shown at halfstroke. Fig. 8 is a detail in elevation and part section of the center bearing for the crank-shafts of the motor.

In the present embodiment of my invention the motor and transmitting mechanism are inclosed within a case comprising a top portion A, having parallel end walls a a, Fig. l, and oppositely-sloping side walls a a, joined at their upper ends by an arched portion ax and connected at their lower ends by suitable means, as screw-bolts au, with the casing-bottom A20, the bolts passing through circular llanges 75 and 76 on the casing top and bottom portions, respectively.

The top portion A is strengthened by a central web a2, parallel to the end walls and extended from one side wall part way across the portion A, the web being provided with a suitable seat a3 for a bearing for the inner adjacent and alined ends of two crank-shafts c c, (see Fig. 1,) the outer ends of .said shafts being supported in bearings a7 a, shown as thimbles held jointly by the top and bottom members of the case and preferably provided with antifriction-rolls 7, Fig. l.

Each thimble has a ilanged head 8 and a lateral annular flange 9 at its inner end, the flanges entering correspondingly-shaped seats in the casing and cooperating with the flanged heads 8 to retain said bearings from longitudinal movement.

Referring to Figs. 1 and 8, the center bearing is shown as comprising two bushings a4, set into the seat a3 from opposite ends and having flanged heads a5 to enter the counterbored ends of the seat, the inner ends of the bushings abutting, and separate disks a iit into said inner ends to form a backing for the antifriction-rolls a7, surrounding the ends of the crank-shafts. The two crank-shafts are thus alined and located on opposite sides of the central web a2, each one having a bevelpinion, as GX cX, secured thereon adjacent the inner ends ofthe thimbles or bushings a7 a, respectively, while collars 70 and 71 on the shafts abut against the outer ends of the bushings a4.

The bottom portion A20 of the casing is circular in cross-section and tapers toward its IOO IIO

lower end, terminating in a cylindrical boss @15, provided with an internal annular shoulder a,16 and having a plurality of external radially-extended ears a, shown in Figs. l and 2 as connected with the portion A20 by strengthening-webs als.

A bushing bx, having an external annular shoulder b to seat on the shoulder als, is inserted in the boss @15 into the position shown best in Fig. l, the upper end of the bushing only partly filling the boss above the shoulder 01,16, andan internal annular shoulder b is formed in the bushing.

yThe tool-carrying arbor B, internally recessed at b2 to receive the shank of the drill or other tool, enters the bushing b with a running iit and has an annular enlargement b3 to seat on the shoulder b of said bushing.

Above the enlargement b3 the arbor is reduced in diameter at b4 to enter the hub c2 of a large bevel-gear C2 in mesh with the bevelpinions 0X cX, a key b5, Fig. l, being employed to rigidly connect said gear with the arbor to rotate in unison.

The extremity of the arbor above the part b4 is still further reduced in diameter, as at b, and it enters a socket L19 in the bottom of the seat 0,3, said socket being counterbored at a2". (Shown most clearly in Fig. 8.)

The counterbore L20 serves to position a hardened-steel disk a, forming one half of a raceway for a series of balls 2l, the disk being pinned to the bottom of the seat a3 at 22, (see Fig'. 1,) while the other half of the raceway is shown as a' disk @22, also of hardened steel, pinned at 23 to the top of the hub c2, the part b6 of the arbor passing loosely through both disks, the pin 23 being dotted in Fig. 2.

As will be manifest, the disks and balls form an antifriction end-thrust bearing for the arbor, the thrust being transmitted through the seat a3 to and being taken up by the web a2.

Referring to Figs. l and 2, it will be seen that the externall -cylindrical base of the hub c2 iits into the boss @15 above the top of the bushing b and rests u on the latter the sides of the boss affording a lateral bearing to assist in positioning the hub.

A strengthening-ring L25 is secured by bolts a2 to the ears a, said ring surrounding the lboss @15 near its lower end and serving to stiHen and strengtheny it, this ring being removed when the angle attachment is applied, as will be described.

In order to prevent any binding of the gear C2 by or through end thrust of the arbor, the bottom of the gear-hub is slightly recessed at 24, Fig. l, above the enlargement b3 of the arbor, the thrust being transmitted from the upper end of part b4 of the arbor to the thrustbearing.

Inasmuch as the bevel-pinions engage the gear C2 at diametrically opposite points, it is necessary to provide two separate crankshafts, rotating oppositely, as herein shown, the direction of rotation of the gear C2 being indicated by the arrow 26, Fig. 2.

The pinions and bevel-gear form transmitting means intermediate the motor or engine, to be described, and the tool-carrying arbor B.

The end walls a and a are provided with two opposite circular apertures bored to provide true bearing-surfaces for the valve structure, which latter also constitutes a trunnion or support on which the cylinders of the motor are mounted to oscillate, the apertures being surrounded by internally-threaded nipples aa" @31, respectively, Fig. l.

Threaded plugs da() dsl are screwed into said nipples after the trunnion is in place, preventing longitudinal movement thereof, the plug ab being solid, while plug 0331 has a passage 32 through it to admit motive iuid, such as compressed air, to the apparatus, the outer end ofthe passage registering with the upper end of a conduit @32 in the wall a.

An inlet-pipe @33, Fig. l, communicating with the lower end of the conduit, conducts motive fluid thereto from any suitable source of supply.

The construction of the trunnion is best shown in Figs. l and 5.

Two cylindrical tubes g and b, having a common bore, are driven tightly into outer tubes gX hX, respectively, the outer tubes having their inner ends butted` together, while one of the inner tubes, as g, is counterbored at its inner end, as at g/, to snugly receive the reduced end b of the tube h, one of said tubes being capable of rotative movement, however, relative to the other.

Before assembling the tubes g and 71, are externally cut away for a part of their length and extending nearly around their outer circumferences, leaving clearance-spaces g2 b2 between the inner and outer tubes, the latter being provided with holes g3 b3, respectively, communicating with the clearances, which constitute exhaust-chambers. As shown in Figs. l and 5, the end of the tube g adjacent the plug d3 is closed, as at g3".

The mode of construction described is very simple and convenient, a strong and eflicient trunnion and valve being provided at small cost.

An elongated inlet-port is'made in each section or half of the trunnion, the ports being shown at g4 b4 in Figs. 6 and 7, respectively, and establishing communication between the bore I of the trunnion, which may be termed the inlet-chamber, and the exterior of said trunnion, each port extending from the chamber l through the outer tubes gX and bx, respectively.

On opposite sides of and adjacent the said ports the tubes g and b,X are each provided with two ports, as g5 96 and b5 h6, (shown in Figs. 6 and 7,) communicating with the exhaust-chambers g2 b2, respectively.

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cease? Upon the trunnion are vibratorily mounted and suspended the twin cylinders C C, having equal length and diameter and provided with suitable pistons P P', respectively, Fig. 1, the piston-rods p p being shown as rigid with or forming part of the pistons and extending out through the lower open ends of the cylinders. The upper ends of the latter are closed with the exception of ports 50 51, (see Figs. 6 and 7,) and said ends are provided with tubular extensions C10 C11 which surround the trunnion with an easy but steam-tight fit to rock thereupon. lt will be understood that the several inlet and exhaust ports formed in the trunnion are elongated to conform to the length of the ports 50 or 51 in the cylinder ends, the cylinders by their oscillation moving their ports into and out of register with the ports of the valve structure or trunnion. Each end of the latter is thus provided with three portsa central one for the admission of motive fluid to a cylinder and one on each side for the exhaust.

The material of the outer tubes g or hX, which separates the central inlet-ports from the contiguous exhaust-ports, is of such width in each instance as will just cover the port in the cylinder.

inasmuch as the crank-shafts rotate in opposite directions, the cylinders will vibrate or oscillate in the same direction rather than oppositely, as would be the case if the crankshafts were connected and rotated in the same direction.

Vhen the two pistons are at full stroke, as in Fig. 1, the cylinders will be up and down and the two cranks one hundred and eighty degrees apart, while at half-stroke the cranks will be just passing each other and the cylinders will be inclined at one or the other side of the vertical axis of the apparatus.

In Fig. 7 the piston of the cylinder C is supposed to be at half-stroke, the cylinder taking motive iiuid through ports h4 and 51, and when the outward stroke is completed and the inward stroke begins the port 51 will begin to register with the exhaust-port h5.

As to cylinder C, from Fig. 6 it will be manifest that its piston is at mid-stroke, the cylinder exhausting through ports 50 and g5, the piston being on its inward stroke.

The exhaust is discharged through the ports or outlets g3 h3 into the casing and escapes thence to the outer air by means of an outlet-nipple EX, Fig. 2.

The ports g6 and h6 are utilized when the valve structure is shifted to reverse the motor, so that the arbor-gear C2 and arbor B will be rotated oppositely to the arrow 26, Fig. 2.

Vhen the motor is to be reversed, by means to be described the right-hand half of the valve structure, Fig. 1, will be partly turned in direction of arrow 100, Fig. 7, while turned oppositely in direction of arrow 101, Fig. 6, it being remembered that Figs. 6 and 7 are viewed from opposite ends of the valve structure.

The top portion A of the casing is provided with a housing A5, Figs. 2, 3, and 4, extended laterally from the wall du and surmounted by an internally-threaded boss as@ in alinement with'the arbor B for a purpose to be described, the housing opening into the interior of the casing, as at 85, Fig. f1.

Collars gS hs are secured to the tubes g and h at opposite sides of the sleeve-like center bearing a for the valve structure, (see Fig. 1,)formed in the web a2, each collar having a threaded boss 63, Fig. 1, to receive the threaded end 64 of a reversing-arm, said arms g9 h" being clearly shown in Figs. 2 and 3 and slightly tapered, as at 65, beyond the thread to pass through a hole in the outer tube and enter a socket g10 or hw in the inner tube. By thus engaging both tubes of a pair they are turned in unison without any twisting strain, though it will be understood that the two tubes are rigidly secured together by forcing the inner one into the outer one.

The reversing-arms extend from the valve structure at right angles thereto and pass through the housing A5 into a chambered cover-plate A6, detachably held in place by suitable screws 200, Fig. 8, the cover-plate having a central bearing-boss 201 and an external flange 202 for a lpurpose to be described.

The central solid portion of the housing is provided with a socket 203 Fig. 3, for the inner end of a stud rx, rotatably mounted in the boss 201 and projecting therethrough into the space inclosed by theA flange 202, a handle 1 of any suitable construction being secured to the stud.

Between the boss 201 and the adjacent end ICO ` the stud, said block having elongated eyes r2 on opposite sides to receive loosely the free ends of the reversing-arms g 7L, so that by turning the stud by means of the handle r/ the said arms willbe moved oppositely. Such movement of the arms turns the two halves of the valve structure in opposite directions to reverse the operation of the motor-that is, if the valve structure is in the position shown in Figs. 6 and 7 and the reversingstud rx is turned the valve halves'will be turned to bring the exhaust-ports g6 and h into op erative position and render the ports g5 h5 inoperative. Thus by a turn of the hand the operator can reverse the motor, the flange 202 acting as a shield for the handle r2 and preventing the stud TX from being turned accidentally.

As shown in Fig. 3, the inner face of the yoke-block 1" has two pits or depressions therein, as 1", and the solid center of the houssimultaneously the left-hand half will be l ing A5 is recessed at each side of the center at ITO T5, each to receive a locking bolt or plunger r, pressed outward by a spring r3 and having a pointed or conical top rs.

The depressions r4 are so located on the block that when the stud rx is in position for forward or backward operation one of the bolts r will enter a depression and hold the stud in the proper position. The lockingbolts thus indicate to the operator when the valves are in the correct position, as at such time one or the other of said bolts will snap into its depression r4.

The internally-threaded boss aso, Fig. 1, is

socketed to receive the inner end of a threaded stud (182, having an annular flange 0,83 fast upon it to enter the boss, a heavy retainingbushing ai being screwed into said boss and bearing upon the iiange (1,83, so that the stud (182 is rigidly held in position and in alinement with the axis of the arbor B. An internally-threaded back center L85 is screwed upon the stud and provided with handles a8, by which it may be more readily revolved, the operation of the back center being familiar to those skilled in the art and requiring no further description.

Opposite the inlet 1,33 the part A of the casing is provided with a hub or boss a, into which is screwed a handle-bar am, (see Fig. 1,) by which the positioning of the apparatus is facilitated.

The free ends of the piston-rods p p are enlarged, as at 23202921, respectively, Fig. l, to support bearing-boxes of any suitable character for the cranks of the two crank-shafts, boxes provided with rolls or similar antifriction means being preferable.

From the foregoing description, in connection with the drawings, the operation of the apparatus will be readily understood, the transmitting means intermediate the crankshafts and arbor acting also as a speed-reducer, so that the engine or motor may be run at high speed.

The construction is simple, compact, and efficient, the power being applied to the large gear C2 at two diametrically opposite points, and the support for the arbor both as to end thrust and lateral bearings is strong and rigid.

Having described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. In apparatus of the class described, a casing, an arbor rotatably mounted in and extended through one end thereof, a pair of oscillating cylinders each having a piston, a combined trunnion and valve structure supported within the casing and on which the cylinders are mounted side by side, at their ends, two separate crank-shafts operatively connected with the pistons and mounted in alinement, a pinion on each crank-shaft, and a gear operatively connected with the arbor and with whichsaid pinions mesh at diamet= rically opposite points.

2. In apparatus of the class described, a casing, an arbor rotatably mounted in one end thereof, a pair of oscillating cylinders each having a piston, a combined trunnion and valve structure supported within the casing and on which the cylinders are mounted side by side, two crank-shafts operatively connected with the pistons and mounted in alinement, a pinion on each crank-shaft, a gear operatively connected with the arbor and with which the pinions mesh at diametrically opposite points, a central web in the casing, between the cylinders, a bearing on said web for the center of the trunnion, and a second bearing sustained by the web for the inner ends of the crank-shafts.

3. .ln apparatus of the class described, a casing comprising separable top and bottom portions, the former having an integral central web and the latter having a boss at its end, a combined trunnion and valve structure supported by the casing top and web, transversely to the latter, oscillating cylinders mounted at their ends on said trunnion at opposite sides of the web and each provided with a piston, a center bearing sustained by the web, a plurality of alined and independent crank-shafts operatively connected with the several pistons and supported at their adjacent ends in said center bearing, bearings for the outer ends of the shafts, mounted j ointlyv in the top and bottom of the casing, an arbor rotatably mounted in the boss of the casing-bottom, and transmitting means intermediate the crank-shafts and arbor, to rotate the latter.

4. In apparatus of the class described, a casing comprising separable top and bottom portions, the former having an integral flat central web and the latter having a boss at its end, crank-shaft bearings mounted jointly in said parts of the casing, a center bearing on the web, a plurality of oscillating cylinders mounted within the casing-top and each provided with a piston, a plurality of independent crank-shafts operatively connected with the pistons and mounted at their inner ends in the center bearing, the outer ends of the said shafts entering the bearings in the casing, an arbor rotatably mounted in the boss of the casing-bottom at right angles to said crank-shafts, transmitting connections between the latter and the arbor, to rotate the latter, and means to govern admission of motive fluid to and exhaust thereof from the cylinders.

5. In apparatus of the class described, a two-part casing, a flat central web in one of said parts, a pair of oscillating cylinders mounted in said part on opposite sides of the web and each provided with a piston, independent crank-shafts operatively connected IOO IIO

with the istons and arranged in alinement, bearings 'or their outer ends, on the casing, a common bearing for their inner ends, carried by and transverse to the web, an arbor rotatably mounted in and extended through the other part of the casing at right angles to the crank-shafts, an end-thrust bearing for the arbor, sustained by the web, immediately adjacent the crank-shaft bearing, and gearing intermediate the crank-shafts and arbor to rotate the latter.

6. In apparatus of thel class described, a two-part casing, a central web in one of said parts, a pair of oscillating cylinders mounted in said part on opposite sides of the web and each provided with 'a piston, independent crank-shafts operatively connected with the pistons and arranged in alinement, bearings for their outer ends, on the casing, an arbor rotatably mounted in and extended through one part of the casing, a gear connected with the arbor and rotating therewith, and a pinion on each crank-shaft, 1n mesh with the gear, said pinions engaging the latter at diametrically opposite points, the crank-shafts rotating in opposite directions.

7. In apparatus of the class described, a two-part casing, a central web in one of said parts, a pair of oscillating cylinders mounted in said part on opposite sides of the web and each provided with a piston, independent crank-shafts operatively connected with the pistons and arranged in alinement, bearings for their outer ends, on the casing, a seat on the web roller-bearings mounted thereon for the inner ends of the crank-shafts, an arbor rotatably mounted in and extended through the bottom part of the casing at right angles to said crank-shafts, an attached gear, a ballbearing interposed between the arbor and the seat, to take up end thrust of the arbor, and a pinion on each crank-shaft near its outer end, in mesh with and to rotate the arbor-gear at reduced speed.

8. In apparatus of the class described, a casing, an arbor rotatably mounted` in the bottom thereof, a gear keyed to said arbor within the casing, an engine mounted in the top of the latter and comprising two oscillating cylinders arranged side by side, each provided with a piston, a tubular extension at one end of each cylinder, having a port into the cylinder, means to rotate said gear by or through reciprocating movement of the pistons, and a combined trunnion and valve structure for the cylinders, comprising two alined and relatively rotative tubes constituting an inlet-chamber and provided with outlet-ports, an outer tube on and iixed to each of said tubes with an annular clearance therebetween to constitute two separate exhaust-chambers, and an inlet and an outlet port for each, the outlet-ports opening into the casing, the inlet-port of each exhaustchamber being adapted to coperate with the cylinder-port alternately with the outletport of the inlet-chamber, the tubular extensions of the cylinders surrounding the outer tube of each pair of tubes.

9. In apparatus of the class described, a casing, a trunnion mounted therein, and comprising two pairs of tubes in alinement and sleeved together, the two inner tubes communicating and constituting an inletchamber, the outer tubes being secured to their inner tubes with annular clearances between them to constitute two exhaust-chambers, each outer tube having an inlet-port communicating with the inlet-chamber, and two exhaust-ports on opposite sides of said inlet-port, each pair of exhaust-ports communicating with an exhaust-chamber, a cylinder mounted to oscillate on the outer one of each pair of tubes and having a single port, an arbor rotatably mounted in the casing, pistons for the cylinders, crank-shafts with which they are operatively connected, gearing between the crank-shafts and arbor to rotate the latter, and means to effect opposite angular movement of the two pairs of tubes constituting the trunnion, to eliect reversal of the engine, and consequently reverse the rotation of the arbor.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

ADELBERT P. HANSCOM.

Witnesses:

JOHN C. EDwARDs, MARGARET A. DUNN. jfl

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