US394484A - Pneumatic hammer - Google Patents

Description

'3 Sheets-Sheet'. 1.

(No Model.) K

Gr. GLOSSOP.

PNBUMATIG HAMMER.

No. 394,484. Patented Deo. 11, 1888.

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(NoModel.) I 3,Shets-Sheet 2.

G. GLOSSOP.

PNEUMATIG HAMMER.

y No. 394,484. Patented Deo. 11, 1888.,

(No Model.) l a sheets-sheen 3. G. GLSSOP.

PNEUMATIG HAMMER. No. 394,484. Patented Deo. 11, 1888.

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UNITED STATES PATENT OEEICE.

GILBERT GLOSSOP, OF SHEFFIELD, COUNTY O E YORK, ENGLAND, ASSIGNOR,

BY DIRECT AND MESNE ASSIGNMENTS, TO FREDERICK CLEMENT BROOKS- BANK AND JACOB B. PERKINS, BOTH OF CLEVELAND, OHIO.

PN EUMATIC HAMMER.

SPECIFICATION forming part of Letters Patent No. 394,484, dated December 11, 1888.

Application filed April 1'7, 1888. Serial No. 270,966. (No model.)

To all whom t may concern:

Be it known that I, GILBERT GLossoP, engineer, a resident of Sheffield, county of York, England, have invented certain new and useful Improvements in Pneumatic Hammers; and I do hereby declare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the art to which it appertains to make and use the 1o same.

Referring to the accompanying drawings, Figure l is a side elevation of a hammer embodying my improvements. Fig. 2 is a central longitudinal section of the pneumatic I5 cylinder and some of the associated parts on an enlarged scale. Fig. 3 is a cross-sectional view on line o; @c in Fig. l, showing the brake for the tup. Eig -i is an inside view of that portion of the hammer-frame which contains zo the brake-block, and showing said block in position. Fig. 5 is a perspective view of the upper part of the hammer, showing the position of the pneumatic cylinder and its connection with the main shaft.

The object of my invention is to provide and combine with a pneumatic hammer mechanism whereby the strokes of the hammer may be completely controlled without changing the speed of that part of the machine 3o which is connected with the driving-power, and also to improve pneumatic hammers in other respects, as hereinafter set forth.

To this end it consists in the construction and combination of parts herein described,

3 5 and definitely pointed out in the claims.

Referring to the parts by letter, A B represent the two supporting-standards of the hammer suitably connected by cross-bars and fixed upon a common base, and C a crank-shaft extending between and journaled in the upper ends of said standards. This shaft has pulleys c, for connection with the driving-power, and

a weighted y-wheel, c', all of which are of common construction and use. The crank part c2 of said shaft lies between said standards, and a link connects said crank with the cylinder E. Both standards A B are provided with the grooves a t), respectively, whichserve as guides for the cylinder E, and also for the tup E. A rod, II, connects the tup with the 5o piston I in the air-cylinder, and said piston is free to play within said air-cylinder, subject to the Inovements of the cylinder and the airpressure at its respective ends, as hereinafter explained. On the front side of the cyl- 5 5 inder are placed two air-induction valves, c e', similar in construction and operation, one in the upper and one in the lower half thereof. These valves have air-passages through the stems e3, upon which they slide, and lateral 6o openings e2, connecting with said passages for the passage of air into the cylinder. Crossbars L' are set into the screw-plugs supporting the valves, which permit just enough play to said valves to clear the air-openings e2, which 6 5 openings are closed when the valves are seated. Obviously the form of valve is not material, and any valve having a similar Inode of operation may be substituted for the form shown.

The cylinder E is provided with an open 7o Vent, Z, situated so that the piston passes it at each stroke. In the upper part of the cylinder, and, for convenience of mechanical construction, in the rear side thereof, is placed an eduction-valve, L, fashioned substantially like the valves e e. The screw-plug M, which supports said valve L, is provided with a recess, l', in which is placed a spring, Z2, arranged to thrust against the valve and the head of the stem Q, which passes out through 8o the end of said screw-plug. Lateral vents m are formed in said screw-plug` for the escape of air, which is forced through said valve. Normally this spring offers but little resistance to the movement of the valve, and the air escapes freely therethrough, whereby the cylinder is permitted to move up and down, while the piston and tup are held stationary by the brake hereinafter described; but when the spring is compressed and offers the great- 9o est resistance to the escape of air, and when the brake (if one be used) is released, the downward movement of the cylinder causes the air in the upper end thereof (which cannot now escape) to be compressed, whereby the piston is driven downward and the stroke of the hammer delivered. The compressed air in the upper end of the cylinder acts as a spring, which protects the parts from strain and prevents any rebound of the hammer,

thereby rendering its stroke dead The i main standards of the frame.

air in the lower part of the cylinder, having no means of escape, is compressed as the cylinder moves upward, forming an air-cushion below the piston, whereby the same is raised in the ordinary manner.

For the purpose of compressing the spring Z2 to increase the resistance of the valves L to the internal air-pressure while the cylinder is in motion, I provide the device herein shown, to wit: a substantially wedge-shaped slide, N, set in a groove, 0, in an inclined block, O, supported on standards o', att-ached to the The block O has a vertical slot, o2, through which the slide N is held in position by means of a bolt, fn, passing through the slot and slide, and a rod, P, connects the slide with the weighted treadle R below. Accurately speaking', the slide is beveled on "its back and presents a straight side to the headed stem Q, which bears against the spring Z2. The operator presses the treadle R downward, which moves the slide N upward and forces in the headed stem Q, thus compressing the spring and increasing to any desired extent the resistance of the valve to the internal air-pressure.

The brake mechanism consists of a brakeblock, S, set into a recess in the standard A at a point where its entire surface is in contact with the tup when the same is raised; but only a part of said surface engages with said tup when the same is in its lowest position. This block is controlled by a wedge or tapered locking-piece, T, fitting in a wedgeshaped groove in the standard behind the brake-block, said wedge being attached to an arm, fu, on the rock-shaft V, through av pin on the wedge and a groove in said arm o. This shaft is provided with a hand-lever, W, and a rod, X, connects the lever with the treadle R. Either the lever or the treadle may be used to operate the brake.

The weight on the treadle is sufficiently heavy to drive the wedge T to its seat with such force as to effectually lock the tup and prevent its movements. A further effect of this brake, an din conjunction with the springpressed valve L, is to vary at will the force of the blows delivered by the hammer.

When the treadle R is pressed downward with sufcient force to stop the motion of the tup, it will be found that said tup stops when at or near its highest position. This results in part from the position of the valve, as explained, whereby when the pressure device is withdrawn the air is permitted to escape from the cylinder above the piston -head, thereby reducing the force to push said piston downward, and also in part from the position of the brake-block, as explained,where by the friction or braking surface is greatest when said tup is raised.

The continued motion of the tup tends to wear both the tup and the guides in the standards A B, and the action of the brake is to force said tup against the standards B. This, when there had been any considerable wear,

would force the piston-rod to one side, interfere with the perfect working of the device, and probably soon bend the rod and render the device wholly inoperative. To compensate for this Wear, I set into the standards B, at a point where the tup is always in engagement with it, an adjustable plate, G. In the form shown the plate is held to the standard by bolts, and it may be adjusted as found necessary by interposing packing between said plate and standard.

I do not understand my invention to be confined to the details of construction herein described and shown.

Many changes in mechanical construction, it is evident, may be made without making any essential change in the novel principle and mode of operation herein disclosed, and I do not wish to be considered as limiting myself to details further than expressed in the claims.

In the operation of the larger-sized hammers it may be found desirable to have a small vent in the upper part of the cylinder to measurably reduce the atmospheric pressure therein, and when this occurs I form an opening for the purpose in the upper head of the cylinder. It will be understood, also, that the pneumatic cylinder may be provided with other air-openings than those shown and described without departing from the spirit and scope of my invention.

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

1. In a pneumatic hammer, a reciprocating cylinder having suitable valved air-inlets and an air-outlet provided with an outlet-valve, in combination with a pressure device for increasing the resistance of said outlet-valve, substantially as specified. i

2. In a pneumatic hammer, a reciprocating cylinder having suitable valved air-inlets, an air-outlet, and a spring-pressed valve to said outlet, in combination with a pressure device for increasing the resistance of said spring, substantially as specified.

IOO

IIO

3. In a pneumatic hammer, a cylinder havcylinder, and a piston working in said cylinder and connected by a rod with the tup, in combination with a brake arranged at the side of the tup, substantially as set forth.

6. In a pneumatic hammer, a crank-axle and an air-cylinder attached to the crank and reciprocated thereby, in combination with a tup, a rod and a piston connecting the tup with the cylinder, and a frictional brake for the tup, substantially as set forth.

7. In a pneumatic hammer, a reciprocating air-cylinder having a springepressed outletvalve, a piston-rod, and tup, in combination with a brake arranged at the side of said tup and a pressure device for increasing the resist-ance of said outlet-valve, substantially as set forth.

S. In a pneumatic hammer, a reciprocating air-cylinder having a spring-pressed outletvalve, a piston-rod, and tup, combined with a pressure device for said valve, a brake for said tup, a treadle, and devices connecting said pressure device and brake with said t-readle, substantially as set forth.

9. In a pneumatichammer, a reciprocating cylinder, piston, piston-rod, and tup, combined with a brake arranged at one side of the tup and an adjustable plate arranged at the other side of said tup, substantially as and for the purpose specified.v

l0. In a pneumatic hammer, a reciprocating air-cylinder, an outlet-valve in the upper end thereof, a hollow valve-plug, and a spring contained therein, combined with a headed stem, Q, and a sliding Wedge, substantially as and for the purpose specified.

1l. The combination of the upright standards A B, having' the guides a b on their proximate surfaces, a crank-shaft journaled in and extending from one to the other of said standards with a cylinder, a link connecting the said cylinder and crank-shaft, piston-rod, and tup, said cylinder and tup being guided in their movements by said grooves c b, substantially as and for the purpose specified.

GILBERT GLOSSOP. [L s] In presence of HERBERT BRAMLEY,

Solicitor, Shejjeld, England. J oHN MAXFIELD,

His Clerk.

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