US1024669A - Pneumatic percussive apparatus. - Google Patents

Description

H. C. BEHR.

PNBUMATIG PERcUssIvE APPARATUS. APPLIGATION FILED NOV. 9, 1910.

' Patented Apr. 30, 1912.

z SHEETS-SHEET 1 I I: (a I I I I l I l I I I I I I I I I l I I I I I v .A I 2 A l/I/Lbl/ COLUMBIA PLANOGRAPH C0., WASHINGTON. D.

H. c. BEER. PNEUMATIG PBROUSSIVE APPARATUS.

I APPLICATION ILED NOV. 9, 1910. 1,024,669.

Patented Apr. so, 1912.

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HANs CHARLES BEHR, or JoHANNEsBURe, TRANsvAAL.

PNEUMATIC PERCUSSIVE APPARATUS.

To all whom it may concern: p

Be it known that I, HANS CHARLES BEHR, consulting mechanical engineer, a citizen of the United States of America, residing at Consolidated Goldelds Buildings, Johannesburg, Transvaal, have invented new and useful Improvements in Pneumatic Percussive Apparatus, of which the following is a specification.

The present invention relates to pneumatically actuated stamps and other percus` sive machines, of the kind in which motion is transmitted from a positively reciprocated member to a percussive member by means of a cushion or cushions of air, the pressure of which is always higher than that of the atmosphere. In such apparatus as heretofore known, a fixed cylinder has been employed in which worked two pistons, one of which was reciprocated positively and the other of which formed part of the percussive member. The cushion of air between the adjacent faces of the pistons propelled the percussive piston forward upon its working stroke, while the pressure for effecting the return of the percussive member was afforded in some cases by an air cushion formed by making suitable connections between the extreme faces of the pistons, or in other cases by a body of fluid kept at constantpressure or by a combination of both systems. In order to produce sufficiently positive transmission of motion during the working stroke it was necessary to have as small a cushion as possible between the adjacent faces of the pistons, which condition however conflicted with the necessity of providing for variation of the stroke of the percussive member due,

. for instance, to the presence under the stamp of larger or harder pieces of material than those for the reduction of which the stamp was designed.

The present invention is illustrated in the accompanying drawings, in which- Figure I is a partly sectional elevation of a stamp constructed according to the invention; and Fig. II is a similar view of a modified construction.` p

According to this invention, one member is formed with a cylinder l and the other with a piston 2 working therein. Either of such members may be arranged for positive reciprocation. Thus, in the construction shown in Fig. I, the cylinder 1 is reciprocated by means of crank 3 and connecting rod 4l, the piston 2 then forming part of the Specification of Letters Patent.

Application led November 9, 1910.

`connections hereafter described.

Patented Apr. 30, 1912.

serial No. 591,480.'

percussive member. As shown in Fig. II, the stamp head 5 is formed at its upper end with a cylinder l within which works the piston 2 which'is reciprocated by the crank 3 and connecting rod 4.

Between the respective piston and cylinder faces 6, 7, which tend to approach during the working stroke, is formed a chamber 8 within which a body of air is maintained at pressure higher than that of the atmosphere. For this purpose, an air compressor 9 supplies a receiver l0 from which air is passed freely to the cylinder by the The pressure of the body of air in chamber 8 is constant apart fro-m such slight variation as is due to some of the air having to flow in and out of the cylinder to and from the receiver l0 during the relative reciprocating movementof the piston and cylinder. Upon the opposite side of the piston 2 is formed a chamber l1 inclosing a body of air. By the reciprocation of the positively reciprocated member such body of air is alternately rarefied and compressed, thereby giving rise to reciprocation of the percussive member.

Both bodies of air contained in chambers 8 and 1l respectively, are permanent in the sense that they are not successively fed in and exhausted; nor, in the preferred method of operation, are portions of them exhausted at intervals and replaced by fresh air to prevent over-heating, as in some types. Once -t-he compressor 9 has initially filled the receiver l0 and the chambers 8 and 11, its function is merely to make up air lost by unavoidable leakage.

In practice, the mean relative position of vthe parts is so adjusted that the body of air in chamber 8 is comparatively large and that in chamber l1 comparatively small. The

bounding faces 6 and 7 of chamber 8 being those which tend to approach during the working stroke, their wide separationA obviates danger of their colliding during the working stroke; while on the other hand, the smaller chamber l1 is, the greater becomes the variation of pressure therein and the more nearly positive becomes therefore the transmission of motion to the percussive member.

The mean pressure of the air within chamber 1l is maintained above atmospheric pressure, usually by affording restricted communication between it and chamber 8 which is itself in free communication with a source of supply, as already stated. For this purpose, there may be formed through the piston Q, a passage 12 so small in area vt-hat only a very small quantity of air can pass through it during one stroke of the apparatus. Alternatively, adjustable spring-controlled valves adapted to pass air between the two faces of the piston as described in my pending application Serial No. 532090 may be employed.

rlhe cylinder 1 is provided with a water jacket 13 for removing excess heat generated in the air bodies, and in the case of an ore stamp, the more or less warm water passed out from the jacket may be conveyed into the mortar box 14. To this end, as shown in Fig. l, pipes 15 extend from the bottom of the water jacket, by which the water directed into a cup-shaped recess 1G in the top of the stamp head 5; whence it passes by passage 17 and branches 18 to the peripheryT of the stamp head or by a branch 19 to the face thereof. Similarly, in the Fig. Il construction in which the jacket 13 surrounds the cylinder 1 formed in the stamp head 5, said passages carry away the water directly from the jacket.

Provision is made in the case of a stamp for adjusting the mean position of the percussive member to compensate for its wear and that of the die upon which it works. In the construction shown, the crank 3 and positively reciprocated member are mounted upon a frame 2O which is adjustable upon a fixed frame 21. Adjustment is effected by such means as the screw 22, working through a threaded lug 23 on frame 20. 24 indicates bolts for clamping frame 20 in position. In the case of a stamp in which the stamp stem is the reciprocated member, a further adjustment may be arranged, viz. that of the stamp head 5 with respect to its stem 1n Fig. I is illustrated a parallel-sided stem fitting into a similar socket 26 in the head 5. 27, 2S, are two wedges which are inserted between the stem and the head, and are tapered in opposite directions. The one 27 tapering downwardly is furnished with a head 29. In securing the head 5, such wedge 27 is fixed by placing a stop under its head 29, wedge 28 being then driven home. Release of the parts when required is effected by driving in the headed wedge 27.

For making connection between the receiver 10 and the cylinder 1 and to supply water to jacket 13 any suitable connecting means conformable to the movement of the cylinder relatively to xed parts, may be employed. ln Fig. I there is shown for this purpose a device comprising a pair of links 30, 31. Link 30 is pivoted to fixed parts and stands substantially vertically or parallel with the direction. of motion of cylinder 1. Link 31 is pivoted both to link 30 and to the cylinder 1 and in its mean position projects substantially perpendicularly from the latter. Said links support flexible piping for conveying the fluids, which piping may in some cases consist merely of rubber hose; but as shown in the drawings consists of sections of rigid pipe 32 connected by lengths of hose 33. A similar system of piping secured to the hidden side of the links supplies water from a source 34 to the jacket 13. This arrangement provides a cheap and effective connection, using hose to afford the requisite flexibility without causing thrashing or undue liexure of the same.

In Fig. Il water is supplied to the jacket 13 through a pipe 35 fixed to the movable frame Q0 and projecting into the jacket parallel with the direction of motion of the latter. The air supply is furnished by means of a hollow guide 36 through which the piston rod 37 passes. Stufing boxes 38 are provided at the ends of the guide 36 and, a supply pipe 39 from the receiver 10 is taken to the interior thereof. A passage 40 is formed through the piston rod 37 which passage communicates at its lower end with chamber 8 and opens at 41 in the side of the rod at such a position as always to communicate with the hollow interior of the guide 36.

The stamp head 5 works through a guide 4Q, and to avoid lubricant, used in the guide, dropping into the mort-ar box 14 and so impairing metallurgical operations, the head is formed with an enlarged upper part 43 which works in the guide. The junction of said enlarged. part with the relatively reduced lower part of the head is undercut to provide a projecting lower edge 44. Such edge throws excess lubricant clear of the opening 45 through which the lower part of the head enters the mortar box; such lubricant being conveniently collected in an annular trough 46.

What 1 claim and desire to secure by Letters Patent is :d

1. A structure comprising in combination a rcciprocable cylinder member, a second rcciprocable member furnished with a piston working in said cylinder, one of said members being provided with a stamp head, means for positively reciprocating one of said members, means for maintaining a body of air at a pressure always higher than that of the atmosphere on one side of the piston, said structure having a restricted passage way for maintaining a body of air on the other side of the piston at an average pressure higher than that of the atmosphere.

2. A structure comprising in combination, a rcciprocable cylinder member, a second rcciprocable member embodying a piston working in said cylinder and also a piston rod, one of said members being provided pressure higher than that of the atmoswith a stamp head, means for maintaining phere. 10 on the side of the piston unoccupied by the In testimony whereof I aiiix my signature piston rod a permanent body of' air at a in presence of tWo Witnesses.

pressure always higher than that of the at- HANS CHARLES BEHR. mosphere, said structure having a restricted Witnesses: passage Way for maintaining a body of air WESLEY E. JOHN,

on the other side of the piston at an average C. B. HENDERSON.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington, D. C.

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