US573260A - Impact-tool - Google Patents

Description

(No Model.) 2 Sheets-Sheet Il* Je l n GT TO No. 573,260. Patented Deo. 15, 1896.

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J. P. CLEMENT.

IMPACT TOL No. 573,260. Patented Deo. l5, 1896,

Ffa@ Fjdff UNITED STATES .1

PATENT OFFICE.

JOHN F. CLEMENT, OF PHILADELPHIA, PENNSYLVANIA, ASSIGN OR TO THE CLEMENT PNEUMATIO TOOL COMPANY, OIF

OAMDEN, NEW JERSEY.

, IM PACT-TOOL.

A SPECIFICATION forming part of Letters Patent No. 573,260, dated December 15, 1896.

Application filed May 7,1896. Serial No. 590,561. (No model.)A

To all whom it may concern,.-

Beit known that I, JOHN F. CLEMENT, a citizen of the United States, residing in Philadelphia, Pennsylvania, haveinvented certain Improvements in ImpactTools, of which the following is a speciiication.

One object of my invention is to so construct an impact-tool of the valveless class as to prevent side pressure upon the reciproro eating piston or hammer, a further object being to arrest the reciproeation of the hammer except when the tool is at Work, and a still further object being to adapt the tool for use with different kinds of chisels orcutting-tools. Theseobjectslattain in the manner hereinafter set forth, reference being had to the accompanying drawings, in which*- Figure l is a longitudinalsection of anin1- pact-tool constructed in accordance with my 2o invention. Fig. 2 is a similar view showing the piston or hammer in a different position. Fig. 3 is a transversesection on the line 3 3, Fig. l; and Fig. 4 is a View of a special form of hammer constituting part of my invenz 5 tion.

In Figs. l, 2, and 3, A represents the cylinder of the tool, which has at the rear end a cap B, lirmly secured thereto by screwing it into the end of the cylinder, a spring-plug d,

3o carried by the cap and adapted to an opening in the cylinder, serving to prevent the unscrewing of said cap un til said plug has been first pushed inward, so as to be free from engagement with the cylinder. The cap is bored 3 5 out centrally to receive the enlarged forward end of the stem b of a handle F, said stem being seated upon a block or Washer b', of rubber or other elastic material, located at the inner end of the opening in the cap,

4o which block` is slightly compressed by .they stem of the handle, the latterbeing retained 3 in longitudinal position to insure such compression by means of an annular Washer b2, of elastic material, bearing upon the shoulder formed by the enlargement of the stem h,

and retainedin position by an annular retainer D, screwed into the outer end of the cap B. By this means the handle F is confined to the cylinder A in a longitudinal di- 5o rection, but yet is free to turn or swivel on the cylinder to suit the convenience of the workman using the tool, the elastic cushions preventing any shock yrjar from being transmitted to thehandle. X

Snugly fitting in the bore of the cylinder -5 5 is the reciprocating piston or hammer G, which has extending transversely through it an opening f, which is always in communication with an inlet-porti in one side of the cylinder, this inlet-port communicating 6o in any suitable manner with a supply of motive fluid under pressure.

In the present instance the tool is intended for use with compressed air, and the inletport i is in vcommunication with a nozzle t, to which the aireonveyer pipe is directly applied, but any other available means of conveying the motive iiuid to the inlet-porti' may be adopted without departing from my invention. 7o

In the side of the cylinder opposite that having the inlet-port are two double-ended conveyer-ports m and n, t-he rear end` of the rear port m communicating with the rear end of the cylinder and the forward end of the forward port n communicating with the 'forward end of said cylinder. In the cylinder are also formed two exhaust-ports s and t, the port s serving to permit of the escape of motive fluid from the rear end of the cylinder 8o and the port t providing for the escape of motive fluid from the forward endof the cylinder, these ports by preference being independent of each other and each consisting of inner and outer radial portions connected by a longitudinal passage, so that while they provide for the free escape of motive liuid from the cylinder they will prevent the access of sand, metal chips, or other foreign matters into the cylinder. The rear exhaust-port is 9o preferably of less area than the forward exhaust-port, so as to provide fora freer escape f motive iiuid from the front end of the cylinder than from the rear end of the same.

The piston or hammer G has a forwardlyprojecting stem G', which is guided in the for! ward end of the cylinder and acts upon the inner end of the stem or shank H of the chisel or other tool which is being used, the latter being guided in an opening at the forward end roo ot' the cylinder, to which it fits with reasonable snugness. AThe stem G' when projected enters a chamber ol, which is of slightly greater diameter than the opening in whichy said stem is guided and has a lateral vent CW, so as to prevent the possibility of any cushioning of the blow by the compression of air in advance of the hammer-stem.

In the lower portion of the piston G is formed a right-angled opening w, one portion of which extends to the forward end of the piston, while the other portion extends to one side of the piston in line laterally with the lower exhaust-port t.

The operation of the tool is as follows Vhen the parts are in the position shown in Fig. 2, the piston G is at the rear end of its stroke, the port t is uncovered, so as to permit the free escape of motive iiuid from the forward end of the cylinder, and the forward end of the port m is in communication with the transverse passage f of the piston, so that motive iiuid ows freely from the inlet-port 2'. through said passage, and thence through the port m to the rear end of the cylindeigin order to drive the piston forward. After the projecting 'stem of the piston has delivered its blow upon the inner end of the tool-stem the ports are in the position lshown in Fig. l, the exhaust-port s being now open, so as to permit of the escapeof motive lfluid from the rear end of the cylinder, and the forward port n being in communication with the -transverse passage f of the piston, so that motive fluid is directed to the forward end of the cylinder in order to drive'the piston rearward therein, this rearward movement continuing until the parts again assume the position shown in Fig. 2, prior to a repetition of the before-described operations. Vhen the cutting-tool is not being used, or is not pressed firmly against the work, the piston or hammer G will on its forward movement meet with no resistance, or less than the normal amount of resistance, from the tool, and hence will pass forward beyond its normal point, thus opening communication between the'passage w in the piston and the exhaust-port t. The air which had entered the forward end of the cylinder before the piston completed its excessive forward stroke escapes therefrom through the passage fw and exhaust-port t, so that after the port t' is closed `by the forward movement of the piston there is no pressure'in the forward end of the cylinder to drive said piston rearward. vHence the parts will remain inoperative until the tool is again pressed upon the. work with sufficient force to move the piston backward to such an extent as to again open the inlet-port t'.

In the construction shown in Fig. -t the piston G2 is provided with adetachable stem G3, which is intended to be of such length that its forward end will project beyond the cylinder, so that it can be adapted to a socket at the end of the tool-stein, as shown by dotted lines, the forward end ofthe stem G3 also by preference having a socket formed in it, so that it can be applied to an ordinary toolstem as well, if desired. By forming a passage directly through the piston from one side to the other for the conveyance of motive fluid from the inlet-port to the conveyer-ports of the cylinder I avoid side pressure, which invariably results when the passage is in the form of an annular groove in the piston and which is due to the impingement of the motive fluid upon t-he central or reduced portion of the piston. I therefore reduce the friction upon the piston and facilitate the reciprocation of the saine and at the same time prevent wear of either piston or cylinder due to the lateral lpressure upon said piston.

Having thus described my invention, I claim and desire to secure by Letters Patent- 1. The combination in an impact-tool, of a cylinder having an inlet-port, and conveyerports, one of the latter ycommunicating with one end of the cylinder and the other with the opposite end of the same, with a piston reciprocating in said cylinder and having an opening transversely through it which serves to convey the motive fluid from the inlet-port to the rconveyer-ports alternately as the piston is reciprocated, whereby side pressure upon the piston is prevented.

2. The combination in an impact-tool, of a cylinder having an inlet-port, conveyer-ports, one communicating with one end of the cylinder, and the other with the opposite end of the same, and exhaust-ports for the opposite ends of the cylinder, with a piston reciprocating in said cylinder and serving by its movements to direct motive fluid first to one end of the cylinder, and then to the other end of the same, and an escape-passage formed in said piston and serving to open communication between the forward end ofthe cylinder and the forward exhaust-port, on excessive forward movement of the piston in the cylinder.

3. The combination in an impact-tool, of a cylinder, ya piston reciprocating therein, and a stern detachable from said piston, and projecting forwardly beyond the cylinder, said stem being constructed at its forward end for the reception of a tool-stem.

4. The combination of the cylinder, with the vhan dle'confined longitudinally to the cylinder, but free to turn independently thereof.

5. The combination of the cylinder, with the handle having an elastic longitudinal connection with the cylinder but free to turn in respect to the cylinder.

G. The combination lof the cylinder, with the handle having a stem with enlarged end, elastic blocks or washers engaging the forward and rear portions of said enlargement of the stem, and a confining-rin g for said rear washer.

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

JOHN F. CLEMENT.

Witnesses:

F. E. BEcHToLD, J os. H. KLEIN.

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