US665033A - Pneumatic tool. - Google Patents

Description

c. B". RICHARDS. PNEUMATIC ToqL.

No. 6%,033. Patented Jan. 1, l90l.

(Applicgtion filed Dec. 6 1899.) (No Model.) v 3 sham-sheet No. 665,033. Patented' Jan. I, "19m.

C. B. RICHARDS.

PNEUMATIC TOOL.

(Application flied Dec. 6, 1899.) (No Model.) 3 Sheets-Shgt 3.

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UNiTED STATES LATENT Creme.

CHARLES E. RICHARDS, OF CLEVELAND, OIIIO, ASSIGNOR TO THE CLEVE- LAND PNEUMATIO TOOLOOMPANY, OF SAME PLACE.

PNEUMATIC TOOL.

SPECIFICATION forming part of Letters Patent No. 665,033, dated January 1, 19012 Application filed December 6, 1899. Serial No. 739,410. (No model.)

State of Ohio, have invented certain new and 4 useful Improvements in Pneumatic Tools, of which the following is a specification, the principle of the invention being herein explained and the best mode in which I have contemplated applying that principle, so as to distinguish it from other inventions.

The annexed drawings and the following description set forth in detail one mechanical form embodying the invention, such detail construction being but one of various mechanical forms in which the principle of the invention may be used.

In said annexed drawings, Figure I represents an axial section of my improved pneumatic tool, showing the plunger and valve in their positions at the end of the back stroke of the plunger immediately before the valve is shifted for the operative stroke; Fig. II, an axial section of the tool, showing the plunger at the end of its operative stroke and before the valve is shifted; Fig. III, an axial section in a plane at right angles to the plane of the former sections; Fig. IV, a transverse section on the line IVIV in Fig. I and looking forward; Fig. V, a transverse section on the line V V in Fig. I; Fig. VI, a transverse section on the line VI VI in Fig. II; Fig. VII, a transverse section on the line VII VII in Fig. II; Figs. VIII and IX, respectively a rear view and a front view of the cap, and Fig. X a rear end view of the barrel.

The hammer has a barrel 1 formed with an annular shoulder 2 at its inner end. A cylindrical valve-casing- 3 has a bearing with its closed end against the shouldered end of the barrel, and a cap 4 bears against the other end of the valve-casing, closing said end. A sleeve 5 has an internal flange b and is slipped over the barrel to have said'flange engage the shoulder of the barrel, and said sleeve has an external screw-thread which is engaged by an internally-screw-threaded sleeve 7, from which a pistol-grip handle 8 extends. The barrel has a bore 9,wl 1ich forms the plungercylinder and terminates in a smaller bore at the end of the barrel, into which bore a toolsocket 10 is forced. The shank 33 of the working tool fits in said socket. The plunger-cylinder is formed with an enlargement 11 in its outer end at the inner end of the tool-socket. A plunger 12 fits to reciprocate in the cylinder and has two pistons 13, a reduced portion 14 between said pistons, and a reduced nose 15 at its outer end, which nose engages and strikes the end of the tool-shank. The actuating fluid, which is usually compressed air, enters the handle at the end of the same and passes through a channel 16 in said handle. The air-tube 17 is screwed into the open end of a valvecasing 18, which is cylindrical, and is secured transversely through the end of the handle, in which is formed an annular chamber 19, communicating with the air-channel in the handle, and a longer annular chamber 20, opening through the handle and closed by a screw-plug 21, through which the valve-casing is screwed. Immediately at the end of the screw-plug the valve-casing has an annular series of perforations 22, forming a port communicating with the larger chamber, and a partition 23 is formed inthe valve-casing directly above such port. An annular series of perforations 24, forming a port, is formed through the valve-casing .at the inner end of the large annular chamber. The interior of the valveoasing communicates with the small annular chamber and the air-channel through an annular series of perforations 25, forming a port. A valve 26, having a cup-shaped piston 27 at its inner end and a packing-piston 28 near its outer end, slides in the valve-casing and is forced outward by a spring 29, fitted in the cup-shaped piston and bearing against the partition in the valve-casing. The end of the valve-stem 30 projects through the side of the handle, and a lug 31 upon a latch 32 bears against it. Said latch is fulcrumed at one end upon the inner, side of the handle, so that the latch may be pressed by the hand holding the handle to force the valve in and be released to cause the valve to slide out by the action of the spring of the latter. When handle. When the latch is pressed and the valve forced in, said latter port is uncovered and the air may flow through it and the interior of the valve casing out through the other port into the air-channel. A small hole 34 is preferably formed through the cupshaped piston for the purpose of equalizing the pressure upon both sides of the valve.

The above described valve mechanism forms the throttle-valve mechanism of the hammer, by means of which the supply of air to the hammer is controlled. The air-channel 16. opens into the closed end of the sleeve of the handle and enters a recess 35 in the rear face ofthe cap 4. A channel 36 extends through the cap, near the periphery of the same and from the recess, and said channel registers with and is continued bya channel 37 in the valve-casing and, further, by a channel 38 in the side of the barrel. Two ports 39 and 40 open from said channel into the plunger-cylinder at about equal distances from and near the middle of the same. The actuating-air is continually admitted in said channel when the throttle-valveis open. The valve-casing has a cylindrical valve-chamber 41, closed at its forward end by a wall of the casing and at its rear end by the cap. A valve 42, having a central piston 43 and end pistons 44 and 45, slides in said valve-chamber. Two ports 46 and 47 open from the airinlet channel into the valve-chamber in such manner that one of the channels between the central piston and the end pistons may alternately register with one of said ports as the valve is reciprocated and arrives at the extremes of its play. The valve-casing is surrounded by an exhaust-chamber 48, formed by the handle-sleeve and the flanged sleeve, and one or more ports 49 open from said exhaust-chamber through the handle-sleeve. Exhaust-ports 50 are formedthrough the valve-casing from the two extremes of the valve-chain berinto the exhaust-chamber, and said exhaust-ports are of a comparatively small diameter and area and are permanently open to the exhaust-chamber, so that air may be exhausted from the ends of the valve-chamber when the valve therein is forced toward the ends, while admission of live air into the ends of the valve-chamber will shift the valve, with only a small quantity of air leaking out through the exhaustport. Two large ex-. hanst-ports 51 and 52 are formed from near the middle of the valve-chamber through the casing and into the exhaust-chamber. Said ports are so arranged that the rear exhaustport 51 will register with the rear valve-channel when the forward live-air port 47 registers with the forward valve-channel at the forward extreme of the valve throw and the forward exhaust-port 52 will register with the forward valve-channel when the rear live-air port 46 registers with the rear valve-channel at the rear extreme of the valve throw. A

channel 53 extends from the enlargement at the forward end of the plunger cylinder through the side of-the barrel and through the side of the valve-casing, and said channel has a port 54, which registers with the forward exhaust-port 52, and a port 55,which registers with the forward live-air port 47. A recess 56 is formed in the rear end of the plungercylinder and communicates with a channel 57 through the side of the valvecasing. Said channel has two ports 58 and 5.), of which the forward, 59, registers with the rear exhaust-port 51 and the rear, 58, registers with the rearlive-air port 46. Achannel 60 extends from the forward end of the valve-chamber to a port in the plunger-cylinder registering with the rear inlet-port 39. A channel 61 extends from the rear of the valve-chain her, where a recess 62 is formed in the forward face of the cap 4, to a port in the plunger-cylinder, which registers with the forward inletport 40. A shallow channel 63 is formed in the forward face of the closed end of the valve-casing to form a small permanent inlet from the live-air-inlet channel to the rear end of the plunger-cylinder. The rear edge of the flanged coupling-sleeve 5 is formed with ratchet-teeth 64, which are engaged by a pawl 65, sliding in the handle-sleeve, to prevent the parts from turning and unscrewing during the operation of the hammer. Said pawl has a spring 66, forcing it into engagement with the ratchet-teeth, and a pin 67 ex.- tends from the pawl through an L-shaped slot 68 in the handle-sleeve, so that the pawl may be locked in its disengaged position by turning the pin into the lateral notch of the slot.

In practice the air-inlet of the handle is connected to a source of air under pressure by means of a hose or similar flexible or movable connection. When the latch is pressed inward by the hand holding the grip of the handle, air is admitted to the hammer. When the tool is notinserted in the hammer, the plunger is in the position shown in Fig. III, and the port which conducts the live air to shift the valve from the forward to the rear position is closed and the live air let into the outer end of the plungencylinder will escape through the tool-socket, so that the hammer will remain inoperative until the tool is inserted, even though the air is admitted into the hammer. When the tool is inserted, the plunger is pushed back and the outer end of the plunger-cylinder is closed to allow the air passing down to said end to return the plunger. The valve is in the position illustrated in Fig. I and the plunger in the position shown in Fig. II. The live air will pass from the inlet-channel through the forward live-air port and valve-channel to the forward port of the channel leading to the outer end of the plunger-cylinder, forcing the plunger back into the position in Fig. I. The back stroke of the plunger will force the air behind the plunger through the recess 56 and channel 57 to the forward port 59 ofthe same, whence itwill pass through the IIO valve-channel and registering exhaust-port into the exhaust-chamber and thence out of the hammer. At the end of the back stroke the plunger will be cushioned by the live air entering the rear end of the plunger-cylinder through the permanently-open shallow channel 63. When the plunger arrives at the end of the back stroke, communication is made between the rear inlet-port in the cylinder and the. registering port of the valve-shifting channel 60, so that air may pass through said channel into the forward end of the valve chamber, shifting the valve back into the p0 sition shown in Fig. II. This will place the rear live-air port in communication through the rear valve-channel with the port 58 and channel 57, leading to the rear end of the plunger-cylinder, admitting the live air behind the plunger to drive the same forward. The air in front of the plunger escapes through the channel leading from the forward end of the plunger-cylinder and through the rear port of said channel through the valve-channel and out through the forward exhaustport of the valve-chamber. When the plunger reaches the end of its forward stroke, the valve is again shifted by communication formed between the plunger-pistons from the forward live-air inlet-port in the plunger-cylinder to the valve-shifting channel-port registering with said inlet-port, thus admitting live air to the rear of the valve and forcing the latter forward. While the valve is shifting the exhaust from the forward end is momentarily shut off. The enlargement of the plunger-cylinder at that end will, however, admit of the small volume of confined air escaping to the sides of the plunger, so as not to cushion the forward blow of the plunger upon the tool-shank in the tool-socket.

ward throw of the valve, the back jar of the plunger striking the tool is partly or entirely neutralized by the forward jar caused by the throw of the valve, so that a very slight jar only is felt by the hand holding the hammer. This is a great advantage in this kind of a tool, as the operators of this kind of toolfrequently suffer considerably from the severe jar to the hand and arm during the operation of the tool to such extent as to render the continued operation of the tool for any considerable space of time impossible. The air exhausts from the ends of the valvechamber through the small exhaust-ports in the ends of the same, which ports have so much less area than the inlet-ports into the ends of the chamber that they Will permit the live air to shift the valve with a comparatively small escape of said air through the ports, while they will allow the exhaust-air to escape when the valve is forced over by the pressure of live air on the opposite side of the valve.

When it is desired to take the hammer apart for inspection or repair,the pawl is withdrawn As the forward blow of the plunger is immediately followed by the forfrom the ratchet-teeth of the-coupling-sleeve v and the handle is unscrewed from said sleeve. The sleeve may then be pushed down upon the barrel and the valve-casing and cap may be removed, giving free access to the valve and the plunger.

There are no small'parts in this hammer to be injured by the hard usage to which a tool of this character is subjected and to consequently impair the usefulness of the ham mer; All parts are easily constructed and are easily accessible. The valve-actuating mechanism is very much simplified by having the small permanently-open exhaust-ports in the ends of the valve-chamber, as the number of ports and channels and corresponding controlling mechanism is reduced, and the Waste of air pistons and conducting the air directly to the channels leading to the respective ends of the valve-chamber. The construction of the hammer is also simplified by using the same channel at the forward and rear end of the plu ngercylinder for inlet and exhaust, so that the drilling of channels and complication of valvecasing ports and of the valve structure is avoided. The pawl-and-ratchet device upon the handle-sleeve and coupling-sleeve will prevent said parts from unscrewing by the jar of the operating-hammer, and the pawl may be easily withdrawn and held whenever it is desired to take the hammer apart. The throttle-valve is easily controlled, as the grip of the hand holding the handle-grip during operation of the hammer will pull on the latch and keep the valve open, and release of such grip will immediately release the latch and shut off the air. From practical use of the hammer it has been proven that hardly any jar is experienced to the hand holding it dur ing operation, but that the upward jar from the plunger striking the tool is neutralized by the immediately-following downward jar of the solid valve being thrown forward toward the forward end of the valve-chamber. The cushioning effect to the forward stroke of the plunger of the slight quantity of air confined in the outer end of the plunger-cylinder by the change ot the valve and consequent cutolf of the exhaust from that end is removed by the enlargement of the outer end of the cylinder,which allows the plunger to laterally displace the air and to thus strike the tool with its full force Other modes of applying the principle of my invention may be employed for the mode herein explained. Change may therefore be -IIO made as regards the mechanism thus disclosed,provided the principles of construction set forth respectively in the following claims are employed.

I therefore particularly point out and distinctly claim as my invention 1. In a pneumatic tool, the combination with a barrel formed with a plunger-cylinder and a valve-casing arranged in axial alinement with and at the inner end of said barrel, of a plunger reciprocating in the barrel, a distributing-valve reciprocating in the valvecasing, and means for causing the valve to be thrown forward immediately following the forward throw of the plunger, thereby neutralizing the back jar from the plunger striking the tool, substantially as set forth.

2. In a pneumatic tool, the combination with a barrel formed with a plunger-cylinder and a valve-casing arranged in axial alinement with and at the inner end of said barrel, of a plunger reciprocating in the barrel and a distributing-valve reciprocating in the valvecasing and actuated by the actuating fluid, said plunger being constructed to control the actuating fluid to throw said valve in such manner that the forward throw of the plunger admits the actuating fluid to the valve to throw the latter foward, thereby neutralizing the back jar from the plunger striking the tool, substantially as set forth.

3. In a pneumatic tool, the combination with a barrel formed with a plunger-cylinder, and a valve casing arranged in axial alinement with and at the inner end of said barrel, two inlets for the actuating fluid and opening in the plunger-cylinder, and two channels opening in the plunger-cylinder at points registering with the inlets and extending one to each end of the chamber in the valve-casing, of a valve in said chamber constructed to control the actuating fluid for the plunger-cylinder and to be reciprocated by alternate admission of the actuating fluid to the ends of the valve-chamber, and a plunger reciprocating in the plunger-cylinder and actuated by the actuating fluid distributed therein by said valve and constructed with a passage which alternately connects one inlet in the cylinder with one passage to the valve-chamber and which connects the passage to the rear end of said chamber at the forward end of the throw of the plunger, thereby neutralizing the back jar from the plunger striking the tool,substantially as set forth.

4. In a pneumatic tool, the combination with a barrel formed with a plunger-cylinder, a valve-casing having its chamber in axial alinement with and at the inner end of said barrel, an inlet channel for the actuating fluid and having inlets into the cylinder at points near the middle of the same, a channel leading from a port registering with the forward of said inlets to the rearend of the valvechamber and a channel leading from a port registering with the rear of said inlets to the forward end of the valve-chamber, of a distributing-valve in said chamber and con structed to distribute the actuating fluid to the ends of the plunger-cylinder and to be shifted by the alternate admission of the actuating fluid to the ends of the chamber, and a plunger in the cylinder and formed with a passage which alternately connects the inlets of said cylinder with the registering ports, substantially as set forth.

5. In a pneumatic tool, the combination with a barrel formed with a plunger-cylinder and a valve-casing arranged in axial alinement with and at the inner end of said barrel, of a plunger reciprocating in the barrel, a solid distributing-valve reciprocating in the valvecasing, and means for causing the valve to be thrown forward immediately following the forward throw of the plunger, thereby neutralizing the back jar from the plunger striking the tool, substantially as set forth.

6. In a pneumatic tool, the combination with a barrel formed with a plunger-cylinder and a valve-casing arranged in axial alinement with and at the inner end of said barrel, of a plunger reciprocating in the barrel and a solid distributing-valve reciprocating in the valve-casing and actuated by the actuating fluid, said plunger being constructed to control the actuating fluid to throw said valve in such manner that the forward throw of the plunger admits the actuating fluid to the valve to throw the latter forward, thereby neutralizing the back jar from the plunger striking the tool, substantially as set forth.

7. In a pneumatic tool, the combination with a barrel formed with a plunger-cylinder, and a valve-casing arranged in axial alinement with and at the inner end of said barrel, two inlets for the actuating fluid and opening in the plunger-cylinder, and two channels opening in the plunger-cylinder at points registering with the inlets and extending one to each end of the chamber in the valve-casing, of a solid valve in said chamber constructed to control the-actuating fluid for the plunger-cylinder and to be reciprocated by alternate admission of the actuating fluid to the ends of the valve-chamber, and a plunger reciprocating in the plunger-cylinder and actuated by the actuating fluid distributed therein by said valve and constructed with a passage which alternately connects one inlet in the cylinder with one passage to the valve-chamber and which connects the passage to the rear end of said chamber at the forward end of the throw of the plunger, thereby neutralizing the back jar from the plunger striking the tool, substantially as set forth.

8. In a pneumatic tool, the combination with a barrel formed with a plunger-cylinder, a valve-casing having its chamber in axial alinement with and at the inner end of said barrel, an inlet-channel for the actuating fluid and having inlets into the cylinder at points near the middle of the same, a channel leading from a port registering with the forward of said inlets to the rear end of the valve-chamber and a channel leading from a port registering with the rear of said inlets to the forward end of the valve-chamber,of a solid distributing-valve in said chamber and constructed to distribute the actuating fluid to the ends of the plunger-cylinder and to be shifted by the alternate admission of the ac.- tuating fluid to the ends of the chamber, and a plunger in the cylinder and formed with a passage which alternately connects the inlets of said cylinder with the registering ports, substantially as set forth.

9. In a pneumatic tool, the combination of a plunger-cylinder having a tool-socket in its outer end and an air-port at the inner end of said socket and provided with liveair ports and ports registering with the same, air-actuated valve mechanism for controlling the supply to the ends of the cylinder and having the valve-shifting air-channels communicating with the ports registering with the live-air ports in the cylinder, and a plunger in said cylinder and formed with a chan' nel which alternately connects the registering ports at the ends of the operative and back stroke and with a piston which closes all of said ports when the plunger arrives at the end of its unobstructed forward stroke, substantially as set forth.

10. In a pneumatic tool, the combination of a plungercylinder, air-actuated valve mechanism controlling the air supply and exhaust for the same, air-channels communicating with the actuating part of said valve mechanism, a plunger reciprocating in the cylinder and controlling said channels, and a tool inserted in the end of the plunger-cylinder to be acted upon by the plunger, said tool projecting into the cylinder so as to limit the throw of the plunger to cause the latter to control the air-channels for actuating the valve and so as to cause the plunger to pass beyond such limit to close said channels When the tool is removed, substantially as set forth. 4

11. In a pneumatic tool, the combination with the plunger, the tool acted upon by said plunger, and the distributing-valve controlling the movement of the plunger, of means controlled by said tool for stopping the operation of said valve when the tool is removed, substantially as set forth.

12. In a pneumatic tool, thecombination with the plunger, the tool acted upon by said plunger, and the distributing-valve controlling the movement of the plunger, of means controlled by said tool for stopping the operation of the valve when the tool is removed and for again causing the valve to resume its operation when the tool is again replaced in operative position, substantially as set forth.

13. In a pneumatic tool, the combination with the plunger, the valve controlling and controlled by the movement of said plunger, and the tool having its shank receiving the blow of the plunger at the end of its forward stroke and limiting such stroke, of means controlled by the position of the plunger for antomatically stopping the action of the valve when the tool is removed and the plunger passes beyond its normal limit, substantially as set forth.

14. In a pneumatic tool, the combination with the plunger, the valve controlling said plunger, and ports for admitting pressure to actuate said valve, of means controlled by the position of the plunger for controlling the pressure through said ports to the valve duringthe normal limits of the stroke of the plunger and for cutting off such pressure when s uch normal 1i mits are exceeded,substantially as set forth.

15. In a pneumatic tool, the combination of a plunger-cylinder, a plunger reciprocating in said cylinder, a valve-chamberformed with two live-air-inlet ports and two exhaustports and having two ports registering respectively with an inlet and an outlet port and communicating with the inner end of the plunger-cylinder and two ports registering respectively with the other inlet and exhaust ports and communicating with the outer end of the plunger-cylinder, and a valve reciprocating in the valve-chamber and formed with two passages which alternately connect a liveair-inlet port and its registering port and an exhaust-port and its registering port,substantially as set forth.

16. In a pneumatic tool, the combination of a plunger-cylinder formed with a port at its rear end and a longitudinal channel in its side and opening at the forward end of the cylinder, a valve-casing formed with a cylindrical valve-chamber having two exhaustports at its middle'and two live-air inlets, one at each side of said exhaust-ports, and formed with a channel in its side having ports into thechamloer respectively registering with the rear inlet-port and with the rear exhaust-port and communicating with the rear port of the cylinder and with a channel in its side havin g ports into-the chamber registering respectively with the forward inlet-port and with the forward exhaust-port and communicating with the channel leading to the forward end of the plunger-cylinder, and a valve in the chamber having three pistons forming two channels which' may alternately register with an inlet-port and an exhaust-port and having means for shifting it, substantially as set forth. 7

17. In a pneumatic tool, the combination of a barrel formed with a plunger-cylinder and with a channel 53 and a port 56 and with a channel 38 having ports 39 and 40 and with channels 60 and 61 having ports respectively registering with said former ports, a valvecasing. having a cylindrical valve-chamber and formed with exhaust-ports 51 and 52 and a live-air channel 37 connected to channel 38 and having inlet-ports 46 and i? and formed with a channel having ports 54 and 55 and communicating with channel 53 and formed with a channel having ports 58 and 59 and communicating with port 56 and with channels communicating with channels 60 and 61, a three-piston valve 42 in said chamber, and a two-piston plunger 12 in the plunger-cylinder, substantially as set forth.

18. In a pneumatic tool, the combination of a pistol-grip handle formed with an air-channel having an annular chamber at the end of the handle and with a lower chamber alined with said latter chamber, a cylindrical valvecasing having means for connecting the airsupply at one end and inserted through said chambers and formed with a partition and a port below said partition and a port above said partition and both communicating with said lower chamber and formed with a port communicating with the an nular chamber,a valve in the valve-casing having a piston sliding over the port above the partition and a piston permanently above the port in the annular chamber, a spring between the partition and the lower piston, and a pivoted latch upon the handle engaging the valve, substantially as set forth.

19. In a pneumatic tool, the combination of a pistol-grip handle, a valve-casing substantially transverse in the end of said handle, a supply-pipe enteringthe end of said casing, a valve in said casing and controlling the passage of air through said casing and handle, and a latch upon the inner side of the handle and engaging the valve to move the same, substantially as set forth.

20. In a pneumatic tool, the combination with a plunger-cylinder provided with air inlet and exhaust at its rear end and with a small duct at said end for permanent admission of live air, of a plunger reciprocating in said cylinder, and means for returning said plunger to and against the air-cushion provided through said permanent airsupply duct, substantially as set forth.

21. In a pneu matic tool, the combination of a distributing valve-chamber formed with a small permanently-open exhaust-port and a larger livc-air-inlet port at each end, means for alternately admit-ting live air to said latter ports, and a piston-\ 'alve reciprocatingin said chamber, substantially as set forth.

22. In a pneumatic tool, the combination of a plunger-cylinder having an inlet and exhaust port at each end and means for dis tributing the air to and from said ends and formed with a permanently-open live-air-inlet port of small area at the inner end of its bore, and a plunger reciprocating in said cylinder and cushioned at its back stroke by the air admitted through said lastmentioned port, substantially as set forth.

In testimony that I claim the foregoing to be my invention I have hereunto set my hand this 1st day of November, A. D. 1899.

CHARLES E. RICHARDS.

Witnesses:

WM. SECHER, K. F. WINDING.

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