US1688020A - Pneumatic tool - Google Patents

Description

Oct. 16, 1928. v 1,688,020 JJR. L; SANTOS y,

PNEUMATIC TOOL Filed Dec. l5. "1922 Patented Oct. 16, 1928.

` UNITEDSTATES JOHN R. L. SANTOS, OF BALTIMORE, MARYLAND, ASSIGNOR, BY MESNE ASSIGNMENTS, I

g 1,688,020 PAT ENT orifices TO CHICAGO PNEUMATIC TOOL COMPANY, 0F NEW YORK, N. Y., A CORPORATION OF NEW JERSEY.

' PNEUMATIC '.rooL.v

Application filed December` 15, 1972.2. Serial No. 607,183

This invention relates to improvements in between the two cylinder-members as and for 4 pneumatically operated tools and in its present form has features that especially adapt it for use ina tool known as a jam-i'iveter.

An object of the invention is to provide an improved tool wherein the motive fluid utilized for operating' the piston or plunger isA directions by live pressure.`

Another object is to provide animproved controlled by. a valve that is moved in both `tool structure in which the valve which controls the motive iluid that actuates the plunge Ver or piston may be moved in one direction by a const-ant live pressure and be moved in a reverse direction by a continuous but variable live pressure. o

A still further object of the invention is to provide an improved tool that embodies e.specially desirable features when the tool is to be used as a .so-called ain-riveter. o

The presentinvention embodiesthe novel features forming the subject of a companion application Serial No. 607,184, filed Dec. 15, 1922 for patent fora percussive tool which application I aniexecutinp; simultaneously.

herewith but the present application discloses astruct-ure wliich'is zin-enlargement on the vdevice of my said companion application.

llith theseand other objects in View, the invention is illustrated inthe accompanying drawings, wherein,-

Fig'. 1 shows the improved tool in'vertical longitudinal section.

2 illustrates the locking means between the lower cylinder member and the cap.

l Fig. 3 shows a cross-sectional detail through the tooL-'tlie section being taken on the line 3 3 ofFig. 1. f l

Fig. ,1s-illustrates the detached valve on an enlarged. scale.Y v y Fig. 5 shows in a `diagrammatic way and on an enlargedscale some of the ports land passages utilized in the tool, for illustrative purposes only, and

Fig. 6 illustrates a similar View with the parts'in areverse positiomalso forillustrative purposes only.

Referring to the drawings, the numeral 1, kdesignates a plunger or piston, 2', a lower cylinder-niember, 3, an upper cylinder-member, which two cylinder-members are separated bv an interposed valve-boi; orbushing 4, in which a 4'valve 5 is retained so as to 'have lonmovement la 'the boniorbusliing' gift upper member 3,.the box 4 and has a Vscrewthreaded engagement-with the upper endof the Icylinder-nfiember 2. The cap 6 therefore is rigidly lattached Vto the lower cylindermember and contains the upper member and the valve-box.

The lower cylinder-member 2 carries the .working'tool 7 atits extremelower end and "under the piston 1, where the latter may strike the inner end of the tool on each of its forward strokes.

A tubularcasing 8 telescopically receives the cylindrical cap and its contained parts vand also encircles the lower cylinder-,mem-

ber 2. Y

This casing is, in the present instance, closed at its upper end by means of a disk or plate 9.

To effectually lock'thecylindrical cap 6 and the lower cylinder-member V2 against independent rotation or separation in the tubular casing, I provide 'a split lockingring 10, as shown in Fig. 2 of the drawing, whose ends engage notches on the cap and member 2' and therebyv prevent rotation. of the one with respect to the other.

- 'The tubular casing 8 has an interior shape at its lower `end which coacts with the exter- -nally reduced lower end of the cylinder-member 2 so as to form a lower` annular exhaust chamber I2, while ports 11, one ofy which is 5 shown in Fig. 1, are provided in the casing wall to serve as exhausts from said chamber 12 to the atmosphere. V

The upper end orfjthe tubular casing 8 is Yprovided with an air-supplylp'ort 13 while a passage 14'leads downwardly fromsaidportV Y and communicates with an 'annularchamber 16 which is Vformed between the exterior of the -cap 6 and the interior of the casing 8.v

Thetwo chambers 12 and 16 are clearly cut off vfrom each other by the enlargement in thelower cylinder-member 2 and the cupleather or packing 32. thereat.

A passage 15 'extends from the supply port 13 and opensirito theV upper casing chamber 33 above the top of the cap 6y for a that. 'will' presently be. explained.

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The upper end of the cap 6 is provided with a circumferential cup-leather or packing 31 whereby to prevent leakage or' air from the upper side of the cap 6 down into the annular chamber 16.

From the foregoing explanation ity will be seen that the casing 8 for all practical purposes has the form and the operation of a cylinder, while all he parts including the cylinder members 2. 3; the valve-box 4 and the cap 6 being rigidly connected, have the form and operation of a plunger. y

Obviously, il' fluid pressure be admitted through passage 15 into the casing-chamber 33, that pressure will act upon the top ot cap '6 and push the latter down in the casing and by sov doing` will project the lower end of cyl-` inder-member 2 more or less from the end of thejcasing.

The cylindrical wall et the cap 6 is provided with a plurality o'lI ports 17 which establish communication between the annular lis in constant communication with the annular channel 1,9 and the ports 17. This annular groove 18, is so positioned that it may be controlled by the valve 5 and at times exposed to the interior oli the cylinder-members and valve so as to admit pressure into the latter as `and for a purpose that will presently be explained.

A vertical channel 20 extends longitudinally in the lower cylinder-member 2 and also in thevalve-box 4, and the lower end of this channel opens inwardly through the wall of the lower cylincer member 2 and communi- Cates with-the lower cylinder-chamber 21, beneath the piston or plunger 1, when the latter is up. The upper end of this vertical channel 2O communicates'with an annular channel 22 that is formed around the interior of the valve-box 4 two walls of which` channel are produced by an overhanging shoulder 23 and an annular port-ion 25 of the movable valve. It is therefore to be understood that the upper end of channel 20 opens under the valve sh oulder 23 at which point the valve has the great-i est diameter as clearly shown in Fig. 4 of the drawing. i

By 'reference to Fig. 1 oi the drawing it will be noted that a small port 36, extends through the valve-box 4 from the annular channel 19 to the upper end of the vertical channel 2O and as this small port is always in communication with the channel 19, ports17 and annular chamber 16,' a small jet 'of air under pressure will constantly be supplied to said channel 20 which will build up a pressure therein vwhen the piston 1 closes the lower end of the channel 20, but that said constantly-supplied air will escape from channel 2O into the lower cylinder-chamber 21, and pass out through ports 30 when the piston is up' 23, and by reference to Figs. .15 and 6 of the drawings it will be seen that this upper shoulder 24 dt the valve is positoned so that it may be constantly exposed to the pressure fluid admitted from the chamber 16 tirou'gh the groove 18.

The lower end of the valvehas an annular portion26 of the same diameter as the annular vportion 25, and between said twoannular portions rsaid valve has an annular groove 27 which serves a useful purpose aswill presently be explained.

A lift-channel 28, extends longitudinally in the wall. ot the lower cylinder-member 2 and also up into tl e valve-box 4 and the upper end of this lift-channel connects with a valve-box port 29 which latter registers with the annular groove 27 oi the valve. The lower end of lift-channel 28, terminates in the chamber-'21 oii'cylinder-member 2 adjacent to the working tool 7 and beneath the piston 1 as clearly shown in Figs. 1 and 6 of the drawings.y

Ports 30 are provided in the lower cylinder-member which connect the cylinderchamber 21 with the annular exhaust-chamber 12 so that pressure under the piston and from channelV 2O may escape to the atmosphere when the piston is up. It is to be noted that the upper cylindermember 3, thevalve 5 and the upper end oi the cylinder-member 2 are all open centrallyand forman upper piston-chamber 35 so that the piston may travel through the valve from one cylinder member to the other. AThe cap 6 extends over and forms the upper end of the upper cylinder chamber.

Longitudinal cylinder passages 37 are provied which have the lower endsl in yconstant communication with the exhaust by way 'of ports 30 (see the diagrammatic view of Fig. 6) and the upper ends of these passages connect'with ports 38 in the valve-box4, sothat said valve-box ports are always open to the exhaust by way of ports 30, annula-r'chamber and port 11.

In the valve-box there are passages 41 which extend from upper valve-box ports42,

ldown to and connect with the upper ends of the cylinder passages 87 and ais the box-ports 42, open at the upper side of the large upper valve shoulder 44, these ports and passages 41 and 37, provide ak constant'relie to vent pressure from valve shoulder 44 tothe atmosphere. i

The valve-box 4 is'provided'with a port los) 40 which opens at the side of the valve and `a port 39, extends from, this port 40 up through the boX and into the lower' part of upper cylinder-element 3 where it communicates with the annular groove 18, which latter is constantlj7 supplied or charged with live fluid pressure.-

The annular channel 22 around the interior of the valve-.box 4 is supplied withluid pressure by apassage 13 from annular chamber O perd/ion.

Presuming a. suitable throttle valve to be screwed into the supplylport nipple l13 and that said throttle is designedto control the admission oi' iiuid pressure to passages 15 and 14. l

F luid pressure entering chamber 33 through passage 15 will act on the end of cap 6 which serves as a plunger-head. At this moment the tool will be in place against the work and may be sustained or braced at the casing end 9 so that movement of the entire tool in a rear direction may be prevented.

Aspressure is admitted into chamber33 that pressure will act upon thehead-end of cap 6 and move the same 'forward in the casing 8. rlhis forward movement of the cap in the casing will cause a like movement of the two cylinder- members 2 and 3 and the interposed valve-box the forward end of cylinder-member 2, thus being projected from i t-he casing until the working tool 7- seats against the work to be acted upon. This fore ward-acting pressure in chamber 33 is maintained to keep the cylinder-members pressed forward and also to advance the same as the work progresses.

The Huid-pressure admitted through pas-k the central passage thereof to the upper side of the piston 1 which latterv will be driven down. At this time, as piston 1 approaches the end ot its orwardstroke it will cover the lower end of channel 2O so that the 'fluid pres'- sure entering the upper endof this channel 20 by port 36, will build up a.V pressure in annular groove 22 beneath the large shoulder 23 of the valve and lift the latter, even against the pressure on the smaller shoulder y 24 or' the valve, thereby cutting ott the supply ci? iuid pressure into upper c amber and at the Sametime uncovering valve-box port .38, so as lto permit the pressure on the upper side of piston 1 to vent from chamber 35 and pass out through passages 37 and ports 30 into the .annular exhaust-chamber 12 from which it will exhaust to the atmosphere through casing port 11. y

l/Vhen the pressure above the piston is thus relieved and the kvalve is up, the annular channel 27 of the valve forms aconnection betrom the constant supply in annular channel- 18,l around the upper end of the valve, will kpass down passage 39 to port 40; then into annular valve-groove 27; then out through port 29 to .and down through channel 28 to tween port 40 andport 29 so that live air the lower end of lower cylinder-member 2 into chamber2lbeneath the piston 1 where Y it may act upon the piston and drive the latter up.

As the piston moves up its bottom or low.- er end will uncover the entrance from chamber 21 to channel 20 so that the fluid pressure (air) can escape from said channel into the `cylinder and from the latter by the ports 30 to the annular chamber 12 and thence to they n atmospheric by exhaust port l1.

This venting from channel 20, reduces the pressure from beneath the shoulder'23 of the valve so that the pressure'on the valveshoulder 24 (which is constant) can move the valve down as` the piston nears the upper end of its stroke and thereby admit pressureon top of the piston for driving the piston down again. v v

Annular channel 27 inthe valve makes a connection between ports 29 and 38 of .the valve-box and thereby exhausts air from beneath the piston by passages 28, passage 38 to port 30 and thence to atmosphere.

The port 43 in the valve-boxis uncovered sition and at this time admits air from annular chamber 19 to channel 22 so as to augment the pressure from port 36 to act on thevalve shoulder 23 and thereby keep the valve up the desired length of time after the bottom ot' the piston has uncovered ports 20 and 30.

Having described my invention, what I claim isf i n 1. In a percussive tool, a cylinder, a plung` er, a valve to control the admission oit motive Huid to opposite sides ofthe plunger said valve having an area subjectto a substantially constant pressure'and a larger opposed area subject to acontinuous variable pressure, a casing aroundthecylinder and forming an annular pressure supply chamber around one portion of the cylinder and said casing forming an annular exhaust chamber around another portion of the cylinder, exhaust connections to and from said latter chamber, supply connectonsto the Erst-named chamber, and means for moving the cylinderplongtudinally of the casing. Y

- by the valve when the latter is in the up posure for said cylinder having an iinpei'forate end, a pistoiireeiprocable Within said cylinder, an automatic distributing valve for oontrolling the admission of motive fluid to opposite sides of said piston to elifeetinovenient of the latter, a casing around said Cylinder and enclosing said closure end, said easing cooperating With said cylinder and' closure to provide spaced annular Chambers around said cylinder, one of said annular chambers'. being continuously open toexhaust, means for conducting motive fluid to said other annular chamber, ineans for moving said CylinderV Within said easing said easing having ports and passages eoinn'iunieating with said annular chambers in all positions of said cylinder Within said easing.

In testimony whereof I aliix iny signature.

JOHN It. L. SANTOS.

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