US1557777A

US1557777A - Pneumatic tool

Info

Publication number: US1557777A
Application number: US374013A
Authority: US
Inventors: John R L Santos
Original assignee: GEORGE OLDHAM AND SON Co
Current assignee: GEORGE OLDHAM AND SON Co
Priority date: 1920-04-15
Filing date: 1920-04-15
Publication date: 1925-10-20
Anticipated expiration: 1942-10-20

Description

Patented Oct. 20, 1925.

byi

in is provided with a handle 20, in which; a

fluid-pressure supply passage 21, is formed, and a throttle-valve 22 is provided at the entrance to this passagewhich is controlled by alever 23, so that the operator may readiend of the box.

1y control the supply offluid pressure to the tool. d The handle has a sleeve part 24 which is screwed onto the upper endof the barrel in such manner as to provide or form an annular chamber 25, around the'interior of the sleeve, and exhaust ports 26, are provided in the sleeve which open outwardly to vent said chamber 25. Y I

The upper end of the barrel or cylinder is provided with a vertical annular recess so as toreceive a ring or disk 27 and to also receive the lower end of an annular or cylindrical valve-box 28,the box having its lower. endseated on the upper side of the disk or ring 27 and held down thereon by the clamping action of the handle on the upper As clearly shown in Fig. 5, of the drawing, the valve-box 28, has an upper central cylindrical chamber 29, and a lower cylindrical valve-chamber 30 which latter. is of a slightly-jlarger diameter than the said upper cham her. and forms an annular shoulder 31, around the base of the upper chamber 29 which -for1ns,.in this instance, a stop for the valve on its lip-stroke.

Immediately beneath the shoulder 31, the valve-box is provided with an annular groove 32, and this groove is always in open communication with a series of air-supply or intake-passages 33, which extend vertically in the wall of the valve-box and whose upper ends communicate with v an annular groove 71 in the handle which latter groove is always in communication with the fluid-pressure supply; passage-21,- in said handle as can be seen In Fig. 1, of the drawing.

It is thus to be understood that when the throttle-valve 22 is'operated to admit pres from the annular groove 32, and the intake passage 33. This longitudinal passage 34 is provided with a lift-supply port 35, which opens into the valve-chamber 30, and is further provided at its lower end withanother port 36, which also opens into said chamber both for purposes that will presently be' explained.

By again referring to Fig. 5, of the drawing it will be noted that the interior of the These passages 38,.are also clearly shown in Figs. 34 and 6 of the drawing.

.Below the lift-ports 37 the valve-box also has a plurality of ports 39, which extend laterally from the valve-chamber and'communicate with vertical passages 40 whose upper ends terminate at a lateral passage'41, which passages 40 extend entirely through the valve-box and open at the outer side of the latter, as shown by broken lines in Fig. 4 of the drawing.

It is important to. note that the valve-box has also a vertical passage 42, whose upper end turns laterally and inwardly and opens on the interior of the valve-chamber and further that at the upper end of this vertical passage there is a port 43, which establishes communication between the said passage 42, and at least one of the intake passages 33. As the passages 33, are ,alwayscharged with live air whenever the throttle valve 22 is open and the tool-is in operation it follows that under the same conditions the passage 42 will always be supplied with a diminished amount of air through the relatively small port 43.

By reference to Fig. 6 of the drawing wherein a bottom view of the valve-box is shown, it will be seen that the lift-passages 38, the vertical passages 40 and the live-air passages 42, all extend to the bottom ofthe box-wall.

On the interior of the box the valvechamber has an annular shoulder 44, which is located above the ports 37, and39 but be neath the lift-supply port 35 and that this shoulder 44, is produced by a slight enlarge ment of the internal diameter of the valvechamber all of which is for a purpose that will presently be explained.

By further reference to the bottom view of the box in Fig. 6, it will be noted that a blind hole or recess 45, to receive a dowel-pin (not shown) which is utilized to keep the several parts 15-28 and 27 in register, is provided at the lower edge of the 'wall,and further, that at one side a notch 46, is formed in the lower inner edge of the box wall as best illustrated in Fig. 5, all for purposes presently to be described.

f Beneath the valve-boxzrndj in the bottom ofthe aniiulerreeess in. the upper end of the cylinder; there is sea'ted a; ring or dish 27; si iown Figsfil fi and 8* the drawihisfring has" a centtali passage 457 an zrn nulm interior channel or gn'oovef48 iil said passage; 2; series of v-eitic'altliai-t passaig'es 49 enda plurality of} vertieal exhaust passages 59 the lower ends ofj which lattes extend inwardly and 'open into the channel or'groove 48 The upper side o'f the ri1-1g o-r disk is pro Vided with' an annular bead -51, which has exterior diameter that will enable-it-to enter-the lowene'nd of the valve bo zt when thelatter' is seated thereon, mdat onesid'e; this" head-isvertically 'notched as at 52', which notch registers with the notch; 46," in the flower edge; (iftheE Valve-box wail.

A vertical "'fiassa g-e '53, -is provided in" the ring or dish Whose; upper e r-1d communicates Withthe; space i by the notches ek6'52-. (which "in effect form "a port) '=and Whose lower end communicates with a; duct '54; thztt extendsklown in the/Wall of the cylinder 15, and, opens int o' qthe piston.

chamber 16;

live-air passage 42- irr'the valve b'ox has its lower end communioetingjwith a; veraticzt-l passage 55, inthe ring or ti'isk and the lower enct-oit this letter passegefcon-neots with 2r passage 56, in the 'cylinde'r which opens through the Wall, oif'theoy'linder into the piston-*chiimber 16. It i x'rii'lltherefore be seen thatthe-entmnce from} the piston-01mm; berto the? lower nc'i of pa's'sage iifi', lis' at a ,point below the annular exheust -gi oove-48 anti that" Whenever thet iow'e-i enbranee is 'uncoverei 'the plston; 1 7, "Whatevenpres sure fluictt'here may bei the piston ch ani piston ehamber whiie'the upp'er ends thereof connect with the 'pas'seges9', in the ring or "disk 27., and also with'the'pessages" 88in 'the valve-box.

By now referring to ,Fig. '9, ofthe drewing it will he noted that "the valve 5 8"',*i s of the cylindrical type and hzi'se 'cen'ftre1 passage '59, of a' diameter substahtially "equal to the diameter of the piston-numb r I6,

so that the piston 1'7, "may {reciprocate therethrou'gh. 0n" theexterior, the valve has'txvo annular 'eniergen ents and the former being'si-tuatedabove and spaced "h'oni the latter. 'HieeiilerQement-SO pro- Ewes an "uppe e i l er sh i fl r 6 t moves down.

beir' in -the suite-box 28g and when .p'lawd' I therein forms; an? upper: live air? ohambm fifi on the upper sidaeo of shoulder 62, and; ennule'r spaioer 67 around-ether waive betmeeh the sho'uiders: 631. anct 6.4;? anderso-ealhdt nular fliprthmnber beneath; the; shoulden 65; o f the waive: .I l

' en of 't'iiewalve: hasq nosition beneath the: shoulder"flyinzthe. Value-chem; 1.1": The upper cylindric end 69,.iQf :the vafl ve above the uppermost shoulder 621 thereon serves to: open andtixel'oseg thegennuler jgiooiresoi 18430 edniit tom cutf-ofl' l-ilwej. aim to 01 from the: upper end; of; the. piston )ch wmber through-"the central value passag'ee 59; and when this end of thewalwe ris the: dosed position; eel-in Figsg l band-11 1 l of zthe. draw inggv the" groove is; leuti ofi and, the cham; ber' 29; 1 in the upper: end; (iii the; uahiehox will be elo seai egitinst the. ieseapj'e of: pressure so as to. pistonon the-up-stnokea 'Ehe} iower cyiimdrie end 350, of the: value below; the lowve-nmost .1 shoulder L theneon also serves a 5 useful: :puzqgicise in that? it I coin tro1s' the'ese-ep'e or: pressurezrfrom' "thepistonehemher through the exhaust groove: 48 2+ i opening sa/ii" emhnust as"- .the piston moves upwnd closing. said! exhaust es'the piston reference to and oi the drawing it will be noted that e-.-smal1iI 'poErt -72 zcennects 3 the cylindrical chamber *29 goat the va lve' boxi witi-r-oneof'the l ive air passeges-3 3 so as to admit'live air :intoithe Tee-r end o'f the vejlveahox *tonthe-puwpose of starting the piston and valve forward in event theysjhouid both be inigeer-wavrd :position at the' heginning ofqanyf operation of the t-001.

" stroke: I that z is gieater than" its i own :lehgzth and that the inflentioniis especi a/l 'ly useful tools of this class;

- The; operation ofvt'he device is as tie Hens Presu niinglthe Waive. to Joe in thedown or forwzirdrposition shown in IF 1g; 10.. of :the

Edna-Wing end the throttle-Naive openiso that: uidfipnessurezoenzzpess through passage 21- M; Likil groove 7i1 ian iethnough supply @1 1 intake" 33, the incoming an pnd'clueerai cushion {for the will pass from passages 33 to annular groove 32 then up over the end 69 of the valve into the central valve-passage 59 thus acting upon the rear end of the piston 17 and driving the latter forward in the piston-chamber 16.

During this forward Stroke of the piston the air in the chamber 16, in front of the piston will be exhausted or driven out throughducts 57 to ports 39, which latter ports at this time will register with the annular space 73, around the valve between the

shoulders

60 and 61, which space also registers Withthe lateral branch 41 of the passage 40 so as to convey the exhaust through the box-wall to'the annular chamber 25 and from which chamber said exhaustescapes by port 26 to the atmosphere.

During this exhaust operation While the piston is making a forward stroke, the valve 58, is'held down by live air pressure acting upon the upper shoulder 62 and upon the valve end 69.

This holding-down live air pressure is derived from supply passage 33 by passage 43 to passage 42 and, when the piston 17 has moved down far enough to uncover the lower end of passage 56, live air-pressure from the pistonchamber 16, at the rear of the piston will enter said uncovered end of passage 56, and pass up

throughpassages

55 and 42 and will act in conjunction with the pressure derived from the port 43 on the upper shoulder 62 of the valve.

When the piston. has moved down far enough in the cylinder to uncover the lower end of ductt54 into the piston-chamber behind the forwardly-moving piston, live air pressure from said piston-chamber at the rear of the piston will enter said duct 54 and pass up topassage 53 and notches 46-'-52 to the so-called flip-chamber 68 where it will act upon the lower shoulder 65, 011 the exterior of the valve 58. As the area of the shoulder 65, is greater than the area of the upper shoulder 62, a force will be developed, because of the difference of these areas, that will be suflicient to push the valve 58, up,' the pressures on the opposite rim-ends of thevalve being balanced and the

shoulders

63 and 64 being subject or exposed to the atmosphere through the port 39.

It is thus to be noted that the. valve 58, will be moved upwardly by live air-pressure as the piston is making a forward stroke, and has been completely shifted to said up or rear position by thetime the piston has delivered its blow, and that said valve is held up by live air-pressure from port 36 expanding into annular chamber68, by rea- .son" of the fact that the expanded air cannot flow outwardly through the relatively larger passage 54 as fast as it is supplied. This may be best seen in Figs. 10 and 11.

When the valve 58 has moved upwardly or to its rear position, as shown in Fig. 11 of the drawing, the entrance ,of live air through annular'groove 32, will be'cut off by the end 69 of the valve extending up into the box-chamber 29 and live air cannot then pass over the end 69 of the valve and enter the rear end of the piston chamber 16, through the central valve passage 59.

The valve now being up. or in the rear cut-off position has uncovered the annular groove-48 at its lower end 70, and by unco-v ering said groove has connected the latter With the piston-chamber 16 and formed a communication from the piston-chamber through the ports 50 to the

passages

40 and 41 to the annular chamber 25'and ports 26 to the atmosphere so that the pressure at the rear of the piston in the piston-chamber can escape or exhaust.

At this time lift-supply port 35-, has been connected with lift port 37, by the annular space 73, on the exterior of the valve so that pressure will be supplied through

passages

38 and 49 to ducts 57 into the lower end of the piston-chamber 16,the annularprojection 61, on the valve having closed the exhaust ports 39. v

This lifting pressure through ducts 57,

will be less than the supply pressure in supply passage 21 of the handle due to the relative sizes of the ducts 57, and the passage 35.

The piston 17, 'now having pressure beneath its forward end and air exhausted from the cylinder on top of it, will move up, first uncovering, with its forward or bottom edge, the; lower end of passage 54 thus reducing and providing a relief for the pressure on the bottom shoulder 65 of the valve. After the piston uncovers the cylinder-end of duct 54 it eflects a covering of the entrance to passage 56, but at this time the central passage up through the valve, and practically a continuation of the pistonchamber, is still open to the atmosphere because groove 48, and ports 50 are uncovered. While the cylinder-end of passage 56 is covered by the up or rear-moving piston, live air from passage 43 to the upper end of passage 42 is building up a pressure in passage 42 and in the annular chamber 66 with which said passage 42 vcommunicates and this live air pressure acts upon the upper or rear shoulder 62, on the exterior of the valve 58, and becomes equal to the supply pressure in passages 33, at a time predetermined by the size of passage 43.

At this moment in the operation, the up per shoulder 62, of the valve is exposed to the pressure building up in annular chamber 66, while the pressures acting upon the

shoulders

63,64 and 65 are equalized, therefore when the live air-pressure in

passages

56, 55, 42 and in the annular chamber 66 has built up to a greater pressure than that which-is acting upon the shoulders 63-64 "2 In a pneumatic tool=- and of the valve the latter Will be pushed down or forward by such huil-t-up live air pressure trompa ssa'ge 43:4,

' When this forward inovement of the" is no pen d; my L w 011 t l PP rear" end" offzthe piston to, repeat the, operation."

Will thus be seen that the valve 58-, is; moved upwardly or rearivardl'y by live airactijng'jon the loiver or fprwardl shoulder 6-5 onthe valve such live air passing i-pm he hind: the piston from cylinder "16;": into duct- 54; and up {to the fii -chamber 68; and the-6- said valve is moved gomv'ardly ordownalsoby liveair which latter live air acts upon the rear or upper shoulder-- 62- and is derived from the passages 33-43 arid lQ; so that both movements of the valve. are efliected; by live air'pressure' "Having described my invention, what- I 'claimig 'j I a In 'a pneumatic tool; having a piston with stroke greater than its-own, length; a valve to control the admission and theIen tire exhaust of fluid pressure to andfrom opposite ends of the piston, said vallveh-a-v ing a, central' passage 'i-ntp whijch- -the piston enters, said valveal'so being provided with differential pness-ure areas;-'a;n'd {means for subjecting the; said difl eren-tial pressuige areas to live flu-id --pressuneldireeted alter nately from opposite-directions whereby -sai d valve' ivill be 'iilo-ved in both directions by live-fifuid pressure,

having awitlra' StrOke greater-th-an own length a 'valveca-sting,a val ve inysaid' casing and having diiferential areas to-c0ntr01the admission and the entire exhaust of fluidpressure to and from opposite ends of the piston sai df.differential areas ofithe valve being alternately subjected to live fluid pressure "directed freni o ppes in g sides Xvhereby -the valvemay he moved in" both directions by live fluid-press'u-re I alas pneumatic tool 'ha ai eyli nder with piston therein said v piston haviiiga stroke -'g'i eatenf1than its own "length, a valvecasing, a ya l ve ijn said-casing havingqdtfl'er- 'entlal pressure-surfaees'said valvecontnol- 1 ling theadmi'ssion and the entire exhaustl of fluid pressureto and? from oppositei nds of the piston, means" f orgsubj ectingene off said surfaces tofthe actiono-flive flili'Ch-PI-BSSHIJB While a relative reduction o-fpressure 0n another of said surfacesis provi'd 'ed, to move the valve in. one direction by live I pressure, and me ans "Eon subj eatingsaid other surface s a "7 a- "Witha cylinder l ravi n a valve-chamber at of the valve to live fluid pressure whereby to v fiu d'pre sm 1 4. pneumatic to el-lfiavii ga piston;- withxistr'oke greater; than its Owelength, a differential verve rto control "the admission" ofmotiv fluid to and" the entire exhaust ,ot-f said motive fluid from the -oppsite ends of the piston, said: valve being Inhjved in one di rectiozi by live motive"fluid*-ii1termittent1y acting on the larger pressure area' of valve flat one stroke ofthe pisterniand moved move ie valvein live;

ingthe opposite direct-fonby" live'inoti ve fluid intermittently acting upon the smaller pressure area offthe valveon other" stroke-"0t the piston.

5. apneurnatic toolhav-ing'a cylinder-g a piston therein with stroke-greater than its: QW'II' length; a val-ye to 'controlthe admie sion and the entire; exhaust'oiii motiye iflu'id to and fromthe opposite ends; of the pistong,

said valve being {located at" the; rearend {of the cylinder 'andin line ther ewitliandrneans ffbr intermittently directiinglivemotive-fluid alternately tojo p posing surfacesof the valve and move thesaine in directibns by live 61in aj'pneumatic toolthe, combination with a; cylinder, offa piston-in; said cy linder said". piston having" a stroke gre ater" than its own length; a val vechanl'bei at one end" of the cylinder and havingports and passages therein; for the-- assage oiii live fli -pressure to' and exhaust the cylinder and -a valfveinsaid-E chamberand m'eved automatioo pally "in Both directions 'hy alternately built up live air-pressure enaoppo si ng faces 1 of; the valve heliorethe completes: its strokesaid" valveajl eneeebntroll ing the entire exhaust fromtheoppesiteends ofi the cylihderr heumatic tool; the combination one end thereoii; of" a; piston said cylinder having a stroke gi eater than' own 'len gth 1. a valve in said chamber tocentrol the inlet and the entire exhailst of airg-ssaid valve both ends thereof: whereby vthe piston may move into said passage-pm its return stroke;

return-str cken m 1 -SmIn a; pneumatic-toe]; the combination with a cylinder, ofia piston irn saidicylinder having a;stn0l(e gneateiithanrits owne length;

iineans at the; end ofsthe: cylinder ton forming a wake-chamber; .saidi neans having; ipmgts passages: therein fora-the lnletw andre'xthatiis tconstaiittyiopen to: axliye iaiinsuppl-y,

-said{1ive-ain passage havingwone 'endopenihg having a" central passagewvhichis opein at a haustfofi fluid pressure, andl-haivingqa'pa'ssage I into the cylinder and also having an open ing into the valve-chamber, and a valve in said valve-chamber, said valve being moved in one direction by live air that is builtup in said live air-passage whilethe cylinder-end of said passage is closed by the piston and being moved in a reverse direction also by live air said valve alone controlling the entire exhaust from the opposite ends of the cylinder. 7 p i I 9. In a pneumatic tool, the combination with a cylinder, of a piston in said cylinder having astroke greater than its own length; avalve-bushing at one end of the cylinder and having a valve-chamber therein, said bushing having alive air passage that extends from the valve-chamber, communicates with the cylinder and is closable by thepistonon the return stroke of the latter; means for feeding live air to said passage while the latter is closed bythe piston, and a valve in said valve chamber movable in one direction by the live air from said passage and movable in a reverse direction also by live air said valve alone controlling the entire exhaust from the opposite ends of the cylinder.

10 In a pneumatic tool, the combination with a cy1inder,oir' a piston in said cylinder having a stroke greaterthan its own length; a valve-bushing at one endof the cylinder with a chamber thereinand having a live air-passage extending from said chamber and in communication with the cylinder, the cylinder-end of said passage' being closable by the piston; a valve in said bushingchamber having pressuresurfaces of unequal areas, said valve alone controlling the entire exhaust from the opposite ends of the cylinders; means for feeding live air to said live.

air-passage to act on the pressure surface of the valve having the smaller area to move the valve in one direction by live air, and

means for subjecting the larger pressure surface of the valve also to live air to move the valve in a reverse direction.

. 11. In a pneumatic tool having a cylinder with a piston therein which has a stroke greater than its own length, a valve bushing :at one end of the cylinder; a valve in said bushing with opposing pressure surfaces of unequal areas, said valve controlling the entire exhaust from both ends of the piston,

said cylinder and valve bushing having passages extending from the cylinder chamber to the said opposing pressure surfaces ofthe 'valve, whereby the piston will serve as a Valve for saidpassages.

. 12. In a pneumatic tool having a cylinder with a piston therein that has a stroke greater than its own length, a valve bushing, a valve in said bushing and having o-pposing pressure surfaces of unequal areas v 4 said bushing being provided with a passage that extends from the pressure side of one valve-surface and opens into the cylinder and a second passage that extends from the pressure side of the other valve-surface'and opens into the cylinder in a plane above the sage opening and may also close the upper passage-opening on its rear stroke.

13. In a pneumatic too-l the combination with a cylinder, of a piston in said cylinder said piston having a stroke greater than its own length; a valve bushing at one endof the cylinder; a fluid pressure supply a valve in said bushing controlling the entire exhaust of fluid pressure from opposite ends of the piston, said valvethaving opposing pressure-surfaces of unequal areas; a pas sage which is always open to the fluid-pressure supply, said passage havingan outlet adjacent one of the pressure-surfaces of the valve and another outlet into the cylinder, and a second passage from the cylinder beyond the outlet of the first-named passage, said second passage leadingto-and delivering fluid pressure adjacent to another of the valve pressure-surfaces whereby the latter or second passage may communicate with the cylinder at either the upper or lower sides of the piston while the first-named passage may be cut off fromthe cylinder by the piston to shift" the valve from one position to another. I I r Y 14:. In a pneumatic tool the combination with a cylinder, of a piston in said cylinder said piston having a stroke greater than its own length; a valve at one end of the cylinder and havingpressure surfaces of unequal area, said tool having a passage that extends from the valve-surface of the greater area to a point in the cylinder where it may be exposed either above orjbelow the piston according to the position of the latter in the cylinder and said tool having a second passage that extends from a Valve-surface of I the lesser areato a point in the cylinder nearer the valve than the first named'passage-opening said second passage being cylinder and provided with exhaust passages; a valve movable in the box to open and close said exhaust passages and to control the passage of motive fluid to the op posite ends'ot the cylinder,-said valveflhaving a plurality of pressure-surfaces; a pas- 1 said piston having a stroke greater than its own length; a valve-box at one end of'said sage that extends from one pressure-surface of the valve to a point in the cylinder where it may be exposed either above or below the piston according to the position of. the piston in the cylinder and a second passage exstroke toward the valve whereby to permit tending from another pressure-surface of live air-pressure to build up in said second the valve to a point in the cylinder between passage sufficiently to shift the valve. 10

the first-named passage-opening and the In t sti o y whereof, I afiiX my signav 5 said exhaust passages said second passage tllrebeing closable at the cylinder opening by the i piston as the latter nears the end of its JOHN R. L. SANTOS.