US1881886A - Valve construction for pneumatic tools - Google Patents

Description

oct. 11, 1932.` R. A NORUNG 1,881,886

VALVE CONSTRUCTION FOR PNEUMATIC TOOLS Filed April 5, 1931 3 *Sheets-Sheet 1 VALVE CONSTRUCTION FORy PNEUMATIC TOOLS Filed April 6, 1931 3 Sheets-Sheet 2 ATTORNEYS 3 Sheets-Sheet 3 Oct. 11, 1932. R. A. NoRLlNG VALVE CONSTRUCTION FOR PNEUMATIG TOOLS FiledApril 6, 1931 Patented Oct. 1v1, 1932 anINHoLD A. NORLING, or Annone, .irnmorsnssrenon ro lInnern'upenn rNEUiv'rA'rro TOOL CO., OF CHICAGO!" ILLINOIS,

A ooRro'Refrrou @DELAWARE VALVE CONSTRUCTION Foa PNEUMATVIC Toons Application led April 6,

This invention relates to a plate valveconstruction for pneumatic hammers and' like tools. V1 Y Plate valve devices, as heretofore employed, have been so designed and construct- Y ed as to require a lapped or ground lit vb etween the peripheral edge ofthe `valve member and the chamber in which it has lateral shifting movement to prevent leakage of live air past the valve member inthe Yoperation ofk the tool. lVith the valve member shifting repeatedly in the operation of the tool, the rubbing action of the peripheral edge 'or surface Vof the'valve member against, the adjacent surface ofthe valve chamber soon wears the valve member and permits leakageV which causes the tool to lose power in proportionto the amount of the wear. To rectify Vthe leakage, either the block or the valve member, or both, have to be replaced, because with' a plate type of valve, there isno way of taking up the wear. If one of the parts only is replaced, the standard is changed. For instance, if the valve member is to be changed, an oversize valve member need` be used and the block either lapped or Agroundin order to obtain the proper contact relation between the edge of the valve member and the block. This requires the services of a skilled mechanic, which services are not always? available by the user of the tool. The lapped or ground joint between the edgewo'fth'eA valve member and the block is required because the ports controlled by the valve member are at or suflicientlyclose tothe edge or periphery of the valve member t0 leak around the edge of the valve member when such edge becomes worn. Furthermore, the valvemember, 'as heretofore employed, is in the formof a relatively thin plate or disc so as to be light `,in weight for ease and rapidity of shifting and being thin does not have suflicient bodyto stand a great deal of wear at its peripheral edge where it must vretain Contact withfthe 1 block to prevent the leakage referred to.

In accordance with my invention, loifset the ports in theblock as controlled by the 1valve member well within theperipheraledge of the valve member andthus do notrequire such vedge to have a lapped fit with the block,

l1931..V seriaim. 528,044.

to prevent leakage as heretofore. (linse-i` quently, `any wear at the peripheral edge of the valve member, either 'on the latter or on the block .will not permit leakage or cause the tool to lose power. Moreover,'there is no. appreciable amount of friction developed between the edge of thel valve member and the `block to retard the rapid shifting thereof, s and lasa result the tool operates with greater speed. y

In accordancewith my invention, theop- Vposite side `surfaces or faces of the valve member and the opposed surfaces or faces of the block, when in Contact, are relied upon to prevent leakage pasty the valve .memb'errin- Y stead of the edge of the valve member `as heretofore. Consequently, any wear or pitting of such surfaces can be readilyeliminated byua grinding or lapping operation.

vlNith such surfaces made perfectly straightvl.

or flat, lapping of the same can `be donein a few minutes? time by merely removing-the valve parts from the tool and rubbingthem on a surface plate with a suitablev vlappir'ig compound.' This will restore the valveY de- .vice to proper working order without being required to replace either partl or elian'ge or alter their original outside diameters- A further object of my invention is to' so arrange the ports in the block, as controlled yby the valve member, adjacent the periph- -eral edgethereof, sothat the central or intermediate portions ofthe valvemeinber on the opposite sidesfthereof will not 'close such ports andmay thus be employed as the "pressure areas for shifting the valve. These areas are preferably formed by' recesses or ,cavities in the opposite sides of the valve 'foo member so as to'be open to live'air pressure when the valve member isin contactgwith l 'to -the block. lThese recesses or cavities *are The only accuracy required is that the faces of the block and the valve member be straight, that is, flat. Moreover, the hammer or tool is shorter and consequently lighter in weight.

The invention consists further in the matters hereinafter described and claimed.

In the accompanying drawings Fig. 1 is a longitudinal sectional view through a pneumatic hammer equipped with a valve device constructed in accordance with my invention;

Figs. 2, 3, 4, 5, 6, 7 Vand 8 are transverse sectional views taken on lines 2-2, 3 3, 4 4, 5 5, 6 6, 7 7, and 8 8, respectively,

Vof. Fig. .1; kand rigs. 9, io, n, and 1e are ingauainai sectional views taken onv lines 9 9, 10-10,

11 11, and v12 12, respectively, of Fig. 4. In the drawings, 1 indicates the barrel of the tool forming a cylinder, in which is reciprocatedla piston 2 for delivering blows to the chisel or other working element 3 at the forward end of the barrel.` The handle 4 at the'opposite end of the barrel is provided with a tubular extension 5g whichifits over the inner end of the barrel and hasV screwv threaded connection therewith nas shown. .Compressed air, the motive fluid employedafor operating the tool, is supplied to thebarrelfor reciprocating the piston 2 .therein through a passage 6 in the handle 4,

the latter having a manually operable valve 7 for controllingk the How of air through said passage as in tools of the character herein shown. i Y

The valve device of my invention com- Vprises a'pair of upper and lower blocks 8, 9,

Yber 11 within theV inner circumference of the-ring. A valve member 12 in the form.

Vof afsubstantially flat circular plate is lo- Lcated in the chamber 11 and has lateral shifting-,movement therein to control the admission vof live air to the opposite ends of the barrel. The blocks 8, 9 are provided with a number of radial recesses kmilled or formed in their outer faces. The recesses in the block 8 are shown in Figs. 2 and 12, and

lare designated by 13, 13, and 14, respective- .,ly'. The recesses in the block 9 are shown in Figs. 4 and 11, and are designated by 15, 15

i and-16, respectively.r With the recesses in theblocksopening through the youter faces of the same, I provide cover plates 17, 18

therefor, yas shown in Figs. 1, 11, and 12.

together YV-in Ytheir superimposed relation byV is situated against the inner end of the barrel 1, and .is held in place by the handle 4 through an annular shoulder 2O therein bearing against the upper cover plate 17 as shown. The openings in the upper cover plate- 17 for the dowel pins 19 are counter-sunk on their 4. g

inner sides to form seats for the upper` ends of the pins. .The opposite or lower ends of the pins lit in the upper ends of the longitudinal passages ,21, 21, in the barrel 1, said passages being madelarge enough at their upper ends to receive the pins, and to provide. shoulders for the lower ends lof the pins to hold them in place as shown in Fig. 1. y The dowel pins fit loosely in the holes provided therefor in the valve device, so thattlie' parts fi; may be separatelyV removed when the handle .4 is unscrewed from' the barrel. When the parts areY in the tool, the handle on being screwed onto-the barrel clamps the valve device `tightly against the same.

blocks by rivets 192.1921, as shown in Fig. 10'.

The cover 5,3' `plates 17, 18, may be fixed to their respective' As shown in Fig. 9, the radial recesses 14, 16 in the upper and lower-blocks 8, 9. are connected at the opposite V'sides' of the 'f valve device through ports or passages 22, 22, in thering v10. Block 8 is provided with a center port 23, which connects passage 14 with -the valve chamber 11. Block 9 has a similar centralk port 24 connectingr recess 16 with valve chamber 11. Upper cover plate 17 is pro-videdwith a center port 25 Vconnecting recess 14 with a chamber 26 formedin the portion ofthe handle inside of the clamping shoulder 20.. Chamber 26 connectsdirectly withk the `nmain inlet passage 6 in thehandle, Y

as shown in Fig. 9. j v

. As shown in Figs. 2 and 4, blocks 8 and'v 9 each have a single recess 14, 16, respectively, which recess extends diametrically acrossits block and has portions on opposite sides of its associated c-enter port 23, 24, Vas thecase may be.` 15 in thel respectiveA blocks are'muchl shorter than fthe associated recesses 14 and 16 and are arranged in Asets or groups on opposite sides thereof. In the form of .deviceshowm there are four of these short recesses in each barrel at-various pointsabout the circumference thereof.

The inner end of each recess 13, as shown in` Figs. 2 and 12, isV over the'valve chamber 11,'wellinside1of the Vinner circumference of the ring 10and is connected withsaid chamberby one or more'ports 27, 27, extending through the portion of the block 8 between the chamber and the recess 13. The innerV end Vof The otherradial vrecesses 13 and` each recess 15, as shown in Figs. 4 and 11, is similarly disposed with respect to the chamber 11 and is connected therewith by a port 28 in the portion of the block 9 between Athe chamber and the recess 15. The outer end of each recess 15 is connected t0 a longitudinal passage 29 in the barrel 1 by a port 30 in the lower cover plate 18 as shown in Fig. 11. Passages 29 connect through ports 31, 3l with the forward end of the barrel, that is, the cylinder as provided by the barrel for the piston 2. The forward end of the piston is tapered so as not to cover ports 31 when the piston is at the forward end of the barrel and in contact with the working tool 3. The outer end of each recess 13 is connected with the inner end of the cylinder through p'orts 32, 33, 34 and 35 in the ring 10, lower block 9, cover plate 18, and barrel 1, respectively, as shown in Fig. 12

The opposite side faces of the valve member 12 are centrally recessed, a-s at 36, 37, so that when the valve member is against the innersurface of either block 8 yor 9, the center ports 23, 24 in the blocks will not be closed ,by the valve member. The marginal portion of the valve member will, however, alternately open and close the ports 27 28, in thel `lateral shifting of the valve'member into and out of contact with the blocks. Y

The operation of the tool is asfollows: Opening valve 7 in handle 4, admits compressed air from the supply to chamber 26 through-passage 6. Fromrchamber 26, the compressed air enters recess 14 in the upper block 8 through center port 25 and into valve chamber 11 on the top side of the valve member 12 through center port 33. Fromrecess 14, the compressed air iows into recess 16 in the lower block 9 through ports 22 and enters chamber 11 on the lower side of the valve member 12 through the center port 24. By this arrangement, there isA a constant pressure at all times on two sides of the valve member 12. In starting the operation of the tool, the piston 2 being at the outer end of the barrel 1 and the valve member 12 resting on the lower block 9, as shown in Fig. 1, the full pressure is in the cavity 37 in the under side of the valve member. Ports 27, 27 in the upper block 8 are uncovered by the valve member 12, as shown in Fig. '12, and are open to the exhaust through ports 38, 38, in the handle section 5 of the tool by way of ports 32, 33, 34, 35, passages 21 and ports 39, 40 thereof, as shown in Fig. 1. These ports being considerably larger in area than the center port 23 in the upper block 8, the pressure on the upper side ofthe valve member 12 is reduced, allowing the valve member 12 to shift upward against the upper block 8 to close the exhaust through ports 27, 27

as shown in Fig. 11. This opens ports 28 in the lower block 9 and allows live air to flow to the forward end of. the barrel (to drivethezpiston rearward) throughreeesses l5, ports 30, passages 29, and, ports 31,7 asv shown in Fig. 11;.Asfsoonas thelpiston in its 'rearward movement uncovers ports 41,

" the portion -offv theV cylinder in: they barrel` forward offthe: piston .is .open totheatmos- Lpherej through passages 42, :42 in? the? barrel, which 1 passages .by ports` 43,43, connectfwith the space about-the :valve blocks as served by. the main exhaustports 38'.y The pressure isr-thus'reduced {inthe-.under sideofithe valve member 12. :Ports .andfpassages.28, 15,30, 29and131', being considerably vlarger'. in area than ,center port 24, andthe full pressure being` on topof. the val-ve member'12 inthe i cavity'36, :the valvemember will` shifttowardy the lower :block Q-te close .ports 28 therein.

Bythistime thepistonr2swillfhave reached "the, inner end of the cylinder, as shown in Fig. v12, andithe :portsi 27, 27, being open, will admitslive air'to the rear'endofithe cylinder to drive-.thepiston forward. Asa soon4 asthe piston inits forward'movement: uncovers exlhaust'portsl44,lt-he pressure en-theftopsof the valve rmember 12A will be` reduced andV the f fullpressure being on the yunder' sideo'f `the valve, kthe latter will againshift :upward or rearward to close ports 27 and the inlet ports at thel frontend of the cylinder will be again opened to drive they piston rearward to re' peat the cycle of operations. It will be obr thus the peripheral edge of the valve memberneed not lit against the inner circumference of the ring 10 to prevent leakage around the valve member, as heretofore. Any ,wear at the peripheral edge of the valve member will not cause the tool to lose power, as the flati` l@ side surfaces of the valve member where they contact with the opposed fiat surfaces of the blocks about the ports 27, 28, are

to prevent leakage past the valve. VAs these sufaces may be lapped', lany wear or pitting employed leeY y thereof may be removed without replacing any ofthe parts. The valve member 12 not requiring a tight iit inthe chamber 11 will have a faster movement, thereby increasing vthe speed of the tool. The recesses or cavities 36, 37 in the opposite sides of the valve member the valve.

An exhaust delector is arranged on the,y

exhaust exterior of the tool over the main ports 38. v

The details of construction and arrangement of parts `shown and described may be variously changed and modified withoutA de- Parting from they Spiritand scope of my in; VL?" provide pressure areas for shifting VventiomeXoe-pt as pointed out inthe append- .ed claim'.

,I claimas :ny-invention: Q f y In a `fluid actuated hammenthe Vcombination vof a cylinder having a free exhaust; a hammer piston in the cylinder controlling said exhaust, a valve device forsaid cylinder f for controlling the admission yof pressure fluid Ytothe vopposite ends-'0f the same, saidfvalve devicehaving fa valve chamber', inlet and ,outlet ports opening into the rchamber on opposite sides thereof, there being a single. centrally, disposed .outlet ports on each and a plate valve member laterally shiftable in said chamber for. alternately ,opening and inlet port and a plurality of side of the chamber,

closing vsaid outlet ports, said valve memvloer liaving'central recesses on opposite sides opposite the inlet -ports and surrounding the same to prevent'closing of the inlet ports by the valve,` member and to provide enlarged pressure .areas forshifting the'valve member, said outlet ports being vof the recesses and vlocated between the same v 2 andthe periphery of theV valve member..

disposed exterior vntestirnony whereof I aixmy Signature.

Y REINHOLD A. NORLINGEV Cil CJ l

regrese

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