US1320228A - Casting-machine. - Google Patents

Description

w. G; E. HARvEY CASTING MAcHmE.

, APPLICATlON FILED NOV.29,19 18.

Patented om. 2S, um.

/g`;sHEETs-SHEET x.

5 mmm/w01:

in Casting-Machines,

UNITED STATv rS PATENT FFICE.

WALTER'G. E'. HARVEY, 0F NORTH BERGEN, NEW JERSEY.'

CASTING-MACHINE.

To all whom t may concern.'

Be it known that I, WALTER G. E. HAR- VEY, a citizen of thel United States, and residing,r at North Bergen, in the county of Bergen and State of New Jersey, have invented certain new and uset'ul Improvements of which the following; is a; specification, such as will enable those skilled in the art to which it apperfollowing' specification, .panying drawing' forms a part, in which the separate parts of m v improvement are desigtains to make and use the same. This invention relates to metal casting machines and particularly to machines of this class known as coinpressedair casting machines77 designed dentists in the casting of inlays, saddles, full and partial plates, -and bridges, and

said machine may also he used by jewelersV and others in the cast-ing ot' smallor comiaratively small metallic parts; and the object ot' this invention is to lprovide a machine of the class specified with whichboth coal oasand nitrous oxid may liensed in meltingthe metal employed; a further object being to provide a common means whereby y an air-tight joint or connection may be produced with each of the different size rings employed in machines of this class; anstill further object being to provide automatic means for shutting off the supply of coal gas or nitrous oXid and for opening the com'- pressed air supply in the operation ot' the inachinei and with these and other objects in View the. invention consists in a inachineof the class and for the purpose specified which is simple in construction and voperation Aand eilicient in use.

The invention .is Jfully disclosed in the ot which the accom nated by suitable reference characters 1n each of the views. and in which Figure 1 improved y thereof ina normal position-and illustrating one method of its operation; Fig'. 2 a plan view ofthe construction as sl'iownin Fig 1;

Fic. 3 a partial section on the line 2 2 of F ig. 2 but showingV parts in a position indicated in dotted lines in Fig. 4;

Fig. 4 a front View of the machine as shown in Figs. 1 and 2 and indicating parts thereof in a different position in dottecli lines;

" Figs. 5, 6 and 7 are views similar to Fig.

to be used especially by' is a sectional side view ofiny. machine indicatingA the 'parts' Specification of Letters Patent. Patented 0013. 28, 1919. I. vApplication ledlNovember 29, 1918. Serial No. 264,495. l i

1 but showing only a part of the conStruc-, tion and illustrating modified uses of the machine Fig. 8 a View similar to Fig. 4 but show 60 ingonly a part of the construction and illustrating a modification; and,

Fig. 9 a detail sectional view of a Crucible form which I employ in the method of oper'- ation as illustrated in Figs. 1 to 4 inclusive. 65

In the practice of my invention. I provide a frame 10 which consists, in the form of construction shown, of a .base portion 11 at one end of which is an upright gooseneck portion 12 having a hollow cylindrical 70 head portion 13. whichranges vertically. The base 11 "of the frame is nrovided with a raised annular flange 14, the center ot which is provided with an aperture 15 which is in common v alinement'with the center of 75 A plunger 18 is mounted in the head 13;/80

and n'iovable vertically by means ot a lever 19- placed in a vertical recess 20 jin the top of the `roosefneclr portion 12 and pivoted to said gooseneck as shown at 21. The pivot'ed end of the lever 19 ,is provided with a 85 circular head QQ, the periphery of which is provided withl a yplurality otteeth or projections 23. which mesh with arack- Q5; counters'unk and secured in the inner face of the plunger 18 by screws 25. The front 90 end of the lever 19 is tapered as shown at 26 and a handpiece. 27 is secured thereto by a cylindrical nnt'QS-mounted on the end of the lever 19.

- A p aWl or ,clutch member 29 is secured to 95 the gooseneck 12 oi? the frame by means of' a casing 30 in whichsaid pawl is moved vertically b v a spring. 31, and a sleeve 32 1S]- mounted over -the casing and movable longi.;

tudinally thereof, and connected with the pawl 29 by a screw 33 which is movable in an elongated slot 34. and with this construction the lever 19 will be locked against movement in the dire tion of the arrow of Fig. 1'k by the pavvl\29v unless said pawl 105 is moved downwardly by grasping the sleeve 32 as will be readily4 understood, and

when the lever 19 is moved in l of the arrow m2 of Fig. 1, as hereinafter described. said lever as well as the plunger 18 110 will be locked against movement by the engagement of' the pawl'QQ; 'or the nose 35 the direction l thereofvwith the teeth orv 36 with which the rack 24 is connected and a bottom sleeve portion 37 having 'a detach-"- able cap 38 carr ing astu'fng box 39,. At

one side of the `s eeve 'portion'37 'is nozzle threaded through the nozzle 40, fthe apertures 56 I between the lidv 51 and valve 44, or the'en- 4shownin Figs. 1.v and 3; and itwill benoted 40 with which'is connectedga' flexible tube that thehead v43 ofthe valve-4,4 vnormally seats. von'an annular `flange 46 within the The valve 44 is provided with a down-v' wardlydirectedtubular portion 47 secured to the head 43 as shown at 48, the' base of the tubular portion 47'v being enlarged as shown at `49 and provided with a Areduced t .threaded portion 50 with which is connected a circular lid or'cover 51 and a conical' aperture 52 is formed in the central bottom portion of the lid or cover 51 and the' reduced ortion 50 of theI valve 44..

An air istributer 5B is secured to the bot# tom of the tubular portion 47 of the valve, said distributer having a plurality of horizontal apertures 54 communicating with a vertical aperture 55 which communicates with the aperture in the tubular portion 47,

and said tubular portion' 1s provided inthe top thereof with'a plurality of apertures l, Whichwhen thevalvev 44 is' in its' raised'.

position .as shown in 'Fig'. 3 are placed in communication with the'port or passage 42 in the nozzle 40 by a;chamber 57 in the sleeve portion 37. Withv this construction compressed air 'passes from the tube 41 through the tubularportion 47 and the'apertures-55 and 54 in the-'distributer 53-and out through the conical aperture 52 in the lid or cover 51 in the form ofan annular spray; A radially 'directed nger 58 is secured larged portion 49 thereoand'the free vend of said linger extends beyondthe. lid or cover 51 and isprovidediwith a downwardly directed curved rportion 59, as clearly shown inFig. 4. 'The bottom -face of the' 'lid or cover 51 isfprovide'd,v in thcconstruction shown, withthree annular grooves 60 'which arel so formed as to retain strips. of asbes.. tos orfsimilar substance 61 treated with graphite or similar substance.

One side of the-plunger 18 or thetop por- I tion 36 thereofis provided witha longitudinal slot 62', and a pin or screw 63 is passed `1.',13.;21o,22s4 v ,t i

projectionsv 23 on'. the head 22 of the lever 19. f *t The Lplunger 18 consists of a topl port1on;

in order to support said :model whi Y bedding the' same in"an. investment the through the corresponding sideot'lthe headv .13 of the frame and 'into said slot, and by A' this construction serves to--hold the plungerA 18 against rotation lin .itsverti-cal movement 3 through said head.v

' Theupwardlydir'ected flange' l14" on. the base 11 farms a'jrecess 64 into which one of a number of castingV rings may besu'pported and, in the construction .shown"1n'Figs.' l

to 4 inclusive, ll .have shownv at 465 what` is knownv as an inlay-casting. .ring v.Whichiis' mounted' orjsupportedon the base 11 within the recess 64 by an annular'raised stand 66 having a recess 67 in the top face thereof to receive the bottom portion of the ring 65, 'said A.stand 66 being provided/'centrally with t. y an aperture'68 which formsa fcommunica` tionbetween the casting ring and the aperture 1,5 inthe. basell. 'll-he Stand 66"-is held centrally of the recess 64v'by'guide ring 69A which .centers the stand 66 in -the recess 64, said l,cuide ring bein-gfprovidedwith a thumb and finger piece, 70 t'o permit of its placei ment in'and .removal'from the. recess 64..

In Fig. l of theaccompanyingdrawing .the inlay. ring 65 is-shown partially prepared and in a condition readyfor the melting of themetal employedl prlor-to forming I the casting or, in otherwords, said ring is provided with an inlay mold-71 formed byl a molding wax embedded `inl an investment x v 72,v .and said molding wax is burned out, in .the usual manner to. ormthe inlay mold,

and a vertical sprue way 73'is also formed in the investment inthe usual manner to permit of the passage of-xnetal downwardly into the inlay mold'ZLj The .sprue way 73' communicates. with'-a ='concavoconve'x por-'vv tion 74 inthe top or 'the investment which is' formedby a crucible former 75 similar crucible former 75,. consists of an annular disk 7 6 at one side of which is 'aI projecting .semi-spherical portionf? 7 having-an annular t shoulder 78, and the semi-spherical portion' 7'? is providedcentrally with a`deep aper..A A A with a-waX model of an inlay may be placed usual Vmanner. x

n Figs,Y 1 to 4 inclusive, l1 have shown a I' 'coal gasblow-pipe BOfSupported. in the :base

.T1 ofthe `frame, oran 'extension 81 thereof` by a bent rod S42, which-is forked at its upper and the coal-,gas blow-pipeBOis shown connected withy the extension 85.- rA flexible coal gas supply .pipe 87 is gonnected with the extension86 as illustrated 'in Fig. 2o'f the drawing, and an air supply pipe88 ismounted on -top of the blow-pipe 80 and passes into and centrally throughA the dis- 12o lend Aas shown, at 83;l A Within the forked.end t x A83,'is, pivoted aj valve' device 84ha'v1ng oppo- 'sitely directed tubular -eiitensionsv and' 86,

ias I 1.05 4to that shown in Fighofthedrawing. The

charge 4end of said blow-pipeL as shown at 89 in Fig. 4 of the drawing. A flexible pipe 9G 1s connectedy with the air supply pipe 80 Vand serves to supply air to the pipe 88 and discharge it through the open end of the coal gas blowpipe in the usual manner.

` It will be noted on a consideration of Fig.

of the drawing that the finger 58, or the curved end 59 thereof, bears upon the top of the blouwpipe 80, or the pipe 88 and is sef cured thereto when the machine isin its normal position, and after the coal gas flame from the blow-pipe 80 has heated the gold or other metal 91 in the concave-convex recess f4 at the top of the investment 72 to bring said metal into a molten state, the

lever 19 is grasped by the'hand of the operator and moved forwardly into the position indicated in dotted lines in Fig. 1 in which operation'the lid o r cover 51, the valve 44 and plunger 18 are'moved downwardly and the lid or cover is compressed upon the top ofthe'inlay ring 65 under the tension of the spring 4.5. l

ln the above operation the top of the inlay ring 65 engages ,the inner annular recess 60 in the bottom of the lid. or cover 51, or

l the asbestos 61 therein, and this forms an air-tight connection between the top of the ring 65 and the li'd or cover 51, and in thel downward movement of the plunger 18 with the various parts connected therewith, 'and posite Isides of the air distribute-r 53. The

vcompressed air discharged around the distributor' 53 forces the molten metal 491 through the sprue .way and into the inlay mold 71 in the investment 72. The investment 72 is composed of porous material, and in the above ,operation of forcing the molten metal 91 into the Inold71, the air previously in's Vi mold will' be forced through the investment and through the vap-rtures 68 and 15 in the stand 60 and base 11 respectively.

`When 'the lever 19 has been moved forl wardly to depress the lid or cover 51 onto the paw] 29 with the teeth 23 on said lever the ,top of the inlay ring and under the tension of the spring 45 or as illustrated in Fifi. v3 of the drawing, said lid or cover is held in this position by the engagement of and compressedair under a predetermined Vpressure may be constantly intr'oduced into the top of the inlay ring to force the molten metal into the mold and to 'prevent said-` metal from moving backwardly, or up wardly' through the sprue way, while it is cooling or setting and in this way a perfect inlay casting is made in the mold 65.

In the above operation of moving the plunger 18 downwardly by the lever 19, the linger 58 moves the blow-pipe 80 downwardly into the position indicated in dotted lines 1n Fig. 4, which operation shuts olf the supply of coal gas to said blow-pipe by Areasonof the turning of the valve 8l pivoted within the forked end 83ofrthe rod 82, and this blow-pipe will remain in the position indicated in dotted lines until hnoved upwardly by hand to the position shown in full lines in F il, and is ignited in the usual manner. tion of depressing the plunger 18, after the metal 91 has been heated to a molten state automatically shuts oil the coal supply and opens the valve 114` to admit compressed air into the top portion of the inlay ring 65.

It will be noted from Fig. 2 of the drawing, that the lever 19 is normally held in its inoperative position as shown in Figs. 1 and 2, by a pin 92, which projects into the recess 2O and engages on side of the lever 19 as shown in Fig. 2, said pin beingv normally forced inwardly by a spring 98 secured to the side face of the gooseneck 12 by *a screw 94.

`In Fig. 8 of the drawing, I have shown a nitrous oxid blow-pipe 95 secured to the tu loular extension 85 of the valve 84 in place of the coal gas blow-pipe 80. and itwill be understood that either of these lolouepipes` may be employed at will by the operator.` by simply detaching one and substitutin q the other thereforras both coal and nitrous oXid are commonly used by dentists and others in the melting otgold or other metal used in formingor casting inlays. bridges, plates and the like.

n Figs. 5, 6 and 7 of the drawing. I have shown different forms of casting rings In other words the operai oo which may be substituted for the inlay ring 65 in producing castings of different sizes, as well as of ditierent characters and in Fig.

of the drawing, 1 have shown a. deep casting ring 96' which ts in the recess G7 with in the upwardly directed flange 14 of the base 11 and said ring is of such height that the top face 97 thereofl would be in a plane similar to the plane of the top face ot the inlay ring 65 and, in practice, i provide an annular groove 98 in the inner wall of the .ring 96 adjacent to the top edge 97 thereof which forms a lguide to inform the operator" or user as to the height of the investn'xent to.be placed in such ring. Vhen the ring 9G is employed in the machine the top face 97 thereof will operate in connection with the outer annular groove 60 in the lid or cover 51, or the asbestos therein, to form an casting ring'99 of the saine diameter as the ring 96 but shalloiver in. form, and'which Operates in connect =on' with the outer'recess' 60 in the lid or cover 51, and 1x1-order to saine horizontal plane asthe' t0p"`face"97 of the ring; 96, I employe supplemental base 101 `which Hts within the recess inA the upwardly directed flange 1l of the base 1l ot' the frame, and said supplemental base 101 is 4provided in the top. with'a "recess 102 into which the ring 99 lits andfcentrally of the' supplemental base 101 is ,an apei ture'103, which communicates with the aperture15'in the base 11. The" inner 'face of the ring '99. vis provided adjacent to the top edge 100 with an annular groove 10e similar in all respects to the groove' 9 in the ring 96.

ln Fig. 7 oi' the drawing, 'I have shown at 105 a medium size casting ring, the diameter oi. which is such as to operate in connection with the intermediate annularrecess 60 in 'the lid .or cover 51, and the depth of which is similar tothatof the ring '99 -shown in.

'Fig'. 6 and this ring is used in connection with the supplementalbase 101 but is isupported centrally of the recess 102.n. the top of the base 101 by the guide ring '69 shown; in Figs. 1 to "4, inclusive. The top face 106 of the ring 1,05 is in the saine plane as the ring 105 is also provided with, an annular vgroove 107 adjacent to the top edge. thereof.

It will be noted from the accompanying" drawing that the lidor cover 51 is adapted. for use in connectionwith any-of the casting rings 65, 96,99 and 105 and regardless of which'oi" these vrings is employed -in vthe operation -of-casting inlays, bridges, plates and thel like, an air-tight 'connection is formed between. the top, of the ring employed andthe bottom face 'of the lid or vcover 51 thus preventing, the 'leakage oit' the patatas '1s old and well-known andcom'- monly practised dentists and others.

The chief features @tiny inventionare the i provision of a lid or cover which is adapted tor use in connection with casting rings of any kind or class, means for melting metal employed by a coal. gas blow-pipe, or aV nitrous oxid blow-pipe, means for auto-- matically shutting off the supply of coal' gas or nitrous oXid in the descent of the plungerj'land for y automatically opening the 'supply-of compressed air, as well-jas the provision of 'means for, automatically holding the apparatus in its operative position, and

while I haveshownlvarious details .of 0011-.

struction for carrying. my invention'into'efecty it l will be understoodthat various changes therein and inodiiications thereof may be made,.within the scope'of the appended claims, without departingl from'the spirit of my invention or sacrificing itsad vantages.

Having fully ydescribed myl invention,

' `what I claim' as new and desire to secure by Letters Patent'` 1sz '1. ln a Amachine or" the class described, a

frame, means or supporting a' casting ring in said-frame, a plunger mounted to move verticallyin said frame, a valve carried by said plunger, aco'ver member carried by said valve, 'tensional means for holdmg said valve normally in a closed position, and means for operating the plunger to move it vertically vin the frame and to open'said valve-LM@ l l y 2. In a machine of theclass described, a

y frame, a plungen mounted to move vertically in said frame, '-a compressed air-supply connected with one end portionof the plunger,

a valve in said end of the plunger for controlling thepassage of air into and throughvthe plunger,` tensional means for holding'l said valve normally in a, closed position, a cover member carried by said valve, means *for moving'lithe plunger vertically in the frame, and means for locking said plunger and said lastnamed means in diiierent positions.

operated valve in vsaid plunger, a cover member carriedby said' valve, a pivoted blow-- pipe support and supply device mounted at ,one side of the frame, means for supplying compressedjair to the plunger, said supply being normally closed by said valve, :an air distributer mounted inthe bottom :face of the' cover member, and means for moving the plunger downwardly to bring the cover 'v memberintoengagement with the top face of the casting ring mounted lon the frame and to lmove the plungerl downwardly over air. into said said valve to admit compressed plunger and through said valve.

frame, a plunger mounted tomove verti-4 4.-; In a machine of the class described, a 4 frame, a castingring supported on said cally in said frame and iii-'vertical aline ment wlth said casting ring, a tensionally i operated valve in said plunger, a cover zmember carried by said ,valv e, a pivoted;

blow-pipe .support and -supply device top face of the casting ring mounted on the frame and to move the plunger down-- wardly over said valve to admit compressed y air-into saidplunger and thr'ough said valve,

and means carried bythe valve and cover member for .closing the blow-pipe support and supply device in the downward movement of said plunger.

5. In a machine of the class described, a frame, a casting ring supported on said frame, a plunger mounted to move vertically in said frame and in vertical alinenient with said casting ring, a tensionally operated valve in said plunger, a cover member carried by said valve, a pivotedblow-pipe support and supply device mounted at one side of the frame, means for supplying com pressed air to the plunger, said supply being normally closed by said valve, an air dis.

tributer mounted in the bottom face of the cover member, means for moving the plunger downwardly to bring the cover member into engagement with the top face ot -the casting ring mounted on the frame and to move the plunger downward-ly over said valve to admit compressed air into said vplunger and through said valve, andhmeans for automatically locking said plunger and said last named mea-ns against upward movement.' l v 6. Ina machine of'the class described, a frame', means for supporting a plurality of difi'erent size casting rings in said frame, a plunger mounted in said frame and adapted to move toward and from the casting ring supported by the frame and in axial-alinenient therewith. a cover member carried by said plunger, the bottom face of sa'id cover member being provided with a plurality of, annular recesses having asbestos. paclgiiigs therein, and means `for moving said plunger downwardly to bring said cover member oi an annular packed recess thereof into eli-- gageinent with the top edge oi? a casting ring supported by the frame.

7. 'In a machine or the class described. a frame. means for supporting a plurality ot different casting rings in said trame, :i plunger mounted in said frame and adai'ited to move toward and from the rusting ring supported by the trame and in axial aline-l ment therewith, a. cover memberl carried by said plunger, Athe bf tom fare of said cover member being provided with a plurality oi annular recesses having asbestos pachings therein, means for supplying compressed air to said plunger7 a tensionally controlled valve for normally closingsaid l supply to said plunger, means for moving said plunger downwardly to bring said 'cover member intoengagement with a casting ring supported by the frame which operation opens the valve device to admit compressed air into the plunger, and means for discharging said air admitted into the plungersthrough the bottom face of said cover.

member.

8. In a machine of the class described, a frame, means for supporting a plurality of diii'erent size casting rings in said frame, a plunger mounted in said frame aad adapted to move toward and from the castingV ring supported by the frame and in axial alineinto engagement with a casting ringsupw ported by the frame which operationopens the valve device to admit compressed aii into the pli'i'nger, means for discharging saidl a'ir admitted into tlie..plunger through the bottom face ot said cover member, and means'for automatically looking said plunger, valve and cover member in said last` named position. y ,Y Y

9. In a machine of the class described, a franiqmeans for supporting a plurality of dilerent size casting rings in said frame. a plunger mounted in said frame and adapted to move toward and from the vc ast-v ingvring supported-by the frame and in axial alinement therewith, a cover member carried by said plunger, the bottom face oi said 'cover member being provided with a plurality of annular recesses having asbestos packings therein, means for supplying compressed air tosaid plunger, a tensionally controlled valve -for normally closing said supply to said plunger, means for moving said plunger downwardly to bring said cover member into engagement with a' cast- `ing ring supported by the trame which oper ation opens the valve device to admit com-- pressed air into the plunger. u'ieans for discharging saidair admitted into the plunger through the bottom face of said cover mein-- ber, means for automatically locking said plunger, valve and e yrv member in said last named position, a :low-pipe pivotally supported at one side of the frame. and means for automatically shutting ofi' the supply to said blow-pipe in the downward movement of said plunger.

l0. ln a machine of the class described` a trame, means for supporting a plurality of casting rings in said frame, a plunger mounted said frameand adapted to move'.

towardI from the casting ringsupported by the vframe and n'aXialV-alinement theresaid cover mem with, means for holding said plunger nor'- mally'in a raised position, 'a cover member carried'by said plunger, the bottom Jface of plurality of annular" p`aeked recesses, means forv v supplying compressed. `au' to said plunger, said supply being vnormally closed, vmeansffor vn'ioving.; the plunger downwardly to bring said cover member'into engage# vment with'a` casting ring supported by thev .frame which operation automatically opens the supply of compressed air tothe plunger,

means'l for discharging'the compressed air supplied to the plungerthrough 'and around an air distributer vsecured in the' bottom face of the" cover'meinber, a blow-'pipe'pivotally supported at one side of the rame,"means for auton'iat-ically shutting of the 'supply to' saic'lbloywpipe in 'the 'downward movement I of the-plunger, andmeans lfor locking saidv plunger land said vcover member Aagainstfup- ILA` casting'machine ofA the elassdef' 4 scr1bed,.compr1s1ng @frame consisting of a base and upright gooseneck portion having a' vertical' cylindrical head, "means involving' the base forsupporti n'gcasting rings thereon,

a plunger mounted in ftliecylindrical head of the gooseneek,portionof the frame,va lev'er "'pvotedwithin the ,iopjof the'gooseneck por-f .tion of the frame, a -racl'z'se'cured in the plunger, the pivotedend y01:' saidlejver being provided withaplurality of teeth oi'projeetions adapted to cooperate, with the rack in said plunger togmove it vertically, a springvde# l'pressed valve `device mounted in the Alower end portion o f the plunger, means for adm'itting compressc'l air to said end of" the plunger, said means being normally closed by said valve device, said valve device eX- tending beyond the end of the plunger and a cover member mounted on. the extensionofI said valve, an air distributer Countersunk 1n said cover member and secured 1nv the extension of the valve, a pivoted blowpipeI support and .supply device mounted at one side of vthe fran'ie, means Carried by y said valve device and said cover member for er'vbeing providedwith a wardmovement when in its depressed .-posi.

,the downward movement of said plunger.

depressing s aidbloW-pipe support and supply device in the downward movement of the plunger, a pawldevice secured in the gooseneck portion of the frame and operating in connection' with the teeth or projec- 1tions on the pivotedend of said lever for locking the same against movement in one direction, and means 'for preventing the ro- 60 tation, of-'saldplunger in its vertical move# nient.

, =12. A casting' machine of theclass de- "jscribed, omprising a frame, means for supportm one of' a number of casting rings 65 of diiierent'-heights,'and diameters -1n sald frame, a 'cover member mounted to move toward and from a casting ring supported in said frameend means on saidcover member forforming gan" air-tight connection bel tween the 'same' and the top ring supportedon said frame.

of the-casting '13. In a 'casting' machine of the class described, acovermember provided with fr plurality'.'ofj'circular ring seats, onefof said 75 u' vvrm'g seatsbemg .adapted to form an 'airtight 'connection-with any one of' a number of' castingv rings',-` .of' di'erent sizes supported- -beneathfsaid cover member and in axial a'linement' therewith.

`14.l A casting machine of the Class 'described eomprising a frame, means for supl porting a casting ring on said frame. a

'.-means' for connecting either' a'coal' jga's o'r'90 .nitrous oxid blow-pme with said 'supportv and supply. chev1ce,fand a linger carried by the plunger for automatically' moving the blow-pipe into an inoperative' positionA Ain In testimony that I claim the foregoing -as my invention I have signed my name in presence of the subscrlbmg Witnesses this QTthd-ay of November, 1918.

WALTER Gf'i E. HARVEY.

iVitnesses: I

C. E. MULREANY, H. ETHOMPSON.

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