US1892947A - Acetylene generator - Google Patents

Description

Jan. 3, 1933. w. w. HARRIS 1,392,947

ACETYLENE GENERATOR Filed Oct. 5. 192a INVENTOR, Wiilnam W. Harms HIS ATTO EYS.

Patented Jan. 3, 1%33 VJILLIAE/I VT. HARRIS, OF BRGCKTON, MASSAGE SETTS ACE'IYIZENE GEN Application filed (Jctober 5, 1829.

This invention relates to acetylene generators and particularly to the type of generators wherein the carbide feeding mechanism, together with its means of actuation, compris- 5 ing a spring pressed yieldable gas wall carrying a reciprocating feed plunger operating through a restricted feed opening, is entirely self contained, in other words, wholly incorporated within the generator and thus rendering the apparatus especially adaptable for portable purpose.

.An object of the invention is to provide an eiiicient acetylene generator of simple and economical structure wherein the arrangement of working parts is such as to permit of quick and accurate assembly in ordinary factory practice thereby insuring uniform operating eificiency of the factory product.

A special object of the invention is to provide an acetylene generator having a carbide feeding mechanism highly sensitive to slight changes in gas pressure within the generator and automatically responsive to such slight or changes to generate gas only in quantity commensurate to any variation of service requirement, thereby insuring a much desired degree of pressure stability in the service output, the particular formation of the feed plunger part of such carbide feeding mechanism being an important means to this end.

Another object of the invention is to pro vide an acetylene generator having a manual control part of-the carbide feeding mechanism for starting or stopping the generation of gas which is incapable of being either willfully or ignorantly operated to manually force the feeding of carbide beyond the amount deliverable by the feed plunger under the normal working of the spring-pressed yieldable wall and the further incorporation in such feed control mechanism of means which will, upon any occurrence of abnormal pressure within the generator automatically och the feeding mechanism in nonop- 'on and thereby prevent any i er generation of gas.

A further objectof the invention is to pro- ."lQ an acetyl ne generator having a carbide dust screen rcmovably interposed between a Serial No. 397,620.

primary gas outlet and a secondary distributing cavity which maybe provided with one or more service outlets together with means of access thereto which permit the withdrawal of the screen, for cleaning or replacement purpose, and without any disarrangement of such service outlets.

Other objects and features of my invention, together with further detail concerning the objects already stated, will appear more fully from the following description and accompanying drawing in which Fig. l is a view in vertical central section, a portion of the water reservoir and a portion of the service structure being broken off, of an acetylene generator embodying my invention and showing the service connection as particularly adapted to the use of the generator as a flood light.

2 is a partial view in vertical central section showing the fixed parts of the generator exactly the same as in 1 but with the working parts shown at a certain point of operating position. 75

F ig. 8 is a broken view in side elevation, at right angle to Fig. 1, showing the upper structure of the generator, with dotted detail of the crank portion of the control means, and also showing the upper service arrangement 80 for adaptation of the generator to us as a flood light.

Fig. 4 is a perspective view of the carbide dust screen scctionally shown in Fig. 1.

Fig. 5 is a full perspective View of the locking spring 32 portionally shown in Fig.

1 and Fig. 2.

Referring to the drawing, 1 is the upper portion of the water reservoir which also constitutes the gas generating chamber. The 90 carbide container 2 is formed with an open top terminating in an outwardly extending flange 2a and with a lower neck portion 25 of reduced diameter wh ch is flanged outwardly at its lowermost termination to form 95 a contacting face for the rubber gasket 3. Lhe gasket 3 is carried in a circumferential depression 164 of the water reservoir 1. The water reservoir is provided with ears 4: to which the swing bolts 5 are pivotally attached by the pins 6. Two semicircular bands formed with laterally extending arms 7 are clamped on to the carbide container neck 2?) is spaced relation'to each other by the cross bolts 8, thus forming a yoke having open sides for the reception of the swing bolts 5. A gas tight joint'between the water reservoir and the carbide container is effected by gasket compression upon screwing down the wing nuts 9. The lowermost inwardly inclined bottom wall of the carbide container 2 is formed by a secondary funnel shaped piece 20 having a vertically extended mouth formation 2d which is threaded to receive a correspondingly threaded portion of the valve member 10. The valvememb'er 10 is provided with the lugs 100; which not only serve as finger opposition in its manip- 'ulation. but also serve as interference means through contact with the inwardly extending lip 16 of the water reservoir mouth and thus act to prevent the complete unscrewing of the valve member and thereby avoidthe numeral 11. Such single designation will simplify any functional description which may follow, The component parts of this.

yieldable gas wall are, however, further described and designated in the drawing as follows: The rubber diaphragm '12 is provided with an enlarged bead portion 12a at its inner circular termination. A central rigid spring'supporting piece 13 is formed with an annular groove 13a in its lower side to receive the diaphragmbead port-ion 12a and a gas tight joint is effected through compression therein by means of an underlying circular plate lt and the headed bolt 15. The diaphragm 12 is preferably moulded'to form a circumferential recess, near its outer extremity,adapted to envelop the flange 2a of the carbide container 2 on three sides thereof as shown at 12?) thereby affording double assurance of a gas tight joint when this part of the diaphragm, together with the flange 2a, is compressed betweenthe flattened section 16a of the generator cover 16 and the clamping ring 17 by means of the bolts and nuts 18 which are shownin Fig. 3. The generator cover 16 has an upwardly extending cylindrical housing portion 165 which, in. conjunction with the cap 19,forms a complete housing for the enclosed parts of the operating mechanism.

The full importance of such protection of working parts against weather elements and the entrance of grit such as sand or'cinders, in a generator adapted to out of'door use, will interference ,in its be apparent after further description of my apparatus and it will then be seen that the particular design and arrangement of operating parts, to permit of their easy assembly under cover of such housing, constitutes an especially valuable feature of my invention as a whole.

The following description ofparts of my generator which act in combination with the yieldable gas wall, heretofore described, to effect the automatic generation of gas in quantities commensurate with a variable service output will be comprehended more fully if it is first understood that such automatic action is brought about through changes in balance of'spri'ng pressure upon the outside of the yieldable gas wall 11 as between the slightly varying :gas pressure exerted against the inner side of said. wall.

It should be further understoodthat these slight changes in gas pressure and the consequent changes in position of the gas wall, together with the feed plunger 20 suspended therefrom, are brought about by withdrawal of gas from the generator for service use and the resultant feeding of carbide in quantity only suil'icient to supply gas for such service output and to cause the intermittent action of the gas wall 11. While a spring pressure on the yieldable wall of about twenty pounds tensional force is required to establish a desired gas pressure of about two pounds within the generator, it is a fact that when this balance of pressure becomes so established,

the normal operative movement of the yield.

frictional interference in the working parts or of carbide; tlierebetween will cause an irregular feeding of carbide resulting in undesirable fluctuations of gas pressure. For this reason, the importanceof the particular design of certain parts, together with their assembly arrangement, which I am about to describe. will become more apparent. The feed plunger 20 is preferably loosely suspended from the yieldable gas wall 11 and in laterally swinging relation thereto, thus preventing any possible rigid frictional 21 in connection with a loosely fitting bear- 1 ing 22a in the adjusting stud 22. Tliestud 22 vided for rigidly securing the stud 22 in place after the proper assembly relation is effected as described. The [stem portion of the feed plunger 20 is preferably of tubular construction showneand may be'provided with the gas distributing ports 20a. A parreciprocatory action through the valve member feed opening 10b. ,Suchsuspension is effected by the cotter pin ticular object of such tubular construction is to provide a more direct passage for the gas from the generating chamber of the water reservoir 1 to its point of action upon the yieldable gas wall 11. Instead of having to pass through the entire body of carbide, it will be seen that the newly generated gas, after passing through the valve member feed opening lOi), nee-c only penetrate through tne small body of carbide surrounding the feed ing portion of the feed plunger 20 oefore entering the lower open end 200 of the tubular stem portion of the feed plunger and that the gas may then pass freely therethrough and out of its upper open end 20d to act directly upon the gas wall 11. It will be understood, from previous reference to the sensitiveness of the yieldable gas wall to slight changes in pressure, hat such direct action of the gas thereon results in a more ready response of the feed plunger action in shutting off the delivery of carbide after each intermittent discharge of same and thus reduces the range of undesirable fluctuations of gas pressure within the generator.

The carbide feeding portion 20?) of the feed plunger 20 is of spiral formation and, for a generator particularly adaptable to flood light purpose as outlined herein is preferably formed by twisting rectangular metal stock and leaving an upper fiat portion 20d for telescoping into the tubular plunger stem where it is secured by the rivet 206. A lover flat portion (not shown) also provided for inortising into the solid feed plun er tip 20f and is secured thereto by any suitable means. The upper termination 20g of the plunger tip is )referably of semiconical formation on both sides of the mortise therein. It will be understood that the stem and tip portions of the feed plunger are of cylindrical formation and of slightly less diameter than the valve member feed opening 10?) to allow their free entrance therein. The greatest cross sectional dimension of the spiral formation 20b is somewhat less than the diameter of the valve member feed opening 106, the purpose being to provide suiiicient clearance between the spiral edges and the periphery of the feed opening to prevent the wedging of particles of carbide therebetween.

It will be understood that while I have expressed a preference for the use of rectangular stock for forming the spiral part of my feed plunger for the particular purpose cited in this application, other cross sectional forms may be used to particular advantage for different adaptation of the generator, such, for instance, as square stock in cases where only a limited delivery of carbide is required to supply a comparatively small gas output.

The spring supporting piece 13 is provided with a raised circular portion 13b for registration of the lower end of the pressure spring 24-. The upper end of the pressure spring 24 is maintained under compression by the seating thereon of four downstanding prong portions 19a (only two of which appear in the drawing) of the cap 19. Further downstanding lips 19b of the prong portions 190 provide the means for central registration of the pressure spring 24. The cap 19 is secured in assembled position by means of screws 25 see Fig. 3-which pass through ie housing 16?) and are threaded into the prongs 19a. The crank 26 together with its handle portion 26a provided for manual control of generating operation is shown, partly in full and partly by dotted detail, in Fig. 3. The main shaft portions 26?) and 260 are journaled in directly opposed sides and at the extreme top of the housing 16?). For convenience of assembly, such journaling is effected. by providing the bearing perforations in the housing 16?) with upper open sides so that the crank 26 may be dropped into place and be finally retained there by the cap 19 when the latter is in fixed position. A lug portion 26d of the crank 26 is shown in Fig. 3 as being in contact with a projecting portion 190 of the cap 1, such contact affording a stop against further counter clockwise revolution of the handle 26a, this being the position of the said handle when the crank 2'6 is in the position shown in Fig. 1. Upon a clockwise movement of the he dle 26a to the extent of approximately one half revolution the opposite side of the same lug portion 26d contacts with the cap projecting portion 190 and prevents further movement of the handle 26a in that direction. The connecting rod carrier 27 is of U shape formation having openings 27a in both its arms adapted to a sliding fit on the connecting rod 28. It will be seen that such combination of the carrier and rod forms a complete bearing for the crank arm shaft 26d. The connecting rod 28 has an enlarged lower end portion 28awhich is coupled in loosely swinging relation within an upstanding cup-shaped portion 130 of the pressure spring supporting piece 13 by means of the pin 29. The screw 30 is threaded into the upper end of the connecting rod 28, the head of said screw serving as a stop for the sliding carrier 27. The loosely coiled s aring 31 is carried by the connecting rod :28, its tensional force being exerted between the lower enlarged portion 280/. of said rod and the lowermost arm of the carrier 27 and thus serving to normally maintain the upper arm of said carrier in tens onal con .ct with the head of the screw 30. The particular functional er'iect of such arrangement; of the spring 31 will appear in the general explanation of generator opera tion to follow hereinafter. The locking spring 32 is fully shown in perspective in Fig. and the description of its assembly relation will be clear by reference to its por} tional numeral designations in this figure. It is held in place by positioning its coils 32a on the ends of the pin 29 with its free ends 88?) communicating therewith. :closely woventextile fabr1c39 is crimped 32b resting on the pressure springsupportingpiece and with its loop portion'32c exerting tensional force against one side of theenlarged end portion 28a of the connecting rod 28. Such action of the spring 32 serves to convert the manual control mechanisnrtoautomatic safety locking means as will bemore fully explained hereinafter.

- A cavity for receiving the screened gas before it passes to the service outlets therer from is provided in my generator by means of the T 3a which is secured to the carbide container 2 by means of the nipple 35 and the lock nut The outer opening of the T 34: is closed a removable plug 87, access'to' thecavity 33 being thereby aflorded forthe bodily l1Z'lOV 1l f()1 cleaning or renewal purpose of the carbide dust screen as fully assembled and shown in perspective in Fig. l. The carbidedust screen is comprised of a body part 38 having a central gas passage 38a therethrough and with the cross inlets A disc of over a reduced section 380 of the body part and the gathered circumferential margm of the fabric is bound tightly to the enlarged body portion 38d by means of a closely fitting ferrule 40. The vieldable packing ringetl is backed by the shoulder body portion 386.

A coiled spring- 42 is secured to a reduced projection of the body '38 by meansofthe pin 43. The spring i2 is of suiiicient length to insure, through its tensional compression by the plugSY, adust proof contact between the pa cking ring 41 and the face of the nipple35.

It will be seen that the displacement of the plug 3? permits the removal, of the carbide dust screen as a whole, as heretofore described, and without in any way disturbing the service distribution outlets from the cavity 33, and which are shown and designated as the extension light gas cook ll and the standpipe 45.

In the flood light adaptation of my generator as shown, the standpipe 4-5 is supported by v the bracket 46 and is surmounted-see Fig.

The simple assembly of the carbide container, yieldable gas wall with feed plunger, connecting rod and locking spring attachment, and the cover with its open endedhousing has already been madeplain. The exact manner and order of the assembly of the completely housed operating parts may be more clearly set forth as follows 1' The spring 31-is slipped over the connecting rod 28; the pressure spring as is dropped into its lower seat; the carrier'27 is placed on the crank-shaft 26d and the carrier arm openings Q'Ta-Yarethen telescoped ontothe connecting rod where they are retained by insertion of the screwBU. The ends of the'crank main shaft are then dropped into the open-sided housing bearings and the positioning of the cap. 19 puts the pressure spring under proper tension and completes the assembly.

I The charging of the generator is accom plished by removing the carbide container from the water reservoir. The. latter (not fully shown inthe drawing) is charged with water to a certain indicated level, leaving a free space in its upper neck portion partially shown as l in F 1. The carbide'container 2 is filledwith carbide by inverting and the removal of the valve member 10 for that purpose. When thus charged and reassembled as in Fig. 1, the generator is ready for starting To start the generation of gas, the manually operable handle part 26a of the feed control means is swung in clock-wise direction and the entire carbide mechanism-ihcluding the yieldable gas wall 11, the feed plunger 20, the crank 26, the carrier27 andthe connecting rod 28assumes immediately the approximate mean operating position shown in 2. In other words, itis in approximately th1s position of the operating 'IllQCllttlllSllT" that the primary feeding of carbide takes place and that the balance of pressures, as between the spring pressure on top of the yieldable gas wall and the gas pressure .on the under side of same, becomes established. After this balance of pressures becomesso established, the feeding of carbide and consequent making of gas in limited quantity proportionate to the service requirement, be-

comes entirely automatic. It should be particcularly understood that my carbide feeding mechanism does not operate as a :charged to deliver lined and perhaps excessive amounts of carbide and which would require pronounced and extended strokes of the reriprocating plunger. While I have'provided fora considerable possiblelength of thefeed plunger stroke, it is by no'means' fullyQused in the actual carbide feeding action. The main purpose of such length of stroke is to permit the yieldable gas wall to assume an approximate midwayposition of its complete flexible movement when the carbide feeding relation between the spiral feed'section 20b of the plunger and the feed opening lObis established. When the yieldable gas wall 11 is in this approximate midway position, as shown in Fig. 2, the feed plunger is lowered so that its conical portion 20g is approximately in register with the periphery of the feed opening 106. It will therefore be seen that onlya slight further down -war. movement of the feed spiral 207) is required to permit a delivery of carbide and that only a slight upward reaction of the feed plunger is necessary to stop the carbide delivery. This results in the establishment of an automatic gentle breathing action of the sensitively balanced yieldable gas wall wit its cooperative feeding mechanism, such movement being accelerated by increase in withdrawal of service gas or being entirely stopped by the mere shutting off of the service output. Such resulting stoppage of automatic action and further making of gas by shutting off all service output doesnot mean that the feed mechanism has assumed the locked position shown in Fig. 1 but simply that the feed plunger is held just high enough, by pressure of gas shut within the generator against the. gas wall, to prevent delivery of carbide. The

carbide feeding action would be again automatically resumed upon renewed service withdrawal and without any manipulation what ever of the control handle 264:.

It will of course be understood that the generating of gas may be entirely stopped at any time by manually swinging the control handle 26a in counter-clockwise direction to its approximate down-standing position, as shown in Fig. 3, thus leaving the operating mechanism locked in position shown in Fig. 1. It will also be obvious that no further gas can then be maderegardless of any attempted service withdrawal-until the control handle is manually swung in clockwise direction when the crank 26 is thrown off center and the pressure spring 24 thereby allowed to act. Upon such starting manipulation of the control handle, it immediately assumes its approximate midway operating position where it works with a slight to and fro swing which is exactly indicative of the internal carbide feeding action. lVhen the control handle travels the limit of its half circle swing and stands straight upin direct opposition to its position shown in Fig. 3it indicates that the carbide charge has become exhausted.

It will become fully apparent, from the foregoing description of automatic operation, that the maintenance of a comparatively stable gas pressure within the generator is due to my provision of a carbide feeding mechanism that is highly sensitive in reciprocal response to slight changes in gas pressure and that such responsiveness has been attained by an arrangement of parts which practically precludes the possibility of abnormal or varying frictional interference. The spiral plunger formation 20?) and its working relation to the fixed feed opening 106 is an important part of this provision. In addition to its lateral freedomdue to the swinging suspension of the plunger stem-and consequent compensation against wedging of refractory particles of carbide between the spiral edges and the fixed peripl'lery of the feed opening 10?), such wedging is further guarded against by the constant diagonal change in operatifie contact relation between the spiral ed es and said fixed periphery. yond these provisions against undue frictional interference there remains the prime function of effecting a limited but ready delivery of carbide through a restricted feed opening together with means for the quick retardation of such delivery and it is in the accomplishment of this function that my spiral plunger formation becomes especially important. It will be readily seen that, upon downward movement of the feed plunger, the general spiral contour acts both as a carrying and gentle forcing means to insure carbide delivery and at the same time presents a certain amount of opposition to direct carbide gravitation, thereby tending to prevent overfeeding before the plunger reaction takes place. it will likewise be seen that with the first upward movement of the plunger, this same spiral contour has a lifting and flow retarding efl ect throughout its entire carbide contacting surface which serves toward preventing excessive carbide delivery while ascending to its fully shutoff position.

in generators to be used for illuminating purposes it is desirable to secure dehydration of the gas by having it pass through the carbide container on its way to the service outlet. Such desired practice results in the accumulation of a considerable amount of carbide dust in the lowermost portion of the carbide charge through a certain-although small-proportionate disintegration of the latter in taking up the moisture from the newly generated gas. This dust accumulaticn becomes most pronounced when a generator is operated continuously throughout the duration of its carbide charge and at approximately its full gas output rating. Such extreme operating conditions are not only common in generators adapted to flood light purpose such as l have illustrated but may almost be said to be the general rule. It has been found that various carbide feed plunger designs wnich work satisfactorily when the generator is not 0 erated to fullest capacity of carbide charge and gas output, fail to give efficient service when subjected to the extreme conditions common to flood light operation, on account of becoming either partially or wholly clogged by lime accumulation caused by the carbide dust contacting with the condensation which takes place on the feed plunger surfaces that are intermittently excatin posed to the steaming conditions within the generating chamber. It is in overcoming this fouling condition that the spiral plunger formation which I have provided becomes espec ally important.

The explanation of its self cleaning function seems to lie largely in the scouring action of live carbide in passing over the continuously smooth spiral groove surface and the fact that the carbide passage opening although of constantly changing location, remains of never varying crosssectional area at all positions of the reciproi feed plunger. I

It is in the consideration of this dust ac 3 cumulating condition within the carbide container that another valuable feature of my tubular plunger stem provision becomes apparent. While it is a fact that more or less carbide dust ispresent in the normal charge of carbide, and especially so in granulated carbide such as is commonly used in the class of apparatus I have described, such dust does not become troublesome in generator opera-' tion until it accumulates in excessive proportion at ornear the feed opening. For this reason, any further production of carbide dust through dehydration of the moist gas is of no particular consequences providing it is somewhat distributed throughout the carbide charge. It will be seen that the tubular plunger stem provides means for more ready and general distribution of the newly generated moist gas throughout the carbide con tainer and it is to this end that the gas distributin'g ports a in the plunger stem may be provided.

By reference to the mean position of the working mechanism when the generator is in operation, as shown in Fig. 2, it will be seen'that the feeding of carbide can not be forced by the manual swinging of the control handle 26min further clock-wise direction.v

The only result of such movement would be I the sliding down of the carrier 27 on the connecting rod 28 and the compression of the light connecting rod'spring 31. As has been stated, the sole function of the spring 31 is to maintain the carrier 27 in contact relation with the head of the screw 30. The purpose erator. It willbe seen by reference to the position of parts as shown in Fig. '1, that there is a small space between the cover formation 160 and the outer portion 13d of the pressure spring supporting piece 13. The efiect of any excessive gas pressure withinthe generator would be the abutting of these substantial parts and without any strain onv the: control mechanismbeyond the slight compression of the spring 31as the connecting rod 28 Would simply slide upward through" thecarr-ier arm bearings 27a.

After the foregoing description of gen-- eral operation, the means employed for 0on verting the control mechanism to positively acting safety locking purpose can be more" clearly set forth. It has been explained that in normal operation the control parts'are in approximately the position shown in Fig.2. Sufficient excess gas pressure within the generator would result in moving the crank 26 to its extreme uppermostposition and the locking spring 32' then acts, through the con necting rod medium, to throw the crank 26 past center and to thus positively lock the carbide feed plunger in the shut-oil position as fully shown in Fig. 1. It may be observed that the sliding relation between the carrier 27 and the connecting rod 28 is an essential feature of my safety locking provision as, if the said carrier and rod were in fixed relation, the force of excessive gas pressure would be exerted against the crank 26 in itsuppermost position and the locking spring I 32 would be incapable of forcing the crank past center to the positively locked position shown.

The fact that thissafetylocking means serves to prevent any resumption of carbide feeding until manually and intentionally released and also. that its automatic action is positively as sured regardless of the position of the gen erator, renders it an especially important adjunct of my invention.

Having now set forth the objects and nature of my invention and illustrative structures embodying the principles thereof, what I claim as new and useful and of my own invention, and desire to; secure Letters Patent, is:

'1. In an acetylene generating apparatus comprismg a carbide container having a re-v stricted carbide delivery opening and pr videdwith a yieldable gas, wall,..means for adjustably suspendinga plunger from s gas wall, the said plunger having a carb feeding portion operating throughthe delivery opening, a cover backing for gas wall having an upwardly eXtendingpor-.

t ion forming closedside walls of an open end ed housing, a cap piece forming a cover for s ar d houslng, the sa dcappiecehaving portion pro ect1ng beyond the wall of said. hous- 'i'ng, a pressure spr ng resting upon said gas wall and maintained under tensionthereon'by the said cap p ece, a shafthaving a central crank formation operating within said hous ing. a handle connected with an endof' said.

shaft exteriorly of said housing, the said han- I for said housing, pr

dle being provided with a lug which in co-operation with the proJectingportien of said cap piece limits the revolution of the said t i carrier bearing for said crarformation a d slidablv cor d v" ind hi lower e otallv connew o with said vicldable the 'd connecting rod be' upon said gas wall and l sion thereon by said cap a central cl f the said he end of said a carrier be. and connect gas wall.

8. In an acetylene generating apparatus comprising a carbide container provided with a restricted carbide delivery opening and a yieldable gas wall, a plunger suspended from the said yieldable gas wall and provided with a spirally formed carbide feeding portion for operation through the said carbide delivery opening, the said plunger being further provided with a. hollow stem portion affording a gas passage from the upper termination of its spiral formation to a point adjacent to and below said gas wall, pressure means acting upon said yioldable gas wall and manual- 1y operable means co-operating with the said gas wall and said pressure means for maintaining the spirally formed carbide feeding portion of said plunger entirely Within the said carbide container, said manually operable means controlling said co-operating means.

4. In an acetylene generating apparatus comprising a carbide container provided with a restricted carbide delivery opening and a yieldable gas wall, a plunger having a spirally formed carbide feeding portion, means for loosely suspending said plunger from the said yieldable gas wall in swinging relation thereto to provide freedom of lateral movement of the said carbide feeding portion in its reciprocation through the said carbide delivery opening, pressure means acting upon said yieldable gas wall and manually operable means co-operating with said gas wall for maintaining the spirally formed carbide feeding portion of said plunger entirely within the said carbide container, said manually operable means controlling said co-operating means.

5. In an acetylene generating apparatus comprising a carbide container provided with a restricted carbide delivery opening and yieldable gas wall, a plunger having a hollow stem portion and provided with a spirally formed carbide feeding portion for operation through the said carbide delivery opening, means for loosely suspending said plunger from the said yieldable gas wall in swinging relation thereto, pressure means acting upon said yieldable gas wall and manually operable means co-opcrating with the said gas wall for maintaining the spirally formed carbide feeding portion of said plunger entirely within the said carbide container, said manually operable means controlling said co-operating means.

6. In an acetylene generating apparatus comprising a carbide container provided with a restricted carbide delivery opening and yieldable gas wall, a plunger having a hollow stem portion and provided with a spirally formed carbid feeding portion for cooperation with the carbide delivery opening and means for moving the plunger axially whereby to cause a reciprocating motion of the spirally formed feeding portion at the carbide delivery opening.

7. In an acetylene generating apparatus comprising a carbide container provided with a restricted carbide delivery opening and a yieldable gas wall, a plunger having a hollow stem portion and provided with a spirally formed carbide feeding portion extending through the carbide delivery opening and cooperating with said opening to feed carbide therethrough and means for yieldingly suspending the plunger to permit reciprocating axial movement of the spirally formed carbide feeding portion of the plunger whereby to feed carbide through the delivery openmg.

In testimony whereof I have signed this specification this 3rd day of October, 1929.

VIILLIAM V7. HARRIS.

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