US2106972A

US2106972A - Acetylene generator

Info

Publication number: US2106972A
Application number: US759515A
Authority: US
Inventors: Motte Maurice P De
Original assignee: Union Carbide and Carbon Corp
Current assignee: Union Carbide Corp
Priority date: 1934-12-28
Filing date: 1934-12-28
Publication date: 1938-02-01
Anticipated expiration: 1955-02-01

Description

M. P. DE MOTTE ACETYLENE GENERATQR Feb. 1, 1938. 2,106,972

Filed Dec. 28, 1934 be, o

INVENTOR MAURICE P. DEMOTTE i AZEORNEY Patented Feb. 1, 1938 UNiTED STATES PATENT OFFIQE ACETYLENE GENERATOR York Application December 28, 1934, Serial No. 759,515

16 Claims.

The invention relates to acetylene generators and more particularly to the carbide feeding and gas pressure control mechanism of acetylene generators of the medium pressure, carbide-to-water type.

Such generators are frequently made in portable sizes adapted for being moved from one place of use to another while they are fully charged, and in order to prevent superfluous gas accumulation during such movement they are usually placed in inoperative condition by closing the carbide feed valve. These valves are not water-tight however, and when the generators are moved over rough ground such as that around 5 construction projects or along Welded pipe line installations, the splashing water within the generator will pass the carbide valve and reach the carbide within the hopper. This not only causes a waste of gas but the wet carbide sludge formed so in the hopper interferes with the proper flow of carbide when the generator is restored to operating condition. Therefore, one of the objects of this invention is to provide such a generator with a carbide feed valve that may be closed and sealed against the passage of water or moisture.

When generators of this type are recharged it is the usual practice to manually close the carbide feed valve and then release the gas pressure within the generator. This causes the automatic valve control mechanism to exert its full operating force on the manual valve closing mechanism, and this places an objectionable strain on the valve operating and control structure. Therefore, another object of this invention is to provide such a generator with both automatic and manual valve control means of which either may operate to close the valve without placing an objectionable strain on the other.

Generators such as this are frequently used to supply acetylene for welding operations on construction projects which are far removed from a source of supply. As their place of use changes they are frequently transported across country over rough ground and used in unprotected locations amid considerable construction activity Where they are the only source of acetylene supply. During such use they are subjected to considerable hazard and at times are accidentally damaged. Heretofore, when such generators were damaged, it has been necessary to suspend work while they were dismantled and repaired, and this caused undesirable and expensive delays. Therefore, another object of this invention is to provide such a generator with a carbide feeding and gas control mechanism of one or more integral units which, when damaged, may be quick 1y removed and replaced by operative units, so that damaged generators may be restored to serv ice more quickly.

Heretofore, during normal operation of prior generators of this type, small particles of feeding carbide accumulated on the interior mechanism, and then when such generators were moved, especially over rough ground, the shocks of transportation dislodged this accumulation which dropped into the water within the generator and produced an undesirable generation of gas. Therefore, another object of this invention is to provide such a generator with an interior mechanism upon which such accumulation will not collect, and to also provide such a generator with a shield to prevent accumulation of floating particles such as dust from collecting on the portions or" the operating mechanism Where it will interfere with its normal operation.

In generators of this type the gas pressure is usually controlled by a spring balanced diaphragm, and due to the relatively high pressure Within the generators such springs have heretofore been comparatively heavy and stiff, and their operating range has been Within a relatively small degree of compression. With such springs the resistance to compression varies rapidly with the degree of compression with the result that the sensitivity of the control mechanim was much, less than that desired. Therefore, another object of this invention is to provide such a generator with pressure control mechamsm that is much more sensitive to changes in pressure than those employed heretofore.

In order to vary the operating pressure in generators of this type a manually adjustable screw is usually provided to vary the tension of the pressure control spring. The outer ends of these screws usually project outside of the generator Where they are exposed to injury, and as these screws movewith adjustment and consequently project various distances it is difficult to cover or protect them. Therefore, another object of this invention is to provide such a generator with a pressure control adjusting mechanism that projects a fixed distance and is protected from exposure to injury. Another object is to provide a pressure control adjusting mechanism that operates more easily than those known heretofore.

Still other objects are to provide such a generator that is more compact, more self contained more sensitive, more rugged, more interchangeable, and more reliable and efiicient than those known heretofore.

These and other new and novel features of the invention will be more fully described and explained in the following specification and the accompanying drawing in which:

Fig. 1 is a front View of an acetylene generator embodying my invention with one of the doors of the accessory chamber open to show the location of the accessory equipment;

Fig. 2 is a horizontal sectional view substantially along line 22 of Fig. 1 showing the general arrangement of the control mechanism;

Fig. 3 is a fragmentary vertical sectional view along line 33 of Fig. 2 showing the structure of the control mechanism in detail; and

Fig. 4 is a vertical sectional view of the isolated spring assembly unit.

The invention, as illustrated in the drawing, may be embodied in an acetylene generator of the medium pressure, carbide-to-water type, having a closed casing of symmetrical contour comprising a water containing and gas generating lower portion A and a somewhat smaller carbide containing and gas storage upper portion 13. The upper end of the lower portion A may taper inwardly and upwardly so as to merge with the upper portion B which may be provided with a conical top C. In order to provide access to the interior of the generator the meeting portions of sections A and B may be respectively provided with separable flanges i3 and i2 suitably joined by conventional means such as a plurality of bolts l4, and appropriate hinges i5.

The upper section B may also be provided with a suitable compartment or chamber D within which the accessory equipment, with which such generators are usually provided, may be inclosed and protected by a suitable closure such as doors I6 and [8. The compartment D is preferably within the general outline of section B with which the doors i6 and I8 substantially conform. The generator may be further provided with conventional features such as a carbide charging door 20, gas outlet manifold 22, water filling plug 24, overflow plug 28, sludge agitator 28, residue or drain valve 38, anchoring eyelets 32, handles 34, and charging platform 36.

The upper portion of the interior of section B may be provided with a carbide hopper E having a downwardly tapering wall or bottom 33 with the upper portion or margin rigidly secured to the inner wall of section B by an impervious joint such as an autogenous weld. The lower end of the carbide hopper E may be provided with a suitable depending spout 453 having a carbide outlet opening 42 therein. For convenience in attaching adjacent accessories the spout 49 may be secured to the lower end of the carbide hopper by conventional means, but'to facilitate removal of the outlet the spout 46 is preferably secured to an annular hopper casting or ring 44 by suitable means such as a plurality of bolts 46, and the ring 44 may in turn be rigidly secured around a suitable opening in the bottom of the hopper by conventional means such as a weld 48. The lower portion of the spout 49 may be provided with a drip flange 5! and this flange may be provided with an interior annular groove 52 adjacent and below outlet 42 in which an annular compressible valve seat 54 of soft rubber or the like is removably secured by a supporting retainer plate 56 and an interfitting spring ring 58. The opening in the annular valve seat 54 may be of substantially the same size and substantially in alignment with the outlet opening 42 with which it cooperates and forms a part,

and the flow of carbide from within the hopper through the outlet opening may be controlled by a carbide valve 60 that seats on valve seat 54 and forms a fluid-tight joint through which no Water or moisture can enter the hopper and cause generation of gas when the valve is closed. This carbide valve may form a part of a carbide feed and gas pressure control mechanism F that may be detached from the generator as a unit.

The control mechanism unit F may include a pliable diaphragm 62 upon which the gas pres sure within the generator is balanced by one or more expanding springs such as 64 and 66. These springs may be compressed within a suitable housing as in operative relation with-the diaphragm which is operably connected with the carbide valve 60.

The housing 68 may be of any suitable shape and it may be mounted in any suitable position with respect to the generator, although it is preferably cylindrical with a closed end or bottom, and it is preferably mounted within an opening l!) in the outer wall of the generatorwith the closed bottom outside thereof. The housing may be secured ,to the generator by any suitable means, but it is preferably provided with an annular flange 72 which is secured around the central portion thereof by suitable means such as a weld l3 and this flange may be secured directly'to the generator casing. However, due to the thinness and curvature of the casing, it is preferably secured to the inner face of a reinforcing flange ring 74 that is secured to the margin of opening 10 outside the casing by suitable means such as an autogenous weld 76. The flange 12 may be detachably secured to flange ring 14 by conventional means such as a plurality of bolts 18, and the joint may be rendered gas tight by suitable means such as an interposed sealing gasket 80.

The inner end of housing 88 may be provided with an outwardly offset annular flange 82 secured thereto by an annular weld 83, and diaphragm 52 may be secured between this flange and an annular flange ring 84 by suitable means such as a plurality of bolts 86. The central portion of diaphragm 62 may be supported on the side facing the spring housing 68 by a diaphragm pressure plate 88 of suitable size and form located in recess 89 in flange 82. This diaphragm plate may be secured to the diaphragm by suitable means such as a diaphragm yoke 96 having a somewhat smaller shank 92 extending inwardand suitable openings at the center of diaphragm 62 and pressure plate 38, where a threaded portion is engaged by a suitable clamping nut 95 from which a reduced cylindrical portion extends inwardly a suitable distance into casing 68.

In order to materially increase the sensitivity and range of movement of diaphragm 62 to variations in pressure within the generator, two relatively long and limber pressure balancing

springs

64 and 66 may be employed in placeof a single relatively short and stiff spring such as those employed heretofore, and to conserve space and secure the necessary spring pressure on the diaphragm these springs may be oppositely coiled one within the other and compressed within casing 68 toa small fraction of their original length. The free length of these springs may be of the order of from two to four times their working length, which may be substantially the length of their containing casing.

Not only is the free length of these springs be integral with the spout 40, and the outer end provided with the above-mentioned operating handle I54. Between the cam I52 and the handle I54 the connecting shaft I56 may extend through a suitable opening in partition I60 which separates the carbide containing and gas storage chamber B from the accessory compartment D and also forms part of the outer casing of the generator, and this opening may be provided with or include a suitable stufiing box I62 to prevent the escape of gas from within the generator. In order to securely hold the carbide valve in closed position and also prevent the cam from being rotated to an unsafe position, the cam I52 may be provided with a suitable stop such as a projection I64 that extends outwardly from the closed end of the cam and arrests the closing movement when the valve is tightly closed.

During the operation of generators of this type the finer particles of carbide such as carbide dust may collect on the operating mechanism of the carbide valve and coact with the moisture within the generator, thereby forming a carbide sludge that interferes with the proper action of the relatively moving parts. Also, any variation from the correct relative location of the valve operating structure and the valve seat may cause improper operation. In this .generator both of these contingencies may be obviated by providing the interior mechanism with a combined carbide shield and locating plate I 66 that covers the operating mechanism and is secured at the inner margin to the under side of hopper casting 44 by a suitable number of the attaching bolts 46, and is secured at the outer margin to flange 82 of control unit F by a suitable number of the attaching bolts 86. This plate protects the operating mechanism from carbide and sludge and also maintains the carbide valve in correct operating relation with respect to the valve seat. Heretofore, during the operation of generators of this type, a portion of the feeding carbide collected on the carbide Valve supporting or operating structure, and then when the generator was placed in inoperative condition and moved, this carbide dropped into the water in the generator and caused undesirable generation of gas. In the present generator, this undesirable contingency has been overcome by providing the carbide valve operating mechanism with a feed lever I32 of which the portion in the path of the feeding carbide is curved or inclined downwardly so that the feeding carbide will not collect there on in an undesirable quantity.

When the valve operating mechanism of this generator becomes damaged or inoperative, its return to service is expedited by the unit construction which greatly facilitates field assembly and replacement. For example, the generator may be readily opened by removing bolts I4 and the interior mechanism rendered accessible by tipping the upper portion B backwardly on the hinges I until it comes to rest on the charging platform 36, as described in copending application of Maurice P. De Motte and Clarence H. Baker, Serial No. 739,731, filed August 14, 1934, and then by removing the bolts I8 and the shield I66, the entire carbide feed and pressure control assembly may be detached from the generator as a unit, and another similar unit in proper operating adjustment may be substituted. This feature greatly facilitates repairs and reduces the time that damaged or inoperative generators are out of service. In case the damage is to the operating structure outside the spring housing 68, this mechanism may also be removed as a self-contained unit by removing shield I66 and bolts 86 which releases the diaphragm, diaphragm ring, and other connected structure, which may be replaced by an operative unit.

When the carbide valve is closed and, preferably, locked in closed position, the generator may be charged and recharged in a well known manner. To start operation, the carbide valve is unlocked and permitted to remain open for short periods of time until sufficient gas has been generated to operate the automatic control after which the gas pressure will be automatically maintained until the carbide becomes exhausted.

In addition to the features specifically described and claimed herein, the generator may be provided with an inclosed compartment in which the accessory equipment is located within the general outline of the generator casing. The generator may also be provided with an improved interlocking mechanism by which the manual operating sequence of the accessory equipment is controlled when the generator is opened or recharged. These features are covered by the previously referred to copending application Serial No. 739,731. The generator may be further provided with an improved pressure regulator and filter which may be located in a new and useful position, and this feature is covered by my copending application Serial No. 738,099, filed August 2, 1934. The invention herein is closely related to the invention which is shown, described, and claimed in my continuation-in-part application Serial No. 154,159 filed July 17. 1937.

The structure, form, and relative arrangement, of the features described may be difierent from that shown, and the materials employed may be those well known in the art or those similar or equivalent to the ones defined, without departing from the useful features of the invention of which the present embodiment is but one example of a general structure by which the useful results of the invention are obtained.

I claim:

1. An acetylene generator comprising an outer casing adapted to contain a partial filling of water; a carbide hopper in the upper portion of said casing having an outlet opening above the surface of said water; an annular drip flange rigidly secured to said hopper around and below said outlet opening, said flange being provided with an interior annular recess; an annular valve seat of relatively soft rubber within said flange around said outlet opening and backed up throughout the extent of its annular surface by a rigid support; means for securing said valve seat within said drip flange comprising a relatively rigid annular retaining plate within said drip flange below said valve seat, and a spring ring between said plate and the lower wall of said recess; a movable mushroom-type carbide valve adapted to cooperate with said valve seat and form a fluid-tight closure for said outlet; and means for operating said valve to feed carbide from said hopper into said Water.

2. An acetylene generator comprising a carmuch greater with. respect to their Working length than springs employed in devices of this kind heretofore, but the diameter of the. springs is much greater with respect to their working length, and the diameter or sectional area of the spring material is much less in proportion to the diameter of the springs. long length and small size of the spring material, the sensitivity and range of movement of these springs in response to a given change in pressure upon the diaphragm is much greater than that of the springs employed heretofore. Also, two springs in parallel are more sensitive, more reliable, more uniform, and deteriorate less in strength, than a single spring of equivalent strength or stiffness.

In prior devices of this type, the free length of the spring was usually less than the interior length of the casing in which it was housed, and therefore field assembly was not a problem. If the. present springs were simply substituted for 'those employed heretofore, field assembly would be extremely difficult due to the lack of suitable means for releasing and recompressing the springs. Therefore, these springs are compressed to a small fraction of their free length and secured between suitably attached relatively movable spring-pressure plates so that the assembly, together with a suitable tension-adjusting screw if desirable, may be removed from or inserted in the'apparatus as a unit. Also, this assembly is suitable for use with other spring" controlled apparatus.

In the complete assembly, as shown by the drawing, the

springs

64 and 66 may be secured in housing 68 under a suitable degree of compression between an outer spring pressure plate 98 and an inner spring pressure plate I00, and these spring pressure plates may be secured together by suitable means such as a plurality of bolts or screws I02. Any suitable number of these bolts may be employed, such as three for example, and they may extend between the, pressure plates within the springs. In order to provide relative movement between the pressure plates, each of the bolts I02 may be rigidly secured in a suitable opening in one pressure-plate, such as inner plate I00, by conventional means such as interfitting threads, and extend'locsely through a suitable opening in the other pressure plate, such as outer plate 98, outside of which it may be provided with a suitable enlargement such as a head I04.

' 1 The inner pressure plate I may be positioned axially and restrained from transverse movement to a position Where it may come'into undesirable frictional engagement with housing 68 by providing the central portion with a suitable opening I05 that fits loosely without undesirable lost motion on the inner end of shank 92. Also, the pressure of

springs

64 and 66 may be transmitted to the diaphragm by providing the inner side of diaphragm pressure plate 80 with an annular boss or a plurality of lugs I06 arranged in a circular row around shank 92 with their outer ends in contact with spring pressure plate I03.

In assemblies of this type, it has been the custom heretofore to thread a manually adjustable screw in the outer end of the spring housing to vary the position of the outer spring plate and adjust the operating tension of the diaphragm balancing spring. Such adjusting screws naturally project various distances according to their position of adjustment, and therefore they were left exposed to injury. To obw'ate this danger Therefore, due' to the of injury to the adjusting screw, the outer adjustable spring pressure plate 98 may be provided with a central opening I08 in threaded engagement with a stationary adjusting screw IIO that extends outwardly through a suitable opening in the closed end of housing 68 into an outer annular boss I I2 where the outer end is provided with a contour such as a square II4 suitable for engagement by an appropriate key or wrench. The outer end of this screw may be further protected by a suitable cap IIB which may be threaded or otherwise secured to the outside of boss H2.

The boss II2 may be integral with the spring housing 68 or, to facilitate manufacture, it may be a separate element secured in a suitable opening in the outer end of housing 68 by conventional means such as an autogenous weld I I8.

To facilitate ease of adjustment, screw I I0. may be provided with an integral thrust collar I within housing 68 that rests on a suitable bearing such as a ball thrust bearing I24 located in a suitable recess in the inner surface of the housing 68 or the inserted boss H2, and to obviate disengagement of ad usting screw H0 and spring plate 98 the inner end of this screw may be provided with a suitable stop such as a washer I26 which may be secured to the end of the screw by suitable means such as a bolt I28. Also, adjustment may be further facilitated by providing casing 68 with a fixed rod or stud I30 that extends through a suitable eccentric opening in spring plate 98 and holds it against rotation when the adjusting screw is moved. To further facilitate operation of the mechanism in casing 68, this mechanism'may be lubricated with suitable material such as light cup greasel Q The carbide valve 60 may be carried by mechanism suitably connected with the diaphragm such as a. feed lever I32 of. suitable form having means such as a slot in the outer end in which the carbide valve is operably secured by a suitable means such as a pin I34. This feed lever may be hinged on a suitable hinge pin I36 extending across an appropriate slot formed by lugs I38 of a feed lever support I40 that may be integral with flange ring 84. The carbide feed lever may be connected with the diaphragm by suitable means such as a connecting member or link I42 having one end secured on a suitable pin I44 in diaphragm yoke 90, and the other end provided with a slot I46-that slidingly engages .a pin I48 fixed in feed lever I3 2. The pin I48 and slot I46 in link I42 comprise a lost motion connection which provides suitable relative movement between the diaphragm and the feed lever so that the carbide valve may be manually. closed without placing an objectionable strain'on the diaphragm and associated valve operating'structure.

For the purpose of holding the carbide valve closed when desirable, such as when the generator is moved or when it is recharged, suitable means may be provided for operating the valve manually. include a valve closing arm or looking lever I50 integral with feed lever I32 and in operative relation with a suitable cam I52 operably conected with a suitable manually movable member such as handle I54 which is preferably located outside the generator casing within the accessory compartment D.

The cam I52 may be rigidly secured by suitable means such as a conventional pin to an appropriate shaft I56 having the inner end thereof This manual operating means may I suitably journaled in a bearing I58, which may 7 operably connecting said automatic means with said valve support including a limited lost-motion connection providing sufficient relative movement between said automatic means and said valve support so that said valve may be manually closed without placing an objectionable strain on said automatic means, but still enabling said automatic means to effect positive opening of said carbide valve when said manually closing means is moved to an ineffective position.

3. An acetylene generator comprising a carbide hopper provided with a carbide outlet; a carbide feed valve; a suitably mounted lever for supporting said carbide feed valve in operative relation to said carbide outlet; means comprising a manually operable cam in operative relation with said lever for closing said carbide valve; pressure responsive means suitably mounted adjacent said lever for closing said carbide valve; and means for operatively connecting said pressure responsive means with said lever comprising a link having a slot therein that cooperates with a suitable supporting pin and provides sufficient relative movement between said pressure responsive means and said lever so that said carbide valve may be manually closed without placing an objectionable strain on said pressure responsive means, but still enabling said automatic means to effect positive opening of said carbide valve when said manually closing means is moved to an ineffective position.

4. An acetylene generator comprising an outer casing having an opening in the lateral wall thereof; a carbide hopper in the upper portion of said casing having an outlet adjacent the opening in said casing; means for controlling the feed of carbide from said outlet comprising a carbide feed valve and automatic valve operating mechanism operatively connected into a self-contained operative unit; and means for removably securing said unit in the opening within said casing and with said carbide feed valve in operative relation with the carbide outlet of said carbide hopper.

5. An acetylene generator comprising an outer casing forming a gas chamber and having an open compartment in one side within the general outline thereof; a carbide hopper within the upper portion of said casing having a carbide outlet; a carbide valve for controlling the feed of carbide from said outlet; a suitably mounted lever for supporting said valve in operative relation with said outlet; and means for manually closing said valve comprising a cam within said generator in operative relation with said lever, an operating handle outside of said casing within said compartment, and means for operatively connecting said cam with said handle.

6. An acetylene generator comprising an outer casing; a carbide hopper within the upper portion of said casing having a depending carbide outlet; a carbide feed valve for controlling the feed of carbide from said outlet; valve operating mechanism secured to said casing substantially entirely within said generator adjacent to but spaced from said outlet; suitable mechanism for operatively connecting said valve operating mechanism with said valve; and a cover plate suitably secured to said operating mechanism and said hopper above said connecting mechanism for protecting said connecting mechanism from falling carbide dust and also maintaining a correctly spaced operative relation between said valve and said outlet.

7. An acetylene generator comprising an outer casing; a carbide hopper within said casing having an outlet; a carbide valve for controlling the feed of carbide from said outlet; means for operatively moving said valve comprising a diaphragm responsive to the pressure within said generator; means for supporting said diaphragm comprising a spring housing in operative relation therewith; and means for balancing the gas pressure upon said diaphragm comprising a plurality of springs compressed within said housing to a small portion of their free length and capable of being inserted within or removed from said housing as a unitary assembly and without relieving said initial compression.

8. An acetylene generator comprising a carbide feed valve; means for operatively moving said valve comprising a diaphragm responsive to the pressure within said generator; means for supporting said diaphragm comprising a spring housing operatively secured thereto and substantially entirely within said generator; means forbalancing the pressure upon said diaphragm comprising a suitable spring within said housing; means for mounting said spring in said housing comprising an adjustable spring pressure plate; and means for adjusting the tension of said spring comprising a stationary adjusting screw rotatively mounted in said housing in threaded engagement with said pressure plate. I

9. An acetylene generator comprising a carbide feed valve; means for operatively moving said valve comprising a diaphragm responsive to the pressure within said generator; means for supporting said diaphragm comprising a spring housing operatively secured thereto; means for balancing the pressure upon said diaphragm comprising a suitable spring within said housing; means for mounting said spring within said housing comprising an adjustable spring pressure plate; means for adjusting the tension of said spring comprising a centrally collared stationary adjusting screw rotatively mounted in said housing in threaded engagement with said pressure plate; and means for facilitating the easy movement of said adjusting screw comprising a ball thrust bearing between the collared portion of said screw and the inner surface of said housing. v

1%). An acetylene generator comprising an outer casing provided with a lateral opening; a carbide hopper within said casing having a depending outlet adjacent said opening; means for controlling the flow of carbide from said outlet comprising a carbide valve in operative relation with said opening; means for operatively moving said.

valve comprising a diaphragm responsive to the pressure within said generator; means for supporting said diaphragm comprising a housing suitably mounted within said opening with a portion thereof outside of said casing provided with an annular boss; means for balancing the pressure upon said diaphragm comprising a spring suitably mounted in said housing in operative relation with said diaphragm; means for adjusting the operating tension of said spring comprising a stationary adjusting screw rotatively mounted within said housing in operative relation with said spring and provided with an operable portion extending through said casing into the opening in said annular boss; and means for protecting said screw from exposure to damage comprising a cap suitably secured to said boss over the operable portion of said screw.

11. An acetylene generator comprising a carbide hopper having an outlet; means for controlling the flow of carbide from said outlet comprising a carbide feed valve in operative relation therewith; means for operatively moving said valve comprising a diaphragm responsive to the pressure within said generator; means for supporting said diaphragm comprising a housing suitably secured to the outer margin thereof; means for supporting the central portion of said diaphragm against the generator pressure exerted thereon comprising a diaphragm pressure plate suitably secured to the central portion of said diaphragm within said housing; means forbalancing the pressure upon said diaphragm comprising a partially compressed spring within said housing; means for operatively mounting said spring within said housing comprising a movable spring pressure plate in operative relation with one end of said spring and bearing on said diaphragm pressure plate, and an adjustable spring pressure plate in operative relation with the other end of said spring; and means connecting said spring pressure plates to limit the expansion of said spring to substantially the length of said housing.

12. An acetylene generator comprising an outer casing provided with a lateral opening; a carbide hopper within said casing having a depending outlet adjacent said opening; a carbide valve for controlling the flow of carbide from said outlet; valve operating means comprising a spring casing mounted within said lateral opening and provided with an annular flange around the inner end thereof; a pressure responsive diaphragm on said flange; means for securing .said diaphragm to said flange comprising a flange ring provided with a feed lever support; a suitable spring within said housing for balancing the pressure on said diaphragm; means for supporting said carbide valve in operative relation with said outlet comprising a feed lever operatively mounted on said feed lever support; and means I01 operably connecting said diaphragm to said feed lever.

13. A spring assembly adapted to be unitarily inserted within or removed from a housing of a spring controlled apparatus comprising a plurality of spring pressure plates in opposed relation; a plurality of springs compressed between said spring pressure plates to a small portion of their free length; and means for connecting said pressure plates comprising a plurality of connecting members rigidly secured to one of said pressure plates but movable with respect to the other of said pressure plates; adjustable means for further compressing said springs to a length less than that of said connecting members,

14. A spring assembly adapted to be unitarily inserted within or removed from a housing of a spring controlled apparatus comprising a plurality of reversely coiled springs located one within the other and compressed to a small portion of their free length; a movable spring pressure plate in operative relation with one end of said springs and provided with means by which it may be operatively connected to said apparatus; an adjustable spring pressure plate in operative relation with the other end of said springs and provided with an opening; an adjusting member movably mounted in said opening and provided with means by which'it may be operatively connected to said apparatus; and means for securing said spring pressure plates against separation comprising a plurality of connecting members of which each is rigidly secured to one of said spring pressure plates and movably secured to the other of said pressure plates so that said springs may be further compressed during operation. 7

15. An acetylene gas generator comprising a lower housing adapted to contain water; a substantially cylindrical upper housing in communicative registry with said lower housing and constructed and arranged to provide a gas 001-- lecting chamber and a compartment independent of said chamber within the continuity of the outline of said upper housing; a carbide hopper and a feed-valve, both within said gas chamber; pressure responsive means located substantially entirely within the upper housing in oper ative association with said feed-valve; and means for manually closing said feed-valve located within said upper housing and extending into said compartment.

16. An acetylene generator comprising a lower section adapted to contain water; an upper section having an opening in the lateral wall thereof, said section containi g a carbide hopper having an outlet adjacent vto said opening in said lateral wall of said upper section; a carbide feed valve associated with said hopper outlet; and a spring-balanced pressure-responsive control device adapted to be removably secured substantially wholly within the opening in the lateral wall of said upper section in operative association with said feed valve, said device including a housing and a spring assembly adapted to be positioned within or removed from said housing as a unitary assembly.

MAURICE P. DE MOTTE.