Flame safety and open lamp
US 1323618 A
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T. M..CHANCE. FLAME SAFETY AND OPEN LAMP.
APPLICATION FILED APR. 26. IQII.
1,.i:23,618.1 Patented Den. 2,1919.
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LM; CHANCE. FLAME SAFETY AND,0PEN LAMP.
APPLICATION FILED APR. 26| 1917;
` Patented, Dec. 2,1919.
3 SHEETS-SHEET 2.
ravi FIL-LH I W/TNESSESI v Y l (i T. M. CHANCE.
FLAME SAFETY AND0PEN LAMP.
APPucAnoN man Amma. um.
1923,61 j Patented Dec.2,1919.
AWT@ W W/ TNESSES: n /N VEN TOR burner.
UNEP AlY srarns THOMAS 1VI. CHANCE, 0F PHILADELPHIA, PENNSYLVANIA.
FLAME SAFETY AND LAMP.
Specification of Letters Patent.
Patented Dee. 2, 191e.
Application led April 26, 1917. Serial No. 164,675.
To all whom t may concern." Y
Be it known that I, THOMAS M. CHANGE,
a citizen of the United States, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented a certain new and useful Improvement in Flame Safety and Open Lamps, of which the following is a specification. The object of my invention is to provide an improved type of flame safety lamp that will project a portion of the light emitted by the flame into the space above, and in some cases below, said lamp. A further object of my invention is to provide a means for increasing the efficiency of the burner, in'thosetypes of lamps employing a reigniting type of burner in connection with a gaseous fuel. Another object of my invention is to provide an improved acetylene generator whereby a safety lamp may Vbe constructed that will eliminate the objectionable features hitherto encountered in lamps of this type.
To attain these ends I constructthe lamp to operate in the manner shown by the accompanying drawings, and described Ain detail in the following specification.A It will be understood, however, that I do not limit myself to the particular constructions shown herein, but that these types may be Widely varied without departing from the spirit of my invention, and that the drawings shown herein are diagrammatic representations of the general association ofrelements necessary tothe operation of my invention.
The drawing, Figure I, is a diagrammatic vertical cross-section of an acetylene safety lamp adapted to carry lout my invention. Fig. II is a similar cross-section of a lamp employing a dierent arrangement of reflectors and generator and a dierent type of Fig. III is Van enlarged vertical crossesection showing another type of reigniting burner. FigjI-V is a partial vertical cross-section illustrating-an improved type of combustion chamber. Like numbers in the several drawings indicate like parts.
In the drawing Pig.V I, 1 indicates a Water chamber provided Vwith filling opening 2,
in this case iitted with a ball valve, and pressure escape pipe 3. The calcium carbid container 4 is fitted with water feed tube 5, and
is provided with a water sealed cover 6, said cover 6 screwing into water chamber 1 and supporting container 4 by screw thread 7.
Said water chamber 1 carries valve and water-feed valve stem 8 in a screw thread in the base of said chamber. Said stem 8 is provided with a conical valve face at its `upper end, adapted to close communication V between container 4 and the burner,-in this case a single jet steatite burner 9 provided with self-contained reigniting prongs 10 and shield 11,mounted on cover 6. Said stem 8 is enlarged near the operating screw thread at its lower end, said enlargement nearly filling` feed tube 5 and providing a restricted water feed to the carbid contained in 4. This enlargement may be provided witha conical valve Vseat at its lower end to prevent leakage of water past the operating screw thread on said stem when said stem is screwed to its lowermost position. The stem S `is also provided with an operating head at *its lower extremity. A filter 12 is held in place in the top of cover 6 by filter support 13, said support 13 housing over a tube 14 surrounding` valve stem 8. Said tube 14 slips into feed tube 5 when container 4 is being filled with carbid (preventing the falling of carbid into said tube 5), but is lifted Vout of tube 5 by the enlargement on valve stem 8 when container 4 and cover 6 are screwed into place in water chamber 1.
The combustion chamber, or lamp top, is composed of bonnet 15, provided with standards 16 connecting said bonnet with screw ring 17. Said screw ring may be provided with a locking device 18, for locking said lamp top to the gas generator, the locking device being in thisv case shown as of the lead rivet, slip ring type. Said screw ring 17 is provided with reflecting element 19, the function of which is further described in this specification.V Glass-ring 2O screws into screw ring 17 and supports a horizontal gauze 21 carrying outer glass 22 and glass chimney 23, which in turn support horizontal gauze 24 fitted with metal chimney 25, outer gauze 26 and inner gauze 27 The admission of air for combustion is secured through slots 28 in the wall of bonnet 15`and ,gaskets 29 are placed between glass 22 and ganzes 21 and 24 to insure a gas-tight fit.
y from the flame.
1, feed tube 5 slipping down over valve stem 8 and tube 14 being raised by the enlargement on said stem. TWater is now introduced through llingopening 2 and, the valve on' stem 8 being open, generation of .acetylene commences, the resulting gas passing thrbugh filter 12, and issuing at the orifice of burner The lamp may now be lighted and the lamp top, assembled as shown in Fig. I, is screwed in place on 'water chamber 1. A lead rivet is inserted in locking device 18 and the rivet upset, thus isolating the entire internal mechanism Vof the lamp from the exterior.
As the lamp gradually heats up the air for combustion is heated by passing downward through the annular space between the interior glass chimney 23 and exterior glass 22, both of these glasses becoming very warm due to heat radiated and conducted Shield 11 likewise becomes heated and, acting as a reflective element, prevents excessive dissipation of heat from the reigniting prongs 10 on burner 9.
If the lamp be now subjected to the concussion due to shot-ring or other rise in atmospheric pressure, the jet of gas issuing from the orifice of burner 9 will be temporarily arrested, but immediately said jet is reestablished, after the passing cf the concussive wave, the flame is also restablished by some portion of the mixture of acetylene `and air reaching the reigniting prongs 10 duringsaid restablishm'ent of the jet.
i The function of the double glass type of combustion chamber is twofold. in the rst place it assists materially in steadying the lamp flame from the eifect of exterior air currents, etc., tends to increase the etliciency of combustion by pre-heating the air supply and prevents the chimney effect commonly encountered with under-feed lamps, such as the Wolf lamp, when the lamp is introduced into atmospheres containing considerable percentages of liredamp or combustible gas. In the second place it greatly increases the safety of the lamp inasmuch as a lamp so constructed comprises virtually two lamps in one. That is, if the exterior glass be broken, or even completely removed, the lamp flame is still isolated by horizontal gauze 21, inner chimney 23, upperhorizontal gauze 24 and exterior and interior gauzes 26 and 27 respectively. Thus it will be readily seen that this type of lamp is more safe for use in locations where the outer glass may become accidentally fractured, as
such fracture of the glass in the ordi-i nary type of lamp may result in immediate passage of the flame to the exterior should the exterior atmosphere be inflammable. A further advantage ofthis conf struction is that the inner glass is virtually spring-supported, horizontal ganzes 2l and 211 acting as resilient cushions, and l have' in inflammable atmospheres, as there are four ganzes which must be passed on the inlet side of the lamp before the lamp can fire the exterior atmosphere, andin lamps fitted with a chimney, such in lamps of the Muessler type, exterior ignitions are nearly always produced by passage of the flame on the inlet side of the lamp, since the products of combustion in the chimney generally prevent ignitions down chimney. While in the construction herein shown there are but two ganzes isolating the discharge of the lamp from the exterior, it will thus be seen that the cushion of dea-d gases in chimney will assist in preventing ignition on the discharge side.` The chimney alsd assists in the vdraft of the lamp.
The reflecting element 19 serves to project a portion of the rays of light emitted from the flame in a roughly conical path upward, (the approximate path of one such ray being shown by the dot and dash line A-L) andthereby provides an illuminated area immediately above the lamp, thus enabling the miner using` the lamp to make a careful inspection of the condition, of the roof or other space above him. Such inspection h as hitherto been practically impossible of ac-Y complishment and it is a well known fact that in many districts more accidents have resulted from failure to properly inspect` the roof after safety lamps were introduced, than were formerly caused by ignitions of gas, due to the use of open lamps. The only wayin which the roof can be inspected `with safety lamps as at present constructed is by tilting the lamp, andv while such tilting could be practised to a moderate degree in lamps burning acetylene or other gas under pressure, it is fatal tothe operation of the common t e of oil burnin()` safet lam s as it results in immediate smoking of the glass. It should be noted that the light projected by the refiecting element need not necessarily remove any considerable amount of light from the fluxemitted'by the flame i.
in a horizontal directioinfor said element can readilyvbe designed to make use of light that would largely be lost by-abs'orptionin said CIK
be used in the upper portion of said bonnet, as shown in Fig; Il, should it be desired to illuminate the floor below'the lamp.
The method of operation of the generator shown in Fig. I is similar to that commonly Vknown as the contact method, that is, the
water is introduced near the bottom of the carbid, the supply of water depending on the relation between the gas and water pressure; and the resultant excessive heating encountered in drip generators is lessened. Should the slacked carbid form a' crust about the orifice of the water feed, this may beeifectively broken up and normal conditions restablished by rotating the valve stem 8 by means of the milled head on the lower end. This rotation will raise the valve stem up and down in feed tube 5 and perform the function commonly known as raking in the small generators now used for mine lighting. It will be noted that the valve Y stem has some play before encountering the conical seat in cover 6 so that a number of turns can be given in this raking process before shutting the gas supply olf.
The function of water-sealed cover 6 is the saine as that commonly performed by the Vcover of the belltype of generator, that is,
a water seal is provided to prevent the escape of gas, but with this important addition, that mechanica-l means are provided for preventing free flow Yof water between the water chamber and the interior of carbid `container 1, should the generator' be overturned. ln the drawing Fig. l, such flow is prevented by means of screw thread 7, said screw thread', while not necessarily forming a gas-tight fit, providing a greatly restricted frictional resistance so that free escape of the gas is prevented and the 'flooding ofthe generator with water, should the lamp be turned on its side, eliminated. This trouble due to flooding of the lamp just referred to would be inherent in rall types of watersealed generator in common use and would effectually prevent the use of such generators in lamps of this kind. l have found, however, that by the addition of a mechanical resistance to the hydraulic seal, a generator the generator is available that possesses the paramount advantage of gas-tightness-a 'condition thatcould never be absolutely insured in lamps employing a gasket alone for the sealing of lcoupled with absolute portability, that is, the generator can be overturned, swung from the hand or in other ways mistreated without seriously 'affecting Vits operation.` ltinight be `noted herethat the impossibility of insuring gas-'tightness in lampsusing gaskets for the sealing of the generator, has so militated against the use of this type of lamp that the acetylene safety lamp as heretofore constructed has not been lpermitted in any of the principal mining districts ofthe world.`
Inv the drawing Fig. 11 the generator is similar in construction to that shown in Fig. I, and need not be further described except to call attention to the fact `that the mechanical resistance, shown in Fic'. l as screw thread 7 is here shown as a gasket 7 placed between the carbid container Ll and cover 6, this gasket being placed in compression when cover G is screwed down on the carbid container 4, and also that movable tube lil is replaced by a stationary perforated tube 14. 1t will of course be understood that this gasket could be placed at the lower portion of carbid container il, and thus immersed in water, instead of in the position shown.
The burner 9A in this drawing Fig. Il is shown as a two-jet burner fitted with a wire reignitiiig coil 10 partially surrounded by shield l1. The reigniter in this case is heated by the heat radiated from both flames and performs the same function as reigniting'prongs 10 of the burner shown in Fig. i.
The combustion chamber or lamp top is in this case shown as of the YV olf type and is provided with annular top and bottom reflecting elements 19 and 19a. The function of reflecting element 19 has been fully de scribed in the description of the drawing Fig. 1. That of 19a is similar, with the difference that the light rays reflected by 19 are directed upward toward the roof while those reected by 19'd are directed toward the space below the lamp, the approximate path of one such ray being shown by the dot and dash line BB.
lt should be noted, however, that the rejecting element 191 is not designed to perirni the saine functions as that of the reflectors commonly used in the .so-called porch type of safety lamp and that its size should never be so great as to materially cut off the upward rays reflected by element- 19. In other words, the function of element 19u is in all cases subordinate to that of element 19, as inspection of the roof is generally of far greater importance than that of the floor. The light rays indicated bythe dot and dash lines A- anclB-B in the several drawings are roughlyl approximate as no allowance has been made for refraction due to the exterior shield for preventing loss of heat from Ythe reigniting elen'lent. ln this case the burner 9, shown as of the single liet type` isprovided with helical coil l0 of nichel CIK maximum quantity of the heat received by` it from the lamp flame and reigniting element, to said lamp flame and reigniting element, and at the same time to lose by radiation and conduction a minimum quantity of heat. It will of course be understood that the function of the reigniting element is similar to that described in the drawings Figs. I and II.
I have found that by the use of a heat .insulating device such as the shield 1l in the drawing Fig. III, a reigniting burner can be successfully operated with a reigniting element that would operate poorly, if at all, when not provided with such a shield. As any light losses of the flame, due to the use of a reigniting element, are largely a function of the mass required by said element and of the proximity of said element to the flame, it will be clear that a device such as the shield ll which permits the use of reigniters of less mass, and placed farther from the flame, than would otherwise be possible, is exceedingly advantageous in increasing the efficiency of the lamp as a whole. The shield also performs another important function in that it prevents accidental breakage or deformation of the reigniting element when the lamp is 'being han dled during cleaning, etc.
The drawing Fig. IV illustrates a lamp of similar construction to that shown in Fig. I with the exception that the lamp top,
or combustion chamber, is of different construction. Said drawing need not be further described, therefore, except 'in so far as may be required for understanding the operation of this type of combustion chamber.
In this drawing Fig. IV the glass ring support 20 supports a plate 21 carrying tube 21a, said plate 21 supports outer glass 22, glass chimney 23 and upper plate 2l carrying tube 24 sliding over tube 21a. Plate 24 carries chimney 25, outer gauze 26 and inner gauze 27 in the same manner that gauze 24 supports these elements in the drawing Fig. I.
The function of the plates 21 and 24.` and tubes 21a and 24a is similarto that performed by ganzes 21 and 24 of the drawing Fig. I. The air for admission passes downward through these plates and tubes and is isolated from. the exterior atmosphere, and also from the annular space between the glass 22 and chimney 23. I-Ience the lamp flame is doubly isolated from the exterior atmosphere, as in the drawing Fig. I, and breakage of the exterior glass alone will not cause passage of llame to the exterior. The incoming air will be pre-heated by passing downward through tubes 21nu and 24" and these tubes will ofcourse be of vsuch cross-sectional area (or a plurality of such tubes will be used) as to insure sulficient air supply for the proper combustion of the flame. The advantage of this method of construction is that it renders impossible an ascending current of air and a descending current of air in the tubes at the same time, whereas this phenomena might possibly occur in the annular space between the glasses in the double glass type of lamp, such as shown in Fig. I. rIhe Vresult achieved is parallel. to that reached in the Gray type of lamp employing exterior tubes for air admission.
To insure the same degree of gauze protection as that shown in F ig. I, it will be understood that one or more ganzes may be placed within these tubes, and also that the tubes should be such a sliding fit over one another as to eliminate the possibility of firing the exterior atmosphere by a leak between the walls of the tubes. The tube 24Ea may advantageously support va reflecting element 24J for projecting thelight rays horizontally, as this tube will of course cut off a certain amount of light and this disadvantage may be thus counteracted. It should benoted thatV this reflecting element would be acting in` an absolutely dead atmosphere between theouter and inner chimneys and could therefore be kept clean for comparatively long periods of time.
The use of double glass lchimneys with double gauze protection in oil burning safety lamps is known, and has previously been practised in lamps of the Muessler type, but without successful cormnercialV result, as the sooting of the interior glass by the oil-fed flame was foundcertain to occur whenever the lamps were built with glasses ItV of a size that was practically feasible. will of course be seen that with a fuel such as acetylene this trouble will not be encountered, and I have found it possible to` operate lamps of this type for periods conl siderably in excess of 100 hours without cleaning the ganzes orglasses7 as under all proper operating conditions soot is not deposited by the combustion of the flame.
It will of course be understood that the reflecting elements of the typel herein described may readily be Vused with lampsV burning liquid fuels, and `of the types in common use, and the scope of this Vinvention is not limited to lamps of the gaseous fuel type. It should be pointed eut, however, that the low unit illumination of liq'- uid fuel safety lamps does not vproduce a roof or floor illumination comparableV to that possible with the acetylene type df lamp. Y
It will be understood that any type Vof more constant head of water yduring opera` tion than would be the case were a chamber of uniform cross-section employed, and while in no way essential-to the operation of my invention, I have found it to be an advantageous type of construction.
The functions of the regniting burner 9 are fully described in the U. S. `Patent 1,198,006 to Thomas M. Chance, and Aneed not be further described here.
It will be understood that the type of generator and shielded reigniting burner herein described may be used with lamps that do not require foraminous or other means for preventing exterior ignitions, suoli as in ordinary open lights, `and that the use of the type of generator and shielded burner in open lamps is entirely within the scope of my invention.
It will be understood that should excessive' generation of acetylene occur, the excess gas will blow back through the water in chamber 1 and escape to the exterior atmosphere by means of escape pipe 3. Should the lamp be extinguished by closing the gas valve carried on stem 8, the pressure in the generator, after building up to, or above, the operating head, will be relieved in the above manner, hence as soon as after-generation ceases further generation of fresh gas will stop until the gas valve is again opened, permitting the pressure in said generator to fall and fresh water to enter.
The type of mechanical resistance to be used in a water-sealed generator of the kind described herein may be greatly varied, the use of a gasket or screw thread being typical examples of a large class of structures that may be used for reaching the same end. It should be pointed out, however, that Whether a separate member, such as a gasket or screw thread, be used, or whether the cover and carbid container be forced together by a Vclose t, as for example, in a manner simr lar to the lid of a tin canister, the mechanical resistance so produced must be suiiicientto prevent the flooding of the generator when the lamp is overturned, and also to prevent the water feed working with a higher capillary resistance than the mechanical resistance employed in the water seal. I have found that under certain conditions a continuous over-generation of gas appears to'be produced if the water feedbe assisted by a high capillary resistance and the water seal is not provided with suhcient mechanical resistance. It will be understood 4that by the term mechanical resistance .where used 1n the speciication and claims hereof, is meant any organism acting in conjunction with a water-seal which will so restrict or prevent the free flow of water from the water chamber to the interior of the generator as to attain the ends just described.
The term foraminous in the claims and specificationhereof is intended to include materials with perforations, apertures or channels through which air may freely pass, but which are too small to permit the propagation of combustion, Vand I have used the word foraminous to designate materials containing such holes, aperturesor channels. The term glass in the claims land specification hereof is intended to mean any transparent refractory material.
It will also be understood that my invention is not confined to the operation of portable lamp structures, but may be equally well employed with stationary lamps.
Having described my invention I claim:
1. An improved safety lamp comprising in combination a source of combustible gaseous fuel, a reigniting burner adapted to utilize said fuel, a reflecting shield for the insulation of the reigniting element of said burner, and means for preventing the propagation of said flame to the exterior atmosphere.
2. An improved flame lamp comprisingin `combination an acetylene generator, a reigsigned my name at Philadelphia, Pennsylvania, this 25 day of April 1917.
THOMAS M. CHANCE.
H. M. CHANCE, CARL K. SCHULZE.