Apparatus for indicating the presence of inflammable vapors or gases

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May 14, 1940. HT. RINGROSE 2,201,055 APPARATUS FOR INDICATING THE P RESENOE 0F INFLAMHABLE VAPORS OR GASES Filed July 27, 1937 4 Sheets-Sheet 1 A 4a 45 B 1o 5%: D 7- AWL? I, Q 6 ' 15 21 j? 9 /4 2a 4 2 b '3 25 Henry 7? @Mgrosa May 14, 1940. H. T. RINGROSE 2,201,055 APPARATUS FOR INDICATING THE PRESENCE OF INFLAMMABLE VAPORS 0R GASES Filed July 2'7, 1937 4 Sheets-Sheet 2 z 2 zzuz nial. Henry 7? P51 1052 y 14, 1940- H. T. RINGROSE 2,201,055 APPARATUS FOR INDICATING THE PRESENCE OF INFLAMMABLE VAPORS 0R GASES Filed July 27, 1957 4 Sheets-Sheet '3 Hen/y I fzjr g fose H. "r. RINGROSE 2,201,055 Filed July 27, 1957 4 Sheets-Sheet 4, May 14, 1940; APPARATUS FOR mncnme m". rnssnncn 0F mnmuasm VAPORS on GASES frzuzn Zbr Henry T. [Pi/gran, darflew Patented May 14, 1940 uuirsn crates APPARATUS FOR INDICATING THE PRES- ENCE OF INFLAMMABLE VAPORS 0R GASES Henry Thomas Ringrose, West Park, Leeds, - England Application July 27, 1937, Serial No. 156,003 In Great Britain August 1, 1936 2 Claims. age of such inflammable vapors or gases reaches a predetermined figure. In this type of apparatus it has been proposed to provide in the porous vessel an incandescent filament for combustion of the diflused or aspi rated gases, and to connect said filament in series with the lamp circuit through contacts con- 0 trolled by a collapsible diaphragm connected with the interior of the porous vessel. According to the present invention, the diaphragm controlled contacts are shunted by a resistance of such a value that when the contacts are broken, sufiicient current is passed by said resistance as to cause the lamp to glow or to give an appreciably less illumination than normally. This dimming of the light from the lamp indicates the presence of inflammable vapors or gases in excess of the predetermined quantity or proportion, whilst the maintenance of a dimmed light through the provision of the resistance across the diaphragm controlled contacts in the lamp circuit, ensures sufficient light for the miner to see his way out of the danger zone. In order to enable the apparatus to be tested, means may be provided for delaying the equalisation of pressures between the interior of the diaphragm and that of the porous vessel, and such provision may be in the form of a restricted passage or orifice in the conduit between the diaphragm and vessel, said restricted passage being controlled by a closure which will permit a very slow leakage. Thus when the lamp and the filament in the porous vessel are first turned on, the lamp will give full luminosity and the interior of the porous vessel will be heated up. If now the lamp and filament be turned off the loss of heat in the porous vessel will create a big vacuum and break the contacts, and when the lamp is again turned on the current will pass through the resistance until the vacuum is destroyed and the circuit again made, thereby giving a dimmed light prior to full illumination and indicating that the filament and lamp circuit are in order. The greater the restriction or bailling efiect between the porous vessel and diaphragm the greater will be the period of operation of the dimmed light resulting from the delayed equalisation of pressures. in order that the invention may be clearly understood and readily carried into eilect, the will now be more fully described with reference to and by the aid of the embodiment-illustrated in the accompanying drawings, wherein- Figures 1 and 2 illustrate in vertical sectional elevations taken at right angles, the upper part or a miners lamp incorporating an inflammable gas detector or indicator in accordance with the invention. Figure 3 is a plan view taken on the line A. B. of Figure 1 with the lamp glass and associated top structure of the lamp removed. Figure 4 is a plan view taken on the line C. D. of Figure 1. Figures 5 and 6 are respectively a plan and an inverted plan of the top base plate which carries the lamp holder and resistance element. Figures 7 and 8 are respectively a plan and an inverted plan of the bottom base plate which carries the battery contacts and the incandescent filament. Figure 9 is asectional side elevation of the bottom base plate. Figure 10 is a theoretical diagram of the electric lamp circuit and its associated resistance and filament circuits. Figure ii is a detail view of the diaphragm mounting. Referring to the drawings and more particularly to Figures 1 and 2 the apparatus comprises a container l which accommodates two 2 volt batteries 2 of different capacities, and said container I is closed by a bottom base plate 3 of insulating material which is carried by a flanged metal ring fl screwing into the mouth of the container l. The central upstanding part of the bottom base plate it affords a plug fitting closure for the bottom of a combustion chamber afforded by a lower cylinder of clear glass 5 and an upper cylindrical porous not 6, whilst the upper end of the combustionchamber is closed by a recessed metal disc or plate I which afiords a diaphragm chamber and is secured to the flanged ring 4 by screw clamping pillars 8. Rubber packing rings 9 are interposed between the ends and parts of the combustion chamber to afford gas-tight joints. The diaphragm chamber is closed bya top base plate III of insulating material upon which is mounted a metal holder l I for a screw-in 4 volt lamp bulb l 2, whilst the diaphragm chamber and combustion chamber are enclosed or surrounded by an outer casing I3 which screws down on to the ring 4 and has an annular series of through ports M in its lower part to admit the outer atmosphere to the porous Wall 6 of the combustion chamber. A gauze ring l5 clamped between an inwardly projecting shoulder on the casing I 3 and the top of the ring 4 serves to exclude foreign matter and to protect the'wall of the combustion chamber. The lamp bulb l2 and holder H are enclosed by a lamp glass l6 clamped between packing rings I! by a lamp cap I8 which is connected to the top of the casing l3 by screwed pillars l8, and the lamp cap I9 is fitted with a carrying handle 20. Within the lower part of the combustion chamber, so that it can be seen through the glass cylinder 5 and the mesh of the gauze ring [5, is a palladium or other filament 2! carried by and between pin type terminals 22 at opposite'ends of a mounting bar 23 of insulating material, said pin terminals being plugged into conductor sockets or sleeves 24 which pass through the bottom base plate 3 and are connected to contact strips 25, 26 on the underside thereof and which bear upon the positive and negative terminals respectively of the larger capacity battery cell 2. The negative contact strip 26 is connected by an insulatedlead 21, let into the upper face of the plate 3 and sealed therein, to a positive contact plate 28 for the other battery cell, and a further negative contact plate 29 for connection with the negative terminal of said other or smaller capacity cell is earthed by a lead 39 to one of a pair of metal bushes 3| whereby, through the medium of securing bolts 32, the bottom base plate 3 is physically and electrically connected to the flanged ring 4 (see particularly Figures 7, 8 and 2). The positive terminal 22 is connected by a conductor strip 33 to a spring-loaded plunger contact 34 which engages the underside of the metal plate i, supported by and insulated from the pillars 8, so that said disc or plate has a potential of four volts. The centre of the plate '1 has an insulating bush 35 in which the tubular stem of the hollow collapsible metal diaphragm 36 is mounted, and the lower end of said stem carries a radial arm 37 which engages the upper end of a contact pin 33 carried by an insulating sleeve in a metal bracket 39 which is secured to the underside of the plate 1. This bracket 39 carries a bi-metallic strip 40 which, when sufficiently heated by the filament 2| below it, bends into contact with the lower end of the pin 38, and so, completes the circuit to the diaphragm 36. i A contact point H on the upper side of the diaphragm engages a contact strip 42 carried by and insulated from the plate '4', and the free end of this strip 32 is engaged by a pressure adjusting screw 43 which passes through the lamp holder l0 and an insulated bearing 44 carried by the plate 1, the arrangement being such as to electrically connect the lamp holder II to the diaphragm 38 through the contacts 42 and screw 43. The negative terminal :35 of the lamp I2 contacts with a conductor strip 46 which connects'it to earth or the ring 4 through one of the insulated bolts 8. 3 Thus when the combined miners lamp and gas detector is functioning normally the filament 2| is connected directly across the 2 volt supply of one cell 2 and the lamp I2 is connected through the bimetallic strip 40, diaphragm 36 and associated contacts, across the 4 volt supply. afiforded by the two cells 2 in series. In the event of an excessive proportion of inflammable gas in the atmosphere a vacuum is created in the combustion chamber and diaphragm 36 so as to cause the latter to collapse and break the contacts 4E, 32. The lamp holder H, however, is connected to one side of a resistance 47, carried by the member l8, and the other side or contact 48 of said resistance engages a conductor strip 459 which is carried by but insulated from the plate I and electrically connected by an insulated lead 53 to the stem of the diaphragm 36. Thus when the contacts ll, 42 disengage as a result of the diaphragm 36 collapsing the voltage-dropping resistance 47 continues to pass current to the lamp i2 which will therefore glow or give an appreciably less illumination than normally. If the dimmed light is insufficient to enable the miner to find his way out of the danger zone he may restore the full illumination by depressing and holding down a spring loaded plunger 5: in the lamp cap 13. Depression of this plunger 5| causes its lower end to depress a further spring-loaded plunger 52, carried by the lampholder ll, into contact with a metal strip 53 in electrical connection with the plate 1, thereby connecting the lamp holder H electrically to said plate l, which is at 4 volt potential, and cutting out or bridging the resistance 4'1, effect upon the bi-metallic strip it causes the lamp [2 to be given its full 4 volt supply so as to, be brightly illuminated. If new the current is turned off a big vacuum will be created in the combustion chamber and associated diaphragm 36 to break the contacts ii, 32 and upon turning on the current again after an appropriate interval the said current will pass through the resistance 47 to give a dim light in the lamp 12 until the vacuum is destroyed by diffusion through the bafile 54, whereupon the contacts 4|, #2 will engage so as to bye-pass the resistance 4! and produce full illumination of the lamp again. The degree of vacuum required to operate the detector circuit may be controlled by appropriate adjustment of the screw 53 to govern or control the initial pressure on the collapsible diaphragm 36 and so regulate or determine the condition or pressure point at which the circuit through the contacts 4|, 42 will be broken. In the event of the filament 2i breaking or being burnt-out cooling in the combustion chamber would cause the bi-metallic strip it to break the circuit of the lamp l2, but by depressing the plunger 52 the circuit of the lamp I? can be completed again so as to enable this miner to find his way out of the workings. I claim: 1. An electrical device for indicating the presence of inflammable gases or vapors including a pressure chamber, pressure responsive selective signal means in said pressure chamber, a porous chamber communicating with the pressure chamber, an incandescent filament in the porous chamher for burning combustible gases diffusing into said vessel so as to create a vacuum therein for operating the signal means to indicate the presence of inflammable gases in excess of a predetermined quantity, and means for delaying the equalization of the pressures between the pressure chamber and the porous chamber for testing purposes. 2. An electrical device indicating the presence of inflammable gases or vapors including a diaphragm chamber, a diaphragm in said chamber a porous chamber communicating with the diaphragm chamber, an incandescent filament in the porous chamber for burning combustible gases diffusing into said vessel so as to create a vacuum therein for operating the diaphragm to indicate the presence of inflammable gases in excess of a predetermined quantity, and testing means including a restricted passage communieating the porous chamber with the diaphragm chamber so as to afford delayed equalization of the pressures to give a delayed operation of the diaphragm for testing purposes. HENRY THOMAS RINGROSE.

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