US2097182A - Gas detector - Google Patents

Description

Oct. 26, 1937. H. A. DODGE ET AL GAS DETECTOR Filed Aug. 24, 1935 2 Sheets-Sheet 1 THEI ORNEY Oct. 26, 1937. H. A. DODGE ET AL GAS DETECTOR Filed Aug. 24, 1933 2 Sheets-Sheet 2 H K 5 R Rm T ODE O A5 NYE l L R A H HC Patented Oct. 26, 1937 UNITED STATES 2,097,182 GAS nE'rEc'roa Harry A. Dodge, and Charles]. Dietrich, New

York, N. Y.

Application August 24, 1933, Serial No. 686,594

4 Claims.

invention is not limited to the automatic detection of gases, vapors and the like of explosive nature, and is useful in detecting gases, vapors and the like afiecting generally a predetermined atmosphere.

In general our invention comprises a lamp or other source of a flame, with which is combined thermostat means responsive to an elevation or depression of temperature, whereby to produce a signal'either audible, visual or otherwise perceptible.

In greater particular, as applicable to an electrical type of system, such thermostat or other suitable means responsive to variation of temperature controls electrically actuated devices, usually including a relay, the arrangement being such that upon variation of electric current arising from variation of temperature the signal is operated. The electrical circuit inclusive of the thermostat means is preferably of the closed circuit type, to thereby insure continuity of operative condition with which advantage is coupled the additional safeguard that upon breaking or other substantial change in the detecting circuit, the signal is operated.

More preferred forms of our system are of such nature that a plurality of unit assemblies, each unit including a lamp and thermostatic means, may be connected by common wiring. In the most preferred forms of the invention, a separate signal or group of signals is arranged for each assembly unit, whereby the assembly unit affected by the presence of explosive or other deleterious gas, vapor or the like is selectively indicated.

Most advantageously, the thermostat means comprises a set of thermostat elements individually respectively responsive to increase of temperature and to decrease of temperature, whereby under the condition of the presence .of a gas of explosive nature, that is to say, tending to in- 3 crease the temperature of the flame, the thermostat element responsive to increase of temperature efiects the operation of the signal, and, similarly, upon the condition of decrease of temperature of the. flame due to the presence of noncombustible or less combustible gas, vapor or the like, the thermostat element responsive to decrease of temperature eifects the operation of the signal.

Combined with our temperature responsive means, we provide a flame extinguishing means whereby in the circumstance of use in a mine or other locality the presence of an explosive gas, vapor or the like entails the danger of explosion, or the danger of asphyxiation or other danger leading to irreparable or serious results. In systems embodying our flame extinguishing means, the operation of the same is had additively to that of eifecting and localizing the danger of the deleterious gas. v

Further features and objects of the invention will be more fully understood from the following detail description and the accompanying drawings, in which Fig. 1 is a diagrammatic view of an electrical .circuit arrangement, illustrating an embodiment of our invention.

Fig. 2 is a detail diagrammatic view of certain parts at a certain operated stage.

Fig. 3 is a detail diagrammatic view corresponding to Fig. 2 but showing another stage of operation.

Fig. 4 is a sectional view of one manner of assembly of a lamp and temperature variation responsive means; and

Fig. 5 is a plan view on the line 5-5' of Fig. 4.

Referring to the drawings, a typical lamp suitable for the purpose is indicated at III. In the application of the invention to mines and other locations subject to the presence of inflammable gases, such lamp I0 is provided with suitable means for minimizing explosion. A typical form of lamp for mines, pursuant to present practice, comprises a metal gauze above and completely surrounding the flame, to retard the passage of ignited gas through the gauze. The particulars of preferred forms of the lamp, per se, are set forth hereinafter.

As is diagrammatically illustrated in Fig. 1, the lamp I 0 is provided with a flame-extinguishing mechanism I l of suitable arrangement which is releasable in response to the presence within the region of the flame of gases, either explosive, asphyxiating or otherwise deleterious, affecting the flame either to increase or decrease its temperature. trated in Fig. 1, comprising asnuifer element l2, in the form of a cap, which cap may be of metal. or other material, such as lavaor the like, 00- ordinated in an electrical system, in which arrangement the cap I2 may be attached to a lever One such suitable arrangement is illus- I3, pivoted at I4 and either of or embodying a suitable section of magnetic material, for cooperation with an electromagnet I5 having a ferrous core I6.

Associated with the flame I0a of the lamp are suitably arranged thermostatic means responsive to increasing and decreasing temperatures of the flame. Advantageousl'y, such temperature variation responsive means is in the form of a thermostatic element I1 responsive to increase of the temperature and a thermostatic element I8 responsive to decrease of temperature.

One form of circuit arrangement of the above stated parts and the desired signalling devices, as illustrated in Fig. 1, comprises a battery I9, which may be a storage battery, supplied with current by an automatic charger 20, energized from the Dower lines 2I, 22.

A conductor 23 connects one end of. the battery I9 with a conductor 24 leading to the thermostat elements, say, to one terminal I8a of the thermostat element I8, its other terminal I8b being connected by a conductor 25 to one end of the winding I 5, the opposite end of the winding being connected by a conductor 26 to a conductor 21. One terminal I1a of the thermostat element I1 is connected by a lead 28 to the terminal I 8b of the thermostat element I8; its other terminal I") is connected to a conductor 21.

The conductor 21 leads to the winding 300 of a relay 30, or other suitable device, for actuating the signal means. In the drawings we have indicated three forms of signals, to wit, an audible alarm '3I such as an electric hell or equivalent, a

visual alarm such as an electric lamp 32, and semaphore 33 and/or equivalent.

The relay 30 is of the combined pivoted armature and solenoid type, having the pivoted armature 44 provided adjacent its free end with a bridging member 63 adapted to engage with the contacts 35 and 36. Attached to the free end of the armature 44 is the semaphore 33 adapted to serve as a visual signal device. Associated with the armature 44 is a core 30a of magnetic material provided on its end with a piece of brass, copper, or other non-magnetic material 30b and which is interposed between the armature 44 and core 30a. Surrounding the core 30a is a coil I30, one end of which is connected to the conductor 21 and the other end to the conductor 32. Normally, current is passing through the coil I30 and therefore the armature 44 is attracted to the core 30a and the bridging member 63 is maintained out of engagement with the contacts 35 and 36. Gravity is ordinarily sufficient to cause the movement of the bridging member 63 into engagement with the contacts 35 and 36 upon failure of the circuit through the coil I30 or from any other cause, though a spring 45 or equivalent device may be employed to ensure such action. Associated with the armature 44 and coil I30 is the solenoid 30c provided with a plunger armature 30!. To one end of the plunger armature 30f is attached one end of a spring 30g, the other end of this spring being attached to one end of an 32, and the solenoid 30c and coil I30 are arranged in parallel.

Normally the current from the conductor 21 to the conductor 32 flows through the. solenoid 30c and coil I30 alike. The plunger armature 30f of the solenoid 300 is pulled into the solenoid against the spring 30g and toward the armature 44. The core 300. is magnetized and will hold the armature 44 against the non-magnetic member 30b. The. pressure of the plunger armature 30) against the armature 44 is not suflicient, under the assumed conditions, to overcome the holding power of the coil I 30. When, however, the current through the coil I30 and solenoid 300 is increased due to a short circuit or due to the operation of thermostat I1 (which shunts out coil I5 and therefore increases the potential across the coil I30 and solenoid 300) the attractive force of the coil I 30 increases but the plunger armature 30f is pulled into the solenoid 300 with increased strength, moving it at a rapid rate of speed against the armature 44 and with a sufiicient momentum to break such armature 44 away from the core 30a, especially as the lever arm available to the plunger armature 30 is greater than the lever arm available to the core 30a. The ease with which the armature 44 may be broken away from thecore 30a is aided by the use of the non-magnetic member 30b interposed between the core 30a and the armature 44.

Assuming the flame I 0a of the lamp to be burning under normal conditions and the atmosphere within the region of the flame to be normal, in which circumstance the thermostat element I8 is in its closed position and the thermostat element I1 is in its open position, and the flame-snuffer element I2 to be in its retracted position, the path of the circuit embodying the above-named parts is as follows:

Current source I9, conductor 23, conductor 24, closed terminals of thermostat element I 6, conductor 25, winding I5, conductor 26, conductor 21, coil I30 and solenoid 30c, conductor 32 to current source I9. The winding I5, being thus energized, retains the snuifer element I2 in its non-operative position. Also, under such circuit conditions, the solenoid 300 is energized to hold the armature 44 in its attracted position, whereby the semaphore 33 is in its elevated, i. e. non-indieating position and the aural and visual alarms 3| and 32 respectively are non-operated.

Assuming, now, the presence of an explosive gas within the region of the lamp flame I0a, or the presence of any gas tending to increase the temperature of the flame, such increase of flame temperature effects the closure of the terminals of the thermostat element I1, under which conditions, the circuit is:

Current source I9, conductor 23, conductor 24, terminals of thermostat element I8, conductor 25, winding I5, conductor 21, solenoid 30 and solenoid 30c, in parallel, conductor 32 to current source I9, under which circuit conditions, the

winding I5 is sufliciently deenergized because of the short circuit between conductors 25 and 21 through thermostat elem nt I 1, thus releasing the snufl'er element I2, w ereby the flame I0a is extinguished.

Upon the extinguishing of the flame I0a as above described, the temperature within the device will bec ome rapidly lowered resulting in the ultimate opening of the engagement between the elements of the thermostat I1 and also the opening of the engagement between the elements of the thermostat I8. Immediately the thermostat I8 is opened the resistance 43 is placed in energizing circuit above described. Under such conditions the amount of current delivered to the windings 30 and 3004s lowered sufliciently to perthe armature 44 moves the semaphore 33 into 'opened and remaining open) the position to be observed. The engagement of the contact plate 63 .with the contacts 36 completes 'two circuits one of which extends from a source of current I3, conductor 23, contact plate 63, contact 36, conductor 31, lamp'32, conductor 33, conductor 32 back to source of current N. The lamp 3221s lighted. Also a circuit is closed from source of current 19, conductor 23, bridging contact 63, contact 36, conductors 39 and 40, audible signal 3!, conductors 4i and 32 back to source of current l3.

To start the device in operation again, the operator will start the .flame Ia and will manually move the armature l3 into engagement with the core surrounded by the winding ii. The thermostat I8 ismade sensitive enough so that the terminals thereof will" close immediately after-the flame Illa is started in operation, and therefore the original energizing circuit above traced will be completed and the armature l3 held in position to hold the snufling device il in the position shown in Fig. 1.

Assuming the presence of a gas within the region of the gas fla e Wu, tending to decrease the temperature ofsthe flame, the reduction of flame temperature eflects the openi g of the terminals of the thermostat element I 3 (the terminals of the thermostat element it having been circuit under such conditions, ,is:

Current source it, conductor 23, resistance 43, winding l5, conductor 26, conductor 21, solenoid 3t and solenoid c in parallel, conductor 3 i conductor 32, to current source it Under suchclrcuit conditions, the reduction in current potential across the winding 63 and the solenoid 360 as in the above assumed circumstance, permits the withdrawal of the relay ture at, accom by the actuation of the alarm or alarms, either mechanically and/or electrically, similarly as above set forth.

Under the circumstance of presence of a noncombustion supporting gas within the region of the lamp flame ltd, the winding se or the snufler element l2, may be. arranged either to efl'ect the releaseof the smifier element 62 to extinguish the flame 03a, or to retain the snufler element 92 in its non-operative position, as may be desired.

ergization of coil i313 to actuate the 'aural and/or visible alarms, accompanied by extin the lamp flame.

A system for detecting and alarm eflecting for a plurality of detection locationsmay comprise individual circuit ts in duplicate of the above described circuit parts, including individual visual and/or aural alarms selectively for such respective circuits.

Desirably, detection'and alarms efl'ecting for a plurality of detection locations, maybe had by circuit arrangement embodying common wiring. For example, in the embodiment illustratedin Fig. 1, in addition to the above described detection location oi the lamp It, a lamp If may be positioned at a location other than that of the lamp ll. The parts associated with the lamp ID 'are designated by like reference characters with a prime suflix. In addition to such like parts, there is the conductor 46 interconnecting the juncture 34' with the conductor 23.

For selective operation or the semaphore 33', lamp 32', or other visible indicator, like circuit and associated parts are employed, corresponding to the above circuit and associated parts, designated by like reference characters with a prime suflix. Inaddition to these parts the 'conductor 41 connects the terminal of the solenoid 33c with the conductor 32. By such arrangement, the

semaphores 33 and 33' are selectively operated respectively upon detection at the locations l3, l0, and likewise the lamps or visible alarms 32 and 32'.

Also, as is illustrated in Fig. 1, the bell or other aural alarm 32 is actuated in common under the condition of detection or presence of an explosive or other flame temperature increasing gas or ofa flame temperature decreasing gas at the stated locations i6 and I0, and similarly for any additional locations as may be desired.

It is understood that the bridging contact 63 and the associated contacts 35, 36, may be in the form of a so-called mercury switch, usually of pivotal type, the (mercury functioning as the jointure contacting material. In such mercury type switch (not shown) the hollow body, usually of glass, is rocked to and fro by direct or indirect connection with the relay armature M, suitable linkage or other operating connections being provided for the mechanical actuation of .the semaphore 33.

I In the use of a common alarm or other indicator, such as the bell M or other aural device, say for a two lamp system, and assuming that detection of the presence of a flame temperature increasing or flame temperature decreasing gas to be indicated, accompanied by the extinction of tiomal conductor M with the lead 38a for connection with the. conductor 40. An additional contact is provided at the terminus of the conductor 3t,'nainely the contact 52, positioned to be engaged by the bridging contact 63 when the relay armature 33 is in its attracted position. Fig. Zillustrates the setting of the movable contact am 6311. of the three-way switch 66 for interconnecting the contact 33, through conductor 3i,- lead 33a, with the conductor 46.

afiting gas at the location of the lamp I6, giving rise to the retraction of the relay armature 44 by its spring 45, to the alarm-indicating position,

1..., g the detection of a flame temperatureas is illustrated in Fig. 3, the attendant upon observing such situation throws the movable contact arm 50a. of the three-way switch from the indicated full line position to its indicated dot and dash line position 501), thus interrupting the circuit through the common alarm 3| with respect to the contact 35. When the trouble on this particular detecting circuit is cleared, armature is attracted by its relay 30, which again causes the signal 3| to sound, apprising the attendant of the changed condition. The attendant therefore operates the three-way switch 50 to. bring the arm 50a thereof into engagement with the conductor 31, as indicated in Fig. 2.

The physical apparatus to be located at the various stations designed to be protected by our improved invention may take any form desired. In Figs. 4 and 5 there is shown one form of preferred apparatus, such form being adapted for either stationary or portable use. Referring to such figures, 64 designates a tank or fuel font containing the liquid fuel 65. Through the upper end plate 6 6 of the font 64 extends the tubular member In through which passes the wick 68, such wick extending into the body of the fuel 65. The wick 68 extends upwardly slightly beyondthe upper end of the tubular member ID, and in a position to be engaged by the sparks generated by a mechanical lighting device 69 secured to the 30 upper face of the font end plate 66.

Secured to the upper face of the plate 66, by screw 10, is a bracket H, in which may be adjustably secured the thermostats I1 and I8, the position of such thermostats l1 and I8 being such that they are acted .upon by the flame Ilia, as above described with respect -to Fig. 1. Leading from the thermostat I1 is a cable 12 containing the conductors 24 and 25, and leading from the thermostat I8 is the cable 13 containing the conductors 21 and 28.

Adjacent to the candle I and the bracket ll, and-secured to the plate 66, is the electromagnet l5, having associated therewith the snufler l2 and armature I6. Also on the plate 66 is secured the resistance 43. On the plate 66 and surrounding the assembly of elements Just described, is a spider frame of metal including a lower ring plate 14 and an upper ring plate 15, in which frame is a cylindrical glass tube It. Secured to the spider frame and thus to the font 64, is an upper frame 11, into which the thermo-- stats I! and I8 may extend. Within the upper frame 11 and forming a cover is a wire mesh screen 18. I

The entire assembly thus conforms to a regulation miners lamp. The various parts are readily disassembled to allow access to the devices within the glass tube 16, and to permit the operator to fill the font 64 and operate the mechanical lighting device 69.

Also mounted'on the plate- 66 is the coil or resistance 43.

The apparatus is adapted to rest on a support,

or to be hung on a hook by means of the eye 19 secured to the top of the frame I1.

Our system may also be arranged to respond to the condition of short-circuit of the line, in which circumstance the current through the relay winding is increased. To meet such condition the relay winding is coordinated to provide for the release of the armature, and thus effect closure'of the alarm circuit or circuits.

Whereas we have described our invention by reference to specific forms thereof it will be understood that many changes and modifications may be made without departing from the spirit of the invention.

We claim:

1. The combination of an open flame exposed to an atmosphere which would affect the combustibility of the flame to thereby vary the temperature of the fiame,.means for directly engaging with and extinguishing the flame, a circuit,

means in said circuit controlling the flame extinguishing means, and a thermostat controlling a break point in said circuit, said thermostat being exposed directly to the heat from the flame and operable upon a lowering of the temperature of the flame to control the circuit for operating the flame extinguishing means, whereby said flame extinguishing means engages with and extinguishes the flame.

2. The combination of a circuit, temperature responsive circuit closing devices in said circuit directly responsive to flame temperature, one of said circuit closing devices being normally open and the other of said circuit closing devices being normally closed, a flame extinguishing means for extinguishing a flame by direct engagement therewith, and means in said circuit responsive to the operation of either of the circuit closing devices for operating the flame extinguishing means.

3. The combination of an operating circuit, a flame snufllng device, means in said circuit for controlling the operation of the flame snufllng device, a thermostat in said circuit exposed to the heat of a flame which is responsive to a lowering of the temperature of the flame for operating said last named means to thereby 'extinguish the flame.

4. The combination of a signal, a flame snufflng device, an electric circuit for controlling the signal, means in said electric circuit for controlling the operationof the flame snufling device, and thermostat means exposed to the direct action of the heat emanating from said flame and controlling said last named means for operating the signal and operating the flame snufling device to extinguish the flame upon a variation in the temperature of the flame.

HARRY A. DODGE. CHARLES J. DIETRICH.

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