Патент USA US2408052код для вставки
Sept. 24,‘ 1946. K. o. DONELIAN 2,408,051 FIRE AND SMOKE DETECTOR AND THE LIKE Filéd Agsril 4, 1942 000mm \ 1 \ls _. 000m 000m La 000mm 00mm) @(DCDOJQ) 000(000000 0000mm ammooooooooommmm INVENTOR K. O. DONE LIAN‘ ‘Ni/QM ATTORNEY Patented Sept. 24, 194E 2,408,05l UNITED STATES PATENT OFFICE 2,408,051 FIRE AND SMOKE DETECTOR AND THE LIKE Khatchik 0. Donelian, New York, N. Y., assignor to American District Telegraph Company, Jersey City, N. J ., a corporation of New Jersey Application April 4, 1942, Serial No. 437,615 13 Claims. This invention relates to ?re detecting and alarm apparatus, and more particularly to an (01. 177—311) 2 unit comprises also a second chamber contain ing spaced electrodes which is shielded against electrical detecting unit and system responsive the admission of ionized air particles and con to the presence of combustion products and/or tains a quantity of a radioactive material to im smoke in the atmosphere adjacent the detector UK part a normal conductivity characteristic to the unit. space between the electrodes. It is found that The object of the invention is to provide an the presence of smoke particles in the air in said improved and highly sensitive ?re detecting unit space impedes the progress of the alpha radiation which responds to minute traces of either ionized from the radioactive material and thereby re combustion gases or suspended solid particles duces the amount of ionization of the air pro having no electrical charge, generally referred 10 duced by said radioactive material. The effect to as smoke particles. ‘ of the smoke particles is therefore the opposite Another object of the invention ‘is to provide of the ionized air particles, and the shielding a combined ?re and smoke detector of the ioniza means is employed to prevent ionized air par tion type which will respond either to ?res that 15 ticles, if present, from masking the e?ect pro produce little or no smoke, such as those involv duced by the smoke particles. ing organic combustibles like alcohol or gasoline, In accordance with a further feature of the or to ?res that produce only smoke with little or invention, the electrodes and source of potential no perceptible heat or ?ame. are connected in the input circuit of a vacuum A still further object of the invention is to tube ampli?er or other electrical relaying means simplify and improve the construction of an 20 in such a manner that the electroconductive ef electrical detector unit and alarm system of the fects of the two elements of the detector are class described. ‘ , combined additively so that, if both ionized air Hitherto ?re detecting apparatus which depend particles and smoke particles are present in the upon detection of the by-products of combus atmosphere adjacent the detector unit, the effect tion have included smoke detectors embodying 25 is somewhat greater than if only the ionized optical measuring apparatus or gas detectors particles or only the uncharged particles are employing chemicals to detect speci?c gases, present. such as carbon monoxide or carbon dioxide, usu For a better understanding of‘ the invention ally formed in the combustion process. These reference may be had to the accompanying draw prior devices have been relatively complicated, ing showing a preferred embodiment thereof, and as well as unsuitable or unreliable for many ap in which: plications, and have required considerable super Fig. 1 is a sectional view of the detector unit vision and maintenance, such as the periodic re taken on the line l--! of Fig. 2; ‘ placement of exhausted chemicals or parts. 35 Fig. 2 is a side elevational view of the detector The present invention is based upon the well unit with a portion of the outer shell broken known fact that the by-products of combustion away; and may contain ionized molecules or particles, as Fig. 3 is a circuit diagram of the detector unit well as solid smoke particles which have no elec connected in a typical alarm circuit. trical charge. It is also known that the ionized 40 Referring to Figs. 1 and 2 of the drawing, molecules or particles may retain for several a preferred form of the detector unit, drawn to minutes or more their ionized characteristics so about three-quarter scale, comprises an outer that the conductivity of the gas containing said perforated metallic shell or electrode It) par molecules for a considerable period of time is tially or completely enclosing two spaced inner substantially different than that of air at the 45 electrodes II and i2, and acting as an electro same temperature. Accordingly, the detector static shield for the elements enclosed therein. unit in its preferred form includes means such The top of the hollow or cup-shaped electrode as spaced electrodes upon which a predetermined l0 may be closed by an insulating cover or cap l5 serving as a support for lead-in conductors detect the presence of the ionized molecules or 50 l6 and the vacuum tube ampli?er H, as shown. potential diiierence is maintained in order to particles. However, this would not provide for detecting the presence of suspended smoke par ticles in the atmosphere, which sometimes occur without the ionized air particles or molecules. Accordingly, the preferred form of the detector The vacuum tube I1 is substantially enclosed by the electrode i2 which also acts in conjunction with an intermediate partition, I8 to divide the spaces bounded by the electrodes ill, I! and it’ into the three chambers 22, 23 and 24, ‘all of 2,408,051 4 which are open ‘for circulation of combustion gases and smoke from a ?re in the vicinity of the detector unit. Chamber 22 is employed for the detection of ionized air particles since the presence of such particles in the space between electrodes iii and . although the ionized air particles increase the conductivity of chamber 22 and the smoke par ticles decrease the conductivity of chamber 24, the change in potential of the grid 2| of the vacuum tube is in the same direction in each case so that there is no tendency for one e?ect to com pensate or cancel out the other but rather the combined effect results in quicker response to a ?re. As shown in Fig. 1, the inner electrode 5?. the detector unit connected to the control elec completely enveloped by chamber 23 and by the 10 of trode or grid 2| of the vacuum tube ampli?er imperforate insulating members 15 and i8 so that extends into both chambers 22 and 24 of the all of the air and gases circulating through cham detector unit, and the electrodes Ill and H are ber 24 must ?rst pass through the outer cham connected to the positive and negative terminals, ber 23, for reasons which will be explained below. respectively, of the» source of potential. This is The inner chamber 24 contains a quantity‘ of represented diagrammatically in Fig. 3, in which radioactive material 2% which normally ionizes 12a and IE1) represent the two parts of the elec_ the air in said chamber to a ?xed degree. How trode l2, and the spaces between said electrodes ever, the presence of solid smoke particles in sus and electrodes ii] and H represent the chambers pension in said air impedes the alpha emana through which combustion gases and smoke par tions from the radioactive material 28 and thus * ticles circulate in the event of a ?re. A source of reduces the conductivity of the space between potential impressed upon the electrodes. of: the electrodes H and i2 so long as smoke is present. unit is represented by the battery 25. In order In order to prevent ionized air particles and the to secure the proper cathode-grid bias, depend like, which may be contained in the air currents around the detector unit, from nullifying the . ing upon the characteristics of the tube ll, a second source of potential 26 may be connected, ‘ effect. of smoke particles in reducing the con~ for example, in the, cathode circuit of said am ductivity of the air or gases in the inner cham~ pli?er. A normally deenergized alarm. relay 2% ber 24, the electrodes IE3. and ii are maintained and a normally energized trouble relay 29, are at a suf?ciently high di?erence of potential to shown by way of illustration, as connected in de-ionize the circulating gases entering chambers i2 causes a variation in the conductivity charac teristic of said space. On the other hand, cham ber 24 bounded by the electrodes H and I2 is 23 and 24. The voltage impressed between elec ‘ the, plate circuit of’ the vacuum tube, ampli?er trode it and electrode II, for example, may be 100 volts, since a potential gradient of the order of ‘L0 or 50 volts per centimeter is su?iciently high to neutralize the charges on any charged par ticles in a slowly moving air current. In this manner, the charged particles are ?ltered out of Ill. The contacts of relay 2.3I'are arranged to control a buzzer or alarm device 30,. whereas the contacts of the relay 29 are arranged. to operate a similar trouble signal 3.! in the event that the plate current of the ampli?er H drops below its normal value, as would be caused by failure of the battery, breaking of. the connecting conductors the. air currents entering chamber 21;, while the or failure of the vacuum tube itselii. smoke particles suspended in the air will enter Under normal conditions, the. potential of the chamber 2!; and reduce the ionization in said 4.0 grid 2! of the vacuum tube ampli?er H is main chamber as. described above. tained at a predetermined potential,7 by reason It will be apparent from the foregoing descrip of the connection of said grid tothe, terminals tion that either the ionized-particle detecting of the battery 25 through, the resistances repre element. or the smoke detecting'element of the sented by the spaces between; the. electrodes Ill 45 detector unit shown in Figs. 1 and 2 may be used and‘ lZa, and H and I21), respectively. This po tential is preferably so chosen with respect; to that ofthe cathode; that the, ampli?er-7H‘ is con simple and effective manner is the preferred ductive and‘ the plate current thereof. is, sui?cient construction. It will also be apparent that the con?guration and arrangement of the electrodes 50 to maintain the cont-acts of the trouble relay 2.9 open but insu?icient to operate the,‘ marginal may be widely varied without departing from the alarm relay 28. If‘, however, the conductivity of operating requirements outlined above, which re» independently, although the arrangement shown in which the two elements are combined in a . the space between the electrodes H1 and, l2a; is increased, owing to the presence of ionized air chamber and the smoke detecting chamber be open to the air for circulation of the by-products 55 particles to, which the, detector unit is responsive, the potential of the grid. 2|; of the ampli?er ll of combustion from the ?re therethrough; and, becomes more positive, and; the, increased plate second, that the chamber containing the radioac current of the ampli?er actuatcs the'contacts of tive material must be shielded against the ionized relay 28 to sound the alarm 3!}. Similarly; it the air particles. The radioactive substance 2Q may conductivity of the space between the electrodes be a ceramic ?lm containing radium or some ra 60 H and lZb decreases» upon the occurrence of dioactive salt. Reference is made to this mate smoke in said space, the grid 2 l» of‘ the, ampli?er rial because it may be purchased in this form in ll likewise becomesv more positive than before, the open market but other forms may be substi and thus the alarm relay 2.8; is operated either tuted. For the preferred arrangement shown in quire-?rst, that the ionized-particle detecting Fig. 1, approximately one microgram of radium 65 upon the occurrence of ionized air particles or of smoke particles in the combustion gases from .in ceramic ?lm fonm described above is used. In accordance with a further feature of the invention, the electrodes and the source of cur rent are so connected to the input circuit of a vacuum tube ampli?er H or other relaying means 70 that the opposite electroconductive effects in the two detecting chambers are additively com bined. In this manner, if the by-products of the ?re, and the electroconductive' effects are additive when both conditions occur simultane ously. Therefore, it will be seen that thedetector unit will respond. to either so-called smokeless ?res or to ?res which produce. smoke with no perceptible ?ame» or heat, as Wel_1_as to ?res in which considerable ?ame and smoke are both produced. combustion from the ?re include both ionized air particles and solid smoke particles in suspension, 75 ' While the vacuum tube ampli?er I1 shown in 5 2,408,05 l. Fig. 3 is a triode, any high gain pentode ampli?er of the 38, 606 or other type may be used, provid ing its input or grid resistance is very high. It has generally been found desirable to reduce the ‘filament voltage impressed to approximately 60% of the rated normal value to reduce positive ion , emission to a negligible value in order to obtain this high grid resistance. It is also to be noted that, although only one stage of ampli?cation is shown, additional stages may be provided if de sired, depending upon the operating current re quirements of the control relays. ‘one of said electrodes being common to two of said spaces, a vacuum tube having the control electrode thereof connected to said last-mentioned electrode and means having said vacuum tube and said electrodes as parts thereof for detecting the presence of ionized air particles in one of said two spaces and smoke particles in the other. 5. A detector unit for ?re alarm systems com prising a plurality of spaced electrodes de?ning spaces open to the atmosphere for circulation of combustion products from a ?re therethrough, a While no special mounting arrangement or ‘vacuum tube connected in a manner to be con smoke comprising spaced electrodes de?ning two in with an additive control effect upon the pres trolled by variations in the electroconductive positioning of the detector unit is required in characteristic of one of said spaces, means for many installations, conventional means, such as 15 normally ionizing said one of said spaces to a sampling pipes, may be employed to direct com predetermined degree and means for shielding bustion gases and smoke from distant ?res to the same against entry of ionized air particles the detector unit. Various other modi?cations whereby the conductivity of said space is varied and auxiliary arrangements will occur to those skilled in the art and may be employed without 20 by the presence of smoke particles therein, said vacuum tube also being connected in a manner departing from the scope of the invention as to be controlled in the same manner by the elec de?ned in the appended claims. ' troconductive characteristics of another space I claim: caused by the presence of ionized particles there 1. A detector unit for detecting either ?re or separate chambers through which pass the com 25 ence simultaneously of smoke particles and ionized particles in the respective spaces. bustion products from a ?re in the space to be 6. A detector unit for ?re alarm systems com protected, means to maintain a difference of po prising at least three spaced electrodes de?ning tential between said electrodes, and detection adjacent spaces exposed to combustion products means having as parts thereof a pair of said elec trodes to detect a changejn the conductivity of 30 from a. ?re in the space to be protected, the said product including either ionized molecules or the gases in one of said chambers resulting from solid particles in suspension in the form of smoke, ionized air particles or molecules reaching said or both ionized molecules and smoke particles, 2. chamber from a ?re, said detection means hav source of potential connected to said electrodes,‘ ing as part thereof a third electrode cooperating with one of said pair of electrodes to shield the 35 means for ionizing the air in the space between two of said electrodes, and means so co-acting other of said chambers from ionized molecules, with said electrodes as to detect jointly and sev said third electrode cooperating with the other erally by electroconductive eiiects smoke particles of said pair of electrodes to detect smoke par in suspension in the ionized air between two of ticles in suspension in the air or gases in said 40 said electrodes and‘ionized molecules in the air other chamber. . in another of said adjacent spaces between two 2. A detector unit for detecting smoke compris of said electrodes. ing at least three nested electrodes de?ning two '7. A detector unit for ?re alarm systems com chambers‘ or cavities open to the atmosphere, one of said chambers being enveloped by the other, a quantity of radioactive material in said one chamber, means having two of said electrodes as parts thereof for neutralizing charged or ionized particles from the air or gas in the other cham ber whereby the air or gas circulating through the chamber containing radioactive material is free from charged particles except as produced by such material and means having two of said electrodes as parts thereof for detecting changes in conductivity of the air or gas in said one cham ber upon the occurrence of smoke particles sus pended in the air or gas therein. 3. A detector unit for ?re alarm systems com prising at least three spaced electrodes de?ning adjacent spaces exposed to combustion products from a ?re in the space to be protected, the said products including either ionized molecules or solid particles in suspension in the form of smoke, or both ionized molecules and smoke particles, a source of potential connected to said electrodes, means for ionizing the air in the. space between two 'of said electrodes, and means so col-acting ‘ with all of said electrodes as to detect by elec troconductive e?ects smoke particles in suspen sion in the ionized air between two of said elec trodes and ionized molecules in the air in another of said adjacent spaces between two of said elec trodes. prising a plurality of spaced electrodes de?ning 8. A detector unit for ?re alarm systems com at least two spaces in inner and outer relation and open to the atmosphere for the circulation 60 prising spaced electrodes exposed to combustion products from a ?re in the space to be protected, of combustion products from a ?re therethrough, the said products including either ionized mole an inner one of said spaces ple?ned by two of said cules or solid particles in suspension in the form electrodes being completely enveloped by a space of smoke, or both ionized molecules and smoke between two of said electrodes, said inner space 65 particles, 3, source of potential connected to said containing means to ionize the gas therein to a electrodes, means so co-acting with all of said predetermined degree, means to deionize gaseous electrodes as to detect ionized molecules between combustion products prior to entering said inner a pair of said spaced electrodes and uncharged space, and means having the electrodes de?ning smoke particles in suspension between a third the inner space as parts thereof for detecting electrode and one of said pair of electrodes and smoke particles in said inner space. ‘ a common biasing control circuit included in said 4. A detector unit for ?re alarm systems com means and so connected to one of said electrodes prising spaced electrodes de?ning a plurality‘ of that said means is affected by both ionized mole spaces open to the atmosphere for circulation of cules and smoke particles in suspension from ?re combustion products from a ?re therethrough, 75 producing combustion products containing both. 552,408,051 9.. A detector unit for detecting either ?re or smoke comprising at. least three spaced electrodes de?ning two separate chambers through which pass the combustion products from a ?re in the space to be protected, means to maintain a dif ference of potential between. said electrodes and means co-acting with all of said electrodes to detect ionized air particles or molecules in one the. vacuum tube, and means having said elec trodes and said tube as parts thereof for detect ing variations in the conductivity path between said electrodes. l 12. A detector unit for ?re alarm systems com prising spaced electrodes de?ning a plurality of adjacent spaces. open to the atmosphere for cir culation of combustion products from a ?re there through, means. for ionizing the atmosphere in of chambers and uncharged smoke particles one of saidtspaces, a source of potential connected in the other chamber by electroconductive effects, 10 to said electrodes, and a vacuum tube ampli?er said electrodes being so associated each to the " connected to said electrodes to be controlled in other and to. said means as to additively combine the same manner by the variations in the con effects when both ionized molecules and un ductivity of said spaces resulting either from charged particles are present. 10. A detector unit for ?re alarm systems com 15 smoke particles. 'to the substantial exclusion oi transient ionizedv air particles in a space of ionized prising at least three electrodes de?ning cham atmosphere or from ionized air particles to the bers open to the atmosphere for circulation of substantial exclusion of smoke particles in an‘ combustion products from a ?re therethrough, a vacuum tube having its control element con nected. to one of said electrodes, a source of po tential so connected to said electrodes and to said vacuum tube that each electrode is at a different potential from that of each of the other elec trodes, means for. ionizing the air in one of said other of said spaces, with an additive control ef fect upon simultaneous changes in the conduc 20 tivity of said spaces. 7 13. In a ?re alarm system, a vacuum tube am plifier provided with a control electrode‘, a detector unit connected to said control electrode, means ionizing the atmosphere in a part of said unit, chambers, and» means including said electrodes, _-25 for and means in said unit to vary the potential of vacuum tube, and source of potential for detect said electrode in'the same direction upon the oc ing variations in the conductivity of the space currence of either smoke to the substantial ex paths of the respective chambers resulting from clusion of transient ionized air particles, in a part di?erent types of combustion products in the re of said unit having ionized atmosphere or of spective chambers. ' 11. A detector unit for ?re alarm systems com "so ionized air particles to the substantial exclusion of smoke in another part of said unit, and to vary prisingv cup-shaped perforated shell electrode, the potential , of said electrode upon the oc a second hollow electrode inside of the ?rst-men currence. simultaneously of both ionized air par tioned electrode and spaced therefrom, a vacuum tube supported inside of said second electrode and 1:35 ticles and smoke in said unit, said last-mentioned having the control element thereof connected to the second electrode, a. source of potential con nected to the two electrodes and to the anode of potential variation being an additive function of the separate variations. , KHATCHIK O. DONELIAN.