US2487156A

US2487156A - High-temperature responsive device

Info

Publication number: US2487156A
Application number: US616578A
Authority: US
Inventors: William G Luttge; Frank T Williams
Original assignee: American Viscose Corp
Current assignee: Akzo Nobel UK PLC
Priority date: 1945-09-15
Filing date: 1945-09-15
Publication date: 1949-11-08
Anticipated expiration: 1966-11-08

Description

av. i949 W. G. LUTTGE E'TAL HIGH-TEMPERATURE RESPONSIVE DEVICE Filed Sept. 15, 1945 ywam/ 4' IN V EN TORS Patented Nov. 8, 1949 HIGH-TEMPERATURE RESPONSIVE DEVICE William G. Luttge, Brooklyn, and Frank T. Williams, New Rochelle, N. Y., assignors to American Viscose Corporation, Wilmington, DeL, a

corporation of Delaware Application September 15. 1945, Serial No. 616,578

20 Claims. (01. 177-311) This invention relates to an element that is responsive to excessive heat and/or the presence of poisonous or explosive gases or vapors.

It is an object of the present invention to provide an element or device which is capable of detecting the elevation of temperatures to an excessive degree as the result of a fire. Another object of the invention is to provide an element which is also responsive to the presence of an excessive amount of explosive gases or vapors in the ambient atmosphere. It is also an object of the invention to provide such an element or device which is responsive to the presence of an excessive amount of poisonous gases or vapors which are detrimental 'to the health of persons working in the presence thereof. A further object of the invention is to provide a hazard-responsive element or device which shrinks under the infiuence of the hazardous temperature, gas or vapor, and by such shrinkage sets into motion a warning, signalling or automatically operated protective device or system. Other objects and advantages of the invention will be apparent from the description thereof hereinafter.

In the drawing which is illustrative of the invention,

Figure 1 is an elevational cross-section of one embodiment of the invention;

Figure 2 is an elevational cross-section of another embodiment of the invention; and

Figure 3 is a cross-sectional elevation of a third embodiment of the invention.

In general, the present invention comprises a hazard-responsive element consisting of a stretched thermoplastic filament, strand, ribbon, band, or strip which is capable of shrinking when brought to a temperature indicative of the fire hazard or when subjected to a gas or vapor having swelling or solvent action thereon when in a concentration or at a vapor pressure or partial pressure in excess of that which is safe for the health of persons working therein. For example, the element which will hereinafter be referred to as being in the form of a, strip (including within the meaning of that term the various specific forms mentioned hereinabove, whether filamentous, fibrous or massive), may consist of a single continuous filament, a thread composed of a plurality of such'filaments twisted together, a cord or strand comprising a plurality of threads twisted together, a knitted, woven or braided band or ribbon, a plurality of continuous filaments in untwisted form disposed either as a flat band or a round bundle, or a thin narrow sheet or film. The element may be formed of various thermoplastic 2 materials, such as the vinyl or related resins, cellulose esters or ethers, nylons, and the like. Examples of the vinyl and related resins include the polymers of vinyl chloride, vinyl acetate,

polyvinyl acetals, copolymers of vinyl chloride with vinyl acetate, or with acrylonitrile, after-, chlorinated copolymers of vinyl chloride with vinyl acetate or acrylonitrile, polyvinylidene chloride, copolymers of vinylidene chloride with vinyl longitudinally after they have been formed. This after-stretching may be performed as a colddrawing or as a stretching of the formed filaments or the like in a partially softened condition, such asmay be obtained by subjecting them to steam, hot air or hot water. The stretching imparts an internally stressedcondition which is released by elevated temperatures, or by the action of a swelling of solvent gas or vapor. The extent of stretching may be various, depending upon the particular material and the amount of shrinkage desired at a particular temperature, or when subjected to an atmosphere containing a particular amount of vapor or gas constituting the hazard. The hazard-responsive element may contain a plasticizer to impart to it a desired shrinkage at a lower temperature than what would normally be the shrinkage of the material constituting the main portion of the element. Examples of plasticizers are tricresyl phosphate, dibutyl phthalate, dibutyl sebacate, thymol, isothymol, parachlorophenol, cinnamyl alcohol and the like. The plasticizer may be used in amounts from 1 to 25% or more, depending again upon the particular material, the extent of shrinkage desired and the temperature of shrinkage.

in all types of systems in which the force that itmust exert varies from a relatively slight to a large force, the latter being as much as from 5 to 10 pounds, the cross-section of the tape would necessarily have to be selected for the particular system. The larger the cross-section, the greater the force that can be exerted. No difliculty is encountered in selecting the appropriate length of the hazard-responsive element, since an identical element can be calibrated to determine the percentage of shrinkage that such element undergoes at a particular temperature against the force which it must exert in the particular system. For example, the followin table lists the percentage shrinkage of a tubular woven braid having a flat width of one inch and having warp yarn of 2165 denier Vinyon and a filling yarn of 1350 denier Vinyon. The Vinyon (copolymer of vinyl chloride and vinyl acetate) is stretched about 800% in production. The table shows the shrinkage at the temperatures given in the table and against the resisting forces listed:

Shrinkage in per cent of original length Pounds 150 F. 175 F. 200 F. 225 F.

Per Per Per Cent Cent Cent I sitive and respond quickly to the presence of the solvent or swelling gases or vapors. The sensitivity may be increased readily by increasing the stretch or by incorporation of plasticizers in greater amounts.

Figure 1 illustrates 'a device comprising the hazard-responsive element of the present invention in which relatively little force is required to be exerted by such element. The device comprises an open housing or bracket 2, having windows 20, and carried by any suitable support in the desired space or room, such as by the ceiling 3. The housing contains a transverse insulating bar 4, carrying an electric switch contact member 5 and an insulating lever B, pivotally mounted at 1,

carrying a complementary electric switch contact 8 and an eyelet 9. The hazard-sensitive element consists of the strip l0, secured at one end to the eyelet 9 and at the other to a fixed eyelet l l. Thus the hazard-detecting system basically consists of a shrinkage element secured to and extending between a fixed member (eyelet H) and a movable member (eyelet 9). The switch contact members 5 and 8 are shown electrically connected in a circuit with power source. l2 and an alarm device l3, such as a bell and a solenoid H. The solenoid l4 operates upon a core l5 which may be the waive of a water line or a carbon dioxide line, or of a line containing any equivalent fire extinguishing fluid. When the hazard involved is a poisonous gas or vapor or an explosive gas, the core i5 may be a switch arm for operating a motor for driving an exhaust fan to discharge the explosive or poisonous gas or vapor from the room. When shrinkage of the hazard-responsive element ll occurs. either as a result of excessive temperature or excessive partial pressure or vapor pressure of a poisonous constituent of the atmosphere, contact I is moved upwardly against contact 5, thereby closing the circuit and causing the alarm to operate. In addition, either the valve to a supply for fire extinguishing liquid is opened or the operation of an exhaust fan is initiated.

Figure 2 is a modification in which the hazardresponsive strip Illa is required to exert somewhat greater force than that in Figure 1 in swinging the lever 6a about its pivot 1a against the resistance of the spring II which extends from a projecting pin i! on the lever to to a stationary eyelet 18. The eyelet II is positioned back or the pivot Ia so that after lever to is swung a predetermined distance the spring its will pass over the pivot 1a through a dead-center position and will of its own force swing the lever into contact with the stationary contact member la, thereby imparting a snap-action to the device. The switch contact members to and 8a may be connected to alarms and protective devices as in Figure 1. The sufiix a is applied to all references in Figure 2 designating parts which correspond to designated parts in Figure 1.

In Figure 3, the hazard-responsive element iilb is shown arranged to eifect the opening of a valve 2| in a supply pipe 22 for a fire extinguishing fluid, such as water or, carbon dioxide. The valve 2| is normally pressed against a ringshaped seat 23 of resilient material such as rubber, synthetic rubber or the like, carried around the valve opening 24 in the pipe. A toggle link 25 is pivotally secured to the valve body 2| at 2' and has its outer end held in place by an inwardly facing wall 21 on the bracket 28 and a projection 29 from that wall. The projection 29 is so positioned that the toggle link 25 is displaced slightly from its dead-center position and so that shrinkage of the element lllb which is secured to the outer end of the link 25 and to the bracket 28 causes the link to pass through the dead center position and then to fall through the slot 30 in the bracket, thereby opening the valve upon shrinkage of the heat-responsive element lllb.

It is to be understood that changes and variations may be made without departing from the spirit and scope of the invention as defined in the appended claims.

We claim:

1. A hazard-detecting device 'i'or detecting noxious and inflammable vapors, fire. and exv cessively high temperatures comprising a fixed member. a movable member, and a hazard-responsive element secured to and extended substantially to its full length between the members, said element comprising a strip of material in a longitudinally stretched, internally stressed condition rendering it responsive to a predetermined hazardous condition by shrinkage thereof upon subjection to the plasticlzing influence of such condition, means for attacking the hazard and means operatively connecting the movable member to the attacking means for initiating operation of the latter upon movement of the movable member resulting from 'a predetermined shortening of the element.

2. A hazard-detecting device for detecting noxious and inflammable vapors, fire, and excessively high temperatures comprising a flxcd member, a movable member, and a hazard-reassmoe.

' ing of the element.

3. A hazard-detecting device for detecting noxious and inflammable vapors, fire and excessively high temperatures comprising a flxed' member, a movable member, and 'a hazard-responsive element secured to and extended substantially to its full length between the members,. said element comprising a strip of thermoplastic material in a longitudinal stretched, internally stressed condition rendering it responsive to a predetermined hazardous condition by shrinkage thereof upon subjection to the plasticizing influence of such condition.

4. A hazard-detecting device for detecting noxious and inflammable vapors, fire, and excessively high temperatures comprising a flxed member, a movable member, and a hazard-responsive element secured to and extended substantially to its full length between the members, said element comprising a strip of filamentous thermoplastic material comprising a vinyl resin polymer in a longitudinally stretched, internally stressed condition rendering it responsive to a predetermined hazardous condition by shrinkage thereof upon subjection 'to the plasticizing influence of such condition.

5. A hazard-detecting device for detecting noxious and inflammable vapors, fire, and excessively high temperatures comprising a flxed member, a movable member, and a hazard-responsive element secured to and extended substantially to its full length between the members, said element comprising a strip of filamentous thermoplastic material comprising a nylon in a longitudinally stretched, internally stressed'conditlon rendering it respons' e to a predetermined hazardous condition by shrinkage thereof upon subjection to the pasticizing influence of such condition.

6. A hazard-detecting device for detecting noxious and inflammable vapors, fire, and excessively high temperatures comprising a fixed member, a movable member, and a hazard-responsive element secured to and extended substantially to its full length between the members, said element comprising a strip of filamentous thermoplastic material comprising a cellulose derivative in a longitudinally stretched, internally stressed condition rendering it responsive to a predetermined hazardous condition by shrinkage thereof upon subjection to the plasticizing influence of such condition.

7. A fire-protective device comprising a conduit inthe space to be protected for conveying a fireextinguishing fluid thereto, a valve opening communicating between the space and the conduit interior, a valve body normally closing the opening, a flxed member, a movable toggle link normally holding the valve body in place, a heatresponsive element secured to and extended substantially to its full length between the fixed member and the link, said element comprising a strip of material in a longitudinally stretched,

member, a pivotally mounted lever, a hazard-. responsive element secured to and extended substantially ,to its full length between the member and the lever, said element comprising a strip of material in a longitudinally stretched, internally stressed condition rendering it responsive to a predetermined hazardous condition by shrinkage thereof upon subjection to the plasticizing influence of such condition, means for attacking the hazard and means operatively connecting the lever to the attacking means for initiating operation of the latter upon movement of the lever resulting from a predetermined shortening of the element.

9. A, hazard-detecting device for detecting noxious and inflammable vapors, flre, and excessively high temperatures comprising a flxed member, a pivotally mounted lever, a hazard-responsive element secured to and extended substantially to its full length between the member and the lever, said element comprising a strip of material in a longitudinally stretched, internally stressed condition rendering it responsive to a predetermined hazardous condition by shrinkage thereof upon subjection to the plasticizing influence of such condition, means for warning of the hazard and means operatively connecting the lever to the warning, means for. initiating operation of the latter upon movement of the lever resulting from a predetermined shortening of the element.

10. A hazard-detecting device for detecting noxious and inflammable vapors, fire, and excessively high temperatures comprising a flxed member, a pivotally mounted lever, an electric I circuit having normally open contact members,

one on the lever and the other on a stationary I age thereof upon subjection to the plasticizing influence of such condition, means for attacking the hazard and electric means in the circuit for operating the. attacking means, whereby a predetermined shortening of the element closes the contact members and initiates operation of the attacking means.

11. A hazard-detecting device for detecting noxious and inflammable vapors, fire, and excessively high temperatures comprising a fixed member, a pivotallv mounted lever, an electric circuit having normally open contact members, one on the lever and the other on a stationary support adjacent the lever, a hazard-responsive element secured to and extended substantially to its full length between the fixed member and the lever, said element comprising a strip of material in a longitudinally stretched, internally stressed condition rendering it responsive to, a predetermined hazardous conditlon by shrinkage thereof upon subjection to the plasticizing influence of such condition, means for attacking the hazard and electric means in the circuit for operating the attacking means, whereby a predetermined shortening of the element closes the contact members and initiates operation of the attacking means, a spring having one end connected to the lever and the other connected to a stationary part so arranged with respect to the pivot of the lever and the stationary contact that the spring exerts a snap-action upon the lever from an intermediate dead-center position toward and away from the stationary contact member.

12. A high temperature detecting device comprising a fixed member, a movable member and a high temperature responsive element secured to and extending substantially to its full length between the members, said element comprising a strip of thermoplastic material in a longitudinally stretched, internally stressed condition rendering it responsive to a predetermined high temperature condition by shrinkage thereof upon subjection to the plasticizing influence of such condition.

13. A high temperature detecting device comprising a fixed member, a pivotally mounted lever member and a high temperature responsive element secured to and extending substantially to its full length between the members, said element comprising a strip of thermoplastic material in a longitudinally stretched, internally stressed condition rendering it responsive to a predetermined high temperature condition by shrinkage thereof upon subjection to the plasticizing influence of such condition.

14. A high temperature detecting device comprising a fixed member, a pivotally mounted lever member and a high temperature responsive element secured to and extending substantially to its full length between the members, said element comprising a strip of thermoplastic material in a longitudinally stretched, internally stressed condition rendering it responsive to a predetermined high temperature condition by shrinkage thereof upon subjection to the plasticizing influence of such condition, means for influencing the source of high temperature, and means operatively connecting the pivotally mounted lever member to the influencing means for initiating operation of the latter upon movement of the pivotally mounted lever member resulting from a predetermined shortening of the element.

15. A fire-protective device comprising a fixed member, a pivotally mounted lever member and a fire-responsive element secured to and extended to its full length between the members, said element comprising a strip of thermoplastic material in a longitudinally stretched internally stressed condition rendering it responsive to a predetermined high temperature condition thereof upon subjection to the plasticizing influence of such condition, means for attacking the fire, and means operatively connecting the pivotally mounted lever member to the attacking means for initiating operation of the latter upon movement of the pivotally mounted lever member 8 tially of a copolymer of vinyl chloride and vinyl acetate mechanically connected with said switch whereby to close it by shrinkage of the thread when overheated.

1'7. An apparatus of the character described, comprising an electrically operated alarm device, an electric circuit in which said device is operatively connected, a normally open switch in said circuit and a prestretched thread composed essentially of a copolymer of vinyl chloride and vinyl acetate connected with said switch, said switch including stationary contact means and a movable contact adjacent to said stationary contact means, said movable contact being mechanically connected to said thread, and said movable contact being adapted upon shrinkage of said thread to engage said stationary contact means to complete said circuit.

18. An apparatus of the character described, comprising switch contacts, a spring tending to hold said contacts open and a prestretched thread composed essentially of a copolymer of vinyl chloride and vinyl acetate operating against the action of said spring to close said contacts when it shrinks due to overheating.

19. Apparatus comprising an electrically operated alarm device, an electric circuit in which the device is operatively connected, a switch in said circuit, an element for controlling the operation of the switch, said element comprising a strip of material in a longitudinally stretched, internally stressed condition, rendering it responsive to a predetermined hazardous condition by shrinkage thereof upon subjection to the plasticizing influence of such condition, said switch including stationary contact means and a movable contact adjacent the contact means for closing the circuit upon contraction of the element, said movable contact being mechanically connected to the element.

20. An apparatus of the character described comprising an electrically operated alarm device,

resulting from a predetermined shortening of the an electric circuit in which said device is operatively connected, a switch in said circuit, and a prestretched thread composed essentially of a copolymer of vinyl chloride and vinyl acetate controlling the operation of said switch, said switch including stationary contact means and a movable contact adjacent said contact means for closing said circuit upon contraction of the thread when overheated, said movable contact being mechanically connected to said thread.

WILLIAM G. LUTTGE. FRANK T. WILLIAMS.

REFERENCES CITED The following references are of record in the file of this patent;

UNITED STATES PATENTS Heigis Mar. 23, 1937