US2101637A

US2101637A - Multiple action thermostat

Info

Publication number: US2101637A
Application number: US37421A
Authority: US
Inventors: Davis George Howlett
Original assignee: Individual
Current assignee: Individual
Priority date: 1935-08-23
Filing date: 1935-08-23
Publication date: 1937-12-07
Anticipated expiration: 1954-12-07

Description

Dec. 5'; gq H, DAWS 2,101,637

MULTIPLE ACTION THERMOSTAT Fild Aug. 23, 1935 Patented De'c. 7, 1937 UNITED STATES PATENT OFFICE 16 Claims.

This invention relates to multiple action thermostats and in its application to automatic thermoelectric fire alarms the principle herein involved is illustrated and described in the modi- `5 ed ystructures of my applications for United States patents given Serial Number 732,172, led June 23, 1934, and Serial Number 8,776, led February 28, 1935. 'Ihis application is a continuation in part of my two said co-pending applil cations.

The present invention has numerous applications or uses and is susceptible of many modifications other than those just mentioned and those shown and described herein without avoidl ing the spirit of the discovery,

When used as a local detector of accidental fires in conjunction with distant signals or annunciators in circuit therewith the Xed thermostat would be adjusted with micromatic accuracy to function in its expansible movement at any predetermined temperature ranging from say `60 F. to 160 F., but preferably is factory set at 110 F. for household, hotel and other like usages where the device is designed to give timely warning of the impending danger.

usages just named the rate-of-rise or quick-acting thermostat, in event of a fast lire, would function in advance and independently of the xed thermostat and generally within from one to ve seconds from the time of the starting of this most dangerous form of accidental fire. The lowering temperature thermostat acts independently of both the xed and the rate-of-rise thermostats, all as will now be more particularly described. y

In the accompanying drawing like numerals of reference thereon indicate corresponding parts which appear in two or more of the views, wherem Fig. l is a perspective View of my round form of multiple action thermostat with the casing or cover in operative position.

Fig. 2 is a plan view of the interior of the structure below lines 2-2 of Fig. 3.

Fig. 3 is a transverse vertical section of Fig. l.

Fig. 4 is a perspective View of my multiple action thermostat arranged in a casing of rectangular shape with several of `the parts shown in Figs. l, 2, and 3 omitted.

Fig. 5 is a plan view of the structure of Fig. 4

with the cover removed in order to show clearly the interior parts.

Fig. 6 is a bottom view of the structure of Figs. 4 and 5.v

Referring specifically to the round form of In the" mydevice as by Figs. 1, 2, 3, I provide a cupshaped casing I 0, which is preferably made of insulating material, such as molded Bakelite, provided with a cover Il, preferably oi stamped out sheet Bakelite, and secured by the screws l Ia 5 to the casing l0. The widely spaced holes I Ib and the closely arranged series or' holes Hc are .stamped thru the cover ll in the same operation which punches the holes therein for sc'rews lla, and blanks out the cover. In the bottom of the 10 casing l0 (see Fig. 3) is molded the closely arranged series of holes IDU which are in vertical registry with the holes llc of the cover li.

What I term the rate-of-rise or the quick-acting thermostat comprises mainly the arch shaped l5 and relatively thin bimetal blade l2 and its coacting parts, as will now be more particularly described. 'I'he said bimetal blade i2 is secured at one end to the binding post lt supported by the panel disc I9 of sheet Bakelite and having a 20 series of holes therein, l9a, as shown, in vertical alignment with and similar to the series of holes l lc or lb. The said blade l2 is aligned as shown between the three series of inlet holes last described and has at its free end the contact point 25 ia.

What I term the fixed thermostat, in its application to the round form of my device, comprises the bimetal blade i4 secured and supported at one end by the swivel binding post l5 and hav- 30 ing at its longer free end Ma the two contact points lib and Mc, its short free end Md, being bent outwardly, all as more clearly. shown in Fig. 2f The longer free end lila bends expansibly or outwardly under a rising temperature until its 35 contact point hib impinges the Contact point Ita upon the end or" the adjustment screw i617 supported in the binding post i6 set in the insulated panel disc i9. The coil spring I'l serves to normally hold the short end Idd of the blade lll 40 against the stop post 20 and this spring also serves as a metallic connection between the post 20 and the swivel binding -post I5. Under a lowering temperature the blade I4 bends contractively or inwardly and when the ambient atmos- 45 phere reaches a predetermined temperature of say 68 F. the contact point Mb completes circuit thru the contact point I8a in adjustment screw |811 in binding post I8 which latter is anchored in the panel disc I9. In the stop post 20 50 is an adjustment screw 20a by means of which the contact points Mb and Mc are adjusted in any desired spaced relation to all other contact points, viz I 2a, I6a, lila. All supporting binding posts are preferably riveted in position on the panel disc i9 as otherwise the great vibration set up in the device when actuating would loosen securing nuts.

In the round form of my device I may secure to the upper side of the panel disc i9 the two blade contacts Zia, 28h, for the reception of the plugs 22a, 22h of the plug 22, which may be of any standard oi' special design and the connecting wires 22e, 22d of which are preferably connected in multiple with a distant alarm, signal, annunciator box, or other controlled mechanism designed to perform any usual or special function. The connection to the latter mechanisms may be made thru a relay or transformer thus permitting of employing thru the extension plug currents of different voltage from that which actuates the multiple action thermostat.

In the round form of my thermostat I also may employ a metal push button 23 supported by the casing ill, the stem 23a being encased in a delicate expansion coil spring 23h which keeps the ferrule 23o normally pressed against the inside of the casing lll and in juxtaposition with the short free end Mid of the bimetal blade Ml, as clearly shown in Fig. 2, so that when the button 23 is manually pressed inward the longer free end lila of the blade l@ is moved with its contact point Mb against the contact point i511, thus completing the circuit thru the device and all the mechanisms in the circuit and causing the latter to actuatc. This provides a simple and effective method of testing both the operativeness of the devices in circuit and ascertaining whether the source of supply is alive.

The rectangular form of my device, as shown in Figs. 4, 5, and 6, is simpler than the round form just described in that it does not embody the extension plug 22, or the testing button 23, but it is obvious that these. elements may readily be added to the rectangular lform. In its rectangular form a thin partition wall 2li is provided which acts as a division wall or bale plate in the dissemination of inowing heated air when moving at a relatively rapid speed, such as occurs during a fast fire and serves to cause such currents of air assisted by the specially arranged inlet openings 25a, 26a, to rst heat the bimetal blade l2 sufciently to cause it to move towards and contact with the blade lll before the latter is heated sufficiently to cause it to move out of the way. while in the case of a slow accidental fire accompanied by a relatively slow movement of the heated air without and within the casing such air is disseminated almost uniformly throughout the casing thus causing the blade Id to move towards the contact Ilia, and complete circuit therewith before the uniformly moving blade l2 can catch up with and form contact with the blade lll, all as more clearly shown in Fig. 5.

The peculiar continual pursuing, in both forms o'f my device, of lthe free contacting ends of the two bimetal blades l2 and Il as hereinbefore described is mostly due to the special arrangement and number of the inlet openings of the casingv which differentially aiect different areas within the casing according to the different speeds of movement of the heated air within the casing, all as substantially shown and described. The round form of casing needs no partition wall 2Q because its blades are oppositely disposed within the casing, while in the rectangular casing the two blades l2, lli are arranged in close paralielism, and without the thin partition 24 both would be similarly affected by the varying speeds of movement within the casing. The two bimetal blades l2, M, of the rate-of-rise and fixed thermostats are shown in Figs. and 2, respectively, in the positions they assume when factory adjusted at a temperature of '70 F. The casing 25, or rather its body portion, is preferably formed of an integral Bakelite molding and embodies holes for the various binding posts, and screws as well as the series of holes 25a.

When designed' for closing low voltage currents either my round or rectangular shaped casing may be employed as shown, but when used for closing currents of over 90 volts then the thermostats would be encased in a terminal box of any standard approved form.

In instances Where it is desired to employ my improved device as an automatic thermoelectric detector sounding a separate alarm or signal for also operating home or other heating units then the contact Mib of the round form casing would be spaced so that when the temperature drops to say 68 F. a separate circuit would be completed'between contacts idb and 68a thereby actuating a draft opener or performing more complicated functions. By the use of a step-down transformer householders could run bell wiring to open thedraft door of their small furnaces. but preferably electricians would make such connections even for small. homes. be donc without in the least interfering with the operation of the device as a fire detector and alarm actuator of the multiple action thermostat type which requires no servicing, which latter objection becames serious in installations for small homes where the cost of periodical servicing would become a serious objection.

In all instances the casing for the thermostatic blades should be air tight except for the several series of inlet holes, Mb, lla, lila, 25a, 25a, and those thru the panel disc GS, and the most efcient arrangement -of such inlet holes can only be obtained thru experimenting upon every change in the shape of the casing and the location of the two thermostatic blades.

Having described two forms of my multiple action thermostat with particular reference to their structural features I will now endeavor to elucidate their modus operandi with special ref-b erence to the essential principles involved, including the air directional means employed. First, suppose that one of my thermostats ls located at or near the ceiling of a bed room in a residence or hotel where the door andwindows are closed, and that an accidental re starts therein. Then such re will gain force but slowly because of the lack of an air draft and the heated air will rise and move about the room,

principally at the ceiling, slowly, as likewise within the casings l, 25 of my devices and resulting in a nearly uniform distribution of the air therein. This causes both the fixed and rate-of-rise l bimetal blades iii, l2, to bend outwardly or toi wards the fixed contact point i60. at a nearly uniform rate until the blade lf3 impinges said contact point and completes circuit therewith'.v

Next suppose that a fire starts in the sameroom under like conditions except that the door and windows are open, then the initial ame will be fanned kwith gathering force into a disastrous conflagration, all as is generally well known. Under the last named conditions the now rapid- 1y moving heated air would enter the casing of my. device thru some of its inlet openings and All this could pass out through others thus setting up a draft of heated air within the casing with the major volume of the heated air passing in a nearly straight line between the points of the casing having the larger or more numerous air inlets and causing the bimetal blade I2 of such draft to first become heated and cause it to overtake and make contact with the scarcely moving blade I4. The surplusage of heated air would pass around my device. The wells of open stairways are veritable draft creators and these vulnerable points should be protected by locating one of my thermostats upon the ceiling directly at the `top of the stairway where a maximum movement of heated air would pass from rooms and other places below and in which instance my rate-of'- rise thermostat would generally operate ahead of the fixed thermostat for the reasons given.

A slow or ordinary iire as I have employed the terms herein may be defined as one in which the temperature rises at the rate of from 1 F. to 4 F. in one minute at the ceiling and where the heated air moves from one point to another at the speed of from four to twenty yards per` minute. At this slow movement a relatively small volume of the heated air would, in the case of my round form of device, enter thesmall and widely spaced inlets IIb, while a considerably larger volume would enter slowly the larger and more numerous inlets IIlband pass upwardly thru the inlets I9a and out at the inlets llc, or the direction of the slowly flowing heated air may be reversed. In any event the slow passage of heated air thru the casing IU would cause it to distribute itself almost uniformly within the casing much as it would be doing in the room where the slow fire had started. Under these conditions the bimetal blades I2, I4 would bend in the same direction at a nearly uniform rate and thus preserve their original spaced relation until the blade I4 was stopped in its movement by contact with the point I6a when the blade I2 would catch up with it and help hold it in a circuit closing position.

Now a fast rapid or hot accidental re is one during which the temperature rises from 6 F. to 20 F. per minute accompanied by a heated air movement of from to 125 yards per minute.

Only a small volume of this rapidly moving heated air can enter the casing I0 and naturally the greater part of this volume passes thru the inlets Illb, I9a., and IIa in a nearly straight line and it is within this line or draft" of heated air that the rate-of-rise bimetal blade I2 is located and under which conditions it completes circuit in from one to five seconds after the starting of a "fast lire.

The rst act of expert firemen upon reaching a fast iire is to stop all drafts possible while my device induces air drafts within its casing at all times but controls the direction of such drafts in the manner, by the meansand for the life and property savingv purposes herein described. Y

I claim; y

1. A multiple action thermostat for actuating electrically operated mechanisms in circuit therewith said thermostat comprising a bimetal blade which acts as a xed thermostat and operates under slow or-ordinary accidental ilre conditions at a predetermined temperature for which it has been adjusted, a secondary quick-acting bimetal air, and means for directing said rapidly moving heated air rst and mostly against the said secondary bimetal blade. p

2. A multiple action thermostat comprising two bimetal blades operatively associated within a casing provided with two sections with a thermostatic blade' in each of the casing sections and with air passages located in the wall of only one of the sections in a manner to differentially affect the two blades by varying the direction of movement of the superheated air arising from a conagration from the outside of the cover to the inside thereof under varying accidental fire conditions and whereby one blade closes the operating circuit at a predetermined temperature under conditions produced by a slow or ordinary fire, said means also causing the other bimetal blade to act more quickly thanthe first whenever a relatively fast accidental fire occurs and sets a relatively fast movement of the heated air from without to within the casing.

3. A multiple action thermostat comprising two bimetal blades supported within a casing provided with two sections with al thermostatic blade in each of the casing sections and with air passages located in the wall of only one of the sections in a manner to differentially affect the two blades, one of which blades acts independently of the other as a thermally operated switch responsive to a relatively slow rate-of-rise and movement of the ambient air caused by a slow or ordinary re when the slow movement of the 4air Within the casing allows the air to be uniformly distributed within` the casing, and means causing the air arising from a relatively fast re to be first and mainly directed against or around the second blade and cause it to make a circuit completing vcontact withits companion blade before the latter can move out of contacting relation with said lrst blade.

4. A directional air-drafted thermostat comprising a casing provided with two sections, air vents in the wall of one of said sections, a primary -blade in one of the sections and a secondary blade in the other of the sections, said blades being bendable in the same direction and plane at their adjacent free ends under the influence of heated air entering said casing, the said air vents serving to cause a relatively uniform distribution of the air entering the casing under conditions attendant upon a slow accidental fire when the said adjacent free ends will preserve substantially the same spaced relation to each other, while the -said air vents under the conditions of a relatively fast re cause the secondary vblade to overtake and form contact with the primary blade before the latter can move out of the path of movement of vthe secondary blade.

a revolvable support upon which said blade is mounted whereby said blade is allowed to be pivotally revolved and cause the free end thereof to complete a circuit through the device and thus indicate its operativeness.

6. In a device of the character described, the' combination with a closed casing, and a bimetal` blade for controlling electric circuits together with a movable post on which itis carried, and means for testing the operativeness of the circuits consisting of a manual device in the wall of the casing having a resilient stem adapted to engage the blade and move it,V a pivot revolvably supporting said blade so that the contact points will operate to complete the circuit and thus indicate the operativeness of the device wheneverthe resilient stern is pressed inward.

7. In a device of `the class described, the combination of a closed casing and bimetal blades mounted therein operatively arranged in association with each other, and a movable pivot on which one of the blades is mounted so as to have a long arm and a short arm, means for carrying the other blade at the end thereof, and a push button supported in theA wall of the casing and having a yielding stem-which engages the short arm of the blade soas to move the same on its pivot and cause the long arm to complete the circuit and thereby indicate the operativeness of the devices.

8. A multiple action thermostat, comprising essentially the combination with a casing having two diierently ventilated interior sections of bimetal blades separately arranged in each section and opposite to each other, means for supporting each of said blades at contiguous ends so thatithe other ends carrying contacts may have free coactive movement in the same plane.

9. A multiple action thermostat comprising a closed casing having one interior section freely ventilated by numerous apertures in the casing thereabouts and a restrictively ventilated interior section contiguous with the other section; a thermo-active bi-metal blade switch located in said freely ventilated section proximate to or between said apertures in the casing said blade switch serving as a quick acting thermostat when cooperatively associated with a secondary thermoactive blade-switch located Within vthe said restrictively ventilated section of the casing.

10. A multiple action thermostat comprising a closed casing having'one interior section thereof freely ventilated by numerous apertures thereabouts. in the wall of the casing, and a restrictively ventilated interior section contiguous with the other section; a primary thermo-active bimetal blade-switch located in said freely ventilated section proximate to and between oppositely disposed apertures in the casing; a secondary thermo-active bi-metal blade Switch located in the restrictively ventilated section; said bladeswitches moving in the same plane and preserving substantially the same spaced relation at their free adjacent contacting ends under normal or relatively slow movements of heated air thru or within the casing but making circuit-completing contact with each other at their free ends Whenever a fast movement of heated ambient air or relatively rapid rising temperature occurs ,in which event a proportionately great amountI of the fast moving heated air first impinges said primary blade-switch and causes it to flex or bend aroma? towards and against the said secondary blade and complete contact therewith before the latter is caused to move out of the way.

11. A rate-of-rise thermostat, comprising essentially the combination with a casing having two differentially ventilated interior sections of bi-metal blades separately arranged in each section and opposite to each other, means for supporting each of said blades at contiguous ends so that the other ends carrying contacts have free co-active movement in the same plane.

12. The combination vwith a fixed thermostatv having a casing with air passages therein,ua thermosensitive blade-switch which is freely ventilated by said air passages, of a secondary thermosensitive blade-switch located in a restrictively ventilated section or compartment of said casing and having its free contacting end cooperatively associated with the free contacting end of the said primary blade-switch.

13. A multiple action thermostat comprising a closed casing having interior sections one of said sections being freely ventilated by apertures in the casing thereabouts and a restrictively ventilated interior section contiguous with the other section, a thermo-active bi-metal blade-switch located in said freely ventilated section proximate to or between said apertures in the casing; a secondary thermo-switch blade mounted in the casing; said blade switches serving as a quick-acting thermostat when cooperatively associated with each other.

le. A rate-of-rise thermostat comprising a casing said casing having two sections, air ventilating openings in one of the sections forming two differentially ventilated sections, bi-metal blades located in each of said sections, means for mounting each of the blades at one of their ends and the other ends being free, and contacts on the free ends of the blades cooperatively associated with each other.-

l5. A rate-of-rise thermostat comprising a casing, said casing having a partition extending substantially the length of the casing forming two sections, air Ventilating openings in one of the sections forming two differentially ventilated sections, thermosensitive blades arranged in each of said sections, means for mounting each of the blades at one of their ends, and the other ends being free, and contacts on the free ends of the ,blades cooperatively associated with each other.

16. A rate-of-rise thermostat comprising a closure having two sections, air Ventilating openings in one of the sections thus forming two differentially ventilated sections, thermosensitive switches located in each of said sections, means for mounting each of the said thermosensitive switches at one of their ends and the other ends being free and arranged in contacting relation with each other.

GEORGE HOWLETT DAVIS.