US1146637A - Thermostat. - Google Patents

Description

R. F. MASSA.

THERMOSTAT. APPLICATION FILED NOV. n, 1913.

Patented July 13, 1915.

I UNITED STATES PATENT OFFICE. v

3031mm 1'. MASSA, or ram: WAYNE, INDIANA, ASSIGNOR TO 11'. w. JOHNS- MANVILLE COMPANY, A CORPORATION or NEW YORK.

To all whom it may concern Be it known that I, RoBnRT F. MASSA,- a citizen of the United States of America, residing at the city of Fort Wayne, Allen county, State of Indiana, have invented certain new and useful Improvements n Thermostats, of which the following is a speclfication.

My invention'relates to apparatus for automatically operating temperature control ling devices, and isspecificallydeslgned to produce a sensitive and positlvely acting thermostatic mechanism for alternately opening and closing an electric circuit. The usual form of device for th1s. purpose, 1n which a switch memberis moved solely by a thermostatic member, is defective in that the action is slow and hesitating, and responsive only to considerable variations of temperature. The vacillating action of the device at critical temperatures produces an in ur1- ous sparking at contact points, and when magnets have beep used to make the contact iy/flfey have interfered action more pos1 with the sensitiveness of'the apparatus, the

movable armature freezing to the magnet in certain positionsof the thermostat.

My invention overcomes these diflicultles Y by a special arrangement of magnetic field,

armature and contact members such as illustrated in the accompanying drawing, whichdiagrammatically illustrates the best form of apparatus for embodying my mventlon at present known to me. Referring to the drawing, A,.1s a thermostatic member formed in the usual way of two elastic strips of metals having different coefficients of expansion under heat, such as steel and brass, welded or otherwise fastened together and coiled into a spiral. The lnner endof the spiral is rigidly fastened at B,to a non-conducting base, such as the slate slab C. The outer and free end of the spiral carstrip G, are attached. H, is a contact member formed of any non corrod1ng metal, car- ,ries a bar D',-to the outer end of which a soft iron armature E, and a light spring ried by spring G.

F, is a magnet, preferably a permanent magnet of horse shoe form, held to base C, by clips L, L, so that the armature E, Wlll move toward. and from the center of the magnetic field of force as the coil A, unwinds or winds up under the action of varying temperature.

Specification of Letters Patent.

THERMOSTAT.

Patented July 13, 191 5.

J is a brass screw adjustably mounted in a pm, or other support on-base C, and havlng a t1p K, of material similar to H.

M, represents a binding screw set in base C, and electrically connected to movable contact member H, as by a wire X, indicated in dotted lines extending under base C, to pin B. Another binding screw N, is electrically connected to stationary contact member K, as by wire Y, indicated in dotted lines, extending under base 0, to pin I. Any suitable work circuit is indicated at W, includinga source of current, Q,.and a translating device, such as motor S. 7

Such being the. arrangement of the apparatus, the operationis as follows Assuming that S, is a solenoid having a core R, normally pulled out by spring T, and connected to a switch .U, which controls the motor circuit of (not shown) and that-said refrigerating machine controls the temperature in the room where the thermostatic member A, is. placed, the supporting pin B, is soadjusted that when the desired .temperature exists in the room, the armature. IE, will be located in the weaker outer zone of the magnetic field created by the magnet F and the contacts H, and K, will be separated. The circuit W, will thus be open and the core R, of solenoid S, extended by spring T, to open the switch U. The thermostatic. member A, is then so adjusted that upon a slight rise of temperature the coil A, will unwind (or expand) sufficiently to move armature E, into the more intense zone-of the magnetic field of varied intensity produced by magnet F. Thereupon the increased magnetic attraction promptly'pulls the armature farther toward the magnet until contact members H, and K, meet and close the circuit. The solenoid S, is then thrown into operation to close the switch and the refrigerating apparatus (not shown) reduces the temperature to the predetermined point. Thereupon the elastic tension of the spiral A, which has been produced by the flexing of the spiral when the armature was pulled over by the magnet, is increased by its tend ency to contract under the. influence of the lower temperature, and when the magnetic attraction is overpowered by this elastic pull of spiral A, and that of the spring G,

the armature moves outv into the weaker portion of the field. Thereupon theelastic stress promptly overcomes what is left of the magnetic pull, and the armature moves-- quickly to a farther distance suflicient separate contacts H, and K. At the crit1- cal temperature there is a wavering or vacillating of the armature E, butno sparking occurs as the spring G, keeps the contacts together. Before the armature moves. far enough to, open the circuit it has reached such a weak zone of the magnetic field that the" elastic tension of A, pulls it quickly away and the break between the contact members is quick and positive. When the circuit is opened the solenoid becomes dead,

spring R, pulls the core T, out, opening switch U, andzthe refrigerating machine I stopsuntil a slight rise of'temperature again causes the armature to approach the center of intensity of the magnetic field and the operationfirst above described is repeated.

With my invention 1' am able to reduce the range of temperature variation to half a degree Fahrenheit, and by eliminating all Y sparking I produce a thermostat which will operate indefinitely 'withoutsubstantial deterioration. .As the armature never qulte touches the magnet poles, there is no op- -G, the degree of sensitiveness of the instrument'can be varied so that it'will respond to a minimum changeoftemperature, or

permit a widerflvariation without setting I the apparatus in motion. Alsov adjustment of the relative positions of the magnet and the thermostatic member, determines the temperature at which the apparatus will operate.

.Of course other forms of magnet or magnetic field, thermostatic'members and contact members, could be substituted forthose illustrated, without necessarily departing from the principle of my invention as above explained. So long as a magnet and armature, one of which is fixed and the other movable, are employed with a spring contact to prevent chattering, the other elements of the structure illustrated may be modified in many ways to suit varying conditions or requirements.

Having described my invention, I claim: 1. In an automatic temperature controlling device the combination of a flexible, elastic thermostatic member, rigidly fastened at one point, an armature carried on 2 within the line of travel of the armature when moved by the effect of varying temsaid thermostatic-member at another point, a magnetic field of varied intensity located perature on the thermostatic member, a contact member located near the point. of

said thermostatic member at another point,

Y tact member located near the point of great: I 'est' intenslty of the field, a cooperating greatest intensity of the field, a cooperating contact member carried by the thermostatic member, and an electric circuit connected to said contact members. I

- 2. In'an automatic temperature controlling device the combination of a flexible, v elastic thermostatic member, rigidly. fastened at one point, an armaturecarried on a magnetic fieldof varied intensity located within the line of travel of the armature when moved by the effect of varying temperature onthe thermostatic member, a conspring supported contact member carried'by the thermostatic member, and an electric cir- I cuit connected to said contact members.

3. In an automatic temperature control-iv ling device the combination of a s irallyfiggg coiled thermostatic member held rigidly at that end which forms the center of the coil, an armature and a yielding contact member carried by the free end of the thermostatic member, a permanent magnet so located that the armature approaches its poles when the thermostatic member moves in one direction, an adjustable stationary contact member so located that the other contact meme ber touches it-when the armature nearly touches the magnet poles, andan electric circuit the terminals of whichjare connected to said contact members. i

4. In an automatic temperature control ling device the'combination with a thermostatic'member adapted to be flexed'b varia-ftions of temperature and rigidly astened at one end, of-an armature and a contact member carried by the movable portion of said thermostatic member, a stationary'magnetic field of varied intensity into and ,out of which'the armature may be carried by I flexure of the. thermostatic member, a stationary contact member so located as to] touch the moving contact member onl when the armature a proaches the point 0 greatest intensity 0 the magnetic field, and an electric circuit in which said contact 'members are included. i

5. In an automatic temperature controlling device the combination of a magnetic field of varied intensity, a movable arma-T ture, a thermostatic member adapted to; move saidv armature toward and from the center of intensity of said field, a movable no contact member operatively connected to said armature, a stationary contact member so located as to 'touch the movable contact. I member onlywhen the armature approaches] the center of intensity of said field, and an electric circuit in which said contact mem- V bers are included.

6. In a thermostatic device for control l :ling an electric circuit, the combination of a stationary magnet, a movable thermost'ati-f tact member, and an elastic contact member carried by the magnet and adapted to strike the stationary contact member when the armature approaches the magnet poles, and prevent its further motion toward and contact with said poles.

8. In an automatic temperature controlling device the combination of a thermostatic member, an armature controlled by said thermostatic member, a magnetic field of varied intensity located in the line of travel of the armature when moved by reason of temperature changes, a contact member independent of the thermostatic element,

and a cooperating contact member controlled by the-armature, at least one of said contact members being elastically mounted with reference to both magnet and armature.

9. In an automatic temperature controlling device the combination of a magnet and armature movable one with reference to the other, a thermostatic member having a motion controlling connection with-one of the two first'mentioned elements, and two. contact members, one of which is movable by the thermostatically controlled member, at least one of said contact members being elastically mounted with reference to both magnet and armature.

10. In an automatic temperature controlling device the combination of a magnet and armature movable one with reference to the other, a thermostatic member having a motion controlling connection with one of the two first mentioned elements, and means for adjusting the normal relative positions of said thermostatic member and the stationary element, together with two contact members,

one of which is movable by the thermostatic member, at least one of said contact members being elastically mounted with reference to both magnet and armature.

11. In an automatic temperature controlling device the combination of a magnet and armature movable one with reference tothe other, a thermostatic member having a motion controlling connection with one of the two first mentioned elements, and means for adjusting the normal relative positions of said thermostatic member and the stationary element, together with two contact members, one of which is elastically mounted on the thermostatic member, while the other has an adjustable stationary mounting.

ROBERT F. MASSA.

Witnesses: V

KATHERINE MCCABE, ELLA L. BEVERFORDEN.

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