US1852333A - Actuator for controlling devices - Google Patents

Description

April 5, 1932. PHELAN 1,852,333

' ACTUATORFOR CONTROLLING DEVICES 1 Filed April 28, 1928 vPatentedApr. 1932 I UNITED STATES PATENT OFFICE LOUIS A. Mi PHELAN, OF EIIKHABT, INDIANA, ASSIGNOB, BY MESNE ASSIGNMENTS, 'I'O MINNEAQOLIS-HONEYWELL REGULATOR COMPANY OF MINNEAPOLIS, MINNESOTA,

A CORPORATION OF DELAWARE ACTUATOR FOR CONTROLLING DEVICES Application fled April 28,

means, the latter controlling electrically operated devices or systems.

More particularly, this invention has reference to an electrically heated actuator comprising opposed bimetallic members that are interconnected whereby when the bimetallic .members are heated or cooled the bimetallic members warp or buckle away from each other or toward each other to actuate an electric switching mechanism.

The device of this invention is shown and will hereinafter be described in connection with an elecg'ical switch employing a t1ltable liquid cont-actor tube, the latter being arranged to m'ake and break an electrical circuit therethroiigh. It will be particularly noted that a maximum leverage is obtained by the actuator and that a minimum amount of space is required to house the same. A comparison may be had by referring to an ordinary electrically heated actuator comprising an elongated strip of bimetallic material which is fixed at one end, the warping of z the actuator causing the free end thereof to move the linkage mechanism of an electrical switch.

The device of the present invention obviously may be considerably shorter than the aforementioned type of actuator and further a greater amount of power may be developed in the resent device from the same amount of available thermal energy because of the greatly increased leverage. Also because of the arrangement of the elements of the actuator the degree of movement thereof may be multiplied a reat number of times for a given degree of heat as it may be desirable to obtain an actuation of the-switching mechanism of the device when a change of but a sin ledegree of temperature is recorded.

urther obj cts and advantages will hereinafter be pointed out and for a better understanding of the characteristic features of this inventlon, reference may now be had to the following description and the accompanying drawings, in which:

1928. Serial No. 278,505.

Figure 1 is a front elevational view of a switching mechanism embodying tiltable fluid contact making-and-breaking members actuated by the device of the present invention;

Fig. 2 is a perspective view of the thermally operated actuator;

Fig. 3 is a perspective view-of the various elements of the device of Fig. 2 in a spaced relation with each other;

Fig. 4 is a side elevational view of a modi- 'fied form of a thermally operated actuator embodying my invention and emplo ing a plurality of units such as is shown in ig. 2;

Fig. 5 1s a slde elevational view of a further modification of my thermally operated actuator showing the elements thereof connected together at a central point; and

Fig. 6 is a side elevational view of a still further modification of my thermally operated actuator showing the elements thereof connected at one end.

Referring now to the drawings and more particularly to Figs. 1 to' 3, inclusive, a thermally operated actuator 10 is shown comprismg a pair of bimetallic elements 11 and 12 having a resistor 13 disposed therebetween, the resistor being insulated from the bimetallic elements by means of the strips of mica 14 and 15 or by means of any suitable insulating material.

Each of the bimetallic elements 11 and 12 comprises preferably a strip of invar metal 16 which has been suitably united with a strip of brass 17 in a manner well known in the art to constitute the so-called bimetallic thermostat. The materials just recited are preferably used although it is to be understood that any two metals, intimately united over their adjacent and abutting surfaces for obtaining a movement. of one part thereof relatively to the other part under temperature changes, may be employed. It is only necessary that the two metals have different coefficients of expansion. Hereinafter one of the metals will be referred to as bein of the higher order and the other metal Wlll. be rewire 18 wound therearound in a spaced relation to form an electrical heating coil. In winding the resistance wire 18 about the core or strip of mica the wire may imbed itself in the corners of the mica and in that manner each convolution will be held in a spaced relation.

The strips of mica 14 and 15 are provided with projecting portions 19 having holes 20 formed therein for receiving binding posts 21, the ends of the resistance wire 18 being connected thereon.

The invar metal 16 is provided with ears 22 which extend beyond the confines of the brass strips 17, the corresponding ears of one of the invar metal strips being connected to corresponding ears of the other of the invar metal strips as by means of rivets. It will be noted particularly that the invar metal strips are spaced adjacent each other and that the brass strips therefor are disposed on the outer sides thereof whereby the bimetallic members 11 and 12 are opposed to each other during the actuation thereof.

In the arrangement of the bimetallic elements, in each of the following illustrations, the material of the same order of each element, is disposed adjacent each other.

In the operation of the heat responsive device 10, when an electrical current is passed through the resistance wire 18, the bimetallic elements 11 and 12 are heated and thereafter warp in a manner in which their coefficients of expansion direct. By referring to '1, it will be noted that the bimetallic members of the heat responsive device 10 are bellied or warped away from each other, those elements beiang connected at both their lower and upper en s.

In order that a specific illustration of an actual use be had, one of the bimetallic elements 12 has a screw 23 fixedly mounted thereon which is secured in any ordinary manner to an insulating post 24. The other bimetallic element 11 has a post 25 secured thereto and a pin 26 mounted in the post 25 to engage an aperture in a pivotally mounted arm 27. The free end of the arm 27 is connected by a suitable link member to a second arm 28 for actuatinga tiltably mounted mercury contactor tube 29 which latter is of the usual type and comprises a sealed container having a pair of spaced cooperating electrodes disposed in one end thereof to be bridged by a body of current conducting fluid. such as mercury, when tilted in one direction. It will be readily apparent that the heating of the bimetallic elements 11 and 12 will actuate the arm 27 to tilt the contactor tube 29. Likewise, the cooling of the bimetallic elements 11 and 12 will actuate the arm 27 to tilt the contactor 29 in a direction to change the circuit connections therethrough.

In order that the degree of movement maybe multiplied a great number of times for a given degree of temperature, a plurality of i heat responsive devices 10 are joined together as in Fig. 4, each ofthe bimetallic elements being opposed, that is, the members of similar orders of expansion being disposed adjacent each other. It will be noted that the outside metal of the element which, in the present instance, may be brass, is disposed adjacent the brass strip of the adjoining element. It has already been pointed out that the inner strips of metal, in this particular instance, the invar metal, are connected together. It is quite apparent that should the movement of one of the members be a quarter of'aninch, the movement of four such members when connected together wouldbe a full inch. It is also to be understood that the resistor 13 may be omitted from this construction when it is desirable that the operation of the actuator be controlled by the temperature of a room as is the ordinary thermometer.

In order to show the operation of the plurality of bimetallic elements, each unit 10 is connected at a central point to each other, one of the units being fastened to the insulating post 24 and the other end element being connected by means of a link 30 to an arm 31 of a pivotally mounted mercury contactor 32 whereby the expansion or contraction of the units will tilt the contactor to obtain a change of circuit connections therethrough.

By referring now to Fig; 5, the bimetallic elements 11 and 12 are centrally connected as by means of a rivet 33, one end of the element 12 being pivotally connected to a bracket 34 and the other end thereof being slidably connected to a bracket 35. The element 11 is pivotally connected to one end of the link 36, the other end of the element being slidably connected to the other end of the link 36. The warping of the bimetallic elements 11 and 12 move the link 36 away from the insulating post 24 to which the brackets 34 and 35 are secured to actuate a contactor tube 37.

By referring now to Fig. 6, a still further modification is shown in which the bimetallic elements 11 and 12 are connected together at one end, that end being secured to an insulating post 24. The free end of the bimetallic element 12 is slidably connected to a bracket 38 which is fixedly mounted on the mounting plate on which the insulating post 24 is fixedly mounted and the free end of the bimetallic element 11 is connected as by means of the link 39 to an arm 40 of a tiltably mounted mercury contactor tube 41. y

In each of the modifications just described, the actuation of the bimetallic elements is multiplied in order to obtain a maximum leverage in a. minimum amount of space. As a result of this invention, a maximum amount of power may be developed in a device which will occupy but a minimum amount of space. due to the arrangementsof the elements entering into the construction obtaining a maxiroom tem erature ma be the ener for controlling the actuation oi the device where it is not desirable to control the same by means of electrical energy in the electrical circuit in which the device may be operated.

While but a single embodiment of this invention is herein shown and described, it is apparent that various modifications "iElIGTGO'i may be apparent to those skilled in the art without departing from the spirit and scope of this invention, and therefore, the same is to be limited only by the scope of the prior art and the appended claims.

. I claim: I

1. A heat responsive device comprising a plurality of side-by-side bimetallic members, the materials of each member having different coefiicients of expansion and the material of the several members possessing simi-' lar coefiicients of expansion, being disposed adjacent each other, said members being mechanically attached to one another in order that their several distortions will be additive, and an electric heater independent of said members but interposed therebetween for distorting said elements.

2. In combination with a mercury con-- tactor adapted to control an electric circuit, of a heat responsive actuator therefor com prising a pair of opposed bimetallic elements that are attachedto each other to supplement the degree of distortion of one of said elements with the degree of distortion of the other of said elements, an electric heatingelement interposed between said elements, and means for imparting to said contactor the resultant distortion of both elements ofsaidactuator.

3. In combination with a tiltably mount ed mercury contactor, of a heat responsive" actuator therefor comprising a plurality of opposed bimetallic elements that are attached to each other to supplement the degreeof distortion of one of said elements with the degree of distortion of the other, of said elements, an electric heater for in .fluencing said bimetallic elements, and means interposed between said contactor and said actuator for imparting to the former the resultant movement arising from the to tilt said contactor. i

4. In combination with a mercury rpntactor adapted to control an electric circuit, of a heat responsive actuator therefor comprising a plurality of opposed flexible bimetallie elements that are attached to each'other to supplement the degree of distortion of one of said elements withthe degree of distortion of the othei'lqf said elements, an'eleotric heater interposed between at least two of said elements and independent-thereof latter" cent to each other, ears projecting from each whereby said elements may become distorted loy the heat generated in saidelectric heater, means responsive to the distortion of said elements for imparting to said contactor the resultant distortion oi all of said elements.

5'. In comhination with a mercury contactor adapted tocontrol an electric circuit, of a heat responsive actuator therefor co1nprisinga plurality of side-by-side and op posed bimetallic elements that are attached to eachother to so pl-ement the degree of distortion of one or said elements with the degree of distortion oi the other of said elements, an electric heater interposed between at least two oi said elements and independent thereof whereby said elements may flex without being mechanically restrictedby said electric heater, and means interposed between said contactor and said actuator for imparting to said contactor the resultant distortion of all of said elements.

6. In combination with a tiltably mounted mercury contactor adapted to control an electric circuit, of a heat responsive actuator therefor comprising a plurality of opposed bimetallic elements that are attached to each other to supplement the degree of distortion of one of said elements with the degree of distortion of the other of said elements, an

the 'materials of each element having different coefficients of expansion and the material of the elements possessing similar coefficients of expansion being disposed adjacent to each other, ears projecting from each of said elements, said ears being integral with only one of the materials comprising said elements, means for attaching said elements to each other through the medium of-said ears, and an electric heater independent of said elements for distorting them.

8. A heat responsive device comprising a plurality of side-by-side bimetallic elements, the materials of each element having dif ferent coeificients of expansion and the ma terial of the elements possessing similar coeflicients of expansion being disposed adjaof said elements, said ears being integral with only one, of the materials comprising said elements, and means for attaching said elements to each other through the medium of said ears.

In Witness whereof l have hereunto subscribed my name.

LUUIS A. M. PHELAN.

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