US2806375A

US2806375A - Thermal responsive device

Info

Publication number: US2806375A
Application number: US333707A
Authority: US
Inventors: Charles W Wood
Original assignee: Standard Thomson Corp
Current assignee: Standard Thomson Corp
Priority date: 1953-01-28
Filing date: 1953-01-28
Publication date: 1957-09-17
Anticipated expiration: 1974-09-17

Description

Sept. 17, 1957 c. w.=woo|:

THERMAL RESPONSIVE DEVICE Filed Jan. 28. 1955 INVENTOR. C HAR l. Es vv fTOFmEY United States Patent THERMAL RESPONSIVE DEVICE Charles W. Wood, Lebanon, Ohio, assignor to Standard Thomson Corporation, Dayton, Ohio, a corporation of Delaware Application January 28, 1953, Serial No. 333,707 4 Claims. (Cl. 73--368.3)

responsive device which has long life, and dependability;`

one which is easily produced and is inexpensive to construct.

Another object of this invention is to provide a thermal responsive device which is adaptable for use as a thermostatic control device or for use as a temperature ndicatng device.

Other objects and advantages reside in the construction of parts, the combination thereof and the mode of operation, as will become more apparent from the following description.

Referring to the drawing,

Figure l is a side elevational view of an `embodiment of the thermal responsive device under normal temper-A atures, with a portion of the device shown in section.

Figure 2 is a side elevational view, with a portion in section, of the preferred modification of the thermal device during temperatures higher than normal.

Figure 3 is a top sectional view of the device, taken substantially on line 3 3 of Figure 1.

Figure 4 is a perspective view of the spool portion of the device.

Figure 5 is a side sectional view of another modification of the thermal responsive device.

In the drawing, the reference numerals and 12 indicate two end plates of the thermal device, as clearly shown in Figures l, 2, and 3. These end plates are retained in position by bolts 14 and nuts 16. Each of the

end plates

10 and 12 is provided with a centrally located orifice. The orifice in end plate 10 is larger than the orifice in end plate 12. The inner surface of each end plate is provided with an annular groove. A cylinder 20 has radially disposed flange portion 18 at each end thereof terminating in annular rings 19 which are positioned in the annular grooves of the

end plates

10 and 12.

A spool 22 is firmly positioned within the cylinder 20. The spool 22 is composed of elastic material, such as rubber, or synthetic materials having the qualities of being substantially incompressible, but elastic, permitting ow of the material. Flat portions or annular flanges 24 of the spool 22 are firmly retained in and by the ends 18 of the cylinder 2i), as the flat portions 24 abut the inner surface of the

end plates

10 and 12. As clearly shown in Figures l and 2, each of the ends of the main body portion of the cylinder 20 terminates in a rib portion 21, clamping the fiat portions 24 against the

end plates

10 and 12.

A longitudinal hole 28 through the center of the spool 22 extends a portion of the length of the spool at one diameter and tapers down to a smaller diameter for the remainder of the length of the spool. An actuator 30, shown in Figure l, consists of a pin having two cylindrical portions, a larger diameter portion 32 and a smaller diameter portion 34 joined by a frustum-conical shoulder portion 36. p

The embodiments of the invention shown in Figures l and 2 are substantially the same, excepting that the actuator memberll disclosed in Figure l is different from an actuator 37 disclosed in Figure 2. The actuator 37 is a hollow cylindrical member having a tapered end and a centrally located hole throughout its length. A guide pin 38 is firmly attached t-o a lower end plate 40. The guide pin 38 extends through the cylinder 20 and through the orifice in the end plate 10. The actuator 37 slidably lits over the pin 38 and is adapted to move along the pin 3S,while moving through the orilice provided in the end plate 10. The actuator 37 of Figure 2 and the actuator 30 of Figure l are adapted to fit snugly within the/hole 28 in the spool 22.

The space between the spool 22 and the Walls of the cylinder 20 forms an annular compartment which is occupied by an expansive material 39. This expansive material may be any element or any combination of elements giving the material the physical property characteristic of a high coefiicient of expansion over a given temperature range. A material is selected to provide the desired expansion and flow characteristics over the desired temperature range for a given application.

As the temperature of the thermal device increases above normal, the initial expansion of the expansive material is small. However, as the temperature continues to rise, a temperature point is reached at which the amount of expansion per degree of temperature change greatly increases. Decrease in temperature results in contraction of the material.

The volumetric expansion of the expansive material 39 results in exertion of pressure upon the spool 22. The pressure upon the spool 22 forces the elastic material of the body of the spool 22 to move inwardly (as shown in Figure 2), tending to close the hole through the spool. Due to the fact that the elastic material of the spool 22 is incompressible, the radial, inward movement of the elastic material results in movement of the actuator, as shown by dotted lines in Figure l. The actuator moves in a direction out of the cylinder Ztl. The actuator 30 of Figure l is guided in its outward movement by the

end plates

10 and 12. This is due to the fact that the two

cylindrical portions

32 and 34 slidably fit in the orices of the end plates lil and 12. The amount of outward movement ofthe actuator is, of course, dependent upon the amount of expansion of the expansive material 39.

An actuator may be employed to operate a control device, or the actuator may be connected to an indicating device for indicating temperature. This thermal responsive device may also be employed in a dual purpose of indicating temperature while controlling temperature.

A modiication of the thermal responsive device is disclosed in Figure 5. A cup 50 retains a cylindrical elastic spool 52, having a disc type head 53. The head portion 53 of the elastic spool is fastened., as by a rib 55, within the cup 50 near the top thereof. The lower part of the body portion is retained by rib 57. Surrounding the body of the elastic spool 52 is the expansive ma terial 39. A plate 54, having a centrally located orifice therein provides a cover for the cup and aids in fastening the head portion 53 of the elastic spool 52 to the cup 50. The upper edges of the cup Sil are turned down upon the plate 54.

The elastic spool S2 is provided with a centrally located cavity extending a portion of the distance through the Y 3 elastic spool 52. An actuator 56 is adapted to slidably t within the cavity of the elastic spool 52. The movement of the actuator 56 is similar to the movement of

actuators

30 and 37. As the temperature of the expansive material 39 increases, the volumetric expansion of the expansive material Vforces ,movement inwardly .of the sides of the body o'f the-elastic spool 52, thus tending to close the internal cavity. This inward radial movement forces the actuator in a direction out of the cup 50.

'This thermal responsive device may be used ias a thermostatic control device or ,as a temperatureindica-ting device.

Although the preferred embodiment of the device has been described, it will be understood that within the purview of this invention various changes may be made in the form, details, proportion and arrangement of parts, the combination thereof and mode `of operation, which generally stated consist in a device capable of .carrying out the objects set forth, as disclosed and dened in the appended claims.

Having thus described my invention, I claim:

1. In a thermal responsive device, the combination -including a container, a spool comprising an elastic material retained within the container, the spool having a body portion, the body portion engaging opposite end Walls of the container, the body portion being provided with wall members forming a centrally located longitudinal hole therein open at one end thereof and extending a portion of the length thereof, the remainder of the body portion being solid, said remainder of vthe body portion having a greater length than the thickness of the wall members, an actuator snugly positioned within the hole in the body portion of the spool, an expansive material within the container surround-ing the body portion of the spool so that as the expansive material expands with increased temperatures thereof such force is exerted upon the body .portion of the spool that the elastic -material forming the wall members in the body portion moves inwardly tending to close the hole in the body portion of the spool, the closing action thus causing Lan extrusion action forcing longitudinal movement of the actuator in a direction from the spool.

2. In a thermal device comprising a cup shape containerj a cover member having an aperture therein closing the cup shape container, a cylindrical elastic spool within the container, each end of the spool being in engagement with internal wall surfaces of the container, the spool being provided with a longitudinal centrally located hole therein extending through only a portion of the spool and concentric with the aperture in the coverV 4 r thereof, the remainder portion of the elastic body being solid, a cylindrical actuator rod snugly tting within the cavity and slidably extending from the container through one of said enclosing walls thereof, the thickness of the wall members forming the cavity being less than the length of said remainder portion of the elastic body, an expansive material filling the space between the elastic body and the container, the expansive material being such a material that -its -v-olume changes with variations in temperature thus providing means whereby the elastic body is deformed, `said wall members forming the cavity in the elastic body being forced inwardly tow-ardY ,the longitudinal axis of the body upon expansion of the expansive material, which movement of the -wall portions causes an extrusion process and forces movement of the actuator in a direction from the elastic body, the amount of movement of the wall portions being dependent upon the temperature of the expansive material, both of the longitudinal ends of the elastic body `being in .engagement with said opposite enclosing walls of ,the Container during expansion of the expansive material.

4. In a thermal responsive device, the combination including a container, an elongate elastic body retained within the container and having ylongitudinal end surfaces in engagement with opposite end walls thereof, the elastic body having wall members extending a portion of the length thereof forming .a centrally located longitudinalcavity therein, the cavity'being .open at one end .thereof and extending a portion of the length -of the elastic body, the remainder portion of the length of the elastic body being greater than the thickness of the -wall members forming the cavity in the elastic body, an actuator rod snugly 4positioned within the cavity in the elastic body, the actuator rod extending from the elastic body and through one of said end walls of the container,an expansive material within `t-he ycontainer encircling the elastic Abody so that ,as the expansive material expands with increased temperatures thereof the expansive maf terial exerts forces upon the elastic body so that the wall members forming the cavity move inwardly tending to close the cavity, the closing movement -of the Wall members thus causing extrusion of the actuator rod forcing axial movement of the actuator rod in a direction from the elastic bod-y, said longitudinal end surfaces ofthe elastic body being in engagement with said opposite end walls of the container during expansion of the expansive material.

References Cited in the tile of this patent UNITED STATES PATENTS 2,076,406 Kern Apr. 6, 1937 2,208,149 Vernet July 16, 1940 2,241,086 Gould May 6, 1941 2,355,043 Adlam Aug. 8, 11944 2,453,851 Miller Nov. 16 1948 2,507,466 De Craene May 9, 1950 FOREIGN -PATENTS 436,836 Great Britain lOct. 18. 1935