GB2136566A - Temperature adjusted potentiometer - Google Patents

Abstract

A first housing (1) is coupled with a second housing (2); an adjustable setting member (3) is in the first housing (1); a float adjusting rod (4) is in the second housing (2) with one end extending into the first housing (1); a coiled bimetal strap (5) is in the first housing (1) with one end fixed on the shaft surface of the float adjusting rod (4) and the other connected to the adjustable setting member (3) through a guide bar (32) secured thereto; and a variable resistor (6) is in the second housing (2) with the sliding piece (61) connected to the float adjusting rod (4). By adjusting the adjustable setting member (3), the output potential of the variable resistor (6) can be set. With the expansion and contract of the coiled bimetal strap (5) following temperature changes, the float adjusting rod (4) will be caused to rotate so as to make the variable resistor (6) change its output potential. <IMAGE>

Description

SPECIFICATION Automatic and free thermo potential regulating apparatus This invention relates two an automatic thermo potential regulating apparatus, particularlyto a thermo-control arrangement with a bimetal member coupled with a variable resistor through a float adjusting device so that whenever a temperature changetakes place, a relative output of regulated potential will be effected therewith.

General temperature regulation should possess two kinds of performance: 1) In order to maintain the substantive temperature at a certain set-temperature value, continuous regulation should be performed. In other words, when the ambient temperature suffers a sudden change, the process of heating and cooling must be done in an enclosed feedback type. 2) When the substantive temperature goes higher or lower than the upper and lower limit of the set-temperature value, an "on" and "off" function can be effected along with the temperature change thereof.

The prior-art temperature regulating devices are usually divided into three type: 1) the make-and-break control type; 2) the float control type; and 3) the ratio control type. All of the three types use the preset temperature value for achieving the regulating purpose through intermittent on-and-off operations as described in 2) above. The common defect shared by these prior-art temperature regulating devices is that once the structural design of the temperature regulating device is finished, the temperature setting is fixed thereat, so that, not only the fixed temperature setting cannot be changed, but also the device lacks common utility for various thermo-control regulating operations.

It is accordingly a primary object of this invention to provide an automatic and free thermo potential regulating apparatus with which the ambient temperature change will cause a varied output potential for controlling operations, and, above all, the output potential can be adjusted as required along with the temperature conditions.

It is another object ofthis invention to provide an automatic and free thermo potential regulating apparatus with common utility performance for various temperature regulating operations, particularly suitable for that with low temperature range and high sensitivity functions.

It is still another object of this invention to provide an automatic and free thermo potential regulating apparatus with simple structure for reducing manufacturing cost and facilitating installations.

According to the present invention,these and other objects are achieved by providing an automatic and free thermo potential regulating apparatus, which is characterized by: a first housing body; a second housing body coupled with the first housing body on one side; an adjustable setting member installed in the first housing body with one end received inside and the other extending outside; a float adjusting rod movably disposed in the second housing body at one end and the other extending into the first housing body for being rotatably engaged with the inside end of the adjustable setting member; a coiled bimetal strap installed in the first housing body with one end fixed on the float adjusting rod and the other connected to the setting adjustable member through a guide bar vertically secured thereto; and a variable resistor installed in the second housin body with the sliding piece connected to the float adjusting rod and the terminals extending outward therefrom; so that, by the expansion and contract of the coiled bimetal strap following the temperature change, a varied output potential of the variable resistor will be produced through the turning of the float adjusting rod. Besides, by adjusting the setting adjustable member with respect to the variable resistor, temperature setting can be made any time as the condition may require.

These and other objects, advantages, and salient features of the present invention will become apparent to those skilled in the art from the following detailed description of a preferred embodiment when read in conjunction with the accompanying drawings, in which: Figure lisa sectional view of a preferred embodiment of an automatic and free thermo potential regulating apparatus according to this invention; Figure2 is an illustration of a type ofthe variable resistor used in the preferred embodiment shown in Figure 1; Figure 3 is a structural illustration of a coiled bimetal strap in the preferred embodiment shown in Figure 1; and Figure 4 is a torsional illustration of the coiled bimetal strap shown in Figure 3.

Refering to Figure 1, there is shown a preferred embodiment of an automatic and free thermo potential regulating apparatus according to this invention, which apparatus comprises in combination: a first housing body 1; a second housing body 2 coupled with the first housing body 1 on one side; an adjustable setting member 3 installed in the first housing body 1 atthe otherside; a float adjusting rod 4 disposed in the second housing body 2 at one end and the other end extending into the first housing body 1; and a variable resistor 6 disposed in the second housing body 2. The first housing body 1 is in a hollow and drum-like shape with a central opening respectively formed in the oppos sides and a plurality of ventilation holes 11 separately formed in the other side.The second housing body 2 is also in a drum-like shape corresponding to that of the first housing body 1 with a central opening respectively formed in the opposing sides and a plurality of holes available in the other side. The adjustable setting member 3 has a proper portion received in the first housing body 1 with a conical notch 31 formed atthe end, and a guide bar 32 vertically fixed on the shaft surface thereof at one end and the other end being free thereat. The float adjusting rod 4 has a proper portion movably received in the first housing body 1 with a conical pointed end pivotally engaged in the notch 31 of the adjustable setting member3, and an elastic pressure plate 21 fixedly disposed on the outer side of the second housing body 2 for keeping the other end of the float adjusting rod 4 in position.

As shown in Figure 2, the variable resistor 6 (of which the structure is the same as that of conventional variable resistors) includes a sliding piece 61 rotatably coupled with a resistive member 62 to which a pair of terminals A and B are separately connected for providing output signalstherefrom. The sliding piece 61 has a central opening 610 formed therein for being coupled with the end portion of the float adjusting rod 4 so as to be turned therewith in effecting variation ofthe resistance value and transfered through the terminals A and B thereof.

Shown in Figure 3 is the arrangement of the coiled bimetal strap 5, of which the inner end is fixed on the shaft of the float adjusting rod 4, and the external end secured at the free end of the guide bar 32.

Referring to Figures 2,3 and 4, when the ambienttemperature runs high,the coiled bimetal strap 5 sta rts to expand and stretch therefrom (as shown by the dotted arrowhead in Figure 3). Since the external end of the coiled bimetal strap 5 is secured at the free end of the guide bar 32 which is fixed at the end portion of the adjustable setting member 3 where the structure bears more gravity and friction resistance than that of the float adjusting rod 4, the external end of the coiled bimetal strap 5 can be therefore regarded as being unmovable thereat in this respect. Accordingly, once the coiled bimetal strap 5 expands therefrom because of temperature change, the inner end thereof will forcethe float adjusting rod 4to rotate counterclockwise.In this connection, the moving angle, movement and the amplitude of torsion of the coiled bimetal strap 5, together with the float adjusting rod 4, are shown in Figure 4, and their relationships are as follows: As an example with a Japanes made BH-2 type bimetal strap, the thickness is 0.5 mm; length: 200 mm; and the temperature varying range: 50"-250"C; while, the bending angle: A = 360 KTL = 360x11x(250-50)x200=100.9" If the coiling radius (r) ofthe bimetal strap is: r = 20 mm; amplitude = 10 mm; and the temperature difference = 1"C; the torsion moment (M) of the bimetal strap will be: M = tKETwt2]/6 = P x r M x [11 x 16000 x 10 x(0.5)D]/6 = 106 = 0.0735kg-mm and the torsional force is: P = 0.0735/20 = 2.79.

From the above example, it is understood that when bimetal strap 5 receives 1"C change ofthetemperature, it will produce 1" change of the bending angle which, in turn, will provide a torsion to drive the float adjusting rod 4 to rotate thereabout. As the float adjusting bar 4 is coupled with the sliding piece 61 of the variable resistor 6, the rotation thereof will change the resistance value and produce a varied signal to be transfered therefrom through the terminals A and B.

Similarly, when the ambient temperature drops, the coiled bimetal strap 5 will contract therefrom, causing the float adjusting rod 4to rotate clockwise and provide a varying signal to be transfered through terminals A and B of the variable resistor 6.

In addition, ifthe user intendsto setthe output potential ofthe terminals Aand B ofthe variable resistor6, he simply adjust the adjustable setting member 3 in making the guide bar 32 push or pull against the coiled bimetal strap 5 so as to rotate the float adjusting bar 4 and produce the required signal to be set as the output potential of the variable resistor 6.

As a practical example, when the preferred embodimentofthis invention is applied on an electric fan, effect is as follows: Ifthe using temperature ofthe electric fan ranges between 25'-31'C, according to the formular of material as illustrated in the preceding paragraph, the bending angle = 3; the average temperature change = 1"C; and the variation of bending = 0.5 . In practice, the sensitivity of this preferred embodiment can detect the temperature change down to 0.1"C. Therefore, this embodiment can satisfy the adjusting requirement of the electric fan. As to the amplitued of the torsinal force, it completely depends upon the specification of the material, and has nothing to do with the temperature condition thereof.Thus, setting of the embodiment can be made in advance for the electric fan to start running at a set indoor temperature (C). In making the setting thereof, first,turn the adjustable setting member3 so as to make the coiled bimetal strap S follow the turn and causethe float adjusting rod 4to rotate therefrom in obtaining an output of resistance signal attheterminals A and B equal to the signal output at25 C. Upon receiving this signal control, the electric fan will startto run, and the coiled bimetal strap 5 will maintain a set bending angle thereat.

When the indoor temperature goes up more than 25"C, the coiled bimetal strap 5 will expand, and the bending angle is increased thereat, causing the float adjusting rod 4to rotate togetherwith the sliding piece 61 ofthe variable resistor 6. As a result, a varied signal thereofwill be output from the terminals A and B, making the electric fan adjusted to increase the revolution speed accordingly.

If the indoor temperature goes down below the set range, the revolution speed of the electric fan will also follow the variation signal and become decreased thereat.

Similarly, when the indoor temperature drops far below 25 C, by the action of the coiled bimetal strap 5, a varied signal will be output from the terminals A and B and cause the electric fan to automatically stop running thereat.

Therefore, with the preferred embodiment of this invention, optimum temperature setting can be made in any application. If the actualtemperature change occurs on a sudden but still confines to the upper and lower limits of the set range, a successive regulating of the temperature will be effected through the variation of the coiled bimetal strap 5; while, if the actual temperature change is beyond the upper and lower limits of the set range, an output signal will be obtained to automatically effectthe "on" and "off" functions of the equipment thereof.

Moreover, the preferred embodiment according to this invention can be applied to other appliances requiring thermo-control regulations such as refrigerator, air conditioner, indoortemperature regulators, etc., for effectively accomplishing the purpose of free thermo control and automatic "on" and "off" operations thereof.

While this invention has been illustrated and described by means of a specific embodiment, it is to be understood that numerous changes and modifications may be made therein without departing from the spirit and scope of the invention as defined in the appended claims.

Claims (5)

1. An automatic and free thermo potential regulating apparatus characterized by: a first housing body in a hollow and drum-like shape with an opening separately formed in the opposing sides and a plurality of ventilating holes provided in the other side; an adjustable setting member installed in said first housing body through said opening in one side; a second housing body in a hollow and drum-like shape with an opening separately formed in the opposing sides and a plurality of ventilating holes provided in the other side coupled with said first housing body on one side; a float adjusting means rotatably installed in said second housing body, and pivotally connected to said adjustable setting member in said first housing body; a bimetal means connected between said adjustable setting means and said float adjusting means; and a variable resistance device installed in said second housing body with the sling piece thereof fixed on said float adjusting means and the resistive element thereof connected to an output terminal, so that, by the rotation of said float adjusting means, automatic potential regulation along with the temperature change can be effected accordingly.

2. An automatic and free thermo potential regulating apparatus according to Claim 1 wherein said adjustable setting member is characterized by including: a shaft portion adjustably received in said first housing body with a conical notch formed at the end; an adjustable portion extending outward from said first housing body in the same axile line with said shaft portion; and a guide bar vertically secured to said shaft portion at one end and the other end fixed to the external end of said bimetal means.

3. An automatic and free thermo potential regulating apparatus according to Claim 1 wherein said float adjusting means is characterized by including a float adjusting rod with a conical pointed end pivotally engaged with said conical notch of said adjustable setting member, and the other end movably held in position by an elastic pressure plate secured on said second housing body.

4. An automatic and free thermo potential regulating apparatus according to Claim 1 or 2 wherein said bimetal means is characterized in that a coiled bimetal strap is arranged in such a way that the inner end is fixed on the shaft portion of said float adjusting means while the external end secured at the free end of said guide bar.

5. An automatic and free thermo potential regulating apparatus substantially as hereinbefore described with reference to the accompanying drawing.