WO2006083074A1

WO2006083074A1 - Temperature control switch

Info

Publication number: WO2006083074A1
Application number: PCT/KR2005/004269
Authority: WO
Inventors: Poung Kun Lee; Soo Kyung Ahn; Sung Gun Lee
Original assignee: Chumdan Enpla Co., Ltd.
Priority date: 2005-02-01
Filing date: 2005-12-13
Publication date: 2006-08-10
Also published as: KR100673091B1; KR20060088351A

Abstract

Provided is a temperature control switch. The temperature control switch includes: a base case; a bellows member connected to a charging line expanding and contracting in the base case; a push bar disposed above the bellows member to elevate according to the bellows member; an off-screw having one end connected to the push bar with a spring, and having another end connected to the base case so as to control a position of the push bar; a first and a second terminal each having one end fixed in the base case; an operating member having one end fixed to an one end of the first terminal and other end selectively contacting an one end of the second terminal; and an on-screw fixed to the base case for pressing the other end of the operating member to adjust a contact point with the one end of the second terminal.

Description

Description TEMPERATURE CONTROL SWITCH

Technical Field

[1] The present invention relates to a temperature control switch, and more particularly, to a temperature control switch that opens and closes an electrical circuit of a refrigeration or heating system.

Background Art

[2] Temperature control switches, often referred to as thermostats, are used to maintain the respective environments in desired temperature ranges in apparatuses requiring temperature control, i.e., refrigerators, air conditioners, water cooler/heaters, vending machines, water dispensers and freezers.

[3] FlG. 1 is an exploded perspective view of a conventional temperature control switch.

[4] As shown in FlG. 1, a conventional temperature control switch includes an operating unit for sensing and controlling the temperature of an environment, and a switching unit for opening and closing a contact point of an electrical circuit in response to the operating unit. The operating unit 10 is installed in a first case 10 and the switching unit 20 is installed in a second case 20. The first case 10 and the second case 20 are combined together as the conventional temperature control switch.

[5] The operating unit in the first case 10 includes a bellows member 11 into which a target substance, i.e., coolant such as Freon gas, for measuring temperature thereof enters, a rotating member 12 rotatably installed on the first case 10 to rotate according to the expansion and shrinkage of the bellows member 11, a spring 14 for elastically biasing the rotating member 12 in one direction from a plate 13, an off-screw 15 joined to the plate 13 and coupled to one end of the spring 14, and a cam member 16 for shifting a protrusion 13a of the plate 13 along a cam curve. Such an operating unit is operated as follows. When the bellows member 11 expands, the bellows member 11 pushes the rotating member 12 upwards and the rotating member rotates in one direction. On the contrary, the rotating member 12 is returned to an original position by a restoring force of the spring 14 when the bellows member 11 contracts. While the rotating member 12 are rotating and returning, an operating protrusion 12a installed on the rotating member 12 presses and releases the switching unit in the second case 20 for ON/OFF control.

[6] The off-screw 15 is used to set a temperature for turning off the switching unit. The off-screw 15 is tightened or loosened to change an initial position of the rotating member 12. Accordingly, the temperature to turn off the switching unit is adjusted. [7] The switching unit in the second case 20 includes a moving contact point piece 21 elastically shifting when the operating protrusion 12a presses, a fixed contact point piece 22 selectively contacted to the moving contact point piece 21 when the moving contact point piece 21 shifts, and an on-screw 23 for adjusting an initial position of the fixed contact point piece 22.

[8] The switching unit is operated as follows. When the operating protrusion 12a pressurizes the moving contact point piece 21, the moving contact point piece 21 contacts the fixed contact point piece 22, whereby current passes through the moving contact point piece 21 and the fixed contact point piece 22. When the operating protrusion 12a depressurizes the moving contact point piece 21, the moving contact point piece 21 returns to its original position and the moving contact pint piece 21 is separated from the fixed contact pint piece 22.

[9] The switching unit also includes a U-spring 24. The U-spring 24 functions like a toggle switch. That is, the U-spring 24 makes sudden shift of the moving contact point piece 21 in the shifting direction thereof when the moving contact point piece 21 exceeds a predetermined threshold point. The on-screw 23 is used to set a point of turning on the current, that is, an on-point of current. If the on-screw 23 is screwed, the initial position of the fixed contact point piece 22 changes and thus the on-point of current is adjusted.

[10] The operation of the conventional temperature control switch will be described hereinafter.

[11] When the temperature of the substance in the bellows member 11 is changed, the bellows member 11 expands or contracts, accordingly. If the bellow member 11 expands, the expanded bellows member 11 rotates the rotating member 12, and the rotated rotating member 12 shifts the operating protrusion 12a to press the moving contact point piece 21 in the second case 20. Then, the pressurized moving contact point piece 21 is contacted to the fixed contact point piece 22, and thus, the current passes through the contact of the moving contact point piece 21 and the fixed contact pint piece 22. On the contrary, if the bellows member 11 contracts, the rotated rotating member 11 returns to the original position and the operating protrusion 12a de- pressurizes the moving contact point piece 21. As a result, the moving contact point piece 21 is separated from the fixed contact point piece 22 and the current is interrupted to flow. Such a mechanism controls ON/OFF operation of the current flow. The on-screw 23 and the off-screw 15 are used to adjust the initial on/off points. Also, a user can manually control the ON/OFF operation by turning the cam member 16. If the user turns the cam member 16, the plate 13 is shifted by the cam curve and the rotating member 12 connected to the plate 13 and the spring 14 moves thereby. As a result, the current flow is controlled manually. [12] As described above, the operating unit and the switching unit are separately installed in the first case 1 and the second case 2, respectively. Then, the first case 1 and the second case 2 are assembled together to configure the conventional temperature control switch. Therefore, it is very complicated to assemble the first case 1 and the second case 2 with the large number of components. Namely, the operating unit including the bellows member 11, the rotating member 12, the plate 13, the off- screw 15 and the cam member 16 is installed in the first case 10 and the switching unit including the fixed contact 22, the moving contact point piece 21, the on-screw 23 and a terminal member 25 is installed in the second case 20. Then, the first and second cases 10 and 20 are assembled together.

[13] Since the conventional temperature control switch is manufactured by separately installing the large number of components in the first case and the second case and assembling the first case and the second case together, it is very difficult to manage the large number of components and to perform the assembling operation thereof. Therefore, the manufacturing cost increases, and the productivity is reduced. Disclosure of Invention Technical Problem

[14] It is, therefore, an object of the present invention to provide an improved temperature control switch having a simple structure for sensing a temperature and switching based on the sensed temperature. Technical Solution

[15] In accordance with one aspect of the present invention, there is provided a temperature control switch including: a base case forming an interior storage space; a bellows member installed inside the storage space and connected to a charging line of a heat medium gas that expands and contracts according to a temperature change; a push bar disposed above the bellows member to elevate in the storage space according to an expansion and contraction of the bellows member; an off-screw having one end connected to the push bar with a spring being interposed between the one end and the push bar, and having another end connected to the base case so as to control a position of the push bar by turning the off-screw; a first terminal and a second terminal each having one end fixed in the storage space of the base case; an operating member shifting with the push bar, and having one end fixed to an one end of the first terminal and other end selectively contacting an one end of the second terminal; and an on- screw fixed to the base case for pressing the other end of the operating member to adjust a contact point with the one end of the second terminal.

[16] The temperature control switch may further include a mounting bracket having a central portion connected to the cam member and both end portions connected to an external device. Advantageous Effects

[17] A temperature control switch according to the present invention has a simple structure by appropriately disposing and assembling essential components for measuring temperature and controlling a switch in a single base case. Therefore, the overall number of components is reduced and the assembly process is simplified.

Furthermore, the part maintenance becomes easier and the productivity is improved.

Moreover, the temperature control switch becomes lighter and thus more manageable.

Brief Description of the Drawings [18] The above and other objects and features of the present invention will become apparent from the following description of the preferred embodiments given in conjunction with the accompanying drawings, in which: [19] FIG. 1 is an exploded perspective view of a conventional temperature control switch; [20] FIG. 2 is an exploded perspective view of a temperature control switch according to an embodiment of the present invention; [21] FIG. 3 is a sectional view of a temperature control switch according to an embodiment of the present invention; [22] FIGS. 4 and 5 are perspective views of the temperature control switch in FIG. 2 for describing ON/OFF operations thereof; and [23] FIGS. 6 and 7 are perspective views of the temperature control switch in FIG. 2 for describing an adjustment operation of on/off points.

Best Mode for Carrying Out the Invention [24] Other objects and aspects of the invention will become apparent from the following description of the embodiments with reference to the accompanying drawings, which is set forth hereinafter. [25] FIG. 2 is an exploded perspective view of a temperature control switch according to an embodiment of the present invention, and FIG. 3 is a sectional view of a temperature control switch according to an embodiment of the present invention. [26] Referring to FIGS. 2 and 3, the temperature control switch according to the present embodiment includes a base case 100 configured of an upper cover 102 and a lower cover 104. The base case 100 houses all components that perform all of the functions of the conventional operating unit and switching unit. [27] As described above, in the related art, the operating unit and the switching unit are separately manufactured with corresponding components in different cases 10 and 20 in FIG. 1 and the cases 10 and 20 are assembled to manufacture the conventional temperature control switch. Unlikely to the conventional temperature control switch, all the components needed to measure temperature and perform the on/off switching function are installed in the base case 100 and the base case 100 is assembled with a case cover 101 in the temperature control switch according to the present embodiment.

[28] The structure of the temperature control switching according to the present invention will be henceforth described in more detail. At first, a bellows member 106 coupled in the lower cover 104 is disposed in the lower portion of the storage space of the base case 100. The bellows member 106 is connected to a charging line 108 for a heat medium gas such as Freon. When the heat medium gas expands or contracts according to a change in temperature, the bellows member 106 expands or contracts accordingly.

[29] A numeral reference 105 denotes a bottom holder for firmly cohering the bottom portion of the bellows member 106 to the a lower cover 104 in order to prevent the bellows member 106 from being shifted downwardly when the bellows members 106 expands or contracts in accordance with the heat medium gas.

[30] A push bar 110 is disposed above the bellows member 106. The lower portion of the push bar 110 contacts the upper surface of the bellows member 106, and the upper portion of the push bar 110 has an interposed spring 112 and is connected to an off- screw 114 attached to the upper cover 102. The off-screw 114 is joined with a nut 11 having a screw thread so that the off-screw 114 is allowed to be rotated in the nut 11 along the screw thread formed in the nut 111, but not to be moved upward. Conversely, the nut 111 is installed in a guide portion 140 to move vertically, but not to be rotated.

[31] If the off-screw 114 is tightened, the nut 111 moves upward along the threads of the off-screw 114, and the moved nut 111 pulls the spring 112 connected to the push bar 110. Therefore, the push bar 110 moves upward. On the other hand, if the off-screw 114 is loosened, the nut 111 moves downward along the threads of the off-screw 114, and the moved nut 111 pushes the spring 112 downward. Accordingly, the push bar 110 moves downward. Also, even if the bellows member 106 expands or contracts, the push bar 110 rises and falls only within the tension range of the spring 112.

[32] The push bar 110 has an operating member 116 that forms a quick operating tension plate. If the push bar 110 ascends and passes a certain point, the operating member 116 moves in a direction opposite to the moving direction of the push bar 110. Accordingly, a contact point is changed thereto. Ends of a first and a second terminal 118 and 120 are disposed and fixed inside the base case 110 for sending an electrical current. The operating member 116 has one end coupled to an end of the first terminal 118 and other end having a moving contact point member 124. The moving contact point member 124 of the first terminal 118 selectively contacts a fixed contact point member 122 installed at an end of the second terminal 124.

[33] Since the temperature control switch according to the present invention is generally installed in an apparatus requiring temperature control, i.e., air conditioners and refrigerators, it is preferable that the temperature control switch further includes a mounting bracket 134 having coupling members 136 at both end portions thereof and having a central portion connected to the cam member 128 for easily connecting the temperature control switch to the apparatus.

[34] The operation of the temperature control switch will now be described with reference to FIGS. 4 and 5, hereinafter.

[35] FIGS. 4 and 5 shows ON/OFF operations of the temperature control switch shown in FlG. 2. Referring to FIGS. 4 and 5, if the push bar 110 descends, the operating member 116 moves the contact point in the direction opposite to the movement of the push bar 110. Thus the moving contact point member 124 is separated from the fixed contact point member 122. On the contrary, if the push bar 110 ascends, the operating member 116 moves the contact portion in the direction opposite to the movement of the push bar 110. Thus, the moving contact point member 124 is in contact with the fixed contact point member 122.

[36] A numeral reference 126 depicts an on-screw that adjusts a contact point by pressing or releasing the moving contact point member 124 to and from the fixed contact point member 122.

[37] A numeral reference 128 denotes a cam member rotatably installed on the upper cover 102. A cam surface 130 thereof is located inside the storage space of the base case 100.

[38] A numeral reference 132 is a lever having one end fixed at a top wall of the upper cover 102, other end contacting the cam surface 130 and a central portion coupled with the off-screw 114.

[39] The cam surface 130 joined with the cam member 128 has a form of an oblique line. Accordingly, the height of the cam surface 130 continuously varies while the cam surface 130 is rotating. If a user turns the cam member 128, the cam surface 130 rotates and the height of the cam surface 130 contacting the lever 132 continuously varies. Correspondently, the height of the lever 132 also varies.

[40] While the cam surface 130 is rotating by the user, the lever 132 deliveries different loads to the spring 112 as much as the height variation of the lever 132 to strengthen or weaken the elastic force of the spring 112. That is, the cam surface 130 and the lever 132 allow the user to control the operating range of temperature by strengthening or weakening the elastic force of the spring 112.

[41] Hereinafter, an initial setting process of the temperature control switch according to the present invention will be described with reference to FIGS. 6 and 7.

[42] FIGS. 6 and 7 are perspective views of the temperature control switch in FlG. 2 showing the process of adjusting the on/off points. [43] Referring to FIGS. 6 and 7, the initial setting process of the temperature control switch according to the present invention proceeds as follows.

[44] At first, the charging line 108 containing the heat medium gas is immersed into a tub having a liquid alcohol. For example, if a user wants to set the electric current to be interrupted at a temperature around -30 , the temperature of the alcohol should be adjusted to -30 . Then, the heat medium gas contracts, and the bellows member 106 also contracts as shown in FlG. 6. After a certain period of time is surpassed, the contraction of the bellows member 106 is stopped. Then, the difference in force of the push bar 110 and the bellows member 106 becomes equivalent. In this condition, the off-screw 114 is tightened using a screw driver 300 so that the push bar 110 slowly descends toward the bellows member 106. While tightening the off-screw 114, the operating member 116 moves the contact point in a direction opposite to the movement of the push bar 110 as shown in FlG. 4. As a result, the fixed contact point member 122 becomes separated from the moving contact point member 124. If a clicking sound is made while moving the contact point, the tightening of the off-screw 114 is stopped. This is an off-point that the fixed contact point member 122 is separated from the moving contact 124.

[45] Hereinafter, the initial setting process for an on-point will be described. At first, the temperature of the alcohol is raised to around the desired temperature. For example, if a temperature of around -5 is desired, the bellows member 106 expands and pushes the push bar 110 upward, as shown in FlG. 7. Accordingly, the push bar 110 compresses the spring 112 and rises. In this stage, the operating member 116 moves the contact point to the direction opposite to the movement of the push bar 110 and it closely approaches to where the force difference is parallelized because the on-screw 126 is loosened at the initial setting. That is, the push bar 110 ascends little by little against the elastic force of the spring 112. Since the on-screw 126 does not push down the moving contact point member 124 yet, the push bar 110 ascends until the force difference is parallelized. After time elapses, the expansion of the bellows member 106 is stopped, and the on-screw 126 is tightened with a screw driver 300 to press the moving contact point member 124 toward the fixed contact point member 122. Then, the operating member 116 retaining a horizontal state moves suddenly in the opposite direction to the movement of the push bar 110. Therefore, the moving contact point member 124 becomes contacted to the fixed contact point member 122. In this state, the first and second terminals 118 and 120 electrically connect to the operating unit 116 through the two contacts 122 and 124, whereby electric current flows therebetween. Thus, the on-point is adjusted.

[46] After setting the initial on/off-points, the bellows member 106 expands and contracts according to the expansion and contraction of the heat medium gas. Therefore, the contact portion of the operating member 116 moves in a direction opposite to the movement of the push bar 110 while the push bar 110 is rising and falling. As a result, the moving contact point member 122 is controlled to be separated from or to be contacted to the fixed contact point member 124.

[47] The cam member 128 and the cam surface 130 are used not only for the on/off setting ranges. The cam member 128 and the cam surface 130 are also used for controlling the operating range for the target temperature by strengthening or weakening the elastic force of the spring 112 according to the height variation of the cam surface 130. For example, a refrigerator generally allows a user to change target temperature for high , medium and low range by turning a temperature control lever. The temperature control for the medium range is achieved through the on/off setting and the temperature control for the high or low ranges is achieved through changing the height of the cam surface 130.

[48] As described above, the temperature control switch according to the present invention has a simple structure by appropriately disposing and assembling components inside the single base case 100 while smoothly sensing the temperature and perform switching functions as well.

[49] While the present invention has been described with respect to certain preferred embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the scope of the invention as defined in the following claims.

Claims

[ 1 ] A temperature control switch comprising : a base case forming an interior storage space; a bellows member installed inside the storage space and connected to a charging line of a heat medium gas that expands and contracts according to a temperature change; a push bar disposed above the bellows member to elevate in the storage space according to an expansion and contraction of the bellows member; an off-screw having one end connected to the push bar with a spring being interposed between the one end and the push bar, and having another end connected to the base case so as to control a position of the push bar by turning the off-screw; a first terminal and a second terminal each having one end fixed in the storage space of the base case; an operating member shifting with the push bar, and having one end fixed to an one end of the first terminal and other end selectively contacting an one end of the second terminal; and an on-screw fixed to the base case for pressing the other end of the operating member to adjust a contact point with the one end of the second terminal.

[2] The temperature control switch of claim 1, further comprising: a cam member rotatably installed at the base case and having a cam surface located in the storage space; and a lever installed in the storage space to contact the cam surface to shift the off- screw according to a rotation of the cam member.

[3] The temperature control switch of claim 1, wherein a moving contact point member is disposed at the other end of the operating member that selectively contacts the second terminal, and a fixed contact point member is disposed at the one end of the second terminal so that electric current passes through the moving contact point member and the fixed contact point member when the moving contact point member contacts the fixed contact point member.

[4] The temperature control switch of claim 1, wherein the operating member is an elastic plate that is suddenly transformed in one direction at the moment transformation of the elastic plate exceeds a predetermined range in one direction.