FI67456C - TEMPERATUR- ELLER TRYCKSTYRDA KOPPLINGSENHETER - Google Patents

Description

r »1 ANNOUNCEMENT

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Patent · och ragisterstyralsMi '' AmMcm «h *!« * ** »*« psbMuml 30.11.84 (32) (33) (31) * n *** r «uolkeu * —Bagird priority 10.02.76

England-England (GB) 5116/76 (71) Ranco Incorporated, 601 West Fifth Avenue, Columbus, Ohio 43201, USA (72) Guglielmo Rossi, Stutensee-Friedrichstal, Federal Republic of Germany-Förbundsrepubliken Tyskland (DE),

Vincenzo Ferloni, Lurate Caccivio, I taiia-ltalien (lT) (74) Oy Borenius 6 C: o Ab (54) Temperature or pressure controlled switch units -Temperatur- eller tryckstyrda koppiingsenheter

The invention relates to a temperature- or pressure-sensitive coupling unit comprising a jacket with a fluid-filled deflection wall capsule mounted inside this jacket and an operating lever pivotally mounted in the jacket and adapted to control a switch attached to the jacket based on deformation of the capsule. located in the housing and acting on the operating lever, the spring applying torque to the lever in the opposite direction to the capsule, and means for adjusting the spring force and predetermining the clutch operating point based on the capsule deformation, the capsule and clutch being aligned with the operating axis pivot axis (X), and wherein the coupling comprises a pop-up switch having a fixed coupling contact attached to the insulating base and a pop-up coupling spring having an interoperable contact and popping acting on the same bottom.

According to an embodiment of the invention, a switch unit of the type described above is obtained, which is simple in structure and flexible in use so that it can be used in numerous practical applications.

According to the invention, a temperature or pressure-based clutch unit of the described type is obtained, characterized in that the electrically insulating base is located on the side of the jacket on the same side as the capsule, the freewheel clutch spring mounted on this electrically insulating base projecting in a direction generally parallel to the drive lever pivot axis (X) and that the clutch spring is mechanically actuated so that the operating lever can be depressed into the clutch spring to open and / or close the clutch contacts by popping.

The arrangement of the coupling unit so that the control shaft is located in the wall of the casing opposite the capsule and opposite the coupling itself allows simple assembly of the coupling unit, and in addition according to a preferred embodiment of the invention leaves sufficient space in the casing for auxiliary switches or switch components without having to change the coupling unit. .

The axis of the adjusting shaft is suitably perpendicular to the pivot axis of the operating lever.

According to a preferred embodiment of the invention, the prestressing spring is a helical spring having a longitudinal axis parallel to the operating lever, this spring being anchored at one end to the protrusion of the operating lever and at the other end to a sliding slide which can move in the eccentric direction of the spring. The eccentric can be used to fine-tune the spring bias and thus the operating point of the clutch, i.e. to set the temperature (or pressure) that the capsule detects and at which the clutch operates.

As used herein, the term "capsule" generally refers to any fluid-filled flexible-walled device, such as a bellows or membrane, that is deformed by a change in internal pressure, usually associated with a change in temperature at a distant sensing point to which the device is connected by a capillary tube. The switch unit according to the invention does not necessarily have to be used to know the temperature in this way, but the switch unit could e.g. be used as a pressure-operated switch, in which case the pressure under which the switch operates would be the fluid pressure in the capsule.

In order to be able to adjust the setting limits of the eccentric, the biasing spring is suitably secured by means of an adjusting screw to a slide slide operated by the eccentric, by means of which the spring tension can be adjusted independently of the eccentric adjustment.

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The filling lever may have a spring which is pivotally supported on opposite walls of the jacket by means of lugs of this spring between the switch and the point of contact between the operating lever and the capsule.

According to a preferred embodiment of the invention, the clutch has an electrically insulated base attached to the housing and supporting a fixed clutch contact and a pop-up coupling spring supporting a clutch contact movable relative to the fixed contact so that the operating lever can be depressed to open or close the spring. Suitable spring springs for this purpose are the # springs described in British Patent Applications 49,726 / 74 and 12,875 / 75, which are incorporated herein by reference.

The opening of the switch contacts to the open position of the switch can be suitably adjusted by means of an adjusting screw, which can be accessed from outside the casing. This so-called the differential adjusting screw operates to adjust the temperature range (or pressure range in the case of a pressure-operated switch) between the open and close positions of the switch contacts. According to a preferred embodiment, the spring-loaded coupling spring is fixedly mounted on the insulating base so as to protrude protrudingly from its fixed mounting point in a direction generally parallel to the pivot axis of the operating lever.

The switching unit according to the invention can be adapted to perform several switching functions. Thus, according to a preferred embodiment, in which the eccentric is an eccentric disc located in the jacket and mounted on a rotatable adjusting shaft projecting from the jacket, an auxiliary eccentric acting on the first auxiliary switch in the jacket via a monitoring lever mechanism can be mounted on the same shaft as this eccentric. with. This auxiliary switch is normally arranged on the same insulating base as the first, i.e. the main switch. The lever mechanism cooperating with the auxiliary eccentric may, for example, have an angle lever, one arm of which presses into the auxiliary eccentric, and the other arm has a hinge connection to a piston which can move longitudinally in the housing so that it presses into the auxiliary switch drive part. Both the angle lever and the piston are suitably made of plastic, whereby the hinge connection between the angle lever and the piston is an integral flexible hinge of the same plastic.

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For some practical applications, it may be necessary to use an externally adjustable eccentric system to adjust the operating point of the switch, in which case it will be possible without this eccentric. A temperature or pressure operated coupling unit according to an alternative embodiment of the invention has a jacket with a fluid-filled flexible wall capsule attached to the jacket wall, an operating lever pivotally mounted on the jacket and adapted to control a switch in the jacket based on deformation of the capsule, on the same side of the operating lever, a biasing helical spring acting on the operating lever and extending generally parallel to this lever on the other side of the capsule and clutch, and an adjustable anchoring point for the end of this biasing spring furthest from the operating lever. , wherein the operating lever is pivotally supported from opposite walls of the casing so as to be able to perform a wobble movement about a transverse pivot axis perpendicular to the against the longitudinal axis of the tension spring.

The second lever may be pivotally mounted on the casing so as to press against the clutch operating lever to allow this wobble movement in only the other direction, this second lever being pre-tensioned by a tension-adjustable spring. A biasing spring acting on this second lever may be attached at a distance remote from this second lever to a position adjustable by non-Kesko to predetermine the force that this second lever applies to the clutch operating lever.

The invention will be explained in more detail below on the basis of the exemplary embodiments described in the accompanying schematic drawings.

Figure 1 shows a cross-section of a temperature-controlled switch unit according to an embodiment of the invention.

Fig. 2 is a partial sectional view taken along line II-II of Fig. 1 of a switch used in the switch unit shown in Fig. 1.

Fig. 3 shows a cross-section of the switch taken at line III-III in Fig. 2.

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Fig. 4 shows a section of a modified embodiment of the switch unit shown in Fig. 1.

Fig. 5 shows a view similar to Fig. 3 of a modified switch of the switch unit shown in Fig. 4.

Fig. 6 is a sectional view taken along line VI-VI in Fig. 5 of this modified switch.

Fig. 7 is a cross-sectional view and a view similar to Fig. 2 of a switch used in a switch unit according to another embodiment of the invention.

Fig. 8 shows a cross-section similar to Fig. 3 taken at line VIII-VIII in Fig. 7.

Fig. 9 is a view similar to Fig. 1 of a switch unit according to yet another embodiment of the invention.

Fig. 10 is a sectional view of a modification of the switch unit shown in Fig. 7.

The basic switch unit shown in Fig. 1 has a sheath 1 formed of a pressed metal plate frame 2 having a U-shaped cross section and partially closed at its open side by a pressed metal support plate 3. The flexible-walled fluid-filled capsule 4 is attached to this support plate 3, and the switch 5 is fixed to the frame 2 so as to engage the support plate 3 and close the remaining part of the open side of the sheath 1. Switch 5 will be explained in detail below with reference to Figures 2 and 3.

The switch unit shown in Figures 1 ... 3 is a temperature-dependent unit. The capsule 4 contains steam-filled bellows devices formed of two flexible metal walls welded together along interconnected edges so as to form a sealed capsule which communicates via a capillary tube 6 with a temperature sensing dome 6a located at a point where the temperature is to be felt. This dome 6a, the capillary tube 6 and the capsule 4 form a hermetically sealed fluid-filled system in which the prevailing pressure directly depends on the temperature of the dome. The walls of the capsule 4 are deformed by changes in internal pressure and thus 6 67456 according to the temperature known by the dome 6a. This deformation is transmitted to the clutch operating lever 7 »which has a rigid metal plate which is pivotally supported by a sheath 1 so as to perform a wobble movement about the pivot axis X.

For the sake of clarity, the plate forming the clutch operating lever 7 is not shown in Fig. 2. This plate has laterally projecting lugs 7a which press into the openings in the side walls of the sheath 1 to deflect the pivot axis X of the lever 7.

On the other side of the pivot shaft X there is a tip 8 formed on the operating lever 7, which presses into a protrusion 9 welded to the central part of the capsule 4 to reinforce this so that the capsule walls are deformed between the reinforcing protrusion 9 and the capsule outer circumference. On the other side of the pivot shaft X, a protrusion 10 is formed on the drive lever 7, which is located on the same side of the lever as the tip 8, which presses against the drive tongue 11 mounted on the support of the pop-up clutch spring 12 (Figures 2 and 3).

On the opposite side of the drive lever plate to the protrusion 10, and on the same side of the pivot shaft X, the drive lever 7 has an upwardly extending lug 13 forming an attachment point for the other end of the helical bias spring 14, the opposite end of which is secured to a nut screwed to the adjusting screw 15. 16 is located in the opening of the protruding part 17 of the cam slider 18 so that the base 16 of the screw 15 can be accessed for adjustment through an opening 19 in the end wall of the jacket 1. By adjusting the position of the screw 15, the tightening of the spring 14 can be adjusted and thus the biasing torque applied to the clutch operating lever 7 counterclockwise as seen in Fig. 1, which in turn adjusts the force with which the operating lever 7 presses into the capsule 4.

The cam slide 18 is displaceable in a straight line on the bottom wall of the frame 2, and has an end flange 20 which remains pressed against the disc-like outer edge of the eccentric 21 by the biasing spring 14. This eccentric 21 is fixed to a control shaft 22 which can rotate in a sleeve 23 fixed to the bottom wall of the frame 2 so that this shaft 22 protrudes from the casing 1. The axis of rotation of the shaft 22 is perpendicular to the transverse axis X 67456 of the clutch lever 7 and also generally perpendicular against the longitudinal axis 14 of the helical bias spring.

The end away from the switch 5 of the operating lever 7 is located in a notch 24 in the end wall of the casing 1 for a turn around the axis X of the lever 7. the extreme limit of the movement. At this end, an upwardly directed projection 25 is made on the lever 7, into which the cam slider flange 20 is pressed in the second position of the adjusting shaft 22 to guide the switch 5 directly to the open position of this shaft 22 ".

The switch 5, which is a part of the switch unit, is an independent unit which is assembled separately and fitted in the housing 1 of the switch unit. The switch shown in Figures 1 and 2 has an insulating base 26 molded from plastic.

Two conductors 27, 28 are attached to this base 26, and these conductors terminate in respective quick connectors 29, 30 projecting from the base 26. The fixed switch chain 31 shown in Fig. 3 is supported by the conductor 28, and that co-operation! popping with a movable clutch contact 32 resting on the operating clutch spring 12.

The pop-up clutch spring 12 has an integral outwardly projecting tongue 33 by which this spring 12 is cantilevered to the conductor 27 and thus to the base 26 and to the pivot axis X of the drive lever 7.

The clutch spring 12 has two arms 34, 35 which are pulled together by shrinking an integral bridge portion 36 which connects the ends of these arms furthest from the tongue 33 and thus biases the spring so that it deforms concavely near the base of both arms 34, 35 associated with the tongues 11, 33. As a result of this biasing of the spring 12, the arms 34, 35 will have a first stable position in which the disc spring is bulged in the other direction and both arms 34, 35 are located on the other side of the central tongue 11, and a second stable position in which the disc spring is bulged in the opposite direction. located on the opposite side of the central language 11. The intermediate position in which the arms 34, 35 are flush with the central tongue 11 is inherently unstable, so that the disc spring will pop up to change shape between these two stable positions.

the movable contact 32 is fixed to the center of the bridge portion 36 and is arranged relative to the fixed contact 31 such that as the spring 12 changes shape 67456, the contact 32 performs a popping movement relative to the fixed contact 31 in either the switch opening or closing direction.

According to an alternative construction of the coupling spring 12, the bridge part 36 is the contact 32 itself, which may be a rectangular plate welded to both arms 34, 35 so as to pull these arms together and bias the spring.

In the embodiment of the invention described herein, the clutch spring 12 itself is conductive and current between the two conductors 27, 28 when the switch is closed. Therefore, the clutch operating lever 7 has an insulating part 37 in which a clutch driving protrusion 10 is formed so that the clutch operating lever and the associated mechanical parts of the unit are electrically isolated from the live parts of the clutch 5.

In this embodiment, the clutch 5 is of the normally open type, and the clutch operating lever 7 acts through the protrusion 10 and the clutch operating tongue 11 and moves the latter towards the clutch base 26 (Fig. 3) until an unstable position is reached, whereby the clutch spring 12 pops towards its second stable position and may contact 32 with fixed contact 31. The position of this contact 31 is such that the clutch spring 12 does not have to reach its second stable position, and as a result the central operating tongue 11 of the clutch spring remains depressed in the operating lever 7. When the force exerted by the operating lever 7 on the tongue 11 thus ceases, the tongue 11 moves away from the base 26 when the operating lever 7 oscillates counterclockwise (as shown in Fig. 1) until the unstable position of the spring 12 is again reached, a spring movement of this spring which moves the contact 32 from its contact with the fixed contact 31 towards another stable position, moving towards this second stable position of the contact 32 is stopped by a response formed by a screw 38 located at the bottom of the switch 26. By adjusting the position of this screw 38, the gap between the switch contacts 31, 32 can be adjusted with the switch open and the force of the movable contact 32 pressed in turn adjusts it to the closing temperature j of the switch a temperature difference between the opening temperature, which is detected by the dome -6a connected to the capillary tube 6. For this reason, screw 38 will be referred to as the "temperature difference" adjustment screw.

9 67456 By adjusting the angular position of the eccentric adjustment shaft 22, the tension of the biasing spring 14 is adjusted because the cam slide 18 moves without pushing the eccentric 21, which in turn adjusts the biasing force applied by the drive lever 7 to the capsule 4. For each angular setting of the shaft 22 there will be a different operating temperature of the switch so that the internal pressure of the capsule 4 known to the dome 6a, and thus a second temperature will be necessary to make the switch operate at each adjusted position of the eccentric. When using a certain arrangement of the shaft 22, by adjusting the adjusting screw 15, the switch can be made to operate under the influence of the desired temperature (or pressure) known to the capsule 4. The temperature (or pressure) at which the switch operates can then be selected by manually rotating the shaft 22.

As explained and shown on the basis of Figures 1 to 3, the switch unit is particularly suitable, e.g. for monitoring the refrigerator, in which it is desired to close the switch 5 and thus start the refrigerator compressor motor when the temperature known by the capsule 4 rises to a predetermined level. then open the switch 5 and stop the motor when the temperature felt by the capsule 4 has dropped to the second lower level. The switch unit will operate to maintain a controlled temperature between these two levels. For this use, there will be a manual element on the control shaft, such as a knob, that can be rotated • between the “warm” and “cold” positions to set different operating temperatures for the switch. In addition, this adjusting shaft 22 usually has an "open" position corresponding to the depression of the flange 20 of the cam slider 18 into the protrusion 25 of the clutch operating lever, whereby this depression causes the operating lever 7 to sway against the counter-clock (as seen in Figure 1).

In the structure of the coupling unit illustrated in Figures 1 to 3, the capsule 4 is attached to the support plate 3 by riveting or using a cylindrical collar 39 welded to one flexible plate of the capsule 4 as shown in Figure 1, the capsule 4 remaining in place by the capillary tube 6. the bulging portion 40 presses against the deformed collar 39.

The eccentric 21 is welded to the inner end of the shaft 22. The shaft 22 itself is fitted to the sheath 1 by means of a sleeve 23 with a circumferential outer lip 41 which, when the shaft 22 and the eccentric 21 have been assembled, is deformed inwards so as to press against the shoulder 42 in the shaft 22.

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The switch unit shown in Figs. 1 to 3 is a basic unit that can be converted to provide a whole group of different switch units to perform various switching tasks, thereby adding components, but only slightly modifying the components of this basic switching unit.

Figures 4 to 6 illustrate a modification of the basic switching unit with an additional switch included in the switch 5 »This additional switch is electrically connected in series with the switch contacts 31, 32 of the main switch 5 and operates in an auxiliary or" closed / open "mode. as a switch.

In the embodiment shown in Figures 4 to 6, the auxiliary switch is a resilient contact spring 43 »on which a coupling contact 44 is arranged, which normally presses on the fixed contact 45. At 46 the contact spring 43 is pressed by a piston 47 located inside the jacket and guided longitudinally by a pin 48 projecting from frame 2 and made as an integral part of this frame. The piston 47 has a hinge connection to a corner lever 49 which is pivotally mounted inside the jacket 1 on a transverse shaft 50. Both the angle lever 49 and the piston 47 are made of thermoplastic, and both parts are interconnected by a thin hinge joint 51 between the piston 47 and the lever 49 the arm not connected to the piston 47 presses on the auxiliary eccentric 52, which is located on the same shaft 22 as the eccentric 21.

The arrangement is such that when the shaft 22 is rotated to the "open" position, the auxiliary eccentric 52 pulls the angle lever 49 clockwise as shown in Fig. 4, and presses the piston 47 down sufficiently to move the auxiliary clutch spring 43 and open the auxiliary clutch contacts 44, 45.

Since a separate series switch is used in the embodiment of Figures 4 to 6 to perform the "open" task, the protrusion 25 of the switch operating lever 7 is notched at 53 so that neither eccentric 21, 52 is pressed against it.

In both embodiments described with reference to Figures 1 to 3 and Figures 4 to 6, the switch may include an auxiliary signal switch mounted on the same base 26 as the main switch 5. Modifying the switch shown in Figures 2 and 3 to include an auxiliary signal switch. 67456, is shown schematically in Figures 7 and 8. The auxiliary signal switch has a movable contact 54 arranged on a protruding contact spring 55 having a side arm 56 located below the central drive tongue 11 of the main switch clutch spring 12 (Figure 7). The auxiliary switch has a fixed contact 57 connected to the auxiliary contact terminal 57 *. The fixed contact 57 is placed either above or below the movable contact 54, as shown in Figure 7, depending on whether this auxiliary contact should be normally open or normally closed. In the illustrated embodiment, the auxiliary contact is normally open.

When the central tongue 11 of the clutch spring 12 is depressed by the operating lever 7, the tongue 11 is pressed against the arm 56 and causes it to pivot about a pivot axis formed by an adjusting screw 58 screwed into the base 26, thereby causing the movable contact 54 to move into contact with the fixed contact 57. The auxiliary signal switch contacts 54, 57 can be used to monitor the operation of the main contact in the event that the temperature rises abnormally outside the normal operating range of the main switch, with the temperature at which the auxiliary switch operates determined by the setting of the adjusting screw 58.

A typical example of the use of an auxiliary signal switch is a refrigerator in which the compressor has stopped working or is malfunctioning, and the thermostat controller is still operating properly with contacts 51 and 32 closed. Since the compressor is not running, the temperature felt by the tactile hood will rise and the tongue 11 will be depressed sufficiently to come into contact with the arm 56 to operate the auxiliary switch.

If the auxiliary switch contacts 54 and 57 are normally open and connected to a circuit that includes a monitoring lamp, the lamp will illuminate when the auxiliary signal switch operates. Alternatively, if the auxiliary switch contacts 54 and 57 are normally closed, the associated circuit will be open when the auxiliary signal switch has operated.

The switch units described so far are suitable for use in monitoring refrigerators, in which the intermittent operation of the compressor motor is automatically controlled to keep the refrigerator evaporator within predetermined temperature limits. Some simple applications for the control switch provide cyclic temperature variations between fixed, predetermined limits, and in this case 12 67456 the temperature selecting eccentric 21 and associated control shaft 22 can be omitted, pressing the bias 15 of the bias spring 14 directly into the switch unit frame 2.

In "two-door" type refrigerators with a freezing compartment and a fresh food compartment and two different evaporators, an automatic defrosting cycle of the evaporator located in the fresh food compartment is usually arranged for each cycle of compressor operation while the refrigeration compartment compressor continues to operate. To this end, the corresponding control switch must have a "switch-on" temperature (ie the closing temperature of the switch) above the freezing temperature and a "switch-on" temperature (ie the opening temperature of the switch) low enough to give rise to a suitable temperature in the freezer compartment to store deep-frozen food.The "switch on" temperature must be selectable within certain limits, while the "switch on" temperature must always remain constant and above the freezing temperature to allow each defrost cycle to run.

The switch unit according to the invention can be adapted to meet these requirements. Fig. 9 schematically shows a modification of the switch unit shown in Fig. 1 performed for this purpose.

In addition to the components in the clutch unit shown in Figure 1, the unit of Figure 9 has an auxiliary prestressing spring having a flat spring 59 anchored at one end to the clutch housing frame 2 and acting on the clutch operating lever at one end to align (60) , in the same direction as the bias spring 14 acting on the counter-clock of this operating lever (as seen in Fig. 9). In this embodiment, the adjusting screw 15 of this bias spring 14 is anchored in the opening 19 in the casing 1 and thus the spring 14 can be adjusted only by the eccentric adjustment shaft 22. Thus, when the pressure acting on the capsule 4 increases due to the rise in temperature felt by the capsule, the point at which the operating lever 7 always controls the switch to be constant and thus represents the desired "switch to operate" operating mode. In order to vary the "switch-on" temperature, the L-shaped lever 61 controlling the "switch-on" operation is pivotally mounted on the switch housing frame 2 at 62, where the coil spring 63 biases this lever 61 against the counter-clock, as shown in Fig. 9.

One end of this spring 63 is fixed to the lever 61 and the other end of the spring 13 67456 is fixed to a screw 64, the base of which is arranged on the protruding part 17 of the cam slider 18. Lever 61 has a protruding arm 65, which is a joint action! with a fixed stop 66 in the clutch housing. The lever 61 further has a rounded portion 67 which cooperates with the clutch operating lever 7 when rotating this operating lever counterclockwise (as shown in Fig. 9) so that the stop 66 during rotation and before the switch 5 opens, the operating lever 7 is pressed into the part 67 of the lever 61, after which the movement of this lever is resisted by the tension of the spring 63. The point at which the clutch opens is thus determined at least in part by the biasing of the spring 63, and thus by the angular positioning of the adjusting shaft 22.

The embodiment shown in Figure 9 is similar; as shown in Figure 1 in that steps have been taken to open the clutch contacts, i.e. to open the clutch in a position on the control shaft 22. In the embodiment shown in Fig. 9, a second eccentric 68 is arranged on the control shaft 22, which can be pressed into the protrusion 25 on the clutch operating lever 7 to pull the operating lever counterclockwise (as seen in Fig. 9) and open the clutch when the control shaft 22 is in the "open" position.

Fig. 10 shows an alternative switch unit similar to that shown in Fig. 9, but with a separate "open switch" controlled by an auxiliary eccentric 52 on the control shaft 22, as previously described with reference to Figs. 4, 5 and 6. In other respects, Fig. 10 the switch unit is similar to that shown in Fig. 9.

If it is desired to vary the "engage" switch (switch unit), the bias spring 14 in the embodiments shown in Figures 9 and 10 may be anchored to the cam slide 18 in a manner similar to the coil spring 63, as shown in Figures 1 and 4. Alternatively, the spring 63 may be anchored to the jacket frame 2 and the spring 14 may be anchored to the cam slide 18, in which case the clutch unit will operate substantially in the same manner as the unit shown in Figure 1, but with a larger temperature (or pressure) difference between its control periods.

In order to avoid adverse interferences caused by the environment, it may be necessary for U 67456 to provide a heater for the capsule 4 in order to keep this capsule at a constant temperature. Fig. 69, Fig. 5, shows in broken lines an embodiment of such bellows heaters, consisting of a heating resistance permanently connected between the switch terminals 29, 30 in parallel with the switch contacts 31, 32 so that current flows through the heating resistance when the switch contacts are open, the heater is effectively short-circuited when the switch contacts are closed. The heating resistor 69 is located in the switch 5 for convenience, but is located close to the capsule 4 to achieve optimal heating power with a low power heater.

Claims (6)

1. For temperature or pressure sensitive coupling unit, with a housing (1) containing a fluid-filled capsule (4) with a flexible wall, mounted within the housing, and an actuating lever (7) pivotally mounted within the housing and arranged on the base of the deformation of the capsule (4) controls a connector (5) located within the housing (4), a tension spring (14) located within the housing and actuating the actuating lever, this tension spring (14) exerting a torque on the lever in the opposite direction. direction than that which the capsule (4) exerts, and means for controlling the tension of the spring and in advance determining the point of operation of the connector on the base of the deformation of the capsule (4), with the capsule (4) and the connector (5) relative to the shaft (X). ) are arranged on opposite sides, and wherein the connector (5) consists of a snap-acting clutch member attached to an insulating base (26) with a fixed clutch contact (31) and a snap-in operating member attached to the same bottom (26) A coupling spring (12) provided with a cooperating contact (32), characterized in that the electrically insulating bottom (26) is located on the side of the housing (1) and on the same side as the capsein (4), the bottom (26) attached bearing clutch spring (12) extends in a direction generally parallel to the reversing shaft (X) of the actuating lever (7), and that the clutch spring is mechanically actuated so that the actuating lever (7) can abut the clutch spring (12). snap open and / or close the coupling contacts (31, 32). A coupling unit according to claim 1, wherein the means for regulating the tension of the spring (14) comprises an eccentric (21) located inside the housing (1) and which is fixed to the control shaft (22) rotatably mounted on the housing (1). wall, characterized in that the insulating bottom (26) of the coupling joins the housing next to the capsein (4) and opposite side to that of the housing walls, where the control axis (22) of the eccentric (21) is located. Coupling unit according to claim 1 or 2, characterized in that the opening of the coupling contacts (31, 32) can be controlled while the contacts are open by means of a differential control screw (38) known per se which can be reached beyond the housing (1). ). 4. A coupling unit according to claim 2, characterized in that an auxiliary eccentric (52) is mounted on the same control shaft (22) as the eccentric disk (21), this auxiliary eccentric transmitting the eccentric follower lock