DE1049131B - Thermostat with setpoint adjuster - Google Patents

Description

GERMAN

The invention relates to setpoint adjusters for those working with liquid expansion agents Thermostats that have a displacement body that can be adjusted by means of a threaded spindle and that counteracts Overpressure is secured by a pretensioned spring, which allows an additional expansion of the fluid system in the event of an overload.

Control elements that work with liquid expansion - thermostats for temperature regulators - have been used since Built for decades. It is also known to have a safety device in the temperature sensor built in, which responds when the setpoint is manually adjusted from a higher to a lower temperature the valve will eventually close. If the temperature sensor is already at closed valve should continue to be forcibly adjusted to a lower temperature, whereby If the liquid enclosed in the sensor is compressed, then the liquid already occurs first mentioned safety device in thermostats in action. Is still on the Solhvert adjustment device Turned further by hand, then you can, as then be explained in more detail below the individual components of the thermostat will eventually be destroyed.

In order to eliminate this disadvantage, an additional fuse is provided according to the invention, which, for example designed as a ratchet, when a permissible torque is exceeded when setting gives way. This device avoids damage to the entire regulator assembly.

The invention is shown and described in an exemplary embodiment in a drawing.

A designed as a hollow body temperature sensor 16, which with the help of a union nut 12 at the measuring point in a controlled system, z. B. a steam-heated boiler is installed, is with a liquid with the largest possible expansion coefficient, z. B. petroleum filled. When the temperature rises at the measuring location, the kerosene expands. The increase in volume is transmitted via a capillary tube 13 to a metal hose piston 22 in a working body 23 which, for. B. is connected to a closing valve 18 . By increasing the volume of the petroleum enclosed in the sensor 16 , the metal hose piston 22 is compressed and, with the help of a cone rod 21, pushes a cone 19 in the direction of the valve seat 20 of the A ⁷ Cntils 18. The flow rate of the heating medium through the valve 18 is thus, as is known, in proportion to the Control deviation changed.

If, with the valve closed, due to a leak between valve seat 20 and cone 19 or due to heat storage in the boiler, the temperature

Applicant:

Karlsruhe industrial works
Corporation,
Karlsruhe, Gartenstr. 71

Winfried Wiethüchter, Karlsruhe, has been named as the inventor

continues to rise, the liquid enclosed in the sensor 16 expands further. Since the cone 19 rests immovably against the valve seat 20 , this additional increase in the volume of the petroleum cannot compress the metal hose piston 22 any further. In order to protect the sensor 16 against bursting, a further metal hose piston 14 is provided in a known manner, which in normal operation is supported by several intermediate links, namely a spindle 15 with hose base 17 and threaded head 8, an adjusting nut 5 with a collar 10, a spring 6 in a sleeve 9 and a stop 11, is held in an unchanged position. Only when there is a certain excess pressure in the sensor 16 is the hose piston 14 compressed against the tension of the spring 6 and thus absorbs the additional increase in volume.

The metal clutch flask 14 also serves to set the target temperature. The deeper the hose piston 14 dips into the sensor 16 , the more expansion fluid, e.g. B. petroleum is displaced via the capillary tube 13 into the working body 23 , that is, the sooner the cone 19 of the actuator 18 will have shut off the flow of heating medium. If, for example, an actual temperature of 90 ° C. prevails in the controlled system and this actual temperature is to be adjusted from 90 ° C. to a setpoint temperature of 40 ° C., the tube piston 14 is immersed deeper into the sensor 16 with the aid of the adjusting nut 5. The adjusting nut 5 is turned using an attachable key. Since it is pressed against the stop 11 by the spring 6 and the collar 10 , it remains unchanged in its position. The threaded head 8 moves downward in the thread 7 together with the spindle 15. The thereby displaced petroleum can flow over into the working body 23 until the

809 730/227

Claims (1)

Cone 19 comes to a stop in valve seat 20. If you turn the square head 1 further, the internal pressure in the sensor and in the working body first increases; Finally, the spindle 15 can no longer be adjusted downwards, so that the adjusting nut 5 on the threaded head 8 will screw upwards as it continues to be turned. When using force, for example when adjusting from 90 to 40 °, experience has shown that the spring 6 is so strongly tensioned that an impermissibly high pressure is created inside the sensor 16; this initially changes the shape of the metal hose pistons 22 and 14 very greatly. This changes the setpoint setting. The metal hose, which has been changed in shape, has only a short lifespan, so that the thermostat will soon become unusable. In order to prevent overstressing when adjusting the setpoint from a higher to a lower temperature, according to the invention a ratchet 2 is connected between the wrench 1 and the adjusting nut 5 , which disengages when force is used. The extent to which the ratchet disengages is determined by the tension of a spring 4 , which can be adjusted by a screw 3 as required. When a certain pressure, for example 30 atmospheres, is reached in the sensor 16 , it should no longer be possible to adjust the temperature from a higher to a lower value. The ratchet is set so that in Thermostat at a pressure below 30 atm there is a rigid connection between the square 1 and the adjusting nut 5 . When the pressure of 30 atmospheres is exceeded, the resistance to adjusting the metal hose piston 14 is so great that the ratchet 2 disengages. The thermostat is thus protected against violent overload. A further adjustment to a lower temperature is only possible when reduced by cooling the medium to be controlled ίο at the measuring the volume of liquid in the probe 16 and the internal pressure has reduced accordingly. Claim: Setpoint adjuster for thermostats that work with liquid expansion agents that have a have adjustable displacement body by means of a threaded spindle, the against overpressure is secured by a pretensioned spring, which allows an additional expansion of the fluid system in the event of an overload, characterized in that, that an additional fuse is provided, which, for example, designed as a ratchet, yields when a permissible torque is exceeded when setting. Considered publications:
Austrian Patent No. 65 138;
U.S. Patent No. 2,353,889. 1 sheet of drawings