GB227158A - Improvements in and relating to thermo-regulators - Google Patents

Abstract

227,158. Bishop, H. S. Oct. 3, 1923. Thermostats.-In a device for controlling the supply of a heating or cooling fluid, the temperature-sensitive member is of the kind comprising a number of elements formed of materials having different coefficients of expansion, and comprising a rod 1, Fig. 1. of silica &c. arranged within an open-ended tube 2 of similar material, around which is another tube 4 having a relatively larger coefficient of expansion, the whole being enclosed in a tubular element 8 also having a large coefficient of expansion. The upper end of the rod 1 bears on a lever 10, the outer end of which is in contact with the stem 13 of the valve which controls the supply of fluid. The valve comprises a chamber 15 having inlet and outlet passages 16, 17 and containing a fixed diaphragm 20 and a movable member 18 connected to the stem 13. The area of the chamber is considerably greater than that of a conduit permitting the maximum rate of flow of the fluid, and the total areas of the apertures in the diaphragm and in the movable element are each not substantially, less than the area of the passage leading from the valve chamber. The apertures 21 in the diaphragm are formed in concentric grooves 22, the elevations 23 between which form the seating surfaces, and the apertures 24 in the member 18 are also formed in concentric grooves 25, the elevations 26 between which are in register with the grooves 22. The member 18 is mounted on a threaded spindle 29 which can be turned by a wheel 36 to adjust the valve independently of the temperature-sensitive device, the member 18 being prevented from rotating by a pin 30 carried by the diaphragm and passing through an aperture in the member 18. In a modification, Fig. 3, the tube 8 is connected by a collar 43 to a tube 44 having a large coefficient of expansion and freely mounted in an extension 45 from the chamber 14. Within the member 44 is a tube 46 of silica &c. bearing at one end against the collar 43 and at the other end against the chamber 45, a spring 48 being interposed between a shoulder 49 on the tube 44 and the cap 50 of the chamber 45.