Patent GB-966147-A (GB)
Title: Fluid flow control valves
IPC: G05D23/02
Filed: 1962-08-02
Abstract: 966,147. Valves. SULZER FRERES S.A. Aug. 2, 1962 [July 4, 1962], No. 29787/62. Heading F2V. A fluid flow control valve applicable to room heating and cooling by hot and cold fluids respectively, includes a housing 1 having oppositely facing valve seats 18, 19 and a movable valve body 4 carrying oppositely facing closure elements 8, 10 co-operating with the seats and movable by external actuating means 40, the valve being provided with a temperaturesensitive changeover element 6 which is subjected to the temperature of the fluid flowing to the valve, and the arrangement is such that this element moves the valve body into different positions with the hot and cold fluids respectively so that for operation of the valve by the external actuating means one closure is effective with hot fluids and the other with cold, and such that an axial movement through the external actuating means which in the case of cold fluids reduces the flow cross-section of the valve will in the case of hot fluids increase the flow cross-section. The external actuating means 40 may be manual or it may be a second thermal element responsive to room temperature. The valve further comprises an axial adjusting element 3, movement of which by the external means 40 controls the flow crosssection of the valve, the changeover element 6 comprising two parts whose relative positions depend on the temperature of the medium, on part 33 being secured to the valve body 4 and the other part 9 being connected to the adjusting element 3 by a coupling such as that including a pin 16 and slot 22, 23, permitting relative movement limited in one direction by a first stop 23, the coupling including a first spring 13 between the adjusting element 3 and the other part 9 of the changeover element, biasing them toward the position in which the stop 23 is engaged, a pair of second stops 24, 25 limiting the relative axial movement of the valve body 4 and the adjusting element 3, a second spring 12 coupling the valve body 4 and the adjusting element 3 and biasing them toward a position in which one of the second stops 24, 25 is engaged, a pair of third stops 20, 21 limiting the axial movement of the adjusting element 3 relative to the housing 1, and a third spring 11 coupling the valve body to the housing and biasing the valve body to move relative to the adjusting member 3 in a direction resisted by the first and second springs 13, 12. The thermal element 6 may be of a known kind incorporating an encapsulated quantity of a mixture of petroleum jelly and a paraffin in which copper chips are incorporated, such that a relatively large change of volume occurs over a definite temperature range, e.g. between the points 36, 38 of the graph, Fig. 3, and outside this range the change of volume is relatively small. A by-pass return connected to the housing port 34 ensures that the thermal element 6 is kept at the temperature of the flowing fluid. An abutment ring 14 for the stops 20, 21 is adjustable in the housing 1. It will be apparent that closure 10 is the one effective in room cooling with cold fluids whilst closure 8 is that effective in heating with hot fluids.