Patent GB-837440-A (GB)
Title: Improvements in or relating to cock devices for mixing hot water and cold water
IPC: G05D23/13
Filed: 1956-09-05
Abstract: 837,440. Valves. HETTICH, H., and HETTICH, W. Sept. 5, 1956 [Sept. 5, 1955], No. 27246/56. Class 135. A hot and cold water mixing device comprises a casing having hot and cold water inlets 53, 54, a mixing valve 23 for adjusting the ratio of hot to cold water, a control valve 8 for controlling the quantity of water passed through the device, handles 13, 4 for operating the valves 23, 8, respectively, and arranged at one end of the casing 1 of the device, and a closure cap 2 at the opposite end of the device which may be removed to obtain access to the mixing valve 23. The mixing valve consists of a hollow piston 23 with annular grooves 51, 52 coacting with ports 64, 62, respectively, in a sleeve 10. The hot water entering the casing at 53 passes through a non-return valve 30 and a passage (not shown) leading to a port in the sleeve 10 in permanent communication with the annular groove 51, whilst the cold water also passes through a non- return valve and a passage leading to a port in permanent communication with the groove 52 so that the proportions of hot and cold water passed by the mixing valve 23 are determined by the relative openings of the ports 62, 64 which are in turn dependent upon the axial position of the valve. The hot and cold water after passing the valve 23 passes through passages 65, 63 to the seating of the control valve 8 which consists of a conical diaphragm. When the control valve 8 is withdrawn from its seat the hot and cold water may enter the interior of the sleeve 10 and pass through a filter 11 and the hollow interior of the mixing valve 23 to an outlet 39. The valve 23 is connected by a rod 20 passing through the control valve to a head 19 through which passes a pin 18 received in holes in a ring 17 having screwthreaded engagement with a sleeve 15 secured to the handle 13 whereby rotation of the latter, together with the sleeve 15, causes axial movement of the ring 17, pin 18, and head 19 and rod 20, the pin 18 being prevented from turning by its passage through slots in a sleeve 3 which is fixed in the casing. The handle 4 is secured by a screwed cap 5 to an internally threaded sleeve 6 which engages with a screwthreaded extension 7 of a backing member for the control valve whereby rotation of the handle 4 results in axial movement of the backing member which is prevented from rotating by engagement of its extension with the pin 18. To prevent the conical diaphragm from being pressed too strongly against its seat a screw 40 is carried by the cap 5 and has a head 42 to coact with an abutment in the extension 7. The conical diaphragm 8 is connected to the backing member by a sleeve 9 through which and through a sealing ring 21 the rod 20 passes. The handles 13, 4 are interconnected by a pin and slot arrangement 25 whereby closure of the control valve 8 causes the mixing valve to be adjusted to a position in which cold or cool water is discharged thereby preventing scalding when the control valve is re-opened. A stop pin 28 associated with a calibrated ling 26 can be adjusted to limit the temperature of water delivered by the device. In a modification, the rod 20 is connected to the mixing valve 23 through a spring and temperature-responsive bellows whereby the mixing valve is adjusted automatically to maintain a delivery temperature selected by the handle 13.