Patent GB-1035861-A (GB)
Title: A fluid control valve
IPC: G05D23/08
Filed: 1963-01-25
Abstract: 1,035,861. Valves. ROBERTSHAW CONTROLS CO. Jan. 25, 1963 [Jan. 26, 1926], No. 3306/63. Heading F2V. A valve control structure comprises a housing 45, 46, Fig. 3, a valve member 55 carried by the housing and controlling fluid flow through a passage 49, 53 in the housing, and clutch means 122 operatively connecting a control device 107 with the valve member over one or predetermined sections forming part only of the range of movement. In the preferred embodiment, the valve member 55 provides manual regulation of the gas flow to a burner 42 while the clutch means 122 disconnects the drive to permit continued rotation of the control device to set a thermally-actuated valve 59 downstream of the valve 55. When the latter is closed, an abutment 114 on the control device is in driving engagement with tangs 127, 128 on the clutch means which has further tangs 124 in engagement with slots 125 of an extension 115 on the valve member. As the control device, clutch means and the valve member are rotated towards the open position, a cam surface 120 on a stationary plate 118 tilts the clutch means about a pair of projections 126 to free it from the abutment 114. The valve member 55 is thus diconnected from the control device and further rotation of the latter causes a cam 106 to displace a spring-loaded pin 95 for setting the thermally-actuated valve 59. If the burner is required to operate with a small flame under control of the valve 59, the control device is rotated until the abutment 114 engages a staggered tang 129 on the clutch means and the valve member 55 is then turned until partially closed, the control device being subsequently returned to the required temperature setting. The valve 59 is universally pivoted on a lever 64 which has a fulcrum pin 63 supported by the valve housing and is connected by a torsion spring 97 with a lever 74 pivoted at 73 in the lever 64. The lever 74 is arranged to be engaged by the pin 104 of a temperature-sensitive element 102 and has its position in relation to the pin 104 adjusted by a second lever assembly having an extension 94 engaged by the camcontrolled pin 95. To permit overshoot of the temperature-sensitive element, the second lever assembly includes a lever 76 which has a projection 75 to engage the lever 74 and is urged by springs 82 into engagement with a screw 88 on a manually-adjustable lever 84, the levers 76 and 84 being pivotally connected at 78 to a lever 60 which carries the extension 94 and is pivoted on the pin 63. Fig. 21 shows an alternative construction in which a clutch means 156 has a tang 159 for engagement by an abutment 164 on a control device 162 and a pair of tangs 155 to engage grooves 154 in the valve member 149. A camming surface, to disengage the tang 159 after the valve has been opened, is formed inside the housing and a shaped disc 172 fast with a spindle 168 may be turned to engage a pin 157 when the burner is to be operated with a low flame. Fig. 31 illustrates a further construction in which a rotary disc 187 has an arcuate groove 190 to place inlet and outlet ports 178 and 184 in a stationary valve body 183 into or out of communication with each other while a disc 194 regulates flame height by partial obturation of the outlet port. When the disc 187 has been turned to its " open " position, a tang 210 on a clutch member 209 engages a stop inside the valve housing so that further rotation of a driving disc 197 forces a tang 208 clear of a slot 207 to disconnect the drive to the disc 187. Continued rotation of the driving disc causes the disc 194 to reduce the gas flow, the tang 208 momentarily engaging a slot 206 to provide an audible indication of this stage of the operation. The Specification also describes modified port arrangements in the valve 55 in Fig. 3 to provide smaller gas flows during low flame operation of the burner.