GB307445A - Improvements in power operated valve opening and closing apparatus - Google Patents

Abstract

307,445. Jones, C. E. Dec. 7, 1927. Electrically-actuated valves. - In electric-motor operated valves for high pressures fitted with by-pass valves which admit a restricted flow prior to the opening of the main valve the operating-means of the bypass valve is provided with an interlocking or interconnecting switch in the motor circuit so that the by-pass valve must be opened before the motor circuit can be closed and the main valve opened; after opening the main valve, the by-pass can be closed whilst leaving the main valve free, within limits, for movement by the motor in the opening and closing direction. In the arrangement shown in Figs. 1, 3 and 8 the manipulation of the hand-wheel g<4> to open the bypass valve G, closes also a switch q disposed in a box F and arranged in series with the motor circuit switch K so that the electric motor can be started up. The general operation of the valve is described in Specification 307,444. In the opening of the main valve the shoe D on the crosshead v' frees a lever E which has previously held open a short-circuiting switch p<1>, this switch being now free to be closed by its spring and allowing the motor to be operated although the bye-pass valve G may be closed and the by-pass switch q open. Fig. 11 shows a modified arrangement in which the bye-pass valve G is operated automatically through friction discs j<4>, j<5> from a gear wheel j<1> driven by the motor: this action takes place before the clutch lever s<5> engages the main valve spindle. In a further modification a friction disc arrangement is provided at the top of the shaft J to release the shaft J when the lever s<5> has been operated to engage the main valve to the motor drive.