Patent GB-712365-A (GB)
Title: Improvements in and relating to dual fuel internal combustion engines
Inventor: SMITH JAMES MILLAR
IPC: F02D19/10
Filed: 1952-05-02
Abstract: 712,365. Engines using alternate fuels; regulating. ENGLISH ELECTRIC CO., Ltd. May 1, 1953 [May 2, 1952], No. 11150/52. Classes 7(2) and 7(6) A control system for an engine operating on gas and liquid fuel comprises a floating beam B connected by a lever A to the engine speed governor and at its ends to levers C, D, controlling respectively the gas and liquid fuel supplies, the beam B being urged to a neutral position at one end by restoring forces acting in opposite directions and arranged so that the governor first moves the gas control means to a predetermined maximum opening position before causing any substantial movement of the liquid fuel control means. The beam B is connected to the lever C through a link L and at the opposite end to the lever D through a resilient link J, the same end of the beam being pivoted at F to a device E which is adjustably fixed to the engine casing at P and which comprises a spring E<1> which tends to return the pivot F to a predetermined position when it is moved either upwards or downwards therefrom. The levers C, D carry pins C<1>, D<1> which co-operate with adjustable stop levers H, G limiting the maximum gas and liquid fuel supply positions. On initial movement of the lever A the beam B pivots about the point F to move the lever C to increase the gas supply until further rotation of the lever C is prevented by the lever H, the lever D meanwhile remaining substantially stationary in a position in which a small amount of liquid fuel is supplied to ignite the gas charge. Further movement of the lever A causes the beam B to pivot about the end of the link L and move the lever D against the force of the spring E<1> to increase the liquid fuel supply up to a maximum limited by the lever G. A pin H<11> on the lever H ensures that when the lever G is moved to cut off the liquid fuel supply, the lever H is also moved to cut off the gas suppply. The resilient link J yields to allow the lever G to be moved to cut off the liquid fuel supply without forcing the lever A against the governor loading means and the spring E<1> permits the lever B to be moved upwards from the position shown, in which the amount of fuel sufficient for ignition is supplied, to the completely cut-off position. The position of the pivot F may be adjusted in a slot B<1> so that during the pivoting of the beam B about the pivot F the fuel supply is increased slightly. In a modification, Fig. 2, a single member Q has an arm Q<1> acting as a stop for the lever D and a pin Q<11> which co-operates with a slot S in a plate R forming the stop for the lever C. Part of the slot S is concentric with the pivot M of the member Q so that the first portion of the upward movement of the member Q rotates the. arm Q<1> to permit the supply of liquid fuel, but holds the plate R stationary in a position cutting off the gas supply. Further movement of the member Q rotates the plate R to permit the lever C to be rotated by the governor, the operation then being identical with that of the embodiment of Fig. 1.