The delivery valve consists of a sliding body with a conical nose, held on its seating by a spring. When the fuel pressure rises, the DLLA138S1191 valve is lifted from its seat and allows a small amount of fuel to pass through the small holes. These, however, cannot deal with the whole amount, and the valve body is, thus, forced higher until the close-fitting rim is clear of the bore, after which the fuel can freely pass.

At full output, the delivery valve is lifted enough to lift a heavily spring-loaded washer, and it is this loading that provides an instant release at the end of injection. The full line pressure is not maintained after injection, however, as the leaks allow the pressure to fall to a value dependent upon the weaker spring. This feature reduces the possibility of dribble, without unloading the pipe-line to an unnecessarily low value that would have to be built up on the next injection stroke.

The two are retracted, but if the disc be turned, they move from a tangential to a radial position and, in doing so, project beyond the tyre. The patent also deals with automatic mechanism for altering the position while running.

The rotary valve is carried in rigid bearings supported by uprights from the crankcase. The ports in the valve alternately connect the combustion space with the inlet and exhaust ports in known manner. The cylinder nozzle block, with its upper half-bearing, is guided by sliding supports and is urged upwardly against the valve barrel by a single spring-loaded bell-crank. This not only presses the cylinders upwards, but also imparts a side pressure on to the guide faces. The valve barrel is internally water cooled.

The diaphragm is connected to an elongated port in the induction tube. This port is half-covered in the idling position, so that full suction reaches the diaphragm, giving full advance for idling. When the throttle is opened slightly, the spark is retarded, but is gradually re-advanced as the engine speed and load rise.

It is proposed to unite the friction material and the shoe permanently by die-casting. The shaped facing is placed in the mould, and the molten metal is poured in. The heat of the metal performs the additional duty of curing the friction material.