The B.W. Governor Now a British Product
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ORIGINALLY manufactured in America, the DAV. Handy Governor marketed by Benjamin Whittaker, Lt., Victoria House, Vernon Place, London, W.C.1, is now entirely made in this country. The device is designed to be bolted-up in the carburetter joint between this component and the induction pipe, and is operated by the speed of gas flow.
It is self-contained and is not connected with any other part of the engine. Available in forms suitable for Practically every type and make of petrol engine that is employed by. the leading commercial-vehicle manufacturers, its price is £6 10s., and it is a definite safeguard against running an engine above its maximum safe speed, thus lengthening its life and reducing petrol consumption.
Simple and with few working parts, the device operates as follows
throttle valve in the gas passage is mounted on.a. spindle (set to one side) with the major portion of its area beB.46 low the spindle, and is normally held (in the open position) at an angle of about 30 degrees to the axis of the induction pipe. Thus the flow of gas exerting pressure on the valve sets up a torque in the throttle spindle. This is resisted by a spring acting upon an arm on the
spindle, through a lever having the side, which bears upon the end of the arm, shaped to a special contour.
The arrangement is such that as the spring yields to the torsional force set up by the gas flow the mechanical advantage (provided by leverage) that the spring has over the spindle arm increases with great rapidity. Thus, as the valve closes and in doing so increases its angle, thereby being subjected to greater side pressure, the resistance offered to the rotation of the spindle gains magnitude too, and at a proportional rate.
The result is a balanced movement of tho throttle valve, the effect of which is gradually to restrict the passage of gas above a predetermined speed and, by so doing, to prevent the engine from exceeding a given number of r.p.m.
A dash-pot device is incorporated at the side of the gas passage, its function being mainly to exert a damping influence on the valve, and provision is made for adjustment of the spring tension.