ELECTRIC BRAKE

Hawera Star, Volume L, 17 May 1930, Page 13

ELECTRIC BRAKE

STEERING WHEEL SWITCH. A system of brake operation for motor vehicles that is likely to prove of considerable value to motor engineers is the invention of two electrical engineers in Birmingham. . The new system is simple and is worked by electric -power from the battery of the car. It can be used as an additional means of applying the existing brakes, and it leaves the hands free for steering. Any desired degree of pressure can be controlled by the driver through an easily- operated ring on the steering wheel, and the brakes may be jammed on suddenly or applied more gently than is possible with pedal control. In addition, it can be switched off, leaving the brakes under the usual controls. The device may be used on either band or foot brake or both. The current from the battery is led to an electric magnet through a series of resistances operated by the control ring. The resistances regulate the amount of attraction in the magnet which in turn operates on a lever on the brake cross shaft and transmits the braking power to the brake shoes.

The system absorbs very little- current and is in now way a strain on the battery. Tested on a 12 horse-power ear all four brakes were applied fully by less than 20 amperes from a 12 volt

battery, which is only a little more than the consumption of the lights. How many ever havb considered the relationship between skilful clutch use and the car’s riding qualities?

The answers are obvious when it is recalled that nine drivers out of every ten utilise the c-lutch lor just three purposes: Engaging it to transmit power from engine to transmission. Disengaging it to interrupt that • power. Disengaging it and engaging it in 1 gear shifting., The clutch, used a.s a brake, can be of great-assistance to the driver. Most motorists know that an engine, especially if it is of high compression, can be a most effective brake. It will not bring the car to a dead standstill, but it wdl greatly retard the car’s speed. This is done "merely by removing the foot from the accelerator. The engine then starves for air and gas and the action is .such that the car itself is forced to keep the engine in rotation a°ainst the latter’s resistance (compression). How the clutch figures in tliis process is simple. The clutch, broadly speaking, is the coupler between engine and rear driving wheels when the transmission is set for any one of the gear combina. it ions. The arrangement is the same whether the ear is going forward 01 backward, but for the sake of simplicity consider the forward motion only. It would seem that it the clutch were disengaged the car would run. so free that all opportunity to utilise the engine for braking purposes would be sacrificed. This, however, is not the case. The minute: an idling engine is released from the car, through declutching, its speed is reduced to a minimum. If”’then, the clutch is- engaged again the pistons of the engine will resist the sudden speed they are forced to tiavel. This greatly increases the engine s braking effectiveness, and if the process is repeated several times in quick succession the reduction in the- cai s speed will be surprisingly rapid. Snell a process is not- recommended for daily use, hut it does well illustrate the point that closer acquaintance with the clutch gives to the driver additional safety factors which will serve him effectively in an emergency. One of the most annoying of clutch troubles—that of dragging clutch plates —can be remedied by “burning the clutch a little. This is done by setting the car’s holding brake and letime* in tlie clutch slowly while the engine runs. The effect of this process is'to cause the clutch plates to slip, rubbing off the rough or gummy siufaees causing the dragging. 33v judicious use oi the clutch it is possible and advisable t-o save the uni-