A VACUUM BRAKE GIVING FOOT SENSITIVITY.
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A Resume of Recently Published Patent Specifications.
MIERNAND L. GODEAU, of Ghent, Belgium, in specification No. 248,172, points out, as the disadvantage common to many vacuum brakes, that the effect on the brake drum is not proportionate to the effort applied by the driver to the pedal; consequently, one is unable to judge the amount of• intensity of the braking effect applied to the drums by the driver's exertion on the pedal, as is usual in the application of an ordinary brake. We fully agree with the inventor on this point and are glad to see it recognised and that efforts are being made in the direction of producing a brake in which the driver can " feel " the effect he is producing on the drums.
In the present case the specification is somewhat difficult to condense into a small space, but, briefly, the arrangement is as follows: The pedal lever, is freely mounted on the brake shaft, whilst a double or bellerank lever is keyed to the brake shaft ; this double lever is provided with a pin at its lower end, which carries a small lever attached to a rod which, by closing a valve, prevents the ingress of air to the ,vacuum-producing device, and by so doing sets up a vacuum. This small lever is brought into action by the adjustable pin mounted on the lower extension of the foot lever.
The first movement of the pedal operates the valve, thus causing vacuum in the cylinder; this causes the piston to be drawn in, and, by means of the link, operates the rocking shaft shown, which in turn operates the shorter of the two levers it carries, and, through the long push rod, operates the bellcrank mounted on the central shaft, and then through the short push rod applies the brake by means of the bellcrank lever keyed to the brake shaft. It will be seen that to keep the valve open it is necessary for the driver to follow up the movement of the bellcrank on, the brake shaft.
The spring which connects the foot lever to the bellcrank lever on the central shaft is so proportioned that its extension exactly coincides with the amount of power being exerted by the vacuum cylinder.
A Method of Keeping Windscreens Clean.
ERNEST THEODORE HOLFORD,
of Mentone, Australia, in specification No. 221,787, mentions a means of cleaning windscreens by forcing on them a jet or jets of compressed air. He describes a tube, which passes above the driver's line of vision, and which is provided with a number of small holes or a narrow slit, so that the air is projected against the glass in a slightly downward direction, which he claims will prevent the rain from obscuring the driver's vision.
A Magneto with Electric Magnets.
SCINTILLA, a Swiss company, in specification No. 239,230, show a form of magneto in which' electro magnets are used in place of the usual permanent magnets, the magnets being excited by means of a battery. The object aimed at is to provide a magneto which will enable the starting of large engines to be accomplished with the minimum number of turns of the engine. An electro-magnetically acting buzzer is used in the circuit of the electro magnets. This forms an automatically acting interrupter of the hammer break type, which makes and breaks the exciter current of the electro magnets in rapid succession, and in this way each time the mechanically operated interrupter opens the primary coil it
SPARK/NG PLOG START in POSITION
JCHANGE-,OVE2 ( SWITCH causes a whole series of ignition impulses to be formed in rapid succession in the secondary circuit of the apparatus. The change-over switch is used when the engine is to be started, but when once running the change-over switch is set to the running position.
A Isiovel Windscreen.
uP to the present time, very little has been done for the comfort of drivers of commercial motors in wet weather, beyond providing them with a glass screen that, when it rains, has to be opened, and the driver has had to put up with the rain coming on him.
Paul de Cignon d'Alincourt, of Paris, in specification No. 241,559, describes
a windscreen that he claims will enable an opening, as showo, to be made which will enable the driver to have a clear view -without draught or rain coming into his face.
It will be seen that the upper part of the screen is made of two portions, one behind the other, and that a vertical and horizontal panel are employed to form a trough into which the air deflected from the lower screen passes, and escapes sideways.
A Novel Front Suspension.
GUIDO FORNACA, of Turin, in
specification No. 248,587, shows a novel form of front axle and suspension, Half the radiator only is shown and it will be seen to be mounted centrally on a rigid cross member, which is formed of a channel-shaped girder and contains the spring.
Tubes form the steering heads. The outer member of the head is provided with a slot which allows of vertical movement for the action of th* spring. The inventor does not very clearly tell us with what object he advocates this departure from the usual design, but it strikes us as being a very good construction where the torque of front-wheel brakes has to be dealt with, as the springs would be entirely relieved of all strains from brake reaction.