Self-energizing Disc Brake
Page 80
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A DISC brake in which the actuating force is amplified by movement of the disc is shown in patent No. 829,866. (Minister of Supply, London.)
Referring to the drawing, 1 is the disc, 2 the fixed friction pad and 3 the moving pad, which is backed by a steel thrust plate. Primary actuation is performed by a hydraulic plunger (4) which thrusts the moving pad on to the disc through rollers (5) and bellcranks (6).
During hydraulic operation the bellcranks act as thrust members, transmitting the force direct to the pad. As soon as the pads make contact with the disc, they attempt to move circumferentially. Assuming the disc to be moving upwards, it takes-the pad with it, and this action, applied to the sloping edge (7) of the bellcrank, is converted Into extra thrust as the bellcrank pivots about its pin (8).
If the disc moves in the opposite direction, the lower bellcrank acts similarly.
LIVERPOOL'S REFUSE-COLLECTOR A REFUSE -COLLECTING vehicle L-1.. shown in patent No. 829,416 provides weather protection for the crew, makes their work easier and minimizes dust dissemination. The patent comes, from the Lord Mayor, aldermen and citizens of the City of Liverpool, and E. Haughton, " Redlumbs." Scarth HiU, Ormskirk, Lancs.
The tipping body is mounted on a semi-trailer. The tractor is of unusual layout, having the engine and transmission immediately ahead of the rear axle as shown at I. This permits the central section of the chassis frame to be dropped to support a loading platform.
The crew stepup on to the platform to empty their bins into a hopper (2) which, when full, is cleared by a pusherplate (3) moving into the position 4. The 'plate is actuated by an hydraulic ram (5).
Weather protection is afforded by the canopy (6) over the loading platform and tip-up seats (7) are provided for the crew when travelling. A rack (8) is fitted under the frame to carry large pieces of salvage that cannot be placed in the body. The body is tipped by a ram (9) for discharging.
The loading hopper and its mechanism do not rise with the body, keeping the centre of gravity as low as possible for stabiliy.
VIBRATION DETECTOR
AN instrument for detecting the presenceof damaging torsional vibration in the crankshaft of a running engine, is the subject of patent No. 829,300. (M. Prochazka, 21 Tuchomerice, Czechoslovakia.)
The device illustrated can be built into the crankshaft of an oil engine. It is a robust unit, unaffected by axial vibrations, and functions satisfactorily even if filled with engine oil. It will detect vibrations of a frequency of 5,000 per minute or more.
A cylindrical permanent magnet (1) is attached to the crankshaft. This is magnetized diametrically so that its lines of force pass through a non-magnetic sleeve (2). The outer Magnetic circuit is completed by an iron ring (3). The sleeve is freely journalled so that it cannot vibrate torsionally. It contains windings (4), the ends of which are brought out to an electric instrument not specified, but which indicates small voltages.
In action, all the parts revolve as one and no current is generated. Should the shaft oscillate torsionally, the windings act as a dynamo that is rocked to and fro, and current produced -by this movement is indicated.on the voltage meter. • SELF-ADJUSTING ROCKER
AUTOMATIC valve clearance adjustment is provided by the invention shown in patent No. 829,737. • It is intended for engines with push-rodoperated overhead valves. (Ford Motor Co., Ltd., 88 Regent Street, London, W.I.)
The drawing shows the rocker which moves about a pivot (1). The rocker is made of high-strength light alloy. The push-rod engages a bore in the boss (2) whilst the Valve stem abuts against the underface of a member (3).
This member is part of an eccentric and rocks about the cylindrical surfaces (4). It is loaded . by a spring plunger (5) which is kept full of oil from the lubricating system.
The eccentric is made of steel, casehardened on its working faces. Its lower. face is of involute outline and, during movement, rolls on the stem of the valve. The patent gives a full description of the geometry of this action.
INJECTION PUMP TIMING
DATENT No. 828,186 comes from
Continental Motors Corp., 205 Market Street, Muskegon, Michigan, U.S.A., and deals with automatic injection-pump timing. The pump is driven through a hydraulic coupling which has interleaved driving and driven vanes, with liquid in between.
By admitting liquid to one side and taking it from the other, the angular position and therefore the timing can be altered. A hydraulic device, responsive to engine speed, performs this operation.
FRICTION MATERIAL
A FRICTION material for brakes I-A and clutches is shown in patent No. 829,236 by Bendix Aviation Corp., South Bend, Indiana, U.S.A. It is said to reduce the tendency to grab and chatter. The material consists of a ceramic substance embedded in a metallic matrix. The latter may comprise copper and a wear inhibitor such as bismuth or antimony.