"The Motor"dated 23 September 1924
Extract from The Motor September 23rd 1924
The Austin range for 1925 comprises their well tried models of 7hp,12hp &20hp, the principle alteration on the larger cars being the fitting of four-wheel brakes and the introduction of the new 20 hp saloon, while the smallest model has been improved in appearance, slightly enlarged and modified in certain respects.
The four wheel braking
system on the 12 & 20 hp models is of the Austin Cos own design and has
been tested out during the last 12 months. It is extremely simple and neat,
the front brakes and their actuating mechanism being fitted as a complete
unit and being independent of the frame. Passing through the center of the
swivel pin is a rod, the lower end of which is attached to a hardened steel
wedge, which is , of course, located in line with and below the swivel and
is free to revolve with the central rod, this wedge when forced downwards,
comes in contact with pads on the lower end of the two brake shoes, which
are thus caused to expand against the front wheel drums. The upper ends of
these shoes are separately pivoted, while the return spring is mounted on
their lower side. The central rod is depressed by a rocker arm housed on the
stationary portion of the axle, the striking end of the rocker, which is entirely
enclosed in a greasetight box, being rounded off so as to remain uninfluenced
by the turning of the rod caused by the deflection of the steering wheel.
Preventing oil from reaching the shoes
The other end of the rocker shaft carries a second arm attached to a cable leading back to a link hung from the frame, and the connection to the principle cross brake shaft is carried by a rod from the point, the length of the cable being introduced to allow for the movement of the spring. Provision is made by greasegun connections to lubricate the top and bottom bearings of the wedge-ended rod while a pan to prevent and collect oil droppings from reaching the brake shoes is located below the bottom of the shoes and drains the oil out onto the road. The wheels are slightly inclined to provide approximately center pivot steering, while both Ferodo-lined steel shoes are actuated by equal leverage.
The front brakes are compensated in relation to those at the rear, but neither set of rear brakes is compensated with reference to those on the off side. The compensator is located immediately behind the pedal connection and incorporates a hand adjustment, by means of which all brakes can be taken up or loosened out. From this compensator two rods lead back to the cross-shaft the top of the rod being connected to the front brakes and the bottom to the rear. The horizontal controls are carried out in two stages, the first utilizing rods with adjustable ends, and the second cables of fixed length.
The pedal controls all four brakes, while the hand lever is the same as that used before and applies shoes to a drum mounted behind the gearbox, the rotation of a double quick thread drawing in the shoes together.
The front axle has been specially strengthened for the job and consists of a I-section beam with holes for carrying the shock absorbers. On the 12hp axle a jack pad form part of the design, and is a feature which should be appreciated by practical owners. On the Twelve, too, the drums are some two inches smaller in diameter than those used on the Twenty, a further point of interest being that the design on both cars is such that the control of the front and rear brakes is arranged in such a way that should one set fail the other will continue to operate