A SELF-REGULATING CHANGE-SPEED GEAR.
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A Résumé of Recently Published Patents.
Specifications No. 133,286 and No. 135,82'7, both by N. J. E. Andreau, cover, claims for an *cyclic changespeedl gear which is self-regulating, in accordance with the.demands for driving torque. The external wheel of an epicyclic train is mounted on the engine shaft: the planetary pinions are carried by a spider which is secured to the driven shaft. There is no sun wheel, but, in some descriptions of the gear, a double ratchetgear is mounted on the driven shaft, by means of which the gear may -be made effective in one direction or another.
To each planetary pinion is secured a short lever, at the outer end of which is a weight or at least there is the equivalent of such an arrangement. The levers and weights are all alike, and are so disposed that the unbalanced oentri:. fugal,forces due to the revolution of each about the axis of the pinion act simultaneously to sway the spider either in one direction or another. The working • of the device is as follows. .
Assume that the driven shaft is pre
vented from revolving, either by the opeation of the nine:I:type of brake, or by the selector gear. In that ease the planetary pinions' are driven round by the engine, the spider n-emaining stationary. Beyond the frictional resistance to motion of the pinions on, their bearings, there is in such case no loss of power, as the effect of the unbalanced-forces is not felt by the engine, but is teansinitted, through the ratchet gear of the selector mechanism, to the frame of the gear itself. Take off the brakes, or relieve the selector from the restraint of one of the ratchets, thus freeing the driven shaft for motion in one direction only, and the unbalanced force then commences to have its effect on the spider. As the speed of the engine will naturally he increased, by opening the throttle or other customary means, the pinions will commence to revolve with considerable speed, increasing the effect of the centrifugal force due to the unbalanced weights, and, under the influence of this force, the spider will commence to move, and the vehicle to get. under way. As the vehicle gathers speed; the rate of revolution of the pinions will decrease, until, when the speed of the spider is the same aa that of the , engine, the drive will be a direct one. Whenever the resistance to motion of the vehicle is increased beyond that with which the engine can deal on direct
drive, its speed will naturally eerie D413 mence to drop, whereupon, as the engine speed will be maintained by opening the throttle to its fullest extent, movement of the planetary pinions will recommence, and the unbalanced forces will again become effective, to increase the (Living torque.
When it is desired to slow the vehicle.
the throttle will be closed, Whereapon the engine shalt will tend to run slower than the driven shaft or spider. This will again cause the pinions to revolve. The selector!, gear' is then reversed, so that the . unbalanced forces operate in a contrary direction, arid at as a brake on the motion of the car, Left in that position, they will ultimately cause the car to reverse.
Detail Improvements.
A wheel guard for motor vehicles is the subject of No. 137,407, by W. C. Croxon. A vertical framework is carried "by brackets fixed.to the chaisis. Pulleys are attached; to the frame at its upper and lower,, extremities, and round ..them is . wound an endless belt, a littlewider than the wheel whichis to be protected. The ,frame is, hinged at the top, and maintained by springs in such a position that normally the rear aide of the, belt is quite clear of the wheel of the vehicle. On meeting with an obstacle, it is forced backwards, the belt' comesinto contact with the wheel, and commences to fun round the pulleys, thus causing the obstacle to her thrown away from the vehicle. Provision .is made for the movement of the guard in conjunction with the front wheels as the vehicle, is steered out of the straight, and a safety rack between the wheels may be incorporated, being let down autothatically so soon as the belt, after making contact with the wheel, commences to move.
An interesting type of rotary valve is described in specification No. 137,485,.by T. B. Tutton. As shown on the drawing, it is adapted for use in connection with a monobloc engine, the valve running along the whole length of the cylinder casting. It is a. large diameter cylinder,. hollow, with the inside, the exhaust valve as it actually is, sur rounded by a jacket which acts as the induction valve.
The type of commercial vehicle body which is described in specification No. 137,369, by G. Taylor, is one which is ad. mirably adapted to the purposes of a country carrier who must make provision for the accommodation of passengers as well as goods. The floor level of a super • structure which resembles closely an ordinary char-a-bancs is lifted to the extent of about 2 ft., steps being provided', whereby the passengers can easily ascend to its level. Below that floor is a, coinmodffius locker or series of lockers for
the accommodation of the goods. •
L. 0. W. Shire and the Birmingham. and Midland Motor Omnibus Co., Ltd., point out, in specification No. 137,358, that Where buses are of the frent-entrance type, there is a risk, in the cases.' of the vehicle accidentally 'falling on thatside at which is the entrance gate, • of the passengers being trapped, and that in the case of fire breaking outs the. consequences might very well be serious. .
In the design of body which they patent under that specification, provision is made for an emergency exit ,being made at the rear. Access to it is afforded by lifting a portion of the rear seat of the bus.
F. P. Griffith suggests, in No. 137,338, the incorporation in the design of an aericultural tractor of a small dynamo or air compressor, the. caierent, or air .from which might be utilized to drive a mow
ing machine, -binder, or other limpidmenti of similar nature, which requires power for its proper operation. Alldays and Onions, Ltd., describe the method of cooling their well-known radial
engine in specification No. 137,1139. A light jacket almost entirely envelops the cylinders. In it are formed ducts or
sages, through • which air is drawn by a fan,, and caused to impinge on the ex
terior of the cylinder walls, which, are so designed as to be able to takes the fullest advantage of thecooling effect of the air.