THE INFINITELY VARIABLE GEAR.
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A Resume of Recently Published Patent Specifications.
There are two interesting patent specifications this week, both dealing with the subject of transmission, both having as their objective the provision of an infinitely variable gear, and although in application they are as wide apart as the Poles, the principle involved is the same. Advantage is taken of the wobbling which is set up when a revolving disc is displaced from the normal with respect to it driving shaft to convert a retary motion to reciprocating, and this, again, by Various means, according to the specification,
is reconverted to rotation. The variation in ratio of mechanical effort is effected by altering the displacement of a disc from the normal, and thus reducing or increasing the length of the stroke of the reciprocating mcivement.
• Specification No. 122,530 is communicated by a Swede to H. G. Fairweather. The engine shaft, as we have inferred, drives a disc, which, by the operation of pedals and intermediate gearing, is caused to be diverted more or less from the normal to the shaft. About this disc, and supported from it .by ball thrust and journal bearings, is a second one, which does not rotate, but which naturally wobbles with the rotating disc upon which it is carried. From a number of points on this non-rotating disc, rods are coupled to the friction pawls which bear upon discs on the driven shaft, and in this manner is the power transmitted. Two pedals are provided: pressure on one increases the obliquity of the wobbling disc, thus increasing the stroke of the ratchets, and decreasing the gear ratio as between driving and driven shafts.
It will be realized that starting from rest in the neutral position, when, of course, the disc is normal to the engine shaft, and therefore does not wobble, a
n48 gradual pressure on the pedal would cause a slight movement of the ratchets, and thus start the gear. :This would be on the low speed, and the driving torque applied to the axle would be at a maximum. Increasing pressure on the pedal moves the disc further away from its normal position, increasing the stroke of the ratchets and the speed of the gear. The second pedal is provided for the reverse operation, that of reducing the speed of the car, or, alternatively, increasing the ratio. Reverse is provided for by a lever which brings into operation an alternative set of pawls which operate in the reverse direction upon the discs on the driven shaft.
In the other specification, No. 122,442, by P. S. Crowsley, the disc operates upon plungers of a set of hydraulic cylinders, with a disc at right angles to the axis of the driving shaft, that is to say, normal to it, no movement of the plungers takes place, there is no resistance to motion of the disc, and the driving shaft in consequence revolves idly. As the disc is displaced, the plungers commence to move. The cylinders in which, they work, and also the plungers, are fitted with ports and valves of such a nature that an increasing resistance is offered as the
ktroke of the plunger increases, so that with but a slight displacement of the disc and short strokeof the plungers there is but little resistance to the movement of the plungers, the cylinders, and with them the driven shaft are rotated slowly, and the gear ratio between the driven shaft and driving shaft is high. As the displacement of the disc increases, and the speed of movement of the plungers pro rata, the resistance increases also, so that the driven shaft revolves at a higher rata
of speed. Finally, the egress for the fluid in the cylinders is blocked entirely, and the whole mechanism revolves solid, thus corresponding to the top speed gear on a normal transmission.
Other Patents of Interest.
A fortnight ago reference was made to a design of cylinder sold by Dr. T. B. Murray and the Albion Motor Car Co. In two specifications now published, namely, Nos. 122,467 and 122,468, the patentees describe other details in connection with the same improvement. The former relates to the valve gear. The camshaft is carried low down in the same casting an the cylinder. Intermediate between camshaft and valve spindle is a rocking lever, which bears on a shaft carried in brackets depend
ing from the detachable head. The object is accessibility ; the detachable head carries with• it on removal all the salve mechanism, which, therefore, does not need to be disturbed. The other specification deals with the design of the induction passage.
No. 118,407 (Soc. Anon. des 'Ateliers Piecard, Pictet et Cie.) is a rotary engine valve, the important feature being the embodiment of vertical and horizontal slits in the valve, so that it may spring under pressure and thus make better contact with the cylinder wall.
A magneto contact breaker, by G. A. Chailliey, is described in No. 116,879. A complete loop of spring steel carries at one point a movable contact piece, and at another point a projection upon which the cam strikes. Of the four sides of the loop no two are exactly alike. This, it is claimed, eliminates any harmful periodicity, and another advantage is the lightness of the moving parts. A small fitting, by the use of which rich mixture for starting purposes may be induced, is described in No. 122,482, by E. Dobson. , T. Glover, in No. 122,535, patents several modifications of a self-acting lifting jack. F. A. Wilkinson, in No. 122,590, provides air at a high temperature to mix with low grade fuels by fitting a long. copper pipe inside the exhaust pipe. The open end of this pipe protrudes through the side of the exhaust pipe, so as to collect from the open atmosphere, and the other end of the pipe is fitted with a suitable valve, and is coupled to a union in the induction pipe immediately above the carburetter.