HYDRAULIC OPERATION OF SPEED GEARING.
Page 32
If you've noticed an error in this article please click here to report it so we can fix it.
A Resume of Recently Published Patenti
An ingenious hydraulic change speed operating gear is described by the AutoGear Shift Co. in Specification No. 160,003. We do not reproduce any of the drawings which accompany this ;specification, as they all contain such a mass of unintelligible detail. The gear consists of an oil reservoir, a main operating cylinder, a distributing valve, and three pairs of subsidiary cylindere, together with the detail mechanism. The distributing valve is controlled by means
of a lever positioned on the steering column, and working over a quadrant. The valve opeee a communication between the main cylinder and two or three of the six subsidiary cylinders, according to the change of speed which it is required to effect. After the valve is set, which may occur some time before the actual change of gear is required, everything remains in statu quo until
• the driver of the vehicle depresses the clutch pedal in order to release the clutch, which may be of any orthodox typeThe clutch pedal lever comenuni-. cates, throng)i a series of rods, with tie rocking lever, the other end of which is in contact with the free end of the piston rod of the main cylinder. As the pedal is depressed, the piston of that cylinder is driven along, and pushes the oil which is within the cylinder, through the distribution valve, to those of the eubsidiary cylinders which are required to operate. One of the advantages of the gear is, according to the inventor, that every preparation for the gear change may be made, so far as the driver of the vehicle is concerned, before. hand, so that, when the critical moment approaches, all that he has to do is to depress the clutch pedal.
Most of the interest Tics in the six subsidiary cylinders, by means of which the actual operations of moving the gears are effected. They work, or their pistons are moved, by means of the oil which is ejected from the main cylinder when the clutch lever is depressed. These cylinders, as we have already indicated, are in pairs. One pair, disposed side by side in a line at right-angles to the main direction of movement of the change-gear actuating rod, operates to pull or push that rod sideways so that its operative end passes across the gate in the MRtomary manner between the two main slots. The other two pairs are disposed
BM in line With the main direction of the movement of the change speed red. Of the two, one pair is. shorter in the stroke than the other, and each of the cylinders of a pair lies in the Same line, acting in opposition to one another. The piston rods of the pair of cylinders which have the shorter stroke acting on a cross-head on the change-speed rod, operate to bring the change-seeed rod to the neutral position; it is then moved across the gate by the piston rod of one or other of the
two cylinders which we have described as being designed for that purpose, and, finally, the pistons of the remaining pair of cylinders, after operating .a trip gear which renclees the cross-head free to move past the projecting piston iaxl of. the adjacent cylinders, push the changespeed rod in the direction in which it is required to go in order to effect the desired change of speed.
As will be readily understood, much of the inventor's ingenuity has been expended on devising a suitable system of locking gears by means of which the various pistons, etc., are only allowed to function at the proper time. The pistons which actually move the change-speed rod into its final position when a change is effected cannot operate until a catch, released by the piston, brings the change-speed rod to its proper side of the gate; the latter piston cannot move, of course, until the change-speed rod has been brought opposite the transverse slot in the gate by another set of pistons, and so on. The whole gear is extremely interesting, but, if we may venture a comment, it is that there does not appear to he any provision for ensuring that, when a, change is attempted, or forced, by this mechanism, the gears which are to be engaged are travelling at the proper speeds.
Other. Patents of Interest.
,Parts of motor vehicles, in order that they may be truly interchangeable, have to be manufactured within very fine
of accuracy. In order to maintain the work at this high standard, it is customary to employ accurate gauges, made of hardened steel. After a time these gauges become worn and have to be repaired. The repair process is rather a tedious and expensive ono, involving hammering out and machining. Rudge-Whitworth, Ltd., have devised is method of carrying out this operation quickly, effectively, and cheaply, as well as in such a manner that the gauge can be corrected and brought to its original pitch of accuracy aa many as from five to tea times. The inaccuracy with which we are concerned results from wear, so that the gauges become less than they should be. According to this patentee they can he corrected, in many cases in one operation only, by squeezing the gauge between a pair of balls or similar articles. The process is clearly described in specification No. 159,947.
P. Lord and another describe, in specification No. 159,975, a magneto driving coupling, by means of which, ,4hen the control of the time of ignition is corrected by hand at the contact breaker, it may also he corrected, through this coupling, in such a manner that the armature, at the time when the spark occurs, is In that position, relative to the magneto, which produces the best effects.
No. 159,937 refers to a homer for the boiler of a steam car. The pilot bur'ner in the arrangement described is burning all the time the car is in use, and its principal purpose is that of completing the vaporization of the fuel which is, by the time it approaches the chamber which is heated by the pilot burner, already partially vaporized by having been passed through a • coil of tube located in proximity to the main bunner. The final vaporizer chamber for the fuel also serves as is collector for carbon or impurities which may have been collected by the fuel, and it is suitably provided with cleaning holes. The patentee is the 'Baker Steam Motor Car and Manufacturing Co
The piston ring which is described in specification No. 159,994, by It. Allen is of the type in which the joints are closed by an expanding plug, while the ring itself is continuously expanded by internal wedge pieces.
G. R. Inehaw describes, in specification No. 159,995, an arrangement of valves in which there is one poppet valve only to each oylinder and a revolving valve. The poppet valve opens the passage to the cylinder for both induction and exhaust, while the rotary valve, directs the incoming mixture or the outgoing gases to the proper duet.