AT THE HEART OF THE ROAD TRANSPORT INDUSTRY.

Call our Sales Team on 0208 912 2120

A COUPLE OF VARIABLE SPEED GEARS.

9th June 1925, Page 30
9th June 1925
Page 30
Page 30, 9th June 1925 — A COUPLE OF VARIABLE SPEED GEARS.
Close
Noticed an error?
If you've noticed an error in this article please click here to report it so we can fix it.

Which of the following most accurately describes the problem?

A Résumé of Recently. Published Patent Specifications.

A VARIABLE spied gear is shown in" the specification of R. Erban, of Vienna, .No. 220,331, in which the action common to all ball bearings is employed as a means of obtaining variations of speed.

A number of narrow rollers, each of whieh may be regarded as a section cut from the middle, of a ball, are mounted on axles and are under pressure between two ball races, as shown in both figures. The axles on which these rollers revolve, are held in a member which resembles the cage of a ball hearing. The axles of the rollers can be tilted to any angle between the dotted lines shown in the righthand view' and can be controlled by sliding the collar (D). along the shaft.

The specification is a long one, referring to other patents, but for simplicity we will describe the shaft (A) as the driving shaft, which carries with it the ball race (E), The ball race (0) is mounted on the anchored ease. Pressure is brought to bear between the races (E) and (C) by means of a special device, which is the subject of another patent. This pressure sets up friction between the races, and the rollers, and causes the cage, which is integral with the shaft (B), to revolve at a reduced speed according to the degree of angle given to the rollers. It will be seen that only a limited amount of speed variation can be obtained by this means; so, to increase the range, the inventor employs two or more sets of rollers and races working in series. The specification does not dearly describe how the pressure between the races is relieved during the tilting of the rollers. Of all the various devices 'we have seen which employ the action observed in all ball bearings for a drive, this seems to be one of the most practicable.

A Hydraulic Variable Gear. A HYDRAULIC variable gear is described by E. Vessey in

specification No. 232,998, in which a centrifugal pump is described, having a discharge arranged in such a manner that the escaping,,fluid meets the vanes of a turbine which forms the driven member. The inventor claims that by the use of his invention he may dispense with a clutch, as at law speeds no power will be transmitted.

He also claims that the arrangement may be used to cheek the engine while running down hill, and, further, if the arrangement be fitted to the rear axle in duplicate, that it will do the duty of a differential gear. He describes the gear as being automatic, as at very low speeds no power will be transmitted, but at the full output of power from the engine the gear will automatically increase its torque as the resistance increases, with, of course, a corresponding -de

crease of speed. The specification goes deeply into figures and quotes authority for the inv'entor's calculations.

We shall, however, be interested to see the invention in actual work fitted to a vehicle, eis, at the comparatively Tow speed of a rear axle, we can hardly imagine either the pump or the turbine transmitting any appreciable power.

Springs which Vary in accordance with the Load. A FORM. of spring which, it is claimed, will ride easily with an unladen vehicle, and yet will not be over-loaded when the weight carried is increased, is deseribed in the sped

fication of E. Effingham, No. 233,089. Two separate springs are shown, one above the other, the upper one being the spring which is in action when the vehicle is running light. The lower spring is attached to the upper one only at the middle, as shown. Two levers are provided, which rest on the upper spring near its central holding, and bear on the lower spring at its outer ends. The ends of the levers near the centre are curved so as to have a rolling action where they bear on the main springs, and are provided with a recess to receive a roller at their other ends. We suppose that the levers are mounted on pivots where they join the frame, although they are not shown in this form.

I An Improved Grease Gun.

TECALL.MIT, LTD., in their specification No. 215,025 show

an improved form of grease gun, in which the means for increasing the pressure to force the lubricant into a bearing automatically come into operation as the resistance to the ingress of the lubricant increases. So far as the main body of the gun is concerned it is of purely conventional form, and forms no part of the present invention. A seeond chamber (A) is provided, in which a greater amount of pressure can be exerted to expel the grease than is possible with the plunger of large area used for ordinary grease injection.

The chamber (A), owing to its comparatively small area can exert a pressure which is sufficient to dislodge any spent grease and fill the cup and bearing with fresh grease. In action the operator engages the nozzle with the bayonet slot (C), which makes a tight joint at B. The handle is then turned in the ordinary manner, and, should there be no great resiitance to the entrance of the lubricant, the mein piston acts in the usual manner ; but, should the resistance, thr ough any cause, be greater than the large plunger can deal with, the plunger in the chamber (A) comes automatically into action. A continued rotary movement of the handle sets up a screw action in the threads (D), and, owing to the small area of the piston which acts in the chamber (A), forces the lubricant out under great pressure. A nonreturn valve is provided to prevent the lubricant from returning to the main body of the gun. Such a device as this should be of great service, as grease is prone to clog.

Tags

Organisations: MIT
Locations: Vienna

comments powered by Disqus