Exactly Constant Speed.
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at All Loads
I T is well known • that centrifu
gal governors do not give a perfectly uniform engine .speed over the whole load range, though. in many cases the variation is not serious. Patent No 549,665 describes-a
g overnor claimed to maintain eXactly the desired speed under all con claim's. The patentee is F. J. Tippen, 21, Orchard Crescent, Coventry. There is a centrifugal mechanism, of well-known type, employing outwardly moving balls (3), which slide the sleeve (5) to the left to close the throttle (1) with a lever (8). So much is standard practice, the essence of the patent being a correcting mechanism.
On the outside of the sleeve (5) is slidably mounted a double-flanged collar (4). which is held in a midway position by light springs. Mounted on a vertical shaft is a friction wheel (2), which is normally just clear of the flanges and is, therefore, unaffected by them.
When a speed-change occurs, however, the flanges move slightly, with the governor sleeve, to one side or the other, coming into contact with the friction wheel and setting it in motion. Worm reducing gears transmit • the motion to a gear (7) which carries, eccentrically, the fulcrum (6) ,of the lever (8). The effect is to superimpose a fine adjustment on the main govesnor action and so to reset the throttle, whereupon the sleeve (4) returns exactly to its original position, in which the friction wheel is once more untouched.
IMPROVEMENT TO WELL-KNOWN VACUUM BRAKE
DATENT No. 549.692 comes from the • Clayton Dewandre Co., Ltd., S. E.
Willett and S. H. Edge, all of Titanic Works, Lincoln, arid discloses an improvement to the Dewandre wellknown servo-brake system. When used in vehicles of the heaviest type, the device, according to the specification, has been associated with a difficulty due to distortion of the vehicle frame, causing slight binding of the cross-shafts, and this, whilst of little moment to the servo mechanism, may interfere with the manual operation. To prevent this possibility is the object of the improvement.
Referring to an accompanying drawing, the pedal rod (5) operates, via a lost-motion coupling, the vacuum valve (3), and the resulting movement of the piston (4) tends to re-close the valve and so to exert a reaction on the • pedal.
The essence of the invention lies in the abolition of cross-shafts between the pedal rod and the primary brake rod (2). lh this design these two rods are practically in line, meeting upon a common pivot pin (1). Frame distortion, therefore, cannot affect this part of the system, so that should the vacuum fail, the brakes will still be freely operable by manual effort.
SELF-STEERING TRACTOR. IMPLEMENTCOUPLING
INEQUALITIES of ground level, or lateral variation in soil texture are only two of the /actors that can cause a tractor-drawn implement to deviate from ith correct path. To correct such deviation automatically is the object of a coupling device shown in patent No. 549,780, by David Brown Tractors, Ltd., H. E. Merritt and C. H. Hull, Meltham, Huddersfield.
In an accompanying perspective sketch the connecting mechanism between the tractor, and the machine is shown. The two bars (6) are universally joined to the rear of the tractor and terminate in a cross-member (4) journaUed on the front of the implement. The cross-member is actually in the form of a two-throw crankshaft, being fitted with pins (3 and 5) angu-,
larly spaced at 180 degrees. •A lever (2) on the cross-membei is universally linked to a built-up rod (1) attached to some -part of the tractor, in this case
one of the arms (6). • Any change in the angle between • tractor and implement imparts partial rotation to, the shaft (4), which then turns about its crankpins and gives an • angular tilt to the implement, the direction being such that it tends to restore the correct relationship. Rod 1 is also_ adjustable manually by means of a lever, so that the driver can avail him. .self of the device at his discretion.
• INJECTION PUMP DESIGNED FOR EASY OVERHAUL 'TO facilitate repairing injection J. piunps. by Others than specialists is the .chief object of an improved pump detailed in patentNo. 548,763 by S. A. Adolphe Saurer, Arbon, Switzerland. It operates on standard principles, the modifications relating only to construction and assembly.
Except for the cover-plate (8), the casing is in one piece. and houses the • camshaft bearings and plunger elements. Each. cylinder ,(3) is held in
place by.a, " closure plug" •(1) which incorporates the pipe union. This presses the assembly on to a
shoulder (9). . .
To remove a pump unit for replacement, the plug (1) is detached, and the delivery valve (2) removed as a whole. Next, the cover-plate (8) is removed, and the camshaft turned until the plunger is in its highest' position.
At this point the spring (5). is at its shortest, and while it is thus .com
pressed, a special retaining tool is placed over it. Then .the camshaft is again turned, leaving the spring with a clear space under it, which enables a. slotted washer (7) to be withdrawn. By its removal the bottom end of the plunger is ,freed.
The cylinder (6) and its plunger can then be withdrawn upwards, and for this purpose the plunger is provided with a tapped hole (10) into which a drawbolt can be screwed.
There is no need to disturb the 'control pinion, whilst the correct position of the inserted replacement is ensured by the projections (6) of the plunger engaging in slots (4) formed in the lower end of the pinion sleeve.
The specification also describes in detail the ,construction of the springretaining tool.