Improvements in a
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Sliding Tilt Body
TBE sliding tilt is a useful form of covering for the van which is to be used for conveying a number of comparatively, heavy articles. It affords practically the weather pptection of the closed van, whilst facilitating the loading and unloading, by crane or by hand, of weighty packages. •A commercial bodybuilding concern which has made a speciality of this class of body is Portsmouth Commercial Motors, _Ltd., Goldsmith Avenue, Portsmouth, and this company has recently improved its tilt-van design.
In the latest model the sliding.tilt is supported on rollers at two points on each side; the rear rollers being at, the base and the forward ones at the cantrail leyel. Each rear Mier is carried between steel plates fixed each side of the tilt frame-member and runs on a T-section steel rail mounted on the top edge of the body side. The steel side
locking the tilt so that it cannot be moved fore and aft The opening or closing of the jaws is effected by threading one end of the roller spindle and squaring the head so that it can be
turned by a removable. key. " The' arrangement is neater and more useful than the old method of employing an external locking device, which would hold the tilt only in certain positions. So as to eliminate any binding between the under side of the T-seetion rail and the extremities of the jaws a single steel ball is inserted in a hemispherical hollow in each jaw, 4 provision which seems to work -well. .
As regards the forward supports for the tilt, the rollers are mounted directly upon the sides of fixed .body pillars and engage in box-channel steel rails fixed to the inside of the tilt. When a crane or hoist is not available and heavy articles stowed at the forward end of the van need to be unloaded without disturbing those at the rear, it is helpful if the body sides can be lowered on hinges. Per this purpose each side is made in two sections, a short fixed section at the front end which is never uncovered by the tilt, and a longer hinged main section.
The front rollers could, of course, be mounted on the windscreen uprights, an arrangement which would perinit the tilt to be rolled still farther forward, but as . it is the common practice to construct the driver's cab quite independently of the 'main body, to allow for chassis flexing, this is not practicable Portsmouth Commercial Motors, Ltd., finds a demand for this type of body for the transport of gas .stoves, fire grates, etc. The tilts, although light, . are Athoroughly weatherproof, being panelled in plywood rwhich is canvas-covered and varnished. FSH arrangements have been made for the marketing in Great Britain of the well-known Cletrac . tractor, the latest models of which incorporate many improvements. Cowan, Hulbert, Ltd., of New Oxford House, Bart Street, London, W.C.1, has taken
up the representation. The Cletrac is selling well in many of the world's markets, and Mr. C. C. Veitch, who has had considerable experience with this make of tractor in East Africa, has joined Cowan, Hulbert, Ltd., especially to organize sales in this country.
The Cletrac tractor with its creepertrack drive is, in principle, well known to a largt number of our readers, but the recent modifications are of an I inter' esting nature. There is now centralized automatic lubrication to all the lower and upper track-wheel bearingS, the front sprocket hearings and track
frame shaft beatings. Twin idler wheels are now employed to prevent track whip, the front idlers being • carried on pre-compressed springs situ' ated -inside the track-frame castings, which tension the track.
The track wheels are of the plainbearing type, positively sealed' against dirt and grit. The rear sprockets are so designed that only every alternate tooth engages. with the track so as to prolong the life of the sprockets.
The track plates themselves have been improved. The part of each Shoc coming into contact with the sprocket teeth is not integral with the shoe itself, but is removable. The track pips, bushings and rollers are made of hardened steel, the shoes being heavy 'drop-steel forgings, and the outside plates and grouters, which are detachable, are made from heat-treated ear. lionized steel. . The engine is equipped with a Purolator, which constantly
filters all oil after -it has passed through the hearings, and the gears run in a constant spray of oil delivered.by a special Ramp with which a filter is incorporated.'
The model 15 Cletrac, which is a popular size, has a iour-cylintlered sidevalve water-cooled engine Of 4-in. bore and 4k-in. stroke, the crankshaft having three main bearings and the pistons being of 'east iron. . There is forced lubrication to the crankshaft, Ceutseet-• lug-rod -bearings and timing. gears. Ignition is by Eisernant magneto, which incorporates an impulse starter. A centrifugal governor controls the speed of the engine.
A Borg and Beck 11-in, single-plate clutch conveys the drive to a gearbou providing three forward and one reverse ratios, the forward speeds ranging from 2.05 to 4.2 m.p.h. at 1;200 engine 1-pat., which is the governed speed. steering • is accomplished bythe effect of the engine through planetary compensating gears ; when one track is _.braked the
other is accelerated. The total. sue. face of the track in contact with the ground is 982 sq. ins., •thc ground pressure per square in.. being only 5 lb:
The overall length of the model15 is 7 ft. 51 ins., the Width being 4 ft. 2i ins., and theground. clearance Jai ins. The turning radius is 8 ft. There is provision for a pulley, also a separate power take-off.
Several Cletrac -tractors are being employed for arduous Work in connection with the extension of the Lender': Underground tab?: railway from Pinsbury Park to Cockfosters.