British Berna.
Page 40
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Tip Wagon. Road Tractor.
Chassis. Lorry.
STAND No. 42.
BriLish Agents: British Berna Motor Lorries, Ltd., Guildford.
THE exhibits shown on this stand comprise a 4 ton Berna chassis, model G3, a 4 ton tipping wagon, with engine-operated tipping gear, and a 2i-3 ton model E3 chassis, carrying a platform body fitted with stanchions and chains. The last exhibit, and one whieh is proving of considerable interest to visitors, is the Berna road tractor, which is similar in many respects to the new Barna agricultural tractor.
Of these vehicles, model E3 has a monobloc engine of 100 nun, bore and 170 min. stroke, with the ordinary typo of beveldriven veer axle provided with a long, tubular, spherically ended torque member containing the propeller shaft. An interesting point about this mastrine is that it is fitted on one side with Michelin steel wheels and pneemsatic tyres', and at the other side with wood • wheels and
solid tyres..•••
The 4 ten stripped chassis deserves a minute inspection. It is a very fine example of Swiss, enginefor4.• production.
The frame is constructed with premed channel section. side members:. of great depth, and tapered to rear and.front. us addition, strengthening plates are riveted on the outsides of these side members. A very long,sub-frame, which is rigidly secured to the maia frame, carries the engine and gearbox. The former has four cylinders cast in pairs and L-headcd, the valvas being at the near side. To prevent the engine being over-run, the centrifugal governor, which operates on a separate throttle in the induction pipe, is carefully sealed so that, the driver cannot. tamper with it without giving away the fact that he ha e done so.
Carburation is effected by a ClaudelHobson accessory designed. specially for this machine. It is provided with a. copper air pipe engaging with a muffle round the exhaust connection. The magneto is one seldom seen in this country, and is known as the Scintilla; se fax as accessibility is concerned, this is one of the finest productions we have seen. The contact breaker points are stationary, and can be examined, and adjusted with the minimum of difficulty. The carbon brushes are situated at the top of the magneto, and can be removed for inspection or cleaning in a moment. An improvement which has been made in this engine is the provision of a combined oil filter and breather of much larger dimensions than .formerly. The oil filter is also particularly accessible, and
can be taken out for cleaning by the removal of one screwed cap. Huge ball races are employed for supporting the crankshaft, and the whole power unit is three-point suspended on the sub-frame. The radiator is constructed of brass, and is of the honeycomb type, cooling being by a fan partially enclosed. From the engine the drive is taken through a. cone clutch covered with leather and a long clutch shaft with a laminated steel disc, flexible joint, to the fouraspeed-andreverse gearbox which is situated amidships. At the rear the gearbox is supported by a. powerful "pressed steel cross member. The cover of the gearbox gives the maximum opening, and by it is carried the pinion which meshes with the primary gear and drives the speedometer. A very powerful footbrake, with external-contracting shoes, operated by a vertical shaft, carrying double earns,. is situated behind the gearbox. The propeller shaft is enclosed in a tubular torque member, the front end of which
is -erirtriVy-shaped and supported in a
spherical housing hold in a cross-member.
The rear axle is the well-known. Berne,in which the load is carried by one member, and the driving is done by another.'
The load-carrying member is a stout. lag; this also carries the differential, from which shafts provided with spur' gears at their miter ends drive the wheeli` through the medium of internally toothed trings. The. first reduction is by bevels,. This double type axle presents many advantages ; included amongst them are extra ground clearance, legs stress on the differential shafts; a considerable reduction in unsprung weight, and the mitxtmum accessibility.
Surrounding the internally toothed' rings in rear wheels are brake drums of large diameter, on which operate brake shoes of the internal expanding type.
This vehicle is powerful ertetigh to be used with a trailer,. aniljorthig. purpose is provided with -a :stout sprung towing hook. There are Many Mirror details in the chassis which shark, careful design and accurateaworkinans'hip for instance,the method'of II:ticking, the selector rode, so that two sets of ,gears cannot be in mesh at the -Same time, is neat and efficient. It consists of a horizontal 'forks pivoted at one end and passing antind the selector lever at the other when the latter moveslaterally, the locking 'fork, which carries
two locking keys, 'swings to one side or the other, as the case may be, the keys holding one of the selector rods so that only the other can move. •
The tipping vehicle is proving of great" interest to those persons who have reason to utilize this type of vehicle, and ParticularlY to municipal authoritie-s, who are, perhaps, the biggest users of this type of machine. .
We have already stated that the gear is engine operated, and one of the chief points about it is that the holy can be tipped to either side or end way!. For show purposes, the tipping gear is being operated by an electric motor; are, of course,, engines are not permitted to be run in the premises. We hope to deal further with this gear in the near future.