MANY NOVEL FEATUR A NEW LOW-LOADER.
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Exclusive Information Regardin Transverse Engine, Right-ang Platform Cc :on Low-deck, which Embodies mission by Worm Gear and vith Frame.
THEREhas been proved to exist a consid‘nrable market for that type of vehicle which can afford a large platform area for loading, whilst being capable of running satisfactorily on good-class roads with a comparatively low power-weight ratio, at the same time the employment of small wheels permitting a low load-level and satisfactory running speeds without excessive gear reduction. Several of such vehicles, differing widely in their detail characteristics, have already been placed on the market, some with a considerable measure of success.
We are now able to describe to our readers another most interesting type known as the Low-deck and built by Corber and Heath, Ltd., Darenth Road, Dartford, Kent. This vehicle is not quite complete, but will be on the road within a few weeks. It is a 2i-totiner, but it is intended to construct others following its general design, making a range up to and including 6-tonners.
Purposes of the Design.
The main objects in designing it were to provide a lorry having a very low load-line and a larger platform than is possible with the ordinary type of vehicle without there being undue overhang at the back, whilst the comparatively short wheelbase and front wheels having a large lock would permit the vehicle to manceuvre in narrow streets and congested thoroughfares. It was desired to dimension it so that existing bodies of horsedrawn railway wagons, or those of other vehicles of a similar, type, could be placed directly on the vehicle frame without any alteration, except for discarding the shafts and axles. It was also considered necessary that long articles which would occupy the whole length of the vehicle could be carried. Simplicity and interchangeability of parts were considered essential, and comparatively low primary cost, combined with low maintenance was, of course, an important factor.
Now, let us see whether these objects have been attained, and to do Sci it will be necessary first to describe the vehicle in a general manner.
It consists of a frame of channel-steel members built out to the full width of the vehicle, thereby cutting out body cross-bearers and members for supporting the floor, which, in the Low-deck, is supplied with the chassis and forms an integral part of it. Actually, the floor members, which are carried longitudinally, lie immediately below the level of the top flanges of the frame side members, so that these flanges act as sills and both bind and protect the floor. Brackets on the side members permit the employment of body sides and
tailboard, either fixed permanently or arranged to hinge. There are five main cross-members, the finst and third serving to carry the front-spring brackets and the two at the back those for the rear springs. Channel-steel ties pass from the inner rear ends of the side members towards the' front of the frame and, on their way, are secured to the cross-members, strengthening these in the immediate vicinity of the spring brackets. An angle-steel member jutting out from the rear of that cross-member which carries the frontspring rear brackets rests upon these ties and serves to support the rear of the gearbox.
The engine is mounted transversely at the front of the chassis, and, at its inner end, has an extension housing containing a right-angle drive by D.B. worm and worm wheel, there being no gear reduction. The drive is then taken through a single-plate dry clutch and two Hardy flexible joints to a four-speed gearbox, built under Dux patents, the gears of • which are in constant mesh, gear-changing being effected by dog clutches. Incidentally, all the shafts are of large diameter and very short.
Behind the gearbox is an open propeller shaft;thaving two Hardy joints, which conveys the drive to a Kirkstall axle with David Brown overhead worm gear. This axle is of the pot type and fully floating. The front axle is also a Kirkstall component, but whereas the rear brakes are hand-operated, those on the front wheels have hydraulic control, broughtinto use by a pedal; all the wheels are, however, interchangeable.
The springing is excellent. The front and rear springs are interchangeable, practically flat under load and with a length of 4 ft. 8 ins., the width being 3 ins. Pneumatic or solid tyres can be used as required, the solid tyres being 5 ins, wide for 20-in. rims. 4 Driver's Position and Controls.
Reverting to the frame, at the forwaril end there is a dropped portion carried under the main frame and slightly narrower, so that for bus work a step can be provided at the near-side front. The positioning of the engine, right-hand drive and controls is such that the driver is accommodated at the off side in the natural position, whilst a clear space, 2 ft. 10 ins, wide, is left at •the near side; this permits a continuation of the platform, provides a bigger loading space and permits the carrying of objects stretching the whole length of the vehicle.
As so many designs of vehicle are in use with the standard controls, it has been thought advisable to embody these. The hand brake and change-speed levers are at the left of the driver ; next in order come the clutch, brake and accelerator pedals, and, slightly to the right of the driver, the steering wheel, which is provided with a ball handle so that it can be held either by the handle or by the rim, according to the driver's wish. The height of the platform is 27 ins. and the clearance beneath the engine and gearbox is 101 ins. In the case of the smallest model, which has an 8-ft. wheelbase, the overall length is 15 ft. 6 ins., whilst the overall width is 6 ft. 3 ins. The radius of the turning circle in this model is 13 ft. 2 ins, ; in the longer types, varying from 9 ft. to 14 ft. wheelbase, the radii of the turning circles vary from 14 ft. 7 ins. to 21 ft. S ins. The track is 4 ft. 10 ins, at the rear and 5 ft. 1 in. at the front.
Having dealt in a general manner with the chassis design, we will now go into further detail, The power unit has four cylinders of 73 mm. bore by 130 mm. stroke, developing 25 b.h.p. at 1,300 r.p.m., to which speed it is governed and then gives the vehicle a road speed of 14 m.p.h. The cylinders are cast en bloc,
having large water spaces and detachable heads. The crankcase is of aluminium, and an important point is that the bearings are in the upper half, which also carries the crankcase arms by which the unit is threepoint mounted direct in the frame, so that the bottom half forming the sump can be dropped without disturbing the whole engine. Incidentally, to permit greater accessibility, an extension shaft from the bottom of the steering gear passes across the chassis to the drop arm, which is at the near side. A 40-ton high-tensile steel stamping is employed for the crankshaft, which is drilled for forced lubrication.
Stainless steel is employed for the valves, which are _all at the near side, inclined and readily adjustable. The cap casting of the front main bearing also carries the extension of the oil pump body, the actual pump being submerged in the sump. It is driven by a spiral pinion engaging direct with the crankshaft pinion. There are no external oil pipes.
Arrangement of Right-angle Gear.
At the rear end of the crankshaft is a flywheel-type stabilizer, to (lamp out periodic vibrations, and to the outer side of this is bolted and spigoted the flange of a shaft carrying the driving pinion of the worm-type right-angle gear. The extension of the warm spindle is carried in Hyatt roller bearings and passes through the casing to form the power take-off, which is then, as will be seen, direct from the crankshaft and provides the maximum efficiency, whilst the large space available at the point where it protrudes enables the driving of large pumps, air compressors, winding gears or hydraulic tipping mechanism, and this without encroaching in any way on the body space proper.
An interesting feature in connection with the engine lies in the fact that whilst the permanent starting handle is mounted at the front of the vehicle, if it be desired to park a vehicle of this type close to another one, the starting can be effected from the off side, a detachable handle being provided for this purpose. This is a point that should make a strong appeal to c34 those whose storage space is restricted or whose vehicles operate in awkward places. The petrol consumption should he one gallon for ' between 15 miles and 17 miles, and the oil consumption one gallon per 1,000 miles. The gear ratios are :—Top, direct; third, 1.7 to 1; second, 2.8 to 1; first, 4.8 to 1; reverse, 3,9 to 1. . In the rear axle the driving shafts are of nickelchrome steel and run on large ball bearings, whilst the hubs (both of front and rear wheels) are carried on heavy Timken taper-roller bearings. Timken bearings are also provided for the stub-axle pivots, the pins being inclined to provide, with the inclined wheels, a near approach to .centre-point steering; actual centrepoint steering has the disadvantage that it is apt to cause wheel dither.
Important Details and Comparisons.
I The steel-disc wheels have extra strengthening plates, as shown in our arrangement of the front axle, and the lock of the front wheels is 45 degrees.
The steering gear has a complete phosphor-bronze worm wheel and a simple form of adjustment is incorporated for taking up backlash. The petrol tank is of lead-coated steel, with internal baffle plates, and is carried on the dash. It holds six gallons of fuel. Chassis lubrication is by means of Enots oil-gun system. Carburation is effected by a Zenith instrument of the horizontal type and ignition by a Simms S.F.4, driven through a Simms vernier coupling.
Provision has been made for accommodating a dynamo. This is supplied as an extra and is driven direct from the power shaft. The driver's seat, engine, tubular radiator, petrol tank, change-speed and brake levers, etc., occupy a floor space of 3 ft. 4 ins. by 3 ft. 6 ins. This compares most favourably with that of an ordinary lorry, which, in a typical vehicle of 2-ton carrying capacity, is 7 ft, 9 ins, by 6 ft. 6 ins. Other interesting comparisons between a standard 21--tonner and the 21-ton low-deck are :—Platform space behind driver's seat, lorry 7 ft. .9 ins., Low-deck 15 ft. ; platform space at side of driver, lorry nil, Low-deck 9 sq. ft.; total floor space available
for load carrying, lorry 461 sq. ft., Low-deck 99 sq. ft.; unladen weight, lorry 2 tons 5 cwt., Low-deck 1 ton 5 cwt.
This vehicle should be highly efficient, for on top gear the power passes through two sets of gears only, both being of the highly efficient D.B. worm type. Tests of this gear have shown an efficiency of 97 per cent. The main features of this interesting vehicle have been protected; whilst the employment of well-tried units bunt by well-known makers ensures both re
liability and interchangeability. The units have, of course, been suitably modified to meet the special needs of tile Low-deck; but these modifications have not affected their design except in a few details.
We are looking forward with great interest to an early opportunity for testing the capabilities of an example of the Low-deck in actual service.
This type of vehicle should be suitable for houserefuse collection and other municipal work: delivery vans, in which provision can be made for a sliding door at the side of the driver's seat ; bus work, as an adequate entrance can be provided at the near-side front ; seaside promenade work and for 'the handling of bulky or heavy loads where a low load-line is of advantage.
It is claimed that a vehicle of this type, with an engine of small power, combined with a low gear ratio, enables the carrying of a 2k-ton load at little more than the running costs of a 1-ton lorry.
The retail price of the 2i-ton Low-deck will be approximately £450, and it must be remembered that this is complete with the platform body, the inclusion of which greatly reduces the cost of a sided vehicle if this be required, the saving being about £20. The platform would also be used as the floor of buses or other passenger vehicles.