A GARNER LOW-BUILT BUS CHASSIS.
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Designed for 26-seater Bodies, this New Model Incorporates Many Excellent Features, Including Four-wheel Brakes, Strongly Braced Frame, Three-piece Propeller Shaft and Much-improved Springing.
IN OUR issue dated May 5th of this year we gave full particulars of the new 2-ton Garner chassis, and we referred to this chassis as being an outstanding example of English design embodying high quality, simplicity and economical running, with comparatively low first cost. Many of the features of this chassis showed remarkable capabilities in design, and after a close inspection of the new low-platform bus which has just been built at the Garner works at Moseley, Birmingham, we are convinced that this vehicle
will have an outstanding success, for not only does it embody the many desirable features of its prototype, but to them are added others which should make it a most efficient and safe type for passenger transport.
The chassis is designed throughout to meet the regulations proposed by the Ministry of Transport, and 11 ins. clearance is given for 14 ft. 6 ins, from the front. The frame height loaded is 2 ft. 1 in. The main dimensions are:— Overall length, 23 ft. 3 ins.; wheelbase, 14 ft. 6 ins.; overall width, 7 ft. 3 ins. These dimensions chiefly concern the body. The chassis width over the hubs is 6 ft. 11 ins., and the front and•rear tracks are 15 ft. 8 ins. and 5 ft. 7 ins. respectively. The chassis has been tested at a speed of over 40 m.p.h., carrying its full load, and has attained 25 m.p.h. on third gear.
The frame is straight in the horizontal plane, except for a jump of approximately 7 ins, over the rear axle and a further drop of 2 ins, behind for a low platform. It is inswept slightly towards the front, and at this point the side members have widened webs. The frame width at the widest point is 3 ft. G ins. There is a three:point-suspended sub-frame, for which universal trunnion joints are employed, these being of a special spherical type, which also allow telescopic action, and with which we have dealt in detail in our previous article. The frame is strengthened by channel-steel crossmembers, thoroughly well gusseted, and the penultimate cross-member is strutted across the corners.
Welded and riveted outriggers are mounted on the side members of the frame to form supports for the body.
Four cylinders east en bloc and 100 mm. by 140 mm. bore and stroke respectively are employed for the power unit, which develops 50 blip. at 1,800 r.p.m. The exhaust manifold is so arranged that the exhaust is brought forward. All valves are at the near side, and there is a Lucas dynamo bolted to an upper casting forming part of the dynamo ease, the Simms-coupled magneto being carried below this.
There is a link-belt drive to the fan, which is mounted on an 'eecentric, and a second belt drive to a water impeller. Forced feed is employed for the lubricating oil, which is passed through two filters. Unit construction is retained for the engine, clutch and gearbox, the clutch being of the multiple-disc type making use of woven asbestos fabric and unlubricated, except for the spigot bearing.
The gearbox is most compact ; it affords four speeds and has the unusual, but desirable, feature of a reverse pinion which is ideal when not required.
There are four Hardy flexible joints on the three-piece propeller shaft, the construction of which is both ingenious and unusual. The length of the front portion is 3 ft., that of the centre 1 ft. 6 ins., and of the third piece 4 ft. 2k ins. No telescope joint is provided, as the design is such that all four of the flexible joints share any endwise movement caused by the rise and fall of the rear axle.
The centre portion forms the most unusual part of the design. There is a housing, carried by a cross-member, holding two Timken taper roller bearings‘ mounted on a steel sleeve, provided with screw adjustment for the bearings. The centre portion of the propeller shaft is permitted to slide in this sleeve and is grooved for lubricant ; but, to prevent rotational movement between shaft and sleeve, a driving peg is secured to the shaft, and this runs in a longitudinal slot in the sleeve. The whole device runs in an oil bath and is felt-washered at the ends. To adjust the bearings it is merely necessary to slip back the rear cap and to use a spanner, without taking the joint right down.
The axle is of the reversed-pot type; it is a Kirkstall with
David Brown Worm gearing, the differential and diameter driving shafts being made of 100-ton nickel-chrome steel. The axle, which is fully floating, affords St ins. ground clearance, gives a ratio of 6 to 1, and has Timken bedings for the road wheels.
Brakes are provided on all four wheels, the hand brake working in 18-in.-diameter drums, 2 ins. wide; on the rear wheels, the shoes being of the internal-expanding type. ,The front-wheel brakes are interconnected with one set of rearbrake shoes, the tatter acting on drums independent of those for the hand brake. Front drums 15 ins, diameter and 2 ins, wide, are fitted, the shoes being faced with Feredo _ and completely enclosed. The horizontal operating rods have universal joints on their outer ends and are supported at their inner ends by pillars on the axle. Locking over the wheels during steering makes no difference to the brake action.
The system of springing is most advanced. The rear springs are underslung and have a length of 5 ft. between centres, each spring having ten leaves, 21 ins, wide; they are of Woodhead make and include the Woodhead solid forged eyes and spring-clip retainers, but the chief point of interest is that each top leaf is divided, the inner ends being formed as eyes, which are pivoted in stout brackets, forming • the means by which the springs are secured to the axle. This obviates any possibility of the axles moving along their springs, because the driving and braking stresses are definitely taken by the inner eyes. The front springs have a length of 4 ft. and a width of 2t ins„ and they are offset on the axle to prevent dancing.
No holes whatever are drilled in the spring leaves, the clamping bolts for the axles being outside the leaves, whilst two smaller bolts hold the leaves together. All the springs are practically fiat under full load; in addition, the top leaves are of a different camber to the others and act as rebound snubbers.
Cam and lever steering gear having a variable action which gives a quick lock over, but extremely easy steering for small angles, is employed. The steering pivots are in , dined, the front wheels also being canted so that they are within n ins, of self-centring, thus preventing wheel wobble.
The front axle is of ordinary I-beam section at the centre, but the webs are thickened up to the axle pivots, the flanges remaining the same. This gives the equivalent of the round end for torsional strength, whilst ,providing extra strength for vertical and horizontal stresses.
In connectien with the brakes extra-large compensators arc employed, and the cross-shafts have spherical bearings, these being wick lubricated from oil baths. There are three compensations, the front and rear brakes being compensated separately, whilst the third is between them. A slightly stronger braking effect is given by the brakes at the rear, this effect" being proportional to the size of the drums.
When we examined the body this was not quite complete, but there was sufficient to show that it would be most striking. It has a V-shaped front, sloping backwards and with 1)-shaped windows, the whole merging in an artistic manner into the tapered bonnet. There is a door at each side-at the front, and the driver is isolated by a low partition. Eighteen passengers face forward on the double scats, five are situated at the back, two over the near-side wheel arch facing to the centre, and one only being carried over the off-side arch. The seats are staggered so that a 1-ft. 2f-in. gangway gives an effective width between the seat hacks of 1 ft. 5 ins. The one-step entry at -the rear has a height of 1 ft. loaded. There are drop-down ventilators, fixed windows, and a domed roof giving a clearance of 6 ft. 2 ins.
An interesting feature of the design is that the driver has been brought forward 7 ins, by providing a cowl in the dash, which allows more space for the feet of the driver. This cowl projects into the bonneted portion.
The design of body and chassis shows a uniformity which is often lacking, and the chassis and body seem to blend together in a most satisfactory manner to form the complete vehicle.