Pneumatic-tyred Six-wheeled
Page 46
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Trailer for 12-ton Loads
The Latest Dyson Product Embodies a Number of Interesting Features and is Intended for Transporting Cable Drums and Transformers
THAT well-known trailer-making concern, R. A. Dyson and Co., Ltd., 76-80, Grafton Street, Liverpool, which has built many unusual types of trailer for special purposes, has recently constructed an interesting six-wheeled unit on pneumatic tyres for dealing with any type of cable drum or transformer. In spite of the massive loads it is intended to carry, the trailer has a compact and well-proportioned appearance, and although the Dunlop tyres are of 38-in. by 9-in, dimensions, the platform level is only about 2 ft. 7 ins, when laden.
The overall length of the trailer is 22 ft, and its overall width 7 ft. 6 ins. The winch platform is 6 ft_ long and 7 ft. wide, the loading space available measuring 15 ft. 6 ins. by 7 ft. 6 ins.; the distance between the guards of the bogie wheels is 5 ft. 6 ins. The load capacity of the trailer is 12 tons.
Having given a few of the outstanding dimensions we can now turn to the
detail design. The chassis is of the cranked pattern and is constructed from 6-in. by 3-in. rolled-steel channel, the frame carrying the winch equipment and the main frame being connected by steel cheek plates. The winch platform is constructed of oak and has side rails bound with mild-steel wearing strips, whilst the main platform has its 14-in. oak planks laid crosswise, the edges being protected by angle-iron plates.
The bogie is of the compensated spring type, and apart from its simplicity of construction is built to withstand ardu B28 ous service. The springs are of good depth and, in the case of the bogie, are underslung. The four wheels of the bogie are equipped with Dyson doubleacting, internal-expanding self-energizing brakes, and are claimed to be capable of holding a fully loaded tractor and trailer on any main-road gradient. They are operated by two connected cross shafts which are mounted in selfaligning brackets. A hand wheel is mounted at the front on the near side for operating the brakes, provision also being made to achieve the same object from the tractor by means of a wire cable passing through a flexible steel tube at the front.
The guards fitted over the bogie wheels are built up from steel plate and angle iron, suitably supported at the centre. They are constructed to stand up to rough usage, such as men walking on them, and planks, bars, etc., being dropped on them.
A heavy double-purchase crab winch is strongly mounted on the front platform, and it has a safety pawl and a screw-operated band brake. This winch is capable of dealing with 6 tons direct from the barrel, or when used with a single snatch block (this, when not required, is carried in a holder on the winch platform) with loads of 12 tons. The equipment includes 50 ft. of steel wire rope.
Three ramps are provided for use at the rear of the trailer. They are built of oak planks and rolled-steel section, and have claws at the top ends and steel shoes at the other. The claws engage in projections on the rear member of the chassis, an arrangement which enables the ramps to be brought close together or to be spaced apart, thus making it possible to deal with different types of cable drum and transformer.
To prevent damage to the rear springs when loading heavy machinery, two permanent steadying jacks are employed at the rear. When not in use they are held in position by a heavy spring-loaded pin. Two tommy-bars are supplied for actuating the jacks, these being carried in holders secured to the sides of the winch. A spare wheel and
• tyre is carried in a cradle on the near side, below the main frame.
Particular attention is directed to the apparently small clearance between the cranked portion of the trailer and the front wheels, but we are told that the wheels could be turned through an angle of 00 degrees without fouling any part; this object is accomplished by narrowing the spring track and designing the frame clear of all obstructions in the centre.
The trailer, which is equipped throughout with Tecalemit grease-gun nipples, has been supplied to Wordie and Co., of Glasgow.
By reason of the legal speed at which it can be drawn, a trailer of this type has distinct advantages for transporting heavy loads over long distances.