A Light Hydraulic Tipping Gear WHILST the Weston hydraulic tipW
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ping gear, manufactured by Sunsaloon Bodies, Ltd., Weston Lane, Birmingham has, for some time, been used as the standard unit on Bedford, Morris-Commercial and Garner vehicles and has recently been adopted as the standard gear for the Dodge 4-tonner, it has not, until a week or two ago, been made available to operators through the usual trade channels.
Following the success of the gear on the vehicles mentioned above, it has, however, been decided to expand the market for the outfit, and the concern has now a sales organization for this purpose.
Of the telescopic type, the Weston gear has been developed to provide a hydraulic tipping gear that is light in weight, simple in design and efficient in operation. At the same time several new and practical features have been incorporated to ensure long life, reliability and ease of control.
From the point of view of weight, the maker claims that the gear, complete with hinge-bar and brackets, weighs under 1/ cwt., a claim which was substantiated when we weighed the component parts for ourselves and found the total to be but 163 lb.
The low weight is largely obtained by securing the pump directly to the chassis gearbox, instead of employing a power take-off with shaft and universal joints to drive a separately mounted pump.
Attached to the gearbox at the power take-off flange, the pump is of the two-plunger type. It is of sturdy construction and has an ample pressure reserve.
An oil reservoir situated in the driver's cab has incorporated in its
design the control valve, which enables the pressure in the system to be relieved until required.
On closing the control valve, oil is diverted to the ram through drawnsteel tubing, and sufficient pressure is generated to raise the body and load when the engine speed is accelerated to about 750 r.p.m.
Incorporated in the oil line is a release valve, set to 2,200 lb, per sq. in.; when the ram is fully extended the rise in the pressure opens the valve, and the excess oil is returned to the tank.
The twin-telescopic-type ram has an ample lift capacity and the pressure cups are of patented design, embodying a brass shroud on the face where the greatest amount of wear takes place. An ingenious locking device is provided on the ram to prevent any• possibility of the body lifting at the front. This consists_ of a springloaded hinged bar mounted on the cross-bearer, and having 'at the top a hook which engages with a flange on the bottom of the ram. A small plunger bears against the rod so that immediately pressure is applied to the ram the plunger operates and disengages the book from the flange, thereby allowing the ram to rise.
Another important feature is the provision of a safeguard against overtipping. With certain classes of load it sometimes happens that the material piles up at the rear of the body and tends to draw the ram out violently, in a manner detrimental to both the chassis and tipping gear. To obviate this, an annular space is provided below the inner-ram head. This space is normally filled with oil and the-ram head is carefully machined to give a clearance of .010 in.
When the overtipping condition arises the load must, to extend the ram farther, withdraw the oil from the annular space, and the small clearance allowed delays the action so that the ram is gently extended to its maximum angle of tip.
The effectiveness of this feature was demonstrated to us, when a load of over three tons was situated behind the hinge-bar. The ram was extended in a markedly smooth manner.
A universal trunnion mounting is used for the ram, and movement up to 7i degrees each side of the vertical is allowed to provide for chassis distortion. A further feature is that a safety valve is incorporated in the base of the ram.
The whole of the gear is well finished and is built on sotind engineering lines. It is designed for use on 3-4-ton chassis, with body lengths up to 10 ft., whilst the load capacity is 5-6 tons. The retail price of the gear, including rear hinge-bar and brackets, is £38 10s.