General construction:
The crane structury consists of the chassis, vertical column, derrick (inner and outer boom) and the hydraulic cylinder assembly. All models above one ton capacity have a double column box frame made of steel pipes. The box frame can take heavy loads its wide bearing on the chassis effectively avoids twisting and damage to the crane under rough and unskilled handling. The advantage of this structure is that it diverts the resultant force to the centre of the chassis thereby greatly reducing the possibility of imbalance about the longitudinal centre of the chassis. The derrick consisting of the inner and outer boom is suitably reinforced by the low structure, welded on to the outer boom for better distribution of forces. The inner boom has six locking points, and telescopes into the outer boom. it is fitted with a 360, rotating, forged steel hook. The wide bearing of the derrick, on the double column frame reduces the effect of to-risional forces within the frame.

The chassis is fitted on four wheels. Two wheels are fitted on rigid castors and two are either fitted on swivel castors or into a steering assembly. Cast iron wheels are provided as standard. However rubber tread wheels, may be fitted on reauest.

The steering assembly has a combination of heavy duty thrust bearing and toper roller bearings. The rigid castors wheels are fitted with wheel locks to prevent movement when transfer of load takes plase.

The chassis is a rugged all steel electrically welded structure. It is this member which differentiates one model from another. Two types of constructions are offered, i.e. ('U' frame type and 'G' frame type.)

'U' Frame:
Here the chassis is 'U' shaped, and the job to be lifted is accomodated within the frame itself. The equipment is useful for loading and unloading jobs into trucks and other areas, where the legs can easily slide under obstructions. The advantage of this equipment is that, being shorter in length it has a small turning rodius and no counterweights are required for balancing moments.

'G' Frame:
This is by for the most versatile model. The chassis is 'T' shaped in construction and has a counterweight tank at the rear end into which some counterweight has to be added to balance moments. It offers a larget clear spase for lifting, ahead of the wheels and can be used effectively in areas inaccessible ti the 'U' Frame type, and is preferred for lifting of larger, awkward and unsymmetrical loads,

In models over one ton capacity two column positions are offered as standard. When a shorter reach is required, the column and the derrick assembly can be shifted to position II within minutes, by removing the bolts at the bottom of the column, and the pin at the base of the cylinder. However eventat this position more clear space is available ahead of the wheels than in the U frame models. It is preferred that the crane should be used with the column in position II since a lesser counterweight is required and also the tuming radius of the equipment with reference to the suspended load becomes smaller.

The one ton capacity counterweight type model (i.e. 1000G) is however an exception to other 'G' Frame models here the frame is rectangular in shape, and is extremrly compact. It has a fixed type column which cannot be shitted the overall size of the equipment and the large clear space available for lifting ahead of the wheels, makes it extremely versatile, and easily manoeuredble in tight corners and narrow aisles. This equipment is most favoured, and is our largest selling model.

Hydraulic System:
The hydraulic system consists of the oil tank, manifold plate and hydraulic cylinder. The oil tank and hydraulic cylinder are both welded on the manifold plate which is fitted with the plunger cylinder, release valve, suction cum pressure cartridge insert with a built in filter and a relief valve forming a compact and integral unit. The hydraulic pump is a positive displacement five speed variable displacement pump. The heart of this pump is the cartridge inset which is extremely reliable.

However, if the need ever arises, it can be replaced within seconds even by an untrained person.

The delivery port of the pump is connected directly to the hydraulic cylinder, through a duct in the manifold plate thus making no use of hose pipes and effectively reducing the chances of damage due to a cut or brust hose. The manifild plate has a built in presure relief valve which automatically, diverts flow of oil, from the pump to the tank, in case the equipment is overloaded and the system pressure exceeds the preset maximum level. The hard chrome plating on the hydraulic ram protects it from corrosion and rust.

Operation:
The operation of the equipment is simple. The derrick and hook assembly is lifted by the hydraulic cylinder which is actuated by working the ram pump handle in an up-down pumping action. The lifting speed and lifting effort is varied by selecting any of the five leverages available on the pump handle. As the leverage is increased, the strock, the speed and the effort is reduced for higher speeds, the leverage of the handle has to be decreased by shifting the lever pin, away from the fixed end, thus providing five lifting speeds, with varying effort to suit different applications. Lowering is done by tyrning the release knob in the anti-clockeise direction and can be adjusted to very fine limits to ensure exact positioning of the load.