The whole suspended access equipment is consisted of the suspension mechanism, suspension platform, hoist, safety lock, working wire rope, safety wire rope, electric control box and electric control system and etc.
Structural diagram of the suspended access equipment
In order to transport and handle easily, the suspended access equipment will be delivered in a form of unassembled parts from the factory, and then will be assembled only when all components arrive in the construction site.
The suspension platform is a suspended closed frame device with the safety guards around, designed to carry the operating staff, tools and materials for work at heights.
The suspension platform is of steel or aluminium structure.
The suspension platform is consisted of three basic segments and two erection frames for hoists at both ends. Where each segment is consisted of the balustrade at the front and rear, as well as the base. The front balustrade (closing to the working surface) is 0.9m high, the rear balustrade 1.2m high. The multiple basic segments and the erection frame for hoists at both ends form a closed frame platform. The basic length is 1m, 2m and 2.5m; the finished available length is 1m, 2.5m, 3m, 3.5m, 4m, 4.5m, 5m and so on. ZLP800 type platform not more than 7.5m.
The suspension mechanism is a device designed on the top of building to suspend the suspension platform by steel wire ropes. The suspension mechanism is consisted of two suspension brackets with same structure, assembled in pairs.
The suspension bracket ZLP800 type suspended access equipment is consisted of the front base, rear base, tommy bar, upper column, front beam, middle beam, rear beam, reinforced wire rope and counter weight. Where the middle beam is installed in the front and rear beam; the distance between the front and rear base can be adjusted by changing the position of installation hole of connecting bolt, with an adjusting range 2~4m, adjusting space 0.2m. The front and rear beam is installed on the front and rear base through the tommy bar; the distance from the beam to the ground can be adjusted by changing the position of installation hole of connecting bolt between the tommy bar, front and rear base, with an adjusting 8 range 1.3~1.8m, adjusting space 0.1m, it is an adjustable suspension bracket.
The groupware of the reinforced wire rope is connected with both ends of the front and rear beam through the turnbuckle, coupling sleeve and the upper column. The whole rigidity of the suspension bracket can be improved by tightening the wire rope through the turnbuckle.
The suspended access equipment is provided two LTD8.0 hoists with power of 1.8kw (ZLP800 type), which are installed in the erection frames of hoists at both ends of the suspension platform. The hoist is the power facility to drive the suspension platform to move up and down.
The lift motor is the 3-phase asynchronous motor with the electromagnetic brake, where the normal close type DC electromagnetic brake is installed on the upper end 9 of the main shaft of the motor. When power supply is switched on, the armature iron releases from the friction plate under the action of electromagnetic force, which will guarantee the motor to run normally; when power supply is switched off, the armature iron keeps closed with the friction plate under the action of spring force, which will brake the motor immediately; the use of the self-lock of motor can prevent the suspension platform from falling down caused by overload. The electromagnetic brake has a semi-circular release device, the descending handle is inserted into the release device through the kidney-shape handle hole at the upper of the cover of motor; when lifting the handle upwardly, it can open the brake manually. The suspension platform can realize its manual fall under the force of self-gravity. At the joint of the shaft end of motor and the input end of the reducing mechanism inside the box, the centrifugal reducing mechanism is installed, which is used to prevent the suspension platform from falling down sharply caused by stall speed when it makes free fall.
The reducing mechanism inside the box is consisted of the worm wheel, worm gear and 2-class sub-speed reducing transmission system of internal gears. The working wire rope shall encircle the dovetail groove at the outer end of the inner gear disc in “α” form after entering into the body (See Figure 2). When the motor drives the inner gear disc to turn with different directions, under the action of the friction force formed between the wire rope and dovetail groove, the hoist and suspension platform will move up and down along the wire rope.
The suspended access equipment is provided two LSG20 safety locks, installed respectively in the bracket at the upper of the erection frame for the hoists at both ends of the suspension platform.
LSG20(LSG30) safety lock is the skew-free safety lock; it is actually the device to prevent the 10-suspension platform from falling down by locking the safety wire rope automatically when the suspension platform tilts caused by the broken working wire rope or fall of one end of the suspension platform.
The safety lock is only to clamp the rope automatically by the swing arm and rope locking mechanism; it is a kind of the normal close lock
When it works normally, the scroll wheel on the swing arm will lift the swing arm under the force of the working wire rope, which will then cause the rope-locking mechanism to unfasten, and make the safety lock under an unlocked condition. At this time, the safety wire rope can access into the safety lock easily. When the working wire rope breaks or the suspension platform tilts (at certain angle), the pressure at the scroll wheel on the swing arm caused by the working wire rope will disappear, which will make the swing arm fall to the original locking position, and cause the rope-locking mechanism to clutch and clamp the safety wire rope completely, and thus the safety lock will realize the automatic lock on rope.
Schematic diagram of angle adjustment for locking rope
Working wire rope and safety wire rope
The working wire rope will be used to suspend and lift the suspension platform after entering and encircling the hoists; it is actually the carrier of the suspension platform for movement. The safety wire rope will only play a role to prevent the suspension platform from falling or tilting by being clamped by the safety lock when the working wire rope breaks or the suspended access equipment becomes tilted, which will then guarantee the operating staff in safe.
The working wire rope and safety wire rope are the main components to support the load of the suspended access equipment, therefore, the wire rope that will be used must meet the given requirement. Preferably, the working wire rope and the safety wire rope should be the zinc-plated one (it must be, Φ9.1-4×31Fi+PP for ZLP800 type) with features of high strength and rust-proof capability.
In order to prevent the rope damp from loosening and enter into the hoists and safety lock easily, after the wanted length for the wire rope is cut, it’s both ends must be treated specially; whereas the input end shall be polished into a warhead-like shape after being welded.
The power cable is connected between the power supply and electrical box; it is actually the conductor to transmit the electric energy to the suspension platform. The power cable is the 3*1.5+2*1 or 3*2.5+2*1.5 cables with 5-core and rubber sheath, where 3 cables with 2.5mm2 core wires are used to connect with 380V 3-phase power supply, Other Voltage need to be customized.2 cables with 1.5mm2 core wires are used to connect with the zero line and earthing cable.