The Hoist In Detail
Please see the images to the right
1. Reduction Gear Epicyclic crown wheel with heat-treated high-strength steel gearing supported by oil-bath lubricated ball bearings. Noise level at full load is less than 85 db. The aluminium casing is finned externally for more effective heat dissipation by radiation.
2. Self-braking electrical motor The axial movement of the tapered brake ensures a fast braking action that remains reliable upon time accrual [RES. 4.1.2.1 c - Machinery Directive]. Brake lining is asbestos-free. The motor is available in two versions: a single polarity version for one-speed hoists, and a pole change version for two-speed hoists.
3. Chain The chain is gauged and made of high-strength steel rod having an ultimate tensile strength of 80 kg/mm2, and ultimate elongation higher than 10%. The applicable safety coefficient is always better than 5 [RES. 4.1.2.4 - Machinery Directive]. The heat and galvanising treatments applied to the chain ensure high resistance to wear, aging and corrosion.
4. Load Sprocket The load sprocket is heat treated, and has five pockets. The pockets are machined by use of recision machinery. The sprocket drives the chain, and ensures optimized chain motion.
5.Chain Guide (inserter/extractor) This component provides for insertion and extraction of the chain links into and from the pockets of the load sprocket, both in ascent and descent. [RES. 4.1.2.6 - Machinery Directive].
6. Load Hook The hook, made of high strength forged steel, is fitted with a safety device [RES. 4.1.2.6 - Machinery Directive], and rotates on a thrust bearing.
7. Single Fall Bottom Block(1 Chain Fall Hoists)
The bottom block is the joining element between the chain and the hook. It is made of steel, and is equipped with a heat-treated large cross-section chain locking pin.
8.Two Falls Hookblock(2 Chain Fall Hoists)
Made of aluminium, completely closed, it is equipped with a high-resistance steel transmission reel, thermally treated, with pockets for the housing of the chain.
9. Chain Stops The stops are fitted on both the ascending and descending sections of the chain. They act as limit switches of hook travel [RES. 4.1.2.6 a - Machinery Directive], and can be set as desired. They are made of forged steel, and are fitted with a shock-absorbing insert.
10. Clutch Device The clutch is an emergency device that replaces the traditional electrical limit switches as chain full up and down stops. It also operates as an overload protection [RES. 4.2.1.4 - Machinery Directive]. The clutch discs are asbestos-free, and are pre-loaded through a set of Belleville washers.
11. Balancer The balancer is connected to the clutch joint, and provides for correct hoist balancing. It absorbs the heat generated during clutch operation.
12. New Brake DMK 2-3-4 The new brake shoe fitted in hoist sizes 2-3 and 4 is manufactured with a fan for more efficient cooling of the brake and motor. The high degree of inclination of the brake surface allows for optimal braking in the most arduous working conditions. Brake movement is simply carried out by the adjustment of the external brake ring.
13. Overload Device(2 Chain Fall Hoists)
Electromechanical, with a microswitch for one intervention threshold [RES. 4.2.1.4 - Enclosure I Machinery Directive ]. The overload device does not permit the hoist to be loaded with an overload exceeding 20% of its maximum capacity, by blocking the control circuit of the lifting control device.
14. Suspension It is produced with an eyebolt suspension; are available on request, the executions with hook suspension or by eyebolt 90° version for longitudinal positioning of the hoist.
Lifting Limit Switches Included in the supply for the 2 chain fall hoists and available, on request, for 1 chain fall hoists, they limit the hook’s ascent and descent run [RES. 4.1.2.6 a) - Enclosure 1 Machinery Directive]. They are made of two precision microswitches which function according to the principle of “slow positive opening” and work on the auxiliary circuit of the control device of the lifting motor.
Chain Box The chain box is available in several sizes as a function of hook travel. It is made of shock-resistant plastics and is fitted with suspensions which ensure freedom of movement.
