Abstract Scissor platforms are used for vertical transport of loads or persons to keep them at the requested height of the load device. Lifting platforms, both mobile and stationary, are nowadays used almost with no limitation, e.g. in the production, storage, handling (for loads, equipment or people transport). Drive scissor lift platform is an important part of scissor platform. Lifting device is a mechanism that raises scissor construction and the platform to speciÞc height.71212

Keywords Scissor platforms Lifting device Hydraulic piston Telescopic push chain Serapis

1 Introduction

There are many solutions and options the platform can be lifted. Decisions are made according to three main criteria: the lifting height, weight lifting equipment

According to (CSN EN 1494 + A1), page 11, Sec. Drive 3.2 these drives are used:

• ManualÑhuman power drive,

• PneumaticÑcompressed gaseous substances drive,

• HydraulicÑcompressed hydraulic liquid drive,

• ElectricÑelectrical energy drive.

There are described the most commonly used drives of lifting device by using hydraulic piston and a telescopic push chain Serapis.

2 Hydraulic Piston

Most often, it is a hydraulic piston in the Fig. 1 which is used for scissor platforms drive.

Lifting is based on the principle of pressure energy and physical properties of the incompressibility of liquids. The principle is in the circulation of working liquid in the closed circuit and of mineral oil in the tank of hydraulic unit. Pressure of the liquid is ensured by hydroelectric generator. Pipeline, connections and pressure hoses are used for joining the inpidual parts.

In the hydraulic mechanism, there are losses caused by liquid friction, therefore there must be used short hoses and a little amount of knees (Kop‡cÿek and a Pavlok 2009).

The beneÞts are simplicity, large force and accuracy in small dimensions, and a high efÞciency.

Disadvantages of this mechanism are expensive service, maintenance, risk of liquid leakage at the failure, commissioning by a specialized person.

Possibilities of the scissor platforms Ôhydraulic piston locations are in the Fig. 2. Inpidual placement of hydraulic piston has an impact on its size.

3 Electric Drive with Push Serapid

It is a mechanical way of lifting. The principle is based on locking or unlocking the connecting elements. During lifting a load, specially shaped chains join together and formate a solid column. When folding the chains are gradually unlocked and composed in the lower part. Serapid combines the advantages of hydraulic mechanisms which are reliable and safe, and removes restrictions of lift height. It is possible to construct Serapid by achieving higher heights of strokes height while Serapid is on the same hight but at the expense of larger rack type area.

Other beneÞts include lift to the nearest millimeter at high speed, high speed of lift, lift up to 10 tons at high altitudes, easy construction, minimal maintenance.

Solution the Drive Lifting Scissor Platforms 21

Fig. 1 Hydraulic piston by scissor platforms

Fig. 2 Possibilities of the hydraulic piston by scissor platforms

22 M. Buri‡n et al.

Fig. 3 Location by scissor platforms

The disadvantage is that the load must lie at right angles to conduit, the power unit must be horizontally attached to the base. It must be ensured to prevent working of axial force to a Þxed column of linear telescopic push chain. Location of linear telescopic push chain Serapide at the scissor structure is in the Fig. 3 (Serapid 2013).