Electromechanical lock for a platform or landing door.
The special design of the lock allows the door to be unlocked not only from the outside but also from the inside in an emergency. This is necessary for scissor lift tables or column lifts where people ride along with the load.
Catch-up control system
Normally, poppet valves are used in the hydraulic system, which guarantees that a certain position is maintained for several hours. The use of a catch-up control is recommended if the lift table needs to hold a raised position safely in one position for a longer period of time. If no lowering command is triggered and the scissor lift table still leaves its position, the control system readjusts for a short moment until the desired position is reached again.
Euro plugs or so-called Schuko plugs in daily household use are more well-known than CEE plugs. You come across these two plugs every day, for example when connecting your TV or refrigerator to the power supply. Because they only have two pins, they are only suitable for a two-pole power supply (230 V in Germany). We supply our lift tables ready for connection with a 16 A CEE plug (400 V 3/N/PE 50 Hz) as standard.
A different plug is required if three-phase motors are used in a machine, though. To set up a rotating field, at least three voltages with different phase angles are required, which is why a connector with at least three pins is necessary. For this reason, a CEE plug has a total of five pins. Three pins ensure the necessary voltage supply with the different phases. Another pin serves as a neutral conductor and the fifth pin is used as a protective conductor.
CIP – continuous improvement process
CIP is a quality improvement method derived from the Japanese Kaizen. It is based on the assumption that no process or product is perfect and can therefore be continuously improved. Attempts are made to come closer to the optimum through continuous small improvements. This means that each individual production step is constantly being questioned and examined for optimisation possibilities.
This continuous improvement is contrasted with innovation, i.e. improvement by leaps and bounds. Both types of improvement are of great importance for the long-term success of a company. With CIP, continuous optimisation of the company's own processes and products is achieved, while innovations are intended to secure the long-term success of the company. Simply focusing on small improvements only could have the effect that a radical and major trend is missed (keyword: diskette and CD).
This is a lifting device which uses a column structure instead of a scissor lift mechanism as the lifting system.
A distinction is made between column lifts with direct and indirect drive. With a direct drive, the lifting structure acts directly on the platform to be lifted. With indirect drives, the force is first redirected, for example by a deflection pulley. Hydraulic column lifts usually make use of an indirect drive. A deflection pulley is mounted on the lifting cylinders. Several wire ropes run on this pulley, which on the one side are connected to the platform to be raised and the fixed structure on the other side. The platform is raised when the hydraulic cylinder extends.
A component is an individual element or part of an assembly or a complete technical plant. The term component is often used to describe those individual parts for which no further subdivision makes sense.
From the point of view of a lift table manufacturer, a lift table therefore consists of the following components, for example:
- Base frame
- Hydraulic power unit
- Control system
In the above example, the hydraulic power unit is referred to as a component, as a further subdivision is not practical from the point of view of the lift table manufacturer. From the point of view of a manufacturer of power units, the situation is different, so that the hydraulic unit would be subdivided in more parts:
- Electric motor
- Gear pump
- Valve block
- Pressure relief valve
- Throttle valve
A component fails if the corresponding component no longer fulfils or can no longer fulfil the intended function.
Failure always occurs when the properties of the component do not match the requirement profile of the respective application. Component failure can therefore be caused by wrong design, improper use or undetected defects of a component. Accordingly, the physical, mechanical, electrical, thermal and chemical properties must be taken into account when designing, using and testing the components.
In the case of mechanical components, e.g. the scissors of a lift table, component failure is manifested by a break or by fatigue failure. The cause of the damage can usually be easily determined on the basis of the existing damage pattern and the calculation of the theoretical stress levels within the component. It is important to ensure that it has a sufficiently long service life when a lift platform is designed.
In the case of electrical components, such as the motor contactors of a lift table, component failure is manifested, for example, by the electrical contacts fusing together or a break in the contact spring.
Compression and rebound occurs in a lift table or column lift when loads are applied or removed when they are in a raised position.
The rebound of the scissor lift table or the column lift is due to the pressure difference within the hydraulic circuit before and after loading or unloading. Let’s assume that a scissor lift or column lift is raised empty and has an operating pressure of forty bar. If a load is now applied in the raised position, the operating pressure within the hydraulic circuit increases. The hydraulic oil is compressed more and the platform compresses slightly.
When the load is removed, the opposite effect occurs, i.e. the operating pressure is reduced, the hydraulic oil expands again slightly and the cylinders extend slightly.
In most cases, the compression and rebound of the lift tables or column lifts is not critical and therefore does not have to be prevented. However, if a high stopping accuracy must be maintained, various measures can be taken to completely prevent compression and rebound. Examples include the setting down on maintenance supports, locking bolts or catch-up controls.
Concrete is a mixture of cement, aggregates and water. In addition, reinforcing steel is often incorporated to increase strength.
There are many points of contact with structures made of concrete in lift table construction. Pits or shafts can be mentioned as examples.
The curing time is an important factor to be taken into account when working with concrete. It can be assumed that the concrete will only be strong enough after just under a month.
A distinction is made between the control circuit and the operating or power circuit in the design of an electrical control system. The operating circuit accommodates the consumers, while the control circuit is responsible for the logic of the control system. The components that switch the components of the operating circuit are accommodated here. The control circuit often contains relays, for example, which only have a low power consumption. In contrast, the "consumers", e.g. the electric motor of the hydraulic unit, are accommodated in the operating circuit. This has a much higher power consumption. Consequently, it also has a higher voltage level and larger cable cross-sections.
The control panel designates the place where the main or auxiliary control of the lift table or goods lift is installed.
It is often a requirement that the movement of the lift table can be viewed from the operating position in lift platforms that are not enclosed. This greatly reduces the potential danger during the lifting movement. If there are several control panels, they must often be locked out from each other.
For a qualitative assessment, the number of cycles must be referenced to a defined time span. For a lift table, the number of double strokes per hour is usually specified. This key figure is of great importance for the design of the scissor lift . It can be used, for example, to estimate whether more elaborate lubrication, oil cooling or other equipment features are required.
The cycle time describes the time required for a complete cycle. In the case of a scissor lift table, this is usually a lifting and lowering process.