Lifting height, lifting

In certain cases for maintenance work on bridges, the bridge must be raised, for example to replace the supports. Heavy-duty jacks are used for this. The distance at each jack is measured with a string potentiometer so that the jacks operate completely in synchronization.

Catering vehicles play an important role in passenger air traffic. They are responsible for there being enough foodstuffs on board. It is especially difficult with the Airbus A380 to reach the loading hatch with the vehicle. Therefore, the load area of the scissor platform is also maneuverable. String potentiometers are perfectly suitable for measuring this displacement.

Combustion engines are a combination of many different technologies. Therefore, the precision of each individual one is responsible for the performance of the engine. The actual injected amount of fuel for Common Rail engines is controlled by the lift height and the lift duration of the jet needles of the injector. Temperatures up to 150 °C, pressures up to 2000 bar and an electromagnetically sensitive environment make measurement evaluation difficult. The NLS miniature sensor of the eddyNCDT product group measures the needle movement at the tip of the injector where influences due to bending or compression of the needle do not even occur.

Modern mobile cranes are always employed when heavy loads must be lifted quickly and at various locations. They are used, for example, in the recovery of broken down trucks. The field of operation is not restricted to paved surfaces, but also includes deployment in open terrain. Therefore, these cranes possess an adaptive design of running gear in which the suspension of each independent axle can be adapted to the relevant terrain. This is implemented using a suspension cylinder which is fitted with a displacement sensor. The sensor acquires the cylinder stroke and consequently enables the best possible adaptation to the form of the terrain.

For electronic synchronization monitoring, a string potentiometer is used here. These are easy to integrate, very compact and offer high accuracy in addition to the large measuring range. For displacement measurement, the sensor is mounted on the lowest cylinder tube of the telescopic cylinder with the opening facing downwards. This prevents dirt or liquids from getting into the inside of the sensor. The steel cable with wire extension is guided from the sensor via deflection pulleys into the cylinder tube.

The sensor used is a type WDS-1500-P60-CR-P-M4 draw-wire displacement sensor with robust aluminum housing and a type WE-1500-M4 wire extension with M4 wire connection and 1500 mm wire length. In addition to the sensor used here, Micro-Epsilon provides a large number of other suitable string potentiometers for the same or similar applications, such as the MK77/MK60 series with a robust plastic housing.

Short cycle times for the assembly are extremely important in automobile production. In order to design the optimum ergonomics for the worker, the vehicles

are transported along the production line on lift tables. Depending on the work operation to be performed, the vehicles are moved to the optimum height in order to ensure as efficient working as possible. Which exact height has been reached is established using string potentiometers from Micro-Epsilon. Completely integrated in the lift table, they ensure more reliability and higher productivity.

Side supports against tipping over are installed for lift trucks and lift work platforms. The crane or the platform can only be put into operation when the supports are completely extended so that there is also no danger of tipping in the case of long extension frames. However, sometimes this is not possible for spatial reasons. Therefore string potentiometers from Micro-Epsilon are used for measuring how far the supports are extended. A dynamic load torque limit across the actual support area is thus produced. Redundant measurement is performed as this is a safety relevant measured value.

The frequently used automatic rack control units make modern warehousing much easier. These units must automatically travel long distances and position the products with millimetre precision at the end. Modern optical laser sensors and also string potentiometers are used to monitor this movement. String potentiometers are the more economical solution for distances up to 50 metres. Laser sensors which determine the distance using time of flight measurement are suitable for larger distances. Distances can be precisely measured and loads can be exactly positioned or delivered with their help.

Optimum execution of the training plays an important role in the rehabilitation area. Data for monitoring the performance of the individual exercises are provided to the trainer using a network or a chip card. String potentiometers, among other things, are used to enable the provision of this information. The primary factors for the user here are the simple mounting and the long service life.

A large part of internal transportation is performed by forklifts. The risk of tipping the forklift when products are lifted is high. Therefore, the permitted speed has been restricted with limit switches. String potentiometers from Micro-Epsilon measure the current lift height and make continuous speed regulation possible, depending on the height of the products.

Mobile lifting jacks are being used more and more often for commercial and railed vehicles. The lifting jacks for commercial vehicles are often designed as column lifts. In contrast, railed vehicles are often lifted on the frame. Any number of these lifting jacks can be combined into one system. As each lifting jack has its own drive for the lifting movement, the individual devices must be synchronised in order to ensure a completely level and oscillation-free movement. The lifting movement of each lifting jack is measured with a string potentiometer for this.

The distance of both rollers from each other or from the roller to the support surface is the crucial dimension for rolling processes for metals, plastics or other materials. In the case of sensitive processes and high material accuracies, the lift of the upper roller must be checked constantly so that imminent rejection is avoided. The contacting inductive and the non-contact methods are suitable for this. In the case of contacting methods, the sensor is mounted on the outside on the roller guide. The change in clearance is transmitted to a plunger whose position change is measured by the inductive sensor.

In the case of the non-contact method, the roller is between the transmitter and receiver of an optical micrometer at the height of the lift. The emitted light curtain is partially covered by the roller. The remainder reaches the receiver through the gap. The gap can be calculated based on the light quantity measurement.