Application: Mobile elevating working platform

System interface:  Integrated amplifier with analogue interface

Target:

The main location for force measurement in man-carrying platform, is to monitor the permissible maximum load.

Previous solutions:

Current solutions monitor the permissible maximum load with mechanical limit switches in a spring system. This has several disadvantages, first it is a complex and heavy construction, further there is certain backlash which is needed for the limit switch. Moreover these limit switch is a risk for the designer and the manufacturer in case of an accidents. Because the overload protection can be bypassed very easily by the building workers.

For platforms without overload protection, either the working height is limited, or the construction is carried out massively to intercept the maximum load case.

Requirements of the customer:

  1. optimum use of construction
  2. Avoiding backlash
  3. Avoid tiding over the safeguard
  4. Two-stage warning system (1st warning, 2nd trip)

Alternative solution by use of loadpin:

The assembled loadpins are so interconnected at the amplifier, that the weight can be measured without moments. At the amplifier are two thresholds which turn each one relay contact, the first a warning, the second for overload and to shutdown the machine.

Alternative loadpins: