Introduction
The standard V-shaped conveyor fingers support the board by a force that is related with the impression of the spring loaded fingers. The total force at the sides of the supported board should be limited to prevent the board from too much bending. On the other hand, the board should be sufficiently fixed so that it keeps his position in the conveyor without sliding.
Points to keep in mind
In fixing the board in the conveyor system we are confronted with the fact those larger boards will have a greater weight and need more gripping force. On the other hand the deformation of these larger boards is more excessive since this bending is related to the board width (See Information sheet 22 - 25).This often requires the use of L-shaped fingers and a board support in the machine and the waves to keep the board well fixed in the fingers and at the same time compensate for the bending of the board.
Note: The side grip force is about 70-gram/mm finger displacement per V shaped finger.
The maximum finger displacement should be limited to 5 mm, giving a maximum side force of 350 gram/finger. It is however advised to reduce the side force to maximum 100 gram/finger. Each finger will have an opposite finger at the other conveyor part, meaning that in case a side pressure of 100 gram per finger is needed, the conveyor legs should be set about 2 × 1.5 mm = 3 mm closer. This is just to illustrate the relation. For most practical settings this load is too high and not necessary. Knowing the amount of supporting fingers and the board weight one can adjust the conveyor to the demanded fixing force. Since the standard V-shaped finger has a supporting angle of 45°, the weight load for a standard finger should, as a rule of thumb, be reduced also to maximum 100 gram/finger. For wider boards this load might cause already too much deformation for the board. In that case L-shaped fingers and/or board support should be used.
Note: Board support is only possible when the board has in or around the middle of the board over its
full length a free "path" for the supporting wire without joints and components.
Although the L-shaped finger can in theory carry a much heavier weight it is recommended to reduce the weight load for an L-shaped finger to 250 gram/finger. The side pressure of the L-shaped finger should be limited to a value that the board is just firmly fixed so that it will not slip in the conveyor.