Pallet fixing lock, determination of shear resistance and spring stiffness

Abstract

The paper contains the designs of modifications of testing devices, which were constructed for the purpose of checking the functional properties of the mechanical pallet fixing lock built by the KOMA - Industry s.r.o. company, which is used for securing pallets with cars in parking houses. The individual testing devices consist of one or two positioning devices, the moveable parts of which are placed perpendicular to each other in the frame of the testing device. A mechanical pallet fixing lock is attached to the moving part of the perpendicular positioning device, and it consists of the following three parts: the body, the pulley holder and a compression coil spring. A plate is attached to the moveable part of the horizontal positioning device and is adapted to receive a pressure force sensor or to engage a mechanical fixation lock or the break of an electromagnetic locking device. The paper contains the description and method of experimentally determined resistance, which is created by the shear friction on contact surface, when inserting or withdrawing the pulley holder tube from the plain bushing of the fixation lock body. Additionally, the paper provides the values of the measured vertical forces, which are generated by the deformed compression spring with a wire of circular cross-section during inserting/withdrawing of the pulley holder tube into/from the fixation lock body. The values obtained from the performed experimental measuring of vertical forces and frictional resistance during the inserting of the pulley holder tube into the plain bushing of the fixation lock body will be used for subsequent checking of the functional properties of pallet fixation locks and will allow determining the optimal position for attaching the pallet fixation locks to stack cell steel beams in the parking house, on which chain conveyers push pallets with cars are parked.