タイトルまたは説明

In certain applications, the power-operated devices have, due to their inertia, long stopping times and thus also large stopping travels. Examples are big and heavy doors (hangar doors), automatically-guided vehicles (AGV), theatre stages etc.
In these cases, the max. up to **0 mm high safety edges will not be sufficient.
Here so-called bumpers are used. Their dimensions as well as the positions and number of the contact chains are specially selected and manufactured for the intended application.
Bumpers are protection devices for large over-travels. They are equipped with a rubber-foam cushion with suitable surface finish and reinforced if necessary. Colours may also be applied.
Current conducting contact rollers and insulating intermediate elements (wedge rollers) are alternately lined up on an expander cord. By pretension, the contact rollers are pressed together, and the current circuit is made. Actuation of the safety edge leads to at least one pair of the contact rollers to separate by action of the wedge-shaped intermediate elements, and the current circuit is broken. Due to the positive break of the supply, transformation of the output signal is not required, since a circuit interruption signal is directly available. This signal is fed to the safety relay unit already needed for the E-stop . Note: Wiring of the contact chain is performed in an identical way as of an E-stop .
The bumper sensor is built up of mechanically opening N/C contacts connected in series, in the form of a contact chain.
The bumper is built up of a soft polyurethane foam, in the interior of which contact chains are disposed immediately adjacent to the actuating faces. The number and the positions of the contact chains depend on the size and the intended application of the bumper. In case of railbound vehicles or rectilinear machine movements, normally only the front side of the bumper serves as the actuating face. In other cases where vehicles or machines follow curved paths, contact chains will also be mounted at the side faces. The completed foam body with included contact chains is glued to a carrier plate and fully coated with polyurethane material. Standard colours are black and red. Yellow safety stripes can also be applied as an option. The thickness of the coating is determined by the forces and impacts to be expected. Normally the carrier plate is of aluminium. For attachment of the bumper at the vehicle, threaded bolts are provided, the size and number of which will be determined by the size of the bumper. Further, cable terminals for circuit connection are also located in the area of the carrier plate. All dimensions for threaded bolts and cable terminals are usually freely selectable. Customized shapes or colours are possible, and the bumper will be fitted to the individual appearance of the vehicle.