Device for monitoring the alleyways between shelf units in a warehouse
OwnerOtmar Fahrioninventor
Life of this patent
Estimating the term…
Abstract
The alleyway-monitoring device disclosed has, mounted at different heights, two light barriers (16 to 26, 28 to 30), the higher of which is at a height at which the light beam can be broken only by fork-lift trucks. The light barriers produce output signals which enable the direction of motion of the objects which break the beam to be determined, the output signals being passed to associated up/down counters (50, 52) which are in turn connected to the inputs of a monitoring circuit (54). The monitoring circuit triggers an acoustic alarm (56) if non-permitted counter-reading combinations occur.
Claims10
A monitoring device for an alleyway defined by a pair of upstanding structures, the alleyway having at least one accessible end, comprising:
- at least two light barrier assemblies (16 to 26, 28 to 38) mounted at a first height level and a second height level, respectively, on said pair of upstanding structures at said at least one accessible end, each of said light barrier assemblies supplying an output signal responsive to an object breaking light beams formed by said light barrier assembly, the output signal being based on the particular sequence of breaking of the light beams of said light barrier assembly, the sequence being based on a direction of motion of the object which breaks the light beams;
- an up/down counter (50, 52) for each of said light barrier assemblies, each up/down counter being supplied with the output signals of its associated one of said light barrier assemblies (16 to 26, 28 to 38);
- and a monitoring circuit (54) being connected to output signals of the up/down counters (50, 52), said monitoring circuit (54) supplying an alarm signal whenever said monitoring circuit (54) determines a pre-set combination of readings of said up/down counters (50, 52).
Dependencies are inferred from the claim text.