Arrangement in working lamps

Claim 1

An arrangement in working lamps of the kind comprising an upper pivotable arm, light fittings supported at the outer end of said upper arm, a lower pivotable arm, a housing at the lower end of said lower pivotable arm, a horizontal shaft in said housing, said lower pivotable arm arranged for pivotal movements about said horizontal shaft, a segment interconnecting said pivotable arms, a first and a second pivot shafts arranged on said segment, each one of said pivotable arms hingedly connected to said segment so as to pivot about its respective one of said first and second pivot shafts, the improvement comprising a rail extending essentially in parallel with said lower pivotable arm, a third pivot shaft arranged on said segment, said rail pivotally connected to said segment so as to pivot about said third pivot shaft, a guide means, said rail axially displaceable in said guide means relative to said lower pivotable arm, a pin-and-slot coupling arrangement, said rail cooperating with said housing by means of said pin-and-slot coupling arrangement, said slot serving as a track to guide said pin and extending in a curve, from a maximum radial distance from the lower pivot shaft of said lower pivotable arm to a maximum distance from said shaft, in addition to which said slot serves to take on one of its edges any moments of load exerted by said light fittings in any one of their set positions and transmitted via said upper pivotable arm, said segment and said rail.