Abstract: A pass-through transmission for a towing vehicle such as a small tractor or the like is adapted to provide a torque-transmitting connection of a power take-off unit of the towing vehicle to a front-mounting implement such as a sweeper brush. The transmission can be temporarily fixed to the underside of the towing vehicle by latching engagement without involving the use of a tool for fixing purposes so that the transmission can be quickly and easily fitted to and removed from the towing vehicle.

Abstract: The optical switching device includes an optical layer (5) provided with at least one optical waveguide (11) having an entrance (13) and an outlet (15) and at least one other optical waveguide (21) provided in the optical layer (5) with another outlet (23); a piezoelectric layer (7) arranged on the optical layer (5); electrodes (9) for producing an acoustic wave provided on the piezoelectric layer (7); and a device for performing a Bragg light deflection with optical frequency shift by one of activating and deactivating the electrodes to optically couple the entrance (13) of the at least one optical waveguide (11) with one or the other of the outlets (15, 23). The invention also relates to an optical by-pass circuit which is a combination of two optical switching devices.