Conveyor systems

Claim 1

IN A CONVEYOR SYSTEM COMPRISING IN COMBINATION A PLURALITY OF INDIVIDUAL LOAD CARRYING TROLLEYS, A MAIN TRACK ADAPTED TO SUPPORT SAID TROLLEYS, AND ENDLESS DRIVING CHAIN LOCATED ABOVE SAID MAIN TRACK, PUSHER DOGS DEPENDING FROM SAID CHAIN AT SPACED POINTS THEREALONG TO ENGAGE TROLLEYS PRESENT ON SAID MAIN TRACK AND TO PROPEL THE SAME ALONG THE LATTER, AT LEAST ONE SWITCH DEVICE IN SAID MAIN TRACK AND AN AUXILIARY TRACK COMMUNICATING WITH SAID MAIN TRACK THROUGH SAID SWITCH DEVICE SO THAT SAID TROLLEYS CAN BE DIVERTED FROM SAID AUXILIARY TRACK TO SAID MAIN TRACK, THE PROVISION OF TRANSFER MEANS OPERATIVE ON THE APPROACH TO SAID SWITCH DEVICE OF A VACANT PUSHER DOG ASSOCIATED WITH SAID MAIN TRACK TO POSITIVELY PROPEL A TROLLEY FROM A PRESELECTED POINT ON SAID AUXILIARY TRACK AND ONTO SAID MAIN TRACK FOR ENGAGEMENT AND PROPULSION ON SAID MAIN TRACK BY SAID VACANT PUSHER DOG, SAID TRANSFER MEANS COMPRISING AN ENDLESS DRIVEN TRANSFER CHAIN PROVIDED WITH AT LEAST ONE SET OF A PLURALITY OF INDIVIDUALLY DISPLACEABLE RATCHET TOOTH MEANS OPERATIVE TO BE ENGAGEABLE WITH SAID TROLLEY FOR TRANSFERRING THE TROLLEY BETWEEN SAID PRESELECTED POINT AND SAID AUXILIARY TRACK AND BETWEEN SAID TRANSFER CHAIN AND SAID MAIN TRACK.