Abstract: A mold conveyor drive assembly is provided to selectively drive an endless mold conveyor chain with a central unitary driving force exerted along the longitudinal (horizontal) axis of the mold conveyor chain being driven. The mold conveyor drive assembly comprises a vertically oriented endless cat drive chain which is provided with motor drive means. The cat drive chain is positioned below and in spaced-apart register with the mold conveyor chain. The cat drive chain is provided with a plurality of spaced-apart drive dogs along the longitudinal axis thereof which are adapted to be selectively moved into engagement with the mold conveyor chain so as to driveably engage selected of a plurality of corresponding spaced-apart pusher elements provided along the longitudinal axis of the mold conveyor chain and to selectively act upon the mold conveyor chain to decelerate and stop it when desired.