Disclosed is a subfloor towline conveyor system including a tow cart therefor having an improved tow pin actuating, controlling and locking mechanism. The mechanism includes a linkage system for controlling the movement of the tow pin to obtain power assisted engagement and disengagement with the towline conveyor, as well as improved means for positively locking the tow pin in a driven position and for manually locking the tow pin out of an operative position. There is also disclosed improved accumulating bumper means providing automatic accumulation of a plurality of such tow carts and also serving as a personnel safety bumper.
4297950 - Tow truck - Owned by Nutting Truck and Caster Company (Faribault, MN)
A tow truck of the type having wheels supporting it for movement along a path defined by a subfloor conveyor. There is a vertically movable tow pin at the front of the truck for vertical movement in and out of driving engagement with the conveyor. An accumulation bumper at the front of the truck is movable between a forward normal running position and a rearwardly retracted accumulating position when the bumper engages an object ahead of the truck. A connecting mechanism between the bumper and tow pin includes at least one bell crank member pivoted for rotation on a transverse axis behind the tow pin with a first lever arm projecting upwardly and connected by a link to the bumper, together with a second lever arm projecting forwardly and connected to a vertical lift rod, the upper end of which is operatively connected to the upper portion of the tow pin.
A tow line vehicle having a tow pin is provided with a bumper capable of moving the tow pin from an operative position coupled to a tow chain to an inoperative position. The bumper is coupled to the tow pin in a manner so that it does not interfere with the ability of simultaneously raising the tow pin and a selector pin by means of a handle on the vehicle.
A tow cart is provided with an arrangement in which the tow or drive pin is adapted to be moved out of engagement with the conveyor drive, in response to a predetermined degree of obstruction to the tow cart, by a spring-loaded overcenter double toggle movable from a cocked to a released position in response to the obstruction, and in which the drive pin is pivotally supported so that it may swing forwardly away from the conveyor drive upon the release. In the cocked position of the toggle mechanism the mechanism restrains the forward pivotal movement of the drive pin.
A load carrying unit including a vertically movable pin for engagement with a movable chain of a chain conveyor includes a vertically movable chain engaging pin assembly attached to a front end of a frame structure of the load carrying unit, wherein the vertically moving chain engaging pin assembly includes a cam follower and is vertically movable in response to the position of the cam follower. The cam follower is in cooperating relation with a cam which is provided with a cam surface which follows the contour of a chain guide assembly which includes the movable chain therein.
