Abstract: A blood collection bag is suspended from a leaf spring, which leaf spring, on being repositioned a specified distance by the weight of a properly filled blood collection bag, energizes an electrical circuit. The electrical circuit generates a pulse to momentarily energize a coil in proximity to a permanent magnet and momentarily disrupt the magnetic field of the magnet. A clamp for terminating the flow of blood to the blood collection bag is actuated on release of a weight retained by the magnetic field of the magnet, which release is achieved by the disruption of the magnetic field on energization of the coil.

Abstract: A weight actuated dispensing mechanism including a bracket adapted to be attached to a conveyor system and having an inlet opening therein for receiving material from the conveyor system, and an outlet opening for allowing the material to exit from the bracket by gravity. A valving mechanism is pivotally attached along an axis to the bracket for movement between a first position wherein the valve mechanism closes the outlet opening of the bracket and a second position wherein the valve mechanism is open to allow material to pass from the conveyor system, through the bracket, to a container disposed below the bracket. A projection on the valve mechanism is provided for automatically increasing the closing force on the valve mechanism as it closes. One end of a flexible line is attached to the valve mechanism and extends over the projection.