A vending machine includes a dispensing head, stationary shelf, and integrated mechanism. By turning an actuation mechanism handle the dispensing head rotates through a dispensing cycle delivering a lowermost container of one of a plurality of container stacks of a rotatable carousel off the dispensing head to a temporary position on the shelf below a dispensing opening of a hopper and therefrom to a discharge location accessible at the machine exterior. The integrated mechanism is disposed on a top cover, coupled both to an assembly rod and the carousel, and operable through an oscillatory rotational motion to tighten or loosen a clamping force applied to both secure the top cover on an open top of an outer enclosure while enabling rotation of the carousel to place a selected one of the container stacks at a dispensing position overlying the dispensing opening of the hopper and the dispensing head.