The operator knows by touch when the plunger has pressed the glass far enough to exactly fill the mould.
It is attached to a brass disk E, which is fastened to the centre of the diaphragm F by means of a rivet, and is capable of moving to and fro like a plunger when the diaphragm vibrates.
In pressed glass the exterior surface is modelled by the mould, whilst the interior surface is modelled by the plunger (fig.
A plunger is forced upwards into the glass in the neck-mould and forms the neck.
Attached to the rod by offsets are one or more plunger or bucket pumps, set at intervals in the shaft.
By means of suitable and simple mechanism this vertical movement of the cylinders works plunger pistons in a pair of cylinders which contain glycerin, and these deaden the vibrations of the machinery while weighing is going on.
Compressed air admitted through the plunger forces the molten glass to take the form of the bottle mould and completes the bottle.
In order to deaden the vibrations of the index arm when weighing goods a vertical rod is attached to the lever from the lever machine near its left-hand end, and this rod carries on its lower end a plunger which works in a closed cylindrical dash-pot containing oil or glycerin.
An arrangement of this kind for shifting the load from a large cage at one operation was introduced by Fowler at Hucknall, in Leicestershire, where the trains are received into a framework with a number of platforms corresponding to those of the cage, carried on the head of a plunger movable by hydraulic pressure in a vertical cylinder.