has been conferred upon them in the mold.
The object is to prevent the hubs shrinking away from the rims after the latter have cooled, as is apt to be the case when the cooling is initiated in the reverse order.
Geisse's annealing oven.
Mowry, May 7, 1861.
The car-wheels, alternating with layers of charcoal, are built up into a pile in a pit, which is so arranged that the quantity of air may be graduated to regulate the combustion, which is designed to be protracted.
The double walls of the pit or annealing case form a non-conductor to retain the heat, and allow but a very gradual cooling to the mass.
Mowry's car-wheel annealing.
Moore's car-wheel annealing
Moore's car-wheel annealing.
Moore, December 5, 1865.
The wheels are removed from the molds while hot, are piled one above another in a vertical pit, with intervening rings so placed as to separate the chilled tire from the web which is to be annealed.
The interior space around the hubs is filled with charc
by the screw-conveyors d d.
Fig. 3138, B, is a purifier in which brushes are employed for clearing the meshes of the cloth.
The meal or middlings is fed by rollers a to the bolt b, its amount being regulated by a slide; a shaking motion is imparted to the bolt by an eccentric c on a shaft, and a continuous upward current of air is passed through the machine; fine particles adhering to the bolting-cloth are removed by brushes d attached to endless belts e.
Fig. 3139, C, shows a machine with reciprocating shakers, with knockers for clearing the meshes of the cloth.
In this machine the suspended shaker a is pressed against the ratchet-wheel b by a spring c, the rotation of the wheel causing a vibration of the shaker; d is a rock-shaft, pivoted at c, loosely connected with the shaker by a slot and pin at f, and provided with an arm g carrying a hammer, which strikes the bottom of the shaker at each reciprocation.