The presses on which these crank cases are drawn are especially worthy
of note, for they weigh about fifty tons each, and exert a downward
pressure of about 900 tons. It is necessary that this drawing be made in
four operations; the first and second are particularly interesting, on
account of their depths, which are 5-1/2 and 9-3/16 inches,
respectively. After each drawing operation it has been found necessary
that the case be annealed, to restore the strained or calloused surface
produced at certain points by contact with the dies, to a soft, ductile
condition, to conform to the balance of the case, or, in other words,
to produce a homogeneous condition of the surface.
This annealing is accomplished by a furnace through which the cases are
moved by a chain conveyor onto an elevator which raises them up through
the roof, and down again, depositing them near the press which is to
perform the next drawing operation. While moving on this elevator the
cases are cooled so that they can be handled as soon as they are
lowered.
After the drawing operations have been completed, the case is trimmed;
the side arms, front end supports, radius rod support, are riveted and
brazed to it, making a case as strong and solid, and yet as light, as it
is possible to make.
[Illustration: ASSEMBLING INDUSTRIAL MOTION PICTURE FILMS]
Near these crank case presses are located several hundred punch and
drawing presses of various sizes. These presses blank out and draw from
sheet steel of special analysis, a large number of parts (which in
ordinary practice are made from castings or forgings), carrying the same
strength, but also very much lighter in weight.
The interesting feature of this department is the arrangement of the
presses, which enables all finished parts, as well as the scrap steel,
to be deposited upon a traveling belt conveyor, at the end of which are
stationed men who sort the various parts, and place them in proper
receptacles. By this arrangement it is possible to place the presses
closer together than could be done if it were necessary to leave aisles
large enough for trucking the material to and from the presses,
effecting a great saving in floor space.
[Illustration: A THOUSAND ASSEMBLED CHASSIS