Figure 13-24.—Bar folder.
BAR FOLDER.—The bar folder, shown in
figure 13-24, is designed for use in making bends or
folds along edges of sheets of metal. This machine is
best suited for folding small hems, flanges, seams,
and edges to be wired.
Most bar folders have a
capacity for metal up to 22 gauge in thickness and
42 inches in length. Before using the bar folder, you
must make several adjustments, including
adjustments for thickness of material, width of fold,
sharpness of fold, and angle of fold.
BOX AND PAN BRAKE.—The box and pan
brake (fig. 13-25) is often called the “finger brake”
because it does not have a solid upper jaw as does the
cornice brake. Instead, it is equipped with a series of
steel fingers of varying widths. The finger brake can
be used to do everything that the cornice brake can do
and several things that the cornice brake cannot do.
The finger brake is used to form boxes, pans, and
other similarly shaped objects. If these shapes were
formed on a cornice brake, you would have to
straighten part of the bend on one side of the box in
order to make the last bend. With a finger brake, you
simply remove the fingers that are in the way and use
only the fingers required to make the bend.
The fingers are secured to the upper
thumbscrews, as shown in figure 13-26.
fingers that are not removed for an operation
leaf by
All the
must be
securely seated and firmly tightened before the brake
is used.
To keep brakes in good condition, you should
keep the working parts well oiled and be sure the jaws
are free of rust and dirt. When you operate brakes, be
careful to avoid doing anything that would spring the
parts, force them out of alignment, or otherwise
damage them. Never use brakes for bending metal
that is beyond the machine’s capacity with respect to
thickness, shape, or type. Never try to bend rod, wire,
strap iron, or spring steel sheets in a brake. If it is
necessary to hammer the work, take it out of the brake
first.
Figure 13-25.—Box and pan brake being used to form box.
13-16
