The gang mill is regarded as possessing material advantages in the rapid
and economical manufacture of lumber. Among the recent improvements
tending to perfect such mills, those which are shown in the iron frame
stock gang, manufactured by Wickes Bros., East Saginaw, Mich., are
eminently valuable. Our large engraving represents one of these mills,
constructed to be driven by belt, friction, or direct engine, as may be
desired. The important requisite in this class of mills is such design
and proportion of parts as will insure durability and continued movement
at the highest speed, safely increasing the quantity and improving the
quality of work done at a lesser feed, and admitting the use of thinner
saws than is practical in the slower moving sash. These are among the
advantages gained in the iron frame machine, overcoming the necessity
of an expensive mill frame, saving time and expense in setting up, and
avoiding the liability of decay or change of position.
[Illustration: IMPROVED IRON FRAME GANG SAW MILL.]
Many improvements have been made in the mechanism of oscillation, and
from these the builders of this mill have adopted what is known as the
Wilkin movement, which oscillates the top and bottom slides. The top
slides are pivoted at the top end, and the bottom ones from the bottom
end, both being operated by one rock shaft from the center. This
movement when properly adjusted gives an easy clearance and the easiest
cut yet obtained. It adds no extra weight to the sash, and avoids the
cumbrous rock shaft and its attendant joints, usually weighing from
three hundred to five hundred pounds, which have been found so
objectionable in many other movements. The feed is continuous, and is
made variable from ¼ to 1¼ inch to each stroke, controllable by the
sawyer. Power is applied to the press rolls in the double screw form
with pivot point, also operated by the same hand. A special feature of
this machine is the spreading of the lower frame so that its base rests
upon an independent portion of the foundation from the main pillow block
or crank shaft. The solidity of the whole structure is thus increased,
both by the increased width at the base and the prevention of connecting
vibrations, which necessarily communicate when resting upon the same
part, as in other forms of such machines heretofore in use.
The mill shown in the perspective view is one of twenty-six saws 4½ feet
long, sash 38 inches wide in the clear, and stroke 20 inches, capable
of making 230 strokes per minute. The crank shaft is nine inches in
diameter, of the best forged iron. The main pillow block has a base
6½ feet long by 21 inches bearing, weighing 2,800 pounds. The cap
is secured by two forged bolts 3½ inches in diameter, and by this
arrangement no unequal strain upon the cap is possible. A disk crank is
used with suitable counterbalance, expressly adapted to the weight and
speed of sash; a hammered steel wrist pin five inches in diameter, and a
forged pitman of the most approved pattern, with best composition boxes.
The iron drive pulley is 4 to 4½ feet in diameter and 24 inches face;
the fly-wheel six feet in diameter, and weighing 4,700 pounds, turned
off at rim. When a wider and heavier sash is required, a proportionate
increase is made in all these parts.
In the construction of the sash the stiles are made of steel; the lower
girt and upper heads are made in one solid piece, without rivets, giving
the greatest strength possible, with the least weight. The outfit also
includes eight iron rollers for the floor, 8½ inches in diameter, with
iron stands, and geared as live rolls when desired, a full set of
Lippencott's steel saw hangings, and gauges for one-inch lumber. The
weight of the machine here shown is 18½ tons. They are, however, built
in larger or smaller sizes, adapted to any locality, quality or quantity
of work desired.
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It is said that the St. Gothard Tunnel is diverting the bulk of the
Italian trade into the hands of the Belgians, Germans, and Hollanders
with startling rapidity. Without breaking bulk, early fruits are taken
from all parts of Italy to Ostend, Antwerp, and Rotterdam, whence they
are carried by fast steamers to London and other English ports. But, on
the other hand, Germany is sending into Italy large quantities of coal,
iron, machinery, copper, and other articles of which the latter received
nothing before. In two months alone, the Italians imported 1,446 tons of
paper.
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