IMPROVEMENTS IN MACHINES FOR STAMPING, SHEARING, AND PUNCHING METALS AND OTHER MATERIALS
Year: 1878

page_text: PROVISIONAL SPECIFICATION left by Alexander Melville Clark at the Office
of the Commissioners of Patents on the 25th September 1878. A communi-
cation from abroad by David Brickner, of the City, County, and State of New
York, United States of America.
ALEXANDER MELVILLE CLARK, of Chancery Lane, in the County of Middlesex,
Patent Agent. "IMPROVEMENTS IN MACHINES FOR STAMPING, SHEARING, AND
PUNCHING METALS AND OTHER MATERIALS." [A communication from abroad by
David Brickner, of the City, County, and State of New York, United States of
America.]
This Invention consists in the combination of a hand lever with a heavily
weighted pendulum hung on a pivot and moving an eccentric whose rod is
connected with the slide of a punching, shearing, or stamping machine. The
Invention also consists in a novel device for stopping the action of the slide of the
machine while the pendulum is permitted to oscillate. The object of the Invention
is to provide a simple and powerful machine to be operated by hand or by means of
a treadle for punching, shearing, or stamping metals and other materials. According
to this Invention the bed plate of the machine is provided with two ears, one at
each side of an opening in the bed plate, which receives the upper bifurcated end of
the pendulum which is hung upon a pivot pin passing into the ears. To the lower
end of the pendulum is secured a heavy weight which may be made adjustable on
the pendulum and may be moved nearer the pivot for light work. At the upper
end of the pendulum is an arm extending at one side, which is connected by a link
with a hand lever. The link is connected to the arm and lever by pins that pass
through the link, and are secured by nuts. The hand lever is fitted in a support
that is a lever fulcrumed on one of the side bars of the machine. The hand lever
is held by straps that are formed upon one side of the support, and it can be
inserted or removed as desired. The bed of the punching machine is supported
upon legs bolted to the bed plate, and it is additionally braced by the side bars
which are also bolted to the bed. Between two curved standards that are secured
to the bed is fitted a slide which as well as the curved standards is slotted to
receive a bar that is connected by rods with a cross bar below the bed. A rod is
n
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page_text: connected by means of a right and left hand screw with the cross bar, the end of
the rod and the bar being apertured and threaded for receiving the screw. By
turning the screw the distance between the upper and lower die may be varied.
The slide and the bed are provided with the usual devices for holding punches,
shear blades, or dies.
The lower end of the screw rod is formed as a strap that is around an eccentric,
which is keyed to the pivot pin or axis of the pendulum. There is a ratchet wheel
also keyed to the pin and a pawl hung upon the pendulum, which pawl engages with
the teeth of the ratchet wheel being kept in contact therewith by a flat spring.
A lever is fulcrumed on the bed plate in such position that its inner end passes
beneath a lip formed on one side of the pawl, so that by depressing the outer end
of lever the pawl is raised and disengages from the ratchet wheel. This device
forms a stop motion by which the movement of the slide can be instantly arrested
while the pendulum continues to vibrate.
By moving the hand lever up and down the pendulum is oscillated, and the
pawl acts at each reciprocation of the pendulum to turn the ratchet wheel and
eccentric, and thereby move the slide up or down, according to the position of the
eccentric. The slide is thereby moved with great force, so that punching, shearing,
or stamping which has been been bitherto considered too heavy for hand work may
be readily done by this machine.
For doing light work a treadle may be substituted for the hand lever. It will
be hung on the frame of the machine in a convenient position and the weight will
be lighter than when a hand lever is used.
I will now describe a machine embodying the Invention which is intended for
shearing and punching wide plates of metal, such as that above described is not
adapted for.
In this case a head is formed with the bed, and carries shearing or punching
devices of the usual character, such devices being operated by an eccentric on a
horizontal shaft. The Invention is applied for the purpose of revolving said shaft.
The head rests upon a block that in turn rests on the floor. A standard rises
from the floor and is formed at its upper end with a bearing for the rear projecting
end of the shaft on which the ratchet wheel is keyed. The pendulum is hung on a
pin that passes through the standard. The arm at the upper end of the pendulum
is connected by a link with the hand lever as heretofore described. The upper end
of the pendulum is slotted to receive the end of a connecting rod, and the other end
of said rod is connected to a pawl carrier that is hung loosely on the horizontal
shaft above-mentioned. This pawl carrier consists of two arms, which carry
between them the pawl that engages with the teeth of ratchet wheel and is kept in
contact therewith by a spring. When the pendulum is oscillated by the hand lever
the motion is communicated by the rod to the pawl carrier, and the shaft is thereby
revolved intermittently.
The pendulum may be hung directly upon the end of the shaft next to the ratchet
wheel, dispensing with the connecting rod and permitting the use of a short instead
of a long pendulum.
A safety or stop pawl is to the used in connection with the ratchet wheel of both
machines, for the purpose of preventing back slip of the ratchet wheels during the
backward movement of the operating pawls.