e frequently occur on surface of
patterns, remote from the action of the stripping plate, rectangular
corners just as important to mould sharply as those at the parting
line. Such corners have either to be filleted or "stooled" in
stripping plate work, and neither method often is practicable. When
the entire pattern and plate are vibrated so that the corners where
the pattern joins the plate draw perfectly, as they do in the machine
to be described, it is obvious that similar corners anywhere on
pattern surface will draw equally well.

The vibrating of patterns, or rather of moulds, during the operation
of drawing the patterns possesses little of novelty. Ever since a
bench moulder's neighbor first rapped the bench while he lifted a cope
or drew a pattern, the thing has been done in one way or another. In
fact, machines are now and then found on the market in which a device
like a ratchet or other mechanical means for jarring the machine
structure during pattern drawing renders the working of easy patterns
without stripping plates possible.

The idea of applying a power driven vibrator directly to the plate
carrying the patterns to thus vibrate them independently of other
parts of the machine and the flask and sand has been the subject of
the issue of patents to Mr. Harris Tabor, and the various figures
shown will serve to illustrate the mechanism.

Briefly, the operation of the machine is as follows: The ramming head
shown thrown back at the top of the machine is drawn into a vertical
position after flask has been placed and filled with sand. The 3-way
cock shown at the extreme left is then quickly opened, admitting
compressed air of 70 to 80 pounds pressure to the inverted cylinder
shown at the center of the cut. The cylinder, with the entire upper
portion of the machine, is thus driven forcibly up against the ramming
head, flask, sand and all. Often a single blow suffices to rain the
mould--often the blow is quickly repeated, according to the demands of
the particular mould in hand. Gravity returns the machine to its
original position, as the 3-way cock opens to exhaust. After pushing
the ramming head back and cutting sprue, if the half mould is cope,
the operator seizes the lever shown just inside the 3-way cock at the
right, and, drawing it forward and down, raises the outer frame of the
top of machine containing the flask pins, with flask and sand thereon,
away from the patterns, thus drawing them from the sand