IMPROVED APPARATUS APPLICABLE TO TURNING AND SCREW CUTTING
Year: 1867

page_text: PROVISIONAL SPECIFICATION left by Alfred Vincent Newton at the
Office of the Commissioners of Patents, with his Petition, on the
26th September 1867.-A communication from abroad by William
Thomas Cole, of the City of New York, United States of America.
I, ALFRED VINCENT NEWTON, of the Office for Patents, 66, Chancery Lane,
in the County of Middlesex, Mechanical Draughtsman, do hereby declare the
nature of the said Invention for "IMPROVED APPARATUS APPLICABLE TO TURNING
AND SCREW CUTTING," to be as follows:-
This Invention relates to a new and improved means for cutting screw
thrends on pipes, bolts, and rods, whereby the work may be done with far
greater rapidity than hitherto.
The Invention consists, first, in an improved clamp for clutching the pipe or
rod to be acted upon, and causing it to turn with the mandril whenever the
latter is turned, the pipe or rod being released when the rotation of the
mandril ceases, the clamp being consequently self-acting, and admitting of the
pipes or rods being inserted in and withdrawn from it without any appreciable
loss of time.
The Invention consists, secondly, in a novel die for cutting the screws on the
pipes or rods, whereby the die may be made at the will of the operator or
attendant to grasp the pipe or rod, or be released therefrom. Secured to the
mandril of a lathe or screw-cutting machine, so as to rotate therewith, is a
disc perforated at the centre to receive the pipe or rod to be operated on.
This disc has a recess in its face in which pawls are fitted to bite and hold the

page_text: pipe or rod. These pawls are each formed with a socket joint at their outer
ends, which are fitted in recesses in the disc and allowed to rock therein.
The inner ends of these pawls are rounded or curved, and they are furnished
with a double set of steel gripping teeth. The pawls are connected by screws
to a circular cap plate which is fitted over the disc and allowed to turn
thereon, and by turning the disc the pawls may be adjusted to bring one or
other set of teeth into contact with the pipe or rod. The cap plate may be
held in position or prevented from casually moving by any proper means. This
arrangement forms a clutch, which will firmly hold the pipe or rod and present
it to the turning tool or screw-cutting dies simply by the rotation of the
mandril in either direction. When however the disc is stationary, or has no
motion, the teeth will not clutch the pipe, and the latter may be inserted in
or passed through the disc and withdrawn therefrom without any difficulty
whatever.
For cutting screw threads the following arrangement is provided :-A plate,
say, of cast iron, is secured in position facing the disc. This plate has a
circular opening made through it, and to the plate there are attached by pivot
bolts two half dies, which through a spring have a tendency to fly open.
When at work they are kept in a closed state by a sliding clutch which is
held down by a spring. The clutch is connected to a pivotted bar which is
raised by a lever. The clutch rising with the bar liberates the dies, which
are then free to open. The dies are closed upon the work by a hand lever
arrangement.