Improvements in Tools for Cutting and Trimming Screw Threads.
Year: 1893

page_text: Date of Application, 25th July, 1893-Accepted, 16th Dec., 1893
COMPLETE SPECIFICATION.
Improvements in Tools for Cutting and Trimming Screw Threads.
I, CLINTON ALLEN HIGBEE, residing at 1615 North Twenty-third Street, in
the City of Philadelphia, in the County of Philadelphia, in the State of
Pennsylvania, one of the United States of America, Manufacturer, do hereby
declare the nature of this invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:
My invention relates to the construction of tools for cutting down the threads of
screws and bolts so as to form screws, the threads of which will end with abrupt
shoulders. My object being to provide a convenient device to cut away the thread
and also to secure the proper adjustment and operation of the cutting tool with
respect to the die, and the device being particularly adapted for use in that class
of tools chiefly used by plumbers in which the die is loosely held in the holder by
which it is actuated.
The nature of my improvement will be best understood as described in connection
with the drawings in which it is illustrated, and in which
Figure 1 is a plan view of the tool in its preferred form.
Figure 2 a longitudinal section on the line 1-2 of Figure 1.
Figure 3 a cross section on the line 3-4 of Figure 1.
Figure 4 a section on the line 5-6 of Figure 1.
Figure 5 a section on the line 7-8 of Figure 4.
Figure 6 a view illustrating a modification of the tool actuating device.
Figure
a plan view of a modified form of tool.
Figure 8 a section on the centre line of Figure 7.
Figures 9 and 12 are views of other modified tools.
Figure 10 is a perspective view of the cutting tool holder shown in Figure 9.
Figure 11 a cross section on line 3-4 of Figure 9, and,
Figure 13 a perspective view of a screw treated by my tool.
A, Figures 1, 2 and 3, is a holder formed with a cavity A³ adapted to receive the
die C. The box like cavity is open at one side for the insertion and removal of
the die, and this opening, as shown, is closed by a plate F pivoted on a screw F¹
and adapted to be secured in place across the opening by means of a thumb-
screw F. An opening, preferably circular as indicated at A³, is formed in the
upper face of the holder to expose the die and permit the rod or pipe to pass
through, while on the opposite or lower side a similar opening is formed surrounded
by an annular sleeve A'; this sleeve serving to support a removable guide sleeve
or lining D which is secured in place by a thumb-screw E (see Fig. 3). At each
side of the holder A, sockets A' are provided and receive handles B B as shown.
C, as before stated, is the die, which, as shown in the said drawings, is provided
with cutting faces C¹ such as are used for cutting threads on pipes and rods. In
the upper face of the die is formed a recess or slide C² which may be made in any
convenient way to serve as a guide for the cutting tool G, the edge of which is
adapted to project inward and formed so that its cutting action will be brought into
play when the die is reversed so as to unscrew it from the threaded bolt or pipe
and upon which it has been secured, or which it has been used to form. L, (see
also Figure 4) is an adjustable stop secured to a lug G₁ extending from the back
of the cutting tool G, and so placed that it will come in contact with a portion
of the die C. G² G² are lugs extending upward from the face of the cutting tool
so as to embrace the end H³ of a pivoted lever H H', the pivot pin H' of which
is secured into the socket as shown. I, Figure 1, is a spring acting against the

page_text: end H of the lever pressing it out from handle B so that the end H₁ will rest
against the stop K and the tool G may be drawn back so that its edge will not
project into the cavity of the die.
In Figure 61 have shown the arm H of the lever H H' shortened and arranged
at a somewhat different angle from the similar arm in Figure 1, and have provided
a lever J pivoted at J' and having a cam shaped head J³ which rests against the
arm H, and is preferably provided with a flattened portion J' which rests against
the arm H when the tool is withdrawn from operative position and a flanged
portion J which rests against the arm H and locks it in position when the lever J
is drawn in toward the handle B to which it is attached.
The operation of the device is simple and it is used in the ordinary way of a
stock to cut a thread on a pipe or rod which is introduced through a sleeve D, the
tool being turned in the direction of the arrows in Figure 1, until the pipe or rod
is threaded for the desired distance, and then the direction of the turning reversed
to unscrew it, the screw threads on the die C shown in Figures 1, 8 and other
figures serving to direct the pipe or rod as it is unscrewed from the die so that the
tool G will neatly turn off the threads.
The
At the point from which it is desired to cut away the thread the tool G is thrust
forward by moving the lever H H either directly, as indicated in Figure 1, or by
means of the lever J as indicated in Figure 6. The distance to which the tool is
forced in is regulated by the adjustable stop L which comes in contact with the
side of the die C and prevents further forward motion of the cutting tool.
tool is held in operative position in which it entirely cuts away the thread until
the top of the rod or pipe is passed below it. By securing the cutting tool on
guides directly upon the die C and having the stop which regulates its motion act
against the side of the die I insure absolute accuracy in the operation of the cutting
tool and am enabled to use it with stocks having loose dies such as are ordinarily
used for the purpose of cutting threads on pipes.
Referring next to the modified construction shown in Figures 7 and 8, it will be
noted in the first place, that the die C is here shown as radially held in the die
holder A, the die fitting into a circular cavity indicated by a and being held in
position by a set screw a'. The die here shown, is threaded, as shown at c¹, but not
provided with cutting edges as in the case of the die first described. I have also
shown in connection with these figures, a gauge or stop O which extends over the
threaded opening c¹ and serves to arrest the forward motion of a bolt screwed into
the die; for the purpose of regulating the point at which the thread shall be cut
away this stop O is shown as screwing into a bracket M which is secured to the
die holder A by a screw N. It will also be noticed that the die holder is provided
with a single socket A' into which the handle bar B fits. In this construction also,
the cutting tool G instead of being held and guided upon the face of the die is
secured to one of the arms H³ or H of the lever H, these arms being provided
with cavities to receive the cutting tool and an adjusting screw L' for regulating
the position of the tool. In the arms H3 H4, indicates a binding screw to hold
the tool in position; the tool in this construction, as in that first described is
actuated by the motion of the lever H and the depth to which the tool shall cut
into the thread is regulated by the adjustable stops L³ L³.
In the modified construction shown in Figure 9, the tool G is carried by a head Q
which moves in guides formed with or secured to the face of the die holder A and
indicated by the letter P. The slide Q is provided with an adjusting screw Li
and formed with a cavity Q' into which fits the rounded end of an arm H or H of
the lever H.
In the construction shown in Figure 12, the arrangement is substantially similar
except that the motion of the head Q is effected by a cam head on the end of
lever H. Figure 13 indicates a screw after the thread has been cut down by my
tool, R, indicating the thread, R' the abrupt shoulder at the end of the thread
formed by the cutting action of the tool G and R' the end of the bolt from which
the cutting tool has removed the thread.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
First. As a device for cutting down screw threads, a die having a threaded
centre C adapted to screw on the screw to be treated in combination with a
longitudinally movable cutting tool G adjustably secured to said die so that its
edge can be forced against the thread of the screw or withdrawn from its path at
will, and means for moving said cutting tool longitudinally and so that its edge
will be forced within or retracted from the threaded die centre.
Second. As a device for cutting down screw threads, a die having a threaded
centre C adapted to screw on the screw to be treated in combination with a fixed
handle or handles attached to said die, a pivoted lever H secured to the die, a
cutting tool arranged to be thrust into operation by lever H and stops arranged to
regulate the movement of the cutting tool.
Third. The combination of a die C, a holder A in which the die is removably
held, a longitudinally movable cutting tool G secured in guides directly to the
die C and free to move with said die in the holder and means for moving said
tool so as to force it toward or from the die cavity substantially as specified.
Fourth. The combination of a die C, a holder A in which the die is removably
held, a cutting tool G secured in guides directly to the die C, a stop L secured
to the cutting tool and arranged to abut against the die C and means for actuating
said tool substantially as specified.
Fifth. The combination of the die C, a holder A in which the die is removably
held, a cutting tool G secured in guides directly to the die C and an actuating
lever pivoted to the holder and in engagement with the cutting tool.
Sixth. The combination of the die C, a holder A in which the die is removably
held, a cutting tool G secured in guides directly to the die C and an actuating
lever H H¹ pivoted to the holder and in engagement with the cutting tool at one
end and a cam lever J also pivoted to the holder and arranged to act on the free
end of the lever H H' as described.
Dated this 25th day of July 1893.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.