Machine Ior Cutting the Thread on Two Ends of a Stud at one Operation.
Year: 1897

page_text: Date of Application, 10th Mar., 1897-Accepted, 10th Apr., 1897
Machine Ior Cutting the Thread on Two Ends of a Stud at one
Operation.
I, JAMES ROBERTSON, of Northwood, Helensburgh, Scotland, 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:-
This invention relates to an improved machine for cutting the thread on two ends
of a stud at one operation.
In carrying out my invention I provide two sets of dies or cutters one of which
revolves and the other does not. The latter I will call the stationary dies or
cutters. This stationary dies or cutters can be moved along the machine bed.
The revolving dies or cutters has an adjustable stop by which the length to be
screwed of the end of the stud next the revolving dies or cutters is determined.
Behind the stationary dies or cutters there is a sliding bolt or rod which by means
of a weighted lever is caused to press against the stud after the end has passed
through the stationary dies or cutters. The object of having this sliding bolt or
rod is to make sure that the revolving dies or cutters will complete the thread at
that end first. When this is completed the stud will force its way through the
stationary cutters and push the sliding bolt along. When the proper length of
screw on this end is cut the operator withdraws the dies or cutters in the ordinary
way catches the stud with a pair of pincers and reverses the motion of the revolving
dies or cutters to free the stud.
In order that my invention may be properly understood and readily carried into
effect I have hereunto appended one sheet of drawings in the two figures of which
corresponding parts are marked with the same letters of reference.
Figure 1 is a front view and
Figure 2 is an end view of my machine.
A represents the revolving die or cutters, B the stationary one, C is a sliding
bolt or rod which has an adjustable nut c to regulate the travel of the bolt or rod.
D is a weighted lever pivoted at d. The lower end of this lever is forked and
engages in a grooved piece c¹ attached to the bolt or rod C. The stud to be
screwed is placed between the two sets of dies, and the stationary die or cutters is
brought forward to press against the stud and the machine set in motion. If after
the stud has entered the revolving die or cutters there is more resistance there than
at the other end, the stud will begin to pass through the stationary cutters before
the end which is being operated upon by the revolving cutters has been fully
screwed; but it will be met by the end of the sliding bolt and the increased
resistance will cause the revolving dies or cutters to complete their work first. The
stud will then revolve and force its way through the stationary cutters
notwithstanding the resistance of the sliding bolt.
Instead of the weight on the lever I may employ a spring or springs or I may
work it by hand.
Having now particularly described and ascertained the nature of my inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
The improved machine for cutting the thread on two ends of a stud at one

page_text: operation consisting of a revolving die or cutters and a stationary die or cutters, in
combination with a resisting bolt or rod behind the stationary die or cutters actuated
substantially as described and illustrated.
Dated this 9th day of March 1897.
BOTTOMLEY & LIDDLE,
154, St. Vincent Street, Glasgow, Applicant's Patent Agents.