An Improved Device for or applicable to the Insertion and Extraction of Screw-studs.
Year: 1890

page_text: Date of Application, 11th Nov., 1890
Complete Specification Left, 28th July, 1891-Accepted, 19th Sept., 1891
PROVISIONAL SPECIFICATION.
An Improved Device for or applicable to the Insertion and
Extraction of Screw-studs.
I, RALPH RICHARDSON of 45 Stratford Road, Heaton, near Newcastle-on-
Tyne in the County of Northumberland, Fitter, do hereby declare the nature of
this invention to be as follows:-
:-
My invention refers to an improved device for or applicable to the insertion
and extraction of screw studs.
At present it not unfrequently happens that studs are slightly too large for their
holes due in part to the tap becoming slightly worn and thereby making a scant
hole and in part to the stud itself being manufactured somewhat "full." For this
and other reasons studs have often to be withdrawn and during this withdrawal
due to the short length available for being operated on by the nut or nuts the
thread is frequently stripped involving much labour and trouble in withdrawing
the screw-stud.
The special object of my invention is to facilitate the withdrawal of fast or other
studs and I may do so by a novel arrangement of stud-box in which one end may
be tapped or cut for the right handed thread on the stud while the upper part is
tapped or cut for a left handed screw stud intended to be used as the medium for
exerting the power necessary to withdraw the stud. The stud-box may thus be
screwed down onto and sufficiently over the projecting head of the stud to be with-
drawn while the left hand threaded stud is screwed into or enters the opposite end
of the stud-box. A collar or cushion preferably formed of a steel disc containing
a copper or equivalent central plug may be arranged so as to just pass clearly down
the left hand threaded part. The end of the power stud actuated by spanner or
lever may thus abut against one side of the collar and push it down in the stud-
box till its lower side cupped or shaped to correspond with the end of the stud to
be withdrawn abuts against this stud. The power thus communicated by the left
hand threaded stud through the stud-box and collar to the fast stud acting on an
ample surface of thread prevents any stripping thereof and effectually causes the
fast stud to "give" and then to come away.
Dated this 10th day of November 1890.
A. CRAWHALL CHAPMAN,
3, St. Nicholas' Buildings, Newcastle-on-Tyne,
Patent Agent for Applicant.
COMPLETE SPECIFICATION.
An Improved Device for or applicable to the Insertion and
Extraction of Screw-studs.
I, RALPH RICHARDSON of 45 Stratford Road, Heaton near Newcastle-on-
Tyne in the County of Northumberland, Fitter, 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 refers to an improved device for or applicable to the insertion and
extraction of screw studs.
At present it not unfrequently happens that studs are slightly too large for their
holes due in part to the tap becoming slightly worn and thereby making a scant
hole and in part to the stud itself being manufactured somewhat "full."
031

page_text: For this and other reasons studs have often to be withdrawn and during this
withdrawal due to the short length available for being operated on by the nut or
nuts the thread is frequently stripped involving much labour and trouble in with-
drawing the screw-stud.
The special object of my invention is to facilitate the withdrawal of fast or other
studs and I may do so by a novel arrangement of stud-box in which one end may
be tapped or cut for the right handed thread on the stud while the upper part is
tapped or cut for a left handed screw stud intended to be used as the medium for
exerting the power necessary to withdraw the stud. The stud box may thus be
screwed down onto and sufficiently over the projecting head of the stud to be with-
drawn while the left hand threaded stud is screwed into or enters the opposite end
of the stud box. A collar or cushion preferably formed of a steel disc containing
a copper or equivalent central plug may be arranged so as just to pass clearly down
the left hand threaded part. The end of the power stud actuated by spanner or
lever may thus abut against one side of the collar and push it down in the stud box
till its lower side cupped or shaped to correspond with the end of the stud to be
withdrawn abuts against this stud. The power thus communicated by the left
hand threaded stud through the stud box and collar to the fast stud acting on an
ample surface of thread prevents any stripping thereof and effectually causes the
fast stud to "give" and then to come away.
I will now fully describe my invention with reference to the accompanying
drawings in which
Figure 1 shows a sectional elevation and Figure 2 an elevation of the device
constituting my invention.
Figure 3 is a sectional view hereinafter again referred to.
Like letters of reference designate like parts throughout the following description.
Referring to the drawings A is the stud box tapped or cut at its lower end to
take the right handed thread on the stud A¹ while the upper part is tapped or cut
for a left handed screw stud A2 intended to be used as the medium for exerting the
power necessary to withdraw the stud; the end A³ of stud A³ may be formed
either as shown in Fig. 1 slightly diminished in diameter so as to allow it to pass
down just clear of the lower threads of the stud box and with a properly case
hardened recess or formation on its end corresponding more or less to the shape of
the head of the stud A' or as shown in Fig. 3 a loose collar or cushion may be
inserted preferably formed of a steel disc A containing a copper or equivalent
central plug A. In the latter arrangement the power stud A2 is designed to abut
against one side of the collar or disc and push it down in the stud box till its lower
side abuts against the end of the stud A¹.
I prefer, however, to use the apparatus shown in Fig. 1, as it is less complicated
and involves less parts than that just described.
The action of my improved device is as follows:-
To draw a stud, first screw the stud box well onto the head of the stud to be
withdrawn so as to get a good thread-grip taking care that the power stud A² is
sufficiently far back in the box; then holding the stud box in the left hand to
prevent its turning, screw down the power stud till its end abuts against the head
of the stud to be withdrawn, when by continuing the screwing down of the power
stud, by means of a spanner acting on its head, stud box and stud A' are likewise
caused to revolve and the stud is thus withdrawn.
To insert a stud, screw stud box down onto stud head and screw down power
stud onto head of stud to be inserted, then with spanner acting on canted outside
of stud box, the stud can be easily inserted.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what I
claim is
1. The improved device for or applicable to the insertion and extraction of

page_text: DCrew Studs substantially as herein described and illustrated in the accompanying
drawings.
Dated this 22nd day of July 1891.
A. CRAWHALL CHAPMAN,
3, St. Nicholas' Buildings, Newcastle-on-Tyne,
Patent Agent for Applicant.