IMPROVEMENTS IN MACHINERY FOR SCREW THREADING RODS AND BOLTS, AND FOR OTHER PURPOSES
Year: 1876

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, for the Invention of "IMPROVEMENTS IN
MACHINERY FOR SCREW THREADING RODS AND BOLTS, AND
FOR OTHER
PURPOSES." A communication from abroad by the Firm of Bouchacourt et
Compagnie, and Armand Delille, both of Paris, France.
Sealed the 19th December 1876, and dated the 30th June 1876.
PROVISIONAL SPECIFICATION left by the said Alexander Melville Clark at
the Office of the Commissioners of Patents on the 30th June 1876.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent.
"IMPROVEMENTS IN MACHINERY FOR SCREW THREADING RODS
AND BOLTS, AND FOR OTHER PURPOSES."
This Invention relates to improvements in machinery for screw threading metal
rods or bolts by pressure in dies having screw threads formed thereon, and for other
purposes.
The improvements consist, firstly, in bringing the dies together by a quick
movement, and fixing the bottom die during the operation.
And, 2ndly, in effecting the equally rapid separation of the dies for the purpose
of removing the finished article.
This rapid closing and opening of the dies is of great importance, as it avoids the
loss of time between the successive operations without affecting the strength or
stability of the lower die.
I have illustrated in the accompanying Drawing, by way of example, only a
machine embodying these improvements.
Figure 1 is a side elevation of the machine. Figure 2, a central vertical section
taken on line A, B, Figure 3, which is a horizontal section on line C, D, Figure 2.
Figure 4 is a horizontal section on line E, E, Figure 2. The same letters of
reference serve for all the four Figures.
a, b, are the screw threaded dies. The rod or bolt to be threaded is placed upon
the lower die b, and fed forward whilst screwing it. The upper die is mounted on a
slide c, which is actuated in the downward direction by eccentric e on main shaft
and toggle bar d, the upward motion being obtained by an internal spiral spring f
[Price 8d.]

page_text: 9.
The lower die b. is carried in a slide g, and is adjusted at the proper distance
from the upper die by means of wedge hand the inclined plate i beneath slide
The wedge h is operated by a pedal l, and secured in its highest position by a bolt j
received in a mortise made in the plate i, the bolt being operated by a pedal m.
In order to release the wedge and return it to its lowest position the bolt is raised
by pressing down the pedal m, whereupon the wedge is free to be returned by the
counterweight in connection with pedal l, the lower die then descending by
its own gravity sufficiently to allow of the removal of the screw bolt or rod
therefrom.
To compensate for the wear of the dies and admit of their adjustment another
wedge o, with screw adjustment, is disposed below the inclined plate i. The same
results may also be obtained by using a screw of rapid pitch, or an arrangement of
eccentrics.
The Invention is applicable also in forging other articles in dies, and in other
cases, where it is desirable, to separate the dies to remove the article.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by the
said Alexander Melville Clark in the Great Seal Patent Office on the 27th
December 1876.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent. "IMPROVEMENTS IN MACHINERY FOR SCREW THREADING RODS AND
BOLTS, AND FOR OTHER PURPOSES." A communication from abroad by the Firm of
Bouchacourt et Compagnie and Armand Delille, both of Paris, France.
This Invention relates to improvement in machinery for screw threading metal
rods or bolts by pressure in dies having screw threads formed therein, and for other
purposes.
The improvements consist, firstly, in bringing the dies together by a quick move-
ment, and fixing the bottom die in this position during the operation.
And, 2ndly, in effecting the equally rapid separation of the dies for the purpose
of removing the screw-threaded rod or bolt. This rapid closing and opening of the
dies is of great importance, as it avoids loss of time between the successive
operations without affecting the stability of the lower die during the operation.
I have illustrated in the accompanying Drawings, by way of example, only a
machine embodying these improvements.
Figure 1 is a side elevation of the machine. Figure 2, a central vértical section
taken on line A, B, Figure 3, which is a horizontal section on line C, D, Figure 2.
Figure 4 is a horizontal section on line E, F, Figure 2.
The same letters of
reference indicate the same parts in all these four Figures.
u, b, are the screw dies. The rod or bolt. to be threaded is placed upon the lower
die b, and fed forward whilst screwing it. The upper die is mounted on a slide c,
which is actuated in the downward direction by an eccentric e on the main shaft
and the toggle bar d, the upward motion being obtained by an internal spiral
spring f. The lower die b is carried in a slide g, and is adjusted at the proper
distance from the upper die by means of wedge hand the inclined plate i beneath
slide g.
The wedge his operated by a pedal l, and secured in its highest position
by a bolt j received in a mortise made in the plate i, the bolt being operated by a
pedal m. In order to release the wedge and return it to its lowest position the
bolt is raised by pressing down the pedal m, whereupon the wedge is free to be
returned by the counterweights / in connection with pedal 7, the slide g carrying
the lower die then descends by its own gravity and so separates the two dies
sufficiently to allow of the removal of the screw bolt or rod therefrom.
To compensate for the wear of the dies, and admit of their adjustment, another
wedge o, with screw adjustment, is disposed below the inclined plate ?.

page_text: I would here observe that the above is given as one example only of the method
of carrying out the principles of this Invention, and that the same results may also
be obtained by using a screw of rapid pitch, or an arrangement of eccentrics.
The Invention is applicable also in forging other articles in dies, and in other
cases where it is required to separate the dies to remove the article.
Having described the nature of the said Invention, and the manner of performing
the same, I declare that what I claim as the Invention to be protected by the
herein-before in part recited Letters Patent is, in a machine for screw threading or
forging in dies, the means of bringing the dies rapidly together, fixing the lower
die during the operation, and separating the dies rapidly, substantially as herein
shown and described.
In witness whereof, I, the said Alexander Melville Clark, have hereunto set
my hand and seal, this Twenty-seventh day of December, in the year of
our Lord One thousand eight hundred and seventy-six.
A. M., CLARK. (L.S.)