Improvements on Screwing Die Box" for use on Screwing Machines and Lathes.
Year: 1892

page_text: Date of Application, 15th Mar., 1892
Complete Specification Left, 29th Oct., 1892--Accepted, 3rd Dec., 1892
PROVISIONAL SPECIFICATION.
66
Improvements on Screwing Die Box" for use on Screwing
Machines and Lathes.
ROBERT LANG Engineer, of the firm of John Lang & Sons, Lathe Manu-
facturers & Tool Makers, Laigh Cartside Street, Johnstone near Glasgow, do
hereby declare the nature of this invention to be as follows:-
The object of this invention is, to make the dies of such a shape or section,
and fix them in die box, in such a manner, that no plate, or covering intervenes
between dies, and chuck holding the work to be screwed; thus allowing the work
to be easily seen when screwing articles up to a shoulder.
The die box is of the type already in use, where the dies are fixed into slides
which are moved out and in by means of eccentric plate, when withdrawing dies
from work or setting them to size.
The dies are quadrilateral in section, having both ends square to one side and
one end thicker than the other, forming a wedge shape section, one side being
angular to the other. Each die is fitted to sliding holder with the angled side
opposite to the set pins which keep the die in position on sliding holder; one
of the set pins has V point fitting into corresponding V countersunk in die, to
ensure its diametral position being correct; the thinner portion of die being at
front of die box or sliding holder, with the thick portion at back, the die is
securely held in position, owing to its wedge shape, without set pin or plate in
front of die.
Dated this Fourteenth day of March 1892
COMPLETE SPECIFICATION.
Improvements on "Screwing Die Box" for use on Screwing
Machines and Lathes.
ROBERT LANG Engineer of the firm of John Lang & Sons, Lathe Manu-
facturers & Tool Makers, Laigh Cartside Street Johnstone, County of Renfrew
North Britain 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 :-
The object of this invention is to make the dies of such a shape or section and fix
them in die box in such a manner that no plate or covering intervenes between dies
and chuck holding the work to be screwed. In order that my invention may be
properly understood, I append a drawing showing how my improvement affects an
ordinary screwing head. Only such parts as are necessary for explaining the
invention are drawn.
In the several figures of the drawing corresponding parts are marked by the
same letters of reference.
Fig. 1 shows a front elevation of a screwing head to which this invention is
applied. This screwing head can be fixed to the saddle of a lathe or on a turret
head, or it can be arranged in connection with any machine where screwing dies
are used.
Fig. 2 is an end elevation.
Fig. 3. is a section of head on line a. b.
The slides C. C. C. have grooves cut in them for the purpose of holding the

page_text: their place by the two pinching pins e. e¹ one of which e' is taper pointed and fits
into a dimple bored in die. It will be seen that when these pins are screwed up,
the dies will bear hard on facef owing to the side G of die being bevelled. The
dimples in the dies allows them to be set correctly in relation to each other.
The handle H is for moving the dies into position for screwing and when the
work has been screwed it withdraws the dies in the usual manner.
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
The screwing dies instead of being rectangular in section as is the usual
practice, they are made with one side bevelled, no plate in front being required
and this allows the dies to be flush with the front of die holder, which arrange-
ment enables work to be screwed up to a shoulder and the cutting edges of dies
are more fully exposed to view of the operator than in other die boxes which
have plate or parts in front of dies.
Dated this Twenty-seventh day of October Eighteen hundred and ninety-
ROBERT LANG..