Improvements in and relating to Devices for Cutting Screw- threads.
Year: 1891

page_text: Date of Application, 23rd June, 1891
Complete Specification Left, 19th Mar., 1892-Accepted, 23rd Apr., 1892
PROVISIONAL SPECIFICATION.
[Communicated from abroad by F. C. THURMER, of Copenhagen, in the Kingdom
of Denmark, Book-keeper.]
Improvements in and relating to Devices for Cutting Screw-
threads.
I, HENRY HARRIS LAKE, of the firm of Haseltine Lake & Co., Patent
Agents, 45 Southampton Buildings in the County of Middlesex, do hereby
declare the nature of this invention to be as follows:-
:-
This invention relates to a device for cutting screw-threads.
The improved device constructed according to the said invention comprises a die-
stock provided with a sliding-piece adapted to receive taper dies having different
screw-threads and a tap of special construction. This device enables the screw-
thread to be produced approximately in the same time as by a screw-cutting
machine actuated by hand, whilst it can be made at one-sixth of the cost of such a
machine.
The die-stock has at its ends handles, and in its rectangular part a row of holes
of various diameters. A sliding-piece in which the die is placed and which is held
in a definite position by means of a set screw may be displaced along the middle
part of the die-stock. The interior surfaces of the said sliding pieces, which
embrace the die and die stock are inclined to each other so that the latter are
guided in the said sliding-piece.
In use the sliding-piece is so adjusted that the hole in the die will be exactly
opposite the hole in the die-stock, the size of this hole corresponding to the bolt to
be screw-threaded. By this means the bolt will then be completely guided during
the cutting.
The above mentioned tap is made taper and its frout part has a screw-thread the
outer diameter of which is smaller than the inner diameter of the screw-thread on
the main part. This enables the nuts in which the holes are too small to be tapped
without any necessity for enlarging or expanding the said holes by means of a
mandrel.
The intermediate part between the two screw-threads which has no screw-thread
serves partly as a broach and partly as a guide. In the case of nuts having holes
of sufficiently large size the said intermediate part serves simply as a guide. The
main part of the tap, which is generally not longer than the diameter of the latter
will enable the nuts to be screw-threaded in one-third of the time which has
heretofore been needed.
Dated thi. 021 day of Tune 1901
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in and relating to Devices for Cutting Screw-
threads.
1, HENRY HARRIS LAKE, of the firm of Haseltine Lake & Co., Patent
Agents, 45 Southampton Buildings in the County of Middlesex, 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 a die-stock which has a sliding piece adapted to receive

page_text: taper dies with different screw-threads, and to a tap of special construction, which
has an intermediate part serving as a guide and broach, the whole device being so
arranged that a uniform screw-thread will be produced in approximately the same
time as through the medium of a screw-cutting machine actuated by hand, whilst
it can be made at one-sixth of the cost of such a machine.
In the accompanying drawing,
Figure 1 shows the die-stock as seen from above, the die being inserted;
Figure 2 is a side view of the stock;
Figure 3 shows it as seen from below.
Figure 4 is an end view of the sliding-piece.
Figure 5 represents the tap with an intermediate part used as a guide and broach
and,
Figure 6 shows an end view of the same.
The dic stock C has at its ends handles, and in its rectangular part a row of holes
of various diameters. A sliding-piece which receives the die a held by a set
screws may be displaced along the middle part of the dic-stock, and held in definite
positions through the medium of the set screw a. As shown in the drawing, the
interior surfaces of the said sliding pieces, both those which embrace the die and
those which embrace the die-stock, are inclined to each other so that the die-stock
and die will be guided in the said sliding piece.
In use, the sliding-piece is so adjusted that the hole in the die will be exactly
opposite the hole in the die-stock, the size of this hole corresponding to the bolt to
be screw-threaded. By this means the bolt will be properly guided during the
screw cutting.
The tap E is made taper and its front part a has a screw-thread, the outer
diameter of which is smaller than the inner diameter of the screw-thread on the
main part c.
This enables the nuts in which the holes are too small to be tapped
without any necessity for enlarging or expanding the said holes by means of a
mandrel or a rimer.
The intermediate part between the two screw-threads which is left blank serves
partly as a broach and partly as a guide. In the case of muts having holes of
sufficiently large size the said intermediate part serves simply as a guide whilst the
taper main part, which by reason of the parts a and b is made very short, namely
of the same length as the diameter of the tap will enable the nuts to be screw-
threaded in one-third of the time which has heretofore been occupied in this
operation.
Owing to the taper form of the tap the length of the said main part must not be
greater than the diameter of the tap.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, as communicated to me by
my foreign correspondent, I declare that what I claim is :-
The improved device for cutting screw threads, comprising the stock C provided
with an adjusting screw and the sliding piece B holding the taper die A and
having holes of different sizes, and the taper tap E having a main screw-threaded
part c, an intermediate part 6 which may serve as a guide and broach, and the
screw-threaded part a, substantially as shown and described.
Dated this 19th day of March 1892.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.