Improvements in Screw-thread Cutting Tools.
Year: 1897

page_text: Date of Application, 2nd Mar., 1897
Complete Specification Left, 22nd Nov., 1897-Accepted, 15th Jan., 1898
Improvements in Screw-thread Cutting Tools.
(A communication by MARTIN STEUDNER, of Gera-Debschwitz, in the Empire of
Germany, Tool Maker.)
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.L.M.E., of the Agency for Foreign
Patent Solicitors, 6 Lord Street, Liverpool, and 6 Bank Street, Manchester,
both in the County of Lancaster, 118 New Street, Birmingham, in the County of
Warwick, and 322 High Holborn, in the County of Middlesex, Civil Engineer,
do hereby declare the nature of this invention to be as follows:-
This invention has for its object improvements in screw-thread cutting tools,
such as screw taps and dies or the like and is characterised by the cutting edge,
which comes in question in subsequent grinding, being recessed or cut away
underneath, thereby leaving only a very narrow surface to be ground in the
subsequent grindings.
A further advantage consists in the cutting edges being quite free from danger
to the workman and being capable of being ground on any shaped-edge emery
disc or grindstone.
In the accompanying drawings, Figure 1 shows a screw tap shaped or cut away
after the manner of this invention, Figure 2 is a cross section of Figure 1.
Figures 3 to 5 show screw cutting dies also cut away underneath in the manner
mentioned, whilst Figures 6 and 7 show respectively elevation and cross section
of screw chasers shaped or cut out below in this manner.
As may be seen from the drawing, the cutting surfaces a and b are provided
with a hollow recess c, so that the cutting element is formed by a freely projecting
ridge d, and in the subsequent grinding of the tap die or cutting tool, it is only
necessary to grind the narrow surface a. By the arrangement of the hollows or
recesses c the surface which is to be sharpened or ground may be more conveniently
acted upon by the grinding tool. Such cutting tools have further the great
advantage that they may be simultaneously hardened because the ridge d has the
same section almost entirely all through.
Dated this 1st day of March 1907
(A communication by MARTIN STEUDNER, of Gera-Debschwitz, in the Empire of
Germany, Tool Maker.)
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of the Agency for Foreign
35 Patent Solicitors, 6 Lord Street, Liverpool, and 6 Bank Street; Manchester,
[Price &11

page_text: both in the County of Lancaster, 118 New Street, Birmingham, in the County of
Warwick, and 322 High Holborn, in the County of Middlesex, Civil Engineer, 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 has for its object improvements in screw-thread cutting tools,
such as screw taps and dies or the like and is characterised by the cutting edge,
which comes in question in subsequent grinding, being recessed or cut away
underneath, thereby leaving only a very narrow surface to be ground in the
subsequent grindings.
A further advantage consists in the subsequent grinding of the cutting edges
being quite free from danger to the workman and being capable of being effected
on any shaped-edge emery disc or grindstone.
In the drawing accompanying the provisional specification,
Figure 1 shows a screw tap shaped or cut away after the manner of this
invention;
Figure 2 is a cross section of Figure 1;
Figures 3 to 5 show screw cutting dies also cut away underneath in the manner
mentioned; whilst
Figures 6 and 7 show respectively elevation and cross section of screw chasers
shaped or cut out below in this manner.
As may be seen from the drawing, the cutting surfaces a and b are provided
with a hollow recess c, so that the cutting element is formed by a freely projecting
ridge d, and in the subsequent grinding of the tap die or cutting tool it is only
necessary to grind the narrow surface a. By the arrangement of the hollows or
recesses e the surface which is to be sharpened or ground may be more conveniently
acted upon by the grinding tool. Such cutting tools have further the great
advantage that they may be evenly hardened because the ridge d has the same
section almost entirely all through.
Having now particularly described and ascertained the nature of the said 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:-
A screw-thread cutting tool characterised by the cutting edge which comes in
question being provided with recesses or cut away underneath so that in the
subsequent grindings only a narrow surface requires to he ground, whereby the
subsequent grinding of the tool may be effected better, easier and without danger,
substantially as herein before set forth.
Doted this 20th day of Novambon 1807