Improvements in Hand Tools for Trimming and Screwing Bolts and the like.
Year: 1893

page_text: COMPLETE SPECIFICATION.
Improvements in Hand Tools for Trimming and Screwing Bolts and
the like.
I, HEINRICH GEORG HELD of Almelo, Holland, 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 a tool for turning bolts, screws and the like,
particularly for small tradesmen, locksmiths, smiths, and so forth, whom it will in
many cases serve in lieu of a lathe.
Whilst bolts and the like had heretofore to be trimmed to size by filing, which
even after laborious loss of time did not make the same perfectly round and neat,
this tool permits such operation to be made rapidly and with exactness.
In the accompanying drawings, Figure 1 is an elevation, Figure 2 section on
line, Figure 3 section on line y-y, Figures 4 and 5 show a box tool, Figures 6
and 7 a similar tool that is adapted for screw-cutting, Figures 8 to 10 cheek-pieces
showing the adaptation of the tool to various shapes.
Contrary to the usual construction, a closed box A is used according to this
invention, and this, set into a suitable clamp, and if fitted with cutting surfaces
only (see Figures 4 and 5), serves for trimming a bolt, whilst if arranged as shown
in Figures 6 to 10 it will serve for screw cutting also.
The inner side of the box A Figures 4 and 5, has concentric faces a undercut by
channels b, the latter permitting the "turnings" cut by the tool to escape from the
box A. The interior diameter of the box, and therefore that of the cutting edges c,
gradually diminishes until the size to which the bolt is to be trimmed is reached.
If the bolt is not only to be trimmed but threaded also, the first part only of the
faces a, is smooth and gradually merges into a screw thread, that is to say the
beading end of the edges c, is plain, their end forming thread cutters. It is,
however, better in this case to construct the box as shown in Figures 8 to 10,
namely in three parts A1, A2, A3 held together by screws d, and this not only
facilitates sharpening of the tool but (by the insertion of plates of different internal
diameter) affords the great advantage of making the tool applicable for bolts of
various sizes.
Im
m/
A set of twelve discs or plates A' and A³ (Figures 8 and 9) measuring 5 m/m
67m
&c. to 16 mm in the clear with a set of 10 discs A² (Figures 8 and 9)
for screw cutting, having internal diameters of 6 m/m 7 mm &c. to 15 m/m will allow
bolts of different sizes from 5 to 14 "/m to be operated upon.
To cut a bolt to say 10mm, a first cutter A3 of 12 internal diameter is used
followed by a screw cutting tool A2 of 11 and then on the top a finishing
cutter A of 10 in the clear, whilst for a bolt of 8, the cutter A¹ (previously
used for finishing is used as first cutter, followed by another of 9½ diameter and
then one of 8
These illustrations enable those used to similar kinds of tool to combine the cutters
as required in practice.
When a tool having the disc or plate in three parts is to be used for screw-
cutting, the thread-cutter is placed on the top. In this manner various sizes of
bolts can be trimmed and threaded.

page_text: 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
A tool for trimming or screw cutting constructed substantially as set forth and
illustrated in the drawings.
Dated this 28th day of June 1893.
BERNHARD DUKES,
226, High Holborn, London, W.C., Applicant's Agent.