Improvements in Apparatus for the Manufacture of Helically Grooved Objects or Helically Twisted Metal Bars.
Year: 1899

page_text: Date of Application, 28th Dec., 1899
Complete Specification Left, 16th Jan., 1900-Accepted, 28th July, 1900
PROVISIONAL
DEMULTICATION
Improvements in Apparatus for the Manufacture of Helically Grooved
Objects or Helically Twisted Metal Bars.
I, JOSEF GIESHOLDT, Mechanical Engineer, of 67, Kreuzstrasse, Düsseldorf,
Germany, do hereby declare the nature of this invention to be as follows:-
The present invention has for its object, to manufacture various kinds of
spiral-shaped or helically twisted objects, such as the raw material for twist-
drills, which hitherto had to be shaped by milling cutters, by a simpler and
cheaper process, than those hitherto known.
In the accompanying drawings,
Fig. 1 is a side view of a device embodying my invention,
Fig. 2 is an end view of the same, and Fig. 3 is a partial cross section on a
larger scale.
The new device or tool chiefly comprises two kinds of rollers, viz. a set of feed
rollers for transporting the piece of work and a set of rollers which produce the
screw-threads.
The two kinds of rollers are adapted to occupy various positions in relation to
each other.
In the example represented by the drawings, two slightly grooved feed rollers t
rounded off at the circumference, and two thread-forming rollers w have been
adopted. The axes of the feed rollers t are placed at right angles across the
longitudinal axis of the piece of work to be rolled, and the thread-forming rollers w
are placed somewhat obliquely.
The two sets of rollers may be situated approximately at the same spot, (viz.,
in the same vertical plane), or one behind the other. The piece of work to be
operated upon has preferably a rectangular cross section; it is seized by the
feed rollers and propelled forward, whereupon the obliquely placed rollers w
cause the said piece to turn on its axis and at the same time impress upon it
the screw-threads, or impart to the helically twisted or grooved bar the desired
shape, so that in the case of the rolling mill represented by the drawing, the
piece of work produced by the same has the shape shown by Figs. 1 and 2, and
more clearly by Fig. 3. If only one screw-thread is to be rolled, only one thread-
forming roller is employed, and if necessary the turning of the piece of work on
its axis may be effected by a separate appliance. For rolling more than two
screw-threads, several thread-forming rollers and by preference also several feed
rollers are employed. The rollers are preferably. adjustable and easily exchang-
able, in order that different kinds of work may be produced by the same rolling
mill.
The feed-rollers t may be turned on their respective axes by any con-
venient means, the drawing shows a set of spur wheels and a belt pulley.
Dated this 28th day of December 1899.

page_text: Improvements in Apparatus for the Manufacture of Helically Grooved
Objects or Helically Twisted Metal Bars.
I, JOSEF GIESHOLDT, Mechanical Engineer, of 67, Kreuzstrasse, Düsseldorf,
Germany, 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 present invention has for its object, to manufacture various kinds of
spiral shaped objects or helically twisted bars, such as the raw material for twist
drills, which hitherto had to be shaped by milling cutters, by a simpler and
cheaper process, than those hitherto known.
In the drawings filed with the Provisional Specification,
Fig. 1 is a side view of a device embodying my invention,
Fig. 2 is an end view of the same, and Fig. 3 is a partial cross section on a
larger scale. In the drawings filed with the Complete Specification Fig. 4 is
a section of a quadratic bar serving as raw material, Fig. 5 is a section of the
same in the transition stage, along line A-B of Fig. 6, and Fig. 6 a side view
of a twist drill in course of formation from a prismatic bar.
The new device or tool chiefly comprises two kinds of rollers, viz. a set of feed
rollers for transporting the piece of work, and a set of shaping rollers which
produce the screw-threads.
The two kinds of rollers are adapted to occupy various positions in relation to
each other.
In the example represented by the drawings, two slightly grooved feed rollers t
rounded off at the circumference, and two thread-forming rollers w have been
adopted. The axes of the feed rollers are placed at right angles across the
longitudinal axis or line of feed of the piece of work or blank to be rolled, and
the thread-forming rollers w are placed somewhat obliquely, according to the
pitch of the thread to be formed.
The two sets of rollers may be situated approximately at the same spot, (viz.,
in the same vertical plane), or one behind the other. The piece of work to be
operated upon has preferably the shape of a prismatic bar; it is seized by the feed
rollers and propelled forward, whereupon the obliquely placed rollers cause the
said bar or blank to turn on its axis, thereby imparting to it a cylindrical
shape and impressing upon it the screw-threads, so that in the case of the rolling
mill represented by the drawing, the piece of work will assume the shape shown
by Figs. 1 & 2, and more clearly by Fig. 6. If only one screw-thread is to be
rolled, only one thread-forming roller is employed, and if necessary, the turning
of the piece of work on its axis may be effected by a separate appliance. For
rolling more than two screw-threads, several thread-forming rollers, and by pre-
ference also several feed rollers are employed. The rollers are preferably adjust-
able and easily exchangable, in order that different kinds of work may be produced
by the same rolling mill. The feed rollers t may be turned on their respective
axes by any convenient means; the drawing shows a set of spur wheels and a belt
pulley..
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, declare that what
I claim is:-
1. Apparatus for the manufacture of helically grooved objects or helically
twisted bars, comprising in its construction a set of feed rollers placed across the

page_text: longitudinal axis or line of feed of the blank to be rolled, thread-forming rollers
having an oblique position corresponding to the pitch of the helically twisted
or grooved object to be formed, and mechanism for turning the feed rollers on
their respective axes, substantially as described.
2. A rolling mill for the manufacture of helically grooved objects or helically
twisted bars, substantially as described and shown by the drawings.
Dated this 15th day of January 1900.
FAIRFAX & WETTER,
Agents.
37 and 39, Essex Street, Strand, London,