Improvements in Devices for Use in Drawing Tubes.
Year: 1895

page_text: Date of Application, 20th June, 1895-Accepted, 20th July, 1895
COMPLETE SPECIFICATION.
Improvements in Devices for Use in Drawing Tubes.
1, CARL GUSTAF LARSON, of Sandviken, in the Kingdom of Sweden, 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 relates to a device for drawing tubes and is intended to replace the
tongs which have hitherto be used in tube drawing operations for gripping the tubes.
The tongs as heretofore employed have many inconveniences, as for instance the
n:arks caused thereby in the pipes, the necessity of providing special means for
preventing the tube from being pressed together and such like.
These inconveniences are however obviated by the employment of the gripping
device forming the subject of the present invention.
In the accompanying drawing
Figure 1 is a longitudinal section of the improved device and
Figure 2 is a similar section of a modified form of the said device.
The said gripping device comprises a drawing eye a having a conical core 6 the
width of which increases towards the inner end of the same, and a ring c with a
conical bore adapted to fit on the said core. The core, which is provided with
small cross grooves, is pushed into the end of the tube which is slit up, so that it
can be pressed together upon the core along that part thereof which corresponds
to the length of the said core. After pressing together the strips or parts of the
end of the tube the ring is pushed upon the same. When drawing by means of the
eye a the tube is jammed tightly between the core and the ring, owing to the tendency
of the core to press the strips of the tube outwards towards the ring. In this manner
the tube is gripped and operated more steadily than has been possible by means of
tongs or the like.
The modification shown in Figure 2 consists of two-part sleeves or rings df
placed between the core and the tube and between the tube and the ring. The
ring d has a conical inside so that it fits on the core, while the outside of the same
is provided with cross grooves. The ring f is on its inside provided with ridges
and has a conical outside, so that it fits in the ring. When pulling on the core b
the tube is jammed in the manner above described. In some cases it may be found
suitable to have a divided sleeve between the tube and the core but otherwise
to have the gripping device constructed as shown in Figure 1. By the employ-
ment of sleeves the cutting up of the tube can be avoided. If the tube wall is not
too thick the slitting up may be dispensed with when employing the core and the
ring alone.
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 :-
1. A gripping device for the tubes in tube drawing apparatus and the like,
consisting of a conical core adapted to be pushed into the tube with its largest
end directed inward, and a ring adapted to be pushed upon the slit up end
of the tube surrounding the core, with the object that when pulling the core which
is provided with an eye or the like, the tube may be jammed between the core and
the ring

page_text: 2. In the gripping device above described, the arrangement of a couical sleeve
or ring between the core and the tube and between the tube and the ring or
only between the core and the tube and of which sleeves the outer one is
externally wider at the inner end, while the inner ring is internally wider at the
inner end.
Dated this 20th day of June 1895.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.