A Mandrel for the Manufacture of Paper Tubes and the like.
Year: 1894

page_text: Date of Application, 28th June, 1894-Accepted, 28th July, 1894
COMPLETE SPECIFICATION.
A Mandrel for the Manufacture of Paper Tubes and the like.
A communication, from LUDWIG GROTE, Factory Manager, of Landsburg,.
Oberbaiern, (Upper Bavaria), in the Empire of Germany:
I, ALFRED JULIUS BOULT of 323 High Holborn, in the County of Middlesex,.
Chartered Patent Agent, do hereby declare the nature of this invention an 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 mandrel, for use in the manufacture of paper-tubes
and the like, of any desired length.
Whereas, hitherto, it has been the practice to employ for this purpose smooth
rolls, lubricated with fat, or enveloped in tissue, or other special devices to render
the contraction or enlargement of the rolls possible, with which process besides
being very slow, only tubes of limited length could be obtained. Under the present
invention a hollow or solid mandrel is employed made of iron or the like, and
provided with a peculiarly cut screw-thread.
Fig. 1 in the drawings is a view of the complete mandrel.
Fig. 2 is a longitudinal section of the mandrel with the material enveloping it.
Fig. 3 is a transverse section of the same.
On the pipe or roller forming the mandrel a, an extremely flat thread bis first-
cut, so that the convolutions of the screw may have a very steep pitch and the
threads be as close together as possible. The edges of the thread are then cut
away at the sides with a specially formed steel cutter, and so rounded off as to
assume either a half-round or pointed form as shown in the drawings.
When this screw-threaded roller is enfolded in the material which may be paper,
linen or other like substance, and is first steeped in some adhesive semi-fluid
substance, it will be wound only on the rounded or pointed screw-thread; and there
will consequently be formed on the inner surface of the gradually hardening paper
tube a corresponding hollow or female screw-thread. If now it be required to-
withdraw the mandrel a from the finished tube c, it will suffice to hold the tube
fast while the mandrel is forcibly turned partly round to and fro, for which purpose.
the projecting end of the mandrel is seized with a pair of pipe-tongs or other like
appliance partaking of the nature of pincers and a lever handle. The adhesive
wrappings having thus been loosened and torn away, the mandrel a can be unscrewed
from within the paper tube c, leaving a smooth female screw-thread inside the
paper-tube. Subsequently, if it be required to finish off the same still further,
the mandrel can be screwed into the tube once more, and again withdrawn.
Having now particularly described and ascertained the nature of the said
invention, as communicated to me by my foreign correspondent, I declare that what.
I claim is ;-
A mandrel for use in the manufacture of paper tubes or the like having a screw-
thread formed on it with edges rounded off or pointed by rotation of which a
corresponding screw-thread is formed on the inner surface of the tube enabling the
mandrel to be withdrawn or inserted by unscrewing or screwing it within this tube
substantially as described and illustrated in the accompanying drawings.
Dated this 28th day of June 1894.
W. P. THOMPSON & BOULT,
Agents for the Applicant.