Improvements in or relating to Processes and Apparatus for the Manufacture of Cylindrical or Conical Articles of Paper of Unequal Compactness or Porosity.
Year: 1891

page_text: Date of Application, 6th Jan., 1891-Accepted, 14th Feb., 1891
COMPLETE SPECIFICATION.
Improvements in or relating to Processes and Apparatus for the
Manufacture of Cylindrical or Conical Articles of Paper of
Unequal Compactness or Porosity.
A communication from LUDWIG GROTE, of Dresden, in the Empire of
Germany.
I, ALFRED JULIUS BOULT, of 323 High Holborn, in the County of Middlesex,
M.I.M.E., 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 process of manufacture of cylindrical or conical
articles of paper of unequal compactness or porosity, having say a core less porous
or harder than the external shell, and the invention also includes an apparatus for
carrying out such process.
This difference of porosity will prove particularly useful in those cases where up
to the present time it has been necessary to drive into the body of the article a
separate core or mandrel of hard material when it was desired to connect it with
another article passed on the same core. This mainly applies to the handles of
tools such as files, gimlets, chisels, and the like.
In the accompanying drawings,
Fig. 1 is a conical article shown half in section and half in elevation and
illustrating the manner in which the sheets or layers of paper are superposed or
made to overlap each other.
Fig. 2 shows the same cone but with the ends of the sheets of paper turned
over.
Fig. 3 is a cylindrical piece also shown partly in section and partly in
elevation.
Fig. 4 is a side elevation of the apparatus with the rollers in a parallel
position.
Fig. 5 is a front or edge view of the same, and
Fig. 6 is a side view of a machine with inclined rollers.
f
The desired difference of hardness or compactness is obtained by winding a long
paper band, both surfaces of which are suitably sized, around a rotary mandrel a of
small diameter, the pressure sustained by the paper at the beginning of this winding
operation being practically nil and increasing gradually as the successive con-
volutions of the paper band begin to form a cylinder A.
The apparatus used for this purpose consists of a frame G supporting a cylindrical
or conical mandrel a to which rotary motion is imparted from any available source.
On either side of this mandrel and parallel thereto are arranged the rollers 6 6
held in adjustable bearings c¹ in the frame G. These bearings are acted upon by
the springs ff' (either spiral or volute springs of equal strength when it is desired
to turn out cylindrical articles, or spiral springs on one side and volute springs on
the other of unequal strength when the rollers are employed for the manu-
facture of conical articles and therefore as shown in Fig. 6 are inclined at the
desired angle to each other).
In the case of the manufacture of cylindrical articles all springs fƒ¹ are equally
powerful. At first the paper band wound around the mandrel sustains no pressure
at all as the rollers b 6¹ do not then touch the mandrel a. But as the layer of
paper A grows thicker upon the mandrel and fills the space between it and the said
layers these begin to exert a uniform pressure thereon. In proportion as the
paper-roll increases in size the rollers & balong with their bearings are gradually

page_text: forced out of position by the pressure of the paper and in thus receding compress
the springs f. Owing to this uniformly and continuously increasing pressure the
upper layers of the paper-roll in course of formation are tightly compressed. The
article thus obtained to which any desired shape may subsequently be imparted on
a lathe will be found to be of an unequal degree of compactness owing to the fact
that the inner layers of paper not having undergone any pressure lie rather loosely
around the mandrel or core-bar, whereas the nearer they get to the external
circumference of the article the more tightly they are compressed by the rollers.
After removing it from the core-bar or mandrel a of the machine another mandrel
is driven into the resulting open space so as to compress the inner loose layers or
convolutions and widen the bore, while at the same time the loose layers by virtue
of their elasticity firmly adhere to the core and are firmly connected."
For conical articles (Fig. 2) rounded off at the base, such as various handles,
point protectors for lances, swords and the like (to prevent injury in military and
fencing practices) the paper bands are wound along inclines and submitted to the
pressure of inclined rollers.
For this purpose the apparatus is provided with two springs ff¹ of unequal
accommodation. To begin with the band is wound upon the core-bar a straight as
in the case of cylindrical articles. But when the roll A. thus obtained has become
sufficiently thick for the rollers to meet such resistance as to cause them to
compress their respective springs by the displacement of their bearings c c¹
until as regards the bearings ec such displacement is arrested by set screws hh,
the paper undergoing a constant pressure at that point will naturally be displaced
and the convolutions instead of forming straight layers of equal length as before,
will gradually swell at one end and thereby force the opposite end of the rollers b
into a slanting position, the bearings ce acting upon the springs ff¹ being here
capable of a more extensive displacement (Fig. 6).
Thus an arrangement of layers or convolutions of paper is obtained as
represented in Figure 1.
The bands or edges projecting beyond each other at the base of the cone may
then be turned down or rounded off by suitable instruments somewhat as shown in
Figure 2.
Having now particularly described and ascertained the nature of the said
invention as communicated to me by my foreign correspondent and in what manner
the same is to be performed, I declare that what I claim is :-
1. A process of manufacture of cylindrical or conical articles of unequal com-
pactness consisting in winding paper-bands or strips around a mandrel or core-bar
at first loosely and then with gradually increasing pressure, such pressure being
regulated by the resistance of rollers arranged to exert equal or unequal pressure
upon either end of the article in course of formation substantially as described.
2. The manufacture of a round-ended tool handle or other article by turning
over the projecting edge of the conical article produced by the oblique winding of
paper bands or strips subjected to greater pressure at one part than at another
substantially as described and illustrated in Figs. 1 and 2 of the accompanying
drawings.
3. An apparatus for carrying out the process characterized in claims 1 and 2
consisting of a frame G, rollers held in bearings adjustable laterally to the
mandrel or core-bar a, in combination with springs such as ff' controlling the
bearings c c and set screws such as h or similar stops substantially as described and
illustrated in the accompanying drawings.
Dated this 6th day of January 1801
W. P. THOMPSON & BOULT,
Agents for the Applicant.