Improvements in Ropes and their Manufacture.
Year: 1894

page_text: Date of Application, 13th Dec., 1894
Complete Specification Left, 29th Aug., 1895-Accepted, 5th Oct., 1895
PROVISIONAL SPECIFICATION.
Improvements in Ropes and their Manufacture.
We, BERNHARD KIRSCH, of 59 Wahringerstrasse, IX Vienna, Austria,
Imperial and Royal Professor, and ADOLF PESSL, of 8 Kleine Sperlgasse,
II Vienna, Austria, Merchant, do hereby declare the nature of this invention
to be as follows :-
It is a well known fact that ordinary hempen ropes twisted from strands with
or without a core, have the disadvantage that between the helical coils of adjacent
strands there remain unoccupied channel-like spaces which very considerably
diminish the cross-sectional area of the rope that is available for supporting the
load thereon. This reduction or loss of cross-sectional area can be counterbalanced
only by a disproportionate increase of the thickness of the rope. But this again
is attended by an unequal strain on the threads in consequence of their different
distances from the axis, and also in consequence of the great difference of the
angles of inclination of the helices of the threads, so that the load-carrying
capacity of such ropes diminishes with their thickness, even when calculated for
equal effective cross-sectional areas.
Now the present invention relates to a method of making ropes by which the
aforesaid drawbacks are obviated, and perfectly cylindrical ropes can be made
which, whilst possessing load-supporting cross-sectional areas equal to those of
ropes made in the usual manner, are however of much less thickness than the
last-mentioned ropes.
This method of manufacture is characterized by the fact that the ropes, instead
of being made as heretofore of strands twisted together, are composed of con-
centrically arranged layers of threads or cords;. and each layer has imparted to
it a lay or twist opposite in direction or sense to that of the preceding layer.
In the manufacture of such ropes (which is effected by means of ordinary
apparatus), there is laid co-axially around a core, composed of a number of threads
twisted together, a layer of threads or cords which are taken directly from the
bobbins or reels. This layer of threads or cords encloses the core after the
manner of a shell, and is wound in a helical manner on the core in a direction
opposite to that of the lay of the core. Around this layer a second layer of
threads is then wound in a similar manner, but in the opposite direction, i.e. so
as to have a lay or twist opposite to that of the preceding layer.
In this way there are formed several co-axial layers of threads or cords, the
said layers being arranged one over another and having their lays or twists
alternately in a positive and in a negative sense, until the rope has assumed the
desired thickness.
As the fibrous material for the manufacture of these cylindrical ropes there
may be employed besides hemp, also tow, manilla, or any other known vegetable
fibrous substance suitable for manufacture into ropes.
Dated this 13th day of December 1894.
F. WISE HOWORTH,
46 Lincoln's Inn Fields, London, W.C., Agent for the Applicants.

page_text: Improvements in Ropes and their Manufacture.
We, BERNHARD KIRSCH, of 59 Wahringerstrasse, IX Vienna, Austria,.
Imperial and Royal Professor, and ADOLF PESSL, of 8 Kleine Sperlgasse,
II Vienna, Austria, Merchant, 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 :-
It is a well known fact that ordinary hempen ropes twisted from strands, with or
without a core, have the disadvantage that between the helical coils of adjacent
strands there remain unoccupied channel-like spaces which very considerably
diminish the cross-sectional area of the rope that is available for supporting the
load thereon. This reduction or loss of cross-sectional area can be counterbalanced
only by a disproportionate increase of the thickness of the rope. But this again
is attended by an unequal strain on the threads in consequence of their different
distances from the axis, and also in consequence of the great difference of the
angles of inclination of the helices of the threads, so that the comparative load-
carrying capacity of such ropes diminishes with their thickness, even when
calculated for equal effective cross-sectional areas.
Now the present invention relates to the manufacture of ropes in which the
aforesaid drawbacks are obviated, and perfectly cylindrical ropes can be made
which whilst possessing load-supporting cross-sectional areas equal to those of
ropes of given sizes made in the usual manner, are of much less thickness than such
ropes.
Ropes according to our invention instead of being made of strands twisted
together, as heretofore usual, are composed of concentrically arranged layers of
threads or cords; and each layer has imparted to it a lay or twist opposite in
direction or sense to that of the preceding layer.
In the manufacture of such ropes, which can be effected by means of ordinary
rope making apparatus, there is (as shewn in the accompanying drawings, of which
Fig. 1 is an elevation and Fig. 2 a cross section), laid co-axially around a core a
composed of a number of threads twisted together, a layer b of threads or cords
which are taken directly from the bobbins or reels. This layer of threads or cords
encloses the core a after the manner of a shell, and is laid in a helical manner on
the core in a direction opposite to that of the lay of the core. Around this layer a
second layer c of threads is then wound in a similar manner but in the opposite
direction i.e. so as to have a lay or twist opposite to that of the preceding layer.
In this way there are formed as many co-axial layers b, c, d, e, f, of threads or
cords as required, the said layers being arranged one over another and having
their lays or twists arranged alternately in a positive and in a negative sense, until
the rope has assumed the desired thickness.
As the fibrous material for the manufacture of these cylindrical ropes there may
be employed besides hemp, also tow, manilla or any other vegetable fibrous
substance suitable for manufacture into ropes.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. The herein described method of making round ropes from vegetable fibres,
according to which the threads or cords are laid over one another in concentric
layers, which are twisted alternately in opposite directions substantially as
described

page_text: 2. As a new article of manufacture, a round rope composed of concentric layers.
of threads or cords of vegetable fibrous material, the said layers having alternately
a positive and negative direction of twist or lay, substantially as herein described.
Dated this 29th day of August 1895.
F. WISE HOWORTH,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicants.