IMPROVE- MENTS IN THE MANUFACTURE OF WIRE ROPE OR CABLE FOR ENDLESS CABLE TRACTION RAILWAYS OR TRAMWAYS, ELEVATORS OR VERTICAL RAILWAYS, AND OTHER LIKE PROPELLING AND SIMILAR PURPOSES
Year: 1883

page_text: LETTERS PATENT to Thomas Seale, a Citizen of the United States residing in
the City and County of San Francisco, State of California, one of the United
States of America, Railway Superintendent, for an Invention of " IMPROVE-
MENTS IN THE MANUFACTURE OF WIRE ROPE OR CABLE FOR ENDLESS CABLE
TRACTION RAILWAYS OR TRAMWAYS, ELEVATORS OR VERTICAL RAILWAYS,
AND OTHER LIKE PROPELLING AND SIMILAR PURPOSES »
.
PROVISIONAL SPECIFICATION left by the said Thomas Seale at the Office
of the Commissioners of Patents on the 4th April 1883.
THOMAS SEALE, a Citizen of the United States residing in the City and County
of San Francisco, State of California, one of the United States of America, Railway
Superintendent "IMPROVEMENTS IN THE MANUFACTURE OF WIRE ROPE OR CABLE
FOR ENDLESS CABLE TRACTION RAILWAYS OR TRAMWAYS, ELEVATORS OR VERTICAL
RAILWAYS, AND OTHER LIKE PROPELLING AND SIMILAR PURPOSES
"
My invention relates to improvements in the manufacture of wire rope or cable
for endless cable traction tramways, elevators or vertical railways, and for other
like propelling purposes.
The object of my invention or improvement is to produce a propelling or
traction cable, as I shall hereafter term it, in which a high degree of flexibility
is obtained with the required strength and an increased durability and
seviceableness.
To such end and purpose my invention or improvement consists in forming the
heart, or the central and vital part, of a strand, of a number of wires that are finer
or of a higher gauge than those which are employed for the wrapping, cover or
protection to the heart; whereby a strand for the manufacture of wire rope or
cable is produced wherein the heart or vital part is stronger, more flexible and bas
greater durability than is possessed by strands of the ordinary form style or
character now employed for the manufacture of wire rope or cable.

page_text: The following description fully explains the nature of any said invention and
the manner in which I proceed to construct, apply, use and carry out the same.
In the manufacture of wire cables as furnished and employed for street cable
Railways, and other propelling purposes, at the present time, it has been the
practice to form first the center portion or heart of each strand from wire of the
same size or gauge as that employed for the cover wrapping or outside of the strand.
Seven wires of a gauge determined and regulated by the size of the rope or cable
to be produced are twisted together by the aid of twisting machinery, and then by
the same means a number of wires of the same gauge are laid around this heart or
center to form the wrapping. Several of these strands are afterwards twisted
together to form the cable.
•
Now, this construction while applicable to standing cables is defective as applied
to cables for propelling purposes, or as I term them traction cables, because the
forces and agencies to which such traction cables are subject in passing around
drums in running over and under pullies and sheaves and in being compressed
between the jaws of gripping devices are destructive to the heart of the strands.
As long as these hearts are preserved the cable is serviceable but when they are
broken or worn or crystallized the life of the cable terminates.
To produce my improved cable I proceed substantially as follows:-
By means of rope twisting machinery of the kind suitable for the purpose, I form
a core, by twisting together a number of wires of finer gauge than those to be
employed for the cover or outer body of the strand, and then I lay over this center
a firm cylindrical body of fine wires to form the heart. These wires are about four
numbers, B. W. G> finer than the covering wires.
Around this heart I then lay a wrapping or protecting covering of coarse wires.-
In constructing a six strand propelling cable of one and one quarter inches diameter
I have employed N° 17, wire <B. W. G. for the heart and N° 13, for the
covering as giving perhaps the best results and qualities of strength, with required
'degree of flexibility for such size of cable.
But I do not desire to be understood as limiting my construction to any precise
difference or proportion between the two grades of wire to be employed for the
inside and the outside of the strand, as this depends upon and is governed by the
strength required for the heart and the work to be performed. It being evident,
that to increase the flexibility of the cable it is only necessary to reduce the size of
the wires forming the heart of the strands.
To produce a cable a number of these strands are twisted together around a core,
usually hempen, and the cable is ready for use.
This improved construction of strand enables me to obtain a smoother surface for
the outside of the heart; also to produce a firm close heart of a greater number of
wires without increasing the diameter of the strand and obtain a strong yet flexible
strand.
I am aware that cables adapted for traction purposes have been made with a soft
flexible core or center of hemp both within the strands and in the center of the
cable. But such strands have comparatively no durability, for the reason that the
life or energy of the strand should be located in the center, because the outside is
subject to extraordinary compression from the jaws of the gripping devices, and the
outside wires are continually being cut and abraded by the grip. I am not aware
however that a cable for propelling and similar purposes has ever before been
produced having a heart of fine wire exceeding seven in number and a cover or
outside protection of heavier wires as herein set forth and described."

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Thomas Seale in the Great Seal Patent Office on the
28th September 1883.
THOMAS SEALE, a Citizen of the United States, residing in the City and County
of San Francisco, State of California, one of the United States of America, Railway
Superintendent, "IMPROVEMENTS IN THE MANUFACTURE OF WIRE ROPE OR
CABLE FOR ENDLESS CABLE TRACTION RAILWAYS OR TRAMWAYS ELEVATORS OR
VERTICAL RAILWAYS AND OTHER LIKE PROPELLING AND SIMILAR PURPOSES "
My invention relates to improvements in the manufacture of wire rope or cable
for endless cable traction tramways, elevators or vertical railways, and for other
like propelling purposes.
The object of my invention or improvement is to produce a propelling or traction
cable, as I shall hereafter term it, in which a high degree of flexibility is obtained
with the required strength and an increased durability and serviceableness than
has been heretofore attained.
To such end and purpose my invention or improvement consists in forming the
heart or the central and vital part of a strand of a number of wires that are finer
or of a higher gauge than those which are employed for the wrapping, cover or
protection to the heart, whereby a strand for the manufacture of wire rope or
cable is produced wherein the heart or vital part is stronger, more flexible and has
greater durability than is possessed by strands of the ordinary form style or
character now employed for the manufacture of wire rope or cable.
The following description fully explains the nature of my said invention and
the manner in which I proceed to construct, apply use and carry out the same.
In the accompanying drawing herein referred to by figures and letters.
Figure 1. represents a piece of wire cable produced from six strands and a
core, the covering wires on one of the strands being unwrapped and cut off to
show the structure of the heart or inner portion of the strand.
Figure 2-is a cross section at any point through fig: 1
In the manufacture of wire cables as furnished and employed for street cable
railways, and other propelling purposes at the present time before the date of my
invention, it has been the practice to form first the centre portion or heart of each
strand from wire of the same size or gauge as that employed for the cover wrapping
or outside of the strand. Seven wires of a gauge determined and regulated by the
size of the rope or cable to be produced are twisted together by the aid of twisting
machinery and then by the same means a number of wires of the same gauge are
laid around this heart or centre to form the wrapping. Several of these strands
are afterwards twisted together to form the cable.
Now this construction while applicable to standing cables is defective as applied
to cables for propelling purposes or as I term them traction cables, because the
forces and agencies to which such traction cables are subject in passing around
drums in running over and under pullies and sheaves and in being compressed
between the jaws of gripping devices are destructive to the heart of the strands.
As long as these hearts are preserved the cable is serviceable but when they are
broken or worn or crystallised the life of the cable terminates.
To produce my improved cable I proceed substantially as follows:-
By means of rope twisting machinery of the kind suitable for the purpose I

page_text: form a core, a, by twisting together a number of wires of finer gauge than those to
be employed for the cover or outer body of the strand, and then I lay over this
centre a firm cylindrical body of fine wires a, a, to form the heart A. These wires
are about four numbers (B. W. G.) finer than the covering wires.
Around this heart, A, I then lay a wrapping or protecting covering B, of coarse
wires b, b,. In constructing a six strand propelling cable of one and a quarter inches
diameter I have employed N° 17'/, wire (B. W. G.) for the heart and N° 13³/, for
the covering as giving perhaps the best results and qualities of strength with
required degree of flexibility for such size of cable.
But I do not desire to be understood as limiting my construction to any precise
difference or proportion between the two grades of wire to be employed for the
inside and the outside of the strand as this depends upon and is governed by the
strength required for the heart and the work to be performed. It being evident,
that to increase the flexibility of the cable it is only necessary to reduce the size
of the wires forming the heart of the strands.
I believe that for cables of medium grade and ordinary work the proportions
herein before given will give satisfactory results.
To produce a cable a number of these strands are twisted together around a
core, C, usually a hempen, and the cable is ready for use.
This improved construction of strand enables me to obtain a smoother surface
for the outside of the heart.
Also to produce a firm close heart of a greater number of wires without
increasing the diameter of the strand and obtain a strong yet flexible strand.
There is therefore less injury to the finer wires or the heart from the rubbing
and abrasive action of the surrounding wires of the covering.
There is also less tendency to crystallize in the finer wires and there is especially
greater flexibility in a strand of this construction than in strands where the heart
is composed of a few number of coarse wires
These characteristics and qualities peculiar to my construction therefore
contribute to the durability of the cable because the increased flexibility renders
the strand better able to sustain the fluxious and tensions received in travelling
around and over pullies and sheaves and other propelling and guiding mechanism,
and because the additional strength and the reduced tendency to crystallization
extends to the life of the heart of the strand.
I am aware that cables adapted for traction purposes have been made with a
soft flexible core or center of hemp both within the strands and in the centre of
the cable.
.
But such strands have comparatively no durability for the reason that the life
or energy of the strand should be located in the center because the outside is
subject to extraordinary compression from the jaws of the gripping devices and
the outside wires are continually being cut and abraded by the grip. I am not
aware however that a cable for propelling and similar purposes has ever been
before produced having a heart of fine wire exceeding seven in number and a cover
or outside protection of heavier wires as herein set forth and described.
Having now described and ascertained the nature of my said invention and in
what manner the same is or may be performed what I claim as secured to me
by the herein before in part recited Letters Patent, is,
A wire strand for the manufacture of wire ropes or cables for propelling purposes,
the heart or center portion of which is composed of finer wires than are employed
to form the outside wrapping or cover.
Also, a wire rope or cable for propelling purposes, formed of a number of twisted
strands wherein the heart or centers of the strands are composed of wires of finer
gauge than the outer wrapping or covering of the strands.
Also, as a new article of manufacture a wire rope or cable for propelling purposes
having the heart or centers of the strands of fine wire and the outside or body of
coarse wire, substantially as described.

page_text: Also, a wire rope or cable having the heart of its strands composed of more than
seven wires of a size or gauge finer than the wires used in the covering or outside
protecting wrapper,
In witness whereof I the said Thomas Seale have hereunto set my hand and
seal this Seventeenth day of May in the year of our Lord one thousand eight
hundred and eighty three.