Improvements connected with the Testing of Wire Ropes.
Year: 1892

page_text: Date of Application, 13th Jan., 1892;
Complete Specification Left, 18th Oct., 1892-Accepted, 3rd Dec., 1832
PROVISIONAL SPECIFICATION.
Improvements connected with the Testing of Wire Ropes.
We, WILLIAM CARSON, of The White Cross Company, Limited, Warrington,
in the County of Lancaster, Member of the Institute of Civil Engineers, and THE
WHITE CROSS COMPANY LIMITED, aforesaid, do hereby declare the nature of
this invention to be as follows:-
Hitherto it has been the common practice, in the testing of wire ropes, to hold
the ends in the testing machine, by clamps, which bite onto the outer wire of the
rope, whilst the inner wires are held solely by the friction of the outer wires upon
them, due to the pressure applied through the aforesaid clamps the pull of the
machine being directly applied, to said clamps or clamp holders. Generally these
clamps have a serrated or roughened gripping surface, and are adapted to press
with greater intensity upon the outer wires, as the tension put upon the rope by the
machine, increases. Not infrequently the action upon the wires by the gripping
device, damages such wires, and therefore renders the test untrustworthy. The
tests, however, as ordinarily carried out, are less trustworthy by reason of the
inefficient holding of the inner wires of the rope as above mentioned, namely, solely,
by the friction of the outer wires upon them.
The object of this invention is mainly to obviate the defects above mentioned,
existing in the present mode of securing or holding wire ropes in the testing
machine, or, in other words, to render the tests of wire ropes trustworthy.
According to the present invention, the force or pull of the machine is not
applied directly to the ends of the rope, but such ends are passed partly or wholly
around or about carriers (of cylindrical or other suitable form) and their extremities
secured in a suitable device thereon, whilst the pull or force of the machine is
applied to the carriers, and to such a part of them as will cause the axis of the rope
to lie in, or be practically coincident with, the line of pull of the machine.
The device on the carriers, for holding the ends of the rope, in one form, consists
of a ferrule having a conical hole through it, and the wires at the ends of the rope
are turned or bent back so as to form coned extremities which fit in the coned or
tapered holes of the ferrules.
In one construction or form of carrier, the rope passes round about or other
suitable proportion of a grooved circular device, somewhat in the form of a pulley,
and the axis of that part of the rope lying about said device, as well as the part
between the carriers, lie in the same plane. The part of the carrier which is
attached to the testing machine, is disposed to one side of the point where the rope
leaves the surface of the carrier, as by this means the direction of pull throughout
lies in a straight line.
Dated this 16th dow of January 1802
CHEESBROUGH & ROYSTON, Fels. Chart. Inst. P.A.,
15, Water Street, Liverpool, Applicants' Patent Agents.
COMPLETE SPECIFICATION.
Improvements connected with the Testing of Wire Ropes.
We, WILLIAM CARSON, of The White Cross Company, Limited, Warrington,
in the County of Lancaster, Member of the Institute of Civil Engineers, and THE
WHITE CROSS COMPANY LIMITED, aforesaid, 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:-
Hitherto it has been the common practice, in the testing of wire ropes, to hold

page_text: the ends in the testing machine, by clamps, which bite onto the outer wires of the
rope, whilst the inner wires are held solely by the friction of the outer wires upon
them, due to the pressure applied through the aforesaid clamps, the pull of the
machine being directly applied to said clamps or clamp holders. Generally these
clamps have a serrated or roughened gripping surface, and are adapted to press
with greater intensity upon the outer wires, as the tension put upon the rope by
the machine, increases. Not infrequently the action upon the wires by the
gripping device, damages such wires, and therefore renders the test untrustworthy.
The tests, however, as ordinarily carried out, are less trustworthy by reason of
the inefficient holding of the inner wires of the rope as above mentioned, namely,
solely by the friction of the outer wires upon them.
The object of this invention is mainly to obviate the defects above mentioned,
existing in the present mode of securing or holding wire ropes in the testing
machine, or, in other words, to render the tests of wire ropes trustworthy.
According to the present invention, the force or pull of the machine is not
applied directly to the end of the rope, but such ends are passed partly or
wholly around or about carriers (of cylindrical or other suitable form) and the
end secured in a suitable device on this carrier whilst the pull or force of the
machine is applied to the carriers, and to such a part of them as will cause
the axis of the rope to lie in, or be practically coincident with, the line of pull of
the machine.
•
The device on the carriers, for holding the ends of the rope, in one form,
consists of a ferrule having a conical hole through it, and the wires at the ends of
the rope are turned or bent back so as to form coned extremities which fit in the
coned or tapered hole of the ferrules.
In one construction or form of carrier, the rope passes round about or other
suitable proportion of a grooved circular device somewhat in the form of a pulley,
and the axis of that part of the rope lying about said device, as well as the part
between the carriers, lie in the same plane. The part of the carrier which is
attached to the testing machine, is disposed to one side of the point where the rope
leaves the surface of the carrier, as by this means the direction of pull
throughout lies in a straight line.
The form of carrier last described is shewn in the annexed drawings, for the
purpose of illustrating, by an example, one construction or form of apparatus or
means for carrying out our invention.
In the drawing,
Figure 1 is an elevation, partly in section, and Figure 2 is a cross section.
The carrier consists of a disc a, having at its periphery, flanges b, formed in
the shape of a groove or channel, within which the rope to be tested lies. At one
part of the periphery, the disc is provided with a boss e having a hole through it,
and, at one end of it, with jaws d. These jaws constitute the means by which the
carrier is connected to the testing machine, the connection being effected by a link,
or in any suitable way. Through the hole in the boss e the rope, X, passes, as
will be seen.
"
At another part of the disc, a projection or lug e is formed on the web and
flanges b, and in this projection a ferrule sits. This ferrule is the device by which
the extremity of the rope X is fastened. It will be seen that the ferrule has a
conical hole in it; and in this coned hole the end of the rope is filled out. This
may be done by turning back the ends of the wires forming the outer layers, so
making a conical plugged end, or in any other suitable way.
The centre of the rope X, and the boss and jaws c d, all lie in the same plane, and
therefore all the stresses must take place in the rope and apparatus in the same
plane. And since the centre of the part of the rope X within the boss c, and the
part outside it under the testing stresses, is coincident with the jaws d, and the
direction of pall or tension of the testing machine, no oblique strains take place
when the stresses are transmitted, and a true test is obtained.
To obtain a large amount of holding or gripping effect in that part of the rope

page_text: which lies on the periphery of the carrier, the width of the groove of its periphery
may be made somewhat less than the width or diameter of the ropes to be tested.
This is shewn in the top part of Figure 2.
In attaining this end, it will be observed, the amount of wrapping and turning
of the rope about the carrier is less than a complete circle. It is to be stated,
however, that the invention is not confined to this particular form of carrier, as it
may be done in many ways without departing from the characteristics of the
wrapping or turning of the end of the rope round or about a suitable carrier, and
with any suitable amount of such wrapping or turning, or any number of same; the
extreme end of the rope being suitably fastened to such carrier.
The action or effect of this mode of fastening the ends of ropes for testing
purposes is, that the stresses or strains in the rope at the points of holding same,
are not confined to the actual extremity of the rope at which it is held, which, in
this case, is that part within the ferrule, but are distributed over the whole of the
length of the rope from the extremity, to the point practically, where the rope
leaves the surface of the carrier (that is the boss c); and the amount of the
stresses in the extremity of the rope are therefore much less than in the case of
the rope being held and tested in the usual way. And, since, in the ordinary
arrangement for holding the extremities of test ropes in testing machines, a large
proportion of the inner wires of the rope are not equally and properly gripped or
held, greater stresses come upon the outer wires of the rope than upon the inner
ones, with the result, the rope, in reality is tested and broken in pieces, instead of
as a whole; and what conduces to this is, that these outside wires are damaged by
the excessive stresses and strains to which they are put in the holding device.
Now in this invention the equal and proper gripping or holding of all the wires
of the rope is taken partly by the fastening at the extremity, and partly, by the
contact of the rope with the carrier and by the effect of passing or turning the
rope over a body, as described. By these means, the stresses are distributed
equally through the rope, as far as possible, so that in that part under the full
tension, (namely, the part between the two bosses c of the two carriers) in the
testing machine, each wire takes up its full strain.
By this mode and means it has been found that the breaking strains of wire ropes,
as hitherto ascertained, are misleading and untrustworthy; that is to say, such tests
tended to shew that the breaking strain of a wire rope, as a whole, was far less than
the sum of the breaking strains of the individual wires of which such rope is
composed, whereas we have ascertained that the breaking weight of the whole rope
is not much less than the sum of the breaking weights of the individual wires, and
is far greater than those hitherto ascertained."
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. The improvement described herein connected with the testing of wire ropes,
consisting in holding the ends of such ropes on carriers about which the ends are
turned or wrapped, and applying the tension to the said ropes through said
carriers.
2. The carrier or means for holding the ends of wire ropes for testing same, con-
structed and adapted to act substantially as set forth with reference to the
drawings.
Is 17th day of October 1892.
CHEESBROUGH & ROYSTON, Fels. Chart. Inst. P.A.,
15, Water Street, Liverpool, Applicants' Patent Agents.