US1779471A

US1779471A - Wire rope and cable

Info

Publication number: US1779471A
Application number: US335104A
Authority: US
Inventors: Howe James Forrest
Original assignee: American Steel and Wire Company of New Jersey
Current assignee: American Steel and Wire Company of New Jersey
Priority date: 1929-01-25
Filing date: 1929-01-25
Publication date: 1930-10-28
Anticipated expiration: 1947-10-28

Description

Oct. 28, 1930. HOWE 1,779,471

WIRE ROPE AND CABLE Filed Jan. 25, 1929 lnaeiztor:

.ffiMES FOE/67557 Hon 5,

ntented Oct. 28, 193@ UNITED STATES-:-

PATENT OFFICE- JAMES roaassr HOWE, or woncns'rnn,

MASSAOHUSE'ITS, ASSIGNOR Tl) THE AMERI-.

CAN STEEL AND WIRE COMPANY OFNEW JERSEY, ACORPOBATION Oli NEW JERSEY WIRE ROPE AND CABLE Application filed January 25, 1929. Serial No. 335,104.

This invention relates to ropes or cables and, while not limited thereto, relates more particularly to non-spinning ropes.

In various operations it is customary to use a single rope attached directly to the load, and it has been found necessary heretofore even when the so-called non-spinning ropes of the prior art were used, to load the ropes lightly in order to prevent spinning I of the load.

Heretofore so-called non-rotating rope has generally consisted of six strands of one lay' surrounded by twelve strands of the opposite lay, the rotating tendency of the rope being taken care of for light loading by the opposition of the six inner strands versus the twelve outer strands. Since the number of outer strands is materially greater than the number of inner strands, it is obvious that under heavy loading the tendency to rotate is materially increased, because six --strands cannot control the rotating tendency of twelve strands.

The present invention has for its object the provision of a non-spinning rope structure in which the six inner strands will ofiset substantially all the rotating tendency of the twelve outer strands. I

Figure 1 is a perspective view of a piece" at of rope with one end cut away to show the core and the inner series of strands.

Figure 2 is a sectional, view through the rope of Figure 1.

Referring more particularly to the drawas ings the numeral 2 designates the inner se ries of six strands which are wound in one direction over a core 3, and an outer series of strands d is wound about the inner series 2 as a core in the opposite direction. The

l wires which make up each of the individual strands 2 are twisted in the same direction as the lay of the strands, hut in the strands l the individual wires are shown laid in the cppcsite direction-to the lay of the-strands.

l The number of strands in the outer series. are

' twice the number at the inner series. However, since the inner series of strands has the wires as well as the strands all laid in one direction, as sleeve described, this series will 5 hares tendency to untwist very much taster than the outer series of strands which-have the wires laid in the opposite direction than the lay of the strands, thereby counteracting to a degree'the spinning action of the rope. is

In order to further increase the tendency of the inner series of strands to completely counteract the untwisting action of the outer series the wires of the six inner strands preferab-ly' have a greater diameter than the wires of the outer seriesof strands and the wires of the inner strands have a materially greater tensile strength. s

It has been found that when the diameters of the wires comprising the inner strands are sufiiciently larger than the diameter of the wires of the outer strands so that the outer series of strands have an area ratio to the area of the inner series of strands of approximately 63 to 37, and when the tensile strength of the inner series of strands is increased from 10 to 30 per cent. a rope is provided which is substantially non-spinning under all load conditions.

It will, of. course, be understood that I do not wish to be limited to the laying up of the wires of the individual wires of the strands in the manner described above, since the strands may be composedof wires lai up in any usual manner. The lay of the strands is the main controlling factor in the 1 and tensile strength of the inner series of strands are the main features in counteracting this spinning tendency of the rope.

A. true non-spinning rope is one in which the inner and outer series of strands have an equal metallic area so that there is' a complete balance between said series of strands.

' in general commercial practice, however what the art knows and accepts as non-spinning rope is a rope which has oppositely said inner and outer series of strands which are partly balanced so as to resist rota-tine to a material degree under load.

Due to the fact that in general commercial practice a perfectly balanced rope is v seldem if ever made rotatien of the ccinmercial, so-called spinniiw rope under load. The sheet a thereis generall a.

rotation is usually to lengthen the lay on the outside series of strands, and to close the lay on the inside. The result is that a heavier load or excess load is placed on the inner series of strands.

Manufacturers are constantly being called upon-to furnish the so-called non-spinning rope with safety factors of three to four. With the ordinary non-spinning rope construction it will be seen that a slight rotation of the rope will throw enough excess load on the inner series of strands to cause them to fail,

By making the inner series of strands of wires having a greater cross-section and higher tensile strength or even of a higher tensile-strength alone, as described above, the objections to the prior art non-spinning ropes are overcome, since the inner strands will have a greater tendency to oppose the rotation of the outer series of strands and at the same time will have suflicient'excess strength to carry the excess load delivered thereto when the rope rotates under load.

It will, of course, be understood that wires of high tensile strength are harder and have greater resiliency than wires of lesser tensile strength and, therefore, the inner series of strands composed of the higher tensile strength wires will have a greater tendency to oppose the rotation of the outer series of strands than they would if the inner and outer series of strands were composed of 'res ha ing equal tensile strength.

T Vhile l have shown and described a specific embodiment of my invention, it will he derstood that l do not wish to be limited irreto, since various combinations of lay n laying up the wires of the the strands themselves, Various strands may he used to form d various modificazout departing from inre. non defined in the I v s [will said inner series of strands as acore in the opposite direction, said strands each being composed of a plurality of wires, the wires of said inner series 0 strands being of a greater cross-section and resiliency than the Wires of the outer series of strands so as to counteract the rotating tendency of said outer series of strands, and the wires of said inner series of strands also being of a materially higher tensile strength than the wires of said outer series of strands so that they can assume any excess load caused by unwinding of the outer strands.

3. A wire rope composed of an inner series of strands laid up in one direction and an outer series of strands laid up around said inner series of strands as a core in the opposite direction, said strands each being composed of a plurality of wires, the wires of said inner series of strands being of a greater cross-section than the wires of the outer series of strands so that the outer series of strands have an area ratio to the area of the inner series of strands of approximately 63 to37, and the wires of said inner series of strands having a tensile strength of 10 to per cent. greater than the tensile strength of the wires of thefouter series of strands.

In testimony whereof, I have hereunto set my hand.

JAMES FOR-REST HOWE.