US1803912A - Rope structure - Google Patents

Description

H. S. MEARS ROPE STRUCTURE Filed Jam 1929 INVENTOR, /Kfififa BY I ATTORN Patented May 5, 1931 HENRY S. MEARS, OF PORTLAND, OREGON ROPE STRUCTURE Application filed January 15, 1929. Serial No. 332,589.

My invention relates toan improvement in fiber rope, the invention being more specifically applicable to rope used for marine purposes.

Ropes intended for outdoor use, as for example marine ropes, should be made so as not to be affected by moisture to such extent as to become stiff and thus inflexible and hard to handle. This is a common fault in marine rope, due to the fact that in these ropes as ordinarily constructed the yarns are arranged in concentric circles with a relatively high number of turns per lineal unit to each yarn, so that the yarns do not lie closely to gether but rather across one another, thus forming interstices between them in which water collects and causes the fibers to become water-soaked and to swell and harden.

Furthermore, in ropes of this character, especially when wet, which is, of course, the normal condition of service of marine ropes, the yarns being more or less water-soaked and hence stiff and hard tend to resist individual relative adjustment to a bending stress causing the rope tobe very stiff, that is inflexible; and furthermore, since the yarns are hard and stiff they tend to cut and chafe causing the fibers of the rope to wear rapidly, and hence reducing its strength.

I have discovered that in order to prevent the fibers of a rope from becoming watersoaked and chafing and cutting, and thus setting up the said undesirable conditions 1t 1s necessary that the yarns composing the strands be arranged so asto lie close together 7 per lineal. unit, and the strands must be given a relatively greater number of turns in the opposite direction for the same unit; whereby in the finished strand the yarns lying approximately on a circle concentric with the center of, and inscribed by the cira gressively increased towards the circumference of the strand.

These features and the details of construction of my improved rope are hereinafter fully described with reference to the accornpanying drawings.

In the drawings:

Fig. 1 shows diagramatically a strand of my rope the yarns having received their initial number of turns and assembled to form the strand, but before the strand has been twisted in the opposite directions;

Fig. 2 shows the strand of rope similarly to Fig. 1, except that the strand has received its relatively greater number of turns in the opposite direction and illustrates by arrows the resultant relative turns of the yarns; and

Fig. 3 shows diagrammatically a section of rope embodying my invention.

Referring now to the figures, in Fig. l is shown the yarns a theoretically assembled to form a strand 6, the strand being as yet untwisted. The cover yarns (Z are cut away and may be disregarded as being no part of my invention. As will be noted the yarns a; have been given an arbitrary initial number of turns to the left as representedby the arrow A and the strand 6 is to be twisted to the right as indicated by the arrow B. i

In Fig. 2 the strand 7) has been given an arbitrary relatively greater number of turns to the right with the resulting effect on the turns of the yarns as indicated by the arrows.

If a rope made in accordance with my invention be cut across we would find that the following relative arrangement of the yarns in the strand or strands composing the rope:

As shown, the yarns m lying more or less on a concentric circle 6 which divides the area of the strand equally, the fibers are straight, that is, have no twist at all, and the fibers of the yarns y interior of the said circle'e will have turns in the same direction as the strand 6 with the number of turns progressively increased towards the center of the strand, and the fibers of the yarns a said circle will have turns in the opposite direction with the amount of turns progres sively increased towards the circumference ofthe strand.

Such result is attained by thefollowing assumed relative adjustments of the yarns in the strands, in the makingzof the rope.

Let it be assumed that in the making of a rope having a circumference of about six inches, that the initial twist of the yarns was one and'one-halfturns per. foot to the left, andthe twist of; the strand was two turns per foot to the right, and that the relative lengths of'the exterior yarns .2 are approximately two feet for every footof strand, due to the relatively larger spirals formed by the yarns lying at the exterior of the strand.

Similarly the lengths of the'yarns per lineal foot ofthe strand will be relatively less towards the center ofthe strandquntil at the center the yarns 7 are equal in length to-the lineal foot of the strand;

In other words, for every turn put into the strand there will be a corresponding turn put into the yarns forming the'strand; and therefore, since the exterior yarns 2 had" initially one and one-half turns per footto the left and are two feet long, they will have three turns to the left for every foot of strand, and the two turns per foot put in the strand in the opposite direction will reduce the number of turns in the exterior yarns to 1 turn in two feet to the left or one-half turn per foot.

Also, the yarns towards the interior of the strand are progressively shorter so the yarns and having initially one and one-lijal f'turns per foot they willhave only one andon'e-lfalf lying exterior of" V lation,

turns for every foot of strand, and the two turns put in the strand in the opposite direction not only take out the original one and one-half turns to the left, but add one-half turn to the right.

Thus the yarns all lie closely together and side by side with nointerstices between in which moisture may collect to stiffen and harden the fibers, and since none of the yarns cross one another there is no chafing or cutting, or resistance to individual adjustment when the rope is bent: i

The latter being due to the fact that the change in twist of the yarns throughout the strand is-gradualand that while the yarns lie closely together they are not tightly twisted; but lie as a relatively loose homogeneous mass.

I claim 1. A rope having a strandvcomprising a plurality ofyarns twisted together, the yarns lying in the center ofthe strandhaving individual turns in the same direction as the turns-of the strand, and the individual turns of the yarns being less fromthe'centen of the strand'outwarduntiljthe yarns lying on a circle located concentric with and between the center and the circumference of the strand are without turns, lying inparallel relation andthe turns oftlie yarns lying'exterior of said" circle being in the opposite direction and gradually increasing towards the circumference of" the strand fro-mthe yarns lying on the said'circle in parallel re- 2. A rope having a strand comprising a plurality ofyar ns twisted together, the yarns lying in the center of the strandhaving a lesser number of individual turns than the turns of'the strand, but in the same direction, and the indiviual turns of theyarns being less from the center ofthe strand outward until the yarns lying on a circle locatedco-ncentric with and between-the center and the circumference of the strand are withouh turns, lying in parallel relation, and the turns ofthe yarns lying exterior of saidfcircle being'in the opposite direction and gradually increasing towards the circumference of the strand from the yarns lying onthe said circle 1 in parallel relation, andthe number of turns of'the yarns at the center of thestrand and at the circumference being equal, but in the opposite direction. 7 g

3. A rope having a strand comprisinga pluralityv of yarns twisted together, the yarns lying in' the centerof the strand having a lesser number o'fjindividnal turns than the turnsof the strandbut' in the samedirection, and theindividual turns oftheyarn:

beingless from the center of the strandloutwarduntilthe'yarns lying on a circlelocated concentric with" and between" the centerfand the circumference of the strand; and: divid ing the cross sectional" area of the strand m mi) tion.

HENRY S. MEARS.

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