US1930661A - Rope - Google Patents

Description

Oct. 17, 1933. w. L. ROCHESTER 1,930,661

ROPE

Filed Aug. 6, 1932 TTE1. l.

W I I awue/wbo'z William L R0c/wser @391 96A W Patented Oct. 17, 1933 UNITED STATES PATENTOFFICE ,ROPE

William L. Rochester, Manhas sett, NJY.

Application August 6, 1932. Serial No. 627,685 1 Claim. (01. 117-52) The invention relates to rope and a method of owing to an excessive shearing action upon the producing same, and with respect to its more covering yarns as they tighten and move against specific features, to strand construction of fiber the core under'strain. rope of large diameter. Referring now to thedrawing, rope according 5 One object of the invention is to provide a to the present invention is composed of a plu- 60 practical and serviceable rope of greater strength rality of strands 10, 10, twisted together. Conin certain large sizes than has heretofore been sidering now the construction of the strands 10, possible according to previous constructions or I take a plurality of slivers or hands 11 of manila by previously known methods of manufacture. fiber, for example, each one of which is relatively 10 Another object of the invention is to provide a soft and loosely laid, that is havingasmall amount 65' rope of great strength which will lie substantially of twist. The slivers or hands 11 are then loosely dead when wet. Another object of the invenstranded together, that is with a small amount tion is to provide a rope which will be free of any of twist, to form the Core By'reason 0f tendency to untwist or rotate whensuspending construction described, this core 12 is relatively 15 heavy weights. Another object of the invention soft. The diameter of the core 12 is preferably 70 is to provide a rope in which internal friction is substantially more than half the total diameter substantially eliminated. Another object of the of the strands 10 of which it forms a part.

invention is to provide a rope which will with-- Still considering the formation of 'a single stand hard usage. Other objects will be in part strand 10, I now cover the core 12 with covering obvious or in part pointed out hereinafter. yarns 13 w i h I la onto the core 12 in a d 75 The invention accordingly consists in the feation opposite to that of the twist or stranding tures of construction, combinations of elements, of the core hands with respect to each other. arrangements of parts, and in the several steps These covering yarns 13 may be yarns of manila and relation and order of each of said steps to fiber and are relatively hardtwisted and have one or more of the others thereof, all as will be great tensile strength. Preferably the twist of illustratively described herein, and the scope of each yarn 13 is opposite to that of the lay of the the application of which will be indicated in the yarns 13 upon the core 12, and preferably the following claim. twist of fibers of the hands 11 is opposite to that In the accompanying drawing, in which is of the lay of the slivers 11 with respect to each 30 shown one of various possible embodiments of other. In the completed strand 10 the covering 85 the mechanical features of this invention, 14 which is composed of the several yarns 13,

Figure 1 is a view in elevation of a piece of completely covers the core 12 and desirably comrope, one end of which has been unraveled, and prises two or more layers of yarns in cross section Figure 2 is a CIOSS-SBOUOIIM View f t rope as shown in Figure 2. The completed rope 15 sh wn in Fi the v al rands being secdesirably consists of three strands 10 twisted tioned in different planes. together in a direction opposite to that of the Similar reference characters refer to similar lay of the covering yarns 14 upon the core 12. parts throughout the several views of the When the rope 15 is put under tension, the drawing. v covering yarns 14 pull against the core 12, but

As conducive to a clear understanding of the shearing action is avoided or reduced to a mini- 95 present invention, I note that the usual rope has mum because of the softness of the core 12. A onsisted of a great number of ends of yarn material factor in increasing the strength of the stranded together to form a strand, a plurality of rope lies in the fact that the core 12, being of strands being then twisted together to form the relatively great diameter, that is to say more rope. Such a rope of usual construction has a than half the diameter of the strand 10, can un- 100 tendency to shrink when wet, kinking and becomdergo a great amount of compression. Another ing very difiicult to handle, especially in the reason why the core 12 can undergo a great larger sizes, such as the heavy rope used for warpamount of compression is that the several hands ing ships at a pier. It has been proposed to make thereof are loosely twisted together. Still anrope of yarns of uniform size, each strand being other reason why the core 12 can undergo a 105 built up of a core laid in one direction and covercomparatively great amount of compression is ing yarns laid in the opposite direction. Rope that it consists of slivers, that is to say fibers made in this manner, however, has been found to that have undergone but a limited number of have lower tensile strength than rope of equal size steps in the manufacture of yarn, for example and grade of yarn of the ordinary construction, fibers that have been carded only. The strength of the core 12 and the covering 14 is nicely balanced by the difference in cross-sectional area thereof.

When ordinary rope is subjected to a breaking strain the inner yarns part first due to their shorter length. By using for the core 12 hands or slivers 11 that are but slightly twisted and are capable of being stretched more than the relatively hard-twisted yarn 141 per unit length, the total stretching capacity of the core is increased to compensate for the greater length of the yarn 14. As a result, when the rope of this invention is placed under a breaking strain, all parts of it reach the elastic limit at substantially the same time, and accordingly the strength of the completed rope 15 for a given diameter is much greater than that of ordinary rope. This I have found to be the fact in practice.

The tendency of rope made according to the present invention to twist and kink upon being wet is slight. Ordinary rope has a tendency to twist when wet, and inthe case of haWsers for ships this is a serious disadvantage when the rope is new. In the construction of the present invention, when the rope is wet, the core 12 tends totwist in one direction, and the covering 14 tends to twist in the opposite direction, and the two strains substantially neutralize each other. At the same time no shearing action is exerted against the covering yarns l4 owing to the softness of the core 12.

It should be understood that in giving my theory of why rope made according to the present explanation now known to me of these facts, the

,made of the mechanical features of the above invention, and as the art herein described might be varied in various parts, all without departing from the scope of the invention, itis to be understood that all matter hereinbefore set forth or shown in the accompanying drawing is to be interpreted as being illustrative and not in a limiting sense.

I claim:

Manila rope comprising three strands twisted together in a given direction, each strand comprising a core and a plurality of yarns laidon the core in an opposite direction of twist, each yarn being hard-twisted in the given direction, the core comprising av plurality of soft twisted hands twisted among themselves with slight twist in .the given direction and the fibers of each hand being twisted together with a slight twist in the opposite direction, the core being soft and'having a diameter greater than half of that of the total strand.

WILLIAM L. ROCHESTER.

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