US 3195299 A
Description (OCR text may contain errors)
July 20, 1965 A. DlETz 3,195,299
WIRE ROPE Filed oct. 25, 1962 /Nvf/vra/e ALFRED Dl ETZ i BY A-r'r RNEY United States Patent O 3,195,299 WIRE RPE Alt'rcd Dietz, Damaschkestrasse 30, Neustadt, near Coburg, Germany Filed Oct. 23, 1962, Ser. No. 232,523
Claims priority, application Germany, .lune 6, 1962,
7 Claims. (Cl. 57-149) This invention relates to wire rope.
There are many known proposals for improving wire rope by making use of rubber or synthetic plastic materials.
As far as concerns the known measure of embedding the rope element i.e. Wires or strands individually in the aforesaid materials, the products obtained have limited working capacity or strength, since with certain rope dimensions the load-supporting metal cross-section is greatly reduced. Therefore, such constructions can only be used in special cases, especially since relatively considerable forces effective in the rope crush the rubber or the like.
For protection against corrosion, on the other hand, the possibility has been considered of enveloping a normally constructed rope with a synthetic plastic material jacket. However, if this jacket is arranged in the manner of a flexible tube on the rope, the said jacket becomes unusable since in the course of the rope working over pulleys the jacket tends to wrinkle and becomes cracked.
The present invention provides a Wire rope differing substantially from, but which can have some features in common with, the wire rope structures disclosed in my copending applications, Serial No. 70,160, led November 18, 1960, and Serial No. 192,156, tiled May 3, 1962, which applications were issued as United States Patent Nos. 3,131,530 and 3,154,910 on May 5, 1964, and November 3, 1964, respectively.
The invention relates to wire ropes wherein synthetic plastic material is used although from different considerations than those obtaining hitherto. It proceeds from the fact that the chief reason for the destruction of the rope structure resides in the high pressures per unit of surface area which occur not only between the wires or strands of the rope but also between the outer elements of moved ropes and their guide pulleys. The round cross-section of the ropes and wires leads unavoidably to the contact zones between adjoining parts being punctiform or at the most linear in form, and this leads to abrasion, notching, ilattening, etc.
In order to obviate these disadvantages, the invention proposes working into the natural gaps between the outer elements of the rope synthetic plastic material iillings which, preferably without any adhesive connection to the said elements, are bounded by a cylindrical generated surface corresponding to the rope diameter.
The consequence of this construction is that the rope is supported over its entire periphery in the guide pulleys and therefore is not stressed at specic places. At the same time, the llings between the outer elements have the result that these do not contact one another under tensile stressing, and therefore also could not be displaced radially inwardly with reduction of the rope diameter, which would have the undesirable result of subjecting the inner elements to a clamping eifect. The invention, therefore, considerably improves the mechani- Cal working ability of the rope, especially since the use of the novel principle does not require any change in the normal rope constructions, and does not cause any loss in metal crossesection in the rope.
lb Patented July 20, 1965 "ice Since wire ropes are in any case so constructed that their outer elements do not contact one another as f ar as possible, the natural gaps between these elements more particularly strands, will generally be sufficient to obtain a flush introduction of the plastic fillings, preferably made ot polyamides. But since it is advantageous to take the plastic fillings beyond the centre circle of the outer elements of the rope so far into the interior of the rope that they engage behind the outer elements, it may be convenient to cable the outer elements so that they -have small spacings from one another.
If the plastic fillings are made to engage beyond the centre circle between the outer elements in the manner already described, they can readily be extended inwardly so far, without changing the normal rope, that they extend through between the outer elements as far as the rope elements which follow the said outer elements, and if necessary partly surround the said inner elements.
It has also generally been found advantageous to introduce the synthetic plastic material under pressure in Such a manner that it engages laterally in the gaps between the wires of the outer strands, since this anchors the fillings in a particularly secure manner.
Since it is not the object of the invention to cover the wire rope, the synthetic plastic material is to terminate externally at a cylindrical generated surface which corresponds to the diameter of the rope and which, accordingly, adjoins tangentially the outer elements of the rope.
In practice, however, it will be unavoidable that when applying the synthetic plastic material the synthetic plastic material will here and there run in a thin layer over the apexes of the outer elements, especially if the rope is not exactly circular. Similarly, the synthetic plastic material may sometimes terminate slightly below the apex of the outer elements. However, experience has shown that the aforesaid inaccuracies rapidly become evened out during rope working.
The rope construction as such is not important to the essence of the invention. The novel plastic fillings always keep the inner regions of the rope permanently free of radial pressures.
Whereas in known arrangements of wire ropes with a rubber matrix an adhesive connection between metal and rubber is chosen, this adhesive connection between rubber and metal is generally avoided with the subject of the present invention in order not to interfere with the inherent movements of the rope elements, particularly when running over pulleys, and thus in order not to inuence detrimentally the mechanics of the rope structure.
One embodiment of the invention is illustrated in the drawing, which shows a cross-section through a rope according to such embodiment.
The illustrated rope comprises a core strand 1 (1+6 wires), and inner layer 2 of strands (strands of 1-l-6 wires) and an outer layer 3 of strands (7 parallel lay strands comprising core wire and 12 inner and 12 outer wires).
Introduced into the gaps 4, 5, 6, etc., between the outer strands are llings '7, 8, 9 of synthetic plastic material of great hardness and toughness, in such a manner that they are bounded externally by the generated surface 10 deining the rope cross-section, whereas they extend radially inwards beyond the centre circle 11 of the outer strands and thus are extremely effectively anchored. It will also be seen, for example at 12, 13, 14 that the synthetic plastic material also projects into the gaps between the outer wires of the outer strands, and is thereby additionally anchored.
As further indicated in the drawing, for example at 15 and 16, the illings of hard tough plastic material may extend inwardly into the rope so far that they engage the outermost wires `of the strands of the inner layer 2, but not so far as to lie radially beneath the outer strands. Eachprlling thus has a cross-section of dovetailed shape with'the inner portion of its body wedged, inside the circle 11, between confronting inner side portions of adjacent strands of the outer layer 3 and between those portions and the outermost wires of a strand of the inner layer 2.
Although, particularly if ,the rope is not exactly circular, it may be that for example the synthetic plastic material will at rst slightly cover one or other outer strand, for example in the form of a thin skinl of plastic material, the ropeadjusts itself in such a manner during use that the peripheral line of the rope bounds both the synthetic plastic material and the outer strands.
The underlying idea of the invention can also be applied analogously-to component strands of ropes.
1. A stranded wire rope comprising inner wire rope elements overlaid by a circumferential .series ofV outer` helical Wire strands spacedapart inparallel lay, and 'lillings of a hard tough synthetic plastic material extending radially in the spaces between said outer strands and holding said strands laterally separated one from another, said llings terminating at their outer side substantially at the peripheral outline of said series, and being separate at their inner sides and there terminating away from the radially innermost surfaces of said strands, and being suiciently hard andtough that they keep said strands from contacting one another laterally and limit the radial pressure of said strands upon saidinner elements when the rope is under strain.
2. A stranded wire rope according to claim l, said fillings having no adhesive connection to said strands spaced apart in parallel lay.
3. A stranded wire rope comprising inner wirerope elements overlaid by a circumferential series ofV outer helical wire strands spaced apart in parallel lay, and iillings of a polyamide resin extending radially in the spaces;- between said outer strands and holdingrsaid strands laterally separated one from another, said fillings termin-ating at their outer side substantially at the peripheral outline of said series, and being separate at their inner sides and there terminating away from the radially innermost surfaces of said strands, and being suiciently hard and tough that they keep said strands from contacting one another laterally and limit the radial pressure of said strands upon said inner elements when the ropeis under strain;
4. A stranded wire rope comprising inner wire ropeY elements overlaid by a circumferential series of outerv I of outer helical wire strands spaced apart in parallel lay,
and illings of a hard tough synthetic plastic material, each of substantially dovetailed cross-section, extending radially in the spaces between said outer strands and holding said outer `strands laterally separated one from another, said llings terminating at their outer side substantially at the peripheral outline of said series and extending inwardly in wedging engagement with confronting side portions of said outer strands inside the center line of said series and into engagementwith the outermost wires only of the strands of said inner layer, said fillings being separate at their inner sides and there terminating away from the radially innermost surfaces of said outer strands, and being sufciently hard and tough that they keep said strands from contactingY one another laterally and limit the radial'pressure of said outer strands upon said inner elements when the rope is under strain.
6. A stranded wire rope comprising inner wire rope elements overlaid by a circumferential series of outer helical wire strands wound thereupon in parallel lay with small `spacings left between said strands, and llings of a hard tough-synthetic plastic material, each of substantially dovetail cross-section, molded into said spacings and holding said strands laterally/,separated one from another, said llings terminating at their outer side substantially at the peripheral outline of said series and extending inwardly in wedging engagement with confronting side portions of'said strands insidey the center line of said series, and being separate at their inner sides and there terminating away from the radially innermost surfaces of said strands, and being suciently hard and tough that they keep said strands from contacting one another laterally and limit-the radial vpressure of Vsaid outer strands upon said inner elements when theV rope is under strain, the outermost surfaces of said fillings deining a substantially cylindrical rope surface substantially tangent to the outermost surfaces of said strands.
'7. A standard wire rope accordingto claim: 1,-said lillings having portions thereof engaging laterally in gaps between wires forming confronting sides of said strands.
References Cited by the Examiner UNITED STATES PATENTS 396,130 i 1/89 l Willoughby 57-153 1,055,326 3/13 Gore 57-149 2,067,405 1/37 VMayne 57-149 3,064,414 v11/62 Andoy 57-153 X 3,131,530 5/64 Dietz 57-149 3,154,910 `11/64 Dietz, 57-149 FOREIGN PATENTS 188,641 3/05- Germany.
MERVIN STEIN, Primary Examiner. RUSSELL C. MADER, Examiner.