US3568623A

US3568623A - Towing tackle

Info

Publication number: US3568623A
Application number: US844819A
Authority: US
Inventors: Robert H Gustavson; Bernard Deleman
Original assignee: US Department of Navy
Current assignee: US Department of Navy
Priority date: 1969-07-25
Filing date: 1969-07-25
Publication date: 1971-03-09
Anticipated expiration: 1988-03-09

Abstract

This invention provides an improved piece of towing tackle especially useful in marine towing applications. A slotted skirt device is fitted over the tow line and a hinged wedge stop is clamped about the line and inserted in a recess in the slotted skirt to secure the latter to the tow line. The skirt carries a rotating bearing collar with a towing bail attached thereto.

Description

GR 305689623 5R Robert H. Gustavson Inventors Lynn Haven; Bernard Deleman, Panama City, Fla. Appl. No. 844,819 Filed July 25,1969 Patented Mar. 9, 1971 Assignee the United States of America as represented by the Secretary of the Navy TOWING TACKLE 11 Claims, 7 Drawing Figs.

U.S. Cl 114/235 Int. Cl 1363b 21/00 Field ofSearch 114/235,

[56] References Cited UNITED STATES PATENTS 3,209,718 lO/l965 Rather etal. l14/235(.2F)

3,375,800 4/1968 Coleetal Primary Examiner-Trygve M. Blix Attorneys-Louis A. Miller, Don D. Doty and William T.

Skeer ABSTRACT: This invention provides an improved piece of towing tackle especiE lmffliH'm'afiH'to'wirig'iifiilicationsi Kslb'ii'dliif d6vi'ih'iid'fiveitiie'towflineaiida hinged wedge stop is clamped about the line and inserted in a recess in the slotted skirt to secure the latter to the tow line. The skirt carries a rotating bearing collar with a towing mama thereto ....i. n..r..,,. M-M' PATENTED m 9197! SHEET 1 OF 2 ROBERT H. GUSTNSON 8ERNARD DELE'MAN INVENTORS mam/f PATENTED MAR 9 am SHEET 2 OF 2 mam m4? waw 0,

m M "W M M EN M BR I 0 RM n 1 rowmc TACKLE STATEMENT OF GOVERNMENT INTEREST The invention described herein may be manufactured and 5 BACKGROUND OF THE INVENTION This invention pertains to the field of marine or oceanographic engineering. In particular, the invention pertains to the fields of endeavor where an object is towed aft of a suitable draft vehicle, such as a surface vessel or a low flying aircraft. More particularly, the invention pertains toan improved piece of towing tackle.

In many marine applications, such as fishing or minesweeping operations, it is desirable to tow objects from a cable which is diverted to the side of the tractor vehicle conducting the tow. In many instances it is desired to tow a plurality of objects from a single diverted cable by attaching the objects thereto at intermediate points between the distal and bitter ends thereof. Such attachments are made by securing towing bridles to the diverted cable by suitable tackle carried by the diverted cable at the desired points ther'ealong.

A wide variety of types of prior art tackle have been employed in the past to secure the towing bridles to the diverted wire. In general, the prior art tackle includes links, sheaves, snap hooks,'rope ties, and etc. Those familiar with the prior art will recognize that a great number of possible combinations of these prior art tackle elements may be constructed to constitute the tow assembly. It is not purposed to discuss the limitations specific to each of these combinations of elements, but some general observations concerning prior art limitations are in order to better appreciate the instant invention.

The primary disadvantage to connections made with fixed links is the inability of such devices to be pulled through the sheaves or other line handling gear. This requirespersonnel to be deployed over the side to attach the bridles to the diverted tow line, clearly undesirable in hostile waters and impossible in the case of aircraft tows. Further, the development of the rigid or fixed links to marry the bridle to the diverted cable has resulted in a rather large piece of tackle. The large size is cumbersome to handle, especially when working over the side, and obviously inefficient to tow.

During towing operations, the diverted cable experiences considerable variations in tension loading. These tensional variations are occasioned by the towed apparatus striking objects or altering their drag properties, or by the normal variations caused by the otter used to divert the cable. As will be appreciated by those familiar with marine towing operations, the tensional variations cause a twisting action to occur along the diverted cable. This twisting or torsional movement of the diverted cable causes certain of the towing bridles to wind about the diverted cable. Among the tackle types so affected are the rigid link type, the rope ties, and any other without provisions for isolating longitudinal torsional movement occurring in the diverted cable. The inability to isolate this torsional movement results in additional loading and strain placed on the cable in addition to the obvious tendency to cause fouling of the towing bridles.

In some types of prior art tackle the towing bridles have been secured to the diverted cable by means of a piece of tackle permitting a rotary movement, such as a pulley, to allow the bridle to traverse a short of length of the diverted cable and isolate the aforediscussed torsional movement of the diverted cable. Such devices, however, require two rigid stop members to be placed on theldiverted cable for each tow bridle and thereby cause additional nonconformities along the length of the diverted cable. Too, such tackle arrangements are subject to vibrations and thereby cause additional wear and fatigue on the cable, especially when operating on the surface.

25 It is a further object of this invention to provid the -passage'of said tow cable with the bridle attac e Rope ties and splices, aside from the torsional limitations, are too time consuming to install to make their use practicable where a limited time is available to stream and recover the gear.

Snap hooks, while easily and quickly installed, are limited in their rated load capabilities.

SUMMARY OF THE INVENTION 10 This invention provides a piece of marine tackle, e.g., cable connector or fastener, to be attached to a diverted tow cable which is strong to permit the support of heavy towed loads, is small to permit passage through the normal sheaves and deck rollers thereby permitting shipboard installation and removal,

is designed to be quickly attached and removed, and is designed to isolate torsional movement occurring in the diverted cable fromreaching the towed load support thereby. The invention may be used in other fields where it is desired to join tow cables or wires. The invention also, of course, em-

braces the novel components described in connection therewith and the improved method of operation made possible thereby.

In consideration of the foregoing it is an object of this invention to provide an improved marine towing device.

e an i m d t o is qlfatleft e proved item gf l'llg litle towing t a ckle constructe torsional movemen d e tion ""''A still further ob ect of this invention is the provision of an improved item of marine towing tackle which permits the attachment of towing b ri dle s to a diverted tow cable on shipboard a n d prior to streaming the Yet another object of the present invention is the provision fan improved item ofmarine towing tackle which effectively use tdwiiig bridle divertedtowcable without impairin through conventionaljcab l e hattq 18992? IRE- ""Stillanoth'er object of this invention is the provision of an improved piece of marine tqt ing tacklewhichwillpermit the M 40 c mentotan auxi iary..toflil glillilq3?WEI" w g a aggpgjllt t mediate its extremities with a miniir'ilum expenij diture of ti power.

Oiha bjects an y of tli"attendant advantages will be readily appreciated as the subject invention becomes better understood by reference to the following detailed description,

when considered in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 5 is a bottom elevation of the skirt component of the invention; and

FIGS. 6 and 7 are bottom and end elevations, respectively, of the wedge component of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 1., there is shown, in plan view, a surface vessel 11 which has attached thereto a diverted cable 12. The diversion of cable 12 to one side of the course of vessel ll is accomplished by means of an otter 13 attached at the distal end thereof. Diverted cable 12 is secured at the bitter end so some suitable purchase, not shown, on board vessel 12 to be used in streaming and paying out cable 12. As will be readily apparent to a person versed in the art, such an arrangement is conventional and need not be described in further detail herein.

b it is attac e it should, however, be noted that whereas the invention is herein described as being used in connection with a surface ship it is applicable with other types of tractor vehicles as well. For example, the device may also be used to good advantage with aircraft tow vehicles, particularly rotary wing aircraft.

At intermediate point along diverted cable 12, individual units of towing tackle 14, the subject of this invention, are attached. Attached to each piece of improved towing tackle 14 is a towing bridle 15 which tows a suitable load, are represented by floats 16. It should be understood that floats 16 constitute only an exemplary load and may be replaced by suitable minesweeping gear or fishing apparatus as desired. For purposes of utilitarian completeness, floats 16 may house acoustic or electromagnetic generators for sweeping influence marine mines.

Referring now to FIGS. 2 and 3, the improved towing tackle 14 of the invention is shown attached to diverted cable 12 but devoid of other attaching prior art structure. Such a simplified illustration permits one to readily see that tackle 14 comprises a wedge member 17, a skirt portion 18, a collar 19 and a towing bail 21. These assembled views will enable one to better understand the functions of the individual components as they are described with reference to the remaining F IGS.

Referring to FIG. 4 it is seen that towing bail 21 comprises two identical biflex arms 22 which lie in mutual contact along a first end portion thereof, diverge between their two bends, and are parallel to one another and spaced apart at their other ends, thereby forming a bifurcated assembly. Through their contacting end portions, arms 22 are pierced by a passage 23. Suitable shackle means or threaded fastener means, not shown, secure arms 22 into a unitary assembly. A protruding cylindrical pin 24 is affixed to each of the spaced apart ends of arms 22. Pins 24 are positioned on their respective arms 22 in such a fashion that they are coaxial and face one another across the bifurcated space of towing bail 21 when arms 22 are united.

The contiguous faces of arms 22 may be figured so as to interlock at their first ends, if desired. Such a construction provides additional proof against angular separation about the axis of passage 23. Should such a construction be employed, it is desirable that the interlocking fitting by symmetrical about the longitudinal axis of arms 22 so that they may be identically fashioned thereby reducing the number of different parts that are required to assemble each unit of tackle 14. In practice this has not been necessary for the normal surface or shallow tows, however, for pelagic tows such additional dimensional stability may be desirable.

Still referring to FIG. 4, collar 19 is seen to comprise two hingedly joined semicylindrical segments 25 26. The two

segments

25 and 26 are fastened by a hinge pin 27 about which they rotate. Hinge pin 17 may be a loose or finger fit or it may be secured to one of the segments.

Segments

25 and 26 meet at a common interface which, like the first ends of arms 22, may be figured, if desired. A suitable threaded fastener 28 secures

segments

25 and 26 together about a cylindrical axial aperture having an inwardly facing bearing surface 29. A recess 31 in segment 26 provides access to the tool engaging end of fastener 28 while a threaded hole 32 provides suitable engagement with the threaded end thereof. Diametrically opposed, coaxial cylindrical apertures 33 extend through

segments

25 and 26 and receive pins 24 therewithin to permit assembled towing bail 21 to be supported for pendulous movement about collar 19.

Skirt portion 18 is illustrated in detail at FIG. 5. A slot 34 extends the length of the skirt portion 18 and communicates with a cylindrical axial bore 35. As may be seen in FIG. 3, the width of slot 34 and diameter of bore 35 are chosen to be approximately the same dimension as the diameter of diverted cable 12.

At the forward end of skirt portion 18, a cylindrical bearing surface 36 is flanked by two transverse circumferential lands 37. The diameter of bearing surface 36 is chosen so as to provide a bearing contact with bearing surface 29 of collar 19. The height of lands 37 relative to bearing surface 36 is chosen such that it is in excess of the distance between bearing surface 29 and hinge pin 27 ofcollar 19.

A hollow pocket 38 is located in the aft end of skirt portion 18. Pocket 38 is generally shaped as the frustum of a cone with the apex end forward most. The forward end of pocket 38 is radiused into cylindrical bore 35 to provide a smooth transition from one surface to the other. Skirt portion 18 has, at the aft end, a flared wall 39, so as to provide a uniformly strong wall for pocket 38.

Referring to FIGS. 6 and 7, the details of the construction of wedge member 17 will now be described. Like collar 19, wedge member 17 is comprised by two hinged

wedge segments

41 and 42.

Segments

41 and 42 are joined by a hinge pin 43 to pivot thereabout. Pin 43 may be advantageously peened or otherwise made fast to segment 41 to form, when assembled to segment 42, a unitary structure.

Segments

41 and 42 are shaped so as to provide, when closed, an elliptical passage 44 extending through the entire length of wedge member 17. The major transverse axis of passage 44 is of the same magnitude as the diameter of diverted cable 12, while the minor axis is somewhat less. The outer surface of wedge 17 has a protruberant ridge 45 which partially surrounds pin 43. Except for the surface irregularity presented by ridge 45, wedge member 17 is of the shape of the frustum of a cone, having the same slope as pocket 38 but of somewhat larger dimensions.

The individual parts may be made of any suitable material suitable for exposure to the harsh environmental conditions to which marine tackle is commonly exposed. Good results have been experienced by making wedge member 17 of a relative soft metal, such as bronze, so as to not damage cable 12, and the remaining components of stainless steel. Surfaces 29 and 36 may be treated to improve their bearing properties as by coating with suitable materials to improve their cooperation, as will be made clear in connection with the description of the mode of operation of the preferred embodiment. In practice, however, the stainless steel from which each has been made performs satisfactorily when lubricated with sea water.

The foregoing description of the component parts is, of course, subject to modification within the normal recognized range of mechanical equivalents. Such changes may be incorporated at the discretion of the proficient artisan, providing that they do not alter the cooperation of the individual elements. As an example of such envisioned modification, fastener 28 might be secured to segment 26 by a circumferential groove in the shank thereof cooperating with a fixed pin in segment 26. As will be better appreciated in connection with the reading of the mode of operation of the preferred embodiment, such departures from the aforedescribed exemplary embodiment does not alter the cooperation of the individual elements or impair their individual performance.

MODE OF OPERATION The operation of applicants invention departs from the prior art streaming and recovery of towed gear in the fashion that towing bridle 15 is joined to diverted cable 12 and the location at which the attachment is normally made. Both of the differences are directly attributable to applicants improved device and constitute profound improvements belying the simplicity of construction of the device making them possible.

When it is desired to stream gear from vessel 11, diverted cable 12 is payed out from a suitable storage reel or drum and attached, outboard of the deck handling sheaves, rollers, or other cable handling and guiding apparatus. Cable 12 is payed out until the position at which it is desired to attached the outermost towing bridle 15 is positioned at a convenient working position on the deck of vessel 11.

The attachment of bridle 15 to diverted cable 12 begins by prepositioning bridle 15 outboard of the vessel 11 and back through the cable guiding apparatus, so as to lie alongside of diverted cable 12. When diverted cable 12 is stopped with the attachment point positioned at a convenient work station, as

noted above, wedge member 17 is placed on cable 12 with the small end forward and then closed about cable 12. Skirt portion 18 is then placed on diverted cable 12 forward of wedge member 17 by passing cable 12 through slot 34 until it fits within bore 35. Skirt portion 18 is fitted with the aft end with pocket 38 facing the small end of wedge member 17 with ridge 415 aligned with slot 34 and driven aft thereupon to close wedge member 17 on cable 12. Because of the size of the minor axis of elliptical passage 44, wedge member 17 then grips cable 12 tightly as a result of the closing action of pocket 3 on wedge member 17. The frictional fit between wedge member 17 and skirt 18 together with the interference fit between ridge 45 and slot 34 result in skirt potion 18 being torsionally coupled to diverted cable 12.

Collar 19 is placed about skirt portion 18 between lands 37 with bearing surfaces 29 and 36 in contact. Fastener 28 is tightened to secure collar 19 about skirt portion 18; When tightened in position there is still clearance to permit relative sliding rotation between skirt portion 18 and collar 19. This freedom of movement permits the torsionally introduced movement of diverted cable 12 from being transmitted to towed float 16 or other towed apparatus. Pin 27 is retained, where it is a loose fit, by lands 37.

Arms 22 are positioned with pins 24 inserted into aperture 33. The assembly of towing bail 21 and collar 19 is made rigid by passing a suitable fastener, which may be a part of towing bridle 15, through aligned passages 23.

Additional length of cable lZ'is then payed out until the position where a second bridle is desired to be fastened is positioned over the working position on the deck of vessel 11 and the attachment steps are repeated.

As line 12 is payed out the towing tackle 14 of the invention passes throughthe cable handling apparatus carrying with it towing bridle 15. The hydrodynamic drag caused by towing float 16 causes skirt portion 18 to be pulled back on wedge member 17 to effect an increased griping action on cable 12.

Upon recovery, disassembly proceedswith a reversal of the steps used in attachment. A blow with a mallet or other appropriate tool will generally suffice to free skirt portion 18 from wedge member 17. After disassembly the component parts of towing tackle 14 may be conveniently stored aboard vessel 1 1.

From the foregoing description it may be readily seen that applicants have produced an improved piece of towing tackle which performs in an improved fashion to meet the objects of invention. Further, that this device, although of simple construction, was unknown prior to the disclosure herein presented and, accordingly unobvious to a person familiar with the pertinent technical fields encompassed thereby. However, the foregoing disclosure taken together with the appended drawings and claims constitutes a disclosure sufficient to permit such an artisan to make and use the device and to perform the improved method of marine towing made possible thereby.

. Weclaim:

1. An improved towing tackle for attaching a pendant line ,or towing bridle to a diverted tow cable comprising in comination:

, wedge means for gripping said diverted cable; 2 skirt means adapted for fitting about said diverted cable and enclosing said wedge means, so as to close it upon said cable and be supportedthereby; collar means rotatably supported by said skirt means so as to be independent of motion of said skirt means arising from torsional forces within said diverted cable; and towing bail means supported by said collar means and attached thereto for pendulous movement relative thereto and adapted to receive said towing bridle or pendant line. 2. An improved towing tackle according to claim 1 in which said towing bail'comprises two identical biflex arms with collar means engaging pins on one end thereof and an aperture on the other end for engaging said towing bridle.

3. An improved towing tackle according to claim I in which said wedge means is made of a material having a hardness less than that of said diverted cable.

4. An improved towing tackle according to claim 1 in which said wedge means comprises two segments hingedly secured together to form a frustoconical body portion.

5. An improved towing tackle according to claim 4 in which said wedge segments, when closed, enclose an elliptically cross-sectional passage having a major axis of the same length as the diameter of said diverted cable.

6. An improved towing tackle according to claim 1 in which said skirt means includes a longitudinal slot communicating with a central bore each being slightly larger in width than the diameter of said diverted cable.

7. An'improved towing tackle according to claim 6 in which said central bore communicate with a coaxial pocket of frustoconical shape located in the aft end thereof and positioned with the frustum face facing forward.

8. An improved towing tackle according to claim 6 in which said skirt means has at its forward end two raised lands extending laterally and circumferentially about said skirt means and spaced longitudinally from each other with an outwardly cylindrically shaped bearing surface extending therebetween.

9. An improved towing tackle according to claim 1 in which said collar means comprises two hinged, semicircular segments joined together at one-side thereof by a hinge pin and at the other side by a mechanical fastener.

10. An improved towing tackle according to claim 9 in which said semicircular segments enclose an internally facing, cylindrical bearing surface.

11. An improved towing tackle for joining a towing bridle of a pendant'tow to a diverted tow cable comprising in combination:

wedge means comprising two interfitting segments made of a softer material than that of said diverted tow cable and shaped so as to form a frustoconical wedge with an elliptical passage therethrough when interfitted; first hinge means joining said segments together as a unitary assembly and lying in a longitudinally extending ridge along the surface of said frustoconical wedge, so as to permit said wedge to be-closed about said diverted cable in gripping engagement therewith; skirt means having a frustoconically shaped pocket extending from one end thereinto and shaped to be complementary to the shape of said wedge means and communicating with an axially extending bore piercing said skirt means longitudinally to the opposite end thereof, both said bore and said pocket communicating to the lateral surface via a longitudinally extending slot of suitable dimensions to permit the skirt means to be placed over said diverted cable and positioned to receive said wedge means within said pocket with said ridge extending into said slot for preventing relative rotation therebetween;

cylindrical bearing surface means carried by said skirt means at said other end thereof and facing outwardly therefrom; two land means supported by said skirt means and extending outwardly therefrom on either side of said cylindrical bearing surface so as to provide stop means on either side thereof;

collar means comprising two segments located between said two land means having a centrally facing bearing surface cooperating with said cylindrical bearing surface means for rotation of said collar about the longitudinal axis of said skirt means;

second hinge means joining said collar segments to make a unitary structure thereof and located at least partially in the space located between said land means, so as to be longitudinally positioned thereby and effective to permit said collar means to be removably mounted on said skirt means;

fastener means for securing said collar segments together in position about said skirt means;

said arms thereby and aligned passage means in the other end of each of said arms for receipt of suitable fastener means to secure said arms together to form a unitary structure and for support of a towed load thereby.

Claims

1. An improved towing tackle for attaching a pendant line or towing bridle to a diverted tow cable comprising in combination: wedge means for gripping said diverted cable; skirt means adapted for fitting about said diverted cable and enclosing said wedge means, so as to close it upon said cable and be supported thereby; collar means rotatably supported by said skirt means so as to be independent of motion of said skirt means arising from torsional forces within said diverted cable; and towing bail means supported by said collar means and attached thereto for pendulous movement relative thereto and adapted to receive said towing bridle or pendant line.

2. An improved towing tackle according to claim 1 in which said towing bail comprises two identical biflex arms with collar means engaging pins on one end thereof and an aperture on the other end for engaging said towing bridle.

3. An improved towing tackle according to claim 1 in which said wedge means is made of a material having a hardness less than that of said diverted cable.

7. An improved towing tackle according to claim 6 in which said central bore communicate with a coaxial pocket of frustoconical shape located in the aft end thereof and positioned with the frustum face facing forward.

9. An improved towing tackle according to claim 1 in which said collar means comprises two hinged, semicircular segments joined together at one side thereof by a hinge pin and at the other side by a mechanical fastener.

11. An improved towing tackle for joining a towing bridle of a pendant tow to a diverted tow cable comprising in combination: wedge means comprising two interfitting segments made of a softer material than that of said diverted tow cable and shaped so as to form a frustoconical wedge with an elliptical passage therethrough when interfitted; first hinge means joining said segments together as a unitary assembly and lying in a longitudinally extending ridge along the surface of said frustoconical wedge, so as to permit said wedge to be closed about said diverted cable in gripping engagement therewith; skirt means having a frustoconically shaped pocket extending from one end thereinto and shaped to be complementary to the shape of said wedge means and communicating with an axially extending bore piercing said skirt means longitudinally to the opposite end thereof, both said bore and said pocket communicating to the lateral surface via a longitudinally extending slot of suitable dimensions to permit the skirt means to be placed over said diverted cable and positioned to receive said wedge means within said pocket with said ridge extending into said slot for preventing relative rotation therebetween; cylindrical bearinG surface means carried by said skirt means at said other end thereof and facing outwardly therefrom; two land means supported by said skirt means and extending outwardly therefrom on either side of said cylindrical bearing surface so as to provide stop means on either side thereof; collar means comprising two segments located between said two land means having a centrally facing bearing surface cooperating with said cylindrical bearing surface means for rotation of said collar about the longitudinal axis of said skirt means; second hinge means joining said collar segments to make a unitary structure thereof and located at least partially in the space located between said land means, so as to be longitudinally positioned thereby and effective to permit said collar means to be removably mounted on said skirt means; fastener means for securing said collar segments together in position about said skirt means; aperture means extending diametrically through said collar means, so as to provide mounting surfaces thereon; and towing bail means comprising two identical biflex arms having a pin mounted on one end of each of said arms and extending into said aperture means for pendulous support of said arms thereby and aligned passage means in the other end of each of said arms for receipt of suitable fastener means to secure said arms together to form a unitary structure and for support of a towed load thereby.