US3132436A - Expander ring for trawl nets - Google Patents

Description

y 12, 1954 F. J. LUKETA EXPANDER RING FOR TRAWL NETS 4 Sheets-Sheet 1 Filed Feb. 18, 1963 INVENTOR. Fem/K cl dar/h BY 7? C i iliuwam A from/6M1 May 12, 1964 LUKETA 3,132,436

EXPANDER RING FOR TRAWL NETS Filed Feb. 18, 1963 4 Sheets-Sheet 2 INVENTOR. FRANK J AMA 67A May 12, 1964 F. J. LUKETA EXPANDER RING FOR TRAWL. NETS 4 Sheets-Sheet 3 Filed Feb. 18, 1963 INVENTOR. FRANK J AH BY fi mqca, M 9

A rrOEA H May 12, 1964 I F. J. LUKETA EXPANDER RING FOR TRAWL NETS Filed Feb. 18, 1963 4 Sheets-Sheet 4 INVENTOR. FRANK J AHA/774 ,4 TTOFA/fy United States Patent 3,132,436 EXPANDER RING FOR TRAWI. NETS Frank .1. Lulreta, 5567 Greenwood Ave., Seattle 3, Wash.

Filed Feb. 18, 1963, Ser. No. 259,155

12 Claims. (Cl. 43-9) This invention relates to generally the same subject matter as my copending companion application of the same title, bearing Serial No. 259,154, and filed February 18, 1963.

As is explained in said application Serial No. 259,154, the mesh at the entrance to the codend of a trawl net must be held sufficiently open that it will not close down to the extent to block entrance of fish. The constriction is due to longitudinal stress upon the meshes, in use, which causes them to close down circumferentially. The solution heretofore proposed has been to incorporate a rigid expander ring at the entrance to the codend, as disclosed and claimed in my application Serial No. 85,662, filed January 30, 1961. The earlier proposed solution will accomplish the end in View, but it presents a large, bulky mass which cannot readily be wound upon a drum, according to the drum trawling method now in common use, hence can be used only by crawlers sufiiciently large that .the codend can be deposited on deck without winding its entrance about a drum. Few present-day trawlers of United States registry are so large.

The solution proposed by my said companion application, Serial No. 259,154 and herein, is to fix a series of beads to the mesh, so as to define acircle in the vicinity of the entrance to the codend, the affixation being accomplished while the mesh is relaxed, and being at such close spacings that when the mesh is elongated in use, and so is constricted .circumferentially, the beads will come substantially into contact, thereby limiting the constriction and holding open the entrance, the. beads mutually supporting one another in a generally circular ring. Nevertheless, when wound upon a drum the circle is'collapsed, and the obstruction to winding on the codend largely'disappears. a When the net is reset the. relaxed mesh, and the ring again expand. v

1 According to the disclosure in my said application Serial No. 259,154, the beads when assembled in operative relation to themesh were of one-piece formation, al-

though some engage two points where'bars of the mesh crossed. This imposes some restriction on elongation of the mesh at such points. It is the primary object of this invention to form the beads sothat they can themselves elongate in such circumstances, and so will impose substantially no restriction to elongation of themesh, nor stress upon the mesh due to failure of the beads to elongate.

Such elongatable beads are formed of two or more sections, relatively movable. It. is a. further object to form the sections in Such manner that each one will always remain in agiven location with respect to a square of the mesh, or to the crossing of two bars of the mesh to which it is secured, regardless of elongtationthat may vary the distance between the squares or crossings .to which other sections of the same bead may be secured.

The'solution proposed by my said companion application Serial No. 259,154, and in'another companion application Serial No. 259,150, filed February 18, 1963, and

In the inventions disclosed in said application Serial Nos. 259,154 and 259,150, it is also an object to form the beads inseparable but identical halves, and the bearing the same title, is to fix a series of beads ,to the mesh. 65.

halves of individual sections likewiseidentical, whereby they may be molded in a common mold, for economy and simplicity.

The beads in the forms shown in said applications 259,-

154 and 259,150 still constitute some unwanted bulls, and

3,132,436 Patented May 12, 1964 2 each bead is wholly independent of all other beads, and

must be individually and carefully fixed in position. It IS an object of the present invention to form the beads largely in the flat, of rubber or like elastic material, or in "flexible for constriction orexpansion as the separate and somewhat bulkier beads of the two previously mentioned applications.

It is also an object of the present invention to provide beads in such form and so fixed to the mesh that'they are not aifected by elongation of the mesh when stressed.

It is a further object of the present invention to form such strin s of beads in two halves, each formed in the same mold, if desired, for economy and convenience.

With these and other objects in mind, as will appear hereinafter, the present invention relates to the improved forms shown ierein, anddescribed in detail'and claimed hereinafter.

FIGURE 1' is an isometric view, partly broken away, of a bottom trawl net such be applied to.

FIGURE 2 is an isometric exploded View, showing the bead strings according to one form of this invention in the process of being applied to the mesh.

FIGURE 3 is an edge view of the string of beads applied to the mesh, and partly broken away in section.

of a slightly modified modified form, in relaxed and in stressedshapes, respectivesl, and FIGURES 9 and 10 are sections through such forms (though without pleats), when relaxed and when stressed, respectively.

FIGURE 11 is a plan view of a further modified form, with the mesh relaxed, and FIGURE 12 is a like View with the mesh elongated.

FIGURE 13 is anedge view of the same, partly in section.

FIGURE 14 is an isometric view of one of the component elements of the last-mentioned form, and FIG- URE 15 is a like View of a slight further modification thereof. v

FIGURE'ldis a plan view, similar to FIGURE 11, of a form resembling but modified slightly from the form of the latter'figure; FIGURE 17 is a plan view thereof similar toFIGURE 12; FIGURE 18 is an edge view similar to FIGURE 13; and FIGURE 191's an exploded isometric view, somewhat similar to FIGURES 14 and15.

Referring'first to thegeneral view, FIGURE 1, the net is illustrated as a bottomftrawl net, although the 'inas the present invention can ventionjis applicable also to a midwater trawl net. As

shown .it cornprises a codend 9 o fmesh, a funnel 8 of mesh converging aft and leading to the open entrance to the 'codend, and curtains 7 diverging forwardly from the joined at to the forward side edges upperbosom 81 and of the funnel. Sweep lines 7 S2 diverge forwardly from the opposite ends of the lower bosom 83 to. doors .5 at

the opposite sides of and ahead of'the net, and curtain:

lines 70, whereonthe curtains'hang, diverge forwardly ends aregathered to a point. The sweep lines 82 are from the opposite endsgof the upper bosom to the doors. Towing-warpsStl from the trawler (not shown) 'tow the anchored at such points to the respective suspenders 2, and transmit the drag to the codend through the suspenders. These suspenders tend to constrict circumferentially under longitudinal stress, and this tendency is transmitted to the codend at its entrance.

In essence the present invention employs a mesh element which encircles and defines the entrance to the codend, which mesh is so oriented that it is elongatable under stress, and thereby is constricted circumferentially. Such mesh element may be the mesh of the codend or of the funnel. In the absence of an expander ring or its equivalent, the constriction might progress until the entrance is effectively closed, and fish gathered in the funnel could not enter and would eventually escape. By this invention beads are secured to the mesh while relaxed, but at sufficiently close spacings circumferentially that when the mesh is elongated under the normal stresses of use the beads come at least approximately into contact, and by substantial interengagement limit the circumferential constriction and hold the entrance open sufficiently so that fish can always enter. Nevertheless, when the circle of heads is subjected to diametrally rather than circumferentially applied force, it will collapse. Such a diametrally applied force results from the flattening effect of the mesh as it is wound upon a drum, and as subsequent windings press the mesh towards the drum, as explained more fully hereinafter.

The expander ring is shown as supported by the mesh, whether of the codend or of the funnel is immaterial, but somewhere in the vicinity of the line 98, where the funnel joins the codend. The expander ring consists of a circle of beads 1 joined by resiliently flexible elements 2 which are integral with certain or all of the beads, the beads and their connecting elements being supported upon the mesh, while that mesh is relaxed, at such close intervals circumferentially-determined by the connecting elements-that when lateral or circumferential constriction of the mesh draws them closely together, they come approximately into contact. This limits the constriction and renders them mutually self-supporting in the round form, as seen for example in FIGURES 5, l2, and 17. The exact form of the ring of beads, or the exact shape of individual beads 1, and the manner in which or upon the mesh of what net element they are mounted, are not material in the broad sense, yet the forms shown are convenient, and enable individual beads, in at least one form, or the entire ring in other forms, to be mounted or dismounted readily, and to be made inexpensively by molding procedures.

The beads 1 according to the present invention take the form of flat disks, some forms of which are divided into halves at a plane parallel to the plane occupied by the mesh. One-half of each bead might be disposed interiorly of the mesh and the other half exteriorly thereof, but both halves can be disposed at one surface of the mesh, and are so shown in FIGURES 2, 4, 5, l6 and 17. To distinguish them the interior half is designated 11a and the exterior half 11b. The two halves are joined, and each bead is fixed relative to the mesh, by such means as screws 13, usually four in number, disposed to straddle each of two bars of the mesh where they cross at a point of the mesh, thereby effectively locating the head for movement with that point. Where the bead halves are not disposed at the opposite surfaces of the mesh, or where the bead is not divided into halves, as in FIG- URE 6, a washer It: is applied to the mesh surface opposite that surface to which the beads are applied, and receives the ends of the screws 13. Each washer has outstanding bosses 14, received in some cases in complemental sockets 15 in the beads, which sockets in some cases serve to countersink the screw heads 13.

The beads can be conveniently molded of rubber, nylon, polypropylene, or like material which is elastically resilient. The beads are of suflicient bulk in the direction of their major plane that they do not themselves appreciably and of the arms 3, restores the beads to their initial spaced- 1 contract nor expand, but they are interconnected by the integral resiliently expansible and contractible elements 2, contraction of which permits adjacent heads 1 to approach and come approximately or actually into contact, and resilient expansion of which restores the beads to their normal spacing apart.

In the forms of FIGURES 2 to 8 the heads 1 are disposed at diametrically opposite sides of the circular resilient elements 2, so that when installed upon the mesh and relaxed the heads 1 are arranged in a common circle about the codend entrance, and when the circle of heads is contracted the individual beads will move circumferentially more or less into contact with adjacent beads, thereby to limit the contraction. In the forms of FIG- URES 11 to 18 the beads 1 are incorporated in resiliently fiexible arms 3, as are also the resiliently circular elements 2. When the mesh is relaxed, as it is when the beads are applied, the elements 2 are fully round, and the arms 3 are relaxed and spread apart, as in FIGURE 11. When the mesh is elongated, and so contracted circumferentially, the arms 3 flex, the elements 2 elongate, and the beads 1 approach closely, or contact, and so limit circumferential constriction of the entrance, as in FIGURE 12. In this form there are two circles of beads, one at each end of the several arms 3. The washers 10 constitute a part of each such head.

If it be desirable to limit the yieldability of the circular elements 2, this can be done in various ways, as for instance, by incorporating in them a diaphragm 20, as in FIGURES 7, 8, 9, 10, and 15.

The form shown in FIGURES l4 and 15 differs from that shown in FIGURES 16, 17 and 19 principally in that the first-mentioned form is made up of an indeterminate number of beads 1 all joined in a continuous, and sinuous, string by the arms 3, within which arms the elongatable circular elements 2 are incorporated, whereas in the lastmentioned form each arm 3, circular element 2 with its ring 21, and bead halves 11a and 11b at the opposite ends of each arms, are made up in separate but identical units, and the bead halves of adjoining units are connected by the screws 13, using washers 10. The continuous form has some advantage at initial installation, and the discontinuous form has the advantage of ease of replacement of a damaged unit. Their manner of functioning is identical.

The form shown in FIGURES 11 and 12 differ from the form in FIGURES 16 and 17 in that an additional assembly of heads is secured on the inside of the codend and this assembly can be identified by their washers 10 in the FIGURES 11 and 12. As shown the inner and outer beads are not in alignment but the rings 2 are. However, the inner and outer beads could be secured to each other as an alternative and this would reduce the number of effective beads and result in greater permissive contraction in use. The interior-exterior type expander ring offers greater resistance to contraction and would be desirable in some trouble.

It is believed that the functioning of the expander ring will be clear. When the beads are installed the mesh is relaxed, as in FIGURES 4, l1, and 16, and the beads are separated to a distance predetermined by the relaxed size of the circular element 2 and the angle and/ or length of the arms 3. Each head is thus located relative to specific mesh squares or points. Now when the mesh is elongated by stress, caused by pull of the sweep lines 82 upon the suspenders, 'and so upon the forward end of the codend, it constricts circumferentially, and since the several beads are fixed relative to specific squares or points of the mesh, these points approach circumferentially, and as well sep arate longitudinally, as in FIGURES 5, 12, and 17. They come into actual or approximate contact, and this prevents further constriction. So contacting, they define a ring or rings of mutually self-sustaining beads, which persists so long as stress causes elongation of the mesh. When the mesh relaxes, the resilience of the circular elements 2 apart relation.

From the foregoing discussion of several typical embodiments of the present invention, other modifications and adaptations thereof will readily occur to those skilled in the art to which the invention is addressed, within the scope of the following claims.

I claim as my invention:

1. In a trawl net, a mesh element defining the entrance to a codend, and elongatable under stress, to be thereby constricted circumferentially, a plurality of pairs of beads each secured to the meshes of said element at points which are circumferentially spaced apart When the mesh is relaxed, the several pairs of beads defining at least one circle about the entrance, and a resiliently elastic element joining the beads of a pair, and elongatable upon elongation of the mesh for approach of the beads circumferentially into effective contact with other such beads, and thereby to limit constriction of the entrance.

2. A trawl net as in claim 1, wherein the beads are secured to the meshes so as to form two circles thereof about the entrance.

3. A trawl net as in claim 2, wherein the circles are separated by the net.

4. A trawl net as in claim 2, wherein the beads of each pair are secured to the meshes at points which are spaced longitudinally as well as circumferentially, and the intervening resiliently elastic elements are inclined from one such bead to the next, in a sinuous pattern about the entrance, to define two circles of beads.

5. A trawl net as in claim 4, wherein the beads are secured to the meshes in a sinusoidal pattern on each side of the net, the pattern on one side being inverted to that on the other side.

6. A trawl net as in claim 1, wherein each bead comprises a flat disk, means to secure each such disk to a given point of the mesh, and wherein the resiliently elastic element includes a ring of resiliently elastic material extending between adjacent disks.

7. A trawl net as in claim 6, wherein the securing means comprises a washer applied to one surface of the mesh element, the disk being applied to its opposite surface, and screws joining said disk and washer, and straddling bars of the mesh at a point thereof.

8. A trawl net is in claim 6, including a flexible diaphragm across the ring of resilient material, to limit distortion thereof under stress.

9. A trawl net as in claim 1, wherein each bead comprises a fiat disk, means to secure each such disk to a given point of the mesh, and wherein the resiliently elastic element includes an arm interconnecting adjacent disks, and including a ring of resiliently elastic material intermediate the ends of said arm.

10. A trawl net as in claim 9, wherein each pair of disks and their joining arm is an assembly separate from the like assembly of other disks and arms, each disk being secured to a disk of an adjacent assembly, in a sinuous pattern about the entrance.

11. A trawl net as in claim 9, wherein the pairs of disks and their joining arms are connected in a continuous length, and extend in a sinuous pattern about the entrance.

12. A trawl net as in claim 9, wherein each disk is composed of two halves, and each such half is interconnected by a ring of resiliently elastic material, one half of each disk and its ring being applied interiorly of the entrance, and the other half and its ring being applied exteriorly.

References Cited in the file of this patent UNITED STATES PATENTS 3,018,581 Luketa Jan. 30, 1962 FOREIGN PATENTS 294,363 Germany Oct. 4, 1916

Claims (1)

1. IN A TRAWL NET, A MESH ELEMENT DEFINING THE ENTRANCE TO A CODEND, AND ELONGATABLE UNDER STRESS, TO BE THEREBY CONSTRICTED CIRCUMFERENTIALLY, A PLURALITY OF PAIRS OF BEADS EACH SECURED TO THE MESHES OF SAID ELEMENT AT POINTS WHICH ARE CIRCUMFERENTIALLY SPACED APART WHEN THE MESH IS RELAXED, THE SEVERAL PAIRS OF BEADS DEFINING AT LEAST ONE CIRCLE ABOUT THE ENTRANCE, AND A RESILIENTLY ELASTIC ELEMENT JOINING THE BEADS OF A PAIR, AND ELONGATABLE UPON ELONGATION OF THE MESH FOR APPROACH OF THE BEADS CIRCUMFERENTIALLY INTO EFFECTIVE CONTACT WITH OTHER SUCH BEADS, AND THEREBY TO LIMIT CONSTRICTION OF THE ENTRANCE.

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