US3797806A

US3797806A - Seine-hauling block

Info

Publication number: US3797806A
Application number: US00157334A
Authority: US
Inventors: L Demmert
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-01-05
Filing date: 1971-06-28
Publication date: 1974-03-19
Anticipated expiration: 1991-03-19

Abstract

The floats of a seine are lodged in pockets formed between radial webs on the sheave of a seine-hauling block, which serve as abutments to grip the floats for increasing the traction on a seine in hauling it. The seine netting passes through slots in axial alignment with each radial web. Adjacent slots may be offset axially to afford a serpentine path for the seine around the sheave. The sheave is powered by a hydraulic motor. A guard roller mounted below the sheave will strip from the pockets floats lodged in them which are not released before reaching the roller.

Description

nited States Patent [191 Demmert 1 1 SElNE-HAULING BLOCK [76] Inventor: Lawrence E, Demmert, 3408 Redwood Ave, Bellingham, Wash. 98225 [22] Filed: June 28, 1971 [21] App]. No.: 157,334

Related US. Application Data [63] Continuation-impart of Ser. No. 701, Jan. 5, 1970,

Pat. No. 3,535,811.

[ Mar. 19, 1974 2.875.547 3/1959 Puretic 43/8 2.802.366 8/1957 Borner 254/191 X FOREIGN PATENTS OR APPLICATIONS 191.260 6/1967 U.S.SlR 43/8 748.054 4/1956 Great Britain 74/231024 Primary ExaminerAllen N. Knowles Attorney, Agent, or FirmRobert W. Beach [5 7] ABSTRACT The floats of a seine are lodged in pockets formed between radial webs on the sheave of a seine-hauling block, which serve as abutments to grip the floats for increasing the traction on a seine in hauling it. The seine netting passes through slots in axial alignment with each radial web. Adjacent slots may be offset axially to afford a serpentine path for the seine around the sheave. The sheave is powered by a hydraulic motor. A guard roller mounted below the sheave will strip from the pockets floats lodged in them which are not released before reaching the roller.

9 Claims, 10 Drawing Figures PAFENYEWR i s 1924 SHEET 3 BF 3 INVENTOR. z/u eewg paw/2W BY QM SElNE-HAULING BLOCK The labor of hauling fishing seines has been reduced greatly in recent years by hauling seines, particularly of purse seiners, by use of power blocks in which the block sheaves are power-rotated, such as by a hydraulic motor. When such seines are being hauled, however, the netting is wet and slippery. so that it is difficult for the conventional grooved circumference sheave to grip the seine effectively. As a result considerable slippage has occurred between the sheave and the seine, which tends to wear the seine netting and greatly reduces the hauling efficiency and speed.

The problem of slippage between a power block sheave and a seine has been recognized and various attempts have been made to overcome this problem, such as by providing ribs in the sheave groove, examples of which are designated 18 inFIG. 2 of U.S. Pat. No. 2,875,547. Such ribs, however, have not provided a satisfactory solution to the problem.

A principal object of the present invention is to provide a sheave construction for a power seine-hauling block which will afford a substantially positive grip on a seine and particularly at the location of a seine float, so as to increase greatly the traction between the block sheave and the seine.

More particulary it is an object to provide radial webs which form float-receiving pockets therebetween so that such webs will form abutments for the floats so that the seine will be gripped firmly.

A further object of the invention is to insure a more positive grip of the seine floats by the webbed sheave structure by locating the slots aligned with adjacent webs in circumferentially offset relationship to provide a sinuous path circumferentially of the sheave to receive the seine.

It is also an object to insure release or stripping of the outrunning portion of the seine from the sheave irrespective of the poslitiveness of the engagement of the seine with the sheave during hauling.

Another object is to provide very effective traction between a seine and a sheave by use of a sheave construction which is rugged and simple and which will not injure or deteriorate the seine over a long period of use.

FIG. 1 is an edge elevation of a power block having a sheave according to the present invention, and

FIG. 2 is a central vertical section through such block taken on line 22 of FIG. 1. I

FIG. 3 is a developed circumferential section through a portion of the sheave.

FIG. 4 is an edge elevation of a power block having a modified type of sheave according to the present invention, and

FIG. 5 is a vertical section through such block on line 55 of FIG. 4. 1

FIG. 6 is a developed circumferential section through a portion of the block sheave.

FIG. 7 is an edge elevation of a power block having a sheave embodying still another modification of the present invention, and

FIG. 8 is a vertical section through such block taken on line 8-8 of FIG. 7.

FIG. 9 is an edge view of the sheave alone, viewed from line 9-9 of FIG. 8.

FIG. 10 is a developed circumferential section through a portion of the sheave shown in FIGS. 7, 8 and 9 The power block shown in FIGS. 1, 2 and 3 has a sheave l which is rotatively mounted on the axle 2 extending between and carried by the

case side plates

3 and 4. The opposite ends of such axle may be secured in such side plates, so that the sheave rotates on the axle or the axle can be mounted nonrotatively in the sheave and its opposite ends mounted in suitable bearings carried by the side plates. A yoke 5 spans between upper portions of the

side plates

3 and 4 and opposite ends of the yoke are connected to the side plates respectively by

pins

6 and 7. The yoke may have in it one or more apertures 8 which can be engaged by a suspension eye or hook to support the block.

The opposite side plates 9 of the sheave have sheer inner faces disposed in substantially parallel relationship to each other and disposed substantially perpendicular to the rotative axis of the sheave. Spaced circumferentially around the sheave are transverse axial webs 10 preferably in the form of plates disposed substantially in radial planes which are arranged in two sets projecting, respectively, from opposite sides of the sheave into the annular depression between the sheave sides to define pockets between circumferentially adjacent plates for receiving floats as shown in broken lines in FIG. 3. Each of these web plates has a profile of substantially right triangular shape, the right angle of which fits between a shear inner face of the sheave and the hub 11 of the sheave.

In the sheave of FIGS. 1, 2 and 3 the plate webs 10 are arranged circumferentially of the sheave in pairs; one from each set so that the webs of each-pair are disposed in the same radial plane of the sheave. The hypotenuse of each web plate extends substantially between the hub 11 of the sheave and the rim of a side plate 9 at an angle to the sheaves axis exceeding 45, as shown in FIG. 1. An outwardly flaring slot 12 is thus formed between the adjacent hypotenuses of the plate webs of each pair, and such slots are in registration circumferentially' of the sheave- I Because of the plate-like character of the webs and the extent to which they are spaced circumferentially of the sheave, as shown best in FIG. 2, deep pockets l3 are formed between the pairs of webs which flare outwardly because of the outward divergence of the radial webs. The developed average width of each side face of each of the web plates perpendicular to its inclined edge in a substantially radial plane of the sheave is several times as great as the circumferential thickness of one of the web plates, as is clear from FIG. 1. Also, the circumferential width of each pocket betweenadjacent web plates adjacent to the periphery of a sheave side is several times as great as the circumferential thickness of one of the web plates, as shown in FIG. 2. The illustration of FIG. 3 does not show the pockets as being flared, but this figure is included to show more clearly in diagrammatic fashion how the series of floats 14 joined by the float line 14' can lodge in successive pockets of the sheave.

The seine-hauling block can be powered conveniently and conventionally by connecting a hydraulic motor 16 to rotate the sheave 1 relative to the

case

3,4. The sheave should be designed so that the circumferential spacing of the outer ends of the webs is approximately the same as the spacing of the floats 14 on the float line 14, as indicated in FIG. 3. When the seine is being hauled, the netting preferably underlies the floats and the float line, so that it passes through the inner portions of the slots 12 and pockets 13.

The tension force exerted on the seine by winding it in by rotation of the sheave 1 will pull the seine to a greater or lesser extent down into the throats of the flared slots 12 and pockets 13. The floats will engage the leading faces of the webs as shown in FIGS. 2 and 3, so that the webs serve as abutments to exert traction on the float. The degree of pull on the sheave-engaged portion of the seine will determine the extent to which the seine netting and float line are drawn down into the throats of the slots 12 and pockets 13.

The sheave produces very effective traction on the seine because the greater the pulling force on the sheave-engaged portion of the seine the farther the seine and float line will be pulled into the throats of the webs and pockets and, consequently, the tighter will be the grip of the sheave on the seine. There should be sufficient space between the floats 14 so that successive floats will enter successive pockets 13, and the pockets should be sufficiently wide so that the floats can move radially inward a substantial distance, such as approximately half way between the rims of the side plates 9 and the hub 11.

Irrespective of how tightly the seine may be drawn into the throats of the slots 12 and pockets 13, it is important that the seine be stripped from the sheave instead of winding on the sheave more than one convolution. For this purpose a guard roller 17 is mounted below the sheave. Preferably such roller is of cantilever construction. and its supported end is carried by the side plate 3 shown in FIG. 1. If insufficient tension to strip the seine from the sheave is applied to the outrunning side of the seine, as shown at the left of FIG. 2, the seine will be pressed against the left side of roller 17 which will effect stripping of the outrunning stretch of the seine from the sheave. If the seine should tend to catch on the end of the cantilever roller, side plate 4 could be extended downward for engagement with the corresponding roller end so that the roller would extend across the gap between the side plates and its opposite ends would be supported by them. In addition, if desired, suitable gearing could connect the sheave 1 and the roller 17 so as to turn the roller positively in the same direction that the sheave is turned. Such a powered guard roller would be more effective for stripping the seine netting from the sheave.

The general construction of the block shown in FIGS. 4, 5 and 6 is like that of the block shown in FIGS. 1, 2 and 3. The block frame again includes the

side plates

3 and 4, connected by the yoke 5 through

pins

6 and 7. The difference in construction of this block resides in the sheave l, which again is mounted on an axle 2 carried by the side plates. and such sheave is driven relative to the side plates by the hydraulic motor 16.

In FIGS. 4, 5 and 6 individual plate webs are spaced around the circumference of the sheave instead of pairs of plate webs. Thus webs 18 are located at one side of the sheave to provide outwardly flaring slots 19 between their hypotenuses and the opposite sheave side plate face. Webs 20 project from such opposite face and are disposed in alternating arrangement with the webs l8. Outwardly flaring slots 21 are formed between the hypotenuses of the webs 20 and the face of the sheave side plate from which webs 18 project.

As in the type of device described previously, again each plate web is of substantially right triangular profile, having its right angle fitted into the angle between a sheer face of the sheave and the sheave hub. The hypotenuse extends substantially from the hub to the rim of the sheave side plate from which the web projects.

As shown in FIG. 4, the axial extent of each hubengaged web root exceeds one-half of the axial spacing between the sheave side plates, so that the inner portions of the webs overlap circumferentially. Consequently, the bottoms of the flaring

slots

19 and 21 are offset axially of the sheave so that the inner portions of such slots form a serpentine path circumferentially of the sheave to receive the seine webbing. The pockets 22 between the adjacent webs should be sufficiently wide and deep to receive the floats 14 well below the outer edges of the webs.

As with the block shown in FIGS. 1, 2 and 3, the greater the tension on the sheave-engaged seine portion, the farther the web and floats will be pulled into the

slots

19 and 21 and the pockets 22. The spacing of the webs should be such, with respect to the spacing of the floats 14 along float line 14. that the floats and float line will be drawn into a serpentine configuration as indicated in broken lines in FIG. 6. The resulting displacement of the floats ahead of the webs will enable such webs to serve as more effective abutments for increasing the traction of the sheave on the seine.

As in the case of the block shown in FIGS. 1 and 2, the block of FIGS. 4 and 5 also has a guard roller 17 carried by the side plate 3 at a location below the sheave l, which will act to strip the outrunning stretch of the seine from the sheave irrespective of how firmly it is lodged in the

flaring slots

19 and 21 and pockets 22, and despite the fact that the seine has a serpentine configuration circumferentially of the sheave, as indicated in FIG. 6.

The power block shown in FIGS. 7, 8, 9 and 10 has the same type of frame construction composed of

sides

3 and 4, yoke 5 and pins 6 and 7, as described in connection with the blocks of FIGS. 1 and 2 and of FIGS. 4 and 5. Again, the difference between this block and the blocks previously described resides in the construction of the sheave 1. In this instance the webs spaced around the circumference of the sheave between the side plates 9 include webs both of the type shown in FIGS. land 2 and of the type shown in FIGS. 4 and 5.

In this instance the web structure includes single webs 23 projecting from one side plate of the sheave and separated from the other side plate by a flaring slot 24 and single webs 25 projecting from such other side plate of the sheave and separated from the side plate from which webs 23 project by flaring slots 26. Between adjacent single webs are located pairs of webs 27 having between them outwardly flaring slots 28. Outwardly flaring pockets 29 are thus formed between circumferentially adjacent webs.

The

single webs

23 and 25 are similar to the webs l8 and 20 of the sheave described in connection with FIGS. 4 and 5 and consequently need no further description. Also, the pairs of webs 27 are similar to the pairs of webs 10 described in connection with the sheave of FIGS. 1 and 2, and consequently these webs need no further description. The principal difference between the sheave of the block shown in FIGS. 7 and 8 and the sheaves of the block of FIGS. 1 and 2 and of FIGS. 4 and 5 lies in the arrangement of the webs. In each of the blocks the adjacent webs are shown as being spaced apart circumferentially 45.

Because the inner roots of the

single vanes

23 and 25 are of an axial extent greater than half the distance between the side plates of the sheave, the inner portions of the single webs are in circumferentially overlapping relationship, not only with each other, but with the axially inner portions of the webs 27 arranged in pairs. Such overlapping relationship is indicated both in FIGS. 7 and 9. Consequently, the float line and netting of the seine will have a sinuous configuration circumferentially of the sheave, as indicated in FIG. 10, although not aspronounced as the sinuosity of the seine embracing the sheave of FIGS. 4 and 5, as indicated in FIG. 6.

I claim:

I. In a seine-hauling power block, a sheave having opposite sides spaced apart to provide an annular depression therebetween, and two sets of web plates, the plates of said two sets projecting, respectively, from said opposite sides, upstanding in and spaced circumferentially of said annular depression and defining pockets therebetween for receiving floats therein, each of said web plates of one set having an edge inclined inwardly away from one side peripheral portion of said sheave toward the sheave axis and the axially central portion of said sheave. each of said web plates of the other set having an edge inclined inwardly away from the other side peripheral portion of said sheave toward the sheave axis and the axially central portion of said sheave. the average maximum width of each side face of each of said web plates perpendicular to its inclined edge in a substantially radial plane of said sheave being several times as great as the circumferential thickness of one of said web plates, and the circumferential spacing between adjacent web plates adjacent to the periphery of a sheave side being several times as great as the circumferential thickness of one of said web plates.

2. In the power block defined in claim 1, the sheave sides having inner walls which are sheer and substantially mutually parallel.

3. In the power block defined in claim 2, each of the web plates having an edge joined to an inner sheer wall of a sheave side which is perpendicular to the axially central portion of the sheave.

4. In the power block defined in claim 1, the web plates being arranged in pairs one from each of the two sets, the plates of each pair projecting toward each other from the opposite sides of the sheave, respectively, and having an outwardly flaring slot between them.

5. In the power block defined in claim 1, one of the web plates having an inner root portion projecting from one side of the sheave toward the opposite side of the sheave and of a length more than half the axial width of the sheave depression.

6. In the power block defined in claim 5, circumferentially adjacent web plates projecting respectively from opposite sides of the sheave to dispose portions thereof in circumferential overlapping relationship.

7. In the power block defined in claim 1, and a cantilever stripping roller mounted substantially directly below the rotative axis of the sheave for stripping a seine from the sheave.

8. In the power block defined in claim 1, the inclined edge of each web plate being inclined over at least most of its length at an angle to the axis of the sheave exceeding 45.

9. In a seine-hauling power block including a sheave having opposite sides spaced apart to provide an annular depression therebetween, and two sets of web plates, the plates of the two sets projecting, respectively, from such opposite sides, upstanding in and spaced circumferentially of the annular depression and defining pockets therebetween for receiving floats therein, each of the web plates of one set having an edge inclined inwardly away from the peripheral portion of one side of the sheave toward the sheave axis and the axially central portion of the sheave, each of the web plates of the other set having an edge inclined inwardly away from the peripheral portion of the other side of the sheave toward the sheave axis and the axially central portion of the sheave, and the circumferential spacing between adjacent web plates adjacent to the periphery of a sheave side being several times as great as the circumferential thickness of one of the web plates, the improvement comprising the maximum width of each side face of each of the web plates perpendicular to its inclined edge in a substantially radial plane of the sheave being a plurality of times as great as the circumferential thickness of one of the web plates.

iggggfi" UNITED STATES PATENT OFFIQE CERTIFICATE OF CORREQTMN Patent N 3,797.806 Dated March 19 1974 Inventor(s) Lawrence E. Demmert It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shovm below:

Title page, line 2 of "Related U.S. Application Data", after "Pat. No." and before the numbers insert 3,643,365, which was a continuation-in-part of Ser. No. 759,693,

Sept. 13, 1968, Pat. No.

Column 1, line 6, after "Pat. No." and before the numbers insert -3,643,365, which was a continuation-impart of application Ser; No. 759,693, filed Sept. 13, 1968, now U.S. Pat. No.-.

Column 5, line 35, cancel "average".

Signed and sealed this 13th day of August 1974.

(SEAL) Attest:

McCOY M. GIBSON JR. c. MARSHALL DANN Attesting Officer Commissioner of Patents

Claims

1. In a seine-hauling power block, a sheave having opposite sides spaced apart to provide an annular depression therebetween, and two sets of web plates, the plates of said two sets projecting, respectively, from said opposite sides, upstanding in and spaced circumferentially of said annular depression and defining pockets therebetween for receiving floats therein, each of said web plates of one set having an edge inclined inwardly away from one side peripheral portion of said sheave toward the sheave axis and the axially central portion of said sheave, each of said web plates of the other set having an edge inclined inwardly away from the other side peripheral portion of said sheave toward the sheave axis and the axially central portion of said sheave, the average maximum width of each side face of each of said web plates perpendicular to its inclined edge in a substantially radial plane of said sheave being several times as great as the circumferential thickness of one of said web plates, and the circumferential spacing between adjacent web plates adjacent to the periphery of a sheave side being several times as great as the circumferential thickness of one of said web plates.

8. In the power block defined in claim 1, the inclined edge of each web plate being inclined over at least most of its length at an angle to the axis of the sheave exceeding 45*.