US3890771A

US3890771A - Aquatic harvester with improved flotation system

Info

Publication number: US3890771A
Application number: US325066A
Authority: US
Inventors: Thomas G Kelpin
Original assignee: Individual
Current assignee: KUTTOTHARA ABRAHAM C DR
Priority date: 1973-01-19
Filing date: 1973-01-19
Publication date: 1975-06-24
Anticipated expiration: 1992-06-24

Abstract

An improved aquatic harvester is disclosed having an aquatic craft comprising a plurality of pontoons secured below a flat deck member, a pick-up assembly mounted on the forward end of the craft to collect aquatic material both at and below the surface of the water and an above-the-water propulsion and steering system having an air propulsion unit. The improvement resides in the design of the pontoon members from at least one closed, integrally formed buoyant capsule constructed of a plastic material.

Description

United States Patent 1 [111 3,890,771 Kelpin 1*June 24, 1975 [54] AQUATIC HARVESTER WITH IMPROVED 3,467,345 9/1969 Windecker 114/665 F X FLOTATON SYSTEM 3,477,213 11/1969 lust et a1 1.

3,698,163 10/1972 Kelpin 56/9 [76] lnventor: Thomas G. Kelpin, 8877 Boyonne Dr., Shreveport, La. 71 108 FOREIGN PATENTS OR APPLICATIONS I 1 Notice: The portion of the term of this 450,788 4/1968 Switzerland 56/9 patent subsequent to Oct, 17, 1989, h b di l i d Primary ExaminerL0uis G. Mancene Assistant ExaminerJ, N. Eskovitz [2n F'led: 1973 Attorney, Agent, or Firm--Richard L. Schwaab [21] Appl. No.: 325,066

[57] ABSTRACT {52] U.S. Cl. .1 56/9; 114/665 F; 1 15/3 An improved aquatic harvester is disclosed having an [51] lift. Cl A0111 aquatic crafi Comprising a plurality of pcntoons [58] Flew of Search 56/8 9; F; cured below a Hat deck member, a pickup assembly 115/5 3 mounted on the forward end of the craft to collect aquatic material both at and below the surface of the l56l References Cned water and an above-the-water propulsion and steering UNITED STATES PATENTS system having an air propulsion unit. The improve- 1,842,125 1/1932 Schwarz 115/3 X men! resides in the design of the pontoon members 3,090,339 5/1963 Carr 114/665 F from at least one closed, integrally formed buoyant 15,860 12/1963 Payne A 4 r 4 F capsule constructed of a plastic materialv 3,270,827 9/1966 Mantle v 115/.5 A X 3,304,900 2/1967 Greenwood 114/665 F 11 Claims, 16 Drawing Figures PATENTEDJUN24 1975 SHEET 7 FIG. I

FIG.2

PATENTED JUN 2 4 I975 SHEET PATENTED JUN 24 ms i; Q n SHEET i 52 I F|G.l6

1 AQUATIC HARVESTER WITH IMPROVED FLOTATION SYSTEM BACKGROUND OF THE INVENTION The present invention relates to an improved apparatus for harvesting aquatic material, and more especially to an improvement of the aquatic harvester disclosed in my U.S. Pat. No. 3,698,163. The aquatic harvester forming the basis for the foregoing patent represents a revolutionary and highly advantageous design for a device for efficiently cutting and harvesting underwater marine plant life, primarily in inland lakes and waterways and also in coastal waterways. The harvester comprises an aquatic craft comprising a plurality of pontoons secured longitudinally to the bottom of a flat deck member with the craft being propelled and steered exclusively by a totally above'the-water air propulsion system. As a result of these design features, the harvester is capable of operating and being easily maneuvered in extremely shallow water while the possibility is minimized that the craft may become fouled with excessive weed growth, floating objects, or hidden underwater obstacles. At the same time, the harvester is capable of carrying payloads in excess of ten tons.

In designing the original harvester, a pontoon structure was sought which would produce an extremely light weight pontoon, yet one which was capable of withstanding the rigors to which the craft was destined to be subjected to as a result of its intended use as well as to provide sufficient buoyancy to carry the payloads of harvested material for which the craft was designed. The pontoon design employed with the prior harvester comprised a continuous length of spirally wound, corrugated wall conduit having folded and crimped seams along the spiral lines of construction. Despite the fact that this particular design fulfilled the requirements set forth above, certain disadvantages nonetheless apear in connection with the use of the harvester fitted with this type of pontoon. For example, in the event that some hidden obstacle was in fact struck with the harvester sufficiently hard to damage the pontoon, as by causing a rupture thereof, the loss of the entire buoyant affect of the damaged pontoon member resulted. While pontoon members of this type could be compartmentalized, this is both relatively difficult and expensive to accomplish. In addition, damage to one compartment of such a compartmentalized pontoon member still requires shutdown of the entire apparatus while the damage is being repaired. It was therefore desired to design a flotation system for the subject aquatic harvester which, without sacrificing in the lightness of weight or buoyancy capacity of the spirally wound conduit, would overcome the aforementioned disadvantages attendant thereto.

SUMMARY OF THE INVENTION Accordingly it is an object of the present invention to provide an aquatic harvester having an improved pontoon flotation system.

Another object of the present invention is to provide an aquatic harvester having a pontoon flotation system which is extremely light weight and buoyant and at the same time resists adverse affects upon the operation of the harvester when a portion of the pontoon is damaged.

Yet another object of this invention is to provide an aquatic harvester having a pontoon flotation system which permits easy replacement of each pontoon or segment of a pontoon in the event of damage thereof, thereby avoiding down-time for the harvester apparatus.

In accomplishing the foregoing objects, there has been provided according to the present invention an aqutatic harvester which comprises an aquatic craft having a plurality of pontoon members secured longitudinally beneath a deck member, a pick-up assembly mounted on the deck of the craft for picking up aquatic material both at and below the surface of the water and an above-the-water propulsion and steering system having an air propulsion unit. Each of the pontoon members comprises at least one closed, integrally formed buoyant capsule constructed of a thermoplastic or suitable thermosetting synthetic resinous material. Preferably, each pontoon consists of a plurality of these thermoplastic synthetic resinous capsules. In one design of such capsules, they may consist of an integral molded exterior shell surrounding an internal cavity, or the internal capacity may be partially or completely filled with a foamed material such as a foamed synthetic resinous material, e.g., foamed polystyrene or polyurethane. The exterior shell of the pontoons is preferably a high impact material such as polyethylene.

Other objects, features and advantages of the present invention will become apparent from the description hereinbelow when taken in conjunction with the accompanying drawings wherein like reference numerals are used to indicate like or equivalent parts.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view, partially cut away, of an aquatic harvester according to the invention, illustrating in phantom lines the unloading position for the pick-up assembly;

FIG. 2 is a right side view of FIG. 1;

FIG. 3 is a top view of the aquatic craft portion of an aquatic harvester according to this invention;

FIG. 4 is a view taken along the line 4-4 in FIG. 1;

FIG. 5 is a perspective view of two pontoon sections according to the present invention;

FIG. 6 is a cross sectional view taken along the line 66 in FIG. 5;

FIG. 7 is a detailed view, partially in section, illustrat ing the actuator means for the pick-up assembly with the unloading position of the assembly illustrated in phantom lines;

FIG. 8 is a skeleton view of FIG. 7 illustrating the path of the actuator chain;

FIG. 9 is a detailed view of the truss member securing the pontoon sections to the harvester;

FIG. 10 is a detailed side view of the engine and air propeller assembly;

FIG. 11 is a top view of FIG. 10;

FIG. I2 is a view along the line 12-12 of FIG. 10, illustrating the steering control assembly;

FIG. 13 is a view along the line l3l3 of FIG. I2;

FIG. 14 is a top view of a chain tightener employed in conjunction with the steering control assembly;

FIG. 15 is a view taken along the line 15-15 of FIG. 11; and

FIG. 16 is a view taken along the lines I6 16 of FIG. 12.

DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawings, and particularly to FIGS. 1 and 2, there is designated generally by reference numeral an aquatic harvester in accordance with the present invention. The basic harvester component is the aquatic craft, designated generally by reference numeral 12, comprising a plurality of pontoon members 14 secured beneath a flat deck member 16. The aquatic craft is driven and steered by a completely above-the-water system comprising an air propulsion unit having an engine 22 and an aerodynamic propeller 24, this unit being secured to a mounting means 26 which is controllably rotatable 360 about a vertical axis. At the forward end of the harvester there is mounted a pick-up assembly 30 which contains a conveyor 32 for picking up aquatic materials at and below the surface of the water and conveying the same onto the deck 16 of of aquatic craft 12. As illustrated in FIG. I, the pick-up assembly may be rotated to an elevated position wherein it serves as an unloading means when conveyor 32 is operated in the reverse or forward direction. In the preferred embodiment, the harvester ap paratus has a horizontal cutter bar assembly 100 located adjacent the forward edge of the pick-up assembly. Most preferably. the cutter bar assembly is operated through direct mechanical linkage with the pickup conveyor 32.

While the foregoing has briefly set forth and described the basic components of the illustrated embodiment of the present aquatic harvester, each of the components will hereinafter be further described in detail.

The aquatic craft comprises four pontoon member 14 secured beneath a flat deck 16 fabricated from wooden tongue and groove boards or conventional steel flooring strips which have been galvanized. Each pontoon is constructed from a plurality of individual, interfitting sections 19 which are identical to one another save for the nose sections which are designed similar to the bow section of a boat in order to facilitate movement of the craft through the water. The payload containing section of the flat deck 16 is defined by the aforesaid portion constructed of flooring material, that portion being confined on three sides by upstanding side rail member 17. The railing immediately forward of the air propulsion system is further provided with upwardly directed louvers 18 which serve to deflect the air thrust away from the vehicle when the propulsion system is in the reverse position. Aft of the payload containing portion of the deck is located an auxiliary deck area 11 fabricated from a light weight metallic mesh material as shown in FIG. 3. Forward of the payload deck area there is secured to the aquatic craft a support frame l3 for the pick-up assembly 30. Beneath the deck 16 and between the pontoons is provided a suitable fuel tank 61.

Overlying the deck member 16 is a bed conveyor comprising laterally spaced endless conveyor chains 40 driven by common line shaft 42. Line shaft 42 in turn is driven by a reversible motor 44, and thus, the bed conveyor is operable to convey in both the forward and aft directions. The endless bed conveyor chains also contain a series of upstanding teeth 46 spaced at intervals along the length of each chain to assist in the movement of aquatic material contained on the deck of the craft during harvesting operations. Also located near the forward end of the bed conveyor are a series of spaced deck risers 48 which are mechanically actuated into the rearwardly inclined position illustrated in FIGS. 1 and 7 to assist in transferring harvested aquatic material from the bed conveyor to the pick-up conveyor when the machine is performing its unloading function. Raising of the pick-up assembly to its unloading position mechanically positions the deck risers 48 into the inclined position through a suitable linkage assembly.

The improved aspect of the present harvester consists in the design and structure of the pontoon flotation system. Accordingly, it has been found in accordance with the present invention that certain pontoon members fabricated from molded thermoplastic or thermosetting synthetic resinous materials will provide a flotation system which is suitably resistant to damage and at the same time provides suitable buoyant capacity to achieve the desired payloads required for a successful harvesting device. Each of the pontoon members comprises at least one closed, integrally formed buoyant capsule constructed of a synthetic resinous material. It is possible to achieve the additional advantages indicated hereinabove by fabricating a single pontoon member so that it contains a plurality of separate internal compartments, a feature which is easily obtainable by employing known methods of construction for synthetic resinous materials. However, the more preferred and illustrated embodiment of the present invention comprises forming each of the four pontoon members 14 from a plurality of individual, interfitting capsules such as those designated by reference numberal 19 in FIGS. 5 and 6. As is evident from these figures, each individual capsule has a male portion 20 located at one end which is adapted to interflt with a corresponding female portion contained in the opposite end of an adjoining capsule. Each capsule is also provided with four pairs of integrally molded flanges which are designed to facilitate rapid attachment to or removal from the aquatic harvester frame. This may be accomplished as illustrated in FIG. 9 by means of bolts 62 which simply pass through each pair of integrally molded flanges on the pontoon capsule and through each of four vertical truss members 112 which extend the length of the aquatic craft and serve, together with transversely extending truss members such as those designated by reference numeral 113 in FIGS. 1 and 9, to support the deck member 16.

Pontoon capsules of this type may be readily fabricated by means of conventional molding techniques, and those constructed utilizing rotational casting techniques are especially suitable for the present embodiment. In the presently preferred design for the pontoon capsules illustrated in FIG. 6, each capsule consists of an integral molded exterior shell 108 consisting of a solid, tough thermoplastic or thermosetting synthetic resinous material surrounding an internal cavity 109. The internal cavity, whether within a single capsule or a compartmentalized pontoon, may optionally be partially or completely filled with a foamed material 107, preferably a closed-cell foamed synthetic resinous material. Suitable synthetic resinous materials for forming the outer shell of the capsule include polyolefins such as polyethylene, polypropylene, etc., styrene polymers including homopolystyrene, styrene copolymers and impact polystyrene, ABS type graft copolymers, polyamides, polyesters, certain acrylic ester polymers, polyurethanes and blends of the foregoing polymers. Fiber glass or other conventional reinforced plastic compositions may also be employed. The optional foam filling in the interior of the capsule may be formed from any of the foamed synthetic resinous materials, such as foamed polystyrene, foamed polyurethane, foamed polyolefins, etc. In the most preferred embodiment of the invention, the pontoon sections are each 36 inches long with a diameter of 26 inches, the outer shell being formed of high impact resistant polyethylene and the interior being approximately one-half filled with a polyurethane foam. Each such pontoon capsule is capable of providing over 700 pounds of total flotation capacity. The resultant pontoons are extremely resistant to impact damage and at the same time are non-rusting, completely inert and impervious to gasoline, battery acid and similar volatile liquids.

The propulsion and steering system of the present invention is illustrated in FIGS. through 16. The basic propulsion unit consists of an engine 22 preferably of the internal combustion type, but of a non-polluting nature, such as a 39l cubic inch V-8 Ford industrial type engine adapted for a vapor fuel such as propane. The engine is operably connected through flexible belt 23 to the aerodynamic propeller 24. Contained internally of the engine 22 is a transmission which is operable by means of lever 25 to engage and disengage the power supply to belt 23 and hence to propeller 24. For safety reasons, there is provided a cage type protector 27 around the propeller.

The propulsion system mounting assembly 26, illustrated in detail in FIGS. 12 through 16, also serves as the steering assembly for the aquatic craft. This assembly comprises a pair of superimposed annular members, consisting of a first annular member 50 and a second annular member 52 each fabricated from angle iron in the illustrated embodiment. The first annular member 50 is rigidly secured adjacent the aft end of the aquatic craft by suitable support members, whereas the second annular member 52 is of slightly smaller diameter than the first annulus, and hence, when concentrically superimposed thereon rests inside the first annular member and is confined thereby so as to be radially immovable with respect thereto. See FIGS. and 16. However, because annulus 52 is freely resting upon annulus 50, the former is freely rotatable through an angle of 360 about the common vertical axis of the annuli. The two annular members are of sufficient diameter to underlie a substantial portion of the propulsion unit in order to provide adequate support and stability therefor. Typically, there is provided bearing members between the two annular members to facilitate rotational movement therebetween. Identified by reference numeral 54 in FIG. 15, such bearing members are preferably fabricated of fiberglass or other synthetic resin laminated or bonded material to serve additionally as vibrating and shock absorbing members. These bearing members may also be channeled and provided with grease fittings to further enhance their utility as bearings. To the upper surface of the second annular member 52 there is secured mounting means in the form of framework 58 for the engine and air propulsion unit.

There is also provided novel rotational means for the steering assembly comprising annular sprocket 70 secured to the second annular member 52 through the engine mounting structure 58. Sprockets 78, and hence the steering assembly, are driven selectively in either the clockwise or counter clockwise direction by reversible electric motor 72 acting through a suitable gear reducer 74 and roller chain 76. Reversible electric motor 72 is a 12 volt DC motor supplied with electrical energy from the ignition system of engine 22. This rotational means provides a steering system which is simple, dependable and practically fail safe, and one which can easily and inexpensively operate from a remote position through simple electrical control circuitry. Thus, at all times when the engine is running, and even when the ignition is merely in the on position, complete control is achieved over rotation of the air propulsion unit. The aforementioned remote control system is preferably one wherein rotation is initiated by simple selection and depression of either a clockwise or a counter clockwise rotation button or switch. Rotation proceeds only when the switch or button is held in the "on position by the operator. However, to further assist the operator, the rotation system may additionally be provided with cut-of switches at the 90 positions about the

annular members

50 and 52, whereby rotation will automatically stop as the propulsion unit is rotated past any one of the four points regardless of whether the operator continues to hold the control switch in the on" position.

In FIG. 14 there is illustrated a typical chain tightener assembly adapted to take up the slack when sprocket and roller chain 76 are rotated in either the clockwise or counter clockwise direction. The chain tightener system comprises two

stationary bars

80 and 82 secured to stationary annular member 50 through structural support member 81, said

bar members

80 and 82 being biased towards one another by spring 85. This biasing action

forces cam rollers

86 and 87 mounted at the end of the two bar members, 80 and 82 respectively, against roller chain 76. Hence, as illustrated in FIG. 14, when sprocket 70 is rotated in the clockwise direction chain slack is taken up by roller 87.

In FIG. 16 there is illustrated a feature which can be optionally incorporated into the steering assembly. This feature consists of an angular bracket 91 secured to the second annular member 52, said bracket depending outwardly and downwardly therefrom to a point below the horizontal flange of first annular member 50. A bearing roller is then disposed inwardly from the downwardly depending section of bracket 91 passing beneath the horizontal flange of annulus 50 to provide a safety feature preventing accidental disengagement of

annular members

50 and 52.

Referring now to FIGS. 1, 4, 7 and 8 wherein there is illustrated the pick-up assembly designated generally by reference numeral 30, it is seen that this assembly comprises a pair of laterally spaced

truss members

33 and 34 rotatably mounted near the upper or aft ends thereof to support frame 13 secured to the aquatic craft l2. Overlying the two

truss members

33 and 34 and extending the full width of the aquatic craft I2 is a continuous mesh surface 35 supported by suitable reinforcing means. Previously mentioned pick-up conveyor 32 in turn overlies the mesh surface of the pick-up assembly. This conveyor consists of a series of pairs of endless conveyor chains 36, the chains of each pair being interconnected by lateral members 37 at spaced intervals along their lengths. It is preferred that at least a portion of each lateral connector 37 extend upwardly from the plane defined by the conveyor chains 36. Like the bed conveyor means on the deck member 16, the pick-up conveyor is selectively operable to convey in both the fore and aft directions, and like the bed conveyor, it is driven by a reversible motor 39 located adjacent the aft portion of the pick-up assembly.

As illustrated in FIGS. 1 and 7, the pick-up assembly 30 may be rotated about the horizontal axis defined by its mounting points on support member 13. Thus, the forward end of the pick-up assembly may be positioned at elevations below the surface of the water or above the deck of the aquatic vehicle, or held at any elevation therebetween. The uppermost position of the pick-up assembly defines the unloading position wherein the aft end of the pick-up conveyor is rotated to a position contiguous with the bed conveyor. [n this position, both the pick-up and bed conveyors may be operated to convey in the forward direction whereupon the payload of harvested aquatic material will be automatically unloaded from the deck of the aquatic craft.

The assembly employed to rotate the pick-up assembly about the aforementioned horizontal axis is illustrated in detail in FIGS. 7 and 8. Referred to herein as the actuator assembly, it comprises a basic power source consisting of a motor 95 which in turn operates a line shaft 96 through a suitable chain and sprocket assembly. The line shaft carries a sprocket 97 beneath

truss members

33 and 34 underlying each side of the pick-up assembly. A finite length of roller chain is secured to truss member 33 adjacent the aft end thereof, said roller chain then extending downwardly and around idler sprocket 94 mounted on the aquatic craft, and thence back up and around idler sprocket 93 secured on the pick-up assembly truss member After passing over idler sprocket 93, roller chain 99 again passes down and around drive sprocket 97 secured on the line shaft 96. Roller chain 99 is caused to pass around the major portion of the circumference of sprocket 97 by passing the same around another idler sprocket 98 mounted adjacent and immediately above the drive sprocket 97, whereupon there is provided absolute engagement of the roller chain 99 about the drive sprocket to accurately control the degree of rotation of the pick-up assembly. The foregoing roller chain assembly is duplicated identically beneath the second pick-up assembly truss member 34 and thus the delineated structure serves the important purpose of assuring uniform rotational adjustment across the entire length of the pick-up assembly. Such uniform adjustment is difficultly attained with similar winch assemblies. The free end of roller chain 99, as it drops off idler sprocket 98, is collected into a suitable receptacle 90 positioned between the pontoon members 14. Likewise positioned therebetween, is a spring assist member 89 to counterbalance the weight of the pick-up assembly and aid in the rotation thereof. Again, identical spring assist members are provided beneath each of the

truss members

33 and 34.

The control system employed to operate the various subassemblies in the present harvesting device may consist either of a conventional hydraulic system of the type utilized in many prior art harvester apparatus or the three-phase 230 volt electrical system described in my prior US. Pat. 'No. 3,698,163.

It will be appreciated that the aquatic harvester of the present invention, like that of my original invention, finds many applications not requiring the presence of a cutting means, e.g., picking up floating aquatic weed growth both at and below the surface of the water,

picking up floating debris from the water, picking up objects off the bottom of a body of water, etc. Likewise, when it is desired to include a cutting means adjacent the forward edge of the pick-up assembly, it will be appreciated that any of the conventional type of cutter bar designs may be employed for this purpose. FIGS. 1 and 7 generally illustrate a cutter bar mechanism located adjacent the forward edge of the pick-up assembly 30. As illustrated in FIG. 4, the second or lower cutter bar 111 is mounted stationary upon the pick-up assembly 30 of the aquatic harvester. The first or upper cutter bar severed served at its mid-point into two sections of equal length and each section is positioned in lateral sliding relationship with stationary cutter bar 111. The two sections of upper cutter bar 110 are then provided with mechanical driving means in the form of cam disks 115 connected to common line shaft 116 carrying the pick-up apparatus conveyor chains. Rotation of shaft 116 and concomitant rotation of cammed disks 115 results in reciprocation of the two sections of top cutter bar 110. It is observed that the two cutter bar sections are timed to reciprocate out of phase with one another, whereupon there is provided a highly effective means of cancelling substantially all vibration resulting from reciprocation of the cutter bar mechanism.

Preferably, mechanical linkage or other means are provided to maintain the cutter bar assembly in the position coplanar with the surface of the water, i.e., horizontal, as the pick-up assembly is raised and lowered to vary the cutting depth of the apparatus. Advantageously, the same linkage serves to rotate the cutter bar into a non-interferring position when the pick-up assembly is positioned to unload harvested payload. The simplest mechanical linkage consisting of one or more elongated members 118 (FIGS. 1 and 7) extending from the cutter bar assembly to support frame 13, and hingedly connected to each, will readily suffice.

A representative aquatic harvester designed in accordance with the foregoing principles and embodying the various hereinabove delineated component systems is constructed utilizing four pontoon members, each consisting of 17 separate 36-inch pontoon capsules of 26- inch diameter, thus giving a total pontoon length of SI feet. The total length of the harvester is approximately 70 feet and the overall width is 18 feet allowing a cutting swath of approximately 16 feet. This harvester is capable of carrying a payload of 21,000 pounds or a volume of 2,l00 cubic feet, while at the same time having a water draft of l2 inches in the unloaded condition and only 20 inches in the fully loaded condition.

Operation of the present harvesting apparatus is essentially identical to that described in my earlier patent for the basic harvester.

While the present invention has been described with reference to a single illustrated embodiment, it is to be understood that many obvious modifications, which will be readily apparent to a person of ordinary skill in the art, may be made to the subject aquatic harvester without departing from the spirit of the present invention. Accordingly, the scope of protection is to be limited only by the claims which follow.

What is claimed is:

1. An aquatic harvester comprising an aquatic craft having a plurality of pontoon members secured longitudinally beneath a deck member said deck member being adapted to receive a payload of harvested aquatic material,

a pick-up assembly mounted on said craft for aquatic material both at and below the surface of the water and as the sole means of propulsion an steering, a single above-the-water propulsion and steering system having an air propulsion unit, mounting means for said air propulsion unit capable of rotating 360 about a vertical axis, wherein said unit comprises an engine, an aerodynamic propeller and means connecting the crankshaft of said engine to the propeller,

each of said pontoon members comprising at least one closed, integrally formed buoyant capsule con structed of a synthetic resinous material.

2. The aquatic harvester according and claim I, wherein each of said pontoon members comprises a plurality of said thermoplastic synthetic resinous capsules.

3. The aquatic harvester according to claim 2, wherein said thermoplastic synthetic resinous capsules comprise an integral molded exterior shell surrounding an internal cavity.

4. The aquatic harvester according to claim 3, wherein said internal cavity is at least partially filled with a foamed material.

5. The aquatic harvester according to claim 4, wherein said exterior shell is constructed of polyethyl ene and said foamed material is a synthetic resinous material selected from the group consisting of polystyrene and polyurethane.

6. The aquatic harvester according to claim 1, wherein each of said pontoon members comprises a single capsule having a plurality of individually sealed internal compartments.

7. The aquatic harvester according to claim 6, wherein each of said internal compartments is at least partially filled with a foamed material.

8. An aquatic harvester according to claim I, further comprising a bed conveyor means overlying the deck member, said conveyor means being selectively operable to convey in fore and aft directions.

9. An aquatic harvester according to claim 1, further comprising mounting means pivotally connecting the pick-up assembly to the aquatic craft so that said assembly projects forward of said craft and is rotatable about a horizontal axis, and actuating means for rotating said assembly to vary the elevation of the forward end of said assembly and to hold the assembly at selected elevations.

10. An aquatic harvester according to claim 1, further comprising a pick-up assembly conveyor means which is operable to convey in both the fore and aft directions, whereby said pick-up assembly serves as an unloading means when the aft end of said pick-up assembly conveyor is rotated to a position contiguous with the bed conveyor means.

I]. An aquatic harvester according to claim 8, further comprising a horizontal cutter means located adjacent the forward edge of the pick-up assembly and mechanical operating means for said cutter means, said operating means being driven by the pick-up conveyor means.

Claims

1. An aquatic harvester comprising an aquatic craft having a plurality of pontoon members secured longitudinally beneath a deck member said deck member being adapted to receive a payload of harvested aquatic material, a pick-up assembly mounted on said craft for aquatic material both at and below the surface of the water and as the sole means of propulsion an steering, a single above-thewater propulsion and steering system having an air propulsion unit, mounting means for said air propulsion unit capable of rotating 360* about a vertical axis, wherein said unit comprises an engine, an aerodynamic propeller and means connecting the crankshaft of said engine to the propeller, each of said pontoon members comprising at least one closed, integrally formed buoyant capsule constructed of a synthetic resinous material.

2. The aquatic harvester according and claim 1, wherein each of said pontoon members comprises a plurality of said thermoplastic synthetic resinous capsules.

5. The aquatic harvester according to claim 4, wherein said exterior shell is constructed of polyethylene and said foamed material is a synthetic resinous material selected from the group consisting of polystyrene and polyurethane.

8. An aquatic harvester according to claim 1, further comprising a bed conveyor means overlying the deck member, said conveyor means being selectively operable to convey in fore and aft directions.

11. An aquatic harvester according to claim 8, further comprising a horizontal cutter means located adjacent the forward edge of the pick-up assembly and mechanical operating means for said cutter means, said operating means being driven by the pick-up conveyor means.