Construction Elements Of Underwater Trusses

Abstract

Hollow web members having a tension member extending therethrough are engaged at the ends thereof with joint members. The joint members are provided with holes for holding the end of said web members. The specific gravity of the web members and the joint members are substantially equal to that of sea water so that they may be easily assembled in sea water. The truss structure constructed by use of the elements serves as a fishing ground, an auxiliary construction for protecting an underwater construction from impact of waves and so forth.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to construction elements of trusses, and more particularly to construction elements of three-dimensional underwater trusses adapted to be constructed under the water.

This invention is particularly applicable to the construction of large-scale trusses on the bottom of the sea for use as fishing grounds or other types of structure used in the sea. One of the particularly advantageous application of the truss in accordance with this invention is an auxiliary structure around an observation instrument or other kind of instrument provided in the sea for protecting the same from the influence of wave motion.

2. Description of the Prior Art

Artificial fishing grounds which have hitherto been constructed in accordance with prior art have used heavy materials such as concrete blocks or sunken ships. Therefore, the construction of the conventional fishing ground has required great labor and much time for transportation of the materials to the site of construction and for making the fishing ground into the desired shape. There has been a strong desire for elimination of such difficulties in the construction of the conventional fishing ground or other structures in the sea.

Further, in the prior art, it has been impossible to construct a large-scale wave breaker in the sea at depths greater than about 100 m.

In construction of a structure such as a truss in the sea, the most important and difficult problem is how to maintain every point of the structure at a fixed position. Another problem is how to construct trusses in the sea at depths of 20 m or more.

If the above mentioned problems inherent in the prior arts are to be overcome, the structure must have small resistance to the flow of sea water so that its position in space will remain fixed against the sea water flow. Further, the construction must have good versatility in shape, particularly in the case where the construction is used as an auxiliary structure for protecting an instrument or the like in the sea.

SUMMARY OF THE INVENTION

The above-mentioned problems are solved and the requirements mentioned above are met by this invention, in which underwater trusses are constructed by assembling elastic elements.

The principal object of this invention is to provide construction elements which can be assembled into a truss structure which constantly maintains its position in space.

Another object of this invention is to provide construction elements for framing trusses which are rigid enough to maintain their position and at the same time elastic enough to maintain their form against the influence of wave motion.

Still another object of this invention is to provide construction elements for framing trusses which have small surface area so as to have as small fluid resistance as possible.

A further object of this invention is to provide construction elements for constructing trusses which can be assembled in a variety of shapes as desired so that the constructed truss can be made to conform to the contour of the object provided in the sea or can be formed in any desired shape.

A still further object of this invention is to provide construction elements for framing underwater trusses which are light in weight and accordingly are able to form large-scale trusses in the sea.

A still another object of this invention is to provide construction elements for constructing underwater trusses which have substantially the same specific gravity as that of sea water so that they can easily be assembled in the sea and a great weight of the trusses may not be exerted on the elements in the sea.

The construction elements in accordance with this invention basically comprise spherical elastic joint members having a plurality of engaging holes over the whole surface thereof, and web members having elastic portions at both ends thereof to be engaged with the holes of said joint members. The joint members and the web members are made so light in weight that the specific gravity thereof is substantially the same as that of sea water. The web members are preferably made hollow in order to save material and make them light in weight.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a partial longitudinal sectional view showing basic elements of the construction elements in accordance with a simple embodiment of the present invention;

FIG. 2 is a perspective view of a basic truss unit constituted by the joint members and the web members of the construction elements of the present invention;

FIG. 3 is a longitudinal sectional view showing the internal structure of the joint member and the web member constituting the construction elements in accordance with another embodiment of the present invention;

FIG. 4 is a partial longitudinal sectional view of the head of the web member to be joined with the joint member;

FIG. 5 is a partial longitudinal sectional view of the head of the web member joined with the joint member;

FIG. 6 is a partly broken perspective view of a locking means for keeping the head of the web member locked in the joint member;

FIG. 7 is a plan view of the top of a cup for holding the neck portion of the head of the web; and

FIG. 8 is a perspective view of an example of a fishing ground constructed by use of trusses in accordance with this invention.

PREFERRED EMBODIMENTS OF THE INVENTION

Referring to FIG. 1 which shows a foundamental embodiment of this invention, the construction elements comprise a web member 1 and joint members 2 joined at the opposite ends of the web member 1. The web member 1 comprises a hollow steel pipe 10, a pair of elastic end members 11 fixed at the opposite ends 10 of the steel pipe 10, a tension member such as a wire rope 12 tensioned between the elastic end members 11 at the center of the steel pipe 10, and a pair of head members 13 fixed to the opposite ends of the tension member 12. The head member 13 has a hole 13b at an end of a spherical body portion 13a so that the end 12a of the tension member 12 can be inserted therein and tightly fixed thereto. The spherical body portion 13a may be either rigid or elastic. In case that it is rigid, the joint member 2 must be elastic so that the head member 13 of the web member 1 may be snapped into the hole 2a of the joint member 2 by elastic deformation of the joint member 2.

The web member 1 should float or almost float in the water or sea water so that it may be easily handled in the water with small force. If the tension member 12 is not a wire rope but a rigid member, foamed urethane 14 may be used to fill in the space between the hollow steel pipe 10 and the tension member 12 so as to make the specific gravity of the web member 1 as a whole substantially equal to that of the sea water. The tension member 12 tensioned in the web member 1 may be a fabric rope made of polypropylene.

The spherical joint member 2 is provided with a plurality of joint holes 2a having a narrowered opening 2b for holding the spherical head 13 of the web member 1. The hole 2a holds the head 13 of the web member 1 with a holding force strong enough to keep the web member joined with the joint member when the joint members 2 joined at the opposite ends of the web member 1 are pulled apart to strongly tension the rope 12. The spherical joint member 2 is preferred to be elastic, but may be rigid when the head 13 of the web member 1 is elastic enough to easily snap into the hole. In order to prevent the head from easily being removed from the hole, the shape of the head 13 is preferred to be conical or triangular rather than spherical.

The foundamental unit of the trusses constituted by the above elements is a tetragonal unit as shown in FIG. 2. Four web members 1 and four joint members 2 are used to frame this basic unit truss structure.

Another preferred embodiment of this invention is illustrated in FIGS. 3 to 8. In order to construct a large-scale truss which is used for resisting a large force of wave impact or flow of sea water,, the head of the web members is required to be tightly held by the hole of the joint member. Accordingly, a lock means is necessitated at the head of the web member.

Referring to FIG. 3, a web member 3 in accordance with the second embodiments of this invention comprises a hollow tubular portion 3a, a pair of a head portions 3b provided at the opposite ends thereof, and a wire rope 3c extending through the tubular portion 3a and tensioned between the head portions 3a. The hollow tubular portion 3a comprises, in this embodiment, a rigid steel pipe 31 and a plastic protective coating 32. The pipe 31 may be made of concrete or plastic so long as it has strong rigidity and sufficient compressive strength against the impact of waves in the sea. The reference numeral 33 shows a head holder made of light aluminium alloy fixed to the end of the steel pipe 31 and formed to have a deep annular recess 33a to receive a cylindrical elastic head member 34. The elastic head member 34 has a cylindrical form and is tightly engaged with the recess 33a of the head holder 33 concentrically therewith. The end of the head member 34 is rounded and received in a hard plastic cup member 35 to be mated with a joint hole 42 of the joint member 4. The plastic cup member 35 comprises a pair of cup halves (see FIG. 7) and has stopper spring guides 35.sub.1, 35.sub.2, 35.sub.3, 35.sub.4, on the top thereof for moving outward the stopper springs 36.sub.1, 36.sub.2, 36.sub.3, 36.sub.4 (36.sub.3, 36.sub.4 are not shown in FIG. 6) of stoppers 36a, 36b, 36c, 36d. The cup member 35 has key holes 35c and 35d for rotation of the cup member around its axis to move the stopper springs 36.sub.1, 36.sub.2 -- outward to lock the head in the joint hole 42.

The reference numeral 38 indicate a holding ring to tightly hold the elastic head member 34 for preventing excessive distortion thereof.

Referring to FIGS. 4 and 5 showing the detailed construction of the head portion, a socket 37 is secured to the end of the wire rope 3c and a stopper means 36 is provided beneath the socket 37 and said stopper springs 36.sub.1, 36.sub.2 -- are engaged with said spring guides 35.sub.1, 35.sub.2, 35.sub.3, 35.sub.4 formed on the top of the cup member 35. The stoppers 36a, 36b, 36c, 36d are provided with a holding wire 36.sub.5, 36.sub.6, 36.sub.7 -- extending upwards and said stopper spring 36.sub.1, 36.sub.2, 36.sub.3 -- as shown in FIG. 6. The holding wires 36.sub.5, 36.sub.6 -- are held in the socket 37 as shown in FIG. 4 and secured therein together with the wire rope 3c. The lower end of the stopper springs 36.sub.1 -- are engaged with said spring guides 35.sub.1 --, so that the stopper springs 36.sub.1 -- may be moved outward when the cup member 35 is rotated clockwise (in FIG. 7) to move the stoppers 36 outward. The stoppers 36, when moved outward after the head 3b is inserted into the joint hole 42, ride on the reception face 41a of the joint body 41 of the joint member 4 as shown in FIG. 5 so that the head portion 36 of the web member cannot be pulled out.

The wire rope 3c serves to resist against a tension exerted on the web member 3. Another important role of the wire rope 3c is to hold a pipe or an electric lead wire therein for transporting liquid, air or other material desired to be sent through the web member or transmitting electricity therethrough. Thus, the wire rope 3c serves as a nerve system of the truss structure.

The joint member 4 is a hollow spherical body made of steel or rigid hard plastic. The number of the joint holes 42 is properly selected, but the maximum in practical use in 18.

The web members 3 and the joint members 4 are joined together to form a truss structure. One example of a truss structure is shown in FIG. 8. The truss structure is a combination of the regular tetrahedral units shown in FIG. 2, in which a pair of two-dimensional truss structures 51 and 52 extending in parallel with each other are combined by means of binding webs 53a, 53b, -- which in turn form tetrahedral units. For example, webs 53a, 53b, and 53c extending from a vertex 51a of a triangule 51A in the upper two-dimensional truss structure 51 diagonally downward to three vertexes 52a, 52b, 52c of a triangle of the lower truss structure 52 form a regular tetrahedron. Three vertexes 51a, 51b, 51c of the triangle 51A and said vertex 52b form another tetrahedron.

At the corner of the lower truss structure 52 is formed a leg portion 54 made of the truss structure extending downward. The lower end of the leg portion 54 is secured to concrete blocks or the like 55 which are anchored to the bottom of the sea by means of anchors 56.

FIG. 8 shows a corner of a table-shaped under-water truss structure constructed by use of the truss elements in accordance with the present invention.

The truss structure constructed as described above is useful as an under-water structure serving as a fishing ground, an auxiliary structure surrounding an underwater construction for protecting the same from the influence of wave motion, a bed for culturing seaweeds, pearls and other sea products, and also useful as a structure floating on the sea like a floating island for use as a resting place for workers or as a place to work on.

Claims

What is claimed is:

1. Construction elements of underwater trusses comprising a web member having elastic head members secured to each of the opposite ends thereof, spherical hollow opposing joint members having a plurality of holes formed therein, a cup-shaped member covering a portion of each elastic head member and received in one of said holes in each joint member, a tension member extending through said web member and having ends extending through said holes into the hollow portions of said joint members, and stopper means for locking each end of the tension member to said hollow portion of each joint member to interconnect said web member and said joint member in fixed position.

2. Construction elements as defined in claim 1, wherein said web member includes a hollow pipe member made of steel, a rigid cylindrical end member secured to each of the ends of said hollow pipe member, and a plastic coating covering the outer surface of said pipe member and said end member, said elastic head member being retained on said end member secured to said pipe member.

3. Construction elements as defined in claim 2, wherein said end member is made of a light aluminum alloy.

4. Construction elements as defined in claim 2, wherein said elastic head member is provided with a ring about its outer periphery for preventing excessive deformation thereof.

5. Construction elements as defined in claim 1, wherein said tension member is a wire rope, a socket being secured to each of the ends of the wire rope for holding it, and said stopper means comprises a plurality of split stoppers disposed adjacent to the inside end of said socket, said stoppers being movable to a conically outwardly enlarged position where they are engaged with the inner end face of said hole to lock said socket onto the end of the wire rope and within said hollow portion of the joint member, and means operatable in response to rotation of said cup member for moving said stoppers to said outwardly enlarged position.

6. Construction elements as defined in claim 5, wherein said means for moving said stoppers include guide members provided on said stoppers and fixably held at their one ends on said wire end by the socket, and said cup member is provided with guide grooves for receiving and guiding outwardly the other ends of said guide members so as to move said stoppers to the outwardly enlarged position during rotation of said cup member.