US 3379020 A
Description (OCR text may contain errors)
H. A. KRUG April 23, 1968 DOLPHIN 0R MARINE CONSTRUCTION 7 Sheets-Sheet 1 Filed Dec. 7, 1964 A ril 23, 1968 H4. KRUG 3,379,020
DOLPHIN Oli MARINE CONSTRUCTION Filed Deb. 7,. 1964 7 Sheets-Sheet Inventor: .1527/VE/(H H [fez/. 4
April 23, 1968 H.A. KRUG 3,379,020
DOLPHIN on MARINE CONSTRUCTION Filed Dec. 7, 1964 7 Sheets-Sheet 3 Inventor: 175740610 H 7691/ April 23, 1968 H. A. KRUG 3,379,020
DOLPHIN 0R MARINE CONSTRUCTION 7 Sheets-Sheet 4 Filed Dec. '7, 1964 April 23, 1968 I H. A. KRUG 3,379,020
DOLPHIN OR MARINE CONSTRUCTION Filed Dec. 7, 1964 7 SheetsSheet 5 j Inventor: AVE/New 19. Z20
Qrrr Axcvs M April 23, 1968 H. A. KRUG DOLPHIN OR MARINE CONSTRUCTION Filed Dec. 7; 1964 7 Sheets-Sheet 6 I Inventor: fiQv/ve/a/y fi Z120;-
April 23, 1968 H. A. KRUG v DOLPHIN 0R MARINE CONSTRUCTION 7 Sheets-Sheet '7 Filed Dec. 7, 1964 Inventor? flw/ve/cx/ K60;-
United States Patent 3,379,020 DOLPHIN OR MARINE CONSTRUCTION Heinrich A. Krug, Friedertsweg 2 9, Hamburg-Nicnstedten, Germany Filed Dec. 7, 1964, Ser. No. 416,210 Claims priority, application Germany, Dec. 10, 1963,
K 51,576; Feb. 26, 1964, K 52,213
19 Claims. (Cl. 6146) My invention relates to compound pile constructions for marine environments and particularly to means for joining driven piles in dolphin or mooring pile construction.
In harbors, canals and rivers and the like, a variety of wood constructions are used. Generally, the purpose of such constructions is either to' protect other buildings, e.g. wharves, or to serve as independent constructions, e.g. mooring posts for ships. The simplest of such Wood constructions are rubbing poles which are upright-standing poles that are relatively easily placed and serve to protect both the wharf wall and the ships hull. In order to take up the larger thrusts of ships, such rubbing poles are often erected close to larger constructions and are connected thereto if feasible. Commonly, such poles are provided with buflFers which may be spring steel or rubber, such as worn automobile tires. I 7
However, such simple constructions have many limitations and in larger marine installations it is far more common to employ compound constructions comprising several piles. These piles must be joined in some fashion, and it has usually been found necessary to connect the piles by complicated supporting or tightening elements, for example, dowels, iron rods or steel tapes. These means have their own disadvantages since they often require the wooden poles to be drilled or notched to accommodate the dowels, rods or tapes, thus detracting from the' strength of the wood. Further, steel clamps often tend to snap off when the construction is subjected to sudden high stresses or thrusts.
For marine constructions consisting of more than three main piles, the dolphins, even greater horizontal thrust forces must be considered, which forces attack the dolphins at a rather high point. Such dolphins are employed for mooring large ships, or as landing and leading dolphins. Although dolphins may be either rigid or flexible, the rigid dolphins, although they can withstand high stresses and bending moments, have the disadvantage that suddenly applied stresses or collisions between the dolphins and the shifting ship can be highly detrimental. In addition to such physical damage, rigid dolphins are not flexible and tend to be driven out of line easily. Finally, rigid dolphins are generally more expensive to manufacture by reason of the amount of work required to prepare the piles and assemble the same.
It will be appreciated that a satisfactory dolphin necessarily must combine great strength with high elasticity and growing ship sizes require a greater free path for the dolphin to travel in order to absorb the kinetic energy of the ships movements. These requirements are most satisfactorily met by compound dolphins which comprise four or more wooden piles connected in a bundle to provide a strong but flexible unit. These same requirements demand that the connecting means joining the poles meet high and exacting standards. On the one hand, the connecting or joining means must be able to transmit forces throughout the bundle so that no one pole is re quired to carry a major portion of the force, and it must 3,379,020 Patented Apr. 23, 1968 have sufiicient flexibility itself to follow the movements and distortions of the poles. On the other hand, the connection should be durable and inexpensive and should not become loosened during continued use. Previously, such connectors have been primarily steel cable or steel hoops, but these have the disadvantage that they are corroded or destroyed by rust in a rather short time. Then, too, such hoops are tightened by means of screws and frequent observation and maintenance is often required for re-tightening of screws that have become loosened in use. In addition to the above disadvantages, when such prior art connections utilize steel bolts and the like to join several poles in a line through drill holes'through the wood, additional carpenter work is required and the cost of skilled workers to make such holes, notches and the like, increases the cost of the total construction very substantially.
Accordingly, it is a principal object of the present invention to provide a dolphin construction which combines a high degree of flexibility with great strength.
Another object is to provide a dolphin construction wherein it is unnecessary to provide drill holes or notches in the poles which decrease the strength of the poles.
A further object is to provide a dolphin construction which can be shipped in pre-manufactured, uniform parts to the marine site and quickly and economically prepared with a minimum amount of skilled labor.
A still further object is to provide means for joining a plurality of piles or wooden poles simply and easily to form dolphins and similar marine structures of great strength and adaptability.
Various embodiments of my invention are illustrated in the accompanying drawings, wherein:
FIGURE 1 is a perspective view of a dolphin construction according to the invention, with the cross-shaped spacing members in the upper bond removed for purposes of clarity.
FIGURE 2 is a plan view of the dolphin construction of FIGURE 1.
FIGURE 3 is an elevational view of the dolphin construction of FIGURE 1.
FIGURE 4 is an elevational view of another dolphin similar to FIGURE 3, but showing a modified form of connecting bond according to the invention and illustrating the vertical separation of the spacing members of the finished dolphin.
FIGURE 5 is a perspective view of the dolphin modification according to FIGURE 4.
FIGURES 6(a) to 6(d) are perspective views of various modifications of the connecting bonds according to the invention for one, two, three or four piles, respectively.
FIGURE 7 is a perspective view of a further modification of the connecting bond.
FIGURE 8 is a perspective view of a dolphin construction according to the invention joined by one embodiment of the connecting bonds according to the invention.
FIGURES 9(a) to 9(0) are perspective views of the upper parts of various modifications of dolphin constructions wherein a simple straight length of an elastic conneoting bond encircles'each of the poles to be joined one or more times, with the cross-shaped spacing members in the upper bond removed for purposes of clarity.
The present invention contemplates dolphin constructions wherein all poles are spaced apart from each other at predetermined distances and are bundled together into a unitary structure by novel elastic joining means. By such a construction, very stable but flexible dolphins are obtained which can be prepared from uncomplicated parts without difficulty and without the necessity of extensive carpentering such as is required where dolphin construction utilize holes or notches in the poles.
Referring now particularly to the drawings, FIGURE 1 shows a dolphin wherein the vertical poles 1, 2, 3 and 4 are joined together by four elastic connecting elements 5 6, 7 and 8. These connecting elements or bandages comprise annularly shaped rings of elastic material, such as neoprene, with a Shore hardness of 70 or higher. Neoprene is preferable for such a bandage since this material is very stable and highly resistant to deterioration caused by solar radiation or sea water. In addition, the bandages have intermediate layers 80 of polyester fibers or other strong synthetics such as nylon, for reasons to be explained hereinafter.
Briefly, the annular rings or bandages, when encircling the poles, are under tension and therefore tend to draw the poles together. This force is resisted by the spacing members 9 and which are disposed between adjacent poles, as shown in FIGURE 1, and are connected together by means such as a bolt 11. This arrangement is also shown in FIGURES 2 and 3, wherein the disposition of the annular ring connectors, e.g. 5 and 7 and the spacing members 9 and 10 may be seen in different perspective.
As shown in FIGURE 1, and more clearly in FIGURE 3, two sets of annular connectors or bands, comprising each four annular rings and two spacing members in crosswise arrangement, are provided at different levels of the construction. Thus, the second or lower set comprising rings 5', 6', 7 and 8' and spacing members 9' and 10' is arranged about the poles in the same manner as the upper set. The greater the distance between the two sets of bands, the greater is the stability of the entire structure. Therefore, it is desirable to have a considerable spacing between the two sets. Preferably, and as a rule of thumb, the upper level should be disposed above the average high water mark on the piles and the lower level should be disposed slightly above the average low water mark. The annular elastic rings or bandages are preferably constructed of synthetic materials or plastic such as neoprene, as aforesaid, having a Shore hardness of 70 or higher. Such bandages are to be further provided with an intermediate layer or layers 80 of strong synthetic textile material, such as nylon or polyester fibers, having an elongation limit of about 10-15%. With this construction the elastic bandages have the advantage that they will stretch relatively easily under tension to a certain limit, at which time the nylon or polyester material strongly resists further elongation even when exposed to much heavier loads.
In operation, the dolphin structure of the present invention is assembled generally in the following steps. First, the required number of piles, for example, four, are arranged and rammed, by known methods, into the floor of a given body of water. The spacing between the piles as they are rammed should generally approximate the spacing desired in the completed dolphin. In this respect, it should be appreciated that the flexibility of dolphins, according to the present invention, renders immaterial any small errors in the spacing of the piles.
After the poles have been rammed, in substantially vertical positions, the annular rings of selected length and strength are placed over the tops of adjacent poles. For example, as shown in FIGURE 1, the band 8 may first be placed over the adjacent poles 2 and 3, thus pulling the poles toward one another because of their flexibility and because there is no substantial force resisting this pull. When the ring has been lowered to the proper position along the lengths of the poles, the poles 2 and 3 are then driven apart by jacking means 82 such as hydraulic or mechanical tools having broad bases or plates so as not to damage the wood. When the poles 2 and 3 have been separated the desired distance, a provisional hold- 4 ing means 84 such as a log or other device may be inserted between the poles to hold them in that spaced relation while the jack is removed, to, for example, force the joined poles 1 and 4 apart against the pull of the annular band 7. Of course, the jack between poles 2 and 3 could be left in place and additional jacks could be provided to separate the other poles but that would entail the added expense of the extra jacks.
Remembering that the annular bandages have an effective elongation limit due to the intermediate layers of polyester or the like, it should be pointed out that the band length should be selected, with respect to the desired spacing of the poles, so that the bands, when the poles have been spaced by the jacks, are under substantial tension approaching the elongation limit of 10-15%. The reason for this is that the bands must exert substantial force upon the dolphin poles in the normal condition in order to give strength and stability to the structure. But, when the dolphin is subjected to great stresses and thrusts, the bands should have the ability to absorb such stresses without substantial additional elongation and consequent separation of the poles. On the other hand, there obviously must be some boundary to this flexibility and the 10-15% elongation limit provides this required terminal point. Thus, for example, if the intermediate layer has an elongation limit of 10%, the connected poles should be spaced apart so that the rings are stretched approximately to this 10% limit.
When the poles 2 and 3, and 1 and 4 have been joined and spaced by jacks, the bands 5 and 6 can be disposed around poles 1 and 2, and 3 and 4, respectively, and those poles can similarly be stretched to the desired spacing, as aforesaid. When all of the poles have been joined as shown in FIGURE 1 and are held in the desired spacing, either by jacks 82 or by temporary holding means 84 the permanent spacing member 9 is inserted between poles 1 and 2 and poles 3 and 4. Similarly the spacing member 10 is inserted so as to space poles 1 and 4 from poles 2 and 3. When these members are in place, the provisional means or jacks may be removed. These spacing members 9 and 10 preferably comprise wooden blocks or plates and are preferably connected by a bolt 11. As shown more clearly in FIGURE 3, the spacing members 9 and 10 and 9 and 10 respectively, are to be disposed substantially at the same level as the respective sets of connecting bands.
More particularly, dolphins as shown in FIGURES 1, 2 and 3, have been built with poles of cross section of approximately 40 x 40 cm. The distance between the poles was also 40 cm. and the annular rings were 50 x 200 cm. in cross section, of neoprene and polyester as aforesaid, and were pre-stretched 10% so that a tensile force of two tons was obtained. Thus, the assembled dolphin was held together with a tensile force of eight tons in each direction. This type construction has the additional advantage that the elastic bonding elements can be selected in any desired strength thus allowing the tensile force to be exactly calculated. All parts such as the poles, annular bands and spacing elements can be prefabricated and brought together for the first time at the construction site. Furthermore, the poles need not be uniform because round poles can be joined to square poles and vice-versa, or all poles can be of the same style cross section.
It should also be appreciated that the described construction permits repairs to be made quickly and easily at any time the dolphin becomes damaged. All that is required is that the dolphin be disassembled to the extent necessary to replace the defective part or parts.
FIGURES 4 and 5 illustrate another embodiment of the present invention. According to this modification, all poles-regardless of whether two, three, four or more poles are used-are held together in the construction by a single annular bandage or ring 16. As shown more clearly in FIGURE 5, the poles 12, 13, 14 and 15 are spaced apart, as before and suitable spacing members 19 and 20 are interposed therebetween. A second set of spacing members 19' and 20, disposed below the water line, are joined to the said upper level spacing members by a chain 23. Blocks B may be joined to the inner sides of the poles to prevent the spacing members 19 and 20 from slipping downward between poles. Similarly, wooden fenders F disposed on the outer sides of the poles serve the dual purpose of protecting the poles and annular bandage and preventing the bandage from moving downward around the poles.
As in the embodiment previously described, it is to be noted that the wooden spacing members, 19, 2t) and 19, 29, are movable to a certain extent and can adjust themselves to deformations of the dolphin caused by collisions, both of minor and major nature, with ships. Further, if a dolphin is struck at such an angle that only one pole is contacted, probably the most usual situation, the thrust is transmitted through the elastic band and spacing member joint so that no one pole is required to absorb the entire force.
,Instead of embracing all of the poles with a ring, as shown in FIGURE 5, one or more simple bands may be employed. These straight lengths can be wound around each pole in succession one or more times and, when each pole has been bound, have their free ends joined together or to the adjacent poles. Thus, a similar joining of the dolphin poles may be accomplished with simple straight lengths of'rubber and polyester material as with the annular'rings. Such continuous straight lengths of connecting elements of this type are shown in FIGURES 9(a) to 9(c).
FIGURE 9(a) shows four dolphin poles 101, 102, 103 and 104, joined together by a single band 105 which eneircles each pole and then, in succession, leads to the adjacent poles. As indicated above, the free ends 196, 107 of the band 195, may be joined together, in a suitable manner, when all poles have been joined or may be attached to the adjacent poles. The embodiment shown in FIGURE 9(b) comprises a suitable round rubber-covered polyester cable 115 wound around the four poles 111, 112, 113 and 114- three times each, whereafter the free ends 116 and 117 are joined together under tension, as hereinbefore disclosed. This embodiment is especially practical in commercial applications since the required tension in the band 115 may be achieved simply by embracing the poles of the construction with as many loops of the cable as is necessary.
FIGURE 9(c) discloses a further embodiment of the dolphin construction, wherein the connecting band 120 encircles each of the poles 121, 122, 123 and 124 and joins each pole to the pole disposed diagonally opposite it, rather than with the adjacent poles. f
In a further embodiment of the invention the annular bands are integrally formed with spacing elements in various shapes and sizes, as shown for example in FIG- URES 6(a)(d) and 7, and can similarly be utilized to form a dolphin structure of the type illustrated in FIG- URE 8.
The resilient joining elements illustrated in FIGURES 6(a)-(d) and 7, have the common characteristic of a central plate portion and one or more bandage portions, as desired, at the edges of the plate. For example, FIG- URE 6(a) shows an element 24 having a plate 26 and a single bandage 28 for use with single buffer or rubbing poles. In this case, the plate may be directed so as to act as a damping element or buffer for absorbing thrust forces.
In the connector or joining element shown in FIG- URE 6(b) the rectangular plate 30 is provided with a band 32, 34 secured to the corner regions of each of two opposite ends thereof, whereby two poles may be joined together in a manner analogous to that of the annular rings described heretofore. FIGURE 6(0) similarly illustrates a joining element having a triangular plate 36 and three bands 38, 40 and 42, which bands have their ends secured to the plate at the vertices of the triangle. The joining element shown in FIGURE 6(d) has a crossshaped plate 44 with bands 46, 48, 50 and 52 connecting the corner regions of the ends of adjacent extending crossarms, and is used for dolphins consisting of four poles such as hereinbefore described. In each of the aforesaid elements, the bands have a width substantially equal to the thickness of the plate portion.
Each of the connecting elements shown in FIGURES 6(a)(d) has a resilient plate portion which, as shown by the cutaway portions of these figures,.may be manufactured from a variety of materials, such as rubber, rubber and a web or rubber and reinforcement layers 80, as seen in FIGURES 6(b)-(d), respectively.
In FIGURE 7 the plate portion 52 is made of plastic and, in this embodiment, the construction is similar to thateshown in FIGURE 6(b) but an additional resilient band 54, 56 is provided at each end of the plate superimposed over the bands 58 and 60 respectively. In this embodiment the bands are joined, as before, to the corner regions of the rectangular block but, the bands each has a width less than half of the thickness of the plate.
In the dolphin construction shown in FIGURE 8, four joining elements, 62, 64, 66 and 68 embrace the poles in superimposed relation so that the joining element 62 connects the poles 70 and 72, then joining element 64 connects the poles 72 and 74 and so on. As before, this dol phin is provided with a further and similar arrangement of joining elements at a lower level. In this construction it may be desirable to insert additional spacing elements (not shown) of a non-elastic character between the wooden poles joined as described above in order to achieve a higher degree of stability. These spacing members may be of the type described hereinbefore as, for example, presized and shaped wooden blocks disposed in cross-shaped relationship between the poles.
An additional advantage accruing from the above-described joining elements is that poles of different materials can be joined in this manner in a single dolphin structure. This is highly useful since heretofore it has generally been difiicult to connect a wooden pile with a steel or concrete pile in a stable manner. With these joining elements, however, it is now possible to construct dolphins of several wooden poles 70, 72, 74 joined with one or more mother poles of steel or concrete 76 in a rapid and economical manner. In this type of construction, the mother pole provides increased stability and the wooden poles contribute a desired flexibility.
The method of applying the resilient connector elements to thespaced upright poles to form the structure shown in FIGURE 8 is as follows. When the proper elements have been obtained, the connector' 62 is secured to a frame and the frame is elongated thereby stretching the connector longitudinally until the material comprising the connector has reached its limit of elongation. At that point the frame is placed over the tops of the poles 70 and 72 so that one of the band portions passes around pole 70 and the other band portion passes around pole 72. At this point, the poles may optionally be separated apart to a predetermined distance and spacing members, similar to members 9 and 10 of FIGURE 1, may be interposed between the poles 70 and 72. The addition of these spacing members provides the aforesaid rigidity to the completed structure.
After the spacing members have been inserted, as desired, the frame is released and the band portions are disassociated therefrom so that the band portions may contract around the periphery of the poles 70 and 72. Thus, the poles are held securely with the plate portions of the connector disposed therebetween. In similar fashion, the connector 64 may be secured to the poles 72 and 7 4, and so on until the structure is complete.
While various embodiments and modifications of the present invention have been presented herein, it should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various combinations and modifications wholly within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. The scope of my invention is set forth and defined by the appended claims.
What is claimed is:
1. A bound dolphin structure, comprising a plurality of spaced, rammed piles, resilient connecting means of rubber-elastic composition adapted to join said piles and to urge each pile toward each adjacent joined pile, said connecting means comprising elongated bands having an interior layer of material for imparting a limit of elongation to said bands, and inelastic spacing means interposed between said joined piles to maintain said bands in an expanded beyond normal state within the elastic limit of the material, said spacing means and said resilient bands cooperating to hold each of said piles in a predetermined space relationship one with the other.
2. A bound dolphin structure comprising four spaced and rammed piles arranged in the configuration of a rectangle, a first resilient ring connecting only; the first and second of said piles, a second resilient ring connecting only the third and fourth of said piles, a third resilient ring connecting only the first and fourth of said piles, and a fourth resilient ring connecting only the second and third of said piles, said resilient rings being in a tensioned condition, and spacing members disposed between said piles to maintain each of said rings in a tensioned, expanded beyond normal state, said spacing members and said expanded rings cooperating to bind said piles together in a predetermined spaced relation.
3. A bound dolphin as defined in claim 2, wherein said spacing members comprise two superimposed blocks in cross-shaped array connected by at least one bolt, one of said blocks being arranged parallel to and between said first resilient ring and said second resilient ring and the other of said blocks being arranged parallel to and between said third resilient ring and said fourth resilient rings.
4. The method of constructing a bound dolphin having a plurality of spaced piles which comprises the steps of placing an annular resilient ring about each pair of adjacent piles, forcing each of said joined piles away from the piles to which it is joined to a predetermined distance to place each of the connecting rings in a tensioned, expanded state, and inserting permanent spacing members between said piles to maintain the rings in the tensioned, expanded state so as to hold the piles in spaced relation.
5. The method according to claim 4, and additionally comprising the step of inserting temporary spacing means between said piles in each connected pair while said pairs of piles are being forced apart in successive fashion and before said permanent spacing members are inserted.
6. A joining element for marine constructions embodying a plurality of upright poles, said element comprising a central resilient rectangular plate portion, a resilient band portion secured to the corner regions of one end of said plate portion, and a second band portion secured to the corner regions of the opposing end of said plate portion.
7. A joining element according to claim 6, and additionally comprising a third band portion superimposed over and spaced from said first band portion and secured to the same said corner regions of said end of said plate portion, and a fourth band portion superimposed over and spaced from said second band portion and secured to the same said corner regions of the said opposing end of said plate portion.
8. A joining element for marine constructions embodying three of upright poles, said element comprising a triangular plate portion and a resilient band portion provided at each side of said triangular portion, each of said bands being secured to adjacent vertex regions of said triangular portion.
9. A joining element for marine constructions embodying four upright poles, said element comprising a resilient cross-shaped plate portion having extending arms, and four resilient band portions, one end of each of said band portions being secured to a corner region of one of said arms and the other end of said band portion being secured to the adjacent corner region of the adjacent arm, whereby the spaces between said arms are enclosed by said band portions.
10. A joining element according to claim 15, wherein said resilient plate is provided with a plurality of interior reinforcing layers of textile material.
11. A structure for marine use comprising a plurality of spaced upright poles, a plurality of joining elements comprising a resilient central plate portion and a rubberelastic resilient band portion at one end thereof and a second band portion at the opposite end thereof, said plate portion and said band portions being integrally formed, each of said poles being embraced by one band portion, each of at least two joining elements and the opposed band portions of said joining elements each embracing diiferent adjacent poles so that each plate portion is disposed between adjacent connected poles.
12. A structure according to claim 11, wherein at least one of said upright poles is constructed of metal and the remainder of said poles are Wooden.
13. A structure according to claim 12 wherein at least one of said upright poles is constructed of concrete and the remainder of said poles are constructed of wood.
14. A structure according to claim 11 wherein said poles are arranged so as to bound a rectangular figure, and additionally comprising spacing members interposed between said connected poles to rigidify said structure.
15. The method of joining a plurality of spaced upright poles to form a marine structure which comprises the steps of forming a resilient connector having a central plate portion and integral band portions at each end thereof the distance between opposed band portions in the normal, relaxed state being less than the distance between the poles to be joined by said opposed bands, stretching said connector longitudinally, moving said connector so that one of said band portions passes around one of said poles and the other band portion passes around an adjacent pole to be joined thereto, releasing said connector so that said band portions contract around said poles, respectively, and repeating each of the aforesaid steps successively with each adjacent pair of said poles.
16. The method according to claim 15, which comprises the additional step of inserting spacing members having a Width greater than the distance between opposed ends of said plate portions when said connector is in a normal, relaxed state between said joined poles before releasing said connector so as to rigidify said structure.
17. A bound dolphin structure comprising a plurality of spaced rammed piles, resilient connecting means of rubber elastic composition adapted to encircle each of said piles and to urge each pile toward each other pile to which said first pile is joined, and inelastic spacing means interposed between said joined piles so as to maintain said connecting means in an expanded, beyond normal state, said spacing means and said connecting means cooperating to hold each of said piles in a predetermined spaced relation each with the other.
18. A dolphin structure according to claim 17 wherein said resilient connecting means comprises a single length of resilient banding having an exterior portion of weather-resistant elastic material and an interior layer of polyester material with a limit of elongation, whereby said bands are tensioned by the spacing of said piles and elongated to a point where stresses applied to said dolphin structure and said piles will not effect further substantial elongation of said bands.
9 it) 19. A dolphin structure according to claim 17 wherein 2,906,312 9/1959 Freedlander 152323 the spaced piles comprise four vertical poles arranged in 3,165,138 1/1965 Manchetti et al. 152-354 the configuration of a square, said resilient connecting FOREIGN PATENTS means joins each of said poles with the pole standing diagonally opposite thereof and said resilient connecting 5 699,624 11/1953 Great Britainmeans extends diagonally between said poles. 4191132 3/1947 Italy- References Cited D 1 024 44; Z I SS S G A 11 as e ruar erman t' to UNITED STATES PATENTS Wedgekind. y pp ca on 10 1,837,988 12/1931 Oberschulte 6146 2 424 35 7 1947 Schwan 1 4 JACOB SHAPIRO, Primary Examzner.
2,722,906 11/1955 Tweddell 6148 X JACOB L. NACKENOFF, Examiner.