Patent Abstract:
A fender ( 1 ) has a fastening end ( 2 ) and a shock-absorbing end ( 3 ) and, arranged therebetween, at least one deformation portion ( 4 ). The deformation portion ( 4 ) is made of an elastically deformable material, especially elastomeric material, and is arranged to fold during deformation of the fender ( 1 ), so that surface portions of the deformation portion ( 4 ) are folded towards each other. The deformation portion ( 4 ) has on at least one surface projections ( 5 ) and recesses ( 6 ) of such a shape and location that they can engage with each other in a comblike manner when said surface portions of the deformation portion ( 4 ) are folded towards each other during deformation of the fender ( 1 ).

Full Description:
FIELD OF THE INVENTION 
     The present invention relates to a fender with a fastening end and a shock-absorbing end and, arranged therebetween, at least one deformation portion which is made of an elastically deformable material, especially elastomeric material, and which is arranged, during deformation of the fender, to fold so that surface portions of the deformation portion are folded towards each other. 
     BACKGROUND ART 
     Fenders of the type described by way of introduction are used on quays, oil rigs and the like. 
     Such fenders are known from U.S. Pat. No. 5,458,077 which describes fenders of different types, which on their inside are provided with thickenings in order to improve the rigidity of the fender. 
     The fender described in EP 812 961 has similarly been provided with thickenings on its outside or on the inside as well as on the outside. 
     U.S. Pat. No. 3,999,497 discloses a cylindrical fender which on the outside of one end has a tubular rubber element. This rubber element prevents, when subjecting the fender to loads, the fender from suddenly losing its rigidity. 
     EP 135 997 describes a fender which in the outer surface close to its one end is provided with a fold line (slot) to control the deformation of the fender when subjected to loads. As a result, the fender will have a shorter collapsing length and, thus, improved stability. 
     A drawback of the above-mentioned fenders is that they have unsatisfactory stability when subjected to oblique loads. This is a problem since ships, when berthing, to a great extent strike against the fenders at an oblique angle, which means that the shock-absorbing end of the fender is laterally displaced relative to the fender fastening end which is fixedly secured, for instance, to a quayside. 
     According to U.S. Pat. No. 3,948,500, attempts have been made to solve this problem by means of a frustoconical fender with improved lateral stability. However, this fender has very thick walls, which makes the consumption of material great. 
     SUMMARY OF THE INVENTION 
     The object of the present invention is to provide a fender which is improved over prior-art technique. 
     A special object of the invention is to provide a fender with improved deformation properties when subjected to uneven loads. 
     One more object of the invention is to provide a strong fender with a reduced consumption of material. 
     According to the invention, these objects are achieved by the fender of the type described by way of introduction being given the features that are evident from claim  1 . Preferred embodiments are defined in the dependent claims. 
     The inventive fender utilizes a deformation portion which on at least one surface is provided with projections and recesses having such a shape and location that they can engage with each other in a comblike manner during deformation of the fender. As the fender is being deformed, the projections engage in the recesses and provide locking of the fender. Thus, the fender cannot be deformed in the lateral direction and will have improved stability when subjected to oblique loads and shearing load. 
     According to an embodiment of the invention, the projections and recesses are located on an outwardly directed surface portion of the deformation portion. The projections and recesses may instead be positioned on an inwardly directed surface portion of the deformation portion, or on both an inwardly directed and an outwardly directed surface portion of the deformation portion. 
     According to an embodiment of the invention, the deformation portion of the fender has first and second conical hollow portions, whose narrow ends are joined with each other, and the projections are arranged with interspaces forming the recesses, the first and second conical portions being arranged relative to each other in such manner that the projections on one frustoconical portion engage in the recesses on the other frustoconical portion. This design makes it possible to provide the desired locking in a simple and safe manner, while at the same time the manufacture of the fender can be made very rational. 
     In an embodiment of the inventive fender, the first conical portion is made of a material with essentially higher hardness than the second conical portion. This gives the possibility of controlling the deformation of the fender when subjected to loads. The softer conical portion is then pressed together before deformation of the harder conical portion begins. 
     According to another embodiment, the fender is designed as at least two parallelepipedal fender legs. This is an alternative way of making a strong fender according to the invention. 
     The parallelepipedal fender legs advantageously have V-shaped projections. During deformation of the fender, the V-shaped projection will engage in the recess between the legs of the V, which ensures a good stabilizing locking. 
     The deformation portion of the tender is preferably made of an elastomeric material, which gives the fender the desired stability and flexibility. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will now be described in more detail by way of embodiments and with reference to the accompanying drawings. 
     FIG. 1 is a perspective front view and shows a first embodiment of the fender according to the invention. 
     FIG. 2 shows the fender in FIG. 1 in a first compressed state. 
     FIG. 3 shows the fender in FIG. 1 in a second compressed state. 
     FIG. 4 shows the fender in FIG. 1 in a third compressed state. 
     FIG. 5 is a plan view and shows a frustoconical portion of the fender in FIG. 1 seen from above. 
     FIG. 6 is a sectional view and shows a section along line VI—VI in FIG.  5 . 
     FIG. 7 is a perspective view and shows fenders such as the one in FIG. 1 mounted at a quayside. 
     FIG. 8 is a front plan view and shows a second embodiment of the fender according to the invention. 
     FIG. 9 is a side plan view and shows a leg of the fender in FIG.  6 . 
     FIG. 10 is a perspective front view and shows the fender in FIG. 6 in a first compressed stats. 
     FIG. 11 shows the tender in FIG. 6 in a second compressed state. 
     FIG. 12 shows the fender in FIG. 6 in a third compressed state. 
     FIG. 13 is a perspective side view and shows two cooperating fender legs according to FIG. 7 in a first compressed state. 
     FIG. 14 is a perspective side view and shows two cooperating fender legs according to FIG. 7 in a second compressed state. 
     FIG. 15 is a perspective side view and shows two cooperating fender legs according to FIG. 7 in a third compressed state. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     The fender  1  shown in FIG. 1 has a fastening end  2  and a shock-absorbing end  3 . A deformation portion  4  extends between the ends  2 ,  3 . The deformation portion  4  has a plurality of projections  5  and, arranged therebetween, recesses  6 . The deformation portion  2  consists of a first, in the Figure upper, frustoconical hollow portion  7  and a second, in the Figure lower, frustoconical hollow portion  8 . At their narrow ends, the conical portions  7 ,  8  can be interconnected by means of a connecting ring  9  or be glued or molded together. At its wide end, the first conical portion  7  connects to a mounting flange  10 . The second conical portion  8  connects correspondingly to a mounting flange  11 . 
     The conical portions  7 ,  8  are molded in polyurethane. Also other elastomeric materials can be used. Identical molds can be used for the first and for the second frustoconical portion  7 ,  8 , which makes manufacture rational. The mounting flanges  10 ,  11  are molded together with the respective conical portions  7 ,  8 . The mounting flanges  10 ,  11  can also be made with an integrated metal ring. When assembling the fender  1 , the two conical portions  7 ,  8  are arranged rotated relative to each other, so that the projections  5  of the first conical portion  7  will be positioned just in front of the recesses  6  of the second conical portion  8  and vice versa. The first conical portion  7  is made of a softer material (about 70 Shore A) than the second conical portion  8  (about 78 Shore A). The materials can also be selected in reverse order or with the same hardness. If different degrees of hardness are selected, the deformation of the fender can be controlled, so that the softer portion is first pressed together before the deformation of the harder portion begins. 
     The fender  1  is mounted as shown in FIG. 7 at a quayside  13 . The shock-absorbing end  3  is screwed, by means of the mounting flange  10  of the first conical portion  7 , to a fender shield  12 , and the fender  1  with the fender shield  12  is screwed with its fastening end  2 , by means of the mounting flange  11  of the second conical portion  8 , to the quayside  13 . 
     When the fender  1  via the fender shield  12  is subjected to loads exerted by a ship berthing at the quayside  13 , the fender  1  is pressed together, as shown in FIGS. 2-4. Surface portions of the deformation portion are then folded towards each other. FIG. 4 shows how surface portions at the shock-absorbing end  3  of the fender  1  abut against surface portions at the fastening end  2  when the fender  1  has been greatly deformed. Also when subjected to oblique loads, which occurs frequently at quaysides, the fender has good stability since the projections  5  engage in the recesses  6  and provide locking. Therefore the fender  1  is deformed only insignificantly in the lateral direction. 
     The design of the fender  1  causes the forces exerted thereon to be centered in the center of the fender  1 . Moreover, a longer spring length will be obtained, which results in a strong fender  1  with a reduced consumption of material. 
     As is evident from FIG. 6, the fender  1  has projections and recesses both on the outwardly directed surface  14  and on the inwardly directed surface  15 . Other embodiments are also feasible. For instance, the fender may have a smooth inwardly directed surface  15  and projections and recesses on the outwardly directed surface  14  only. A fender can also be made up of two frustoconical portions which are interconnected at their wide ends. The inwardly directed surface  15  of the fender can then be provided with projections and recesses whereas the outwardly directed surface  14  remains smooth. 
     A fender  101  according to another embodiment of the invention is shown in FIG.  8 . This fender  101  is formed with two parallelepipedal supporting legs  106 , of which one is shown in FIG.  9 . The fender  101  can also be formed with more than two fender legs  116 . The fender  101  has a fastening end  102  and a shock-absorbing end  103  and, arranged therebetween, a deformation portion  104  with a v-shaped projection  105 . A recess  106  is formed between the legs of the projection  105 . In each leg, close to the tip of the V, the projection  105  is formed with a recess  117 . In the surfaces outside the projection  105 , the deformation portion  104  has a fold line  118  level with the recesses  117 . At the end which is the upper end in the Figure, the fender  101  has a mounting flange  110  in which a metal plate  119  is positioned. Screw holes  121  for mounting of the fender  101  extend through the outer ends of the flange  110  and the metal plate  119 . Correspondingly, there is at the end which in the Figure is the lower end a mounting flange  111  with a metal plate  120  and screw holes  122 . 
     The fender  101  is molded in urethane rubber, but also other elastomeric materials can be used. During molding, the metal plates  119 ,  120  are molded into the mounting flanges  110 ,  111 . Then the flanges  110 ,  111  are formed with the screw holes  121 ,  122 . 
     The fender  101  is mounted in the same way as the fender  1  described in connection with FIG. 1, with a fender shield  112  at a quayside  113 . As shown in FIG. 9, the fender legs  116  can be mounted with the projection  105  and the recess  106  on a inwardly directed surface  115  or, as shown in FIGS. 10-12, with the projection  105  and the recess  106  on an outwardly directed surface  114 . It is also possible to form fender legs  116  with projections  105  and recesses  106  on both the inwardly directed and outwardly directed surface. 
     When the fender  101  is subjected to loads exerted by a ship berthing at the quayside, it is pressed together as shown in FIGS. 10-15. Like in the fender  1  shown in FIG. 1, surface portions of the fender are folded towards each other as the fender is being deformed. The cooperation of the V-shaped projection  105  with the recess  106  between the legs of the V provides locking of the fender  101 . Therefore the fender  101  maintains good stability also when subjected to oblique loads. 
     The recess  117  and the fold line  118  act as fold indication during deformation of the fender  101 . The fender  101  can also be formed without the recess  117  and the fold line  118 , as is evident from FIG.  10 . 
     Owing to its design, the fender  101  will have an increased spring length, which allows material to be saved, with maintained stability. 
     In the embodiments described above, urethane rubber and molding have been used in manufacture. Also other types of elastomeric materials, however, may be used, and as is known to those skilled in the art, the manufacturing method has be adapted to the selected type of elastomeric material. If, for example, mixtures of natural rubber (NR) and/or styrene butadiene rubber (SBR) are used, which is preferred for fender legs according to FIGS. 8 and 9, manufacture takes place in the traditional manner by the rubber material being supplied to curing molds and cured in these.

Technology Classification (CPC): 5