An elastically deformable fender comprising an impact receiving section having a predetermined thickness and a top surface being formed flat and forming a contact surface with a broadside, a pair of supporting sections extending from the reverse side of the impact receiving section mentioned above so as to diverge away from each other in an unfolded fan fashion and formed integrally with the impact receiving section, and fitting sections expanding outwardly from the ends of the supporting sections in parallel to the contact surface aforementioned. The thickness of the impact receiving section mentioned above is formed thick so as to protrude distinctly from the supporting sections and the width is formed smaller than the span between the heels of the supporting sections. Furthermore, between the supporting sections on the reverse side of the impact receiving section a hollow portion is formed lengthwise for preventing the impact receiving section from curving when the contact load of a ship is applied.

BACKGROUND OF THE INVENTION 
The present invention relates to an elastically deformable fender. As the 
elastically deformable fender, a so-called V-shaped fender has long been 
used widely. The V-shaped fender, as shown in FIG. 9, includes an 
elongated body, wherein a flat impact receiving section (1) for receiving 
the broadside, a pair of supporting sections (2) with legs diverging away 
from each other in an unfolded fan fashion and a fitting section (3) 
extending outwardly from the lower ends of each supporting section (2) 
being formed integrally, and has a substantially inverted V-shaped cross 
section. 
Meanwhile, in the V-shaped fender aforementioned, when the impact receiving 
section (1) is compressed by an impact load of the hull of a ship, 
superfluous rubber in the impact receiving section (1) tends to expand 
outwardly into a space between the supporting sections (2), consequently, 
as shown by the dotted line in FIG. 9, curving the impact receiving 
section (1) in the direction of downward expansion of the center portion 
in the drawing at the start of the application of the impact load of the 
hull of the ship. Since the bending of the supporting sections (2) are 
accelerated by the curving as described above, the supporting sections (2) 
become bending from the start of the application of the impact load of the 
hull. 
Then the supporting sections (2) bend and deform as continuously contacting 
the broadside as shown by a dotted single line in the drawing, reaching 
further limited range of deformation within a short period of time and 
cause a sudden rise of the reaction force relatively in a short time. This 
is exactly as shown in a performance curve (X) in FIG. 10, thereby it is 
clear that the sudden rise of the reaction force occurs when the magnitude 
of compression is approximately 40%. In order to improve the absorbing 
performance of the impact energy of the V-shaped fender, the starting time 
of the bending of the supporting sections (2) should be delayed as much as 
possible and the amount of deformation thereof should be larger by 
avoiding the contact between the broadside and the outer surface of the 
supporting sections (2). 
In consideration of this fact, there has been proposed a fender having a 
center groove extending lengthwise on the top surface (i.e. contact 
surface with the broadside) of the impact receiving section (refer to 
Japanese Patent Publication No. 55-12923 and U.S. Pat. No. 3,820,495). 
Since the side portions on both sides of the center groove are compressed 
in a direction of the groove when the impact is applied according to said 
kind of the fender, the fender is influenced by the top surface area and 
variations of frictional coefficient of the broadside and hence the 
absorbing performance of the impact energy is not always stable (refer to 
the performance curves (Y) and (Z) in FIG. 10, wherein (Y) and (Z) 
representing the cases of small and large frictional coefficients, 
respectively). 
In order to solve such problems as described above, the applicant has 
proposed a fender having a suitable ratio between the width of the impact 
receiving section and the span between the heels of the supporting 
sections, and the impact receiving section (1) with the thickness thereof 
being formed thick so as to clearly protrude outward from the supporting 
sections (refer to Japanese Patent Publication No. 56-9604, U.S. Pat. No. 
4,267,792, British Pat. No. 2032050, F.R.G. Patent Offen No. 28566200A and 
French Pat. No. 2413584). 
With this fender, it has been discovered that the similar curving as the 
state shown by the dotted lines in FIG. 9 has occurred again because of 
the fact that the distance between the upper ends of the supporting 
sections expanding inevitably when the improvement was made to reduce the 
surface pressure applied on the broadside by forming the impact receiving 
section widely and widening the top surface area thereof. 
Since the curving of the impact receiving section cause the reduction in 
contact surface between the broadside and the impact receiving section in 
this way, the broadside is exposed to an excessive stress, which involves 
such a disadvantage in that the broadside will be susceptible to 
inflicting damage, denting the ship's hull in particular, in case of such 
a large ship as a tanker. 
The present invention was made in view of this problem as described above 
in order to provide the elastically deformable fender the performance of 
absorbing the impact energy to the broadside of ships from inflicting 
damage with a simple structure. 
The present invention relates to the elastically deformable fender 
comprising an impact receiving section having a flat contact surface with 
the broadside with predetermined thickness, a pair of supporting sections 
depending from the reverse side of the impact receiving section described 
above so as to diverge away from each other in an unfolded fan fashion and 
being formed integrally with the impact receiving section, and the fitting 
sections protruding outwardly from the ends of the supporting sections in 
parallel to the contact surface described above, wherein the thickness of 
the impact receiving section is formed thick so as to protrude from the 
supporting sections by the predetermined length and the width is formed 
smaller than the span between the heels of the supporting sections, while 
between the supporting sections on the reverse side of the impact 
receiving section a hollow portion is formed lengthwise for preventing the 
impact receiving section from curving.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS 
In FIG. 1, an elastically deformable fender (A) made of an elastic material 
such as rubber comprises an impact receiving section (1) having a top 
surface (1a) forming a contact surface having been formed flat, a pair of 
supporting sections (2) extending from both sides on the reverse surface 
of the impact receiving section (1) diverging in an unfolded fan fashion 
and formed integrally with the impact receiving section (1) so as to 
jointly form a hollow portion (B) having a substantially trapezoid-shaped 
cross section and also a fitting section (3) on each end of the supporting 
sections (2) extending outwardly and in parallel to the top surface (1a) 
of the impact receiving section (1) described above. 
Said impact receiving section (1) aforementioned is formed thick so as to 
constitute the side walls (1b) at right angle or substantially right angle 
with respect to the top surface (1a) and to protrude distinctly from the 
upper end of the supporting sections (2). Thus, by forming the impact 
receiving section (1) thick, the curving of the impact receiving section 
(1) at the start of the application of the impact load of the hull of the 
ship can be restrained, and thereby the time at which the supporting 
sections (2) start bending can be retarded as much as possible, as well as 
that the contacting time of the supporting sections (2) with the broadside 
plate during the bending action of the supporting sections (2) thereafter, 
can be delayed as long as possible, therefore ensuring the large amount of 
deformation thereof. In order to exhibit such a working efficiency 
pertinently, the thickness (h) of the impact receiving section (1) is 
suitably set within the range of 0.1H to 0.3H, more preferably within the 
range of 0.2H to 0.25H with respect to the total height (H) of the fender 
(A), and the formed width (W) within range of 1.0H to 1.3H, more 
preferably around 0.12H. However, the thickness of the supporting section 
(2) is set within the range of 0.2H to 0.4H. Where the thickness (h) of 
the impact receiving section (1) is smaller than the range described 
above, there is the possibility, as is the case with the conventional 
V-shaped fender, that is the supporting sections (2) will be bent at a 
relatively early stage of the application of the impact load of the hull 
of the ship, with the bent supporting sections (2) contacting the 
broadside relatively early and increasing the application area O-P of the 
impact load to such an extent as to invite reduction of the energy 
absorbing performance of the fender. On the other hand, where the 
thickness (h) of the impact receiving section (1) is greater than the 
range aforementioned, the length (H minus h) of the supporting sections 
(2) may reduce relatively, tending to increase the reaction force 
excessively in a short time after the application of impact, and 
therefore, the amount of deformation of the supporting sections (2) will 
no longer be maintained. 
Furthermore, the width (W) of the impact receiving section (1) is formed 
smaller than the inside span (D) between the heels of the supporting 
sections (2), and the application area O-P of the impact load of the hull 
is adapted to be positioned constantly within the position (S) (T) 
extending upwardly from the fulcrums (Q)(R) at the bottom of the 
supporting sections (2) during a working period, from the start of the 
application of the impact of the hull (state in FIG. 2) to the completion 
of the application of the impact load, where the bent supporting sections 
(2) become constantly the broadside (state in FIG. 4), thereby avoiding 
the possible excessive reaction force on the fender (A) and hence 
improving the impact energy absorbing performance by the involution effect 
with the structures of the impact receiving section (1) and the supporting 
section (2) described above. 
On the other hand, at the center portion on the reverse side of the impact 
receiving section (1), a groove (1C) as a hollow portion is formed 
continuously lengthwise of the fender (A) in a trapezoid-shaped cross 
section with a deep narrow portion, the depth thereof is preferably less 
than approximately half of the thickness (h) of the impact receiving 
section (1), while the width may be selected suitably in association with 
the volumetric ratio of the impact receiving section (1). 
When the groove (1C) is formed, with the groove (1C) serving as the relief 
of the rubber which is cubically incompressible at the state of the 
application of the impact load of the hull, the curving of the impact 
receiving section (1) can be completely retarded and hence such 
disadvantages as the damage to the broadside caused by the uniform contact 
may be avoided (refer to FIGS. 2 and 3). 
Meanwhile, it is preferable for the supporting section (2) that at least 
the inner surface (2a) of the lower end area be preferably bent widthwise 
at the intermediate portions thereof in a direction approaching each 
other, thereby the impact energy absorbing performance may be improved 
more. Namely, because the supporting sections (2) are bent at the 
intermediate portions, when the supporting section (2) starts bending, the 
bending aforementioned is forcibly made to start from the lower portions 
of the supporting sections (2) as shown in FIG. 2. Accordingly, the 
extreme lowering of rigidity accompained with the start of bending action 
of the supporting section (2) can be restrained, and at the same time the 
contacting time of the supporting section (2) with the broadside can be 
retarded all the more (contacting starts approximate at 55% compression), 
therefore, coupled with the structure of the impact receiving reaction (1) 
described above, the impact energy absorbing performance may be improved. 
The performance curve of the impact energy absorbing effect of the fender 
(A) aforementioned is represented by the curve (U) in FIG. 10. 
Now the embodiment in FIG. 5 shows the groove (1C) formed widely. In the 
embodiment, the thickness (h) of the impact receiving section (1) is set 
at 0.25H with respect to the total height (H) of the fender (A) and the 
width (W) at 1.2H. While the depth of the groove (1C) is formed at 0.08H 
and the width at 0.5H respectively. 
Thus, when forming the groove (1C) widely the volume of the groove (1C) is 
formed preferably within the range of 5% to 15%, and more preferably 
within 10% to 15% of the volume of the impact receiving section (1). 
Within such ranges of volumetric ratios various selections of depth and 
widths of the groove (1C) can be made, but if the width is decided too 
narrow the depth thereof is increased inevitably, which results in the 
thin thickness of the impact receiving section (1) and thus allowing the 
reduction of the rigidity. Accordingly, in the case mentioned above, the 
depth of the groove (1C) is preferably set shallower and the width wider 
than the rigidity of the impact receiving section (1) can be ensured 
sufficiently and the curving may be avoided without fail. However, when 
the width of the groove is formed widely as far as to the roots (2b) of 
the supporting sections (2), the deforming of the impact receiving section 
(1) occur at the corner portion in the bottom of the groove (1C) as the 
starting point, as similarly as simply reducing the thickness of the 
impact receiving section (1), therefore, the uppermost limit of the width 
of the groove (1C) should be set within a range, where the deforming of 
the impact receiving section (1) occur at the root (2b) of the supporting 
sections (2) as the starting point. FIGS. 6 through 8 are front views 
showing deformations of the fender (A) described above at each compression 
ratio, from which it is also clear that the deforming does not occur on 
the impact receiving section (1) for the fender (A) mentioned above. 
The groove (1C) formed as a hollow portion for preventing the curving of 
the impact receiving section (1) may have an inverted U-shaped cross 
section, for instance, or an inverted V-shaped cross section provided with 
a globular top other than the trapezoid-shaped cross section as shown in 
the drawings. Besides, the same effect as mentioned above can be expected 
when the chopped-head conical holes are formed at a fixed interval 
lengthwise in place of the groove (1C). In any case a hollow portion may 
be formed not only in a single row but also in a plurality of rows 
symmetrically arranged will do either. 
The elastically deformable fender according to the present invention is 
capable of restraining the excessive increase of the reaction force during 
the initial stage of the impact load being applied by the approaching 
broadside of a ship, and exhibiting the considerably high impact energy 
absorbing performance by preventing the curving of the impact receiving 
section at the start of the application of the impact load, retarding the 
bent of the supporting sections and delaying the contact of the bent 
impact receiving section with the broadside as much as possible, since the 
hollow portion such as the groove etc. is formed on the reverse side of 
the impact receiving section and serving as the space for relief of the 
rubber at the start of the application of the impact load, the curving of 
the impact receiving section can be prevented assuredly even when 
selecting the width of the impact receiving selection widely, and the 
constant and uniform contact of the impact receiving section with the 
broadside is attainable, thus eliminating the concentration of the stress 
and avoiding such disadvantages as inflicting the damage of denting the 
broadside of a ship.