EP2085121A1

EP2085121A1 - Swim or diving fin

Info

Publication number: EP2085121A1
Application number: EP09150527A
Authority: EP
Inventors: Fabio Testa
Original assignee: Salvas Sub SpA
Current assignee: Salvas Sub SpA
Priority date: 2008-01-22
Filing date: 2009-01-14
Publication date: 2009-08-05
Also published as: ITGE20080005A1; US20100029153A1

Abstract

Swim or diving fin comprising:
- a footpocket member (1) for housing the foot,
- a blade portion (2) extending from the front end of said footpocket member (1),
- at least a frame member (3) extending in the lengthwise direction of the blade (2) and for at least a predetermined portion of the overall length of the blade (2) along at least a longitudinal side edge of said blade (2)

The frame member or members (3) comprise a perimetral rim member (103) closed on itself and having two opposite and spaced longitudinal branches, which perimetral rim member (103) delimits an inner hollow region, and it has at one or more points arranged on the length thereof one or more transversal bridges (203) connecting said longitudinal branches, the blade (2) being connected to the frame member (3) at one or more of said transversal bridges (203) and/or at least at one of the ends of the rim member (103).

Description

The present invention relates to a swim or diving fin comprising a footpocket member for housing the foot, a blade portion extending from the front end of said footpocket member and at least a frame member extending in the lengthwise direction of the blade and for at least a predetermined portion of the overall length of the blade at least along a longitudinal side edge of said blade.
Several configurations of swim or diving fins have been suggested and the level of the propelling thrust depends on the selected configurations.
The efficiency of the fin depends on its mechanical and hydrodynamic characteristics that in turn depend on the shape and on materials used for making the blade.
The Italian patent FI2002A000171 describes a fin comprising a blade made of relatively rigid material, a footpocket made of relatively yielding material and two lateral ribs extending along edges of the blade. Said ribs are composed of a material having rigidity characteristics intermediate between the ones of the footpocket and of the blade. Ribs extend both above and below the plane of the blade for improving the propulsive efficacy of the fin, without increasing the overall rigidity of the blade and are lined with a yielding material of the type of which the footpocket is made, in order to protect them against scratches and cuts caused when they come into contact with reefs, stones or the like. The lining made of yielding material extends from side edges of the blade up to near the flanks of the footpocket where the cross section of lining becomes considerably thicker to generate fairings that convey the water flow to above a pair of buckles closing the footpocket, projecting sideways constituting an obstacle to the free flow of the water along the fin.
Moreover elastic hinges extending in both the longitudinal and the diagonal direction have been provided on the blade of the fin to permit the deformation of the rigid blade not only in a plane substantially perpendicular to the plane of the blade but also of transverse sections of the fin.
The English patent 2392388 describes a fin with two side arms allowing the blade to be divided into two portions, a front rigid portion fastened to said arms and a movable blade portion mainly fastened to the front portion of the footpocket such that during the fin movement the water flow can be conveyed into the U-shaped channel placed between the two blade portions in order to achieve a low resistance to the blade movement into the water and at the same time to achieve a high propulsion efficiency.
Generally the propulsive part of a fin is composed of a blade portion and at least two lateral ribs giving a certain rigidity and allowing the water flow to be conveyed along the blade towards the free edge such to guarantee a certain propulsive thrust.
The main aim is to take on the greatest amount of water possible and so to push such amount of water backwardly such to generate the desired propulsion.
In known fins the hydrodynamic performance mainly depends on the length of the blade and on its resilient characteristics depending on the material or materials with which the blade is made or on the provision of channels or webbing adjusting the flow of water. The proper resilient behaviour necessary for having an efficaceous propulsion depends on the deformability characteristics of the blade when moving into the water.
In some cases water is taken on by the blade in an unsatisfactory manner otherwise it is taken on by an excessively heavy blade, having an excess of moving masses, which require a considerable effort by the user. Into the water the behaviour of the ideal fin should take the muscular strength of the swimmer into consideration: whether characteristics of the propulsion portion of the fin, i.e. the blade and frame members, are not optimized on the basis of the muscular strength of the swimmer, in the case of swimmers having a small muscular strength or anyway a muscular strength lower than the one the fin has been designed for, the fin can lead to an excessive fatigue and cramps are more likely to happen.
The aim of the present invention is to provide a swim or diving fin having an improved hydrodynamic behaviour with respect to conventional swim fins and allowing a greater propulsion efficiency to be achieved with a lower muscular effort of the lower limbs, thereby reducing the risk of cramps.
Moreover the aim of the present invention is to provide a fin wherein even the user can act on the flexibility level such to set fin performances not only on the basis of its use, for example amusement or agonistic use, but also on the basis of his own levels of physical ability.
These aims are achieved by improving the fin structure both as regards the mechanical profile and the hydrodynamic one.
Particularly a fin provided with one or more frame members is desired having improved hydrodynamic and mechanical characteristics with respect to known fins, helping in guaranteeing a greater propulsion potential, and allowing an aesthetically original and pleasant fin to be made.
The invention achieves the above aims by providing a fin of the type described hereinbefore wherein the frame member or members comprise a perimetral rim member closed on itself and it has two longitudinal branches spaced apart and opposite one to the other, which perimetral rim member delimits an inner hollow region, and at one or more points arranged on the length thereof it has one or more transversal bridges connecting said longitudinal branches, the blade being connected to the frame member at one or more of said transversal bridges and/or at least one of the ends of the rim member.
According to a preferred embodiment that will be described in more details with reference to drawings, the blade has two frame members, each one along a side longitudinal edge of the blade, and said side longitudinal edges of the blade are fastened to the perimetral rim member such that the blade edges are in a substantially intermediate position between said longitudinal branches of the perimetral rim member.
The perimetral rim member is made of a relatively rigid, preferably thermoplastic, material, for example it is made of the same material of the blade portion, while transversal connection bridges are made of a material having different flexibility and resiliency characteristics, particularly resiliency characteristics corresponding to the ones of rubber or the like.
The perimetral rim member of each frame member can have a tapered shape, with reference to its width and/or thickness, particularly in the direction of the free end of the blade. Thus it has a rigidity changing with reference to its length, particularly it has a flexibility increasing towards the free end of the blade.
The rim member forms a kind of leaf spring having predetermined resilient characteristics and allowing more rigid materials to be used, while guaranteeing resiliency characteristics necessary for frame members.
For a local increase of the stiffness of the frame member, a plurality of transversal connection bridges are arranged at a predetermined distance all along the longitudinal extension of the perimetral rim member and said transversal connection members have a predetermined extension lengthwise of the blade.
Advantageously the frame member has one or more inserts at one or more regions or gaps between two adjacent transversal connection bridges. Inserts can be mounted in a movable or fixed manner and have such a shape to partially or completely fill the gap delimited by two adjacent transversal connection bridges and longitudinal branches of the perimetral rim member.
Inserts are made of a material having flexibility or resiliency characteristics different from the ones of materials of the perimetral rim member and/or of transversal connection bridges. Particularly in order to close gaps between bridges inserts made of materials provided with a good flexibility and a certain extensibility can be provided, such as thermoset rubber or the like, in order to achieve a specific hydrodynamic behaviour of the frame member and so of the blade.
The insert is mechanically fastened within the corresponding gap between bridges by means of anti-slip off mechanical locking means, for example by at least a pin and/or tooth oriented transversally to the longitudinal axis of the blade, which pin and/or tooth is engaged into a corresponding recess or dead or through hole provided on the insert or vice versa. Particularly the pin and/or tooth is provided on at least one of the two surfaces of the blade, preferably on both the lower and upper surfaces of the blade, at the longitudinal edge of the blade and is engaged into a corresponding recess or dead or through hole provided on the insert.
According to one embodiment pins and/or teeth are engagement pins which are movably introduced by elastically forcing them and/or by a snap fit engagement into through holes provided on a pair of spaced and parallel appendices of the insert.
As a further alternative, in order to adjust the flexibility of the blade, two or more inserts associated to two or more gaps between transversal connection bridges can be provided to be connected or connectable one to the other by connection brackets. Moreover it is possible to provide inserts to be provided with through holes or recesses, particularly on the outer surface, opposite to the one faced towards the blade, which through holes or recesses allow the flexible or resilient behaviour of said insert and of the frame member to be modified when at least one insert is coupled to the corresponding gap between adjacent bridges.
As in other known fins, the blade is fastened to the frame member, but as regards the fin according to the present invention, the blade edge is fastened to the frame member at at least one of the transversal bridges by chemical-physical adhesion, such as welding, gluing or the like.
According to a particular embodiment the attachment between the blade and the frame member occurs by overmoulding appendices of the material of the transversal connection bridges and said appendices, branching off from the side faced towards the blade, overlap for a certain extension the upper and lower side of the blade.
As an alternative or in combination to said overmoulding appendices, the blade can be fastened to one or more of said transversal connection bridges by side projections of the blade edge engaging, for example by elastically forcing them, into engagement seats into the wall of the transversal connection bridge, particularly into holes passing through the thickness of said bridges.
According to a preferred embodiment side projections of the blade engaging within holes provided on bridges are composed of tapered pins widening towards the engagement end which have a rounded or spherical head and the said pins have such a length to project by the rounded head beyond the outer side of the corresponding transversal connection bridge i.e. such to project on the opposite side of the blade.
According to a particular embodiment a resilient filling member is housed inside the perimetral rim member by a snap fit engagement or chemical physical adhesion, which resilient member has perimetral branches in contact with the inner side of the branches of the perimetral rim member and transversal connection bridges departing therefrom at predetermined distances and arranged on the overall length.
Such as disclosed above at gaps between adjacent transversal connection bridges in combination with the resilient filling member one or more inserts are provided, allowing the flexibility of the frame member to be adjusted.
In such particular embodiment inserts can be inserted into gaps, within the rim member of the frame member, between two adjacent transversal connection bridges and perimetral branches of the resilient filling member in contact with the inner side of longitudinal branches of the perimetral rim member.
According to a further embodiment that will be described in details below, the fin has a single frame member in a median position of the blade preferably at the central longitudinal axis of the blade the blade being divided into two half-blades each one fastened to one of the two corresponding longitudinal side edges of the frame member and to one or more of the transversal bridges connecting longitudinal branches of the perimetral rim member of the frame member. The central frame member allows the blade to be provided with a certain stiffness in order to increase the propulsion potential.
In a further embodiment described in details below, the inner hollow region delimited by the rim member is partially or completely filled with an insert made of a material having resiliency and/or flexibility characteristics different from bridges or the rim member. Particularly the insert is composed of several stratified or laminated materials such to give said insert a predetermined flexible or resilient behaviour and it has ribs, fairings, apertures or grooves modifying the resilient or flexible behaviour of the insert and adjusting the water flow along the frame member or members.
The insert is mounted within the frame member by a mechanical connection, for example by snap fit means, or by a shape-mating engagement or by chemical physical adhesion such as gluing or by overmoulding.
Each side longitudinal edge of the blade is fastened to the perimetral rim member at one or more points of the insert, arranged along the longitudinal extension of the blade at predetermined distances, such that the edge of the blade is in a substantially intermediate position between said longitudinal branches of the perimetral rim member. The connection between the insert and the blade occurs by means of overmoulding appendices and/or by one or more pins branching off from the side edge of the blade engaged by elastically forcing them into one or more through holes provided in the wall of the insert.
Advantages of the present invention are clear from what described above and are the fact of allowing a new type of fin to be made by simple and inexpensive arrangements whose frame members allow a better hydrodynamic behaviour to be obtained closer to the ideal one. Moreover the low weight of the blade portion and the behaviour in water of the frame members combined with the blade portion allow a greater propulsion to be achieved with a lower effort of leg muscles, above all due to the fact that the fin according to the invention is provided with a blade with at least a frame member having a particular structure by which all the blade portion, particularly the frame member, is more light and more resilient than known fins.
Further characteristics and improvements of the invention are object of subclaims.
These and other characteristics and advantages of the present invention will be more clear from the following description of some embodiments shown in annexed drawings, wherein:

Fig.1 is a perspective view of the fin according to the present inventuion,
Fig.2 is a further perspective view of the fin according to the present invention,
Fig.3 is a side view of the fin of fig.1,
Fig.4 is a top plan view of a fin according to the invention,
Fig.5 is a bottom plan view of a fin according to the invention,
Fig.6 is a cross-section view of the blade at the frame member
Fig.7 is a cross-section view of a blade portion and of the frame member,
Fig.8 is a cross-section view of the frame member at the transversal bridge,
Fig.9 is an enlarged perspective view of the side portion of the blade with the insert in the introduced condition according to the present invention,
Fig.10 is an enlarged perspective view of the side portion of the blade at the means for coupling the inserts,
Fig.11 is a perspective view of the fin with an insert in the introduced condition, according to the present invention,
Fig.12 is a perspective view of one embodiment of the fin according to the present invention.

Such as shown in figure 1 the fin is composed of a seat for the foot, the so-called footpocket 1, a blade portion 2 extending from the front end thereof.
The footpocket 1 which may be of the closed type, of the open-heel type with a fastening strap or of any other type, is preferably made of a soft material such as rubber or the like.
The blade 2 has at least a longitudinal frame member 3 for supporting and stiffening the blade 2.
According a not shown embodiment the blade 2 can have a single central longitudinal frame member 3 extending from the tip portion of the footpocket 1 wherewith it is connected up to the free end edge of the blade 2 and it divides the blade 2 into two half-blades, such that the fin is symmetric with respect to its median longitudinal axis.
According to a further embodiment which is not shown the blade 2 may have a single frame member 3 substantially extending from the front end of the footpocket, or from the sides of the footpocket, in the lengthwise direction of the blade 2 towards the end opposite to the footpocket along a single longitudinal side edge of the blade 2. In such case fins will be worn such that the frame member of each blade is faced towards the outer side of the foot and in water the two fins will simulate the behaviour of a single fin provided with two side frame members.
According to a preferred embodiment shown in figures the fin according to the invention comprises a footpocket 1 made of a relatively soft material, a blade 2 made of a relatively rigid material and two side frame members 3 extending, at least for a portion, along side edges of the blade 2 substantially from the front end of the footpocket 1 in the lengthwise direction of the blade 2 towards the end opposite to the footpocket 1.
Such as shown in figures, particularly in figure 3, the frame member extends from the sides of the footpocket 1 at an intermediate portion, between the neck and the front end of the footpocket 1, along side edges of the fin up to the front portion of the blade 2. Such as it is clear in figure 4, it is possible to provide the frame member 3 not to be extended all along the side edge of the blade portion 2, but a front strip of the fin with a predetermined longitudinal extension may be able to bend.
It is also possible to provide the frame member to be extended on the side walls 101 of the footpocket at the tip up to the front edge of the blade 2.
As said above, the frame member 3 can extend all along the side edge of the blade or only along a portion of said edge.
With reference to figures 1 and 2 the blade 2 extends in the area between the two frame members 3 and each frame member 3 is composed of a perimetral rim member 103 which is closed on itself and it has two longitudinal branches which are opposite and spaced with respect to each other and delimiting an inner hollow region 503.
Such as shown in figures 1, 2, 3 the frame member 3 is a substantially spindle-shaped elongated member having a substantially triangular widening region close to the point where it is connected to the footpocket 1 and it tapers towards the free edge of the blade 2, having a thickness decreasing as it approaches the free front end of the blade 2.
The perimetral rim member 103 at one or more points arranged along its length has one or more transversal bridges 203 connecting the two opposite longitudinal branches of the rim member 103, the blade 2 being connected to the frame member 3 at one or more of said transversal bridges or members 203 and/or at at least one of the ends of the rim member 103.
In the case of a fin with two side frame members, each frame member 3 will be connected to the corresponding edge of the blade 2 at at least some or all said transversal bridges or members 203 and/or at at least one of the ends of the rim member 103.
As an alternative if the fin has a single frame member 3 in a median position relative to the blade 2, preferably at the central longitudinal axis of the blade 2, the blade 2 will be divided into two half-blades and each one of said half-blades will be fastened to one of the two corresponding longitudinal side edges of the frame member 3 and to one or more of the transversal bridges 203 connecting the longitudinal branches of the perimetral rim member 103 of the frame member 3.
The frame member 3, such as the blade 2, has a resilient bending behaviour and therefore it has to yield at a greater or lower extent to the resistance it faces into the water, helping the fin to bend according to behaviours that are considered to be the best ones.
Said frame member 3 is make like a resiliently flexible elongated member composed of a rim member 103 made of a relatively rigid material, preferably a thermoplastic material and of transversal connection bridges 203 made of a material having flexibility and resiliency characteristics different from the material of the rim 103 of the frame member 3.
Particularly transversal connection bridges 203 are made of a less rigid material having resiliency characteristics corresponding to the ones of rubber or the like.
The rim member 103 is made of a rigid material, such as conventional frame members, and it acts like a stiffening rib.
The spindle-like shape of the frame member 3 whose perimetral rim 103 starts at an intermediate portion of the footpocket 1, widens with two longitudinal branches at the front-central portion of the blade 2 then it narrows again and connects the two branches at the front blade portion, allows the frame member 3 to have a certain rigidity in the region where it is connected to the footpocket and a flexibility increasing towards the free end of the blade 2.
According to a preferred embodiment each frame member has a plurality of transversal connection bridges 203 placed at a predetermined distance one with respect to the other all along the longitudinal extension of the perimetral rim member 103. Inside the rim member 103, bridges 203 in addition to the fact of being placed at a certain distance one with respect to the other, leaving hollow regions 503, have also a predetermined width.
The particular shape of the frame member 3 and the provision of transversal connection bridges 203 allow the blade 2 to take an arched shape during the fin movement such to improve fin performances. Particularly the provision of bridges 203 connecting the two longitudinal branches of the rim member 103 and the provision of gaps 503 between adjacent bridges allow predetermined extension and compression points to be provided and therefore to adjust the position of the points wherein the blade 2 bends during the movement.
According to a further embodiment it is also possible to provide the frame member 3 to be free from transversal connection bridges 203 and therefore to provide the frame member 3 to be composed of a perimetral rim member 103, closed on itself, with two longitudinal branches which are opposite and spaced one with respect to the other delimiting an inner hollow region. In this case the stiffness of the frame member and so bending movements of the blade 2 into the water will be defined by the hardness of the material.
Figure 12 shows a particular embodiment wherein the perimetral rim member 103 is closed on itself and it delimits an inner area wherein an insert 5¹ is housed. Such insert 5¹ is particularly made of a material having resiliency and/or flexibility characteristics different from bridges 203 or from the rim member 103.
The insert 5¹ completely fills the hollow region delimited by the perimetral rim member 103, that is it has a shape complementary to the region delimited by the rim 103, and it can be mounted within the frame member 3 by a mechanical connection, for example by snap fit means, by shape-mating engagement or by chemical-physical adhesion such as gluing or overmoulding.
Figure 12 shows the insert 5¹ as a single member but it is possible to provide said insert 5¹ to be composed of several members that, once assembled together, fill all the region delimited by the rim 103 of the frame member 3. Particularly it is possible to provide the insert 5¹ to be composed of several stratified or laminated materials in a longitudinal or perpendicular direction with respect to the frame member 3 such to give said insert a predetermined flexibility or resiliency behaviour allowing the flexibility of the frame member 3 and its movement into the water to be modified, once the insert 5¹ is overmoulded or engaged into its seat within the rim 103 of the frame member 3.
According to figure 12 the outer surface of the insert 5¹ is smooth but it is possible to provide said outer surface and therefore sides of the frame member 3, to be provided with ribs, fairings, apertures or notches modifying the resilient or flexible behaviour of the insert 5¹ and at the same time adjusting the water flow along frame members 3.
The perimetral rim member 103 is connected to the blade 2 at at least one of its two ends, particularly one end is connected at one or more points on sides of the footpocket 1 and the second end is connected to the blade 2 close to its free end.
The blade in figure 12 has two frame members 3, each one along a longitudinal side edge of the blade 2, and each frame member 3 is connected to the footpocket 1 and to the blade 2 at one or more points of the insert 5¹ such that the edge of the blade 2 is in a substantially intermediate position between said longitudinal branches of the perimetral rim member 103.
Connection points between the insert 5¹ and the blade 2 are arranged along the longitudinal extension of the blade 2 at predetermined distances.
Such as shown in figure 12 the connection between the insert 5¹ and the blade 2 can occur by means of overmoulding appendices overlapping for a certain width and a longitudinal extension from the inner side, faced towards the blade 2, of the insert 5¹ towards the lower and upper surface of the blade 2 and/or by means of snap fit pins 102.
Particularly it is possible to provide the connection to be made by means of one or more pins 102 branching off from the side edge of the blade 2 and which are engaged by elastically forcing them into through holes provided in the wall of the insert 5¹.
Such as shown in figure 12 pins have such a length that when they are mounted by being elastically forced, they project with their head beyond the outer side of the insert 5¹. According to a particular embodiment the pins 102 of the blade are arranged such to allow the user to replace transversal connection bridges 203 with the insert 5¹ or vice versa and such to modify the behaviour of the frame member 3 during the movement into the water.
Such as shown in figures it is possible to provide the blade 2 to have channels, for example two side channels, and inserts such as webs or the like, on the upper and/or lower surface of the blade 2 in order to improve the hydrodynamic performances of the fin.
Even if for semplicity reasons figures show transversal connection bridges 203 with the same width, considering the frame member 3 in the lengthwise direction, such bridges 203, depending on the desired effect on the overall deformability of the blade and of the material used for said bridges 203, can have different widths, i.e. the same rim member 103 can be provided with a series of transversal connection bridges having different widths, for example a width decreasing from the median portion of the frame member as it approaches the two ends.
Considering that when finning the blade 2 bends due to the water resistance, it is possible to modify the in-fluid motion resistance of the blade 2, without affecting dynamic performances of the fin, by providing for one or more of the regions 503 between a bridge 203 and the adjacent one one or more movable or fixed inserts 5 filling partially or completely the region 503 between one bridge and the other one.
Said inserts 5, arranged within gaps 503 between one transversal bridge 203 and the other one for modifying the resilient behaviour of the frame member 3, are made of a third type of material having resiliency and/or flexibility characteristics different from bridges 203 or from the rim member 103.
One or more inserts 5 for one or more gaps 503 between two adjacent transversal bridges can be provided and said inserts 5 can be placed in a movable or fixed manner into said gap 503 and can have such a shape to partially or completely fill the gap 503 delimited by two adjacent bridges 203 and longitudinal branches of the rim 103 of the frame member 3.
Inserts 5 can be fitted into gaps 503 for example by elastically forcing them or they can be fastened by a shape-mating engagement or by snap fit means.
Such as shown in figures 9 and 10 the insert 5 is mechanically fastened into the corresponding gap 503, delimited by two adjacent bridges 203, by anti-slip off mechanical locking means.
The insert 5 can be locked inside the corresponding gap 503 by a pin and/or tooth 202 oriented transversally to the longitudinal axis of the blade 2.
Said pin and/or tooth 202 is provided on at least one of the two surfaces of the blade 2, preferably on both the lower and upper surfaces of the blade 2, at the longitudinal edge of the blade 2, and, in order to allow the insert to be fastened into the gap 503 of the frame member 3, it has to be engaged into a corresponding recess or dead or through hole provided on the insert 5.
It is possible to provide teeth and/or pins 202 to be on the insert 5 then to be engaged into corresponding recesses or dead or through holes provided along the edge of the blade 2 on one or both the upper and lower surfaces, at the insertion gap 503.
According to a preferred embodiment shown in figures 10 and 11, there are two pins and/or teeth 202 provided on the blade 2 and are placed on the upper and lower face of the blade 2 along the edge of the blade 2 at the gap 503.
When the insert 5 is inserted into the corresponding gap 503, said pins and/or teeth 202 engage with two corresponding recesses or dead or through holes provided on appendices of the insert 5.
Such as shown in figure 10, the plug-like insert 5 has at least a pair of appendices 105 placed along edges of the insert 5 and are spaced apart and parallel one to the other such that they can rest on the lower and upper surface of the blade 2.
In order to guarantee the insert 5 to be fastened on the frame member 3 in the most surely manner pins and/or teeth are like engagement pins which are movably introduced by elastically forcing them and/or by a snap fit connection into through holes provided on a pair of opposite appendices of the insert 5.
According to a further embodiment it is possible to provide the insert 5 to be fastened into the corresponding gap 503 by means of an uninterrupted perimetral flange provided on the outer surface of the insert 5 and which can be engaged with a corresponding uninterrupted groove provided on the inner surface of the gap 503 or vice versa.
As an alternative it is possible to provide the insert 5 to have longitudinal spaced tabs elastically snap fitting into apertures provided on the inner surface of the gap 503 or on surfaces of the blade 2.
In order to guarantee the mutual connection between the insert 5 and the frame member 3 it is possible to provide at each gap 503, several pins and/or teeth on each surface of the blade 2, depending on the length of said insert 5.
Figure 11 shows one embodiment of the fin having two side frame members 3 and a pair of inserts 5 placed into gaps 503 at the median portion of the frame member 3. Particularly, considering the blade portion 2, inserts 5 are inserted into the front portion of said blade 2, near to the region connecting with the footpocket 1. The provision of the insert 5 gives a greater stiffness to the frame member 3 and particularly it gives a greater stiffness to the blade 2 at the footpocket 1, where the insert 5 is provided, and it allows the final portion of the blade 2 to bend when finning.
It is possible to adjust the flexural behaviour of the blade 2 both by introducing one or more inserts 5 into corresponding gaps 503 placed along the longitudinal extension of the frame member 3, and by using different materials for making individual inserts 5, i.e. by using materials having different flexibility and resiliency characteristics. The provision of inserts 5 allows the stiffness of the frame member 3 to be modified and so also the behaviour of the blade 2, which is associated to one or more frame members 3.
Such as shown in figure 11 inserts can be provided with through holes or recesses, particularly on the outer surface, opposite to the one faced towards the blade 2, which through holes or recesses allow the flexible or resilient behaviour of the insert 5 and so of the frame member 3 to be modified.
According to a further embodiment the outer wall of the insert 5¹ can be smooth or, as an alternative, it is possible to provide on said outer surface and so on flanks of the frame member 3, ribs, fairings, apertures or grooves modifying the resilient or flexible behaviour of the insert 5 and at the same time adjusting the water flow along frame members 3.
According to a further not shown embodiment two or more inserts 5 associated to two or more gaps 503 between bridges 203 can be connected one to the other by means of brackets or connection means connecting outer sides of the different inserts 5.
Connection brackets between two or more inserts 5 can be made of different types of material, for example they can be made of a rigid, flexible or resilient material or anyway a material having resiliency or flexibility characteristics different from the materials of the inserts 5 and/or of the perimetral rim 103 of the frame member 3 and/or of transversal connection bridges 203.
The provision of inserts 5 gives the possibility of structurally acting on the flexibility of the blade such to set it according to materials used for making the fin, to the use for which it is intended, and mainly to the degree of ability and physical force of the user.
The provision of inserts 5 moreover allows the user to change the behaviour into the water of the fin even depending on climatic conditions, for example streams and the wave-motion, he is subjected to.
It is possible to provide the combination of a fin such as the one described above and a set of inserts 5. The set comprises different inserts 5 for at least a part of individual gaps 503 between adjacent bridges 203 and each one of said inserts 5 has different resiliency and flexibility characteristics.
Inserts 5 of the set having different resiliency and flexibility characterstics can be marked by a different colour.
The possibility of introducing one or more inserts 5 having different resiliency and flexibility characteristics allows the greatest flexural point of the blade 2 to be changed along the extension of all the fin. Moreover the possibility of connecting two or more inserts 5 by connection brackets allows the stiffness of the fin to be controlled and to be adjusted depending on requirements.
According to one preferred embodiment inserts 5 are a part of an integral member filling the gap defined by the rim member 103 of the frame member 3.
Particularly as shown in figures the rim member 103 defines a space wherein a resilient filling member is housed which resilient member comprises perimetral branches 403 contacting the inner side of longitudinal branches of the perimetral rim member 103 and transversal connection bridges 203 branching off therefrom, at predetermined distances and arranged all along the length.
In such particular embodiment transversal connection bridges 203 are a part of a member filling the space delimited by the perimetral rim member 103 of the frame member 3.
Such as shown in figures the filling member is therefore composed of a set of transversal connection bridges 203 connected one to the other by perimetral contact branches 403 and said filling member has such a shape to be inserted into the hollow region of the frame member 3.
The filling member is mechanically fastened into the rim 103 by snap fit engagement or by forcing it or it adheres to the inner side of the rim 103 of the frame member 3 by a chemical physical adhesion i.e. it is glued, welded or overmoulded.
In combination with the filling member for one or more of the gaps between adjacent bridges there are provided one or more of the inserts 5 described above, that in this embodiment will be between two adjacent transversal bridges 203 and perimetral contact branches 403 of the resilient filling member.
Each edge of the blade 2 is fastened to the corresponding frame member 3 in such a position that the edge of the blade 2 is at an intermediate position with respect to two longitudinal branches of the rim member 103.
Such as shown in figure 6 the edge of the blade 2 can be fastened to the frame member 3 at transversal connection bridges 203 by overmoulding appendices 303 overlapping for a certain exension in the lengthwise direction of the blade 2 the lower and upper face respectively of the blade 2. Thus during the step manufacturing the fin, the step moulding parts made of relatively yielding material, such as for example bridges 203, can also include the overmoulding of appendices 303 branching off from the side of the bridge 203 adjacent to the edge of the blade 2 and overlapping said blade 2 for a certain end strip, locking it.
Such as shown in figure 8 the blade 2 is fastened to one or more of said transversal connection bridges 203 by side projections or appendices 102 of the edge of the blade 2 engaging inside through holes or engagement or snap fit seats provided in the wall of the transversal connection bridge 203.
Side projections 102 of the edge of the blade 2 engage by being elastically forced into the through hole within the thickness of the transversal connection bridge 203.
Such as shown in figures side engagement projections 102 of the blade 2 are composed of tapered pins becoming wider towards the engagement end and having a rounded or spherical engaging head.
The length of said side engagement projections 102 or pins is such that said side projections or pins 102 in the mounted condition by elastically forcing them project by the rounded head beyond the outer side of the correposponding transversal connection bridge 203 i.e. they project on the side opposite to the blade 2.
Such as shown in figure 8 the connection between the blade 2 and the frame member 3 occurs by a pin 102 having a rounded point and being inserted into a hole passing through the thickness of the transversal connection bridge 203. In such embodiment moreover there are provided overmoulding appendices 303 overlapping for a certain extension the upper and lower faces of the blade 2 at the point wherein pins 102 enter the hole of the transversal bridge 203.
Such as shown in figures 6, 7, 8 the connection between the blade 2 and frame members 3 along the side edge of the blade 2 occurs both by means of overmoulding appendices 303 and snap fit pins 102. Particularly it is possible to provide the connection by pins 102 engaged into through holes of the transversal bridges 203 to be carried out at points where the blade 2 has the greatest flexural level, for example at the front end of the footpocket 1, while the connection by overmoulding appendices 303 can be provided for the remaining connection points provided along the longitudinal extension of the blade 2.
Such as shown in figure 12, where one embodiment is shown wherein the perimetral rim member 103 is closed on itself and delimits an inner region which is completely filled with the insert 5¹, the connection between the blade 2 and the frame member 3 occurs at one or more points of the insert 5¹ and/or at least at one of the ends of the rim member 103. Particularly the connection between the blade 2 and the insert occurs by means of one or more pins being inserted into one or more through holes into the wall of the insert 5¹. It is possible for such pins to be provided with a shape subtantially equal to pins described above allowing the blade 2 and transversal connection bridges 203 to be connected and for holes passing through inserts 5¹ to be placed such that during the step manufacturing the fin or when it is used by the user, within the perimetral rim member 103, it is possible to interchange the insert 5¹ with connection bridges 203 or with the resilient filling member composed of perimetral contact branches 403 and of bridges 203. Thus the behaviour of the fin into the water is modified by changing members inserted inside the rim member 103 of the frame member 3 while keeping the same structure of the blade 2.
Obviously the invention is not limited to the embodiment described and shown above but it can be widely varied, above all as regards the structural point of view, without departing from the teaching principle disclosed above and claimed below.

Claims

Swim or diving fin comprising:
- a footpocket member (1) for housing the foot,

- a blade portion (2) extending from the front end of said footpocket member (1),

- at least a frame member (3) extending in the lengthwise direction of the blade (2) and for at least a predetermined portion of the overall length of the blade (2) along at least a longitudinal side edge of said blade (2)
charaterized in that the frame member or members (3) comprise a perimetral rim member (103) closed on itself and having two opposite and spaced longitudinal branches which perimetral rim member (103) delimits an inner hollow region, and it has at one or more points arranged on the length thereof one or more transversal bridges (203) connecting said longitudinal branches, the blade (2) being connected to the frame member (3) at one or more of said transversal bridges (203) and/or at least at one of the ends of the rim member (103).
Fin according to claim 1, characterized in that it has two frame members (103) each one along a longitudinal side edge of the blade (2).
Fin according to claims 1 or 2, characterized in that the perimetral rim member (103) and transversal connection members (203) are made of two materials having different flexibility and resiliency characteristics, particularly the perimetral rim member (103) is made of a more rigid material while transversal connection bridges (203) are made of a less rigid material whose resiliency characteristics correspond to the ones of the rubber or the like.
Fin according to one or more of the preceding claims, characterized in that the edge of the blade (2) is fastened to the frame member (3) at one or more of said transversal bridges (203) by overmoulding appendices (303) of the material of the transversal connection bridges (203) and said appendices, branching off from the side of the bridge faced towards the blade (2), overlap for a certain extension in the lengthwise direction of the blade the upper and lower side of the blade (2) such that the edge of the blade (2) is in a substantially intermediate position between said longitudinal branches of the perimetral rim member (103).
Fin according to one or more of the preceding claims characterized in that said blade (2) is fastened to one or more of said transversal connection bridges (203) by side projections (102) of the edge of the blade (2) engaging, by elastically forcing them, into engagement seats in the wall of the transversal connection bridge (203), for example engaging into a hole passing through the thickness of the transversal connection bridge (203), such that the edge of the blade (2) is in a substantially intermediate position between said longitudinal branches of the perimetral rim member (103).
Fin according to claim 5, characterized in that said side engagement projections (102) of the blade (2) are composed of tapered pins widening towards the engagement end and having a rounded or spherical engagement head and the length of said side engagement projections or pins (102) is such that said side projections or pins (102) project by the rounded head beyond the outer side of the corresponding transversal connection bridge (203) i.e. they project on the opposite side of the blade (2).
Fin according to one or more of the preceding claims, characterized in that there are provided one or more inserts (5) in one or more regions or gaps (503) between two adjacent transversal connection bridges (203) which can be mounted in a movable or fixed manner and said inserts (5) have such a shape to partially or completely fill the gap (503) delimited by two adjacent transversal connection bridges (203) and longitudinal branches of the perimetral rim member (103).
Fin according to claim 7, characterized in that said inserts (5) are made of a material having flexibility or resiliency characteristics different from the ones of materials of the perimetral rim member (103) and/or of transversal connection bridges (203).
Fin according to claim 7 or 8, characterized in that two or more inserts (5) associated to two or more gaps (503) between transversal connection bridges (203) are connected or connectable one to the other by connection brackets.
Fin according to one or more of the preceding claims 7 to 9, characterized in that the insert (5) is mechanically fastened within the corresponding gap (503) by means of anti-slip off mechanical locking means.
Fin according to one or more of the preceding claims 7 to 10, characterized in that inserts (5) are provided with through holes or recesses, particularly on the outer surface, opposite to the one faced towards the blade 2, which through holes or recesses allow the flexible or resilient behaviour of said insert and of the frame member (3) to be modified when at least one insert (5) is coupled to the corresponding gap (503).
Fin according to one or more of the preceding claims, characterized in that transversal connection bridges (203) are a part of a resilient member filling the gap delimited by the inside of the perimentral rim member (103) which resilient member comprises perimetral branches (403) contacting the inner side of longitudinal branches of the perimetral rim member (103) and transversal connection bridges (203) branching off therefrom, at predetermined distances and arranged all along the length of the frame member (3) and said resilient filling member is fastened by a snap fit or it adheres by a chemical physical adhesion to the inner side of the perimetral rim member (103).
Fin according to claim 12, characterized in that in combination with the resilient filling member one or more inserts are provided for regions or gaps between two adjacent transversal connection bridges (203) according to one or more claims 7 to 11.
Fin according to one or more of the preceding claims 1 to 13, characterized in that it has at least one frame member (3) which frame member (3) is provided in a median position of the blade (2) preferably at the central longitudinal axis of the blade (2) the blade (2) being divided into two half-blades each one fastened to one of the two corresponding longitudinal side edges of the frame member (3) and to one or more of the transversal bridges (203) connecting longitudinal branches of the perimetral rim member (103) of the frame member (3).
Fin according to claim 1, characterized in that the inner hollow region delimited by the rim member (103) is partially or completely filled with an insert (5¹) made of a material having resiliency and/or flexibility characteristics different from bridges (203) or from the rim member (103), and said insert (5¹) is mounted within the frame member (3) by a mechanical connection, for example by snap fit means, or by a shape-mating engagement or by chemical physical adhesion such as gluing or by overmoulding, and the connection between the blade (2) and the frame member (3) occurs at one or more points of the insert (5¹) and/or at least at one of the ends of the rim member (103).
Fin according to claim 15, characterized in that each longitudinal side edge of the blade (2) is fastened to the perimetral rim member (103) at one or more points of the insert (5¹) by overmoulding appendices overlapping for a certain width and a longitudinal extension from the inner side, faced towards the blade (2), of the insert (5¹) towards the lower and upper surface of the blade (2) and/or by means of snap fit pins (102) such that the edge of the blade (2) is in a substantially intermediate position between said longitudinal branches of the perimetral rim member (103) and said connection points between the insert (5¹) and the edge of the blade (2) are arranged along the longitudinal extension of the blade (2) at predetermined distances.
Fin according to claim 16, characterized in that the connection between the insert (5¹) and the blade (2) occurs by means of one or more pins (102) branching off from the side edge of the blade (2) engaging by elastically forcing them into one or more through holes provided in the wall of the insert (5¹) and said pins (102) have such a shape and arrangement along the longitudinal extension of the blade (2) to make it possible to interchange, within the perimetral rim member (103), the insert (5¹) with connection bridges (203) and/or with the resilient filling member composed of perimetral contact branches (403) and of bridges (203) according to claims 12 or 13.