Patent Publication Number: US-7901260-B2

Title: Swimming fin with heel strap fastening buckle

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to articles for self-propulsion and, more particularly, to foot mounted articles for effecting movement through fluid media or the like. 
     BACKGROUND OF THE INVENTION 
     Conventional buckles for swimming fins include, for example, two parts: a first part connected to a side of the shoe and a second part joined to a strap, the first and second parts being in snap engagement with one another. While useful, buckles of this type have been found disadvantageous in that they must necessarily be loosened to enable the fin to be put on the user&#39;s foot, and require adjustment of strap tension each time the fin is put on. 
     A buckle for swimming fins that can be opened without separating it into two separate parts is described in European patent no. 687484 that is inspired by prior solutions already in use in the field of sports equipment. According to this patent the part of the buckle integral with the side of the shoe and the part attached to the end of the strap are articulated to each other via a connection lever that allows the buckle part connected to the strap to be moved from a position of attachment on the buckle part connected to the side of the shoe, at which the strap tightens the foot of the user at the rear, to a position of disengagement wherein the buckle part whereto the strap is attached is moved backwards in relation to the fixed part, eliminating the tension of the strap and thus allowing the user to put the fin on or take it off. With this system it is not possible to separate the parts that make up the buckle, and therefore it is not possible to separate the strap from the fin. Consequently, a first disadvantage of this known device consists in that the user, in order to take the fin off, albeit with the strap loosened, must always remove it from the foot: i.e. it is necessary to make the loosened strap pass behind the heel, with the aid if necessary, of his/her hand, which may delay the operation in emergency conditions. 
     In the buckle described in the aforementioned European patent the buckle part connected to the strap is attached to the buckle part integral with the shoe by means of a snap connection, both during the opening phase and the closure phase, between the intermediate articulation lever and a pair of side flanges rising up from the buckle part integral with the shoe. In order to open the buckle the user has to push the free end of the lever outwards. 
     A second disadvantage of this device consists in that such a closure system is not totally safe, in that the opening movement may also be caused accidentally in the case of impact or in the case wherein the free end of the lever tangles in some external projection. 
     A third disadvantage of this device consists in that, after having worn the fin and closed the buckle, the tension of the strap can be increased but not decreased. With the fin on, the strap provides a tight length adhering to the foot and a free end which can be grasped and pulled to increase the tension of the strap. In order to loosen the tension a few fingers have to be inserted between the foot of the user and the tight strap, which is anything but easy. Therefore, in order to loosen a strap which, once worn, would appear too tight, the strap has to be opened and the adjustment operation repeated. 
     OBJECTS AND SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide a swimming fin with a heel strap fastening buckle that avoids the necessity of loosening the strap to enable the user to put on the fin and then adjust the strap tension. 
     A particular object of the present invention is to provide a swimming fin with heel strap fastening buckle that allows the foot to be removed from the shoe, and therefore from the fin, without the need to have to push the loosened strap under the heel. 
     A further object of the present invention is to provide a swimming fin of the aforementioned type which does not have the risk of accidental opening of the buckle, for example due to an impact, in that the opening of the buckle and its disengagement from the fin require the user to actuate at least one fastening device, acting as a safety actuator. 
     Another object of the present invention is to provide a swimming fin with a heel strap fastening buckle of the type mentioned above wherein it is possible to loosen the strap without opening the buckle by partially rotating a buckle element connected to the strap. 
     These objects are achieved with the swimming fin with a heel strap fastening buckle according to the present invention, said buckle comprising a base plate integral with the shoe, an arm connected to the strap to enable an user to adjust the tension thereof and an intermediate lever pivotally connected to the base plate and to said arm, reversible attachment means being also provided for hooking said intermediate lever to said base plate to achieve closure of the buckle. According to the invention, between the intermediate lever and the base plate disengageable articulation means are provided, for creating reciprocal engagement between them and the pivotal connection and, at the same time, allowing their separation in the direction opposite that of tensioning of the strap, so that the intermediate lever can be separated from the base plate following release of the attachment means and the disconnection of the disengageable articulation means. 
     The disengageable articulation means preferably comprise at least one cavity with an at least partly circular internal profile formed on at least one shoulder rising up from the base plate, said cavity being closed at the side turned towards the arm connected to the strap and open at the opposite side, and at least one projection of the intermediate lever for engaging in said cavity and having a complementary shape to allow reciprocal rotation. In particular, two opposite housings are provided wherein corresponding end portions of the lever pivotally engage, these housings being open at one of their sides, so that the lever end portions can be withdrawn therefrom to separate the lever from the base plate. 
     The means for reversible attachment of the intermediate lever to the base plate preferably comprise at least one first connection element provided on the intermediate lever, which can be snap engaged, during closure, with at least one second complementary connection element formed in the thickness of the base plate. At least one pushbutton, which can be actuated by the user to release the buckle, is provided on the first connection element placed on said lever. In particular the attachment means comprise two hook arms projecting from a face of the lever and elastically urging against each other, while on the base plate at least one window and two opposite, internally projecting teeth are correspondingly provided, said hook arms snap engaging thereon. 
     The hook arms extend from respective pushbuttons between which elastic means are placed for keeping them in a sideways projecting position from the lever. In this position the hook arms are engaged on the teeth of the base plate, while the pushbuttons slide one towards the other transversely to the lever, whereby when the pushbuttons are pressed with the fingers of one hand to overcome the resistance of the elastic means placed between them, it is possible to move the hook arms away from the respective teeth and release the buckle. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A specific, illustrative swimming fin, according to the present invention, described below with reference to the accompanying drawings, in which: 
         FIG. 1  is a partial perspective view of a swimming fin, according to one aspect of the present invention; 
         FIG. 2  is a plan view of the buckle set forth in  FIG. 1 , in a closed position; 
         FIG. 3  is a partial sectional view, taken longitudinally, of the buckle shown in  FIG. 2 ; 
         FIG. 4  is a sectional view taken along line IV-IV of  FIG. 5  showing a buckle base plate integral with the fin; 
         FIG. 5  is a sectional view of the buckle base plate taken along line V-V of  FIG. 4 ; 
         FIG. 6  is a sectional view of the buckle base plate taken along line VI-VI of  FIG. 4 ; 
         FIG. 7  is a plan view of an intermediate lever of a buckle mounted to a swimming fin, according to one aspect of the present invention; 
         FIG. 8  is a sectional view of the intermediate lever taken along line VIII-VIII of  FIG. 7 ; 
         FIG. 9  is a sectional view of the intermediate lever taken along line IX-IX of  FIG. 7 ; 
         FIG. 10  shows a partial, enlarged, longitudinal cross section of a buckle arm integral with the strap, according to one aspect of the present invention; 
         FIG. 11  shows a longitudinal and partial sectional view of the buckle, according to one aspect of the present invention, in a position in which, when the buckle is closed, the buckle arm joined to the strap may be loosened by its partial rotation, a dotted line indicating the arm in a closed, normal working position; 
         FIG. 12  shows a partial, longitudinal sectional view of a buckle, in a first phase of opening; and 
         FIG. 13  shows a second phase of opening the buckle set forth in  FIG. 11  with an intermediate lever, and having the buckle arm integral with the strap released from the base plate and integral with the shoe, according to another aspect of the present invention; 
     
    
    
     The same numerals are used throughout the drawing figures to designate similar elements. Still other objects and advantages of the present invention will become apparent from the following description of the preferred embodiments. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawings and, more particularly, to  FIGS. 1-13 , there is shown generally a specific, illustrative swimming fin  1 , according to various aspects of the present invention. In one embodiment, illustrated in  FIG. 1 , the swimming fin comprises a blade  2  extending from a shoe  3  of a type that is open at the rear end, and a heel strap  4  for securing the fin to a user&#39;s foot. Ends of the strap are preferably connected to respective buckles  5  attached externally to, e.g., sides of, the shoe. 
     As shown in  FIGS. 2 and 3 , the buckle  5  comprises a base plate  6  integral with one side of the shoe  3 , an intermediate lever  7  that can be connected reversibly to the base plate  6  at its front end and articulated to the same base plate at its rear end, and a buckle arm  8  hinged with its front end in an intermediate point of the lever  7  and connected to the strap  4  that extends from its opposite end. The axes of hinging of the lever  7  to the base plate  6  and of the arm  8  to the lever  7 , denoted by X and Y respectively in  FIG. 2 , are parallel. The terms “front” and “rear” refer to the relative position of the fin in relation to the foot of the user. 
     The base plate  6  is attached to the side of the shoe  3  by means of a pin  9  with a butterfly-shaped flange which can be engaged, rotated through 90° in relation to its working position, in a seat  10  correspondingly shaped to allow its anchorage to the base plate  6  and its disengagement therefrom by rotation through 90°. A further stop pin  11 , which can be locked with a special tool, prevents rotation of the base plate from its working position. Stop pin  11  and pin  9  extend from the same face of the base plate  6 . Stop pin  11  engages in a corresponding seat formed on the side of the shoe  3 . 
     Referring also to  FIGS. 4 ,  5  and  6 , from the opposite face of the base plate  6  two opposite side shoulders  12  and  13  rise up. Each shoulder defines, on its internal side, a housing  14  turned towards the other shoulder with a profile that is at least partially circular, closed at its rear side, i.e. towards the arm  8 , and open at its front side. At the two housings  14  two windows  15  are formed on the base plate with the purpose of facilitating engaging and disengaging of the intermediate lever. On the plate  6  two further windows  16  are formed in which respective opposite teeth  17  project whose function will be described herein below. 
     Turning now to  FIGS. 7 ,  8  and  9 , the lever  7  is preferably formed by a front body  7   a . Two arms or articulation members  18  extend rearwardly from sides of the front body, the arms each having an expansion  18   a  with a circular shape at its end. The circular expansions engage housings  14 , as shown in  FIG. 3 , allowing rotation of the lever relative to base plate  6 , in a manner illustrated generally in  FIG. 12 . Because the housings are open on their front side, the circular expansions engage freely with the housings, such that the lever may be completely separated from the base plate in a direction opposite to that of tension of the strap. 
     Due to the fact that the housings  14  have the front side open, the circular expansions  18   a  freely engage in the housings  14  whereby the lever  7  can be separated from the base plate  6  as will be described herein below. 
     Near the opposite end of the lever, relative to the circular expansions, a hand operated lock member is provided, the lock member comprising a pair of push-buttons  19  projecting laterally from opposing sides of the lever body and sliding transversely relative thereto. According to one embodiment, the lock member also includes hook arms  20  extending from the push-buttons, respectively, toward the base plate for engagement with teeth  17 , described above, which project into windows  16  of the base plate. An arrangement of this general description is illustrated in  FIGS. 4 and 5 . As shown in  FIG. 8 , a spring  21  is positioned between the push-buttons and extends generally transversely into a seat of lever body  7   a  so as to maintain them in an externally projecting position. In this manner, when the hook arms are engaged with the teeth, the lever is joined securely to the base plate. By pressing the push-buttons simultaneously, such as using two fingers of one hand, in a direction shown by arrows F in  FIG. 8  to push them toward one another, the elastic resistance of spring  21  is overcome and hook arms  20  are caused to disengage from teeth  17 , thereby releasing intermediate lever  7  from base plate  6 . The intermediate lever can then attain the position shown in  FIG. 12 . In a subsequent position, shown in  FIG. 13 , the buckle is completely open and disengaged from the fin. 
     Referring to  FIGS. 2 ,  3  and  10 , the arm  8  for connection to the strap is formed at its rear side by a substantially box-shaped portion  8   a , in which one end of the strap  4  engages, and by a wing  22  extending from its opposite end between the arms  18  of the lever  7  and articulated to the lever  7  through a pin  23 . As shown in  FIG. 10 , the strap  4  is engaged as usual in the box-shaped portion  8   a  of the arm  8 , in particular being wound on a transverse pin  24  placed therein. The box-shaped portion  8   a  also comprises a pushbutton  25  hinged on a second transverse pin  26  also placed in the box-shaped portion  8   a . A tooth  27  extends from the internal face of the pushbutton  25  to engage between the ribs of the strap  4  allowing the locking thereof in the required position, while on the diametrically opposite side between the pushbutton  25  and the box-shaped portion  8   a  a spring  28  is placed to force the tooth  27  against the strap  4  and prevent sliding of the strap. The state of tension of the strap  4  is adjusted as usual by pressing the pushbutton  25  in the direction of the arrow F 1  so as to overcome the elastic resistance of the spring  28  and disengage the tooth  27  from the transverse ribs of the strap  4 , which can therefore be slid freely around the transverse pin  24  to loosen it or tensioning it. It should in fact be noted that in the position of the arm  8  shown in  FIG. 11  the buckle remains integral with the fin; nevertheless it is possible to loosen the strap. 
       FIGS. 3 ,  12  and  13  show how the buckle mounted on the fin of the invention works, when the buckle is to be opened without altering the tension of the strap. In particular, it is noted that in order to change from the condition shown in  FIG. 3 , wherein the buckle is closed and the lever  7  is connected to the base plate  6 , to that shown in  FIG. 12 , wherein the lever  7  has been released from the base plate  6  by disengaging the hook arms  20  from the respective teeth  17  of the base plate  6 , it is necessary to press the pushbuttons  19  with two fingers of the same hand. In  FIG. 12  the intermediate lever  7  is released at its front end from the base plate, but is still articulated to the latter at its rear end; by disengaging the circular expansions  18   a  of the arms  18  of the lever  7  from the housings  14  of the base plate  6  the buckle is completely opened as shown in  FIG. 13 . It will be noted that, although the articulation between the base plate  6  and the lever  7  through the circular expansions  18   a  engaged in the housings  14  is an unrestrained connection, this would in any case be ensured by the state of tension of the strap  4  which, in the conditions of  FIG. 3 , in fact prevents disengaging from the housing  14  except in the case of accidental impact which could bring the intermediate lever  7  into the position shown in  FIG. 12 . According to the invention this risk is avoided with the reversible attachment device formed by all the elements  17 ,  19 ,  20  and  21 , which can only be opened deliberately by the user. 
     Various modifications and alterations may be appreciated based on a review of this disclosure. These changes and additions are intended to be within the scope and spirit of the invention as defined by the following claims. For example, the reversible attachment member, formed by elements  17 ,  19 ,  20  and  21 —that can be actuated using two fingers of the same hand via opposing push-buttons  19  and thereby act as a safety device, may be replaced by a single push-button located transversely, or in a front central part, of lever  7  and, in any case, preferably in a position where it is protected from accidental impact.