DE2128725A1 - Swim fin - Google Patents

Description

No. k6 06I

The invention relates to swim fins attachable to the foot, as used by sport swimmers, scuba divers, professional divers and others to speed up and improve the effectiveness of propulsion through the water.

According to US Pat. Nos. 3,032,767, 3,055,025 and 3,133,529, it has already been proposed to provide passages and openings or channels running through the blade in the blade of a swimming fin in order to achieve advantages such as, for example, increased drive, reduced vortex formation and reduced drag.

However, in no event has it been suggested to use water jets to crzeussüii, following from the tip of the leaf extend outside in directions away from the foot pocket. In particular, in no event has it been suggested to water from the top surface adjacent to the foot pocket of the sheet "lurch Uauäl ;: zu Wasserauslaß- or; <: iÄ.scrstrahlauslaßöffiiimgciJi to direct, Avelche formed in the leaf tip and are directed away from the dex ^ foot pocket. Such Bayerische Vereinsbank Mündien 820993

109851/0213

The arrangement of the water jet outlets has great advantages which will be described later.

The swim fin has a blade that when propelled of the swimmer through the water, means for attaching the blade to the foot of a swimmer and channels and outflow openings, which upon a downward movement of the foot of a downward moving swimmer cause jets of water from the tip of the blade in from the foot exit directions running away. In particular, fc are adjacent to the inner end of the foot pocket in the upper part of the Sheet formed a relatively large space occupying water scoop or mouth openings, and in the tip of the leaf are water outlet or water jet outlet openings, which occupy a relatively small space. From the inlet openings to the water jet outlets extend through the sheet of the, fin outflow channels, their cross-sectional areas on the water jet outlets to decrease so that a high speed water jet discharge is effected.

An embodiment of the invention is described below with reference to the figures. From the figures ψ show:

Figure 1 is a representation shown partly as a side view and partly as a longitudinal section, with the swim fin on the downward moving foot one with the Face-down swimmer attached;

FIG. 2 shows a plan view of the swimming fin of oTaen;

FIG. 3 shows a central longitudinal section along the line 3-3 of FIGS. 2j and

Figures cross-sections along lines 4-- ^; i bz ^T >. ·. 1 and ρ 5-5 of Figure 2.

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In the description, the term "upper side of the blade" means that part of the fin blade which is at the top, when the fin-bearer is on the ground. Likewise, the term "underside of the sheet" means that part of the Swimming fin, which is at the bottom when the fin bearer is on the ground. It's just a swim fin besclurieben, whereby it goes without saying that the swim fin for the other foot is identical or essentially identical to the swim fin described. All fi © ireri with the exception of Figure 1 show the swim fin in their natural state (unstressed and not flexed).

As shown in FIGS. 2 and 3, the swim fin has a sheet 10, which by fastening means 11 to a Foot 12 (Figure 1) of a swimmer is attached. The fastener 11 is constructed so that the sheet is generally in a plane perpendicular to the wearer's leg when the fin bearer is on the ground or another wing. Then that extends Blade away from the wearer's ankle, in line with and outwardly of the instep and toes.

It is desirable that the fastening means 11 has a wall 13 to form a foot pocket or chamber Ik which receives the toes and instep of the foot 12. It should be noted that additional walls, not shown, can be provided which enclose the ankle and / or the heel.

In the embodiment shown, a heel strap runs 15 (Figure l) around the wearer's heel and is adjustable by means of Connecting means connected at its ends with strap lugs or buckles 16 which are integrally attached to the Sides of the wall 13 are formed.

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Lateral ribs 17 are provided along the side edges of the sheet 10 and the wall 13. The end sections of the lateral ribs 17 are, as Figure 2 shows, generally parallel to one another, but the central portions of the Ribs diverge considerably, in a direction moving away from the ankle of the wearer. To this The blade 10 is considerably wider than the fastening means 11.

Between the front sections of the lateral ribs 17 ^ intermediate ribs 18 are provided at the same distance from one another. These ribs run parallel to one another and to the front from the wall 13 'which forms the foot pocket 14; d. H. the intermediate ribs J.8 run from those receiving the toes Divide the wall 13 forward. In the embodiment shown two such intermediate ribs IS are provided, and the distance between these ribs is approximately equal to the distance between each diesel rib and the respectively adjacent side rib 17

In addition to the various ribs, the blade 10 has a bottom wall 20 that encompasses the entire bottom and front portion the swim fin covered. This bottom wall 20 ^ runs on a thickened portion 21 (Figure 3) in the Bottom part of wall 13 The bottom wall 20 thus extends to wall 13 for the purpose of forming the foot pocket.

An upper wall 22 is provided at a distance from the lower wall 20 and covers the entire area of the swim fin 10, which lies in front of the edges 23 of the upper wall shown in FIGS. 2 and 3. These edges 23 are a considerable distance in front of the wall 13.

According to Figures 4 and 5, both the upper and the lower wall 22 and 20 in one piece with all ribs 17 and

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formed, these ribs serving to keep the walls 20 and 22 spaced from each other. The ribs 17 and 18 run not only between the walls, but also above and below them, so that the rib thickness is enlarged and deflection means are also provided for guiding the water when this along the outer surfaces the walls 20 and 22 flows.

As FIG. 4 shows, the ribs 17 and 18 are relatively large and strong in areas close to the wall 13. From these strong sections, the ribs taper continuously towards the front and become narrower, as FIG. 5 shows. This causes the walls 22 and 20 to converge progressively closer to one another, and also the sheet portions remote from the foot pocket are more flexible than the sheet portions adjacent to the pocket.

The walls 20 and 22 and the ribs 17 and 18 work together to form three outflow channels 24, 25 and 26 (Figures 3-5). The channel 24 is generally rectangular in section and is between the side rib 17 and the adjacent intermediate rib 18 and formed between the sections of the upper and lower walls 22 and 20, which are between said Ribs extend. Correspondingly, the channel 26 is between the other side rib 17 and the one adjacent to it Intermediate rib 18 and between the wall sections 20 and 22 which extend between said ribs, educated. The middle channel 25 is between the two intermediate ribs 18 and between the upper and lower wall sections 22 and 20 extending between these ribs are formed.

Since the walls 22 and 2O in the vicinity of the wall 13 a have a relatively large distance from each other, the outflow channels 24-26 in the vicinity of this wall 13 have relatively large cross-sectional areas. The cross-sectional areas of the channels 24-26 progressively decrease in one of

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the direction away from the wall 13 and become extremely small near the tip of the blade (i.e., near the Areas farthest from the ankle of the fin stretcher removed). Therefore, in Figure 5, each of the channels is 24-26 shown as being relatively wide but narrow (i.e., there is only a small distance between opposing Wall sections 20 and 22 available).

The ends of the channels that are remote from the wall 13 24-26 form water outlet or water jet outlet openings 27 (Figure 3) that of the wall 13 immediately away and after are directed forward. In other words, these water jet outlet ports 27 generally direct the water into the Level to the top of the sheet 10 and away from the wearer's foot and ankle.

The other ends of the outflow channels 24-26, namely the ones closest to the wall 13, form water inlet or inlet openings 20. The water inlet openings 28 are directed generally upwards when the fin carrier is on a base, ie these openings are directed upwards and form an angle of about 90 with respect to the water jet outlet openings 27j when the fin carrier is on a base. When the fin bearer swims face down through the water, the downward kick of the legs and feet causes water to enter the inlet openings 28 and then undergo a gentle curve (formed by the wall portions 29 and 30 in Figure 3) to the tip areas of the sheet where the water exits through the water jet outlet openings 27. Not only does the water flow through the gentle curve, but it is accelerated very rapidly due to the progressively decreasing cross-sectional areas of the channels 24-26 so that three high speed water jet outlets are formed from the tip of the blade and away from the ankle of the wearer.

The entire swim fin with the exception of the heel strap 15 and the associated fastening means is molded in one piece from an elastomeric material, for example made of natural rubber or synthetic rubber. The elastomer Material should be sufficiently strong so that excessive deformation is avoided. For example, the Shore hardness about 70. The swim fin according to the invention has the advantage that it can be shaped in a simple manner despite the presence of the channels 2Ί-26.

The mode of action of the finding according to the swim fin is' explained with reference to Figure 1 in which the fin is attached to the foot 12 of a wearer who is faced swims down. Figure 1 shows the condition which occurs when the fin support advances through the water and at the same time hits the foot and the leg part shown in the drawing downwards, the direction of impact indicated by arrow C.

The illustrated downstroke creates thrust and also areas of relatively high pressure of 1 atm and 2 at along the downward facing surface of sheet 10, i.e. H. on and along the top wall 22. Dei "downstroke also causes some upward deflection of the sheet, especially at those sections that are relatively near the apex (i.e. at portions remote from wall 13).

Simultaneously with the occurrence of the downstroke, as indicated by arrow C, the swimmer moves forward through the water, thereby resulting in a backward flow of water along the leaf walls 22 and 20, as indicated by arrows 31 and 32, respectively. Such Forward movement of the swimmer is the result of the stroke action, where this blow ex'-proves two important effects, as described below.

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UD 2756

The first effect is the immediate thrust of the leaf wall 22 against the water. When the fin is in the is in the position shown in Figure 1, such a thrust has a vertical and a horizontal component, · The latter is effective in producing a Propulsion of the swimmer through the water. It should be noted that the horizontal component of the direct thrust am largest is near the high pressure area H.P.l, there the portion of the wall 22 adjacent to this area is sharp runs upwards. Conversely, there is a very small horizontal component of the direct thrust in the vicinity of the ™ high pressure area H.P.2, since the fin in the figure 1 shown position is only very slightly inclined in this area.

After the fin has moved down (from the position shown in Figure 1) until all of its sections are generally horizontal, there is very little or no horizontal component of direct thrust.

The second effect is different from the direct thrust effect described above and is jet thrust. the The jet thrust effect results from the fact that the practically k "non-working" area in the vicinity of the area H.P «2 is converted into a useful jet pump. Such a "pump" causes water to flow through the channels 24-26, as the arrows 33 show, with a consequent jet thrust effect at the blade tip. Also reinforced Such a pump controls the flow along the flat surfaces, as the arrows 31 and 32 indicate.

The water inlet openings 28 at the front ends of the outflow channels 24-26 are generally in the direction of blade movement due to the action indicated by arrow C. .Indicated downward stroke directed. This is the case because the water inlet openings 28 in a direction transverse to the

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Plane of the sheet 10 run (Figure 3) · Therefore, the high pressure in the area of H.P.2 extremely effective and causes a flow (arrows 33) into and through the outflow channels 24-26. The water entering these channels flows around a gentle curve (surfaces 29 and 30) and then takes effect accelerates (along paths generally in the plane of the sheet 10) until it is at high speed exits through the water jet outlets 27. Such an acceleration results from the continuously decreasing Cross-sectional areas of the channels 2 ^ -26 when they approach the outlet openings 27. The outlet direction of the water jets runs away from the wearer's foot and ankle, i.e. H. away from the fastening means 11.

The jets of water discharged through the outlet openings 27 generate a considerable thrust force with a main horizontal component, resulting in increased propulsion of the float in the forward direction. It should be noted that this _r jet thrust is still present when the swim fin is generally horizontal, ie, in a time when little or no direct thrust leads, as described above.

Since the water jet outlets are at the tip of the blade 10, a drag effect is created, whereby the Flow along the surfaces of the blade (indicated by arrows 31 and 32) is increased. That as Viasser rays emerging from the openings 27 (upper arrow 33 in FIG. 1) Water takes with it the water flowing backwards from the leaf walls and 22 (arrows 31 and 32). A such entrainment creates an area of relatively low pressure adjacent the blade tip, and a such an area of low pressure makes it easier for water to flow backward away from the leaf walls. It follows that there are three layers of water jets away from the tip of the blade, as shown by the arrows above to 33 is indicated, and these three layers of water jets

1Q9S51 / Ö213

UD 2756 - 10 -

increase the driving effect that moves the float.

In addition, the jets of water emerging from the channels 2k to 2.6 in the tip of the blade serve to minimize the formation of eddies and whirlpools that are present at the tip of the blade as a result of the beating activity. This results in a greater drive power.

Since the water jets emerge through the openings 27 arranged in the tip instead of through the lower wall 20, results a relatively larger thrust in the horizontal (useful) direction. For example, in Fig. 1 is the top one Arrow 33 far closer to the horizontal than each corresponding one representing the flow through the lower wall 20 Arrow would be. On the other hand, the water jet outlet is found as shown by the uppermost arrow 33 in FIG is not held to an area of high pressure, as it would be if the water were to be in the H.P.I. area adjacent through the top wall 22 would emerge. However, this does not mean that the openings arranged in the tip 27 not from the plane of the pointed area of the sheet 10 could be inclined away. For example, you can use run inclined in a direction which is somewhat opposite to that shown in FIG. 1, resulting in a reduction of the angle between the uppermost arrow 33 and the horizontal results.

It should be noted that the water jets emerging from the openings 27 are directed into the main body of water and not against or near any part of the fin itself. In the prior art, existing ones stepped Water jets essentially in a forward direction with respect to the tip area of the fin, which the decreased propulsive power generated by the water jets.

During the upward stroke of the swimmer's foot, which is not shown, relatively little driving force is generated,

109851/0213

and it vi3 "d done relatively little effective work. It should be noted, however, that the entire obex'e (in FIG. 1) F ¹ IHcIIe of the leaf, ie the bottom edge 20 _; would generate a drag.

Patent claims:

109851/0213

Claims (1)

P a t c η t a η s ρ r ü c h e / 1.) Swimming fin, characterized by a blade (10) for propelling a swimmer through the water, by means (11, 3-3) provided at one end of the blade (10) for attaching the fin to the foot of a swimmer water inlet means (28) provided on the top of the blade (10) and arranged to receive water when the swimmer's foot moves downward when the swimmer is face down, the water inlet opening being cn ( L.8) are relatively close to the fastening means (11, 13) by at the other end of the sheet (10) of üeu Bi-Festiguiigymittelii (ll, 13) oppositely arranged water jet outlet openings (L7) which are arranged so that the water in a direction away from the fastening means (11, 13), and through channels (24, Jp, k; 6) which lead us water from the water inlet openings (kö) to the water jet outlet openings (27) for delivery through the latter. 2ο swim fin according to claim 1, characterized in that the. Water jet outlet openings consist of outlet openings (ü7) provided at the extreme tip of said other end of the blade (10), said tip being the part of the blade (10) furthest from the fastening means (11,13). 3 · Swimming fin according to claim 1, characterized that the channel means have at least one outflow channel (24, 25, 26) through the sheet (10) and that the walls of the outflow channel (24, 25, 26) are designed so that an acceleration of the Water inlet means (28) to the water jet outlet openings (27) flowing water is effected. 109851/0213 k. Swimming fin according to claim 3 »characterized in that the outflow channel (24, 2p, 26) has a cross-sectional area which progressively extends in the direction of the water outlet opening (27) and over substantially the entire distance from the water inlet means (28) to the water jet outlet openings (27) decreases. 5. Swimming fin according to claim 1, characterized in that the inlet opening (28) of the Water inlet means is transverse to the plane of the sheet (10). 60 swim fin according to claim 5 »characterized by this t, that the walls of the outflow channel have gently curved sections (29, 30) which indicate the direction of flow of the water from a direction transverse to the plane of the leaf (10) to a direction in the plane of the Change the direction of the leaf (10). 7. Swimming fin, characterized by a foot pocket (14) defining walls (I3) »through the first and second lateral ribs (17) which extend forwardly from the walls (13) forming the foot pocket, wherein at least parts of said side ribs (17) diverge relative to one another in one of those forming the foot pocket Walls (I3) leading away direction, by between the first and second rib (17) arranged ribs (l8), the from the walls (13) forming the foot pocket extend in front, through one with the side ribs (17) uid the Upper wall (22) connected to intermediate ribs (18), which forms the surface of the blade (10) of the fin, and which in near the walls (13) forming the foot pocket on inner part of the fin ends, namely in inner edges (23) »the spacing in front of the walls forming the foot pocket (13) lie, and by a with the side ribs (17) and the intermediate ribs (l8) connected lower wall (20), which the un- 109851/0213 underside of the leaf (lO) forms the fin and of the Upper wall (22) extends at a distance, with at least parts (21) of the lower wall (20) forming the foot pocket Walls (13) extend and the upper (22) and lower (20) wall with the side ribs (17) and the intermediate ribs (l8) cooperate to form a plurality of water outflow channels (24-26), each of these channels (24-26) running out at its inner end into a water inlet opening (28) which is defined in part by one of the inner edges (23) of the top wall (22), and each of the channels (24-26) at its The outer end discharges into a water jet outlet opening (27) located at the extreme tip of the sheet (10) between the outermost outer edge of the upper wall (20) and the lower wall (22) is formed, said opening (27) in one of the walls (13) forming the foot pocket runs away in the direction. 80 swim fin according to Anspx "uch 7» thereby g e ■ - * ■ indicates that the "upper (22) and lower (20) wall converge in a direction away from the walls (13) forming the foot pocket, whereby a progressive Acceleration of the water flowing from the water inlet opening (28) to the water jet outlet opening (27) is effective. 9. Swimming fin according to claim 8, characterized in that the first and second ribs (17) and the intermediate ribs (18) in a direction leading away from the walls (13) forming the foot pocket rejuvenate continuously. 10. Swim fin according to claim 8, thereby marked t 'that the part of the bottom wall (20) which is closer to the walls (13) forming the foot pocket than said inner edges (23) of the upper wall (22), is concave and the water from the water inlet openings (28) 109851/0213 to the water jet outlet openings (27) around a curve. lic swimming fins according to claim 7j, characterized in that they form the foot pocket Walls (I3) »the side ribs (I7), the intermediate ribs (18) Are the upper wall (22) and the lower wall (20) in one Pieces are molded from a single mass of elastomeric material. 12. Swimming fin according to claim 7 »characterized in that the first and second ribs are g e k e-ji η ζ e i c h η e t (17) and the intermediate ribs (l8) have sections that are located above and below the upper wall (22) or the Lower gate wall (20) extend and serve to move the water along the outer surfaces of the upper wall (22) and the lower wall (20) to lead. 13. Swim fin according to ArtS claim 7, thereby marked ζ e lean t that the intermediate ribs off two spaced apart parallel ribs (ΐδ) exist. 14. A swim fin according to claim 7 _t characterized in that the cross-sectional shape of each Wasserausströmkanals (24-26) is rectangular. 15c swimming pool according to claim Ik _1, characterized in that said cross-sectional shape is wide in the area between the ribs (17> 18) and in the area between the upper wall in areas of the blade (10) remote from the walls (13) forming the foot pocket (22) and the lower wall (20) is narrow «, 109851/0213