Articulated attachment means for swimming fin

A swim fin having manually articulable water-channeling vanes. A swim fin attachable to a human extremity such as a foot has a front portion through which a plurality of holes are present. Circumscribing these holes are corresponding clock washers that provide intermittent stops when engaged by a complementing clock washer. Such a complementing clock washer is present in a water channeling vane that is affixed over the clock washers of the swim fin by a bolt that passes into a bore (which may be threaded) within the vane. Upon full threading of the vane upon the bolt, the complementing and opposing clock washers come into close contact with one another whereby the ridge of one clock washer fits into a corresponding furrow of the other. The vane is then temporarily locked into place with respect to the swim fin, however this temporary lock is overcome by rotational pressure generally available from a human hand. An alternative embodiment, the swim fins may be retrofitted for affixation of such water channeling vanes by means of a template in which holes are present that correspond to the appropriate position for holes in the swim fin. Clock washers may be attached as by adhesive to the swim fin, or may contact the swim fin through mutually roughened or knurled surfaces to increase the friction therebetween. In use, the vane can be adjusted in any direction by turning the vane with respect to the swim fin.

CROSS-REFERENCE TO RELATED APPLICATIONS 
This application is an improvement upon International Application number 
PCT/US92/09002 having an international filing date of Oct. 26, 1992. Said 
application is incorporated herein by this reference thereto. 
BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to swimming fins, and more particularly to water 
channeling vanes attachable to such swim fins whereby the flow of water 
about the fin can be usefully controlled and altered. 
2. Description of the Related Art 
Until the development of the swim fin having multiple interchangeable 
components of the parent application, no swim fins were known that could 
be made more resistive or more propulsive or both, depending upon the 
swimmer's needs. In the parent application, such swim fins were disclosed 
that carried water-channelling vanes that directed and controlled the flow 
of water about the fin. However, as shown in FIGS. 3a, 3b, and 3c of the 
parent application, the means by which the water channeling vanes of the 
parent application were connected to the swim fin blade were very static 
in nature and difficult to adjust manually while being worn in the water. 
This lack of adjustability prevents minor but significant adjustments of 
the vane so that the water about the swim fin may be channeled in an 
easily selectable manner. Without such adjustment, the person wearing the 
fins may be forced to endure forces or stresses from the swim fin that 
might be better distributed or directed elsewhere. 
Furthermore, if the swim fin is used for more than one individual, 
different individuals will have different preferences with respect to the 
attitude of the water-channeling vanes. Particularly, when used in 
hydrotherapy, a therapist may have a single set of fins that is used by a 
number of individuals. Making the vanes more easily adjustable will 
enhance and improve the hydrotherapy sessions for both the therapist and 
the patient. 
Also, the swim fin with the water channeling vanes may be used under a 
variety of circumstances that require adjustment of the vanes. Without the 
ability to easily adjust such vanes, the utility and advantageous nature 
of the vaned swimming fin is reduced. 
For these and other reasons, there is a need for modifying the swim fins in 
the parent application such that they are more easily adjustable in a 
convenient manner. 
SUMMARY OF THE INVENTION 
The present invention provides easily adjustable water channeling means for 
swim fins. A swim fin attachable to an extremity such as a person's foot 
has a front portion about which a series of holes are present at the 
vertices or at other useful locations. The holes allow bolts or other 
attachment means to pass through them to attach water channeling vanes to 
the swim fin. In order to prevent slipping of a water vane with respect to 
the swim fin, and also to provide means by which the water channeling vane 
can be movably held in place, a series of opposing and engaging stop means 
such as ridges are disposed between the water channeling vane and the swim 
fin. Once secured to the swim fin, the water channeling vane can be 
articulably and pivotally rotated with respect to the swim fin, with 
individual positions of the vane controlled by the detent-like movement of 
the vane with respect to the swim fin. 
Preferably, a clock or timing washer provides an intermittent stop means by 
which the water channeling vane can be moveable positioned in a 
position-retaining manner. Once set into place, the water channeling vane 
is not easily displaced from its chosen position. The increased surface 
area of the ridged washers and the ridges themselves provide the present 
invention with its position-retaining ability. 
Generally, the ridged contact surface of the water channeling vane is 
integral to it, the ridges being cast or molded in a one piece unit 
conjoined with the vane. With respect to the swim fin, its clock or timing 
washer can be integrally cast or molded with the swim fin, or individual 
clock washers can be used on the top and bottom sides of the swim fin. Use 
of individual clock washers is contemplated in conjunction with 
retrofitting a swim fin with the vanes of the present invention. 
In order to allow easy retrofitting of a swim fin, thereby allowing use of 
the present invention, a template is used to establish the correct hole 
positions for the vane-attaching bolt. Generally, the template matches the 
blade portion of the swim fin and has one portion that fits within the 
foot channel of the swim fin so as to correctly position the template. 
Upon installation, the water channeling vane is adjustable by taking it in 
hand and twisting it clockwise or counterclockwise until the correct vane 
position is established. The engaged ridges of the clock washers serve to 
hold the vane in place until repositioned again by the swimmer's hand. 
From the above, it can be seen that an object of the present invention is 
to provide adjustable means for water channeling vanes in a swim fin. 
It is another object of the present invention to provide such adjustable 
water channeling vanes that are easily adjustable. 
It is another object of the present invention to provide easily adjustable 
vane means for a swim fin that are easily constructed. 
It is a further object of the present invention to provide means by which a 
swimming fin that otherwise has no water channeling vanes can be 
retrofitted to bear such vanes. 
These and other objects and advantages of the present invention will be 
apparent from a review of the following specification and accompanying 
drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT(S) 
The present invention resides principally in a swim fin having adjustable 
vanes for controlling the flow of water over and about the swim fin. The 
channeling of water over the swim fin provides means by which drag, 
propulsion, resistance and force can be constructively and directionally 
altered depending upon the desired operational characteristics of the swim 
fin. 
Previously, adjustment of water channeling vanes was inconveniently 
achieved as a bolt attaching the vane to the blade of the swim fin had to 
be tightened sufficiently so that no movement of the water channeling vane 
could take place once the bolt was tightened down. While this tightly 
attached relationship between the swim fin blade and the vane prevented 
the vane from detaching from the blade, no adjustment of the vane with 
respect to the blade could occur. The present invention allows means by 
which such water-channeling vanes can be easily adjusted, yet will not be 
displaced by the flow, even very turbulent flow, of water over the swim 
fin. 
As shown in FIG. 1, a clock or timing washer structure 10 provides the 
preferred means by which such adjustable positioning is achieved. The 
clock or timing washer 10 of FIG. 1 generally has a flat disk 12 upon 
which a series of ridges 14 circumscribe the perimeter. In the center of 
the disk, a hole 16 is created so that a bolt or other means of attachment 
may pass through the center of the clock washer. The ridges 14 of the 
clock washer may be angled inwardly so that the outermost edge of the 
ridges are taller than the innermost height of the ridges. This creates an 
indentation effect whereby the entire structure slopes towards the center 
and the hole 16. Alternatively, the ridges 14 may be uniform in height, or 
even angled outwardly so that the innermost edge of the ridges are taller 
than the outermost height of the ridges. In this sense, the angle of the 
ridges 14 may be respectively negative, neutral or positive. As the angels 
of the ridges may be selected, it can be seen that the ridge height closer 
to the center compare to the ridge height farther from center. 
The same inward sloping effect (or similar alternative ridge configuration) 
may be used on a complementary and opposing clock washer so that the ends 
of the ridges are interengaged with the peaks of one washer nestled in the 
troughs of the other, and vice-versa. Alternatively, the complementary and 
opposing clock washer may be chosen or selected to only partially engage 
the ridges of the corresponding clock washer. 
When the clock washers are made of resilient and flexible material, the 
engaged ends of the ridges can be flexed and temporarily deformed to allow 
rotation of the two complementing and opposing washers with respect to 
each other. Alternatively, only one clock washer need be made of resilient 
and flexible material. The corresponding clock washer may be rigid and 
inflexible as when constructed of hard plastic or metal. In such a case, 
one washer will supply the flexibility necessary to allow the vane to turn 
with respect to the swim fin. 
The swimming fin of the present invention may be similar to that of the 
parent application, serial number PCT/US92/09002 with an international 
filing date of Oct. 26, 1992, that parent application is incorporated 
herein by this reference thereto. To briefly summarize that swimming fin 
as set forth in the parent application (shown in FIG. 4), a truncated 
swimming fin 18 has a tunnel or channel 20 for a swimmer's foot flanked on 
opposing sides by a pair of arcuate-shaped flaps 22a, b. Each 
arcuate-shaped flap has a pair of holes drilled therethrough through which 
a binding may be laced to thereby lash the swimming fin 18 on the person's 
foot. 
Alternatively, and as set forth in more detail below, a swimming fin of 
conventional design may be retrofitted to include the vanes or winglets as 
set forth herein. 
The arcuate-shaped flaps 22a, b flank the rear portion 24 of the swimming 
fin. From the rear portion 24, the swim fin 8 then flares out into the 
front portion or blade 26 generally parallel to the wearer's foot. The 
rear portion 24 may be roughly rectangular or otherwise shaped as is most 
useful or advantageous for the particular fin. In one embodiment, the 
front portion or blade 26 may be roughly trapezoidal, but in other 
embodiments may be of other useful or advantageous shapes. Together, the 
rear portion 24 and the blade 26 are the sole plate 28 of the swim fin 18. 
At the vertices of the front portion 26 are corresponding holes 30 that 
are circumscribed by an attachable 10 or integral 32 clock washer 
structure previously mentioned. Alternatively, holes 30 may be formed or 
drilled elsewhere on the fin 18 where the ability to attach a vane and 
thereby control the adjacent flow of water is desired. Further, other 
alternative means of attachment may be used to connect the vane to the 
swim fin. Clamps or adhesion as are known in the art may be used to 
connect the vane to the swim fin. 
The swim fin of the present invention is approximately a quarter of an inch 
thick and is made of known swim fin material such as rubber, polyurethane, 
silicones, or other such materials. As shown in FIG. 3, traction ribs or 
cleats 34 are provided by the swim fin 18 beneath the heel portion 24 of 
the swim fin. These protuberances may also be selectively located in known 
areas of drag resistance to create vortices that relieve such drag. 
Preferably, such protuberances are knob-like in nature. 
As shown in FIG. 2, the water channeling vane 36 of the present invention 
has a protruding water channeling portion 38 hereinafter referred to as 
the vane fin 38. Below the vane fin 38 and connected thereto is the body 
40 of the vane, beneath which a flat surface 42 provides some clearance 
for the attached swim fin 18. Centrally located on the flat underside 42 
of the vane 36 is a mounting hole or bore 44 which is preferably threaded. 
Threads 46 of the bore 44 match those of a bolt which may be used to 
attach the vane 36 to the swim fin 18. The bore 44 leads out from the core 
of the vane body 40 ending in an aperture 48 that is circumscribed by 
clock washer ridges 50. These ridges 50 provide intermittent stop means 
that are used to articulably control and position the vane 36 with respect 
to the swim fin 18. 
As indicated by FIGS. 2. 15, and 16, the vane protrudes into the 
surrounding area in a manner generally parallel to the major axis of the 
associated bore. 
Alternatively, when the vane is constructed of a strong, resilient material 
such as polyurethane, pre-threading of the bore may not be necessary. By 
providing a bore slightly smaller in diameter than the screw to be used to 
attach the vane to the swim fin, the material within the hole of the vane 
will conform to the threads of the screw. Similarly, the screw may cut its 
own threads into the vane bore when first driven into the vane. 
As shown in FIG. 5, a template 52 corresponds closely to the sole plate 28 
of the swim fin 18. Holes 54 are present in the template 52 that 
correspond to the holes 30 in the blade 26. The template fits over the 
sole plate 28 of the swim fin 18 and as shown in FIG. 6, allows holes 30 
to be properly positioned for drilling into the blade 26. As a drill bit 
will not generally be hindered in its passage through rubber, it is best 
to make a permanent template 52 out of a more resilient material such as 
metal or durable ceramic. However, for most consumer purposes, a temporary 
template is sufficiently adequate to convey the benefits of the present 
invention. Templates made of paper, Mylar, plastic, cardboard or other 
like material may be entirely acceptable for the positioning of the holes. 
Such templates may be left on the fin during drilling, or can be used to 
simply mark the location of the holes which are then drilled out. 
Once the holes 30 have been drilled into the swim fin blade 26, clock 
washers 10, such as that shown in FIG. 1, can be used and attached to the 
swim fin blade 26. The clock washers 10 circumscribe the holes 30 drilled 
by the use of the template 52. As shown in FIG. 3, once the holes 30 have 
been drilled into the swim fin blade 26, the swim fin 18 is then ready for 
the attachment of the clock washers 10 and the vane 36. The right most 
portion of the drawing of FIG. 3 shows the attachment structure of the 
clock washers 10 and vanes 36 by means of a bolt 56 to the swim fin. As 
shown, the vane 36 is attached generally perpendicular to the plane of 
blade 26. 
In order to ensure that the vane 36 pivots with respect to the 
corresponding swim fin clock washer 10, an adhesive or other friction 
enhancing material or structure (such as a knurled or roughened surface) 
can be used between the swim fin clock washer 10 and the swim fin blade 
26. In this way, when the vane 36 is turned, the underlying swim fin clock 
washer 10 will not turn with the vane 36. 
As shown in FIG. 3, a bolt 56 or other attachment means may be used to 
affix the vane 36 to the swim fin blade 26. The threads of the bolt 56 
match the threads 48 of the vane 36, thereby connecting the vane 36 to the 
blade 18. 
In order to construct a retrofitted swim fin, the template 52 is used as 
previously described, whereby the hole 30 positions are properly located 
when the template 52 is placed over the blade 26. The drill is then passed 
through the holes 54 of the template 52, drilling out the blade surface 
beneath the template holes 54. Surface roughening or knurling can then be 
created around the drilled out holes 30. If clock washers 10 are to be 
permanently affixed to the swim fin blade 26, an adhesive can be used 
between the clock washer 10 and the perimeter area circumscribing the 
holes 30 of the swim fin blade 26. Alternatively, surface knurling or 
roughening may provide enough friction between the clock washer 10 and the 
swim fin blade 26 to ensure that the clock washer 10 does not turn with 
the vane 36. 
As shown in exemplary form in FIG. 3, a bolt 56 is passed through a first 
clock washer 10 with the ridges 14 of the clock washer 10 facing the bolt 
head 58. The bolt 56 is then passed through the swim fin blade 26 and a 
second clock washer 10. The ridges 14 of the second clock washer 10 face 
away from the bolt head 58 and toward the vane 36 with its complementing, 
integral clock washer ridges 50. The vane 36 is then threaded onto the 
bolt 56 until it comes into contact with the underlying blade clock washer 
10. As shown in FIG. 3, clock washer structures may be present on both the 
upper and lower sides of the swim fin blade. If desired, a headless bolt 
(not shown) can be used that is threaded at both ends so that oppositely 
opposing vanes can be used on both sides of the swim fin blade. 
Alternatively, clock washer structures can be placed not only on both 
upper and lower sides of the swim fin, but on either the upper or lower 
side alone. 
Once the swim fin blade has been retrofitted with the clock washers, it 
operates in the same manner as a swim fin with integrally constructed 
clock washers. 
As for those clock washers 32 that are integrally constructed with the swim 
fin blade 26, once the bolt 56 is run through the blade hole 30, the vane 
36 can be threaded onto the bolt 56 until it can no longer be easily 
turned onto the bolt 56 and there is snug contact and engagement between 
the ridges 32, 50 of the opposing clock washers. In the preferred 
embodiment, there are three hundred sixty degrees (360.degree.) of 
rotation possible between the vane 36 and the swim fin 18. 
When the vane 36 is turned (like a wing nut) upon the bolt 56, the 
complementing ridges tend to force the vane 36 and blade 26 away from one 
another, simultaneously flexibly deforming the interengaging ridges. Upon 
the application of sufficient force (generally available to a human hand), 
the clock washer ridges 50 of the vane 36 will shift over one position 
with respect to the clock washer ridges 32/14 of the swim fin blade 26. 
When the rotating force of the swimmer's hand is released, the vane 36 and 
its clock washer ridges 50 seat themselves on the swim fin blade 26 and 
its clock washer ridges 32/14 in very snug engagement. 
While the clock washer ridges 14/32 may project above the surface of the 
structure to which they are attached, contemplation of recessed clock 
washers is also made. Such recessed clock washers allow for a flush 
surface between the vane 36 and the swim fin 18. Recessed clock washers 
can be safer when diving in environments where kelp, filaments, or other 
entangling strands or flora may be present in the water. Recessed clock 
washers suffer less drag than exposed clock washers, especially when a fin 
fitted for articulable water-channeling vanes is used without such vanes. 
Recessing the clock washers also prevents accidental abrasion from exposed 
surfaces (such as swimming pool surfaces, rocks or coral) when the clock 
washers are exposed due to removal of vanes. 
Due to the strength of the force required to articulate the vane 36 with 
respect to the blade 26, it would be an unusual and infrequent occurrence 
for the flow of water to be able to create such a specifically directed 
force. As the present invention is contemplated for use in water and other 
fluids, the interengagement of the opposing clock washers provides 
sufficient means by which the vane can be held in place with respect to 
the swim fin blade. The detent-type movement between the vane and blade by 
means of the clock washers is both useful and elegant. A swimmer 
encountering such a device for the first time should not have difficulty 
putting it into use, allowing the swimmer to conveniently adjust the vanes 
of the fin according to present needs and/or wants. 
As shown in FIG. 7, the vanes of the present invention may take the form of 
winglets 102 that extend forwardly from the blade 104 of a swim fin 106. 
Such winglets may be retro-fitted to conventional or other accommodating 
swim fins by means of mounting plates (FIGS. 8, 9 and 17) bearing clock 
washers. The template 108 may be used to properly indicate the position 
where holes must be drilled through the swim fin blade 104 in order to 
accommodate the screws or bolts used to attach the mounting plates and the 
vanes or speed pods of the swim fin to be retrofitted. Such templates will 
generally have three holes: two for the screws or bolts attaching the pair 
of mounting plates to each other and one for the vane or speed pod. The 
vane or speed pod hole is centrally located in the mounting plate and 
between the other two holes. 
As shown in FIGS. 7 and 15, the vane winglet of the present invention has a 
rounded, slightly protruding portion 110 to better engage the nut 112 
encased within its interior and to provide initial streamlining to the 
oncoming flow of water. The vane winglet 102 may be attached at one end to 
a mid-portion of the underlying swim fin. The vane winglet 102 then 
extends in a streamlined manner towards the furthest reach of the swim fin 
blade. 
The vane winglet 102 has a marked curvature as it approaches the attachment 
point 114 from its furthest extent 116. This curvature is present 
predominantly near the attachment end 114 of the vane winglet 102, with 
the greatest portion of the winglet travelling in a predominantly straight 
manner. The outer side 116 of the vane winglet closest to the side of the 
swim fin is latitudinally curved towards the inner side 118 of the vane 
winglet. The inner side of the vane winglet is predominantly perpendicular 
to the underlying swim fin, as is the outer side which establishes its 
curve generally towards the top 120 of the vane winglet. The longitudinal 
curve of the vane winglet near the attachment area 114 is curved inwardly 
towards the fin 106. Another slight curvature may be present towards the 
furthest extent of the vane winglet, the curvature being slightly outward 
and away from the fin. 
The height of the vane winglet 102 is somewhat dependent upon the size of 
the fin and a larger vane winglet is needed where large amounts of water 
are moved by generally large swim fins having a large surface area. 
Correspondingly, where smaller fins move a smaller volume of water and 
such swim fins have a smaller effective area, smaller vane winglets are 
needed. Generally, the vane winglet 102 will stand above the swim fin 106 
so as to effectively change the flow of the surrounding water stream. This 
generally means that the layers of water that adhere or that are effected 
by contact with a swim fin when water flows over the swim fin are 
negligible with respect to the water channeled by the vane winglet 102. 
Furthermore, the effect of the vane winglet 102 should be significant when 
compared to the entire flow of water generated by the kicking of the swim 
fin 106 by the swimmer. 
As travel is made from the front portion of the vane winglet (near the 
point of attachment 114 to the swim fin) to the rear of the vane and 
furthermost extent of the vane winglet 116, the bottom of the vane winglet 
122 tapers inwardly so as to create a thinner cross-section as the vane 
winglet 102 travels away from the point of attachment 114. The vane 
winglet also tapers at its end 116 somewhat upwardly at an angle slightly 
steeper than that of the downward taper from the top of the vane winglet 
120. In general, water flowing past the vane winglet 102 first encounters 
a large structure where the vane winglet is attached to the swim fin 114 
and then redirected in a turbulence-mediating manner by the tapering 
extension of the vane winglet 102. 
Examples may be given of positions available for the vane winglet 102 as 
attached to a swim fin 106 as shown in FIG. 7. In a first position, the 
tapered vane winglet extension runs generally parallel to the side of the 
swim fin 124 with the front tapered end of the vane winglet 102 pointing 
inwardly towards the interior of the swim fin. 
In a second position, the forward tapered end of the vane winglet 102 is 
parallel to the side of the swim fin 124 with the tapering rear extension 
of the vane winglet pointing in a direction inwardly towards the rear of 
the swim fin 106. This second position provides increased water channeling 
and direction centering to the water so that greater propulsive effect is 
created with each kick of the swimmer. 
In a third position, the outer side of the tapered front end of the vane 
winglet 102 is generally parallel to the side of the swim fin 124, whereas 
in the second position the tapered end pointed in a direction parallel to 
the side of the swim fin. The tapered extension towards the rear of the 
vane winglet 116 points at an even greater angle towards the interior 
surface of the swim fin blade 104. This third position provides the 
greatest amount of thrust and propulsion to the swimmer with each kick. 
As shown in FIG. 17, 3-slotted clock washers 126 can be used to provide the 
3-position articulable and discrete positioning for the vane winglet 102 
with respect to the swim fin 106 as set forth above. Of course, readily 
available 360.degree. clock washers could also be used although most of 
the available angles of the 360.degree. clock washer could not be used. 
Under some circumstances, the shape of the vane winglet 102 could be seen 
as similar to that of a whale with a broad front and a tapering rear, but 
without the transverse tail, making a turn by pivoting about its pectoral 
fins or what might be considered to be its "shoulders". 
FIGS. 8 and 9 show a corresponding pair of mounting plates as contemplating 
in the present invention. Beginning first in the mounting plate shown in 
FIG. 8, the generally circular plate 128 has lobed opposing ends 30a, b, a 
sloped perimeter and a recessed central portion 134. Holes are present 
central to the lobes (not shown) that allow the passage of screws or bolts 
136a, b therethrough. Such screws or bolts 36 may be recessed into the 
lobes 130 or may protrude above the surface of the plate 128. Inside the 
central recessed portion 134 is a central hole 138 through which a screw 
may pass to connect a vane or speed pod to the swim fin 106. Encircling 
the circumference of the central hole and extending to the outward edges 
of the recess is a clock washer structure 140 with alternating peaks 142 
and troughs 144. This clock washer structure 140 matches a similar 
structure in the attached vane or speed pod. 
FIG. 9 shows a corresponding terminal mounting plate 146 that serves to 
hold the mounting plate 128 in FIG. 8 to the swim fin 106 and to provide a 
connection between the swim fin 106 and the attached vane 102, 36 or swim 
pod. Like the clock washer mounting plate 128 in FIG. 8, the terminal 
mounting plate 146 of FIG. 9 is generally circular in nature having a 
sloped perimeter 148 and opposing lobed ends 150a, b with holes central to 
the lobes 152a, b formed therethrough. Furthermore, there is a central 
aperture 154 corresponding to the similar one 138 in the washer mounting 
plate. These holes or apertures serve as means by which the bolts 136 of 
the washer mounting plate may pass through the terminal mounting plate 146 
and be subsequently secured thereto by means of nuts 154a, b or the like. 
The lobe nuts 154 of the terminal plate serve to connect the two mounting 
plates 128, 146 to the swim fin 106, establishing a stable foundation upon 
which the vane or speed pod can be mounted to the swim fin 106. A screw or 
bolt connected to the vane or swim pod is passed through the mounting 
plates and the swim fin between them. This screw is then fitted with a nut 
in order to secure the bolt and the attached vane or speed pod to the swim 
fin. 
Alternatively, the use of a terminal mounting plate may not be necessary as 
a second clock washer mounting plate 128 may be used in opposition to a 
first one so that articulable structures may be installed on both sides of 
the swim fin. Such an arrangement is shown in FIG. 16 where a speed pod 
156 and vane winglet 102 are shown on both sides of the swim fin 106. 
Under such circumstances, a long screw having no head may be used to 
connect the two structures on opposite sides of the swim fin 106 and 
mounting plates 128, 146. 
FIGS. 10 through 14 show in cross-section a number of structures 
contemplated as a part of the present invention. FIG. 10 shows in 
cross-section the connection of the two mounting plates 128, 146 of FIGS. 
8 and 9 on opposing sides of the swim fin blade 104. As shown in FIG. 10, 
the head of the bolts may be recessed, but it should be understood that in 
an alternative embodiment the heads may be exposed. Likewise, the bolts on 
the terminal mounting plate on the bottom side of the fin may have 
recesses for the bolts or, alternatively, the bolts may be exposed and 
protruding from the exterior of the terminal mounting plate. 
In FIG. 11, the clock washer section 158 is exposed and protrudes from the 
exterior of the mounting plate 128. Under some circumstances, such a 
configuration may be of some advantage to a swimmer or a diver. FIG. 12 
shows a recess 160 such as one that can be used to accommodate a nut or 
bolt head so that the nut or bolt head does not protrude from the exterior 
surface of or about the recess. 
FIGS. 13 and 14 show a speed pod 156 used in conjunction with the mounting 
plates 128, 146 of the present invention. The speed pod 156 has a 
hemispherical cross-section on the lateral plane and an oval cross-section 
in a longitudinal plane so that the speed pod 156 has a pear or tear drop 
shape which protrudes from an exterior surface of the swim fin 106. The 
edges of the speed pod 162 may be formed so as to continue a slope 
initially present at the edges of the mounting plates 132. In this way, 
water flow may be affected by the speed pod 156 while minimizing turbulent 
flow arising from discontinuities present between the mounting plate 128 
and the speed pod 156. 
It is known that there is a dead spot in the middle of the underside of any 
fin. There may be other dead spots at other areas on a swim fin. 
Therefore, a speed pod 156 is also provided as part of this invention to 
alleviate drag or other resistance created by dead spots. The speed pod is 
shaped like a streamlined hemisphere: in other words it has a tear drop 
shape. The speed pod may be any convenient size and may be made from high 
density foam, or solid plastic. It can even be filled with a heavy 
material such as lead. Use of the speed pod, by diverting water from dead 
spots, will enable the swimmer to swim faster. The pod may be made of foam 
to keep the swimmer's feet high in the water. If the pod is made from a 
dense solid plastic or is filled with lead, it will make the swimmer's 
feet sink, thus making his legs work harder. Neutrally or almost neutrally 
buoyant speed pods may also be used. 
As shown in FIG. 15, a nut 112 or other similar object is encased in the 
vane winglet 102. This encased nut 112 provides attachment means for the 
vane winglet 102 to the swim fin 106. When a bolt, screw or other similar 
object is passed through the mounting plates 128, 146, it can be threaded 
through the encased nut 112. When the other, free end of the bolt is 
secured, the vane winglet 102 or other attachment may then be secured to 
the swim fin 106. 
Once the mounting plates 128, 146 have been installed, the vane winglet 102 
can be threaded upon the bolt so that the clock washer structure 164 
present on the vane winglet 102 can enmesh with that 140 of the clock 
washer mounting plate 128. When the bolt or screw is sufficiently 
tightened, the clock washers 140, 164 will snugly seat themselves against 
one another thus constraining the rotational movement of the vane winglet 
102. As before with the simple vane fin 36, the clock washers allow 
articulated movement of the vane winglet 102 with respect to the swim fin 
106 in discrete angular positions. In one embodiment, the clock washer 
structure on either or both the vane winglet and clock washer may have a 
limited number of ridges so that the angle through which the vane may turn 
is correspondingly limited. Such a limited ridge clock washer is shown in 
FIG. 17. 
In FIG. 17, and like the mounting plate shown in FIG. 8, the generally 
circular plate has lobed opposing ends 160a, b, a sloped perimeter 162 and 
a recessed central portion 164. Holes that are present central to the 
lobes that allow the passage of screws or bolts 166a, b therethrough. Such 
screws or bolts may be recessed into the lobes 160 or may protrude above 
the surface of the plate 126. Inside the central recessed portion is a 
central hole 168 through which a screw may pass to connect a vane or speed 
pod to the swim fin 106. Partially encircling the circumference of the 
central hole 168 and extending to the outward edges of the recess 164 is a 
partial clock washer structure 170 with alternating peaks 172 and troughs 
174. This clock washer structure partially matches a similar structure in 
the attached vane or speed pod. 
FIG. 16 shows the use of articulating attachments on the other side of a 
swim fin using clock washer mounting plates on both of its sides. The 
clock washers may be inherent or integral with the swim fin or may be 
present due to the use of mounting plates as previously described. 
The pairs of mounting plates can be associated in a number of different 
manners. As there are three different kinds of mounting plates (full 
washer 128, terminal 146, and limited washer 126), these may be associated 
in pairs in as many as nine different combinations. For example, a 
360.degree. clock washer mounting plate 28 may be on one side of the swim 
fin with another 360.degree. clock washer mounting plate on the other 
side. A 3-slot clock washer mounting plate 126 may be on one side and a 
3-slot clock washer mounting plate on the other. Also a 3-slot clock 
washer mounting plate may be on one side with a 360.degree. clock washer 
mounting plate on the other. Furthermore, a terminal mounting plate with 
no clock washer 146 may be on one side of the swim fin with either a 
360.degree. or a 3-slot clock washer mounting plate on the other. 
When a swim fin has been fitted with the vane winglets 102 or whiskers as 
shown in FIG. 7, an increase propulsive power is supplied by the swim fin 
to the swimmer. As the winglets are angularly articulated about the bolt, 
the water flowing past the swim fin 106 is increasingly channeled towards 
the center of the fin. As more water is channeled toward the center of the 
fin by the winglets, it must flow faster across the fin in order to 
equalize the pressure applied by the fin to the surrounding water. As the 
water both flows faster across the fin and as the faster flow is channeled 
towards the center of the fin in a direction opposite to the fin, more 
propulsive power from the swimmer's kick is used to propel the swimmer 
rather than creating turbulence in the water about the fin. 
While the present invention has been described with regards to particular 
embodiments, it is recognized that additional variations of the present 
invention may be devised without departing from the inventive concept.