A swim fin including a scoop member made from a stiff plastic material molded to a shoe member made from a soft synthetic elastomer, the scoop member having a planar portion forming a half-sole for the shoe; projections, recesses and apertures being formed on the scoop member for providing an additional mechanical bond between the scoop member and the shoe member.
Having thus described my invention, I claim
1. A swim fin comprising a scoop member made from a relatively stiff plastic material molded to a shoe member made from a relatively soft synthetic elastomer, said scoop member having two side webs laterally surrounding at least the fore end of the shoe member, the upper edge of each side web having an inwardly extending rim, said side webs having at least one side opening and at least one vertical bore passing through the side webs' upper rim through which the molded shoe material on the outer surface of the shoe side wall penetrates, said scoop member having a planar portion coextensive with and extending substantially longitudinally of the front sole portion of the shoe member and extending laterally between the side webs to thereby form a half-sole portion for the shoe member, said planar portion of the scoop member having recesses and projections in its upper surface engaging the lower surface of the shoe sole, whereby the molded shoe material on the lower surface of the shoe sole penetrates the recesses on the sole portion of the scoop member, and the projections thereon are embedded into said lower surface of the shoe sole, thereby providing an additional mechanical bond between the scoop member and the shoe member.
2. A swim fin according to claim 1, in which the shoe member is moulded on the scoop member so as to partially overlap the scoop member at the junction edges.
BACKGROUND OF THE INVENTION
The present invention relates to swim fins of the kind comprising a shoe portion and a scoop portion integral therewith. It is known that in order to achieve the best propulsion results in a swim fin it is necessary that the scoop portion be relatively rigid and elastic, whilst the shoe portion should have a certain flexibility and pliability in order that it may adapt itself to the foot without exerting any kind of abrasive friction on the foot.
These different requirements cannot be satisfied by manufacturing the shoe and scoop portions of the swin fin of the same material.
It has been proposed, as shown for instance from the U.S. Pat. No. 3,302,222, to produce separately the shoe portion and the scoop portion from different materials, providing the said portions with complementary coupling means for interconnecting the said portions.
A composite swim fin of the kind disclosed in the above mentioned Patent is difficult to be produced due to the difficulty of providing it with the complementary coupling means; it requires a subsequent assembly step of the two parts of the fin, and is therefore costly.
It is therefore the main object of the present invention to obviate to the drawbacks of the prior art fins of the kind comprising a shoe portion made of a material different from that of the scoop portion.
SUMMARY OF THE INVENTION
According to the invention, a swim fin is provided comprising a scoop member made from a relatively stiff plastics material, and a shoe member made from a relatively soft synthetic elastomer, the said shoe member being moulded directly on the said scoop member, the said scoop member being provided at the junction areas with the shoe member with projections, recesses and/or through passages for providing an additional mechanical bond between the scoop member and the shoe member being moulded on it.
Further features and advantages of the swim fin of the invention will be disclosed in the detailed description thereof which is given hereinbelow with reference to the accompanying drawings showing a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal section through a swim fin according to the invention.
FIG. 2 is a longitudinal sectional view of the rear portion of the scoop member of the swim fin according to the invention.
FIG. 3 is a top plan view of the rear portion of the scoop member of FIG. 2.
FIG. 4 is an enlarged perspective view of the particular of one of the side webs of the rear end of the scoop member.
FIGS. 5 and 6 are vertical sections taken along the lines V--V and VI--VI of FIG. 2, before the moulding of the shoe member on the scoop member.
FIGS. 7 and 8 are vertical sections corresponding to FIGS. 5 and 6, after the moulding of the shoe member on the scoop member of the swim fin.
DESCRIPTION OF THE INVENTION
The swim fin shown in FIG. 1 comprises a scoop portion 1, made from relatively stiff plastics material, and for instance from Ethylene-Vinylacetate copolimer and a shoe portion 2 made from a relatively soft rubberlike material, and particularly from a mixture of a copolymer of ethylene-vinylacetate and thermoplastic rubber, which shoe portion is moulded, for instance by an injection moulding process, on the previously formed scoop portion, so as firmly adhere to it.
The shoe portion is provided, at the toe end with an aperture for the passage of the toes, whilst at the heel end it is provided with a pull-on strap 3.
The rear end portion 4 of the scoop member 1 is formed as a sole for the shoe member 2, and extends for about the half of the length of this member. The rear edge 6 of the terminal portion 4 of the scoop member 1 is V shaped, as clearly shown in FIG. 3. The scoop member 1 is further provided with longitudinally extending side webs 5, the height of which is increasing toward the rear end of the scoop member. In the rear portion of the scoop member 1, the side webs 5 extend upwardly from the terminal portion 4 of the scoop member 1, so as to laterally surround the shoe member 2, to which they become firmly bonded during the moulding of the shoe member 2 on the scoop member 1.
At the front zone of the rear portion 4 of the scoop member 1 a recess 7 is formed. At the rear edge 6 of the scoop member 1 a number of upwardly projecting pin-like members 8 are integrally formed. During the moulding of the shoe member 2, the moulded shoe material penetrates the recess 7, whilst the projections 8 are embedded into the material of the shoe member. In this manner, in addition to the welded bond between the scoop member and the moulded shoe member, an additional mechanical bond is provided between the said parts.
The side webs 5 of the scoop member 1 are provided at their upper end with an inwardly projecting rim 9. The upper corner portion 10 of the side webs 5 is stepped down, and at this corner an oblique opening 11 is formed in the side webs 5. At a position slightly in advance of the said opening 11, a vertical boring 12 is formed through the rim 9, as shown in FIGS. 3 to 6.
The shoe member is moulded on the scoop member 1 in such a manner as to rest under the rim 9, and to cover the stepped-down corner portion 10 of the side webs 5. The material of the shoe portion 2 fills the lateral openings 11 and the vertical borings 12, as clearly shown in FIGS. 7 and 8. In this manner at the corner portions 10 of the side webs 5 a particularly firm bond between the scoop member and the shoe member is obtained. The rear portion of the shoe member, which freely projects from the scoop member 1 joins laterally and at its bottom flush with the scoop member 1. Of course, the said shoe member may be moulded on the scoop member so as to partially overlap the scoop member at the junction edges.