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US 4,259,274 AGranted
Method and apparatus for making a laminated ski
AssigneeKarhu-Titan Oy
InventorAntti-Jussi Tiitola
Life of this patent
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AssigneeKarhu-Titan Oy
InventorAntti-Jussi Tiitola
Estimating the term…
A ski which has a sandwich structure including upper and lower plastic laminations and a foamed plastic core situated therebetween with dense side portions integral with the upper and lower laminations and forming a shell surrounding the foamed core has in its new finished condition the same condition as when the ski is removed from a mold, so that finishing operations are not required subsequent to removal of the ski from the mold. The mold which is used to manufacture the ski has opposed relatively wide walls and a pair of opposed relatively narrow walls which are permanently fixed to one of the relatively wide walls while the other of the relatively wide walls is movable to and from an operating position closing the mold and cooperating with the relatively narrow walls for this purpose. The relatively wide walls have inner surfaces directed toward the interior of the mold to define part of the mold cavity, and against these inner surfaces the upper and lower laminations of the ski are held by a suitable holding structure so that the foamable plastic can be injected into the mold between the upper and lower laminations to become bonded integrally therewith while forming the dense side portions along the inner surfaces of the relatively narrow mold walls. According to the method, the mold downwardly extends in its longitudinal forward direction at an angle to the horizontal so that gravity forces can be employed in order to promote a complete filling of the core space within the mold with foamable plastic material. The upper lamination of the ski, which preferably is narrower than the lower lamination thereof, is first placed in the mold, after being completely finished, while being held in place by an adhesive tape which in addition to holding this upper lamination in the mold serves to protect the finish thereof, the lower ski lamination being situated against the inner surface of the movable mold wall and held thereagainst during the injection of the foamable plastic. According to the method, when the foamable plastic has cured to form the core, the ski structure is removed from the mold, and no further surface-finishing operations are required.
A method for manufacturing a ski having upper and lower plastic laminations and a foamed plastic core situated between and bonded to said laminations in a mold having side surfaces defining an elongate mold cavity having a front end region which extends downwardly so as to form an upwardly extending front ski tip portion and a rear end region for forming the rear ski portion, comprising the steps of situating the upper lamination in the interior of a mold next to and extending along the lower inner surface of the mold, situating the lower lamination in the interior of the mold in spaced overlying relationship to said upper lamination, with said mold having opposed inner side surfaces extending between side edges of the laminations situated in the mold, and injecting into the spaces between said laminations and said mold side surfaces a foamable plastic which foams and cures in the interior of the mold while forming a foamed core having next to said side surfaces of the mold dense side portions which become integral with the laminations and define therewith a shell in which the foamed core with an interior portion of lesser density than said side portions thereof is situated, and removing from the mold said ski in a completely finished condition having said laminations bonded to said foamed core.
A mold for molding a ski having upper and lower laminations and a core of foamed plastic situated therebetween and forming a sandwich construction therewith, comprising opposed relatively wide upper and lower elongate mold wall members having a pair of longitudinal end regions for forming the front and rear ski portions and a pair of opposed relatively narrow elongate mold side wall members situated between said upper and lower wall members, said side wall members being permanently fixed to said lower wall member while said upper wall member is movable to and from an operative position with respect to the side wall members defining therewith and with said lower wall member a mold cavity the cross-sectional configuration of which corresponds to the cross section of the finished ski in the upside down configuration, said upper mold wall member having an inner surface facing said lower mold wall member and having a configuration which corresponds to that of the lower lamination so that the latter can be placed contiguous therewith prior to injection of a foamable plastic into the mold cavity, while said mold side wall members are spaced from each other at their regions which are fixed to said lower mold wall member by a distance suitable for receiving between them the upper ski lamination, and wherein said lower mold wall member has an inner surface facing said upper mold wall member and has a configuration which corresponds to that of the upper lamination so that the latter can be placed contiguous therewith prior to injection of the foamable plastic into the mold cavity to form the core between said laminations, said end regions of said upper and lower wall members which form the front ski portion extend downwardly to define a ski front tip portion which extends upwardly when the ski in its right side up configuration, and means for fixing said laminations in the interior of the mold with the lower lamination engaging and extending along said inner surface of said upper mold wall member and with the upper lamination situated between the mold side wall members at the region where they are permanently fixed to said lower mold wall member.
Dependencies are inferred from the claim text.