Patent GB-1173199-A (GB)
Title: Ski and Method of Manufacture
Inventor: HOLMAN RUDOLPH GEORGE
IPC: A63C5/052
Filed: 1967-03-30
Abstract: 1,173,199. Skis. AMERICAN MACHINE & FOUNDRY CO. 18 March, 1968 [30 March, 1967], No. 14485/67. Heading A6D. A snow ski comprises a core assembly 17 including a light-weight and elongated inner core member 11; and a filament 16 positioned about the core member in a helical pattern along the length of the core member, and an outer surface assembly including an upper surface portion and side surface portions positioned against the core assembly, and, a bottom surface assembly 25 including a plastic running surface and a metal running edge positioned along opposite edges of the running surface, the bottom surface assembly being positioned on the bottom of the ski. The core assembly 17 includes a light-weight polyurethane foam core 11 having one or more binding plates 12 or fibre or metal mounted near the upper surface intermediate the end portions of the core 11 and are designed to anchor the connecting members or screws which secure the ski bindings (not shown) to the ski 10. In addition, a generally Z-shaped anchor member 12' is disposed beneath one of the rear binding plates 12 to receive side screws or the like for anchoring ski bindings from along the side edge of the ski, whereas the plates 12 are adapted to receive top screws or the like. An inner layer 13 of matted glass material and an outer layer 14 of unidirectional glass material are placed about the core 11 and over the binding plates 12 during forming of the core 11. A treated fiber glass winding 16 is then wrapped about the glass layers 13 and 14 in a helical winding pattern which may be varied as desired to impart predetermined characteristics to the ski 10. The separate elements of the core assembly 17 are bonded together in a subsequent molding operation. Both the front and rear portions of the core 11 include formed winding tabs 21 in order to mount the ski 10 during the winding operation, the protruding tabs 21 being removed at a later time. The core assembly 17 is formed by first placing a full length unidirectional strip 14 of glass material in the lower half of a mold 22 and placing a full length strip 13 of glass mat on top of the unidirectional layer 14, see Fig. 15 and is tucked into the corners but extends over the parting line of the mold 22. The binding anchor members 12 and 12' are located in the mold 22 and the components of the polyurethane foam 11 are then mixed and immediately poured into the mold 22. A second strip 13 of glass mat is placed over the foam 11 and a second layer 14 of unidirectional glass is placed thereover. The mold 22 is closed and the assembly is allowed to cure. After curing the excess of the fibreglass mat 13 along the parting line of the mold is trimmed. The resultant core assembly comprises a complete envelope of glass mat enclosing the foam body 11 with the binding anchors 12 and 12' formed in place at the inner face of the mat 13. The top and bottom core surfaces include a full length strip 14 of unidirectional glass exposed at its outer surface. The core assembly is mounted axially by means of the winding tabs 21 at each end on a winding apparatus. One or more fiber glass threads 16, see Fig. 16, which are either pretreated or fed through a resin bath are wrapped about the core in a helical winding pattern about the length of the ski. Means such as spaced pins or staples (not shown) inserted into the side edges of the mold formed core may be provided to prevent thread slippage as the filament 16 is wound about the core. The thread or threads 16 are generally wound in a long helix at an angle of approximately 20 to the longitudinal axis of the ski 10 at the waist or central portion of the ski, and at an angle of approximately 45 at the tail and tip sections, and at an angle of from 20 to 45 in the transitional areas between the waist section and the tail and tip sections. The molded core rotates about its lengthwise axis during the winding operation illustrated in Fig. 16, and a carriage 15 which feeds or lays the filament 16 onto the rotating ski moves back and forth along the ski while the ski is being rotated. The speed of rotation of the ski and the stroke of the carriage are programmed with respect to each other so that the same winding pattern can be successively repeated. Thus, successive skis processed through the winding machine according to a given program tape will have the same characteristics in the final product. In the preferred embodiment of the invention the filament 16 is resin coated just before it is deposited on the molded ski form. After winding the fila ment wound molded ski form 17 is placed in a mold to cure the resin on the filament, to permanently band the filament to each other and to the molded ski form. This provides a ski structure which is completely enveloped or encapsulated by a glass fibre helical winding. After curing of the filament resin then the means, such as not shown side pins, for temporarily holding the helical filament turns in place during the actual winding operation can be removed. As shown, the top surface assembly 20 comprises a plastic material 23 such as polyurethane which is molded in place over the sides and upper and lower portions of the core assembly 17 so as to completely surround and be banded thereto as well as a bottom subassembly 25 described below. The top surface member 23 may be molded separately as a channel-shaped member and then assembled to the core 17. A protective metal edge 24 which is also molded in place along the upper edges of the top surface assembly 20 during mold forming of the plastic 23, is preferably a helically wound wire or coil which prevents top edge damage. The bottom surface assembly 25 comprises a polyurethane running or skiing surface or strip 26 and steel running edges 27 positioned along the outer edges of the plastic strip 26, the parts 26 and 27 being banded to each other by a suitable material 26' such as a soft resilient urethane plastic which completely covers the top of skiing strip 26 to be firmly banded thereto and completely encapsulates the part 27 except for its outer running edge corner, and fills openings 31, 39, formed therein, so as to firmly lock the part 27 in place with respect to the part 26. The running edges 27 may be essentially L-shaped in cross-section and may also include a plurality of elongated apertures 39, see Fig. 10, extending therethrough which include a slot 31, see Fig. 8, extending to the inner portion of the edge 27 at the tip and tail sections of the ski to facilitate bending. The apertures 39 and slots 31 assist in anchoring the edge 27 in position. Other modifications are described employing the core assembly 17 in combination with different top and bottom surface assemblies.