Title:
SKI AND METHOD OF MANUFACTURE
United States Patent 3635482


Abstract:
A new and improved snow ski and a method of making said ski. The ski comprises a plastic foam core surrounded by one or more fiber glass layers and a predetermined fiber glass winding. A unique top surface assembly including a coiled spring edge and a bottom surface assembly, the various embodiments of which are described hereinafter, are then mounted about the core assembly to form a finished ski.



Inventors:
HOLMAN RUDOLPH G
Application Number:
05/056089
Publication Date:
01/18/1972
Filing Date:
06/29/1970
Assignee:
AMF INC.
Primary Class:
Other Classes:
156/242, 156/245, 273/DIG.8
International Classes:
A63C5/048; A63C5/052; A63C5/12; (IPC1-7): A63C5/12
Field of Search:
280/11.13 156
View Patent Images:



Foreign References:
FR1351207A1964-01-31
FR1380102A1964-11-27
FR1435153A1966-04-15
Primary Examiner:
Hersh, Benjamin
Assistant Examiner:
Smith, Milton L.
Parent Case Data:


This application is a continuation of application Ser. No. 705,706 filed Feb. 15, 1968, now abandoned.
Claims:
What is claimed is

1. A snow ski comprising:

2. A snow ski comprising:

3. A snow ski in accordance with claim 2 wherein:

4. A snow ski in accordance with claim 3 further including:

5. A snow ski in accordance with claim 2 wherein:

6. A snow ski in accordance with claim 5 wherein:

7. A snow ski in accordance with claim 2 wherein:

8. A snow ski in accordance with claim 7 wherein:

9. A snow ski comprising:

10. A snow ski according to claim 9, wherein the core is reinforced with fiber glass.

11. a snow ski according to claim 10, further comprising:

12. A snow ski according to claim 10, wherein a metallic binding plate is embedded in the reinforced core.

13. A snow ski according to claim 9, wherein said core is reinforced with:

14. A snow ski according to claim 9, wherein the urethane layer includes portions forming the sides of the ski.

15. A snow ski according to claim 9, wherein the coating of the coated fiber glass filament is epoxy.

16. A snow ski comprising:

17. A snow ski according to claim 16, wherein the flanges of the metal running edges are provided with apertures and portions of the urethane plastic are placed in the apertures.

18. A method of making a snow ski, comprising the steps of:

19. A method of making a snow ski according to claim 18, further comprising the step of reinforcing said foam core with fiber glass before winding the fiber glass filament therearound.

20. A method of making a snow ski according to claim 18, wherein said fiber glass filament is epoxy coated and is wound about said reinforced foam core in a helical pattern.

21. A method of making a snow ski according to claim 18, wherein said step of bonding the bottom surface assembly to the filament-wound reinforced foam core comprises forming a layer of plastic at least partially around the filament-wound reinforced foam core.

22. A method of making a snow ski according to claim 21, wherein said plastic is a urethane or the like.

23. A method of making a snow ski according to claim 18, further comprising the step of curing the wound, reinforced foam core before the bottom assembly is bonded thereto.

24. A method of making a snow ski, comprising the steps of:

Description:
This invention relates to a new and improved snow ski and a method of making said ski. The growing popularity of winter sports such as skiing caused manufacturers to devote more attention to technical problems affecting ski performance. Considerable effort has, consequently, been devoted to developing new ski designs which represent a marked improvement over the prior art. However, despite the advances which have been made, the manufacture of skis generally requires a great number of manual operations which necessarily increase product cost. Furthermore, the characteristics or properties of commercially available skis are often deficient in one or more respects as attempts are made to compromise between various design factors.

The present invention relates to a new and improved ski which is superior in performance to present high-quality skis and also lower in cost. In addition, the unique ski comprising this invention readily lends itself to mass production methods which permit further economies.

SUMMARY OF THE INVENTION

The object of this invention is to provide a new and improved ski and a method of manufacturing said ski. The ski thus produced is light in weight and is of a predetermined strength and thickness. As a further advantage, it is possible to build a ski having the desired characteristics at a lower cost than conventional skis.

The unique ski of the present invention comprises a plastic foam core having a predetermined fiber glass covering and a separate fiber glass winding to produce the desired properties in the finished product. A top assembly including a coiled spring outer edge and a bottom assembly are then bonded to the core assembly to form the finished ski. The invention in its various embodiments includes a number of novel top and bottom assemblies which are mounted about the core. Since the various manufacturing operations may be readily adapted to mass production techniques, the subject skis may be produced at a lower unit cost.

BRIEF DESCRIPTION OF THE DRAWINGS

The features of the present invention will be more clearly understood when viewed in conjunction with the accompanying drawings wherein:

FIG. 1 is a top view of the unique ski comprising the present invention;

FIG. 2 is a side view of the subject ski illustrating the configuration of said ski;

FIG. 3 is a cross-sectional view taken along the line 3--3 of FIG. 1 showing the tip section of the ski;

FIG. 4 is a cross-sectional view taken along the line 4--4 of FIG. 1 illustrating the tail section of the ski;

FIG. 5 is a cross-sectional view taken along the line 5--5 of FIG. 1 showing the construction of the ski tip portion;

FIG. 6 is a cross-sectional view taken along the line 6--6 of FIG. 1 showing the waist portion of the ski;

FIG. 7 is a cross-sectional view taken along the line 7--7 of FIG. 1 illustrating the construction of the tail portion of the ski;

FIG. 8 is a view showing the tip protector mounted on the tip portion of the ski;

FIG. 9 shows the coil spring upper edge employed in the preferred embodiment of the ski;

FIG. 10 is a top view of a typical L-shaped running edge employed in the preferred embodiment;

FIGS. 11-16 illustrate the unique core structure of the subject ski and its method of manufacture with the various views being as follows:

FIG. 11 is a cross-sectional view of the core assembly;

FIG. 12 is a broken-away perspective view of the core assembly to better illustrate its various elements:

FIG. 13 is a view of the molded core prior to winding;

FIG. 14 is a view of a typical binding plate;

FIG. 15 illustrates the positioning of the various core elements within a mold for forming the polyurethane core structure;

FIG. 16 illustrates the winding operation wherein a fiber glass thread is wrapped about the molded core in a predetermined pattern, and;

FIGS. 17-24 illustrate various other embodiments of the invention employing the wound fiber glass core illustrated in the foregoing figures. The different embodiments are described at length in the specification.

FIG. 25 is an isometric view of another embodiment of a ski according to the invention.

FIG. 26 is a sectional view of the ski shown in FIG. 25.

FIG. 27 is an isometric view of a reinforced core for the ski shown in FIGS. 25 and 26.

FIG. 28 is an exploded view of the ski shown in FIGS. 25 and 26.

FIG. 29 is an enlarged view of a portion of the ski shown in FIG. 28.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings, the present invention comprises a new and improved ski 10 which includes a core 11 of material such as polyurethane foam having one or more binding plates 12 and a plurality of fiber glass layers 13 and 14 positioned thereover and a fiber glass winding 16 wrapped thereabout in a predetermined pattern. The above components comprise the core assembly 17 which remains essentially the same for the various embodiments of the invention. This core assembly 17 is combined with a top and side surface assembly and a bottom surface assembly to form the completed ski shown in FIGS. 1 and 2.

The core assembly 17, which is illustrated in greater detail in FIGS. 11-16, includes a lightweight polyurethane foam core 11 having one or more binding plates 12 mounted near the upper surface intermediate the end portions of the core 11. The binding plates 12 may be of a fiber material or a metal such as aluminum. The binding plates 12 are designed to anchor the connecting members or screws which secure the ski bindings (not shown) to the ski 10. It is to be understood, of course, that the binding plates 12 may differ somewhat from the configuration of FIG. 14 and may comprise one or more separate elements. In addition, a generally Z-shaped anchor member 12' is disposed beneath one of the rear binding plates 12. This anchor member 12' is for the purpose of receiving 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. This means that the ski of the invention can receive almost any type of ski binding currently available on the marketplace. The Z-shape imparted to the member 12' has the additional advantage that it can be readily used with skis having different widths. This is because the width of the member 12' can be readily varied merely by pinching or stretching its Z-shape.

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. The glass mat 13 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 fiber glass 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 along the length of the ski. Means such as not shown spaced pins or staples 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 all have the same characteristics in the final product. For skis having somewhat different characteristics then a different program tape is selected. Thus, the invention makes it possible to repetitively produce a great variety of skis having predetermined characteristics, and this can be done at minimal labor cost and without the end product being subject to variations due to errors in human judgement. For example, if two skis run according to the same program are cut transversely at the same place, an examination of the cut sections will show that both skis have the same number of filament wound threads. Also, the invention makes it possible to uniformly control the desired build of filament along the length of the ski. This of course, is possible because the program tape can uniformly vary the speed of the rotating ski and the lengthwise traveling carriage with respect to each other independent of human judgement. 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 filament 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 fiber 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.

On one preferred embodiment illustrated in FIGS. 1-10, 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 to be described shortly. The top surface member 23 may of course, be molded separately as a channel-shaped member and then assembled to the core 17. In any event, the top surface assembly 20 as thus described is a relatively simple, strong and low-cost structure. Since there are no separate side members and the entire top surface assembly 20 may be formed in a single-molding operation, an additional savings in manufacturing costs results.

A protective metal edge 24 is also molded in place along the upper edges of the top surface assembly 20 during mold-forming of the plastic 23. The metal edge 24 is preferably a helically wound wire or coil which prevents top edge damage and has other advantageous characteristics such as a high-quality decorative effect. Conventional aluminum edges having a high-tensile strength producing a stiffer ski while the coiled spring edge 24 is extensible and yet may be made of a tough stainless steel without impairing the ski properties. As shown in FIG. 9, the edge 24 may also comprise separate left-hand and right-hand coils to provide herring bone decorative effect. In addition, the coil can extend the full length of the ski, or be only at the front portion since that part is more vulnerable to top edge damage.

The bottom surface assembly 25 comprises, in the embodiment of FIGS. 3-7, a polyethylene 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 are bonded to each other by a suitable material 26' such as a soft resilient urethane plastic. The material 26' completely covers the top of skiing strip 26 to be firmly bonded thereto. It also completely encapsulates the part 27 except for its outer running edge corner, and fills to-be-described 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. The apertures 39 may 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. It is entirely possible, however, to use a continuous L-shaped running edge 27 without the refinements of FIGS. 8 and 10.

FIG. 3 discloses the tip portion 33 of the ski 10 in cross section including the foam core 11, the epoxy-resin-filled glass filament wound portion 34 of the molded core and the outer polyurethane molded cover and sides 23 having the integral helically wound wire form 24 to prevent top edge damage and the polyethylene base or running surface 26. A bottom tip protector 36, see also FIG. 8, is welded to the running edges 27 and bonded to the running surface 26 to form a separate subassembly which can be stored and rapidly assembled to the core assembly 17 and top surface assembly 20 during manufacture.

FIG. 4 shows a view of the ski tail portion 41 including the above-described elements and having a tail guard 42 formed at the end of the ski 10. Tail guard 42 may be an integral formation on material 23. FIGS. 5, 6 and 7 illustrate, respectively, cross-sectional views of the nose section 33, waist section 44 and the tail section 41 of the ski 10. The sections 41, 33 and 44 vary both in width and in height in order to provide the ski configuration of FIGS. 1 and 2. Additionally, the waist section 44 is shown raised above the ground 46 due to the bottom camber of the ski 10. The shown configuration of the ski is obtained during the mold operations formed on the ski form 17 prior to winding and during curing of the resin on the winding.

Briefly, in practicing the invention, first the molded ski form comprising parts 11, 12, 12', 13 and 14 is formed in mold 22. Then the filament 16 is wound on the molded ski form and the resin on the filament is cured in a mold. At this time the ski form 17 is given some additional shaping to finalize its basic configuration. The bottom subassembly 25 comprising parts 26, 26', 27 and 36 will have been separately formed in readiness to be united with the ski form 17 and its top assembly 20 into a finished product. This is accomplished by positioning coil 24 in mold, then some plastic material 23, then ski form 17, then some more material 23 on top of ski form 17, and then finally bottom subassembly 25 over the additional plastic material 23 and closing the mold so as to cause the plastic material 23 to completely envelope the ski form 17 and bond itself to the ski form and the bottom subassembly 25.

The unique ski 10 which is described above and is produced by the method of the present invention represents a considerable improvement over conventional skis. The subject ski is light in weight and well dampened to minimize vibration. Furthermore, since the winding operation can be carefully controlled, it is possible to obtain the precise strength and thickness for particular conditions of use. For example, it is possible to vary the application of the winding in order to produce a ski having the desired "flex." A low polar moment of inertia also results and tends to improve the maneuverability of the ski since the weight distribution can be carefully controlled during the winding operation.

FIGS. 17-24 illustrate various embodiments of the present invention employing the core assembly 17 in unique combinations with different top-surface assemblies and bottom surface assemblies. The drawings represent typical cross section views across the waist of the ski.

For example, FIG. 17 proposes a core 17 surrounded by a shell of soft resilient polyurethane material and a polyethylene base 48 having a pair of metal running edges 49 embedded in the corner positions thereof. A metal member may also be embedded in the upper corner portions of the polyurethane shell 47 as described in the preferred embodiment. However, the particular polyurethane material may be selected to resist top edge damage without the use of protective metal edges.

In FIG. 18, the core assembly 17 is enclosed within a polyurethane envelope 51. The upper protective edges 52 and the bottom running edges 53 are embedded in the polyurethane material. The ski also includes a polyethylene running surface 54 which is bonded to the polyurethane envelope 51. A further modification may include a plastic inlay 55 along the upper surface as shown in FIG. 19.

The ski shown in FIGS. 20 and 21 comprises a core assembly 17, a top surface assembly 56 and a polyethylene base 57. The top surface assembly 56 comprises a vacuum-formed plastic shell having aluminum edges 58 with anchoring means 60 formed thereon. The base 57 includes steel running edges 59 which provide the necessary holding capacity on ice or snow. The ski of FIG. 21 also includes a plastic inlay strip 61 which may be a phenolic material bonded along the upper surface thereof.

FIG. 22 shows an embodiment of the invention wherein the ski walls 62 are formed integral with a base portion 63 to provide a simple, strong and low cost structure. The "box" thus formed provides an ideal cavity for loading and curing the wound core 17. Furthermore, the flexing of the ski is somewhat less influenced by the steel edges 64 since they are resiliently bonded together with the base 65. The shell 62 and 63 may consist of polyethylene material which is bonded to a polyethylene base 65. The base plastic material and the shell plastic material may be the same or different plastic and may be another color if desired. An upper plastic strip 76 and metal edges 77 are also bonded over the upper portion of the ski.

The ski of FIG. 23 comprises a soft resilient polyurethane cap 66 and a polyethylene base 67 bonded thereto in order to encapsulate the core assembly 17. A unique running edge 68 is molded into the base 67. The edge 68 is of smaller cross section than conventional edges and does not impart its tensile strength to resist bending of the ski. The edge 68 may also slide (with frictional restraint) lengthwise within its enclosure but it is locked in and cannot be removed laterally. It may, therefore, be readily replaced and it also dampens the vibration of the ski and insulates the shocks from the main body of the ski. A similar edge could also be used along the upper portion of the ski and in several of the other previously described ski designs.

FIG. 24 shows a ski including the core 17, upper protective edges 69, separate die-cut side strips 71, an upper plastic strip 72 and a lower base strip 73 having running edges 74 bonded thereto, all of which are bonded to the core 17.

In the above embodiments, a tip protector and a tail bumper may be included in the various moldings where it proves advantageous. Otherwise, they may be separately mounted to the ski. The overall arrangement for the front and rear portions of the various designs is primarily the same as the preferred embodiment with the necessary changes to reflect the different structures.

Another embodiment of the invention shown in FIG. 18 is depicted in FIGS. 25-29. Referring to those FIGS., a ski 75 includes a lightweight urethane foam core 11 fabricated in the general shape of a ski and reinforced by one or more fiber glass layers, such as unidirectional layers 14, as most clearly shown in FIG. 27. A binding plate 12 is embedded in the core intermediate the ends thereof and near the upper surface thereof. The reinforced core is then wound with a resin treated fiber glass filament 16 in a helical winding pattern, which may be varied as desired to impart predetermined characteristics to the ski 75.

A bottom assembly 25 which includes a pair of L-shaped running edges 27 joined adjacent the tips thereof, as at 36, are bonded to a polyethylene running surface 26 by a layer of soft resilient urethane plastic. The bottom assembly is formed by laying the metal running edges 27 over the polyethylene running surface 26. The running edges are L-shaped in cross section (FIG. 29) such that when laid over the running surface 26 a portion thereof will extend on top of the sides of the running surface. A plurality of elongated apertures 39 are formed on the top surface of the running edges. The soft urethane material is placed completely over the top of the assembled metal running edges and running surface assembly with the material filling in the elongated apertures 39 to aid in forming a secure bond between the metal and the polyethylene.

The thus formed bottom assembly is joined to the wound reinforced core by an envelope of polyurethane 23 which, when reacting with the urethane layer used in bonding the bottom assembly together, forms a firm bond therebetween. This latter process is done in a mold such that the polyurethane envelope 23 is formed to a desired contour such as to form the sides and top of a ski. Finally, a layer of plastic material 61 is placed on the top of the ski for decorative and appearance purposes. The various portions of the ski are shown in cross section in FIG. 26 and in an exploded view, FIG. 28.

What has been described above are merely illustrative examples of the application of the principles of the invention. Numerous other arrangements may be readily devised by those skilled in the art which will embody the principles of the invention and fall within the spirit and scope thereof.