1. Field of the Invention
The invention relates to snowshoes and, more particularly, to the fixed pivot axle or pivot rod for such showshoes.
2. Description of the Related Art
The snowshoe has existed for a few thousand years. Until a decade ago, showshoes use was primarily utilitarian (i.e., hunters, forestry, exploration, etc.). The original materials of wood and animal hide have been replaced with lightweight metals, plastics, and composites, and the major consumer markets have become recreational in nature.
Snowshoes add a platform to the foot sole to increase the size of the footprint. The larger the footprint, the less one is likely to sink below the surface of the snow. Snowshoes have a tendency to be cumbersome, and impair the natural human locomotion of walking. Recreational consumers demand that showshoes be comfortable to use, and allow natural body movements.
Innovations during the past fifteen years have improved the human/snowshoe interface. Most manufacturers have developed designs which allow sagittal plane rotation, or forward or rearward movement of the foot; however, they have restricted the frontal plane rotation, or transverse, side to side movement of the foot, for better control.
Most prior art showshoe designs use a fixed pivot axle to achieve sagittal plane rotation. These systems make no provision for frontal plane variations. The effect is similar to operating a vehicle without springs.
When walking on snowshoes, irregularities in the snow pack cause a step to step variation in the frontal plane surface, with frontal plane rotation being similar to “roll” in an aircraft. The human anatomy can accommodate angular variations of up to 10°.
The snowshoe suspension system of the invention allows additional “roll” from the plane of the fixed pivot rod axis, wherefore the activity is less tiring, with less impact on the body.
A second advantage of frontal plane rotation is the instance wherein one walks in a direction perpendicular to a slope, called “traverse”, since the snowshoe frame assumes the angle of the slope. The pad of the invention permits frontal plane rotation which allows the lower leg to be nearer to vertical, whereby less stress is placed on the ankle.
Snowshoes are usually fitted with a fixed, transversely-extending, pivot axle or rod upon which a snowshoe binding is pivotally mounted for limited front to rear rotation. This design is the most economical to produce and is very popular with European snowshoes.
The pad of the invention is disposed between the snowshoe binding and its fixed pivot axle or rod, which has a toe crampon depending therefrom. The pad functions as a “shock absorber” and provides for varying degrees of frontal, or side to side rotation of the snowshoe binding and crampon relative to the fixed pivot axle. The pad allows rotation angles of varying degrees in either left or right directions.
The pad hereof is preferably molded from resilient material such as rubber, or a thermoplastic olyefin (TPO) or a thermoplastic rubber (TPR), or similar elastomers.
Referring to
As best seen in
Intermediate portion 20 of the pivot rod pad 10 is separated from forward portion 18 by a first pair of axially aligned slots 24 and 26 which extend inwardly from opposite side walls, generally indicated by 28 and 30 respectively, of the pivot rod pad, with slots 24 and 26 being disposed in spaced parallelism to a forward wall 32 of forward portion 18.
Intermediate portion 20 of pivot rod pad 10 is separated from rearward portion 22 by a second pair of axially aligned slots 34 and 36 which extend inwardly from side walls 28 and 30 respectively in spaced parallelism to the first pair of slots 24 and 26 and in spaced parallelism to a rearward wall 38 of rearward portion 22.
The slots 24 and 34 which extend inwardly from sidewall 28 define a first resilient finger 40, located at one end of intermediate portion 20, while slots 26 and 36 which extend inwardly from sidewall 30 define a second resilient finger 42, located at the opposite end of intermediate portion 20.
As best seen in
The lower surface of forward portion 18 of pivot rod pad 10 lower face 46 is cut away or relieved to provide a series of spaced, aligned grooves 48, while the lower surface of rearward portion 22 is cut away or relieved to provide a pair of side-by-side recesses 50.
The lower surface of intermediate portion 20 of pivot rod pad 10 is cut away or relieved to provide a centrally located, longitudinally-extending, groove 52 and a pair of spaced, reliefs 54 and 54′, with one such relief being disposed at each end of groove 52.
The lower faces of each resilient finger 40 and 42 are identical to each other, with each finger including a downwardly curved outer end 56 and a pair of spaced, parallel ribs 58 and 60 which depend from each finger and extend inwardly from the outer end 56 of each finger.
Ribs 58 are disposed adjacent slots 24 and 26 which separate fingers 40 and 42 from pivot rod pad forward portion 18, while ribs 60 are disposed adjacent slots 34 and 36 which separate fingers 40 and 42 from pivot rod pad rearward portion 22.
Ribs 58 and 60 define a longitudinally-extending, channel 61 on the lower surface of each finger 40 and 42, with the channel 61 of each finger being axially aligned with groove 52 of intermediate portion 20.
The lower faces of outer ends 56 of fingers 40 and 42 are each provided with a cutout 62, for purposes to appear.
The several grooves, recesses, reliefs and channels in contoured lower face 46 of pivot rod pad 10 contribute to the resilience of the pad, reduce its weight and permit mating of the pad with pivot rod assembly 12, as will appear.
Pivot rod assembly 12, which is best seen in
It must be noted that the pivot rod pad 10 of the invention may be used with other than molded snowshoes.
Pivot rod pad 10 may be used with snowshoes fabricated from wood, metal, thermoplastic or composites of those materials.
Pivot rod assembly 12 includes a rod 64 which is encased in a sleeve 66 having bosses 70 and 72 at its opposite ends, with each boss being formed integrally with and extending inwardly from an adjacent side wall of opening 63 in snowshoe 14.
Sleeve 66 has a raised, longitudinally extending hub 68 located centrally of its length.
Pivot rod assembly 12 need not be formed integrally with snowshoe 14; it may be formed as a separate member, which is fixed to the snowshoe.
Rod 64 and sleeve 66 of pivot rod assembly 12 may be other than the circular cross-sectional shape as shown in the drawings and may also comprise a single unitary member.
In use, pivot rod pad 10 is positioned so as to rest on pivot rod assembly 12, with centrally-located hub 68 of sleeve 66 of the pivot rod assembly being snugly receivable in centrally-located groove 52 provided in lower face 46 of intermediate portion 20 of the pivot rod pad, while bosses 70 and 72 of sleeve 66 of the pivot rod assembly serve as stops for the outer ends 56 of fingers 40 and 42 of the pivot rod pad, as will appear.
As best seen in
Boot housing 74 is preferably fabricated as an integral unit from a sturdy thermoplastic material and includes a flat base 78 having a pair of spaced, wing-like heel members 80 extending rearwardly and upwardly from a rear edge thereof, a pair of spaced, centrally-located, finger-like instep members 82 extending upwardly from the side edges thereof, and a centrally-located toe member 84 extending forwardly and upwardly from a front edge thereof.
A system of straps 86, best seen in
Toe crampon 76 is preferably formed as an integral unit from metal and includes a substantially flat base 88 having a first trio of teeth 90 depending angularly rearwardly from its rear edge, a second trio of teeth 92 extending angularly downwardly and forwardly from its forward edge and a pair of spaced teeth 94, each of which extends downwardly from an opposite side edge of base 88 immediately forwardly of the first trio of teeth 90.
Base 88 of crampon 76 has a centrally located channel or groove 96 formed therein and extending transversely thereacross.
A transversely extending opening 98, best seen in
Groove 96 of crampon 76 is of appropriate size, location and configuration to receive pivot rod assembly 12 therein.
Opening 98 of groove 96 is of appropriate size, location and configuration to receive central hub 68 of sleeve 66 of pivot rod assembly 12 therein, whereby free forward and rearward pivotal movement of crampon 76 relative to pivot rod assembly 12 is permitted.
Boot housing 74 of snowshoe binding assembly 16 is secured to pivot rod pad 10 and to crampon 76 as by screws or bolts 100 which extend through aligned openings 102, 104 and 106 provided in base 78 of boot housing 74, in pivot rod pad 10 and in base 88 of crampon 76 respectively, the screws or bolts 100 having nuts 108 threaded thereon.
As seen in
Snowshield member 110 is preferably fabricated from a sturdy thermoplastic material and helps to preclude snow from packing into crampon 76.
As best seen in
When the snowshoe is unweighted, as in the position of
When the snowshoe is weighted, as in the position of
In such weighted condition, pivot rod pad 10 permits frontal plane, or side-to-side rotation. In
While a frontal plane angle of rotation of 3.25° is illustrated in
Number | Name | Date | Kind |
---|---|---|---|
RE25472 | Howe | Nov 1963 | E |
4161071 | Maul | Jul 1979 | A |
4720927 | Abegg | Jan 1988 | A |
5259128 | Howell | Nov 1993 | A |
5493794 | McKenzie et al. | Feb 1996 | A |
5517772 | Anderson | May 1996 | A |
5787612 | Mahoney et al. | Aug 1998 | A |
5809667 | Liautaud | Sep 1998 | A |
5809668 | Kiniry et al. | Sep 1998 | A |
5829173 | Svetlik et al. | Nov 1998 | A |
5946829 | Quellais et al. | Sep 1999 | A |
6003249 | Watson | Dec 1999 | A |
6105281 | Wing et al. | Aug 2000 | A |
6112436 | Quellais | Sep 2000 | A |
6163984 | Faber et al. | Dec 2000 | A |
6178666 | Kiniry et al. | Jan 2001 | B1 |
20030126764 | Emerson et al. | Jul 2003 | A1 |
Number | Date | Country | |
---|---|---|---|
20040187355 A1 | Sep 2004 | US |