WO1997028861A1

WO1997028861A1 - Snowshoe with a raised rear portion

Info

Publication number: WO1997028861A1
Application number: PCT/FR1997/000242
Authority: WO
Inventors: Gérard Ramboz
Original assignee: Folly's
Priority date: 1996-02-09
Filing date: 1997-02-07
Publication date: 1997-08-14
Also published as: FR2744645A1; EP0879073A1; FR2744645B1

Abstract

A snowshoe including a generally flat central portion (36) with a generally straight longitudinal cross-section forming the boot supporting portion. A rear portion (32) extending from said central portion (36) has a lower surface (37) that rises up from the point (38) where it is connected to the central portion (36). A central fin (39) projects from the underside of the rear portion (32) of the snowshoe. The profiled shape of the rear portion (32) not only has a significant steering effect due to the presence of a rear extension (32), but also makes it easier to lift the front of the snowshoe during walking, whereby the rear supporting point is closer to the user's foot when going downhill.

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to snowshoes used to walk on snow while avoiding excessive sinking below the upper surface of snow.

Snowshoes have been known for a long time, especially in the Nordic countries, and allow you to move on flat or uneven terrain, without sinking into powdery snow, and avoiding slipping. The rackets were formerly each made of a peripheral wooden frame, surrounding a perforated central sieve, with means for fixing a shoe on the upper face of the sieve.

More recently, snowshoes have been made entirely of molded plastic, or with a metal frame and sieve in intertwined strips.

In known snowshoes, the stiffening frame and the sieve define a generally flat bearing surface, with a front end more or less raised in a spatula with a wide central part carrying a shoe attachment articulated around a transverse axis preceded by a anterior lumen placed in the sieve towards the front end of the racket for the passage of the front of the shoe during its pivoting. The central part is generally flat with a generally straight longitudinal profile. Certain snowshoes, such as that described in document EP-A-0 613 704, furthermore comprise a rear part whose width narrows progressively towards the rear to end in an axial directing tail, generally coplanar with the central part of racket.

During the stride, thanks to the articulation of the shoe binding, the rear axial guide tail of the racket remains in contact with the snow when the user raises the foot and the front of the racket so that the front of the snowshoe comes out of the snow and, by moving the foot forwards, comes to rest more forward on the surface of the snow. The support of the axial directing tail contributes to maintaining the racket in the axial direction of progression, thus ensuring a directing effect.

However, known snowshoes with an axial guide tail have a double disadvantage: during a stride on flat ground, in powdery or soft snow, it can be seen that they are heavier to handle, larger in size for a given bearing surface, and more difficult to advance than snowshoes without an axial guide tail; when descending, the axial guide tail constitutes a hindrance by favoring the inclination of the racket downstream.

Document FR-A-1 247 018 describes a cup-shaped shoe with a rounded raised peripheral edge comprising a posterior region raised progressively upwards. The shoe is held in a fixed position on the skate by straps. The skate has no articulation. Due to the lack of articulation, the raised rear part does not have the function of an axial directing tail. Its only effect is to increase the lift on soft or brittle snow.

STATEMENT OF THE INVENTION

The problem proposed by the present invention is to design a new snowshoe structure allowing both to achieve a good steering effect, while promoting the forward progression of the snowshoe in powdery or soft snow, and while avoiding the tendency to tilt downstream of the racket progressing downhill. To achieve these and other objects, a snowshoe according to the invention comprises a central part with stiffening frame and wide carrying screen, and comprises a rear part whose width narrows progressively towards the rear, with a fixing shoe articulated around a transverse axis, and with an anterior lumen disposed in the sieve in front of said transverse axis towards the front end of the racket for the passage of the front of the shoe during its pivoting around said transverse axis; the wide central part of the racket, constituting the support under the shoe, is generally flat with a generally straight longitudinal profile, according to the invention, the rear part of the racket has a longitudinal profile with a lower surface raised progressively upwards from its connection to the central part of the racket.

Preferably, the rear part of the racket has a longitudinal profile with a lower surface which is regularly curved upwards from its connection to the central part of the racket. In this case, said longitudinal profile of the lower surface may for example be substantially circular, tangentially connecting to the lower surface of the central part of the racket.

According to a preferred embodiment, the rear part of the racket comprises at least one lower vertical longitudinal fin projecting to sink into the snow when using the racket. This fin provides a good steering effect, without increasing the length of the racket, unlike the guide tails of known rackets which substantially extend the rackets backwards.

SUMMARY DESCRIPTION OF THE DRAWINGS Other objects, characteristics and advantages of the present invention will emerge from the following description of particular embodiments, made in relation to the attached figures, among which:

- Figure 1 is a top view of a snowshoe body according to an embodiment of the present invention;

FIG. 2 is a top view of the complete snowshoe according to the embodiment of FIG. 1, with attachment for a shoe, - FIG. 3 is a bottom view of the snowshoe body of FIG. 1,

- Figure 4 is a side view in longitudinal section along the longitudinal axis I-I of Figure 2;

FIG. 5 illustrates the series of cross sections of the racket body of FIG. 1 according to the successive cutting planes A, B, C, D, E,

F, G, H, I, J, K, L, M, N, 0 in Figure 1, and

- Figure 6 is a schematic side view of the racket with the front part raised during the stride.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiment illustrated in the figures, and more particularly visible in Figures 3 to 5, a snowshoe according to the invention comprises a stiffening frame with two beams 1 and 2 connected by crosspieces anterior 3 and posterior 4. The stiffening frame surrounds a carrier screen 5. The frame is narrow, the two side members 1 and 2 substantially laterally bordering the middle racket area occupied by the shoe in use. The longitudinal members 1 and 2 are preferably substantially parallel to each other and to the axis longitudinal II of the racket, or advantageously slightly divergent towards the front. The side members 1 and 2 are preferably spaced from each other by a distance of between 10 and 15 centimeters, corresponding to the usual width of the most common shoes, for an adult racket.

In the advantageous embodiment shown in section in FIG. 5, the side members 1 and 2 are each formed of a beam of generally rectangular section oriented with its great length generally perpendicular to the general plane of the racket. With reference to FIGS. 2 and 4, it can be seen that the racket comprises a shoe binding 6, consisting for example of a plate 7 articulated around a transverse axis 8, with means 9 for securing the front of the shoe, and with means 10 for securing the rear of the shoe An anterior lumen 11, formed in the sieve 5 in front of said transverse axis 8, allows passage of the front of the shoe during its pivoting around said axis transverse 8

The rear end 12 of the plate 7 can be selectively left free, in use, to allow free pivoting of the plate 7 about the transverse axis 8, or can be selectively locked by a locking wedge 112 shown in the figures 2 and 4 The locking wedge 112 can simultaneously be shaped to serve selectively as a climbing wedge, coming to be housed under the rear end 12 of the plate 7. Referring again to FIGS. 3 and 5, it can be seen that in the main lift zone located in the vicinity front and rear αe the transverse axis of articulation 8, the chassis is bordered laterally on either side by two lateral fins 13 and 14 The lateral fins 13 and 14 each have a transverse profile raised in spider's leg, better visible in section in FIG. B, with, starting from the respective adjacent spar 1 or 2, a first portion respectively 15 or 16 inclined upward t up to a top connection edge 17 or 18 respectively. The top connection edge 17 or 18 connects the first portion 15 or 16 to a second portion respectively 19 or 20 itself inclined downwards to the lateral edge external 21 or 22 of the racket. The first portion 15 or 16 is advantageously longer than the second portion 19 or 20. The external lateral edge 21 or 22 is raised relative to the general plane of the screen 5.

It is understood that the top connecting edges 17 and 18 constitute effective means of stiffening the fins 13 and 14 which, moreover, consist of a relatively thin plate. To increase the stiffening in the appropriate zones, transverse ribs are provided such as the ribs 23 and 24 connecting the adjacent lower faces of the first 15, 16 and second 19, 20 inclined portions of lateral fin 13 and 14. As can be seen better in FIG. 5 in section, the longitudinal members 1 and 2 are projecting below the general bearing plane formed by the screen 5 and the lateral fins 13 and 14. Preferably, the longitudinal members 1 and 2 are connected to the screen 5 and to the lateral fins 13 and 14 at their upper end of beam with generally rectangular section. The particular structure of a racket body with a narrow projecting frame bordered by generally raised lateral fins 13 and 14 has advantages in itself, independently of the presence of a raised rear part. This structure makes it possible in particular to improve the support on hard snow, and to reduce the angle of inclination of the racket during a progression through, while maintaining a satisfactory support surface on powder snow.

Referring to Figures 1 to 3, we see that the side fins 13 and 14 have, from the transverse axis 8 in the direction of the front to the front of the racket, an edge 21 or 22 profiled area rear respectively 25 or 26 generally parallel or slightly deviated with respect to the longitudinal axis II of the racket and connecting angularly to a front zone respectively 27 or 28 concave approaching the longitudinal axis II of the racket.

In the advantageous embodiment shown, the concave front region 27 or 28 has, with the longitudinal axis II of the racket, an average angle of approximately 30 degrees. This front zone 27 or 28, angularly connected to the rear zone 25 or 26, constitutes a penetrating preferential zone, favoring the penetration of the corresponding upstream fin 13 or 14 in the snow on the side and towards the front as illustrated by the arrow 136 in FIG. 1, for example during a crossing crossing. We can thus significantly reduce the angle of the racket, and increase walking comfort and grip of the racket.

In the embodiment illustrated in FIG. 3, the longitudinal members 1 and 2 comprise, in the support zone located under the boot, preferably from a position slightly in front of the transverse axis 8 to a median position the along the racket, toothed knives 29 and 30 projecting under the lower edge of the side members 1 and 2. By the combination of the knives 29 and 30 and the side members 1 and 2 close to the axis II of the racket, a particularly rigid and stable support area for supporting the racket on hard snow or ice.

As shown more particularly in FIGS. 4 and 5, the wide central part 36 of the racket, constituting the support under the shoe, is generally flat with a generally straight longitudinal profile. The rear part 32 of the racket has a longitudinal profile with a lower surface 37 progressively raised upwards from its connection 38 to the central part 36 of the racket. In the embodiment shown in FIG. 4, the rear part 32 of the racket has a longitudinal profile with a lower surface 37 regularly curved upwards from the connection 38 to the central part 36 of the racket, for example a lower surface with a substantially circular longitudinal profile, tangentially connecting to the lower surface of the central part 36 of the racket. For example, good results are obtained with a rear part with a circular profile of length between 15 and 20 centimeters approximately and whose lifting height at the posterior end is between 3 and 5 centimeters approximately.

In the embodiment illustrated in FIGS. 4 and 5, the rear part 32 of the racket comprises a lower vertical longitudinal fin 39, protruding to sink into the snow when the front of the racket is raised. The fin 39 improves the steering effect of the rear part 32 of the racket, by constituting a relatively fine edge, and makes it possible to shorten the racket substantially while retaining a good steering effect. In the case of a raised form of the rear part 32 of the racket, the fin 39 is preferably located away from the ground surface when the foot is supported on the racket, which avoids the possible deterioration of the fin and allows to use a fin relatively thin with improved steering effect. At the same time, the risks of catching the fin are reduced to roughness on the ground such as branches. As can be seen in FIG. 4, the fin 39 may advantageously have a lower edge with a longitudinal profile in an arc of a circle, with an anterior portion raised forward to reduce the risks of snagging. A circular arc profile with a radius between 15 and 25 centimeters gives good results.

It will be noted that a steering fin such as the fin 39 can be advantageously provided under a rear part of a flat racket or only very slightly raised. The fin then produces a satisfactory steering effect, regardless of the presence of an upward lift.

As best seen in FIG. 5, according to the embodiment illustrated in the figures, in the central part 36 of the racket, the stiffening frame comprises the two longitudinal members 1 and 2 projecting below the general bearing plane formed by the sieve 5 In the rear part 32 of the racket, the side members 1 and 2 extend gradually towards each other to meet at the rear end of the racket. The fin 39 is formed by a longitudinal lower rib, which protrudes from the underside of the screen 5 in the rear part 32 of the racket, and the height of which increases progressively from front to rear to exceed below the side members 1 and 2 near the rear end of the racket

The upper face 40 of the rear end of the racket advantageously has a convex transverse profile, preventing the accumulation of snow on the rear end of the racket, accumulation which would cause the end to sink into the powdery or soft snow.

As can be seen in FIG. 4, the front end 31 of the racket is advantageously curved longitudinally upwards. The upward bending of the front end 31 favors the exit of the front of the racket from the snow during the stride.

FIG. 6 illustrates the essential advantage of the invention, by comparing the effect obtained with a racket with a curved rear end according to the invention, and the effect obtained with a racket with a straight rear end. In solid line, there is shown a racket according to the invention with rear end 32 raised in support on the ground during the stride, at moment when the user raises the foot by a determined height Hl. In dashed lines, a traditional racket with a rear end 41 is shown on the right, resting on the ground also shown in dotted lines, at the instant when the user lifts the front of the racket by the same height Hl.

We see that, by the effect of the bending of the rear end, two advantages are obtained:

- According to the first advantage, for the same height Hl of lifting the racket at the transverse axis 8, the front 31 of the racket according to the invention is raised by a height H2 which is greater than the height H3 according to which the front 31 of a racket with a rear end 41 is lifted right; thus, the increase in height H2-H3 favors the exit of the front 31 of the racket above the snow during the stride, to authorize and facilitate the advance of the racket to the next step, for a given lifting effort Hl of the user;

- According to the second advantage, when using the racket downhill, the raised shape of the rear part 32 of the racket reduces the effort of tilting the racket downstream when the rear part 32 is supported on the ground. It is thus found that a racket according to the invention has improved maneuverability qualities, while retaining good directivity by the effect of the fin 39. Simultaneously, the rear portion 32 raised promotes the retreat of the racket, avoiding to crash in the snow. Thanks to the curved shape of the rear part 32 of the racket, the rear support is brought closer to the foot of the user during downhill uses.

In the embodiment illustrated in the figures, the screen 5 is generally a perforated flat surface. In the main lift zone of the racket located under the foot, behind the transverse axis 8, the screen 5 comprises two flexible lateral wings 33 and 34, secured according to their lateral edge external to the corresponding spar 1 or 2, and separated one from the other by a space 35, to give them elastic flexibility. By their elastic flexibility, the wings 33 and 34 promote the detachment of snow which naturally tends to accumulate under the sieve 5. The present invention is not limited to the embodiments which have been explicitly described, but it includes the various variants and generalizations thereof contained in the field of claims below.

Claims

1 - Snowshoe, comprising a wide central part (36) with stiffening frame (1, 2, 3, 4) and wide carrier screen (5), and comprising a rear part (32) whose width narrows progressively towards the rear, with a shoe binding (6) articulated around a transverse axis (8), and with a front lumen (11) disposed in the screen (5) in front of said transverse axis (8) towards the end racket front (31) for the passage of the front of the shoe during its pivoting around said transverse axis (8), the central part (36) of racket, constituting the support under the shoe, being generally flat with longitudinal profile generally straight, characterized in that the rear part (32) of the racket has a longitudinal profile with lower surface (37) progressively raised upwards from its connection (38) to the central part (36) of the racket.

2 - Snowshoe according to claim i, characterized in that the rear part (32) of snowshoe has a longitudinal profile with lower surface (37) regularly curved upwards from its connection (38) to the central part ( 36) racket. 3 - Snowshoe according to claim 2, characterized in that said longitudinal profile of the lower surface (37) is substantially circular, tangentially connecting to the lower surface of the central part of the racket (36)

4 - Snowshoe according to any one of claims 1 to 3, characterized in that the rear part (32) of the racket comprises at least one lower vertical longitudinal fin (39) projecting to sink into the snow during the use of the racket and to ensure a good steering effect.

5 - Snowshoe according to any one of claims 1 to 4, characterized in that:

- in the central part (36) of the racket, the stiffening frame comprises two longitudinal members (1, 2) projecting below the general bearing plane formed by the screen (5),

- in the rear part (32) of the racket, the side members (1, 2) extend gradually towards each other to meet at the rear end of the racket, U

- a longitudinal lower rib (39) forming a lower vertical longitudinal fin protrudes from the underside of the screen (5) in the rear part of the racket, and its height increases progressively from front to rear to protrude below the side members ( 1, 2) in the vicinity of the rear end of the racket.

6 - Snowshoe according to any one of claims 1 to 5, characterized in that the upper face (40) of the rear end of the racket has a convex transverse profile.

7 - Snowshoe according to any one of claims l to 6, characterized in that the front end (31) of the racket is curved longitudinally upwards.

8 - Snowshoe according to any one of claims 1 to 7, characterized in that:

the chassis is narrow, the two longitudinal members (1, 2) substantially laterally bordering the middle racket area occupied by the shoe in use,

- in the main lift zone situated in the vicinity of the transverse articulation axis (8) in front and behind, the chassis is bordered laterally on either side by two lateral fins (13, 14), - the longitudinal members (1, 2) protrude below the general bearing plane formed by the screen (5) and the side fins (13, 14).

9 - Snowshoe according to claim 8, characterized in that the lateral fins (13, 14) have a transverse profile raised in spider leg, with, starting from the adjacent spar (1, 2), a first portion ( 15, 16) inclined upwards to a top connecting edge (17, 18) to a second portion (19, 20) inclined downwards to the corresponding external lateral edge (21, 22) of racket.