FR2811903A1 - Vibration damping device for a ski or snow board. - Google Patents

Abstract

This ski vibration damping device (13) has a central zone (14) and two branches (15,16), which run parallel to the upper surface (6) of the board on each end of the central zone (14). An underside (22) of the device lies on the upper surface (6) of the board (1) so that each branch (15,16) has a zone connected to the central zone (14). The central zone (14) is connected to the upper surface (6) of the board by a rigid connector. The natural form of the under surface (22) of the device is concave with open depressions (33,35) in the zone of the free ends (26.28) of each branch (15,16). The open depressions (33,35) are filled with a tablet of a viscose flexible material. Due to the fact that the central zone (14) of the device is fixed to the upper surface (6) of the board (1), the free ends (26,28) are connected flexibly to the upper surface of the board (1) because of the original concavity of the device

Description

Board fitted with a vibration damping device The invention

  relates to a device intended to dampen the vibrations of a snowboard and concerns

  a gliding board provided with said device.

  Such boards are used for skiing,

snowboarding, or whatever.

  In the case of skiing, it is known to associate a device with

  the board to modify its behavior.

  For example, document EP 510 308 discloses a ski provided with a beam and a device intended to absorb vibrations. According to this document, the device comprises an elongated element connected to the ski by a rigid connection means and which comprises a free end spaced longitudinally from the

rigid connection means.

  The device also includes a resistance means connected to the ski which cooperates with the free end to oppose

to his displacement.

  The object of the invention is in particular to simplify the structure, and the production, of a board provided with a

  device for damping vibrations.

  To do this, the invention provides a device intended to dampen vibrations of a snow gliding board, the device comprising a central zone and at least two branches which extend substantially parallel to the upper face of the board. and other in the area

  central, a lower face of the device being located above

  above the upper face of the board, each branch having a free end area connected to the central area by an intermediate area, the central area being secured to the upper face of the board by a rigid connection means. The device is characterized in that the natural shape of the underside of the device is concave, that at least one open cavity is provided in the free end zone of each branch on the side of the underside, that the open cavity is partially filled at least with a viscoelastic material, and by the fact that the central zone of the device is designed to be secured to the upper face of the board so that the free end zone of each branch is elastically biased against the upper face of the board taking into account the initial concavity of the device. Thus, the concavity of the device naturally brings the free end zones into contact with the upper face of the board, which avoids the use of a resistance means connected to the board. Therefore the structure and the realization of the

  board, fitted with the device, are simplified.

  Other characteristics and advantages of the invention

  will be better understood using the description which follows,

  with reference to the appended drawing illustrating, by non-limiting examples, how the invention can be implemented, and in which: - Figure 1 is a perspective view of a board provided with a device intended to modify the stiffness and / or to dampen vibrations, according to an exemplary embodiment, - Figure 2 is an enlarged view of the device of Figure 1, - Figure 3 is a section on III-III of Figure 2, - Figure 4 is a section according to IV-IV of Figure 2, - Figure 5 is a vertical longitudinal section of the device before its installation on the board, - Figure 6 is a bottom view of the device, - Figure 7 is a vertical longitudinal section of the device implanted on the board, - Figure 8 is a schematic bottom view of a device, according to a second embodiment, - Figure 9 is a schematic bottom view of a

  device, according to a third embodiment.

  The first example is described below using the figures

1 to 7.

  As is known in FIG. 1, a board, represented in the form of a ski 1, is delimited in a longitudinal direction BL by a first end 2 and by a second end 3. The ski 1 is further delimited by a first lateral edge 4, by a second lateral edge 5, by an upper face 6, and by a lower face or

sole 7.

  From the first 2 to the second 3 end, the ski 1 successively has a first raised end portion 8, a first contact line W1, a first intermediate portion 9, a central portion 10, a second intermediate portion 11, a second contact line W2, and

  a second raised end portion 12.

  The contact lines W1, W2 are oriented substantially in a transverse direction of the ski 1, and the central portion 10 is provided to receive retaining elements

of a shoe.

  A device 13, secured to the upper face 6 of the ski 1, for example in the second intermediate portion 11, is provided for modifying the natural behavior of the ski. It is

  made of a flexible material such as plastic.

  This material can be polyamide, polyurethane, or the like. According to the embodiment illustrated in FIG. 2, the device 13 comprises a central zone 14, from which extend a first branch 15 and a second

  branch 16 on either side of the central zone 10.

  Preferably, the branches 15, 16 are oriented according to the

BL longitudinal direction of the ski.

  A first end 17 and a second end 18

  delimit the device 13 lengthwise.

  The device 13 is further delimited by a first lateral edge 19, by a second lateral edge 20, by a face

  upper 21 and by a lower face 22.

  As can be seen in FIG. 3, the branch 15 has a continuous section of fairly large thickness and of

  reduced width near the first end 17, that is

  ie on the side of the central portion 10 of the ski 1.

  This part of the device 13 has good resistance

  in bending, along a transverse axis of the device.

  As seen in Figure 4, the branch 16 has a discontinuous section of fairly large thickness and fairly large width near the second end, that is to say on the side of the second contact line W2. The branch 16 has a lyre shape with two lateral portions 23, 24 separated by a cavity 25, the portions 23, 24 are

  joining at the second end 18.

  This part of the device 13 has good flexural strength along a transverse axis of the device, and in

  torsion along a longitudinal axis of the device.

  In Figure 5 the device 13 is shown in section in its natural state, that is to say before it is secured

skiing 1.

  The first branch 15 has a first free end area 26 connected to the central area 14 by a first intermediate area 27. By analogy the second branch 16 has a second free end area 28 connected to the central area 14 by a second zoned

intermediate 29.

  According to the invention, all of the zones 14, 26, 27, 28, 29

  forms a single piece or body 30.

  The underside 22 of the device 13, which extends from the first 17 to the second 18 end, is naturally concave. Thus when the device 13 is placed on a flat surface without being constrained, the lower face 22 being opposite the surface, only the ends 17, 18

touch the surface.

  In FIG. 5, the longitudinal direction DL symbolizes

this surface.

  Each of the first 15 and second 16 branches, considered as such, is itself concave on the side of the face

lower 22.

  Provision may be made to stiffen the body 30 by adding

  reinforcements in its thickness or on one of its faces.

  For example, a first end reinforcement 31 is fixed, by any suitable means such as bonding, at the first end 17 of the device 13. A second central reinforcement 32 is fixed at the central zone 14. Each of the reinforcements 31, 32 is located at the upper face 21

of the device 13.

  The material of the reinforcements is chosen to obtain the desired flexural strength. It may be a metal, a metal alloy, a plastic, or the like. The flexural strength is also conditioned by the thickness of the body 30. This thickness increases from the first end 17 to the central zone 14, to

  then decrease to the second end 18.

  The first free end zone 26 has an open cavity 33, the opening of which is formed in the lower face 22. The cavity 33 is filled by a wafer made of viscoelastic material 34. By analogy the second free end zone 28 has an open cavity 35, the opening of which is formed in the lower face 22. The cavity is also filled by a plate of material

viscoelastic 36.

  The cavities 33, 35 are each shown in the form of a parallelepiped, form given by way of example. The central zone 14 has studs 37 projecting from the underside 22. These studs are reliefs which are part

  integral with the body 30 of the device 13.

  As best shown in Figure 6, the studs 37 are edges which extend in the transverse direction of the

device 13.

  A preferred technique for joining the device 13 to the ski 1 is that of vibration welding, as seen.

better in figure 7.

  In the direction of its thickness, the ski 1 successively comprises a sliding layer 38, a lower reinforcement 39, a core 40, an upper reinforcement 41, and a covering layer 42, the latter delimiting the upper face 6

ski.

  The material constituting the cover layer 42 of the ski 1 is substantially the same as the material constituting the body 30 of the device 13. It may be a plastic containing polyamide. A single operation is sufficient to weld the device 13 to the ski 1. Before welding the central zone 14 of the device 13 is above the upper face 6 of the ski 1, taking into account

  the naturally concave shape of the underside 22.

  After welding, the concavity of the lower face 22 is reduced, the central zone 14 of the device 13 is secured to the upper face 6, and the end zones 26, 28 of the device are elastically biased against the upper face 6 of the ski 1 The pads of viscoelastic material 34 and 36 are applied against the upper surface of the ski to which they adhere naturally. The walls of the cavities keep them enclosed and protect them from any crushing or creep out

of their accommodation.

  Other techniques could be used to

  assemble the central zone 14 to the ski, for example screws.

  When the ski 1 flexes or twists as is the case during driving, there is a slight relative sliding of the end zones 26, 28 of the branches 15, 16 relative to the upper face 6 of the ski 1. This sliding takes place substantially in the longitudinal direction DL of the device 13. The viscoelastic plates 34, 36 contained in the cavities 33, 35 of the branches 15, 16 are stretched in shear, therefore they absorb the vibrations of the ski

in flexion or torsion.

  The other exemplary embodiments of the invention are

  shown schematically using Figures 8, 9.

  Only the differences from the first example are

described.

  The second example is visible in FIG. 8. A device 50 according to the invention has the general shape of a Y. Three branches 51, 52, 53 extend on either side of a central attachment zone 54. Each end zone 55, 56, 57 of a branch has a cavity 58, 59, 60 filled with a viscoelastic material. A branch 51 is oriented in the longitudinal direction DL of the device 50, while the other branches 52, 53 form an angle with respect to this direction. The side of the device 50 which contains a single branch absorbs well the flexural deformations of the ski, while the side of the device 50 which contains two branches absorbs well the torsional deformations of the ski, due to the orientation

branches 52, 53.

  As in the previous case, the device 50 is initially concave, that is to say that before being assembled to the ski, the central zone 50 is raised relative to

  the alignment of the ends of the branches 51 and 52 or 51 and 53.

  The third example is visible in Figure 9. A device 70 according to the invention has the general shape of an X. Four branches 71, 72, 73, 74 extend on either side of a central zone d 'hooking 75. Each end zone 76, 77, 78, 79 of a branch has a cavity 80, 81, 82, 83, filled with a viscoelastic material. Each of the branches forms an angle with respect to the longitudinal direction DL of the device 70. Thus the two sides of the device absorb

  well the torsional deformations of the ski.

  The device 70 is initially concave so that the assembly of the central zone 75 with the ski applies against the upper surface of the ski the ends of the branches 71, 72,

  73, 74 and their viscoelastic plates.

  Of course, the invention is not limited to the examples described above, and contains all the technical equivalents

  which may fall within the scope of the claims which

  to follow. Other forms can be provided for producing the device according to the invention. The same board can be fitted with one or more devices. For example, a ski may have a device in the first intermediate portion, and a device in the second intermediate portion. A snowboard could have a device in each

  portions between the contact lines.

  The shape of a device located in a portion of a board may be different from the shape of a device located

  in another portion of the same board.

Claims (8)

  1- Damping device (13, 50, 70) of the vibrations of a snow gliding board, the device (13, 50, 70) comprising a central zone (14, 54, 75) and at least two branches ( 15, 16, 51, 52, 53, 71, 72, 73, 74) which extend substantially parallel to the upper face (6) of the board (1) on either side of the central zone (14, 54,), a lower face (22) of the device (13, 50, 70) being situated above the upper face (6) of the board (1), each branch having a free end zone (26, 28, 56, 57, 76, 77, 78, 79) connected to the central zone (14, 54,) by an intermediate zone (27, 29), the central zone being secured to the upper face (6) of the board (1) by a rigid connection means, characterized in that the natural shape of the underside (22) of the device (13, 50, 70) is concave, that at least one open cavity (33, 35, 58, 59,, 80, 81, 82, 83) is provided in the end zone libr e (26, 28, 55, 56, 57, 76, 77, 78, 79) of each branch on the side of the underside (22), that the open cavity (33, 35, 58, 59, 60, 80, 81, 82, 83) is filled at least in part by a plate of viscoelastic material, and by the fact that the central zone (14, 54, 75) of the device (13, 50, 70) is designed to be secured to the upper face (6) of the board (1) so that the free end zone (26, 28, 55, 56, 57, 76, 77, 78, 79) of each branch is elastically biased against the upper face (6 ) of the board (1)   taking into account the initial concavity of the device.   2- Device (13, 50, 70) according to claim 1, characterized in that the free end zones (26, 28, 55, 56, 57, 76, 77, 78, 79) of the branches (15, 16, 51, 52, 53, 71, 72, 73, 74), the intermediate zones (27, 29) of the branches (15, 16, 51, 52, 53, 71, 72, 73, 74), and the zone central (14, 54, 75) of the device (13, 50, 70) form a monobloc piece.   3- Device (13, 50, 70)) according to claim 1 or 2, characterized in that the central zone (14, 54, 75) of the device (13, 50, 70) comprises studs (37) provided for be secured to the upper face (6) of the board (1) by   the technique of vibration welding.   4- Device (13) according to one of claims 1 to 3,   characterized in that the device (13) comprises two branches (15, 16) oriented in the same longitudinal direction (DL) of the device (13) on either side of the central area (14).   - Damping device (13) according to claim 4, characterized in that one (16) of the branches has a form of lyre.   6- damping device (13) according to claim, characterized in that a first reinforcement (31) is fixed at the first end (17) of the device, and that a second reinforcement (32) is fixed in the central area (14) of the device.   7- Damping device (50) according to one of   Claims 1 to 3, characterized in that it comprises three branches (51, 52, 53).   8- Damping device (70) according to one of   Claims 1 to 3, characterized in that it comprises four branches (71, 72, 73, 74).   9- Snow gliding board (1), characterized in that it is provided with a device (13, 50, 70) according to one   of claims 1 to 8, the central zone (14, 54, 75) of the   device (13, 50, 70) being assembled integrally to the face upper (6) of the board (1).   - Board (1) according to claim 9, characterized in that the device (13, 50, 70) is located in a   intermediate portion (9, 11) of the board.