EP1709999A1

EP1709999A1 - Magnetic connection system

Info

Publication number: EP1709999A1
Application number: EP05252157A
Authority: EP
Inventors: Ezio Panzeri
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-04-06
Filing date: 2005-04-06
Publication date: 2006-10-11

Abstract

A binding system for a snowboard uses magnetic connecting portions to connect the board to the rider. The connecting portions are formed as a ball and socket from a polymer embedded with magnetic material. This allows the rider to twist his foot with respect of the plane of the board and also out of the plane of the board.

Description

The present invention relates to a connection system for connecting a board to a boot. The connection system is a magnetic binding system primarily for use with sports boards such as snowboards, but conceivably could be used in conjunction with wake boards, kite boards or any similar board which requires a binding to secure the foot of a user to the board. The connection system may also have other applications where a quick release connection is required such as for rowing, water-skiing, cycling, skiing, mountain boarding, etc.
Various mechanical bindings for snowboards are known. Typically these comprise a cage of straps that is secured to the snowboard that the user straps his foot into. The user's foot is effectively bound to the snowboard. Other systems are known in which a mechanical quick release fitting is provided on the bottom of the user's boot and this connects with a corresponding fitting secured to the board. Such connection systems are also referred to as "bindings". Many of these binding systems are complex and fiddly to fit, which can be a hindrance to the user, especially when the user is wearing gloves or has cold or wet hands. Snow and ice can also build up in the bindings making it difficult to connect the board to the boot. Additionally, the known bindings have a fixed angular position with respect to the board, requiring them to be set up before hand using a screwdriver or allen key. It is also a preconception that these bindings should hold the rider's foot in a fixed position and not allow the boot to rotate in the plane of the board or perpendicular to the board.
US 2003/0047910A1 discloses the use of a magnet as a centering device to ensure that the boot is in the correct position. A mechanical locking mechanism is then used to secure the boot to the snowboard. This device has the advantage that it automatically locates the boots on the bindings. However, it can still be fiddly to lock the boots into place with the mechanical system, and the problem of restricted movement is not addressed.
The design of snowboard bindings can contribute to injuries sustained by snowboarders. The incidence and causes of snowboarding injuries are discussed in "Snowboarding Injuries" by Craig C. Young, M.D., and Mark W. Niedfeldt, M.D. of the Medical College of Wisconsin, published in American Family Physician, Vol. 59/No. 1, January 1, 1999. Knee injuries and ankle injuries were found to account for around 16% and 17% of snowboarding injuries respectively. Therefore, if a binding could place less strain on the knees and ankles, then the risk of injury could be reduced.
Many snowboarding injuries take place when the rider falls. Beginners often fall regularly, and therefore a high percentage of injuries occur during the riders first experience of snowboarding or in their first season of snowboarding. More advanced riders may fall when attempting jumps or other aerial manoeuvres. One mechanism of ankle injury is a forcing of the ankle into dorsiflexion and inversion, which may occur during a landing from an aerial manoeuvre or a jump, especially when the landing has been over-rotated.
Snowboarding injuries also take place while the person is waiting in ski-lift lines or entering and exiting ski lifts. Snowboarders push themselves forward with a free foot while in the ski-lift line, leaving the other foot (usually that of the lead leg) locked on the board at a 45 to 90 degree angle, placing a large torque force on this leg and predisposing the person to knee injury if a fall occurs.
Thus it would be desirable to provide a new binding system that would reduce the incidence of injury to the riders knees and ankles.
Viewed from a first aspect, the present invention provides a connection system for coupling a board to a boot comprising a male and a female member, one of which is provided on the board and the other is provided on the boot, the members being attracted to each other by means of magnetic force, wherein the male and female members comprise complimentary curved engagement surfaces.
The male and female members ("connecting portions") preferably take the form of a "ball and socket" connection, the male member providing the "ball" and the female member providing the "socket".
The "ball" is preferably only a small portion of a sphere, for example, a slice of the external surface of a sphere, i.e. a dome representing less than one quarter of the volume of the sphere, more preferably less than one sixth, and yet more preferably less than one eighth of a volume of the sphere. The "ball" is therefore preferably a shallow curved dome shaped protrusion having a height which is perhaps a third, or more preferably a quarter, of the diameter generating the curved surface. This stud-like protrusion is preferably provided on the board.
The "socket" is a complimentary shape and takes the form of a shallow recess that can accommodate, or substantially accommodate, the curved dome shaped protrusion of the male member.
The curved engagement surfaces may alternatively take the form of a disc and cylindrical recess, possibly with a stepped, chamfered or curved profile where the circumferential surface meets the radially extending end surface. In another embodiment the male member is a shallow cone or truncated cone. In another, the male member has a more complex shape with rotational symmetry to allow rotational movement of the boot with respect to the plane of the board.
The use of a "ball" and "socket" allow the feet to be rotated with respect to the board. It is thought this can reduce the risk of injury, in particular knee or ankle injury caused by restricted foot movement. Additionally by allowing more freedom of movement the board can be easier to use, and there is greater flexibility in the positions that can be taken up during use. When only one foot is on the board, for example when queuing for a ski lift or using a drag lift, the foot can be rotated into a comfortable position. By reducing the forces on the ankles and knees in this way, risk of injury can be avoided. The process of connecting the board to the boot is also much simpler than the known strap bindings.
On certain sections of a slope, for example, the rider may prefer to have his foot more in line with the direction of travel, e.g. for speed, or more perpendicular e.g. for turning. It may also relieve some of the strain on the ankle whilst on a chair lift if the front foot can be twisted into a different position with respect to the board. The rider can also decide to change from "regular" to "goofy" (i.e. left or right foot leading) whilst on the piste by simply swapping the feet over. This may also give rise to new styles of riding a board and allow the more expert user to perform more complex manoeuvres. It is also easier for the novice rider to connect his boots to the board, particularly when in deep snow. If a standard size of ball and socket is used, then there is also no need to adjust the bindings for different sized boots.
There are no interlocks or mechanical devices as used in the prior art, and therefore the magnetic binding is simple and straightforward to use, even if the user is hampered by gloves or cold/wet hands or the snowboard is covered in snow.
Another advantage of this invention is the reduced number of parts compared with the traditional binding, making it simple and economical to manufacture. There are no buckles or straps to snap or mechanical connections to become bent or broken, thereby minimising any inconvenience to the user on the piste.
If desired for certain applications, the magnetic binding system could still be used in conjunction with straps or other conventional binding features for additional security. However, preferably the magnetic binding system is used alone to connect the board to the boot. Additional to this, a safety leash may be present to connect the rider to the board.
In the most preferred embodiment the "ball" is a section of a sphere, and the "socket" is a cavity of corresponding shape. This allows the boot to rotate both in the plane of the board (and also out of the plane of the board if the size of the socket allows). This shape, having a smooth curved surface, also minimises entrapment of snow and ice in the binding which could otherwise hinder the connection.
The "ball" may have a mounting portion, for example, a mounting plate which can be attached to the board, and the "socket" may be formed in the sole of the boot or incorporate a mounting plate for securing it to the sole of a boot.
The "ball" and/or the "socket" may be made of a magnetic polymer material. Preferably the material is a ferro plastic, comprising a mixture of atomized or powdered ferrous material and at least one polymer such as nylon or Teflon.
Preferably both the "ball" and "socket" comprise magnetic means in the form of a permanent magnet to provide a strong magnetic attraction for example, hard ferrite. However it is possible that one of the "ball" and "socket" could be made of a material in which magnetism can be induced by the magnetic properties of the other component, for example, soft ferrite, or through a different magnetic source coupled to the soft magnets. The material is powdered and embedded in a matrix of polymer material.
In a preferred embodiment, the male connecting portion and/or the female connecting portion includes a magnetic source which can be moved in order to vary the strength of the magnetic force attracting the two connecting portions. For example, the male connecting portion can have a permanent magnet acting as the magnetic source which is moveable within a ferro plastic "ball". There may be two magnetic sources, one to provide the main magnetic force, and one to provide a variable magnetic force.
A mechanism to vary the magnetic force allows the connection system to be adjusted to suit different rider weights, or different uses. A light weight or inexperienced snowboarder could use a lower magnetic force than a heavier or a more experienced snowboarder.
The magnetic force between the two halves of the connection system should be strong enough that the two components do not come apart during normal riding or under the weight of the board when covered in snow. However it should allow the parts to separate when, for example, the rider catches an edge and falls in order to prevent injury to the ankles or knees. It should also be of a strength that allows the rider to disconnect the board easily when he wants to, for example, when he arrives at the bottom of a piste. If the magnetic force is variable, then the connection system may include means for reducing the magnetic force manually to disconnect the board.
In a preferred embodiment, a moveable magnetic source is used which is arranged to reduce the magnetic force when the rider falls. The magnetic source may be arranged to move to reduce the magnetic force when the force on the board passes a set threshold and/or when the orientation of the board changes. This may be achieved by mechanical means, such as springs and dampers, or electrical means such as an accelerometer coupled to an actuator.
Magnetic polymer materials are advantageous as they can be easily and cheaply formed into complex shapes, and can be corrosion resistant and low friction. A preferred material is Teflon mixed with atomized ferromagnetic material. This is known as "ferro plastic" or "ferplastic", and can be injection molded into the shapes required. It is also known to make ferro plastic materials using nylon instead of Teflon, for example the materials which are available from Magneti Permanenti Industriali SrI in Italy. Other similar cheap polymers, such as epoxy and polyester resins, could also be used. This avoids the use of traditional ferrite block and metal parts, which are heavy and costly to cut and shape, especially when the shape is curved as in the present invention. It may also be possible to use a matrix of a hard rubber material or even a ceramic. The ferromagnetic material may be a conventional hard ferrite (ceramic) or particles/members of Fe, Ni and Co alloys. Other magnetic materials that could be used include the Alnico series of materials, NdFeB and SmCo materials. The magnetic material is preferably present as powder within the matrix material for ease of injection moulding. However, the magnetic material could be present as members, e.g. bar or circular magnets that are encased in the matrix material to form the desired shape.
The whole connection system may be manufactured using injection moulding. If desired, the different parts of the connection system can be manufactured using different materials or manufacturing methods. For example, the "ball" and any mounting portion could be made separately so that the mounting portion can be made from a strong material to transfer forces between the "ball" and the board without risk of damage, for example, it could be made of a metal such as aluminium, titanium or steel, and the ball can be made from a low friction material, with good magnetic properties, such as the ferro plastics discussed above.
The connection system may have other uses than on a snowboard, for example, anywhere where a binding is used to fix the rider's foot to a piece of equipment. Examples of such equipment include a wake board or kite board. With this type of equipment, the "boot" may be smaller and may take the form of a shoe having a modified sole.
From a second and third aspect, the present invention provides a snowboard having a "ball" (the male connecting portion), more preferably two; and a boot comprising a "socket" (the female connecting portion) for use in the connection system described above. The positions of the "ball" and "socket" on the board and boot respectively, may be reversed as desired. In such an arrangement the "ball" may need to be recessed in the sole of the boot to facilitate walking.
From a fourth aspect the present invention provides a method of manufacturing a magnetic connection system as described above, the method comprising moulding a male member and a female member, the two members being of corresponding shape and being formed of a magnetic material which is embedded in a polymer material, the male and female members being formed by injection moulding.
From a fifth aspect, the present invention can be seen to provide a snowboard binding for connecting the boot of a rider to a snowboard, the binding being configured to allow the rider to rotate his boot about an axis extending through the binding and substantially perpendicular to the plane of the board whilst the boot is connected to the snowboard, the boot being movable with respect to the snowboard through an angle of grater than 45°, more preferably greater than 90°.
Preferably, the method includes the step of inducing a magnetic field in the magnetic material or aligning the magnetic poles in the magnetic material in order to generate a strong magnetic force between the members.
Preferred embodiments of the present invention will now be described in greater detail by way of example only and with reference to the accompanying drawings in which:

Fig. 1 shows a perspective view of an embodiment of the present invention, where two male members of the connection system (the "balls") are mounted on a board.
Fig. 2 is a top plan view of the board of figure 1.
Fig. 3 is a side view of the board of figure 1 showing the domed shape of the "ball".
Fig. 4 is a similar view to figure 3 showing the operation of the connection system with boots attached to the board.
Fig. 5 shows a perspective view of an embodiment of a boot, showing the "socket" in the sole of the boot.
Fig. 6 shows a similar view to figure 2, indicating the range of movement of the boot on the board.
Fig. 7 shows an embodiment of the invention with adjustable magnetic force.

Figure 1 shows a board 1 fitted with magnetic bindings 2. The board 1 shown is of a shape typically used for snowboarding, although it will be appreciated that the bindings 2 are also suitable for use on boards for gliding over water or sand etc. The bindings 2 are attached to the board by conventional means, such as screws. The bindings 2 are made up of an upper engaging part, the ball 3, and a lower mounting part 4, for example, a plate, which joins the ball 3 to the board 1. These may be formed integrally or separately.
Figures 2 and 3 show the board 1 of figure 1 in plan and side view. Figure 4 shows the connection system or interface schematically with boots 5 mounted on the bindings 2. The ball 3 has a circular base, and in side view forms an arc of a circle. The boot 5, shown in more detail in figure 5, has in its sole a recess forming a socket 6 that fits onto the ball 3. The circular base is required in order to allow the boot 5 to rotate mounted on the binding 2, as shown in figure 6. As a section of a sphere is used for the ball 3, the boot can rotate in any direction. The boot 5 can rotate whilst freely in the plane of the board 1, but rotation out of the plane (i.e. about axes parallel to the plane) is restricted by the boot 5 coming in contact with the board 1. By providing greater clearance around the binding, the freedom of movement out of the plane of the board can be increased.
Figure 7 shows the a schematical view of a connection system with an adjustable magnetic force. A moveable magnetic source 7 is placed within the ball 3, and the ball 3 is made from a soft magnetic material. This enables the strength of the magnetic force to be varied by movement of the magnetic source 7. In this embodiment the magnetic source 7 is mounted on a spring.
The socket 6 needs to fit onto the ball 3 securely so that a reasonable force can be applied without the boot 5 becoming detached, thus a large contact area is preferred. However, this should be balanced against the inconvenience for the user that would be caused by a large and cumbersome socket 6 in the boot 5, which would result from an increase in the diameter and depth of the ball 3.
The bindings 2 and boot recesses are molded in a polymer magnetic material. These materials have low friction and are resistant to corrosion. Snow also tends not to stick to these materials. Low friction is required to allow free rotation of the boots 5 on the bindings 2. Corrosion resistance is useful, as the bindings and boots could be used in may severe environments and could be subjected to constant moisture, extremes of temperature, or salt water for example. A preferred polymer magnetic material is Teflon or nylon mixed with atomized ferromagnetic material. This is known as "ferro plastic" or "ferplastic", and can be injection molded into the shapes required. Ferro plastics are advantageous as they can be easily and cheaply formed into complex shapes.
In some embodiments the mounting portion 4 of the binding 2 is made of a different material, such as an alternative plastic or a metal. This material could be selected for resistance to damage at points of high stress, such as where the screws fix the binding 2 to the board 1.
Other variations are of course possible. For example, the embodiment described in detail above uses a convex ball 3 on the board 1 and a concave socket 6 on the boot 5. The ball 3 and socket 6 could be swapped so that the ball 3 is on the boot 5 and the socket 6 is on the board 1. In this case the ball 3 could be in a recess on the sole of the boot 5 so that walking is not impeded.
The male and female parts of the connection system may connect by means of direct contact of the moulded magnetic polymer material or other magnetic material. In this case, the magnetic material forms the exterior shape of the member and hence forms the engaging surface. Alternatively, the male member and/or the female member may include a housing, or a protective cover, with the magnetic material within the housing or cover. In this case, the housing or cover forms the exterior shape of the member and hence forms the engaging surface, and therefore the housing or cover is the part of the member which contacts the other member.
Whilst this detailed description has referred to a connection system made up of a "ball" and a "socket", the invention is not limited to a dome-shaped male member and correspondingly shaped female member. Any suitable shape having rotational symmetry could be used for the male member to allow the rider to rotate his foot with respect the plane of the board.
Where rotation with respect to the board is not desired, the connection system could include other shapes, such as polygonal shapes including squares and rectangles, star shapes, icons or trade marks etc. Indeed, any shape could be used as long as the male and female connecting portions are of corresponding shape. Thus, from another aspect the present invention can be seen to provide a connection system for coupling a board to a boot comprising a male connecting portion and a female connecting portion, wherein the connecting portions are attracted to each other by means of magnetic force, and further wherein the connecting portions comprise ferro magnetic material, preferably powdered magnetic material encased within a matrix of polymer material, to provide engagement surfaces of corresponding shape.
It is also envisaged that this binding system could have use in other sports where the user's feet need to be fixed to the piece of equipment. In some instances, rotational movement of the foot with respect to the equipment is not generally required apart from to release the foot from the binding, for example, by twisting the foot. This might be the case for cycling and possibly the rowing, where a simple to use quick release connection system is required. The male and female connecting portions can be profiled to provide a strong connection by having a close contact of the magnetic engagement surfaces, and camming surfaces can be incorporated which urge against each other as the connecting portions are twisted with respect to each other to thereby separate the magnetic engagement surfaces and break the magnetic attraction between the two halves of the binding. The male surface could be part of an ovaloid shape or a more complex shape. It is also envisaged that the bindings could be fitted with electromagnetic means rather than permanent magnetic means, possibly powered by a small battery pack and/or solar power, allowing the magnetic bindings to be switched on and off to make separation of boot from the board easier. In this case, the electromagnet could also be switched off when a fall is detected, or example by an accelerometer, in order to release the board and reduce the risk of injury to the rider.

Claims

A connection system for connecting a board (1) to a boot (5) comprising
a male connecting portion (3), and
a female connecting portion (6),
wherein the connecting portions are attracted to each other by means of magnetic force, and further wherein the male and female connecting portions comprise complimentary curved engagement surfaces.
A connection system as claimed in claim 1 wherein the complimentary curved engagement surfaces have rotational symmetry about an axis.
A connection system as claimed in claim 1 or 2, wherein the male connecting portion (3) is a section of a sphere, and the female connecting portion (6) is a cavity of corresponding shape.
A connection system as claimed in claim 1 or 2, wherein the male connecting portion is a cylinder and the female connecting portion is a cylindrical recess.
A connection system as claimed in claim 1 or 2, wherein the male connecting portion is conical, preferably frusto-conical, and the female connecting portion is a conical recess, preferably a frusto-conical recess.
A connection system as claimed in any preceding claim, wherein the male connecting portion is on a mounting portion (4) which can be attached to the board, and the female connecting portion (6) is formed in the sole of the boot (5).
A connecting system as claimed in any preceding claim, wherein the male connecting portion (3) and/or the female connecting portion (6) is made of a magnetic polymer material.
A connection system as claimed in claim 7, wherein the magnetic polymer material comprises a mixture of powdered ferromagnetic material in a matrix of at least one polymer such as nylon or Teflon.
A connection system as claimed in any preceding claim wherein the connecting portions are manufactured using injection moulding.
A connection system as claimed in any preceding claim for use on a snowboard.
A connection system as claimed in any preceding claim wherein the male connecting portion and/or the female connecting portion comprises a magnetic source that can be moved to vary the strength of the magnetic force attracting the connecting portions to each other.
A snowboard comprising a male connecting portion (3), preferably two male connecting portions (3), for use in the connection system of any preceding claim.
A boot comprising a female connecting portion (6) for use in the connection system of any of claims 1 to 12.