FR2726744A1 - Magnetic attachment of shoe to ski or bicycle pedal - Google Patents

Abstract

The shoe (2) is attached to the ski or bicycle pedal (20) by two separated magnets (11,12) fixed to the ski or pedal and a magnetic closing plate (30) fixed to the shoe. The ski or pedal magnet is flanked by two magnetic armature plates (13-15,14-16), these two plates being drawn to the closing plate to close the magnetic field.The axis of the ski or pedal magnet extends parallel to that of the closing plate and to the longitudinal axis of the ski which is parallel to the shoe longitudinal axis. The closing plate is composed of two half plates ahead of the ski magnet and plate armatures. The plate armatures pass through the body of the pedal or ski and their edges are cylindrical and prominent relative to the body

Description

DEVICE FOR ATTACHING A SHOE TO A
APPARATUS COMPRISING A MAGNET.

 The present invention relates to a device for attaching a shoe to an appliance comprising a magnet.

 More specifically, it relates to a device of the safety type, that is to say designed so that the separation of the shoe and the device is automatic in the event of a fall; the device is, for example, a ski or a bicycle pedal.

We have already proposed in PATENT ABSTRACTS OF
JAPAN Vol. 16, no 034 (M-1204), a magnet fastening device for fixing a shoe on a bicycle pedal unfortunately, as this device is arranged, it does not allow, in the congestion authorized in the law of cooperating areas the shoe and the device, in this case a bicycle pedal, to obtain a fastening, or fastening, force of sufficient magnetic nature taking into account the stresses to which the binding is subjected during pedaling; moreover, nothing is described in this document for the separation of the shoe and the pedal; it is indeed necessary in this type of device to provide means of distance available to the user to "take off", that is to say move the shoe off the pedal against the significant force of attraction magnetic.

 In the French patent application 93 05561 is described a device for fixing a shoe to a pedal comprising a magnet; If means of separation are provided there, for this device, which would be suitable for a high magnetic attraction force, this is limited by the design of this device.

 In international application PCT / FR 94/00376, a device of the type described in the French patent application above is arranged so that an improvement is obtained in terms of the value of the magnetic fixing force; however, it is relatively complicated to perform.

 The object of the present invention is to propose a device of the above type which is simple, light, easy to produce, compact, without the above drawbacks.

 Thus, according to the invention, a device for fixing a shoe to an apparatus comprising, on the one hand, at least one magnet means secured to the apparatus and a magnetic metal closure plate secured to the shoe, and, on the other hand, means of separation carried by the shoe and means of separation carried by the device, making it possible to cause the distance of the shoe relative to the device in the direction of an increase magnetic gap from the position which corresponds to the attachment of the shoe and the device, is characterized by the fact that the poles of the magnet means are each flanked by a magnetic metal armature plate, the two armature plates cooperating with the closure plate for closing the magnetic field.

 Preferably, the magnetization axis of the magnet means extends parallel to the closure plate.

 Advantageously, the magnetization axis of the magnet means is parallel to the longitudinal axis of the device which is itself parallel to the longitudinal axis of the shoe when the latter is fixed to the device.

 Preferably, there are provided two magnet means arranged at a distance from each other; the closure plate is made up of two half-plates, each one in line with a magnet means and its associated reinforcement plates.

 Advantageously, the removal means are arranged in a zone which surrounds the two magnet means and their associated reinforcement plates.

 According to one embodiment, the removal means carried by the device are in the form of a spherical half-cap and placed along the longitudinal axis of the device, while the removal means carried by the shoe are housings blinds of semi-conical shape.

 According to a variant, the distance means carried by the device are in the form of prominences with a trapezoidal section extending in the form of arcs belonging to the same circle, while the distance means carried by the shoe are housings blinds of complementary shape; the cross section of the removal means is such that free abutment surfaces are provided.

 According to another variant, the distance means carried by the device are in the form of cam spans arranged along an axis making an angle with the longitudinal axis while the distance means carried by the shoe consist of edges cam followers of the closure plate protruding from the sole of the shoe.

 According to another variant, the distance means carried by the device consist of ramps arranged laterally.

 Preferably, the device is provided at the rear with an access rim.

 Advantageously, the device comprises a means for adjusting the magnetic fastening force.

 In a preferred form of application, the fastening device is provided between a bicycle pedal and a cyclist's shoe.

 According to another form of application, the fixing device is provided between a ski and a ski boot.

 The description which follows relates to the application of the device according to the invention to the fixing of a cyclist's shoe on a bicycle pedal, to facilitate understanding; the application of the invention to another device, such as a ski for example, will not be described, this transposition presenting no particular difficulty.

 To better understand the object of the invention, we will now describe, by way of purely illustrative and nonlimiting example, embodiments shown in the accompanying drawings.

On these drawings
- Figure 1 is a general schematic view showing a shoe and a pedal equipped with a fastening device according to the invention
- Figure 2 is a partial section of Figure 1 on a larger scale, the shoe and the pedal being spaced from each other to facilitate reading of the drawing
- Figure 3 is a view, partially in section, along
Figure III-III
- Figure 4 is a view, partially in section, along
IV-IV of figure 2
- Figure 5 is a sectional view of a variant of the shoe of Figure 2
- Figure 6 is a view similar to Figure 4 and corresponds to another variant of the device according to the invention
- Figure 7 is a partial sectional view along VII-VII of Figure 6
- Figure 8 is a pedal seen from above corresponding to another variant of the device according to the invention
- Figure 9 is a view along Ix-Ix of Figure 8
- Figure 10 is a pedal seen from above corresponding to another variant of the device according to the invention;
- Figure 11 is a view along XI-XI of Figure 10
- Figure 12 is a view along XII-XII of Figure 6
- Figure 13 is a schematic sectional view of a variant of the pedal of Figure 2 equipped with an adjustment means
- Figure 14 is a partial view, in partial section, similar to Figure 1 showing a variant device according to the invention
- Figure 15 is a top view of yet another pedal variant
- Figure 16 is a section along XVI-XVI of Figure 15.

 FIGS. 1 to 4 show a first variant of the fastening device according to the invention for securing a cyclist's shoe 2 to a pedal 20.

 The sole 3 of the shoe 2 carries, by overmolding, a metallic plate of magnetic metal 30, called a closing plate, here of generally rectangular shape.

 The pedal 20 consists of a pedal body 21 rotated by a pedal pin 22; the pedal body 21 is made of non-magnetic material such as a metal or light metal alloy, or of plastic material; the pedal body 21 supports two magnets 11, 12 arranged on either side of the pedal pin 22; the magnets 11, 12 are oriented so that their magnetization axis extends parallel to the closure plate 30 when the shoe 2 is placed on the pedal 20 in its operational position; in the example shown, the magnetization axis of the magnets 11, 12 and the pedal axis 22 are orthogonal; the poles of each of the magnets 11, 12 are flanked by reinforcement plates, respectively 13-15 and 14-16, made of magnetic metal; the armature plates 13, 15, 14, 16 cover at least completely the poles of the magnets with which they are associated and are flush with their upper edge the upper surface of the pedal body 21 to which they are perpendicular; maintaining the magnets and their armature plates is obtained by overmolding the pedal body 21; alternatively, the magnets and their armature plates are placed in blind housings provided in the pedal body 21 and held by gluing or by molding an adhesive resin the closure plate 30 of the shoe 2 has dimensions such that, when the shoe 2 and the pedal 20 are in operational engagement with each other, the closure plate 30 covers at least the magnets 11, 12 and the upper edges of the associated reinforcement plates 13, 15, 14, 16; in the operational position, the closure plate 30 is in contact with the upper edges of the armature plates 13, 15, 14, 16 but the magnets 11, 12 are at a distance from the closure plate 30.

 The arrangement which has just been described has the advantage of bringing into play very strong magnetic attraction forces between the shoe and the pedal, and this by using magnets 11, 12 of reduced volume; by way of example, using two magnets 11, 12 in the form of parallelepipedic pellets of 31 × 11 × 5 millimeters of metal alloy based on Iron-Neodymium-Boron, the force of magnetic attraction, therefore of securing the shoe 2 to the pedal 20, is at least 60 kg, which is more than enough.This is due to the fact that the lines of the magnetic field developed by each of the magnets close through magnetic metallic materials when the shoe 5 rests on the pedal 20: in fact, these lines from the magnet 11 for example pass successively through one of the armature plates, the armature plate 13 for example, the closure plate 30, and the other armature plate, the armature plate 15, to join the magnet there; the lines of the magnetic field corresponding to the magnet 12 close similarly; it will be understood that the field lines can be closed in a similar manner if the closing plate 30 is replaced, in one piece, by two half-plates 31, 32, as shown in FIG. 5, provided that each half plate 31, 32 covers the upper edges of the reinforcement plates. Such an arrangement with two rectangular half-plates 31, 32, the length of which extends along the width of the shoe, also has the advantage of making it easier for the cyclist to walk on the ground while minimizing the flexibility of sole 3 of shoe 2.

 The shoe 2 and the pedal 20 have means of separation with ramps 41, 51 and 42, 52.

 The means 41, 42 for moving the pedal away are each produced in the form of a spherical half-shell projecting relative to the upper face, for securing, to the pedal body 21, which securing face is brought to cooperate with shoe 2; according to the example shown, the means 41, 42 for moving the pedal 20 away are produced, in a simple manner, from rods embedded in the pedal body 21.

 The removal means 51, 52 of the shoe 2 are produced in the form of blind housings of semi-conical shape provided in the sole 3; they have a shape complementary to that of the means 41, 42 for removing the pedal and are intended to receive these means 41, 42 for removing the pedal 20; when the shoe 2 is in place on the pedal 20, the closure plate 30 is in contact with the upper face, of attachment, of the pedal body 21 while the prominent moving away means 41, 42 of the pedal 20 are not not in contact with the inner surface of the blind away means 51, 52 of the shoe 2; a clearance therefore exists circumferentially and vertically between the distance means 41, 42, on the one hand, and 51, 52, on the other hand: this clearance, in all these directions, facilitates a slight movement of the foot relative to the pedal during the pedaling operation and allows morphological adaptation without excessive stress; it is indeed known that the attachment between the shoe 2 and the pedal 20, of a magnetic nature, is maximum in the direction perpendicular to the closure plate 30 but weak in the direction of the sliding of said closure plate 30 on the pedal 20; when the circumferential clearance mentioned above is caught during pedaling, the shoe 2 is in tangential abutment on the pedal 20 and the force is transmitted without problem from the foot to the pedal 20, thanks to the vertical sides delimiting the half portions -spherical and semi-conical shell which constitute the means of removal; it will be understood that any other form can be given to the removal means as soon as they comprise ramp-shaped means, complementary, and possibly, as described above, the means of frank stop; indeed, of course, these abutment means could be provided independent of the removal means.

 As can be seen in FIGS. 2 to 4, the means 41, 42 for removing the pedal and 51, 52 for the shoe are placed, relative to the axis 22 of the pedal, beyond the magnets 11, 12 and their reinforcing plates 13-15, 14-16 associated, along the longitudinal axis of the pedal 20 perpendicular to the axis 22 of the pedal; therefore, the removal means 41, 42 are as far as possible from each other, just as of course as the removal means 51, 52 associated with this arrangement, it is easy to "take off" despite the significant vertical magnetic attachment force; in fact, to "take off", the cyclist rotates the foot in one direction or the other, for example the heel of the shoe outwards; in this movement, the sole 2 rotates on itself in the connection plane; the circumferential clearances between the means for removing the boot and the pedal are caught; firstly, one of the pairs of distance means 41, 51 or 42, 52 acts as a pivot for shoe 2 while the other couple 42, 52 or 41, 51 by virtue of a ramp effect allows to take off the sole of the pedal with a tolerable torsional force of the foot thanks to the large lever arm represented by the distance between the pairs of distance means 41, 51 and 42, 52; in a second step, the closure plate 30 no longer being pressed against the pedal 20 and the magnetic attraction force thus decreasing, the two pairs of separation means 41, 51 and 42, 52 provide a ramp effect and the separation between the shoe 2 and the pedal 20 is carried out without difficulty.

 According to the example shown, the means 51, 52 for moving the shoe 2 away are provided in the closure plate 30 which extends longitudinally enough to do this; a progressive entry guide 53 is also provided at the front part of the closure plate 30 to facilitate the positioning of the shoe on the pedal, this entry guide 53 with inclined walls allowing the shoe to be guided by means of the cooperation, with the guide 53, of the means 41 for removing the pedal before in the approach or gripping phase.

 As a variant, as shown in FIG. 5, the means of separation 51, 52 of the shoe, as well as the guide 53, are provided in the sole 3, the closure plate 30 being limited to the right of the magnets 11, 12 and their plates reinforcements 13, 15, 14, 16 associated.

 The device according to the invention also has the advantage of making it possible to economically produce a reversible pedal, that is to say which can be grasped by the shoe on any of its two faces; in fact, it suffices, with respect to the variant of FIGS. 2 to 4, to have the reinforcement plates 13, 15, 14, 16 flush not only with the upper face of the pedal 20 but also with the lower face of the latter.

 Figures 6 and 7 show a variant of removal means; according to this variant, the sole 3 of the shoe 2 carries distance means 71, 72 produced in the form of blind housings of trapezoidal section extending in the form of arcs belonging to the same circle; the means 61, 62 for removing the pedal are shown in phantom and are prominent on the pedal, having a general shape complementary to that of the means 71, 72, respectively, for the shoe, a vertical clearance 61 and circumferential 67 existing between the associated removal means when the shoe and the pedal are secured, for the same reasons as those described above, the operation of the device according to this variant being identical to that of the variant of FIGS. 2 to 4 described above ;; as visible in FIG. 12, the cross section of the distance means is such that vertical abutment spans are provided, with respect to FIG. 12, like the vertical spans 73, 74 of the shoe, so that, by cooperation of these ranges with those, parallel and corresponding, of the pedal, the longitudinal force, both before and behind, is transmitted without problem from the foot to the pedal during pedaling.

 Referring to Figures 8 and 9, we see another variant of the device according to which the remote means 17, 18 carried by the pedal are arranged diagonally relative to the pedal 20, which further increases their distance; they are produced in the form of cylindrical bearing surfaces of cams, the height of which, relative to the plane of attachment of the pedal 20, increases as one moves towards the outside of the pedal; the shoe, not shown in these figures, carries two half-closing plates shown in phantom 33, 34 in Figure 8; these two closing half-plates 33, 34 do not flush with the outer surface of the sole of the shoe, as in the variants described hitherto, but protrude from the sole under the shoe; each of the half-plates 33, 34 extends in line with the magnets 11, 12 and their associated reinforcement plates 13-15, 14-16 and even beyond towards the removal means 17, 18 of the pedal so that it has an edge 35, 36 cam follower intended to cooperate with the cam bearing surfaces of the pedal removal means 17, 18: it is these edges 35, 36 cam followers which constitute the shoe removal means; a lateral stop 19 is provided and cooperates with the edge of the material, referenced 54 in the figure, of the sole of the shoe which fills the gap between the two half-plates 33, 34 of reinforcement; this stop 19 makes it possible to avoid lateral movement of the foot under stress.

 Figures 10 and 11 show a pedal 20 whose body 21 is provided at the rear with an access flange 39 extending over the width of the pedal 20 and above the plane of attachment of the pedal; such an access rim 39 facilitates the positioning of the shoe on the pedal; in fact, the shoe being approached from the right to the pedal relative to FIG. 10, such an access flange 39 prevents the shoe closing plate from being magnetically pressed in this approach phase on the magnetic means constituted by the magnet 12 and its armature plates 14, 16, which would hinder the continuation of the movement of the shoe relative to the pedal; indeed, the access flange 39 gives rise to the existence of an air gap between the shoe and the pedal, more precisely between the closure plate and said magnetic means, as long as the shoe-pedal assembly is not in place, which minimizes the magnetic attraction effort and makes it easier to put the shoe on the pedal.

 FIG. 13 shows that the device according to the invention is such that it is possible to provide it, in a simple manner, with a means 60 for adjusting the magnetic fastening force, thus making available to the user a means of adapting the joining force, from the shoe to the pedal, according to its needs. The adjustment means 60 consists of a slide 63 mounted to slide in a transverse housing 49 inside the body of the pedal 20 disposed under the magnets 11, 12 and the lower edges of their associated reinforcement plates 13-15, 1s16; the sliding, in one direction or the other, of the slider 63 in the housing 49 is obtained by turning an adjusting screw 66, in one direction or the other, said screw being coupled to the slider 63 and cooperating with a tapping corresponding provided in the pedal body; the slide 63 is made of non-magnetic material and carries two branch plates 37, 38 made of magnetic material; these branch plates 37, 38 are secured to the slide by gluing, overmolding, riveting or by any other means; they are arranged in relation to each other and have dimensions such that they are capable, in the most left position, in relation to FIG. 13, of the slide 63 in its housing 49, of completely covering the magnets 11, 12 and the lower edges of their associated reinforcement plates 13-15, 14-16.

 As will be easily understood, depending on the position of the slide 63, a certain number of lines of force, corresponding to the magnetic field developed by the magnets 11, 12, are closed by the branch plates 37, 38 instead of closing by the plate, or half-plates, for closing the shoe; thus, by subtracting some of them, it is possible to limit, or by addition, to increase, the number of lines of force participating in the magnetic effort of securing the shoe to the pedal, and therefore to adjust this one.

 The arrangement according to which the magnets 11, 12 and their associated plates 13-15, 1s16 are not in line with the axis of the pedal makes it possible to place the latter as close as possible to the joining surface, which, as we know, is very favorable in terms of pedaling force. Figure 14 shows that it is even possible to have the pedal axis cut by the securing plane; the cylindrical sheath 43 of the pedal axis extends partly above said plane and is received with transverse play in a cylindrical housing 44 provided in the shoe sole; it can be noted that during the rotation of the foot with a view to "taking off" a ramp effect is obtained by cooperation of the outer surface of the sleeve 43 with the inner surface of the cylindrical housing 44, ramp effect which comes to reinforce that obtained by the removal means not shown in FIG. 14.

 Figures 15 and 16 show a variant of the distance means carried by the pedal 20; these means consist of ramps 26, 28, 46, 48 arranged laterally along approximately the two diagonals, respectively 26, 48 and 28, 46; the fastening device according to these figures operates in a similar manner to that of Figures 8 and 9, but has the advantage over the latter that the separation of the shoe and the pedal can be obtained regardless of the direction of rotation relative applied to the shoe. Note, moreover, that the pedal according to these figures 15 and 16 has at the rear an access ramp 25 and at the front a front stop 29 intended to cooperate with a counter-stop carried by the shoe not shown; lateral guides 27, 47 promote the correct positioning of the shoe relative to the pedal during its approach movement; these lateral guides 27, 47 are also in the form of ramps; they can, therefore, also participate in moving the shoe away from the pedal during loosening.

Claims (13)

 1. Device for attaching a shoe (2) to an appliance (20) comprising, on the one hand, at least one magnet means (11, 12) integral with the appliance (20) and a closure plate (30, 31-32, 3334) made of magnetic metal secured to the shoe (2), and, on the other hand, means of separation (51, 52; 71, 72; 35, 36) carried by the shoe ( 2) and removal means (41, 42; 61, 62 ;; 17, 18 26, 28, 46, 48) carried by the device (20), making it possible to cause the shoe (2) to move away relative to the device (20) in the direction of an increase in the magnetic air gap from the position which corresponds to the attachment of the shoe (2) and the device (20), characterized by the fact that the poles of the magnet means (11, 12) are each flanked by an armature plate (13-15, 14-16) made of magnetic metal, the two armature plates (13-15, 14-16) cooperating with the closing plate (30, 31-32, 33-34) for closing the magnetic field.  2. Device according to claim 1, characterized in that the magnetization axis of the magnet means (11, 12) extends parallel to the closure plate (30, 31-32, 33-34).  3. Device according to one of claims 1 or 2, characterized in that the axis of magnetization of the magnet means (11, 12) is parallel to the longitudinal axis of the device (20) which is itself parallel to the longitudinal axis of the shoe (2) when the latter is fixed to the device (20).  4. Device according to one of claims 1 to 3, characterized in that there are provided two magnet means (11, 12) arranged at a distance from each other.  5. Device according to claim 4, characterized in that the closure plate (31-32, 33-34) is composed of two half-plates, each being in line with a magnet means (11, 12) and its associated reinforcement plates (13-15, 14-16).  6. Device according to one of claims 4 or 5, characterized in that the separation means are arranged in an area which surrounds the two magnet means (11, 12) and their armature plates (13-15, 14-16) associated.  7. Device according to one of claims 1 to 6, characterized in that the separation means (41, 42) carried by the device (20) are in the form of a spherical half-cap and placed along the axis longitudinal of the device, while the removal means (51, 52) carried by the shoe (2) are blind housings of semi-conical shape.  8. Device according to one of claims 1 to 6, characterized in that the separation means (61, 62) carried by the device (20) are in the form of prominences with trapezoidal section extending in the form of arches belonging to the same circle, while the distance means (71, 72) carried by the shoe (2) are blind housings of complementary shape, the cross section of the distance means (61, 71; 62, 72) being such that abutment surfaces are provided.  9. Device according to one of claims 1 to 6, characterized in that the separation means (17, 18) carried by the device (20) are in the form of cam spans arranged along an axis making an angle with the longitudinal axis while the distance means (35, 36) carried by the shoe consist of edges, cam followers, of the closure plate (33-34) which protrudes from the sole (3) of the shoe (2).  10. Device according to one of claims 1 to 6, characterized in that the separation means (26, 28, 46, 48) carried by the device (20) consist of ramps arranged laterally.  11. Device according to one of claims 1 to 10, characterized in that the device comprises an adjustment means (60) of the magnetic fastening force.  12. Device according to one of claims 1 to 11, characterized in that the fixing device is provided between a bicycle pedal and a cyclist's shoe.  13. Device according to one of claims 1 to 11, characterized in that the binding device is provided between a ski and a ski boot.