The present invention relates to a binding and parts thereof for attaching rowing shoes to a boat, which allows an easy detachment of a shoe from a foot stretcher and consequently increases the rower's safety and practicality of use. When rowing, the rower sits on a seat that moves in the longitudinal direction of the boat and rests with his feet on the foot stretcher, i. e. a foot plate that is fixed to the bottom of the boat. The rower's shoes must be secured to the foot stretcher in such a way that the rower's shoes or feet do not slip off the foot stretcher during rowing, so they must offer sufficient support when the rower pushes off, while, at the same time, in the event of the boat turning over, it must be allowed for the shoe to get detached from the foot stretcher as quickly as possible, so the rower can swim out of an overturned boat. The design of the binding allows the binding to suddenly disengage, which means that the shoe can get detached from the foot stretcher immediately, if a force greater than the force pre-set by a spring is exerted upon the binding, thus allowing the shoe to be easily detached from the foot stretcher and preventing the rowers from getting injured. Namely, during rowing, the water can grab an oar, wherein the rower's joints can be subjected to great forces that injur the rower, if the shoe is not immediately detached from the foot stretcher, i. e. the binding does not suddenly disengage.

The design of the binding according to the invention allows also an individual adjustment of the binding according to the rower's rowing method; the position of the binding and thus the position of the shoe on the foot stretcher can be adjusted for each shoe separately.

This allows an optimized adjustment of the binding and consequently of the position of the shoes on the foot stretcher for each individual rower. This is particularly desirable for athletes, as this ensures the optimal transfer of force of each individual. In addition, the design of the binding allows the shoe to rotate around the substantially horizontal axis of the binding when the latter is in the engaged position, thereby allowing the shoe to move or rotate even when the entire sole is formed rigidly without a flex zone, which is otherwise required for fastening the shoe to the foot stretcher. The use of a rigid sole is desirable, since the rigid sole provides an adequate support and even distribution of the support over the entire surface of the sole, thus reducing the loss of the output power used by the rower when pushing off and flexing the sole. The selection of the material, the sole of the shoe is made of, allows for an individual adjustment of the shoe's properties, particularly its rigidity and torsional stability.

The binding according to the invention is also suitable for use on rowing simulators and stationary bicycles.

In the classic version, especially in competitive rowing, the shoes are usually fixed to the foot stretcher in the boat, for example by screws. Depending on the rower's rowing method, the foot stretcher is adjustable in the direction of travel; its distance from the front stop that the rower's seat reaches during rowing is adjusted. In addition, the slope and height of the foot stretcher are adjustable. The rower gets to the boat barefoot or in other shoes and inserts his feet into previously fixed shoes. The upper part of both shoes is provided with velcro-type straps, with which the rower attaches the shoe to his foot. During rowing, the shoe is fixed to the foot stretcher. The sole of the shoe is centrally provided with a flex zone which allows the shoe to bend, which is necessary for the rower to reach the maximum length of the stroke and use his power for rowing. To pull the foot out of the shoe, a safety string is attached, which is connected to the velcro-type straps, wherein, when the safety string is pulled, all the velcro-type straps are released and the rower pulls his foot out of the shoe.

Fixing the shoe to the foot stretcher can also be configured by having a shoe provided in the sole or tarsal segment by a projection to be secured to the binding which is fixed to the foot stretcher. When inserted into the binding, the shoe is prevented from rotating around the binding (the binding by Shimano http://www.shimano.com/en/manufacturing/rowing.html). In order for the rower to be able to row, the sole of the shoe must be centrally provided with a flex zone. A safety string is foreseen to detach the shoe from the foot stretcher, wherein the binding disengages when the safety string is pulled, thus the rower can detach the shoe sole from the binding on the foot stretcher.

Also known in the prior art is a binding, in which the shoe is fastened to the binding via a pivotal stirrup which is rotationally fastened to a special frame on the foot stretcher. The stirrup houses a binding, into which an attachment is inserted, which is firmly formed on the sole in the toe or tarsal segment of the shoe. The rotation is not made possible by a connection between the binding and the attachment on the sole but by a rotational connection between the strap and the special frame. The disadvantage of this solution lies particularly in the fact that due to the axis of rotation, which is different from that of the conventional version, the resistance at the beginning of a stroke is less stable, especially in terms of torsion and bending, and the binding thus does not provide a sufficiently firm support at push-off (https://shoprowing.shimano.com/collections/shimano-virtual- pivot-foot- stretchers).

The binding for the rowing shoes according to the invention is adapted for a detachable connection of the shoe to the foot stretcher, wherein in an engaged connection (when the connection is engaged) the shoe is fastened to the foot stretcher, while in a disengaged connection (when the connection is disengaged), the shoe is separated from the foot stretcher, the binding consisting of a shoe part, a clamping part and optionally a limiter of the angle of rotation of the binding with respect to the plane of the foot stretcher. The shoe part is fixed to the upper part of the sole of the shoe or is integrated into the sole of the shoe in the toe or tarsal segment of the shoe, and consists of a body with fixed left and right links. The clamping part is fixed to the foot stretcher, the attachment of the clamping part being made directly to the foot stretcher or via a mounting plate to the foot stretcher, and consists of a body with a left and right connection elements with a link, wherein at least one of the connection elements is movable and consists of a snap-in element and a spring element that cooperate with each other via a spherical recess formed on the snap-in element, and a ball head formed on the spring part when the binding is either in the disengaged connection or in the engaged connection. The links of the shoe part are adapted for a form-fit connection with its respective links of the connection elements of the clamping part, so that the rotation of the binding/shoes around the substantially horizontal axis of the connection is allowed to a maximum angle defined by the limiter when the binding is in the engaged connection.

The invention will be described in more detail hereinbelow and illustrated on the figures which show: Figure 1 shows a shoe part of the binding of the invention

Figure 2 shows a clamping part of the invention in a disengaged connection

Figure 3 shows a clamping part of the invention in an engaged connection

Figure 4 shows the binding of the invention in the engaged connection A binding that is adapted for a detachable connection of a shoe to a foot stretcher 20, wherein in an engaged connection (when the connection is engaged) the shoe is fastened to the foot stretcher 20, while in a disengaged connection (when the connection is disengaged), the shoe is separated from the foot stretcher 20, consists of a shoe part 1 and a clamping part 6.

The shoe part 1 shown in Figures 1 and 4 and attachable to the shoe in known ways consists of: a body 2 with two fixed links 3 that are adapted for a form-fit connection with respective links 10 of connection elements 8, 9 of the clamping part 6 and arranged at such a distance from each other that, when the connection is engaged, the fixed links 3 couple in a form-fit manner with the respective links 10 of the connection elements 8, 9 of the clamping part 6 and both links 3 in the engaged connection substantially lie on a horizontal axis x that is substantially perpendicular to the direction of boat's travel.

The clamping part 6 shown in Figures 2, 3 and 4 and attachable to the foot stretcher 20 in known ways, wherein the fastening of the clamping part 6 is made directly onto the foot stretcher 20 or via a mounting plate, not shown in the figure, to the foot stretcher 20, consists of:

a body 7 with connection elements 8, 9 with the links 10, wherein the link 10 is adapted for a form-fit connection with the respective link 3 of the shoe part 1, and at least one connection element 8, 9 is formed movably and consists of a snap-in element 11 and a spring element 12 that co-operate with each other, and the snap-in element 11 is connected with the body 7 of the clamping part 6 via a snap-in axle 9a and movable in an axis y that is parallel to a plane A of the foot stretcher 20, and the spring element 12 is connected with the body 7 of the clamping part 6 via a shaft 12a positioned between the snap-in axle 9a and the opposite connection element 8, 9 and movable in an axis z parallel to the plane A of the foot stretcher 20 such that the connection can be engaged and disengaged, wherein the snap-in element 11 is provided with a step 11a, to which the link 10 is fastened, and the step 11a continues in its bottom portion with an internal arm lib that is provided in the portion co-operating with the spring element 12 with a spherical recess 11c, into which a ball head 13a of the spring element 12 fits, and the shaft 12a of the spring element 12 is preferably centrally provided with a hole for receiving a piston 13 that is provided at the side remote from the spherical recess 11c with the ball head 13a with a limiter 13b, and around the piston 13 between the shaft 12a and the limiter 13b there is placed a spring 14 that pushes the piston 13 outwards, i.e. out of the hole, wherein the snap-in axle 9a and the shaft 12a are located on the body 7 of the clamping part 6 at such a distance from each other that the spring 14 is stretched both in the engaged and disengaged connections in order to push the ball head 13a into the spherical recess 11c. When the connection is engaged, the shoe can rotate preferably around the horizontal axis x of the connection.

The force that needs to be exerted onto the spring 14 to disengage the binding is adjusted by the capacity of the spring 14 of the spring element 12. The capacity of the spring 14 is preferably adjusted depending on the rower's weight.

In a preferred embodiment, one connection element 9 of the clamping part 6 is movable, while the other connection element 8 of the clamping part 6 is fixed. This makes the construction of the binding simpler and the binding itself is more lightweight.

The shoe part 1 is fixed to the toe or tarsal segment of the sole of the shoe in known ways, for example by gluing, screws and the like, or is integrated into the toe or tarsal segment of the sole of the shoe, such that the body 2 with the links 3 protrudes from the plane of the sole of the shoe and the connection can engage and disengage. In a preferred embodiment, the body 2 of the shoe part 1 is secured to the sole of the shoe with four screws, not shown in figures, the body 2 being provided along its outer edges 2a by elongated holes 4 in the shape of interconnected circular sections for receiving screws, wherewith the adjustment and fixing of the position of the shoe part 1 to the sole of the shoe is made possible. This allows the shoe part 1 to move up and down the shoe sole plane and rotate left or right in the shoe sole plane.

Optionally, part of the outer surface of the body 2 of the shoe part 1, i.e. the surface facing away from the sole of the shoe, is configured as a projection 5. This provides the necessary thickness of the body 2 for the formation of the links 3, the links 3 do not get damaged during walking, in addition, the consumption of the material and the weight of the shoe part 1 are reduced. The attachment of the clamping part 6 to the foot stretcher 20 is made by fastening means that allow an independent adjustment of the position of the clamping part 6 for the left and right feet, namely, the movement of the clamping part 6 up and down the plane A of the foot stretcher, rotation to the left or right in the plane A of the foot stretcher, i.e. shift of the axis x of the connection up-down and rotation of the axis x of the connection in the plane A of the foot stretcher, and inclination of the clamping part 6 by rotation in a plane perpendicular to the plane A of the foot stretcher, i.e. the inclination of the axis x of the connection with the rotation perpendicular to the plane A of the foot stretcher. In a preferred embodiment, the body 7 of the clamping part 6 is secured to the foot stretcher with four screws, not shown in figures, the body 7 being provided along its outer edges 7a by elongated holes 15 in the shape of interconnected circular sections for receiving screws, wherewith the movement of the clamping part 6 up and down the plane A of the foot stretcher and rotation to the left or right in the plane A of the foot stretcher, i.e. shift of the axis x of the connection up and down and rotation of the axis x of the connection in the plane A of the foot stretcher are enabled. The inclination of the clamping part 6, i.e. the inclination of the axis x of the connection, is made possible by spacers, not shown in the figures, which are preferably inserted between a screw head and the body 7 of the clamping part 6. In a preferred embodiment, the spacers are washers.

When the clamping part 6 is attached to the mounting plate, the attachment is carried out in the same manner as described above and the mounting plate is then fixed in known ways to the foot stretcher 20, preferably by screwing.

The links 3, 10 are formed as teeth 10a and holes 3a, wherein the shape of the hole 3a corresponds the shape of the tooth 10a, so that a respective form-fit connection of the tooth 10a and its corresponding hole 3a is enabled and the rotation of the binding around the predominantly horizontal axis x when the connection is engaged. For example, when the link 3 on the shoe part 1 is formed in the shape of a hole 3a, the respective link 10 on the clamping part 6 is formed in the shape of a tooth 10a and vice versa, when the link 3 on the shoe part 1 is formed in the shape of a tooth 10a, the link 10 on the clamping part 6 is formed in the shape of a hole 3a. In a preferred embodiment, the links 3 on the shoe part 1 are formed in the shape of a hole 3a, and the links 10 on the clamping part 6 are formed in the shape of a tooth 10a. The tooth 10a is formed integrally from one piece, wherein in the portion where the tooth 10a is attached to the connection element 8, 9 of the clamping part 6 or to the body 2 of the shoe part 1, it is preferably formed in the shape of a cylinder 10b that continues into a tapered portion 10c that is preferably formed as a cone. The tip of the cone is optionally rounded to reduce friction when the connection is engaged or to reduce material wear. Optionally, the tooth 10a is circumferentially provided with at least one groove lOd predominantly in the longitudinal direction of the tooth 10a in order to prevent dirt from being deposited on the outer surface of the tooth 10a in contact with the inner surface of the hole 3a in the engaged position, thereby reducing friction and material wear between the surface of the tooth 10a and the surface of the hole 3a when the connection is engaged.

The shape of the hole 3a with its inner surface corresponds to the shape of the tooth 10a. In a receiving portion 3b, where the tooth 10a is first inserted, the hole 3a is formed with a constant cross-section slightly larger than the cross-section of the cylinder 10b and then extends into the tapered portion 3c, preferably having the shape of a hollow cone. The tip of the hollow cone is optionally rounded to reduce friction when the connection is engaged and to reduce material wear. To facilitate insertion of the tooth 10a into the hole 3a, a portion of the wall of the hole 3a in the receiving portion 3b is provided on the upper side, i.e. on the side facing the sole of the shoe when the connection is engaged, with a cut-out 3d.

The attachment of the links 3, 10 in the shape of the tooth 10a to the connection elements 8, 9 of the clamping part 6 or to the body 2 of the shoe part 1 is carried out in known ways which provide adequate fixing strength, so that the attachment does not loosen, the teeth 10a are preferably screwed and riveted.

A controlled airiness of the binding, i.e. the movement of the shoe to the left or right along the predominantly horizontal axis x, when the connection is engaged, is made possible by the shape of the tooth having a preferably oval or circular cross section and by an adequate shape of the hole that is preferably oval with a conical recess. The airiness or reduced rigidity of the binding reduces a possibility of the rower getting injured due to the constant repetition of the same movement, so the use of the binding according to the invention is particularly recommended in training, especially in multi-member boats. The binding according to the invention allows the rower to move regardless of the shoe being fastened. Optionally, an inner arm lib is provided on the outer surface above the spherical recess 11c with a walk-on element lid in the shape of a bulge with a flat upper surface. In this way, a larger pressing surface is provided, upon which force is exerted when the binding is engaged.

The connection element 8, 9 is optionally provided with an outer arm 16 for engaging or disengaging the connection, preferably for disengaging the connection.

The binding optionally includes a limiter 17 of the angle of shoe rotation with respect to the plane A of the foot stretcher 20 when the connection is engaged. The limiter 17 of the angle of rotation is formed as an oblong body with a flat upper surface. The limiter 17 of the angle of rotation is attached to the foot stretcher 20 above the clamping part 6, viewed in the direction of boat's travel, at such a distance from the clamping part 6 that the sole in the toe or tarsal segment of the shoe is placed on the upper surface of the limiter 17, thereby allowing a uniform distribution of force over the entire upper surface of the limiter 17 of the angle of rotation. The fastening is carried out in known ways which allow for a firm and fixed fastening, for example by screwing, gluing and the like. In a preferred embodiment, the limiter 17 of the angle of rotation is formed in the shape of an elongated square and is fixed to the foot stretcher 20 or to the mounting plate by gluing. The limiter 17 of the angle of rotation allows the adjustment of the inclination of the shoe. This allows for an optimum (adjustable) shoe angle at the beginning of a stroke, which allows an appropriate length of the stroke to be achieved while providing a firm support at the push-off.

The binding is optionally provided with a quick release lever, not shown in the figure, as an additional safety measure for a quick release in the event the rower cannot do so with a leg kick. The lever is fixedly connected to the two outer arms 16 in known ways, wherein by pushing the lever the two outer arms 16 are pushed downwards. This causes the connection elements 8, 9 of the clamping part 6 to spread, thereby permitting the disengagement of the links of the clamping part 6 and the links of the shoe part 1, namely, for example, the two teeth 10a on the clamping part 6 disengage from the holes 3a on the shoe part 1, the connection is thus disengaged and the shoe separated from the foot stretcher 20.

The sole of the shoe can be rigid over the entire surface, but can be in part provided with a flex zone, wherein the flex zone can be formed at any place of the sole. Preferably, the sole of the shoe is rigid over the entire surface, providing an adequate support and even distribution of the support over the entire surface of the sole, thereby reducing the loss of energy during rowing. The sole of the shoe can be made of various materials that provide sufficient strength, rigidity and torsional stability, the sole is preferably made of carbon fibres or materials having a higher elastic modulus.

As the binding allows the shoe to rotate, the shoe rotates during rowing, and since a limiter of the angle of rotation is provided at the front, the string configured to limit the lifting of the heels is absent, there is no need for a flex zone, either.

The materials from which the binding is made are metallic materials and their alloys; the binding is preferably made of steel, aluminium, hardened steel, titanium. For lightweight persons, such as children, the binding may also be made of plastic materials having adequate strength in combination with the materials listed above.

Disengaging the connection

When sufficient force is applied to the binding or when a leg is kicked up or the outer arm 16 is pushed down, the snap-in element 11 rotates around the snap-in axis 9a, the inner arm lib starts lifting, thereby also lifting the spherical recess 11c, while simultaneously with the lifting of the spherical recess 11c the ball head 13a also starts lifting, which fits into the spherical recess 11c, the spring element 12 starts rotating around the shaft 12a and the spring 14 starts to compress, said spring pushing the piston 13 into the hole on the shaft 12a, thereby allowing the ball head 13a and the spherical recesses 11c to move. This causes both connection elements 8, 9 of the clamping part 6 to spread, thereby permitting the disengagement of the links 10 of the clamping part 6 and the links 3 of the shoe part 1, namely, the two teeth 10a on the clamping part 6 disengage from the holes 3a on the shoe part 1, the connection is thus disengaged and the shoe detached from the foot stretcher 20. The disengagement is optionally also possible with a quick release lever.

Engaging the connection

The connection can be engaged either by pushing the upper surface of the inner arm lib or the walk- on element lid or by pushing the outer arm 16 upwards. First, one link 10 of the clamping part 6 is connected in a form-fit manner to the corresponding link 3 of the shoe part 1, for example, the tooth 10a on the clamping part 6 is inserted into the corresponding hole 3a on the shoe part 1. Then sufficient force is applied to the upper surface of the inner arm lib or the walk-on element lid or the outer arm 16 is pushed upwards, wherein the snap-in element 11 rotates around the snap-in axis 9a, the inner arm lib starts sinking, thereby also sinking the spherical recess 11c, while simultaneously with the sinking of the spherical recess 11c the ball head 13a also starts sinking, which fits into the recess 11c, the spring element 12 starts rotating around the shaft 12a and the spring 14 starts to compress, said spring pushing the piston 13 into the hole on the shaft 12a, thereby allowing the ball head 13a and the spherical recesses 11c to move. This causes both connection elements 8, 9 with the links 10 of the clamping part 6 to approach, thereby permitting a form-fit connection of the second link 10 of the clamping part 6 with the belonging link 3 of the shoe part 1 and consequently the engagement of the connection.