CH700681B1 - Apparatus for transmitting force between a foot and a bicycle pedal and method for measuring a force acting on a bicycle pedal in the direction of the pedal shaft power. - Google Patents

Abstract

The invention relates to a device for transmitting power between a foot and a bicycle pedal (110) which has a sensor (114, 133, 134, 144) for measuring a force acting on the pedal (110) in the direction (x) of the pedal axle (111) includes. The sensor (114, 133, 134, 144) is in or on a sole (141) of a shoe (140) or in or on a binding plate (130), which is intended for mounting on a shoe (140), or in or on a binding provided for receiving a binding plate (130) or a shoe (140), or mounted in or on the pedal (110). Furthermore, a method for measuring said force is given.

Description

The invention relates to a device for transmitting power between a foot and a bicycle pedal, which is rotatably mounted about a pedal shaft, with a sensor for measuring a force acting in the direction of the pedal axis on the pedal force. Furthermore, the invention relates to a method for measuring a in a power transmission between a foot and a bicycle pedal, which is rotatably mounted about a pedal axis, acting on the pedal force in the direction of the pedal axis, wherein the force is measured with a sensor.

Modern training methods for cyclists require the knowledge of a variety of parameters, such as speed, distance traveled, speed of the crank, heart rate, altitude and the like. These parameters are often provided by commercially available bicycle computers.

Another important parameter is the force exerted on the pedal, in particular as a function of the angular position of the crank. Here are primarily interested in the normal to the pedal axis forces (y-direction vertical, z-direction horizontal), which serve the propulsion of the bicycle, provided that a normal distance between line of action of the respective force and the bottom bracket is given. Also of interest are forces in the direction of the pedal axis (x-direction), ie horizontally acting forces, which can not be used for propulsion. Although the latter cause no or very little power loss in the physical sense, but the isometric application of a force for the human body is tiring and should therefore be avoided if possible. For detecting the forces acting during cycling some possibilities are known in the prior art.

For example, WO 2006/121 714 discloses a sensor which is integrated into the shoe-mounted binding plate and with which the detection of forces in a plane normal to the pedal axis can be detected.

DE 4 227 586 A1 further discloses an aid for a cyclist to find and train an optimal course of motion. In this case, constructive and destructive force shares that releases the cyclist on the bike, recorded separately and displayed to the cyclist. As a destructive component, the force introduced axially into the pedal crank is also mentioned.

Finally, DE 10 061 923 A1 discloses a further solution for determining the force component introduced axially into a pedal. In this case, force sensors are provided in the storage of the pedals, which detect the pressure forces occurring.

The object of the invention is therefore to provide an easy-to-install sensor for detecting the force acting in the pedal axle force.

According to the invention, this object is achieved by a device having the features of patent claim 1 and / or by a method having the features of patent claim 5.

Accordingly, it is provided in a device of the type mentioned, the sensor: <tb> a) <sep> in or on a sole of a shoe, or <b> <sep> in or on a binding plate intended for mounting on a shoe, or <tb> c) <sep> in or on a binding intended to receive a binding plate or a shoe, or <tb> d) <sep> in or on the pedal, wherein the sensor consists of a piezoelectric crystal and is provided for the power supply of a central processing unit.

Accordingly, it is also provided in a method of the type mentioned to measure the force with a sensor, which: <tb> a) <sep> in or on a sole of a shoe or <b> <sep> in or on a binding plate intended for mounting on a shoe, or <tb> c) <sep> in or on a binding intended to receive a binding plate or a shoe, or <tb> d) <sep> in or on the pedal.

On the one hand, the invention realizes the possibility of being able to measure forces acting in the direction of the pedal axis; on the other hand, the sensors necessary for this purpose are attached to or in components which are easily accessible and can be exchanged very easily. Advantageously, existing wheels or shoes can be easily upgraded to benefit from the advantages of the invention. If the sensors are located, for example, in the shoe or in the binding plate, then the forces can also be measured at different wheels without additional effort. The invention thus makes it possible to detect the forces acting in the direction of the pedal axle with very little technical effort.

Piezocrysts give off a voltage signal during deformation and at the same time have a comparatively good stability. The sensor can therefore be relatively simple. For these reasons, piezoelectric sensors are well suited for use in the device according to the invention.

As mentioned, piezoelectric crystals give off a voltage signal upon deformation. This can not only be used for measurement purposes, but can also be used to supply power to the processing unit. A battery for the processing unit is therefore supported or may be omitted altogether. In this way, the sensors fulfill a double benefit.

Advantageous embodiments and modifications of the invention will become apparent from the dependent claims and from the description in conjunction with the figures of the drawing.

It is advantageous if the sensor for measuring a shear force which acts at the position of the sensor in the direction of the pedal axis, is provided in case a) the sensor is located in the sole, or in case b) the sensor is arranged in the binding plate, or in case c) the sensor is arranged in the binding, or in case d) the sensor is located in the pedal.

In principle, the force can be measured in all elements involved in the power transmission, because occurs in a force component in the x-direction, it is inevitably from the foot to the shoe, the binding plate (if any), the bond (if any) and ultimately transferred to the pedal. In the elements mentioned shear stresses or shear forces occur, which can be evaluated advantageous.

It is also advantageous if the sensor for measuring a pressure force which acts at the position of the sensor in the direction of the pedal axis, is provided in case a) the sensor is mounted at a location of the sole intended for contact with a binding plate, a binding or a pedal, or in the case b) the sensor is attached to a position of the binding plate intended for contact with a shoe or a binding, or in case c) the sensor is attached to a location of the binding intended for contact with a shoe, a binding plate or a pedal, or in case d) the sensor is mounted at a location of the pedal intended for contact with a shoe, a binding plate or a binding. In principle, the force can also be measured at all points which are involved in a force transmission of the forces acting in the x-direction. This is the case, for example, at the interface shoe / binding plate, binding plate / binding and binding / pedal. Pressure force sensors are also readily available and are therefore well suited for use in the inventive device.

In a further advantageous embodiment of the invention, the sensors are connected to a central processing unit, which includes an interface for contactless data transmission. The central processing unit acquires the measured values of the sensors and processes them. For example, measured values can be stored in a memory of the processing unit and later loaded via the radio interface to a PC for further processing. It is also conceivable that the data is sent to a display and / or control unit and displayed there in real time. The functions required for the invention can be embodied in the processing unit in software and / or hardware.

It is also advantageous if a rotation generator is provided on the pedal axle or on the pedal crank (crank axle) for the power supply of the central processing unit. Such a generator makes use of the relative rotation between the outer shell of the pedal and the pedal axle or between the crank axle and the bottom bracket for generating electrical energy according to the generator principle. A battery for the processing unit is therefore supported or may be omitted altogether.

Finally, it is advantageous if an associated angular position of the crank is measured to the force. In this way, it can be measured in which sector which forces occur. It is conceivable that a driver generates useless forces in the x-direction only in a certain sector. In this way, the driving behavior of the cyclist can be improved very targeted.

At this point it should be noted that the variants of the inventive device and the associated advantages relate equally to the inventive method and vice versa.

The above refinements and developments of the invention can be combined in any manner.

The present invention will be explained in more detail with reference to the exemplary embodiments indicated in the schematic figures of the drawing. It shows: <Tb> FIG. 1 <schematically> the parts for power transmission from a foot to a bicycle; <Tb> FIG. 2 <sep> is a first sectional view through a pedal, a binding plate and a shoe; <Tb> FIG. 3 <second> is a second sectional view through a pedal, a binding, a binding plate and a shoe; <Tb> FIG. 4 <sep> the forces on the freed basic body of the binding plate; <Tb> FIG. 5 <sep> the electrical connection of a sensor to a central processing unit.

Fig. 1 shows schematically the parts for power transmission from a foot to a bicycle. In this case, a pedal 10 is mounted in a conventional manner on a pedal axle 11, which in turn is connected to a crank 50. The crank 50 subsequently transmits torque introduced via the pedal 10 to the crank axle 51. A binding 20 may be mounted on the pedal 10. Alternatively, the function of the binding 20 may also be integrated directly in the pedal 10. Furthermore, a binding plate 30 may be mounted on a shoe 40. This binding plate 30 may be releasably connected to the binding 20, or if its function is integrated with the pedal 10, releasably connected to the pedal 10. The function of the binding plate 30 can also be integrated into the shoe 40, such as when the sole of the shoe 40 and the binding plate are injection-molded in one piece.

Fig. 2 shows a first sectional view through a pedal 110, a binding plate 130 and a shoe 140. The function of the binding is taken over in this example in a conventional manner directly from the pedal 110. The pedal 110 consists of a pedal axle 111, bearings 112 mounted thereon, the outer shell 113 and pressure force sensors 114. The binding plate 130 consists of the main body 131, a fitting screw 132, and pressure force sensors 133 and 134. Because of the cutting guide, only one of the two sensors 133 shown. For the following example, however, it is assumed that there is another pressure force sensor on the opposite side of the main body 131. The shoe 140 finally consists of a sole 141, the upper 142, a dowel 143 and pressure force sensors 144th

At this point it is noted that in FIG. 2, several variants are shown simultaneously, which are explained in detail below. It is therefore not mandatory that the illustrated elements are present simultaneously in a device according to the invention. For the attachment of the binding plate 130 with the shoe 140, Fig. 2 shows two variants.

Variant A): The main body 131 of the binding plate 130 is connected by means of fitting screws 143 with the sole 141 of the shoe 140. The dowel screws 143 are thereby shaped so that the forces in the x-direction mainly by positive fit of the fitting screws 143 with the holes in the body 131 and less by friction be transferred between body 131 and sole 141.

Variant B): Like variant A, only the fitting screws 132 are used here for fixing the main body 131 on the sole 141 here. The dowel screw 132 is thus shaped so that the forces in the x-direction mainly by positive engagement of the fitting screws 132 with the holes in the sole 141 and less by friction instead of the fitting screw 143 shown in Fig. 2links 143 be transferred between body 131 and sole 141.

For the arrangement of the sensors 114, 133, 134,144 also arise some variants.

Variation a): In the main body 131 of the binding plate 130 are pressure force sensors 134, arranged here left and right of the hole for the dowel 143. The sensors 134 are capable of measuring the forces transmitted to the binding plate 130 by the mating screws 143 of the shoe 140. The right of the sensors 134 can measure forces in the positive x-direction, the left forces in the negative x-direction. Of course, other (not shown) sensors for measuring the forces in the y-direction and / or z-direction are conceivable. In this variant, it should be noted that the forces are transmitted mainly via the fitting screws 143 and not by friction. At least the forces on the fitting screws 143 and the friction force should be in a known relationship to each other. This variant a) can be used particularly well in combination with variant A). Instead of the fitting screws 143, for example, pins are conceivable that protrude into the corresponding holes.

Variant b): Here, pressure force sensors 144 are arranged left and right of the hole for the dowel screw 132 in the sole 141. In this case, the forces transmitted between shoe 140 and the fitting screws 132 of the binding plate 130 are measured in a similar manner as in variant a). This variant b) can be used particularly well in combination with variant B). The statements made for a) apply mutatis mutandis.

Variant c): Here, pressure force sensors 133 are arranged in the base body 131 of the binding plate 130, in the area of contact with the outer shell 113 of the pedal 110. By the pressure force sensors 133 are here between the binding plate 130 and pedal 110 in the x-direction forces measured. Of course, other (not shown) sensors for measuring the forces in the y-direction and / or z-direction are conceivable. The forces should in turn be transmitted mainly by positive engagement and not by friction. At a minimum, the forces on the lateral flanks of the body 131 and the frictional force between the binding plate 130 and the pedal 110 should be in known relation to one another.

Variant d): Like variant c), only that the forces are measured by means of pressure force sensors 114 in the outer shell 113 of the pedal 110. Otherwise, the statements made for variant c) apply mutatis mutandis.

Fig. 3 now shows a second sectional view through a pedal 210, a binding 220, a binding plate 230 and a shoe 240. The pedal 210 consists of a pedal axle 211 mounted thereon bearings 212, the outer shell 213, screws 214 and a Shear force sensor 215. The binding 220 consists of a base body 221 and a shear force sensor 222 arranged therein. The base body 221 is connected to the outer shell 213 of the pedal 210 by means of the screws 214. The binding plate 230 consists of the base body 231 and a shear force sensor 232 arranged therein. The shoe 240 consists of a sole 241, the upper 242, a shear force sensor 243 arranged in the sole 241, and screws 244.

At this point it should be noted that in FIG. 3, in turn, several variants are shown, which are explained in detail below. It is therefore not mandatory that the illustrated elements are present simultaneously in a device according to the invention. The attachment of the binding plate 130 with the shoe 140 is carried out in the example shown with the aid of screws 244 (variant C), but it is also a screw from above through the sole 241 possible (variant D).

For the arrangement of the sensors 215, 222, 232, 243, there are some variants.

Variant e): In the base body 231 of the binding plate 230, a shear force sensor 232 is arranged, which can detect the shear forces acting in the interior of the main body 231 in the x-direction (or in the y-direction and / or z-direction). This makes it possible to measure the forces acting between shoe 240 and binding 220 and ultimately the forces acting on the pedal 210. Whether the transmission of force between shoe 240, binding plate 230, binding 220 and pedal 210 takes place via friction or via positive locking, is irrelevant here, since the shear forces mentioned occur in the interior of the main body 231 in any case.

Variation f): In the sole 241 of the shoe 240, a shear force sensor 243 is arranged, which measures the shear forces acting in the interior of the sole 241 in the x direction.

Variation g): In the base body 221 of the binding 220, a shear force sensor 222 is arranged, which measures the shear forces acting in the interior of the main body 221 in the x direction.

Variant h): In the outer shell 213 of the pedal 210, a shear force sensor 215 is arranged, which measures the shear forces acting in the interior of the outer shell 213 in the x direction.

For the variants f) -h), what has been said for variant e) applies mutatis mutandis.

As could be shown, the measurement of a force acting in the direction x of the pedal axle 11, 111, 211 on the pedal 10, 110, 210 force on many possibilities is conceivable. The variants A) -D) and a) -h) can be used individually or in any combination. In addition, it is easy for those skilled in the art to adapt the principles shown to other embodiments, without departing from the scope of the invention.

Finally, FIG. 4 shows the forces on the cleared main body 231 of the binding plate 230. On the main body 231, on the one hand, forces act in the y direction, which ultimately serve to propel the bicycle, and forces in the x direction which do not promote propulsion can be used. Although the latter cause no or very little power loss in the physical sense, but the isometric application of a force for the human body is tiring and should therefore be avoided if possible. For the sake of clarity, forces in the z-direction, which also serve for propulsion, are not shown in FIG. 4.

On the main body 231 acts on the bond 220 introduced first and second force in the y-direction F1y and F2y and the first force in the x-direction F1x. Through friction and / or positive locking, another force in the x-direction, namely the third force in the x-direction F3x, is introduced into the base body 231 via the shoe 240. In the main body 231 now (only one) pressure force sensor 133 and a shear force sensor 232 are arranged. Fig. 4 shows only a simplified representation to illustrate the forces acting. Of course, real embodiments may also differ significantly from the one shown.

The pressure force sensor 133 can directly measure the first force in the x-direction F1x (for example, by displacement measurement of a spring-loaded pin, compression of a piezocrystal, etc.) or measure the deformation of the base body 231. In an advantageous embodiment of the invention, for this purpose, the deformation is concentrated at one point, for example by shaping a nose on which the binding 210 and the binding plate 220 touch.

On the other hand, the shear force sensor 232 measures the shear stress or shear force inside the body 231 due to the first and third forces in the x direction F1x and F3x. Symbolically, the first shear force FS1x is above the sensor 232 and the second shear force FS2x is below the sensor 232 located. Advantageously, the sensor 232 is located above the shoulder in the main body 231. Also, the shear forces can be concentrated at one point, such as by a taper in the base body 231, where the sensor 232 is arranged.

Finally, FIG. 5 shows the electrical connection of the representative selected sensor 114 to a central processing unit 60. The processing unit 60 consists of an interface 61 for connecting one or more sensors 114, 133, 134, 144, 215, 222, 232, 243, a central processing unit 62 connected to the interface 61 and a memory 63 connected to the computing unit 62. Finally, an interface 64 for wireless communication is connected to the computing unit 62. By means of the interface 64, the processing unit 60 may also communicate with a remote display / control unit 70 which is mounted about the handlebar of the bicycle, whereas the processing unit 60 may be attached to the pedal 10, 110, 210.

The function of the arrangement shown in Fig. 5 is now as follows:

The sensor 114 supplies a signal, which is a measure of the force acting on it, to the processing unit 60. For example, the signal may be a variable resistor, a variable voltage or even a digital signal. The memory 63 stores program steps and variables which the arithmetic unit 62 processes. The measurement signal is thus received in the example shown, prepared accordingly and sent via the wireless interface 64 to the display / control unit 70. For example, a warning display can be activated there if the measured forces in the x direction exceed a specific threshold value. It is also conceivable that for each measured value of the force, the angular position of the crank 50 is measured and stored. In this way it can be visualized, for example on a PC, in which sector which forces occur. It is conceivable, for example, that a driver generates useless forces in the x-direction, for example, only when pulling up the pedal 10, 110, 210. By visualizing the driving behavior of the cyclist can be improved very targeted. However, the radio interface 64 can be used not only for transmission, but also for receiving, for example to load new firmware into the memory 63. Of course, instead of realizing the invention as software, the invention may be embodied as hardware or a mixture of hardware and software.

In the example shown, the processing unit 60 is supplied with the aid of batteries, not shown, with electrical energy. In an alternative embodiment, alternatively or additionally, the sensors 114, 133, 134, 144, 215, 222, 232, 243 are designed as piezoelectric sensors. Piezocrystals release an electrical voltage during deformation. If the sensors 114, 133, 134, 144, 215, 222, 232, 243 are then deformed by the forces acting between the foot and the pedal axle 11, 111, 210, the resulting electrical voltage can be tapped and used to supply the processing unit 62. Alternatively or additionally, a rotational generator known per se can be provided on the pedal axle 11, 111, 211 or on the crank axle 51 for the power supply of the central processing unit 60. This utilizes the relative rotation between the outer shell 113, 213 of the pedal 10, 110, 210 and pedal axle 11, 111, 211 or between the crank axle 51 and the bottom bracket for generating electrical energy according to the generator principle.

Finally, it should be noted that the inventive device is not bound to the use of a separate bond 20, 220 or in the pedal 10, 110, 210 integrated binding. Rather, the device can only consist of shoe 40, 140, 240 and pedal 10, 110, 210. In this case, for example, a shear force sensor 213 or pressure force sensor 144 in the sole 141, 241 of the shoe 140, 240 or in the outer shell 113, 213 of the pedal 110, 210 can detect the force in the x direction.

Finally, it is also clarified once again that the measurement of the force in the x-direction within the scope of the invention, the (simultaneous) measurement of the force in the y-direction and / or z-direction with the same or other sensors of course not excludes. Rather, the measured values in the y-direction and / or z-direction, in addition to the measured values for the x-direction, can serve to make even better use of the invention.

The invention is particularly suitable for medical, sports medicine and therapeutic applications. Other applications are not excluded.

LIST OF REFERENCE NUMBERS

[0054] <tb> 10, 110, 210 <sep> Pedal <tb> 11, 111, 211 <sep> pedal axle <tb> 112, 212 <sep> bearings <tb> 113, 213 <sep> Outer shell <Tb> 114 <sep> Load Cell <Tb> 214 <sep> Bolt <Tb> 215 <sep> shear force sensor <tb> 20, 220 <sep> bond <tb> 221 <sep> body bond <Tb> 222 <sep> shear force sensor <tb> 30, 130, 230 <sep> binding plate <tb> 131, 231 <sep> Basic body binding plate <Tb> 132 <sep> Passschraube <tb> 133, 134 <sep> Compression force sensor <Tb> 232 <sep> shear force sensor <tb> 40, 140, 240 <sep> shoe <Tb> 141.241 <sep> shoe sole <tb> 142, 242 <sep> Upper <Tb> 143 <sep> Passschraube <Tb> 144 <sep> Load Cell <Tb> 243 <sep> shear force sensor <Tb> 244 <sep> Bolt <Tb> 50 <sep> Crank <Tb> 51 <sep> crank axle <Tb> 60 <sep> processing unit <tb> 61 <sep> Interface for sensors <tb> 62 <sep> Central processing unit <Tb> 63 <sep> Memory <tb> 64 <sep> wireless interface <Tb> 70 <sep> display / control unit <tb> F1x <sep> first force in x-direction <tb> F1y <sep> first force in y-direction <tb> F2y <sep> second force in y-direction <tb> F3x <sep> force transmitted by the shoe in x-direction <tb> FS1x <sep> first shear force on the sensor in x-direction <tb> FS2x <sep> second shear force on the sensor in x-direction

Claims (5)

A device for transmitting power between a foot and a bicycle pedal (10, 110, 210) rotatably supported about a pedal axle (11, 111, 211), comprising: A sensor (114, 133, 134, 144, 215, 222, 232, 243) for measuring a force acting in the direction (x) of the pedal axle (11, 111, 211) on the pedal (10, 110, 210), in which a) the sensor (144, 243) in or on a sole (141, 241) of a shoe (40, 140, 240), or b) the sensor (134, 232) in or on a binding plate (30, 130, 230) which is intended for mounting on a shoe (40, 140, 240), or c) the sensor (222) in or on a binding (20, 220) which is provided for receiving a binding plate (30, 130, 230) or a shoe (40, 140, 240), or d) the sensor (114, 215) is mounted in or on the pedal (10, 110, 210), and - means for measuring a force associated with the angular position of the crank (50), characterized in that the sensor (114, 133, 134, 144, 215, 222, 232, 243) consists of a piezocrystal and for the power supply to a central processing unit ( 60) is provided. 2. Apparatus according to claim 1, characterized in that the sensor (215, 222, 232, 243) for measuring a shear force (FS1x, FS2x), which at the position of the sensor (215, 222, 232, 243) in the direction ( x) the pedal axle (11, 111, 211) acts is provided, wherein in the case a) the sensor (243) in the sole (141, 241) is arranged, or in case b) the sensor (232) is arranged in the binding plate (30, 130, 230), or in case c) the sensor (222) is arranged in the binding (20, 220), or in the case d) the sensor (215) in the pedal (10, 110, 210) is arranged. 3. Apparatus according to claim 1, characterized in that the sensor (114, 133, 134, 144) for measuring a pressure force (F1x), which at the position of the sensor (114, 133, 134, 144) in the direction (x) the pedal axle (11, 111, 211) acts is provided, wherein in the case a) the sensor (114) is mounted at a location of the sole (141) which is suitable for contact with a binding plate (30, 130, 230), a binding (20, 220) or a pedal (10, 110, 210) is provided, or in case b) the sensor (114) is mounted at a location of the binding plate (30, 130, 230) intended for contact with a shoe (40, 140, 240) or a binding (20, 220), or in case c) the sensor is mounted at a location of the binding (20, 220) suitable for contact with a shoe (40, 140, 240), a binding plate (30, 130, 230) or a pedal (10, 110 , 210), or in case d) the sensor is mounted at a location of the pedal (10, 110, 210) which is suitable for contact with a shoe (40, 140, 240), a binding plate (30, 130, 230) or a binding (20 , 220) is provided. 4. Device according to one of claims 1 to 3, characterized in that the sensor (114, 133, 134, 144, 215, 222, 232, 243) is connected to the central processing unit (60) having an interface (64) for contactless data transmission. 5. A method for measuring a at a power transmission between a foot and a bicycle pedal (10, 110, 210) which is rotatably mounted about a pedal axis (11, 111, 211), on the pedal (10, 110, 210) acting force in the direction (x) of the pedal axle (11, 111, 211) and a force associated with the angular position of the crank (50), wherein the force with a sensor (114, 133, 134, 144, 215, 222, 232, 243) measured will, who: a) in or on a sole (141, 241) of a shoe (40, 140, 240) or b) in or on a binding plate (30, 130, 230), which is intended for mounting on a shoe (40, 140, 240), or c) in or on a binding (20, 220), which is provided for receiving a binding plate (30, 130, 230) or a shoe (40, 140, 240), or d) is mounted in or on the pedal (10, 110, 210), characterized in that the sensor (114, 133, 134, 144, 215, 222, 232, 243) consists of a piezocrystal and the sensor (114, 133, 134, 144, 215, 222, 232, 243) energizes the central processing unit (60).