WO2009028933A1

WO2009028933A1 - Human poviered vehicle

Info

Publication number: WO2009028933A1
Application number: PCT/NL2008/050245
Authority: WO
Inventors: Shifan Hu
Original assignee: Five Stars Food Equipment B.V.
Priority date: 2007-08-28
Filing date: 2008-04-24
Publication date: 2009-03-05
Also published as: NL2000834C2; NL2001518C2

Abstract

A human powered vehicle e.g. a cycle (1), a pedal mechanism which comprises two rotatable pedal arm constructions, each comprising at least two pedal arms (2) which are coupled to each other such that' they have a constant phase difference and are connected on their free end zones to a pedal carrier (34). The distance between the rotation bearings (3) carrying the pedal arms relative to the frame (31) is smaller than the length of the pedal arms, and the arms have a form and position relative to the rotation bearings present on the frame such that at each angular position they are at some distance from each other.

Description

HUMAN POWERED VEHICLE

The invention relates to a human powered vehicle, for instance a cycle, comprising: a frame assembled for instance from bars; a seat element for a user, such as a saddle, carried by the frame; at least one first wheel which is connected by a rotation bearing to the frame and the position of which can be continuously adjusted by a user by means of a handlebar; and at least one second wheel which is connected by a rotation bearing to the frame and which can be driven rotatingly by a user with muscle power by means of a rotatable pedal mechanism which is coupled for force transmission to the or each second wheel via a transmission; which pedal mechanism comprises: a substantially horizontal shaft construction mounted rotatably on said frame; two pedal arm constructions extending in mutually opposite directions more or less in transverse direction relative to the shaft construction and each bearing a pedal at their free end; such that pressure forces exerted on the pedals by a user are transmitted from the pedal mechanism via the transmission to the or each first wheel.

Such a human powered vehicle is for instance known from BE-A-853 784, GB-A-2 358 842 and US-A-3 913 944.

All vehicles according to the above stated prior art are constructed such that the length of the pedal arms is smaller than the mutual distance between adjacent rotation bearings present on the frame. This is technically a logical choice per se, since it does after all prevent the pedal arms making contact with each other. The great drawback of this technical choice is however that the pedal arm construction takes up a great deal of space and is not very attractive from an aesthetic viewpoint. In the light of this, it is an object of the invention to embody a vehicle of the type stated in the preamble such that the described drawbacks of the prior art are obviated. In this respect the human powered vehicle according to the invention has the feature that each pedal arm construction comprises at least two pedal arms connected by respective rotation bearings to the frame, the pedal arms are coupled to each other such that they have a constant phase difference and are connected on their free end zones to a pedal carrier by means of respectively a further rotation bearing and a further coupling with at least a rotation degree of freedom, for instance a rotation bearing, a sliding coupling or a connection with variable length, such as a draw spring, such that, at each angular position of the pedal arms, the imaginary plane through the further rotation bearing and the rotation axis or rotation zone defined by the further coupling makes a substantially unambiguously determined angle with the plane defined by the central axes of the rotation bearings carrying the pedal arms relative to the frame, which pedal carrier carries a respective pedal, wherein the distance between the rotation bearings carrying the pedal arms relative to the frame is smaller than the distance between each of these rotation bearings and the further rotation bearing or the further coupling; and wherein the arms have a form and position relative to the respective rotation bearings present on the frame such that at each angular position they are at some distance from each other.

A very compact and aesthetically attractive embodiment is obtained with this construction according to the invention.

The vehicle can for instance have the special feature that the pedal arms each comprise at least one at least more or less straight arm part, wherein the corresponding arm parts of the at least two pedal arms form an angle with the central axis of the relevant rotation bearings present on the frame which has a value between 90° and 180°, preferably 100° and 140°.

The phase difference will generally have a somewhat limited value. Because in the case of a phase difference varying from zero the distance between the effective ends of the pedal arms is not constant, means are necessary to accommodate the differences in distance which occur.

In a specific embodiment the vehicle has the special feature that the phase difference has the value zero. A phase difference of zero implies that corresponding arms are mutually parallel in each angular position.

According to another aspect of the invention, the vehicle can have the special feature that the at least two pedal arms have equal lengths. Pedal arms of equal length can be disposed rotatably with a phase difference having the value zero or a phase difference having a value varying from the value zero.

In the case where the phase difference is zero and the two pedal arms are of equal length, the vehicle can have the special feature that the two pedal arms and the pedal carrier form a parallelogram construction, whereby in each angular position of the pedal arms the pedal carrier extends parallel to the flat plane defined by the two rotation bearings.

According to a specific aspect of the invention, the vehicle has the special feature that each pedal occupies a fixed position relative to the pedal carrier.

When the above described parallelogram construction is used, the pedal carriers always have the same position relative to the frame. It is perceived by some users as pleasing when the pedals, depending on the momentary angular position and the pressure force to be exerted, can be adjusted to the wishes of the user in respect of the angular position of the pedals. In this respect the vehicle according to the invention can also have the special feature that each pedal is pivotable around a substantially horizontal axis through a certain angle around a rest position. This latter embodiment can advantageously have the special feature that the foremost zone of each pedal is pivotable downward through a maximum first angle a, and the rearmost zone of each pedal is pivotable downward through a maximum second angle b. Such a vehicle preferably has the special feature that a and/or b is adjustable.

Strongly recommended is an embodiment in which a > b.

Orienting tests have shown that this latter embodiment can preferably be embodied such that a is in the order of a maximum of 90° and b is in the order of a maximum of 20°.

In a determined embodiment the vehicle has the special feature that a is in the order of (40 ± 10°). According to yet another aspect of the invention, the vehicle has the special feature that b is in the order of (5 ± 3°) .

A vehicle with pivotable pedals preferably comprises soft stops, such as flexible plates or springs, for the purpose of bounding the angle of pivot.

According to a further aspect of the invention, the vehicle can be embodied such that the transmission comprises an endless element, such as a belt, a toothed belt or a link chain, which element is trained on one side around a first drive wheel, for instance a toothed wheel, this first drive wheel being coupled for rotation to the shaft construction, and is trained on the other side around a second drive wheel, for instance a toothed wheel, this second drive wheel being coupled to the at least one second wheel.

According to yet another aspect of the invention, the vehicle has special feature that the transmission comprises a shaft of cardan type.

According to yet another aspect of the invention, the vehicle is embodied such that, at the position of the shaft construction as well as at the position of the drive of the at least one second wheel, the transmission comprises a right-angled coupling, between both of which right-angled couplings there extends a substantially torsionally rigid transmission rod. As a further alternative, the vehicle can have the special feature that the transmission comprises a flexible shaft.

In yet another variant the vehicle has the special feature that the pedal mechanism comprises at least one first crank, the free end zone of which comprises a first rotation bearing; at least one second wheel is coupled to at least one second crank; the first crank has an arm with a length as great as that of the arm of the second crank; and an at least tensively strong, elongate, force- transmitting element mutually connects corresponding first and second cranks via the first and second rotation bearings.

With this latter embodiment the transmission construction is substantially simplified compared to known vehicles, the transmission can be manufactured in relatively light and inexpensive form and is practically maintenance-free .

It would in principle be possible to suffice with only a tensively strong element, for instance a steel wire or the like, particularly in the case where the transmission comprises two such elements operating in opposite phase to each other. These tensively strong elements can be tautened and so hold each other continuously tensioned, whereby the angular positions of the corresponding cranks will always correspond exactly with each other.

Particularly in the case where use is made of only one elongate, force-transmitting element it is strongly recommended that the or each force-transmitting element also has pressure strength. This latter embodiment can advantageously have the special feature that the force-transmitting element with tensile and pressure strength is coupled via respective rotation bearings to both pedal arms.

In a determined embodiment the vehicle according to the invention can have the special feature that the or each force-transmitting element is a solid rod, for instance of steel or a fibre-reinforced plastic.

Other than in the case of a usual chain transmission, wherein the force-transmitting chain is in a state of practically continuous movement, use is made according to the invention of a reciprocally moving element. So that there is only negligible effect from the associated accelerations and decelerations, it is recommended that, while retaining its required technical qualities, this element is light. In this respect it is recommended according to the invention that the force- transmitting element has a profile increasing the buckling resistance, for instance an I-profile.

Alternatively, it is possible to opt for the or each force-transmitting element to be a hollow rod. A technically attractive solution lies in the hollow rod consisting substantially of composite material, for instance comprising carbon or glass fibres embedded in an epoxy material. In a preferred embodiment the vehicle according to the invention has the feature that the second crank engages on the input to a hub gear, the output of which is connected to at least one second wheel.

Use can be made of separate cranks. Simpler and material-saving is an embodiment in which a first crank forms part of the relevant pedal arm construction.

In a specific embodiment the vehicle has the special feature that the central axis of the rotation bearing connecting the force-transmitting element to the pedal arm lies some distance relative to the plane of rotation of the pedal arm from the connecting line between the rotation bearing connecting the pedal arm to the frame and the rotation bearing connecting the pedal carrier to the pedal arm. Such a construction avoids a "dead centre" in the drive.

It is not essential under all conditions for the pedal to be physically separated from the pedal carrier. It is possible to envisage embodiments of the human powered vehicle according to the invention in which the pedal carrier also forms the pedal. The invention will now be elucidated on the basis of the accompanying drawings of several exemplary embodiments, to which the invention is not limited. In the drawings: figure 1 shows a partial side view of a cycle with single-sided, straight drive; figure 2 shows a horizontal section through the cycle according to figure 1; figure 3 is a side view of a cycle with a dual, thus both left and right, drive; figure 4 shows a horizontal section through the cycle according to figure 3; figure 5 is a perspective view of a detail of the pedal arm construction and associated transmission of the embodiment according to figures 1 and 2; figure 6 is a top view of a pedal construction; figure 7 is a side view of a pedal construction; figure 8 is a perspective view of a detail of the crank drive of the rear wheel of the cycle according to figures 1 and 2 in combination with a hub gear; figure 9 shows a view corresponding with figure 1 of a variant; figure 10 shows a view corresponding with figure 2 of the variant of figure 9; figure 11 shows a view corresponding with figure 1 of yet another embodiment; figure 12 shows a view corresponding with figure 2 of the embodiment of figure 11; figure 13 is a view corresponding with figure 1 of yet another embodiment; figure 14 is a view corresponding with figure 2 of the embodiment of figure 13; figure 15 shows a view corresponding with figure 1 of yet another variant; figure 16 shows a view corresponding with figure 2 of the variant of figure 15; figure 17 shows a view corresponding with figure 6 of an alternative embodiment of a pedal construction; and figure 18 shows a view corresponding with figure 7 of the embodiment of figure 17. Figure 1 shows a cycle 1 with a single-sided drive according to the invention. In this embodiment a frame 31 assembled from bars bears, via two crankshaft bearings 3, two mutually parallel pedal arms 2 which carry on their free end via a pedal carrier 34 a pedal 4 with a limited pivotability to be described hereinbelow. In a manner to be further described the pedal arms are coupled rotatably to a drive rod 5 which is connected at its other end to a crank 6 for the purpose of driving a driven rear wheel 32.

Figure 2 shows that use is made on the left-hand side of the cycle of a similar pedal arm construction, although without making use of a drive rod. It will be apparent that another form of the pedal arm construction is also possible on the left-hand side. For the sake of symmetry and from an aesthetic viewpoint the drawn design is recommended.

It will be apparent that, using the construction according to figures 1 and 2, the right-hand pedal exerts a force on the rear wheel by means of a tensile force in drive rod 5 during cycling in forward direction, while rod 5 is subjected to a pressure force when a forward force is exerted on the left-hand pedal. In this embodiment the rod must therefore be able to withstand both forces.

This is different in the case of the cycle 33 as according to figures 3 and 4, in which use is also made on the left-hand side of a drive rod and associated crank. This second drive rod is designated with reference numeral 7, while the second crank coupled to the rear wheel is designated with reference numeral 8.

In this embodiment rods 5 and 6 could be replaced by elements having only tensile strength, for instance tensioned steel cables, so that the one and the other cable are subjected alternately to a tensile force, whereby the user, by exerting an alternating force on the left and right-hand pedal, places the left and right-hand mechanism under strain of tension and sets the rear wheel into rotation. Figure 5 shows the detail V of figure 1, i.e. a part of the force-transmitting mechanism of cycle 1. This figure shows that the pedal arms 2 in dual form are coupled at their free ends by a pedal carrier 34 which supports pedal 4. The hollow drive rod 5 of composite material is connected at a distance from rotation bearings 3 to pedal arms 2 by means of respective rotation bearings which are not shown but nevertheless designated 35.

Figures 6 and 7 show the manner in which the upper plate or footplate 14 of a pedal 4 is supported by pedal arms 2 via a pedal carrier 34.

Use is made of a pedal carrier 34 for the pedal, this pedal carrier being bearing-mounted on both pedal arms 2. Pedal carrier 34 bears a first upright flange 12 and a second upright flange 13. Footplate 14 bears a first flange 15 and a second flange 16. Footplate 14 is coupled to pedal carrier 34 by means of a shaft 17. A for instance rubber-elastic block, consisting for instance of an elastomer cushion, serves as soft stop to bound the pivoting movement of footplate 14, which is defined by shaft 17, relative to pedal carrier 34 to a value in the order of magnitude of 20° in both directions. Both these approximately extreme pivoting positions are indicated in figure 7 with reference numerals 19 and 20. Figure 8 shows that, according to another aspect of the invention, rear wheel 32 can comprise a hub gear 21, the output of which directly supports spokes 36 of wheel 32, and the input shaft of which supports crank 6. The acceleration unit accommodated in the hub gear is adjustable by means of an external operating element 22 which is connected via a bowden cable 37 to a control handle, which is per se known and which in a known cycle is usually mounted on the handlebar.

The descried limited pivotability of the pedals in a preferred embodiment of the invention has the effect of greatly improving the cycle comfort. Other than in the case of a usual cycle, wherein the pedals are disposed for completely free rotation relative to the pedal arms, forces can be exerted in a manner which is perceived as very agreeable and comfortable, wherein there is never any danger of the pedals revolving wholly out of control. Although embodied in wholly different manner, this aspect is to some extent functionally comparable to the use of the toe-clips on race cycles, wherein a certain limitation of the pivotability of the pedals is also realized. Relatively large pedal surfaces are further shown in the drawn embodiments . These pedal surfaces, which are larger than usual, result in a larger contact area between the foot soles of a user and the pedals, and therefore a better pressure distribution on the soles.

Figure 9 shows a cycle 1, the pedal arms of which have a clearly shown bend. This means that the central axis of the rotation bearing connecting the force- transmitting element 5 to pedal arm 42 lies some distance from the connecting line between the rotation bearing or crankshaft bearing 3 connecting pedal arm 42 to frame 31 and the rotation bearing connecting pedal carrier 43, also pedal, to pedal arm 42. This bent construction achieves that there is no risk of a dead centre in the drive.

As shown particularly clearly in figure 10, a force- transmitting rod 5 with tensile strength and pressure strength is situated on only one side. It will however be apparent that the principle described here can also be applied to a double-sided drive.

Described below is that pedal 43 has a certain freedom of movement. Reference is made in this respect to figures 17 and 18.

Figure 11 shows a cycle in which pedal arms 44 each consist of one part and are connected only at their ends to rotation bearings. The rearmost crankshaft, which is connected to the rearmost arms 44, is connected to a front chain wheel 45 of small diameter. Via a chain 46 this front chain wheel 45 drives a rear chain wheel 47 which, in general and in preference via a hub gear, drives rear wheel 32.

Figure 13 shows a cycle with a cardan drive. In this embodiment the transmission does not comprise a chain as in the embodiment according to figures 11 and 12, but a cardan shaft bearing a bevel gear at both ends. A foremost bevel gear 48 is connected to the crankshaft of the rearmost pedal arms 44, whereby cardan shaft 49 is rotated when pedal arms 44 are caused to rotate. Via a rearmost bevel gear connected for instance via a hub gear to rear wheel 32, the rearmost bevel gear 51 drives rear wheel 32. A casing 50 in the form of a substantially stiff tube protects the cardan shaft 49 when rotating with force against outside influences and unintended contact with external elements.

Figure 15 shows a cycle according to the invention, wherein use is made of a chain wheel which is large compared to the embodiment of figures 11 and 12 and which for instance has the same diameter as usual cycles.

The central axes of the crankshaft bearings combined to form a unit 56 have a large mutual distance such that chain wheel 55 fits therebetween. See particularly figure 16 in this respect.

Figure 17 shows a top view of the construction of an alternative pedal. The pedal arms are designated with reference numeral 57 and the footplate with reference numeral 58.

Reference numeral 59 indicates the supports on the footplate for connection to the crankshaft. Particular reference is made in this respect to figure 18. A rotation sleeve is designated with reference numeral 60. A tongue 61 is arranged on sleeve 60. A guide bolt 62 in arcuate form is connected to the footplate. An upper compression spring or draw spring 63 extends between tongue 61 and footplate 58. Extending between tongue 61 and a self-locking nut 65 is respectively a lower compression spring or draw spring 64. A soft stop is hereby realized which urges footplate 58 to its stable rest position indicated with full lines. When a certain pedalling force is exerted which causes pedal 58 to pivot in the direction of one of the positions indicated with broken lines, springs 63 and 64 are compressed and expanded. In the case where the springs are arranged without bias, one of the springs is compressed and the other spring retains its length at rest. Attention is drawn to the fact that the embodiments according to figures 9-16 are all provided with such a soft stop and pivotable pedals. In order to also be able to make full use of the pivotability in downward direction of the pedal on the rear side, the pedal can be disposed more or less symmetrically around its rear pivot axis, other than is drawn in figure 15. This could be compared to the structure according to figures 6 and 7 in which, although the suspension of the pedal is different, the pedal displays a certain pivotability and is disposed at least more or less symmetrically around the central rotation sleeve.

As shown schematically and without any detail in figures 9, 11, 13 and 15, pedal carrier 43, also pedal, is pivotally connected on its rear side to the rear pedal arm 42 by means of a rotation bearing. On the front side pedal carrier 43 bears a guide bracket which is modelled in arcuate form and is guided through an eye mounted rotatably at the end of the foremost pedal arm 42. Pedal carrier 43 is thus pivotable around the pivot axis of the rotation bearing on the free end of the rear pedal arm 42.

It is noted that this is also the case for pedal arms 44 according to figures 11, 13 and 15. The structure in question can be seen in more detail in figure 18, from which it is also apparent that the pivotability of the pedal carrier realized with this structure is bounded by spring means 63, 64, which define the rest position such that in the non-loaded situation the pedal carrier 58 (see figure 18) always moves parallel to itself during rotation of the relevant pedal arms 57. The construction can also be embodied such that the guide bracket and the eye are interchanged . Attention is drawn to the fact that the invention is not limited to cycles with the general design shown in the drawings. Three-wheelers and four-wheelers can also find application within the scope of the invention. The figures show cycles with a frame 31 extending substantially in one flat main plane with a saddle 38 and a handlebar 39 to which a front wheel 41 is directly coupled for pivoting in a bearing 40 such that a user can steer the cycle in any desired direction. There are however also human powered vehicles of other type, such as reclining cycles with two or three wheels, three and four-wheel cycle taxis, delivery cycles and the like, which have a construction differing substantially from that of the embodiments drawn and described herein, but to which the principles of the invention can equally be applied. The invention also relates to such applications. Finally, attention is drawn /to the fact that the invention is also applicable to for instance home-trainers, which in the context of the present invention can also be deemed as a "human powered vehicle".

Claims

1. Human powered vehicle, for instance a cycle, comprising: a frame assembled for instance from bars; a seat element for a user, such as a saddle, carried by the frame; at least one first wheel which is connected by a rotation bearing to the frame and the position of which can be continuously adjusted by a user by means of a handlebar; and at least one second wheel which is connected by a rotation bearing to the frame and which can be driven rotatingly by a user with muscle power by means of a rotatable pedal mechanism which is coupled for force transmission to the or each second wheel via a transmission; which pedal mechanism comprises: a substantially horizontal shaft construction mounted rotatably on said frame; two pedal arm constructions extending in mutually opposite directions more or less in transverse direction relative to the shaft construction and each bearing a pedal at their free end; such that pressure forces exerted on the pedals by a user are transmitted from the pedal mechanism via the transmission to the or each first wheel; characterized in that each pedal arm construction comprises at least two pedal arms connected by respective rotation bearings to the frame, the pedal arms are coupled to each other such that they have a constant phase difference and are connected on their free end zones to a pedal carrier by means of respectively a further rotation bearing and a further coupling with at least a rotation degree of freedom, for instance a rotation bearing, a sliding coupling, a connection with variable length, such as a draw spring, such that, at each angular position of the pedal arms, the imaginary plane through the further rotation bearing and the rotation axis or rotation zone defined by the further coupling makes a substantially unambiguously determined angle with the plane defined by the central axes of the rotation bearings carrying the pedal arms relative to the frame, which pedal carrier carries a respective pedal, wherein the distance between the rotation bearings carrying the pedal arms relative to the frame is smaller than the distance between each of these rotation bearings and the further rotation bearing or the further coupling; and wherein the arms have a form and position relative to the respective rotation bearings present on the frame such that at each angular position they are at some distance from each other.

2. Vehicle as claimed in claim 1, wherein the pedal arms each comprise at least one at least more or less straight arm part, wherein the corresponding arm parts of the at least two pedal arms form an angle with the central axis of the relevant rotation bearings present on the frame which has a value between 90° and 180°.

3. Vehicle as claimed in claim 1 or 2, wherein the phase difference has the value zero.

4. Vehicle as claimed in any of the foregoing claims, wherein the at least two pedal arms have equal lengths .

5. Vehicle as claimed in claims 1, 3 and 4, wherein the frame, the two pedal arms and the pedal carrier form a parallelogram construction, whereby in each angular position of the pedal arms the pedal carrier extends parallel to the flat plane defined by the two rotation bearings .

6. Vehicle as claimed in any of the foregoing claims, wherein each pedal occupies a fixed position relative to the pedal carrier.

7. Vehicle as claimed in any of the claims 1-6, wherein each pedal is pivotable around a substantially horizontal axis through a certain angle around a rest position.

8. Vehicle as claimed in claim 7, wherein the foremost zone of each pedal is pivotable downward through a maximum first angle a, and the rearmost zone of each pedal is pivotable downward through a maximum second angle b.

9. Vehicle as claimed in claim 8, wherein a and/or b is adjustable.

10. Vehicle as claimed in claim 9, wherein a > b.

11. Vehicle as claimed in claim 10, wherein a is in the order of a maximum of 90° and b is in the order of a maximum of 20°.

12. Vehicle as claimed in claim 10, wherein a is in the order of (40 ± 10°) .

13. Vehicle as claimed in claim 10, wherein b is in the order of (5 ± 3°) .

14. Vehicle as claimed in any of the claims 7-13, comprising soft stops, such as flexible plates or springs, for the purpose of bounding the angle of pivot.

15. Vehicle as claimed in any of the foregoing claims, wherein the pedal mechanism comprises at least one first crank, the free end zone of which comprises a first rotation bearing; at least one second wheel is coupled to at least one second crank; the first crank has an arm with a length as great as that of the arm of the second crank; and an at least tensively strong, elongate, force- transmitting element mutually connects corresponding first and second cranks via the first and second rotation bearings.

16. Vehicle as claimed in claim 15, wherein the central axis of the rotation bearing connecting the force-transmitting element to the pedal arm lies some distance from the connecting line between the rotation bearing connecting the pedal arm to the frame and the rotation bearing connecting the pedal carrier to the pedal arm.