The invention relates to a treadmill vehicle according to the preamble of the appended independent claim 1. In other words, the invention relates to a treadmill vehicle, comprising:

- a vehicle frame;

- at least two vehicle wheels arranged and configured for movement of the treadmill vehicle over a ground;

- a treadmill, which comprises an endless moving belt, which is passed over two return-pulleys having mutually parallel return-pulley axes, and which is arranged and configured for a user of the treadmill vehicle to walk in a forward walking direction on the endless moving belt in a treadmill fashion, while at the same time the treadmill vehicle is performing said movement over the ground in a forward driving direction being the same as the forward walking direction, wherein said walking direction is defining a backside and a frontside of the treadmill in the sense that said walking direction is directed from said backside towards said frontside;

- a force transmission mechanism arranged and configured for force transmission between the endless moving belt of the treadmill and at least one treadmill-coupled vehicle wheel of said at least two vehicle wheels; and

- an electromotor arranged and configured for driving said movement of the treadmill vehicle over the ground.

Such a treadmill vehicle is known from NL1039126C. During normal operation condition of this known treadmill vehicle, the treadmill vehicle is driving in said forward driving direction, while at the same time the electromotor is in operation, and while at the same time a user is walking in said forward walking direction on the endless moving belt. In a practical design of this known treadmill vehicle, the treadmill vehicle is provided with a braking device being actuatable by a brake handle on the handlebar of the treadmill vehicle. In this practical design, when a user actuates the brake handle, the braking device not only brakes a wheel of the treadmill vehicle, but also automatically disables the electromotor. Hence, when the user actuates the brake handle, the treadmill vehicle safely stops.

However, a drawback of this known treadmill vehicle with the mentioned braking device is, that when the user does not actuate the braking device, the electromotor remains in operation. This may lead to dangerous situations, for example when a user falls or steps off the vehicle, without actuating the brake handle. One dangerous situation may for example occur when a user is walking too close to the backside of the treadmill. This may lead to unstability of the user, while the user is uncapable of actuating the brake handle anymore.

It is an object of the invention to provide a solution according to which the abovementioned dangerous situations are prevented.

For that purpose the present invention provides a treadmill vehicle according to the appended independent claim 1. Preferable embodiments of the invention are provided by the appended dependent claims 2-7.

Accordingly, the invention provides a treadmill vehicle according to the above-identified preamble of independent claim 1, wherein the treadmill vehicle according to the characterizing portion of independent claim 1 is further characterized by

- an abnormality sensor arranged and configured for detecting at least one abnormal operation condition of the treadmill vehicle during operation of the electromotor, wherein said abnormal operation condition corresponds to a situation in which the user is unsafely walking on the endless moving belt or a situation in which there is no user on the endless moving belt; and

- a control circuitry arranged and configured for disabling the operation of the electromotor in response to the abnormality sensor detecting said at least one abnormal operation condition. Thanks to said abnormality sensor and said control circuitry, the abovementioned dangerous situations are prevented in that, upon

occurrence of unsafely walking or a user leaving the moving belt, the electromotor is automatically disabled even when the user does not actuate the brake handle.

In a preferable embodiment of the invention, said unsafely walking of the user on the endless moving belt comprises walking too close to the backside of the treadmill. In this preferable embodiment the electromotor is automatically disabled when the abnormality sensor detects that the user is walking too close to the backside of the treadmill. This automatical disablement of the electromotor leads to slowing down the movement of the vehicle over the ground. In view of the abovementioned force transmission mechanism for force transmission between at least one vehicle wheel and the moving belt, the automatical disablement of the electromotor also leads to slowing down of the moving belt. Hence, this preferable embodiment effectively protects the user from getting into trouble near the backside of the treadmill.

In a further preferable embodiment of the invention,

- the endless moving belt has an upper trajectory, which is extending in-between the upper sides of the respective two return-pulleys, and a lower trajectory, which is extending in-between the lower sides of the respective two return -pulleys;

- the treadmill further comprises a supporting structure, which is arranged and configured for supporting the endless moving belt in its upper trajectory from below; and

- the abnormality sensor is arranged and configured for detecting said at least one abnormal operation condition of the treadmill vehicle based upon a detected loading, which the endless moving belt exerts onto the supporting structure. Such an application of such a supporting structure and such a loading detection is very reliable for the purpose of detecting situations of unsafe walking on the moving belt or of absence of a user on the moving belt.

In principle, the abnormality sensor may comprise at least one load cell arranged and configured for detecting said loading. Such an application of such at least one load cell is very effective for detecting various kinds of abnormal operation conditions of the treadmill vehicle.

In a further preferable embodiment of the invention, at least part of the supporting structure is resiliently moveable, within a movement range, relative to the vehicle frame by at least one spring, wherein the abnormality sensor is arranged and configured to detect said at least one abnormal operation condition of the treadmill vehicle based on relative movement positions within said movement range. Such an application of such a resilient moveability and such at least one spring provides reliability together with ease in maintenance and repairability.

In a further preferable embodiment of the invention, said resilient moveability is realized in that said supporting structure comprises a supporting frame, which is hingeable relative to the vehicle frame about a hinge axis, which is parallel to the return-pulley axes, and wherein the hinge axis is located closer to said backside of the treadmill than to said frontside of the treadmill. Such an application of such a hingeable

supporting frame is very reliable in detecting that the user is walking too close to the backside of the treadmill, while at the same time it maintains the abovementioned ease in maintenance and repairability.

In a further preferable embodiment of the invention, said supporting structure further comprises supporting rollers, which are attached to said supporting frame in a bearing-mounted manner, and which are arranged side by side, mutually parallel, and parallel to the two return- pulley axes, and which are further arranged so as to rollingly support the endless moving belt in its upper trajectory from below during operation of the treadmill vehicle. Such an application of such supporting rollers provides reliability, as well as ease in maintenance and rep air ability.

To explain a further preferable embodiment of the invention, it is noted that the abovementioned treadmill vehicle, which is known from

NL1039126C, has its electromotor 11 directly coupled to the front wheel 12 of the treadmill vehicle, see Fig. 1 of NL1039126C. Furthermore, it is noted, that also for a treadmill vehicle according to the present invention the electromotor may be directly coupled to a vehicle wheel, which is a front wheel of the treadmill vehicle. In fact, according to the present invention the electromotor may be directly coupled to any one of the at least two vehicle wheels of the treadmill vehicle, which includes any one of the at least one treadmill-coupled wheel of said at least two vehicle wheels. Hence, according to the present invention the electromotor may for example also be directly coupled to a vehicle wheel, which is a back wheel of the treadmill vehicle.

In a further preferable embodiment of the invention, said electromotor is directly coupled to one of said two return-pulleys, said one of said two return -pulleys thus being a driven return-pulley. Such an application of such a direct coupling of the electromotor to said driven return-pulley provides a more direct driving of the moving belt, as compared to the abovementioned treadmill vehicle known from NL1039126C, which has its electromotor directly coupled to its front wheel. This more direct driving of the moving belt provides a safer, as well as a more comfortable walking experience for the user.

It is remarked that said direct coupling of the electromotor to said driven return-pulley may also be applied, with similar advantages, to a treadmill vehicle according to the preamble of the appended independent claim 1, wherein the treadmill vehicle does not necessarily have the features of the characterizing portion of the appended independent claim 1. In other words, said similar advantages are obtained for a treadmill vehicle, comprising:

- a vehicle frame;

- at least two vehicle wheels arranged and configured for movement of the treadmill vehicle over a ground;

- a treadmill, which comprises an endless moving belt, which is passed over two return-pulleys having mutually parallel return-pulley axes, and which is arranged and configured for a user of the treadmill vehicle to walk in a forward walking direction on the endless moving belt in a treadmill fashion, while at the same time the treadmill vehicle is performing said movement over the ground in a forward driving direction being the same as the forward walking direction, wherein said walking direction is defining a backside and a frontside of the treadmill in the sense that said walking direction is directed from said backside towards said frontside;

- a force transmission mechanism arranged and configured for force transmission between the endless moving belt of the treadmill and at least one treadmill-coupled vehicle wheel of said at least two vehicle wheels; and

- an electromotor arranged and configured for driving said movement of the treadmill vehicle over the ground;

characterized in that said electromotor is directly coupled to one of said two return-pulleys, said one of said two return-pulleys thus being a driven return-pulley.

The abovementioned aspects and other aspects of the invention will be apparent from and elucidated with reference to the embodiment described hereinafter by way of non-limiting example only and with reference to the schematic figures in the enclosed drawing.

Fig. 1 shows, in side view, an example of an embodiment of a treadmill vehicle according to the invention. Fig. 2 separately shows, in the same side view as Fig. 1, the endless moving belt of the treadmill of the treadmill vehicle of Fig. 1, wherein the abovementioned hingeable supporting frame is situated in- between the abovementioned upper and lower trajectories of the moving belt, and wherein the supporting frame is in a first hinge position relative to the vehicle frame, and wherein said first hinge position corresponds to a normal operation condition of the treadmill vehicle in the sense that a user is safely walking on the moving belt.

Fig. 3 shows the situation of Fig. 2 again, however, with the difference that in Fig. 3 the supporting frame is in a second hinge position relative to the vehicle frame, wherein said second hinge position

corresponds to the abovementioned abnormal operation condition of the treadmill vehicle in which a user is unsafely walking on the moving belt or in which there is no user on the moving belt.

Fig. 4 shows the hingeable supporting frame of Figs. 2 and 3 in a perspective view.

Fig. 5 shows the hingeable supporting frame of Figs. 2-4 in front view.

Fig. 6 shows, in a highly schematical manner, the

abovementioned electromotor, abnormality sensor and control circuitry of the treadmill vehicle of Fig. 1, as well as an electrical power source and a rotation sensor, and together with a number of communicative connections between these parts of Fig. 6.

The reference signs used in the abovementioned Figs. 1-6 are referring to the abovementioned parts and aspects of the invention, as well as to related parts and aspects, in the following manner.

1 treadmill vehicle

2 vehicle frame

3 vehicle wheel, treadmill-coupled vehicle wheel 4 vehicle wheel

5 treadmill

6 endless moving belt

7 return-pulley, driven return-pulley

8 return-pulley

9 forward walking direction

10 forward driving direction

11 backside of the treadmill

12 frontside of the treadmill

14 force transmission mechanism

15 electromotor

16 abnormality sensor

17 control circuitry

18 rotation sensor

19 first chain-wheel

20 chain

21 second chain-wheel

22, 23 two identical gears forming a gear train

24 abnormality sensor magnet

25 rotation sensor magnets

26 upper trajectory of the endless moving belt

27 lower trajectory of the endless moving belt

28 supporting structure

30 supporting frame

31 hinge axis

32 supporting rollers

37, 38 return-pulley axes

39, 40 at least one spring

41 movement direction of endless moving belt 42 electrical power source Based on Figs. 1-6, and with the aid of the above-recited meanings of the reference signs, the abovementioned aspects of the invention will already be clear for the greater part. Below is a further elucidation in the light of the specific example shown in Figs. 1-6.

Now, reference is first made to Fig. 1. The treadmill vehicle 1 of Fig. 1 is a two-wheel vehicle, wherein the vehicle wheel 4 is the frontwheel and the vehicle wheel 3 is the backwheel. The endless moving belt 6 of the treadmill 5 of the vehicle 1 is passed over the two return -pulleys 7 and 8. It is seen that return -pulley 7 is on the backside 11 of the treadmill 5 and that return-pulley 8 is on the frontside 12 of the treadmill 5.

As indicated above, the backwheel 3 also is a treadmill-coupled vehicle wheel. That is, the force transmission mechanism 14 provides force transmission between the backwheel 3 and the endless moving belt 6 of the treadmill 5.

In the shown example, the force transmission mechanism 14 is realized as follows. A chain 20 is passed over a first chain-wheel 19 and a second chain-wheel 21. The first chain-wheel 19 is co-axially attached to the return-pulley 7. The second chain-wheel 21 is co-axially attached to a gear 22, which forms a gear train with an identical gear 23, which is co-axially attached to the hub of the backwheel 3.

It is noted that the gear train formed by the two identical gears 22, 23 serves the purpose to reverse the rotation direction within the force transmission mechanism 14. The reason for this reversal of the rotation direction is that in a normal operation condition of the treadmill vehicle 1, the vehicle 1 is moving in the forward driving direction 10, which is the same direction as the forward walking direction 9 of a user walking on the moving belt 6. Since said forward walking direction 9 corresponds to a movement direction of the moving belt 6, indicated by the arrows 41 in Fig. 1, it is clear that the vehicle wheels 3 and 4 are rotating in clockwise direction, as seen in Fig. 1, while the return -pulleys 7 and 8 are rotating in anti-clockwise direction, as seen in Fig. 1. Accordingly, the backwheel 3 has a rotation direction which is opposite to that of the return -pulley 7. This explains why the force transmission mechanism 14 has been designed so as to reverse the rotation direction.

In Fig. 1 the reference numeral 15 is used to indicate that the electromotor 15 of the vehicle 1 is directly coupled to the return-pulley 7, which therefore is a driven return -pulley.

It is noted that, in the shown example, the force transmission mechanism 14 is provided with an automatical out-of-gear mechanism, which means that, if the treadmill 5 is not driven by the electromotor 15 and/or by a user walking on the moving belt 6, the vehicle can roll over a ground in the forward driving direction 10, while at the same time the moving belt 6 remains in standstill condition.

In Fig. 1 it is furthermore seen that rotation sensor magnets 25 are attached to the second chain-wheel 21 in circumferential direction of the second chain-wheel 21. Furthermore, alongside the second chain-wheel 21, there is a rotation sensor 18 attached to the vehicle frame 2. Responsive to sensing whether the rotation sensor magnets 25 are rotating or not, the rotation sensor 18 determines whether the second chain-wheel 21 is rotating or not. Depending on whether this determination is affirmative or not, the rotation sensor 18 enables or disables, respectively, the operation of the electromotor 15 by actuating a first circuit breaker in the electric power supply circuit of the electromotor 15.

In order to explain how the treadmill vehicle 1 is started up, it is now assumed that initially the treadmill vehicle 1 is in a standstill position on a ground, while a user is standing on the ground alongside the vehicle 1, and while the user is holding the vehicle's handlebar in his or her hands. In this situation, the abovementioned first circuit breaker is in turned-off condition meaning that the operation of the electromotor 15 is disabled. Next, the user walks alongside the vehicle, while at the same time the user is pushing the vehicle a bit in the forward driving direction 10. At some point in time during this walking-and-pushing the user can step onto the moving belt 6. On or shortly after stepping onto the moving belt 6, the user is supposed to initiate walking on the moving belt 6 in the forward walking direction 9. This initiation of walking means that the moving belt 6 will start to move in the movement direction indicated by the arrows 41 in Fig. 1. This also means that the rotation sensor magnets 25 start to rotate, which leads to the rotation sensor 18 switching the abovementioned first circuit breaker into turned-on condition, which normally will start-up the electromotor 15 to drive the driven return-pulley 7. Thereby, the

electromotor 15 simultaneously drives the moving belt 6 of the treadmill 5 in the direction 41, and, via the force transmission mechanism 14 and the backwheel 3, the treadmill vehicle 1 in the forward driving direction 10.

The user can now enjoy his or her journey, in which the user can walk in a very natural and relaxed manner, while at the same time being comfortably ridden. Generally, in view of the presence of the electromotor 15 and in view of the fact that the force transmission mechanism 14 generally has a certain transmission ratio, the travelling speed of the vehicle 1 relative to the ground considerably exceeds the walking speed of the user relative to the upper trajectory 26 of the endless moving belt 6. It is noted that the treadmill vehicle 1 may optionally be provided with adjustment means for adjusting the transmission ratio of the force transmission mechanism 14.

Furthermore it is noted that, depending on the angle of ascending slope of the moving belt 6 in the forward walking direction 9, the user in fact supplies his or her walking energy for the benefit of driving the treadmill vehicle 1 in the forward driving direction 10 over the ground. It is noted that the treadmill vehicle 1 may optionally be provided with adjustment means for adjusting the inclination of the moving belt 6 in the forward walking direction 9.

Next, additional reference is made to Fig. 2-5. These figures show the supporting structure 28, which comprises the supporting frame 30, which is hingeable relative to the vehicle frame 2 about the hinge axis 31. Figs. 2-5 also illustrate that said hingeability is resilient in view of the two springs 39 and 40, which are mounted between the vehicle frame 2 and the supporting frame 30. Figs. 2-5 furthermore illustrate that the supporting structure 28 further comprises the supporting rollers 32, which are attached to the supporting frame 30 in a bearing-mounted manner, and which are arranged side by side, mutually parallel, and parallel to the two return- pulley axes 37 and 38, and which are further arranged so as to rollingly support the endless moving belt 6 in its upper trajectory 26 from below during operation of the treadmill vehicle 1.

Fig. 2-5 furthermore illustrate that the abnormality sensor magnet 24 is attached to the frontside of the hingeable supporting frame 30, while the abnormality sensor 16 is attached to the vehicle frame 2.

Responsive to sensing whether the abnormality sensor magnet 24 is in line with the abnormality sensor 16 or not, the abnormality sensor 16

determines whether there is an abnormal operation condition of the treadmill vehicle or not. Depending on whether this determination is affirmative or not, the abnormality sensor 16 disables or enables,

respectively, the operation of the electromotor 15 by actuating a second circuit breaker in the electric power supply circuit of the electromotor 15.

As mentioned, Fig. 2 shows the first hinge position of the supporting frame 30 relative to the vehicle frame 2, wherein this first hinge position corresponds to a normal operation condition of the treadmill vehicle 1 in the sense that a user is safely walking on the moving belt 6. In Fig. 2 it is the body mass of the user that keeps the supporting frame 30 in the first hinge position. In Fig. 2 it is seen that in this first hinge position the abnormality sensor magnet 24 is in line with the abnormality sensor 16. Furthermore, as mentioned, Fig. 3 shows the second hinge position of the supporting frame 30 relative to the vehicle frame 2, wherein this second hinge position corresponds to the abovementioned abnormal operation condition of the treadmill vehicle 1 in which a user is unsafely walking on the moving belt 6 or in which there is no user on the moving belt 6. In Fig. 3 it is seen that in this second hinge position the abnormality sensor magnet 24 is not in line with the abnormality sensor 16.

Accordingly, when during normal operation condition of the treadmill vehicle 1, the user would inadvertently leave the moving belt 6 and step onto the ground, the supporting frame 30 will hinge from the first hinge position of Fig. 2 into the second hinge position of Fig. 3, due to the fact that the user's body mass is not present on the moving belt anymore. As a result, the abnormality sensor 16 disables the operation of the

electromotor 15 by actuating the second circuit breaker in the electric power supply circuit of the electromotor 15.

Similar things happen when during normal operation condition of the treadmill vehicle 1, the user would inadvertently walk too close to the backside 11 of the treadmill 5. Also in that case the supporting frame 30 will hinge from the first hinge position of Fig. 2 into the second hinge position of Fig. 3, this time due to the fact that the user's body mass is transfered more to the backside 11.

Reference is now made to the highly schematical Fig. 6, which shows the electromotor 15, the abnormality sensor 16, the control circuitry 17, and the rotation sensor 18, together with an electrical power source 42 (battery), and together with a number of straight lines, which schematically represent (wired or partly wireless) communicative connections between these parts of Fig. 6. The abovementioned first and second circuit breakers for enabling/disabling the operation of the electromotor 15 may for example be embedded into the control circuitry 17. While the invention has been described and illustrated in detail in the foregoing description and in the drawing figures, such description and illustration are to be considered exemplary and/or illustrative and not restrictive; the invention is not limited to the disclosed embodiment.

For example, the shown treadmill vehicle 1 has two vehicle wheels, i.e. one backwheel 3 and one frontwheel 4. Instead, a treadmill vehicle according to the invention may of course have more than two vehicle wheels, such as two backwheels (e.g. arranged parallel and side by side) instead of one backwheel and/or two frontwheels (e.g. arranged parallel and side by side) instead of one frontwheel.

Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims.

In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. Furthermore, a single other unit may fulfill the functions of several items recited in the claims. Any reference signs in the claims should not be construed as limiting the scope.