WO2014070008A2

WO2014070008A2 - Rocking device for rocking a pushchair, wheel and pushchair provided therewith and method therefor

Info

Publication number: WO2014070008A2
Application number: PCT/NL2013/050775
Authority: WO
Inventors: Anand Kumar BADAL
Original assignee: Badal Beheer B.V.
Priority date: 2012-10-31
Filing date: 2013-10-30
Publication date: 2014-05-08
Also published as: WO2014070008A3; NL2009735C2

Abstract

The invention relates to a rocking device for rocking a pushchair, wheel and pushchair provided therewith and method therefor. The rocking device comprises a housing provided with a drive; a part drivable by the drive and rotatable relative to the housing; engaging means for allowing the rotatable part to engage on a wheel of the pushchair such that the rotation axis of the rotatable part is substantially coaxial with the rotation axis of the wheel; and mounting means connected to the housing for mounting the housing on the frame of the pushchair such that the housing is situated on the outward facing side of the wheel.

Description

ROCKING DEVICE FOR ROCKING A PUSHCHAIR, WHEEL AND PUSHCHAIR PROVIDED THEREWITH AND METHOD THEREFOR

The invention relates to a rocking device. The invention relates more particularly to an automatic rocking device suitable for use in combination with a pushchair.

Pushchairs are known in practice. When it is desirable for babies to sleep or at least rest herein it has been found useful in practice to rock the pushchair. This requires for instance a parent always having to be in the vicinity, making this parent less effectively able, or even wholly unable, to engage at that moment in other activities and/or pursuits. The continuous presence of the parent is moreover detrimental to the child learning to sleep independently.

An object of the invention is to obviate or in any case reduce the above stated problem.

This object is achieved with the rocking device according to the invention for rocking a pushchair comprising a frame and wheels, the rocking device comprising:

a housing provided with a drive;

- a part drivable by the drive and rotatable relative to the housing;

engaging means for allowing the rotatable part to engage on a wheel of the pushchair such that the rotation axis of the rotatable part is substantially coaxial with the rotation axis of the wheel; and

mounting means connected to the housing for mounting the housing on the frame of the pushchair such that the housing is situated on the outward facing side of the wheel.

Using the engaging means the rotatable part can engage on a wheel of the pushchair, after which the rotatable part, and thereby the wheel, can be driven using the drive. A rocking movement can hereby be automatically performed without physical effort on the part of the parent. The drive is preferably configured to allow the wheel to perform a reciprocal movement. The drive is alternatively configured as auxiliary drive to move the pushchair forward or to support this movement. It is also possible according to the invention to configure the drive such that it can be switched between a position in which a rocking movement is performed and a position in which a movement with a constant direction is performed.

An additional advantage of the rocking device according to the invention is that it can engage on the outward facing side of the wheel of a pushchair, i.e. the rocking device is configured such that it can be placed on the outer side of the wheel. This results in a simple mounting. The outer side of the wheel is understood to mean the outer of the two substantially flat sides of the wheel, so not the running surface of the wheel. The outer wheel surface is that surface facing away from the pushchair. The device can thus be placed as a kind of hub cap or attachment on this outer surface of the wheel. The wheel of the pushchair need not therefore be disassembled. Nor does the existing wheel axle of the pushchair need to be modified in order to arrange the rocking device on the pushchair. This enables a simple mounting of the rocking device according to the invention. A further advantage of the fact that the housing is situated on the outer side of the pushchair is that the space between the wheels is kept clear, whereby a storage space for instance remains available.

A further advantage of the rocking device according to the invention is that it is universally applicable. Because the rocking device can engage on the outer wheel surface of the pushchair, the rocking device is dependent to a lesser extent on the embodiment of the pushchair. This is because the outer sides of the wheels of the pushchair are generally accessible.

The drive is wholly or partially provided on the housing, for instance wholly or partially in, on, close to or operatively connected to the housing.

A further advantage of the rocking device according to the invention is that a compact embodiment becomes possible wherein no components which could form a safety hazard protrude. For this purpose the drive is preferably accommodated for at least the greater part in the housing.

In a preferred embodiment the engaging means are configured for co-action with spokes of the wheel of the pushchair.

When a pushchair has spokes the rocking device according to the invention can be mounted in simple manner by means of the engaging means.

It is noted that the invention can also be applied to pushchairs with wheels which do not have spokes. A hole is for instance made through the wheel of the pushchair to which the engaging means are coupled by means of a bolt and nut or screw.

In a further preferred embodiment the engaging means comprise two discs connectable to each other for the purpose of clamping the discs against either side of the wheel.

This further enhances the universal application of the pushchair. Different types of pushchair generally have a different arrangement of the spokes of the wheel. By providing discs which can be clamped against the side surfaces of the wheel, and at least one of which is connectable to the rotating part, the rocking device can be applied to substantially all pushchairs. The at least one disc is preferably connectable to and disconnectable from the rotating part.

The discs for instance comprise one or more openings for passage of a bolt and nut through these openings, wherein the bolt is carried between the spokes of the wheel. By providing these openings at suitable locations the discs can be placed on wheels of different types of pushchair. The openings are for instance provided as slots so that the bolt can be positioned at the suitable location. In a preferred embodiment the engaging means comprise a first coupling part which is attachable to the outward facing side of the wheel and a second coupling part co-acting with the first coupling part during use and attached to the rotatable part.

The rotation of the rotatable part is transmitted to the wheel of a pushchair by the coupling between said coupling parts. The coupling parts can preferably be mutually engaging, for instance by means of a snap mechanism, mutually engaging protrusions and recesses or mutually engaging toothings. The first coupling part for instance comprises a recess with internal toothing and the second coupling part comprises a toothed wheel fitting into the recess, wherein the teeth of the toothed wheel co-act with the toothing of the first coupling part. A simple connection and disconnection of the rocking device to and from a wheel of a pushchair is hereby realized.

In a preferred embodiment the engaging means comprise a magnet.

The magnet enables a simple and firm coupling between the device and the wheel.

The magnet can be a permanent magnet or an electromagnet, wherein an electromagnet comprises a coil.

In a further preferred embodiment the mounting means comprise an arm connected to the housing.

The arm is preferably adjustable relative to the housing. The arm is for instance connected to the housing by means of a hinge and/or the arm is extendable. The adjustability of the arm allows universal mounting of the rocking device on pushchairs. Different pushchairs have differently embodied frames, wherein the distance to the wheel will for instance vary. This is compensated by adjusting the arm.

In a further preferred embodiment the mounting means comprise a pin-hole connection between the arm connected to the housing and a mounting part mountable on the frame. The mounting means for instance comprise a protrusion which is attachable to the frame and an opening in the arm connected to the housing, into which opening the protrusion fits, or the mounting means comprise a protrusion attached to the arm connected to the housing and an element attached to the frame with an opening into which the protrusion fits.

The device is easy to mount on the pushchair by inserting the protrusion into the opening. The protrusion can for instance be a pin. The protrusion or the element with the opening can for instance be attached to the frame by means of a clamp. The pin/the element with the opening can remain attached to the frame while the housing can be connected and disconnected.

In a further preferred embodiment the position of the pin of the pin-hole connection is adjustable relative to respectively the frame and/or the arm of the housing.

The angle formed by the protrusion relative to respectively the frame and/or the housing is for instance adjustable. This makes it possible to position respectively the protrusion and the element with the opening relatively imprecisely on the frame, while the housing of the rocking device can nevertheless be coupled to the frame.

In a further preferred embodiment an energy source for the drive is accommodated in the arm.

The energy source will generally comprise a battery. Such a battery takes up a great deal of space. Accommodating the energy source in the arm prevents the device being too large and heavy close to the wheel, whereby a better mounting of the device on a pushchair is realized.

The device for instance comprises a battery which is rechargeable during displacement of the pushchair, wherein use is for instance made of a dynamo.

It is noted that an external energy source is likewise possible according to the invention.

In a preferred embodiment the rocking device comprises an adjusting means for switching between a coupled position, in which the drive is coupled to the rotatable part, and an uncoupled position in which the drive is uncoupled from the rotatable part.

Providing an uncoupled position prevents the rocking device having a braking action on the pushchair when it is used normally, i.e. during the forward movement of the pushchair. The rocking device is coupled only when the pushchair has to be rocked. In the uncoupled position the rocking device according to the invention can remain mounted on the wheel, so avoiding the rocking device having to be continuously mounted and removed. It is in fact possible to suffice with a once -only mounting on the wheel of the pushchair, after which a switch is made from the uncoupled position to the coupled position (the rocking position) by means of the adjusting means.

In a preferred embodiment the rocking device comprises a worm wheel.

A compact embodiment is realized by applying a worm wheel, which for instance engages with a toothed wheel which forms the rotating part or is connected to the rotating part. The drive for instance comprises a motor which drives the worm wheel, after which the worm wheel drives a toothed wheel, and the toothed wheel is coupled to the engaging means for the purpose of transmitting the rotation to the wheel of the pushchair. A further advantage of the worm wheel is that it is a robust transmission.

It is noted that the coupled position also provides a safety measure for the pushchair. This is because the drive of the rocking device has a certain measure of braking action on the pushchair, so preventing it from moving unintentionally, for instance when standing on a slope. A braking action of the transmission is obtained particularly in combination with the worm wheel.

In a preferred embodiment the drive comprises a reduction gearbox. The rotation speed of the motor of the drive is reduced by the reduction gearbox, whereby the torque of the drive is increased. This makes it possible to apply a relatively small motor so that a compact and practical embodiment of the rocking device is realized. The rocking device according to the invention preferably comprises a controller connected to the drive for the purpose of controlling the speed and/or stroke of the rocking.

This results on the one hand in a universal application of the rocking device according to the invention. As described above, different types of pushchair are known which generally comprise wheels of a different size. The rotation speed and the number of rotations can be adjusted in both directions by means of the controller so that the size of the wheel can be taken into account. The controller on the other hand makes it possible to select different rocking settings, for instance a slow and a rapid setting. It is also possible to vary the stroke of the rocking movement. The stroke length is for instance 20-80 cm. A frequency of 0.1-4 vibrations per second has been found effective, preferably 0.1-1 vibration per second.

The settings can alternatively and/or additionally be chosen subject to the weight in the pushchair.

In a preferred embodiment the device comprises a remote control operatively connected to the drive. The drive can hereby be switched on and off remotely, the speed and/or stroke of the rocking can be set by means of the controller and/or the rocking device carried to the disconnected or connected position.

The remote control preferably comprises batteries and more preferably rechargeable batteries. The rocking device is additionally or alternatively provided with a switch for switching the rocking mechanism off and on.

The device preferably comprises a sensor configured to determine the distance between the remote control and the housing and a controller operatively connected to the sensor and configured to switch off the drive when the distance determined with the sensor exceeds a predetermined threshold value.

When a parent with remote control is a predetermined distance away from the pushchair on which the housing is mounted the controller then switches off the drive automatically, so guaranteeing a safe situation. The controller is for instance likewise configured to generate a signal, for instance in the form of a light or a sound.

The rocking device according to the invention preferably comprises communication means for communication between the controller and/or drive of the remote control. The communication means preferably comprise a radio signal, for instance Bluetooth, Zigbee or WiFi. The invention also relates to an application (app) for mobile devices such as smart phones or tablets for the purpose of wireless communication with the controller and/or drive. The above described functionality of the remote control can likewise be implemented in such an app, wherein the communication means of the rocking device are configured for wireless communication with the mobile device. The rocking device preferably comprises a sound sensor. The sound sensor is preferably configured to adjust settings, such as the speed and/or stroke of the rocking, to switch the drive on and off and/or to couple and uncouple the drive automatically on the basis of detected sound. The sound sensor is for instance operatively connected to a processing component which is set to detect the sound of a crying baby so that the rocking device can be switched on on the basis of this sound so as to thus calm the baby and send it to sleep. The sound sensor can alternatively or additionally be set to respond to voice commands.

A brake, spring and/or shock absorber is preferably provided which engages on the rocking mechanism such that a damping effect is produced on the movement at the end and/or beginning of the stroke. A jolting movement of the pushchair is hereby avoided.

The rocking device for instance further comprises a clamp or other movement-limiting element with which it is possible to prevent the rocking mechanism for instance displacing the pushchair over a certain distance.

The invention further relates to a wheel for mounting on a pushchair, wherein the wheel is provided with a rocking device as described above. The rocking device is preferably integrated with the wheel.

The invention further relates to a wheel for a pushchair with an integrated rocking mechanism. The rocking mechanism serves for reciprocal displacement of the wheel, and thereby the pushchair. The rocking mechanism is for instance integrated into the tyre of the wheel or on the wheel axle. Replacing a wheel of a pushchair with this wheel or providing this wheel on the pushchair as extra wheel enables rocking of the pushchair.

The rocking mechanism for instance comprises the rocking device as described above, with the difference that the housing is not situated on the outward facing side of the wheel but is integrated into the wheel. The above described features of the rocking device can likewise be applied according to the invention in the wheel according to the invention. The rocking mechanism for instance comprises a remote control or sound sensor.

In a preferred embodiment the rocking mechanism comprises a direct drive. This means that no gearboxes are provided for transmission of the rotation of a motor to the wheel. This makes a compact drive possible.

In a preferred embodiment the rocking mechanism comprises an electric motor with a rotor and a stator, wherein the stator is fixedly connected to an axle of the wheel and the rotor rotatable around the axle is fixedly connected to a hub of the wheel. The rotor and stator are integrated into the wheel.

In a further preferred embodiment the magnets or the electromagnets of the rotor are located further from the axle in radial direction than the magnets or electromagnets of the stator. The greater distance to the axle makes a larger magnet surface area possible. This increases the torque of the integrated drive. A relatively low number of revolutions are required for the rocking since it is not necessary to realize a high speed, while a sufficiently high torque, for instance 6-10 N/m, is advantageous for the purpose of setting a pushchair into motion. A further advantage is that a robust drive is obtained with relatively few components.

In an exemplary embodiment the electric motor is configured to also serve as generator, for instance for the purpose of charging a battery. When a pushchair with the wheel is moved manually, this movement can generate energy with the electric motor, which then serves as generator. This generated energy can be stored in a battery and later utilized to rock the pushchair.

The invention further relates to a pushchair provided with a rocking device as described above.

Finally, the invention relates to a method for mounting a rocking device as described above on a pushchair.

The same advantages and effects as described for the rocking device apply in respect of the wheel, the pushchair and the method according to the invention. The features of the rocking device, the wheel, the pushchair and the method can particularly be combined as desired.

Further advantages, features and details of the invention are elucidated on the basis of preferred embodiments thereof, wherein reference is made to the accompanying figures.

- Figure 1 shows a pushchair provided with a rocking device according to a first embodiment of the invention;

- figure 2 shows a detail of the rocking device of figure 1 ;

- figure 3 shows a view of a wheel of the pushchair with the rocking device of figures 1 and 2;

- figure 4 shows a partially cut-away view of the rocking device of figures 1-3;

- figure 5 shows a partially cut-away view of the coupling mechanism of the rocking device of figures 1-4;

- figure 6 shows the toothed wheel of the drive of the device of figures 1-5;

- figure 7 shows a pushchair provided with a rocking device according to a second embodiment of the invention;

- figure 8 shows the parts of the rocking device of figure 7 which are mounted on the pushchair;

- figure 9 shows in detail the mounting of the engaging means of the second embodiment on a wheel of the pushchair;

- figure 10 shows the coupling of the rocking device according to the second embodiment to the mounting means and engaging means arranged on the pushchair; - figure 11 shows the side of the rocking device according to the second embodiment facing toward the wheel of the pushchair;

- figure 12 shows details of the drive on the inner side of the rocking device according to the second embodiment;

- figure 13 shows in detail the planetary gear system of the drive of figure 12;

- figure 14 shows a partial cross-section of a wheel with integrated drive according to the invention;

- figure 15 shows a side view of a cross-section of the wheel according to figure 14;

- figure 16 shows further details of the wheel according to figures 14 and 15; and

- figures 17 and 18 show the stator and rotor of the wheel according to figures 14-16 individually.

Pushchair 2 comprises a number of wheels 4a, 4b and a frame 6. Wheel 4a is provided with rocking device 8 which comprises a handle 10 for attaching to frame 6 of pushchair 2. Handle 10 is connected by means of a hinge 12 to housing 14 (figure 1).

Rocking device 8 further comprises a knob 18 (figure 2) for connecting or disconnecting the drive to or from wheel 4a, which will be further elucidated below.

Arm 10 is provided with a mounting means 20 for mounting the arm on frame 6. This mounting means 20 can pivot around arm 10 so that recess 21 can be placed round a component of frame 6. A bar of frame 6 is for instance placed in recess 21. Arm 10 is attached to frame 6 by subsequently closing mounting means 20.

Wheel 4a comprises a wheel axle 22 (figure 3) which is shown only partially in the figure. Wheel 4a is provided with spokes 24 onto which two discs 26a, 26b of rocking device 8 are clamped using screws 28.

Accommodated in housing 30 (figure 4) is an encoder 32 which is connected to motor 34. The encoder measures the speed of motor 34, wherein a controller (not shown) controls the speed and direction of motor 34 on the basis of the rotation speed measured by encoder 32 and other considerations. Motor 34 is connected to drive shaft 36 which is provided with a worm wheel 38. Worm wheel 38 engages on toothed wheel 40.

Toothed wheel 40 can rotate relative to housing parts 42 and 44 (figure 5). These housing parts 42, 44 are connected by means of screws 46. Knob 18 is connected to a shaft 48. Toothed wheel 40 rotates around this shaft, wherein ball bearings 50 are provided.

Balls 52 are provided which can form a connection between toothed wheel 40, shaft 48 and part 56. In the shown situation, in which knob 18 is pulled out, toothed wheel 40 can however rotate around shaft 48 without part 56 co-rotating here. Shaft 48 comprises a narrowed portion 54 whereby, when knob 18 is pulled out, balls 52 lie close to the shaft so that toothed wheel 40 is uncoupled from part 56. Knob 18 is held in the coupled position by means of spring 58. Knob 18 is therefore pulled out counter to the spring force of spring 58. Knob 18 is rotated as it is pulled out so that pin 60 is moved out of housing part 42. Knob 18 is rotated so that pin 60 is situated on part 42 and the rocking device remains disconnected.

Coupling of toothed wheel 40 to wheel 4a now takes place by rotating knob 18 so that pin

60 drops into housing 42, whereby balls 52 move outward so that part 56 is coupled via shaft 48 to toothed wheel 40.

Balls 52 move outward here through openings 62 (figure 6) of the shaft of the toothed wheel so that they lie in grooves 64 provided between protrusions 66.

The mounting of the rocking device according to the invention is illustrated with reference to figures 1 and 3. Discs 26a, 26b are first mounted on the wheel by placing screws 28. The discs are clamped firmly against the sides of spokes 24 by tightening the screws. Discs 26a, 26b generally comprise more holes than are necessary for mounting on the wheel so that the discs can be applied on multiple types of wheel.

Device 8 is then coupled to the discs. Arm 10 is subsequently adjusted using hinge 12 and coupled to frame 6 using mounting means 20.

The user now couples the drive to the wheel by pushing in knob 18. The motor is switched on, after which a rocking movement is transmitted to the wheel.

The described steps can be performed in any suitable sequence.

Pushchair 102 (figure 7) comprises a number of wheels, including front wheel 104, and a frame 106. A rocking device 108 according to a second embodiment of the invention is placed on front wheel 104. Rocking device 108 comprises an arm 110 for coupling to frame 106 of pushchair

102. Arm 110 is connected by means of a hinge 112 to housing 114.

Rocking device 108 can be mounted on pushchair 102 using a mounting means 116 (figure 8) attached to frame 106 of pushchair 102. In the shown embodiment mounting means 116 is attached to a bar of frame 106 by means of a clamping connection. Mounting means 116 also comprises an adjustable pin 118 in addition to the clamp.

A disc 126a mounted on the outer side of wheel 104 serves as engaging means. Disc 126a comprises internal toothing 127. Disc 126a is mounted against the wheel by being coupled to an annular disc 126b on the other side of the wheel. Screws 128 attach discs 126a and 126b to each other, wherein screws 128 extend between spokes 124 of wheel 104. Disc 126a is provided with magnets 129.

Arm 110 of device 108 comprises an opening 111 close to its free outer end (figure 10). Pin 118 of mounting means 116 fits into opening 111. Opening 111 is placed over pin 118 as according to arrow I. This holds rocking device 108 in place. The lower part of pin 118 comprises a ball accommodated in a housing of mounting means 116 so that the angle formed by pin 118 relative to frame 106 is adjustable. In other words, pin 118 is provided on a ball joint. In order to couple rocking device 108 to wheel 104 housing 114 is placed against disc 126a as according to arrow II. Toothed wheel 162 (figure 11) of device 108 then engages in internal toothing 127 of disc 126a. In the shown embodiment toothed wheel 162 tapers to some extent and the corresponding opening in disc 126a with toothing 127 also tapers to some extent, as seen in the direction from device 108 toward wheel 104. This realizes a good engagement of toothed wheel 162 and toothing 127 of disc 126a. Magnets 129 of disc 126a co-act with a ferromagnetic ring 163 of rocking device 108. Ring 163 comprises for instance iron and/or nickel, or an alloy thereof. The magnetic coupling realizes a good and simple coupling of device 108 to wheel 104. Alternatively, disc 126a comprises a ferromagnetic material and rocking device 108 is provided with a magnet in a zone close to toothed wheel 162, or both disc 126a and rocking device 108 are provided with magnets.

Housing 114 comprises two housing parts 114a and 114b (figure 12). Toothed wheel 162 is provided on the outer side of housing part 114b. Toothed wheel 162 is rotatable relative to housing 114. Toothed wheel 162 is driven by motor 134 (figures 12 and 13). Via first toothed wheel 164 motor 134 drives a larger toothed wheel 166 so that it rotates around shaft 168. Also mounted on shaft 168 is a star-shaped part 170 which forms part of a planetary gear system. In the shown embodiment the star shape comprises three arms. The star shape is situated in cylindrical sleeve 172 which is provided with internal toothing. Star-shaped part 170 comprises a central toothed wheel which engages with each of the toothed wheels on the outer ends of the star shape.

Sleeve 172 comprises recesses 174 for receiving protrusions 176 of housing part 114b. In the mounted position sleeve 172 cannot therefore rotate relative to housing 114b. It is noted that sleeve 172 is not connected to the large toothed wheel 166. Housing part 114b comprises an inner part with protrusions 178 and shaft 180, which part can rotate relative to housing part 114b. In the mounted position shaft 180 is located in opening 182 of star-shaped part 170.

Star-shaped part 170 rotates with toothed wheel 166 because part 170 is connected via shaft 168 to toothed wheel 166. The toothed wheels on the outer ends of star-shaped part 170 run here over the inward directed toothing of sleeve 172. The planetary gear mechanism provides among other things for a centering so that jolts and vibrations in the rocking movement are prevented. It is noted that the shown transmission with the planetary gear mechanism is optional.

Wheel 204 (figure 14) according to the invention comprises an integrated drive. Wheel 204 can replace a wheel of a pushchair or be mounted as extra wheel so that the pushchair can be rocked back and forth using wheel 204. Wheel 204 comprises an axle 222. Wheel 204 for instance comprises a pneumatic tyre 284. Arranged around axle 222 are magnets 286 (figure 15) which form part of the rotor. The magnets are fixedly connected to tyre 284 via the spokes and hub 294 for rotation of tyre 284 around the axle through rotation of the magnets around the axle.

The rotor comprises a bridge part 298 which is fixedly connected to the magnets and inner rotor part 299. Provided between inner rotor part 299 and the magnets is stator 288 which comprises coils 292. In the shown embodiment stator 288 moreover comprises a soft iron, although this is optional. Stator 288 is fixedly connected to axle 222. A bearing 290 is provided between inner rotor part 299 and axle 222 (figure 16).

Figures 17 and 18 show the rotor and stator as separate components. Also shown is an attachment 296 which connects the stator to the axle.

A force is exerted on magnets 286 by means of an alternating current through coils 292 so that the rotor begins to rotate around axle 222. Since the rotor is connected to tyre 284, tyre 284 will begin to rotate around axle 222.

The invention is by no means limited to the above described preferred embodiments thereof. The rights sought are defined by the following claims, within the scope of which many modifications can be envisaged.

Claims

1. Rocking device for rocking a pushchair comprising a frame and wheels, comprising:

a housing provided with a drive;

- a part drivable by the drive and rotatable relative to the housing;

2. Rocking device as claimed in claim 1 , wherein the engaging means are configured for co-action with spokes of the wheel of the pushchair.

3. Rocking device as claimed in claim 1 or 2, wherein the engaging means comprise two discs connectable to each other for the purpose of clamping the discs against either side of the wheel.

4. Rocking device as claimed in claim 1, 2 or 3, the engaging means comprising a first coupling part which is attachable to the outward facing side of the wheel and a second coupling part co-acting with the first coupling part during use and attached to the rotatable part.

5. Rocking device as claimed in any of the foregoing claims, wherein the engaging means comprise a magnet or electromagnet.

6. Rocking device as claimed in any of the foregoing claims, wherein the mounting means comprise an arm which is connected to the housing and which is adjustable relative to the housing.

7. Rocking device as claimed in claim 6, the mounting means comprising a pin-hole connection between the arm connected to the housing and a mounting part mountable on the frame.

8. Rocking device as claimed in claim 7, wherein the position of the pin of the pin-hole connection is adjustable relative to respectively the frame and/or the arm of the housing.

9. Rocking device as claimed in any of the foregoing claims, wherein the mounting means comprise an arm which is connected to the housing and in which an energy source for the drive is accommodated.

10. Rocking device as claimed in any of the foregoing claims, further comprising an adjusting means for switching between a coupled position, in which the drive is coupled to the rotatable part, and an uncoupled position in which the drive is uncoupled from the rotatable part.

11. Rocking device as claimed in any of the foregoing claims, wherein the drive comprises a worm wheel.

12. Rocking device as claimed in any of the foregoing claims, wherein the drive comprises a reduction gearbox.

13. Rocking device as claimed in any of the foregoing claims, comprising a controller connected to the drive for the purpose of controlling the speed and/or stroke of the rocking.

14. Rocking device as claimed in any of the foregoing claims, comprising a remote control operatively connected to the drive, a sensor configured to determine the distance between the remote control and the housing and a controller operatively connected to the sensor and configured to switch off the drive when the distance determined with the sensor exceeds a predetermined threshold value.

15. Rocking device as claimed in any of the foregoing claims, comprising a sound sensor.

16. Wheel for a pushchair, comprising a rocking mechanism integrated into the wheel.

17. Wheel as claimed in claim 16, the rocking mechanism comprising a direct drive.

18. Wheel as claimed in claim 16 or 17, the rocking mechanism comprising an electric motor with a rotor and a stator, wherein the stator is fixedly connected to an axle of the wheel and the rotor rotatable around the axle is fixedly connected to a hub of the wheel.

19. Wheel as claimed in claim 16, 17 or 18, wherein the magnets or the electromagnets of the rotor are located further from the axle in radial direction than the magnets or electromagnets of the stator.

20. Pushchair provided with a rocking device or wheel as claimed in any of the foregoing claims.

21. Method for mounting a rocking device or wheel as claimed in any of the foregoing claims on a pushchair.