Abstract
Drive system (2) for a spring cradle system (100), in particular for a child's or baby's spring cradle, for generating an oscillating movement, comprising a tension element (4) with a distal end adapted to be fixed to an oscillating element, a drive unit (21) adapted to increase and decrease a free length of the tension element (4) to change a position of the oscillating element relative to the drive system (2), and a control unit (22) adapted to control the drive unit (21) so that a pretensioning force acts on the tension element (4) regardless of the position of the oscillating element relative to the drive system (2). Further provided is a spring cradle system (100) comprising the drive system and a method for simulating an elastic clamping element.
Claims
1. A drive system for a spring cradle system that generates an oscillating movement, the drive system comprising: a tension element having a distal end adapted to be fixed to an oscillating element, wherein the tension element is a band-like element, a drive unit configured to increase and decrease a free length of the tension element to change a position of the oscillating element relative to the drive system, wherein the drive unit comprises a rotatable shaft configured to rotate causing the tension element to roll up over the rotatable shaft, and a control unit configured to control the drive unit such that a pretensioning force acts on the tension element regardless of the position of the oscillating element relative to the drive system, wherein the pretensioning force is a tensile force for maintaining the tension of the tension element.
2. The drive system of claim 1, further comprising at least one sensor for determining a displacement of the distal end of the tension element, wherein the at least one sensor is a contactless sensor.
3. The drive system of claim 1, wherein the drive unit is configured to apply a variable force to the tension element.
4. The drive system of claim 1, wherein the drive system (2) comprises an energy storage device configured to supply the drive unit (21) and the control unit (22) with energy.
5. The drive system of claim 1, wherein the pretensioning force is less than 15% of the maximum power of the drive unit.
6. The drive system of claim 1, wherein the control unit is further configured to control the drive unit such that the oscillating element performs a predetermined oscillating movement.
7. The drive system of claim 1, wherein the drive system comprises at least one resettable element connecting the drive system to the oscillating element.
8. The drive system 7 of claim 1, wherein the control unit is configured to detect properties of the resettable element and to control the drive unit based thereon.
9. The drive system of claim 1, wherein the drive system comprises a recuperation device configured to recover energy from the oscillatory motion of the oscillating element.
10. The drive system of claim 1, wherein the tension element is provided on the drive system so as to extend away from a central point of the drive unit.
11. The drive system of claim 1, wherein the drive system further comprises an electronic shutdown device, wherein the control unit is configured to periodically send operating signals to the shutdown device, and wherein the shutdown device is switched off to automatically cut off the power supply to the drive unit when it is not receiving operating signals.
12. A spring cradle system comprising: an oscillating element for receiving at least one person; and a drive system arranged in a fixed position, the drive system comprising: a tension element having a distal end fastened to the oscillating element, wherein the tension element is a band-like element, a drive unit configured to increase and decrease a free length of the tension element to change a position of the oscillating element relative to the drive system, wherein the drive unit comprises a rotatable shaft configured to rotate causing the tension element to roll up over the rotatable shaft, and a control unit configured to control the drive unit such that a pretensioning force acts on the tension element regardless of the position of the oscillating element relative to the drive system, wherein the pretensioning force is a tensile force for maintaining the tension of the tension element.
13. The spring cradle system of claim 12, further comprising at least one sensor configured to detect a state of the at least one person accommodated in the oscillating element, wherein the control unit is configured to control the drive unit based on the detected state and/or to output the state of the at least one person to an output unit.
14. A method for simulating an elastic clamping element, comprising the following steps: a) providing a drive system comprising a tension element having a distal end adapted to be fixed to an oscillating element, and a drive unit adapted to increase and/or decrease a free length of the tension element to change a position of the oscillating element relative to the drive system, wherein the drive unit comprises a rotatable shaft over which the tension element is configured to be rolled up by rotation of the rotatable shaft, b) operating the drive unit so that a pretension is applied to the tension element to simulate an elastic clamping element, c) determining that the distal end of the tension element does not move toward the drive unit, and d) finishing the simulation of the elastic clamping element, wherein the pretensioning force is a tensile force for maintaining the tension of the tension element, and wherein the tension element is a band-like element.
15. The method of claim 14, wherein the method further comprises the steps of: e) operating the drive unit to initiate an oscillating motion of the oscillating element such that the distal end of the tension element moves away from the drive unit, f) determining that the distal end of the tension element no longer moves away from the drive unit, and g) operating the drive unit so that the preload is applied to the tension element to simulate an elastic tension element.
Description
[0094] In the following, embodiments of the present invention are described in detail with reference to the accompanying drawings. Thereby shows
[0095] FIG. 1 a schematic representation of a drive system according to one embodiment of the present invention in use with a spring cradle system,
[0096] FIG. 2 a schematic representation of a drive system according to a further embodiment of the present invention in use with a spring cradle system,
[0097] FIG. 3 a schematic representation of a drive system according to a further embodiment of the present invention in use with a spring cradle system,
[0098] FIG. 4 a schematic representation of a drive system according to a further embodiment of the present invention in use with a spring cradle system,
[0099] FIG. 5 a schematic representation of a drive system according to a further embodiment of the present invention in use with a spring cradle system,
[0100] FIG. 6 a schematic representation of a drive system according to a further embodiment of the present invention in use with a spring cradle system,
[0101] FIG. 7 a schematic representation of a drive system according to a further embodiment of the present invention in use with a spring cradle system, and
[0102] FIG. 8 a schematic representation of a spring cradle system according to one embodiment of the present invention.
[0103] FIG. 1 is a schematic representation of a spring cradle system 100. The spring cradle system comprises a drive system 2 according to a further embodiment of the present invention. In the present embodiment, the spring cradle system 100 can be suspended in a stationary manner by means of a fixation 1. For example, the spring cradle system 100 can be suspended from a hook on a ceiling, a door frame and/or a rack. The drive system 2 is connected to the fixation 1 such that the drive system 2 hangs below the fixation 1 in the operating state. The spring cradle system 100 further comprises a tension element 4 and a resettable element 3. In the embodiment shown in FIG. 1, the resettable element is a spring. In another embodiment not shown, the resettable element is an elastic element comprising a stretchable material (such as rubber or elastomer) and is capable of elastically varying its length. The tension element and the elastic element 3 are both fixed to the drive system 2 so that they hang below the drive system 2 in the operating state. Attached to the tension element 4 and the elastic element 3 is a suspension element 5, which serves as part of the oscillating element. On the suspension element 5, in turn, a stretcher or cradle 6 is arranged (for example, suspended), in which a person (for example, a baby, child) can be seated. Thus, the stretcher 6 and the suspension element 5 together form the oscillating element.
[0104] The tension element 4 can be shortened by a drive unit 21 (see FIG. 2) accommodated in the drive system 2 so that a distance between the oscillating element and the drive system 2 is reduced. In the present embodiment, the tension element is rolled and unrolled on a roller 7 (not shown in FIG. 1) to vary the distance between the drive system 2 and the oscillating element. By subsequently releasing the tension element 4, the oscillating element can again move away from the drive system 2 due to the force of gravity. In this case, the tension element 4 does not exert any force on the oscillating element. The elastic element 3 deforms elastically, slowing down the movement of the oscillating element to a standstill. Subsequently, the elastic element 3 exerts a force on the oscillating element opposite to the previous movement, so that the oscillating element moves back towards the drive system 2 in a return movement. During the backward movement, the tension element 4 does not exert any force on the oscillating element. Thus, an oscillation of the oscillating element can be initiated.
[0105] In order to be able to maintain the oscillation by periodically tightening the tension element 4, the tension element 4 must always be kept under tension. In other words, the tension element 4 should not sag, so that direct tightening of the oscillating element is possible by rolling up the tension element 4. In the prior art, a tensioned tension element is provided by a mechanical clamping element. In this case, the mechanical clamping element is usually a spiral spring on a shaft of the drive unit 21. In the present invention, this mechanical clamping element is simulated by selectively operating the drive unit 21. Thus, a free length of the tension element 4 is shortened during an upward movement of the oscillating element (i.e., during a movement toward the drive system 2) such that the tension element is always tensioned between the drive system and the oscillating element. This ensures that the movement of the oscillating element can be acted upon directly when the drive unit is operated. In this way, even complex oscillation patterns can be realized by selective operation of the drive unit 21. In the same way, a harmonic oscillation that is maintained constant, for example, can also be provided.
[0106] FIG. 2 is a schematic representation of the spring cradle system 100 according to a further embodiment of the present invention. In contrast to FIG. 1, in FIG. 2 a housing 9 of the drive system is cut away so that the elements shown in the drive system 2 are visible. For example, the roller 7, which can be rotationally driven by the drive unit 21 and around which the tension element 4 can be wound and unwound, is shown. Furthermore, in the present embodiment, a motion sensor 8 is arranged in the housing 9 of the drive system. The motion sensor 8 is designed to detect a movement of the tension element 4. In doing so, the motion sensor 8 can detect a movement amount and a movement direction. Thus, a control unit 22, which is also arranged in the drive system, can conclude the position of the oscillating element relative to the drive system 2. Consequently, the drive unit 21 can be controlled with high precision to realize predetermined oscillation patterns on the one hand and to keep the tension element 4 under tension at all times on the other hand. In the present embodiment, the tension element 4 is guided by the sensor 8. For example, the sensor can be provided with two measuring rollers between which the tension element is clamped. The rotation of these measuring rollers enables the sensor to detect a movement of the tension element 4.
[0107] FIG. 3 is a schematic representation of the spring cradle system 100 according to another embodiment of the present invention. The embodiment shown in FIG. 3 corresponds to the embodiment shown in FIG. 2, except that the motion sensor 8 in the present embodiment is a non-mechanical sensor. In other words, the sensor 8 may be an optical sensor or an electromagnetic sensor. Therefore, an operation of the drive system 2 may be particularly quiet and low in closure. In this regard, the sensor 8 may, for example, be directed to a pole wheel 12 mounted to the shaft of the drive unit 21. The pole wheel 12 may have regular recesses that can be detected by the sensor 8. Further, the pole wheel may have magnetized elements that can be sensed by the sensor 8. In this case, the sensor 8 may be a Hall sensor.
[0108] FIG. 4 is a schematic representation of the spring cradle system 100 according to a further embodiment of the present invention. Here, the present embodiment comprises additional or alternative sensors 14 to the sensors of the above embodiments for recording information of a person accommodated in the stretcher. For example, the sensors 14 may comprise a vibration sensor. This can be used to detect movement of the person in the stretcher 6. In particular, due to the connection between the drive system 2 and the oscillating system being kept under tension by the tension element 4, movements of the person in the stretcher 6 can be transmitted to the drive system 2. Thereupon, the control unit 22 can adjust the operation of the drive unit 21 to the detected vibrations. If, for example, vibration is detected by sensors 14 in response to an unsteady behavior of a child picked up in the stretcher 6, the oscillation intensity can be increased or, conversely, decreased. This is based on the assumption, observed in practice, that children fall asleep more easily when the oscillation amplitude is higher. Furthermore, if restless behavior of the person is detected by the sensors 14, a notification can be sent to a smartphone, for example as a push notification.
[0109] FIG. 5 is a schematic representation of the spring cradle system 100 according to a further embodiment of the present invention. The present embodiment differs from the preceding embodiments in that no elastic element is provided here, but the oscillating element is connected to the drive system 2 only by means of a tension element 4. Furthermore, the drive system 2 has a roller 15 with a guide 16 for the tension element 4. In other words, the tension element 4 is specifically wound onto the roller 15 by the guide 16. Thus, a constant force can always be applied from the roller 15 to the tension element 4 and vice versa. As in the above embodiments, the roller 15 is driven by a drive unit (not shown in FIG. 5). Furthermore, a recuperation device 18 is provided in the drive system 2 and connected to the shaft on which the roller 15 is arranged. Thus, when the oscillating element moves away from the drive system 2 (i.e., driven by the gravitational force of the earth), energy can be recovered from the motion of the oscillating system. Furthermore, a motion sensor 8 in the form of a dynamo is connected to the shaft. Thus, the position of the oscillating element relative to the drive system can be reliably determined. In addition, this embodiment has a mechanical locking element 17 that is configured to hold the tension element 4 when, for example, no movement of the oscillating element is desired.
[0110] FIG. 6 is a schematic representation of the spring cradle system 100 according to a further embodiment of the present invention. This embodiment corresponds to the embodiments shown in FIGS. 2 to 4, with the difference that the motion sensor is directed directly at the tension element 4 and can register a movement of the tension element 4. In this case, the sensor is an ultrasonic sensor. Like the optical sensors mentioned above, this non-mechanical sensor has the advantage that an operation of the drive system 2 is very quiet and has low wear.
[0111] FIG. 7 is a schematic representation of the spring cradle system 100 according to a further embodiment of the present invention. This embodiment corresponds to the embodiments shown in FIGS. 2 to 4 and 6, with the difference that the motion sensor is configured as a dynamo located on the same shaft as the roller 7 and the drive unit 21. Consequently, movements of the roller 7 and thus of the tension element can be easily detected.
[0112] FIG. 8 is a schematic representation of a spring cradle system according to one embodiment of the present invention. Here, the tension element 4 is deflected by means of second deflection rollers so that the tension element 4 runs at an angle of about 45? relative to the horizontal from the drive system 2 to the suspension element 5. Furthermore, the stretcher 6 of the present embodiment has a tilt sensor. Thus, the control unit 22 can detect information about the position of the stretcher 6 and control the drive unit 21 based on this information. The deflection rollers are attached to a frame on which at least the oscillating element is suspended. Thus, an oscillating movement can be initiated by actuating the tension element 4.
LIST OF REFERENCE SIGNS
[0113] 1 Fixation [0114] 2 Drive system [0115] 3 Resettable element [0116] 4 Tension element [0117] 5 Suspension element [0118] 6 Stretcher [0119] 7 Roller [0120] 8 Motion sensor [0121] 9 Housing [0122] 12 Pole wheel [0123] 14 Vibration sensor [0124] 15 Roller with guided track [0125] 16 Guide for tension element [0126] 17 Mechanical lock [0127] 18 Recuperation device [0128] 21 Drive unit [0129] 22 Control unit [0130] 100 Spring cradle system
