WO2009155919A1

WO2009155919A1 - A wireless control unit

Info

Publication number: WO2009155919A1
Application number: PCT/DK2009/000148
Authority: WO
Inventors: Henning Kristensen
Original assignee: Linak A/S
Priority date: 2008-06-25
Filing date: 2009-06-23
Publication date: 2009-12-30
Also published as: DE212009000086U1

Abstract

A wireless control unit (1) for an actuator system, comprising a cabinet (3, 4) and having at least one operating key (2), whereby the individual key (A), when operated, performs an adjustment function in the actuator system, a wireless radio-based transmitter (B, C, D) and a power supply (E) in the form of a battery, said battery being mounted in the cabinet (3, 4) without any possibility of exchanging it, since, following assembly, the cabinet can¬ not be opened again. The battery (E) is selected so as to be able to provide the wireless control unit with energy during the entire service life of the actuator system. Communications between the control unit and a receiver take place according to a proprietary protocol.

Description

A wireless control unit

The invention relates to a wireless control unit for the adjustment of an actuator system as defined in the introductory portion of claim 1.

More particularly, the invention relates to wireless control units for actuator systems incorporated in articles of furniture. As an example of an adjustable bed, reference may be made to WO 2005/122841 A1 to Linak A/S, which concerns an actuator system for beds for domestic use. WO 2007/112755 A1 to Linak A/S discloses a corresponding actuator system, which is primarily intended for nursing beds, while EP 488 552 B1 discloses an actuator system for a hospital bed. Another example of the use of an actuator system is disclosed in WO 2007/054092 A1 to Linak A/S, where it is incorporated in a patient lifter. Finally, actuator systems are also used in height adjustable tables, cf. e.g. WO 2004/040169 A1 to Linak A/S.

A wireless control unit provides a greater comfort in connection with the operation, as the irritation involved by cables is avoided completely. What is in mind here is especially that cables tend to get entangled or are restrictive relative to the user's freedom of movement. The task of cleaning the structure also becomes less difficult with a wireless control unit, since the cables are not in the way. Cables are also likely to get jammed between the movable parts in the structure which the actuator system adjusts. Wireless control units, however, are not without problems. Who has not experienced the situation that a wireless control unit does not operate, typically because of problems with the batteries? It may well be that the batteries have to be exchanged, because they have been depleted of energy. Further, it may also well be that the control unit has been dropped on the floor, whereby the batteries have been knocked out of their holder. Here, there is the risk that, subsequently, the batteries are mounted wrongly. Repeated drops of the control unit on the floor may have as a result that the control unit fails periodically. Typically, the failures occur because the connection to the batteries becomes unreliable.

The object of the invention is to provide a solution to the problem outlined above, viz. to be able to construct a wireless control unit for an actuator system which has means for avoiding drainage of the battery and additionally maintains the connection to the battery, even if the control unit is subjected to knocks or blows. At the same time, it is desired that the control unit is small and compact.

This is achieved according to the invention by constructing the wireless control unit as stated in claim 1 , where the battery cannot be exchanged.

That the battery is mounted firmly and securely on a print board, on which the rest of the electronics of the control unit are also mounted, means that the unit has a greater resistance to knocks and blows. The battery may be equipped with solder terminals for direct soldering of the battery on the print board, or the print board may be provided with a holding unit for the battery which holds the battery securely in its position. With such a structure, the unit is less expensive to produce than a unit having an exchangeable battery, since the wiring to the battery has been rendered superfluous. That the battery is not intended to be exchangeable also makes the mechanical structure of the cabinet less complicated and costly, since there is no need for a separate space in the cabinet for the battery and a door which may be opened when the battery is to be exchanged.

That there is no possibility of exchanging the battery makes demands on the energy content of the battery and the self-discharge of the battery relative to the expected service life of the actuator system. This means that the service life of the battery, both in running time combined with dwell time, must exceed the corresponding running time and dwell time of the actuator system.

Therefore, it order to be able to meet these requirements, it is also necessary for the electronics of the wireless control unit to have a low operating current and quiescent current to avoid discharge of the battery or to avoid the necessity of having an unduly physically large battery.

To avoid draining the battery of the control unit unintentionally, as might happen during transport or if a control unit gets jammed in an unfortunate manner, a timer is incorporated in the system which, when a key is depressed persistently, stops the function and causes the control unit to enter into a power-saving mode in which the transmitter is not active. When the key is released, the function may then be activated again.

It is ensured hereby that the service life of the battery thus exceeds the service life of the actuator system under all circumstances. This means that the cabinet, after having been assembled around the components of the control unit, need not be opened again. Expediently, the parts of the cabinet will be provided with cooperating snap locking means which hold the two parts together after the assembly. As the cabinet is not intended to be separated again, since the intention is that the battery does not need exchange, the snap locking means may be constructed such that they cannot be released from the mutual engagement after the assembly, without the cabinet or the snap locking means being destroyed and being incapable of being assembled again. Other advantageous ways of assembling the parts of the cabinet are by welding or gluing. Combinations of these, such as e.g. gluing and snap locking means will be practical, since the snap locking means keep the two parts in their correct position until the glue has hardened. The shown embodiment and manner of assembly will impart a smooth and solid finish to the cabinet of the control unit. With the selection of electronics and battery, it is possible to manufacture a very compact control unit, which even has a very low weight.

Communications between the wireless control unit and the wireless re- ceiver take place via defined commands laid down in a protocol. The command from the wireless control unit is designed such that identification of the transmitter is disclosed, and then the desired processing in the form of data. As far as the wireless receiver is concerned, this may be arranged to receive data, more or less selectively, from a wireless control unit. De- signed flexibly, the wireless receiver may be configured via software to be operated from all, a single or a range of wireless control units on the basis of the ID of the wireless control unit. In practice, the configuration of the wireless receiver may take place via training sequences, where the wireless control units, which are to be connected, are operated during a training pe- riod. In this manner, it will be possible for the wireless receiver to catch the unique ID of a wireless unit, which is to be connected, and store this ID internally for subsequent approval of connected units. This also means that any defective control unit may be replaced by another in an easy manner.

As will be seen, the invention provides a solution to the outlined problem which satisfies the demands made. The wireless unit is simple in that the energy supply for the unit during the entire service life thereof is incorporated in the unit in the form of a battery, which never has to be exchanged and is therefore arranged in the cabinet inaccessible for exchange. This results in a less expensive structure, as a battery box and wiring to it may be eliminated. Also, the cabinet may be constructed in a more simple and less expensive manner. When the battery is mounted, preferably in a holder on a print board containing all electronics and connections to a keyboard, the battery is simultaneously protected against falling out of the unit, thus eliminating any possibility of wrong mounting. A wireless control unit for the adjustment of an actuator system according to the invention will be described more fully below with reference to the accompanying drawings, in which:

fig. 1 shows a cabinet for a wireless control unit,

fig. 2 shows a block diagram of the electric circuits in the wireless control unit,

fig. 3 shows a print board for a wireless control unit mounted with components,

fig. 4 shows a base part in the cabinet for a wireless control unit,

fig. 5 shows a top part in the cabinet for a wireless control unit, and

fig. 6 shows a diagram of the communications between a wireless interface and a wireless unit.

Fig. 1 of the drawing shows the cabinet for a wireless unit 1. As will be seen, the cabinet is constructed in a simple manner, there being only the keys 2 necessary for the operation of the actuator system. The cabinet is shown from the upper side 3, but the lower side 4, which is only shown in part, is even more simple in that it has an unbroken face, as there is no door for the exchange of the battery.

Fig. 2 shows a block diagram of the structure of the wireless control unit 1 , which will be explained here. Block A is formed by the keyboard with underlying contacts for the keys 2, whereby a function in the actuator system may be activated. It might e.g. be a function which raises or lowers a leg- rest or backrest section of a bed. The input of the keyboard is passed on to block B, which is a microcontroller. The microcontroller used here is of the type AT Tinyl13 and, in the present structure, is particularly characteristic in having a very low standby current of below one microampere. When a key 2 is activated, the microcontroller switches to an active mode, in which it generates a train of pulses on an output which corresponds to the selected function according to the communications protocol.

The communications protocol will be described more fully with reference to fig. 6. The key 2 is kept depressed while the function is performed. If, unintentionally, the key 2 is activated persistently, e.g. during transport or in that the wireless control unit 1 gets jammed in the bed, the microcontroller has programmed in it a timer which, following expiry, causes the microcontroller to enter into the standby mode, in which the consumption of energy is minimized. During this mode, the microcontroller will check at regular intervals whether the key has been deactivated again. Block C contains the PA stage (Power Amplifier) for the RF transmitter, and, in all simplicity, consists of a transistor and a crystal and a pair of capacitors. The signal from the microcontroller is thereby modulated by the PA stage. The capacitors, together with the antenna in block D, constitute an oscillation circuit. The antenna constitutes a coil having one winding made in the form of a loop antenna constructed as a print path on the print board. When the output on the microcontroller is kept low, the PA stage will be turned off, so that no energy is drawn from the battery. The holding device of the battery is designated block E in fig. 2. The battery is of the type Sony CR2032 Lithium Magnesium. The battery is unique in that it has a self-discharge time at 25 degrees of 100 years. Without being activated, the wireless control unit has a standby power consumption of one microampere, as mentioned earlier. This means that the battery will be able to supply the wireless control unit with energy without operation for 25 years. The service life of an actuator system may roughly be assumed to be 5000 cycles, but, of course, the parts age like everything else, even when it is not used. The most age-affected parts are plastics parts and lubricants. When a key is activated for the operation of the actuator system, the wireless transmitter transmits, whereby a transmission current of 3.3 mA runs in the circuit. Since the train of pulses is modulated and has no fixed duty cycle on either packets or individual bits, the effective transmission current during transmission is 0.5 mA. If the transmission period, which corresponds to one cycle in the actuator system, is assumed to be one minute, even though this time is considerably shorter in modern actuator systems, a system service life which is more than twenty years is achieved. In practice, measurements on the concrete circuit have shown that the standby current is lower than one microampere, and, therefore, an even longer service life can be expected. A system service life of twenty years or more must be considered to be satisfactory, which is the reason why the wireless control unit according to the invention may be constructed such that the battery is not exchangeable.

This structure results in great savings of mechanics and a simpler configuration, since all the electronic parts, including the battery, may be disposed on the print board 5, which, following mounting, is arranged in a cabinet 3, 4. Fig. 3 shows a sketch of the print board 5, which illustrates the contact points for the operating keys A, the microcontroller B, the RF PA part C, the antenna D and the holding device E of the battery.

In this embodiment, the holding device E for the battery is mounted directly on the print board 5 and is provided with large solder terminals 6, which ensure a good connection and also mechanically provides a good joint, even if the wireless unit 1 should be dropped. When the battery of the type

Sony CR2032 is mounted in the holding device E and the print board 5 is mounted in the cabinet 3, 4, the cabinet ensures that the battery cannot work itself out of the holding device E. Other embodiments are possible, such as e.g. a battery provided with solder terminals soldered directly on terminals provided on the print board 5.

The cabinet 3, 4, as shown in figs. 4 and 5, is particularly adapted to contain the print board 5 in that it receives and secures the print board 5 in special guides 7 provided on the base part 4 with corresponding matching bowls 8 provided in the top part 3. The guides 7 extend through holes 12 in the print board and are fixed in the bowls 8. As shown in fig. 4, the base part 4 of the cabinet is provided with support devices in the form of upstanding flanges 9, which particularly support the keys of the keyboard, so that the deflection of the print board 5 is minimized. The two parts of the cabinet, the base part 4 and the top part 3, are equipped with snap locking means 10, 11 , which quickly and easily keep the cabinet in the assembled form around the print board 5. This ensures a quick and efficient production flow in connection with the manufacture of the wireless control unit 1. The unit is also protected effectively against falling apart, even if it should be subjected to knocks or blows, e.g., by being dropped on the floor. When the snap locking means 10, 11 are in mutual engagement, the cabinet may expediently be constructed in such a manner that the cabinet cannot be opened without destroying the snap locking means 10, 11 or the cabinet 3, 4 completely or partly, precisely for the reason that no service is required or is possible to perform on the wireless control unit 1 during its service life.

The communication is RF-based and proceeds according to the specifications in a protocol, which is explained in fig. 6, from which it will be seen that three trains of pulses are transmitted from a control unit with a pause of one millisecond between the trains of pulses. A new series of trains of pulses may be transmitted at an interval of one hundred and sixty milliseconds. In principle, a train of pulses consists of a unique identification code for the control unit followed by data which essentially consist of instructions for the control on which function to activate. This means that an activation of a key will have as a result that pulses are continuously transmitted to the control, which will then continuously perform the desired function, until the key is no longer activated, or the position of the spindle nut in the linear actuator has been run to an end position. As an additional safeguard, a check sum calculation at several levels has been introduced into the proto- col, thus both in connection with the unique identifier and data. The train of pulses also consists of a preamble and a header, which indicate the start of a new train of pulses and also has the wireless interface synchronized to receive the train of pulses. The counter is incremented for each train of pulses which is transmitted by the type concerned. If the type is changed, the counter is reset. The field Type describes the type and the length of the data field, so that the wireless interface is capable of separating this variable data field from the train of pulses.

As will appear from the icons on the keys 2, the control unit shown in fig. 1 is intended for use in connection with actuator systems for adjustable beds. It will be appreciated that the invention may also be used in connection with actuator systems for armchairs or recliners and for height adjustable tables, also called sit/stand tables.

Claims

PATENT CLAIMS

1. A wireless control unit (1) for the control of an actuator system, comprising: a cabinet (3, 4) provided with at least on operating key (2), whereby the individual key, when operated, performs an adjustment function of the actuator system, a wireless radio-based transmitter (B, C, D), and a power supply in the form of a battery (E), charact erized in that the battery (E) cannot be exchanged.

2. A wireless control unit according to claim ^characterized in that the battery (E) is dimensioned with respect to energy content such that it can supply the wireless control unit (1) with energy for the service life of the associated actuator system.

3. A wireless control unit according to claim ^characterized in that the electronics of the wireless control unit are arranged such that a persis- tent depression of a key (2), which exceeds a programmed period of time, will stop the function and enter into a power-saving mode in which the transmitter is not active.

4. A wireless control unit according to claim 1, characterized in that the cabinet is composed of at least two parts (3, 4) which, with cooperating snap locking means (10, 11), keep the two parts together.

5. A wireless control unit according to claim 4, characterized in that when the cabinet (3, 4) has been assembled and the cooperating snap locking means (10, 11) are in engagement, the cabinet cannot be opened again, without the cabinet (3, 4) and the snap locking means (10, 11) being damaged.

6. A wireless control unit according to claim 4, characterized in that the cabinet (3, 4) is adapted to receive (7, 8), support (9) and secure (10, 11) a print board (5) having a keyboard (A), electronics (B, C, D) and a battery (E) for the wireless control unit.

7. A wireless control unit according to claim 6, characterized in that the cabinet (3, 4), when this is mounted around the print board (5), me- chanically prevents the battery from sliding out of a holding device (E) for the battery.

8. A wireless control unit according to claim ^characterized in that the electronics (B, C, D) of the wireless control unit (1) are arranged such that the control unit is in an active mode when an operating key (2) is activated, and such that the control unit is in an inactive mode when the keys (2) are not activated.

9. A wireless control unit according to claim 1, characterized in that the wireless control unit (1) communicates via the wireless radio-based transmitter with a wireless receiver on the basis of standards laid down in a common proprietary protocol for communication between the units.

10. A wireless control unit according to claims 1 to 9, characterized in that the service life of an actuator system, calculated in the form of both wear in use and ageing of materials, forms a framework for a required energy content of a battery for a wireless control unit (1), such that the functional service life of the control unit is always longer than the service life of the actuator system.