Each drive type is designed to deal with an individual load capacity which defines the maximum pull or push force (with linear actuators and double drives) from the drive.
The load capacity is always a so-called dynamic load - even under this maximum load, the drive carries out a reliable adjustment movement. The load capacity is stated as a force (in the case of linear actuators) in newtons [N].
Lever mechanisms which match specific applications and convert the drive movement to the required adjustment.
The maximum load which a double drive can support does not only depend on the constructional aspects which are described via the adjustment load. In particular, the actual usable load depends on the electrical - and therefore on the mechanical - output of the drive which is available. The "push forces" value indicates which maximum load distributed over both drive sides can be handled by the double drive. Primarily it depends on the efficiency of the electronic components which are used (e.g. transformers).
Two adjustment drives and all control functions are fitted into a single casing. OKIMAT double drives represent the most cost-effective solution for the individual adjustment of head ends and foot/knee ends or height adjustment in motorised beds, slatted beds or beds. Thanks to their "all-inclusive" design, double drives can be fitted in next to no time. If additional adjustment functions are needed, more single drives can be connected to OKIMAT drives.
This defines the basic length which is required for each drive. In the case of the double drive, the fitting dimension represents the distance between the axles of the fittings for the head end and foot end. In the case of single drives, depending on the design, there are different methods of determining the fitting dimension. However, the most common definition is that of the distance between the fastening or support points (e.g. clevis drill holes, etc.).
In the case of a linear actuator, the fitting dimension can be determined either in the completely retracted or extended state. Important technical drive characteristics such as the drive type, adjustment load, stroke, etc. have a direct influence on the fitting dimension.
This technical factor defines the maximum period of time during which a drive can be operated without interruption. A pre-set currentless time must also be maintained following operation. Both time values are shown as a ratio which indicates the intermittent duty data (ID). A factor of 10% is now standard in the furniture sector - this means that a 2-minute period of uninterrupted operation must be followed by a break of 18 minutes or max. 5 switching cycles per minute. Of course, in the event of operation for a shorter period of time, the break can be correspondingly shorter. It is vital for the operator to follow the instructions regarding intermittent duty, otherwise possible overloading might result in the activation of the protective devices.
Universal drive unit for almost all applications. Single drives are available in an extremely wide range of designs and offer maximum flexibility and functions for dealing with individual adjustment situations. The choice of a suitable drive depends on the type of drive movement which is required (rotation actuator, linear actuator) and on the performance data required for each specific application. Single drives are available as complete ready-for-use main drives (with an integrated control unit or a control unit which is mounted on the drive) and as especially compact slaves.
A technically perfect final switch-off process is vital for the safe operation of a drive system. Two basic systems are used for furniture drive systems:
• Limit switches:
The current to the motor is interrupted via electromechanical limit switches, which stops the drive working.
• Electronic (virtual) limit switches:
In many cases restrictions on space in the application mean that it is not possible to fit electromechanical limit switches. In this case, memory drives with a position feedback system are used. The control unit recognises the relevant end positions and stops the drive.
With this device, the user can operate all the functions of drives and slaves. Pressing a key generates switch signals which are converted into the corresponding control signals in the control unit.
• Cable handset (standard):
The handset is connected directly to the control system via a connection cable; the switch signals are transmitted by wire.
• Infrared (IR):
In place of the standard handset, an infrared receiver is connected to the control unit's interface. The switch signals sent from the IR remote control unit are picked up by the receiver and transferred to the control unit. There must always be visual contact between the IR transmitter and the receiver, because data transfer takes place via light signals in the infrared range.
• Radio frequency (RF):
In place of the standard handset, an infrared receiver is connected to the control unit's interface. The switch signals sent from the RF remote control unit are picked up by the receiver and transferred to the control unit. The range of the RF-transmitter is between 10 and 15 m, visual contact is not necessary as the radio waves are not disturbed by walls.
This drive, with its integrated control, or with a drive-mounted control unit, can be connected directly to the power supply unit. A transformer converts the mains voltage to a safe 24 V DC, and the drive movements are activated reliably via the integrated control unit. Depending on the drive concept, the transformer can be integrated or alternatively fitted in an external power supply unit. Depending on the type, additional slaves can be connected to the main drive control unit.
For linear actuators, the maximum adjustment path is described as the "stroke".
The lifting column is a single drive with a robust linear guidance which is often equipped with special design features. This type of drive is able to deal reliably with lateral forces and bending moments and also to guarantee the necessary stability when fully extended. In many cases, more than one synchronously-controlled lifting column is used in a single application.
This type of drive is fitted with a system for recognising positions and paths. Information on the current drive position and/or speed is continuously transferred to a control unit which is suitably equipped. An incremental position feedback system (Hall sensor) is available for almost every OKIN drive.
The memory drive is used for applications in which stored comfort positions need to be called up at the press of a button. They are also necessary in applications which involve complicated movements and with synchronous adjustment movements.
The OKIN mains isolation separates the control to the line voltage completely when the actuator is not in use.
Only when the handset is actually being operated, the actuator will be connected to the line voltage. If no actuator is running, no electricity is being allowed to pass the mains isolation plug, which in turn prevents any electrical or magnetic field in or around the actuator.
An integrated primary fuse (optional) separates the bed’s plug from the mains in critical cases.
This permits the emergency operation of a drive system in the event of a power failure. Depending on the type, the drive is supplied with power from either one or two 9-volt batteries.
As a result of the extremely reduced capacity of the sources of power, the drive movement is restricted to a single emergency operation. In particular, please note that in many cases it is not possible to carry out a drive movement under load.
The batteries can have a transportation lock. In this case they must be connected before initial operation.
This is a high-quality transformer in which the primary and secondary coil are fitted together on a ring-shaped core (toroid). This special arrangement means that the magnetic fields are bundled almost entirely inside the transformer's core and are not exposed. This effect reduces noise fields and stand-by power consumption to a minimum, as in the case of a mains cut-off. These positive characteristics ensure that this type of transformer represents the technical standard.
The tightness of an item of electrical equipment against penetration by solid and liquid materials is classified using the two-digit IP code in accordance with EN 60 529. The first digit defines protection against penetration by solid materials such as dust; the second digit defines protection against liquids. Standard protection categories include IP 20 (protection against accidental contact), IP 44 (splash or weatherproof protection) and IP 66 (hoseproofness).
As only insulating plastic casings are used, OKIN main drives and control units are made exclusively in protection classification II. The two-core mains cable does not have protective earthing.
This is an additional nut which travels parallel to the spindle nut. If a fault occurs, the safety spindle nut takes over the supporting function of the spindle nut, so preventing an uncontrolled collapse of the drive. Depending on the drive type, a safety spindle nut is effective with push and pull loads.
In numerous applications, drive and control systems with a direct mains connection were replaced by external power supplies. Supply to the application is with a protective low voltage; there is no direct connection to the mains power supply. Depending on the technical concept of the drive system, the power supply is with DC or AC.
The control unit incorporates various functions for operating the drives and, if fitted, optional additional equipment (e.g. massage, heating, etc.) The switch signals from a handset are converted to control functions for the connected drives. At the same time, depending on the model, the control unit incorporates equipment for the voltage supply (rectification, smoothing, transformer) as well as various protection elements to secure against overloads and short circuits.
The integrated evaluation of position feedback systems by hall sensors permits the connection of memory drives and, consequently, the setting of stored comfort positions at the press of a button.
Even when the loads vary considerably, several drives can be operated synchronously at the same speed.
This technology is often used when a single adjustment movement is achieved with more than one drive (Office).
This is a technical device for recording the current drive position and speed.
In all cases, a distinction is made between incremental and absolute processes.
• Hall sensor (incremental):
For each distance travelled, the position feedback system generates a specified number of electrical pulses. From this the control calculates, in relation to a fixed reference point, the current information about position and velocity. For a reliable functioning of the system this reference point must be available correctly at any time. If the data on the reference point are lost in the unlikely event of a mains power failure or a malfunction, re-referencing will have to be carried out.
This is an especially compact drive type which must be operated in connection with a main drive or a control unit. Connection is by means of plug-in motor cables.
The adjustment movements of the connected drives are coordinated and monitored via control software which is designed to match the applications. Applications are sophisticated situations in which complex sequences of movement need to be coordinated.
(control without relay)
With this control concept, the drive currents are switched directly via the handset (for use in especially low-cost drive solutions). Here, so-called X or Y cables are often used. With certain drive types, this functionality can also be integrated directly into the drive casing. If the relay-free control is used, it is particularly important to ensure that suitable handset models are selected (Seating).
The handset activates electromechanical relays which, in turn, switch the drive currents (the most widely-used control technology). There are almost no restrictions as regards the selection of handsets and operating equipment (Bedding).
Note: Responsibility for OKIN products when used for specific applications and for adherence to the appropriate guidelines, standards and laws is borne by the manufacturer of the complete system into which OKIN products are fitted. We accept no liability for the correctness.