PRIOR ART In order to utilise storage spaces effectively, displaceable shelf systems, so-called compact shelves or compact stores, are usually used, for example in offices, libraries, record offices and store rooms. An example of a truck comprising a shelf in just such a displaceable shelving system is shown in Fig. 1. In order to make it easier for a user to move the trucks in a compact store, the shelving system can also be motorised.

Drawbacks of currently found systems of motorised compact stores are, inter alia, that they are electrically powered with 220 V via cables for supplying power to the motor, in which the cables lie externally to the trucks in a variety of ways.

BRIEF SUMMARY OF THE INVENTION An object of the present invention is to provide a motorised compact store which does not have cables externally to the trucks of the compact store.

The present invention is based on the insight that the aforementioned object can be achieved by means of a compact store which, in each truck, comprises a motor and an electric accumulator for driving the motor.

The specific characteristics of a motorised compact store according to the present invention can be ascertained from patent claim 1.

An advantage with a motorised compact store configured according to the present invention is that the trucks in the compact store do not need connecting cables to supply power to the motors.

Further characteristics and advantages of the present invention will be ascertained from the following description and subsequent patent claims.

The invention will be described in greater detail below with reference to the detailed description of embodiments and the accompanying figures, which merely illustrate and thus do not limit the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows a truck in a compact store according to the prior art, and Figure 2 shows an exploded diagram of a motorised truck in a compact store according to the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS In the following description, specific details, such as particular techniques and applications, are given for explanatory and non-limiting purposes in order to achieve a thorough understanding of the present invention. It will be clear to a person skilled in the art, however, that the present invention can be realised in other embodiments which differ from these specific details. In other examples, a detailed description of well-known

methods and devices is omitted so as not to obscure the description of the present invention with unnecessary details.

A first embodiment of the present invention will now be described with reference to Fig. 2.

A compact store comprises a plurality of trucks 1 which, track-bound, are movable on a pair of rails 2. Each truck 1 comprises wheels for movement of the truck 1 on the rails 2, shelves or the like for stock-keeping, a motor 4, coupled to a drive shaft 8, for moving the truck 1 and a battery 5 for driving the motor 4. Since the current for driving the motor 4 comes from inside the truck 1, i. e. from the battery 5, no cabling is required outside the truck 1.

Activation of the motor 4 and hence movement of the truck 1 can be provided in a number of different ways.

Each truck 1 can have a handle with circuit breaker 3 for movement of the truck 1 to the left and right. The truck can transport itself under its own power, together with other trucks which need to be moved. Alternatively, the truck can send control signals to other trucks so that the truck located adjacent to an empty space to be filled moves first and, after this, one truck at a time is moved until the desired corridor is freed. Preferably, the signal traffic is sent by wireless transmission between the trucks, so that there is no need for wiring between the trucks, or else the signal traffic is sent via the rails and the wheels. The wireless connection can be realised, for example, via IR or radio.

A central panel can be present, which indicates the corridor which is required to be entered, i. e. the

shelves between which access is sought. In this case, too, a truck can receive an activation signal and hence required trucks can be moved under its own power, or alternatively one truck is moved at a time, refilling the respective empty space. Preferably, this signalling is also realised in a wireless manner. The central panel can be provided, for example, as a remote control.

A central controlling of the compact store can advantageously be combined with software, which, for example, in the event of a search hit in a register, automatically opens the right corridor for accessing the sought material according to any of the above-described methods for clearing corridors between shelves.

A system in which the motor in a truck is used to move a plurality of trucks at once has a greater inertia than a system in which each truck moves under its own power. The less inertia which is present in the system, the quicker the trucks can be stopped, which means that it is advantageous to use a system in which each truck moves under its own power.

A central panel can, of course, be combined with an activation member on each truck. The activation member on each truck can alternatively also comprise a panel for opening all the corridors, one corridor at a time.

The compact store is powered by low voltage, for example 12 V or 24 V, which is fed via the rails to the trucks. A transformer 7 is used to convert ordinary mains voltage into the low voltage which is applied to the rails. The current is received in the trucks, for example via the wheels or via a purpose-built collector shoe system for charging the batteries in the trucks. Drive power to the trucks is thereby obtained without the need for external

cables, since the low voltage is divided between the two rails.

Preferably, the battery in each truck is only charged when the truck is stationary. Uneven voltage levels and any sparking which might arise if the charging is carried out whilst the truck is in motion are thereby avoided. If the charge current varies, the drive current from the battery to the motor is also in danger of varying, which is not desirable. Each battery preferably has a control system which controls the charging. In addition, a central control system can be present, which, for example, only applies voltage to the rails when some battery is in need of charging.

Charging faults in a battery are indicated, for example, with a light-emitting diode on the respective truck, alternatively with a light-emitting diode on a central panel indicating the truck whose battery has a charging fault.

In order to achieve the above-described movement of the trucks automatically, break strips, for example, are provided on the trucks. A sensor is thereby provided, for example break contacts against the next truck 6, which indicates whether there is free space beside a truck, i. e. whether the shelves are accessible or not.

A second embodiment of the present invention will next be described, this too with reference to Fig. 2. This embodiment is identical with the first embodiment described above, apart from the following differences.

A compact store according to this second embodiment additionally comprises sensors for preventing jamming between shelves. Such a sensor interrupts the current to

the motor in the truck in which the sensor is situated.

In addition, an emergency stop signal can be sent to other trucks, so that the current to their respective motors is interrupted.

The above-described break strips can be used as sensors for jamming protection. Alternatively, the sensors for jamming protection can be provided in addition to the break strips, for example in the form of an optic detector or a mechanical contact breaker.

In case of automatic movement of the trucks, either one truck can move at a time, or else each truck which is to be moved can move as fast as the break strips and the jamming sensors allow. If a plurality of trucks are allowed to move simultaneously, an emergency stop, i. e. interruption of the motor current as the result of an emergency stop signal from a jamming sensor, should stop all moving trucks for safety reasons.

Preferably, a movement of a truck is activated with the aid of pulse control, i. e. a corridor is opened regardless of whether the circuit breaker is released or not, but is stopped if a jamming sensor emits an emergency stop signal.

It is clear that the present invention can be varied in a number of ways. Such variations should not be regarded as deviation from the scope of the present invention. All such variations which are obvious to a person skilled in the art are meant to be included within the scope of the present invention.