The use of mobile storage shelving which runs on rails has been common place in the art for some considerable time. The advantages of such systems are a saving of valuable space particularly in larger installations, where a number of"in line"storage racks are used. These systems are widely used in libraries particularly for archived records, they are also commonly used for the storage of medical records and legal documents to name just a few of many applications in the art.

Traditional installations use a hand-wheel, or crank lever fitted to each shelving bay which has to be hand cranked to move that particular bay.

Examples of such art may be found in US 1 142 447 and GB 2 360 071.

It either takes considerable strength to move a hand cranked system or considerable time because of the high gear ratios which are required to reduce the load presented to the operator. This makes these systems generally undesirable except for very low usage archived records and even then in today's health and safety aware arena, it is not advisable to use systems requiring physical activity on the part of the operator to move the shelving.

In today's business environment the use of mobile shelving is becoming increasingly popular and the applications are moving from archive systems to live storage in front of house locations such as law offices and building societies where appearance and ease of use are essential requirements.

In order to address these needs a number of motorised systems have entered into the art. An example of such a system is to be found in US 3 640 595 which describes a fully powered motorised rack storage system. This art is typical of the majority of systems around today in that it is complex, cannot easily be added to an existing manual system, is difficult to install and has either unsightly cables connecting the racking systems or as in the case of this particular art there is provided a complex reeling system for cables.

Generally the problem with the existing art is that a solution has not been taught which would remove the complex wiring and power supply provisions necessary to provide motive power. Also the need to ensure safety has required expensive insulation systems or heavy supply cables in the case of low voltage systems.

It is a first object of the present invention to provide a motorised mobile shelving system which does not need power supply cables running between the individual racks. It is a second object of the invention to provide said system in a form in which it may be used in converting existing manually driven systems.

According to the invention there is provided, a drive motor with means for connecting it to the running wheels, an electronic control circuit for controlling said motor, a means for permitting the user to initiate and/or control the start up and direction of the motor. Characterised by one or more voltage stabilisation and/or charging circuits either separate to, or part of the electronic control module, one or more batteries, one or more electric motors and contact means for receiving power to operate the charging circuit, either from and end stop or from another adjacent rack.

A second aspect of the invention provides for a combined contact system to operate as a means for receiving power and a means for transmitting power and which also may sometimes incorporate limit switches.

A third aspect of the invention provides a housing for all of the said first and second aspects of the invention which housing can be fitted to the outside face of a rack in place of a previously used manual operating hand wheel or lever.

The invention will now be more particularly described, by way of example, with reference to the accompanying drawings in which:- Figure 1 Shows a typical hand operated storage rack system with four racks a, b, c, and d, respectively, each individually driven by an operator turning hand wheel (1) and which runs on rails (2) Figure 2 Illustrates the rack system shown in figure 1 which has been converted to a motorised system by the addition of one means (3) of implementing the invention. The means, which are numbered 3a, 3b, 3c, and 3d, are identical units.

Figure 3 Is a diagrammatic representation of the electrical means used in a typical installation of three storage racks, a, b, and c, together with the connection means for transferring power from rack to rack. Also the end stops which supply power to the end racks are shown.

Figure 4 Shows a typical conversion module for hand operated systems which contains all of the essential elements of the invention including the combined limit switch and power contact means and which may or may not contain the motor.

Figure 5 Illustrates an end view of the unit described in figure 4 Figure 6 Shows the combined limit switch and power contact means shown as 15 in Figure 4, which unit can be turned upside down and reversed to become the means shown as 14 in Figure 4.

Referring to figure 1, A typical hand operated storage rack system is illustrated the four racks, a, b, c, and d, are equipped with wheels (not shown) which engage the rails 2. When the wheel is turned the rack travels along the rails. Therefore if wheel 1 is turned then the gap, 21, between rack a and rack b, either opens or closes depending on the direction of rotation of the wheel. In these systems there is often nothing to prevent the rack being closed together when a person is still standing between the racks.

Now referring to figure 2, the same rack system can be seen but the hand wheel has been replaced by units 3. Units 3a, 3b, 3c, and 3d are identical to each other. These units are fitted to an existing system in place of the hand wheel or any other manual drive means. The drive motor may or may not be included inside unit 3 depending on the type of drive used in the original construction of the rack. Also not shown, there is commonly, in this type of installation, a safety means to prevent the rack accidentally closing on a person standing between a moving rack and a stationary rack.

Such a device, known in the art, may consist of a touch surface or a photoelectric device or any other suitable means derived from already well known technology.

It will be understood that the invention is not restricted to the mounting of units 3 in the position shown in figure 2 these may be mounted higher, lower, in a position not visible to the casual observer, or, the elements of the units 3 may be contained within the racks themselves.

Referring now to figure 4, Unit 3 typically contains a control switch 4, this has a centre off position and may be pushed to the left or right to cause movement of the rack in the same direction. This switch may consist of any suitable switch means, it is not necessarily a single switch, not always operated by a lever and could even be a proximity device or two separate push button switches shown in figure 4 as a left hand movement switch 24 and a right hand switch 25. A battery 9 is housed in each unit as are the control logic systern and batf clharging electronics together with two combined limit switch and power contact means 14 and 15, mounted at each end of the unit. These means, 14 and 15 are identical in construction to each other, being simply turned over and reversed to fit at either end.

The combined limiting switch and power contact means can be seen in more detail in Figure 6. The contact 11 is biased out by spring 17 bearing against the insulator 23 and the micro switch actuator 18. When the contact 11 is fully extended the actuator 18 pushed down the micro switch operating lever 20. This allows the logic system to know when the rack has reached the end point of its travel and to stop the motor even though the hand operated switch may still be calling for the motor to run. Contact surface 12 mates with the corresponding contact 5 (figure 3) in the next unit 3 or either one of the end stops 7 and 13, shown in figure 3. It will be seen that contacts 5 and 11 are identical left and right hand contacts respectively and contact surfaces 6 and 12 are also identical left and right hand contact surfaces.

Insulators are provided at 23,19 and 22 and these may take any known form.

The assembly shown in figure 6 which is the combined limiting switch and power contact means and is also shown as 14 and 15 in figure 4, is also contained within the end stops 7 and 13 in Figure 3.

A second switch may also be provided alongside switch 16. Such second switch being provided to ensure that when plunger 11 is not pressed in power is not provided to plunger 11. This offers protection against accidental short circuits which can be created by metal objects coming into contact with plunger 11 and surface 12.

Referring now to Figure 3, power is supplied from an end stop 7 and 13 to contacts 5 and 6 and 11 and 12 respectively. This power may be any voltage either AC or DC but in this particular example it is a suitable low voltage for operating battery charging control circuits contained within the logic unit 8. The batteries 9----ontinuously flLoat charged. Whez he switch 4 is operated the logic circuits start the motor 10 which may be powered directly from the battery. When a rack is moving it will be disconnected for a power supply and the logic unit is in control when the rack has travelled to meet another rack the contacts 11 or 5 are depressed causing the limit switches to operate stopping further travel and at the same time restoring charging power to the logic unit via contact and surfaces 5, 6, and 11,12 respectively. Power is passed from the end stops from rack to rack and racks may be supplied from either end depending on their position.

Systems may require an operator to hold the initiation switch 4, in an operating position to sustain movement and there may be provision in the logic unit for dealing with the situation where an operator releases the switch before a unit has completed it's travel. This could leave the unit without charging power. Means for warning of this situation or automatically correcting it may be included. For example, the unit may comprise two or more speeds of operation-a normal speed, for use when the battery is fully or satisfactorily charged and a slower'limp'speed for when the battery power is significantly depleted. The shelving unit, or each rack thereof may be provided with a light to indicate that it is operating in'limp mode'to alert a user to the fact that a rack should be placed in a position where the batteries may be charged.-The unit may also be arranged to emit an audible alarm, perhaps in the form of a'chirrrup'such as is familiar from the art of smoke detectors and the like, to indicate that a battery is low on charge. Indeed, the shelving unit may comprise charging or jump leads which can be used to supply power from an end unit to a shelving rack which has run out of battery power away from its normal charging position.

It will be understood that there are many different methods of implementing the invention, the different elements do not need to be contained in one single housing. Charging systems are normally part of the rack mounted electronic units 8, but may be located in the end stops or anywhere which is not in the racks themselves. Or inverters may be used to supply higher voltages to the motors. A hich use the mderlying principal of a contact feed system and a battery for the provision of power when the racks are moving, which removes the need for expensive trailing lead systems.

The control system so far described is a simple system for controlling the movement of one storage rack at a time and it will be understood that this is described by way of example only. It is envisaged that much more complex control systems may be incorporated operating in various ways to control the movement of more than one storage rack at a time, known as Block Movement Control. One such system for example may involve the operation of the movement initiation control on several racks in order to prepare them to follow the leading rack once it is moved. One or more racks may be caused to follow the leader opening up a new isle several racks distant from the rack which is leading the movement.

A number of different logic systems may be used in order to control this and to ensure safety. ~The initiation of movement for each rack involved may not be simultaneous. Such systems may be equipped with audible and/or visual warnings of fault conditions and safety time outs and the individual limit switches attached to each rack would assist in providing input to the logic units. In some embodiments, the shelving unit may be controlled by one or more microprocessors and all or part of the control circuit may be contained on oe or more Printed Circuit Boards (PCB).

In one embodiment, the racks are moved by a motor driving a planetary gearbox. The advantage of such a gear arrangement is that the system could start at one speed then speed up, in a'soft start'. This means the risk of the load carried on the shelving falling off when movement starts is minimised.

In addition, a planetary gearbox is capable of being reverse-driven by the inertia of the load when power to the driving motor is removed. This reduces the strain and wear on the gearing mechanism. This is also a useful safety feature providing a controlled braking system.

Power may be supplied to the end units from a mains supply, possibly a transformer.

Each feature disclosed in the specification, including the drawings, may be replaced by alternative features serving the same, equivalent or similar purpose unless expressly stated otherwise. Thus unless expressly stated otherwise each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiments, the invention relates to any novel one or any novel combination of the features disclosed in this specification including any accompanying claims and drawings.