The present invention relates to an apparatus as defined in the preamble of claim 1 for controlling the slide doors in a vessel's bulkhead especially in an emergency when the vessel's normal electricity distribution system is out of use.

The space in a ship that lies below the water level is divided into compartments by means of transverse and partly also longitudinal waterproof walls, so-called bulkheads. Dividing the space in this way reduces the risk of the vessel sinking if it should touch bottom or have a similar misadventure.

To permit access to the various spaces in the vessel, these bulkheads must of course be provided with doors. International maritime law stipulates that bulkheads should be provided with waterproof doors. This makes it possible to prevent masses of water that have penetrated into one space from getting further into adjacent spaces. The safety regulations relating to the doors are particularly strict for passenger ships, in which a large number of such doors, usually 15 - 30 pcs, are installed.The structure and operation of the doors is largely controlled by international regulations, published in the "SOLAS Regulation 15", SOLAS Consolidated Edition 1992. According to these regulations, it must be possible to close the doors simultaneously by remote control from the navigation bridge by using the ship's normal electricity distribution system, and the closing operation must not take more than 60 seconds when the ship is in an upright position. For cases of emergency, in which the normal electricity distribution system is in most cases out of use, the above-mentioned regulations contain specific provisions in section 7.1.4.

According to these rules, each door must be provided with a manually operated mechanism allowing the door to be closed and opened from both sides. In addition, manually operated equipment for closing the doors by remote control must be provided on a deck above the water level (bulkhead deck) , and the closing operation should not take more than 90 seconds when the ship is in an upright position. For catastrophic situations, the space below the water level is divided into a number of separate compartments. Each one of these compartments is controlled by its own so-called emergency centre, which must be located on the bulkhead deck. The doors in each one of these compartments are closed from the appropriate emergency centre.

The control of bulkhead slide doors by means of an electromotor is known e.g. from patent specification DE 923 053, which proposes an apparatus for the closing of bulkhead doors, in which the motors controlling the doors are fed in an emergency by a reserve power generator.

In previously known systems, manually operated hydraulic pumps are used for remote control of the doors from the emergency centre. Each emergency centre has a hydraulic pump for each door. In addition, each door must be provided with one or two hydraulic pumps. However, this system has several drawbacks, the most significant of which are the following:

1) Very expensive pipelines need to be installed within the ship, passing through several decks and bulkheads (often made of stainless material) to a place that, in some cases, may be over 40 m removed from the door. The door unit itself is expensive, too.

2) The systems are often complex and susceptible to

disturbances caused e.g. by particles of dirt that may have got into the pipes at the time of installation or through valves or other movable parts during use.

3) Closing the doors with a manual hydraulic pump requires a hard physical effort and consequently it often takes more time in practice than is allowed by the regulations.

4) The pumps for individual doors are placed close to each other, which makes it impossible for the pumps to be manned at the same time. Therefore, the doors are not closed simultaneously.

5) An emergency system provided with hydraulic pumps cannot compensate for other disadvantages caused by a power failure, such as the extinction of warning lights and the interruption of alarm signals that are normally required for the control of the doors.

6) Hydraulic oil always involves a fire hazard and hygienic disadvantages.

The object of the present invention is achieve a simple remote control apparatus that is free of the drawbacks mentioned above. The features characteristic of the apparatus of the invention are presented in detail in the attached claims. Each door may be provided with its own electromotor. Each emergency centre may have a separate manually operated electricity generator for each motor, but alternatively one and the same generator can be used to supply electricity to several motors. In principle, all the motors in the emergency centre can be controlled by electricity obtained from the same generator.

The apparatus of the invention is simple in structure, cheap to install and maintain and it is practically free of operating disturbances and indepenent of interruptions in the supply of electricity by the normal power supply system. The apparatus accomplishes fast and simultaneous closing of several or even all of the doors of an emergency centre while requiring only minimal physical effort.

Since the generator is rotated manually and there are no other intermediate linkages between the crank and the rotor than a possible transmission system in the generator nor between the door closing mechanism and the rotor in the electromotor, the operation of the system is not affected by external factors. The overall dependability of the remote control system is therefore as good as possible.

The electricity obtained from the manual generator can also be used to maintain the operation of the warning lights and alarm signals that are normally used for door control but which cannot be maintained in emergencies using current hydraulic pump systems. Here is a significant advantage that increases the safety and rescue capacity of crew and passengers.

By using a manually operated generator with continuous rotary motion instead of a reciprocating pump, increased power and a reduced demand are achieved for the same closing speed as compared with a conventional single action manual pump. Energy losses are much smaller in an electric system than in a hydraulic system, and they can be further reduced significantly by selecting larger electric conductors.

The electric generators and motors are preferably direct-current machines. Direct-current machines have the

advantage that the rotation need not be bound to a given number of revolutions per minute, but the closing speed of the doors is directly proportional to the speed of rotation of the manually rotated generator.

In d.c. machines, the power requirement is directly proportional to the door closing speed, which again faithfully follows the voltage (e.g. 0 - 24 V) . The closing can therefore be accomplished with a very modest power, and the closing movement of the door is started at a very low speed of rotation. Thus, it is fully possible to close several doors at the same time with the current produced by the same manual generator.

The apparatus of the invention provides new possibilities for the placement of the remote control unit. The manual generator can also be placed on the navigation bridge in addition to the emergency centre as required by the regulations. This makes it possible to close the doors from the bridge as well if necessary. This arrangement would also provide the advantage that, via an operative alarm and warning system maintained by means of a manual generator, the crew could be informed about the position of the doors.

The apparatus of the invention needs particularly little supervision and maintenance. During short-duration test closing operations, the generator and the motors will not nearly reach their normal lifetime limit during the whole usable life of the ship. In building the ship, substantial economies are achieved partly because of the cheaper door units, but primarily because the long and expensive piping systems can be omitted.

In the following, the invention is described in detail by

the aid of examples by referring to the attached drawings, in which Fig. 1 presents a slide door unit as provided by the invention, Fig. 2 presents the system of the invention and Fig. 3 a simplified electrical scheme of the electricity distribution system.

Fig. 1 presents a slide door unit 10, which is fixed to a vertical bulkhead part and the deck by welding. The door unit consists of the door 11 itself, surrounded by a frame unit 12 consisting of double door frames welded together with transverse plates at the top, at the bottom and on both sides. When the door is closed, the door together with the frame unit forms a waterproof support. In the figure, the door is half-open, being partly inside the frame unit and partly covering the door opening 13. The door is preferably suspended by means of bolts provided with supporting wheels that run along a rail (not shown in the figure) . To reduce the power required to move the door, the unit can be provided with suitable guiding elements at both the top and the bottom edges to prevent transverse motion of the door so that it will not touch the door frame during the opening and closing movements. The door unit is provided with a manual opening and closing mechanism 20, a circuit breaker 21 and a control device 22 for local control. In the figure, the circuit breaker 21 refers to a push-button switch, but it does not exclude other types of switch, such as e.g. the so-called induction limit switch, which is required to ensure that the switch will also work under water pressure. The door suspension mechanism can be accessed via service holes 14, 15. The electric motor with the associated components and circuits is installed in a completely watertight, immersible box placed beside the door suspension and closing mechnism.

Fig. 2 presents the system of the invention in diagrammatic form in an application with three door units 10a, 10b and 10c placed on different decks Dl and D2 and provided with electric motors 30a, 30b and 30c, which all receive electricity via electric cables 32a, 32b and 32c from an electric generator 31 provided in an emergency centre on deck S. In this case, another manually operated electric generator 41 is placed on the navigation bridge K. If necessary, the motors 30a - 30c can thus be supplied with electricity from generator 41 via electric cables 41a - 41c.

Fig. 3 presents a simplified electrical scheme of the electricity distribution system, especially in reference to the control of the bulkhead doors. The ship has one or more main generators 50 supplying the ship's electric system with electricity through a main switching centre 51. From the main switching centre 51, electricity is supplied to a reserve power switching station 52, to which a reserve power generator 53 and, e.g. via an inverter 55, reserve power batteries 54 are also connected. The reserve power switching station 52 supplies electricity to a supervision unit 56 placed on the navigation bridge and containing e.g. the required indicators (warning lights etc.) for voltage, position of the doors and disturbances in the supply of electricity to the doors as well as control signals for local operation and closing of the doors. It may also be provided with an alarm buzzer.

The reserve power switching station 52 also supplies electricity to the emergency centre 32, which is located on the bulkhead deck S as shown in Fig. 2. The emergency centre 32 has a control unit 33 with the required switches, breakers and e.g. a rectifier to supply electricity to the direct-current motors 30a - 30c in emergencies when normal

electricity distribution has been interrupted. Moreover, the control unit 33 is provided with the required switches to supply electricity from a manual direct-current generator 31 to the motors 30a - 30c. The control unit 33 may additionally be equipped to detect the presence of a voltage and the open/closed status of the doors. It may also include voltage and current monitoring.

The generator 31 and the motors 30a - 30c are e.g. direct-current machines operated with a low voltage in the range 0 - 24 V, requiring but a small rotating power to close the doors as described above. The generator 31 takes care of the supply of electricity to the motors 30a - 30c when the normal electricity distribution has been interrupted. At the same time, the generator 31 can also supply electricity for the supervision unit 56, for the detection and monitoring functions in the control unit 33 and for the warning bells and lights at the door.

The electric generator 31 and motors 30a - 30c can be fully identical machines, they only have different designations according to their different uses.

The rotor of the electric generator can be connected to a gear with a transmission ratio such that by rotating one of the gear shafts at a slow rate, the generator rotor is caused to rotate within a rotational speed range that is suitable for it. The generator 31 produces a current that causes the electric motors 30a - 30c at the doors below to rotate at the same speed.

The door closing mechanism may consist e.g. of a trapezoidal screw to which the rotor of the electromotor is connected either directly or via a suitable transmission. The

electromotor is connected e.g. together with a reduction gear directly to the door operating mechanism.

The motor need not be disconnected during local manual operation and it is therefore continuously ready for operation, thus substantially increasing operating reliability. If the motor always remains mechanically connected to the door operating mechanism, it will function as a generator when the door operating mechanism is operated manually. In this case, functioning as a generator, the motor can supply electricity to the indication system of the door, which thus remains operative even if other electricity supply should be interrupted.

The use of a trapezoidal screw as a door operating mechanism has special advantages. This arrangement meets the requirement that the door must not be able to move by itself without the action of external forces under any circumstances. The trapezoidal screw is turned in a nut joined with the door, so the nut cannot cause the trapezoidal screw to turn. Thus, the door always remains in the position in which it was left when the action of the external force ceased.

It is obvious to a person skilled in the art that different embodiments of the invention are not restricted to the examples described above, but that they may instead be varied within the scope of the following claims.