OPERATING DEVICE FOR LAUNCHING A LIFEBOAT

Abstract: Disclosed is an operating device for launching a lifeboat (2) from a ship (1), comprising carrying means for carrying the lifeboat relative to the ship by means of at least one cable (4), pay-out means (5) for paying out the at least one cable, and control means (10) for controlling the pay-out means from the lifeboat. Such an operating device is improved according to the invention in that the control means comprise a wireless communication path from the lifeboat to the ship, a transmitter (10) being arranged on board of the lifeboat and a receiver (12) being arranged on board of the ship, said receiver being adapted for operating the pay-out means in response to receiving a command signal transmitted by the transmitter.

Description: Title: Operating device for launching a lifeboat This invention relates to an operating device for launching a lifeboat from a ship, comprising carrying means for carrying the lifeboat relative to the ship by means of at least one cable, pay-out means for paying out the at least one cable, and control means for controlling the pay-out means from the lifeboa . Such a device is disclosed in German Auslegeschrift 1,905,388. Many ships are equipped with a lifeboat, which is on board of the ship in an inoperative position and, for instance in an emergency, can be launched by means of a cable. For that purpose, a winch device is provided on board of the ship. This winch device includes a drum having the cable wound thereon and comprising a brake element. The brake element can be set in two main operative positions, i.e., a brake position in which the brake element prevents rotation of the drum and a release position in which the brake element releases the drum so that the cable unwinds off the drum and the lifeboat is lowered. In many cases, it is desirable, or even required by regulation, that the winch device or the brake element is operable from the lifeboat. The publication referred to discloses an additional control cable for that purpose, which is unwound off an associated drum simultaneously with the carrying cable, the end of the additional cable extending into the lifeboat. Adjacent the associated drum, the control cable is coupled with an operating lever of the brake element. When the control cable is taut, for instance because an operator pulls the end of the cable, the operating lever of the brake element is maintained in a lifted position and the brake element is in the release position. When the control cable is not taut, the operating lever of the brake element is maintained in the lowered position as a result of gravity and the brake element is in the brake position. However, a number of disadvantages are associated with this known device. It must be possible to lift the operating lever of the brake element by hand, which limits the maximum permissible weight of the operating lever or a corresponding counterweight. During lowering of the lifeboat, an operator must constantly exert a pulling force on the control cable. The control cable must be passed over a plurality of guiding rollers or pulleys, with the result that a frictional force is exerted on the operating cable. When this frictional force exceeds a given level, control of the operating mechanism is no longer possible. Although the control cable is unwound synchronously with the carrying cable, the end of the control cable does not come down at the same speed as the lifeboat because the control cable must be thinner than the carrying cable. A reason for this is that the carrying cable must carry the weight of the lifeboat and therefore must have a given minimal thickness, while a proper transmission of the control force is not very well possible if the control cable has that same minimal thickness. Consequently, during lowering of the lifeboat, the end of the control cable or a handle attached thereto is not at all times at the same level relative to the lifeboat. This is undesirable and may even cause a dangerous situation if the operator keeps the end of the control cable wound around his hand. A further disadvantage is that, in the lifeboat, control of the operating mechanism is possible only at the point where the control cable reaches the lifeboat. The control cable is passed along several locations outside the lifeboat. On the one hand, this increases the chances of undesired operation and, on the other, this requires guiding means, such as guiding rollers, which contribute to the frictional force exerted on the control cable. Further, it is an objection that such a mechanical control means requires regular maintenance, in particular including a check of the proper operation of the guiding means, since control of the operating mechanism is rendered impossible if these guiding means exert too high a frictional force. It is an object of the invention to remove the above disadvantages. To that end, the operating device of the type described above is characterized in that the control means comprise a wireless communication path from the lifeboat to the ship, a transmitter being arranged on board of the lifeboat and a receiver being arranged on board of_ the ship, said receiver being adapted for operating the pay-out means in response to receiving a command signal transmitted by the transmitter. The frequency at which the transmitter and receiver are operative can be chosen freely, although account must be taken of the possiblity not only of interference due to CB-ers or radio hams, radio or TV transmitters and the like, but also of interferent radiation coming from the ship itself. A frequency band where the operation of the device according to the invention has been shown in practice to be free or substantially free of interference, is the 450 MHz band. Accordingly, the use of this band is preferred. Hereinafter, the invention will be further explained by the description of preferred embodiments of the operating device according to the invention, w:.th reference to the accompanying drawings . In said drawings: Fig. 1 is a view of a ship with a lifeboat; Fig. 2A is a top plan view of a brake element for a winch device; Fig. 2B is a front view of the brake element; Fig. 2C is a more detailed view of a part of an embodiment of the operating device according to the invention; and Fig. 3 is a diagram of connections of an embodiment of the operating device according to the invention. Fig. 1 is a section of a part of a ship 1 equipped with a lifeboat 2 carried by a cable 4 passed along a tilting arm 3. During normal operation of the ship 1, i.e., in an inoperative position of the lifeboat 2, the arm 3 is in a substantially vertical position (at A) and the lifeboat 2 is secured relative to the ship by means of locking means which have been omitted for clarity. In an operative position of the lifeboat 2, for instance when the ship 1 is in distress, the arm 3 is in a substantially horizontal position (at B) in order to keep the cable 4 alongside of the side of the ship 1 so that the lifeboat 2 is suspended above the water. Arranged adjacent the fulcrum of the arm 3 is a winch device 5 comprising a drum onto which the cable 4 is wound. As shown in Fig. 2 in more detail, the drum is connected, for instance through a gear transmission, to a brake element 7 comprising a lever 8 having a counterweight 9. The brake element 7 is of a type that is known as such, and does not form a part of the present invention, and therefore a detailed description thereof is dispensed with. Suffice it to say that the brake element 7 is so constructed that if no external force other than gravity is exerted on the lever 8, the counterweight 9 is retained in the pulled-down position by gravity and the brake element 7 is in a brake position where the brake element 7 prevents rotation of the drum. If an external force is exerted on the lever 8 so that the counterweight 9 is maintained in a lifted position, the brake element 7 is in a release-position where the brake element 7 releases the drum so that the cable 4 unwinds off the drum, with the arm 3 tilting from the vertical position into the horizontal position and the lifeboat 2 subsequently lowering into the water. According to the invention, the launching can be controlled from the lifeboat 2 via a wireless communication path. For that purpose, the lifeboat 2 comprises a transmitter, generally indicated by reference character 10, for transmitting a suitable signal 11, preferably a signal of a frequency in the 450 MHz band, and the ship 1 is equipped with a receiver, generally indicated by reference character 12, for receiving these signals. Preferably, the communication path is coded, i.e., the transmitter 10 transmits a coded signal with a predetermined code, for instance a pulsating signal, while the pulse width and/or pulse repeat time and/or number of pulses per pulse train can be predetermined. This has an advantage in that the launching of the lifeboat 2 is not undesirably influenced by any noise signals and it provides the possibility of individually controlling the launching of a plurality of lifeboats, even of the same ship, using the same carrier wave frequency but different codes. The receiver is adapted to operate the winch device in response to receiving a properly coded signal. In the embodiment described, where the receiver is suitable for use in an existing winch device comprising a brake device of the type comprising a brake lever, the receiver comprises means 20 for operating the winch device 5 through operation of the lever 8. In a simple embodiment, the operating means 20 comprise a motor 21 having an output shaft 23 coupled to the motor 21, for instance via a reduction device, the shaft 23 having a disc 24 mounted thereon. The disc 24 is arranged adjacent the lever 8 and, for instance through interposition of a guiding roller 25 attached to the lever 8, can be contacted with the lever 8 by rotation about the shaft 23, so as to counteract the force exerted by gravity on the counterweight 9. The disc 24 may be a curve disc or a cam disc of an appropriate circumferential contour adjusted to the use in the specific situation. The disc 24 comprises at least one first circumferential portion having a minimal distance from the output shaft 23 and at least one second circumferential portion having a maximum distance from the output shaft 23. In a first operative position of the disc 24, the first circumferential portion is directed to the lever 8 and the guiding roller 25 and the disc 24 is not in contact with the lever 8 or the guiding roller 25, so that the counterweight 9 is retained in the pulled-down position by gravity and the brake element 7 is in the brake position. Accordingly, in this first operative position, the winch device 5 is not influenced by the means 20, while the possibility of manual operation of the lever 8 is maintained. In a second operative position, the disc 24 has been rotated relative to the first operative position through an appropriate angle α, in which position a circumferential portion of the disc 24 is in contact with the lever 8 or the guiding roller 25 so as to keep the counterweight 9 in a lifted position so that the brake element 7 is in the release position. To bring the disc 24 from the second operative position back into the first operative position, it must be rotated back through angle α. Preferably, angle α is chosen to be equal to the angular distance between the first circumferential portion and the second circumferential portion. On the one hand, this provides for a largest possible stroke for the lever 8 and, on the other, it provides for the possibility of bringing the disc 24 from the second operative position back into the first operative position without the necessity of reversing the direction of rotation. Further, mounted on the shaft 23 is a switching disc 27 comprising at least two recesses 28 which are mutually spaced apart by the angle α. The switching disc 27 serves for controlling a proximity switch 37. A contact 39 of the proximity switch 37 is open in an inoperative position and closed when the proximity switch 37 is operated by the portions of the switching disc 27 disposed between the recesses 28. In the embodiment shown, the disc 24 is substantially circular and mounted eccentrically on the output shaft 23. The above-mentioned first circumferential portion is defined by the circumferential portion which is located closest to the shaft 23, and has a recess 26 provided therein. The above- mentioned second circumferential portion is defined by the circumferential portion that is spaced 180° from the recess 26, i.e., the angle α is 180°. Fig. 2C is a more detailed view to an enlarged scale of the disc 24 and the switching disc 27. Referring to Fig. 3, the operation of the disc 24 by the receiver will now be discussed, starting from the situation where the disc 24 is in the first operative position. Fig. 3 shows the proximity switch 37 as a tiltable switch lever 37 which is biased in the direction of the switching disc 27 through means (not shown) , for instance a spring member, and in the position of the switching disc 27 that corresponds to the first operative position, a projection 38 provided on the switch lever 37 engages a recess 28 of the switching disc 27 and the contact 39 is open. Via a terminal 31, the receiver 12 is connected to a DC voltage source, for instance an output of a rectifier connected to an AC circuit. The receiver 12 is arranged to momentaneously supply a voltage signal at an output 33 to an operating coil 34 of a relay 35, in response to receiving a predetermined signal, received through an antenna 32, which signal is indicative of a command, transmitted wirelessly from the lifeboat 2, to bring the brake device 7 into the clear- position, hereinafter referred to by the term of "clear-coir and signal". As a result, a relay contact 36 is closed, thereby linking the motor 21 to the terminal 31, so that the motor 21 will rotate. The switching disc 27 rotating along with it, will move the switch lever 37 against the action of the biasing means, so as to close the contact 39. The duration of the control signal supplied by the receiver 12 at the output 33 is shorter than the time the motor 21 requires to rotate the shaft 23 through 180°. Therefore, the contact 36 opens at the end of said control signal before the disc 24 has rotated through 180°. At that time, however, the contact 39 has already closed, thereby keeping the motor 21 linked to the terminal 31. Not until the projection 38 engages the next recess 28 of the switching disc 27, i.e., when the switching disc 27, and hence the disc 24, has rotated through 180°, does the contact 39 open and does the rotation of the motor 21 stop. The disc 24 is then in the second operative position. The receiver 12 is further arranged to momentaneously supply a voltage signal at an output 33 again, in response to receiving a predetermined signal, received via the antenna 32, which signal is indicative of a command, transmitted wirelessly from the lifeboat 2, to bring the brake device 7 into the brake position, hereinafter referred to by the term "brake-command signal". In a manner similar to that described above, the switching disc 27, and hence the disc 24, are thereby rotated further through 180°. The disc 24 is then in ■ the first operative position again. Optionally, a hand switch 40 can be provided on board the ship 1, which may be connected in parallel with the relay contact 36, permitting manual control of the motor 21 from the ship 1. It is observed that for safety reasons each combination of a receiver 12 and a motor 21 controlled thereby, associated with an individual lifeboat 2, may be provided with a separate DC voltage source. To enable operation of motor 21 even in the case of failure of the AC circuit of the ship, it is preferred that a battery having an operating voltage of 12 V, for instance, is provided, which, in a known manner, may be connected via a battery charger to the AC circuit so as to ensure the charged condition of the battery. It is further observed that the above-described embodiment permits manual operation of the lever 8 of the brake element 7, enabling the lifeboat 2 to be launched even in the case of failure of one of the electric and/or of the electronic means . In one embodiment, the transmitter 10 is arranged for operation by means of a single operating switch, for instance a press button switch or a lever switch. In this embodiment, the transmitter 10 can be adapted to transmit the release- command signal upon a first operation of the one operating switch and to transmit the brake-command signal upon a second operation of the one operating switch. As an alternative, the transmitter 10 can be adapted to transmit the clear-command signal upon operation of the one operating switch and to transmit the brake-command signal upon release of the one operating switch. In this case, the method of operation corresponds to what has been conventional heretofore, namely, the continuous operation of an operating device as long as it is desired for the lifeboat 2 to be lowered. In another embodiment, the transmitter 10 is adapted to transmit the clear-command signal upon operation of a first operating switch, and to transmit the brake command signal upon operation of a second operating switch. In this case, the risk of operational errors as a consequence of unintentional operation or release of the one operating switch is reduced. In one embodiment, the clear-command signal is provided by the presence of a signal that is continuously transmitted by the transmitter 10, and the brake-command signal is provided by the absence of a signal transmitted by the transmitter 1C, the receiver 12 being adapted to momentaneously provide a first control voltage pulse at the output 33 in response to receiving the signal and to momentaneously provide a second control voltage pulse at the output 33 in response__to the end of said signal. In another embodiment, the clear-command signal is provided by a first signal pulse transmitted by the transmitter 10 and the brake-command signal is provided by a second signal pulse transmitted by the transmitter 10, the receiver 12 being adapted to momentaneously provide a control voltage pulse at the output 33 each time in response to receiving the first or the second signal pulse. Thus, an energy source of the transmitter 10 is loaded only momentaneously. The coding of the clear-command signal may be different from the coding of the brake-command signal and the receiver 12 may be adapted to provide a control voltage pulse in response to receiving a clear-command signal when the disc 24 is in the first operative position and to provide a control voltage pulse in response to receiving a clear-command signal when the disc 24 is in the second position. If the transmitter is of the type that is suitable for operation by means of two operating switches, thus a further protection against unintended operation of one of the operating switches is provided. Such protection can also be provided if the transmitter 10 is adapted to transmit a command signal pulse only once upon operation of a corresponding operating switch and to transmit a next command signal pulse only upon operation of the other operating switch. It will be clear to a skilled worker that it is possible to change or modify the embodiment of the invention as shown without departing from the concept of the invention or the scope of protection. Thus, it is for instance possible for the switching disc to be provided with projections instead of recesses. Also, instead of a switching disc, other means can be used to ensure that the disc 24 always rotates through the proper angle. When an appropriate reduction device is used, such other means may for instance count the number of revolutions performed by the motor. It is also possible to use a stepping motor and a control device suitable therefor. It is also possible for the disc 24 to have a spiral circumferential portion, so that the first and the second circumferential portion are nearly 360° apart. It is even possible for the operating means 20 to be of the linear type, instead of the rotating type, the use of a linear motor being of advantage in that case. Further, it is possible that a winch device is provided that is directly operable by a motor, the drive of the motor being adjusted to this situation. Finally, if so desired, it is possible for the transmitter and the receiver to be operative at other frequencies, such as the 27 MHz band, the 35 MHz band, the 40MHz band or the 70 MHz band, in those situations where the nature and location of the ship virtually precludes the chance of interference.

Claims: CLAIMS 1. An operating device for launching a lifeboat from a ship, comprising carrying means for carrying the lifeboat relative to the ship by means of at least one cable, pay-out means for paying out the at least one cable, and control means for controlling the pay-out means from the lifeboat, characterized in that the control means comprise a wireless communication path from the lifeboat to the ship, a transmitter being arranged on board of the lifeboat and a receiver being arranged on board of the ship, said receiver being adapted for operating the pay-out means in response to receiving a command signal transmitted by the transmitter. 2. An operating device as claimed in claim 1, characterized in that the transmitter transmits a signal, the frequency of which is selected to be in the 450 KHz band. 3. An operating device as claimed in claim 1 or 2, characterized in that the wireless communication path is coded. 4. An operating device as claimed in at least one of claims 1-3, characterized in that: the transmitter is adapted for operation by means of one operating switch; and the transmitter is adapted to transmit a pay-out command signal upon a first operation of the one operating switch and to transmit a stop-command signal upon a second operation of the one operating switch. 5. An operating device as claimed in at least one of claims 1-3, characterized in that: the transmitter is adapted for operation by means of one operating switch; and the transmitter is adapted to transmit a pay-out command signal upon operation of the one operating switch and to transmit a stop-command signal upon release of the one operating switch. 6. An operating device as claimed in at least one of claims 1-3, characterized in that the transmitter is adapted to transmit a pay-out command signal upon operation of a first operating switch and to transmit a stop-command signal upon operation of a second operating switch. 7. An operating device as claimed in at least one of claims 4-6, characterized in that: the pay-out command signal is provided by the presence of a signal transmitted continuously by the transmitter; the stop-command signal is provided by the absence of a signal transmitted by the transmitter; and the receiver is adapted to cause the pay-out means to pay out the cable in response to receiving the signal transmitted by the transmitter and to cause the pay-out means to retain the cable in the absence of a signal transmitted by the transmitter. 8. An operating device as claimed in at least one of claims 4-6, characterized in that: the pay-out command signal is provided by a first signal pulse transmitted by the transmitter; the stop-command signal is provided by a second signal pulse transmitted by the transmitter; and the receiver is adapted, in response to receiving a signal pulse transmitted by the transmitter, to cause the pay-out means to alternately pay out the cable and retain it. 9. An operating device as claimed in at least one of claims 4-6, characterized in that: the pay-out command signal is provided by a signal pulse, transmitted by the transmitter, having a first code; the stop-command signal is provided by a signal pulse, transmitted by the transmitter, having a second code different from the first code; and the receiver is adapted to cause the pay-out means to pay out the cable in response to receiving the pay-out command signal and to cause the pay-out means to retain the cable in response to receiving the stop-command signal. 10. An operating device as claimed in at least one of claims 1-9, characterized in that the receiver is suitable to be used in an existing winch device of the type that is provided with a brake device comprising a brake lever and, for that purpose, comprises means for operating the winch device by operation of the lever. 11. An operating device as claimed in claim 10, characterized in that the means for operating the lever comprise a disc mounted on an output shaft of a motor, said disc having a circumferential portion of an appropriate configuration, comprising at least one first circumferential portion having a minimal distance from the output shaft and at least one second circumferential portion having a maximum distance from the output shaft, said second circumferential portion having an angular distance α relative to the first circumferential portion. 12. An operating device as claimed in claim 11, characterized in that the disc is substantially circular and mounted eccentrically on the output shaft, and that a recess is provided in the circumferential portion of the disc that is closest to the output shaft. 13. An operating device as claimed in claim 11 or 12, characterized in that the receiver is adapted to rotate the output shaft of the motor through the angle α in response to receiving the pay-out command signal, and that the receiver is adapted to rotate the output shaft of the motor back through the angle α in response to receiving the stop-command signal. 14. An operating device as claimed in claim 11 or 12, characterized in that the receiver is adapted to rotate the output shaft of the motor through the angle α in response to receiving the pay-out command signal, and that the receiver is adapted, in response to receiving the stop-command signal, to rotate the output shaft of the motor further through an angle which is equal to the angle between the second circumferential portion of said disc and a next first circumferential portion of said disc. 15. An operating device as claimed in claim 13 or 14, characterized in that a switching disc is connected to the operating disc, said switching disc comprising first and second switch operating portions for operating a switch, the angular distances between the first and second switch operating portions corresponding to the angular distances between the first and second circumferential portions of said disc. 16. An operating device as claimed in claim 15, characterized in that the receiver is adapted, in response to receiving an appropriate signal from the transmitter, to rotate the output shaft of the motor through a predetermined angle which is smaller than the total desired angle of rotation, and that the rotation of the output shaft of the motor through the remaining part of the total desired angle of rotation is maintained by means of the switch operated by the switching disc. 17. A combination of a ship and at least one lifeboat, comprising an operating device as claimed in at least one of claims 1-16. 18. A receiver, suitable for use in an operating device as claimed in at least one of claims 1-16. 19. A ship comprising a receiver as claimed in claim 18. 20. A transmitter suitable for use in an operating device as claimed in at least one of claims 1-16. 21. A lifeboat comprising a transmitter as claimed in claim 20.

Inventors: KNOOP JAN WILLEM, KNOOP, JAN, WILLEM
Applicants: MARINE AND LIFESAVING EQUIPMEN, MARINE AND LIFESAVING EQUIPMENT (NETHERLANDS) B.V.
Application year: 1991
Main classification: B63B23
IPC codes: B63B23