Movable platform assembly for a boat, particularly for hauling or launching tenders or the like
A movable platform assembly comprises a base portion, able to be fixed to a support structure, and at least one pivotable arm hinged at one end with the base portion, about a first hinging axis, and at the other end with a loading platform, about a second hinging axis, the pivotable arm being able to be rotated by means of actuating devices, which are designed to allow the platform to maintain a constant inclination with respect to the base portion during rotation of the pivotable arm. The actuating devices comprise a first and a second rotary actuator mounted on the first and second hinging axis, respectively. The first rotary actuator comprises a first part fastened to the base portion and a second part rotatable with respect to the first part and fastened to the pivotable arm, and the second rotary actuator comprising a first part fastened to the loading platform and a second part rotatable with respect to the first part and fastened to the pivotable arm, said actuating devices also comprising control devices able to control in a co-ordinated manner rotation of said first and second rotary actuators.
1. Movable platform assembly, comprising
a base portion, configured to be fixed to a support structure,
at least one pivotable arm hinged at one end with said base portion, about a first hinging axis, and at the other end with a loading platform, about a second hinging axis, said at least one pivotable arm being configured to be rotated by means of actuating means, which are designed to allow said platform to maintain a constant inclination with respect to said base portion during rotation of said at least one pivotable arm,
wherein said actuating means comprise a first and a second rotary actuator mounted on said first and second hinging axis, respectively, the first rotary actuator comprising a first part fastened to the base portion and a second part ( 52 ) rotatable with respect to the first part and fastened to the pivotable arm, and the second rotary actuator comprising a first part fastened to the loading platform and a second part rotatable with respect to the first part and fastened to the pivotable arm, said actuating means also comprising control means configured to control in a co-ordinated manner rotation of said first and second rotary actuators,
wherein said control means comprise a reference inclination sensor fixed to the base portion and configured to provide a reference inclination signal indicating the inclination of the base portion, an alignment inclination sensor fixed to the loading platform and configured to provide an alignment inclination signal indicating the inclination of the platform, and a control unit programmed to compare with each other the values of the reference inclination signal and the alignment inclination signal and perform rotation of said first and second rotary actuators depending on said comparison, and
wherein said at least one pivotable arm is provided with a plurality of step elements which are mounted along a length of the at least one pivotable arm and are designed to allow easier access for persons to the loading platform; and
alignment means which connect the first part of the first rotary actuator to a plurality of transmission members which are respectively fastened to said step elements and are rotatable about axes parallel to the first hinging axis so as to allow said plurality of step elements to maintain in a constant manner substantially the same inclination of said loading platform during rotation of said at least one pivotable arm.
2. Platform assembly according to claim 1 , wherein said control means also comprise a movement inclination sensor fixed to the swing arm and configured to provide the control unit with a movement inclination signal indicating the inclination of the swing arm, said control unit being programmed to compare with each other the values of the reference inclination signal and the movement inclination signal, so as to be configured to determine an angle of rotation of the swing arm with respect to the base portion.
3. Platform assembly according to claim 1 , wherein said at least one pivotable arm is formed as a pair of parallel pivotable arms and said first and second rotary actuators are formed as dual rotary actuators, the respective first parts of which are formed as end shafts which are respectively fixed to the base portion and to the loading platform.
4. Platform assembly according to Claim 1 , wherein said transmission members are respectively formed as pulley elements, each fastened to the respective step element, said alignment means being configured as a chain which connects the pulley elements of the step elements to the first part of the first rotary actuator so that these pulley elements are configured to rotate in the same sense with respect to the pivotable arm.
5. Platform assembly according to claim 1 , also comprising alignment means formed by a system of levers which connect together said step elements so as to allow said plurality of step elements to maintain in a substantially constant manner the same inclination of said platform during rotation of said at least one pivotable arm.
6. Platform assembly according to claim 1 , wherein said support structure is a boat.