Please select the most similar patent number from A, B, C and D. Which number is?
Disclosed is a rocking chair, comprising a support frame (1). The support frame (1) is provided with a seat body (2). The seat body (2), at the approximate centre of gravity thereof, is rotatably connected to the support frame (1). A drive device (3) for driving the seat body (2) to turn is provided between one end or the middle of the seat body (2) and the support frame (1). The drive device (3) comprises a drive motor (30). A first rotating member (31) is fixed to a motor shaft of the drive motor (30), and the first rotating member (31) is pivoted with a drive assembly eccentrically connected with same so as to drive the seat body (2) to turn relative to the support frame (1). A locking device (4) is provided between the support frame (1) and the seat body (2) for locking or unlocking same. The locking device (4) comprises a turning position (401) and a locking position (402) provided on the support frame (1) or on the seat body (2), and the seat body (2) or the support frame (1) is provided with locking member (403), at least a part of the seat body (2), by means of same, starting to turn, at an angle, from the turning position (401) relative to the support frame (1) and then being locked and fitted with the locking position (402) to lock the seat body (2) onto the support frame (1). The rocking chair has a simple structure and is safe.
A: A reverse shipbuilding jig frame structure, comprising a plurality of vertically arranged supports (1) and a support frame (2) connected to the plurality of supports (1), wherein the support frame (2) is horizontally arranged and is used for supporting a ship hull, and vertically arranged support rods (3) are connected to the supports (1); the supports (1) are provided with drive devices that drive the support rods (3) to move in a vertical direction; the drive devices comprise support blocks (4) fixed on the supports (1); connecting blocks (5) are detachably connected to upper surfaces of the support blocks (4); vertically arranged connecting cylinders (6) are rotatably connected to the connecting blocks (5); the support rods (3) vertically penetrate the connecting blocks (5) and the support blocks (4), and are threadedly connected in the connecting cylinders (6); and the drive devices further comprise driving mechanisms arranged on the supports (1) and driving the connecting cylinders (6) to rotate.
B: Disclosed is a rocking chair for children, the rocking chair comprising a seat body (1), a supporting frame (2), a seat body limiting mechanism (3), a driving electric motor (5), a driving electric motor power output portion (6), and a rotating shaft (7). One end of the rotating shaft (7) is fixedly connected to the driving electric motor power output portion (6); the seat body (1) pivots around the other end of the rotating shaft (7); when the rotating shaft (7) rotates, the pivot point between the other end of the rotating shaft (7) and the seat body (1) moves relative to the fixed connection point between one end of the rotating shaft (7) and the driving electric motor power output portion (6) at a certain distance; the driving electric motor (5) and the driving electric motor power output portion (6) are arranged on a mounting box (8); the mounting box (8) is fixedly connected to the seat body (1); and the seat body limiting mechanism (3) can limit, when the driving electric motor (5) drives the rotating shaft (7), an included angle between the seat body (1) and the rotating shaft (7) to be kept within a set angle for forward and reverse rotation in a reciprocating manner. The rocking chair is simple in terms of structure, low in cost, large in terms of swing amplitude, stable in terms of seat body and capable of carrying out two different swing manners at the same time.
C: A mounting support for a height-adjustable table, comprising a support frame assembly (1) and two groups of upright post assemblies (2) rotatably provided on left and right sides of the support frame assembly (1), respectively, the two groups of upright post assemblies (2) both being provided with a locking device (3) capable of locking or unlocking the support frame assembly (1). When an upright post support leg (16) needs to be stored, a telescopic upright post support leg (16) is first retracted, then unlocking projection portions (13) are pressed inwards by hand, latching boards (7) are subjected to a force and then compress a locking spring (9) inwards, locking projection portions (11) move inwards and are disengaged from locking slots (10), the locking device (3) is unlocked, then an upright post mounting plate (15) is turned downwards, and the upright post mounting plate (15) drives the upright post support leg (16) to be retracted right below the support frame assembly (1); when the upright post support leg (16) needs to be unfolded, the upright post mounting plate (15) is turned upwards, and the upright post mounting plate (15) drives the upright post support leg (16) to be unfolded; and when the locking projection portions (11) move to the locking slots (10), the locking device (3) performs locking, and the upright post support leg (16) securely supports the support frame assembly (1). The operation is easy and the mounting efficiency is high.
D: A child car seat locking device, for coordinating with a lock rod (9) on a car seat to connect a child car seat to the car seat; the locking device comprises a mounting rack (1), and a locking piece (2) rotatably connected to the mounting rack (1) via a first shaft (7); a lock slot (11) for accommodating the lock rod (9) is formed on the mounting rack (1), a lock hook (23) for hooking on the lock rod (9) is formed on the locking piece (2) so that the lock rod (9) is locked in the lock slot (11); the locking device further comprises a button (4) and a stop block (3) moving in the length direction of the mounting rack (1); the button (4) is provided with a drive pin (41) thereon; a drive slot (21) is formed on the locking piece (2); the drive pin (41) is movably inserted in the drive slot (21), and the movement of the button (4)drives the locking piece (2) to rotate around the first shaft (7); the stop block (3) has two operating positions: at a first operating position, the stop block (3) presses against the lock hook (23) or the locking piece (2) to allow the lock hook (23) to deflect from the lock slot (11), and the lock rod (9) inserted into the lock slot (11) pushes the stop block (3) away from the first operating position, so that the stop block (3) moves to a second operating position to release the locking piece (2); and the locking piece (2) rotates to the lock hook (23) and reaches a position corresponding to the lock slot (11), so as to hook the lock rod (9).
Answer: B