Please select the most similar patent number from A, B, C and D. Which number is?
Disclosed is a suitcase convertible into a seat, comprising: a suitcase body comprising a front suitcase housing and a rear suitcase housing; and a safety guard bar comprising a first connection rod, a support rod, and a second connection rod. One end of the first connection rod is movably connected to a top portion of the rear suitcase housing, the other end of the first connection rod is connected to one end of the support rod, and the other end of the support rod is connected to the second connection rod. The first connection rod and the second connection rod are both provided perpendicular to the support rod. The support rod coincides with a rotation plane formed when the first connection rod is turned upside down. A flat surface defined by the support rod and the second connection rod is perpendicular to a flat surface defined by the first connection rod and the support rod. The invention enables full use of a suitcase, and allows users to take a seat anywhere and at anytime during a long journey.
A: A lifting device and an automated guided transport vehicle. The lifting device comprises: a base and a first link mechanism (10) provided on the base. The first link mechanism (10) comprises a first link (102) to a sixth link (112). The first link (102), the second link (104), the third link (106), and the base form a first parallel four-link mechanism. A first end of the fourth link (108) is hinged to a second end of the first link (102). A first end of the fifth link (110) is hinged to a second end of the second link (104). The sixth link (112) has a first end hinged to a second end of the fourth link (108), and a second end hinged to a second end of the fifth link (110). The fourth link (108), the fifth link (110), the sixth link (112), and the third link (106) form a second parallel four-link mechanism. A lifting table (114) is provided on the sixth link (112). The lifting device is provided on a vehicle body of the automated guided transport vehicle.
B: Disclosed is an integrated automatic unfolding/folding stair-climbing trolley suitcase, comprising a case body. The bottom of the case body is provided with universal wheels; a telescopic pull rod is provided on one side of the case body; the bottom of a slide plate is provided with a one-way wheel; an inner support is separately connected to the telescopic pull rod and the case body; limiting connecting rods on left and right sides are movably connected to the inner support by means of a first connecting rod and are movably connected to the slide plate by means of a second connecting rod; torsion spring connecting rods on the left and right sides are movably connected to the inner support by means of a third connecting rod and are movably connected to the slide plate by means of a fourth connecting rod; a double rocker mechanism is formed between the limiting connecting rods, the case body, the torsion spring connecting rods, and the slide plate; an elastic device has one end connected to the inner support and the other end connected to the fourth connecting rod; and a shock absorbing device is provided between the slide plate and the inner support. In the present invention, the slide plate can be automatic unfolded or folded to assist climbing stairs, and has shock absorbing and cushioning devices, thereby not only preventing damage to the case body itself or the fragile items therein, but also greatly reducing the noise and vibration produced during climbing stairs.
C: A novel fastening fixture for PCB soldering comprises a main rod (1). A lower end of the main rod (1) is rotatably connected to one end of a pressing rod (2). A middle portion of the pressing rod (2) is rotatably connected to one end of a first rotating member (3). A handle (16) is provided on the other end of the pressing rod (2). The other end of the first rotating member (3) is rotatably connected to a middle portion of a second connecting rod (8). A hole is provided at a position above the lowest end of the main rod (1). The main rod, the pressing rod, a first connecting rod, the second connecting rod, a latch rod, and multiple rotating pins are provided to form a novel holding rod connection device. The overall structure of the connection ensures a stable hold, and is simple and convenient to operate. When compared with a conventional fastening frame, the novel fastening fixture holds a PCB board more stably. A support protrusion is provided at a bottom end of a joint between the main rod and the pressing rod, such that a lever can be used to decrease required manpower, and improve strength and stability of the hold.
D: A baby stroller and collapsible mechanism thereof, and a method of collapsing and folding a baby stroller. The collapsible mechanism comprises two side frames and horizontal rods (70, 80, 25, 65). The side frames comprise front lower rods (10), back lower rods (20) and push rods. A front support rod (30) and a back support rod (40) are connected between the front lower rod (10) and the push rod to form a collapsible first 4-rod mechanism. A sequentially connected first connection rod (31) and second connection rod (32) pass between the front lower rod (10) and the back lower rod (20) to form a second 4-rod mechanism. One end of the first connection rod (31) is fixedly connected to or integrated with a lower end of the front support rods (30). The first 4-rod mechanism arranged in a folded state and a back lower rod (20) are stacked in layers at an upper side and a lower side of the front lower rod (10), respectively. An upper end of the back support rod (40) and a middle portion of the push rod are fixed and locked or unlocked and folded by a lock mechanism. The collapsible mechanism has a reasonable structure, has a decreased size after being folded, and is easy and effortless to operate.
Answer: B