Please select the most similar patent number from A, B, C and D. Which number is?
A height-adjustable crib, comprising a frame device (100) and a crib body (200) mounted on the frame device (100). The frame device (100) comprises two support side plates (110) oppositely arranged at an interval, a lifting mechanism (120), and a lifting control mechanism (130). A mounting position where the crib body (200) is positioned is defined between the two support side plates (110). The lifting mechanism (120) comprises a first support frame (121) and a second support frame (122) that intersect each other and are connected by means of a rotational shaft at the intersection. The support side plate (110) comprises a main body (113), a first connection part (111) and a second connection part (112) that are connected onto the main body (113) in relatively rotatable fashion, and an elastic member (114) connected between the first connection part (111) and the second connection part (112). The lifting control mechanism (130) comprises a locking assembly (131) mounted on the first connection part (111) and a locking engagement member (132) mounted on the second connection part (112). The crib is height-adjustable and is simple to operate.
A: A display screen and an angle-adjusting device (100) thereof. The angle-adjusting device (100) comprises a first base (110), a first support connecting rod (120), a first linkage gear (130), a second base (140), a second support connecting rod (150) and a second linkage gear (160). One end of the first support connecting rod (120) is rotatably connected to the first base (110). The first linkage gear (130) comprises a first connecting part (132) and a first gear meshing part (134) arranged on the first connecting part (132), with one end of the first connecting part (132) being rotatably connected to the first base (110). The second support connecting rod (150) is rotatably connected to the first support connecting rod (120), with one end of the second support connecting rod (150) being rotatably connected to the other end of the first connecting part (132), and the other end of the second support connecting rod (150) being rotatably connected to the second base (140). The second linkage gear (160) comprises a second connecting part (162) and a second gear meshing part (164) arranged on the second connecting part (162), the second connecting part (162) being rotatably connected to the other end of the first support connecting rod (120). An adjusting process for the display screen is convenient and rapid, and angle adjustment of the display screen can be operated with good flexibility and uniformity.
B: A spacing adjustment device (130) used for adjusting the spacing between a first connection portion (110) and a second connection portion (120) of a head massager comprises a surface cover assembly (140) arranged at the joint of the first connection portion (110) and the second connection portion (120) and a drive mechanism mounted on the surface cover assembly (140). The drive mechanism comprises a roller lock member (150) rotatably arranged on the surface cover assembly (140) and a first roller groove portion (160) arranged on the first connection portion (110). The roller lock member (150) is provided with a first roller column (151). The axis of the first roller column (151) is arranged in parallel with the axis of rotation of the roller lock member (150). The first roller groove portion (160) is provided with multiple first roller grooves (161) fitting the first roller column (151). When the roller lock member (150) is rotated, since the first roller column (151) is eccentric relative to the axis of rotation, the first roller column (151) can push the first roller groove (161), to drive the first connection portion (110) to move relative to the surface cover assembly (140), so as to adjust the distance between the first connection portion (110) and the second connection portion (120), thereby eliminating the defects of the adjustment mechanisms in the prior art such as the difficulty in adjustment and the complexity in structure. The structure is simple and reliable, and the operation is convenient.
C: An infant bed, comprising a bed body (10) and two supporting units symmetrically provided on the bed body (10). The supporting units comprise lifting/lowering components (30) and support frame components (20). The lifting/lowering components (30) comprise hollow fixing bases (31) provided on the support frame components (20) and a lifting/lowering mechanism (32). The fixing bases (31) are provided on the surface thereof facing the bed body (10) with multiple vertically arranged engaging holes (311). The lifting mechanism (32) comprises handles (321), hollow housings (322), traction wires (323), first springs (324), traction elements (325) second springs (326), and engaging fittings (327). The traction wires (323) are connected between the handles (321) and the traction elements (325). The first springs (324) are sleeved on the end of the traction wires (323) in proximity to the traction elements (325) and are abutted at either end between the traction elements (325) and the housings (322). The traction elements (325) are provided with first inclined surfaces (3251) in the direction of the traction wires (323). The housings (322) are provided with first through holes (3221). The engaging fittings (327) partially protrude the first through holes (3221) via the second springs (326) and are engaged with the engaging holes (311), and, the engaging fittings (327) are provided with second inclined surfaces matching the first inclined surfaces (3251).
D: Disclosed are an arc adjustable mounting frame (10), a display structure and a display screen. The arc adjustable mounting frame (10) comprises a first support (110), a second support (120) and a connecting member (130); the first support (110) comprises a first supporting post (111) and a first connecting plate (112), the first connecting plate (112) is provided on the first supporting post (111), and the first connecting plate (112) is provided with a plurality of first connecting holes (113); the second support (120) comprises a second support post (121) and a second connecting plate (122), the second connecting plate (122) is connected to the second support post (121), and the second connection plate (122) is provided with a plurality of second connecting holes (123); the first connecting plate (112) and the second connecting plate (122) at least partially overlap, at least one first connecting hole (113) corresponds to at least one second connecting hole (123), and the connecting member (130) penetrates through the first connecting hole (113) and the corresponding second connecting hole (112).
Answer: C