JPH0745520Y2 - Carrier - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foldable hand truck.

[0002]

2. Description of the Related Art Conventionally, there has been a technique in which a hand-pushed handle frame is erected vertically on a trolley and a loading platform is attached to the hand-pushed handle frame so as to be vertically movable.

[0003]

In the above prior art, the structure in which the platform is moved up and down by the hydraulic cylinder cannot easily reduce the weight and the manufacturing cost.
In the structure of raising and lowering the loading platform by the winch, there is a problem that the wire of the winch extends excessively when the loading platform descends and loosens, and the wire easily comes off from the predetermined suspension position. In the structure that raises and lowers the loading platform by rotating the shaft, rotating the screw shaft with the bevel gear requires a large rotational operation force, while rotating the screw shaft with the worm gear increases the operation amount, and When the bevel gear is provided on the upper end side of the screw shaft, there is a problem that the screw shaft moves downward due to the weight of the carrier and the meshing of the bevel gear is likely to be incomplete.

[0004]

DISCLOSURE OF THE INVENTION The present invention, however, provides a screw shaft having a ball screw in a carrier in which a hand-pushed handle frame is erected vertically on a trolley and a loading platform is movably mounted on the hand-pushed handle frame. The lower end is pivotally supported on the hand-push handle frame via a thrust bearing, the load platform is connected to the screw shaft via a nut body containing a transmission ball, and the lifting handle is attached to the upper end of the hand-push handle frame via a bevel gear case. A lifting handle is connected to the lifting output shaft via a lifting input shaft having a ratchet gear and a one-way clutch, and the screw shaft upper end is integrally rotatable with the lower end of the lifting output shaft projecting below the bevel gear case. It is connected in the vertical direction so that it can be moved freely.Connect the nut body of the loading platform to the screw shaft using a ball screw and transmission ball. Therefore, the operating force required to rotate the screw shaft can be reduced to facilitate the rotational drive by the bevel gear, which reduces the weight and manufacturing cost compared to the conventional hydraulic cylinder structure, and is more reliable than the conventional winch structure. It is possible to improve safety by raising and lowering operation, reduce the operation force compared to the conventional bevel gear and screw shaft structure, and easily reduce the operation amount compared to the conventional worm gear and screw shaft structure. The bevel gear case support structure can be simplified and the meshing of the bevel gear can be maintained easily because the force that moves the screw shaft downward due to the weight of the cargo is prevented from being transmitted to the lifting output shaft. It is possible to easily prevent the damage and the idling operation due to, and to handle safely.

[0005]

Embodiments of the present invention will be described in detail below with reference to the drawings. 1 is a sectional view of the screw shaft portion, FIG. 2 is a side view of the whole,
3 is a plan view of the same, FIG. 4 is a front view of FIG. 4, and FIG. 5 is an explanatory view of folding. The dolly (3) has front wheels (1) (1) and rear wheels (2) (2), and a pipe made of pipe. A gate-shaped hand-pushed handle frame (4), a lift frame (5) provided on both masts of the handle frame (4) so as to be able to move up and down, a table-shaped bed (6) attached to the lift frame (5), and the handle A screw shaft (7) provided substantially parallel to the middle of both mast parts of the frame (4), a bevel gear case (8) fixed to the central portion of the handle frame (4), and a lifting / lowering provided on the bevel gear case (8). With the handle (9), as shown in FIG. 2, the handle frame (4) is erected on the carriage (3) to elevate and lower the cargo bed (6) and manually move it, and as shown in FIG. (3) Handle frame (4 And bed (6) substantially in parallel are configured so folded by superposition.

Further, as shown in FIGS. 1 and 6 to 8,
The platform (6) is rotatably connected to the lift frame (5) through the long hole (10) and the bolt (11), and the lift frame (5) is connected to the handle frame (4) by the front and rear guide wheels (12) (13). ), So that the loading platform (6) is orthogonal to or parallel to the handle frame (4). Also, a lifting input shaft (14) for fixing the handle (9), and a bevel gear (15) (1
The bevel gear case (8) is provided with a lifting output shaft (17) that is connected to the input shaft (14) via the input shaft (6), and the ratchet gear (19) that is locked to the ratchet pawl (18) is connected to the input shaft (14). Engage via directional clutch (20). Further, the bearing stand (21) of the handle frame (4)
The lower end of the screw shaft (7) is rotatably supported by the thrust bearing (22), and the nut body (25) is screwed to the ball screw (23) in the middle of the screw shaft (7) through the transmission ball (24).
The nut body (25) is fixed to the lift frame (5), and the loading platform (6) is connected to the screw shaft (7) via the nut body (25). Also, the bevel gear case (8)
The key (2
6) via which the upper end of the screw shaft (7) is integrally rotatably connected so that it can move vertically toward and away from the load shaft (6).
The rotation of the screw shaft (7) due to its own weight lowering operation is blocked by the one-way clutch (20) and the ratchet gear (19), and the weight of the load carrier (6) is received only by the lower end side of the screw shaft (7), The weight is applied to the base of the handle frame (4) via the bearing stand (21).

Further, as shown in FIGS. 6, 9 and 10,
A fulcrum plate (27) (2) is attached to the lower end of the handle frame (4).
8) is integrally fixed, and the fulcrum plates (27) and (28) are connected to the carriage (3) through the fulcrum shaft (29), and the fulcrum shaft (2
9) The handle frame (4) is mounted on the carriage (3) so that it can be raised and lowered, and the tail plate (3) at the rear end of the carriage (3) is mounted.
0) is provided with a locking shaft (32) through a long hole (31), and a notch (33) and a hook (34) for engaging the locking shaft (32) are provided on a fulcrum plate (27). Then, as shown in FIG. 6, when the handle frame (4) is erected, the spring (35) is
To engage the locking shaft (32) with the notch (33),
The hook (34) is engaged with the locking shaft (32) to vertically fix the handle frame (4). On the other hand, as shown in FIG.
Remove the hook (34) from the notch (33) to the locking shaft (3
When the handle frame (4) is laid down, the lift frame (5) comes into contact with the upper surface of the carriage (3),
The handle frame (4) and the loading platform (6) are supported substantially parallel to the upper surface of the carriage (3), and the edge of the fulcrum plate (27) contacts the locking shaft (32), so that the fulcrum plate (27) and The handle frame (4) is prevented from standing up and the handle shaft (4) is lifted by moving the locking shaft (32) away from the fulcrum plate (27) to lift the handle frame (4) as shown in FIG. It is constructed so that it stands upright, and the loading platform (6) is orthogonal to the handle frame (4) and is supported substantially horizontally.

[0008]

As is apparent from the above embodiments, according to the present invention, the trolley (3) is provided with the hand-pushing handle frame (4) so as to be erected up and down, and the pallet (6) is mounted on the hand-pushing handle frame (4). In a transportation vehicle in which a ball is mounted up and down, a lower end of a screw shaft (7) having a ball screw (23) is pivotally supported by a hand-pushed handle frame (4) through a thrust bearing (22), and a transmission ball (24) is built therein. Nut body (25)
The load platform (6) is connected to the screw shaft (7) via the screw shaft (7), and the lifting handle (9) is provided on the upper end side of the hand handle frame (4) via the bevel gear case (8), and the ratchet gear (19) and Lower end of the lifting output shaft (17), which connects the lifting handle (9) to the lifting output shaft (17) via the lifting input shaft (14) having the one-way clutch (20) and projects below the bevel gear case (8). The upper end of the screw shaft (7) is integrally rotatably connected to the screw shaft (7) in a vertically movable manner. The ball screw (23) and the transmission ball (24) are used to attach the load shaft (7) to the screw shaft (7). Since the nut body (25) of 6) is connected, the operation force required for rotating the screw shaft (7) is reduced to reduce the bevel gear (15) (16).
The rotary drive can be easily performed, and the weight and manufacturing cost are reduced compared with the conventional hydraulic cylinder structure, and the safety is improved by the reliable lifting operation compared with the conventional winch structure. Also, the conventional bevel gear and screw shaft structure. It is possible to reduce the operating force in comparison with the conventional worm gear and the operation amount in comparison with the conventional worm gear and screw shaft structure, and to receive the weight of the load carrier (6) only on the lower end side of the screw shaft (7). ) Since the force for moving the screw shaft (7) downward due to the weight is prevented from being transmitted to the lifting output shaft (17), the support structure of the bevel gear case (8) is simplified and the meshing of the bevel gears (15) and (16) is maintained. Can be done easily,
The bevel gears (15) and (16) can be easily prevented from being damaged due to incomplete meshing and idling, and can be handled safely.

[Brief description of drawings]

FIG. 1 is a sectional view of a screw shaft portion.

FIG. 2 is an overall side view.

FIG. 3 is a plan view of the same.

FIG. 4 is a front view of the same.

FIG. 5 is an explanatory view of folding.

FIG. 6 is an enlarged side view.

FIG. 7 is a plan view of a push handle frame portion.

FIG. 8 is a rear view of the same.

FIG. 9 is an enlarged explanatory view of folding.

FIG. 10 is a plan view of the rear part of the bogie.

[Explanation of symbols]

 (3) Trolley (4) Handwheel frame (6) Loading platform (7) Screw shaft (8) Bevel gear case (9) Lift handle (14) Lift input shaft (17) Lift output shaft (19) Ratchet gear (20) One-way clutch (22) Thrust bearing (23) Ball screw (24) Transmission ball (25) Nut body

Claims (1)

[Scope of utility model registration request] 1. In a transport vehicle in which a hand-pushed handle frame is erected vertically on a dolly and a loading platform is mounted on the hand-pushed handle frame so as to be able to move up and down, a lower end of a screw shaft having a ball screw is provided with a thrust bearing on the hand-pushed handle frame. It is pivotally supported via a nut, and the load shaft is connected to the screw shaft via a nut body containing a transmission ball, and an elevating handle is provided on the upper end side of the hand handle frame via a bevel gear case, and a ratchet gear and a one-way clutch are provided. The elevating handle is connected to the elevating output shaft via the elevating input shaft, and the screw shaft upper end is integrally rotatably connected to the lower end of the elevating output shaft projecting below the bevel gear case so as to be vertically separable. A carrier that is characterized by that.