Lifter device

Abstract

The present invention provides a lifting device that allows a loading platform loaded with heavy objects to be easily raised to a predetermined lifting height by human power. [Solution] The lifter device 1 comprises a frame 2, a slider 22 attached to a support column frame 20, a loading platform 3 with a stopper 30 on its underside, and a first lifter mechanism 4. The first lifter mechanism 4 comprises a pair of first lever arms 41, a first hinge joint 42 having a first body 421 connected to the ends of the pair of first lever arms 41 and a first head 420 that can rotate up and down, a first connecting arm 43 connecting the first hinge joint 42, and a pair of first push-up arms 44 connected to the first connecting arm 43 at approximately a right angle, with their tips attached to the stopper 30 on the loading platform 3. The mechanism is configured such that when the first head 420 of the first hinge joint 42 rotates 90 degrees downward and comes into contact with the first body 421, the loading platform 3 is locked.

Description

Technical Field

[0001] This application relates to a lifter device used when lifting heavy objects.

Background Art

[0002] A lifter device is a device used when lifting heavy objects in a factory. As lifter devices, there are a hand lifter (for example, Patent Document 1) that raises and lowers a pallet on which a heavy object is mounted, a table lifter (for example, Patent Document 2) that raises and lowers a table using a pair of arms that cross in an X shape, and an air balancer (for example, Patent Document 3) that suspends a heavy object using a hook, etc. are known.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the case of a manually operated lifter device (for example, a hand lifter), when the lift height for lifting a heavy object increases, the work load when lifting the heavy object increases. If an electrically operated lifter device is used, the work load when lifting a heavy object can be reduced, but an electrically operated lifter device tends to be large, and equipment for supplying power to the lifter device is also required.

[0005] Therefore, in this application, a lifter device is provided that can easily raise a load platform on which a heavy object is mounted to a predetermined lift height by manual operation.

Means for Solving the Problems

[0006] The first invention that solves the above-mentioned frame problem comprises a frame consisting of at least four support frames and crossbar frames connecting adjacent support frames, a slider slidably attached to the support frames, a loading platform connected to the slider and having a stopper on its underside, and a lifter mechanism for raising the loading platform using the principle of leverage, comprising a pair of first lever arms pivotally supported on a first pivot roller attached to the frame, a first body connected to the ends of the pair of first lever arms and a first head having a first body that can rotate 180 degrees vertically relative to the first body. The lifter device is characterized by having a first lifter mechanism comprising a hinge joint, a first connecting arm that connects the first head portion of the first hinge joint provided on each of the pair of first lever arms, and a pair of first push-up arms that are connected to the first connecting arm at approximately a right angle and have their tips attached to the stopper of the loading platform, wherein when the loading platform is raised to a first lift height, the first head portion of the first hinge joint rotates 90 degrees downward and comes into contact with the first body portion, thereby locking the loading platform at the first lift height.

[0007] The second invention is characterized in that, in the lifter device described in the first invention, it comprises a first stay portion attached to the lower side of the first connecting arm and substantially perpendicular to the first connecting arm, and a first lock release lever having a first lever portion attached to the end of the first stay portion facing upward.

[0008] The third invention is an assist mechanism provided in the lifter device described in the first or second invention, wherein each of the two sliders is provided with a pulley, one end of a wire member is fixed to one of the support frames, the wire member is passed under each of the pulleys, and a weight is hung from the other end of the wire member that is not fixed to the support frame, so that the weight of the weight acts as a force to raise the loading platform.

[0009] The fourth invention relates to a lifter device described in the first or second invention, wherein the lifter mechanism comprises: a pair of second lever arms pivotally supported on a second pivot roller attached to the frame; a second hinge joint having a second body portion connected to the ends of the pair of second lever arms and a second head portion rotatable 180 degrees vertically relative to the second body portion; a second connecting arm connecting the second head portions of the second hinge joint provided on each of the pair of second lever arms; and a part provided substantially perpendicular to the second connecting arm and in contact with the underside of the loading platform. The present invention features a second lifter mechanism comprising a pair of second push-up arms each equipped with a contact roller at its tip, wherein when the loading platform is raised to a second lift height, the second head portion of the second hinge joint rotates 90 degrees downward to contact the second body portion, thereby locking the loading platform at the second lift height, and the first lifter mechanism being positioned opposite each other, wherein the loading platform raised by the second lifter mechanism to the second lift height is raised by the first lifter mechanism to the first lift height.

[0010] The fifth invention is a lifter device as described in the fourth invention, characterized in that it comprises a second stay portion attached to the lower side of the second connecting arm and substantially perpendicular to the second connecting arm, and a second lock release lever having a second lever portion attached to the end of the second stay portion facing upward.

[0011] The sixth invention is an assist mechanism provided in the lifter device described in the fourth invention, wherein each of the two sliders is provided with a pulley, one end of a wire member is fixed to one of the support frames, the wire member is passed under each of the pulleys, and a weight is hung from the other end of the wire member that is not fixed to the support frame, so that the weight of the weight acts as a force to raise the loading platform.

[0012] The seventh invention is an assist mechanism provided in the lifter device described in the fifth invention, wherein each of the two sliders is provided with a pulley, one end of a wire member is fixed to one of the support frames, the wire member is passed under each of the pulleys, and a weight is hung from the other end of the wire member that is not fixed to the support frame, so that the weight of the weight acts as a force to raise the loading platform. [Effects of the Invention]

[0013] The lifter device disclosed in this application, in order to solve the problems of this application, is equipped with a lifter mechanism that uses the principle of leverage to raise the platform to a predetermined lift height and lock the platform at the predetermined lift height. By using the principle of leverage to raise the platform to a predetermined lift height, the force required to manually raise a platform loaded with heavy objects to the predetermined lift height can be reduced. Furthermore, if the platform can be locked at the predetermined lift height, work can be performed even if the operator releases their hands from the lifter device. [Brief explanation of the drawing]

[0014] [Figure 1] A top view of the lifter device according to this embodiment. [Figure 2] Left side view of the lifter device according to this embodiment. [Figure 3] A diagram illustrating the support structure of a lifting device. [Figure 4] A diagram illustrating the loading platform of a lifting device. [Figure 5] A diagram illustrating the first lifter mechanism of the lifter device. [Figure 6] A diagram illustrating the first hinge joint. [Figure 7] A diagram illustrating the operation of the first lifter mechanism. [Figure 8] A diagram illustrating the state of the first head portion of the first hinge joint. [Figure 9] A diagram illustrating the mechanism that automatically locks the cargo bed. [Figure 10]A diagram for explaining the first unlocking lever included in the lifter device. [Figure 11] A diagram for explaining the mechanism for unlocking the loading platform. [Figure 12] A diagram for explaining the second lifter mechanism included in the lifter device. [Figure 13] A diagram for explaining the operation of the second lifter mechanism. [Figure 14] A diagram for explaining the assist mechanism included in the lifter device.

Embodiments for Carrying out the Invention

[0015] Hereinafter, embodiments of the invention disclosed in the present application, the invention of the present application, will be described. This embodiment is for facilitating the understanding of the invention of the present application, and the invention of the present application is not limited to this embodiment. Also, unless otherwise specified, the drawings are schematic diagrams drawn for facilitating the understanding of the invention of the present application.

[0016] First, referring to FIGS. 1 and 2, the overall configuration of the lifter device 1 according to this embodiment will be described. FIG. 1 is a top view of the lifter device 1 according to this embodiment. FIG. 2 is a left side view of the lifter device 1 according to this embodiment.

[0017] The lifter device 1 according to this embodiment is a device that uses the principle of leverage to raise a loading platform 3 on which heavy objects are carried to a predetermined lift height. As shown in Figures 1 and 2, the lifter device 1 comprises a frame 2 that is roughly rectangular in shape, formed by four support frames 20 and crossbar frames 21 connecting adjacent support frames 20, a slider 22 that is mounted on the support frames 20 so as to be able to slide up and down, a loading platform 3 that is connected to the slider 22 and has a stopper 30 on its underside, and a lifter mechanism that uses the principle of leverage to raise the loading platform 3, comprising a first lifter mechanism 4 and a second lifter mechanism 5. Furthermore, the lifter device 1 is equipped with an assist mechanism 6 that assists in the work of raising loads using the lifter device 1. In the lifter device 1 according to this embodiment, casters 200 are provided at the lower end of each of the four support frames 20 in order to make the lifter device 1 movable.

[0018] In this embodiment, the lifter device 1 is equipped with two lifter mechanisms, but the lifter device 1 may be equipped with only one lifter mechanism. The lifter device 1 can also be configured to raise the cargo bed 3 from its initial height to a predetermined height using only the first lifter mechanism 4. However, when raising the cargo bed 3 using the principle of leverage, the distance that the lever's point of force must move increases as the height to which the cargo bed 3 loaded with heavy objects is raised increases.

[0019] Therefore, in this embodiment, the lifter device 1 is configured to raise the loading platform 3 to a predetermined lift height in two stages. The second lifter mechanism 5 of the lifter device 1 is a lifter mechanism used for the first stage of lifting, which is performed by the worker using their feet, and the first lifter mechanism 4 of the lifter device 1 is a lifter mechanism used for the second stage of lifting, which is performed by the worker using their hands. As shown in Figures 1 and 2, the second lifter mechanism 5 is positioned opposite the first lifter mechanism 4 in the lifter device 1, and the lifter device 1 is configured so that the first lifter mechanism 4 and the second lifter mechanism 5 are interlocked. Specifically, as shown in Figure 2, when the worker performs the first lift operation with their feet, the second lifter mechanism 5 raises the loading platform 3 from its initial height to the first lift height. When the worker performs the second lift operation with their hands, the first lifter mechanism 4 raises the loading platform 3, which has been raised by the second lifter mechanism 5, from the first lift height to the second lift height. The first lift height becomes the second lift height at which the second lifter mechanism 5 raises the loading platform. The second lift height becomes the first lift height at which the first lifter mechanism 4 raises the loading platform.

[0020] Figure 3 is a diagram illustrating the frame 2 of the lifter device 1. The frame 2 of the lifter device 1 is a structure that supports the first lifter mechanism 4 and the second lifter mechanism 5, etc. As shown in Figure 3, the frame 2 of the lifter device 1 is roughly a rectangular parallelepiped formed by four support frames 20 and horizontal frame 21 that connects adjacent support frames 20.

[0021] As shown in Figure 3, the length of the pair of support frames 20 (support frame 20a and support frame 20b) located on the side where the worker performs the second-stage lift operation by hand (second-stage work side) is longer than the length of the pair of support frames 20 (support frame 20c and support frame 20d) located on the side where the worker performs the first-stage lift operation by leg (first-stage work side).

[0022] The lifting mechanism of the lifter device 1 is equipped with a function that automatically locks the platform 3 to prevent it from descending once it has been raised to a predetermined lift height, even though it is operated manually. As will be explained in more detail later, the platform 3, once raised to a predetermined lift height, is locked using the frame 2. For this reason, the frame 2 of the lifter device 1 needs to be rigid. In this embodiment, the frame 2 of the lifter device 1 is made into a roughly rectangular parallelepiped structure by using four support frames 20 and crossbar frames 21 that connect adjacent support frames 20, thereby increasing the rigidity of the frame 2 of the lifter device 1. As shown in Figure 3, the lower sides of adjacent support frames 20a and 20b are connected by horizontal frame 21a, the lower sides of adjacent support frames 20b and 20c are connected by horizontal frame 21b, the lower sides of adjacent support frames 20c and 20d are connected by horizontal frame 21c, and the lower sides of adjacent support frames 20d and 20a are connected by horizontal frame 21d. In addition, the upper ends of support frames 20a and 20b are connected by horizontal frame 21e, and the upper ends of support frames 20c and 20d are connected by horizontal frame 21f.

[0023] Each of the four support columns 20 of the frame 2 is provided with a slider 22 that slides the support column 20 up and down. The mechanism of the slider 22 is arbitrary. For example, a linear slider that slides by clamping the support column 20 with bearing rollers can be used as the slider 22.

[0024] In the lifter device 1 according to this embodiment, sliders 22 provided on each of the four support column frames 20 of the frame 2 are attached to the loading platform 3. In this embodiment, sliders 22b and 22c are connected by the loading platform 3, and sliders 22a and 22d are connected by the loading platform 3. With this configuration, the movement of the four sliders 22 in the lifter device 1 according to this embodiment is synchronized.

[0025] In this embodiment, a pivot roller used as a fulcrum for the lever is attached to the frame 2 of the lifter device 1. A second pivot roller 50, which serves as the fulcrum for the second lifter mechanism 5, is attached to the frame 2 of the support column frames 20c and 20d, which are located on the first lift operation side, using a second pivot bracket 24. A first pivot roller 40, which serves as the fulcrum for the first lifter mechanism 4, is attached to the frame 2 of the support column frames 20a and 20b, which are located on the second lift operation side, using a first pivot bracket 23.

[0026] Figure 4 is a diagram illustrating the loading platform 3 provided by the lifter device 1. Figure 4(a) shows the loading platform 3. Figure 4(b) shows the first plate-shaped bracket 33 provided on the loading platform 3. Figure 4(c) shows the second plate-shaped bracket 34 provided on the loading platform 3.

[0027] The platform 3 of the lifter device 1 is attached to the frame 2 using a platform frame 31 to connect sliders 22a and 22d, and sliders 22b and 22c, as shown in Figure 4(a). The platform 3 of the lifter device 1 includes a platform frame 31a that connects sliders 22a and 22d, and a platform frame 31b that connects sliders 22b and 22c. Furthermore, the platform 3 includes a pair of roller conveyors 32 that connect the platform frames 31a and 31b. In addition, the platform 3 of the lifter device 1 includes a first plate-shaped bracket 33 and a second plate-shaped bracket 34 between the pair of roller conveyors 32 that connect the platform frames 31a and 31b. The first plate-shaped bracket 33 is a component used to attach the stopper 30. The second plate-shaped bracket 34 is a component used to attach the contact plate 340, which contacts the tip of the second lifter mechanism 5.

[0028] Figure 4(b) shows the first plate-shaped bracket 33. A pair of stopper brackets 330 for attaching the stopper 30 are provided on the back surface of the first plate-shaped bracket 33. The stopper 30 is attached to the back surface of the loading platform 3 using the pair of stopper brackets 330. As shown in Figure 4(b), the stopper 30 according to this embodiment has a cylindrical shape that extends in the left-right direction of the lifter device 1. Both sides of the stopper 30 are fixed to the stopper brackets 330. Rotary connectors 300 for attaching the tip of the first lifter mechanism 4 are attached to both sides of the stopper 30 that are outside the stopper brackets 330. The rotary connectors 300 are connectors configured to rotate smoothly by incorporating bearings. Figure 4(c) shows the second plate-shaped bracket 34. As shown in Figure 4(c), the second plate-shaped bracket 34 is roughly L-shaped, and a plate-shaped contact plate 340 is provided at the lower end of the second plate-shaped bracket 34 for contacting the tip of the second lifter mechanism 5.

[0029] Figure 5 is a diagram illustrating the first lifter mechanism 4 provided in the lifter device 1. In this embodiment, the first lifter mechanism 4 is a mechanism that uses the principle of levers to raise the loading platform 3 loaded with heavy objects from the first lift height to the second lift height. The first lifter mechanism 4 includes a pair of first lever arms 41 pivotally supported on a first pivot roller 40 which serves as the fulcrum of the levers, a first hinge joint 42 having a first body portion 421 connected to the ends of the pair of first lever arms 41 and a first head portion 420 that can rotate 180 degrees vertically, a first connecting arm 43 connecting the first hinge joint 42, and a pair of first push-up arms 44 connected to the first connecting arm 43 at approximately a right angle, with their tips attached to the stopper 30 of the loading platform 3. In the first lifter mechanism 4, the pair of first lever arms 41 function as the levers of the first lifter mechanism 4. In the first lifter mechanism 4, the first hinge joint 42, the first connecting arm 43, and the pair of first push-up arms 44 function as a link mechanism that transmits the lever force from the pair of first lever arms 41 to the loading platform 3.

[0030] The pair of first lever arms 41 provided in the first lifter mechanism 4 are rod-shaped members. The pair of first lever arms 41 are connected from the first connecting frame 47a to the first connecting frame 47f. The middle of the pair of first lever arms 41 is pivotally supported by the first pivot roller 40, which serves as the fulcrum of the pair of first lever arms 41, and the pair of first lever arms 41 functions as a lever. The method of pivotally supporting the pair of first lever arms 41 on the first pivot roller 40 is arbitrary, but in this embodiment, the pair of first lever arms 41 are pivotally supported on the first pivot roller 40 using a rotary connector 400.

[0031] A pair of first lever arms 41, which are the point of force application of the lever, are provided with handles 45 that are operated by the worker. The first lifter mechanism 4 is a lifter mechanism used for the second stage of lifting, which is performed manually by the worker. For this reason, in this embodiment, the handles 45 provided on the first lifter mechanism 4 are made into a zigzag shape that extends upward, giving the handles 45 height. This is to make the height of the handles 45 provided on the first lifter mechanism 4 a height that is easy for the worker performing the second stage of lifting to grasp with their hands, so that the worker can perform the second stage of lifting without having to squat down.

[0032] Figure 6 is a diagram illustrating the first hinge joint 42. Figure 6(a) is a left side view of the first hinge joint 42. Figure 6(b) is a top view of the first hinge joint 42. As shown in Figure 5, the first hinge joint 42 is provided at the end of a pair of first lever arms 41 that are on the lever's point of action side. As shown in Figure 6, the first hinge joint 42 consists of a first head portion 420 and a first body portion 421. The first head portion 420 of the first hinge joint 42 is a member that rotates up and down, and the first body portion 421 of the first hinge joint 42 is a member that connects to the pair of first lever arms 41. As shown in Figure 5 and other figures, the first head portion 420 is fixed to the first connecting arm 43, and the two first head portions 420 are connected via the first connecting arm 43.

[0033] As shown in Figure 6(b), the first head portion 420 is pivotally supported on the first body portion 421 using the first hinge shaft 422. As shown in Figure 6(a), the first head portion 420 can rotate 180 degrees in a fan shape around the first hinge shaft 422. As shown in Figure 6(a), in this embodiment, the state in which the pair of first lever arms 41 and the first head portion 420 are aligned in a straight line is defined as 0 degrees. When the first head portion 420 rotates 90 degrees upward around the first hinge shaft 422, the first head portion 420 comes into contact with the first body portion 421, and therefore the first head portion 420 cannot rotate upward beyond 90 degrees. Furthermore, when the first head portion 420 rotates 90 degrees downward around the first hinge axis 422, the first head portion 420 comes into contact with the first body portion 421, so the first head portion 420 cannot rotate downward more than 90 degrees.

[0034] Returning to the explanation of Figure 5, the first connecting arm 43 is a member that connects the first head portion 420 of the first hinge joint 42 provided on one of the pair of first lever arms 41 to the first head portion 420 of the first hinge joint 42 provided on the other. In this embodiment, the first connecting arm 43 is cylindrical. A pair of first push-up arms 44 are connected at approximately right angles to both sides of the cylindrical first connecting arm 43. The ends of the pair of first push-up arms 44, that is, the ends not connected to the first connecting arm 43, are connected to a rotary connector 300 provided on a stopper 30 provided on the underside of the loading platform 3. In other words, the pair of first push-up arms 44 are rotatable relative to the stopper 30.

[0035] Figure 7 is a diagram illustrating the operation of the first lifter mechanism 4. Figure 8 is a diagram illustrating the state of the first head portion 420 of the first hinge joint 42.

[0036] The first lifter mechanism 4 is a mechanism that raises the loading platform 3 from the first lift height to the second lift height. The mechanism that raises the loading platform 3 to the first lift height is the second lifter mechanism 5, which will be described in detail later. The tips of the pair of first push-up arms 44 provided by the first lifter mechanism 4 are connected to a stopper 30 provided on the underside of the loading platform 3 via a rotary connector 300. Therefore, when the second lifter mechanism 5 raises the loading platform 3 from its initial height to the first lift height, the tips of the pair of first push-up arms 44 provided by the first lifter mechanism 4 also rise to a position corresponding to the first lift height. The upward movement of the tips of the pair of first push-up arms 44 is transmitted to a pair of lever frames via a first connecting arm 43 and a first hinge joint 42. Following the principle of leverage, when the first hinge joint 42, located at one end of a pair of lever frames, rises, the handle 45, located at the opposite end, rotates downward.

[0037] In the first lifter mechanism 4, the lift height of the first stage becomes the starting height of the lifting operation. As shown in Figure 8(b), at the starting height of the lifting operation, the angle of the first head portion 420 of the first hinge joint 42 is 0 degrees. The first lifter mechanism 4 is designed so that at the starting height of the lifting operation, the angle of the first head portion 420 of the first hinge joint 42 is 0 degrees. Since the initial height of the loading platform 3 is lower than the lift height of the first stage, as shown in Figure 8(a), when the loading platform 3 is at the initial height, the first head portion 420 of the first hinge joint 42 is rotated upwards.

[0038] Since the pair of first lever arms 41 function as levers with the first pivot roller 40 as the pivot point, when the handles 45 of the pair of first lever arms 41 are pushed down when they are at the starting height for the lifting operation, the ends of the pair of first lever arms 41 opposite the handles 45 rise. A first connecting arm 43 is fixed to the first head portion 420 of the first hinge joint 42 provided at the ends of the pair of first lever arms 41 opposite the handles 45, and a pair of first push-up arms 44 are fixed to the first connecting arm 43 at approximately a right angle. Therefore, when the ends of the pair of first lever arms 41 opposite the handles 45 rise, the pair of first push-up arms 44 also rise. Since the pair of first push-up arms 44 are connected to a stopper 30 provided on the underside of the loading platform 3, the loading platform 3 also rises. On the other hand, a first hinge joint 42, which can rotate vertically, is provided at the ends of a pair of first lever arms 41 on the opposite side of the handle 45. Therefore, in conjunction with the upward movement of the end of the first lever arm to which the first hinge joint 42 is provided, the first head portion 420 of the first hinge joint 42 rotates downward. As shown in Figure 8(c), when the first head portion 420 of the first hinge joint 42 rotates downward by 90 degrees, the first head portion 420 comes into contact with the first body portion 421 and can no longer rotate downward. Since the first head portion 420 of the first hinge joint 42 rotates downward in conjunction with the upward movement of the end of the first lever arm to which the first hinge joint 42 is provided, when the first head portion 420 can no longer rotate downward, the pair of first push-up arms 44 connected to the first head portion 420 also cannot be raised. In the first lifter mechanism 4 according to this embodiment, since the pair of first push-up arms 44 are fixed to the stopper 30 of the loading platform 3, in the first lifter mechanism 4 according to this embodiment, the height of the loading platform 3 when the first head portion 420 of the first hinge joint 42 rotates 90 degrees downward becomes the maximum height (second lift height) to which the loading platform 3 can be raised using the first lifter mechanism 4.

[0039] Figure 9 illustrates the mechanism by which the cargo bed 3 is automatically locked. When the first head portion 420 of the first hinge joint 42 rotates 90 degrees downward and comes into contact with the first body portion 421, the first head portion 420 of the first hinge joint 42 comes into contact with the tips of the pair of first lever arms 41 in a state where it cannot rotate downward. Therefore, when the first head portion 420 of the first hinge joint 42 rotates 90 degrees downward and comes into contact with the first body portion 421, the pair of first lever arms 41, the first hinge joint 42, the first connecting rod, and the pair of first push-up arms 44 become one unit.

[0040] When the first head portion 420 of the first hinge joint 42 rotates 90 degrees downward and pushes the handle 45 downward until the first head portion 420 contacts the first body portion 421, and then the operator releases their hand from the handle 45, in Figure 9, the integrated pair of first lever arms 41 etc. attempt to rotate counterclockwise. The force F that causes the integrated pair of first lever arms 41 etc. to rotate counterclockwise can be decomposed into a downward force F1 and a force F2 directed toward the first work stage. That is, the loading platform 3, to which the tips of the pair of first push-up arms 44 are attached to the underside, attempts to move downward due to the downward force F1 and also attempts to move toward the first work stage due to the force F2 directed toward the first work stage. However, since the slider 22 to which the loading platform 3 is attached is attached to the support frame 20 of the frame 2, the loading platform 3 cannot move toward the first work stage. Furthermore, the force that causes the integrated pair of first lever arms 41 to rotate counterclockwise is also applied to the first pivot roller 40. However, since the first pivot roller 40 is also attached to the frame 2, the force F that causes the object to rotate counterclockwise prevents the first pivot roller 40 from moving. Therefore, when the platform 3 is raised until the first head portion 420 of the first hinge joint 42 is rotated 90 degrees downward, the platform 3 cannot be lowered. In other words, when the platform 3 is raised until the first head portion 420 of the first hinge joint 42 is rotated 90 degrees downward, the platform 3 cannot be raised or lowered, and the platform 3 is locked at the height at which the first head portion 420 of the first hinge joint 42 is rotated 90 degrees downward.

[0041] When the loading platform 3 is raised until the first head portion 420 of the first hinge joint 42 rotates 90 degrees downward, the loading platform 3 becomes locked, so a mechanism is needed to release the lock on the loading platform 3. Therefore, the first lifter mechanism 4 of the lifter device 1 according to this embodiment is equipped with a first lock release lever 46 used to release the lock on the loading platform 3.

[0042] Figure 10 is a diagram illustrating the first lock release lever 46 provided by the lifter device 1. Figure 11 is a diagram illustrating the mechanism for releasing the lock on the loading platform 3. As shown in Figures 10 and 11, the first lock release lever 46 has a first stay portion 461 attached to the lower side of the first connecting arm 43 and at approximately a right angle to the first connecting arm 43, and a first lever portion 460 attached to the end of the first stay portion 461 facing upward. In the first lock release lever 46, the first lever portion 460 is the component operated by the worker when releasing the lock on the loading platform 3.

[0043] The first stay portion 461 of the first lock release lever 46 has a roughly L-shape when viewed from the side. The vertical bar 4610 of the roughly L-shaped first stay portion 461 is shorter than the horizontal bar 4611. A first lever portion 460 is provided at the end of the horizontal bar 4611 of the first stay portion 461, protruding upwards, and the vertical bar 4610 of the first stay portion 461 is attached to the lower side of the first connecting arm 43 and at roughly a right angle to the first connecting arm 43.

[0044] Figure 11(a) shows the state of the first release lever 46 at the lift start position. Figure 11(b) shows the state of the first release lever 46 when the loading platform 3 is locked. Figure 11(c) shows the state when the loading platform 3 has been unlocked using the first release lever 46.

[0045] As shown in Figure 11(a), when the platform 3 is at the first lift height, the horizontal bar 4611 of the first stay portion 461 is approximately parallel to the pair of first lever arms 41. Since the vertical bar 4610 of the first stay portion 461 is attached to the first connecting arm 43, when the platform 3 is raised from the first lift height to the second lift height, the first release lever 46 also rotates in accordance with the first head portion 420 of the first hinge joint 42. As shown in Figure 11(b), when the platform 3 is at the second lift height, the vertical bar 4610 of the first release lever 46 is approximately parallel to the pair of first lever arms 41, and the horizontal bar 4611 of the first release lever 46 is perpendicular to the pair of first lever arms 41. In the state shown in Figure 11(b), when the first lever portion 460 of the first lock release lever 46 is pushed downward, the first connecting arm 43, which is connected to the vertical bar 4610 of the first lock release lever 46, moves upward, and in accordance with the movement of the first connecting arm 43, the first head portion 420 of the first hinge joint 42 rotates upward. As the first head portion 420 of the first hinge joint 42 rotates upward, it is no longer rotated 90 degrees downward, and the lock on the loading platform 3 is released. Once the lock on the loading platform 3 is released, the handle 45 of the first lifter mechanism 4 can be lifted upward, and when the handle 45 of the first lifter mechanism 4 is lifted upward, the first head portion 420 of the first hinge joint 42 rotates upward, allowing the loading platform 3 to be lowered to the first lift height.

[0046] Figure 12 is a diagram illustrating the second lifter mechanism 5 provided in the lifter device 1. In this embodiment, the second lifter mechanism 5 is a mechanism that uses the principle of levers to raise the loading platform 3 from its initial height to the first lift height. The basic structure of the second lifter mechanism 5 is the same as that of the first lifter mechanism 4. The second lifter mechanism 5 includes a pair of second lever arms 51 pivotally supported on a second pivot roller 50 which serves as the fulcrum of the lever, a second hinge joint 52 having a second body portion 521 that connects to the ends of the pair of second lever arms 51 and a second head portion 520 that can rotate 180 degrees vertically, a second connecting arm 53 that connects the second hinge joint 52, and a pair of second push-up arms 54 that are connected to the second connecting arm 53 at approximately a right angle and have their tips attached to the stopper 30 of the loading platform 3. In the second lifter mechanism 5, a pair of second lever arms 51 function as levers for the second lifter mechanism 5. In the second lifter mechanism 5, the second hinge joint 52, the second connecting arm 53, and the pair of second push-up arms 54 function as linkage mechanisms that transmit the lever force from the pair of second lever arms 51 to the loading platform 3. In the first lifter mechanism 4, the tips of the pair of first push-up arms 44 were connected to a stopper 30 provided on the underside of the loading platform 3, but in the second lifter mechanism 5, contact rollers 540 are attached to the tips of each of the pair of first push-up arms 44.

[0047] The pair of second lever arms 51 provided in the second lifter mechanism 5 are rod-shaped members. The pair of second lever arms 51 are connected from the second connecting frame 57a to the second connecting frame 57d. The middle of the pair of second lever arms 51 is pivotally supported by the second pivot roller 50, which serves as the fulcrum of the pair of second lever arms 51, and the pair of second lever arms 51 functions as a lever. The method of pivotally supporting the pair of second lever arms 51 on the second pivot roller 50 is arbitrary, but in this embodiment, the pair of second lever arms 51 are pivotally supported on the second pivot roller 50 using a rotary connector 500. In this embodiment, the width in the left-right direction of the pair of second lever arms 51 is made narrower than the width in the left-right direction of the pair of first lever arms 41. This is to prevent the pair of second lever arms 51 and the pair of first lever arms 41 from coming into contact.

[0048] A pedal 55, operated by an operator, is provided at the end of a pair of second lever arms 51, which are the point of force application of the lever. The second lifter mechanism 5 is a lifter mechanism used for the first stage of lifting, which is performed by the operator using their feet. For this reason, in this embodiment, the second lifter mechanism 5 is equipped with a foot-operated pedal 55, which is made up of second connecting frames 57a to 57c.

[0049] The second hinge joint 52 of the second lifter mechanism 5 is the same as the first hinge joint 42 of the first lifter mechanism 4, so a detailed explanation is omitted here. Similar to the first hinge joint 42 of the first lifter mechanism 4, the second hinge joint 52 of the second lifter mechanism 5 is also composed of a second head portion 520 and a second body portion 521. In the second hinge joint 52 of the second lifter mechanism 5, when the second head portion 520 rotates 90 degrees downward, the second head portion 520 comes into contact with the second body portion 521, and the second head portion 520 cannot rotate downward more than 90 degrees.

[0050] The second connecting arm 53 is a member that connects the second head portion 520 of the second hinge joint 52 provided on one of the pair of second lever arms 51 to the second head portion 520 of the second hinge joint 52 provided on the other. In this embodiment, the second connecting arm 53 is also cylindrical. A pair of second push-up arms 54 are connected at approximately right angles to both sides of the cylindrical second connecting arm 53. At the ends of the pair of second push-up arms 54, that is, the ends not connected to the second connecting arm 53, there are contact rollers 540 that come into contact with a contact plate 340 provided on the underside of the loading platform 3. In this embodiment, the contact rollers 540 are cylindrical. The contact rollers 540 are rotatably mounted on the ends of the pair of second push-up arms 54, and silicone rubber 5400 is wrapped around the portion that comes into contact with the contact plate 340.

[0051] Figure 13 is a diagram illustrating the operation of the second lifter mechanism 5. The second lifter mechanism 5 is a mechanism that raises the loading platform 3 from its initial height to the first lift height. In the second lifter mechanism 5, the initial height of the loading platform 3 becomes the starting height of the lift operation. In the second lifter mechanism 5, the second lifter mechanism 5 is designed so that the angle of the second head portion 520 of the second hinge joint 52 becomes 0 degrees at the starting height of the lift operation. Since the pair of second lever arms 51 function as levers using the second pivot roller 50, when the pedal 55 of the pair of second lever arms 51 is pushed down while the loading platform 3 is at its initial height, the end of the pair of second lever arms 51 on the opposite side of the pedal 55 rises. A second connecting arm 53 is fixed to the second head portion 520 of a second hinge joint 52, which is provided at the end of a pair of second lever arms 51 on the opposite side of the pedal 55, and a pair of second push-up arms 54 are fixed to the second connecting arm 53 at approximately a right angle. Therefore, when the end of the pair of second lever arms 51 on the opposite side of the pedal 55 rises, the pair of second push-up arms 54 also rises. The contact rollers 540 provided at the tips of the pair of second push-up arms 54 are in contact with the contact plate 340 on the underside of the loading platform 3, so the loading platform 3 also rises. On the other hand, a second hinge joint 52 that can rotate up and down is provided at the end of the pair of second lever arms 51 on the opposite side of the pedal 55. Therefore, in conjunction with the rising of the end of the pair of second lever arms 51 to which the second hinge joint 52 is provided, the second head portion 520 of the second hinge joint 52 rotates downward. When the second head portion 520 of the second hinge joint 52 rotates 90 degrees downward, the second head portion 520 comes into contact with the second body portion 521 and can no longer rotate downward. Since the second head portion 520 of the second hinge joint 52 rotates downward in conjunction with the upward movement of the ends of the pair of second lever arms 51 to which the second hinge joint 52 is provided, when the second head portion 520 can no longer rotate downward, the pair of second push-up arms 54 connected to the second head portion 520 cannot be raised. Therefore, in the second lifter mechanism 5 according to this embodiment, the height of the loading platform 3 when the second head portion 520 of the second hinge joint 52 rotates 90 degrees downward becomes the maximum height (first stage lift height) to which the loading platform 3 can be raised using the second lifter mechanism 5.However, in the second lifter mechanism 5 according to this embodiment, since the pair of second push-up arms 54 are not fixed to the stopper 30 of the loading platform 3, the loading platform 3 can be raised using the first lifter mechanism 4 even when the second head portion 520 of the second hinge joint 52 is rotated 90 degrees downward.

[0052] When the pair of second push-up arms 54 rise, the contact rollers 540 provided at the tips of the pair of second push-up arms 54 move toward the stopper 30 on the underside of the loading platform 3. The second lifter mechanism 5 according to this embodiment is designed so that when the second head portion 520 of the second hinge joint 52 rotates 90 degrees downward, the contact rollers 540 come into contact with the stopper 30 of the loading platform 3. Also, similar to the first lifter mechanism 4, when the second head portion 520 of the second hinge joint 52 rotates 90 degrees downward, the pair of second lever arms 51, the second hinge joint 52, the second connecting rod, and the pair of second push-up arms 54 become integrated, and the contact rollers 540 that are in contact with the stopper 30 of the loading platform 3 push the stopper 30 of the loading platform 3 toward the second work stage. However, since the loading platform 3 is attached to the support frame 20, the loading platform 3 cannot move toward the second work stage. Therefore, in the second lifter mechanism 5 as well, once the loading platform 3 is raised until the second head portion 520 of the second hinge joint 52 is rotated 90 degrees downward, the loading platform 3 cannot be lowered. Thus, once the loading platform 3 is raised until the second head portion 520 of the second hinge joint 52 is rotated 90 degrees downward, the loading platform 3 cannot be raised or lowered, and the loading platform 3 is locked at the height at which the second head portion 520 of the second hinge joint 52 is rotated 90 degrees downward.

[0053] As shown in Figure 12, the second lifter mechanism 5, like the first lifter mechanism 4, is also provided with a second lock release lever 56 for releasing the lock on the cargo bed 3. As shown in Figure 12, the second lock release lever 56, like the first lock release lever 46, has a second stay portion 561 attached to the lower side of the second connecting arm 53 and at approximately a right angle to the second connecting arm 53, and a second lever portion 560 attached to the end of the second stay portion 561 facing upward. The second lock release lever 56, like the first lock release lever 46, is a mechanism that releases the state in which the second head portion 520 of the second hinge joint 52 has been rotated 90 degrees downward.

[0054] Figure 14 is a diagram illustrating the assist mechanism 6 provided in the lifter device 1. The assist mechanism 6 is provided on both the left and right sides of the lifter device 1, but Figure 14 shows the assist mechanism 6 provided on the left side of the lifter device 1. As shown in Figures 2 and 14, the lifter device 1 according to this embodiment is equipped with an assist mechanism 6 that utilizes the weight of the counterweight 60 to reduce the force required to lower the handle 45 of the first lifter mechanism 4. This is because it is preferable to use less force to lift heavy objects.

[0055] As shown in Figure 14 and other figures, the assist mechanism 6 provided in the lifter device 1 according to this embodiment is configured to use a pulley 62 and a wire member 61 to cancel out the weight of the heavy object loaded onto the loading platform 3 by the weight of the counterweight 60. By providing the assist mechanism 6 in the lifter device 1 and canceling out the weight of the heavy object loaded onto the loading platform 3, the loading platform 3 loaded with heavy objects can be raised with the same force required to raise the loading platform 3 without any heavy objects, thereby reducing the burden when raising the loading platform 3.

[0056] In Figure 14, the weight 60 is slidably attached to the assist mechanism frame 63. Pulleys 62a and 62b, which guide the wire member 61, are attached to the upper end of the assist mechanism frame 63, pulley 62c is attached to the slider 22a, and pulley 62d is attached to the slider 22d. One end of the wire member 61 is fixed to the upper end of the weight 60, and the other end, which is not attached to the weight 60, is passed over the pulleys 62a and 62b attached to the assist mechanism frame 63, and then under the pulleys 62c attached to the slider 22a and pulley 62d attached to the slider 22d, and fixed to the upper side of the support frame 20c. In this configuration, pulleys 62a and 62b attached to the assist mechanism frame 63 function as a single fixed pulley, while pulleys 62c attached to slider 22a and 62 attached to slider 22d function as a single movable pulley. Because the pulley 62 attached to slider 22 functions as a movable pulley, the weight of the counterweight 60 suspended using the pulley 62 functioning as a fixed pulley acts as a force to lift the slider 22 to which the pulley 62 functioning as a movable pulley is attached. Since the force that lifts the slider 22 acts as a force that lifts the loading platform 3, the burden when lifting the loading platform 3 can be reduced.

[0057] As described above, the assist mechanism 6 in this embodiment utilizes the principle of a movable pulley. Therefore, if the assist mechanism 6 shown in Figure 14 is installed on only one side of the lifter device 1, a force twice the weight of the counterweight 60 will act as the force that lifts the slider 22. If the force that lifts the slider 22 acts on only one side, either the left or the right, the loading platform 3 cannot be lifted smoothly. Therefore, in this embodiment, as shown in Figure 1, the assist mechanism 6 is installed on both the left and right sides of the lifter device 1, and the weight of the counterweight 60 is set to one-quarter of the weight of the heavy object loaded on the loading platform 3, thereby canceling out the weight of the heavy object loaded on the loading platform 3 by the assist mechanism 6.

[0058] The reason why the assist mechanism 6 cancels only the weight of the heavy object loaded onto the cargo bed 3 is to ensure that the cargo bed 3 can be locked even when the lifter device 1 is equipped with the assist mechanism 6. Even if the assist mechanism 6 cancels the weight of the heavy object loaded onto the cargo bed 3, the weight of the cargo bed 3 is not canceled. When the first head section 420 rotates 90 degrees downward and contacts the first body section 421, and the pair of first lever arms 41, the first hinge joint 42, the first connecting rod, and the pair of first push-up arms 44 become one unit, the force F shown in Figure 9 is generated by the weight of the cargo bed 3, and the cargo bed 3 can be locked. The same applies to the second lifter mechanism 5. Note that when the lifter device 1 is equipped with the assist mechanism 6, a force that raises the cargo bed 3 is always acting on the cargo bed 3 even when no heavy object is loaded. For this reason, it is desirable to provide a mechanism in both the first lifter mechanism 4 and the second lifter mechanism 5 to fix the cargo bed 3 at its initial height when no heavy object is loaded.

[0059] The lifter device 1 described above can be used like a hand lifter, but it is best suited for use in combination with other devices. For example, by adjusting the first lift height to match the height of the conveyor and placing the lifter device 1 at the entrance of the conveyor, the workload of loading heavy objects onto the conveyor can be reduced. [Explanation of symbols]

[0060] 1. Lifter device 2. Stand 20 support frame 200 casters 21 Horizontal frame 22 Slider 23 Bracket for the first support point 24. Bracket for the second support point 3. Cargo bed 30 Stopper 300 Rotary Connectors 31. Cargo bed frame 32 Pair of roller conveyors 33. First plate-shaped bracket 330 Stopper Bracket 34. Second plate-shaped bracket 340 Contact Plate 4. First lifter mechanism 40. First support roller 400 Rotary Connectors 41 Pair of first lever arms 42. First hinge joint 420 First Head Section 421 First fuselage 422 First hinge axis 43. First connecting arm 44 Pair of first lifting arms 45 handle 46. ​​First lock release lever 460 First lever section 461 First Stage Section 4610 vertical bar 4611 horizontal bar 47. First connecting frame 5. Second lifter mechanism 50 Second pivot roller 500 Rotary Connectors 51 Pair of second lever arms 52 Second hinge joint 520 Second Head Section 521 Second fuselage section 53 Second connecting arm 54. Second Push-Up Arm 540 Contact roller 5400 Silicone Rubber 55 pedals 56. Second lock release lever 560 Second lever section 561 Second Stage Section 57. Second connecting frame 6. Assist mechanism 60 weight 61 Wire component 62 Pulleys 63 Frame for assist mechanism

Claims

1. A frame comprising at least four support columns and horizontal bars connecting adjacent support columns, A slider slidably attached to the aforementioned support frame, A loading platform connected to the aforementioned slider and equipped with a stopper on its underside, A lifter mechanism for raising a loading platform using the principle of leverage comprises: a pair of first lever arms pivotally supported on a first pivot roller attached to the frame; a first hinge joint having a first body portion connected to the ends of the pair of first lever arms and a first head portion that can rotate 180 degrees vertically relative to the first body portion; a first connecting arm connecting the first head portions of the first hinge joints provided on each of the pair of first lever arms; and a pair of first push-up arms connected at approximately a right angle to the first connecting arms, with their tips attached to the stopper on the loading platform. The lifter mechanism is configured such that when the loading platform is raised to a first lift height, the first head portions of the first hinge joints rotate 90 degrees downward and come into contact with the first body portion, thereby locking the loading platform at the first lift height. A lifter device characterized by being equipped with the following.

2. The lifter device according to claim 1, characterized by comprising a first stay portion attached to the lower side of the first connecting arm and substantially perpendicular to the first connecting arm, and a first lock release lever having a first lever portion attached to the end of the first stay portion facing upward.

3. A lifter device according to claim 1 or 2, characterized in that each of the two sliders is provided with a pulley, one end of a wire member is fixed to one of the support frames, the wire member is passed under each of the pulleys, and a weight is hung from the other end of the wire member that is not fixed to the support frame, so that the weight of the weight acts as a force to raise the platform.

4. The lifter mechanism comprises a pair of second lever arms pivotally supported by a second pivot roller attached to the frame, a second hinge joint having a second body connected to the ends of the pair of second lever arms and a second head that can rotate 180 degrees vertically relative to the second body, a second connecting arm connecting the second heads of the second hinge joints provided on each of the pair of second lever arms, and a pair of second push-up arms provided substantially perpendicular to the second connecting arm and having a contact roller at their tip for contacting the underside of the loading platform, wherein when the loading platform is raised to a second lift height, the second heads of the second hinge joints rotate 90 degrees downward and contact the second body, locking the loading platform at the second lift height. The lifter device according to claim 1 or 2, characterized in that the first lifter mechanism and the second lifter mechanism are arranged opposite each other, and the second lifter mechanism raises the cargo bed to the second lift height, which is then raised by the first lifter mechanism to the first lift height.

5. The lifter device according to claim 4, characterized by comprising a second stay portion attached to the lower side of the second connecting arm and substantially perpendicular to the second connecting arm, and a second lock release lever having a second lever portion attached to the end of the second stay portion facing upward.

6. The lifter device according to claim 4, characterized in that each of the two sliders is provided with a pulley, one end of a wire member is fixed to one of the support frames, the wire member is passed under each pulley, and a weight is hung from the other end of the wire member that is not fixed to the support frame, so that the weight of the weight acts as a force to raise the platform.

7. The lifter device according to claim 5, characterized in that each of the two sliders is provided with a pulley, one end of a wire member is fixed to one of the support frames, the wire member is passed under each of the pulleys, and a weight is hung from the other end of the wire member that is not fixed to the support frame, so that the weight of the weight acts as a force to raise the platform.

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