jack device

Abstract

To provide a jack device used for lifting and moving heavy objects such as a bed or furniture with legs. [Solution] A jack device 1 is provided with a main body 2, forks 3 having flat portions 3a that support heavy objects from below, a handle 4 on which human power is applied, and a connecting rod 6 that connects the main body 2 and the forks 3, the main body 2 having an upper through-hole 2f and a lower through-hole 2g formed therein, the forks 3 being located at the front end of the main body 2, the forks 3 having an upper through-hole 3c and a lower through-hole 3d formed therein, the handle 4 protruding rearward from the main body 2, the handle 4 having a rear through-hole 4d and a front through-hole 4c formed therein, holes 6a formed at both ends of the connecting rod 6, the handle 4 being journalled to the main body 2, the forks 3 being journalled to the handle 4, the forks 3 being journalled to the connecting rod 6, and the connecting rod 6 being journalled to the main body 2, thereby enabling heavy objects to be lifted.

Description

[Technical Field]

[0001] The present invention relates to a jack device used to safely and quickly secure a gap between the bottom or soles of the legs of a heavy object and the floor surface to easily insert a cart or slide, in order to move the heavy object, such as a bed or furniture with legs, used indoors in homes, offices, stores, etc. [Background technology]

[0002] Figure 18 shows a conventional heavy-duty lifting device. This conventional example is similar to the one described in Patent Document 1, for example. The device has a fork 100a at the front end of a main body 100 for inserting it into the bottom of a heavy object to hold the heavy object, a handle 100b at the rear, and a plurality of rollers 100d journaled by shafts 100c at the bottom. When height adjustment is required, as disclosed in Patent Document 2, a base 101 and a connecting platform 102 are installed below the rollers 100d to adjust the height, and the device is designed to be used in combination with four transport carts to be placed under the heavy object. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Registered Utility Model No. 3109851 [Patent Document 2] Patent No. 6089276 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned heavy-duty lifting device, as shown in Figure 19, when an attempt is made to lift furniture without a bottom, such as a bed 50, the flat surface 100e of the fork 100a rotates significantly around the axis 100c of the roller 100d as a fulcrum, causing the bottom surface 50b of the side panel of the bed 50 to slide down toward the axis 100c, which means that a sufficient gap cannot be secured between the bed 50 and the floor surface F, making it impossible to insert a cart and making it unusable.

[0005] Furthermore, with the recent spread of cleaning robots, many furniture pieces with a long distance from the floor F to the bottom surface 50b of the furniture 50 are being sold and used, and when multiple connecting stands 102 are connected to adjust the height, as shown in Figure 20, after the tip 100f of the flat portion 100e of the fork 100a comes into contact with the bottom surface 50b of the heavy object 50, the axis 100c of the roller 100d begins to rotate around the tip 100f of the flat portion 100e, the roller 100d moves toward the heavy object 50, and the fulcrum axis 100c moves away from the center C of the base stand 101 to C', causing the multiple connecting stands 102 connected in succession to wobble or fall over, which is very dangerous.

[0006] Furthermore, since the height could only be adjusted in stages by combining the base stand 101 and the connecting stand 102, it was not possible to adjust the intermediate range of the height of each of the base stand 101 and the connecting stand 102. [Means for solving the problem]

[0007] The jack device of the present invention, which has been made to solve the above problems, comprises a main body, forks having flat portions for supporting a heavy object from below, a handle for applying human power, and a connecting rod for connecting the main body and the forks, the main body having an upper through hole and a lower through hole located below the upper through hole, the forks being located at the front end of the main body and having an upper through hole and a lower through hole located below the upper through hole, the handle having a rear end protruding rearward from the main body and having a rear through hole for connecting to the main body and a front through hole for connecting to the forks, The connecting rod has holes formed at both ends, the handle is journaled to the body with its shaft inserted through the upper through-hole of the body and the rear through-hole of the handle, the fork is journaled to the handle with its shaft inserted through the upper through-hole of the fork and the front through-hole of the handle, the fork is journaled to the connecting rod with its shaft inserted through the lower through-hole of the fork and a hole on the front end of the connecting rod, and the connecting rod is journaled to the body with its shaft inserted through the lower through-hole of the body and a hole on the rear end of the connecting rod.

[0008] The distance between the two holes in the connecting rod is longer than the distance between the front through-hole and the rear through-hole in the handle.

[0009] Furthermore, the upper through-hole of the main body is characterized by being located in the center in the front-rear direction.

[0010] The device is characterized in that a screw cylinder consisting of an inner screw cylinder and an outer screw cylinder is detachably positioned at the bottom center of the main body. [Effects of the Invention]

[0011] In the above-mentioned means, the fork doubles as one link of the four-link mechanism, so that the holding surface of the furniture does not tilt significantly from the horizontal even when the fork moves up and down, and even in the case of furniture without a base, such as a bed, the bottom of the side panel does not slide down, preventing insufficient lifting height.

[0012] The handle doubles as one link of a four-link mechanism, and because the handle is connected to the fork by an axis, there is little mechanical loss in the transmission of force when the fork moves up and down, and the fork movement does not become an intermittent movement of slipping and sticking due to friction.In addition, by using the principle of leverage, with the rear through-hole of the handle as the fulcrum, the rear end of the handle as the force point, and the front through-hole of the handle as the action point, heavy furniture can be lifted with little force.

[0013] The main body and the screw cylinder are fitted and hooked together, so they can be attached and detached without tools, and when there is a gap large enough that the bottom of the furniture touches the floor, it can be easily lifted by using only the main body.

[0014] Furthermore, the tool-free detachability allows for quick and compact storage and transportation.

[0015] Furthermore, the screw cylinder is not constructed of stacked blocks, but can be rotated to freely expand and contract and adjust the height steplessly, so it can accommodate the height of the bottom of any piece of furniture, and there is no stress such as having to consider the combination of parts specific to stacked structures or being unable to use it due to missing parts. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a perspective view of a jack device according to the present invention; [Figure 2] 1 is a front view of a jack device according to the present invention; [Figure 3] 1 is a side view of a jack device according to the present invention; [Figure 4] AA cross-sectional view of the jack device according to the present invention. [Figure 5] 1 is a perspective view of a main body of a jack device according to the present invention; [Figure 6] 1 is a perspective view of a screw bore of a jack device according to the present invention; [Figure 7] 1 is a perspective view of a screw outer cylinder of a jack device according to the present invention; [Figure 8] AA section of the handle of the jack device according to the present invention. [Figure 9] AA cross-sectional view of the fork of the jack device according to the present invention. [Figure 10] 1 is a side view of a connecting rod of a jack device according to the present invention; [Figure 11] 1 is a cross-sectional view illustrating an example of use of the jack device according to the present invention; [Figure 12] FIG. 1 is a side view of a partially cutaway view illustrating an example of installation and use of a jack device according to the present invention. [Figure 13] 1 is a perspective view illustrating an example of use of a jack device according to the present invention; [Figure 14] Side view of partial cross section of example of use when removing the screw barrel [Figure 15] Side view of a partial cross section of the screw barrel for starting use of the shortest length [Figure 16] Side view of a partial cross section of an example of how to start using the intermediate length screw barrel [Figure 17] Side view of the longest length of the screw barrel [Figure 18] A perspective view of a conventional heavy-duty lifting device. [Figure 19] A side view of a part in section illustrating an example of operation of a conventional heavy-duty lifting device. [Figure 20] Side view of a conventional heavy lifting device for explaining operation example 2 DETAILED DESCRIPTION OF THE INVENTION [Example]

[0017] FIG. 1 is a perspective view of a jack device according to an embodiment of the present invention.

[0018] Figures 2, 3, and 4 show a front view, a side view, and a cross-sectional view, respectively. This jack device is equipped with a main body, a fork with a flat surface that supports a heavy object from below, a handle for applying human power, and a connecting rod that connects the main body and the fork.

[0019] The main body 2 supports the handlebars and connecting rod, and the front end 2a of the main body 2 is open to support the handlebars 4 and fork 3, and the connecting rod 6 and fork 3. The main body 2 is open in approximately the upper half of the rear end 2d and a rear portion of the top surface 2c, allowing the operating portion 4a of the handlebars 4 to protrude. The bottom surface 2e of the main body 2 is open and shaped to fit with the threaded inner tube 10. As shown in FIG. 5, the main body 2 has notches 2b formed in the lower portions of both sides to allow the claws 10a of the threaded inner tube 10 to penetrate and engage, so that the main body 2 can be attached and detached from the threaded inner tube 10 without tools. The main body 2 also has a pair of upper through-holes 2f, one on each side, located in the center of the front-rear direction, and a lower through-hole 2g located below the upper through-holes 2f, to support the handlebars 4 and connecting rod 6. As shown in FIG. 4, the upper through-holes 2f of the main body 2 are aligned with the center 15a of the threaded tube 15, and the lower through-hole 2g of the main body 2 is located toward the lower rear end of the upper through-holes 2f.

[0020] As shown in Figure 8, the handle 4 has front through-holes 4c on both sides at its front end 4b for pivotal support with the upper through-holes 3c of the forks 3, and a rear through-hole 4d at a distance L1 of approximately one-sixth of the handle 4's total length toward the rear end from the front through-hole 4c for connection to the main body 2. The rear end 4e of the handle 4 is positioned above a line 4f connecting the centers of the front through-hole 4c and the rear through-hole 4d, and the grip 5 is provided with a shape and material that is soft and non-slip for easy gripping, allowing for safe and secure manual operation. This is because, when using a bed 50 with short legs 50b without the screw cylinder 15, as shown in Figures 11 and 14, the grip 5 does not come into contact with the floor surface F, preventing a reduction in the operating opening angle θ1 of the handle 4.

[0021] 10 and 11, holes 6a are formed at the front and rear ends of the connecting rod 6 so that it can be pivotally supported in the lower through-hole 3d of the fork 3 and the lower through-hole 2g of the main body 2. The hole 6a at the front end is positioned at an appropriate distance directly below the front through-hole 4c of the handle 4, and the distance L2 between the holes 6a is set to about 1.5 times the distance L1 between the front through-hole 4c and the rear through-hole 4d of the handle 4, so that the dependent opening angle θ2 of the connecting rod 6 is smaller than the operating opening angle θ1 of the handle 4.

[0022] The fork 3 is located at the front end 2a of the main body 2. As shown in FIG. 9 , a vertical surface 3e is provided above the rear end 3f of the flat portion 3a for holding the furniture 50. An upper through-hole 3c and a lower through-hole 3d located below the upper through-hole 3c are formed on the main body 2 side of the vertical surface 3e, and are pivotally supported by the front through-hole 4c of the handle 4 and the hole 6a of the connecting rod 6. The distance L3 between the upper through-hole 3c and the lower through-hole 3d is set so that the position of the line 4f connecting the centers of the front through-hole 4c and the rear through-hole 4d of the handle 4 and the position of the line 6b connecting the centers of the two holes 6a of the connecting rod 6 are parallel to the flat portion 3a. The furniture 50 is held at the upper end 3b of the vertical surface 3e, and the pusher unit 14 is provided with a shape and material that is moderately soft so as not to scratch the furniture 50 or cause it to slip and fall. The upper end 3b of the vertical surface 3e of the fork 3 functions as a second point for holding the furniture 50, so that it is possible to lift furniture 50 whose bottom is too high for the flat surface 3a of the fork 3, as shown in Figure 17, and tables with even higher bottoms can also be used. The distance h between the flat surface 3a for holding the furniture 50 and the upper surface 14a of the pusher part of the upper end 3b of the vertical surface 3e is set to the same as the maximum extension distance H of the screw cylinder 15, so that it can be continuously and seamlessly adapted to the various lengths of the legs 50b of the furniture 50.

[0023] The handle 4 is journaled to the main body 2 through a shaft 7 inserted through the upper through-hole 2f of the main body 2 and the rear through-hole 4d of the handle 4. The fork 3 is journaled to the handle 4 through a shaft 8 inserted through the upper through-hole 3c of the fork 3 and the front through-hole 4c of the handle 4, and is journaled to the handle 4. The fork 3 is journaled to the connecting rod 6 through a shaft 8 inserted through the lower through-hole 3d of the fork 3 and the hole 6a at the front end of the connecting rod 6. The connecting rod 6 is journaled to the main body 2 through a shaft 7 inserted through the lower through-hole 2g of the main body 2 and the hole 6a at the rear end of the connecting rod 6. This four-bar link mechanism configuration positions the shaft 7 inside the main body 2 and is always inside even within the operating range θ1 of the handle 4 when viewed from the left and right sides, preventing the shaft 8 from coming loose and improving the design. The shaft 7, which is used by passing through the main body 2, has a retaining flange on one side and a groove on the other side, with an E-ring attached to prevent it from coming loose.

[0024] The elastic body 9 uses a torsion coil spring, and is positioned on the shaft 7 that supports the upper through-hole 3c of the fork 3 and the front through-hole 4c of the handle 4, and always acts in the direction of opening the fork 3 and the handle 4. As shown in Figure 12, when installing the jack device 1, the flat surface 3a of the fork 3 is always located at its lowest point, so there is no need to operate the handle 4 to keep the flat surface 3a at its lowest point and rotate the screw cylinder 15 to position it. The user can simply concentrate on extending and retracting the screw cylinder 15 so that the flat surface 3a of the fork 3 abuts against the bottom surface of the furniture 50, making installation extremely easy and quick.

[0025] According to the four-bar link mechanism consisting of the main body 2, handle 4, connecting rod 6, and fork 3 of the jack device 1 of the present invention, the dependent opening angle θ2 of the connecting rod 6 becomes small within the range of the operating opening angle θ1 of the handle 4, so the flat surface 3a of the fork 3 is used in a range where it is slightly inclined from horizontal toward the main body 2, and there is no need to worry about the bottom surface 50a of the side panel of the bed 50 slipping off the flat surface 3a of the fork 3.

[0026] The screw tube 15 is composed of an inner screw tube 10 and an outer screw tube 11, and as shown in Figure 6, the upper and lower bottom surfaces of the inner screw tube 10 are open, and a spiral convex shape 10b is provided on the outer periphery of the side surface.When the lower bottom surface of the inner screw tube 10 and the lower bottom surface of the outer screw tube 11 are placed on the same plane, the shape of the side surface 10d from the height portion above the upper bottom surface of the outer screw tube 11 to the upper bottom surface of the inner screw tube 10 is set to be a plane-symmetrical shape with respect to a vertical plane passing through the center line when viewed from the top bottom surface, so that it can be fitted and engaged with the main body 2 in either the forward or backward direction.

[0027] The side surface 10d near the upper bottom surface of the screw inner tube 10 engages with the main body 2 by providing elastically deformable claws 10a at two opposing locations, allowing it to be attached and detached without tools.This means that it will not come off from the main body 2 unless multiple claws 10a are pressed at the same time, making it safe and preventing it from coming off accidentally.Furthermore, a stopper 10c is provided on the outer periphery that contacts the lower bottom surface to prevent it from coming off the screw outer tube 11, limiting it to not exceeding the maximum height H, providing safety measures to prevent accidental removal by the user or buckling damage due to insufficient engagement with the spiral convex shape 11c of the screw outer tube 11.

[0028] As shown in Figure 7, the screw outer tube 11 has open upper and lower bottom surfaces, with the lower bottom surface having a larger diameter than the upper bottom surface. The side surfaces are cylindrical for about two-thirds of the way from the upper to the lower bottom surface, and the inner circumference prevents the screw inner tube 10 from tilting. The inner circumference gradually widens as it approaches the lower bottom surface, allowing it to stand on its own and be stable using only a jacking device. A spiral convex shape 11c is formed only on the inner circumference near the upper bottom surface on the inside of the side surface. To prevent buckling failure even when used at maximum extension, the number of threads on the spiral convex shape 11 is set to about 2.5, and part or all of the outer circumference that contacts the lower bottom surface on the outside of the side surface is made uneven 13a.

[0029] The screw outer cylinder 11 of the embodiment of the present invention is made of four parts using a thermoplastic resin molded product for cost advantages. The screw outer cylinder 11 is divided into left and right halves, which are the right screw outer cylinder 11a and the left screw outer cylinder 11b. An upper annular retaining ring 12 and a lower retaining ring 13 are fitted and hooked onto each other near the top and bottom surfaces to prevent the right screw outer cylinder 11a and the left screw outer cylinder 11b from opening. The side of the lower retaining ring 13 has an uneven shape 13a, which does not injure the fingers or palms when operated with bare hands, does not cause pain, and is a non-slip shape. Therefore, even people with weak grip strength can easily operate it manually without their fingers slipping.

[0030] The helical convex shape 10b of the inner screw tube 10 and the helical convex shape 11c of the outer screw tube 11 are rotatably fitted to each other, and the forward and reverse rotational motion causes the entire length of the screw tube 15 to expand and contract and is converted into a linear reciprocating motion, so that it can accommodate the height of the legs 50b of all furniture 50 as shown in Figures 15, 16, and 17.

[0031] As described above, in the jack device 1 according to the embodiment of the present invention, as shown in Figure 13, both the operation of the handle 4 and the extension and retraction of the screw tube 15 are performed manually, making it possible to easily and safely abut the slide 30 against the back of the leg 50b of the bed 50. [Explanation of symbols]

[0032] 1. Jacking device 2 Main unit 2a Front end of the main body 2f Upper through hole of the main body 2g Bottom through hole of the main body 3 forks 3a Flat part of fork 3c Upper fork through-hole 3D fork bottom through-hole 4 Handle 4a Rear end of handle 4c Front through-hole of handle 4d Rear through hole of handle L1 Distance between the front and rear holes of the handle 5 Grip 6 Connecting rod 6a Connecting rod hole L2: The distance between the two holes in the connecting rod 7 axes 8 axes 10 Threaded inner cylinder 11 Screw outer cylinder 12 Retaining ring top 13 Under the retaining ring 14 Pusher section 15 Screw barrel 15a Center of the screw barrel 30 Sliding Objects 50 Heavy objects, furniture, and bedding

Claims

1. In a jack device that lifts heavy objects from below, The device comprises a main body, a fork having a flat surface for supporting a heavy object from below, a handle for applying human power, and a connecting rod for connecting the main body and the fork, The main body is formed with an upper through hole and a lower through hole located below the upper through hole, The fork is located at the front end of the main body, and has an upper through hole and a lower through hole located below the upper through hole. The handle has a rear end that protrudes rearward from the main body, and has a rear through-hole for connection to the main body and a front through-hole for connection to the fork. The connecting rod has holes at both ends, The handle is supported by the main body with a shaft inserted through the upper through-hole of the main body and the rear through-hole of the handle. The fork is supported on the handle by a shaft inserted through the upper through-hole of the fork and the front through-hole of the handle, Furthermore, the fork is supported by the connecting rod with a shaft inserted through the lower through-hole of the fork and the hole at the front end of the connecting rod, The connecting rod is supported by the main body with a shaft inserted through the lower through-hole of the main body and the hole at the rear end of the connecting rod. A jack device characterized in that the distance between the two holes in the connecting rod is longer than the distance between the front through hole and the rear through hole in the handle.

2. A jack device as described in claim 1, in which a screw tube consisting of an inner screw tube and an outer screw tube is detachably positioned at the bottom center of the main body.

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