Slope device and tilt angle adjustment mechanism for variable slope plate in the slope device

Abstract

To provide a slope device capable of easily adjusting the inclination angle of a slope plate in a short time.SOLUTION: A slope device 1 includes: a base frame 2 arranged on a lower level surface G2 of a passage; a variable slope plate 3 having a rear end rotatably connected to the base frame; and a support unit 4 provided between the base frame and the variable slope plate and supporting the variable slope plate so as to freely adjust an inclination angle. The support unit includes: a screw shaft 41 extending in the front-rear direction and rotatably attached to a base frame around an axis; a feed nut 42 screwed to the screw shaft and moved in the front-rear direction with the rotation of the screw shaft; support arms 43A, 43B having one end rotatably connected to a feed nut and the other end rotatably connected to a variable slope plate; and a rotation operation part 44 for rotating a screw shaft.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a slope device that is installed at a step portion of a passage surface where a transport cart such as a handcart or a loading and unloading vehicle such as a forklift moves, for example, at various work sites, factory facilities, logistics facilities, etc., and is used to eliminate the step.

Background Art

[0002] On a passage surface having a step, for example, it may be difficult for a handcart or a forklift to move over the step. Therefore, a slope device has been conventionally used to eliminate this step and enable the movement of a handcart or the like without hindrance.

[0003] As a slope device, for example, the one described in Patent Document 1 below is known. This slope device includes a frame-shaped main body portion disposed on the lower surface, a slope plate portion provided so as to be tilt angle adjustable with respect to the main body portion, two left and right slope plate support mechanisms that respectively support the left and right sides of the slope plate portion, and two left and right slope plate tilt holding mechanisms that suppress the movement of each slope plate support mechanism and hold the slope plate portion at a required tilt angle. Each slope plate support mechanism includes a scottruss link mechanism, that is, a first link member whose one end is rotatably connected to the slope plate portion and the other end horizontally moves in the front-rear direction along the main body portion, and a second link member whose one end is rotatably connected to the main body portion and the other end is rotatably connected to the middle of the longitudinal direction of the first link member. In addition, each slope plate tilt holding mechanism includes a stopper portion provided on the main body portion having a box shape with a through hole extending in the front-rear direction, a position adjustment guide portion composed of a bolt whose head side is rotatably connected to the moving end portion of the first link member and the tip side is inserted into the through hole of the stopper portion, and a stopper locking portion composed of a nut screwed onto the bolt and locked to the stopper portion. In the above-described ramp device, the range of movement of the movable end of the first link member of each ramp support mechanism can be changed by rotating the nuts (stopper locking parts) of the left and right ramp plate inclination holding mechanisms by the required amount in the required rotational direction, thereby allowing the inclination angle of the ramp plate to be changed and adjusted to match the height of the step at the installation site. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2005-207145 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] However, in the case of the above-mentioned ramp device, the inclination angle of the ramp plate is adjusted by rotating the nuts (stopper locking parts) of the two ramp plate inclination holding mechanisms on the left and right sides. This requires time and effort to perform these rotational operations and adjust the positions of the nuts on the left and right sides, resulting in problems with usability.

[0006] This invention has been made in view of the above-mentioned problems, and aims to provide a ramp device that allows for quick and easy adjustment of the inclination angle of the ramp plate. [Means for solving the problem]

[0007] To achieve the above objective, this invention comprises the following embodiments.

[0008] 1) A ramp device for eliminating the difference in level between the upper surface of a passageway and the lower surface located behind it, The base frame is positioned on the lower surface, A variable slope plate whose rear end is rotatably connected to the base frame and whose upper surface forms a slope surface, It includes a support unit provided between the base frame and the variable slope plate, which supports the variable slope plate so that its inclination angle can be freely adjusted. The support unit is a ramp device comprising: a screw shaft extending in the front-rear direction and rotatably mounted on a base frame about its axis; a feed nut screwed onto the screw shaft and moving in the front-rear direction as the screw shaft rotates; a support arm with one end rotatably connected to the feed nut and the other end rotatably connected to a variable ramp plate; and a rotation operating unit for rotating the screw shaft.

[0009] 2) The screw shaft is attached to the base frame so as to be located below the center of the left-right width of the adjustable ramp plate. The ramp device according to 1) above, wherein the support arm comprises a left support arm whose one end is rotatably connected to the left half of the feed nut and whose other end is rotatably connected to the left half of the variable ramp plate, and a right support arm whose one end is rotatably connected to the right half of the feed nut and whose other end is rotatably connected to the right half of the variable ramp plate.

[0010] 3) The screw shaft is attached to the base frame such that its front end protrudes near the lower part of the front end of the adjustable slope plate. A ramp device according to 1) or 2) above, wherein the rotating operating part is provided at the front end of the screw shaft.

[0011] 4) The support unit further includes a left-hand drive rotating shaft that extends in the left-right direction, with its right end connected to either the front or rear end of the screw shaft via a gear mechanism for interlocking, and its left end protruding near the lower part of the left edge of the variable slope plate, and / or a right-hand drive rotating shaft that extends in the left-right direction, with its left end connected to either the front or rear end of the screw shaft via a gear mechanism for interlocking, and its right end protruding near the lower part of the right edge of the variable slope plate, and is rotatably mounted on the base frame about its axis. The ramp device according to 1) or 2) above, wherein the rotating operating part is provided at the left end of the left rotation shaft for power transmission and / or at the right end of the right rotation shaft for power transmission.

[0012] 5) A ramp device according to any one of 1) to 4) above, wherein the rotating operation section consists of a rotating operation head that can be connected to an electric rotary tool.

[0013] 6) A ramp device according to any one of 1) to 5) above, wherein the variable ramp plate has a pair of left and right vertical frame members and a plurality of top plate members that are arranged in the front-to-back direction between the left and right vertical frame members and fastened with bolts. [Effects of the Invention]

[0014] According to the ramp device described in 1) above, the inclination angle of the variable ramp plate can be arbitrarily changed and adjusted to match the height of the step by rotating one screw shaft of the support unit in the required direction by the required angle via the rotation operation part. This adjustment work can be performed quickly and easily, resulting in excellent operability.

[0015] According to the ramp device described in 2) above, the variable ramp plate can be stably supported by the two support arms on the left and right of the support unit, so there is no risk of rattling or shaking of the variable ramp plate during use. Furthermore, this ramp device maintains the operability when adjusting the inclination angle of the variable ramp plate mentioned above, while also increasing the durability of the ramp device. Furthermore, this ramp device simplifies the structure of each support arm, making manufacturing easier, reducing costs, and making it easier to obtain the required load-bearing strength.

[0016] According to the ramp device described in 3) above, the rotation operation part of the support unit is located at the front end of a screw shaft that protrudes near the lower part of the front end of the variable ramp plate. Therefore, the operation to rotate the screw shaft can be easily performed from the front of the ramp device without having to reach deeply under the variable ramp plate, resulting in excellent operability.

[0017] According to the slope device of 4) above, since the rotation operation part of the support unit is provided at the end of the transmission rotation shaft protruding near the lower part of one of the left and right side edges of the variable slope plate, the operation for rotating the screw shaft can be easily performed from the side of the slope device without deeply inserting a hand below the variable slope plate, and it has excellent operability. In particular, since the operation can be performed in a state where the slope device is arranged such that the front end portion of the variable slope plate is close to the step, the adjustment of the inclination angle of the variable slope plate becomes even easier.

[0018] According to the slope device of 5) above, an electric rotary tool such as an impact driver can be connected to the rotation operation part composed of the rotation operation head, and the screw shaft can be rotated by the electric rotary tool to adjust the inclination angle of the variable slope plate. Therefore, the adjustment work can be performed very easily in a short time.

[0019] According to the slope device of 6) above, since the variable slope plate is formed by bolting the left and right vertical frame members and a plurality of upper surface plates, even if some upper surface plates are damaged during use, only the damaged upper surface plates can be easily replaced, which is economical.

Brief Description of the Drawings

[0020] [Figure 1] It is a perspective view showing the overall configuration of the slope device according to the first embodiment of this invention. [Figure 2] It is a left side view of the slope device. [Figure 3] It is a plan view of the slope device. [Figure 4] It is a front view of the slope device. [Figure 5] It is a plan view showing the base frame and the support unit (excluding the left and right support arms) of the slope device. [Figure 6] It is a left side view showing the support unit disassembled. [Figure 7]This is a left side view showing the ramp device in its folded state. [Figure 8] This is a left side view of a ramp device according to a second embodiment of the present invention. [Figure 9] This is a front view of the ramp device. [Figure 10] This is a plan view showing the base frame and support unit (excluding the left and right support arms) of the ramp device. [Modes for carrying out the invention]

[0021] Next, embodiments of this invention will be described with reference to Figures 1 to 10. In the following explanation, the right side of Figures 2 and 8 will be referred to as the "front," the left side as the "rear," and "left and right" will refer to the left and right sides when viewed from the front (the left and right sides of Figures 4 and 9).

[0022] [First Embodiment] Figures 1 to 7 show a ramp device according to the first embodiment of this invention. As shown in Figures 1-4, the overall configuration of the ramp device (1) according to this embodiment is for eliminating the step (G3) that occurs between the upper surface (G1) of a passageway and the lower surface (G2) located behind it, and comprises a base frame (2) positioned on the lower surface (G2), a variable ramp plate (3) whose rear end is rotatably connected to the base frame (2) and whose upper surface constitutes a ramp surface (30), and a support unit (4) provided between the base frame (2) and the variable ramp plate (3) and supporting the variable ramp plate (3) so as to be able to adjust its inclination angle. Furthermore, the ramp device (1) includes a fixed ramp plate (5) whose front end is rotatably connected to the base frame (2) and which is positioned on the lower surface (G2). The upper surface of the fixed ramp plate (5) forms a ramp surface (50) that is connected to the rear end of the ramp surface (30) of the variable ramp plate (3).

[0023] As shown in Figure 5, the base frame (2) is roughly rectangular in shape when viewed from above. More specifically, the base frame (2) has two vertical frame members (21) on the left and right, and three horizontal frame members (22A), (22B), and (22C) that are attached to the front ends, rear ends, and mid-length sections of the two vertical frame members (21), respectively. Each left and right vertical frame member (21) has an L-shaped cross-section, having a horizontal wall section (211) and a vertical wall section (212) extending upward from the left and right outer edges of the horizontal wall section (211). Drainage holes (211a) are formed in the horizontal wall section (211) as needed. The rear horizontal frame member (22C) also has an L-shaped cross-section, having a horizontal wall section (221) and a vertical wall section (222) extending upward from the rear side edge of the horizontal wall section (221). The front horizontal frame member (22A) and the intermediate horizontal frame member (22B) function as mounting parts for attaching the screw shaft (41) of the support unit (4) described later, and each is hollow with a roughly rectangular cross-section (see also Figures 2, 6, etc.). As shown in Figures 5, 6, a reinforcing core member (23) with a roughly rectangular cross-section may be fitted inside the intermediate horizontal frame member (22B). A roughly rectangular bottom plate (25), as viewed from above, is attached between the lower surfaces of the front horizontal frame member (22A) and the intermediate horizontal frame member (22B). Short, upwardly extending raised edges (251) are formed on the left and right side edges of the bottom plate (25), except for the front and rear ends that are joined to the lower surfaces of the front horizontal frame member (22A) and the intermediate horizontal frame member (22B). In addition, one or more parallel protrusions (252) extending in the front-to-back direction are formed in the middle of the left-to-right width of the upper surface of the bottom plate (25), except for the front and rear ends. This bottom plate (25) functions as a slide base for sliding the feed nut (42) of the support unit (4), which will be described later. Drainage holes (253) are formed in the bottom plate (25) as needed. Furthermore, as shown in Figure 5, the base frame (2) may also be equipped with multiple diagonal frame members (24) (in this case, two each at the front and back, for a total of four) that are anchored between the intermediate horizontal frame member (22B) and the left and right vertical frame members (21), and these diagonal frame members (24) further enhance the strength of the base frame (2). The vertical frame members (21), horizontal frame members (22A)(22B)(22C), reinforcing core members (23), and diagonal frame members (24) that constitute the base frame (2) are preferably made of light metal materials, and more preferably made of aluminum alloy materials (especially aluminum alloy extruded profiles) which are lightweight, strong, and have excellent workability and corrosion resistance. The joining of two vertical frame members (21) and three horizontal frame members (22A), (22B), and (22C), and the joining of an intermediate horizontal frame member (22B) and multiple diagonal frame members (24) are usually done by welding, but other joining means (e.g., bolt fastening, riveting, etc.) may also be used.

[0024] As shown in Figure 3, the variable slope plate (3) is roughly rectangular when viewed from above. More specifically, the variable slope plate (3) has a pair of left and right vertical frame members (31) and a plurality (five in this case) of top plate members (32A)(32B)(32C) that are stretched and joined across the left and right vertical frame members (31) in the front-to-back direction. The vertical frame material (31) and top plate material (32A), (32B), and (32C) that constitute the variable slope plate (3) are preferably made of a light metal material, and more preferably made of an aluminum alloy material (particularly an aluminum alloy extruded profile) which is lightweight, strong, and has excellent workability and corrosion resistance. It is preferable that each top panel (32A), (32B), and (32C) is fastened and fixed to the left and right vertical frame members (31) by bolts (33). The top surfaces of the top panels (32A), (32B), and (32C) constitute a ramp surface (30) for transport carts and the like to run on, and it is conceivable that some of the top panels (32A), (32B), and (32C) may be damaged by impact during use of the ramp device (1). Therefore, by configuring the top panels (32A), (32B), and (32C) to be joined to the left and right vertical frame members (31) by fastening with bolts (33) as described above, the ramp device (1) can be used continuously by simply replacing the damaged top panels (32A), (32B), and (32C), which is economical. However, the configuration of the variable slope plate is not limited to the above-described embodiment. Specifically, for example, the variable slope plate may comprise a pair of left and right vertical frame members and a single top plate member whose left and right side edges are welded to the left and right vertical frame members, and this configuration is advantageous in terms of productivity.

[0025] Each vertical frame member (31) has a roughly inverted U-shaped cross-section, for example, as shown in Figure 4, and includes an outer vertical wall section (311), an inner vertical wall section (312), and an upper wall section (313) connecting the upper edges of the outer vertical wall section (311) and the inner vertical wall section (312). The vertical frame member (31) may further include an outer overhanging wall section (314) extending outward in the left-right direction from the lower edge of the outer vertical wall section (311), an inner overhanging wall section (315) extending inward in the left-right direction from the lower edge of the inner vertical wall section (312), and an intermediate partition wall section (316) extending parallel to the upper wall section (313) to divide the interior of the vertical frame member (31) vertically. The vertical width of the outer vertical wall section (311) is greater than the vertical width of the inner vertical wall section (312). The front edges of the outer vertical wall section (311) and the inner vertical wall section (312) are inclined to extend diagonally backward toward the downward direction. The rear of the lower edge of the outer vertical wall section (311) is inclined diagonally upward toward the rear such that the vertical width of the outer vertical wall section (311) gradually narrows toward the rear. Bolt insertion holes (not shown) are provided in the outer vertical wall section (311) and the inner vertical wall section (312) at required locations spaced apart in the front-rear direction.

[0026] Furthermore, in order to increase the load-bearing strength of the variable slope plate (3), as shown in Figure 2, multiple horizontal frame members (34A) (34B) (in this case, a total of four) may be attached between the left and right vertical frame members (31) at intervals in the front-to-back direction. The cross-sectional shape of the horizontal frame members can be set appropriately according to the configuration of the placement location, etc. In this embodiment, the horizontal frame member (34A) located at the front end has a roughly U-shaped cross-section, and inverted U-shaped arm connecting brackets (341) for rotatably attaching the upper ends of the left and right support arms (43A) (43B) of the support unit (4) described later are joined and fixed to both the left and right ends of the lower surface of the horizontal frame member (34A) (see Figures 2 and 4). The remaining horizontal frame members (34B) are, for example, hollow with a roughly rectangular cross-section.

[0027] In this embodiment, the top panel is composed of three types of top panel materials (32A), (32B), and (32C): a first top panel material (32A) positioned at the front end of the variable slope plate (3), three second top panel materials (32B) positioned in the middle of the length of the variable slope plate (3), and a third top panel material (32C) positioned at the rear end of the variable slope plate (3). However, the configuration of the top panel is not limited to this. The first top panel (32A) is hollow with a roughly rectangular cross-section and is the narrowest of the three types. A flange (321) is formed at the front edge of the first top panel (32A) to be attached to the rear edge of the upper surface (G1) of the passageway. The flange (321) is bent diagonally downward at a predetermined angle (for example, about 15°) with respect to the top surface of the first top panel (32A) so that it becomes almost horizontal when the inclination angle of the variable slope plate (3) is set to its maximum (for example, about 15°) (see Figure 2). The second top panel (32B) has a roughly horizontal E-shaped cross-section, comprising an upper wall section and three hanging wall sections extending downward from the front and rear edges of the upper wall section and from the center of the front-to-back width. Short, protruding legs are formed at the lower edge of each hanging wall section. The third upper panel material (32C) is a flattened, hollow shape with a roughly rectangular cross-section, and its rear side is tapered by the lower wall being inclined diagonally upward toward the rear. As shown in Figure 2, female threaded members (35) into which bolts (33) are screwed are placed inside both the left and right ends of each top plate material (32A), (32B), and (32C), and the two are joined and fixed together by rivets (not shown). The upper surface of each top panel material (32A), (32B), and (32C) has multiple anti-slip protrusions and / or grooves extending in the left-right direction, arranged in the front-to-back direction.

[0028] The rear end of the variable ramp plate (3) is rotatably connected to the rear end of the base frame (2) around a pivot axis that extends in the left-right direction. More specifically, the rear end portions of the outer vertical wall section (311) and the inner vertical wall section (312) of each left and right vertical frame (31) of the variable ramp plate (3) are rotatably connected to the upper rear end of the vertical wall section (212) of each left and right vertical frame (21) of the base frame (2) by bolts (36) and nuts (37).

[0029] A handle (6), which is roughly U-shaped when viewed from above, is attached by screws or the like to the outer surface of the midpoint of the vertical wall portion (212) of either the left or right vertical frame (21) (in this case, the left vertical frame (21)) of the variable ramp plate (3). The handle (6) may be attached to both the left and right vertical frames (21), or it may be attached to the outer surface of the vertical wall portion (212) of either one or both of the left and right vertical frames (21) of the base frame (2).

[0030] As shown in Figure 3, the fixed ramp plate (5) is roughly rectangular when viewed from above. The upper surface of the fixed ramp plate (5) forms a ramp surface (50) that is inclined at a predetermined angle (approximately 15° in the figure) to connect the lower surface (G2) and the ramp surface (30) of the variable ramp plate (3). Note that the fixed ramp plate (5) can be omitted, for example, when the size of the ramp device is small. More specifically, the fixed ramp plate (5) has a pair of left and right vertical frame members (51) and a plurality (in this case, three) of top plate members (52A)(52B)(52C) ​​that are stretched across and joined to the left and right vertical frame members (51) in the front-to-back direction. The vertical frame material (51) and top plate material (52A)(52B)(52C) ​​that constitute the fixed ramp plate (5) are preferably made of a light metal material, and more preferably made of an aluminum alloy material (particularly an aluminum alloy extruded profile) which is lightweight, strong, and has excellent workability and corrosion resistance. Each top panel (52A), (52B), and (52C) ​​is preferably fastened and fixed to the left and right vertical frame members (51) by bolts (53), similar to the variable slope plate (3). However, as with the variable slope plate, the fixed slope plate may also be made up of, for example, a pair of left and right vertical frame members and a single top panel member whose left and right side edges are welded to the left and right vertical frame members. Each vertical frame (51), as shown in Figure 2, is a roughly triangular vertical plate that is elongated in the front-to-back direction when viewed from the side. A connecting projection (511) is formed at the lower front end of each vertical frame (51) and protrudes forward. An inner overhanging wall (512) is formed in the middle of the length of each vertical frame (51), extending inward in the left-right direction parallel to the upper edge of each vertical frame (51). Bolt insertion holes (not shown) are made at required locations spaced apart in the front-to-back direction in each vertical frame (51). Preferably, multiple horizontal frame members (54) (two in this case) are attached between the left and right vertical frame members (51) at intervals in the front-to-back direction. The horizontal frame members (54) are, for example, hollow with a roughly rectangular cross-section. Magnets (56) are attached to both the left and right ends of the front side of the front horizontal frame material (54). The top plate material consists of a first top plate material (52A) positioned at the front end of the fixed slope plate (5) and having a flange portion (521) at its front edge, a second top plate material (52B) positioned in the middle of the length of the fixed slope plate (5), and a third top plate material (52C) ​​positioned at the rear end of the fixed slope plate (5). In this embodiment, these first to third top plate materials (52A)(52B)(52C) ​​of the fixed slope plate (5) have the same shape and structure as the first to third top plate materials (32A)(32B)(32C) of the variable slope plate (3), thereby reducing the number of component types and lowering costs. However, it is of course possible to have a top plate material of the fixed slope plate (5) have a different shape and structure from the top plate material of the variable slope plate (3). Furthermore, drainage holes (522) may be provided in the third top plate material (52C) ​​as needed. Also, similar to the variable slope plate (3), female threaded members (55) into which bolts (53) are screwed are placed inside both the left and right ends of each top plate material (52A), (52B), and (52C), and are joined and fixed by rivets (not shown).

[0031] The fixed ramp plate (5) is rotatably connected at its front end to the rear end of the base frame (2) around a pivot axis extending in the left-right direction. More specifically, the connecting protrusions (511) of each left and right vertical frame (51) of the fixed ramp plate (5) are rotatably connected to the lower rear end of the vertical wall portion (212) of each left and right vertical frame (21) of the base frame (2) by bolts (57) and nuts (58).

[0032] The support unit (4) includes a screw shaft (41) that extends in the front-rear direction and is rotatably attached to the base frame (2) about its axis, a feed nut (42) that is screwed onto the screw shaft (41) and moves in the front-rear direction as the screw shaft (41) rotates, support arms (43A) (43B) one end of which is rotatably connected to the feed nut (42) and the other end of which is rotatably connected to the variable slope plate (3), and a rotation operating part (44) for rotating the screw shaft (41).

[0033] The screw shaft (41) is made of a metal rod-shaped body on which a male thread of the required shape (for example, a trapezoidal thread) is formed on its surface. The screw shaft (41) is attached to the base frame (2) so as to be located below the center of the left-right width of the variable ramp plate (3). More specifically, the screw shaft (41) is rotatably mounted across the center of the length of the front transverse frame (22A) and the intermediate transverse frame member (22B) of the base frame (2). The rear end of the screw shaft (41) consists of a small-diameter shaft portion (411) on which no male threads are formed. The intermediate horizontal frame material (22B) and the reinforcing core material (23) fitted therein have insertion holes (223) and (231) in the center of the left-right length of their front walls. A reinforcing plate (26) having an insertion hole (261) that matches the insertion holes (223) and (231) is joined and fixed to the center of the length of the front wall surface of the intermediate horizontal frame material (22B) by screws or the like. The small-diameter shaft portion (411) of the screw shaft (41) is rotatably inserted into these insertion holes (223), (231), and (261) via a washer (412). Through holes are made in the length center of the front and rear walls of the front lateral frame (22A), and screw shaft insertion collars (27) extending in the front-rear direction are fitted into these through holes. In addition, a reinforcing plate (28) having a through hole (281) that matches the rear end opening of the collar (27) is joined and fixed to the length center of the rear surface of the rear wall of the front lateral frame (22A) with screws or the like. The screw shaft (41) is inserted from the front through the through hole (281) of the collar (27) and reinforcing plate (28), and as described above, the small-diameter shaft portion (411) at its rear end is inserted into the insertion holes (223), (231), and (261) of the intermediate horizontal frame material (22B), reinforcing core material (23), and reinforcing plate (26). In this state, the front end of the screw shaft (41) protrudes forward from the front horizontal frame (22A) and is positioned near the lower part of the front end of the variable slope plate (3) (see Figure 2). Furthermore, a horizontal cylindrical stopper (413) is fitted over the front end portion of the screw shaft (41), and the two (41) and (413) are joined together by a connecting pin (414), such as a spring pin, which passes through them radially. This stopper (413) has the function of preventing the screw shaft (41) from moving forward and falling off the base frame (2), and also has the function of restricting the forward movement range of the feed nut (42). A bolt (415) is passed through the front end of the screw shaft (41) in a radial direction, and a nut (416) is screwed onto the tip of the bolt (415). These bolts (415) and nuts (416) function as finger grips (auxiliary rotational operation parts) for manually rotating the screw shaft (41) when, for example, an electric rotary tool that can be connected to a rotary operation part (44) consisting of a rotary operation head, described later, is not available.

[0034] The feed nut (42) is, for example, made of a metal block body with a roughly rectangular cross-section that is long in the left-right direction, as shown in the figure, and has a screw hole (421) in the center of its length which has a female thread (for example, a trapezoidal thread) that is threaded with the male thread of the screw shaft (41). This feed nut (42) together with the screw shaft (41) constitutes a feed screw and is designed to move in the front-rear direction as the screw shaft (41) rotates. When moving in the front-rear direction, the feed nut (42) is designed to slide on the upper surface of the base plate material (25), more specifically, on a plurality of protrusions (252) formed on the upper surface. At both ends of the feed nut (42), roughly U-shaped arm connecting brackets (422) that open forward when viewed from a plane are joined and fixed.

[0035] The feed screw mechanism, consisting of a screw shaft and a feed nut, is not limited to the above-described configuration; other mechanisms, such as a ball screw mechanism, can also be applied.

[0036] The support arm in this embodiment consists of a left support arm (43A) whose one end is rotatably connected to the left half of the feed nut (42) and whose other end is rotatably connected to the left half of the variable slope plate (3), and a right support arm (43B) whose one end is rotatably connected to the right half of the feed nut (42) and whose other end is rotatably connected to the right half of the variable slope plate (3). As shown in Figure 4, each of the left and right support arms (43A) and (43B) is made of a roughly crank-shaped metal cylindrical body having a vertical lower end arm portion (431) and an upper end arm portion (432), and an intermediate arm portion (433) that extends diagonally upward in the left-right direction outward to connect these (431) and (432). The lower arm portion (431) is rotatably attached by connecting bolts (434) to arm connecting brackets (422) provided on the left and right sides of the feed nut (42). The upper arm portion (432) is rotatably attached by connecting bolts (435) and nuts (436) to arm connecting brackets (341) provided on the left and right ends of the front horizontal frame member (34A) of the variable slope plate (3). The lower ends of the left and right support arms (43A) (43B) may be attached to the end faces of the left and right halves of the feed nut (42) as shown in the figure, or they may be attached to the upper surface or front surface of the left and right halves of the feed nut (42). Furthermore, the mounting positions of the upper ends of the left and right support arms (43A) (43B) to the left and right halves of the variable slope plate (3) are not limited to those shown, and may be inward or outward from those positions. As the screw shaft (41) rotates, the feed nut (42) moves in the front-to-back direction, which changes the inclination angle of the left and right support arms (43A) (43B), thereby changing the inclination angle of the variable slope plate (3). In addition to being composed of two support arms (43A) and (43B) on the left and right sides as in the above embodiment, the support arm may also be composed of a single support arm whose upper end connected to the variable slope plate (3) is branched into two or three or more parts, or it may be composed of three or more support arms. In another embodiment, a plurality of feed nuts may be screwed onto a screw shaft, and the lower end of one or more support arms may be rotatably connected to each feed nut, and the upper end of each support arm may be rotatably connected to a required location on the variable slope plate.

[0037] The rotating operation unit (44) is located at the front end of a screw shaft (41) that protrudes near the lower part of the front end of the variable slope plate (3). The rotary operation unit preferably consists of a rotary operation head (44) that can be connected to an electric rotary tool (D) such as an impact driver. More specifically, the rotary operation head (44) is composed of, for example, a hexagonal nut (nominal diameter M10) attached to the front end of a screw shaft (41). With this configuration, the rotation operation of the screw shaft (41) for adjusting the inclination angle of the variable slope plate (3) can be performed very easily and quickly using an electric rotary tool (D).

[0038] Next, an example of the installation procedure for the ramp device (1) described above will be explained. First, the base frame (2) and fixed ramp plate (5) of the ramp device (1) are placed on the lower surface (G2) of the passageway. Next, the inclination angle of the variable slope plate (3) is adjusted so that the vertical distance between the front end of the variable slope plate (3), that is, the flange portion (321) of the first upper plate material (32A) and the lower step surface (G2), is approximately equal to the height of the step (G3). Specifically, the tip of the electric rotary tool (D) is connected to the rotation operation head (44) of the support unit (4), and the electric rotary tool (D) is driven so that the screw shaft (41) rotates by the required amount in the required rotation direction. As a result of the rotation of the screw shaft (41), the feed nut (42) moves by the required distance in either the forward or backward direction, thereby changing and adjusting the inclination angles of the left and right support arms (43A) (43B), and consequently the variable slope plate (3) is set to the required inclination angle. Finally, the installation of the ramp device (1) is completed by adjusting the position of the ramp device (1) so that the flange portion (321) of the variable ramp plate (3) is hooked onto the rear edge of the upper surface (G1). In this way, the upper surfaces of the variable ramp plate (3) and the fixed ramp plate (5) form ramp surfaces (30) and (50) that can eliminate the step difference (G3) between the upper surface (G1) and the lower surface (G2).

[0039] As described above, with the ramp device (1) of this embodiment, the inclination angle of the variable ramp plate (3) can be adjusted to match the height of the step (G3) at the installation site simply by rotating a single screw shaft (41). Furthermore, this rotation operation can be performed very easily and quickly from the front of the ramp device (1) using an electric rotary tool (D) connected to the rotation operation head (44) at the front end of the screw shaft (41), without having to reach deep under the variable ramp plate (3). Thus, the effort and time required for operation are greatly reduced.

[0040] Figure 7 shows the slope device (1) in the folded state. The illustrated ramp device (1) is modified from the installation state shown in Figures 1 to 4 by inverting the fixed ramp plate (5) so that it overlaps the lower surface of the base frame (2), and by rotating the screw shaft (41) of the support unit (4) to change and adjust the inclination angle of the variable ramp plate (3) to the minimum (approximately 0° relative to the horizontal plane in the figure). In this folded state, the ramp device (1) is significantly smaller in overall length and height compared to its installed state, resulting in a compact form that is easy to transport and requires less storage space. In particular, if the components of the base frame (2), the variable ramp plate (3), and the fixed ramp plate (5) are made of aluminum alloy, the overall weight of the ramp device (1) is significantly reduced without compromising the required load-bearing strength. This makes it possible, for example, for a worker to carry the ramp device (1) while holding the handle (6), greatly improving its handling capabilities. Furthermore, in the case of the ramp device (1) of this embodiment, when folded, the magnetic attachment parts (29) made of a magnetic material such as steel, provided at the rear end of the lower surface of the base frame (2), are magnetically attached to the left and right magnets (56) provided on the back side of the fixed ramp plate (5). More specifically, steel screws (29) (see Figure 5, etc.) that are screwed to the rear ends of the horizontal wall portions (211) of each of the left and right vertical frames (21). Therefore, when transporting the ramp device (1), for example, the fixed ramp plate (5) is prevented from swinging unintentionally, and transportation work can be carried out without hindrance.

[0041] [Second Embodiment] Figures 8-10 show a ramp device according to a second embodiment of this invention. The ramp device (1X) of this embodiment has substantially the same configuration as the ramp device (1) of the first embodiment shown in Figures 1 to 7, except for the following points, and achieves substantially the same effects as the ramp device (1). In other words, in the slope device (1X) of the second embodiment, the support unit (4X) further has a left-hand rotating shaft (45) for power transmission. The left-hand rotating shaft (45) is made of a metal rod-shaped body extending in the left-right direction, and its right end is connected to either the front or rear end (front end in the figure) of the screw shaft (41) via a gear mechanism (417) (451) so as to be interlocking, and its left end is rotatably mounted on the base frame (2) about its axis so as to protrude near the lower part of the left edge of the variable slope plate (3). A rotational operating part (44) is provided at the left end of the left-hand rotating shaft (45). Although not shown in the diagram, a right-hand drive shaft may be provided instead of the left-hand drive shaft (45), or in addition to the left-hand drive shaft (45), which extends in the left-right direction, has its left end connected to either the front or rear end of the screw shaft (41) via a gear mechanism so as to be interlocked, and has its right end protruding near the lower right edge of the variable slope plate (3). This right-hand drive shaft is rotatably mounted on the base frame (2) around its axis, and a rotation operation part may be provided at the left end of the right-hand drive shaft. In particular, if both the left-hand drive shaft (45) and the right-hand drive shaft are provided, the operator can rotate the screw shaft (41) from a desired direction depending on the installation environment of the slope device (1), for example, further improving convenience.

[0042] The front lateral frame member (22X) of the base frame (2) has an L-shaped cross-section, with a horizontal wall section (224) and a vertical wall section (225) extending upward from the rear edge of the horizontal wall section (224). A vertical retaining wall (226) is formed on the upper surface of the horizontal wall (224) at a required position along its length (slightly to the left of the center in the figure), which has an insertion hole (not shown) through which a left-rotating shaft (45) for power transmission is inserted. An insertion hole (not shown) is formed in the center of the vertical wall portion (225) through which the screw shaft (41) is inserted.

[0043] The front end of the screw shaft (41) protrudes forward from the vertical wall portion (225). A first bevel gear (417) is provided at the front end of the screw shaft (41) as a component of the gear mechanism.

[0044] A second bevel gear (451) that meshes with a first bevel gear (417) is provided at one end (right end) of the left-hand rotating shaft (45) for power transmission, which protrudes inward in the left-right direction from the retaining wall (226). The left portion of the left-rotating shaft (45) for power transmission is inserted into a through-hole (not shown) formed in the front end of the vertical wall portion (212) of the left vertical frame member (21) in the base frame (2). With this configuration, the left end of the left-rotating shaft (45) for power transmission is made to protrude near the lower part of the left edge of the variable slope plate (3). Furthermore, the left-hand rotating shaft (45) for transmission is provided with a spring-retaining flange (452) made of an E-ring or the like at a predetermined location adjacent to the left side surface of the retaining wall (226), and a spring (46) is externally fitted between the flange (452) and the vertical wall (212) of the left vertical frame member (21). The left-hand rotating shaft (45) for transmission is biased to the right by the spring elastic force (biasing force) of the spring (46), thereby maintaining the meshing state between the second bevel gear (451) and the first bevel gear (417). In addition, by bringing the spring-retaining flange (452) into contact with the left side surface of the retaining wall (226), the biasing force from the spring (46) is restricted so as not to be applied to the second bevel gear (451) and the first bevel gear (417) more than necessary. Therefore, with the above configuration, the rotational force of the left-hand drive shaft (45) is reliably transmitted to the screw shaft (41) via the second bevel gear (451) and the first bevel gear (417), so that the screw shaft (41) can be rotated reliably and smoothly in conjunction with the left-hand drive shaft (45).

[0045] The rotational operating section provided at the left end of the left rotational shaft (45) for power transmission is preferably composed of a rotational operating head (44) (for example, a hexagonal nut with a nominal diameter of M10) that can be connected to an electric rotary tool (D) such as an impact driver, similar to the first embodiment. Furthermore, a bolt (415) is passed radially through the left end of the left-hand rotating shaft (45) for power transmission, and a nut (416) is screwed onto the tip of the bolt (415). These bolts (415) and nuts (416) can function as finger grips (auxiliary rotational operating parts) for manually rotating the left-hand rotating shaft (45) for power transmission and the screw shaft (41) connected to it.

[0046] According to the ramp device (1X) of this embodiment, the rotation of the screw shaft (41) for adjusting the inclination angle of the variable ramp plate (3) can be performed very easily from the side of the ramp device (1X) using an electric rotary tool (D) without having to reach deeply under the variable ramp plate (3), resulting in excellent operability. In particular, this operation can be performed with the ramp device (1X) positioned so that the front end of the variable ramp plate (3), i.e., the flange portion (321) of the first upper plate material (32A), is close to the step (G3), making the adjustment of the inclination angle of the variable ramp plate (3) even easier.

[0047] Although not shown in the diagram, multiple ramp devices (1)(1X) of the above embodiments may be installed side by side in the left-right direction, thereby forming a wide ramp surface for, for example, a material handling vehicle such as a forklift to overcome the step (G3). [Industrial applicability]

[0048] This invention can be suitably used, for example, in various work sites, factory facilities, logistics facilities, etc., as a ramp device to form a ramp surface to eliminate steps in the passageways where transport carts, cargo handling vehicles, etc. move. [Explanation of symbols]

[0049] (1)(1X): Slope device (2): Base frame (3): Adjustable ramp board (30): Slope surface (31): Vertical frame material (32A)(32B)(32C):Top plate material (33): Bolt (4)(4X): Support unit (41): Screw shaft (417): First bevel gear (gear mechanism) (42): Feed nut (43A): Left support arm (43B): Right support arm (44): Rotary operation head (rotary operation unit) (45): Left-hand rotating shaft for power transmission (451): Second bevel gear (gear mechanism) (5): Fixed ramp board (50): Slope surface (D): Electric rotary tools (G1): Upper surface (G2):Lower side (G3): Step

Claims

[Claim 1] A slope device for eliminating a step occurring between an upper surface of a passage and a lower surface located behind the upper surface of the passage, a base frame disposed on the lower surface; a variable slope plate whose rear end is rotatably connected to the base frame and whose upper surface forms a slope surface; a support unit provided between the base frame and the variable slope plate and supporting the variable slope plate so that the inclination angle of the variable slope plate can be adjusted; The support unit is a slope device having a screw shaft extending in the front-to-rear direction and rotatably attached to the base frame around its axis, a feed nut screwed onto the screw shaft and moved in the front-to-rear direction as the screw shaft rotates, a support arm having one end rotatably connected to the feed nut and the other end rotatably connected to a variable slope plate, and a rotation operating unit for rotating the screw shaft.

Images