Suspended door device

Abstract

To provide a suspended door device capable of keeping the outer diameter of a wire at a predetermined value.SOLUTION: This hanging door device 10 is provided with a pair of right and left groove-shaped rails 21, a door 22 vertically movably guided by these groove-shaped rails 21, a wire 23 for hanging this door 22, and an electric chain block 30 for pulling up this wire 23, and is provided with a safety bar 41 inserted under the door 22 when the door 22 exists in an ascending limit position and preventing falling of the door 22. It is not necessary to make the wire 23 excessively thick, and the outer diameter of the wire 23 can be kept at a predetermined value.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a hanging door device having a simple structure and suitable for use in warehouses. [Background technology]

[0002] The warehouse has a large entrance and exit that allows vehicles such as forklifts and trucks to pass through. This doorway is generally closed with a sliding or hanging door. Various types of suspension door support structures suitable for warehouses have been proposed (see, for example, Patent Document 1 (FIG. 4)).

[0003] The suspension door support structure of Patent Document 1 has a rail laid horizontally on the upper edge of the entrance, and a suspension door is suspended from this rail via rollers. The suspension door opens and closes the entrance by being pulled sideways.

[0004] Such a hanging door support structure is widely used in warehouses. However, if the horizontal rails bend, it becomes difficult for the rectangular door to move sideways, so the rails must be sufficiently rigid, which results in the rails becoming larger and heavier. To install such large and heavy rails, the warehouse, especially the area around the entrances and exits, needs to be sufficiently rigid.

[0005] By the way, agricultural warehouses are essential for farmers to store crops, fertilizer, agricultural equipment, etc. Agricultural warehouses can be simpler in construction than industrial warehouses that are equipped with overhead cranes, etc. Simple warehouses include barns for housing livestock and general light warehouses for storing goods. The hanging door support structure of Patent Document 1 is suitable for industrial warehouses (or sturdy warehouses), but cannot be said to be suitable for warehouses with simple construction.

[0006] Therefore, the present applicant proposed a livestock barn as previously disclosed in Patent Document 2, and attached a simple hanging door device to this livestock barn. A typical example of a livestock barn is a cow barn. A cowshed is a large building because it houses a large number of cows. The construction and maintenance costs of buildings affect the prices of milk and beef, so livestock sheds must be simple in structure.

[0007] For this reason, in the livestock barn disclosed in Patent Document 2, the doors are raised and lowered using wires and electric chain hoists. Wires and electric chain hoists are easily available and inexpensive. Because they are inexpensive, they can help reduce the construction and maintenance costs of the building.

[0008] However, the surface of the wire will fray after long-term use. If the fraying progresses, the wire will break. It is necessary to replace the wire before it breaks. However, because the barns are large, the wires are located high up, making visual inspection difficult.

[0009] By making the wire thicker than a predetermined value, the interval between replacements can be extended and inspections can be reduced. The predetermined value is a design value that takes into account a set safety margin. However, using a thicker wire increases the cost of procuring the wire, and the weight of the wire increases, which increases the electricity bill for the electric chain hoist.

[0010] As there is a demand for reducing construction and maintenance costs, there is a demand for a hanging door device that can keep the outer diameter of the wire at a predetermined value. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-132087 [Patent Document 2] Utility Model Registration No. 3193062 Summary of the Invention [Problem to be solved by the invention]

[0012] An object of the present invention is to provide a hanging door device that can keep the outer diameter of the wire at a predetermined value. [Means for solving the problem]

[0013] The invention according to claim 1 is a suspended door device comprising a pair of left and right grooved rails that are U-shaped in plan view and arranged vertically, a door that is guided by these grooved rails so as to be able to move up and down, a wire that suspends the door, and an electric chain block that pulls up the wire, This hanging door device is characterized by further comprising a door fall prevention mechanism that is inserted under the door when the door is at its uppermost position to prevent the door from falling.

[0014] The invention according to claim 2 is the hanging door device according to claim 1, The door is provided with a rotatable free roller, and the door is guided by the grooved rail via the free roller.

[0015] The invention according to claim 3 is the hanging door device according to claim 1 or claim 2, The door fall prevention mechanism is characterized by comprising a vertically long safety bar that moves in and out of the groove of at least one of the pair of grooved rails, a hinge that rotatably engages the safety bar with the grooved rail, and a handle attached to the safety bar that is grasped by a worker standing on the floor.

[0016] The invention according to claim 4 is the hanging door device according to claim 3, The safety bar is said to be in a set position when it is in the groove of the grooved rail, and is said to be in a standby position when it is out of the groove of the grooved rail, and the rotation angle of the safety bar from the set position to the standby position is in the range of 260° to 280°.

[0017] The invention according to claim 5 is the hanging door device according to claim 3, The safety bar is said to be in a set position when it is in the groove of the grooved rail, and is said to be in a standby position when it is out of the groove of the grooved rail. The electric chain hoist is characterized by comprising a limit switch which permits operation of the electric chain hoist when the safety bar is in the standby position and prohibits operation of the electric chain hoist when the safety bar is in the set position.

[0018] The invention according to claim 6 is the hanging door device according to claim 3, The safety bar is a square steel pipe of a size that fits into the groove of the channel rail. [Effects of the Invention]

[0019] The invention according to claim 1 is provided with a door fall prevention mechanism that prevents the door from falling when the door is at its uppermost position. As part of cost reduction efforts, doors are suspended by inexpensive wires. There is concern that the wires may become loose and break over time. However, the present invention is equipped with a door fall prevention mechanism, which prevents the door from falling even if the wire breaks. Since the door drop prevention mechanism is provided, there is no need to make the wire excessively thick, and the outer diameter of the wire can be kept at a predetermined value. As a result, the present invention provides a hanging door device that can keep the outer diameter of the wire at a predetermined value.

[0020] In the invention according to claim 2, the door is guided by the grooved rail via free rollers. The presence of the free rollers allows the door to be raised and lowered more smoothly and reduces the load on the wire.

[0021] In the invention according to claim 3, the door fall prevention mechanism comprises a vertically long safety bar, a hinge that engages the safety bar with the grooved rail, and a handle that an operator grips with his / her hand. The safety bar eliminates the need to provide a notch in the web of the channel rail. Without the notch, the free roller can rotate along the web of the channel rail.

[0022] Furthermore, although it is possible to add an electric actuator and rotate the safety bar using this electric actuator, this would increase the cost of the device and running costs such as electricity bills. In the present invention, the safety bar is manually rotated, which reduces the installation and running costs of the hanging door device.

[0023] In the invention according to claim 4, the safety bar is rotated by approximately 270°. In the set position, the safety bar can be placed fully into the groove of the grooved rail. In the standby position, the safety bar can be placed along the flange of the channel rail. In both the installed and standby positions, the safety bar is positioned out of the way.

[0024] In the invention according to claim 5, when the safety bar is in the groove of the grooved rail, the operation of the electric chain hoist is prohibited, thereby preventing erroneous operation by the operator.

[0025] In the invention according to claim 6, the safety bar is a square steel pipe. Square steel pipes are compatible with the grooves of channel rails. In addition, inexpensive commercially available square steel pipes can be used. [Brief explanation of the drawings]

[0026] [Figure 1] 1 is a partial view of a warehouse equipped with a hanging door device according to a first embodiment of the present invention (a view of the entrance / exit from inside the warehouse). [Figure 2] 2(a) is an enlarged view of part 2a in FIG. 1, and FIG. 2(b) is a view taken along the arrow bb in FIG. 2(a). [Figure 3] 3A is a cross-sectional view taken along line 3a-3a in FIG. 2, and FIGS. 3B to 3D are diagrams illustrating the pivoting operation of the safety bar. [Figure 4] (a) to (c) are diagrams explaining the operation of the limit switch, (d) is a cross-sectional view taken along line 4d-4d in Figure 2, and (e) to (f) are diagrams explaining the action of the kick bar attached to the safety bar. [Figure 5] FIG. 1 is a diagram illustrating the configuration of an electric chain block. [Figure 6] FIG. 10 is a flow chart illustrating the operation of the door according to the present invention when it moves from a closed position to an open position. [Figure 7] FIG. 10 is a flow chart illustrating the operation of the door according to the present invention when it moves from an open position to a closed position. [Figure 8] FIG. 10(a) is an enlarged view of a main part of a suspended door device according to a second embodiment of the present invention, and (b) is a perspective view of part b in (a). [Figure 9] FIG. 10 is a configuration diagram of an electric chain block according to a second embodiment. [Figure 10] FIG. 10 is an enlarged view of a main part of a suspended door device according to a third embodiment of the present invention. [Figure 11] FIG. 10 is a configuration diagram of an electric chain block according to a third embodiment. [Figure 12] FIG. 10(a) is an enlarged view of a main part of a suspended door device according to a fourth embodiment of the present invention, and FIG. 10(b) is a view for explaining the operation of the fourth embodiment. [Figure 13] 5A is an enlarged view of the main part of the hanging door device according to the fifth embodiment of the present invention, FIG. 5B is a view taken along the arrow b in FIG. 5A, FIG. 5C is an operational diagram of the fifth embodiment, and FIG. 5D is a view taken along the arrow c in FIG. [Figure 14] This is a partial view of a warehouse with double doors (view of the entrance and exit from inside the warehouse). [Figure 15] FIG. DETAILED DESCRIPTION OF THE INVENTION

[0027] An embodiment of the present invention will be described below with reference to the accompanying drawings. [Example]

[0028] [warehouse] As shown in Fig. 1, the warehouse 10 has a large entrance 11 that is 3m to 8m wide and 3m to 5m high. The entrance 11 is closed by a door 22 that is a horizontally long rectangle.

[0029] The warehouse 10 is preferably an agricultural warehouse for storing agricultural equipment, crops, and other agricultural items. An industrial warehouse is a sturdy building equipped with an overhead crane, for example. Agricultural warehouses do not require the same sturdiness as industrial warehouses. Therefore, agricultural warehouses are buildings with simple structures. Therefore, a simple door 22 will suffice. In addition to an agricultural warehouse, the warehouse 10 may also be a fishing warehouse, a large barn, or a general light warehouse. The warehouse 10 may also be a barn for keeping cows or horses.

[0030] [Hanging door device] The door 22 is large and heavy enough that it cannot be opened or closed by human effort, so a hanging door device 20 is required. The suspended door device 20 comprises a pair of left and right grooved rails 21 aligned along building-side support pillars 12 located on the left and right sides of the entrance 11, a door 22 guided by these grooved rails 21 so that it can move up and down, a wire 23 for suspending the door 22, and an electric chain hoist 30 for pulling up the wire 23. The structure of the electric chain hoist 30 will be described later, but an easily available, inexpensive commercially available product may be used. The electric chain block 30 raises the door 22 to the upper limit position shown by the imaginary line.

[0031] [Door fall prevention mechanism] The wire 23 deteriorates with use. Therefore, the present invention is provided with a door fall prevention mechanism (see FIG. 2(a), reference numeral 40) that is inserted under the door 22 to prevent the door 22 from falling when the door 22 is in the uppermost position (see FIG. 1, the position shown by the imaginary line).

[0032] 2(a), the door fall prevention mechanism 40 comprises a vertically long safety bar 41 that moves in and out of the groove of the grooved rail 21, a hinge 42 that rotatably engages the safety bar 41 with the grooved rail 21, and a U-shaped handle 43 that is attached to the safety bar 41 and can be grasped by a worker standing on the floor 13. The safety bar 41 is shown in the middle of its rotation.

[0033] Furthermore, the grooved rail 21 and the safety bar 41 may be provided on both of the pair of left and right grooved rails 21, or on only one of them. If the wire 23 is managed properly, the frequency with which the safety bar 41 supports the door 22 is zero or very low, so it is acceptable to provide it on only one of them.

[0034] 2(a), preferably, a kick bar 44 is provided on the safety bar 41, and a limit switch 45 is provided on the support 12. However, the limit switch 45 and kick bar 44 may be omitted. The height H1 of the handle 43 above the ground is preferably about 1 m. The height H2 of the limit switch 45 above the ground is optional, but is preferably about 2 m.

[0035] The limit switch 45 may be an I-lever type limit switch, an L-lever type limit switch, or any other type of sensor, but in this first embodiment, an L-lever type limit switch 50 is used.

[0036] 2(b), the grooved rail 21 is made up of a pair of flanges 21a and a web 21b connecting one end of the pair of flanges 21a. The grooved rail 21 is also called a channel, and a thin, lightweight channel can be used.

[0037] Preferably, the door 22 is provided with a rotatable free roller 24, and the door 22 is guided by the grooved rail 21 via the free roller 24. The free rollers 24 rotate while traveling on the web 21b, allowing the door 22 to move smoothly up and down. However, the free rollers 24 may be omitted.

[0038] [Safety bar] The safety bar 41 is a member that supports the falling door 22, and may be a round bar, a square bar, a round steel pipe, or a square steel pipe. As shown in FIG. 3( a ), the safety bar 41 is recommended to be a square steel pipe 47 of a size that fits into the groove of the channel rail 21 . For the square steel pipe 47, a general structural square steel pipe specified in JIS G 3466 can be used.

[0039] [Safety bar operation] As shown in FIG. 3( a ), one blade of the hinge 42 is welded to the outer surface of the flange 21 a of the channel rail 21 , and the other blade is welded to a square steel pipe 47 . In Figure 3(a), when the square steel pipe 47 is rotated 90 degrees clockwise as shown by the arrow (1), it reaches Figure 3(b), in which the safety bar 41 is in the set position.

[0040] In Figure 3(b), metal-to-metal contact (hereinafter referred to as metal touch) prevents the square steel pipe 47 from rotating any further clockwise. This makes it easy to rotate the pipe by gripping the handle 43. This is because the worker can simply release the handle 43 when the pipe can no longer be rotated.

[0041] The hinge 42 is not limited to a hinge in the strict sense. For example, it may be a hinge in the form of a round bar welded to the square steel pipe 47, a round pipe welded to the outer surface of the flange 21a of the channel rail 21, and a round bar inserted into the round pipe from above. In other words, the hinge 42 may be either a hinge with wings or a hinge without wings. However, hinges are recommended because there are a wide variety of types, they are easy to obtain, and they are inexpensive.

[0042] In Figure 3(b) (set position), the square steel pipe 47 blocks the groove of the channel rail 21. In this state, if the door were to be lowered from the front to the back of the drawing, the door would rest on the square steel pipe 47 and would not be able to be lowered any further.

[0043] In Figure 3(a), when the square steel pipe 47 is rotated 90° counterclockwise as shown by arrow (2), it reaches Figure 3(c), and when the square steel pipe 47 is rotated another 90° counterclockwise as shown by arrow (3) in Figure 3(c), it reaches Figure 3(d), where the safety bar 41 is in the standby position.

[0044] In Figure 3(d), the square steel pipe 47 cannot be rotated further counterclockwise due to metal contact. This makes it easy to rotate the pipe by gripping the handle 43. This is because the worker can simply release the handle 43 when the pipe can no longer be rotated.

[0045] In FIG. 3(d), the groove of the grooved rail 21 is open, so that the door can move up and down. In addition, in Figures 3(a) and 3(c), the square steel pipe 47 is rotating. Therefore, it is held in the state shown in Figure 3(b) or Figure 3(d). In Figures 3(b) and 3(d), the square steel pipe 47 does not get in the way.

[0046] [Safety bar rotation angle] The safety bar 41 rotated 90° from Fig. 3(b) to Fig. 3(a), rotated 90° from Fig. 3(a) to Fig. 3(c), and rotated 90° from Fig. 3(c) to Fig. 3(d). Assuming that the angle error in Fig. 3(b) is 5° and the angle error in Fig. 3(d) is 5°, the rotation angle of the safety bar 41 from the set position to the standby position is in the range of 260° to 280°.

[0047] As mentioned above, in Figures 3(b) and 3(c), the safety bar 41 is stable due to metal-to-metal contact. In other words, the worker holding the handle 43 simply rotates the safety bar 41 clockwise or counterclockwise until metal contact is achieved, making the work extremely easy. Therefore, the recommended rotation angle of the hinge 42 is in the range of 260° to 280°.

[0048] [Limit switch] As mentioned above, the limit switch can be any of an I-lever type limit switch, an L-lever type limit switch, and other sensors, but in this example, an L-lever type limit switch is used.

[0049] 4(a), the L-shaped lever limit switch 50 mainly comprises a housing 51 that houses a microswitch and a spring, and an L-shaped lever 52 that switches the microswitch. The L-shaped lever 52 has a first arm 53 and a second arm 54.

[0050] The kick bar 44 points towards the L-shaped lever 52 as shown by the arrow. Then, the kick bar 44 hits the first arm 53, rotating the L-shaped lever 52 counterclockwise in the drawing. As shown in FIG. 4(b), when the L-shaped lever 52 is rotated by a predetermined angle, the force of the spring built into the housing 51 causes the L-shaped lever 52 to automatically rotate counterclockwise in the drawing, as shown in FIG. 4(c). In FIG. 4(c), the first arm 53 is horizontal and the second arm 54 is vertical.

[0051] When the kick bar 44 moves to the right in FIG. 4(c), the second arm 54 is pushed, and the movement returns to FIG. 4(a) via FIG. 4(b). FIG. 4(b) is a transitional state diagram, and the L-lever limit switch 50 is held in either the state shown in FIG. 4(a) or FIG. 4(c).

[0052] For this reason, the L-lever limit switch 50 is also called a holding type limit switch. While an I-lever limit switch requires a holding relay, the L-lever limit switch 50 has the advantage of not requiring a holding relay.

[0053] For convenience of the following explanation, it is assumed that the L-shaped lever limit switch 50 issues "operation permission information" in FIG. 4(a) and "operation prohibition information" in FIG. 4(c).

[0054] FIG. 4(d) is a diagram corresponding to FIG. 3(a), FIG. 4(e) is a diagram corresponding to FIG. 3(c), and FIG. 4(f) is a diagram corresponding to FIG. 3(d). In FIG. 4(d), the kick bar 44 rotates as indicated by the arrow (4), and in FIG. 4(e), the kick bar 44 rotates as indicated by the arrow (5), causing the kick bar 44 to push the first arm 53, resulting in the state shown in FIG. 4(f).

[0055] That is, in Figures 4(d) to 4(e), the L-shaped lever type limit switch 50 is maintained in the state of Figure 4(a), and in Figure 4(f), the L-shaped lever type limit switch 50 is maintained in the state of Figure 4(c).

[0056] In Figure 4(f), the kick bar 44 is returned as shown by arrow (6), and the L-shaped lever limit switch 50 in the state of Figure 4(c) switches to Figure 4(a) via Figure 4(b).

[0057] [Electric chain hoist] As shown in Figure 5, the electric chain block 30 comprises a tune 31, a chain sheave 32 to which the tune 31 is applied, an electric motor 33 to rotate the chain sheave 32, an electromagnetic brake 34 and a mechanical brake 35 to brake the chain sheave 32, a push button switch 36, and a switch box 37 to be interposed in the electrical system from the push button switch 36 to the electric motor 33.

[0058] To this switch box 37, an L-shaped lever type limit switch 50 sends "operation permission information" or "operation prohibition information". When the "operation permission information" is being sent, the door 22 can be moved up or down via the wire 23 by operating the push button switch 36. When the "operation prohibition information" is being sent, operation of the push button switch 36 is invalid and the door 22 remains stopped.

[0059] The operation of the above-described suspended door device 20 will be described with reference to FIGS. At step number (hereinafter abbreviated as ST) 01 in Figure 6, the door is in the fully closed position, the safety bar is in the standby position (Figure 3(d)), and the limit switch is issuing an "operation permission information" (Figure 4(a)). In ST02, the worker opens the door using the push button switch (Figure 5, reference numeral 36), which causes the door to rise. In ST03, when the door reaches its upper limit, the operation stops. This stops the door and opens it fully.

[0060] At ST04, the worker rotates the safety bar to the set position (Fig. 3(d) → (c) → (a) → (b)). This rotation completes the door fall prevention measures. As shown in ST05, at this time the limit switch is switched to issue an "operation prohibition information" (Fig. 4(c)). In this state, even if an operator attempts to open or close the door, they will not be able to do so. ST06 is where cargo and other items are loaded and unloaded.

[0061] As shown in ST11 in Figure 7, at this time, the door is in the fully open position, the safety bar is in the set position (Figure 3(b)), and the limit switch is issuing an "operation prohibited information" (Figure 4(c)). Before closing the door, the worker rotates the safety bar to the standby position at ST12 (Fig. 3(b) → (a) → (c) → (d)). This rotation releases the door fall prevention measures. As shown in ST13, at this time, the limit switch is switched to issue "operation permission information" (Fig. 4(a)). In this state, the door can be opened and closed.

[0062] In ST14, the worker closes the door, which causes the door to descend. In ST15, when the door reaches the closed position, the operation stops. As a result, the entrance / exit is fully closed.

[0063] [Actions and Effects of the First Example] The functions and effects of the first embodiment described above are as follows. First, a safety bar is placed under the door when it is at its highest position, preventing the door from dropping even if the wire loosens. Because measures to prevent the door from falling are in place, there is no need to use an excessively thick wire, and the appropriate thickness can be used.

[0064] However, if the door is lowered with the safety bar still in place, the safety bar will prevent the door from descending. As a result, the wire will loosen and come off the hook of the electric chain hoist. This will require a lot of work to restore the door. This is no longer a concern with the first embodiment.

[0065] Secondly, the limit switch is set to issue either "operation permitted" or "operation prohibited" information, and when the safety bar is in the set position, it issues the "operation prohibited" information. When the safety bar is in the set position, the door does not lower. The wire is always under tension, so it will not loosen or come off the hook.

[0066] Third, the free rollers (24 in Figure 2(b)) placed between the door and the grooved rail make raising and lowering the door extremely smooth. As a result, the load on the wire and electric chain hoist is reduced, and the frequency of inspection and replacement of the wire and electric chain hoist can be reduced.

[0067] Another embodiment of the first embodiment described above will be described below.

[0068] [Second Example] As shown in Figure 8(a), the door drop prevention mechanism 40 consists of a safety bar 41, a hinge 42, a handle 43, and a load cell 56 attached to the upper surface of the safety bar 41. The load cell 56 is preferably a piezoelectric element that generates electricity when pressure is applied.

[0069] As shown in FIG. 8(b), when the door 22 is placed on the load cell 56, the load cell 56 plays a role in transmitting that information to the outside.

[0070] As shown in Figure 9, a siren 38 is attached to the load cell 56. The siren 38 may be a bell, a flashing light, or a combination of these. When downward pressure is applied to the load cell 56, an alarm sounds. The alarm sounds, causing the worker to stop lowering the door 22. Next, the door 22 is raised by several tens of millimeters, and the safety bar 41 is moved to the standby position. The alarm sound only sounds if the safety bar 41 is forgotten to be returned to the standby position, and does not sound normally.

[0071] [Effects of the second embodiment] The limit switch 45 in the first embodiment can be replaced with a smaller, lighter and less expensive load cell 56. The load cell 56 may be an equivalent sensor.

[0072] [Third Example] As shown in FIG. 10, the door fall prevention mechanism 40 comprises a safety bar 41, a hinge 42, and a handle 43. The worker is required to keep a close eye on the behavior of the door 22 when opening and closing the door 22. If the door 22 hits the safety bar 41, a sound is generated. It is expected that the worker will notice an abnormality by this sound.

[0073] As shown in FIG. 11, the hanging door device 20 does not include a limit switch (FIG. 2, reference numeral 45) or a load cell (FIGS. 8(a) and (b), reference numeral 56).

[0074] [Effects of the third embodiment] Since the limit switch 45 and the load cell 56 are not used, the cost of the hanging door device 20 can be reduced.

[0075] In the first to third embodiments described above, the safety bar 41 extending along the grooved rail 21 is employed, but the greater the height dimension of the door 22, the longer the safety bar 41 becomes. If the length of the safety bar 41 is a concern, the following embodiment is recommended.

[0076] [Fourth Example] As shown in Figure 12(a), the door fall prevention mechanism 40 comprises a fan-shaped safety plate 58 that penetrates the web 21b of the grooved rail 21, a pin hinge 59 that secures the safety plate 58 to the grooved rail 21 so that the base of the fan becomes the center of rotation and allows it to rotate freely, a torsion spring 61 that urges the safety plate 58 into the groove of the grooved rail 21, a lever 62 extending from the safety plate 58, a first rod (or wire) 63 hanging from the lever 62, a turnbuckle 64 screwed into the lower end of the first rod 63, a second rod 65 hanging from the turnbuckle 64, a kicker 66 provided at the lower end of the second rod 65, a rotary joint 67 provided below the kicker 66, an L-shaped handle 68 hanging from the rotary joint 67, an operation plate 71 having a J-shaped groove 69 that guides the L-shaped handle 68, and a limit switch 45 provided on the operation plate 71.

[0077] The torsion spring 61 can also be changed to a tension spring or a compression spring.

[0078] The turnbuckle 64 has two female threads, one of which is a left-handed thread and the other a right-handed thread. Therefore, when the turnbuckle 64 is turned in one direction, the first rod 63 and the second rod 65 move closer to each other, and when the turnbuckle 64 is turned in the other direction, the first rod 63 and the second rod 65 move apart. As a result, position adjustment can be easily performed.

[0079] In FIG. 12(a), even if the door 22 were to drop, it would be received by the safety plate 58 in the set position and would be prevented from dropping any further. In addition, in FIG. 12(a), the limit switch 45 issues operation prohibition information.

[0080] Before lowering the door 22, the worker pushes down the L-shaped handle 68. This causes the safety plate 58 to rotate clockwise in the drawing via the first rod 63 and the second rod 65. As a result, as shown in Figure 12(b), the safety plate 58 moves to a standby position outside the channel rail 21. In this state, the limit switch 45 switches to issue an operation permission signal, and the door 22 can be raised or lowered.

[0081] The first and second rods 63, 65 and the L-shaped handle 68 are constantly pulled up by the biasing action of the torsion spring 61. By tilting the L-shaped handle 68 slightly to the left in the drawing, the L-shaped handle 68 is hooked onto the tip of the J-shaped groove 69. This maintains the state shown in FIG. 12(b).

[0082] In FIG. 12(b), the door 22 is lowered to the fully closed position. When opening the door 22, the L-shaped handle 68 is first tilted slightly to the right in the drawing. This causes the first rod 63, second rod 65, and L-shaped handle 68 to rise under the action of the torsion spring 61, causing the safety plate 58 to rotate counterclockwise in the drawing. The safety plate 58 passes through a notched hole 72 provided in the web 21b. Because the rotary joint 67 is interposed, the first and second rods 63, 65 will not be twisted even if the L-shaped handle 68 is tilted to the right in the drawing. As a result, there is a smooth return to Figure 12(a).

[0083] The safety plate 58 may be a horizontally extending safety rod that can enter and exit the groove of the channel-shaped rail 21 through the notched hole 72. Therefore, the shape of the safety plate 58 is not limited to that of the embodiment.

[0084] In this fourth embodiment, it is necessary to provide a notched hole 72 in the web 21b of the grooved rail 21. Because a free roller (24 in FIGS. 2(a) and 2(b)) would fall into (or get caught in) this notched hole 72, no free roller is provided on the door 22. In addition, a gap t is provided between the web 21b and the door 22. The existence of this gap t makes it possible to provide the notched hole 72.

[0085] Furthermore, when it is necessary to reduce the operating force of the operator resisting the spring force of the torsion spring 61, the following structure is recommended.

[0086] [Fifth Example] The L-shaped handle 68 in Figure 12(a) has been changed to a bar handle 73 in Figure 13(a). As the rest of the components are the same, the reference numerals in Figure 12(a) are used in Figure 13(a) and a detailed description of the structure will be omitted.

[0087] 13(a), the lower end of the second rod 65 is attached midway on the bar handle 73. Depending on the lever ratio, the operating force of the operator can be reduced to about 1 / 2 to 1 / 3 of the spring force of the torsion spring 61.

[0088] FIG. 13(b) is a view taken along the arrow b in FIG. 13(a), and the I-lever limit switch 75 issues operation prohibition information. FIG. 13(c) is an operational diagram of FIG. 13(a), and preparations for opening and closing the door 22 are made in the state shown in FIG. 13(c). FIG. 13(d) is a view seen from the arrow d in FIG. 13(c), and the I-lever limit switch 75 issues operation permission information.

[0089] In Figures 13(c) and (d), the closed door 22 can be raised to the upper limit position, and the door 22 at the upper limit position can be lowered to the closed position. As shown in Figures 13(a) and 13(b), the door 22 can be prevented from falling.

[0090] When the bar handle 73 is used, the torsion spring 61 can be omitted. This is because the first and second rods 63, 65 can be lifted by the bar handle 73 using the principle of leverage.

[0091] 1 has an entrance 11 that is about one-third the height of the building. If the entrance 11 is used as the reference, the height of the building is about three times the height of the entrance 11. Depending on the use of the warehouse 10, it may be necessary to provide a large entrance 11 in a low building. A structure that can meet this requirement is presented below.

[0092] [Warehouse change example] The warehouse 10 shown in Fig. 14 has the same height as the entrance 11 in Fig. 1, but the building is sufficiently low. For this reason, as shown in Fig. 14, the door 22 is configured as a multi-door consisting of a lower door 22A and an upper door 22B.

[0093] 15, a hook-shaped protrusion 78 is provided to extend inward at the upper edge of the upper door 22B resting on the stopper piece 77. When the lower door 22A suspended by the wire 23 and the chain 31 rises, the upper edge of the lower door 22A hits the protrusion 78. Thereafter, the lower door 22A pushes up the upper door 22B.

[0094] The lower door 22A is guided by an inner grooved rail 25, and the upper door 22B is guided by an outer grooved rail 26. Although they are shown separately for ease of drawing, a stopper piece 77 is fitted into the groove of the outer grooved rail 26 and fixed therein, and this stopper piece 77 defines the lower limit position of the upper door 22B.

[0095] The door drop mechanism of the present invention (FIG. 2(a), reference numeral 40) is attached to the inner grooved rail 25. That is, the part 2a in FIG. 14 may be the same as FIG. 2(a). Therefore, the present invention can be applied to both a warehouse 10 in which the entrance / exit 11 is blocked by one door and a warehouse 10 in which the entrance / exit 11 is blocked by two doors.

[0096] According to this modification, the height of the lower door 22A is about half the height of the doorway 11, and the height of the upper door 22B is also about half the height of the doorway 11, as shown in FIG. At the uppermost position shown by the imaginary line, the lower door 22A and the upper door 22B overlap each other in the front and rear. As a result, a large entrance 11 can be provided in a low building.

[0097] The number of doors 22 is not limited to two, but may be three or more multi-doors. By adopting multi-doors, the size of the entrance / exit 11 and the building height can be freely determined, which significantly increases the design freedom of the warehouse 10.

[0098] [How to fasten the wire] In Fig. 1, the wire 23 is connected to the lower side of the door 22. On the other hand, in Fig. 14, the wire 23 is connected to the upper side of the upper door 22B. If the width of the door 22 is 6 m or more, it is recommended to connect the wire 23 to the bottom edge of the door 22, and if the width of the door 22 is less than 6 m, it is recommended to connect the wire 23 to the top edge of the door 22.

[0099] The limit switch 45 may be a mechanical sensor or an electrical non-contact sensor that emits infrared rays or laser light to determine the presence or absence of an object. [Industrial Applicability]

[0100] The hanging door device of the present invention is suitable for agricultural warehouses. [Explanation of symbols]

[0101] 20...hanging door device, 21...channel rail, 21a...flange, 21b...web, 22...door, 23...wire, 24...free roller, 30...electric chain block, 40...door fall prevention mechanism, 41...safety bar, 42...hinge, 43...handle, 45...limit switch, 47...square steel pipe.

Claims

1. A suspended door device comprising a pair of left and right grooved rails that are U-shaped in plan view and arranged vertically, a door that is guided by these grooved rails so as to be able to move up and down, a wire that suspends the door, and an electric chain block that pulls up the wire, This hanging door device is characterized in that it further comprises a door fall prevention mechanism that is inserted under the door when the door is at its uppermost position to prevent the door from falling.

2. The hanging door device according to claim 1, A suspended door device characterized in that the door is provided with a rotatable free roller, and the door is guided along the grooved rail via the free roller.

3. The hanging door device according to claim 1 or 2, The door drop prevention mechanism is characterized by comprising a vertical safety bar that moves in and out of the groove of at least one of the pair of grooved rails, a hinge that rotatably engages the safety bar with the grooved rail, and a handle attached to the safety bar that is grasped by a worker standing on the floor.

4. The hanging door device according to claim 3, The safety bar is said to be in a set position when it is in the groove of the grooved rail, and is said to be in a standby position when it is out of the groove of the grooved rail, and the swing angle of the safety bar from the set position to the standby position is in the range of 260° to 280°.

5. The hanging door device according to claim 3, The suspension door device is characterized in that it further comprises a limit switch which permits operation of the electric chain hoist when the safety bar is in the standby position and prohibits operation of the electric chain hoist when the safety bar is in the set position, when the safety bar is in the groove of the grooved rail and when the safety bar is out of the groove of the grooved rail and the limit switch which prohibits operation of the electric chain hoist when the safety bar is in the set position.

6. The hanging door device according to claim 3, The suspension door device is characterized in that the safety bar is a square steel pipe of a size that fits into the groove of the channel rail.

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