JPS6339848Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Technical Field] This invention relates to a lifting device for lifting and lowering lighting equipment and the like placed on a high ceiling. [Background Art] When installing lighting equipment on the high ceiling of a gymnasium or the like, an elevating device is required so that the lighting equipment can be raised and lowered as needed to replace or clean the lamps.
Such a lifting device needs to be provided with a locking means to prevent the lighting equipment from falling after the lighting equipment is raised to a predetermined height. Conventionally, an electromagnetic solenoid has been used as the locking means, but this requires a large number of parts and increases manufacturing cost. Another problem is that its operation is complicated and it is prone to failure. Furthermore, conventionally, a device has been proposed in which the locking device does not use a driving device as the locking device and is engaged and released only by operating the cable. However, when the lighting equipment is lowered from the rising end, the lighting equipment must be lowered after the lighting equipment has been operated by operating the cable so that the lighting equipment rises, which poses a problem in that the operation of the lighting equipment is complicated. [Purpose of the invention] The purpose of this invention is to solve the problems of the conventional method, to create a structure that prevents objects being lifted and lowered from falling, to be simple and less likely to break down, and to create a structure that requires extra operations during normal operation to prevent objects from falling. The purpose of the present invention is to provide a lifting device that is easy to use. [Disclosure of the invention] The elevating device of this invention comprises a mounting member for attaching an object to be lifted and lowered, a hook arm provided on the upper part of the mounting member, a lifting means for driving the mounting member up and down, the lifting means and the mounting member. It is provided with a cable connected between members, and a rotary locking hook supported at the upper end by the elevating means so as to be movable up and down. The rotation locking hook has an action portion that is pushed up by the upper surface of the hook arm, and a hook portion that enters below the hook arm as it is rotated by the push-up. In the natural hanging state of the rotary locking hook, the operating portion extends toward one side of the center of gravity of the rotary locking hook with a lower surface inclined downwardly, and the lifting path of the hooking arm is located in the middle thereof. The hook portion is located below the action portion and closer to the center of gravity than the lifting path of the hook member. Further, from a state in which the mounting member is located at the rising end and the acting portion of the rotational locking hook is placed on the hooking arm, the hooking arm engages with the hook portion of the rotational locking hook. The time required for the distal end portion of the hook portion to rotate to the elevation path is made slower than for the attachment member to naturally fall to the height. According to this invention, as the mounting member rises, the upper surface of the hook arm pushes up the action part and rotates the rotating locking hook, and with this rotation, the hook portion enters the lower part of the hook arm, Since the hook arm engages with the hook part when the attachment member falls, it is possible to prevent the object to be lifted and lowered from falling when the cable is cut, without interfering with the vertical movement of the object to be lifted and lowered. The structure in which the rotating locking hook is engaged takes advantage of the fact that the descending speed of the object to be lifted and lowered is different when it falls naturally due to cable cutting, etc. and when it is being driven downward. The rotation follows the descent of the object to be lifted and lowered, and the hook member does not engage with the hook. Since the rotation of the rotational locking hook cannot follow the fall, the hook member engages with the hook. Embodiment FIG. 1 is a perspective view showing the configuration of the present invention.
An object 1 to be lifted and lowered, such as a lighting fixture, is fixed to a mounting member 2. Inside the mounting member 2, a pair of pulleys are arranged, and a cable 3 having one end fixed therein is guided. The other end of the cable 3 is wound around a winding drum 5 via a pulley 4. The winding drum 5 is rotationally driven by a forward/reverse rotation motor 6, and the cable 3 is wound/unwound, whereby the object 1 to be lifted and lowered is moved up and down. This embodiment is provided with a rotating locking hook 7 and a hook arm 8 in order to prevent the object 1 to be lifted and lowered from falling when the cable 3 is cut for some reason.
The U-shaped hooking arm 8 has legs 8a and 8b fixed to the upper part of the mounting member 2. A rotary locking hook 7 having a hook portion 7a and an action portion 7b is rotatably fixed to a support shaft 9 disposed at a fixed position. By engaging the hook portion 7a of the locking hook 7 and the body portion 8c of the hook arm 8, the object 1 to be lifted and lowered is prevented from falling. FIG. 2 is a diagram showing the relationship between the rotating locking hook 7 and the hooking arm 8 in a normal state in which the cable 3 is not cut.
In the natural state, as shown in FIG. 2, the locking hook 7 is formed in such a shape that its operating portion 7b extends toward one side of the center of gravity G with its lower surface tilted downward, and the hook arm 8 is raised and lowered along the way. The route is located. The hook portion 7a of the locking hook 7 is located below the action portion 7b, and is closer to the center of gravity position G than the lifting path C of the hook arm 8 (coinciding with the center line passing through the center of gravity of the mounting member 2). .
As shown in FIG. 2, when the mounting member 2 rises and comes near the highest point, the hooking arm 8 comes into contact with the action portion 7b of the rotation locking hook 7. When the mounting member 2 further rises as shown in FIGS. 2 3 to 2 5, the hook arm 8 pushes up the action part 7b, and the rotation locking hook 7 is angularly displaced in the direction of the arrow A. The hook portion 7a enters below the hook arm 8. Figure 2 6
When the mounting member 2 reaches its highest point as shown in FIG. When the attachment member 2 is lowered, the rotation locking hook 7 is angularly displaced from the state shown in FIG. 2, and returns to its original natural state as shown in FIG. 2, FIG. FIG. 3 is a diagram showing the relationship between the rotation locking hook 7 and the hook arm 8 when the cable 3 is cut at the highest point of the mounting member 2. At the highest point of the mounting member 2 shown in FIG. 3, the hook portion 7a of the rotating locking hook 7 is located below the body portion 8c of the hooking arm 8, and FIGS. 32 to 36 are This shows a state in which the cable 3 is cut and the attachment member 2 falls naturally. When the mounting member 2 falls naturally, the rotation locking hook 7 is angularly displaced.
The hook portion 7a is engaged with the body portion 8c of the hook arm 8 before it is removed from the center line c of the attachment member 2. The displacement angle θ of the rotating locking hook 7 at this time is given by the following first equation. However, A: Displacement angle of the highest point g: Gravitational acceleration L: Distance from the center of rotation to the center of gravity G t: Elapsed time Also, the natural fall position h of the mounting member 2 at this time
is determined by the following second equation. h = 1/2g・t ² ...(2) For example, if A = 50° and L = 2.76cm, the displacement angle θ of the locking hook 7 and the natural fall position h of the mounting member 2 at the elapsed time t are as follows. It will look like Table 1.

[Effect of idea]

The lifting device of this invention takes advantage of the fact that the lowering speed of the object to be lifted and lowered differs when it falls naturally due to cable breakage, etc. and when it is being driven downward. The hook member does not engage with the hook part following the descent of the elevating object. Since the rotation of the rotational locking hook cannot follow the fall, the hook member engages with the hook. Therefore, it is possible to prevent the object to be lifted and lowered from falling by a simple action that does not interfere with the vertical movement of the object to be lifted and lowered. In addition, since the speed difference is utilized as described above, there is no need for the operation of raising the object to be lifted and lowered a little at the beginning of the descent as in the conventional example in normal lifting operations, and an extra operation is required to prevent the object from falling. does not require. Therefore,
It is easy to operate, and even when controlled automatically, the control operation is simple.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the configuration of an embodiment of this invention, FIG. 2 is a view showing the relationship between the rotary locking hook 7 and the hook arm 8 in normal conditions, and FIG. 3 is a view when the cable 3 is cut. Figure 4 showing the relationship between the rotation locking hook 7 and the hook arm 8.
The figure is a front sectional view of a specific embodiment of this invention, and FIG. 5 is a side sectional view of FIG. 4. 2, 10... Mounting member, 3, 13... Cable,
5, 16... Winding drum, 6, 17... Motor, 7, 18... Rotating locking hook, 7a, 18a...
Hook portion, 7b, 18b... acting portion, 8, 19... hooking arm.

Claims (1)

[Scope of utility model registration request] a mounting member for attaching an object to be lifted and lowered; a hook arm provided on the upper part of the mounting member; a lifting means for driving the mounting member up and down; a cable connected between the lifting means and the mounting member; A rotary locking hook is supported by the lifting means so as to be able to move up and down, and the rotary locking hook has an action portion that is pushed up by the upper surface of the hook arm and, as the hook is rotated by this pushing up, the hook It has a hook portion that enters below the arm, and when the rotation locking hook is in a naturally suspended state, the acting portion extends to one side of the center of gravity of the rotation locking hook with a lower surface inclined downwardly. The lifting path of the hooking arm is located in the middle, and the hook portion is located below the action portion and closer to the center of gravity than the lifting path of the hooking member,
From a state in which the mounting member is located at the rising end and the operating portion of the rotational locking hook is placed on the hooking arm, the height at which the hooking arm engages with the hook portion of the rotational locking hook is increased. The elevating device is configured such that the time it takes for the tip of the hook to rotate to the elevating path is slower than for the mounting member to naturally fall.