JP2008285907A - Fall preventing mechanism for draft chamber lifting door - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a door from falling due to cutting of a wire in the draft chamber door composed of the wire for hanging the door, and a weight provided at the tip of the wire, and freely openable/closable by the balance of the weight and door. <P>SOLUTION: A lifting door fall preventing mechanism provided with a stopper at a connection part between the door and the wire to turn in one direction by a spring is constituted not to turn the stopper against the force of the spring, that is, not to operate the stopper, by the force in a direction to support the door with the wire in a normal time and to operate by turning of the stopper by the spring immediately when the wire is cut, to suppress and prevent the fall of the door to thereby ensure safety. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

    The present invention relates to a draft chamber, and more particularly, to a mechanism for preventing a door from dropping in a draft chamber.

    As is well known, the draft chamber generates dangerous substances such as gas and particles during experiments using chemicals, etc., and in order to eliminate the adverse effects on workers (experimenters) etc. due to this, A device that encloses and exhausts substances.

    As shown in FIG. 3, the draft chamber main body 1 has a work chamber 2 and a storage chamber 3, and the work chamber 2 is provided with a work table 4. Work such as chemical experiments is performed.

    A lift door 9 is provided at the front opening of the work chamber 2 to open and close the opening. On the other hand, a rear partition plate that forms an exhaust passage 4 is formed on the rear surface of the work chamber 2, an exhaust port 5 is formed in the upper part of the main body, and gas in the work chamber is discharged from the exhaust port 5 through the exhaust passage 4. To be. As a result, dangerous substances such as gas generated in the operation as described above are discharged and the air is replaced.

    The draft chamber described above is provided with the lift door 9 in order to maintain the internal air flow in a predetermined state when the operator conducts the experiment, and the air flow in the working chamber is kept good. So that it is closed. In addition, when the worker works, the door needs to be opened. For this purpose, the position of the door and the position between the door and the space is set so that the worker can perform the work and the air flow in the draft chamber is maintained as much as possible. It is preferable to do so.

    Moreover, depending on the work content, there are cases where the door needs to be opened relatively and those that can be operated without much opening, and the degree to which the door needs to be opened differs.

    Therefore, the elevator door is easy to open and close, can maintain the required work space, and is stopped at a desired position in order to maintain the state of the working chamber of the draft chamber (air flow, etc.) Need to last.

    Therefore, the door opening / closing mechanism in the draft chamber has a configuration using the principle as shown in FIG.

    For example, as shown in FIG. 4, the door 10 is held by hanging with two left and right wires 11, 12, and the other ends of the wires 11, 12 are provided with hooks 15, 16 via pulleys 13, 14, respectively. The force to be pulled up by the scissors is made equal to the gravity applied to the door 10 and balanced. And by using such a mechanism, the raising / lowering door 10 can be stopped in an appropriate position. Further, when the operator pushes up or down the lift door, it can move with a very light force. In addition, when the force to push up or push down is stopped, it stops at that position and keeps this stopped state.

    FIG. 5 shows another example of a door opening / closing mechanism based on the same principle, in which two wires 11 and 12 are combined into one via pulleys 17 and 18 and a common rod 19 is connected to the end. The principle is basically the same as in FIG. 5, and the force that is pulled up by the bag is balanced with the gravity of the door.

    In such a lift chamber opening / closing mechanism of the draft chamber, the door falls when the wires 11 and 12 are cut. In particular, if the door falls during work, it is dangerous for the worker.

    In order to avoid such a danger, conventionally, a stopper is provided on the elevator door, and when performing an operation, the operator sets the stopper before performing the operation. In addition, the lift door was closed after the stopper was released after the work was completed.

    As described above, the operator has to manually set and release the stopper, which is inconvenient.

    The present invention provides a mechanism for preventing the fall of a lift door in a draft chamber in which a stopper acts immediately to prevent the door from falling when a wire supporting the lift door of the draft chamber is cut.

    The draft chamber equipped with the door fall prevention mechanism of the present invention is such that the door can be opened and closed by a balance by a fence, and can be stopped at an appropriate position. The wire is cut at the tip of the wire that hangs the door. It is provided with a stopper that operates when

    The door fall prevention mechanism provided in the draft chamber of the present invention is attached to a connecting portion for suspending a wire door, and does not operate when a wire load is applied to the wire. It was made to work at times.

    As a result, when the load is no longer applied due to the cutting of the wire, an action as a stopper works, thereby preventing the door from falling.

    The door fall prevention mechanism used in the draft chamber of the present invention is configured to have a stopper and this stopper is operated by the force of a spring, so that it is not always operated by the force of the load of the kite. It is supported and operates by the disappearance of the load of the heel by cutting the wire.

    Therefore, when the force applied to the wire due to the cutting of the wire disappears, the stopper is actuated by the spring to immediately prevent the door from falling.

    The present invention is a lifting door that can be moved up and down by being suspended by a wire, balanced by a weight, and stopped at an arbitrary position. Even if the wire is cut at any position, immediately when the door falls due to this cutting. By operating and preventing falling, the danger of work can be completely eliminated.

    DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described based on illustrated examples.

    FIG. 1 shows a fall prevention mechanism for a lift door of a draft chamber according to the present invention. In FIG. 1, reference numeral 20 denotes a door holding frame (window frame) that is provided on the side surface of the front opening (window) of the draft chamber so as to be movable up and down. A drop prevention mechanism 30 is provided on the holding frame portion. Is provided. The fall prevention mechanism 30 includes a stopper 33 having a claw 34 and is rotatably supported by a shaft 31 attached to the frame of the elevating door. The stopper 33 is configured to be rotated clockwise by a spring 32. Has been. In addition, a wire attachment hole 35 is formed at one end of the stopper 33, and a tip of a wire for hanging the lifting door is hung on the hole 35.

    Therefore, the elevating door is supported by the wire through the stopper 33 so as to be elevable.

    When the force in the direction indicated by the arrow in FIG. 1A is acting, the fall prevention mechanism of this embodiment does not operate, that is, the spring is applied by the upward force applied to the mounting hole 35. The rotational force around the shaft 31 of the 32 is blocked and the state of FIG.

    On the other hand, when the force applied to the hole 35 does not work, the stopper 33 rotates by the force of the spring 32, and the fall prevention mechanism shown in FIG.

    The operation of the fall prevention mechanism of the present invention will be described with reference to FIG.

    As shown in FIG. 2, the wire 40 is attached to the wire attachment hole 35 of the stopper, whereby the elevating door is supported by the wire 40 via the fall prevention mechanism 30. 2A shows a normal state in which the wire 40 is not cut, and FIG. 2B shows a state in which the fall prevention mechanism in which the wire is cut is activated.

    As shown in FIG. 2A, when the elevator door is supported by the wire 40, the stopper 33 is connected to the wire 40 by the load applied to the wire (by the force pulling the wire 40 by the hook). Has been raised. That is, a force in the direction of the arrow in FIG. 2 is applied. Thereby, as shown in FIG. 2A, the elevating door is moved up and down by an up and down operation by an experimenter or the like, or is held stationary at a predetermined position.

    On the other hand, when the wire 40 is cut, no load is applied, that is, there is no force to pull up the stopper 33 in the arrow direction by the wire 40, and the stopper 33 rotates clockwise by the action of the spring 32. Thereby, the claw 34 of the stopper 33 enters the receiving hole of the fall prevention plate (fall prevention frame 21) formed in the holding frame 20 of the window and prevents the door from dropping.

    As described above, the elevating door provided with the door fall prevention mechanism of the embodiment can prevent the door from dropping even when the wire is cut, and can safely proceed with the work in the working chamber of the draft chamber.

    In the illustrated drop prevention mechanism, a plurality of receiving holes for receiving the claw 34 at the tip of the stopper 33 are provided in the window frame portion (drop prevention frame 21).

    Therefore, when the fall prevention mechanism is actuated, that is, when the stopper 33 is rotated by the spring 32, when the claw 34 of the stopper 33 is not in the position where it is inserted into the receiving hole of the fall prevention frame 21, the door has dropped a short distance. Later, the claw 34 of the stopper 33 is inserted into the receiving hole 21, and the door falls safely. The distance at that time is relatively small and does not pose any danger to the operator. In addition, the claw 34 of the stopper 33 has a certain thickness, and is prevented from dropping due to friction caused by pressure bonding to the surface of the holding frame of the window. .

    In the first embodiment, the fall prevention frame provided on the holding frame for holding the elevating door is provided with a plurality of receiving holes, and the fall prevention mechanism of the present invention operates, that is, the stopper 33 rotates. The claw 34 is inserted into the receiving hole 21 to prevent the fall, but the present invention is not limited to this, and any structure that prevents the fall by the claw 34 of the stopper 33 in the operating state may be used.

    In addition, as the fall prevention mechanism of the present invention, among the above-described configurations, the safety of the fall prevention frame can be suppressed by simply pressing the claw of the stopper to the fall prevention frame without providing a receiving hole in the fall prevention frame. It is also possible to ensure.

    In this case, it is possible to improve the suppression effect by adopting a configuration in which the friction of the portion to which the stopper claw and the fall prevention frame are pressed is increased.

    In addition, increasing the force of the spring to increase the pressure on the stopper pawl is also effective in increasing the force that suppresses the falling of the elevator door, ensuring the prevention effect, especially sufficient safety. Can do.

    Attached to a lift door that opens and closes a draft chamber used for chemical experiments, etc., and prevents sudden drops due to wire cutting, which immediately stops the door from dropping if the wire is cut during work. As a result, the danger to the operator can be prevented.

The figure which shows the structure of the fall prevention mechanism of this invention The figure explaining the fall prevention effect | action of the raising / lowering door by the fall prevention mechanism of this invention Diagram showing the configuration of the draft chamber The figure which shows an example of the principle of the door opening / closing mechanism of the raising / lowering door of a draft chamber Another example of the principle of the door opening / closing mechanism of the lift door of the draft chamber is shown

Explanation of symbols

20 Door holding frame 21 Fall prevention frame 30 Fall prevention mechanism 31 Shaft 32 Spring 33 Stopper 34 Claw 35 Wire attachment hole 40 Wire

Claims (4)

It is a door opening and closing mechanism provided on the front of the draft chamber, which can be opened and closed easily by a balance with the fence provided at the other end by a wire hanging the door, and can be stopped at a free position, An elevator door fall prevention mechanism that is activated only when the door is dropped by cutting the wire provided at the connection between the door and the wire. The door fall prevention mechanism includes a stopper that is supported so as to be rotatable with respect to an axis provided on the lifting door, and a spring for moving the stopper to an operating position, and by attaching the wire to the stopper The elevator door is held by a wire through a stopper, and the stopper keeps the non-operating position against the force of the spring by the action of a force in the direction of supporting the door by the wire. The vertical movement of the elevator door can be freely performed, and the stopper is moved to the operating position by the action of the spring by cutting the wire to prevent the elevator door from falling. The fall prevention mechanism of the elevator door. The mechanism according to claim 2, wherein a claw at the tip of the stopper is pressed against a wall surface of a window frame that guides the elevator door so that the elevator door can be moved up and down. The window frame is provided with a fall prevention frame having an opening, and when the stopper is in the operating position, a claw of the stopper is inserted into the opening, thereby completely stopping the lowering of the lifting door. No. 3 lift door fall prevention mechanism.

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