JP2014091112A - Fume hood - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fume hood capable of preventing work failure of a falling prevention device and surely preventing falling of a front face door.SOLUTION: The falling prevention device 15 has a holder member 25 movable toward a vertical direction relative to a front face door 6. The holder member 25 is suspended to a suspension wire member 9 and an elastic member 36 for generating an energization force toward a vertical direction is provided on the holder member 25. The front face door 6 is supported on the elastic member 36 thereby the front face door 6 is suspended to the suspension wire member 9 through the holder member 25. And the holder member 25 has a claw member 28 for moving by being contacted by a part of the front face door 6 because of relative movement of the front face door 6 and the holder member 25 caused by the energization force of the elastic member 36 when the suspended state is released. And the falling prevention device 15 is disposed within a rail member, when the falling prevention device 15 works, the claw member 28 is contacted to an inner face 44 of the rail member.

Description

  The present invention relates to a fume hood used when performing a chemical experiment or the like.

  Conventionally, a draft chamber (fume hood) has a lifting door (front door) suspended by a suspension belt (suspended wire), and a balance weight is provided on the other end of the suspension belt via a pulley. This makes it possible for the user to easily open and close the elevator door. In an emergency such as when the suspension belt is cut, a device is provided to prevent the lifting door from dropping. In such a fall prevention device, a holder is arranged in the left and right vertical frames of the lifting door. The suspension belt is attached to the holder and a safety brake claw (claw member) is provided. When the suspension belt breaks, the holder is momentarily pushed downward by the compression spring, and the safety brake claw is pushed by the block. There is one that prevents the door from falling by rotating and biting into the guide groove of the front frame (rail member) (see, for example, Patent Document 1).

Japanese Patent No. 3553355 (page 4, FIG. 5)

  However, in the draft chamber (fume hood) described in Patent Document 1, the safety brake claw (claw member) is affected by the left and right movements of the elevating door (front door). When either one of the belts (suspended wire) is cut or the elevator door falls while swinging left and right, the distance between the safety brake pawl and the front frame (rail member) will be increased, and the safety brake pawl There is a possibility that the frictional force at the time of biting into the guide groove of the front frame may not function sufficiently, causing a malfunction of the fall prevention device.

  The present invention has been made paying attention to such a problem, and an object of the present invention is to provide a fume hood that can prevent malfunction of the fall prevention device and reliably prevent the front door from falling.

In order to solve the above problems, the fume hood of the present invention is:
A front door that is raised and lowered to open and close the front opening of the processing chamber is provided, and the left and right edges of the front door are disposed in rail members provided on the left and right of the opening, and the front door is suspended by a suspension wire. And a fume hood provided with a fall prevention device for preventing the front door from falling when the suspended state is released,
The fall prevention device has a holder member that is movable relative to the front door in the vertical direction. The holder member is suspended by the suspension wire, and the holder member is attached in the vertical direction. An elastic member for generating a force is provided, and the front door is supported on the elastic member, so that the front door is suspended by the suspension wire through the holder member, and the holder member has When the suspended state is released, the front door and the holder member are moved relative to each other by the biasing force of the elastic member, thereby providing a claw member that moves in contact with a part of the front door. The fall prevention device is disposed in the rail member, and the claw member is brought into contact with the inner surface of the rail member when the fall prevention device is operated.
According to this feature, when the front door, the suspension wire, and the suspended state are released, the front door and the holder member are moved relative to each other in the vertical direction by the biasing force of the elastic member, and contact a part of the front door. As a result, the claw member moves and protrudes at a predetermined angle, and the fall prevention device is disposed in the rail member, so that the fall prevention device is guided by the rail member regardless of the left-right movement of the front door. Therefore, the distance between the claw member of the fall prevention device and the inner surface of the rail member with which the claw member is contacted is maintained, and the malfunction of the fall prevention device is prevented and the front door is surely dropped. Can be prevented.

The fume hood of the present invention is
The fall prevention device is characterized by having a guide member that is held in a holding groove formed in the rail member in a vertically slidable state.
According to this feature, since the front door and the fall prevention device are guided by the rail member through the guide member, and the guide member is held in the holding groove formed in the rail member, the front door and the fall prevention device are wobbled. Can be prevented.

The fume hood of the present invention is
The rail member is provided with a stopper member that prevents the front door from being raised when the front door is raised to a predetermined height. The fall prevention device is provided with a stopper member provided on the stopper member. A contacted portion that is in contact with the contact portion is provided.
According to this feature, the front door is brought into contact with the stopper member via the fall prevention device, so that the impact force when the front door is brought into contact with the stopper member is buffered by the elastic member provided in the fall prevention device. Can be made.

It is a perspective view which shows the fume hood in an Example. It is a front view which shows a fume hood. It is an AA vertical side view in FIG. 2 which shows a fume hood. It is a disassembled perspective view which shows a fall prevention apparatus. It is a side view which shows a fall prevention apparatus. It is a BB cross-sectional view in FIG. 2 which shows a fall prevention apparatus and a rail member. It is a front view which shows the fall prevention apparatus at the time of non-operation. It is a front view which shows the fall prevention apparatus at the time of an action | operation. It is a side view which shows a stopper member. It is CC cross-sectional top view in FIG. 2 which shows a fall prevention apparatus and a stopper member. It is a perspective view which shows the operation part of the stopper member of the state seen from the front side of the housing | casing.

  EMBODIMENT OF THE INVENTION The form for implementing the fume hood which concerns on this invention is demonstrated below based on an Example.

  The fume hood according to the embodiment will be described with reference to FIGS. Hereinafter, the left side of FIG. 3, FIG. 5, and FIG. 9 will be described as the front side (front side) of the fume hood, and the lower side of FIG. 6 and FIG. 10 will be described as the front side (front side) of the fume hood. The code | symbol 1 of FIG. 1 is a fume hood used when performing a chemical experiment etc. The fume hood 1 has a processing chamber 3 inside a housing 2 (see FIG. 3), and an exhaust device 4 for exhausting air in the processing chamber 3 is provided on the top of the housing 2. .

  As shown in FIGS. 2 and 3, a fixed glass plate 5 made of tempered glass or the like is fixed above the opening on the front side of the housing 2. A front door 6 that is raised and lowered to open and close the opening of the housing 2 is provided below the fixed glass plate 5. Further, the front door 6 has an elevating glass plate 7 made of tempered glass or the like similarly to the fixed glass plate 5, and the lower edge of the elevating glass plate 7 has a gripping side gripped by the user. 8 is attached. The user can open and close the opening of the housing 2 by grasping the gripping side 8 and raising and lowering the front door 6.

  Further, the front door 6 is suspended in a state where the left and right lower ends thereof are connected to the suspension wires 9 and 9 formed of wires or the like. As shown in FIG. 1, a pair of left and right suspension wires 9, 9 that suspend the front door 6 are provided on one side (the left side in this embodiment) of the housing 2 via a plurality of pulleys 10. It is connected to a weight 11 made of a heavy metal plate or the like. By balancing the weight 11 and the front door 6 with the same weight, the user can raise and lower the front door 6 with a light force.

  As shown in FIG. 2, the upper position on the front side of the housing 2 is covered with an openable / closable decorative panel 12. Further, by opening the decorative panel 12, maintenance of the suspended wire rod 9, the pulley 10, the exhaust device 4, the control board (not shown) and the like at the upper position of the housing 2 can be performed. Further, the decorative panel 12 is provided with a plurality of lamps 13 indicating the operating state of the fume hood 1, and a lighting board (not shown) for controlling the lighting of the lamps 13 is provided on the back side of the decorative panel 12. ing.

  As shown in FIG. 3, the fixed glass plate 5 and the front door 6 are held by a pair of left and right rail members 14 provided on the left and right sides of the opening of the housing 2. The front door 6 is suspended from the suspension wire 9 via a fall prevention device 15 (see FIG. 6) disposed in the rail member 14. The fall prevention device 15 is provided at each of the left and right lower ends of the front door 6 and operates in an emergency such as when the suspension wire 9 is cut or the suspension wire 9 is detached from the weight 11. 6 is provided in order to prevent the fall of 6.

  In addition, the user inserts his / her hand into the processing chamber 3 in the state where the front door 6 is raised and opened to a predetermined opening (about one third). The experiment performed in the processing chamber 3 is performed while the exhaust device 4 is operated, and air is supplied into the processing chamber 3 from the opening below the front door 6, and Air is exhausted from the exhaust device 4. As described above, the air flowing in the processing chamber 3 always flows in one direction, and the gas generated in the processing chamber 3 does not flow backward toward the user. Furthermore, in this embodiment, the surface wind speed is secured at about 0.5 m / s.

  Further, when the front door 6 is opened beyond a certain opening amount, the air supply amount flowing from the opening below the front door 6 exceeds the exhaust amount of the exhaust device 4, and the air in the processing chamber 3 is directed toward the user side. There is a risk of backflow. In order to prevent this, a stopper member 16 that restricts the front door 6 from opening more than a certain opening amount is provided. The stopper member 16 is provided only on the left side of the left and right sides of the opening of the housing 2 (see FIG. 2). Further, when cleaning or maintenance in the processing chamber 3 is performed, if the stopper member 16 is operated, the restricted state of the front door 6 can be released, and the front door 6 can be fully opened.

  As shown in FIG. 3, two upper and lower baffle plates 19, which form an exhaust passage 18 for guiding the air in the processing chamber 3 to the exhaust device 4, are formed on the front side of the back plate 17 constituting the housing 2. 20 is attached. Of these baffle plates 19 and 20, the lower baffle plate 20 disposed on the lower side is attached via a cylindrical spacer member 21 provided on the front surface of the back plate 17. The upper baffle plate 19 disposed on the upper side is held by a holding frame 23 provided on the lower surface of the ceiling plate 22 constituting the housing 2, and the lower end edge of the upper baffle plate 19 of the lower baffle plate 20. It is held by a fixture 24 provided at the top.

  Next, the fall prevention device 15 for preventing the front door 6 from falling will be described in detail with reference to FIGS. In addition, since the fall prevention device 15 provided in each of the left and right lower ends of the front door 6 has the same configuration, the rail member 14 disposed on the left side will be described below as an example.

  As shown in FIG. 4, the fall prevention device 15 has a holder member 25 to which an end portion of the suspension wire 9 is attached. A guide member 27 composed of a guide roller held in a holding groove 26 (see FIG. 6) formed in the rail member 14 is attached to the back side of the holder member 25 as will be described later. The fall prevention device 15 has two guide members 27 arranged vertically, and the upper guide member 27 rotates about the center of a shaft portion 29 on which a claw member 28 described later is pivotally supported. The lower guide member 27 is attached to a lower position of a mounting piece 30 to be described later. The front side of the holder member 25 is covered with a holder cover 31.

  Further, between the holder member 25 and the holder cover 31, the end member 32 screwed to the end of the gripping side 8 (see FIG. 6) of the front door 6 and the front door 6 are actuated to prevent dropping. A claw member 28 is provided. The claw member 28 is pivotally supported by a shaft portion 29 protruding from the front side of the holder member 25. A curved surface 33 that contacts the stopper member 16 from above when the fall prevention device 15 is lowered is formed below the holder cover 31 (see FIG. 5).

  Further, on the upper part of the holder member 25, a contacted member 34 having a convex shape that comes into contact with the lower end of the stopper member 16 when the fall prevention device 15 is raised is provided. The abutted member 34 is attached via a mounting bracket 35. Further, the abutted member 34 protrudes upward and has a substantially circular shape in plan view (see FIG. 6). Further, the above-described suspended wire rod 9 and the abutted member 34 are juxtaposed in the left-right direction.

  As shown in FIGS. 4 and 5, a mounting piece 30 on which an elastic member 36 made of a coil spring is placed is formed on the lower portion of the holder member 25 so as to protrude forward, and this placing piece 30. The end member 32 (a part of the front door 6) is placed on the top via a coil spring. That is, the load on the front door 6 is applied to the holder member 25 from the end member 32 via the elastic member 36.

  Further, the holder member 25 is formed with a long hole 37 extending in the vertical direction, and the end member 32 is formed with a guide convex portion 38 slidably disposed in the long hole 37 of the holder member 25. Yes. Thus, the front door 6 to which the end member 32 is fixed is in a state in which it can move relative to the holder member 25 in the vertical direction.

  As shown in FIG. 6, the rail member 14 is a member that is formed by extrusion and extends in the vertical direction, and the rail member 14 has the same cross-sectional shape from the upper end portion to the lower end portion. A slide groove 39 that accommodates the fall prevention device 15 so as to be slidable in the vertical direction is formed inside the rail member 14.

  An opening 40 is formed on the side of the rail member 14 facing the front door 6, and the end member 32 of the front door 6 is introduced into the sliding groove 39 from the opening 40. And the front door 6 is hold | maintained at the sliding groove | channel 39 in the state which can be slid to an up-down direction via the fall prevention apparatus 15 to which the end member 32 of the right-and-left end part was attached.

  Moreover, the front-rear width of the opening 40 of the rail member 14 is narrower than the front-rear width of the fall prevention device 15, and the fall prevention device 15 is prevented from coming out of the opening 40 of the rail member 14. Further, a locking frame 41 extending in the vertical direction to which the claw member 28 of the fall prevention device 15 is locked is fixed to the inner surface on the opposite side of the opening 40 of the rail member 14. The locking frame 41 is disposed in a side portion arranging groove 42 formed in the rail member 14.

  The locking frame 41 is formed by bending a substantially plate-like member into a substantially U shape in plan view (see FIG. 6). Further, the locking frame 41 is formed with a locking surface 43 for locking the claw member 28 on the surface facing the fall prevention device 15, and a plurality of portions of the locking surface 43 are cut out. A plurality of locking portions 44 are juxtaposed in the vertical direction.

  In addition, a holding groove 26 that holds the guide member 27 of the fall prevention device 15 is formed in the rail member 14. The outer peripheral surface of the guide member 27 is a curved surface, and the inner surface of the holding groove 26 is an inner surface bent in a substantially square shape so as to be adapted to the outer peripheral surface of the guide member 27. Yes. By providing the holding groove 26 as described above, it is possible to prevent the fall prevention device 15 from wobbling in the left-right or front-rear direction while the guide members 27 arranged vertically can be slid in the up-down direction.

  Next, operation | movement of the fall prevention apparatus 15 is demonstrated based on FIG.7 and FIG.8. In FIG. 7 and FIG. 8, the rail member 14 is omitted to facilitate understanding.

  As shown in FIG. 7, the claw member 28 provided in the fall prevention device 15 has a locking claw 45 extending obliquely downward with the upper portion thereof being pivotally supported by the shaft portion 29. In addition, one side surface of the claw member 28 is bent in a substantially square shape when viewed from the front, and on this one side surface, a contacted surface 47 that is in contact with the contact surface 46 provided on the end member 32. Is formed.

  In a normal state, when the fall prevention device 15 is suspended from the suspension wire 9, the load of the front door 6 is applied to the elastic member 36 via the end member 32, and the elastic member 36 is compressed. It has become. In this state, the holder member 25 and the claw member 28 suspended by the suspension wire 9 are disposed at an upper position relative to the end member 32, and the claw member 28 faces downward. It has become. Therefore, the claw member 28 is separated from the locking frame 41, and the user can freely raise and lower the front door 6. Note that the relative position between the holder member 25 and the end member 32 does not change even when the user moves the front door 6 up and down during normal times.

  As shown in FIG. 8, both the fall prevention device 15 and the front door 6 are dropped in an emergency when the suspended state is released such as when the suspended wire rod 9 is cut. Since the holder member 25 is urged downward by the urging force, the holder member 25 is dropped slightly faster than the dropping speed of the end member 32 of the front door 6. Therefore, the holder member 25 and the claw member 28 are moved to a lower position relative to the end member 32, and the claw member 28 comes into contact with the end member 32, so that the locking claw 45 of the claw member 28 is removed. It is rotated so as to protrude to the side.

  Further, the rotation angle of the claw member 28 is adjusted in a state where the planar contact surface 47 provided on the claw member 28 and the planar contact surface 46 provided on the end member 32 are in close contact with each other. Since it is prescribed | regulated, the state which the nail | claw member 28 protruded by the predetermined angle without wobbling can be maintained.

  Then, the locking claw 45 of the claw member 28 is locked to the locking portion 44 of the locking frame 41, so that the fall prevention device 15 and the front door 6 are prevented from falling. By doing in this way, the front door 6 can be reliably prevented from falling because the locking claw 45 of the claw member 28 is locked to the locking portion 44 of the locking frame 41.

  It should be noted that the fall prevention device 15 and the front door 6 are prevented from falling by the frictional force generated when the locking claw 45 of the claw member 28 comes into contact with the locking surface 43 and the inner surface 48 of the locking frame 41. May be. In this way, regardless of the position of the front door 6 in the vertical direction, the frictional force between the locking claw 45 of the claw member 28 and the locking surface 43 and the inner surface 48 of the locking frame 41 can be used. The falling speed of the front door 6 can be immediately prevented.

  As described above, in the fall prevention device 15 in the present embodiment, when the front door 6, the suspension wire 9, and the suspended state are released, the front door 6 and the holder member 25 are moved by the urging force of the elastic member 36. The claw member 28 is moved relative to each other in the vertical direction, is brought into contact with the end member 32 of the front door 6 and is rotated by a predetermined angle, and the fall prevention device 15 is disposed in the rail member 14. Therefore, since the fall prevention device 15 is guided by the rail member 14 regardless of the left-right movement of the front door 6, the claw member 28 of the fall prevention device 15 and the rail member 14 with which the claw member 28 comes into contact are locked. The distance from the frame 41 is maintained, the malfunction of the fall prevention device 15 can be prevented, and the front door 6 can be reliably prevented from falling.

  In addition, the fall prevention device 15 includes a guide member 27 that is held in a holding groove 26 formed in the rail member 14 in a vertically slidable state, so that the front door 6 and the fall prevention device 15 are guided members. Since the guide member 27 is guided by the rail member 14 through 27 and is held in the holding groove 26 formed in the rail member 14, the front door 6 and the fall prevention device 15 can be prevented from wobbling.

  Next, the stopper member 16 for limiting the opening degree of the front door 6 will be described in detail with reference to FIGS.

  As shown in FIG. 9, the stopper member 16 is a member having a substantially L shape in a side view. The stopper member 16 is pivotally supported by a shaft portion 49 provided on the rail member 14 at the upper end thereof. The rail member 14 is provided with a shaft portion 49 and a front portion placement groove 50 for placing the stopper member 16 (see FIG. 10).

  Further, the stopper member 16 has a hanging portion 51 that is suspended from the shaft portion 49. A lower end of the drooping portion 51 is formed with a contact portion 52 that protrudes rearward and is contacted with the contacted member 34 of the fall prevention device 15 described above. In addition, an operating portion 53 that extends forward and is operated by an operator is formed at the lower end of the hanging portion 51. In addition, this operation part 53 protrudes toward the front, ie, protrudes in the same direction as the perpendicular direction of the surface of the front door 6. Further, the shaft portion 49, the contact portion 52, and the contacted member 34 are arranged side by side in a substantially vertical direction.

  The front side of the rail member 14 is covered with a front cover 54 that constitutes the front surface of the housing 2. The rail member 14 and the front cover 54 are provided with arrangement holes 55 and 56 in which the operation portion 53 of the stopper member 16 is projected. A protective member 57 that protects the periphery of the arrangement hole 56 is provided in the arrangement hole 56 of the front cover 54.

  Further, the operation portion 53 has a portion protruding from the arrangement holes 55 and 56 bent downward, and a knob 58 that is recessed in a curved shape is formed in the vicinity of the tip so as to be easily picked by the operator (see FIG. 11). In this embodiment, the rail member 14 and the front cover 54 constitute a cover member that covers the periphery of the contact portion 52 provided on the stopper member 16 and the contacted member 34 of the fall prevention device 15. .

  As shown in FIG. 9, a leaf spring member 59 as an urging means for urging the stopper member 16 rearward is provided between the hanging portion 51 of the stopper member 16 and the inner surface of the front placement groove 50. Yes. The upper end of the leaf spring member 59 is attached to the inner surface of the front arrangement groove 50, and the lower end is attached to the hanging portion 51 of the stopper member 16. The stopper member 16 is urged to rotate about the shaft portion 49 by the urging force of the leaf spring member 59, and the contact portion 52 of the stopper member 16 is arranged in the passage region of the fall prevention device 15. ing. When the fall prevention device 15 is located below the stopper member 16, the contact portion 52 of the stopper member 16 is disposed above the contacted member 34 of the fall prevention device 15 (see FIG. 10). .

  Then, when the user grasps the gripping side 8 of the front door 6 and raises the front door 6, the front door 6 is lifted, the fall prevention device 15 is also lifted, and the front door 6 is opened to a predetermined opening amount. Sometimes, the contact portion 52 of the stopper member 16 contacts the contacted member 34 of the fall prevention device 15 to prevent the front door 6 from rising.

  Further, when performing cleaning and maintenance in the processing chamber 3, if the operator holds the operation part 53 of the stopper member 16 and pulls it forward, the operator resists the urging force of the leaf spring member 59. The stopper member 16 is rotated forward about the shaft portion 49, the contact portion 52 of the stopper member 16 is detached from the contacted member 34 of the fall prevention device 15, and the fall prevention device 15 and the front door 6 are raised. become able to. When operating the operation unit 53, it is not necessary to pick the operation unit 53. For example, even if the tip of the operation unit 53 is moved upward, the biasing force of the leaf spring member 59 is not affected. Accordingly, the stopper member 16 is rotated forward about the shaft portion 49, and the contact portion 52 of the stopper member 16 comes off from the contacted member 34 of the fall prevention device 15.

  As shown in FIG. 11, the operation portion 53 of the stopper member 16 is provided on the inclined surface 60 close to the front door 6 in the front cover 54, and the operator holds the gripping side 8 of the front door 6. The opening operation of lifting up and the release operation of the stopper member 16 that moves the operation portion 53 upward can be performed in the same direction. Therefore, it is easy to release the stopper member while opening the front door 6. Become. For example, if the thumb is protruded to the side while gripping the gripping side 8 with a finger, the thumb can reach the operation portion 53 of the stopper member 16 and the release operation can be performed when the front door 6 is raised. .

  As shown in FIG. 9, when the fall prevention device 15 is located above the stopper member 16 and the front door 6 is lowered and the fall prevention device 15 is lowered, the holder cover 31 of the fall prevention device 15 is lowered. The lower curved surface 33 (see FIG. 5) contacts the back side of the drooping portion 51 of the stopper member 16, and the stopper member 16 pivots against the urging force of the leaf spring member 59 as the fall prevention device 15 descends. It is pivoted forward about the portion 49 to allow the fall prevention device 15 to descend.

  As described above, in the stopper member 16 in the present embodiment, the contact portion 52 provided in the stopper member 16 is in contact with the contacted member 34 provided in the fall prevention device 15 of the front door 6. The front door 6 is prevented from rising, and at least when the contact portion 52 and the contacted member 34 are contacted, a cover that covers the periphery of the contact portion 52 and the contacted member 34 By providing the rail member 14 and the front cover 54 as members, the rail member 14 and the front cover 54 provide a space between the contact portion 52 of the stopper member 16 and the contacted member 34 of the fall prevention device 15 of the front door 6. Therefore, the finger or the like can be prevented from being sandwiched between the contact portion 52 of the stopper member 16 and the contacted member 34 of the fall prevention device 15.

  The rail member 14 is a member extending in the vertical direction provided with a sliding groove 39 in which the fall prevention device 15 on the left and right edges of the front door 6 is slid, and an operation portion 53 for operating the stopper member 16 is provided. By projecting in the same direction as the normal direction of the surface of the front door 6 and moving the operation portion 53 upward, the contact state between the contact portion 52 and the contacted member 34 is released, The opening operation of the front door 6 that grasps the gripping side 8 of the front door 6 and lifts it along the sliding groove 39 of the rail member 14 and the release operation of the stopper member 16 that moves the operation portion 53 upward are in the same direction. Thus, the stopper member 16 can be easily released while the front door 6 is opened.

  Further, the stopper member 16 is pivotally supported by a shaft portion 49 provided on the rail member 14, and the contact portion 52 is provided at the lower end of the drooping portion 51 that hangs down from the shaft portion 49. When blocking, because the shaft portion 49, the contact portion 52 and the contacted member 34 are arranged in the vertical direction, the force applied to the stopper member 16 from the contacted member 34 of the front door 6 is as follows. Since it is transmitted to the shaft portion 49 in the vertical direction, the drooping portion 51 of the stopper member 16 is not bent or distorted, so that it is possible to prevent the stopper member 16 from being damaged due to many years of use. Furthermore, the rising of the fall prevention device 15 can be prevented without causing noise due to rattling or play of the stopper member 16.

  The rail member 14 is provided with a stopper member 16 that prevents the front door 6 from being raised when the front door 6 is raised to a predetermined height. The fall prevention device 15 is provided on the stopper member 16. By providing the abutted member 34 that abuts against the abutted portion 52, the front door 6 is abutted against the stopper member 16 via the fall prevention device 15, so that the fall prevention device 15 is provided. The elastic member 36 can buffer the impact force when the front door 6 is brought into contact with the stopper member.

DESCRIPTION OF SYMBOLS 1 Fume hood 3 Processing chamber 6 Front door 9 Hanging wire 14 Rail member 15 Fall prevention device 16 Stopper member 25 Holder member 26 Holding groove 27 Guide member 28 Claw member 32 End member 34 Contacted member 36 Elastic member 39 Sliding groove 40 Opening 44 Locking portion 45 Locking claw 46 Contact surface 47 Contacted surface 51 Suspended portion 52 Contact portion 53 Operation portion 54 Front cover

Claims (3)

A front door that is raised and lowered to open and close the front opening of the processing chamber is provided, and the left and right edges of the front door are disposed in rail members provided on the left and right of the opening, and the front door is suspended by a suspension wire. And a fume hood provided with a fall prevention device for preventing the front door from falling when the suspended state is released,
The fall prevention device has a holder member that is movable relative to the front door in the vertical direction. The holder member is suspended by the suspension wire, and the holder member is attached in the vertical direction. An elastic member for generating a force is provided, and the front door is supported on the elastic member, so that the front door is suspended by the suspension wire through the holder member, and the holder member has When the suspended state is released, the front door and the holder member are moved relative to each other by the biasing force of the elastic member, thereby providing a claw member that moves in contact with a part of the front door. A fume hood, wherein the fall prevention device is disposed in the rail member, and the claw member is brought into contact with an inner surface of the rail member when the fall prevention device is operated.   The fume hood according to claim 1, wherein the fall prevention device has a guide member that is held in a holding groove formed in the rail member so as to be slidable in the vertical direction.   The rail member is provided with a stopper member that prevents the front door from being raised when the front door is raised to a predetermined height. The fall prevention device is provided with a stopper member provided on the stopper member. The fume hood according to claim 1, further comprising a contacted portion that is in contact with the contact portion.

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