Door with emergency opening mechanism

Abstract

It provides an emergency opening mechanism that allows the door to be opened even if the lever handle falls off. [Solution] A door with an emergency release mechanism comprises a door body fitted with a door lock having a latch bolt. A through-hole is formed on the interior side of the door body, leading to the latch bolt. By applying an external force to the latch bolt through the through-hole, the latch bolt retracts inward towards the inside of the door body. A sleeve is fitted to the inner surface of the through-hole, and a cap is fitted to the interior opening.

Description

Technical Field

[0001] The present invention relates to a door to which a door lock having a latch bolt is attached, and particularly relates to a door with an emergency opening mechanism provided with a through hole leading to the latch bolt.

Background Art

[0002] Conventionally, latch bolt type door locks have been widely used for doors of buildings. A latch bolt type door lock includes a lever handle, a spindle, a cam mechanism, a latch bolt, and a coil spring. When a user operates the lever handle, the spindle rotates. The cam mechanism operates in accordance with the rotation of the spindle. By the operation of the cam mechanism, the latch bolt retracts into the latch case against the biasing force of the coil spring. When the latch bolt retracts, the engagement with the strike is released, and the door is opened. That is, in this door lock, a force transmission path from the lever handle to the latch bolt via the spindle and the cam mechanism is configured. The coil spring constantly biases the latch bolt to the protruding position. When the user does not operate the lever handle, the latch bolt engages with the strike, and the door is maintained in a closed state. With such a configuration, latch bolt type door locks are widely adopted in various buildings such as residential buildings, commercial facilities, and sauna facilities.

Prior Art Literature

Patent Literature

[0003]

Patent Literature 1

Summary of the Invention

Problem to be Solved by the Invention

[0004] However, in the conventional latch bolt type door lock described above, there is room for improvement in the door opening means when the lever handle falls off.

[0005] Specifically, if the mating surface between the lever handle and the spindle breaks, the lever handle will fall off. When the lever handle falls off, the means of rotating the spindle is lost. Because the spindle has a small cross-sectional area, it is difficult to rotate it directly by hand. Furthermore, the latch bolt is held in its protruding position by the biasing force of a coil spring, and will not retract unless an external force is applied. Therefore, a single failure, such as the detachment of the lever handle, makes it impossible to open the door. Such a structure inherently contains a single point of failure from a safety engineering perspective. In particular, if a user becomes trapped in a high-temperature environment such as a sauna, it could lead to a life-threatening situation.

[0006] This invention has been made in view of these problems, and the object of this invention is to provide a door with an emergency opening mechanism that allows the door to be opened by retracting the latch bolt even if the lever handle falls off. [Means for solving the problem]

[0007] To achieve the above objective, a door with an emergency opening mechanism according to one aspect of the present invention is a door to which a door lock having a latch bolt is attached, characterized in that a through hole is formed in the interior side surface of the door and leads to the latch bolt, and by applying an external force to the latch bolt through the through hole, the latch bolt is configured to retract toward the interior of the door. [Effects of the Invention]

[0008] According to the present invention, an alternative force transmission path independent of the one from the lever handle through the spindle and cam mechanism can be provided. This allows for emergency escape by retracting the latch bolt through the through hole, even if the lever handle falls off. [Modes for carrying out the invention]

[0009] Embodiments of the present invention will be described in detail below.

[0010] The outline of the door with an emergency opening mechanism according to this embodiment will now be described. The door with an emergency opening mechanism comprises a door body, a door lock, and a through hole. The door lock has a latch bolt. The through hole opens on the interior side of the door body and leads to the latch bolt. When a user applies external force to the latch bolt through the through hole, the latch bolt retracts toward the interior of the door body. This allows the user to open the door in an emergency, even if the lever handle falls off.

[0011] This section describes the overall configuration of a door with an emergency release mechanism. The emergency release mechanism comprises a door body and a door lock attached to the door body. The door body has an interior side. The door lock has lever handles on the interior side and on the opposite side of the door body. The door body is made of a material such as wood, metal, or resin. The door body is mounted to the door frame so as to be openable and closable. The door frame has a strike plate. The strike plate is a receiving fitting into which the latch bolt engages when the door is closed.

[0012] The configuration of the door lock is described below. The door lock comprises a latch bolt, a coil spring, a latch case, a cam mechanism, and a spindle. The latch bolt is housed within the latch case so as to be able to move back and forth. The coil spring biases the latch bolt in the protruding direction. The biasing force of the coil spring is 1 to 3 kgf. An inclined surface is formed at the tip of the latch bolt. The inclined surface has the function of automatically retracting the latch bolt by contacting the corner of the strike plate when the door is closed. The angle θ of the inclined surface is 40 to 50 degrees.

[0013] This section describes the normal door opening operation. When the user operates the lever handle, the spindle rotates. As the spindle rotates, the cam mechanism is activated. The cam mechanism retracts the latch bolt into the latch case against the biasing force of the coil spring. When the latch bolt retracts, it disengages from the strike plate. As a result, the door opens. In other words, the normal force transmission path is from the lever handle through the spindle and cam mechanism to the latch bolt.

[0014] This explains the problem of lever handle detachment in conventional technology. If the mating part between the lever handle and the spindle breaks, the lever handle will detach. The spindle has a cross-section of approximately 7 mm square, making it difficult to rotate by hand. Therefore, in conventional door locks, the door becomes impossible to open when the lever handle detaches.

[0015] The configuration of the through-hole is described below. The through-hole opens on the interior side of the door body. The through-hole penetrates the interior of the door body to the latch bolt. The diameter of the through-hole is 15 mm to 25 mm. This diameter is set to a size that allows a human finger to be inserted. The through-hole has an interior opening on the interior side. The through-hole constitutes an alternative path independent of the force transmission path from the lever handle through the spindle.

[0016] The relationship between the through-hole and the inclined surface of the latch bolt will be explained. In this embodiment, the through-hole is formed to reach the inclined surface of the latch bolt. When the user applies an external force in the direction toward the inclined surface through the through-hole, a wedge action occurs on the inclined surface. If the angle of the inclined surface is θ, the insertion force F is converted into a component force F × tan(θ) in the bolt retraction direction due to the wedge action of the inclined surface. When θ is 45 degrees, tan(45°) = 1.0, so a retraction force approximately equal to the insertion force can be obtained.

[0017] The wedge effect described above reduces the operating force required to retract the latch bolt. Specifically, when directly pushing the side of the latch bolt, a force is required to counteract the entire biasing force of the coil spring. On the other hand, when using an inclined surface, the required operating force is reduced due to the wedge effect. Furthermore, the linear motion of the user inserting their finger into the through-hole is directly converted into the retraction motion of the latch bolt. Therefore, the user does not need to be aware of the direction of the force.

[0018] The sleeve's construction is described below. A sleeve made of heat-resistant elastic material is installed on the inner surface of the through-hole. The sleeve is made of a heat-resistant elastic material such as silicone rubber or fluororubber. The sleeve has a heat resistance temperature of 200°C or higher. The sauna room is a high-temperature environment of 80°C to 110°C, and the metal latch bolt also reaches a similar temperature. The sleeve has an insulating function that prevents direct contact between the user's fingers and the metal surface of the latch bolt. This eliminates the risk of burns to the user.

[0019] The cap's structure is described below. A cap made of a heat-resistant elastic material is fitted to the indoor-side opening of the through-hole. The cap is made of a heat-resistant elastic material such as silicone rubber or fluororubber. The cap is configured to slide within the through-hole. The cap has a tip. The cap serves the following three functions.

[0020] The primary function of the cap is to provide a tight seal under normal circumstances. The cap closes the indoor-side opening of the through-hole. This prevents steam and heat from the sauna room from leaking through the through-hole. In other words, the cap compensates for the reduced airtightness caused by the presence of the through-hole.

[0021] The cap's second function is as an emergency operating element. When the user pushes the cap into the through-hole, the tip of the cap contacts the latch bolt. In this embodiment, the tip contacts the inclined surface of the latch bolt. The wedge action of the inclined surface causes the latch bolt to retract toward the inside of the door body. In other words, the cap itself functions as an operating element. The user can open the door with a single action of pushing the cap in.

[0022] The cap's third function is visibility in the dark. The indoor surface of the cap is coated with phosphorescent material. This phosphorescent material stores light energy under illumination. In the event of a power outage or in the dark, the phosphorescent material emits light that indicates the cap's location. This allows users to easily locate the cap even during a power outage or in a state of panic.

[0023] The operation during emergency opening will be described. When the lever handle has fallen off, a user visually recognizes the cap provided on the indoor side surface. The position of the cap can be confirmed even in a dark place by the light emitted from the phosphorescent material. When the user pushes the cap into the through hole, the cap slides within the through hole. The tip end of the cap abuts against the inclined surface of the latch bolt. Due to the wedge action of the inclined surface, the latch bolt retracts toward the inside of the door body against the biasing force of the coil spring.

[0024] When the latch bolt retracts, the engagement with the strike is released. Thereby, the door body is opened, and the user can escape in an emergency. The operation according to the present embodiment is only one action of pushing in the cap. It is not necessary to judge the direction, and it is also not necessary to adjust the magnitude of force. Even in a state where early to mid-term symptoms of heat exhaustion are progressing in a high-temperature environment, the user can perform the present operation. The heat insulating function of the sleeve also prevents the user from suffering burns during operation.

[0025] The effects of the door with an emergency opening mechanism according to the present embodiment will be described. First, the door with an emergency opening mechanism provides an alternative path independent of the force transmission path passing through the lever handle. This eliminates a single point of failure in terms of safety engineering. Second, the wedge action of the inclined surface can reduce the operating force required to retract the latch bolt. Third, the sleeve can eliminate the user's risk of burns in a high-temperature environment.

[0026] Fourth, the cap has both a sealing function and a function as an operating member. Thereby, an escape means in an emergency can be provided while maintaining the airtightness of a sauna room. That is, both airtightness and safety can be achieved. Fifth, the phosphorescent material allows the user to visually recognize the position of the cap even during a power outage or in a panic state.

[0027] Doors with an emergency release mechanism can be retrofitted to existing latch-bolt type doors. Installation involves drilling a through-hole in the door body and attaching a sleeve and cap. Replacing the door lock or the door body itself is unnecessary. Using a dedicated drill guide ensures the accuracy of the through-hole position. This allows for low-cost and short-term solutions to the safety renovation needs of existing facilities.

[0028] The present invention can be implemented with the following modifications.

[0029] As a first modification, the position of the through-hole can be changed. In the embodiment described above, the through-hole is formed to reach the inclined surface of the latch bolt. Alternatively, the through-hole may be formed to reach the side or rear end surface of the latch bolt. In this case, the user pushes the side or rear end surface of the latch bolt directly through the through-hole to retract the latch bolt.

[0030] As a second variation, the material of the sleeve can be changed. In the embodiments described above, the sleeve is made of silicone rubber or fluororubber. Alternatively, the sleeve may be made of a ceramic insulating material. When used in low-temperature environments, for example when applied to the door of a commercial freezer, insulating performance is not required, and the sleeve may be omitted.

[0031] As a third modification, a rod-shaped operating member may be inserted into the through-hole instead of the cap. In this case, the operating member is connected to the vicinity of the through-hole by a chain or the like. The user inserts the operating member into the through-hole to retract the latch bolt. The material of the operating member is preferably a heat-resistant resin material.

[0032] As a fourth variation, the application of the door with an emergency release mechanism can be changed. In the embodiment described above, the application to a sauna room door has been explained. Alternatively, it may be applied to a bedrock bath facility, a commercial freezer, a toilet or bathroom in a house, an airlock in a clean room, or a bulkhead door on a ship, etc. The material of the sleeve and cap should be appropriately selected according to each application.

[0033] As a fifth variation, a reflective material or a light-emitting diode may be provided on the cap instead of the phosphorescent material. If a light-emitting diode is used, a battery should be built into the cap. Alternatively, phosphorescent material may be added to the surface of the door body around the through-hole. This further improves visibility in dark places.

[0034] Although embodiments of the present invention have been described above, the present invention is not limited thereto, and modifications are possible without departing from the spirit of the invention. Furthermore, the above-described embodiments can be combined with each other.

Claims

1. In a door fitted with a door lock having a latch bolt, An opening is formed in the interior side of the door, and a through hole is formed that leads to the latch bolt. By applying an external force to the latch bolt through the through hole, the latch bolt is configured to retract toward the inside of the door. The latch bolt has an inclined surface at its tip, The through hole is formed to reach the inclined surface, A door with an emergency opening mechanism, characterized in that the latch bolt retracts due to the wedge action of the inclined surface when an external force is applied in the direction toward the inclined surface through the through hole.

2. In a door fitted with a door lock having a latch bolt, An opening is formed in the interior side of the door, and a through hole is formed that leads to the latch bolt. By applying an external force to the latch bolt through the through hole, the latch bolt is configured to retract toward the inside of the door. A door with an emergency opening mechanism, characterized in that a sleeve made of a heat-resistant elastic material is installed inside the through-hole.

3. In a door fitted with a door lock having a latch bolt, An opening is formed in the interior side of the door, and a through hole is formed that leads to the latch bolt. By applying an external force to the latch bolt through the through hole, the latch bolt is configured to retract toward the inside of the door. A cap made of heat-resistant elastic material is fitted to the indoor-side opening of the aforementioned through hole. The cap is slidable within the through hole, A door with an emergency opening mechanism, characterized in that pushing the cap into the through hole causes the tip of the cap to contact the latch bolt, thereby retracting the latch bolt.

4. The door with an emergency opening mechanism according to claim 3, characterized in that a phosphorescent material is attached to the indoor surface of the cap.