Device for sensing fall based on speed for overhead door and fall prevention apparatus using the same

Abstract

A speed-sensitive fall detector for an overhead door and a fall prevention device using the same are provided. A speed-sensitive fall detector for an overhead door according to an embodiment of the present invention comprises: a housing having a disc shape with a first through hole formed in the center, a side wall having a certain height and thickness along the outer circumference, an acceleration section having a radius that gradually increases outward from a point (S) on the side wall, a stopping step having a stop at the end opposite to the point on the acceleration section, wherein the point is positioned at the uppermost side of the side wall and the stopping step has an angle (θ) formed with the point on the side wall with respect to the center of 35 to 55°; and a coupling part having a circular ring shape having a second through hole formed in communication with the first through hole of the housing and coupled to the first through hole. A plurality of pins, one end of which is rotatably coupled at a plurality of positions arranged at an equal angle along the outer circumference of the first through hole between the receiving portion and the coupling portion of the housing, and the other end of which slides along the side wall, wherein at a speed below a certain speed, the inward folding does not enter the acceleration section, and when the speed exceeds a certain speed, the inward folding is delayed by centrifugal force to enter the acceleration section and is seated by the stopping step to rotate the housing; and a shaft connected to a sensing roller, one end of which is inserted into the first through hole and the second through hole and coupled to the housing, and the other end of which is provided to contact one side of the guide rail.

Description

Technology Field

[0001] The present invention relates to a speed-sensitive fall detector for an overhead door and a fall prevention device using the same. In particular, the invention relates to a speed-sensitive fall detector for an overhead door and a fall prevention device using the same, which can rapidly detect abnormal descent of the door and stably prevent falling by changing the operating state by centrifugal force according to a change in the rotational speed of the door to cause mechanical jamming. Background Technology

[0002] Generally, an overhead door is a door consisting of multiple connected panels that moves vertically to open and close. These doors are raised and lowered by drive mechanisms such as chains, rollers, and springs, and are primarily used in large entrances for logistics warehouses, factories, fire station garages, and the like.

[0003] Due to the structural heavy weight of these overhead doors and their vertical movement from a certain height, there is a high risk of casualties or equipment damage if a malfunction occurs during operation and the door falls. In particular, as the weight of the door can reach several hundred kilograms, the impact upon falling is severe and highly likely to lead directly to safety accidents.

[0004] Accordingly, safety devices to prevent falling are essential for overhead doors. Conventional fall prevention devices are generally configured to activate when specific abnormal situations occur, such as chain breakage, and utilize a method that prevents the door from falling through a mechanical locking structure in the event that the chain or connecting part breaks.

[0005] However, conventional fall prevention devices have a limitation in that they do not operate when the door descends abnormally rapidly while the chain remains intact. In other words, even when the drive system is properly connected, a problem arises where the fall prevention device fails to detect the door if it falls rapidly due to control malfunctions or external forces.

[0006] In addition, in the case of fall prevention methods using electrical sensors or control devices, operation is impossible if the power supply is cut off.

[0007] Therefore, there is a need for a solution that operates regardless of power supply and can function quickly and stably even in abnormal drop situations. Prior art literature

[0008] (Patent Document 0001) KR 10-2586693 B1 The problem to be solved

[0009] To solve the problems of the conventional technology described above, one embodiment of the present invention aims to provide a speed-sensitive fall detector for an overhead door and a fall prevention device using the same, which can rapidly detect abnormal descent of the door and stably prevent falling by changing the operating state by centrifugal force according to a change in the rotational speed of the door to cause mechanical jamming.

[0010] The problems of the present invention are not limited to those mentioned above, and other unmentioned problems will be clearly understood by a person skilled in the art to which the present invention pertains from the description below. means of solving the problem

[0011] According to one aspect of the present invention for solving the above problem, a housing is formed in the shape of a disc having a first through hole formed in the center, and a side wall is provided along the outer circumference with a certain height and thickness, and an acceleration section is provided in which the radius gradually increases outward from a point (S) on the side wall, and a stopping step is provided at the end opposite to the point on the acceleration section, wherein the point is positioned at the uppermost side of the side wall and the stopping step has an angle (θ) formed with the point on the side wall with respect to the center of 35 to 55°; and a coupling part is formed in the shape of a circular ring having a second through hole communicating with the first through hole of the housing and is coupled to the first through hole. A speed-sensitive drop detector for an overhead door is provided, comprising: a plurality of pins, one end of which is rotatably coupled at a plurality of positions arranged at an equal angle along the outer circumference of the first through hole between the receiving portion and the coupling portion of the housing, and the other end of which slides along the side wall, wherein at a speed below a certain speed, the inward folding does not enter the acceleration section, and when the speed exceeds a certain speed, the inward folding is delayed by centrifugal force to enter the acceleration section and is seated by the stopping step to rotate the housing; and a shaft, one end of which is inserted into the first through hole and the second through hole and coupled to the housing, and the other end of which is connected to a sensing roller provided to contact one side of a guide rail.

[0012] In one embodiment, the pin is provided with a coupling member on one side that is coupled to the housing, and the outer periphery of the first side is formed as a curve with a constant curvature (R), and the inner side of the second side opposite the first side is formed to protrude outward from the coupling member to a protrusion, and is formed to be concave inward from the protrusion to a concave part, and can be formed as a straight line or a curve from the concave part to the other side.

[0013] In one embodiment, with respect to the center line from the center of the coupling member to the other side, the area (A1) of the outer periphery side is larger than the area (A2) of the inner side side, and the inner side between the coupling member and the concave part is positioned between the coupling part and the housing, and the outer periphery and the inner side from the concave part to the other side may be positioned between the coupling part and the side wall.

[0014] In one embodiment, the width (H) of the stop step corresponds to the width of the other side of the pin, and with respect to the distance (L) from the center of the coupling member to the other side, the center of gravity of the pin is located at 0.35L to 0.7L from the center of the coupling member, the curvature of the outer periphery of the pin is 0.66L to 0.8L, the first width (W1) at the protrusion of the pin is 0.44L to 0.55L, the second width (W2) at the concave part of the pin is 0.35L to 0.42L, W2:W1 is 0.64 to 0.95:1, and the area (A1) of the outer periphery side may be 1.1 to 1.6 times larger than the area (A2) of the inner side side.

[0015] According to another aspect of the present invention, an overhead door fall prevention device is provided, comprising: a speed-sensitive fall detector as described above; a link coupled to the outer surface of the housing of the speed-sensitive fall detector; and a braking device that is triggered by the rotation of the link and comes into contact with a guide rail to stop a falling door by frictional force. Effects of the invention

[0016] A speed-sensitive fall detector for an overhead door and a fall prevention device using the same, according to one embodiment of the present invention, can rapidly detect abnormal descent of the door and stably prevent falling by changing the operating state by centrifugal force according to a change in the rotational speed of the door to generate a mechanical catch, thereby minimizing human casualties and equipment damage caused by falling doors.

[0017] In addition, the speed-sensitive fall detector for an overhead door and the fall prevention device using the same, according to one embodiment of the present invention, operate mechanically without electrical control, thereby reliably preventing falls even in situations where the power is cut off, and thus improving the reliability of the system.

[0018] In addition, the speed-sensitive fall detector for an overhead door and the fall prevention device using the same according to one embodiment of the present invention operate selectively only under critical conditions based on rotational speed, and by maintaining a folded state at low speeds due to the shape and asymmetrical structure of the pin and unfolding only at high speeds to cause jamming, unnecessary operation during normal operation can be suppressed, thereby reducing component wear and inspection frequency caused by malfunctions and reducing maintenance costs.

[0019] In addition, the speed-sensitive fall detector for an overhead door and the fall prevention device using the same according to one embodiment of the present invention can precisely set the responsiveness and operational sensitivity to centrifugal force by adjusting the center of gravity position, curvature, shape, and mass distribution of the pin, thereby enabling rapid detection even at short fall distances and responding to various door loads and fall conditions.

[0020] In addition, the speed-sensitive fall detector for an overhead door and the fall prevention device using the same according to one embodiment of the present invention can improve the operating threshold speed and jamming stability by defining the acceleration section, the angle (θ) and width (H) of the stop step, and the corresponding structure of the pin, thereby ensuring reliable operation even in a repetitive operation environment.

[0021] In addition, the speed-sensitive fall detector for an overhead door and the fall prevention device using the same according to one embodiment of the present invention are composed of a simple mechanical structure, which facilitates manufacturing and ensures cost competitiveness, thereby improving applicability in industrial settings.

[0022] The effects of the present invention are not limited to the effects described above, and should be understood to include all effects that can be inferred from the configuration of the invention described in the detailed description or claims of the present invention. Brief explanation of the drawing

[0023] FIG. 1 is a perspective view of an overhead door according to one embodiment of the present invention. FIG. 2 is a perspective view of a speed-sensitive fall detector for an overhead door according to one embodiment of the present invention. FIG. 3 is a plan view (a) and an enlarged view (b) of a pin of a speed-sensitive drop detector for an overhead door according to one embodiment of the present invention. FIG. 4 is an operation state diagram of a speed-sensitive drop detector for an overhead door according to an embodiment of the present invention. FIG. 5 is an operation state diagram of a speed-sensitive drop detector for an overhead door according to one embodiment of the present invention. FIG. 6 is an installation diagram of a speed-sensitive fall detector for an overhead door according to an embodiment of the present invention. FIG. 7 is a diagram showing the state of operation for preventing falls by a speed-sensitive fall detector for an overhead door according to one embodiment of the present invention. Specific details for implementing the invention

[0024] Hereinafter, embodiments of the present invention are described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. The present invention may be embodied in various different forms and is not limited to the embodiments described herein. In the drawings, parts unrelated to the explanation have been omitted to clearly explain the present invention, and the same reference numerals have been used for identical or similar components throughout the specification.

[0025] The words and terms used in this specification and claims are not limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the invention in accordance with the principles by which the inventor defines terms and concepts to best describe his invention.

[0026] Therefore, the embodiments described in this specification and the configurations illustrated in the drawings correspond to preferred embodiments of the present invention and do not represent all technical concepts of the present invention; thus, various equivalents and modifications that may replace such configurations may exist at the time of filing the present invention.

[0027] In this specification, terms such as “comprising” or “having” are intended to describe the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should not be understood as precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0028] Hereinafter, a speed-sensitive fall detector for an overhead door according to an embodiment of the present invention will be described in more detail with reference to the drawings. FIG. 1 is a perspective view of an overhead door according to an embodiment of the present invention.

[0029] Referring to FIG. 1, an overhead door according to one embodiment of the present invention is an overhead door that uses a chain (50) to raise or lower the overhead door panel (21) to open and close it.

[0030] Specifically, the overhead door is composed of a first frame (11) positioned at the front and a second frame (12) positioned at the rear, and the first frame (11) and the second frame (12) are spaced apart from each other at a certain distance. Thus, an internal space is formed between the first frame (11) and the second frame (12).

[0031] Meanwhile, a guide rail (13) is formed at the rear of the second frame (12). The guide rail (13) consists of a lower rail formed vertically along the second frame (12) and an upper rail connected horizontally to the upper part of the lower rail, and the lower rail and the upper rail are connected by a curved section.

[0032] A plurality of overhead door panels (21) are each connected vertically by a hinge or hinge, and a drive shaft (30) is positioned on the upper part of the frame (11, 12) and rotated by a drive motor (31) positioned on one side.

[0033] A sprocket (40) is provided at each end of the drive shaft (30), and a sub-sprocket (41) is positioned at the lower part of the sprocket (40), that is, between the center axis of the sprocket (40) and the guide rail (13).

[0034] The chain (50) is positioned to engage with the sprocket (40) and the sub-sprocket (41), with one end fixedly connected to one side of the lower part of the bottom overhead door panel (21), and the other end connected to a weight (not shown) along the space between the first frame (11) and the second frame (12) and arranged to hang down.

[0035] As shown in FIG. 2, such an overhead door is equipped with a speed-sensitive drop detector (100) for the overhead door on the rear of the overhead door panel (21) to detect abnormal door drops, such as the breaking of the chain (50).

[0036] FIG. 2 is a perspective view of a speed-sensitive fall detector for an overhead door according to one embodiment of the present invention.

[0037] Referring to FIG. 2, a speed-sensitive drop detector (100) for an overhead door may include a housing (110), a pin (120), a coupling part (130), and a shaft (140).

[0038] The speed-sensitive drop detector (100) for an overhead door is a device for detecting an abnormal drop of an overhead door and activating a braking device, and the operating state changes by centrifugal force according to the rotational speed of the door, so that a mechanical lock occurs at a speed above a certain level to detect the drop.

[0039] The housing (110) may be formed in the shape of a disc with a first through hole (119) formed in the center. The housing (110) is provided to provide a space for the pin (120) to rotate and slide, and may be provided with a receiving portion (111) inside. That is, the receiving portion (111) may be provided in the shape of a groove that is lower than the surrounding area in cross-section. Here, the receiving portion (111) may be a path where the pin (120) is seated and moves at the same time. In addition, the housing (110) may induce the pin (120) to move at a speed above a certain speed to form a locked state.

[0040] The pin (120) can be rotatably coupled between the receiving portion (111) and the coupling portion (130) of the housing (110). That is, one side of the pin (120) can be coupled facing the receiving portion (111), and the other side can be coupled facing the coupling portion (130).

[0041] At this time, multiple pins (120) may be arranged along the outer circumference of the first through hole (119). Here, one side of the pin (120) may be rotatably connected. That is, one side of the pin (120) may be connected between the receiving portion (111) and the connecting portion (130) and connected to the inside of the connecting portion (130). Therefore, one side of the pin (120) is not exposed to the outside.

[0042] The pin (120) can slide along the outer circumference of the housing (110) on its other side. Here, the pin (120) can be rotated by the rotational force of the door transmitted through the shaft (140). That is, the pin (120) can rotate together with the rotation of the door. In the drawing, when the door is raised, the pin (120) can rotate clockwise. On the other hand, when the door is lowered, the pin (120) can rotate counterclockwise.

[0043] At this time, the pin (120) may operate differently depending on the speed of the door. That is, when the door is driven normally by the drive motor (31), the pin (120) may rotate with the same displacement along the inner circumference of the housing (110). That is, at a speed below a certain level, the pin (120) may rotate in a folded state due to gravity.

[0044] On the other hand, if the door falls abnormally, that is, if it descends at a speed faster than normal operation, the pin (120) may rotate with a displacement in which the other side deviates outward in a certain section due to centrifugal force. That is, if the speed exceeds a certain level, the folding of the pin (120) is delayed by centrifugal force in a certain section and may get caught on the housing (110). At this time, the pin (120) is stopped and does not rotate, but the rotational force applied from the shaft (140) is transmitted to the housing (110) and can rotate the housing (110).

[0045] In this way, the speed-sensitive drop detector (100) for an overhead door according to one embodiment of the present invention changes its operating state by centrifugal force according to the change in the rotational speed of the door and causes a mechanical lock, thereby quickly detecting the abnormal descent of the door and stably preventing the fall, so that human casualties and equipment damage caused by the fall of the door can be minimized.

[0046] The connecting part (130) may be formed in a circular ring shape in which a second through hole (119) communicating with the first through hole (119) of the housing (110) is formed. At this time, the connecting part (130) may be connected so that the second through hole (119) communicates with the first through hole (119). Here, the connecting part (130) may be connected to the housing (110) together with a pin (120).

[0047] One side of the shaft (140) can be inserted into the first through hole and the second through hole. That is, one side of the shaft (140) can be coupled to the housing (110). In addition, the other side of the shaft (140) can be connected to a sensing roller (60) that is provided to contact one side of the guide rail (90) (see FIG. 6). That is, the shaft (140) can transmit rotational force caused by the rotation of the door to the speed-sensitive drop detector (100) for the overhead door.

[0048] In this way, the speed-sensitive fall detector (100) for an overhead door according to one embodiment of the present invention operates mechanically without electrical control, thereby reliably preventing falls even in a power cut-off situation, and thus improving the reliability of the system.

[0049] FIG. 3 is a plan view (a) and an enlarged view (b) of a pin of a speed-sensitive drop detector for an overhead door according to one embodiment of the present invention.

[0050] Referring to FIG. 3(a), the housing (110) may be provided with a side wall (116) of a certain height and thickness along its outer circumference. Here, the side wall (116) may be provided with a thickness for forming a first coupling member (118). Additionally, the side wall (116) may be provided with a thickness greater than the thickness of the pin (120) so that the pin (120) is seated in the receiving portion (111) and rotates.

[0051] A first coupling member (118) may have a coupling means inserted and fixed therein for coupling the housing (110). Here, a plurality of first coupling members (118) may be formed at equal angles for uniform coupling. For example, four first coupling members (118) may be formed above, below, left, and right relative to the center (O) of the housing (110).

[0052] At this time, the side wall (116) may be provided with an acceleration section (114) in which the radius gradually increases outward from a point (S). Here, the point (S) may be the starting point of the acceleration section (114). That is, the acceleration section (114) is a section formed at a certain angle (θ) from the point (S), and the inner circumference of the housing (110) in the drawing may be gradually displaced upward. In other words, the thickness of the side wall (116) may be formed to gradually decrease from the point (S) in the acceleration section (114).

[0053] In addition, the side wall (116) may be provided with a stopping step (112) at the end opposite to a point (S) in the acceleration section (114). Here, the stopping step (112) may be the end point of the acceleration section (114). That is, the stopping step (112) may be a discontinuous section in the inner circumference of the housing (110). In other words, the inner circumference of the housing (110) can be formed with a step difference of a certain size (H) by the stopping step (112).

[0054] At this time, a point (S) of the acceleration section (114) can be positioned at the uppermost side of the side wall (116). That is, the point (S) can be positioned at the 12 o'clock direction in the drawing. By this, the pin (120) can naturally fold inward due to gravity during low-speed rotation. In addition, as the rotation of the pin (120) progresses, it can gradually unfold outward from the acceleration section (114) due to the increase in centrifugal force.

[0055] In addition, the angle (θ) formed by the stop step (112) with a point (S) of the acceleration section (114) relative to the center (O) of the housing (110) may be 35 to 55°. That is, the angle (θ) may be set so that the folding of the pin (120) is delayed by centrifugal force, thereby ensuring an acceleration section (114) sufficient for unfolding into the acceleration section (114).

[0056] At this time, the angle (θ) formed by the stop step (112) and a point (S) with respect to the center (O) of the housing (110) can be determined so that the pin (120) moves along the acceleration section (114) at a speed greater than a certain speed and then settles stably on the stop step (112) at an appropriate timing.

[0057] Here, when the angle (θ) is less than 35°, the distance of the acceleration section (114) is shortened, and the pin (120) reaches the stopping step (112) before it is fully extended. Therefore, the pin (120) is not caught by the stopping step (112) and does not detect the fall.

[0058] On the other hand, when the angle (θ) exceeds 55°, the acceleration section (114) is extended, and the pin (120) reaches the stop step (112) in an unfolded state even at a relatively low rotational speed. Therefore, the pin (120) gets stuck by the stop step (112) even in the low-speed section, causing a malfunction.

[0059] In addition, the width (H) of the stop step (112) may correspond to the width of the other side of the pin (120). That is, the width (H) of the stop step (112) may be formed to be equal to or larger than the width of the end (121) of the pin (120). Therefore, the pin (120) may be stably seated on the stop step (112) and may be caught with the housing (110).

[0060] In this way, the speed-sensitive drop detector (100) for an overhead door according to one embodiment of the present invention can improve the operating threshold speed and jamming stability by defining the acceleration section (114), the angle (θ) and width (H) of the stop step (112), and the corresponding structure of the pin, thereby ensuring reliable operation even in a repetitive operation environment.

[0061] The pin (120) folds inward due to gravity when the door is lowered at a speed below a certain level. That is, the pin (120) folds towards the center (O) due to gravity at a speed below a certain level and does not enter the acceleration section (114).

[0062] On the other hand, when the pin (120) exceeds a certain speed, the folding inward is delayed by centrifugal force and it unfolds outward. At this time, the pin (120) can enter the acceleration section (114) and be set by the stop step (112). In addition, the pin (120) is stopped by the stop step (112) and no longer rotates.

[0063] At the same time, the rotational force transmitted from the shaft (140) can be transmitted to the housing (110) through the pin (120) and the stop step (112). That is, the pin (120) is stopped from rotating by the stop step (112), but since the rotational force is transmitted to the housing (110) by the stop step (112), it can rotate together with the housing (110). By this, the speed-sensitive drop detector (100) for an overhead door can detect an emergency drop of the door.

[0064] In this way, the speed-sensitive drop detector (100) for an overhead door according to one embodiment of the present invention operates selectively only under critical conditions according to rotational speed, and due to the shape and asymmetric structure of the pin (120), it maintains a folded state at low speeds and unfolds only at high speeds to cause jamming, thereby suppressing unnecessary operation during normal operation, so that the frequency of inspection and wear of parts due to malfunction can be reduced, and thus maintenance costs can be reduced.

[0065] The coupling portion (130) may be provided with a third coupling member (132) for coupling with the housing (110). A coupling means for coupling the coupling portion (130) with the housing (110) and the pin (120) may be inserted and fixed into the third coupling member (132). Here, a plurality of third coupling members (132) may be formed at equal angles for uniform coupling. For example, four third coupling members (132) may be formed above, below, left, and right relative to the center (O) of the housing (110).

[0066] As such, the speed-sensitive drop detector (100) for an overhead door according to one embodiment of the present invention is made of a simple mechanical structure, which makes it easy to manufacture and secures cost competitiveness, thereby improving applicability in industrial sites.

[0067] Referring to FIG. 3(b), the pin (120) may be formed in a blade shape. Here, the pin (120) may include an end (121), an outer periphery (122), a protrusion (123), a recess (124), an inner side (125), and a second coupling member (126).

[0068] The end portion (121) is the other side of the pin (120) and serves to form a locking state by directly contacting the stop step (112). Here, the end portion (121) may be provided with a constant width corresponding to the width (H) of the stop step (112). Accordingly, when the end portion (121) is seated on the stop step (112), surface contact is made, allowing it to be seated stably.

[0069] The outer periphery (122) may be formed on the first side of the pin (120). At this time, the outer periphery (122) may be formed as a curve with a constant curvature (R). Here, the outer periphery (122) may be formed to curve toward the opposite side of the stop step (112). That is, the outer periphery (122) may be formed to curve toward the right in the drawing.

[0070] The protrusion (123) and the concave (124) may be provided on the inner side (125). Here, the inner side (125) may be formed on the second side facing the first side of the pin (120). This inner side (125) may be divided into three parts according to the protrusion (123) and the concave (124).

[0071] The protrusion (123) may be formed to protrude outwardly from the section extending from the second coupling member (126). That is, the inner side (125) may be formed to protrude outwardly from the second coupling member (126) to the protrusion (123). Accordingly, the first width (W1) of the protrusion (123) may be formed to be the widest width at the pin (120).

[0072] The concave portion (124) can be formed concavely inwardly in the section extending from the protrusion (123). That is, the inner side (125) can be formed concavely inwardly from the protrusion (123) to the concave portion (124). Accordingly, the second width (W2) of the concave portion (124) can be formed to be smaller than the first width (W1) of the protrusion (123).

[0073] The inner side (125) can be formed as a straight line or a curve from the concave portion (124) to the end portion (121). In this case, if the inner side (125) is curved, it can be formed with a curvature that is substantially similar to a straight line. Here, the width of the pin (120) can be formed to gradually decrease from the concave portion (124) to the end portion (121) due to the curvature of the outer side (122).

[0074] A second coupling member (126) may be formed on the other side of the pin (120) to be coupled with the housing (110) and the coupling part (130). A coupling means for coupling the pin (120) to the housing (110) and the coupling part (130) may be inserted and fixed into the second coupling member (126). Here, the second coupling member (126) may be coupled to the housing (110) so that the pin (120) can rotate.

[0075] At this time, the area (A1) on the outer periphery (122) side can be formed larger than the area (A2) on the inner side (125) side, based on the center line (O') from the center of the second coupling member (126) to the end (121). That is, the pin (120) can be formed with an overall shape that is extended outward to increase the mass distribution toward the outer periphery when rotated.

[0076] Accordingly, the pin (120) has an asymmetric structure with respect to the centerline (O'), so that when rotated, the centrifugal force acting on the outer periphery (122) is relatively large, and the inner periphery (125) has relatively small resistance. As a result, the pin (120) can be more easily unfolded outward at speeds above a certain level, and can maintain a folded state inward at low speeds.

[0077] Additionally, the inner side (125) between the concave portion (124) in the coupling portion is positioned between the coupling portion (130) and the housing (110), and the outer periphery (122) and the inner side (125) from the concave portion (124) to the end (121) can be positioned between the coupling portion (130) and the side wall (116) of the housing (110). By doing so, the inner side (125) of the pin (120) can rotate without interfering with the coupling portion (130), and the outer periphery (122) can be provided with space to move along the side wall (116). Thus, the pin (120) can rotate around the coupling portion (130) while simultaneously sliding along the side wall (116).

[0078] Meanwhile, the pin (120) can be formed such that the center of gravity of the pin (120) is located at 0.35L to 0.7L from the center of the second coupling member (126) with respect to the distance (L) from the center of the second coupling member (126) to the end (121). That is, the center of gravity of the pin (120) can be formed to be located on the upper side with respect to the entire distance of the pin (120). Accordingly, in the low-speed rotation section of normal operation, the pin (120) maintains a stable folded state due to gravity, and at a speed above a certain level, such as the drop of an abnormal door, the folding of the pin (120) is delayed and it can unfold outward due to centrifugal force.

[0079] Here, if the center of gravity of the pin (120) is closer than 0.35L from the center of the second coupling member (126), the influence of centrifugal force acts relatively strongly even at low speeds, causing the pin (120) to unfold prematurely and malfunction to occur in the normal driving section. On the other hand, if the center of gravity of the pin (120) is further than 0.7L from the center of the second coupling member (126), the pin does not unfold sufficiently even during high-speed rotation, so the catch on the stop step (112) is not smooth, and the fall detection function is degraded.

[0080] At this time, the curvature (R) of the outer periphery (122) of the pin (120) may be 0.66L to 0.8L. That is, the outer periphery (122) may be formed with a curvature (R) of 0.66 to 0.8 times the distance (L) of the pin (120). By doing so, the time delay characteristics of the folding and unfolding movements during rotation of the pin (120) can be secured.

[0081] Here, if the curvature (R) of the outer periphery (122) is less than 0.66L, the folding of the pin (120) occurs excessively quickly. That is, if the outer periphery (122) is curved more than a certain size, the folding of the pin (120) occurs excessively quickly. Therefore, even in high-speed sections, the pin (120) does not get caught on the stop step (112).

[0082] On the other hand, if the curvature (R) of the outer periphery (122) is greater than 0.8L, the pin (120) unfolds even at low speed. That is, if the curvature of the outer periphery (122) is too gentle, the pin (120) unfolds easily even at low speed. Therefore, even in the low speed section, the pin (120) gets caught on the stop step (112), causing a malfunction.

[0083] In addition, the first width (W1) at the protrusion (123) of the pin (120) may be 0.44L to 0.55L, and the second width (W2) at the concave portion (124) of the pin (120) may be 0.35L to 0.42L. At this time, W2:W1 may be 0.64 to 0.95:1. By doing so, the mass distribution and rotational inertia characteristics of the pin (120) can be adjusted to ensure a balance between responsiveness to centrifugal force and fold return characteristics.

[0084] Here, if W2:W1 is less than 0.64:1, that is, if the upper part (concave part (124)) of the pin (120) is too narrow compared to the lower part (protruding part (123)), the mass distribution and moment of inertia in the outer direction of the pin (120) are insufficient, so sufficient expansion does not occur due to centrifugal force, and thus the pin (120) does not expand smoothly even in the high-speed section, and the locking action by the stop step (112) becomes unstable.

[0085] On the other hand, if W2:W1 exceeds 0.95:1, that is, if the difference in width between the upper part (concave part (124)) of the pin (120) and the lower part (protruding part (123)) decreases, the mass distribution and moment of inertia in the outer direction of the pin (120) increase excessively, so that the pin (120) easily switches to an unfolded state even in a low-speed section, and thus a malfunction occurs when the stop step (112) gets caught even during normal operation.

[0086] Additionally, the area (A1) on the outer edge (122) side may be 1.1 to 1.6 times larger than the area (A2) on the inner edge (125) side. As a result, the pin (120) can induce outward expansion during rotation through an asymmetric mass distribution, while maintaining a fold due to gravity in the low-speed section.

[0087] Here, if the area (A1) on the outer periphery (122) side is less than 1.1 times the area (A2) on the inner side (125) side, the mass difference between the outer periphery (122) side and the inner side (125) side is reduced, so the moment due to the centrifugal force generated during rotation is not sufficiently secured. Consequently, the torque for the pin (120) to expand outward relative to the center of rotation is insufficient, so the pin cannot fully expand even in the high-speed section, and consequently, even when reaching the stop step (112), the engagement is incomplete or delayed.

[0088] On the other hand, if the area (A1) on the outer periphery (122) side exceeds 1.6 times the area (A2) on the inner side (125) side, the mass on the outer periphery (122) side increases excessively, and the outward unfolding torque due to centrifugal force exceeds the folding force due to gravity even in the low-speed section at the beginning of rotation. Consequently, the pin (120) is already switched to the unfolded state before reaching the intended critical speed, and as a result, even at normal driving speed, a jamming occurs due to the stop step (112), causing a malfunction in which a detection operation is performed even in a situation where it is not falling.

[0089] In this way, the speed-sensitive drop detector (100) for an overhead door according to one embodiment of the present invention can precisely set the responsiveness and operating sensitivity to centrifugal force by adjusting the center of gravity position, curvature, shape, and mass distribution of the pin (120), thereby enabling rapid detection even at short drop distances and responding to various door loads and drop conditions.

[0090] Hereinafter, the operation of a speed-sensitive fall detector for an overhead door according to an embodiment of the present invention will be described with reference to FIGS. 3 and FIGS. 5.

[0091] FIG. 4 is an operating state diagram of a speed-sensitive fall detector for an overhead door according to an embodiment of the present invention, and FIG. 5 is an operating state diagram of a speed-sensitive fall detector for an overhead door according to an embodiment of the present invention.

[0092] Referring to FIG. 4(a) and FIG. 5, in the case of low-speed operation where the door is normally driven by the drive motor (31), the pin (120) rotates at full speed in a counterclockwise direction. That is, when the door is normally lowered, the pin (120) continuously rotates in a counterclockwise direction so as not to catch on the stop step (112).

[0093] More specifically, when the end (121) of the pin (120) is at the 12 o'clock position, it is in a maximally upright state. Here, when the pin (120) rotates to the left, inward folding begins due to gravity. Afterward, the pin (120) rotates while maintaining the folded state.

[0094] At this time, the end (121) of the pin (120) moves and rotates with equal displacement along the inner circumference of the housing (110). Here, since the pin (120) maintains a folded state in the center (O) direction due to gravity, the end (121) does not enter the acceleration section (114). That is, the end (121) moves along the trajectory (T) and passes through the acceleration section (114) without getting caught on the stop step (112). Therefore, the pin (120) maintains a freely rotating state along the side wall (116) of the housing (110) below the stop step (112).

[0095] Referring to FIG. 4(b), in the case of high-speed operation where the door falls abnormally and rotates at a faster speed than normal operation, the pin (120) rotates at high speed in a counterclockwise direction. At this time, due to the abnormal fall of the door, the pin (120) rotates at high speed and stops by getting caught on the stop step (112) by centrifugal force.

[0096] More specifically, the pin (120) receives rotational force through the shaft (140) in response to the emergency drop of the door and rotates at high speed. At this time, the pin (120) can be extended outward as the centrifugal force increases, delaying the folding inward. Here, the end (121) of the pin (120) extends outward along the inner circumference of the housing (110) and enters the acceleration section (114), and is subsequently settled by the stop step (112). Therefore, the pin (120) stops rotating by the stop step (112) and does not rotate any further.

[0097] At this time, the pin (120) is stationary and does not rotate, but the rotational force applied from the shaft (140) is transmitted to the housing (110) and causes the housing (110) to rotate. That is, the housing (110) rotates with the pin (120) seated on the stop step (112). By this, the braking device is triggered as described below.

[0098] Here, an overhead door fall prevention device equipped with a speed-sensitive fall detector (100) for an overhead door according to one embodiment of the present invention may further include a link and a braking device.

[0099] FIG. 6 is an installation diagram of a speed-sensitive fall detector for an overhead door according to an embodiment of the present invention.

[0100] Referring to FIG. 6, the link (70) can be coupled between the outer surface of the housing (110) of the speed-sensitive fall detector (100) for the overhead door and the rotation axis (81) of the braking device (80). When the speed-sensitive fall detector (100) for the overhead door detects a high-speed fall, the link (70) can rotate in one direction according to the rotation of the housing (110).

[0101] A braking device (80) may be coupled to one side of a rotating shaft (8). Here, the braking device (80) may be provided on the lower side of a sensing roller (60). At this time, the braking device (80) may be provided in the form of a braking blade. Additionally, the sensing roller (60) may rotate in contact with a guide rail (90) (see FIG. 7). Here, the guide rail (90) may be the guide rail (13) of FIG. 1. Furthermore, the guide roller (61) is positioned on the inner side of the guide rail (90) and rotates along the guide rail (90) so that the door can be raised and lowered. A chain (50) may be mounted on the chain hanger (51).

[0102] FIG. 7 is a diagram showing the state of operation for preventing falls by a speed-sensitive fall detector for an overhead door according to one embodiment of the present invention.

[0103] Referring to FIG. 7(a), in the normal operating state of the door, the guide roller (61) descends along the guide rail (90). At this time, the sensing roller (60) also rotates along the guide rail (90), but rotates within a certain speed. In this case, the pin (120) of the speed-sensitive drop detector (100) for the overhead door does not catch on the stop step (112). Here, the housing (110) does not rotate, and therefore the link (70) does not move.

[0104] Referring to FIG. 7(b), in the emergency drop state of the door, the guide roller (61) rapidly descends along the guide rail (90). At this time, the sensing roller (60) also rapidly rotates along the guide rail (90), and the pin (120) catches on the stop step (112), stopping the rotation. Accordingly, the rotational force of the sensing roller (60) is transmitted to the housing (110) through the shaft (140), causing the housing (110) to rotate.

[0105] At this time, the braking device (80) can be triggered by the rotation of the link (70). That is, as the housing (110) rotates, the link (80) rotates upward. Accordingly, the braking device (80) also rotates upward. That is, the rotating side (81) rotates counterclockwise, causing the braking device (80) to rotate upward. Here, the braking device (80) can stop the falling door by contacting the guide rail (90) with friction. At this time, the braking device (80) can stop the falling door with strong friction by contacting the surface of the guide rail (90) by the braking blade.

[0106] Accordingly, by transmitting the rotational force of the fall detector (100) to the braking device (80) through the link (70), a fall prevention function can be implemented without a separate complex transmission structure, thereby simplifying the structure. Although an embodiment of the present invention has been described above, the concept of the present invention is not limited to the embodiments presented in this specification, and a person skilled in the art who understands the concept of the present invention may easily propose other embodiments by adding, changing, deleting, or adding components within the scope of the same concept, and such are also considered to fall within the scope of the concept of the present invention. Explanation of the symbols

[0107] 100 : Speed-sensitive fall detector for overhead doors 110 : Housing 111 : Reception area 112: Stopping step 114: Acceleration section 116 : Side wall 118 : First coupling 119 : Shaft insertion port 120 : Pin 121 : End 122 : Outer periphery 123: Protrusion 124: Concave 125 : Inner side 126 : Second connecting member 130: Connecting part 132: Third connecting part 140 : Shaft

Claims

Claim 1 A drop detector for detecting the fall of an overhead door including a guide rail, comprising: a housing having a disc shape with a first through hole formed in the center, a side wall provided along the outer circumference with a certain height and thickness, a receiving portion provided inside the side wall, an acceleration section provided in which the radius gradually increases outward from a point (S) on the side wall, a stopping step provided at the end opposite to the point on the acceleration section, wherein the point on the side wall is positioned at the uppermost side, and the stopping step has an angle (θ) formed with the point on the side wall with respect to the center of 35 to 55°; a coupling portion having a circular ring shape with a second through hole formed in communication with the first through hole of the housing and coupled to the first through hole; and a plurality of positions arranged at equal angles along the outer circumference of the first through hole between the receiving portion of the housing and the coupling portion, wherein one side is rotatably coupled, and the other side slides along the side wall, but folds inward at a speed below a certain speed, thereby accelerating A speed-sensitive drop detector for an overhead door comprising: a plurality of pins that, when a certain speed is exceeded without entering a section, are delayed inward folding by centrifugal force to enter the acceleration section and are seated by the stopping step to rotate the housing; and a shaft connected to a sensing roller, one end of which is inserted into the first through hole and the second through hole and coupled to the housing, and the other end of which is provided to come into contact with one side of the guide rail; wherein the sensing roller rotates in contact with the guide rail and detects the falling state of the overhead door according to the rotational speed. Claim 2 In claim 1, the pin is provided with a coupling member that is coupled to the housing on one side, the outer periphery of the first side is formed as a curve with a constant curvature (R), and the inner side of the second side opposite the first side is formed to protrude outward from the coupling member to a protrusion, is formed to be concave inward from the protrusion to a concave part, and is formed as a straight line or a curve from the concave part to the other side, a speed-sensitive drop detector for an overhead door. Claim 3 In paragraph 2, the area (A1) of the outer periphery side is larger than the area (A2) of the inner side side with respect to the center line from the center of the coupling member to the other side, the inner side between the coupling member and the concave part is positioned between the coupling part and the housing, and the outer periphery and the inner side from the concave part to the other side are positioned between the coupling part and the side wall, a speed-sensitive drop detector for an overhead door. Claim 4 In claim 3, the width (H) of the stop step corresponds to the width of the other side of the pin, and with respect to the distance (L) from the center of the coupling member to the other side, the center of gravity of the pin is located at 0.35L to 0.7L from the center of the coupling member, the curvature of the outer periphery of the pin is 0.66L to 0.8L, the first width (W1) at the protrusion of the pin is 0.44L to 0.55L, the second width (W2) at the concave part of the pin is 0.35L to 0.42L, W2:W1 is 0.64 to 0.95:1, and the area (A1) of the outer periphery side is 1.1 to 1.6 times larger than the area (A2) of the inner side side, for a speed-sensitive drop detector for an overhead door. Claim 5 An overhead door fall prevention device comprising: a speed-sensitive fall detector according to any one of claims 1 to 4; a link coupled to the outer surface of the housing of the speed-sensitive fall detector; and a braking device that is triggered by the rotation of the link and comes into close contact with a guide rail to stop a falling door by frictional force.

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