Ventilated safety cabinet with thermally actuated damper

Abstract

A safety cabinet includes an enclosure and at least one door to selectively seal the enclosure. The safety cabinet can be used to store, for example, flammable liquids, flammable waste, corrosive agents, pesticides, or combustible waste. The safety cabinet includes a heat-actuated damper including a body, a valve plate, and a pivot assembly. The valve plate is disposed within a passageway of the body such that the valve plate is movable between an open position and a closed position. The pivot assembly includes a biasing system adapted to bias the valve plate to the closed position and a fusible link interconnected between the body and the biasing system to limit movement of the valve plate from the open position to the closed position. The fusible link is configured to melt at a predetermined temperature, thereby allowing the biasing system to move the valve plate to the closed position.

Description

[0001] This application is a divisional application of the invention patent application entitled "Ventilated Safety Cabinet with Thermally Actuated Damper", with an international filing date of January 26, 2018, international application number PCT / US2018 / 015528, and national application number 201880003904.6. Technical Field

[0002] This disclosure generally relates to safety cabinets for the safe storage of flammable, combustible or other hazardous materials, and more particularly to safety cabinets equipped with a ventilation system having a thermally actuated damper. Background Technology

[0003] Safety cabinets can be used, for example, to store flammable materials on-site in a manufacturing workshop. Safety cabinets can be configured to protect the flammable materials stored within from the direct effects of an external fire, helping to prevent (at least for a specified period of time) the contents of the safety cabinet from igniting themselves and aggravating the adverse effects of the fire.

[0004] Ventilation of a safety cabinet is not typically required for fire protection. However, users of safety cabinets may wish to ventilate them in accordance with applicable law or internal standard operating procedures. In some cases, ventilating a safety cabinet can help reduce the amount of odorous flammable vapors and / or harmful vapors emitted by the materials stored inside. In such cases, it is desirable to install a ventilation system to avoid adversely affecting the intended performance of the safety cabinet during a fire. However, in practice, it may be difficult to ventilate a safety cabinet without compromising its specified fire resistance rating. In fact, ventilating a safety cabinet may impair its ability to protect its contents from fire. During a fire, vapors from the contents stored inside the safety cabinet can be emitted. If the ventilation system compromises the integrity of the safety cabinet, these flammable vapors can ignite, further exacerbating the destructive potential of the fire.

[0005] Previous safety cabinets included thermally actuated mechanisms for shutting off the ventilation system. However, such conventional mechanisms can be very expensive.

[0006] There is a persistent need in the field to provide additional solutions to enhance the ventilation of biosafety cabinets. For example, there is a constant need for technologies that enable biosafety cabinet ventilation using economical devices that help maintain the cabinet's performance in the event of a fire.

[0007] It should be understood that this description of the background art was constructed by the inventors to assist the reader and should not be construed as indicating that any of the problems pointed out were conceived in the art. Although the principles described may alleviate problems inherent in other systems in some aspects and embodiments, it should be understood that the scope of the protected innovation is defined by the appended claims and not by the ability of any disclosed feature to solve any specific problem described herein. Summary of the Invention

[0008] In one embodiment, a safety cabinet includes a housing, a door, and a ventilation system with a thermally actuated damper. The housing defines an interior, an opening, and a vent. The opening and the vent communicate with the interior of the housing. The door is rotatably mounted to the housing and is movable within a range of travel between an open position and a closed position. When in the closed position, the door is adapted to cover at least a portion of the opening of the housing.

[0009] The ventilation system includes a duct with an internal channel and a thermally actuated damper. The duct is connected to the housing such that the internal channel of the duct communicates with the vent of the housing. The thermally actuated damper includes a body, a valve plate, and a pivot assembly.

[0010] The body extends along a longitudinal axis and has a first end and a second end. The first end and the second end are arranged along the longitudinal axis in a spaced-apart relationship. The body defines an internal channel having a first opening at the first end and a second opening at the second end. The body includes a portion of the conduit such that the first end of the body communicates with the vent of the housing.

[0011] The valve plate is disposed within the channel of the body, such that it is interposed along the longitudinal axis between the first end and the second end of the body. The valve plate is movable between an open position and a closed position. When the valve plate is in the open position, it allows air to flow between the openings of the channel of the body, and when the valve plate is in the closed position, it substantially blocks the channel of the body.

[0012] The pivoting assembly includes a biasing system and a fusible link. The biasing system is mounted to the body such that it acts on the valve plate and is adapted to bias the valve plate to the closed position. The fusible link interconnects the body and the biasing system to form an interconnect therebetween, such that the valve plate is positioned in the open position. The fusible link restricts movement of the valve plate from the open position to the closed position via the interconnection between the body and the biasing system. The fusible link is configured to melt at a predetermined temperature, thereby releasing the interconnection between the biasing system and the body, and thereby allowing the biasing system to move the valve plate to the closed position.

[0013] In another embodiment, a damper is provided for the ventilation system of a safety cabinet. The damper includes a body, a valve plate, and a pivot assembly.

[0014] The body extends along a longitudinal axis and has a first end and a second end. The first end and the second end are arranged spaced apart from each other along the longitudinal axis. The body defines a channel having a first opening at the first end and a second opening at the second end.

[0015] The valve plate is disposed within the channel of the body, such that it is interposed along the longitudinal axis between the first end and the second end of the body. The valve plate is movable between an open position and a closed position. When the valve plate is in the open position, it allows air to flow between the openings of the channel of the body, and when the valve plate is in the closed position, it substantially blocks the channel of the body.

[0016] The pivoting assembly includes a valve support assembly, a biasing system, and a fusible link. The valve support assembly is mounted to the body and the valve plate. The valve support assembly is adapted to support the valve plate, allowing the valve plate to move between an open position and a closed position. The biasing system is mounted to the body and to at least one of the valve plate and the valve support assembly. The biasing system is adapted to bias the valve plate to the closed position. The fusible link interconnects the body and the biasing system to form an interconnect therebetween, such that the valve plate is positioned in the open position. The fusible link restricts movement of the valve plate from the open position to the closed position via the interconnection between the body and the biasing system. The fusible link is configured to melt at a predetermined temperature, thereby releasing the interconnection between the biasing system and the body, and thereby allowing the biasing system to move the valve plate to the closed position.

[0017] Further details, as well as optional aspects and features, of the disclosed principles will be understood from the following detailed description and accompanying drawings. It should be understood that the principles relating to the thermally actuated damper and safety cabinet disclosed herein can be implemented in other embodiments and different implementations, and can be modified in various aspects. Therefore, it should be understood that the foregoing general description and the following detailed description are merely exemplary and explanatory, and do not limit the scope of the disclosed principles. Attached Figure Description

[0018] Figure 1 This is a front view of an embodiment of a safety cabinet constructed according to the principles of this disclosure, showing a pair of doors in the closed position.

[0019] Figure 2 yes Figure 1 The top view of the safety cabinet, with its top panel removed for illustrative purposes.

[0020] Figure 3 yes Figure 1 A perspective view of the safety cabinet, showing the door in the open position.

[0021] Figure 4 yes Figure 1 A perspective view of the safety cabinet, showing the right door with the outer panel removed for illustrative purposes.

[0022] Figure 5 From Figure 4 A magnified detail image of the portion shown by circle V.

[0023] Figure 6 From Figure 1 The enlarged detail view shows an embodiment of a thermally actuated damper constructed according to the principles of this disclosure, as indicated by circle VI.

[0024] Figure 7 Is it like this? Figure 6 The view shown, but in sectional form.

[0025] Figure 8 This is a perspective view of an embodiment of a thermally actuated damper constructed according to the principles of this disclosure.

[0026] Figure 9 yes Figure 8 Exploded view of a thermally actuated damper.

[0027] Figure 10 yes Figure 8 A perspective view of the valve plate of a thermally actuated damper.

[0028] Figure 11 yes Figure 10 A front view of the valve plate.

[0029] Figure 12 yes Figure 8 A perspective view of the drive rod of a thermally actuated damper.

[0030] Figure 13 yes Figure 12 Side front view of the drive lever.

[0031] Figure 14 yes Figure 12 The front view of the end of the drive rod.

[0032] Figure 15 yes Figure 8 A perspective view of the pivot arm of a thermally actuated damper.

[0033] Figure 16 yes Figure 15 Side front view of the pivot arm.

[0034] Figure 17 yes Figure 8 A front view of the first end of a thermally actuated damper, showing the thermally actuated damper in the open position.

[0035] Figure 18 yes Figure 8 A first front view of the thermally actuated damper, showing the thermally actuated damper in the open position.

[0036] Figure 19 yes Figure 8 A front view of the second end of the thermally actuated damper, showing the thermally actuated damper in the open position.

[0037] Figure 20 It is along Figure 17 The line XX-XX in the middle is intercepted Figure 8 Cross-sectional view of the thermally actuated damper.

[0038] Figure 21 Is it like this? Figure 17 The image shown is a view of the thermally actuated damper in the off position.

[0039] Figure 22 Is it like this? Figure 18 The image shown is a view of the thermally actuated damper in the off position.

[0040] Figure 23 Is it like this? Figure 19 The image shown is a view of the thermally actuated damper in the off position.

[0041] Figure 24 It is along Figure 21 The line XXIV-XXIV in the middle is intercepted Figure 8 Cross-sectional view of the thermally actuated damper.

[0042] Figure 25 yes Figure 23 A cross-sectional view, but shown in perspective.

[0043] Figure 26 yes Figure 24 A cross-sectional view, but shown in perspective.

[0044] It should be understood that the accompanying drawings are not necessarily drawn to scale, and the disclosed embodiments are shown in illustrative and partial views. In some cases, details that are not necessary for understanding this disclosure or that make other details difficult to understand have been omitted. It should be understood that this disclosure is not limited to the specific embodiments shown herein. Detailed Implementation

[0045] This disclosure relates to embodiments of safety cabinets equipped with a ventilation system having at least one thermally actuated damper, said at least one thermally actuated damper operating in response to an increased ambient temperature to place the safety cabinet's ventilation system in a closed position to further protect the contents stored inside the safety cabinet from exposure to open flames and / or increased temperatures due to a fire near the safety cabinet. To help ensure that the safety cabinet's ventilation system mechanically closes in the event of a fire, this disclosure relates to an embodiment of a thermally actuated damper adapted to close the safety cabinet's ventilation system when ambient thermal conditions exceed a threshold level. In an embodiment, the thermally actuated damper includes a thermally actuated fusible link (e.g., a fusible link rated for 135°F or 165°F) to release and close a valve plate of the damper in the event of thermal conditions that cause the link to melt. When the fusible link melts, a spring can be used to close the valve plate against a valve seat defined in the body of the damper. In an embodiment, a simple and economical spring-loaded butterfly valve plate is provided as a shut-off damper.

[0046] In embodiments following the principles of this disclosure, the thermally actuated damper includes a body made of stainless steel to enhance corrosion resistance and frictional sparking. In embodiments, the damper may include a brass bushing and washer at a pivot position to help reduce corrosion and friction caused by components moving relative to each other. In embodiments, the mass of the body, its seat, and its valve plate helps increase the thermal barrier to suppress the migration of heat generated in a fire occurring outside the safety cabinet into the interior of the cabinet.

[0047] In an embodiment, the safety cabinet may include a pair of vents (e.g., a low vent and a high vent) communicating with the interior of the housing. The ventilation system may include duct sections connected to the housing, such that they communicate with the pair of vents respectively. Each duct section may have an associated thermally actuated damper constructed according to the principles of this disclosure. In the event of a fire that subjectes the damper of the safety cabinet to ambient temperatures that would cause the corresponding fusible link to melt, the valve plate of each damper closes to prevent air from flowing into or out of the safety cabinet housing through the duct section.

[0048] In conventional ventilation systems, rigid metal conduits (e.g., two-inch National Standard Pipe Thread (NPT) tubing) are used for the conduit sections. Rigid conduits are typically used to help maintain the performance of the safety cabinet during a fire. In embodiments, dampers constructed according to the principles of this disclosure can be used without using rigid metal conduits in the ventilation system connected to the damper. In embodiments, the damper may include a connector configured for use with plastic tubing (e.g., polyvinyl chloride (PVC) tubing) while substantially maintaining the fire resistance rating of the safety cabinet. In such cases, the damper body and the main body of the valve plate can serve as a thermal barrier for the interior of the safety cabinet. In embodiments, optional cabinet connectors can be configured to accommodate flexible tubing, pipework, etc.

[0049] Now turn to the attached image, Figure 1 An embodiment of a safety cabinet 30 constructed according to the principles of this disclosure is shown. The safety cabinet 30 can be used to store flammable, combustible, or other hazardous substances.

[0050] In one embodiment, the safety cabinet 30 includes a housing 32, at least one door 40, and a ventilation system 48 equipped with at least one thermally actuated damper 50 constructed according to the principles of this disclosure. (See also...) Figure 1 and 2 In the illustrated embodiment, the safety cabinet 30 includes a housing 32, a pair of doors 38, 40, and a mechanism for holding the doors 38, 40 in the open position. Figure 2 ) holding system 42, for automatically closing doors 38, 40 so that they are in the open position (see example) Figure 2 Move to the closed position (see example) Figure 1 The closing system 44, for latching doors 38, 40 in the closed position to cover the opening in the housing 32 (see also...) Figure 3 and Figure 4 The safety cabinet 30 includes a latching system 46 and a ventilation system 48 with a pair of thermally actuated dampers 50 (both constructed according to the principles of this disclosure). The safety cabinet 30 has a double-wall structure.

[0051] refer to Figure 1 and 2The safety cabinet 30 includes an outer shell 32 (which has an outer shell 34 and an inner shell 36), a left door 38, and a right door 40. The outer shell 32 includes the inner shell 36 to provide a double-walled structure, wherein each outer wall of the outer shell 34 has a corresponding inner wall of the inner shell 36, and the respective inner and outer walls are separated by a predetermined distance to define an insulating air space. The left door 38 and the right door 40 both have a similar double-walled structure to the outer shell 32.

[0052] refer to Figure 3 The outer casing 32 also includes a top side post 52, a bottom side post 53, a left side post 54, and a right side post 55. The side posts 52, 53, 54, and 55 of the outer casing 32 define and define an opening 57 leading to the interior 59 defined by the outer casing 32. The opening 57 communicates with the interior 59 of the outer casing 32.

[0053] refer to Figure 1-3 In one embodiment, the outer casing 32 defines at least one vent 62 communicating with the interior 59 of the outer casing 32. In the illustrated embodiment, the outer casing 32 defines a pair of vents 62, 64 extending through both the outer casing 43 and the inner casing 36, such that the vents 62, 64 allow communication between the external atmosphere near the safety cabinet 30 and the interior 59 of the outer casing 32 via each vent 62, 64. In the illustrated embodiment, the lower vent 62 on the left is configured as an exhaust port allowing vapor from the bottom of the outer casing 32 to exit therefrom, and the upper vent 64 on the right is configured as a fresh air intake port, allowing ambient air to enter the casing to supplement the exhaust flow exiting the outer casing 32 via the lower vent 62.

[0054] In an embodiment, the safety cabinet may be provided with a vent plug 65 (with a removable cap) configured to be positioned at vents 62, 64 (see...). Figure 6 The housing 32 is connected to the corresponding conduit section 67 of the ventilation system 48. In an embodiment, the conduit 67 (e.g., a tube with a two-inch NPT thread) can be connected to each vent plug 65 to attach the corresponding conduit section (which, as those skilled in the art will understand, may also include suitable tubing).

[0055] refer to Figure 1 In one embodiment, the safety cabinet 30 includes at least one door 38, 40, which, when in a closed position, is adapted to cover at least a portion of an opening in the housing 32. Each door 38, 40 is rotatably mounted to the housing 32 such that it can move within a range of travel between an open position and a closed position. In the illustrated embodiment, the safety cabinet 30 includes a pair of doors 38, 40 configured to cooperate together to close an opening 57 leading to the interior 59 of the housing 32 of the safety cabinet 30. In other embodiments, the safety cabinet 30 may include a single door configured to close the opening to the interior of the housing.

[0056] As Figure 1 and 2 As clearly shown, the left door 38 and right door 40 selectively cover the opening 57 of the outer casing 32 and are movable within a range of travel between a closed position and a series of open positions, respectively. The left door 38 and right door 40 are adapted to cover the opening 57 of the outer casing 32 when in the closed position. The doors 38, 40 of the safety cabinet 30 (which may have a double-walled structure to provide an insulating air space therebetween) can be placed in a closed position to help protect the contents stored therein from open flames and / or the adverse effects of elevated ambient temperatures in the event of a fire.

[0057] refer to Figure 1 The left door 38 and the right door 40 are preferably rotatably mounted to the housing 32 via a first hinge 68 and a second hinge 69, respectively. The first hinge 68 is mounted to the left side post 53 of the housing 32 and the left door 38. The second hinge 69 is mounted to the right side post 54 of the housing 32 and the right door 40. Both the first hinge 68 and the second hinge 69 extend over approximately the entire height of the left door 38 and the right door 40, respectively.

[0058] In some embodiments, the safety cabinet 30 may include means for automatically closing the doors. In one embodiment, the safety cabinet 30 includes a first actuator and a second actuator adapted to push the first door and the second door to a closed position, respectively. (Reference) Figure 2 In the illustrated embodiment, a first actuator and a second actuator, in the form of cylinders 71 and 72, are attached to the left door 38 and the right door 40, respectively, and to the housing 32. Cylinders 71 and 72 are adapted to bias the left door 38 and the right door 40 to their closed positions.

[0059] However, when loading and unloading the safety cabinet 30, it may be desirable to keep the doors 38, 40 in the open position. In some embodiments, the safety cabinet 30 may include means for selectively holding the doors 38, 40 in the open position. In the illustrated embodiment, a first door holding mechanism and a second door holding mechanism 73, 74 are respectively provided to selectively hold the doors 38, 40 in the open position, such as... Figure 2 As shown.

[0060] In some embodiments, each door retaining mechanism 73, 74 includes retaining elements 77, 78 adapted to be selectively connected to fusible links 79, 80 to retain doors 38, 40 in the open position. Door retaining mechanisms 73, 74 are mounted to housing 32 and selectively connected to the left door 38 and the right door 40, respectively. In some embodiments, the first and second retaining elements 77, 78 each have a pawl feature for selectively retaining the respective door 38, 40 in the open position.

[0061] The fusible links 79 and 80 of the holding system 42 can be configured to melt when the ambient temperature reaches a certain level. When doors 38 and 40 are held open by door holding mechanisms 77 and 78, respectively, and the ambient temperature exceeds a threshold level, links 79 and 80 melt, thereby releasing doors 38 and 40 and allowing cylinders 71 and 72 of the closing system 44 to move doors 38 and 40 toward the closed position, respectively. In some embodiments, the fusible links 79 and 80 are configured to melt when the ambient temperature exceeds approximately 165°F.

[0062] In one embodiment, the left door 38 includes an inner sealing flange 82, and the right door 40 includes an outer sealing flange 83. The sealing flanges 82, 83 extend substantially along the entire height of the doors 38, 40 to which they are attached. Each sealing flange 82, 83 is adapted to extend from its attached respective door 38, 40 to a position where it overlaps with the other door 40, 38 when the door 38, 40 is in the closed position.

[0063] In an embodiment, to create a more effective seal, the inner and outer sealing flanges 82 and 83 of the left door 38 and the right door 40 are arranged such that the inner sealing flange 82 of the left door 38 is arranged inward relative to the right door 40, and the outer sealing flange 83 of the right door 40 is arranged outward relative to the left door 38. In an embodiment, a suitable orderly closing system 90 can be provided, adapted to coordinate the closing of doors 38 and 40 such that the left door 38 closes before the right door 40. In an embodiment, any suitable orderly closing system 90 can be used, for example in… Figure 2 An ordered door closing system is shown in [the document] and further described, for example, in U.S. Patent Application Publication No. US2013 / 0200767. In other embodiments, an ordered door closing system constructed according to the principles described in U.S. Patent US6729701 may be used.

[0064] When doors 38 and 40 close in the sequence that the left door 38 is closed before the right door 40 is closed, and then the right door 40 moves to the closed position, the sealing flanges 82 and 83 cooperate to form an effective seal between doors 38 and 40, thereby further protecting the contents stored in the safety cabinet 30 from the influence of the external environment. When sealed in this manner, the entry of flames and high-temperature air into the outer shell 32 of the safety cabinet 30 can be further prevented.

[0065] In an embodiment, the safety cabinet 30 may include any suitable latching system 46 adapted to help hold the doors 38, 40 in the closed position. In an embodiment, the latching system 46 may be a three-point latching system with various configurations, including impact latch types that allow the doors 38, 40 to move from the open position to the closed position without any operation.

[0066] refer to Figure 3-5 In one embodiment, the latching system 46 includes a bullet impact latch 102, first and second latch lever assemblies 104 and 105, and a paddle handle 107 (see also...). Figure 1 In the illustrated embodiment, both the first and second latch assemblies 104, 105 include distal bullet impact latches 108, 109 as described in U.S. Patent US9630036. The paddle 107 is adapted to selectively actuate the latch system 46 to move the distal ends 108, 109 of the latch assemblies 104, 105 and the bullet impact latch 102 from an extended position to a retracted position, in which the doors 38, 40 can be moved from a closed position to one of a series of open positions.

[0067] Actuating the paddle 107 moves the latch lever assemblies 104, 105 toward each other in opposite latch lever retraction directions, which correspondingly moves the distal bullet impact latches 108, 109 to the retracted position. Actuating the paddle 107 also moves the bullet impact latch 102 to the retracted position along the impact latch retraction direction. The bullet impact latch 102 and the first and second latch lever assemblies 104, 105 are adapted to bias the latch members to the extended position and also allow the latch members to move from the extended position to the corresponding retracted position in response to the door 40 moving from the open position to the closed position (in other words, when it is "impacted" closed).

[0068] refer to Figure 3 and 4 To facilitate maintenance operations on the latching system 46, for example, the inner panel of the right door 40 includes an operating hole 135 covered by a removable cover plate 137. The operating hole 135 is arranged such that the proximal ends of the paddle handle 107, the latch lever assemblies 104, 105, and the bullet impact latch 102 can be easily accessed through the hole 135. For example, the latching system 46, including the bullet impact latch 102 and the latch lever assemblies 104, 105, may be similar in structure, operation, and other respects to that described in U.S. Patent 9630036, which is incorporated herein by reference. In other embodiments, as those skilled in the art will understand, the latching system 46 may have different arrangements. For example, in other embodiments, the latching system 46 may have a structure based on the principles illustrated and described in U.S. Patent 6729701, which is incorporated herein by reference.

[0069] refer to Figure 1In the illustrated embodiment, the safety cabinet 30 includes a ventilation system 48 that vents to the outside to ensure that the ability of the safety cabinet 30 to meet the ten-minute fire resistance test performance rating according to the standard time-temperature profile specified in §1910.106, which is incorporated herein by reference, is given in NFPA 251-1969, "Standard Methods of Fire Tests of Building Construction and Materials". In this embodiment, the ventilation system 48 may be used to meet requirements in some jurisdictions regarding ventilating the safety cabinet 30 to prevent vapor buildup within the cabinet and to remove toxic or harmful fumes emitted from the contents stored within the safety cabinet 30.

[0070] In one embodiment, the ventilation system 48 is mounted to the housing 32 such that the ventilation system 48 communicates with at least one vent 62, 64 of the housing 32. In another embodiment, the ventilation system 48 includes a conduit 145 having an internal passage 147 and a thermally actuated damper 50. The conduit 145 is connected to the housing 32 such that the internal passage 147 of the conduit 145 communicates with the vent 62 of the housing 32.

[0071] In the illustrated embodiment, the ventilation system 48 includes a first duct 145 communicating with a lower vent 62, a second duct 148 communicating with an upper vent 64, first and second dampers 50 associated with the first and second ducts 145 and 148 respectively, and an exhaust fan 149 communicating with the first duct 145. In this embodiment, each exhaust port 62, 64 may be equipped with a suitable flash arrestor screen known to those skilled in the art. In the illustrated embodiment, the lower exhaust port 62 serves as an exhaust outlet through which air is drawn from inside the housing 32, and the upper exhaust port 64 serves as a fresh air inlet through which ambient air from outside the safety cabinet 30 is delivered to the housing 32 of the safety cabinet 30.

[0072] In one embodiment, the exhaust fan 149 can be any suitable fan adapted to draw air from the interior of the housing 32 of the safety cabinet 30 through the first duct 145. In another embodiment, the exhaust fan 149 includes spark-free fan blades and a spark-free shroud. In yet another embodiment, the exhaust fan 149 is arranged such that air from the interior of the safety cabinet 30 is exhausted directly to the outside of the structure containing the safety cabinet 30.

[0073] In the illustrated embodiment, the thermally actuated dampers 50 have substantially the same structure and operate in a similar manner. Each damper 50 is arranged within a corresponding conduit 145, 148 to form part of an internal channel 147 (see [link]). Figure 7 ).

[0074] Each thermally actuated damper 50 is adapted to be in the open position under normal ambient temperature conditions (see Figure 20 This allows the ventilation system 48 to draw air from the interior of the housing through the first duct 145 and deliver fresh intake air to the housing 32 through the second duct. Each thermally actuated damper 50 is adapted to move to a closed position when the temperature it withstands exceeds a predetermined threshold (see [link to relevant documentation]). Figure 24 This causes the conduit in which the thermally actuated damper 50 is placed to be blocked, thereby essentially preventing airflow from entering or leaving the housing 32 through the vents 62 and 64.

[0075] Figure 8-26 It shows Figure 1 The thermally actuated damper 50 of the safety cabinet 30 (or a component thereof). It should be understood that this description of the thermally actuated damper 50 also applies to other thermally actuated dampers 50. Reference Figure 8 and 9 In one embodiment, the thermally actuated damper 50 includes a body 150, a valve plate 152, and a pivot assembly 154. In the illustrated embodiment, the thermally actuated damper 50 includes a body 150, a valve plate 152, a pivot assembly 154 having a fusible link 157, and a coupling 159.

[0076] In this embodiment, those skilled in the art will understand that any suitable technique can be used to manufacture the components of the damper 50. In this embodiment, the components of the damper 50 can be produced using known machining techniques, including computer numerical control (CNC) machining, or a combination of castings and machined parts. In this embodiment, the assembly of the damper 50 can be performed externally to the housing body 150, except for positioning the valve plate 152 on the valve seat of the body 150.

[0077] refer to Figure 9 The body 150 extends along the longitudinal axis LA and has a first end 171 and a second end 172. The ends 171 and 172 are arranged spaced apart from each other along the longitudinal axis LA. The body 150 defines an internal channel 173 having a first opening 174 disposed at the first end 171 and a second opening 175 disposed at the second end 172 (see also...). Figure 20 ). refer to Figure 7 The body 150 includes a portion of the conduit 148 such that the opening 174 of the first end 171 of the body 150 communicates with the upper exhaust port 64 of the housing 32.

[0078] refer to Figure 7 and 20In one embodiment, at least one of the first end and the second end 171, 172 of the body 150 includes a threaded surface 178 configured to thread into a suitable pipe section (e.g., connector 159). In the illustrated embodiment, both the first end and the second end 171, 172 of the body 150 include threaded surfaces 177, 178, which in the illustrated embodiment include external threaded surfaces. In other embodiments, the body 150 may include at least one internal threaded surface arranged adjacent to at least one of its first end and the second end 171, 172.

[0079] refer to Figure 23 The damper body 150 includes an outer surface 181 and an inner surface 182. The inner surface 182 is generally cylindrical and defines its channel 173. The outer surface 181 is radially circumscribed relative to the inner surface 182.

[0080] In one embodiment, the body 150 defines a suitable valve seat 183 for sealing engagement with the valve plate 152. In the illustrated embodiment, the inner surface 182 has a first protrusion 184 and a second protrusion 185 defining the valve seat 183. The first and second protrusions 184, 185 are positioned opposite each other such that they extend radially inward toward each other. The first protrusion 184 is disposed adjacent to a first end 171 of the body 150 and includes a first valve seat surface 187 extending radially inward and facing the second end 172 of the body 150, and the second protrusion 185 includes a second valve seat surface 188 extending radially inward and facing the first end 171 of the body 150. The first and second protrusions 184, 185 are similar in shape and size and include an arcuate segment (see, for example...). Figure 9 ).

[0081] refer to Figure 24 The valve seat 183 includes a first valve seat surface and second valve seat surfaces 187 and 188. In the illustrated embodiment, the first valve seat surface and the second valve seat surface are arranged along the longitudinal axis LA in an offset relationship from each other, the offset being approximately equal to the thickness of the valve plate 152.

[0082] refer to Figure 9 In one embodiment, body 150 defines a transverse bore 191 extending radially from outer surface 181 to inner surface 182. The transverse bore 191 can be configured to allow operation of valve plate 152 by pivot assembly 154. In the illustrated embodiment, body 150 defines a pair of transverse bores 191, 192. The transverse bores 191, 192 are opposite to each other, and both extend radially from outer surface 181 to inner surface 182.

[0083] In the illustrated embodiment, the body 150 includes a connecting rod anchor 194 configured to secure the fusible connecting rod 157 thereto. The connecting rod anchor 194 protrudes outward from the body 150.

[0084] refer to Figure 9-11 The valve plate 152 includes a generally flattened disk configured to selectively block a passage 137 of the body 150. The valve plate 152 includes a central rib 201 defining first and second threaded holes 203, 205 therein, the threaded holes being configured to threadedly engage portions of the pivot assembly 154 to allow rotational movement of the valve plate 152 between an open position and a closed position. The valve plate includes a drive member engagement portion 207 corresponding to the first threaded hole 203. The engagement portion 207 is configured to be rotatably coupled to a drive member 210 of the pivot assembly 154 to allow the pivot assembly 154 to selectively rotate the valve plate 152 relative to the body 150.

[0085] refer to Figure 20 and 24 A valve plate 152 is disposed within a channel 173 of the body 150, such that the valve plate 152 is positioned intermediary between the first end 171 and the second end 172 of the body 150 along the longitudinal axis LA. The valve plate 152 can be in an open position (e.g., Figure 20 (as shown) and closing position (as shown) Figure 24 The valve plate 152 moves between the openings 174 and 175 of the passage 173 of the body 150 when the valve plate 152 is in the open position. When the valve plate 152 is in the closed position, the valve plate 152 substantially blocks the passage 173 of the body 150 to substantially prevent the flow of air between the openings 174 and 175 of the passage.

[0086] In the illustrated embodiment, when the valve plate 152 is in the closed position, the valve plate 152 contacts and engages with the first protrusion 184 and the second protrusion 185. The pivot assembly 154 is operable to cause the valve plate 152 to move about the pivot axis PA in the closing direction 214. Figure 20 The opening position pivots to Figure 24 The closed position. Valve plate 152 includes a first surface 211 and a second surface 212 opposite to the first surface 211 (see also...). Figure 10 The first and second surfaces 211 and 212 are both circular and have approximately the same size. The first and second valve seat surfaces 187 and 188 are configured to interfere with the first and second surfaces 211 and 212 of the valve plate 152, respectively, to prevent the valve plate 152 from rotating further about the pivot axis PA in the closing direction 214.

[0087] refer to Figure 9The pivot assembly 154 is adapted to selectively move the valve plate 152 from the open position to the closed position when the ambient thermal conditions of the damper 50 exceed a threshold level. The pivot assembly 154 can be connected to the body 150 and the valve plate 152. The illustrated pivot assembly 154 includes a valve support assembly 221, a biasing system 223, and a fusible link 157.

[0088] In one embodiment, valve support assembly 221 is adapted to support valve plate 152 such that valve plate 152 is movable between an open position and a closed position. In the illustrated embodiment, valve support assembly 221 is adapted to support valve plate 152 such that valve plate 152 is rotatably movable about pivot axis PA between an open position and a closed position. In another embodiment, valve support assembly 221 is mounted to body 150 and valve plate 152.

[0089] In the illustrated embodiment, the valve support assembly 221 includes: a pair of bushings 231, 232; a pair of trunnion members 234, 235; a pair of washers 237, 238; and a support sleeve 239. The bushings are at least partially disposed within a transverse bore of the body 150. In this embodiment, the bushings 231, 232 can be made of any suitable material. For example, in this embodiment, the bushings 231, 232 can be made of a material that suppresses electrical sparks generated by friction caused by relatively moving parts. In this embodiment, the bushings 231, 232 are made of suitable brass.

[0090] refer to Figure 17 and 21 Trunnion members 234 and 235 are connected to valve plate 152 such that they extend from valve plate 152 into transverse holes 191 and 192 of body 150, respectively. Trunnion members 234 and 235 and valve plate 152 are pivotable relative to body 150 about pivot axis PA. Trunnion members 234 and 235 each include distal ends 241 and 242. Trunnion members 234 and 235 extend from valve plate 152 into bushings 231 and 232 such that the distal ends 241 and 242 of trunnion members 231 and 232 are arranged laterally outward from bushings 231 and 232, and a corresponding washer 237 and 238 is interposed therebetween. Trunnion members 234 and 235 extend through bushings 231 and 232 respectively, such that the distal ends 241 and 242 of each trunnion member 234 and 235 are arranged in an external relationship relative to the corresponding bushings 231 and 232, so that the distal ends 241 and 242 of the trunnion members 231 and 232 provide a capture connection between the valve plate 152 and the body 150.

[0091] In the illustrated embodiment, valve support assembly 221 is adapted to support valve plate 152 such that valve plate 152 is rotatably movable about pivot axis PA between an open position and a closed position. When moving from the open position to the closed position, valve plate 152 rotates about pivot axis PA in the closing direction 214. In the embodiment, at least one of the first and second protrusions 184, 185 of body 150 is configured such that the at least one of the first and second protrusions 184, 185 defines the positioning of the closed position (see also) by interferingly engaging valve plate 152 to prevent further rotation of valve plate 152 from the open position along the closing direction 214 about pivot axis PA. Figure 25 and 26 ).

[0092] refer to Figure 8 The biasing system 223 is adapted to bias the valve plate 152 to the closed position. In an embodiment, the biasing system 223 is mounted to the body 150 such that it acts on the valve plate 152 and is adapted to bias the valve plate 152 to the closed position. In an embodiment, the biasing system 223 is mounted to the body 150 and to at least one of the valve plate 152 and the valve support assembly 221.

[0093] refer to Figure 9 In the illustrated embodiment, the biasing system 223 includes a drive member 210 and a spring 251. (See reference...) Figure 19 and 23 The drive member 210 defines the pivot axis PA. The drive member 210 extends through the first transverse hole 191 of the body 150 (see also...). Figure 9 A drive member 210 is coupled to a valve plate 152 such that rotational movement of the drive member 210 about a pivot axis PA correspondingly rotates the valve plate 152. A spring 251 is mounted to the body 150 and the drive member 210 such that the spring 251 applies a spring force to the drive member 210, the spring force being configured to rotate the drive member 210 about the pivot axis PA in a closing direction 214 when the fusible link 157 melts, thereby moving the valve plate 152 from an open position to a closed position (see also...). Figure 18 and 22 ).

[0094] refer to Figure 9 In the illustrated embodiment, the drive member 210 of the damper 50 includes a drive sleeve 253 and a pivot arm 255. The drive sleeve 253 extends along the pivot axis PA through one of the transverse holes 191 in the body 150. (See reference...) Figure 9 and Figure 12-14The drive sleeve 253 includes an inner end 257 and an outer end 258. The inner end 257 of the drive sleeve 253 is coupled to the valve plate 152, such that rotational movement of the drive member 210 about the pivot axis PA correspondingly rotates the valve plate 152. In the illustrated embodiment, the inner end 257 includes a valve plate socket configured to engagely receive an engagement portion 207 of the valve plate 152. The outer end 258 of the drive sleeve 253 is arranged externally relative to the outer surface 181 of the body 150.

[0095] refer to Figure 15 and 16 The pivot arm 255 includes a proximal end 260 defining a generally square opening 261, said opening being configured to engagely receive an outer end 258 of a drive sleeve 253 therein. The pivot arm 255 also includes a distal end 263 defining a mounting hole 265 therethrough, said mounting hole being configured to threadedly receive a link fastener 267 (see also...) Figure 9 This helps secure the connecting rod 157 to the biasing system 223. The pivot arm 255 also defines a spring mounting hole 269 therein, configured to hold one end of the spring 251 therein. In the illustrated embodiment, the spring mounting hole has a chamfered (or frustoconical) shape to facilitate insertion of the end of the spring 251 therein. Reference Figure 18 and 21 The pivot arm 255 is mounted to the drive sleeve 253 near the outer end 258 of the drive sleeve, such that the distal end 263 of the pivot arm 255 protrudes from the drive sleeve 253.

[0096] refer to Figure 21 Spring 251 is connected to pivot arm 255 via a spring mounting hole defined by pivot arm 255. (See reference) Figure 22 In the illustrated embodiment, the body 150 defines a second spring mounting hole 271 therein to retainably receive the other end of the spring 251. In this embodiment, the spring 251 is mounted to the body 150 and the pivot arm 255 such that the spring 251 applies a spring force to the drive sleeve 253, the spring force being configured to rotate the drive member 210 about the pivot axis PA in the closing direction 214 to move the valve plate 152 from the open position to the closed position.

[0097] refer to Figure 17 and 18A fusible link 157 interconnects between the body 150 and the biasing system 223 to form an interconnect therebetween, such that the valve plate 152 is positioned in the open position. In one embodiment, the fusible link 157 is retainably connected to the drive member 210 to limit rotational movement of the drive member 210 about the pivot axis PA, such that the valve plate 152 is positioned in the open position. In the illustrated embodiment, the fusible link 157 is retainably connected to the body 150 and the pivot arm 255 to limit rotational movement of the drive member 210 about the pivot axis PA, such that the valve plate 152 is positioned in the open position.

[0098] The fusible link 157 restricts the valve plate 152 from moving from the open position to the closed position via the interconnection between the fusible link 157 and the bias system 223. The fusible link 157 is configured to melt at a predetermined temperature, thereby disengaging the interconnection between the fusible link 157 and the bias system 223 and the body 150, and thereby allowing the bias system 223 to move the valve plate 152 to the closed position.

[0099] In the illustrated embodiment, the fusible link 157 of the damper includes a first link end 274 and a second link end 275. The first link end 274 of the fusible link 157 is mounted to the link anchor 194 via a fastener 267, and the second link end 275 of the fusible link 157 is mounted to the distal end 263 of the pivot arm 255 via a second fastener 267. (Reference) Figure 9 A pair of washers 277 can be associated with each link fastener 267 to help allow each end 274, 275 to rotate relative to the component to which it is connected. The washers 277 can be arranged on both sides of the link 157 such that the link is positioned between the pair of washers 277.

[0100] refer to Figure 9 and 20 The connector 159 includes a mating threaded surface 280 configured to threadedly engage at least one of the threaded surfaces 178 of the first and second ends 171, 172 of the body 150, such that the connector 159 is substantially aligned with the body 150 along the longitudinal axis LA of the body. (Reference) Figure 7 In one embodiment, the connector 159 includes a portion of the conduit 148. In another embodiment, the conduit 148 includes a tube segment 282 that connects to the connector 159 of the damper 50. In another embodiment, the tube segment 282 may be made of a suitable plastic (e.g., PVC). In yet another embodiment, the tube segment 282 may be made of plastic instead of metal to provide cost savings and facilitate installation of the conduit 148.

[0101] The safety cabinet 30 may, in other respects, be similar to the safety cabinet shown and described in U.S. Patent 6,729,701, which is incorporated herein by reference in its entirety. For example, other components of the latching system 46, the retaining system 42, and the closing system 44 may be similar to those shown and described in U.S. Patent 6,729,701. In embodiments, the safety cabinet 30 may, in other respects, be similar to the safety cabinet shown and described in U.S. Patent 8,172,344 and / or U.S. Patent 9,630,036 and / or U.S. Patent Application Publication No. US2008 / 0106174 and / or U.S. Patent Application Publication No. US2013 / 0200767, which are incorporated herein by reference in their entirety.

[0102] All references cited in this article (including publications, patent applications and patents) are incorporated herein by reference as if each reference were individually and specifically indicated to be incorporated by reference and fully elaborated in this article.

[0103] Unless otherwise stated herein or clearly contradicted by the context, the terms “a,” “an,” and “the,” and similar references used in the context of describing this disclosure (particularly in the context of the appended claims) should be interpreted as encompassing both singular and plural forms. Unless otherwise stated herein, descriptions of numerical ranges herein are intended only as a way of abbreviating each individual numerical value falling within the range, and each individual numerical value is incorporated into this specification as if it were individually referenced herein. Unless otherwise stated herein or clearly contradicted by the context, all methods described herein can be performed in any suitable order. Unless otherwise stated, the use of any and all examples or exemplary language (e.g., “for example”) provided herein is intended only to better illustrate this disclosure and does not constitute a limitation on the scope of this disclosure. No language in the specification should be construed as indicating that any unclaimed element is essential to the practice of this disclosure.

[0104] This document describes preferred embodiments of the present disclosure, including the best modes known to the inventors for carrying out the present disclosure. Of course, variations of those preferred embodiments will become apparent to those skilled in the art upon reading the foregoing description. The inventors anticipate that those skilled in the art will be able to suitably employ such variations, and the inventors believe that the present disclosure can be practiced in ways other than those specifically described herein. Therefore, this disclosure includes all variations and equivalents of the subject matter described in the appended claims as permitted by applicable law. Moreover, unless otherwise stated herein or clearly contradicted by the context, this disclosure should cover any combination of all possible variations of the foregoing elements.

Claims

1. A safety cabinet comprising: An outer casing, the outer casing defining an interior, an opening and a vent, the opening and the vent communicating with the interior of the outer casing; A door, rotatably mounted to the housing and movable within a range of travel between an open position and a closed position, wherein when the door is in the closed position, the door is adapted to cover at least a portion of the opening in the housing; A ventilation system comprising a duct having an internal channel and a thermally actuated damper, the duct being connected to the housing such that the internal channel of the duct communicates with the vent of the housing, the thermally actuated damper comprising: A body extending along a longitudinal axis and having a first end and a second end, the first end and the second end being arranged spaced apart from each other along the longitudinal axis, the body defining an internal channel having a first opening at the first end and a second opening at the second end, the body including a portion of the conduit such that the first end of the body communicates with the vent of the housing. A valve plate is disposed within a channel of the body, such that it is interposed along the longitudinal axis between the first end and the second end of the body. The valve plate is movable between an open position and a closed position. When the valve plate is in the open position, it allows air to flow between openings in the channel of the body, and when the valve plate is in the closed position, it substantially blocks the channel of the body. A pivoting assembly includes a biasing system and a fusible link. The biasing system is mounted to the body such that it acts on a valve plate and is adapted to bias the valve plate to a closed position. The fusible link interconnects the body and the biasing system to form an interconnect therebetween, such that the valve plate is positioned in an open position. The fusible link restricts movement of the valve plate from the open position to the closed position via the interconnect between the body and the biasing system. The fusible link is configured to melt at a predetermined temperature, thereby releasing the interconnect between the biasing system and the body and thereby allowing the biasing system to move the valve plate to the closed position.

2. The safety cabinet of claim 1, wherein the pivoting assembly of the damper includes a valve support assembly mounted to the body and the valve plate, the valve support assembly being adapted to support the valve plate such that the valve plate is movable between an open position and a closed position, and the biasing system is mounted to the body and to at least one of the valve plate and the valve support assembly.

3. The safety cabinet according to claim 2, wherein both the first end and the second end of the body include threaded surfaces, and the damper further includes: A coupling member including a mating threaded surface configured to threadably engage at least one of a threaded surface at a first end and a threaded surface at a second end of the body, such that the coupling member is substantially aligned with the body along the longitudinal axis of the body, the coupling member including a portion of the conduit.

4. The safety cabinet of claim 3, wherein the conduit includes a tube segment connected to the coupling of the damper, the tube segment being made of plastic.

5. The safety cabinet of claim 2, wherein the damper's body includes an outer surface and an inner surface, the inner surface being generally cylindrical and defining a channel therein, the outer surface being radially externally circumscribed relative to the inner surface, the body defining a transverse bore extending radially from the outer surface to the inner surface, and wherein the biasing system includes a drive member and a spring, the drive member defining a pivot axis, the drive member extending through the transverse bore of the body, the drive member being coupled to the valve plate such that rotational movement of the drive member about the pivot axis correspondingly rotates the valve plate, the fusible link being retainably connected to the drive member to restrict rotational movement of the drive member about the pivot axis such that the valve plate is positioned in the open position, the spring being mounted to the body and the drive member such that the spring applies a spring force to the drive member, the spring force being configured to rotate the drive member about the pivot axis in a closing direction to move the valve plate from the open position to the closed position when the fusible link melts.

6. The safety cabinet of claim 5, wherein the drive member of the damper includes a drive sleeve and a pivot arm, the drive sleeve having an inner end and an outer end, the inner end of the drive sleeve being connected to the valve plate, the outer end of the drive sleeve being arranged externally relative to the outer surface of the body, the pivot arm being mounted to the drive sleeve adjacent to the outer end of the drive sleeve such that the distal end of the pivot arm protrudes from the drive sleeve, and the spring being connected to the pivot arm.

7. The safety cabinet of claim 6, wherein the fusible link of the damper includes a first link end and a second link end, and wherein the body includes a link anchor protruding outward from the body, the first link end of the fusible link is mounted to the link anchor, and the second link end of the fusible link is mounted to the distal end of the pivot arm.

8. The safety cabinet of claim 2, wherein the damper's body includes an outer surface and an inner surface, the inner surface being generally cylindrical and defining a channel therein, the outer surface being radially externally circumscribed relative to the inner surface, the body defining a pair of transverse bores opposite to each other and each transverse bore extending radially from the outer surface to the inner surface, and wherein the valve support assembly includes a pair of trunnion members connected to the valve plate such that the trunnion members extend from the valve plate into the transverse bores of the body, the trunnion members and the valve plate being pivotable relative to the body about the pivot axis.

9. The safety cabinet of claim 8, wherein the valve support assembly of the damper includes a pair of bushings, each bushing being disposed at least partially within the transverse bore of the body, and the trunnion members extending from the valve plate into the bushings.

10. The safety cabinet of claim 9, wherein the trunnion members of the damper each include a distal end extending through the bushing, such that the distal end of each trunnion member is arranged externally relative to the corresponding bushing, such that the distal end of the trunnion member provides a capture connection between the valve plate and the body.

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