A safety gate for confined spaces having doors or other movable access barriers. The safety gates provide a physical barrier which inhibits entry into the confined space when the safety gate is in a closed position and prevents the door or access barrier from closing and entrapping a person when the safety gate is in a safety position.
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 62/808,291, filed Feb. 20, 2019, which is hereby incorporated by reference.
The closure of doors, hatch covers or shields through inadvertence, gravity, by a spring biased door swinging closed, or by mechanical failures of actuated door controls, which provide access to confined spaces such as small and bulk autoclaves, rack and cage wash equipment, high pressure chambers, vacuum chambers, bulk sterilizers, vaults, freezers, machines, pens, garages, cold storage rooms, and similar types of equipment and other potentially hazardous confined spaces, has resulted in serious injuries and fatalities. For example, in a 2012 accident a technician was entrapped in the confined space of the bulk sterilizer when another worker closed the chamber door and started the normal operation cycle of the sterilizer under the mistaken belief that all persons had egressed the confined space. The technician did not survive. In another fatal accident in 2005, a worker was locked in a commercial size, high-temperature, rack wash machine, unbeknownst to his co-workers.
Therefore, there is a need to improve the safety of confined spaces to minimize the risk of serious injury or worse to technicians and operators.
Various embodiments provide movable safety gates to the access openings of confined spaces which present a danger to human occupants who may become entrapped within the confined space during a dangerous condition, such as an extreme temperature, a vacuum, high pressure steam and/or a toxic or hazardous gas or chemical. The various embodiments enhance the safety of confined spaces which have access openings and a selectively openable and closable access barrier, such as a door, hatch cover and the like which are normally maintained in a closed position during operation of the equipment, but which can be opened to allow the ingress and egress of an adult human. The disclosed safety gates are movable from a closed position where the safety gate forms a physical barrier which inhibits entry into the confined space to a safety position where the safety gate prevents the door or form of access barrier from closing and entrapping a person within the confined space.
A safety system comprises a confined space and a safety gate which provides a protective shield or barrier that inhibits entry into the confined space that may be hazardous to a human occupant when the safety gate is in closed position. When the safety gate is swung aside to the “safety” position to permit a person to pass through an access opening, the safety gate itself blocks, stops or otherwise prevents a door, cover or shield (door) from fully shutting. When the technician or operator leaves the confined space, she can return the safety gate to the closed position and fully shut the door. Thus, the safety gate reduces the risk that a person will inadvertently become trapped within a dangerous confined space by the door, cover, shield or the like.
As used herein, the term “confined space” is used to indicate a space that:
(1) Is large enough and so configured that an employee can bodily enter and perform assigned work; and
(2) Has limited or restricted means for entry or exit (for example, tanks, vessels, silos, storage bins, hoppers, vaults, and pits are spaces that may have limited means of entry); and
(3) Is not designed for continuous employee occupancy.” As used herein, the term “confined space” refers to the space when a normal barrier to entry, such as a door or manhole cover, are in the close position. As used herein, “confined spaces” include, but are not limited to, sterilization chambers, wash equipment, tanks, vessels, silos, storage bins, hoppers, vaults, pits, manholes, tunnels, equipment housings, ductwork, pipelines, etc. The focus of the safety systems described herein is to enhance safety in spaces which are inhospitable to human health and well-being during operating conditions. The subject confined spaces are not necessarily air tight.
One embodiment of a disclosed safety system comprises a safety gate configured so that when the safety gate is in the closed position the safety gate remains in closed position, forming a physical boundary to the confined space. In other words, until a person purposely causes the opening of the safety gate, the safety gate will remain in the closed position blocking human ingress into the confined space. When the safety gate is even partially swung away from the closed position, the safety gate is biased such that the safety gate will swing fully to the “safety position” and will remain in the safety position, preferably resting on the door jamb. In the safety position, the safety gate prevents the door (or other barrier) to the confined space from fully closing, thus preventing complete entrapment of a person within the confined space.
When the safety gate is mounted inside the confined space relative to the door, the safety gate is preferably configured to prevent the blocking arm of the safety gate from swinging into the confined space from the closed position. Alternatively, if the door is designed to be opened by pushing the door into the confined space, when the safety gate is in the safety position, the safety gate will block the door jamb and prevent the door from swinging fully outwardly to close. In either design, once the safety gate is even partially moved from the closed position, the safety gate is biased, e.g. by a spring or cam hinge (gravity), to remain in the safety position to block the door, cover or shield from inadvertently closing and entrapping a person.
The safety gate is preferably mounted inside the confined space, on or near the door jamb, behind the door of the confined space. In such embodiments, the safety gate is designed to be swung outwardly after the door is opened, in order to allow a person to pass into the confined space. However, when it is necessary to mount the safety gate on the outside of the confined space, e.g. in front of the door, then the safety gate is designed and mounted to swing from a closed position blocking access to the confined space to a safety position in the confined space when the door is opened inwardly. In the safety position, the safety gate is positioned to prevent the door from fully closing when the safety gate is in the opened position. After all persons have egressed the confined space, the safety gate is returned to the closed position and the door is permitted to be fully closed.
The figures illustrate examples of the safety systems including the disclosed safety gates.
The upper inclined surface 223 of lower hinge section 221 and lower inclined surface 226 of upper hinge section 225 are best shown in the side view of
All of the disclosed safety gates are also preferably provided with signage, markings, coloration or other indicators as desired.
The hinge and/or safety gates of other embodiments have built-in switches. The hinge or safety gate positions are used to change the state of a switch. For example, the hinge or safety gate changes the state of a photo switch or other presence detecting devices (e.g. PIR, Lidar, Radar, etc.), that are located outside of the entrance (doorway), thus signaling the controls for the activity in the confined space.
Alternatively, a switch can be opened or closed by physical contact of the safety gate with a switch.
Another embodiment comprises operating equipment comprising a structure defining a confined space large enough to contain a human adult and comprising at least a first access opening which is large enough for human ingress into and egress from said confined space; a supply of at least one condition to the confined space for performing an operation, wherein said at least one condition would present an imminent danger to the survivability of a human adult present within said confined space during said operation; a selectively openable and closable access barrier which is selectively movable from a closed position to an open position, said access barrier openable to an open position which permits an adult human ingress to and egress from said confined space through said first access opening and closable to a closed position which does not permit ingress and egress through said first access opening; and a safety gate movable from a closed position, wherein the gate extends across said first access opening and obstructs the ingress of an adult human into said confined space through said first access opening, to a safety position which does not permit said access barrier to be positioned in said closed position. In this version the operating equipment may create a condition comprising at least one of an extreme temperature, a vacuum, high pressure, steam and or a toxic chemical.
In another version, the operating equipment is one of an autoclave, a sterilizer, and wash equipment.
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Number | Date | Country | |
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20200263491 A1 | Aug 2020 | US |
Number | Date | Country | |
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62808291 | Feb 2019 | US |