This invention generally relates to fire suppression systems and more particularly, to methods and apparatus for maintaining fire suppression systems.
Fire suppression systems that are installed on mobile platforms present a unique problem when servicing is required. Service may include, but not be limited to, recharge of agents, pressurizing cylinders, and hydro-testing of tanks. At least some known systems require maintenance personnel to climb onto the vehicle to conduct such service, using, for example, ladders, fold-down steps, both of which may be integral to the vehicle, or the use of external devices to allow access to the roof of the vehicle. Such approaches put personnel at risk of falling from vehicles, lifting heavy objects under elevated conditions, and otherwise placing personnel in awkward positions on unstable platforms. For example, personnel are required to climb on-board the platform to conduct recharge and refilling operations or other scheduled maintenance items.
Solutions to such problems have included the use of personnel protective equipment, most notably safety harnesses and the use of grab rails to provide support. In general, passive protection is applied to protect personnel while the fire suppression system is maintained in a fixed position. However, the standard practice has not eliminated the hazards associated with servicing on-board systems at elevation, but rather attempt to insure personnel are protected from injury using protective equipment.
In one embodiment, a lift system for translating equipment mounted on a vehicle between an operational position and a servicing position is provided. The lift system includes a support frame fixedly mounted to the vehicle, a transport member slidably coupled to the support frame, and a lift platform coupled to the transport member wherein the lift platform is configured to support the equipment in the operational position and in the servicing position.
In another embodiment, a method for gaining access to equipment that is positioned remotely during operation is provided. The method includes operating the equipment in an operational position on a vehicle, moving the equipment to a servicing position on the vehicle to perform maintenance on the equipment wherein the servicing position provides greater access to the equipment than the operational position.
In yet another embodiment, a vehicle for transporting equipment includes an enclosure housing the equipment, a support frame fixedly mounted to the vehicle, a transport member slidably coupled to the support frame, and a lift platform coupled to the transport member wherein the lift platform is configured to support the equipment in an operational position and a servicing position.
Vehicle 100 also includes a lift assembly 120 that substantially reduces the need for personnel to climb on-board vehicle 100 to conduct maintenance activities. In an operational condition, the fire-suppression equipment requiring service is typically located in a restricted access location, such that it is protected from the environment during transit and operation. In the exemplary embodiment, vehicle 100 utilizes lift assembly 120 to position the fire-suppression equipment requiring service in a position outside of outer perimeter of enclosure 108 and/or outside an outer perimeter of vehicle 100. Servicing can then be conducted from a stationary ground level servicing position. Such a servicing position is illustrated in
Lift assembly 120 is integrated into frame 104 and enclosure 108 of vehicle 100. In the exemplary embodiment, lift assembly 120 incorporates an outer steel channel 122 and inner steel tube 124 positioned along each side of vehicle 100. Each of outer steel channel 122 and an inner steel tube 124 are lined with, for example, a relatively high density and ultra high molecular weight polypropylene to reduce frictional forces between outer steel channel 122 and an inner steel tube 124 during operation. The lined surfaces of outer channel 122 and inner tube 124 are in contact with each other throughout the operation of the lift and provide a low friction surface without additional moving parts, such as bearings or rollers. Inner tube 124 travels a distance of approximately 36 inches (914.4 mm) along the two tracks formed by outer steel channel 122 and an inner steel tube 124, utilizing a drive unit 126. In the exemplary embodiment, drive unit 126 includes a single hydraulic ram including a cylinder and a piston that is hydraulically and/or pneumatically actuated. In an alternative embodiment, drive unit 126 includes a lead screw assembly. Lift assembly 120 is powered by a 12 volt DC hydraulic pump 128 and is operated by a bi-directional toggle switch 130 to raise or lower lift assembly 120. Tank 111 is permanently mounted to a lift platform 132 for operational efficiency. Tank 111 is lowered to a servicing position at ground level for servicing and raised to an operational position on-board vehicle 100. In the operational position, a locking mechanism 134 substantially prevents ram 126 from moving. Locking mechanism 134 is interlocked with an electrical system (not shown) on-board vehicle 100 and may be engaged manually or automatically. The locking mechanism 134 engages when the lift assembly 120 is in the fully retracted position, and operates to prevent lift assembly 120 from being lowered in the event that a rear enclosure door 136 is not fully open or the vehicle is not secure such that movement of the vehicle is substantially blocked.
During operation of vehicle 100, tank 111 is housed in enclosure 108 with door 136 extended in a closed position, for example, during travel to the location of a fire or other emergency. After arrival at the emergency location, door 136 may be retracted to an open position exposing limited access to tank 111 to support operation of a fire suppression activity, for example. Such limited access may be desirable for monitoring tank 111 or operating valves and switches coupled to tank 111.
During servicing, with vehicle 100 secured or being disabled for movement, tank 111 is extended horizontally from the confines of enclosure 108 using lift assembly 120. Lift assembly 120 is interlocked using switches coupled to 12 volt DC hydraulic pump 128 and toggle switch 130 to prevent operation of lift assembly 120 if door 136 is not fully retracted in the open position or if vehicle 100 is not fully secure. Additional interlocks may be employed depending on the particular configuration of vehicle 100 and the equipment. Tank 111 is extended by operating switch 130, which aligns hydraulic valves to supply fluid to an extend side of ram 126. Lift assembly 120 may be configured to be stopped in an intermediate position between fully retracted and fully extended positions. When the lift assembly is fully retracted, it may be locked in position using locking mechanism 134.
The above-described means for removing the hazards associated with servicing such equipment as fire suppression systems at elevation is a cost-effective and highly reliable system. The various embodiments of the present invention allows, for example, the fire suppression system to be relocated at ground level or in a position such that it is no longer necessary for personnel to either climb onto a vehicle or work in an isolated space. Accordingly, the lift system facilitates operation of for example, fire-fighting or rescue equipment in a cost-effective and reliable manner.
While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims.
This application is entitled to the benefit of, and claims priority to, provisional U.S. Patent Application Ser. No. 60/728,718, filed Oct. 20, 2005 and entitled “Hydraulic Assist For The Servicing Of On-Board Fire Suppression Systems,” which is hereby incorporated by reference in its entirety.
Number | Date | Country | |
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60728718 | Oct 2005 | US |