Patent Application
20090108549
The present patent application is one of a set of commonly owned applications filed on the same day as the present application, sharing some inventors in common, and relating to airplane ground support equipment and carts. The other applications in this set, listed here, are hereby incorporated by reference into the present application: “A Multi-Voltage Power Supply for a Universal Airplane Ground Support Equipment Cart,” James W. Mann, III and David Wayne Leadingham (Ser. No. ______, Atty. Doc. No. 50-002 ITW 21608U); “An Adjustable Cooling System for Airplane Electronics,” Jeffrey E. Montminy and Steven E. Bivens (Ser. No. ______, Atty. Doc. No. 50-003 ITW 21585U); “A System of Fasteners for Attaching Panels onto Modules that are to be Installed on an Airplane Ground Support Equipment Cart,” Jeffrey E. Montminy, Brian A. Teeters, and Kyta Insixiengmay (Ser. No. ______, Atty. Doc. No. 50-005 ITW 21587U); “Airplane Ground Support Equipment Cart Having Extractable Modules and a Generator Module that is Separable from Power and Air Conditioning Modules,” James W. Mann, III and Jeffrey E. Montminy (Ser. No. ______, Atty. Doc. No. 50-006 ITW 21586U); “An Adjustable Air Conditioning Control System for a Universal Airplane Ground Support Equipment Cart,” James W. Mann, III, Jeffrey E. Montminy, Benjamin E. Newell, and Ty A. Newell (Ser. No. ______, Atty. Doc. No. 50-007 ITW 21606U); “A Compact, Modularized Air Conditioning System that can be Mounted Upon an Airplane Ground Support Equipment Cart,” Jeffrey E. Montminy, Kyta Insixiengmay, James W. Mann, III, Benjamin E. Newell, and Ty A. Newell (Ser. No. ______, Atty. Doc. No. 50-008 ITW 21583U); and “Maintenance and Control System for Ground Support Equipment,” James W. Mann, III, Jeffrey E. Montminy, Steven E. Bivens, and David Wayne Leadingham (Ser. No. ______, Atty. Doc. No. 50-009 ITW 21605U).
1. Field of the Invention
The present invention relates generally to the field of the design of sheet metal frames for covered enclosures, and more particularly to the design of frames and panels for air conditioning, power generation, and power conversion equipment modules that are to be installed on a universal airplane ground support equipment cart.
2. Description of the Related Art
When an airplane is on the ground with its engines shut down, the airplane is typically unable to provide power for its electrical systems and chilled air for its air conditioning systems; and some airplanes are also unable to provide liquid coolant for some critical electronic (or “avionic”) components. It is customary to connect such a grounded airplane to an airplane ground support equipment system. Such a system may have its components mounted upon a mobile equipment cart that is called an airplane ground support equipment cart and that may be parked, placed or mounted conveniently close to an airplane requiring ground support. Such a cart typically contains an air conditioner that can provide conditioned and cooled air to an airplane plus an electrical power converter that can transform power drawn from the local power grid into power of the proper voltage (AC or DC) and frequency required by the airplane. Such an airplane ground support equipment cart may also contain a diesel engine connected to an electrical generator that enables the cart to provide both air conditioning and also electrical power conversion for an airplane without any connection to the local power grid. And if an airplane requires a source of cooled liquid for its electronics, some carts may also include a source of liquid coolant.
In the past, particularly with regard to military airplanes, such ground support equipment carts have been custom designed to meet the specialized needs of a single particular type or class of airplane. Hence, a cart designed to support the specific requirements and needs of a first type or class of airplane cannot be used to support the differing specific requirements and needs of other types or classes of airplanes. Different airplanes typically may require different pressures and volumes of cooled air, different amounts of electrical power, different electrical voltage levels, and different electrical frequencies (or direct current). And different airplanes typically may require differing pressures and volumes of cooled liquid for use in cooling onboard electronics. Accordingly, every airport must be supplied with as many different types of ground support equipment carts as there are different types or classes of airplanes that may land and take off at each airport or military base. Problems arise when more airplanes of a particular type arrive at a specific location than there are ground support equipment carts suitably designed to service the needs of that particular type or class of airplane.
As an example of an airplane cart arrangement that provides air and electrical conditioning for an airplane, PCT patent application No. PCT/US2006/043312 (Intl. Pub. No. WO 2007/061622 A1 published on May 31, 2007) discloses an airplane ground support cart that has a modular design of its electrical conditioning components. This cart provides air conditioning and electrical power conversion as well as optional electrical power generation services to airplanes.
The present invention has as its goal the realization of modules of similar design, both large and small, that may be installed on such a cart, interchanged with one another, and removed for convenient servicing. Larger modules might contain air conditioning equipment or power generation equipment, while smaller modules may contain power converter equipment, such as units that can convert 3-phase 460 volt 60 Hz A.C. incoming power into 270 volts DC or 115 volts 400 Hz A.C. Other modules may contain control panels and displays and computers and other such equipment.
These modules should be strong enough so that they may be lifted and moved about without damage. They should be relatively easy to disassemble so that repairs can be carried out without great difficulty, but there should be no loose parts that could be sucked up into a jet turbine engine, causing serious damage. The module design should lend itself readily to electromagnetic shielding. They should be relatively water and weather resistant, but there should be a minimum of internal enclosed channels where moisture could collect and do serious damage. The design of these modules should scale easily up or down into large or small modules as required by the nature of the ground support equipment being housed.
An embodiment of the invention relates to a frame, panel, and fastener system for use in constructing modules that are to be installed on a ground support equipment cart. The modules have a rectangular frame that is constructed primarily by connecting together members constructed as folded sheet metal tubes substantially rectangular in cross section but, on two adjoining sides, bent perpendicularly outwards to form a first shelf perforated with fastener mounting holes, these frame members having ends that may be fastened to pairs of ends of other like frame members at perpendicular angles to form the corners of the rectangular frame and of the modules. Panels having edges bent over to form stand-offs and perforated with fastener mounting holes are sized so the stand-offs rest upon the first shelves on plural sides of the rectangular frame. Plural fasteners have first fastener parts that are attached to the shelf fastener mounting holes and second fastener parts that are attached to the panel fastener mounting holes, with the fasteners aligned to join and to detachably hold the panels upon the first shelves to form removable side panels for the modules.
The detailed description which follows is broken into three sections. Section A presents an introduction to the environment of the present invention, which relates to the design of a modularized universal airplane ground support equipment cart. Section B, which is particularly relevant to the present invention as claimed, presents a detailed mechanical description of installable and removable modules having removable cover panels which are designed for use in conjunction with such a cart. Section C presents a detailed description of the fasteners that are used to removably attach panels to the sides of the modules and which include provision that prevents them from coming loose from the panels and modules.
Airplane ground support equipment carts are wheeled, towable carts or fixed mounted (permanently or temporarily) devices that provide air conditioning, avionics equipment liquid cooling, and electrical power conversion and generation services to airplanes whose engines are shut down. These carts preferably should be conveyed by military and other airplanes to airports and military bases all over the world, so it would be convenient and an advantage to have this equipment be no larger than a standard military equipment conveyance palette. However, many such carts today do not fit one standard palette, and this reduces the numbers of ground support equipment that is available in the field. Traditionally, such ground support equipment carts are custom-designed—they provide such services to only one type or class of airplane. Hence, different carts must be provided for each different type of airplane. Also traditionally, the air conditioning components mounted on such carts are so bulky that they occupy the entire area of the cart, making it necessary to sandwich electrical power conversion and other components wherever there is room and thereby making it extremely awkward to service or replace such cart-mounted components.
The present invention is embodied in a universal airplane ground support equipment cart—universal in the sense that it is designed to service the varied needs of a variety of types and classes of airplanes, rather than just one type or class. This ground support equipment cart is also modular—its components are rectangular modules that may be easily separated or removed from the cart for service or exchange. The modules may also be used independently of the cart, and modules not needed for a particular type of airplane may be readily removed and used elsewhere, standing by themselves, in a highly flexible manner. Such a cart 10 and several of its modules—an electrical power generation module 14, an electrical power conversion module 20, and a dual air conditioning module 400 (which also provides PAO liquid cooling)—are illustrated in simplified form in
In use, the cart 10 is mounted near or drawn up to an airplane (not shown) by a suitable tractor or truck (not shown). An operator connects an air conditioning plenum or air duct 26 from the dual air conditioning module 400 to a cooled air input port (not shown) on the airplane. And if the airplane has avionics or other electronic components that require a supply of liquid coolant, then the operator also connects a pair of PAO liquid coolant conduits 28 from the air conditioning module 400 to a pair of PAO ports on the airplane. The operator then uses a suitable electrical power cable (not shown) to connect an electrical power output port or receptacle (not shown in
Next, the operator depresses a “Start” pushbutton (not shown) on the front panel of a control module 22 having a display screen 24 that then displays a main menu (not shown). If the airplane is a T-50 Golden Eagle, the operator depresses a pushbutton adjacent the label “T-50 Golden Eagle” on this menu, and then the operator depresses a pushbutton adjacent the word “Start” on a “T-50” menu that then appears. In response, all of the modules automatically reconfigure themselves as needed to service this specific type of airplane with air conditioning of the proper pressure and volume of air, with electrical power of the proper type, voltage, and frequency, and with liquid coolant (if needed). If the operator selects the wrong type of airplane, pressure and air flow measurements can detect this and shut down the system, illuminating a colored status light (not shown) to signal an error and displaying an appropriate error message on the control panel 24 to the operator. The system is halted when the operator depresses a “Stop” pushbutton on the front of the control 22.
A universal airplane ground support equipment cart is designed to provide flexible support for the needs of many different types and classes of airplanes having widely varying air conditioning and liquid cooling and electrical power support needs. The present invention can provide different pressures and volumes of cooled air and cooled liquid to different airplanes, and it can provide different types and quantities of electrical power to different airplanes. It also provides a simplified, integrated control panel where airplane service personnel can simply select the type of airplane that is to be serviced and have the various appliances on the cart automatically configured to optimize the support for that particular type of airplane.
A modular airplane ground support equipment cart is one where the different support systems provided by the cart are each confined to rugged, compact, optionally EMI shielded, rectangular modules that may be easily removed, serviced, replaced, and used stand-alone separate from the cart and its other modular components.
In the cart 10, for example, a two-stage air conditioning module 400 contains all of the air conditioning components of the cart 10, including a liquid PAO cooling system. An electrical power converter module 20 contains the power conversion components of the cart 10, including a 270 volt D.C. supply and a 115 volt 400 Hz A.C. supply; and the module 20 may be replaced or supplemented with the other module 1208 (
A power supply module 14 contains a diesel engine and a generator for producing 60 cycle, three-phase, 460 volt electrical power when the cart cannot be conveniently hooked up to a 360 to 500 volt, 50 or 60 cycle A.C., three phase supply provided by the local power grid. The power supply module 14 is confined to one end of the cart 10 and may be detached from the cart 10, as is illustrated in
Any or all of these modules 14, 20, 400, and 1208 may optionally be equipped with an internal transformer (not shown) that transforms the incoming high voltage electrical power down to 120 volts or 240 volts at 50- or 60-Hz and feeds this low voltage to standard, weather protected outlets (not shown) which can be used to provide power to hand tools and to portable lighting equipment and the like, with ground fault protection also provided to these appliances.
As is illustrated in
The cart 10 is optionally mounted upon two wheel and axle truck assemblies 18 and 19. In the space on the cart 10 between the power generation module 14 and the two-stage air conditioning module 400, one or both of the electrical power converter modules 20 and 1208 may be slid into place and attached to the cart 10, as is illustrated in
If the power generation module 14 is not required for a particular airplane support task, the module 14 and the wheel and axle truck assembly 19 beneath the module 14 may be completely detached from the rest of the cart 10, as is illustrated in
Referring now to
Viewed in cross section (See
The two inner surfaces 46 and 52 can be seen to be only about half as wide as the two outer surfaces 48 and 50. The two outer surfaces 48 and 50 and the corner 64 which joins the two outer surfaces 48 and 50 together form the outer, visible edges of the frame 40 and of the module 20. The remaining inner surfaces 46 and 52, the shelves 44 and 54, and the interior mounting brackets 42 and 56 and their respective corners 58, 60, 68, and 70 are hidden inside of the module 20 when cover plates 76 (shown in
The shelves 44 and 54 respectively join the two inner surfaces 46 and 52 at the two corners 60 and 68, as shown, and project outwards from the inner surfaces 46 and 52 parallel to the respective outer surfaces 48 and 50 to form depressed (with respect to the respective outer surfaces 48 and 50 and corners 64 of the frame 40 and module 20) shelves that are perforated with spaced-apart holes 72 to which fasteners 78 (
In one embodiment, tin plated, beryllium copper springs 74 (
Note again that the shelves 44 and 54 which support the fasteners 78 are parallel to, but depressed inwards from, the respective outer surfaces 48 and 50. This provides room such that bent-over edges 80 of removable module side cover panels 76 (
With reference again to
As shown in
With reference to
Each fastener 78 comprises four components: two components 96 and 98 mounted in the holes 72 on the shelves 44 and 54, and two components 92 and 94 mounted in the holes 82 on the removable cover panels 76.
The four components of a fastener 78 can best be seen in
With reference to all of the
The nut 98 is a female, blind-threaded standoff, part number BSOS-832-16 manufactured by Penn Engineering. The insertable hole liner 94 and bolt 92 are called captive fasteners, part number F5-832-P8 manufactured by Southco.
As shown in the figures, the nut 98 has its shaft 99 press-fitted into one of the larger holes 72 in one of the shelves 44 or 54 with the hexagonal base positioned inside of the module 20 and with the shaft 99 pointing outwards towards the removable panel 76 as shown in the figures. The nylon washer 96 has been designed such that the inside diameter of the nylon washer 96 is somewhat less than the outside diameter of the shaft 99 such that when the nylon washer 96 is pressed downwards against the outward-facing surface of one of the shelves 44 or 54, the nylon washer 96 becomes captive. The major function of the nylon washer 96 is to provide a compression stop for the panel 76 to the shelves 44 and 54 of the frame members 41. This compression stop prevents the tin-plated, beryllium copper springs 74 serving as an EMI gasket from deforming beyond its elastic limit, which would otherwise permanently flatten such a gasket and render it less effective as an EMI shield.
The insertable hole liner 94 is a cup-shaped hollow washer having a hole 91 (see
The hole 82 that passes all the way through the panel 76 is large enough to accept the hole liner's core 77. The unthreaded portion 93 of the bolt 92 is smaller in diameter than the threaded portion 95. The hole 91 in the bottom of the insertable hole liner 94 is slightly smaller in diameter than the threaded shaft 95 portion of the bolt 92 and slightly larger in diameter than the unthreaded portion 93 of the bolt 92.
Accordingly, after the insertable hole liner 94 has been press-fitted into the hole 77, the bolt 92 may be screwed through the hole 91 in the hole liner 94. The bolt 92 will then be free to move up and down, with its non-threaded shaft 93 portion free to slide back and forth within the insertable hole liner 94. However, the bolt 92 cannot fall off of the panel 76 because the threaded shaft 93 cannot fit back out of the hole 91. Likewise, the nut 98 is retained in position and kept from falling out of the frame member 41 by the nylon washer 96 which fits tightly about the internally-threaded shaft 99 and holds the nut 98 in place. Yet the two parts 92 and 98 of the fastener 78 are held in position so that when the panel 76 is placed over one side of the frame 40, a screwdriver may be used to tighten the bolt 92 into the nut 98 and to thereby fasten the panel 76 on to the frame 40 of a module 20.
It is essential that the bolt 92 and the nut 98 not be permitted to come free and accidentally become sucked into a turbojet engine, where such components can easily cause many thousands of dollars of damage. The present invention provides protection against such an accident at minimal cost without in any way making it more difficult to fasten and unfasten the fasteners 78.
While an embodiment of the invention has been disclosed, those skilled in the art will recognize that numerous modifications and changes may be made without departing from the true spirit and scope of the claims as defined by the claims annexed to and forming a par of this specification.
This application is a non provisional of provisional application Ser. No. 60/984,008 filed Oct. 31, 2007 (Atty. Docket No. 21588-P1) and provisional application Ser. No. 61/036,734 filed Mar. 14, 2008 (Atty. Docket No. 50-004 ITW 21588-P2).
| Number | Date | Country | |
|---|---|---|---|
| 60984008 | Oct 2007 | US | |
| 61036734 | Mar 2008 | US |
