Patent Abstract:
A fluid connection for a container and a method of making the connection isescribed. The connection is provided subsequent to the manufacture of the container according to the teachings of the present invention.

Full Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to fluid connections. More particularly, this invention relates to fluid connections for hydraulic or similar cylindrical assemblies having a thin metal liner reinforced by a layer of resin impregnated filament. 
     2. Description of the Prior Art 
     Hydraulic cylinder assemblies such as those utilized for actuating aircraft controls are generally constructed of a relatively thin metal liner reinforced to withstand normal operational pressure. Resin impregnated filament composites are often used as the reinforcing material of choice because of the resulting low weight, cost, and resistance to malfunction if the device is penetrated by a projectile. 
     Existing assemblies utilize integral, side-mounted tubes or connections for conducting hydraulic fluid. These tubes are welded to the exterior of the metal liner prior to application of the reinforcing material. Alternately, concentric tubes or connections extending axially from either end of a cylindrical assembly may be used. 
     The first arrangement complicates emplacement of the reinforcing wrapping due to the need to pass filaments around or under the installed tubes. The second arrangement requires seals and element internally of the liner thereby increasing the cost of manufacture and resulting weight of the finished unit. The second arrangement is also impractical for use with a cylinder assembly having a plurality of internal coaxially related pistons. 
     SUMMARY OF THE INVENTION 
     In accordance with the broader aspects of this invention, there is provided a connection comprising a tubular fluid source and a beveled interior end section communicating with the assembly interior. The cylinder assembly preferably is of composite construction having a thin metal liner with one or more bosses formed on the liner surface. The liner is reinforced by a layer or layers of resin impregnated filament. A channel or passageway is drilled through the exterior filament layer so as to pass through the liner and at least one boss providing a conduit into the cylinder cavity. The port thus formed has an internal beveled surface which diverges radially outwardly of the liner. The tubular insert is positioned in the channel until the beveled interior end section abutts the internal beveled surface of the boss. A resilient O-ring or similar seal is provided at the juncture of the boss beveled surface and the beveled interior end section of the tubular insert to provide a fluid tight seal. 
     OBJECTS OF THE INVENTION 
     It is, therefore, a primary object of the present invention to provide articles such as pressure vessels, fluid actuated cylindrical assemblies and the like having fluid connections provided subsequent to the manufacture of the device. 
     It is a further object of the invention to provide a method for providing a fluid connection in a molded or cast container having a reinforced metallic inner liner by cutting or drilling through the outer structural filamentary material and the metallic inner layer boss surface to form a connection conduit. 
     Yet another object of the invention is to provide improved articles such as pressure vessels, fluid actuated cylindrical assemblies and the like, and improvements in the manufacture thereof. 
     These and other objects of the invention will become more readily apparent from the following specification when read in light of the drawing. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a partial cross-sectional view of one embodiment of the invention wherein a connection is provided in a fluid actuated assembly. 
     FIG. 2 is an enlarged cross-sectional view of the connection in greater detail. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring concurrently to FIGS. 1 and 2, a hydraulic cylinder assembly 10 is disclosed having a thin metal inner liner 12 reinforced with an outer layer 14 of resin impregnated filament composite material. The liner is provided with a central bulkhead 16, a pair of opposing heads 18 and 20 retained on liner 12 by filament layer 14, and four bosses or boss surfaces, designated at 22. A fluid driven piston rod 24 extends medially through assembly 10 and central bulkhead 16. A pair of pistons 26 and 28 are attached to rod 24 and positioned in chambers 30 and 32 defined by central bulkhead 16. Conventional fluid seals 34 are provided in head 20 and bulkhead 16. Four tubular fluid connections 36 including a threaded exterior portion 38 and a beveled interior end section 40 are provided for introducing fluid into assembly 10. Each connection is located above and in vertical alignment with each boss surface 22. 
     The cylinder assembly is initially constructed without fluid connections. The liner, including the bulkhead, opposing heads, piston rod, and boss surfaces, is first covered with the resin impregnated filament composite material layer. Upon curing the outer layer, a channel 42 is drilled through the layer of filament material and passing through each boss surface in the metallic liner so as to form an internal beveled boss surface 44 diverging radially outwardly of the liner. It is evident from FIG. 1 that channel 42 has a first portion through layer 14 and a second portion through the corresponding boss 22 of layer 12 and it is evident that the second portion is cut in the same operation as the first portion as an extension thereof. Next, a resilient seal 46 is inserted into channel 42 and retained on beveled boss surface 44. Finally, a fluid connection 36 is inserted into each channel 42 until the beveled interior end section 40 is in abutting engagement in a direction lengthwise of the channel with the resilient seal, as best shown in FIG 2. The connection may be sealed in place within the channel by any suitable means such as by gluing or utilizing a compatable resin. 
     While the preparation of only one connection has been described in detail, it is to be understood that multiple connections may be provided utilizing the disclosed method. 
     Obviously, many modifications and variations of the invention are possible without departing from the scope of the appended claims.

Technology Classification (CPC): 5