Method to Make a Reusable Liquid Metal Castable Drill Bushing

Abstract

The method of locating hole features so that old components can be replaced with new components and still match fit with the airframe includes the steps of adhering a bushing assembly into a fixture plate, rigidly attaching the fixture plate with the bushing assembly to the old component, heating the liquid metal above the liquid metal melting temperature such that the cylindrical drill bushing can move within the assembly, inserting an alignment pin within the cylindrical drill bushing such that the alignment pin is also inserted into an existing hole in the old component and the airframe, allowing the liquid metal to re-solidify; removing the alignment pin from the old component, replacing the old component with the new component, and using the re-solidified assembly as a drill guide for replacing holes in the new component.

Claims

1. A method of locating hole features so that old components can be replaced with new components, the method comprising: adhering or building a bushing assembly into a fixture plate, the bushing assembly comprising: a cylindrical sleeve having an inner diameter; a cylindrical drill bushing having an outer diameter, the cylindrical drill bushing disposed within the cylindrical sleeve; a liquid metal disposed between the inner diameter of the cylindrical sleeve and the outer diameter of the cylindrical drill bushing; a seal disposed on the cylindrical sleeve, the cylindrical drill bushing, and the liquid metal such that the seal retains the liquid metal between the outer diameter of the cylindrical drill bushing and the inner diameter of the cylindrical sleeve; rigidly attaching the fixture plate with the bushing assembly to an old component; heating the liquid metal above the liquid metal melting temperature such that the cylindrical drill bushing can move within the bushing assembly; inserting an alignment pin within the cylindrical drill bushing such that the alignment pin is also inserted into an existing hole in the old component; allowing the liquid metal to re-solidify; and, using the assembly as a drill guide for replacing holes in a new work component.

Description

DRAWINGS

[0012] These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims, and accompanying drawings wherein:

[0013] FIG. 1A is a perspective view of the drill bushing assembly;

[0014] FIG. 1B is a side view of the drill bushing assembly;

[0015] FIG. 1C is a cross-sectional view of the drill bushing assembly;

[0016] FIG. 2 is perspective view of the drill bushing assembly in use; and

[0017] FIG. 3 is an exploded perspective view of the drill bushing assembly in use.

DESCRIPTION

[0018] The preferred embodiments of the present invention are illustrated by way of example below and as shown in FIGS. 1A-C, 2 and 3. As shown in FIGS. 1A, 1B, and 1C, the reusable liquid metal castable drill bushing assembly 10 for use in a fixture plate 40 includes a cylindrical sleeve 100 having an inner diameter 105, a cylindrical drill bushing 300 having an outer diameter 305, a liquid metal 400 disposed between the outer diameter 305 of the cylindrical drill bushing 300 and the inner diameter 105 of the cylindrical sleeve 100, a seal 500 disposed on the cylindrical sleeve 100, the cylindrical drill bushing 300, and the liquid metal 400 such that the seal 500 retains the liquid metal 400 between the outer diameter 305 of the cylindrical drill bushing 300 and the inner diameter 105 of the cylindrical sleeve 100.

[0019] In the description of the present invention, the invention will be discussed in a military aircraft environment; however, this invention can be utilized for any type of application that requires locating hole features.

[0020] In the preferred embodiment, the liquid metal 400 is a fusible alloy of bismuth, indium, and tin. It may be Field's metal, also known as Field's alloy, which is a fusible alloy that becomes liquid at approximately 62 C. (144 F.). It is a eutectic alloy of bismuth, indium, and tin. Alternatively, any material that can change from liquid to solid phase based on an exterior input may be utilized, such as, but without limitation, magneto resistive fluid.

[0021] In one of the embodiments of the invention, the cylindrical drill bushing 300 may be manufactured from existing potted drill bushings, while the cylindrical sleeve 100 may be the inner diameters of the cylindrical holes in the fixture plate 40 (or potting fixture) as manufactured from a machinable phenolic plate such as Garolite. The seal 500 may be a rubber seal, or any other material that is practicable in the design to allow maximum flexibility for positional and angular movement of cylindrical drill bushing 300 within the cylindrical sleeve 100 while maintaining a reliable seal.

[0022] In the preferred embodiment, there are two seals 500, a top seal 505 corresponding to the top 310 of the cylindrical drill bushing 300 and a bottom seal 510 corresponding to the bottom 320 of the cylindrical drill bushing 300. The top seal 505 and the bottom seal 510 may be formed to the cylindrical drill bushing 300 by over-molding and may be mechanically clamped or bonded to the cylindrical sleeve 100 such that the liquid metal 400 is retained between the cylindrical drill bushing 300 and the cylindrical sleeve 100.

[0023] As shown in FIGS. 2 and 3, the method of locating hole features so that old components 20 (which are attached to the airframe 30) can be replaced with new components (not shown) and still match fit with the airframe 30 (or any other frame or structure) includes the steps of adhering a bushing assembly (specifically the reusable liquid metal castable drill bushing assembly 10 described above) into a fixture plate 40, rigidly attaching the fixture plate 40 with the bushing assembly 10 to the old component (or work piece) 20, heating the liquid metal 400 above the liquid metal melting temperature such that the cylindrical drill bushing 300 can freely move within the assembly 10, inserting an alignment pin 60 within the cylindrical drill bushing 300 such that the alignment pin 60 is also inserted into an existing hole in the old component 20 and the airframe 30, allowing the liquid metal 400 to cool and re-solidify; removing the alignment pin 60 from the old component 20, replacing the old component 20 with the new component, and using the re-solidified assembly as a drill guide for replacing holes in the new component.

[0024] The bushing assembly 10 may be adhered to the fixture plate 40 using cyanoacrylate glue, or any fastener practicable. In an alternate embodiment, the bushing assembly is disposed within the potting fixture with the potting fixture serving as the cylindrical sleeve 100.

[0025] When introducing elements of the present invention or the preferred embodiment(s) thereof, the articles a, an, the, and said are intended to mean there are one or more of the elements. The terms comprising, including, and having are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[0026] Although the present invention has been described in considerable detail with reference to certain preferred embodiments thereof, other embodiments are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred embodiment(s) contained herein.