Patent Application
20080012325
A representative laser block assembly 10 which can be processed using the below described fill tube/flange assembly is shown in
In forming a ring laser gyroscope from laser block assembly 10, electrodes 30, 32, and 34 are connected to a source of electrical potential (not shown), with excitation electrode 30 being connected to the negative terminal of the source of electrical potential (to function as a cathode) and excitation electrodes 32 and 34 being connected to the positive terminal of the source of electrical potential (to act as anodes). An electrical potential is placed across the cathode 30 and the anodes 32 and 34 through the lasing gas, which electrically charges the lasing gas to generate a pair of counter-rotating lasers. A sensor array (not shown) is also added in forming a ring laser gyroscope from laser block assembly 10 to measure the angular rate experienced by the laser block assembly 10 as a function of the deflection of the lasers.
To ensure the proper operation of a ring laser gyroscope that includes laser block assembly 10, the laser block assembly 10 undergoes a series of processing steps. For example, laser block 14 is typically formed from a dielectric material, such as glass or glass-ceramic, having a relatively low coefficient of thermal expansion. It is typically necessary to cleanse the laser block 14 of contaminants or otherwise process the laser block assembly 10 prior to filling closed loop path 16 with a lasing gas. Such processing steps often include the use of a variety of processing fluids, including gases and or liquids, applied under a variety of atmospheric conditions, including full or partial vacuum.
Typically, in performing the various processing steps on a laser block assembly, only a single laser block assembly 10 is processed at a time on a station of a processing tool. That is, an individual laser block assembly is mounted to an individual station typically utilizing a fill tube welded to a flange assembly to interface laser block assembly 10 to the station. During such processing, a number of sequential processing steps are performed on the laser block assembly while interfaced (mounted) to the fill tube and flange. After the desired processing steps are carried out, the laser block assembly is removed from the processing station and the fill tube is consumed in the removal process. The flange may be removed from the remaining portion of the fill tube and reattached to a new fill tube. However, such an approach is inefficient, however, as the flange has to be manually removed from the old fill tube and manually reattached to the new fill tube. These processing costs are not the only drawback. The flange can be reattached to new fill tube only a limited number of times, for example, four times. Since a flange is essentially consumed each time a small number of laser block assemblies 10 are processed, the costs of components and construction and reconstruction of multiple piece fill tube and flange assemblies has to be incorporated into the cost of the ring laser gyroscope.
During the processing of laser block assemblies, fluid port 60 is engaged, for example, in a compression type interface with the processing station. To provide a good sealing arrangement with the processing station, fluid port 60 is typically fabricated from, for example, a stainless steel, which is capable of utilization in a compression type interface. The remainder of elongated tube 52, including laser block interfacing portion 58, is fabricated from an iron-nickel alloy which is capable of forming a cold welded seal. For example, once the laser block is filled with the lasing gas, a portion of elongated tube 52 is “pinched off”, leaving the laser block engaging portion 58 and a portion of elongated tube 52 to form a seal which causes the lasing gas to be retained within the lasing block due to the cold welded seal.
As described above, fluid port 60 is attached to, typically by welding, to second end 56 of elongated tube 52, and includes a sealing mechanism that is adapted to be mated to a processing tool to provide a flow path into elongated tube 52. One preferred sealing mechanism includes a knife edge flange seal 70 within fluid port 60 that engages an annular copper gasket (not shown) that surrounds a recessed area 72 of fluid port 60. The copper gasket engages and seals with a mating surface of the processing tool to provide a fluid-tight seal between tube and flange assembly 50 and the processing tool. This fluid-tight seal permits a vacuum to be drawn if desired for a particular processing application, and ensures that processing fluid is dispensed into fill tube and flange assembly 50 without loss to the surrounding environment of the processing tool.
Tube and flange assembly 50 is functional for the processing of laser block assemblies 10. However, as fluid port 60 is welded to elongated tube 52, and a portion of elongated tube 52 is pinched off during the cold weld sealing process, for example at 80, a particular welded fluid port 60 and elongated tube combination is usable only once.
Both tubes 104 and 110 are configured with second ends 130 and 132 respectively that are configured for utilization with components of compression interface 120. For example, in the illustrated embodiment, compression interface 120 includes a male split-nut 140 which engages second end 132 of fill tube 114, a female nut 142 which engages second end 130 of flange assembly 106, components of a torque eliminator 144 and 146, and a seal 148. By using compression interface 120 to join second ends 130 and 132 of flange assembly 106 and fill tube 114, flange assembly 106 can be utilized in the processing of multiple laser block assemblies, which is an increase in efficiency and a decrease in costs from the fill tube flange assembly 50 (shown in
Flange assembly 106 is described herein as known ring laser gyroscope processing stations are configured to interface with the flange (herein, fluid port 102). In an alternative embodiment, the processing station for the ring laser gyroscope blocks is configured such that second end 132 of fill tube 114 is attachable thereto, for example, using a compression type interface, and eliminating flange assembly 106.
As compression type junctions are known to twist the tubes that are being joined, optional torque eliminators 144 and 146 are configured to engage lateral formations 170 on respective ends 130 and 132 of flange assembly 106 and fill tube 114 to reduce and possibly prevent twisting and deformation of flange assembly 106 and fill tube 114 which may be detrimental to sealing and reuse of flange assembly 106.
Fill tube and flange assembly 50 (shown in
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.
