Abstract:
A production apparatus includes a generally overhead track, a vertically adjustable link assembly supported from the track by one or more trolleys, a substantially horizontally oriented build beam attached to the link assembly opposite the track, a set of first and second cross beams extending from opposite sides of the build beam, and a set of third and fourth cross beams extending from opposite sides of the build beam. A set of first and second connectors are attached to the set of first and second cross beams, respectively, and are configured for attachment to a workpiece. A set of third and fourth connectors are attached to the set of third and fourth cross beams, respectively, and are configured for attachment to a workpiece. The first, second, third and fourth cross beams are each generally perpendicular to the build beam.

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
   This application claims priority from U.S. Provisional Patent Application Ser. No. 60/796,248, filed Apr. 28, 2006, for ADJUSTABLE LINK SYSTEM AND MULTIPURPOSE ENGINE SUPPORT/BUILD BEAM by Amir Kalantari, which is herein incorporated by reference in its entirety. 

   BACKGROUND OF THE INVENTION 
   The present invention relates to load supporting structures. 
   During the assembly of gas turbine engines, it is common to conduct assembly operations along an engine pack line, which resembles an assembly line. First, engine modules are built and placed on pedestals. The engine modules are then lifted into position for attachment to an engine core by cable hoists and pulleys suspended from an overhead track. As assembly operations progress, the partially assembled engine and its modules require a great deal of pick-up and moving operations with the hoists and pulleys. The pedestals can get in the way of workers. In short, these operations are time consuming and present safety issues. A key safety issue is the presence of large (about 7,257 kg or 16,000 lbs.) loads suspended in a temporary fashion from hoists and pulleys using cable, chain and hooks. This poses risks to workers around or under the engine, who can be hurt if the engine, or a part of it, falls from the hoists, pulleys, and hooks. 
   BRIEF SUMMARY OF THE INVENTION 
   A production apparatus includes a generally overhead track, a vertically adjustable link assembly supported from the track by one or more trolleys, a substantially horizontally oriented build beam attached to the link assembly opposite the track, a set of first and second cross beams extending from opposite sides of the build beam, and a set of third and fourth cross beams extending from opposite sides of the build beam. A set of first and second connectors are attached to the set of first and second cross beams, respectively, and are configured for attachment to a workpiece. A set of third and fourth connectors are attached to the set of third and fourth cross beams, respectively, and are configured for attachment to a workpiece. The first, second, third and fourth cross beams are each generally perpendicular to the build beam. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a support beam assembly according to the present invention attached to an engine core. 
       FIG. 2  is a side view of another embodiment of a support beam assembly. 
       FIG. 3  is a top view of the support beam assembly of  FIG. 2 . 
       FIG. 4  is a schematic illustration of an engine support system utilizing support beam assemblies. 
   

   DETAILED DESCRIPTION 
   The present invention relates to an engine support system and engine assembly method that utilizes a support beam assembly suspended from an overhead support assembly and pivotally attached by rigid connectors to components of an engine being assembled. Typically, the support beam assembly is suspended from an overhead track by two or more adjustable linking assemblies. The engine is supported below the support beam assembly in order to facilitate assembly operations. The support beam assembly generally remains attached to the engine throughout the assembly process. The support beam assembly includes an adjustable auxiliary beam to facilitate lifting tooling and other components relative to the engine being assembled. 
     FIG. 1  is a perspective view of a support beam assembly  10  attached to a gas turbine engine core  12  (the engine core  12  is shown in a simplified schematic manner in  FIG. 1 ) and suspended from a pair of adjustable link assemblies  14 . The support beam assembly includes a central beam  16 , a first set of cross beams  18 A and  18 B (collectively, the first set of cross beams  18 ), a second set of cross beams  20 A and  20 B (collectively, the second set of cross beams  20 ), and an auxiliary beam  22 . 
   The adjustable link assemblies  14  are located in a generally overhead position, and can be supported from an overhead track on trolleys (see  FIG. 4 ). Suitable adjustable link assemblies include those described in U.S. Pat. App. Pub. No. 2007/0261227, entitled “Adjustable Link System”, filed on even date herewith and hereby incorporated by reference in its entirety, as well as conventional commercially available screw jacks such as those available from Duff-Norton, Charlotte, N.C. The adjustable link assemblies  14  have a variable vertical length, which enables vertical adjustment suspended support beam assembly  10 . The adjustable link assemblies  14  are attached to the central beam  16  relative to the center of gravity of the engine being assembled, to better balance loads supported by the support beam assembly  10 . However, it should be noted that the center of gravity may vary slightly during the course of engine assembly, and the center of gravity will vary according to the particular type of engine being assembled. 
   The central beam (or build beam)  16  is the main structure of the assembly  10 , and is the part to which the adjustable link assemblies  14  are attached with bolts or other suitable fasteners. The central beam  16  is tubular in shape, and in the illustrated embodiment has an elongate, rectangular tube shape. Roller assemblies  24  are located at opposite ends of the central beam  16 , having rollers positioned at the interior of the central beam  16  to support the auxiliary beam  22  in a movable relationship with respect to the central beam  16 . The central beam  16 , as well as the other beams of the assembly  10 , can be made of a suitable metallic material (e.g., steel) to support desired loads with an adequate safety margin. 
   The auxiliary beam  22  is an elongate beam that extends through the interior of the central beam  16 . In the illustrated embodiment, the auxiliary beam  22  is a straight, rectangular tubular member made of a metallic material (e.g., steel), although in alternative embodiments the auxiliary beam  22  can have other shapes. The auxiliary beam  22  has a pair of parallel rails  26  disposed on each side (only one pair of rails  26  is visible in  FIG. 1 ) to engage the rollers of the roller assemblies  24  on the central beam  16 . The rails  26  can be machined into the auxiliary beam  22 . First and second hoist assemblies  27 A and  27 B, respectively, are located at opposite ends of the auxiliary beam  22 . The first and second hoist assemblies  27 A and  27 B are conventional cable or chain hoists that are capable of lifting at least about 272 kg (600 lbs.) with a suitable safety factor (e.g., with a 5× safety factor). A screw-type threaded drive shaft  28  is attached to the auxiliary beam  22 , and the drive shaft  28  is driven by a motor assembly  30  mounted on the central beam  16 . Driving the motor assembly  30  induces movement of the auxiliary beam  22  via the drive shaft, which allows horizontal, longitudinal adjustment. The motor assembly  30  can be a conventional electric motor with suitable gearing to engage the threads of the drive shaft  28 . Alternatively, a chain drive or other suitable drive system can be used in further embodiments. Control of the motor assembly  30  can be achieved using a conventional remote control (not shown), which can operate by radio frequency (RF) or other remote communication means. 
   The auxiliary beam  22  can be used to support engine modules, tooling, and other items used during the assembly of engines. The hoist assemblies  27 A and  27 A at either end of the auxiliary beam  22  can be used to raise and lower items into desired positions. Moreover, the motor assembly  30  and drive shaft  28  can be used to horizontally position the auxiliary beam  22  with respect to the engine core  12  (or other item supported by the assembly  10 ) as desired. The engine core  12  and the central beam  16  can remain static while the auxiliary beam  22  is adjusted, allowing items supported by one or both hoist assemblies  27 A and  27 B to be horizontally repositioned for use in assembly operations. This can reduce the need to move the large, heavy engine core  12  at any components of engine modules already attached to the engine core  12  during assembly. 
   In the embodiment shown in  FIG. 1 , the first and second sets of cross beams  18  and  20  each extend laterally from the central beam  16 , that is, horizontally at approximately 90° with respect to the central beam  16 . It should be noted that the first and second sets of cross beams  18  and  20  can be arranged differently (e.g., at angles other than 90° with respect to the central beam  16 ) in alternative embodiments. Attachment brackets  32  are located at opposite ends of both the first and second sets of cross beams  18  and  20 . 
   A pair of first support links (or connectors)  34  are pivotally suspended from each of the attachment brackets  32  of the first set of cross beams  18 . Each first support link  34  is a rigid tubular member having an upper end  34 A, a lower end  34 B and a middle portion  34 C, with the upper ends  34 A being connected to attachment brackets  32 . The middle portion  34 C of the first support links  34  have a curved shape so as to provide additional space for engine components. However, the upper and lower ends  34 A and  34 B are substantially vertically aligned, so as not to produce any moment on engine components supported by the support beam assembly  10 . Moments can stress engine components during assembly, and are generally undesired. As shown in  FIG. 1 , the engine core  12  is pivotally connected to the lower ends  34 B of the first support links  34  with pin and spherical ball joint assemblies  36  (on one visible in  FIG. 1 ), which permit pivotal movement of the engine core  12  with respect to the support beam assembly  10  in at least two directions. It should be noted that other types of connection assemblies can be used to connect the engine core  12  to the first support links  34  in alternative embodiments. Moreover, the particular shape and design of the first support links  34  can vary as desired to accommodate the configurations of particular engines supported by the support beam assembly  10 . 
   A pair of second support links (or connectors)  38  are pivotally suspended from the attachment brackets  32  of the second set of cross beams  20 . The second support links  38  are substantially solid, rigid beams each having an upper end  38 A, a lower end  38 B and a middle portion  38 C, and the second support links  38  each have a substantially straight shape. That straight shape substantially vertically aligns the upper and lower ends  38 A and  38 B, so that the second support links  38  do not to produce any moment on engine components supported by the support beam assembly  10 . As shown in  FIG. 1 , the engine core  12  is pivotally connected to the lower ends  38 B of the second support links  38  with pin and two-way pivot assemblies  40  (only one visible in  FIG. 1 ), which permit pivotal movement of the engine core  12  with respect to the support beam assembly  10  in two directions. It should be noted that other types of connection assemblies can be used to connect the engine core  12  to the second support links  38  in alternative embodiments. Moreover, the particular shape and design of the second support links  38  will vary to accommodate the configurations of particular engines to be supported with the support beam assembly  10 . 
   The first and second pairs of support links  34  and  38  are attached to the engine core  12  at designated connection points on the engine core  12 , which are typically locations on an engine case portion. That is, the engine core  12  is connected to the support beam assembly  10  at suitable locations so that the engine is balanced during assembly and so that the engine is not damaged. It should be noted that although a gas turbine engine core is supported by the support beam assembly  10  in  FIG. 1 , other types of engine and other structures can also be supported by the assembly  10 . 
   The support beam assembly  10  is configured to support engines having a total weight of about 7,257 kg (16,000 lbs.) with a suitable safety margin (e.g., a 5× safety margin). The engine is supported in a relatively rigid and balanced manner, and the support beam assembly  10  is configured to avoid placing any moments on the engine while being assembled. However, pivotal connections are provided with the support beam assembly  10 , as described above with respect to assemblies  36  and  40 , so that about 9-11° of “swing” is provided to avoid the abrupt transmission of forces that could otherwise cause damage to the engine being assembled or cause damage to the support beam assembly  10  by snapping one or more of the supports  34  and  38 . 
     FIGS. 2 and 3  illustrate another embodiment of a support beam assembly  110 .  FIG. 2  is a side view, and  FIG. 3  is a top view. The support beam assembly  110  is generally similar to the assembly  10  shown in  FIG. 1 . However, as shown in  FIGS. 2 and 3 , the auxiliary beam  22  has first and second raised ends  22 A and  22 B to which the hoists  27 A and  27 B are attached. Moreover, attachment structures  142  are located at the top of the central beam  16  of the support beam assembly  110 , to enable attachment of overhead supports (e.g., adjustable link assemblies like those shown in  FIG. 1 ). The attachments structures  142  are located relative to the center of gravity of the engine being assembled, to better balance loads supported by the support beam assembly  110 . 
     FIG. 4  is a schematic illustration of an engine support system  200  that includes an overhead monorail track  202  and assembly stations A-G located along the track  202 . As shown in  FIG. 4 , engines in various assembly states are shown at each station. However, those skilled in the art will recognize that typically only a single engine will be supported from a particular track at a given time. Moreover, those skilled in the art will recognize that the particular modules, components, and tooling utilized by workers at any particular station can vary. In that respect, the assembly operations shown in  FIG. 4  and described herein are provided by merely way of example, and not limitation. 
   Turning first to station A, a pair of adjustable links  14  are suspended from the track  202  by conventional trolleys  204 . A support beam assembly  206 , like those shown and described with respect to  FIGS. 1-3 , is bolted to the adjustable links  14 . A gas turbine engine core  208  is attached to support beam assembly  206  at station A, and various assembly procedures can be performed. The engine core  208  is lifted from a platform  210 , where the core  208  originally rested. 
   At stations B-G, additional assembly operations are performed. Typically, the trolleys  204  are moved along the track  202  sequentially to all the stations A-G in order to assembly the engine. Thus, the trolleys  204 , the adjustable links  14 , the support beam assembly  206  and attached engine core  208  are moved along the track from station A to station B, where tooling  212  is moved into place with a first hoist  214  on an auxiliary beam  216  of the support beam assembly  206 . Various assembly operations are performed at station B utilizing the tooling  212 . The first hoist  214  lifts relatively lightweight items while the engine core  208  is stationary along the track  202 . Horizontal adjustment of the auxiliary beam  216  and vertical adjustment of the first hoist  214  allow convenient adjustment of the tooling  212  without having to move the relatively heavy engine core  208 . 
   Next, the trolleys  204 , the adjustable links  14 , the support beam assembly  206  and attached engine core  208  are moved along the track  202  to station C. There, a first engine module  218  is lifted into place with the first hoist  214  and attached to the engine core  208 . The auxiliary beam  216  can be adjusted horizontally to accommodate attachment of the first engine module  218  to the engine core  208 , and the adjustable links  14  can likewise be adjusted vertically. 
   Similar assembly processes are performed at stations D-G (references number are omitted at stations D-G for simplicity). Then, when assembly is complete, the completed engine (i.e., the engine core  208  with all desired engine modules and engine components installed thereupon) is detached from the support beam assembly  206  and can be transported away from the assembly facility for eventual installation on an aircraft. 
   It will be understood that the present invention provides numerous advantages. For example, the support beam assembly provides a relatively fixed connection to an engine during assembly, which eliminates the need to suspend the engine from cable or chain hoists while being moved along a track. Moreover, in providing better, more secure connections to the engine through rigid members of the support beam assembly, a safer work environment is provided for workers assembling engines. 
   Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. For instance, the particular size, shape and configuration of the support beam assembly according to the present invention will vary according to the particular application (e.g., the particular type of engine being assembled). In addition, it should be recognized that features such as the auxiliary support beam are optional and may be omitted in various embodiments.