GB2362346A

GB2362346A - Adjustable support device

Info

Publication number: GB2362346A
Application number: GB0011242A
Authority: GB
Inventors: Leigh Pragnell
Original assignee: GKN Aerospace Services Ltd; GKN Westland Aerospace Inc
Current assignee: GKN Aerospace Services Ltd; GKN Westland Aerospace Inc
Priority date: 2000-05-11
Filing date: 2000-05-11
Publication date: 2001-11-21
Anticipated expiration: 2020-05-11
Also published as: GB0011242D0; GB2362346B

Abstract

A jig for holding a workpiece, particularly an engine nacelle (60), cantilevered from an end (70) of the jig. The nacelle is secured to a frame (50) which can be moved vertically by a hydraulic cylinder (28). Thee frame is mounted on a shaft (17) which can be rotated by an electric motor (18).

Description

1 2362346 1 Jig for Workpiece

Technical Field

This invention relates to ajig for holding a workpiece. In particular, the invention relates to a jig for holding a workpiece in the form of an aircraft engine nacelle. The invention also includes a method of assembling or repairing an engine aircraft nacelle while supported by the jig.

Background Art

At present, when carrying out the assembly or repair of an aircraft engine nacelle which is not mounted on the aircraft it is necessary to hold the nacelle on a jig. Heretofore it has been necessary to provide staging alongside the nacelle which is moved into position when required to get at the upper parts of the nacelle and is moved away when it is necessary to get in the lower parts of the nacelle. Moreover, the staging extends down the sides of the nacelle and can impede the work on the nacelle.

Disclosure of the Invention

It is an object of the present invention to provide an improved jig which facilitates the holding of e.g. a nacelle during assembly and repair and which does not require the use of staging.

According to one aspect of the invention we provide a jig for holding a workpiece comprising a base frame, a vertical frame secured to the base frame, a pair of spaced-apart vertical rails secured within the vertical frame, a carriage mounted on said rails for vertical movement therein, means to move the carriage vertically along the rails, a shaft mounted on said carriage for rotation about a horizontal axis, means to rotate the shaft and a work holder carried by the shaft.

The base frame may be H-shaped with the cross member of the H being nearer one end of the frame than the other, the work holder being located adjacent said other end of the frame.

The work holder may have means for locating the workpiece, said means being approximately aligned with said other end of the frame so that the workpiece may be cantilevered from the jig.

This means that those working on the workpiece are not impeded by the jig.

The jig may include a vertically adjustable support mounted on the base frame to support the carriage. The carriage may be moved vertically by a hydraulic cylinder. Thus the carriage may be connected to one end of a chain the other end of which is connected to the base frame, the chain running round a roller which is movable by the hydraulic cylinder to raise and lower the 2 carriage.

The carnage may carry a motor and gear box to rotate the shaft. The jig is preferably mounted on wheels or castors so as to be movable.

According to another aspect of the invention we provide the combination of a jig as described above with a workpiece in which the workpiece is cantilevered from the work holder so that the base frame does not extend to any significant extent under the workpiece. The workpiece is conveniently an aircraft engine nacelle but could, for example, be an engine or other assembly required to be worked on.

According to a further aspect of the invention we provide a method of assembling or repairing an aircraft engine nacelle which includes securing one end of the nacelle to a work holder carried by a jig so that the nacelle is held clear of the ground and during said assembly or repair rotating the work holder about a horizontal axis and/or moving the work holder vertically as required for access. Preferably the nacelle is cantilevered from the jig so that the jig does not impede access to the nacelle during said assembly or repair.

Brief Description of the Drawings

The invention will now be described in detail by way of example with reference to the accompanying drawings in which:

Figure I is a side elevation of ajig embodying the invention with an aircraft engine nacelle shown in dotted lines supported by the jig, Figure 2 is a plan view of the jig of Figure 1 Figure 3 is an elevation of the jig in the direction of the arrow 3 in Figure 1; and Figure 4 is a detailed view of the nacelle support.

Best Mode for CarLrying Out the Invention Referring now to the drawings, thejig comprises a base indicated generally at 10. The base is of H-shape in plan as clearly shown in Figure 2 and has two longitudinal members 11 and a cross-member 12. As clearly shown in Figures 1 and 3 thejig is mounted on castors 13 at the ends of the longitudinal members 11.

Mounted on the cross-member are two vertical channels 14 whose open mouths face one another and which provide guidance for a vertically movable table 15 described below. The table carries two spaced bearings 16 in which is rotatable a shaft 17. The shaft is rotatable by an electric motor 18 via a gearbox 19. The table 15 is guided in the channels 14 by four rollers, two 3 upper rollers 20 and two lower rollers 2 1. The rollers 20 are mounted on upstanding flange plates 22 on the table. The lower rollers are mounted on gusset plates 23 which are connected to a vertical plate 24 to which the table 15 is also connected, At its lower end the vertical plate has a flange 25. The jig also includes vertical structure 26 which is adjacent to the channels 24 and consists of fabricated channels 27. Within the vertical structure 26 is mounted a single acting hydraulic cylinder 28 the cylinder of which is secured to the base of the jig. The piston rod 29 carries two rollers 3 0 at its upper end. The shaft 3 1 on which the rollers 3 0 are mounted i s guided by a slot in a plate member 32, the slot being indicated at 33 in Figure 1.

A chain 34 is entrained around each pulley and one end of each chain is anchored at 35 on the base frame. The other end of each chain is anchored at 36 to the flange 25 which is connected to the table 15. It will be seen that by movement of the piston rod 29 of the hydraulic cylinder 28 the table 15 may be moved up and down. Operation of the cylinder is from a hydraulic pump 37 associated with an accumulator 38 and driven by an electric motor 39.

A sloping stay structure 40 extends between the vertical structure 26 and one end 41 of the base frame. As seen in Figure 3 this structure 40 tapers towards its upper end and is connected to other stays 42 to rigidify the assembly. Carried by the shaft 17 rotatable on the table 15 is a frame for holding an engine nacelle. The frame is indicated generally at 50 and has an end wall 51 which is bolted to a face plate 52 on the shaft 17 by bolts 53. Secured to the end plate 51 are two box-like girders 54 which is a plate like form each having an aperture 55 therein. Each girder carries, at the end remote from the face plate 5 1, two mounting bosses 56 for engaging in apertures in a nacelle which would, in the aircraft in which the nacelle is fitted, be used to locate the nacelle in the aircraft.

In use, the nacelle, which is indicated generally at 60, has a rear portion 61 which is engaged with the bosses 56 and is secured in position to the frame 50 by bolts, not shown. It will be seen that the nacelle can be rotated by turning the frame 50 via the shaft 17 from the electric motor 18.

Moreover, the nacelle can be moved vertically by operation of the hydraulic cylinder 28 which will move the table up and down in the channels 14.

Because the nacelle is weighty and because it is cantilevered from the frame 50 it is desirable to have a stay 62 which comprises a lower tubular part 63 secured to the base at 64 and an upper tubular part 65 which slides in the part 63 and is secured to a bracket 66 on the 4 underside of the table 15. The upper tubular part has apertures 67 spaced apart along its length and can be locked in a desired position with respect to the lower tube 63 by a pin 68 passing through holes not shown in the lower part 62 and one of the holes 67 in the upper part During vertical adjustment of the table the pin 68 would be removed so that the parts 62 and 65 can slide relative to one another until the nacelle reaches the desired position whereupon the pin 68 could be inserted to assist in supporting the table 15 bearing the weight of the nacelle.

It is to be noted from Figure 1 that the nacelle 60 is, as mentioned, cantilevered from the jig. The jig is so constructed that the nacelle can be cantilevered from it without tipping over. It will be seen that the nacelle is substantially clear of the end 70 of the jig so that people working on the nacelle may do so clear of the jig. The jig is mounted on castors 71 so that it may be easily moved.

The jig is extremely useful for assembling and repairing engine nacelles since the nacelle is clear of thejig leaving an uninterrupted space for working on the nacelle. The nacelle can easily be turned by operation of the electric motor 18 or raised and lowered by operation of the hydraulic cylinder 28.

It will be seen that the invention provides a very convenientfig for the assembly and repair of engine nacelles.

The invention also provides a method of assembling or repairing an aircraft engine nacelle by securing the nacelle to the frame 50 so that the nacelle is held clear of the ground during which the nacelle can be raised or lowered with respect to the ground and rotated. As mentioned above it is important that the nacelle is cantilevered from the jig so that the jig does not obstruct people working on the nacelle.

Although the invention has been described specifically with reference to an engine nacelle, the jig could carry other workpieces such as engines.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

Clailns

1. A jig for holding a workpiece comprising a base frame, a vertical frame secured to the base frame, a pair of spaced-apart vertical rails secured within the vertical frame, a carriage mounted on said rails for vertical movement therein, means to move the carriage vertically along the rails, a shaft mounted on said carriage for rotation about a horizontal axis, means to rotate the shaft and a work holder carried by the shaft.

I Ajig according to Claim I wherein the base frame is H-shaped with the cross member of the H being nearer one end of the frame than the other, the work holder being located adjacent said other end of the frame.

3. Ajig according to Claim 2 wherein the work holder has means for locating the workpiece, said means being approximately aligned with said other end of the frame so that the workpiece may be cantilevered from the jig.

A jig according to any preceding claim wherein the jig includes a vertically adjustable support mounted on the base frame to support the carriage.

5. A jig according to any preceding claim wherein the carriage is moved vertically by a hydraulic cylinder.

6. A fig according to Claim 5 wherein the carriage is connected to one end of a chain the other end of which is connected to the base frame, the chain running round a roller which is movable by the hydraulic cylinder to raise and lower the carriage.

7, A jig according to any preceding claim wherein the carriage carries a motor and gear box to rotate the shaft.

8. The combination of a jig as claimed in any preceding claim with a workpiece in which the workpiece is cantilevered from the work holder so that the base frame does not extend to 6 any significant extent under the workplece.

9. The combination according to Claim 8 wherein the workpiece is an aircraft engine nacelle.

10. A rnethod of assembling or repairing an aircraft engine nacelle which includes securing one end of the nacelle to a work holder carried by a jig so that the nacelle is held clear of the ground and during said assembly or repair rotating the work holder about a horizontal axis and/or moving the work holder vertically as required for access.

11.A method according to Claim 10 wherein the nacelle is cantilevered from the jig so that the jig does not impede access to the nacelle during said assembly or repair.

A method according to Claims 10 and 11 wherein the jig is as claimed in any of Claims 1 to 7.

Ajig for holding a workpiece substantially as hereinbefore described with reference to and as shown in accompanying drawings.

14. A method of assembly or repairing an aircraft engine nacelle substantially as hereinbefore described with reference to the accompanying drawings.