GB2154335A

GB2154335A - Endoscope for inspecting power plant

Info

Publication number: GB2154335A
Application number: GB08501666A
Authority: GB
Inventors: Jorg Diener; Ehrenfried Bitrolf
Original assignee: Richard Wolf GmbH
Current assignee: Richard Wolf GmbH
Priority date: 1984-02-16
Filing date: 1985-01-23
Publication date: 1985-09-04
Also published as: DE3405514C2; DE3405514A1; FR2561399A1; GB8501666D0; FR2561399B1; GB2154335B

Abstract

A technoscope for internal inspection of power plant such as special aircraft power units equipped with non-circular, preferably cornered (e.g. square) wall ports comprises a first rigid guide shaft (1) of non-circular cross- section insertible into one of the wall ports and having a lateral distal outlet (4), and a guiding element (2) which passes through said first guide shaft (1) and has a flexible distal portion (14), an intermediate portion (13) whose cross-section matches that of the first guide shaft (1) and a proximal control system (9, 10) for controlled deflection of said flexible distal end. The guiding element is used to guide a flexible endoscope shaft (3) to the desired site within the plant to be inspected. <IMAGE>

Description

SPECIFICATION Technoscope The invention relates to a technoscope, in particular for inspection of aircraft power plants which have casing walls equipped with closable non-circular (typically square) ports for traversal by the technoscope.

It is known that cavities in machinery and the like may be inspected by means of rigid or flexible endoscopes, steerable flexible endoscopes having advantages in this connection but being excluded for inspection of aircraft power plant of special construction since they fail to meet the special requirements for this purpose, namely that they should be of great mechanical strength and also flexible and able to follow abrupt changes in direction, whilst at the same time having a particular degree of rigidity so that they may bridge greater distances up to the point of inspection without significant deflection, and be inserted in existing openings of particular geometrical shape and size.

The present invention consists in a technoscope for internal inspection of power plants and the like by insertion through a wall port thereof, comprising a first rigid guide shaft of non-circular cross-section for insertion in said wall port, said shaft having a distal end equipped with a lateral outlet guide, and a flexible guiding element adapted to pass through said guide shaft with a sliding fit, said guiding element having a deflectable distal end portion, a proximal control system for controlling said distal end and an axially intermediate portion whose cross-section is complementary with the internal cross-section of the guide shaft, and having an axial opening therethrough for the passage of a flexible endoscope.

In accordance with the invention a flexible endoscope, which may be of a conventional type, is combined with two guiding systems, namely a rigid guide shaft which is passed through the frequently very sharp-edged wall openings of the power plant and thereby prevents damage to the flexible endoscope, and then with a guiding element which may be passed through the rigid guide shaft and in turn receives the flexible endoscope, which has a comparatively low degree of flexibility along its greater portion and may be steered optionally at its distal extremity by manipulation, in which connection it is possible to bridge greater distances and to offer up the endoscope passed through to the parts to be inspected by means of its distal lens.

In this connection, it is advantageous to construct the steerable guiding element so that the flexible guiding element comprises a proximal longitudinal portion having a comparatively low degree of flexibility and preferably comprising two coils of metal strip wound in opposed directions and in close mutual contact, and joined thereto a steerable distal longitudinal portion comprising known segments pivotable with respect to each other.

In this way, it is possible to bridge greater distances by means of the proximal longitudinal portion of relatively low flexibility and even abrupt deflections may be obtained as desired for the flexible endoscope passed through.

The invention is described in the following with reference to the drawings in which an example of embodiment is illustrated diagrammatically.

Figure 1 shows a guiding shaft insertible in a casing wall perforation of a power plant in lateral view and partial distal longitudinal cross-section, Figure 2 shows a plan view of the guiding shaft according to Figure 1, Figure 3 shows a side view of a guiding element for a flexible endoscope, which may be passed through the guiding shaft according to Figure 1, Figures 4 and 5 show cross-sections along the lines IV-IV and V-V of Figure 3, Figure 6 shows a view of the technoscope under application in a combustion chamber of a power plant.

The technoscope shown in the drawings comprises three parts which are to be combined with each other, namely a short guiding shaft 1 (Figures 1 and 6), a guiding element (Figures 3,4,5 and 6) extending through the guiding shaft 1, and a flexible endoscope 3 of known type whereof the proximal and distal parts are visible in Figure 6.

The guiding shaft 1 is a rigid metal shaft of non-circular, preferably cornered cross-section (in this case square) which at the distal extremity is equipped with a lateral opening 4 whereof the wall section opposite to the opening forms an arcuate terminal guiding surface 5 of the shaft 1. The proximal extremity of the opening is delimited by a projection 6 of an elastic wall tongue or strip 7. At its proximal side, the projection 6 forms an angle with the axis of the shaft 1.The guiding shaft 1 may be inserted by grasping the proximal extremity 1a, into an advantageously closable perforation of rectangular or square cross-section of the wall of a power plant casing X, the projection 6 of the strip Z initially giving way inwards and finally springing back elastically outwards after the shaft 1 has been fully inserted through the wall perforation, and thereby preventing the shaft 1 from dropping out of the wall perforation accidentally. As soon as the projection 6 engages behind the outer combustion chamber wall, the flange 8 bears externally against the casing wall X of the power plant. The shaft 1 may be pulled out of the wall perforation by means of the handle 1a.

The guiding element 2 is passed through the rigid inserted guiding shaft 1. This element comprises a proximal control casing 9 having steering handles 10 and a mount 11 comprising clamping means 12 for securing a flexible endoscope 3 of known type (Figure 6).

The control casing 9 is joined by a shaft 2 having a longer longitudinal portion 1 3 and a shorter distal longitudinal portion 1 4. The longitudinal portion 1 3 has a lower degree of flexibility than known flexible endoscopes and is produced from two metal coils 1 5 and 1 6 wound contradirectionally and lying one over the other, having a slightly larger diameter 1 7 than that of the endoscope 3 which is to be passed through.The coils 1 5 and 1 6 are enclosed by wire netting 1 8 as well as by a shrunk-on tube, the control wires extending between these and the coils and within guiding sleeves 19, so that the proximal longitudinal portion 1 3 of the guiding element assumes an essentially square cross-section.

The distal longitudinal portion 14 of the guiding element 2 whose internal diameter corresponds to the diameter 1 7 of the longitudinal portion 13, comprises flexible interconnected segments 21 which are axially pivotable with respect to each other, as is known in endoscope technology, and-in this cas e-the guiding sleeves 1 9 are situated on the inner side of the segments without reducing the diameter 17.

After the rigid guiding shaft 1 has been inserted into a selected power plant port and has been secured in a stable position by engagement of the projection 6 behind the outer combustion chamber wall, the flexible guiding element 2 and the flexible endoscope already pushed into the same, may conjointly be inserted into the combustion space of the power unit through the rigid guiding shaft 1.

Since the distal extremities of the flexible endoscope and of the flexible guiding element 2 lie at the same level upon insertion into the combustion space, it is already possible to check on the direction of displacement through the flexible endoscope upon reaching the combustion space, and to make a selection of points for closer visual inspection. By means of the controllable guiding portion 14 of the guiding element 2, it is possible to steer the flexible endoscope in any optional direction, and the same may have its objective lens extremity emerging out of the distal extremity of the guiding element 2 guided onwards in the direction towards a selected point within the power unit, and a thorough visual inspection may be performed by distalside steering of the flexible endoscope.

Thanks to the guiding portion 1 3 of comparatively low flexibility of the guiding element 2, the flexible endoscope utilised for inspection may also be led over greater areas within the combustion chamber of the power unit, without substantial directional deflections.

Claims

1. A technoscope for internal inspection of power plants and the like by insertion through a wall port thereof, comprising: a first rigid guide shaft of non-circular crosssection for insertion in said wall port, said shaft having a distal end equipped with a lateral outlet guide, and a flexible guiding element adapted to pass through said guide shaft with a sliding fit, said guiding element having a deflectable distal end portion, a proximal control system for controlling said distal end and an axially intermediate portion whose cross-section is complementary with the internal cross-section of the guide shaft, and having an axial opening therethrough for the passage of a flexible endoscope

2.A technoscope according to claim 1, wherein said flexible guiding element comprises two portions of different flexibility, said distal end portion having a circular crosssection and being unrestrictedly deflectible via internally situated control wires, and said intermediate portion, which extends proximally up to a control casing, has a lesser degree of flexibility and is equipped with externally led control wires.

3. A technoscope according to claim 2, wherein said intermediate portion displaying said lesser degree of flexibility has several guideways for reception of distally acting control wires positioned radially and axially at constant spacings from each other on the outer of two coils which are wound in opposed directions and are in close contact with each other.

4. A technoscope according to claim 3, wherein said guideways arranged internally in the deflectable portion and externally in the intermediate portion of lesser flexibility are in mutual axial alignment and wherein said two portions of different flexibility each have empty axial passages for traversal by a flexible endoscope.

5. A technoscope according to any preceding claim, wherein said control system of the guiding element includes a mounting at the proximal end of the guiding element and means for releasably securing a flexible endoscope inserted into the guiding element.

6. A technoscope according to any preceding claim, wherein said rigid guide shaft has its distal end closed off by a guiding surface arranged opposite to said lateral outlet and rising towards the distal extremity of the outlet, and wherein the proximal extremity of the outlet terminates with an obtuse projection subtending an angle with the axis of the shaft, on a resiliently pivotable tongue integral with the shaft wall.

7. A technoscope according to claim 6, wherein said rigid guide shaft has a radially extending stop to bear against an outer power plant jacket of the plant being inspected, said obtuse projection being axially spaced from said stop for engagement behind an outer combustion chamber wall.

8. A technoscope substantially as described with reference to and as illustrated in the accompanying drawings.