US 2021/0229199 A1Published application

Method and tool for reconditioning a damaged thread

AssigneeLeonardo S.P.A.

InventorsDario Colombo, Roberto Regonini, Sergio Fiorio

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Abstract

It is described a method for reconditioning a damaged thread of a transmission of a hover-capable aircraft; the damaged thread being arranged inside a first hole of the transmission; wherein the method includes the following steps: i) centering a tool on the first hole; ii) inserting a first tool inside the tool centred on the first hole and removing the damaged thread through the first tool; iii) inserting a second tool inside the tool and creating a new thread inside the first hole having a diameter larger than the one of the damaged thread; iv) screwing an insert having a thread inside the new thread, so that the insert engages the first hole and defines a reconditioned thread; and v) keeping the transmission mounted on the hover-capable aircraft during steps i), ii), iii), iv).

Claims12

Dependent claims

Method for reconditioning a damaged thread (8) of a transmission (1) of a hover-capable aircraft;

said damaged thread (8) being arranged inside a first hole (23a) of said transmission (1);
said method comprising the following steps:
i) centering a tool (20) on said first hole (23a);
ii) inserting a first tool (25) inside said tool (20) centred on said first hole (23a) and removing the damaged thread (8) by means of said first tool (25);
iii) inserting a second tool (26) inside said tool (20) and creating a new thread (16) inside said first hole (23a) having a diameter larger than the one of said damaged thread (8);
and
iv) screwing an insert (61) having a thread inside said new thread (16), so that said insert (61) engages said first hole (23a) and defines a reconditioned thread (8′);
said step i) comprising the following steps:
v) inserting a pin (33) inside said tool (20) and inside said first hole (23a);
and
vi) removing the pin (33);
characterized in that said step i) comprises the steps of:
vii) screwing said pin (33) onto a further thread (30) of said tool (20);
and
viii) arranging said pin (33) in abutment against an abutment surface (32) of said tool (20);
said method being further characterized by comprising the step of:
ix) keeping said transmission (1) mounted on the hover-capable aircraft during said steps i), ii), iii), vii).

14 more elements

A tool (20) for reconditioning a damaged thread (8) of a transmission (1) of a hover-capable aircraft, comprising:

a first bracket (21) adapted to be arranged at a first hole (23a) of said transmission (1) defining said damaged thread (8) and defining a second through hole (24) engageable by one or more tools (25, 26, 60) suitable for interacting with said damaged thread (8) and adapted to be centred on said first hole (23a);
at least two second brackets (22) articulated on said bracket (21) and defining respective seats (19) engageable by respective connecting elements (6b) engaging respective third holes (23b) of said transmission (1) adjacent to said first hole (23a) defining said damaged thread (8);
said second hole (24) defining a nut screw (30);
and
a centering pin (33);
said pin (33) comprising an end (38) adapted to engage said first hole (23a) during said centering operation;
characterized in that said pin (33) comprises:
a screw (37) that can be screwed onto said nut screw (30) during a centering operation of said first bracket (21) on said first hole (23a);
said pin (33) further comprising:
a cover (34) adapted to abut against an abutment surface (32) of said first bracket (21) during a centering step of said tool (20);
a non-threaded portion (42) adapted to engage a non-threaded portion (39) asxially opposite to said screw (37) of said second hole (24) during a centering step of the tool 20;
a portion (35) defining said screw (37);
a connecting portion (36) having a frustoconical shape;
and
a non-threaded cylindrical section (38) adapted to engage said first hole (23a).

12 more elements

Dependencies are inferred from the claim text.

Facts

Application: 17/055,030Filed 17 Oct 2019
Priority: EP 18201060.317 Oct 2018
Published: 29 Jul 2021
Term ends: Not estimatedThe source records don’t support an estimate.

Classification11 codes

B23P 6/00
Restoring or reconditioning objects
B23B 49/023
Boring templates or bushings: bushings and their connection to the template
B23B 49/026
Boring templates or bushings: boring bushing carriers attached to the workpiece by glue, magnets, suction devices or the like
B23G 1/16
Thread cutting; Automatic machines specially designed therefor: in holes of workpieces by taps