Rear disc of a stack of aircraft carbon brake discs with pucks, and brake applying the same

Abstract

A rear disc of a stack of aircraft carbon brake discs intended to rest against one end of the torque tube of the brake on which the disc stack is threaded, the support being provided by pucks secured to the rear disc by rivets, each inserted into a through hole in the rear disc and a hole opposite one of the pucks. According to the invention, each rivet has a cylindrical rod inserted into the holes of the rear disc and the puck and having an end deformed against the puck, and a head having a circular cylindrical portion with a conical base having an outer peripheral surface connected to a conical surface of the base by a fillet, and the disc through hole has a first portion adapted to receive the rod of the adjusting rivet, a second portion adapted to receive the circular cylindrical portion of the head of the adjusting rivet, and a transition conical portion adapted to receive the conical base of the rivet head.

Claims

1. A rear disc of a stack of aircraft carbon brake discs intended to rest against one end of a torque tube of the brake on which the stack is threaded, support being provided by means of pucks secured to the rear disc by rivets each inserted into a through hole in the rear disc and a hole opposite one of the pucks, wherein each rivet has a cylindrical rod inserted into the holes of the rear disc and of the puck and having an end deformed against the puck, and a head having a circular cylindrical portion with a conical base having an outer peripheral surface connected to a conical surface of the base by a fillet, and wherein the disc through hole has a first portion adapted to receive the rod of one of the rivets, a second portion adapted to receive the circular cylindrical portion of the head of one of the rivets, and a transition conical portion adapted to receive the conical base of the rivet head.

2. The rear disc according to claim 1, wherein the rivet rod has a hollow end.

3. The rear disc according to claim 1, wherein the circular cylindrical portion of the rivet head is hollow.

4. The rear disc according to claim 1, wherein the circular cylindrical portion of the rivet head has a height equal to at least 20% of an outer diameter of the circular cylindrical portion.

5. The rear disc according to claim 1, wherein the first portion of the rear disc hole has a length between 80% and 120% of a length of the hole opposite the puck.

6. An aircraft brake including a rear disc according to claim 1.

7. A brake system, comprising: a brake disc having through holes; a plurality of pucks having through holes; and a plurality of rivets securing the pucks to the brake disc, the plurality of rivets being received in the through holes of the brake disc and the pucks, each of the plurality of rivets comprising: a cylindrical rod inserted into the through holes of the brake disc and of the pucks and having an end deformed against the puck; and a head having a circular cylindrical portion with a conical base having an outer peripheral surface connected to a conical surface of the base by a fillet, wherein the disc through holes each have a first portion adapted to receive the cylindrical rod of one of the rivets, a second portion adapted to receive the circular cylindrical portion of the head of one of the rivets, and a transition conical portion adapted to receive the conical base of the head.

Description

DESCRIPTION OF THE FIGURES

(1) The invention will be better understood upon reading the following description of one specific embodiment of the invention, and while referring to the appended figures, wherein:

(2) FIG. 1 is a cross-sectional view along a central axis of the brake of an aircraft rear brake disc at one of the holes receiving a rivet for fixing a puck being secured according to the invention;

(3) FIG. 2 is a view similar to that of FIG. 1, showing the puck secured to the rear disc.

DETAILED DESCRIPTION OF THE INVENTION

(4) The invention applies to the connection between an aircraft carbon rear brake disc 4 and pucks 5. Rear disc means the carbon element which rests, through the pucks, against the end of the brake torque tube on which the disc stack is threaded. This is usually the last stator disc in the brake discs stack.

(5) According to the invention, each puck 5 is attached to the rear disc 4 according to the following provisions. As shown in FIG. 1, the rear disc 4 includes, for each puck 5, a through hole 10 with a first portion 11 with a first diameter D1 on the side intended to receive the puck 5, and a second portion 12 with a second diameter D2 larger than the first diameter, the transition between the two portions being provided by a conical shoulder 13. The puck 5 has a through hole 14 with a diameter equal to or similar to D1.

(6) To secure the puck 5 to the rear disc 4, a rivet 20 is used which, according to the invention, has a rod 21 with a diameter slightly smaller than D1 to be able to fit into the first portion 11 of the hole 10 of the rear disc 4 and into the hole 14 of the puck 5. The rod 21 here has a hollow end 22 for its crushing against the puck 5. The rivet 5 also has a head 23 which includes a conical base 24 intended to rest against the conical shoulder 13 of the hole 10, surmounted by a hollow circular cylindrical portion 25 with an external diameter D slightly smaller than D2 so that it can be fitted into the second portion 12 of the hole 10 of the rear disc 4. The circular cylindrical portion 25 of the head 23 thus forms a skirt that guides the rivet 20 when it is placed in the hole 10 and ensures that the rod 21 actually penetrates into the first portion 11 of said hole, without being askew.

(7) As shown in FIG. 2, the end of the rod 21 is then crushed against the puck 5 to secure it to the rear disc 4. The conical base 24 then rests against the conical shoulder 13, and the peripheral outer surface 26 of the circular portion 25 of the head 23 constitutes a bearing surface against the carbon of the rear disc with a large surface area able to reduce the caulking pressure between the rivet 20 and carbon. In addition, a fillet (see detail A in FIG. 1) connects the peripheral outer surface 26 of the circular portion 25 to a conical outer surface 28 of its conical base 24, further reducing the risk of damaging carbon on the rear disc 4.

(8) Preferably, the circular cylindrical portion 25 of the head 23 has a height h equal to at least 20% of the outer diameter D of said portion. In addition, when the rivet 20 is fitted, the length l.sub.1 of the portion 11 of diameter D1 of the hole 10 of the rear disc 4 is greater than the length l.sub.2 of the hole 14 of the puck 5. Preferably, the length l.sub.1 is similar to the length l.sub.2, preferably in a range of 80% to 120% of the length l.sub.2. These provisions further reduce the risk of damaging carbon on the rear disc 4.

(9) The invention is not limited to what has just been described, but encompasses every alternative solution within the scope of the claims. In particular, although here the rivet head is hollow for mass reasons, the rivet head may be solid. However, it is important that the head has a conical base followed by a circular cylindrical portion.