| WO1983002651A1 | 1983-08-04 |
| DE806814C | 1951-06-18 | |||
| FR2452033A2 | 1980-10-17 | |||
| DE2410522A1 | 1974-12-12 |
| 1. | Method for making such a brake block as consists of a base <1) and two from each other in material different friction pieces (4, 5) in such a way that the middle is softer than the edges, in which method the friction piece is pressed on the base (1) with a piston at a high temperature in such a way that on the base (1) are placed two pieces of friction material (4, 5) that are different in hardness, c h a r a c t e r i z e d by that the harder piece of friction material (4) is on the edges and the softer piece of friction material (5) is in the middle, after which the materials are pressed on the base (1) and together. |
| 2. | Method conforming to Claim 1, c h a r a c t e r i z e d by that the harder piece of friction material (4) consists of a cupshaped piece which is placed on the base (1) and into which the softer piece of friction material (5) is inserted, after which the pressing together is carried out. |
This invention is concerned with a method for making such a brake block as consists of a base and two from each other in material different friction pieces in such a way that the middle is softer than the edges, in which method the friction piece is pressed on the base with a piston at a high temperature in such a way that on the base are placed two pieces of friction material that are different in hardness.
This kind of method for making a brake block is presented e.g. in the Finnish Patent no. 64443. The object of this invention is to develop that manufacturing method further. A method based on this invention is characterized by that the harder piece of friction material is on the edges and the softer piece of friction material is in the middle, after which the materials are pressed on the base and together. This invention eliminates the need for presses of special construction in which the friction materials are extruded into specially made moulds and by this means at the same time attached to their bases. With this new method it is possible to use known normal brake—block presses, which are simple in construction and already available on the market.
An a d vantageous application of this invention is characterized by that the harder piece of friction material consists of a cup—shaped piece which is placed on the base and into which the softer piece of friction material is inserted, after which the pressing together is carried out. Thereby is achieved a better sticking to each other between the friction pieces and a better sticking to each other between the base and the whole friction pieces element.
Below, the invention is described by means of an example, with reference to the enclosed drawing where
Figure 1 shows a brake block conforming to an application of the invention, with the mould split, before the pressing is carried out,
Figure 2 shows a brake block conforming to another application of the invention before the pressing is carried out.
The base 1 of the brake block is placed on a hot plate 2 and round the base comes a mould 3. The harder piece of friction material 4 is placed on the edges of the base and the softer piece of friction material 5 is placed in the middle of the base. After this the pieces of friction material 4, 5 are pressed on the base 1 and together, thanks to the thermal effect of the piston above them which serves also as a hot plate. Thereby is
achieved a brake block whose friction surface 5 has a desired coefficient of friction and whose edαes 4 have a smaller coefficient of friction and prevent impurities from Qetting between the friction surface and the brake disc and causing abrasion there.
In Figure 2 the pressing together happens in just the same way as described above, but the harder piece of friction material 4 consists of a cup—shaped piece.