The present invention is directed toward a method and apparatus for removing carbonized pitch from the surface of a pitch infiltrated disk, and, more specifically, toward a method and apparatus for removing carbonized pitch from the surface of a pitch infiltrated disk by pressing rollers against opposite sides of the disk and rotating the disk relative to the rollers.
Products such as brake disks may be formed by providing a non-woven mat or preform of carbon fibers and processing the preform in a furnace in the presence of hydrocarbons such as coal tar pitch which travel through the non-woven mat. Carbon from the pitch bonds with the carbon fibers in the mat and forms a durable, highly heat resistant material that is sometimes referred to as “carbon-carbon.” A process of forming such a carbon-carbon article is described in U.S. Pat. No. 7,063,870, to La Forest, entitled, “Manufacture of Functionally Graded Carbon-Carbon Composites,” the entire contents of which are hereby incorporated by reference.
After a plurality of furnace treatments, the spaces between the carbon fibers are substantially full of carbon atoms, and the carbon atoms and carbon fibers form a very hard product. The hydrocarbons used during the furnace process, however, also protrude from the spaces between the fibers and form a hard, porous, crust on the surfaces of the disk. This crust or flash must be removed before the disks can be used. Currently, the removal of flash may be accomplished by hand using various grinding and/or scraping tools. However, this process is time consuming and labor intensive. Furthermore, it may be difficult to determine where the flash ends and the carbonized preform begins which can lead to the disk being damaged during the deflashing process. It would therefore be desirable to provide a method and apparatus for removing the surface crust or flash in an efficient manner while substantially avoiding damage to the underlying carbon-carbon product.
These problems and others are addressed by embodiments of the present invention, a first aspect of which comprises a method of removing carbonized pitch from first and second parallel surfaces of a pitch infiltrated carbon fiber disk. The method involves providing a pitch infiltrated carbon fiber disk having a central axis, pressing a first roller against the first surface of the disk, pressing a second roller against the second surface of the disk, and rotating the disk or the rollers about the central axis of the disk to crush the carbonized pitch.
Another aspect of the invention comprises a device for removing carbonized pitch from the surface of a pitch infiltrated carbon fiber disk. The device includes a disk support for supporting a pitch infiltrated carbon fiber disk for rotation about a central axis in a plane and first and second roller supports mounted on opposite sides of the plane. First and second rollers are mounted in the first and second rollers supports, and a drive is provided for rotating the disk about the central axis between the first and second rollers.
A further aspect of the invention comprises a device for removing carbonized pitch from first and second parallel surfaces of a pitch infiltrated carbon fiber disk. The device includes a disk support for supporting a pitch infiltrated carbon fiber disk at a disk support location on the disk support, a first roller support mounted at a first side of the disk support location and a second roller support mounted at a second side of the disk support location. First and second rollers are mounted in the first and second roller supports, and a drive rotates the disk or the first and second roller supports about a central axis of the disk.
These aspects and features of the invention and others will be better understood after a reading of the following detailed description together with the following drawings wherein:
Referring now to the drawings, wherein the showings are for purposes of illustrating embodiments of the invention only and not for the purpose of limiting same,
Base member 26 has a generally planar upper surface 28 having first and second L-shaped grooves 30 and a bore 32 therein. A slider 34 having a bottom surface 36 from which project first and second L-shaped legs 38 is mounted on base member 26 with first and second L-shaped legs 38 slidably received in the first and second L-shaped grooves 30 and bottom surface 36 resting on upper surface 28 so that slider 34 can move relative to base member 26 in the longitudinal direction of the grooves 30 but not in a direction normal to the longitudinal direction of the grooves 30. A retaining pin 40 is slidably supported on slider 34 and is insertable in bore 32 in base member 26 to selectively prevent sliding movement between the slider 34 and the base member 26. More than one bore 32 may be provided to allow for finer adjustments in the relative positions of slider 34 and base 26. Other arrangements for adjustably mounting a slider on a base member could also be used without departing from the scope of the present invention.
Slider 34 includes a side face 42 having a side bore 44 and a roller support 46 having a back wall 48 having an opening 50 mounted on side face 42 with roller support opening 50 aligned with side face bore 44. Roller support 46 includes first and second side walls 52 having opposed inner surfaces 54 and a spring 56 supported therebetween. A roller 58, illustrated apart from the deflashing system in
A drive mechanism 78 comprising a motor 80 driving a shaft 82 is mounted on one of the sliders 34 and includes a drive roller 84 for frictionally engaging the outer peripheral surface 22 of disk 14.
In use, a disk 14 is placed onto support rollers 10 and the sliders 34 on opposite sides of the disk are moved relative to base members 26 to bring first and second rollers 58 into contact with the opposite parallel surfaces 18, 20 of disk 14 and to compress springs 5 to apply a desired biasing force against the first and second sides 18, 20. The force applied against disk 14 may be adjusted by a proper selection of spring strength and the relative positions of the sliders 46 and base members 26. A typical amount of force applied by the rollers might be, for example, fifty pounds. Drive roller 84 is brought into engagement with outer peripheral edge 22 of the disk and driven to cause disk 14 to rotate on its central axis on support rollers 10 between the opposed rollers 58. The flat ends 72 of teeth 70 on rolling members 66 crush the carbonized pitch on the surfaces of the disk 14 as disk 14 rotates between rotating rolling members 58. Preferably, disk 14 is mounted in a vertical orientation as illustrated in the drawing figures so that the crushed pitch falls away from disk 14 and is not ground into the surface. The portion of the disk 14 that includes reinforcing fibers is harder than the excess carbonized pitch and is not crushed or damaged by contact with the turning rolling members 58. The disk 14 is rotated in this manner until all or a substantial amount of the carbonized pitch is broken free from the disk 14 after which disk 14 is removed from the support rollers 10 for further conventional processing.
A second embodiment of the present invention is illustrated in
A third embodiment of the present invention is illustrated in
A fourth embodiment of the present invention is illustrated in
A method according to an embodiment of the present invention is illustrated in
The present invention has been described herein in terms of several presently preferred embodiments. Modifications and additions to these embodiments will become apparent to those of ordinary skill in the art upon reading of the foregoing description. It is intended that all modifications and additions to these embodiments form a part of the present invention to the extent they fall within the scope of the several claims appended hereto.