Claims
1. A flange component (36, 80,100) for a spring brake actuator (30) comprising a
service brake part (32) and a parking brake part (34), wherein
the flange component (36,80,100) comprises a side wall (60,86,106), a center wall (62, 88,107), a first flange lip (56, 82, 102) for connecting the flange component (36, 80,100) with the service brake part (32) and a second flange lip (58, 84,104) for connecting the flange component (36, 80,100) with the parking brake part (34),
characterized in that
the side wall (60, 86, 106) comprises depressions (66, 68, 66', 68', 92, 94) re-ducing a wall thickness of the side wall (60, 86,106).
2. The flange component (36, 80, 100) of claim 1, wherein the side wall (60, 86, 106) comprises a multitude of depressions (66, 68, 66', 68', 92, 94) separated by ribs (70, 72, 74, 70*. 72', 74', 96, 97, 98).
3. The flange component (36, 80, 100) of claim 2, wherein a wall thickness of the depressions (66, 68, 66', 68', 92, 94) is reduced with regard to a wall thickness of the ribs (70, 72, 74, 70', 72', 74', 96, 97, 98).
4. The flange component (36,80,100) of claim 2 or 3, wherein the ribs (70,72,74, 70*, 72', 74', 96, 97, 98) are stiffening ribs (70, 72, 74, 70', 72', 74', 96, 97, 98).

5. The flange component (36, 80, 100) of one of claims 2 to 4, wherein the ribs (70, 72, 74, 70', 72', 74', 96, 97, 98) have a uniform wall thickness.
6. The flange component (36, 80,100) of one of the preceding claims, wherein the depressions (66, 68, 66', 68', 92, 94) have a square, a rectangular, a triangular, a circular or a hexagonal like form.
7. The flange'component (36, 80,100) of one of the preceding claims, wherein the side wall (60, 86, 106) includes a first wall part (64, 90, 108) and a second wall part (64', 90', 108'), the first wall part (64, 90, 108) being connected with the first flange lip (56, 82,102) and the second wall part (64', 90', 108') being connected with the second flange lip (58, 84, 104), wherein the first wall part (64, 90, 108) is separated from the second wall part (64\ 90", 108') by the center wall (62, 88,107), and wherein the first wall part (64, 90,108) and/or the second wall part (64', 90', 108') comprise a multitude of depressions (66, 68, 66', 68', 92, 94) constituting a honeycomb-like structure.

8. The flange component (36, 80, 100) of claim 7, wherein the first wall part (64, 90, 108) and/or the second wall part (64', 90', 108') comprise a first multitude of rec¬tangular depressions (66, 66', 92) constituting a first row and a second multitude of rectangular depressions (68, 68', 94) constituting a second row, and wherein the de¬pressions (66,66', 92) of the first row are separated from the depressions (68,68', 94) of the second row by ribs (74, 74', 98).
9. The flange component (36, 80, 100) of one of the preceding claims, wherein each flange lip (56, 58, 82, 84, 102, 104) comprises a sealing side (114, 118) and a clamping side (116,120), and wherein one or both clamping sides (116,120) comprise a multitude of recesses (110,112).
10. The flange component (36, 80,100) of claim 9, wherein the recesses (110,112) are groove-like indentations reducing a thickness of a respective flange lip (56, 58, 82, 84,102,104).
11. The flange component (36, 80,100) of claim 9 or 10, wherein the recesses (110, 112) have a same circumferential width, and wherein each recess (110,112) is sepa-rated from a neighboring recess (110,112) by a plateau having a circumferential width corresponding with the circumferential width of the recesses (110,112).
12. A spring brake actuator (30) comprising a flange component (36, 80, 100) ac¬cording to one of the preceding claims.
13. The spring brake actuator (30) of claim 12, comprising a service brake part (32), a parking brake part (34) and a push rod (42), wherein the service brake part (32) comprises a service brake cover (38), a diaphragm, and a service chamber for provid¬ing a service brake function, and wherein the parking brake part (34) comprises a park¬ing brake cover (40), a ram assembly, a parking chamber and a compression spring for providing a parking brake function and an emergency brake function.
14. The spring brake actuator (30) of claim 12 or 13, wherein the spring brake ac¬tuator (30) is a component of a compressed air brake system of a commercial vehicle.
15. A commercial vehicle comprising a spring brake actuator (30) according to one
of the preceding claims 12 to 14.