Fluid-operated servomotor

Claim 1

A servomotor, particularly a pneumatic servomotor for transmitting force to the master cylinder of a vehicle brake applying apparatus, comprising a cylinder including a first cover section having a cylindrical wall of uniform diameter throughout its length and a second cover section; a dished piston reciprocably accommodated in said cylinder; a rolling diaphragm having a central portion engaging said piston and an annular marginal portion sealingly engaging said cylinder, the maximum diameter of said diaphragm being equal to the internal diameter of said cylindrical wall; and an annular clamping member; means contained entirely within said cylinder for rigidly securing said annular clamping member to one of said sections to press the marginal portion of said diaphragm against the other section, said sections having adjacent annular portions and at least one of said annular portions being provided with bent-over projections overlying the other annular portion to thereby connect said sections to each other and to maintain said clamping member in engagement with said marginal portion, said marginal portion of said diaphragm being pressed against the connection of said adjacent annular portions.