Patent ID: 11864943
Assignee: 3M INNOVATIVE PROPERTIES COMPANY
Field: Materials, metallurgy (Chemistry)
Classification: CPC A  B  G | IPC A  B  G

Claim 14:
15. The method of claim 13, wherein the mould comprises a negative forming:
a body member having a first generally bell-shaped recess with an inner central portion, an outer rim portion and a bore extending through the body member communicating with the central portion of the first recess;
immobilizing means situated on the body member and located within the first ecess at about the central portion, the immobilizing means adapted to be contacted by a diaphragm when the diaphragm is in an inner position so that a stethoscope chestpiece will pass low frequency sounds and attenuate high frequency sounds when the diaphragm is in the outer position and between the outer and inner positions, and when the diaphragm is in the inner position the acoustical stiffness of the diaphragm will be sufficiently higher than the first acoustical stiffness so that the stethoscope chestpiece will pass high frequency sounds and attenuate low frequency sounds.