Diaphragm type pressure sensor

A pressure sensor comprising:

• a plate-shaped diaphragm having a periphery, an inner side, and an outer side;
• a transducing element mounted on said outer side of said diaphragm for sensing deflection of said diaphragm;
• a diaphragm support having a diameter and comprising a top end supporting the periphery of said diaphragm, a bottom end, and a cylindrical outside surface extending from said top end to said bottom end;
• and
• a trunk comprising a first cylindrical portion having a diameter and forming a first annular step and a second cylindrical portion having a diameter and forming a second annular step surrounding said first annular step, said first cylindrical portion having a diameter larger than the diameter of said diaphragm support and smaller than the diameter of said second cylindrical portion, said diaphragm support and said first and second cylindrical portions being coaxial, said first cylindrical portion extending from said bottom end of said diaphragm support to said second cylindrical, the difference between the diameter of said diaphragm support and the diameter of said first cylindrical portion being at least equal to the difference between the diameter of said first cylindrical portion and the diameter of said second cylindrical portion, said diaphragm support being disposed on said first annular step, said trunk and said diaphragm support comprising a jointless transducer main body.

A pressure sensor comprising:

• a transducer main body comprising a plate-shaped diaphragm having an inner side and an outer side, a mounting portion for mounting to a container for a fluid, a cylindrical diaphragm support having a top end supporting a periphery of said diaphragm, a trunk extending between said mounting portion and said diaphragm support and comprising a first cylindrical portion and a second cylindrical portion, the first cylindrical portion being disposed between said diaphragm support and said second cylindrical portion and having a smaller diameter than said second cylindrical portion and a larger diameter than said diaphragm support, and a hole of constant cross-section in said diaphragm support and said trunk and communicating with said inner side of said diaphragm for introducing a fluid from said container to said inner side of said diaphragm;
• a transducing element for sensing deflection of said diaphragm affixed to the outer side of said diaphragm;
• and
• a cover for protecting said transducing element, said cover being fitted over said first cylindrical portion, wherein the difference between the diameter of said first cylindrical portion and the diameter of said diaphragm support is at least equal to the difference between the diameter of said second cylindrical portion and the diameter of said first cylindrical portion.

A pressure transducer comprising:

• a trunk comprising a first cylindrical portion having a top end and a bottom end and a constant diameter, a second cylindrical portion coaxial with the first cylindrical portion and having a constant diameter larger than the diameter of the first cylindrical portion and having a top end and a bottom end, the bottom end of the first cylindrical portion being integral with the top end of the second cylindrical portion;
• a cylindrical diaphragm support coaxial with the first cylindrical portion and having a constant diameter smaller than the diameter of the first cylindrical portion and having a top end and a bottom end integral with the top end of the first cylindrical support, the difference between the diameter of the diaphragm support and the diameter of the first cylindrical portion of the trunk being greater than or equal to the difference between the diameters of the first and second cylindrical portions of the trunk;
• a plate-shaped diaphragm having an inner surface, an outer surface, and a periphery surrounded by the diaphragm support, the diaphragm being integral with the top end of the diaphragm support, wherein the trunk, the diaphragm support, and the diaphragm comprise a jointless body;
• a transducing element mounted on the outer surface of the diaphragm;
• a mounting portion secured to the trunk for mounting the trunk on a container for a fluid;
• a passage for fluid between an external surface of the mounting portion and the inner surface of the diaphragm;
• and
• a cover having an end surrounding the first cylindrical portion and abutting against the top end of the second cylindrical portion of the trunk.