Diaphragm-type pumping apparatus

A diaphragm-type pumping apparatus comprising:

• a pair of disc-like diaphragms, each having a diaphragm section for defining a fluid delivering chamber and a working fluid chamber;
• a main body section operatively supporting a center rod so as to allow a reciprocating motion thereof, said pair of diaphragms being attached at central portions thereof to respective ends of said center rod;
• and
• a pair of casing members arranged so as to hold said main body section from opposite sides thereof and functioning in association with said main body section to clamp peripheral portions of said respective diaphragms from opposite sides along a thickness direction thereof, wherein a fluid is sucked through a fluid suction port and discharged from a fluid discharge port by reciprocating said center rod in response to a change-over in supplying a working fluid to said respective working fluid chambers,
• wherein at least one of said casing members is made of Teflon (registered trademark), and each of said diaphragms has an annular lip section formed in an outer circumferential portion that is outside of the peripheral portion thereof, and said annular lip section extends along a direction of the reciprocating motion of said center rod and also along a thickness direction of the respective diaphragm,
• wherein said main body section is provided with annular wall sections at opposite sides thereof, and said annular wall sections define annular recesses for accommodating an ingress of said annular lip sections, respectively, and
• wherein an outer surface of each of said annular wall sections is provided with a threaded section, and annular threaded members are engaged with said threaded sections, respectively, for compressing said annular lip sections toward clamping portions between said main body section and said casing member.

A diaphragm-type pumping apparatus comprising:

• a pair of disc-like diaphragms, each having a diaphragm section for defining a fluid delivering chamber and a working fluid chamber;
• a main body section operatively supporting a center rod so as to allow a reciprocating motion thereof, said pair of diaphragms being attached at central portions thereof to respective ends of said center rod;
• a pair of casing members arranged so as to hold said main body section from opposite sides thereof and functioning in association with said main body section to clamp peripheral portions of said respective diaphragms from opposite sides along a thickness direction thereof, wherein a fluid can be sucked through a fluid suction port and discharged from a fluid discharge port by reciprocating said center rod in response to a change-over in supplying a working fluid to said respective working fluid chambers, wherein at least one of said casing members is made of Teflon (registered trademark),
• wherein each of said diaphragms has an annular lip section formed in an outer circumferential portion thereof and said annular lip section extends along a direction of a reciprocating motion of said center rod and also along a thickness direction of the corresponding diaphragm,
• wherein said casing members or said opposite sides of said main body section are provided with annular wall sections, respectively, and each of said annular wall sections forms an annular recess for accommodating said annular lip section of said respective diaphragm, wherein each of said diaphragms has a cylinder section formed in a central portion thereof, and each of said cylinder sections includes an inner threaded section formed on an inner surface thereof, and an outer threaded section formed on an outer surface thereof, and
• wherein said inner threaded sections are engaged with threaded sections of said center rod, respectively;
• and
• a pair of reinforcing ring members engaged with said outer threaded sections of said cylinder sections, respectively, so as to clamp said cylinder sections in association with said center rod.