Patent ID: 8726938

Claim:
A membrane valve for inhalation devices, comprising: a planar membrane made of permanently flexible material having a fastening opening disposed in a center of the membrane; a frame having an air opening that is smaller than the membrane; a retainer that is arranged at a center of the air opening, the retainer having a retaining opening; at least one web that connects the frame with the retainer; and a pin having a shaft that extends through the fastening opening in the center of the membrane, the shaft having a first portion located within the retaining opening in the retainer and a second portion located within the fastening opening, wherein the membrane has an inner portion facing the frame and an outer portion opposite to the inner portion and more distant from the frame, the pin widens into a head such that a spacing from the head to the membrane is smaller than a thickness of the membrane, or the head lies on the membrane, a diameter of the second portion of the shaft located closest to the inner portion of the membrane is a first diameter, and a diameter of the second portion of the shaft located closest to the outer portion of the membrane is a second diameter larger than the first diameter, and the second diameter is greater than a diameter of the fastening opening, and the first diameter is approximately equal to the diameter of the fastening opening such that the outer portion of the membrane is pressed apart by an enlarged diameter of the shaft near the outer portion of the membrane, and an inner portion of the membrane remains unloaded, such that the membrane is bulged adjacent to the fastening opening in the center of the membrane.