Breast pump and cap for same

A cap for use in a breast pump for expressing human breast milk, the breastpump having a motor-driven flexible pump diaphragm, wherein the cap is rigid and is configured to be put over the flexible pump diaphragm, whereby a pump chamber for generating a negative pressure is formed between the pump diaphragm and the cap, the cap being connectable or connected via a suction line to a breast shield unit, and the negative pressure generated in the pump chamber being transferrable into the breast shield unit, the pump diaphragm having a circumferential collar with a step and having a laterally projecting protrusion, and the cap having, on the inner side thereof, a circumferential bearing region, wherein the cap has, on the inner side thereof, at least one form-fit element, which is arranged at a distance from the circumferential bearing region and which together with the protrusion of the pump diaphragm forms a form fit, whereby the cap rests on the pump diaphragm in a manner snapped into place, and wherein the circumferential bearing region of the cap and the pump diaphragm in the region of the step are involved in a joint frictional connection and form a seal, such that the resting of the cap on the pump diaphragm in a manner snapped into place is sufficient to hold the cap in a sealing manner on the pump diaphragm, the at least one form-fit element being designed as a snap-fit element and the at least one form-fit element being formed by an inwardly directed bead.

A breast pump for expressing human breast milk having a motor-driven flexible pump diaphragm and a rigid cap that is configured to be put over the flexible pump diaphragm, whereby a pump chamber for generating a negative pressure is formed between the pump diaphragm and the cap, the cap being connectable or connected via a suction line to a breast shield unit, and the negative pressure generated in the pump chamber being transferrable into the breast shield unit, the pump diaphragm having a circumferential collar with a step and having a laterally projecting protrusion, and the cap having, on the inner side thereof, a circumferential bearing region,

• wherein the cap has, on the inner side thereof, at least one form-fit element, which is arranged at a distance from the circumferential bearing region and which together with the protrusion of the pump diaphragm forms a form fit, whereby the cap rests on the pump diaphragm in a manner snapped into place, and wherein the circumferential bearing region of the cap and the pump diaphragm in the region of the step are involved in a joint frictional connection and form a seal, such that the resting of the cap on the pump diaphragm in a manner snapped into place is sufficient to hold the cap in a sealing manner on the pump diaphragm, wherein a circumferential channel is formed between the circumferential bearing region and the at least one form-fit element, surrounding the collar of the pump diaphragm and receiving the protrusion.