| 摘要 |
Elongated, flexible teat cup liners (10) of improved design are provided which can accommodate teats of varying lengths without fear of teat damage or inefficient machine milking. The liners (10) of the invention include an apertured mouthpiece (12) adjacent one end thereof, with an elongated, intermediate barrel (14) presenting an inwardly collapsible teat-receiving region and a lowermost connecting tube (16) adapted for connection to a constant vacuum source. The liners (10) of the invention also include structure (18) for creating a differential resistance to inward collapse of the teat-receiving region of barrel (14) along the length thereof. The structure (18) assures a relatively high resistance to inward collapse at a first location (34) adjacent mouthpiece (12), and a gradual and progressive decrease in such resistance to inward collapse along an axial length of the teat-receiving region of barrel (14). Advantageously, the axial length of the teat-receiving region having the desired gradual and progressive decrease in resistance to inward collapse is at least three times greater than the maximum internal diameter of the teat-receiving region. The structure (18) may take the form of integral, circumferentially extending, axially spaced apart ribs (36) of differential mass, constant mass circumferential ribs (38) which are differentially spaced, a helical rib (40) of increasing pitch, or external, circumferentially spaced ribs (44) of decreasing mass from top to bottom.
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