Patent ID: 9470316
Filing Date: 2016-10-18
CPC Classification: B29C,B29L,F16F,F16J

Claim Text:
1. A protective cover being of a tubular shape and including a bellows portion wherein a plurality of valleys outwardly concave and a plurality of peaks outwardly convex are arranged in an alternating sequence, wherein the valleys of the bellows portion comprise a plurality of large valleys and a plurality of intermediate valleys whose inside and outside diameter dimensions at bottoms are greater than an outside diameter dimension at bottoms of the large valleys, and the large valleys and the intermediate valleys are arranged in an alternating sequence, small valleys whose inside and outside diameter dimensions at bottoms are greater than the outside diameter dimension at bottoms of the intermediate valleys are respectively arranged between the large valleys and the intermediate valleys, the peaks are respectively arranged between the large valleys and the small valleys as well as between the intermediate valleys and the small valleys, and apexes of the peaks have a same outside diameter dimension as one another, and the apexes of the peaks have a thickness dimension in an axis perpendicular direction that is smaller than a thickness dimension in the axis perpendicular direction of the bottoms of the large valleys, the differential between the outside diameter dimension at the apexes of the peaks and the outside diameter dimension at the bottoms of the intermediate valleys is not less than two-thirds of the differential between the outside diameter dimension at the apexes of the peaks and the inside diameter dimension at the bottoms of the large valleys, and the differential between the outside diameter dimension at the apexes of the peaks and the inside diameter dimension at the bottoms of the small valleys is not more than one-third of the differential between the outside diameter dimension at the apexes of the peaks and the inside diameter dimension at the bottoms of the large valleys.