Patent ID: 7997842

Claim:
A replaceable cartridge system for a vehicle, comprising an air-dryer cartridge having a female thread threadably engageable with a mount having a male thread, said female and male threads each including thread flights, said thread flights of said female thread being formed from a first material having a strength different than that of a second material forming said thread flights of said male thread, said thread flights of said female thread having cross-sectional surfaces smaller than cross-sectional areas of gaps therebetween, and said thread flights of said male thread having cross-sectional surfaces larger than cross-sectional areas of gaps therebetween, wherein opposing flanks of said thread flights of said female thread have unequal angles relative to a line orthogonal to a longitudinal axis of said female thread, wherein a flank of said female thread brought into bearing relationship with a flank of said male thread when said female and male threads are in tightened threaded engagement defines an angle of larger absolute value relative to said line orthogonal to a longitudinal axis of said female thread than does an opposing flank of said female thread, and wherein said flanks of said female and male threads brought into bearing relationship with one another when said female and male threads are in tightened threaded engagement have line contact.