Patent ID: 7775528

Claim:
A bi-directional seal for sealing against a shaft, comprising: a lay down lip having a leading seal edge and an active surface for engaging the shaft, said active surface including an annular circumferential groove extending into said active surface away from the shaft and a plurality of angular grooves extending into said active surface away from the shaft, said plurality of angular grooves extending from said annular circumferential groove toward a liquid side of the seal, said circumferential groove being at a substantially constant distance from said leading seal edge as said circumferential groove extends annularly, said plurality of angular grooves including a repeating pattern of angular grooves with each pattern having a plurality of immediately adjacent angular grooves with a positive approach angle without grooves having a negative approach angle therebetween and a plurality of immediately adjacent angular grooves with a negative approach angle without grooves having a positive approach angle therebetween, wherein within each pattern of angular grooves said plurality of grooves with a positive approach angle and said plurality of grooves with a negative approach angle approach one another as said grooves extend toward said annular circumferential groove.