Patent ID: 8695537

Claim:
A leash apparatus, comprising: (a) a housing containing, (i) a spool assembly, (ii) a lever arm, and (iii) a first tensioning line attached to a first end of the lever arm and wrapped at least once around the spool assembly, and having an opposite end attached to other than the rotatable portion of the spool assembly, wherein a surface of the spool assembly slidingly rotates relative to the tensioning line portion that wraps at least once around the spool assembly; and (b) a second tensioning line wound about the spool assembly and extending outside of the housing for attachment to a collar of harness of an animal, the second tensioning line being guided around a wheel attached to a second end of the lever arm located on an opposite side of the lever arm to the first end relative to a pivot axis of the lever arm; (c) wherein, upon a certain magnitude of acceleration in the unwinding of the second tensioning line from the spool, the lever arm pivots so as to pull on the first tensioning line, tightening the first tensioning line about the spool assembly and creating friction with the rotating movement of the spool assembly, thereby acting against the acceleration of the unwinding of the second tensioning line.