US Patent 6845736 Retractable tether for animals

A retractable animal tether, comprising a hand-held support; a spool rotatably mounted on the support; and a flexible cord wound on the spool, said flexible cord having an end which is connected to the spool and a second end which may be connected with the animal. The application of a first force F1 to a free end of the flexible cord causes a portion of the flexible cord to unwind from the spool. The tether also includes a means for preventing the remainder of the flexible cord from unwinding from the spool unless a second force F2 is applied to the free end of the flexible cord, said force F2 being greater than said force F1.