Wearable retracting animal leash

1. An extendable pet leash system configured to be worn on a pet collar, comprising:

a case selectively attachable to the pet collar;

an attachment mechanism that is affixed to the case and is configured to selectively attach and selectively detach the leash system to a pet collar;

a grip handle configured to mount on an exterior portion of the case;

a leash attached to the grip handle;

a leash spool having the leash coiled about it in a retracted state and comprising a spool spindle about which it rotates;

a thin coil negator spring that is free on one end to rotate and affixed on an other end to the leash spool, the negator spring configured to provide a rotational bias to the leash spool in a leash retraction direction;

a stop mechanism that when engaged prevents retraction of the leash and when engaged permits the leash to be extended; and

a stop release mechanism configured to disengage the stop mechanism and permit the leash to be retracted, the stop release mechanism being located at the case and remote from the grip handle.

2. The leash system according to claim 1 , wherein the attachment mechanism is a clip.

3. The leash system according to claim 2 , wherein the clip further comprises a clip ring configured to attach to a clip holder mounted on the case to secure the clip in a closed position.

4. The leash system according to claim 2 , wherein the clip and case comprise clip grip protrusions configured to grip the pet collar when the clip is in a closed position.

5. The leash system according to claim 1 , wherein the stop mechanism has a pointed end or corner configured to engage the leash spool.

6. The leash system according to claim 5 , wherein the leash spool is made of a relatively soft material so that the stop mechanism pointed end or corner can hold the leash spool against the bias of the negator spring.

7. The leash system according to claim 5 , wherein the leash spool comprises teeth that engage the pointed end or corner of the stop mechanism.

8. The leash system according to claim 5 , wherein the stop release mechanism comprises a button that is external to the case, and is configured to press against an end of the stop mechanism at an end opposite the pointed end or corner and on the other side of a stop pivot, configured such that when the button is pressed, the stop mechanism is disengaged from holding the leash spool.

9. The leash system according to claim 5 , further comprising a stop spring configured to bias the pointed end or corner against the leash spool.

10. The leash system according to claim 9 , wherein the stop spring is a compression spring.

11. An extendable pet leash system configured to be worn on a pet collar, comprising:

a case;

an attachment mechanism that is affixed to the case and is configured to attach the leash system to a pet collar;

a grip handle configured to mount on an exterior portion of the case;

a leash attached to the grip handle;

a leash spool having the leash coiled about it in a retracted state and comprising a spool spindle about which it rotates;

a thin coil negator spring that is free on one end to rotate and affixed on an other end to the leash spool, the negator spring configured to provide a rotational bias to the leash spool in a leash retraction direction;

a stop mechanism configured to permit the leash to be extended, but preventing the leash from retracting based on the bias of the negator spring;

a stop release mechanism configured to disengage the stop mechanism and permit the leash to be retracted;

wherein the attachment mechanism is a clip; and

wherein the clip comprises a pivot about which the clip rotates.

12. An extendable pet leash system configured to be worn on a pet collar, comprising:

a case selectively attachable to the pet collar;

an attachment mechanism that is affixed to the case and is configured to selectively attach and selectively detach the leash system to a pet collar;

a grip handle configured to mount on an exterior portion of the case having an outer portion that roughly approximates a case curvature, and an inner portion that has at least one grip curve configured to mate with a matching curve of the case thereby creating a gapless mating surface between the inner portion of the grip handle and the case when the leash is in a retracted position;

a leash attached to the grip handle;

a leash spool having the leash coiled about it in a retracted state and comprising a spool spindle about which it rotates;

a retracting bias mechanism configured to provide a retracting bias to the leash spool;

a stop mechanism that when engaged prevents retraction of the leash and when engaged permits the leash to be extended; and

a stop release mechanism configured to disengage the stop mechanism and permit the leash to be retracted, the stop release mechanism being located at the case and remote from the grip handle.

13. The leash system according to claim 12 , wherein the grip handle inner portion has two or more curves.

14. An extendable pet leash system configured to be worn on a pet collar, comprising:

a case;

an attachment mechanism that is affixed to the case and is configured to attach the leash system to a pet collar;

a grip handle configured to mount on an exterior portion of the case having an outer portion that roughly approximates a case curvature, and an inner portion that has at least one grip curve configured to mate with a matching curve of the case thereby creating a gapless mating surface between the inner portion of the grip handle and the case when the leash is in a retracted position;

a leash attached to the grip handle;

a leash spool having the leash coiled about it in a retracted state and comprising a spool spindle about which it rotates;

a retracting bias mechanism configured to provide a retracting bias to the leash spool;

a stop mechanism configured to permit the leash to be extended, but preventing the leash from retracting based on the bias of the retracting bias mechanism;

a stop release mechanism configured to disengage the stop mechanism and permit the lease to be retracted; and

wherein the case comprises a grip handle alignment mechanism, and the grip handle comprises a mating portion to hold the grip handle in alignment with the case when the leash is retracted.

15. The leash system according to claim 14 , wherein the alignment mechanism on the case comprises two or more protrusions; and the mating portion of the grip handle comprises mating holes configured to accept the protrusions and maintain alignment.

16. The leash system according to claim 14 , wherein the leash system is configured to fit within a box having the dimensions of 2″×3″×1.5″when the leash is in a retracted state.