Shock Resistant Tether

Abstract

A shock absorbing tether comprising an elongated flexible primary strand which is surrounded by a longitudinally elastic casing having terminal ends and which is attached to the primary strand at each of its terminal ends and at at least one point intermediate the terminal ends.

Claims

1. A shock absorbing tether comprising, an elongated flexible strand, a longitudinally elastic casing having terminal ends and surrounding the strand and attached to the strand at each of its terminal ends and at at least one point intermediate the terminal ends.

2. The tether of claim 1 where the strand has first and second ends and the terminal ends of the casing are attached to the strand proximate its first and second ends,

3. The tether of claim 2 and further comprising, a fastener connected to the first end of the strand, and a handgrip proximate the second end of the strand.

4. The tether of claim 3 where the handgrip comprises a loop formed by the flexible member folded back upon itself, the second end being secured to the strand.

5. A shock absorbing tether comprising, an elongated strand having first and second ends, a longitudinally elastic casing having terminal ends and surrounding the strand where the terminal ends of the casing are attached to the strand proximate its first and second ends and the casing is attached to the strand at at least one point intermediate the terminal ends of the casing, a fastener connected to the first end of the strand, and a handgrip proximate the second end of the strand comprising a loop formed by the tether folded back upon itself where the second end is secured to the tether.

6. A shock absorbing tether comprising, an elongated strand having first and second ends, a longitudinally elastic casing having terminal ends and surrounding the flexible member where the terminal ends of the casing are attached to the strand intermediate its first and second ends and the casing is attached to the flexible member at at least one point intermediate the terminal ends of the casing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIG. 1 is a side view of a tether, such as an animal leash, that incorporates the elements of the present invention, including an interior strand encased by a tubular elastic casing. The drawing shows the intermediate anchor points between sections of the leash where the elastic casing surrounding the strand is sewn or otherwise attached to the strand, the length of each section between the intermediate anchor points being denominated as X.sub.1 and X.sub.2.

[0010] FIG. 2 is an enlarged fragmentary longitudinal cross sectional view of two sections of the tether showing the hand of a handler griping the exterior casing of the tether at a distance from the closest anchor point that attaches the exterior casing to the interior strand.

[0011] FIG. 3 is an enlarged fragmentary longitudinal cross sectional view of section X.sub.1 showing a tension force F being applied to the strand to move it toward the source of the application of the force while the hand of the handler remains in a relatively constant position.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

[0012] FIG. 1 depicts the preferred form of the present invention as an animal leash 4. However, the invention may be applied to any elongated strand that constitutes a tether and which is being handled or manipulated and for which it is desired to provide shock absorption to the handler. The elongated strand 6 forming the interior of the leash may be a woven web or equivalent (“web”). In other applications the strand may be rope, cord, cable or the like. In the illustrated embodiment the web 6 is encased by a longitudinally elastic casing 8 whose terminal ends 10 and 12 are sewn to or otherwise secured to the web 6. The casing 8 is also secured to the interior web at intermediate points 15 between the terminal ends of the casing. The sections of the tether 4 between the intermediate points of attachment 15 are referred to in FIGS. 1 and 2 as X.sub.1 and X.sub.2. A handle 18 is formed by a loop of the distal end of the tether folded back upon itself and attached to the tether 4.

[0013] The event of the handler controlling the tether 4 by grasping it below the handle 18 is depicted in FIG. 2 which also shows in cross section the web 6 inside of the tubular elastic casing 8 with two intermediate anchor points 15 that secure the casing to the web 6. The length of the sections X.sub.1, X.sub.2or X.sub.n depends on the type of elastic material comprising the casing and the total length of the tether and the casing. The length of the sections can vary from one foot to several feet. The elastic material is preferably Spandex, Lycra or similar synthetic material.

[0014] FIG. 3 illustrates the action of the shock absorbing function of the present invention. The hand 20 of the handler grips the casing 8 at a point below the handle 18. Force F is applied to the web, for example through a fastener 5 that may be connected to an animal collar or harness or other force producing agent. The force F tends to move the web 6 in the direction of the force arrow F. In the illustrated example of FIG. 3, the force F moves the anchor point 15a toward the point of force application which applies a stretching force to the casing 8 that is above the anchor point 15a. The casing above the anchor point 15a is held in place by the hand 20 which remains in a relatively constant position, achieving the shock absorption result from the stretched length Y of the elastic casing.

[0015] The benefit of the intermediate attachment points 15 results from those points shortening the distance between the hand of the handler and the point from which the stretching force on the casing occurs. Shortening this distance provides maximum stretching of the casing relative to the strand and consequent maximum shock resistance. A given stretching force on the elastic casing is absorbed over the whole length of the casing to which the force is applied. Therefore, long distances between the hand and the anchor point result is less stretch of the casing relative to the strand. The intermediate attachment points shorten the distance between the anchor point of the casing and the position of the hand, resulting in greater stretch of the casing for a given force and consequently greater shock absorption.