Safety tether for pipe end prep tool
A safety tether is provided for securing a heavy work tool. The safety tether includes one or more springs that serve to carry some of the weight of the work tool. A safety chain is provided in parallel connection with the springs. The length of the chain is less than the extended length of a spring at its maximum rated load, thus precluding extension of the springs to that link, greatly reducing any likelihood that the springs will break. In the event of spring breakage, the chain serves as a safety chain, stopping the tool from falling.
1. A safety tether, comprising:
first and second end brackets;
at least one expandable spring having a characteristic maximum load rating and interconnected between said first and second end brackets;
a safety chain interconnected between said first and second end brackets in parallel with said at least one spring, said chain having an extended length less than a length of said at least one spring when extended to a predetermined limit correlated with said characteristic maximum load rating of said at least one spring; and
wherein said chain comprises a plurality of interconnected links, an end link at each end of said chain being captured by one of said first and second end brackets, and each of said end brackets has a cavity therein receiving an associated said end link, said cavity interconnecting with a first slot to an edge of said end bracket.
2. The safety tether according to claim 1 , wherein said first end bracket has an aperture to accommodate secured engagement to a tool, and said second end bracket has an aperture to accommodate secured engagement to an elevated support member.
3. The safety tether according to claim 1 , further comprising a chain retainer plate welded to said associated end bracket over said cavity, thereby capturing said end link within said cavity.
4. The safety tether according to claim 3 , wherein said chain retainer plate has a second slot therein extending from an edge of said chain retainer plate, said first and second slots being in alignment and receiving a second link of said chain extending from said end link, said second link passing through said slots and beyond an edge of said associated end bracket.
5. The safety tether according to claim 4 , wherein said second link passes sufficiently beyond said edge of said associated bracket to receive a third link without interference with said associated bracket.
6. The combination of a tool and safety tether, comprising:
a tool;
a first end bracket secured to said tool;
a second end bracket secured to a stationary member;
at least one weight bearing spring extending between said first and second end brackets; and
a tether extending between said first and second end brackets in parallel with said weight bearing spring, said tether being of a length less than a characteristic extended length of said weight bearing spring at a maximum load bearing extension of said weight bearing spring, and wherein said tether is securedly received by said first and second end brackets at opposite ends thereof, said tether being a link chain, an end link at each end of said chain being captured by a respective one of said end brackets, and each said end bracket having a cavity therein receiving said end link, said cavity being capped by a chain retainer plate.
7. The combination according to claim 6 , wherein said tool has an attachment bracket with apertures therein for secured attachment to said first end bracket.
8. The combination according to claim 6 , wherein said end brackets and chain retainer plates have slots passing through edges thereof and into communication with an associated said cavity, said slots receiving a second link from an associated end of said chain.
9. The combination according to claim 8 , wherein the links of said chain are not cut, abraded, welded or mechanically disturbed.