Die cut disposable grounding wrist strap
AssigneeMinnesota Mining and Manufacturing Company
InventorDonald E. Klepel
Life of this patent
Estimating the term…
Abstract
An inexpensive grounding wrist strap and tether for draining excess electrostatic charge, which may be used once and then disposed. The strap and tether are formed integrally and include a conductive strip having a discrete resistance portion for safety considerations. The discrete resistance portion is formed by making a zig-zag pattern of cuts in the conductive strip, thereby increasing the length of the current path through the discrete resistance portion. Due to the slight resistivity of the conductive strip, the lengthened current path results in a discrete resistance being built into the strip. The cuts may be made in the strip at the same time the strip is fashioned out of a sheet of the conductive material, such as carbon loaded polyethylene.
Claims18
A grounding tether for draining excess electrostatic charge from an object, comprising:
- a strip of conductive material having upper and lower surfaces, distal and proximate ends, and having a discrete resistance portion formed by a plurality of cuts which essentially extend through the entire thickness of said strip;
- said cuts effectively increase the length of the electrical current path through said discrete resistance portion;
- means for attaching said distal end of said strip to an electrical ground;
- and
- means for affixing said proximate end of said strip to the object.
An integral wrist strap and grounding tether for draining excess electrostatic charge from a user, comprising:
- a strip of conductive material having upper and lower surfaces, distal and proximate ends, and having a discrete resistance portion formed by a plurality of cuts which essentially extend through the entire thickness of said strip, said plurality of cuts forming a zig-zag pattern;
- a first insulative tape having a width greater than the width of said strip of conductive material, and having an adhesive layer in contact with said lower surface of said strip of conductive material;
- a second insulative tape having a width greater than the width of said strip of conductive material, disposed adjacent said upper surface of said strip of conductive material and in partial contact with said adhesive layer of said first insulative tape, said second insulative tape not fully extending to said proximate end of said strip of conductive material, whereby an exposed portion of said adhesive layer may be used to affix said proximate end of said strip to the wrist of the user;
- and
- means for attached said distal end of said strip to an electrical ground.
A method of manufacturing an integral wrist strap and grounding tether for draining excess electrostatic charge from a user, comprising the steps of:
- obtaining a sheet of conductive material having a volume resistivity in the range of 50 to 500 ohms-centimeters;
- and
- cutting a strip from said sheet and simultaneously creating a discrete resistance portion in said strip by making a plurality of cuts in said strip, said cuts forming a zig-zag pattern whereby the electrical current path through said discrete resistance portion is effectively lengthened.
Dependencies are inferred from the claim text.