Adhesively bonded rail joint
AssigneeMinnesota Mining and Manufacturing Company
InventorsAlfred Dwayne Nelson, Garold L. Goken
Life of this patent
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Abstract
Adhesively bonded rail joint which is quick to assemble and easy to dismantle and reassemble. The face of each joint bar of the rail joint has a layer of thermoplastic adhesive which upon moderate heating adheres strongly under moderate pressure to conforming surfaces of the rail ends. Because the thermoplastic adhesive does not cure, the joint bars are easily separated from the rails by reheating the adhesive and can be reapplied or used as part of a new rail joint.
Claims7
Adhesively bonded rail joint which is quick to assemble and easy to dismantle and reassemble comprising a pair of joint bars having broad faces shaped to conform to broad surfaces of the rails including at least major portions of the surfaces underlying the rail heads and the upper surfaces of the rail bases in the area of the rail joint, each of said broad faces carrying a thermoplastic adhesive layer about 10-60 mils in thickness and an adhesion-promoting coating of in-situ cured thermosetting resin between each thermoplastic adhesive layer and joint bar, which adhesive is characterized by:
- a. modulus in tension of at least 200,000 psi at all temperatures from -20.degree.F to 120.degree.F,
- b. tensile strength of at least 2000 psi at all temperatures from -20.degree.F to 120.degree.F,
- c. sufficiently low softening point that it wets steel at less than 500.degree.F under moderate pressure,
- d. shear adhesion to cold rolled steel of at least 2000 psi at all temperatures from -20.degree.F to 120.degree.F, and
- e. water absorption of less than 1 percent after 24-hour immersion.
Adhesively bonded rail joint which is quick to assemble and easy to dismantle and reassemble comprising a pair of joint bars each having broad faces shaped to conform to broad surfaces of the rails including at least major portions of the surfaces underlying the rail heads and the upper surfaces of the rail bases in the area of the rail joint, said broad faces carrying a thermoplastic adhesive layer about 25-50 mils in thickness, which adhesive is characterized by:
- a. modulus in tension of at least 200,000 psi at all temperatures from -20.degree.F to 120.degree.F,
- b. tensile strength of at least 3000 psi at all temperatures from -20.degree.F to 120.degree.F,
- c. sufficiently low softening point that it wets steel at 250.degree.-300.degree.F under moderate pressure,
- d. shear adhesion to cold rolled steel of at least 3000 psi at all temperatures from -20.degree.F to 120.degree.F, and
- e. water absorption of less than 1 percent after 24-hour immersion.
Dependencies are inferred from the claim text.