The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 29, 2001
Filed:
Jul. 28, 1998
Harry B. Kalina, Arlington, TX (US);
Charles T. Bomgardner, Burleson, TX (US);
Richard N. Hodges, Arlington, TX (US);
FM Industries, Inc., Fort Worth, TX (US);
Abstract
A cushioning device for a railcar coupling that operates at a very high impedance when subjected to low level forces to thereby reduce the effect of slack between railcars while still providing an effective cushion for absorbing high levels of shock between the railcars. The cushioning device includes a cylinder containing a fluid of liquid and a gas under pressure for absorbing shock due to buff and draft movement and a piston carried in the cylinder. The gas pressure urges the piston toward the draft end of the cylinder while restoring from a buff shock. An internal positioning spring stops further restoring movement of the piston toward the draft end of the cylinder at a selected neutral position spaced from the draft end of the cylinder. The internal positioning spring allows the piston to move from the neutral position toward the draft end of the cylinder if a draft shock occurs of sufficient magnitude while the piston is in the neutral position.