Patent assignee · US · COMPANY

ZefTek, Inc.

41Patents
1Active
41Granted
37Portfolio score

Filing activity: Jul 24, 1987 → Mar 22, 2006 · 1 expiring within 5 years

Most-cited patents

PatentTitleAreaCited byStatus
US5239933A Auto rack panel gap sealer and bumper Performing Operations; Transporting 37 Expired
US5145076A Plastic knuckle pin with annular relief grooves for preventing pin failure due to fatigue Performing Operations; Transporting 33 Expired
US6926480B2 Supplemental restraint for auto-rack railroad car restraint system Performing Operations; Transporting 33 Expired
US5669745A Bumper system for an intermodal auto trailer Performing Operations; Transporting 31 Expired
US7128508B2 Supplemental restraint for auto-rack railroad car restraint system Performing Operations; Transporting 30 Expired
US4917021A Door finger guide for doors on auto rack cars Performing Operations; Transporting 28 Expired
US5579697A Auto rack panel gap sealing device Emerging Cross-Sectional Technologies 28 Expired
US6050199A Hatch cover sealing device Performing Operations; Transporting 27 Expired
US5960980A Vented hatch cover Emerging Cross-Sectional Technologies 27 Expired
US5630519A Plastic knuckle pin Performing Operations; Transporting 26 Expired
US7150592B2 Supplemental restraint for auto-rack railroad car restraint system Performing Operations; Transporting 24 Expired
US5415108A Auto rack panel gap sealer Performing Operations; Transporting 23 Expired
US6561740B1 Auto rack railroad car panel bumper guard Performing Operations; Transporting 23 Expired
US7004696B2 Supplemental restraint for auto-rack railroad car restraint system Performing Operations; Transporting 22 Expired
US5701825A Gap closing device for closing side wall gaps in auto rack cars Performing Operations; Transporting 20 Expired
US5924654A Railroad car sensing system Performing Operations; Transporting 20 Expired
US4784068A Segmented sliding sill wear plate Performing Operations; Transporting 19 Expired
US4913062A Segmented sliding sill wear plate Performing Operations; Transporting 19 Expired
US6708625B1 Greaseless door lock Emerging Cross-Sectional Technologies 18 Expired
US6553917B1 Auto rack railroad car bumper guard device Performing Operations; Transporting 18 Expired
US5694859A Hole covering device for an auto rack car side wall panel Emerging Cross-Sectional Technologies 15 Expired
US5682964A Brake beam wear plate Performing Operations; Transporting 14 Expired
US5975818A Grating lift pad Performing Operations; Transporting 13 Expired
US5598936A Coupler carrier wear plate for long-shank couplers Performing Operations; Transporting 12 Expired
US6367590B1 Cushioned brake beam wear plate Performing Operations; Transporting 12 Expired

Source: USPTO / EPO open patent data. Counts and citation impact are objective bibliographic measures.