Von Duprin LLC
74Patents
6Active
74Granted
37Portfolio score
Filing activity: Jul 24, 1978 → Jun 13, 2012 · 4 expiring within 5 years
Most-cited patents
| Patent | Title | Area | Cited by | Status |
|---|---|---|---|---|
| US4305612A | Apparatus for operating a door latching and unlatching device | Emerging Cross-Sectional Technologies | 54 | Expired |
| US4601499A | Operating mechanism for a closure latching assembly | Emerging Cross-Sectional Technologies | 49 | Expired |
| US5184855A | Electromagnetic door lock assembly | Emerging Cross-Sectional Technologies | 48 | Expired |
| US5412961A | Exit delaying mechanism for panic exit door | Emerging Cross-Sectional Technologies | 46 | Expired |
| US5011199A | Panic exit device having an exit-delaying mechanism | Emerging Cross-Sectional Technologies | 45 | Expired |
| US5085475A | Exit-delaying mechanism, for a panic exit device | Emerging Cross-Sectional Technologies | 44 | Expired |
| US5464259A | Door latch assembly with meltable fuse mechanism | Emerging Cross-Sectional Technologies | 43 | Expired |
| US5658026A | Door handle locking mechanism with dual function springs | Emerging Cross-Sectional Technologies | 41 | Expired |
| US4628496A | Ultrasonic sensing and monitoring systems | Fixed Constructions | 38 | Expired |
| US4741563A | Center case assembly, and a universal, center case sub-assembly | Emerging Cross-Sectional Technologies | 38 | Expired |
| US5927765A | Dogging device for a latch assembly | Emerging Cross-Sectional Technologies | 33 | Expired |
| US5520427A | Breakaway lever with wedge release mechanism | Emerging Cross-Sectional Technologies | 26 | Expired |
| US5067757A | Panic exit device having noise suppression | Emerging Cross-Sectional Technologies | 26 | Expired |
| US4427223A | Latching device | Emerging Cross-Sectional Technologies | 26 | Expired |
| US5450697A | Removable cylinder locked mullion assembly | Emerging Cross-Sectional Technologies | 22 | Expired |
| US4847950A | Self retained axle pin assembly for shear application | Emerging Cross-Sectional Technologies | 22 | Expired |
| US7616090B2 | Electronic security system | Electricity | 21 | Expired |
| US4949505A | Door cordinator | Fixed Constructions | 21 | Expired |
| US5035450A | Door exit-delaying means | Emerging Cross-Sectional Technologies | 21 | Expired |
| US6595563B2 | Electric strike field-selectable fail-safe/fail-secure mechanism | Emerging Cross-Sectional Technologies | 20 | Expired |
| US5372394A | Pneumatic controlled exit device | Emerging Cross-Sectional Technologies | 20 | Expired |
| US8182003B2 | Exit device and method of operating the same | Emerging Cross-Sectional Technologies | 19 | Active |
| US4437693A | Thermally responsive latching device and method of modifying a latching device | Emerging Cross-Sectional Technologies | 19 | Expired |
| US5484179A | Failsafe electric locking lever trim | Emerging Cross-Sectional Technologies | 18 | Expired |
| US4658664A | Rack and pinion assembly | Emerging Cross-Sectional Technologies | 17 | Expired |
Source: USPTO / EPO open patent data. Counts and citation impact are objective bibliographic measures.