David Ladd
24Patents
10h-index
20Co-inventors
75Inventor score
Filing activity: May 6, 1985 → Jun 23, 2023
Most-cited inventions
| Patent | Title | Area | Cited by | Status |
|---|---|---|---|---|
| US4926462A | Interface to and operation of a voice messaging system | Electricity | 140 | Expired |
| US4783796A | PBX telephone call control system | Electricity | 98 | Expired |
| US4747124A | PBX telephone call control system | Electricity | 98 | Expired |
| US5355406A | Integrated application controlled call processing and messaging system | Electricity | 72 | Expired |
| US5517556A | Call processing system with facsimile processing | Electricity | 63 | Expired |
| US6097791A | Voice-messaging system with non-user outcalling and auto-provisioning capabilities | Electricity | 63 | Expired |
| US5117451A | Interface to and operation of a voice messaging system | Electricity | 36 | Expired |
| US7774962B1 | Removable and reusable tags for identifying bottles, cans, and the like | Physics | 24 | Active |
| US4792967A | PBX DID and E and M tie trunk integration adapter and method | Electricity | 23 | Expired |
| US5325422A | PBX telephone call control system | Electricity | 12 | Expired |
| US5991370A | Voice messaging system and method providing message delivery verification | Electricity | 7 | Expired |
| US6685069B2 | Shoulder protection device for use when carrying a ladder | Emerging Cross-Sectional Technologies | 5 | Expired |
| US8562495B2 | Upper body exercise apparatus for stationary bike | Human Necessities | 2 | Active |
| US10533793B2 | Systems and methods for multi-stage refrigeration | Mechanical Engineering; Lighting; Heating | 2 | Active |
| US10465983B2 | Systems and methods for multi-stage refrigeration | Mechanical Engineering; Lighting; Heating | 2 | Active |
| USD789465S1 | Stationary bicycle attachment | General | 2 | Active |
| USD789464S1 | Enhancement unit for upper body conditioning for a stationary bicycle | General | 2 | Active |
| US10514201B2 | Systems and methods for multi-stage refrigeration | Mechanical Engineering; Lighting; Heating | 1 | Active |
| US10514202B2 | Systems and methods for multi-stage refrigeration | Mechanical Engineering; Lighting; Heating | 1 | Active |
| US11561027B2 | Systems and methods for implementing ejector refrigeration cycles with cascaded evaporation stages | Mechanical Engineering; Lighting; Heating | 1 | Active |
| US12078394B2 | Systems and methods for regenerative ejector-based cooling cycles | Mechanical Engineering; Lighting; Heating | 0 | Active |
| US12221360B2 | Low energy ejector desalination system | Emerging Cross-Sectional Technologies | 0 | Active |
| US11725858B1 | Systems and methods for regenerative ejector-based cooling cycles | Mechanical Engineering; Lighting; Heating | 0 | Active |
| US11821668B2 | Systems and methods for implementing ejector refrigeration cycles with cascaded evaporation stages | Mechanical Engineering; Lighting; Heating | 0 | Active |
Source: USPTO / EPO open patent data. Inventor disambiguation is heuristic; counts are objective bibliographic measures.