David U. Hillstrom
61Patents
21h-index
22Co-inventors
88Inventor score
Filing activity: Feb 23, 1976 → Apr 22, 2011
Most-cited inventions
| Patent | Title | Area | Cited by | Status |
|---|---|---|---|---|
| USD392686S | Sign stand with rolling base | General | 90 | Expired |
| US6125565A | Outdoor menu display device | Emerging Cross-Sectional Technologies | 81 | Expired |
| USD351863S | Free standing sign stand | General | 67 | Expired |
| US4145828A | Poster display device | Physics | 47 | Expired |
| US4691892A | Sign and sign stand | Fixed Constructions | 42 | Expired |
| US5815971A | Poster frame with moisture seal | Human Necessities | 39 | Expired |
| US5428913A | Pole banner system | Physics | 35 | Expired |
| US4033536A | Mounting bracket coil spring | Mechanical Engineering; Lighting; Heating | 32 | Expired |
| US7584563B2 | Sign stand with rolling base | Emerging Cross-Sectional Technologies | 32 | Expired |
| US4756107A | Display retention and tensioning frame | Physics | 30 | Expired |
| US4433935A | Sign bracket | Emerging Cross-Sectional Technologies | 30 | Expired |
| US4958458A | Poster display device with longitudinal retention of frame sections by inserts | Human Necessities | 29 | Expired |
| US5829178A | Portable collapsible sign and stand | Fixed Constructions | 29 | Expired |
| USD360078S | Wall mounted sign frame | General | 28 | Expired |
| US5442871A | Poster and sign display assembly | Physics | 26 | Expired |
| US4138787A | Display holder | Physics | 25 | Expired |
| US5983543A | Outdoor menu display device | Emerging Cross-Sectional Technologies | 25 | Expired |
| US6606809B2 | Fold-up sign panel assembly | Physics | 23 | Expired |
| US5675923A | Rigid sign with protective changeable indicia member | Physics | 23 | Expired |
| US5725186A | Universal flexible sign mounting device | Fixed Constructions | 22 | Expired |
| US4937959A | Poster display device with longitudinal retention of frame sections | Physics | 21 | Expired |
| US6056250A | Sign stand for flexible traffic control signage | Fixed Constructions | 21 | Expired |
| US6560906B1 | Portable sign stand having frangible post | Emerging Cross-Sectional Technologies | 20 | Expired |
| US4730803A | Ground access elevated pole banner | Physics | 20 | Expired |
| US6755381B1 | Portable sign stand with leg release mechanism | Mechanical Engineering; Lighting; Heating | 20 | Expired |
Source: USPTO / EPO open patent data. Inventor disambiguation is heuristic; counts are objective bibliographic measures.