Average Co-Inventor Count = 1.43
ph-index = 7
The patent ph-index is calculated by counting the number of publications for which an author has been cited by other authors at least that same number of times.
Company Filing History:
1. Koh-i-noor Rapidograph, Inc. (17 from 52 patents)
2. Rotring-werke Riepe Kg (2 from 8 patents)
3. Mesne Koh-i-noor Rapidograph, Inc. (2 from 3 patents)
4. Rotring International Gmbh & Co. Kg (1 from 8 patents)
22 patents:
1. 5392520 - Vector brush
2. 4930921 - Tubular writting pen with superposed pressure equalization chambers
3. 4854205 - Sign cutting device
4. 4552483 - Device for covering an oblong opening in a housing
5. 4549828 - Writing instrument with separable compensating means
6. 4496958 - Drawing pen exchanger for computer controlled drawing machines
7. 4489333 - Device for exchanging objects in particular writing instruments
8. 4459602 - Automatic drafting apparatus
9. 4382707 - Felt tip writing pen
10. 4356632 - Writing apparatus
11. 4221496 - Writing fluid cartridge
12. D254316 - Ink cartridge with rupturable sealing element
13. 4188634 - Method for regulating ink flow in drafting pens
14. D253180 - Combined drafting pen holder and container
15. 4130444 - Device for cleaning ink pen points