Average Co-Inventor Count = 1.50
ph-index = 3
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. Evans Products, Inc. (3 from 3 patents)
3 patents:
1. 5159139 - Drumhead with overtone suppression
2. 5107741 - Muffler for bass drums
3. 4779508 - Drumhead construction