Inventor

BUTTERWORTH DONALD J

US9 patents

⚠️ This page may combine multiple inventors who share the name “BUTTERWORTH DONALD J”. Patents are grouped by organization below to help distinguish them — per-person disambiguation is on the roadmap.

GRAVER CO

4 patents

US4880513ANov 14, 1989

Method and apparatus for generating acid and base regenerants and the use thereof to regenerate ion-exchange resins

GRAVER CO57 citations95

US5250159AOct 5, 1993

Bipolar membrane stack and method for producing acid and monovalent base from impure salt

GRAVER CO24 citations91

US4707257ANov 17, 1987

Air/water distributor underdrain

GRAVER CO44 citations91

US5207879AMay 4, 1993

Bipolar membrane stack and method for production of low chloride sodium hydroxide

GRAVER CO8 citations72

ECODYNE CORP

3 patents

US4174282ANov 13, 1979

Liquid treatment apparatus

ECODYNE CORP12 citations72

US4210537AJul 1, 1980

Liquid treatment apparatus

ECODYNE CORP14 citations70

US4269707AMay 26, 1981

Apparatus and method

ECODYNE CORP16 citations66

BELL OF PENNSYLVANIA

2 patents

US4858075AAug 15, 1989

RF shielded and electrically insulated circuit board structure and method of making same

BELL OF PENNSYLVANIA28 citations90

US4777644AOct 11, 1988

Method and apparatus for testing telephone coin relays

BELL OF PENNSYLVANIA3 citations59