Inventor
LLEWELLYN DAVID T
US8 patents
Patents
8 patentsUS5198632AMar 30, 1993
Pressure operated switch construction and method of making the same
ROBERTSHAW CONTROLS CO7 citations72
US4993144AFeb 19, 1991
Method of making a cyclable electrical switch construction
ROBERTSHAW CONTROLS CO7 citations71
US4883983ANov 28, 1989
Switching system for plural load circuit
ROBERTSHAW CONTROLS CO7 citations71
US5310970AMay 10, 1994
Pressure operated switch construction and method of making the same
ROBERTSHAW CONTROLS CO3 citations61
US5140742AAug 25, 1992
Method of making a pressure operated switch
ROBERTSHAW CONTROLS CO5 citations61
US5136129AAug 4, 1992
Pressure operated switch construction and method of making
ROBERTSHAW CONTROLS CO4 citations61
US4696204ASep 29, 1987
Water level control device and method of making the same
ROBERTSHAW CONTROLS CO6 citations61
US4800633AJan 31, 1989
Method of making a water level control device
ROBERTSHAW CONTROLS CO1 citations51