Electricity: electrothermally or thermally actuated switches – Electrothermally actuated switches – With bimetallic elements
Patent
1985-11-04
1986-12-30
Broome, Harold
Electricity: electrothermally or thermally actuated switches
Electrothermally actuated switches
With bimetallic elements
337 99, H01H 6100, H01H 7122
Patent
active
046332103
ABSTRACT:
Improved response in an ambient temperature compensated thermal overload relay is obtained by providing a bimetal element (2) wherein the main bimetal section (4) is coupled through a reversed compensating bimetal section (6) to a heat sink mounting base (8) either directly or through a heat transfer control member (18) and placing the heater (10) that is energized by the overload current only adjacent the main bimetal section (4). With this arrangement, the main bimetal section (4) bends in the switch tripping direction and the compensating bimetal section (6) bends in the subtractive direction in response to temperature change therein to reduce the net deflection for ambient temperature compensation under normal operating conditions and gradual small overload conditions. The heater (10) provides a temperature differential between the main (4) and reverse (6) bimetal sections although the reverse bimetal section (6) is subject to some conduction temperature rise above ambient temperature due to controlled thermal conduction from the main bimetal section (4) thereto and therethrough to the heat sink (8). But under fast high overload conditions, the reverse bimetal section (6) has insufficient time to incur a substantial amount of the conduction temperature rise to afford quicker tripping of the switch (16) for improved response. The ratio of the lengths of the main and reverse bimetal sections (4,6) is set or selected for the desired compensation.
REFERENCES:
patent: 2109169 (1938-02-01), Field
patent: 2338474 (1944-01-01), Wilson
patent: 3078661 (1963-02-01), Mason et al.
patent: 3124957 (1964-03-01), Bungo
patent: 3243553 (1966-03-01), Doyle
patent: 3611236 (1971-10-01), Randolph
patent: 3718162 (1973-02-01), Dafler
Autio William A.
Mallonen Edward A.
Autio W. A.
Broome Harold
Eaton Corporation
Grace C. H.
LandOfFree
Thermal overload relay with improved response does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Thermal overload relay with improved response, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Thermal overload relay with improved response will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1550279