Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
134 words
A diesel fuel heater in combination with, a fuel filter housing having an inlet and outlet and including a filter element secured to the filter housing, said heater comprising; a heater housing having means defining an inlet thereto, at least one positive temperature coefficient thermistor, means coupling power to the thermistor, a mounting plate for the thermistor having means defining an outlet therefrom, means retaining the thermistor to the mounting plate, and means for mounting the heater housing and mounting plate to the fuel filter housing with the heater housing overlying the mounting plate and defining therewith a fuel passage extending from the inlet of the heater housing to the outlet from the mounting plate, the circulating fuel passing via the filter housing through the fuel passage over the thermistor to the filter element.
Claim 2
Dependent Claim
134 words
A diesel fuel heater in combination with, a fuel filter housing having an inlet and outlet and including a filter element secured to the filter housing, said heater comprising; a heater housing having means defining an inlet thereto, at least one positive temperature coefficient thermistor, means coupling power to the thermistor, a mounting plate for the thermistor having means defining an outlet therefrom, means retaining the thermistor to the mounting plate, and means for mounting the heater housing and mounting plate to the fuel filter housing with the heater housing overlying the mounting plate and defining therewith a fuel passage extending from the inlet of the heater housing to the outlet from the mounting plate, the circulating fuel passing via the filter housing through the fuel passage over the thermistor to the filter element.
Claim 3
Dependent Claim
27 words
A diesel fuel heater as set forth in claim 1 wherein said heater housing has an open bottom defining with the mounting plate an annular fuel passage.
Claim 4
Dependent Claim
16 words
A diesel fuel heater as set forth in claim 2 including a plurality of PTC thermistors.
Claim 5
Dependent Claim
34 words
A diesel fuel heater as set forth in claim 3 wherein said means for retaining the thermistors includes conductive epoxy or solder respectively holding said thermistors in a planar array to the mounting plate.
Claim 6
Dependent Claim
32 words
A diesel fuel heater as set forth in claim 4 including dam means in the fuel passage for directing fuel flow in one direction toward the outlet and over all PTC thermistors.
Claim 7
Dependent Claim
36 words
A diesel fuel heater as set forth in claim 5 wherein said means for coupling power to the thermistors includes a contact spring means disposed in the fuel passage and having separate contacts for each thermistor.
Claim 8
Dependent Claim
28 words
A diesel fuel heater as set forth in claim 1 wherein the thermistor is a low temperature thermistor having a switching temperature in the range of 0°-15° C.
Claim 9
Dependent Claim
31 words
A diesel fuel heater as set forth in claim 1 including a thermostat associated with the heater housing and adapted to be in circuit with the thermistor to control heater temperature.
Claim 10
Dependent Claim
35 words
A diesel fuel heater as set forth in claim 8 wherein the thermostat has a switch "on" temperature on the order of 24° F. and a switch "off" temperature on the order of 56° F.
Claim 11
Dependent Claim
53 words
A diesel fuel heater as set forth in claim 1 wherein the inlet in the heater housing is positioned to receive fuel into the fuel passage from thereover, the outlet in the mounting plate being disposed circumferentially spaced from the inlet and positioned to permit fuel flow downwardly therefrom to the filter element.