US 4,734,559 AGranted

Remotely electronically controlled soldering instrument

OwnerWilliam S. Fortune, Wayne A. Murrayinventors

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Abstract

A hand held, electronically controlled soldering instrument in which the electronic control module is placed several feet along the power cord away from the tool utilizes the power cord leads to measure the resistance of the heater element during each inflection point of the AC input power. The resistance magnitude is used to provide a signal which is a function of the temperature of the heater element. This signal, in turn, is used to control the electric current to the heater element. This arrangement thermally isolates the heater element and the sensitive electronic control circuit and also removes the heat generating circuitry from the handle of the soldering tool. The handle is further cooled by minimizing the heat flow from the heater element to the handle and by using conductors in the power cord as heat sinks to remove heat from the base end of the heater element shaft. A skirt-collar element is placed over a major portion of the handle portion as a fastener element between the heater element shaft and the handle; and, because it is annularly spaced from the handle, it provides an especially cooled grip for the hand and fingers of the operator.

Claims11

Dependent claims

Hand held soldering instrument comprising:

a heating element assembly having a front end portion carrying a soldering tip and a rear, base end, handle engaging portion, an enlarged diameter portion on said heating element assembly being disposed forwardly contiguously to said handle engaging portion forming a forwardly exposed, first retaining shoulder;
a handle element disposed rearwardly of said heating element assembly with its forward end disposed against said handle engaging portion;
an outer skirt element disposed concentrically over the base end portion of said heating element assembly and the forward portion of said handle element and having an inner diameter larger than said handle element thereby defining an annular, insulating space therebetween, the forward end of said outer skirt element being partially closed to form a reduced diameter collar engaging said forwardly exposed first retaining shoulder of said heating element assembly and rearwardly biasing said handle engaging portion toward the forward end of said handle element;
and
axially disposed latching means carried by the rear portion of said outer skirt element and said handle element removably, axially compressively locking together said handle element and said heating element assembly.

2 more elements

Dependencies are inferred from the claim text.