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US 7,067,934 B2Granted
Starter with overheat protection device
AssigneeDenso Corporation
InventorsShigefumi Kitagawa, Tomohiro Ohmura, Hideo Tanaka
Life of this patent
Estimating the term…
Abstract
A starter capable of reliably and safely cutting off or breaking a motor circuit when the motor circuit is subjected to an excessively large thermal load is disclosed. The motor circuit includes an intermediate member made of metal and electrically connected between a motor lead wire and a positive-side brush lead wire. The intermediate member has a fuse function that undergoes melting to cutoff the motor circuit when a thermal load excessively larger than that in normal use occurs in the motor circuit.
Claims21
A starter comprising:
- an electric motor producing a rotational force when supplied with a start-up current, the electric motor having a frame and a grommet mounted on the frame;
- a motor circuit for the passage therethrough of the start-up current from a battery to the electric motor;
- and
- an electromagnetic switch disposed in the motor circuit for selectively allowing and blocking flow of the start-up current through the motor circuit,
- wherein said motor circuit comprises:
- a motor lead wire passing through the grommet and having a first end portion disposed outside the frame and connected with the electromagnetic switch and a second end portion disposed inside the frame;
- a motor internal circuit disposed internally of the electric motor and forming a current flow path through which the start-up current supplied via the motor lead wire flows;
- and
- an intermediate member made of metal and electrically connected either between the motor lead wire and the motor internal circuit or to an intermediate portion of the motor internal circuit, the intermediate member having a fuse function that undergoes melting to thereby break the motor circuit when the motor circuit is subjected to a thermal load excessively larger than that in normal use.
6 more elements
A starter comprising:
- an electric motor including a field system, an armature, a commutator disposed on the armature, and brushes disposed on the commutator, the motor generating a rotational force via the armature when a start-up current is supplied from a battery to the armature;
- an electromagnetic switch having a battery terminal connected to the battery and a motor terminal connected to the motor, the electromagnetic switch being operable to electrically connect and disconnect the battery terminal and the motor terminal;
- a current flow path formed inside the starter for the passage therethrough of the start-up current;
- and
- plural circuit parts electrically connected together to form the current flow path,
- wherein a selected one of the plural circuit parts has a conduction cut-off function that undergoes melting to cutoff the current flow path when the current flow path is subjected to a thermal load excessively larger than that in normal use, the selected circuit part being reduced in cross-sectional area over a length larger than one-half of the entire length of the selected circuit part so as to perform the conduction cut-off function.
3 more elements
Dependencies are inferred from the claim text.