The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 15, 1999
Filed:
Nov. 18, 1997
Makita Corporation, Anjo, JP;
Abstract
A protection arrangement for a battery charger of the type used to charge battery packs used for electromotive tools. A self-holding protector is arranged in the neighborhood of an inserting hole of the battery charger for receiving a storage battery pack 50 to be charged. This self-holding protector element includes two elements electrically connected in parallel. One of these two elements is a bimetal which opens when it heats or flows too much current. The other of the two elements is a positive characteristic thermistor (PCT) which generates heat when a current flows through it. When a battery pack being charged becomes over-charged and heats, the bimetal element of the protector opens, and charging current stops flowing. When the bimetal element opens, electric current flows through the PCT. This current causes the PCT to heat and maintain the bimetal element in its open condition. When the battery pack being charged short-circuits, and a large current flows through it, the bimetal element opens and charging current is interrupted in the same way.