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:
Mar. 01, 1988
Filed:
Apr. 06, 1987
Hitoshi Hasumi, Saitama, JP;
Hirofumi Hirano, Saitama, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An impact type dot head for forming a character, symbol or the like by a dot matrix comprises: four printing wires arranged in a line in a wire holder; a guide member to guide the wires in parallel; four drive units each for pushing the rear edge of the wire in its axial direction and allowing the front edge of this wire to be projected to the printing position; and a foredamper consisting of a silicone rubber serving as a vibration damping material attached to the holder along its side surface. The drive unit includes an armature to clap the rear edge of the wire and an electromagnetic member to attract the armature. Each printing wire comprises a long thin-diameter portion on the front edge side, a short thick-diameter portion near the rear edge side and an intermediate taper portion connecting them. A coil spring having a diameter which is larger than the diameter of the front edge of the wire and is smaller than the thick portion is elastically attached to the wire, thereby allowing the wire to be pushed and returned from the printing position to the original portion. The printing wires therefore can be accurately guided with a simple and inexpensive structure and printing noise can be reduced.