Browse Prior Art Database

Serial Printhead Having Linac Technology

IP.com Disclosure Number: IPCOM000034240D
Original Publication Date: 1989-Jan-01
Included in the Prior Art Database: 2005-Jan-27
Document File: 4 page(s) / 117K

Publishing Venue

IBM

Related People

Mathews, RD: AUTHOR [+2]

Abstract

The disclosed invention provides several improvements for existing serial printheads. The improvements include the combination of a low mass hammer with a damper, an efficient magnetic flow path resulting in sustained acceleration of the actuator shaft, and a simple assembly design that can be automated. (Image Omitted) As illustrated in Fig. 1, the printhead assembly comprises 9 stators 1 and 9 print wires 2. As shown in Fig. 2, each stator 1 comprises a hammer assembly 3 that oscillates up and down in response to a magnetic field formed inside the stator. For each stator in the printhead assembly, there is a stand 4 on which is mounted a leaf spring 5 which supports an arm 6 of the hammer assembly 3 and presses it against the rear cover 7 in its rest position.

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Serial Printhead Having Linac Technology

The disclosed invention provides several improvements for existing serial printheads. The improvements include the combination of a low mass hammer with a damper, an efficient magnetic flow path resulting in sustained acceleration of the actuator shaft, and a simple assembly design that can be automated.

(Image Omitted)

As illustrated in Fig. 1, the printhead assembly comprises 9 stators 1 and 9 print wires 2. As shown in Fig. 2, each stator 1 comprises a hammer assembly 3 that oscillates up and down in response to a magnetic field formed inside the stator. For each stator in the printhead assembly, there is a stand 4 on which is mounted a leaf spring 5 which supports an arm 6 of the hammer assembly 3 and presses it against the rear cover 7 in its rest position. The rear cover of the printhead assembly also forms a bearing 8 for the top portion of the actuator shaft 9 that extends through the core of the stator, and further provides a damper assembly 10 to eliminate any unwanted bounce of the hammer assembly. The actuator shaft 9 utilized in this printhead assembly in conjunction with the stator combines linac and clapper magnet technologies. As shown in Fig. 3, the actuator shaft 9 is a component of the print hammer 3. The print hammer comprises the shaft 9 with two axially-spaced magnetic iron discs 11 known as linac teeth, a larger disc 12 known as a clapper, an arm 6, and a print wire 2. As illustrated, the arm is welded to the upper portion of the shaft, and the print wire is welded to the opposite end of the arm from the shaft and in parallel relationship with the shaft. Referring again to Fig. 2, the shaft is supported by a bearing 8 formed in the rear cover, and a bearing 22 at the opposite end of the stator. The print wire 2 is straight. The shaft is inserted into a stator so that the linac teeth (discs 11) are

(Image Omitted)

aligned in the stator air gaps. As the shaft oscillates within the stator in response to magnetic fields in the stator, the print wire is accelerated and forced into contact with...