Matrix printer with piezoelectrically driven printing needles

• US 4,193,703 A
• Filed: 01/11/1978
• Issued: 03/18/1980
• Est. Priority Date: 03/12/1977
• Status: Expired due to Term

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Sakmann, Walter
• Primary Examiner(s): Sewell, Paul T.
• Application Number:
  US05/868,561
• Time in Patent Office: 797 Days
• Field of Search: 400/124, 101/93.05, 310/328
• US Class Current: 400/124.16
• CPC Class Codes: B41J 2/26 Connection of print wire and actuator
• CPC Class Codes: B41J 2/295 using piezoelectric elements
• CPC Class Codes: H02N 2/043 Mechanical transmission means, e.g. for stroke amplification

Abstract

A matrix printer with piezoelectrically driven printing needles is described in which an electrically controlled piezocrystal arrangement transfers upon its expansion, its change of length to a buckling spring. Coupled to the buckling compression column spring is a printing needle which, upon the deflection of the buckling spring, is driven in the printing direction.

Claims

1. In a matrix printer having piezoelectrically driven printing elements, the improvements comprising:

a buckling compression column spring;

at least one piezoelectric crystal arrangement provided with electrical contacts for electrical control of the expansion of said crystal arrangement;

means for coupling the expansion of said crystal arrangement to said spring along the line of the axis of said spring to create a buckling thereof; and

a movable printing element supported adjacent to the central portion of said spring to be deflected therewith when said spring buckles;

said buckling spring being arranged between two piezoelectric crystal arrangements acting at opposite ends thereof.

2. Apparatus as described in claim 1, further including:

compression means for preloading said piezoelectric crystal arrangements in compression.