Browse Prior Art Database

COMBINED SWEEPING GAP AND CLOSING GAP C-YOKE SOLENOID FOR HAMMER DRIVE

IP.com Disclosure Number: IPCOM000025028D
Original Publication Date: 1983-Jun-30
Included in the Prior Art Database: 2004-Apr-04
Document File: 4 page(s) / 151K

Publishing Venue

Xerox Disclosure Journal

Abstract

A hammer driver, for an impact printer, for moving a spring mounted hammer about a pivot support against a printwheel, is described in U.S. Patent No. 4,327,639. The driving mechanism for the hammer arrangement comprises a magnetically permeable plunger cooperating with a C-yoke solenoid in a sweeping gap relationship for producing a long stroke of substantially constant force. The plunger is mounted upon a pivot frame which, in turn, is attached to a pivotable spring arm, upon which a hammer is secured. The spring mounting enables the hammer to rebound from its initial impact with the print element and the platen and to impact a second time, while the plunger is still driving in the forward direction. In the patented arrangement, the second impact necessarily will be of lower force than the first.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 58% of the total text.

Page 1 of 4

CEROX DISCLOSURE JOURNAL

COMBINED SWEEPING GAP AND

FOR HAMMER DRIVE Enrique J. Klein

Proposed CLOSING GAP C-YOKE SOLENOID Classification

U.S. C1. 101/93.34 Int. CI. B41j 1/22

Volume 8 Number 3 May/June 1983 179

[This page contains 1 picture or other non-text object]

Page 2 of 4

COMBINED SWEEPING GAP AND CLOSING GAP C-YOKE SOLENOID FOR HAMMER DRIVE (Cont'd)

0 I

-X

FIG. 4

 XEROX DISCLOSURE JOURNAL Volume 8 Number 3 May/June 1983

180

[This page contains 1 picture or other non-text object]

Page 3 of 4

COMBINED SWEEPING GAP AND CLOSING GAP C-YOKE SOLENOID FOR HAMMER DRIVE (Cont'd)

A hammer driver, for an impact printer, for moving a spring mounted hammer about a pivot support against a printwheel, is described in U.S. Patent No. 4,327,639. The driving mechanism for the hammer arrangement comprises a magnetically permeable plunger cooperating with a C-yoke solenoid in a sweeping gap relationship for producing a long stroke of substantially constant force. The plunger is mounted upon a pivot frame which, in turn, is attached to a pivotable spring arm, upon which a hammer is secured. The spring mounting enables the hammer to rebound from its initial impact with the print element and the platen and to impact a second time, while the plunger is still driving in the forward direction. In the patented arrangement, the second impact necessarily will be of lower force than the first.

In the present disclosure, there is described and illustrated a modified driving mechanism for increasing the ratio of the second hammer impact to the first. As graphically illustrated in Figure 4, a second impact boost is generated by a ''short stroke force", resulting in the desired combined force profile. This has been achieved by combining the sweeping gap C-yoke solenoid structure with the closing gap solenoid structure. Three embodiments are illustrated for achieving the combined force profile.

In each of the embodiments the driving structure comprises a magnetically permeable plunger 10 cooperable with pole pieces 12 and 14 of C-yoke solenoid 16 having a central winding 18. The plunger 10 is mounted upon a pivot frame 20 to which is secured a pivotable spring arm 22 supporting hammer 24. The plunger and...