Browse Prior Art Database

TORSION SPRING COUNTERBALANCE MECHANISM

IP.com Disclosure Number: IPCOM000023568D
Original Publication Date: 1978-Feb-28
Included in the Prior Art Database: 2004-Mar-31
Document File: 2 page(s) / 279K

Publishing Venue

Xerox Disclosure Journal

Abstract

A mechanism for counterbalancing a pivoting copier platen having a non-linear torque deflection curve at its hinge varying with its lifting angle by means of a linear-rate torsion spring. Hinge shaft 2, positioned between shaft supports 3, 13 and attached to platen cover 1, rotates as platen cover 1 is lifted through its rotational angle. Hinge gear 4, positioned on and fixed to hinge shaft 2 and inter-meshed with cain gear 5, rotates in unison with hinge shaft 2 thereby rotating cam gear 5 in an opposite direction. Cam shaft 6, driven by cam gear 5 and supported by bearing block 7, rotates cam 8 in unison with cam gear 5. Tang 9 is an integral extension of the free end of torsion spring 10. It is in contact with cam 8 and is repositioned by the rotation of cam 8. The opposite (fixed) end of spring 10 is secured to shaft 2

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 90% of the total text.

Page 1 of 2

XEROX DISCLOSURE JOURNAL

TORSION SPRING COUNTERBALANCE
MECHAN I SM
Eugene Ritter

Proposed Classification
U.S. Cl. 355/8
mt. Cl. G03g 15/28

A mechanism for counterbalancing a pivoting copier platen
having a non-linear torque deflection curve at its hinge
varying with its lifting angle by means of a linear-rate
torsion spring. Hinge shaft 2, positioned between shaft
supports 3, 13 and attached to platen cover 1, rotates as
platen cover 1 is lifted through its rotational angle. Hinge
gear 4, positioned on and fixed to hinge shaft 2 and inter-
meshed with cain gear 5, rotates in unison with hinge shaft 2
thereby rotating cam gear 5 in an opposite direction. Cam
shaft 6, driven by cam gear 5 and supported by bearing block 7,
rotates cam 8 in unison with cam gear 5. Tang 9 is an integral
extension of the free end of torsion spring 10. It is in
contact with cam 8 and is repositioned by the rotation of cam
8. The opposite (fixed) end of spring 10 is secured to shaft 2

/

8

Volume 3 Number 1 January/February 1978 71

5

7

/3

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

Page 2 of 2

TORSION SPRING COUNTERBALANCE MECHANISM (Cont'd) X

and rotated thereby. As the platen cover 1 is lifted, tang 9
is repositioned by cam 8 to vary the spring force of spring 10
acting on shaft 2, by varying its compression, to match the
load of the platen cover as it is lifted through its
rotational angle. Different load profiles may be accommodated
by changing the geometrical shape of cam 8 and/or by changing
t...