Browse Prior Art Database

Dual Pitch Machine

IP.com Disclosure Number: IPCOM000095233D
Original Publication Date: 1965-Oct-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 52K

Publishing Venue

IBM

Related People

Young, RJ: AUTHOR [+2]

Abstract

Multiple pitch escapement for typewriters is obtained by use of plural racks 10 and 11 of different pitch and selectively operable pawls 12 and 13. The latter are mounted on typehead carrier 14 which is normally driven to the left by an escapement drive spring not shown. Control bail 15 functions upon print and word space operations to move the operative pawl 12 or 13 away from its rack 10 or 11 for a predetermined period of time. This permits carrier 14 to move such that reinsertion of the pawl 12 or 13 into its rack 10 or 11 stops the carrier 14 in the next rack tooth. Selection of pawls 12 or 13 for operation is accomplished by control arm 16 mounted on carrier 14 which slides shift rod 17 fore and aft. Control pins 18 and 19 engage pawls 12 and 13, respectively.

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 73% of the total text.

Page 1 of 2

Dual Pitch Machine

Multiple pitch escapement for typewriters is obtained by use of plural racks 10 and 11 of different pitch and selectively operable pawls 12 and 13. The latter are mounted on typehead carrier 14 which is normally driven to the left by an escapement drive spring not shown. Control bail 15 functions upon print and word space operations to move the operative pawl 12 or 13 away from its rack 10 or 11 for a predetermined period of time. This permits carrier 14 to move such that reinsertion of the pawl 12 or 13 into its rack 10 or 11 stops the carrier 14 in the next rack tooth. Selection of pawls 12 or 13 for operation is accomplished by control arm 16 mounted on carrier 14 which slides shift rod 17 fore and aft. Control pins 18 and 19 engage pawls 12 and 13, respectively. Forward movement of rod 17 to the right forces pin 19 to pivot pawl 13 counterclockwise and permits spring 20 to pivot pawl 12 clockwise into rack 10. Movement to the rear, i.e., to the left, forces pin 18 to pivot pawl 13 counterclockwise and permits spring 21 to pivot pawl 13 clockwise into rack 11.

Backspacing is accomplished by power driven bell crank 22. This forces racks 10 and 11 a limited distance to the right carrying with them pawls 12 and 13 and carrier 14. Driving power to bell crank 22 is abruptly terminated, allowing racks 10 and 1 1 to move to the left by spring 23. Carrier 14 also has a tendency to move to the left under the influence of its escapement drive spring n...