Reverse tab control system for typewriters
US4408915A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 17, 1981 |
| Grant date | Oct 11, 1983 |
| Priority date | — |
| Expiry date | Aug 17, 2001 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41J21/08
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A typewriter has a Keyboard (12), including a Tab Set Key (22), a Tab Clear Key (24), and a Tab Actuating Key (26). Operation of the tab set key stores stop positions of the Carrier (18) with respect to the typewriter's Platen (14). Shallow depression of the tab actuating key causes the carrier to move forward (right) to the next tab stop position. A first deep depression of the tab actuating key establishes a Reverse Tab Mode causing the carrier to move backward (left) to the nearest preceding tab stop position and causing the platen to rotate (index) so as to position the Printing Element (16) one line down on the paper, thereby to facilitate typing the next line of single column material without effecting a carrier return and forward movement of the carrier to the beginning of the column. Each subsequent shallow depression of the tab actuating key causes the carrier to move backward to the next preceding tab stop position without indexing, thereby to facilitate typing the next line of multiple column material without effecting a carrier return and forward movements of the carrier. The Reverse Tab Mode can be ended by activating almost any other key, whereupon subsequent shallow …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.