| Number | Name | Date | Kind |
|---|---|---|---|
| 2622160 | Werner | Dec 1952 | |
| 3392592 | Waldorf et al. | Jul 1968 | |
| 3626120 | Wright | Dec 1971 | |
| 3711685 | Castle | Jan 1973 | |
| 3863748 | Trezise | Feb 1975 | |
| 3882295 | Madland | May 1975 | |
| 4010838 | Sims, Jr. | Mar 1977 | |
| 4071719 | Madland | Jan 1978 |
| Number | Date | Country |
|---|---|---|
| 304088 | Feb 1918 | DE2 |
| Entry |
|---|
| Harris, Electronic Keyboard Shiftlock Mechanism, IBM Technical Disclosure Bulletin, vol. 20, No. 10, p. 4037, 3/78. |
| Crome, Electronic Keyboard Shiftlock Mechanism, IBM Technical Disclosure Bulletin, vol. 20, No. 1, p. 258, 6/77. |