Hi-Tek Dovetail Series
Contents
Overview
Dovetail Series was Hi-Tek Corporation’s modular redesign of their switch grid system. The revised design allows the switches to be manufactured separately and interlocked during keyboard assembly, thus retaining the advantage of a single-body grid assembly—the lack of requirement for a metal mounting plate—while removing the major disadvantage of needing to set up custom mould arrangement for every keyboard. The central keyboard area was still provided as a single moulding for simplicity, covering the number row down to space bar. Top and side function keys could be added in blocks of 1×4 and 4×1 switches, while 11, 12, 14, 16 and 18 key grids could be used for both integrated and separate numeric keypads. Additional keys surrounding the alphanumeric area could be added using single-key switches of various widths, separated as required by spacers. All these parts fit together using dovetail joints, hence the name of the series.
Patents were filed in 1983 (European patent 0094839) and 1984 (US patent 4564732) for this system. Prior to this, RAFI filed a dovetail switch patent, German patent 2516527 in 1975, but the complete switches are not shown.
Specifications
The following specifications are listed in the document linked below:
Full travel | 0.140±0.020″ |
---|---|
Pretravel | 0.075±0.020″ |
Operating force | 2.0±0.5 oz, momentary switches |
3.0±0.5 oz, space bar and alternate action switches | |
Contact material | Western Electric Alloy #1 |
Lifetime | 20 million cycles, momentary |
5 million cycles, alternate action | |
Contact resistance | 25 mΩ typical and 1 Ω maximum when new |
10 Ω maximum at end of life | |
Contact bounce | 0.250 ms typical and 2 ms maximum when new |
5 ms maximum at end of life | |
DC rating | 10 mA at 5 V DC, resistive load |
Parts
The following parts are listed in the document linked below (with descriptions verbatim). Wider single-key switches are not covered.
Part no. | Description |
---|---|
200453 | 47 Key Dovetail Array |
200464 | 18 Key Dovetail Keypad |
200454 | 16 Key Dovetail Keypad |
200440 | 14 Key DovetaiI Keypad |
200441 | 12 Key DovetaiI Keypad |
200457 | 11 Key DovetaiI Keypad |
200455 | 1x4 Dovetail Array |
200442 | 4x1 Dovetail Array |
200456 | 1x1 Left Hand Single Keyswitch |
200459 | 1x1 Right Hand Single Keyswitch |
200460 | 1x1 Left Hand Alternate Action Single Keyswitch |
200461 | 1x1 Right Hand Alternate Action Single Keyswitch |
100426 | 3/16″ Spacer |
107267 | ¼″ Spacer |
100427 | ⅜″ Spacer |
100428 | 9/16″ Spacer |
106243 | ¾″ Spacer |
Documents
- Dovetail Series Arrays and Keypads (possibly March 1985), supplied by former employee Susan Kennedy and digitised by Benjamin Rockwell
See also
- Hi-Tek Dovetail Series on the Deskthority wiki