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Hi-Tek Dovetail Series



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.


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


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


See also