Throwback Thursday: Crab Braille Duplicator

Our object this week is an interesting device introduced by the Royal National Institute for the Blind (RNIB) around 1968 to emboss metal stereotype plates by hand.  The “Crab Braille Duplicator” was manufactured by the Coventry Gauge & Tool Company in Coventry, England.  Coventry did other braillewriters and slates for RNIB as well, under the brand name Matrix.  The basic design for the “Crab” was based on the much older Stainsby-Wayne Braillewriter (introduced around 1903) and it worked in much the same way, except its heavier castings allowed it to emboss metal rather than paper.  Each time the keys were pressed, the carriage would advance one space to the right until it reached the end of the line.  Pins on the carriage fit into holes in a backing board and could be advanced down the board one line at a time, literally by the lifting the carriage and sliding it down one position.  The most distinguishing feature on the machine, its widely splayed six keys, is what gives it the name, as they resemble the legs on a crab.  The operator would sit with elbows held out away from their body in order to get their fingers in position.  It is hard to imagine what your arms would feel like after a long day of that!  But it would allow a small shop to inexpensively prepare braille stereotype plates.  The plates could then be used in a modified printing press to emboss braille, or even used in a roller press (it looked and acted like an old fashioned wringer on a washing machine) also available from RNIB.  This example was found in our model shop at APH.


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