Throwback Thursday: Crab Braille Duplicator

Our object this week is an interesting deviceintroduced by the Royal National Institutefor the Blind (RNIB) around 1968 to emboss metal stereotype plates byhand. The “Crab Braille Duplicator” was manufactured by the Coventry Gauge& Tool Company in Coventry, England. Coventry did otherbraillewriters 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 heaviercastings allowed it to emboss metal rather than paper. Each time the keyswere pressed, the carriage would advance one space to the right until itreached the end of the line. Pins on the carriage fit into holes in abacking 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, iswhat gives it the name, as they resemble the legs on a crab. The operatorwould sit with elbows held out away from their body in order to get theirfingers in position. It is hard to imagine what your arms would feel likeafter a long day of that! But it would allow a small shop toinexpensively prepare braille stereotype plates. The plates could then beused in a modified printing press to emboss braille, or even used in a rollerpress (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 atAPH.

Stan Greenwood
A humble human, who is always found working on something or drinking coffee. A perfect introvert who talks barely anything but shares a lot through his blog posts at FredForum.

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