bobbin vs cable tray

bobbin

noun
  • A spool or cylinder around which wire is coiled. 

  • A fine cord or narrow braid. 

  • The little rounded piece of wood at the end of a latch string, which is pulled to raise the latch. 

  • In a sewing machine, the small spool that holds the lower thread. 

cable tray

noun
  • A rigid structure to support electric cables; a type of raceway, normally having the appearance of a ladder and open at the top to facilitate changes. 

How often have the words bobbin and cable tray occurred in a corpus of books? (source: Google Ngram Viewer )