"small bell so hung as to ring notice of the opening of a shop door," 1853, from shop (n.) + bell (n.).
Entries linking to shop-bell
shop n.
c. 1300, "booth or shed for trade or work," perhaps from Old English scoppa, a rare word of uncertain meaning, apparently related to scypen "cowshed," from Proto-Germanic *skoppan "small additional structure" (source also of Old High German scopf "building without walls, porch," German dialectal Scopf "porch, cart-shed, barn," German Schuppen "a shed"), from a root *skupp-. Or the Middle English word was acquired from Old French eschoppe "booth, stall" (Modern French échoppe), which is a Germanic loan-word from the same root.
The meaning "building or room set aside for sale of merchandise" is from mid-14c. The meaning "schoolroom equipped for teaching vocational arts" is from 1914, American English (as in shop class, attested by 1948).
The sense of "one's own business, craft, or calling" is from 1814, as in talk shop (v.), "converse in general society about matters pertaining to one's trade," which is attested by 1860. Shop-talk (n.) is by 1881.
bell n.
"hollow metallic instrument which rings when struck," Old English belle, which has cognates in Middle Dutch belle, Middle Low German belle but is not found elsewhere in Germanic (except as a borrowing); perhaps from an imitative PIE root *bhel- "to sound, roar" (compare Old English bellan "to roar," and see bellow).
As a division of daily time aboard a ship, by 1804, from its being marked by bells struck every half hour. The statistical bell curve is by 1920, said to have been coined 1870s in French. Of glasses in the shape of a bell from 1640s. Bell pepper is from 1707, also so called for its shape. Bell, book, and candle is a reference to a form of excommunication (the bells were rung out of order and all together to signify the loss of grace and order in the soul of the excommunicated).
To ring a bell "awaken a memory" (1934) is perhaps a reference to Pavlovian experiments; it also was a signal to summon a servant (1782).