a coin mechanism for a vending machine comprises a cylinder rotatable in a passageway within a housing to release vended product to a purchaser . operation of the mechanism requires insertion of purchase coins into coin slots accessible when the cylinder partially protrudes from the housing . the cylinder is thereafter substantially completely inserted into the housing and rotated by means of a handle located on one end thereof . upon rotation of the cylinder , the coins prevent engagement of locking pawls mounted in the housing with either of two separate mechanism - blocking shoulders located on the cylinder . the end of the cylinder opposite the handle is connected to a coupler member , which in turn is fastened to a spiral product coil , rotation of the cylinder causing rotation of the coil and the release of product therefrom . the coupler member also includes a ratchet wheel which cooperates with a pawl in the housing to prevent improper rotation of the cylinder . changes in the number and kind of coins required to operate the mechanism can be effected by adjusting the degree of cylinder travel into the housing , and by the insertion of coin - altering plugs inserted in the cylinder &# 39 ; s coin slots .