Abstract: A barrel unit of a pneumatic nail driving device includes a base plate with a pair of hooking lugs. An elongated cover plate is superimposed on and is pivoted to a rear portion of the base plate, and has a pair of pivot ears, a pair of abutment tabs projecting sidewise respectively from the pivot ears, and a pair of shoulder disposed behind the hooking lugs of the base plate. An operating lever has a pair of pivot ears mounted pivotally on the pivot ears of the cover plate in such a manner that the pivot ears of the operating lever slidably and respectively contact the abutment tabs, and a U-shaped clasper pivotally connected to the operating lever. After disposing the clasper around the hooking lugs, rearward pivotal action of the operating lever results in engagement between the clasper and the hooking lugs and subsequently causes tight engagement between the pivot ears of the operating lever and the abutment tabs, and tight engagement between the shoulders and the hooking lugs.

Abstract: A nail cartridge for a pneumatic nail driving device includes a housing that defines therein a nail groove, a plate receiving space over the nail groove, a sliding passage disposed sidewisely and offset from the nail groove, and a gap between the plate receiving space and the nail groove. The nail cartridge further includes a nail pushing plate disposed movably in a longitudinal direction in the plate receiving space and extending into the nail groove, and an urging member for urging the nail pushing plate in a manner that the nail pushing plate is moved in a transverse direction relative to the longitudinal direction into the gap so as to clear the nail groove without requiring detachment of the nail pushing plate from the housing.