FASTENER-DRIVING TOOL WITH ACTUATING STRUCTURE BIASED BY DUAL BIASING MEANS

摘要

In a fastener-driving tool comprising a housing structure defining an axis and a nosepiece extending from the housing structure, a primary actuating structure is movable between a tool-disabling position And a tool-enabling position, and a secondary actuating structure is coactive with the primary actuating structure for moving the primary actuating structure to the tool-enabling position when the secondary actuating structure is pressed firmly against a workpiece. The primary actuating structure is biased to the tooldisabling position by a primary spring or springs. The secondary actuating structure is biased away from the primary actuating structure by secondary springs. When the secondary actuating structure is pressed firmly against a workpiece, the primary spring or springs exhibit a biasing force less than the biasing force exhibited by the secondary springs. The secondary actuating structure may be also biased away from the housing structure by a tertiary spring.