초록 ▼

An electrically powered stapler is disclosed having a sliding blade for driving staples which is reciprocated by a lever and crank mechanism driven by an electric motor through a torque increasing gear train. Jamming of the stapler is prevented by mounting the lever's fulcrum on a plunger which is r

An electrically powered stapler is disclosed having a sliding blade for driving staples which is reciprocated by a lever and crank mechanism driven by an electric motor through a torque increasing gear train. Jamming of the stapler is prevented by mounting the lever's fulcrum on a plunger which is releasably retained to a fixed support by a flexible collar. The plunger has an enlarged head, and the collar has a plurality of flexible fingers which grip the plunger behind the head to retain the plunger to the collar. The plunger can be disengaged from the collar by the application of a predetermined force directed away from the plunger, such as occurs on the fulcrum during a jammed condition when the blade cannot drive a staple and is stalled. The pivot point of the lever then shifts to the blade end of the lever and the plunger is reciprocated by the lever instead of the blade, allowing the motor and other components to cycle through their full range of motion without stalling. The plunger is reengaged into the collar automatically as the plunger is reciprocated and the stapler is again ready to staple.

대표청구항 ▼

[ What is claimed is:] [1.] A stapler using wire staples for stapling sheet material, said stapler comprising:a magazine for holding the staples, said magazine having a dispensing opening to allow the staples to be stripped from said magazine one at a time;a blade slidably mounted for reciprocal mot

[ What is claimed is:] [1.] A stapler using wire staples for stapling sheet material, said stapler comprising:a magazine for holding the staples, said magazine having a dispensing opening to allow the staples to be stripped from said magazine one at a time;a blade slidably mounted for reciprocal motion with respect to said magazine, said blade reciprocating through a forward and a reverse stroke and being interengagable on the forward stroke with a staple disposed at said dispensing opening for stripping said staple from said magazine;an anvil positioned with respect to said dispensing opening to clinch a staple stripped from said magazine and forced thereagainst by said blade during the forward stroke;an elongated lever, said blade being pivotally attached to said lever at a first attachment point;a first fulcrum for said lever, said first fulcrum being pivotally attached to said lever at a second attachment point spaced from the first attachment point;an actuator for imparting rocking motion to said lever, said actuator being pivotally attached to said lever at a third attachment point displaced from the first and second attachment points;a first support for said first fulcrum, said first fulcrum translating the rocking motion of said lever to reciprocal motion of said blade when said first fulcrum is positioned on said first support, said lever being free to pivot about said first attachment point when said first fulcrum is separated from said support;a flexible retainer for maintaining said first fulcrum on said first support, said retainer being yieldable to allow separation of said first fulcrum from said first support in response to forces preventing blade movement through said forward stroke; anda second support interengagable with said blade at said first attachment point for preventing liner movement through a reverse stroke when said first fulcrum is separated from said first support, said first attachment point thereby forming a second fulcrum for said lever, said actuator pivoting said lever about said second fulcrum to again engage said first fulcrum with said first support after said first fulcrum is separated therefrom.