A stapler includes a casing having a grasp hole defined therethrough and a staple receiving frame is received in the casing. A staple pushing device is engaged with the frame and a groove is defined in a periphery of the grasp hole so that a pressing rod is movably engaged with the groove. Two resilient plates each have an end fixedly connected to the casing and the pressing rod presses on the resilient plates. A staple ejection device is connected to the casing and is connected to the resilient plates. A handle is pivotally connected to the casing and disengagably connected to the staple ejection device. An outer cover is mounted to the casing and a front cover is removably connected to the casing.

A cassette for stapler capable of storing staples with different lengths of needle legs and capable of being manufactured at a low cost, comprising a cassette body formed slender with a channel shaped cross section and having a staple extrusion groove provided at the tip thereof, a staple holder longitudinally fitted to the cassette body to hold the large number of staples, a feeder for moving the staples pressingly toward the tip thereof, a spring for energizing the feeder, and a guide rod for guiding the movement of the feeder, wherein a guide wall capable of storing the staples with different lengths of needles is provided in the staple holder.

A desktop stapler uses a spring to store energy to install staples by impact blow. The force required to fasten papers together is reduced. A very compact mechanism is used, including a dual coil power spring with a nested lever. A multi function base provides a sloped front all the way to down to a desk top surface to guide paper sheets atop the base, easy access for lifting the stapler off a desk, horizontal or vertical resting positions, and integrated soft grip under-surface. The base surrounds the rear of the stapler body to provide a smooth exterior so that the device is natural to use both horizontally and vertically. A simple re-set spring provides a smooth re-set action as the handle is raised. A staple track includes enlargement features to fit a larger staple pusher spring.

A forward acting stapler includes a unique linkage for driving a firing lever. The linkage includes two links which are each connected to the trigger lever by a roller. The roller is movable within a spot in the trigger lever. As the handle is driven, the two links cause the triggering level to pivot. As the trigger lever pivots it lifts a plunger against a spring force. At some point, the trigger portion releases the plunger allowing the plunger to be returned by the spring force by a staple.

A spring energized stapler includes a "high start" design wherein a striker has a rest position above the staple track. A handle is pressed to energize a power spring while the striker remains stationary. At a predetermined position of the handle, the striker is released to eject a staple. A subassembly of a cage and the power spring provides a preload to the power spring in the rest position. The subassembly is separately movable from the handle to allow a handle pressing end to move farther than the striker's distance of travel. The handle includes a movable pivot location to enable enhanced motion of the handle pressing end. Alternatively, an optional lever links the striker to the power spring to provide leverage upon the power spring. A release latch may be mounted in front of the striker to be engaged by the lever or the handle.