The present invention relates to power staple guns, and relates more particularly to such a power staple gun which has pairs of staple grooves for loading staples of different lengths, and marks for indexing the loading of staples of different lengths.
Various power staple guns are well known, and intensively used for driving staples into workpieces. FIG. 1 shows a power staple gun according to the prior art, which comprises a gun body 16 having a staple nozzle 15 at one end, a coupling frame 17 at an opposite end, a magazine 10 connected between the staple nozzle 15 and the coupling frame 17 and defining two parallel staple grooves 14 for loading staples 12, and a follower member 11 for pushing staples 12 toward the nail nozzle 15. The magazine 10 further has a rectangular staple loading port 13 at one side for loading staples 12 in the staple grooves 14. When the follower member 11 is pulled backwards toward the coupling frame 17, staples 12 can then be inserted through the staple loading port 13 into the staple grooves 14. When staples 12 are loaded, the follower member 11 is released from hand to move the staples 12 forwards. If long staples are used, they can be loaded in the magazine 10 from the top side. This structure of power staple gun is still not satisfactory in function. One drawback of this structure of power staple gun is its limited application. Because the power staple gun has only one pair of staple grooves, only limited sizes of staples can be used. Another drawback of this structure power staple gun is that there is no indexing means to show staples of different specifications. When staples of different sizes are alternatively used, wrong staples may be loaded and driven into workpieces. Furthermore, when buying staples, the user shall have to check if the staples fit the power staple gun.