Spring clip and driver therefor

A combination of a spring clip and a clip driver for binding materials by using the spring clip,

• said spring clip being made of a single elastic plate member and including a connection portion provided substantially at a longitudinal center of the elastic plate member and a pair of grasping portions each having one end integrally connected to the connection portion and a free end at an opposite side thereof, said free ends elastically contacting with each other and being opened against elasticity of the grasping portions when a force is applied to the free ends of the grasping portions so that the materials can be inserted between the free ends and elastically grasped therebetween when said force is removed, each of said grasping portions being defined by a front edge forming said free end, a rear edge forming a boundary between the grasping portion and the connection portion, and widthwise opposite side edges each extending between the front edge and the rear edge at widthwise opposite sides of the grasping portion, each of the grasping portion having a width wider at the front edge than at the rear edge, each of the widthwise opposite side edges extending substantially linearly, said grasping portions having end surfaces at the free ends respectively, said end surfaces being formed to have a gap therebetween at the front edges of the grasping portions, said clip driver including;
• a lower casing having at its front end a lower opening portion forming a part of an insertion inlet for said materials, said lower casing having an upper surface on which at least one said clip is mounted with said grasping portions directed toward said insertion inlet so that said clip is slidable in a longitudinal direction of said clip driver;
• an upper casing having at its front end an upper opening portion forming said insertion inlet together with said lower opening portion of said lower casing and having at its rear end a clip insertion inlet for inserting said clip and a rectangular opening at its front end side to extend in the longitudinal direction thereof;
• a knob mounted in the rectangular opening in said upper casing, said knob being slidable in said longitudinal direction and being movable up and down within a predetermined range, said knob having a knob projection portion projected upward from said opening, a push-out portion formed on a front end of said knob projection portion so that said push-out portion comes to abut on said connection portion of said clip when said knob is lowered, and a projection portion rearward extending from a rear end of said knob projection portion;
• a pair of clip opening spring members provided in said insertion inlet formed by said lower and upper casings for opening said grasping portions of said clip in opposite directions to each other, each of said clip opening spring members having a base portion having a thickness less than a distance of said gap of said clip, and a pair of spring leg portions extending from a front end of said base portion and elastically biased in the direction so as to separate from each other, said clip opening spring members being disposed in said casing so that the distance between opposite inner side edges of said two base portions is made longer than the width of said grasping portions at said rear edge of said clip while shorter than the width of said grasping portions at said front edge thereof, said pair of spring leg portions being tapered at front end side edges opposite to each other so that an interval between said front end opposite sides edges of said spring leg portions becomes wider than the width of said front edges of said clip as a distance from the base portion of the spring leg portion increases.