| 摘要 |
PURPOSE:To quickly and surely open and close a shutter, by using a spring made of a metal which has at least two points of inflection, at which the metal is bent in different directions, and is bent to have an almost V-shape as a whole in a plane, as a spring to be used for opening and closing the shutter. CONSTITUTION:When a shutter 9 compresses the spring 11 for information recorder of this invention, bending forces applied to the constricted sections 11a and 11b and circular arc section 11c of the spring 11 become opposite in direction to each other between the outside and inside as shown by the arrows, since the spring 11 has points of inflections between the constricted sections 11a and 11b and circular arc section 11c, respectively. Namely, the directions of the bending forces on the outside and inside of the constricted sections 11a and 11b respectively become (e) and (f) and (g) and (h). The directions on the outside and inside of the circular arc section 11c respectively become (i) and (j) and (k) and (l). Thus the directions of the bending forces applied to each part become opposite to each other. The elastic force produced at this section, therefore, acts as if it displaces the metal wire constituting the spring 11 in directions crossing each other at right angles with the points of inflection being fulcra. Thus a strong elastic force can be obtained.
|
