| 摘要 |
A safety closure for containers is particularly intended to prevent young children unscrewing caps from bottles containing medicine or poison. The closure has a screw cap which screws on the container and a safety cap which surmounts the screw cap and rotation of which in a normal position does not apply significant torque to the screw cap. Springs located and acting between the caps to provide an axial thrust bias the caps apart to the normal position determined by limiting stops. The safety cap is axially pushed down against the springs to a position where rotational coupling means on the caps can be engaged and the screw cap rotated by rotation of the safety cap. The springs are in the form of arms or tongues fixed at one end to one of the caps or to a ring interposed between the caps. The spring arms bear on one or more cap surfaces to develop the required axial thrust. As the safety cap is axially pushed down each spring arm slides on the cooperating cap surface. The latter is made concave and preferably has a curvature which increases in the direction in which the spring arm slides as the screw cap is pushed down. This feature provides an increased axial thrust in a short axial displacement. |
