Counting cap for medicine bottles

Claim 1

A container for medicinal tablets, the cap of which contains a window through which a serial indicator is visible, the serial indicator advancing each time the container is opened and closed, the open end of the container and the cap being generally cylindrical and being attached to each other by multiple-start threads on the container which are engaged by lugs on the cap, and having a disc-spring member inside the cap, held down by the cap and sealing to the rim of the container opening, wherein the improvement comprises: first and second abutment surfaces on the threads, said first abutment surfaces limiting rotation of the cap in the engaging direction by abutting the lugs on the cap, and said second abutment surfaces similarly limiting rotation of the cap in the disengaging direction, the rotation motion allowed to the cap being greater than the spacing between thread starts, and an indicator element on which a number of serial indications are marked, the number being the number of thread starts, said indicator element being located within the cap, extending under the window and having a skirt which passes outside the disc-spring member and inside the cap, and a number of finger-springs fixed to the skirt of said indicator element, said finger springs extending from the skirt both toward the container and circumferentially in the direction of disengagement, having on the end a shape which will engage said second abutment means, and being of a circumferential length, angle of placement, and flexibility that said finger-springs may be carried by friction between the cap and said indicator element along with the cap when the cap is rotated in an engaging direction, whereby the cap and indicator element will move together when the cap is rotated to engage the container, and said finger-springs will abut said second abutment surface overcoming friction and causing rotation between the cap and indicator element when the cap is rotated in the disengaging direction, this rotation indexing said indicator element and advancing the serial indication each time the container is opened.