GB722899A - Improvements in or relating to fountain pens - Google Patents

Abstract

722,899. Reservoir pens. KOVACS, T. Aug. 23, 1951 [Sept. 4, 1950; Sept. 8, 1950], No. 19880/51. Class 146 (3). A reservoir pen has a cap 8, preferably of metal, screwed on the nib end 5 of the barrel by a thread 6 of coarse pitch co-operating with an internal thread 15 formed in a part 3 attached to the cap.. The threads may be multistart threads, for example,ten-start threads. A fixed or rotatable ring 9, which prevents unintentional unscrewing of the cap 8, is disposed around the barrel for frictional engagement with.the interior of the cap ; the ring 9 may be split, in which case it has a larger outer diameter than the internal diameter of the cap. When the cap is fully screwed on, the open end of the cap engages an abutment on the pen barrel formed by a reduced neck 7. The distance a, between the leading edges of the thread 6 and ring 9, is equal to or greater than the distance b between the rear edge of the thread 15 and the open end of the cap 8, such that the co-operating threads 6 and 15 engage before .the ring 9 contacts the cap 8. A ring, not shown, similar to the ring 9 may be provided to retain the cap on the rear end of the pen, short guide surfaces being provided in this case to engage the threads 15.