GB1114729A - Syringe - Google Patents

Abstract

1,114,729. Syringes. H. STRUERS CHEMISKE LABORATORIUM. March 29, 1967 [March 30, 1966], No.14273/67. Heading F1R. A syringe for dispensing measured quantities of chemicals comprises a glass plunger 3 biased outwardly by a spring 13 and movable inwardly by finger pressure on head 4, inward movement of the plunger being limited by its engagement with the bottom of the glass barrel 1 and outward movement being adjustably limited by a non- circular disc 11 clamped between nuts 8 and 9 on a threaded column 7 mounted on a plate 5 clamped on to a roller 2 on the barrel 1 by a plate 6, e.g. by screws, disc 11 being angularly adjustable out of the path of plunger 3 to permit removal of the plunger from the barrel. Disc 11 may be of soft synthetic resin, e.g. polytetrafluorethylene. A lock nut 10 may be provided. The rear faces of roller 2 and head 4 are plane ground. In the embodiment of Fig.6, for diluting a chemical, a further, readily rotatable disc 15 is mounted on a sleeve or reduced portion of nut 9 beneath disc 11, a diluting liquid being drawn into the syringe until the plunger engages the lower disc 15, which is then rotated clear of the plunger for the chemical to be diluted to be drawn into the syringe until the plunger engages the upper disc 11.