Patent GB-1416303-A (GB)
Title: Liquid dispenser and apparatus for filling same
IPC: A61M5/315
Filed: 1972-11-23
Abstract: 1416303 Liquid dispensers MPL INC 23 Nov 1972 [6 Dec 1971] 54211/72 Heading A5R [Also in Division B8] Liquid dispensers: A liquid dispenser 11, Fig. 2, comprises a barrel 13 enclosing a chamber 13a and having a rear opening closed by an elastic plunger 31, a detent 17b, Fig. 5, for engaging a forwardly facing portion on the plunger 31, and a closed pre-formed slit 37a in the plunger 31, said slit 37a being engageable through the rear opening so that the slit 37a may be opened and the chamber 13a filled with a liquid L. The barrel 13 is formed of glass and has a finger grip 17 on its rear end and a forward end section 15 having a nose 15c defining a dispensing orifice 19. A seal 41 closes the forward end of the barrel 13 which is filled from a filler cylinder 71 by means of a filler member 61. The forwardly-facing portion may comprise an annular ring 33' on the plunger 31. Plunger: The elastic plunger 31 is made of rubber and has a threaded recess 35 into which the handle 51, Fig. 1, may be screwed. Annular sealing rings 33 and alternating annular grooves 34 are formed on its curved surface. The rearmost annular ring 33' and groove 34' engage the detent 17b. A forward wall 37 of the plunger 31 has a slit 37a which is compressed to a closed position when inserted into the barrel 13 to seal it. The slit 37a may extend through the wall 37 or nearly through it so as to leave a membrane that is easily punctured by a blunt instrument, and may extend fully or partially across the face of the wall 37. In the latter case, the slit (137a), Fig. 10, (not shown), has a length greater than half the outer circumference of a tubular extension 70 of the filler member 61 to allow venting of the barrel 13. Openings (37ab), Fig. 6A, (not shown) on either side of the tubular extension 70 allow venting through the plunger 31. In another embodiment, the recess (235), Fig. 11, (not shown) is tapered in the forward direction to aid in guiding and centering the extension 70. The plunger 31 may be formed in two halves which, when brought together, define a closed slit between them. In an alternative embodiment, the members 15 and 17 may be dispensed with and an annular or other detent provided on the barrel 13 to engage the plunger 31. Seal: The seal 41 is made of an elastic material and has a cruciform ridge 43 on its flat surfaces 45. It may be popped out into a chamber 16 by pressure in the chamber 13a, whereupon the liquid L bypasses the seal 41 and may be dispensed from the barrel 13. In place of the seal 41 a rupturable membrane may be used or, alternatively, the nose 15c may be capped by a needle which inhibits free liquid flow, in which case the forward end need not be sealed. Filler member: The filler member 61 comprises a body 63 having a tubular extension 70 extending from a base flange (67), Fig. 3, (not shown) secured to the body 63. Spaced ribs (69), formed on the extension 70, provide vent spaces therebetween and also act as a stop to engage the wall 37 when the tube 70 is inserted through the plunger 31 and into the barrel 13. Contact between the forward face 65a of the filler member 61 and the rear face 31r of the plunger 31 is thereby avoided to allow the barrel 13 to be vented and so that the plunger 31 is not inadvertently pushed into the barrel 13. A bore 63b of the member 63 has a taper 63a for receiving a complementary connector 79 of the filler cylinder 71. Filler cylinder: The chamber 13a is filled, via the filler member 61 from the filler cylinder 71 by moving a plunger 77 forward in a barrel 73 to expel the liquid L through a connector 79 which is complementary to the bore 63a and inserted therein while the filler member 61 is inserted into a downwardly pointing barrel 13. When the chamber 13a is sufficiently full, the plunger 31 is pushed into the barrel 13 by means of the filler member 61 so that the sealing ring 33' is disengaged from the detent 17b and pushed into the barrel 13. The filler member 61 is then disengaged and the handle 51 screwed into the plunger, whereupon the dispenser is ready for use. The handle 51 has a shoulder 54 to prevent the threaded section 53 from being screwed too far into the plunger 31 and entering the slit 37a.