GB677523A — Discharge structure for hypodermic injection device

USPTO Abstract

677,523. Hypodermic syringes. BECTON DICKINSON & CO. April 12, 1949 [April 13, 1948], No. 9932/49. Class 81 (ii). In a hypodermic device for injecting medicament without the aid of a tissue-penetrating needle the medicament is discharged at high velocity through a number of minute orifices formed in an end wall of the device. As shown, Fig. 1, the body 20 of the device is formed with a bore 21 within which a plunger 22 is projected. The end wall of the device comprises an ampoule having a body 23 sealed by a rubber stopper 24 and is attached to the body 20 by a screw-ring 26 engaging its flange 25. Minute orifices 28 are formed in the ampoule wall 27 and, as shown in Fig. 3, may be countersunk as at 29. In Fig. 4, the orifices 38 are formed in a screw-cap 37 the ampoule 31 being provided with a stopper 32 and pierceable rubber closure member 33. A cannula 34, which is mounted upon a base plate 35 bearing against a washer 36, pierces the member 33 on tightening of the cap 37. In another embodiment, Fig. 5, the orifices 44 are provided in a plate 43 having its flange clamped between and retained by the ring 39 and base mounting member 41. In one modification of the embodiment shown in Fig. 5, no cannula is used the member 33 being provided with a central perforation. In another modification the ampoule 31 is provided with a removable rubber or plastic cap covering the perforation in the member 33. Again, the lower end of the ampoule may be provided with a rubber closure member the outer face of which is provided with grooves extending longitudinally of the member and connecting with lateral extending grooves formed in its lower face. In a further modification the ampoule is closed at its lower end by a rubber member formed with a recess similar to that shown in Fig. 4. The thin wall of the member remaining is cross-slitted at 53, Fig. 12, to provide flaps 54 integral with the member. In further embodiments of the invention, with and without cannulas, the closure member 33 is provided with a head or flange which extends outwardly beyond the edge of the ampoule body 31 the orifices being formed in a plate similar to that shown in Fig. 5 and attached to the main body 20 in a similar fashion.