GB700808A - Piston syringe for medical use - Google Patents

Abstract

700,808. Syringes. HUSLER, S. HERTIG-, and HERTIG, W. Sept. 5, 1950 [July 20, 1950], No. 21869/50. Class 81(2) To enable piston syringes to be sterilized without removing the piston and in order to prevent the piston adhering to the cylinder wall the cylinder is provided with an enlargement at the piston receiving end in which the piston is a loose fit. As shown applied to a hypodermic, Fig. 1, the glass cylinder 1 is formed with an enlargement into which the piston 5 may be completely withdrawn. The cylinder, which is bevelled at either end, is enclosed by a case comprising an upper portion 7, webs 8 and a lower portion 9 the latter holding the connecting piece 1D of the needle. A cap 11, with bevelled surface 12 corresponding to the cylinder bevelled surface 13, completes the assembly being screwed on to the upper portion 7. By providing the needle connector 10 with bevelled surface 15 corresponding to the bevelled surface 14 of the cylinder tightening of the cap 11 will ensure a rigid syringe construction. The piston rod 17 is provided with grooves 17a, 17b, the former being engaged by a spring 19, provided in the cap 11 to surround the rod opening 16, when the piston is in its operative position, and the latter being engaged by the spring when the piston is in its completely withdrawn position. The nut 11 is formed with grips 23 and holes 22 are provided to assist sterilization. In a modification, Fig. 2, the cap 11 is provided with a dome portion. The grooves 17a, 17b, are dispensed with an enlarged portion 21 of the piston rod effecting a similar purpose. A further modification differs from Fig. 1 in that the cap 11 is provided with an external thread for engaging an internal thread of the portion 7, the head part of the cap and not the lower edge being formed with grips 23.