| 摘要 |
<p>1,011,302. Making hypodermic needles. H. DUNMIRE. Dec. 10, 1962 [Dec. 8, 1961], No. 46596/62. Heading B3A. [Also in Division A5] A sharp.pointed article, particularly a hypodermic needle, is made from a work hardenable metal blank 5, Fig. 4, by cold working the portion 42 to be sharpened so as to reduce its thickness and cause work hardening. A flat strip of metal 5, Fig. 2, preferably of nickelchrome steel, brass or plated carbon steel, is punched out to leave a tongue 42 and this is tapered at 44 in coining or swaging dies with consequent work hardening to give a sharp point. A blank 51 with parallel sides 52, 53 and including the hardened tip 57 is partially punched from the strip and displaced out of its plane, but remains connected thereto at 58; simultaneously the point is bent inwardly towards the strip, Fig. 5 (not shown). In the next step the blank 60 is folded about its axis into U-section and is then bent upwardly perpendicular to the plane of the strip. The sides 52, 53 are then closed into a tube 28, Fig. 1, and a base 26 with the needle upstanding therefrom is punched out of the strip. The finished needle thus has its point 57a, Fig. 8, formed without grinding to less thickness than the wall of the tube. The resulting discharge aperture has sharp cutting edges to assist penetration of the needle. The latter 28 is used in a disposable injection device, Fig. 1, having a body portion 20 with its flange 22 sealed to a base 35 carrying a gland 36 which is pierced by the needle during the injection. The body and flange may be of polyvinyl compounds of polyethylene with a metal insert ring 41 or may be of plastic coated metal foil. The shape of the body is stated to prevent it expanding elastically after being collapsed during an injection. Reference is also made to making surgical needles and sulines. Specifications 770,341 and 1,011,301 are referred to.</p> |
