The improved type positive pressure back type safety syringe, a sheath, a sealing gasket, a needle tube, a needle seat, a damping ring, a piston and a push rod and the outer cylinder; a sealing gasket in the front and the middle seat junction and the outer cylinder cone hole is formed between the gas seal; the damping ring diameter is slightly smaller than the needle diameter, but greater than the posterior segment the middle seat diameter, the needle seat bottom after damping trap installed in the front end of the outer tube, so that the formation of liquid seal between the needle seat, a damping ring, the outer cylinder; the surface of piston has an annular groove, the piston diameter is slightly larger than the outer diameter, the piston and the push rod is arranged in the outer cylinder and the inner wall of the outer cylinder in a sliding closely. After the injection, continue to squeeze the push rod, needle sharp skirt and the push rod hole at the lower end of sharp edges can be cut into the surface of the piston rod to open the window, the outer cylinder compression damping ring forward, front air cavity, release needle damping ring forward to the middle, the needle needle, needle tube into the cavity of the piston rod of compressed air, the recovery window, the needle shield is not exposed. The utility model has the advantages of simplicity, practicality, low cost, safety and reliability.
【技术实现步骤摘要】
改进型正压回缩式安全注射器(—)、
本技术涉及一种医疗器械,具体的说是用于对人体组织的穿刺过程及其在穿刺后向组织内注射给药或抽取组织标本的改进型正压回缩式安全注射器。(二 )、
技术介绍
中国专利申请号201210221311.1公布了气压式回缩自毁注射器,包括注射筒、筒状的空心注射杆、针座、密封垫、活塞和密封接头,针座的中央设置有针头,针座通过套装在其下端的密封垫安装在注射筒的前端,活塞套设在注射杆前端的外侧,密封接头设置在注射杆前端的内测,密封接头和针座上设有互相配合的连接结构,其特征在于:当所述注射杆推至所述注射筒的前端时,注射筒前端的内壁与针座前端的外壁气密封,注射杆内壁上设置有阻止密封接头和针座从注射杆下端射出的限位装置,注射杆下端设置有沟通注射杆内腔与外界的排气孔。所述的针座的下部向外凸起形成限位座,密封垫套装在限位座上并使针座外壁和注射筒内壁气密封;所述的限位装置有两个,分别设置在注射杆中部和下部,限位装置就是注射杆内壁上的三道凸筋。该技术方案虽较以往的利用机械力(弹簧力或人工拉力)使针座和针管回缩的自毁或安全注射器有较大进步,但仍然存在以下不足:①、针座前端与注射筒前端依靠斜面且是在注射杆推至注射筒前端时,利用注射杆对针座与外筒前端内壁的压力,使二者形成密封,此方法在大批量注塑件进行工业化生产的过程中,存在部件尺寸的相互误差,会使上述密封存在不确定性,密封变得不完全可靠,如此会使注射筒前端内腔的空气压缩度降低,空气压强减小,不能实现针座被弹射回缩;②、该方案中,针座下部凸起形成的是限位座,仅是与密封垫配合,完成针座与注射筒内壁之间的 ...
【技术保护点】
改进型正压回缩式安全注射器,由护套(0)、密封垫(01)、针管(1)、针座(2)、阻尼圈(3)、活塞(4)、推杆(5)、外筒(6)共同组成;其特征在于:针座(2)前段(21)的外表与外筒(6)前端锥头内孔(61)之间设置有密封垫(01),使针座前段(21)与中段(22)结合处与外筒(6)前端锥头内孔(61)形成气密封;阻尼圈(3)套装在针座(2)后段的下端并将其底部的呈喇叭形扩展的锐利裙边(24)完全包裹,然后一同安装在外筒(6)的前端内腔(63)中,使针座(2)、阻尼圈(3)、外筒(6)之间形成气液密封,也使外筒前段(63)的空间完全封闭;活塞(4)为帽状结构,其上端表面有一环形沟槽(41),其侧面有两个环形凸起(42),环形凸起(42)的直径略大于外筒(6)的内径,活塞(4)安装在推杆(5)的前端外侧,推杆(5)及活塞(4)安装在外筒(5)内腔,活塞(4)与外筒(6)内壁之间呈滑动紧密配合。
【技术特征摘要】
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