Patent ID: 8740924
Filing Date: 2014-06-03
Classification: A61B

Abstract:
1. A safe simple disposable automatic blood lancet, comprising: a casing, the casing forming an ejection cavity, the casing having a pinhole at one end thereof; a lancet core that elongates along an X direction defined as an axial direction, the lancet core being arranged inside the ejection cavity and having at one end thereof a protective bar, one end of the protective bar protruding out of the pinhole of the casing; and a spring, the lancet core being provided with a needle therein, a needle point of the needle being located inside the protective bar and oriented towards the pinhole; the protective bar and the lancet core being connected by muff-coupling or via a neck that can be twisted broken to enable a demountable connection; and the spring being arranged at the other end of the lancet core, thus forming an ejection structure with which the spring can push the lancet core to move; a part of the casing extending into the ejection cavity to form a flexible arm used for locking the lancet core; and the lancet core being provided with a bayonet corresponding to the flexible arm, the flexible arm being configured to engage at an end thereof with the bayonet, thus forming a locking structure in a ready-for-ejection state upon the lancet core compressing the spring; the casing being provided with a trigger button, the trigger button being formed by an extension of the casing or an independent member mounted on the casing; and the trigger button being provided with a push arm, the push arm transversely passing through the ejection cavity to get close to or in touch with the end of the flexible arm, thus forming a push-type trigger structure; and the trigger button being provided on the push arm with a barb; the casing being provided with a self-locking barb corresponding to the barb and being located in a downward path of the barb, thus forming a self-locking structure upon the barb being engaged with the self-locking barb after the trigger button is pushed once; wherein: the ejection cavity encloses a space that allows the push arm to move downwards along a Z direction that is perpendicular to the X direction; the space being 3-dimensional and extending in the X direction, the Z direction, and a Y direction that is perpendicular to the X and Z directions, and the protective bar is provided with a safety action portion at the other end thereof that is inside the ejection cavity; with the protective bar assembled, the safety action portion occupies the space in the X, Y or Z direction or simultaneously in arbitrary two of the X, Y and Z directions, and prevents the push arm from moving downwards to drive the barb to be self-locked with the self-locking barb; with the protective bar disassembled, the safety action portion withdraws from the space and allows the push arm to move downwards to drive the barb to be self-locked with the self-locking barb; and thus a safety structure of the trigger button is formed.