Patent ID: 6986777

Claim:
An automatic lancing device for withdrawing a blood sample, comprising: a hollow cylindrical body; an operation mechanism having a lancet exchangeably fitted at the front of a lancet holder positioned inside the body, and an impact-receiving member combined with the other side of the lancet holder and receiving impact to eject the lancet from the body; an impact-generating mechanism having an impact-transmitting member positioned at a back end of the operation mechanism and transmitting impact to the impact-receiving member, wherein the impact-generating mechanism includes: a pushing member being positioned at the back end of the body and having pin-operating holes which penetrate across it; the impact-transmitting member having a penetrating hole and inner-inserted inside the pushing member, wherein a first elastic member is also inner-inserted inside the pushing member and interposed between the impact-transmitting member and the pushing member; a pin guide member having pin guide holes penetrating across it and located outside the pushing member, wherein a second elastic member is also located outside the pushing member and interposed between the pin guide member and the pushing member; and an operating pin passing through the penetrating holes of the impact-transmitting member, the pin-operating holes of the pushing member and the pin-guide hole of the pin guide member and connecting these members; wherein each of the pin guide holes has a circumferential path and a longitudinal path; the operating pin located at the circumferential path is moved into the longitudinal path by the pin-operating hole when the pushing member is pushed; and the impact-transmitting member is moved forward with the operating pin according to the longitudinal path due to the first elastic member storing elasticity while the operating pin is being moved, and transmits impact into the impact-receiving member; and a length-regulating mechanism comprising a length-regulating member rotationably combined with the outer circumference of a front case enclosing the lancet at the front end of the body and regulating an ejection length of the lancet from the front case.