Plastic device for injection and obtaining blood samples

Claim 1

A plastic injection device comprising: a. an elongate, exterior hollow barrel; b. a hollow, cylindrically-shaped depth gage means having a rearward end slidably received within the forward end of the exterior barrel such that the forward end of the depth gage means protrudes from the barrel; c. a cylindrically-shaped spring loaded firing barrel, including first spring loading means positioned at the rearward end of the exterior barrel for projecting the firing barrel forward, the spring loading means of the firing barrel being axially disposed between the firing barrel and the exterior barrel; d. an inwardly biased, spring loaded sleeve, including second spring loading means, said sleeve being mounted rearwardly and within the exterior barrel, the forward end of the firing barrel when cocked, resting on the said sleeve; e. an inwardly moveable firing button mounted on the exterior barrel for biasing the spring loaded sleeve outwardly against the force of the second spring loading means, the firing button being positioned opposed to the second spring loading means of the said sleeve; f. striker holder means mounted at the rearward end of the firing barrel for removeable attachment with a lancet striker means; g. spring loading means to maintain a lancet striker under tension on the striker holder means; and, h. a lancet module removably mounted at the forward end of the depth gage, the module comprising a rearwardly biased lancet holder, including a spring biasing means adapted to support a removeable lancet mounting and attached lancet; whereby: i. when the firing barrel is retracted against the force of the first spring loading means, it rests in a cocked position, on the spring loaded sleeve; ii. when the firing button is depressed inwardly, it outwardly biases the spring loaded sleeve and dislodges the firing barrel and thereby projects the lancet striker through the exterior barrel and depth gage to impact the lancet module against the force of the lancet spring biasing means, and thereby projects the lancet module forwardly and punctures a user's skin with the lancet; iii. the depth gage aligns the striker as it passes therethrough and adjusts the puncture depth of the lancet needle.