the general construction of the preferred embodiment appears in fig9 a and 9b . there it will be seen that the adjustable disposable lancet 10 has a body portion 11 with a protective cap 12 having an internal needle protector 13 secured over the end . the selector tip 18 ( fig9 b ) is rotated until the depth positioning pointer 25 identifies the particular depth preselected . the selector tip 18 has a needle opening 19 which receives the needle 21 of the lancet 20 . the side view of fig9 b does not show the printed indicia or the pointer and it will be seen that the bottom end is uninterrupted . as shown in fig1 , the contact pad 29 is on the end of the selector tip 18 . the indicia is preselected by the depth positioning pointer 25 and the depth numbering 26 is shown on top of the body of the adjustable disposable lancet 10 . fig1 is a reverse view of that shown in fig1 , differing only in that it does show the bottom to be uninterrupted . in usage , the adjustable disposable lancet 10 is quite simplistic . as shown in fig1 - 13 , the protective cap 12 is first removed from the adjustable disposable lancet 10 . thereafter , the selector tip 18 is rotated until the preselected notch is identified by the depth positioning pointer 25 . the depth numbering 26 is employed as a guide , but it is actually the depth positioning pointer 25 which identifies the position notches 28 on the dial 51 . the specific structure is shown in exploded perspective in fig1 . beginning at the lower left hand corner of fig1 it will be seen that the protective cap 12 is positioned over the selector tip 18 . in turn , the selector tip 18 fits within the body portion 11 . the body portion 11 , as shown , has an extended depth positioning pointer 25 which will be described hereinafter . the depth positioning pointer 25 extends from the body portion 11 . the selector tip 18 receives the lancet 20 from which the needle 21 extends at one end . spaced from the needle is the locking ring 23 which helps the securement of biasing means comprising the coil spring 15 at one of its ends 16 to the lancet 20 . the lower spring end 16 of the coil spring 15 is positioned to coaxially engage the disabling tines 45 . the latch means or latches 44 are opposed and engage the spring lock groove 22 defined by the locking ring 23 of the lancet 20 . as to the disabling tines 45 , it will be noted that there is a long tine tip 45 and a short tine tip 46 . the longer of the tines tip 45 , particularly as shown in fig2 , has its end cocked slightly inwardly , as will be described hereinafter . the space 38 between the tines 45 , 45 comprises guide means for the lancet 20 . in greater detail , as to the specific structure which dictates the function and method of the subject adjustable disposable lancet , fig1 shows the principal elements of fig1 but in great detail . the details will be described proceeding from the selector tip 18 which appears in the upper right - hand corner of fig1 , downwardly through the depth positioning pointer 25 , and thereafter to the lancet 20 , and finally the mounting of the lancet 20 in the lancet holder 40 . more specifically , it will be seen that the selector tip 18 has a plurality of selector knobs 56 underneath the contact pad 29 . these selector knobs 56 are proportioned to click into the mating selector grooves 58 located in the depth positioning pointer 25 which is shown immediately beneath the selector tip 18 in fig1 . in addition , the action of a cam and follower comprising means interconnecting between the barrel and selector tip for adjusting the total length of the barrel , and selector tip includes the bayonet type helical recess 60 located in the lower barrel portion 61 of the selector tip 18 and the co - action between the cam follower pin 31 when it enters the slot of the bayonet type helix 60 moves the contact pad 29 upwardly or downwardly between the three positions . in so moving , the selector knobs 56 will selectively engage the recessed selector grooves 58 and in the process not only lockingly and removably securing the selector tip 18 internally of the depth positioning pointer 25 but also emitting an audible click each time the contact pad 29 is rotated between the three positions selected . the specific details will be better understood now as we sequence through fig1 , 18 , 19 and 20 . beginning with fig1 , it shows the adjustable disposable lancet 10 as received by the user , with the protective cap 12 removed since the cap does figure into the action but rather serves to protect and enclose the unit for shipment , storage in the clinical facility , and sterility until actual use . as seen in fig1 , prior to usage the lancet needle 21 and lancet 20 are lockingly engaged by the disabling tines 45 , 45 and more specifically the tine tips 46 , 49 at the end portion of the disabling tines 45 , 45 . in accordance with the invention , it will be noted that one of the tines 45 is longer than the other tine 45 . this tine length differential structure eliminates the possibility of re - inserting the lancet correctly after a single use , thereby comprising means for preventing recocking of the lancet 20 after it has been fired . therefore , it will be seen that in fig1 the contact pad 29 , at the lower portion fig1 shows the lancet in the fully extended position , at which time the coil spring 15 has gone from the compression mode as shown in fig1 to a tension mode as shown in fig1 . it will be appreciated that this modal change of the coil spring 15 is virtually instantaneous and not observable . nonetheless the coil spring 15 is so formed proportioned and of a metallic specification that permits the employment in a compression , as well as tension mode . at the time of the total penetration of the lancet needle 21 , as shown in fig1 , it will be seen that the tines 45 and 45 in the lancet holder 40 are spread apart defining a tine slot 38 , but the longer tine 45 has an offset in - portion which will be described hereinafter . turning now to fig1 , this is the configuration as the lancet 20 and its associated needle 21 is retracted during the after firing tension mode of the coil spring 15 . as will be seen , the spring pulls on the groove 22 on the lancet 20 to yieldably urge the lancet 20 back into position in the tine slot 38 on the two disabling tines 45 , 45 . as shown in fig2 , any return to a re - cocked position is frustrated by the long tine tip 45 and more particularly its end which is curved centrally , and therefore engages any portion of the i - beam like construction 36 of the lancet 20 which might try to bring the lancet base back between the tines 45 , 45 in the tine slot 38 to the firing configuration , as shown in fig1 . in this fashion the lancet is prevented or frustrated from being repositioned over the tine members 45 , 45 , and reused . lockingly engaging the i - beam like construction 36 base of the lancet 20 in a pair of latches 44 , and centrally positioning adjacent a pair of support tines extending upwardly from the base 41 of the lancet holder 40 . important to the invention is providing a latching means for the lancet in which the latching is conducted primarily by a pair of opposed locking and disabling tines . one of the tines 45 is longer than the other tine 45 . this permits one of the longer tines 45 to be curved centrally so that upon the potential return of the lancet , that particular tine will engage the lancet much as shown fig2 of the accompanying drawings . a dotted circle has been set on the position on fig2 , and fig2 is a showing , in enlarged relatively diagrammatic form , how the longer of the tines 45 has its bent tip 49 and the same engages any lower portion of the lancet 20 . the sequence of the method involves pre - selectively assembling all of the members at the factory site , and in such a fashion that the lancet 20 is cocked for usage , primarily as shown in fig1 . thereafter the lancet contact pad 29 is rotatably adjusted to a predetermined position of the selector 50 which has selector knobs 56 which engage selector grooves 58 respectively on the selector tip 18 and inside of the lancet barrel - 30 to thereby determine the extent to which the contact pad 29 extends from the main body portion of the disposable lancet . as set forth hereinabove , it is the utilization of the contact pad 29 by its spacial relationship from the balance of the unit which determines the extent of penetration of the lancet needle . the lancet needle 21 and the lancet 20 are always positioned in exactly the same location relative to the adjustable disposable lancet 10 . more specifically , the body and all other elements are fixed . the depth numbering 26 indicates the extent to which the lancet body will be moved when it is fired , as shown in fig1 . no other element of the unit determines this position other than in their coordinated and cooperative relationship each to the other . the space 38 between the tines 45 , 45 comprises guide means for the lancet 20 , comprising means interconnecting between the barrel and selector tip for adjusting the total length of the barrel , and selector tip includes also , in accordance with the invention , provision is made for a needle travel stop 32 . the needle travel stop 32 is important in that it stops the penetration of the lancet 20 at a given point relative to the depth positioning pointer 25 . as described earlier , the extent of penetration of the needle 20 is not a function of the positioning of the lancet . the lancet always positively engages the slide needle travel stop 32 and it is therefore the position of the selector tip 18 and it associated contact pad 29 that determine the penetration of the needle when the lancet is fired . turning now to fig1 , it will be seen that lancet barrel 30 houses the follower pin 31 and includes a needle travel stop 32 , shown in phantom lines towards the upper portion of the barrel 30 . detents 34 are provided inside the barrel 30 . continuing now , we skip to the lancet holder 40 . as shown , the lancet holder 40 has a base portion 41 . in addition , the lancet holder base 41 has basically an i - beam like construction 36 which permits it to be oriented into the lancet holder 40 , as will be described hereinafter . the lancet holder 40 includes a pair of opposed latches identified as reference numeral 44 . these latches 44 co - act with the locking ring 23 on the lancet 20 and co - act with the coil spring 15 in the compressed configuration when the lancet is set to fire . the specific details will be better understood now as we sequence through fig1 , 18 , 19 and 20 . beginning with fig1 , it shows the adjustable disposable lancet 10 as received by the user , with the protective cap 12 removed since the cap does figure into the action but rather serves to protect and enclose the unit for shipment , storage in the clinical facility , and sterility until actual use . as seen in fig1 , prior to usage the lancet needle 21 and lancet 20 are lockingly engaged by the disabling tines 46 and more specifically the tine tips 48 , 49 at the end portion of the disabling tines 46 . in accordance with the , invention , it will be noted that one of the tines 46 is longer than the other tine 45 . this tine length differential structure thereby comprising means for preventing recocking of the lancet 20 after it has been fired . therefore , it will be seen that in fig1 the contact pad 29 , at the lower portions thereof , is positioned with respect to the holder body by means of the position of the helix 55 and the helical engaging cam follows pin 31 . fig1 shows the lancet in the fully extended position , at which time the coil spring 15 has gone from the compression mode as shown in fig1 to a tension mode as shown in fig1 . it will be appreciated that this modal change of the coil spring 15 is virtually instantaneous and not observable . nonetheless the coil spring 15 is so formed proportioned and of a metallic specification that permits the employment in a compression as well as tension mode . at the time of the total penetration of the , lancet needle 21 , as shown in fig1 , it will beseem that the tines , 45 and 46 in the lancet holder 40 are spread apart defining a tine slot 38 , but the longer tine 45 has an offset in - portion which will be described hereinafter . turning now to fig1 , this is the configuration as the lancet 20 and its associated needle 21 is retracted during the after firing tension mode of the coil spring 15 . as will be seen , the spring pulls on the groove 22 on the lancet 20 to yieldably urge the lancet 20 back into position in the tine slot 38 on the two disabling tines 46 . as shown in fig2 , any return to a re - cocked position is frustrated by the long tine tip 46 and more particularly its end which is curved centrally , and therefore engages any portion of the i - beam like construction 36 of the lancet 20 which might try to bring the lancet base back between the tines 45 , 46 in the tine slot 38 to the firing configuration , as shown in fig1 . in this fashion the lancet is prevented or frustrated from being repositioned over the tine members 45 , and reused . the method of the present invention involves the constraint of a lancet interiorly of a disposable lancet device . the sequence of the disposition of the lancet involves positioning a spring coaxially around the lancet base , and thereafter lockingly engaging the i - beam like construction 36 base of the lancet 20 in a pair of latches 44 , and centrally positioning adjacent a pair of support tines extending upwardly from the base 41 of the lancet holder 40 . important to the invention is providing a latching means for the lancet in which the latching is conducted primarily by a pair of opposed locking and disabling tines . one of the tines 46 is longer than the other tine 45 this permits one of the longer tines 46 to be curved centrally so that upon the potential return of the lancet , that particular tine will engage the lancet much as shown fig2 of the accompanying drawings . a dotted circle has been set on the position on fig2 , and fig2 is a showing , in enlarged relatively diagrammatic form , how the longer of the tines 45 has its bent tip 49 and the same engages any lower portion of the lancet 20 . the sequence of the method involves pre - selectively assembling all of the members at the factory site , and in such a fashion that the lancet 20 is cocked for usage , primarily as shown in fig1 . thereafter the lancet contact pad 29 is rotatably adjusted to a predetermined position of the selector 50 which has selector knobs 56 which engage selector grooves 58 respectively on the selector tip 18 and inside of the lancet barrel 30 to thereby determine the extent to which the contact pad 29 extends from the main body portion of the disposable lancet . as set forth hereinabove , it is the utilization of the contact pad 29 by its spacial relationship from the balance of the unit which determines the extent of penetration of the lancet needle . the lancet needle 21 and the lancet 20 are always positioned in exactly the same location relative to the adjustable disposable lancet 10 . more specifically , the body and all other elements are fixed . the depth numbering 26 indicates the extent to which the lancet body will be moved when it is fired , as shown in fig1 . no other element of the unit determines this position other than in their coordinated and cooperative relationship each to the other . in summary , what has been shown and described is an adjustable disposable lancet 10 . also shown and described is a method of utilization of an adjustable disposable lancet . while the method is dictated to a degree by the apparatus , the apparatus is also dictated by the method . in that respect , the method is specific to the utilization of the pad portion of a disposable lancet which contacts the body to determine the extent to which the lancet needle penetrates . conversely , the structure of the body is such as to have a holding means for the lancet which has one end portion in interference relationship with the base of the lancet . due to the interference relationship , while the lancet is properly oriented on top of the holding tines with the spring in compression prior to usage , once the lancet has been fired the holding tines will return to their original configuration with the longer of those tines 46 extending centrally 49 to thereby block any attempt to return the lancet to a cocked position . it will be understood that various changes in the details , materials and arrangements of parts , or method which have been herein described and illustrated in order to explain the nature of the invention , may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims .