Abstract:
A pricking device having an accurate pricking function, an automatic safe post-use discarding function and a re-use inhibiting function is disclosed. The pricking device is easy and simple to operate, simple in structure and is high in productivity to reduce production costs. The pricking device is made up of a lancet unit and a housing unit. The lancet unit includes a needle. The lancet unit is formed by a unit body member, a restoration member and a resilient piece for lock molded as one with one another. The unit body member operates to cause the needle to pop out from the housing unit in connection with a pricking operation. The restoration member controls the operation of movement of the unit body member as it stores a force of elasticity in it. After the pricking operation, the needle is returned into the inside of the housing unit under the so stored force of elasticity of the restoration member. Another force of elasticity is stored in the resilient piece for lock as a result of the movement of the unit body member. The resilient piece for lock includes a cam bump engaged with a lock cam section of the housing unit after the pricking operation.

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
       [0001]    The present application claims priority to Japanese Priority Patent Application JP 2008-330679 filed in the Japan Patent Office on Dec. 25, 2008, the entire content of which is hereby incorporated by reference. 
       BACKGROUND 
       [0002]    The present disclosure relates to a disposable pricking device used for example in sampling a minor quantity of blood from e.g. a finger&#39;s tip. 
         [0003]    The pricking device is used in a medical site, such as a hospital, a clinic or caring facilities in carrying out an inspection for a blood sugar value for indefinite numbers of patients or test subjects. Such inspection is by sampling minor quantities of blood from e.g. their finger tips. A large variety of the pricking devices are presently sold on the market. The pricking device is required to be used once for all in view of healthcare and from consideration of sanitation. Moreover, since the device has a pricking needle, the device is to be made disposable in safety. 
         [0004]    [Patent Publication 1] Japanese Patent Application Publication No. 2007-196010 
         [0005]    [Patent Publication 2] Re-published International Patent Application Publication No. WO97/04707 
         [0006]    A pricking device, now offered to the market, is made up of a lancet structure and a casing member. The lancet structure is mounted within the casing member for movement therein. The lancet structure is made up of a so-called lancet and a separate resilient member (spring) formed of metal or a resin. The lancet is molded from a single resin material with a pricking needle (needle) buried therein. The separate resilient member is assembled to this lancet either by a manual operation or with an automatic assembling system to complete the lancet structure. 
         [0007]    With this type of the pricking device, the spring that forms a part of the lancet structure is formed of metal or resin. With the pricking device, employing the metal spring, such metal spring is desirable to be provided as a separate member, thus incurring the cost for provision and for the spring material. This type of the pricking device is not desirable in case the pricking device is to be made disposable from hygienic reasons. 
         [0008]    In addition, with the above sort of the pricking device made up of the lancet structure including the spring and the casing member, not only the number of component parts is increased to raise the production cost, but also the number of assembling process steps is increased to raise the assembling cost. With the above sort of the pricking device, it may be considered to automate the assembling process to lower the assembling cost. However, such automation of the assembling process may be difficult in view of low assembling performance ascribable to the use of a resilient member or of difficulties inherent in the automation of the assembling process. 
         [0009]    That is, the resilient member used in a conventional pricking device is in the form of bellows or coils. If larger numbers of these bellows or coils are used, they may be entangled with one another. It is thus necessary to disentangle them into separate parts by a labor-consuming operation. However, in the disentangled state, it is rather difficult to keep the separate parts in the so disentangle state. Moreover, when gripped, the separated bellows or coils tend to be deformed to deteriorate handling or positioning characteristics. Thus, in automatically assembling these resilient components to form a pricking device, the components are desirable to be stored in order in a delivery device annexed to an assembling line. The components, thus stored, are then delivered accurately automatically one by one and assembled in position using e.g. a handling means, by an extremely difficult operation. 
         [0010]    The above sort of the pricking device has so far been assembled by a manual operation. This however has presented a problem that productivity may not be improved because of difficulties encountered in handling the resilient members. Since the pricking device is prepared by a manual assembling operation, it is necessary to provide a transfer step as well as a sterilizing or cleaning process between different process steps with consequent rise in production costs. In addition, since the pricking device is larger in size, the production costs are raised in connection with packaging, transport or reservation. 
         [0011]    Moreover, with the pricking device employing resilient members in the form of bellows or coils, the pricking operation is carried out against the biasing force of the resilient members. After the end of the pricking, a user releases his/her hand from the lancet structure to retract the pricking needle into the inside of a casing under the force of elasticity stored in the resilient members. The bias force of the resilient members, thus released from the finger pressure, produces an attenuating vibration. However, in the course of the attenuating vibration, the pricking device may prick a plural number of times, specifically, twice or even three times, which is not desirable from the medical point of view. 
         [0012]    Therefore, it is desirable to provide a pricking device that has an accurate pricking function, an automatic safe post-use discarding function and a re-use inhibiting function and that is easy and simple to operate, simple in structure and high in productivity to reduce production costs. 
       SUMMARY 
       [0013]    In one embodiment, a pricking device comprises a lancet unit formed as one with a needle, and a housing that houses the lancet unit for movement therein. The lancet unit includes a unit body member movable within the housing in connection with a pricking operation to cause the needle to pop out of the housing, and a resilient piece. The resilient piece, formed as one with the unit body member, includes a cam bump that may be engaged with a cam groove formed in the housing. The resilient member stores a first force of elasticity as the unit body member is moved in connection with the pricking operation. The cam bump engages within a foremost part of the cam groove when the unit body member has returned into the housing after the pricking operation. The cam bump is kept engaged within the foremost part of the cam groove under the first force of elasticity stored in the resilient piece to keep a state of inhibiting re-popping out of the needle. The unit body member or the housing includes a restoration member that stores therein a second force of elasticity as the unit body member is moved in connection with the pricking operation. The restoration member causes the needle to be returned into the inside of the housing under the second force of elasticity after the pricking operation. 
         [0014]    The pricking device according to an embodiment is made up of a lancet unit and a housing. The lancet unit is formed by a unit body member having a needle and a resilient member, which is formed as one with the unit body member. The restoration member is provided on the unit body member or on the housing. The number of component parts is reduced and the structure is simplified to improve the productivity as well as to reduce the device size and costs. In addition, the operation of the device may be simplified. With the pricking device according to an embodiment of the present invention, in which there is provided the restoration member that stores the second force of elasticity in connection with the operation of movement of the unit body member, the unit body member may automatically be returned into the housing member after the pricking operation to provide for improved operability and safety. With the pricking device according to an embodiment of the present invention, in which there is provided the resilient piece that stores the first force of elasticity in connection with the operation of movement of the unit body member. Hence, the unit body member may be retained in the returned state in the housing after the pricking operation. In addition, the re-popping out of the pricking means may be inhibited so that faulty operations may be prevented from occurring to assure improved safety. 
         [0015]    Additional features and advantages are described herein, and will be apparent from the following Detailed Description and the figures. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0016]      FIG. 1  is a perspective view showing a pricking device of a first embodiment, with a housing unit being shown in a developed state. 
           [0017]      FIG. 2  is a perspective view showing the pricking device before use. 
           [0018]      FIG. 3  is a perspective view showing a lancet unit of the pricking device. 
           [0019]      FIG. 4  is a perspective view showing a housing unit of the pricking device. 
           [0020]      FIG. 5  is a front view showing an initial stage of thrusting of an actuation plate, for illustrating the method of using the pricking device. 
           [0021]      FIG. 6  is a front view showing a state where a needle is about to be protruded from the housing unit in the course of the pricking operation. 
           [0022]      FIG. 7  is a front view showing the state directly following the end of the pricking operation. 
           [0023]      FIG. 8  is a front view showing the stage when the pricking operation has been finished and the lancet unit is re-accommodated within the housing unit. 
           [0024]      FIG. 9  is a perspective view of a pricking device provided with a lancet pop-out adjustment mechanism according to a second embodiment. 
           [0025]      FIG. 10  is a perspective view of a pricking device having a lancet unit according to a third embodiment. 
           [0026]      FIG. 11  is a perspective view looking from the reverse side of the main housing unit of the pricking device shown as a third embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0027]    A pricking device  1 , shown in the drawings as an embodiment, will now be described in detail with reference to the drawings. 
         [0028]    &lt;Global Configuration&gt; 
         [0029]    The pricking device  1  is made up of a lancet unit  2  described later in detail and a housing unit  3 , as shown in  FIGS. 1 to 3 . The housing unit  3  is composed of a main housing member  20  and an upper plate  21 . For measurement of a blood sugar value or discrimination of a blood type, a needle  4  (see  FIG. 3 ) provided on the lancet unit  2  is popped out of the housing unit  3  to prick the finger&#39;s end of a test subject to sample a minor quantity of blood from the so pricked site. In the following description, the expression ‘left’, ‘right’, ‘front’ or ‘reverse’ is to be construed using  FIG. 1  as a reference. 
         [0030]    The pricking device  1  presents an appearance shown in  FIG. 2 . If once the device is used for pricking, the re-popping out of the needle  4  is to be inhibited. Also, the device is to be discarded as the needle  4 , once popped out, is housed in a safe condition within the housing unit  3 , in a manner which will be explained below in more detail. It should be noted that, although the pricking device  1  shown here by way of an embodiment is of the type in which the needle  4  is popped to prick the finger&#39;s end, for example, of the test subject, the present invention is not to be restricted to such device type. For example, the needle  4  may be replaced by a blade that may be protruded out of the housing unit  3  to slightly cut the skin. 
         [0031]    With the pricking device  1 , the lancet unit  2  excluding the needle  4 , the main housing member  20  of the housing unit  3 , and the upper plate  21 , are molded as respective separate components from synthetic resin materials. These synthetic resin materials may be exemplified by L-LDPE (low density linear polyethylene resin), POM (polyacetal resin), PBT (polybutylene terephthalate resin), polyamide resin or polycarbonate resin. The pricking device  1  is to be designed and constructed so that its various component parts will perform elastic displacement or sliding movement or will undergo breaking in a manner that will be described subsequently. Moreover, the device has to be sterilized in its entirety. Hence, the pricking device  1  is preferably formed of a material that has high elasticity, high toughness, a low frictional coefficient characteristic and high resistance against the processing for sterilization. Preferably, the lancet unit  2  and the housing unit  3  are molded from L-LDPE and polypropylene, respectively. 
         [0032]    &lt;Lancet Unit&gt; 
         [0033]    The lancet unit  2  of the pricking device  1  is in the form of a vertically elongated plate having two narrowed-down sites along the height-wise direction (length-wise direction), as shown in  FIGS. 1 and 4 . Specifically, the lancet unit  2  includes a unit body member  5  made up of an upper part  5 A, a mid part  5 B and a lower part  5 C. The upper part  5 A is downwardly arrow-shaped and has its lowermost end delimited by a first narrowed-down section. The mid part  5 B, substantially in the form of a hexagon, is contiguous to the lowermost end of the upper part  5 A and delimited by the first and second narrowed-down sections. The lower part  5 C, substantially in the form of an isosceles triangle, is contiguous to the lowermost end of the mid part  5 B, and has its upper end delimited by the second narrowed-down section. 
         [0034]    The unit body member  5  forms the basic member that goes to make up the lancet unit  2 . In addition, an actuation plate  6  is formed as one with the upper part  5 A, and left and right pair unit body member controlling sections  10 L,  10 R are also formed as one with the upper part  5 A. These controlling sections are collectively termed a unit body member controlling section  10 , unless they are to be referred to as separate sections. The mid part  5 B of the unit body member  5  of the lancet unit  2  is formed as one with left and right pair restoration members  11 L,  11 R that extend from the site of contiguity of the mid part to the upper part  5 A and that act as a first resilient means. These restoration members are collectively termed a restoration member  11  unless they are to be referred to as separate sections. 
         [0035]    The lower part  5 C of the unit body member  5  of the lancet unit  2  is formed as one with front and reverse pair guide ribs  12 A,  12 B and left and right pair resilient pieces for lock  13 L,  13 R. The front and reverse pair guide ribs  12 A,  12 B are collectively termed a guide rib  12  unless these pair guide ribs are to be referred to as separate sections. The left and right pair resilient pieces for lock  13 L,  13 R acting as a second resilient means are referred to as a resilient piece for lock  13 , unless these pair restoration members are to be referred to as separate sections. The needle  4  is buried as one with and in the bulk of the unit body member  5 , as shown in  FIG. 3 . The needle is so buried in the unit body member  5  for extending along substantially the entire length of the unit body member  5 . The needle  4  of the lancet unit  2  is molded as one with and in the bulk of the unit body member  5  so that its lower end is projected out of the lower part  5 C of the unit body member  5 . The projected portion of the needle  4  is sealed by a lancet cover member  14  formed as one with the unit body member  5 . 
         [0036]    &lt;Unit Body Member&gt; 
         [0037]    The actuation plate  6  of the unit body member  5  is formed as a horizontally elongated rectangular plate shaped member having a cross-section larger than that of the upper end of the upper part  5 A. The actuation plate  6  is thrust during the pricking operation as later explained so as to cause downward movement of the unit body member  5  within the inside of the housing unit  3 . The actuation plate  6  having a large surface improves the ease in the pricking operation. In addition, the actuation plate  6  abuts against the upper surface of the housing unit  3  to act as a stopper to inhibit an excess thrusting operation. The unit body member  5  is formed with opening windows  17 A,  17 B and  17 C at the mid portions of the upper part  5 A, mid part  5 B and the lower part  5 C, respectively. These opening windows serve for holding the needle  4  and for effecting needle position registration at the time of molding the lancet unit  2 . 
         [0038]    The unit body member controlling section  10  of the unit body member  5  is formed as one with and protruding from both side edges of the upper part  5 A at a preset distance from the actuation plate  6 . The unit body member controlling section  10  includes left and right pair controlling resilient pieces  22 L,  22 R and left and right pair controlling convexed wall sections  24 L,  24 R. The pair controlling resilient pieces  22 L,  22 R, provided on the lancet unit side, are collectively termed a controlling resilient piece  22 . The left and right pair controlling convexed wall sections  24 L,  24 R, provided on the housing unit side for facing the controlling resilient piece  22 , are collectively termed a controlling convexed wall section  24 . Before use of the lancet unit, the controlling resilient piece  22  of the unit body member controlling section  10  is positioned within a lancet accommodating void portion  23  of the housing unit  3 , specifically, in a void portion delimited between the inner peripheral surface of an upper wall section  20 B of the housing unit  3  and the controlling convexed wall section  24 . When the pricking operation has been performed, the controlling resilient piece  22  is resiliently displaced to ride over an end of the controlling convexed wall section  24  so as to be moved to below the controlling convexed wall section  24 . As the controlling resilient piece  22  of the unit body member controlling section  10  is disengaged from the state of retention by the controlling convexed wall section  24 , there is produced a change in the force of thrust applied to the actuation plate  6  to impart a sense of ‘click’ to a user. The spacing between the unit body member controlling section  10  of the unit body member  5  and the actuation plate  6  prescribes the range of movement of the unit body member  5  in the vertical direction within the housing unit  3  in the initial state. 
         [0039]    The lower edge of the upper part  5 A of the unit body member  5  is inclined gradually downwards to approach to the center side so as to be contiguous to the mid part  5 B via the narrowed-down site. The restoration member  11  comprised of a cantilevered piece is formed as one with and projecting outwardly curvilinearly from the lower edge of the upper part  5 A. With the lancet unit  2  housed within the housing unit  3 , the restoration member  11  is extended towards the housing unit  3 , with the foremost part of the restoration member  11  protruding further outwards than the unit body member controlling section  10 . The foremost part of the restoration member  11  rests against guide wall sections  25 L,  25 R each having a smoothed mating surface. These guide wall sections are collectively termed a guide wall section  25 . 
         [0040]    When the unit body member  5  is moved downwards to perform the pricking operation as later described, the restoration member  11  has its mid portion resiliently displaced due to its reduced thickness and material characteristics. Thus, a force of elasticity is stored therein to control the movement of the unit body member  5 . After termination of the pricking operation, the unit body member  5  is moved upwards, by way of a restoration operation, under the force of elasticity stored in the restoration member  11 . 
         [0041]    The mid part  5 B of the unit body member  5  presents the above mentioned hexagonal shape, and has its lower end contiguously connected via a narrowed-down portion to the lower part  5 C. The hexagonal shape is such a one in which the mid part  5 B is gradually laterally inclined from the above mentioned connection site of the narrow width in transitioning downwards so as to form an inclined lateral side or edge that faces the restoration member  11 . The mid part  5 B then forms a vertically extending side edge to form the hexagonal shape. The lower part  5 C of the unit body member  5  has its lateral side or edge inclined gradually laterally in transitioning downwards so as to form the above mentioned substantially isosceles triangle. The lower part  5 C delimits left and right free void areas for displacement  15 L,  15 R between it and the mid part  5 B to allow for elastic displacement therein of the resilient piece for lock  13 . The free void areas for displacement  15 L,  15 R are collectively termed a free void area for displacement  15 , unless they are to be referred to as separate sections. 
         [0042]    The unit body member  5  has, at its mid portion, a guide rib  12  comprised of a rectangular projection facing both the front and reverse sides. The guide rib  12 , composed of a front side guide rib  12 A and a reverse side guide rib  12 B, is formed as one with the unit body member  5  for extending between the upper part  5 A and the lower part  5 C. When the lancet unit  2  is housed within the housing unit  3 , the guide rib  12  is engaged within a guide cam groove  26  formed in the housing unit  3  side to permit movement of the unit body member  5  in stability during the pricking operation. The unit body member  5  may be improved in its mechanical strength by forming the guide rib  12  with an increased height. 
         [0043]    The resilient piece for lock  13 , which is a cantilevered section, is formed as one with the lower side edge of the lower part  5 C of the unit body member  5  so that the resilient piece for lock  13  faces the restoration member  11 . The resilient piece for lock  13  is extended within the free void area for displacement  15  so that its foremost part will be located laterally outside of the mid part  5 B. The foremost part of the resilient piece for lock  13  is formed as one with a front side cam bump  16 L 1 , a front side cam bump  16 L 2 , a reverse side cam bump  16 R 1  and a reverse side cam bump  16 R 2 . These cam bumps are collectively referred to as a cam bump  16  unless they are to be referred to as separate sections. 
         [0044]    When the lancet unit  2  is housed within the housing unit  3 , the resilient piece for lock  13  faces a lock cam section  28  provided on the housing unit  3  side in a manner which will be explained subsequently. The cam bump  16  is engaged with the lock cam section  28  to provide an automatic lock mechanism. When the lancet unit  2  is moved in the course of the pricking operation, the resilient piece for lock  13  is moved within the free void area for displacement  15  to store a force of elasticity therein. After the pricking operation, the cam bump  16  is moved to a position of engagement with the lock cam section  28  under the force of elasticity stored in the resilient piece for lock  13 . The resilient piece for lock  13  holds the unit body member  5  in a locked state under the force of elasticity stored therein to inhibit the re-pricking operation of the lancet unit  2 . 
         [0045]    In the lancet unit  2 , the needle  4  formed of stainless steel is buried at a mid portion of the unit body member  5 . The needle  4  has its upper end located facing the opening  17 A in the vicinity of the lower edge of the upper part  5 A, while having its lower end protruded a preset length from the lower part  5 C. The lancet unit  2  is molded by a so-called insert molding method according to which a synthetic resin material is injected in a molten state into a cavity of a metal mode as the needle is held in place within the metal mold. Since the needle  4  is molded to a sufficient length as one with and in the inside of the unit body member  5 , the pricking operation may be carried out in a stabilized state without the risk of producing an offset. 
         [0046]    The needle  4  is molded as one with the unit body member  5  so that its foremost part is protruded a preset length out of the housing unit  3  as the lancet unit  2  is moved in the course of the pricking operation. The needle  4 , buried for its substantially entire length at mid portions of the lower part  5 C and the mid part  5 B of the unit body member  5 , performs the role of a sort of a reinforcement bar to contribute to high mechanical strength of the unit body member  5 . 
         [0047]    In the lancet unit  2 , as mentioned previously, the protruded portion of the needle  4  from the unit body member  5  is sealed by the lancet cover member  14  formed as one with the unit body member  5 . The lancet cover member  14  is made up of a shaft-shaped cover  18  and a grip  19 . The shaft-shaped cover  18  seals the needle  4  within the housing unit  3  with the lancet unit  2  housed within the housing unit  3 . The grip  19  is protruded from a lancet pop-out opening  29  formed in the housing unit  3 , as will be explained subsequently. 
         [0048]    In the lancet cover member  14 , the shaft-shaped cover  18  is of an axial length approximately equal to the stroke of movement of the lancet unit  2  prescribed by the above mentioned actuation plate  6  and the unit body member controlling section  10 . The lancet cover member  14  may readily be broken off by the connecting portion of the shaft-shaped cover  18  connecting to the unit body member  5  being reduced in thickness, for instance. In performing the pricking operation described later, the grip  19  of the lancet cover member  14  may be held by hand and twisted to break the shaft-shaped cover  18  at its connecting portion to the unit body member  5  to expose the needle  4 . 
         [0049]    The lancet cover member  14  seals the needle  4  until the time of the pricking operation in order to keep the pricking device  1  in a safe condition. As mentioned previously, the lancet unit  2  is molded with the needle  4  in a sterilized state. This sterilized state of the needle  4  is kept until the time of the pricking operation in order to keep the pricking device  1  in a sanitary condition. 
         [0050]    &lt;Dimensional Prescriptions&gt; 
         [0051]    The dimensional prescriptions of the lancet unit  2  composed of the above mentioned component parts will now be described. It should be noted that the lancet unit  2  is not limited to these dimensional prescriptions. Also, tolerance values are set for the dimensional values. The lancet unit  2  has an overall length of 48.0 mm, with the unit body member  5  being 29.4 mm in length. The unit body member  5  has an overall thickness of 3.0 mm. Since the cam bump  16 , 0.8 mm in height, and the guide rib  12 , 0.8 mm in height, are formed on the resilient piece for lock  13 , the unit body member  5  has a maximum thickness of 4.6 mm. The restoration member  11  has a width of 3.0 mm, a thickness of 0.8 mm and a length of 10.0 mm. The resilient piece for lock  13  is of a width of 3.0 mm, a thickness of 0.8 mm and a length of 9.0 mm. 
         [0052]    Referring to  FIGS. 1 and 2 , the lancet unit  2  constructed as set out above is housed within the housing unit  3  for movement in the up-and-down direction, to constitute the pricking device  1 . In this housed state of the lancet unit  2 , the actuation plate  6  and a portion of the upper part  5 A of the unit body member  5  are protruded from an upper side, while the grip  19  of the lancet cover member  14  is protruded from a lower side. The housing unit  3  is made up of a main housing member  20 , an upper plate  21  and a hinge  21 A interconnecting the main housing member  20  and the upper plate  21 , as shown in  FIGS. 1 and 4 , and is formed of the synthetic resin as is the above mentioned lancet unit  2 . 
         [0053]    Meanwhile, the housing unit  3  is not limited to be formed as a unitary member by having the main housing member  20  and the upper plate  21  interconnected by the hinge  21 A. For example, the main housing member  20  and the upper plate  21  may be separate molded members without using the hinge  21 A. 
         [0054]    When the lancet unit  2  of the above mentioned dimensional prescriptions is housed within the housing unit  3 , and the main housing member  20  is connected to the upper plate  21  to form a unitary structure of the housing unit  3 , the pricking device  1  with a thickness of 6.0 mm, a length of 29.4 mm and a width of 19 mm is formed. When the lancet unit  2  is housed within the housing unit  3  with the grip  19  of the lancet cover member  14  protruded from the main housing member  20  as later explained, the pricking device  1  with an overall length of 48.0 mm is formed. The pricking device  1  is smaller in size and thickness than the above mentioned conventional pricking device. The pricking device  1  outperforms the above mentioned conventional pricking device as to handling such as packaging or transport and as to reduction of costs inclusive of those for management and preservation. 
         [0055]    &lt;Housing Unit 3&gt; 
         [0056]    The main housing member  20  is formed to a substantially rectangular box of a reduced thickness. It has a bottom plate  20 A and outer peripheral wall sections, comprised of an upper surface wall section  20 B, a lower surface wall section  20 C, a left side wall section  20 L and a right side wall section  20 R. These peripheral wall sections are formed for upstanding from and extending along the outer peripheral sides of the bottom late  20 A. These outer peripheral wall sections of the main housing member  20  are of a height slightly larger than the above mentioned thickness of the lancet unit  2 . Thus, the main housing member  20  forms, in conjunction with the upper plate  21 , the lancet accommodating void portion  23  within which the lancet unit  2  may be housed for movement with a certain allowance along the direction of thickness. The lower surface wall section  20 C of the main housing member  20  is slightly arched along the left-and-right direction to conform to the shape of the finger&#39;s tip of a test subject. The position of the pricking device  1  may thereby be kept in a stable condition at the time of pricking of the finger&#39;s tip. 
         [0057]    At a center portion of the bottom plate  20 A of the main housing member  20 , there is formed a guide cam groove  26 B having a length corresponding to the entire length in the height-wise direction. The guide cam groove  26 B forms a guide cam groove  26  in conjunction with a guide cam groove  26 A formed in the upper plate  21  side. The guide cam grooves  26 A,  26 B are collectively termed the guide cam groove  26  unless they are referred to as separate sections. 
         [0058]    When the lancet unit  2  is housed within the housing unit  3 , the reverse surface side guide rib  12 B formed on the unit body member  5  is engaged in the guide cam groove  26 B, whilst the front surface side guide rib  12 B is engaged in the guide cam groove  26 A. The guide cam groove  26 B is formed to a groove width slightly larger than the width of the guide rib  12 B and a length (height) larger than the height of the guide rib  12 B. Thus, in the pricking operation, the guide rib  12 B is allowed to be moved downwards to enable the lancet unit  2  to be moved in stability. 
         [0059]    The lock cam section  28  that forms the automatic lock mechanism is formed on both sides of the above mentioned guide cam groove  26 B of the bottom plate  20 A of the main housing member  20 . The lock cam section locks the resilient piece for lock  13  after the pricking operation in cooperation with left and right pair lock cam sections  28 AL,  28 AR formed on the upper plate  21  side as later described. 
         [0060]    The lock cam section  28  is formed of left and right pair lock cam sections  28 BL,  28 BR. These lock cam sections  28 BL,  28 BR and lock cam sections  28 AL,  28 AR are collectively termed the lock cam section  28  unless they are to be referred to as separate sections. 
         [0061]    In the lock cam section  28 , when the lancet unit  2  is housed within the housing unit  3  following the end of the pricking operation, the reverse side cam bumps  16 L 2 ,  16 R 2 , formed on the reverse side of the unit body member  5 , are engaged with the lock cam sections  28 BL,  28 BR, while the front side cam bumps  16 L 1 ,  16 R 1 , formed on the front side of the unit body member  5 , are engaged with the lock cam sections  28 AL,  28 AR. With the lock cam section  28 , the lock cam sections  28 AL,  28 AR are of the same shape as the lock cam sections  28 BL,  28 BR. In addition, the lock cam sections are in left-right symmetry with respect to each other. Hence, only the sole lock cam section  28  is described with the use of reference numerals used in common with the remaining lock cam sections, and the description of these remaining lock cam sections is dispensed with. 
         [0062]    Referring to  FIGS. 1 and 4 , the lock cam section  28  includes a substantially rectangular cam opening  30 , a cam recess  31 , a cam groove  32 , and a guide cam tongue  33 . The cam opening  30  is formed in the bottom plate  20 A of the main housing member  20  and in the upper plate  21  to a depth that allows for engagement with the cam bumps  16 L,  16 R. The cam recess  31  and the cam groove  32  are contiguous to the cam opening  30 . The guide cam tongue  33  separate the cam recess  31  and the cam groove  32  from each other. In the lock cam section  28 , with the lancet unit  2  housed within the housing unit  3 , the cam opening  30  faces the proximal end of the resilient piece for lock  13  of the unit body member  5 , as shown in  FIG. 1 . The cam opening  30  is formed as a substantially rectangular opening. 
         [0063]    The guide cam tongue  33  is substantially hook-shaped and projected towards the inner side from a mid portion of the upper edge of the cam opening  30  in the lock cam section  28 , as shown in  FIG. 4 . The cam recess  31  and the cam groove  32  are formed towards the lateral side and towards the center of the guide cam tongue  33 . The cam groove  32  of the lock cam section  28  is formed as an inclined cam groove that is progressively laterally inclined towards its foremost part. With the lancet unit  2  housed within the housing unit  3 , the cam bump  16  formed on the unit body member  5  is engaged in the cam groove  32 . In an initial state, the cam bump  16  is engaged in the foremost part of the cam groove  32  of the lock cam section  28 . 
         [0064]    As the lancet unit  2  is moved downwards within the housing unit  3  to perform the pricking operation, the lock cam section  28  causes the cam bump  16  to be moved away from the foremost part of the cam groove  32  into the cam opening  30  to cause resilient displacement of the resilient piece for lock  13 . During the pricking operation, the lock cam section  28  retains the cam bump  16  in the state of engagement in the cam opening  30 . This causes a force of elasticity to be stored in the resilient piece for lock  13 . 
         [0065]    After the pricking operation, the lock cam section  28  produces the operation of restoration of the resilient piece for lock  13  under the force of elasticity stored therein. At this time, the cam bump  16  is moved away from the cam opening  30  so as to be engaged with the cam recess  31  under the action of the guide cam tongue  33 , so that the resilient piece for lock  13  is held at the foremost part of the cam recess  31 . 
         [0066]    The cam recess  31  is formed in the bottom plate  20 A of the main housing member  20  and in the upper plate  21 , as shown in  FIGS. 1 and 4 . The cam recess  31  has its proximal part contiguous to the cam opening  30 , while having its foremost part arched towards the lateral side. As the cam bump  16  is moved away from the cam opening  30  into the cam recess  31  to get to the foremost part of the cam recess  31 , the cam bump  16  of the resilient piece for lock  13  is engaged in the cam recess  31  to lock the resilient piece for lock  13 . After the pricking operation, the cam recess  31  locks the resilient piece for lock  13  in cooperation with the lock cam section  28 . Hence, a re-pricking operation, attempted inadvertently, may be inhibited. 
         [0067]    A guide hole  34  is formed in the upper surface wall section  20 B of the main housing member  20  facing the upper end of the guide cam groove  26 B. The guide hole  34  is larger in cross-section area than the upper part  5 A of the unit body member  5  and smaller in size than the outer dimension of the actuation plate  6  or the unit body member controlling section  10 . The actuation plate  6  is protruded outwards as the lancet unit  2  is housed in the lancet accommodating void portion  23  via this guide hole  34  formed in the main housing member  20 . 
         [0068]    In performing the pricking operation as later described, the guide hole  34  in the main housing member  20  controls the upper part  5 A of the unit body member  5  to cause movement of the lancet unit  2  in stability. The lancet pop-out opening  29  is formed in the lower surface wall section  20 C of the main housing member  20  facing the lower end of the guide cam groove  26 B. 
         [0069]    The lancet pop-out opening  29  is formed to an opening size larger than the cross-section area of the shaft-shaped cover  18  of the lancet cover member  14  and smaller than that of the grip  19 . The lancet pop-out opening  29  is formed at an uppermost site of the arched portion of the lower surface wall section  20 C of the main housing member  20 , that is, a mid portion in the upper surface wall section  20 B. The lancet unit  2  is housed within the lancet accommodating void portion  23  as the proximal end of the grip  19  abuts against the outer surface of the lower surface wall section  20 C and the shaft-shaped cover  18  is fitted in the lancet pop-out opening  29 , as shown in  FIG. 1 . The lancet cover member  14  is broken off at the grip  19  protruded at the time of the pricking operation, so that the foremost part of the needle  4  exposed from the unit body member  5  will pop out via the lancet pop-out opening  29 . 
         [0070]    &lt;Resilient Piece Controlling Section&gt; 
         [0071]    The main housing member  20  is formed as one with resilient piece controlling sections  35 L,  35 R, which are disposed at opposite positions of the left side wall section  20 L and the right side wall section  20 R for facing the restoration member  11 . These resilient piece controlling sections are collectively termed a resilient piece controlling section  35  unless they are referred to as separate sections. The resilient piece controlling sections are of the same symmetrical shape. Hence, only the resilient piece controlling section  35 L provided on the left side wall section  20 L is described with reference to  FIG. 4  with the use of reference numerals used in common with the resilient piece controlling section  35 L. 
         [0072]    The resilient piece controlling section  35  is made up of a guide opening  36  formed in the left side wall section  20 L and a guide wall section  25  bent inwards at a lower opening edge of the guide opening  36 . With the lancet unit  2  housed in the housing unit  3 , the foremost part of the restoration member  11 , formed on the unit body member  5 , faces the guide opening  36 , as shown in  FIG. 1 . 
         [0073]    The guide wall section  25  of the resilient piece controlling section  35  is an upstanding wall section slightly inclined towards the upper surface wall section  20 B. An inner surface of the foremost part of the wall section is substantially arcuate in shape. The guide wall section  25  of the resilient piece controlling section  35  has a smooth receiving surface for extending substantially along the extending direction of the restoration member  11 . 
         [0074]    The guide wall section  25  of the resilient piece controlling section  35  is in sliding contact with the inner lateral side of the restoration member  11  and thus acts as a receiving surface. When the lancet unit  2  has moved more than a preset value, the resilient piece controlling section  35  allows the foremost part of the restoration member  11  to escape towards outside of the left side wall section  20 L via the guide opening  36 . The resilient piece controlling section  35  is designed and constructed so that the force of elasticity stored in the restoration member  11  acts as a driving force to produce the restoration operation for the lancet unit  2  following the pricking operation. 
         [0075]    At the corners of the outer peripheral wall sections of the main housing member  20 , there are formed fitting holes  38 . In these fitting holes  38 , fitting pins  39  provided on the upper plate  21  are engaged to unify the main housing member  20  and the upper plate  21  together. Of course, the fitting holes  38  do not have to be formed at the respective corners. For example, these fitting holes may be formed on the upper surface wall section  20 B in clipping the guide hole  34  as large-sized holes. Or, the fitting holes may be formed at optional sites of the resilient piece controlling section  35  on which the force of elasticity of the restoration member  11  directly acts. 
         [0076]    With the above mentioned configuration of the main housing member  20 , the hinge  21 A is bent, as the lancet unit  2  is housed within the lancet accommodating void portion  23 , whereby the upper plate  21  closes the lancet accommodating void portion  23  to unify the housing unit and the lancet unit to each other. This state is referred to below as a unified state. As shown in  FIGS. 1 and 4 , the upper plate  21  is of the overall planar shape equivalent to the outer shape of the main housing member  20 . The upper plate  21  includes the guide cam groove  26 A in the height-wise direction corresponding to the guide cam groove  26 B of the main housing member  20 , while also including the first lock cam sections  28 AL,  28 AR corresponding to the second lock cam sections  28 BL,  28 BL. 
         [0077]    In the unified state, the upper plate  21  causes the guide rib  12 A of the lancet unit  2  to be engaged in the guide cam groove  26 A. In the unified state, the cam bumps  16 L 1 ,  16 R 1  on the lancet unit  2  are engaged with the lock cam sections  28 AL,  28 AR of the upper plate  21 . 
         [0078]    At the respective corners on the inner side of the upper plate  21 , there are formed the fitting pins  39  facing to the fitting holes  38  formed in the main housing member  20 . When the upper plate  21  is turned over the main housing member  20  by bending at the hinge  21 A, the fitting pins  39  are press-fitted in the mating fitting holes  38 , whereby the upper plate  21  may be unified with the main housing member  20 . The fitting holes  38  and the fitting pins  39  may all be of the same shape, or may differ in shape from one fitting position to the next, as shown in  FIG. 4 . 
         [0079]    The fitting pins  39  may be in the form of round bars or cylinders if so desired. 
         [0080]    With the pricking device  1 , the above mentioned lancet unit  2  and the housing unit  3  are molded using respective metal molds designed to fabricate one-piece molded products. The so fabricated lancet unit  2  and housing unit  3  are delivered to, for example, an automatic assembling process to complete the pricking device  1 . The metal molds used for shaping the lancet unit  2  or the housing unit  3  are slightly more complex in structure than the conventional metal molds. It is however possible to mold the lancet unit  2  or the housing unit  3  of higher precision more efficiently. 
         [0081]    The lancet unit  2  and the housing unit  3  of the pricking device  1  are substantially plate-shaped members, and hence may not be bulky in size or may not be entangled, thus providing for facilitated handling during the molding and assembling processes. In addition, the lancet unit  2  or the housing unit  3  may be placed side-by-side on an automatic transfer machine. It is thus possible to manufacture the pricking device  1  at a drastically reduced cost. 
         [0082]    During an assembling process for the pricking device  1 , the housing unit  3 , supplied from the transfer machine into an assembling cavity of an automatic assembling system, is set with the lancet accommodating void portion  23  of  FIG. 4  directed upwards. The lancet unit  2  supplied from another transfer machine is assembled to this housing unit  3 . The assembling process may be carried out by dropping the lancet unit  2  into the lancet accommodating void portion  23  to assemble the lancet unit  2  to the main housing member  20  of the housing unit  3 . 
         [0083]    In the assembling process, the upper plate  21  is placed over the main housing member  20 , into which the lancet unit  2  has been dropped. In the assembling process, the upper plate  21  placed on the main housing member  20  is thrust to fit the fitting pin  39  into the fitting hole  38  to assemble the housing unit  3 . This completes the pricking device  1 , with the actuation plate  6  projecting upwards and with the lancet cover member  14  projecting downwards, as shown in  FIG. 2 . 
         [0084]    The pricking device  1  is small in size, in comparison with the above mentioned conventional pricking device. In addition, it is of a simplified shape like a box of thin thickness, as shown in  FIG. 2 . The pricking device  1  may readily be packed, while space saving may be achieved in storage or transportation. 
         [0085]    &lt;Method for Use&gt; 
         [0086]    With the above mentioned pricking device  1 , the lancet cover member  14  protruded from the housing unit  3  is broken at the time of the pricking operation. A user holds the housing unit  3  of the pricking device  1  with one hand, and holds and twists the grip  19  of the lancet cover member  14  with the other hand. This breaks the base end of the shaft-shaped cover  18  from the unit body member  5  so that the lancet cover member  14  may be taken out from the housing unit  3 . 
         [0087]    With the pricking device  1 , the foremost part of the needle  4 , insert-molded in the bulk of the shaft-shaped cover  18  of the lancet cover member  14 , is now exposed. With the pricking device  1 , the foremost part of the needle  4  thus exposed is accommodated within the housing unit  3 , and hence there is no risk that the finger&#39;s tip, for example, of the user or the test subject is inadvertently injured. 
         [0088]    With the pricking device  1 , the user holds the mid sites of the front and reverse major surfaces of the housing unit  3  with his/her thumb and middle finger, and thrusts its bottom, as the lancet pop-out opening  29  is aligned with the pricking site, such as the finger&#39;s tip. With the pricking device  1 , the user thrusts the actuation plate  6  protruded on top of the upper plate  21  with his/her trigger finger, whereby the foremost part of the needle  4  pops out via the lancet pop-out opening  29  to prick the finger&#39;s tip, for example. Since the lower surface wall section  20 C of the main housing member is arched, it fits to a curved surface, such as that of the finger&#39;s tip, thus preventing offsetting of the pricking position. 
         [0089]    The needle  4  may be housed within the housing unit  3  by the user moves the pricking device  1  away from the pricking site and releasing his/her finger&#39;s tip, so far thrusting the actuation plate  6 . With the pricking device  1 , the lancet unit  2 , resiliently held in place within the lancet accommodating void portion  23 , is locked by the resilient piece for lock  13 . The pricking device  1  is discarded as the needle  4  is housed within the housing unit  3 . 
         [0090]    &lt;Pricking Operation&gt; 
         [0091]    The movement of the lancet unit  2  within the housing unit  3  accompanying the above mentioned pricking operation is now described with reference to  FIGS. 5 to 8 . When the lancet cover unit  14  is broken off, the needle  4  may have its foremost part exposed from the unit body member  5 , as shown in  FIG. 5 . However, the needle  4  is housed within the housing unit  3 . With the pricking device  1 , the controlling resilient piece  22  of the lancet unit  2  is situated in a space between the controlling convexed wall section  24  and the upper surface wall section  20 B of the main housing member  20 . This prescribes the initial position of the pricking device  1 . 
         [0092]    In the initial position of the lancet unit  2  of the pricking device  1 , the foremost part of the restoration member  11  is abutted against the guide wall section  25  of the resilient piece controlling section  35  formed in the main housing member  20 . Moreover, in the initial position of the lancet unit  2  of the pricking device  1 , the cam bump  16 , formed at the foremost part of the resilient piece for lock  13 , is engaged with a foremost part of the cam groove  32  of the lock cam section  28  formed at each of the upper plate  21  and the main housing member  20  of the housing unit  3 . From this initial position of the pricking device  1 , the actuation plate  6  is thrust, as indicated by arrow A in  FIG. 5 . 
         [0093]    With the pricking device  1 , the unit body member  5  formed as one with the actuation plate  6  is moved downwards within the housing unit  3 . With the pricking device  1 , the guide ribs  12 , formed on the front and reverse surfaces of the unit body member  5 , are moved within the guide cam grooves  26  formed in the main housing member  20  and in the upper plate  21 , as the guide ribs are kept engaged with the guide cam grooves  26 . The lancet unit  2  may thus be moved downwards in a stabilized position. 
         [0094]    As the actuation plate  6  is thrust and the lancet unit  2  is moved downwards, the restoration member  11  is guided along the guide wall section  25 , with the foremost part of the restoration member  11  sliding on the smoothed receiving surface. The foremost part of the restoration member  11  is protruded outwards from the guide opening  36 , as shown by arrows B in  FIGS. 5 and 6 . The force of elasticity is thus gradually stored in the restoration member  11 . As the lancet unit  2  of the pricking device  1  is moved further, the cam bump  16  is moved downwards within the cam groove  32 , as indicated by arrows C in  FIGS. 5 and 6 . The resilient piece for lock  13  is gradually elastically displaced within the free void area  15  towards the center of the unit body member  5  to store the force of elasticity therein. As the lancet unit  2  is moved further downwards, the restoration member  11  is bent significantly. On the other hand, the controlling resilient piece  22  of the unit body member controlling section  10  abuts on the controlling convexed wall section  24  and is thereby displaced elastically. 
         [0095]    When the unit body member  5  is moved by more than a preset amount, the controlling resilient piece  22  is set free from the controlling convexed wall section  24 . Hence, the unit body member  5  is moved vigorously within the housing unit  3 , so that the needle  4  is able to pop out from the state shown in  FIG. 6  to the state shown in  FIG. 7 . 
         [0096]    The pricking device  1  is halted with the unit body member  5  abutting against the inner surface of the lower surface wall section  20 C of the main housing member  20 , as shown in  FIG. 7 . At this time, the foremost part of the needle  4  is protruded a preset length out of the lancet pop-out opening  29 . As the lancet unit  2  is moved, the cam bump  16  formed on the resilient piece for lock  13  is moved from the lower end of the cam groove  32  to the cam opening  30  to release a part of the force of elasticity stored in the resilient piece for lock  13 . With the resilient piece for lock  13  thus decompressed, the cam bump  16  is moved laterally within the cam opening  30 , as indicated by arrow D in  FIG. 7 . 
         [0097]    In an initial stage of thrusting of the actuation plate  6 , the lancet unit  2  of the pricking device  1  is restricted its movement. When a preset thrust position is surpassed, the lancet unit  2  performs a movement of descent instantaneously. Hence, the pricking device  1  allows for a stabilized needle pop-out operation. In addition, with the pricking device  1 , there is no risk that the lancet unit is vibrated vertically due to variations in the force of elasticity of the elastic member, thus possibly causing pricking a second time or even a third time, as is often the case with the conventional pricking devices. 
         [0098]    With the pricking device  1 , when the user has released his/her trigger finger that has so far thrust the actuation plate  6 , there occurs the movement of restoration of the lancet unit  2  as shown in  FIG. 8 . The unit body member  5  of the pricking device  1  is at a lower position within the housing member  20 , and the restoration member  11  is hoisted by the guide wall section  25  of the resilient piece controlling section  35 , as shown in  FIG. 7 . Hence, the force of elasticity is stored in the restoration member  11 . As the lancet unit  2  performs its movement of restoration upwards under the force of elasticity stored in the restoration member  11 , the needle  4  is retracted via the lancet pop-out opening  29  into the inside of the housing unit  3  of the pricking device  1 . 
         [0099]    The lancet unit  2  of the pricking device  1  performs a movement of restoration in a stabilized position as the guide rib  12  is engaged within the guide cam groove  26  and moved in this condition. With the movement of restoration of the lancet unit  2 , the foremost part of the restoration member  11  is entrained into the inside of the housing unit  3 . With the movement of restoration of the lancet unit  2 , the resilient piece for lock  13  is also returned as the cam bump  16  formed at its distal end is kept in abutment with the side edge of the cam opening  30  that forms the lock cam section  28  provided on the housing unit  3 . 
         [0100]    When the lancet unit  2  has been returned to a preset position, the cam bump  16  is engaged in the cam recess  31  of the lock cam section  28 . At this time, the cam bump  16  of the resilient piece for lock  13  is engaged in the cam recess  31  formed in the housing unit  3 . The cam bump  16  is kept engaged in the cam recess  31  under the force of elasticity stored in the resilient piece for lock  13 . 
         [0101]    With the pricking device  1 , the position of restoration of the lancet unit  2  is prescribed by a state in which the actuation plate  6  has been slightly thrust downwards from the initial position, as shown in  FIGS. 5 and 8 . In this state, the foremost part of the restoration member  11  is slightly protruded from the resilient piece controlling section  35 , with the needle  4  being housed within the housing unit  3 . 
         [0102]    In this state, the cam bump  16  of the resilient piece for lock  13  is engaged with the foremost part of the cam recess  31  formed in the housing unit  3 , and is retained at the foremost part under the force of elasticity stored in the resilient piece for lock  13 . Thus, even if the actuation plate  6  is re-thrust, the needle  4  is inhibited from popping out a second time, thus assuring a high degree of safety. With the pricking device  1 , even if the actuation plate  6  is inadvertently re-thrust, the cam bump  16  of the resilient piece for lock  13  is retained by the foremost part of the cam recess  31  of the housing unit  3  under the force of elasticity of the resilient piece for lock  13 . 
         [0103]    In the pricking device  1  shown above as an embodiment, respective component parts of the lancet unit  2  or the housing unit  3 , formed of synthetic resin materials, may be changed as desired. The unit body member  5  that forms the lancet unit  2 , the restoration member  11  or the resilient piece for lock  13  may be of any suitable shape other than that described above. With the pricking device  1 , the main housing member  20  and the upper plate  21  are unified together by press-fitting a plurality of the fitting pins  39  into a plurality of the fitting holes  38 . If desired to further improve the mechanical strength of the unified portions, ultra-sonic welding, for example, may be applied to the unified portions. 
         [0104]    The pricking device  1  includes an automatic lock mechanism in which the resilient piece for lock  13  provided with the cam bumps  16  is formed on the lancet unit  2 , while also including a lock cam section  28  on the housing unit  3 . The lock cam section  28  includes the cam opening  30 , cam recess  31 , cam groove  32  and the guide cam tongue  33 . The automatic lock mechanism allows for automatic locking of the lancet unit  2 . 
         [0105]    With the pricking device described above, the lancet unit  2  and the housing unit  3  may be reduced in thickness, such that it is possible to achieve a global thickness on the order of 4.6 mm. With the pricking device  1 , the metal molds used for fabricating the lancet unit  2  and the cam housing  3  by molding may be simplified in structure, thus further reducing the production costs. 
       Second Embodiment 
       [0106]    A pricking device  50 , shown in  FIG. 9  as a second embodiment, has a basic structure in common with the above described pricking device  1 . However, with the second embodiment, the structures of the lancet unit  2  and the housing unit  3  are simplified to reduce the size and production costs. Hence, the same reference numerals are used to depict corresponding parts and the description thereof is dispensed with. Stated briefly, with the second embodiment, the resilient piece controlling sections and the automatic lock mechanism for the lancet unit are provided only on one side of the pricking device, that is, on its left or right side, thereby simplifying the structure. 
         [0107]    With the pricking device  50 , the guide ribs  12  are formed as one with front and reverse side major surfaces of the unit body member  5  of the lancet unit  2 , and are engaged in the guide cam groove  26  formed in the main housing unit  20  and in the upper plate  21  for movement in the lancet accommodating void portion  23 . The lancet unit  2  is molded integrally of the above mentioned synthetic resin material, while the housing unit  3  is also molded integrally of the above mentioned synthetic resin material, so that component parts of the pricking device  50  may be formed to preset dimensional accuracy and preset mechanical strength. With the pricking device  50 , the lancet unit  2  may be moved in stability within the housing unit  3  during the pricking operation. With the pricking device  50 , the lancet unit  2 , returned into the inside of the housing unit  3 , may be kept retained by the lancet unit automatic lock mechanism to inhibit the re-use of the lancet unit. 
       Third Embodiment 
       [0108]    A pricking device  60 , shown as a third embodiment in  FIGS. 10 and 11 , has its basic structure in common with the above mentioned pricking device  1 . However, with the present embodiment, a restoration member  11  is provided on the housing unit  3 , instead of on the lancet unit  2 . Since the pricking device  60  has a basic structure in common with the above mentioned pricking device  1 , corresponding parts are denoted by the same reference numerals, and detailed description thereof is here dispensed with. 
         [0109]    With the pricking device  60 , a lancet unit  61  is used in place of the lancet unit  2 , as shown in  FIG. 10 . This lancet unit  61  is housed within a main housing unit  20 . The restoration member  11  provided at the mid part  5 B of the unit body member  5  with the above mentioned embodiments is not provided on the lancet unit  61  of the pricking device  60 , so that the mid part  5 B is simplified in structure. With the pricking device  60 , restoration members  62 L,  62 R are provided on the main housing unit  20  at corresponding positions. That is, the proximal ends of the restoration members  62 L,  62 R are formed as one with mid portions of left and right side wall sections  20 L,  20 R of the main housing unit  20 , while the foremost parts thereof abut against the lower end of the upper part  5 A. The restoration members  62 L,  62 R may be moved as indicated by arrow E in  FIG. 10 , so that there is stored a force of elasticity therein with downward movement of the lancet unit  61 . 
         [0110]    Since the pricking device  60  is provided with the restoration members  62 L,  62 R, a bottom plate  20 A of the main housing member  20  is formed with openings  63 L,  63 R, as shown in  FIG. 11 . These openings are used in forming the proximal ends of the restoration members as one with the left and right side wall sections  20 L,  20 R at the time of molding the main housing member  20 . 
         [0111]    The pricking device  60  having the above mentioned structure operates similarly to the pricking device  1 . That is, a lancet unit  61 , returned into the inside of the housing unit  3 , is kept retained due to the lancet unit automatic lock mechanism to inhibit re-use of the lancet unit. 
         [0112]    It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present subject matter and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.