Abstract:
An injection device tip includes a body configured to be removably connected to an injection device and a needle having a portion projecting from a proximal end of the body. The body at least one of has flexible portions which can be deflected inwardly to cause release of an engagement between the body and a proximal end of the injection device, has two oppositely arranged flexible portions arranged outside an imaginary circle defined by an outside surface of two opposite portions arranged between the two oppositely arranged flexible portions, is generally oval in shape, is generally rectangular in shape, is generally square in shape, and is non-circular in shape. This Abstract is not intended to define the invention disclosed in the specification, nor intended to limit the scope of the invention in any way.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The instant application is a US non-provisional Application based on U.S. provisional application No. 61/178,673, filed May 15, 2009, the disclosure of which is hereby expressly incorporated by reference hereto in its entirety. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to pen injection devices, e.g., pre-loaded syringes, such as are utilized for injection of medicament into the body tissues of human and animal patients. More specifically, this invention relates to a removable pen needle which is more easily removed from the pen injection device. The pen needle can preferably include a safety system or shield to prevent inadvertent pricking on a user. 
     This invention also relates to a method of using pen needles for pen injection devices wherein the pen needle is configured to be used with conventional the pen injection device. 
     This invention also relates to a method of using pen injection devices more safely, i.e., preventing the user from being pricked when handling and/or attempting to remove the pen needle from the pen injection device. 
     2. Discussion of Background Information 
     U.S. Pat. No. 4,973,318, the disclosure of which is hereby expressly incorporated by reference in its entirety, discloses a disposable syringe includes first and second housing elements which are coupled together for rotation without axial movement therebetween. The first housing element receives a cartridge of a solution to be injected, and mounts a liquid outlet needle at its front end. A piston rod is disposed in the second housing element to move axially therein, and this piston rod includes a rod element and a nut element. The rod element is coupled to the first housing element to move axially therein without relative rotation therewith, and the nut element is threaded to the rod element for telescoping movement therewith and is configured to move axially in the second housing element without relative rotation therein. A pressure receiving element is mounted on the nut element. The housing, rod, nut and pressure receiving elements cooperate such that relative rotation between the housing elements in a selected direction causes relative rotation between the nut and rod elements and thereby increases the effective length of the piston rod and causes the pressure receiving element to extend from the second housing element. A protective cap is removably mounted over the first housing element and is configured to abut second housing element while mounted in place on the first housing element. This protective cap is engaged with the first housing element such that rotation of the cap with respect to the second housing element causes rotation of the first housing element with respect to the second housing element. 
     This type of syringe is shown in  FIGS. 1 and 2  wherein the pre-loaded syringe  1  has a proximal threaded end  2  which is configured to accept a needle tip assembly consisting of a needle tip  5 , a needle tip cover, and a needle cover. A user installs the needle tip assembly  5  onto the end  2 , after removing the assembly from its individual package, onto the threaded proximal end  2  by simply sliding it onto the end  2  axially. Because internal threads of the needle tip  5  are mounted to radially deflectable members, installation over threads of the end  2  occurs with a ratchet effect. This installation is made safe by the covers which ensure that the user will not be pricked by the needle N. Once installed, the user can remove the needle tip cover by simply sliding it off axially. Next, the user can remove the needle cover to expose the needle N. The pen needle device is then made ready for use in providing an injection to the user. After injection, the user will typically remove the needle tip  5  and discard the same. To accomplish the removal, the user will typically reinstall the needle tip cover and rotate it to cause the needle tip to unthread from the threaded end  2  (some users may even install the needle cover prior to installing the cover). Once removed, however, it is still possible to reinstall the used needle tip  5  by simply repeating the steps noted above. Unless the user discards the needle tip  5 , it is possible that she or other users will not remember or know that it has already been used. That is, there is nothing to prevent reuse of the needle tip  5  should someone attempt to reinstall the needle tip onto the end  2 . Furthermore, if the user is unable to locate the covers (i.e., if they have become lost), he/she must then attempt to grip the needle tip  5  in order to unthread it from the end  2 . As is apparent, this action can be risky because the user can possibly inadvertently be pricked by the needle N either in attempting to properly grip the needle tip  5 , in the action of rotating it to the point it is removed, or even in the handling of the needle tip  5  after it has been removed and prior to being properly discarded. Still further, if the needle tip  5  is not properly discarded (such as being correctly placed in a sharps container), others may come in contact with the needle tip  5  and possibly become injured thereby. 
     It is therefore desirable to provide a pen needle system which is safer to use compared to the conventional devices discussed above and/or which does not have one or more of the above-noted disadvantageous. 
     SUMMARY OF THE INVENTION 
     According to one non-limiting embodiment of the invention, there is provided an injection device tip comprising a body configured to be removably connected to an injection device and a needle having a portion projecting from a proximal end of the body. The body at least one of has flexible portions which can be deflected inwardly to cause release of an engagement between the body and a proximal end of the injection device, has two oppositely arranged flexible portions arranged outside an imaginary circle defined by an outside surface of two opposite portions arranged between the two oppositely arranged flexible portions, is generally oval in shape, is generally rectangular in shape, is generally square in shape, and is non-circular in shape. 
     The needle may be a double-ended having one end projection from the proximal end of the body. The body may comprise at least one projection for engaging an external thread of the proximal end of the injection device. Once installed, the tip may threadably engage with the proximal end of the injection device. The body may comprise at least one partial internal thread section for engaging an external thread of the proximal end of the injection device. The body may comprise at least two oppositely arranged partial internal thread sections for engaging an external thread of the proximal end of the injection device. The body may include the flexible portions which can be deflected inwardly to cause release of an engagement between the body and a proximal end of the injection device and is generally oval in shape. The body may include the flexible portions which can be deflected inwardly to cause release of an engagement between the body and a proximal end of the injection device and is generally non-circular in shape. The body may include the flexible portions which can be deflected inwardly to cause release of an engagement between the body and a proximal end of the injection device and is generally non-circular in shape. The body may include the two oppositely arranged flexible portions arranged outside an imaginary circle defined by an outside surface of two opposite portions arranged between the two oppositely arranged flexible portions and is generally oval in shape. The body may include the two oppositely arranged flexible portions arranged outside an imaginary circle defined by an outside surface of two opposite portions arranged between the two oppositely arranged flexible portions and is generally non-circular in shape. 
     The tip may further comprise a safety shield adapted to cover the needle. The tip may further comprise a safety shield movably mounted to the body and being adapted to cover the needle. The tip may further comprise a safety shield movably mounted to the proximal end of the body. 
     The tip may further comprise a safety shield arranged on the proximal end of the body. The safety shield may be movable at least between an initial position and an extended position. The initial position and the extended position may each cover a free end of the needle. The safety shield may be movable at least between an initial position, a retracted position, and an extended position. The initial position may cover a free end of the needle and the retracted position may expose a free end of the needle. The extended position may cover a free end of the needle and the retracted position may expose a free end of the needle. The initial position may cover a free end of the needle, the retracted position may expose a free end of the needle, and the extended position may prevent re-use of the tip. The retracted position may expose a free end of the needle and, in the extended position, the safety shield may be one of locked and non-movably retained. 
     The invention also provides for a method of removing the tip of the type described above, wherein the method comprises installing the tip onto a proximal end of an injection device and removing the tip by applying a squeezing force to opposite sides of the body. 
     The invention also provides for a pre-filled injection device comprising at least one feature of the tip shown in at least one drawing of the instant application. 
     The invention also provides for a pre-filled injection device comprising a pre-filled injection device body and a removable pen needle installed on the pre-filled injection device body. The pen needle at least one of has flexible portions which can be deflected inwardly to cause release of an engagement between the body and a proximal end of the injection device, has two oppositely arranged flexible portions arranged outside an imaginary circle defined by an outside surface of two opposite portions arranged between the two oppositely arranged flexible portions, is generally oval in shape, is generally rectangular in shape, is generally square in shape, and is non-circular in shape. 
     The invention also provides for a pen needle comprising a body configured to be removably connected to an injection device, a needle having a portion projecting from a proximal end of the body, and the body comprising deflectable or flexible portions which can be deflected inwardly to cause release of an engagement between the body and a proximal end of the injection device. The deflectable or flexible portions are arranged outside an imaginary circle defined by an outside surface of at least one other portion of the body. 
     Other exemplary embodiments and advantages of the present invention may be ascertained by reviewing the present disclosure and the accompanying drawing. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention is further described in the detailed description which follows, in reference to the noted plurality of drawings by way of non-limiting examples of exemplary embodiments of the present invention, in which like reference numerals represent similar parts throughout the several views of the drawings, and wherein: 
         FIG. 1  shows an enlarged partial side view of a proximal end of a prior art pen needle device or pre-loaded syringe/injection device. The proximal end is shown with the cap removed and in a prior-use state, i.e., it is ready to receive thereon a needle tip or pen needle; 
         FIG. 2  shows a prior art needle tip assembly (in cross-section with the exception of the needle) in a position prior to installation onto the proximal end; 
         FIG. 3  shows a rear end view of a first non-limiting embodiment of a pen needle or tip assembly according to the invention; 
         FIG. 4  shows a side cross-section view of the pen needle or tip assembly shown in  FIG. 3 . The hollow needle is not shown in cross-section; 
         FIGS. 5 and 6  show rear end views of the pen needle or tip assembly of  FIGS. 3 and 4  in an initial position ( FIG. 5 ) and a compressed position ( FIG. 6 ). The up and down facing arrows in  FIG. 6  show how a squeezing force applied to deflectable sections of the body causes the sections of the body having the partial thread sections to move outwardly (as illustrated by the horizontal facing arrows); 
         FIG. 7  shows a rear end view of a second non-limiting embodiment of a pen needle or tip assembly according to the invention; 
         FIG. 8  shows a side cross-section view of the pen needle or tip assembly shown in  FIG. 7 . The hollow needle is not shown in cross-section; 
         FIGS. 9 and 10  show side cross-section views of the pen needle or tip assembly of  FIGS. 7 and 8  with the safety-shield being in an initial or extended position ( FIG. 9 ) and a using or retracted position ( FIG. 10 ). This embodiment is similar to the first embodiment but additionally includes a safety-shield and spring; 
         FIG. 11  shows a side cross-section view of the pen needle or tip assembly of  FIGS. 7 and 8  installed on a prior art pen needle device or pre-loaded syringe/injection device. The safety-shield is in the initial or extended position; 
         FIG. 12  shows another side cross-section view of  FIG. 11  except that the safety-shield is in the retracted position; 
         FIG. 13  shows a rear end view of the pen needle or tip assembly of  FIGS. 7 and 8  with the safety-shield removed; 
         FIG. 14  shows a side cross-section view of the pen needle or tip assembly shown in  FIG. 13 . The hollow needle is not shown in cross-section; 
         FIG. 15  shows a side view of the safety-shield that is used on the pen needle or tip assembly shown in  FIGS. 7 and 8 ; 
         FIG. 16  shows a rear end view of the safety-shield shown in  FIG. 15 ; 
         FIG. 17  shows a front end view of the safety-shield shown in  FIG. 15 ; 
         FIG. 18  shows a side cross-section view of another non-limiting embodiment of a pen needle or tip assembly according to the invention. The hollow needle is not shown in cross-section. The safety-shield is shown in an initial or nearly-fully extended position. This embodiment is similar to the second embodiment but additionally includes a system for locking the safety-shield in fully extended position and/or rendered the pen needle single-use; 
         FIG. 19  shows a side cross-section view of the pen needle or tip assembly of  FIG. 18  with the safety-shield being in a fully extended and locked position. In this position, the pen needle or tip assembly is rendered unreusable; 
         FIG. 20  shows a rear end view of the pen needle or tip assembly of  FIG. 18 ; 
         FIG. 21  shows a rear end view of the pen needle or tip assembly of  FIG. 20  with the safety-shield removed; 
         FIG. 22  shows a side cross-section view of another non-limiting embodiment of a pen needle or tip assembly according to the invention. The hollow needle is not shown in cross-section. The safety-shield is shown in an initial or nearly-fully extended position. This embodiment is similar to the second embodiment but additionally includes a system for locking the safety-shield in fully extended position and/or rendered the pen needle single-use; 
         FIG. 23  shows a side cross-section view of the pen needle or tip assembly of  FIG. 22  with the safety-shield being in a fully extended and locked position. In this position, the pen needle or tip assembly is rendered unreusable; 
         FIG. 24  shows a side cross-section view of another non-limiting embodiment of a pen needle or tip assembly according to the invention. The hollow needle is not shown in cross-section. The safety-shield is shown in an initial or nearly-fully extended position. This embodiment is similar to the second embodiment but additionally includes a system for locking the safety-shield in fully extended position and/or rendered the pen needle single-use; 
         FIG. 25  shows a side view of the pen needle or tip assembly of  FIG. 24 ; 
         FIG. 26  shows a side cross-section view of another non-limiting embodiment of a pen needle or tip assembly according to the invention. The hollow needle is not shown in cross-section. The safety-shield is shown in an initial or nearly-fully extended position. This embodiment is similar to the second embodiment but additionally includes a system for locking the safety-shield in fully extended position and/or rendered the pen needle single-use; 
         FIG. 27  shows a side view of the pen needle or tip assembly of  FIG. 26 ; 
         FIG. 28  shows a side cross-section view of another non-limiting embodiment of a pen needle or tip assembly according to the invention. The hollow needle is not shown in cross-section. The safety-shield is shown in an initial or fully extended position; 
         FIG. 29  shows a side cross-section view of the pen needle or tip assembly of  FIG. 28 . The safety-shield is shown in a using/injection or fully retracted position; 
         FIG. 30  shows a side cross-section view of another non-limiting embodiment of a pen needle or tip assembly according to the invention. The hollow needle is not shown in cross-section. The safety-shield is shown in an initial or fully extended position; 
         FIGS. 31 and 32  show side cross-section and rear views of another non-limiting embodiment of a pen needle or tip assembly according to the invention. Like other embodiments, the embodiment utilizes a system for locking the safety-shield in a fully extended position so as to prevent re-use of the pen needle. This embodiment also illustrates how the pen needle can be individually packaged. The packaging includes a removable seal having a pull-tap and a removable front outer cover; 
         FIGS. 33 and 34  show side cross-section and rear views of another non-limiting embodiment of a pen needle or tip assembly according to the invention. Like other embodiments, the embodiment utilizes a system for locking the safety-shield in a fully extended position so as to prevent re-use of the pen needle. This embodiment also illustrates how the pen needle can be individually packaged. The packaging includes a removable seal having a pull-tap and a removable front outer cover that extends to the seal—thereby completely enclosing the pen needle; 
         FIG. 35  shows a side cross-section view of the pen needle used in the embodiments of  FIGS. 31-34  with the packaging removed. The hollow needle is not shown in cross-section. The safety-shield is shown in an initial or nearly-fully extended position; 
         FIG. 36  shows a side cross-section view of the pen needle or tip assembly of  FIG. 35  with the safety-shield being in a fully extended and locked position. In this position, the pen needle or tip assembly is rendered unreusable; 
         FIG. 37  shows a side view of the pen needle or tip assembly of  FIGS. 35 and 36  with the safety-shield removed and rotated 90 degrees; 
         FIG. 38  shows a side view of the safety-shield used in the assembly of  FIGS. 35 and 36  and rotated 90 degrees; 
         FIG. 39  shows a side cross-section view of the front cover used in the embodiment shown in  FIG. 33 ; 
         FIG. 40  shows a rear view of the front cover shown in  FIG. 39 ; 
         FIG. 41  shows a rear end view of another non-limiting embodiment of a pen needle or tip assembly according to the invention. In this embodiment, the pen needle body is more rectangular-shaped than the oval-shape shown in  FIG. 3 ; 
         FIG. 42  shows a rear end view of another non-limiting embodiment of a pen needle or tip assembly according to the invention. In this embodiment, the pen needle body shown in  FIG. 41  is modified to utilize a needle-shield (not shown) and utilizes slots that receive therein portions of the safety-shield; 
         FIG. 43  shows a rear end view of another non-limiting embodiment of a pen needle or tip assembly according to the invention. In this embodiment, the pen needle body is even more rectangular-shaped than the shape shown in  FIG. 41 ; 
         FIG. 44  shows a rear end view of another non-limiting embodiment of a pen needle or tip assembly according to the invention. In this embodiment, the pen needle body is made similar to that shown in  FIG. 43  and is modified to utilize indented finger-receiving sections and a needle-shield (not shown) and utilizes slots that receive therein portions of the safety-shield; 
         FIG. 45  shows a side cross-section view of another non-limiting embodiment of a pen needle or tip assembly according to the invention. The hollow needle is not shown in cross-section. This embodiment also utilizes a lockable safety-shield so as to prevent re-use of the pen needle and a removable front outer cover. The safety-shield is shown in an initial or nearly-fully extended position; 
         FIG. 46  shows a side cross-section view of another non-limiting embodiment of a pen needle or tip assembly according to the invention. The hollow needle is not shown in cross-section. This embodiment also utilizes a lockable safety-shield so as to prevent re-use of the pen needle and a system for releasably retaining the safety-shield in the initial or nearly-fully extended position. This system also prevents the safety-shield from moving from the fully extended position back to the initial position. The safety-shield is shown in an initial or nearly-fully extended position; 
         FIG. 47  shows a side cross-section view of the pen needle or tip assembly of  FIG. 46 . The safety-shield is shown in a using/injection or fully retracted position; 
         FIG. 48  shows a side cross-section view of another non-limiting embodiment of a pen needle or tip assembly according to the invention. The hollow needle is not shown in cross-section. This embodiment also utilizes a lockable safety-shield so as to prevent re-use of the pen needle and a system for releasably retaining the safety-shield in the initial or nearly-fully extended position. This system also prevents the safety-shield from moving from the fully extended position back to the initial position. The safety-shield is shown in the fully extended and locked position; 
         FIG. 49  shows a rear end view of the pen needle or tip assembly of  FIG. 48  with the safety-shield removed; 
         FIG. 50  shows a rear end view of the safety-shield used in the pen needle or tip assembly of  FIG. 48 ; 
         FIGS. 51-54  show partial cross-section views of additional non-limiting embodiments of safety shields having differently textured proximal surfaces, i.e., different surface configurations for contacting a user&#39;s skin; and 
         FIGS. 55-58  show side cross-section and rear views of a non-limiting embodiment of a front cover or outer cap which can be used on any of the herein disclosed oval-shaped pen needles.  FIGS. 57 and 58  are rotated 90 degrees relative to  FIGS. 55 and 56 . The front cover can be removed and rotated 90 degrees and then reinstalled so that axial sliding on of the front cap causes the squeezing forces shown in  FIG. 6 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings and first to  FIGS. 3-6  which shows a first embodiment of a needle tip assembly. Although not shown, the needle tip assembly includes a needle tip cap (similar to cap 30 in US 2008/0154192) having various generally cylindrical portions with different diameters, a needle cap (similar to cap 40 in US 2008/0154192), and a pen needle or tip assembly  10 . The proximal end of the pen needle  10  includes a needle N while the distal end  15  includes an opening which is sized to allow the pen needle  10  to be mounted to the threaded proximal end  2  of the pen needle injection device  1 . The tip  10  includes a main support  11 , a proximal surface, wall or end  12 , an inner space  16 , and two oppositely arranged thread sections  14 . The body  13  has an generally oval shape, is made of an elastic material such as synthetic resin, and includes two oppositely arranged inwardly deformable/deflectable sections  13   a  and with two oppositely arranged outwardly deformable/deflectable sections  13   b . Each thread section  14  is arranged on an internal surface of one of the two oppositely arranged outwardly deformable/deflectable sections  13   b.    
     In accordance with one embodiment, in order to ensure that the pen needle  10  can be installed, removed and/or re-installed after use onto the proximal end  2 , the pen needle  10  utilizes an oval body  13  which can be deformed from an initial or relaxed position (see  FIG. 3 ) which allows the tip  10  to be threaded onto the section  2  and to a fully deformed position (see  FIG. 6 ) which causes the thread sections  14  to expand radially and disengage from the threads of section  2 , i.e., to deflect outwards by an amount which is sufficient to allow the tip  10  to be removed from (or installed onto) the proximal end  2 . 
     In accordance with another optional embodiment, in order to ensure that the pen needle  10  is prevented from being re-installed after use onto the proximal end  2 , the pen needle  10  utilizes an oval body  13  which can be deformed from an initial or relaxed position (see  FIG. 3 ) to a slightly deformed position (not shown) which allows the tip  10  to be threaded onto the section  2 , and to a fully deformed position (see  FIG. 6 ) which causes the thread sections  14  to expand radially and disengage from the threads of section  2 , i.e., to deflect outwards by an amount which is sufficient to allow the tip  10  to be removed from (or installed onto) the proximal end  2 . 
     As can be seen in  FIGS. 5 and 6 , prior the needle tip assembly being installed onto the threaded proximal end  2 , the user can grip the tip  10  (i.e., sections  13   a  of the tip  10 ) shown in  FIG. 5  with his/her forefinger and thumb. Then, as shown in  FIG. 6 , he/she can squeeze sections  13   a  towards each other (indicated by vertical arrows) thereby causing outward radial deflection of sections  13   b  (indicated by horizontal arrows). In the position shown in  FIG. 6 , the user can then install the tip  10  onto the section  2  by axially moving it towards and over the section  2  until it assumes the installed position (see e.g., FIG. 6 of US 2008/0154192 or  FIG. 11  of the instant application). Once the user releases the squeezing force indicated by vertical arrows in  FIG. 6 , the tip  10  will again substantially assume the shape shown in  FIG. 5  owing to the elastic nature of the body  13 . 
     Also with reference to  FIGS. 5 and 6 , if the needle tip assembly is already installed onto the threaded proximal end  2  (not shown in  FIGS. 5 and 6 ), the user can grip the tip  10  (i.e., sections  13   a  of the tip  10 ) shown in  FIG. 5  with his/her forefinger and thumb. Then, as shown in  FIG. 6 , he/she can squeeze sections  13   a  towards each other (indicated by vertical arrows) thereby causing outward radial deflection of sections  13   b  (indicated by horizontal arrows). In the position shown in  FIG. 6 , the user can then remove the tip  10  from the section  2  by axially moving it away from the section  2  and assumes the uninstalled position. 
     Also with reference to  FIGS. 5 and 6 , prior the needle tip assembly being installed onto the threaded proximal end  2 , the user can grip the tip  10  (i.e., sections  13   a  of the tip  10 ) shown in  FIG. 5  with his/her forefinger and thumb. Then, as shown in  FIG. 6 , he/she can squeeze sections  13   a  towards each other (indicated by vertical arrows) thereby causing outward radial deflection of sections  13   b  (indicated by horizontal arrows). In the position shown in  FIG. 6 , the user can then install the tip  10  onto the section  2  by axially moving it towards and over the section  2  until it assumes the installed position (see e.g., FIG. 6 of US 2008/0154192 or  FIG. 11  of the instant application). After use in injection, the user can then remove the tip  10  by unthreading it from the section  2 . This would occur by the user rotating the tip  10  until the sections  14  are fully unthreaded from the threads of the section  2 . 
     Also with reference to  FIGS. 5 and 6 , prior the needle tip assembly being installed onto the threaded proximal end  2 , the user can thread on the tip  10  (while in the relaxed position shown in  FIG. 5 ) by rotating it onto section  2  until it is fully installed thereon. Then, as shown in  FIG. 6 , he/she can squeeze sections  13   a  towards each other (indicated by vertical arrows) thereby causing outward radial deflection of sections  13   b  (indicated by horizontal arrows). In the position shown in  FIG. 6 , the user can then remove the tip  10  from the section  2  by axially moving it away from the section  2  and then allow it to assume the relaxed position of  FIG. 5 . 
     The embodiment just described as well as those described below can be used in any of the non-limiting ways described above according to the invention. 
       FIGS. 7-17  show a second non-limiting embodiment of a pen needle or tip assembly according to the invention. Corresponding features include the same reference numbers, but with an additional modifying symbol, e.g., feature  13 ′ corresponds to feature  13 .  FIG. 8  shows a side cross-section view of the pen needle or tip  10 ′ assembly which utilizes all of the features of the previous embodiment and additionally includes a safety-shield  20  and a spring S 1  for biasing the shield  20  towards an extended position (see  FIG. 9 ). The safety-shield  20  includes a generally circular front section  21  which (in the extended position) is sized and configured to extend out past the proximal end of the needle N and is configured to cover the needle N so that the user will be less likely to be pricked by the needle N. The safety-shield  20  also includes a generally circular through opening  22  which allows the needle N to pass there through when it is retracted (see  FIG. 10 ). The safety-shield  20  further also includes plural, e.g., two oppositely arranged, generally partially circular legs  23  which connect the section  21  to distal projections  24 . Each circular leg  23  is sized and configured to pass through and move within one of the partially circular slots  17 ′ formed in the body  13 ′ of the tip  10 ′. Each projection  24  is larger, i.e., thicker, than the slot  17 ′ and is sized and configured to limit and define the axial movement/position of the safety-shield  20  in the fully extended position (see  FIG. 9 ). 
       FIG. 11  shows how the pen needle or tip assembly  10 ′ can be installed onto the threaded section  2  while the safety-shield  20  is in the extended position. This allows the user to more safely install the tip  10 ′ without being pricked by the needle N which remains covered by the safety-shield  20 . The tip  10 ′ can be installed using any of the ways described above. By way of non-example, prior the needle tip assembly  10 ′ being installed onto the threaded proximal end  2 , the user can grip the tip  10 ′ (i.e., sections  13 ′ a  of the tip  10 ′) with his/her forefinger and thumb. Then, in the same way as shown in  FIG. 6 , he/she can squeeze sections  13 ′ a  towards each other (indicated by vertical arrows) thereby causing outward radial deflection of sections  13 ′ b  (indicated by horizontal arrows in  FIG. 6 ). In the squeezed position shown in  FIG. 6 , the user can then install the tip  10 ′ onto the section  2  by axially moving it towards and over the section  2  until it assumes the installed position ( FIG. 11 ). To use the device of  FIG. 11 , the user can move the device  1  so that the surface  21  contacts skin and then continue to apply sufficient force against the skin so that the safety-shield  20  retracts ( FIG. 12 ) to expose the needle N and the needle N penetrates the skin by a sufficient or desired amount. After use in injection, the user can move the device  1  away from the skin which results in the safety-shield  20  moving automatically back to the extended position ( FIG. 9 ) via the spring S 1 . After use, the user can then remove the tip  10 ′ from the device  1  by, e.g., unthreading it from the section  2 . This would occur by the user rotating the tip  10 ′ until the sections  14 ′ are fully unthreaded from the threads of the section  2 . The user can alternatively remove the tip  10 ′ from the device  1  by, e.g., squeezing sections  13 ′ a  like the way shown in  FIG. 6 , and axially sliding the tip  10 ′ away from and off of the section  2 . Once removed, the tip  10 ′ can be safely discarded as the safety-shield would reduce the likelihood of being pricked by the needle N when handling the tip  10 ′. 
       FIGS. 18-21  show another non-limiting embodiment of a pen needle or tip assembly according to the invention. Corresponding features include the same reference numbers, but with an additional modifying symbol, e.g., feature  13 ″ corresponds to feature  13 ′ or  13 .  FIG. 18  shows a side cross-section view of the pen needle or tip  10 ″ assembly which utilizes all of the features of the previous embodiment including a safety-shield  20 ′ and a spring S 1  for biasing the shield  20 ′ towards an extended position. The safety-shield  20 ′ includes a generally circular front section  21 ′ which (in the extended position) is sized and configured to extend out past the proximal end of the needle N and is configured to cover the needle N so that the user will be less likely to be pricked by the needle N. The safety-shield  20 ′ also includes a generally circular through opening  22 ′ which allows the needle N to pass there through when it is retracted. The safety-shield  20 ′ further also includes plural, e.g., two oppositely arranged, generally partially circular legs  23 ′ which connect the section  21 ′ to distal projections  24 ′. Each circular leg  23 ′ is sized and configured to pass through and move within one of the partially circular slots  17 ″ formed in the body  13 ″ of the tip  10 ″. Each projection  24 ′ is larger, i.e., thicker, than the slot  17 ″ and is sized and configured to limit and define the axial movement/position of the safety-shield  20 ′ in the fully extended and locked position (see  FIG. 19 ). As is apparent from  FIGS. 18 and 19 , when each projection  24 ′ is arranged just behind the locking sections  18 ″ formed in the body  13 ″, the safety-shield  20 ′ in an initial and/or prior-use and nearly-fully extended position (see  FIG. 18 ). However, when each projection  24 ′ is engaged (owing to the external threads  25 ′ engaging with the internal threads of sections  18 ″) with the locking sections  18 ″ formed in the body  13 ″, the safety-shield  20 ′ in a post-use of fully extended position (see  FIG. 19 ). The locking engagement between threads  25 ′ and the threads of each section  18 ″ is such that once engaged, they become locked to each other and cannot disengaged from each other without essentially destroying or damaging the tip  10 ″—thereby rendering the tip  10 ″ single-use. 
     The pen needle or tip assembly  10 ″ shown in  FIG. 18  can be installed onto the threaded section  2  while the safety-shield  20 ′ is in the nearly-fully extended position. This allows the user to more safely install the tip  10 ″ without being pricked by the needle N which remains covered by the safety-shield  20 ′. The tip  10 ″ can be installed using any of the ways described above. By way of non-example, prior the needle tip assembly  10 ″ being installed onto the threaded proximal end  2 , the user can grip the tip  10 ″ (i.e., sections  13 ″ a  of the tip  10 ″) with his/her forefinger and thumb. Then, in the same way as shown in  FIG. 6 , he/she can squeeze sections  13 ″ a  towards each other (indicated by vertical arrows) thereby causing outward radial deflection of sections  13 ″ b  (indicated by horizontal arrows in  FIG. 6 ). In the squeezed position shown in  FIG. 6 , the user can then install the tip  10 ″ onto the section  2  by axially moving it towards and over the section  2  until it assumes the installed position (not shown but similar to  FIG. 11 ). To use the device  1  with the pen needle  10 ″ installed thereon, the user can move the device  1  so that the surface  21 ′ contacts skin and then continue to apply sufficient force against the skin so that the safety-shield  20 ′ retracts to expose the needle N and the needle N penetrates the skin by a sufficient or desired amount. After use in injection, the user can move the device  1  away from the skin which results in the safety-shield  20 ′ moving automatically back to the fully extended and locked position ( FIG. 19 ) via the spring S 1 . After use, the user can then remove the tip  10 ″ from the device  1  by, e.g., unthreading it from the section  2 . This would occur by the user rotating the tip  10 ″ until the sections  14 ″ are fully unthreaded from the threads of the section  2 . The user can alternatively remove the tip  10 ″ from the device  1  by, e.g., squeezing sections  13 ″ a  like the way shown in  FIG. 6 , and axially sliding the tip  10 ″ away from and off of the section  2 . Once removed, the tip  10 ″ can be safely discarded as the safety-shield  20 ′ would reduce the likelihood of being pricked by the needle N when handling the tip  10 ″. 
       FIGS. 22 and 23  show another non-limiting embodiment of a pen needle or tip assembly according to the invention. Corresponding features include the same reference numbers, but with an additional modifying symbol, e.g., feature  13 ′″ corresponds to feature  13 ″ or  13 ′ or  13 .  FIG. 22  shows a side cross-section view of the pen needle or tip  10 ′″ assembly which utilizes all of the features of the previous embodiment including a safety-shield  20 ″ and a spring S 1  for biasing the shield  20 ″ towards an extended position. The safety-shield  20 ″ includes a generally circular front section  21 ″ which (in the extended position) is sized and configured to extend out past the proximal end of the needle N and is configured to cover the needle N so that the user will be less likely to be pricked by the needle N. The safety-shield  20 ″ also includes a generally circular through opening  22 ″ which allows the needle N to pass there through when it is retracted. The safety-shield  20 ″ further also includes plural, e.g., two oppositely arranged, generally partially circular legs  23 ″ which connect the section  21 ″ to distal projections  24 ″. Each circular leg  23 ″ is sized and configured to pass through and move within one of the partially circular slots  17 ′″ formed in the body  13 ′″ of the tip  10 ′″. Each projection  24 ″ is larger, i.e., thicker, than the slot  17 ′″ and is sized and configured to limit and define the axial movement/position of the safety-shield  20 ″ in the fully extended and locked position (see  FIG. 23 ). As is apparent from  FIGS. 22 and 23 , when each projection  24 ″ is arranged just behind the locking sections  18 ′″ formed in the body  13 ′″, the safety-shield  20 ″ in an initial and/or prior-use and nearly-fully extended position (see  FIG. 22 ). However, when each projection  24 ″ is engaged (owing to the external tapered projection  25 ″ engaging with the internal tapered locking projection of sections  18 ′″) with the locking sections  18 ′″ formed in the body  13 ′″, the safety-shield  20 ″ in a post-use of fully extended position (see  FIG. 23 ). The locking engagement between the projection  25 ″ and the projection of each sections  18 ′″ is such that once engaged ( FIG. 23 ), they become locked to each other and cannot disengaged from each other without essentially destroying or damaging the tip  10 ′″—thereby rendering the tip  10 ′″ single-use. 
     The pen needle or tip assembly  10 ′″ shown in  FIG. 22  can be installed onto the threaded section  2  while the safety-shield  20 ″ is in the nearly-fully extended position. This allows the user to more safely install the tip  10 ′″ without being pricked by the needle N which remains covered by the safety-shield  20 ″. The tip  10 ′″ can be installed using any of the ways described above. By way of non-example, prior the needle tip assembly  10 ′″ being installed onto the threaded proximal end  2 , the user can grip the tip  10 ′″ (i.e., sections  13 ′″ a  of the tip  10 ′″) with his/her forefinger and thumb. Then, in the same way as shown in  FIG. 6 , he/she can squeeze sections  13 ′″ a  towards each other (indicated by vertical arrows) thereby causing outward radial deflection of sections  13 ′″ b  (indicated by horizontal arrows in  FIG. 6 ). In the squeezed position shown in  FIG. 6 , the user can then install the tip  10 ′″ onto the section  2  by axially moving it towards and over the section  2  until it assumes the installed position (not shown but similar to  FIG. 11 ). To use the device  1  with the pen needle  10 ′″ installed thereon, the user can move the device  1  so that the surface  21 ″ contacts skin and then continue to apply sufficient force against the skin so that the safety-shield  20 ″ retracts to expose the needle N and the needle N penetrates the skin by a sufficient or desired amount. After use in injection, the user can move the device  1  away from the skin which results in the safety-shield  20 ″ moving automatically back to the fully extended and locked position ( FIG. 23 ) via the spring S 1 . After use, the user can then remove the tip  10 ′″ from the device  1  by, e.g., unthreading it from the section  2 . This would occur by the user rotating the tip  10 ′″ until the sections  14 ′″ are fully unthreaded from the threads of the section  2 . The user can alternatively remove the tip  10 ′″ from the device  1  by, e.g., squeezing sections  13 ′″ a  like the way shown in  FIG. 6 , and axially sliding the tip  10 ′″ away from and off of the section  2 . Once removed, the tip  10 ′″ can be safely discarded as the safety-shield  20 ″ would reduce the likelihood of being pricked by the needle N when handling the tip  10 ′″. 
       FIGS. 24 and 25  show another non-limiting embodiment of a pen needle or tip assembly according to the invention. This embodiment is similar to the previous embodiment but additionally includes a surrounding circumferential wall  26 ′″ on the safety-shield  20 ′″. The wall  26 ′″ provides stiffening to the safety-shield, functions to more securely retain the spring S 1 , and also provides an additional level of protection for the puncturing end of the needle N thereby ensuring that the safety-shield  20 ′″ cannot be deflected sideways to the point where the needle N is exposed. This modification can be utilized on any of the herein disclosed embodiments using a safety-shield to the extent desirable. 
       FIGS. 26 and 27  show another non-limiting embodiment of a pen needle or tip assembly according to the invention. This embodiment is also similar to the embodiment of  FIGS. 22 and 23  but additionally includes spring retaining projections  27   IV  and a surrounding circumferential flange  19   IV  on the body of the tip  10   IV . The flange  19   IV  and projections  27   IV  function to more securely retain the spring S 1 . This modification can be utilized on any of the herein disclosed embodiments using a safety-shield to the extent desirable. 
       FIGS. 28 and 29  show another non-limiting embodiment of a pen needle or tip assembly according to the invention. This embodiment is similar to the embodiment of  FIGS. 7-17  except that it utilizes a smaller diameter spring S 2  and additionally includes spring retaining projections  27   V  arranged on a surrounding circumferential flange  28   V  on the safety-shield  20   V . The flange  28   V  and projection  28   V  function to more securely retain the spring S 2  and also provides an additional level of protection for the puncturing end of the needle N thereby ensuring that the safety-shield  20   V  cannot be deflected sideways to the point where the needle N is exposed. This modification can be utilized on any of the herein disclosed embodiments using a safety-shield to the extent desirable. 
       FIG. 30  shows another non-limiting embodiment of a pen needle or tip assembly according to the invention. This embodiment is similar to the embodiment of  FIGS. 28 and 29  except that it utilizes an axially thicker surrounding circumferential flange  28   VI  on the safety-shield  20   VI . The flange  28   VI  and projection arranged thereon function to more securely retain the spring S 2  and also provides an additional level of protection for the puncturing end of the needle N thereby ensuring that the safety-shield  20   VI  cannot be deflected sideways to the point where the needle N is exposed. This modification can be utilized on any of the herein disclosed embodiments using a safety-shield to the extent desirable. 
       FIGS. 31 and 32  show another non-limiting embodiment of a pen needle or tip assembly according to the invention. Like other embodiments, the embodiment utilizes a system  18   V / 24   V  for locking the safety-shield  20   V  in a fully extended position so as to prevent re-use of the pen needle  10   V . This embodiment also illustrates how the pen needle  10   V  can be individually packaged. The packaging includes a removable seal RS having a pull-tap PT and a removable front or protective or outer cover PC. The removable seal RS can be a material of the type used conventionally in packaging pen needles except that it is removably adhesively attached to the distal edge of the pen needle body  13   V . The cover PC has a mechanism, e.g., projections, that allows the cover PC to be releasably retained on the tip  10   V  while protecting the safety-shield  20   V  and ensuring that the safety-shield  20   V  is not accidentally moved to the retracted position. In order to use the packaged pen needle  10   V  shown in  FIGS. 31 and 32 , the user need only remove the removable seal RS by gripping the pull-tab PT and peeling it off of the body  13   V . The user can then install the pen needle  10   V  onto the section  2  in any manner described herein. Then, the user can remove the protective cover PC and use the pen needle  10   V  for injection. The user can then re-install the protective cover PC and then remove the pen needle  10   V  from the section  2 . However, this is not necessary if the safety-shield  20   V  is in the fully extended position (see  FIG. 36 ) because deflectable members  18   V  will be positioned behind members  24   V  and prevent distal movement of the safety-shield  20   V . Instead, the user can simply remove the pen needle  10   V  from the section  2  without the protective cover PC being installed thereon. The packaging system PC/RS of this embodiment can be utilized on any of the herein disclosed embodiments, especially those using a safety-shield, to the extent desirable. 
       FIGS. 33 and 34  show another non-limiting embodiment of a pen needle or tip assembly according to the invention. This embodiment is similar to that of  FIGS. 31 and 32  except that it utilizes a removable front outer cover PC′ that extends to the seal RS (with the seal RS being adhesively attached to a distal edge of the cover PC′)—thereby completely enclosing the pen needle  10   V . The packaging thus includes a removable seal RS having a pull-tap PT and a removable front or protective or outer cover PC′. The removable seal RS can be a material of the type used conventionally in packaging pen needles except that it is removably adhesively attached to the distal edge of the pen needle body  13   V . The cover PC′ may optionally utilize a mechanism, e.g., projections, (not shown) that allows the cover PC′ to be releasably retained on the tip  10   V  while protecting the safety-shield  20   V  and ensuring that the safety-shield  20   V  is not accidentally moved to the retracted position. In order to use the packaged pen needle  10   V  shown in  FIGS. 33 and 34 , the user need only remove the removable seal RS by gripping the pull-tab PT and peeling it off of the cover PC′. Then, the user can remove the protective cover PC and use the pen needle  10   V  for injection. After use, the safety-shield  20   V  will be in the fully extended position (see  FIG. 36 ) because deflectable members  18   V  will be positioned behind members  24   V  and prevent distal movement of the safety-shield  20   V . The user can thus simply remove the pen needle  10   V  from the section  2  without the protective cover PC′ being installed thereon. The packaging system PC′/RS of this embodiment can be utilized on any of the herein disclosed embodiments, especially those using a safety-shield, to the extent desirable. 
       FIGS. 35 and 36  show the pen needle  10   V  used in the embodiments of  FIGS. 31-34  with the packaging removed. The hollow needle is not shown in cross-section. In  FIG. 35 , the safety-shield  20   V  is shown in an initial or nearly-fully extended position. In  FIG. 36 , the safety-shield  20   V  is in a fully extended and locked position. In this position, the pen needle or tip assembly  10   V  is rendered unreusable and can be safely handled and discarded. The safety-shield  20   V  moves to the position shown in  FIG. 36  automatically under the action of the spring S 2  once the force retaining the safety-shield  20   V  in the retracted position (as occurs during injection) is removed. The spring S 2  produces an expansion force sufficient to allow portions  24   V  to cause outward deflection of the deflectable members  18   V  and move to a position in front of the same. Once in front, the members  18   V  move back to an original position inwardly deflected position shown in  FIG. 36 . As can be seen in  FIG. 37 , each of the two oppositely arranged members  18   V  are integrally formed with the body of the tip  10   V . As can be seen in  FIG. 38 , the safety-shield  20   V  is a one-piece integrally formed member. Furthermore, as can be seen in  FIG. 40 , the cover PC′ is a one-piece integrally formed member. 
       FIG. 41  shows a rear end view of another non-limiting embodiment of a pen needle or tip assembly according to the invention. In this embodiment, the body of the pen needle  10   VI  is more rectangular-shaped than the oval-shape shown in  FIG. 3 . As with previous embodiments, the body utilizes sections  13   a   VI  which can be gripped by a user and squeezed together to cause the sections  13   b   VI  to expand radially outwardly and thereby cause the thread sections  14   VI  to disengage from the threads of the section  2 . The embodiment shown in  FIG. 41  does not utilize a safety-shield. 
       FIG. 42  shows a rear end view of another non-limiting embodiment of a pen needle or tip assembly according to the invention. In this embodiment, the body of the pen needle  10   VII  is similar to that shown in  FIG. 41  except that it utilizes a safety-shield (not shown). As with previous embodiments, the body utilizes sections  13   a   VII  which can be gripped by a user and squeezed together to cause the sections  13   b   VII  to expand radially outwardly and thereby cause the thread sections  14   VII  to disengage from the threads of the section  2 . The embodiment shown in  FIG. 42  utilize a safety-shield (not shown) by virtue of the fact that it includes slots  17   VII  that receive therein the legs of the safety-shield. 
       FIG. 43  shows a rear end view of another non-limiting embodiment of a pen needle or tip assembly according to the invention. In this embodiment, the body of the pen needle  10   VIII  is more rectangular-shaped than the oval-shape shown in  FIG. 3 . As with previous embodiments, the body utilizes sections  13   a   VIII  which can be gripped by a user and squeezed together to cause the sections  13   b   VIII  to expand radially outwardly and thereby cause the thread sections  14   VIII  to disengage from the threads of the section  2 . The embodiment shown in  FIG. 43  does not utilize a safety-shield. 
       FIG. 44  shows a rear end view of another non-limiting embodiment of a pen needle or tip assembly according to the invention. In this embodiment, the body of the pen needle  10   IX  is similar to that shown in  FIG. 43  except that it utilizes a safety-shield (not shown) and indented sections  13   a   IX . As with previous embodiments, the body utilizes sections  13   a   IX  which can be gripped (more easily because of the indented shape thereof) by a user and squeezed together to cause the sections  13   b   IX  to expand radially outwardly and thereby cause the thread sections  14   IX  to disengage from the threads of the section  2 . The embodiment shown in  FIG. 44  utilize a safety-shield (not shown) by virtue of the fact that it includes slots  17   IX  that receive therein the legs of the safety-shield. 
       FIG. 45  shows another non-limiting embodiment of a pen needle or tip assembly according to the invention. Like other embodiments, the embodiment utilizes a system  18   X / 24   X  for locking the safety-shield  20   V  in a fully extended position so as to prevent re-use of the pen needle  10   X . This embodiment also illustrates how the pen needle  10   X  can be individually packaged. The packaging includes a simple removable sleeve PC″. An optional removable seal RS can also 9 be utilized (not shown) similar to that used in  FIGS. 31 and 32 . The cover PC″ can also have a mechanism, e.g., projections, (not shown) that allows the cover PC″ to be releasably retained on the tip  10   X . The cover PC″ functions to protect the safety-shield  20   V  and ensures that the safety-shield  20   V  is not accidentally moved to the retracted position. In order to use the packaged pen needle  10   X  shown in  FIG. 45 , the user can then install the pen needle  10   X  onto the section  2  in any manner described herein. Then, the user can remove the protective cover PC″ and use the pen needle  10   X  for injection. The user can then re-install the protective cover PC″ and then remove the pen needle  10   X  from the section  2 . However, this is not necessary if the safety-shield  20   V  is in the fully extended position because members  24   X  will be positioned and/or locked in a recess formed in the members  18   X  and prevent distal movement of the safety-shield  20   V . Instead, the user can simply remove the pen needle  10   X  from the section  2  without the protective cover PC″ being installed thereon. The packaging system PC″ of this embodiment can be utilized on any of the herein disclosed embodiments using a safety-shield to the extent desirable. 
       FIGS. 46 and 47  show another non-limiting embodiment of a pen needle or tip assembly according to the invention.  FIG. 22  shows a side cross-section view of the pen needle or tip  10   XI  assembly which utilizes the main features of one or more previous embodiments including a safety-shield  20   VII  and a spring S 2  for biasing the shield  20   VII  towards an extended position. The safety-shield  20   VII  includes a generally circular front section  21   VII  which (in the extended position) is sized and configured to extend out past the proximal end of the needle N and is configured to cover the needle N so that the user will be less likely to be pricked by the needle N. The safety-shield  20   VII  also includes a generally circular through opening  22   VII  which in this embodiment is enlarged and which allows the needle N to pass there through when it is retracted. The safety-shield  20   VII  further also includes plural, e.g., two oppositely arranged, generally partially circular legs  23   VII  which connect the section  21   VII  to distal projections  24   VII . Each semi-circular leg  23   VII  is sized and configured to pass through and move within one of the partially circular slots  17   XI  formed in the body  13   XI  of the tip  10   XI . Each projection  24   VII  is larger, i.e., thicker, than the slot  17   XI  and is sized and configured to limit and define the axial movement/position of the safety-shield  20   VII  in the fully extended and locked position (see  FIG. 46 ). As is apparent from  FIGS. 46 and 47 , when retaining projection RP arranged on a non-continuous flange  28   VII  are releasably retained in a circumferential recess formed in the main support  11   XI , the safety-shield  20   VII  is in an initial and/or prior-use and nearly-fully extended position (see  FIG. 46 ). Moreover, openings TS (which are semi-circular as shown in  FIG. 49 ) allow the distal end of the distal portions of section  28   VII  extend therein when the safety-shield  20   VII  is moved to the retracted position (see  FIG. 47 ). However, when each projection RP extends out past the proximal end of the support  11   XI , the safety-shield  20   VII  is in a fully extended and locked position (not shown but similar to that shown in  FIG. 48 )—thereby rendering the tip  10   XI  single-use. 
       FIG. 49  shows another non-limiting embodiment of a pen needle or tip assembly according to the invention. This embodiment is similar to that shown in FIGS.  46  and  47  except that the flange  28   VIII  utilizes deflectable members DM whose free ends are releasably retained in the circumferential groove of the support  11   XI . These members DM are arranged between the non-continuous flange  28   VIII  (see  FIG. 50 ) prevent the safety-shield  20   VIII  from moving from the fully extended position shown in  FIG. 48  back to an initial position (similar to that shown in  FIG. 46 ). 
       FIGS. 51-54  show partial cross-section views of additional non-limiting embodiments of safety shields having differently textured proximal surfaces, i.e., different surface configurations for contacting a user&#39;s skin. In  FIG. 51 , the safety-shield  20   IX  has a skin contacting surface  21   IX  defined by a circular projection which surrounds the opening  22   IX . In  FIG. 52 , the safety-shield  20   X  has a skin contacting surface  21   X  defined by a concave indentation which surrounds the opening  22   X . In  FIG. 53 , the safety-shield  20   XI  has a skin contacting surface  21   XI  defined by both a circular projection and a concave indentation which surrounds the opening  22   XI . In  FIG. 54 , the safety-shield  20   XII  has a skin contacting surface  21   XII  defined by a circular configuration separate projections which surrounds the opening  22   XII . Any of these embodiments can be utilized on any of the herein disclosed embodiments using a safety-shield to the extent desirable. 
       FIGS. 55-58  show a non-limiting embodiment of a front cover or outer cap PC′″ which can be used on any of the herein disclosed oval-shaped pen needles.  FIGS. 57 and 58  are rotated 90 degrees relative to  FIGS. 55 and 56 . The front cover PC′″ can be removed from a respective pen needle and rotated 90 degrees and then reinstalled so that axial sliding on of the front cap PC′″ causes the squeezing forces shown in  FIG. 6  via a sliding-on motion. 
     The devices described herein can also utilize one or more features disclosed in prior art documents expressly incorporated by reference in pending U.S. patent application Ser. No. 11/616,195 (Publication No. 2008/0154192). This application and the documents expressly incorporated therein is hereby expressly incorporated by reference in the instant application. Furthermore, one or more of the various parts of the device can preferably be made as one-piece structures by e.g., injection molding, when doing so reduces costs of manufacture. Non-limiting materials for most of the parts include synthetic resins such as those approved for syringes, blood collection devices, or other medical devices. Furthermore, the invention also contemplates that any or all disclosed features of one embodiment may be used on other disclosed embodiments, to the extent such modifications function for their intended purpose. 
     purpose. 
     It is noted that the foregoing examples have been provided merely for the purpose of explanation and are in no way to be construed as limiting of the present invention. While the present invention has been described with reference to an exemplary embodiment, it is understood that the words which have been used herein are words of description and illustration, rather than words of limitation. Changes may be made, within the purview of the appended claims, as presently stated and as amended, without departing from the scope and spirit of the present invention in its aspects. Although the present invention has been described herein with reference to particular means, materials and embodiments, the present invention is not intended to be limited to the particulars disclosed herein; rather, the present invention extends to all functionally equivalent structures, methods and uses, such as are within the scope of the appended claims.