Abstract:
An apparatus and method for selectively orienting beveled needle tips by use of cooperatively configured, counter-rotating curved surfaces that contact and rotate the needle to a preferred angular orientation without blunting or marring the bevel edges. The counter-rotating surfaces may be selectively repositioned at different angles in order to reliably orient all needles as part of a multi-step method.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention relates to the manufacture of medical products and devices having needles with beveled tips, particularly the manufacture of medical products in which the needles have beveled tips that are desirably oriented in a preferred orientation relative to another portion of the associated product. 
       DESCRIPTION OF RELATED ART 
       [0002]    Needles for medical devices are typically made of medical grade stainless steel and have a beveled section disposed at the projecting free end of the needle. When such a needle is assembled into a medical device, it is often preferred that the beveled section be oriented in a desired rotational alignment to another part of the device, particularly where the needle is intended for vascular insertion. U.S. Pat. No. 4,436,479 discloses a device for orienting intravenous needles. 
         [0003]    A device is needed that can quickly and reliably orient needle bevels without damaging the bevel edges. Known needle alignment methods are typically capable of orienting large numbers of needles quickly with an acceptable failure rate, or of orienting a few needles slowly but with greater certainty. However, high production rates and high quality and reliability without damaging needle bevels are both desired in modern large-scale manufacturing environments. 
       SUMMARY OF THE INVENTION 
       [0004]    A device and method of use are disclosed that will quickly and reliably align a needle bevel in a preferred angular orientation to another part of a medical product during a high speed manufacturing process without damaging the edges of the needle bevels. 
         [0005]    In one embodiment of the needle, apparatus is disclosed comprising a frame having a plurality of roller heads that are each pivotably mounted to facilitate sequentially contacting a needle bevel from each of two different angular positions if needed for reasons discussed below. Similarly, a plurality of needles are desirably supported by needle holders disposed in another device (not shown) in a substantially vertical position relative to the frame, and are desirably indexed in a desired position relative to the frame with a needle bevel facing upwardly in substantial vertical alignment with each roller head. Each roller head desirably has a pair of needle-orienting rollers and is configured to be lowered when a needle is positioned beneath it for rotating the needle around its longitudinal axis to orient the bevel in a desired rotational position relative to the needle holder. 
         [0006]    In one embodiment of the invention of the invention, each roller head comprises a pair of counter-rotating rollers that cooperate to contact and rotate a needle until the needle bevel is disposed in a desired rotational position. Each roller head desirably has a longitudinal axis that lies in a plane substantially transverse to the plane of the longitudinal axis through the associated needle. (Because each needle will likely have some initial degree of “wobble” with respect to its supporting needle holder due to a slight clearance between the inside diameter of the needle holder and the outside diameter of the needle, the needle may not be perpendicular prior to engagement with the rollers.) The rollers, preferably cylinders, each comprise a curved outer surface, and the curved surfaces are oriented so that their axes of rotation are parallel and the surfaces are separated by a gap that is slightly less than the outside diameter of the needle to be oriented. The rollers are desirably supported by a frame member and are configured and installed to rotate in opposite directions at rotational speeds that provide the same linear rate of advance relative to a needle disposed between them. In one embodiment of the invention, the radius of curvature of the curved outer surface of the rollers used to orient the needle bevel are desirably equal and significantly greater than the radius of curvature of the outside surface of the needle (eg., 4-10 times the radius of curvature of the needle). Alternatively, each of the opposed curved surfaces can have a different radius of curvature if their respective rates of rotation are controlled so as to provide substantially the same linear rate of advance in relative to a needle disposed between them. 
         [0007]    In one embodiment of the invention, the counter-rotating rollers are lowered from above the needle, which is desirably supported by a needle holder in a vertical position that is cooperatively aligned with the gap space between the rollers. The rollers desirably descend at a rate that substantially matches the linear surface speed of the rollers so that the relative speed between the needle tip and the roller surfaces is effectively zero when they make contact. This rate matching allows the needle tip to be received into the gap between the rollers without sliding, scratching or grinding at the opposed points of contact between the rollers and the needle that could otherwise damage the needle bevel. 
         [0008]    As the opposed roller surfaces contact the needle and continue downwardly, and depending upon the angular relationship of the bevel to the contacting roller surfaces at the time of initial contact, the beveled needle tip is desirably pressured by the opposed roller surfaces so that the needle is rotated around its longitudinal axis until the bevel disposed in a preferred orientation (sometimes referred to as a 0° orientation) relative to the needle holder or to another reference objective. 
         [0009]    A single application of the needle orienting device of the invention is usually sufficient for properly orienting a needle bevel regardless of the initial orientation, and most starting needle bevel orientations less than + or −90° can be successfully corrected to achieve a 0° orientation with a single application. However, where the initial needle bevel orientation is very close to 90° and the rotational force component applied to each side of the needle bevel is substantially the same, the needle may resist rotational movement and be “blocked” or “wedged” between the rollers without rotation. To account for such an occurrence, the needle orienting device of the invention is preferably configured to be adaptable for use in a two-step process that will produce a different relative rotational alignment between the counter-rotating roller surfaces and the needle to produce the desired rotational movement of the needle to a 0° orientation. This can be achieved in many different ways. 
         [0010]    To deal with instances where the initial rotational alignment of the needle prevents rotation, one can modify either the needle orienting device or the needle positioning apparatus to produce a different initial rotational alignment between the needle and the counter-rotating roller surfaces. This can be done, for example, by configuring the roller support frame to allow pivoting of the parallel rotational axes of the roller surfaces and the gap between the rollers relative to the needle, which can be achieved by raising the supporting frame member and then lowering it again after the frame member has been pivoted to another position. Alternatively, or in combination with this adaptation, the needle positioning apparatus can be rotated to a different angular position relative to the counter-rotating roller surfaces, or the needle can be rotated slightly within the needle positioning apparatus to another rotational position that will allow the rollers to reposition the needle bevel to a desired orientation. 
         [0011]    In order to achieve a large production volume of needles, the preceding mechanism and principles can be easily scaled up from a single roller pair and needle to multiple roller pairs and needles. A linear array of roller surfaces having parallel rotational axes can be configured to pivot about independent axes while maintaining mutual parallelism. It is intended that this pivoting and the resulting lateral displacement of the rollers be calibrated so that each roller pair is capable of being repositioned over an adjacent needle in an array of needles. With this configuration, each needle can be oriented by two sets of roller pairs, each at differing angles relative to the needle, thereby allowing for the described multi-step process if necessary. The number of roller heads is desirably one greater than the number of needles in any one batch to accommodate adjusting each roller head from a first angular position to a second angular position relative to the needle bevel during the bevel orientation process. 
         [0012]    In one embodiment of the invention, after each needle bevel in a group of needles has been oriented by the subject apparatus to a desired rotational position relative to the needle holder supporting the needle, each needle is desirably fixed in that desired rotational position by some satisfactory method such as applying a drop of glue and spot curing it by the use of conventional means. Fixing the needle in the proper orientation is desirable to prevent the needle from again rotating due to vibration or other factors after the roller heads are raised the second time to disengage them from the needle bevel. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0013]    The apparatus of the invention is further described and explained in relation to the following drawings wherein: 
           [0014]      FIG. 1  is a front elevation view of a roller head, its constituent components, and a rack rod; 
           [0015]      FIG. 2  is a bottom perspective view of the roller head of  FIG. 1 ;  FIG. 3  is a simplified diagrammatic, front elevation view of a needle at an initial 60° orientation in relation two counter-rotating rollers; 
           [0016]      FIG. 4  is a composite view of a front elevation view of a needle at a final 0° orientation in relation to two counter-rotating rollers; 
           [0017]      FIG. 5  is a composite view of a front elevation view of a needle at an initial 90° orientation in relation to two counter-rotating rollers; 
           [0018]      FIG. 6  is a perspective view of a preferred embodiment of the apparatus; 
           [0019]      FIG. 7  is a side elevation view of the apparatus of  FIG. 6 ; 
           [0020]      FIG. 8  is a top perspective view of the apparatus of  FIG. 7 ; 
           [0021]      FIG. 9  is a rear perspective view of the apparatus of  FIG. 7 ; 
           [0022]      FIG. 10  is front perspective view of another embodiment of the apparatus of the invention that depicts a plurality of roller heads, with at least one roller head being pivoted to an alternate position disposed at a different angle of rotation in relation to the other roller heads; 
           [0023]      FIG. 11  is a top front perspective view of one simplified embodiment of a needle support assembly suitable for use with the apparatus of the invention; and 
           [0024]      FIG. 12  is a rear perspective view of the apparatus of  FIG. 6-9 . 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0025]    As shown in  FIGS. 1 and 2 , roller head  22  comprises rollers  24 , spindles  26 , idler gears  28 , drive gear  30 , and housing body  23 . The rollers  24  are cylinders which are fixed to spindles  26 . These spindles  26  each additionally support idler gears  28 , idler gears  28  being meshed together so that the rotational rates of rollers  24  are set to a fixed ratio. This ratio is defined to be that which causes the linear speed of the roller surfaces to be equal to each other. Preferably such a ratio would be 1:1 so that rollers  24  would be of equal diameter, but this is not required. Idler gears  28  enable rollers  24  to rotate in opposite directions, as indicated by arrows  82 ,  84  in  FIGS. 3-5 . Another third gear, drive gear  30 , is disposed on one of spindles  26  and interfaces with rack rod  32 . The relative motion between this drive gear  30  and rack rod  32  drives the rotation of one spindle  26  as well as roller  24  and idler gear  28  on this driven spindle. Due to the intermeshing between idler gears  28 , the other idler gear  28 , spindle  26 , and roller  24  are compelled to rotate as well. A further embodiment would be to eliminate idler gear  28  which shares spindle  26  with drive gear  30 , and relocate the remaining idler gear  28  so that it meshes with drive gear  30  in order to provide power to roller  24  which does not share spindle  26  with drive gear  30 . 
         [0026]    All of the aforementioned components are disposed within roller head  22 , which is a structure comprising body  23  that provides a bearing surface for spindles  26  and contains rollers  24 , idler gears  28 , and drive gear  30 . Additionally, pivot rod apertures  34  are provided through body  23  to receive pivot rod  38   d  ( FIG. 9 ) which controls the yawing motion of roller head  22 . Drive gear  30  is sized so that the linear speed of the outer surface of rollers  24  relative to roller head  22  will equal the speed of roller head  22  as it moves up and down rack rod  32 . This arrangement in intended to avoid relative motion between needle  25  ( FIGS. 3-5 ) and the outer surface of rollers  24  as roller head  22  lowers rollers  24  into position to engage needle  25 . 
         [0027]      FIGS. 3-5  illustrate three of an infinite number of different orientations that needle  25  may assume relative to rollers  24  during use of the disclosed method.  FIG. 3  shows a typical orientation, one that is not too close to either extreme of 0° as in  FIG. 4 , or 90° as in  FIG. 5 . Needle  25  in  FIG. 3  is shown in its un-oriented state, prior to application of the method. Once rollers  24  descend into contacting relationship to needle  25 , bevel  27  will be reoriented to the final, preferred state of 0° as seen in  FIG. 4 . If needle  25  were to begin in the 0° configuration, rollers  24  would have no effect when lowered. Likewise, rollers  24  are sometimes ineffective in reorienting needle  25  when it is at the 90° or near-90° orientation as in  FIG. 5 . This limitation is what makes a two-step approach to the orientation of needle  25  desirable. Using a two-step method, if needle  25  is initially oriented in a 90° or near-90° position, roller head  22  is desirably pivotable relative to frame  46  ( FIGS. 6-9 ) to reposition rollers  24  to another angular relationship with needle  25  that will allow rollers  24  to orient bevel  27  ( FIGS. 3 ) of needle  25  to a desired final position. It should be appreciated by those of skill in the art upon reading this disclosure in relation to the accompanying drawings that  FIGS. 3-5  are simplified diagrammatic views that are not drawn to scale, meaning for example that both the ratio of the radius of curvature of rollers  24  to that of needle  25  and the separation between rollers  24  in gap  85  will desirably be relatively greater than shown in  FIGS. 3-5 . Gap  85  will desirably be larger than shown (by comparison) but slightly smaller than the outside diameter of needle  25  to facilitate engagement with needle  25  at a point lower on bevel  27  than shown to rotate needle  25  more effectively and to accommodate some degree of “wobble” of needle  25  from a strictly vertical position as it is supported in the needle holder prior to repositioning bevel  27 . 
         [0028]    Apparatus  20  for multiple simultaneous needle orientations is presented in  FIG. 6 . Two roller heads  22  are displayed for simplicity, but apparatus  20  is intended to support many more roller heads  22  in a similar configuration. In  FIG. 6 , needle positioning bar  60  attached to frame  46  and having a single indexing notch  62  is provided to facilitate test placement of a single needle/needle holder/support assembly beneath a roller head  22 . One such single needle/needle holder/support assembly suitable for test use is described below in relation to  FIG. 11 . Roller heads  22  are positioned in the apparatus by way of their rack rods  32 . Each rack rod is fixed to frame  46  and provides an axis about which roller head  22  may pivot. Roller heads  22  are supported vertically by lift bar  42  which is motivated by actuator  44 . Lift bar  42  raises roller heads  22  all at once, and once needles  25  are in their positions below rollers  24 , lift bar  42  is lowered, allowing roller heads  22  to descend under their own weight. Springs  48  ( FIG. 9 ) provide additional downward force to assist rollers  24  in orienting needle bevels  27  ( FIGS. 3, 5 ). The upward and downward motion of rollers  24  relative to needle  25  within a predetermined range of travel is depicted in simplified diagrammatic form by arrow  86  in  FIG. 3 . 
         [0029]      FIG. 9  allows for a closer view of roller heads  22  and their related components when installed. As described previously, roller heads  22  are laterally fixed about their rack rods  32 , and supported by lift bar  42 . Pivot rods  38  are disposed through pivot rod apertures  34  in the end of body  23  opposite rollers  24 , These pivot rods  38  are all connected to pivot bar  40  as seen in  FIG. 8 . This pivot bar  40  selectively controls the angle of roller heads  22  by translating parallel to its own long axis, thereby moving pivot rods  38  and forcing roller heads  22  to pivot about their rack rod  32 . 
         [0030]    Starting with an already-raised array of roller heads  22 , pivot bar  40  is desirably moved so that roller heads  22  are pivoted to another angle with respect to frame  46 . This positions an array of needles (not shown except in  FIGS. 3-5 ) below roller heads  22  so that each needle  25  is aligned with the space between rollers  24 , retracting actuator  44  which lowers lift bar  42  and roller heads  22 , extending actuator  44  to raise the bar  42  and roller heads  22 , translating pivot bar  40  so that roller heads  22  are perpendicular to the pivot bar&#39;s long axis, retracting actuator  44  which lowers lift bar  42  and roller heads  22  onto needles  25 , extending actuator  44  to raise lift bar  42  and roller heads  22 , and removing the array of oriented needles  25 . 
         [0031]      FIG. 10  depicts another embodiment of apparatus  50  of the invention in which the pivotal movement of roller head  52  relative to other roller heads  54  is further depicted. 
         [0032]      FIG. 11  depicts a needle  70  having projecting needle bevel  72 . Needle  70  is initially rotatably disposed in relation to and is supported in a substantially vertical orientation by needle holder  74 . Needle  70  and needle holder  74  are maintained in a desired positional relationship to apparatus  20  of the invention by needle support member  76  of a type that is suitable for use in apparatus  20  of the invention as configured and previously described in relation to  FIG. 6 , More particularly, in the embodiment shown in  FIG. 11 , needle support member  76  is configured as a test piece to fit inside indexing notch  62  in positioning bar  60 . As previously mentioned, needle  70  may be able to “wobble” to some extent inside needle holder  74  because rotational movement of needle  70  within needle holder  74  is desirably permitted to allow the orientation of needle bevel  72  to be repositioned relative to needle holder  74 , after which needle  70  can be spot glued to needle holder  74  to prevent further rotational movement of needle  70  relative to needle holder  74 . Alternatively, needle  70  can be set in a fixed position relative to needle holder  74  if needle holder  74  is rotatable relative to needle assembly  78  in such manner that their relative rotational positions can be fixed prior to properly orienting needle bevel  72 . 
         [0033]    Other alterations and modifications of the subject invention will likewise become apparent to those of ordinary skill in the art upon reading this disclosure in relation to the accompanying figures of the drawings, and it is intended by the inventors that the scope of the invention as disclosed here be limited only by the broadest possible interpretation of the association claims to which the inventors are legally entitled.