Abstract:
A surgical retractor includes a retractor frame, a plurality of blades for engaging tissue, and a coupling arrangement. Each blade of the plurality of blades defines a longitudinal blade axis. The coupling arrangement is carried by the retractor frame and releasably couples a first blade of the plurality of blades with the retractor frame through translation of the first blade in a direction generally perpendicular to the longitudinal blade axis of the first blade.

Description:
FIELD 
       [0001]    The present disclosure relates to a surgical retractor, and more particularly to a surgical retractor including front-loading blades. 
       BACKGROUND 
       [0002]    This section provides background information related to the present disclosure which is not necessarily prior art. 
         [0003]    Various devices and associated methods are known for providing access to portions of the human body during a surgical procedure. Such devices include, for example, forceps, dilators and retractors. A surgical retractor may include at least two blades that can be inserted into the human body through an incision during a surgical procedure. The blades can be separated or retracted in order to open or otherwise enlarge the incision, thus providing improved access to the surgical site. While known retractors have proven to be acceptable for their intended purposes, a continuous need for improvement in the art remains. 
       SUMMARY 
       [0004]    This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features. 
         [0005]    According to one particular aspect, the present disclosure provides a surgical retractor. The surgical retractor includes a retractor frame, a plurality of blades for engaging tissue, and a coupling arrangement. 
         [0006]    Each blade of the plurality of blades defines a longitudinal blade axis. The coupling arrangement is carried by the retractor frame and releasably couples a first blade of the plurality of blades with the retractor frame through translation of the first blade in a direction generally perpendicular to the longitudinal blade axis of the first blade. 
         [0007]    According to another particular aspect, the present disclosure provides a surgical retractor. The surgical retractor includes a retractor frame, a plurality of blades for engaging tissue, and a coupling arrangement. Each blade of the plurality of blades defines a longitudinal axis and includes a mounting portion having a pair of blade arms. The coupling arrangement is carried by the retractor frame and releasably couples a first blade of the plurality of blades with the retractor frame through translation of the first blade in a direction generally perpendicular to the longitudinal blade axis of the first blade. The coupling arrangement including a pair of coupling arms moveable relative to one another in a direction generally perpendicular to the longitudinal axis of the first blade. 
         [0008]    According to yet another particular aspect, the present disclosure provides a surgical retractor. The surgical retractor includes a retractor frame, a plurality of blades for engaging tissue, and a corresponding plurality of coupling arrangements carried by the retractor frame. Each blade of the plurality of blades defines a longitudinal axis and includes a mounting portion having a pair of blade arms. Each coupling arrangement of the corresponding plurality of coupling arrangement is operative to releasably couple a corresponding blade of the plurality of blades with the retractor frame through translation of the corresponding blade in a direction generally perpendicular to the longitudinal axis of the corresponding blade. 
         [0009]    Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
     
    
     
       DRAWINGS 
         [0010]    The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure. 
           [0011]      FIG. 1  is a perspective view of a surgical retractor in accordance with the principles of the present disclosure. 
           [0012]      FIG. 2  is a top view of the surgical retractor of  FIG. 1 . 
           [0013]      FIG. 3  is a front view of a coupling arrangement of the surgical retractor of  FIG. 1 , the coupling arrangement shown in a first configuration. 
           [0014]      FIG. 4  is a front view of the coupling arrangement of  FIG. 3 , the coupling arrangement shown in a second configuration. 
           [0015]      FIG. 5  is a cross-sectional view of the connector assembly of  FIG. 4 , taken along the line  5 - 5  of  FIG. 4 . 
           [0016]      FIG. 6  is a perspective view of another surgical retractor in accordance with the principles of the present disclosure. 
           [0017]      FIG. 7  is a top view of the surgical retractor of  FIG. 6 . 
           [0018]      FIG. 8A  is a cross-sectional view of a coupling arrangement of the surgical retractor of  FIG. 6  taken along the line  8 A- 8 A of  FIG. 6 , the coupling arrangement shown in a first configuration. 
           [0019]      FIG. 8B  is a cross-sectional view of the coupling arrangement of the surgical retractor of  FIG. 6  taken along the line  8 B- 8 B of  FIG. 6 , the coupling arrangement shown in a first configuration. 
           [0020]      FIG. 9A  is a cross-sectional view similar to  FIG. 8A , the coupling arrangement shown in a second configuration. 
           [0021]      FIG. 9B  is a cross-sectional view similar to  FIG. 8B , the coupling arrangement shown in a second configuration. 
       
    
    
       [0022]    Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. 
       DETAILED DESCRIPTION 
       [0023]    Example embodiments will now be described more fully with reference to the accompanying drawings. 
         [0024]    With initial reference to  FIG. 1  of the drawings, a surgical retractor constructed in accordance with the principles of the present disclosure is illustrated and identified at reference character  10 . According to one exemplary use, the retractor  10  may be used for accessing a lumbar intervertebral disc space (not shown) during a surgical procedure in order to facilitate the placement of an implant into the lumbar intervertebral disc space. It will be appreciated, however, that the retractor  10  may be adapted for use in many different applications, such as accessing the posterior of a vertebra body or disc space, accessing a cervical vertebra body or disc space, or accessing various other portions of the human body during a surgical procedure. 
         [0025]    The surgical retractor  10  may include a frame  12 , a coupling arrangement  14 , and a blade  16 . For clarity, the surgical retractor  10  is shown with one blade  16 ; however, in one configuration the retractor  10  may include four coupling arrangements  14  and four blades  16 . It will also be appreciated that the retractor may include more or less than four coupling arrangements  14  and more or less than four blades  16  within the scope of the present disclosure. In this regard, the number of coupling arrangements  14  may be equal to the number of blades  16 . 
         [0026]    The frame  12  may be generally ring-shaped, defining a central opening  18 . The central opening  18  may define a first longitudinal axis  22  and may allow for viewing a surgical site. In this regard, a lower side  21  (relative to the view in  FIG. 1 ) of the frame  12  may generally face the surgical site, while an upper side  23  of the frame  12  may generally face away from the surgical site. In one configuration, the frame  12  may further include at least one pair of opposing grooves or channels  20  for mounting the coupling arrangement  14  to the frame  12 . The channels  20  may extend in a direction substantially perpendicular to the first longitudinal axis  22 . 
         [0027]    The coupling arrangement  14  may be adjustably mounted to the frame  12 . The location of the coupling arrangement  14  relative to the frame  12  can be selectively adjusted in a direction substantially perpendicular to the first longitudinal axis  22  by sliding or otherwise moving the coupling arrangement  14  within the channels  20 . In this regard, the retractor  10  may include a first driving member  24  and a second driving member  25 . The first driving member  24  may include a first gear portion  45  and may be mounted to the frame  12  for rotation about a first axis of rotation  29 . The first axis of rotation  29  may be substantially parallel to the first longitudinal axis  22 . The second driving member  25  may include a second gear portion  47  and a threaded portion  41 . The second driving member  25  may be mounted to the frame  12  and threadably mounted to the coupling arrangement  14  for rotation about a second axis of rotation  31 . The second axis of rotation  31  may be substantially perpendicular to the first axis of rotation  29 . The first gear portion  45  may be meshingly engaged with the second gear portion  47 , such that rotation of the first driving member  24  causes rotation of the second driving member  25 , including causing the threaded portion  41  to threadably engage the coupling arrangement  14 . Threaded engagement of the threaded portion  41  to the coupling arrangement  14  may cause the coupling arrangement to move within the channels  20  of the frame  12 . 
         [0028]    The coupling arrangement  14  may include a carrier  26 , a connector housing  27 , a connector  28 , a biasing member  30 , and a locking element  32 . In an assembled configuration, the carrier  26  may be adjustably coupled to the frame  12 . As illustrated in  FIGS. 1 and 2 , in one configuration, the carrier  26  may be adjustably disposed within the channels  20 , as described above. 
         [0029]    The connector housing  27  may be pivotably mounted to the carrier  26  for rotation about a third axis of rotation  43 . The third axis of rotation  43  may be substantially perpendicular to the first longitudinal axis  22  and substantially perpendicular to the second axis of rotation  31 . In this regard, as illustrated in  FIG. 5 , the carrier  26  may include a threaded aperture  33 , and the connector housing  27  may include a stem portion  35  having an open-ended channel  37 . The channel  37  may define a cross-sectional area A 1 . A screw, bolt, or other similar mechanical fastener  39  may be threadably received by the threaded aperture  33  and extend into the channel  37 . The fastener  39  may include an end portion  49  having a cross-sectional area A 2  sized and shaped so as rotatably mate within the channel  37 . Rotating the fastener  39  may cause the end portion  49  to contact the stem portion  35  of the connector housing  27 , and thereby cause the connector housing to rotate or pivot about the third axis of rotation  43 . 
         [0030]    The connector  28  may be coupled to the connector housing  27 . In this regard, the connector housing  27  may further include an opening  36 . In an assembled configuration, the opening  36  may generally face the central opening  18  of the frame  12 . The connector  28  may be located within and extend from the opening  36 , and may include a first arm  40   a  and a second arm  40   b . The first and second arms  40   a ,  40   b  may be operable to pivot about a fourth axis of rotation  44  that is substantially parallel to the first longitudinal axis  22  of the frame  12 . The first and second arms  40   a ,  40   b  may each include an outwardly projecting flange or lipped portion  42   a ,  42   b , respectively, and concave or otherwise recessed portions  46   a ,  46   b , respectively. As will be explained in more detail below, the outwardly projecting flange or lipped portions  42   a ,  42   b  may secure the blade  16  to the connector  28 . 
         [0031]    The biasing member  30  may be located between the first and second arms  40   a ,  40   b  and may be operable to bias the connector  28  into engagement with the blade  16 . As illustrated, in one configuration the biasing member  30  may be a substantially U-shaped leaf spring disposed between the first and second arms  40   a ,  40   b  and operable to bias the first arm  40   a  relative to the second arm  40   b . In this regard, the biasing member  30  may be operable to bias the first arm  40   a  away from the second arm  40   b  and about the fourth axis of rotation  44 . While the biasing member  30  is shown as being a leaf spring, it will be appreciated that the biasing member  30  may have other configurations, such as a helical spring, within the scope of the present disclosure. It will also be appreciated that the connector  28  may be formed from a material having spring-like characteristics, such that construct of the connector  28  biases the first arm  40   a  away from the second arm  40   b  in a leaf spring-like manner. 
         [0032]    The locking element  32  may include a head portion  50 , an intermediate portion  52 , and a lock portion  54 . The locking element  32  may be rotatably coupled to the carrier  26  for rotation about a fifth axis of rotation  56 . The fifth axis of rotation  56  may be substantially parallel to the fourth axis of rotation  44 . As illustrated, in one configuration the head portion  50  is located at the upper side  23  of the frame  12  and includes a driving feature such as a hex head, a socket, or other multi-lobular aperture for selectively rotating the locking element  32  about the fifth axis of rotation  56 . The intermediate portion  52  extends between the head portion  50  and the lock portion  54  and may be threadably engaged with the connector housing  27 . 
         [0033]    As illustrated in  FIGS. 3 and 4 , the lock portion  54  may include a substantially spherical or dome-like surface  58  located between the first and second arms  40   a ,  40   b  of the connector  28 . The dome-like surface  58  may have a diameter Dl. With reference to  FIG. 3 , in a first or unlocked configuration, the surface  58  of the lock portion  54  may be located in, and adjacent to, the recessed portions  46   a ,  46   b  of the first and second arms  40   a ,  40   b . As will be explained in more detail below, in the unlocked configuration, the locking element  32  may allow translation of the blade  16  relative to the first and second arms  40   a ,  40   b  in a direction substantially parallel to the fifth axis of rotation  56 . In a locked configuration, the locking element  32  may prevent translation of the blade  16  relative to the first and second arms  40   a ,  40   b  in a direction substantially parallel to the fifth axis of rotation  56 . As will be explained in more detail below, by rotating the locking element  32  about the fifth axis of rotation  56 , the threaded engagement between the locking element  32  and the connector housing  27  may cause the locking element  32  to move along (i.e., parallel to) the fifth axis of rotation  56 , such that the lock portion  54  exits the recessed portions  46   a ,  46   b . As illustrated in  FIG. 4 , when the lock portion  54  exits the recessed portions  46   a ,  46   b , the dome-like surface  58  may force the first arm  40   a  away from the second arm  40   b  and into the locked configuration. 
         [0034]    The blade  16  may extend longitudinally between a proximal end  60  and a distal end  62 , along a second longitudinal axis  64 . As illustrated in  FIG. 1 , in the assembled configuration, the second longitudinal axis  64  of the blade  16  may be substantially parallel to the fifth axis of rotation  56 , such that a first side  66  of the blade  16  faces the opening  18 , and a second side  68  of the blade  16  faces the connector  28 . The first side  66  of the blade  16  may be substantially concave, such that the first sides  66  of the blades  16  collectively define a circular shape, as illustrated in  FIG. 2 . 
         [0035]    The second side  68  of the blade  16  may include a mounting portion  70 . In one configuration, the mounting portion  70  is located at the proximal end  60  of the blade  16 . The mounting portion  70  may include a first arm  72  and a second arm  74 . The first arm  72  may include a first lipped or flanged portion  76  and the second arm  74  may include a second lipped or flanged portion  78 , such that the first and second arms  72 ,  74  and the first and second flanged portions  76 ,  78  collectively define a substantially U or C-shaped mounting portion. Specifically, the mounting portion  70  may define a substantially C-shaped cross section extending along the second longitudinal axis  64  of the blade  16 . The C-shaped cross section, including the first and second arms  72 ,  74  and the first and second flanged portions  76 ,  78 , may have a length extending less than or equal to fifty millimeters in the direction substantially parallel to the second longitudinal axis  64 . In one particular configuration, the C-shaped cross section may have a length equal to ten millimeters. As explained in more detail below, the length of the C-shaped cross section may in part define a distance by which the blade  16  can translate or otherwise move relative to the connector  28  along the second longitudinal axis  64 . 
         [0036]    In the assembled configuration, the mounting portion  70  of the blade  16  may be adjustably coupled to the connector  28 . In this regard, the first and second arms  72 ,  74  of the mounting portion  70  may be coupled to the first and second arms  40   a ,  40   b , respectively, of the connector  28 , such that the first and second flanged portions  76 ,  78  mate with the lipped portions  42   a ,  42   b , respectively, of the connector  28 . 
         [0037]    Operation of the surgical retractor  10  will now be described in more detail. The surgical retractor  10  may be positioned over an incision or other surgical access site such that the first longitudinal axis  22  of the central opening  18  is substantially aligned with the incision. At least one of the blades  16  may be positioned within the opening  18  and/or the incision such that the second longitudinal axis  64  of the blade  16  is substantially aligned, or otherwise parallel to, the first longitudinal axis  22  of the central opening. The blade  16  may be moved in a direction substantially perpendicular to the second longitudinal axis  64  and substantially perpendicular to the third axis of rotation  43 , such that the mounting portion  70  engages the connector  28 . In this regard, as illustrated in  FIG. 5 , the user may apply a force F 1  on the blade  16  in a direction extending away from, and substantially perpendicular to, the first longitudinal axis  22 , such that the first and second flanged portions  76 ,  78  of the mounting portion  70  contact the first and second lipped portions  42   a ,  42   b  of the connector  28 . As illustrated in  FIG. 3 , the first and second flanged portions  76 ,  78  may apply a force F 2  on the arms  40   a ,  40   b  of the connector  28  that is opposite a biasing force F 3  of the biasing member  30 . The force F 2  may overcome the biasing force F 3 , such that the first arm  40   a  moves toward the second arm  40   b  and/or about the fourth axis of rotation  44 . The mounting portion  70  may be moved away from, and substantially perpendicular to, the first longitudinal axis  22  until the mounting portion  70  is coupled to the connector  28 . 
         [0038]    With the mounting portion  70  coupled to the connector  28 , the distance between the distal end  62  of the blade  16  and the connector  28  can be adjusted along the second longitudinal axis  64  by sliding or otherwise translating the mounting portion  70  relative to the connector  28  along the C-shaped cross section of the mounting portion  70 . In this regard, the C-shaped cross section of the mounting portion  70  may include a closed end that contacts a distal end of the arms  40   a ,  40   b  to limit the amount of relative movement between the blade  16  and the connector  28  along the second longitudinal axis  64 . When the distal end  62  of the blade  16  has been positioned at a desired location relative to the incision, the user may adjust the locking element  32  to secure the mounting portion  70  relative to the connector  28  and prevent movement of the blade  16  along the second longitudinal axis  64 . Specifically, the user may rotate the locking element  32  about the fifth axis of rotation  56  from the unlocked position to the locked position, as described above, such that the lock portion  54  exits the recessed portions  46   a ,  46   b  of the first and second arms  40   a ,  40   b , respectively. As illustrated in  FIG. 4 , the lock portion  54 , including the surface  58 , may apply a force F 4  on the first and second arms  40   a ,  40   b  that generates and/or increases a normal force between the arms  40   a ,  40   b  and the arms  72 ,  74 . The normal force between the arms  40   a ,  40   b  and the arms  72 ,  74  may increase a frictional force between the arms  40   a ,  40   b  and the arms  72 ,  74  that is operable to prevent the blade  16  from moving in a direction substantially parallel to the second longitudinal axis  64  of the blade  16 . 
         [0039]    When it is desired to adjust the position of the mounting portion  70  relative to the connector  28  along the second longitudinal axis  64 , or otherwise remove the blade  16  from the connector  28 , the user may rotate the locking element  32  from the locked position to the unlocked position such that the lock portion  54  is received between the recessed portions  46   a ,  46   b  of the first and second arms  40   a ,  40   b . In this way, the frictional force between the arms  40   a ,  40   b  of the connector  28  and the arms  72 ,  74  of the mounting portion  70  is reduced, allowing the user to slide the mounting portion  70  relative to the connector  28 . 
         [0040]    With reference to  FIGS. 6 through 9B  of the drawings, another configuration of a surgical retractor constructed in accordance with the principles of the present disclosure is illustrated and identified at reference character  100 . The surgical retractor  100  may be substantially similar to the surgical retractor  10 , except as otherwise provided herein. Accordingly, similar features will not be described again in detail. 
         [0041]    The surgical retractor  100  may include a coupling arrangement  114  and a blade  116 . The coupling arrangement  14  may include a connector  127  and a locking assembly  132 . As illustrated in  FIGS. 8A through 9B , the connector  127  may be adjustably mounted to the carrier  26 , and may include a first arm  140   a , a second arm  140   b , a guide  143 , and an aperture  145 . The first and second arms  140   a ,  140   b  may be pivotably mounted to and/or integrally formed with the connector  127 , and may include an inwardly projecting flange or lipped portion  146 ,  148 , respectively, for securing the blade  116  to the connector  127 . The guide  143  may be a flange or fin-type element extending between and substantially parallel to the first and second arms  140   a ,  140   b . The guide  143  may be integrally formed with the connector  127 . The aperture  145  may include a first and second arcuate surfaces  147 ,  149  and first and second stop surfaces  151   a ,  151   b  ( FIG. 9B ). The first and second arcuate surfaces  147 ,  149  may be concave and include first and second radii R 1 , R 2 , respectively. The first and second stop surfaces  151   a ,  151   b  may extend from and between the first and second arcuate surfaces  147 ,  149 . Operation of the connector  127  will be described in more detail below. 
         [0042]    The locking assembly  132  may include a housing  150 , a stem element  152 , a locking element  154 , and a pin member  156 . The housing  150  may include an opening  158 , a first aperture  160  and a second aperture  162 . The opening  158  may be sized and shaped to adjustably receive the connector  127 . The first aperture  160  may be a substantially oblong slot located on a first side of the housing  150 . The first aperture  160  may include a length L 1  extending in a direction substantially perpendicular to the first longitudinal axis  22  and substantially perpendicular to the second axis of rotation  31 . The second aperture  162  may be a generally L-shaped aperture located on a second side of the housing  150 , generally opposite the first side of the housing. In this regard, the first side of the housing  150  may be substantially parallel to the second side of the housing  150 . 
         [0043]    The stem element  152  may include a cross-sectional shape that is similar to the shape of the aperture  145  such that, in an assembled configuration, the stem element  152  is received within the aperture  145 . In this regard the stem element  152  may include third and fourth arcuate surfaces  170 ,  172  ( FIG. 9B ) and third and fourth stop surfaces  174 a,  174 b. The third and fourth arcuate surfaces  170 ,  172  may be convex and include third and fourth radii R 3 , R 4 , respectively. The third arcuate surface  170  may substantially define a cam portion  175  ( FIG. 8A ) of the stem element  152 . The first and second stop surfaces  151   a ,  151   b  may extend from and between the third and fourth arcuate surfaces  170 ,  172 . In an assembled configuration, the stem element  152  may be rotatably received in the aperture  145  of the connector  127 . 
         [0044]    A first end of the stem element  152  may include a first bore  180  operable to receive the pin member  156 . In one configuration, the first bore  180  may be disposed in the cam portion  175  of the stem element  152 . A second end of the stem element  152  (generally opposite the first end of the stem element  152 ) may include a second bore  182  operable to receive the locking element  154 . The second bore  182  may include a flat  184 . The locking element  154  may include a head portion  186 , a stem portion  188 , and an arm portion  190 . The head portion  186  may include a hex head, a socket, or other driving feature for operatively rotating the locking element  154  with a wrench or other suitably driving tool. The stem portion  188  may extend from the head portion  186  and include a flat  192 . The arm portion  190  may extend generally perpendicularly from the stem portion  188 . 
         [0045]    In an assembled configuration, the pin member  156  may be mounted within the first bore  180  of the stem element  152 . The locking element  154  may be mounted within the second bore  182  of the stem element  152 , such that the flat  184  is aligned with the flat  192  to prevent the locking element  154  from rotating within the second bore  182 . In the assembled configuration, the arm portion  190  of the locking element  154  may be located adjacent to the cam portion  175  of the stem element  152 . The stem element  152  may be mounted within the aperture  145  of the connector  127  for rotation about a seventh axis of rotation  191 . The connector  127  may be movably or otherwise adjustably mounted to the housing  150 , such that the first and second arms  140   a ,  140   b  extend from the opening  158  of the housing  150 . In the assembled configuration, the pin member  156  may extend into the first aperture  160  of the housing  150 , and the arm portion  190  of the locking element  154  may extend into the second aperture  162  of the housing  150 . 
         [0046]    The blade  116  may be substantially similar to the blade  16 . Accordingly, like reference numerals will be used to describe similar features. The blade  116  may include a mounting portion  198  having a generally Y-shaped cross section. In this regard, the mounting portion  198  may include a first arm  200 , a second arm  202 , and an opening or slot  204  extending between the first and second arms  200 ,  202 . The first arm  200  may include a first outwardly extending lip or flange portion  206  and the second arm  202  may include a second outwardly extending lip or flange  208 . 
         [0047]    Operation of the surgical retractor  100  will now be described in more detail. Operation of the surgical retractor  100  may be substantially similar to the operation of surgical retractor  10 . Accordingly, only the differences will be described in detail herein. 
         [0048]    The blade  116  may be moved in a direction substantially perpendicular to the second longitudinal axis  64 , such that the mounting portion  198  engages the connector  127 . In this regard, the user may apply a force F 1  on the blade  116  in a direction extending away from, and substantially perpendicular to, the first longitudinal axis  22  until the first and second arms  200 ,  202  of the mounting portion  198  contact the first and second arms  140   a ,  140   b  of the connector  127 , and the guide  143  is received by the slot  204 . 
         [0049]    With the mounting portion  198  coupled to the connector  127 , the distance between the distal end  62  of the blade  116  and the connector  127  can be adjusted along the second longitudinal axis  64  by sliding or otherwise translating the mounting portion  198  relative to the connector  127 . In this regard, the slot  204  of the mounting portion  198  may include a closed end. The closed end may contact the guide  143  to limit the amount of relative movement between the blade  116  and the connector  127 . When the distal end  62  of the blade  16  has been positioned at a desired location, the user may rotate the stem element  152  about the seventh axis of rotation  191 , and within the aperture  145  of the connector  127 . Specifically, the user may use a wrench, or other suitable driving tool, to rotate the locking element  154 , and in turn the stem element  152 . As the stem element  152  is rotated, the pin member  156  may slide or otherwise translate within the first aperture  160 , and the arm portion  190  of the locking element  154  may slide or otherwise translate within the second aperture  162  of the housing  150 . The pin member  156  and the locking element  154  may, in turn, cause the housing  150  to slide or otherwise translate relative to the connector  127 . The housing  150  may force the first arm  140   a  towards the second arm  140   b , and thereby secure the mounting portion  198  of the blade  116  between the first and second arms  140   a ,  140   b , to prevent the blade  116  from moving in a direction substantially parallel to the second longitudinal axis  64 . 
         [0050]    The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure. 
         [0051]    Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail. 
         [0052]    The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed. 
         [0053]    When an element or layer is referred to as being “on,” “engaged to,” “connected to,” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
         [0054]    Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments. 
         [0055]    Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,” “lower,” “above,” “upper,” and the like, may be used herein for ease of description to describe one element or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.