Abstract:
A blade assembly for a surgical scalpel that includes a blade carrier with a blade attached one end thereof. A protective cover covers the blade and blade holder. The blade carrier has a detent and the protective cover has a latch in releasable engagement with the detent to hold the protective covering in a protecting position covering said blade assembly and said blade. Also a surgical scalpel is disclosed which comprises a handle having two prongs extending from one end thereof, one of said prongs being resilient, the other of said prongs having a latching tooth at its distal end, A disposable blade assembly includes a blade carrier having a surgical blade attached thereto. The blade carrier has a surface defining a window with a shoulder into which said prongs extend with said latching tooth engaging said shoulder when said handle is inserted into said blade carrier. A protective cover covers the blade carrier and is moveable between a covered position covering the blade and a cutting position in which the blade is exposed for use.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]     This application claims the priority of U.S. patent application Ser. No. 60/796,807 filed May 1, 2006, the disclosure of which is hereby incorporated by reference. 
     
    
     TECHNICAL FIELD  
       [0002]     The present invention relates generally to surgical scalpels, and in particular, to scalpels having a reusable handle and a disposable blade assembly.  
       BACKGROUND  
       [0003]     Conventional surgical instruments present a significant risk of harm to surgeons, nurses and other medical personnel. The risk of getting cut or punctured by an exposed blade increases during medical emergencies when various surgical instruments are quickly passed from person to person. Exposed blades can also compromise the integrity of surgical gloves during a procedure, which may increase the risk of infection via contact with blood or other bodily fluids.  
         [0004]     Retractable blade guards on surgical scalpels are well known. However, there remains a need for a scalpel and disposable blade assembly that guards against inadvertent injury yet can be assembled quickly, easily, and reliably.  
       SUMMARY  
       [0005]     According to one aspect there is provided a blade assembly for a surgical scalpel comprising a blade carrier and a blade attached to the blade carrier at one end thereof. A protective cover covering the blade and blade holder is provided. The blade carrier has a detent and the protective cover has a latch in releasable engagement with the detent to hold the protective covering in a protecting position covering the blade assembly and the blade.  
         [0006]     According to another aspect, there is provided a surgical scalpel comprising a handle having two prongs extending from one end thereof, one of the prongs being resilient, the other of the prongs having a latching tooth at its distal end. A disposable blade assembly is provided which includes a blade carrier having a surgical blade attached thereto. The blade carrier has a surface defining a window with a shoulder into which the prongs extend with the latching tooth engaging the shoulder when the handle is inserted into the blade carrier.  
         [0007]     According to yet another aspect there is provided a surgical scalpel comprising a handle having two prongs extending from one end thereof. One of the prongs has a latching tooth at its distal end, and the prongs are separated by a channel extending into the handle. A disposable blade assembly includes a blade carrier having a surgical blade attached thereto. The blade carrier has a surface defining a window with a shoulder into which the prongs extend with the latching tooth engaging the shoulder when the handle is inserted into the blade carrier.  
         [0008]     According to a still further aspect there is provided a surgical scalpel comprising a disposable blade assembly having a first end and a second end defining at least one end of a mounting window. A protective sleeve is provided on the blade assembly. A reusable handle has a distal end and a proximal end defining a mounting portion that releasably engages the mounting window, wherein the mounting portion engages the mounting window with an audible click that ensures complete engagement.  
         [0009]     It will thus be appreciated that a significantly improved combination of a handle and a disposable blade assembly is described herein. In the preferred embodiment the handle includes at least two prongs, one of which is resilient and outwardly biased. The blade assembly includes a blade, a blade carrier and a retractable protective sleeve with a dependant tooth. The retractable protective sleeve is movable over the surface of the scalpel&#39;s handle portion to selectively expose and/or cover the blade as needed. The user slides the sleeve and positions the tooth for selectively establishing and reestablishing at least two detent conditions: (1) the covered condition and (2) a cutting condition. The protective sleeve completely covers the blade for disposal, while the handle portion of the scalpel is retained for reuse. The particular configuration of the handle and the blade assembly combination provides an extra measure of security by creating an audible “click” when the blade assembly is fully mounted to the handle portion. This “click” assures the user that the blade assembly has properly engaged the handle portion and that the scalpel is ready for use. Preferably, the structure involved in completing the “clicking” configuration also ensures that the blade assembly cannot be accidentally disengaged from the handle. The scalpel and blade assembly, including the protective sleeve, can be scaled down (miniaturized) for surgical applications that require a longer, slimmer scalpel. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]      FIG. 1  is a side view, partially in section, of a surgical scalpel according to one embodiment;  
         [0011]      FIG. 2  is a side view of the handle of the scalpel of  FIG. 1 ;  
         [0012]      FIG. 3  is a side view of a disposable blade assembly usable with the handle of  FIG. 2 ;  
         [0013]      FIG. 4  is a side view of a handle insert according to another embodiment;  
         [0014]      FIG. 5  is a side view showing the handle insert of  FIG. 4  with a plastic over-coating;  
         [0015]      FIGS. 6   a - 6   g  show one embodiment of the attachment of the resilient prong to the handle body;  
         [0016]      FIGS. 7   a - 7   c  show another embodiment of the attachment of the resilient prong to the handle body;  
         [0017]      FIGS. 8   a - 8   e  show the various components of a surgical scalpel according to one embodiment;  
         [0018]      FIGS. 9   a - 9   e  show the assembly, disassembly and operation of the scalpel;  
         [0019]      FIGS. 10   a - 10   b  show a user engaging the protective sleeve to move it between its two positions;  
         [0020]      FIGS. 11, 12  and  13  show various embodiments of various features of the scalpel; and  
         [0021]      FIGS. 14   a - 14   d  show miniaturized components of the scalpel.  
         [0022]      FIG. 15  is a partial exploded view of another embodiment of a blade carrier and protective cover. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0023]     Referring to the drawings and particularly  FIGS. 1-3 , a scalpel  2  generally includes a handle  4  with a proximal end  6  and a distal end  8 . A blade assembly  10  having a surgical blade  12  attached thereto is removeably connected to the handle  4 . A protective sleeve  14  surrounds the blade assembly  10  as shown.  
         [0024]     The distal end  8  defines the mounting portion  16  of the handle and features two mounting prongs  18  and  20 . One prong  18  is rigid and is equipped with a locking tooth  22 . The second prong  20  is resilient and includes a leading ramp portion  24  to facilitate insertion into the blade assembly  10 . The resilient prong  20  is generally outwardly biased when the handle is inserted into the blade assembly  10 . The resilient prong  20  may be added to the handle  4  as a separate component during manufacture as shown in  FIG. 2 . Alternatively, as shown in  FIGS. 4 and 5 , the handle  4  may have an inner core  26  of a suitable metal such as stainless steel where both the rigid prong  18  and resilient prong  20  are integral parts, and an outer plastic over-coating  28  that substantially encases the inner core  26 .  
         [0025]     Referring to  FIGS. 6   a - g  according to one embodiment, the resilient prong  20  may be a leaf spring  30  that is inserted into an open slot  32  in the mounting portion  16  of the handle  4  and secured. Preferably, the open slot  32  is configured as a narrow channel that terminates in a substantially circular opening  34 . It is preferred that the “diameter” of the substantially circular opening  34  is smaller than the diameter of the cylindrical portion  36  of the leaf spring  30 .  
         [0026]     Once inserted in the handle  4 , the leaf spring  30  may be staked or tacked in place. It is preferred that the leaf spring  30  is secured to the handle  4  using at least a pair of staking pins  38 , one on each side of the handle  4  as shown in  FIG. 6   e.  The staking pins  38  make contact with the handle  4  at a series of points along the slot  32  containing the leaf spring  30 . Preferably, there is a plurality of pairs of notches or cut-outs  40  along the length of the leaf spring  30 . The notches or cutouts  40  provide room for material that is displaced or deposited over the leaf spring  30  during the fastening process. It is preferred that when the staking pins  38  make contact with the handle  4 , the staking pins  38  displace material into the cut-outs  40  of the leaf spring  30  while at the same time the pins  38  locally deform the handle  4  at these same locations by creating a shallow cavity. In this way, the material displaced by the pins  38  fixes the leaf spring  30  laterally in place. The ends of the staking pins  38  (i.e. the surfaces making contact with the handle) may be either cylindrical or tapered.  
         [0027]      FIGS. 6   a - f  illustrate the embodiment of the staking procedure where the leaf spring  30  is secured to the handle  4  using cylindrical staking pins  38  as shown in  FIG. 6   d.  As shown in  FIG. 6   e,  after the leaf spring  30  is installed into the slot  32 , at least two staking pins  38  are moved simultaneously in the direction indicated by the arrows. Generally, there is one staking pin  38  on each side of the handle. After the staking pins  38  make contact with the handle  4 , the pins  38  displace material into the cutouts  36  in the leaf spring  30 , thereby fixing the position of the leaf spring  30  laterally.  
         [0028]      FIGS. 7   a - c  show the embodiment wherein the leaf spring  30  is secured to the handle  4  using tapered staking pins. The enlarged section depicted in  FIG. 7   c  shows the details of the handle  4  in the area where the leaf spring has been staked in place. The cut outs  40  in the leaf spring  30  provide room for material to flow during the staking operation.  
         [0029]      FIGS. 6   f  and  6   g  show the finished product of the staking process using cylindrical pins. It should be understood that each staking pin  38  has simultaneously displaced material at both upper and lower edges of the cavity and on the left and right sides of the handle surface. If the staking pins  38  are tapered, then depositing sufficient material to laterally secure the leaf spring is at least a two step process. Specifically, a tapered pin  38  must displace material on one edge of the cavity and then displace material on the other edge. Preferably, the pair of tapered staking pins  38  will displace material first at the upper edge of the cavity and then at the lower edge. One advantage to using the tapered staking pins  38  is that the axial force required to accomplish the staking is much lower than the force used when using cylindrical pins  38 .  
         [0030]     It should be understood that the method of fastening the leaf spring  30  to the handle  4  is not limited to staking as described above. Other fastening methods, such as adhesives, soldering, laser welding and EB (electron beam) welding may be used to secure the resilient prong to the handle without departing from the spirit or scope of the invention. In another embodiment, a spring made out of a round wire can be pressed and secured into a round receiving channel that runs parallel with the longitudinal axis of the handle. Preferably, the receiving channel is created by drilling.  
         [0031]     In the embodiment shown in  FIGS. 4 and 5 , the handle  4  is a two-piece component having an inner core  26  and an outer plastic over-coating  28 . Preferably, the inner core  26  is manufactured of stainless steel that is stamped in a configuration that is “near net shape.” In other words, the stamped inner core preferably incorporates all of the features, i.e. the notch(es), the rigid prong  18  as well as the resilient prong  20 , as one piece. The handle  4  is completed via the application of a plastic over-coating  28 . Preferably, the plastic over-coating  28  is molded over the inner core  26 . Alternatively, the inner core  26  is inserted into a pre-made, tight-fitting, plastic sleeve. It should be understood that at least the two prongs  18  and  20  are not encased by the plastic over-coating  28  but rather the prongs  18  and  20  extend from the plastic over-coating  28  to form the mounting portion  16  of the handle.  
         [0032]     Referring to  FIG. 3  and  FIGS. 8   a - d,  the blade assembly  10  includes a blade carrier  42  to which the blade  12  is attached. In one embodiment the blade  12  is permanently fastened to the blade carrier  42  and may be of any shape or size. The protective sleeve  14  may be transparent and include an integral fulcrumed lever  44  adjacent one of its ends mounted on a pair of spaced resilient legs  46 . The lever  44  has a depending tooth  48  at one end and a finger button  50  at the other end whereby depressing the finger button  50  raises the depending tooth  48 . The protective sleeve is open at both its ends. The protective sleeve  14  is mounted on the blade assembly  42 , and, in the covered position in which it completely covers the blade  12  as shown in  FIG. 3 , the depending tooth  48  releasably engages a notch  52  on the top edge of the blade carrier  42 .  
         [0033]     The blade carrier  42  also features a breakaway tab  54 . The tab  54  is configured with shoulders  56  to prevent the premature removal of the protective sleeve  14  from the blade assembly  10 , i.e. before the blade assembly  10  is mounted to the handle  4 . Preferably, when the breakaway tab  54  is in place, the configuration of the shoulders  56  of the tab  54  makes it impossible to slide the protective sleeve  14  over the tab  54  and expose the blade  12 . It is also preferred that the breakaway tab  54  forms a first end portion  58  of a mounting window  60  and must be removed in order to assemble the scalpel  2 .  
         [0034]     Initially, the mounting window  60  is an enclosed, channel-type opening with an intermediate portion  62  that extends toward the blade end of the blade carrier and terminates at a second end portion  64 . The intermediate portion  62  of the mounting window  60  begins with a narrowing ramp  66  but then continues with parallel surfaces  67  spaced apart a substantially constant width. The second or inner end portion  64  of the mounting window  60  is delineated by at least one shoulder  68  that sharply increases the width of the window  60  at that point. After the shoulder  68 , the width of the window may gradually decrease as shown.  
         [0035]     To join the blade assembly  10  to the mounting portion  16  of the handle  4 , the breakaway tab  54  is first completely detached from the blade carrier  42  and discarded. Once the tab  54  is removed, the mounting window  60  is no longer enclosed, which permits the insertion of the mounting portion  16  of the handle  4 . In this way, the tab  54  also serves as an “unused” and/or “new blade” indicator. Removing the tab  54  “opens” the mounting window to receive the two prongs  18  and  20  of the handle  4 . The configuration of the mounting window  60  provides a guide for the two prongs  18  and  20  of the handle during insertion/assembly of the handle  4 .  
         [0036]     The configuration of the window  60  and the prongs  18  and  20  also contribute to the audible “click” that ensures the user that the handle  4  is properly engaged with the blade assembly  10 . Specifically, as the prongs  18  and  20  of the handle  4  enter the narrow channel defined by the intermediate portion of the mounting window  60 , the outwardly biased, resilient prong  20  is squeezed closer to the rigid prong  18 . Compressing the resilient prong  20  toward the rigid prong  18  in this manner puts pressure on the leading edge of the rigid prong&#39;s  18 . As soon as rigid prong  18  advances past the shoulder  68  in the blade carrier  42 , a clicking noise is heard as the leading edge snaps into place behind the shoulder  68 . Once mounted to the handle, the locking tooth  22  on the rigid prong  18  is securely retained behind the shoulder  68  at the second end of the mounting window  60 . The pressure exerted by the outwardly biased, resilient prong  20  on the rigid prong  18  ensures the continued engagement of the locking tooth  22  with the shoulder  66  while the scalpel is in use.  
         [0037]     Referring especially to  FIGS. 9   a - e,  the handle  4  has at least one locking notch  70  intermediate of the proximal and distal ends  6  and  8 . The locking notch  70  is engaged by the dependant tooth  48  of the lever  44  on the protective sleeve  14  when the scalpel is in use. The handle  4  may also have a pair of shoulders  71 , directly opposed to each other, that serve as “stop” surfaces that help to retain the protective sleeve  14  in a secure manner while the handle  4  is engaged with the blade assembly  10 .  
         [0038]     In another embodiment as shown in  FIGS. 11 and 12 , the handle  4  may have a pair of locking notches  70  directly opposed to each other, intermediate of the proximal and distal ends  6  and  8 . With the configuration of the channel forming the mounting window being symmetrical, the blade carrier  42  is “orientation insensitive” when mounted to a handle  4  having a pair of opposed locking notches  68 .  
         [0039]     When the scalpel  2  is assembled with the handle  4  inserted into the blade assembly  10  as shown in  FIGS. 9   a  and  9   b,  the locking tooth  22  on the rigid prong  18  is secured behind the shoulder  68  in the mounting window  60  of the blade carrier  42 . At this point, the protective sleeve  14  is movable between two positions, a covered position and a cutting position. In the covered position as shown in  FIG. 9   b,  the depending tooth  48  of the lever  44  on the protective sleeve  14  releasably engages the notch  52  in the blade carrier  42 . While in this position, the protective sleeve  14  entirely covers the blade  12 . In the second position, the cutting position as shown in  FIG. 9   c,  the protective sleeve  14  is moved partially over the distal end  8  of the handle  4  and the depending tooth  48  engages the locking notch  70  in the handle  4 , thereby exposing the blade  12  for use.  
         [0040]     As shown in  FIGS. 10   a  and  10   b,  to move the protective sleeve  14  between the two positions, the user must first press on the finger button  50  of the lever  44  which will raise the depending tooth  48  and disengage it from a respective locking notch  52  or  70 . Once the tooth  48  has been disengaged, the protective sleeve  14  will slide easily over the surface of the handle  4 . In this way, positioning the protective sleeve  14  between the covered position and the cutting position can be accomplished using only one hand as shown.  
         [0041]     Referring to  FIG. 9   d  and  9   e,  to safely dispose of the blade assembly  10  after use, the user first reestablishes the covered position by sliding the protective sleeve  14  over the blade  12  and engaging the dependent tooth  48  with the notch  52  on the blade carrier  42 . Once the blade  12  is covered, the blade assembly  10  can be separated from the handle by bending the blade assembly upwardly as show in  FIG. 9   d  until the locking tooth  22  on the rigid prong  18  of the handle disengages the shoulder  68  of the mounting window  60  in the blade assembly  10 . It is preferred that the blade assembly  10  be bent toward the locking tooth  22 , which will allow the locking tooth  22  to move past the shoulder  66 . Once the locking tooth  22  is completely disengaged from the shoulder  66 , the blade assembly  10  can then be pulled off the handle  4  as shown in  FIG. 9   e  and safely discarded.  
         [0042]     In another embodiment shown in  FIGS. 11 and 12 , the handle  4  may have a marking, such as an arrow  72 , that points in the direction that the blade assembly  10  must be bent to disengage the blade assembly  10  from the handle  4 . Preferably, the arrow  72  will be stamped in the surface of the handle  4 . The arrow  72  may be stamped on one or both sides of the handle and may also include a letter  74  such as “R” for “removal” as shown in  FIG. 10   a.  Alternatively, an arrow shape may be punched or cut out of the handle creating a hole in the handle as shown in  FIG. 10   b.  It should be understood that the arrow (whether stamped or cut out) is visible only when the protective sleeve  14  is covering the blade, i.e. the covered condition.  
         [0043]     In another embodiment as shown in  FIG. 13 , the same retention/engagement system on the blade assembly  10  and protective sleeve  14  as previously described is used, but the mounting portion  16  of the handle  4  is modified. According to this embodiment, the blade assembly  10  may be removed by pushing on a portion of the mounting portion  10  of the handle  4 . It should be understood that this embodiment does not require bending to release the blade assembly  10 . According to this embodiment, the mounting portion  16  of the handle may have at least two extending prongs  76  and  78  that define a narrow channel  80  in-between. At least one of the prongs  76  has the locking tooth  22  at its end. It is preferred that the narrow channel  80  extends between the two prongs  76  and  78  toward the proximal end  6  of the handle and terminates in an enlarged substantially circular opening  82 . Adjacent to the circular opening  82  is the locking notch  70  which has an arcuate bottom  84  as shown. The mounting portion  16  of the handle  4  of this embodiment also includes the pair of opposing shoulders  71  that act as stopping surfaces for the protective sleeve  14  on the blade carrier  42 . The mounting portion  16  of the handle  4  removeably engages the mounting window  60  located on the blade carrier  42  after the removal of a breakaway tab  54  as described above. It is further preferred that the mounting portion  16  of the handle  4  makes an audible “clicking” noise when fully engaged with the blade assembly  42 . Similar to the other embodiments described herein, the handle  4  is completely engaged with the blade assembly  10  when the leading edge of at least one of the prongs  76  or  78  makes an audible “click” as it advances past the shoulder  68  in the mounting window  16  in the blade carrier  42 .  
         [0044]     It is also preferred that the mounting portion  10  of the handle of the embodiment of  FIG. 13  has a serrated or otherwise textured area  86  located opposite of at least one of the prongs  76  or  78 . According to this embodiment, to separate the blade assembly  10  from the handle  4  when the protective sleeve  14  is in the covered position, the user preferably presses on the serrated or textured area  86  to disengage the locking tooth  22  from the shoulder  68 . The serrated or otherwise textured surface area  86  allows the user to compress the prongs  76  and  78  together efficiently by providing a surface with increased traction under wet and/or slippery conditions. The serrated texture  86  also allows the user to locate the area and disengage the blade assembly without having to look down. It should be understood that the area  86  is not limited to having a serrated texture. Alternatively, the texture could be grooves, dots, etc. or combinations thereof. It is preferred that pressing on the serrated area squeezes the prongs  76  and  78  together (similar to a pair of tweezers) which facilitates the disengagement of the locking tooth  22  from the shoulder  68 . Once the locking tooth  22  moves past the shoulder  68 , the blade assembly  10  can be removed from the handle  4  and discarded without any bending of the blade assembly  10 . In other words, the blade assembly  10  may be pulled straight off the handle in a substantially lateral direction.  
         [0045]     Another preferred embodiment employs the same mounting principle but is miniaturized for use with a narrow surgical scalpel for specialized applications as illustrated in  FIG. 11   a - d.  The handle  4   a,  blade assembly  10   a  and protective sleeve  14   a  all contain the same mounting and functioning elements as in the previous embodiments except that the individual components are miniaturized.  
         [0046]      FIG. 15  shows another embodiment of a blade carrier  90  and protective sleeve  92 . The protective sleeve  92  has an open end  94  to receive the blade carrier  90  which has a blade  96  extending from one end thereof. According to this embodiment, the blade carrier  90  is provided with at least one protrusion  98  in the form of a pin extending from the side of the blade carrier  90 . The protective sleeve  92  includes a fulcrumed lever  100  pivotable on the side edge of the sleeve  92  as shown. The lever  100  has a finger portion  102  at its end closest to the open end  94  and a depression or opening  104  at the other end for releasably receiving the protrusion or pin  98  on the blade carrier  90 .  
         [0047]     To mount the protective sleeve  92  on the blade carrier  90 , the blade carrier  90  is inserted into the open end  94  until the protrusion or pin  98  is engaged with the depression or opening  104  in the sleeve  92 . At this point, the protective sleeve is held in a position covering the blade  96 .  
         [0048]     The blade carrier  90  may be provided with two additional pins  106  and  108  axially spaced from each other and spaced from the pin  98  in a direction away from the blade  96  as shown. It is to be understood that a handle (shown by dotted lines and indicated by the reference number  105 ) may be attached to the blade carrier  90  by virtue of openings on the handle  105  through which the pins  106  and  108  extend.  
         [0049]     When it is desired to move the protective sleeve  92  relative to the blade carrier  90 , the finger portion  102  of the fulcrumed lever  100  may be depressed. This causes the depression or opening  104  at the other end of the fulcrumed lever  100  to disengage from the protrusion or pin  98  on the blade carrier  90  and permit the protective sleeve  92  to be moved relative to the blade carrier  90 . When the handle  105  is mounted on the blade carrier  90 , the protective sleeve  92  may be moved toward the handle  105  until the opening or depression  104  engages the pin  106 . In this position, the protective sleeve  92  still covers the blade  96  and maintains the handle  105  in engagement with the blade carrier  90 .  
         [0050]     The third protrusion or pin  108  provides a locking arrangement for the protective sleeve  92  when the sleeve  92  is moved into its rearward position in which the blade  96  is exposed for cutting. In this position, the depression or opening  104  in the lever  100  releasably engages the protrusion or pin  108  holding the protective cover  92  in the cutting position.  
         [0051]     Those familiar with this field of endeavor will appreciate that one or more of advantages of the preferred embodiments include: (1) increased assurance that the blade assembly is properly engaged with the handle; (2) simplified sleeve and handle retention features permit an “orientation insensitive” assembly of the scalpel; and (3) effective prevention against the accidental reuse of a contaminated blade.  
         [0052]     While various modifications have been shown and described, various modifications and substitutions may be made thereto. Accordingly, it is understood that the present embodiments have been described by way of illustration and not limitation.