Patent Document

CROSS-REFERENCE TO RELATED APPLICATIONS 
     This Application is a Division of application Ser. No. 13/787,435 filed on Mar. 6, 2013. Application Ser. No. 13/787,435 claims the benefit of U.S. Provisional Application 61/607,219 filed on Mar. 6, 2012, the contents of which are incorporated herein in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention is directed to a bone and tissue removal device, such as is known as a rongeur type instrument (French for rodent or gnawer) which is used for opening a window in a bone for any number of purposes not limited to neurosurgery (skull) or orthopedic (musculoskeletal) surgery, as well as oral maxillofacial, hand or other surgical procedures. The removal device according to the present invention improves upon prior art “rongeur” type instruments and provides a manual pliers type variant with alligator type gnawing teeth incorporated into a first jaw which aligns with an opposing and depth defining collection chamber exhibiting an upper razor edge associated with a second jaw, an ejection mechanism including an elongated and pivotally actuated scoop which is operable to eject previously collected debris from within the collection chamber of the second jaw. 
     BACKGROUND OF THE INVENTION 
     Rongeur surgical cutting instruments are known in the art for removing sections of bone or cartilage. Notable examples of these include the surgical rongeurs depicted in each of U.S. Pat. No. 5,653,73 and U.S. Pat. No. 6,142,997 and which disclose two shaft members capable of reciprocating motion relative to each other wherein one shaft member terminates in a foot plate and the other shaft member includes a combined cutting element and disposable storage chamber. The rongeur may be manually activated or solenoid powered by a battery. 
     A further example of an adjustable powered rongeur is depicted in US 2010/0179557 to Husted and which teaches an adaptable deburring bit and independent nerve sensors that facilitate positioning of the instrument to a proximate surgery site. The medical instrument has a hand piece on a proximal end of a shaft and a hollow tip portion on a distal end of the shaft. The hand piece includes a handgrip and a squeezable trigger portion, whereby the trigger portion is independently compressible of the handgrip. The trigger portion controls a rotatable surgical tool bit which is housed in the tip portion and powered by a connecting drive system. A safety apparatus is provided on the grip portion, capable of locking the instrument and a monitoring system disposed on the tip portion, in order to identify proximity of nerve endings. 
     SUMMARY OF THE INVENTION 
     The present invention discloses a rongeur type bone and cartilage removal device incorporating first and second pivotally secured handles, the first handle terminating at a forward end in a first jaw exhibiting a plurality of extending teeth, with second handle terminating in a second jaw opposing the first jaw and exhibiting a continuous blade edge against which the teeth seats during pivotal motion of the jaws in order to successively excise increments of bone for evacuation through the passageway and into the collection chamber. The first and second jaws each exhibit an elongated and depth defining shape, with the first jaw being an upper and downwardly open jaw and the second jaw being a lower and upwardly open jaw. 
     A pivotally actuated scoop can be associated with the second lower jaw for removing previously stored debris. A finger projection extends from a pivotal washer shaped portion in a direction opposite a forward projecting direction of the scoop, a tab extending from the finger and seating in a first position within an underside of the second handle in engagement with a forward end location of an embedded stem. 
     Yet additional features include a coil spring seating within the second handle and biasing against the finger. A push button being incorporated into a remote location of the second handle and, upon being depressed, permitting a second coil spring embedded in a rear location of the second handle to cause a linear retraction of the embedded stem resulting in release of the tab and subsequent upward pivoting of the scoop. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Reference will now be made to the attached drawings, when read in combination with the following detailed description, wherein like reference numerals refer to like parts throughout the several views, and in which: 
         FIG. 1  is a side view of a manual pliers type variant is also disclosed with alligator type gnawing teeth incorporated into a first jaw which aligns with an opposing and depth defining collection chamber exhibiting an upper razor edge associated with a second jaw; 
         FIG. 2  is a rotated perspective of the manual pliers type variant of  FIG. 1  and which better depicts the pivotally opposing and incising nature of the upper alligator teeth and opposing elongated collection chamber with upper facing and continuous razor edge; 
         FIG. 3  is a rotated rear facing view of the pliers type variant of  FIG. 1  and better illustrating an external depiction of a trigger ejection mechanism for removing debris from the collection chamber via a pivotally actuated scoop; and 
         FIG. 4  is a similar view to that shown in  FIG. 3  and illustrating the selected trigger mechanism incorporating handle and integrally extending jaw in lengthwise cutaway in order to better depict inner working mechanism operable upon depressing the handle located button for pivotally actuating the coaxially supported and elongated scoop from within the collection chamber interior of the jaw for ejecting previously collected debris from. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring further to  FIGS. 1-4 , a series of side, perspective and cutaway views are generally shown at  10  of a manual pliers type variant of tissue and bone graft removal device according to the present invention. The pliers type rongeur device incises or removes a small volume of bone or the like with each iteration or bite and includes a first handle  12  and a second handle  14 . 
     Each of the handles  12  and  14  are contoured along their rear extending grasping portions and each includes a circular overlapping and pivotally joined portions  16  (best shown in  FIGS. 2-3 ) and  18  (shown in each of  FIGS. 1-3 ), respectively. The first handle  12  terminates forwardly of its pivotally overlapping portion  16  in an integrally formed upper jaw  20  exhibiting an elongated depth defining and downwardly open profile integrating a continuous plurality of alligator type gnawing teeth  22 . 
     The second handle  14  likewise terminates forwardly of its pivotally overlapping portion  18  in a like integrally formed and upwardly open facing and depth defining lower jaw  24  which exhibits a substantially identically configured contour as the upper jaw  20 . The lower jaw  24  exhibits an upper continuous blade edge  26  and which matches the profile of the downwardly facing teeth  22  so that that, upon positioning the jaws  20  and  24  on opposite sides of a section of bone to be removed, inward opposing compression applied to the handles results in the jaws pivoting together and the teeth  22  to abut the opposite continuous razor or blade edge  26  concurrent with a volume of bone or like debris being excised or “bitten off” and deposited within an interior chamber  28  (see  FIGS. 2 and 4 ) defined in the lower jaw  24 . 
     With reference to  FIGS. 2-4 , additionally illustrated is a trigger ejection mechanism for assisting in easy ejection of previously deposited bone and like debris from within the lower jaw collection chamber  28 . The ejection mechanism includes an elongated scoop  30  extending from a pivotally supported washer shaped portion  32  (see as best shown in  FIG. 4  and in which the scoop  30  is connected to the washer portion  32  via a stepped location  34 ) which is mounted upon a coaxial pin or hub  36  extending through an aligning aperture associated with at least one of the overlapping portions  16  or (as shown in  FIG. 2 )  18  so that the elongated scoop  30  (exhibiting an arcuate profile in cross section) pivots from a first recessed seating location ( FIG. 2 ) in which the scoop seats within a recessed matching base inner profile  38  ( FIG. 4 ) to a second upwardly pivoted location ( FIGS. 3 and 4 ) in which the scoop  30  upwardly ejects the debris from within the chamber. 
     As again best shown in  FIG. 4 , additional features incorporated into the trigger ejection mechanism include an integral rearwardly projecting finger  40  extending from the coaxially supported washer shaped  32 . A coil spring  42  seats within an inner elongated and recessed profile, at  44 , defined in depth extending fashion from an underside accessible location of the second handle  14  proximate the overlapping portions  16 / 18  of the jaws  12 / 14 , with a base mounting location  46  of the spring  42  engaging the finger projection  40  at an offset location from its pivot fulcrum provided by the coaxial mounting hub  36 . 
     A tab  48  extends upwardly from a rearward proximate end of the finger  40  rearwardly of the coil spring  42  and seats within a mating recess profile  50  defined in a rearwardly spaced and downwardly communicating location of the upper handle  14  which is proximate to the inner seating location of the spring  42  as again shown in  FIG. 4 . A push button  52  is spring biased at a mounted at a rearward location of the upper handle  14  and exhibits an inner slot  54  through which is received a rearward extending end of an elongated stem  56  embedded within an elongated recess defined in the handle  14 , with a second coil spring  58  extending linearly on a rear side of the button  52  in embedded fashion within said second handle. 
     According to this configuration, and upon the button  52  being inwardly depressed in the direction of arrow  60 , a clearance is established between the internally configured slot  54  and the stem  56 . At this point, a pulling or withdrawing force exerted by the coil spring  58  on the elongated stem  56 , see arrow  62 , with an opposite forward end  64  of the stem  56  being retracted from an engaging location with a downwardly angled abutment location of the tab  48 . 
     It is noted that the spring  58  in the position of  FIG. 4  is tensioned such that its bias is to pull the stem  56  along the direction of arrow  62 . Releasing of the tab  48  from the forward edge abutment  64  of the stem  56  results in the coil spring  42  exerting a downward pivoting force causing the washer  32  to rotate about the hub  36  with the scoop  30  being caused to pivot upwardly as shown in  FIG. 4 . The construction of the button  52  is further such that it can be reset in order to reverse engage the stem  64  (in a direction opposite to arrow  62 ) to the tab  48 . 
     Having described my invention, other and additional preferred embodiments will become apparent to those skilled in the art to which it pertains, and without deviating from the scope of the appended claims.

Technology Category: 1