Abstract:
A method and apparatus for continuously cleaning a yarn moving through the device. A first secouring body has a yarn entrance and a yarn exit connecting by a centeral cavity. Pressurized fluid is introduced through the yarn while the yarn is positioned within and moving through the central cavity.

Description:
FIELD OF THE INVENTION 
     This invention relates to a device for continuously cleaning yarn and more specifically, for removing lubricants and contaminants during the processing of fibers used to make surgical sutures. 
     BACKGROUND OF THE INVENTION 
     The removal of processing lubricants and associated contaminants is a significant aspect in the processing of surgical ligatures such as braided sutures, woven tapes and yarns. The difficulty in cleaning the surgical ligatures stems from the fact that the contaminants and lubricants can be trapped between the individual filaments of the yarn bundle in these surgical ligatures. In order to clean the ligature, a cleaning agent or solvent must permeate the crevices between the filaments of the yarn bundle. Typically, surgical ligatures have been cleaned by various batch methods, where the ligature is immersed in a bath for a predetermined amount of time sufficient to remove lubricants and contaminants from the fibers. 
     The present invention provides a solution to the above-mentioned problem by providing a device that continuously cleans yarn fibers, and which does not require any stoppage or interruption in the yarn manufacturing process in order to clean such ligatures. 
     Venturi devices, such as that disclosed in U.S. Pat. Nos. 3,097,412; 3,462,813; 3,545,057; 3,577,614; 3,863,309; 3,881,231; 3,969,799; 3,979,805; 4,041,583; 4,096,612; 4,104,770; 4,157,605; 4,189,812 and 4,290,177; all incorporated herein by reference, have been used for texturizing yarns, but not for cleaning lubricants and contaminants from yarns. 
     It is therefore an object of the present invention to provide a device for continuously cleaning a ligature. 
     Another object of the present invention is to provide a device for removing lubricants and contaminants during the processing of surgical ligatures. 
     Still another object of the present invention is to provide a method for continuously cleaning surgical ligatures moving through a device. 
     A further object of the invention is to provide a method for removing lubricants and contaminants during the processing of surgical ligatures. 
     These and other objects and advantages of the invention will become more fully apparent from the description and claims, which follow or may be learned by the practice of the invention. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a method and apparatus for continuously cleaning a surgical ligature moving through the device. A first scouring body has a yarn entrance and a yarn exit connected by a central cavity. Moving fluid is introduced through the surgical ligature while the surgical ligature is positioned within and moving through the central cavity. 
     In a particularly preferred embodiment, a device in accordance with the present invention further comprises an inlet in fluid communication with the central cavity of the scouring body, and a venturi situated within the central cavity. The venturi is preferably positioned at the exit. The venturi devices listed in the background, and incorporated by reference, would all be used in the present invention. In one preferred embodiment, a needle is slidably mounted into the central cavity through the entrance of the venturi. The needle includes a passage there through for introducing ligature through the central cavity and, at least one flange and a cap. The flange of the needle has at least one opening to allow movement of the fluid from the solvent inlet to the central cavity. This preferred device further comprises at least one cover for holding the needle securely within the central cavity of the scouring body and at least one adjustment nut for adjusting movement of the needle within the central cavity. The cover is in direct contact with the adjustment nut. The device also preferably includes ceramic eyelets situated adjacent to the entrance of the scouring body. In an alternative preferred embodiment, the cleaning device has a baffle for guiding the ligature. The baffle is slidably mounted on a bracket affixed to the scouring body at the exit. A turning pin may also be provided for holding the baffle in the bracket. The entrance and exit are preferably located on opposing sides of the scouring body. 
     A ligature cleaning system in accordance with the present invention preferably includes two of the scouring bodies described above. Like the first scouring body, the second scouring body has a entrance and exit connected by a central cavity and a means for introducing fluid through the ligature while the ligature is positioned within and moving through the central cavity of the second scouring body. The first and second scouring bodies are arranged in tandem. Each of the first and second scouring bodies has an axis defined by its entrance and exit. The axis of the first and second scouring bodies can be co-axially aligned along a common axis when the system is in its thread-up state. The axes of the first and second scouring bodies are then aligned at a non-zero angle in order to bring the system into a scouring state. The angle between the axes of the first and second scouring bodies is from about 45° to about 90°. When the system is used to clean thinner ligature, the non-zero angle varies from about 60° to about 75°. Separation of the liquid stream containing contaminants and lubricants from the ligature fiber occurs when the ligature fiber is guided away from the exit of a scouring body at an angle. A plurality of scouring bodies can be aligned to continuously clean surgical ligatures. 
     The ligature cleaning system can also include a housing for encasing a scouring body and a rotatable mounting device for attaching the scouring body within the housing. The housing comprises eyelets for introducing and removing ligature. The housing can also include a fume hood for removing vapors emitted by the cleaning fluid. 
     The device of the present invention can also comprise a fluid reservoir and a connecting means for transporting solvent from the reservoir to a scouring body. The preferred cleaning fluid is ethyl acetate and the ligature fiber is a suture strand. 
     The present invention also relates to a method of continuously cleaning a ligature moving through a device. The method comprises the following steps: (a) guiding ligature through a scouring body having a entrance and exit connected by a central cavity, and (b) introducing fluid through ligature positioned within and moving through the central cavity. Before employing step (a), a needle can be slidably mounted into the central cavity and the ligature can be introduced into the central cavity using a needle. After the needle is mounted, the movement of the needle can be adjusted with an adjustment nut. Before employing step (b), the ligature can be moved through a second scouring body having entrance and exit connected by a central cavity, and then the first and second scouring bodies can be aligned at a non-zero angle. The angle between the first and second bodies can vary from about 45° to about 90°. 
     The method of the present invention can also include the following steps of: (a) axially aligning at least two scouring bodies during a thread-up state; (b) guiding ligature through the central cavity of the scouring bodies utilizing an axially slidable needle; (c) rotatably adjusting the scouring bodies creating a non-zero angle; and (d) introducing fluid through the central cavities of the scouring bodies while moving the ligature through the central cavities of the scouring bodies, thereby cleaning the ligature of contaminants and undesired lubricants during a scouring state. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In order that the manner in which the above-recited and other advantages and objects of the invention are obtained and can be appreciated, a more particular description of the invention briefly described above will be rendered by reference to a specific embodiment thereof which is illustrated in the appended drawings. Understanding that these drawings depict only a typical embodiment of the invention and are not therefore to be considered limited of its scope, the invention and the presently understood best mode thereof will be described and explained with additional specificity and detail through the use of the accompanying drawings. 
     FIG. 1 is a cross-sectional view of a scouring body for continuously cleaning a surgical ligature as it travels through the central cavity of the scouring body, in accordance with a preferred embodiment of the present invention. 
     FIG. 2 is a diagram showing the operation of an overall system for cleaning surgical ligature, in accordance with a preferred embodiment of the present 
     FIG.  3   a  is a diagram showing two scouring bodies in a thread-up position. 
     FIGS.  3   b  and  c  are diagrams showing scouring bodies in different scouring positions, in accordance with alternative preferred embodiments of the present invention. 
     FIG. 4 is a cross-sectional view showing a baffle fixed with relation to the exit of a scouring body, in accordance with another preferred embodiment of the present invention. 
     FIG. 5 is a cross-sectional view showing a baffle free to seek a force balance position with respect to the exit of a scouring body, in accordance with another preferred embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to the drawings wherein like reference numerals designate identical or corresponding parts throughout the several views, and more particularly, to FIGS. 1,  4  and  5  wherein a ligature cleaning device in accordance with the present invention, generally designated  1 , comprises a scouring body  10  having an entrance  12  and an exit  13  connected by a central cavity  15 . The device  1  further comprises an inlet  16  in fluid communication with the central cavity  15 , and a venturi  18  situated within the central cavity  15  near the exit  13 . The cleaning device  1  also has a needle  20  slidably mounted into the central cavity  15  through the entrance  12 ; the needle  20  has a passage  22  therethrough for introducing ligature  5  through the central cavity  15 . The needle  20  has at least one flange  24  and a cap  25 . The flange  24  of the needle  20  has at least one opening  26  for allowing movement of fluid  7  from the inlet  16  to the central cavity  15 . The device further comprises at least one cover  27  for holding the needle  20  securely within the central cavity  15 , and at least one adjustment nut  28  for adjusting the position of the needle  20  within the central cavity  15 . The cover  27  is in direct contact with the adjustment nut  28 . The device can also have ceramic eyelets  29  for protecting the ligature  5 ; the eyelets  29  are situated adjacent to the entrance  12  of the scouring body  10 . 
     FIG. 2 shows an overall system  100  for cleaning a surgical ligature. System  100  includes a second scouring body  30  which is substantially the same as scouring body  10 , and thus includes an entrance  32  and an exit  33  connected by a central cavity. The first and second scouring bodies,  10  and  30  respectively, rotatably mounted within and are encased by the housing  40 . The housing  40  comprises eyelets  42  and  43  for introducing and removing ligature  5  from housing  40 . The housing  40  also has a fume hood  45  for removal of toxic gases emitted by the fluid  7 . The system  100  also has a fluid reservoir  46  and a connecting means  47  for transporting fluid  7  from the reservoir  46  to the scouring bodies,  10  and  30 , respectively. 
     FIGS.  3   a, b  and  c  show system  100  in a thread-up position and scouring positions. The thread-up position is used to thread ligature  5  through device  100  prior to the initiation of cleaning or scouring operations. In the thread-up position (FIG.  3   a ), the yarn entrances and exits of the first and second scouring bodies,  10  and  30  respectively, are rotated until they are aligned along a common axis A within a housing  40 . The housing  40  has eyelet entrance  42  for introducing and removing ligature  5 . During the threadup operation, the ligature  5  is guided from the eyelet entrance  42  of the housing  40  to the entrance  12  of the first scouring body  10  through its central cavity  15  and out its exit  13 . The yarn is then introduced to the entrance  32  of the second scouring body  30  through its central cavity  35  and out its exit  33  and through the eyelets exit  43  of the housing  40 . 
     FIGS.  3   b  and  c  show the scouring bodies,  10  and  30  respectively, in different scouring positions. After the thread-up operation is complete, scouring bodies  10  and  30  are then preferably rotated until they are aligned in one of the scouring positions shown in FIGS.  3   b  and  3   c . Each of the first and second scouring bodies,  10  and  30 , has an axis  50  or  51 , defined by a line passing through its entrance,  12  or  32 , and its exit,  13  or  33 . In the scouring positions shown, the axes of the first and second scouring bodies,  50  and  51 , are aligned at a non-zero angle. The angle (a) between the axis of the first and second bodies is from about 45° to about 90°, and may be varied depending on the thickness of the yarn suture. For example, FIG.  3   b  shows a scouring used for cleaning thicker (i.e., 3 to 0 braided suture) ligature, and FIG.  3   c  shows a scouring position used for thinner (i.e., 1/0 to 8/0 braided suture) ligature. The scouring position in FIG. 3 is preferred for thinner ligatures because the angle of ligature  5  relative to axes  51  and  52  is smaller, thus creating less tension on the ligature and minimizing the likelihood of breaking or damaging the ligature. 
     In accordance with an alternative preferred embodiment, FIG. 4 shows a cross-section of the device  1  with a baffle  60  installed adjacent to the venturi  18  and the exit  13  in accordance with the teachings of Breen, U.S. Pat. No. 2,852,906 incorporated herein by reference. The baffle  60  is slidably mounted in bracket  62 , which in turn is affixed to the scouring body  10  at the exit  13 . A turning pin  63  holds the baffle  60  in place in the bracket  62  and when released, the baffle  60  can be moved from the exit end of the device  1  for ease of thread-up. 
     In accordance with an alternative preferred embodiment, FIG. 5 shows the cleaning device  1  with a baffle  70  movable about a hinge pin  72  according to the teachings of Kozlowski, U.S. Pat. No. 3,835,510, incorporated herein by reference. Hinge pin  70  is mounted off-center of cylinder  74 , which is rotatable in bracket  76 , which is attached to the scouring body  10 . A knob (not shown) is used to rotate cylinder  74 , thus providing an eccentric motion for varying the position of the baffle  70  for optimum operating conditions. A layer of wear-resistant ceramic material  77  may be attached to the surface of baffle  70  facing the outlet end of the device  1 . 
     To thread-up the device  1 , ligature  5  is presented to the entrance  12  of the device  1  with the assistance of the needle  20 . The cover  27  is moved inwardly away from the head of the adjustment nut  28 , from a preset operating position to a string-up position so that an aspirating effect draws the ligature  5  through the entrance  12  and out through the passage  22 . When the ligature  5  emerges from the venturi  18 , the cover  27  is allowed to return to its preset operating position against the adjustment nut  28  under the force of pressure against the needle  20  in the reduced region of the yarn needle. In this manner, pressure in communication with piston and cylinder arrangement of the needle  20  and scouring body  10  in the central cavity  15  is relied on to return the needle  10  back to the present operating position after string-up. The ligature is then guided through the venturi and out of the device  1  at an angle. Once thread-up is complete, pressurized fluid  7  is then introduced from the inlet  16  to the central cavity  15 , thus cleaning the ligature  5  positioned within and moving through the central cavity  15  of the scouring body  10 . 
     For the purpose of this invention, a surgical ligature includes yarns, braided constructs and woven or knitted tapes. The fluid used to clean the ligatures should be an appropriate liquid to remove the desired contaminants and/or clean the ligature. Generally the fluids will be cleaning solutions (detergents, surfactants, emulsifiers, wetting agents and combinations thereof) or solvents (i.e., ethyl acetate, acetone, toluene, trichloroethane, water and/or steam). If absorbable sutures are being cleaned aqueous cleaning solutions should be avoided. The fluids used to clean the ligatures may be applied at elevated temperature to facilitate cleaning. 
     Additionally, the present invention can be combined with conventional ligature cleaning techniques such as scouring baths (which have moving fluids or agitation such as mechanical, sonic or ultrasonic) and/or rinsing procedures. The present invention may be combined with other conventional post cleaning steps such as drying, heat stretching, coating, sterilization and packaging. 
     Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore understood that within the scope of the appended claims appended hereto, the invention may be practiced otherwise than as specifically disclosed herein.