Abstract:
A method of cutting a continuous hollow tubular member having a fully expanded configuration with an outer diameter D, includes the steps of feeding the continuous hollow tubular member in the fully expanded configuration to a cutting station, cutting the continuous hollow tubular member into a plurality of hollow tubular members, each of which has a first flattened end and expanding the first flattened end of the plurality of hollow tubular members to the fully expanded configuration such that the first end of the plurality of hollow tubular members has an outer diameter D.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to an apparatus for cutting tubular members and, in particular, an apparatus for cutting tubular members as they are continuously produced such as, for example, by an extrusion process. 
       BACKGROUND AND SUMMARY OF THE INVENTION 
       [0002]    Various machines and apparatus for cutting tubular members are known. Examples of these include U.S. Pat. No. 6,736,409 entitled Drinking Straw Prepared From Flattened Polymeric Tubular Conduit, Method of Making Same and Dispenser Therefor; U.S. Pat. No. 7,549,854 entitled Striped Drinking Straw and Method of Making Same, U.S. Pat. No. 4,212,215 entitled Apparatus For Cutting a Tube of Semi-Rigid Material and U.S. Patent Application Publication No. US 2006/0086228 entitled Tube Cutting Process and Device. Devices for packaging or handling cut tubular members are disclosed in U.S. Patent Application Publication No. US 2006/0026930 entitled Dual Head Straw Wrapper and U.S. Pat. No. 3,648,553 entitled Device for Transporting Elongated Work Pieces. 
         [0003]    In one embodiment of the present invention, an apparatus for cutting tubular members includes a support structure, a control system, a cutting station, a guide and an extracting assembly. The cutting station includes a first wheel having at least one cutting member located on the circumference of the first wheel and a second wheel having at least one projection located on the circumference of the second wheel. The extracting assembly has a cylindrical member with a first end and a second end. The cylindrical member also includes a first interior section tapering from the first end toward the second end, a second interior section tapering from the end of the first interior section toward the second end of the cylindrical member, a third interior section extending from the end of the first interior section toward the second end of the tubular member and a pair of grooves extending from the first interior section to the third interior section. The grooves decrease in height and depth from the first interior section to the third interior section. 
         [0004]    In another embodiment of the present invention, an apparatus for cutting tubular members includes a cutting station and an extracting assembly for ejecting the cut segments of the tubular member from the apparatus. The extracting assembly includes at least one groove for expanding a portion of the cut segments. 
         [0005]    In another embodiment of the present invention, an apparatus for cutting tubular members includes a cutting station and an extracting assembly. The cutting station has a first wheel and a second wheel. The first wheel has at least one cutting member located on its circumference. The cutting member has a portion for cutting the tubular member. The second wheel has at least one projection located on its circumference. The first and second wheels are positioned such that the portion for cutting the tubular member and the projection are aligned on opposite sides of the tubular member when it is cut without the portion for cutting the tubular member contacting the projection. 
         [0006]    In another embodiment of the present invention, a method of cutting a tubular member, includes the step of introducing a tubular member into an apparatus having a cutting station, the cutting station having a first wheel having at least one cutting member located on the circumference of the first wheel, the cutting member having a cutting portion and a second wheel having at least one projection located on the circumference of the second wheel. The method further includes the steps of guiding the tubular member between the first and second wheels and rotating the first and second wheels such that the cutting portion is positioned opposite the projection and has a tangential speed substantially equal to the linear speed of the tubular member while cutting the member. 
         [0007]    In another embodiment of the present invention, a method of cutting a continuous hollow tubular member having a fully expanded configuration with an outer diameter D, including the steps of feeding the continuous hollow tubular member in the fully expanded configuration to a cutting station, cutting the continuous hollow tubular member into a plurality of hollow tubular members, each of which has a first flattened end and expanding the first flattened end of the plurality of hollow tubular members to the fully expanded configuration such that the first end of the plurality of hollow tubular members has an outer diameter D. 
         [0008]    In other embodiments, the method further includes cutting the continuous hollow tubular member into a plurality of hollow tubular members having a second flattened end and a section located between the first flattened end and the second flattened end. The section located between the first flattened end and the second flattened end has an outer diameter D. 
         [0009]    In other embodiments, the method includes expanding the second flattened end of the plurality of hollow tubular members to the fully expanded configuration such that the second end of the plurality of hollow tubular members has an outer diameter D. 
         [0010]    In one embodiment, the second flattened end is formed prior to expanding the first flattened end. 
         [0011]    In another embodiment, the step of expanding the first flattened end includes engaging the first flattened end with a groove. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a front elevational view of an apparatus for cutting tubular members according to one embodiment of the present invention. 
           [0013]      FIG. 2  is a top plan view of the apparatus for cutting tubular members shown in  FIG. 1 . 
           [0014]      FIG. 3  is an enlarged perspective view of the cutting station and extracting assembly that are features of the apparatus for cutting tubular members shown in  FIG. 1 . 
           [0015]      FIG. 4  is a perspective view of the extracting assembly shown in  FIG. 3 . 
           [0016]      FIG. 5  is a cross-sectional view of a portion of the extracting assembly taken along line  5 - 5  in  FIG. 4 . 
           [0017]      FIG. 6  is a cross-sectional view taken along line  6 - 6  in  FIG. 4 . 
           [0018]      FIG. 7  is a cross-sectional view taken along line  7 - 7  in  FIG. 4 . 
           [0019]      FIG. 8  is a perspective view of a segment of a tubular member cut by the apparatus for cutting tubular members shown in  FIG. 1  before it has passed through the extracting assembly. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0020]      FIG. 1  is a front elevational view of an apparatus for cutting tubular members (also referred to as a tubing cutter) according to one embodiment of the present invention. Tubing cutter  10  generally includes a support structure  20 , a control system  30 , a guide  40 , a cutting station  50  and an extracting assembly  60 . 
         [0021]    In the embodiment shown, support structure  20  includes a generally box shaped base  21  having a plurality of wheels  22  and a plurality of supports  23 . Supports  23  include threaded sections  23 A which terminate at one end in feet  23 B. Threaded sections  23 A extend through nuts  24  on base  21 . As will be apparent to one of ordinary skill in the art, supports  23  can be advanced upward through nuts  24  to raise feet  23 B, thereby allowing tubing cutter  10  to be moved by rolling it on wheels  22 . When tubing cutter  10  is placed in the desired location, supports  23  are advanced in the opposite direction until feet  23 B engage the ground and adequately stabilize tubing cutter  10 . Base  21  houses certain of the electronic and other components that control the operation of tubing cutter  10  as described below. 
         [0022]    Control system  30  includes a variety of controls (not shown) that are the interface through which the operator controls operation of tubing cutter  10 . For example, control system  30  can include buttons, switches, knobs and other devices for powering the various components of tubing cutter  10  on and off, changing the operating speed and controlling other functions. 
         [0023]    In the embodiment shown, guide  40  includes a funnel  41  having its larger first end  42  positioned farther from cutting station  50  than its smaller second end  43 . Second end  43  attaches to tube  44  which extends through a bracket  45  adjacent cutting station  50 . An end  46  of tube  44  terminates adjacent the components used for cutting the tubular member as shown in  FIG. 3  and as described in greater detail below. 
         [0024]    Cutting station  50  includes a cover  51  (shown as transparent in  FIGS. 1 and 2 ).  FIG. 3  shows cutting station  50  with cover  51  removed. As shown in  FIG. 3 , cutting station  50  includes a first wheel  52  having a plurality of cutting members  53  disposed about the circumference thereof. In the embodiment shown, wheel  52  includes three cutting members  53  (two of which are shown in  FIG. 3 ) spaced equally around the circumference, i.e., 120° apart. In the embodiment shown, cutting member  53  is a substantially flat, straight die similar to those known for use in die cutting boxes and other flat paper products. In one embodiment of the invention, cutting members  53  are placed within recesses (not shown) in wheel  52  sized to accommodate cutting members  53 . Cutting members  53  may be secured to wheel  52  in a number of manners. In one embodiment, cutting members  53  are secured to wheel  52  by magnets placed beneath or adjacent the recesses or otherwise positioned in or near wheel  52 . Cutting station  50  also includes a second wheel  54  that includes a plurality of lobes or projections  55  spaced equally around the circumference of wheel  54 . The cutting station  50  includes the same number of cutting members  53  and projections  55  spaced at the same interval about the circumference of wheels  52  and  54 . The wheels  52  and  54  are secured to shafts  56  by collars  57 . Shafts  56  are coupled to the drive shaft of drive mechanisms  58 . Although various drive mechanisms  58  can be used, one embodiment of the present invention utilizes two servo motors to rotate wheels  52  and  54 . The various components of cutting station  50  are secured to base  20  and supported thereon by support structure  59 . Note that a portion of support structure  59  includes an elongated opening  59 A. Support structure  59  also supports a rotatable handle  59 B. Handle  59 B is mechanically coupled to a slide mechanism (not shown) such that rotating handle  59 B moves wheel  52  vertically. Opening  59 A accommodates movement of wheel  52  and its associated shaft  56 . 
         [0025]    Extracting assembly  60  generally includes a tube  61  and a pair of gripping members  62  driven by drive mechanism  63 . In the embodiment shown, gripping members  62  are horizontally mounted wheels driven by drive members  63 . Drive members  63  can be any of a number of known mechanisms capable of rotating gripping members  62  on shafts  63 A. Tube  61  extends through bracket  64  as shown in  FIG. 3  and includes a first end  61 A and a second end  61 B. As shown in  FIG. 4 , tube  61  includes a plurality of openings  65  into which gripping members  62  extend to engage the cut tubular member as described in greater detail below. Extracting assembly  60  also includes a pair of slide mechanisms  63 B and handles  63 C ( FIG. 4 ). Rotating handles  63 C causes slide mechanisms  63 B to move toward or away from tube  61 , thereby moving gripping members  62  further into or out of openings  65 . Handles  63 C can be provided with a locking mechanism, such as a set screw. 
         [0026]    Referring to  FIGS. 4-7 , tube  61  includes a first interior section  66 A, a second interior section  66 B, a third interior section  66 C, a fourth interior section  66 D and a fifth interior section  66 E. Section  66 A tapers as shown from first end  61 A toward second end  61 B of tube  61 . Second interior section  66 B likewise tapers in the same direction. A pair of grooves  67  are formed in interior sections  66 A,  66 B and  66 C and have a first end  67 A and a second end  67 B. Grooves  67  decrease in height and depth from end  67 A toward end  67 B, eventually terminating in section  66 C. 
         [0027]    In use, tubing cutter  10  is utilized to cut a tubular member  70  as it is continuously fed into the cutting station  50 . In particular, tubing cutter  10  can be used to cut a continuously extruded tubular member in to sections to produce various items, such as drinking straws. In operation, the tubular member  70  is fed into end  42  of funnel  41 , guided through tube  44  and exits end  46  adjacent wheels  52  and  54  as shown in  FIG. 3 . Control system  30  is utilized to rotate wheels  52  and  54  such that when cutting member  53  engages tubular member  70  to cut it, projections  55  are positioned beneath cutting members  53 . The cutting portion of cutting member  53  extends through tubular member  70  sufficiently to cut it without contacting projection  55 . The rotation of wheels  52  and  54  are controlled such that the tangential speed of the cutting portion of cutting members  53  is the same as the linear velocity of the tubular member  70  being cut when the cut is made. The length of the cut section of tubular member  70  can be varied in a number of ways. For example, utilizing more than three cutting members  53  and projections  55  would result in shorter cut segments having a shorter length. In an alternative embodiment, wheels  52  and  54  do not rotate at a constant speed. Rather, they could be stopped between cuts and then rotated to produce different length cut tubular members. Alternatively, their speeds could be accelerated or decelerated between cuts and accelerated or decelerated such that the speed of cutting member  53  matches the speed of tubular member  70  at the desired time to produce a cut segment of desired length. 
         [0028]      FIG. 8  is a perspective view of a cut segment  70 A of tubular member  70  before it has passed through extracting assembly  60 . As shown in  FIG. 3 , when certain materials are cut, the cut ends  71  and  72  can be flattened during the cutting process. After the cut is made, end  71  enters end  61 A of tube  60 . The tapered configuration of the interior sections of tube  61  guide end  71  such that it engages grooves  67  at ends  67 A, which is sized and configured to be wider and higher than end  71 . As end  71  rides in grooves  67 , it is forced open by the tapered configuration of the decreasing depth of grooves  67 . Thus, the end  71  is open and substantially circular when the cut segment  70 A exits tube  61  at end  61 B. Note grooves  67  also open trailing end  72  of the cut segment  70 A in a similar fashion. Depending on the material from which tubular member  70  is made, the speeds at which the cut segments  70  travel through tube  61  and the number of cut segments processed, grooves  67  can eventually wear and no longer serve their intended purpose. Accordingly, it may be desirable to make tube  61  from a relatively hard, wear resistant material, such as 440C stainless steel. Other materials can also be used. Alternatively, softer materials can be used but tube  61  may need to be replaced more frequently. 
         [0029]    As end  71  reaches opening  65 , gripping members  62  engage cut segment  70 A and eject it from end  61 B. Note that end  61 B includes a plurality of openings  61 C. If desired, a guide tube can be inserted in to interior section  66 E and secured in place by inserting bolts or other fasteners through openings  61 C. The guide tube can be used to further direct the path of travel of cut segments  70 A. 
         [0030]    Although the present invention has been shown and described in detail, the same is for purposes of illustration only and is not a limitation on the invention. Numerous modifications to the invention can be made. For example, the locations of wheels  52  and  54  can be reversed. Handle  59 B could be replaced with a motor or other automated means for moving wheel  52 . Wheel  52  could be stationary and wheel  54  moveable, or both could be moveable. The length and inner configuration of tube  61  can also be changed based on the product being cut. Various guide mechanisms other than funnel  41  and tube  44  can also be used. It is also not necessary that tubing cutter  10  be movable. Rather, cutting station  50  and extracting assembly  60  can be secured to a stationary structure.