Abstract:
Embodiments of a clamp for compressing a flexible tube are disclosed herein. In one such embodiment, the clamp includes a first member, a second member moveably coupled to the first member to move into and out of a clamping position to apply a compressive force to the tube, a locking member to hold the first and second members in the clamping position, a third member moveably retained between a pair of sidewalls of one of the first member and the second member, and a fourth member moveably coupled to one of the first member and the second member and engageable with the third member to apply an additional compressive force to the tube.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to U.S. Provisional Patent Application No. 61/159,994, filed Mar. 13, 2009, U.S. Provisional Patent Application No. 61/176,712, filed May 8, 2009, and U.S. Provisional Patent Application No. 61/265,502, filed Dec. 1, 2009, all of which are hereby incorporated by reference in their entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The invention relates to a conduit clamp for closing a pathway defined by a conduit, and more particularly for closing a pathway defined by medical tubing. 
       BACKGROUND 
       [0003]    Tubing, often made of a flexible material such as plastic or rubber, is widely used in the medical, pharmaceutical, biopharmaceutical, food and beverage and other laboratory environments. While the tubing typically serves as a conduit for fluid, occasionally it is useful to close the tubing, thereby stopping the flow of the fluid through the tube. To this end, various devices have been developed to close tubing. Many such devices include a moveable tube closing member having a portion engaged directly by a hand of a user to move the tube closing member into contact with the tubing and to close the tubing. 
       SUMMARY 
       [0004]    Embodiments of a clamp for compressing a flexible tube are disclosed herein. In one such embodiment, the clamp includes a first member and a second member moveably coupled to the first member to move into and out of a clamping position to apply a compressive force to the tube. The clamp also includes a locking member to hold the first and second members in the clamping position and a third member moveably retained between a pair of sidewalls of one of the first member and the second member. Additionally, the clamp includes a fourth member fourth member moveably coupled to one of the first member and the second member and engageable with the third member to apply an additional compressive force to the tube. 
         [0005]    In another such embodiment, the clamp includes a first member having a first end and a second end and a second member with a first end and a second end. The first and second members are moveably coupled at their first ends to move into and out of a clamping position to apply a compressive force to the tube. The clamp also includes a locking member pivotally coupled to the second end of at least one of the first member and second member. The locking member is adapted to hold the first and second members in the clamping position. Additionally, the clamp includes a lever member moveably coupled to one of the first member and the second member to apply an additional compressive force to the tube. 
         [0006]    These and other embodiments are described in additional detail hereinafter. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and wherein: 
           [0008]      FIG. 1  is a side elevation view of an example of a tube; 
           [0009]      FIG. 2  is a side elevation view of an example of a tube clamp partially closing the tube of  FIG. 1 ; 
           [0010]      FIG. 3  is a side elevation view of the clamp of  FIG. 2  fully closing the tube; 
           [0011]      FIG. 4  is a cross-section of the clamp taken along line B-B of  FIG. 2  without the tube; 
           [0012]      FIG. 5  is a cross-section of the clamp taken along line A-A of  FIG. 3  without the tube; 
           [0013]      FIG. 6  is an end elevation view of a first link of the clamp of  FIG. 2 ; 
           [0014]      FIG. 7  is a top plan view of the first link of  FIG. 6 ; 
           [0015]      FIG. 8  is an end elevation view of a second link of the clamp of  FIG. 2 ; 
           [0016]      FIG. 9  is a side elevation view of the second link of  FIG. 8 ; 
           [0017]      FIG. 10  is elevation view of the second link of  FIG. 8  taken from an opposing end of the second link from the view of  FIG. 8 ; 
           [0018]      FIG. 11  is a top plan view of the second link of  FIG. 8 ; 
           [0019]      FIG. 12  is a side elevation view of the clamp of  FIG. 2  having its second link disengaged from its bottom member and its lever in a released position; 
           [0020]      FIG. 13  is a side elevation view of the clamp of  FIG. 12  having its second link engaged with its bottom member and its lever in a partially engaged position; 
           [0021]      FIG. 14  is a side elevation view of the clamp of  FIG. 13  having its lever in a fully engaged position; 
           [0022]      FIG. 15  is an end elevation view of the clamp of  FIG. 14 ; 
           [0023]      FIG. 16  is a top plan view of the clamp of  FIG. 14 ; 
           [0024]      FIG. 17  is an end elevation view of a guillotine of the clamp of  FIG. 2 ; 
           [0025]      FIG. 18  is a perspective view of another example of a tube clamp; 
           [0026]      FIG. 19  is a partial cross sectional view taken along the line C-C shown in  FIG. 18 ; 
           [0027]      FIG. 20  is a partial top plan view of a lever of the tube clamp of  FIG. 18 ; and 
           [0028]      FIG. 21  is a perspective view of another example of a tube clamp and a tube in an unengaged position; 
           [0029]      FIG. 22  is a top plan view of the clamp of  FIG. 21  without the tube; 
           [0030]      FIG. 23  is a perspective view of the clamp of  FIG. 21  in a fully engaged position without the tube; 
           [0031]      FIG. 24  is a side elevation view of the clamp of  FIG. 23 ; 
           [0032]      FIG. 25  is a top plan view of the clamp of  FIG. 23 ; 
           [0033]      FIG. 26  is a cross-section of the clamp taken along line D-D of  FIG. 24 ; 
           [0034]      FIG. 27  is a bottom plan view of the clamp of  FIG. 23 ; 
           [0035]      FIG. 28  is an end elevation view of the clamp of  FIG. 23 ; and 
           [0036]      FIG. 29  is another end elevation view of the clamp of  FIG. 23 . 
       
    
    
     DETAILED DESCRIPTION 
       [0037]    Tubing in the medical and pharmaceutical industries has recently become larger. For example, tubing having a 1.5″ outer diameter with a 0.25″ wall thickness is now commonly used. Such tubing may be difficult to compress an amount sufficient to close the tubing by hand using known devices. Indeed, closing such tubing using known devices can require using a large amount of one&#39;s body weight. 
         [0038]    A tube  12  as shown in  FIG. 1  can define a fluid pathway  11 . The tube  12  can be any type of tubing, such as tubing used in the medical or pharmaceutical industries for selectively controlling the flow of fluid. The tube  12  can also any other type of flexible tubing such as those used in irrigation or a garden hose. The tube  12  can be in communication with a manifold system, a bio-bag, a patient, and/or another object. Additionally, the tube  12  can be resilient such that it automatically re-opens from a closed position when not urged shut. As shown in  FIG. 1 , the tube  12  can have an outer diameter of 1.5″ and an inner diameter of 1.0″, though the tube  12  can have a different outer and/or inner diameter. 
         [0039]    A clamp  10  as shown in  FIGS. 2 and 3  can be used for closing the fluid pathway  11  through the tube  12 . As a general overview of the clamp  10 , the clamp  10  can include a top member  14  and a bottom member  16  as shown in  FIGS. 2 and 3 . A first link  18  can be pivotally coupled to a first end  20  of the top member  14  and a first end  22  of the bottom member  16 . A second link  24  can be pivotally coupled to a second end  26  of the top member  14 , and the second link  24  can be selectively engaged with a second end  28  of the bottom member  16 . 
         [0040]    When the second link  24  is not engaged with the bottom member  16  as shown in  FIG. 2 , the top member  14  can be rotated relative to the bottom member  16 . To engage the clamp  10  with the tube  12 , the top member  14  can be rotated away from the bottom member  16  such that there is a sufficient distance between the top and bottom members  14  and  16  to insert the tube  12  there between. With the top and bottom members  14  and  16  rotated sufficiently apart from one another, the clamp  10  can be moved to position the tube  12  between the top and bottom members  14  and  16 , and then the top member  14  can be rotated toward the bottom member  16  to the position shown in  FIGS. 2 and 3 . 
         [0041]    During rotation of the top member  14  toward the bottom member  16 , the top member  14  can initially contact the tube  12 , at which time the tube  12  is still fully open. When the top member  14  initially contacts the tube  12 , the top member  14  can be angled obliquely relative to the bottom member  16  (i.e., the top member  14  can be angled away from the bottom member  16  relative to the position of the top member in  FIG. 2 ). By further rotating the top member  14  toward the bottom member  16 , the tube  12  can be initially deformed, thereby narrowing but not fully closing the pathway  11 . Due to the geometry and construction of the tube  12 , rotation of the top member  14  toward the bottom member  16  to initially deform the tube  12  can require a relatively small amount of force and can be accomplished by hand without a great deal of effort. For example, the top member  14  can be rotated by hand without applying one&#39;s body weight to a position in which the tube  12  is partially closed as shown in  FIG. 2 . As such, a mechanical advantage can be employed such that the force applied to the tube is a multiple of the force applied by hand to the lever. Therefore, even if a large force is required to close the tubing, the amount of force a user must input to the lever to close the tubing can be low. 
         [0042]    As the top member  14  is rotated further toward the bottom member  16  from the position in which the top member  14  initially contacts the tube  12 , the pathway  11  is narrowed. However, since the tube  12  can exert greater and greater amounts of force in opposition to rotation of the top member  14  toward the bottom member  16  as the tube  12  is narrowed, rotation of the top member  14  toward the bottom member  16  can eventually require a sufficiently large amount of force that continued rotation of the top member  14  toward the bottom member  16  by hand becomes difficult even though the tube  12  is not fully closed. The amount of force can be especially large when the tube  12  is of the oversized variety (e.g., having the 1.5″ outer diameter and 1.0″ inner diameter as shown in  FIG. 1 ). With the clamp  10 , however, the top member  14  need not be rotated until it is sufficiently close to the bottom member  16  to fully close the tube  12 . 
         [0043]    Instead, the top member  14  can be rotated toward the bottom member  16  only until the top member  14  is generally parallel with the bottom member  16  as shown in  FIGS. 2 and 3 , as deforming the tube  12  to allow the top and bottom members  14  and  16  to be parallel can still require a small enough amount of force to be performed by hand. With the top member  14  and bottom member  16  generally parallel, the second link  24  can be engaged with the bottom member  16  as shown in  FIG. 3  to hold the top and bottom members  14  and  16  in the parallel position. 
         [0044]    With the top and bottom members  14  and  16  held parallel to one another, a guillotine  30  can be actuated to fully close the tube  12  as shown in  FIG. 3 . (Note that the use of the word “guillotine” to describe guillotine  30  does not imply that the guillotine  30  cuts through the tube  12 .) The guillotine  30  can be hinged to the top member  14  by a hinge  32  positioned near the second end  26  of the top member  14 , and the top member  14  can include another hinge  33  to which a lever  34  having a cam portion  36  is rotatably coupled. The lever  34  can be actuated by rotating the lever  34  toward the top member  14 , thereby causing the cam portion  36  to engage the guillotine  30  and urge the guillotine  30  downward from the position shown in  FIG. 2  to the position shown in  FIG. 3  to fully close the tube  12 . 
         [0045]    To disengage the clamp  10 , the lever  34  can be rotated away from the top member  14 , thereby disengaging the cam portion  36  from the guillotine  30 . If resilient, the tube  12  can urge the guillotine  30  upward from the closed state shown in  FIG. 3  to the open state shown in  FIG. 1 . The second link  24  can be disengaged from the bottom member  16 , and the top member  14  can be rotated away from the bottom member  16 . 
         [0046]    Now describing the clamp  10  in detail with reference to  FIGS. 4 and 5 , the top member  14  can include a first sidewall  38  and a second sidewall  40 . The sidewalls  38  and  40  can be generally parallel, and the sidewalls  38  and  40  can be spaced apart to define a channel  42  having a width slightly greater than a width of the guillotine  30 . Thus, the guillotine  30  can move upward and downward between the sidewalls  38  and  40 , as can be understood from  FIGS. 4 and 5 . A first lip  44  can extend from the first sidewall  38  toward the second sidewall  40 , while a second slip  46  can extend from the second sidewall  40  toward the first sidewall  38 . The lips  44  and  46  can be spaced apart by a distance less than the width of the guillotine  30 . Thus, the lips  44  and  46  can limit movement of the guillotine  30  in a direction downward toward the bottom member  16  as shown in  FIG. 5 . 
         [0047]    The top member  14  can additionally include four pins  48 , with one pin  48  projecting perpendicularly from the first end  20  of the first sidewall  38  in a direction away from the second sidewall  40 , a second pin  48  projecting perpendicularly from the second end  26  of the first sidewall  38  in a direction away from the second sidewall  40 , a third pin  48  projecting perpendicularly from the first end  20  of the second sidewall  40  in a direction away from the first sidewall  38 , and a fourth pin  48  projecting perpendicularly from the second end  26  of the second sidewall  40  in a direction away from the first sidewall  38 . Additionally, each of the first and second sidewalls  38  and  40  can include an upwardly extending flange  47  defining an aperture  49 . The flanges  47  can be spaced along the length of the top member  14  from the hinge  32 , with the distance between the flanges  47  and the hinge  32  affecting the mechanical advantage provided by the lever  34 . 
         [0048]    The bottom member  16  can include a first sidewall  50  and a second sidewall  52  parallel to and spaced apart from the first sidewall  50 . A platform  54  can extend between the first and second sidewalls  50  and  52 , and a V-shaped ridge  56  can extend a length of the platform  54 . A first foot  58  can run a length of the first sidewall  50 , and the first foot  58  can extend away from the second sidewall  52 . A second foot  60  can run a length of the second sidewall  52 , and the second foot  60  can extend away from the first sidewall  50 . The feet  58  and  60  can provide stability for the clamp  10  when the clamp  10  rests on a desk or other surface. The bottom member  16  can additionally include four pins  62 , with one pin  62  projecting perpendicularly from the first end  22  of the first sidewall  50  in a direction away from the second sidewall  52 , another pin  62  projecting perpendicularly from the second end  28  of the first sidewall  50  in a direction away from the second sidewall  52 , a third pin  62  projecting perpendicularly from the first end  22  of the second sidewall  52  in a direction away from the first sidewall  50 , and a fourth pin  62  projecting perpendicularly from the second end  28  of the second sidewall  52  in a direction away from the first sidewall  50 . 
         [0049]    As shown in  FIGS. 6 and 7 , the first link  18  can include a backwall  64  and first and second sidewalls  66  and  68 , respectively, extending parallel to one another and generally perpendicular to the backwall  64  from opposing longitudinal edges of the backwall  64 . Each sidewall  66  and  68  can define two first apertures  70 , with the apertures  70  near opposing longitudinal ends of the sidewalls  66  and  68 . 
         [0050]    To rotatably couple the first link  18  to the top member  14 , the pins  48  and  62  projecting from the first end  20  of the top member  14  are inserted into the top apertures  70  in the first and second sidewalls  66  and  68 , respectively, of the first link  18 . Similarly, to rotatably couple the first link  18  to the bottom member  16 , the pins  48  and  62  projecting from the first end  22  of the bottom member  14  are inserted into the bottom apertures  70  in the first and second sidewalls  66  and  68 , respectively. These insertions can be accomplished by forming the first link  18  from a resilient material and snapping the first link  18  onto the top member  14  and bottom member  16 . 
         [0051]    As shown in  FIGS. 8-11 , the second link  24  can include a backwall  72  and first and and second sidewalls  74  and  76 , respectively, extending parallel to one another and generally perpendicular to the backwall  72  from opposing longitudinal edges of the backwall  72 . A tab  82  can extend from a top end of the backwall  78 . Each sidewall  74  and  76  can define an aperture  78  near the tab  82  and a slot  80  opening to a side of the sidewalls  74  or  76  opposite the backwall  72  near an end of the second link  24  opposite the tab  82 . 
         [0052]    To rotatably couple the second link  24  to the top member  14 , the pins  48  and  62  projecting from the second end  26  of the top member  14  are inserted into the apertures  78  of the first and second sidewalls  74  and  76 , respectively, of the second link  24 . To engage the second link  24  with the bottom member  16  as shown in  FIG. 3 , the second link  24  is rotated relative to the top member  14  toward the bottom member  16  until the pins  48  and  62  projecting from the second end  28  of the bottom member  16  are disposed in the slots  80  of the second link  24 . The tube  12 , if resilient, will be deformed between the top and bottom members  14  and  16  as shown in  FIG. 2 , and the tube  12  can thus exert of force urging the top and bottom members  14  and  16  away from each other. However, when the top member  14  is urged away from the bottom member  16  and vice versa, at least one of the pins  48  and  62  projecting from the second end  28  of the bottom member  16  contacts a bottom edge  83  of each slot  80  shown in  FIG. 9 , thereby preventing movement of the top member  14  away from the bottom member  16 . The force between the pins  48  and  62  projecting from the second end  28  of the bottom member  16  and the bottom edges  83  of the slots  80  can produce a friction force that aids the engagement between the second link  24  and bottom member  16 . With the second link  24  engaged with the bottom member  16 , the tab  82  can extend upward as shown in  FIG. 3 . 
         [0053]    Referring now to  FIG. 17 , the guillotine  30  can have a V-shaped edge  84 , which can face the V-shaped rib  56  of the platform  54  of the bottom member  16  as shown in  FIG. 5 . The V-shaped edge  84  and V-shaped rib  56  can act to create a high pressure location on the tube  12  when the clamp  10  is engaged with the tube  12 , thereby reducing the amount of force required to deform the tube  12 . Referring again to  FIG. 17 , the guillotine  30  can additionally include a longitudinally extending cross-bar  86  above a lower portion  88  of the guillotine  30  that includes the V-shaped edge  84 . The width of the lower portion  88  can be less than the distance between the first and second lip  44  and  46  of the top member  14 , thereby allowing the lower portion  88  to move below the lips  44  and  46  as shown in  FIG. 5 . The cross-bar  86 , however, can have a greater greater width than the distance between the first and second lips  44  and  46  such that the lips  44  and  46  limit the downward movement of the guillotine  30 . The guillotine  30  can be coupled to the hinge  32  as shown in  FIGS. 2 and 3 , which can be a pin passing through both the guillotine  30  and the top member  14 . The hinge  32  can limit upward movement of the portion of the guillotine  30  engaged with the hinge  32 . 
         [0054]    The lever  34  can include a T-shaped handle  90  and a shank  92  extending toward the hinge  33  as shown in  FIG. 16 . The proximal end of the shank  92  can include a pair of pins  93  extending through the apertures  49  in the flanges  47  of the top member  14 . The lever  34  can be coupled to the flanges  47  by forming the lever  34  of a resilient material and snapping the pins  93  into engagement with the flanges  47 . The shank  92  can have a width less than the distance between the sidewalls  38  and  40  of the top member  14  such that the shank  92  can fit between the sidewalls  38  and  40  when the lever  34  is engaged as shown in  FIG. 5 . Additionally, the handle  90  can fit snuggly against the tab  82  of the second link  24  when the lever  34  is engaged as shown in  FIG. 3 . The cam portion  36  of the lever  34  can extend further from a rotation axis of the lever  34  (i.e., an axis passing axially through the pins  93 ) than a bottom portion  94  of the lever  34  as shown in  FIG. 12 . Thus, the lever  34  can exert a greater downward force on the guillotine  30  as the lever  34  is rotated as shown in  FIGS. 12-14 , and thus rotation of the lever  34  can cause the guillotine  30  to exert a downward force on the tube  12 . The cam portion  36  can be of sufficient size to urge the guillotine  30  downward as shown in  FIG. 14  to fully close the tube  12 . 
         [0055]    The clamping sequence performed using the clamp  10  is shown in  FIG. 12-14  beginning with the top and bottom members  14  and  16  parallel and partially closing the tube  12  as shown in  FIG. 12  and ending with the tube  12  fully closed as shown in  FIG. 14 . Using the lever  34  to urge the guillotine  30  downward to close the tube  12  provides a mechanical advantage as a result of the distance between the handle  90  of the lever  34  and the pins  93  compared to the distance between the cam portion  36  of the lever  34  and the pins  93  as can be seen in  FIG. 14 . The clamp  10  provides another mechanical advantage in that there is a relatively long distance between where the cam portion  36  contacts the guillotine  30  and the hinge  33  as shown in  FIGS. 13 and 14 . As a result, the force required to fully close the tube  12  can be sufficiently low that the clamp  10  can be operated by hand without much difficulty. 
         [0056]    Alternatively, the clamp  10  can vary from the example described above. For example, instead of forming pins  48  and  62  that are integral with the top and bottom member  14  and  16 , respectively, separate pins can be inserted through apertures in the top and bottom members  14  and  16 . As another example, instead of the slots  80  held in engagement with the pins  48  and  62  due to friction between the second link  24  and bottom member  16 , the slots  80  can be formed to engage the pins  48  and  62  with a snap-fit. As still another example, instead of the hinge  32  that prevents movement of the guillotine  30  in an upward direction as shown in  FIGS. 13 and 14 , a stop or other structure can be used to limit the upward movement of the guillotine  30 . As still yet another example, a different structure can be used to provide a mechanical advantage for closing the tube  12 . An example of such a different structure is the lever  34  including a ratchet portion at its proximal end, and the guillotine  30  including a vertically oriented rack of gear teeth engaged with the ratchet portion of the lever  34  for vertical movement of the guillotine in response to rotation of the lever  34 . 
         [0057]    The clamp  10  can offer many advantages. As an example of an advantage of the clamp  10 , the clamp  10  can be installed on the tube  12  even if the tube  12  is of the over-sized variety without requiring an amount of force greater than that which can be applied by hand without significant straining (e.g., without the user having to apply his bodyweight to the clamp  10 ). As another example of an advantage of the clamp  10 , the clamp  10  can be installed on an intermediate portion of the tube  12  without having to thread the clamp  10  onto an end of the tube  12 . 
         [0058]    Another example of a clamp  110  is shown in  FIGS. 18 and 19 . Referring first to  FIG. 18 , the clamp  110  can include a top member  114  rotatably coupled to a bottom member  116 . The top and bottom members  114  and  116  can have similar structures as the top and bottom members  14  and  16  with the exception of a few differences. One such difference can be that instead of being rotatably coupled by the first link  18 , first ends  120  and  122  of the top and bottom members  114  and  116 , respectively, can define a hinge  118 . For example, the first end  120  of the top member  114  can define two spaced apart sidewalls  118   a  and  118   b , and the bottom member  116  can define a pin  118   c  extending through apertures  118   d  in the two sidewalls  118   a  and  118   b . A second link  124  similar to the second link  24  can be rotatably coupled to a second end  126  of the top member  114  and engagable with a second end  128  of the bottom member  118 . A lever A lever  134  can be coupled to a hinge  133  that is similar to the hinge  33 , and the lever  134  can include a cam portion for actuating a guillotine carried by the top member  114  in a similar fashion as to how the cam portion  36  actuates the guillotine  30  carried by the top member  14 . 
         [0059]    Another difference between the clamps  10  and  110  is that the lever  134  can become automatically locked in engagement with another portion of the clamp  110 , such as the top member  114  or second link  124 , in response to being rotated into an actuated position shown in  FIG. 18  in which the cam portion actuates the guillotine. For example, as shown in  FIGS. 18-20 , a distal end  136  of the lever  134  can define a button  138 . The button  138  can be rotatable about an axis, e.g., an axis parallel to an axis of rotation of the lever  134  about the hinge  133 . An example of the button  138  shown in  FIG. 20  can be connected to a remaining portion of the lever  134  by two tabs  138   a  and  138   b , and spaces  141  can be defined between the button  138  and the remaining portion of the lever  134 . 
         [0060]    Referring to  FIG. 19 , a projection  140  can extend from a side of the button  138  facing the bottom member  116  and can include a barb  142  at its distal end opposite the button  138 . The barb  142  can include an angled surface  142   a  such that the surface  142   a  contacts a crossmember  144  extending between two sidewalls of the top member  114  during rotation of the lever  134  into the actuated position. The angle of the surface  142   a  can allow the barb  142  to produce a force urging the projection  140  and/or button  138  to rotate such that the barb  142  is allowed to slide past the crossmember  144 . Once the barb  142  slides past the crossmember  142 , the barb  142  can engage a side of the crossmember  144  facing the bottom member  116  as a result of, for example, tubing  12  compressed between the top and bottom members  114  and  116  urging the members  114  and  116  away from one another. With the barb  142  engaged with the crossmember  144 , the top member  114  is locked in the actuated position. To release the top member  114  from the actuated position, the button  138  can be rotatable in the direction indicated by the arrow shown in  FIG. 19  as a result of being compressed by, for example, a finger or thumb of an operator. Rotation of the button  138  in the direction indicated in  FIG. 19  can move the barb  142  such that it does not engage the crossmember  144 , and the force created by compressed tubing  12  between the top and bottom members  114  and  116  can urge the members  114  and  116  away from one another. 
         [0061]    While an automatic locking feature is shown as including the button  140  and the projection  140  with its barb  142 , other automatic locking structures can be used. For example, one or more projections with barbed distal ends can extend upward from the top member  114  for engagement with a portion of the lever  114  when the lever is moved into the actuated position. As another example, the lever  134  can include a barbed projection that engages the second link  124  instead of the top member  114 . 
         [0062]    The clamp  110  can offer the same advantages as the clamp  10 . Additionally, the clamp  110  can allow the top member  114  to be automatically lockable in response to being moved into an actuated position relative to the bottom member  114 , and the automatic lock can be selectively disengaged. 
         [0063]    Another example of a clamp  210  is shown in  FIGS. 21-29 , which can offer the same advantages as the clamp  10  and  110 .  FIGS. 21 and 22  illustrate the clamp  210  in an unengaged position and  FIGS. 23-29  illustrate the clamp  210  in an engaged position (without the tube  12 ). The clamp  210  can include a top member  214  rotatably coupled to a bottom member  216 . The leverage of bottom member  216  can permit the clamp  210  to restrict the fluid flow in, for example, heavy wall tubing similar to that shown in  FIG. 1 . Similar to the coupling of top and bottom members  114  and  116 , first ends  220  and  222  of the top and bottom members  214  and  216 , respectively, can define a hinge  218 . For example, the first end  220  of the top member  214  can define two spaced apart sidewalls  218   a  and  218   b , and the bottom member  216  can define a pin  218   c  extending through apertures  218   d  in the two sidewalls  218   a  and  218   b.    
         [0064]    A link  224  can be rotatably coupled to a second end  226  of the top member  214  and engagable with a second end  228  of the bottom member  218 . Two stop members  233  extend from the top member  214  that assist in preventing the link  224  from over-travel. A lever  234  can be coupled to a hinge  233  that is similar to the hinge  133 , and the lever  234  can include a cam portion  236  for actuating a guillotine  230  carried by the top member  214  in a similar fashion as to how the cam portion  36  actuates the guillotine  30  carried by the top member  114 . Guillotine  230  may also be interchangeable with other guillotine members that can accommodate tubing of, as discussed previously, different inner and outer diameters. Although only one tube is shown in  FIG. 21 , clamp  210  can be capable of clamping multiple tubes at one time. 
         [0065]    As shown in  FIGS. 23-29 , the lever  234  is automatically locked in engagement with with the top member  214  although the lever  234  may be automatically locked in engagement with another portion of the clamp  210  such as second link  224 . The lever  234  is automatically locked in response to being rotated into an actuated position shown in which the cam portion  236  actuates the guillotine  230 . The top member  214  can also include safety lockout holes  235  that can be used in conjunction with, for example, a cable tie (not shown) to prevent the lever  234  from being unlocked once it has been rotated into the actuated position. The operator can thread the cable tie through the holes  265  and secure it tightly around the lever  234 . Of course, other types of fasteners can be used to prevent the lever from being unlocked, which may or may not make use of the holes  265 . 
         [0066]    Unlike previous embodiments, the clamp  210 , as shown in  FIGS. 21-27 , can include buttons  238   a  and  238   b  (e.g. pushbuttons) at the second end  236  of top member  210 . Upon rotation into the engaged position, two projections  239  and  240  extending from lever  234  and facing the bottom member  216  can be inserted into a mating hole  260 . Mating hole  260  is formed by two arms  250   a  and  250   b  laterally extending from button  238   a  and two arms  252   a  and  252   b  laterally extending from button  238   b . The arms  250   a  and  250   b  have a sidewall  260   a  extending therebetween forming a first wall  260   a  of mating hole  260 . The arms  252   a  and  252   b  have a sidewall  250   b  extending therebetween forming a second sidewall  260   b  of mating hole  260 . Extending through an inner portion of the arm  252   a  is a recess (not shown) that is shaped to slidably receive arm  250   a . Similarly, extending through an inner portion of the arm  252   b  is a recess shaped to slidably receive arm  252   a . The mating of arms  250   a  and  252   a  and the mating of arms  250   b  and  252   b  form a third sidewall  260   c  and a fourth sidewall  260   d , respectively, of mating hole  260 . 
         [0067]    Projections  239  and  240  each include a barb  241  and  242 , respectively at the distal end thereof. The barbs  241  and  242  each have an angled surface  239   a  and  240   a , respectively. The angle of the surfaces  239   a  and  240   a  can allow the barbs  241  and  242  to produce a force urging the buttons  238   a  and  238   b  to expand away from one another such that the barbs  241  and  242  are allowed to slide past the sidewalls  260   a  and  260   b , respectively. Specifically, the arm  250   a  and the arm  252   a  slidably extend outward in opposing directions and at the same time and the arm  250   b  and the arm  252   b  slidably extend outward in opposing directions. Once the barb  241  slides past the sidewall  260   a , the barb  241  can engage a side of the button  238   a  facing the bottom member bottom member  216 . Similarly, once the barb  242  slides past the sidewall  260   b , the barb  242  can engage a side of the button  238   b  facing the bottom member  216 . With the barbs  241  and  242  engaged within mating hole  260 , the top member  214  is locked in the engaged position. Once the clamp  210  is in the engaged position, the clamp, for example, will not open, unless the lever  234  is unlocked. 
         [0068]    To release the top member  114  from the engaged position, the buttons  238   a  and  238   b  can be inwardly and simultaneously pressed, for example, by a finger and a thumb of an operator. Pressing of the buttons  238   a  and  238   b  results in a force that causes the arm  250   a  and the arm  252   a  to slidably extend toward one another and, at the same time, and causes the arm  250   b  and the arm  252   b  to slidably extend toward one another thereby permitting the barbs  241  and  242  to disengage from the sides of buttons  238   a  and  239   b , respectively, facing the bottom member  216 . The link  224  can then be pulled from the bottom member  216 , thereby permitting the tube  12  to be removed. 
         [0069]    Similar to the previous embodiments, when link  224  is not engaged with the bottom member  216 , as shown in  FIG. 1 , the top member  214  can be rotated relative to the bottom member  216 . To engage the clamp  210  with the tube  12 , the top member  214  can be rotated away from the bottom member  216  such that there is a sufficient distance between the top and bottom members  214  and  216  to insert the tube  12  therebetween. With the top and bottom members  214  and  216  rotated sufficiently apart from one another, the clamp  210  can be moved to position the tube  12  between the top and bottom members  214  and  216 , and then the top member  214  can be rotated toward the bottom member  216 . 
         [0070]    The link  224  can be engaged with the second end  228  of the bottom member  216  to hold the top and bottom members  214  and  216  in a relatively parallel position. The bottom member  216  can be engaged to one of two curved hook members  266  and  268 . Hook member  266  permits clamp  210  to be in a first engaged position (“stop flow position”), hook member  268  permits clamp  210  to be in a second engaged position (“start flow position”). In both positions, each of the hooks  266  and  268  is engageable with an engagement platform  272  of bottom member  216 . A spring  269  extends from link  224  that can aide in closing the link back over the hook members  266   268 . A curved stop member  274  extends from the platform  272  to maintain the clamp  210  in either the first engaged position or the second engaged position. Using the lever lever  234 , the operator can control the amount of fluid flowing through tube  30 . In general, the more the lever  234  is rotated toward the top member  214  in the actuate position, the more the guillotine  230  closes on the tube. As the guillotine  230  closes on the tube, the fluid flow decreases accordingly. Conversely, if the operator desires to increase the fluid flow, the lever  234  can be rotated in away from the top member  214 . The flow can be metered in both the first engaged position and the second engaged position. 
         [0071]    The locking link  226  includes two telltale windows  276  and  278  to indicate a flow position of the clamp  210 . Specifically, when the hook member  266  is engaged with the platform  272 , the telltale window  276  provides the operator with a visual indicator that the clamp  210  is in the stop flow position. Similarly, when the hook member  268  is engaged with the platform  272 , the telltale window  278  provides the operator with a visual indicator that the clamp  210  is in the start flow position. 
         [0072]    While examples of clamps have been described in connection with what are presently considered to be the most practical examples, it is to be understood that the invention is not to be limited to the disclosed examples but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as is permitted under the law.