Abstract:
Apparatus to connect a flexible tube to a spigot on bio-disposable systems. The apparatus comprises a support for a spigot and jaws for gripping and holding a flexible tube. The jaws open and close for insertion of the flexible tube either under manual or pneumatic force. The jaws also include a front section that is openable against a resistance. In use, the end of the spigot is place inside the end of the flexible tube, the spigot is then positioned on the support, and the tube clamped into the jaws. Either on manual or pneumatic action, the spigot is advanced into the flexible tube within the jaws. The front section of the jaw opening slightly to accommodate the spigot, while the back section of the jaw holds the tube firmly in position.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to apparatus for connecting a flexible tube to a spigot, barb, or the like. 
         [0003]    2. Description of Related Art 
         [0004]    In the food, medical and pharmaceutical industries single use apparatus, or bio-disposable systems, can be used in the preparation of batches of product. Such single use apparatus includes flexible tubing, typically made from silicone, but may be made from other plastics materials, such as thermoplastics. Connections to other pieces of apparatus are commonly made with flanged connectors clamped to each other. The connectors have hollow spigots to which a tube is connected in a fluid tight manner. Connections to other pieces of apparatus can also made using hollow spigots. These spigots are generally provided with barbed ends to retain the tubes. 
         [0005]    It is important that this connection between the flexible tube and hollow spigot is fluid tight as fluid leaking between this connection would be lost to the process and when using valuable fluids any loss can be significant. It is particularly important that the connection is stable for the lifetime of the apparatus, because if the connection were to fail, the whole batch may be lost. To prevent disconnection and leaks, the connection is very tight, with the profile of the barb extending slightly beyond the normal diameter of the tube causing slight stretching of the tube around the barb, and therefore making disconnection of the tube from the spigot unlikely to occur. However, this of course makes connecting the tube to the spigot also difficult. 
         [0006]    To aid connection, a lubricant, such as alcohol or oil, can be used. However, this can ease both the connection between the tube and the spigot and the disconnection. In addition, the lubricant can seep into the apparatus and contaminate the reaction chemicals and solvents, and the products. Thus it is preferable to avoid the use of such lubricants. 
         [0007]    Apparatus has been developed to insert a spigot into a flexible tube, however, these typically incorporate the use of fingers inside the flexible tube to pull the tube open so the spigot can be inserted. While this certainly aids insertion of the spigot into the tube, the use of fingers adds potential contamination into the apparatus and risks damage to both the tube and the spigot. In addition, various types of plastic tubing, in particular thermoplastic tubing, does not return fully to shape once stretched. Thus the use of this type of apparatus to pull the tube open can lead to a permanently enlarged tube and thus a poor connection. 
       SUMMARY OF THE INVENTION 
       [0008]    The object of the present invention is to provide improved apparatus for inserting a spigot into a flexible tube. 
         [0009]    According to the invention there is provided apparatus for inserting a spigot into a flexible tube, the apparatus including
       means for supporting and advancing a spigot and   means for gripping a flexible tube, while the spigot is inserted therein,
           the gripping means including a pair of jaws for gripping and releasing the tube, with sufficient strength to hold the tube but not crush the same,   at least part of one or both jaws being moveably mounted against a resistance such that under the force of the advancing spigot at least part of one of both jaws can release sufficiently to allow the spigot to pass into the tube, while retaining the tube in the apparatus.   
               
 
         [0014]    Preferably the jaws are tapered at their front edges to ease insertion of the spigot. Typically the jaws are provided with fine grooves or ridges to aid grip on the flexible tube. Preferably the jaws are contoured in accordance with the shape of the spigot. 
         [0015]    To position and remove a tube, the jaws will preferably be mounted on runners. A cam rotated by a lever may be provided to move the jaws along the runners to open and close the same. In addition, in the absence of cam movement at least part of the jaws are mounted again spring force, enabling them to be moved against the spring to open and close under the force of the advancing spigot. 
         [0016]    Advantageously, a front section of the jaws, typically a tapered section, may moveable against a resistance, with a back section of the jaws, generally not tapered, holding the tube in a fixed position while the jaws are closed. 
         [0017]    The movement of the jaws, both for positioning to hold the flexible tube, and against a resistance can be provided manually, mechanically, electrically or pneumatically, the device being operated manually or electronically. 
         [0018]    Typically the whole apparatus will be steralizable, generally in an autoclave. 
         [0019]    Advantageously the jaws can be removable to enable jaws contoured for different shapes of spigot to be easily inserted. In addition, it is possible to adjust the stroke of the supporting means. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]    To help understanding of the invention, a specific embodiment thereof will now be described by way of example and with reference to the accompanying drawings, in which: 
           [0021]      FIG. 1  is a perspective view of a tube applicator according to the invention; 
           [0022]      FIG. 2  is a front view of the jaws of the tube applicator of  FIG. 1 ; 
           [0023]      FIG. 3  is a top view of the jaws of the tube applicator of  FIG. 1 ; 
           [0024]      FIG. 4  is a top view of a spigot being connected to a tube using the applicator of  FIG. 1 ; 
           [0025]      FIG. 5  is a top view of the connection of  FIG. 4  at a more advanced stage; and 
           [0026]      FIG. 6  is a front view of the jaws of a tube applicator according to a second aspect of the invention; 
           [0027]      FIG. 7  is a top view of the apparatus according to a third embodiment of the invention; 
           [0028]      FIG. 8  is a perspective view of one of a pair of jaws from the embodiment of  FIG. 7   
           [0029]      FIG. 9  is a sectional view of the jaw of  FIG. 8 ; 
           [0030]      FIG. 10  is a top view of the apparatus of  FIG. 7  with a spigot positioned on the support and a tube positioned between the jaws; 
           [0031]      FIG. 11  is a top view of the apparatus of  FIG. 7  with the spigot advanced slightly with respect to  FIG. 10 ; and 
           [0032]      FIG. 12  is a top view of the apparatus of  FIG. 7  with the spigot advanced further with respect to  FIG. 11 . 
       
    
    
     DETAILED DESCRIPTION 
       [0033]    Referring to  FIGS. 1 to 5 , the apparatus  1  includes a base  2  on which is mounted a support  4  for a connector C having a spigot S. The spigot, as shown, has a barbed end B. While barbed end spigots are the most commonly used, the device could be used with a spigot with a parallel end. As shown this connector may be a flanged connector but may also be a T-connector, a Y-connector, adaptors, or any other type of device to which a flexible tube is connected over a spigot, including filters and the like. 
         [0034]    The support  4  is mounted on a pair of runners  6  to allow it to be advanced forward and retreated backwards along the base  2 . Advancement and retraction is achieved by means of a lever  8 , although any other type of mechanical, electrical or pneumatic system could be used. The support  4  includes a block  10 , mounted on runners to be moved by lever action, and an attachment  12 , removably connected to the block, designed to support the chosen connector. As shown the attachment  12  is for a flanged connector C, and comprises a rod  13  onto which the flanged connector is placed, the flange being supported against the support  4 . However, other attachments can be used to support different connectors. The attachment  12  also allows for variations in the size of the connector to still be connected to the flexible tube. The movement along the runners can be set to adjust the stroke of the forward motion of the support, which will depend upon the shape and length of the spigot. 
         [0035]    In addition, the base also carries a grip  14  for the flexible tube T. The grip  14  includes a pair of jaws  16 . These are supported on a pair of carriers  18  and the jaws  16  can be changed in accordance with the diameter of the tube and/or the size and profile of the spigot to be inserted. When positioned on the carriers  18 , the jaws  16  face the support  4  and attachment  12 , and are aligned such that a tube held in the jaws  16  will be directly facing the spigot S of a flanged connector C held on the attachment  12 . 
         [0036]    The jaws  16  are slightly flared  20  at the end facing the attachment  12 , and are provided with a series of grooves  22  to enhance the grip to the flexible tube. While the jaws are shown with grooves, ridges other forms of texture could additionally or alternatively be provided. In addition, the jaws are also contoured in accordance with the shape of the spigot, and in particular the shape and diameter of the barb on the spigot. While a generally flared pair of jaws will be satisfactory for a wide range of shapes of barbed spigot, in the preferred embodiment, the jaws are contoured in accordance with the specific contour of the barb to be inserted into the tube. 
         [0037]    The carriers  18  are held on a pair of runners  24 , secured to side supports  26 , mounted on the base  2 . Between the carriers  18  and the supports  26  are provided a pair of springs  28 . These act to urge the carriers  18  into position on the runners. The carriers are also acted on by a cam  29  secured to the based underneath the runners. The cam  29  is rotated using a lever  30 , and the shape of the cam  29  moves the carriers  18  between an open position, at which the flexible tube T can be inserted between the jaws, and removed, and a closed position in which the flexible tube is griped between the jaws. The jaws  16  grip the flexible tube T will sufficient force to hold it in position, but not crush it. However, on insertion of the spigot S into the flexible tube T, the jaws are able to move against the action of the springs, forcing them to open slightly to accommodate the barbed end section, while still maintaining a holding force on the tube. 
         [0038]    The design of the jaws maintaining a holding force of the tube, while allowing expansion of the tube to accommodate the spigot as it is inserted therein, enables the apparatus to be effective. Where a barbed spigot is used, a slight expansion of the tube is required to accommodate this, which would not be possible with fixed jaws. Thus the resistive element in the jaws enables the expansion of the tube under force from the incoming barbed spigot, while still maintaining a holding force on the jaws. It is the design of the jaws to hold the flexible tube but to move sufficiently under force of the insertion of the spigot, which allows the apparatus to function. 
         [0039]    Referring now to  FIGS. 4 and 5 , in use a connector C having a spigot S is placed on the support  4 . The jaws  16  are opened, a length of flexible tube T is positioned between the jaws and the jaws are closed to securely hold the tube but not to crush the same. The tube T is positioned so that its end is just touching the end of spigot S, as shown in  FIG. 4 . In practice the best way of achieving this contact is for an operator to push the end of the spigot into the end of the tube. This initial connection can be achieved easily, in contrast to the full connection over the barbed spigot. The tube and spigot combination can then be fitted onto the apparatus. The lever  8  is then moved to advance the spigot into the flexible tube. As the spigot advances, the pressure of the advance moves the jaws  16  very slightly towards the supports  26 , increasing the distance therebetween to allow the spigot to be inserted into the tube. As can be seen in  FIG. 5 , the jaws are slightly further apart than in  FIG. 4  to allow for the insertion of the spigot. However, the jaws still maintain a holding force on the tube preventing any significant backwards movement of the same away from the spigot. Once the spigot has been inserted to the correct depth, the lever  8  can be released. This draws the support  4  away from the jaws  16 , leaving the spigot in the tube, in the jaws. The lever  30  can then be used to open the jaws and remove the spigot S now fitted to the tube T. 
         [0040]    Turning now to  FIG. 6 , the embodiment thereshown is essentially identical to that shown in  FIG. 1 , with the exception that the movement of the jaws  116  is controlled by pneumatic cylinders  132 . The jaws  116  are mounted between two pairs of cylinders,  134 ,  136  that control their movement. The first pair of cylinders,  134  act in the same way as the cam in the first embodiment, i.e. to move the jaws from an open position in which the flexible tube can be inserted and removed, and a closed position in which the flexible tube is griped securely but not crushed. The second pair  136  of cylinders acts in the same way as the springs in the first embodiment, namely to allow a small degree of opening of the jaws to accommodate the spigot as inserted into the tube, by means of check valves. The movement is controlled by a microprocessor (not shown). Alternatively, a single pair of cylinders can act both for the movement of the jaws between an open and closed position, and to allow a slight opening in the jaws to accommodate the entry of the spigot into the tube. 
         [0041]    Referring now to  FIGS. 7 to 9 , which show apparatus for inserting a spigot into a tube according to a third aspect of the invention. Similarly to the previous embodiments, the apparatus  200  includes a base  202  for supporting the apparatus. Provided on the base is a support  204  for holding a connector having a spigot S. The support  204  is readily changeable on the apparatus and each support will be designed to securely hold a different type or size of connector. As shown the connector is a flanged connector, but may also be a T- or Y-connector, and adapter, or any other device to which flexible tube is connected, including for example a filter. The support  204  shown is designed for use with a flanged connector and is provided with an elongated nose  205 . The nose  205  is sized for entry into the flexible tube, to act as a guide to ensure that the spigot S is correctly inserted into the tube T. This removes the necessity of pre-connection of the end of the spigot S into the flexible tube T before operation of device to force the spigot fully into the tube, as described in reference to the first embodiment. The support  204  is mounted on the base for movement under piston control (not shown). 
         [0042]    Also provided on the base, again similar to the previous embodiment, is a grip  214  for a flexible tube T. The grip includes a pair of jaws  216 , which are mounted for movement under piston control. 
         [0043]    The jaws  216  comprise a main element  220  and a compressible front section,  222 . The front section  222  fits into the main element  220  with a spring  224  positioned between the two, enabling movement of the front section relative to the main section. Both sections are provided with an indentation to accommodate the flexible tube T, with the front section having a flared portion at the front to accommodate the barb of the spigot. The whole of the jaw is easily replaceable to accommodate different sizes of tube and spigot, with the front section being further replaceable to accommodate the profile of the spigot. The front section  222  will generally be very slightly longer than the spigot to be inserted into the tube and profiled accordingly. The jaws and particularly the indented sections will be provided with small ridges and/or indentations to increase the grip onto the tube. 
         [0044]    Typically the jaws will be made out of plastics material, however they could also be made out of metal, wood or any other suitable material. However, the compressive section  222  of the jaws will generally be made out of a metal, for example stainless steel. This is because it has been found that the slight movement of the tube within the jaws, on insertion of the spigot, has a tendency to polish the jaws, which can lead to a reduction or even loss of grip and less satisfactory working of the device. As metal is generally harder than plastics material, it is more resistant to the polishing. For devices that will experience a heavy use, it has been found that metal jaws are significantly more durable that plastics jaws. It has also been found that polishing is experienced on the compressible jaw only as this is where movement occurs. Thus the fixed jaw will typically be made of plastics material. 
         [0045]    The jaws are designed to be easily replaceable, with the jaws  216  comprising contoured projections, which mate with contoured indentations in the grips  214 . Thus the jaws can be replaced to suit different contours spigot, and different sized of flexible tube and spigot. 
         [0046]    The base also holds a microprocessor  226  for controlling the movement of both the jaws  116  and the connector support  204 . Buttons  228  will be provided connected to the microprocessor for controlling movement of these elements. 
         [0047]    Referring now to  FIG. 10-12 , in use, initially the support  204  is retracted and jaws  216  are opened. A spigot S is positioned on the support  204  and a flexible tube of the corresponding size is placed between the jaws, which are then closed. In this position, the nose  205  of the support is just inside the end of the flexible tube T, as shown in  FIG. 10 . The support then advances, with the nose  205  of the support extending inside the tube T and guiding the spigot therein.  FIG. 11  shows the spigot just starting to enter the tube. As the spigot is forced into the tube T, the front section  222  of the jaws  216  retracts into the main section of the jaws  220 , to allow for the increasing width of the spigot. The main section of the jaws  220  holding firmly to the tube.  FIG. 12  shows the spigot a significant way into the tube, with the front section of the jaws retracted to allow for the entry of the barb. Once the spigot has been pushed into the tube, the jaws are opened and the spigot and tube removed. 
         [0048]    The invention is not intended to be restricted to the details of the above-described embodiment. For instance, any combination of pneumatic or other powered control can be used in combination with manual operation for the different elements of movement required in the device.