Abstract:
A quick coupling for a flexible tube has an outer annular element with a bayonet connection and a central bore which receives an annular insert having two arcuate sections and holding the flexible tube in place through barbs. The inserts are removable from the outer annular coupling by means of a detent at which point the arcuate sections may be easily removed from the flexible tube.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to couplers and, more particularly, to quick couplings for flexible tubes that may be used in seed planters. 
     2. Description of the Related Art 
     An agricultural seeder, such as a row crop planter, places the seed at a desired depth within a plurality of parallel seed trenches (or furrows) formed in soil. In the case of a row crop planter, a plurality of row crop units are typically ground driven using wheels, shafts, sprockets, transfer cases, chains and the like, or driven by a hydraulic or electric motor based on ground speed obtained from electronic sensors. Each row crop unit has a seed metering and distribution mechanism to properly meter seeds at a predetermined rate and to place the seeds at predetermined spaced locations and depth. The row crop unit is movably coupled with a tool bar and includes a mini hopper for seed. The row crop planter usually carries a main seed hopper or bulk fill tank which employs flexible tubes to distribute seed to the mini hoppers in each of the row crop units. The seeds are pneumatically driven along the tube between the bulk fill tank and the mini hoppers. 
     The operating environment for the row crop planter is such that the flexible tubes need to be quickly disconnected from both the bulk fill tank and especially the mini hoppers. Quick connect couplings are used for this purpose. It is common practice to utilize hose barbs on the quick coupling to positively retain the flexible tube in place. While it is an easy process to install the flexible tube in the coupling, it is problematic to remove the tube for various maintenance purposes. The reason is that the hose barbs do not permit removal of the flexible tube from the coupling without either heating and or splitting of the tube. This process requires the flexible tube to be shortened if the tube is to be reused in the coupling. After just a few occurrences of this operation, the length of the flexible tube may be shortened enough that it did becomes unusable. 
     What is needed in the art is a quick coupling that enables removal of the flexible tube from the quick coupling and be reused without damage to the tube. 
     SUMMARY OF THE INVENTION 
     The present invention provides the ability to reuse a flexible tube after removal from a quick coupling. 
     The invention, in one form, is directed to a quick coupling for a flexible tube. The coupling includes an outer annular coupling element having a quick disconnect attachment feature and a central bore. An annular insert has at least two arcuate sections connectable to one another to form an outer annular surface received within the central bore. The insert has an inner annular surface having a diameter sized to receive the end of the flexible tube with the annular insert having at least one barb element formed on the interior surface and oriented to resist removal of the tube. The outer annular surface of the insert and the central bore of the outer annular coupling element cooperate to form a detent for removable retention of the insert and the tube within the coupling. Removal of the insert permits the arcuate sections to be removed from the flexible tube. 
     The invention, in another form, is directed to a row crop planter including a frame securable to a tractor and wheels on the frame for movement over the soil. A storage bin for seeds is mounted on the frame and a plurality of row crop units are mounted to the frame for planting seeds in the soil. A flexible tube extends from the storage bin to the individual row crop units for supplying seeds to each of the row crop units. A quick coupling is secured to the flexible tube for connecting the flexible tube to at least one of the storage bin and individual row crop units. The quick coupling includes an outer annular coupling element having a quick disconnect attachment feature and a central bore. An annular insert has at least two arcuate sections connectable to provide an outer annular surface and an inner annular surface having a diameter sized to receive the end of the flexible tube, with the annular insert having at least one barb element formed on its interior surface and oriented to resist removal of the tube from the insert. The outer annular surface of the insert and the central bore of the annular coupling element cooperate to form a detent for removable retention of the insert and the tube within the coupling to permit removal of the insert from the flexible tube. 
     An advantage of the present invention is undamaged removal of a flexible tube from a quick coupling. 
     Another advantage is reuse of flexible tubes after removal from a quick coupling. 
     Another advantage is to improve the physical retention and/or the air tightness of the coupling across a larger range of hose outer diameters, by allowing for inserts of different thicknesses or inserts made with a resilient material. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a perspective view of a seed planter with which the quick coupling of the present invention is used. 
         FIG. 2  is a longitudinal section view of the quick coupling used in  FIG. 1 ; and, 
         FIG. 3  is a perspective view of a component of the quick coupling of  FIG. 2 . 
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates one embodiment of the invention and such exemplification is not to be construed as limiting the scope of the invention in any manner. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings, and more particularly to  FIG. 1 , there is shown a row crop planter  10  which includes a central frame  12  positioned to be secured to and towed behind a tractor or other work vehicle. They row crop planter  10  includes a transversely oriented toolbar  14  connected to the frame  12  and supporting a plurality of wheel assemblies  16  for movement across soil. Bulk fill tanks  18  are supported on frame  12  and provide the initial storage for seeds to be distributed to the soil. 
     A plurality of row crop units  20  are positioned at spaced locations along toolbar  14 . Details of the internal mechanism of the row crop units are not discussed to enable a better understanding of the invention. However, the row crop units open the soil to a predetermined depth and meter, position and cover-up seeds at predetermined spacing before covering the seeds. A series of flexible tubes  22  extend from the bulk fill tanks  18  to the row crop units  20  and are connected to mini hoppers  26  for seeds by a quick coupling  24 . 
     In accordance with the present invention, the quick coupling  24  shown in  FIGS. 2 and 3  is utilized with flexible tube  22  to enable reuse of the tube  22  after removal from the quick coupling  24 . Referring specifically to  FIG. 2 , the quick coupling  24  includes an outer annular coupling element  28  which has a central bore  30 . A quick disconnect attachment feature  32  is included into an integral expanded annular end section  34  of the coupling element  28 . End section  34  has a bayonet connecting slot  36  which cooperates with a tubular element  38  secured to the mini hopper  26 . The tubular element  38  has bayonet engaging tabs  40  that cooperate with bayonet slot  36  to enable quick installation and removal of the coupling  24 . 
     An annular insert  42  has arcuate half sections  44  and  46 , shown specifically in  FIG. 3 . The arcuate half sections  44  and  46  have outer annular surfaces  48  and  50 , respectively which are sized to be received within a central bore  30  of the outer annular coupling element  28 . The arcuate half sections  44  and  46  also have inner annular surfaces  52  and  54  sized to receive flexible tube  22 . Annular barbs  56  and  58  are provided on the inner annular surfaces  52  and  54  of the arcuate halves  44  and  46 , respectively. Annular barbs  56  and  58  have a protrusion that extends into the outer surface of flexible tube  22  and is angled to prevent removal or movement of the tube out of the annular insert  42 . While a pair of barbs  56  and  58  are shown, any number of barbs may be employed for adequate sealing and retention. In addition, the barbs may be eliminated and the tube  22  held by friction against annular surfaces  52  and  54 . 
     As illustrated in  FIG. 3 , the arcuate sections  44  and  46  are joined by an integral axially extending hinge  60  that is typically used for parts made of plastic. It should be noted however, that the arcuate halves  44  and  46  may be utilized as separate pieces. Furthermore, more than two arcuate sections may be employed in the quick coupling  24 . 
     In order to position the end of the flexible tube  22  at a predetermined axial position, inward directed flanges  62  and  64  are provided at one end of the arcuate half sections  44  and  46 , respectively. Outward directed flanges  66  and  68  on the arcuate sections  44  and  46  provide a limit to the depth to which the insert  42  and flexible tube  22  extend into the outer annular coupling element  28 . When the arcuate sections  44  and  46  are joined by an integral hinge as shown in  FIG. 3 , overlap edges  70  and  72  are provided to enable better sealing of the annular insert  42 . A detent feature is provided between the outer annular coupling element  28  and the annular insert  42  by providing an inward directed protrusion  74  in the form of a ramp on interior bore  30  and a recess  76  on the outer annular surfaces  48  and  50  of the arcuate halves  44  and  46 . 
     In operation, the flexible tube  22  is inserted into annular insert  42  against end flanges  62  and  64 . Annular insert  42  is then inserted into outer annular coupling element  28  so that the protrusion  74  is seated in recess  76 . The quick coupling attachment feature  32  may be employed to connect flexible tube  22  to the tubular element  38 . If it is necessary to remove the tube  22 , the quick coupling  24  is first disengaged from tubular element  38 . When it is necessary to remove the flexible tube from the quick coupling  24 , it is simply pulled out axially past the detent. The flexibility of the annular insert  42  allows the insert to be removed from the central bore  30 . Once it is removed, the arcuate sections  44  and  46  they may be removed in a radial direction so that any operation may be performed on the flexible tube  22  by itself. It should be noted that the arrangement of the arcuate sections permits removal of the flexible tube  22  from the quick coupling  24  without damage to the tube  22 . This greatly facilitates reuse of the tube without altering its length. 
     While this invention has been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.