referring first to fig1 there is illustrated a typical quick connect tubular coupling arrangement of the type depicted in u . s . pat . no . 4 , 055 , 359 . a smaller diameter tube 10 telescopically fits as slides into a larger diameter tube 12 . the outside diameter of the smaller diameter tube 10 is slightly less than the inside diameter of the larger diameter tube 12 . an annular cage 14 is afixed to the outside surface 16 of the smaller diameter tube 10 at a fixed distance from the end 18 of the smaller diameter tube 10 . the cage 14 includes an annular , circumferential slot 20 into which the tube 12 may be inserted . the tube 12 includes an end flange 22 which is outwardly and upwardly flared and which also fits through the slot 20 . a circular , compression spring 24 is retained within the cage 14 . the spring 24 compresses against the tube 12 and normally rests against the forward surface 26 of the flange 22 and also against the inside front edge of the cage 14 adjacent slot 20 to thereby retain the tube 12 in position locked by the interaction of spring 24 with the cage 14 . in this manner , the tube 12 cannot be withdrawn from telescopying engagement with the tube 10 inasmuch as the spring 24 in effect is locked against the forward edge of the cage 14 and therefore the flange 22 cannot be withdrawn through the slot 20 . typically grooves are provided in the tube 10 , such as grooves 28 , about the circumference of the smaller diameter tube 10 , into which o - rings 30 are inserted so that when the tube 10 is telescopically inserted into the tube 12 there is sealing engagement between the tubes 10 , 12 . in order to decouple or disconnect the tube 10 from the tube 12 it is known , by reference to u . s . pat . no . 4 , 055 , 359 , that it is necessary to engage the circular , compression spring 24 and push that spring 24 upwardly onto the top of the flange 22 . this will permit the larger diameter tube 12 and flange 22 to then be withdrawn through the slot 20 of the cage 14 . it is also known that various tools may be utilized for insertion into the slot 20 to engage and move the circular spring 24 thereby permitting removal of the tube 12 from engagement with the spring 24 and cage 14 . the present invention relates to an improved tool for effecting the decoupling or disconnecting operation described . specifically , the tool of the present invention is a single molded tool which is preferably molded from an elastic material such as delrin ® acetal resin , a trademarked product of e . i . du pont de nemours & amp ; co . ( inc .). the tool of the present invention is sized so that each tool is specifically sized and has the capability of being utilized with a specifically sized tube and , in particular each specific size of , larger diameter tube 12 . thus , each disconnect tool of the present invention is custom designed for use with respect to tubes of specific diameter , and a set of such tools would typically be provided for use by a mechanic . the set would include tools useful with a series of standard diameter tubes . the tool of the present invention is comprised of first and second molded cylindrical sections or sectors 40 and 42 . these sectors 40 , 42 are curved to fit against the outside surface of the larger diameter tube 12 and are retained in such a position by an annular , cylindrical , split , elastic collar 44 which is joined to each of the separate sectors 40 , 42 by ribs 46 , 48 , 50 and 52 . the size , construction and configuration of these elements are important features of the invention . referring to fig3 and 4 , the sectors 40 and 42 are substantially identical to each other . the sectors 40 and 42 are sectors or parts of a cylinder having a centerline axis 54 which is coincident with the centerline axis of the collar 44 . each sector 40 and 42 thus has an internal surface 56 with a radius which is substantially the same or slightly greater than the radius of the larger diameter tube 12 over which the particular tool is designed to fit . each of the sectors 40 and 42 also extends circumferentially partially about the tube 12 generally in the range of 90 ° to 160 °, although this extent may be varied . each sector 40 , 42 also includes longitudinal edges 41 , 43 parallel to axis 54 . in the embodiment shown it is noted that it is important that the sectors 40 and 42 are spaced or separated in their normal configuration so that their opposite longitudinal edges 37 , 39 are separated and define a gap or slot 58 along one side of the tool . a larger gap or slot 60 is defined on the opposite side of the tool . the thickness of sectors 40 , 42 permits longitudinal access or sliding into slot 20 . the collar 44 also has an annular cylindrical shape with an internal diameter 62 which is sufficiently large so that the collar 44 is spaced from the sectors 40 and 42 . collar 44 has spaced lateral edges 45 , 47 attached to sectors 40 , 42 by means of ribs 46 and 52 . additional connecting ribs 48 and 50 adjacent , but spaced from ribs 46 , 52 are also provided for structural integrity . it is preferred that the attachment of the collar 44 to the sectors 40 and 42 take place toward the edges 45 , 47 of the collar 44 in order to extend the length of an elastic or living hinge which is , in effect , defined by the collar 44 . that is , the circumferential extent of the collar 44 between the ribs 48 and 50 defines effectively an elastic hinge connecting the sectors 40 and 42 . one of the objects of the design is to maximize the length of this hinge so as to increase useful tool life . thus , the ribs 48 and 50 are preferably spaced from one another by at least 180 ° and preferably a slightly greater amount as depicted in fig3 . it is possible , of course , to place reinforcing ribs more closely between the collar 44 and the sectors 40 and 42 and still be within the scope and spirit of the invention . however , it is most appropriate to have the spacing of ribs be in the vicinity of at least 90 ° in order to extend the length of the hinge defined by the collar 44 . the collar 44 , of course , does not form a total cylinder . there is a gap between the edges or ends 45 , 47 of the collar 44 which , in the embodiment depicted in fig3 is a gap that is wider than the slot 58 . preferably , the gap 60 is defined by surfaces 64 and 66 which intersect at an acute angle with the vertex of the angle positioned inside the outside diameter of the collar 44 . in this manner the surfaces 64 and 66 define wedge shaped or inclined surfaces which facilitate the placement of the tool over the large diameter tube 12 and consequent flexing of the hinge portion of the collar . the collar 44 has a circumferential extent in the range of about 300 °, plus or minus 30 ° to 40 °. in this manner a tool is provided wherein a maximum amount of engagement of sectors 40 and 42 against a circular spring 24 is insured . in the embodiment depicted , there are two ribs 46 and 50 associated with the connection between each sector 40 , 42 and the collar 44 . varying numbers of ribs may be utilized , though two ribs are preferred . it is noted that the tool of the invention may be molded from a single material in a single operation , thus making the manufacture of the tool inexpensive and efficient . fig5 illustrates the manual operation of the tool or , in other words , the manner in which the tool is placed on a tube and then manually pushed against the circular spring 24 . there are variants of the invention which are considered to be within the scope of the following claims . for example , the number of ribs may be varied . the circumferential length of the sectors 40 , 42 as well as the collar 44 may be varied . the number of sectors may be varied , though again the preference is the design which is depicted in the drawings . thus , while there has been set forth that a preferred embodiment of the invention , it is understood that the invention is to be limited only by the following claims and their equivalents .