DETAILED DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a prior art adjustable swage in its smaller dimension;
FIGS. 2
a-2c are a prior art section view of the adjustable swage in the FIG. 1 position;
FIGS. 3
a-3c are the view of FIGS. 2a-2c but in the maximum dimension for the adjustable swage;
FIG. 4 shows the prior art adjustable swage in its maximum dimension;
FIG. 5 is a perspective view of the present invention during normal operation;
FIG. 6 is the view of FIG. 5 showing what happens when the adjustable swage reaches an obstruction;
FIG. 7 shows a single segment of the adjustable swage during normal operation;
FIG. 8 is the view of FIG. 7 when an obstruction in the tubular to be expanded is encountered;
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 5 shows wedge segments 20 and 22 oriented in the same direction with segment 24 going the other way. The layout of the segments and how they are joined together is identical to the view in FIG. 1 and the basic operation of the adjustable swage discussed above will not be repeated. What is unique about the arrangement will now be reviewed.
Segments 20 and 22 and the other similarly situated segments that are not shown preferably have a flexible flange 26 spaced apart from base surface 28. Retainer 30 has an inner recess 32 that holds a guide flange 34 that is part of the segment 20 or 22 or the other similarly situated segments that are not shown. Retainer 30 has a bearing surface 36 that contacts surface 38 on flexible flange 26. Surface 38 is part of an inwardly oriented ring 40 that defines circular recess 32. The connection arrangement for the oppositely oriented segments is substantially the same with ring 42 having a bearing surface 44 to contact surface 46 on flexible flange 48 on segment 24 and the others that are similarly oriented and not shown.
When the segments that make up the adjustable swage hit an obstruction the contact location is still on steep surface 50 as shown in FIG. 7. When the segments hit the obstruction at surface 50 the applied force increases from retainer 30. This creates a reaction force similar to what was shown in FIG. 5. As before, the radial component 52 is quite small when compared to the longitudinal component 54. As before in FIG. 5, it is the radial component that drives the segments in the adjustable swage to go to a smaller diameter by moving them relatively along their inclined dovetail connection to essentially advance the fixed swage 134 that has already cleared the obstruction. Here again, if the generated radial component was sufficiently small the adjustable swage segments would not move relatively to each other because the generated force would not be strong enough to advance the fixed swage 134 to allow the peaks 154 and 160 the ability to separate. The adjustable swage would simply stall at the obstruction.
The present invention addresses this situation as the loading increases when an obstruction is hit. FIG. 8 shows that ring 40 has bent elastically toward recess 32 thus placing the loading surface 36 on an incline where the mating surface 38 has the same angle because of the way the surfaces engage each other and the way they are each supported. Now a loading force delivered through ring 40 and represented by arrow 56 results in skewing the contact axis between surfaces 36 and 38 by angle a in FIG. 6. As a result of such surface skewing a radial component of force is generated as indicated by arrow 56. This radial load is over and above the radial load generated by the direct contact of the segments with the obstruction as illustrated in FIG. 5. As a result the adjustable swage is now more likely to clear an obstruction rather than stall due to the additional radial collapse force provided.
Those skilled in the art will appreciate that both ends can have the same treatment to create a radial component force at both ends even though only one end has been described. While the creation of the additional radial force has been accomplished with bending load surfaces other ways to create a radial force when an obstruction is hit are also within the scope of the invention. In the preferred embodiment the additional radial force is not created until an obstruction is hit so that in normal expansion operation the operation of the adjustable swage described is similar to the prior art operation. In that sense a radial collapsing force is not created during normal operations when it is not needed. Rather, it is when an obstruction is encountered and the adjustable swage needs to get smaller in diameter to get past that obstruction that the bending takes place and the collapse force comes into play to get the adjustable swage past the obstruction.
Additionally, the size of gap 58 adjacent flexible flange 26 is sized such that even when flange 26 closes gap 58, the bending is still in the elastic range.
The above description is illustrative of the preferred embodiment and many modifications may be made by those skilled in the art without departing from the invention whose scope is to be determined from the literal and equivalent scope of the claims below.
Patent Application
20070277971
