BUMPER ASSEMBLY HAVING PROGRESSIVE RATE SPRING
A bumper assembly for down-hole use in a well. In one embodiment, the bumper assembly includes a fish neck, a cage, and a progressive rate spring disposed there-between. When a plunger strikes the top of the fish neck, the progressive rate spring dampens the force delivered by the plunger, thereby prolonging the useful life of the plunger and/or the bumper assembly.
1 . A bumper assembly, comprising:
(a) a first end;
(b) a second end; and
(c) a progressive rate spring disposed between said first and said second end.
2 . The bumper assembly of claim 1 further comprising a pull rod attached to said first end and engaged with said second end.
3 . The bumper assembly of claim 2 wherein the pull rod is slideably engaged with said second end.
4 . The bumper assembly of claim 3 wherein at least a portion of said pull rod is enclosed by said progressive rate spring.
5 . The bumper assembly of claim 4 wherein said first end includes a fish neck.
6 . The bumper assembly of claim 5 wherein said second end includes a cage.
7 . The bumper assembly of claim 6 wherein a portion of the second end is attached to a well pipe.
8 . The bumper assembly of claim 7 wherein said cage includes a device for dampening a force delivered to said device by said pull rod.
9 . The bumper assembly of claim 8 wherein said device for dampening comprises a Belleville washer.
10 . A bumper assembly for use down-hole in a well, comprising:
(a) a fish neck;
(b) a cage; and
(c) a progressive rate spring disposed between said fish neck and said cage.
11 . The bumper assembly of claim 10 further comprising an extension for attaching to the cage, where said extension also attaches to a well pipe or the bottom of the well.
12 . The bumper assembly of claim 11 further comprising a pull rod attached to said fish neck and engaged with said cage.
13 . The bumper assembly of claim 12 wherein the pull rod is slideably engaged with said cage.
14 . The bumper assembly of claim 13 wherein at least a portion of said pull rod is enclosed by said progressive rate spring.
15 . The bumper assembly of claim 14 wherein said cage includes a device for dampening a force delivered to said device by said pull rod.
16 . The bumper assembly of claim 15 wherein said device for dampening comprises a Belleville washer.