Continuous composite rod and methods
A continuous composite fiberglass sucker rod for connection between a pump and a pump drive has a rectangular cross section. End fittings having a rod receiving cavity are connected to the rod ends using a curable adhesive. The rod fitting is maintained in a vertical position with the cavity facing upwardly. The rod end portion is positioned in the cavity with the end at the bottom of the cavity. Curable adhesive is introduced into the cavity. A centralizer bushing is used to maintain alignment of the rod relative to the cavity. A portable heating device receives the fitting and rod end portion and enhances the curing process.
1. A method for attaching an end fitting to a composite sucker rod, the method comprising the steps of:
providing a composite rod of non-round cross section and having an end portion and opposite sides separated a distance in a first direction defining a major dimension of said rod and opposite sides separated a distance in a second direction substantially perpendicular to the first direction defining a minor dimension of said rod wherein said major dimension of said rod is greater than said minor dimension of said rod;
providing an end fitting having an outer cylindrical surface and a cavity open at one end of said fitting having a bottom;
wherein the rod is substantially longer than the depth of the cavity from the open end to the bottom thereof;
said cavity including generally cylindrical tapered surfaces converging toward the open end and defining a series of axially spaced wedges, and a pilot bore at the bottom thereof;
positioning said fitting with said open end facing upwardly;
introducing a curable adhesive into the cavity;
inserting the end of said composite rod into the cavity and disposing said end portion of said rod in the cavity with said rod piloted in said pilot bore at the bottom of said cavity;
providing a centralizer bushing having a cylindrical body;
a partial bore open at one end of said body defined by a cylindrical wall having an internal cylindrical surface, and a bottom surface;
a longitudinal slot extending through said body including said cylindrical wall intersecting said bottom surface;
sliding said centralizer onto said rod such that said rod is disposed in said longitudinal slot;
sliding said centralizer bushing along said rod to position said open end of said end fitting adjacent said bottom surface of said centralizer bushing, and
curing said curable adhesive, wherein the curable adhesive bonds to the composite rods;
removing said centralizer bushing from the end fitting and rod.
2. The method of claim 1 wherein the centering of the composite rod is performed using at least one interior surface disposed within the cavity, said bushing secured to the end connector, and at least one clamping apparatus, or combinations thereof.
3. The method of claim 1 wherein the composite rod is maintained in a vertical orientation while curing the curable adhesive.
4. The method of claim 1 wherein the step of curing the curable adhesive comprises heating, using a heating apparatus, a chemical reaction, ambient energy, or combinations thereof.
5. The method of claim 1 wherein said rod has a rectangular cross section and said cavity is sized to receive said rod.
6. The method of claim 1 wherein said centering includes providing a centralizer bushing removably secured to said fitting, surrounding said cavity opening and supporting said rod.