| 主权项 |
1. An injector head used in coiled tubing systems comprising:
a. at least two opposed counter-rotating chain loops having a first end and a second end, the chain loops comprising a chain; b. a fixed drive sprocket disposed at the first end of a chain loop and a floating sprocket disposed at the second end of the chain loop; c. a force applied to the floating sprocket disposed at the second end of the chain loop to maintain the chain loop at a desired chain tension; and d. a tension cylinder that automatically maintains the chain loop at the desired chain tension, wherein the tension cylinder further comprises: e. a cylinder head and a cylinder head seal; f. a rod and a rod seal; g. a rod wiper; h. a cylinder barrel; i. a retainer; j. a piston seal; k. a piston and a cylinder, wherein the piston divides the cylinder into at least two chambers, a first chamber and a second chamber, each chamber comprising a piston area, and wherein the piston area is substantially the same in the first and second chambers; and l. a check valve connecting the first and second chambers, wherein the check valve allows fluid and pressure to pass from the first chamber to the second chamber. |
