PIPE RACKER

1456631 Boring earth &c LEE C MOORE CORP 27 Feb 1975 [14 June 1974] 8212/75 Heading E1F A pipe racker includes pairs of laterally spaced trays 5 for horizontally supporting pipe stands at one side of a transfer zone, means for indexing the trays 5 lengthwise across the transfer zone, transfer means for moving each successive pipe stand to locate its leading end at an elevating position in an oil well derrick 2, and a steady arm 32 which engages each lifted pipe stand and swings upwardly and over to control the trailing end of each pipe stand as it is being elevated. As described the apparatus includes two sets of trays 5 slidably mounted on top of each other, the bottom tray 5 being slidable on rails 8. The trays 5 are indexed across the transfer zone by a piston and cylinder device 16 (Fig. 5), the piston rod 17 of which is fixed to a tray 5 and the cylinder 16 of which carries a ratchet block 19 having a notch 21 which engages the rear walls of successive recesses 6 in the tray 5 below (the ratchet block 19 engaging recesses 9 in rail 8 when the bottom tray 5 is being indexed). The trays 5 are supported on the opposite side of the transfer zone by a rack 13, and can be moved out of the rack 13 when replacing pipe stands in the trays 5 by reversing the ratchet block 19. Each successive pipe stand is moved from the transfer zone to a position in which its leading end is above the well (as shown in Fig. 2) by a pair of parallel transfer arms 23 carrying pipe engaging shoes 25. The transfer arms 23 are connected together by link 26 and are operated by ram 27. An elevator 29 carried by travelling block 30 is then connected to the leading end of the pipe stand which is then raised in the derrick 2. During the raising of the pipe stand a grooved wheel 34 on the steady arm 32 engages the bottom of the pipe-stand and the steady arm 32 is swung upwardly and over to control the trailing end of the pipe stand. The arm 32 is moved by means of a sprocket 36 fixed to support 33 (Fig. 10), a rotatable sprocket 37 mounted on the arm 32 and a chain 38 fixed to the piston rods 39 of a double acting piston 40 and cylinder 41. The pipe engaging wheel 34 is mounted on a bracket (not shown) pivoted to the end of the arm 32 and can be disengaged from the pipe stand to allow the arm 32 to return by means of piston and cylinder 44.