Patent GB-207597-A (GB)
Title: Improvements relating to apparatus for actuating the tools and accessories used in drilling wells
IPC: E21B1/02
Filed: 1922-08-28
Abstract: 207,597. Streda, J., Gillespie, G. J., and Bence, E. H. Aug. 28, 1922. Bore-hole apparatus.-In a connecting-rod for use between the driving crank and the boring beam and of the kind which is formed with relatively-sliding parts controlled by springs arranged to make both the pull and the thrust resilient, and serving to accelerate the drop of the boring tool, means are provided for adjusting the pressures and displacements of the springs and allowing a slight pivotal displacement between the relatively-sliding parts. The lower part of the rod comprises arms 1, 2 distanced by bolts 3 and tubes 4, and bolted at their upper ends to a striking-plate, and the upper part, which carries the shackle 47 for connection to the boring beam, comprises arms 15, 16 which overlap, and are arranged in planes at right angles to the planes of the arms 1, 2. The lower ends of the arms 15, 16 carry pivot pins 17, 18 respectively engaging beneath saddle pieces 12, 13 bolted to a crosshead 10 formed with guide members 11 sliding on the arms 1, 2. Brackets 20 secured to the arms 1, 2 support the pivot pins in their lowest position. The arms 15, 16 are guided by brackets 22, 23 secured to the arms 1, 2, and are capable of a slight pivotal movement about the axes of the pins 17, 18 between the inner faces of these brackets. This pivotal movement may be eliminated, when so desired, by substituting for the plate 7 a plate formed with lugs bearing against the edges of the arms 15, 16. A square-threaded tube 25 is adjustable in the cross-head 10, and a collar 31, adjustably secured to this tube by a set-screw 30, is provided with lugs 32, 33 guided in longitudinal slots in the arms 1, 2. A rod 27 extending through the tube 25 is screwed into the lower end of this tube to which it may be locked by a nut 29, and carries an adjusting head 28 provided with a sharp edge 45 co-operating with a scale 46 on the arm 2. The rod 27 may thus be adjusted in the tube 25 or, when the nut 29 is in locking position, the tube 25 may be adjusted in the cross-head 10, by turning the head 28. A collar 41, guided on the reduced upper end of the rod 27, forms an abutment between two sets of concentric helical springs, one set 38, 39 bearing through a washer 42 on the upper end of the tube 25, and the other set 36, 37 bearing through a plate 40 on the heads 5, 6 of the arms 1, 2. A pointer 43 on the washer 42 co-operates with a scale 44 on the arm 2 to indicate the position of adjustment of the tube 25. The compression of the springs is limited by the abutment of the upper end of the rod 27 against a stud 40' on the plate 40 and of a shoulder 27<1> of the rod 27 on the collar 41. The upper ends of the arms 15, 16 are connected at 48<1> to lugs on a nut 48 engaging a hollow screw 50 formed with longitudinal slots 53 which are engaged by pins 54 carried by a casing 55. A buffer spring 57, within the casing 55 and the screw 50, bears at its upper end on the head of a screw 51 adjustable within the screw 50. The lower end of the casing 55 carries a rubber or like plug 58 arranged to strike the plate 7 when the connecting-rod is under compression.