GB1349201A - Pneumatic nutrunner with work marking mechanism - Google Patents

Abstract

1349201 Nutrunners CHICAGO PNEUMATIC TOOL CO 3 May 1971 [8 June 1970] 12678/71 Heading B3N A nutrunner includes an air motor 24 drivingly connected through an axially disengageable torque responsive clutch (25) Fig. 2 (not shown) with a spindle having a driving connection with an output shaft 16, the shaft carrying a socket 17, wherein pneumatically operable marking mechanism 40 is housed within the shaft for effecting an indentation upon a bolt 19 and slide valve means 23 is provided that is responsive to disengaging action of the clutch to shut off operating air flow to the motor and divert it to the marking mechanism. In operation the obtaining of a final torque causes the clutch (25) to disengage which in turn causes valve means 23 to shut off air to the motor but also allow air to pass to hose 45 and thus marking mechanism 40. Air enters bore 14 and inlet compartment 85 above the stem 83 of a plunger 58. The plunger is forced gently downward against spring 81 until holding tube 62 limits on stud 19. A marking rod 65 descends with the holding tube, engages the stud and is slidably retracted in the holder to take up lost motion permitted by ball latch 63 and flat 64. This retraction raises anvil 68 to seat its flange 77 against the open end of piston cylinder 67. Air also flows through passage 86 to upper clearance 74, thence through ports 87 to an annular chamber 88 defined by piston 66. Build up of air in chamber 88 forces the piston upwards over an enlarged portion 89 of a guide rod 71 causing static air tapped in space 91 above the piston to be compressed. When side ports 92 in the piston register with chamber 88 air flows through the ports 92 to a recessed interior 93 and acts to drive the piston forcefully downward against anvil 68. Static air trapped below the piston is forced through ports 94, 95 to clearance 75. It then flows through ports 96 to an annulus in communication with vents 98. The compressed air trapped in space 91 aids in forcing the piston downward. The reciprocating cycle of the piston is automatically repeated until the throttle valve 22 is released. A loose fit of marking rod 65 in holding head 59 and tube 62 enables multiple markings to be produced on stud 19.