Patent GB-712624-A (GB)
Title: Improvements in riveting machines
Inventor: WALKER HAROLD STAFFORD
IPC: B21J15/24
Filed: 1951-05-10
Abstract: 712,624. Riveting. BRISTOL AEROPLANE CO., Ltd. Aug. 11, 1952 [May 10, 1951], No. 11055/51. Class 83 (4) A riveting machine for closing rivets by the squeezing method comprises a retractable anvil or dolly 41, Fig. 2, and a riveting head 42 carried by the two arms 11, 12 respectively of a yoke 10 pivoted on a pin 13 mounted on a carriage 14 movable transversely of the pivot axis, means for controlling the transverse and pivotal movement of the yoke such that once initiated by a starting control it proceeds automatically until the anvil axis is normal to the surface of a workpiece 26, Fig. 1, and the anvil surface is spaced from the workpiece a distance substantially equal to its stroke, and means for advancing the anvil and the riveting head towards the workpiece to close the rivet positioned at the riveting station. The pivoting of the yoke is effected by an electric motor 37 through a lead screw 34, and the transverse movement of the carriage, which carries wheels 15 running on rails 16, is effected by an electric motor 33 through a lead screw 31. The anvil and riveting head are mounted on frames 39, 40 respectively which are slidable vertically in unison along the respective yoke arms by an electric motor 45 through lead screws 49. A platform 47 for the machine operator is also moved in unison with the frames by the motor 45 through a flexible cable system 46 which includes counterweights. To control the pivoting and transverse movement of the yoke, a feeler member 58, Fig. 5, carried by the frame 40 adjacent the anvil, is pivoted at 59 to a slide (not shown) movable by a spring parallel with the anvil axis towards the work surface which is engaged by feeler buttons 62. The normalizing operation having been initiated by a manually operated switch, the tilting movement of the feeler member actuates either of electric contacts 64, 65 controlling through relays the pivoting motor 37, and the bodily movement of the feeler member actuates contacts 66 controlling through relays the transverse carriage motor 33. When the yoke is positioned correctly, the operation stops and a red warning light is superseded by a green light and a buzzer is sounded. A red warning light is illuminated if the transverse movement of the yoke fails to be controlled by the feeler. The transverse carriage 14 is mounted on a main carriage 17 movable longitudinally by an electric motor 28 along rails 19. The riveting head and anvil are operated by separate hydraulic rams supplied with pressure liquid through solenoid operated valves controlled by fluid pressure actuated switches whereby once the riveting operation has been initiated by manual control the anvil first advances to the workpiece, the riveting head then advances to close the rivet, and thereafter retracts and finally the anvil retracts. An electrical interlock ensures that the riveting operation cannot commence until the normalizing operation is completed. A spring- loaded sleeve surrounding the heading tool proper presses the parts of the work together before the rivet is closed and this sleeve also controls the thickness of the rivet head. A workpiece such as an aircraft wirig panel 26, Fig. 1, is suspended by straps 27 from a Warren girder 24 carried by a stationary structure 20. When the machine is used for work having a compound curvature the yoke may also be swingable on a vertical pivot this movement being also controlled by the feeler device. The main carriage may be moved longitudinally by pre-selected amounts according to the pitch of the rivets and means may be provided for producing automatically a complete cycle of operation of the machine. The movement of the main carriage 17 may alternately be effected by an electric or hydraulic motor through a lead screw mounted in stationary supports.