GB943917A - Improvements in or relating to bending machines - Google Patents

Abstract

943,917. Angular bending. HILMOR Ltd., and E. J. HAMPSON. Feb. 24, 1961 [Feb. 26, 1960], No. 6809/60. Heading B3E. A bending machine of the kind including a bending head arranged to carry out bending movements, a member movable in dependence upon movement of the bending head and a switch arranged to be operated to stop bending movement on inter-engagement of a first abutment and any one of a number of second abutments carried by an abutment carrier, and means to move the abutment carrier stepwise after each bending movement to bring each of the second abutments in turn into line with the first abutment, the first abutment and the abutment carrier being moved towards one another by movement of the movable member resulting from a bending movement of the bending head, is characterized by the provision of spring means to return the abutment carrier to an initial position after a selected number of bending movements have been made. In operation, the number of successive bending movements to be made is selected by inserting a pin 51 on a disc 39 into an appropriate one of a series of bores 49, equally spaced on a circle in a ratchet wheel 42. The first bending movement is then commenced, e.g. the rotation of a bending former around which a tube is bent. The bending head rotates, through chain and sprocket means, threaded shafts 12 and 14. A nut 31 on the shaft 12 is thus moved axially until a stop 34 on an arm 32 thereon abuts an appropriate stop 29 on a carrier 27 on a shaft 28, 23 and moves the carrier and shaft until a cross-piece 25 on the shaft end operates a switch 19 to stop the bending operation. During this movement a nut 66 threaded on the shaft 14 moves axially to allow a spring 65 to move a pawl 63 and connecting rod 64 to the right so that the pawl passes under the lowermost tooth of the ratchet wheel 42, thereafter relative movement occurs between the rod 64 and nut 66. On operation of an appropriate switch the bending head returns to its initial position, the nut 31 moving back until a stop 33 on the arm 32 operates a switch 19A to stop the machine drive and the nut 66 moves back so that the pawl 63 rotates the ratchet wheel 42 one step and thus, through disc 39, shaft 37 and bevel gears 36, 35, turns the carrier 27 one step. A main pawl 44 holds the ratchet wheel 42 in position against the action of a spiral spring 41 on the shaft 37. The cycle of bending movements is repeated until a fixed pin 50 on the ratchet wheel 42 engages a member 48, Fig. 5 (riot shown), to lift the main pawl 44 from engagement with the ratchet wheel 42 and allow the spring 41 to return the wheel 42, disc 39 and carrier 27 to their original positions, the pin 51 moving the member 48 to allow the pawl 44 to stop the ratchet wheel 42. Specification 943,918 is referred to.