GB1392637A - Plastics extrusion cutting-off machines - Google Patents

Abstract

1392637 Parting-off machine; beds and frames SPEEDEX ENG Ltd 21 Nov 1973 [11 Dec 1972] 57112/72 Headings B3T and B3B [Also in Divisions B4-B5] A parting-off machine comprises a carriage 5, a rotary cutter head 12 mounted on the carriage, at least one cutting tool 55 carried by head 12, and adapted to be intermittently moved radially relative to the workpiece by a cam and follower 23, 66-69, when there is relative rotation between said cam and said head 12. Carriage 5 has a pair of clamps 7, 8 actuated by pneumatic rams 9, 10, so as to clamp the workpiece which is received from a plastics extrusion line into a core tube 11. The carriage is movable on rails 4 carried by a frame 1 which is moved on castors 2 and supported in the required position by retractable feet 3. Cutter head 12 is mounted for rotation on tube 11 and after clamping of the workpiece, carriage 5 is moved along the frame with the cutter head rotating around the extrusion. Cam 23 has notches 32 and a plunger 29 carried by a toothed pulley 28 is adapted to engage a notch and drive the cam in one direction only. A second cam 22 also has notches 27 which are engaged by a plunger 24, slidably mounted in a sleeve 16 driven by a second toothed pulley 19. The latter is driven by a toothed belt 33 from a toothed pulley 34 driven by an electric motor 38. Pulley 28 is driven by motor 38 via a toothed belt 39 through idler rollers 41-44, and 45, 46, rollers 45, 46 being mounted on a sub-carriage 47 movable along a rail 48 by a pneumatic ram (52) Fig. 3 (not shown). A parting-off tool 55 is located on flange 17 of sleeve 16, and the flange also supports a chamfering tool radially movable by cam 22 which actuates a second follower assembly 66- 71. In operation, the extruded material passes into bore 11 and is clamped by clamps 7, 8. There is no relative rotation between pulleys 19, 28, and the tools rotate around the workpiece without any radial movement. To cause the tools to move radially so that the workpiece is firstly chamfered and then parted-off, subcarriage 47 is moved to the right Fig. 2, by rams (52, 53), Fig. 3 (not shown), so that belt 39 is accelerated and pulley 28 is driven faster than pulley 19, whereupon cams 22, 23, and bush 20 are driven in the anticlockwise direction relative to sleeve 12, plunger 24 rides out of notch 27, lobes on cams 22, 23, actuate followers 69 and the tools are moved radially. The cam lobes are so arranged that the chamfering tool acts before the parting-off tool. The belt drives may be replaced by a common motor, or separate motors which drive through clutches and gearing. Ram 52 may have an hydraulic dashpot.