Patent GB-787782-A (GB)
Title: Apparatus for extruding arcuate objects such as brake linings
IPC: B29C48/07
Filed: 1955-12-06
Abstract: 787,782. Making brake lining blanks &c. HARDIE & CO. PTY., Ltd., J. Dec. 6, 1955 [Dec. 15, 1954], No. 34921/55. Class 87(2). .[Also in Group XXIV] Apparatus for extruding arcuate brake lining blanks, &c., comprises means for forcing stock through a die having two opposite walls which are arcuate in the direction of travel of the stock through the die and concentric, and means for cutting the extruded stock. The stock is fed from a barrel 9, Fig. 1, by a helical screw or other device via a feed duct 10 through a die comprising blocks 11, 12 bolted to a plate 15 and held together by screws 17. The blocks 11 are shown separated in Fig. 8 to illustrate the formation of the extrusion passage between arcuate walls 13, 14 and flat surfaces 19, 20 forming sides of a recess in the block 12. Passages 23 are provided for circulating heating or cooling fluid, e.g. steam or water. On leaving the die the extruded stock moves along a support plate 27 to be guided by a roller 28 to pass between a pair of cutter rollers 32 having radial blades 33, which initially are stationary. The stock then passes between arcuate members 38, 39, and the leading end moves a lever 27 to close a microswitch 72, thereby energizing a solenoid which permits engagement of a clutch so that the cutter rollers 32 are rotated by an electric motor to sever the leading end of the stock. The microswitch 72 is adjustable so that it will close at any angular position of the lever 70 selected in accordance with the desired length of stock to be cut. The clutch comprises a shaft 76, Fig. 6, connected through gearing to the electric motor, and having keyed thereto a sleeve 88 carrying a freely rotatable disc 87. The shaft 37 to be driven is connected to the disc 87 by a coil spring 85 which normally grips the sleeve 88 to couple the shafts 76, 37, but when the disc 87 is prevented from rotating the spring 85 unwinds slightly to enable the sleeve 88 to rotate freely thereby disengaging the clutch. The disc 87 is held stationary when required by a pivoted lever 90, Fig. 5, which is held against a step 92 in the disc periphery by a roller 93 carried by a lever 94 connected to the armature 97 of the solenoid 98. On energization of the latter by the microswitch 72 the roller 93 is pulled away from the lever 90 and the clutch is allowed to engage. On rotation of the shaft 37 the cutter rollers 32 are rotated through gearing (not shown) to sever the stock, the cutter blades being driven at a peripheral speed greater than the linear speed of extrusion so that they accelerate the severed portion into the space between the members 38, 39. A cam 56 on the shaft 37 now engages a follower lever 54 to operate a linkage 53, 52, 45, 44 to move the member 38 outwardly together with the severed portion and the member 39. The lever 70 is thus freed to open the microswitch 72, and a lever 59 connected to the member 39 is moved outwardly and held by the engagement of a foot 65 of a strut 63 with the shaft 37, whilst the member 38 returns to its original position as the cam 56 moves away from the lever 54. The severed portion of stock then falls from between the members 38, 39 on to a conveyer belt 107, or into a container, to be removed. The member 39 is then returned as the foot 65 is carried by the rotating shaft 37 to its original position before the shaft is halted.