Patent GB-212959-A (GB)
Title: Improvements in machines for use in the double seaming of sheet metal
IPC: B21D51/32
Filed: 1922-11-21
Abstract: 212,959. Crabtree, W. A. Nov. 21, 1022. Seaming; beading. - A machine for double-seaming or beading &c. cans &c. has seaming - roller carrying-levers mounted on secondary levers which are actuated by cam mechanism so that work of irregular cross section may be dealt with, the centre of oscillation of each secondary lever being substantially coincident with the point of actuation of the seaming-roller lever carried thereon. Machines for seaming both end-walls simultaneously or for seaming only one end-wall are described. The work is mounted between chucks 12, 12<a>, Fig. 1, carried by spindles mounted in slides 11 the lower of which is vertically adjustable, but fixed, the upper being moved down after the work has been positioned. The chuck spindles are driven through gearing 22 by a shaft 19 which mav be clutched to a belt-driven pulley 18. The pulley 18 may be moved axially by linkage 40, 39, 37, 44 and is normally held in the upper, disengaged position by a pivoted detent 45, a brake 43 controlled by linkage 41, 42 being simultaneously applied to prevent rotation of the shaft 19. The upper and lower pairs of seaming-rollers are carried by levers 2, Fig. 2, which are controlled by cams 6 driven through spur gearing from the shaft 32, and are pivoted on levers 4 themselves pivoted on the cam-shafts 7 and controlled by cams 9 of the same contour as the work and chucks. The shaft 32 is driven by bevel gearing from a cross shaft 29 which carries a cam 36 for disengaging the pulley 18 and receives motion through worm gearing from a shaft 25. The latter is driven frictionally by a belt-driven pulley 24 which is controlled axially by a bell-crank lever 47a and a spring 52. The bell-crank lever is linked to a trip mechanism comprising a lever 49 and a detent 50 coacting with a stop 53 on a pedal-actuated rod 46. A stud 54 on the link 49 carries a flanged spring-pressed roller 55, Fig. 8, which coacts with a spiral scroll cam 57 on the shaft 32. The work having been positioned on the lower chuck, the pedal 47 is depressed, thereby elevating the lever 49 by the detent 50 and allowing the roller 55 to move to the inner radius of the spiral scroll cam, where the acting surface of the cam is lower. The upward movement of the rod 46 also trips the detent 45 and thereby takes the weight of the upper chuck slide. On release of the pedal, the upper chuck slide descends to hold the work, the chuck spindle and cam driving motions being simultaneously automatically engaged owing respectively to the descent of the rod 44 and the release by the stop 53 of the lever 49. The machine is automatically stopped by the cam 36 disengaging the chuckspindle driving gear, and by the cam 57 elevating the rod 48 and disengaging the cam driving gear. In a modified form of machine in which' only one end wall is seamed, the seaming-roller levers 2, Fig. 12, are brought into action by linkage 6<a>, 58 actuated by the starting pedal 47, Fig. 10. The pedal also actuates a link 72 which rocks an arm 71 thereby depressing the upper chuck 10<a> into contact with the work. Simultaneously with this movement, a belt fork 40a throws the driving-belt on to a fast pulley 18 carried by a shaft 19 which is geared to the chuck spindles. The pedal actuation of the link 72 moves an arm 75 out of engagement with a catch 78, Fig. 13, secured to a cam 79 loosely mounted on a fixed pivot, and the cam thereupon rotates, either by spring actuation or as a result of being unbalanced, till a friction wheel 77 carried in the arm 75 and positively driven through gearing by the guide pulley 83 is urged into contact with and drives the cam. The automatic subsequent operation of the arms 71 and 40<a> to separate the chucks, apply a brake 74<a>, and throw the belt on to the loose pulley to stop the machine, is effected by the rotation of the frictionally-driven cam 79.