Patent GB-278247-A (GB)
Title: Improvements in machines for making boxes
IPC: B27M3/34
Filed: 1927-03-07
Abstract: 278,247. Burnham, C. March 7, 1927. Binding and covering; bending-formers. - Relates to machines for making punnets comprising two crossed strips of veneer, of which the four projecting ends are turned up and secured together to form the walls, and for folding thin metal strips of channeled section into rectangular form to engage the upturned ends of the veneer strips and securing the metal strips thereon. The channeled strips 44 are fed lengthwise into grooves in members 37, 36, which are mounted upon a reciprocating carriage 20, the outer members 37 being pivoted to the central member 36 so that when in the forward movement of the carriage. 20 members 41 on the members 37 engage stops 43 arranged at the corners of the punnet former 154 the members 37 are swung round to bend the strip about a rectangular anvil 80 carried upon the former. The members 37 are connected to the carriage 20 by levers 39 which are urged towards one another by a spring 39<1>, and to permit of lost motion of the member 36 it is secured to the carriage by a spring 84 arranged in a, cylinder 81. At this stage, folding members 86, 87, Fig. 11 engage the projecting portions of the strip and bend them towards one another to form the fourth side of the rectangle. The folding members 86, 87 are of toggle form and are pivotally mounted upon shoes 105 slidablv mounted in blocks 107 which are vertically movable so that the members 86, 87 may be lowered out of the way when the carriage 20 is advancing, and in the forward movement of the shoes 106 abutment members 43<1> on the folders 86, 87 engage the stops 43 and act as pivots for the folders. One member 87 engages in its forward movement a cam surface 131 and is depressed thereby so as to place the end of the strip engaged thereby beneath the end engaged by the member 86, the two ends being placed under spring-held, pivoted hooks 100, 102 which hold the strip in position on the anvil 80 when the folding members are withdrawn. In addition to the hooks 100, 102 corner anvils radially slidable in the former head 154 are provided to hold the channeled strip upon the anvil. The veneer strips 151 are delivered to a position beneath the former by a rotary carrier 150 and are pressed upwardly against the. former 154 by a plunger 153, Fig. 14, having folder wings 156. Spring-held lips 159 upon the wings 156 allow for slight variations in the thickness of the veneer strips so that the turned-up ends thereof may be accurately positioned within the channeled strip 44 which is held against the anvil 80. The crimping of the strips 44 in position on the upturned ends of the veneer strips is now performed by jaws 167 carried by toggle levers 177. 178 actuated by a member 175 from a sleeve 173 slidingly mounted upon the former post 155 and actuated in the usual manner from the main shaft. A presser foot 161 slidingly mounted within the former head serves to clamp the strips 151 upon the rising plunger while the folder wings 156 are acting and also carries the usual spring-actuated ejector 162 which strips the completed punnet from the former on to spring-pressed forked fingers 168 which are pivotally mounted on the carrier 150. To retain the channeled strip 44 in the grooves in the members 36, 37 during the forward stroke of the carriage 20 spring controlled catches are pivoted upon the members 37, while to close the grooves during the passage therein of the strip a shutter device 47, Fig. 2, is provided, pivoted upon a shaft 61 and operated by rods 57, 58, 68, 73 and spring 72. The carriage 20 is reciprocated by a cam 22 and rocking leyer 23 from the main shaft, the lever 23 being resiliently connected to the carriage by means of rubber or other buffers 25, and the carriage is further cushioned in its return stroke by dash pots 27. The shoes 106 carrying the folding members 86, 87 are moved towards and from the former by rods 114 independently actuated by levers 116, 121 and rods 120, 124 from cams on the main shaft, and the blocks 107 are moved vertically by the engagement of racks ' 108 carried thereby with pinions 109, Fig 14, upon a rocking-shaft 110 actuated by a rod 112, an adjustable coupling 110<11> being provided on the shaft 110 to permit relative vertical adjustment of the positions of the blocks 107.