Patent GB-920048-A (GB)
Title: New and improved apparatus for punching slat assemblies
IPC: B21D28/32
Filed: 1961-10-25
Abstract: 920,048. Making window blinds; sheet metal Joints. HUNTER DOUGLAS INTERNATIONAL (QUEBEC) Ltd. Oct. 25, 1961 [Oct. 28, 1960], No. 38272/61. Classes 83 (2) and 83 (4). Apparatus for punching rolled-edge joints of slat assemblies used for awnings, screens, blinds, doors or the like comprises a punchmounting frame adapted to be moved transversely across the slat assembly and having an engagement member for engaging contact portions of the slats, a punch mounted on the frame and adapted to occupy a punching position adjacent a slat joint when the engagement member is engaged with a contact portion of a slat, and means for actuating the punch when it is in a punching position so that the adjacent slat joint will be punched to form depressions or perforations. The slat assembly 12 is supported on a table 10. Each slat 13 has one edge 15 rolled in the direction of curvature of the body of the slat and the other edge 16 is oppositely rolled. The end of the slat assembly lies on a strip 17 attached to the table and the ends of the slats are aligned by an edge retaining bar 18, Fig. 2. The punch mounting frame 22 is slidably and pivotably mounted on a guide rod 21. A weighted block 26 holds the frame arm 24 over the strip 17 and a handle 28 is used to pivot the frame and a handle 30 to move the frame along the rod 21. A spring-loaded solenoid 32, 33 is mounted on the frame for actuating a punch 42 mounted in a block 40 (Fig. 4). Fixed to the upper end of the punch is a spring-loaded yoke member 44. On the inner side of the block 40 is pivoted a spring-loaded trip-mounting block 52 having a spring-loaded triprod 53 for actuating a microswitch 63 which controls the solenoid 32. The microswitch is adjustably mounted on the punch mounting frame. A slide shoe 67 adjustably secured to the frame arm 24 is adapted to ride across the slat joints so that the latter may support the punch mounting frame during sliding movement. A roller 69 on the frame arm engages the bar 18 and supports the mounting frame when there is no slat assembly on the table. In operation, the slat assembly is aligned on the table and the rear edge of the rearmost slat is hooked over a fixed hook strip 71 secured to the mounting strip 17. At spaced positions along the near edge of the table adjustably-positioned hook strips 72 engage the slat edge. The front edge of the foremost slat is gripped by a hook member 76 adjustably mounted on the guide rod 21. A knob 75 on the hook member is used to stretch the slat assembly to the desired tautness of the joints. The punch-mounting frame 22 is drawn forward by the hand knob 30 until the trip rod 53 and punch 42 pass the first or rearmost edge and the shoe 67 is in contact with the slat joints. When the trip rod 53 engages the first joint the microswitch 63 is depressed and the solenoid 32 is actuated to strike the punch 42 which in turn strikes the joint between the slats. As the punch and the attached yoke 44 move downwardly a clearance screw 50 on the yoke strikes the trip-mounting block 52 and disengages the trip rod 53 from the micro-switch and so de-energizes the solenoid 32 whereupon the punch returns to its initial position. This sequence of operations is repeated for each joint as the punch mounting frame is drawn across the slat assembly. The opposite end of the slat assembly is similarly punched by identical apparatus mounted at that end of the table. Slat assemblies punched in this manner may be provided with locking rivets.