| 摘要 |
961,258. Folding edges of non-metallic sheet material. REECE FOLDING MACHINE CO. Aug. 24, 1962 [Sept. 8, 1961], No. 32711/62. Heading B5K. [Also in Division B6] Apparatus for making book covers (see Division B6) consisting of a flexible cover sheet and one or more stiff cover boards, wherein the cover sheet and/or cover boards are pre-treated with a heat sensitive adhesive, comprises a pad 20, Fig. 1, on which the cover sheet is supported, a die 40 adapted to carry the cover board and movable to position the cover board on the cover sheet, and folder blades 24 movable upwardly and inwardly to fold the marginal edges of the cover sheet inwardly about the die and finally downwardly to press said edges into adhesive contact with the cover board after contracting the die. The book cover is removed from the pad by a suction device and deposited on a heated pressing device, Fig. 25, which presses the remainder of the cover sheet into adhesive contact with the cover board to ensure a smooth finish. The cover sheet and the cover board are placed on the pad 20 and the die 40, respectively, by hand. The cover sheet is placed on the pad 20 with its marginal edges overlying folder blades 24 and abutting stop plates 21, which locate the cover accurately in position. The stop plates 21 are attached to a rectangular frame supported on front and back crossbars 32. Four folder blades 24 are slidably mounted beneath the stop plates, each folder blade being fastened to a block 25. Each block 25 is attached to a rod 30 slidable in a groove in the corresponding crossbar. By means of suitable linkage controlled by cam operated means, the crossbars 32 are lifted, whereby the folder blades bend the marginal edges of the cover sheet upwards about the edges of the die, and are then moved towards each other, so that the front and back marginal edges of the cover sheet are folded over the die. Next, the two front and the two back rods 30 are moved towards each other to fold the side marginal edges of the cover sheet over the die. The order of folding the marginal edges of the cover sheet may be reversed or the two movements carried out simultaneously. The adjoining edges of the folder blades overlap and are thinned in these regions 76-79, to permit relative movement, Fig. 3A. The die head 35 is pivotally mounted on a shaft 36 and carries four co-operating die plates 40 forming a rectangular frame, the adjoining edges of the die plates being thinned to permit expansion and contraction of the frame. The die plates are mounted on shoes 270-273, Fig. 11, slidable in slots 276-279 in the base plates 280, 281 of the die head and are interconnected by pivoted levers 274, 275 secured to links 268, 269 fastened to a block 267. The die plates are adjusted to form a frame equal in size to the cover board by means of a screw 70, passing through one end of a rectangular frame 261-264 and the block 267. The rectangular frame 261-264 is moved by links 258, 259 to pivot the levers 274, 275 and expand or contract the die. In use, a cover board is held on the frame by suction ports 43, 44 and the die head pivoted by cam operated means to place the cover board on the cover sheet. After folding the marginal edges of the cover sheet about the edges of the die, the die plates are retracted simultaneously by pivoting the levers 274, 275, to disengage said folded over marginal edges and the folder blades descend to press said marginal edges into adhe. sive contact with the cover board. Electrical heaters are provided beneath the pad 20 to activate the adhesive. The die head and folder blades return to their initial positions and the partially finished cover is transferred to a pressing unit, by suction pads carried by an oscillating arm, Fig. 9 (not shown). The folder blades shown in Fig. 3A form square corners. Alternatively, the folder blades are shaped to form round corners, Fig. 3B (not shown), and in this case, spring loaded spatular shaped blades 405, Fig. 38, are mounted on the upper surface of the die 40, one at each corner, to tension the cover sheet as it is folded, to ensure a smooth finish. Each blade 405 loosely engages an upstanding screw 407 and rests on a nut 408. Hence, the spatular is normally inclined downwardly by the spring 409.
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