Patent GB-191308253-A (GB)
Title: An Improved Machine for Making Paper Bags.
Inventor: SINCLAIR WILLIAM GARDNER
IPC: B31B29/00
Filed: 1913-04-08
Granted: 1914-03-12
Abstract: 8253. Sinclair, W. G. Nov. 6, 1912, [Convention date]. Paper bags, making. -A machine for making paper bags with square or hexagonal bottoms has two sets of pasting and folding devices arranged at fixed points around two plates or drums rotating on horizontal axles, one drum being provided with devices for forming paper blanks into tucked tubes, and the other drum with devices for folding the ends of the tubes. On the first drum A, Figs. 1 and 2, the blanks are formed into tubes by means of the apparatus described in Specification 8254/13. A gummed paper blank a is folded around the former-plates 9, 10 by means of plates 22 which are rotated about their inner edges and fold the paper under the former-plates. A similar set of folding- plates may be used to fold a lining-paper around the former-plates before the outer blank is applied. The drum is intermittently rotated, and by the time a blank has arrived at position c, Fig. 2, the tube has been creased and flattened as described in the earlier Specification. The tucked tube thus formed is conveyed bv the drum to the position d, where it is seized by reciprocating nippers and drawn on to the drum B which conveys it past various folding - devices secured to the frames. This drum consists of a series of radial arms carrying at their ends plates 48, Fig. 22, against which the paper tubes are held by means of spring-pressed gripping-frames 49 operated by a cam 52. The tube is next conveyed to the folders at position g where the side tucks are entered by two pairs of V-shaped folding-plates 55, 56, Figs. 15, 16, and 22. One folder 55 of each pair is fixed to its slide, and the other 56 is hinged at 57 to the fixed blade. The blades 56 are rotated, thus opening out the end of the tube into box form, as shown in Fig. 16. The formation of the box is completed by a square mandrel 72 consisting of four elastic blades 68 the lower ends of which are curved and the upper ends of which are attached to plate 70 fixed to a reciprocating plunger. The mandrel enters the box, and when it has reached the lower limit of its travel, a square plunger 74 inside the blades, moves down and expands their curved lower ends, thus forming the side and bottom creases of the box. After the withdrawal of the mandrel and the folding-blades, the tube is moved to the position h where one side of the box end is gummed by an oscillating roller 98, Fig. 22, and a card for reinforcing the bottom of the bag is inserted in the box. This is done by means of a mandrel similar to 72 in which one of the flexible blades 106, Fig. 1, has a slot 107 through which a card is pushed from the lower end of a pile n by means of a reciprocating pusher 104. When the mandrel descends into the box, the inner plunger 113 pushes the card past the blades 106 and deposits it in the box. At position i, Fig. 22, the sides of the box are folded down on to its bottom by means of blades 118, 119, Figs. 18 and 19, which are moved down to the position shown. A blade 130 is first inserted a little way into the mouth of the box to push out the sides of the box and to start the folds as shown in dotted lines in Fig. 18. The blades 118, 119 are then rotated about their pivots and fold the sides of the box down into the form shown in Fig. 19, the blade 118 moving a little in advance of the other so that the gummed portion is covered by the other side of the box. The blades are removed and the bag brought to position j, Fig. 22, receiving on its way gum from a rotating gummer 151. At position j, a plate 172, Fig. 20, is pressed against the bottom of the bag and folding plates 156 are then moved under the projecting end and rotated in the direction shown by the arrows. The plate 172 is removed during the movement so that the blades fold the ends down on to the gummed portion of the bag, completing the bottom as shown in Fig. 21. The finished bag is next removed by reciprocating nippers and deposited on a conveyer band 54, Fig. 2, which carries it under a presser apron 193. A counting-arm 194 is oscillated at predetermined periods to change the position of a bag on the band 54 in order to assist the counting of the finished bags. In order to assist the folding, the bag, when it is drawn on to the drum B at position d, Fig. 2, may be pressed by a plunger having on its surface a series of grooves or ribs which form grooves on the tube corresponding to the folds to be made. In the Specification as open to inspection under Section 91 (3) (a) it is stated that the machine may be adapted for making bags with hexagonal bottoms; this subject-matter does not appear in the Specification as accepted.