Tray-folding machine.

Application filed May 27,1905. Serial No. 262,638.

Patented Sept. 4, 1906.

To all whom, it may concern:

Be it known that we, John Hays Birgit and John Henry Birch, citizens of the United States, residing at Crawfordsville, in 5 the county of Montgomery and State of Indiana, have invented certain new and useful Improvements in Tray-Folding Machines, of which the following is a specification.

The object of our invention is to produce io a folding means by which the box-trays may be folded at a single operation, the construction being such as to insure accuracy and squareness of fold, so that the sides of the tray will not bulge.

The accompanying drawings illustrate our invention.

Figure 1 is a central vertical section of our tray-forming mechanism in connection with a drying-wheel by means of which the folded 20 trays may be held until the glue is sufficiently .set.. Fig. 2 is a plan of the parts shown m F>g. 1; Fig, 3. a perspective detail of a folding-lever and a part of its holder; Fig. 4, a perspective view of the folding25 lever, and Fig. 5 is a plan of the blank from which the tray is formed.

In the drawings, 10 10 indicate a pair of blocks which have formed in their adjacent faces vertical pockets 11 11, in each of which 30 is pivoted a folding-lever 12. Each of said folding-levers is provided with an operatingarm 13, which lies below the axis of the lever, and a pair of folding-fihgers 14 14, which are carried by the lever 12 at its ends.

Fitted in.each pocket 11 on top of the contained folding-lever 12 is a yielding block or plate 15, the middle portion of which fills the space between the fingers 14 of the foldinglever. The block 15 is provided at its ends 40 with projections 15', which project over the fingers 14, and its upper face is held even with the upper face of the block 10, in which it is mounted. The blocks 15 are each supported by suitable guide-rods 16 and are urged in45 ward into alinement with the vertical inner face of the containing block 10 by means of suitable springs 17. Each folding-lever is normally held in the position indicated in Fig. 1 by means of a spring-plunger 18. The 5c distance between the adjacent vertical faces of the two blocks 15 is substantially equal to the external transverse dimension of the boxtray to be formed, and cooperating with the opening between these two blocks is a form- ] ! ing-plunger 20, the transverse dimension of 55 which is equal to the distance between the adjacent faces of the block .15, less approximately double the thickness of the material to be operated upon, and the longitudinal dimension of which is. equal to the distance 60 between the adjacent faces of the two fingers 14, less twice the thickness of the material operated on.

In operation the tray-blanks 30 are formed in any desired manner—such, for 65 instance, by the machine described and claimed in our pending application, Serial No. 2.30,378. Each of these tray-blanks consists of a main body portion B, which forms the. bottom of the tray, end flaps e, upon 70 which are placed glue marks g, and sides s, wliich terminate in side flaps s'. These blanks are fed to the space above the blocks 15 in any desired manner in succession beneath suitable guides 21, and as the plunger 75 20 descends the sides s are turned up by a downward movement of the plunger between the blocks 15, so as to lie between the sides of the plunger and the adjacent blocks 15, said blocks yielding to compensate for any 80 variation in thickness of the material of the blank, but. at all times holding the sides s tightly against the plunger, so that the said sides are hold straight and given no opportunity to buckle. The plunger descends 85 until the bottom B of the tray is brought into, engagement with the arms 13 of the folding-lever 12, whereupon further downward movement of the plunger causes the folding-levers to turn on their'axes, and thus 90 project the folding-fingers 14 across the ends of the plunger 20, so as to fold the extended flaps s' toward each other around the ends of the. plunger. This operation takes place while the sides s are being held against 95 buckle between the plunger and the blocks 13, so that a sharp square bend is made between the sides s and the flaps s'. Further downward movement of the plunger brings its ends between the spring-pressed rollers 100 22, which thus operate to fold the end flaps e up and press them against the inturned flaps s', the glue strips g holding the parts in folded position. The formed tray is moving downward relative to the fingers 14 when the end 105 flap, e is being turned up, and in order to avoid gumming up the outside faces oi the fingers 14 by the glue strips g the outer faces ο

830,204 of said fingers 14 are undercut, as at 14', so that the glue strips g will not come into contact with the fingers as the blank is forced downward between the spring-pressed rollers

22. The plunger continues downward between the arms 13 of the folding-levers 12 and forces the tray into a radial pocket 25 formed in the drying-wheel, and as the formed tray passes down beyond the fingers io 13 they are moved inward slightly by the plungers 18, so as to form stripping-fingers to prevent the upward movement, of the formed tray when the plunger 20 is withdrawn. The plunger 20 moves downward 15 until the formed tray is entirely inserted into the pocket 25, and in order to facilitate the introduction of the formed trays into the drying-wheel we have found it desirable to provide the ends of each pocket with air20 channels 27', which thus prevent the formation of any material pressure between two trays. The plunger 20 as it descends engages tne levers 12 comparatively close to the axes thereof, so that the fingers 14, which extend 25 radially a considerable distance greater than the point of contact of the plunger with the levers serve to urge the flaps s' downward as well as toward each other, thus making a square bend and forcing the ends of the flap s' toward, the bottom B, so that the edges of these flaps s' will not stand above tne general plane of the top of the tray.