US2140719A - Method and device for feeding leaflike workpieces to a separating device - Google Patents

Description

K. ROHRBACHER Dec. 20, 1938.

METHOD AND DEVICE FOR FEEDING LEAF-LIKE WORKPIECES TO A SEPARATING DEVICE Filed.July 3, 1937 2 Sheets-Sheet l Dec. 20,1938. K. ROHRBACHER 2,140,719

METHOD AND DEVICE FOR FEEDING LEAF-LIKEWORKPIECES TO A SEPARATING DEVICE Filed July 3, 1-957 2 Sheets-Sheet 2 I 1 A e f i f //7vern.0/ I

Patented Dec. 20, 1938 UNlTED STATES PATENT OFFICE LIKE WORKPIECES TO DEVICE A SEPARATING Karl Rohrhacher, Berlin, Germany Application July 3, 1937, Serial No. 151,930 In Germany July 4, 1936 3 Claims.

This invention relates to a method and to a device for feeding leaf-shaped workpieces to a so-called separating means which in turn delivers the workpieces singly to a machine in which they are further treated. The invention is chiefly suitable for the feeding of comparatively thick or multi-layer workpieces, such as paper tubes for the production of paper bags, for which workpieces the feeding or separating devices employed up to the present are not very favorable for several reasons.

The method according to the invention consists in advancing stepwise on a feeding table in front of the separating device proper a succession of piles, formed each of a number of workpieces and so that the succession of piles remains on the feeding table always at rest until all workpieces of the actually foremost pile, which is in the position ready for feeding, have been singly removed by the separating device.

The succession of piles intermittently advancing on the feeding table may consist either of partly overlapping piles of workpieces or of piles of workpieces, the front and rear edges of which follow the one the other directly or at certain distances apart. In the first instance, that is if the piles of workpieces overlap by a certain length, the advancing of the succession of piles after the actually foremost pile has been finished, is necessary only by the length of the selected division, that is in dependency on the overlapping relation, whereas in the case of merely succeeding piles of workpieces without any overlapping, the piles move forward after the actually foremost pile has been separated by such a distance, which corresponds to the distance of the front edge of the next following pile. In the latter instance it is not necessary to lift the actually last pile at its front end if the pile succession has to be completed from the rear, as is necessary with a succession of partly overlapping piles.

For the stepwise advancing of the succession of piles whereby the pile following upon the foremost pile reaches its feeding position as soon as the foremost pile has been completely separated, the period is at disposal in which the taking off elements of the separating device have removed the last workpiece of the foremost pile, and then convey the workpiece to other elements and return into their initial position to grip a fresh workpiece, 1. e. the upper workpiece of the next following pile. This time is generally sufficient to move the succession of piles forward, even if the separating device operates with high speed so that the front edge of the first fresh pile strikes at the proper time against an abutment which determines the position for feeding.

With large sized forms, particularly if the pile succession is Without overlapping, a sufficiently slow advancing of the succession of piles can be attained thereby that the feeding movement of the succession of piles is distributed upon two or more working circulations of the separating element of the separating device. In the latter instance the machine following the separating device must admit that at certain intervals a short interruption of the feeding of workpieces takes place.

From the invention results the advantage, that the separating device can work continuously without interruption, as it is fed permanently by fresh piles of workpieces, which are successively brought upon the feeding table so that the succession of piles is permanently completed from the rear. During the advancing of the pile succession on the feeding table absolute guarantee exists, that every pile is preserved up to its separating in accurately the same condition in which it has been brought upon the feeding table, without any auxiliary means being required herefor.

An embodiment of the invention is shown, by way of example, in the accompanying drawings in which Figs. 1 to 4 show in diagrammatic illustration four working positions with employment of a pile succession in which the individual piles of Workpieces overlap partly, and

Figs. 5 to 8 illustrate the corresponding positions in a succession of piles of workpieces without overlapping.

In the first form of construction shown in Figs. 1 to 4, the piles w-i, Z02, 103, 7174 we of workpieces forming the pile succession are advanced by endless conveying bands 1 on a table plate t, until the front edge of the actually foremost pile strikes against avertical bar h.

In the working position shown in Fig. 1, the uppermost workpiece o of the first pile 101 has already been separated and is actually being conveyed. The separating element, for instance sucker c, has in the meantime descended upon the foremost pile 'LUl and just lifts a fresh workpiece in order to hand the same over in known manner to the feeding roll a rotating in the direction of the arrow, against which feeding roll apressing-0n roll I) bears which carries out an oscillating to and fro movement, so that also the fresh workpiece is fed in the direction of arrow of the preceding workpiece o to a machine for further treatment.

During the separating of the individual workpieces from the foremost pile w, the whole succession of piles remains absolutely at rest as shown by a comparison of Fig. 1 with Fig. 2, in which the separating element is just lifting off the feed table t the lowermost, i. e. the last workpiece u of the first pile 101, after the last but one workpiece 0 has already been conveyed. Only if also the last workpiece u of the first pile wl leaves the table it the succession of piles begins to move and advances by one section 3, so that the front edge of the second pile wz strikes against the vertical bar h.

The advancing of the succession of piles must be terminated before the separating element 0 has reached its lowermost position and begins to lift a fresh workpiece from the foremost pile. For advancing the successionof piles 1112, 1123, w;

'LUx after the separating of the foremost pile 201 has been terminated, that time is at disposal during which the lifting elements, for instance suckers 0, have taken over the last workpiece u of the foremost pile um and hand the same over to other elements, for instance a, b, to return them into their initial position.

Fig. 3 shows a position of the conveying device at the moment at which the succession of piles is advancing. The last workpiece u of the foremost pile has just passed through the elements a and 12, whereas the separating element 0 is just descending into its initial position. The succession of piles 102, um, L04 wx has to move only the short distance 5', before it is stopped by bar h.

Fig. 4 shows a Working position corresponding to Fig. 1 only with the difference that the workpieces of the originally second pile 102 are now separated. Whilst the last workpiece u of the foremost pile is still being conveyed the separating element 0 has descended upon the second pile wz, the front edge of which bears against bar it and the separating element is just lifting off the uppermost workpiece of this now foremost pile.

In the form of construction shown in. Figs. 5 to 8 the piles of workpieces w1, wz, wa, 1174 117:: are successively placed on the table plate t without overlapping. The table plate t is equipped in the usual manner with endless conveying bands ,2 which shift each time the succession of piles up to the stationary abutment bar it. In the position shown in Fig. 5 a separating of the uppermost workpiece 0 has already taken place, this workpiece being new conveyed in the direction of the arrow whereas the separating element 0 is just lifting afresh workpiece from the first pile of workpieces 101, this workpiece being then, as above described, handed over to the conveying roll a rotating in the direction of the arrow and cooperating with the-pressing-on roll b oscillating to and fro.

As in the form of construction described with reference to- Figs. 1 to 4 the succession of piles not overlapping one another remains absolutely at rest as long as even a single workpiece of the actually foremost pile is lyingon the table plate t, as shown in the working position illustrated in Fig. 6, in which the last but one workpiece o of the first pile is already being conveyed, whereas the separating element 0 is just taking over the lowermost workpiece u of the foremost pile. As soon. however, as the last workpiece it leaves the table plate, the succession of piles wz, we, 'LUi wx advances up to the abutment bar h by a distance 8, which corresponds to at least the full form depth of the workpiece.

In Fig. '7 an intermediate position during the advance of the succession of piles is illustrated, the front edge of the foremost pile being still at the distance $1 from the abutment bar h. The succession of piles has to travel this distance before the separating element 0, which is already in the descending movement, grips another workpiece.

In Fig. 8 the succession of piles 1112, w, m

wa has attained the fresh extreme position which corresponds to Fig. 5. Of the now foremost pile of workpieces wz, the separating element 0 is just lifting the uppermost workpiece, whereas the lowermost workpiece u of the preceding pile of workpieces can be seen as being conveyed.

I claim:--

1. A method of feeding sheet-like workpieces to a separating device, consisting in arranging the workpieces in a series of shallow piles in alignment on a feed table, removing the individual workpieces successively from the foremost pile while the series of aligned piles remain stationary, until all the workpieces have been removed from the foremost pile and feeding the series of aligned piles forwardly after the foremost pile has become exhausted, so as to bring the next foremost pile into position for enabling the individual workpieces to be removed successively therefrom.

2. A method of feeding sheet-like workpieces to a separating device, consisting in arranging the workpieces in a series of overlapping shallow piles on a feed table, removing the individual workpieces successively from the foremost pile while the series of piles remain stationary, until all the workpieces have been removed from the foremost pile and feeding the series of piles forwardly after the foremost pile has become exhausted, so as to bring the next foremost pile into position for enabling the individual workpieces to be removed successively therefrom.

3. In the method as set forth in claim 2, the further step consisting in raising the rear edge of the rearmost pile and inserting a further pile partly under the rearmost pile, each time the series of piles is fed forward, so as to maintain the number of piles in the series on the feed table.

KARL ROHRBACHER.

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