GB2092556A

GB2092556A - A sheet feeder device for the intermittent supply of sheets

Info

Publication number: GB2092556A
Application number: GB8202087A
Authority: GB
Original assignee: Grassi Alfredo & C
Current assignee: Grassi Alfredo & C
Priority date: 1981-02-06
Filing date: 1982-01-26
Publication date: 1982-08-18
Also published as: FR2499529A1; ES262683Y; ES262683U; DE3202037A1; IT8119551A0; IT1135333B

Abstract

In a belt operated sheet feeder device sheet separating belts (1) are intercalated between fixed supports (3) which support the pile of sheets (4). The upper horizontal sections of these belts are cyclically raised by an underlying transverse roller (6) to bring the belts, at predetermined time intervals, into contact with the lower sheets of the pile. In this way the said lower sheet is drawn out from the pile and forwarded to an operating machine for subsequent working. <IMAGE>

Description

SPECIFICATION A belt operated sheet feeder device for the intermittent supply of boards or blanks The present invention relates to a belt operated sheet feeder device for the intermittent supply of boards or blanks.

As is known, machines intended to operate on blanks, sheets of board and the like are usually provided with belt operated sheet feeder devices.

In such feeder devices, flat blanks or boards are stacked between suitable vertical guides, adjustable in dependence on the required shape (constituting the so-called magazine) and positioned directly over rubber belts which are moved at a suitable speed.

In front of the said stack of sheets there are arranged one or more gauge plates which are adjustable in height and which define a small opening through which only one sheet can pass at a time.

Obviously, such sheet feeders operate continuously so that they cannot be utilised on a machine intended to operate on blanks or boards with a cyclic mechanism (folding machines, pasting machines and others) and which therefore require a controlled supply, commonly termed a "triggered" supply or a "timed" supply or, alternatively a "rhythmic" supply.

The object of the present invention is that of eliminating the said functional limitation, providing a belt operated sheet feeder device which will be able to supply sheets of board or blanks in a discontinuous manner, in synchronism with the requirements of a subsequent operating machine working on the same sheets.

Within the ambit of the function explained above, another object of the invention is that of providing a belt operated sheet feeder device, in which the stack of sheets of board or blanks do not rest directly on the resilient belts themselves, in such a way as not to cause a progressive slackening of these latter.

The said function, as well as the previously indicated objects, and others which will become more apparent below, are achieved by a belt operated sheet feeder device according to the present invention, characterised by the fact that it comprises fixed supports intercalated between the belts and carrying the stack of sheets of board or blanks, and is provided with means operable cyclically to raise the belts themselves in such a way as to bring them into contact with the lower face of the first sheet of the stack, drawing it by friction out from the magazine through the aperture delimited by the front gauge plate constituting an integral part of the magazine itself.

Advantageously, the cyclic raising of the said rubber belts, moving at a suitable speed, is effected by means of a roller pivoted at its ends on two arms and operable to oscillate about a horizontal axis under the action of a disc cam.

Obviously, the rotation of such cam is in synchronism with the operating cycle of the machine being supplied, in such a way as to cause individual sheets to be introduced into the machine itself at predetermined time intervals.

The said fixed supports for supporting the stack of sheets of board, or blanks, have, in correspondence with the said roller, a concave portion which allows a sufficient raising of the roller itself such that this latter can press the rubber belts against the lower sheet of the stack.

It is suitable, likewise, to emphasise that the oscillation of the said roller about the support axis of its pivoted arms can be obtained with other suitable movement transformation systems.

The invention will now be described further by way of example with reference to the accompanying drawings in which: Figure 1 illustrates a vertical section of the sheet feeder device, with the belts in a lowered position with respect to the plane defined by the fixed supports for the stack of sheets of board or blanks; Figure 2 illustrates the same section, but with the belts brought into contact with the stack of sheets, in such a way as to cause the lower sheets of the stack to be moved by friction; Figure 3 schematically illustrates the sheet feeder in plan view from above.

With particular reference to the reference numerals of the various figures of the attached drawings, the sheet feeder device in question comprises a series of suitably spaced parallel rubber belts 1 subtended between two drums 2 and 2' one of which is a driving drum.

Intercalated between these belts there are arranged fixed supports 3 constituted by horizontal rectilinear bars which define a plane of support the height of which is sufficiently far above the level of the said belts.

By means of this arrangement the stack 4 of sheets of board or blanks is supported by the plane formed by the said horizontal bars, which have, in corresponding positions along their lower perimeter, a concave portion 5.

Along the recesses delimited transversely of the said bars by such concave portions there is arranged a horizontal roller 6 pivoted at its ends on two arms 7 freely turnable about an axis 8.

In operation by pressing the said roller upwardly, this causes the raising of the belts 5 bringing them into contact with the lower sheet of the stack 4. In this circumstance the belts themselves draw the said lower sheet past the gauge 9 which stops the upper sheets, forwarding it by the joint action of presser rollers 10 and guide rollers 11 towards the machine intended to work subsequently on the same sheet.

The raising of the roller 6, in particular, can be caused by a pair of disc cams 1 2 rotating in contact with the roller itself. The speed rotation of such disc cams obviously will be correlated to the operating cycle of the specific machine to be supplied.

From what has been explained above and from observation of the various figures of the attached drawings, the major part of the function and the practicality of use which characterises the belt-operated sheet feeder device constituting the subject of the present patent application will be apparent.

Obviously, the sheet feeder device and the associated manner of making it have been described and illustrated above purely by way of indicative but non-limitative example and solely for the purpose of demonstration of the practical feasibility and general characteristics of the present invention.

From the above statements it can consequently be deduced that the rubber belt sheet feeder device in question, and its component parts, can be subjected to numerous variations and modifications for manufacturing convenience, and the specific practical use from time to time envisaged for the sheet feeder device itself and, also, can be subjected to those improvements which are suggested by practical experience, all without departing from the scope of the present invention.

Claims

1. A belt-operated sheet feeder device characterised by the fact that it includes fixed supports intercalated between the belts, which supports carry the stack of sheets of board or blanks, and is provided with means operable cyclically to raise the belts themselves in such a way as to bring them into contact with the lower face of the first sheet of the stack, drawing this by friction out from the magazine through an opening delimited by a front gauge constituting an integral part of a magazine housing the stack itself.

2. A sheet feeder device as claimed in Claim 1, characterised by the fact that the said fixed supprts are constituted by horizontal rectilinear bars which define a support plane having a height sufficiently above the level of the said belts, these horizontal bars having a concave portion in corresponding positions in the lower edges thereof.

3. A sheet feeder device as claimed in Claim 1 or Claim 2, characterised by the fact that along the notches delimited by the said concave portions there is arranged a horizontal roller pivotally mounted at its ends on two arms freely articulated about an axis, such roller being able to oscillate about the said free axis.

4. A sheet feeder device as claimed in any preceding claim, characterised by the fact that the lower peripheral portion of the said roller is in contact with a pair of suitably shaped disc cams rotating with a given but adjustable angular velocity, and operable to periodically press the roller itself upwardly, such raising action of the said roller being obtainable, however, with other suitable kinematic movement transformation systems.

5. A belt-operated sheet feeder device substantially as hereinbefore described with reference to the accompanying drawings.