GB1578119A - Shingling device for use in machines for handling envelopes and the like flat flexible articles - Google Patents

Description

(54) "SHINGLING DEVICE FOR USE IN MACHINES FOR HANDLING ENVELOPES AND THE LIKE FLAT FLEXIBLE ARTICLES " (71) We, DRG (UK) LIMITED, of 1 Redcliffe Street, Bristol BS99 7QY, a British Company, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to machines for handling envelopes and like flat flexible articles such as paper bags. Such articles are hereinafter referred to simply as " en envelopes".

The present invention provides a device for shingling envelopes (as defined herein), comprising a shingling roller rotatable in one sense, and an endless conveyor trained around the shingling roller in one or more recesses extending around the periphery of the shingling roller and movable at a speed slower than that of the periphery of the shiugling roller in the same sense to receive envelopes therefrom at a shingling station where the conveyor leaves the roller, whereby a series of envelopes delivered in succession to the shingling roller in spaced relationship, are carried around with the shingling roller, stripped from the roller by the conveyor at the shingling station, and decelerated to the speed of the conveyor to produce shingled formation.

Preferably the shingling device further comprises means for deflecting the trailing edge of a leading envelope at the shingling sta.lion away from the roller to allow the leading edge of a following envelope from the shingling roller to pass between the trailing edge of the leading envelope and the conveyor to produce a shingled formation of the envelopes. Preferably, the means for deflecting the trailing edge of said leading envelope at the shingling station away from the roller is a cam on the cylindrical surface of the shingling roller, having a step in the trailing portion thereof, whereby in use a following envelope can be delivered to the shingling roller with the leading edge thereof abutting the step and the cam deflects the trailing edge of the leading envelope over the leading edge of the following envelope as the following envelope catches up with the leading envelope.

The conveyor may comprise a plurality of parallel endless belts, and is preferably provided with means for holding The shingled envelopes thereto to assist the deceleration.

Such means may comprise, for example, suction means and/or a clamping roller or rollers. Gripping or suction means can also be provided on the shingling roller, if neces sa.ry. The envelopes are preferably delivered to the shingling roller by a nip comprising two rollers rotating at a speed slightly faster than that of the shingling roller to push the envelopes positively against the step.

The shingling device can be incorporated into a machine for applying gum to the seal ing flaps of envelopes following formation of the envelopes. In such a machine, the envelopes can, for example, be fed to a shingling device as described herein, arranged to shingle the envelopes such that only the parts to be gummed are exposed.

The shingled envelopes can then be fed to a generally conventional gumming machine, including a gumming roller which applies gum to the exposed parts of the envelopes.

To prevent neighbouring envelopes sticking to each other, the speed of the envelopes can then be increased slightly to increase the pitch of the shingling and separate the gummed parts. The envelopes can then be fed to drying means. The gumming roller can be of a resilient material, such as rub ber, to accommodate by compression different thicknesses of shingled enevelopes, for example, at the seams thereof.

The shingling device of the invention can be incorporated in a machine for handling wet pre-gummed envelopes by including recesses where necessary, for example, in one roller of the nip, to prevent wet gummed parts being touched.

A preferred embodiment of a device according to the invention incorporated into a machine for applying gum to the sealing flaps of envelopes will now be described, by way of example only, with reference to the accompanying diagrammatic drawings, of which: Figure 1 is a side view of the complete machine, Figure 2 is a plan view of the shingling roller, and Figure 3 is a top view of the gumming unit.

Referring to the drawings, and firstly to Figure 1; envelopes 10 for gumming are first delivered to an endless conveyor 16 in a conventional manner with their sealing flaps, open and facing outwardly, at their trailing edges on input rollers 12, 14, which are provided with suction means (not shown) to hold the envelopes thereto. Conveyor 16, which is similarly provided with suction means 18, then carries the envelopes upwardly to a nip comprising rollers 20, 22, which pushes the envelopes towards shingling roller 24. Shingling roller 24 is provided with two cams 26 having steps 23 to be engaged by the leading edges of the envelopes, and to ensure this engagement the peripheral speed of rollers 20, 22 is slightly faster than that of conveyor i 6 and roller 24, whereby the leading edge of each envelope is pushed into contact with a step 23.

Shingling roller 24 carries envelopes 10 round towards a shingling station 28, and, .as can be seen in Figure 2, has parallel endless conveyor belts 32 running in recesses 30 in the surface thereof. Belts 32 run at a speed considerably slower than that of roller 24, and transport the envelopes from roller 24 to gumming unit 38. In practice, the roller 24 is constructed from a number of discs 25 secured to the shaft 29 of the roller with separate annular pulleys 27 located be Iween the discs and coaxial therewith to carry the belts 32. The pulleys are freely rotatable relative to the discs 25 so that the belts can run at a much slower speed, for example 40 ft./min. as compared with 1000 ft./min. of the envelopes before shinglilig. Suction means 34 is provided below tile belts 32 and a clamping roller 36 is arranged for gripping envelopes thereto as they leave the roller. An envelope 10 arriving at shingling station 28 on roller 24 is stripped therefrom by belts 32 and, being held to belts 32 by clamping roller 36 and suction means 34, is decelerated to the speed of belts 32. The trailing edge of this first envelope is lifted by cams 26 on the discs 25 on arrival of the following envelope, so that the following envelope is similarly decelerated while it is partially beneath the first envelope. The envelopes 10 can thus be shingled with only the parts to which gum is to be applied exposed.

The roller 36 helps to control the envelopes when there is very close shingling so that there is a considerable thickness of material ill the shingled layer. However, if the envelopes are pregummed, this roller can be omitted to prevent contact with the gummed area.

The gumming unit 38, shown in Figures I and 3, comprises gum supply means (not shown), rollers 40, 42 which carry gum to transfer roller 44, and gumming roller 46 which moves at the speed of the conveyor 32. Transfer roller 44 is of the same length as the width of the gummed area required on the envelope, which may be less than the total width of the envelope if, for example, the corners of the sealing flaps of an envelope are rounded and expose parts of the body of the envelope beneath. Thus, only a part of the gumming roller 46 is supplied with gum. Gumming roller 46 is made of rubber or a similarly resilient material in order to accommodate the varying thicknesses of different parts of the envelopes.

For example, that part of roller 46 which applies gum to a part of a sealing flap covering the seams of the envelopes beneath will be compressed. The transfer roller 44 is of aluminium or other lightweight material and is not securely journalled at its ends. It simply rests on the rollers 42, 46 and the amount of glue transferred is in part determined by the weight of the roller 44.

Immediately after passing gumming roller 46, the envelopes are transferred from belts 32 to an endless conveyor 48, comprising parallel bands, which is provided with strong suction means 50 below the conveyor to hold the envelopes thereto, and ensure they do not remain in contact with gumming roller 46. Conveyor 48 moves slightly faster than belts 32 in order to slightly separate the gummed portions of the envelopes, as shown in Figure 3, and prevent them from sticking together. The envelopes are then dried by hot air blown from a drying hood 52, while being held to conveyor 48 by further suction means 54 below the conveyor, and can be fed to means for unshingling them and folding over the sealing flaps.

The above described machine can be modified for shingling pre-gummed envelopes, if desired, with provision for not touching wet gummed parts. This can be readily achieved by omitting gumming unit 38 and providing suitable recesses in rollers 14 and 20, in order not to touch wet gummed parts. Clamping roller 36 is either similarly recessed or omitted altogether.

The drying hood 52 is supplied with hot air which issues through longitudinal slots in a plate 53 located close to the top surface of the shingled envelopes. It is therefore important to provide effective suction below the conveyor to ensure that the gummed regions do not touch the plate 53. To this end, it is desirable to try and ensure that external air does not flow into the space between the hood and the shingled envelopes at the entrance to the drying hood, and that hot air does not flow out of this space at the other end of the drying hood, since this would create a flow of air which would tend to lift the gummed flaps in the shingled layer. Accordingly, the hot air enters the hood through ducts 55 which are angled towards the entrance to the drying hood, thereby creating, greater air pressure at that end 57 than at the other end 59, and therefore a flow of air towards end 57.

Also, the suction from the suction means 54 is arranged to be lower at the entrance end 57 than at the exit end 59, thereby also tending to raise the pressure at the entrance end relative to the exit end. The result is that ambient air tends to enter under the hood at the exit end, and hot air tends to flow out from under the hood at the entrance end.

The apparatus described above has various notable features. One such feature is the arrangement for shingling the envelopes. Another feature is the use of suction under the conveyor as the sole means of holding the envelopes to the conveyor after gumming, thereby avoiding any contact with the gummed top surface of the shingled layer. This allows efficient hot air drying as shown, and also allows the width of envelope to be changed without elaborate modifications to the conveyor means as in conventional arrangements, and further allows gumming across substantially the full width of the shingled layer.

WHAT WE CLAIM IS: 1. A device for shingling envelopes (as defined herein), comprising a shingling roller rotatable in one sense, and an endless conveyor trained around the shingling roller in one or more recesses extending around the periphery of the shingling roller, and movable at a speed slower than that of the periphery of the shingling roller in the same sense to receive envelopes therefrom at a shingling station where the conveyor leaves the roller, whereby a series of envelopes delivered in succession to the shingling roller in spaced relationship, are carried around with the shingling roller, stripped from the roller by the conveyor at the shingling station, and decelerated to the speed of the conveyor to produce a shingled formation.

2. A shingling device according to claim 1 further comprising means for deflecting the trailing edge of one envelope at the shingling station away from the roller to allow the leading edge of a following envelope from the shingling roller to pass between the trailing edge of said leading envelope and the conveyor to produce a shingled formation of the envelopes.

3. A shingling device according to claim 2 wherein the means for deflecting the trailing edge of said leading envelope at the shingling station away from the roller is a cam on the cylindrical surface of the shingling roller, having a step in the trailing portion thereof, whereby in use said following envelope can be delivered to the shingling roller with the leading edge thereof abutting the step and the cam deflects the trailing edge of said leading envelope over the leading edge of the following envelope as the following envelope catches up with the leading envelope.

4. A shingling device according to claim 3 including a nip for delivering envelopes to the shingling roller, which nip runs at a peripheral speed faster than that of the shingling roller to push the leading edge of an envelope into contact with the step of the cam.

5. A shingling device according to any one of the preceding claims wherein the conveyor comprises a plurality of parallel endless belts running in respective said recesses in the shingling roller.

6. A shingling device according to any one of the preceding claims wherein the conveyor is provided with suction means to hold shingled envelopes thereto after passing the shingling station.

7. A shingling device according to any one of the preceding claims wherein a clamping roller is provided to hold shingled envelopes to the conveyor at the shingling station.

8. A device for shingling envelopes, substantially as described herein with reference to the accompanying drawings.

9. A shingling device according to any one of the preceding claims in combination with a gumming device arranged to receive the shingled envelopes and to continuously apply gum to the exposed surfaces of the shingled envelopes in passing.

10. A machine for manufacturing or handling envelopes incorporating a shingling device according to any one of the preced

Claims (1)

1. ing claims.