APPARATUS FOR FEEDING SHEET MATERIAL

APPAREIL D'ALIMENTATION EN MATERIAU SOUS FORME DE FEUILLES

English Abstract

There is disclosed apparatus for feeding sheet material comprising a feed
table (10) having a gate (11) and upon which the sheets (5) may be stacked
against the gate which allows only the lowermost sheet to pass therebeneath, a
bed (13) or rollers (14) within the surface of the table which may be
rotatably driven to advance the lowermost sheet beneath the gate into the nip
of take-up rolls (12) and means to allow the rollers to free-wheel once the
lowermost sheet is being advanced by said take-up rolls.

French Abstract

L'invention a pour objet un appareil servant à l'amenée d'un matériau en feuilles. Cet appareil comprend une table d'alimentation (10) présentant un dispositif d'entrée (11) et sur laquelle les feuilles (5) peuvent être empilées contre le dispositif d'entrée, lequel ne permet qu'à la feuille située le plus en dessous de passer. L'appareil comprend également un banc (13) de rouleaux (14) situé sous la surface de la table, qui peut être entraîné en rotation pour faire avancer la feuille située le plus en dessous au-delà du dispositif d'entrée, dans la ligne de contact des rouleaux récepteurs (12), et des moyens permettant aux rouleaux de tourner librement une fois que la feuille située le plus en dessous a été avancée par les rouleaux récepteurs.

Claims

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CLAIMS
1. Apparatus for feeding sheet material comprising a feed table having a gate
and upon which the sheets may be stacked against the gate which allows only the
lowermost sheet to pass therebeneath, a bed of rollers within the surface of the table
which may be rotatably driven to advance the lowermost sheet beneath the gate into the
nip of take-up rolls and means to allow the rollers to free-wheel once the lowermost sheet
is being advanced by said take-up rolls.
2. Apparatus according to claim 1 wherein the rollers are fitted with sprag
clutches and advance the sheet being fed at a slower speed than that of the take-up rolls.
3. Apparatus according to claim 1 or claim 2 wherein vacuum suction is
applied from beneath the rollers to pull the lowermost sheet downwardly thereagainst.
4. Apparatus according to any one of claims 1 to 3 wherein the rollers are
spaced such that the lowermost sheet can drape to give substantial area contact between
the sheet and the rollers.
5. Apparatus according to any preceding claim wherein the rollers are rotably
interconnected by drive belts and one is driven by a further drive belt reciprocated by an
arm operating in time with line speed.
6. Apparatus according to claim 5 wherein said further drive belt is toothed.

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7. Apparatus according to any one of claims 1 to 4 wherein the rollers are
driven by an electric motor.
8. Apparatus according to claim 7 wherein the rollers are driven
intermittently.
9. Apparatus according to claim 7 wherein the rollers are driven continuously.

Description

CA 02213447 1997-08-19
W 096/29269 PCT/GB95/02097
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APPARATUS FOR FEEl~I~G S~ ET MATERL~L
This invention concerns d~aLdLLIs for feeding sheet material, particularly,
though by no means exclusively, of corrugated board or card as used in the box and
carton m~king industries.
In general, stacked sheets are placed on a feed table against a gate which
allows only the lowermost sheet to pass therebeneath under the action of a reciprocating
vacuum suction cup, feed rollers or a kicker mech~ni~m, to be taken into the nip of take-
up rolls. Such feeding arrangements must be controlled with great precision and even
then misfeeds are a not uncommon experience.
One solution to these problems is proposed in my co-pending British Patent
Application No. 9326089.1, but this involves reciprocating movement of the entire roller
bed, which is not energy efficient and places certain restrictions on sheet size.
According to the present invention there is provided a~ dLLIs for feeding
sheet material comprising a feed table having a gate and upon which the sheets may be
stacked against the gate which allows only the lowermost sheet to pass therebeneath, a
bed of rollers within the surface of the table which may be rotatably driven to advance
the lowermost sheet beneath the gate into the nip of take-up rolls and means to allow the
rollers to free-wheel once the lowermost sheet is being advanced by said take-up rolls.
The rollers may be fitted with sprag clutches and may advance the sheet
being fed at a slower speed than that of the take-up rolls.

CA 02213447 1997-08-19
W 096/29269 PCT/GB95102097
Vacuum suction may be applied from beneath the rollers to pull the
lowermost sheet downwardly there~in.~t
The rollers may be spaced such that the lowermost sheet can drape to give
substantial area contact between the sheet and the rollers.
The invention will be further apparent from the following description, with
reference to the figures of the accompanying drawing, which show, by way of example
only, one form of sheet feeding apparatus embodying same.
Of the drawing :-
Figure 1 shows a side elevation of the apparatus, and
Figure 2 shows a cross-section through the a~ LIls on the line II-II
of Figure 1.
Referring now to the drawing, it will be seen that the apparatus comprises
a feed table 10 upon which a stack of sheets S may be placed against a gate 1 1 beneath
which only the lowermost sheet in the stack may pass.
Successive sheets are advanced beneath the gate 11 into the nip of take-up
rolls 12byabed 13 of rollers 14withinthesurfaceofthetable.

CA 02213447 1997-08-19
W O 96/29269 PCT/GB9S/02097
The rollers are mounted within a chamber 15 to which vacuum suction is
applied to pull the lowermost sheet dow,lw~dly there~g~in~t. The spacing between the
rollers 14 allows the sheet to drape between them to enhance the area of contact.
The rollers advance the lowermost sheet by being rotatably driven as
indicated by the arrows X at a speed less than the speed ofthe take-up rolls 12. Once the
sheet is advanced by the rolls 12 the rollers 14 free-wheel, the rollers 14 having sprag
clutches between their inner peripheries and their drive shafts 16.
In this example, the rollers 14 are rotatably interconnected by drive belts
17 and one roller 14 is driven by a belt 18 itself driven from a toothed belt 19reciprocated by an arm 20 operating in time with line speed (typically that previously
used for a kicker me~h~ni~m, facilit~ting easy retro-fitting). On the reverse stroke of the
arrn 20 the rollers 14 are not driven in reverse direction since they are then in their free-
wheeling mode.
It will be appreciated that it is not intended to limit the invention to the
above example only, many variations, such as might readily occur to one skilled in the
art, being possible, without departing from the scope thereof as defined by the appended
claims.
Thus, for example, the rollers 14 may be driven intermittently or
continuously by an electric motor, though this is not preferred since, in the case of a
continl-ous drive, there will be some slippage between the rear~vard rollers and the next
sheet to be fed until the previous sheet has cleared the gate 11.

Representative Drawing