This invention relates to an automatic paper cutting system for a printer, more particularly, though not exclusively, to a computer coupled dot matrix printer of 40, 80 and 136 column size providing customized bills and receipts to customers.. The cutting system proposed herein ensures that paper of just the required length is utilized for every print-job avoiding waste of paper.
Printers, for example, dot matrix printers are usually provided with a serrated edge made of plastic near the print-head for enabling the user to tear out the paper, manually, after printing. This is particularly so when the paper used is of the "continuous" type. After frequent use, the edge wears away. Any further use of the edge after it has become blunt would only result in the paper becoming mutilated while tearing it off replacement of the edge with a new one is a cumbersome task.
While automatic cutters for printers are known, such cutters do not have the same facility in operation and use as the one proposed herein.
This invention not only seeks to overcome the abovementioned drawbacks, but proposes a paper

cutting system which dispenses with manual cutting operations and provides for automatic cutting of paper.
Thus after very page a Bill or other document is printed, the user has only to give a command to the programmed computer to initiate automatic cutting of the paper. Alternatively, after printing of every page is over, a programmed computer connected to the printer cuts off the paper.
Of course there is "continuous" type paper available in which perforations are provided at the end of each page. In this case, also although the use of a serrated edge may not be necessary, the user has still to tear off the paper manually, after printing. This operation is eliminated in the printer proposed herein.
In any event, manual intervention for tearing off paper from the printer entails a rather crude or clumsy procedure which, not infrequently, results in not merely tearing off the paper, but tearing the paper itself.

This invention, therefore, proposes an automatic paper cutting system for a printer which enables paper, in a printer, after printing, to be cut off automatically. This is a clean, efficient, time saving and a one shot operation.
This invention is especially useful in large sales establishments where billing takes place throughout the day against frequent customer purchases.
While automatic cutters for printers are known, such cutters do not have the same facility in operation and use as the one proposed herein.
What has been stated above with regard to billing will equally be applicable in cases of other printer uses as well.
The automatic paper cutting system for a printer, according to this invention comprises an arm carrying a horizontally disposed spring-loaded knife mounted above the print-head and behind the paper, said knife being movable with the print-head, said knife being normally in the retracted position; a horizontal channel provided behind the paper and above the print-head; means for activating the arm to

cause the knife to move out from its retracted position, pierce the paper and enter the channel and simultaneously move horizontally therein, with the print-head, to cut the paper along its breadth, said means thereafter de-activating the arm to retract the knife from the channel.
This invention will now be described with reference to the accompanying drawings which illustrate, by way of example, and not by way of limitation, one of possible embodiments of the automatic paper cutting system for a printer proposed herein
Fig. 1 illustrating the pivoted arm, the solenoid and
the knife in retracted position
Fig. 2 illustrating a sectional view of the channel
through which the knife travels during cutting.
Fig. 3 illustrating the pivoted arm, the solenoid and
the knife just piercing the paper
Fig. 4 illustrating a sectional view of the channel into
which the knife has just entered on piercing the
paper.
Fig.5 illustrating the pivoted arm, the solenoid and
the knife fully piercing the paper
Fig. 6 illustrating a sectional view of the channel into
which the knife has fully entered on piercing the
paper.

A pivotably mounted arm A carries a horizontally disposed spring-loaded knife K mounted above the print-head in front of the paper D, said knife being movable with the print-head, normally in the retracted position; under spring tension. The knife has a holder H from which the knife moves out for cutting the paper and thereafter retracts into it when the knife is at rest.
A horizontal channel C is provided behind the paper and above the print-head. Means are also provided for activating the arm to cause the knife to move out from its retracted position, pierce the paper, enter the channel and simultaneously move horizontally therein, along with the print-head, to cut the paper along its breadth, said means thereafter de-activating the arm to retract the knife from the channel under spring tension.
The means aforesaid, in one of possible forms, consists of a solenoid S with a piston or plungeiffor activating the arm.
The paper D is provided with a back-support G to act as a rest for keeping die paper sufficiently taut while the knife pierces it.
When the user has completed printing a page, all that he has to do is to press a key from the operation panel of the printer. The printer is programmed to then

energise the solenoid, which causes the piston to move out and activate the arm A. The knife K then extends out of the holder H to pierce the paper and enter the channel C.
Simultaneously the print-head moves from one side of the paper to the other, carrying the knife with it, the knife cutting the paper from side to side. The knife thereupon retracts into the holder H. The cut portion of the paper is thereafter removed fi'om the printer by the user or by the customer, as the case may be.
Alternatively, this feature can be invoked by the software and the command can be passed from the computer to the printer as a part of file signal. For example, whenever the user wanfeto cut the paper, then he will add the following code into the software "Esc {c'\ Once the printer reads this command it will cut the paper, which causes the piston to move out and activate the arm A. The knife K then extends out of the holder H to pierce the paper and enter the chaimel C.
Simultaneously the print-head moves from one side of the paper to the other with the knife cutting the paper from side to side. The knife thereafter retracts

into the holder The cut portion of the paper is then removed from the printer by the user or by the customer, as the case may be.
It will be appreciated that various other embodiments of this invention are possible without departing from the scope and ambit thereof.

We Claim:
1. An automatic paper cutting system for a printer, comprising an arm carrying a horizontally disposed spring-loaded knife mounted above the print-head and behind the paper said knife being movable with the print-head, said knife being normally in the retracted position; a horizontal channel provided behind the paper and above the print-head; means for activating the arm to cause the knife to move out from its retracted position, pierce the paper and enter the channel and simultaneously move horizontally therein, with the print-head, to cut the paper along its breadth, said means thereafter de¬activating the arm to retract the knife from the channel.
2. An automatic paper cutting system for a printer as claimed in Claim 1 wherein the said means consist of a solenoid.
3. An automatic paper cutting system for a printer as claimed in Claim 2 wherein the solenoid has a piston for activating the arm.
4. An automatic paper cutting system for a printer as claimed in any one of the preceding Claims wherein the knife is provided with a holder.

An automatic paper cutting system as claimed in Claim 1 wherein the arm is pivotably mounted.
6. An automatic paper cutting system for a printer as claimed in anyone of the preceding claims wherein the paper is provided with back support.
7. An automatic paper cutting system for a printer
substantially as herein described with reference
to, and as illustrated in, the accompanying
drawings.