Device For Controlling Suction Retention And Separation Of Sheets

Abstract

A device for controlling suction retention and separation of sheet material such as paper is used in a sheet handling device such as a sheet counter, and comprises a vacuum pump; a suction retention head the interior pressure of which is made negative by means of the vacuum pump thereby to suck and retain the sheets one by one; a first valve for opening or closing a passage between the suction retention head and the vacuum pump; a second valve which is opened upon completion of the suction retention and separation of sheets; a third valve operating to intermittently interrupt the passage; and an electrical circuit for controlling the operations of the first and second valves, thereby to prevent the suction retention head from transferring an unnecessary additional sheet.

Description

BACKGROUND OF THE INVENTION

This invention relates to a device for controlling suction retention and separation of sheets in a device for handling sheet material such as paper (hereinafter referred to as "a sheet handling device") such as a sheet counter which carries out suction retention and separation of sheets arranged in the state of a stack or packet by suction retention means such as a suction retention head thereby to count the number of sheets, or a sheet transferring device which also carries out suction retention and separation of sheets stored in sheet storing sections thereby to transfer them to a sheet conveying device.

In such a sheet handling device as described above, the interior pressure of the suction retention head is caused to be negative thereby to suck and retain sheets one by one.

However, in a conventional sheet handling device, even if a desired number of sheets has been sucked, retained and separated by means of the suction retention head, the negative pressure is still maintained in the suction retention head for a certain period of time. Therefore, there is a possibility of sucking and retaining the next sheet out of the sheet storing section, which will cause an erroneous operation of the sheet transferring device and according an erroneous count of the sheets.

This problem of the conventional sheet handling device will be briefly described with reference to FIG. 1.

It will be assumed that, after a desired number of sheets have been transferred from a first sheet storing section 3a, a second sheet storing section 3b is to move to and be held at the position where the first sheet storing section 3a previously was, that is, sheets are subjected to suction retention and separation by a suction retention head 4 (hereinafter referred to as "a sheet dispensing position"), thus being transferred out of the sheet storing section.

In this operation, if the suction retention head 4 were to retain an additional sheet (of the first sheet storing section 3a) due to the reason given above, this sheet would be damaged by the movement of the second sheet storing section 3b to the sheet dispensing position, and if the sheets stored in the sheet storing sections were bank notes, the damage of the sheet would be a serious problem.

SUMMARY OF THE INVENTION

A first object of the invention accordingly is to solve the above-described difficulty accompanying the conventional sheet handling device.

A second object of the invention is to provide a device for controlling suction retention and separation of sheets in a sheet handling device in which a desired number of sheets are intermittently transferred one by one by means of a section retention head the interior of which is caused to be of negative pressure by a vacuum pump, and the negative pressure is intermittently reduced by valve means during the operation of transferring the sheets and is then removed by controllable valve means upon completion of transferring the sheets, thereby to prevent the suction retention head from transferring an additional sheet.

The foregoing objects and other objects as well as specific characteristics of the invention will become more apparent from the following detailed description and the appended claims when read in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings:

FIG. 1 is a diagrammatic elevation, with parts cut away, illustrating a sheet transferring device to which a device for controlling suction retention and separation of sheets according to the invention is applied;

FIG. 2 is a diagrammatic view, partly in longitudinal section, illustrating one example of the device for controlling suction retention and separation of sheets according to the invention;

FIG. 3 is a section taken along line III--III in FIG. 2, as viewed in the arrow direction, and illustrating a rotary valve assembly;

FIG. 4 is a circuit diagram, partly as a block diagram, for illustrating the operation of a first and a second electromagnetic valve;

FIG. 5(a) is a graph illustrating the relationship between a residual pressure in the suction retention head and time when the second valve is not provided in the device shown in FIG. 2; and

FIG. 5(b) is also a graph illustrating the relationship between the residual pressure in the suction retention head and time when the second valve is provided as shown in FIG. 2.

DETAILED DESCRIPTION OF THE INVENTION

Before describing a device for controlling suction retention and separation of sheets according to the invention, it is advisable to insert some preliminary descriptions of a sheet handling device in which the device of the invention is employed, although the application of the invention is not limited thereby or thereto.

Shown in FIG. 1 is a sheet transferring device 1 which is one example of a sheet handling device. This sheet transferring device 1 has a bank note container 3 comprising bank-note storing sections 3a, 3b, 3c, and 3d which contain bank notes 2 in such a manner that, for instance, 1,000-yen bank notes are in the section 3a, 5,000-yen bank notes are in the section 3b, and so forth, and transfers or dispenses bank notes of one monetary denomination or a plurality of monetary denominations according to a command signal for a desired amount of money.

The bank note storing sections 3a, 3b, 3c and 3d are arranged around a rotary shaft of the bank note container 3 and supported by a support member (not shown) fixed on the rotary shaft. Therefore, these bank note storing sections 3a, 3b, 3c and 3d can be revolved by the rotary shaft thereby to be successively moved to and set at the sheet dispensing position described above.

More specifically, according to a command signal for the desired amount of money, a necessary number of sheets of bank notes of one monetary denomination are transferred by a suction retention head 4 one by one from one bank note storing section set at the sheet separating position to a sheet conveying device 5. In this case, the head 4 swings between the sheet separating position and the sheet conveying device 5, while carrying out suction retention and separation of bank notes.

Thereafter, the next bank note storing section is set at the sheet separating position by the rotation of the rotary shaft, and transfer of a necessary number of sheets of bank notes of the corresponding monetary denomination is carried out by the suction retention head 4 in the same manner as described above.

Thus, the suction retention head 4 carries out transfer of bank notes until the total amount of money of the bank notes thus transferred reaches the desired amount of money.

The bank notes thus transferred is again transferred by the sheet conveying device 5 one by one to a sheet receiving section A.

With reference now to FIG. 2, there is shown one example of the device for controlling the suction retention and separation of sheets according to the invention which comprises; a suction retention head 4 having suction holes 6 communicated through a passage 7 with an outlet 8; a first electromagnetic valve 11 communicated with the outlet 8 through a filter 10 by means of flexible hoses 9; a second electromagnetic valve 12 of the same type as the first electromagnetic valve 11 and communicated through a hose 13 with the hose 9 provided between the filter 10 and the first electromagnetic valve 11; and a rotary valve assembly 15 connected through a hose 16 to the first electromagnetic valve 11.

The other end of the second electromagnetic valve 12 is open to the atmosphere through a communicating passage 14. The rotary valve assembly 15 has a casing 17 in which a rotary valve 18 is supported by bearings 19. One of the bearings 19 is supported by a cover 20 fixed in a recess provided on one end of the casing 17, while the other bearing 19 is retained by means of a snap ring 21 in a recess provided on the other end of the casing 17. A passage 22 bored in the casing is in communication with another passage 23 bored in the rotary valve 18. The passage 23 is connected to the first electromagnetic valve 11 by means of a hose 16.

Furthermore, the rotary valve 18 is coupled through gears 24 and 25 and worm gears (not shown) with an electric motor M. The passage 22 is connected to a vacuum pump. The middle part of the rotary valve 18 is cut at a predetermined angle of, for instance, 235.degree. as is shown in FIG. 3.

Referring also to FIG. 4, which illustrates an electrical circuit for controlling the first valve 11 and the second valve 12, the operation of the sheet transferring device will be described.

When a main switch (not shown) is closed, a signal S for starting the transfer of bank notes (hereinafter referred to as a "transfer starting signal S") and a signal t indicative of the detection of the fact that a bank note storing section is at the sheet dispensing position are applied to an AND gate 27. As a result, a command signal is produced by the AND gate 27 whereby a relay driving circuit 28 is operated to activate a relay 29. Hence, contacts provided for the first ad second electromagnetic valves 11 and 12 are operated so that their armatures are thrown to the positions a of the contacts.

As a result of this operation, the first electromagnetic valve 11 is opened, while the second electromagnetic valve 12 is closed. Accordingly, the interior pressure of the suction retention head 4 is caused to be negative by the vacuum pump P. This negative pressure causes the suction retention head 4 to suck and retain the bank note in a bank note storing section confronting the suction retention head 4 thereby to separate it from the other bank notes in the bank note storing section. The sheet thus separated is transferred to the sheet conveying device 5 (FIG. 1) by the suction retention head 4. Thereafter, the suction retention head 4 is returned to the sheet separating position described above to such and retain the succeeding bank note and then to transfer it. This operation is repeated until the desired number of sheets of bank notes are transferred out of the bank note storing section.

If, in this operation, the negative pressure is continuously maintained in the suction retention head 4 until the desired number of sheets of bank notes have been transferred out of the bank note storing section, there is a risk of damaging the bank notes. In order to eliminate this risk, according to the invention, the negative pressure in the suction retention head 4 is temporarily reduced as described below.

The rotation of the motor M is transmitted through the gears 24 and 25 to the rotary valve 18. In this case, as the rotary valve 18 is rotated by the motor M, it temporarily interrupts or closes the passages 22 and 23 by means of the cut or notch (FIG. 3) provided in the rotary valve 18. Accordingly, the bank notes can be transferred by the suction retention head 4 one by one to the sheet conveying device 5 without causing trouble in the sheet transferring device or damage to the bank note.

This sheet transferring operation is repeated as many times as the number of sheets of bank notes set by a control section (not shown) and then stopped.

Upon stopping of the sheet transferring operation, the operation of the relay driving circuit 28 is stopped because no transfer starting signal S is applied to the AND gate 27. As a result, the relay coil 29 is de-energized, and the armatures of the contacts of the valves 11 and 12 therefore return to their initial positions b of the contacts. Accordingly, the first electromagnetic valve 11 is closed, while the second electromagnetic valve 12 is opened, as a result of which the negative pressure is eliminated in the suction retention head 4. Therefore, the suction retention head no longer sucks and retains a bank note even if it is returned to the sheet sucking position.

Thereafter, the next bank note storing section 3b, for instance, is set at the sheet dispensing position, and a transfer start signal S and a position detecting signal t with respect to the bank note storing section 3b are applied to the AND gate 27, as a result of which a desired number of sheets of bank notes are transferred out of the bank note storing section 3b in the same manner as described above.

In this connection, the effect of the second electromagnetic valve 12 will be described with reference to FIGS. 5(a) and 5(b) for the purpose of making clearer the operation of the device of the invention.

If the second electromagnetic valve 12 is not provided in the device for controlling suction retention and separation of sheets, as is shown in FIG. 5(a), it will take a relatively long time (from t.sub.1 to t.sub.3) for the negative pressure in the head 4 to rise to zero, that is, the atmospheric pressure. However, since the second electromagnetic valve is provided in the device, the time for the negative pressure to rise to zero can be shortened as is shown by the time (from t.sub.1 to t.sub.2) in FIG. 5(b).

In these FIGS. 5(a) and 5(b), reference character t.sub.1 is the time instant when a desired number of sheets have been transferred out of one sheet storing section.

While the principles of the invention have been described above in connection with a specific embodiment, it is to be clearly understood that the invention is not limited thereto or thereby.

That is, the device for controlling suction retention and separation of sheets according to the invention can be applied to various sheet counters, such as a device comprising a plurality of suction retention heads provided on a rotary disk for the purpose of counting the number of sheets arranged in the state of a stack or packet, or a device which counts the number of sheets with a suction retention plate and a sheet separating rod.

Furthermore, the device according to the invention can be applied to sheet transferring devices which are different in construction from that shown in FIG. 1.

It is not always necessary that the third valve 18 be a rotary valve.

According to the invention, after completion of counting the number of sheets or transferring of a necessary number of sheets, the second electromagnetic valve 12 is opened to eliminate the negative pressure (or residual negative pressure) left in the suction retention head 4. As a result, the suction attraction and retention of the next sheet is prevented, and erroneous counting or transferring of the sheets can be therefore avoided, that is, the suction retention head 4 will never suck and retain more than a predetermined number of sheets. Furthermore, damaging of the sheets due to the movement of the sheet storing sections can be also prevented.

Claims

We claim:

1. A device for suction retention and separation of sheets which comprises;

a sheet container for storing the sheets which are stacked or lined;

a sheet conveying device;

a suction retention head being disposed swingably between said sheet container and said sheet conveying device to transfer the sheets from said sheet container to said sheet conveying device by sucking, retaining and separating the sheets one by one;

a vacuum pump for supplying a negative pressure to said suction retention heads;

a mechanical valve being disposed in a communication passage communicating between said suction retention head and said vacuum pump, said mechanical valve opening and closing the passage dependent upon the positions of said suction retention heads;

a first valve being disposed in a first portion of the communication passage between said suction retention head and said mechanical valve, said first valve interrupting the supply of the negative pressure from said vacuum pump before closure of said mechanical valve so that after a pre-determined number of sheets have been transferred to said sheet conveying device transfer of an additional sheet is prevented;

a second valve of normally-closed type being disposed in a second portion of the communication passage between said suction retention head and said first valve;

a relay circuit for opening and closing said first valve and said second valve;

contact means responsive to said relay circuit for opening and closing said first valve and said second valve; and

a relay driving circuit having an input terminal for applying a sheet counting termination signal to said relay circuit to operate the latter, whereby when said suction retention head swings toward said sheet container after the pre-determined number of sheets has been transferred to said sheet conveying device said first valve is closed, while said second valve is open so that a residual vacuum present in the communication passage between said suction retention head and said first valve is eliminated by the opening of said second valve and suction of a sheet is no longer carried out even if said suction retention head has been swung to a sheet sucking position.