Unit for selecting and separating reams from a stack of sheets

Abstract

 A ream (2) is selected and separated from a stack (3) of sheets (4) by means of a separating member (16) which is inserted inside the stack (3) at an insertion region (18) defined by images acquired by a television camera (10) moved vertically to scan a given scanning region (12) of the stack (3); the television camera (10) and the separating member (16) being so oriented with respect to each other that the insertion region (18) lies in the scanning region (12).

Description

[0001] The present invention relates to a unit for selecting and separating reams from a stack of sheets of paper or similar.

[0002] More specifically, the present invention relates to a unit for selecting and separating reams from a stack of sheets, of the type comprising a television camera movable in a substantially vertical direction along the stack to acquire images of the sheets at a given scanning region; and a separating member which is inserted inside the stack to separate the reams successively from the stack.

[0003] The images acquired by the television camera are used by an electronic central control unit to control the movement of the separating member in said vertical direction, to count the number of sheets in a ream during said movement of the separating member, and to arrest the separating member at the last sheet in the ream to be removed.

[0004] Once positioned at the last sheet in the ream to be removed, the separating member is moved into contact with the stack at a given insertion region, and is inserted inside the stack to separate the ream from the stack.

[0005] Known units of the type described above have various drawbacks, mainly on account of the television camera and the separating member being so oriented with respect to each other that the scanning region, where the television camera acquires the sheet images used by the electronic central control unit to count the sheets as the separating member moves in the vertical direction, and the insertion region, where the separating member is inserted inside the stack, are distinct regions located a given distance apart.

[0006] Consequently, the unit only operates correctly, i.e. the insertion region is only positioned correctly at the last sheet in the ream to be removed, when the sheets have a perfectly flat profile. Conversely, in the event of an undulated sheet profile, the separating member may be inserted inside the stack at a sheet other than the one counted as the last sheet in the ream at the scanning region, and so remove a ream comprising more or fewer than the correct number of sheets.

[0007] It is an object of the present invention to provide a unit for selecting and separating reams from a stack of sheets of paper or similar, designed to eliminate the aforementioned drawbacks, and which is cheap and easy to produce.

[0008] According to the present invention, there is provided a unit for selecting and separating reams from a stack of sheets of paper or similar, as claimed in Claim 1.

[0009] A non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which:

Figure 1 shows a schematic view in perspective, with parts removed for clarity, of a preferred embodiment of the unit according to the present invention;

Figure 2 shows a first schematic side view, with parts removed for clarity, of the Figure 1 unit;

Figure 3 shows a second schematic side view, with parts removed for clarity, of the Figure 1 unit.

[0010] Number 1 in the accompanying drawings indicates as a whole a unit for selecting and separating reams 2 from a stack 3 of sheets 4 supported on a pallet 5 and comprising a number of sheets 4 stacked in a vertical direction 6.

[0011] Unit 1 comprises an optical image-acquisition device 7 positioned facing a front face 8 of stack 3, and in turn comprising a first slide (not shown) movable in direction 6; a second slide (not shown) connected in known manner to the first slide (not shown) to move linearly in a horizontal direction 9 crosswise to direction 6; and a television camera 10 mounted on the second slide (not shown), having an optical axis 11 parallel to direction 9, and for covering a given portion of face 8.

[0012] By moving television camera 10 in direction 6, the portion of face 8 covered by television camera 10 can be varied to define, on face 8, a given scanning region 12 which can be illuminated by a light source 13.

[0013] In connection with the above, it should be pointed out that, in the example shown, direction 9 and, therefore, axis 11 form an angle a of other than 0° with a horizontal direction 14 perpendicular to face 8, which, unless otherwise stated, will be considered a flat face parallel to direction 6.

[0014] Unit 1 also comprises a separating device 15 for separating reams 2 from stack 3, and which in turn comprises a first slide (not shown) movable in direction 6; a second slide (not shown) connected in known manner to the first slide (not shown) to move linearly in direction 14; and a separating member 16 mounted on the second slide (not shown).

[0015] Member 16 is defined by a substantially flat, wedge-shaped blade 17 which is inserted inside stack 3 at a substantially spot-shaped insertion region 18 lying in scanning region 12 of television camera 10, and whose location on face 8 is indicated, when blade 17 is located a given distance from face 8, by a laser pointing device 19 integral with member 16 and for illuminating a portion of face 8 coincident with region 18.

[0016] In actual use, television camera 10 is moved in direction 6 to acquire, within scanning region 12, the images of a number of sheets 4 normally approximating in excess the number of sheets 4 in a ream 2. The images acquired by television camera 10 are used by an electronic central control unit 20 to control the movement of blade 17 and, therefore, of insertion region 18 in direction 6, to count sheets 4 as blade 17 moves in direction 6, and to arrest blade 17 in direction 6 once blade 17 is positioned at the last sheet 4 in the ream 2 to be selected and removed.

[0017] At this point, blade 17 is moved in direction 14 and inserted inside stack 3 at region 18 to separate the ream 2 considered from stack 3.

[0018] Since television camera 10 and blade 17 are so oriented with respect to each other that insertion region 18 lies in scanning region 12, insertion region 18 is always located within the portion of face 8 covered by television camera 10. Consequently, when blade 17 is arrested in direction 6, insertion region 18 is always located correctly at the last sheet 4 in the ream 2 to be removed, regardless of the shape of sheets 4, i.e. regardless of whether the profile of sheets 4 is perfectly flat or undulated.

[0019] Since face 8 may possibly be undulated, i.e. other than perfectly flat, central control unit 20 also provides, as television camera 10 moves in direction 6, for continuously feedback-controlling the movement of television camera 10 in direction 9 in response to a signal from a distance sensor 21 integral with television camera 10. Moving television camera 10 in direction 9 provides for maintaining a substantially constant distance, measured parallel to direction 9, between face 8 and television camera 10, and so enabling television camera 10 to acquire correct images of region 12, i.e. to correctly focus the images of region 12.

[0020] Obviously, in variations not shown:

television camera 10 and blade 17 may be oriented with respect to each other in any manner capable of ensuring insertion region 18 lies in scanning region 12;

television camera 10 is fixed in direction 6, and stack 3 is movable in direction 6;

television camera 10 is mounted to scan sheets 4 by oscillating about a given axis of rotation; and

television camera 10 is replaced by a laser sensor for determining a profile of sheets 4 in stack 3 at scanning region 12.

Claims

1. A unit for selecting and separating reams (2) from a stack (3) of sheets (4) of paper or similar; the stack (3) comprising a number of sheets (4) stacked in a given direction (6), and having a front face (8) substantially parallel to said direction (6); the unit comprising information-acquisition optical means (10) facing the front face (8); actuating means for moving the stack (3) and the optical means (10) with respect to each other, to permit acquisition by the optical means (10) of information relative to the sheets (4) at a given scanning region (12); separating means (16) which are inserted inside the stack (3) at a given insertion region (18) to separate a ream (2) from the stack (3); and logic control means (20) for counting a number of sheets (4) in said scanning region (12), and for controlling movement of the insertion region (18) in said direction (6) as a function of the number of sheets (4) counted by means of the information acquired by said optical means (10); and being characterized in that the optical means (10) and the separating means (16) are so oriented with respect to each other that the insertion region (18) lies in the scanning region (12).

2. A unit as claimed in Claim 1, wherein the optical means (10) have a given optical axis (11), and detecting means (21) for continuously determining, during acquisition of the information, a distance, measured parallel to the optical axis (11), between the optical means (10) and the front face (8); the actuating means moving the optical means (10) parallel to the optical axis (11) in response to a signal from said detecting means (21), so as to maintain said distance substantially constant.

3. A unit as claimed in Claim 1 or 2, and also comprising a pointing device (19) for indicating the location of said insertion region (18) in said direction (6); the logic control means (20) controlling movement of said separating means (16) in said direction (6) as a function of a signal from the pointing device (19).

4. A unit as claimed in any one of the foregoing Claims, and also comprising lighting means (13) for illuminating said scanning region (12).

5. A unit as claimed in any one of the foregoing Claims, wherein the optical means (10) have an optical axis (11) at an angle of other than 90° with respect to said front face.

6. A unit as claimed in any one of Claims 1 to 4, wherein the optical means (10) have an optical axis (11) at an angle of substantially 90° with respect to said front face.

7. A unit as claimed in any one of the foregoing Claims, wherein the optical means (10) comprise a television camera (10) for acquiring an image of the sheets (4) in the stack (3) at said scanning region (12).

8. A unit as claimed in any one of Claims 1 to 6, wherein the optical means (10) comprise a laser sensor for determining a profile of the sheets (4) in the stack (3) at the scanning region (12).

9. A unit for selecting and separating reams (2) from a stack (3) of sheets (4) of paper or similar; the stack (3) comprising a number of sheets (4) stacked in a given direction (6), and having a front face (8) substantially parallel to said direction (6); the unit comprising information-acquisition optical means (10) facing the front face (8) and having a given optical axis (11); actuating means for moving the stack (3) and the optical means (10) with respect to each other, to permit acquisition by the optical means (10) of information relative to the sheets (4) at a given scanning region (12); separating means (16) which are inserted inside the stack (3) at a given insertion region (18) to separate a ream (2) from the stack (3); and logic control means (20) for counting a number of sheets (4) in said scanning region (12), and for controlling movement of the insertion region (18) in said direction (6) as a function of the number of sheets (4) counted by means of the information acquired by said optical means (10); and being characterized by also comprising detecting means (21) for continuously determining, during acquisition of the information, a distance, measured parallel to the optical axis (11), between the optical means (10) and the front face (8); the actuating means moving the optical means (10) parallel to the optical axis (11) in response to a signal from said detecting means (21), so as to maintain said distance substantially constant.

Drawing