US3741058A

US3741058A - Apparatus for cutting sheet material

Info

Publication number: US3741058A
Application number: US00044146A
Authority: US
Inventors: I Fish
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-06-08
Filing date: 1970-06-08
Publication date: 1973-06-26
Anticipated expiration: 1990-06-26

Abstract

Pieces of sheet material are picked up one at a time off a stack by suction means and each one is pulled to a mechanism which clamps it and cuts a straight edge on it and is then pulled further before the same mechanism clamps it and cuts another straight edge on it parallel to the first. As an alternative, an end of a continuous web of sheet material is pulled to a mechanism which clamps it and cuts pieces off it. In both cases, if desired each piece may proceed directly to apparatus which cuts two more straight edges on it so that the sheet is then a true rectangle.

Description

United States Patent 1191 Fish 1 June 26, 1973 APPARATUS FOR CUTTING SHEET 693,099 2/1902 Bayler 83/277 x MATERIAL 1,665,209 4/1928 Huston 83/35 [76] Inventor: Ian Anthony Fish, 8, Handel Close, Primary Examiner Andrew R Juhasz Canons Dnve Edgware England Assistant Examiner-Leon Gilden [22] Filed: June 8, 1970 Att0rney-Waters, Roditi, Schwartz & Nissen 21 A 1. No.: 44 146 1 pp 57 ABSTRACT Pieces of sheet material are picked up one at a time off [52] US. Cl 83/277, 83/281, 8834/2413)? a Stack y suction means and each one is pulled to a mechanism which clamps it and cuts a straight edge on [51] Int. Cl B2611 5/20 d th df rth b f th h [58] Field of Search 83/277, 281, 282, 1 e 6 6 Same amsm 83/404 402 925 35 36 clamps it and cuts another straight edge on it parallel to the first. As an alternative, an end of a continuous web of sheet material is pulled to a mechanism which [56] References Cned clamps it and cuts pieces off it. In both cases, if desired UNITED STATES PATENTS each piece may proceed directly to apparatus which 2,562,938 8/l95l Moyer 83/255 cuts two more traight edges on it so that the heet is 2,562,950 8 1951 Roessl et al 83/255 then a true rectangm 1,261,310 4/1918 Smith 83/277 1,475,802 11/1923 Dovman...-. 83/277 17 Claims, 2 Drawing Figures Patented June 26, 1973 3,741,058

2 Sheets-Sheet 1 FIG.|

011 gym APPARATUS FOR CUTTING SHEET MATERIAL DESCRIPTION OF THE INVENTION It is an object of the invention to provide convenient apparatus for cutting sheet material, for example cardboard, which is initially either in a stack of individual 'pieces or is a continuous web, for example a web formed into a roll.

The invention consists of apparatus having the features specified in any one of the appended claims.

Preferably, at least some of the movements of the apparatus are produced by operation of fluid-pressure actuated devices. At least one of the movements may be produced by electrically energizing or de-energizing a coil and by operation of a fluid-pressure actuated device controlled by the coil. At least one more of the movements may be produced directly by electrically energizing or de-energizing a coil, i.e. without a fluidpressure actuated device being used. At least one more of the movements may be produced by the operation of a fluidpressure actuated device, without a coil being used.

The fluid-pressure actuated devices are preferably simple piston-and-cylinder arrangements, and they may be operated pneumatically or hydraulically.

An example in accordance with the invention is described below with reference to the accompanying drawings in which FIG. 1 diagrammatically shows a plan view of a sheet material cutting machine comprising a first apparatus for producing two parallel straight cut edges on each of a stack of pieces of cardboard and a second apparatus for producing on each piece two more straight and parallel cut edges perpendicular to the two produced by the first apparatus, and

FIG. 2 shows in greater detail a plan view of the first apparatus and part of the second apparatus.

FIG. 1 shows a first apparatus comprising a guillotine having a fixed blade 1 and a moving blade 2 which is carried by a support 3 having means (not shown) for raising it and subsequently lowering it to cut a straight edge on sheet material. On one side of the guillotine there are provided suction means (not shown in detail) carried by a tube 4 for lifting with the aid of suction theupper piece 5 .of sheet material from a stack of such pieces. In the zone between the guillotine and the suction means, there are a fixed clamping member6 and a moving clamping member 7 above it which can be raised and can subsequently be lowered so that a piece of sheet material taken from the stack is clamped between it and the fixed clamping member 6. Gripping means 8.for gripping an edge region of the piece 5 of sheet material after it has been lifted are represented merely by a rectangle and arrows 9 and indicate the directions in which the gripping means are displaced by displacing means (not shown in FIG. 1 These displacing means, in the process of cutting one piece of sheet material, move the gripping means 8 in the direction of the arrow 9 between the blades 1 and 2 and between the clamping members 6 and 7 to an edge-gripping position, then in the direction of the arrow 10 between the clamping members 6 and 7 and between and beyond the blades 1 and 2 and then in the direction of the arrow 9 between the blades 1 and 2 and then again in the direction of the arrow 10 between and beyond the blades. In the edge-grippingposition attained by the first movement in the direction of the arrow 9, the gripping means 8 are able to close upon the edge region of the piece 5 of sheet material after the latter has been lifted. Each of the first and second movements of the gripping means 8 in the direction of the arrow 10 must take the gripping means out of the range of action of the guillotine. The second movement of the gripping means 8 in the direction of the arrow 9 must take the gripping means to a position where it can grip the already cut edge region of piece 5. Another rectangle represents adjustable means in the form of an adjustable stop 11 for limiting to an adjustable distance the second movement of the gripping means 8 in the direction of the arrow 10.

The first apparatus also includes control means (not shown in FIG. 1) constructed to cause:

a. the gripping means 8 in the edge-gripping position to grip that edge region of the lifted piece 5 of sheet material that is nearest the guillotine,

b. the clamping members 6 and 7 to clamp the lifted piece 5 and the gripping means 8 to release it before the end of the first movement of the gripping means 8 in the direction of the arrow '10 (in the example illustrated this first movement of the gripping means 8 in the direction of the arrow 10 is effected in two stages by two different mechanisms, one of which acts before the just-mentioned clamping and releasing and the other acting after this clampingand releasing),

c. operation of the guillotine after the clamping and releasing mentioned under (b) above (and after the gripping means has moved clear) whereby the lifted piece 5 is given a straight cut edge,

d. the gripping means 8 to grip the newly cut edge region of the lifted piece 5 of sheet material and the clamping members 6 and 7 to release that piece after operation of the guillotine and the second movement of the gripping means 8 in the direction of the arrow 9,

e. the clamping members 6 and 7 toclamp the lifted piece 5 of sheet material after the second movement of the gripping means 8 in the direction of the arrow 10 (in the illustrated example this clamping is effected when the second movement of the gripping means 8 in the direction of the arrow 10 has been completed),

f. the guillotine then to operate again whereby the lifted piece 5 of sheet material is given a second straight cut edge parallel to the first and spaced from it by a distance which depends upon the adjustment of the Ste 1 1 i A useful embodiment of the invention comprises, in essence, just what has been described above with reference to FIG. 1. However FIG. 1 shows a second and similar apparatus for producing on the lifted piece 5 of sheet material two more straight and parallel cut edges perpendicular to the two produced by the blades 1 and 2 of the first apparatus. The control means of the first apparatus serves to cause the lifted piece 5 of sheet material to be free of the gripping means 8 and the clamping members 6 and 7 after the second operation of the guillotine having'the blades land 2 The second apparatus comprises a clamping device 12 for clamping the lifted piece of sheet material whilst the guillotine hav ing the blades 1 and 2 is operating the second time and

parts

1A, 2A, 3A, 6A, 7A, 8A and 11A which corresponds to the

parts

1, 2, 3, 6, 7, 8xand 11 and operate in a similar manner to them.

Theblades

1A and 2A of the second apparatus are perpendicular to the blades 1 and 2 so that the sheet after being cut twice by them is a true rectangle the dimensions of which depend upon the positions of the stops 11 and 11A. The gripping means 8A move in the directions of the arrows 9A and A. The

clamping members

6A and 7A are between the second guillotine and the clamping device 12.

In FIG. 2 parts corresponding to those shown in FIG. 1 have the same reference numerals. FIG. 2 shows substantially rectangular cardboard blanks arranged in a stack, the top one being referenced 5. The blanks are lifted one at a time by suckers mounted on the tube 4. Suction is applied to the suckers when appropriate under the control of a solenoid (not shown) and the tube 4 is lowered simultaneously and then raised, with a blank, under the control of a solenoid S2. A bar 13 sliding on rails 14, and mounted on a rod attached to the piston of a piston and cylinder arrangement 16, moves, from a position to the left of the illustrated position, towards the raised blank upon operation of the arrangement 16, which coincides with the lowering of the tube 4, and carries with it grippers 17, which are in an opened condition before reaching the raised blank. The grippers 17 are mounted on a frame 18 which can be moved in the directions of the

arrows

9 and 10 with respect to the bar 13 by operation of a solenoid S6. The movement of the bar 13 is halted when it encounters a buffered (i.e. spring-biased) stop BS1. Then a solenoid S5 operates, which makes the grippers 17 close upon the near edge of the raised blank. At the same time, a buffered stop BS4 is raised from a lowered position by operation of another solenoid (not shown) and the application of suction to the tube 4 is discontinued. The bar 13 is then partly retracted by operation of the piston and cylinder arrangement 16 until the leading edge of the blank has just passed between the clamping members 6 and 7, which are then in an open condition (member 7 raised), and between the fixed blade 1 and the moving blade 2, which is then in a raised position, and until the bar 13 has struck the buffered stop BS4. The clamping member 7 is then lowered under the control of two solenoids not shown, the-buffered stop BS4 is simultaneously lowered again and the grippers 17 are simultaneously released from the blank by operation of the solenoid S5 and then withdrawn a little to the right in response to actuation of the solenoid S6. The upper blade 2 then descends and rises again so that the leading edge of the blank is trimmed, then the grippers 17 are moved back and closed upon the blank by operation of the solenoids S6 and S5, then the clamping member 7is raised and simultaneously the clamping device 12 is moved, by operation of a solenoid S7, towards the rod 15 to a position where the near side of the blank will pass beneath it when the blank moves to the right and then the bar 13 and the grippers 17 are moved further to the right, as a result of operation of the piston and cylinder arrangement 16, until the bar 13 strikes a buffered stop BS3 and the operating member of a micro-switch 19, both of which are carried by a movable carrier member 20, and then operation of the piston and cylinder arrangement 16 is abruptly halted, when the bar 13 is in a position determined by the position of the carrier member 20. This carrier member can be moved to the left and to the right by an electric motor which is controlled from a central control console and turns a screw 21 upon which the carrier member is mounted. When the bar 13 has ceased to move to the right, the clamping device 12 is lowered, by operation of a solenoid S8, so that the blank is gripped between it and a lower clamp member not shown and the clamping member 7 is simultaneously lowered to clamp the blank. Then the grippers 17 are opened and the upper blade 2 descends and then rises again so that the blank is cut again and now has two parallel opposite edges. Then, when the clamping member 7 has been raised and the clamping device 12 has also been raised, the blank is moved perpendicularly away from the rod 15 to have its leading edge trimmed, and another cut made subsequently, by the

blades

1A and 2A. The blank is now a true rectangle. Also, the piston and cylinder arrangement 16 operates to move the bar 13, and with it the grippers 17 to the left, until this movement is halted by the bar 13 striking a buffered stop BS2, the-guillotine having blades 1 and 2 then being in the initial condition and ready to deal with another blank.

The part 6 shown in the drawings is a discernible clamping member fixed to the bed of the machine. Since, however, it is fixed, it could be dispensed with and a part of the bed itself could serve as the lower clamping member cooperating with the upper clamping member 7. Another possibility is for the lower clamping member to be a member separate from the bed and vertically movable with respect to it and for the upper clamping member to be vertically movable with respect to both the lower clamping member and the bed. Thus the two clamping members could move as follows: they are in their lowermost positions when the cardboard is clamped between them and is in contact with the fixed blade 1 and is actually being cut, after which they are raised simultaneously so that the cardboard remains clamped between them for a short time but is above the fixed blade 1, after which the lower clamping member is lowered and the upper one is raised to free the cardboard for further movement. A further solenoid in that case brings about the movement of the lower clamping member. All these remarks also apply to the

parts

6A and 7A.

The apparatus comprising the parts 1 to 3, 6 to 8 and 11 of FIG. 1 or the machine comprising that apparatus and the

parts

12, 1A to 3A, 7A to 9A and 11A of FIG. 1 could be used to cut pieces from a continuous web of sheet material, for example a web formed into a roll. In that case, the suction means and the tube 4 will be dispensed with and instead there will be, on one side of the guillotine having blades 1 and 2, means for supporting the continuous web of sheet material and for feeding an end of it towards that guillotine. The other parts and their mode of operation could be as described above but there could be the modification that the gripping means 8 never passes between the clamping members 6 and 7. Also, since when the blade 2 descends to separate a piece from the web it not only cuts a straight edge on the trailing side of that piece but also cuts a straight edge on the leading end of what is left of the web, there will in most cases be no need for the leading end of what is left of the web to be trimmed again before separating the next piece from the web. In other words, for each piece separated from the web, it will in most cases be enough for the gripping means 8 to move once to the left between the blades 1 and 2, and possibly between the clamping members 6 and 7, to an edgegripping position and then once to the right between and beyond the blades 1 and 2 to a sufficient extent, determined by the stop 11, having regard to the desired width to be cut from the web, and for the gipping means when in the edge-gripping position to grip the edge region at the leading end of the web, the clamping members to clamp the web after the movement of the gripping means to the right and the blade 2 then to descend to separate the piece from the web. If the

parts

12, 1A to 3A, 6A to 8A and 11A are provided, they will be and will function as described previously.

In the examples described above, the pieces 5 of sheet material shown in the drawings and the pieces cut from the web in the modified apparatus, described above but not illustrated, are each large enough to produce only one blank of the desired final size, which may for example subsequently be used to make a box. However it is possible for the same apparatus, but without the clamping device 12, to be used in such a way that the guillotine having the blades 1 and 2 cuts a series of pieces from a sheet of material, which may be separated from a stack of such pieces or be in the form of a continuous web, for example in a roll, and these pieces proceed in turn to the guillotine having the

blades

1A and 2A, which cuts a series of blanks from each of them. The sequence of operations of the apparatus shown in FIG. 1 may then, for example, be:

a. the gripping means 8 moves in the direction of the arrow 9 to an edge-gripping position and there grip an edge region of the sheet of material,

b. the gripping means 8 moves in the direction of the arrow with said edge region,

c. the clamping members 6 and 7 clamp the sheet and the blade 2 descends to cut a first piece from it,

(1. the gripping means 8A moves in the direction of the arrow 9A and grips an edge region of this first piece,

e. the gripping means 8A moves in the direction of the arrow 10A and pulls the first piece between the

blades

1A and 2A until halted by a stop and the

clamping members

6A and 7A clamp it and the blade 2A descends to cut it, i.e. to make a trimming cut to remove a section which is smaller than theblanks' that are to be produced, 1

f. the gripping means 8A move again in the direction of the arrow 9A and grip the newly cut edge region of the first piece of sheet material and the

clamping members

6A and 7A release it and the gripping means 8A move again in the direction of the arrow 10A to pull the first piece between the

blades

1A and 2A and then the

clamping members

6A and 7A clamp this piece and the blade 2A descends to cut it, to produce the first blank of the desired size,

g. the movements (f) are repeated to produce a number of similar blanks from the first piece, and

h. subsequent pieces are cut from the sheet by the blades 1 and 2 and themselves out up by the

blades

1A and 2A in the manner described above.

In order to permit adjustment of the dimensions of the blanks produced, there are means (adjustable stop BS3) for adjusting the extent of the movement (b) of the gripping means 8 in the direction of the arrow 10 and means (another adjustable stop, not shown) for adjusting the extent of the movement (in (f) of the gripping means 8A in the direction of the arrow 10A.

If desired, there may also be employed the stop BS4 which stops movement of the sheet of material in the direction of the arrow 10 for a trimming cut to be made by the blades 1 and 2 whereby there is removed from the sheet before any one of the full-size pieces a section which is smaller than any of the pieces.

If, in performance of stage (h), what is left of the sheet of material is too narrow in the direction of the arrow 9 for it to be cut up to make full-size blanks, so that it does not reach the blades 1 and 2 when it has been moved in the direction of the arrow 10, this portion of the sheet is prevented from reaching the

blades

1A and 2A by means responsive to signals produced by a light-operated device adjacent the blades 1 and 2. The light-operated device is a photo-cell which cooperates with means for generating a beam of light which falls on the photo-cell if, and only if, there is no sheet material between the light-generating means and the photo-cell. Then the signal produced by the photocell is received by-a solenoid S10, which responds to the signal by causing a horizontal ejector bar 22 to be lowered. The bar 22 has a number of vertical tines 23 depending from it between adjacent ones of the grippers 17. The grippers 17 are then opened and moved to the right by operation of the solenoids S5 and S6 and the tines prevent the undersized piece from moving to the right with the grippers and the piece falls into a recess 24 instead of proceeding to the second guillotine. The solenoid S6 then operates to return the grippers 17 to their former positions.

I claim 1. Apparatus for cutting sheet material comprising a guillotine having two blades, suction means on one side of the guillotine for lifting with the aid of suction the upper piece of sheet material from a stack of such pieces, two co-operating clamping members adjacent the guillotine in the zone between the guillotine and the suction means, gripping means for gripping an edge region of the lifted piece of sheet material, displacing means for moving said gripping means in one direction between the blades and between said clamping mem bers to an edge-gripping position and then in the reverse direction between said clamping members and between and beyond the blades and then in said one direction between the blades and then again in said reverse direction between and beyond the blades, adjustable means for limiting to an adjustable distance the second movement of said gripping means in said reverse direction, and control means for causing:

a. said gripping means in said edge-gripping position to grip that edge of the lifted piece of sheet material that is nearest the guillotine,

b. said clamping members to clamp the lifted piece of sheet material and said gripping means to release it before the end of the first movement of said gripping means in said reverse direction,

c. operation of the guillotine after that clamping and releasing whereby the lifted piece of sheet material is given a straight out edge,

d. said gripping means to gripthe newly cut edge of the lifted piece of sheet material and said clamping members to release that piece after operation of the guillotine and the second movement of said gripping means in said one direction,

e. said clamping members to clamp the lifted piece of sheet material after further movement of said gripping means in said reverse direction and f. the guillotine then to operate again whereby the lifted piece of sheet material is given a second straight out edge parallel to the first.

2. A sheet material cutting machine comprising a first apparatus according to claim 1 and a second apparatus for producing on the lifted piece of sheet material two more straight and parallel cut edges perpendicular to the two produced by said first apparatus, said control means of said first apparatus serving to cause the lifted piece of sheet material to be free of said gripping means and said clamping members after the second operation of the guillotine and said second apparatus comprising a clamping device for clamping the lifted piece of sheet material whilst the guillotine is operating the second time, a second guillotine having two blades perpendicular to the blades of the first apparatus, two further cooperating clamping members adjacent the second guillotine between the second guillotine and said clamping device, second gripping means for gripping an edge region of the lifted piece of sheet material, second displacing means for moving said second gripping means in a forward direction perpendicular to said one direction between the blades of the second guillotine and between said further clamping members to a second edgegripping position and then in the opposite direction between said further clamping members and between and beyond the blades of the second guillotine and then in said forward direction between the blades of the second guillotine and then again in said opposite direction between and beyond the blades of the second guillotine, second adjustable means for limiting to an adjustable distance the second movement of said second gripping means in said opposite direction, and second control means for causing:

a. said second gripping means in said second edgegripping position to grip that edge of the lifted piece of sheet material that is nearest the second guillotine,

b. said further clamping members to clamp the lifted piece of sheet material and said second gripping means to release it before the end of the first movement of said second gripping means in said opposite direction,

0. operation of the second guillotine after that clamping and releasing whereby the lifted piece of sheet material is given a straight cut edge perpendicular to the straight out edges produced by the guillotine of the first apparatus,

said second gripping means to grip the newly cut edge' of the lifted piece of sheet material and said further clamping members to release that piece after operation of the second guillotine and the second movement of said second gripping means in said forward direction,

e. said further clamping members to clamp the lifted piece of sheet material after further movement of said second gripping means in said opposite direction and f. the second guillotine then to operate again whereby the lifted piece of sheet material is given a second straight cut edge parallel to the first straight out edge produced by the second guillotine.

3. A machine according to claim 2 comprising means for ensuring that when the piece of sheet material, after said gripping means has been moved in said reverse direction for the second time, does not reach the guillotine of the first apparatus, said piece is prevented from reaching the second apparatus.

4. A machine according to claim 3 in which the means recited in claim 3 includes a light-operated device adjacent the guillotine of the first apparatus for is suing a signal when the piece of sheet material, after said gripping means has been moved in said reverse direction for the second time, does not reach this guillotine and means responsive to said signal for preventing said piece from reaching the second apparatus.

5. A sheet material cutting machine comprising a first apparatus for cutting sheet material comprising a guillotine having two blades, means on one side of the guillotine for supporting a web of sheet material and for feeding one end of it towards the guillotine, two cooperating clamping members adjacent the guillotine on the side thereof from which said end approaches the guillotine, gripping means for gripping an edge region of the web at said end of the web, displacing means for moving said gripping means in one direction between the blades to an edge-gripping position and subsequently in the reverse direction between and beyond the blades, adjustable means for limiting to an adjustable distance said movement of the gripping means in said reverse direction and control means forcausing:

a. said gripping means in said edge-gripping position to grip said edge region of the web,

b. said clamping members to clamp the web after said movement of said gripping means in the reverse direction has been halted by said adjustable means,

c. the guillotine then to operate whereby there is separated from the web a piece of sheet material having a straight trailing edge, and

d. the separated piece of sheet material to be free of said gripping means and said clamping members after said operation of the guillotine, said machine further comprising a second apparatus for producing on the separated piece of sheet material two more straight and parallel cut edges perpendicular to the said trailing edge, said second apparatus comprising a clamping device for clamping during said operation of the guillotine the part of the sheet material which becomes said separated piece of sheet material as a result of said operation of the guillotine, a second guillotine having two blades perpendicular to the blades of the first apparatus, two further co-operating clamping members adjacent the second guillotine between the second guillotine and said clamping device, second gripping means for gripping an edge region of the separated piece of sheet material, second displacing means for moving said second gripping means in a forward direction perpendicular ,to said one direction between the blades of the second guillotine and between said further clamping members to a second edge-gripping position and then in the opposite direction between said further clamping members and between and beyond the blades of the second guillotine and then in said forward direction between the blades of the second guillotine and then again in said opposite direction between and beyond the blades of the second guillotine, second adjustable means for limiting to an adjustable distance the second movement of said second gripping means in said opposite direction, and second control means for causing:

e. said second gripping means in said second edgegripping position to grip that edge region of the separated piece of sheet material that is nearest the second guillotine,

f. said further clamping members to clamp the separated piece of sheet material and said second gripping means to release it when the second gripping means has moved the first time in said opposite direction g. operation of the second guillotine after that clamping whereby the separated piece of sheet material is given a straight out edge perpendicular to said trailing edge,

h. said second gripping means to grip the newly cut edge region of the separated piece of sheet material and said further clamping members to release that piece after operation of the second guillotine and the second movement of said second gripping means in said forward direction,

. said further clamping members to clamp the separated piece of sheet material after the second movement of said second gripping means in said opposite direction and the second guillotine then to operate again whereby the separated piece of sheet material is given a second straight cut edge parallel to the first straight cut edge produced by the second guillotine.

6. A machine according to claim in which saidfirst apparatus includes stop means for limiting movement of the gripping means in said reverse direction and said control means causes, before operation (a), said gripping means in said edge-gripping position togrip an edge region of the web at said end of the web, said clamping members to clamp the web after movement of said gripping means in the reverse direction is stopped by said stop means when said gripping means has moved an amount smaller than the distance it moves between operation (a) and (b), and then operation of the guillotine to remove from the web a portion that is narrower than the piece which is subsequently separated from the web in operation (c).

7. Apparatus for cutting sheet material comprising a guillotine having two blades, means near the guillotine for separating a piece of sheet material from a stack of such pieces, two co-operatingclamping members adjacent the guillotine in the zone betwe'en the guillotine and the separating means, gripping means for gripping an edge region of the separated piece of sheet material, displacing means for moving saidgripping means in one direction between the blades and between said clamping members to an edge-gripping position and then in the reverse direction between said clamping members and between and beyond the blades and then in said one direction between the blades and then again in said reverse direction between and beyond the blades, ad justable means for limiting to an adjustable distance the second movement of said gripping means in said reverse direction, and control means for causing:

a. said gripping means in said edge-gripping position to grip that edge region of the separated piece of sheet material that is nearest the guillotine,

b. said clamping members to clamp the separated piece of sheet material when said gripping means has moved the first time in said reverse direction 0. operation of the guillotine after that clamping whereby the separated piece of sheet material is given a straight cut edge,

d. said gripping means to grip the newly cut edge region of the separated piece of sheet material and said clamping members to release that piece after operation of the guillotine and the second movement of said gripping means in said one direction.

e. said clamping members to clamp the separated piece of sheet material after the second movement of said gripping means in said reverse direction and f. the guillotine then to operate again whereby the separated piece of sheet material is given a second straight cut edge parallel to the first.

8. A sheet material cutting machine comprising a first apparatus according to claim 7 and a second apparatus for producing on the separated piece of sheet material two more straight and parallel cut edges perpendicular to the two produced by said first apparatus, said control means of said first apparatus serving to cause the separated piece of sheet material to be free of said gripping means and said clamping members after the second operation of the guillotine and said second apparatus comprising a clamping device for clamping the separated piece of sheet material whilst the guillotine is op- .erating the second time, a second guillotine having two blades perpendicular to the blades of the first apparatus, two further co-operating clamping members adjacent the second guillotine between the second guillotine and said clamping device, second gripping means for gripping an edge region of the separated piece of sheet material, second displacing means for moving said second gripping means in a forward direction perpendicular to said one direction between the blades of the second guillotine and between said further clamping members to a second edge-gripping position and then in the opposite direction between said further clamping members and between and beyond the blades of the second guillotine and then in said forward direction between the blades of the second guillotine and then again in said opposite direction between and beyond the blades of the second guillotine, second adjustable means for limiting to an adjustable distance the second movement of said second gripping means in said opposite direction, and second control means for causing:

a. said second gripping means in said second edgegripping position to grip that edge region of the separated piece of sheet material that is nearest the second guillotine, I

b. said further clamping members to clamp the separated piece of sheet material and said second gripping means to release it when said second gripping means has moved the first time in said opposite direction c. operation of the second guillotine after that clamping whereby the separated piece of sheet material is given a straight cut edge perpendicular to the straight cut edges produced by the guillotine of the first apparatus,

d. said second gripping means to grip the newly cut edge region of the separated piece of sheet material and said further clamping members to release that piece after operation of the second guillotine and the second movement of said second gripping means in said forward direction,

e. said further clamping members to clamp the separated piece of sheet material after the second movement of said second gripping means in said opposite direction and f. the second guillotine then to operate again whereby the separated piece of sheet material is given a second straight cut edge parallel to the first straight cut edge produced by the second guillotine.

9. A machine according to claim 7 in which said separating means separate with the aid of suction the upper piece of sheet material from the stack of such pieces.

A machine according to claim 7 in which between the movement (b) and the following movement (c) the gripping means moves in said reverse direction after releasing the piece of sheet material.

11. Apparatus for cutting blanks from a sheet of material including first and second guillotines set at an angle to one another and means for operating them and conveying material to them so that the first guillotine cuts a series of pieces from the sheet and these pieces proceed in turn to the second guillotine which cuts a series of blanks from each of them, said means comprising two co-operating first clamping members adjacent the first guillotine, first gripping means for gripping an edge region of the sheet material, two cooperating second clamping members adjacent the second guillotine, second gripping means for gripping an edge region of the sheet material and control means for causing:

a. the first gripping means to move in one direction to an edge-gripping position and there to grip an edge region of the sheet of material,

b. the first gripping means to move in the reverse direction with said edge region,

c. the first clamping members to clamp the sheet and the first guillotine then to operate to cut a first piece from it,

d. the second gripping means to move in a forward direction and then to grip an edge region of said first piece,

e. the second gripping means to move in the opposite direction to pull said first piece between the blades of the second guillotine and the second clamping members then to clamp this piece and the second guillotine then to cut it,

f. the second gripping means to move again in said forward direction and then to grip the newly cut edge region of said first piece and the second clamping members to release this piece and then the second gripping means to move again in said opposite direction to pull said first piece between the blades of the second guillotine and then the second clamping members to clamp this piece and the second guillotine to cut it,

g. the movement (f) to be repeated to produce a plurality of similar blanks from the first piece, and

h. subsequent pieces to be cut from said sheet by the first guillotine and themselves cut up by the second guillotine in the same way, the apparatus further comprising means for adjusting the extent of the movement (b) of the first gripping means in said reverse direction and means for adjusting the extent of the movement in (f) of the second gripping means in said opposite direction whereby the dimensions of the blanks produced can be adjusted.

12. Apparatus according to claim 11 comprising means for ensuring that when in the performance of stage (h) what is left of said sheet of material does not reach the blades of the first guillotine when it is moved in said reverse direction by said first gripping means it is prevented from reaching the second guillotine.

13. Apparatus according to claim 12 in which the means recited in claim 22 includes a light-operated device adjacent the blades of the first guillotine for issuing a signal when what is left of said sheet of material, after said first gripping means has been moved in said reverse direction, does not reach these blades and means responsive to said signal for preventing it from reaching the second guillotine.

14. Apparatus according to claim 12 having a recess into which falls the piece which is prevented from reaching the second guillotine as aforesaid.

15. Apparatus for cutting blanks from a sheet of material including first and second guillotines set at an angle to one another and means for operating them and conveying material to them so that the first guillotine cuts a series of pieces from the sheet and these pieces proceed in turn to the second guillotine which cuts a series of blanks from each of them, said means comprising clamping members adjacent the blades of the first guillotine for clamping the sheet whilst it is being cut by that guillotine, an adjustable stop for halting the movement of said sheet as it is conveyed to the first guillotine and thereby controlling the width, transverse to the cut it produces, of the piece cut from the sheet by the first guillotine, further clamping members adjacent the blades of the second guillotine for clamping each piece whilst it is being cut by that guillotine, a stop for stopping movement of each piece for a trimming cut to be made by the second guillotine whereby there is removed from the piece before any blank a section which is smaller than one of the blanks and an adjustable stop for halting the movement of each piece and thereby controlling the width, transverse to the cut it produces, of the blanks cut from each piece by the second guillotine.

16. Apparatus according to claim 15 comprising a further stop for stopping movement of the sheet for a trimming cut to be made by the first guillotine whereby there is removed from the sheet before any of the said pieces a section which is smaller than one of the said pieces.

17. Apparatus for cutting sheet material comprising a guillotine having two blades, means near the guillotine for supporting sheet material, two cooperating clamping members adjacent the guillotine in the zone between the guillotine and the supporting means, gripping means for gripping an edge region of the sheet material, displacing means for moving said gripping means in one direction between the blades to an edgegripping position and subsequently in the reverse direction between and beyond the blades to a first stopping position and then in said one direction between the blades and then again in said reverse direction between and beyond the blades to a second stopping position, adjustable means for limiting to an adjustable distance the second movement of the gripping means in the reverse direction and control means for causing a. said gripping means in said edge gripping position to grip said edge region of the sheet material b. said clamping members to clamp the sheet after said first movement of said gripping means in the reverse direction to the first stopping position 0. the guillotine then to operate to give a trimming cut on the leading edge of sheet material (1. said gripping means to grip said edge region of the sheet in said edge gripping position after movement of said gripping means in said one direction c. said clamping members to clamp the sheet after said second movement of said gripping means in the reverse direction to the second stopping position f. the guillotine then to operate again whereby there is separated from the sheet a blank.

Claims

1. Apparatus for cutting sheet material comprising a guillotine having two blades, suction means on one side of the guillotine for lifting with the aid of Suction the upper piece of sheet material from a stack of such pieces, two co-operating clamping members adjacent the guillotine in the zone between the guillotine and the suction means, gripping means for gripping an edge region of the lifted piece of sheet material, displacing means for moving said gripping means in one direction between the blades and between said clamping members to an edge-gripping position and then in the reverse direction between said clamping members and between and beyond the blades and then in said one direction between the blades and then again in said reverse direction between and beyond the blades, adjustable means for limiting to an adjustable distance the second movement of said gripping means in said reverse direction, and control means for causing: a. said gripping means in said edge-gripping position to grip that edge of the lifted piece of sheet material that is nearest the guillotine, b. said clamping members to clamp the lifted piece of sheet material and said gripping means to release it before the end of the first movement of said gripping means in said reverse direction, c. operation of the guillotine after that clamping and releasing whereby the lifted piece of sheet material is given a straight cut edge, d. said gripping means to grip the newly cut edge of the lifted piece of sheet material and said clamping members to release that piece after operation of the guillotine and the second movement of said gripping means in said one direction, e. said clamping members to clamp the lifted piece of sheet material after further movement of said gripping means in said reverse direction and f. the guillotine then to operate again whereby the lifted piece of sheet material is given a second straight cut edge parallel to the first.

2. A sheet material cutting machine comprising a first apparatus according to claim 1 and a second apparatus for producing on the lifted piece of sheet material two more straight and parallel cut edges perpendicular to the two produced by said first apparatus, said control means of said first apparatus serving to cause the lifted piece of sheet material to be free of said gripping means and said clamping members after the second operation of the guillotine and said second apparatus comprising a clamping device for clamping the lifted piece of sheet material whilst the guillotine is operating the second time, a second guillotine having two blades perpendicular to the blades of the first apparatus, two further co-operating clamping members adjacent the second guillotine between the second guillotine and said clamping device, second gripping means for gripping an edge region of the lifted piece of sheet material, second displacing means for moving said second gripping means in a forward direction perpendicular to said one direction between the blades of the second guillotine and between said further clamping members to a second edge-gripping position and then in the opposite direction between said further clamping members and between and beyond the blades of the second guillotine and then in said forward direction between the blades of the second guillotine and then again in said opposite direction between and beyond the blades of the second guillotine, second adjustable means for limiting to an adjustable distance the second movement of said second gripping means in said opposite direction, and second control means for causing: a. said second gripping means in said second edge-gripping position to grip that edge of the lifted piece of sheet material that is nearest the second guillotine, b. said further clamping members to clamp the lifted piece of sheet material and said second gripping means to release it before the end of the first movement of said second gripping means in said opposite direction, c. operation of the second guillotine after that clamping and releasing whereby the lifted piece of sheet material is given a straight cut edge perpendicular to the straight cut edGes produced by the guillotine of the first apparatus, d. said second gripping means to grip the newly cut edge of the lifted piece of sheet material and said further clamping members to release that piece after operation of the second guillotine and the second movement of said second gripping means in said forward direction, e. said further clamping members to clamp the lifted piece of sheet material after further movement of said second gripping means in said opposite direction and f. the second guillotine then to operate again whereby the lifted piece of sheet material is given a second straight cut edge parallel to the first straight cut edge produced by the second guillotine.

4. A machine according to claim 3 in which the means recited in claim 3 includes a light-operated device adjacent the guillotine of the first apparatus for issuing a signal when the piece of sheet material, after said gripping means has been moved in said reverse direction for the second time, does not reach this guillotine and means responsive to said signal for preventing said piece from reaching the second apparatus.

5. A sheet material cutting machine comprising a first apparatus for cutting sheet material comprising a guillotine having two blades, means on one side of the guillotine for supporting a web of sheet material and for feeding one end of it towards the guillotine, two co-operating clamping members adjacent the guillotine on the side thereof from which said end approaches the guillotine, gripping means for gripping an edge region of the web at said end of the web, displacing means for moving said gripping means in one direction between the blades to an edge-gripping position and subsequently in the reverse direction between and beyond the blades, adjustable means for limiting to an adjustable distance said movement of the gripping means in said reverse direction and control means for causing: a. said gripping means in said edge-gripping position to grip said edge region of the web, b. said clamping members to clamp the web after said movement of said gripping means in the reverse direction has been halted by said adjustable means, c. the guillotine then to operate whereby there is separated from the web a piece of sheet material having a straight trailing edge, and d. the separated piece of sheet material to be free of said gripping means and said clamping members after said operation of the guillotine, said machine further comprising a second apparatus for producing on the separated piece of sheet material two more straight and parallel cut edges perpendicular to the said trailing edge, said second apparatus comprising a clamping device for clamping during said operation of the guillotine the part of the sheet material which becomes said separated piece of sheet material as a result of said operation of the guillotine, a second guillotine having two blades perpendicular to the blades of the first apparatus, two further co-operating clamping members adjacent the second guillotine between the second guillotine and said clamping device, second gripping means for gripping an edge region of the separated piece of sheet material, second displacing means for moving said second gripping means in a forward direction perpendicular to said one direction between the blades of the second guillotine and between said further clamping members to a second edge-gripping position and then in the opposite direction between said further clamping members and between and beyond the blades of the second guillotine and then in said forward direction between the blades of the second guillotine and then again in said opposite direction between and beyond the blades of the second guillotine, second adjustable means for limiting to an adjustable distance the second movement of said second gripping means in said opposite direction, and second control means for causing: e. said second gripping means in said second edge-gripping position to grip that edge region of the separated piece of sheet material that is nearest the second guillotine, f. said further clamping members to clamp the separated piece of sheet material and said second gripping means to release it when the second gripping means has moved the first time in said opposite direction g. operation of the second guillotine after that clamping whereby the separated piece of sheet material is given a straight cut edge perpendicular to said trailing edge, h. said second gripping means to grip the newly cut edge region of the separated piece of sheet material and said further clamping members to release that piece after operation of the second guillotine and the second movement of said second gripping means in said forward direction, i. said further clamping members to clamp the separated piece of sheet material after the second movement of said second gripping means in said opposite direction and j. the second guillotine then to operate again whereby the separated piece of sheet material is given a second straight cut edge parallel to the first straight cut edge produced by the second guillotine.

6. A machine according to claim 5 in which said first apparatus includes stop means for limiting movement of the gripping means in said reverse direction and said control means causes, before operation (a), said gripping means in said edge-gripping position to grip an edge region of the web at said end of the web, said clamping members to clamp the web after movement of said gripping means in the reverse direction is stopped by said stop means when said gripping means has moved an amount smaller than the distance it moves between operation (a) and (b), and then operation of the guillotine to remove from the web a portion that is narrower than the piece which is subsequently separated from the web in operation (c).

7. Apparatus for cutting sheet material comprising a guillotine having two blades, means near the guillotine for separating a piece of sheet material from a stack of such pieces, two co-operating clamping members adjacent the guillotine in the zone between the guillotine and the separating means, gripping means for gripping an edge region of the separated piece of sheet material, displacing means for moving said gripping means in one direction between the blades and between said clamping members to an edge-gripping position and then in the reverse direction between said clamping members and between and beyond the blades and then in said one direction between the blades and then again in said reverse direction between and beyond the blades, adjustable means for limiting to an adjustable distance the second movement of said gripping means in said reverse direction, and control means for causing: a. said gripping means in said edge-gripping position to grip that edge region of the separated piece of sheet material that is nearest the guillotine, b. said clamping members to clamp the separated piece of sheet material when said gripping means has moved the first time in said reverse direction c. operation of the guillotine after that clamping whereby the separated piece of sheet material is given a straight cut edge, d. said gripping means to grip the newly cut edge region of the separated piece of sheet material and said clamping members to release that piece after operation of the guillotine and the second movement of said gripping means in said one direction. e. said clamping members to clamp the separated piece of sheet material after the second movement of said gripping means in said reverse direction and f. the guillotine then to operate again whereby the separated piece of sheet material is given a second straight cut edge parallel to the first.

8. A sheet material cutting machine comprising a first apparatus according to claim 7 and a second apparatus for producing on the separated piece of sheet material two more straight and parallel cut edges perpendicular to the two produced by said first apparatus, said control means of said first apparatus serving to cause the separated piece of sheet material to be free of said gripping means and said clamping members after the second operation of the guillotine and said second apparatus comprising a clamping device for clamping the separated piece of sheet material whilst the guillotine is operating the second time, a second guillotine having two blades perpendicular to the blades of the first apparatus, two further co-operating clamping members adjacent the second guillotine between the second guillotine and said clamping device, second gripping means for gripping an edge region of the separated piece of sheet material, second displacing means for moving said second gripping means in a forward direction perpendicular to said one direction between the blades of the second guillotine and between said further clamping members to a second edge-gripping position and then in the opposite direction between said further clamping members and between and beyond the blades of the second guillotine and then in said forward direction between the blades of the second guillotine and then again in said opposite direction between and beyond the blades of the second guillotine, second adjustable means for limiting to an adjustable distance the second movement of said second gripping means in said opposite direction, and second control means for causing: a. said second gripping means in said second edge-gripping position to grip that edge region of the separated piece of sheet material that is nearest the second guillotine, b. said further clamping members to clamp the separated piece of sheet material and said second gripping means to release it when said second gripping means has moved the first time in said opposite direction c. operation of the second guillotine after that clamping whereby the separated piece of sheet material is given a straight cut edge perpendicular to the straight cut edges produced by the guillotine of the first apparatus, d. said second gripping means to grip the newly cut edge region of the separated piece of sheet material and said further clamping members to release that piece after operation of the second guillotine and the second movement of said second gripping means in said forward direction, e. said further clamping members to clamp the separated piece of sheet material after the second movement of said second gripping means in said opposite direction and f. the second guillotine then to operate again whereby the separated piece of sheet material is given a second straight cut edge parallel to the first straight cut edge produced by the second guillotine.

10. A machine according to claim 7 in which between the movement (b) and the following movement (c) the gripping means moves in said reverse direction after releasing the piece of sheet material.

11. Apparatus for cutting blanks from a sheet of material including first and second guillotines set at an angle to one another and means for operating them and conveying material to them so that the first guillotine cuts a series of pieces from the sheet and these pieces proceed in turn to the second guillotine which cuts a series of blanks from each of them, said means comprising two co-operating first clamping members adjacent the first guillotine, first gripping means for gripping an edge region of the sheet material, two co-operating second clamping members adjacent the second guillotine, second gripping means for gripping an edge region of the sheet material and control means foR causing: a. the first gripping means to move in one direction to an edge-gripping position and there to grip an edge region of the sheet of material, b. the first gripping means to move in the reverse direction with said edge region, c. the first clamping members to clamp the sheet and the first guillotine then to operate to cut a first piece from it, d. the second gripping means to move in a forward direction and then to grip an edge region of said first piece, e. the second gripping means to move in the opposite direction to pull said first piece between the blades of the second guillotine and the second clamping members then to clamp this piece and the second guillotine then to cut it, f. the second gripping means to move again in said forward direction and then to grip the newly cut edge region of said first piece and the second clamping members to release this piece and then the second gripping means to move again in said opposite direction to pull said first piece between the blades of the second guillotine and then the second clamping members to clamp this piece and the second guillotine to cut it, g. the movement (f) to be repeated to produce a plurality of similar blanks from the first piece, and h. subsequent pieces to be cut from said sheet by the first guillotine and themselves cut up by the second guillotine in the same way, the apparatus further comprising means for adjusting the extent of the movement (b) of the first gripping means in said reverse direction and means for adjusting the extent of the movement in (f) of the second gripping means in said opposite direction whereby the dimensions of the blanks produced can be adjusted.

17. Apparatus for cutting sheet material comprising a guillotine having two blades, means near the guillotine for supporting sheet material, two cooperating clamping members adjacent the guillotine in the zone between the guillotine and the supporting means, gripping means for gripping an edge region of the sheet material, displacing means for moving said gripping means in one direction between the blades to an edge-gripping position and subsequently in the reverse direction between and beyond the blades to a first stopping position and then in said one direction between the blades and then again in said reverse direction between and beyond the blades to a second stopping position, adjustable means for limiting to an adjustable distance the second movement of the gripping means in the reverse direction and control means for causing a. said gripping means in said edge gripping position to grip said edge region of the sheet material b. said clamping members to clamp the sheet after said first movement of said gripping means in the reverse direction to the first stopping position c. the guillotine then to operate to give a trimming cut on the leading edge of sheet material d. said gripping means to grip said edge region of the sheet in said edge gripping position after movement of said gripping means in said one direction e. said clamping members to clamp the sheet after said second movement of said gripping means in the reverse direction to the second stopping position f. the guillotine then to operate again whereby there is separated from the sheet a blank.