Machine for cutting cards from continuous strips employed in multi-copying
United States Patent 3924499
The invention relates to a method of cutting cards from a continuous strip employed in multi-copying, in which the cutting or separation operation is performed by punching. The punching operation is so effected as to first of all remove the active portion of a card while leaving as waste lateral punched strips and intermediate connecting strips between the successive cards and the separated cards and the waste are collected separately and in the order of introduction. The machine comprises principally: a support surface (2) for receiving a pack (3) of cards to be subjected to the cutting operation; an intermittently operable drive mechanism for advancing the cards; a punching mechanism (5) to which the cards to be cut out are brought by the intermittent drive mechanism; a magazine (11) for collecting in the order of presentation the cards which have been cut out and a table (12) for reception of the waste. (Figure 1)
US Patent References:
/1009179.html
Richards - November 1911 - 1009179
/1058101.html
Richards - April 1913 - 1058101
Apparatus for automatically making and assembling filing cards
Anderson et al. - February 1940 - 2188994
Method and apparatus for cutting webs
Korsgaard - January 1943 - 2307889
Grid trimmer
Winkel - May 1945 - 2375717
/1009179.html
Richards - November 1911 - 1009179
/1058101.html
Richards - April 1913 - 1058101
Apparatus for automatically making and assembling filing cards
Anderson et al. - February 1940 - 2188994
Method and apparatus for cutting webs
Korsgaard - January 1943 - 2307889
Grid trimmer
Winkel - May 1945 - 2375717
Inventors:
Dechambre, Jean Theophile Fortunat (Heusy, BE)
Lousberg, Pierre Jean Simon (Stembert, BE)
Pirard, Joseph Jean Julien (Petit-Rechain, BE)
Lousberg, Pierre Jean Simon (Stembert, BE)
Pirard, Joseph Jean Julien (Petit-Rechain, BE)
Application Number:
05/479589
Publication Date:
12/09/1975
Filing Date:
06/14/1974
View Patent Images:
Export Citation:
Primary Class:
Other Classes:
83/628, 83/275, 83/140, 83/423, 83/278, 83/92, 83/633
International Classes:
B26F1/40; B26F3/00; B41J11/70; B65H20/22; B26F1/38; B65H20/20; B26D5/22
Field of Search:
83/50,92,96,103,140,275,278,423,628,633
US Patent References:
Primary Examiner:
Yost, Frank T.
Attorney, Agent or Firm:
Waters, Schwartz & Nissen
Claims:
What we claim is
1. A machine for cutting cards from a continuous strip employed in multi-copying by a punching operation comprising a machine frame, a punching mechanism supported by said frame, means for serially advancing a pack of cards to a location for punching in the order of presentation, and means for collecting cards which have been cut out by said punching mechanism, said punching mechanism including a plurality of rods which are vertically slidable in said machine frame, a punch, a frame provided around said punch, a transverse bar coupling said punch to said rods, springs being interposed between said frame and transverse bar to provide an even pressure around the outer periphery of a punched card when the latter has been brought into the punching position.
2. A machine according to claim 1, including a support surface for receiving said pack of cards to be subjected to the cutting operation, said card advancing means comprising an intermittently operable drive mechamism, a magazine for collecting cards which have been cut out in the order of presentation, and a table for reception of waste.
3. A machine according to claim 2, wherein the intermittently operable drive mechanism comprises chains provided with sprockets.
4. A machine according to claim 3, in which the chains are driven under the control of a main shaft which carries a pinion provided with teeth around only part of its periphery and engaging a toothed wheel fast with the drive shaft of the wheels about which the chains are driven.
5. A machine according to claim 4, in which on the input shaft of the drive chains in fixed a cam device, having a notch engageable by a pawl for immobilising the drive chains during the period of stoppage of the latter.
6. A machine according to claim 4 including means for rocking the long rear side portion of the punch bolster, the said means comprising a cam which is fixed on the main shaft approximately in its centre and which acts through a roller carried by a bent lever fast with the rear side portion for causing pivoting of the rear side portion, adjustment of the cam ensuring rocking of the precise moment of passage of a small tongue remaining after cutting.
7. A machine according to claim 1 in which the punching mechanism is contructed so that cutting takes place in two stages, in the first stage a card is brought under said cutting punch and stopped under the latter due to the stoppage of the drive mechanism and in the second stage the periphery of the card is held by said frame during the stroke of the punch which performs the cutting.
8. A machine according to claim 1, in which for the control of the cutting operation, two cams are keyed on the main shaft for action on horizontally arranged levers at the ends of which are pivoted arms which are pivotable about fixed axes, the vertically slidable rods being mounted on the levers.
9. A machine according to claim 8, in which in a first stage of the cutting a punched card is brought under the cutting punch and immobilised due to the stoppage of said card advancing means, and in a second stage lowering of the punch is effected under the control of the cams, the levers and the rods, during the downward motion the periphery of the card being held by the frame.
10. A machine according to claim 9 in which the rods carry means which permit temporary raising of the frame upon advancing of a card before it is stopped under the punch.
1. A machine for cutting cards from a continuous strip employed in multi-copying by a punching operation comprising a machine frame, a punching mechanism supported by said frame, means for serially advancing a pack of cards to a location for punching in the order of presentation, and means for collecting cards which have been cut out by said punching mechanism, said punching mechanism including a plurality of rods which are vertically slidable in said machine frame, a punch, a frame provided around said punch, a transverse bar coupling said punch to said rods, springs being interposed between said frame and transverse bar to provide an even pressure around the outer periphery of a punched card when the latter has been brought into the punching position.
2. A machine according to claim 1, including a support surface for receiving said pack of cards to be subjected to the cutting operation, said card advancing means comprising an intermittently operable drive mechamism, a magazine for collecting cards which have been cut out in the order of presentation, and a table for reception of waste.
3. A machine according to claim 2, wherein the intermittently operable drive mechanism comprises chains provided with sprockets.
4. A machine according to claim 3, in which the chains are driven under the control of a main shaft which carries a pinion provided with teeth around only part of its periphery and engaging a toothed wheel fast with the drive shaft of the wheels about which the chains are driven.
5. A machine according to claim 4, in which on the input shaft of the drive chains in fixed a cam device, having a notch engageable by a pawl for immobilising the drive chains during the period of stoppage of the latter.
6. A machine according to claim 4 including means for rocking the long rear side portion of the punch bolster, the said means comprising a cam which is fixed on the main shaft approximately in its centre and which acts through a roller carried by a bent lever fast with the rear side portion for causing pivoting of the rear side portion, adjustment of the cam ensuring rocking of the precise moment of passage of a small tongue remaining after cutting.
7. A machine according to claim 1 in which the punching mechanism is contructed so that cutting takes place in two stages, in the first stage a card is brought under said cutting punch and stopped under the latter due to the stoppage of the drive mechanism and in the second stage the periphery of the card is held by said frame during the stroke of the punch which performs the cutting.
8. A machine according to claim 1, in which for the control of the cutting operation, two cams are keyed on the main shaft for action on horizontally arranged levers at the ends of which are pivoted arms which are pivotable about fixed axes, the vertically slidable rods being mounted on the levers.
9. A machine according to claim 8, in which in a first stage of the cutting a punched card is brought under the cutting punch and immobilised due to the stoppage of said card advancing means, and in a second stage lowering of the punch is effected under the control of the cams, the levers and the rods, during the downward motion the periphery of the card being held by the frame.
10. A machine according to claim 9 in which the rods carry means which permit temporary raising of the frame upon advancing of a card before it is stopped under the punch.
Description:
The present invention relates to a process and a machine for cutting cards from continuous strips employed in multi-copying.
These cards are printed in advance by passage through a computer and are then cut out for use as index-cards or for other purposes.
In machines known at the present time, the cutting apparatus are based on the tearing principle and do not ensure recovery of the cards in the order in which they are introduced. This is due to the fact that the cards are thrown horizontally and that there is thus a risk that they will become mixed in an order not corresponding to the order in which they were introduced. Moreover, because of this tearing action, the small separation tongues which exist between the cards are torn and the edges of the cards are not even.
An aim of the present invention is to permit, by means of a simple, compact machine within the reach of all businesses, recovery of the cards in impeccable condition permitting use in computers or ancillary machines and to perform the operation in such a manner that recovery can take place in the order of initial presentation.
According to one aspect of the present invention there is provided a method of cutting out cards from a continuous strip employed in multi-copying, in which the cutting or separation operation is performed by punching.
The punching operation may be so performed as to first of all remove the active portion of each card, leaving lateral punched strips and intermediate connection strips between successive cards as waste, the separated cards and the waste being collected separately and in the order of introduction.
According to another aspect of the present invention there is provided a machine for carrying out the above method comprising:
A. A SUPPORT SURFACE FOR RECEIVING A PACK OF CARDS TO BE SUBJECTED TO THE CUTTING OPERATION;
B. AN INTERMITTENTLY OPERABLE DRIVE MECHANISM FOR ADVANCING THE CARDS;
C. A PUNCHING MECHANISM TO WHICH A CARD TO BE CUT OUT IS BROUGHT BY THE INTERMITTENT DRIVE MECHANISM;
D. A MAGAZINE FOR COLLECTING CARDS WHICH HAVE BEEN CUT OUT IN THE ORDER OF PRESENTATION; AND
E. A TABLE FOR RECEPTION OF THE WASTE.
In a preferred embodiment of the invention, the punching mechanism is so constructed that cutting takes place in two stages, in the first stage the card is brought under a cutting punch and stopped under the latter due to the stoppage of the card drive mechanism and in a second stage the periphery of the card is held by a frame during the stroke of the punch which effects cutting proper.
The punching mechanism generally comprises a punch coupled by a transverse bar to the ends of rods which are vertically slidable in the machine frame-work and, around the punch, there is provided a frame between which and the transverse bar springs are interposed to provide an even pressure around the outer periphery of a card when the latter has been brought into the punching position.
The machine may include means for rocking the long rear side portions of the punch bolster, this rocking being controlled for example by a cam which is fixed to the main shaft approximately in its centre and which acts through a roller carried by a bent lever fast with the rear side portion for pivoting this rear side portion, adjustment of this cam causing rocking at the precise moment of the passage of a small tongue remaining after cutting.
Other features of the invention will become apparent from the following description of an embodiment of a machine in accordance with the invention, given by way of example only, with reference to the accompanying drawings, in which:
FIG. 1 is a perspective view of the machine;
FIG. 1A illustrates the basis of the method on which the machine operates;
FIG. 2 is a horizontal section through the machine of FIG. 1 showing various control apparatus of the machine;
FIGS. 3 and 4 are views partially in vertical section in particular showing the control of the punch and the punching apparatus;
FIG. 5 is a detailed view of the apparatus for rocking one side of the punch bolster; and
FIGS. 6 and 7 show the control apparatus of the chains for driving the punched cards.
The machine comprises a frame-work 1 (FIG. 1) including, towards the front, a table 2 or entablature on which is arranged a pack 3 of cards interconnected so as to form a strip 4; this strip 4 unfolds and rises towards a cutting mechanism 5 (FIG. 1) situated in the upper portion of the frame-work 1 between two side plates 6.
The strip 4 comprises (FIG. 1A) a series of cards 7 joined by a connection permitting easy release to lateral strips 8 provided with punch-holes 9 and to strips 10 extending between two successive cards and fixed to the lateral strips 8.
The cards 7 are separated by the action of the cutting mechanism 5 and fall into a shaft or magazine 11 (FIG. 1) from which they are collected by hand, while the waste which interconnected the cards (punched strips 8 and 10) is directed to an output table 12.
The mechanism for driving the strip of cards, which operates intermittently, comprises two chains 13 (FIG. 7) provided with sprockets 14 for entering punchholes 9 in the strips 8, the chains running round chainwheels 15, 16 keyed on shafts 17 and 18 rotating in bearings 19 (FIG. 2) provided in side plates 6 of the frame-work?
The machine is generally driven from a main shaft 20 parallel to the shafts 17, 18 and which is driven by a geared-down motor 31 (FIG. 3) housed inside the frame-work and driving the main shaft 20 by means of a trapezoidal belt 21 passing over a pulley 22 fixed on the main shaft 20.
On the shaft 20 is fixed a pinion 23 which meshes with a pinion 24 keyed on the shaft 18. The pinion 23 is provided with teeth on only part of its periphery (FIG. 6) so as to provide intermittent motion of the drive chains by engagement of the pinion 23 with the pinion 24.
The geared-down motor 31 is started by a switch 25 (FIG. 1) having an indicator light positioned on the front part of the machine.
Outside the frame-work an operating handwheel 26 is fixed on the end of shaft 20 enabling the machine to be worked manually. This manual rotation is necessary on starting to appropriately engage the strip 4 of cards with the chains with respect to a reference mark (not shown) provided on the sprocket drive chain 13. To allow this manual feeding, the drive pulley 22 drives the main shaft 20 through a free-wheel permitting manual rotation of the shaft without rotation of the geared-down motor.
On the input shaft 17 (FIG. 6) there is keyed a cam 30 having a notch and a pawl 31, pivotable about an axis 32 and subjected to the action of a spring 33, is engageable in the notch to immobilise the drive chains 13 during the stoppage periods of the latter; this stoppage corresponds to the cutting phase.
To control the cutting (FIGS. 3 and 4) two cams 34 are keyed on the main shaft 20 and act on levers 35 extending parallel to the side-plates 6 at the lower part of the latter and at the ends of which are pivoted arms 36 which are pivotable about fixed axis 37. Return springs 55 ensure permanent contact between the cams and the levers. On levers 35, approximately at their centres, are mounted rods 38 guided in bushes 39 (FIG. 4).
A punch 40 is coupled to the ends of rods 38 by means of a transverse bar 41. The coupling is effected by means of knurled nuts 42 and permits easy disassembly.
Around the punch 40 there is provided a frame 43 called a "stripper" ; springs 44 arranged on either side of the punch 40 between the transverse bar 41 and the frame 43 provide an even pressure around the outer periphery of the punched card when the latter has been brought into the cutting position.
The operation of cutting the cards is effected in two stages:
In the first stage, the punched card is brought under the cutting punch 40 and immobilised due to the stoppage of the chains 13 determined by the position of the toothed wheel 23.
In the second stage the downward stroke of the punch 40 takes place, controlled by the cams 34, the levers 35 and the rods 38; during this descent the periphery of the card is held by the frame 43 while the card 7 is cut out.
Rings 45 fast with each of the rods 38 permit temporary lifting of the frame 43 on advance of the card before it is stopped under the punch.
An important feature is that means is provided for causing rocking of the long rear side portion 49 of the punch bolster.
This rocking is controlled by a cam 46 (FIG. 5) which is fixed on the main shaft 20 approximately at its centre and which acts through a roller 47 carried by a bent lever 48 fast with the side portion 49 so as to cause the pivoting of the latter about an axis 50 (FIG. 5).
The adjustment of the cam permits the rocking at the precise moment of passage of the small tongue remaining after cutting.
After cutting the card is received on a base 51 mounted on compensator springs 52 (FIG. 3).
An electric contact 53 is so arranged that the base 51 cuts off the supply current to the motor when the magazine 11 is full.
The general operation of the machine may be summarised as follows:
The strip of cards arranged on the table 2 is driven intermittently by the chains 13 to be presented during the stoppage periods to the action of the cutting apparatus 40 whose operation has been described above and which effects the separation of a card 7 very precisely and without damaging it.
The cards thus separated are stored in the magazine 11 (FIGS. 1 and 3) permitting their easy recovery in the order of initial presentation.
The waste which joined the cards continues its advance motion, being driven by the chains 13.
To avoid catching of the small tongue which separates two successive cards, the long rear side of the bolster frame dips for a moment as it rocks.
A considerable advantage is that, instead of being effected by tearing, cutting is performed by punching. Additionally the punching apparatus is so designed that the recovery of the cards takes place by superimposition in the order of initial presentation.
The continuous manner of separation of the cards is perfectly suited to all businesses which desire to print a maximum of information from a computer onto index cards for advantageous use in any management system.
Operating simply and silently, this machine can separate 15,000 cards, which remain filed in the order of printing, per hour without deforming them, thus offering a guarantee upon eventual retrieval for reading/punching by the computer or any ancillary machine.
Fitted with safety devices, the machine can work without any surveillance. It may be compact --0,40 m ×0,80 m -- and may require no maintenance .
These cards are printed in advance by passage through a computer and are then cut out for use as index-cards or for other purposes.
In machines known at the present time, the cutting apparatus are based on the tearing principle and do not ensure recovery of the cards in the order in which they are introduced. This is due to the fact that the cards are thrown horizontally and that there is thus a risk that they will become mixed in an order not corresponding to the order in which they were introduced. Moreover, because of this tearing action, the small separation tongues which exist between the cards are torn and the edges of the cards are not even.
An aim of the present invention is to permit, by means of a simple, compact machine within the reach of all businesses, recovery of the cards in impeccable condition permitting use in computers or ancillary machines and to perform the operation in such a manner that recovery can take place in the order of initial presentation.
According to one aspect of the present invention there is provided a method of cutting out cards from a continuous strip employed in multi-copying, in which the cutting or separation operation is performed by punching.
The punching operation may be so performed as to first of all remove the active portion of each card, leaving lateral punched strips and intermediate connection strips between successive cards as waste, the separated cards and the waste being collected separately and in the order of introduction.
According to another aspect of the present invention there is provided a machine for carrying out the above method comprising:
A. A SUPPORT SURFACE FOR RECEIVING A PACK OF CARDS TO BE SUBJECTED TO THE CUTTING OPERATION;
B. AN INTERMITTENTLY OPERABLE DRIVE MECHANISM FOR ADVANCING THE CARDS;
C. A PUNCHING MECHANISM TO WHICH A CARD TO BE CUT OUT IS BROUGHT BY THE INTERMITTENT DRIVE MECHANISM;
D. A MAGAZINE FOR COLLECTING CARDS WHICH HAVE BEEN CUT OUT IN THE ORDER OF PRESENTATION; AND
E. A TABLE FOR RECEPTION OF THE WASTE.
In a preferred embodiment of the invention, the punching mechanism is so constructed that cutting takes place in two stages, in the first stage the card is brought under a cutting punch and stopped under the latter due to the stoppage of the card drive mechanism and in a second stage the periphery of the card is held by a frame during the stroke of the punch which effects cutting proper.
The punching mechanism generally comprises a punch coupled by a transverse bar to the ends of rods which are vertically slidable in the machine frame-work and, around the punch, there is provided a frame between which and the transverse bar springs are interposed to provide an even pressure around the outer periphery of a card when the latter has been brought into the punching position.
The machine may include means for rocking the long rear side portions of the punch bolster, this rocking being controlled for example by a cam which is fixed to the main shaft approximately in its centre and which acts through a roller carried by a bent lever fast with the rear side portion for pivoting this rear side portion, adjustment of this cam causing rocking at the precise moment of the passage of a small tongue remaining after cutting.
Other features of the invention will become apparent from the following description of an embodiment of a machine in accordance with the invention, given by way of example only, with reference to the accompanying drawings, in which:
FIG. 1 is a perspective view of the machine;
FIG. 1A illustrates the basis of the method on which the machine operates;
FIG. 2 is a horizontal section through the machine of FIG. 1 showing various control apparatus of the machine;
FIGS. 3 and 4 are views partially in vertical section in particular showing the control of the punch and the punching apparatus;
FIG. 5 is a detailed view of the apparatus for rocking one side of the punch bolster; and
FIGS. 6 and 7 show the control apparatus of the chains for driving the punched cards.
The machine comprises a frame-work 1 (FIG. 1) including, towards the front, a table 2 or entablature on which is arranged a pack 3 of cards interconnected so as to form a strip 4; this strip 4 unfolds and rises towards a cutting mechanism 5 (FIG. 1) situated in the upper portion of the frame-work 1 between two side plates 6.
The strip 4 comprises (FIG. 1A) a series of cards 7 joined by a connection permitting easy release to lateral strips 8 provided with punch-holes 9 and to strips 10 extending between two successive cards and fixed to the lateral strips 8.
The cards 7 are separated by the action of the cutting mechanism 5 and fall into a shaft or magazine 11 (FIG. 1) from which they are collected by hand, while the waste which interconnected the cards (punched strips 8 and 10) is directed to an output table 12.
The mechanism for driving the strip of cards, which operates intermittently, comprises two chains 13 (FIG. 7) provided with sprockets 14 for entering punchholes 9 in the strips 8, the chains running round chainwheels 15, 16 keyed on shafts 17 and 18 rotating in bearings 19 (FIG. 2) provided in side plates 6 of the frame-work?
The machine is generally driven from a main shaft 20 parallel to the shafts 17, 18 and which is driven by a geared-down motor 31 (FIG. 3) housed inside the frame-work and driving the main shaft 20 by means of a trapezoidal belt 21 passing over a pulley 22 fixed on the main shaft 20.
On the shaft 20 is fixed a pinion 23 which meshes with a pinion 24 keyed on the shaft 18. The pinion 23 is provided with teeth on only part of its periphery (FIG. 6) so as to provide intermittent motion of the drive chains by engagement of the pinion 23 with the pinion 24.
The geared-down motor 31 is started by a switch 25 (FIG. 1) having an indicator light positioned on the front part of the machine.
Outside the frame-work an operating handwheel 26 is fixed on the end of shaft 20 enabling the machine to be worked manually. This manual rotation is necessary on starting to appropriately engage the strip 4 of cards with the chains with respect to a reference mark (not shown) provided on the sprocket drive chain 13. To allow this manual feeding, the drive pulley 22 drives the main shaft 20 through a free-wheel permitting manual rotation of the shaft without rotation of the geared-down motor.
On the input shaft 17 (FIG. 6) there is keyed a cam 30 having a notch and a pawl 31, pivotable about an axis 32 and subjected to the action of a spring 33, is engageable in the notch to immobilise the drive chains 13 during the stoppage periods of the latter; this stoppage corresponds to the cutting phase.
To control the cutting (FIGS. 3 and 4) two cams 34 are keyed on the main shaft 20 and act on levers 35 extending parallel to the side-plates 6 at the lower part of the latter and at the ends of which are pivoted arms 36 which are pivotable about fixed axis 37. Return springs 55 ensure permanent contact between the cams and the levers. On levers 35, approximately at their centres, are mounted rods 38 guided in bushes 39 (FIG. 4).
A punch 40 is coupled to the ends of rods 38 by means of a transverse bar 41. The coupling is effected by means of knurled nuts 42 and permits easy disassembly.
Around the punch 40 there is provided a frame 43 called a "stripper" ; springs 44 arranged on either side of the punch 40 between the transverse bar 41 and the frame 43 provide an even pressure around the outer periphery of the punched card when the latter has been brought into the cutting position.
The operation of cutting the cards is effected in two stages:
In the first stage, the punched card is brought under the cutting punch 40 and immobilised due to the stoppage of the chains 13 determined by the position of the toothed wheel 23.
In the second stage the downward stroke of the punch 40 takes place, controlled by the cams 34, the levers 35 and the rods 38; during this descent the periphery of the card is held by the frame 43 while the card 7 is cut out.
Rings 45 fast with each of the rods 38 permit temporary lifting of the frame 43 on advance of the card before it is stopped under the punch.
An important feature is that means is provided for causing rocking of the long rear side portion 49 of the punch bolster.
This rocking is controlled by a cam 46 (FIG. 5) which is fixed on the main shaft 20 approximately at its centre and which acts through a roller 47 carried by a bent lever 48 fast with the side portion 49 so as to cause the pivoting of the latter about an axis 50 (FIG. 5).
The adjustment of the cam permits the rocking at the precise moment of passage of the small tongue remaining after cutting.
After cutting the card is received on a base 51 mounted on compensator springs 52 (FIG. 3).
An electric contact 53 is so arranged that the base 51 cuts off the supply current to the motor when the magazine 11 is full.
The general operation of the machine may be summarised as follows:
The strip of cards arranged on the table 2 is driven intermittently by the chains 13 to be presented during the stoppage periods to the action of the cutting apparatus 40 whose operation has been described above and which effects the separation of a card 7 very precisely and without damaging it.
The cards thus separated are stored in the magazine 11 (FIGS. 1 and 3) permitting their easy recovery in the order of initial presentation.
The waste which joined the cards continues its advance motion, being driven by the chains 13.
To avoid catching of the small tongue which separates two successive cards, the long rear side of the bolster frame dips for a moment as it rocks.
A considerable advantage is that, instead of being effected by tearing, cutting is performed by punching. Additionally the punching apparatus is so designed that the recovery of the cards takes place by superimposition in the order of initial presentation.
The continuous manner of separation of the cards is perfectly suited to all businesses which desire to print a maximum of information from a computer onto index cards for advantageous use in any management system.
Operating simply and silently, this machine can separate 15,000 cards, which remain filed in the order of printing, per hour without deforming them, thus offering a guarantee upon eventual retrieval for reading/punching by the computer or any ancillary machine.
Fitted with safety devices, the machine can work without any surveillance. It may be compact --0,40 m ×0,80 m -- and may require no maintenance .