Document BRZdYg7XX03zObq8wX8Gm8q6m

PATENT SPECIFICATION ft DRAWINGS ATTACKED Sj (21) Applkatioa No. 6911/70 (22) Fifed 12 Feb. 1970 GO (23) Complete Specification filed 14 Jan. 1971 (44) Complete Spedfiattian published 2 May 1973 PH (51) International Classification B65B 69/00 CO (52) Index at acceptance fH BSC 10B1B 10B1D1 10B1D3 10P1C 10P1D 7A (72) Inventor HALDANE BERTRAM PRESTON <"> 1315853 (54) MACHINE FOR OPENING AND EMPTYING BAGS CONTAINING FIBROUS MATERIALS (71) We, TAC CONSTRUCTION MATERIALS LIMITED (formerly Turner* Asbestos Cement Company Limited) a British Company of Asbestos House, Fountain Street, 5 Manchester, Lancashire, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following state10 ment: -- Asbestos fibres art nearly always trans ported packed in bap. This is necessary to enable the fibres to be held somewhat com pressed as otherwise their bulk for a given 15 weight is excessive. Similar considerations apply to other fibrous materials of compara tively low density such as raw wool or kapok. It has been usual in the past for these bags to be opened and emptied manually and for 20 this purpose the bags are slit across one end and are then shaken vigorously with the opened end lowermost. However this manual opening is time consuming and therefore expensive and, particularly in the case of 25 asbestos fibres, the dust which is produced may constitute a health hazard to the workers opening and emptying the bags. It is very desirable therefore to be able to open and empty bags mechanically. Existing 30 machines for carrying out this operation, how ever, act by cutting the bag approximately centrally around a part of its periphery white the two ends of the bag are held and the two ends of the bag are then twisted at an angle to 35 each other to form an open slit and the bag is then mechanically shapes. It has been found that these machines operate quite well with bags containing granular material or other material which will flow evenly from the slit 40 b the bag, but with asbestos fibres or other fibres of a fiocculent cohesive nature, the results arc not satisfactory. With asbestos in particular, the contents do not fall out of the slit, but remain so firm as to make effective 45 shaking impossible, and with other material it is found that a substantial amount of the material remains sticking to the inside of the bag and this is wasted. The aim of the present invention is to provide a machine which b capable of removmg fibrous material such as asbestos fibres or other fiocculent cohesive material from bags b an efficient manner so that to all btents and purposes all of the material b removed. To this end, according to thb bvention, such a machine comprises a support for sup porting a bag of the material b a lying posi tion b engagement with a cutter, a mechanism for moving the bag and the cutter relatively to each other to cut the bag along one end and along the adjacent sides, or along one end, ooe adjacent side and the other end, and a stripping device which pips the pan of the bag below the cut and strips it away from its contents and b so doing moves the bag and its contents towards the edge of a separating partition which b adjacent the stripping device so that the stripped bag passes on one side of the partition. In thb way by making a relatively long slit around two rides and one end, or two ends and one side of the bag and drawing the bag away from the contents rather than emptying the contents from the bag, it has been found that the separation between the bag and the contents can be extremely effective. Preferably the support for the bag b b the form of a platform on which the bag moves towards the stripping device and b slit during its movement. The trailing end of the bag remains unslit and the stripping device then draws the bottom part of the teg below the slit onwards m its direction of movement downwards closely past a substantially borirontal edge oi the separating partition which slopes downwards from thb edge. The teg b that drawn onwards by the strippbg device below the edge of the partition and the con tents of the bag b pushed by the remaining part of the teg at the unslit trailing end and she part of the teg above the rih oyer the 50 55 60 65 70 75 80 85 90 [Price 25p] CTD025925 ^1 SERWENT PUBLICATIONS LTDj 1,315,853 top of the partition before this part of the To enable the machine to a^vimmodate bag is itself dragged down by the stripping bags of different widths and slit tneir side- device below the partition. without the rotary knives penetrating loo The platform on which the bag is sup- deeply into the hag contents, the distance 5 ported may be horizontal and in this case it apart by which the knives are set after they may consist of a series of power driven rollers have slit the leading end of the bag is pre for conveying the bag to the stripping device, ferably automatically adjustable in dependence but preferably the platform is inclined down upon the width of the hag. For this purpose wards towards the stripping device and con- feelers are provided for sensing the width of 10 sisu of freely rotatable conveyor rollers over the bag and these feelers control the mech which the bag is moved by gravity. anism by which the knives arc swung apart The stripping device may consist of a from each other to limit the movement apart power-driven spiked roller, the spikes of in dependence upon the width of the hag which pierce the part of tl*c bag below the which has been sensed. 15 slit and draw it away from its contents as the The feelers arc preferably formed by clamp roller rotates. Rotation of the roller takes ing pads which move in laterally and grip place in a direction which assists the pacreg? .v- -:j-, rf lj1- g.........,|ic.nl whcn (he of the bag on its supporting platform past the bag moves on the support into contact with cutter and onwards to the edge of the separat- the first rotary knife. These clamping pads 20 ing partition which is arranged in a position therefore perform the double function of 85| spaced around the periphery of the spiked sensing the width of the bag and also hold roller from the platform which forms the ing the bag while the two rotary knives make support for the bag. their slits across its leading end. After this With a support in the form of a power the clamping pads move apart from each other 25 driven or gravity roller conveyor, the bag to allow the bag to move on its platform con- 901 moves relatively to the cutter as its sides arc sisting of power driven or gravity rollers slit, but preferably the cutter is also mounted onwards towards the stripping device while the so that it moves to make the initial slit knives slit the sides of the bag. across the leading end of the bag. For this To enable the clamping pads to set the 30 purpose the cutter may comprise a pair of positions of the rotary knives for slitting the 951 rotary knives each of which is mounted on sides of the bags, the clamping pads arc con the end of an arm which is pivoted about an nected to a stop which is set in a position upright axis to enable the knife to swing along dependent upon the position in which the a substantially horizontally disposed arc of damping pads move inwards to hold the bag. 35 movement which extends across the path of This stop operates a limit switch on the the bag from its platform or other support mechanism which swings the knives at. I slops towards the stripping device. the swinging movement when the knives arc Preferably the knives are swung by a at ? distance apart which is dependent upon mechanism which is arranged so that initially the position of the stop and thus also depen 40 one rotary knife is disposed directly in the dent on the width of the hag as determined J05 path of movement of the bag so that it forms by the distance between the clamping pads. a slit in the end of the bag as the bag moves An example of a machine constructed in rm towards it. The two knives arc then swung accordance with the invention is illustrated w;`h each other across the path of movement somewhat diagrammatically in the accompany 45 of the bag so that the first knife extends its ing drawings, in which:-- no slit to one side of the bag and the second Figure 1 is a plan; knife makes a slit from the other side of the Figure 2 is a section as seen in the direction bag extending towards and intersecting the of the arrows on the line II--II in Figure I; slit made by the first knife. To ensure that the Figure 3 is a section as seen in the direc 50 two slits made by the two rotary knives across tion of the arrows on the line III--III in 115 the end of the bag intersect each other, the Figure 2; and, planes of action of the rotary knives arc pre Figure 4 is a perspective view of a bag ferably slightly inclined out of the horizontal showing the slits cut in it by the machine. in opposite directions to each other. The machine has an outer metal casing 1 55 Preferably after the knives have been which in addition to forming an enclosure for 120 ! swung laterally to slit the end of the bag, most of the working pans of the machine, they are swung apart from each other until also forms a chassis supporting the various they arc separated by a distance somewhat parts of the mechanism. At the left-hand side less than the width of the bag between its of the casing 1 as seen in Figure 2, there is a 60 two sides. As the bag then passes from its hag suppon in the form of a hoist platform 2. 125 platform towards the stripping device and The hoist platform is movable upwards and then onwards to the separating partition, the downwards between the raised position shown two knives extend their slits from the leading in full lines in Figure 2 and a lowered posi end of the bag along its two sides and leave tion shown in chain-dotted lines at 2'. The 65 the trailing end unslit. platform 2 carries a scries of freely totatable 130 CTD025926 'WENT PUBLICATIONS LTD 1,315,853 conveyor rollers 3 which form its supporting of the machine turns, the cylinder of the face. The platform is carried by guide rollers pneumatic ram 26 moves towards the right * which run in guides which are fixed to the and in consequence the operating mem be: 28 sides of the casing 1 and one of which is of the microswitch also moves to the right and 5 indicated in chain-dotted lines at 5. The put- ends up in a position which is dependent upon 70 form 2 is raised and lowered by a cable 6 the width of the bag. which is wound up and unwound by a hoist 7 A bag cutter is formed by a pair of rotary which is fixed to a top plate 8 of the casing knives 29 and 30 which are carried on the 1 by a bracket 9. shafts of their own individual electric driving 10 When the platform 2 is in its lowered motors 31 and 32 respectively. The motors 75 position shown at 2', it is at the same level 31 and 32 are mounted on arms 33 and 34 as a roller table 10 which is mounted just respectively and these arms arc fixed to outside the casing 1. Above the table 10, the upright shafts 35 and 36 which are rotatably casing 1 has an inlet opening 11 and, in use, mounted in bearing brackets 37 and 38 fixed 15 a bag containing asbestos fibres or other to the top of the casing 1. 80 flocculent cohesive material is placed on the Levers 39 and 40 are fixed to the tops of table 10 and is then pushed manually onu the shafts o) auu ju iup,vioc!y Sim j the platform 2 when this is in its lowered at their ends cam follower rollers which engage position. After this the platform 2 is raised in cam grooves 41 and 42 in a rotary cam 20 by the cable 6 and as the guide rollers 4 pass drum 43. 85 around the bend in the guide 5 as shown in In use, the rotary cam drum 43 is turned by Figure 2, the platform 2 tilts into the position a driving motor which is not shown and as shown in full lines in Figure 2. the cam follower rollers on the ends of the A pair of damping pads 10' arc mounted levers 39 and 40 follow their groove*, the 25 on each of two side plates IT of the casing levers 39 and 40 are swung backwards and 90 1 and these damping pads arc movable forwards and the arms 33 and 34 move with towards and away from each other. To enable them so that the rotary knives 29 and 30 are the pad* 10' to be moved towards and away also swung to and fro. The microswitch which from each other, their outer ends are pivotally has the operating member 28 is connected in 30 connected to levers 12 and 13 which arc fixed a control circuit of the motor which routes 95 to shafts 14. The shafts 14 arc rotatable in the cam drum 43 and the lever 39 has a second bearings 15 which arc fixed to projecting arm 44 which, as the rotary knife 29 is swung parts 16 of the housing 1 and in further bear outwards comes into contact with the operat ings 17 carried by brackets 18. ing member 28 and opens the switch thus 35 The levers 13 terminate at the shafts 14, but stopping the motor which drives the <*m drum 100 the lesers 12 have second arms 19 and 20 43 and stopping the swing of the knives 29 which extend upwards above the shafts 14. and 30 at a distance apart which is dependent The upper end of the arm 19 is pivotally con upon the position in v.hich the operaring nected by a connecting rod 21 to the upper member 28 is set and this in turn is dependent 40 end of a two-armed lever 22 which is pivotally upon the positions of the clamping pads 10* 105 mounted on a bracket 23. The arm 20 is and the width of the bag which is clamped pivotally connected by a connecting rod 24 between the pads 10. to the bottom end of the lever 22 and the Aligned with the supporting surface formed connecting rod 24 extends past the end of the by the rollers 3 when the hoist platform 2 is 45 lever 22 and is pivotally connected to a in its raised position are further freely rout- HO piston rod 25 of a pneumatic ram 26. The able conveyor rollers 45 supported by the right-hand end, as seen in Figure 3, of the sides of the casing 1. On the side of the cylinder of the pneumatic ram .' * pivotally rollers 45 remote from the platform 2 is a attached to the arm 19 and the Iclt-hand end stripping device in the form of a rotary spiked 50 of the cylinder carries a bracket 27 which roller 46 which is driven by an electric motor 115 supports a microswiich with an operating which is not shown. On the side of the spiked member 28. roller 46 remote from the rollers 45 and the When the pneumatic ram 26 is extended, platform 2 is an inclined partition 47 which the levers 12 and 13 on the right-hand side has its upper edge 48 very dose to the rips 55 of the machine as shown in Figure 3 rock in of the spikes on the roller 46. The partition 120 a clockwise direction and the levers 12 and 47 leads downwards to a space 49 formed 13 on the left-hand side of the machine rock between one face of the casing 1 and a wall in a counterclockwise direction, the geometry 50. A rotary toothed wheel 51, which is of the linkages being such that the clamping driven by the same motor as the spiked roller 60 pads 1 O' on the two sides of the casing 1 46 is provided in the top of the space 49, that 125 .arc moved in by equal distances. The pads is at the bottom of the inclined partition 47 move in until they meet the bag on the plat To the left of the wall 50 as seen in Figure form 2 and then when a predetermined resis 2, there b a further space within the casing tance to the movement is reached, movement I and this b bounded on its left-hand side 65 ceases. As the lever 12 on the right-hand side by another wall 52. The casing 1 has an opes- 130 CTD025927 4 1,315,853 4 tog in one side leading to this space so that a imptkd on the mikes o. the roller 46 and this 65 truck 53 can be wheeled into it. The upper helps to move the bag forwards between the end of the wall 52 has a bracket 54 support knives 29 and 30 so that 'be cutting of the ing a doctor comb 55 which engages with the slits 60 and 61 b completed. The pan of the 5 surface of the spiked roller 46. bag below the slits is dragged around on the In operation, as already described, a bag spiked roller 46 until it b stripped from the 70 containing for example asbestos fibres, is spikes by the doctor comb 55. Thus the placed on the table 10 is then pushed onto the stripped bag pisses underneath the edge 48 platform 2 which b then raised and tilted as of the partition 47. The asbestos fibre to the 10 already described. While this happens, the bag, however, puses over the top of the edge ram dmm 43 has been rotated to a position 48 of the partition 47 and slida down thb 75 such that the rotary knives 29 and 30 occupy partition towards the toothed wheel 51 which the positions shown in Figure 1 of the draw breaks up any cohesive lumps of fibre and the ings. The knives themselves are already rotat- fibre falls into the space 49. The bottom of 15 tog. the space 49 b provided with a conveyor belt As the platform 2 tilts, the bag runs down or other means by which the asebestos fibre 80 the rollers 3 until its leading end engages b fenced d--^ an opezir; h thr casing with the knife 29 and is slit. The forward movement of the bag on the rollers 3 and Since the pan of the bag 58 below the slits 20 thence on the rollers 45 is arrested by a freely 57, 59, 60 and 61 remains joined to the pan rotating wheel 56 which is mounted on the of the bag above the slits at the trailing end 85 shaft of the motor 31 coaxially with the of the bag, the pan of the bag above the slits knife 29. The wheel 56 thus limits the pene b also dragged down by the spiked roller 46 tration of the knife 29. The knife 30 is pro- below the partition 47 and when the bag 25 vided with a similar freely rotatable wheel has been entirely stripped from the spiked which is not shown. roller 46 by the doctor comb 55 It falls into 90 When the bag is arrested by the wheel 56, the truck 53. the pneumatic ram 26 is operated to move the As soon as the trailing end of the bag has damping pads lO' inwards. These hold the left the rollers 3 and b supported entirely on 30 bag and since their inward movement is the rollers 45, the hobt platform 2 is lowered stopped by the bag to the manner already into the position shown at 2' ready to receive 95 described, they also act as feelers for sensing the next bag which b at once raised on the the width of the bag and set the operating platform 2. During this time the cam drum member 28, which forms a stop, in a position 43 b rotated further to return the knives 29 35 which is dependent upon the bag width. and 30 to their starting positions. At this stage, the motor which rotates the ram drum 43 is started and the rotary knife 29 swings outwards to a clockwise direction as seen in Figure 1. This causes it to make a 40 cut 57 across the end of the bag 58 as shown in Figure 4. At the tame time the knife 30 b swuu towards to form a cut 59 across the remainder of the end of the bag 58. The knives 29 and 30 are slightly indined so that 45 the cuts 57 and 59 are similarly inclined and this ensures that the cuts intersect each other so that the end face of the bag 58 is severed into two parts. As rotation of the cam drum 43 continues, 50 the knife 29 b swung outwards until the arm 44 strikes the operating member 28 and stops the motor driving the cam drum. During this rotation, the knife 30 has been swung out The wheels 56 are preferably made of aluminium or other low density material to reduce their ingular momentum as far as possible *o that they can be ouickly stopped by the contact of the bag with them ana in this way wearing a way of the bag by the wheel b prevented and the penetration of the rotary knife into the bag b reliably controlled. Preferably, particularly to the case of a machine for removing asbestos fibre from bags, where there b s health hazard, the casing 1 is connected to a suction fan by which the pressure within the casing b reduced and dust from the fibre b drawn away. Since during the time that the fibre b in motion it b always within pans of the machine surrounded by the casing 1, the escape of any asbestos dust into the atmosphere b prevented. 100 105 HO 115 wards again ami it stops in a position which 55 b symmetrical to the position of the knife 29, but on the other side of the centre line of the beg. WHAT WE CLAIM IS: -- 1. A machine for removing a fibrous material from bags, the machine comprising a support for supporting a bag of die material 120 The damping pads 10' arc then released in a lying position to engagement with a cutter, and the bag rs moved by gravity further dov-n- a mechanism for moving the bag and the 60 wards along the conveyor rollers 3 and 45 cutter relatively to each other to cut the bag so that the knives 29 and 30 start to make slits along one end and along the adjacent sides, or 125 60 and 61 respectively in the sides of the bag along one end, one adjacent side and the 58. After the bag has moved a short distance, other end, and a stripping device which grips in iwvUntt, fvtnw rlv rntt t7 firvt S 0 t. Mrf nC tk twlvMi tk aw/I I* 'NT PUBLICATIONS 1' mtMHtsto 1,315,853 w*y from its contents tnd in so doing mores 8. A machine according to daim 7 in which the bag and its cootents towards the edge of fedm arc provided for sensing the width of 65 a separating partition which is adjacent the the bag and these feelers control the mech stripping device so that the stripped beg anism by which the knives are rvrung to limit 5 passes oo one side of the partition and the the movement of the knives apart from each contents pass on the other side of the partition. other in dependence upon the width of the bag 2. A machine according to claim 1, in which which has been sensed. 70 the support b a platform on which the bag 9. A machine according to claim 8, in moves towards the stripping device and b which the feelers are formed by damping pads 10 slit by the cutter during its movement, the which are moved laterally inwards and grip trailing end of the bag remaining unslit and the tides of the bag between them to bold the the stripping device being arranged to draw bag wiiik its leading end is ltf. 75 the bottom pan of the bag beknr the slit 10. A machine according to daim 9 in onwards in its direction of movement and which the clamping pads are connected to a 15 downwards closely below a substantially hori stop which b set in a position dependent upon zontal edge of the partition which slopes the position into *-* -limping ***ds downwards from this edge. move inwards to grip/the bag, the stop operat 80 3. A machine according to claim 2 in which ing a limit switch on the mechanism which the platform includes a series of freely rout- swings the knives and stops this swinging 20 able conveyor rollers and the platform b movement when the knives are at a distance inclined downwards towards the stripping apart which is dependent upon the position of device so that the bag is moved towards the the stop and thus also dependent on the width 85 stripping device by gravity. of the bag as determined by the distance 4. A machine according to claim 2 or claim between the damping pads. 25 3 in which the stripping device comprises a 11. A machine according to any one of power-driven spiked roller the spikes of which darms 5 to 10, in which the planes in which are arranged to pierce the part of the bag the rotary knives are swung are slightly 90 below the slit and draw it away from in con indined out of the horizontal in opposite tents as the roller routes and rotation of the directions to ensure that the slits made by the 30 roller taking place in a direction which assist*, knives across the end of the bag intersect the passage of the ba on its platform past each other. the cutter to the partition. 12. A machine according to any one of 95 5. A machine according to any one of the claims'5 to 11, in which each rotary knife has preceding claims in which the cutter com- a driving shaft on which a wheel is freely 35 prises a pair of roury knives each of which b rotatably mounted, the wheel limiting the mounted on an arm which is pivoted about an penetration of the knife info the hag. upright axis to enable the knife to swin along 13. A machine according to any one of 100 a substantially horizontally disposed arc of claims 5 to 12 in which the knives are swung movement which extends across the path of by cam followers on the ends of levers, the 40 movement of the bag from the tupport towards cam folk)wen engaging in grooves in a rotary the stripping device. cam drum. 6. A machine according to claim 5 in 14. A machine according to daira 9 or 105 which the knives are swung by a mechanism claim 10, or daim 11, or daim 12 or eltim which operates so that initially one rotary 13 when dependent upon daim 9 or <~ltm 10, 45 knife b disposed directly in the path of move in which the clamping pads are intercon ment of the bag so that this knife forms a nected through two-armed fevers and connect slit in the of the bag as the bag mom ing rods and are movable towards and away 110 towards it, ihe two knives are then swung from each other by a fluid pressure-operated with each other across the path of movement ram acting on one of the fevers. SO of the bag so that the first knife extends its 15. A machine according to daim 4, or slit to one side of the bag and the second any one of claims J to 14 when dependent knife makes a slit from the other side of the upon daim 4, in which there b a doctor comb 115 bag extending towards and intersecting the engaging with the periphery of the spiked slit made by the first knife. roller for stripping the tigs from the spikes. 55 7. A machine according to claim 6 in which 16. A machine according to daim 2, or the mechanism .operates in such a way that any one of datms 3 to 15 when dependent after the knives have been swung across the upon daim 2, in which a rotary toothed whed 120 path of movement of the bag to slit the end b provided at the bottom of die partition for of the bag, they are swung apart from each breaking up cohesive lumps of fibre as the 60 other so that the bag passes between them fibre falls from the partition. tnd the knives extend their slits from the 17. A machine according to any one of the leading end of the bag along its two sides and preceding daims which has a surrounding 125 leave the trailing cod of the bag unslh. casing connected to a suction fan which b CTD025929 6 1,315,85$ arranged to reduce die pleasure within the cosing and draw away any dust there may be ia the materia] from the bags. 18. A machine according to rfarm 1 con 5 structed cod arranged to operate substantially as described with reference to the accompany ing drawings. For the Applicants: -- GILL, JENNINGS 4 EVERY, Chartered Patent Agents, 51/52 Chancery Lane, London, WC2A 1HN. Printed fur lier Utjntj'i Stationery Office, by the Courier Pres, Leamington Spa, 1973. Published by The Patent Office, 25 Southampton Buildings, London, WC2A JAY, from which copies may be obtained. sawiWiS3*3 CTD025930