Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
  • B65G17/00—Conveyors having an endless traction element, e.g. a chain, transmitting movement to a continuous or substantially-continuous load-carrying surface or to a series of individual load-carriers; Endless-chain conveyors in which the chains form the load-carrying surface
  • B65G17/30—Details; Auxiliary devices
  • B65G17/46—Means for holding or retaining the loads in fixed position on the load-carriers, e.g. magnetic
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
  • B65G19/00—Conveyors comprising an impeller or a series of impellers carried by an endless traction element and arranged to move articles or materials over a supporting surface or underlying material, e.g. endless scraper conveyors
  • B65G19/02—Conveyors comprising an impeller or a series of impellers carried by an endless traction element and arranged to move articles or materials over a supporting surface or underlying material, e.g. endless scraper conveyors for articles, e.g. for containers

Definitions

• the invention relates to a device for transporting flat objects according to the preamble of claim 1
• Devices of this type are used, for example, in various processing machines, for example in machines for producing sacks with molded-on bottoms from tubular pieces, which are often formed from a tubular material.
• the sacks or tubular pieces are transported in a transport direction to the various processing stations by the known transport devices, whereby several processing stations can be arranged along a single transport device.
• the flat objects are taken along or pulled along by a conveying means.
• known devices have a counter surface assigned to the conveying means. A clamping force acts between the conveying means and the counter surface which the flat objects are held in operative connection with the conveying means.
• the counterpart is flat if from a means of conveyance Both means of conveyance are in operative connection with the object, so that the object is at rest relative to both means of conveyance and is reliably transported
• a discontinuous transport that is to say a cycle transport
• the objects to be processed being briefly in the area of a processing station Relative to this must be at rest and may only be transported further after processing.
• the objects must also assume a defined position in their rest position relative to the processing station.
• the flat objects may also only have certain positions relative to the processing device Take receivables
• a disadvantage of the devices for transporting flat objects mentioned, however, is that the detection of the flat objects at the inlet-side end of the transport device takes place only at very imprecisely defined times.This is particularly the case when an object is transported continuously to a device for discontinuous transport This means that the positions of the flat objects relative to the conveying means are often subject to major errors, and incorrect processing of the objects is the result
• the conveying means has at least two driver elements which are offset with respect to one another in the transport direction of the flat objects and in the transport direction and which conveys at least part of the clamping force mentioned on the flat objects it comes into frictional engagement with a driver element
• the entry area and the transfer of the object are designed in such a way that the driver element always detects an object in essentially the same areas.Each object to be transported thus occupies a fixed position relative to the conveying device.
• the holding means move like the objects in the direction of transport, but do not need to be connected to the conveying means
• the distance of the individual driver elements depends on the cycle time in the discontinuous transport and is at least the extent of the flat objects in the transport direction, for example at least 400 mm.
• the counterpart can move at the same speed as the funding, but can move more slowly or be at rest. In the latter two cases, the objects slide or slide along the counter surface. To ensure this, the ratio of the static frictional force of the driver element to the sliding frictional force of the counterpart must be greater than 1. These two frictional forces depend on various parameters, which are selected according to the requirements.
• the counter-layer made of a metal and the driver element on the surface which is in contact with the object can be coated with a rough material.
• other tools can also be used to influence the frictional forces.
• the backing can be wetted with a lubricant.
• the driver element can have an electrostatic charge, so that the object, if it is an electrically insulating material, is attracted electrostatically by the driver element.
• the counterpart usually consists of a non-compliant material, so that the object is always pressed against the counterpart by the driver element with constant force and in the same position.
• the at least one conveying means is at least one circulating, endless means of transport such as a belt, a belt, a chain or a wheel.
• a link chain is advantageous here. Such a link chain can be driven via gears.
• each driver element can be displaced in the direction of the counter position in order to impart the clamping force. If there is no flat object, the components of the driver element do not need to be moved for the purpose of clamping. This measure prevents Excessive wear of the components of the driving element, the conveyor and / or the counterpart.
• the at least one conveying means advantageously has at least two holding pieces, in which at least components of the driver elements are slidably mounted.
• Such holding pieces are particularly easy to attach to the side of link chains.
• the holding pieces can be of an angular design and have bores, so that pin-like components of the driver element can be slidably supported in these bores.
• Each driver element preferably has a compressible material on the side facing the counter surface, with which the operative connection of the flat objects to the at least one conveying means can be established.
• a compressible material for example silicone rubber or rubber.
• Such materials increase the static friction between the driver element and the flat object.
• This compressible material can be applied separately to each driver element, but a band-shaped material can also be used, which also spans the spaces between the driver elements and thus further increases the static friction.
• the compressible material can also be surrounded by spacers which protrude beyond the compressible material in such a way that if a flat object is absent, the compressible material does not come into contact with the counter surface.
• the first component is arranged in or on the counter surface and the second component in or on the driver element.
• the first component is advantageously a spring steel sheet, which serves as a counter-support or is part of the counter-support.
• the spring steel sheet can be arranged so that the objects slide on it. In this way, a property of steel, namely a low coefficient of sliding friction, can be exploited in an advantageous manner.
• the second component is a magnet arranged on the driver element.
• This can be a permanent magnet or a switchable magnet in any way. In this way, the magnetic force acts only in the area of the driver element.
• the driver element comprises a spring which counteracts the magnetic force and is greater than this when the distance between the two components between which the magnetic interaction occurs exceeds a minimum distance.
• This function of the spring is preceded by the consideration that the magnetic force between the entraining element and the counter-position becomes greater as the distance becomes smaller, whereby there is approximately a quadratic dependence.
• the spring force becomes greater than the magnetic attraction force.
• the driver element is pulled away from the counter surface.
• the driver element can thus be switched back and forth between an active position in which the flat object is guided in a clamping manner and a passive position. This switching can take place through mechanical constraining forces, for example through control cams, but also through an increase or decrease in the magnetic force.
• this switching can be carried out selectively for each driver element. This prevents the head of the driver element from sliding along the counter surface if an object is absent and thus leads to undesired wear.
• part of the counter-position can also be movable in the direction of and away from the conveying means. In the absence of the counter position, no magnetic force acts on the driver element, so that it is returned to its starting gear position due to the spring force. The counter position is only moved in the direction of the conveying means when a flat object is present. The presence of a flat object can be determined by a sensor which transmits a corresponding signal to a control device which causes the part of the counterpart to move.
• Such a device according to the invention is preferably used in a device for producing fabric bags, the starting product of which is a round-woven, tubular material.
• Fig. 1 is a schematic representation of a transport device according to the invention.
• Fig. 2 is a representation of a driver element
• FIG. 3 View III-III according to Fig. 2
• Fig. 4 shows an embodiment of the inlet area of a device according to the invention
• FIG. 1 shows a schematic representation of a transport device 1.
• This comprises a circulating, endless link chain 2 serving as a conveying means, which is driven or deflected via gear wheels 3, which can be mounted in the machine frame.
• At least two driver elements 4 are attached to the side of the link chain 2.
• a plurality of such driver elements 4 is generally provided in a transport device according to the invention. In Figure 1, two driver elements are shown, the driver element 4a in an extended, active and the driver element 4b is shown in a retracted, passive position.
• a table 6 is arranged, the surface of which represents the conveying plane for the flat objects 5 to be transported, for example tubular plastic materials.
• the flat objects 5 are conveyed in the transport direction z.
• a driver element 4a, 4b consists of a holding piece 7, in which a bolt 8 is slidably mounted. The displacement takes place in a direction of the double arrow B. This direction is essentially orthogonal to the conveyor plane defined by the top of the table 6.
• the bolt 8 passing through the holding piece 7 carries a disc 9 at its foot end.
• a compression spring 10 surrounds the bolt 8, which acts in such a way that the driver element 4a, 4b is retracted without any other force , passive position remains, as illustrated by the driver element 4b.
• the driver element 4a is shown in its extended position. So that the driver element 4a remains in this position, its head 11 is equipped with a permanent magnet 12. Above a slot made in the table 6, through which the driver element 4a can extend, a counter support 13 made of spring steel is fastened. If the permanent magnet 12 comes close enough to the counter-surface 13, the permanent magnet 12 interacts with the spring band steel, so that the entire head 11 and the bolt 8 are moved in the direction of the counter-surface 13 against the force of the spring 10. until the flat object 5 is clamped between the head 11 and the counter-surface 13. In order to achieve such a close distance, there is a guide 15 below the inlet area 14 of the counter-support 13, which raises the bolt 8 against the force of the compression spring 10. FIG.
• the head 11 comprises an articulated connection 16, the inner, convex-shaped ring 17 of which is attached to the upper end of the bolt 8.
• the outer ring 18 of the articulated connection 16 is inserted into a bore in the magnet carrier 19.
• the ring-shaped or disk-shaped permanent magnet 12 is fastened in an upper recess of the magnet carrier 19 in a manner not shown in detail.
• the articulated connection 16 ensures that the surface of the permanent magnet 12 facing the counter surface 13 always runs plane-parallel to the counter surface 13. This is important because the bolt 8 of the driver element 4a, 4b is not orthogonal to the counter surface 13 in all operating situations due to the use of a flexible pulling element, for example in the case of an accelerated movement in clocked mode with a high clock frequency.
• a compressible coating 20 is bonded to the surface of the permanent magnet 12 facing the counter-surface 13, which causes high static friction when it comes into contact with a flat object 5, so that the flat objects 5 to be transported are at rest relative to the driving element 4a. This is particularly important in the case of accelerated movements in cyclical operation of a device according to the invention.
• the compressible covering 20 can consist of a silicone rubber or similar material.
• the upper edge 21 of the magnet carrier 19 is covered with needle-shaped but blunt spacers 22, which just overhang the compressible covering 20.
• the blunt spacers 22 additionally press a little into the material of the flat object 5, so that the latter is additionally held in this way.
• FIG. 3 shows the view III-III according to FIG. 2, from which it can be seen how the driver element 4 is preferably attached to a link chain 2.
• a Holding plate 23 On the side of the holding piece 7 which carries the driving element 4a, b is a Holding plate 23 arranged. Two chain rivets 24 are fastened to this holding plate 23 orthogonally thereto. These chain rivets 24 thus also serve to connect two link plates as well as to carry the driving element 4a, b.
• FIG. 4 shows the inlet-side section of a further embodiment of a device according to the invention. Compared to FIGS. 1 to 3, the transport direction z of the flat objects not shown here has been reversed. All components that are not necessary for understanding the functioning of the infeed of the objects were not shown in FIG. 4.
• a force acts on the disk 9 due to the guide 15, which causes the bolt 8 to be lifted.
• the plate 25 is lowered.
• the plate 25 is connected to any lifting mechanism via a piston 26.
• This can be a simple piston-cylinder unit, but also any other actuator. Only after the lowering process can forces 12 form between the plate 25 and the magnet, on the basis of which the driver element 4 and the plate 25 can hold the flat object in a clamping manner. As long as the head 11 of the driver element 4 is not yet in the area of the counter-surface 13, the plate 25 remains lowered. Only then will it be moved back to its starting position.
• the plate 25 remains in its starting position. Since only very weak magnetic forces form between the magnet 12 and the plate 25, the bolt 8 falls back into its starting position after it has passed over the end region 27 of the guide 15. The distance between the magnet 12 and the counter support 13 is now too large, so that the driver element 4 does not move in the direction of the counter support. Overall, a selective activation of individual driver elements depending on the presence of a flat object is achieved in the manner described.
• the structure of the head 11 shown in FIG. 4 differs from that as shown in FIGS. 2 and 3.
• the magnet 12 is annular.
• a compressible element 28, which has a cylindrical shape, is embedded in the central hole.
• a rubber block can be used as the compressible element 28.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Feeding Of Articles By Means Other Than Belts Or Rollers (AREA)
• Advancing Webs (AREA)
• Belt Conveyors (AREA)
• Auxiliary Devices For And Details Of Packaging Control (AREA)

Priority Applications (6)

Applications Claiming Priority (2)

Publications (1)

Family

ID=34962102

Family Applications (1)

Country Status (8)

Cited By (1)

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Citations (3)

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• 2004
  • 2004-03-15 DE DE102004012755A patent/DE102004012755B4/de not_active Expired - Fee Related
• 2005
  • 2005-03-10 WO PCT/EP2005/002602 patent/WO2005092747A1/de not_active Ceased
  • 2005-03-10 BR BRPI0508705-8A patent/BRPI0508705A/pt active Search and Examination
  • 2005-03-10 JP JP2007503249A patent/JP5060283B2/ja not_active Expired - Fee Related
  • 2005-03-10 AT AT05715968T patent/ATE494245T1/de active
  • 2005-03-10 ES ES05715968T patent/ES2357583T3/es not_active Expired - Lifetime
  • 2005-03-10 EP EP05715968A patent/EP1735224B1/de not_active Expired - Lifetime
  • 2005-03-10 CN CN200580008216.1A patent/CN1930061B/zh not_active Expired - Fee Related
  • 2005-03-10 DE DE502005010800T patent/DE502005010800D1/de not_active Expired - Lifetime

Patent Citations (3)

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