INLET DEVICE

Description

Field of invention

[0001] The present invention relates to a feed device for a conveying system for preforms. Background of the invention

[0002] A feeding device for supplying thermoplastic preforms with a support ring at the open end to a blow molding machine for the production of, in particular, PET plastic bottles is described, for example, in DE 203 08 513 U1. The device has a silo positioned near the ground for the random storage of a large number of preforms, which is periodically filled from the top by pouring in the preforms delivered in boxes. Near the silo, a roller sorter with two counter-rotating, cylindrical rollers is positioned close to the ground and is slightly inclined downwards in the direction of transport. An inclined conveyor removes the preforms from the bottom of the silo in a random order and feeds them into the upper end of the roller sorter. The upper end of the roller sorter is located approximately 1 meter above the ground, and the lower end is correspondingly lower.An inclined chute, comprising two spaced-apart support rails, is located directly upstream of the linear furnace's infeed star wheel. The preforms rest on the support rails with their support rings and, driven by gravity, slide between them towards the infeed star wheel. The chute acts as a buffer to ensure uninterrupted feeding of the stretch blow molding machine and therefore accommodates well over 100 preforms. Consequently, its upper end is more than 3 meters above the ground. To overcome the height difference of approximately 2 meters or more between the discharge of the roller sorter, which conventionally forms the preforms fed in at the top into a single row between its two rollers and aligns them with their open ends facing upwards, and the upper infeed end of the chute, a vertical conveyor is interposed.

[0003] Another feeding device for preforms is described, for example, in EP 3 453 648 A1. This feeding device has two opposing transport rails on which the preforms rest with their support ring during transport. Furthermore, the feeding device shown therein has six opposing pairs of belt transport units, which are arranged above the transport rails in such a way that the belts of the belt transport units engage with the threaded section of the preforms and clamp them between the belts with a clamping force. The required clamping force is preferably achieved by spring tension on several belt transport rollers over which the belts of the belt transport units run.The drives of the belt transport units, which are preferably designed as servo motors, apply a torque to the preforms stored in the feed device, which is maintained without the belts slipping.

[0004] EP 3 564 006 B1, US 2006 / 269648 A1, US 2005 / 048159 A1 and EP 0 452 857 A1 disclosed, in principle, a feed device for a conveyor system for preforms, which is designed to convey preforms coming from an upstream module of the conveyor system to a downstream module of the conveyor system in an orderly manner, wherein the feed device comprises a first and a second conveyor belt, each guided over at least two rollers, wherein a conveying section for the preforms is formed between a first belt section of the first conveyor belt and a second belt section of the second conveyor belt, wherein the first and the second conveyor belt are arranged such that a lateral edge surface of the first conveyor belt and a lateral edge surface of the second conveyor belt form a support for a carrying ring of a preform, wherein the support can be brought into engagement with the underside of the carrying ring in such a way thatthat a stagnant force is applied to the preform located in the conveying section in the conveying direction. Description of the invention

[0005] For feed devices for preforms, it is typically desirable to simplify the design, for example by reducing the number of components and arranging the device near the ground with a slight incline of the conveying path. At the same time, it is desirable to ensure adequate hygiene, as the containers blown from the preforms are usually filled with beverages intended for consumption.

[0006] It is therefore an object of the present invention to provide a feed device for a conveying system for preforms and a conveying system with such a feed device, which improves upon the state of the art at least partially.

[0007] This problem is solved by a feed device having the features of independent claim 1. Advantageous embodiments of the invention are given in the dependent claims and in the present description as well as in the figures.

[0008] The present disclosure relates to a feed device for a conveyor system for preforms, which is configured to convey preforms coming from an upstream module of the conveyor system to a downstream module of the conveyor system, wherein the feed device comprises a first and a second conveyor belt, each guided over at least two rollers, wherein a conveying section for the preforms is formed between a first belt section of the first conveyor belt and a second belt section of the second conveyor belt, wherein the first and the second conveyor belt are arranged such that a lateral edge surface of the first conveyor belt and a lateral edge surface of the second conveyor belt form a support for a carrying ring of a preform, wherein the support can be brought into engagement with the underside of the carrying ring in such a way thatthat a stagnant force is applied to the preform located in the conveying section in the conveying direction.

[0009] The preforms are preferably made of polyethylene terephthalate and generally have an external threaded section in the region of their opening, to which an outwardly projecting support ring is attached. Below the support ring, a typically elongated, essentially cylindrical section with a rounded, closed end is attached. In certain preforms, the elongated section may have a conical subsection located below the support ring. In the context of the present invention, "orderly conveyed preforms" are understood to mean preforms conveyed upright, with the opening facing upwards, and in a series.

[0010] The infeed device offers the advantage that the conveyor belts provide both a support for the preform's carrying ring, facilitating the conveying of the preforms along the conveyor line, and the application of a back pressure or stagnation force to the preforms accumulated in the conveyor line. In particular, a transport rail for the carrying rings or preforms can be omitted, simplifying the design of the infeed device. Furthermore, since the conveying of the preforms does not rely on sliding on transport rails, there is no need for a significant gradient in the conveying direction along the conveyor line. The infeed device also improves hygiene, as the threaded section of the preform being conveyed remains unobstructed during conveying, i.e., it is not in contact with any components.Furthermore, compared to devices where the preform is clamped to the threaded section, it is not necessary to generate a clamping force.

[0011] Advantageously, the conveying section defined by the infeed device provides a buffer section in which the preforms can be accumulated and filled. Accumulating preforms in the infeed device enables an efficient and reliable transfer of the preforms to a downstream discharge device, particularly a singulation device.

[0012] In one embodiment of the feed device, a surface of the first and second conveyor belt oriented perpendicular to the edge surface forms two opposing stabilizing surfaces for the section of the preform adjoining below the support ring, which can be brought into engagement with the section of the preform adjoining below the support ring in such a way that a deflection of the preform located in the conveying path transversely to the conveying direction is limited and optionally the conveying of the preform is supported.

[0013] The stabilizing surfaces of the conveyor belts limit the deflection of the preforms transversely to the conveying direction. This is particularly advantageous when preforms are accumulated, as they tend to deflect transversely when accumulated. Limiting the transverse deflection of the preforms therefore stabilizes them and improves their orderly conveyance in the feed device. For stabilization, it is advantageously sufficient for the stabilizing surfaces to contact the elongated section below the support ring when the transverse deflection becomes excessive. A clamping engagement is therefore generally not required for stabilization purposes.

[0014] Furthermore, the transport of the preforms can be supported by contact with the surfaces of the conveyor belts, which form the stabilizing surfaces. In certain configurations, the stabilizing surfaces can act as driving surfaces and, in addition to the edge surfaces forming a bearing surface, generate a back pressure or pressure on the preforms.

[0015] The conveyor belts of the feed device can therefore advantageously achieve at least a fourfold function, which includes providing a support for the carrying ring, conveying the preforms in the conveying path defined by the conveyor belts or the first and second belt sections, generating a back pressure or stagnation force on the preforms, and stabilizing the preforms in the conveying path.

[0016] In one embodiment, the feed device has a drive for each conveyor belt.

[0017] Alternatively, the feed device has a common drive for the first and second conveyor belts, which is preferably configured to generate a torque between 10 Nm and 12 Nm.

[0018] Using a common drive for both conveyor belts further simplifies the design of the feed device. A reversing gearbox allows the common drive to generate opposite directions of rotation for the first and second conveyor belts. Preferably, a gearbox with a 10:1 reduction ratio is provided, generating a torque of between 10 Nm and 12 Nm at the output, thus providing a torque of between 5 Nm and 6 Nm for each conveyor belt. For example, a motor with a speed of 1000 rpm can be used for the drive, generating a speed of 100 rpm for the conveyor belts.

[0019] In one design, the conveyor belts are made of a plastic material.

[0020] The conveyor belts can be made of materials such as polyurethane, polyester, or polyamide.

[0021] The plastic advantageously provides a suitable frictional force between the conveyor belt and the preform, in particular between the support and the carrying ring, so that conveying of the preform and generation of back pressure or stagnation force is made possible, while at the same time providing a suitable sliding slip as described below.

[0022] In one embodiment, the conveyor belts are designed as toothed belts, wherein the support for a carrying ring of a preform is formed at least partially by side edges of the teeth of the toothed belts.

[0023] Since the teeth of the toothed belts extend perpendicular to the surface of the conveyor belts which serves as a stabilizing surface, the teeth can, in addition to their engagement function in a drive gear, also serve as the support for the carrying ring of a preform through the side edges.

[0024] In one embodiment, the edge surfaces of the conveyor belts, which serve as a support for a carrying ring of a preform, are designed in such a way that, when a limiting tensile force is exceeded on a preform located in the conveyor section, sliding slip occurs between the edge surfaces and the carrying ring of the preform.

[0025] The sliding slip allows the conveyor belt of the infeed device to slip under the support rings of accumulating preforms, thereby allowing further preforms to follow and accumulate in addition to those already accumulating. The conveyor belts of the infeed device can therefore continue to run without interruption even when preforms are accumulating, continuously filling the conveying section of the infeed device. Since the sliding slip only occurs when a critical back pressure is exceeded, it is ensured that a continuous back pressure is exerted on the accumulated preforms. Furthermore, providing a sliding slip prevents the back pressure from becoming excessive.

[0026] To enable sliding slippage, it is advantageous to manufacture the conveyor belts from a suitable plastic. Furthermore, for the provision of sliding slippage, it is advantageous that the conveyor belts do not have to clamp the preform, as already described.

[0027] In certain configurations, sliding slip can also occur between the surfaces designed as stabilizing surfaces and the section of the preform adjoining the support ring.

[0028] Preferably, the stabilizing surfaces of the conveyor belts are vertically aligned.

[0029] Alternatively, the stabilizing surfaces of the conveyor belts can have an inclination of between 5° and 10° relative to the vertical.

[0030] In one embodiment, the conveyor belts each have a stabilizing surface which is designed such that the distance between the conveyor belts in the conveying path preferably increases in the direction away from the support.

[0031] Increasing the distance between the stabilizing surfaces advantageously achieves stabilization for preforms in which the elongated section located below the support ring has a profile that deviates from a straight cylinder. For example, advantageous stabilization can be achieved for a preform with an outwardly curved section or a conically expanding section.

[0032] In one embodiment, the stabilizing surfaces each have a gradation which divides the stabilizing surfaces into a first and a second stabilizing sub-surface.

[0033] The stepped stabilizing surfaces of the conveyor belts can each be designed as an undercut. The stepped design of the stabilizing surfaces preferably increases the distance between the conveyor belts in a stepped fashion. In particular, each stabilizing surface can, by means of the stepped design, have a first and a second stabilizing sub-surface, which can be vertically oriented, wherein the first stabilizing sub-surface preferably adjoins the lateral edge surface forming the support, and the second stabilizing sub-surface is arranged below the first stabilizing sub-surface. The first stabilizing sub-surfaces of the first and second conveyor belts can define a first distance between the conveyor belts, and the second stabilizing sub-surfaces of the first and second conveyor belts can define a second distance between the conveyor belts, wherein the second distance is preferably greater than the first distance.The step-off can include a slope or horizontal surface connecting the first and second stabilizing sub-surfaces.

[0034] In one embodiment, the conveyor belts are arranged such that the conveying path is horizontal. Alternatively, the conveyor belts can be arranged such that the conveying path is inclined in the conveying direction. The conveying path can, for example, have a gradient of between 1° and 20°, preferably between 5° and 10°, relative to the horizontal.

[0035] In one embodiment, the conveyor belts have a width such that the stabilizing surfaces cover at least one twentieth, preferably at least one tenth, particularly preferably at least one fifth, and more preferably at least one quarter of the height of the preform located in the conveyor section.

[0036] By selecting a suitable width for the conveyor belts, the stabilization function can be adjusted as desired.

[0037] In one design, the conveyor belts have a width between 10 and 50 mm.

[0038] According to claim 1, a minimum sensor for detecting preforms is arranged on the downstream section of the conveying path of the feed device and a maximum sensor for detecting preforms is arranged on the upstream section of the conveying path of the feed device.

[0039] The minimum level sensor can detect the presence or absence of preforms and is preferably connected to a control system. If the minimum level sensor no longer detects any preforms within its range, the minimum fill level has been reached, and an alarm signal can be triggered, for example, to eliminate potential malfunctions in upstream units. Simultaneously, the downstream module, such as a blow molding machine, the infeed star wheel of a clamping conveyor, or an inspection system, can be stopped, i.e., production can be interrupted.

[0040] If the maximum sensor does not detect any preforms in its area, the conveying of preforms in the upstream module, e.g. in a roller sorter, can be accelerated to replenish the conveying section in the feed device.

[0041] After the fault that caused the minimum fill level to be undershot has been rectified, production is preferably only restarted once the conveyor section in the feed device is refilled with preforms, so that the maximum level sensor no longer detects any gaps. Preferably, the minimum level sensor and the maximum level sensor are designed as photoelectric sensors.

[0042] According to claim 1, at least one gap detection sensor, preferably at least two, particularly preferably four or more, gap detection sensors is / are arranged between the minimum sensor and the maximum sensor, which is / are configured to detect gaps in the conveying path between preforms.

[0043] By detecting gaps with gap detection sensors, a catch-up mechanism can be initiated, allowing preforms to be fed more quickly to close these gaps. Preferably, the gap detection sensors are configured to detect gaps between preforms that are comparable to or larger than the diameter of a preform.

[0044] Preferably, the gap detection sensors are designed as light barriers.

[0045] For this purpose, the gap detection sensor or gap detection sensors is / are preferably connected to a control unit which, upon detection of one or more gaps, controls the at least one drive in such a way that the circulation speed of the conveyor belts is increased.

[0046] By increasing the rotational speed of the conveyor belts, gaps can be closed by conveying additional preforms. Due to the sliding slip described above, the conveyor belts can slip under the already accumulated preforms and simultaneously close the gaps by conveying additional preforms, thus effectively making up for any gaps in the feed. Alternatively or additionally, a pre-sorter upstream of the infeed device can be activated so that the pre-sorter conveys additional preforms at a higher speed.

[0047] In one embodiment, at least one pair of opposing air nozzle units are provided below each conveyor belt, which at least temporarily support the transport of the preforms in the conveying direction.

[0048] The air nozzle units preferably feature angled or gill-shaped air nozzles that can direct one or more bursts of air onto the elongated section of the preforms below the support ring. This can be used, for example, if one or more preforms get stuck or jammed in the conveyor, creating a gap. This gap can then be detected by a gap detection sensor, activating the corresponding air nozzle units.

[0049] In certain configurations, the air nozzle units can also support the transfer of the preforms from the feed device to a downstream removal device of the conveying system.

[0050] In one embodiment, the conveyor belts, sensors, and / or air nozzle units are arranged in a position transverse to the conveyor path, allowing for adjustment by means of a width-adjustment device. This enables the feed device to be adjusted to preforms of different sizes or diameters.

[0051] In one embodiment, the width adjustment device has at least two opposing, lateral mounting profiles, each mounted on support rods that can be moved towards and away from each other. This provides a particularly efficient and precise width adjustment mechanism.

[0052] In one embodiment, the conveyor belts, sensors, and / or air nozzle units are attached to the side mounting profiles. The side mounting profiles preferably each have at least two lateral, one upper, and one lower mounting rail. They are therefore particularly versatile in terms of the number of additional components they can accommodate.

[0053] In one embodiment, a height limiter is provided for the preforms, which can be height-adjustable, e.g., mounted in a guide. Preferably, the height limiter is a C-profile arranged above the opening of the preforms and holds the preforms down in the feed device (and preferably also at the transition to the feed device).

[0054] In one embodiment, the guide is mounted on an upper mounting profile of the inlet device. The height limiter is preferably vertically adjustable via a height adjustment element, which is also mounted on the upper mounting profile. The upper mounting profile preferably corresponds to the side mounting profiles. Cable ducts can be mounted on its side mounting rails. The height adjustment element is preferably designed as a lever assembly, which can be operated externally via a control element.

[0055] The invention further relates to a conveying system for preforms comprising a feed device according to the invention and a plurality of preforms which are conveyed at variable distances from each other in the conveying section of the feed device, wherein a stagnation force or stagnation pressure can be applied to the preforms in a downstream section of the conveying section of the feed device.

[0056] In one embodiment of the conveying system, the infeed device is arranged downstream of a stacking sorter, preferably a roller sorter or centrifugal sorter, and upstream of a discharge device, preferably an infeed star or infeed rollers.

[0057] In one embodiment of the conveyor system, the conveyor system includes a control unit which is connected to the minimum sensor and / or the maximum sensor and / or the gap detection sensors of the feed device, and which, upon detection of one or more gaps, controls the at least one drive in such a way that the circulation speed of the conveyor belts is increased. List of characters

[0058] Exemplary embodiments of the invention are explained in more detail with reference to the following figures and the accompanying description. They schematically show: Figure 1 is a perspective view of an embodiment of an inlet device according to the invention; Figure 2 is a frontal view of a section of the inlet device made of Figure 1 Figure 3 shows a section of a perspective sectional view of the inlet device. Figure 1Figure 4 shows a top view of an embodiment of a conveyor system; Figure 5 shows a sectional view of a section of an embodiment of an infeed device according to the invention. Description of exemplary embodiments

[0059] Figure 1 Figure 1 shows a perspective view of an embodiment of a feed device 1 comprising two frames 161 and 162, each with a width adjustment device 18. The width adjustment device 18 comprises two support rods 181, which can be moved towards and away from each other via a spindle. A lateral mounting profile 13 is mounted on each of the support rods 181. A minimum sensor 21, two gap detection sensors 22, 23, 24, and a maximum sensor 25 are mounted on the lateral mounting profiles 13. These sensors are designed as light barriers with corresponding reflectors 211, 221, 231, 241, 251.

[0060] Preforms 4, for example, from a roller sorter, are transferred via a transfer section 3 to the infeed device 1. The preforms 4 lie on the lateral edge surfaces of a first conveyor belt 11 and a second conveyor belt 12 (partially concealed in Figure 1 ) over the support ring and are conveyed in conveying direction F in a conveying section formed between a first belt section of the first conveyor belt 11 and a second belt section of the second conveyor belt 12.

[0061] Mounting plates 14 are mounted on the lateral mounting profiles 13. A first drive 111 for the first conveyor belt 11 and a second drive 121 for the second conveyor belt 12 are arranged on each mounting plate 14, driving rollers 112 and 122, respectively. The first conveyor belt 11 runs over rollers 112 and 113, and the second conveyor belt 12 runs over rollers 122 and 123. Furthermore, outer guide rollers are provided for both conveyor belts 11 and 12.

[0062] The conveyor belts 11, 12 are designed as toothed belts and run over two gears 114 and 124 each (the second gear for the second conveyor belt 12 in the area of ​​the roller 123 is in the Figure 1 (covered and not visible). The one in the Figure 1 upward-oriented side edges of the teeth of the timing belt (not shown in the Figure 1 ) form the support for the carrying ring of the preform 4.

[0063] In the upper area of ​​the feed device, an upper mounting profile 15 is arranged, which is attached to the frames 161, 162. Cable ducts 151, 152 are attached to the sides of the upper mounting profile 15. Height adjustment elements 171 are also attached to the upper mounting profile 15, which hold a height limiter 17 above the preform 4. The height limiter 17 (as well as other elements of the feed device 1, such as parts of the conveyor belts) is shown partially transparent for better visibility of the preform 4.

[0064] Under normal operating conditions, the conveying section of the infeed device 1 is preferably filled with preforms 4 along its entire length. If one of the gap detection sensors 22, 23, 24 detects a gap in its detection range, the drives 111 and 121, for example, are driven at a higher speed to convey more preforms and close the gap. If the minimum level sensor 21 no longer detects any preforms in its range, the minimum fill level has been reached, and an alarm signal can be triggered, for example, so that potential malfunctions in upstream units can be rectified. Simultaneously, a downstream device, such as a blow molding machine, the infeed star wheel of a clamping conveyor, or an inspection system, can be stopped, i.e., production can be interrupted.

[0065] The conveying section of the feed device 1 is horizontally oriented, which allows for installation near the ground. However, it is also conceivable that the conveying section has a gradient of between 1° and 20°, preferably between 5° and 10°, relative to the horizontal.

[0066] Figure 2 shows a frontal view of the inlet device 1 from Figure 1 As in the Figure 2As can be seen, the preform 4 rests on the lateral edge surfaces 110 and 120 of the toothed conveyor belts 11 and 12 via the support ring 41. The edge surfaces 110 and 120, which are formed by the upper side edges of the teeth of the toothed belts, thus form a bearing surface for the support ring 41 of the preform 4. The frictional force between the edge surfaces 110 and 120 of the conveyor belts 11 and 12 and the support ring 41 causes the bearing surface to engage with the support ring 41 in such a way that a clamping force is applied to the preform located in the conveying path in the conveying direction.

[0067] The distance between the conveyor belts 11 and 12 is adjusted via the width adjustment device 18 such that there is sufficient space between the conveyor belts 11 and 12 for the preform 4. Furthermore, the surfaces 113 and 123 of the first and second conveyor belts 11 and 12, which are perpendicular to the lateral edge surfaces 110 and 120, form stabilizing surfaces for the preform 4, limiting its lateral deflection. By appropriately adjusting the distance between the conveyor belts 11 and 12, the surfaces 115 and 125 can also contact the elongated section of the preform 4 below the support ring 41 (here, the conical section) and assist in conveying the preform 4.

[0068] In the embodiment shown, the conveyor belts 11 and 12 are made of polyurethane. The infeed device 1 further comprises additional deflection limiting elements 5.

[0069] Conveyor belts 11 and 12 are, as already mentioned in Figure 1 As shown, driven by drives 111 and 121. As already described, it is also possible to drive the conveyor belts 11 and 12 by a common drive with a suitable reversing gearbox.

[0070] The height limiter 17 is vertically adjustable via height adjustment elements 171 in the form of a lever arrangement. The other already mentioned Figure 1 The components of the inlet device described above are designated with corresponding reference numerals.

[0071] Figure 3 shows a section of a perspective sectional view of the inlet device 1 from Figure 1 . In the sectional view, half of the preform 4 can be seen, the support ring 41 of which rests on one side on the upper side edges of the teeth 116 of the conveyor belt 11 designed as a toothed belt.

[0072] Figure 4shows a top view of an embodiment of a conveying system 10 for preforms comprising the infeed device 1. Figure 1 Cartons containing preforms are conveyed via the conveyor roller belt 102 to the tipping device 103, which picks up one carton at a time and empties the contents, i.e., the preforms, onto a conveyor belt assembly 104. The conveyor belt assembly 104 comprises a first conveyor belt 105, a funnel-shaped device 106, and a second (transverse) conveyor belt located below the funnel-shaped device 106. The first conveyor belt 105 and the funnel-shaped device 106 each have a cover 107. The second conveyor belt transfers the preforms in random order to an upfeed conveyor 108. A roller sorter 109 with a return conveyor 109a is connected to the upfeed conveyor 108.

[0073] Downstream of the upstream module designed as a roller sorter 109, the feed device 1 is provided, which takes the correctly aligned, i.e. ordered, preforms from the roller sorter 109 and leads them to a downstream module designed as an inlet star of a clamping conveyor 1011.

[0074] A discharge rail 1012 connects to the clamping conveyor 1011, via which the individual preforms are conveyed to the stretch blow molding machine 1013. The infeed device 1 can also guide the preforms directly to a stretch blow molding machine 1013 or to its infeed star wheel. Furthermore, a control unit 1014 is shown, which is connected to the minimum and maximum sensors, the gap sensors, the drives of the conveyor belts, and, if applicable, the roller sorter 109 for receiving detection signals and for control purposes.

[0075] Figure 5Figure 1 shows a sectional view of a section of an embodiment of a feed device 1' with a first conveyor belt 11' and a second conveyor belt 12'. The first and second conveyor belts 11', 12' each have a lateral edge surface 110', 120' which forms a support for a carrying ring 41' of a preform 4'. The first and second conveyor belts 11', 12' each have a stabilizing surface 115', 125' which, positioned opposite each other, serve to stabilize a section 42' of the preform 4' adjoining the carrying ring 41'. The stabilizing surfaces 115', 125' each have a step, so that the stabilizing surfaces 115', 125' each comprise a first stabilizing sub-surface 1151', 1251' and a second stabilizing sub-surface 1152', 1252', which is arranged below the first stabilizing sub-surface 1151', 1251'.The step is designed as an undercut, so that the distance between the conveyor belts 11', 12' in the conveyor section is in the direction away from the support, i.e. in the direction shown. Figure 5 downwards, enlarged in steps. The step-off includes a slope connecting the first stabilizing sub-surface 1151', 1251' and the second stabilizing sub-surface 1152', 1252'. As in the Figure 5As can be seen, the stepped stabilizing surfaces 115', 125' stabilize the section 42', which is arranged below the support ring 41' and has a conical shape. A straight cylindrical section 43' adjoins the conically widening section 42'. It is evident that the stepped stabilizing surfaces 115', 125' can also be advantageous, for example, for stabilizing a preform with an outwardly convex section located below the support ring. Furthermore, the first stabilizing partial surfaces 1151', 1251' are spaced apart from each other such that they engage with a vertical section 44' of the preform 4' and can assist in conveying the preform 4'.

Claims

1. Feed device (1, 1') for a conveyor system (10) for preforms (4, 4'), which is designed to convey preforms (4, 4') coming from an upstream module (109) of the conveyor system (10) to a downstream module (1011) of the conveyor system (10), wherein the feed device (1, 1') comprises a first and a second conveyor belt (11, 11'; 12, 12') each guided over at least two rollers (112, 113, 114; 122, 123, 124) respectively, wherein a conveying path for the preforms (4, 4') is formed between a first belt section of the first conveyor belt (11, 11') and a second belt section of the second conveyor belt (12, 12'), wherein the first and second conveyor belts (11, 11'; 12, 12') are arranged in such a way that a lateral edge surface (110, 110') of the first conveyor belt (11, 11') and a lateral edge surface (120, 120') of the second conveyor belt (12, 12') form a support for a support ring (41, 31') of a preform (4, 4'), wherein the support can be engaged with the underside of the support ring (41, 41') in such a way that an accumulation force is applied to the preform (4, 4') located in the conveying path (4, 4') in the conveyor direction (F), wherein a minimum sensor (21, 211) for detecting preforms is arranged at the downstream section of the conveying path of the feed device and a maximum sensor (25, 251) for detecting preforms is arranged at the upstream section of the conveying path of the feed device, wherein at least one gap detection sensor is arranged between the minimum sensor (21, 211) and the maximum sensor (25, 251), which is designed to detect gaps in the conveying path between preforms.

2. Feed device (1, 1') according to claim 1, characterised in that surfaces (115, 115'; 125, 125') of each of the first and second conveyor belts (11, 11'; 12, 12') arranged perpendicular to the edge surfaces (110, 110'; 120, 120') form two opposing stabilising surfaces (115, 115'; 125, 125') for the section of the preform (4, 4') adjoining the support ring (41, 41') underneath, which can be brought into engagement with the section of the preform (4, 4') adjoining the support ring (41, 41') underneath in such a way that deflection of the preform (4, 4') located in the conveying path transversely to the conveyor direction (F) is limited and, preferably, the conveying of the preform (4, 4') is supported.

3. Feed device (1) according to claim 1 or 2, characterised in that the feed device (1) has a drive (111; 121) for each conveyor belt (11; 12), or that the feed device has a common drive for the first and second conveyor belts, which is preferably designed to generate a torque between 10 Nm and 12 Nm.

4. Feed device (1) according to one of the preceding claims, characterised in that the conveyor belts (11; 12) are made of a plastic, preferably a polyurethane or a polyester or a polyamide.

5. Feed device (1) according to one of the preceding claims, characterised in that the conveyor belts are designed as toothed belts (11; 12), wherein the support for a support ring (41) of a preform (4) is formed at least partially by side edges of teeth (116) of the toothed belts (11; 12).

6. Feed device (1) according to one of the preceding claims, characterised in that the edge surfaces (110; 120) of the conveyor belts (11; 12) are designed in such a way that, when a threshold accumulation force is exceeded on a preform (4) located in the conveying path, a sliding slip occurs between the edge surfaces (110; 120) and the support ring (41) of the preform.

7. Feed device (1) according to one of claims 2 to 6, characterised in that the stabilising surfaces (115; 125) of the conveyor belts (11; 12) are vertically aligned, or in that the stabilising surfaces of the conveyor belts have an inclination of between 5° and 10° relative to the vertical.

8. Feed device (1') according to one of the preceding claims, characterised in that the conveyor belts (11', 12') each have a stabilising surface (115', 125') which is designed in such a way that the distance between the conveyor belts (11', 12') in the conveying path increases, preferably in the direction away from the support , wherein the stabilising surfaces (115', 125') preferably each have a step which divides the stabilising surfaces (115', 125') into a first stabilising partial surface (1151', 1251') and a second stabilising partial surface (1152', 1252').

9. Feed device (1) according to one of the preceding claims, characterised in that the conveyor belts (11; 12) are arranged in such a way that the conveying path is horizontal.

10. Feed device (1, 1') according to one of the preceding claims, characterised in that the conveyor belts (11, 11'; 12, 12') have a width between 10 and 50 mm.

11. Feed device (1) according to one of the preceding claims, characterised in that at least two, preferably four or more, gap detection sensors (22, 221; 23, 231; 24, 241) are arranged between the minimum sensor (21, 211) and the maximum sensor (25, 251), which are designed to detect gaps in the conveying path between preforms, wherein the gap detection sensors (22, 221; 23, 231; 24, 241) are preferably connected to a control system (1014) which, upon detection of one or more gaps, controls the at least one drive (111; 121) in such a way that the circulation speed of the conveyor belts (11; 12) is increased.

12. Feed device (1) according to one of claims 1 to 10, characterised in that the gap detection sensor (22, 221; 23, 231; 24, 241) is connected to a control system (1014) which, upon detection of one or more gaps, controls the at least one drive (111; 121) in such a way that the rotational speed of the conveyor belts (11; 12) is increased.

13. Conveyor system (10) for preforms, comprising a feed device (1) according to one of the preceding claims and a plurality of preforms (4) which are conveyed at variable distances from one another in the conveying path of the feed device (1), wherein an accumulation force can be applied to the preforms (4) in a downstream section of the conveying path of the feed device (1), wherein the feed device (1) is preferably arranged downstream of a lining up sorter (109), preferably a roller sorter (109) or centrifugal sorter, and upstream of a takeover device (1011), preferably an inlet star or inlet rollers.

14. Conveyor system (10) according to claim 13, characterised in that the conveyor system (10) comprises a control system (1014) which is connected to gap detection sensors (22, 221; 23, 231; 24, 241) of the feed device (1) and is designed to control the at least one drive (111; 121) in such a way that the circulation speed of the conveyor belts (11; 12) is increased when one or more gaps are detected.

15. Conveyor system (10) according to claim 13 or 14, characterised in that the conveyor belts (11, 11'; 12, 12') have a width such that the stabilising surfaces (115, 115'; 125, 125') cover at least one twentieth, preferably at least one tenth, particularly preferably at least one fifth, and further particularly preferably at least one quarter, of the height of the preform (4, 4') located in the conveying path.