CONVEYING THROUGH FURNACES

Abstract

A conveyor unit for moving products in a conveying direction is disclosed. The unit comprises first beams extending along the conveying direction substantially parallel to each other. The first beams are slidably mounted on rollers and are displaceable in a back-and-forth reciprocating motion along the conveying direction between an upstream position and a downstream position. The unit further comprises second beams extending along the conveying direction and arranged interleaved with the first beams. The second beams are configured to be displaceable in an up-and-down reciprocating motion between a lower vertical position and an upper vertical position along a vertical direction that is defined in a plane substantially perpendicular to a plane of the conveying direction, wherein an upper working surface of the first beams is positioned along the vertical direction, between the lower vertical position and the upper vertical position.

Claims

1. A conveyor unit for moving products in a conveying direction through a furnace, the unit comprising a plurality of first elongated beams extending along the conveying direction and arranged substantially parallel to each other, wherein the first beams are slidably mounted on rollers and are configured to be displaceable in a back-and-forth reciprocating motion along the conveying direction between an upstream position and a downstream position, a plurality of second elongated beams extending along the conveying direction and arranged interleaved with the first beams, wherein the second beams are configured to be displaceable in an up-and-down reciprocating motion between a lower vertical position and an upper vertical position along a vertical direction that is defined in a plane substantially perpendicular to a plane of the conveying direction, wherein an upper working surface of the first beams that in use supports the products is positioned along the vertical direction, between the lower vertical position and the upper vertical position.

2. The system of claim 1, wherein the rollers are defined by outer protrusions circumferentially provided on one or more rotatable shafts, the shafts being arranged substantially transversally to the first beams.

3. The system of any of claim 1 or 2, wherein the first beams comprise an inverted U-shaped cross-section.

4. The system of any of claims 1-3, comprising a driving mechanism for providing a linear back-and-forth reciprocating motion to the first beams.

5. The system of any of claims 1-4, comprising a motor drive for rotating one or more rollers.

6. The system of any of claims 1-5, comprising a driving mechanism for providing a linear up-and-down reciprocating motion to the second beams.

7. A method of moving products in a conveying direction through the conveyor unit of any of claims 1-6, wherein the method comprises providing the first beams in the upstream position and the second beams in the lower vertical position; the method further comprising a) providing one or more products on the first beams at an initial position along the conveying direction corresponding to an initial position along the first beams; b) moving the first beams from the upstream position to the downstream position such that the products reach a first position along the conveying direction while maintaining the initial position with respect to the first beams; c) moving the second beams from the lower vertical position to the upper vertical position such that products are supported by the second beams, at the first position along the conveying direction; d) moving the first beams from the downstream position to the upstream position; and e) moving the second beams from the upper vertical position to the lower vertical position such that products are supported by the first beams, at the first position along the conveying direction which corresponds to a first position along the first beams that is different than the initial position along the first beams.

8. The method of claim 7, further comprising f) moving the first beams with the products at the first position with respect to the first beams from the upstream position to the downstream position such that the products reach a second position along the conveying direction while maintaining the first position with respect to the first beams; g) moving the second beams from the lower vertical position to the upper vertical position such that products are supported by the second beams, at the second position along the conveying direction; h) moving the first beams from the downstream position to the upstream position; and i) moving the second beams from the upper vertical position to the lower vertical position such that products are supported by the first beams, at the second position along the conveying direction which corresponds to a second position along the first beams that is different than the first position along the first beams; and optionally repeating steps f) to i).

9. The method of claim 8, further comprising after step h) j) moving the second beams from the upper vertical position to the lower vertical position such that the products remain supported by the second beams, at the second position along the conveying direction; and k) moving the first beams from the upstream position to the downstream position so as to push the products held by the second beams, from the second position along the conveying direction to a third position along the conveying direction.

10. A continuous furnace comprising a conveyor unit according to any of claims 1-6 for moving products in a conveying direction with the method of any of claims 7-9.

11. The continuous furnace of claim 10, comprising two or more conveyor units according to any of claims 1-6 for moving products in a conveying direction with the method of any of claims 7-9, wherein the first beams of the two or more conveyor units move in unison and the second beams of the two or more conveyor units move in unison.

12. The continuous furnace of claim 11, wherein the first beams of a downstream conveyor unit at an upstream position are partially interleaved with the second beams of an upstream conveyor unit.

13. The continuous furnace of claim 11, wherein the first beams of an upstream conveyor unit at a downstream position are partially interleaved with the second beams of a downstream conveyor unit.

14. The continuous furnace of any of claims 11-13, wherein a path defined by the first beams of an upstream conveyor unit substantially overlaps with a path defined by the first beams of a downstream conveyor unit.

15. The continuous furnace of any of claims 11-14, wherein at any of steps e) or i) when the second beams are moved from the upper vertical position to the lower vertical position the products are supported by the first beams of a downstream conveyor unit.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Non-limiting examples of the present disclosure will be described in the following with reference to the appended drawings, in which:

[0060] FIG. 1 shows a perspective of a conveyor unit according to an example,

[0061] FIGS. 2a and 2b show cross-sectional views at different vertical positions of second beams of the unit of FIG. 1 arranged inside a furnace;

[0062] FIGS. 3a-3d schematically show a sequence of situations occurring during the performance of a method of moving products in a conveying direction through a conveyor unit substantially as hereinbefore described; and

[0063] FIGS. 4a and 4b schematically show how two conveyor units can be put together to build a longer conveyor system.

DETAILED DESCRIPTION OF EXAMPLES

[0064] In these figures the same reference signs have been used to designate matching elements.

[0065] FIG. 1 shows a perspective of an example of a conveyor unit 1 for moving products in a conveying direction (see arrow A in FIGS. 3a-3d). The unit 1 comprises a plurality of first beams 10 that are slidably mounted on rollers 11. In this example, five first beams are provided, however in further examples, other number of first beams may be provided.

[0066] In some examples, the first beams 10 may be mounted to a frame (not shown) that may be connected to a linear driving mechanism (not shown) so as to provide the first beams 10 with a back-and-forth reciprocating motion between an upstream (backwards) position and a downstream (forward) position (see 101 and 102 in FIG. 3a). In examples, the driving mechanism may be any known mechanical, hydraulical or servo-mechanical mechanism providing a linear displacement. Particularly hydraulic pistons driven by a motor, e.g. an electric motor, may be foreseen.

[0067] As further shown in FIG. 1, the rollers 11 are circumferentially provided on rotatable shafts 111 e.g. as outer protrusions thereof. In examples, the rollers may be coupled or fixed to the shafts by e.g. screws or welding. Alternatively, the rollers may be machined with the shafts. In examples, the shaft may be allowed to freely rotate in a passive manner and movement of the first beams may be governed e.g. by driving mechanism configured to provide the back-and-forth reciprocating motion to the first beams. In other examples, a motor may be used to provide rotary motion to the shafts or to one or more of the shafts in order to aid the back-and-forth reciprocating motion. In some of these examples, the rollers may be connected with the driving mechanism configured to provide the back-and-forth reciprocating motion to the first beams (without an additional linear drive mechanism).

[0068] The unit 1 further comprises a plurality of second beams 20 that are arranged interleaved with the first beams 10. A further driving mechanism 21 may be foreseen to provide the second beams 20 with an up-and-down reciprocating motion between a lower vertical position and an upper vertical position (see FIGS. 2a and 2b) along a vertical direction. The vertical direction may be defined in a plane substantially perpendicular to a plane of the conveying direction.

[0069] As further shown in FIG. 1, the first beams 10 comprise an H-shaped cross-section. A lower part 103 of the H-shaped cross-section covers the rollers 111 thus reducing potential contamination of the rollers by e.g. coatings falling from the products when the conveyor unit is arranged e.g. Inside a furnace. Alternatively, the first beams may comprise an inverted U-shaped cross-section.

[0070] FIGS. 2a and 2b show cross-sectional views at different vertical positions of second beams of the unit of FIG. 1 arranged inside a furnace 30. In FIG. 2a the second beams are at the lower vertical position and in FIG. 2b the second beams 20 are at the upper vertical position. As further shown in these figures, a working surface 104. i.e. a surface of the first beams 10 on which a product 100 may be supported, lies between the upper vertical position and the lower vertical position.

[0071] The second beams 20 may be mounted in supports 201. In examples, T-shaped supports able to withstand two beams at the same time may be foreseen. The supports 201 may in turn be mounted to a frame 202 that may be connected to the further driving mechanism configured to provide the second beams 20 with the up-and-down reciprocating motion. In examples, the driving mechanism may be any known mechanical, hydraulical or servo-mechanical mechanism providing a linear displacement. Particularly hydraulic pistons driven by a motor, e.g. an electric motor, may be foreseen.

[0072] As further shown in FIGS. 2a and 2b the conveyor unit may be housed inside the furnace 30 leaving e.g. the driving mechanisms and the shafts 111 outside from the furnace 30. This way only the beams (first and second beams), the rollers and the supports for the second beams need to be made from e.g. refractory materials able to withstand high temperatures inside the furnace, when the conveyor unit is designed to be mounted inside a furnace. This is rather cost-effective in terms of material costs.

[0073] FIGS. 3a-3d schematically show a sequence of situations occurring during the performance of a method of moving products or batches of products such as e.g. blanks or parts in a conveying direction through a conveyor unit substantially as hereinbefore described. The method is described below with reference to the sequences of situations illustrated by FIGS. 3a-3d.

[0074] The sequence starts at FIG. 3a in which the first beams 10 are positioned in the upstream position 101 (the downstream position 102 of the first beams is represented in dashed lines) and the second beams 20 in the lower vertical position (see FIG. 2a). In these initial positions of the first and second beams, a product 100 (or alternatively a plurality of products, even a batch or products) may be provided on the first beams 10 at an initial position X1 along the conveying direction (arrow A) corresponding to an initial position Y1 along the first beams 10 (arrow B).

[0075] In FIG. 3b the first beams 10 with the product 100 are in the downstream position, i.e. the first beams have already been moved from the upstream position to the downstream position. This way, the product 100 may reach a first position X2 along the conveying direction (arrow A) while maintaining the initial position Y1 with respect to the first beams 10.

[0076] Further in FIG. 3b, the second beams 20 may be moved from the lower vertical position to the upper vertical position. The product 100 may thus be supported by the second beams 20, at the first position X2 along the conveying direction (arrow A).

[0077] The sequence continues in FIG. 3c in which the first beams 10 are again in the upstream position, i.e. the first beams have already been moved back from the downstream position to the upstream position. Further in FIG. 3c, the second beams 20 may have already been moved back from the upper vertical position to the lower vertical position. This way, the product 100 may again be supported by the first beams 10 at the first position X2 along the conveying direction (arrow A) that now corresponds to a first position Y2 along the first beams (arrow B). The first position Y2 along the first beams is different than the initial position Y1 along the first beams, the first position Y2 lying closer to a downstream end 105 of the first beams 10 than the initial position Y1.

[0078] At this stage, a further product (or products) 100 may be provided on the first beams 10 substantially upstream from the product 100 already in the first position Y2 along the first beams 10. The further product 100 may e.g. be provided at the initial position Y1 along the first beams 10 (arrow B) and the same sequence substantially as explained in connection with FIGS. 3a-3c may be repeated. In alternatives, the further product may be provided after two, three or more strokes (back-and-forth reciprocating motion) of the first beams. The products may be identical or different.

[0079] At FIG. 3d, the first beams 10 with the product 100 at the first position Y2 with respect to the first beams 10 and the further product 100 at the initial position Y1 with respect to the first beams 10 may have already been moved from the upstream position to the downstream position. This way, the product 100 may reach a second position X3 along the conveying direction (arrow A) while maintaining the first position Y2 with respect to the first beams (arrow 8). In those examples, in which a further product 100 is further provided at the initial position Y1 with respect to the first beams 10, the further product 100 may also be moved supported by the first beams 10 as the product 100 but from the initial position X1 along the conveying direction to e.g. the first position X2 along the conveying direction (arrow A) while maintaining the initial position Y1 along the first beams 10.

[0080] A sequence substantially as hereinbefore described may be repeated until the products (or batch of products) moves along the entire length of the first beams. This way, provided a further product is always provided after one or more strokes (back-and-forth reciprocating motion) of the first beams, a continuous (including semi-continuous) flow of heated products may be provided at an exit of the conveyor unit housed inside the furnace. In examples, the products may be left inside the furnace a predefined time in order to provide further heating to the products (batch of products). In these cases, a semi-continuous flow of heated products, i.e. a batch of products is provided.

[0081] In all examples, the stroke speed and/or the acceleration-deceleration of the movement of the first beams may be set in accordance with the size of the furnace, the thermal cycle to be performed, and the input requirements of the equipment fed by the furnace. Furthermore, control system which may typically be a combination of hardware and software may also be provided to regulate the speed at which the products move forward and/or the time the conveyor unit is stopped, e.g. in case a batch of products needs to stay inside the furnace longer.

[0082] In circumstances, depending on the relative length of the first and second beams, when a downstream end of the first beams is reached by a product, i.e. a last position along the conveying direction, a further step involving moving the second beams supporting the product from the upper vertical position to the lower vertical position such that the product remains supported by the second beams, at the last position along the conveying direction may be foreseen. In these cases, a still further step may involve moving the first beams from the upstream position to the downstream position so as to push the product supported by the second beams, from the last position along the conveying direction to an end position along the conveying direction. In these examples, such a pushing movement may be used e.g. for transferring of the products from e.g. the furnace to e.g. a press system. Alternatively, at the end position of the products a robot, e.g. a transportation fork or any other known holding unit may be provided for taking the heated products and moving them to the next process.

[0083] In examples, a holding unit, robot or fork may be provided at the beginning of the conveyor unit for providing the products in the initial position.

[0084] In order to provide a continuous flow of heated products (e.g. blanks), i.e. able to timely feed a continuous process such as e.g. a press system with the heated products, one or more conveyor units substantially as hereinbefore described may be provided inside the furnace. This way, the products may be moved inside the furnace by repeating a sequence substantially as explained in connection with FIGS. 3a-3d as necessary as a function of a length of the furnace which may depend, in turn, on the time the products need to be subjected to the temperature of the furnace.

[0085] FIGS. 4a and 4b schematically show a partial top view of two conveyor units consecutively arranged so as to build a larger conveyor system. In more examples, more conveyor units may be foreseen. Each conveyor unit may be made and performed substantially as explained in connection with FIGS. 1-3d.

[0086] In the example of FIGS. 4a and 4b an upstream conveyor unit 40 and a downstream conveyor unit 50 are shown. Each unit 40, 50 may comprise first horizontally moving beams 41, 51 and second vertically moving beams 42, 52 substantially as hereinbefore described. A downstream end 412, 422 of the first 41 and second 42 beams of the upstream unit 40 may respectively abut an upstream end 511, 521 of the first 51 and second 52 beams of the downstream unit 50.

[0087] In this example, the first beams 41, 51 may move in unison and the second beams 42, 52 may move in unison. In some examples, the horizontally moving beams of a first unit may be connected by means of any known mechanical, hydraulic, or electronic system with the horizontally moving beams of a second unit in order to ensure that the moving beams of different conveyor units move in unison.

[0088] As further shown in FIGS. 4a and 4b, a sequence describing how a product 100 may be moved/transferred from the upstream unit 40 to the downstream unit 50 is schematically described.

[0089] In FIG. 4a, a product 100 is already at a downstream end 412 of the first beams 41. The first beams 41, 51 of both units 40, 50 may e.g. be at the downstream position. Thus, the product 100 may be at a downstream end position Xe along the conveying direction (arrow A) of the first beams 41 of the upstream unit 40. In FIG. 4b, the following steps may have already been carried out in the mean time: the second beams 42, 52 may have been moved from the lower vertical position to the upper vertical position, the first beams 41, 51 may have been moved back from the downstream position to the upstream position and the second beams 42, 52 may have further been moved back from the upper vertical position to the lower vertical position. This way, the product 100 may now be supported on the first beams 51 of the downstream unit 50, at an upstream end 511 thereof corresponding to the initial position Y1 along the first beams 51 of the downstream unit 50 and while maintaining the Xe position along the conveying direction (arrow A).

[0090] In some of these examples, the second beams of consecutive conveyor units, e.g. second beams 42 and 52 of units 40 and 50 of FIGS. 4a and 4b may be supported by the same support (reference 201 of FIG. 1). This way, a downstream end 422 of the second beams 42 of an upstream conveyor unit 40 and an upstream end 521 of the second beams 52 of a downstream conveyor unit 50 may be supported by a support as that shown with reference 201 in FIG. 1. In some examples, the support may be a T-shaped support. The provision of a single support contributes to moving the second beams of consecutive conveyor units in unison.

[0091] In alternative examples, the first beams (moving horizontally) of consecutive conveyor units may be interleaved along a part of their length and move in unison.

[0092] In some processes, for example hot forming, continuous furnaces may have an overall length ranging from approximately 35 to approximately 50 meters. In these examples, the furnace may comprise a plurality of conveyor units having a length ranging from approximately 5 to 10 meters. Thus, continuous furnace s may, in general be made from e.g. four to ten conveyor units consecutively arranged so as to build a larger conveyor system substantially as hereinbefore described. Other number of units consecutively arranged may also be foreseen.

[0093] In all examples, the products may be made of aluminium or steel, particularly an Ultra High Strength Steel (UHSS).

[0094] Although only a number of examples have been disclosed herein, other alternatives, modifications, uses and/or equivalents thereof are possible. Furthermore, all possible combinations of the described examples are also covered. Thus, the scope of the present disclosure should not be limited by particular examples, but should be determined only by a fair reading of the claims that follow.