WO2007061310A1

WO2007061310A1 - Container

Info

Publication number: WO2007061310A1
Application number: PCT/NO2006/000393
Authority: WO
Inventors: Terje Yttersian; Torstein Yttersian
Original assignee: Terje Yttersian; Torstein Yttersian
Priority date: 2005-11-25
Filing date: 2006-11-01
Publication date: 2007-05-31
Also published as: NO326422B1; NO20055587D0; NO20055587L; CA2629755A1; EP1951601A1

Abstract

Container (1 , 101) , to contain a product, with at least one supply lid (31 , 32, 33/131 , 132, 133), arranged in an upper part (3, 103) and at least one discharge lid (21/121 , 122, 123), arranged in a lower part (2, 102), four walls (4, 5/104, 105). One of the transversal sidewalls (5, 105) is divided into two doors. The lower part (2, 102) has a vertically and horizontally extending sloping floor (11 , 111) , both in the transversal and the longitudinal direction. The container includes locking systems, preferably a 'Twist-lock' system. The inner sloping floor (11 , 111) of the lower part (2, 102) forms a funnel or several funnels to the discharge lid(s) (21 , 121 , 122, 123), to guide the product to the discharge lid(s) (21/121 , 122, 123). The supply and discharge lids (31 , 32, 33, 131 , 132, 133/21 , 121 , 122, 123) are centred in the transversal direction, in relation to the upper part (3, 103), respectively the lower part (2, 102). The container includes in addition discharge systems, such that it is self-discharging.

Description

Container

The present invention relates to a container which is designed for storing, transporting and distribution of products, according to the preamble of claim 1. In addition the invention includes discharge systems for discharging and emptying the container.

Background

In the aquaculture industry for example, it is desirable to have a container which provides for a robust and profitable transport. In addition these containers should be easy to store and empty, preferably be self-discharging. The containers should in addition be transportable both at sea, on a vessel, and on shore, by a vehicle. In addition, it is, in this connection desirable that there are as few operations as possible, to avoid, damage to for example feed. With present packaging, parts of the feed are crushed and transformed to dust. An example of such a packaging is large bags. Today requirements are set for, e.g. that a container with feed should not be opened before it is in the hands of the consumer, and in that connection it is desirable that a container can be sealed and not opened before its content should be used.

In addition it is desirable that a container has international measurements, so that it can be transported by the existing transport means.

Today's existing solutions often result in the product having to be moved from the packaging/container it is transported in, over to another application which is suitable for distributing the product. Feed is today transported in large bags, and the feed is thus exposed to large exterior strain, which results in the feed being crushed. In the cases where the feed is transported in silos on vessels, the feed at the bottom of the silo is also crushed, and in addition it is exposed to several handlings before it ends up at the consumer. This is often the case in for example the aquaculture industry, where you get feed in the above mention manner, and the feed must subsequently be transferred to another application, where the feed is distributed in desirable amounts. The feed will then not have the right qualities and can then maybe not be used, e.g. as fish meal.

US 2 931 523 (T. P. Nelligan) shows a compartment with discharge outlets in the bottom and inflatable bags to provide angles which results in the compartment being emptied through the discharge outlets without tilting of the compartment.

Another example of such a solution is US 3 139 998 (N. R. Seaman) which is a compartment with a similar system as US 2 931 523, where bags are inflated to guide the product to an outlet, without the compartment being tilted.

US 3 756 469 (Edwin E. Clark et al.) shows a carrier unit which includes a container which can be used as an ordinary container with flat floor, or the container can be transformed to self-discharging by means of plates in the floor which can be opened such that the container can be emptied by a discharge system, which is arranged below the floor of the container.

SE 7811690 (P. H. Martin et a/.) shows a telescopic truck body which is changeable in the longitudinally direction, with a bulkhead and an outlet at the rear end, via which the container can be emptied.

EP 1 262 610 (Basi, Beat) shows a container, attached to a trailer, which can be emptied via a rear end discharge outlet, by means of a hydraulic cylinder tilting the container.

None of the above mentioned solutions solves the problem with a container which can be transported by international transport means, and which in addition to being used to transport a product, also can be used to form a silo and to distribute and empty the product in a suitable manner.

Object

The main object of the invention is thus to provide a container which provides a secure, robust and profitable way to transport, store and distribute a product in a rational manner.

Another object of the invention is to provide a container which further can be used to provide a store system, which has a relatively large storage capacity per m².

It is also an object with the invention to provide an advantageous discharge system for the container.

The invention

The invention is described in claim 1. With such a container it is possible to achieve all the objects mentioned above.

In claims 2-20, special advantageous details of the invention are described. Further advantageous features will appear from the following example description.

The container is designed for storing, transporting and distribution of any kind of feed for the fishing industry, farming and other industries. The container can be used for storing and transporting of almost any kind of product, presupposing that the shape and the size of the product makes this favourable. Preferably, this is a 20 foot container with the capacity of up to 20 tons feed (dependent of the size of the pellets etc.), but also other sizes can be used, e.g. 10 or 30 foot containers.

The design of the container is of such a kind that it can easily be stored one on top of each other, and that the containers located above other containers can be emptied through the underlying containers. This is possible due to the interior of the container and the arrangement of supply and discharge lids. By arranging several containers one above each other this results in a relatively large storage capacity per m².

The containers can be constructed with different numbers of supply and discharge lids, depending on the interior and the object. The lids can be hinged or of a throttle-type which are pushed by means of hydraulic or pneumatic cylinders. They can also be opened/closed by screws, chain transmission, rope drive or by hand - according to requirements.

The container preferably has international measurements, something which will make it suitable for transport by existing transport means at sea and onshore.

It can be used as a link in a supply chain, based on the exchange of containers, or it can also be used in existing logistics chains.

The container can be used together with existing feed automats, or it can be used as feed automats together with a discharge device.

The container can be constructed to fit to/arranged with different discharge systems according to desire and the use object, such as

- Tilting fundament

- Discharge devices with feed screw

- Discharge devices equipped for water, blow or vacuum transport

- Fundament with gutter and discharge pipe

Example

The invention will in the following be described by means of different embodiments, with reference to the attached drawings, where:

Figure 1a is a cross sectional view, seen from the longitudinal side, of a first embodiment of a container,

Figure 1 b is a cross sectional view, seen from the transversal side, of a first embodiment of a container,

Figure 2 shows a tilting platform for a container,

Figure 3a shows a container arranged on a tilting platform, seen from the longitudinal side, in resting position,

Figure 3b shows a container arranged on a tilting platform, seen from the longitudinal side, in discharge position,

Figure 4 shows three containers arranged one above the other, on a tilting platform, in resting position, to form a store and a discharge system,

Figure 5a is a cross sectional view, seen from the longitudinal side, of a second embodiment of a container, Figure 5b is a cross sectional view, seen from the transversal side, of a second embodiment of a container,

Figure 6 is a cross sectional view, seen from the longitudinal side, of a third embodiment of a container,

Figure 7 shows three containers arranged one above the other, on a discharge device, to form a store and a discharge system,

Figure 8a shows a first embodiment of a discharge device,

Figure 8b shows a second embodiment of a discharge device,

Figure 8c shows a third embodiment of a discharge device, and

Figure 8d shows a fourth embodiment of a discharge device,

Figure 1a and 1b shows a cross section of a container 1 , seen from the longitudinal side and the transversal side, respectively, of a first embodiment of the invention. The container 1 preferably has a rectangular exterior shape. The container 1 includes in the illustrated example a lower part 2, an upper part 3, two longitudinal sidewalls 4 and two transversal sidewalls 5, which together form the container 1 with an inner space 10. One of the container's transversal sidewalls 5 is preferably divided into two doors (not shown), which opens for access to the inner space 10 of the container.

The upper part 3 of the container 1, in the example, includes three supply lids 31, 32 and 33. The supply lids 31 , 32 and 33 are distributed so that the best ratio of fullness is achieved, but preferably two of the lids 31 and 33 are arranged at each side of the upper part 3, while the lid 32 preferably is arranged at the centre of the upper part.

The lower part 2 of the container includes a discharge lid 21 , preferably arranged close to the end of the lower part 2, which faces the transversal sidewall 5 which is arranged opposite to the transversal sidewall 5 with doors.

The discharge lid 21 is preferably smaller than the supply lids 31, 32 and 33, to prevent the product from flowing out at the top of container(s) arranged below, upon emptying of containers arranged as a store, as described below.

The supply and discharge lids 31, 32, 33 and 21 are centred in the transversal direction and preferably have a rectangular shape, but these can also be of any shape. For example, the supply lids 31 , 32 and 33 have a size of 900 x 700 mm and the discharge lid 21 has a size of 600 x 450 mm.

The lids are preferably sliding lids which can be opened and closed by means of suitable means, e.g. hydraulic or pneumatic cylinders (not shown).

In the inner space 10 of the container is arranged an inner sloping floor 11, which slopes both in the transversal direction 12 and the longitudinal direction13 and which together form a funnel to the discharge lid 21. The bevel angle θ\ in the longitudinal direction is preferably larger that 10°, and the bevel angle β in the transversal direction is preferably larger than 20°.

In addition there is a sloping surface 14 from the transversal sidewall 5 to the discharge lid 21 and which has an angle α₂. The angle α₂ is preferably larger than 20°.

The bevel angles will be dependent on the type of product for which the container is to be used.

The distance the sloping floor extends upwards from the longitudinal part of the sloping floor 12, will depend of the length of the container and the angle αi and α₂, respectively, while the distance the sloping floor extends upwards in the transversal direction will depend of the width of the container and the angle β.

The sloping floor 11 can either be shaped as a fixed sloping, as shown in this example, or it can be arranged as a movable floor which can be lifted by means of pneumatic or hydraulic cylinders (not shown). It is also possible to make the sloping floor movable by providing it with spring or string rope drive (not shown), which lifts it at the rear edge as the containers content is emptied, and the weight of the content becomes under a certain weight.

The sloping floor 11 can also function as a slam tank if desired.

To achieve maximum ratio of fullness it is advantageous that the angles αi, α₂ and β are as small as possible, but that they still are so large that the product can be delivered out of the container.

To achieve that complete emptying of the container 1 , it is advantageous to have a tilting fundament 40 which, together with the sloping floor 11 , meets the requirement for necessary inclining to be able to empty the container 1 completely. This is achieved by an angle θ, see Figure 3a and Figure 3b. The angle θ is preferably larger than 10°, but smaller than 30°.

The tilting fundament 40 consist of a frame 41, as shown in Figure 2, which has a rectangular part 42 and a thereto arranged right-angled triangular part 43, where the right- angled side of the triangle is arranged in the same plane as the baseline of the frame 41 , and thus the baseline of the rectangular part 42.

The tilting fundament 40, in addition, has supporting elements 44 arranged at advantageous positions in the frame 41 , to make it more solid.

In addition there is provided a tilting frame 45 (Figure 3a and 3b), which is rotatably arranged in point 46, which preferably is as close to the y-axis of the centre of gravity as possible, but at the same time so that the tilting frame 45 and the container 1 , stay in a horizontal position when no force is exerted on the container 1 or the tilting frame 45. The container 1 is fixed to the tilting fundament 40, via the tilting frame 45, by means of a "twist lock" system. The "twist lock" system is a well known and secure system which to a large extent is used for containers.

The tilting fundament 40 is so constructed that relatively small forces are needed to tilt the container 1 to a desired position, which is an angle θ. The fundament 40 must thus be affected by an external force to tilt. This can, for example, be done by two hydraulic cylinders (not shown), which are arranged at the farthest end and which perform the actual tilting. The running of the means for opening and closing lids, raising and lowering the floor, and to tilt the tilting fundament is performed by means of external means (not shown).

Figure 4 shows an arrangement with three containers 70, 71 and 72, arranged one above the other to form a store (or a silo) 80. The containers 70, 71 and 72 separately correspond to the container 1. in addition the arrangement includes the tilting fundament 40. The containers 70, 71 and 72 are fixed to each other in the same way as the container 1 is fixed to the tilting frame 45 of the tilting fundament 40, which is by means of a "twist lock" system.

With this arrangement the store 80 can be emptied through the bottom container 70 and via the discharge lid 74. The containers 71 and 72 can be emptied by opening the supply lid 75 of the container below, and subsequently open the discharge lid 74 in the container which is to be emptied. To empty the containers 70, 71 and 72 completely, the containers are tilted the angle θ by means of the tilting fundament 40.

In Figure 5a and 5b there is shown a second embodiment of a container. The Figures show a cross section of a container 101, seen from the longitudinal side and the transversal side, respectively.

This embodiment will provide the best possible ratio of fullness, combined with the container 101 being self-discharging.

The container 101 preferably has a rectangular exterior shape. The container 101 includes in this example a lower part 102, an upper part 103 and two longitudinal sidewalls 104 and two transversal sidewalls 105, which together forms the container 101 with an inner space 110, corresponding to the container 1. One transversal sidewall 105 of the container 101 is preferably divided into two doors (not shown), so that it opens for access to the inner space 110 of the container.

The upper part 103 of the container 101 includes, in the example, three supply lids 131, 132 and 133. The supply lids 131 , 132 and 133 are distributed so that the best ratio of fullness is achieved, but preferably two of the lids 131 and 133 are arranged at each side of the upper part 103, while the lid 132 is preferably arranged at the centre of the upper part 103. The lower part 102 of the container 101 includes three discharge lids 121, 122 and 123, where preferably two of the lids 121 , 123 are arranged close to each end of the lower part 102 of the container 101. The discharge lid 121 and the supply lid 131 , the discharge lid 122 and the supply lid 132, and the discharge lid 123 and the supply lid 133, respectively, are arranged so that they are centred with each other, and in addition all the lids are preferably centred in the transversal direction of the upper part 103.

The supply and discharge lids 131 , 132, 133/121, 122, 123 preferably have a rectangular shape, but can be of any other shape. The lids are preferably sliding lids which can be opened and closed by means of suitable means, e.g. hydraulic or pneumatic cylinders (not shown), which are run by external means (not shown). For example, the supply lids 131 , 132 and 133 have a size of 900 x 700 mm and the discharge lids 121, 122 and 123 a size of 600 x 450 mm.

In the inner space 110 of the container 101 there is arranged an inner sloping floor 111 , which slopes both in the transversal direction 112 and the longitudinal direction 113 and 114. The sloping in the longitudinal direction 113 and 114 is such that it inclines from the discharge lid 121 , 122 and 123 at an angle δ-i relative to points 134 and 135 respectively. The points 134 and 135 are located in the middle of the lids 121 and 122, respectively 122 and 123, and some distance up from the lower part 102, in the vertical direction from the lower part 102. The distance to the points 134 and 135 will depend on the length of the container 101 and the angle δ-i and the positions of the discharge lids 121, 122 and 123 in relation to each other, and the lower part 102. The angle β in the transversal direction is preferably larger than 20°. In addition the lower part 102 includes a sloping 115 from the transversal sidewalls 104 to the discharge lids 121 and 123 and is at an angle δ₂. The angle δ₂ is preferably larger than 20°. Together the sloping angles forms three funnels which guide a product situated in the container 101, out against the three discharge lids 121, 122 and 123.

Figure 6 shows another embodiment of a container. The same reference numbers are used for similar features as for the container 101. Here the container 201 only includes two discharge lids 121 and 123. The discharge lids 121 and 123 are preferably arranged at each end of the lower part 102. The supply and discharge lids are arranged in the same way as for the container 101. The inner sloping floor 211 includes only one longitudinal sloping floor 213 which extends between the lids 121 and 123, in the same way as for container 101 , i.e. the sloping floor 213 has an angle δ₃ from each of the discharge lids 121 , 123, which extends to a point 234, which then will be located in the middle of the lower part 102, at a distance vertically from the lower part 102. This distance will be dependent on the length of the container 201 and the position of the discharge lids 121 and 123. The angle δ₃ is preferably larger than 20°. The rest of the features are the same as for the container 101 and are thus not further described.

Figure 7 shows an arrangement for an advantageous store with a discharge system. The store is, in the example, formed by three containers 101 , arranged one above the other. To achieve an advantageous distribution of the described container 101, a discharge device 140 (Figure 8a and 8b) with feed screw(s) 146 can be arranged under the container 101. This is especially advantageous, for e.g. distribution of feed in relation to the aquacultύre industry and agriculture, where the container 101 with the device 140 can transport the feed from a store/silo container out to the consumer. This opens up for an advantageous distribution system, where the empty container 101 can be exchanged with a full one.

The discharge device 140 is fixed to the container 101 by means of the same "Twist lock" system as is used for fixing containers, which is a well known and used system.

The discharge device 140 can also be equipped with equipment for vacuum, blow or water transport (not shown).

The discharge device 140 can for example have a design which provides longitudinal product transport, as shown in Figure 8a and 8b, or transversal product transport, as shown in Figure 8c and 8d.

For a container 101 it is most advantageous to use a discharge device 140, as shown in Figure 8a and 8b, but for a container 201 it is most advantageous to use a discharge device 140, as shown in Figure 8a-8d, whatever fits best for the user.

The discharge device 140 preferably has a rectangular shape which accommodates the lower part of a container 101. The discharge device 140 is formed by a frame 141 which is formed by a lower part 142, two longitudinal sides 143 and two transversal sides 144. It has in addition, at least one output 145 for distribution of the product. The frame 141, in addition, includes supporting and reinforcing elements 148, arranged at advantageous positions.

The lower part 142 of the discharge device 140 is inclined, so that it inclines from the middle and down to the outputs 145 and the feed screw(s) 146 (Figure 8a and 8c), or from the longitudinal sidewalls 143, or the transversal sidewalls 144, and down to the output 145 and the feed screw(s) 146 (Figure 8b and 8d). The object of the sloping floor is to guide the product towards the feed screw(s) 146. The feed screw(s) 146 extend either between the two longitudinal sides 143, or the two transversal sides 144, to the outputs 145. The feed screw(s) are of standard design and standard support in the two longitudinal sides 143, respectively the transversal sides 144. The feed screw(s) 146 are run by suitable external means (not shown). The outputs 145 for a discharge device 140, which makes use of a longitudinal product transport, are positioned against the edges of one of the transversal sides 144 (Figure 8a), or in the middle of the transversal side 144 (Figure 8b). For a solution which has transversal product transport, the outputs 145 are arranged at one of the longitudinal sides 143, either at the ends (Figure 8c) of the longitudinal side 143, or in the middle of the longitudinal side 143 (Figure 8d). The outputs 145 have a flange 147, extending vertically out from the longitudinal sides 143, respectively the transversal sides 144, which are accommodated for connection of external equipment (not shown). The bevel angle of the floor is preferably larger than 20°.

Emptying of the containers 101 or 201, which are arranged on top of other containers, is achieved in the following way;

The supply lid(s) 131, 132 and 133 of the container(s) 101/201, which are arranged at the bottom are opened and subsequently the discharge lid(s) 121, 123 (and 123) in the container which is to be emptied are opened. Since the discharge lids 121, 122 and 123 are no smaller than the supply lids 131, 132 and 133, the result is that the product does not flow out at the top of the container(s) located below. The sloping floor 111 of the container 101/201 , results in the container 101/201 being emptied completely.

Modifications

The container can have different numbers of supply and discharge lids, but must at least have one of each.

The lower part of the container is accommodated to the number of supply lids, so that the floor inclines down to the individual discharge lids.

The lids can be of different types, such as damper lids, sliding lids or hinged lids, and can have different shape and size, but are preferably rectangular.

The controlling of the opening and closing of the lids can be effected in different ways, such as by means of pneumatic or hydraulic cylinders, or other suitable methods.

The lids do not need to be of the same type, even though this will be favourable, as the containers which are arranged one above the other do not use all the lids.

The container can have any shape and size, but is preferably rectangular, so as to accommodate international transport means.

Containers arranged one above the other to form a store, can have different numbers of supply and discharge lids, but the lowest container has preferably the same number of supply lids as the number of discharge lids of the container arranged above.

Also a container not having an upper part can be made, for example has a tarpaulin covering the upper part, but has a lower part as herein described, which can be connected to the discharge system as herein described. Several such containers can on the other hand not be used to form a store, but can be free-standing and have other areas of use in addition to those herein described. Containers which are arranged one above the other to form a store are fixed to each other by means of locking systems, which can be of different types, but the system is preferably a "Twist-lock" system.

Claims

1. Container (1, 101), to contain a product, with at least one supply lid (31, 32, 33/131 , 132, 133), arranged in an upper part (3, 103), and at least one discbarge lid (21/121 , 122, 123) arranged in a lower part (2, 102), four walls (4, 5/104, 105), wherein one of the transversal sidewalls (5, 105) is divided into two doors, where the lower part (2, 102) has a vertically and horizontally extending sloping floor (11, 111), both in the transversal and the longitudinal direction, where the container includes locking systems, preferably a "Twist- lock" system, characterized in

- that the inner sloping floor (11 , 111) of the lower part (2, 102) forms a funnel or several funnels to the discharge lid(s) (21/121, 122, 123) to guide the product to the discharge lid(s) (21/121, 122, 123),

- that the supply and discharge lids (31, 32, 33, 131, 132, 133/21, 121, 122, 123) are centred in the transversal direction in relation to the upper part (3, 103), respectively the lower part (2, 102), and

- that the container includes discharge systems.

2. Container according to claim 1 , characterized in that the supply and discharge lids (31 , 32, 33, 131 , 132, 133/21 , 121 , 122, 123) preferably have a rectangular shape, and that they are preferably sliding lids, which are opened and closed by means of suitable means, preferably hydraulic or pneumatic cylinders.

3. Container according to claim 1 , characterized in that the sloping floor (11) has a bevel angle α-i, α₂ in the longitudinal direction, and a bevel angle β in the transversal direction.

4. Container according to claim 1, characterized in that the sloping floor (111) has a beve) angle δi, δ₂ in the longitudinal direction, and a bevel angle β in the transversal direction.

5. Container according to claim 1 , characterized in that the discharge system is a tilting fundament (40).

6. Container according to claim 5, characterized in that the tilting fundament (40) is formed by a frame (41) and a tilting frame (45), which is rotatably supported in the projecting point (46) of the frame (41).

7. Container according to claims 5 and 6, characterized in that the frame (41) includes a preferably rectangular part (42) and arranged thereto a right-angled triangular part (43), where the right-angled side of the triangle is arranged in the same plane as the baseline of the frame (41), and consequently the baseline of the rectangular part (42), and that it has supporting elements (44) arranged in advantageous positions.

8. Container according to claims 5-7, characterized in that the point (46) is arranged as close to the y-axis of the centre of gravity as possible.

9. Container according to claims 5-8, characterized in that the tilting fundament (40) can tilt the container (1), preferably an angle θ°.

10. Container according to claims 1-9, characterized in that the container (1) is fixed to the tilting fundament (40) via the tilting frame (45) by means of a lock system, preferably a "Twist-lock" system.

11. Container according to claim 1 , characterized in that the discharge system is a discharge device (140).

12. Container according to claim 11 , characterized in that the discharge device (140) includes a frame (141), with a lower part (142), two longitudinal sides (143), and two transversal sides (144), at least one output (145), at least one feed screw (146) and reinforcing elements (148).

13. Container according to claims 11 and 12, characterized in that the feed screw(s) (146) is/are arranged vertically between the two longitudinal sides (143) of the frame (141), parallel to, and close to the transversal sides (144), or centred between the longitudinal sides (143).

14. Container according to claims 11 and 12, characterized in that the feed screw(s) (146) is/are arranged horizontally between the two transversal sides (144) of the frame (141), parallel to, and close to the transversal sides (143), or centred between the transversal sides (144).

15. Container according to claims 11, 12 and 13,| characterized in that the output/outputs (145) is/are arranged in one of the longitudinal sides (143), close to the transversal sides (144), or centred at the longitudinal side (143), with the same centre as the feed screws (146).

16. Container according to claims 11 , 12 and 14, characterized in that the output/outputs

(145) is/are arranged in one of the transversal sides (144), close to the longitudinal sides (143), or centred at the transversal side (144), with the same centre as the feed screws (146).

17. Container according to claims 11-16, characterized in that the outputs (145) have a projecting flange (147), which is adapted for connection of external equipment.

18. Container according to claims 11-17, characterized in that the lower part (142) of the discharge device (140) is arranged sloping, from the middle of the discharge device (140) and down to the feed screw(s) (146) and the outputs (145), either in the longitudinal direction, or in the transversal direction.

19. Container according to claims 11-17, characterized in that the lower part (142) of the discharge device (140) is arranged sloping, from the longitudinal sides (143) or the transversal sides (144) of the discharge device (140), and down against the feed screw(s)

(146) and the outputs (145), either in the longitudinal direction or in the transversal direction.

20. Container according to the previous claims, characterized in that containers (1 , 101) can be arranged one above the other, and preferably above a discharge system (40, 140) to form a store and distribution system.

21. Container according to claim 20, characterized in that the containers are fixed to each other by means of a lock system, preferably a "Twist-lock" system.