EP4033030A1

EP4033030A1 - Scraping device with lateral wings

Info

Publication number: EP4033030A1
Application number: EP22151723.8A
Authority: EP
Inventors: Jens BÄCKSTRÖM OLOFSSON
Original assignee: Drivex AB
Current assignee: Drivex AB
Priority date: 2021-01-26
Filing date: 2022-01-17
Publication date: 2022-07-27
Anticipated expiration: 2042-01-17
Also published as: SE2150083A1; SE544607C2; EP4033030B1; FI4033030T3

Abstract

A scraping device mountable to a vehicle and comprising a central base part and two lateral wings arranged on opposite sides of the base part and mounted to a respective support frame that is hinged to the base part, wherein each lateral wing (10a) is, by a main hydraulic cylinder (30a), pivotable in relation to the base part about a pivot axis together with the associated support frame (20a) between a swung-in non-operative position and a swung-out operative position. Each lateral wing is slidable upwards and downwards in relation to the associated support frame between a lowermost position and an uppermost position in directions parallel to the pivot axis. Each lateral wing is, by a lifting mechanism and an auxiliary hydraulic cylinder that are mounted to the support frame of the lateral wing, liftable upwards in relation to the support frame from its lowermost position to a raised resting position.

Description

FIELD OF THE INVENTION AND PRIOR ART

The present invention relates to a scraping device according to the preamble of claim 1 for removal of snow, ice or other material from a surface, such as a road surface or ground surface.
A scraping device designed to be mounted to a vehicle is previously known from SE 525 295 C2 . This scraping device comprises a central base part in the form of a bucket and two pivotable lateral wings arranged on opposite sides of the base part, wherein the lateral wings are pivotable in relation to the base part by means of hydraulic cylinders between a swung-in non-operative position close to the side walls of the base part and a swung-out operative position. When the scraping device is used for scraping of snow or ice on a road surface or the ground, the lateral wings may be arranged in the swung-out operative position in order to maximize the width of the scraping device and thereby increase the efficiency of the scraping device. When the lateral wings are arranged in the swung-in non-operative position, the scraping device may be used as a conventional bucket. The lateral wings may also be arranged in the swung-in non-operative position when the scraping device is used for scraping of snow or ice on a narrow surface or when the scraping device is being transported or stored. In the scraping device disclosed in SE 525 295 C2 , the lateral wings are carried by a respective support frame, which in its turn is pivotally mounted to the base part, wherein each lateral wing is slidably mounted to the associated support frame in order to allow the lateral wing to move upwards and downwards in relation to the support frame. The base part and a lateral wing may hereby operate on mutually different levels as seen in vertical direction, for instance with the base part in scraping contact with a road surface and with a lateral wing in scraping contact with an adjacent and elevated sidewalk.

OBJECT OF THE INVENTION

The object of the present invention is to provide a scraping device of the above-mentioned type that has a new and favourable design.

SUMMARY OF THE INVENTION

According to the present invention, said object is achieved by means of a scraping device having the features defined in claim 1.
The scraping device according to the invention comprises:

attachment means, by means of which the scraping device is mountable to a vehicle;
a central base part provided with a lower scraping edge, wherein the base part is connected to the attachment means in order to allow the base part to be carried by the vehicle via the attachment means;
first and second lateral wings arranged on opposite sides of the base part, wherein each one of the first and second lateral wings is provided with a lower scraping edge;
a first support frame, wherein the first lateral wing is mounted to the first support frame and wherein the first support frame is hinged to the base part and pivotable in relation to the base part about a first pivot axis to thereby allow the first lateral wing to be pivoted in relation to the base part together with the first support frame about the first pivot axis between a swung-in non-operative position and a swung-out operative position, the first lateral wing being slidably mounted to the first support frame in order to allow the first lateral wing to move upwards and downwards in relation to the first support frame between a lowermost position and an uppermost position in directions parallel to the first pivot axis;
a second support frame, wherein the second lateral wing is mounted to the second support frame and wherein the second support frame is hinged to the base part and pivotable in relation to the base part about a second pivot axis to thereby allow the second lateral wing to be pivoted in relation to the base part together with the second support frame about the second pivot axis between a swung-in non-operative position and a swung-out operative position, the second lateral wing being slidably mounted to the second support frame in order to allow the second lateral wing to move upwards and downwards in relation to the second support frame between a lowermost position and an uppermost position in directions parallel to the second pivot axis;
a first main hydraulic cylinder for pivoting the first support frame in relation to the base part about the first pivot axis;
a second main hydraulic cylinder for pivoting the second support frame in relation to the base part about the second pivot axis;
a first lifting mechanism, which is mounted to the first support frame and capable of lifting the first lateral wing upwards in relation to the first support frame from its lowermost position to a raised resting position;
a second lifting mechanism, which is mounted to the second support frame and capable of lifting the second lateral wing upwards in relation to the second support frame from its lowermost position to a raised resting position;
a first auxiliary hydraulic cylinder connected to the first lifting mechanism, wherein the first lifting mechanism is actuatable by the first auxiliary hydraulic cylinder to lift the first lateral wing upwards in relation to the first support frame from its lowermost position to its raised resting position; and
a second auxiliary hydraulic cylinder connected to the second lifting mechanism, wherein the second lifting mechanism is actuatable by the second auxiliary hydraulic cylinder to lift the second lateral wing upwards in relation to the second support frame from its lowermost position to its raised resting position.

By means of the lifting mechanisms and the auxiliary hydraulic cylinders, the lateral wings can be lifted upwards in relation to their support frames, and thereby in relation to the central base part, when they are in the swung-in non-operative position. It is hereby possible to prevent the lower scraping edges on the lateral wings from contacting the ground and being subjected to wear when the scraping device is used for performing a scraping or loading operation with the lateral wings in the swung-in non-operative position.
According to an embodiment of the invention:

the first lifting mechanism comprises two levers, here denominated first and second levers, which are pivotally mounted to the first support frame, wherein each one of the first and second levers is pivotable in relation to the first support frame by the first auxiliary hydraulic cylinder from a lowered inactive position to a raised lifting position in order to push the first lateral wing upwards in relation to the first support frame from its lowermost position to its raised resting position; and
the second lifting mechanism comprises two levers, here denominated third and fourth levers, which are pivotally mounted to the second support frame, wherein each one of the third and fourth levers is pivotable in relation to the second support frame by the second auxiliary hydraulic cylinder from a lowered inactive position to a raised lifting position in order to push the second lateral wing upwards in relation to the second support frame from its lowermost position to its raised resting position.

By using such levers, each lifting mechanism may be kept completely separated from the associated lateral wing when the lateral wing is in its swung-out operative position and brought into contact with the lateral wing only when the lateral wing is to be lifted upwards in relation to its support frame under the effect of the lifting mechanism and the associated auxiliary hydraulic cylinder. The lifting mechanism is thereby prevented from interfering with the mutual movements between the lateral wing and the support frame that occur during a scraping operation with the lateral wing in a swung-out operative position.
Further advantageous features of the scraping device according to the present invention will appear from the dependent claims and the description following below.

BRIEF DESCRIPTION OF THE DRAWINGS

With reference to the appended drawings, a specific description of preferred embodiments of the invention cited as examples follows below. In the drawings:

Fig 1: is a perspective view of a scraping device according to an embodiment of the present invention, as seen with the lateral wings in a swung-out operative position,
Fig 2: is a perspective view of the scraping device of Fig 1, as seen from another direction,
Fig 3a: is a planar view from above of the scraping device of Figs 1 and 2, as seen with the lateral wings in a swung-out operative position,
Fig 3b: is a planar view from above of the scraping device of Figs 1 and 2, as seen with the lateral wings in a swung-in non-operative position,
Fig 4a: is a rear view of a first lateral wing and a first support frame included in the scraping device of Figs 1 and 2, as seen with the lateral wing in a lowermost position in relation to the support frame,
Fig 4b: is a rear view of the lateral wing and support frame of Fig 4a, as seen with the lateral wing in a raised resting position,
Fig 5a: is a rear view of a second lateral wing and a second support frame included in the scraping device of Figs 1 and 2, as seen with the lateral wing in a lowermost position in relation to the support frame,
Fig 5b: is a rear view of the lateral wing and support frame of Fig 5a, as seen with the lateral wing in a raised resting position,
Figs 6a and 6b: are rear views of the lateral wing and support frame of Fig 4a, as seen with the lateral wing in different positions in relation to the support frame,
Fig 7: is a perspective view from the front of the lateral wing and support frame of Fig 4a, as seen with the lateral wing separated from the support frame,
Fig 8: is a perspective view from the rear of the lateral wing and support frame of Fig 4a, as seen with the lateral wing separated from the support frame, and
Fig 9: is an outline diagram of hydraulic cylinders and an associated hydraulic system included in the scraping device of Figs 1 and 2.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

A scraping device 1 according to an embodiment of the present invention is illustrated in Figs 1-3. The scraping device 1 is to be mounted to a vehicle, for instance in the form of a front end loader, and is intended to be used for removal of snow, ice or other material from a surface, such as a road surface, a sidewalk or the ground. The scraping device 1 comprises attachment means 2, by means of which the scraping device is detachably mountable to the vehicle. In the illustrated embodiment, the attachment means 2 comprise two hooks 3, by means of which the scraping device 1 may be mounted to the lifting arms of a front end loader.
The scraping device 1 comprises a central base part 5, which is provided with a lower scraping edge 6 that is to be applied against a surface to be subjected to scraping. The attachment means 2 are fixed to the base part 5 in order to allow the base part 5 to be carried by the vehicle via the attachment means 2. In the illustrated embodiment, the base part 5 has the form of a bucket with a bottom wall 7, a rear wall 8 and two opposite side walls 9a, 9b, which together define a cavity capable of receiving snow, ice, sand or any other bulk material. In this case, the scraping edge 6 is provided at the front end of the bottom wall 7. As an alternative, the base part of the scraping device 1 could have the form of a plough without any cavity for receiving material.
The scraping device 1 further comprises first and second lateral wings 10a, 10b arranged on opposite sides of the base part 5. Each lateral wing 10a, 10b is provided with a lower scraping edge 11 that is to be applied against a surface to be subjected to scraping. In the illustrated embodiment, the scraping edge 11 is formed by a longitudinal edge on a plough blade 12 or grader blade that constitutes a detachable part of the associated lateral wing 10a, 10b.
The first lateral wing 10a is mounted to a first support frame 20a, which is hinged to the base part 5 and pivotable in relation to the base part 5 about an essentially vertical first pivot axis A1. The first lateral wing 10a is pivotable in relation to the base part 5 together with the first support frame 20a about the first pivot axis A1 between a swung-in non-operative position (see Fig 3b) and a swung-out operative position (see Figs 1, 2 and 3a). The second lateral wing 10b is mounted to a second support frame 20b, which is hinged to the base part 5 and pivotable in relation to the base part 5 about an essentially vertical second pivot axis A2, which is parallel to the first pivot axis A1. The second lateral wing 10b is pivotable in relation to the base part 5 together with the second support frame 20b about the second pivot axis A2 between a swung-in non-operative position and a swung-out operative position. The first and second support frames 20a, 20b are hinged to the base part 5 on opposite sides thereof. In the swung-in non-operative position, the lateral wings 10a, 10b and the support frames 20a, 20b are located close to the side walls 9a, 9b of the base part 5. In the swung-out operative position, the lateral wings 10a, 10b and the support frames 20a, 20b are inclined outwards from the base part 5 in opposite directions at an angle that may be adjusted as desired by the driver of the vehicle.
A double-acting hydraulic cylinder 30a, in the following referred to as first main hydraulic cylinder, is arranged between the base part 5 and the first support frame 20a, wherein the first support frame 20a, and thereby the first lateral wing 10a, is pivotable in relation to the base part 5 about the first pivot axis A1 under the effect of this first main hydraulic cylinder 30a. Another double-acting hydraulic cylinder 30b, in the following referred to as second main hydraulic cylinder, is arranged between the base part 5 and the second support frame 20b, wherein the second support frame 20b, and thereby the second lateral wing 10b, is pivotable in relation to the base part 5 about the second pivot axis A2 under the effect of this second main hydraulic cylinder 30b.
Each lateral wing 10a, 10b is slidably mounted to the associated support frame 20a, 20b in order to allow the lateral wing 10a, 10b to move upwards and downwards in relation to the support frame 20a, 20b between a lowermost position (see Figs 4a and 5a) and an uppermost position in directions parallel to the associated pivot axis A1, A2.
In the illustrated embodiment, the first and second lateral wings 10a, 10b are connected to the associated support frame 20a, 20b via a respective slide guiding mechanism 40a, 40b. Each slide guiding mechanism 40a, 40b comprises an elongated guide groove 41, which is provided in the associated support frame 20a, 20b and extends in vertical direction in parallel with the pivot axis A1, A2 of the support frame, and a guide member 42, which is mounted to the associated lateral wing 10a, 10b and slidably received in said guide groove 41. Each lateral wing 10a, 10b is moveable upwards and downwards in relation to the associated support frame 20a, 20b in directions parallel to the pivot axis A1, A2 of the support frame by sliding of the guide member 42 along the associated guide groove 41.
Each slide guiding mechanism 40a, 40b is with advantage provided with a rotary bearing 43 (see Fig 8) that allows the associated lateral wing 10a, 10b to tilt in relation to its support frame 20a, 20b about an essentially horizontal pivot axis A3 defined by the rotary bearing 43. Two different tilting positions of the first lateral wing 10a in relation to the first support frame 20a are illustrated in Figs 6a and 6b. In the illustrated embodiment, the guide member 42 of each slide guiding mechanism 40a, 40b has a polygonal cross-sectional shape and is prevented from rotating in the associated guide groove 41, wherein the rotary bearing 43 of each slide guiding mechanism 40a, 40b is arranged in the guide member 42 of the slide guiding mechanism and configured to allow the associated lateral wing 10a, 10b to rotate in relation to this guide member 42. In Fig 8, the guide member 42 and the parts of the rotary bearing 43 included in the first slide guiding mechanism 40a are shown separated from each other and from the first lateral wing 10a. In this case, the rotary bearing 43 has the form of a rotary slide bearing and comprises a bearing sleeve 44, which is received in a cylindrical cavity in the guide member 42, and a shaft 45, which is received in the bearing sleeve 44. The guide member 42, the bearing sleeve 44 and the shaft 45 are mounted to the associated lateral wing by means of a bolt 46, which extends through the shaft 45 and through a hole 47 in the lateral wing and which is fixed to the lateral wing by means of a nut 48 (see Fig 7). The rotary bearing 43 may of course also be designed in any other suitable manner.
As an alternative, the guide member 42 of each slide guiding mechanism 40a, 40b may be fixedly mounted to the associated lateral wing 10a, 10b and have a circular cross-sectional shape in order to allow the lateral wing 10a, 10b to tilt in relation to its support frame 20a, 20b by rotation of the guide member 42 in the associated guide groove 41.
In the illustrated embodiment, each support frame 20a, 20b is provided with a convexly curved slide member 23 (see Figs 7 and 8) at each of its opposite lateral ends, wherein these slide members 23 are slidably received in a respective one of two U-shaped grooves 13 provided at the opposite lateral ends of the associated lateral wing 10a, 10b. The slide members 23 and the U-shaped grooves 13 ensure a stable contact between each lateral wing 10a, 10b and its support frame 20a, 20b, while allowing the lateral wing to tilt in relation to the support frame about the pivot axis A3 defined by the rotary bearing 43.
In the illustrated embodiment, each lateral wing 10a, 10b is provided with stop members 14, which are fixed to the lateral wing and configured to abut against a respective shoulder 24 on the associated support frame 20a, 20b when the lateral wing is in its lowermost position in relation to the support frame, for instance when the scraping device 1 has been lifted from the ground. The stop members 24 also limit the possible tilting angle of the lateral wing in relation to the associated support frame. In the illustrated example, two such stop members 14 are provided on each lateral wing 10a, 10b. A neutral tilting position of each lateral wing 10a, 10b in relation to its support frame 20a, 20b is defined by the stop members 14 of the lateral wing 10a, 10b when both stop members 24 are in contact with the corresponding shoulders 24 on the support frame 20a, 20b.
A first spring mechanism 50a is configured to act between the first support frame 20a and the first lateral wing 10a and a second spring mechanism 50b is configured to act between the second support frame 20b and the second lateral wing 10b, wherein each spring mechanism 50a, 50b is configured to urge the associated lateral wing 10a, 10b towards its neutral tilting position in relation to its support frame 20a, 20b and towards its lowermost position in relation to its support frame. Thus, each lateral wing 10a, 10b is moveable upwards in relation to its support frame 20a, 20b against the action of the associated spring mechanism 50a, 50b and tiltable in relation to its support frame in any direction from the neutral tilting position against the action of the associated spring mechanism 50a, 50b.
In the illustrated embodiment, each spring mechanism 50a, 50b comprises two spring members 51, which are fixed to the associated lateral wing 10a, 10b, wherein each spring member 51 comprises a spring arm 52 that is in sliding contact with a stop member 53 on the lateral wing 10a, 10b and pressed against this stop member 53 by spring force. The spring mechanisms 50a, 50b may of course also be designed in any other suitable manner.
The scraping device 1 comprises:

a first lifting mechanism 60a, which is mounted to the first support frame 20a and capable of lifting the first lateral wing 10a upwards in relation to the first support frame 20a from its lowermost position (see Fig 4a) to a raised resting position (see Fig 4b); and
a second lifting mechanism 60b, which is mounted to the second support frame 20b and capable of lifting the second lateral wing 10b upwards in relation to the second support frame 20b from its lowermost position (see Fig 5a) to a raised resting position (see Fig 5b).

A hydraulic cylinder 70a, in the following referred to as first auxiliary hydraulic cylinder, is connected to the first lifting mechanism 60a, wherein the first lifting mechanism 60a is actuatable by the first auxiliary hydraulic cylinder 70a to lift the first lateral wing 10a upwards in relation to the first support frame 20a from its lowermost position to its raised resting position. Another hydraulic cylinder 70b, in the following referred to as second auxiliary hydraulic cylinder, is connected to the second lifting mechanism 60b, wherein the second lifting mechanism 60b is actuatable by the second auxiliary hydraulic cylinder 70b to lift the second lateral wing 10b upwards in relation to the second support frame 20b from its lowermost position to its raised resting position. The vertical distance between the lowermost position and the raised resting position of each lateral wing 10a, 10b is for instance in the order of 2-10 cm, preferably 2-5 cm.
In the illustrated embodiment, the first lifting mechanism 60a comprises two levers 61, 62, in the following referred to as first and second levers, which are pivotally mounted to the first support frame 20a and pivotable in relation to the first support frame 20a by the first auxiliary hydraulic cylinder 70a from a lowered inactive position (see Fig 4a) to a raised lifting position (see Fig 4b) in order to come into contact with a respective shoulder 15 on the first lateral wing 10a and push the first lateral wing 10a upwards in relation to the first support frame 20a from its lowermost position to its raised resting position. In this case, also the second lifting mechanism 60b comprises two levers 63, 64, in the following referred to as third and fourth levers, which are pivotally mounted to the second support frame 20b and pivotable in relation to the second support frame 20b by the second auxiliary hydraulic cylinder 70b from a lowered inactive position (see Fig 5a) to a raised lifting position (see Fig 5b) in order to come into contact with a respective shoulder 15 on the second lateral wing 10b and push the second lateral wing 10b upwards in relation to the second support frame 20b from its lowermost position to its raised resting position.
The first lever 61 is pivotally mounted to the first support frame 20a through a first joint J1 (see Fig 4a) and articulately connected to a piston rod 71 of the first auxiliary hydraulic cylinder 70a through a second joint J2. The second lever 62 is pivotally mounted to the first support frame 20a through a third joint J3 and articulately connected to a cylinder housing 72 of the first auxiliary hydraulic cylinder 70a through a fourth joint J4. By an extension of the first auxiliary hydraulic cylinder 70a, the first and second levers 61, 62 are pivotable, from the lowered inactive position to the raised lifting position, about a respective pivot axis P1, P2 formed by said first joint J1 and third joint J3 respectively.
The third lever 63 is pivotally mounted to the second support frame 20b through a fifth joint J5 (see Fig 5a) and articulately connected to a piston rod 71 of the second auxiliary hydraulic cylinder 70b through a sixth joint J6. The fourth lever 64 is pivotally mounted to the second support frame 20b through a seventh joint J7 and articulately connected to a cylinder housing 72 of the second auxiliary hydraulic cylinder 70b through an eighth joint J8. By an extension of the second auxiliary hydraulic cylinder 70b, the third and fourth levers 63, 64 are pivotable, from the lowered inactive position to the raised lifting position, about a respective pivot axis P3, P4 formed by said fifth joint J5 and seventh joint J7 respectively.
In the illustrated embodiment, each support frame 20a, 20b comprises an upper support plate 25 at its upper end, wherein the associated lateral wing 10a, 10b is configured to rest against this upper support plate 25 when it is in its lowermost position in relation to the support frame 20a, 20b. The first and second levers 61, 62 extend through a respective recess 26 (see Fig 8) in the upper support plate 25 of the first support frame 20a, whereas the third and fourth levers 63, 64 extend through a respective recess 26 in the upper support plate 25 of the second support frame 20b.
The first and second lifting mechanisms 60a, 60b may of course also be designed in any other suitable manner.
The first auxiliary hydraulic cylinder 70a is mounted to the first support frame 20a and the second auxiliary hydraulic cylinder 70b is mounted to the second support frame 20b. In the illustrated embodiment, the first auxiliary hydraulic cylinder 70a is suspended between the levers 61, 62 of the first lifting mechanism 60a and consequently mounted to the first support frame 20a via these levers 61, 62, whereas the second auxiliary hydraulic cylinder 70b is suspended between the levers 63, 64 of the second lifting mechanism 60b and consequently mounted to the second support frame 20b via these levers 63, 64. However, each auxiliary hydraulic cylinder 70a, 70b may as an alternative be mounted directly to the associated support frame 20a, 20b.
In the illustrated embodiment, the auxiliary hydraulic cylinders 70a, 70b are double-acting hydraulic cylinders. In addition to the above-mentioned piston rod 71 and cylinder housing 72, each auxiliary hydraulic cylinder 70a, 70b also comprises a piston 73 (schematically illustrated in Fig 9) that is slidably received in an internal space of the cylinder housing 72 and configured to divide this space into a first chamber 74 on a first side of the piston and a second chamber 75 on an opposite second side of the piston, wherein the piston rod 71 is fixed to the piston 73 and extends through the second chamber 75. In the corresponding manner, each main hydraulic cylinder 30a, 30b comprises a piston rod 31, a cylinder housing 32 and a piston 33 that is slidably received in an internal space of the cylinder housing 32 and configured to divide this space into a first chamber 34 on a first side of the piston and a second chamber 35 on an opposite second side of the piston, wherein the piston rod 31 is fixed to the piston 33 and extends through the second chamber 35.
The scraping device 1 comprises a hydraulic system 80, to which the main hydraulic cylinders 30a, 30b and the auxiliary hydraulic cylinders 70a, 70b are connected. A preferred variant of this hydraulic system 80 is illustrated in Fig 9 and will be described in closer detail below. However, the hydraulic system 80 may also have any other suitable layout.
The hydraulic system 80 comprises:

a first hydraulic line L1 connected to the second chamber 35 of the first main hydraulic cylinder 30a, wherein the first lateral wing 10a is pivotable by the first main hydraulic cylinder 30a towards its swung-in non-operative position by feeding of hydraulic fluid into this chamber 35 via the first hydraulic line L1;
a second hydraulic line L2 arranged between the first hydraulic line L1 and the first chamber 74 of the first auxiliary hydraulic cylinder 70a, wherein the first lifting mechanism 60a is actuatable by the first auxiliary hydraulic cylinder 70a to lift the first lateral wing 10a towards its raised resting position by feeding of hydraulic fluid into this chamber 74 via the second hydraulic line L2;
a third hydraulic line L3 connected to the second chamber 35 of the second main hydraulic cylinder 30b, wherein the second lateral wing 10b is pivotable by the second main hydraulic cylinder 30b towards its swung-in non-operative position by feeding of hydraulic fluid into this chamber 35 via the third hydraulic line L3; and
a fourth hydraulic line L4 arranged between the third hydraulic line L3 and the first chamber 74 of the second auxiliary hydraulic cylinder 70b, wherein the second lifting mechanism 60b is actuatable by the second auxiliary hydraulic cylinder 70b to lift the second lateral wing 10b towards its raised resting position by feeding of hydraulic fluid into this chamber 74 via the fourth hydraulic line L4.

A first pressure relief valve 81a is arranged in the second hydraulic line L2 and shiftable between a closed position, in which it is configured to prevent fluid flow from the first hydraulic line L1 to the first chamber 74 of the first auxiliary hydraulic cylinder 70a via the second hydraulic line L2, and an open position, in which it is configured to allow fluid flow from the first hydraulic line L1 to the first chamber 74 of the first auxiliary hydraulic cylinder 70a via the second hydraulic line L2. A second pressure relief valve 81b is arranged in the fourth hydraulic line L4 and shiftable between a closed position, in which it is configured to prevent fluid flow from the third hydraulic line L3 to the first chamber 74 of the second auxiliary hydraulic cylinder 70b via the fourth hydraulic line L4, and an open position, in which it is configured to allow fluid flow from the third hydraulic line L3 to the first chamber 74 of the second auxiliary hydraulic cylinder 70b via the fourth hydraulic line L4. The first pressure relief valve 81a is configured to assume its open position when the hydraulic pressure in the first hydraulic line L1 exceeds a predetermined level, and the second pressure relief valve 81b is configured to assume its open position when the hydraulic pressure in the third hydraulic line L3 exceeds a predetermined level.
The set pressure, i.e. the opening pressure, of the first pressure relief valve 81a is so adapted that it will open by the pressure that is built up in the first hydraulic line L1 when the first main hydraulic cylinder 30a has moved the first lateral wing 10a to its swung-in non-operative position and the piston 33 of the first main hydraulic cylinder 30a thereby has reached an end position in the cylinder housing 32. Thus, hydraulic fluid will be fed into the first chamber 74 of the first auxiliary hydraulic cylinder 70a when the first lateral wing 10a has reached its swung-in non-operative position, and the first auxiliary hydraulic cylinder 70a will thereby automatically actuate the first lifting mechanism 60a to move the first lateral wing 10a to its raised resting position as a consequence of the first lateral wing 10a reaching its swung-in non-operative position. The set pressure of the second pressure relief valve 81b is so adapted that it will open by the pressure that is built up in the third hydraulic line L3 when the second main hydraulic cylinder 30b has moved the second lateral wing 10b to its swung-in non-operative position and the piston 33 of the second main hydraulic cylinder 30b thereby has reached an end position in the cylinder housing 32. Thus, hydraulic fluid will be fed into the first chamber 74 of the second auxiliary hydraulic cylinder 70b when the second lateral wing 10b has reached its swung-in non-operative position, and the second auxiliary hydraulic cylinder 70b will thereby automatically actuate the second lifting mechanism 60b to move the second lateral wing 10b to its raised resting position as a consequence of the second lateral wing 10b reaching its swung-in non-operative position.
The hydraulic system 80 further comprises:

a fifth hydraulic line L5 connected to the first chamber 34 of the first main hydraulic cylinder 30a, wherein the first lateral wing 10a is pivotable by the first main hydraulic cylinder 30a towards its swung-out operative position by feeding of hydraulic fluid into this chamber 34 via the fifth hydraulic line L5; and
a sixth hydraulic line L6 connected to the first chamber 34 of the second main hydraulic cylinder 30b, wherein the second lateral wing 10b is pivotable by the second main hydraulic cylinder 30b towards its swung-out operative position by feeding of hydraulic fluid into this chamber 34 via the sixth hydraulic line L6.

A pilot-operated first load-holding valve 82a is arranged in the second hydraulic line L2 in series with the first pressure relief valve 81a and shiftable between a closed position, in which it is configured to prevent fluid flow out of the first chamber 74 of the first auxiliary hydraulic cylinder 70a, and an open position, in which it is configured to allow fluid flow out of the first chamber 74 of the first auxiliary hydraulic cylinder 70a. The first load-holding valve 82a comprises a pilot line 83a connected to the fifth hydraulic line L5 and it is configured to assume its open position when the hydraulic pressure in the fifth hydraulic line L5, and thereby in the pilot line 83a, exceeds a predetermined level. In the illustrated example, the pilot line 83a is connected to the fifth hydraulic line L5 via a seventh hydraulic line L7, which is arranged between the fifth hydraulic line L5 and the second chamber 75 of the first auxiliary hydraulic cylinder 70a. Thus, fluid flow from the fifth hydraulic line L5 to the second chamber 75 of the first auxiliary hydraulic cylinder 70a is allowed via the seventh hydraulic line L7 when the first load-holding valve 82a is in its open position.
A pilot-operated second load-holding valve 82b is arranged in the fourth hydraulic line L4 in series with the second pressure relief valve 81b and shiftable between a closed position, in which it is configured to prevent fluid flow out of the first chamber 74 of the second auxiliary hydraulic cylinder 70b, and an open position, in which it is configured to allow fluid flow out of the first chamber 74 of the second auxiliary hydraulic cylinder 70b. The second load-holding valve 82b comprises a pilot line 83b connected to the sixth hydraulic line L6 and it is configured to assume its open position when the hydraulic pressure in the sixth hydraulic line L6, and thereby in the pilot line 83b, exceeds a predetermined level. In the illustrated example, the pilot line 83b is connected to the sixth hydraulic line L6 via an eighth hydraulic line L8, which is arranged between the sixth hydraulic line L6 and the second chamber 75 of the second auxiliary hydraulic cylinder 70b. Thus, fluid flow from the sixth hydraulic line L6 to the second chamber 75 of the second auxiliary hydraulic cylinder 70b is allowed via the eighth hydraulic line L8 when the second load-holding valve 82b is in its open position. The load-holding valves 82a, 82b ensure that the lateral wings 10a, 10b are maintained in the raised resting position under the effect of the auxiliary hydraulic cylinders 70a, 70b as long as the lateral wings remain in the swung-in non-operative position.
When the first lateral wing 10a is moved from the swung-in non-operative position towards the swung-out operative position under the effect of the first main hydraulic cylinder 30a and an increased pressure is built up in the first chamber 34 of the first main hydraulic cylinder and in the fifth hydraulic line L5, the first load-holding valve 82a will open and allow hydraulic fluid to flow out of the first chamber 74 of the first auxiliary hydraulic cylinder 70a, wherein the levers 61, 62 of the first lifting mechanism 60a are allowed to return to the lowered inactive position under the combined effect of the gravity on the first lateral wings 10a, the spring forces from the spring members 51 of the first spring mechanism 50a and the hydraulic pressure developed in the second chamber 75 of the first auxiliary hydraulic cylinder 70a. When the second lateral wing 10b is moved from the swung-in non-operative position towards the swung-out operative position under the effect of the second main hydraulic cylinder 30b and an increased pressure is built up in the first chamber 34 of the second main hydraulic cylinder and in the sixth hydraulic line L6, the second load-holding valve 82b will open and allow hydraulic fluid to flow out of the first chamber 74 of the second auxiliary hydraulic cylinder 70b, wherein the levers 63, 64 of the second lifting mechanism 60b are allowed to return to the lowered inactive position under the combined effect of the gravity on the second lateral wings 10b, the spring forces from the spring members 51 of the second spring mechanism 50b and the hydraulic pressure developed in the second chamber 75 of the second auxiliary hydraulic cylinder 70b.
In the illustrated example, a first one-way restrictor valve 84a is arranged in the first hydraulic line L1 and a second one-way restrictor valve 84b is arranged in the third hydraulic line L3. The first one-way restrictor valve 84a is configured to restrict the hydraulic flow in the first hydraulic line L1 away from the second chamber 35 of the first main hydraulic cylinder 30a, to thereby cause a build-up of hydraulic pressure in the fifth hydraulic line L5 when hydraulic fluid is fed into the first chamber 34 of the first main hydraulic cylinder 30a via the fifth hydraulic line L5. The second one-way restrictor valve 84b is configured to restrict the hydraulic flow in the third hydraulic line L3 away from the second chamber 35 of the second main hydraulic cylinder 30b, to thereby cause a build-up of hydraulic pressure in the sixth hydraulic line L6 when hydraulic fluid is fed into the first chamber 34 of the second main hydraulic cylinder 30b via the sixth hydraulic line L6.
In the illustrated example, the hydraulic system 80 also comprises a first check valve 85a arranged in the second hydraulic line L2 in parallel with the first pressure relief valve 81a and a second check valve 85b arranged in the fourth hydraulic line L4 in parallel with the second pressure relief valve 81b. The first check valve 85a is configured to allow hydraulic fluid in the second hydraulic line L2 to bypass the first pressure relief valve 81a in the direction towards the first hydraulic line L1 when the first load-holding valve 82a is open and to obstruct fluid flow in the opposite direction. The second check valve 85b is configured to allow hydraulic fluid in the fourth hydraulic line L4 to bypass the second pressure relief valve 81b in the direction towards the third hydraulic line L3 when the second load-holding valve 82b is open and to obstruct fluid flow in the opposite direction.
With the layout of the hydraulic system 80 illustrated in Fig 9, the actuation of each auxiliary hydraulic cylinder 70a, 70b is achieved in an automatic and fully hydraulic manner without requiring any electronic equipment in the form of sensors, control units or the similar. However, the hydraulic system 80 may as an alternative be provided with manually operated valves for controlling the flow of hydraulic fluid to the auxiliary hydraulic cylinders 70a, 70b.
The flow of hydraulic fluid to the main hydraulic cylinders 30a, 30b are controlled by suitable valves 87, for instance in the form of directional control valves, which may be included in the hydraulic system 80 of the scraping device 1 or included in the hydraulic system of the vehicle to which the scraping device is mounted.
The invention is of course not in any way restricted to the embodiments described above. On the contrary, many possibilities to modifications thereof will be apparent to a person with ordinary skill in the art without departing from the basic idea of the invention such as defined in the appended claims.

Claims

A scraping device for removal of snow, ice or other material from a surface, such as a road surface or ground surface, the scraping device (1) comprising:
- attachment means (2), by means of which the scraping device (1) is mountable to a vehicle;

- a central base part (5) provided with a lower scraping edge (6), wherein the base part (5) is connected to the attachment means (2) in order to allow the base part (5) to be carried by the vehicle via the attachment means (2);

- first and second lateral wings (10a, 10b) arranged on opposite sides of the base part (5), wherein each one of the first and second lateral wings (10a, 10b) is provided with a lower scraping edge (11);

- a first support frame (20a), wherein the first lateral wing (10a) is mounted to the first support frame (20a) and wherein the first support frame (20a) is hinged to the base part (5) and pivotable in relation to the base part (5) about a first pivot axis (A1) to thereby allow the first lateral wing (10a) to be pivoted in relation to the base part (5) together with the first support frame (20a) about the first pivot axis (A1) between a swung-in non-operative position and a swung-out operative position, the first lateral wing (10a) being slidably mounted to the first support frame (20a) in order to allow the first lateral wing (10a) to move upwards and downwards in relation to the first support frame (20a) between a lowermost position and an uppermost position in directions parallel to the first pivot axis (A1);

- a second support frame (20b), wherein the second lateral wing (10b) is mounted to the second support frame (20b) and wherein the second support frame (20b) is hinged to the base part (5) and pivotable in relation to the base part (5) about a second pivot axis (A2) to thereby allow the second lateral wing (10b) to be pivoted in relation to the base part (5) together with the second support frame (20b) about the second pivot axis (A2) between a swung-in non-operative position and a swung-out operative position, the second lateral wing (10b) being slidably mounted to the second support frame (20b) in order to allow the second lateral wing (10b) to move upwards and downwards in relation to the second support frame (20b) between a lowermost position and an uppermost position in directions parallel to the second pivot axis (A2);

- a first main hydraulic cylinder (30a) for pivoting the first support frame (20a) in relation to the base part (5) about the first pivot axis (A1); and

- a second main hydraulic cylinder (30b) for pivoting the second support frame (20b) in relation to the base part (5) about the second pivot axis (A2);
characterized in that the scraping device (1) further comprises:
- a first lifting mechanism (60a), which is mounted to the first support frame (20a) and capable of lifting the first lateral wing (10a) upwards in relation to the first support frame (20a) from its lowermost position to a raised resting position;

- a second lifting mechanism (60b), which is mounted to the second support frame (20b) and capable of lifting the second lateral wing (10b) upwards in relation to the second support frame (20b) from its lowermost position to a raised resting position;

- a first auxiliary hydraulic cylinder (70a) connected to the first lifting mechanism (60a), wherein the first lifting mechanism (60a) is actuatable by the first auxiliary hydraulic cylinder (70a) to lift the first lateral wing (10a) upwards in relation to the first support frame (20a) from its lowermost position to its raised resting position; and

- a second auxiliary hydraulic cylinder (70b) connected to the second lifting mechanism (60b), wherein the second lifting mechanism (60b) is actuatable by the second auxiliary hydraulic cylinder (70b) to lift the second lateral wing (10b) upwards in relation to the second support frame (20b) from its lowermost position to its raised resting position.
A scraping device according to claim 1, characterized in:
- that the first lifting mechanism (60a) comprises two levers (61, 62), here denominated first and second levers, which are pivotally mounted to the first support frame (20a), wherein each one of the first and second levers (61, 62) is pivotable in relation to the first support frame (20a) by the first auxiliary hydraulic cylinder (70a) from a lowered inactive position to a raised lifting position in order to push the first lateral wing (10a) upwards in relation to the first support frame (20a) from its lowermost position to its raised resting position; and

- that the second lifting mechanism (60b) comprises two levers (63, 64), here denominated third and fourth levers, which are pivotally mounted to the second support frame (20b), wherein each one of the third and fourth levers (63, 64) is pivotable in relation to the second support frame (20b) by the second auxiliary hydraulic cylinder (70b) from a lowered inactive position to a raised lifting position in order to push the second lateral wing (10b) upwards in relation to the second support frame (20b) from its lowermost position to its raised resting position.
A scraping device according to claim 2, characterized in:
- that the first support frame (20a) comprises an upper support plate (25) located at an upper end of the first support frame, wherein the first lateral wing (10a) is configured to rest against this upper support plate (25) when it is in its lowermost position in relation to the first support frame, and wherein the first and second levers (61, 62) extend through a respective recess (26) in this upper support plate (25); and

- that the second support frame (20b) comprises an upper support plate (25) located at an upper end of the second support frame, wherein the second lateral wing (10b) is configured to rest against this upper support plate (25) when it is in its lowermost position in relation to the second support frame, and wherein the third and fourth levers (63, 64) extend through a respective recess (26) in this upper support plate (25).
A scraping device according to claim 2 or 3, characterized in:
- that the first lever (61) is pivotally mounted to the first support frame (20a) through a first joint (J1) and articulately connected to a piston rod (71) of the first auxiliary hydraulic cylinder (70a) through a second joint (J2);

- that the second lever (62) is pivotally mounted to the first support frame (20a) through a third joint (J3) and articulately connected to a cylinder housing (72) of the first auxiliary hydraulic cylinder (70a) through a fourth joint (J4);

- that the first and second levers (61, 62) by an extension of the first auxiliary hydraulic cylinder (70a) are pivotable, from the lowered inactive position to the raised lifting position, about a respective pivot axis (P1, P2) formed by said first joint (J1) and third joint (J3) respectively;

- that the third lever (63) is pivotally mounted to the second support frame (20b) through a fifth joint (J5) and articulately connected to a piston rod (71) of the second auxiliary hydraulic cylinder (70b) through a sixth joint (J6);

- that the fourth lever (64) is pivotally mounted to the second support frame (20b) through a seventh joint (J7) and articulately connected to a cylinder housing (72) of the second auxiliary hydraulic cylinder (70b) through an eighth joint (J8); and

- that the third and fourth levers (63, 64) by an extension of the second auxiliary hydraulic cylinder (70b) are pivotable, from the lowered inactive position to the raised lifting position, about a respective pivot axis (P3, P4) formed by said fifth joint (J5) and seventh joint (J7) respectively.
A scraping device according to any of claims 1-4, characterized in:
- that the first lateral wing (10a) is connected to the first support frame (20a) via a first slide guiding mechanism (40a) comprising an elongated guide groove (41), which is provided in the first support frame (20a) and extends in parallel with the first pivot axis (A1), and a guide member (42), which is mounted to the first lateral wing (10a) and slidably received in said guide groove (41), wherein the first lateral wing (10a) is moveable upwards and downwards in relation to the first support frame (20a) in directions parallel to the first pivot axis (A1) by sliding of said guide member (42) along the associated guide groove (41); and

- that the second lateral wing (10b) is connected to the second support frame (20b) via a second slide guiding mechanism (40b) comprising an elongated guide groove (41), which is provided in the second support frame (20b) and extends in parallel with the second pivot axis (A2), and a guide member (42), which is mounted to the second lateral wing (10b) and slidably received in said guide groove (41), wherein the second lateral wing (10b) is moveable upwards and downwards in relation to the second support frame (20b) in directions parallel to the second pivot axis (A2) by sliding of said guide member (42) along the associated guide groove (41).
A scraping device according to claim 5, characterized in:
- that the first slide guiding mechanism (40a) comprises a rotary bearing (43) that allows the first lateral wing (10a) to tilt in relation to the first support frame (20a); and

- that the second slide guiding mechanism (40b) comprises a rotary bearing (43) that allows the second lateral wing (10b) to tilt in relation to the second support frame (20b).
A scraping device according to claim 6, characterized in:
- that the guide member (42) of the first slide guiding mechanism (40a) has such a shape that it is prevented from rotating in the associated guide groove (41), wherein the rotary bearing (43) of the first slide guiding mechanism (40a) is arranged in the guide member (42) of the first slide guiding mechanism and configured to allow the first lateral wing (10a) to rotate in relation to this guide member (42); and

- that the guide member (42) of the second slide guiding mechanism (40b) has such a shape that it is prevented from rotating in the associated guide groove (41), wherein the rotary bearing (43) of the second slide guiding mechanism (40b) is arranged in the guide member (42) of the second slide guiding mechanism and configured to allow the second lateral wing (10b) to rotate in relation to this guide member (42).
A scraping device according to claim 6 or 7, characterized in:
- that the scraping device (1) comprises a first spring mechanism (50a) acting between the first support frame (20a) and the first lateral wing (10a), wherein the first spring mechanism (50a) is configured to urge the first lateral wing (10a) towards a neutral tilting position in relation to the first support frame (20a) and towards its lowermost position in relation to the first support frame; and

- that the scraping device (1) comprises a second spring mechanism (50b) acting between the second support frame (20b) and the second lateral wing (10b), wherein the second spring mechanism (50b) is configured to urge the second lateral wing (10b) towards a neutral tilting position in relation to the second support frame (20b) and towards its lowermost position in relation to the second support frame.
A scraping device according to any of claims 1-8, characterized in that the base part (5) has the form of a bucket.
A scraping device according to any of claims 1-9, characterized in:
- that each one of the main hydraulic cylinders (30a, 30b) and auxiliary hydraulic cylinders (70a, 70b) comprises a cylinder housing (32, 72), a piston (33, 73) that is slidably received in an internal space of the cylinder housing (32, 72) and configured to divide this space into a first chamber (34, 74) on a first side of the piston and a second chamber (35, 75) on an opposite second side of the piston, and a piston rod (31, 71) that is fixed to the piston (33, 73); and

- that the scraping device (1) comprises a hydraulic system (80), which comprises:
• a first hydraulic line (L1) connected to the second chamber (35) of the first main hydraulic cylinder (30a), wherein the first lateral wing (10a) is pivotable by the first main hydraulic cylinder (30a) towards its swung-in non-operative position by feeding of hydraulic fluid into this chamber (35) via the first hydraulic line (L1),

• a second hydraulic line (L2) arranged between the first hydraulic line (L1) and the first chamber (74) of the first auxiliary hydraulic cylinder (70a), wherein the first lifting mechanism (60a) is actuatable by the first auxiliary hydraulic cylinder (70a) to lift the first lateral wing (10a) towards its raised resting position by feeding of hydraulic fluid into this chamber (74) via the second hydraulic line (L2),

• a first pressure relief valve (81a) arranged in the second hydraulic line (L2) and shiftable between a closed position, in which it is configured to prevent fluid flow from the first hydraulic line (L1) to the first auxiliary hydraulic cylinder (70a) via the second hydraulic line (L2), and an open position, in which it is configured to allow fluid flow from the first hydraulic line (L1) to the first auxiliary hydraulic cylinder (70a) via the second hydraulic line (L2), wherein the first pressure relief valve (81a) is configured to assume its open position when the hydraulic pressure in the first hydraulic line (L1) exceeds a predetermined level,

• a third hydraulic line (L3) connected to the second chamber (35) of the second main hydraulic cylinder (30b), wherein the second lateral wing (10b) is pivotable by the second main hydraulic cylinder (30b) towards its swung-in non-operative position by feeding of hydraulic fluid into this chamber (35) via the third hydraulic line (L3),

• a fourth hydraulic line (L4) arranged between the third hydraulic line (L3) and the first chamber (74) of the second auxiliary hydraulic cylinder (70b), wherein the second lifting mechanism (60b) is actuatable by the second auxiliary hydraulic cylinder (70b) to lift the second lateral wing (10b) towards its raised resting position by feeding of hydraulic fluid into this chamber (74) via the fourth hydraulic line (L4), and

• a second pressure relief valve (81b) arranged in the fourth hydraulic line (L4) and shiftable between a closed position, in which it is configured to prevent fluid flow from the third hydraulic line (L3) to the second auxiliary hydraulic cylinder (70b) via the fourth hydraulic line (L4), and an open position, in which it is configured to allow fluid flow from the third hydraulic line (L3) to the second auxiliary hydraulic cylinder (70b) via the fourth hydraulic line (L4), wherein the second pressure relief valve (81b) is configured to assume the open position when the hydraulic pressure in the third hydraulic line (L3) exceeds a predetermined level.
A scraping device according to claim 10, characterized in that the hydraulic system (80) further comprises:
- a fifth hydraulic line (L5) connected to the first chamber (34) of the first main hydraulic cylinder (30a), wherein the first lateral wing (10a) is pivotable by the first main hydraulic cylinder (30a) towards its swung-out operative position by feeding of hydraulic fluid into this chamber (34) via the fifth hydraulic line (L5);

- a pilot-operated first load-holding valve (82a) arranged in the second hydraulic line (L2) and shiftable between a closed position, in which it is configured to prevent fluid flow out of the first chamber (74) of the first auxiliary hydraulic cylinder (70a), and an open position, in which it is configured to allow fluid flow out of the first chamber (74) of the first auxiliary hydraulic cylinder (70a), wherein the first load-holding valve (82a) comprises a pilot line (83a) connected to the fifth hydraulic line (L5), and wherein the first load-holding valve (82a) is configured to assume its open position when the hydraulic pressure in the fifth hydraulic line (L5), and thereby in said pilot line (83a), exceeds a predetermined level;

- a sixth hydraulic line (L6) connected to the first chamber (34) of the second main hydraulic cylinder (30b), wherein the second lateral wing (10b) is pivotable by the second main hydraulic cylinder (30b) towards its swung-out operative position by feeding of hydraulic fluid into this chamber (34) via the sixth hydraulic line (L6); and

- a pilot-operated second load-holding valve (82b) arranged in the fourth hydraulic line (L4) and shiftable between a closed position, in which it is configured to prevent fluid flow out of the first chamber (74) of the second auxiliary hydraulic cylinder (70b), and an open position, in which it is configured to allow fluid flow out of the first chamber (74) of the second auxiliary hydraulic cylinder (70b), wherein the second load-holding valve (82b) comprises a pilot line (83b) connected to the sixth hydraulic line (L6), and wherein the second load-holding valve (82b) is configured to assume its open position when the hydraulic pressure in the sixth hydraulic line (L6), and thereby in said pilot line (83b), exceeds a predetermined level.
A scraping device according to claim 11, characterized in that the hydraulic system (80) further comprises:
- a first one-way restrictor valve (84a) arranged in the first hydraulic line (L1) and configured to restrict the hydraulic flow in the first hydraulic line (L1) away from the second chamber (35) of the first main hydraulic cylinder (30a), to thereby cause a build-up of hydraulic pressure in the fifth hydraulic line (L5) when hydraulic fluid is fed into the first chamber (34) of the first main hydraulic cylinder (30a) via the fifth hydraulic line (L5); and

- a second one-way restrictor valve (84b) arranged in the third hydraulic line (L3) and configured to restrict the hydraulic flow in the third hydraulic line (L3) away from the second chamber (35) of the second main hydraulic cylinder (30b), to thereby cause a build-up of hydraulic pressure in the sixth hydraulic line (L6) when hydraulic fluid is fed into the first chamber (34) of the second main hydraulic cylinder (30b) via the sixth hydraulic line (L6).
A scraping device according to claim 11 or 12, characterized in that the hydraulic system (80) further comprises:
- a seventh hydraulic line (L7) arranged between the fifth hydraulic line (L5) and the second chamber (75) of the first auxiliary hydraulic cylinder (70a) in order to allow fluid flow from the fifth hydraulic line (L5) to this chamber (75) when the first load-holding valve (82a) is in its open position; and

- an eighth hydraulic line (L8) arranged between the sixth hydraulic line (L6) and the second chamber (75) of the second auxiliary hydraulic cylinder (70b) in order to allow fluid flow from the sixth hydraulic line (L6) to this chamber (75) when the second load-holding valve (82b) is in its open position.