NL2017563B1 - Grab shell, grab and method of manufacturing a grab shell - Google Patents

Abstract

Grab shell, comprising a bent bottom of which two opposing edges are each provided with a side wall. The bottom and side walls include sheet metal with which a shell space is formed for holding material to be grabbed. Sheet metal of at least one side wall connects to sheet metal of the bottom via a bent edge portion in the sheet metal of the side wall.

Description

Patent center

The Netherlands

Θ 2017563

BI PATENT @ Int. Cl .:

B66C 3/02 (2017.01) E02F 3/40 (2017.01) (21) Application number: 2017563 © Application submitted: 30/09/2016

Al) Application registered: (73) Patent holder (s): 10/04/2018 Nemag B.V. at Zierikzee. (43) Application published: - (72) Inventor (s): Leendert Gommert from Koeveringe (47) Patent granted: at Zierikzee. 10/04/2018 Michel Corbeau in Zierikzee. (45) Patent issued: 11/04/2018 (74) Agent: ir. C.M. Jansen et al. In The Hague.

54) Grab shell, grab and method or manufacturing a grab shell

Grab shell, including a bottom of which two opposing edges are each provided with a side wall. The bottom and side walls include sheet metal with which a shell space is formed for holding material to be grabbed. Sheet metal or at least one side wall connects to sheet metal or the bottom via a are edge portion in the sheet metal or the side wall.

NL BI 2017563

This patent has been granted regardless of the attached result of the research into the state of the art and written opinion. The patent corresponds to the documents originally submitted.

P113187NL00

Title: Grab shell, grab and method or manufacturing a grab shell

The invention relates to a grab shell for a grab, a grab including a grab shell and a method of manufacturing a grab shell.

Grab shells are known per se, and are often used in grabs for handling bulk materials by grabbing.

A grab shell typically comprises a bottom of which two opposing edges are each provided with a side wall. The bottom and side walls include sheet metal with which a shell space is formed for holding material to be grabbed, e.g. coal, ore, biomass, minerals or rocks. A free edge of the bottom and adjoining free edges of the side walls form an entrance face, which may be provided with a cutting profile. A typical grab includes two grab shells that are movably connected to a grab body to move between a closed position in which the entrance faces of the shells abut so that the shell spaces of the grab shells form a bucket for the material to be grabbed, and an open position of the grab in which the entrance faces of the grab shells are spaced apart and form an opening in between which material can be handled in and out of the shell spaces.

Grabs are typically subject to intensive use, and need to be extremely wear resistant. The metal sheet that is used for the grab shells is typically a wear resistant steel plate or e.g. about 8-15 mm thickness. This material is not easy to shape, and e.g. seaming parts to become curved into two planes easily introduced tears, cracks or stress concentrations. Grab shells have therefore traditionally been formed by welding the side walls as flat parallel plates at right angles to a bottom plate that is are in a single plane.

A disadvantage of this configuration is that the edges of the grab shells are relatively sharp, in particular in the corners or the entrance face. This may cause damage to the hold of the bulk material. Also, the sharp edges lead to stress concentration, and due to the dynamic loading forces or the grab thus to accelerated wear. Further, the right angles can cause bulk material to stick to the grab shell at the corners, which can lead to spillage when built up material releases from the corners.

To alleviate this disadvantage, it has been proposed to provide a triangular intermediate plate in the corners of the entrance face, also known as cone plate. Although such a cone plate that is good between the sheet metal or bottom and the side walls provides the U-shaped entrance face with less sharp corners, it causes compression or bulk material at the apex or the triangle where it meets the bottom and sidewalls, which increases wear.

The present invention aims to improve a grab shell, in particular with respect to the efficiency of the grab shell construction and / or its operational characteristics.

Thereto the invention provides for a grab shell, including a are bottom of which two opposing edges are each provided with a side wall, which bottom and side walls include sheet metal with which is a shell space is formed for holding material to be grabbed, and sheet metal or at least one side wall connects to sheet metal or the bottom via a are edge portion in the sheet metal or the side wall.

The bent edge portion is preferably in a single plane, and may be in particular line, e.g. using a brake press. The bent edge may include a single bend, but may also include a number of successive bends. The bending radius of each bend is preferably less than 150 mm, more preferably less than 100 mm. The bending radius of each bend is preferably at least the thickness of the sheet, but is more preferably at least 4 or 5 times the thickness of the sheet.

In other words, the side wall may be provided with a flap that is integral with the side wall, and that can extend with a substantial transverse component to a body or the side wall to connect with the edge or to the edge or the bottom . The edge of the edge portion and the edge of the bottom may be welded together via a single weld line, which facilitates manufacture. The weld line may include segments that are curved in two planes.

Within the context of this disclosure, kinks are line bends or folds in the sheet metal along a relatively sharply defined fold line, and may typically be provided using a brake press. The bending radius of a kink is within the context of this disclosure is less than 150 mm, in particular less than 100 mm. This as opposed to curves in the sheet metal, which have a more gradual bending zone that is significantly larger than 150 mm, e.g.

200 mm or more, which is obtained using a roll bending or streaming machine. The bent edge portion may contain several successive, parallel kinks.

The side wall need not be along the entire length or the edge that connects to the bottom, and may e.g. be only in the area leading up to the entrance face. The bent edge portion is for ease of manufacturing or preferably along a straight bending line. The bent edge advantageously comprises a variety of segments that are each along a straight bending line. The bending lines of the successive segments may then extend at an angle to each other, in particular at a blunt angle. This way, the edge portion may follow the curve or the bottom relatively closely. The side wall may be manufactured form a single piece of sheet metal, but may also be composed of several pieces of sheet metal that are e.g. The side wall may be cut from flat plate or sheet metal, which is then, in particular in a single plane, and preferably by line bending.

The bottom may be in a single plane. This facilitates manufacture. The bottom may be a varying curvature, and may in particular be provided with a curvature that increases in an entrance area that starts from the entrance face. This facilitates grabbing the material. The bottom may be a rough polygon, but preferably has a smooth curvature that is provided by roll bending. The bottom may be manufactured form a single piece of sheet metal, but may also be composed of several pieces of sheet metal that are e.g. The bottom may be cut from flat plate or sheet of metal, which is then bent, preferably roll in a single plane with a varying curvature.

During manufacture, the side edges of the sidewalls are connected, in particular by welding, to the opposing edges of the are bottom so that the sidewalls extend with their main bodies in planes that are substantially perpendicular to the bottom. A free edge of the bottom and adjoining free edges of the side walls form an entrance face, and may be provided with a cutting profile.

The bent edge portions connect substantially obliquely to the bottom. In other words, the edge portions connect to the bottom with a significant transverse component in the connection path towards the bottom. The edge portion may e.g. be in a single bend to extend at a sharp angle with respect to the plane or the body portion of the side wall, e.g. a sharp angle in the range of 20-80 °, e, g. 30 °, 45 ° or 60 °. The edge portion may itself form a flat planar flap. The bent edge portion may also include further, parallel successive bends, e.g., stepwise increase the angle of its extension with respect to the plane or the body portion. The edge portion may then be polygonal. The bent edge portion be even be in a single plane to extend curvedly or substantially curvedly to the bottom.

To facilitate manufacture, the sheet metal or the edge portion may, prior to bending, be cut so that it becomes segmented and includes cutouts between side edges of the segments. The cuts may extend from the edge or the edge portion to the bending line. After bending, the side edges or the cutouts may then be connected, e.g. welded. Consecutive segments may then include a blunt angle at connected side edges.

The bent edge portion of the side wall may include a scalloped edge, in particular at the edge of the segments. Such scalloped edge may be provided when cutting the edge or the side wall from the flat plate or sheet of metal. The scalloped edge may have a varying radius, to match a varying curvature of the bottom. The opposing edges or the bottom to which the sidewalls are connected to may, during cutting provided with a negatively scalloped edge that matches the scallops or the are edge portion. The data for cutting the cutting profile may be obtained through 3D CADCAM design software.

The invention further relates to a grab, including at least two grab shells that are movably connected to a grab body to move between a closed position in which the entrance faces of the shells abut so that the shell spaces of the grab shells form a bucket for the material to be grabbed, and an open position of the grab in which the entrance faces of the grab shells are spaced apart and form an opening in between which material to be handled can pass in and out of the shell spaces. The grab body may include pivoting livers on which the grab shells are mounted, e.g., in a case of a scissors grab, or may include a frame to which they are mounted via pivots, e.g., in a case or a clamshell grab. The grab may be used on e.g. a boom or crane via operating cables, e.g. hoisting cables and opening and closing cables or bars that are connected to the shells and / or other parts or the grab via connection points.

The invention also relates to a method of manufacturing a grab shell, in which sheet is metal or a side wall for the grab shell is, in particular line-to provide it with a are edge portion, and in which the edge of the edge portion is connected to sheet metal or a are bottom.

Regarding the extent of this disclosure it should be noted that the technical features described above may each be its own be embodied in a grab shell or grab, isolated from the context in which it is described, separate from other features or in combination with only a number of features described in the context in which it is disclosed. Each of these features may be further combined with any other feature disclosed, in any combination.

The invention will be further elucidated on the basis of a nonlimitative exemplary embodiment represented in the drawings. In the drawings:

FIG. 1 shows a schematic perspective bottom view of a first embodiment or two grab shells in accordance with the invention in a closed position;

FIG. 2 shows a schematic front view of the grab shells or fig. 1;

FIG. 3 shows a schematic side view of the grab shells or fig. 1; and

FIG. 4 a schematic bottom view of the grab shells or fig. 1.

It should be noted that the figures are merely schematic representations of a preferred embodiment of the invention. In the figures, identical or corresponding parts are represented with the same reference numerals.

Referring to figs. 1-4, two grab shells 1 are shown that are movably connected to a grab body (not shown). The grab shells 1 are shown in a closed position in which entrance faces 2 of the grab shells 1 abut so that shell spaces 3 of the grab shells 1 form a bucket for the material to be grabbed. In use, the grab shells 1 may each rotate about a pivot 4 relative to a part of the grab frame so that the entrance faces 2 of the grab shells 1 move away from each other to an open position (not shown), in which the entrance faces 2 are spaced apart at the bottom, and form an opening there between through which material can be handled in and out of the shell spaces 3.

The grab shells 1 shown in this example may be used for a clamshell type grab. The body is not shown in this example, but may include a frame to which the grab shells 1 are connected via pivots 4 and bar connection points 5 as is conventional for a clamshell grab.

The grab shell 1 comprises a bent bottom 6. Two opposing edges 8 or the bottom 6 are each provided with a side wall 7. The bottom 6 and side walls are made of sheet metal, e.g. 12 mm wear resistant steel. A shell space 3 for holding material to be grabbed is formed with the bottom 6 and side walls 7. Sheet metal or at least one side wall 7 connects to sheet metal or the bottom 6 via a bent edge 9 in the sheet metal of the side wall

7.

The edge portion 9 is a line-bent flap that is integral with the side wall 7, and that via a kink extends obliquely at 45 ° with respect to the body of the side wall to connect with its edge 10 to the edge 8 of the bottom 6.

The edge 10 or the edge portion 9 and the edge 10 or the bottom 6 are welded together via a single weld line 11, which includes segments that are curved in two planes.

The kinked edge portion 9 comprises a variety of segments 12 that are each along a straight bending line L. The bending lines L of the successive segments 12 extend at a blunt angle B. The side wall 7 has in this example leg cut from a single flat plate or sheet metal. The sheet metal of the edge portion 9 has, prior to kinking, leg cut so that it became segmented by providing cutouts between side edges 13 of the segments 12. The cuts extend from the edge 10 of the edge portion 9 to the bending line L After kinking, the side edges 13 or the cutouts have been welded together. In the example, consecutive segments 12 include a blunt angle B at connected side edges 13.

In this example, the segments 12 have been provided with scalloped edges 14 when it was cut from the flat plate or sheet of metal. The scalloped edge 14 has a varying radius, to match a varying curvature of the bottom 6. The opposing edges 8 of the bottom 6 have, during cutting, leg provided with a negatively scalloped edge that matches the scallops 14 of the kinked edge portion 10 .

The bottom 6 has in this example bone cut form a single piece of flat sheet metal, and has bone roll in a single plane to have a continuous and varying curvature.

In this example, the kinked sidewalls have the right to opposing edges 8 of the bent bottom 6 so that the sidewalls 7 extend with their main bodies in planes that are substantially perpendicular to the bottom 6. A free edge 15 of the bottom 6 and adjoining free edges 16 of the side walls 7 form the entrance face, and have been provided with a cutting profile 17.

The line-bent flaps that are formed by the kinked segments of the edge portion allow the side walls of the grab shell to connect to the bottom substantially transversely over a relatively long portion of the edge as seen from the opening face, so that sharp edges may be prevented, pressure of the material to be handled may be distributed better, handling of the bulk material may be improved, and the construction has improved resistance to the dynamic loading that results from grabbing material. Due to the linebending or the flaps the sides of the grab shell are relatively easy to manufacture and connect to the bottom, while the bottom may be in a single plane only, and can still be smoothly curved. The polygonal shape of the edge portion presented by the blunt angles between subsequent kinked segments has minimal disturbance of handling.

The invention is not limited to the exemplary embodiment represented here, but includes many variations. For example, the exemplary embodiment discussions are a portion that is kinked, but it will be clear that other forms of bending, in particular line bending, may be used.

Further, the grab shell may be different shape or size than in this example, e.g., when intended for use with a scissors grab. In addition, the cooperating grab shells need not be identical, and more than two grab shells, e.g. three or four, may cooperate to form a bucket for the material to be handled. Further, the grab shell may e.g. be open at the top, closed or semi-open. Also, constructional details of the grab shell, such as any stiffeners, beams, levers, synchronizing wheels, sheaves, cable or beam connection points, pivots etc. may vary depending on the type and function of the grab. Such variations shall be clear to the skilled person and considered to fall within the scope of the invention as defined in the appended claims.

LIST OF REFERENCE SIGNS

1. Grab shell

2. Entrance face

3. Shell space

4. Pivot

5. Connection point

6. Bottom

7. Side wall

8. Opposing edges bottom

9. Edge portion

10. Edge or edge portion

11. Weld line

12. Segments

13. Side edges or segments

14. Scalloped edge

15. Free edge bottom

16. Free edge side wall

17. Cutting profile

L Bending line β Blunt angle

Claims (10)

Conclusions CLAIMS 1. Grabber shell, comprising a curved bottom, two opposite edges of which are each provided with a side wall, the bottom and side walls comprising sheet metal with which a shell space is formed for receiving material to be grasped, characterized in that 5 plate metal of at least one side wall connects to plate metal of the bottom via a curved edge part in the plate metal of the side wall. The grab shell according to claim 1, wherein the curved edge portion comprises one or more segments, each of which is curved along a straight line. 3. Gripper shell according to claim 2, wherein the sheet metal of the edge part comprises cut-outs between side edges of the segments. 4. Grabber shell according to claim one of claims 1-3, wherein the curved edge part of the side wall comprises a scallop edge, in particular at the edge of the segments. 5. Gripper shell according to claim 4, wherein the shell edge has a varying radius of curvature. 6. Grabber shell according to claim one of claims 1-5, wherein the curved edge part connects obliquely to the bottom A gripper shell according to any one of the preceding claims, wherein the edge of the edge part of the sheet metal of the at least one side wall 20 connects to the sheet metal of the bottom via a weld seam that comprises segments that are curved in two planes. A gripper shell according to any one of the preceding claims, wherein a free edge of the bottom and the adjacent free edges of the side walls form an access surface. 25 A gripper comprising at least two gripper shells according to any one of the preceding claims, which gripper shells are movably connected to a gripper body to move between a closed position in which the access surfaces of the gripper shells lie against each other so that the gripper shells form a container for the material to be gripped, and an open position of the gripper in which the access surfaces of the gripper shell 5 are spaced apart and form an opening between them through which bulk material to be treated can enter and leave the shell spaces. 10. Method for manufacturing a gripper shell, wherein sheet metal is bent from a side wall for the gripper shell, in particular line-bent, to provide it with a bent edge part, and 10 wherein the edge of the edge portion is connected to a curved bottom. 1/4