GB2184603A

GB2184603A - Magnetic load-shifting device

Info

Publication number: GB2184603A
Application number: GB08531752A
Authority: GB
Inventors: Josef Mach; Jan Hubalek
Original assignee: IMADOS INST MANIPULACNICH DOPR
Current assignee: IMADOS INST MANIPULACNICH DOPR
Priority date: 1985-12-24
Filing date: 1985-12-24
Publication date: 1987-06-24
Also published as: GB8531752D0; DE3545213A1; GB2184603B; DE3545213C2

Abstract

The device comprises permanent magnet blocks (2) which are mounted so as to be freely pivotable when required to carry a load (8) having a non-planar surface. As shown, the blocks (2) are movable by a hydraulic device (5, 6) via linkage (3, 4). Raising of the blocks causes the load (8) to abut a housing (1) and disengage from the blocks (2). <IMAGE>

Description

SPECIFICATION A Magnetic Unit The invention relates to a magnetic unit for handling ferromagnetic materials.

The use of permanent magnets for handling ferromagnetic materials is well known. When large sheets are to be handled, magnets having several magnetic units are used, each magnetically connecting with the sheet. Either the number or the size of these units must increase with the lifting capacity of the magnet. If the number of units is increased, difficulties may arise concerning the arrangement, control, monitoring and maintenance of a large number of individual units. If the size of the unit is increased, the area of contacting surface is increased which resuits in a less efficient utilisation of magnetic flux. A further disadvantage of a unit with a large contacting surface is that the surface of a large metal sheet may not be planar.

The surface may have considerable curvature which cannot be followed by the entire contacting surface of the unit. Thus the area of contact is reduced resulting in a reduction in the connecting force between the metal sheet and the unit.

An object of the invention is to eliminate these difficulties.

This is achieved according to the invention by the provision of a magnetic unit comprising a magnetic block having a plurality of separate parts, each part being arranged for independent orientation during magnetic connection with the load, such that loads having non-planar surfaces may be lifted.

The advantages of this arrangement are that each unit has a large total contacting surface with each part being small enough to allow efficient utilisation of magnetic flux; that each part is independently pivotable to allow good contact of the total contacting surface of the unit with a curved surface; and that each unit is controlled and monitored as a whole, thereby reducing the complexity of controlling and monitoring systems for a given number of parts.

The use of permanent magnets necessitates the provision of means whereby the load may be released from the magnet. This may be achieved preferably by the use of an abutment member which may be attached to or form part of a frame or housing. The parts carrying the load may be moved relative to the abutment member bringing the load into contact with the abutment member.

Further movement of the parts causes separation of the load from the magnet.

An embodiment of the invention will now be described with reference to the accompanying drawing, wherein Figure 1 is a diagrammatic sectional view of a magnetic unit carrying a load; and Figure 2 is a diagrammatic sectional view of the magnetic unit as the load is released.

The unit shown in the Figures 1 and 2 has a magnetic block divided into two parts 2. The parts 2 are pivotally suspended from bars 3 which are themselves pivotally connected to beams 4, thus allowing the bars 3 to remain vertical at all times while the parts 2 may be oriented in any direction.

The beams 4 are pivotally mounted on a frame or housing 1, such that rotation of the beams 4 causes upward movement of the bars 3 and thus the parts 2, relative to the frame 1. Rotation of the beams 4 is carried out by an hydraulic device 5, which forms a connecting element between the beams 4.

Introduction of hydraulic working fluid into the chamber 6 causes the beams 4 to rotate such that the parts 2 are raised; removal of hydraulic working fluid from chamber 6 causes rotation of the beams 4 in the opposite directions such that the parts 2 are lowered.

Connection between the parts 2 and the load 8 is made with the parts 2 in a lowered position.

Contact is only possible if the contacting surfaces of the parts 2 extend in a downward direction at least as far as the lowest extremities of the frame 1 when the parts 2 are in the lowered position. The load 8 is shown diagrammatically in the figures with a substantialiy planar surface although the curvature may be considerable. The parts 2 are able to pivot about the lower ends of the bars 3 as contact with the load 8 is made.

When the load 8 is required to be released, the beams 4 are rotated and the parts 2 are raised relative to the frame 1. The lowest extremities of the frame 1 form an abutment member against which the load 8 abuts before the parts 2 reach the fully raised position shown in Figure 2. In the fully raised position, an air gap 7 exists between the parts 2 and the load 8. The connecting force therebetween is thus greatly reduced and the weight of the load 8 causes it to fall away from the unit.

A magnetic unit having a larger total contacting surface area may comprise two lines of parts, each part in any one line being suspended from a single beam. Only one hydraulic device is then needed to rotate the beams and cause movement of all the parts. Other arrangements of parts and beams are possible.

1. A magnetic unit for lifting and releasing a load comprising a magnetic block having a plurality of separate parts, each part being arranged for independent orientation during magnetic connection with the load, such that loads having non-planar surfaces may be lifted.

2. A magnetic unit as claimed in claim 1, wherein the number of separate parts is two.

3. A magnetic unit as claimed in any one of the preceding claims, wherein the separate parts are each pivotally suspended from support means.

4. A magnetic unit as claimed in claim 3, wherein the support means are movable in an upwards direction relative to abutment means causing separation of the said parts from the load.

5. A magnetic unit as claimed in claim 4, wherein the support means are connected to actuating means for actuating movement of the support means in an upwards direction.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION A Magnetic Unit The invention relates to a magnetic unit for handling ferromagnetic materials. The use of permanent magnets for handling ferromagnetic materials is well known. When large sheets are to be handled, magnets having several magnetic units are used, each magnetically connecting with the sheet. Either the number or the size of these units must increase with the lifting capacity of the magnet. If the number of units is increased, difficulties may arise concerning the arrangement, control, monitoring and maintenance of a large number of individual units. If the size of the unit is increased, the area of contacting surface is increased which resuits in a less efficient utilisation of magnetic flux. A further disadvantage of a unit with a large contacting surface is that the surface of a large metal sheet may not be planar. The surface may have considerable curvature which cannot be followed by the entire contacting surface of the unit. Thus the area of contact is reduced resulting in a reduction in the connecting force between the metal sheet and the unit. An object of the invention is to eliminate these difficulties. This is achieved according to the invention by the provision of a magnetic unit comprising a magnetic block having a plurality of separate parts, each part being arranged for independent orientation during magnetic connection with the load, such that loads having non-planar surfaces may be lifted. The advantages of this arrangement are that each unit has a large total contacting surface with each part being small enough to allow efficient utilisation of magnetic flux; that each part is independently pivotable to allow good contact of the total contacting surface of the unit with a curved surface; and that each unit is controlled and monitored as a whole, thereby reducing the complexity of controlling and monitoring systems for a given number of parts. The use of permanent magnets necessitates the provision of means whereby the load may be released from the magnet. This may be achieved preferably by the use of an abutment member which may be attached to or form part of a frame or housing. The parts carrying the load may be moved relative to the abutment member bringing the load into contact with the abutment member. Further movement of the parts causes separation of the load from the magnet. An embodiment of the invention will now be described with reference to the accompanying drawing, wherein Figure 1 is a diagrammatic sectional view of a magnetic unit carrying a load; and Figure 2 is a diagrammatic sectional view of the magnetic unit as the load is released. The unit shown in the Figures 1 and 2 has a magnetic block divided into two parts 2. The parts 2 are pivotally suspended from bars 3 which are themselves pivotally connected to beams 4, thus allowing the bars 3 to remain vertical at all times while the parts 2 may be oriented in any direction. The beams 4 are pivotally mounted on a frame or housing 1, such that rotation of the beams 4 causes upward movement of the bars 3 and thus the parts 2, relative to the frame 1. Rotation of the beams 4 is carried out by an hydraulic device 5, which forms a connecting element between the beams 4. Introduction of hydraulic working fluid into the chamber 6 causes the beams 4 to rotate such that the parts 2 are raised; removal of hydraulic working fluid from chamber 6 causes rotation of the beams 4 in the opposite directions such that the parts 2 are lowered. Connection between the parts 2 and the load 8 is made with the parts 2 in a lowered position. Contact is only possible if the contacting surfaces of the parts 2 extend in a downward direction at least as far as the lowest extremities of the frame 1 when the parts 2 are in the lowered position. The load 8 is shown diagrammatically in the figures with a substantialiy planar surface although the curvature may be considerable. The parts 2 are able to pivot about the lower ends of the bars 3 as contact with the load 8 is made. When the load 8 is required to be released, the beams 4 are rotated and the parts 2 are raised relative to the frame 1. The lowest extremities of the frame 1 form an abutment member against which the load 8 abuts before the parts 2 reach the fully raised position shown in Figure 2. In the fully raised position, an air gap 7 exists between the parts 2 and the load 8. The connecting force therebetween is thus greatly reduced and the weight of the load 8 causes it to fall away from the unit. A magnetic unit having a larger total contacting surface area may comprise two lines of parts, each part in any one line being suspended from a single beam. Only one hydraulic device is then needed to rotate the beams and cause movement of all the parts. Other arrangements of parts and beams are possible. CLAIMS

6. A magnetic unit as claimed in claim 5, wherein the support means and actuating means are connected by linking beams pivotable about points fixed relative to the abutment means.

7. A magnetic unit as claimed in claim 5 or 6 wherein the actuating means comprise an hydraulic device.

8. A magnetic unit substantially as herein described with reference to the accompanying drawing.