FIELD OF THE INVENTION

The present invention relates to a method and apparatus for controlling an electromagnetic lifting device comprised of electromagnetic coil arranged in housing and fixed in excavator boom, which can be operated by a plurality of electrical power sources.

BACKGROUND OF THE INVENTION

In magnetic lifting devices such as overhead cranes, installations are usually provided for supplying direct current to the magnetic coils of the lifting devices. Where alternating current is available, it is supplied through transformers and rectifiers, with suitable control means for supplying direct current to the magnetic coils.

Such an arrangement cannot be used with mobile cranes where they are not near an alternating current power source. In such situations, the current supply means must be carried on the lifting devices themselves. For this purpose, it is known to systems comprising an alternator or generator as current generator source. The alternating current generated by the alternator is converted by a transformer into the required voltage and this voltage is then conducted by rectifiers and protective devices to the magnetic coils of the lifting device.

Magnetic lifting machines have been in use for years. Conventional magnetic lifting machines are comprised of a crane structure with direct electrical power only.

The conventional magnet cannot be used in a scrap yard. In these respects, the excavator electro lifting magnet according to the present invention substantially departs from the conventional concepts and designs of the prior art

Objective of the Invention

It is a primary object of this invention to provide a Electromagnetic lifting device, which can be fixed or mounted on an excavator and power to the magnet is generated from alternator which is connected and driven by the engine shaft.

It is a further object of the invention to provide a magnetic lifting device which is simple in design, easy to use and reliable in operation.

Another object of the present invention is to provide a magnetic lifting system that will overcome the shortcomings of the prior art devices.

An additional object is to provide a magnetic lifting system that may be utilized upon various types of excavators.

A further object is to provide a magnetic lifting system that may be effectively utilized upon small to medium sized metal scrap operations, used in open yards and critical operating areas.

Another object is to provide a magnetic lifting system that is easily attached and removed from excavators.

This and other objects are accomplished according to the invention with a magnetic lifting device having a load lifting magnet comprised of at least one magnetic coil arranged in a housing, a driven synchronous alternator assembled in the excavator, for generating a voltage supplied to the control panel and then to the magnetic coil, for supplying direct voltage to the magnetic coil, an electrical switching circuit in the control panel with a control line arranged to operate the magnet either by remote means or by way of a switching circuit in control panel.

Description

The present invention relates to a lift adaptor for mounting an electromagnet to a lift crane boom. Electromagnets for lifting material have been known for many years. A lift chain assembly is commonly used to attach an electromagnet to the hook of an overhead crane. Generally, the lift chain assembly employs a master link having an eye through which a crane hook passes and having means for connecting thereto three suspension chains. The tops of the suspension chains are connected to the master link and the bottoms thereof are connected to the electromagnet so that the electromagnet can be raised and lowered by the crane. However, the suspension chains used, permit the electromagnet to swing freely, thereby reducing the effective control of the crane operator. Furthermore, suspension chains do not permit the crane operator to exert a compressive force through the electromagnet on material to be lifted. In addition, the suspension chains do not permit the crane operator to control the electromagnet by inclining or tilting the magnet.

Briefly, in accordance with the invention a mounting arrangement for an electromagnet is described and illustrated which overcomes the problems mentioned above and gives the crane operator complete control of the magnet in various positions, permitting the crane operator to incline or tilt the magnet The lift adaptor for an electromagnet of the present invention further permits the crane operator to operate the magnet more efficiently by preventing the magnet from swinging freely at the end of the lift crane boom. The lift adaptor for an electromagnet of the present invention also permits the crane operator to apply a compressive force to the electromagnet to compress the material to be picked up by the magnet. The ability of the crane operator to apply a compressive force to the electromagnet to compress the material to be picked up by the magnet is particularly important when the material to be picked up by the magnet is bulky and of low density. Compressing the material to be picked up permits the crane operator to operate the electromagnet more efficiently by picking up more material, and to load a truck or container more efficiently with higher density material. Furthermore, the ability of the crane operator to incline or tilt the electromagnet in accordance with the present invention permits the magnet to reach material from hard-to-reach corners or angles, thereby making the electromagnet much more effective.

Other advantages of the present invention will be apparent from the drawings, and the detailed description of the invention which follow.

The general purpose of the present invention, which will be described subsequently in greater detail, is to provide a new magnetic lifting system that has many of the advantages of the magnetic lifting devices mentioned above and many novel features that result in a new magnetic lifting system which is not anticipated, rendered obvious, suggested, or even implied by any of the prior art magnetic lifting devices, either alone or in any combination thereof.

To attain the present invention, is to attach the excavator electro lifting magnet mounted on the bottom of the boom of the excavator and an alternator mounted on the platform of the excavator above the engine shaft. The alternator is driven by the engine main shaft which connects through pulley and belt or geared sprocket and chain. The alternator is electrically connected to control panel, which is electrically connected to the electro lifting magnet

A control panel made up of CR metal sheet is fabricated with the required dimensions to be accommodated in the operator cabin of the Excavator. The fabricated control panel is chemically treated and coated with powder coating. Once the control panel is ready, the wiring circuit will be prepared by connecting high capacity industrial diodes corresponding to the load capacity and diameter of the magnet.
The Electromagnet is made of solid MS metal rolled by circular dimension and "I" Pole is mounted in the centre of the cylindrical shell and is then welded to top plate. The coil is wound on the bobbin of required diameter and insulated as per Class H.

The wound coils are placed inside the circular drum of l-Pole and insulated further so that it cannot get in contact with any metal parts. Then it is closed by welding Stainless Sheet metal sheet with SQ rod which comes in bottom side.

The terminal box is mounted at the top portion of the magnet so that the winding leads are crimped with lugs and connected to the brass bolt for external connection.

Once the terminal is made, quality checks are made and the terminal box is insulated and closed with SS sheet.

In this respect, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of the description and should not be regarded as limiting. These advantages are realized in the device as shown and described in the following figures:

Description of Drawings
Various other objects, features and attendant advantages of the present invention will become fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein:

FIG. 1 is a block diagram of an Excavator Electro Lifting Magnet

We Claim :

1. An Excavator Electro Lifting Magnet which consists of an Electromagnetic lifting device, which can be fixed or mounted on an excavator and power to the magnet is generated from alternator which is connected and driven by the engine shaft.

2. The invention as claimed in claim 1, wherein a magnetic lifting device is disclosed, that may be utilized upon various types of excavators and which is simple in design, easy to use and reliable in operation.

3. The invention as claimed in claim 1, wherein a magnetic lifting system is disclosed that may be effectively utilized upon small to medium sized metal scrap operations, all types of mild steel material, and also for loose and solid material, in open yards where no electrical source is there and in critical operating areas.

4. The invention as claimed in claim 1, wherein the Electromagnetic lifting device provides for a magnetic lifting system that is easily attachable and removable from excavators.

5. The invention as claimed in claim 1, wherein the Excavator Electro Lifting Magnet consists of

a. a magnetic lifting device having a load lifting magnet of any shape, comprised of at least one magnetic coil arranged in a housing,

b. a driven synchronous alternator assembled in excavator for generating a voltage supplied to the control panel and then to the magnetic coil, for supplying direct voltage to the magnetic coil,

c. an electrical switching circuit in the control panel with a control line arranged to operate the magnet either by remote means or by way of a switching circuit in control panel.

6. The invention as claimed in claim 5, wherein is disclosed a method and apparatus of controlling an electromagnetic lifting device comprised of electromagnetic coil arranged in housing and fixed in excavator boom, which can be operated by a genset mounted on the excavator or by a plurality of electrical power sources.

7. The invention as claimed in claim 5, wherein the excavator permits the crane operator to exert a compressive force through the electromagnet on loose scrap and steel turnings that are to be lifted, thereby improving the efficiency.

8. The invention as claimed in claim 5, wherein the Excavator Electro lifting magnet is powered through an alternator mounted on the platform of the excavator which is driven by the engine main shaft by connecting it through pulley and belt, or by means of a sprocket and chain mechanism or by means of gears.

9. The invention as claimed in claim 5, wherein the Excavator Electro lifting magnet permits the crane operator to incline or tilt the magnet to enable picking up of materials lying in corners and inaccessible areas.