US928510A - Lifting-magnet. - Google Patents

Description

A. 0. EASTWOOD.

LIFTING MAGNET. APPLIUATION FILED AUG. 10', 1908.

928,51 0. Patented July 20, 1909.

2 SHEETS-SHEET 1.

AT ORN EY A. U. EASTWOOD.

- LIF'FING. MAGNET. APPLIOATION FILED AUG. 10, 1908.

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OF CLEVELAND, OHIO.

LIFTING-MAGN ET.

Specification of Letters Patent.

Patented July 20, 1909.

Application filed August 10, 1908. Serial No. 447,682.

To all whom it may concern:

Be it known that I, ARTHUR C. EASTWOOD, a citizen of the United States, residing at Cleveland, in the county of Cuyahoga and State of Ohio, have invented or discovered new and useful Improvements in Liftin Magnets, -of which the following is a speci :ation.

My invention relates to new and useful improvements in lifting magnets.

The objects of my invention are to'provide means whereby the magnetizing winding of the magnet may be more expeditiously and cheaply wound; whereby the assembled winding may be more readily and safely handled; and whereb when in place in the magnet case, the wint ing will be supported and protected in such a manner as to guard against the effects of the rough handling and exposure, to whichthc magnet will be subjected in service.

My invention applies particularly to lifting magnets in which the winding is of the so-called strap or ribbon form, that is, the conducting member of the winding is rectangular in cross section having a width considerably greater than its thickness. Certain features of my invention are, however, equally applicable to magnets in which the winding is made up of the ordinary forms of insulated wire. In a strap or ribbon winding it is desirable to form the winding of a number of coils, one above the other rather than of a. single coil of greater depth. This is true because insulatin material, such as asbestos, in the form (it a ribbon must be in the neighborhood of 10/1000 ofaninch in thickness to be commercially racticable. In order that the insulating ribbon may form a minimum proportion of the total winding space, it is necessary that the conducting ribbon be as thick as )ossible compared with the thickness of the insulating ribbon. With a conductor of given cross section, if the thickness is made large, the width In ust be made correspondingly smaller. Naturally a coil of large diameter wound u of narrow ribbons of copper and asbestos is very delicate and dillicult to handle, since it is very likely to dish out of shape by the slipping of one turn over another, which is very likely to ruin the coil, because the insulating ribbon may become torn or displaced so as to permit neighboring conducting turns to come into electrical contact thus establishing short circuits.

My invention provides means whereby'the several shallow coils which make up the winding are well supported during the process of winding and the subsequent handling of the coil prior to securing it within the frame of the lifting magnet.

My invention provides simple and reliable means for clamping the winding firmly in place soas to prevent it from either moving vertically or turning about its axis.

Referring to the accom nmying d 'awings, Figure 1 is a top plan vlew; Fig. 2, a side elevation partly in section of the winding of my improved magnet and the means for supporting the'winding; Fig. 3, a side elevation partly in section of a complete magnet; and Fig. 4, a bottom plan View of a portion of the magnet case with the winding and bottom-plates removed.

In these figures, A is an annular bottom plate preferably of brass, having its inner and outer peripheries provided with finished flanges a and (1 which are provided with screw holes a spaced closely together so that the bottom plate may form a water tight joint with finished shoulders on the lower face of the central core B and the outer pole O of the magnet case. The plate A is also provided with an upwardly projecting flange a which serves as a mandrel upon which the coilsarc wound.

I have shown four separate coils e, 6 e and c. In windin the coils the form or mandrel comprised y the bottom plate A with its flange a is first thoroughly insulated by means of the insulating plate a and the insulating sleeve a." which slips over, or may be wound upon, the flange a. The form may then be mounted upon a rotatable head stock, preferably so arranged that the plate A will be horizontal thereby better supporting the insulation and the coils in the process of winding. The first coil is then wound, being made up of alternate strips or ribbons of copper and insulation, such as asbestos. When the first coil is completelywound, its periphery is held by suitable clamps or binding wires (not shown). The insulating plate a is placed above the coil e and the secondcoil'c is similarly wound. The remaining coils c and e are also wound in a similar manner. Suitable connections, of course, being made between the end of one coil and the beginning' of the next so as to cause current to flow through the several coils-in series in a uniform direction. When the last coil e is wound a heavy insulating plate is laid upon it, this plate being provided with s ots through which pass the terminal connections a". Radial clamping straps s, s s and s are then placed over this top plate of insulation and are drawn down by means of bolts or screws d and (1 respectively, the screws 2' engaging with bosses at the upper end of the central flange a and the bolts d passing through suitable ,holes near the outer edge of the oottom plate A. The bodies of the bolts d are covered with'sleeves ofinsulating material d to' prevent the possible contact with the periphery of the winding. By means of these clamps the entire winding is clamped firmly against the bottom plate A before being handled, and the entire winding, therefore, becomes a unit held firmly together and may be moved about and assembled in the magnet case without danger of injury to the coils. After the winding is completed, an insulating layer a is bound around the exterior of the winding. The winding .is then preferably impregnated with a compound which will thoroughly Waterproof it. It is then assembled in the magnet case, the inner and outer flanges of the plate A being firmly screwed in'place to the lower faces of the inner and outer poles, as previously described.

As will be seen in Fig. 4, the inner and outer walls of the magnet case are provided with slots or notches s and s respectively to accommodate the ends of the straps s, 8 s, and s and the clamping screws and bolts Id and (Z which engage the ends of these straps. The upper surface of the winding space is likewise provided with grooves or slots 8, 8 etc., for accommodating the bodies of the straps s, 8 s and 8, these grooves havin greater depth for accommodating the heads of the bolts 03 andd This construction is adopted to secure minimum Wei ht of the completed magnet and also to ad to the efficiency of d1ssipating the heat developed within the magnetizing winding.

If the windin space were made large enough all around to accommodate the projecting ends of the clamping straps s, '8 s, and s and deep enough to receive the depth of the straps in addition to the depth of the Winding, the magnet would necessarily be considerably larger and heavier than a magnet in which my preferred construction 15 used; or, if the winding space bemade of the same general dimensions, the portion of the windmg space actually filled by the winding would be smaller, and less magnet izing force could be developed in the magnet. Further, the spaces between the surfaces of the winding and the magnet case would be increased thus interfering with the conduction of heat to the magnet case, from at their ends pockets of which the heat is finally dissipated. The outer or wearing plate D, which I preferably make of manganese steel is then put in lace, and the pole shoe 0 is bolted to the ower face of the outer pole C. This pole shoe has a shoulder or step 0 which engages with the periphery of the wearing plate D so as to support and assist in clamping the plate D in place. The pole shoe 0 is held in place by a series of bolts or studs 0 which have their nuts and threaded ends disposed between the ribs c whereby they are protected from abrasion. The center pole shoe 6' is then bolted in lace on the face of the central pole B. This pole shoe is provided with a shoulder or step b which engages and supports the central edge of the wearing plate D. The pole shoe 1) is held in place by studs or bolts 5 which pass through the core B, which is provided with a central opening 6* serving as a ventilating flue or duct through the magnet. The terminals 6 are then connected to the lower ends of studs g carried by an insulating plate These studs terminate in L-shaped plugs adapted to engage with removable female members g, which in turn are surrounded with insulating sleeves each having a central passage through which passes a flexible connecting wire g, connecting the s:-

windings of the magnetwith a source of current. After the terminals e are connected to the stnds'y and before the insulating plate 9 is screwed in place, the casing of the magnet is poured full of a sealing compound A: composed of an insulating material which softens under the influence of heat. The spaces between the surface of the winding and the frame of the magnet. are completely filled with insulating material .in this way. The insulating plate is then screwed in place, a gasket g being placed beneath it so as to form a Water-tight joint. Tl" top of the cavity in which the terminals are located is then closed by a steel plate 9 under which is placed packing g to effect a water-tight joint.

The walls L of the terminal spaces are preferably made very heavy and are cast inte gral with the frame of the magnet so that the terminalsmay be protected from the hard usage to which the completed magnet will necessarily be subjected when dangling from the end of a hoisting chain on a crane. The walls of the terminal cavity are also preferably brought up to a sufiicient height to cover and protect the heads of the studs or screws g, which clamp the cover plate. g in place. These upwardly extending walls I are provided with a ertures g to prevent Water accumulating mtho top of the terminal cavity above the plate 9".

It is noted that I have shown the pole shoe 0' of such dimensions that its active face will be lower than the active face of the central pole shoe 7). This is done so that the poles of the magnet may come into better engagement with the uneven surface of bulk material, such as pig iron. The depth of the pole ring (1 is also of advantage mechanically since the ring will be very strong in a vertical direction and therefore capable of withstanding the heavy blows which it receives when the completed magnet, which may readily weigh 5000 pounds, is dropped upon piles of iron and steel.

I claim 1. A lifting magnet frame having an annular space, a winding, a cylindrical internal support for the winding, a cap plate for the internal support, and means for sec u'ing the said support in the said annular space.

2. A lifting magnet having a winding, a winding support comprising a bottom plate, having a concentric shoulder 'extendin therefrom and serving as a support for sai winding, and means for clampin said winding firmly against said bottom p ate.

3. A lifting magnet having a top plate, a central core depending therefrom, an outer pole concentric with and s aced from said central core,a winding in t e space between said central core and said outer pole, a bottom plate arranged to support the winding and having a central flange secured to the lower face of said central pole, an outer flange secured to the lower face of said outer pole, and an upwardly projecting flange serving as a central support for sald windmg.

4. A lifting magnet having an annular winding space, a winding therein, a winding support comprising an annular bottom plate having annular inner and outerflanges engaging with the lower faces of the inner and outer walls of said winding space, and an upwardly projectin flange serving as a central sup ort for sai winding.

A ifting magnet having an annular winding space, a winding therein, means for supportin and clam ing said winding in place, said means inc udin a bottom plate having inner and outer flanges engaging with the faces of the inner and outer walls of said winding space, an upwardly projecting flange serving as a central su port for the winding, clamping means zliove the winding, screws or bolts for drawing said clamping means toward said bottom plate and clamping, the winding between the clamping means and the bottom plate, there being pockets in the walls of said winding space for accommodating said straps and said bolts or screws.

(3. A lifting magnet having an annular winding space, a winding therein, means for supporting and clam ing said winding in ilace, said means inc udmg a bottom plate having inner and outer i anges engaging with the faces of the inner and outer walls of said winding space, an upwardly projecting flange serving as a central support for the winding, clamping means a ove the winding, and screws or bolts for drawing said clamping means toward said bottom plate and clamping the winding between the clamping means and the bot-tom plate.

7. A lifting magnet having an annular winding space, a, winding therein, a bottom plate having inner and outer flanges clamped .to the lower faces of the inner and outer walls of said windin space,vand means independent of the walls of the windin space for clamping said winding against t e upper side of said bottom plate.

8. A lifting magnet frame having an annular windin r space, and an insertlble unit for said win ing space consisting of abottom plate, a central support, a winding composed of a plurality of coils wound one above the other around the central support and rigidly clamped to the bottom late extending radially outward from sai central support, said bottom plate having shoulders adapted to engage with the inner and outer walls of said winding space.

9. A lifting magnet havin an annular coil space, a magnetizing coi in said coil space, a spool upon which the coil is wound, the lower head of said spool engaging with the walls of the magnet near the 0 en end of the annular winding space ail being adapted to make a water tlght joint there- With'.

10. A lifting magnet having anannular winding s ace and a unit for said winding space sai for closing said win ing space and a windlIig clamped to the upper side of said bottom ate.

11. A lifting magnet having an annular winding space, a bottom plate, the inner and outer edges of which are screwed to the lower faces of the inner and outer walls of said windin space, a magnetizing windlng in said Win ing space, means for clamping said winding against the upper side of sa bottom late, a cover plate of non-magnetlc material covering-said bottom plate, and

ole shoes clamped to the lower faces of the inner and outer walls of said winding space, said pole shoes being adapted to clamp said cover plate in place. 0

12. A lifting magnet having a wlndmg space, a magnetizing winding in said space a non-magnetic bottom plate for closlng sa1 unit eomrising a bottom plate winding space, means independent of the said winding, and means independent of the walls of said'winding space for clamping said Winding to said support, there being recesses in the Walls of said winding space for accommodating said clamping means.

14. A lifting magnet having a central ipole, an outer pole concentric with and surrounding said central pole and removable pole shoes on the bottom faces-of both of 0 said poles, the pole shoe on the outer pole being deeper than the pole shoe on the central pole, such that its under face is lower than the under face of the'pole shoe on the central pole.

Signed at Cleveland, Ohio, this 1st day of Aug. 1908.

ARTHUR C. EASTWOOD. Witnesses i C. PIRTLE, H. M. DIEMER.

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