Патент USA US2106233код для вставки
Jan. 25, 1938. I J, T_ BEECHLYILJ , 2,106,233 PORTABLE DEMAGNETIZER Filed Sept. 21, 1936 3 UZQWJ 52‘6 2 Sheets-Sheet l a "L 9 .81;/ x . 14 J3 @ ' 000 yfrm NJ»? 17 J9 J6 J0 UDO jg c/o?nZ' Beecklyza Jan. 25, 1938. .1. T. BEECHLYN 2,106,233 PORTABLE DEMAGNET I ZER Filgd Sept. 21', 1936 g\?-w-i \ 2 Sheets-Sheet 2 —~ -= 6 V& \\\ A, 15" I . 59. @f I ' jrldemdv" 2,106,233 Patented Jan. 25, 1938 UNITED STATES PATENT OFFICE ' 2,106,233 PORTABLE DEMAGNETIZER John T. Beechlyn, Worcester, Mass., assignor to 0. S. Walker 00. Inc. , Worcester, Mass, a cor poration of Massachusetts 7 Application September 21, 1936, Serial No. 101,773 10 Claims. The principal object of this invention is to pro vide improved means for demagnetizing articles of high carbon or alloy steels which, during their process of manufacture, have been held by mag 6 netic chucking. More speci?cally the objects of this invention are to provide a light weight portable device of this nature which will be powerful in action and can be manually applied to work that is too large 10 for convenient handling in relation to stationary means of demagnetization; to provide a cored device of this type having a strong external mag netic ?eld combined with means for obtaining a rolling engagement with the surface to be treated, 15 whereby the friction, ordinarily encountered with cored demagnetizers through magnetic attrac tion, is largely avoided; to provide a device cap able of good working engagement with a variety of surface contours, including cylinders and 20 cones, whether external or internal, such as for example larger roller bearing races; to provide an operating range of ?eld intensity wherein the gradient will not be abrupt, with the object of enhancing the allowable rate of passage of the 25 work, when the device is energized by alternating current of ordinary commercial frequency, and to provide a device that will be well adapted for use either as a stationary or portable demagnetizing means. Other objects and advantages of the invention will appear hereinafter. Reference is to be had to the accompanying drawings, in which Fig. 1 is a central sectional view of a demagne~ 35 tizer constructed in accordance with this inven~ tion; Fig. 2 is a bottom plan view of the same, partly broken away and in section; Fig. 3 is a longitudinal sectional view on the 40 line 3—3 of Fig. 2; Fig. 4 is an end view of the core body; Fig. 5 is a plan of the same; Fig. 6 is an end view of a modi?ed construction which comes within the scope of this invention, 45 shown partly in section, and Fig. 7 is an end view of the same. (Cl. 175-181) in a relative small pole area whereby the field outside the core is intensi?ed to an extent permit ting a space between the pole face and the work ing plane, the point of nearest approach being along a line in the center of the pole. This spac ing and a receding contour of the pole faces on each side of the nearest approach tend to pro duce an easy slope in the ?eld gradient, that permits complete demagnetization to be obtained with a relatively rapid passage of the work. A rolling engagement is provided which will, of course, greatly facilitate the operation. In Figs. 1 to 5, which represent a preferred form of the device, a laminated core body I is shown having the general form of a large segment of a cylinder. Two deep recesses extend longi tudinally in the core body whereby is formed a pole system of characteristic E type, with the tips of the poles 2 and 3, bounded by the seg mental arc. Disposed within the recesses and 20 surrounding the central pole is a suitable wind ing 4 designed for operation on alternating cur rent. The coil is secured in position by means of clips 5 which also serve for clamping together the laminations of the central pole by means of tie rods 6 extending longitudinally through perfora tions in the laminations. Clamping of the laminations is obtained by two heading mem hers ‘I secured by ties 8. The clamping surfaces of the heading members are suitably recessed at 30 9 to accommodate the ends of the coil 4. The winding 4 is fed from a source of alternating cur rent through a ?exible cable 38. Each of the heading members 1 carries a shaft like cylindrical extension I B, coaxial with the seg mental arc of the core body I. Secured to the extreme ends of these extensions are frame mem bers l I which are provided with lugs l2 for arbi trarily securing the device to a bench or other suitable foundation. Each of the frame members also carries two lateral extensions 13 and between the two pairs of these are secured handles H in. a position preferably parallel with the axis of the core body. On the extensions Ill are rotatably mounted two roller heads [5. These are provided with a suit In demagnetizers of the cored type it has been customary to employ ?at pole plates of con able bearing lining it, preferably of the wooden siderable area terminated abruptly in the work two heads are ?tted to receive the ends of a ing plane, the work being placed directly on the plate and withdrawn by a sliding action gener~ ally with considerable manual effort. It is evident that such a type of device is not well suited for easy demagnetization. In the present device the flux is concentrated oil-less type. At their outer circumference the cylindrical shell H‘, which has a length somewhat 50 greater than the core body I. This cylinder to gether with its heads completely surrounds the magnetic element and serves at once to provide a rolling engagement with the surface of work passed across the device over the pole 2. Also 55 2 2,106,233 they provide an effective seal against the en trance of ferrous matter into the coil and core through magnetic attraction. til To prevent excessive eddy currents from aris ing by the passage of the alternating ?ux through the shell, the latter may be made from dielectric material, but, with consideration to strength, it has been found desirable to employ a metal hav ing high electrical resistivity, such as can be it) obtained with certain manganese or nickel alloys. In the form shown in Figs. 1 to 5 the shell is not directly secured to the roller heads but is kept in seated engagement on these through the action of leaf springs 18. These springs are affixed to the frame members H and exert a moderate axial pressure on thrust rings IS. The latter are thus urged from opposite sides against the bearing linings of the roller heads and there by maintain the seated arrangement of the shell edges of which bear lightly against the roller throughout its length and thus produce a strip ping action. The advantages and mode of op eration with this form are in general similar to the device described in connection with Figs. 1 to 5. Having thus described my invention and the advantages thereof I do not wish to be limited to the details herein disclosed, otherwise than as set forth in the claims, but what I claim 1S! 10 1. In a device for removing residual magnet ism, a laminated core, a pole on said core, the outer end of the pole having the contour of a cylindrical arc with the axis of the arc substan tially at right angles to the laminating plane, and 15 a winding on said pole for producing an alter nating magnetic ?eld beyond the outer end of the pole, said pole contour being adapted to be brought into close proximity with the surface IT. This arrangement has been found a conven ient method of construction and assembly and it to be demagnetized. 20 2. In a device for removing residual magnet also provides a certain amount of resiliency in cases where heavy work pieces are brought vio ism, a laminated core, a pole on said core, the lently into contact with the cylinder 11. 25 With any method for demagnetizing materials having high magnetic retentivity the e?ectiveness of the operation depends on an adequate degree of initial penetration by an alternating magnetic ?eld and on the rate of subsidence of this pene tration, i. e., with a material of given charac teristics the decrement in induction in each of outer end of the pole having the contour of a cylindrical arc, and a winding on said pole for producing an alternating magnetic ?eld beyond the outer end of the pole, said pole contour be ing adapted to be brought into close proximity with the surface to be demagnetized. 3. In a device for removing residual mag netism, a source of alternating current, means ‘ connected with said source for producing an al successive cycles, from that of the immediately ternating magnetic flux, a relatively rotatable preceding cycle, must not exceed a certain critical shell surrounding the flux producing means, said value. From which it follows that the period of stepping down must embrace, at least, a certain number of cycles. The stepping down is usually e?ected by grad ually withdrawing the object from an intense portion of the ?eld rather than by diminishing the ?eld itself. With a given frequency of alter nation an abrupt intensity gradient in the ?eld will therefore necessitate a slower Withdrawal of the object. Conversely, an extended and uni form gradient, such as I employ, will permit a relatively rapid passage of the object. When the device is used as a portable tool it is manipulated by the handles, ordinarily in a po sition inverted from that shown in the drawings and simply rolled over the surface to be treated. The use of the demagnetizer in its portable form permits a new procedure. The device can be ap plied directly to the article to be demagnetized, before it is removed from a magnetic chuck, thereby avoiding a second handling of the arti cle. In the case of hardened steel it will entirely release its adherence to the chuck and thereby avoid the difficulty ordinarily experienced in de taching such articles. A modified form of the device is shown in Figs. 60 6 and 7. In this form the E type core 20 is en closed in a relatively stationary casting 2|, suit ably equipped with handles and lugs for fasten ing. The end pro?le of the central pole 22 is that of a concave cylinder surface. Coaxial with shell being adapted to furnish rolling contact with the surface from which residual magnetism ‘ is to be removed, and a means whereby a portion of the flux will traverse the shell. 4. In a device for removing residual mag netism, a laminated core, a winding on the core for producing an alternating magnetic circuit with a portion of the circuit external to the core, a relatively rotatable shell formed in a surface of revolution surrounding said core, and means whereby a portion of the demagnetizlng circuit will traverse a region outside the shell. 5. In a device for removing residual mag netism adapted for contacting engagement with the surface from which residual magnetism is to be removed, a laminated core, a pole on said core for producing a region of magnetic intensity 50 in the contacting plane and a relatively rotat able cylinder between the pole and the plane of contact, rotation being imparted to said cylinder by relative motion of the demagnetizer and the surface treated. 6. A demagnetizer comprising a magnetic core, U1 Di a cylindrical extension a?ixed to each end of the core, a rotatable ?ange on each extension, at cy lindrical shell seated at each end on one of said ?anges and surrounding the core, and resilient means for pressing the ?anges toward the core, whereby the shell is retained in seated engage ment with said ?anges. '7. A device for removing residual magnetism this surface is a laminated cylindrical roller 25 made from magnetic material and rotatably sup ported a slight distance from the pole by suit able bearings 23 secured to the core. Surround ing the pole and a portion of the roller is the en ergizing winding 24. A portion of the roller 26 furthest from the core 20 protrudes through an opening in the casing 2| and is tangent with the working plane of the device. In order to prevent entrance of foreign matter into the device the in said core partially external to the core, a rela— tively rotatable shell formed in a surface of revo lution surrounding said core, and a means where by a portion of the ?ux will traverse a region casing is equipped with leaf springs 25, the outer said core, the outer end of the pole having the 75 comprising a laminated core, a winding on said core, a source of alternating current connected with said winding to produce an alternating ?ux outside the shell. 8. In a device for removing residual mag netism, a laminated core, a pole integral with 3 2,106,233 contour of a cylindrical arc, a winding on the core to produce an alternating magnetic flux in said core and beyond the end of said pole, a rela tively rotatable shell surrounding said core and winding, and means whereby a portion of the flux will traverse a region outside the shell. 9. In a device for removing residual magnetism adapted for contacting engagement with the sur face to be demagnetized, the combination or a 10 laminated core, a pole on said core for produc ing a region of magnetic intensity in the con tacting plane, the face of said pole being of cy lindrical contour, and a relatively rotatable cyl inder between the pole and the plane of contact, said cylinder being substantially coaxial with said pole contour. 10. A portable device for removing residual magnetism adapted to contact with the surface to be demagnetized, comprising means for pro ducing an alternating ?ux, a frame affixed to said ?ux producing means, a roller rotatably mounted on said frame and adapted to furnish said con tact with said surface, and handles attached to said frame for moving the device in rolling en gagement with said surface. JOHN T. BEECI-ILYN.