US3419832A - Permanent magnet holding devices - Google Patents

Description

Dec. 31, 1968 M. BAERMANN 3,419,832

PERMANENT MAGNET HOLDING DEVICES Filed Sept. 28, 1966 Fig.2

mvsw-ron /MX MAM/{IAN United States Patent 3 419 832 PERMANENT MAGNE'l HOLDING DEVICES Max Baermann, 506 Bensberg-Wulfshof, Bezirk Cologne,

Germany Filed Sept. 28, 1966, Ser. No. 582,665 Claims priority, application (ifrmany, Oct. 2, 1965, B 63 63 1 Claim. 01. 335-285) ABSTRACT OF THE DISCLOSURE This invention relates to permanent magnet holding devices of bar shape for holding magnetically adhesive objects such as tools, working devices and the like, made of iron or steel.

Permanent magnetic holding bars are known in various constructions. One of the known 'holding bars consists of an elongated rectangular support provided with spacers and covered with a plate of isotropic or anisotropic permanent magnet rubber. The permanent magnet rubber plate is magnetized in the longitudinal direction with striptype poles.

Holding bars of such construction cannot provide high specific attractive powers so that they cannot be used for relatively heavy objects with a small adhesive surface. In order to increase the specific attractive power or holding force, it has already been proposed to provide such magnets with iron pole plates on their pole surfaces, which plates collect the lines of magnetic force and concentrate them on the holding surface.

Such holding systems, however, have no large longitudinal extension. If it is desired to produce holding bars having a relatively large longitudinal extension, this involves high costs for iron pole shoes and permanent magnet material because several such systems formed by permanent magnets and iron pole plates must be combined to form a bar. Due to these high costs, holding bars of this type are relatively expensive.

The present invention aims at obviating the foregoing disadvantages by providing a permanently magnetic holding bar having a simple design, which although possessing a high attractive power, presents only low production costs and can easily be made of any length necessary for the desired holding purposes.

To this end, the present invention consists in a permanent magnet holding device, particularly for holding tools, working devices and similar objects made of iron or steel which comprises at least two elongated U-shaped members of ferro magnetic material arranged one inside the other in spaced relationship, an elongated permanent magnet positioned between such bars or channels so that the one surface of such magnet having a north pole adheres to one of said bars or channels and the other surface of such magnet having a south pole adheres to the other of said bars or channels, the lengths of the legs of the U- shaped members being so dimensioned that their ends are situated in the same plane.

By virtue of this construction, it is possible to produce a permanent magnet holding bar of great length from which smaller lengths can be obtained by simply cutting the bar into desired lengths.

By using U-shaped members and by their particular arrangement with regard to the permanent magnet, the lines of magnetic force are guided to the ends of the legs of the bars and are strongly concentrated there so that in 3,419,832 Patented Dec. 31, 1968 spite of the simple design a high magentic attractive power is available.

Furthermore, the construction according to the invention renders it also possible to use a cheap permanent magnet material of relatively low remanence. Preferably, a flexible permanent magnet material, so-called magnetic rubber, is used which is composed of a mixture of a highly coercive powdered permanent magnet material such as Barium Ferrite and a flexible plastic binder, the binder being cured after the mixing so that it holds the particles of magnet material together.

Preferably, the permanent magnet is fastened between the U-shaped members by means of rivets. Alternatively, the magnet may be fastened to the U-shaped members by means of a suitable adhesive. The remaining space between the U-shaped members may be filled with any suitable filling material, such as a plastics material, cast resin, or the like.

The princiapl object of the invention is the provision of a novel permanent magnet holding device which has improved holding power and which may be cheaply manufactured.

Still another object of the invention, the provision of a novel improved magnet holding device which is made up of a pair of U-shaped members arranged one inside the other with a permanent magnet therebetween and having the ends of the legs thereof in a plane which will form a holding surface for ferro magnetic articles such as tools, working devices, and the like.

Still another object of the invention, the provision of a novel permanent magnet holding device which, in effect, has a plurality of permanent magnet holding surfaces.

In order that the invention may be more readily understood, reference is made to the accompanying drawings which illustrate diagrammatically and, by way of example, one embodiment thereof and in which:

FIG. 1 is a perspective view of the permanently magnetic holding bar; and

FIG. 2 is a section of theholding bar fastened to a wall with a tool held on it.

Referring now to the drawings wherein the showings are for the purposes of illustrating preferred embodiments of the invention only and not for the purposes of limiting same, FIG. 1 shows a permanent magnet holding device comprised of a pair of U-shaped members 1, 4 arranged with their bases and legs 3, 5 respectively and spaced from each other. An elongated permanent magnet 2 is positioned between the members, preferably between the bases of the two members 1, 4. The two members with the permanent magnet therebetween are fastened together by any suitable means but in the embodiment shown in the figures by means of tubular rivets 6.

The members 1, 4 are of a term magnetic material such as iron or steel, and their legs 3 and 5, taken in conjunction with the thickness of the permanent magnet 2, have a length such that the ends all lie in the same plane and form a holding surface for ferro magnetic objects to be held.

The permanent magnet 2 in the preferred embodiment is generally rectangular in cross-sectional shape and has an axis of magnetization perpendicular to and through the surfaces adjacent the bases of the U-shaped members 1, 4. While the poles N and S are shown only along the centerline of the surfaces, it will be understood that the entire surface of the permanent magnet 2 adjacent the bases of the U-shaped members 1, 4 exhibits a similar magnetic polarity.

The permanent magnet 2 may be made in any desired way but in the preferred embodiment is comprised of a mixture of Barium Ferrite and a flexible plastic binder. The binder is cured after the mixing so that it 'holds the particles of the magnet material together. The permanent magnet 2 may be manufactured as is shown in United States Patent No. 2,959,852 with the exception that the magnet poles instead of being on one surface only are on opposite parallel surfaces.

FIG. 2 shows the fastening of the holding bar onto a Wall. The tubular rivets 6 serve not only to connect the U-shaped members and the permanent magnet 2 in as sembled relationship but also at the same time receive the fastening screws for mounting the device on a wall. In FIG. 2 the permanent magnet 2 substantially fills the space between the two U-shaped members. If desired, and not shown, the remainder of the space may be filled with other non-magnetic material.

FIG. 2 also shows a tool 7 of ferro magnetic material held onto the holding surfaces formed by the ends of the legs 3 and 5.

The permanent magnet 2 is shown as having a width such as to only extend between the bases of the members 1, 4. Obviously the entire space or any portion thereof between the members 1, 4 can be filled with the perma nent magnet 2.

Obviously, more than two U-shaped members may be employed, e.g., three or four, with the ends of their legs in the same plane and with a permanent magnet 2 disposed between adjacent members and so polarized that the ends of the legs are of opposite magnetic polarity.

Thus it will be seen that a permanent magnet holding device has been described which accomplishes all the objects of the invention heretofore set forth and others and provides a magnetic holding device which is simple in construction, economical to manufacture, and which will have a maximum holding power for a minimum amount of magnetic material.

Having thus described my invention, I claim:

1. A permanent magnet holding device comprising a first elongated generally U-shaped ferromagnetic member having two spaced legs with elongated edge portions and an innner surface between said legs, a second elongated generally U-shaped ferromagnetic member having two spaced legs with elongated edge portions and an outer surface between said leg portions and facing away therefrom, a flexible permanent magnet strip secure-d between said inner and outer surfaces, said strip having a thickness sufficient to locate said edge portions in the same plane, said strip being formed from permanently magnetizable particles embedded within and bonded together by aflexible binder and said strip being permanently magnetized to have one pole abutting said inner surface and an opposite pole abutting said outer surface.

References Cited UNITED STATES PATENTS 2,959,832 11/1960 Baermann 335303 XR 3,304,527 2/1967 Marrs et al 335--285 GEORGE HARRIS, Primary Examiner.

U.S. Cl. X.R. 248206

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