DE1082680B - Permanent magnetic system for generating movements on a circular path - Google Patents

Description

GERMAN

In precision mechanics, for example in optical or photographic devices, are used for actuation certain elements often require rotary movements over a certain angular range. These movements are mostly carried out by hand, or by means of a stored spring force or with Help a permanent magnet, whose attraction force on a rotatable, by spring force in a ferromagnetic system held in rest position is regulated by adjusting a short-circuit element.

According to the invention, such rotary movements in one or the other direction of rotation are also carried out using a permanent magnetic system. It is from one to the generation linear movements known system structure made use of, in which two magnets with the same name Poles are arranged opposite one another in magnetic equilibrium with one another, and the equilibrium is disturbed by a piece of soft iron brought up to it, thus creating a linear movement the permanent magnets (which can also have a horseshoe shape) to cause each other.

Compared to the known systems of this type, the invention consists in that in the form of circular ring sections trained magnets are rotatably mounted about their center of curvature, while a piece of soft iron is movably arranged so that it is in the space between the poles of the same name Magnets can be moved into it, whereby the magnets perform movements on a circular path. A permanent magnetic system constructed in this way allows the generation of rotary movements, e.g. B. of adjusting elements, by simple linear movement of another adjusting element, whereby through the reporting A particularly easy adjustability of the individual parts against each other is guaranteed by springs.

Such a system according to the invention can e.g. B. in photographic lenses to open or Closing the diaphragm and / or for adjusting a depth of field indicator or the like. Can be used.

Should the control of a lens diaphragm be fully automatic depending on photoelectric If pulses are given by an appropriate exposure meter, the magnetic equilibrium position is established the magnets to each other by direct or indirect electrodynamic control of the Soft iron piece changed according to the incidence of light.

The drawing shows schematically some exemplary embodiments of the subject matter of the invention in various ways Movement processes.

Two in the form of circular ring sections, rotatable about their center of curvature Permanent magnetic system

to generate movements

on a circular path

Applicant:

Jos. Schneider & Co. Optical Works,
Bad Kreuznach (RhId.)

Heinz Schackert, Bad Kreuznach (RMd.),
has been named as the inventor

arranged permanent magnets α and b are bipolar magnetized so that the mutually facing ends of the same each have a north pole at c and a south pole at d . At these points, poles of the same name are opposite each other, so that a magnetic equilibrium is created by the repulsion acting on both sides. Applied, for example, to a photographic lens with automatic aperture control, this position corresponds to the parts of the largest aperture.

A one-sided disturbance of the magnetic equilibrium by introducing a piece of soft iron e into the force field causes the two magnetic pieces α and b to move simultaneously in the direction of the arrow towards this introduced piece of soft iron (Fig. 2). In the above example, this process corresponds to closing the aperture up to this value, which is determined by the preselection. In this arrangement, the opposite rotation of the two magnet segments α and b also allows a further adjustment process to be achieved automatically, e.g. B. a depth of field display by means known in optics or in photographic means (rotary pointer od. Like.).

If, on the other hand, only the movement of one of the magnets α or b is to be used, the other magnet is locked and the piece of soft iron e is brought directly to one of the stationary magnetic poles (Fig. 3).

The piece of soft iron e can be inserted either in the plane formed by the magnets (Fig. 4) or perpendicular to this plane (Fig. 5) in the space between the poles of the magnet system of the same name.

For the purpose of fully automatic control of a lens-appropriate means, also electrodynamically moved, the piece of soft iron e can be shown in Fig. 5

OTO 528 / MO

are, for example, as a function of photoelectric pulses from an appropriate exposure meter.

When the piece of soft iron is withdrawn from the space between the poles of the magnet system of the same name, one or both magnet segments α and / or b are moved back into the initial or rest position, which means that the adjusted parts also move back automatically without any spring force or the like.

Claims (4)

Claims: IO 1. Permanent magnetic system of two or more mutually movable bar magnets, each of which has two poles and is arranged so that the poles of the same name are at a greater distance from one another and are brought out of their equilibrium position by moving a piece of soft iron near the system, characterized in that, that the magnets (a and b) in the form of circular ring sections are rotatably mounted about their center of curvature, while a piece of soft iron (e) is movably arranged so that it enters the space between the poles of the same name the magnets can be moved in, whereby the magnets perform movements on a circular path. 2. Permanent magnetic system according to claim 1, characterized in that one of the magnets (a or b) is fixedly arranged and the piece of soft iron (e) is introduced directly to one of the fixed magnetic poles. 3. Permanent magnetic system according to claims 1 and 2, characterized in that the soft iron piece (e) is introduced into the space between the poles of the magnet system (a, b) in the plane formed by the magnets or perpendicular to this plane. 4. Use of a permanent magnetic system according to claims 1 to 3, in photographic Lenses and the like, for example to open or close the aperture and / or to Adjusting a depth of field indicator or the like. Considered publications:
German Patent Nos. 910096, 920392;
British Patent No. 592 568;
French patent specification No. 1117 941. 1 sheet of drawings © 009 528/240 5.