GB2054274A

GB2054274A - Magnetically mountable clock

Info

Publication number: GB2054274A
Application number: GB8022149A
Authority: GB
Original assignee: Mannesmann VDO AG
Current assignee: Mannesmann VDO AG
Priority date: 1979-07-20
Filing date: 1980-07-07
Publication date: 1981-02-11
Also published as: FR2461970A1; IT1131591B; DE2929372A1; IT8023469A0; JPS5631674A; DE2929372C2

Abstract

A part-spherical ferro-magnetic rear portion (5) of the casing (2) of a clock body (1) is swivellably seatable in a cup shaped housing (6) where it can be held in any position by a magnet system (22-25) located therein. The ferro-magnetic portion (5) shields the clockwork from the magnet (22). The housing (6) may be secured mechanically (e.g. by nailing or gluing) or magnetically to an external surface, or mounted detachably on a spring peg (7) by which the clock assembly can be clamped to any suitable object. <IMAGE>

Description

SPECIFICATION Magnetically mountable clock The present invention relates to a clock which can be mounted in a housing so as to be movable therein to face in different directions.

A clock has been proposed in German Utility Model No. 74.39428 whereof the rear part of the casing is spherical and rests in a cup-shaped housing. The housing and the clock casing are connected by means of a screw which passes through an elongate slot in the housing and terminates in a corresponding threaded bore in the casing. When the screw is loosened it can be slid along the slot so that the clock pivots through up to approximately 45 degrees relative to the housing, and is then locked in the new position by tightening the screw. Such a clock has the disadvantage that a change in the position of the clock in the mounting is not possible without the assistance of a tool, namely a screwdriver. Furthermore the range of positions available is restricted to the course of the slot, so that the position of the clock in the mounting can only be varied within a single plane.

Clocks are also proposed (in German laidopen patent application 15.23832) which contain a permanent magnet so that the clock can be attached to a ferro-magnetic surface without additional attachment means. Apart from the fact that the orientation of the clock then depends on that of the ferro-magnetic surface, i.e., the angle of the clock cannot be varied relative thereto, such clocks have the disadvantage that the magnet present in the clock requires special shielding from the clockwork, in order to ensure that the magnetic field does not seriously impair the running precision of the clock.

According to the invention, there is provided a clock comprising a clock body which comprises a casing accommodating the clock mechanism and time indicating means, the casing or at least a rear portion thereof remote from the time indicating means, having a form which generally defines a sphere, said casing or at least said rear portion thereof comprising a ferro-magnetic material and a generally cupshaped housing which provides a seating in which said spherical casing or casing portion is swivellably mountable, and a permanent magnet system mounted in or adjacent the housing so as to tend to hold the casing mounted in said seating. With suitable embodiments of the invention, the housing and the clock body can be brought into the widest variety of relative positions, so that the clock can be brought into an easily readable service position in every conceivable position of the housing.Furthermore the measures necessary to achieve this aim can be cheap and lead to a simple construction of the clock, favourable from the production standpoint.

By having the permanent magnet system outside the clock casing, and making that part of the clock casing confronting the permanent magnet system from a ferromagnetic material, all or the greater part of the magnetic field lines generated by the permanent magnet system adjacent to the casing are directed through the ferro-magetic material, so that little or, preferably, no magnetic field is produced in the interior of the casing by the permanent magnet, which can thus exert substantially no influence upon the running precision of the clock. No more extensive shielding of the clockwork is necessary. By means of the magnetic connection of casing and housing and the constructional forms of the casing and the housing, the casing can be pivoted into any desired position in the housing and can be retained securely therein.

According to an advantageous embodiment of the invention the permanent magnet system is constituted by two or more permanent magnets arranged on a circle concentric with the axis of the cup defined by the housing.

Such an embodiment has the advantage that it can be constructed using cheap miniature magnets. However a more favourable embodiment for production engineering is one in which the permanent magnet system comprises an annular multi-pole permanent magnet. This is, however, generally somewhat more expensive than the aforementioned miniature magnets.

In a preferred embodiment of the invention the permanent magnet system includes a return plate for the magnetic field of the permanent magnet or magnets. By this measure the magnetic field in the interior of the casing can be further reduced, or the extent (total surface) of the ferro-magnetic material can be reduced for a given maximum acceptable magnetic field in the casing interior. The latter is of importance particularly when the spherical part of the casing does not consist totally of a ferro-magnetic material, but e.g., of a spherical plastics shell into or onto which the ferro-magnetic shell is applied, i.e., the spherical part of the casing is of two-layered construction. Such a construction will be chosen particularly where it is important that the clock should be of low weight.

It has been found convenient to provide a permanent magnet system which can attract the clock body with a force which is greater than the weight of the clock. This makes it possible to attach the clock to a surface at an angle such that the body is magnetically 'hanging' from the housing.

According to an advantageous embodiment the housing may be integral with, or may more preferably be detachably connected with a mounting means. In such an embodiment, in which housing and mounting means are detachable and the permanent magnet system is located in the housing, the housing may be constructed and arranged so as to be attachable to a suitable object or surface without the mounting means, e.g. by means of pins or screws and/or by means of an adhesive. It is also possible to construct the permanent magnet system so that the housing is magnetically attachable to a ferro-magnetic surface. In such a case, therefore, the permanent magnet system effects not only the attachment of the spherical clock casing to the housing but also the attachment of the housing to a ferromagnetic surface, e.g., a sheet metal wall.

A further increase in the usefulness of the clock, particularly with regard to readability in many mounting locations, is achieved according to a further idea of the invention in that it can comprise mounting means comprising a peg or spring clip with two relatively movable clamp jaws.

Such a mounting means, and the use of a clock casing retained pivotably in the housing, permits the use of the clock not only standing on a supporting surface but also mounted on any edges, frames, bars, posts and other objects to which the peg or clip can be attached.

According to an advantageous embodiment the peg or clip has two resilient clamp jaws oriented approximately axially parallel to one another. Such an embodiment is particularly simple for production engineering and is cheap to produce. It is somewhat disadvantageous that the range of use of the peg or clip tends to be restricted by the comparatively small spreading range of the two jaws to objects of a specific thickness range. This disadvantage is ameliorated in another advantageous embodiment, wherein the peg has two spring loaded arms which are rotatable about a common axis and each of which has a clamp jaw at one end and a handle at the other. This is however less favourable from the production standpoint than that previously described, since it consists of three components which have to be attached to each other.

It has been found convenient to construct one of the clamp jaws of the peg for detachable attachment to the housing, which may thus be used optionally with or without the peg.

A preferred embodiment of the invention will now be described with reference to the accompanying partly schematic drawing, in which: Figure 1 shows a partly sectioned side elevation of a clock with a housing and a mounting; Figure 2 shows a plan of the housing shown in Fig. 1; and Figure 3 shows a side elevation of a clock with a housing attached to a wall.

As seen in Fig. 1, a clock body 1 has a twopart casing 2, in which a clock mechanism 3 and an electric battery 4 to drive the clock mechanism are located. A rear part 5 of the casing, which is remote from the time indicating means, is hemispherical. The rear part 5 consists totally of a ferro-magnetic material, e.g., soft iron, which may be e.g., chromium plated on its outside for appearances sake.

The front part of the casing and the hemispherical part 5 may be mutually connected by means of a screw or snap connection.

The casing 2 of the clock body 1 rests with its hemispherical part 5 in a housing 6 with a mounting means 7, which has the form of a spring peg 8. The peg 8 has two clamp arms 10 and 11 which are rotatable about a common pivot 9, and each of which has a respective handle 1 2 at one end. At their other ends, the two clamp arms are jaws, and provided with rubber bosses 1 3 to improve the grip of the peg on an object. The two clamp arms 10 and 11 are tensioned by means of a helical spring 14, the two ends of which are secured each in one of the two clamp arms 10 and 11, so that the jaws carrying the bosses 1 3 are urged together.

The two-clamp arms 10 and 11 are braced against the spring 14 by means of lugs 1 5 and 1 6 which may be formed integrally therewith. Such a construction has the advantage that no additional pivot shaft is required for the two clamp arms 10 and 11.

A circular projection 1 7 with a radially projecting edge 1 8 is provided on the outer side of the clamp arm 1 0. The housing 6 can be snapped onto said projection 1 7. For this purpose the housing 6 is provided at its end remote from the clock with an annular lug 1 9 with radially inward lip defining an annular cavity 20.

In the housing 6, which is generally cupshaped, is located the permanent magnet system 21, which is constituted by a permanent annular multi-pole magnet 22 and a pole piece or return plate 23. The ring magnet 22 is axially magnetized so as to have a number of poles which are distributed alternately and uniformly upon the circumference of the magnet, as may been seen more particularly from Fig. 2. The return plate comprises an approximately circular base part 24 and a plurality of fingers 25 extending substantially at rightangles therefrom. The free ends of the fingers 25 are angled at their free ends so as to form a support for the hemispherical part 5 of the housing 2 (see Fig. 1). The angled ends of the fingers 25 lie against the top rim of the cupshaped housing 6. The return plate 23 and the magnet 22 are connected to the housing 6 by means of a hollow rivet 26.

As shown in Fig. 3, the use of an annular permanent magnet attached to the housing 6 by means of a hollow rivet 26, together with the detachable mounting of the housing 6 on the peg 8 makes it possible to attach the housing directly e.g. to a wall 27 by means of a screw 28 which can be driven into the wall 27 through the hollow rivet 26.

If the rear surface 29 (Fig. 3) of the housing 6 is provided with an adhesive layer, then the housing 6 may be stuck to smooth objects, e.g., a cupboard wall.

A particularly advantageous form of the invention is achieved if a plurality 5 of housings and mounting means are provided fixed, e.g., in different living rooms of a residence.

The clock body can then be removed from a housing in one room and placed on the housing present in the other room without having to detach any mounting means or housings.

Claims

1. A clock comprising a clock body which comprises a casing accommodating the clock mechanism and time indicating means, the casing or at least a rear portion thereof remote from the time indicating means having a form which generally defines a sphere, said casing or at least said rear portion thereof, comprising a ferro-magnetic material and a generally cup-shaped housing which provides a seating in which said spherical casing or casing portion is swivellably mountable, and a permanent magnet system mounted in or adjacent the housing so as to tend to hold the casing mounted in said seating.

2. A clock according to Claim 1 in which the permanent magnet system comprises two or more permanent magnets arranged in a circle concentric with the axis of the seating provided by said housing.

3. A clock according to Claim 1 or 2 wherein the permanent magnet system comprises an annular multipole permanent magnet.

4. A clock according to any one of Claims 1 to 3 wherein the permanent magnet system includes a return plate for the magnetic field of the permanent magnet or magnets.

5. A clock according to any one of Claims 1 to 4 wherein the permanent magnet system can attract the clock body with a force which is greater than the weight of the clock body.

6. A clock according to any one of Claims 1 to 5 wherein the permanent magnet system is constructed and arranged so that the housing is magnetically securable to a ferro-magnetic external surface.

7. A clock according to any one of Claims 1 to 6 wherein the housing bears mounting means for mounting the clock on an external object or surface.

8. A clock according to Claim 7, wherein the permanent magnet system is in the housing, and the mounting means is connected detachably to the housing.

9. A clock according to Claim 8, wherein said mounting on an external object or surface is effectable by means of one or more screws or nails, and/or by means of an adhesive.

1 0. A clock according to any one of Claims 7 to 9 wherein said mounting means comprises a peg with two relatively movable clamp jaws.

11. A clock according to Claim 10, wherein said peg comprises means for the detachable attachment of the housing thereto.

1 2. A clock according to Claim 10 or 11 wherein the clamp jaws of the peg are resiliently urged together.

1 3. A clock according to any one of Claims 10 to 12, wherein said peg comprises two spring loaded clamp arms rotatable about a common pivot each of which has a jaw at one end and a handle at the other.

14. A clock constructed and arranged substantially as described herein with reference to and as illustrated in the accompanying drawings.