GB2296068A

GB2296068A - Magnetic vibration isolator

Info

Publication number: GB2296068A
Application number: GB9425449A
Authority: GB
Inventors: John Jeffries
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-12-16
Filing date: 1994-12-16
Publication date: 1996-06-19
Also published as: GB9425449D0

Abstract

The vibration isolator (1) comprises first and second ring magnet assemblies (7, 8). The upper ring magnet assembly (7) is freely suspended above the lower ring magnets assembly (8) because the two magnets (2, 3) in the respective assemblies repel each other. The two assemblies are placed in a housing (10). The housing is placed on a floor or surface which may be a source of external vibrations. An object supported by the upper ring magnet assembly is isolated from external vibrations because there is no physical contact between the two ring magnet assemblies The object may be an LP record turntable, CD player in a car, PC on a train or any hi-fi equipment. <IMAGE>

Description

MAGNETIC VIBRATION ISOLATOR This invention relates to a device for isolating a supported device from external vibration.

It is very often an advantage for devices and equipment to be isolated from external vibration. Typical examples, are LP record turntables, CD players in cars, and PC's on trains and all Hi-Fi equipment.

Conventionally, such equipment has been isolated from vibration using various different methods such as laminated sandwiches of different materials such as wood, foam rubber, carpet felt etc. upon which the turntable is supported to suppress the vibration. Other devices use rubber pads which absorb external vibrations so that they protect the equipment supported on the rubber pads from most of the external vibration.

The problem with these known methods is that, because they are in contact with the equipment, they cannot totally exclude the transmission of the external vibration to the device.

According to the present invention, there is provided a vibration isolator for isolating an object from external vibration, the vibration isolator comprising a first magnet assembly, including a first magnet, arranged to be supported by a possible source of external vibration, and a second magnet assembly, including a second magnet, and configured to support the object, the two magnet assemblies being configured such that the two magnets repel each other, whereby the second magnet assembly is freely suspended above the first magnet assembly, with an air gap there between, so that external vibrations from the source are transmitted to the first magnet assembly but isolated from the second magnet assembly and the supported object. This has the advantage that very little of the external vibration is transmitted to the supported object.

The invention will now be described, by way of example only, with reference to the accompanying Figures, of which: Figure 1 is a schematic cross-section of a magnetic vibration isolator in accordance with the invention; and Figure 2 illustrates the isolator of Figure 1 supporting a Hi-Fi amplifier.

A vibration isolator 1 comprises a lower ring magnet assembly 7 comprising a first ring magnet 2 and an outer screening ring 3 which is typically made if mild steel. A second ring magnet assembly 8 comprises a second ring magnet 4, also with an outer screening ring 5, is provided above the first ring magnet assembly 7, as illustrated in Figure 1. The two assemblies 7,8 are placed so that the two ring magnets 2,4 have the same magnetic poles, for example the two North poles, adjacent one another. In this case, the two ring magnets 2, 4 will repel each other so that the upper ring magnet assembly 8 is, in effect, freely suspended above the lower ring magnet assembly 7 with an air gap 6 there between, by virtue of this magnetic repulsion.

Fixed to the upper ring magnet assembly 8 is a support spigot 9 onto which a piece of equipment may be supported.

The two ring magnet assemblies 7,8 are encased in a housing 10, made for example of any suitable non metallic material such as plastic of aluminium and lined with felt. The lower ring magnet assembly 7 is fixed inside the housing 10, with the upper ring magnet assembly 8 being freely moveable within the housing 10. The housing 10 serves to prevent lateral displacement of the upper ring magnet assembly 8 with respect to the lower ring magnet assembly 7.

In use, a piece of equipment, for example a Hi-Fi Amplifier 11 is placed upon the spigot 9, with the housing placed on the floor or a base 12. Any vibrations in the base 12 will be transmitted to the lower ring magnet assembly 7 through the housing 10, but will not be transmitted to the upper ring magnet assembly 8 because of the air gap 6 and the consequential lack of physical contact between the upper and the lower ring magnet assemblies 7,8, and the equipment supported on the spigot 9, will therefore be isolated from the external vibration. One or more of these isolators 1 can be used, as appropriate.

The ring magnets can be any known conventional ring magnet which is designed to reduce stray magnetic fields and concentrate the field only in the locality of the vibration isolator as much as possible so that the working parts of the device being supported are not adversely effected by the magnetic field.

As will be understood to a person skilled in the art, modifications are possible within the scope of the present invention, for example, other magnet configurations and types can be used.

Claims

1. A vibration isolator for isolating an object from external vibration, the vibration isolator comprising a first magnet assembly, including a first magnet, arranged to be supported by a possible source of external vibration, and a second magnet assembly, including a second magnet, and configured to support the object, the two magnet assemblies being configured such that the two magnets repel each other, whereby the second magnet assembly is freely suspended above the first magnet assembly, with an air gap there between, so that external vibrations from the source are transmitted to the first magnet assembly but isolated from the second magnet assembly and the supported object.

2. A vibration isolator according to claim 1, wherein the first and second magnets are ring magnets.

3. A vibration isolator according to claim 1 or claim 2, wherein the first and second magnet assemblies are enclosed in a housing, the first magnet assembly being fixed in the housing, the second magnet assembly being freely moveable within the housing but prevented from lateral movement by the housing.

4. A vibration isolator according to any preceding claim, wherein the second magnet assembly includes a spigot for supporting the object.

5. A vibration isolator as hereinbefore described with reference to the accompanying Figures.