Circular magnetic switch

A circular magnetic switch comprises a circuit device and a ring. The circuit device is provided with a plurality of magnetic induction elements and the ring is provided with a plurality of circularly arranged magnets, so that the magnetic induction elements are able to sense the relatively positional changes of the magnets when the ring is turned. The circular magnetic switch is characterized in that: at least an anti-interference magnet is further provided between at least two magnets of the plurality of magnets and the polarity of two magnets is opposite to that of the anti-inference magnets that is provided between the two magnets.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a magnetic switch and, more particularly, to a circular magnetic switch that is provided with at least an anti-interference magnets between two magnets to avoid the interference generated from other magnets toward the magnetic induction element, and is suitable for portable lighting devices such as flashlights.

2. Description of the Prior Art

With respect to multifunctional portable lighting devices such as a flashlight, it is difficult to design the lighting devices where all setting and operations can be controlled by one key because of size, appearance, and waterproofing problems. Even though the design of multiple keys is applied, it is necessary to add many extra waterproof structures. Besides, some lighting devices are designed to have multiple keys controlled by pressing the keys at intervals and in sequence to perform different functions. It is difficult for users to definitely ascertain the instant status and to enter the desired mode directly.

It is widely known in the field of multifunctional portable lighting devices to produce electric current that are equivalent to different functional keys by using both of magnetic induction elements and magnets. Conventionally, the magnetic induction elements are welded on a round circuit board whereon is fixed in a tube made of plastics, metal, or other waterproof material. The magnets corresponding to the magnetic induction elements are fixed on an internal rotating ring of a ring structure outside the tube. The ring structure can also be made of plastics, metal, or other waterproof material. When the magnets are moved by turning the ring structure, the relatively positional changes of the magnets can be sensed by the magnetic induction elements for performing following corresponding procedures.

By reason of the ring structure can be turned 360 degrees, the magnets can be rotated and positioned in a step-type way by an elastic piece. Therefore, through the movement of the magnets, different combination patterns of the magnetic induction elements can be produced and the produced combination patterns can be detected by the scanning of buttons that are equivalent to quick buttons functionally. Besides, by providing the ring structure with different images, users can operate desired functions and ascertain the function used currently in order to overcome the drawbacks mentioned above. However, in practice, the magnetic induction element needs to be disposed corresponding to the magnet and consequently magnetic hysteresis may be produced. The magnetic hysteresis caused by other magnets will result in the interference of the normal function of the magnetic induction element. In other words, the magnetic induction element that should not be actuated is actuated as a result of the magnetic hysteresis. This phenomenon is obvious in small portable lighting devices with many combination patterns. Therefore, how to apply a magnetic switch to a small portable lighting device with many combination patterns is a crucial problem needs to be solved for people in the art.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a circular magnetic switch for preventing magnetic induction elements from magnetic interference.

In order to achieve the above object, the present invention provides a circular magnetic switch comprising a circuit device and a ring. The circuit device is provided with a plurality of magnetic induction elements and the ring is provided with a plurality of circularly arranged magnets, so that the magnetic induction elements are able to sense the relatively positional changes of the magnets when the ring is turned. The circular magnetic switch is characterized in that: at least an anti-interference magnet is further provided between at least two magnets of the plurality of magnets and the polarity of two magnets is opposite to that of the anti-inference magnet provided between the two magnets.

The following detailed description, given by way of examples or embodiments, will best be understood in conjunction with the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1-3shows a preferred embodiment of a circular magnetic switch1according to the present invention. The circular magnetic switch1comprises a circuit device2and a ring3.

The circuit device2is provided with a plurality of magnetic induction elements21and the ring3is provided with a plurality of circularly arranged magnets31. When the ring3is turned, the positions of the magnets31will be changed accordingly and the magnetic induction elements21are able to sense the relatively positional changes of the magnets31. Besides, an anti-interference magnet32is provided between at least two of the plural magnets31on the ring3. The polarity of the two magnets31is opposite to the anti-interference magnet32which is provided between the two magnets31. Moreover, the ring3is provided with a plurality of holes311,312for disposing the magnets31and the anti-interference magnets32.

When the present invention is in practice, for example, used in a flashlight4, the number of the anti-interference magnets32is determined according to the size of the flashlight4and the desired number of steps for controlling the switch. In this embodiment, the present invention is provided with a plurality of anti-interference magnets32. The polarity of the anti-interference magnets32is opposite to that of the two magnets31provided at two sides of the anti-interference magnet32. At least one anti-interference magnet32is disposed between any two neighboring magnets31and, if necessary, the two magnets31can be provided with plural anti-interference magnets32there between.

Accordingly, the magnetic interference form the magnetic lines of the magnets31toward the magnetic induction element21can be reduced when the magnetic induction element21is actuated because at least one side of the magnet31corresponding to the magnetic induction element21is provided with the anti-interference magnet32with opposite polarity compared with the magnet31. Consequently, the magnetic induction element21can work normally. Therefore, the conventional problem, that is, the magnetic induction element that should not be actuated is actuated as a result of the magnetic hysteresis, can be solved.

Moreover, the anti-interference effect can be enhanced by some modifications. For example, let the magnetic force of each anti-interference magnet32be weaker than that of the two magnets31provided at two sides of the anti-interference magnet32or let the anti-interference magnet32and the magnet31be cylindrical and the surface area of the anti-interference magnet32be smaller than that of the magnet31.

Accordingly, as disclosed in the above description and attached drawings, the present invention can provide a circular magnetic switch. It is new and can be put into industrial use.

Although the embodiments of the present invention have been described in detail, many modifications and variations may be made by those skilled in the art from the teachings disclosed hereinabove. Therefore, it should be understood that any modification and variation equivalent to the spirit of the present invention be regarded to fall into the scope defined by the appended claims.