The present application claims priority under 35 U.S.C. 119 (a)-(d) to Chinese patent applications Nos. 201110212166.6 and 201120268638.5, which were filed in the Chinese Patent Office on Jul. 27, 2011 and whose subject matter is incorporated herein by reference for all purposes.
The invention relates to a switch for on/off operation of electrical circuits and appliances, particularly a switch with contacts.
A conventional contact switch usually includes a housing formed by snap-fit of an upper cover and a base, and an operating lever and a movable contact holder with the operating lever and contact holding being movably-fit to each other. Driven by the operating lever, the switch effects the conversion between the switching-on and switching-off processes by the motion of the movable contact holder inside the housing. Currently available contact switches are unable to initiate the action of returning the switch to the initial off position upon switching-off after switching-on, resulting in serious damage to the contacts and shortened working life of the switches due to slow switching.
In order to eliminate the above-described disadvantages of conventional contact switches, one object of the present invention is to provide a switch with contacts which is able to initiate the process of returning to the initial off position upon switching-off after switching-on.
The above object is achieved by providing a switch with contacts, including a housing formed by snap-fit of an upper cover and a base, and an operating lever and movable contact holder movably-fit to each other. A stop device is also arranged in the housing, and a lock mechanism is provided between the stop device and the movable contact holder. An unlock mechanism is disposed between the stop device and the operating lever. The movable contact holder has two ends with the movable contact holder located in the position of the two ends. The stop device and movable contact holder are stopped and locked by the unlock mechanism.
An unlock point is set in the operating lever stroke. A proper unlock moment can be achieved by adjusting the unlock point position in the operating lever stroke. After the operating lever reaches the unlock point, the lock mechanism between the stop device and the movable contact holder can be unlocked by the unlock mechanism between the operating lever and the stop device. After the lock mechanism is released, with an elastic element driving the movable contact holder, the operating lever can move inside the housing.
After the switch with contacts is moved from the switching-off state to the switching-on state, the stop device and the movable contact holder are locked, which makes the switch with contacts revert to the switching-off state so that the movable contact holder cannot be set in motion before the unlock mechanism is actuated. After the operating lever moves to an unlock point, the lock mechanism is released by the unlock mechanism between the stop device and the operating lever so that the movable contact holder, actuated by the elastic element between the operating lever and movable contact holder, is set in quick motion. The movable contact on the movable contact holder is quickly separated from the stationery contact on the housing. As a result, the movable contact holder resets to the switching-off state and a “kick-in” function is finally affected.
According to a further embodiments of the preset invention, the stop device includes a stop member, an unlock member, a reset member and a positioning member. A lock mechanism is composed of the stop member and a position-locking member on the movable contact holder that cooperates with the stop member. A resetting force, formed by one end of the reset member pressing the housing, urges the stop member to touch the position-locking member on the movable contact holder so that the lock mechanism is locked. A pressing member, provided on the operating lever, presses against the unlock member and urges the stop member to separate from the position-locking member on the movable contact holder by overcoming the resetting force from the reset member. As a result, an unlock mechanism is formed by unlocking of the lock mechanism
According to a further embodiment of the present invention, the stop device includes a stop member, an unlock member, a reset member and a positioning member, which is connected to the limit member on the housing. A lock mechanism is composed of the stop member and a position-locking member on the movable contact holder in collaboration with the former. One end of the reset member, being received in a slot in the operating lever and touching the lever, can slide along with the operating lever. When the reset member moves together with the operating lever to the side where stop member lies, a clockwise resetting force is generated, which urges the stop member to come close to the position-locking member on the movable contact holder so that the lock mechanism is locked and thus stopped; when the reset member moves together with the operating lever to the side where unlock member lies, a counterclockwise unlocking force is formed, which urges the stop member to separate from the position-locking member on the movable contact holder so that the unlock mechanism is formed by the unlock of the lock mechanism.
The positioning member, which is a lever, can turn inside the position-locking member, which is a notch. The reset member is an elastic element. The positioning member, which can alternatively be a straight surface, can slide on the positioning-locking member, which also can be a straight surface. Both the pressing member and the unlock member are inclined surfaces. The two inclined surfaces, pressing each other, form a component force, which balances the resetting force from the reset member.
The positions at both ends of the movable contact holder are switching-on and switching-off positions, respectively.
The movable contact holder, with the present switch put in the switching-on position, is located in the end position. The stop device and the movable contact holder are locked by the lock mechanism.
A movable contact is provided on the movable contact holder and a stationery contact arranged on the housing. With the switch located in the switching-on position, the movable contact and the stationery contact are closed, forming a conductive electrical circuit. With the switch located in the switching-off position, the movable contact is separated from the stationery contact, forming an open circuit.
By adjusting the unlock point to a proper position, less time will be needed for the movable contact holder to move from the switching-on position to the switching-off position inside the housing.
The present invention offers the following distinct advantages over known switching devices: First, the stop device is provided between the operating lever and the movable contact holder. When operating lever travels in its stroke and has not arrived ahead of an unlock point, no separating action will occur. The movable contact holder is locked by the lock mechanism (composed of position-locking member and stop member) via the movable contact holder, urged by the elastic element of the operating lever, producing a rightward separating force. After the operating lever arrives behind an unlock point in its stroke, with the pressing member above the operating lever pressing the unlock member, the stop member 4a is forced to separate from the position-locking member, which enables the movable contact holder to begin to make a quick motion under the pressure of the elastic element, causing the movable contact on the movable contact holder to separate from the stationery contact on the housing. Thus, a separating motion is produced. The above-described manner of contact separation is such that the contact separating motion speed is not affected by the operator's manipulation of the operating lever. The contact separating stability is thereby enhanced and the contact working life prolonged, which improves the stability of the present switch.
Second, by the adoption of the lock mechanism on the movable contact holder, a situation can be avoided, in which the switch cannot be turned off due to contact pressure reducing to near zero, with the elasticity of the elastic element changing to a certain degree. The movable contact can be separated from the stationery contact only when the operating lever moves behind the unlock point so that an electrical circuit cannot be broken owing to the contact adhesion resulting from zero separating pressure. Therefore, the switch safety according to the present invention is considerably enhanced by inclusion of this lock mechanism.
Third, with the lock mechanism provided on the movable contact holder, when the switch is put in the process from the switching-off position to the switching-on position, if the movable contact is connected with the stationery contact, the movable contact holder will be locked by the lock mechanism. Therefore, a situation is avoided which the movable contact and the stationery contact are closed once again after their separation, resulting in electric are connected for the second time (which is caused by the separation of the two contacts resulting from the rebounce of the movable contact holder after the holder makes an impact on the housing). This avoidance significantly reduces are erosion to the contacts and prolongs the working life of the contacts and the switch.
Fourth, with the lock mechanism provided on the movable contact holder, the pressure of the present switch contacts in use will not be affected by decreased elasticity of the elastic element and the connecting pressure between the contacts. Furthermore, the safety of the switch can be more reliably guaranteed.
The invention will now be explained in greater detail with reference to the accompanying drawings wherein:
Referring now to the figures, a switch with contacts according to the present invention includes a housing 1 formed by snap-fit of an upper cover 12 and a base 11, an operating lever 2, and movable contact holder 3 movably-fit to each other. In the housing, a stop device 4 is provided with a lock mechanism 5 disposed between the stop device 4 and the movable contact holder 3; an unlock mechanism 6 is arranged between the stop device 4 and the operating lever 2; the movable contact holder 3 having positions at its two ends with the movable contact holder 3 located in the positions of the two ends, the stop device 4 and the movable contact holder 3 are locked and stopped by the unlock mechanism 5. An unlock point is set in the stroke of the operating lever 2. A proper unlock moment can be obtained by adjusting the unlock point position in the stroke of the operating lever 2. After the operating lever 2 reaches the unlock point, the lock mechanism 5 between the stop device 4 and the movable contact holder 3 can be unlocked by the unlock mechanism 6 between the operating lever 2 and the stop device 4. After the lock mechanism 5 between the stop device 4 and the movable contact holder 3 is released, with an elastic element 2a driving the movable contact holder 3, the operating lever 2 can move inside the housing. By the above design, when the switch with contacts converts from the switching-off state to the switching-on state, the stop device 4 and the movable contact holder 3 are locked, which puts the switch in the process of reverting to the switching-off state so that the movable contact holder 3 is not set in motion before the unlock mechanism 6 is actuated. After the operating lever 2 moves to an unlock point, the lock mechanism 5 is released by the unlock mechanism 6 between the stop device 4 and the operating lever 2 so that the movable contact holder 3, actuated by the elastic element 2a between the operating lever 2 and movable contact holder 3, is set in quick motion, and that the movable contact 3b is put in quick separation from the stationery contact 11a. As a result, the movable contact holder 3 resets to the switching-off state and kick function is finally affected. The stop device 4, the lock mechanism 5 and the unlock mechanism 6 of the present invention can be set in varied ways.
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The above three exemplary embodiments provide only three types of specific constructions of the stop device 4 and the present invention is not limited to these constructions. Stop devices that are able to produce a resetting force by the reset member 4c pressing against the housing 1 to effect, upon the movable contact holder 3 being put in the switching-on state, the lock of the stop device 4 and the movable contact holder 3, and configured to effect the unlock by the pressing member 3b pressing against the unlock member 4b, upon the operating lever moving leftwards and arriving behind the unlocking point, are all contemplated.
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With reference to
Exemplary Embodiment 4 provides only one of the specific constructions of the stop device 4 and is not limited to the construction. Embodiments, in which the reset member 4c can produce a resetting force by pressing against the operating lever 2 and urge the lock of the stop device 4 and the movable contact holder 3 after the movable contact holder 3 reaches the switching—on state, and unlock is realized by the reset member 4c pressing against the unlock member 4b after the operating lever 2 travels leftwards to an unlock dot, are all also contemplated.
The above four embodiments provide only one of the specific constructions of the operating lever 2, the movable contact holder 3 and the elastic element 2a, and are not limited to the constructions. Other constructional forms, including rotation and swinging, which can affect the connection of the movable contact and the stationery contact by making the operating lever move in one direction, and can realize the separation of the movable contact and the stationery contact by making the operating lever move in another direction as well, are all contemplated.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.
While the invention has been illustrated and described as embodied in on/off switch with contacts for electrical circuits and appliances it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.
Number | Date | Country | Kind |
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201110212166.6 | Jul 2011 | CN | national |
201120268638.5 | Jul 2011 | CN | national |