EP2306480B1

EP2306480B1 - A switching device

Info

Publication number: EP2306480B1
Application number: EP10354046.4A
Authority: EP
Inventors: Cheong Wai Luen
Original assignee: Schneider Electric Industries SAS
Current assignee: Schneider Electric Industries SAS
Priority date: 2009-09-30
Filing date: 2010-09-08
Publication date: 2016-09-07
Anticipated expiration: 2030-09-08
Also published as: CN102034636A; EP2306480A2; SG169917A1; EP2306480A3; CN102034636B

Description

Field of the Invention

The present invention relates generally to a switching device. More particularly, the invention encompasses a switching device with an improved locking means.

Background of the Invention

Electrical systems such as power units, circuit breakers, electrical drivers or the like are usually encased within a chassis to house and protect the systems against elements. A removable cover on the chassis is provided for access to adjust and control the electrical systems, which may be inconvenient and at times difficult particularly within a space constraint operating environment.
A common solution is to install one or more switches outside the chassis to operate the electrical systems. In order to prevent accidental or unauthorized operation of the switch, some form of locking means is usually provided within the switch.
However, most switches with locking means are constructed with bulky locking mechanisms that inevitably increase the thickness and height of the switches. Such switches when installed on the chassis would result in high protruding parts projecting from the surface of the chassis which are space consuming and may cause obstructions and even dangers to passers-by knocking inadvertently on the switches resulting in injuries.
JP 2004-355 923 concerns a switching device having a housing. The switching device comprises a lock piece. A cam is pushing the lock piece from a locking position to an unlocking position.
EP 1 729 313 A1 concerns switching device having a locking unit being mobile in translation along an axis between a locking position of a rotation of a handle and an unlocking position. A sliding unit is mounted on the handle and includes an opening for receiving padlocks in the locking position. A driving mechanism formed of an articulated rod and a toothed wheel cooperates with the locking unit and the sliding unit for converting a translation movement of the locking unit in one direction into a translation movement of the sliding unit in the opposite direction.
DE 196 03 238 C1 concerns a lockable actuating device for a rotary switch. A turning handle, secured in a rotationally rigid manner on an actuating shaft, is provided with at least one lock opening in which padlocks can be placed. In the turning handle a locking slide, which can be actuated from the exterior and locks and unlocks the lock opening, is mounted so as to be displaceable perpendicular to the actuating shaft axis and a lock bolt, which can be actuated by the locking slide against spring force, is mounted so as to be displaceable parallel to the actuating shaft axis.
There is therefore a need for a switching device with an improved locking means to address the problems mentioned above.

Summary of Invention

In one aspect of the present invention, there is provided a switching device operable between different set-points according to claim 1.
The knob further includes a handle adapted for displacement between a resting position and an elevated position for controlling the latch triggering mechanism.
In a preferred embodiment, the latch is triggered by the latch triggering mechanism to directly engage the recess at right angle.
In another preferred embodiment, the latch is triggered by the latch triggering mechanism to directly engage the recess at substantially right angle.
In yet another preferred embodiment, the latch triggering mechanism comprises the cam coupled to the handle, said cam is moveable between a first direction and a second direction in concert with the handle during the handle displacement between the resting position and the elevated position.
In another aspect of the present invention, there is provided a method according to claim 6.
In another aspect of the present invention, there is provided a method according to claim 7.

Brief Description of the Drawings

Fig. 1 shows a plan view of a switch in accordance to a preferred embodiment of the invention;
Fig. 2 shows a plan view of an alternative embodiment with an added padlock;
Fig. 3 shows a cross sectional view of the preferred embodiment;
Fig. 4 shows an expanded view of a locking means of the preferred embodiment;
Figs. 5a-5d show cross sectional views of the preferred embodiment with a handle of the switch being pulled-up for locking.

Preferred Embodiments of the Invention

The present invention provides a switch 100 comprising a housing 104 and a knob 116 disposed within the housing 104 as shown in Fig. 1. The switch 100 may be mounted on an external surface of a chassis of an electrical system and thereby providing a means for selectively activating and deactivating one or more states of the electrical system.
The switch 100 may be operated by turning the knob 116. The knob 116 may be turned between 2 or more set-points that correspond to 2 or more states of the electrical system. In a preferred embodiment of the invention, the knob 116 is turned between 2 set-points that correspond to an "ON" state and an "OFF" state of the electrical system.
In another embodiment of the invention, a locking means is provided to prevent accidental triggering or unauthorized turning of the knob 116 once the knob is disposed at any one set-point. The locking means allows the switch 100 to be locked once disposed at a set-point and turning of the knob 116 is therefore disabled.
The locking means comprises a latch 108 formed within the knob 116, a recess 110 formed on an inner perimeter surface of the housing 104 and a latch triggering mechanism provided within the knob 116. The latch 108 is releasable from the knob 116 by the latch triggering mechanism to selectively engage or disengage the latch 108 into or from the recess 110.
Engaging or disengaging the latch 108 vis-à-vis the recess 110 will respectively lock or unlock the knob 116 at any particular set-point. In a preferred embodiment, the latch 108 is triggered by the latch triggering mechanism to selectively engage or disengage into or from the recess 110 at right angle.
Locking of a subsequent set-point may be provided by forming an additional recess at the desired set-point location. For example, a first recess 110 may be provided for locking the switch 100 at the "ON" set-point position while a second recess 112 may be provided 90 degree apart for locking the switch 100 at the "OFF" set-point position.
In a preferred embodiment, a handle 102 is provided on the knob 116 for displacement between a resting position, a position in which the handle 102 is fully inserted on the knob 116, and an elevated position. The latch triggering mechanism is initiated by pulling the handle 102 from its resting position to the elevated position. The pulling of the handle 102 initiates the latch 108 triggering mechanism within the knob 116 to release the latch 108 for engagement into the recess 110. When the handle 102 is fully elevated, the latch 108 is engaged completely within the recess 110 and the turning of the knob 116 is thereby disabled.
Conversely, restoring the handle 102 to its resting position would result in the latch triggering mechanism to disengage the latch 108 from the recess 110 and to retract back into the knob 116. The turning of the knob 116 is thereby enabled.
In one embodiment of the present invention, a padlock 600 as shown in Fig. 2 may be used to maintain the elevated position of the handle 102. The use of padlock 600 provides an additional layer of secured locking and preventing any tampering attempt to forcibly turn the knob 116 when the latch 108 is engaged within the recess 110.
The movement of the handle 102 from its rested position to its elevated position and vice-versa is guided by a pair of handle guides 322 and 324 disposed within 2 guide units 304 and 306 located within the knob 116, as shown in Fig. 3.
An opening 310 may be provided to accommodate a connecting member such as a shaft to couple the knob 116 to an actuator of the electrical system. The turning of the knob 116 to change between different set-points correspondingly rotate the actuator of the electrical system through the connecting shaft to selectively change between different states of the electrical system.
The latch triggering mechanism comprises an actuator in the form of a cam 302. The cam 302 may be coupled to the handle 102 through a handle extension 309. A securing device such as a screw 315 may be used to couple the cam 302 to the handle extension 309. As the handle 102 is displaced from the resting position to the elevated position, the cam 302 which is coupled to the handle extension 309 is correspondingly displaced at the same distance and direction. Conversely, as the handle 102 is restored to its resting position, the cam 302 is similarly restored to its original position. The movement of the cam 302 is thereby set in concert with the movement of the handle 102.
The movement of the handle 102 between the resting position and the elevated position may be converted into sideway movement of the latch 108 through the cam 302, wherein the direction of said sideway movement is preferably at right angle or substantially at right angle to the direction of the handle movement.
The latch 108 may be displaced by the cam 302 to move between a first origin position and a second locking position. In a preferred embodiment, the movement of the handle 102 from the resting position to the elevated may be converted by the cam 302 into movement of the latch 108 from its first origin position within the knob 116 into the second locking position in the recess 110, thereby locking the switch 100.
In the same embodiment, the displacement of the handle 102 from the elevated position to the resting position may be converted by the cam 302 into movement of the latch 108 from the second locking position in the recess 110 back to its first origin position within the knob 116, thereby unlocking the switch 100.
The movement of the cam 302 may be converted into displacement of the latch 108 through the acting of any one of defined profiles 408 and 412 formed on the cam 302 against a relating defined profile 403 or 415 formed on the latch 108 as shown in Fig. 4. When one defined profile on the cam 302 is acting on another relating defined profile on the latch 108, the orientation of the other defined profiles is aligned in a state of non-acting.
During movement of the cam 302 in a first direction, the defined profile 408 on the cam 302 may be arranged to act and slide against a relating defined profile 403 on the latch 108 so as to displace the latch 108 from the first origin position to the second locking position. The other defined profiles 412 and 415 are configured to be aligned in a state of non-acting.
During movement of the cam 302 in a second direction, which is in opposite to the first direction, the defined profile 412 on the cam 302 may be arranged to slide against a relating defined profile 415 on the latch 108 to restore the latch 108 from the second locking position to its first origin position. The other defined profiles 403 and 408 are configured to be aligned in a state of non-acting.
In a preferred embodiment, the defined profiles 408 and 412 formed on the cam 302 and the corresponding relating defined profiles 403 and 415 formed on the latch 108 may be configured in the shape of a slope. Preferably, all defined profiles are formed of the same gradient.
An initial setting of a preferred embodiment of the present invention is shown in Fig. 5a. The handle 102 is set at resting position and the cam 302 is at its origin. As the handle 102 is pulled to an elevated position as shown by the direction 506, the cam 302 is moved in concert with the handle 102.
The movement of the cam 302 causes the defined profile 408 on the cam 302 to act and slide against a relating defined profile 403 on the latch 108 so as to displace the latch 108 from the first origin position to the second locking position as shown by direction 508 in Fig. 5b. The other defined profiles 412 and 415 are configured to be aligned in a state of non-acting.
When the handle 102 is fully elevated, the latch 108 is engaged within the recess 110 as shown in Fig. 5c and the turning of the handle 102 is thereby disabled. A padlock 600 may be used to maintain the elevated position of the handle 102 as shown in Fig 5d.
In the preferred embodiment, the handle 102 may be operated as a normally close handle. A biasing, preferably in the form of a spring 512 may be provided around the handle extension 309 as shown in Fig 5d to provide a constant pull on the handle into its resting position.
While the invention has been particularly shown and described with reference to various embodiments, it will be recognized by those skilled in the art that modifications and changes may be made to the present invention without departing from the scope thereof. The scope of the invention should therefore be determined not with reference to the above description but with reference to the appended claims.

Claims

A switching device (100) operable between different set-points for changing the state of operations of an electrical system comprising:
a housing (104) with a recess (110, 112) formed on an inner perimeter surface of said housing at any set-point; and

a knob (116) disposed within the housing and is turned to switch between different set-points, said knob includes a latch (108) and a latch triggering mechanism (302),

said latch is selectively releasable from the knob by the latch triggering mechanism to engage into or from the recess (110,112) for locking and unlocking the switching device, said knob includes a handle (102) adapted for displacement between a resting position and elevated position for controlling the latch triggering mechanism;

wherein said latch triggering mechanism includes a cam (302) moveable between a first direction and a second direction, which is in opposite to the first direction;

wherein during movement of the cam (302) in the first direction, said cam displaces the latch (108) from a first origin position within the knob to a locking position within the recess, thereby locking the switching device;

wherein during movement of the cam in a second direction, said cam displaces the latch from the second locking position back to the origin position, thereby unlocking the switching device, wherein said cam includes one or more defined profiles (408, 412) acting against one or more relating defined profiles (403, 415) on the latch resulting in displacement of the latch, wherein

during movement of the cam (302) in the first direction, a first defined profile (408) on the cam (302) is arranged to act and slide against a relating first defined profile (403) on the latch (108) so as to displace the latch (108) from the first origin position to the second locking position, characterized in that

during movement of the cam (302) in the second direction, a second defined profile (412) on the cam (302) is arranged to slide against a relating second defined profile (415) on the latch (108) to restore the latch (108) from the second locking position to its first origin position.
The switching device as claimed in Claim 1, wherein the direction of movement of said cam is substantially at right angle to the direction of movement of said latch.
The switching device as claimed in Claim 1 or 2, wherein said latch is triggered by the latch triggering mechanism to directly engage the recess at right angle.
The switching device as claimed in Claim 1, wherein the knob further includes a handle (102) adapted for displacement between a resting position and an elevated position for controlling the latch triggering mechanism.
The switching device as claimed in any preceding claims, wherein said handle is configured as a normally close handle by biasing a handle extension with a spring to provide a constant pull on the handle into its resting position.
A method for assembling a switching device operable between different set-points for changing the state of operations of an electrical system, said method includes the steps of:
providing a housing (104 with a recess (110, 112) formed on an inner perimeter surface of said housing at any set-point;

providing a knob with a built-in latch (108) and a latch triggering mechanism (302),

said latch is selectively releasable from the knob by the latch triggering mechanism to engage into or from the recess for locking or unlocking the switching device;

disposing said knob within the housing, said knob includes a handle (102) adapted for displacement between a resting position and elevated position for controlling the latch triggering mechanism, wherein

said latch triggering mechanism includes a cam (302) moveable between a first direction and a second direction, which is in opposite to the first direction;

wherein during movement of the cam (302) in the first direction, said cam displaces the latch (108) from a first origin position within the knob to a locking position within the recess, thereby locking the switching device;

wherein during movement of the cam in a second direction, said cam displaces the latch from the second locking position back to the origin position, thereby unlocking the switching device, wherein said cam includes one or more defined profiles (408, 412) acting against one or more relating defined profiles (403, 415) on the latch resulting in displacement of the latch, wherein

during movement of the cam (302) in the first direction, a first defined profile (408) on the cam (302) is arranged to act and slide against a relating first defined profile (403) on the latch (108) so as to displace the latch (108) from the first origin position to the second locking position, characterized in that

during movement of the cam (302) in the second direction, a second defined profile (412) on the cam (302) is arranged to slide against a relating second defined profile (415) on the latch (108) to restore the latch (108) from the second locking position to its first origin position.