BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side sectional view showing a structure of a rotary handle of an external operation handle device in an embodiment according to the invention;
FIG. 2 is a sectional view taken along line 2-2 in FIG. 1;
FIGS. 3(
a) and 3(b) show a detailed structure of the cam mechanism in FIG. 1, in which FIG. 3(a) is a plan view showing a schematic of a groove cam with steps and FIG. 3(b) is a developed sectional view of the groove cam along the path on the cam shown in FIG. 3(a);
FIG. 4 shows locking notches formed in an inner periphery of an opening in a handle cover corresponding to ON, OFF and OPEN positions of the rotary handle, and used for anchoring and holding a handle lock lever;
FIG. 5 shows an arrangement and construction of a door lock lever provided in an external operation handle device of an embodiment according to the invention;
FIG. 6 shows an overall structure including an external operation handle device of an embodiment according to the invention combined with a circuit breaker;
FIG. 7 shows an external operation handle device having a conventional structure combined with a circuit breaker;
FIG. 8 is a perspective view corresponding to FIG. 7
FIG. 9 is an exploded perspective view showing an interlock structure between the external operation handle device of FIG. 7 and a door of a switch board;
FIG. 10 shows an arrangement and construction of a door lock lever provided in the external operation handle device of FIG. 7; and
FIGS. 11(
a) and 11(b) show a state of handle lock in which a handle lock lever is pulled out from the external operation handle device of FIG. 7 and a padlock is hung on the handle lock lever, in which FIG. 11(a) is a plan view and FIG. 11(b) is a side view.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Some preferred embodiments according to the present invention will be described with reference to FIGS. 1 through 6, in which FIGS. 1 and 2 show a structure of the rotary handle; FIGS. 3(a) and 3(b) show a development of an alternate operation type cam mechanism provided in a handle lock lever; FIG. 4 is a plan view of a handle cover; FIG. 5 shows a structure of a door lock lever provided on the back surface of the handle cover; and FIG. 6 shows an overall structure of an external operation handle device combined with a circuit breaker. The same members in the embodiment are given the same symbols as in FIGS. 7 through 10 and description is omitted.
The external operation handle device shown in FIG. 6 has basically a similar structure to the conventional structure as shown in FIGS. 7 and 8. Nevertheless, the rotary handle 4 of the embodiment shown in FIG. 6 comprises a newly added cam mechanism 15 of an alternate operation type, details of which will be described hereinafter. Further, in an inner periphery of an opening on a top surface of a handle cover 7 mounting the rotary handle 4 (see FIG. 4), locking notches 19a, 19b, and 19c are formed corresponding to OPEN position for unlocking a door panel as well as ON and OFF positions of the rotary handle 4, the lock notches being provided for anchoring and holding a handle lock lever 8 at the respective pull out positions. The following describes details of the structure and operation of these parts.
Firstly, referring to FIG. 1 and FIG. 2, the grip portion of the rotary handle 4 includes a handle lock lever 8 that can be pulled out and pushed in, in the direction indicated by the allow P. The handle lock lever 8 is guided and supported through a guide pin 8b on the rotary handle 4. The handle lock lever 8 has a hole 8a for hanging a padlock at the outer end and an anchor rib 8c formed at the bottom of the handle lock lever 8 for anchoring and holding the handle lock lever 8 on the handle cover 7. The anchor rib 8c projects downward through a clearance groove 4b-1 in the radial direction cut in a disk-shaped flange part 4b of the rotary handle 4.
A cam mechanism 15 of an alternate operation type is constructed in the rotary handle 4 as described hereinafter. The cam mechanism 15 consists of a groove cam with steps 16 carved on the side face of the handle lock lever 8, a control bar 17 having an L-shaped bend at its tip to slide on the cam surface of the groove cam 16, and an urging spring 18 (a compression spring) for pushing the handle lock lever 8 towards the pull-out direction. The control bar 17 is a wire spring having an L-shaped bend (in an acute angle) at one end thereof and a C-shaped bend at the other end thereof, the latter being pushed into and held at a holder groove 4c in a slit shape formed in the rotary handle 4.
FIGS. 3(
a) and 3(b) show a detailed configuration of the groove cam 16 with steps. The groove cam 16 has a cam pathway with a heart shape starting at a part A, through parts B, C, D, E, F, G, and H, and returning to the part A, as shown in FIG. 3(a). At the locations of corners along the pathway, formed are steps B, D, F, and H that have a ratchet shape and exhibit unidirectional (backstop) property.
When the handle lock lever 8, which includes the cam mechanism 15 having the above-described construction, is stored in the rotary handle 4, the hook of the control bar 17 stays at E in the cam pathway in FIGS. 3(a) and 3(b); this position is referred to as a waiting position P1. From this state, when the outer end of the handle lock lever 8 is pushed by a finger towards the interior of the rotary handle 4 (first push operation), the hook of the control bar 17 slides beyond the slope of the step F moving into position G. (Reverse motion from E to C is obstructed by the step D.) Leaving the finger off the handle lock lever 8 at this state, the lock lever slides towards the pulling out direction receiving a spring force of the urging spring 18. During this sliding process, the hook of the control bar 17 moves from the position G and slides beyond the slope of the step H moving into position A, which is referred to as a lock position P2. In this state, the outer end of the handle lock lever 8 is projecting out from the periphery of the rotary handle 4.
From this state, when the handle lock lever 8 is pushed inward again (second push operation), the hook of the control lever 17 slides beyond the slope of the step B moving into position C. (Reverse motion from A to G is obstructed by the step H.) Leaving the finger off the handle lock lever 8, the lock lever is pushed back by receiving the spring force of the urging spring 18. In this moving back process, the hook of the control lever 17 slides from the position C, over the slope of the step D, and back to the position E (the waiting position P1). Thus, the handle lock lever 8 returns to the initial waiting position.
Relating to the handle lock mechanism described previously, locking notches are formed on the top surface of the handle cover, which receives and supports the rotary handle 4, as describe below. Referring to FIG. 4, locking notches 19a, 19b, and 19c are formed by partially cutting off the inner periphery of an opening on the top surface of the handle cover 7 corresponding to the ON, OFF, and OPEN positions, respectively, of the rotary handle 4, for anchoring and holding (inhibiting rotational motion) the anchor rib 8c of the handle lock lever 8 projecting out of the rotary handle 4. The depths of the locking notches 19a and 19b corresponding to the ON and OFF positions are large because a padlock is hung on the handle lock lever 8 at the ON and OFF positions of the rotary handle as mentioned referring to FIG. 11. At the OPEN position, on the other hand, a padlock does not need to be hung on the handle lock lever 8, so the locking notch 19c is designed to be shallow.
In a door lock mechanism shown in FIG. 5 of the embodiment, a door lock lever 9 is pivotally supported by a support pin 9a like the conventional structure of FIG. 10 and the lever cam portion of the door lock lever 9 is arranged to project into the moving path of a protrusion 5b of the turn base 5 connected to the handle shaft 4a. The door lock lever 9 is not provided with a leaf spring 13 for self supporting in the conventional structure (see FIG. 10). Instead, an urging spring 20, a tension coil spring, is provided to urge the door lock lever 9 towards the locking direction.
The following describes an operation of an external operation handle device 2 having the above-described construction. To lock the rotary handle 4 at the ON or OFF position, after turning the rotary handle 4 to the ON or OFF position, the handle lock lever 8 is touched by a finger at its end and once pushed into the interior of the rotary handle 4, and then released (first push operation). Through this operation, the alternate operation of the cam mechanism 15 as described earlier referring to FIG. 3 moves the handle lock lever 8 to the pulled out position and at the same time, the anchor rib 8c engages with the locking notch 19a or 19b formed in the handle cover 7 to hold the handle lock lever 8 at this position inhibiting its rotation. In this state, a padlock 14 is hung on the handle lock lever 8 to lock the rotary handle 4 at the ON or OFF position (see FIG. 11). To release lock of the rotary handle 4, after removing the padlock 14, the handle lock lever 8 is pushed at its end towards the interior of the rotary handle 4 and released (second push operation). Through this operation, the handle lock lever 8 returns to the waiting position and is stored in the rotary handle 4 allowing the rotary handle to be turned.
In order to open the door panel 10 of the switch board as shown in FIG. 9, the rotary handle 4 of the external operation handle device 2 is first turned to the OFF position to open the circuit breaker 1. Subsequently, the rotary handle 4 is further turned from the OFF position to the OPEN position. Through this operation, the protrusion 5b of the turn base 5 in FIG. 5 moves counterclockwise and pushes the cam portion of the door lock lever 9. As a result, the door lock lever 9 rotates clockwise about the support pin 9a and is released from the latch 12a to unlock the door panel. When the rotary handle 4 is turned to the OPEN position, the anchor rib 8c of the handle lock lever 9 comes to face the locking notch 19c shown in FIG. 4. Pushing the handle lock lever 8 at this OPEN position corresponding to the unlock operation for the door panel, the anchor rib 8c engages with the locking notch 19c through the alternate operation of the cam mechanism 15 and the handle lock lever 8 is anchored and held at this position. In this condition, the interlock has been released between the external operation handle device 2 and the door of the switch board, and the door lock lever 9 is held at the unlock position by itself without touching the rotary handle 4, allowing the door panel 10 to be opened safely.
In order to close and lock the door of the switch board, the opened door panel 10 is returned to the closed position and subsequently the handle lock lever 8 is pushed to return to the waiting position. Then, the rotary handle 4 is moved back from the OPEN position to the OFF position. Through this operation, the door lock lever 9 is released from the self-holding condition at the unlock position and returns to the locked position receiving a spring force of the urging spring 20, locking door of the switch board at the closed position.
The disclosure of Japanese Patent Application No. 2006-255923 filed on Sep. 21, 2006 is incorporated as a reference.
While the invention has been explained with reference to the specific embodiments of the invention, the explanation is illustrative and the invention is limited only by the appended claims
Patent Application
20080073188
