GB2276910A

GB2276910A - A lock mechanism for an electric switchboard box

Info

Publication number: GB2276910A
Application number: GB9322777A
Authority: GB
Inventors: Hideaki Takimoto
Original assignee: Takigen Manufacturing Co Ltd
Current assignee: Takigen Manufacturing Co Ltd
Priority date: 1993-03-18
Filing date: 1993-11-04
Publication date: 1994-10-12
Anticipated expiration: 2013-11-04
Also published as: JPH0717203Y2; GB2276910B; KR940022869U; JPH0674003U; GB9322777D0; KR0128001Y1

Abstract

A lock handle mechanism advantageously used for an electric switchboard box includes a monolithic lock handle fully foldable in a housing of the box. The lock handle (8) is mounted to the housing (1) for vertical turning and lateral rotation end connected via a lock shaft (2) to a pivoted bolt (not shown) provided on the housing (1). The handle is pivoted on the end of the shaft so that it folds down in the housing, flush to the wall of the box. The free end of the handle has a formation (19) which engages a pivoted latch (23). It is then locked in its folded position by means of a barrell lock (14). <IMAGE>

Description

A LOCK HANDLE MECHANISM FOR AN ELECTRIC SWITCHBOARD BOX The present invention relates to a lock handle mechanism for an electric switchboard box, and more particularly relates a fold-in type lock handle mechanism for an electric switchboard box in which a lock handle is fully foldable in the box to present a flush outer surface when the box is closed.

One typical example of such a hold-in type lock handle mechanism is disclosed in Japanese Utility Model Publication Hei.4-36164.

The lock handle mechanism of the prior proposal includes a lock handle, a pivot shaft and a lock shaft substantially accommodated in the housing of the box. More specifically, the pivot shaft extends transverse the interior of the housing between two side walls. The lock handle extends in the vertical direction within the housing and made up of an upper first component and a lower second component which a coupled to each other. The first component is mounted at its upper and turnably to the pivot shaft and provided, at its lower end, with a cylindrical, hollow bearing. The second component is provided at its upper end with a cylindrical hollow projection which is rotatably inserted into the bearing on the first component. The lock shaft extends back to front in the housing of the box with its rear projection being associated with a rotation lock.

In the locking position, the lock shaft rests almost in the cylindrical projection on the second component and its rear projection is kept in engagement with the rotation lock. The box is locked against free opening.

For unlocking the box, the lock handle is manually pulled forwards out of the housing while turning about the pivot shaft. After complete extraction, the lock handle is pulled laterally. By this lateral pulling, the second component of the lock handle is turned with respect to the first component about the axis of its cylindrical projection. The first component does not follow this rotation due to coupling to the pivot shaft. However, the lock shaft follows this rotation and its rear projection is released from engagement with the rotation lock.

This prior art lock handle mechanism is, however highly complicated in construction because the lock handle is made up of two components and such a complicated construction unavoidably results in high production cost.

It is thus the primary object of the present invention to provide a lock handle mechanism for an electric switchboard box which is simple in construction and low in production cost.

In accordance with the present invention, a lock shaft is rotatably mounted to the upper section of a housing while extending from back to front in the housing, a fixer disc is mounted to the rear end of the lock shaft in an arrangement engageable with a lock provided on the housing, a lock handle is pivoted at its upper end to the front section of the lock shaft for vertical turning, a spring is interposed between the lock handle and the lock shaft so as to urge the lock handle to turn forwards and upwards out of the housing, a key-mechanism is mounted to the lower section of the housing in an arrangement engageable with the lower end of the lock handle, a transverse pin is fixed to the housing for sliding contact with the lower end of the lock handle when the latter turns, a push button block is pivoted to the housing below the lock handle and spring loaded for rotation towards the transverse pin, and a pawl is formed on the push button block for engagement with the lower end of the lock handle.

A specific embodiment of the invention is described below with reference to the accompanying drawings, of which: Fig.l is a side view, partly in section, of one embodiment of the lock handle mechanism in accordance with the present invention with its lock handle being folded in its housing, Fig.2 is a side view, partly omitted and partly in section of the lock handle mechanism shown in Fig.l with the lock handle being pulled out of the housing, Fig.3 is a front view of the lock handle mechanism shown in Fig.l, Fig.4 is a side view, partly in section, of the lock handle mechanism shown in Fig.l on a process of unlocking, Fig.5 is a side view, partly in section, of the lock handle mechanism shown in Fig.l after complete unlocking, and Fig.6 is a side view, partly in section, of the lock handle mechanism shown in Fig.l in the process of locking.

One embodiment of the lock handle mechanism in accordance with the present invention is shown in Figs.l to 3, in which a housing 1 of the mechanism is mounted to, for example, a front panel of an electric switch box (not shown). In the illustration, the left side corresponds to the front side of the box. A lock shaft 2 is rotatably inserted into the upper section of the housing with its rear extension 2a extending from the housing 1. The rear extension 2a is associated with a fixer disc 3 which can, depending on its rotation angle, come into engagement with a proper lock (not shown) provided on the box. The lock shaft 2 is supported by a collar 4 which is fixed to the housing 1 via a set screw 5 in tight abutment with a shoulder formed on the housing 1.

The collar 4 thus locks the lock shaft 2 against axial movement whilst allowing it axial rotation relative to the housing 1. The lock shaft 2 is provided at its front end with a head piece 6.

In the condition shown in Fig.l, i.e. in the locking position, a lock handle 8 is folded in a space 7 reserved in the housing 1. Near the proximal end, i.e. the upper end, the lock handle 8 is provided with a rear bulge 9 provided with a vertical slot 10. Presence of this rear bulge 9 is best seen in Fig.2. The slot 10 idly receives a pivot shaft 11 which project laterally from the head piece 6 of the lock shaft 2. Thus, the lock handle 8 is movable relative to the head piece 6 within the longitudinal range of the slot 10 in the rear bulge 9. In addition the lock handle 8 is turnable in the vertical direction about the pivot shaft 11. Further thanks to the above-described shaft to slot engagement, the lock handle 8 is rotatable with the lock shaft 2 about the axis of the latter.

The head piece 6 is provided at its front end with an upper champer 12 which limits the extent of upward turning of the lock handle 8. As best seen in Fig.2 a coil spring 13 is interposed between the head piece 6 of the lock shaft 2 and the rear bulge 9 of the lock handle 8 so as to always urge the lock handle 8 to turn upwards as shown in Fig.2.

The distal end, i.e. the lower end, of the lock handle 8 is associated with a tumbler-key mechanism 14 for locking the lock handle 8 to the housing 1. More specifically, the tumblerkey mechanism 14 is provided with a key plate 15 which comes in engagement with a pin 16, depending on its vertical position.

The pin 16 is transversely coupled to the distal end section of the housing 1. At the distal end, the lock handle 8 is provided on the rear side with a pair of continuous upper and lower slopes 17 and 18. The upper slope 17 (first slope) is for pressure contact with the transverse pin 16 when the lock shaft 8 is folded in the housing 1. Due to this pin to slope contact, the lock handle 8 is pressed upwards when folded in. Next to the lower slope (second slope), the distal end of the lock handle 8 is further provided with a hook 19 directed forwards.

Below the lock handle 8, a push button block 20 is pivoted to a transverse pin 21 mounted to the housing 1. Surrounding the transverse pin 21, a coil spring 22 is interposed between the push button block 20 and the housing 1 so as to always urge the push button block 20 to a direction opposite to the turning direction of the lock handle 8. Angular movement of the push button block 20 is limited through pressure contact with the transverse pin 16. The push button block 20 is provided on its upper front side with a pawl 23 adapted for engagement with the hook 19 on the lock handle 8. This pawl to handle engagement keep the lock handle 8 be maintained within the housing 1, The key mechanism 14 is operable by a separate key 24.

The lock handle mechanism operates as follows; under the condition shown in Fig.l, the lock handle mechanism is in its locking position and the lock handle 8 is fully folded in the housing 1. The key 24 is inserted into the tumbler-key mechanism 14 and turned in the unlocking direction. This key operation releases the key plate 15 out of engagement with the transverse pin 16.

Next, the push button block 20 is manually depressed as shown in Fig.4. The push button block 20 then rotate counterclockwise about the transverse pin 21 and its pawl 23 is released from engagement with the hook 19 on the lock handle 8 which is then turned forwards and upwards due to operation by the coil spring 13. This turning of the lock handle 8 is stopped as its proximal end abuts against the chamfer 12 on the head piece 6 of the lock shaft 2 as shown in Fig.5. Under this condition, the lock handle 8 is manually rotated laterally over about 90 degrees and the lock shaft 2 follows this rotation. As a result, the fixer disc 3 on the lock shaft 2 also rotates in the same direction so as to be released from engagement with the lock provided on the box. Thus, the lock handle mechanism is now in its unlocking position and the front panel of the box is ready for free opening by hand.

For locking of the entire arrangement, the front panel of the box is closed and the lock handle 8 is rotated laterally back to its initial angular position. This reverse lateral rotation of the lock handle 8 brings the fixer plate 3 again into engagement with the lock provided on the box.

Under this condition, the lock handle 8 is manually turned rearwards and downwards into the housing 1 as shown in Fig.6.

During this turning, the first slope 17 on the distal end of the lock handle 8 slides on the transverse pin 16 on the housing 1 and, due to this sliding contact, the entire lock handle 8 is pushed upwards to the position shown in Fig.l.

During this upward movement of the lock handle 8, the second slope 18 on the lock handle 8 presses the push button block 20 which thereupon rotates slightly in the clockwise direction against the operation of the coil spring 22. As the lock handle 8 is registered at its locking position, the pawl 23 on the push button block 20 is again brought into engagement with the hook 19 on the lock handle 8. In this locking position, the push button block 20 is placed under influence by the coil spring 22 and the lock handle 8 is kept within the housing 1 shown in Fig. 1. Thereafter, the tumbler-key mechanism 14 is operated via the key 24 so that the key plate 15 is brought into engagement with the transverse pin 16. The lock handle 8 is now keyed to the housing 1.

In accordance with the present invention, locking and unlocking of the lock handle mechanism can be easily carried out by use of the lock handle of a monolithic construction.

Thus, the construction is much simplified and, as consequence, its production cost is much lowered.

Claims

CLAIMS:

1. A lock handle mechanism for an enclosure comprising: a housing; a lock shaft rotatably mounted on the housing; a locking means for sealing the enclosure fixed to a first end of the lock shaft; a lock handle pivotally mounted on a second end of the lock shaft; spring means urging the lock handle away from a first position relative to the housing; a key mechanism for locking the locking handle to the housing when the lock handle is in said first position; a push button block pivotally mounted on the housing and biased by further spring means such that in said first position a pawl on the push button block is in releasable latching engagement with said lock handle.

2. A lock handle mechanism as claimed in claim 1, wherein the lock handle is pivotally mounted at a first end to the lock shaft and is lockable to the housing by the key mechanism at a second end, and further comprising a pin fixed to the housing for sliding contact with the second end of the lock handle when the lock handle turns.

3. A lock handle mechanism as claimed in claim 2 wherein the second end of the lock handle has a first sloped section for sliding contact with the pin so as to push the second end of the lock handle towards the lock shaft when the lock handle is folded into the housing.

4. A lock handle mechanism as claimed in claim 2 or 3 wherein the second end of the lock handle has a second sloped section for sliding contact with the push button block to turn the push button block against the action of the further spring means.

5. A lock handle mechanism as claimed in any preceding claim, wherein the second end of the lock handle is provided with a hook whereby the latching engagement is made by engagement between the hook and the pawl when the lock handle is fully accommodated in the housing.

6. A lock handle mechanism as claimed in any preceding claim, wherein the locking means fixed to the first end of the lock shaft is a fixer disc arranged for engagement with a lock on the housing.

7. A lock handle mechanism as claimed in any preceding claim, wherein the spring means urging the lock handle away from the first position is interposed between the lock handle and the lock shaft.

8. A lock handle mechanism as claimed in any preceding claim wherein, in use, the first end of the lock shaft is at the back of the housing and the second end of the lock shaft is at the front of the housing, the lock shaft is situated at an upper part of the housing and in the first position the lock handle extends downwards.

9. A lock handle mechanism for an electric switchboard box comprising a housing, a lock shaft rotatably mounted to the upper section of the housing while extending from back to front in the housing, a fixer disc mounted to the rear end of the lock shaft in a arrangement engageable with a lock provided on the housing, a lock handle pivoted at its upper end to the front section of the lock shaft for vertical turning, a spring interposed between the lock handle and the lock shaft so as to urge the lock handle to turn forwards and upwards out of the housing, a key-mechanism mounted to the lower section of the housing in an arrangement engageable with the lower end of the lock handle, a transverse pin fixed to the housing for sliding contact with the lower end of the lock handle when the latter turns, a push button block pivoted to the housing below the lock handle and spring loaded for rotation towards the transverse pin, and a pawl formed on the push button block for engagement with the lower end of the lock handle.

10. A lock handle mechanism for an enclosure as described herein, with reference to the accompanying drawings.