GB2304370A

GB2304370A - Lock device

Info

Publication number: GB2304370A
Application number: GB9517052A
Authority: GB
Inventors: Ching-Hua Chiang
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-08-19
Filing date: 1995-08-19
Publication date: 1997-03-19
Anticipated expiration: 2015-08-19
Also published as: GB2304370B; GB9517052D0

Abstract

A latch 36 for engaging an electrical outlet box (not shown) to hold its door closed, is fixed to a rotatable rod 14 secured to a pin 21 received in elongate slots 29 in a release lever 20 which is pivotable on the pin 21 from a fully closed position in a housing 10 (in which it is lockable by a lock 30) via a partially open position (Figure 6) to a fully open position in which rotation of the rod 14 and the latch 36 is possible. The release lever 20 accommodates a cam member 25 engaging the housing 10 so as to allow axial movement of the rod 14 away from the housing 10 under the bias of a spring 19, to permit a square plate 17 fixed to the rod 14 to lift clear of recesses 16 in a guide 15 fixed to the housing 10. A further spring 28 urges the tail 27 of the cam member 25 away from a plate 24 in the lever 20.

Description

LATCH DEVICE FOR AN ELECTRIC OUTLET BOX The invention relates to a latch device for an electric outlet box.

Typical electric outlet boxes comprise a door for enclosing the boxes and including a latch rotated by a bolt in order to latch the door. However, the latch is forced to engage with the box and may cause a great friction with the box such that the box and the latch will be easily damaged. In addition, the latch may be easily opened by the children such that the children may be hurt by the electricity inadvertently.

The invention is to provide a latch device which may lock the door in place and which may reduce friction between the latch device and the box.

FIG. 1 is an exploded perspective view of a latch device for an electric outlet box; FIGS. 2, 3, 4, 5 are cross sectional views illustrating the operations of the latch device; and FIGS. 6, 7, 8 are perspective views, corresponding to FIGS. 3, 4, 5 respectively, for illustrating the operation of the latch device.

Referring to FIGS. 1 and 2, a latch device comprises a housing 10 including a depression 11 formed in the front and upper portion and including an orifice 12 for engaging with a rod 14. The housing 10 is secured to the door of the typical electric outlet box.

A guide 15 is fixed in the rear portion of the housing 10 and is engaged on the rod 14 and includes four notches 16. The guide 15 may be secured to the housing 10 by molding processes. A plate 17 is fixed on the rod 14 and includes four bulges 18 for engaging with the notches 16 of the guide 15. A spring 19 is biased between the guide 15 and the plate 17 for biasing the plate 17 away from the guide 15. A latch 36 is fixed on the rod 14 and is rotated in concert with the rod 14.

A knob 20 includes a cavity 22 and includes a pair of oblong holes 29 for engaging with a shaft 21 such that the knob 20 is rotatable about the shaft 21. The shaft 21 is secured to one end of the rod 14 such that the knob 20 is rotatable relative to the rod 14. A frame 23 is fixed to the knob 20 and includes two oblong holes 29 for engaging with the shaft 21, and includes a wall member 24. The frame 23 may be secured to the knob 20 by molding processes. A cam member 25 includes two holes 26 for rotatably engaging with the shaft 21 and includes a stop 27 extended inward of the knob 20. The cam member 25 is engaged with the housing 10. A spring 28 is biased between the wall member 24 and the stop 27 for biasing the shaft 21 to engage with one end of the oblong holes 29.

A lock member 30 is secured in the lower portion of the housing 10 and a plate 32 is secured to the lock housing 10 by a number of fastening screws 31 so as to secure the lock member 30 within the housing 10. The lock member 30 includes a catch 35 provided therein for engaging with the cavity 22 of the knob 20 so as to lock the knob 20 in place, and includes a cam 38 secured on the core 37 and rotated in concert with the core 37 such that the cam means 38 can be rotated by the core 37 in order to actuate the catch 35 to engage with the cavity 22 of the knob 20 (FIGS. 1 and 4). A bracket 33 may be secured to the housing 10 by a screw 34 so as to secure the housing 10 to the typical electric outlet boxes.

Referring again to FIG. 2, the stop 27 is biased by the spring 28 such that the shaft 21 engaged with the holes 26 will be biased to engage with one end of the oblong holes 29 which is located close to the guide 15. At this moment, the bulges 18 of the plate 17 are engaged with the notches 16 of the guide 15 such that the plate 17 and the rod 14 may be prevented from rotating relative to the housing 10.

However, as shown in FIGS. 3 and 6, when the upper portion of the knob 20 is depressed inward of the housing 10 by the users, the shaft 21 may move to the other end of the oblong holes 29 relatively when the upper portion of the knob 20 is depressed inward of the housing. At this moment, the lower portion of the knob 20 may thus be moved outward of the housing 10 and may be fetched by the users.

Referring next to FIGS. 4 and 7, when the knob 20 is rotated about the shaft 21, the cam member 25 may be arranged such that the plate 17 may be disengaged from the guide 15 by the spring 19. At this moment, the bulges 18 of the plate 17 are disengaged from the notches 16 of the guide 15 such that the rod 14 and the plate 17 may be rotated relative to the housing 10 and such that the latch 36 may be rotated by the knob 20 and may be rotated to the position as shown in FIGS. 5 and 8, in order that the latch 36 may be disengaged from the electric outlet box and in order that the door of the electric outlet box is allowed to be opened.

When the knob 20 is rotated inward of the depression of the housing 10 from the position as shown in FIGS. 4 and 7 to the position as shown in FIG. 2, the plate 17 may be moved to engage with the guide 15 against the spring 19, and the latch 36 may be moved toward the housing 10 in order to engage with the electric outlet box and so as to lock the door of the electric outlet box in place.

In addition, as shown in FIG. 2, the catch 35 of the lock 30 may engage with the cavity 22 of the knob 20 so as to lock the knob 20 in place and so as to prevent the knob 20 from being opened by the children inadvertently and so as to avoid the children from being hurt by the electric shocks.

Claims

CLAIMS:

1. A latch device comprising: a housing including an upper portion having an orifice formed therein and including a front and upper portion having a depression formed therein, a rod engaged through said orifice of said housing and including a first end and a second end, a shaft secured to said first end of said rod, a latch secured to said second end of said rod and rotated in concert with said rod, means for biasing said latch away from said housing, a knob including a first end portion having at least one oblong hole formed therein for engaging with said shaft, said knob including a second end portion, said oblong hole including a first end arranged close to said latch and including a second end located distal to said latch, a cam means engaged on said shaft and engaged with said housing, and means for biasing said shaft to engage with said first end of said oblong hole, said first end portion of said knob being moved inward of said depression of said housing in order to disengage said second end portion of said knob from said housing, said latch being biased away from said housing when said second end portion of said knob is disengaged from said housing, and said latch being moved toward said housing when said second end portion of said knob is moved inward of said depression of said housing.

2. A latch device according to claim 1, wherein said housing includes a guide secured to a rear portion and having at least one notch, said rod includes a plate having at least one bulge for engaging with said notch of said guide so as to prevent said rod and said knob from rotating relative to said housing.

3. A latch device according to claim 1, wherein said housing includes a lower portion, said knob includes a cavity formed in said second end portion, said latch device comprises a lock means secured in said lower portion of said housing and including a catch means for engaging with said cavity of said knob so as to lock said knob in place.

4. A latch device substantially as herein described with reference to the accompanying drawings.