Locking devices

A locking device for opening or closing a door comprising a lock housing having a pair of holes; a slider slidable within the lock housing; a pair of clamps, the base end being pivotally mounted on the front end of the slider, and the other end having a spring force acting outward; a spring member for the clamp attached to the front end of the slider; rails each provided on the outside of the pair of clamps in the lengthwise direction; a pair of rollers each having a circular shape, which can be fitted with each of the rails, and are supported to be revolved in adjacent to the holes of the lock housing; a spring member for the slider which is intervened between the lock housing and the slider and which applies a spring force to the slider in the direction forward to the hole of the lock housing; a heart-shaped groove carved in one side of the slider, having a plurality of differences in depth, and a recess provided on the bottom portion thereof; a projecting member, one end being slidable in the groove only in one direction, and the other end being formed on the lock housing; a spring member for the projecting member; a resilient member which reinforces the resiliency of the spring member for the projecting member; and a key unit which can be clamped by the pair of clamps is provided.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a locking device for opening or closing a 
door which is used in kitchen furniture and the like. 
2. Prior Art 
In conventional, there is a locking device for opening or closing a door, 
for example, as described in Japanese examined Utility Model Publication 
2-2857 (corresponding to U.S. Pat. No. 4,482,175). The locking device 
disclosed therein comprises a lock housing 36, having a case 38, formed in 
a cabinet A for kitchen furniture and a key unit 37 formed in a door B as 
shown in FIG. 4. The lock housing 36 and the key unit have the relation to 
be fitted with each other and to be released. The lock housing 36 of the 
cabinet A has a pair of holes formed in the surface thereof in which a 
slider which can be moved 40 is accommodated. At the front end of the 
slider 40, a pair of clamps 41 and 41 which can revolve are supported. A 
spring member (not shown) is provided so that it is applied to a spring 
force to open the front ends of the clamps 41 and 41 in a V-shape. At the 
same time, a heart-shaped groove 42 is provided on the side of the slider. 
A projecting member 43, one end of which slides within the slider only in 
one direction is provided, and the other end is formed on an appropriate 
position of the cabinet A, is applied to a spring force in the direction 
of groove 42 by a leaf spring 45. 
Consequently, when the door B in the closed state is opened, the clamps 41 
and 41, which are opened in the rear surface of the door in a V shape, are 
brought into contact with each other in the state where a spherical member 
47 of the key unit is intervened between the clamps. When the door B is 
further pushed toward the direction of the cabinet A, the clamps 41 and 41 
are guided by rollers 48 and 48 to be pushed inward. The clamps 41 and 41 
then revolve in the direction where the open ends thereof are closed, and 
they clamp the spherical member 47 and move toward the direction of the 
cabinet A. At this time, the front end of the projecting member 43 
residing within the heart-shaped groove is positioned at the recess via 
one side of the groove 42 to the top of the groove, and inhibits the slide 
of the clamps 41 and 41. The door B is locked on the cabinet A in this 
state. 
The locking device as described above in which the leaf spring 45 is used 
to apply a spring force to the heart-shaped groove is disadvantageous in 
terms of the durability in that when the number of using the lock device 
is increased, the resilient of the spring force becomes poor. 
Furthermore, when the door is further pushed, the front ends of the clamps 
41 and 41 are opened in a V-shape by a spring force of the spring provided 
on the base ends of the clamps 41 and 41 whereby the slider 40 and the 
clamps 41 and 41 move forward to release the locking state in the locking 
device disclosed therein. However, since the movement is due to the spring 
force of the spring provided on the base ends of the clamps 41 and 41, it 
is difficult to smoothly move the slider 40 and the clamps 41 and 41 
forward, and their actions tend to be slow. 
Moreover, it is difficult to correctly fix the spherical member 47 of the 
key unit in the door side at the position opposite to the lock housing 36 
and, thus, there is a tendency to have some gaps between the positions of 
the lock housing 36 and the key unit 37. 
SUMMARY OF THE INVENTION 
An object of the present invention is, therefore, to provide a locking 
device for opening or closing a door which can open or close a door only 
by pushing the door with one touch of one's finger, which has an enhanced 
durability, which acts smoothly, and which is composed such that even when 
some gaps are generated, they can be automatically corrected, whereby 
solving the problems associated with the prior art. 
The present invention, which has been achieved in light of the 
circumstances described above, relates to a locking device for opening or 
closing a door, which comprises a lock housing having a pair of holes 
formed in the front surface thereof; a slider which can slide within the 
lock housing; a pair of clamps, the base end of each of which is pivotally 
mounted on the front end of the slider, and the other end of each of which 
has a spring force acting outward; a spring member for the clamp attached 
to the front end of the slider such that said pair of clamps are opened in 
an approximately V-shape; rails each provided on the outside of said pair 
of clamps in the lengthwise direction; a pair of rollers each having a 
circular shape, which can be fitted with each of the rails, and are 
supported to be revolved in adjacent to the holes of the lock housing; a 
spring member for the slider which is intervened between said lock housing 
and said slider and which applies a spring force to said slider in the 
direction forward to the hole of the lock housing; a heart-shaped groove 
which is carved in one side of said slider, has a plurality of differences 
in depth, and a recess provided on the bottom portion of the heart shape; 
a projecting member, one end of which can slide in the groove only in one 
direction, and the other end of which is formed on an appropriate position 
of the lock housing; a spring member for the projecting member formed on 
the lock housing, which applies a spring force to said projecting member 
in the groove direction; a resilient which is intervened between the 
spring member for the projecting member and the lock housing and 
reinforces the resiliency of said spring member for the projecting member; 
and a key unit having a spherical member, which can be clamped by the pair 
of clamps. 
The locking device according to the present invention is also characterized 
in that said resilient is made of a synthetic resin. 
The locking device according to the present invention is also characterized 
in that the spherical member of the key unit can moved within a prescribed 
range in the direction perpendicular to the direction of the movement of 
the spherical member.

PREFERRED EMBODIMENTS OF THE INVENTION 
In the following, embodiments of the locking device according to the 
present invention will now be described by referring to the attached 
drawings. 
FIG. 1 is a perspective view showing one embodiment of a locking device 
according to the present invention, and FIG. 2 is an exploded view 
thereof. As shown in FIGS. 1 and 2, a locking device 1 for opening or 
closing a door comprises a locking housing 2 equipped on the side of a 
cabinet A and a key unit 3 equipped on the side of a door B. 
The lock housing 2 has a box case 5 made of a synthetic resin. The front 
surface of the case 5 is opened, and within the case 5 a slider 6 which 
can slide in the front and rear directions is stored. 
Dented portions 7 and 7 provided on the top and the bottom of the front end 
of the slider 6 are supported by the base ends of a pair of clamps 10 and 
10 which can vertically revolve. Hallow portions 10a and 10a are provided 
opposite to the front ends of the clamps 10 and 10. Rails 10b and 10b are 
provided along the rear surfaces of the clamps 10 and 10 over 
approximately entire length so that by a spring force of spring members 11 
and 11, the front ends of the both clamps 10 and 10 are opened 
approximately in the V-shape. 
Between pins 8 and 8 of the slider 6, the sharpened tip 12 having a 
triangle structure and the sharpened tip in the rear side is provided. On 
one side of either right or left of the slider 6 a groove 13 having a 
heart shape contour is carved. On a back of the heart-shaped groove 13, a 
slope 14 is provided. On the down side of the heart-shaped groove 13, a 
spring receiver is provided such that the front end is directed backward. 
On the upper and lower portions of the front end within the case 5, rollers 
17 and 17 are supported pivotally, and the rollers 17 and 17 have a 
annular grooves 17a and 17a in the middle position thereof. The annular 
grooves 17a and 17a can be fitted with rails 10b and 10b of the clamps 10 
and 10. When the slider is moved backward within the case 5, the slider 6 
pushes the clamps 10 and 10 from outward to inward at which the free end 
thereof is closed. 
The case 5 has an open hole 5a positioned at the front, a pair of holding 
portions 5b and 5b which are provided opposite to the heart-shaped groove 
13 of the slider 6 in order to hold a leaf spring 19 described latter on, 
a supporting member 5c for supporting a projecting member 20 which can 
revolve, a spring receiver 5d provided on the lower portion of the 
supporting member 5c whose top end is faced toward the front, and an 
insert hole 5e perforated at the rear end thereof for inserting a leaf 
spring 19. A coil spring 22 is compressed between the spring receiver 5d 
and the slider 6. 
The projecting member has a U-shape and possesses bent portions 20a and 20a 
at the both ends thereof. The bent portion 20a at one end is supported by 
the supporting member 5c for supporting a projecting member so as to 
freely revolve, and the bent portion 20a at the other end is always in 
contact with the heart-shaped groove by a spring force of the leaf spring 
19. 
The leaf spring 19 is cut to form a bent portion 19a having a rectangle 
shape. There is a triangle resilient member 24 made of silicone sandwiched 
between the bent portion 19b and the base of the leaf spring 19. 
The resilient member 24 plays a role in a cushion for the projecting member 
20 whereby the resiliency and durability of the leaf spring 190 can be 
significantly improved. The durability of the locking device can be 
improved approximately 10 times as compared with that having no resilient 
member. 
As shown in FIGS. 3A & 3B, the heart-shaped groove 13 is formed from a top 
portion 13a, a pair of slopes, i.e., a downward slope 13b and an upward 
slope 13c, a recess 13d which is a bottom of the slopes, and bottom 
portion 13e. There are differences in the depth from the rear end of the 
top portion 13a to the front end of the bottom portion 13e, from the top 
portion 13a to the downward slope 13b, from the downward slope 13b to the 
recess 13d, and from the upward slope 13c to the bottom portion 13e. There 
is no difference in depth between the recess 13d and the upward slope 13c. 
The depth in the bottom portion 13e is gradually decreased from the front 
end to the rear end. There is also difference in depth between the rear 
end of the bottom portion 13e to the rear end of the top portion 13a so 
that the depth in the bottom portion side is deep. Consequently, due to 
the differences in depth described above, the bent portion 20a of the 
projecting member can slide in the direction of from the top portion 13a, 
the downward slope 13b, the recess 13d, the upward slope 13c, the bottom 
portion 13e, to the top portion 13a, but it cannot slide in the reverse 
direction. 
On the other hand, as shown in FIGS. 1 and 2, a key unit 3 is mounted 
opposite to the lock housing 2 residing on the rear surface of the door B 
of kitchen furniture. The key unit 3 has a base plate 26 to be installed 
to the door B. The base plate 26 has a circular groove 26a at the center 
portion thereof. The circular groove 26a has a penetrating pore. Further, 
a disk 27 having a diameter smaller than that of the circular groove 26a 
is slidably fitted within the groove 26a of the base plate 26. A rod 28 
having a diameter smaller than the penetrating pore of the circular groove 
26a is mounted on the disk 27. On the front end of the rod 28, a spherical 
member 29 is fixed. Accordingly, the disk 27, the rod 28, and the 
spherical member 29 can be moved within the penetrating pore of the 
circular groove 26a, making it possible to automatically correct the 
position of mounting the key unit 3 and the lock housing 2, even if the 
positions to be communicated have some gaps. 
Next, the action of the locking device for opening or closing a door 
according to the present invention will be described by referring to FIGS. 
3A & 3B. 
FIG. 3 (A) shows the lock housing and the key unit which are opened. The 
slider 6 and the clamps 10 and 10 are at forward position by the action of 
the coil spring 22. The front ends of the clamps 10 and 10 are opened, and 
the bent portion 20a of the projecting member 20 resides at the portion 
backward to the top portion 13a of the heart-shaped groove 20. 
As shown in FIG. 3 (b), when the door B in the open state is closed, the 
spherical member 29 of the key unit 3 pushes the top end 12 of the slider 
6 thereby backing the slider 6 and the clamps 10. According to the 
movement, the rollers 17 and 17 pushes the clamps 10 and 10 from outward 
to inward to compress the open end thereby clamping the spherical member 
29 by the dented potions 10a and 10a. At the same time, the bent portion 
20a of the projecting member 20 slides to the recess 13d of the 
heart-shaped groove 13 via the top portion 13a and the downward slope 13b 
so that the bent portion of the projection member 20 is locked at the 
position of the recess 13d by a resilient force. In this case, the 
projecting member 20 is always applied to a spring force by the leaf 
spring 19 and the resilient 24. At the same time, since the slope 14 at 
the rear end of the slider 6 is in contact with the bent portion 19a of 
the leaf spring and is applied to a pressure, the projecting member 20 is 
more strongly applied to the spring force in the direction of the 
heart-shaped groove 13 by a resilient force of the leaf spring and the 
resilient 24. In this state, the door B is in locked state. 
On the other hand, since the disk 27, the rod 28 and the spherical member 
29 of the key unit 3 can slide perpendicular to the direction of the 
movement of the spherical member 29, it is possible to automatically 
correct the position of mounting the key unit 3 and the lock housing 2, 
even if the positions to be communicated have some gaps. 
When the door B in the closed state is further pushed, the bent portion 20a 
of the projecting member 20 is moved to the bottom portion 13e of the 
heart-shaped groove 13 via the recess 13d and the upward slope 13c. By the 
resilient force of the coil spring 22, the slider 6 and the clamps 10 and 
10 go forward. According to this movement, the front ends of the clamps 10 
and 10 are released to cancel the communication relationship with the 
spherical member 29, i.e., to cancel the locking and to return to the 
state shown in FIG. 3 (A) whereby the door B becomes an open state. In 
this case, the bent portion 20a of the projecting member 20 slides from 
the recess 13d of the heart-shaped groove 13 to the rear end of the top 
portion 13a via the upward slope 13c and the bottom portion 13e, and stops 
at this position. 
Consequently, the projecting member 20 is applied to a spring force in the 
heart-shaped groove direction by the leaf spring 19 and the resilient 24. 
The resilient 24 can significantly improve the resiliency and durability 
of the leaf spring 19. 
Moreover, since the coil spring 22 is intervened between the slider 6 and 
the case 5, the slider 6 and the clamps 10 and 10 can rapidly remove, 
making it possible to rapidly cancel locking. 
Whereas the locking device for opening or closing a door in the embodiment 
described above is applied to a door for kitchen furniture, the device of 
the present invention is, of course, applicable to another furniture. 
Whereas the locking housing and the key unit of the locking device in this 
embodiment are mounted in the vertical direction, they can be, of course, 
mounted in the horizontal direction. 
Further, while silicone is used as the resilient, another resilient such as 
synthetic resin or rubber is, of course, used as the resilient. 
As described above, according to the present invention, the projecting 
member is always applied to a spring force in the heart-shaped groove 
direction by the spring member for the projecting member. Since a 
resilient is intervened between the case of the lock housing and the 
spring member for the projecting member, by the use of the resilient, the 
resiliency and durability of the spring member for the projecting member 
can be significantly improved. 
Moreover, a spring member for the slider is intervened between the slider 
and the lock housing, the slider and the clamps can rapidly remove, making 
it possible to rapidly cancel locking. 
Further, the spherical member of the key unit can slide in the direction 
perpendicular to the vertical movement of the spherical member, it is 
possible to automatically correct the position of mounting the key unit 
and the lock housing, even if the positions to be communicated have some 
gaps.