Locking device for door

A device to lock a door body provided on a main body, wherein by a sliding body provided slidably on a framework attached to the inside of the door body and having such an operational mechanism as to be pushed within the framework by first pushing and to be protruded forwards by second pushing, a hook body provided turnably within the framework is protruded out of a window hole provided at one side of the framework so as to be engaged with and disengaged from the main body side. The sliding body has a knob at its outside.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a locking device for a door for a wardrobe 
or the like. 
2. Description of the Prior Art 
Various types of locking devices for wardrobes and the like have been used 
hitherto, but in every such device having an interior hook actuated to 
locking and unlocking positions by a customary handle, the device was 
comparatively large, and its operational mechanism was complex, making it 
troublesome and not suitable to be made at low cost. 
SUMMARY OF THE INVENTION 
The object of the present invention is to avoid these disadvantages. The 
invention is intended to provide simple and compact operational mechanism 
that operates easily and can be made at low cost. 
The door locking device of the present invention is characterized by 
comprising, in a locking device to lock a door, a housing attached to an 
inside surface of the door near a free end thereof and having a latch 
aperture in its one side adjacent to said edge of the door; a latch hook 
pivoted in the housing to swing between a latching position protruding 
from the housing through said aperture and a retracted position 
substantially wholly within the housing; a crank arm constrained to swing 
in unison with said latch hook and having a crank slot; a sliding body 
confined to forward and rearward sliding in said housing and yieldingly 
biased forwardly, said sliding body having a pin fixed thereon which is 
slidably engaged in said crank slot and which cooperates with the crank 
arm to translate rearward and forward movement of the sliding body into 
movement of the latch hook respectively towards its latching position and 
towards its retracted position, and said sliding body further having a 
substantially heart-shaped cam groove; and an operating rod substantialy 
confined against forward and rearward motion relative to the housing and 
having a portion engaged in said cam groove to so cooperate therewith that 
successive rearward actuations of said sliding body alternately establish 
it in a rearward locking position in which it holds the latch hook in its 
latching position and in a forward unlocking position in which it holds 
the latch hook in its retracted position. 
Other objects and characteristics of the present invention will be 
explained by referring to the drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
In FIG. 1, a box-shaped main body (1) opened at the front thereof comprises 
top wall (2), base wall (3), side walls (4) at both sides thereof and a 
rear wall (5). 
A door (6) is attached so as to be opened and closed freely by multiple 
hinges (7) at one of its edges, and a locking device (8) is provided 
adjacent to one of the free edges of the door, in this case its edge 
opposite the hinged one. 
This locking device (8) will be explained with reference to FIG. 2 and the 
following figures. 
In the figures, a synthetic resin housing (11) having flat walls (12) is 
open at its front and has a latch aperture (13) in its side wall nearest 
its adjacent edge of the door (6). Through-holes (14) are formed in the 
upper and lower walls of the housing (11), and bearing parts (15) of 
semi-circular arc-shape are formed at the inside of the housing in line 
with the upper and lower through-holes (14). A pair of sliding-guide 
plates (16) are formed within the housing (11) at its side opposite the 
latch aperature (13), having inner edge portions that define fore-and-aft 
extending guide rails (17). And, a support (18) protrudes toward the open 
side from the center of the inner bottom part within the housing (11). 
Further, flanges (19) project up and down from the respective upper and 
lower parts of the open side of the housing (11) and a plurality of 
attaching holes (20) are bored in these flanges (19). Further, a plurality 
of engaging recesses (21) for a cover body are formed on the inner face at 
both sides of the open side of the housing (11). 
A synthetic resin cover (31) is attached to the open front side of the 
housing (11). A square-shaped, through-hole (32) is formed in this cover 
body (31), and an annular forwardly protruding wall (33) is provided on 
the outer face of the cover body (31) surrounding the through-hole (32). 
Semi-circular arc shaped bearing parts (43) are formed at one side of the 
inner face of the cover body (31), each opposed to a bearing part (15) of 
the housing (11), and a support piece (35) positioned between the pair of 
sliding-guide plates (16), protrudes rearward from the other side of the 
cover body (31). An operating rod supporting part (36) is provided at the 
tip end part of this support part (36). Further, engaging projections 
(37), each corresponding to an engaging recess (21) of the housing (11), 
protrude from both end faces of the cover body (31). Thus the cover body 
(31) is fitted and fixed to the open side of the housing (11) by engaging 
each engaging projection (37) in the engaging recess (21) of the housing, 
and the support piece (35) is inserted between base parts of one pair of 
sliding-guide plates (16), and the bearing parts (15), (34) are positioned 
in opposed relation. 
A latch hook body (41) is made of metal and received within the housing 
(11), and this latch hook body (41) has a cylindrical shaft part (42) 
corresponding to the bearing parts (15), (34) of the housing (11) and 
cover body (31). An inserting hole (44) that has a flat (43) along one 
side is formed within this shaft part (42). A latch hook (45) protrudes 
from the intermediate part of the shaft part (42), projecting to one side 
of it, and a crank arm (46) protrudes from the upper end of the shaft part 
(42), projecting laterally from it in a direction substantially 
perpendicular to that of the hook (45). The tip end part of this crank arm 
(46) is bent slightly toward the hook (45), and a crank-slot (47) is 
formed along the center line of the crank arm (46). Further, the shaft 
part (42) of the hook body (41) is rotatably supported by the bearing 
parts (15), (34) of the housing (11) and the cover body (31), and the 
latch hook (45) thus swings to and from a latching position in which it 
protrudes out of the latch aperture (13) of the housing (11). 
A square-pillar shaped sliding body (51) is formed from synthetic resin to 
be inserted within the housing (11), and it has a thread part (53) that 
protrudes forward from its front end to project out of the housing (11) 
and through the through-hole (32) of the cover body (31). A knob (54) 
positioned within the annular wall (33) of the cover body (31) is screwed 
to this threaded part (53). Further, a crank pin (55) inserted slidably 
into the crank-slot (47) of the crank arm (46) protrudes at a corner on 
the upper face of the sliding body (51), near its rear end, and a stopper 
(56) that cooperates with the rear or inner face of the cover body (31) 
protrudes from the lower face of the sliding body (51). 
A substantially heart-shaped cam groove (57) is provided in the side face 
of the sliding body (51) that faces the support piece (35) on the cover 
body (31). This cam groove (57) comprises a first guide groove (58) which 
becomes gradually shallower in depth towards the front end of the sliding 
body (51), a second guide groove (59) which is connected with the forward 
end of the first guide groove (58) and is slightly deeper than the depth 
at the front end of the first guide groove (58), a third guide groove (60) 
which is connected with the second guide groove (59) and is slightly 
deeper than the depth of the second guide groove (59), and a fourth guide 
groove (61) which extends rearwards from the front end of the third guide 
groove (60). At its rear end the fourth guide groove (61) is connected 
with the first guide groove (58) a short distance forward of the rear end 
of the latter; and its depth at its front end is slightly greater than the 
depth of the guide groove (60) but it becomes progressively shallower from 
there and its depth at its rear end is slightly less than the depth of the 
guide groove (58) where it joins the latter. A base part of an operating 
rod (62) made of metal is rotatably supported on the supporting part (36) 
for the operating rod (62) on the support piece (35) of the cover body 
(31), and a follower part (63) at the tip end of the operating rod (62) is 
slidably received in the cam groove (57). This follower part (63) is urged 
toward the bottom of the cam groove (57) by spring force of the operating 
rod (62), and the follower part (63) slides successively from the 
shallower groove to the deeper groove within each guide groove (58), (59), 
(60), (61) as the sliding body (51) slides forward and rearward in the 
housing (11). The sliding body (51) is fitted slidably between the guide 
parts (17) of the pair of slide guide plates (16) and between the bearing 
parts (15) within the housing (11), and its front or outer end protrudes 
out of the cover body (31) through its through-hole (32). A coil spring 
(64) fitted to the support (18) in the housing is inserted into a spring 
receiving hole (52) in the sliding body (51) that opens to the rear end 
thereof. The spring (64) maintains a forward bias on the sliding body 
(51). An operating mechanism (65) for the sliding body (51) is thus formed 
by the cam groove (57), the operating rod (62) and the spring (64). 
Thus, the cover body (31), latch hook body (41) and sliding body (51) are 
received in the housing (11), which is arranged on the inner face of the 
door (6), and the knob (54) attached to the sliding body (51) is received 
within a hole (9) formed in the door-body (6). Further, a cylindrical 
cap-body (10) receives the knob (54) is fitted into the hole (9). 
Upper and lower hook bodies (71) of synthetic resin each have a cylindrical 
shaft part (72) which has a medial part (73) of reduced diameter. The 
cylindrical shaft part (72) is further provided with an inserting hole 
(75) having flat (74) along one side, corresponding to inserting hole (44) 
of said latch hook body (41). A hook (76) protrudes laterally from at the 
end of the shaft part (72). 
There is provided an intermediate bearing (77) of synthetic resin, and an 
inserting hole (78) is formed at the center of this intermediate bearing 
(77). The medial portion (79) of this bearing has a reduced outside 
diameter. 
Upper and lower connecting shafts (81) of metal each have a flat side (82) 
corresponding to the flats (43), (74) of the inserting hole (44) of the 
latch hook body (41) and the inserting holes (75) of the upper and lower 
hook bodies (71). 
The connecting shafts (81) are inserted into the inserting hole (44) of the 
latch hook body (41) and, extending through the througholes (14) in the 
housing (11), are received in the inserting holes (75) in the upper and 
lower hook bodies (71). The flats (82) on the connecting shafts (81) 
cooperate with the flat surfaces (43) and (74) in the hook bodies (41) and 
(71) to constrain those hook bodies to swing in unison about the 
coinciding axes of the shafts (81). 
Further, at least one of the intermediate bearings (77) is fitted onto each 
connecting shaft (81), which extends through its inserting hole (78), 
between the housing (11) and the upper and lower hook bodies (71), when it 
is necessary. 
For each of the upper and lower hook bodies (71) there is a bearing body 
(83) of synthetic resin, housing a base plate (84) in which there are 
attaching holes (85). A circular arc-shaped support part (86) 
corresponding to the inserting part (73) of the hook body (71) protrudes 
from one side of the base plate (84) and has therein an inserting opening 
(87) of smaller diameter than the inserting part (73) is of the hook body 
(71). 
A keeper (88) of synthetic resin cooperates with the latch hook (45). The 
keeper (88) has a cup shaped body (89) which is provided with a flange 
(90) around its open end and which has circumferentially extending 
corrugations or serrations (91) on its periphery. 
The housing (11) is attached onto the inner face of the door (6) by screws 
(101) through the attaching holes (20) of its flanges (19) as described 
above, and the knob (54) is arranged within the hole (9) in the door (6). 
The cooperating shaft (81) extends in the vertical direction. The bearing 
body (83) is arranged at the upper and lower parts of the door body (6), 
fixed by screws (102) through the attaching holes (85) in its base plate 
(84). The fitting parts (73) of the upper and lower hook bodies (71) are 
fitted into the resilient support part (86) of each bearing body (83) by 
being snapped into its inserting opening (87). Thus, the upper and lower 
hook bodies (71) are supported at prescribed positions. Further, when the 
intermediate bearing (77) is used, a bearing body (83) is attached also at 
its position, and the support part (86) is fitted into its fitting part 
(79). 
Further, in the inner face part of the side wall (4) at said one side, the 
keeper (88) is arranged in a position to receive the latch hook (45), the 
keeper body (89) being secured by the engagement of its corrugations (91). 
Further, there is a lock pin (103) for each of the upper and lower hook 
bodies (71), and those lock pins (103) respectively project from the lower 
face of the top wall 2 and the upper face of the bottom wall (3). 
Next, operation of the device will be explained. 
When the door body (6) is open relative to the main body (1), the knob (54) 
projects forward beyond the front face of the door (6) through the hole 
(9) in the door (6), and at the same time, the sliding body (51) is also 
projects partway out of the housing (11), urged by the coil spring (64) to 
have its front portion extend through the through-hole (32) in the cover 
body (31) and into the hole (9) in the door (6). At this time, the 
engaging part (63) of the operating rod (62) is positioned within the rear 
end part of the first guide groove 58 at the rear end of the heart-shaped 
cam groove (57). When the knob (54) is pushed in by the finger against the 
biasing force of the coil spring (64), the sliding body (51) is pushed 
rearward into the housing (11) by sliding, and at the same time, the 
follower part (63) of the operating rod (62) falls into the second guide 
groove (59). As the finger is released here, the follower part (63) slides 
up to the third guide groove (60) from the second guide groove (59) since 
the sliding body (51) is pushed forward relative to the door (6) by the 
coil spring (64). The rear end of the second guide groove (59) thus 
cooperates with the follower part (63) and the spring (64) to maintain the 
sliding body (51) in a locking position in which it is just sightly 
forward of its rear limit of sliding motion. As the knob (54) is pushed by 
the finger again, the follower part (63) of the operating rod (62) enters 
the fourth guide groove (61) from the third guide groove (60), and as the 
finger is released here, the sliding body (51) sides forward relative to 
the door (6) and is partway out of the housing (11) to a forward unlocking 
position. At the same time, the follower part (63) of the operating rod 
(62) moves into the first guide groove (58) from the fourth guide groove 
(61) and is engaged within the rear end part of the first guide groove 
(58), that is, within the protruding end of the heart shaped groove. 
As the sliding body (51) slides into and partway out of the housing (11), 
the crank pin (55) on the sliding body (51) swings the latch hook body 
(41) through the crank arm (46). When the sliding body (51) is in its 
forward position in the door (6) the latch hook (45) of the hook body (41) 
is retracted through the latch aperture (13) of the housing (11), so that 
its engagement with the keeper (88) is released. As the sliding-body (51) 
is pushed rearward into the housing (11), the latch hook (45) of the hook 
body (41) is swung to project out of the latch aperture (13) and is 
engaged with the keeper (88) whereby it assumes its locking state. 
Further, with turning of the latch hook body (41), the upper and lower hook 
bodies (71) are turned through the upper and lower cooperating shafts (81) 
to be engaged or disengaged, as the case may be, from the lock pins (103). 
According to the present invention, when the sliding body is moved by 
pushing on the knob 54 at the hook bodies are turned by cooperation of the 
crank arm with the crank pin in the crank-slot, to thereby operate the 
hooks. At the same time the upper and lower hook bodies are operated 
through the cooperating shaft. Thus the construction of the device is 
simple and it can be arranged to be. It can be made at a low price, and 
further its operation is extremely easy since the hook bodies may be 
turned by merely pushing the sliding body.