U.S. patent number 3,709,537 [Application Number 05/008,614] was granted by the patent office on 1973-01-09 for door locking device.
This patent grant is currently assigned to Aisin Seiki Kabushiki Kaisha. Invention is credited to Kenichi Kazaoka, Nozomu Torii.
United States Patent |
3,709,537 |
Kazaoka , et al. |
January 9, 1973 |
DOOR LOCKING DEVICE
Abstract
A striker of ring shape fixed to a doorway engages and rotates a
disk latch rotatably supported on a corresponding door into a
striker locking position when the door is closed, and the latch is
thus held by a semicylindrical end of a detent having a cylindrical
body, the semicylindrical end and cylindrical body being snugly but
rotatably supported against transverse force respectively by
semicylindrical and cylindrical concavities formed in a part
supported on the door. When the latch is in the striker locking
position, the striker is in a position substantially intermediate
between the axes of the latch and the detent.
Inventors: |
Kazaoka; Kenichi (Kariya,
JA), Torii; Nozomu (Kariya, JA) |
Assignee: |
Aisin Seiki Kabushiki Kaisha
(Kariya-shi, JA)
|
Family
ID: |
26344220 |
Appl.
No.: |
05/008,614 |
Filed: |
February 4, 1970 |
Foreign Application Priority Data
|
|
|
|
|
Feb 8, 1969 [JA] |
|
|
44/9474 |
Feb 9, 1969 [JA] |
|
|
44/12379 |
|
Current U.S.
Class: |
292/216;
292/DIG.41 |
Current CPC
Class: |
E05B
77/02 (20130101); E05B 85/243 (20130101); E05B
77/18 (20130101); Y10T 292/1047 (20150401); Y10S
292/41 (20130101) |
Current International
Class: |
E05B
65/32 (20060101); E05B 65/20 (20060101); E05c
003/24 () |
Field of
Search: |
;292/216,198,210,3,4,280 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Moore; Richard E.
Claims
We claim:
1. A door locking device for locking a door in a doorway frame of a
motor vehicle comprising, a striker fixed to said doorway frame, a
base plate fixed to the door, a cover plate fixed to the base
plate, a main body of synthetic resin fixedly provided between the
base plate and the cover plate, said main body having a recessed
portion of a concave cylindrical bearing surface, a latch member
rotatably supported on said main body for movement about an axis
extending longitudinally of the vehicle, said latch member being
adapted to engage with and be rotated into a striker locking
position by said striker when the door is closed, a detent
rotatably mounted in the recessed portion of said main body for
movement about an axis parallel to the axis of the latch member,
said detent being rotatably operated by portions of the periphery
of said latch member to catch and lock the latch member in said
locking position and being operable to release the latch member, an
outer periphery of said detent being backed up by said concave
cylindrical bearing surface of the main body against forces
transverse to the rotational axis of the detent, and a door
unlocking mechanism for operating the detent to release the latch
member and when a force adapted to disengage the engagement of the
striker with the latch member is imparted in the locking position,
the force is received by the concave cylindrical bearing surface
through the peripheral surface of the detent.
2. The door locking device as claimed in claim 1 in which said
striker locked by said latch member in said locking position is in
a position substantially intermediate between the rotational axes
of the latch member and said detent.
3. A door locking device for locking a door in a doorway frame of a
motor vehicle comprising, a striker fixed to said doorway frame, a
latch member rotatably supported on said door for movement about an
axis extending longitudinally of the vehicle, said latch member
being adapted to engage with and be rotated into a striker locking
position by said striker when the door is closed, a detent
rotatably mounted on the door for movement about an axis parallel
to the axis of the latch member, said detent having a configuration
which in at least one part thereof constitutes a part of a circular
cylinder, said circular cylinder part of the detent being rotatably
operated by portions of the periphery of said latch member to catch
and lock the latch member in said locking position and being
operable to release the latch member, a part supported on the door,
said door supported part having a concave cylindrical bearing
surface for rotatably backing up said detent against forces
transverse to the rotational axis thereof, and a door unlocking
mechanism for operating the detent to release the latch member and
when a force adapted to disengage the engagement of the striker
with the latch member is imparted in the locking position, the
force is received by the concave cylindrical bearing surface
through the peripheral surface of the detent, said detent having a
fully circular cylindrical part and said concave cylindrical
bearing surface being a fully cylindrical concavity snugly
accommodating said fully circular cylindrical part of the detent,
and a part circular cylindrical concavity snugly contacting said
circular cylindrical part of the detent over a substantial surface
thereof without contacting the latch member at any position
thereof.
4. The door locking device as claimed in claim 3 in which said
latch member is of planar form, the axis of which is the axis of
rotation thereof, and being substantially perpendicular to the
direction of motion of the latch member relative to the striker,
and being substantially parallel to the axis of said detent, and
the latch member having a slot extending substantially radially
outward to an open end at the periphery of the latch member with
said slot being adapted to engage and receive therein the
striker.
5. A latch mechanism for a door of a motor vehicle body, including
a striker fixed to the vehicle body and a rotary latch member, a
recessed body of synthetic resin in which said rotary latch member
is mounted, said body having a slot for receiving the striker, said
rotary latch member including an integral pivotal mounting portion
rotatable in a bore in the body, and a detent rotatably mounted in
the recessed body to engage the latch member in the same plane as
the slot for receiving the striker.
6. The latch mechanism as claimed in claim 5, in which the pivot
point of the latch member is located at the opposite side of the
engagement point between the detent and the latch member relative
to the striker.
Description
BACKGROUND OF THE INVENTION
This invention relates to door locking devices and more to a new
door locking device for doors of motor vehicles.
In recent years, automobile traffic accidents have increased,
resulting in an unfortunate increase in death or fatal accidents.
In many cases, deaths are due to accidental doors opening or caused
by shock of collision of cars. In view of this situation, it is
deemed very important as a safety measure to increase the breaking
strength or resistance to accidental unlocking of door lock
devices.
As is known, when an abnormally great breaking force is imparted to
a vehicle door locking device of prior design, at the time of a
collision, for example, mutual engaging parts of a striker and
latch element, a pivoted part of the latch element, auxiliary
engaging parts of the latch element and detent means for stopping
the turning of the latch element, and a pivoted part of the detent
means are especially apt to be damaged or broken.
SUMMARY OF THE INVENTION
It is an object of the present invention to increase the mechanical
strengths of these parts which are subject to damage, particularly
the above mentioned auxiliary engasing parts of the latch element,
stopping means, and pivoted part of the detent means, merely by
rationally designing the configuration and organization of these
parts, without any inordinate enlargement of parts or of the entire
locking device assembly, with particular consideration being given
to the feasibility and economy of fabrication of these parts with
high precision.
Another object of the invention, in a general aspect thereof, is to
provide a door locking device of the above stated character which
is of simple construction and operation, capable of being
manufactured and maintained at low cost, and easily operated by
hand with a comfortable, pleasant tactile sensation.
In general, the present invention contemplates the provision of a
door locking device for vehicles which has the following functional
features.
1. Keeping the door in a closed state (when the door is closed, but
is still unlocked).
2. Permitting the door (which is in the state mentioned in 1) to be
opened both from inside and outside of the car.
3. Locking from inside of the car for safety or protection against
theft.
4. Locking by use of a key from outside of the car for protection
against theft.
5. Automatic release of locking when the door is closed after the
locking operation has been carried out from inside of the car by
mistake (to avoid locking when the key is left behind in the
car)
6. Locking without use of the key (keyless locking, -- this is
desired, for example, on rainy days)
According to the present invention, briefly summarized, there is
provided a door locking device characterized by the combination of
a striker fixed to a doorway frame for receiving a door, a latch
member rotatably supported on the door and adapted to engage with
and be rotated into a striker locking position by the striker when
the door is closed, a detent having a configuration which, in at
least one part thereof, constitutes a part of a cylinder and
rotatably supported on the door, the detent being rotatably
operated by the latch member to catch and lock the latch member in
the locking position and being operable to release the latch
member, a concave cylindrical bearing surface formed in a part
supported on the door for rotatably backing up the detent against
transverse forces, and an unlocking mechanism for operating the
detent to release the latch member, with the position of the
striker in the locked position being substantially intermediate
between the axis of rotation of the latch member and the axis of
rotation of the detent.
Now, the present invention will be described in detail with respect
to a preferable embodiment thereof and with reference to the
accompanying drawings, in which like parts are designated by like
reference numerals.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a front view of a door locking device according to an
embodiment of the present invention, in which a cover plate is
removed to show a door lock and a striker, with these two being
completely out of engagement;
FIG. 2 is a front view similar to as FIG. 1, but showing the state
when the door lock and the striker are fully engaged;
FIG. 3 is a fragmentary sectional view along the line III--III in
FIG. 2;
FIG. 4 is a view of the device shown in FIG. 1 from its rear side,
and shows an embodiment of an operating mechanism in its unlocked
position;
FIG. 5 is a view similar to FIG. 4, but showing the operating
mechanism in locked position;
FIG. 6 is a fragmentary front view indicating the relationship
between a main engaging part and an auxiliary engaging part in a
door locking device of prior design; and,
FIG. 7 is a fragmentary vertical section, showing an undesirable
state of engagement when the device shown in FIG. 6 is subjected to
a load in the longitudinal direction of the vehicle.
DETAILED DESCRIPTION
In the drawings reference character A designates a door-lock
according to the invention attached to a side panel C (FIG. 3), B
designates a striker, which being secured to a door-post D (FIG.
3), keeps the door in a closed state when engaged with the
door-lock A and includes a base plate B.sub.1 secured to the post D
and a locking ring B.sub.2 engageable with the lock A.
As shown in FIG. 3, the door-lock consists principally of a cover
plate 7, a main body 1 and base plate 6 and is fixed to a side
panel of said door as a unit by fixing means such as bolts. The
body 1 is formed from synthetic resin, having depressions 1a, 1b,
1c, 1d and 1e, one of which 1d is elongated in a horizontal
direction (from right to left as viewed in FIG. 1) at a position
spaced appropriately downwards from the turning axis of a latch 2
(to be described below), and opens to the left as viewed in FIG.
1), so that the locking ring B.sub.2 of the striker is permitted to
enter into or move out of this depression.
Further (FIG. 3), in the cover plate 7 and in the side panel C,
there are provided slots such as 7a of similar shapes as the
depression 1d for the entrance and extraction of the striker into
and out of the locking ring B.sub.2. A pin (pivot) 2a (FIG. 1),
forming the turning axis of the latch 2, is pivotably supported in
the depression 1e at the middle part of the body 1, i.e., the latch
2 is pivoted in this depression 1e of the body 1 turnably about the
pin 2a.
In the latch 2, outside of the pin 2a (FIG. 1), there is formed an
open-ended slot 2b, which is shaped to engage with the ring B.sub.2
and to be turned by the latter into positions of "safety
engagement" and "full engagement," when the leading side of the
locking ring B.sub.2 (of the striker), enters into the depression
1d through the slot 7a of the cover plate 7 and a slot C.sub.1 of
the side panel C when the door is closed and to be forced by the
ring B.sub.2 to turn in the opposite direction when the door is
opened. When the door is opened, this slot 2b has its opening
aligned with the depression 1d of body 1 and its bottom against the
center of the pin 2a, as shown in FIG. 1. Further, the latch 2 is
provided with a pin 4, which is being urged to turn clockwise about
the pin 2a by a coiled compression spring 5 located in the
depression 1c of arcuate shape and arranged between the pin 4 and
the bottom of this depression 1c.
In the depression 1b of cylindrical shape formed in the periphery
(outer boundary) of the depression 1a of the body 1, a locking
detent 3 is snugly and rotatably received and has a crescent
(semi-circular) cross section defined by a part of circular wall 3a
concentric with the axis of rotation of the detent 3 and a vertical
wall 3b. The circular or arcuate wall 3a is adapted to engage
selectively with a first tooth 2c (for safety engagement) or a
second tooth 2d (for full engagement) formed on the periphery of
the latch 2, with these teeth 2c and 2d being defined by a convex
surface opposite the surface of the circular wall 3a, a concave
surface having a radius of curvature greater than that of the wall
3a, or a flat plane. The second tooth 2d is formed at the
counterclockwise side (as seen in FIG. 1) of the open end of slot
2b, while the first tooth 2c is formed in the periphery of the
latch 2 at a point forward counterclockwise from that of the tooth
2d.
Further, the periphery of the latch 2 at the counterclockwise side
of the first tooth 2c, through a certain distance starting from the
latter, is formed into a inclined slope 2e, which is suitable for
engaging the vertical wall 3b of the detent 3 so as to turn the
same in the clockwise direction, and a peripheral part 2f between
the tooth 2c and the tooth 2d is also inclined in the same way. An
axially projecting pin 3c (FIG. 3) is pivotably supported by the
base plate 6 of the door-lock, with the pin 3c at its free end
being fixed to the middle part of an open plate 8. Accordingly, the
locking detent 3 is pivotably supported by fitting with the base
plate 6 and with the aforesaid cylindrical depression 1b, while the
detent 3 and the open plate 8 are caused to move unitarily.
An example of an operating mechanism suitable force in this
invention will now be described. FIG. 4 shows the unlocked state,
i.e., the state in which the release button (not shown in the
drawings) is pushed and the door is permitted to be opened by being
pulled in the opening direction. A generally T-shaped open-lever 12
is, at its middle part, pivotably secured to the base plate 6 by
means of a pin 13. The lever 12 has a first arm 12a at its left
side. The free end of the arm 12a has a connecting lever 15 pivoted
thereto by means of a pin 14. The lever 12 also has a second arm
12b at its right side, which extends through a slot 6b formed in a
vertical plane 6a bent into the front side (the nearer side as
viewed in the drawing) of the base plate 6, with the purpose of
this slot 6b being to limit the motion of the lever 12.
The lever 12, further, has an upward extending arm 12c, which is
related to the action of the release button when the latter is
pushed in from outside to open the door. Between an anchor 12d and
a hole 6e provided in the vertical plane 6a of base plate 6, there
is placed a spring 23, which urges the lever 12 to turn clockwise
about the pin 13. A locking plate 16 is pivotably secured at its
middle part, the lower part (in the drawings) of by the pin 3c, and
at the upper side (viewer's side of FIG. 4) of the plate 16, and T
shaped open plate 8 is fixed to the pin 3c. The locking plate 16 at
its right end 16a (seen in FIG. 4) extends through a slot 6c formed
in the vertical plane 6a, with the slot 6c serving to limit the
swinging motion of the plate 16 about the pin 3c.
In the locking plate 16 adjacent its righthand end 16a, there is
provided a hole 16b, which is to be connected with an inside
locking member, such as an inside push knob, (not shown in the
drawings), which serves to keeps the door in the locked position,
i.e., the position in which the door cannot be opened by pushing in
the open button or by pulling the door in opening direction. At the
lefthand end of the horizontal part of the plate 16 there is
provided a hole 16c, which is to be connected to a member (not
shown in the drawings) operated by the action of a key. The plate
16 has an arm 16d, which extends upwardly from between the hole 16c
and the pin 3c and has a pin 20 fixed thereto. Moreover, in the
plate 16 there is formed a hole 16e between the hole 16b and the
pin 3c, and, between the hole 16e and a hole 6h formed in the base
plate 6, there is installed a turn-over spring 24.
The above-mentioned pin 20 fixed to the locking plate 16 is snugly
received in a groove formed by a hook shaped part 15a of the
connecting lever 15. A tension spring 19 is provided between a hole
8a formed in the open plate 8 and a spring anchor 6d formed in the
base plate 6 and has the function of urging the plate 8 in the
clockwise direction, while a stopper 6g provided on the base plate
6 is in engagement with the first (lower) arm 8b of the plate 8,
for limiting the clockwise turning of the latter.
The second arm 8c of the open plate 8, which extends from the plate
to the left in FIG. 4, is bent toward the viewer's side (in FIG. 4)
at its left end. Owing to such arrangement, when the open-lever 12
turns in the counterclockwise direction, and the connecting lever
15 is moved downward as viewed in the drawing, the second arm 8c is
engaged with the lower end of the lever 15, causing the open plate
8 to turn in the counterclockwise direction about the pin 3c. A top
end 8d of the open plate 8 extends to a height at which the end 8d
can engage the hook shaped part 15a of the connecting lever 15 and
is bent at a right angle toward the viewer's side of the drawing
(see FIG. 3). As shown in FIG. 3, in the right hand end of the
vertical plane 6a of the base plate 6, there is pivoted an inside
open lever 21 to the plane 6a by means of a pin 22, which lever 21
is engageable at its left end (engaging part) 21a with the second
arm 12b of the open lever 12.
The device of the above described organization according to this
invention operates as follows.
When the door is in its open state, the latch 2 and the detent 3
are positioned as shown in FIG. 1. When the door is closed, the
striker B enters into the slot 2b along the depression 1d of the
body 1, and by engaging the second tooth 2d of the latch 2, causes
the latter to turn in the counterclockwise direction. At this time,
the latch 2, contacting the vertical wall 3b of the detent 3,
causes the latter to turn in the clockwise direction(seen in FIG.
1) against the force of the spring 19 until the first tooth 2c of
the latch 2 is brought into engagement with the circular peripheral
wall 3a of the detent 3 (safety engagement).
After the continued movement of the door toward the closed
position, the second tooth 2d of the latch 2 is brought into
engagement with circular wall 3a of the detent 3 (full engagement),
and, the latch and the detent are held in this state.
In this closed state, which is shown in FIGS. 2 and 3, if the
opening button (for opening the door) is operated in the opening
direction, the release arm 12c of the open lever 12 is shifted to
the left in FIG. 4, causing the lever 12 to turn in the
counterclockwise direction. As a result, the connecting lever 15 is
forced downwards in the drawing along the pin 20, whereby the
second arm 8c of the open plate 8 is pushed downward, causing the
plate 8 to turn about the pin 3c in the counterclockwise direction
as seen in FIG. 4. By this turning, the locking detent 3 is also
turned in the clockwise direction as seen in FIG. 1, resulting in
releasing of engagement between the detent 3 and the first or
second tooth 2c or 2d of the latch 2. Consequently, the latch 2 is
allowed to turn in the clockwise direction as seen in FIG. 1 under
the action of the spring 5, until the open end of slot 2b comes
into alignment with the slot 7a of cover plate 7 and with the
depression 1d of body 1. In this position (which is shown in FIG.
1), the striker B is released from engagement with the latch 2, and
the door is allowed to be opened.
In the closed state of the door, if an inside open handle is
operated to the opening direction, the inside open lever 21 is
turned in the clockwise direction in FIG. 3 about the pin 22,
causing the engaging part 21a of the lever 21 to lift the second
arm 12b of open lever 12 upward (as seen in FIGS. 3 and 4) so as to
turn the lever 12 in the counterclockwise direction about the pin
13. Thus, the same effect as described above (when the outside
opening button is operated) is attained, and the door is allowed to
be opened in the same way.
When the door is locked from outside by using a key, the locking
plate 16 is turned in the clockwise direction about the pin 3c
through a lever(not shown) connected to the hole 16c of locking
plate 16. When it is desired to lock the door from inside, the
locking plate 16 is caused to turn in the clockwise direction about
the pin 3c by, for example, pushing down an inside locking push
knob connected to the hole 16b of locking plate 16. In either case,
the pin 20 fixed to locking plate 16 is simultaneously turned in
the same direction about the pin 3c, forcing the lower end of
connecting lever 15 to the right as seen in FIG. 4, until the lever
15 takes a position as shown in FIG. 5 by full lines. When the
mechanism is in this state, the turn-over spring 24, which has been
previously urging the locking plate 16 in the counterclockwise
direction, begins to urge the same plate in the clockwise
direction.
In the position shown in FIG. 5, if the opening button or the
inside opening handle is operated and the open lever 12 is turned
in the counterclockwise direction to a position shown by dotted
lines in FIG. 5, the connecting lever 15 will be moved downward to
a position as shown by other dotted lines. In this case however,
the lower end of lever 15 cannot engage with the second arm 8c of
open plate 8, and, consequently, the open plate 8 being left
unmoved, and the door is not allowed to open, i.e., the door is
kept in locked state.
When the door is closed, and the inside locking push-knob is kept
in locking position, i.e., the locking plate 16 is kept in the
position shown in FIG. 5, by mistake, the striker B engages the
latch 2, thus causing turning of the latter, and the slope 2e
behind the first tooth 2c of latch 2 forces the detent 3 to turn in
the clockwise direction as indicated in FIGS. 1 and 2 until the
latch and the detent come into safety or full engagement. By this
turning of the latch 2 (and by the resulted turning of the detent
3), the open plate 8 is caused to turn in the counterclockwide
direction as seen in FIG. 5, the third arm 8d of which pushes the
hook-shaped part 15a of connecting lever 15, thus causing the
latter to turn in the clockwise direction about the pin 14. The pin
20 is thereupon pushed to the left by engagement with the part 15a,
causing the locking plate 16 to turn in the counterclockwise
direction as seen in FIG. 5 about the pin 3c and positions the
plate 16 so as to be kept in the position shown in FIG. 4 under the
action of turnover spring 24. Thereafter, the door is allowed to be
opened by operation of the opening button, followed by clockwise
turning (seen in FIG. 4) of open-lever 12 about the pin 13. That
is, the unlocking function is attained.
On the other hand, when it is desired to accomplish keyless
locking, the inside locking push-knob is operated to position the
locking plate 16 and the connecting lever 15 is locking position as
shown in FIG. 5 by full lines. Then, after the opening button is
operated in the opening direction (i.e., with the parts as
positioned in dotted-line positions in FIG. 5), the door is closed.
In this case, counterclockwise turning of the open-plate 8 caused
by closing of the door cannot change the position of connecting
lever 15, since the third arm 8d of open-plate 8 cannot engage with
the hook-shaped part 15a of connecting lever 15. Therefore, the
lever 15 is left unmoved in the position shown in FIG. 5. Thus,
once the door is closed, it is not permitted to open, even if the
open-handle is operated, and in this way keyless locking (locking
without use of the key) is attained.
The particular advantages given by the present invention are as
follows. In door lock devices of the prior art, as shown in FIG. 6,
there is provided a latch 32, which has ratchet teeth 32c and 32d
engageable with a detent or pawl 33 for stopping the turning of the
latch at one side of a pivot point 32a of the same, and a claw 32b
engageable with a striker Ba at the opposite side of the pivot
point. In other words, the prior device has a force-acting point
and a reaction point at opposite sides of a pivot point, while the
device of the present invention has a reaction point and a pivot
point at opposite sides of a force-acting point.
Therefore, when the same force P acts on the force-acting point
(assuming that the distance between the pivot point and the
reaction point is equal to that between the force-acting point and
the pivot point in the case of the prior device, and that the
distance between the force-acting point and the reaction point is
equal to that between the force-acting point and the pivot point in
the case of the device of the present invention), the pivot point
is subjected to a force of 2P and the reaction point to a force of
P.sub.1 in the case of the prior art device, while in the case of
the device of the present invention, a force of only 1/2P acts on
both the pivot point and the reaction point. Accordingly, in the
device of the present invention, the latch teeth and the detent are
capable of bearing with the same sizes two or four times greater
forces than in the prior art design. Moreover, when the force along
the longitudinal direction of the car acts upon these parts, there
is an undesirable tendency in the case of the prior art design of
the latch 32 disengaging from the pawl 33 as indicated in FIG. 7.
In the case of the present invention, however, as the parts are
arranged as shown in FIG. 3, disengagement of the latch 2 from the
detent 3 is restricted by the cover plate 7, so that the correct
performance is further ensured in spite of the longitudinal
deformation of the car.
Furthermore, the detent 3 is basically a body of revolution, a part
of which is cut-out and is shaped to have its arcuate periphery 3a
engageable with the the first or second tooth 2c or 2d of the latch
2. Accordingly the detent 3 is formed readily from an ordinary
material such as a cold-rolled round bar by rather simple machining
at low cost. The surface of this detent is not necessarily
machine-finished but, when finished by cutting or grinding, there
is attained an excellent smoothness of its engagement with the
first or second tooth 2c or 2d of the latch 2. Consequently, a very
comfortable tactile feeling is provided in the unlocking operation
which is far beyond the reach of prior art devices, in which the
parts are formed by pressing or the like.
Moreover, when the configurations of latch teeth 2c and 2d are
defined by convex planes opposing the peripheral arcuate surface 3a
of detent 3, concave planes having greater radii of curvature than
the surface 3a, or by flat planes, it becomes possible to maintain
a component of a force to open the door always directed toward the
center of the detent 3, irrespective of small errors in
manufacturing or assembling. Therefore, occurrence of unintended
disengagement between the latch teeth and the detent, due to the
abovesaid errors accompanying deformation caused by the torque of
the acting force, as is the case of the prior art design, is
completely eliminated, whereby the advantageous features of the
present invention are assured.
Still further, in the present invention, because the detent is
rotatably supported at and along its outer face instead of being a
pawl pivoted by a pin as in the case of the prior art, it is
possible to make the support surface with a great diameter whereby
great strength of the part is assured.
It is to be noted that, in the abovedescribed embodiment there is
used as the detent a cylindrical member having a cut-out part.
However, as will be appreciated, the same effect is obtainable by
using a disk-shaped detent having a cut-out part and pivotably
suspended at its outer face.
Generally speaking, in the present invention, when an attempt is
made to open or force open the door, a force transmitted from the
striker is divided into two components by the latch, and each of
these components is received by one or another of two members,
respectively. By using a latch of this type together with a detent,
which is shaped from a cylindrical or disk like material by cutting
out a part thereof and is rotatably supported in a depression of a
complementary shape, there is provided a novel door locking device
which is of simple design, low cast, and great strength, and
imparts a comfortable tactile feeling in operation.
While the invention is herein shown and described as embodied in a
preferred form of construction, it is to be understood that various
modifications may be made in both the structure and arrangement of
the parts of the device without departing from the spirit or scope
of the invention. Thus, for example, the engaging part (arcuate
wall) 3a of locking detent 3 can be made hook-shaped if
desired.
* * * * *