Double locking vehicle door latch

A vehicle door latch assembly including a lock mechanism actuatable between a locked and unlocked condition and providing a double locking feature. The lock mechanism includes a first locking member adapted to selectively rotate about a first axis between locked and unlocked positions respectively corresponding to the locked and unlocked conditions of the latch mechanism. A second locking member is provided which is adapted to rotate about the first axis adjacent to the first locking member. The first and second locking members may be selectively coupled and uncoupled. When coupled, the second locking member may be selectively rotated about the first axis to move the first locking member between the locked and unlocked positions. When uncoupled, the first locking member is operable to move between the locked and unlocked positions independently of the second locking member. A control member is moveable axially to couple the first and second locking members. The control member is provided with a cam surface which cooperates with another cam surface on a gear to produce the axial movement of the control member required for coupling and uncoupling of the first and second locking members.

BACKGROUND OF THE INVENTION 
This invention relates in general to electrically actuated latch assemblies 
and in particular to an improved structure for an electrically actuated 
vehicle door latch providing a double locking feature. A cam on a rotating 
actuator gear creates an axial movement in a control member to uncouple 
selected locking members from a latch mechanism and thereby lock the door 
latch. 
Vehicles such as passenger cars are commonly equipped with individual 
latches which secure respective passenger and driver doors. Each latch is 
typically provided with an individual mechanical lock which may be key 
operated from the exterior of the vehicle and provided with manual means 
for operating inside the vehicle, e.g., a respective sill button. Further, 
these locks are commonly provided with a means for remote operation, such 
as an electrically operated mechanism for actuating the lock. 
As is commonly known, the lock may be actuated to lock the door and prevent 
unlatching of the door. An occupant of a vehicle may lock the doors 
thereof, for example, to prevent entry into the vehicle by an unauthorized 
individual while the vehicle is at rest. The terms "latching" and 
"unlatching" as used herein refer to the acts of, respectively, securing a 
door closed and freeing the door so it can be opened. "Locking" and 
"unlocking" are used to refer to the act of actuating a lock mechanism to 
respectively prevent and permit unlatching of the door. 
It has been found desirable to provide these locks with a so-called 
anti-theft or double lock feature. When activated, such a feature disables 
the interior manual operating means for the lock. The exterior operating 
means requires a key to be operated, and the electric operating means may 
be tied into an electronic vehicle security system to prevent unauthorized 
operation. In this condition, a thief who gains entry into the vehicle by, 
for example, breaking a window cannot unlock the vehicle door. A vehicle 
thus equipped is therefore a less attractive target for thieves. 
SUMMARY OF THE INVENTION 
This invention relates to an improved structure for a vehicle door latch 
assembly including a lock mechanism actuatable between a locked and 
unlocked condition and providing a double locking feature. The lock 
mechanism includes a first locking member adapted to selectively rotate 
about a first axis between locked and unlocked positions respectively 
corresponding to the locked and unlocked conditions of the latch 
mechanism. A second locking member is provided which is adapted to rotate 
about the first axis adjacent to the first locking member. The first and 
second locking members may be selectively coupled and uncoupled. When 
coupled, the second locking member may be selectively rotated about the 
first axis to move the first locking member between the locked and 
unlocked positions. When uncoupled, the first locking member is operable 
to move between the locked and unlocked positions independently of the 
second locking member. A control member is moveable axially to couple the 
first and second locking members. The control member is provided with a 
cam surface which cooperates with another cam surface on a gear to produce 
the axial movement of the control member required for coupling and 
uncoupling of the first and second locking members. 
Various objects and advantages of this invention will become apparent to 
those skilled in the art from the following detailed description of the 
preferred embodiment, when read in light of the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
In the following description of the invention, certain terms will be 
utilized for the purpose of reference only and are not intended to be 
limiting. The terms "upward", "downward", "above", "below", "rightward", 
"leftward", "clockwise", and "counterclockwise", and words of similar 
import refer to directions in the drawings to which reference is made. 
Similarly, relational terms such as "inner" and "outer" are in reference 
to the geometric center of the component under discussion, unless another 
reference point is specifically designated. 
Referring now to the drawings, there is illustrated in FIGS. 1, 2, and 3 a 
latch assembly, indicated generally at 10. The latch assembly 10 includes 
a latch mechanism, indicated generally at 12, and an actuator mechanism, 
indicated generally at 14. 
The latch mechanism 12 has a U-shaped base plate 16, which is adapted to be 
secured to the edge of a motor vehicle door (not shown). The base plate 16 
includes a planar central portion 18. A pair of flanges 20 and 21 extend 
upwardly from two opposed marginal edges of the central portion 18. A pair 
of stops 20a and 20b are formed in the flange 20, the purpose of which 
will be explained below. An aperture 22 is formed through the central 
portion 18 and the flange 20 of the base plate 16 in the form of a 
laterally extending notch whose inside edges converge inwardly relative to 
the central portion 18. The aperture 22 is adapted to engage a striker 
bolt 24, which is secured to a door post 26 of the vehicle. 
A rotor pivot 28 is fixed perpendicularly to the base plate 16 near the 
aperture 22. A locking fork or rotor 30 pivotally mounted on the rotor 
pivot 28. The rotor pivot 28 is provided with an enlarged head portion 
which retains the rotor 30 on the rotor pivot 28. The rotor 30 is provided 
with a pair of arms 32 and 33 which engage the striker bolt 24 when the 
door is latched in a manner which is well known in the art. A rotor spring 
34 engages the rotor 30 and an aperture in the base plate 16 to urge the 
rotor 30 to rotate counterclockwise. The arm 32 is formed with a 
projection 36, the purpose of which will be explained below. 
A pawl pivot 38 is fixed perpendicularly to the central portion 18 of the 
base plate 16 near the rotor pivot 28. A pawl 40 is pivotally mounted on 
the pawl pivot 38, and includes a projection 42 which can engage the 
projection 36 in the rotor 30. As will be further described below, the 
pawl 38 may be rotated clockwise to free the projection 42 from the 
projection 36 on the rotor 30, and allow the latch mechanism 12 to open. 
The pawl 40 further includes a notch 43 formed in the perimeter thereof, 
the purpose of which will be explained below. 
A lock member pivot 44 is fixed to the base plate 16 near the pawl pivot 
38. The lock member pivot 44 defines a rotational axis perpendicular to 
the central portion 18 of the base plate 16. An outwardly extending flange 
46 is formed about the middle portion of the lock member pivot 44. A pawl 
spring 48 is mounted on the lock member pivot 44 between the base plate 16 
and the flange 46. The pawl spring 48 engages both the pawl 40 and an 
aperture in the base plate 16 to urge the pawl 40 to rotate 
counterclockwise, thus urging the projection 42 of the pawl 40 toward the 
rotor 30. 
An interior lock member 50 is pivotally mounted on the lock member pivot 44 
above the flange 46. The interior lock member 50 includes a generally disc 
shaped body 52 having an outwardly extending arm 54. Opposed notches 56 
are formed in the body 52 at right angles to the arm 54, for a purpose 
which will be discussed later. An aperture 58 is provided at the outer end 
of the arm 54 to permit connecting the interior lock member 50 with a 
linkage operatively connected to the interior door lock operator, such as 
a sill button (not shown). Operation of the sill button will cause the 
interior lock member to rotate about the rotational axis defined by the 
lock member pivot 44. The body 52 and arm 54 of the interior lock member 
define a plane which is perpendicular to the rotational axis of the lock 
member pivot 44. 
An exterior lock member 60 is also pivotally mounted on the lock member 
pivot 44, above the interior lock member 50. The upper end of the lock 
member pivot 44 is preferably peened over after the exterior lock member 
60 is mounted thereon, providing an enlarged head to retain the exterior 
lock member 60 and the interior lock member 50 on the lock member pivot 44 
(as shown in FIG. 6). The exterior lock member 60 includes a disc shaped 
body 62. The body 62 defines a plane perpendicular to the rotational axis 
of the lock member pivot 44. The body 62 is preferably provided with a 
downwardly extending boss 64 about a central aperture therein. The boss 64 
serves to space the body 62 of the exterior lock member 60 axially apart 
from the interior lock member 50 on the lock member pivot 44, as most 
clearly illustrated in FIG. 6. A pair of opposed notches 66 are formed in 
the perimeter of the body 62, the purpose of which will be discussed 
below. 
Between each of the notches 66 on the perimeter of the body 62 is an arm, 
integrally formed on the body 62 of the exterior lock member 60. A first 
arm 68 extends radially outwardly from the body 62. The arm 68 is provided 
with a tab 70. The tab 70 extends downwardly into the plane defined by the 
body 52 and the arm 54 of the interior lock member 50. The purpose of the 
tab 70 will be described below. The end of the arm 68, outward of the tab 
70, is bent upwardly to form a step 72. The portion of the arm 68 which is 
outward of the step 72 is provided with an aperture 74. This arrangement 
facilitates connection of the exterior lock member 60 to a linkage 
operated by the exterior door lock cylinder (not shown). 
A second arm 76 extends from the body 62 opposite the first arm 68. As seen 
from above the arm 76, such as in the overhead plan view of FIG. 2, the 
second arm 76 is formed with two clockwise right angles 76a and 76b. Thus 
an end portion 78 of the arm 76 runs substantially parallel to the first 
arm 68. An aperture 80 is formed in the free end portion 78 above the pawl 
pivot 38. Additionally, an upward step 82 is formed in the second arm 76 
between the the right angle 76a and the right angle 76b. The step 82 
elevates the end portion 78 of the arm 76 to provide clearance for the 
second arm 76 to move above the components mounted on the pawl pivot. The 
arm 76 also includes a spur portion 83 extending radially outwardly from 
the first right angle 76a of the second arm 76. An aperture 83a is formed 
in the spur portion 83a, the purpose of which will be explained below. 
A link pivot 84 is fixed in the aperture 80, and extends downwardly, 
perpendicular to the lower surface of the second arm 76. An elongate link 
member 86 is provided with apertures 88 near each end thereof. The link 
member 86 is pivotally mounted on the link pivot 84, which extends through 
a first one of the apertures 88. The free end of the link pivot 84 is 
provided with an enlarged head portion to retain the link member 86 on the 
link pivot 84. A downwardly extending link pin 90 is fixed in the the 
other one of the apertures 88 in the link member 86. The free end of the 
link pin 90 extends downwardly into the path of rotation of the pawl 40 
and may be selectively engaged by the notch 43 in the pawl 40 for a 
purpose which will be later described. 
A release member 92 is mounted on the pawl pivot 38, above the pawl 40, and 
is pivotable between a normal position (shown in, for example, FIG. 2) and 
an unlatch position (shown in FIG. 9). The release member 92 is provided 
with a longitudinally extending slot 94, through which the link pin 90 of 
the link member 86 passes. As will be further described below, the slot 94 
permits the link pin 90 to move longitudinally relative to the release 
member 92, while capturing the link pin 90 for rotation with the release 
member 92. The release member 92 is provided with upwardly extending 
flanges 96 at either end thereof. The flanges 96 facilitate operatively 
connecting the release member 92 to the latch release linkages (not shown) 
operated by the exterior and interior door handles (neither are shown). 
A first end of an over-center spring 98 is seated in an aperture formed in 
the central portion 18 of the base plate 16. The other end of the 
over-center spring 98 is received in the aperture 83a formed in the spur 
83 on the exterior lock member 60. The over-center spring 98 acts under 
compression to urge the exterior lock member 60 toward contact with the 
closer of the stop 20a or the stop 20b during rotation of the exterior 
lock member 60. The over-center spring 98 acts to keep the exterior lock 
member 60 in the desired position when the latch assembly 10 is not being 
operated. 
As will be further described below, the actuator mechanism 14 allows the 
locking members 50 and 60 of the latch mechanism 12 to be remotely power 
operated to lock and unlock the latch mechanism 12. The actuator mechanism 
14 is contained within a housing 100, which is mounted by conventional 
means (not shown) to the base plate 16. The housing 100 may be 
conventionally formed from, for example, a molded plastic material. Edge 
walls 102 extend upwardly at the periphery of a central portion 104 to 
increase the stiffness of the housing 100, and to enclose the components 
mounted within the housing 100. An opening 106 is formed through the 
central portion 104, and is axially aligned with the lock member pivot 44 
of the latch mechanism 12. An upwardly extending collar 108 is formed 
about the opening 106. An annular quad O-ring seal 110, formed of a 
suitable elastomeric material, is seated on the collar 108 for a purpose 
which will be described below. 
A sector gear 112 is pivotally mounted on the collar 108. As is most 
clearly shown in FIG. 4, the sector gear 112 is generally triangular in 
outline, having an opening 114 formed therethrough in a first corner 116. 
The arcuate side 118 opposite the first corner 116 defines a radius about 
the opening 114 in the sector gear 112. A gear tooth rack 120 is formed on 
the lower surface of the sector gear 112. An arcuate channel 122 is formed 
into the upper surface of the sector gear 112. The profile of the channel 
122 includes a relatively shallow portion 124 and a relatively deep 
portion 126. An inclined surface 128 extends between the shallow portion 
124 and the deep portion 126 of the channel 122. An upwardly extending 
ridge 129 is formed on the shallow portion 124 of the channel 122, 
adjacent to the inclined surface 128. A first stop block 130 is provided 
on the upper surface of the sector gear 112 at one end of the channel 122, 
adjacent to the shallow portion 124 thereof. A second stop block 131 is 
provided on the upper surface of the sector gear at the other end of the 
channel 122, adjacent to the deep portion 126 of the channel 122. 
Preferably the stop blocks 130 and 131 are integrally formed with the 
sector gear 112. The purposes of the varied profile of the channel 122 and 
of the stop blocks 130 and 131 will be discussed below. The sector gear is 
preferably molded of a heat resistant plastic material. 
A pin 132 is fixed perpendicularly to the upper surface of the sector gear 
112, between the opening 114 and the first corner 116. A spring anchor 
post 134 is fixed perpendicularly to the central portion 104 of the 
housing 100 near the first corner 116 of the sector gear 112. A centering 
spring 136 is stretched between the pin 132 and the spring anchor post 134 
and fastened thereto. The centering spring 136 urges the sector gear 112 
to rotate to a position in which the centering spring 136 is least 
stretched, which occurs when the sector gear 112 is in a centered 
position. Therefore, the centering spring 136 acts to urge the sector gear 
112 to rotate to its centered position. 
A control member 138 is mounted on the sector gear 112 so as to rotate and 
move axially upwards and downwards relative to the sector gear 112. As 
will become apparent, the control member 138 should be formed of a 
material which is relatively rigid, with good wear and torque transmitting 
properties. One suitable material is believed to be a powdered metal, 
although other materials will also be suitable. The control member 138 
includes a barrel shaped body 140. The body 140 extends downwardly through 
the opening 114 of the sector gear, the collar 108, and the opening 106 in 
the housing 100. The quad O-ring seal 110 enages the body 140 to provide a 
leak-tight seal between the body 140 of the control member 138 and the 
collar 108. Thus the quad O-ring seal 110 helps to exclude any metallic 
wear particles from the latch mechanism 12 or other contaminants from 
entering the housing 100 containing the actuator mechanism 14. 
As best seen in FIGS. 5 and 6, two fingers 142 extend downwardly from from 
the body 140. Each finger 142 has an arcuate cross section, as best seen 
in FIG. 7. As will be further explained below, the control member 138 can 
be selectively moved between the lowered position illustrated in FIGS. 5 
and 8, and a raised position illustrated in FIG. 18. When the control 
member 138 is moved axially downwards to the lowered position thereof, 
each of the fingers 142 is disposed to engage a respective one of the 
notches 66 in the exterior lock member 60, and one of the the notches 56 
in the interior locking member 50. Thus, when the actuator member 138 is 
in the lowered position thereof, the fingers 142 of the control member 138 
couples the exterior and interior lock members, 60 and 50, to rotate 
together. 
As will be further explained later, the control member 138 may be moved 
axially upwardly to a raised position, as illustrated in FIG. 18. In this 
raised position, the fingers 142 are disengaged from the interior lock 
member 50, but continue to engage the exterior lock member 60. In the 
raised position, therefore, rotation of the interior lock member 50 
clockwise (away from engagement with the tab 70) will not cause the 
exterior lock member 60 to rotate. As will be explained below however, the 
tab 70 extends into the plane of rotation of the interior lock member 50, 
and is used to vertically re-align the interior lock member 50 with the 
exterior lock member 60. 
A recess 144 is formed in the upper axial face of the control member 138, 
for a purpose which will be described below. The control member 138 
further includes arm 146 extending radially outward from the upper portion 
of the body 140. A flange 148 extends downwardly from the free end of the 
arm 146 into the channel 122 formed in the sector gear 112. The bottom 
surface of the flange 148 is bifurcated, with an upwardly inclined ramp 
150 shown on the left in FIG. 5. The ramp 150 is adapted to cooperate with 
the inclined surface 128 within the channel 122 of the sector gear 112 in 
a manner which will be described below. Note that the ramp 150 and the 
inclined surface 128 are preferably cooperating helical surfaces, rather 
than planar surfaces. Cooperating helical surfaces maximize the mutual 
contact area on each and more evenly support the loads transmitted 
therebetween as the sector gear 112 rotates relative to the actuator 
member 138, thereby minimizing wear of these surfaces. 
A lug 152 is formed on the radially outer surface of the flange 148. The 
bottom surface of the lug 152 is divided into three sections including a 
horizontal central bottom surface 154, and ramps 156 and 158. The ramps 
156 and 158 are inclined upwardly from the central surface 154 of the lug 
152 to the left and right, respectively, of the central bottom surface 
154, as seen in FIG. 5. The purpose of the lug 152 and the ramps 156 and 
158 will be explained below. 
A coil spring 160 is seated in the recess 144 formed in the top surface of 
the body 140 of the control member 138. The spring 160 is compressed 
between the control member 138 and a cover 161 (a portion of which is 
shown in FIGS. 6, 3, and 18) fixed over the housing 100 to urge the 
control member 138 axially downward toward the lowered position thereof. 
As will be further discussed below, the spring 160 cooperates with the 
control member 138 to define a control structure for selectively coupling 
the exterior lock member 60 to the interior lock member 50 for rotation 
therewith. 
A D.C. electric motor 162 is mounted within the housing 100. The motor 162 
is adapted to be electrically energized by a control circuit 163 (FIG. 2) 
in either direction of rotation. The control circuit is entirely 
conventional and contains elements to receive operator input (for example, 
by means of a pushbutton), and to electrically energize the motor 162 to 
cause rotation in a desired direction for a predetermined amount of time. 
The motor 162 drives the sector gear 112 to rotate in clockwise and 
counterclockwise directions through a gear train which includes a motor 
pinion 164. A shaft 165 adjacent to the motor pinion 164 has a driven gear 
166 fixed thereto for rotation with the shaft 165. Additionally a driven 
gear pinion 168 is also fixed to the shaft 165 for rotation therewith. The 
motor pinion 164 meshes with and drives the driven gear 166. Rotation of 
the driven gear 166 causes the shaft 165 and the driven gear pinion 168 to 
rotate therewith. The shaft 165 is journalled at the ends thereof in 
mounts 169 in a conventional manner. The rotating driven gear pinion 168 
meshes with the gear tooth rack 120 of the sector gear 112, causing the 
sector gear 112 to rotate relative to the base plate 16. Each of the gears 
in the gear train from the motor 162 to the sector gear 112 is preferably 
molded of a suitable plastic material. Normally, the electric motor 162 
will be operated only infrequently and thus it will remain relatively 
cool. However, during unusual periods of frequent demand, the electric 
motor 162 may heat up. Any heat which may be produced by operation of the 
electric motor 162 will be relatively confined within the housing 100. 
Therefore, it may be desirable for all of the components contained within 
the actuator 14, including the housing 100 itself to be formed of suitable 
heat resistant materials. 
A plate 170, preferably formed of a stamped metal, is fixed to the housing 
100. The plate 170 is formed with an inwardly extending arcuate slot 172 
which generally lies on a radius about the axis of rotation defined by the 
locking member pivot 44. A tab 174 extends outwardly from the plate 170 
toward the axis of rotation defined by the locking member pivot 44. The 
arm 146 is generally free to move relative to the plate 170. However, the 
lug 152 on the free end of the arm 146 must pass either above the tab 174 
(when the control member 138 is in the upper position thereof) or below 
the tab 174 (when the control member 138 is in the lowered position 
thereof) when the control member 138 is rotated. The purpose of the tab 
174 will be further described below. Additionally, stop blocks 176 are 
fixed to the lower surface of the plate 170 which limit the freedom of the 
sector gear 112 to rotate about the collar 108 to a relatively small arc, 
for a purpose which will be further described below. Note that it will be 
apparent to those of ordinary skill in the art that the stop blocks 176 
may be mounted on other portions of the latch assembly 10 other than the 
plate 170, such as on the housing 100, or that other means may be provided 
to limit the movement of the sector gear 112. 
The operation of the latch assembly 10 will now be described. Referring to 
FIGS. 2 and 3, the latch assembly 10 is shown in an unlocked, latched 
condition. That is, the striker bolt 24 is captured within the notch 22 in 
the base plate 16 by the leg 32 of the rotor 30, thus preventing the door 
post 26 from moving away from the base plate 16 and preventing the door 
from opening. The rotor 30 is prevented from rotating to release the 
striker post by the projection 42 on the pawl 40, which engages the 
projection 36 on the arm 32 of the rotor 30. The latch mechanism 12 is 
unlocked, as may be seen by the positioning of the pin 90 in the notch 43 
on the pawl 40. In this position, the pin 90, which extends through the 
slot 94 in the release member 92 couples the pawl 40 to the release member 
92 for rotation therewith. The interior lock member 50 is coupled for 
rotation with the exterior lock member 60 by the fingers 142 of the 
control member 138, which is in the lowered, unlock position thereof. The 
center spring 136 holds the sector gear 112 in the center position 
thereof. 
To open the vehicle door when the latch assembly 10 is in the unlocked and 
latched condition illustrated in FIGS. 2, 3, and 8, the user will actuate 
the interior or exterior door release mechanisms by means of an operating 
button or handle (not shown). This will cause the linkage of the selected 
release mechanism to act against the associated flange 96 of the release 
member 92, causing the release member 92 to rotate clockwise to the 
unlatch position shown in FIG. 9. As the release member 92 rotates, the 
pin 90 is driven into the side of the notch 43 in the pawl 40, causing the 
pawl 40 to rotate clockwise against the urging of the pawl spring 48. The 
link member 86 pivots about the link pivot 84 to accommodate the relative 
motion between the release member 92 and the exterior lock member 60. As 
the pawl 40 rotates, the projection 42 on the pawl 40 is disengaged from 
the projection 36 on the rotor 30. This allows the spring 34, together 
with any force exerted by the user on the door and transmitted through the 
latch bolt 24, to rotate the rotor 30 counterclockwise to release the 
latch bolt 24 from the aperture 22 in the base plate 16. The vehicle door 
is then free to open. The user can then release the interior or exterior 
door release mechanism handle, which will spring return to the unactuated 
position thereof. This allows the release member 92 and the pawl 40 to be 
driven by the pawl spring 48 back to their respective unactuated 
positions, shown in FIGS. 2 and 3. 
When the vehicle door is closed, the latch bolt 24 reenters the aperture 22 
and strikes the arm of the rotor 30, causing the rotor 30 to rotate 
clockwise. The arm 32 of the rotor will strike the projection 42 on the 
pawl 40, causing the pawl 40 to rotate clockwise until the projection 36 
of the arm 32 on the rotor 30 is rotated past the projection 42. The pawl 
40 will then rotate counterclockwise under the urging of the pawl spring 
48, causing the projection 42 to catch behind the projection 36 on the arm 
32 of the rotor 30, capturing the striker bolt 24. The latch assembly 10 
is thus returned to the unlocked and latched condition illustrated in 
FIGS. 2 and 3. 
The latch assembly 10 may be locked electrically, using the motor 162, or 
manually from inside of the vehicle (typically by using a sill button, not 
shown) or from outside of the vehicle using a key. Referring now to FIGS. 
2, 3, 8, 10, and 11, the user operates the control circuit 163 to 
momentarily electrically energize the motor 162. It is anticipated that 
the motor 162 need only be energized a short period, perhaps 0.2 seconds, 
to drive the sector gear 112 in a counterclockwise direction (to the right 
in FIG. 11) to the lock position thereof. It is expected that the motor 
162 will be deenergized shortly before the sector gear 112 reaches the 
lock position, but that momentum will drive the sector gear 112 the 
remaining distance to the lock position thereof. Note that the sector gear 
112 does not strike any of the stop blocks 176 in the lock position 
thereof, but as will be explained below, may be stopped by the control 
member 138 if it attempts to overshoot its locked position. The sector 
gear 112 will then be returned to the centered position thereof by the 
center spring 136, backdriving the motor 162 and associated gear train, as 
shown in FIGS. 12 and 13. 
As the sector gear 112 rotates, the inclined surface 128 of the sector gear 
112 bears against the ramp 150 on the arm 146 and the ramp 156 on the lug 
152 on the arm 146, driving the arm 146 counterclockwise to rotate the 
control member 138 to the lock position thereof. The control member 138 
and components of the latch mechanism 12 coupled for rotation therewith 
move relatively easily. Therefore, not enough resistance is developed 
thereby to cause the arm 146 to ride up the inclined surface 128 against 
the downward force of the spring 160. 
As the control member 138 rotates, the fingers 142 thereof rotate the 
exterior lock member 60 counterclockwise. This causes the free end portion 
78 of the arm 76 to move generally toward the slot 94 in the release 
member 92. The over-center spring 98 is compressed until the exterior lock 
member 60 passes the mid-point of travel, then acts to urge the exterior 
lock member 60 counterclockwise toward the lock position thereof. The link 
member 86, pivotally driven by the free end portion 78 at one end, and 
guided by the pin 90 in the slot 94 in the release member 92 in the other, 
drives the pin 90 out of the notch 43 in the pawl 40. Thus, the release 
member 92 is uncoupled from the pawl 42, and the latch assembly 10 is 
locked. 
Note that the rotation of the exterior lock member 60 is limited by the 
stops 20a and 20b formed on the flange 20 of the base plate 16. Those of 
ordinary skill in the art will recognize that other means may be used to 
limit the rotation of the exterior lock member 60. For example, stops 
could be formed on the central portion 18 of the base plate 16, on either 
side of the arm 68. When the exterior release member 60 rotates 
counterclockwise, it hits the stop 20b, preventing further rotation of the 
exterior release member 60 and thus preventing further rotation of the 
control member 138. The over-center spring 98 holds the exterior release 
member 60 against the stop 20b. If the sector gear 112 attempts to coast 
past the lock position, the sector gear 112 and the deenergized motor 162 
have insufficient momentum to drive the inclined surface 128 of the sector 
gear 112 under the ramp 150 on the arm 146, because of the downward 
pressure of the spring 160 on the control member 138. Thus, the sector 
gear 112 will reverse direction of rotation at the stop position, and 
spring return to the center position thereof, while the control member 138 
and the arm 146 thereof remain in the lock position. 
As indicated above, the latch assembly 10 can also be locked manually from 
inside or outside of the vehicle. Depressing a sill button (or similar 
device) inside the vehicle will actuate the interior lock mechanism (not 
shown). The interior lock mechanism is coupled to the interior lock member 
50 as described above, and will cause the interior lock member 50 to 
rotate counterclockwise. This causes the control member 138 to rotate the 
exterior lock member 60 in the same way that the control member 138 
rotates the exterior lock member 60 during electrical locking of the latch 
assembly 10, as described above. Although the arm 146 of the control 
member 138 rotates to the lock position, the sector gear 112 will remain 
in the center position. Thus, following manual locking of the latch 
assembly 10, the components of the latch assembly 10 will be in the 
positions shown in FIGS. 12 and 13. 
Manually locking the latch assembly 10 from outside the vehicle will 
actuate the exterior lock mechanism, which is directly coupled to the 
exterior lock member 60. The resultant locking operation of the latch 
assembly 10 as the exterior lock member 60 is rotated will be identical to 
that described above for locking from the interior of the vehicle. This is 
because the interior lock member 50 and the exterior lock member 60 are 
coupled for simultaneous rotation by the control member 138. 
Unlocking of the latch assembly 10 can similarly be accomplished 
electrically by actuating the control circuit 163, or manually from inside 
or outside the vehicle. When the operator desires to unlock the latch 
assembly 10 electrically, the input pushbutton signals the control circuit 
163 to energize the motor 162 for rotation in the opposite direction to 
that required for locking. Again, the control signal will energize the 
motor 162 for only a fraction of a second, which is sufficient to drive 
the sector gear 112 from the center position thereof to the unlock 
position thereof. It is anticipated that the motor 162 may be deenergized 
just before the sector gear 112 reaches the unlock position, and inertia 
of the motor 162, and associated gearing, including the sector gear 112, 
carry the sector gear to the unlock position. At the unlock position, the 
sector gear 112 strikes the adjacent stop block 176 and then reverses 
direction under the influence of the center spring 136. The center spring 
136 drives the sector gear 112 back to the center position. 
As the sector gear 112 drives toward the unlock position, the end of the 
channel 122 in the sector gear 112 which is near the stop block 131 
engages the flange 148 on the arm 146 of the control member 138. Thus the 
sector gear 112 rotates the control member 138 and the arm 146 thereon 
clockwise to the unlock position, as shown in FIGS. 14 and 15. When the 
sector gear 112 spring returns to the center position, the control member 
138 and arm 146 thereof remain in the unlock position. The fingers 142 on 
the control member 138 rotate the exterior lock member 60 along with the 
interior lock member 50 clockwise to the unlock position thereof. Thus, 
the exterior lock member 60, acting through the link member 86 moves the 
pin 90 within the slot 94 in the release member 92 and radially inwardly 
into the notch 43 in the pawl 40. The exterior lock member 60 will be held 
in the unlock position thereof by the over-center spring 98. The pawl 40 
and the release member 92 are thus coupled by the pin 90, as shown in FIG. 
2, and the latch assembly 10 is returned to the latched, unlocked state. 
Locking of the latch assembly 10 from inside or outside of the vehicle 
results in identical operation of the interior lock member 50 and the 
exterior lock member 60, since they are coupled by the control member 138. 
In either case, the rotation of the exterior lock member 60 will cause the 
pin 90 to engage the notch 43 in the pawl 40, coupling the pawl 40 to the 
release member 92, unlocking the latch assembly 10. As the interior lock 
member 50 and the exterior lock member 60 rotate with the control member 
138, the arm 146 of the control member 138 moves to the unlock position 
thereof. The sector gear 112 remains in the center position thereof. 
The latch assembly 10 may also be placed a double lock condition, in which 
the latch mechanism 12 is locked, and the interior lock mechanism is 
disabled to prevent unlocking the latch mechanism 12 from inside the 
vehicle. To help ensure that the user does not unintentionally disable the 
interior lock mechanism, typically a separate control action will be 
required to double lock the latch assembly 10 which is distinct from the 
control action required to lock the latch assembly 10. For example, the 
control circuit 163 may be provided with a pushbutton for double-locking 
which is separate from the pushbutton for locking, and wired to require 
both pushbuttons be depressed simultaneously to achieve double locking. 
The operation of the latch assembly 10 during double-locking is initially 
the same as in locking as described above, except that the motor 162 is 
energized for a longer period of time (typically about 0.6 seconds). The 
sector gear 112 moves counterclockwise from the position illustrated in 
FIG. 2 if the latch assembly 10 is initially unlocked, or from the 
position illustrated in FIG. 12 if the latch assembly 10 is initially 
locked. The inclined surface 128 of the sector gear 112 engages the flange 
148 and lug 152 on the arm 146 of the control member 138, rotating the arm 
146 to the lock position thereof, if the arm 146 is not already in the 
lock position. The motor 162 continues to drive the sector gear 112 
counterclockwise toward the double-lock position thereof after the arm 146 
has butted up against the stop 176. This causes the inclined surface 128 
of the sector gear 112 to cooperate with the ramp 150 on the flange 148 
and the ramp 156 on the lug 152 to cause the arm 146 of the control member 
138 upwards. 
The arm 146 is a stiff member, and thus the control member 138 is moved 
upwardly with the arm 146, compressing the spring 160. The motor 162 
should be energized long enough to cause the ridge 129 in the channel 122 
to drive under and then to the right of the flange 14 (as seen in FIGS. 16 
and 17). The spring 160 will cause the control member 138 to drop 
slightly, until the flange 148 on the arm 146 thereof rests on the shallow 
portion 124 of the channel 122. The ridge 129 helps prevent the flange 148 
of the arm 146 from inadvertently slipping off of the shallow portion 124 
and down the inclined surface 128, due to vibration of the vehicle for 
example, thus holding the control member 138 in the raised position. 
As shown in FIG. 18, moving the control member 138 to the raised position 
thereof causes the fingers 142 to disengage from the notches 56 (FIG. 1) 
in the interior lock member 50. The interior lock member 50 is thus no 
longer coupled for rotation with the exterior lock member 60. Thus 
operation of the interior lock mechanism (not shown) by means of a sill 
button and causing the interior lock member 50 to rotate clockwise will be 
ineffective to unlock the latch assembly 10, since the exterior lock 
member 60 will not be rotated thereby. The exterior lock member 60 will 
continue to act through the link member 86 to keep the pin 90 disengaged 
from the notch 43 in the pawl 40, and thus the latch mechanism 12 will 
remain locked regardless of how the interior lock member 50 is moved. The 
latch assembly 10 is in the double lock position in which not only is the 
release member 92 uncoupled from the pawl 40, but the interior lock member 
50 is uncoupled from the latch mechanism 12. 
The latch assembly 10 can be taken out of this double lock position either 
electrically, by energizing the motor 162, or manually, by operation of 
the exterior lock mechanism (not shown). When returning the latch assembly 
10 to unlocked from double lock position manually, typically a key 
cylinder (not shown) in the vehicle door is rotated by the user using a 
key. The key cylinder acts through the exterior lock mechanism to rotate 
the exterior lock member 60 clockwise. The exterior lock member 60 will 
act through the link member 86 to draw the pin 90 into the notch 43, 
unlocking the latch mechanism 12. 
Operation of the interior lock mechanism while in double lock may have 
caused the interior lock member 50 to have rotated relative to the 
exterior lock member 60, causing the respective notches 56 and 66 thereof 
to become vertically misaligned. Therefore, provisions are made for 
realigning the exterior lock member 60 and the interior lock member 50 
when taking the latch assembly 10 out of the double lock position either 
manually or electrically. As the exterior lock member 60 is rotated 
clockwise to the unlock position thereof, the tab 70 on the arm 68 of the 
exterior lock member 60 will bear against the subjacent edge of the arm 54 
of the interior lock member 50 when the arm 68 and the arm 54 are 
vertically aligned. This indexes the arm 68 of the exterior lock member 60 
over the arm 54 of the interior lock member 50. As the exterior lock 
member 60 continues to rotate clockwise to the unlock position, the arm 54 
of the interior lock member 50 will be kept in vertically alignment with 
the arm 68 by the tab 70. With the arms 54 and 68 thus aligned, the pair 
of opposed notches 66 formed in the body 62 of the exterior lock member 60 
are axially aligned with the notches 56 formed in the interior lock member 
50. Thus, when the control member 138 is moved to the lowered position 
thereof, the fingers 142 will engage the notches 56 formed in the interior 
lock member 50. 
As the exterior lock member 60 is rotated clockwise, the control member 
138, and the arm 146 thereof, will also be rotated clockwise by means of 
the fingers 142 thereof, which engage the notches 66 of the exterior lock 
member 60. The sector gear 112 will initially rotate with the arm 146 due 
to the arm 146 engaging the ridge 129 across the shallow portion 124 of 
the channel 122 in the sector gear 112. Therefore the control member 138 
will remain in the raised position thereof. The ramp 156 on the lug 152 
extending from the arm 146 of the control member 138 will therefore be 
driven into the tab 174 as the control member 138 rotates clockwise. 
As the control member 138 is further driven clockwise, the lug 152 will cam 
over the top of the tab 174, lifting the control member 138 higher and 
further compressing the spring 160. With the arm 146 of the control member 
138 thus disengaged from the sector gear 112, the sector gear 112 will be 
moved to the center position thereof under the urging of the center spring 
136. The control member 138 will continue to be driven clockwise by the 
exterior lock member 60, as the control member 138 does not rise enough to 
disengage the fingers 142 of the control member 138 from the exterior lock 
member 60. 
When the lug 152 of the arm 146 is rotated off of clockwise edge of the tab 
174, the spring 160 will urge the control member 138 downwardly. When the 
tab 70 vertically aligns the notches 66 of the exterior lock member 60 
with the notches 56 of the interior lock member 50, as described above, 
the spring 160 will drive fingers 142 of the control member 138 downwardly 
into engagement with the notches 56 of the interior lock member 50. 
When the exterior lock member 60 is moved to the fully clockwise, unlocked 
position thereof, the arm 146 of the control member 138 will similarly be 
moved to the unlocked position thereof, and the sector gear 112 will be in 
the center position thereof, as illustrated in FIGS. 2, 3, and 8. 
When returning the latch assembly 10 to unlocked from double lock position 
electrically, the lug 152 on the arm 46 of the control member 138 will 
initially start to be driven over the top of the tab 174 by the sector 
gear 112. As the arm 146 starts to rise, the ridge 129 will be driven 
under the central surface 154 on the lug 152. Normally, it is anticipated 
that the arm 146 of the control member 138 will slide off of the the tab 
174 to the right. The arm 146 of the control member 138 will slide down 
the inclined surface 128 in the channel 122 in the sector gear 112, until 
the fingers 142 of the control member 138 rest on the flange 46 of the 
lock member pivot 44, and the control member 138 is in the lowered 
position thereof. Note that the control member 138 is being pressed 
downwardly by the spring 160. The arm 146 of the control member 138 will 
be disengaged from the sector gear 112 in this position, and will stop 
until the stop block 131 on the rotating sector gear 112 drives the arm 
146 under the tab 174 to the unlock position, as shown in FIGS. 14 and 15. 
Thus, the arm 146 will return to the lock position shown in FIG. 13, and 
the sector gear 112 will spring return to the center position much like 
when the latch assembly 10 is unlocked from the (single) locked condition. 
However, the lug 152 may not slide off of the tab 174, as described in the 
preceding paragraphs, due to wear of the components or a buildup of 
contaminants on the surface thereof. In this case, the lug 152 on the arm 
146 of the control member 138 will remain hanging by the ramp 156 on the 
tab 174 until the lug 152 is driven over the top of the tab 174 by the 
stop block 131 on the sector gear 112, as shown in FIGS. 19 and 20. When 
the lug 152 is moved off of the clockwise edge of the tab 174, the control 
member 138 will be driven downwardly by the spring 160 to reengage the 
notches 56 in the interior lock member 50 as described above during manual 
operation of the latch assembly 10. The stop block 131 will continue to 
drive the arm 146 of the control member 138 to the unlocked position 
thereof, whereupon the motor will be deenergized and the sector gear 112 
will spring return to the center position. Thus the latch assembly 10 is 
in the unlocked, latch position shown in FIGS. 2, 3, and 8. 
FIGS. 21 through 24 illustrate a second embodiment of a latch assembly 
according to the invention, indicated generally at 200. Those components 
of the latch assembly 200 which have a similar structure and function to 
components of the latch assembly 10 are denoted by the same reference 
numbers, and will not be further described. 
The central portion 18 of the base plate 16 is punched to provide a 
bifurcated surface 204 adjacent the lock member pivot 44. The purpose of 
the bifurcated surface 204 will be explained below. 
The upper end of the lock member pivot 44 is provided with an extension 206 
of reduced diameter compared to the middle portion thereof, thereby 
defining a shoulder 208 between the upper end and middle portions of the 
lock member pivot 44. A wave washer spring 214 is seated on the upper 
surface of the flange 46 of the lock member pivot 44. The spring 214 
resiliently supports an interior lock member 216. The interior lock member 
216 includes a flat annular body 218. Extending radially outwardly from 
opposite sides of the body 218 are a tab 220 and an arm 222. A pair of 
upwardly extending flanges 224 are formed on either side of the arm 222, 
the purpose of which will be explained below. An additional flange 226 
extends upwardly from one side of the arm 222, radially outward of the 
flanges 224. The flange 226 is notched to permit interconnection with the 
interior lock operating mechanism (not shown). The interior lock member 
216 can pivot on the lock member pivot 44. 
Also pivotally mounted on the lock member pivot 44, above the interior lock 
member 216, is an exterior lock member 228. The exterior lock member 228 
has an elongate, generally rectangular body 230. The body 230 has a first 
end 232, a second end 234, and a pivot hole 236 formed therethrough 
approximately one third of the distance from the first end 232 to the 
second end 234. The extension 206 on the upper end of the lock member 
pivot 44 extends through the pivot hole 236, with the exterior lock member 
228 riding on the shoulder 208 on the lock member pivot 44. The upper end 
of the extension 206 is preferably peened over to retain the exterior lock 
member 228 thereon, thereby also capturing the interior lock member 216 
and spring 214 on the lock member pivot 44. 
The first end 232 of the exterior lock member 228 is adapted to fit between 
the flanges 224 of the interior lock member 228, as will be further 
explained below. The second end 232 of the body 230 has an enlarged head 
having an arcuate slot 238 formed therethrough. The slot 238 provides a 
means for connecting the exterior lock member 228 to the exterior lock 
mechanism (not shown). A rectangular aperture 240 is formed in the second 
end 234, between the slot 238 and the pivot hole 236, the purpose of which 
will be described below. 
An arm 242, similar in shape and function to the arm 76 on the exterior 
lock member 60, described above, extends outwardly from the exterior lock 
member 228 between the pivot hole 236 and the second end 234 of the body 
230. The arm 242 is pivotally connected to the link member 86 by the link 
pivot 84. As with the exterior lock member 60, the exterior lock member 
228 can be selectively rotated to cause the link member 86 to move the pin 
90 into and out of alignment with the projection 43 on the pawl 40, 
thereby respectively unlocking and locking the latch assembly 200. 
An alignment flange 244 is formed on the side of the body 230 opposite to 
the arm 242, between the second end 234 and the pivot hole 236. The 
alignment flange 244 extends downwardly, and is adapted to selectively 
engage the tab 220 on the interior lock member 216. For reasons which will 
be discussed below, the alignment flange 244 is longer than either of the 
flanges 224 on the interior lock member 216. 
A plastic detent cam 246 is disposed in the aperture 240 in the second end 
234 of the exterior lock member 228. The cam 246 is made of a resilient 
plastic material. The cam 246 bears on the central portion 18 of the base 
plate 16. As the exterior lock member 228 is pivoted about the lock member 
pivot 44, the cam 246 cooperates with the bifurcated surface 204 to act as 
an over-center spring. The cam 246 will override the bifurcated surface 
204 as the exterior lock member 228 is rotated, with the cam 246 being 
compressed against the arm 264. After the cam 246 has been moved beyond 
the center point of the bifurcated surface 204, the cam 246 resiliently 
expands against the bifurcated surface 204 to urge the exterior lock 
member 228 toward the closer of a lock or an unlock position. 
The housing 100 may be modified to provide recesses 250 therein. 
Magnetically operated switches 252 can be mounted in the recesses 250, and 
electrically connected to the control circuit 163 for a purpose which will 
be explained below. An upwardly extending collar 254 is formed around the 
opening 106 through the housing 100. A notch 256 is formed in the collar 
254, the purpose of which will be described below. 
The latch assembly 200 includes a control member 258. The control member 
258 has a cylindrical body 260. Two spaced apart legs 262 extend 
downwardly from the body 260. An arm 264 extends radially outwardly from 
the upper end of the body 260. One edge of the arm 264 is inclined 
upwardly toward the center of the arm 264 to form an inclined surface 266. 
A recess 268 may be formed on the upper surface of the arm 264 for a 
purpose which will be described below. 
The control member 258 is rotatably mounted in the collar 254, with the arm 
264 captured within the notch 256. Thus the arm 264 cooperates with the 
vertical edges of the notch 256 to limit the rotation of the control 
member 258. As will be further discussed below, when the arm 264 is 
against the counterclockwise vertical edge of the notch 256, the control 
member 258 will be in the lock position thereof. When the arm 264 is 
against the clockwise vertical edge of the notch 256, the control member 
258 will be in the unlock position thereof. 
The body 260 of the control member 258 extends through the opening 106. The 
quad O-ring 110 provides a leak-tight seal between the body 260 of the 
control member 258 and the housing 100. The legs 262 straddle the exterior 
lock member 228 and rest on opposed portions of the body 218 of the 
interior lock member 216. When the spring 214 is uncompressed such that 
the interior lock member 216 is a raised position, the control member 258 
is supported in a raised position with the arm 264 spaced upwardly from 
the bottom edge of the notch 256. 
A magnet 270 may be provided in the recess 268 in the arm 264 of the 
control member 258. As the control member 258 is rotated, the magnet 270 
moves over and interacts with the switches 252 to cause the switches to 
change state, thereby providing a signal to the control circuit 163 
indicating the position of the control member 258. Such a signal may be 
used for control or indication purposes. 
A sector gear 272 is provided with a generally triangular cavity 274 formed 
on the lower side thereof (the sector gear 272 is shown inverted in FIG. 
21). A generally circular portion 276 of the cavity 274 is formed about 
the axis of rotation of the sector gear 272. A raised member 277 is formed 
in a corner of the base portion of the triangular cavity 274. The raised 
member 277 has a lower horizontal surface 278 positioned intermediate the 
horizontal surface of the cavity 274 and the lower surface of the sector 
gear 272. The raised member 277 also includes an inclined surface 280 
extending from the horizontal surface of the cavity 274 to the horizontal 
surface 278. A lip 282 is formed between the horizontal surface 278 of the 
raised member 277, the purpose of which will be discussed below. 
The spring 214 urges the control member 258 upwardly against the sector 
gear 273. The upper surface of the sector gear 273 rides against the cover 
161 of the latch assembly 200. Gear teeth are formed into the lower 
surface of the sector gear 272 adjacent the widest part of the cavity 274 
to form an arcuate gear rack 284. The gear rack 284 meshes with the drive 
gear pinion 168, so that the sector gear 273 can be rotated by the motor 
162. The center spring 136 acts to drive the sector gear to a center 
position in a manner similar to that of the latch assembly 10. 
It will be appreciated that in operation the functioning of the latch 
mechanism 12 of the latch assembly 200 is unchanged from that of the latch 
assembly 10 when the latch assembly 200 is unlocked. 
The latch assembly 200 may be locked electrically by energizing the motor 
162 to drive the sector gear 272 counterclockwise as seen in FIG. 22. The 
raised member 277 on the sector gear 272 drives into the inclined surface 
266 of the arm 264 of the control member 258. The raised member 277 does 
not override the arm 264, but rather urges the arm 264 and the control 
member 258 to rotate counterclockwise to the lock position thereof, as 
seen in FIG. 24. The motor 162 may be deenergized based on the lapse of a 
predetermined time period, or based on actuation of one or more switches 
252 indicating that the motor 162 has moved the arm 264 of the control 
member 258 to the lock position. The legs 262 of the control member 258 
cause the exterior lock member 228 to rotate counterclockwise to the lock 
position thereof. This causes the link member 86 to drive the link pin 90 
out of alignment with the pawl 40, locking the latch assembly 200. The 
flanges 224 on the interior lock member 216 are engaged with the exterior 
lock member 228, and thus the interior lock member 216 is also rotated to 
the lock position thereof. When the motor 162 is deenergized, the center 
spring 136 drives the sector gear 272 back to the center position. 
The latch assembly 200 may be manually locked from the inside or outside of 
the vehicle in a manner similar to that of the latch assembly 10 described 
above. When locking from the exterior of the vehicle, the exterior lock 
member 228 is directly actuated by the exterior lock mechanism to move the 
link member 86 to the lock position thereof. Similarly, the interior lock 
mechanism can be actuated to move the interior lock member 216 to the lock 
position thereof. The flanges 226 on the interior lock member 226 then 
drive the exterior lock member 228, and the link member 86 to the lock 
position thereof. When manually locking the latch assembly 200, the 
control member 258 is rotated. However, the lost motion provided by the 
center spring 136 having moved the sector gear 272 to the center position 
prevents having to back drive the motor 162 through the gear train. 
The latch assembly 200 may be unlocked by energizing the motor 162 to drive 
the sector gear 272 in a clockwise direction (as viewed in FIG. 22). The 
arm 264 of the control member 258 is engaged by the vertical edge of the 
cavity 274 and driven to the unlock position thereof and reversing the 
actions of electrically locking the latch assembly 200 described above. 
Similarly, the latch assembly 200 may be manually unlocked from inside or 
outside the vehicle by operating the lock mechanism associated with the 
interior lock member 216 or the exterior lock member 228, respectively. 
The motor 162 may be electrically operated to place the latch assembly 200 
in a double lock condition. The motor 162 is operated to drive the sector 
gear 272 to counterclockwise as viewed in FIG. 22. Initially, the raised 
member 277 merely drives the arm 264 of the control member 258 toward the 
lock position thereof, as shown in FIG. 24, and as described above. 
However, the motor 162 continues to rotate the sector gear 272 after the 
arm 264 has moved to the lock position and is stopped by the adjacent 
vertical edge of the notch 256. This causes the inclined surface 280 of 
the raised member 277 to cooperate with the inclined surface 266 of the 
arm 264 to urge the control member 258 downwardly to a double lock 
position, as shown in FIG. 25. The legs 262 of the control member 258 urge 
the body 218 of the interior lock member 216 downward, compressing the 
spring 214, until the horizontal surface 278 of the raised member 277 is 
positioned above the arm 264. The motor 162 is then deenergized. 
The lip 282 on the raised member 277 engages the arm 264, holding the 
horizontal surface 278 of the raised member 277 above the arm 264, and 
holding the control member 258 depressed in the double lock position. The 
legs 262 of the control member 258 remain engaged with the exterior lock 
member 228. The cam 246 on the lower side of the exterior lock member 228 
cooperates with the bifurcated surface 204 on the base plate 16 to hold 
the exterior lock member 228 in the lock position. Thus the center spring 
136 is prevented from rotating the sector gear 272 back to the center 
position thereof. 
When the control member 258 is depressed into the double lock position, the 
legs 262 thereof hold the interior lock member 216 down so that the 
flanges 224 on the interior lock member 216 are disengaged from the 
exterior lock member 228. The interior lock mechanism may be operated to 
rotate the interior lock member 216 to the unlock position. However, the 
exterior lock member 228 will remain in the lock position, and the latch 
assembly 200 will remain locked. 
To unlock the latch assembly 200 from the double lock position, the motor 
162 is energized to rotate the sector gear 272 in the clockwise direction. 
The arm 264 remains engaged by the lip 282 on the raised member 277 of the 
sector gear 272, and is urged by the lip 282 to the unlock position 
thereof, where the arm 264 engages the adjacent vertical edge of the notch 
256 in the collar 254. 
As the control member 258 is rotated by the arm 264 thereof, the legs 262 
thereof urge the exterior lock member 228 to rotate to the unlock 
position, causing the latch assembly 200 to unlock in the manner described 
above. As the exterior lock member 228 rotates, the alignment flange 244 
thereof engages the tab 220 on the interior lock member 216. The alignment 
flange 244 urges the interior lock member 216 to rotate with the exterior 
lock member 228 to the unlock position to ensure that the interior lock 
member 216 is vertically aligned with the exterior lock member 228 when 
the exterior lock member 228 is in the unlock position. 
After the arm 264 engages the vertical edge of the notch 256, the sector 
gear 272 continues to rotate, causing the lip 282 of the raised member 277 
to ride over the arm 264 of the control member 258. The sector gear 272 
continues to rotate as the inclined surface 280 passes over the arm 264, 
allowing the spring 214 to urge interior lock member 216 and the control 
member 258 upwardly. As the interior lock member 216 moves upwardly, the 
flanges 224 thereon engage the exterior lock member 228, re-coupling the 
interior lock member 216 and the exterior lock member 228 for simultaneous 
rotation. After the raised member 277 is moved off of the arm 264, the 
motor 162 is deenergized, and the center spring 136 returns the sector 
gear 272 to the center position. 
It is contemplated that the latch assembly 200 may be modified to include a 
plate 170 with tab 174, and the arm 264 of the control member 258 modified 
to include a lug similar to the lug 152 on the control member 138. These 
or other modifications may be made to permit the latch assembly 200 to be 
manually unlocked from the double lock condition in a manner similar to 
that of the first embodiment described above. It is also contemplated that 
the control member 258 may be modified to include multiple arms 264, and 
the sector gear 272 modified to provide a plurality of raised members 277 
to engage the arms 264. This may be done in order to provide a balanced 
force and torque application to the control member 258 in the manner of 
the third embodiment of the invention, described below. 
FIG. 26 illustrates a third embodiment of a latch assembly according to the 
invention, indicated generally at 310. The latch assembly 310 functions in 
a manner similar to the latch assembly 10, and components which have a 
similar structure and function to the components of the latch assembly 10 
are denoted by the same reference numbers. 
An exterior release lever 312 forming a portion of the exterior release 
mechanism is pivotally mounted on a pivot 314 fixed to the base plate 16. 
An arm 312a of the lever 312 is disposed to selectively bear against one 
of the flanges 96 of the release member 92. The exterior release mechanism 
can be actuated to cause the lever 312 to rotate from a normal position to 
a release position, thus driving the release member 92 to the respective 
release position thereof. A spring 316 is provided to urge the lever 312 
toward the normal position thereof. 
The interior release mechanism includes a bellcrank 318. The bellcrank 318 
is pivotally mounted on a pivot 319 fixed to the the flange 20 of the base 
plate 16. The pivot 319 has an enlarged head 319a to retain the bellcrank 
318 on the pivot 319. The bellcrank 318 is operatively coupled to an 
interior release link 320. The interior release link 320 is provided with 
a central slot 320a, and a flange 320b. A pivot 322 extends through the 
central slot 320a and is fixed to the flange 20 of the base plate 16. The 
pivot 322 is provided with an enlarged head 322a for retaining the 
interior release link 320 on the pivot 322. The interior release link 320 
can be pivoted slightly on the pivot 322, and can be moved axially 
relative to the pivot 322. When the bellcrank 318 is rotated clockwise (as 
viewed in FIG. 26) by the interior release mechanism (not shown), the 
flange 320b of the interior release link 320 is driven from an unactuated 
position leftward against the adjacent one of the flanges 96 of the 
release member 92. This causes the release member 92 to rotate clockwise 
to the unlatch position thereof. If the latch assembly 200 is unlocked 
(with the link pin 90 positioned in the radially inner end of the slot 94 
in the release member 92), rotation of the release member 92 to the 
unlatch position will cause the pawl 40 to disengage from the rotor 30. 
A child safety lever 324 may be provided which either blocks actuation of 
the release mechanism, or, preferably, decouples the release mechanism 
from the latch mechanism. 
In an embodiment in which the child safety lever 324 acts to uncouple the 
release mechanism from the latch mechanism, a spring (not shown) is 
disposed about the pivot 322 between the interior release link 320 and the 
flange 20. This spring acts to urge the interior release link 320 away 
from the flange 20. The child safety lever is pivotally mounted on a pivot 
326 fixed to the flange 20 on the base plate 16. The pivot 326 is provided 
with an enlarged head 326a to retain the child safety lever 324 on the 
pivot 326. The child safety lever 324 is pivotal between an uncoupling 
position (clockwise as viewed in FIG. 26) and a neutral position 
(counterclockwise). 
When the child safety lever 324 is in the neutral position, the interior 
release link 320 is free to move to engage a tab 96 on the release member 
92, causing the release member 92 to rotate and unlatch the latch assembly 
310. When the child safety lever 324 is rotated to the uncoupling 
position, an end 324a of the child safety lever having an inclined surface 
is rotated to engage the interior release link 320, urging the interior 
release link 320 toward the flange 20, and compressing the spring 
therebetween. In this position, when the interior release link 320 is 
actuated, the flange 320b thereon will not engage the tab 96 on the 
release member 92. Thus, when the child safety lever 324 is in the 
uncoupling position thereof, the latch assembly 310 is not able to be 
opened from within the vehicle. 
The child safety lever 324 may also be designed to block movement of the 
interior release link 320 to prevent operation of the release member 92. A 
washer (not shown) or other means is provided to fix the plane of movement 
of the interior release link 320 in alignment with the tab 96 on the 
release member 92. The child safety lever 324 is pivotally mounted on the 
pivot 326 fixed to the flange 20 on the base plate 16. The pivot 326 is 
provided with an enlarged head 326a to retain the child safety lever 324 
on the pivot 326. The child safety lever 324 is pivotal between a 
non-blocking position and a blocking position. In the blocking position, 
the end 324a of the child safety lever is aligned with and adjacent to the 
flange 320b on the interior release link 320 to prevent the interior 
release link 320 from moving to the actuated position thereof. Thus, when 
the child safety lever 324 is in the blocking position thereof, the 
interior release link 320 is not able to engage the tab 96 to drive the 
release member 92 to the release position, and the latch assembly 310 is 
not able to be opened from within the vehicle. The child safety lever 324 
may also be placed in the non-blocking position thereof, in which the end 
324a is out of alignment with the flange 320b on the interior release link 
320. As a result, the interior release link 320 is free to move axially 
from the unactuated position thereof to the actuated position thereof, and 
cause the release member 92 to rotate. 
The exterior and interior lock mechanisms are also illustrated in FIG. 26. 
An interior sill button 328 is operatively connected through a linkage 329 
(shown schematically) to an interior lock bellcrank 330. The bellcrank 330 
is pivotally mounted on a pivot pin 331 fixed to the flange 20 of the base 
plate 16. The pivot pin 331 is provided with an enlarged head 331a to 
retain the bellcrank 330 thereon. The bellcrank 330 is connected to the 
interior lock member 50 by an interior lock link 332, which engages the 
aperture 58 in the arm 54 of the interior lock member 50. Pulling up on 
the interior sill button 328 causes the linkage 329 to rotate the 
bellcrank 330 clockwise, rotating the interior lock member 50 clockwise to 
the unlock position thereof. Through the same mechanism, pushing down on 
the sill button 328 locks the latch assembly 310. 
The exterior lock mechanism includes a key cylinder 334 which is 
operatively connected to a cam-lock link 336. The cam-lock link 336 is 
pivotally connected to the exterior lock member 60 by means of the 
aperture 74 formed in the arm 68 of the exterior lock member 60. Operation 
of the key cylinder 334 to an unlock position causes the cam-lock link 336 
to rotate the exterior lock member 60 clockwise to the unlock position 
thereof. Similarly, operation of the key cylinder 334 to a lock position 
causes the exterior lock member 60 to rotate counterclockwise to the lock 
position thereof. 
The spur 83 of the exterior lock member 60 may be formed without an 
aperture 83a therethrough. Instead, the spur 83 may be formed with a 
bifurcated lower surface (not shown) which cooperates with a lock lever 
detent 338 to more positively retain the exterior lock member 60 in a 
selected position. The lock lever detent 338 has a resilient arm 338a 
extending horizontally from a body portion 338b. The resilient arm 338a is 
provided with a bifurcated upper surface. The resilient arm 338a will bend 
downwardly when the exterior lock member 60 is operated to permit the spur 
83 to pass thereover. During operation of the latch assembly 310, the 
detent 338 offers only slight resistance to movement of the exterior lock 
member 60, and the detent 338 will be overridden. However, the bifurcated 
upper surface of the resilient arm 338 of the lock lever detent 338 
cooperates with the bifurcated lower surface of the spur 83a to urge the 
exterior lock member 60 toward the closer of the lock and unlock positions 
thereof. Thus, the resilient arm 338a is an over-center spring. The detent 
338 prevents inadvertent movement of the exterior lock member 60, due to 
vehicle vibration for example. The detent 338 is preferably formed of a 
wear-resistant polymeric material, and is preferably fixed to the base 
plate 16. 
A tension spring 340 is coupled between the release member 92 and a point 
fixed relative to the base plate 16, such as the body 338b of the detent 
338. The spring 340 urges the release member 92 to rotate counterclockwise 
toward the normal (unactuated) position thereof. The release member 92 is 
prevented from counterclockwise rotation past the normal position by the 
interior release link 320 and the exterior release lever 312, which engage 
respective flanges 96 on the release member 92. When the release member is 
in the normal position thereof and the pawl 40 is in the engaged position 
thereof, the slot 94 in the release member 92 is vertically aligned with 
the notch 43 of the pawl 40 and the link pin 90 can be moved into the 
notch 43 to unlock the latch assembly 310. Thus the spring 340 facilitates 
unlocking of the latch assembly 310 by urging the release member 92 fully 
into the normal position thereof. 
The actuator 341 of the latch assembly 310 includes a housing 342 of a 
molded plastic material. A plate portion 344 of the housing 342 has an 
opening 346 formed therethrough. A collar 348, similar to the collar 108 
in the first embodiment described above, is formed about the opening 346. 
An upstanding frame 350 is integrally formed with the plate portion 344 of 
the housing 342. An aperture 350a is formed in the frame 350, the purpose 
of which will be described below. The frame 350 is formed with various 
pockets and journals for mounting components therein. The electric motor 
162 is mounted within the frame 350, as are the motor pinion 164, an idler 
gear 352, a clutch gear 354, a clutch 356, and a worm gear 358. The idler 
gear 352 and clutch gear 354 are preferably formed of a polymeric material 
such as nylon, while the worm gear 358 is preferably machined from steel, 
and the motor pinion 164 is formed of a powdered metal. A terminal block 
360 is mounted on the exterior portion of the frame 350 to facilitate 
connecting an electrical power supply to the motor 162. The frame 350 
encloses the components therein, except that the right side (as seen in 
FIG. 26) is closed by a permanently installed cover 362. 
The motor pinion 164, as described above, is fixed to the output shaft of 
the motor 162. The motor pinion 164 meshes with the idler gear 352, which 
in turn meshes with and drives the clutch gear 354. The clutch gear 354 
drives the input of the clutch 356. The clutch 356 is a conventional 
clutch of the type which couples the input and output thereof when the 
input revolves rapidly, but uncouples the input and output thereof when 
the input is at rest, even if the output is revolved rapidly in either 
direction. Thus the clutch 356 will be engaged when the motor 162 is 
energized, but disengage when the motor 162 is deenergized. The output of 
the clutch 356 is coupled to the worm gear 358. 
The threads of worm gear 358 extend partially through the aperture 350a in 
the frame 350 to mesh with the teeth 364a of a sector gear 364. The sector 
gear 364 is pivotally mounted on the collar 348. The lead angle of the 
teeth 364a of the sector gear 364 should be such that the sector gear 364 
is not self-locking. In other words, when the sector gear 364 is rotated 
by manual means, as will be described below, the sector gear 364 should be 
able to back-drive the worm gear 358 with little resistance. The clutch 
356 disconnects the rest of the gear train from the worm gear 358 when the 
sector gear 364 is back driven, thereby minimizing the resistance 
experienced when manually operating the lock mechanism of the latch 
assembly 310. 
The sector gear 364 includes a central bore 364b which is co-axial with the 
opening 346 in the plate portion 344 of the housing 342. The sector gear 
364 is further provided with an upper surface 366. Three cam features 368 
are formed on the upper surface 366. The cam features 368 are equally 
spaced apart about the periphery of the sector gear 364, and spaced 
outwardly from the central bore 364b through the sector gear 364. Each cam 
feature 368 includes a flat portion 368a and, in a counterclockwise 
direction from each flat portion 368a, an associated ramp portion 368b 
inclined downwardly to the upper surface 366 of the sector gear 364. 
Preferably, the sector gear 364 is integrally molded of a 
self-lubricating, wear resistant polymeric material. 
As with the sector gear 112 in the first embodiment described above, the 
sector gear 364 may be selectively moved between a center position and 
unlock, lock, and double lock positions. A modular switch board 370 
includes conventional button switches actuated by a feature (not shown) on 
the sector gear 364 to indicate when the sector gear 364 is in the lock, 
unlock or double-lock positions thereof. The modular switch board 370 
provides logical input to the control circuit 163 (FIG. 2) controlling the 
remote operation of the latch assembly 310. For example, electronic logic 
may be provided in the control circuit 163 to prevent placing the latch 
assembly 310 in double lock and disabling the interior lock mechanism 
while the vehicle ignition circuit is energized. An energized vehicle 
ignition circuit is an indication that authorized occupants are still in 
the vehicle. 
A control member 372 is provided with a cylindrical body 374 having an 
enlarged head 376. The body 374 of the control member 372 is disposed 
within the central bore 364b of the sector gear 364, and extends 
downwardly through the opening 346 in the housing 342. Two fingers 378 
extend downwardly from the lower end of the body 374 to engage the notches 
66 in the exterior lock member 60, and to selectively engage the notches 
56 in the interior lock member 50. Three equally-spaced arms, 380, 382 and 
384, extend radially outwardly from the head 376. The arm 384 is provided 
with a radially outwardly extending lug 386, which is similar in function 
to the lug 152 on the arm 146 of the first embodiment described above. 
In a lowered position of the control member 372, the head 376 thereof bears 
against the upper surface 366 of the sector gear 364, and the arms 380, 
282, and 284 extend outwardly between the cam features 368. The fingers 
378 engage the interior lock member 50. In a raised position of the 
control member 372, the arms 380, 382, and 384 are positioned on top of 
the flat portions 368 of the respective cam features 368, the head 376 is 
raised off of the upper surface 366 of the sector gear 364, and the 
fingers 378 are disengaged from the interior lock member 50. Thus, when 
the control member 372 is in the raised position thereof, the latch 
assembly 310 is in a double lock position. 
A lift ring 388 includes an arcuate body 390 mounted on the plate portion 
344 of the housing 342, adjacent to the sector gear 364. A horizontally 
extending tab 392 is fixed to the body 390, and functions in a manner 
identical to that of the tab 174 of the latch assembly 10 described in the 
first embodiment above. An arm 394 extends from the body 390 over the 
control member 372. The arm 394 is provided with a downwardly extending 
boss 394a which retains and centers the spring 160 between the arm 394 and 
the control member 372. The spring 160 is compressed between the arm 394 
and the control member 372. The arm 394 is provided with an upwardly 
extending tab 396. The center spring 136 is coupled between the tab 396 on 
the lift ring 388 and a feature (not shown) on the sector gear 364 to urge 
the sector gear 364 toward a center position. 
An anti-theft shield 398 is mounted on the housing 344 adjacent to the 
frame 350. The cover 161 is fitted over the lift ring 388 and sector gear 
364. The cover 161, the anti-theft shield 398, and the cover 362 cooperate 
to block access to the internal components of the actuator 341 when the 
door in which the latch assembly 310 is shut and the latch assembly 310 is 
locked. 
The operation of the latch assembly 310 is essentially the same as the 
operation of the latch assembly 10 of the first embodiment described 
above. However, it should be noted that when the sector gear 364 drives 
the control member 372 toward the lock or unlock position thereof, each of 
the arms 380, 382, and 384 are engaged by a respective one of the cam 
features 368. Thus, balanced torque is applied evenly about the control 
member 372, and the control member 372 does not tend to tilt out of 
alignment with the axis of rotation of the sector gear 364, as might 
happen with only one arm on the control member 372 and heavy operating 
loads. Additionally, as the sector gear 364 is driven to the double lock 
position thereof, each of the arms 380, 382, and 384, engage a respective 
ramp portion of the cam features 368 to evenly lift the control member 372 
to the raised position thereof. The control member 372 is lifted without 
tilting which could create large amounts of friction as the body 374 cants 
and engages the periphery of the opening 346 through the housing 342. 
Finally, while the center spring 136 returns the sector gear 364 to the 
center position thereof, the center spring 136 need only overcome the 
resistance of back-driving the worm gear 358, because the clutch 356 will 
uncouple the remaining gears and motor 162 from the worm gear 358. 
In accordance with the provisions of the patent statutes, the principle and 
mode of operation of the present invention have been explained and 
illustrated in its preferred embodiment. However, it must be understood 
that the present invention may be practiced otherwise than as specifically 
explained and illustrated without departing from its spirit or scope.