HOOD LATCH FOR AN ENGINE COMPARTMENT

DISPOSITIF DE VERROUILLAGE DE CAPOT POUR COMPARTIMENT MOTEUR

English Abstract

A hood latch assembly (10) has a housing (14) having a mouth
(13). A ratchet (16) is pivotally mounted within the housing (14) to
cooperate with the mouth (13) to pivot between an open, a secondary
closed and a primary closed condition for receiving, engaging and
cinching a keeper of a striker (80). The ratchet (16) is biased to the
open condition. A pivotally mounted primary pawl (18) is biased for
engagement with the ratchet (16) to releasably retain the ratchet (16) in
the primary closed condition. A pivotally mounted secondary pawl (62)
is biased for engagement with the ratchet (16) to releasably retain the
ratchet (16) in the secondary closed condition. The secondary pawl (62)
has a release lever (20) which rotates between a deployed position and
a retracted position. As the ratchet (16) engages the striker (80), the
ratchet (16) will rotate in a latching sense from the open condition to
the secondary closed condition. As the ratchet (16) further rotates from
the secondary closed to the primary closed condition, fully engaging the
striker (80), the secondary pawl (62) follows the ratchet (16), allowing
the release lever (20) to rotate from a deployed position to a retracted
position. Upon release of the primary engagement by disengaging the
primary pawl (18), the ratchet (16) will rotate from the primary closed to
he secondary closed condition. The secondary pawl (62) will follow the
ratchet (16) rotating the release lever (20) from the retracted position to
the deployed position. The operator then manipulates the release lever
(20) to release the ratchet (16), allowing the ratchet (16) to rotate from
the secondary closed to the open condition. The hood latch (10) has
a light (82) which is operable responsive to movement of the release
arm (20) moving from the retracted position and the deployed position.
Changes of the hood latch (10) between the primary closed condition
and the secondary closed condition will open and close the switch (78).
The switch (78) is disposed between a light source (82) mounted to
illuminate the hood latch (10) region and a source of electrical power.
Opening and closing of the switch (78) will responsively illuminate
the light (82).

French Abstract

Ensemble (10) de verrouillage de capot possédant un boîtier (14) pourvu d'une ouverture (13). Un rochet (16) est monté pivotant à l'intérieur du boîtier (14) afin de coopérer avec l'ouverture (13), de manière à pivoter entre une position ouverte, une deuxième position fermée et une première position fermée dans le but de recevoir une gâche (80), de s'y accoupler et de s'y fixer. Le rochet (16) est sollicité vers la position ouverte. Un premier cliquet (18) monté pivotant est sollicité afin de s'accoupler au rochet (16), de manière à retenir ce dernier de façon amovible dans la première position fermée. Un deuxième cliquet (62) monté pivotant est sollicité afin de s'accoupler au rochet (16), de manière à retenir ce dernier de façon amovible dans la deuxième position fermée. Ce deuxième cliquet (62) possède un levier (20) de déclenchement effectuant une rotation entre une position déployée et une position retirée. Simultanément à son accouplement à la gâche (80), le rochet (16) tournera dans un sens de verrouillage depuis la position ouverte jusqu'à la deuxième position fermée. Simultanément à la continuation de la rotation du rocher (16) depuis la deuxième position fermée jusqu'à la première position fermée, en s'accouplant totalement à la gâche (80), le deuxième cliquet (62) suit le rochet (16), ce qui permet au levier de déclenchement (20) d'effectuer une rotation depuis une position déployée jusqu'à une position retirée. Lorsqu'on supprime le premier accouplement en libérant le premier cliquet (18), le rochet (16) tournera depuis la première position fermée vers la deuxième position fermée. Le deuxième cliquet (62) suivra le rochet (16) en faisant tourner le levier de déclenchement (20) depuis la position retirée vers la position déployée. L'utilisateur manipule ensuite le levier de déclenchement (20) (20) afin de libérer le rochet (16), ce qui permet au rochet (16) de tourner depuis la deuxième position fermée vers la position ouverte. Le verrou (10) de capot possède un éclairage (82) dont le fonctionnement réagit au déplacement du bras de déclenchement (20) depuis la position retirée vers la position déployée. Des modifications de l'ouverture du verrou (10) de capot entre la première position fermée et la deuxième position fermée ouvriront et fermeront le commutateur (78). Ce commutateur (78) est situé entre une source de lumière (82) montée de façon à éclairer le verrou (10) de capot et une source de courant électrique. L'ouverture et la fermeture du commutateur (78) mettra en service l'éclairage (82).

Claims

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We claim:
1. A hood latch comprising:
a housing having a mouth,
a ratchet pivotally mounted within the housing to cooperate with the mouth to
pivot
between an open condition, a primary closed condition and a secondary closed
condition for
receiving, engaging and cinching a keeper of a striker, the ratchet biased to
the open
condition,
a pivotally mounted primary pawl having biasing means for biasing the primary
pawl into engagement with the ratchet for releasably retaining the ratchet in
the primary
closed condition,
a pivotally mounted secondary pawl having biasing means for biasing the
secondary
pawl into engagement with the ratchet for releasably retaining the ratchet in
the secondary
closed condition, said secondary pawl having a secondary release arm extending
therefrom
and said secondary release arm is rotatable between a retracted position when
the primary
pawl is engaged and a deployed position once the primary pawl has been
released.
2. A hood latch as claimed in claim 1 wherein said hood latch further
comprises a light
means mounted for illuminating a region forward of the hood latch, said light
means turning
off and on responsively to the ratchet rotating between the primary closed
condition and the
secondary closed condition.
3. A hood latch as claimed in claim 2 wherein said ratchet has a cam surface
having a
varying radial length and said secondary pawl follows said cam surface
effecting said
movement between the retracted position and the deployed position.
4. A hood latch as claimed in claim 3 wherein said rotatable movement of said
secondary release arm between the retracted position and the deployed is
responsive to
rotation of said ratchet between the primary closed condition and the
secondary closed
condition.
5. A hood latch as claimed in claim 4 wherein when said secondary release arm
is in
the retracted position, said secondary release is in a plane generally
parallel to said housing


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and when said secondary release arm is in the deployed position, said
secondary release arm
extends forwardly of the housing.
6. A hood latch as claimed in claim 5 wherein said light means is mounted at a
distal
end region of the secondary release arm.
7. A hood latch as claimed in claim 6 wherein said light means comprises a
light bulb,
means for electrically connecting the light bulb to an electricity source and
a switch for
opening and closing the electrical connection.
8. A hood latch as claimed in clam 7 wherein said switch is mounted for
engagement
with the primary release pawl.
9. A hood latch as claimed in claim 4 wherein when said secondary release arm
is in
the retracted position, said secondary release is in a plane generally
parallel to said housing
and when said secondary release arm is in the deployed position, said
secondary release arm
is rotated at least 15° thereto.
10. A hood latch as claimed in claim 1 wherein said ratchet has a cam surface
having a
varying radial length and said secondary pawl follows said cam surface
effecting said
movement between the retracted position and the deployed position.
11. A hood latch as claimed in claim 10 wherein said rotatable movement of
said
secondary release arm between the retracted position and the deployed is
responsive to
rotation of said ratchet between the primary closed condition and the
secondary closed
condition.
12. A hood latch as claimed in claim 11 wherein when said secondary release
arm is in
the retracted position, said secondary release is in a plane generally
parallel to said housing
and when said secondary release arm is in the deployed position, said
secondary release arm
extends forwardly of the housing.


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13. A hood latch as claimed in claim 11 wherein when said secondary release
arm is in
the retracted position, said secondary release is in a plane generally
parallel to said housing
and when said secondary release arm is in the deployed position, said
secondary release arm
is rotated at least 15° thereto.
14. A hood latch as claimed in claim 1 wherein when said ratchet has an arm
for
engaging a striker as the ratchet is rotated in a latching sense, and a
hooking arm for
engaging a striker when the ratchet is in a secondary closed condition.
15. A hood latch as claimed in claim 14 wherein said ratchet has a cam surface
having a
varying radial length and said secondary pawl follows said cam surface
effecting said
movement between the retracted position and the deployed position.
16. A hood latch as claimed in claim 15 wherein said rotatable movement of
said
secondary release arm between the retracted position and the deployed is
responsive to
rotation of said ratchet between the primary closed condition and the
secondary closed
condition.
17. A hood latch as claimed in claim 16 wherein when said secondary release
arm is in
the retracted position, said secondary release is in a plane generally
parallel to said housing
and when said secondary release arm is in the deployed position, said
secondary release arm
extends forwardly of the housing.
18. A hood latch as claimed in claim 17 wherein said hood latch further
comprises a
light means mounted for illuminating a region forward of the hood latch, said
light means
turning off and on responsively to the ratchet rotating between the primary
closed condition
and the secondary closed condition.
19. A hood latch as claimed in claim 16 wherein when said secondary release
arm is in
the retracted position, said secondary release is in a plane generally
parallel to said housing
and when said secondary release arm is in the deployed position, said
secondary release arm
is rotated at least 15° thereto.


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20. A hood latch as claimed in claim 19 wherein said hood latch further
comprises a
light means mounted for illuminating a region forward of the hood latch, said
light means
turning off and on responsively to the ratchet rotating between the primary
closed condition
and the secondary closed condition.

Description

CA 02274069 1999-06-03
WO 98/26144 PCT/CA97100941
HOOD LATCH FOR AN ENGINE COMPARTMENT
Field of Invention
This invention relates to a hood latch for a vehicle. In particular, this
invention
relates to a hood latch having a retracting secondary release arm and a light
operable on
release of a primary release.
Background of Invention
Vehicle hood latch systems are well known in the art. Typically, a vehicle
hood or
trunk deck will have a latch for engaging and cinching onto a striker. The
latch will have a
rotatably mounted ratchet engaging a pawl in a ratchet relation. The ratchet
cooperates with
a mouth of the housing to pivot between an open and closed condition for
receiving,
engaging and cinching a keeper of a striker. The pawl retains the ratchet in
the closed and
cinched conditions.
Hood latches are required to have a secondary latching mechanism and a primary
latching mechanism. The primary latching mechanism is operably from inside the
vehicle,
normally under the dashboard. A secondary latching is only operable from the
outside.
It is known to provide a release lever on the secondary latching mechanism
which is
presented only upon the release of the primary latch. Examples of such latch
mechanism are
described in United States patent nos. 4,961601; 4,991,884; 5,000,493 and
5,141,265. In
these latch mechanisms, the secondary latching mechanism is separate from the
primary
latching mechanism, requiring additional components and labor for assembly.
In many cases, the location of the arm is difficult to find requiring the
operator to
probe blindly or bend over to look for the arm. Since the exact location of
the handle varies
from manufacturer to manufacturer, there exists a need to provide a secondary
release lever
which is readily accessible and visible to the operator when the hood latch is
in the
secondary position.
Summary of the Invention
The disadvantages of the prior art may be overcome by providing a hood latch
assembly for a vehicle having a simple mechanism for self presenting a
secondary release
arm upon releasing of the primary release and which retracts upon closure of
the hood.


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It is desirable to provide a hood latch having a light which will illuminate
once the
secondary release arrn is positioned for activation.
According to one aspect of the invention, there is provided a hood latch
assembly
having a housing having a mouth. A ratchet is pivotally mounted within the
housing to
cooperate with the mouth to pivot between an open, a secondary closed and a
primary
closed condition for receiving, engaging and cinching a keeper of a striker.
The ratchet is
biased to the open condition. A pivotally mounted primary pawl is biased for
engagement
with the ratchet to releasably retain the ratchet in the primary closed
condition. A pivotally
mounted secondary pawl is biased for engagement with the ratchet to releasably
retain the
ratchet in the secondary closed condition. The secondary pawl has a release
lever which
rotates between a deployed position and a retracted position. As the ratchet
engages the
striker, the ratchet will rotate in a latching sense from the open condition
to the secondary
closed condition. As the ratchet further rotates from the secondary closed to
the primary
closed condition, fully engaging the striker, the secondary pawl follows the
ratchet, allowing
the release lever to rotate from a deployed position to a retracted position.
Upon release of the primary engagement by disengaging the primary pawl, the
ratchet will rotate from the primary closed to the secondary closed condition.
The
secondary pawl will follow the ratchet rotating the release lever from the
retracted position
to the deployed position. The operator then manipulates the release lever to
release the
ratchet, allowing the ratchet to rotate from the secondary closed to the open
condition.
The hood latch has a light which is operably responsive to a ratchet
engagement of
the primary pawl or alternatively, to the movement of the release arm moving
from the
retracted position and the deployed position. As the hood latch changes states
between the
primary closed condition and the secondary closed condition, the switch will
open and
close. The switch is disposed between a light means mounted to illuminate the
hood latch
region and a source of electrical power. Opening and closing of the switch
will responsively
illuminate the light bulb.
Description of the Drawings
In drawings which illustrate embodiments of the invention,
Figure 1 is an exploded perspective view of the hood latch assembly of the
present invention;


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Figure 2 is an elevational view of the hood latch assembly of Figure I in an
open condition;
Figure 3 is an elevational view of the hood latch assembly of Figure 1 in a
secondary closed condition; and
Figure 4 is an elevational view of the hood latch assembly of Figure 1 in an
primary closed condition.
Description of the Invention
The hood latch assembly 10 of the present invention is generally illustrated
in Figure
I . The latch 10 generally comprises a cover plate 12, a housing 14, a ratchet
or detent fork
16, a primary pawl 18 and a secondary release lever 20.
Cover plate 12 and housing 14 are preferable stamped from sheet metal and each
is
shaped and has a series of holes and bosses for receiving the various
components as will be
described below. Cover plate 12 and housing 14 each has a mouth 11 and 13
respectively.
Detent fork or ratchet 16 is pivotally mounted on pin 22 through aperture 24.
Pin 22
extends between aperture 26 on cover plate 12 and aperture 28 on housing 14.
Ends of the
pin 22 are finished to rivet the cover plate 12 to the housing 14. Spring 30
is concentrically
mounted on pin 22. One end of spring 30 engages arrn 32 of ratchet, while the
other extend
through aperture 34 of housing 14, to bias ratchet 16 to the open condition.
Ratchet 16 has a primary detent 36, a secondary detent 38 and a cam surface
40. The
cam surface 40 has a circumferential extent having a varying radial length. As
the cam
surface 40 rotates relative to the secondary release lever 20 in a latching
sense, the radial
length decreases. Ratchet 16 has a hooking arm 42 which has a distal end which
extends
substantially tangential to the rotation of ratchet I 6. The hook shape of the
distal end
facilitates gripping of the striker when the hood latch is in a secondary
closed condition.
The ratchet I6 cooperates with the mouths I 1 and 13 to releasably retain a
striker mounted
on a hood of a vehicle.
Primary pawl 18 is pivotally mounted on pin 44. Pin 44 extends between
aperture 46
on cover plate 12 and aperture 48 on housing 14. Ends of the pin 44 are
finished to rivet the
cover plate 12 to the housing 14. Spring 50 is concentrically mounted on pin
44-. One end
of spring 50 engages primary pawl 18, while the other extend through aperture
52 of
housing 14, to bias primary pawl 18 into ratchet engagement with ratchet 16.


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Primary pawl 18 comprises a disc 54 which has an abutment 56 for engaging
detent
36 of ratchet 16. Disc 54 also has a switch cam surface 58. Primary pawl 18
has a handle
59 extending from the disc 54. At the distal end of handle 59 is a bowden wire
fixture 60
for receiving a bowden wire for activating the primary pawl 18 from inside the
vehicle.
Secondary release lever 20 has a secondary pawl 62 which receives pin 64 to
pivotally mount secondary release lever 20 onto tab 66 of housing 14. Spring
68 is
concentrically mounted on pin 64. One end of spring 68 engages secondary
release lever 20,
while the other extend through aperture 70 of housing 14, to bias secondary
release lever 20
into engagement with ratchet 16.
Secondary pawl 62 has a tab 72 which follows cam surface 40 of ratchet 16
while
the latch assembly 10 moves between the primary closed or the secondary closed
conditions.
Since the radial length of the cam surface 40 varies, the secondary pawl 62
will rotate as the
ratchet 16 rotates. Preferably, the change in radial length of cam surface 40
will cause at
least 15 ° of rotation of the secondary release lever 20. The length of
the secondary release
lever 20 can be selected to provide a desired amount of movement at the distal
end thereof.
When the latch assembly 10 is in the secondary closed condition, abutment 38
of
ratchet 16 will engage tab 72, resisting rotation of the ratchet 16 in an
opening or unlatching
sense.
Compression spring 74 has a plug 76 fitted in an upper end thereof. Cover
plate 12
and housing 14 each has an arcuate channel for receiving and cradling
compression spring
74 in a manner well known in the art. Plug 76 engages arm 32 of ratchet I6
such that spring
74 provides a hood opening bias.
Switch 78 is mounted onto cover plate 12. Switch arm 79 is positioned to
engage
switch cam surface 58 of primary pawl 18. Switch 78 is electrically connected
to a light 82
mounted at a distal end of the secondary release arm 20. Light 82 is
preferably mounted at
the distal end of secondary release arm 20; however it is readily understood
by those skilled
in the art that the light 82 may be mounted anywhere on or near the latch
assembly 10 to
provide illumination to the general region of the secondary release arm 20.
Light 82 is
preferably an incandescent light bulb, however, other light sources may also
be used. Such
light sources include LED's and fibre optics.
When the latch assembly 10 is in the primary closed condition, switch arm 79
will
extend beyond the end of the switch cam surface, opening the switch 78. When
the latch


CA 02274069 1999-06-03
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_5_
assembly 10 is not in the primary closed condition, switch arm 79 will follow
the switch
cam surface 58, closing the switch 78.
Referring to Figures 2 to 4, the striker 80 will engage arm 32 of ratchet 16
and will
slide therealong as the ratchet 16 rotates in a latching sense from the open
condition to the
secondary closed condition. The abutment 38 will rotate beyond secondary pawl
62 to
allow tab 72 to releasably retain the ratchet 16 in the secondary closed
condition. In this
secondary closed condition, the secondary release lever 20 will be in a
deployed position,
extending generally forwardly of the latch assembly 10.
Further downward movement of the striker 80 will cause the ratchet 16 to
further
rotate in a latching sense. Arm 32 will engage plug 76 to compress spring 74.
Tab 72 will
follow cam surface 40 of ratchet 16, rotating the secondary release lever 20
from the
deployed position to the retracted position, wherein the secondary release
lever 20 will
extend generally in the same plane as the latch assembly 10. Primary pawl 18
will also
follow ratchet 16 until abutment 56 engages detent 36, releasably locking the
ratchet 16 in
the primary closed condition.
Upon release of the primary pawl I 8, abutment 56 will disengage ratchet 16.
The
biasing force of compression spring 74 will rotate the ratchet 16 in a
releasing sense until
abutment 38 engages tab 72 of secondary pawl 62. Secondary pawl 62 has
followed cam
surface 40 causing the secondary release lever 20 to rotate from the retracted
position to the
deployed position. The hooking arm 42 of ratchet I6 will hook onto the striker
80.
Upon release of the secondary release lever 20, secondary pawl 62 will
disengage the
ratchet 16, allowing the bias of spring 30 to rotate the ratchet 16 to the
fully open condition,
releasing the striker 80.
The preceding specific embodiment is illustrative of the practice of the
present
invention. It is to be understood, however, that other expedients known or
apparent to those
skilled in the art or disclosed herein may be employed without departing from
the spirit of
the invention.

Representative Drawing