The present invention relates to automotive door latches, such as may be used in such things as lift gates, deck lids, or sliding doors.
Latch designs need to accommodate different packaging requirements for lift gates, decklids and sliding doors. In addition, automotive companies are looking to provide new features for their vehicles, even on components such as latches. Features such as power locking, power releasing and power cinching are rapidly becoming popular. Other manufacturers desire simpler and less expensive locks. The need for multiple latch packages and feature sets results in the need for multiple latch designs while manufacturers are looking to standardize parts in order to reduce assembly costs. Therefore, it may be desirable to produce a modular latch that can accommodate different features within one assembly.
Additionally, in a vehicle collision, there is the potential that sudden deceleration may generate an inertial load on either the ratchet or pawl to accidentally release the latch. This may not be desirable.
For latches with power cinching, the controller needs to know the position of the ratchet (released, primary engaged, secondary engaged position), in order to know when to begin and when to stop the cinching motor. Typically, switches triggered by either the ratchet or the pawl, or both, tend to report on the ratchet position.
A second prior art switch strategy, shown in
Finally, it is generally desirable to reduce the cost of producing the latch. This includes reducing the product design and development costs, design validation and production validation test costs by using previously designed and validated components. This may reduce the number of components used during assembly, the time required to assemble the latch, and the cost of the components generally.
In an aspect of the invention there is a modular latch for an automotive vehicle. It has a latch core. The latch core has a housing and a ratchet and pawl rotatably mounted to the housing. The ratchet and pawl are cooperatively operable to move between an engaged position to hold a striker and a released position. The latch core is operable to be secured to one of a plurality of mounting plates to secure and present the latch core to the striker. The plurality of mounting plates may include (a) a mounting plate for a lift gate latch, (b) a mounting plate for a decklid latch, and (c) a mounting plate for a sliding door latch. The latch core is further operable to mount any one of a plurality of latch modules, including a manual release latch module, a power release latch module, a power lock and unlock latch module, and a power cinching and release latch module.
In another aspect of the invention there is a latch for an automotive vehicle. It has a latch core. The latch core has a housing and a ratchet and pawl rotatably mounted to the housing. The ratchet and pawl are co-operable to move between an engaged position to hold a striker and a released position. The latch core has securement fittings attachable to any one of a plurality of mounting plates of a set of mounting plates for securing the latch core to a vehicle in a position to present the latch core to the striker. The set of mounting plates includes: a mounting plate for a lift gate latch, a mounting plate for a decklid latch, and a mounting plate for a sliding door latch. The latch core has operational connections attachable to at least one other latch module of a set of other latch modules. That set includes: a manual release latch module, a power release latch module, a power lock and unlock latch module, and a power cinching and release latch module.
In a feature of that aspect of the invention, the core latch further includes a cover plate mounted to the housing, and a channel for receiving a striker defined in each of the mounting plate, the housing and the cover plate. The ratchet and pawl are cooperable to move between a primary engagement position to hold the striker in the channel, a secondary engagement position to hold the striker in the channel, and a released position to permit the striker to exit the channel. The ratchet and pawl are biased toward the primary and secondary engagement positions. The pawl is pivotable about a pawl axis. A secondary pawl is pivotally mounted to the housing on an axis offset from the pawl axis. The secondary pawl is kinematically coupled at a first end to the pawl, and has an out-of-plane tab mounted to drive the pawl. The secondary pawl is mounted to drive the pawl in a rotational direction opposite to the pawl.
In another aspect of the invention there is a latch for an automotive vehicle. It has a housing and a ratchet and pawl pair. The ratchet and pawl are rotatably mounted to the housing and are co-operable to move between a mutually engaged position for holding a striker and a released position. There is a secondary pawl, rotatably mounted to the housing and operable to actuate the pawl to release the ratchet. The pawl and secondary pawl each have a center of rotation and a center of gravity. The centers of rotation and centers of gravity are substantially coincident for the pawl and the secondary pawl respectively.
In a further aspect of the invention there is an automobile latch core for mounting between an outside enclosure member and an inside backing plate in a mechanical sandwich having a fishmouth for admitting a matably engageable striker. The latch core includes a substrate; a ratchet and ratchet biasing member; a pawl and pawl biasing member; and at least a first status sensor member and an associated first status sensor switch. The substrate has accommodations for the ratchet, the ratchet biasing member, the pawl and the pawl biasing member, and for the first status sensor member and the first status sensor switch. The latch core has a fishmouth. The latch core has an inner end of the fishmouth having cinched striker center position. Excluding indexing protrusions and fishmouth wear members, the latch core has a predominant width, W, longitudinally endwardly of the cinched striker center position, a length L from the striker center position to the fishmouth end, and a through thickness t between the outside enclosure member and the backing plate wherein W is less than 65 mm, L is less than 35 mm, and t is less than 20 mm.
In a further feature of that aspect of the invention, (a) W is less than 60 mm; (b) L is less than 32 mm; and t is less than 16 mm. In a still further feature, (a) W is less than 60 mm; (b) L is less than 32 mm; and (c) t is less than 16 mm. In a yet further feature, W is in the range of 50-55 mm; L is in the range of 25-32 mm; and t is less than 15 mm.
In another aspect of the invention there is a method of operating a latch for an automobile, the latch having a housing having a slot for receiving a striker, a cooperating ratchet and pawl pair mounted to the housing, and at least one sensor and sensor switch pair mounted to the housing, wherein the method includes using the sensor to check directly for the presence of a striker in the slot, and driving the ratchet to cinch the striker when there is a signal that the striker is present in the slot.
In still another aspect of the invention there is a latch for an automobile, the latch having a housing having a slot for receiving a striker, a co-operating ratchet and pawl pair mounted to the housing, and at least one sensor and sensor switch pair mounted to the housing, the sensor being mounted to monitor directly for the presence of a striker in the slot, and the latch is operable to drive the ratchet to cinch the striker in response to a signal from the switch that the striker is present in the slot.
In a further feature of that aspect, the latch has both a first sensor member and a second sensor member monitoring for the presence of a striker in the slot. In another feature, the first sensor member monitors for striker presence in at least an entrance portion of the slot, and the second sensor member monitors for striker presence in at least an innermost portion of the slot distant from the entrance portion.
In still yet another aspect of the invention, there is a latch core substrate for a latch assembly of an automobile. The substrate is formed of a molded monolith. The substrate includes accommodations for at least a ratchet, a pawl, a first status sensor member, and an associated first status sensor switch. The substrate includes an integrally formed movable member interposed between the accommodation for the first status sensor switch and the first status sensor member. The movable member is positioned to be acted upon by the first status sensor member; and the movable member is positioned to act upon the first status sensor switch when acted upon by the first status sensor member.
In a still further aspect of the invention, there is a latch core substrate for a latch assembly of an automobile. The substrate is formed of a molded monolith having a striker motion accommodating slot defined therein. The substrate includes accommodations for at least a ratchet, a pawl, a first status sensor member, and an associated first status sensor switch. The substrate includes a first fitting array defining a first latch core layer, the first latch core layer including the accommodations for the ratchet and the pawl. The substrate includes a second fitting array defining a second latch core layer, and the second latch core layer includes the accommodation for the first status sensor member.
In a further feature, the substrate includes fittings defining a third latch core layer. In another feature, the third layer has fittings defining a snowload lever seat. In another feature, the substrate includes communication passages between at least two of the layers.
In still another feature, there is a latch core for a latch assembly of an automobile, the latch core including the aforesaid substrate, a ratchet, a pawl, a first status sensor member, and an associated first status sensor switch each seated in its respective accommodation. The first status sensor member being operable to sweep through a range of motion, the range of motion overlapping at least part of the striker motion accommodating slot. The first status sensor member being operable independently of the ratchet. The first status sensor member is operable independently of the pawl.
In another aspect of the invention there is a latch for an automobile. The latch has a housing having a slot for receiving a striker; a co-operating ratchet and pawl pair mounted to the housing; a first sensor and associated first sensor switch mounted to the housing; and a second sensor and associated second sensor switch mounted to the housing. The first sensor is mounted to obstruct the slot, and is movable from the slot by the striker, the first switch being operably connected to change state on movement of the first sensor. The second sensor being a pawl position monitoring sensor.
In a feature of that aspect, no sensor of the latch is connected to monitor ratchet position. In another feature, there is a method of operating the latch, that includes (a) monitoring for a change of state of the first switch to signify the presence of a striker in the slot; (b) monitoring the second switch for the presence of a state associated with the presence of a bias of the pawl to engage the ratchet and prevent opening movement thereof; and (c) driving the ratchet toward the closed position when conditions (a) and (b) are satisfied. In another feature there is a method of releasing the latch including driving the pawl release to a release position; polling the first switch for a change in state signifying outward motion of the striker; polling the second switch for a change of state signifying arrival of the striker at a fully released state.
In another aspect of the invention there is a latch core for a latch assembly of an automobile. The latch core has a mounting substrate having a striker motion accommodating slot formed therein; a ratchet, a pawl, a first status sensor member, and an associated co-operable first status sensor switch each seated in a respective accommodation of the mounting substrate. The first status sensor member is operable to sweep through a range of motion that overlaps at least part of the striker motion accommodating slot. The first status sensor member is operable independently of the ratchet and independently of the pawl.
The various aspects of the invention may also include the use, or methods of use of the apparatus shown, described, or claimed herein. These and other aspects and features of the invention may be understood with reference to the description which follows, and with the aid of the illustrations of a number of examples.
The description is accompanied by a set of illustrative Figures in which:
a and 1b provide tables showing a prior art switching strategies;
a shows a manual release module mounted to the latch core of
b shows a power release module mounted to the latch core of
a is a side plan view for the power release module shown in
b is a side plan view for the power release module shown in
e is a side plan view for the power release module shown in
d is a side plan view for the power release module shown in
a is a side plan view for a power cinching and release module in the cinched position for the modular latch shown in
b is a side plan view for a power cinching and release module in the power release position for the modular latch shown in
a shows a top plan view of the latch core shown in
b shows a top plan view of the latch core shown in
a shows a top plan view of the latch core shown in
b shows a top plan view of the latch core shown in
c shows a top plan view of the latch core shown in
d shows a top plan view of the latch core shown in
a shows the bottom plan view of the latch core shown in
b shows the bottom plan view of the latch core shown in
c shows the bottom plan view of the latch core shown in
d shows the bottom plan view of the latch core shown in
a shows an exploded view of an alternate door latch assembly to that of
b is an assembled isometric view of the door latch assembly of
c shows a side view of the latch assembly of
d shows a view of the latch assembly of
e shows the latch assembly of
f shows the latch core of
g is a section of the latch assembly of
h is a section of the latch assembly of
i is an enlargement of
a is an isometric view of an alternate embodiment of latch assembly to that of
b is a side view of the latch assembly of
c is a top view of the latch assembly of
d shows the latch assembly of
e shows the latch assembly of
f shows the latch assembly of
g shows an end view of the latch assembly of
h shows the latch core of
a is a top isometric view of a latch core housing common to the latch cores of
b is a bottom isometric view of a latch core housing common to the latch cores of
c is a top plan view of the latch core housing of
d is a bottom plan view of the latch core housing of
e is a side view of the latch core of
a shows the latch core of
b shows the latch core of
c shows the latch core of
d shows the latch core of
a shows a logic chart for cinching of the latch core of
b shows a logic chart for the release cycle of the latch core of
The description that follows and the embodiments described therein are provided by way of illustration of an example, or examples, of particular embodiments of the principles, aspects or features of the present invention. These examples are provided for the purposes of explanation, and not of limitation, of those principles and of the invention. In the description, like parts are marked throughout the specification and the drawings with the same respective reference numerals. The drawings are generally to scale unless noted otherwise, although the scale may differ from drawing to drawing. Reference to directions such as up and down, front and back, left and right, top and bottom, may tend to be arbitrary, and these terms may be used for convenience rather than to define a required orientation, unless noted otherwise. The terminology used in this specification is thought to be consistent with the customary and ordinary meanings of those terms as they would be understood by a person of ordinary skill in the automobile industry in North America. The Applicant expressly excludes all interpretations that are inconsistent with this specification.
A specially-adapted mounting plate 14 is used to mount latch core 12 to the vehicle. Mounting plate 14 is used for the liftgate latch 10a, mounting plate 14b is used for the decklid latch 10b, and mounting plate 14c is used for the sliding door latch 10c. References made to mounting plate 14, as opposed to mounting plate 14a, 14b or 14c describe features held in common between all different configurations of mounting plate 14. Mounting plate 14 may be a stamped metal component that includes the required flanges and fastener holes to mount it to the vehicle body, and is shaped to present the latch core 12 to a striker (not shown) to secure the latch. A latch module 16 is mounted to the latch core 12 for all of the different configurations of modular latch 10. Additionally, there a number of different latch modules that each provide a specific functionality to the various latch configurations. Latch module 16a provides for manual release of latch 10 only. Latch module 16b provides for both power release and manual release of latch 10. Latch module 16c adds power locking and unlocking to the functionality of latch module 16a. Latch module 16d adds power cinching and release to the features described above. The various types of latch modules 16 will be described in greater detail below.
Latch core 12 is shown in greater detail in
A compartment 28 is formed between housing 18, and sidewalls 19 and substrate 22 of mounting plate 14 to house various latch components. A ratchet 30 and pawl 32 are mounted within compartment 28. Ratchet 30 and pawl 32 may be made of metal, which may be covered with, or encapsulated in a plastic material to some extent to reduce noise during operation. Certain portions subject to wear, such as the ratchet teeth are not covered by plastic. A tapering channel, referred to as a “fishmouth” 34 bisects substrate 22. In operation, fishmouth 34 receives a striker 35 (
Ratchet 30 is pivotally secured to substrate 20 by a ratchet rivet 42 inserted into aligned holes provided in substrates 20, 22 and ratchet 30. Ratchet 30 is pivotable between a “primary engagement”, or fully clinched, position (
Pawl 32 is pivotally mounted to substrate 20 by a pawl rivet 52 inserted into aligned holes in substrates 20, 22, and pawl 32. Pawl 32 is movable between an “engaged” position where it abuts either primary tooth 31 (
A secondary pawl 60 is pivotally mounted the side of housing 18 opposite substrate 20 along axle 62. A first end 64 of secondary pawl 60 is kinematically coupled with pawl 32 within an aperture 65 in housing 18 (
Referring now to
As noted above, latch module 16 is mounted to latch core 12 to provide release, power locking or cinching functionality, or all of them.
Latch module 16b includes all the features described above for latch module 16a, in addition to the following. An actuator 150 is mounted to a second side 151 of brain plate 100. Actuator 150 is electrically connected to the vehicle's power supply (not shown), and drives an orbital cam 152, which extends through an aperture 154 (
Referring now to
Latch module 16c includes all the features of latch modules 16a, in addition to the following features described below. With latch module 16c, release lever 120 is replaced with release lever 120c and auxiliary release lever 160, which is pivotally and coaxially mounted around axle 122 on release lever 120c. Auxiliary release lever 160 is operable to actuate the depending tab 68 on secondary pawl 60. A lock and unlock lever 162 acts as the lock and unlock output shaft of the actuator 150c. Actuator 150c includes a reversible DC motor, and engaging actuator 150c moves locking lever 162 between a locked position (
Referring now to
A sector arm 211 is coaxially mounted over sector gear 202 on axle 203 and operable to pivot independently of sector gear 202. A pin 212 extends through a slot 213 in sector gear 202 and a straight slot 214 in sector arm 211. Slot 213 in sector gear 202 has a generally arcuate portion 213a, and a leg portion 213b that extends outwards. A spring 215, mounted around a post 216 on sector arm 211 biases pin 212 to sit leg portion 213b. Thus, under normal operating conditions, the rotational movements of sector gear 202 and sector arm 211 are coupled, and the two pivot together in tandem.
Latch module 16d uses a four-bar cinching assembly to transfer the loading force from sector gear 202 to ratchet 30. As is best seen in
In
Manual release is provided by actuating the release cable 146d, which pivots release lever 120d. A tab 226 on release lever 120d abuts against a tab 228b on an auxiliary release lever 230, which then actuates the depending tab 68 on secondary pawl 60 to release the latch. As release cable 146 returns to its resting position, release lever 230 returns to its resting position, with tab 226 located between tabs 228a and 228b under the load from auxiliary release lever 230 and spring 233.
Electrical power may fail during a power cinch or power release actuation, leaving sector gear 202 out of its resting position, and ratchet 30 located midway between positions—potentially hindering future operation of the latch. To prevent this, a reset function is provided by manually engaging release lever 120d. Referring now to
For power cinching and release, the actuator needs to know the location of the striker 35 within the fishmouth 34, position of the ratchet (i.e., primary engagement, secondary engagement, or release position) and pawl (engaged or disengaged), in order to know when to start, and how long to drive actuator 150d. Typical prior art latches used a switch that is triggered by the pivotal movement of the ratchet (either on an external edge of the ratchet, or on a linked axial cam), to indicate that the striker is engaged and that power cinching should begin (as shown in
Referring now to
An ajar switch 252 is also provided within core latch 12. Ajar switch 252 is actuated by a switch arm 254 on secondary pawl 60 (
Switch arm 254 on secondary pawl 60, by itself, will provide a control logic identical to the prior art pawl switch described in
The switching strategy described herein may tend to avoid problems found in earlier latches. Unlike the switching strategy of
Referring back to
Latches may fail to open when an unusually heavy load is applied to the closure panel. Lift gates are particularly problematic, as they can easily be weighed down with snow or ice, and a greater force is required to lift them. If the striker does not immediately clear the fishmouth, the pawl might drop back into place. A snow load lever can help obviate the problem. Referring now to
b shows compartment 86 on latch core 12, when pawl 32 is released, but ratchet 30 does not move due to a snowload condition. When pawl 32 is released, secondary pawl 60 rotates in an opposite sense. As secondary pawl 60 rotates, a shoulder 276 on the secondary pawl 60 catches hook 270. Secondary pawl is now prevented from rotating back to the resting position, leaving pawl 32 actuated.
c shows compartment 86 on latch core 12, when the ratchet 30 moves to reset the snowload. This occurs when the decklid (or other closure panel) is manually opened. The manual door (not shown) opening pulls the striker out of the fish mouth 34, which rotates ratchet 30 to the released position. The rotation of the ratchet moves the four-bar assembly. A cam arm 278 on cinch axle 216 engages release arm 272, thereby pivoting snow load lever 264 in the direction of releasing hook 270 from shoulder 276.
d shows compartment 86 on latch core 12, pawl 32 returns to its normal resting position. With snow load lever 264 out of the way, secondary pawl 60 is free to return to its resting position, moving pawl 32 back to its resting position.
a-22i show an alternate embodiment of latch or latch assembly, indicated generally as 300. Latch 300 may be an automobile latch suitable for use in cars and trucks, as may be. As with latch 10, latch 300 in effect designates not merely a single latch, but rather a latch assembly system, in which a relatively small number of common major components can be assembled to yield a series of different products such as those of the matrix of
In each instance there is a latch core, 320 sandwiched between a first external enclosure member, or casing, or shell, or cover, such as may be identified in the illustrations as housing 322, and a second external enclosure member, which may have the form of an opposed backing wall, or plate, or cover, and is identified as wall member 324. It may be that wall member 324 serves not only as an enclosure, but also as an adapter or base plate 326 having fittings, sockets, seats or accommodations to which other modules may mount according to the functional requirements of the overall latch assembly. While the various base plates may have portions having overlapping common functionality and morphology (i.e., layout), they may also differ according to the seats or accommodations required.
There is a latch core envelope 330 between the members that define the external enclosure of the latch, be it 10 or 300. Envelope 330 exists whether the latch is to be used for a trunk, a gate, a lid, or a sliding door. Latch core 320 has a size and shape for containment within an envelope suitable for mounting (a) to a multiplicity of different brands of automobiles; and (b) to a multiplicity of configurations. That is to say, core 320 (and, for that matter, core 10, may fit within the intersection set of latch core envelopes for gate, door, and sliding door applications for a multiplicity of brands of automobiles, such that the same latch core components may be supplied to different manufacturers and different models of cars and trucks, and different applications in those models.
In the examples of
For the purpose of this discussion, the latch core envelope will be considered to be the volume that is (a) inside housing 332 as if relief 340 had not been made, but that peripheral wall 336 and base wall portion 338 were formed on continuous tangents or planes, or smooth curve conforming to their general shape; and (b) inside base plate 326. Also for the purposes of this discussion, it may be noted that various shaft or rivet ends, fastening tangs or tabs or clips of latch core 320, may extend outside this envelope, particularly to the extent that those features define attachment or location fittings by which latch core 320 is mounted to the cover, namely housing 332. However, in addition to fitting through the projected footprint outline noted above, latch core 320 also fits within an envelope, or envelope criterion, as discussed below.
An envelope 330 may include a first portion 342 and a second portion 344. First portion 342 may be termed the “bifurcated portion”, and is defined by a width W342, measured in the y-direction; a through-thickness H342, measured in the z-direction; and a length, L342 measured in the x-direction. It may be noted that the x-y plane in this reference co-ordinate system is oblique relative to the plane of flange surface 337. The angle of inclination may be in the range of 20 to 40 degrees, and, in one embodiment may be about 30 degrees. A closed position striker axis C346 is defined as an axis running perpendicular to base wall portion 338 at the center of curvature of the major radiused portion of the cul-de-sac end 346 of relief 340. This approximates the centerline of the striker when the latch is fully closed, and, if there is no end radius of curvature from which C346 may be determined then C346 should be taken as the design centerline of striker 35 in the closed position. L342 is defined as the length between axis C346 and the plane of the inside endwall portion of depending peripheral wall 336. In one embodiment L342 is less than 32 mm, and, in another embodiment is between 25 and 32 mm, and, in still another embodiment is between about 28 and 30 mm. Including the wall thickness of the endwall portion of depending wall 336, the overall lengths may be less than 35 mm in the first instance, between 30 and 35 mm in the second instance, and between 30 and 32 mm in the third instance. L342 may be termed the fishmouth travel length. W342 may be taken as the inside width between the major or predominant substantially parallel and substantially planar portions of the sidewall portion 338, and, if there is no such predominant portion, then the general wall width spacing taken in the plane normal to L342 that intersect C346. This dimension may be less than 65 mm or 70 mm, and, in some embodiments may be about, or less than 60 mm. H342 is the predominant through thickness clearance dimension between base wall portion 338 and wall member 324 in the region between C346 and the open end of the fishmouth. This dimension does not include protruding asperities such as rivet heads, attachment tangs or tabs, or the ends of shaft or pivot members that seat in either member 322 or member 324. Conceptually H342 defines the through thickness of the zone in which moving internal parts in the lower two layers of latch core 320 may swing or rotate. As may be appreciated, the envelope could also be defined in terms of the outside dimensions of the cover 322, and the position of its flange 334.
As seen in
Housing 350 has a first face or side 370 and a second face or side 372. First side 370 will arbitrarily be designated as the down side, and, as installed, faces toward base wall portion 338. By contrast, second side 372 will be designated as the up side, and, as installed faces away from base wall portion 338. Considering also the isometric views of
The underside of housing 350 also has an array of fittings, or accommodations, or mountings that include primary (or pawl) and secondary (or striker) switch seats, 390, 392, into which a primary (or pawl) switch 360 and secondary (or striker) switch 394, respectively, may seat. A manually operated latch assembly, such as that version of latch core 320 shown in
The main body of secondary pawl 358 occupies an accommodation 398 sunken into the top side of housing 350. Secondary pawl 358 is mounted on a common axis in the primary pawl 356, the two being located on either side of housing 350. Depending foot 412 of secondary pawl 358 extends through motion clearance part 408 in housing 350 to seat within socket 378 of pawl 356. Secondary pawl 358 also has an actuation input in the form of a lug 410 that protrudes upwardly from cover 324 for connection with such release input signal device or actuator as may be employed. Lug 410 may be located at the far end of secondary pawl 358 distant from foot 412. Between lug 410 and its pivot shaft or pin (i.e., rivet 355) secondary pawl 358 may have a primary switch contact member in the nature of an extending wing, or cam, or arm, identified as a horn 409. As installed in the illustrated embodiments, horn 409 extends, and travels, in a plane beneath the plane of snowload lever 366. In this context, pawl 358 may itself have the function of a latch status sensor member since the position of secondary pawl 358 is a signal of the position of pawl 356, and hence of one element of the status of the latch.
Housing 350 also has a fitting, seat, mounting or accommodation 418 for striker primary switch lever 361, that accommodation including a boss 420 onto which a mating socket of striker primary switch lever 361 seats, thus defining a pivoting connection. Striker primary switch lever 361 has three arms extending away from the central socket. The first arm 414 of lever 361 may be considered the output arm, and is pivotally biased by spring 363 to bear away from primary switch 360. The second arm, 416, is similarly biased to protrude into the inner end of the fishmouth, and to be displaced therefrom when the striker occupies its fully cinched position. The third arm may be a counterweight arm.
Housing 350 includes an accommodation, or fitting, or mounting, or seat, for striker secondary switch lever 362, in the form of a land 400 having a bore 401 into which a pivot axle or shaft in the form of a switch lever rivet 363 is mounted. There is an adjacent opening 405 that accommodates a motion transfer lug 404 of lever 362 that interacts with snowload lever 366. Spring 363 biases major arm 422 to a default position in which it obstructs the fishmouth. I.e., introduction of a striker 35 into the fishmouth deflects arm 422 (the leading edge of arm 422 acting as a cam surface, in effect). This causes the second arm 430 of the lever to move, and, ultimately, to cause a change of state of second switch 394. Thus lever 362, functions as a status sensor member with respect to the position of the striker, and provides output to (a) the secondary switch 394; and (b) the snowload lever 366, for which it acts as a reset arm.
Inasmuch as there may be a potential tolerance mis-match between arm 430 and the contact of switch 394, housing 350 includes an integrally formed movable partition member 432. Member 432 may have the form of a molded or living spring. The molded spring may have a relatively broad end, or paddle 434 located between switch 360 and horn 409 of secondary pawl 358; and also between switch 360 and arm 414 of striker primary switch lever 361. The paddle provides a relatively large target front or first surface, or land, against which horn 409, or arm 414, or both, can act, and is sufficiently torsionally stiff that member 432 has effectively a single degree of freedom—namely deflection in the direction of action of switch 360. The second, or back surface of paddle 434 acts against switch 360. Partition member 432 may have an at rest position clear of switch 360, and so is spring loaded when deflected, and therefore has a default bias away from switch 360.
The logic of operation of switch 360 is thus that disengagement of pawl 356 in response to either (a) inward cinching motion of either of the ratchet toes against the cam surface defined by the back face of tooth 380; or (b) a release input deflection of lug 410 (such that hook 380 of pawl 356 is clear of the path of the stop, or finger, or abutment 381 of the first arm 382 of ratchet 352, and clear of the path of abutment 383 of the second arm 384 of ratchet 352, thereby permitting the ratchet to be driven to its open position, releasing the striker), will cause a mechanical input signal to be transmitted as horn 409 to pushes against member 432, depressing the contact of switch 360. Alternatively, the default bias of striker primary switch lever 361 will cause arm 414 to depress the contact of switch 360. To obtain a change of state from this condition, namely to have arm 432 spring away from switch 360, both contact inputs must be removed. That is, for switch 360 to change from the ‘On’ (a) lever arm 416 of a striker secondary switch lever 361 must be displaced by a striker, and pawl 356 must be in the engaged (i.e., passive or inactive default condition under its default biasing spring). The practical effect of this logic is that switch 360 will not have a temporary bump (such as might otherwise shut off a cinch drive motor) when the ratchet teeth bump past hook 380 during cinching to a closed position; and in the event that there is a tip-on-tip engagement of hook 380 with one or the one or the other of the ratchet teeth, the mechanism will tend not, erroneously, to infer that cinching is complete, but rather to continue driving until lever arm 416 is displaced. This is possible, in part, by having both the primary and secondary striker switches (a) have ranges of motion that overlap (and, in default obstruct) the fishmouth, whence they can be displaced on introduction of the striker; and (b) by making the levers thin and overlapping in the z direction to share a single accommodation layer by locally occupying only half of that layer. Member 432 thus becomes a summing bar, or a logical AND in the away direction, or a logical OR in the toward direction. In the release mode, an electrical controller may count the time interval following a release signal being given, and if it exceeds a threshold value without a change of state at switch 360, such as half a second or a second, may infer that something is preventing the latch from opening, or that there is a fault.
Further, there are two striker status sensors. The primary sensor monitors whether the striker has reached the end of its range of travel and is seated in the fully cinched, or closed position at the inner end of the fishmouth. The other sensor changes state when the striker is near or at the beginning of its range of motion along the fishmouth moving inwardly (or at the end of its range of motion, moving outwardly). This may occur at the same time, or about the same time that ratchet 352 reaches the secondary position (i.e., toe 381 is rotationally inside the grasp of hook 380). Expressed differently, member 362 is used to sense the presence of the striker in the fishmouth slot along substantially its entire range of motion between the secondary position or condition, and the fully cinched or closed position or condition. Member 361 uses a different portion of the range of motion of the striker—namely the fully cinched, or closed, or primary, position only. Thus the change of state of switch 394 on release effectively signals that the striker has passed, or is passing, the secondary position on its way to the fully released position.
a-23g show a latching assembly 450 that includes a version of latch assembly 320 having a release input, as at 452, and a power cinching input, as at 454. This mechanism includes an externally accessible input interface, in the nature of a crank or crank assembly 456 that is accessible from inside the vehicle—i.e., from above the plane of flange 337. Crank 456 may be driven by pulling on a cable 458. Crank 456 includes a pivot member, or axle, or shaft 460 that extends into the latch body, and which may be termed a rivet, notwithstanding its function as a driven torsion rod or shaft. This shaft is perpendicular to the planes of swinging motion of the ratchet and pawl. A return spring 462 biases crank 456 to the inactive, or disengaged, state. The bottom, or inner end of crank 456 includes an output lug 464. In contrast to the four bar linkage described above, the cinching mechanism includes a connecting link, in the form of a push rod is identified as finger 466. While pinned at one end to lug 464, the other, far or distal end 468 is not pinned to ratchet 352. Ratchet 352 has a mating interface, or female socket, or accommodation identified as horn 470, for receiving, and engaging, end 468. This is a uni-directional force transfer interface: end 468 can exert a push across this interface, but cannot exert a pull. Thus there is a drive train, or force-transmission path, from the cinching input to ratchet 352. The crank assembly passes in the z-direction clear through the accommodation or relief 386 formed in the carrier, housing 352. The positions of the ends of crank assembly are fixed in the x and y directions by locating holes in the cover plate and in the backing plate, i.e., members 322 and 472, and the position in the z-direction is established by the height at which lug 464 is fixed on shaft 460. The cinching mechanism is activated when a striker is detected in the fishmouth (with the corresponding change in state of secondary switch 394, and the logic of the position indicates that the latch is moving from an open to a closed condition.
Another feature of the core body is a pawl release signal sustainer, more commonly referred to as a snow load lever 366. As before, housing 350 includes a snowload lever accommodation, 480, in this case between housing 350 and the upper, or back plate member 324 or 472 (as may be) that includes a seat, or fitting or mount identified as boss 484. Boss 484 mates with a corresponding bore of snow load lever 366, so defining a pivoting connection. When the release mechanism is actuated, as, for example, by pulling lug 486 of secondary pawl 356, the default spring bias of snow load lever 366 causes its first end 488 to rotate to block the return motion of the release actuator. When, however, the state of the striker switch lever pivots on release motion of the striker, its upstanding lug bears against the second end 490 of lever 366, returning it to its normal, passive, disengaged position, and the release actuator returns to its home, or inactivated, position. This prevents reset of the secondary pawl unless the door (e.g., a trunk lid) has actually moved. The presence of the snowload lever, may be associated with the formation of an upward step in the top or back cover plate, 324, as at 482, immediately inboard of the overslam bumper.
The body of member 350 has a number of other features. First, it has downwardly protruding locating boss 494 by which the x and y location of member 350 is fixed relative to the cover, housing 322. It also has indexing features, such as an upstanding tang or abutment wall 496 and keying rebates 498 by which the x and y location of backing plate member 324 is fixed relative to member 350. Further, as may be noted member 350 has the bifurcation, generally indicated at 500 that defines the wide-mouthed, progressively tapering fishmouth accommodation for striker 35. Member 350 includes a striker, or wear surface, or wear surface portion, or portions, in the thickened inlet wall portions 502, 504 that define the inlet guideway. Inasmuch as member 350 may be made of an high density plastic, wall portions 502, 504 may contribute to a lessening of latch noise. The inward end of the fishmouth is generally rounded, as at 506 in a manner generally corresponding to that of the cover, namely member 322. By their nature, portions 502 and 504 are intended to stand proud of all other structure, so that they are encountered by the striker in preference to any other structure, and so protrude from, or be roughly flush with, the cover, i.e., member 322 in both the x-direction as at the open end of the fishmouth, and in the z-direction, where they overlap the cut edges of the cover plate. To that extent, these portions extend beyond the footprint, or envelope of the latch core proper. That envelope is defined by peripheral side wall portions 510, 512, and by peripheral end wall portions 514, 516 as if a continuous tangent plane, P, extended between them.
a-25d show a progression of steps in closing.
This is seen in the logic of
The release cycle is shown in
In this description, reference is made to a change of state of the switches. It is in large measure arbitrary whether a switch is nominally “ON” or nominally “OFF” for the logic of operation of the latches described above to apply. It is perhaps more to the point to indicate that operation of the various releases, locks, drives, and mechanisms depends on the switches having a first state and a second state, and that the system is responsive to changes of state of the switches, as described. The first switch state may be ‘ON’ and the second switch state may be ‘OFF’ in some embodiments, and the reverse in others, without changing the underlying logic.
The latch core, be it 12 or 320, is thus mounted between an outside enclosure member e.g., 322, and an inside backing plate e.g., cover 324, in a mechanical sandwich having a fishmouth for admitting a matably engageable striker 35. The latch core has a substrate, namely housing 350; a ratchet 352 and ratchet biasing member; a pawl 356 and pawl biasing member; and a first status sensor member and an associated first status sensor switch, namely either the pawl sensor lever 361 or the striker status sensor lever 362. The substrate has accommodations for the ratchet, the ratchet biasing member, the pawl and the pawl biasing member, and for the first status sensor member and the first status sensor switch. The core may include a second latch core status sensor member (i.e., it has both 361 and 362), and an associated second latch core status switch, for which the substrate has accommodations. The striker status sensor member, 362, moves independently of both ratchet 352 and pawl 356. The striker position or status sensor member, 362, has a default bias toward obstructing said fishmouth. The ratchet and the pawl are pivotally movable in a shared layer. The sensor members are mounted in, and are movable in, a different layer. The ratchet and the striker status sensor have overlapping projected ranges of motion when seen normal to said layers. The substrate, namely housing 350, has a first set of fittings constraining motion of said ratchet and said pawl to a first layer; and has a second set of fittings constraining motion of the status sensor members to an adjacent layer. The first set of fittings includes a first substantially planar wall. The second set of fittings include a second substantially planar wall parallel to and offset from said first substantially planar wall. The status sensor members and the switches are mounted in said second layer. The substrate may also define a third layer. The third layer has a release signal maintaining member mounted therein, namely the snowload lever. The substrate may also have mechanical signal transmission passages formed therethrough, such as items 386, 405 and 408. The substrate is formed of a molded monolith, which may be plastic or metal.
The substrate may include and an integrally formed movable member interposed between the accommodation for the first status sensor switch and the first status sensor member. The movable member may be positioned to be acted upon by the first status sensor member. The movable member may be positioned to act upon the first status sensor switch when acted upon by the first status sensor member. The movable member may be wider than one or the other or both of the status sensor and the switch, and so may allow for any dimensional tolerance mismatch between them. The movable member may have the form of a living spring. It may be resiliently biased to a default position clear of said first switch. The substrate has a switch accommodation depth, and the movable member is constrained to deflect in a first degree of freedom in a direction cross-wise to that depth. The width corresponds substantially to the accommodation depth.
Further the substrate is formed of a molded monolith having a striker motion accommodating slot defined therein, namely the fishmouth. The first status sensor member, lever 362, is operable to sweep through a range of motion. The range of motion overlaps at least part of the striker motion accommodating slot. The ratchet and the first status sensor member are each mounted to pivot in a respective plane. The ratchet and the first status sensor member are not co-planar. The ratchet and the first status sensor member sweep out respective ranges of motion that are overlapping, and can sweep past each other. The substrate also includes fittings defining accommodations for a second status sensing member, namely lever 361, and a cooperable second status sensing member switch, namely switch 360, those accommodations being in a layer other than the first layer.
In summary, the latch core, be it item 320 or item 12, includes a matrix member that provides a locational datum, or frame of reference for the various moving members of the latch core (e.g., the ratchet, the primary and secondary pawl, the switch lever, or levers, and the switch, or switches. It may also provides a frame of reference for the snowload lever, if there is one, assembly, and either directly or indirectly provides a datum for the cinch mechanism, if there is one. The latch core is divided into layers, or levels. The matrix member may also define a geometric relationship of the parts such that the resulting assembly falls within a particular space envelope, such as a common denominator envelope between a range of latch types and uses.
In one layer, which may be the first or bottom layer, are the ratchet and pawl. In another layer, which may be a second layer, is the secondary switch lever, which detects the presence of a striker in the fishmouth. The primary switch lever may also be mounted to operate in the second layer, although it could, alternatively be mounted to operate in the first layer. The striker switch detection lever operates in a different layer, or plane from the ratchet. It pivots independently of the ratchet, and swings through a motion envelope that overlaps the motion envelope swept by the ratchet. To the extent that separate plane are defined for each layer, they may be defined as the planes of the center of these elements. The switches are in the planes, or layers of the respective switch levers. The snowload lever is in yet a third plane, or layer. To achieve this, member 350 has, in effect, a first level, or plateau or shelf, or array of surfaces that is parallel to the plane of motion of the ratchet and pawl.
This array of surfaces may include co-planar surfaces, and may include the ratchet boss and neighbouring land of one side or leg of the bifurcation; and pawl shelf of the other side or leg of the bifurcation. Member 350 also has a second shelf, or layer or array of surfaces, which may be recessed (or shy of) the surfaces of the first shelf or layer, and may include a recess and surface for the primary switch lever, and a recess or region and surface for the secondary switch lever, and surfaces, or regions on substantially the same plane on which the primary and secondary switches may mount. The switch levers and switches do not need to be mounted in the same plane as each other, and, the switch levers, or portions of them, may overlap and undergo movement with respect to each other about their respective pivots. Member 350 may also have a third shelf, or surface or array of surfaces such as may accommodate the parallel planar pivoting motion of secondary pawl 358, and a fourth surface, or array of surfaces such as may defined the location of the snow load lever. The matrix member may include appropriate pivot or fulcrum fittings, whether bores for shafts or bosses for sockets, for these various moving members, and may include motion or signal (or both) transmission passages between the various layers, whether those passages or openings allow for lost motion or not.
An latch function adapter plate, such as may be termed a brain plate, may be mounted to latch 300 in much the same manner as to latch 10. The choice of adapter plate will be determined by the desired function or functions and the cinching, locking, or other modules to be combined with it for a particular application as described above. In that context, the latch may be seen as a device having two input ports or signal receiving devices, those being the release and the cinch drive input; and two output or monitoring signals, those being the two switch states. In this circumstance, there may be more than two switch input sensor members, and it may be that none of the input sensor members is directly connected to, or directly monitors, ratchet position or operation.
The principles of the present invention are not limited to these specific examples which are given by way of illustration. It is possible to make other embodiments that employ the principles of the invention and that fall within its spirit and scope of the invention. Since changes in and or additions to the above-described embodiments may be made without departing from the nature, spirit or scope of the invention, the invention is not to be limited to those details.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/CA2008/000380 | 2/28/2008 | WO | 00 | 8/26/2009 |
Number | Date | Country | |
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60892031 | Feb 2007 | US |