Patent Description:
The present invention relates to the field of mechanical latches.

Latch assemblies are relied on in many applications for securing items such as panels, doors, and doorframes together. For example, containers, doors, cabinets, closets, drawers, compartments and the like may be secured with a latch. One type of latch assembly includes a rotary pawl or cam, which remains open until the pawl or cam impinges on a striker (or bolt). The relative displacement of the assembly with respect to the striker causes the rotary pawl to rotate and capture the striker. There exists a need for new rotary pawl assemblies having a design that is at least one of simpler, more compact, and cost-effective.

<CIT> illustrates for example a locking device that comprises a first hook cantilevered out from a rocking pin to support a catch member and bearing against a retractable locking member that opposes rocking movement of the first hook, and a second hook adjacent to the first hook and associated therewith by a link member so that when the first hook is closed, the second hook is kept in a position close to a position in which the second hook supports the catch member.

<CIT> describes a modular latch for an automotive vehicle. It includes a latch core which is a housing and a ratchet and pawl rotatably mounted to the housing, and a mounting plate that secures the latch core to the vehicle.

Further advantageous embodiments are defined in the dependent claims.

According to a first aspect of the present invention, a latch assembly comprises:.

According to another aspect of the present invention, a method for sensing the presence of a striker within a latch assembly, comprises sensing the presence of the striker bar when the striker moves the striker bar relative to the trigger, wherein the presence of the striker bar indicates that the pawl moved to the closed position and the trigger moved to the locked position.

The above and other aspects and features of the present invention will become more apparent to those of ordinary skill in the art by describing in detail exemplary embodiments thereof with reference to the attached drawings.

Although the invention is illustrated and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims and without departing from the invention.

Various terms are used throughout the disclosure to describe the physical shape or arrangement of features. A number of these terms are used to describe features that conform to a cylindrical or generally cylindrical geometry characterized by a radius and a center axis perpendicular to the radius. Unless a different meaning is specified, the terms are given the following meanings. The terms "longitudinal", "longitudinally", "axial" and "axially" refer to a direction, dimension or orientation that is parallel to a center axis. The terms "radial" and "radially" refer to a direction, dimension or orientation that is perpendicular to the center axis. The terms "inward" and "inwardly" refer to a direction, dimension or orientation that extends in a radial direction toward the center axis. The terms "outward" and "outwardly" refer to a direction, dimension or orientation that extends in a radial direction away from the center axis.

In the description, relative terms such as "horizontal," "vertical," "up," "down," "top" and "bottom" as well as derivatives thereof (e.g., "horizontally," "downwardly," "upwardly," etc.) should be construed to refer to the orientation as then described or as shown in the drawing figure under discussion. These relative terms are for convenience of description and normally are not intended to require a particular orientation.

Terms concerning attachments, coupling and the like, such as "mounted," "connected" and "interconnected," refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise.

The terms "proximal" and "distal" may be used herein as relative terms.

<FIG> depict a first exemplary latch <NUM>. Latch <NUM> generally comprises a rear frame member <NUM> and a front frame member <NUM> that are connected together by pins <NUM>, <NUM>, <NUM>. Taken together these components may be said to constitute a frame or housing. The frame members are (optionally) composed of bent sheetmetal, and may together be considered a housing for the latch <NUM>. Although not shown, additional fasteners may be included for fastening the frame members <NUM> and <NUM> together. The frame members <NUM> and <NUM> are spaced apart from each other by the pins <NUM>-<NUM> to form an interior space for accommodating the other components of the latch <NUM>. More particularly, a spring guide retention member <NUM> is positioned between the frame members <NUM> and <NUM>, and includes an opening <NUM> for receiving the pin <NUM>, as well as an opening <NUM> having a dovetail shape for receiving a spring guide <NUM> (as is described later). A pawl <NUM> is rotatably mounted to the pin <NUM>, and moves (i.e., rotates) between a closed position (<FIG>) and an open position (<FIG>). The pawl <NUM> includes an open C-shaped channel <NUM> that is sized and configured to accommodate and interact with a striker, as is known in the art. An opening <NUM> is provided in the pawl <NUM> to which a spring guide <NUM> is rotatably connected. The spring guide <NUM> is an elongated body having a first end defining a pin <NUM> that is rotatably positioned within the opening <NUM> in the pawl <NUM>. The second, opposite, end <NUM> of the spring guide <NUM> is substantially flat and is positioned to travel within an opening <NUM> defined in the member <NUM>. The end <NUM> moves in an unconstrained fashion within the opening <NUM> of the member <NUM> and without becoming detached from the member <NUM> as the pawl <NUM> moves between the open and closed positions. A compression spring <NUM> is positioned over the elongated portion of the spring guide <NUM>. One end <NUM> of the spring <NUM> is positioned to bear on a shoulder <NUM> of the opening <NUM> of the member <NUM>, while the opposite end <NUM> of the spring <NUM> is positioned to bear on the pin <NUM> of the spring guide <NUM>.

In the closed position of the pawl <NUM> shown in <FIG>, the spring <NUM> is configured to urge the pawl <NUM> in a counterclockwise position (as viewed in that figure) and to remain in the closed position. Conversely, in the open position of the pawl <NUM> shown in <FIG>, the spring <NUM> is configured to urge the pawl <NUM> in a clockwise position and to remain in the open position. Therefore, the latch <NUM> may be considered a bi-stable latch because the latch <NUM> can remain in the open position until it is moved to the closed position and can also remain in the closed position until it is moved to the open position. In other words, the latch <NUM> is stable in both the closed and open positions. The latch <NUM> is bi-stable at least in part because the pin <NUM> of the spring guide <NUM> is connected to the pawl <NUM> at a location whereupon, in the closed position of the pawl <NUM>, a force vector (see arrow in <FIG>) of the spring guide <NUM> urges the pawl <NUM> about its rotational axis toward the closed position. And, in the open position of the pawl <NUM>, a force vector (see arrow in <FIG>) of the spring guide <NUM> urges the pawl <NUM> about its rotational axis toward the open position.

To move the latch <NUM> from the closed position to the open position, the striker (not shown) is pulled away from the latch <NUM> (or vice versa) with sufficient force, thereby rotating the pawl <NUM> in the clockwise direction and against the bias of the spring <NUM>. At some point during rotation from the closed position to the open position, the spring <NUM> is positioned such that it urges the pawl <NUM> toward the open position. The striker eventually separates from the channel <NUM> of the pawl <NUM>, and the pawl <NUM> remains in the open position by virtue of the bias of the spring <NUM>. In the open position, the top end of the pawl <NUM> comes to rest against a bearing surface <NUM> that is formed on a tab of the frame member <NUM>.

To move the latch <NUM> from the open position to the closed position, the striker is moved into the channel <NUM> of the pawl <NUM>, thereby rotating the pawl <NUM> in the counterclockwise direction and against the bias of the spring <NUM>. At some point during rotation from the open position to the closed position, the spring <NUM> is positioned such that it urges the pawl <NUM> toward the closed position. Once the pawl <NUM> reaches the closed position, the striker is captivated within the channel <NUM> of the pawl <NUM>, and the pawl <NUM> remains in the closed position by virtue of the bias of the spring <NUM>. In the closed position, the bottom end of the pawl <NUM> comes to rest against a bearing surface <NUM> that is formed on a tab of the frame member <NUM>.

The latch <NUM> may be referred to as a "pull to open" and "push to close" type latch.

<FIG> depict a second exemplary latch <NUM>. The latch <NUM> is substantially similar to the latch <NUM> and only the primary differences between those latches will be described hereinafter. Latch <NUM> generally comprises a rear frame member <NUM> and a front frame member <NUM> that are connected together by pins <NUM> and <NUM> and/or other fasteners. An opening <NUM> is formed in the front frame member <NUM> for accommodating movement of a spring guide <NUM>. The end <NUM> of the spring guide <NUM> is substantially flat and is positioned to travel within the opening <NUM>. The end <NUM> has a cross-sectional area that is reduced as compared to a cross-sectional area of the elongated portion of the spring guide <NUM> that is located closer to the pin connector <NUM>. The end <NUM> moves within the opening <NUM> without becoming detached from the opening <NUM> as the pawl <NUM> rotates about the pin <NUM> between the open and closed positions. A compression spring <NUM> is positioned over the elongated portion of the spring guide <NUM>. One end <NUM> of the spring <NUM> is positioned to bear on the interior facing surface <NUM> of a tab formed on the frame member <NUM>, while the opposite end <NUM> of the spring <NUM> is positioned to bear on a pin connector <NUM> of the spring guide <NUM>. The pin connector <NUM> is rotatably coupled to an opening <NUM> formed in the pawl <NUM>, like the first exemplary latch.

A striker bumper <NUM>, which may be composed of a soft ductile material, is positioned between the frame members <NUM> and <NUM>. A concave top surface <NUM> of the bumper <NUM> is arranged to be contacted by the striker when the latch <NUM> is maintained in the closed position. In operation, the striker bumper <NUM> either prevents or limits bumps, squeaks and rattles.

In the closed position of the pawl <NUM> shown in <FIG>, the spring <NUM> is configured to urge the pawl <NUM> in a clockwise direction (as viewed in that figure) and to remain in the closed position. Conversely, in the open position of the pawl <NUM> shown in <FIG>, the spring <NUM> is configured to urge the pawl <NUM> in a counterclockwise direction and to remain in the open position. Therefore, like the latch <NUM>, the latch <NUM> may be considered a bi-stable latch because the latch <NUM> can remain in the open position until it is moved to the closed position and can also remain in the closed position until it is moved to the open position.

Although not shown, the latches <NUM> and <NUM> may also include a trigger, like trigger <NUM>, that is configured to retain the pawl in a locked position as well as release the pawl.

<FIG> depict a third exemplary latch <NUM>. In <FIG>, the latch <NUM> is shown interacting with an actuator <NUM> and striker assembly <NUM>. The actuator <NUM> may form part of a larger assembly including the latch <NUM>. Similarly, the striker assembly <NUM> may form part of a larger assembly including the latch <NUM> and/or actuator <NUM>.

The actuator <NUM> is (optionally) an electric solenoid that is configured to be connected to a power source and a computer controller by wires <NUM>. Upon receiving a command from the computer controller (not shown), the actuator <NUM> is configured to actuate (i.e., extend or retract or otherwise translate) a piston <NUM> from the end of actuator <NUM>, and the piston <NUM> is configured to interact with a trigger <NUM> of the latch <NUM>, as will be described later. Other types of actuators are known to those skilled in the art. Also, the actuator <NUM> may be omitted.

The striker assembly <NUM> includes an elongated rail <NUM>, and a striker <NUM> that is fixedly mounted to the rail <NUM> by a bracket <NUM> using fasteners. Rail <NUM> may be flat, as shown, or may be rounded, for example. The geometry and shape of rail <NUM> can vary. The rail <NUM> is movable with respect to the latch <NUM> in the direction of the arrows shown in <FIG>. Either the rail <NUM> moves with respect to latch <NUM>, or the latch <NUM> moves with respect to the rail <NUM>. The striker <NUM> is a cylindrical (or semicylindrical) member that is configured to interact with the pawl <NUM> of the latch <NUM>.

The latch <NUM> shares some similarities with the latch <NUM> and the primary differences between those latches will be described hereinafter. Referring now to <FIG> and <FIG>, latch <NUM> generally comprises a rear frame member <NUM> and a front frame member <NUM> that are connected together by pins <NUM> and <NUM> and/or other fasteners. The rear frame member <NUM> includes a mounting surface and opening <NUM> to which the actuator <NUM> (not shown in <FIG> and <FIG>) is mounted by fasteners (not shown). A pawl <NUM> has an opening through which the pin <NUM> is positioned, and the pawl <NUM> moves (i.e., rotates) about the pin <NUM> between a closed position (<FIG>) and an open position (<FIG>). A torsion spring <NUM> is mounted around the pin <NUM> and includes a first free end that is mounted on the rear frame member <NUM> (or other stationary feature) and a second free end that is mounted to a bearing surface on the pawl <NUM>. The spring <NUM> biases pawl <NUM> to the open position. A trigger <NUM> has an opening through which the pin <NUM> is positioned, and the trigger <NUM> moves (i.e., rotates) between a locked position (<FIG>) and an unlocked position (<FIG>). A torsion spring <NUM> is mounted around the pin <NUM> and includes a first free end that is mounted on the rear frame member <NUM> (or other stationary feature) and a second free end that is mounted to a bearing surface on the trigger <NUM>. The spring <NUM> biases trigger <NUM> to the unlocked position.

A spring member <NUM>, which is formed from a ductile and resilient material, is positioned at an elevation that is both above the frame member <NUM> and beneath the trigger <NUM> and pawl <NUM>. The spring member <NUM> includes four legs depending therefrom that urge the trigger <NUM> and the pawl <NUM> toward the frame member <NUM>, thereby preventing the trigger <NUM> and pawl <NUM> from rattling during operation. A spring arm <NUM> also extends from the spring member <NUM>. The spring arm <NUM> is a flexible curved member that is positioned to interact with a perimeter surface of the pawl <NUM>.

Specifically, as shown in <FIG>, in the closed position of the pawl <NUM>, the spring arm <NUM> is seated in a concave recess, indent or depression <NUM> formed on the outer perimeter of the lower side of the pawl <NUM>. The holding force exerted by the spring arm <NUM> onto the pawl <NUM> is greater than the force exerted by the torsion spring <NUM> such that the pawl <NUM> remains in the closed position even after the trigger <NUM> has been moved to the unlocked position (<FIG>). And, in the open position of the pawl <NUM>, the spring arm <NUM> is seated in another concave recess, indent or depression <NUM> formed on the outer perimeter of the lower side of the pawl <NUM>. It is noted that a plurality of depressions <NUM>/<NUM> are defined on the lower perimeter side of the pawl <NUM>. Once the pawl <NUM> is moved to the open position, the force exerted by the spring arm <NUM> onto the pawl <NUM> retains the pawl in the open position.

Therefore, like the latch <NUM>, the latch <NUM> also may be considered a bi-stable latch because the latch <NUM> can remain in the open position until it is moved to the closed position and can also remain in the closed position until it is moved to the open position.

In the locked position of the trigger <NUM> shown in <FIG>, a tab <NUM> extending from the perimeter of the trigger <NUM> bears on a bearing surface of the frame member <NUM>. Also, in the locked position, a v-shaped recess <NUM> formed along the perimeter of the trigger <NUM> is positioned within a correspondingly v-shaped projection <NUM> formed on the perimeter of the pawl <NUM>. Engagement between the recess <NUM> and projection <NUM> as well as the tab <NUM> and frame <NUM> prevents the pawl <NUM> from moving in a counterclockwise direction (as viewed in <FIG>) toward the open position.

The trigger <NUM> includes a control surface <NUM>, in the form of a bent projection, that protrudes from the latch <NUM> toward the actuator <NUM>. The control surface <NUM> is positioned to interact with the piston <NUM> of the actuator <NUM>. The piston <NUM> is configured to bear on the bearing surface <NUM> to move the trigger <NUM> from the locked position (<FIG>) to the unlocked position (<FIG>).

As shown in <FIG> and <FIG>, other control surfaces are envisioned. For example, in <FIG>, the control surface 227a has a hole or opening that may be connected to a cable (not shown), and the cable may be connected to an actuator (not shown) for pulling the cable to cause the trigger <NUM> to move from the locked position to the unlocked position. In <FIG>, the control surface 227b is provided in the form of a finger tab that is positioned on the top side of the trigger and is positioned to be accessed by (for example) a user for manually moving the trigger <NUM> to cause the trigger <NUM> to move from the locked position to the unlocked position.

Turning now to <FIG>, in <FIG>, the latch <NUM> is shown in a locked and latched state. In the locked and latched (i.e., closed) state, the latch <NUM> retains the striker <NUM> within the pawl <NUM>. If a user were attempt to move the striker <NUM> away from the latch <NUM> (e.g., by translating the rail <NUM>), the latch <NUM> would prevent the movement of the striker <NUM> and rail <NUM> because the trigger <NUM> would prevent the pawl <NUM> from rotating in a counterclockwise direction (as viewed in <FIG>) to the open position.

In <FIG>, the latch <NUM> is shown in an unlocked and latched state. To unlock the latch <NUM>, the computer controller actuates the actuator <NUM>, which causes the piston <NUM> of the actuator <NUM> to extend and bear on the control surface <NUM> of the trigger <NUM>, which causes the trigger <NUM> to rotate in a counterclockwise direction (as viewed in <FIG>) and against the bias of the spring <NUM>. Once the recess <NUM> of the trigger separates from the projection <NUM> of the pawl <NUM>, the trigger <NUM> is maintained in the unlocked position, and the latch <NUM> is unlocked. In the unlocked state of the latch <NUM>, the pawl <NUM> remains in the closed state by virtue of the engagement between the spring arm <NUM> and the pawl <NUM>.

In <FIG>, the latch <NUM> is shown in an unlocked and unlatched state. To move the latch <NUM> from the latched (i.e., closed) state to the unlatched (i.e., open) state, the user translates the rail <NUM> and striker <NUM> away from the latch <NUM>. The striker <NUM> moves the pawl <NUM> (which is unlocked) in the counterclockwise direction (as viewed in <FIG>) against the bias of the spring arm <NUM>. As the pawl <NUM> rotates, the spring arm <NUM> slides along the lower surface of the pawl <NUM>. The pawl <NUM> eventually releases the striker <NUM> as the striker <NUM> is moved away from the latch <NUM>. The pawl <NUM> remains in the open state by virtue of the engagement between the spring arm <NUM> and the detent <NUM> of the pawl <NUM>. At this stage, the trigger <NUM> remains in the unlocked state due to the engagement between the piston <NUM> and the control surface <NUM> of the trigger <NUM>.

In <FIG>, the latch <NUM> is shown in an unlocked and unlatched state. To return the trigger <NUM> to the locked position, the computer controller actuates the actuator <NUM>, which causes the piston <NUM> of the actuator <NUM> to retract and separate from the control surface <NUM> of the trigger <NUM>. The torsion spring <NUM> returns the trigger <NUM> to its locked position whereupon the tab <NUM> bears on the frame member <NUM>, as shown in <FIG>. At this stage, the pawl <NUM> remains open.

To return the latch <NUM> to the locked and latched state of <FIG>, the user moves the striker <NUM> toward the latch <NUM>. The striker <NUM> engages the opening in the pawl <NUM>, and the pawl <NUM> rotates in a clockwise direction (as viewed in <FIG>) against the bias of the spring <NUM>. The projection <NUM> of the pawl <NUM> rides on the perimeter of the trigger <NUM> (and causes slight rotation of the trigger <NUM> against the bias of the spring <NUM>) until the striker <NUM> bears on the frame members <NUM> and <NUM>. And, at which time the projection <NUM> of the pawl <NUM> becomes seated in the recess <NUM> of the trigger <NUM>. The latch <NUM> is then maintained in the locked and latched state of <FIG>.

Turning now to <FIG> and <FIG>, the latch <NUM>, actuator <NUM> and rail <NUM> may be employed as part of a multi-point latching system <NUM> for securing a door <NUM> to a door frame or other structure.

The multi-point latching system <NUM> comprises an actuator <NUM> in the form of a lever, handle or driver, for example. The actuator <NUM> is movable between a first position that corresponds to a locked state of the door <NUM>, and a second position that corresponds to an unlocked state of the door <NUM>, as is known in the art. The actuator <NUM> has an output end that is connected to the rail <NUM> of <FIG>. Moving the actuator <NUM> between the first and second positions causes the rail <NUM> to translate up and down, as is known in the art.

One or more of the striker assemblies <NUM> are connected to the rail <NUM>.

One or more pawls <NUM> (four shown) are individually connected to the door <NUM>. The pawls <NUM> may be pivotably mounted to the door <NUM>, for example. Specifically, each pawl <NUM> is connected to a cam <NUM> that pivots on the door <NUM>. Each pawl <NUM> is also connected to the rail <NUM>, such that translation of the rail <NUM> causes the cams <NUM> and the pawls <NUM> that are connected thereto to pivot between locked and unlocked positions. In the locked position, the pawls <NUM> are oriented such that they retain the door <NUM> to the door frame or other structure. And, in the unlocked position, the pawls <NUM> are oriented such that they do not retain the door <NUM> to the door frame or other structure.

One or more guides <NUM> are mounted to the door <NUM>. Each guide <NUM> may include a rectangular through-hole for receiving the rail <NUM>, in order to constrain the rail <NUM> in two translation degrees of freedom. One or more additional guides <NUM> are also mounted to the door <NUM>. Each guide <NUM> may include an open ended slot for receiving the rail <NUM>, in order to constrain the rail <NUM> in one translation degree of freedom.

One or more of the latches <NUM> are fixedly connected to the door <NUM>. Each latch <NUM> is configured to interact with a striker <NUM> that is mounted to the rail <NUM>, as was described previously. In the locked state of the latch <NUM>, the latch <NUM> restrains the striker <NUM>, as well as the entire multi-point latch system <NUM>, from moving. In the unlocked state of the latch <NUM>, the latch <NUM> does not prevent the striker <NUM>, as well as the entire multi-point latch system <NUM>, from moving.

Incorporating the latch <NUM> and striker <NUM> within the mechanical multi-point system <NUM>, even as a retrofit, yields an electrically locking system <NUM>. Accordingly, it is not necessary to substitute the mechanical actuator <NUM> with an electro-mechanical actuator. Also the push to close/pull to open style of the latch <NUM> allows the system <NUM> to remain closed even though the latch <NUM> is not locked. However, a remote signal can be transmitted to the latch <NUM> in order to lock the system <NUM>. More particularly, the spring arm <NUM> holds pawl <NUM> in a fixed position until the striker <NUM> is moved, thereby allowing electronic locking if the door <NUM> is not open.

Although the multi-point latching system <NUM> has been described for use with the latch <NUM>, it should be understood that the multi-point latching system <NUM> may incorporate any of the latches described herein without extensive modification.

<FIG> depict a fourth exemplary latch <NUM>. The latch <NUM> is similar to the latch <NUM> of <FIG>, and the primary differences therebetween will be described hereinafter.

The latch <NUM> generally comprises a frame or housing comprising a rear frame member <NUM> and a front frame member <NUM> that are connected together by fasteners or clips, for example. Various components are positioned within the interior space defined by the frame, and those components will be described hereinafter.

A pawl <NUM> includes co-aligned pins <NUM> that are positioned within openings <NUM> defined in the frame members. The pins <NUM> may be integral with the body of the pawl <NUM>, or may comprise one or more separate components that are mounted to the pawl <NUM>. The pawl <NUM> moves (i.e., rotates) about the openings <NUM> between a closed position (<FIG>) and an open position (<FIG>). The pawl <NUM> includes a concave area for receiving a striker, like the other pawls described above. A concave recess <NUM> (<FIG>) is formed along the perimeter of the pawl <NUM>, and a corresponding projection <NUM> is formed on the perimeter of the trigger <NUM>. Engagement between the recess <NUM> and projection <NUM> prevents the pawl <NUM> from rotating in a counterclockwise direction (as viewed in <FIG>) toward the open position.

An opening <NUM> (<FIG>) is provided in the pawl <NUM> to which a spring guide <NUM> is rotatably connected. The spring guide <NUM> is an elongated body having a first bifurcated connection end <NUM> that is rotatably positioned within the opening <NUM> in the pawl <NUM> by a pin <NUM> that is positioned through co-aligned holes in the bifurcated end <NUM>. The second, opposite, end <NUM> of the spring guide <NUM> is substantially flat and is positioned to travel within an opening <NUM> defined in the frame. The end <NUM> moves in an unconstrained fashion within the opening <NUM> of the frame and without becoming detached from the frame as the pawl <NUM> moves between the open and closed positions. A compression spring <NUM> is positioned over the elongated portion of the spring guide <NUM>. One end of the spring <NUM> is positioned to bear on a shoulder <NUM> (<FIG>) of the opening <NUM> of the frame, while the opposite end of the spring <NUM> is positioned to bear on the bifurcated connection end <NUM> of the spring guide <NUM>.

In the closed position of the pawl <NUM> shown in <FIG>, the spring <NUM> is configured to urge the pawl <NUM> in a counterclockwise position (as viewed in that figure) and to remain in the closed position. Conversely, in the open position of the pawl <NUM> shown in <FIG>, the spring <NUM> is configured to urge the pawl <NUM> in a clockwise position and to remain in the open position. Therefore, the latch <NUM> may also be considered a bi-stable latch because the latch <NUM> can remain in the open position until it is moved to the closed position and can also remain in the closed position until it is moved to the open position.

As best shown in <FIG>, the trigger <NUM> includes co-aligned pins <NUM> that are positioned within openings <NUM> (<FIG>, one shown) defined in the frame members. The pins <NUM> may be integral with the body of the trigger <NUM>, or may comprise one or more separate components that are mounted to the trigger <NUM>. In use, the trigger <NUM> moves (i.e., rotates) about the opening <NUM> (<FIG>, one shown) between a locked position (<FIG>) and an unlocked position (<FIG>). The axes of rotation of the trigger <NUM> and the pawl <NUM> are parallel. The trigger <NUM> includes a control surface <NUM> in the form of a leg that extends from the body of the trigger <NUM>. The control surface <NUM> is configured to be contacted by an actuator <NUM>, as will be described later, for moving the trigger <NUM> between the locked and unlocked positions. An opening <NUM> is defined in the body of the trigger <NUM> for accommodating the coiled portion of a torsion spring <NUM>. A pin (such as pin <NUM>) may be positioned through the coiled portion of the spring <NUM> to retain the spring <NUM> in place. One leg of the torsion spring <NUM> is positioned against the trigger <NUM> while the other leg of the torsion spring <NUM> is positioned against a stationary surface, such as a surface on the frame. The spring <NUM> biases trigger <NUM> to the locked position.

An actuator <NUM> is mounted to the frame and is configured to actuate (i.e., extend or retract or otherwise translate) a piston <NUM> from the end of actuator <NUM>. The actuator <NUM> is a solenoid, however, other types of actuators are known to those skilled in the art. Like the above described actuators, the actuator <NUM> is connected to the computer controller for control purposes.

As best shown in <FIG> and <FIG>, a cap <NUM> is connected to the piston <NUM> in a fixed manner such that the cap <NUM> moves with the piston <NUM>. The cap <NUM> has a J-shaped body <NUM>, a C-clip <NUM> mounted to the curved end of the body <NUM>, and a projection <NUM> that extends longitudinally and outwardly from the body <NUM>. C-clip <NUM> and projection <NUM> may be integrated with the body <NUM>, or those features may be separate components that are mounted to the body <NUM>. The C-clip <NUM> is connected to the piston <NUM> in a non-rotatable manner. The projection <NUM> is configured to interact with the control surface <NUM> of the trigger <NUM> of the latch <NUM>.

A sensor <NUM> is mounted to the frame, and is configured to detect one or more of the rotational position, presence or absence of the pawl <NUM> (and/or trigger <NUM>) and transmit a corresponding signal to the computer controller via a cable. The sensor <NUM> may be a switch, for example. Other means for sensing the closed or open state of the pawl <NUM> are known to those skilled in the art, such as magnetic sensors, proximity sensors, Hall-Effect sensor and optical sensors.

Turning now to the operation of the latch <NUM> shown in <FIG>, in <FIG>, the latch <NUM> is shown in a locked and latched state. In the locked and latched (i.e., closed) state, the latch <NUM> retains the striker within the pawl <NUM>. If a user were attempt to move the striker away from the latch <NUM> (or vice versa), the latch <NUM> would prevent the movement of the striker because the trigger <NUM> would prevent the pawl <NUM> from rotating in a counterclockwise direction (as viewed in <FIG>) to the open position.

In <FIG>, the latch <NUM> is shown in an unlocked and latched state. To unlock the latch <NUM>, a user instructs the computer controller to actuate the actuator <NUM>, which causes the piston <NUM> of the actuator <NUM> to retract. Alternatively, the computer controller may perform this unlocking step in response to an event, such as a vehicle being placed into the Park'P' position.

Upon retracting, the projection <NUM> on the cap <NUM> bears on the control surface <NUM> of the trigger <NUM>, which causes the trigger <NUM> to rotate in a counterclockwise direction (as viewed in <FIG>) and against the bias of the spring <NUM>. Rotation of the trigger <NUM> causes the projection <NUM> of the trigger <NUM> to separate from the recess <NUM> of the pawl <NUM>. Once the recess <NUM> of the pawl <NUM> separates from the projection <NUM> of the trigger <NUM>, the trigger <NUM> is maintained in the unlocked position, and the latch <NUM> is unlocked. In the unlocked state of the latch <NUM>, the pawl <NUM> remains in the closed state by virtue of the bias of the spring <NUM> applied against the pawl <NUM>. In the latched state, the sensor <NUM> detects the closed state of the pawl <NUM> and communicates the same to the computer controller. The computer controller may, for example, send a warning to the user if it is determined that the trigger <NUM> is unlocked (by virtue of the known position of the actuator <NUM>) while another condition is present (e.g., a motor vehicle to which the latch is attached is being driven).

In <FIG>, the latch <NUM> is shown in an unlocked and unlatched state. To move the latch <NUM> from the latched (i.e., closed) state to the unlatched (i.e., open) state, the user translates the striker away from the latch <NUM> (or vice versa). The striker moves the pawl <NUM> (which is unlocked) in the counterclockwise direction (as viewed in <FIG>) to the open position and against the bias of the spring <NUM>. The pawl <NUM> remains in the open state by virtue of the bias of the spring <NUM> applied against the pawl <NUM>.

In <FIG>, the latch <NUM> is shown in a locked and unlatched state. To lock the latch <NUM>, a user instructs the computer controller to actuate the actuator <NUM>, which causes the piston <NUM> of the actuator <NUM> to extend. Upon extending, the trigger <NUM> is permitted to rotate in the clockwise direction and return to the locked position under the bias of the spring <NUM>. However, while the pawl <NUM> is maintained in the open/unlatched state, the trigger <NUM> remains rotated as shown in <FIG> due to the interference between the pawl <NUM> and the trigger <NUM>. Also, it is noted that the force indirectly applied onto the pawl <NUM> by the spring <NUM> is less than the force indirectly applied onto the pawl <NUM> by the spring <NUM>.

To move the latch <NUM> from the locked and unlatched state of <FIG> to the locked and latched state of <FIG>, the user moves the striker toward the latch <NUM>.

The striker engages the opening in the pawl <NUM>, and the pawl <NUM> rotates in a clockwise direction (as viewed in <FIG>) against the bias of the spring <NUM>. The projection <NUM> of the trigger <NUM> rides on the perimeter of the pawl <NUM> due to the bias of the spring <NUM> until the striker is captivated by the pawl <NUM> in the latched position. And, at which time the projection <NUM> of the trigger <NUM> is seated in the recess <NUM> of the pawl <NUM>, thereby locking the pawl <NUM>. The latch <NUM> is then maintained in the locked and latched state of <FIG>.

It should be understood that the latch <NUM> may be moved between the unlocked states shown in <FIG> without locking the pawl <NUM> using the trigger <NUM>. Also, the user can move the trigger <NUM> between the locked and unlocked states (by way of the computer controller or other device) as desired.

<FIG> depict an embodiment of a latch <NUM> according to the invention. The latch <NUM> is similar to the latch <NUM>, and the primary differences between those latches will be described hereinafter.

In <FIG> and <FIG>, the latch <NUM> is shown interacting with an actuator <NUM> and a release cable <NUM>. The actuator <NUM> is substantially similar to the actuator <NUM>. Upon receiving a command from the computer controller (not shown), the actuator <NUM> is configured to actuate (i.e., extend or retract) a piston <NUM> from the end of actuator <NUM>, and the piston <NUM> is configured to interact with a trigger <NUM> of the latch <NUM> for moving the trigger <NUM> from a locked position to an unlocked position. The release cable <NUM> is also connected to an opening in the trigger <NUM>. In operation, the cable <NUM> may be pulled by either manual or automated means to release the trigger <NUM> (i.e., move the trigger <NUM> from the locked position to the unlocked position). The actuator <NUM> and cable <NUM> may form part of the latch <NUM>, or may form part of a separate assembly. The actuator <NUM> and/or cable <NUM> are omitted in various figures.

Referring now to <FIG>, latch <NUM> generally comprises a rear frame member <NUM> and a front frame member <NUM> (omitted in <FIG> and <FIG>) that are connected together by pins <NUM> and <NUM> and/or other fasteners. A pawl <NUM> has an opening through which the pin <NUM> is positioned, and the pawl <NUM> moves (i.e., rotates) about the pin <NUM> between a closed position (<FIG>) and an open position (<FIG>).

As best shown in <FIG> and <FIG>, a torsion spring <NUM> is mounted around the pin <NUM> and includes a first free end 415a that bears on the rear frame member <NUM> and a second free end 415b that is mounted to in a depression <NUM> formed on the perimeter of the pawl <NUM>. The spring <NUM> biases pawl <NUM> to the open position. A trigger <NUM> has an opening through which the pin <NUM> is positioned, and, like the trigger <NUM>, the trigger <NUM> moves (i.e., rotates) between a locked position and an unlocked position. A torsion spring <NUM> is mounted around the pin <NUM> and includes a first free end 419a that bears on the rear frame member <NUM> and a second free end that is mounted to a bearing surface on the trigger <NUM>. The spring <NUM> biases trigger <NUM> to the locked position.

As shown in <FIG> and <FIG>, a spring member <NUM>, which is formed from a ductile and resilient material, is sandwiched between (i) the frame member <NUM> and (ii) the trigger <NUM> and pawl <NUM>. The spring member <NUM> includes four legs depending therefrom that urge the trigger <NUM> and the pawl <NUM> toward the frame member <NUM>, thereby preventing the trigger <NUM> and pawl <NUM> from rattling during operation. First and second spring arms <NUM> and <NUM> extend from the spring member <NUM>. The first spring arm <NUM> is a flexible curved member that is positioned to interact with a surface of the pawl <NUM>. The second spring arm <NUM> is a flexible curved member that is positioned to interact with a surface of a striker bar <NUM>.

As shown in <FIG>, in the closed position of the pawl <NUM>, the first spring arm <NUM> is seated in a concave recess, indent or depression <NUM> formed on the outer perimeter of the lower side of the pawl <NUM>. The spring arm <NUM> rests above the second free end 415b of the spring <NUM>. The holding force exerted by the spring arm <NUM> onto the pawl <NUM> is greater than the force exerted by the torsion spring <NUM> such that the pawl <NUM> remains in the closed position even after the trigger <NUM> has been moved to the unlocked position. And, in the open position of the pawl <NUM>, the spring arm <NUM> is seated in another concave recess, indent or depression <NUM> formed on the outer perimeter of the lower side of the pawl <NUM>. The force exerted by the spring arm <NUM> onto the pawl <NUM> retains the pawl in the open position. Therefore, like the latch <NUM>, the latch <NUM> also may be considered a bi-stable latch because the latch <NUM> can remain in the open position until it is moved to the closed position and can also remain in the closed position until it is moved to the open position. However, the spring arm <NUM> may be omitted if so desired, and, in such case, the latch <NUM> would not be bi-stable.

The trigger <NUM> includes a tab <NUM> extending from the perimeter of the trigger <NUM>. In the locked position of the trigger <NUM> shown in <FIG>, the tab <NUM> bears on a bearing surface of the frame member <NUM>. Also, in the locked position, a v-shaped recess <NUM> is formed along the perimeter of the trigger <NUM>, and a corresponding v-shaped projection <NUM> formed on the perimeter of the pawl <NUM> is positioned within the recess <NUM>. Engagement between the recess <NUM> and projection <NUM> as well as the tab <NUM> and frame <NUM> prevents the pawl <NUM> from moving in a counterclockwise direction (as viewed in <FIG>) toward the open position.

Referring now to <FIG> and <FIG>, the trigger <NUM> includes a control surface <NUM>, in the form of a vertically extending projection, that is configured to interact with the piston <NUM> of the actuator <NUM>. The piston <NUM> is configured to bear on the bearing surface <NUM> to move the trigger <NUM> from the locked position (<FIG>) to the unlocked position. The control surface <NUM> also has a hole or opening 427a that is connected to the cable <NUM>, as described earlier, for moving the trigger <NUM> from the locked position (<FIG>) to the unlocked position.

Referring now to <FIG>, <FIG>, <FIG>, <FIG>, a striker bar <NUM> is pivotably mounted to an opening <NUM> (<FIG>) in the center of the trigger <NUM> by a pin <NUM>. The pin <NUM> passes through an opening <NUM> in the striker bar <NUM> and the opening <NUM> in the trigger <NUM>. Striker bar <NUM> is directly mounted to the trigger <NUM>. Striker bar <NUM> is configured to rotate with respect to the trigger <NUM> about the pin <NUM>. The perimeter of the striker bar <NUM> includes a concave portion <NUM> that is configured to interact with the striker <NUM>. The striker bar <NUM> is an elongated member having an outer surface and an inner surface. A projection or tab <NUM> projects from the inner surface of the striker bar <NUM>. The tab <NUM> is configured to interact with a wiper arm <NUM> of a switch <NUM>.

The switch <NUM> is connected to a computer controller (not shown) by a cable <NUM> that is terminated at a connector. A cover <NUM> is positioned over the switch <NUM> and at least a portion of the cabling extending therefrom to partially conceal the switch <NUM>. The switch <NUM> may be fixedly connected to the frame member <NUM>. In operation, in an open state of the switch <NUM>, the tab <NUM> of the striker bar <NUM> is not positioned in contact with the wiper arm <NUM> of the switch <NUM>, thereby indicating that (i) the striker <NUM> is not positioned within the interior of the latch <NUM>, and/or (ii) the trigger <NUM> is rotated to the unlocked position. And, in a closed state of the switch <NUM>, the tab <NUM> is positioned in contact with the wiper arm <NUM> of the switch <NUM>, thereby indicating that (i) the striker <NUM> is positioned within the interior of the latch <NUM>, and (ii) the trigger <NUM> is rotated to the locked position.

If, for example, the striker <NUM> were positioned within the interior of the latch <NUM>, and the trigger <NUM> were rotated to the unlocked position, then the tab <NUM> of the striker bar <NUM> would not be positioned in contact with the wiper arm <NUM> of the switch <NUM>, and the switch <NUM> would therefore be in an open state. This occurs because the striker bar <NUM> is mounted to and moves with the trigger <NUM>, and, in the unlocked position of the trigger <NUM>, the travel path of the tab <NUM> of the striker bar <NUM> is radially outward of, and therefore does not intersect, the stationary wiper arm <NUM> of the switch <NUM>. This arrangement of the switch <NUM>, trigger <NUM> and striker bar <NUM> either substantially reduces the potential of or prevents false 'closed' readings while the trigger <NUM> is unlocked.

When the switch <NUM> is closed, it transmits a corresponding 'closed' signal to the computer controller via the cable <NUM>. Other means for sensing the presence or absence of the striker bar <NUM> are known to those skilled in the art, such as magnetic sensors, proximity sensors, Hall-Effect sensor and optical sensors. Thus, the switch <NUM> may be more generally referred to as a means for sensing a position, presence or absence of striker bar <NUM>.

As is best shown in <FIG>, the second spring arm <NUM> of the spring member <NUM> is positioned to bear on the perimeter surface of the striker bar <NUM>. The second spring arm <NUM> is configured to bias the striker bar <NUM> in the direction of the striker <NUM>. And, moving the striker <NUM> into the latch <NUM> causes the striker bar <NUM> to rotate with respect to the trigger <NUM> against the bias of the spring arm <NUM>. As shown in <FIG>, rotation of the striker bar <NUM> in the counterclockwise direction is limited by the spring arm <NUM>, and rotation of the striker bar <NUM> in the clockwise direction is limited by the pin <NUM>.

It should be understood that the first and second spring arms may be replaced by simple spring elements, and that the first and second spring arms are not required to be associated with the same spring component. Thus, the first and second spring arms may be referred to more generally as spring elements herein.

Turning now to <FIG>, <FIG>, <FIG> and <FIG>, the rear frame member <NUM> includes a bent tab section <NUM> having an L-shape that extends inwardly toward the interior of the frame. The bent tab section <NUM> is positioned adjacent and extends from the concave opening <NUM> in the rear frame member <NUM> that is provided for accommodating the striker <NUM>. The free end of the bent tab section <NUM> extends upwardly toward the striker <NUM>. The bent tab section <NUM> is formed integrally with the frame member <NUM>. The bent tab section <NUM> is arranged between the pins <NUM> and <NUM> as viewed in a longitudinal direction. The bent tab section <NUM> may be referred to herein more generally as a projection.

A bumper <NUM> is mounted on the bent tab section <NUM>. The bumper <NUM> may be composed of an elastomeric material such as rubber, for example. The top end of the bumper <NUM> includes a concave surface <NUM> that is configured to interact with the cylindrical body of the striker <NUM>. In operation, the striker <NUM> contacts the concave surface <NUM> without producing an audible bump, squeak or rattle. The bottom end of the bumper <NUM> includes an opening <NUM> for receiving the free end of the bent tab section <NUM>. The bumper <NUM> may be connected to the bent tab section <NUM> using adhesive, for example. Two elongated arms <NUM> are positioned on opposite sides of the opening <NUM>. In an assembled form of the latch <NUM>, the arms <NUM> are positioned in the channels that run adjacent the bent tab section <NUM>, as best shown in <FIG>. An exterior surface of the bumper <NUM> is maintained flush with an exterior surface of the frame member <NUM> and extends within an interior region of the frame formed by frame members <NUM> and <NUM>. An opening <NUM>, in the form of a rectangular aperture, extends across the width of the bumper <NUM> (i.e., in the longitudinal direction), and intersects the opening <NUM>. The opening <NUM> receives barbs <NUM> (<FIG>) on the bent tab section <NUM> for holding the bumper <NUM> to the frame.

Turning now to the operation of the latch <NUM> shown in <FIG>, in <FIG>, the latch <NUM> is shown in a locked and latched state. In the locked and latched (i.e., closed) state, the latch <NUM> retains the striker <NUM> within the pawl <NUM>. And the pawl <NUM> is held in a fixed rotational position by the trigger <NUM> due to the interface between the surfaces <NUM> and <NUM> (see <FIG>). The switch <NUM> is maintained in a closed position, thereby indicating that (i) the striker <NUM> is positioned within the interior of the latch <NUM>, and (ii) the trigger <NUM> is rotated to the locked position.

In <FIG>, the latch <NUM> is shown in an unlocked and unlatched state. To move the latch <NUM> from the latched (i.e., closed) state to the unlatched (i.e., open) state, the computer controller actuates the actuator <NUM>, which causes the piston <NUM> of the actuator <NUM> to extend and bear on the control surface <NUM> of the trigger <NUM>, which causes the trigger <NUM> to rotate in a counterclockwise direction (as viewed in <FIG>) and against the bias of the spring <NUM>. Rotation of the trigger <NUM> may result in slight rotation of the pawl <NUM> until the recess <NUM> of the trigger separates from the projection <NUM> of the pawl <NUM>. Alternatively, in lieu of activating the actuator <NUM>, translating the release cable <NUM> (either manually or by an actuator) would also result in counterclockwise rotation of the trigger <NUM>.

Once the recess <NUM> of the trigger separates from the projection <NUM> of the pawl <NUM>, the trigger <NUM> is maintained in the unlocked position, and the latch <NUM> is unlocked. In the unlocked state of the latch <NUM>, the pawl <NUM> remains in the closed state by virtue of the engagement between the spring arm <NUM> and the pawl <NUM>. If, however, the spring arm <NUM> were omitted, then the pawl <NUM> would automatically move to the open state by virtue of the spring <NUM>.

The user then translates the striker <NUM> away from the latch <NUM>. The striker <NUM> moves the pawl <NUM> (which is unlocked) in the counterclockwise direction (as viewed in <FIG>) against the bias of the spring arm <NUM>. As the pawl <NUM> rotates, the spring arm <NUM> slides along the surface of the pawl <NUM>. The pawl <NUM> eventually releases the striker <NUM> as the striker <NUM> is moved away from the latch <NUM>. At the same time, the striker <NUM> separates from the striker bar <NUM>, and, in the absence of the striker <NUM>, the second spring arm <NUM> urges the striker bar <NUM> to rotate in the clockwise direction. Consequently, the tab <NUM> of the striker bar <NUM> separates from the wiper arm <NUM> of the switch <NUM>, thereby indicating that (i) the striker <NUM> is not positioned within the interior of the latch <NUM>, and/or (ii) the trigger <NUM> is rotated to the unlocked position. The computer controller identifies this change in state due to the signals (or absence of signals) transmitted from switch <NUM>.

The pawl <NUM> remains in the open state by virtue of the engagement between the spring arm <NUM> and the pawl <NUM> as well as the force exerted by the spring <NUM>. At this stage, the trigger <NUM> remains in the unlocked state due to the engagement between the piston <NUM> and the control surface <NUM> of the trigger <NUM>.

To return the trigger <NUM> to the locked position, the computer controller actuates the actuator <NUM>, which causes the piston <NUM> of the actuator <NUM> to retract and separate from the control surface <NUM> of the trigger <NUM>. The torsion spring <NUM> then returns the trigger <NUM> to its locked position. At this stage, the pawl <NUM> remains open due to the bearing force of the spring arm <NUM>.

To return the latch <NUM> to the locked and latched state of <FIG>, the user moves the striker <NUM> toward the latch <NUM>. The striker <NUM> engages the concave opening in the pawl <NUM>, and the pawl <NUM> rotates in a clockwise direction against the bias of the spring <NUM>. The projection <NUM> of the pawl <NUM> rides on the perimeter of the trigger <NUM> (and causes slight rotation of the trigger <NUM> against the bias of the spring <NUM>) until the striker <NUM> bears on the bumper <NUM>. And, at which time the projection <NUM> of the pawl <NUM> is seated in the recess <NUM> of the trigger <NUM>. The latch <NUM> is then maintained in the locked and latched state of <FIG>. The tab <NUM> of the striker bar <NUM> contacts the wiper arm <NUM> of the switch <NUM>, thereby indicating that (i) the striker <NUM> is positioned within the interior of the latch <NUM>, and (ii) the trigger <NUM> is rotated to the locked position.

It is noted that the various features described in the separate embodiments may be combined or substituted.

Claim 1:
A latch assembly comprising:
a frame;
a pawl (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) including a surface (<NUM>) for receiving a striker (<NUM>, <NUM>) and being movably coupled to the frame between an open and a closed position, wherein, in the closed position, the pawl (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) is positioned to retain the striker (<NUM>, <NUM>) to the latch assembly, and, in the open position, the pawl (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) is not positioned to retain the striker (<NUM>, <NUM>) to the latch assembly;
a trigger (<NUM>, <NUM>, <NUM>) that is mounted to the frame and is movable between a locked position and an unlocked position, wherein, in the locked position of the trigger (<NUM>, <NUM>, <NUM>), the trigger (<NUM>, <NUM>, <NUM>) is positioned to retain the pawl (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) in the closed position;
a striker bar (<NUM>) that is movably coupled to the trigger (<NUM>, <NUM>, <NUM>) and is positioned to be contacted by the striker (<NUM>, <NUM>), wherein the striker bar (<NUM>) is configured to move in the course of moving the striker (<NUM>, <NUM>) into the pawl (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>); and
means for sensing a position of the striker bar (<NUM>), wherein the position of the striker bar (<NUM>) is indicative of the position of the striker (<NUM>, <NUM>) and the position of the trigger (<NUM>, <NUM>, <NUM>).