Patent Description:
As is described in <CIT>, compression latches for mounting on doors or panels are known. Compression latches are used in applications in which it is desirable to both latch a door or panel to the frame in which it is mounted and to seal the edge of the panel to the frame when closed. For example, compression latches are desirable when the opening in which the panel is mounted is provided with a gasket that must be compressed to provide a seal. Compression latches may be used on doors for heating, ventilation and air conditioning (HVAC) units, for example. HVAC unit doors, which are typically thick and filled with insulation, can have wide thickness tolerances. It would be desirable to provide a modular compression latch that compensates for the thickness tolerance.

<CIT> illustrates for example a rotary latch includes a fascia in the form of a pan, handle connected to a shank defining a longitudinal axis and extending through an aperture in the housing, and a latch arm arranged to rotate about the longitudinal axis as the shank is turned by the handle. A centre bar is mounted behind the housing and oriented perpendicular to the longitudinal axis. The centre bar defines at least one cam follower, A rotatable actuator (rotator) defining a cam surface, and biasing means for biasing the cam follower against the cam surface are also provided. The latch arm is arranged to rotate about the longitudinal axis with the rotator while the distance of the latch arm from the centre bar is fixed and its distance from the housing is controlled by the rotation of the centre bar.

<CIT> relates to a bolt turning in the threaded sleeve has operating surfaces at one end, and a locking bar at the other end, gripping behind a fixed component. The bolt is axially movable by a guide groove in the threaded sleeve for clamping the locking-bar behind the fixed component. A transverse pin in the bolt fits into the guide-groove. A sleeve-shaped connecting-link component between the threaded sleeve and the bolt has a guide groove joined to the threaded sleeve. The bolt's operating surfaces adjoins a flange which has an annular seal in a peripheral groove sealing the annular space between an inner peripheral surface of the threaded sleeve and the flange's outer peripheral surface.

The invention is defined in the independent claim. Further advantageous embodiments are defined in the dependent claims. According to the present invention, a compression latch for a door is provided. The latch includes a driver that is rotatable with respect to the door between an unlocked position and a locked position. The driver is configured to be mounted to one side of the door. A driver shaft is non-rotatably connected to the driver such that the driver shaft rotates along with the driver. A pawl assembly comprises (i) a housing that is configured to be fixedly mounted to the door, and (ii) a pawl that is movably connected to the housing and is configured to both rotate and translate with respect to the housing in response to rotation of the driver shaft, In an unlocked position of the driver, the pawl is positioned to permit opening of the door, and, in a locked position of the driver, the pawl is positioned to prevent opening of the door. The compression latch is configured to translate the pawl closer toward the door upon rotating the driver from the unlocked position to the locked position. The driver shaft includes a proximal end that is non-rotatably connected to the driver, and a distal end that is non-rotatably connected to said pawl. The pawl is fixedly connected to a shaft of the pawl assembly, and the shaft of the pawl assembly is non-rotatably connected to the driver shaft. The shaft of the pawl assembly includes a threaded shaft that is configured to be connected to the pawl, and a sleeve that is non-rotatably connected to the threaded shaft as well as the driver shaft.

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.

More particularly, <FIG> are partial side-elevation views of the driver of <FIG> shown in an unlocked state. <FIG> are cross-sectional views of the driver of <FIG> taken along the lines 14D-14D and 14E-14E, respectively. <FIG> is a detailed view of <FIG>.

<FIG> are partial side-elevation views of the driver of <FIG> shown in a locked state. <FIG> are cross-sectional views of the driver of <FIG> taken along the lines 14I-14I and 14J-14J, respectively. <FIG> is a detailed view of <FIG>.

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" are herein used throughout this disclosure as relative terms. In the context of describing the latch, the term "proximal," such as in the phrase "proximal end", is herein intended to mean toward or closer to a driver <NUM> of the latch, whereas the term "distal," such as in the phrase "distal end" is herein intended to mean away from or further away from driver <NUM> of the latch.

<FIG> depict a compression latch assembly <NUM> (latch <NUM>, hereinafter) that is mounted to a door <NUM>. <FIG> depict the latch <NUM> in an unlocked state, <FIG> depict the latch <NUM> in a partially locked state, and <FIG> depict the latch <NUM> in a locked and compressed state.

Latch <NUM> generally comprises a driver sub-assembly <NUM> that is connected to a pawl sub-assembly <NUM> for maintaining a door <NUM> in either locked or unlocked state with respect to a frame to which door <NUM> is movably mounted. Door <NUM> includes a front side 12a, a rear side 12b, and a hollow area positioned between those sides, which may be filled with foam, for example. Door <NUM> may vary from that which is shown and described.

Referring now the features of driver sub-assembly <NUM>, driver sub-assembly <NUM> generally comprises a driver <NUM> that is (i) rotatably mounted to a cylindrical bezel <NUM> about longitudinal axis A, and (ii) non-rotatably connected to a driver shaft <NUM>.

Driver <NUM> is shown in <FIG>. Driver <NUM> is an L-shaped member that includes an elongated portion having a gripping surface <NUM> for grasping by an end user. Driver <NUM> is rotatably mounted to bezel <NUM> about longitudinal axis A, however, it should be understood that driver <NUM> is prevented from translating along axis. Driver <NUM> may be provided in the form of a handle, a knob, a lever, a 'T', or a tool driver, for example.

A lock plug <NUM> is mounted within an opening on the front face of driver <NUM>. Lock plug <NUM>, which has a recess for receiving a key or other tool, is configured to selectively permit rotation of driver <NUM>, as is known in the art. Lock plug <NUM> is an optional component of driver <NUM>.

In a locked configuration of lock plug <NUM>, rotation of driver <NUM> is not possible. And, in an unlocked configuration of lock plug <NUM>, rotation of driver <NUM> is possible. More particularly, as shown in <FIG> and <FIG>, when the proper key is inserted into the lock plug <NUM>, the user can rotate the lock plug <NUM>. A cam or ramp <NUM> on the underside of the lock plug <NUM> rotates therewith and interacts with a post <NUM> that is loaded by a spring <NUM>. Post <NUM> is translatably positioned with a recess <NUM> formed in the underside of driver <NUM>.

In the locked position of lock plug <NUM> (shown in <FIG>), a bearing surface of ramp <NUM> bears on the proximal end 44a of post <NUM> and moves post <NUM> in the direction shown by the arrow in <FIG> against the bias of spring <NUM>. And, the distal end 44b of post <NUM> is positioned within opening <NUM> (<FIG>) of stationary bezel <NUM>. When distal end 44b of post <NUM> is positioned within opening <NUM> of stationary bezel <NUM> it is not possible to rotate driver with respect to bezel <NUM>.

In the unlocked position of lock plug <NUM> (not shown), an opening in ramp <NUM> is rotationally aligned with post <NUM> such that ramp <NUM> does not bear on the proximal end 44a of post <NUM>. Thus, spring <NUM> is permitted to move post <NUM> in an upward direction such that distal end 44b of post <NUM> does not protrude from the lower side of driver <NUM>. Accordingly, post <NUM> is not positioned within opening <NUM> of stationary bezel <NUM>. When distal end 44b of post <NUM> is not positioned within opening <NUM> of stationary bezel <NUM> it is possible to rotate driver with respect to bezel <NUM> (as well as door <NUM>).

A cover <NUM> is mounted to the front face of driver <NUM> to conceal the head of fastener <NUM> in an effort to prevent unauthorized removal of the fastener <NUM>. Cover <NUM> includes an opening <NUM> to provide access to the front face of lock plug <NUM>. As will be described with reference to <FIG>, the lock plug <NUM> and cover <NUM> are specially configured to prevent removal of the cover <NUM>, as well as the underlying fastener <NUM>, in a locked state of the lock plug <NUM>. In an unlocked state of the lock plug <NUM>, the cover <NUM>, as well as the underlying fastener <NUM>, may be removed/disassembled from the driver <NUM>.

Turning now to <FIG>, the cover <NUM> includes a protrusion <NUM> on its interior facing surface that is positioned to extend through the opening <NUM> in the driver <NUM>. A relief <NUM> is formed in the bottom side of the protrusion <NUM>. The relief <NUM> may also be referred to herein as a cutout, gap, slot, opening, surface or recess.

A cam lock <NUM> is non-rotatably mounted to the body of the lock plug <NUM> such that the cam lock <NUM> rotates along with the lock plug <NUM>. The cam lock <NUM> is situated behind a shoulder formed on the front face of the lock plug <NUM> such that, in an assembled configuration of the driver <NUM>, the cam lock <NUM> is not visible to an end user. The cam-lock <NUM> is (optionally) a metallic member having a uniform thickness (as viewed in <FIG>), a tear drop shaped perimeter (more generally, non-circular perimeter), and an opening formed in the center of the tear drop shape through which the lock plug <NUM> is mounted. The rounded perimeter portion of the tear drop shaped perimeter extends further from the axis of rotation of the cam lock <NUM> than does the flat perimeter portion 41a of the tear drop shaped perimeter.

In operation of the lock plug <NUM>, the cam lock <NUM> is positioned to selectively enter the relief <NUM> of the cover <NUM>. More particularly, in a locked state of the lock plug <NUM> shown in <FIG>, the lock plug <NUM> is rotated to a position such that the cam lock <NUM> is positioned within the relief <NUM>. In particular, in the locked state, the rounded perimeter portion of the tear drop shaped perimeter is positioned within the relief <NUM>. And, in an unlocked state of the lock plug <NUM> shown in <FIG>, the lock plug <NUM> is rotated to a position such that the cam lock <NUM> is not positioned within the relief <NUM>. In particular, in the unlocked state, the flat perimeter portion 41a of the tear drop shaped perimeter is rotationally aligned with but radially spaced apart and separated from the relief <NUM>.

In the locked state of the lock plug <NUM>, it is not possible to remove the cover <NUM> (and access the fastener <NUM>) because the cover <NUM> is captivated to the driver <NUM> by the cam lock <NUM>. And, in the unlocked state of the lock plug <NUM>, it is possible to remove the cover <NUM> (and access the fastener <NUM>) because the cover <NUM> is not captivated to the driver <NUM> by the cam lock <NUM>.

Those skilled in the art will recognize that the cam lock <NUM> is not limited to that which is shown in the figures. For example, the cam lock <NUM> may be a protrusion that projects radially from the lock plug <NUM> for selectively interacting with the relief <NUM>. The cam lock <NUM> may be referred to herein as a projection. The projection may be either integral with or separate from the lock plug <NUM>.

Bezel <NUM> is shown in <FIG>. Bezel <NUM> is fixedly mounted to a front side 12a of door <NUM> by two self-tapping fasteners <NUM> that are capable of piercing door <NUM>. Each fastener <NUM> is positioned through a respective hole <NUM> formed in bezel <NUM>. It should be understood that fasteners <NUM> as well as any holes for receiving fasteners <NUM> can vary, as is known in the art. An alignment projection <NUM> <FIG>) on the underside of bezel <NUM> engages with a hole <NUM> in door <NUM> to key the rotational position of bezel <NUM> on door <NUM> and also prevent rotation of bezel <NUM> as driver <NUM> moves between the locked and unlocked states. Opening <NUM> is formed on the front face of bezel <NUM> and is configured to interact with a driver locking feature, as was described above.

Driver shaft <NUM> is rotatably mounted to bezel <NUM> and is non-rotatably mounted to driver <NUM>. Driver shaft <NUM> is also shown in <FIG>. The term "non-rotatable" means, for example, that driver shaft <NUM> is not rotatable with respect to driver <NUM>, however, driver <NUM> and driver shaft <NUM> can simultaneously rotate in the same direction. A non-circular head portion <NUM> (i.e., having opposing flat portions <NUM>) is provided at the proximal end of the driver shaft <NUM>. Head portion <NUM> is non-rotatably positioned within a non-circular recess <NUM> (<FIG>) formed in the rear side of driver <NUM>. A cylindrical shaft portion <NUM> of driver shaft <NUM> is rotatably positioned within a central hole <NUM> (<FIG>) of bezel <NUM> such that driver shaft <NUM> can rotate within bezel <NUM>. The non-circular connector <NUM> at the distal end of driver shaft <NUM> is configured to pass through an opening <NUM> in door <NUM> and engage with the pawl subassembly <NUM>, as will be explained in greater detail with respect to pawl subassembly <NUM>. The non-circular connector <NUM> of driver shaft <NUM> is cylindrical and has two flat portions <NUM>, as viewed in cross-section, for keying driver shaft <NUM> to pawl subassembly <NUM>. A threaded fastener <NUM> is positioned through an opening <NUM> in the front face of driver <NUM> and is configured to be mounted to a threaded opening <NUM> formed within head portion <NUM> of driver shaft <NUM>. Fastener <NUM> fixedly mounts driver <NUM> to shaft <NUM>; and, driver <NUM> and driver shaft <NUM> are held non-rotatable due to the keyed interface between non-circular head portion <NUM> and non-circular recess <NUM>.

Referring now to pawl sub-assembly <NUM> of latch <NUM>, which is shown on the right hand side of door <NUM> in <FIG> and in <FIG>, pawl sub-assembly <NUM> includes a hollow cylindrical housing <NUM> that is fixedly and non-rotatably mounted to the rear side 12b of door <NUM> by fasteners <NUM>. Housing <NUM> is shown in <FIG>. Housing <NUM> remains stationary during operation of latch <NUM>. Specifically, housing <NUM> has shoulders or flanges <NUM> at its proximal end (i.e., door mounting end), and the shoulders or flanges <NUM> include holes <NUM> through which the fasteners <NUM> are positioned. Like fasteners <NUM>, fasteners <NUM> may be self-tapping screws that are capable of piercing holes in door <NUM>. Fasteners <NUM> can vary. A central hole <NUM> oriented with axis A is defined in the proximal end. In an assembled form of latch <NUM>, connector <NUM> of driver shaft <NUM> is positioned through hole <NUM> of housing <NUM>.

Two opposing ramps 66a and 66b (referred to either individually or collectively as ramp(s) <NUM>) are positioned on opposite sides of the revolved side wall of housing <NUM>. Ramps <NUM> are symmetrical (and mirror images) and spaced apart in a circumferential direction by <NUM> degrees. Each ramp <NUM> extends in a circumferential direction about the axis A. Each ramp <NUM> includes a proximal portion 67a, a distal portion 67b, and an intermediate portion 67c defined between portions 67a and 67b. As viewed in an axial direction, proximal portion 67a extends in the proximal direction (as compared to portions 67b and 67c). Portion 67c is a detent that is provided for pressure-reduction purposes, as will be described in greater detail later.

Each ramp <NUM> may pass through either all or a portion of the wall thickness of housing <NUM>. Alternatively, each ramp <NUM> could be provided in the form of a projection. Ramps <NUM> may also be referred to as slots, guides or cams. Ramps <NUM> are sized to accommodate pins 70a and 70b (referred to either individually or collectively as pin(s) <NUM>) in a form-fitting manner, as will be described in greater detail later.

A sleeve <NUM> in the form of a hollow cylindrical body is positioned within the hollow interior of housing <NUM>. Sleeve <NUM> is depicted in <FIG>. A non-circular hole <NUM> is defined on the proximal end face of sleeve <NUM>. Hole <NUM> is sized to accommodate connector <NUM> of driver shaft <NUM>. Hole <NUM> and connector <NUM> are keyed to each other such that driver shaft <NUM> is non-rotatable with respect to sleeve <NUM>. In other words, sleeve <NUM> rotates with driver shaft <NUM>. A large diameter circular hole <NUM> is defined on the distal end face of sleeve <NUM>. A circular head <NUM> of threaded shaft <NUM> is configured to be positioned within hole <NUM>. Holes <NUM> and <NUM> are co-aligned with axis A. Holes 78a and 78b (referred to either individually or collectively as hole(s) <NUM>) are defined transversely through sleeve <NUM> and intersect hole <NUM>. Holes <NUM> are disposed <NUM> degrees apart about axis A. Pins 70a and 70b are friction or interference fit into holes 78a and 78b, respectively.

Threaded shaft <NUM> includes an elongated body having a circular and hollow head <NUM> at its proximal end, and a non-circular threaded distal end <NUM>. Shaft <NUM> is also depicted in <FIG>. The non-circular threaded distal end <NUM> includes opposing flat portions <NUM>. A circular blind hole <NUM> is formed in head <NUM> and is sized for receiving connector end <NUM> of driver shaft <NUM>, as is shown in <FIG>. Holes 88a and 88b (referred to either individually or collectively as hole(s) <NUM>) are defined transversely through head <NUM> and intersect hole <NUM>. Holes <NUM> are disposed <NUM> degrees apart about axis A. Pins 70a and 70b are friction or interference fit into holes 88a and 88b, respectively, thereby captivating shaft <NUM> to sleeve <NUM>. Shaft <NUM> and sleeve <NUM> may be combined into a single unitary component. To that end, shaft <NUM> and sleeve <NUM> may be referred to herein more generally as a shaft.

In summary, and as best depicted in <FIG>, pins 70a and 70b are positioned through holes 78a and 78b of sleeve <NUM> as well as holes 88a and 88b of shaft <NUM>, respectively, thereby non-rotatably connecting shaft <NUM> and sleeve <NUM>. Also, as noted above, sleeve <NUM> is non-rotatably connected to driver shaft <NUM>, and driver shaft <NUM> is non-rotatably connected to driver <NUM>. Accordingly, rotation of driver <NUM> results in rotation of threaded shaft <NUM> with respect to the stationary housing <NUM>. The radially outward portion of pins 70a and 70b are positioned and travel within ramps 66a and 66b, respectively, of stationary housing <NUM>.

It is conceivable that pins <NUM> could be mounted to the interior surface of housing <NUM>, and ramps 66a and 66b could be disposed on sleeve <NUM> (assuming that shaft <NUM> and sleeve <NUM> are fixed together).

Referring now to <FIG>, door <NUM> may be a door for an HVAC unit, as noted above. HVAC unit doors, which are typically thick and filled with insulation, can have wide thickness tolerances. To accommodate for the thickness tolerance of the width D2 of door <NUM>, a longitudinal gap having a dimension D1 is provided between the distal tip 28a of driver shaft <NUM> and the distal surface 86a of blind hole <NUM> (i.e., in an assembled form of latch <NUM>). So long as driver shaft <NUM> remains rotationally keyed (i.e., non-rotatable) with sleeve <NUM>, dimension D1 can vary without affecting operation of latch <NUM>. For example, if door <NUM> were slightly wider than that which is shown, dimension D1 would be greater than that shown in <FIG>, however, driver shaft <NUM> would be rotationally keyed with sleeve <NUM> and operate as intended. Conversely, if door <NUM> were slightly narrower than that which is shown, dimension D1 would be less, however, driver shaft <NUM> would be rotationally keyed with sleeve <NUM> and latch <NUM> operate as intended. Thus, latch <NUM> can be considered modular because it compensates for the thickness tolerance of the door <NUM>. Also, the length of driver shaft <NUM> may vary from that which is shown in order to accommodate door thicknesses outside of the above-described thickness tolerance.

Referring now to <FIG> and <FIG>, a pawl <NUM> is mounted to threaded distal end <NUM> of shaft <NUM> by two nuts <NUM>. Pawl <NUM> includes an L-shaped bracket <NUM>, and a roller cam <NUM> mounted to bracket <NUM> by a fastener <NUM>. As is known in the art, roller cam <NUM> is configured to interact with a frame (not shown) to which door <NUM> is movably attached. In the closed and locked state of latch <NUM> shown in <FIG>, roller cam <NUM> as well as door <NUM> is compressed against the frame. And, in the unlocked state of latch <NUM> shown in <FIG>, roller cam <NUM> is detached from the frame.

Pawl <NUM>, sleeve <NUM>, shaft <NUM>, pins <NUM> and roller cam <NUM> may together be considered as a pawl assembly or, more generally, as a pawl.

According to one method of operating latch <NUM>, starting from <FIG>, latch <NUM> is initially positioned in an unlocked state, for example. Lock plug <NUM> in in an unlocked state. In the unlocked state, driver <NUM> is rotated to a position where pawl <NUM> and its roller cam <NUM> do not register or interfere with the frame (not shown) such that door <NUM> can be moved to an open position with respect to the frame. In the unlocked state, pins <NUM> are positioned within distal portions 67b of respective ramps <NUM>. When pins <NUM> are positioned within distal portions 67b of respective ramps <NUM>, pawl <NUM> and its roller cam <NUM> are positioned far from the rear side 12b of door <NUM> such that a gap or distance C1 (<FIG>) is defined between the proximal side of roller cam <NUM> and the rear side 12b of door <NUM>. Stated differently, at distance C1, pawl <NUM> is not compressed against the frame to which the door <NUM> is connected.

A user then moves latch <NUM> from the unlocked state to the partially unlocked/locked state shown in <FIG>. In the partially unlocked/locked state, driver <NUM> is rotated toward the locked state to a position where pawl <NUM> and its roller cam <NUM> register or interfere with the frame (not shown) such that door <NUM> cannot be moved to a fully open position. The door <NUM> can, however, be moved by distance C1 toward the open position until the proximal side of roller cam <NUM> contacts the frame.

Upon rotating driver <NUM> from the unlocked state to the partially unlocked/locked state shown in <FIG>, driver shaft <NUM>, pins <NUM>, sleeve <NUM> and pawl <NUM> rotate simultaneously along with driver <NUM> (due to the above-described non-rotatable connections) with respect to the stationary housing <NUM>. As driver <NUM> is rotated, pins <NUM> slide within their respective ramps <NUM>. Specifically, pins <NUM> slide from distal portions 67b to intermediate portions 67c. At this stage, rotation of driver does not yet cause translation of pawl <NUM> along axis A and toward rear side 12b of door <NUM>. Thus, in the partially unlocked/locked state shown in <FIG>, the distance C1 is defined between the proximal side of roller cam <NUM> and the rear side 12b of door <NUM>, and pawl <NUM> is not compressed against the frame to which the door <NUM> is connected.

The user continues to rotate driver <NUM> in the same rotational direction to the locked state shown in <FIG>. Specifically, as driver <NUM> is rotated further, pins <NUM> slide from intermediate portions 67c to proximal portions 67a of their respective ramps <NUM>. Moving pins <NUM> through proximal portions 67a causes pawl <NUM> to simultaneously rotate and translate toward rear side 12b of door <NUM>. Specifically, the geometry of proximal portions 67a (which extend along the axis A in the proximal direction), as well as the pinned interface between housing <NUM>, sleeve <NUM> and shaft <NUM>, forces sleeve <NUM> and shaft <NUM> to move in a proximal direction toward rear side 12b of door <NUM>. Once the pins <NUM> reach the terminal end of proximal portions 67a, latch <NUM> is maintained in a fully-compressed and locked state. At this stage, roller cam <NUM> registers with the door frame to prevent door <NUM> from being opened. Also, the distance C2 between the proximal side of roller cam <NUM> and the rear side 12b of door <NUM> may be zero, or, more generally, less than the distance C1. Stated differently, at distance C2, pawl <NUM> is compressed against the frame. In a fully-compressed state of the latch <NUM>, any seal at the interface between door <NUM> and its frame (not shown) is also fully compressed.

If the user then rotates driver <NUM> in the opposite rotational direction (unlock direction) from the locked state shown in <FIG> to the partially unlocked/locked state shown in <FIG>, pins <NUM> move from proximal portions 67a to intermediate portions 67c of ramps <NUM>. Consequently, pawl <NUM> rotates toward (but not too) the unlocked state and pawl <NUM> also translates in the distal direction (due to the geometry of proximal portions 67a). At this stage, the distance C1 is defined between the proximal side of roller cam <NUM> and the rear side 12b of door <NUM>.

A detent or stop feature is defined at intermediate portions 67c signaling to the user (via tactile feel) that door <NUM> is partially unlocked at this stage and the compartment to which door <NUM> is attached may be de-pressurizing. The user may stop rotating driver <NUM> at this point. More particularly, if the compartment to which door <NUM> is attached is pressurized, then moving driver <NUM> to the partially unlocked/locked state shown in <FIG> will depressurize the compartment while preventing door <NUM> from suddenly moving to the fully open position as a result of the depressurization. Specifically, pawl <NUM> would contact the door frame of the compartment and prevent the door from fully opening while allowing door <NUM> to open by a limited distance (i.e., distance C1) for depressurization purposes. In the absence of intermediate portions 67c, unlocking latch <NUM> could result in door <NUM> rapidly and unexpectedly opening due to depressurization of the compartment.

The user then continues to rotate driver <NUM> in the opposite rotational direction (i.e., the unlock direction) from the partially unlocked/locked state shown in <FIG> to the unlocked state of <FIG>. Continuing to rotate driver <NUM> in the opposite rotational direction causes pins <NUM> to move from intermediate portions 67c to distal portions 67b of ramps <NUM>. Consequently, pawl <NUM> rotates to the unlocked state shown in <FIG>, but pawl <NUM> does not translate along axis A any further from its position shown in <FIG>. Thus, the distance C1 is defined between the proximal side of roller cam <NUM> and the rear side 12b of door <NUM>. The latch <NUM> is again in an unlocked state.

<FIG> depict a multi-point latch <NUM> for securing door <NUM>. Multi-point latch <NUM> comprises latch <NUM> (the same latch as described above) and two separate pawl sub-assemblies 33a and 33b. Pawl sub-assemblies 33a and 33b are connected to latch <NUM> by way of a linkage <NUM>. Linkage <NUM> interconnects latch <NUM> to pawl sub-assemblies 33a and 33b such that pawl sub-assemblies 33a and 33b move synchronously with pawl sub-assembly <NUM> of latch <NUM>. Accordingly, rotating latch <NUM> to the locked state causes pawl sub-assemblies 33a and 33b to also move to the locked state. And, rotating latch <NUM> to the unlocked state causes pawl sub-assemblies 33a and 33b to move to the unlocked state.

It should be understood that pawl sub-assemblies 33a and 33b are mounted to door <NUM> in the same manner as pawl sub-assembly <NUM> of latch <NUM>. Pawl sub-assemblies 33a and 33b are not directly connected to a driver sub-assembly <NUM>. Instead, pawl sub-assemblies 33a and 33b are indirectly connected to driver sub-assembly <NUM> of latch <NUM> via linkage <NUM>. It can be appreciated that pawl sub-assembly <NUM> may be used independently and without driver sub-assembly <NUM> directly mounted thereto.

Pawl sub-assemblies 33a and 33b are structurally and functionally equivalent to pawl sub-assembly <NUM> of latch <NUM>, thus, pawl sub-assemblies <NUM> are a modular feature of latch <NUM> that can be used together to perform a latching operation.

<FIG> depict one mounting point on the top portion of linkage <NUM> of multi-point latch <NUM>. Linkage <NUM> comprises a rod <NUM> having a groove <NUM> formed therein and a series of holes defined through the thickness of rod <NUM> that intersect groove <NUM>. A hole <NUM> and an elongated slot <NUM> are formed through rod <NUM>. An L-shaped clip <NUM> is positioned at the top end of groove <NUM>. Clip <NUM> includes a first hole <NUM> for receiving a pin <NUM> extending from a cam 114a and a second hole or slot <NUM> through which a fastener <NUM> passes through for mounting to a threaded hole <NUM> in rod <NUM>. Groove <NUM> and fastener <NUM> together prevent clip <NUM> from rotating or translating with respect to rod <NUM>.

Cam 114a includes a pin <NUM>, as described above, as well as a non-circular hole <NUM> having two opposing flat portions <NUM>. An axis of rotation B of cam 144a passes through hole <NUM>. Hole <NUM> is configured to receive non-circular threaded distal end <NUM> of shaft <NUM> in a tight form fitting manner. One or more fasteners <NUM>, such as hex nuts, are employed to fixedly connect cam 114a to threaded distal end <NUM>. By virtue of the non-circular connection between cam 114a and shaft <NUM>, those components are non-rotatable with respect to each other (i.e., they rotate together). Pin <NUM> is positioned through slot <NUM> and hole <NUM> and is connected to a clip <NUM>. Clip <NUM> connects the free end of pin <NUM> to L-shaped clip <NUM> and prevents the free end of pin <NUM> from disengaging from clip <NUM>. Cam 114a can rotate with respect to rod <NUM>.

Cam 114a is mounted to shaft <NUM> that is associated with pawl sub-assembly 33a. A second cam 114b is mounted to the bottom end of rod <NUM> using a clip <NUM> in the same manner as cam 114a. Cam 114b is mounted to shaft <NUM> that is associated with pawl sub-assembly 33b. A third cam 114c is mounted to the longitudinal center of rod <NUM> in the same manner as cams 114a and 114b. Cam 114c is mounted to shaft <NUM> that is associated with pawl sub-assembly <NUM> of latch <NUM>. Cams 114a-114c are structurally and functionally equivalent and operate in the same manner.

Hole <NUM> and elongated slot <NUM> are associated with cam 114a, and, although not shown, it should be understood that, another hole <NUM> and slot <NUM> are associated with cam 114b, and yet another hole <NUM> and slot <NUM> are associated with cam 114c. Elongated slots <NUM> and <NUM> together accommodate for variances in the vertical length and position of the various components of linkage <NUM> as well as the pawl sub-assemblies <NUM> to which linkage <NUM> is connected. While it is possible, it is not intended to have a vertical adjustment at cam 114c, which is the driving location, because there exists a tight diametrical fit between the rod <NUM> and pin <NUM> at cam 114c. Adjustment due to tolerance issues may only be required at the remote latches of pawl sub-assemblies 33a and 33b.

In operation, rotating driver <NUM> of latch <NUM> causes pawl <NUM> of pawl sub-assembly <NUM> to move between the locked and unlocked states, as was described in detail above.

Shaft <NUM> moves with pawl <NUM>, as was described above. Rotation and translation of shaft <NUM> of latch <NUM> (as described above) also causes simultaneous rotation of cam 114c about axis A as well as resultant translation of cam 114c along axis A. Rotation and translation of cam 114c causes simultaneous rotation of rod <NUM> about axis A as well as resultant translation of rod <NUM> along axis A. Rotation and translation of rod <NUM> causes simultaneous rotation of cams 114a and 114b about their respective axes B as well as resultant translation of cams 114a and 114b along their axes B. Rotation and translation of cams 114a and 114b causes simultaneous rotation of shafts <NUM> and pawls <NUM> of pawl subassemblies 33a and 33b about their respective axes B as well as resultant translation of shafts <NUM> and pawls <NUM> of pawl subassemblies 33a and 33b along respective axes B. Accordingly, in summary, rotation and translation of shaft <NUM> of latch <NUM> causes simultaneous rotation and translation of three separate pawls <NUM>, i.e., pawls <NUM> of pawl subassemblies <NUM>, 33a and 33b. Each pawl <NUM> provides a separate point of contact for latching door <NUM> in a closed and locked state.

A handle <NUM> is either connected to or extends from cam 114c. Alternatively, handle <NUM> extends from pawl <NUM> of latch <NUM>. Handle <NUM> is non-rotatably connected to shaft <NUM>. Multi-point latch <NUM> can be operated using handle <NUM> in the same manner as described above with respect to driver <NUM>. In other words, rotation of handle <NUM> causes rotation and translation of three pawls <NUM> between locked and unlocked states. Handle <NUM> is provided on the rear side 12b of door <NUM> to prevent a user from inadvertently being locked inside of a compartment, such as a freezer or refrigerated compartment.

Claim 1:
A compression latch (<NUM>, <NUM>) for a door comprising:
a driver (<NUM>) that is rotatable with respect to the door between an unlocked position and a locked position, said driver (<NUM>) being configured to be mounted to one side of the door,
a driver shaft (<NUM>) that is non-rotatably connected to the driver (<NUM>) such that said driver shaft (<NUM>) rotates along with said driver (<NUM>), and
a pawl assembly (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) that is configured to be mounted to an opposite side of the door, said pawl assembly (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) comprising (i) a housing (<NUM>) that is configured to be fixedly mounted to the door, and (ii) a pawl (<NUM>) that is movably connected to the housing (<NUM>) and is configured to both rotate and translate with respect to the housing (<NUM>) in response to rotation of the driver shaft (<NUM>,
wherein, in an unlocked position of the driver (<NUM>), the pawl (<NUM>) is positioned to permit opening of the door, and, in a locked position of the driver (<NUM>), the pawl (<NUM>) is positioned to prevent opening of the door, and
wherein the compression latch (<NUM>, <NUM>) is configured to translate the pawl (<NUM>) closer toward the door upon rotating the driver (<NUM>) from the unlocked position to the locked position;
wherein the driver shaft (<NUM>) includes a proximal end that is non-rotatably connected to the driver (<NUM>), and a distal end that is non-rotatably connected to said pawl (<NUM>);
wherein the pawl (<NUM>) is fixedly connected to a shaft of the pawl assembly (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>), and the shaft of the pawl assembly (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) is non-rotatably connected to the driver shaft (<NUM>); and
wherein the shaft of the pawl assembly (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) includes a threaded shaft (<NUM>) that is configured to be connected to the pawl (<NUM>), and characterized in that a sleeve (<NUM>) is non-rotatably connected to the threaded shaft (<NUM>) as well as the driver shaft (<NUM>).