Compression latch

[0001] 1. Field of Invention

[0002] The present invention relates to a compression latch for selectively maintaining a panel or door in a closed position relative to a doorframe or the like.

[0003] 2. Brief Description of the Related Art

[0004] In many applications the need arises to selectively maintain a panel or door in a closed position relative to a doorframe or the like, while developing a compressive force between the door or panel and the doorframe. For example, when a gasket is used to provide a seal between a door and a doorframe when the door is closed, it would be desirable for the latch holding the door closed to provide a compressive force to compress the gasket between the door and the doorframe to effectively seal the any gap or seam between the door and doorframe. Latches that develop this type of compressive force between the door and doorframe are known as compression latches. An example of a known compression latch can be seen in U.S. Pat. No. 4,763,935, issued to Robert H. Bisbing on Aug. 16, 1988, the entire disclosure of which is incorporated herein by reference.

[0005] The compression latch of U.S. Pat. No. 4,763,935 does not provide for a handle that can be folded down in both the latched and unlatched configurations. In certain applications it is desirable to have a compression latch with a handle that can be folded down in both the latched and unlatched configurations so that a user's clothing or body parts will not catch on the handle even when the latch remains unlatched during intervals of time when it is more convenient to leave the latch in the unlatched configuration to allow repeated access through the door. An example of this type of application is a latch for the door of a holding tank for storing the catch in a sport fishing boat. The need persists in the art for a compression latch that has a handle that can be folded down to be practically flush with the exterior surface of the door in both the latched and unlatched configurations.

[0006] The present invention is directed to a compression latch with a folding handle for selectively holding a door closed. The latch includes a housing with a cup portion for receiving the handle in the folded down position such that the projection of the latch handle above the exterior surface of the door is minimized in the folded-down position. The handle functions to move a pawl in a combination of rotational and linear translational movements as the pawl is moved between latched and unlatched positions.

[0028] Like reference numerals indicate like elements throughout the several views.

[0029] The present invention is directed to a latch for selectively maintaining a first member in a closed position relative to a second member. The first member, for example, may be a door and the second member, for example, may be a doorframe or a keeper attached to the doorframe. The latch of the present invention in general comprises a housing adapted for mounting to the first member; a pivotal handle supported relative to the housing such that the handle can be folded down relative to the housing; a pawl; and means for moving the pawl in a combination of rotational and linear translational movements responsive to at least some movements of the handle. The latch pawl is movable between a latched position and an unlatched position and the handle can be folded down when the rotational position of the pawl corresponds to both the latched and unlatched positions. By appropriate movement of the handle, the pawl can be rotated to bring the pawl into position behind a portion of the doorframe or a keeper. Further movement of the handle in a predetermined manner causes linear translation of the pawl toward the door, thus capturing the portion of the doorframe or the keeper between the pawl and the door to thereby apply a compressive force to a gasket or the like between the door and doorframe. With the latch in this configuration, the door is secured in the closed position with respect to the doorframe while any gap or crevice between the door and the doorframe is sealed by the compressive action of the latch.

[0030] The latch housing has a cup-like portion designed to receive at least a substantial enough portion of the latch handle when the latch handle is folded down such that there is a reduced chance of a users clothing or body parts catching on the handle. Preferably, at least a majority of the thickness of the handle is received within the cup-like portion of the housing when the latch handle is folded down. Even more preferably, substantially the entire thickness of the handle is received within the cup-like portion of the housing when the latch handle is folded down such that the projection of the latch handle above the exterior surface of the door is minimized in the folded-down position.

[0031] The latch housing is adapted to be mounted in an opening in the door such that the latch housing projects to only a small height above the exterior surface of the door when the latch housing is mounted in the door. This small height is equivalent to the thickness of a flange or bezel that surrounds the open top of the cup-like portion of the latch housing. Desirably, the latch handle is substantially flush with the flange or bezel of the cup-like portion of the latch housing when the latch handle is in the folded down position. In the latch of the present invention, the latch handle can be folded down to be substantially flush with the flange or bezel of the cup-like portion of the latch housing with the latch pawl is in both the latched and unlatched positions. The cup-like portion of the latch housing is sized and shaped to correspond at least with key portions of the outline of the latch handle in plan view such that the handle can only be folded down to be received in the cup-like portion when the pawl is in a rotational position corresponding to the latched and unlatched positions of the pawl. Any attempt to fold down the latch handle will fail when the pawl is not in a rotational position corresponding to the latched and unlatched positions of the pawl, because portions of the latch handle will be out of alignment with the open top of the cup-like portion of the latch housing and thus the latch handle cannot fold down into the cup-like portion of the latch housing.

[0032] Referring to FIGS. 1-41, an illustrative example 100 of a latch according to the present invention can be seen. The latch 100 includes a handle 102, a wear washer 104, a housing 106, a pair of o-rings 108, an o-ring washer 110, a coil spring 112, a collar 114, a shaft 116, a handle pivot pin 118, a retainer pin 120, a pawl 122, and pawl nuts 124. As best seen in FIGS. 4-8, the handle 102 is generally D-shaped and has an opening 126 that allows a user to insert a finger the opening in order to grasp the handle 102. The handle 102 is provided with a pair of extensions 128 and 130. Each of the extensions 128 and 130 has a hole, 132 and 134 respectively, that are in alignment with one another. The handle 102 has first, second, third, fourth, and fifth surface portions, 136, 138, 140, 142, and 144 respectively, whose functions will be described later.

[0033] As best seen in FIGS. 9-13, the latch housing 106 has a cup-like portion 146, a flange or bezel 148, and a sleeve portion 150. The sleeve portion 150 has a bore 152, a top opening 154, and a bottom opening 156. The top opening 154 has a smaller diameter than at least a portion of the bore 152. In the illustrated example, the bore 152 has a substantially uniform diameter and the bottom opening 156 is of essentially the same diameter as the bore 152. The transition between the diameter of the bore 152 and the diameter of the top opening 154 forms an annular shoulder 158 near the top opening 154 of the sleeve portion 150. The housing 106 has a pair of notches 160, near the bottom opening 156. The housing 106 has at least one threaded hole 162, and preferably a pair of threaded holes 162, that open to the bottom of the cup-like portion 146 of the housing 106. The housing 106 may also be provided with a finger groove 172 that provides enough clearance for a user's finger to reach under the handle 102 when it is folded down.

[0034] As best seen in FIGS. 16-18, the shaft 116 has a portion 164 that has threads that are interrupted by flat sides 166 on either side of the threaded portion 164. The shaft 116 is provided with a first hole 168 that passes through the shaft, transverse to the longitudinal axis of the shaft, at a location near the top end of the shaft. The shaft 116 is provided with a second hole 170 that passes through the shaft, transverse to the longitudinal axis of the shaft, at a location near the top end of the threaded portion 164 of the shaft 116.

[0035] The shaft 116 is positioned at least in part within the bore 152 of the sleeve portion 150. The shaft 116 extends through the top opening 154 of the sleeve portion 150 such that the top end portion of the shaft 116 is located in the cup-like portion 146 of housing 106. The top end portion of the shaft 116 located in the cup-like portion 146 of housing 106 is received between the pair of extensions 128 and 130 such that the holes 132 and 134 are in registry with the hole 168 of the shaft 116. The pin 118 passes through the holes 132 and 134 of the pair of extensions 128 and 130 and the hole 168 in the top end portion of the shaft 116 to pivotally connect the handle 102 to the shaft 116. Optionally, the shaft 116 may pass through a wear washer 104 that is positioned intermediate the handle 102 and the bottom of the cup-like portion 146 of the housing 106. The wear washer 104 reduces the wear on the housing 106 by providing a bearing surface against which the surface portions 136, 138, 140, 142, and 144 of the handle 102 can bear as the handle 102 is alternately folded and raised. Thus, the wear washer 104 allows the housing 106 to be manufactured from less expensive materials. However, it is also possible for the surface portions 136, 138, 140, 142, and 144 of the handle 102 to bear directly against the bottom of the cup-like portion 146 of the housing 106 while still allowing the latch 100 to function as intended.

[0036] The two o-rings 108 are positioned in tandem in the bore 152 such that the o-rings surround the shaft 116 and the top o-ring bears against the shoulder 158. The o-ring washer 110 is positioned in the bore 152 adjacent the lower o-ring and also surrounds the shaft 116. The o-ring washer 110 provides a protective surface for one end of the spring 112 to bear against while reducing wear to the o-rings 108. The spring 112 is also positioned within the bore 152 of the sleeve portion of the housing 106 and its coils surround the shaft 116. The collar 114 is positioned adjacent the lower end of the spring 112, encircles the shaft 116, and lies at least in part within the bore 152 of the sleeve portion of the housing 106. The ends of the pin 120 project outward from the shaft 116. The collar 114 is captured between the pin 120 and the lower end of the spring 112. The pin 120 keeps the assembled latch from falling apart. The spring 112 is under compression and acts as a biasing means tending to bias the threaded portion 164 of the shaft 116 away from housing 106. The biasing force of the spring 112 is applied to the shaft 116 via the collar 114 and the pin 120. The o-rings 108 seal any crevices between the shaft 116 and the top opening 154 of the sleeve portion of the housing 106. This feature is particularly desirable when the latch 100 is to be used for marine applications and passage of salt water through the latch is to be avoided. As an alternative, the collar 114 may have holes that are in registry with the hole 170, thus allowing the shaft 120 to pass through both the collar 114 and the shaft 116.

[0037] Referring to FIGS. 1, 34 and 35, the latch 100 is mounted to an opening or hole in the door 174. The opening in the door 174 is shaped and sized to provide clearance for the side walls of the cup-like portion 146 of the housing 106 but not for the flange 148. To mount the latch 100 to the door 174, the cup-like portion 146 of the housing 106 is placed through the opening in the door 174 such that the underside of the flange 148 abuts the exterior surface of the door 174. A bracket 176 is placed over the cup-like portion 146 of the housing 106 such that the surface of the rim 178 of the bracket 176 abuts the interior surface of the door 174. The dimension of the bracket 176 measured across the rim 178 is too large to clear the opening in the door 174. A pair of fasteners 180 is used to secure the bracket 176 to the housing 106. Thus, at least a portion of the door 174 is captured intermediate the flange 148 and the bracket 176 to secure the latch 100 to the door 174. An optional gasket may be provided between the flange 148 and the exterior surface of the door 174 to seal off any crevices between the housing 106 and the door 174 in applications where leak-proofing the latch is important.

[0038] The pawl 122 has one end that is adapted for engaging the door frame 182, or a keeper, when the pawl 122 is in the latching configuration shown in FIG. 1. The pawl 122 has a hole 184 through the end opposite the end adapted to engage the doorframe 182. The hole 184 is shaped to correspond to the cross section of the threaded portion 164 of the shaft 116 and has flat sides that engage the flat sides 166 of the threaded portion of the shaft 116 such that the shaft 116 and the pawl 122 rotate together as a unit about the longitudinal axis of the shaft 116 when the threaded portion of the shaft 116 is placed through the hole 184 of the pawl 122. The pawl 122 is adjustably secured in position along the threaded portion 164 of the shaft 116 by a pair of nuts 124. The nuts 124 are engaged to the threaded portion of the shaft 116 and tightened against the pawl 122 to secure the pawl 122 in place once the pawl is mounted on the threaded portion of the shaft 116. Lock washers 186 can be provided intermediate the pawl 122 and the nuts 124 to reduce the chance of the nuts 124 becoming loose during operation and use of the latch 100.

[0039] The handle 102 can be moved pivotally between an extended configuration (shown in FIGS. 37 and 39) and one of a first folded-down configuration (shown in FIG. 1) and a second folded-down configuration (shown in FIG. 41). The latch 100 secures the door 174 in a closed position against the doorframe 182 when the latch 100 is mounted to the door 174 and the pawl 122 is in the latched position such that it engages the doorframe 182 as shown in FIG. 1. With the latch in the latched configuration of FIG. 1, the handle 102 can be folded down to the first folded-down configuration as shown in FIG. 1.

[0040] The pivot pin 118 defines a pivot axis for the handle 102 that is orthogonal to the longitudinal axis of the shaft 116. With the handle 102 in the configuration shown in FIG. 1, the pawl 122 is in the latched position and the handle 102 is in the first folded-down configuration. Also, with the handle 102 is in the first folded-down configuration, the surface portion 138 is positioned between the pivot axis of the handle 102 and a bearing surface at the bottom of the cup-like portion of the housing 106. The bearing surface can be provided either by the bottom of the cup-like portion of the housing or by the wear washer 104. When the handle 102 is moved to the extended configuration of FIGS. 37 and 39, the surface portion 136 becomes positioned between the pivot axis of the handle 102 and the bearing surface at the bottom of the cup-like portion of the housing 106. The result of moving the handle 102 from the first folded-down configuration to the extended configuration is that the pawl linearly translates away from the housing 106 to thereby release the compressive force being exerted between the door 174 and the door frame 182, because the surface portion 136 is closer to the pivot axis of the handle than the surface portion 138. Now the handle 102 can be rotated about the longitudinal axis of the shaft 116 to rotate the shaft 116 and thereby rotate the pawl 122 out from behind the doorframe 182. Usually a rotation of 90° or less is sufficient to rotate the pawl 122 out from behind the doorframe 182 and allow opening of the door 174. However in the illustrated embodiment the handle 102 must be turned substantially 180° before the handle 102 can be folded down into the cup-like portion 146 with the pawl 122 in the unlatched position. The handle 102 will be, in the second folded-down configuration of FIG. 41 when it is folded down into the cup-like portion 146 with the pawl 122 in the unlatched position. In the second folded-down configuration, the surface portion 140 becomes positioned between the pivot axis of the handle 102 and the bearing surface at the bottom of the cup-like portion of the housing 106. The pawl and shaft will not linearly translate as a result, because the distance between the pivot axis of the handle 102 and the surface portion 140 is not appreciably different from the distance between the pivot axis of the handle 102 and the surface portion 136. The pawl 122 will now be maintained in the unlatched position because the walls of the cup-like portion of the housing 106 prevent rotation of the handle 102 about the longitudinal axis of the shaft 116.

[0041] To once again latch the door 174, the handle is lifted from the second folded-down configuration to the extended configuration. The handle 102 can is then rotated about the longitudinal axis of the shaft 116 to rotate the pawl 122 into position behind the doorframe 182. The handle 102 is then folded down from the extended configuration to the first folded-down configuration to cause the pawl 122 to linearly translate toward the housing 106 and to thereby squeeze the door 174 and the door frame 182 together in a secured relationship. The pawl 122 will now be maintained in the latched position because the walls of the cup-like portion of the housing 106 prevent rotation of the handle 102 about the longitudinal axis of the shaft 116. Although in the illustrated example the handle must be turned 180° to allow the handle to be folded down with the pawl unlatched, it is possible to arrange for the handle to be folded down at any angle, so long as the pawl is unlatched, by appropriate selection of the geometry of the cup-like portion of the housing 106 and the handle 102.

[0042] The surface portions 142 and 144 are positioned farther from the pivot axis of the handle 102 as compared to surface portions 140 and 138, respectively, such that the resistance of the spring 112 provides a detent action to deter uncontrolled movement of the handle between folded and extended configurations. In the illustrated embodiment the surface portions 136, 138, 140, 142, and 144 are integral with the handle 102.

[0043] The sleeve portion of the housing 106 may be provided with notches 160 that receive the ends of the pin 120 in the latched configuration for further strength and security. In the illustrated embodiment, the surface portion 138 is provided by a raised boss 188 that provides a visual and tactile indication of the unlatched state of the latch 100. It is also possible to provide other or additional alphanumeric or iconographic indicia to indicate the state of the latch 100 to a user.

[0044] It is to be understood that the present invention is not limited to the embodiments described above, but includes any and all embodiments within the scope of the appended claims. Furthermore, it is to be understood that the embodiments of the present invention disclosed above are susceptible to various modifications, changes and adaptations by those skilled in the art, without departing from the spirit and scope of the invention.