The present invention relates generally to rotary actuation latches, whereby when the latch is locked, certain features of the latch may be intentionally disconnected to protect against impermissible entry and damage to the latch.
Various latches are operated via a rotatable handle member. For example, D-Ring and Folding-T handles have been in use for many years. In some such latches, a portion of the handle is first folded outward from a handle tray before rotating the handle. The handle in such case may include a shaft rotatable mounted on the tray. Rotation of the shaft via the handle typically moves elements on a back side of the tray to thereby effect the desired latching or unlatching. Often a latch (or pawl) mounted for rotation with the shaft will be put in place by rotation of the handle and shaft. Also, a rotating member can be provided on the back side of the tray to actuate remote latches via rods or the like.
Certain rotary latches are considered compression latches. In a compression latch, the pawl moves axially along a handle or lock shaft as well as rotationally around the axis of the shaft. Such motion may occur various ways—either sequentially axially and rotationally, or including a blend of both. Such axial motion in compression latches is useful in ensuring a tight closure and also allowing for a reduction or elimination of friction between the pawl and closure surface during rotational motion when rotating the shaft.
Rotary latches (both compression latches and others) may incorporate locks to prevent unauthorized opening of the compartments upon which they are mounted. Various designs and strategies have been employed with such locking rotary latches. For example, a padlock may be attached to the latch to prevent the handle from being lifted or rotated. Also, a key cylinder may be employed as part of the rotary shaft, or to hold in place the handle or various components. In previous devices, these locks prevented unauthorized opening by causing a frictional interference between elements—such as precluding the sliding or rotating of parts on the inside of the latch assemblies. At times, these rotary operated latches or their locks could be overcome by “brute force,” such as use of a hammer or crowbar, to bend or break the latches at the point of interference, thereby allowing the latches to be opened. Also, locks or the shafts of rotary latches have been on occasion “drilled out” to overcome the lock.
Accordingly, a rotary operated latch with locking capabilities that addresses one or more of the drawbacks of previous latches or other goals would be welcome.
According to certain aspects of the invention, a rotary actuation latch with disconnect feature is disclosed, the latch including a tray for attachment to one of a door or a frame, the tray having a front side and a rear side, a rotary member rotatably mounted to and extending through the tray, the rotary member being movable along a longitudinal axis relative to the tray between a first position and a second position, a pawl disposed on the rear side of the tray for engaging the other of the door or the frame for securing the door in a closed position, the pawl having a drive interface disposable in either of a drive position or a disconnect position relative to the rotary member, the pawl being rotatable via the rotary member when the drive interface is in the drive position, and a locking device attached to the tray and movable between a locked position and an unlocked position. The locking device when in the locked position prevents the pawl drive interface from being disposable in the drive position while not preventing the rotary member from moving along the longitudinal axis between the first and second positions. Various options and modifications are possible.
For example, the pawl may be movable along the longitudinal axis when the pawl drive interface moves between the drive position and the disconnect position, and the pawl may be spaced further from the rear side of the tray when the pawl drive interface is in the drive position as compared to the disconnect position. A compression spring member may be disposed between the tray and the pawl for urging the pawl drive interface toward the drive position. The rotary member may include a shaft and a disconnector attached to the shaft, the disconnector including a drive interface for selectively engaging the drive interface of the pawl to rotate the pawl when the rotary member is disposed in the second position if the pawl drive interface is in the drive position. The compression spring member may comprise a first compression spring member, the latch further including a second compression spring member disposed between the tray and the disconnector for urging the disconnector away from the rear side of the tray.
A handle may be pivotally mounted to the rotary member on the front side of the tray, the handle movable between a first position and a second position to thereby move rotary member along the longitudinal axis between its respective first and second positions, the rotary member being rotatable via the handle when the handle is in the second position.
The pawl may include a stop interface for preventing rotation of the pawl when the handle is not in the second position. A stop interface may also be attached to the tray for selectively engaging the stop interface on the pawl when the handle is not in the second position.
The locking device includes a locking cylinder and a locking bar, the locking cylinder selectively positioning the locking bar between a locked position and an unlocked position. The locking bar may have a lock interface for preventing movement of the pawl drive interface from the disconnect position to the drive position when the locking bar is in the locked position. The pawl may have a lock interface for selective engagement by the locking bar lock interface.
The rotary member and the pawl may be configured to function as a compression latch. The pawl drive interface may be movable along the longitudinal axis between the drive position and the disconnect position, and the pawl drive interface may be spaced further from the rear side of the tray when in the drive position as compared to the disconnect position, a compression spring member being disposed between the tray and the pawl for urging the pawl drive interface toward the drive position. A handle may be pivotally mounted to the rotary member on the front side of the tray, the handle movable between a first position and a second position to thereby move rotary member along the longitudinal axis between its respective first and second positions, the rotary member being rotatable via the handle when the handle is in the second position.
According to certain other aspects of the invention, a rotary actuation latch with disconnect feature is disclosed, the latch including a tray for attachment to one of a door or a frame, the tray having a front side and a rear side, a handle assembly rotatably mounted to and extending through the tray, the handle assembly being movable along a longitudinal axis relative to the tray between a first position and a second position, a pawl disposed on the rear side of the tray for engaging the other of the door or the frame for securing the door in a closed position, the pawl being selectively connectable or disconnectable for rotation via the handle assembly, and a locking device attached to the tray and movable between a locked position and an unlocked position. The locking device when in the locked position disconnects the pawl from rotation via the handle assembly while not preventing the handle assembly from moving along the longitudinal axis between the first and second positions or from rotating around the longitudinal axis when in the second position. Again, various options and modifications are possible.
According to other aspects of the invention, a rotary actuation compression latch with disconnect feature is disclosed, the latch including a tray for attachment to one of a door or a frame, the tray having a front side and a rear side, a handle assembly rotatably mounted to and extending through the tray, the handle assembly being movable along a longitudinal axis relative to the tray between a first position and a second position, a pawl disposed on the rear side of the tray for engaging the other of the door or the frame for securing the door in a closed position, the pawl being rotatable via the handle assembly between a latched and an unlatched position, the handle assembly and pawl cooperating to provide a compression latching function along the longitudinal axis, a locking device attached to the tray and movable between a locked position and an unlocked position, and a means for disconnecting the pawl from rotation via the handle assembly while maintaining the compression latching function when the locking device is in the locked position. Various options and modifications are possible.
For example, the means for disconnecting may include a locking interface disposed on the locking device and the pawl for preventing the pawl from rotating with the handle assembly when the locking device is in the locked position. Or the pawl may be movable along the longitudinal axis, the locking interface precluding movement of the pawl along the longitudinal axis when the locking device is in the locked position. Also, the means for disconnecting may include a drive interface disposed on the pawl and the handle assembly engageable when the handle assembly in the second position and the locking device is in the unlocked position to thereby allow rotation of the pawl via the handle assembly. Also, a stop interface may be disposed on the pawl and attached to the tray for precluding rotation of the handle assembly when the handle assembly is in the first position.
Reference will now be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, and not meant as a limitation of the invention. For example, features illustrated or described as part of one embodiment can be used with another embodiment to yield still a third embodiment. It is intended that the present invention include these and other modifications and variations. In discussing various embodiments, like or similar reference numerals are used below with like or similar parts of various embodiments.
One example of a rotary actuation latch according to certain aspects of the invention is shown in
Tray assembly 102 may be said to include tray (sometimes called a pan) 110 and matching gasket 112. Tray 110 and gasket 112 have matching holes 114 for mounting latch 100 to a desired surface S1, such as a door mounted in a second surface S2. Alternatively, surface S1 could be a wall and surface S2 could be a door. Only portions of surfaces S1 and S2 are shown throughout the figures for clarity, but various it should be understood that various orientations could be employed.
A front shank 116 is disposed within an opening 118 in tray 110. Shank 116 and opening 118 have one or more mating portions 120 and 122 to prevent relative rotation once attached. Shank 116 is attached to tray 110 via threads 124 that mate with threads within locking nut 126. Lip 128 of shank 116 holds the shank in place once the nut is tightened over threads 124.
A locking bar plate 130 is attached to tray 110 via rivets 132. Locking bar plate 130 may be considered part of tray assembly 102 or locking device assembly 106, or both. Locking bar plate 130 includes an opening 134 sized to receive shank 116, and may include one or more mating portions 136 to interact with mating portions 120 to assist in holding the shank in place. Locking bar plate 130 has a tab 138 extending outwardly, the function of which will be described below.
Handle assembly 104 includes a handle 140 pivotally attached to a rotary member such as a shaft 142 via a rivet 144 or the like. Handle 140 as illustrated is formed generally in a loop, but various other shaped could be provided, such as a D-shape, a T-shape, an L-shape, etc. Therefore, no limitation is meant as to the shape of handle 140.
Handle 140 includes a contact portion 146 including two flats 148 and 150, located at different distances and orientations from center axis 152 of rivet 144. A transition 154, which may be a curve or one or more flats, may be located between flats 148 and 150. A shank washer 156 fits over the end of shaft 142 between a flange portion 158 of the shaft and contact portion 146 of handle 140. Once latch 100 is assembled, the two main functional positions of handle assembly 104 are defined by the shape and location of flats 148 and 150 with reference to contact with washer 156, as will be described below.
A disconnector 160 is attached to shaft 142 via a screw 162 or the like. Shaft 142 may have mating surfaces 164 for contacting cooperative surfaces 165 within disconnector 160 to prevent relative rotation once assembled.
Handle assembly 104 is movable along a longitudinal axis 166 from the position shown in
Pawl assembly 108 includes a pawl arm 184 mounted to a rear shank 186 via screws 188 or the like. As illustrated, pawl arm 184 is adjustable and includes a friction reducing roller, although various other types of pawl designs could be employed. In particular, pawl arm 184 includes a cam arm 190, a slider 192, a partially threaded screw 194, a roller 196, and a washer 198. Threaded portion 200 of screw 194 is placed through slot 202 in arm 190 and tightened into threaded hole 204 in slider 192 in a desired position to adjust the screw/roller height to a desired level with reference to tray 110 and the enclosure.
Rear shank 186 fits partially over front shank 116, and disconnector 160 fits within the rear shank. A compression spring member 206 is disposed between a third stop portion 208 of front shank 116 and a stop portion 209 of rear shank 186. Therefore, compression spring member 206 urges the two shanks 116 and 186 apart, and urges rear shank 186 into contact with disconnector 160. The shanks 116,186, the handle assembly 104, and the spring members 170, 206 should be assembled before pawl arm 184 is attached to the rear shank. Compression spring member 206 should provide a force strong enough to ensure that rear shank 186 can be moved against disconnector 160 when desired.
Locking device assembly 106 includes a lock device 210, such as a key cylinder. It should be understood that lock device 210 could comprise other such devices and mechanisms, such as a padlock controlled mechanism or the like. As illustrated lock device 210 may be mounted to tray 110 via a threaded nut 212 and gasket 214, as shown. Hole 216 and lock device 210 may have mating surfaces 218, 220 to prevent rotation once installed.
A locking cam 222 is attached to a rear drive portion 224 of locking device 210. Cam 222 may be secured by an orienting washer 226, a lock washer 228 and a lock nut 230, or other structure. As shown in
A locking interface 242 is provided between the locking bar 232 and the rear shank 186 of pawl assembly 108. As illustrated, locking interface comprises arms 244 extending from rear shank 186 and corresponding slots 246 located in locking bar 232. When locking bar 232 is slid upwardly by cam 222, arms 244 fit within slots 246, thereby preventing rotation of rear shank 186 about axis 166, and also preventing the rear shank from sliding axially away from the rear 176 of tray 110. Therefore, as shown in
A pawl drive interface 248 is provided on the handle assembly 104 (in this case disconnector 160) and the pawl assembly 108 (in this case rear shank 186). Pawl drive interface 248 may comprise mating stepped portions 250, 252 of disconnector 160 and rear shank 186. When pawl drive interface 248 is in a drive position and the locking device 210 is in the unlocked position (see
A stop interface 254 is disposed on the pawl assembly 108 (in this case rear shank 186) and the tray assembly 102 (in this case front shank 116) for preventing rotation of pawl assembly 108 when the handle assembly 104 is not in the second position (see
If desired, mating step portions 256, 258 of stop interface 254 can be formed with three levels 256a-c and 258a-c, thereby forming two “steps.” When stop interface 254 of shanks 116 and 186 are in the full stop position (see
If desired, as a matter of design choice, stepped portions 250, 252 of pawl drive interface 248 can be formed with two steps as well, although such does provide less of a disconnect function than allowing free 360 rotation when in the disconnect position. Also, if less than 360 degree rotation of handle shaft 142 is desired when the pawl assembly 108 is in a disconnected (locked) orientation, a different stop interface could be provided between handle assembly 104 (such as shaft 142) and tray assembly 102 (such as front shank 116) or locking device assembly 106 (such as locking bar 232), instead of using a two-stepped interface between disconnector 160 and rear shank 186.
It may be desirable to make the depth of the stepped portions 250, 252 on the drive interface 248 axially smaller than the difference between step portions 256a/258a and 256b/258b of stop interface 254, so that the handle assembly disconnect function is actuated before the handle assembly 104 becomes rotatatble. In other words, as the handle 140 is pivoted upwards while the device is unlocked, the handle shaft 142 will move axially and cause the disconnector 160 to disconnect from rear shank 186 at the drive interface 248 before stop interface 254 is moved to a position allowing any rotation of the handle shaft 142. Also, the configuration of flats 148 and 150 and transition 154 of handle 140 can be designed for a desired effect on the axial location shaft 142 during the travel of handle when pivoted upwardly. Such spacing may provide further deterrent to impermissible opening of latch 100 through damage to handle 140, etc., by folding the handle out and then forcing it with a crowbar or the like to bend or break internal parts of latch related to the lock or opening functions. By causing the disconnect function to occur upon somewhat slight movement pivoting of handle 140, the possibility of damage in such situation is lessened. Also, for additional security ridge 260 of tray 110 can be formed so as to surround handle 140 (so that handle 140 sits within the ridge on front side 262 of the tray), whereby the disconnect function can occur before 140 handle is lifted out far enough to be able to get at it with a crowbar or other implement.
To operate the latch 100, from the unlocked position shown in
Handle assembly 104 can thus be rotated to the position shown in
The latch 100 may be locked by returning handle assembly 104 to the latched position (
If handle 140 is pivoted upward from the position of
If the locking device 210 is unlocked at this point, locking bar 232 will move downward due to spring 238, and then front shank 116 will be slid rearward by spring 206, thereby moving stop interface 254 to a rotatable (partially rotatable) position, and moving the drive interface elements (186 and 160) into contact with each other. If steps 250 and 252 are not initially aligned to allow pawl assembly 108 to be driven, further rotation of handle 140 and disconnector 160 will cause steps 250 and 252 to eventually become aligned, thereby moving the drive interface to the drive position of
If latch 100 is in the position of
Therefore, latch 100 provides a rotary latching mechanism suitable for use with various types of rotary handles beyond those described above. Latch 100 includes compression features, although several of the concepts above can be applied to non-compression style rotary operated latches. Latch 100 also provides a disconnect function which can be applied to various other latches. Use of the compression and disconnect features together provides numerous advantages, although such features may be employed separately if desired.
Latch 100 may be economically manufactured of conventional metals and plastics. In particular, it may be advantageous to mold various elements (such as the locking bar, rear shank, and/or disconnector, etc) of plastics to reduce weight and cost, because the disconnect feature prevents their being subject to high stresses.
It should be understood that the foregoing description provides only exemplary embodiments and discussion of examples of the invention. Various modifications and options are possible. Accordingly, set forth below are claims covering certain aspects of the invention; however, a full scope of the invention is to be ascertained from the claims, their equivalents, and the full contents of this application.