This disclosure relates to the field of latch assemblies.
As is described in U.S. Pat. No. 8,496,275 to Garneau and U.S. Pat. No. 7,455,335 to Garneau, each of which is incorporated by reference herein in its entirety, latch assemblies are relied on in many applications for securing items, such as panels, doors, and doorframes together. For example, containers, cabinets, closets, drawers, compartments and the like may be secured with a latch. Furthermore, in many applications an electrically operated latch is desirable due to the need for remote or push-button entry, coded access, key-less access, or monitoring of access.
Various latches for panel closures have been employed where one of the panels such as a swinging door, drawer or the like is to be fastened or secured to a stationary panel, door frame, cabinet, or compartment body. There continues to be a need for improved latching systems in the interests of security to prevent unauthorized opening of latching systems.
Aspects of the invention relate to an electromechanical locking latch.
In accordance with one aspect, the invention provides an electronic latch assembly comprising a latch bolt that is movable between an extended position and a retracted position. A motor having a rotatable output shaft arrangement is either directly or indirectly connected to the latch bolt for moving the latch bolt between the extended and retracted positions and rotating the output shaft arrangement between a first angular position in which the latch bolt is capable of being translated to the retracted position and a second angular position in which the latch bolt is locked and not capable of being translated to the retracted position.
According to another aspect, the invention provides an electronic latch assembly comprising a housing including an interior compartment and a stopping surface defined within the interior compartment. A latch bolt is positioned at least partially within the interior compartment, and the latch bolt is movable between an extended position and a retracted position. A motor having a rotatable output shaft arrangement is either directly or indirectly connected to the latch bolt for moving the latch bolt between the extended and retracted positions. A protrusion extends from the output shaft arrangement. At a first angular position of the output shaft, the protrusion is maintained in an unlocked state in which the protrusion is separated from the stopping surface to permit movement of the latch bolt toward the retracted position. At a second angular position of the output shaft, the protrusion is maintained in a locked state in which the protrusion is positioned against the stopping surface to prevent movement of the latch bolt toward the retracted position.
According to yet another aspect, the invention provides an electronic latch assembly for selectively engaging a door opening. The electronic latch assembly comprises a housing including an interior compartment. A latch bolt is at least partially positioned within the interior compartment and movable between an extended position for engaging the door opening and a retracted position in which the latch bolt is disengaged from the door opening. A motor having a rotatable output shaft arrangement is either directly or indirectly connected to the latch bolt for moving the latch bolt between the extended and retracted positions. A spring-loaded lever is attached to the housing for biasing the electronic latch assembly away from the door opening when the latch bolt is maintained in the retracted position. A sensor for sensing a position of the lever communicates the sensed position of the lever to a controller of the electronic latch assembly.
The invention is best understood from the following detailed description when read in connection with reference to the accompanying drawings. According to common practice, the various features of the drawings are not drawn to scale unless otherwise indicated. On the contrary, the dimensions of the various features may be expanded or reduced for clarity. Included in the drawings are the following figures:
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 the range of equivalents of the claims without departing from the invention.
As used herein, “proximal” and “distal” refer to either a position or a direction relative to the latch bolt opening 9. For example, a proximal portion of a particular component is a portion nearer latch bolt opening 9, and a distal portion is a portion further from latch bolt opening 9. Furthermore, a proximal direction is a direction toward latch bolt opening 9 and a distal direction is a direction away from latch bolt opening 9.
Latch assembly 10 can be fixed to a moveable door (not shown) for selectively mating with a stationary door opening (not shown), or vice versa, for example. For the purpose of simplicity, it should be assumed hereinafter that latch assembly 10 is permanently fixed to the moveable door, and latch assembly 10 selectively mates with an aperture of a stationary door opening.
Base portion 12 and lid portion 14 together form a hollow interior space in which internal components of the latch assembly 10 are positioned. Detailed views of base portion 12 are shown in
Three of the internal components positioned within the hollow interior space of housing enclosure 11 extend at least partially outside of housing enclosure 11, i.e., items 13, 15 and 19, as is shown in
More particularly, a bolt portion 20 of a spring-loaded latch bolt 13 extends through an opening 9 defined in the side of housing enclosure 11 for selectively engaging a stationary door opening (not shown), for example. Latch bolt 13 is moveable between the extended position shown in
A spring-loaded lever 15 extends through a different opening defined in the same side of housing enclosure 11 for selectively engaging with the stationary door opening, for example. Lever 15 is configured to bias the door (not shown) away from the door opening (not shown). In operation, starting from a closed position of the door, to which latch assembly 10 is mounted, upon moving latch bolt 13 to the retracted position shown in
A control switch 19 is provided on the outer surface of housing enclosure 11 for manually operating latch assembly 10.
Referring now to the components associated with controlling the motion of spring-loaded latch bolt 13, the end of latch bolt 13 is moveably positioned through opening 9 in base portion 12. Latch bolt 13 translates in an axial direction between an extended position (see
A compression spring 24 is mounted between a boss 26 extending from the interior surface of base portion 12 (see also
An electrically operated actuator assembly is configured to lock, unlock and move latch bolt 13 against the bias of spring 24. The electrically operated actuator assembly generally includes an electric motor 22, a reduction gear system 23, an output cam 30, and a drive cam 33. In the illustrated embodiment, the output shaft (not shown) of the motor 22 is engaged to the reduction gear system 23 such that it provides a motive force or an input torque to the reduction gear system 23 when the motor 22 is energized. The motive force or input torque provided by the motor 22 is rotational and imparts rotation to the gear wheels (not shown) of the reduction gear system 23. The operation of a reduction gear system and the interconnection between a reduction gear system and a motor output shaft are well known and therefore are not discussed in detail. Accordingly, the output shaft of the motor rotates in response to the motor being energized and in turn causes an output shaft (not shown) of the reduction gear system 23 to rotate. By a reduction gear system it is meant that the output shaft of the motor must rotate several times or more for each rotation of the output shaft of the reduction gear system 23. This arrangement increases the torque output of the motor, and, consequently, the size of the motor 22 required for the proper operation of the latch bolt 13 may be decreased. The reduction gear system 23 may be omitted if so desired.
Referring now to
The output shaft of motor 22, reduction gear system 23, output cam 30 and drive cam 33 may be referred to herein as an output shaft arrangement.
As shown in
Output cam 30 includes sloping cam surfaces at its distal end. More particularly, a pair of ramps 40 at the distal end that each extend along a spiral path for about 150 degrees about the central axis of output cam 30. Each ramp 40 includes a cam surface arranged helically about the axis of rotation of output cam 30. A flat horizontal landing surface, which extends perpendicularly to the axis of rotation of output cam 30, is formed at the apex 43 of each ramp 40. Another flat horizontal landing surface, which extends perpendicularly to the axis of rotation of output cam 30, is formed at the base 45 of each ramp 40. A flat vertical surface 41, which extends parallel to the axis of rotation of output cam 30, connects apex 43 of one ramp 40 with base 45 of the other ramp 40. The angled surfaces of ramps 40 both rise in the same direction of rotation.
Referring now to
In the extended position of latch bolt 13 shown in
Drive cam 33 has a circular receptacle 48 (see
The drive cam 33 has two protrusions 55A and 55B (referred to either collectively or individually as protrusion(s) 55), in the form of wings, that extend outwardly in a radial direction from apexes 49 of drive cam 33. Protrusions 55 are spaced apart along the circumference of drive cam 33 by about 180 degrees. As noted above, drive cam 33 is capable of translating to a limited extent as well as rotating to a limited extent. Protrusions 55 are configured to limit both rotation and translation, as is described hereinafter, in order to selectively lock and unlock latch bolt 13.
As explained above, latch assembly 10 includes a spring-loaded lever 15 that is configured to bias the door (not shown) and latch assembly 10 away from the door opening (not shown) with which the door engages. Lever 15 includes a torsion spring 64 that is configured to bias the lever 15 in the direction of the arrow shown in
Latch assembly 10 is configured to monitor the position of lever 15 to determine whether or not the door is open or closed. More particularly, lever 15 includes an embedded rare earth magnet 65 that communicates with a reed switch 66 on PCB 18, as shown in
Latch assembly 10 includes a controller 68 mounted to PCB 18 that communicates with, at least, motor 22, reed switch 66, position sensor 63 and motor control sensor 38 to monitor and control operation of latch assembly 10.
PCB 18 also includes a receiver and transmitter that is connected to controller 68 to enable wireless communications to and from latch assembly 10. By way of example, controller 68 can transmit information relating to the locked, unlocked, latched and unlatched states of latch assembly 10, as well as the open and closed states of the door that is connected to latch assembly 10 based upon the various states of the sensors and switches 38, 63 and 66. Using this information, a user can determine whether the door is open or closed or the user can determine whether the latch assembly 10 is unlatched, locked or unlocked without having to visually inspect latch assembly 10 on site. Latch assembly 10 may also be remotely controlled using the receiver and transmitter. For example, a user may remotely instruct latch assembly 10 to open the door or unlock or lock the latch assembly 10. Communications to and from latch assembly 10 may be wireless, wired, web based, and/or cloud based, or any other conventional communication method known to those skilled in the art.
Described hereinafter is one exemplary method for operating latch assembly 10 according to
In the locked state shown in
In the locked state of latch assembly 10 shown in
Drive cam 33 cannot yet translate in an axial direction as output cam 30 is rotated due to the engagement between protrusions 55A and 55B of output cam 33 and stopping surfaces 59 and 62, respectively. Once drive cam 33 initially rotates by 45 degrees in the clockwise direction, however, protrusions 55A and 55B of output cam 33 radially separate from stopping surfaces 59 and 62, respectively. In other words, protrusions 55A and 55B of drive cam 33 move from the locked position shown in
Upon reaching the unlocked position shown in
After drive cam 33 has rotated by 45 degrees in the clockwise direction, reed switch 66 is still ‘ON’ because it senses the presence of lever 15. The lever 15 has not yet moved from the extended position shown in
Motor 22 does not pause once latch bolt 13 is unlocked. Motor 22 continues to rotate output cam 30 in a clockwise direction until latch bolt 13 is unlatched. Controller 68 continues to transmit a signal to motor 22 to rotate output cam 30 in a clockwise direction by an additional 135 degrees (i.e., for a total of 180 degrees of clockwise rotation) causing latch assembly 10 to move from the unlocked state depicted in
More particularly, as output cam 30 is rotated in a clockwise direction by an additional 135 degrees, ramp surface 40 of output cam 30 rides along ramp surface 44 of drive cam 33 causing drive cam 33 (which is incapable of further rotation in the clockwise direction, as noted above) to translate in the distal direction until apex 49 of each ramp 44 bears on the apex 43 of each ramp 40 and the sloping surfaces of the ramps 40 and 44 are completely disengaged from each other, as shown in
Once bolt portion 20 of latch bolt 13 withdraws from opening 9, the spring-loaded lever 15 automatically springs forward under the force of spring 64 to move the door (to which latch assembly 10 is fixedly attached) away from the door opening. In other words, lever 15 moves from the position shown in
As output cam 30 is rotated in a clockwise direction by the additional 135 degrees, the motor control sensor 38 returns to the ‘ON’ state once the sensor 38 senses the leading edge of protrusion 36B, as shown in
Once latch assembly 10 is in the unlatched state, reed switch 66 is ‘OFF’ because it no longer senses the presence of magnet 65 embedded in lever 15, as shown in
Now that the door is open, latch bolt 13 must be returned to an unlocked and extended state shown in
In the course of clockwise rotation of the output cam 30, apex 43 of cam 30 slides along apex 49 of cam 33 until the vertical surface 41 of cam 30 registers in a circumferential direction with vertical surface 46 of cam 33. It should be understood that, at this stage, drive cam 33 does not rotate. Once surfaces 41 and 46 of cams 30 and 33 register with one another, spring 24 causes latch bolt 13 and its cage 21 to translate drive cam 33 in a proximal direction until ramps 40 and 44 of cams 30 and 33 reengage with each other, respectively, as shown in
Reed switch 66 remains ‘OFF’ because it does not sense the presence of magnet 65 embedded in lever 15, as shown in
As an alternative to the 2 second time delay described above, a user could be required to reset the latch assembly 10.
The end-user then manually closes the door to which the latch assembly 10 is attached. As bolt portion 20 slides along the door opening, the latch bolt 13 and drive cam 33 initially translate in the distal direction against the force of spring 24. At that moment, position sensor 63 briefly returns to the ‘ON’ state because it senses the presence of cage surface 61, which is now in the retracted position shown in
As the end-user closes the door, the lever 15 comes into contact with the door opening and the end-user pushes the door closed against the spring force of lever 15. Once the door is closed, lever 15 returns to the extended state shown in
Now that the door is latched closed, there exists the potential that an unauthorized user could tamper with latch assembly 10 by manually moving the bolt portion 20 to the unlatched state shown in
Starting from the closed state shown in
As an alternative to the above-described time delay, a user could instruct latch assembly 10 to lock.
Counterclockwise rotation of the drive cam 33 causes the protrusions 55A and 55B of output cam 33 to bear on stopping surfaces 59 and 62, respectively, as shown in
In the locked configuration shown in
In the locked configuration of latch assembly 10 shown in
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.
This application is related to, and claims the benefit of priority of, U.S. Provisional Application No. 62/295,719, entitled ELECTROMECHANICAL LOCKING LATCH, filed on 16 Feb. 2016, the contents of which are incorporated herein by reference in their entirety for all purposes.
Filing Document | Filing Date | Country | Kind |
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PCT/US2017/017910 | 2/15/2017 | WO | 00 |
Number | Date | Country | |
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62295719 | Feb 2016 | US |