Electromechanical keeper

Abstract

An electromechanical keeper is disclosed that includes a base plate adapted for being mounted to a flat surface, a catch member pivotally supported by the base plate, and a solenoid having a solenoid shaft. The catch member is adapted to engage the pawl of a latch when the catch member is the closed position and the catch member is not engageable by the latch pawl when the catch member is in the open position. The solenoid shaft engages a cavity or bore in the catch member to retain the catch member in the closed position. The solenoid shaft disengages from the cavity or bore in the catch member to allow the catch member to rotate to the open position when the solenoid is energized.

Description

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to an electromechanical keeper for use with a slam-action latch.

[0004] 2. Description of the Prior Art

[0005] Slam-action latches are used to releasably secure panels, covers, doors, electronic modules, and the like to other structures such as compartments, containers, door frames, other panels, frames, racks, etc. Slam-action latch as used herein refers to any type of latch having a pawl biased toward the closed or extended position. When, for example, a door to which the slam-action latch is mounted is slammed shut, the pawl is automatically moved to the retracted or open position by contact with a keeper or doorframe to allow the door to move to the fully closed position. Once the door is in the fully closed position the pawl returns to the closed or extended position to engage a keeper or door frame and thereby secure the door in the fully closed position. Hence the term slam-action latch.

[0006] Although keepers for use with slam-action latches are known in the art, none offers the advantages of the present invention. The advantages of the present invention will be apparent from the attached description and drawings.

SUMMARY OF THE INVENTION

[0007] The present invention is directed to an electromechanical keeper for use with a slam-action latch. Furthermore, the electromechanical keeper of the present invention is adapted to be surface-mountable such that it can be mounted to the surface of a doorframe without requiring a recess in the doorframe and with little or no preparation of the surface to which the electromechanical keeper of the present invention is to be mounted.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG. 1 is an environmental view showing a door having a slam-action latch mounted thereto and a doorframe with the electromechanical keeper of the present invention installed thereto, with the door being in the closed position and the electromagnetic keeper being in the closed configuration.

[0009] FIG. 2 is a perspective view showing the electromechanical keeper of the present invention in isolation.

[0010] FIGS. 3-8 are different views of the protective cover of the electromechanical keeper of the present invention.

[0011] FIGS. 9-14 are different views of the base plate of the electromechanical keeper of the present invention.

[0012] FIGS. 15-21 are different views of the catch member of the electromechanical keeper of the present invention.

[0013] FIGS. 22-25 are different views of the solenoid shaft of the electromechanical keeper of the present invention.

[0014] FIGS. 26-32 are different views of the electromechanical keeper of the present invention with the protective cover removed, with the solenoid shaft in the closed position, and with the catch member in the closed position.

[0015] FIGS. 33-39 are different views of the electromechanical keeper of the present invention with the protective cover removed, with the solenoid shaft in the open position, and with the catch member in the closed position.

[0016] FIG. 40 is an environmental view showing a door having a slam-action latch mounted thereto and a doorframe with the electromechanical keeper of the present invention installed thereto, with the door being opened and the electromagnetic keeper being in the open configuration.

[0017] FIGS. 41-47 are different views of the electromechanical keeper of the present invention with the protective cover removed, with the solenoid shaft in the open position, and with the catch member in the open position.

[0018] FIG. 48 is a schematic view of a circuit board and micro-switch that can be used with the electromechanical keeper of the present invention.

[0019] FIG. 49 is a perspective view showing an alternative embodiment of the electromechanical keeper of the present invention having a modified catch member.

[0020] FIG. 50 is an exploded view showing an alternative embodiment of the electromechanical keeper of the present invention having a modified catch member.

[0021] FIG. 51 is a perspective view showing an alternative embodiment of the electromechanical keeper of the present invention having an elongated catch member.

[0022] FIG. 52 is an exploded view showing an alternative embodiment of the electromechanical keeper of the present invention having an elongated catch member.

[0023] FIG. 53 is a perspective view showing an alternative embodiment of the electromechanical keeper of the present invention having an L-shaped catch member.

[0024] FIG. 54 is an exploded view showing an alternative embodiment of the electromechanical keeper of the present invention having an L-shaped catch member.

[0025] Similar reference characters denote corresponding features consistently throughout the attached drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Slam-action latches are latches that have pawls that automatically move to allow closing of a door or the like and that automatically move to a closed position behind a keeper or the like to secure the door in the closed condition. All these actions are accomplished as a result of slamming the door shut, hence the term “slam-action” latch. Examples of slam-action latches are disclosed in U.S. Pat. No. 4,978,152, the entire disclosure of which is incorporated herein by reference.

[0027] In the illustrative installation shown in the figures, the present invention is an electromechanical keeper 100 for use with a slam-action latch 102. The slam-action latch 102 is installed to the door 104 and the keeper 100 is installed to the doorframe 106. The keeper 100 includes a solenoid 112, a catch member 108, a base plate 114, a compression spring 116, a torsion spring 118 and a pivot pin 120. The catch member 108 is roughly in the shape of a rectangular parallelepiped having an elongated cylinder joined to one of its longer sides with the longitudinal axes of the rectangular parallelepiped and the elongated cylinder being parallel. The rectangular parallelepiped forms the pawl-engaging portion 109 of the catch member 108. In the closed position, the catch 108 interferes with the latch pawl 110, causing the latch pawl 110 to automatically move to allow closing of the door and to automatically move to a closed position behind the pawl-engaging portion 109, as the door 104 is slammed shut. Thus, the door can be secured in the closed position.

[0028] The portion 111 of the catch member 108 that is formed by the elongated cylinder has a longitudinal bore 131. The base plate 114 has a pair of pillars 132 and 134 that are spaced apart from one another. Each of the pillars 132 and 134 has a first bore 136 and 138, respectively. The bores 136 and 138 are in alignment with one another. The catch member 108 fits between the pillars 132 and 134 such that the bore 131 is in alignment with the bores 136 and 138. The pivot pin 120 is positioned through the bore 131 with its ends supported by the bores 136 and 138 such that the pivot pin 120 pivotally supports the catch member 108. The portion 111 of the catch member 108 is longer than the portion 109 of the catch member 108, thereby forming the cylindrical projection 140. The projection 140 is designed to accommodate the torsion spring 118, such that the coils of the torsion spring 118 are positioned around the projection 140. One arm 142 of the torsion spring 118 is positioned in a notch 144 of the catch member 108. The second arm 146 of the torsion spring 118 is positioned in the angle between the pillar 134 and the flat plate portion 148 of the base plate 114. The torsion spring 118 biases the catch member 108 toward the closed position shown in FIGS. 1, 2, and 26-39, such that the catch member 108 tends to return to the closed position whenever the catch member is displaced toward the open position and then released.

[0029] The catch member 108 also has a second projection 150 that abuts the pillar 132 when the catch member 108 is in the closed position. The interference between the projection 150 and the pillar 132 prevents the catch member 108 from over-rotating or overshooting the closed position as the catch member 108 rotates from the open position toward the closed position.

[0030] The pillar 132 has a second bore 152 that is parallel to, but spaced apart from, the first bore 136. The bore 152 is in alignment with a cavity or bore 124 in the catch member 108 when the catch member 108 is in the closed position.

[0031] The base plate 114 includes a structure 156 that is adapted for attachment or mounting of the solenoid 112 to the base plate 114. In the illustrated embodiment the mounting structure 156 includes a pair of parallel flanges 158 and 160 that project perpendicularly from the surface of the flat plate portion 148 of the base plate 114. The mounting structure 156 also includes a raised platform 162 positioned between the flanges 158 and 160.

[0032] The solenoid 112 includes a solenoid body 154, that houses the magnetic coils of the solenoid 112, and a solenoid shaft 122 that can reciprocate linearly relative to the solenoid body 154. The operation of the solenoid 112 is well known and is not discussed herein in detail. When the solenoid 112 is energized the solenoid shaft 122 linearly moves relative to the solenoid body 154 from an extended position to a retracted position. The solenoid shaft 122 includes an annular flange 164. The compression spring 116 is provided intermediate the flange 164 and the solenoid body 154 and acts to bias the solenoid shaft 122 toward the extended position.

[0033] The solenoid shaft 122 may be of one-piece construction or the shaft 122 may be built up from two or more pieces that are joined together so that they move as a single unit in operation.

[0034] The solenoid body 154 is positioned between the flanges 158 and 160 and securely attached to the base plate 114 such that the solenoid body 154 remains securely in place relative to the base plate 114 during operation of the electromechanical keeper 100. With the solenoid body 154 secured to the base plate 114, the solenoid shaft 122 will be in alignment with the bore 152. Furthermore, the solenoid shaft 122 will be in alignment with the cavity 124 when the catch member 108 is in the closed position.

[0035] The extended and retracted positions of the solenoid shaft 122 correspond to the open and closed positions of the solenoid shaft 122, respectively. When the catch member 108 is in the closed position and the solenoid shaft 122 is in the closed position, the solenoid shaft 122 engages cavity 124 and thereby prevents any rotational or pivotal movement of the catch member 108. When the solenoid 112 is energized the solenoid shaft 122 is retracted to the open or retracted position. The solenoid shaft 122 is completely withdrawn from the cavity 124 when the solenoid shaft 122 is in the open position, and the catch member 108 can rotate toward the open position of the catch member 108 that is illustrated in FIGS. 40-47 if the force due to the torsion spring 118 is overcome.

[0036] The catch member 108 also has an extension 174 that has a surface that is flush with the opening of the cavity 124. The extension 174 functions to keep the solenoid shaft 122 in the retracted or open position when the catch member 108 is out of its closed position. This arrangement prevents the solenoid shaft 122 from moving to its closed or extended position before the catch member 108 is back in its closed position. Thus the extension 174 prevents the solenoid shaft 122 from interfering with the pivotal movement of the catch member 108 back to its closed position.

[0037] In the illustrated embodiment, the electromechanical keeper 100 is provided with an RJ12 receptacle 166 for the connection of the power and/or control signal lines using a matching RJ12 jack (similar to a telephone jack and not shown). The appropriate conductors within the receptacle 166 are connected to the solenoid 112 by wires (not shown) to thereby provide power and/or control signals to the solenoid 112. The receptacle 166 is attached to the flat plate portion 148 of the base plate 114 with the solenoid body 154 positioned intermediate the receptacle 166 and the pillar 132.

[0038] The base plate 114 is adapted to be surface-mountable to any flat surface with little or no preparation of the surface and without a need to provide a recess or cavity in the surface. For example, the base plate 114 can be mounted to the underlying surface by using adhesives, by welding, by soldering or brazing, or by using fasteners such as screws, nuts and bolts, or rivets. In the illustrated embodiment, the flat plate portion 148 of the base plate 114 is provided with mounting holes 168. In the illustrated embodiment, the base plate 114 is mounted to the flat inner side 170 of the doorframe 106. The only surface preparation required is to drill holes in the side 170 of doorframe 106 that correspond to the mounting holes 168. Some of the mounting holes 168 are elongated or are in the form of slots to allow some degree of positional adjustment for the base plate 114 once the holes in the side 170 of the doorframe 106 are drilled.

[0039] In addition, the electromechanical keeper 100 is provided with a protective cover 172 that is best illustrated in FIGS. 3-8. The protective cover 172 covers the receptacle 166, the solenoid 112, the electrical circuitry between the receptacle 166 and the solenoid 112, and the gap between the solenoid body 154 and the pillar 132. The protective cover 172 prevents corrosion and foreign matter from interfering with the operation of the electromechanical keeper 100. The protective cover 172 can be secured in place using a variety of means such as adhesives, welding, fasteners, or by providing a snap-fit between the protective cover 172 and the base plate 114.

[0040] The operation of the electromechanical keeper 100 will now be described with the door 104 closed and with the solenoid 112 not energized. The electromechanical keeper 100 will be mounted to the doorframe 106 as illustrated in FIGS. 1 and 2. The catch member 108 will initially be in the closed position because the torsion spring 118 biases the catch member 108 to the closed position. When the solenoid 112 is not energized, the compression spring 116 biases the solenoid shaft 122 into engagement with the cavity 124 of the catch member 108 and the solenoid shaft 122 will in fact extend into the cavity 124. In this configuration the catch member 108 is prevented from rotating or pivoting out of its closed position and the catch member 108 will behave essentially like a fixed keeper. If a user has a key to the latch 102, the user can operate the latch 102 and open the door 104 in the conventional manner. Once the door is open, the user can also close the door in the conventional manner. Because the solenoid shaft 122 extends into the cavity 124, the catch member 108 will remain in its closed position as the door 104 is closed. In the closed position, the catch 108 interferes with the latch pawl 110, causing the latch pawl 110 to automatically move to a retracted position to allow closing of the door. Once the door is fully closed, the latch pawl 110 automatically moves to the extended or closed position behind the pawl-engaging portion 109 of the catch member 108, as illustrated in FIG. 1, to thereby secure the door 104 in the closed position. The door 104 will then be locked and cannot be opened without operating the latch 102 or energizing the solenoid 112.

[0041] To unlock the door 104 electrically, the solenoid 112 is energized, which causes the solenoid shaft 122 to be retracted from the cavity 124. The catch member 108 can now rotate or pivot about pin 120. Even with the solenoid shaft 122 retracted, due to the force of the torsion spring 118, the catch member 108 will not rotate to its open position and the door 104 will remain closed. However, if the door 104 is pulled with sufficient force to overcome the force of the torsion spring 118 while the solenoid 112 is energized, the catch member 108 will rotate out of engagement with the latch pawl 110 and the door will open. When the catch member 108 is rotated out of engagement with the latch pawl 110, the catch member 108 will be in the open position illustrated best in FIG. 40. After the door 104 is open, the force of the torsion spring 118 will reset the catch member 108 back to its closed position. Then when the solenoid 112 is no longer energized, i.e. when the power to the solenoid is cut off, the solenoid shaft 122 will slide back into the cavity 124 and will lock the catch member 108 in the closed position. The door 104 can then be slammed shut to once again cause the door to be secured or locked in the closed position as has previously been described.

[0042] In one illustrative embodiment, the solenoid 112 is operated with a 25% duty cycle such that the solenoid is energized for 10 seconds to allow the door to be opened and then the solenoid is not energized again within the next 30 seconds. This method of operation prevents the solenoid 112 from overheating.

[0043] Referring to FIG. 48, a schematic view of a circuit board and micro-switch that can be used with the electromechanical keeper of the present invention can be seen. The micro-switch 180 is positioned such that it can be actuated by the solenoid shaft 122 when it reaches a fully open or retracted position. The micro-switch 180 communicates with the circuit board 182 that is supported by the base plate 114. The circuit board 182 also communicates with the solenoid 112 and the receptacle 166. The power supply to the solenoid is controlled by the circuit board 182 such that overheating of the solenoid is prevented. When the micro-switch 180 is actuated by the solenoid shaft 122 reaching the fully open or retracted position, a signal is generated to the circuit board 182 that indicates the time when energizing of the solenoid was initiated. The circuit board 182 can then control the power supplied to the solenoid 112 such that the solenoid is energized for a first predetermined period of time, e.g. 10 seconds, to allow the door to be opened and then the solenoid is not energized again within a following second predetermined period of time, e.g. the next 30 seconds, in order to prevent over heating of the solenoid.

[0044] Referring to FIGS. 49 and 50, an alternative embodiment of the electromechanical keeper of the present invention having a modified catch member can be seen. This embodiment 200 is essentially identical to the electromagnetic keeper 100 except for the modified catch member 208. The modified catch member 208 is essentially similar to the catch member 108 except that the catch member 208 is provided with the shelf or step 284. The shelf 284 projects outward substantially perpendicularly from the pawl-engaging portion 209 of the catch member 208. When the catch member 208 is in the open position, the shelf 284 is positioned such that the shelf 284 is in the approximate position of the pawl-engaging portion 209 of the catch member 208 in the closed position. Thus, when the catch member 208 is recessed within an opening in the doorframe, the shelf 284 blocks efforts to tamper with the catch member 208 by, for example, jamming or propping catch member 208 in the open position by inserting a foreign object in to the opening in the doorframe. In addition, the shelf 284 can aid in returning the catch member 208 to its closed position, for example, when friction between the catch member 208 and the solenoid shaft 122 is too excessive for the torsion spring 118 to overcome. This result is achieved by the impact of the pawl 110 of the latch 102 on the shelf 284 as the door is closing while the catch member 208 is in the open position.

[0045] Referring to FIGS. 51 and 52, an alternative embodiment of the electromechanical keeper of the present invention having an elongated catch member can be seen. This embodiment 300 is essentially identical to the electromagnetic keeper 200 except for the modified catch member 308. The modified catch member 308 is essentially similar to the catch member 208 except that the catch member 308 is provided with an elongated catch portion 386 having a hook-like end portion 388. The elongated catch portion 386 is attached to the approximately parallelepiped body portion 309 of the catch member 308 such that the elongated catch portion 386 extends parallel to the base plate 114 and the pivot shaft 120 is positioned intermediate the base plate 114 and the hook-like end portion 388, when the catch member 308 is in the closed position. The latch pawl 110 catches the hook-like end portion 388 to secure the door 104 in the closed position, when the catch member 308 is in the closed position. The design of the catch member 308 allows the electromechanical keeper to be mounted farther from the door 104 on the surface 170 of the doorframe 106, should this be necessary because of the geometry of the doorframe 106 or the door 104.

[0046] Referring to FIGS. 53 and 54, an alternative embodiment of the electromechanical keeper of the present invention having an L-shaped catch member can be seen. This embodiment 400 is essentially identical to the electromagnetic keeper 300 except for the modified catch member 408. The modified catch member 408 is essentially similar to the catch member 308 except that the catch member 408 is provided with an elongated catch portion 486 having a bend so as to have an L-shaped profile. The elongated catch portion 486 has a hook-like end portion 488 that functions similarly to the hook-like end portion 388. The elongated catch portion 486 is attached to the approximately parallelepiped body portion 409 of the catch member 408 such that the elongated catch portion 486 initially extends parallel to the base plate 114 and the bends at about a right angle in a direction toward the plane of the base plate 114. The pivot shaft 120 is positioned intermediate the base plate 114 and the attachment of the elongated catch portion 486 to the approximately parallelepiped body portion 409. The latch pawl 110 catches the hook-like end portion 488 to secure the door 104 in the closed position, when the catch member 408 is in the closed position illustrated in FIG. 53. The design of the catch member 408 allows the electromechanical keeper 400 to be mounted behind the doorframe 106 to the surface 171 of the doorframe 106, should this be necessary because of the geometry of the doorframe 106 or the door 104.

[0047] It is to be understood that the present invention is not limited to the embodiments disclosed above, but includes any and all embodiments within the scope of the appended claims.

Claims

1. An electromechanical keeper comprising: a base plate adapted for being mounted to a flat surface; a catch member pivotally supported by said base plate, said catch member being movable between open and closed positions, said catch member being adapted to engage a latch pawl of a latch when said catch member is in said closed position and said catch member not being engageable by the latch pawl when said catch member is in said open position, said catch member having a cavity or bore; and a solenoid supported by said base plate, said solenoid having a solenoid shaft that is movable from a closed position to an open position responsive to said solenoid being energized, said solenoid shaft engaging said cavity or bore in said catch member to thereby retain said catch member in said closed position when said solenoid shaft is in said closed position, said solenoid shaft being disengaged from said cavity or bore in said catch member such that said catch member is free to move from said closed position of said catch member to said open position of said catch member when said solenoid shaft is in said open position of said solenoid shaft.