Abstract:
The present invention is directed to a latch that includes a housing, a pawl pivotally supported by the housing and movable between a latched position and an unlatched position, a spring biasing the pawl toward the unlatched position, and a locking member being rotationally movable about an axis of rotation between an open position and a locked position. The locking member interferes with the movement of the pawl such that the pawl is maintained in the latched position when the pawl is in the latched position and the locking member is in the locked position. The locking member allows the pawl to move to the unlatched position when the locking member is in the open position. The latch may further include a motor housing, a lockplug, a lockplug member, at least one roller switch, at least one gearbox, and a motor.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]    This utility patent application is based on U.S. provisional patent application No. 60/216,752, filed Jul. 7, 2000. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention is a latch for actuation with both an electric motor and manually.  
           [0004]    2. Description of the Related Art  
           [0005]    Latch assemblies are relied on in many applications for securing items, such as panels, together. For example, containers, cabinets, closets, compartments and the like may be secured with a latch. An important use for latches is in the automotive field, where there is a desire and need to access automotive compartments, such as, for example, the trunk or passenger compartments of vehicles, as well as interior compartments such as a glove box.  
           [0006]    Various latches for panel closures have been employed where one of the panels such as a swinging door or the like is to be fastened or secured to a stationary panel or compartment body. The prior art devices generally utilize a locking member which is spring-loaded externally by one or more separately provided torsion springs. For example, some prior art devices rely upon a lock which comprises rigid metal parts and requires additional biasing members for operation of the assembly. It has been increasingly more important and desirable to provide remote features for operation of latch mechanisms which permits a user to operate the latch from a location remote of that at which the latch is installed. For example, automobile latches often rely on the use of remote devices to open and close door locks, for example, using infrared, radio, or other wireless transmission modes. In addition, vehicle trunks often are provided so that they can be unlocked by remote means to permit the raising or opening of a panel.  
           [0007]    In furnishing remote latching mechanisms, it must be taken into account that in some instances remote means may have failures, such as, for example, due to a loss of power supply (especially where electronic circuitry is employed). It is therefore also desirable to provide additional or secondary latching capabilities in order that the latch can be locked or opened manually, should the remote mechanism fail. In some instances, capped openings are provided in the vicinity of the latch which can permit a user to access the latch to open it should the remote mechanism not be operable. However, where security is concerned, it is not practical to provide an easy means for gaining an ability to open a latch. In these instances, complex mechanisms have been employed.  
           [0008]    It is desirable to provide a latch which can be utilized both, by a remote locking mechanism and a key operated mechanism, and furthermore, where both the remote and the key operation can be used alternately as desired by the user. That is, it is desirable to have a latch with a locking capability where either a remote locking mechanism or a manual (key type) mechanism can be used to lock or unlock the latch, regardless of which one had previously been used.  
           [0009]    The present invention provides a novel ratcheting pawl latch with the ability to lock and unlock the latch with remote and key operated mechanisms.  
         SUMMARY OF THE INVENTION  
         [0010]    The present invention is a latch that may be operated either by an electric motor, possibly remotely, or manually. The latch includes a lockplug housing, a motor housing, a lockplug, a lockplug driver, a locking disk, a pawl, and a pair of roller switches.  
           [0011]    The pawl includes a pair of arms and a locking disk engagement tooth. The pawl pivots between a latched and unlatched position, and is spring-biased towards its unlatched position. The pawl is dimensioned and configured to secure a wire keeper between its two arms.  
           [0012]    The locking disk is pivotally secured between the lockplug housing and the motor housing. The locking disk defines a bearing surface around its circumference, which further defines a window dimensioned and configured to permit passage of the pawl, and a pair of cutouts. The locking disk pivots between a locked position and an open position, defining an unlocked range of positions therebetween. The locking disk is spring-biased away from the open position, but is not spring-biased in either the locked position or the unlocked range of positions. In the locked and unlocked positions, the edge of the locking disk abuts the locking disk engagement tooth of the pawl, thereby securing the pawl in its latched position. When the locking disk is rotated to the unlocked position, the window is aligned with the pawl, allowing the pawl to rotate to its unlatched position. The locking disk will then abut the pawl&#39;s locking disk engagement tooth, preventing the locking disk from rotating out of the locked position.  
           [0013]    One side of the locking disk engages a gearbox, which in turn engages a motor. The motor is preferably a 12-volt DC motor, but is not limited to this type. The DC motor may be controlled by any of several means, including a programmable logic controller, a dashboard mounted switch, and/or a remote switch. The opposite side of the locking disk engages the lockplug driver.  
           [0014]    The lockplug and lockplug driver turn as a single unit within the lockplug housing. The lockplug is spring-biased towards a central position. The lockplug driver engages the locking disk by means of a pin projecting from the locking disk into a slot in the lockplug driver. The slot extends for 90° around the lockplug driver. Therefore, the lockplug must be rotated 45° in either direction before engaging the locking disk. Likewise, when the motor rotates the locking disk, the locking disk is free to rotate 45° before engaging the lockplug driver. This is necessary because a force applied to rotate the lockplug will rotate the DC motor as well, but a force applied through the DC motor will have no way to rotate the lockplug.  
           [0015]    The latch includes a pair of roller switches between the motor housing and lockplug housing. Each roller switch includes a cantilever with a roller end abutting the bearing surface of the locking disk. Depressing the cantilever closes an electrical circuit. When the roller abuts a cutout in the locking disk, the cantilever is extended, opening the circuit. Likewise, when the roller abuts the other portions of the disk&#39;s bearing surface, the cantilever is depressed. One cutout corresponds to the latch&#39;s locked position, and the other corresponds to the latch&#39;s open position. Therefore, the first of the two roller switches will be open when the latch is locked, and the second of the two roller switches will be open when the latch is open. The combined state of the two latches therefore indicates whether the latch is locked, unlocked, or open. This signal can be directed to a programmable logic controller (PLC), which, given the current state of the latch, and the desired state of the latch from a remote controller, will turn the motor the proper amount to bring the latch into the desired state. For example, if the latch is unlocked (both roller switches closed) and the user switches the latch to open, the PLC will rotate the motor until the second roller switch engages the corresponding cutout in the locking disk and opens. The PLC will then receive a signal that the latch is open, and stop rotating the motor.  
           [0016]    It is a principal object of the present invention to provide a novel latch assembly which is selectively engagable with a keeper member, and includes a spring locking member which is spring-loaded with its own spring force for engaging and releasing a pawl from a keeper member when a handle is actuated.  
           [0017]    It is another object of the present invention to provide a locking member which is comprised of spring steel or plastic.  
           [0018]    It is another object of the present invention to provide a latch assembly with a locking component which can be operated with a key or other operator, such as radio, infrared, electronic or other means, which selectively engages the locking member against movement.  
           [0019]    It is another object of the present invention to provide a latch assembly with a locking mechanism which can be operated with a key or other operator, such as, a solenoid controller, where the key and solenoid control the same locking element but provide independent ways to lock and unlock the latch.  
           [0020]    These and other objects of the invention will become apparent through the following description and claims. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0021]    [0021]FIG. 1 is a perspective view of an electrically operated ratcheting pawl latch according to the present invention.  
         [0022]    [0022]FIG. 2 is a rear view of an electrically operated ratcheting pawl latch according to the present invention.  
         [0023]    [0023]FIG. 3 is a side view of an electrically operated ratcheting pawl latch according to the present invention.  
         [0024]    [0024]FIG. 4 is an exploded perspective view of an electrically operated ratcheting pawl latch according to the present invention.  
         [0025]    [0025]FIG. 5 is an exploded side view of an electrically operated ratcheting pawl latch according to the present invention.  
         [0026]    [0026]FIG. 6 is a perspective view of a lockplug housing for an electrically operated ratcheting pawl latch according to the present invention.  
         [0027]    [0027]FIG. 7 is a bottom view of a lockplug housing for an electrically operated ratcheting pawl latch according to the present invention.  
         [0028]    [0028]FIG. 8 is a rear view of a lockplug housing for an electrically operated ratcheting pawl latch according to the present invention.  
         [0029]    [0029]FIG. 9 is a perspective view of a motor housing for an electrically operated ratcheting pawl latch according to the present invention.  
         [0030]    [0030]FIG. 10 is a side view of a motor housing for an electrically operated ratcheting pawl latch according to the present invention.  
         [0031]    [0031]FIG. 11 is a rear view of a motor housing for an electrically operated ratcheting pawl latch according to the present invention.  
         [0032]    [0032]FIG. 12 is a perspective view of a lockplug for an electrically operated ratcheting pawl latch according to the present invention.  
         [0033]    [0033]FIG. 13 is a front view of a lockplug for an electrically operated ratcheting pawl latch according to the present invention.  
         [0034]    [0034]FIG. 14 is a side view of a lockplug for an electrically operated ratcheting pawl latch according to the present invention.  
         [0035]    [0035]FIG. 15 is a perspective view of a lockplug driver for an electrically operated ratcheting pawl latch according to the present invention.  
         [0036]    [0036]FIG. 16 is a front view of a lockplug driver for an electrically operated ratcheting pawl latch according to the present invention.  
         [0037]    [0037]FIG. 17 is a rear view of a lockplug driver for an electrically operated ratcheting pawl latch according to the present invention.  
         [0038]    [0038]FIG. 18 is a perspective view of a locking disk for an electrically operated ratcheting pawl latch according to the present invention.  
         [0039]    [0039]FIG. 19 is a side view of a locking disk for an electrically operated ratcheting pawl latch according to the present invention.  
         [0040]    [0040]FIG. 20 is a rear view of a locking disk for an electrically operated ratcheting pawl latch according to the present invention.  
         [0041]    [0041]FIG. 21 is a perspective view of a pawl for an electrically operated ratcheting pawl latch according to the present invention.  
         [0042]    [0042]FIG. 22 is a perspective view of a pawl spring for an electrically operated ratcheting pawl latch according to the present invention.  
         [0043]    [0043]FIG. 23 is a perspective view of a roller switch for an electrically operated ratcheting pawl latch according to the present invention.  
         [0044]    [0044]FIG. 24 is a perspective view of a sungear for an electrically operated ratcheting paw latch according to the present invention.  
         [0045]    [0045]FIG. 25 is a perspective view of a torsion spring for an electrically operated ratcheting pawl latch according to the present invention.  
         [0046]    [0046]FIG. 26 is a perspective view of a gearbox for an electrically operated ratcheting paw latch according to the present invention.  
         [0047]    [0047]FIG. 27 is a perspective view of a motor for an electrically operated ratcheting pawl latch according to the present invention.  
         [0048]    [0048]FIG. 28 is a perspective view of an electrically operated ratcheting pawl latch according to the present invention, showing the latch locked.  
         [0049]    [0049]FIG. 29 is a perspective view of an electrically operated ratcheting pawl latch according to the present invention, showing the latch unlocked.  
         [0050]    [0050]FIG. 30 is a perspective view of an electrically operated ratcheting pawl latch according to the present invention, showing the latch open. 
     
    
       [0051]    Like reference numbers denote like elements throughout the drawings.  
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0052]    The invention is an electrically operated ratcheting pawl latch. Referring to FIGS.  1 - 5 , the latch  10  includes a lockplug housing  50 , a motor housing  100 , a lockplug  150 , a lockplug driver  200 , a locking disk  250 , a pawl  300 , a pair of roller switches  350 , at least one gearbox  400 , and a motor  450 .  
         [0053]    Referring to FIGS.  6 - 8 , the lockplug housing  50  is illustrated. The lockplug housing  50  includes a front  52 , a bottom  54 , a pair of sides  56 ,  57 , and a top  58 . The front  52  defines a channel  60  dimensioned and configured to receive a lockplug driver  200  (described below) and a cylinder  62  dimensioned and configured to receive a lockplug  150 . The cylinder  62  defines a recess  64  for receiving a plurality of locking wafers of the lockplug  150  (described below). A pawl nest  66  protrudes from the bottom  54 , and a window  68 , dimensioned and configured to receive a pawl  300  (described below), is defined in that portion of the bottom  54  within the pawl nest  66 . The pawl nest  66  preferably includes a pair of coaxial apertures  67 . Referring specifically to FIG. 8, illustrating the rear or inside portion of the lockplug housing  50 , a locking disk wall  70  is illustrated surrounding the channel  60 . A lockplug torsion spring driving tooth  72  is defined within the channel  60 , adjacent to the cylinder  62 . A locking disk torsion spring tooth  74  is defined opposite the tooth  72 , adjacent to the cylinder  62  but outside the channel  60 . Adjacent to one side  56 , a plurality of risers  76  is positioned for retaining a pair of roller switches  350  (described below). The side  56  defines a pair of windows  78  for permitting access to the contacts on the roller switches  350 , best seen in FIG. 7. The lockplug housing  50  preferably includes a plurality of mounting holes  80  for securing the lockplug housing  50  to the motor housing  100 .  
         [0054]    The motor housing  100  is best illustrated in FIGS.  9 - 11 . The motor housing  100  includes a panel  102 , from which a rearward portion  104  extends. The rearward portion  104  defines a motor-containing portion  106  and a gearbox-containing portion  108 . The motor-containing portion  106  preferably includes a window  110  for passage of the electrical contacts to the motor  450 . The opposite side of the panel  102  includes a perimeter wall  112 , dimensioned and configured to contain the locking disk  250 . The motor housing  100  includes risers  114 , dimensioned and configured to secure the roller switches  350  in place. A guide slot  118  is defined around a 90° section of the perimeter wall  112 . The panel  102  preferably includes mounting holes  116  for securing the motor housing  100  to the lockplug housing  50 .  
         [0055]    A lockplug  150  is illustrated in FIGS.  12 - 14 . The lockplug  150  includes a key slot  152  within its front end  154 . The rear of lockplug  150  may include a peg  156 . A plurality of wafers  158  extends from slots  160  within the side wall  162  of lockplug  150 . When a key is inserted and engages tumblers  164 , the wafers  158  are retracted. Likewise, removing the key extends the wafers  158 . A retention wafer  166  is spring-biased outward from a slot  168  within the side wall  162 .  
         [0056]    A lockplug driver  200  is illustrated in FIGS.  15 - 17 . The lockplug driver  200  includes a cylinder  202 , dimensioned and configured to receive the lockplug  150 . The cylinder  202  includes a slot  204 , dimensioned and configured to receive the retention wafer  166 . The rear portion  206  includes an aperture  208 , dimensioned and configured to receive the lockplug&#39;s peg  156 . Opposite the cylinder  202 , the rear portion  206  also defines a central aperture  212 , and a channel  214 , extending for 90° around the aperture  212 . The aperture  212  is dimensioned and configured to engage a center post of the locking disk  250  (described below). The channel  214  is dimensioned and configured to engage a driver post on the locking disk  250 . A spring retaining tab  210  protrudes outward to one side of the cylinder  202 .  
         [0057]    The lockplug  150  is inserted into the lockplug driver  200  so that the retention wafer  166  engages the slot  204 , and the peg  156  engages the aperture  208 . In use, the lockplug  150  and lockplug driver  200  will rotate as a single unit, and will be biased towards the position wherein the wafers  158  will engage the recess  64 . The means for biasing the lockplug  150  and lockplug driver  200  is preferably a spring such as the spring  550  illustrated in FIG. 25.  
         [0058]    The locking disk  250  is best illustrated in FIGS.  18 - 20 . The locking disk  250  includes a central post  252  and a driver post  254  on its front face  256 . The front face  256  also defines a cavity  258 , dimensioned and configured to receive a spring and the locking disk torsion spring tooth  74  of the lockplug housing  50 . A spring retention feature  272  is also defined within the cavity  258 . The rear face  260  includes an aperture  262 , dimensioned and configured to receive a sungear  500  (illustrated without teeth in FIG. 24), and a deadstop lug  264 , dimensioned and configured to engage the slot  118  within the motor housing  100 . The locking disk&#39;s circumference  266  defines a bearing surface having a pair of cutouts  268 , and a window  270 , dimensioned and configured to receive the pawl  300 .  
         [0059]    The locking disk  250  is positioned immediately behind the lockplug driver  200 , with the central post  252  engaging the aperture  212 , and the driver post  254  engaging the slot  214 . In use, the locking disk  250  will pivot between an open position and a locked position, with an unlocked range of positions defined therebetween, and will be biased away from the open position. Preferred and suggested means for biasing the locking disk  250  away from the open position is the spring  550 .  
         [0060]    The pawl  300  is illustrated in FIG. 21. The pawl  300  includes a locking disk engaging tooth  302 , a first arm  304 , and a second arm  306 . The arms  304 ,  306  are substantially parallel and opposite the locking disk engaging tooth  302 . A slot  310  is defined between arms  304 ,  306 , and is dimensioned and configured to receive a wire keeper (not shown, and well-known). The pawl  300  also includes means for pivotally securing it within the latch  10 , with preferred and suggested means being pegs  308 , dimensioned and configured to mate within the apertures  67  within the pawl nest  66 . With the pawl  300  secured within the apertures  67 , the pawl  300  will pivot between a latched position and an unlatched position, and will be biased towards its unlatched position. Preferred and suggested means for biasing the pawl  300  towards its unlatched position are the spring  552 , illustrated in FIG. 22. The locking disk  250  will abut locking disk engaging tooth  302  of the pawl  300  when the locking disk  250  is in the locked or unlocked positions. In the open position of the locking disk  250 , the pawl  300  will be aligned with the window  270 .  
         [0061]    Located rearward of the locking disk  250  is at least one gearbox  400 , illustrated in FIG. 26, and a motor  450 , illustrated in FIG. 27. The gearbox  400  is preferably a planetary gearbox. The motor  450  is preferably a 12 volt DC motor. The motor  450  is located within the motor containing portion  106  of the motor housing  100 , and is powered through electrical contacts passing through the window  110 . The motor  450  is connected through a sungear  500  to the gearbox  400 , located within the gearbox containing portion  108  of the motor housing  100 . The gearbox  400  is connected to the locking disk  250  by a second sungear  500 , fitting within the aperture  262 .  
         [0062]    Referring to FIG. 23, a roller switch  350  is illustrated. Roller switch  350  includes a cantilever  352 , terminating in a roller  354 . A contact  356  is located beneath the cantilever  352 , so that depressing cantilever  352  closes an electrical circuit, and releasing cantilever  352  opens the circuit. Electrical contacts  358  allow connection of the roller switch  350  to an electrical circuit. Each of the two roller switches  350  is located adjacent to the locking disk  250 , so that the roller  354  abuts the locking disk&#39;s bearing surface  266 . The contacts  358  are adjacent to the windows  78 . Cantilever  352  is depressed unless the roller  354  has engaged one of the cutouts  268 . Therefore, the cantilever  352  of the roller switch  350   a  is released when the locking disk  250  is in the locked position, and the cantilever  352  of the roller switch  350   b  is released when the locking disk  250  is in the open position. Both cantilevers  352  are depressed when the locking disk  250  is in the unlocked position. Therefore, a distinct signal is generated designating the locking disk&#39;s locked, unlocked, and open positions.  
         [0063]    Operation of the latch  10  is best illustrated in FIGS.  28 - 30 . The latch  10  may be operated either manually or by the motor  450 . In the locked position, illustrated in FIG. 28, the locking disk  250  is rotated so that the window  270  is 90° to the pawl  300 , the roller switch  350  engages one cutout  268  so that it is open, and the deadstop lug  264  is at one end of the slot  118 . The keeper is secured between the pawl&#39;s arm  304  and the pawl nest  66 . The pawl&#39;s locking disk engaging tooth  302  abuts the locking disk  250 , thereby securing the pawl  300  in the latched position.  
         [0064]    To operate the latch  10  manually, a key is first inserted into the key slot  152  of the lockplug  150 . The wafers  158  retract as the key is inserted, allowing the lockplug  150  to rotate. The key is rotated clockwise. The lockplug driver  200  will engage the driver post  254 , rotating the locking disk  250 . If merely unlocking the latch  10  is desired, the rotation may stop anywhere in the unlocked range, such as illustrated in FIG. 29. As the locking disk  250  is rotated from the locked to the unlocked positions, the cantilever  352  of roller switch  350   a  is depressed, so that both roller switches  350  are closed. The pawl  300  remains secured in the latched position.  
         [0065]    Once the locking disk  250  is rotated to the unlocked position illustrated in FIG. 30, the window  270  is adjacent to pawl  300 , thereby permitting the pawl  300  to rotate from the latched to the unlatched position, releasing the keeper. The deadstop lug  264  reaches the opposite end of slot  118 , preventing further rotation of the locking disk  250 . The cantilever  352  of roller switch  350   b  is released, opening the roller switch  350   b . As force is released from the key, the lockplug  150  and lockplug driver  200  rotate under spring pressure to their central position wherein the wafers  158  engage the recess  64 , allowing removal of the key. The locking disk  250  will be spring-biased away from the open position, but will be secured in the open position by abutting pawl  300 .  
         [0066]    The latch may be closed by merely slamming it shut. The keeper will push against the arm  306  of the pawl  300 , thereby rotating the pawl  300  into the latched position. Once the pawl  300  is in the latched position, the keeper will be secured between the pawl nest  66  and pawl&#39;s arm  304 . The locking disk  250  is now free to rotate to the unlocked position of FIG. 29 under spring pressure. Both roller switches  350  are depressed, signaling the latch&#39;s unlocked position.  
         [0067]    To manually move the locking disk  250  from the unlocked position to the locked position, a key is first inserted into the key slot  152  of the lockplug  150 . The wafers  158  retract as the key is inserted, allowing the lockplug  150  to rotate. The key is rotated counterclockwise. For the first 45° of rotation, the lockplug driver  200  will rotate without engaging the driver post  254 . For the second 45° of rotation, the end of slot  214  will abut the driver post  254 , so that the lockplug driver  200  will rotate the locking disk  250 . Once the locked position is reached, the deadstop lug  264  reaches the end of slot  118 , preventing further rotation of the locking disk  250 . The cantilever  352  of roller switch  350   a  is released, opening the roller switch  350   a . As force is released from the key, the lockplug  150  and lockplug driver  200  rotate under spring pressure to their central position wherein the wafers  158  engage the recess  64 , allowing removal of the key.  
         [0068]    Operation of the latch using the motor  450  is accomplished through a combination of switches indicating the desired action of the user, and the signals from the roller switches  350   a ,  350   b  indicating the present state of the latch  10 . These inputs can, for example, be directed to a programmable logic controller (PLC) which then controls the flow of electricity to the motor  450 . The following illustration assumes a dashboard mounted switch for moving the locking disk  250  between the unlocked and open positions only, and a remote key switch for moving the locking disk  250  between the locked and unlocked positions.  
         [0069]    When the latch  10  is unlocked, both roller switches  350   a ,  350   b  will be closed. When the PLC receives a signal from either switch instructing it to open the latch  10 , it will activate the motor  450  until the roller switch  350   b  is open, signaling that the latch  10  is now open. When the PLC receives a signal from the key switch instructing it to lock the latch  10 , it will activate the motor  450 , supplying power to rotate the motor  450  in the opposite direction, until the roller switch  350   a  is open, signaling that the latch  10  is locked.  
         [0070]    When the latch  10  is locked, and the PLC receives a signal from the dashboard switch instructing it to open the latch  10 , the PLC will not open the latch  10 , because the roller switches  350   a ,  350   b  will signal that the latch  10  is locked.  
         [0071]    When the latch  10  is locked, and the PLC receives a signal from the key switch instructing it to unlock the latch  10 , the PLC will activate the motor  450  until the roller switch  350   a  is closed. Similarly, when the latch  10  is locked, and the PLC receives a signal from the key switch instructing it to open the latch  10 , it will actuate the motor  450  until the roller switch  350   b  is open.  
         [0072]    Any time the latch  10  is manually operated, the motor  450  will simply rotate with the locking disk  250  as the force is transmitted through the gearbox  400 . However, throughout electronic operation of the latch  10 , the driver post  254  will move within the slot  214  without ever rotating the lockplug driver  200  or lockplug  150 .  
         [0073]    It is to be understood that the invention is not limited to the preferred embodiments described herein, but encompasses all embodiments within the scope of the following claims.