Patent Publication Number: US-10316555-B2

Title: Truck roll-up door internal lock release

Description:
RELATED APPLICATION 
     This patent application claims the benefit of U.S. Provisional Patent Application No. 62/220,893 filed on Sep. 18, 2015. 
    
    
     BACKGROUND 
     Many commercial trucks and trailers and fire and emergency vehicles deployed on the road today are equipped with roll-up doors. These doors are constructed of a plurality of horizontal interlocked slats that travel up and down guide tracks along the vertical sides of the door frame. These roll-up doors may be constructed to suit a variety of applications and environments and may include a locking mechanism to secure the door. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an exemplary embodiment of an inside view of a roll-up door equipped with an internal lock release according to the present disclosure; 
         FIG. 2  is a more detailed perspective view of an exemplary embodiment of the internal lock release in its deployed position viewed from outside the cargo compartment with the roll-up door and the lift bar hidden from view for the sake of an unobstructed view according to the present disclosure; 
         FIG. 3  is a more detailed front view of an exemplary embodiment of the internal lock release in its deployed position with the roll-up door hidden from view for the sake of an unobstructed view according to the present disclosure; 
         FIG. 4  is a more detailed side view of an exemplary embodiment of the internal lock release in its deployed position along line B-B in  FIG. 3  with the roll-up door hidden from view for the sake of an unobstructed view according to the present disclosure; 
         FIG. 5  is a more detailed side view of an exemplary embodiment of the internal lock release in its deployed position along line A-A in  FIG. 3  with the roll-up door hidden from view for the sake of an unobstructed view according to the present disclosure; 
         FIGS. 6A and 6B  are a more detailed front partial view of an exemplary embodiment of a return ring mechanism of the internal lock release according to the present disclosure; 
         FIG. 7  is an exploded view of an exemplary embodiment of the internal lock release according to the present disclosure; 
         FIG. 8  is an exploded view of an exemplary embodiment of a spring assisted lock rod assembly of the internal lock release according to the present disclosure; 
         FIG. 9  is a front perspective view of an exemplary embodiment of the internal lock release in its stowed position with the roll-up door hidden from view for the sake of an unobstructed view according to the present disclosure; 
         FIG. 10  is a front perspective view of an exemplary embodiment of the internal lock release in its deployed position with the roll-up door hidden from view for the sake of an unobstructed view according to the present disclosure; 
         FIGS. 11 and 12  are more detailed perspective partial views showing the operations of the locking cam of the internal lock release with the roll-up door and lift bar hidden from view for the sake of an unobstructed view according to the present disclosure; 
         FIG. 13  is a detailed perspective view of an exemplary embodiment of the lock rod spring mechanism according to the present disclosure; 
         FIG. 14  is a detailed view of an exemplary embodiment of the lock cam and lock dog mechanism according to the present disclosure; and 
         FIGS. 15-17  are additional front perspective views of an exemplary embodiment of the internal lock release according to the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  is a perspective view of an exemplary embodiment of a roll-up door  10  equipped with an internal lock release assembly  12  viewed from inside the vehicle cargo compartment according to the present disclosure. Also called a roller shutter door, this type of doors have been deployed in work trucks, lube truck, utility truck, delivery truck, and fire and emergency vehicle applications. The roll-up door  10  is constructed of interlocked horizontal slats  14  that can be rolled up to permit unhindered access to a cargo compartment through the door opening framed by a door frame  16 . Many applications of roll-up doors have a preference for the ability to lock the door to prevent unauthorized access and theft. However, conventional lockable roll-up doors do not provide a mechanism to unlock the door from the interior of the locked compartment. The internal lock release mechanism  12  described herein is a safety feature that allows an occupant inadvertently locked inside the cargo compartment to disable or unlock the external door lock from inside the compartment. 
     Referring also to the various views presented in  FIGS. 2-17  with the roll-up door hidden from view for the sake of an unobstructed view, the internal lock release mechanism  12  is located on the inside surface of the door  10 . The internal lock release mechanism  12  includes a lift arm  20  disposed on the interior side of the door  10  that is in the horizontal stowed position when it is not in use (e.g.,  FIG. 9 ), and is in the vertical position when it is deployed (e.g.,  FIGS. 1 and 10 ) to unlock an electrical lock on the door  10 . 
     To unlock the door  10  by a user standing outside the vehicle cargo compartment, a key (not shown explicitly) is inserted into the lock cylinder  22  (see e.g.,  FIG. 2 ) and rotated, which causes a lock dog  24  to engage a lock cam  26  of the lock and rotate it. The rotational motion of the lock cam  26  causes the left and right lock rods  28  and  29  to retract from a spring-loaded mechanism  30  mounted in the left and right sides of the door frame  16  and controlled by an electrical lock, and thus unlocking the door. The user then manually raises a lift bar  36  disposed horizontally across the width of the door  10  so that the lift bar  36  clears the stationary strike blocks  38  located (see  FIG. 1 ) on either side of the door  10  on the door frame  16 , allowing the shutters to roll up. The stationary strike blocks  38  function like a mechanical door latch for the roll-up door  10 . This operation unlocks the door  10  from the outside using a key (not explicitly shown). While the user unlocks the door from the outside, the lift arm  20  disposed on the interior surface of the roll-up door  10  remains stationary in the stowed horizontal position during this operation. Similarly, when locking the door  10 , the lock cylinder  22  is turned with the key, which causes the lock cam  26  to rotate and extend the lock rods  28  into the spring-loaded mechanism  30  located in the door frame. The lock  22  and lift arm  20  operate independently. 
     In operation to unlock the door  10  from inside the vehicle cargo compartment, an internal release mechanism  12  is provided for a mechanical override or bypass of the lock  22 . Raising (rotating) the lift arm  20  disposed on the interior surface of the door  10  from the stowed (horizontal) position to the deployed (vertical) position causes a cable  40  attached between the lift arm  20  and a release bar pivot  42  to pull on the release bar pivot  42  to pivot or rotate about an axis along a pivot rod  43 . The release bar pivot  42  is disposed in the interior of the vehicle compartment, but is coupled to the pivot rod  43  located outside the vehicle compartment. The pivoted release bar pivot  42  in turn pushes against a push rod  44  and causes it to be displaced outward away from the door  10  and toward a center pivot block  46  disposed outside the door  10 . The center pivot block  46  is pivoted outward from the door  10  and in turn causes a lift bar  36  that passes through the center pivot block  46  as well as the left and right pivot blocks  48  to automatically raise out and up from under the stationary strike blocks  38  (see  FIG. 1 ) located outside the vehicle compartment and on either side of the door  10 . At the same time, the ramps on the lock dog  24  of the lock  22  to disengage from the lock cam  26  as the lock cam  26  is turned. A spring  52  housed within the internal release housing  54  of the lock  22  maintains pressure against the lock cam  26  so it re-engages the lock dog  24  as the lift arm  20  is returned to the stowed horizontal position. The rotation of the lock cam  26  enables the left and right lock rods  28  attached to the lock cam  26  to retract from the spring-loaded mechanism  30  located at the left and right sides of the door frame  16  so that the door can be rolled up. 
     The length of the cable assembly  40  attached to the lift arm  20  can be adjustable so that the left and right lock rods  28  and  29  can retract before the lift bar  36  is raised from under the stationary strike blocks  36 . This adjustability prevents the lock rods  28  and  29  from jamming and ensures smooth operation. 
     It should be noted that the internal lock release mechanism  12  is a mechanical override or bypass of a lock that is electrically powered and controlled, as well as manipulating the lift bar to clear a mechanical stop (the station strike blocks  36 ). As shown in  FIGS. 7-10 and 16 , the exterior portions of the internal lock release mechanism  12  may be contained in a framed structure  56  that helps to shield it from the elements and tampering. 
     The features of the present invention which are believed to be novel are set forth below with particularity in the appended claims. However, modifications, variations, and changes to the exemplary embodiments described above will be apparent to those skilled in the art, and the internal lock release mechanism described herein thus encompasses such modifications, variations, and changes and are not limited to the specific embodiments described herein.