Abstract:
A rotary latch system where a rotary latch has a trip pawl and a latch jaw which engages a striker. When a T-handle is turned, rotation is translated via a rotating member to an actuating lever. Movement of the lever triggers the pawl which releases the latch jaw. Linkages to other latches can be easily made by connecting to pins upon the rotating member. The latch can then act as a master latch which operates a group of latches. T-handle is spring biased to return to its starting position on release. A locking embodiment provides a lock assembly which interferes with the rotation of the actuating lever when system is in a locked position.

Description:
This application claims the benefit of U.S. provisional patent application No. 60/173,015 filed on Dec. 23, 1999, the entirety of which is hereby incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention pertains generally to latches and, more particularly to rotary latches which are operated by rotation of a handle. 
     BACKGROUND OF THE INVENTION 
     Rotary latches are used on any sort of door which needs to be held in a closed position. The benefit of most rotary latches is that the door to which they are mounted will spring open upon latch release and may be slammed back to a closed, latched position. A latch is released upon its actuation, which is commonly done via a handle. The handle and latch comprise a system and are typically mounted together upon a pan which is in turn attached to the door being latched. The most common handle used to actuate a rotary latch when both are mounted to a common pan is a paddle handle, as shown in U.S. Pat. No. 4,911,487. 
     The T-handle is used in some latch systems because of its strength, durability, and compact design. The T-handle has been used in latch systems which do not include a rotary latch, such as U.S. Pat. No. 5,526,660. Because a great deal of force can be translated through the T-handle, it is often used in a system where rotary latches or other devices being actuated are not mounted to the pan upon which the handle is mounted, but are located at a distance from this pan. The force of turning the handle is translated via rod or cable to the latch or device. Often multiple rods or cables are attached to a single T-handle, allowing coinciding actuation of multiple devices.(see FIG. 31 in U.S. Pat. No. 4,706,478) One problem with prior art latch systems is that they do not utilize a T-handle to actuate a rotary latch mounted upon a common pan. A further problem with prior art systems is that a T-handle is not used to actuate a rotary latch mounted to a common pan as well as devices not attached to the pan. 
     It is desirable to have a new rotary latch system which utilizes the durability and compact design of a T-handle in conjunction with a rotary latch where both latch and handle are mounted to the same pan. Further, it is desirable to utilize the strength of the T-handle by including a way to actuate latches or devices not mounted to the pan as well as the local latch. 
     SUMMARY OF THE INVENTION 
     The present invention overcomes these and other disadvantages in the prior art. The invention provides in one aspect a latch which functions as a releasable closure mechanism comprising a pan having a well with exterior and interior sides, a latch assembly attached to the pan generally along side the well, the latch assembly having a latch jaw and a trip pawl, an actuating lever rotationally mounted proximate to the pan and disposed in a plane generally parallel to the pan, the actuating lever configured to actuate the latch assembly to a release state, a shaft having first and second ends extending generally perpendicularly through the well and the mounting plate, a handle attached to the first end of the shaft on the exterior side of the well, and a rotating member attached to the second end of the shaft on an interior side of the well, with the actuating lever located between the rotating member and the interior side of the well, the rotating member positioned to contact the actuating lever upon rotation of the rotating member, so that the actuating lever trips the latch assembly. 
     The invention provides in another aspect a latch which functions as a releasable closure mechanism, the latch comprising a mounting plate having interior and exterior sides, a latch assembly attached to the said mounting plate, the latch assembly having a latch jaw and trip pawl, a shaft having first and second ends extending generally perpendicularly through the mounting plate, a handle attached to said first end of the shaft on the exterior side of the plate, a rotating member attached to said second side of the shaft, an actuating lever attached to said mounting plate and being in physical contact with said rotating member and said trip pawl, and said actuating lever configured to actuate the latch assembly upon rotation of said rotating member. 
     These and other aspects of the invention are herein described in particularized detail with reference to the accompanying Figures. 
    
    
     DESCRIPTION OF DRAWINGS 
     FIG. 1 shows a front view of a latch with the T-handle in a retracted position, 
     FIG. 2 shows a perspective view of the back side of a latch with connecting linkages extending from the latch, 
     FIG. 3 shows a back side view of the latch in a position where the handle has not been turned and the latch has not been released, 
     FIG. 4 shows a top view of the rotary latch assembly specifically showing the latch jaw and trip pawl in an unreleased position, 
     FIG. 5 shows a back side view of the latch in a position where the handle has been turned and the latch jaw and trip pawl released, 
     FIG. 6 shows a top view of the rotary latch assembly specifically showing the latch jaw and trip pawl in a released position and the entire latch moving away from the striker, 
     FIG. 7 shows a side view of the latch in a position where the handle has not been turned and the latch has not been released, 
     FIG. 8 shows a back side view of the latch having a rotating member of reduced size, 
     FIG. 9 shows a perspective view of the back side of a latch with connecting linkages extending from the latch. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As shown in the Figures, a latch, indicated generally at  10 , has a mounting pan  12  with a peripheral flange  14 , which is typically mounted flush on an exterior surface of a panel or door which the latch operates. To accomplish such mounting, fasteners, preferably threaded studs or rivets  15  may be provided to extend from an interior side  16  of flange  14 . An exterior side  17  of the pan, as shown in FIG. 1, is thus exposed in a typical installation. The pan  12  further has a well  20 , recessed from exterior side  17 , and in which an operating handle  22 , such as a T-handle, fits in a retracted position. The T-handle  22  has forked extension  23  which is pivotally mounted upon a distal end  26  of a shaft  25  which extends through the well  20  of the pan. A cap washer  24  is provided about the distal end  26  of the shaft  25  between the exterior side of the well and the T-handle. An annular elastic seal  27  is provided between the cap washer  24  and the exterior side of the well, as shown in FIG.  7 . The seal prevents moisture and foreign objects from passing through the pan, and dampens vibration of the T-handle against the pan and washer. The distal ends of the T-handle forked extension  23  are rounded to facilitate transition of the handle between the retracted position shown in FIG. 1, and the extended operational position shown in FIG.  7 . 
     As further shown in the Figures, an optional latch mounting plate  32  is mounted on an interior side  30  of the well  20  of the pan, by fasteners  31  such as rivets or bolts. The mounting plate  32  substantially increases the strength of the overall latch system, as in this embodiment it covers substantially the entire expanse of a major flat portion of the well. The mounting plate  32  is not required and alternatively all parts mounted to plate  32  may be mounted directly to pan  12 . An actuating lever  35  is rotationally mounted about one of the attachment points of the plate  32  to the pan, or alternatively rotationally mounted upon a pin extending from the mounting plate  32 . The actuating lever  35  thus rotates in a plane parallel to the mounting plate and, as shown in FIG. 7, it can be closely parallel to the mounting plate. 
     The mounting plate  32  additionally comprises a flange  33  which extends perpendicularly from the major flat portion of the mounting plate and away from the pan. Preferably, flange  33  is integrally formed with mounting plate  32 , but may also be a separate piece attached by welding or other methods of fastening. Mounted upon the flange  33  is a rotary latch assembly indicated generally at  40 . The rotary latch assembly  40  has a cover plate  41  attached to flange  33  by laterally spaced parallel pins  44  and  45 . The flange  33  and latch cover plate  41  together form a housing in which a latch jaw  46  and a cooperating trip pawl  47  are rotationally and spring-biased mounted upon pins  44  and  45 , respectively. The latch jaw  46  is spring biased to an unlatched position. The trip pawl  47  is spring biased to a position of engagement with the latch jaw  46 . The latch jaw  46  preferably has a U-shaped opening which is designed to accept entry of a striker  63 . The striker  63  is commonly mounted to a door jam if the latch is mounted upon a door. The cover plate  41  is also preferably equipped with a U-shaped notch  43  to receive the striker  63 . Between the U-shaped surfaces of the latch jaw  46  and the cover plate  41 , the striker  63  can be held in place when the latch  10 , as shown in FIG. 4, is in a latched position. Cover plate  41  also has a tab stop  48  which stops the rotation of latch jaw  46  when the rotary latch is released. 
     Referring to FIG. 7, shaft  25  passes through the well  20  of pan  12  and mounting plate  32 . Rotating member  50  is mounted on the proximate end of shaft  25  and is held in place by a nut  28 . On shaft  25 , in between mounting plate  32  and rotating member  50  is a bushing  53 . This gives the appropriate clearance between rotating member  50  and actuating lever  35 . Referring to FIG. 3, one edge  51  of rotating member  50  is flat and is in contact with mounting plate  32  when the handle  22  is in an unrotated position. Thus rotating member  50  acts as a stop for the return rotation of handle  22 . The rotating member has a contact pin  52  which extends generally perpendicularly from the generally planer rotating member  50  proximate to a tab  38  of the actuating lever  35 . In a preferred embodiment rotating member  50  is a predominately circular disk. However, rotating member  50  need not be disk shaped, and may be any shape and size which is adapted to provide a flat surface  51  for stopping, the contact pin  52  and optional apertures  53  as shown in FIG.  8 . Contact pin  52  is in constant contact with tab  38 . In some embodiments, tab  38  may not be necessary and the contact pin  52  could simply contact an edge of a generally planer portion of the actuating lever  35 . 
     Preferably, rotating member  50  has one or more apertures  53 , as shown in FIG. 5, aligned radially on its face. A linkage connector pin  54  may be affixed within any of the apertures  53 . The latch  10  may employ no connector pins or up to an amount equal to the number of apertures  53  available. The linkage connector pin  54  extends perpendicularly from the face of rotating member  50 . The length of linkage connector pin  54  varies depending upon the amount of clearance needed between a linkage  55  and other parts of the latch. Linkage  55 , which is mounted to linkage connector pin  54 , extends from the latch  10  to a distant rotary latch or other device as shown in FIG.  2  and in FIG.  9 . Linkage  55  may be a rigid rod or flexible cable. The latch  10  may employ no linkages  55  or up to an amount equal to the number of apertures  53  available. 
     Actuating lever  35  is a generally flat plate which has the following non planer actuation surfaces: trip finger  36 , tab  38 , and lock contact surface  39 . Trip finger  36  is preferably an L shaped extension whose superior leg is perpendicular to the flat plane of actuating lever  35 , and whose inferior leg is parallel to the plane of the actuating lever  35 . Trip finger  36  is located at one end of actuating lever  35  and is positioned for contact with trip pawl  47 . At the opposite end of actuating lever  35  is lock contact surface  39 . Lock contact surface  39  is a tab extending outwards perpendicularly from the flat plane of actuating lever  35 . One end of lock contact surface  39  extends beyond the width of actuating lever  35  and serves as a means to mount one end of a helical tension spring  60 . The opposite end of spring  60  is attached to an area generally along the junction of mounting plate  33  and cover plate  41 . Spring  60  acts to place rotating member  50  in contact with mounting plate  32 . 
     An optional common barrel lock  61  may be used to lock the actuating lever  35  and handle  22  in an unrotated position. The face of lock  61  is mounted on the face of latch  10  as shown in FIG.  1 . The barrel lock passes through mounting pan  12  into the latch interior. Lock  61  has a tang  62  that contacts nothing in an unlocked position, but contacts lock contact surface  39  of actuating lever  35  when in a locked position in order to prevent rotation of lever  35 . 
     The operation of the latch assembly can now be described. In order to release the striker  63  from the latch  10 , the latch jaw  46  which holds the striker  63  must be released. First, the tang  62  of barrel lock  61  is rotated to a position not in contact with lock contact surface  39 . Next, handle  22  is unfolded from pan  12  and rotated. When handle  22  is rotated, shaft  25  and rotating member  50  also rotate. Contact pin  52 , mounted upon rotating member  50  engages and moves actuating lever  35 . When actuating lever  35  moves, trip finger  36  engages trip pawl  47 . The movement of trip pawl  47  releases latch jaw  46  and thus releases striker  63  from the latch  10 . 
     Next the handle  22  is released. When handle  22  is released, spring  60  pulls upon and moves actuating lever  35 . Actuating lever  35  contacts and moves contact pin  52  which is mounted upon rotating member  50 . Rotating member  50  rotates until contact is made with flange  33 . In order to lock the latch system  10 , the barrel lock  61  is rotated so that tang  62  is in contact with lock contact surface  39  of actuating lever  35 . Thus, no rotation of the actuating lever  35 , rotating member  50 , shaft  25  or handle  22  is possible. 
     In an alternate embodiment, rotation of rotating member  50  moves a linkage  55 . Movement of linkage  55  may trigger latches or other devices which are not mounted upon pan  12 . 
     Although the invention has been shown and described with respect to certain preferred and alternate embodiments, the invention further includes other obvious variations which adopt or include the basic principles of the invention.