Abstract:
A handle apparatus utilized for actuating mechanisms with a pair of parallel cables detects a cable out condition, and prevents further activation of the actuated mechanism. The apparatus has a yoke mechanism which is pivotally attached to an activation rod, which in turn is connected to an activation handle. The yoke mechanism has a first side and a second side, with one of the cables attached to the first side and the other cable attached to the second side. The yoke mechanism has a first stop member attached to the first side of the yoke mechanism and a second stop member attached to the second side of the yoke mechanism. The apparatus has stationary shoulders which are placed such that the stationary shoulders will engage the stop members if either cable fails.

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to various mechanisms which are operated by applying tension or compression with actuating cables and more particularly to latch mechanisms, such as some aircraft latches which are cable actuated latches. One of the drawbacks of utilizing cable actuation for various mechanisms is that for some systems, particularly those in which the cables are hidden, such as behind panels or covers, it is not immediately ascertainable that a cable has failed. In such cases, manipulation of a handle or lever may provide a false indication that the apparatus has been manipulated as desired, when in fact the cable failure has prevented actuation of the mechanism. In the case of latches, a handle might be manipulated such that the handle indicates that the latch is open or closed, when the latch has not been activated because of a cable failure. In some cases, particularly with aircraft devices, it is imperative that the status of the device be immediately ascertainable, such as whether the device has been manipulated as desired. 
     SUMMARY OF THE INVENTION 
     Embodiments of the disclosed apparatus detect a cable out condition for cable actuated mechanisms, providing an immediate indication to the operator of a problem with a cable. In a dual cable system, if one of the cables has failed the handle is prevented from achieving either the open position or the closed position. An embodiment of the apparatus comprises an activation handle for operating the particular mechanism, where the activation handle has a first position which indicates a first condition and a second position which indicates a second condition. The disclosed apparatus may be utilized with mechanisms which are actuated by parallel cables, including mechanisms which are actuated by the application of tension in the cables (“pull”) or compression (“push”). 
     In the case of a latch, the activation handle has a latch open position and a latch closed position, corresponding with the desired latch operation. It is to be appreciated that the disclosed apparatus may be used for latches which are opened by application of tension, or closed by operation of tension, thus the indications on the figures of “open” and “closed” are for illustrative purposes only. The apparatus further comprises means for operationally attaching parallel actuating cables to the activation handle, such that the activation handle may apply a uniform tension or compression to the cables. Such means may comprise a yoke mechanism which is pivotally attached to an activation rod, which in turn is connected to the activation handle. The yoke mechanism has a first side and a second side, with a first cable attached to the first side and a second cable attached to the second side. The yoke mechanism has a first stop member attached to the first side of the yoke mechanism and a second stop member attached to the second side of the yoke mechanism. The apparatus has a stationary first shoulder which is placed such that it will engage the first stop member if the first cable fails, because a failed cable will cause the yoke mechanism to pivot and operation of the activation handle drives a portion of the first stop member into the first stationary shoulder, stopping further motion of the activation handle. Likewise, if the second cable fails, the yoke mechanism will pivot in the opposite direction and a portion of the second stop member will be pulled into the stationary second shoulder and further motion of the activation handle will be stopped. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a right side perspective view of an embodiment of the invention. 
         FIG. 2  shows a left side perspective view of an embodiment of the invention. 
         FIG. 3  shows a front view of an embodiment of the invention. 
         FIG. 4  shows a rear perspective view of an embodiment of the invention. 
         FIG. 5  shows a left side view of an embodiment of the invention. 
         FIG. 6  shows a front view of an embodiment of the invention. 
         FIG. 7  shows a sectioned view taken along line  7 - 7  of  FIG. 6 . 
         FIG. 8  shows a perspective view of an embodiment of the invention, with the cable attachment mechanism shown in exploded detail. 
         FIG. 9  shows a perspective view of an embodiment of a shaft utilized in embodiments of the disclosed apparatus. 
         FIG. 10  shows a perspective view of an embodiment of a spindle utilized in embodiments of the disclosed apparatus. 
         FIG. 11  shows a perspective view of an embodiment of a sleeve utilized in embodiments of the disclosed apparatus. 
         FIG. 12  shows a perspective view of an embodiment of a bushing utilized in embodiments of the disclosed apparatus. 
         FIG. 13  shows an embodiment of the invention with cables attached. 
         FIG. 14  shows the embodiment of  FIG. 13  and how the device locks out in the event of a cable failure. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Referring now to the Figures, an embodiment of the disclosed apparatus  10  is depicted. An embodiment of the apparatus  10  has a handle assembly  12 , a housing  14 , an operating rod assembly  16 , and a cable attachment assembly  18 . References made below to the top, bottom, or sides of the apparatus  10  will be with respect to the orientation of the apparatus as depicted in  FIG. 1 , although it is to be appreciated that the apparatus will function in any orientation. It is also noted that the embodiments of the apparatus  10  shown in the Figures include the labels “closed” and “open” and generally refer to the utilization of the device with latches, particularly aircraft latches. Thus, for the embodiment depicted in  FIG. 1 , the rotation and shifting of the handle assembly  12  in a downward direction would result in a latch attached to the apparatus with parallel cables to be in the “open” position. However, the same apparatus might be utilized to close a latch by the same handle movement. 
     It is to be further appreciated that the apparatus  10  may be employed with other types of mechanisms besides latches. Any mechanism which is actuated by cables, either by push-pull actuation or by application of tension or compression, is a potential candidate for use in combination with the disclosed apparatus. 
     Handle assembly  12  may comprise a grip member  20  which is attached to a D-handle  22 . Handle assembly  12  further comprises a trigger  24  which is maintained in position biased apart from grip member  20  by biasing means, such as spring  26 . Handle assembly  12  is attached to spindle  28 , to which trigger  24  is attached by rivet  30 . Spindle  28 , shown in greater detail in  FIG. 10 , slides over shaft  54  to which grip member  20  is attached by rivet  34  or other fastening means. Trigger  24  freely travels over shaft  54  until rivet  34  reaches the top of a slot  62  in shaft  54 , at which point trigger  24  initiates movement in shaft  54   
     Housing  14  has integral mounting means such as attachment plate  36 , which maintains housing  14  in a stationary position during the operation of the apparatus  10 . As shown in the figures, housing  14  has at least a first selection slot  38  and a second selection slot  40 , which are generally oriented normal to the long axis of the housing. The selection slots  38 ,  40  are connected to one another by linking slot  42 . This configuration provides at least two positions for engagement of lock screw  44  within housing  14 . For the embodiment shown in the figures, when the lock screw  44  engages the first selection slot  38 , the apparatus being actuated by the cables is in the closed position Likewise, when the lock screw  38  engages the second selection slot  40 , the operated apparatus is in the open position. Of course, additional selection slots may be located within housing  14 , providing a variety of intermediate positions between selection slots  38 ,  40  as required by the functioning of the particular apparatus being actuated by the apparatus  10 . Linking slot  42  is generally oriented along the long axis of housing  14  as shown in the figures. As shown in the figures, housing  14  may comprise a generally rectangular shape having a long axis coinciding with the long axis of the shaft  54  which slides within housing  14 . Housing  14  further comprises a handle end  32  and a cable end  46 . The cable end  46  of the housing  14  may comprise a first shoulder  48  and a second shoulder  50 , which are utilized as described in greater detail below. 
     The operating rod assembly  16  is utilized to transmit the linear motion of the handle assembly  12  to cables  52 , and interacts with housing  14  to lock the operating rod assembly in various positions with respect to housing  14 , such that a desired tension is maintained in cables  52  for manipulation of the mechanism actuated by the cables. As shown in the sectional view of  FIG. 7 , the operating rod assembly comprises a shaft  54  having a portion of the shaft slidingly disposed within housing  14 . Shaft  54  comprises a handle end  56 , a cable end  58 , and an intermediate section  60  which slides within housing  14 . Shaft  54  further comprises a slot  62  which allows trigger  24  free travel as it is pulled toward grip member  20 . Operating rod assembly  16  may further comprise a sleeve  64 , as shown in detail in  FIG. 11 , which encircles a portion of shaft  54 . A guide bushing  66  is set within housing  14 , where the guide bushing guides the operating rod assembly  16  through the housing  14 , where the guide bushing has slots  68 ,  70  and  72  which are respectively aligned with the selection slots  38 ,  40  and linking slot  42  of the housing. Lock screw  44  is made up through an opening in sleeve  64  and attached into opening  74  of shaft  54 . 
     As best shown in  FIG. 8 , cable attachment assembly  18  is attached to the cable end  58  of shaft  54 . Attached to the cable end  58  of the shaft is rod bushing  76 . Inserted within the end of rod bushing  76  and pinned and/or riveted in place is connector  78 . Pivotally attached to the top of connector  78  are links  80 , or yoke members, which pivot about shaft  82 , which may comprise a rivet, fastener or similar member, which is inserted in opening  84  of connector  78 . Pivotally attached to links  80  are stop arms  86 , where a first stop arm is attached to one side of connector  78  and a second stop arm is attached to the opposite side by rivets  88  or like device. Each stop arm  86  has a top  90  and a bottom  92 . A length is defined between the top  90  and the bottom  92 , and a slot  94  extends along a portion of the length. A rivet  96 , fastener, or like device is inserted through a portion of the slot  94  of each stop arm  86 , where the rivet  96  is inserted through rod bushing  76 , such that the stop arms  86  are free to slide along the rivet  96  for the length of the slots, such that each stop arm  86  may slide with respect to the rivet  96 . The bottom  92  of each stop arm  86  has shoulder stop contact surface  98 . 
     As shown in  FIG. 13 , cables  52  are attached to links  80 .  FIG. 13  shows the apparatus in a static condition in which, because of equivalent tension in cables  52 , the links  80  are in a balanced position, with the load evenly applied to shaft  82 . In order to operate the apparatus  10 , trigger  24  must be pulled toward grip member  20 . Once trigger  24  is pulled a sufficient length to initiate movement in the operating rod assembly  16 , grip member  20  and trigger  24  are rotated in a direction which moves lock screw  44  from selection slot  38  into linking slot  42 . Handle assembly  12  is then pulled away from housing  14  a sufficient distance to place lock screw  44  adjacent to selection slot  40 , at which point grip member  20  and trigger  24  are rotated in a direction to move lock screw  44  into selection slot  40 . 
       FIG. 14  depicts what occurs in the event of a cable failure. As illustrated in  FIG. 14 , one of the cables  52  has failed. If this occurs, during the sequence described above, as the handle assembly  12  is pulled away from the housing  14 , the links  80  pivot downward on the side of the cable failure, causing the stop arm  86  to slide with respect to rivet  96 , causing shoulder stop contact surface  98  to come into engaging contact with first shoulder  48 , or second shoulder  50 , depending upon which cable fails. Once shoulder contact surface  98  comes into engaging contact with first shoulder  48  or second shoulder  50 , further movement of the shaft  82  is stopped, and the lock screw is prevented from engaging selection slot  40 , and the handle assembly  12  will not be moveable any further. Thus, the operator of the apparatus is provided an affirmative indication of a cable failure and the cables cannot be moved so as to actuate the particular mechanism. 
     While the above is a description of various embodiments of the present invention, further modifications may be employed without departing from the spirit and scope of the present invention. Thus the scope of the invention should not be limited according to these factors, but according to the following appended claims.