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.
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.
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
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
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
As best shown in
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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.
Number | Name | Date | Kind |
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2581080 | Cushman | Jan 1952 | A |
3169409 | Babacz | Feb 1965 | A |
3831406 | Gebhard et al. | Aug 1974 | A |
3831409 | Gebhard et al. | Aug 1974 | A |
Number | Date | Country | |
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20120180595 A1 | Jul 2012 | US |