254,257. Schneider et Cie. June 27, 1925, [Convention date]. Launching torpedoes.-The starting and setting keys are interlocked with the back door of a torpedo tube so that the door cannot close unless the keys have previously been placed in the operative position. The front door is prevented bv known mechanism from opening until the back door is closed. The opening of the front door automatically withdraws the setting keys and the usual torpedo stop. Similarly, the opening of the back door withdraws the setting keys. The setting keys are made in two parts connected by an Oldham's coupling to permit the engagement of the key with the corresponding part on the torpedo even when these are not quite in line with each other. As shown in Fig. 4, a setting key for the gyroscope is made in two parts c<1>, c<2> connected together bv an Oldham's coupling c<3> with interengaging rollers c<4>. The part c<1> is bevelled to fit a corresponding bevelled member T on the torpedo, the Oldham's coupling allowing the part c<1> to take the line of the member T. The part c<2> is feathered through a pinion e<1> journaled in a casing C fixed to the torpedo tube A' and carries a sleeve d<4> with transverse pins d<3>, by means of which it is connected to a forked lever d<1> on a shaft D. The pinion e' is in mesh with a pinion e<2> on a shaft E<1> connected to another shaft E<2>, Fig. 2. by a known kind of device E<3> permitting an angular setting between the two shafts . The shaft E<3> leads to a known kind of bearing indicator F<1> or to a simple handle for giving the key c<1> the required rotational setting. The rear end of the shaft D has a crank d<5>, Fig. 8, connected by a link d<6> to another crank d' on a spindle d<9> provided with a handle d<8>. This handle is, moreover, connected by a slot-and-pin joint to a bar G slidably mounted transversely over the tube on brackets g<1>, g<2>. Bell cranks h', h<2> and i<1>, i<2> are mounted on pivots h<3>, i<3> on the tube adjacent to the rod G and coact with lugs g<3>, g<4> thereon. The arm h<1> of the first bell crank carries at its end a finger h<7> pivoted on it at h<8>; the finger can be deflected to the left by a lug k on the locking ring A<4> of the back door A<3> of the tube but its return movement to the left is stopped when it comes back into line with the arm h<1>. The other arm h<2> of this bell crank is connected to a longitudinally sliding rod h<5>. The other bell crank is connected by a link i<4> to a lever i<7> connected to the piston A<6> of the ram A<5>, by means of which the front door A<2> is opened about its hinge A<9> through the intermediary of crank A<8> and link A<7>. This mechanism functions as follows : If the key c<1> is not in operative engagement with the member T, the transverse bar G is at the right-hand end of its movement and the rod h<5> projects backwards in the way of a lug K<1> on the locking ring A<4> of the back door, which cannot therefore be shut. So long as the back door is not shut, wellknown mechanism, not shown, prevents the accidental operation of the launching devices. When the key c<1> is brought into operative engagement with the member T. the bar G is shifted to the left and by means of the bell crank h<1>, h<2> pulls the rod h<5> forwards out of the way of the lug K<1>. The back door A<3> can now be closed and locked by the ring A<4> . After this, the front door A<2> may be opened by the ram A<5> to discharge the torpedo. At the end of the stroke of the ram A<5>, fluid pressure is passed on to another ram Q which withdraws the usual torpedo stop O. The ram A<5> also operates at the same time the. bell crank i', i<2> through the linkwork i<7>, i<4>, and this movement of the bell crank shifts the bar G back to the right and withdraws the key c<1> from the member T, leaving the torpedo unobstructed in its discharge. The bell crank i<1>, i<2> instead of being operated by the ram A<5> may be operated by the ram Q through a link p<1>. When the back door is closed and locked as stated above, the lug k deflects and rides past the finger h<7>, which, in its turn, deflects the end n<1> of a lever pivoted at m, the other end n<2> being thus brought in the path of the lug k. The lug k in passing this lever returns it to its original position and with it the finger h<7>, which then again projects in the return path of the lug k. If, after this, it is desired to remove the torpedo from the tube. the back door A<3> is unlocked and opened. In the unlocking rotation of the ring A<4>, the lug k bears on the finger h<7> in the direction in which the finger cannot yield, the bell crank h<1>, h<2> is therefore rocked back to the left with the bar G, causing the withdrawal of the key c<1> from its member T, leaving the torpedo free for removal. At the same time, however, the rod h' is again projected into the path of the lug K<1>, preventing reclosing and locking of the back door until the key c<1> has again been brought into operative position by the handle d<8>. Any number oi' keys may be simultaneously controlled by the transverse bar G; for example as shown in Fig. 21, a key C<2> for the air retaining valve of the torpedo may be connected to the bar G by linkwork t<3>, t<5>.