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Breech and Muzzle Door Interlock 38
Tube Drain Valve and Muzzle Door Interlocking Mechanism 42
Firing Interlocking Mechanism 44
Interlock Disconnect 46
37
BREECH AND MUZZLE DOOR INTERLOCK
FOREWORD: Plate Two, which showsdiagramatically the complete interlocksystem for a torpedo tube having amanually-operatedmuzzle door
Figure 70, or F in Figure 72) is operatedby hand, independently of other gear. Inthepower-operatedmechanism, thebreech and muzzle door interlock lever is
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mechanism, and Plate Three, whichsimilarly pictures one for a tube havingapower-operatedmuzzle doormechanism, should be referred to inconnection with the more detailedfigures and text of this chapter. In
general, the differences between theinterlock systems are:
(1) The interlock slide, which is movedfore-and aft by threads on the muzzledoor operating shaft in the manually-operatedmechanism, is driven bygears, sprockets and a chain from theoperating shaft of the power-operatedgear.
(2) In the manually-operated
mechanism the breech and muzzle doorinterlock lever (A in
linked to the drain valve and muzzle doorinterlock lever by a connecting rod (A inFigures 74 and 77) so that the twooperate together.
(3) In general, the interlocking bolts
operate with the interlock slide in thesame manner, regardless of whether themuzzle door operating mechanism is ofthe manual- or power-operated type.However, in order to properly control theoperation of the control valve in thepower-operated type, the interlock boltsengage the thrust rod or attached parts aswell as the interlock sleeve. Also, in thepower operated type, these bolts do notprevent the operation of the emergencyhand drive, so additional
Figure 68 The breech bracket andinterlocking levers, showing their
position with relation to the breech
door. (A) Firing mechanism interlocklever; (B) Tube drain valve and muzzle
door interlock lever; (C)Indicator
showing position of muzzle door whileopening and closing; (D) Breech and
muzzle door interlock lever; (E) Breech
bracket, in which the cylindrical slidemoves as the muzzle door operating shaft
is turned.
38
linkages are provided from the breechand muzzle door interlock lever andfrom the firing interlock lever to the
depth and speed spindles are retractedfrom their sockets in the torpedo, (4) theiring stop valves are locked open, (5) the
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hand operating shaft, each linkageconsisting of a long connecting rod anda bellcrank lever which has a tip shapedlike a gear-tooth so that it will engage agear which is keyed on to the handoperating shaft. These linkages perform
the same functions with respect to theemergency hand shaft that the interlockbolts perform with respect to thepower-operated gear.
In this chapter, Figures 68 to 73, 77, 79,80 to
drain valve is locked closed.
The interlocking mechanism consists ofthree sections: The Breech and MuzzleDoor Interlock; the Tube Drain Valveand Muzzle Door Interlock; and the
Firing Mechanism Interlock. The leversand indicators for these interlocks areshown in Figure 68.
In general, the interlocking mechanism ismechanical throughout and centers aboutthe muzzle door operating shaft, whichextends (in the manual
Figure 69 Cylinder slide and breech end of muzzle door operating shaft, showing
(A) Acme thread on breech end of muzzle door operating shaft; (B) Slot for breech
and muzzle door interlock bolt; (C) Bolt disengaged from and in line with slot in
slide, in muzzle door unlocked position.83, and 85, strictly apply only wheremuzzle door operating mechanisms areof the manual type. Figures 74 and 75apply where thepowertype is installed.Figures 76, 78 and 84 may beconsidered illustrative for either type.
The interlocking mechanism actually isprotection against improper operationof the tube. It prevents (a) opening thebreech doorwhen the muzzle door isopen, and opening the muzzle doorwhen the breech door is open; also, itprevents (b) opening the drain valvewhen the muzzle door is open, andopening the muzzle doorwhen the drainvalve is open. It prevents (c) firing ofthe tube except when (1) the muzzledoor is locked open , (2) the breechdoor is locked closed, (3) the
Figure 70 Breech bracket, showingbreech and muzzle door interlock lever
(A) at muzzle door unlocked position.
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39
Figure 71 Cylindrical slide, showing (A) interlocking bolt raised into slot,
preventing movement of slide and locking muzzle door operating shaft.
Figure 73 Cylindrical slidedisassembled, showing (A) Muzzle door
indicator; (B) Ring with pointer andtooth in (C) Helical groove in
cylindrical slide; (D) Slot for head of
drain valve interlock rod; (E) Slot forbreech and muzzle door interlock bolt;
(F) Acme thread on (G) Breech end of
muzzle door operating shaft.
type) from the gearing at the muzzle doorto the breech bracket over the breech endof the tube.
TheBreech and Muzzle Door Interlockcontrols the opening and closing of thebreech and muzzle doors. It is soarranged that when one door is open theother door is closed and locked tight.
In the "manually operated" type ofmuzzle door operating mechanism, a
cylindrical slide engages an acme threadon the breech door end of the muzzledoor operating shaft (Figure 69) andslides in the breech bracket (Figure 70).This cylindrical slide moves away fromthe operator when closing the muzzledoor, and toward the operator whenopening the muzzle door. The distancethis slide travels between the extremepositions is 4.858 inches. By means ofslots, this cylindrical slide engages boltsin the breech and muzzle doorinterlocking system (see Figures 69 and71), also in the drain valve and the firinginterlocking systems.
The breech and muzzle door interlockingbolt (Figures 69 and 71) is actuated by abreech and muzzle door interlock lever(Figures 70 and 72). When the muzzledoor is fully closed, the slot in the slide is
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in line with the interlocking bolt (Figure69) and the interlock lever can be movedto "Breech Door Unlocked" position(Figure 72). In this position, the interlockbolt is raised into the slot of the slide(Figure 71), clearing the lug on the
breech door locking ring, and allowingthe locking ring to be rotated so thebreech door can be opened. The lug onthe locking ring prevents the bolt frombeing lowered while the breech door isunlocked. When the breech door isclosed and locked, the interlock lever canbe moved to "Muzzle Door Unlocked"position, as in Figure 70, and the boltgoes to its lower position where it is clearof the slot in the slide, as in Figure 69.
As the muzzle door opens or closes, itsmovement
40
Figure 72 Breech bracket, showing breech and muzzle door interlock lever atbreech door unlocked position. (A) Cylindrical slide; (B) Indicator showing
position of muzzle door when opening or closing. (C) Breech bracket; (D) End of
muzzle door operating shaft for attaching handle; (E) Indicator, showing (F)Breech and muzzle door interlock lever at breech door unlocked position, ready forunlocking and opening the breech door.
is shown on the Muzzle Door Indicator(see Figure 73, also C in Figure 68).This indicator consists of a ring with apointer on its outer surface orcircumference, and, a tooth
operated by a control valve, the controlvalve being set in action by a thrust rodwhich moves through the interlock sleeveand the breech bracket. This controlvalve cannot be set in action unless the
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immediately below it on the innersurface of the ring. The tooth engages ahelical groove in the slide, so that as theslide moves backward or forward theindicator moves, showing the positionof the muzzle door on the scale.
With the power-operated mechanism,the shaft for opening and closing themuzzle door is operated by a hydrauliccylinder which, in turn, is
interlocks are in proper position.
Rods extend down from the breech andmuzzle door interlock lever and from thedrain valve and muzzle door interlocklever, and connect with gearing which
locks or unlocks the emergency handoperating shaft (H in Figure 45, page 32).The interlock slide is moved backward orforward by an interlock chain.
Figure 74 New connecting rod(A) Linking the breech and muzzle door interlocklever with the drain valve and muzzle door interlock lever so the two operate
together. Levers as shown are at muzzle door locked, and breech door unlocked,
positions. At right, Figure 75, levers are shown at muzzle door unlocked, and drain
valve locked, positions.
41
TUBE DRAIN VALVE AND MUZZLE DOOR INTERLOCKING
MECHANISM
Figure 76 Drain valve interlock,showing (A) Rod extending up to
interlock lever and cylindrical slide;
(B) Collar on drain valve shaft
disengaged, valve unlocked.
Figure76Drainvalveinterlock The interlocking mechanism alsoprovides an interlock between the tubedrain valve and the muzzle door, so thatthe muzzle door can not be opened unlessthe tube drain valve is closed.
The tube drain valve, located just underthe breech end of the tube, is operated bya lever attached to a shaft, at one end of
which is a collar (B in Figure 76). Thiscollar is locked or unlocked by movingthe drain valve and muzzle door interlocklever (A in Figure 77). The interlocklever has a pinion gear which engages arack gear (B in Figure 77) attached to arod (A in Figure 76) which extends downto a lever which operates an interlockbolt which operates on the collar on the
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drain valve stem (B in Figure 76). Thisrod also extends up to the cylindricalslide, as shown at C in Figure 77.
Figure 77 Drain valve and muzzle door interlock, showing (A) Lever at muzzle
door closed position; (B) Pinion gear and rack with (C) Head of rod in upper
position, engaging slot in cylindrical slide.
42
When the interlock lever is at "MuzzleDoor Closed" position, the head of therod engages the slot in the cylindrical
slide (C in Figure 77) so the muzzledoor operating shaft can not be moved.The collar on the drain valve stem isdisengaged, as shown at B in Figure 76,and the drain valve lever may be movedto open the drain valve.
The collar on the drain valve shaft islocked, as shown at B in Figure 78,when the interlock lever is moved to"Drain Valve Locked" position, thuspreventing movement of the drain valvelever, and the head of the roddisengages the cylindrical slide, asshown in Figure 79, permittingmovement of the muzzle door operatingshaft so as to open the muzzle door.
This interlock acts in the same manneron tubes which have power-operatedmuzzle door mechanism.
Figure 78 Drain valve shaft, showing (A)
Rod in lower position, engaging (B)
Collar on drain valve shaft and lockingvalve.
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Figure 79 Drain valve interlock, showing (A) Interlock lever at drain valve locked
position, with (B) Head of rod disengaged from slot in slide, releasing muzzle door
operating shaft.
43
Figure 80 Firing interlock disassembled, showing (A) Lever in muzzle doorunlocked position; (B) and(C) Gearing drive for firing interlock bolt through idler
mounted on muzzle door operating shaft; (D) Firing interlock bolt, shown turned
out of the way of interlock slide. (Compare with Figure 82.)
FIRING INTERLOCKING MECHANISMFiring Interlocking Mechanism
prevents firing the tube until otherinterlocks are correctly set.
The firing interlock lever rotates theinterlock sleeve (Figure 80). When thelever is at "Muzzle DoorUnlocked" (Figure 81) the interlocks onthe depth and speed setting mechanismsare released so the spindles can be
the spindles of the setting mechanisms
have been disengaged from the torpedo,the tube firing system is released readyfor firing.
Raising the firing interlock lever from"Muzzle Door Unlocked" to "TubeReady to Fire" also rotates the sleevehead which moves the shutter bar so theopening in the shutter bar is lined up to
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moved in to engage the mechanisms inthe torpedo. When the depth and speedsetting mechanisms are engaged withthe torpedo, hubs on the interlocksleeve prevent rotation of the interlocksleeve head by the firing interlock
lever.
When the firing interlock lever ismoved to "Tube Ready toFire" (Figures 82 and 83), after
allow the piston of the torpedo stopcylinder to pass through it and set thefiring mechanism in
Figure 81 Firing interlocking mechanism, showing (A) Lever in muzzle doorunlocked position, and(B) Pinion and gear attached to interlock sleeve through
which muzzle door operating shaft passes; (C) Position of cylindrical slide. (Also
see Figures 80, 82 and 83.)
44
Figure 82 Firing interlock disassembled, showing (A) Lever in tube ready to fireposition; (B) and(C) Gearing drive for firing interlock bolt through idler mounted
on muzzle door operating shaft; (D) Firing interlock bolt, shown turned so as to
prevent interlock slide from moving toward muzzle.operation after the firing key is pressed.The shutter bar (J in Figure 96 or N in
of the leakage of air under pressure intothe stop cylinder. In such case, the end of
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Figure 99, on pages 52 and 53), inaddition to the hole intended for thepassage of the stop piston extension,has a recess which registers with theend of the stop piston extension whenthe firing interlock is set for "Muzzle
Door Unlocked." The purpose of thisrecess is to engage the end of the stoppiston extension if it should be forcedbreechward as by reason
the stop piston extension locks theshutter bar, so the firing interlock cannotbe thrown to "Tube Ready to Fire"position. (If it could be so thrown whilethere was pressure in the stop cylinder,the tube would fire immediately.) At the
same time, the electric interlock switch(not adequately shown on anyillustration, but actuated by movement ofthe shutter bar) is closed, lightinginterlock indicator lights.
At the same time, the firing interlock bolthas been rotated downward, engaging themuzzle door end of the interlock slide(Figure 83), thereby locking the muzzledoor in its open position.
Figure 83 Firing interlocking mechanism, showing (A) Lever in tube ready to fire
position; (B) Pinion and gear attached to the interlock sleeve; (C) Cylindrical
slide locked to prevent movement of muzzle door operating shaft. (Compare withFigure 81.)
45
INTERLOCK DISCONNECT
Provision is made for disconnecting thefiring interlocking mechanism in orderto permit of testing the operation of thefiring mechanism. This test consists offiring what is called an "inboard slug,"or a charge of air, while the breech dooris open.
To make this test, the lock on the
the interlock signal arm is raised tovertical position, showing the "Danger,Interlock Disconnected" warning flag(see B in Figure 85), also disengaging thefiring interlock clutch shaft (see A inFigure 85) and permitting the stop andfiring mechanism to function, regardlessof the position of the breech door or thedrain valve interlock levers, for the
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Copyright (C) 2004 Historic Naval Ships AssociationAll Rights ReservedLegal Notices and Privacy PolicyVersion 1.10, 22 Oct 04
interlock disconnect (see Figure 84) isunlocked and removed,
purpose of testing the firing mechanism.
Figure 84 Firing interlock disconnect, showing (A) Clutch shaft engaged; (B) Lock
which must be removed to disconnect interlocking mechanism; (C) Interlock signalarm. Compare with Figure 85, below, showing the cylindrical slide disassembled,
with (A) Clutch shaft disengaged, and(B) Interlock signal arm raised to show
warning flag.
46
Plate 3 - Interlocking Mechanism for Power Operated Doors
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