US3371578A

US3371578A - Rocket launchers

Info

Publication number: US3371578A
Application number: US558656A
Authority: US
Inventors: Paul V Choate; Frank A Spinale
Original assignee: Norris Industries
Current assignee: NI West Inc
Priority date: 1966-06-20
Filing date: 1966-06-20
Publication date: 1968-03-05
Anticipated expiration: 1985-03-05

Description

March 5, 1958 p v CHQATE ET AL ROCKET LAUNCHERS 4 Sheets-Sheet 1 Filed June 20, 1966 March 5, 1968 P. v. CHOATE ET AL ROCKET LAUNCHERS 4 SheetsSheet 2 Filed June 20, 1966 TR N r F W k mm mu. 0v rm n$ m3 mv v um VT March 5, 1968 CHOATE ETAL 3,371,578

ROCKET LAUNCHERS 4 Sheets-Sheet 3 June 20, 1966 Filed l/l \\\N l/lI/ March 5, 1968 P. v. CHOATE ETAL ROCKET LAUNCHERS 4 Sheets-Sheet 4 Filed June 20, 1966 United States Patent 3,371,578 ROCKET LAUNCHERS Paul V. Choate, Milton, and Frank A. Spinale, Beverly, Mass., assignors to Norris Industries, Inc., Los Angeles, Calif., a corporation of California Filed June 20, 1966, Ser. No. 558,656 14 Claims. (Cl. 89-1.813)

The present invention relates to rocket launchers of the type having first and second tubular sections telescopingly connected to enable them to be extended from a shortened inoperative position into an elongated operative position.

Rocket launchers of this type are shown in Letters Patent of the United States No. 3,122,059 and No. 3,200,- 708 and in the copending application of Paul V. Choate, Charles B. Weeks, and Frank A. Spinale, Ser. No. 483,018, filed Aug. 20, 1965, now United States Patent No. 3,256,- 777, and they have proved to be well adapted to a wide range of requirements both in production and in services. The general objectives of the present invention are to provide that type of launcher with improved safety features and to provide basic constructions for use in production of launchers whether the rockets to be launched therefrom are to be ignited by percussion or electrically and also in the production of launchers for use in firing sub-caliber practice rounds.

In accordance with the invention, the first of these general objectives is attained with a rocket launcher of the above generally indicated type having a first rigid member attached to the breech end of the first tubular section, which receives the rocket, and overlying the second tubular rocket section into which the first section is telescopingly fitted. Such a rocket launcher has means interlocking the sections when the launcher has been extended into its operative position. The means to tire a rocket positioned within the first launcher section include a second rigid member which is the firing member and is movable relative to the first section between a rearward firing position and a forward cocked position and a firing spring tensioned by movement of the firing member into its cocked position. The two members have interengaged means to cause their movement together relative to the first section as the launcher is extended. The firing means also includes trigger means releasably connecting the firing member to the second section when only a predetermined further short relative movement of the sections is required to establish the operative rocket position thereby to tension the spring. In accordance with the invention, the interengaged means also remain operative during the above referred-to short relative movement until released by the safety.

The second of the general objectives of the invention may be attained with a rocket of the above described type desirably but not necessarily having the above referred-to safety features with certain structural features such that it may be completed for use with rockets requiring percussion ignition or, with the addition of a magneto, for use with rockets requiring electrical ignitions. When the launcher is to be used with sub-caliber rockets, a suitable smaller tubular section is supported within the first launcher section. In launchers providing electrical ignition, the magneto is operative to effect the rockets ignition only during the short relative movement of the members attendant the release of the firing member from its cocked position. When a sub-caliber rocket is to be thus ignited, the magneto is housed in the space intermediate the smaller tubular section and the first launcher section.

In the accompanying drawings, there is shown an illus trative embodiment of the invention from which these and other of its objectives, novel features, and advantages will be apparent.

3,371,578 Patented Mar. 5, 1968 In the drawings:

FIGURE 1 is a partly sectioned side view of a launcher in its extended position,

FIGURE 2 is a side elevation with the launcher in its shortened position,

FIGURE 3 is an enlarged fragmentary section showing the relation of certain of the parts in the FIGURE 1 position of the rocket launcher,

FIGURE 4 is a similar view showing the relation of those parts in the FIGURE 2 position of the launcher,

FIGURE 5 is a considerably enlarged view of certain of the parts shown in FIGURE 3 but with the safety moved into the firing position,

FIGURES 6, 7, and 8 are sections taken, respectively, along the indicated

lines

66, 77, and 8-8 of FIG- URE 5,

FIGURE 9 is an enlarged longitudinal section of the rear part of the launcher in the FIGURE 1 position thereof, and

FIGURE 10 is a view of the launcher as seen from the rear in FIGURE 9.

The launcher illustrated by the drawings has a first or rear tubular section 10 slidable in a second or forward tubular section 11 so that it may be extended from its shortened, inoperative position, see FIGURE 2, into its elongated, operative position illustrated by FIGURE 1.

At the exposed or breech end of the first section 10 there is a shoulder 12 to which a mount 13 is attached. The mount 13 carries an open-ended chamber 14 and has a forwardly opening chamber 15 having a retainer 16 and is shown as also having a rearwardly opening pocket 17 placed in communication with the chamber 15 by a bore 18 and so closed by a detachable member 19 as to retain the primer of an igniter in the pocket 17. Such' an igniter is not shown but the structure just described enables the launcher, as thus far described and various other parts later to be described, to be used with rockets requiring percussive ignition as well as with the launcher embodiment herein detailed providing for electrical rocket ignition.

The mount 13 supports the rear end of a rigid member 20, shown as a channel, spaced from the first section 10 to overlie the second section 11 and extending forwardly into the housing 21 with which the second section 11 is provided and which is shown as extending from end-to-end thereof with its rear part 21A being an enlarged chamber. A trigger 22 is pivotably mounted as at 23 within the chamber 21A. Forwardly of the pivot 23, the trigger 22 has a finger contact 24 protruding upwardly through a chamber opening 25 and under a protective, flexible boot 26. Rearwardly of the pivot 23, the trigger 22 has a pair of laterally spaced sears 27 yieldably urged downwardly against the member 20 by a U-shaped spring 28 within and backed by the chamber 21, the spring 28 engaging the trigger 22 rearwardly of the pivot 23 and hence also yieldably urging the finger contact 24 upwardly into the holding position shown in the drawings.

The forward end of the member 20 is reinforced at 29, the reinforcement slidably engaging the second launcher section 11 in a zone underlying the chamber 21A in the operative position of the launcher. A safety 30 is slidably supported by the member 20 within the chamber 21A and has a pull rod 31 extending forwardly through a seal 32 at the front end of the chamber 21A. The exposed end of the pull rod 31 carries a finger grip 33.

The member 20 slidably supports a generally indicated firing member 34 and shown as consisting of a rearward section 35 and a forward section 36, connected by a joint generally indicated at 37 and detailed in FIGURE 6. It will be noted that the section 35 is dimensioned to be straddled by the sears 27 while the section 36 is sufficiently wider so that its rear end provides shoulders 38 engageable by the sears 27.

The joint 37 facilitates assembly and is effected by providing the rearward section 35 of the firing member 35 with a reverse bend 35A rearwardly of its forward end which terminates in a downturned hook 35B. The rear part of the forward section 36 has a transverse slot 36A in a reverse bend through which the forward end of the section 35 extends and, forwardly thereof, a transverse slot 36B receiving the hook 353.

The rear end of the section 35 of the firing member is the firing pin portion 35C dimensioned to extend through the bore 18 and into the pocket 17 in the firing position of the firing member 34. The section 35 has a flange 39 within the chamber of the mount 13 confining a coiled compression spring 40 between it and the retainer 16 and a coiled spring 41 between the flange 39 and the opposite end of the chamber 15, the spring 40 being the firing spring and the spring 41 being weaker and serving as a cushion to position the firing member, after being driven rearwardly of the spring 40, forwardly out of the pocket 17 and into the position relative to the member 20 shown in FIGURE 2.

The forward end of the section 36 of the firing member 34 terminates short of the member 20. A latch 42 is connected to the member 20 by a transverse pivot 43 and is shown as entrant of a slot 44 in the firing member section 36 which overlies a slot 45 in the member 20 and its reinforcement thus to interconnect the

members

20 and 34. By this arrangement, extension of the rocket launcher towards its operative position results in the member 20 and the firing member 34 moving together relative to the second section 11 until only a short relative movement between the launcher sections is required to establish the operative position of the launcher, the sears 27 of the trigger 22 then engaging the shoulder 38 thereby to so connect the firing member 34 to the second section 11 as to cause it to move relative to the first section 10, the firing spring 40 being tensioned during such short relative movement. It will be noted that the slot 44 is sufficiently longer than the slot 45 to permit such relative movement with the latch 42 in its operative position into which it is urged by the rear part of a spring 46 anchored to the member 20 and extending forwardly to underlie the resilient lock 47 which is con nected to the member 20. The housing 21 of the second section 11 has a lengthwise slot 48 covered by a boot 49 and adapted to receive the lock 47 under the influence of the spring 46 when the launcher has been extended into its operative position thereby to lock it thus to hold the firing member 34 in its cocked position.

It will be noted that the latch 42 has a central part 42A so dimensioned as to be a sliding fit in the housing 21 and in the forward part of the slot A extending lengthwise of the bottom of the safety 30. With the safety 30 operatively positioned, the latch 42 cannot move out of the slots 44 and 45. The safety 30 has a rearwardly disposed cross plate 30B having a centrally located, transverse slot 30C. The latch 42 has a rearwardly and upwardly disposed arm 42B located forwardly of the cross plate 30B so that when the safety 30 is pulled forwardly from its operative into its inoperative position thereby to arm the launcher, the cross plate 30 engages the arm 42B and swings the latch 42 upwardly, the rear part of the slot 30A being dimensioned to permit such movement, until the point 42C is entrant of the slot 30C which thus functions as a detent for the safety 30.

If the trigger 22 is now actuated the firing member 34 is released and driven rearwardly by the spring 40 with the firing pin portion 350 entering the primer pocket 17 and then being returned by the cushioning spring 41 to the position shown in FIGURE 1. It will be noted additionally that the safety 30 can be returned to its operative position and during its return, it will reseat the latch 42 in its operative position even if h p g 46 should fail- 4' 7 Should the lock 47 fail or be released, the latch 42 again locks the firing member 34 to the member 20.

While the front and rear sights, indicated generally at 50 and 51, respectively, form no part of the present invention, they are, of course, essential to accuracy in the use of the launcher. The front sight 50 is shown as pivoted at 52 within the front end of the housing 21 below an elongated port 53. The sight 50 is biased by a spring 54 to swing forwardly and upwardly through the port 53 into an erect operative position. In the shortened or inoperative position of the launcher, the front sight St) is held down by the lock 47 which then overlies it.

The rear sight 51 is pivotably connected as at 55 to the rear end of the housing part 21A so that it may be swung between an inoperative, rearwardly disposed position parallel to the launcher axis and an erect position of use in which it is at right angles thereto. In the inoperative position of the launcher, the rear sight 51 is slidably confined within the housing 14 but it is biased towards its erect position by a spring 56 thus to be self-erecting when freed therefrom.

From the foregoing, it will be apparent that when the launcher is extended into its operative position, it is cocked and its sights automatically erected so that it is ready for use upon the release of the safety 30.

It is desirable that the ends of the launcher be closed until it is to be used, particularly when a rocket is to be carried therein and the means for so doing are shown but they form no part of the present invention and are shown in more detail in United States Letters Patent No. 3,122,059. In practice, a cover 57 is seated against the muzzle end of the launcher section 11. The cover 57 has a yoke ,58 pivotably secured thereto in diametrically spaced zones and dimensioned to straddle the muzzle end of the launcher. The yoke 58 is connected to a strap 59 which is joined to a hook 60 by a resilient section 61. An adjustable carrying strap 62 is also connected to the yoke 58 and the hook 60.

At the rear end of the launcher section 11, there is a collar 63 having an arm 64 pivotably connected thereto. The arm 64 extends at right angles to and is joined to a cover 69 for closing the breech end of the section 10 when the launcher is in its shortened inoperative position. The cover 69 has a slotted tab through which the projection 71 on the member 19 extends when the cover 69 is in its closed position, the projection 71 having a transverse bore to receive the keeper pin 72. The junction of the arm 64v and the cover 69 is formed to provide a shoulder 73 for the hook 60. With the end covers 57 and 69 in place, the strap 59 holds the launcher in its inoperative position. When the launcher is to be used, the pin 72 is withdrawn and the cover 69 then tilted rearwardly and the strap 66 and the front cover 57 fall free of the launcher.

The rocket launcher, as thus far detailed, has been described primarily as for use with primer-ignited rockets and its construction is in general similar to that shown in the above referred-to co-pending application with the exception of the important feature that the launcher may be cocked without disengaging the latch 42 from the member 34 and with the exception of the reinforcement of the member 20 throughout the length of the chamber 21A.

In the embodiment of the invention shown in the drawings, the launhcer is shown as for use in firing sub-caliber rockets and particularly those of the type requiring electrical ignition.

To that end, a tubular member 74 of a caliber substantially smaller than that of the section 10 is supported eccentrically therein but with its axis in a vertical plane inclusive of the axis established by the

sights

50 and 51 by

discs

75, 76, and 77 anchored to the section 10 by countersunk screws 78. While the number 74 is shown as somewhat longer than the section 10, its length is, of course, less than that of the launcher in its shortened,

inoperative position. The rear face of the disc 75 is recessed at 79 and has an insulated conductor 80 extending through it. The disc 75 is of stock that is a conductor of electricity while the tubular member, like the sections and 11, is a non-conductor thereof. A holder 81, also insulated from the disc 75 is connected to the conductor 80 and makes contact with a coil spring 82 connected to the rear end of the rocket 83 positioned in the tubular member 74 to effect the ignition thereof. By this arrangement, rearward movement of the rocket 83 is prevented while the spring 82 yields readily when it is fired. A ring shaped retainer 84 is a friction fit on the rear ends of the fins 85 of the rocket 83 and its outside diameter is greater than that of the bore of the tube 74 so that unwanted forward movement of the rocket 83 is prevented although the retainer 84 is readily dislodged when the rocket is ignited. The fins 85 are encircled by a band 86 to ensure electrical contact with a contact 87 extending through the wall of the member 74 to complete the ignition circuit through the disc 75.

The disc 76 has a rearwardly disposed flange 88 to which is anchored the supporting arm 89 of the frame 90 of a magneto, generally indicated at 91 and of the type having a slidable actuator 92 provided with an axial bore 93 intersected by a lengthwise slot 94 as may be seen in FIGURE 8. A slide 95 in the bore is connected to the end of the member 96 by a pin 97 extending through the slot 94. A spring 98 in the closed end of the bore 93 engages the slide 95. A bell crank 99, pivoted as at 100 to the frame arm 89, is pivotably connected to the actuator 92 and holds its spring 101 against the frame 90. When the actuator is moved to compress the spring 101, movement of the pin 97 is resisted by magnetic opposition to movement of the member 96 so that the spring 98 becomes compressed by movement of the actuator 92 relative thereto to the extent permitted by the slot 94. As further movement of the actuator is in direct contact with the pin 97, it forcibly releases the member 96 with the spring 98 being then operative to drive it through a pulse generating stroke and to seat the pin 97 at the other end of the slot 94. This position of the actuator 92 is to be regarded as its cocked position and if the actuator 92 is driven in the opposite direction, the spring 101 drives the actuator 92 to produce an opposite pulse when the slide 95 and the actuator 92 move together to overcome the magnetic resistance to movement of the member 96.

In accordance with the invention, the disc 76 slidably supports an actuating rod 102 connected to the bell crank 99 by a link 103. The rod 102 has, at its front end, a fork 102A providing a shoulder 104 and closed by a pin 105 at its outer end to provide a second shoulder spaced therefrom to receive between them a depending part 106 carried by the forward section 36 of the firing member 34, the shoulders 104 and 105 being spaced apart to enable the finger 106 to have short movement relative thereto in the cocked position of the member 34. The part 106 extends freely downwardly through a slot 107 in the reinforced end of the member 20, the

slot 107 being of sufiicient length to permit the short relative movement between the members and 24 necessary to efiect the cocked, operative position of the launcher and downwardly through registering

slots

108 and 109 in the sections 10, 11, respectively, the slot 109 being long enough to accommodate the part 106 in both launcher positions. With this construction, when the launcher is extended into its operative position, the actuator 92 of the magneto 91 is driven into and held in its cocked position with the depending part 106 in engagement with the shoulder 105. When the firing member 34 is released by actuating the trigger 24, the finger 104 strikes the shoulder 105, after short movement relative thereto, and drives the actuator 92 to deliver a pulse adequate to ignite the rocket via a magneto lead 110 which is connected to the conductor 80.

With the magneto 91, shown in the drawings, a pulse is generated in either direction in which the actuator 92 is moved. It is, of course, essential to avoid the firing of the rocket 83 in response to the pulse generated during the extension of the launcher into its operative position. While such prevention may be variously effected, there is shown a ground lead 111 connected to the magneto 91 and including a switch 112 of the normally open type and held closed by an arm 113 with which the latch 42 is provided and which extends downwardly through a slot 114 in the reinforced end of the member 20. It will be apparent that when the safety 30 effects the disengagement of the latch 42, it is so pivoted that the arm 113 is so moved as to permit the switch 112 to open.

From the foregoing, it will be apparent that rocket launchers in accordance with the invention can be made for percussion or electrical ignition and that a sub-caliber embodiment can be made to enable practice rounds to be used in a launcher otherwise identical as to its preparation for use. For use, a launcher with a sub-caliber round should not only operate in the same manner as the launcher to be used in combat, but also it should have the same weight and when live practice rounds are to be used, they should have approximately the same range and velocity as the combat rounds. To that end, a subcaliber launcher needs the addition of weight because the practice round is substantially smaller than the round designed for combat use. While such weight can be added where desired, the

discs

75, 76, and 77 may be used advantageously for this purpose as they enable added weight to be evenly distributed.

We claim:

1. In a rocket launcher, first and second tubular sections telescopingly connected to enable said launcher to be extended from a shortened, inoperative position into an elongated, operative position, one end of said first section being the breech end of the launcher, said first section fitting within said second section, said first section including a first rigid member overlying said second section, said second section and said first member including portion releasably interengaged in said operative position, and means to fire a rocket positioned in said first launcher section, said means including a second rigid member which is the firing member and is movable relative to said first section between a rearward firing position and a forward cocked position, a firing spring tensioned by movement of said firing member into said cocked position, said members including means interengaged to cause their movement together relative to said second launcher section as said launcher is extended and trigger means releasably connecting said firing member to said second section when only a predetermined short further relative movement of said sections is required to establish said operative position, said interengaged means providing for corresponding short movement of the firing member relative to the first member whereby said spring becomes tensioned during said short relative movement, and a safety operable to disengage said interengaged means.

2. The rocket launcher of claim 1 in which interengaged means includes a latch pivoted to the first memher, the second member overlies the first member, the members have lengthwise slots through which the latch extends in engagement with their leading edges, the leading edges of the slots registering except during the short relative movement, the slot of the second member is dimensioned to provide that such relative movement be also relative to the latch, and the safety is operable, when moved from its operative position, to release the latch.

3. The rocket launcher of claim 2 in which the first member includes a reinforcement slidable on the second launcher section and extending from the area of the interengaged means through the latch area.

4. In a launcher for a rocket of the electrically ignited type, first and second tubular sections telescopingly connected to enable said launcher to be extended from a shortened, inoperative position into an elongated, operative position, one end of said first section being the breech end of the launcher, said first section fitting within said second section, said first section including a first rigid member overlying said second section, said second section and said first member including portions releasably interengaged in said operative position, and means to fire a rocket positioned in said first launcher section, said means including a second rigid member which is the firing member and is movable relative to said first section between a rearward firing position and a forward cocked position, a firing spring tensioned by movement of said firing member into said cocked position, said members including means interengaged to cause their movement together relative to said second launcher section as said launcher is extended until a predetermined short further relative movement of said sections is required to establish said operative position, and trigger means releasably connecting said firing member to said second section to move therewith relative to the first member during said short relative movement thereby to tension said spring, and magneto powered means to deliver an electric charge to a rocket when positioned in said first launcher section, said means including a connection with said firing member and being operable to deliver said charge only when said firing member is released from its cocked position.

5. The rocket launcher of claim 4 and means including a safety movable into and out of a position in control of said trigger means and rendering said charge delivering means inoperable when the safety is in control of said trigger means.

6. The rocket launcher of claim 4 in which the interengaged means includes a latch pivoted to the first member and normally interconnecting the second member thereto, the charge delivering means includes a switch whose position is controlled by said latch, the latch effects the closed position of the switch when interconnecting the members, and a safety operable to pivot the latch into a member-releasing position when the safety is moved from its safe position, the latch then effecting the open position of the switch.

7. The rocket launcher of claim 4 in which charge delivering means includes a magneto and the connection with the firing member is of a lost-motion type thereby providing acceleration of the firing member by the firing spring before its actuation of the magneto.

8. In a launcher for a rocket, first and second tubular sections telescopingly connected to enable said launcher to be extended from a shortened, inoperative position into an elongated, operative position, one end of said first section being the breech end of the launcher, said first section fitting within said second section, said first section including a first rigid member overlying said second section, said second section and said first member including portions releasably interengaged in said operative position, and means to fire a rocket positioned in said first launcher section, said means including a second rigid member which is the firing member and is movable relative to said first section between a rearward firing position and a forward cocked position, a firing spring tensioned by movement of said firing member into said cocked position, said members including means interengaged to cause their movement together relative to said second launcher section as said launcher is extended until a predetermined short further relative movement of said sections is required to establish said operative position, and trigger means releasably connecting said firing member to said second section to move therewith relative to the first memher during said short relative movement thereby to tension said spring, and an insert in said first section including a rocket-receiving tubular section of a diameter substantially less than that of the first section and of a length less than that of the launcher in its inoperative position, and means supporting said rocket-receiving section and attached to said first section.

9. The rocket launcher of claim 8 in which the axis of the rocket-receiving section is eccentric with respect to the axis of the first section but is in a vertical plane inclusive thereof.

10. The rocket launcher of claim 8 in which the rocket is of the electrically ignited type, and the magneto powered means are mounted on said insert and located in the space between the first and the rocket-receiving sections, the magneto powered means including a conductor disposable in electrical contact with a rocket in the rocketreceiving section and a mechanical connection with the firing member and the magneto powered means is operable to deliver a firing charge only when the firing member is released from its cocked position.

11. The rocket launcher of claim 10 in which the sec ond section has a chamber extending lengthwise thereof, the first and second sections have registering slots opening into the chamber through which the connection extends, and the slot in the second member is of a length to enable the launcher to be extended from its shortened to its operative position.

12. The rocket launcher of claim 10 in which the connection between the magneto powered means and the firing member includes an axially movable rod, a depending part attached to the firing member projects downwardly into the space between the rocket-receiving and first sections, and the rod and the depending part have limited relative movement when the firing member is in its cocked position.

13. The rocket launcher of claim 12, in which the supporting means of the insert are axially spaced members, the magneto of the magneto powered means is attached to one of the members and the rod is slidably supported thereby.

14. The rocket launcher of claim 13 in which the magneto includes a transversely movable actuator, and a bell crank and a link operatively connected to the actuator and the rod, respectively.

No references cited.

SAMUEL W. ENGLE, Primary Examiner.

Claims

1. IN A ROCKET LAUNCHER, FIRST AND SECOND TUBULAR SECTIONS TELESCOPINGLY CONNECTED TO ENABLE SAID LAUNCHER TO BE EXTENDED FROM A SHORTENED, INOPERATIVE POSITION INTO AN ELONGATED, OPERATIVE POSITION, ONE END OF SAID FIRST SECTION BEING THE BREECH END OF THE LAUNCHER, SAID FIRST SECTION FITTING WITHIN SAID SECOND SECTION, SAID FIRST SECTION INCLUDING A FIRST RIGID MEMBER OVERLYING SAID SECOND SECTION, SAID SECOND SECTION AND SAID FIRST MEMBER INCLUDING PORTIONS RELEASABLY INTERENGAGED IN SAID OPERATIVE POSITION, AND MEANS TO FIRE A ROCKET POSITIONED IN SAID FIRST LAUNCHER SECTION, SAID MEANS INCLUDING A SECOND RIGID MEMBER WHICH IS THE FIRING MEMBER AND IS MOVABLE RELATIVE TO SAID FIRST SECTION BETWEEN A REARWARD FIRING POSITION AND A FORWARD COCKED POSITION, A FIRING SPRING TENSIONED BY MOVEMENT OF SAID FIRING MEMBER INTO SAID COCKED POSITION, SAID MEMBERS INCLUDING MEANS INTERENGAGED TO CAUSE THEIR MOVEMENT TOGETHER RELATIVE TO SAID SECOND LAUNCHER SECTION AS SAID LAUNCHER IS EXTENDED AND TRIGGER MEANS RELEASABLY CONNECTING SAID FIRING MEMBER TO SAID SECOND SECTION WHEN ONLY A PREDETERMINED SHORT FURTHER RELATIVE MOVEMENT OF SAID SECTIONS IS REQUIRED TO ESTABLISH SAID OPERATIVE POSITION, SAID INTERENGAGED MEANS PROVIDING FOR CORRESPONDING SHORT MOVEMENT OF THE FIRING MEMBER RELATIVE TO THE FIRST MEMBER WHEREBY SAID SPRING BECOMES TENSIONED DURING SAID SHORT RELATIVE MOVEMENT, AND A SAFETY OPERABLE TO DISENGAGE SAID INTERENGAGED MEANS.