Fin Mount Latch

Abstract

The subject invention provides a latching mechanism particularly suitable for mounting a stabilizing fin on an external engine missile. Generally, the invention relates to spring-biased, cam-operated latches and more particularly to a positive-locking latch device in which a circular-band spring biases locking pins into retaining holes in a fairing or shroud for locking a fin on a missile. The latch is released by rotating a cam actuator which contacts the locking pins and withdraws them from the retaining holes, when the fin may be removed from the missile.

Description

BACKGROUND AND BRIEF SUMMARY OF THE INVENTION

Space restrictions imposed on various augmented thrust missile designs have necessitated external engine geometries which prevent the use of normal control surface attachment mechanisms. The present invention provides simple, effective means for attaching control surface/actuator packages, with control surfaces thereon, to a missile having externally mounted engines. A saddle-type mounting is utilized which straddles each external engine. That is, a control box for each control surface forms a portion of the saddle mounting, said mounting including legs which straddle portions of the engine and are attached to fairings or shrouds along the missile by double-acting, positive-locking latches.

Use of the present invention allows rapid and facile installation of a control surface package on a missile by one person with the use of but a simple spanner wrench.

The latch disclosed herein finds utility in any number of applications. Such a simple, easily operated, yet effective latching device can readily be used with success as a car trunk latch, a tool cabinet latch, or a door lock.

It is therefore an object of the present invention to provide a latch for mounting control surfaces and related actuating devices on a missile utilizing external engines.

It is also an object of the invention to provide a positive-locking latch capable of providing rapid attachment of a stabilizing surface package to a missile body.

A further object of the invention is to provide simple, effective latching means for attachment and detachment of a control package to and from a missile and which is readily operable by one person without special equipment.

A still further object of the invention is to provide easily operable latching means which is also suitable for general use as a lock, catch, or stay.

Further objects and attendant advantages of the invention will become more readily apparent in the light of the following description of a preferred embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective of a saddle-type control surface mounting utilizing the double-acting, positive-locking latch of the present invention, the mounting being shown prior to attachment to an external engine missile;

FIG. 2 is a side elevation of a portion of the aft section of an external engine missile showing a control surface surmounting one of the external engines and attached to the body of the missile by the double-acting, positive-locking latch of the present invention, the latch being shown in broken lines;

FIG. 3 is a section, partly broken away, on the line 3--3 of FIG. 2;

FIG. 4 is an enlarged detail axial section of the latch of the present invention;

FIG. 5 is a plan view of the latch, shown in partial section and with the latch pins extended, and

FIG. 6 is a view similar to FIG. 5 but showing the latch pins retracted.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Launcher size and storage restrictions have required the development of external engine missiles for thrust augmentation. Such a missile requires unique means for suitably mounting control surfaces on its body. In FIG. 1, a control surface mounting unit is shown generally at 1, prior to its attachment to the body 3 of a missile having externally mounted engines 5. As can be seen in FIGS. 1, 2, and 3, the control surface mounting unit 1 comprises a control fin 7 which is permanently mounted on a control surface actuator package 9, the package 9 having a saddle-like body portion 11 with spaced legs 11a. When fitted to the missile body 3, legs 11a of the saddle-like body portion 11 straddle one of the externally mounted engines 5. The body portion 11 is intended to fit into a cutout 13 in a raised engine fairing or shroud 15, the body portion 11 having inclined surfaces 17 which fit flush against surfaces 19 of said shroud.

A latch 21 is disposed in each leg 11a of the body portion 11 and, in a manner to be more fully described hereinafter, secures the control surface mounting unit 1 to the shroud 15 and thus to the missile body 3. Latch pins 23 are seated in retaining holes 25 located in the shroud 15 by a circular spring 27. Two of the latches 21, one located in each leg of the body portion 11, are utilized for mounting each unit 1 on the missile body.

Installation of the actuator package 9 may be readily accomplished by one person. As the legs of the body portion 11 of the package 9 are moved into the cutout portion 13, end walls 19 of the shroud 15 will engage the latch pins 23 of the latches 21 and bias them inwardly until said pins confront the holes 25, when the pins will be urged into said holes by the spring 27. The unit 1 will thus be mounted in the cutout 13 with the legs of the portion 11 flush with the walls of the shroud 15.

In FIGS. 2 and 3, the control surface mounting unit 1 is shown fastened to the shroud 15 on the missile body 3. FIG. 3 particularly illustrates how the unit straddles the engine 5 to locate the control fin 7 and actuator package 9 in non-obstructive relation with respect to said engine.

The structure and operation of the latches 21 may be more clearly understood by reference to FIGS. 4, and 6. Each latch 21 is comprised of mating discs 31a and 31-b, the two opposed latch pins 23, and the circular spring 27 and is encased in one of the legs of the previously described saddle-like portions 11.

The latches 21 in the legs of the saddle-like portion 11 comprise housings 22 which define cam actuators rotatable in said legs for retracting their respective latch pins 23. The housings 22 are each comprised of a pair of the mating discs 31a and 31-b which have flat outer surfaces and elliptical recesses in their inner surfaces. Since the discs 31a and 31-b are virtually identical, a detailed description of one of them will suffice. Accordingly, as best seen in FIGS. 4 and 5, the recess in the disc 31a is bounded by a flange 35 which has a circular outer rim and an elliptical inner wall 32. A hub 37 is mounted in the center of the disc 31a and cooperates with a similar hub on the disc 31-b, screws 45 being employed for retaining the discs in cooperating relationship.

When joined as described above, the discs provide an enclosed elliptical cavity 53 having an annular slot 54. The circular spring 27 is disposed within the enclosed cavity 53 and is of a diameter slightly smaller than the minor axis of said elliptical cavity.

The latch pins 23 are formed with spaced annular flanges 55 which impinge on the inner surfaces of cylindrical bores 57 formed in the portion 11, and with rounded outer ends which readily fit into the retaining holes 25 in the shroud 15, as shown in FIGS. 1 and 2. Corresponding inner end portions of the pins 23 extend through the slot 54 into the elliptical cavity 53 and have enlarged heads 63 which have sliding engagement with the elliptical wall 32. Corresponding inner end faces of the heads 63 contact the circular spring 27. Normally, the spring 27 maintains a circular configuration and simply retains the pins 23 in engagement with the elliptical inner wall 32 of the cavity 53. However, as previously described, movement of the legs of the actuator package 9 into position in the cutout portion 13 will increase pressure on the rounded outer ends 65 of the latch pins 23, causing them to move toward each other in the bores 57 in the body portion 11 and to deform the circular spring 27, thus causing said spring to exert a force against said pins. As long as an external pressure greater than or equal to the force is exerted by the spring is maintained, the pins 23 will remain inside the bores 57. On release of such external pressure, as when the pins confront the retaining holes 25, said pins 23 will snap into positions with their rounded ends 65 extending into said holes. The unit 1 is thus mounted on the body of the missile.

Referring particularly to FIG. 5, the disc 31a of the housing 12 has circular sockets 67 disposed in its surface to receive the jaws of a spanner wrench (not shown) for detaching the unit 1 from the engine 5, the flat outer surface of the disc being flush with the exterior surface of the body portion 11. More specifically, when the jaws of a spanner are inserted in the sockets 67 and the housing 12 is rotated in either direction, the elliptical walls 32 of the cavity 53 cam the enlarged heads 63 of pins 23 inwardly toward the center of the housing, thereby deforming the circular spring 27 and biasing the latch pins 23 to a position where the rounded ends 65 are drawn inside the bores 57 in the body portion 11 and from the retaining holes 25 in the shroud 15. In such position, the unit 1 may be lifted free of the missile body. Removal of the tool allows the latch pins to be moved back to their original positions, by action of the spring 27. The unit 1 may be easily remounted on the missile body, when desired, thus providing ground testing of latching effectiveness.

The snap-action latch of the present invention is not limited to the environment described. The utility of this simple, yet effective latching device causes it to be applicable to any number of uses requiring a positive locking latch. For example, the latch could be easily modified to provide a car trunk latch operable either by closure of the trunk door or by operation with a normal key.

Claims

I claim:

1. In combination with a missile having an externally mounted engine, and a shroud on the engine and having a cutout therein,

a control surface mounting unit having a body portion with spaced legs,

walls defining the cutout and having retaining holes therein,

a latch in each of the legs for detachably mounting the control surface mounting unit in the cutout with the legs straddling the engine, and

pins in the latches and having end portions thereof engageable in the retaining holes for securing the control surface mounting unit on the engine.

2. The invention as recited in claim 1, wherein the latches each include a housing rotatable in a leg,

and a spring in the housing and urging the latch pins into engagement in the retaining holes.

3. The invention as recited in claim 2, wherein the housing has an elliptical wall and wherein the latch pins have heads engaging said spring and said elliptical wall, whereby upon rotation of the housing said latch pins by cam action of the wall on the heads will be withdrawn from the retaining holes to permit withdrawal of the control surface mounting unit from the cutout.

4. The invention as recited in claim 2, wherein the housing includes a pair of mating discs having an elliptical wall defining an elliptical cavity, and an annular slot communicating between the cavity and the exterior of the housing, said slot receiving corresponding inner end portions of the latch pins.

5. In combination with a missile having an externally mounted engine and a shroud on the engine and having a cutout, said cutout having walls formed with retaining holes,

a control surface mounting unit having an actuator package and a control fin and having a body portion with walls and spaced legs,

means for detachably mounting the control surface mounting unit in the cutout with the spaced legs straddling the engine and the walls of said unit engaging the walls of the cutout,

said means comprising a latch mounted in each of said legs,

each said latch comprising a housing, a pair of opposed latch pins, and a spring in the housing and urging the latch pins to engage in the retaining holes,

said housing having a cam surface engageable with portions of the latch pins and being rotatable for disengaging end portions of said latch pins from the retaining holes.