US3086481A - Restraining latch - Google Patents

Description

April 23, 1963 H. HIMMELBERGER ETAL 3,086,481

' RESTRAINING LATCH Filed May 21, 1962 2 Sheets-Sheet 1 FIG. 1 FIG. 2

INVENTOR Harold Himme/berger Donald K. Adrian BY W ATTORNE Y April 23, 1963 H. HIMMELBERGER ETAL 3,086,481

RESTRAINING LATCH Filed May 21, 1962 2 Sheets-Sheet 2 United States Patent 3,086,481 RESTRAINING LATCH Harold Himmelberger, Silver Spring, and Donald K. Adrian, Damascus, Md., assignors to the United States of America as represented by the Secretary of the Navy Filed May 21, 1962, Ser. No. 196,536 10 Claims. (Cl. 104-250) This invention relates to a latch and more particularly to a restraining latch for restraining a missile in the event of accidental ignition, one object of the present invention being the provision of a more useful device of this nature.

The invention is admirably adapted for restraining a missile during depot check-out of the missile components, but is of course applicable for numerous other uses.

Many of the devices heretofore used as restraining latches, for one purpose or another, comprise cam actuation or detent locking means. However, these devices failed to satisfy the present missile restraint requirements of dependability, simplicity and visual assurance of operation. Therefore, other objects of this invention are the provisions of a restraining latch which is very simple in construction, assembly, servicing, repair and operation.

A further object of invention is the provision of a restraining latch of such rugged construction as to be failure-proof in the event of missile ignition during checkout when the missile is being retained on a test stand.

Another object of this invention is the provision of a restraining latch having a visual indicator depicting the extent of latch operation.

A still further object of this invention is the provision of a restraining latch having a positive locking arrangement, quickly and easily operable.

Various other objects and advantages will appear from the following description of one embodiment of the invention, and the novel features will be particularly pointed out hereinafter in connection with the appended claims.

FIG. 1 is a side elevation view of a portion of the missile and its supporting rail with portions broken away;

FIG. 2 is a vertical sectional view taken substantially along the line 2-2 of FIG. 1;

FIG. 3 is a vertical sectional view of the retaining latch in latched condition taken substantially along the line 3-3 of FIG; 2;

FIG. 4 is a view similar to FIG. 3 showing the latch in unlatched condition, and

FIG. 5 is a transverse section taken substantially along the line 55 of FIG. 3.

A restraining latch embodying this invention, herein disclosed by way of illustration, comprises a cammed latch having a plunger which acts as a combination indicator-release mechanism to give positive visual assurance of latch engagement and to provide for a one step latch release operation which leaves the latch positioned to receive the next missile lug. However, it is to be understood that while this invention is herein described as a missile lug restraining latch for use on a depot missile test stand, the scope thereof is not limited to missiles, but may, by slight modification be adapted for performing other latching functions, such as on hatches, conveyors, and the like.

Referring to the drawings and more particularly to FIGS. 1 and 2, the restraining latch device 4 is secured to a missile support rail 7 of a missile test stand (no-t shown). The missile 5, to be tested, is supported on rail 7 by one or more lugs 6 and is moved from the left in the direction of the arrow to a correct position for testing such that the lug 6 passes by the latch device 4 and is prevented -from return motion to the left by latch stop '13. Thus in the event of accidental ignition of the 'n'iissile, stop 13. of latch device 4 restrains movement of the missile which might otherwise result in injury and damage to personnel and material in the adjacent work areas.

The restraining latch device 4 comprises a housing or support 11 of any desirable and practical shape to facilitate attachment to the test stand. The housing is provided with a bore 12 therethrough in which a latch stop or locking bolt 13 is reciprocable from an operative latching position protruding from the housing as in FIG. 3, to an inoperative unlatched position shown in FIG. 4.

The upper surface of housing 11 is covered by a plate 14 firmly attached to the housing by screws 16 and provided with a bore 17 generally concentric with bore 12 of the housing 11 and through which the upper portion 15 of bolt 13 protrudes. Bolt 13 is a two-diameter shaft having its lower portion 10 slidably fitting in the housing bore 12 and the upper portion 15 of a reduced diameter slidably fitting bore 17 of cover plate 14 and defining, therebetween, a shoulder '18. A coiled compression spring 19 surrounds the bolt in the space defined by housing bore 12, the bolt upper portion 15, cover plate 14 and shoulder 18 and acts against shoulder 18 to normally urge the bolt to its operative latching position as shown in FIG. 1.

A knob 21 is secured to the top of bolt 13- by means of threads 22 and 23 on said bolt and knob respectively, and is preferably knurled to facilitate manual grasping for lifiting bolt 13, against the bias of spring 19, to the inoperative position shown in FIG. 4. A spacing sleeve 24 is positioned around bolt 13 between plate 14 and knob 21 thereby limiting the extent of protrusion of bolt portion 10 below housing 11 in response to the urging of spring 19.

One side of the bolt lower portion 10 is provided with a surface 26 cammed in the direction of movement of missile lug 6 and facing the lug as it moves along rail 7 toward latch 4. As lug 6 encounters surface 26, bolt 13 is cammed upward into housing 11 as shown in FIG. 4.

The opposite side of the bolt lower portion is provided with a latching surface 27 perpendicular to the direction of movement of lug 6 and adjacent to the lug when missile 5 is in test posiiton, this restraining the return movement of missile lug 6. Proper alignment of bolt surfaces 26 and 27 relative to housing 11 is assured by the provision of a groove 28 along the periphery of upper portion 15 and extending from the top of bolt 13 to a point adjacent shoulder 18 in the direction of reciprocal movement of the bolt. Plate 14 is provided with a protrusion 29 which extends into groove 28 thereby preventing rotary motion of bolt 13 relative to housing 11 as best shown in FIGS. 3 and 5. It should be noted that groove 28 need extend along the length of portion 15 only far enough to permit bolt '13 to retract into housing 11 as shown in FIGURE 4.

Bolt 13 is additionally provided with an axial bore 31 extending from the top of the bolt through upper portion 15, having its axis parallel to the line of motion of bolt 13 and terminating in a shoulder 32. A second bore 33, of smaller diameter than, but concentric with bore 31, extends trom shoulder 32 into lower portion 10 of the bolt. Knob 21 also has a bore therethrough concentric with but of smaller diameter than bore 31 and, when threaded on the bolt, defines a shoulder 38 with bore 31. Bolt 13 is further provided with a transverse bore 34 in lower portion 10 which communicates with both bore 33 and the periphery of the bolt. Transverse bore 34 also communicates with a recess 36, provided in housing 11, when the bolt is in a normally extended operative position, as shown in FIGURE 3.

Carried in bores 31, 33 and '37 of the device is an indicating-locking member 41 in the form of a plunger having a top indicating section 42 slidable in bore 37 and a (it normally protruding therefrom, and an intermediate section 43 and bottom locking section 44 slidably fitting in bore 33. A collar 46 is located between top and intermediate sections 42 and 43, respectively, slidably fitting and reciprocatable within bore 31, limited in extent of movement by shoulders 32 and 38. A coiled compression spring 47 is telescoped around intermediate section 43 and acts between shoulder 32 and collar 46 to urge collar 46 toward shoulder 38 thereby causing the indicating section 42 to normally protrude from knob bore 3 7 as shown in FIGURE 3.

A reduced diameter portion 48 is located between intermediate section 43 and locking section 44 thereby defining an annular recess 51 therebetween for purposes discussed hereinafter. The interface 49 between the reduced diameter portion 48 and locking section 44 is in the form of a tapered or chamfered cam surface. It should be noted that when indicating section 42 is protruding above knob 21 and collar 46 is in abutment with shoulder 38, locking section 44 is positioned in alignment with transverse bore 34 as best seen in FIG. 3. Alternatively, when plunger 41 is retracted into bolt 13 such that indicating section 42 is flush with knob 21, recess 51 is in alignment with transverse bore 34 as best seen in FIG. 4.

Bolt locking relative to the housing is accomplished by the provision of a locking detent 55 slidably carried in transverse bore 34 and having both ends of a rounded configuration as at 52 and 53. Detent 55 is of longer length than bore 34 such that when either end of the detent is flush with an adjacent end of bore 34, the opposite rounded end of the detent protrudes from the other end of the bore. Thus, as may be readily seen in FIG. 3, when detent surface 52 is in abutment with plunger locking portion 44, detent end 53 protrudes into housing recess 36. Alternatively, when detent end 53 is in abutment with the surface of bore 12, detent end 52 extends into recess 51 as shown in. FIG. 4.

In operation, the cycle of movements may be most logically described by assuming the bolt to be in extended operative condition, as shown in FIG. 3, however, without the presence of a missile in test position. In this orientation, bolt 13 is urged to the operative position by spring 19 thus presenting cam face 26 and latch face 27 below the housing. Plunger 4-1 is urged to its uppermost position by spring 47 thus positioning locking portion 44 in alignment with the transverse bore 34 and detent 55 and detent end 53 is lodged in recess 36 thereby locking the bolt relative to the housing. It should be specifically noted that the plunger indicating section 42 extends above knob 21 thus giving visual assurance of the locked condition of the bolt. As a missile is moved along the test stand rail toward the latch device, missile lug 6 encounters bolt cam surface 26. Plunger 41 may now be manu' ally depressed against the action of spring 47 by pushing down on the indicating section thus positioning recess 51 in alignment with the transverse bore and detent. Further movement of missile lug 6 cams bolt 13 upward and similarly causes detent 55 to be cammed out of recess 36 and into recess 51, as shown in FIG. 4. It should now be noted that indicating section 42 is flush with the top of knob 21 thus giving a visual indication that bolt 13 is in an inoperative, unlatched condition. It should be further noted that manual pressure on the plunger need be maintained only long enough for detent cam face 52 to engage plunger cam surface 49. Detent surface 52 cooperates with plunger surface 49 to cam the plunger to the lower position, shown in FIG. 4, and to hold the plunger in this position relative to the bolt so long as the bolt is in an unlatched condition.

As lug 6 moves past the bolt, spring 19 urges the bolt to its extended latched position. Recess 36 is again in alignment with the transverse bore 34 and detent 55, and plunger 41 in response to the urging of spring 47 moves upward relative to the bolt, thus camming the detent into d recess 36, locking the detent therein by the alignment of locking section 44 with the transverse bore. Indicating section 42 again protrudes above the knob to visibly indicate the latched condition of the bolt.

To release missile lug 6 from its position in abutment with bolt latch face 27, plunger 41 is manually depressed while, simultaneously, knob 21 is grasped and lifted upward. The detent is cammed from engagement in recess 36 into recess 51 as the bolt is lifted, again assuming the condition shown in FIG. 4 with indicating section 42 flush with the knob. The missile with its lug 6 may now be returned from the test position along the rail past latch device 4 and upon release, the bolt, plunger and detent return to the latched condition of FIG. 3 ready to receive the next missile lug.

As may be readily ascertained hereinabove, the operator may easily make a visual determination of the bolt position without resorting to inspection of the bolt latching surface which is located in a virtually hidden position within the missile rail.

It will thus be seen that the invention accomplishes its objects and while it has herein been disclosed by reference to the details of a specific embodiment, it is understood that such disclosure is intended in an illustrative, rather than limited sense, as it is contemplated that various modifications in the construction and arrangement of the parts will readily occur to those skilled in the art, within the spirit of the invention and the scope of the appended claims.

What is claimed is:

1. A latch for holding a member having a path of movement in one of two possible directions which comprises a support relative to which said member moves, a locking element carried by said support for movement into and out of the path of relative movement of said member, means biasing said element into said path, said locking element carrying an indicating member movable in a direction parallel to the direction of movement of said locking element, bias means for urging said indicating member in the same direction as said locking element moves when moving out of the path of said member, means carried by said locking element and interacting with said support and indicating member for holding said indicating member when said indicating member is moved in a direction opposed to that of said locking element when the latter moves out of the path of said member whereby said indicating member protrudes from said locking element when said locking element is in the path of said member and the indicating member is contained within said locking element when said locking element is out of the path of said member.

2. The device as set forth in claim 1 further comprising knob means attached to said locking element and exterior to said support for manually moving said locking element out of the path of said member.

3. The device as set forth in claim 1 wherein said indicating member has cam surfaces, said means carried by said locking element being a detent having a cam surface complementary to and engageable with one of those on said indicating member, said support having a recess engageable by said detent when said locking element is in the path of said member, said detent being movable from a first position in engagement with said recess to a second position in engagement with said indicating member cam surface whereby said detent is in said second position when said locking element is out of the path of said member.

4. A latch device comprising a housing having an opening therethrough, means in said opening having on one end a latching surface, said means being movable in said opening from a first position wherein said latching surface is entirely within said housing to a second position wherein said latching surface extends outwardly from said housing, said means having a bore, a plunger mounted in said bore having one end normally extending out of said bore, said plunger being movable relative to said means in response to movements of said means whereby said plunger is contained entirely within said bore when said means is in said first position thereby indicating that said means is in said position.

5. The device set forth in claim 4 additionally comprising first bias means in said opening for urging said means to said second position, and second bias means in said bore for urging said plunger out of said bore.

6. The device set forth in claim 5 further comprising the longitudinal axis of said bore being parallel to that of said housing opening, said means having a transverse bore connecting said bore and opening and extending in a direction generally perpendicular to said bore and opening, said housing having a recess adjacent to and in alignment with said transverse bore when said means is in said second position, detent means carried in said transverse bore, said plunger having a portion of reduced diameter intermediate the ends thereof, said reduced diameter portion being alignable with said transverse bore, and said distance between said reduced diameter portion and said recess when the same are in alignment with the axis of said transverse bore being greater than the length of said detent whereby said detent is movable from a position projecting from one end of said transverse bore into said recess to a position projecting from the other end of said transverse bore into contact with said reduced diameter portion.

7. The device as set forth in claim 6 wherein said reduced diameter portion is normally held out of alignment with said transverse bore by said second bias means, and said detent means is of greater length than said transverse bore, whereby when said plunger is normally extending out of said bore said detent protrudes into said recess thereby indicating said means is in said second position.

8. The device as set forth in claim 7 wherein at least one end of said recess and adjacent end of said detent are cam surfaces, and at least one end of said plunger adjacent said reduced diameter portion and said other end of said detent are cam surfaces, whereby movement of said plunger toward said normally extended position cams said detent into said recess, and subsequent relative move ment of said housing and means cams said detent out of said recess.

9. The device as set forth in claim 8 wherein the surface of said plunger adjacent said detent is an abutment preventing movement of said detent into engagement with said reduced diameter portion when said plunger is in said normally extended position whereby said detent is held in said recess thereby locking said means in said second position.

10. The device as set forth in claim 9 wherein said abutment surface on said plunger is movable out of engagement with said detent when said plunger is moved from said normal extended position against said bias means into said bore whereby said detent is movable from engagement in said recess into engagement with said reduced diameter portion thereby permitting said means to move to said first position.

References Cited in the file of this patent UNITED STATES PATENTS 1,867,678 Rayburn July 19, 1932

Claims (1)

1. A LATCH FOR HOLDING A MEMBER HAVING A PATH OF MOVEMENT IN ONE OF TWO POSSIBLE DIRECTIONS WHICH COMPRISES A SUPPORT RELATIVE TO WHICH SAID MEMBER MOVES, A LOCKING ELEMENT CARRIED BY SAID SUPPORT FOR MOVEMENT INTO AND OUT OF THE PATH OF RELATIVE MOVEMENT OF SAID MEMBER, MEANS BIASING SAID ELEMENT INTO SAID PATH, SAID LOCKING ELEMENT CARRYING AN INDICATING MEMBER MOVABLE IN A DIRECTION PARALLEL TO THE DIRECTION OF MOVEMENT OF SAID LOCKING ELEMENT, BIAS MEANS FOR URGING SAID INDICATING MEMBER IN THE SAME DIRECTION AS SAID LOCKING ELEMENT MOVES WHEN MOVING OUT OF THE PATH OF SAID MEMBER, MEANS CARRIED BY SAID LOCKING ELEMENT AND INTERACTING WITH SAID SUPPORT AND INDICATING MEMBER FOR HOLDING SAID INDICATING MEMBER WHEN SAID INDICATING MEMBER IS MOVED IN A DIRECTION OPPOSED TO THAT OF SAID LOCKING ELEMENT WHEN THE LATTER MOVES OUT OF THE PATH OF SAID MEMBER WHEREBY SAID INDICATING MEMBER PROTRUDES FROM SAID LOCKING ELEMENT WHEN SAID LOCKING ELEMENT IS IN THE PATH OF SAID MEMBER AND THE INDICATING MEMBER IS CONTAINED WITHIN SAID LOCKING ELEMENT WHEN SAID LOCKING ELEMENT IS OUT OF THE PATH OF SAID MEMBER.

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