US3124012A - Rotary drive multiple position latch - Google Patents

Description

I March 10, 1964 R. F. HE-RETH ETAL 3,124,012

ROTARY DRIVE MULTIPLE POSITION LATCH Filed March 2, 1962 v INVENTORS PHLPH F HEEZ'TH 650 FIG. 3

United States Patent RQTARY DRIVE MULTlPLE PGSITION LATCH F. llereth, PortOrcliard, and George M. Sherman,

Breme'rton, Wash, assign ors to the United States of America as represented by the Secretary of the Navy Filed Mar. 2,1962, Ser. No. 177,714 4'Claimfs. (Cl. 74-527) (Granted under Title 35, US. Code (1952), see. 266) The invention described herein may be manutactured and used by or for the Government of the United States of America for governmental purposes Without the payment of any royalties thereon'or therefor.

The present invention relates to latch mechanism and, in particular, to mechanisms for latching rotary members in multiple rotated positions.

Generally considered, a principal object of the invention is to provide a multiple position latch for securing a rotary driving or driven shaft in any number of preselected positions.

Another more specific object is to provide such a multiple position latch for securing the train and elevation drive shafts Otf a particular lguided'missile launcher system which'will be broadly described.

Still another object is to provide a self-latching rotary drive such as obviates the need for securing the drive by the more conventional means of extending latch pins or the like into physical inter-engagement with relatively stationary members.

A further object is to provide a rotary drive multiple position latch that is functionally related to the drive in a manner capable of securingthe drive at precise increments of rotational advance.

Another object related to the last is to provide such a latch that is capable of holding a precise position and also capable of automatically adjusting its engagement to compensate for an anticipated sag in the rotary drive or driven member such as otherwise would result in a misalignment of the latch members and a consequent error in the precision of the secured position.

A further object is to provide such a latch with a switching mechanism related to latch operation in a manner capable of electrically relaying latch position information.

Another object is to provide a hydraulicallynctuated latch adapted to normally engage a rotary drive in the absence of hydraulic actuation.

Other objects are to provide a simple, reliable, multiple position latch capable of precise operation.

In a manner will become clear the objects are achieved by coupling a sprocket wheel or the like to the shaft of the drive to be latched and, further by utilizing a driven piston to operate a toggle arrangement which carries a pair of latching arms adapted to engage the sprocket wheel. In the preferred form, the toggle also mounts means responsive to latch actuation for remotely controlling the piston drive. Other features of the invention will become more apparent in the detailed description that is to follow.

The invention is illustrated in the accompanying drawings of which:

FIG. 1 is a perspective illustration of one form of the present latch mechanism;

FIG. 2 is a side elevation of another embodiment of the invention; and

PEG. 3 is an enlarged fragmentary View of a portion of the PEG. 2 latch illustrating in a schematic manner its sag-compensating, selfadjustment feature.

Referring to 1, it may be noted that the rotating objector member tobe latched is represented by a drive shaft 1' which may be considered as operatively coupled to a hydraulic motor (not shown), this motor driving through shaft 1 into suitable gear reduction unit, the out- 3,l24,l2 Patented Mar. 10, 1964 2 put of which usually is meshed with a driver gear to impart its motion to a turret or other physical object. In the missile launcher environment, for example, the hydraulic motor is provided by a B-end motor carriedby a rotating turret which also carries a pair of launcher arms onto which the missiles are to be loaded.

Considering the presently-involved missile launcher system in greater detail, its major components, in addition to its rotatable turret and launcher arms,- includes a cylindrical magazine having concentric rings of missilerewiving cells, and a chain hoist mechanism carried by the launcher arms and adapted to be r-unnably-extended through suitable rails into the magazine cells to engage and hoist the missiles into filing position on the arms. In a manner that can be visualized, the launcher arm, as well as the magazine cells, are provided with identical rail sections which, of course, must be mated or aligned to provide a continuous track for the chain hoist and for the missile shoes. In this regard, the missiles carry conventional shoes or lugs which ride in the rail sections to provide missile support both in the magazine and on the rails, and the hoist accomplishes its lift by engaging the missile shoes. Both the hoist and the shoes then travel in the mack provided by the mated mail sections.

To form the continuous track it is necessary to rotate the launcher arms into a position directly over the particular missiles to be fired and, further, since the magazine cells support the missiles in a vertical position, the arms then must be elevated into a vertical position to cause their rails to vertically align with the magazine rails.

For this purpose, the turret is rotatable about the vertical axis of the magazine and its arms are rotatable on this vertical axis directly over one or the other of the rings of magazine cells. The arms may be laterally shifted in a telescopic manner to accommodate the spacing of the concentric rings. Also, the launcher arms are rotatably elevatable about a horizontal axis so as to permit their elevation into vertical alignment with the magazine rails. It is interesting to note that these rotational movements of the arms also are used to initially aim the missiles to be fired since the movements provide the necessary target training and elevation angles.

The latch of the present invention is incorporated in this missile launcher to secure both the train and elevation movements of the arms when the arms are rotated or elevated into a missle loading alignment with the magazine cells. More specifically, one of the latches is used to secure the elevation movement of the arms, While the ther secures the arms in a fixed position over any diametrically-opposed pair of magazine cells. The elevation latches, for reasons to be considered, need provide only two latch positions. However, the train latch, at least in the actual launcher arrangement, must be arranged to secure the arms at every 2 /2 of rotational advance. The reason for this latter requirement is because the magazine has the previously-mentioned concentric ring arrangement including an outer ring of 24 cells and an inner ring of 18. Consequently, if a launcher arm is to-pick up an outer ring missile, it must rotate at least 15 from one missile cell to another. Similiarly, if it is to pick up an inner ring missile, it must rotate at least 20. However, the situation is not quite this simple since the outer and inner rings are radially staggered 2 /2 A one from'the other, the result being that the arms must be capable of being stopped and latched in 2 /2 rotational increments of the arms. Also, because of the need for absolute alignment of the launcher arm rails with the missle rails, the indexing of the arms must be very precise.

The manner in which this latching operation is accomplished provides a principal feature of the present invention. Generally, it is achieved by mounting a sprocket wheel 6 on shaft 1 and by utilizing a piston-driven toggle arrangement to open and close the jaws of the latch about the sprocket wheel. Before continuing with structural details, it should be noted that the embodiments of FEGS. 1 and 2 are precisely the same except for the shape of sprocket wheels 6. Thus, in the FIG. 1 embodiment, a sprocket wheel having 12 teeth or detents 7 is employed, While in the FIG. 2 embodiment, the sprocket wheel has only two teeth or detents. Obviously, the two latches are adapted for different purposes and, again relating the mechanism to the missle launcher environment, the 12- detent sprocket wheel is used to latch the train movement of the turret, while the 2-detent sprocket wheel is used to latch the elevation movement. The latching of the elevation movement requires only two positions, these being its stowed position and a fully elevated position. However, as previously described, the train movement requires a large number of securable positions, so that the sprocket wheel itself is provided with an appropriate number of latch positions. However, the actual number of latch positions on the sprocket wheel is a function of the gear reduction ratio between the input and output of the rotary drive. In the particular launcher arrangement, a 60 to 1 gear reduction may be used between rotary drive shaft 1 and the output and, such being the case, it is necessary to have a 12-detent sprocket wheel.

Continuing with reference to FIGS. 1 and 3, features common to both latch mechanisms include a supporting hydraulic cylinder mount bracket 8 which may be bolted or otherwise secured to approximate stationary structure such as a surface of the turret or the gear reduction housing which itself is carried by the turret. The bracket is formed at its upper end with a pair of side walls 9 and 11 and a rear wall 12. At its lower end, the bracket is provided with a base portion having laterally extended flanges 13 and 14 that support the toggle mechanism to be described.

Also supported by bracket 3 is a hydraulic cylinder 16 which mounts a piston 17 having an upper rod portion 13 and a lower rod portion 19, both of which project out wardly through suitable bushings and sealing members provided at both ends of the cylinder. An upper cylinder head 21 is used to mount a sleeve member 2-2 that carries a spring 23 between its upper end wall and a spring retainer flange 24 formed on rod portion 13, which, as shown, projects into the sleeve member. Spring 23 exerts its resilient pressure on the upper end of the piston to normally urge the piston in a downwardly direction (FIG. 2).

To drive the piston, hydraulic fluid lines 27 and 23 lead into the upper and lower ends of cylinder in and it will be apparent that, when fluid is supplied through line 28, the piston is moved upwardly against the force of spring 23.

The toggle mechanism which carries the latching members is secured to lower piston rod extension l) by a clevis 29, this clevis having a pin 31 in which a pair of laterallyextending toggle links 32 and 33 are hung in a conventional manner. Also, the outer ends of each toggle links 32 and 33 are pivotally coupled to a pair of rocket arms 34 and 36, these arms each being provided at their upper ends with a similar clevis 37 carrying pins 33 by means of which the couplings are made. The lower ends of rocker arms 34 and 36 carry the latching members of the toggle arrangements, these latching members being in the form of rollers 39 and il supported on pins 42 and 43 carried by the rocker arms. As would be expected, the rollers are sized to fit into teeth or detents 7 of the sprocket wheels and the arrangement is such that the latch rollers are carried by the toggle on diametrically opposite sides of the sprocket wheel to engage the wheel at a 186 circumferential spacing and hold the wheels in fixed and latched positions.

To provide the desired pivotal motion to move the rocker arms into and out of latch engaging position, each of the rocker arms is pivotally secured by pins 44 and 46 to flanges 13 and 14 of the cylinder mount bracket in the manner illustrated. Consequently, vertically reciprocal movement of the piston causes each of the rocket arms to pivotally rotate about the axis of their inter-connection with pins 4-4 and as of the cylinder mount bracket. More specifically, an upward movement of rod 19 from its illustrated position causes links 32 and 33 to swing their pins 38 inwardly about pins 44 and 46. Latch rollers 39 and 41, in turn, swing outwardly to release their latching engagement with the sprocket wheel detents. Obviously, a downward return stroke moves the rollers back into latching engagement.

Another feature of the invention is the provision of a switch mechanism adapted to provide an indication of a latched or unlatched condition, or, if desired, to provide remote control for the shutting off or initiating the power producing the rotary drive of drive shaft 1.

The particular switch mechanism employed is closely coordinated with the movements of rocker arms 34 and 36 by being mounted on a bracket 47 which, in turn, is bolted to flange 14 of cylinder mount bracket 8. The switches themselves are conventional plunger type switches 43 and 49 provided with plunger arms 51 and 52 which project inwardly toward contact plates 53 and 54- carried by rocker arm 36. Consequently, the rocking movement of the arm depresses the upper or lower plunger depending upon whether the latch is opened or closed. In other words, when the latch is closed, as shown in FIG. 2, upper plunger 52 engages the upper contact plate 54 and is depressed in a manner which will be apparent. When the latch is released, the rocking movement depresses plunger 51.

The operation of the mechanism should be relatively clear from the foregoing description. Considering the example of the missile launcher apparatus which had been briefly outlined, if it is desired to latch the train movement of the rotary turret, a latch having a sprocket wheel similar to the FIG. 1 sprocket wheel may be employed. As already noted this latch has 12 teeth or detents which, because of the particular gear reduction ratio employed,

ermits the train movement to be latched at each of the missile cell positions defined by the inner and outer cell arrangement of the magazine.

In the assumed situation, the Bend motor producing the turret rotational drive is permitted to impart its drive to the input shaft and, simultaneously, hydraulic pressure is supplied to hydraulic cylinder 16 of the latch mechanism through pressure line 28 to move the piston upwardly and cause the rocker arms to rock outwardly into a latch release position. In the actual mechanism, the rotational advance of the turret is closely controlled by a precise indexing mechanism which permits a reasonably rapid advance until the final approach of the turret to its selected disposition over the missile to be loaded. Also, suitable valves and relays are provided so that, at precisely the moment the turret brings its launcher arms to the desired position, pressure is reversed in tank and pressure lines 27 and 28 to cause the piston to move downwardly to engage latch rollers with the teeth of the sprocket wheel. At the same time, the rocking movement strikes upper plunger 52 of the switch mechanism. As also may be noted, sprocket wheels 6 of both embodiments are couplcd to input shaft 1 by a flexible coupling which is a conventional disk-type coupling. A further feature which has not been mentioned but which is apparent in the arrangement is the fact that any loss of hydraulic pressure results in piston 17 being driven downwardly by spring 23 so as to latch the rotary drive and the turret in the fixed position.

FIG. 3 illustrates still a further important functional advantage of this type of multiple position latch. Thus, in some applications, including the missile launcher one, it can be expected that there will be some sag in the power drive which, because of the precision required, should be compensated in some manner. The present sprocket-type latch provides this compensation by centering itself in the bottom of each sprocket-wheel detent as the latch rollers close into latching engagement. If, for example, a sag is present such as would cause rollers 39 and 41 to strike in the dotted line position shown in FIG. 3, the rollers produce a sprocket movement necessary to reposition the detents precisely so that the rollers actually engage in their full line position. Such a repositioning compensates for the sag which in the missile use may be as high as 8.

In general, the latch mechanism described provides an unusually simple and thoroughly reliable and sturdy mechanism for precisely latching a rotary drive at predetermined increments of rotational advance, these increments being, in a sense built into the mechanism by providing the sprocket wheel with a proper number and spacing of teeth or detents.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. Apparatus for latching a rotary member in a plurality of rotated positions comprising a wheel, means coupling the Wheel for rotation with said rotary member and provided peripherally with a plurality of detents, a support bracket formed with a pair of flange members projecting outwardly in opposite directions, a reciprocably fluid pressure driven member carried by said support bracket, a pair of toggle links pivotally coupled on a common axis to said driven member and extending outwardly from said common axis generally parallel to said flanges, a rocker arm pivotally coupled at one end to the outer end of each of said toggle links, latch means carried by the other end of rocker arms, and means pivotally coupling the outer end of each of said flanges medially to each of said rocker arms, said links, arms and flanges forming a toggle arrangement supporting said latch means in diametrically-opposed positions on either side of said wheel, said toggle swingably moving said latch means into and out of detent-engaging positions.

2. The apparatus of claim 1 further including a pair of switches carried by one of said flange members in position for being operatively engaged upon said pivotal opening and closing movements of their proximate latch arm.

3. The apparatus of claim 1 wherein said detents are formed as teeth for receiving said latch means, and said latch means include a roller adapted for engaging the inner surface of said indentations, said adjacent teeth being spaced one from the other a predetermined distance permitting initial engagement of said rollers on said teeth portions and subsequent repositioning of the wheel by the rollers to compensate for axial misalignment of said gear input and output.

4. The apparatus of claim 1 wherein said driven means includes a cylinder, a piston mounted in the cylinder, mechanical means resiliently urging said piston into latchengaging position, and fluid pressure means for reciprocally moving said piston into latch-dis-engaging position.

References Cited in the file of this patent UNITED STATES PATENTS 2,315,597 Conrad Apr. 6, 1943 FOREIGN PATENTS 176,536 Switzerland July 1, 1935 575,793 Great Britain Mar. 5, 1946

Claims (1)

1. APPARATUS FOR LATCHING A ROTARY MEMBER IN A PLURALITY OF ROTATED POSITIONS COMPRISING A WHEEL, MEANS COUPLING THE WHEEL FOR ROTATION WITH SAID ROTARY MEMBER AND PROVIDED PERIPHERALLY WITH A PLURALITY OF DETENTS, A SUPPORT BRACKET FORMED WITH A PAIR OF FLANGE MEMBERS PROJECTING OUTWARDLY IN OPPOSITE DIRECTIONS, A RECIPROCABLY FLUID PRESSURE DRIVEN MEMBER CARRIED BY SAID SUPPORT BRACKET, A PAIR OF TOGGLE LINKS PIVOTALLY COUPLED ON A COMMON AXIS TO SAID DRIVEN MEMBER AND EXTENDING OUTWARDLY FROM SAID COMMON AXIS GENERALLY PARALLEL TO SAID FLANGES, A ROCKER ARM PIVOTALLY COUPLED AT ONE END TO THE OUTER END OF EACH OF SAID TOGGLE LINKS, LATCH MEANS CARRIED BY THE OTHER END OF ROCKER ARMS, AND MEANS PIVOTALLY COUPLING THE OUTER END OF EACH OF SAID FLANGES MEDIALLY TO EACH OF SAID ROCKER ARMS, SAID LINKS, ARMS AND FLANGES FORMING A TOGGLE ARRANGEMENT SUPPORTING SAID LATCH MEANS IN DIAMETRICALLY-OPPOSED POSITIONS ON EITHER SIDE OF SAID WHEEL, SAID TOGGLE SWINGABLY MOVING SAID LATCH MEANS INTO AND OUT OF DETENT-ENGAGING POSITIONS.

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