Abstract:
A mounting mechanism is provided for aligning and securing an optical instrument to a platform. The mechanism includes a housing, a trunnion and a base-plate. The housing receives the optical instrument along a longitudinal axis. The housing includes an attach support for the optical instrument, and an interface having vertically-facing cylindrical-fastener orifices. The trunnion supports the housing at the interface. The trunnion has pluralities of vertical slots and horizontal slots. Each vertical slot overlaps a corresponding vertical orifice. The vertical slots provide elevation displacement to vertically translate and pitch the housing. The horizontal slots provide lateral displacement to horizontally translate and yaw the housing. The base-plate supports the trunnion and is mountable onto the platform. The base-plate has a plurality of horizontally-facing cylindrical-fastener orifices. Each horizontal slot on the trunnion overlaps a corresponding horizontal orifice on the base-plate. Each orifice of the vertically- and horizontally-facing orifices receives a cylindrical-fastener that passes through a counterpart slot of the vertical and horizontal slots. Each cylindrical fastener for each orifice corresponds to a helical screw.

Description:
STATEMENT OF GOVERNMENT INTEREST 
     The invention described was made in the performance of official duties by one or more employees of the Department of the Navy, and thus, the invention herein may be manufactured, used or licensed by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor. 
    
    
     BACKGROUND 
     The invention relates generally to devices for securely mounting and aligning precision optical components. In particular, such mounts are intended to provide precise alignment in multiple axes for instruments, such as a fiber laser collimator. 
     Optical devices employ mounting mechanisms to provide alignment relative to a platform to be oriented with respect to line-of-sight. Such devices are designed to adjust for pitch, yaw and roll pivoting, as well as lateral and vertical translation. 
     Precision optical systems require mounting and adjusting of multiple components along the optical path to accomplish a given task. Four (4) adjustments commonly required include tip-tilt and translation in two (2) axes at either end. These adjustments are typically performed by two separate mounts and actuators, one for tip-tilt and one for both translations. 
     SUMMARY 
     Conventional optical mounts yield disadvantages addressed by various exemplary embodiments of the present invention. In particular, various exemplary embodiments provide a mount with overlapping orifices on either the base-plate or the housing for an optical element and slots on the intervening cradle to receive fasteners that enable horizontal and vertical adjustment. 
     Various exemplary embodiments provide a mounting mechanism for aligning and securing an optical instrument to a platform. The mechanism includes a housing, a trunnion (or cradle) and a base-plate. The housing receives the optical instrument along a longitudinal axis. The housing includes an attach support for the optical instrument, and an interface having vertically-facing cylindrical-fastener orifices. 
     The trunnion supports the housing at the interface. The trunnion has pluralities of vertical slots and horizontal slots. Each vertical slot overlaps a corresponding vertical orifice. The vertical slots provide elevation displacement to vertically translate the housing. The horizontal slots provide lateral displacement to horizontally translate the housing. 
     The base-plate supports the trunnion and is mountable onto the platform. The base-plate has a plurality of horizontally-facing cylindrical-fastener orifices. Each horizontal slot on the trunnion overlaps a corresponding horizontal orifice on the base-plate. Each orifice of the vertically- and horizontally-facing orifices receives a cylindrical-fastener that passes through a counterpart slot of the vertical and horizontal slots. Each cylindrical fastener for each orifice corresponds to a helical screw 
     The housing and trunnion can include parallel and overlapping ledges to enable jack-screws to pass therethrough to inhibit wobble. In various exemplary embodiments, the housing is unitary. In alternate embodiments, the housing comprises several interfacing components. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and various other features and aspects of various exemplary embodiments will be readily understood with reference to, the following detailed description taken in conjunction with the accompanying drawings, in which like or similar numbers are used throughout, and in which: 
         FIG. 1  is a first perspective assembly view of an optical mount for a first embodiment; 
         FIG. 2  is a second perspective assembly view of the optical mount; 
         FIG. 3  is a perspective cross-section view of the optical mount; 
         FIG. 4  is a third perspective assembly view of the optical mount; 
         FIG. 5  is a fourth perspective assembly view of the optical mount; 
         FIG. 6  is a firth perspective assembly view of the optical mount; 
         FIG. 7  is a first perspective exploded view of the optical mount; 
         FIG. 8  is a second perspective exploded view of the optical mount; 
         FIG. 9  is a third perspective view exploded of the optical mount; 
         FIG. 10  is a fourth perspective exploded view of the optical mount; 
         FIG. 11A through 11C  are perspective detail views of the optical mount; 
         FIG. 12  is a perspective assembly view of an optical mount for a second embodiment; 
         FIG. 13  is a first perspective view of a mount subassembly; 
         FIG. 14  is a second perspective view of the mount subassembly; and 
         FIG. 15  is a third perspective view of the mount subassembly. 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description of exemplary embodiments of the invention, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific exemplary embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments may be utilized, and logical, mechanical, and other changes may be made without departing from the spirit or scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims. 
     Conventional actuators can be unwieldably large and do not usually permit the researcher to lock them securely once the desired adjustment has been made, being laboratory devices. These devices occupy a much greater volume (roughly double) for the same number of axes than provided by various exemplary embodiments. Additionally, conventional methods typically incorporate active drive in only a single direction of an axis, while relying on springs to maintain preload and restrict motion in the opposite direction. This results in a device having stability only in the confines of a laboratory, and therefore not being sufficiently rugged to be suitable for field or military use. 
     Various exemplary embodiments consist of three major components: 
     First, a main housing that mounts the optical component, such as a fiber laser collimator shown in the drawings. The housing contains a spherical plastic bearing at one end, and multiple setscrews at the other. By driving opposing screws in opposite directions, the optical device rotates about the spherical bearing, providing tip-tilt motion. 
     Second, a trunnion that supports the main housing. This mates with the main housing and base-plate and provides vertical translation of the main housing and optical component relative to the trunnion. It incorporates multiple very fine pitch jack-screws (80-threads/inch) and lock-screws which drive and subsequently lock vertical motion between the trunnion and main housing. 
     Third, a base-plate that supports the trunnion. This provides horizontal translation of the trunnion, main housing, and optical device relative to the baseplate. It incorporates one very fine pitch jack screw (80 threads/inch) and lock screws which drive and lock horizontal motion between the base-plate and trunnion. 
     The incorporation of multiple axes of adjustment in a small volume represents a particular advantage of the exemplary embodiments. Conventional means usually require at least two separate devices to accomplish the same task. In particular, conventional devices separately employ a first mechanical stage to perform tip-tilt adjustment and a second mechanical stage to perform horizontal translation. Each of the two separate devices usually require approximately the volume used in these embodiments to perform both adjustments. Another important advantage and novel capability of these embodiments involves securely locking the device in position after completing the required adjustments. 
       FIG. 1  shows a first perspective assembly view  100  of a compact rugged multi-axis optical mount in a first embodiment to reveal the port side. The mount assembly holds an optical element  110 , such as a fiber laser collimator. A main housing  120  contains the optical element  110  and includes of a cylindrical tube that attaches to an interface bracket  125 , shown as an integral unit. A spherical joint tightening ring  130  maintains the optical element  110  at its fore end by clamping a bearing joint described further. A trunnion  140  attaches to the interface  125 . A base-plate  150  attaches to the trunnion  140 . 
     The housing  120  adjustably clamps the optical element  110  with four (4) tip-tilt opposing adjustment lock-screws  160  arranged in cruciform pattern at the aft end. In alternative configurations, the housing  120  can be adjustable or replaced with a cylindrical container to receive another device with a different geometry than the optical element  110 . The interface  125  and trunnion  140  connect together by three (3) vertical axis jack-screws  165 . The trunnion  140  and the base-plate  150  attach at their corresponding corners with four (4) horizontal axis lock-screws  170  mounted vertically. 
     Four (4) vertical axis lock-screws  175  enable adjustment of tilt alignment between the trunnion  140  and the interface  125  of the housing  120  the four vertical axis lock-screws  175 . Two (2) mount screws  180  attach the base-plate  150  to the stationary platform (not shown). The pair of mount screws  180  connects at fore and aft ends of the base-plate  150  to the platform. 
     A compass rose  190  displays relative orientation axes of the assembly along the longitudinal axis (fore and aft), horizontal lateral axis (port and starboard) and vertical lateral axis (top and bottom). These orthogonal axes further indicate respective roll, pitch and yaw rotation. The optical mount using the lock-screws  170  and  175  can adjustably translate the optical element  110  in two of these: lateral and vertical directions. The lock-screws  160  for this first described embodiment can also incrementally pivot the optical element  110  around these respective axes for limited pitch and yaw adjustment. 
       FIG. 2  shows a second perspective assembly view  200  of the first embodiment from the bottom. The optical element  110  includes a receiving lens  210  at the fore end. A bottom bracket  220  protrudes from the trunnion  140 . A horizontal axis adjustment bolt  230  connects the base-plate  150  to that bracket  220 , which extends into a through-vertical cavity  240  of the base-plate  150 . The interface  125  includes a housing port ledge  250 . The trunnion  140  includes a trunnion port ledge  260 . Two (2) of the three (3) jackscrews  165  pass through co-axial orifices of the port ledges  250 ,  260 . 
       FIG. 3  shows a perspective cutaway view  300  of the compact rugged multi-axis optical mount. At the assembly fore end, a spherical bearing joint  310  is radially disposed between the receiving lens  210  and the ring  130  (by clamping the joint  310 ) to provide cantilever support for the optical element  110 . The joint  310  extends a tang that radially disposes between the optical element  110  and the housing  120  to secure the optical element  110  at the fore end of the housing  120 . The radially inward lock-screws  160  provide counter-support opposite for the optical element  110  at the aft end of the housing  120 . 
       FIG. 4  shows a third perspective assembly view  400  of the star-board side. Although the housing  120  and the optical element  110  shown in the view  400  are longer and thinner than their counterparts in view  100 , these constitute analogous components throughout. The interface  125  includes a housing starboard ledge  410 . The trunnion  140  includes a trunnion starboard ledge  420 . One (1) of the three (3) jackscrews  165  pass through co-axial orifices of the starboard ledges  410 ,  420 .  FIG. 5  shows a fourth perspective assembly view  500  of the starboard side.  FIG. 6  shows a fifth perspective assembly view  600  from the bottom side. 
       FIG. 7  shows a first perspective exploded view  700  of components of the compact rugged multi-axis optical mount. The housing  120  includes a forward opening  710  to receive the optical element  110 . The trunnion  140  includes vertical plane slot-orifices  720  to receive the lock-screws  175 . The trunnion  140  also includes horizontal screw orifices  730  enable the mount screws  180  to pass through to the base-plate  150 . 
       FIGS. 8 and 9  respectively show second and third perspective exploded views  800  and  900 . The housing  120  includes an aft opening  910  through which the optical element  110  passes. The trunnion  140  includes horizontal plane slot-orifices  920  to receive the lock-screws  170 .  FIG. 10  shows a fourth perspective exploded view  1000  illustrating the bottom of the components. 
       FIGS. 11A ,  11 B and  11 C show perspective detail views  1100  illustrating the particular components related to the bolts  165  and  230 .  FIG. 11A  shows a first detail view  1110  from the fourth perspective view  500 .  FIG. 11B  shows a second detail view  1120  from the third perspective view  400 .  FIG. 11C  shows a third detail view  1130  from the fifth perspective view  600 . The slot-orifices  720  on the trunnion  140  permit vertical translation of the interface  125  and/or pivotable adjustment in pitch rotation. The slot-orifices  920  on the trunnion  140  permit its lateral translation along the base-plate  150 . The lock-screws  170  secure the trunnion  140  vertically to the base-plate  150 ; the adjustment bolt  230  secures the trunnion  140  laterally to the base-plate  150 . The mount screws  180  secure the base-plate  150  to the stationary platform. 
     Pre-load tension applies to bolts  165  and  230  by a spring  1140  held in position by an e-clip  1150 . The spring  1140  typically represents a washer with radially concave curvature. The e-clip  1150  constitutes an open circular flat fastener. To impose the pre-load, the spring  1140  and e-clip  1150  are disposed, for example, between the head of the bolt  165  and the ledges  250 ,  410 . The combined triplet of bolts  165  anchors the interface  125  of the housing  120  (without rocking) by the ledges  250  and  410  to their counterpart ledges  260  and  420  of the trunnion  140 . 
       FIG. 12  shows a perspective assembly view  1200  of a second embodiment of a compact rugged multi-axis optical mount in a second embodiment to reveal the starboard side. A telescope  1210 , representing the optical element, can be cantilever-supported at its aft end by a cylindrical housing  1220 , which connects via a cylindrical bracket  1225  to a camera block  1230 . An upper support  1240  supports the housing  1220  and block  1230 . A lower support  1250  supports the upper support  1240 . A cradle  1260  connects the lower support  1250  to a base-mount  1270  for attachment to a platform. 
       FIG. 13  shows a first perspective assembly view  1300  of the supports  1240 ,  1250 , cradle  1260 , and base-mount  1270 . The upper support  1240  includes a fore tongue  1310  and an aft ledge  1315 . The tongue  1310  and ledge  1315  connect together by an interface that includes a tang  1320  and a cavity  1325 . A mount extension  1330  secures the tongue  1310  to the lower support  1250 , which includes an aft groove  1340  to contain the ledge  1315  and a forward plate  1345  on which the extension  1330  attaches. 
     The cradle  1260  includes lateral walls  1350 , a fore ledge  1355 , and an aft ledge  1360 . The base-mount  1270  includes a front pad  1365 , a rear pad  1370 , and lateral brackets  1375  adjacent the walls  1350  and onto which attach pivotable feet  1380  that flank the walls  1350 . Screws  1385  secure the feet  1380  to their respective brackets  1375 , as well as the forward plate  1345  to the fore ledge  1360 . Two of the screws  1385  flank the extension  1330 , and a third screw  1385  inserts through the orifice  1325 . 
       FIG. 14  shows a second perspective assembly view  1400  of the supports  1240 ,  1250 , the cradle  1260  and the base-mount  1270  from the upper side. The feet  1380  include holes  1410  for mounting the base-mount  1270  to the platform. The front and rear pads  1365 ,  1370  also include horizontal-plane orifices  1420  for attaching the base-mount  1270  to the platform. The fore and aft ledges  1355 ,  1360  have horizontal slots  1430  that superimpose over their counterpart orifices  1420  to adjustably secure the cradle  1260  to the base-mount  1270 . The slots  1430  enable adjustment of the cradle  1260  relative to the base-mount  1270  in lateral translation. 
     The groove  1340  includes horizontal-plane holes  1440  to restrict in pitch the aft portion of the lower support  1250  to the tang  1320  of the upper support  1240 . The groove  1340  includes vertical-plane holes  1450  to secure in yaw the aft portion of the lower support  1260  to the tang  1320  of the upper support  1250 . The ledge  1315  of the upper support  1240  includes horizontal-plane holes  1460  to secure the camera block  1230  thereto. The extension  1330  includes a horizontal-plane hole  1470  to connect the upper support  1240  to the lower support  1250 . The holes  1450  enable yaw adjustment of the upper support  1250  in relation to the lower support  1260  from the extension  1330  as anchor. The mount assembly for this second described embodiment can incrementally pivot the optical element telescope  1210  around the longitudinal axis for limited roll adjustment, with translation in lateral and vertical directions. 
       FIG. 15  shows a third perspective assembly view  1500  of the supports  1240 ,  1250 , the cradle  1260  and the base-mount  1270  from the lower side. The walls  1350  include vertical slots  1510  adjacent the ledges  1255 ,  1260 . The lower support  1250  includes counterpart orifices  1520  to receive corresponding screws to secure the lower support  1250  to the cradle  1260  adjustment available in vertical translation along the slots  1510 . The brackets  1370  include holes  1530  to secure the feet  1360  to the walls  1350 . The base-mount  1270  includes a longitudinal beam  1540  extending front to rear to connect together the pads  1365 ,  1370  and the feet  1360  together. 
     By these exemplary embodiments, the optical element can be securely mounted to a stationary platform, while enabling adjustment in translation and/or rotation in all Cartesian coordinates. These adjustments can be performed by fasteners, such as screws and/or bolts that pass through a pair of overlapping orifices, the outer orifice of which includes dimensions that permit modest movement prior to locking engagement. 
     While certain features of the embodiments of the invention have been illustrated as described herein, many modifications, substitutions, changes and equivalents will now occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the embodiments.