Patent Publication Number: US-2012032048-A1

Title: Adjustable and lockable bushing assembly and component mounting assembly using the same

Description:
TECHNICAL FIELD 
     The present invention generally relates to bushings used as part of component mounting hardware, and more particularly relates to an adjustable and lockable bushing assembly. 
     BACKGROUND 
     Many mechanical components and mounting structures, such as those used in the aerospace industry, may be precision manufactured. Even so, these mechanical components and mounting structures still have certain manufacturing and assembly tolerances. These tolerances can impact the overall operational space envelope of the mechanical components. For example, in the context of an actuator that is configured to translate between extended and retracted positions, the manufacturing and assembly tolerances associated with the actuator and associated mounting structures and mounting hardware can impact its overall operational length. 
     While presently known devices are available to compensate for manufacturing and assembly tolerances, these solutions can, in many instances, rely on relatively complex components. Accordingly, it is desirable to provide relatively simple, non-complex, and inexpensive mounting hardware that provides adjustable component mounting capability to compensate for manufacturing and assembly tolerances. The present invention addresses at least this need. 
     BRIEF SUMMARY 
     In one exemplary embodiment, an adjustable and lockable bushing assembly includes a locking plate and a bushing. The locking plate has a first side, a second side, and a bushing engagement opening that extends between the first and second sides and is defined by a plurality of first serrations. A boss extends axially from the locking plate first side and is configured to engage a stationary component. The bushing engages the locking plate and includes a concentric section, an eccentric section, a lock interface section, and an opening. The opening has a fixed diameter and extends along a longitudinal axis through the concentric section, the eccentric section, and the lock interface section. The concentric section includes a first end, a second end, and a first outer surface that has a first circumference that is concentric with the longitudinal axis. The eccentric section extends from the concentric section first end and has a second outer surface that has a second circumference that is eccentric with the longitudinal axis. The lock interface section extends from the concentric section second end and includes an outer surface defined by a plurality of second serrations. Each of the second serrations engages one of the first serrations that define the locking plate opening. 
     In another exemplary embodiment, a component mounting assembly includes a clevis, a component, a mount lug, and an adjustable and lockable bushing assembly. The clevis has parallel first and second arms. The first arm has a first opening extending there-through and a lock opening formed therein, and the second arm has a second opening extending there-through that is concentric with the first opening. The component has a mount portion disposed between the first and second arms and has a mount opening extending there-through. The mount lug extends through the first opening, the second opening, and the mount opening. The adjustable and lockable bushing assembly includes a locking plate and a bushing. The locking plate has a first side, a second side, and a bushing engagement opening that extends between the first and second sides and is defined by a plurality of first serrations. A boss extends axially from the locking plate first side and is disposed within the lock opening. The bushing extends through at least the first opening and the mount opening, and surrounds at least a portion of the mount lug. The bushing engages the locking plate and includes a concentric section, an eccentric section, a lock interface section, and a mount lug opening. The mount lug extends through the mount lug opening, which has a fixed diameter and extends along a longitudinal axis through the concentric section, the eccentric section, and the lock interface section. The concentric section includes a first end, a second end, and a first outer surface that has a first circumference that is concentric with the longitudinal axis. The eccentric section extends from the concentric section first end and has a second outer surface that has a second circumference that is eccentric with the longitudinal axis. The lock interface section extends from the concentric section second end and includes an outer surface defined by a plurality of second serrations. Each of the second serrations engages one of the first serrations that define the locking plate opening. 
     Furthermore, other desirable features and characteristics of the adjustable and lockable bushing assembly will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and wherein: 
         FIG. 1  depicts an exemplary component mounting configuration; 
         FIG. 2  depicts a close-up cross section view of that portion of the component mounting configuration that is encircled in  FIG. 1 ; 
         FIG. 3  depicts an embodiment of an adjustable and lockable bushing assembly in its assembled state; 
         FIG. 4  depicts the individual components of the adjustable and lockable bushing assembly of  FIG. 3 ; 
         FIG. 5  depicts an alternative embodiment of a bushing that may be used to implement the adjustable and lockable bushing assembly depicted in  FIGS. 3 and 4 ; 
         FIGS. 6-8  depict a close-up cross section view similar to that depicted in  FIG. 2 , with the adjustable and lockable bushing assembly in different rotational positions; and 
         FIG. 9  depicts the different actuator lengths that may result from different rotational positions of the adjustable and lockable bushing assembly. 
     
    
    
     DETAILED DESCRIPTION 
     The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. As used herein, the word “exemplary” means “serving as an example, instance, or illustration.” Thus, any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments. All of the embodiments described herein are exemplary embodiments provided to enable persons skilled in the art to make or use the invention and not to limit the scope of the invention which is defined by the claims. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary, or the following detailed description. In this regard, although exemplary embodiments are described in the context of mounting an actuator, it will be appreciated that the invention may be used to mount any one of numerous devices and components. 
     Referring now to  FIG. 1 , an exemplary component mounting configuration is depicted. The depicted component is an actuator  102  that is mounted on a support structure via a clevis  104  and adjustable component mounting hardware  106 . It will be appreciated that the depicted actuator  102  is merely exemplary of any one of numerous components that may be mounted using the adjustable component mounting hardware  106  described herein. 
     As shown more clearly in  FIG. 2 , the actuator  102  includes a mount portion  202 , through which a mount opening  204  extends. The clevis  104  includes a first arm  206  and a second arm  208 , which are disposed parallel to each other. A first opening  212  extends through the first arm  206 , and a second opening  214  extends through the second arm  208 . The actuator mount portion  202  is disposed between the first and second arms  206 ,  208 , and at least a portion of the adjustable mounting hardware  106  extends through the first opening  212 , the second opening  214 , and the mount opening  204 . 
     The adjustable mounting hardware  106 , at least in the depicted embodiment, includes at least a mount lug  216 , fastening hardware  218 , and an adjustable and lockable bushing assembly  220 . The mount lug  216  extends through the first opening  212 , the second opening  214 , and the mount opening  204 . The depicted mount lug  216  has a first end  223 , on which non-illustrated threads are formed, and a second end  224 . The fastening hardware  218 , which in the depicted embodiment is a threaded nut, is threaded onto the first end of the mount lug  216 . As  FIG. 2  also depicts, the mount lug  216  extends through the adjustable and lockable bushing assembly  220 , an embodiment of which will now be described. 
     With reference now to  FIGS. 3 and 4 , the adjustable bushing assembly  220  includes a locking plate  302  and a bushing  304 . The locking plate  302  includes a first side  306 , a second side  308 , and a bushing engagement opening  312 . The bushing engagement opening  312  extends between the first and second sides  306 ,  308 , and is defined by a plurality of first serrations  314 . The configuration and number of first serrations  314  may vary, but in the depicted embodiment the first serrations  314  are configured as twelve evenly spaced, and generally triangle-shaped protrusions that extend radially inwardly toward the center of the bushing engagement opening  312 . As will be described momentarily, the first serrations  314  engage like-configured serrations on the bushing  304  to lock the bushing  304  in place. 
     As  FIGS. 3 and 4  also depict, a boss  316  extends axially from the locking plate first side  306 . The boss  316  is configured to engage a stationary component, to thereby prevent its rotation, and concomitantly the rotation of the bushing  304 . In the context of the mounting arrangement depicted in  FIG. 1 , and as depicted therein, the boss  316  is configured to be disposed within a lock opening  222  that is formed in the first arm  206  of the clevis  104 . 
     Returning once again to  FIGS. 3 and 4 , the bushing  304  includes a concentric section  318 , an eccentric section  322 , a lock interface section  324 , and an opening  326 . The opening  326  has a fixed diameter and extends, along a first longitudinal axis  402 , through the concentric section  318 , the eccentric section  322 , and the lock interface section  324 . The concentric section  318  includes a first end  327 , a second end  328 , and a first outer surface  332 . The first outer surface  332  has a first circumference that is concentric with the first longitudinal axis  402  and, when used in the mounting arrangement depicted in  FIG. 1 , is concentric with the mount lug  216  and the first opening  212  in the first arm  206 . 
     The eccentric section  322  extends from the concentric section first end  327 , and has a second outer surface  334 . The second outer surface  334  has a second circumference that is eccentric with the first longitudinal axis  402  and, when used in the mounting arrangement depicted in  FIG. 1 , is eccentric with the mount lug  216  and the mount opening  204  in the mount portion  202  of the actuator  102 . In particular, and as shown more clearly in  FIG. 4 , the second outer surface  334  is concentric with a second longitudinal axis  404  that is offset from the first longitudinal axis  402 . It will be appreciated that the amount of eccentricity of the eccentric section  322  relative to the concentric section  318  may vary, and will depend on the desired range of adjustment of the component that is to be mounted. It will additionally be appreciated that although the second circumference, at least in the depicted embodiment, is less than the first circumference, this is merely exemplary of one embodiment. Indeed, in other embodiments, if needed or desired to match component dimensions, the second circumference could be equal to or greater than the first circumference. 
     The lock interface section  324  extends from the concentric section second end  328 , and is configured to be disposed within the bushing engagement opening  312  of the locking plate  302 . The lock interface section  324  includes an outer surface  336  that is defined by a plurality of second serrations  338 . As with the first serrations  314 , it will be appreciated that the configuration and number of second serrations  338  may vary, though the configuration and number should be equal to that of the first serrations  314 . Thus, in the depicted embodiment the second serrations  338  are configured as twelve evenly spaced, and generally triangle-shaped protrusions that extend radially outwardly away from the lock interface section  324 . As depicted most clearly in  FIG. 3 , each of the second serrations  338  engages one of the first serrations  314 , thus allowing the bushing  304  to be locked in a plurality of different rotational positions. With the depicted configurations of the first and second serrations  314 ,  338 , the bushing  304  may be locked in 24 different rotational positions (i.e., at every 15-degrees of rotation). 
     The depicted lock interface section  324  also has a plurality of slots  342  formed therein. The slots  342 , which may vary in size, shape, and configuration, are each configured to be engaged by an adjustment tool. As will be explained momentarily, an adjustment tool is used to rotate the bushing  304  to a desired rotational position, so that it may then be locked in place using the locking plate  302 . Before doing so, however, it is noted that the bushing  304  may be implemented with one or more additional concentric sections. The additional concentric section(s), if included, extend from the eccentric section  322 , and is (are) concentric with the concentric section  318 . An exemplary embodiment of a bushing  304  that includes an additional concentric section  502  is depicted in  FIG. 5 . Although the additional concentric section  502  in the depicted embodiment has a circumference that is less than both the concentric section  318  and the eccentric section  322 , in other embodiments its circumference may be equal to or greater than either or both of these sections. 
     Turning now to  FIG. 6 , when the bushing  302  is used to mount the actuator  102  (or other component), it is disposed into and through the first opening  212  in the first arm  206  of the clevis  104 , and into and through the mount opening  204  in the actuator  102 . The mount lug  216  is then disposed into and through the opening  326  in the bushing  302 , and into and through the second opening  214  in the second arm  208 . The bushing  304  is then rotated to a desired position, preferably via a suitable adjustment tool inserted in the slots  342  in the lock interface section  324 . As the bushing  304  is rotated, the eccentric section  322 , which extends through the mount opening  204  in the actuator  102 , will shift the actuator  102  in either a first direction  602  or a second direction  604 . 
     The bushing  304  may be rotated such that the central axis of the mount opening coincides with the central axis of the openings in the clevis, or such that the central axis of the mount opening is offset from the central axis of the openings in the clevis. In  FIG. 6 , the axes are coincident, and are thus illustrated with a single line  606 . In  FIGS. 7 and 8 , however, the axes are offset. In particular, in  FIG. 7  the central axis  702  of the mount opening is offset from the central axis  704  of the openings in the clevis in the first direction  602 , and in  FIG. 8  the central axis  702  of the mount opening is offset from the central axis  704  of the openings in the clevis in the second direction  604 . In any case, after the bushing  304  is rotated to the desired position, and as depicted in  FIG. 2 , the locking plate  302  is installed onto the lock interface section  324 , and the boss  316  is inserted into the lock opening  222 . 
     The precision adjustment of the component mount position that is obtainable using the adjustable and lockable bushing assembly  220  is also illustrated in  FIG. 9 , which depicts the first longitudinal axis  402 , various rotational positions  902  of the eccentric section  322 , and the resultant actuator lengths  904  at four different rotational positions. 
     The adjustable and lockable bushing assembly described herein is relatively simple, non-complex, and inexpensive mounting hardware that provides adjustable component mounting capability to compensate for manufacturing and assembly tolerances. 
     While at least one exemplary embodiment has been presented in the foregoing detailed description of the invention, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment of the invention. It being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the invention as set forth in the appended claims.