Abstract:
An apparatus and method for both rotating a cylinder about its center axis and translating the cylinder linearly along the same axis. The invention is suitable for X-raying rockets and other cylindrical objects. Multi-axis movement is accomplished by two sets of rollers: rotational and translational. The translational roller set is held in a retracted and unengaged position while the cylinder rests on the rotational roller set. Movement about the axis of the rotational roller set is allowed. When the translational roller set is engaged with the cylinder, the cylinder is disengaged from the rotational roller set, and movement about the axis is not allowed, but linear movement is allowed. The action may be reversed and repeated. The rollers or the cylinder may be powered by motor or manual device.

Description:
STATEMENT OF GOVERNMENT INTEREST 
     The invention described herein may be manufactured and used by or for the Government of the United States of America for Governmental purposes without the payment of any royalties thereon or therefore. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates generally to a conveying apparatus, and more particularly to a cart that enables both rotating a cylinder about its center axis and translating the cylinder linearly along the same axis. 
     2. Prior Art 
     Carts used to convey objects that are to be X-rayed, where the object is typically cylindrical in shape, have a mechanism that allows the object to be rotated, but require that the object be repositioned several times to obtain a complete set of X-rays, where there are no areas obstructed by the cart. In the case of rockets, the rocket requires linear translation in order to perform X-ray scans free of obstructed areas created by the rotational rollers. Scanning the rocket also requires it to be scanned sequentially from forward to aft, and this process requires multiple linear translations to complete an entire scan. Currently existing carts do not have a means of linear translation, and therefore an overhead crane is used to reposition the rocket. Repositioning the rocket with a crane is time consuming and cumbersome. 
     Another consideration is that every time the rocket is picked up there is a finite chance that it may be dropped, which at the least would damage the rocket. 
     An apparatus and method that eliminates the need for a crane would add safety to the process. 
     SUMMARY OF THE INVENTION 
     In an exemplary embodiment, the invention is a single location apparatus and method for both rotating a cylinder about its center axis and translating the cylinder linearly along the same axis. The apparatus can be mounted on a cart, and the cart with the apparatus is suitable for X-raying rockets and other cylindrical objects. 
     Multi-axis movement is accomplished by two sets of rollers: rotational and translational. The translational roller set is held in a retracted and unengaged position while the cylinder rests on the rotational roller set. Movement about the axis of the rotational roller set is allowed in this position. The translational roller set may, at anytime, be engaged with the cylinder, disengaging the cylinder from the rotational roller set. When this action occurs, movement about the axis of the rotational roller set is not allowed, but translational movement is allowed. Accordingly, the cylinder is moved to the desired position by either pushing on the cylinder or cranking the translational roller. The action may be reversed to once again, allow movement about the axis of the rotational roller set. The process may be repeated as needed. The rollers or the cylinder may be powered by motor or manual device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing invention will become readily apparent by referring to the following detailed description and the appended drawings in which: 
         FIG. 1  is a side view of a multi-axis cylinder manipulator apparatus; 
         FIG. 2  is a perspective overhead view of a concept version illustrating the relative position of the translational and rotational rollers; 
         FIG. 3  is a front view of the multi-axis cylinder manipulator apparatus illustrated in  FIG. 1 ; 
         FIG. 4  is a perspective overhead view of the multi-axis cylinder manipulator apparatus, illustrating the translational roller with a geared hand cranked shaft mounted on a movable plate stabilized with a plurality of guide struts that is springedly attached to one or more frame reinforcing elements, and one or more springs that assist to retract, fully, the translational roller after use; 
         FIG. 5  is an overhead view of a cart fitted with the multi-axis cylinder manipulator apparatus illustrated in  FIG. 4 , where the cylinder  100  is shown in ghost; and 
         FIG. 6  is a side view of the cart in  FIG. 5 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     An embodiment of the invention is shown and described in the attached drawings, where the invention includes a multi-axis cylinder manipulator apparatus, a cart or coupled carts forming a unified cart having the invented apparatus, and a method for utilizing the a multi-axis cylinder manipulator apparatus. 
     Referring to  FIGS. 1 ,  2  and  3 , the multi-axis cylinder manipulator apparatus  1  is mounted on a structurally rigid frame  10  having a top-side, a bottom side, and a plurality of lateral sides, where the frame has a length, a width and a thickness, and generally has a plurality of reinforcing elements  12 . There is a set of rotational rollers  20  mounted on the top-side of the frame  10 , where said rotational rollers have a sufficient hardness durometer, number of rollers, diameter, footprint width, positioning and ease of rotation to non-abrasively support a filled cylinder  100 , such as a rocket motor MK-70. The cylinder  100  is held horizontally at a height above the frame  10  of the manipulator apparatus, where the cylinder  100  is axially rotatable with minimal wear or grooving to the cylinder or to the rollers. The rotational rollers  20  have a rotational axis that is parallel to the cylinder&#39;s axis of rotational (see  FIG. 1 ). An opposing pair of rotational rollers  22  are spaced widthwise at a distance that is less than the diameter of the cylinder and longitudinally spaced close enough that, cumulatively, the set of rotational rollers  20 ,  22  provides a plurality of supporting forces, distributed over the cylinder  100 , such that rotation is facile. When the cylinder  100  undergoes linear movement, the cylinder does not come into contact with the frame  10  during any normal operation. 
     A set of translational rollers  30  is on the top-side  8  of the frame  10 . The set of translational rollers  30  enables linear movement of the cylinder  100 . A translational roller includes a durable self-centering elastic roller  32  on a shaft with an orthogonal axis of rotation. The translational roller is mounted on an upper portion of a movable plate  36  that can be raised with a jack  38  having a hydraulic piston  40  to an elevation sufficient in height that the cylinder  100  clears the translational rollers  30 . The members of the set of translational rollers  30  are used substantially simultaneously to elevate the cylinder to a height above the set of rotational rollers. In the elevation position, turning the translational rollers  30  moves the cylinder linearly to a different linear position on the multi-axis cylinder manipulator apparatus  1 . At the different linear position; the translational rollers are stopped and lowered, such that the cylinder  100  is supported by the set of rotational rollers  20  and is free to rotate. Process is repeatable until the cylinder has been moved to all the desired linear and rotational positions. 
     Referring to  FIG. 4 , which is a perspective overhead view of the multi-axis cylinder manipulator apparatus  1 , illustrating the translational roller  30  with a geared hand cranked shaft  35  mounted on a movable plate  36  stabilized with a plurality of guide struts  42 . The movable plate  36  is springedly attached to one or more frame reinforcing elements  12 . 
     The translational roller  30  has a durable self-centering rubber roller that includes a pair of opposing, substantially conical portions  33  having a larger diameter and a smaller diameter, where the smaller diameter of the conical portions are proximate, producing a sloped channel for the cylinder, which makes the roll self-centering for the cylinder. The crank  34  is geared down through a gear box  44  to make the roller  30  easier turn. In the illustrated exemplary embodiment, the translational roller  30  is in the lowered position. The movable plate  36  can be raised or lowered through a hydraulic piston  38  in communication with a hydraulic pump  52  and handle  54  (see  FIGS. 5 and 6 ). 
     Referring to  FIGS. 5 and 6 , the multi-axis cylinder manipulator apparatus  1  and a moveable platform are integrally combined as a multi-axis cylinder manipulator cart  90 . The multi-axis cylinder manipulator cart  90  includes: a structurally rigid frame  10  having a top-side, a bottom side, and a plurality of lateral sides, where the frame has a length, a width, a thickness, and a plurality of reinforcing elements. A set of rotational rollers  20  (see  FIG. 2 ) is mounted on the top-side of the frame. They have a sufficient hardness durometer, number of rollers, diameter, footprint width, positioning and ease of rotation to non-abrasively support a filled cylinder  100  held horizontally at a height above the frame  10  of the manipulator cart  90 . The cylinder  100  (shown in ghost) is axially rotatable with minimal wear or grooving to the cylinder or to the rollers. The rotational rollers  20 , (as shown in detail in  FIG. 1 ) have a rotational axis that is parallel to the cylinder&#39;s axis of rotational, where an opposing pair of rotational rollers  22  (as shown in detail in  FIG. 4 ) are spaced widthwise at a distance that is less than the diameter of the cylinder and longitudinally spaced close enough that, cumulatively, the set of rotational rollers provides a plurality of supporting forces, distributed over the cylinder. 
     Rotation is facile, and can for most cylinders be effected manually. The rotational roller are sufficient in number that even when the cylinder is being loaded, unloaded or repositioned linearly, the cylinder does not come into contact with the frame during any normal operation. A set of translational rollers  30  (see  FIG. 2 ) is on the top-side of the frame  10 . The set of translational rollers enables linear movement of the cylinder. The illustrated translational roller is a durable self-centering elastic roller on a shaft  35  (as shown in detail in  FIG. 4 ) with an orthogonal axis of rotation. The translational roller is mounted on an upper portion of a movable plate  36  (see  FIG. 3 ) that can be raised to an elevation sufficient in height that the cylinder clears the rotational rollers. 
     The set of translational rollers are used substantially in tandem to elevate the cylinder to a height above the set of rotational rollers. In the elevated position the translational rollers can be turned (e.g.; rotated) to transpose the cylinder linearly to a desired position on the cart. At the desired position the translational rollers is stopped therein stopping the cylinder at the desired position, where they are normally lowered, such that the cylinder is again supported by the set of rotational rollers and is free to be rotated. The cart has a set of repositioning elements on the bottom side of the frame, where the repositioning elements  60 ,  60 ′ facilitate movement of the cart, either loaded with a cylinder or unloaded. The cart is generally moved for storage but never while loaded with a rocket for safety reasons. 
     The set of repositioning elements is selected from the group consisting of casters, skids, bearings, tracks, wheels, air floatation devices, rail wheels, and the like. Heavy duty casters have been found to be suitable for concrete floors. 
     In  FIG. 6 , the cart may also include stanchions  70  that emanate upward from the frame. The stanchions help align the cylinder  100  with the set of translational rollers and the rotational rollers. The stanchions exist to guide a rocket or during initial placement on cart via an overhead crane. As a side benefit, the stanchions would also restrain the cylinder if the cart is moved. The stanchions  70  have a bumper  72  of an elastic material. 
     The illustrated cart has at lease one handle  62  for pushing or pulling the cart. Translation and rotation can be augmented with a motor  66  or sometimes referred to as a gear reduction box  66 , as, in an exemplary embodiment, the related drive system is a hand driven wheel involving a crank handle. 
     In one exemplary embodiment, the frame has coupling elements  68  for joining one multi-axis cylinder manipulator cart to another multi-axis cylinder manipulator cart. For operation of the translational roller, the carts must be joined with a minimum of two translational rollers required per setup. The two halves improve both storage efficiency and ease of transportation in/out of storage. The numbers  60  and  60 ′ indicate a coupled pair of carts, where the repositioning elements  60  and  60 ′ are similar, just on different portions of the unified cart. 
     Potentially, more carts could be employed to provide a higher aspect cart having longer linear movement. The higher aspect cart has a plurality of multi-axis cylinder manipulator smaller carts that are joined. 
     illustrated invention is excellent for taking x-rays of rocket motors, such as a MK-70 rocket motor. The entire length of the rocket may be x-rayed in three (3) different rotational positions. The MK-70 rocket motor is small enough that using the disclosed manipulator, it may be manually handled for both rotation and linear translation. The rotational rollers are turned by-hand using the rocket&#39;s motor case as a gripping surface. The linear rollers are also turned by-hand, but utilize a 20:1 gear reducer  44  (see  FIG. 4 ), and a 12 inch diameter hand crank  34 . For packaging reasons, the linear/translational roller is required to be made smaller than the rotation rollers. This exemplary configuration decreases the mechanical advantage and to activate the roller, requires the mechanical advantage of the gear reduction box  66 , including the related drive system. The crank handle and gear reducer decrease the input force required to an ergonomically acceptable level. The engaging mechanism for the current use of the invention utilizes a hydraulic cylinder jack and respective return springs  41 . The jack  38  is engaged by use of a hand pump. 
     Certain features disclosed in the embodiment have a dimensional relationship to the cylinder diameter, allowing for adaptation of the invention to any size cylinder. Some or all of the rollers as well as the engaging actuator (hydraulic jack in the current implementation) may be driven by a motor force. The motor driven invention could be utilized by automated through computer control. 
     The method for X-raying a rocket motor includes the steps of providing a multi-axis cylinder manipulator cart; positioning translational rollers in an elevated first linear position; loading the rocket; lowering the translational rollers; rotating the rocket on rotational rollers to a first X-ray position; X-raying the rocket; elevating the translational rollers; moving the rocket linearly to a second linear position; elevating the translational rollers; rotating the rocket to a second X-ray position; and repeating the linear and rotation positioning as necessary to complete the X-ray. The rocket is loaded using a crane. The positioning can be done manually or automated. 
     It is to be understood that the foregoing description and specific embodiments are merely illustrative of the best mode of the invention and the principles thereof, and that various modifications and additions may be made to the invention by those skilled in the art, without departing from the spirit and scope of this invention, which is therefore understood to be limited only by the scope of the appended claims. 
     Finally, any numerical parameters set forth in the specification and attached claims are approximations (for example, by using the term “about”) that may vary depending upon the desired properties sought to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of significant digits and by applying ordinary rounding.