Abstract:
A device and method for twisting a work piece about an axis. The device includes first and second linear actuators attached to opposite sides of a shaft. The device also includes a first clamp attached to the shaft and a second clamp aligned with the first clamp along the axis. The first clamp is disposed between the linear actuators and the second clamp. Movement of the first and second linear actuators causes the shaft and first clamp to rotate about the axis while the second clamp remains in a fixed position. The method includes the steps of retaining a work piece within the first and second clamps, activating the first and second linear actuators in opposite directions causing the first clamp to rotate about the axis, and maintaining simultaneously the second clamp in a first position, whereby the work piece is twisted along the axis.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    Not applicable 
       REFERENCE REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not applicable 
       SEQUENTIAL LISTING 
       [0003]    Not applicable 
       BACKGROUND OF THE INVENTION 
       [0004]    1. Field of the Invention: 
         [0005]    The present invention relates to a machine for forming a work piece by twisting, such as the formation of industrial mixer or blender components. 
         [0006]    2. Description of the Background of the Invention: 
         [0007]    Devices for twisting and de-twisting work pieces have been known in the art for some time. One twisting device utilizes an electric or hydraulic motor to helically twist a plurality of metal rods. Two clamps, which are specially formed to match the shape of the rods, are attached to and securely hold opposite ends of each rod. Thus, if three rods are to be twisted together, six clamps are required. The clamps on one end of the rods remains stationary during the twisting operation, while the clamps on the other end are rotated either in a clockwise or counterclockwise motion. That is, if three rods are to be twisted, three clamps located on the same side of the rods remain stationary, and on the other end of the rods, the middle rod is rotated in one direction, e.g., counter-clockwise, and each of the two outside rods are rotated in the opposite direction, e.g., clockwise. 
         [0008]    Another twisting device uses a rotary actuator that is a dual acting rack and pinion system to twist a bus conductor for use in an electrical system. The device includes a holding mechanism to maintain one end of the bus conductor in a stationary position during the twisting operation. The other end of the bus conductor is inserted into an opening in a cylindrical sleeve that is contained within the rotary actuator. The opening of the cylindrical sleeve is formed to accommodate the size and shape of the bus conductor to be twisted. The cylindrical sleeve is rotated by the rotary actuator, which causes the bus conductor to twist. 
         [0009]    A third twisting device uses hydraulic cylinders to twist an airplane propeller blade. The device contains first and second clamps, both of which have a frame of a set size and shape. One end of the propeller blade is inserted into the frame of the first clamp, and the other end is inserted into the frame of the second clamp. The first clamp remains in a stationary position, while the second clamp is rotated in either a clockwise or counter-clockwise direction. Two hydraulic cylinders are attached to opposite sides of the second clamp and extend downwardly from the second clamp. To twist the propeller blade, one hydraulic cylinder pushes up on one side of the second clamp, while the other hydraulic cylinder pulls down on the other side of the second clamp. 
         [0010]    Devices for de-twisting a work piece generally involve the straightening of extruded metal sections that have assumed a slight twist (deformity) during the formation process. One such device uses a hydraulic actuator attached to a twisting apparatus to straighten the metal section by twisting the metal section in the opposite direction as the deformity. One end of the metal section is inserted into and rigidly retained by a carriage and the other end is inserted into a cylindrical twisting apparatus disposed horizontally and on the same axis as the metal section. The hydraulic actuator is attached perpendicularly to the side of the twisting apparatus and upon actuation of the hydraulic actuator the cylindrical twisting apparatus is rotated, thereby correcting the deformity. 
         [0011]    One limitation of the devices discussed above, however, is that the devices do not readily accommodate work pieces that are heavy or of varying size or shape. Another limitation of these devices is that the devices are configured to handle specific types of metal pieces such as metal rods or propellers, not metal pieces that are irregularly shaped and/or wider than the mechanisms used to retain and twist the metal piece. 
         [0012]    The present invention seeks to improve upon the prior art through the use of an improved design for a machine for twisting a work pieces that enables efficient twisting of large, heavy, and varied shaped metal pieces. 
       SUMMARY OF THE INVENTION 
       [0013]    In one aspect of the invention, a device for forming a work piece comprises first and second linear actuators disposed within a plane and movably attached to opposite sides of a shaft having an elongated axis that extends out from the plane. A first clamp is attached to the shaft and is spaced from the plane along the axis. A second clamp is aligned with the first clamp along the axis, wherein the first clamp is disposed between the linear actuators and the second clamp. Movement of the first and second linear actuators causes the shaft and first clamp to rotate about the axis while the second clamp remains in a fixed position. 
         [0014]    In another aspect of the invention, a method of twisting a work piece with a device is disclosed. The device comprises first and second linear actuators disposed within a plane and movably attached to opposite sides of a shaft having an elongated axis that extends out from the plane, a first clamp attached to the shaft, the first clamp being spaced from the plane along the axis, a second clamp aligned with the first clamp along the axis, wherein the first clamp is disposed between the linear actuators and the second clamp. The method comprises the steps of retaining a work piece within the first clamp and the second clamp, and activating the first and second linear actuators. The first and second actuators move in opposing directions thereby causing the first clamp to rotate about the axis. The method further comprises the step of maintaining simultaneously the second clamp in a first position, whereby the work piece is twisted along the axis between the first and second clamps. 
         [0015]    Other aspects and advantages of the present invention will become apparent upon consideration of the following detailed description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]      FIGS. 1A and 1B  are partial isometric views of a device for forming a work piece showing a work piece being twisted according to the present invention; 
           [0017]      FIG. 2  is a left side elevational view of the device of  FIG. 1 , the right side being a mirror image thereof; 
           [0018]      FIG. 3  is a cross-sectional view of the device along the lines  3 - 3  of  FIG. 2 ; 
           [0019]      FIG. 4  is a cross-sectional view of the device along the lines  4 - 4  of  FIG. 1 ; 
           [0020]      FIG. 5  is a back view of the device of  FIG. 1 ; and 
           [0021]      FIGS. 6A and 6B  are enlarged detail views of linear actuators of the device shown moving in a clockwise motion in  FIG. 6A  and a counter-clockwise motion in  FIG. 6B . 
       
    
    
     DETAILED DESCRIPTION 
       [0022]    Turning now to the drawings, device  10  for twisting work piece  12  along longitudinal axis  14 , such as a blank for a paddle or post, is shown.  FIG. 1A  illustrates work piece  12  clamped in device  10  prior to twisting, and  FIG. 1B  illustrates device  10  in the process of twisting work piece  12 . 
         [0023]    Device  10  includes high-weight bearing steel frame  16  having vertical component  18  and horizontal component  20 . Vertical component  18  comprises two vertical beams  18   a,    18   b , and horizontal component  20  comprises two horizontal beams  20   a,    20   b.  Vertical beams  18   a  and  18   b  are the same size and shape and are disposed parallel to each other. Likewise, horizontal beams  20   a  and  20   b  are the same size and shape and are disposed parallel to each other. Two legs  22  and  24  extend down from the front end of horizontal beams  20   a,    20   b,  thereby providing added support and stability to frame  16 . The various beams are preferably steel beams such as C-beams, I-beams, or the like. 
         [0024]    Vertical component  18  further comprises two upper beams  26 ,  28 , front support plate  30 , back support plate  32 , front lower beam  34 , and back lower beam  36 . Upper beam  28  is spaced above and parallel to upper beam  26 . Both upper beams  26  and  28  are attached on one end to vertical beam  18   a  and on the other end to vertical beam  18   b.  Upper beams  26 ,  28  also comprise front faces  38  and  40 , respectively. 
         [0025]    Front and back lower beams  34 ,  36  are disposed parallel to each other. Front lower beam  34  is attached to the front side of vertical beams  18   a  and  18   b  and back beam  36  is attached to the back side of vertical beams  18   a  and  18   b.  Front and back lower beams  34 ,  36  support horizontal beams  20   a  and  20   b,  which are attached to an inner side of vertical beam  18   a  and an inner side of vertical beam  18   b.  The various beams may be attached by any suitable known method, such as by welding, bolting, or riveting. 
         [0026]    First tie rod bracket  42  is attached via bolts to the center of front face  40  of upper support beam  28 , and vertical hinge  44  is attached via bolts to the center of front face  38  of upper support beam  26 ; thus first tie rod bracket  42  is aligned vertically with vertical hinge  44 . Vertical hinge  44  is also connected to one end of jib crane  46  via a plate and bolts. Jib crane  46  extends perpendicularly out from vertical component  18 . Disposed on the other end of jib crane  46  is second tie rod bracket  48 , which is attached to jib crane  46  via bolts. First tie rod bracket  42  is attached to second tie rod bracket  48  via tie rod  50 . First tie rod bracket  42  is hingedly movable about vertical hinge  44  such that jib crane  46  is able to swing from right to left and left to right in a horizontal arc-shaped path. 
         [0027]    Disposed below upper beam  26  is front support plate  30  and back support plate  32 . Front and back support plates  30 ,  32  are identical and disposed parallel to each other. Front support plate  30  is attached to the front side of vertical beams  18   a  and  18   b  and back support plate  32  is attached to the back side of vertical beams  18   a  and  18   b.  Two bore holes  52   a  and  52   b  are disposed through front support plate  30  and align with bore holes  54   a  and  54   b,  respectively, which are disposed through back support plate  32 . First and second hydraulic cylinders  56 ,  58  are disposed between and hang down from front and back support plates  30 ,  32 . 
         [0028]    At one end of first hydraulic cylinder  56  is hole  60  and at one end of second hydraulic cylinder  58  is hole  62 . First hydraulic cylinder  56  is connected to front and back support plates  30 ,  32  via pin  64 , which extends through holes  52   a,    60 , and  54   a.  Second hydraulic cylinder  58  is connected to front and back support plates  30 ,  32  via pin  66 , which extends through holes  52   b ,  62 , and  54   b.    
         [0029]    Disposed at the other end of first and second hydraulic cylinders  56 ,  58  are pistons  68  and  70 , respectively. On an end of piston  68  opposite first hydraulic cylinder  56  is bore  72  and, on the end of piston  70  opposite second hydraulic cylinder  58  is bore  74 . Pistons  68  and  70  are attached to front rotator plate  76  and back rotator plate  78 . Front and back rotator plates  76 ,  78  are substantially identical to each other. Front rotator plate  76  contains two outer apertures  80   a  and  80   b  disposed at opposite lateral ends thereof and one central aperture  82  located in the center thereof. Likewise, back rotator plate  78  contains two outer apertures  84   a  and  84   b  disposed at opposite lateral ends thereof and one central aperture  86  located in the center thereof. Piston  68  is attached to front and back rotator plates  76 ,  78  with pin  88 , which extends through aperture  80   a,  bore  72 , and aperture  84   a.  Piston  70  is attached to front and back rotator plates  76 ,  78  with pin  90 , which extends through aperture  82   b,  bore  74 , and aperture  84   b.    
         [0030]    Cylindrical shaft  92  is disposed through central apertures  82  and  86  of front and back rotator plates  76 ,  78 , respectively, and securely attached thereto, such as by welding. Shaft  92  comprises front portion  94 , front end  96 , and back portion  98 . Additionally, shaft  92  defines and/or is aligned on longitudinal axis  14 , which is preferably horizontal. 
         [0031]    Shaft  92  is maintained in position along axis  14  by front bushing  100  and back bushing  102 . Front portion  94  of shaft  92  passes through and is rotatably retained in front bushing  100 , and back portion  98  of the shaft passes through and is rotatably retained in back bushing  102 . Front and back bushings  100 ,  102  are fixedly attached to front and back support beams  104  and  106 , respectively, which are offset from vertical beams  18   a  and  18   b.  Front and back support beams  104 ,  106  are attached parallel each other to top faces  108   a,    108   b  of horizontal beams  20   a  and  20   b,  respectively. 
         [0032]    Preferably, front and back bushings  100 ,  102  are identical. Front and back bushings  100 ,  102  are split bushings, wherein each has top portion  110  and bottom portion  112 , which are attached via bolts. Split bushings  100 ,  102  enable shaft  92  to be easily mounted into and removed from frame  16 , such as for assembly and/or maintenance. 
         [0033]    Fixedly attached to front end  96  of shaft  92  is paddle clamp assembly  114 . Paddle clamp assembly  114  includes backboard  116  attached to shaft  92 , platform  118  extending out from the bottom of backboard  116 , and paddle clamps  120 ,  122  disposed at the end of platform  118 . Paddle clamps  120 ,  122  are therefore longitudinally offset from first and second hydraulic cylinders  56 ,  58  and vertical component  18  of frame  16  along axis  14 . 
         [0034]    As best seen in  FIG. 2 , secondary support frame  124  is attached at various points to vertical component  18  and horizontal component  20  of frame  16 . Secondary support frame  124  is provided for stability and extra support of vertical component  18  and jib crane  46 . 
         [0035]    Movable carriage  126  is disposed on horizontal beams  20   a  and  20   b  between platform  118  and legs  22  and  24 . Carriage  126  is rotationally fixed; however, carriage  126  is longitudinally slidable on horizontal beams  20   a  and  20   b  along axis  14 . On a top portion of carriage  126  is post clamp assembly  128  including post clamps  130  and  132 . (Note that portions of post clamp  130  are not shown in  FIGS. 1A and 1B  for clarity.) Post clamps  130 ,  132  and paddle clamps  120 ,  122  are aligned horizontally and longitudinally spaced apart along axis  14 . Because carriage  126  is rotationally fixed, post clamps  130 ,  132  are also rotationally fixed about axis  14 . Horizontal hydraulic cylinder  134  is attached to the bottom portion of carriage  126  and to front lower beams  34 . Actuation of horizontal hydraulic cylinder  134  moves carriage  126  forward and/or backward along horizontal beams  20   a  and  20   b  and axis  14 .  FIG. 3  shows carriage  126  and post clamps  130 ,  132  in backward position  136  and forward position  138  (shown in dashed lines). 
         [0036]      FIGS. 6A and 6B  show detailed views of first and second hydraulic cylinders  56 ,  58  and front rotator plate  76  (the back rotator plate  78  being identical thereto).  FIG. 6A  illustrates the movement of first and second hydraulic cylinders  56 ,  58  in a clockwise direction and  FIG. 6B  illustrates movement in a counter-clockwise motion. Preferably, first and second hydraulic cylinders  56 ,  58  rotate shaft  92  at least fifty-five degrees from a horizontal in both clockwise and counter-clockwise directions in a controllable manner. 
         [0037]    In use, work piece  12  is lifted by jib crane  46  and lowered on to carriage  126 . Once on carriage  126 , work piece  12  is secured in post clamps  130 ,  132 . Horizontal hydraulic cylinder  134  is activated, thereby moving carriage  126  from backward position  136  to forward position  138  so that work piece  12  can be secured within paddle clamps  120 ,  122  and aligned to axis  14  with the help of laser alignment tool  140 . Depending on the size of work piece  12 , use of jib crane  46  and/or activation of horizontal hydraulic cylinder  134  may not be required. 
         [0038]    After work piece  12  is appropriately positioned and secured in paddle clamps  120 ,  122 , first and second hydraulic cylinders  56 ,  58  are actuated in opposite directions, which rotates front and back rotator plates  76 ,  78 , shaft  92 , and paddle clamps  120 ,  122  about axis  14 , while shaft  92  is rotably retained by front and back bushing supports  100 ,  102 . Because post clamps  130 ,  132  remain fixed while paddle clamps  120 ,  122  rotate, work piece  12  is thereby axially twisted between post and paddle clamps about axis  14 . Paddle clamps  120 ,  122  can be rotated up to fifty-five degrees from the horizontal in either rotational direction, and manual angle detector and/or inclinometer  142  provides feedback to an operator regarding the angular degree of twist imparted to work piece  12 . Once an appropriate twist is obtained, first and second hydraulic cylinders  56 ,  58  are stopped, paddle clamps  120 ,  122  are released, and horizontal hydraulic cylinder  134  is activated to slide carriage  126  away from paddle clamps  120 ,  122 , back to its starting position  136 , thereby enabling for the easy removal of now-twisted work piece  12 ′. Now-twisted work piece  12 ′ is then released and removed from post clamps  130 ,  132 . 
       INDUSTRIAL APPLICABILITY 
       [0039]    A machine that can twist work pieces of varying weights, sizes, and shapes as disclosed herein creates a new configuration that addresses problems encountered by the traditional art. For example, off-setting the paddle clamps from the first and second hydraulic cylinders enables large and irregularly shaped work pieces to be twisted. In addition, the structural design of the frame, jib crane, and carriage enable heavy work pieces to be twisted.