Abstract:
An overhead conveyor includes a rotator system for rotating a work piece as it travels along a conveying track. A carrier movable along the track is propelled by an endless conveyor chain disposed within said track. The carrier is detachably connected to the chain and includes an uncoupling assembly for detaching the carrier from the chain. A support post extends upwardly from an upper surface of the carrier and an upper portion of the support post is attached to an upper arm of a C-shaped load arm. The C-shaped load arm is provided with a lower arm having a rotatable platter attached thereto. A camming pin is fixedly attached to said platter and a camming assembly is affixed to an underside of the track wherein the track is provided with flanges to receive said camming pin. Upon engagement of the camming pin with the flanges of the track, the platter is rotated a preselected amount.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This patent application claims the filing date of provisional patent application 60/195,939 filed Apr. 10, 2000. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an overhead conveyor rotator system, and more particularly to an overhead conveyor rotator system having at least one carrier moving within a track, wherein the carrier includes a rotating portion thereof which is engaged by a track-side g13 camming system thereby rotating the rotating portion through a preselected angle of rotation to include 90 degrees. 
     2. Description of Related Art 
     Conveying systems are typically used in manufacturing facilities to move work pieces through work stations, and from work station to work station, along a preselected path. There are a number of conveying systems for moving work pieces from work station to work station which include a conveyor moving at a preselected speed with carriers coupled for movement therewith between work stations and uncoupled from the conveyor so that they will be stationary at the work station while work is performed on a work piece carried by the load carrying units. Examples of patents directed to such conveying systems include U.S. Pat. No. 4,438,702; U.S. Pat. No. 4,644,869; U.S. Pat. No. 4,638,740; and, U.S. Pat. No. 4,770,285. 
     In general, and especially when a conveyor system utilizes curved track, consideration must be given to friction and associated increased loads placed upon propulsion machinery and load-bearing structures. Such load-bearing structures include rolling wheels and sliding chains. Current systems suffer from increased maintenance intervals and associated down-time for repair and replacement of worn parts. Current carriers are especially prone to frequent replacement of rolling structure, such as wheels and rollers due to rubbing, as such rolling structure travels along conveyor track and must navigate curves, inclines, and other high-friction areas. 
     Current uncoupling systems often require the use of sophisticated and expensive electronic detection and logic means. Mechanical means for accomplishing uncoupling are often unreliable, placing the work pieces moved about by the system at great risk of damage by inadvertent collision with other carriers. Additionally, if uncoupling is not highly predictable and highly reliable, work pieces can be left in a work area for either too long or too short a time, thereby resulting in undesirable results in work to be done, such as forming of surface contours, application of finishes, heating of finished surfaces, and the like. 
     Often times, best results can be obtained at a work station when a work piece is rotated through a preselected angle of rotation. Such rotation must also be highly predictable and highly reliable. Additionally, current rotation means often interfere with track construction, or require that special design consideration be given to including the track in a work station, yet insulating that same section of track from extreme heat, solvents, and the like. 
     Taken together, all the above described problems mitigate against a highly efficient conveyor means for automated movement of work pieces through work stations. Thus, there is a need for a conveyor rotator system which provides a carrier featuring reduced rubbing and other wear to rolling surfaces, makes good use of manufacturing floor space, provides for angular rotation of a work piece, and allows high reliability and efficiency in moving work pieces through work stations. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide a conveyor rotator system which includes a carrier which moves through a track with reduced rubbing and wear to its rolling components. 
     Another object of the present invention is to provide a conveyor rotator system which includes a hinged carrier to achieve reduced rubbing and wear to its rolling components. 
     A further object of the present invention is to provide a conveyor rotator system which includes a mechanically actuated uncoupling means. 
     Yet another object of the present invention is to provide a conveyor rotator system which includes a platter rotation means whereby a work piece is rotated through a preselected angle of rotation, thereby optimizing the utilization of manufacturing floor space. 
     More particularly, the present invention recognizes and addresses in a conveyor rotator system, the problems of frequent replacement of rolling structure such as wheels and rollers due to rubbing as such rolling structure travels along conveyor track and must navigate curves, inclines, and other high-friction areas; uncoupling which is not highly predictable and highly reliable; and, rotation of a work piece that is consistent in angular rotation desired and achieved while at the same time minimizing the contact of the conveyor system itself to include track and carrier, with the work stations. 
     Specifically, a conveyor rotator system is provided which includes: 
     a T-shaped track with three U-shaped channels connected to form an enclosure with an open top and having straight, curved, inclined, and reclined sections; 
     a propelling means, such as a chain, running along a chain channel of the track and connected to a propulsion source, such as a motor connected to a drive shaft having a cogged drive sprocket engaged to the chain; 
     a carrier moving inside of the track and including: 
     a front and back section connected to a pivoting middle section and joined together by pivot pins; 
     wheels affixed to side and bottom surfaces of the sections; 
     an uncoupling assembly including a chain engaging pin and an uncoupling bar connected by associated linkage to the pin; 
     a support post extending from an upper surface of the carrier and protruding through the open top of the track; 
     a C-shaped load arm supporting a platter; 
     a camming pin affixed to the platter; and, 
     a camming assembly affixed to the track and having flanges to receive and guide the camming pin, thereby rotating the platter a preselected amount. 
     Further objects and advantages of this invention will appear from the following description and appended claims, reference being had to the accompanying drawings forming a part of the specification wherein like reference characters designate corresponding parts into several views. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A better understanding of the invention will be had upon reference to the following description in conjunction with the accompanying drawings, wherein like numerals refer to like parts throughout the several views and wherein: 
     FIG. 1 is an end view of the track of the overhead conveyor rotator system of the present invention; 
     FIG. 2 is a perspective view of an overhead conveyor rotator system of the present invention; 
     FIG. 3 is an enlarged cut-away sectional view of the track of the overhead conveyor rotator system of the present invention taken along lines  3 — 3  in FIG. 2; 
     FIG. 4 is a side view of a carrier of the overhead conveyor rotator system with selected portions shown in phantom lines; 
     FIG. 5 is a bottom view of the load-carrying unit of FIG. 4 with selected portions shown in phantom lines; 
     FIG. 6 is an end view of a conveying system of the present invention showing a work piece transverse to movement along a conveyor path; 
     FIGS. 7A,  7 B, and  7 C show the sequence of events in turning a work piece from a first conveying position to the conveying path to a second conveying position with selected portions shown in phantom lines; and, 
     FIGS. 8A,  8 B, and BC show the sequence of events in stopping a carrier with selected portions shown in phantom lines and other sections shown in cut-away. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     As shown in FIG. 1, a track  20  is of T-shaped configuration with three U-shaped channels connected to form an enclosure with an open top. The three U-shaped channels are identified by the numerals  22 ,  24 , and  26 . Open top  28  is defined by terminating channel ends of channels  22  and  24 . The track  20  has straight, curved, inclined, and reclined sections, as desired, in order to route at least one work piece (not shown) mounted onto work piece support arm  110  (FIG. 2) through various preselected work stations (not shown). Camming assemblies  27   a  and  27   b  are affixed at selected locations to the underside of channel  26 . A chain channel  21  is formed on an interior surface of channel  26  and along a route defined by the track  20 . Multiple sections of track  20  are joined together by track flanges  23 . 
     As shown in FIGS. 2 and 3, a propelling means, such as, for example, a chain  30 , rests upon and runs along the chain channel  21 . The chain  30  is connected to a propulsion source, such as a motor  32  connected to a drive shaft  34  having a cogged drive sprocket  36  engaged to the chain  30 . 
     As shown in FIGS. 4-6, a load carrying unit or carrier  40  is retained inside of track  20  and moves along a route defined by the track  20 . The carrier  40  includes a front section  42  and a back section  44 , both sections  42  and  44  connected to a pivoting middle section  50  by pivot pins  46  and  48 , respectively. Four (4) Wheels  52  are affixed horizontally and located within channel  26 , along an underside surface of the carrier  40  in order to guide and steer the carrier  40  along its conveying path in the track  20 . Four (4) wheels  54  are vertically affixed in two pairs, one pair to each section  42  and  44  of the carrier  40 . Each pair of wheels  54  is connected by axles  56  which pass through sides of each section. Wheels  54  are load bearing in that they support the combined weight of all structure attached to the carrier  40  as well as the weight of the work piece (not shown). Wheels  54  are located within channels  22  and  24  of the track  20 . 
     Also provided is an uncoupling assembly  70  which includes a chain engaging pin  72  and a bumper or uncoupling bar  74  connected by associated linkage to the pin  72 . The pin  72  is slidably mounted within a pin tube  76  which is mounted within front section  42  and oriented such that the pin  72  moves vertically, engaging and disengaging, as desired, within links of the chain  30 . The uncoupling bar  74  is attached to a shaft  78  which extends rearward therefrom and is received within a sleeve  80  which is rotatably mounted within the front section and retained therein by a braking pivot pin  79  such that the bar  74  moves upwards and downwards, as desired, in order to cause vertical movement of the chain engaging pin  72 . A lifting bar  82  is affixed to the braking pin  79  and connected to one end of a two-force linkage  84 . The pin  72  has extending therefrom and through a corresponding slot formed in the pin tube  76 , a lifting tab  88  to which the other end of the two-force linkage  84  is joined. 
     As shown in FIG. 6, a load bearing assembly  90  includes a support post  91  which extends from an upper surface of the carrier  40  and protrudes through the open top  28  of the track  20 . In a preferred embodiment, a C-shaped load arm  92  is affixed at one end to the support post  91  and the other end receives a rotator tube  94  which is suspended below the track  20 . A rotator shaft  96  having a first end  98  and a second end  99  is rotatably mounted within the rotator tube  94 . A platter  100  is affixed to the first end  98  of the rotator shaft  96  and positioned above rotator tube  94  and below the camming assembly  27  of the track  20 . At least one camming pin, two being shown and identified as pins  102   a  and  102   b , is affixed to the platter  100  and oriented upwards. Pins  102   a  and  102   b  are slidably received and guided in sliding motion by flanges  29   a  and  29   b  of the camming assemblies  27   a  and  27   b  (FIG.  7 C), respectively. A work piece support arm  110  receives a work piece (not shown) and is affixed to the second end  99  of the rotator shaft  96  by a nut  112  which engages corresponding threads (not shown). The work piece support arm  110  thereby serves, along with the platter  100 , to retain the rotator shaft  96  within the rotator tube  94 . At least one indexing roller  104  is affixed to the rotator shaft  96 . The roller  104  correspondingly engages at least one indexing recess  106  formed along an upper surface of the rotator  94 . Recesses  106  are preferably formed circumferentially around the upper surface of the rotator  94  and spaced 90° apart. However, other angular spacings, such as, for example, every 45° are provided as desired. 
     As shown in FIGS. 7A,  7 B, and  7 C, the camming assembly  27   a  is affixed to the track  20 . Flanges  29   a  are spaced in parallel to receive and guide a camming pin  102   a , thereby rotating the platter  100  and the work piece support arm  110  through a preselected amount of rotation, preferably 90°. Moreover, as shown in FIG. 7C, a second camming assembly  27   b  is provided with flanges  29   b  to receive camming pin  102   b , also rotating the platter  100  and work piece through a preselected amount of rotation, again preferably 90°, thereby re-aligning the work piece to its original orientation. 
     As shown in FIGS. 8A,  8 B and  8 C, a braking assembly  120  is shown. Braking assembly  120  includes a hydraulic or pneumatic piston cylinder  122 , a piston rod  124 , an uncoupler actuator  126 , and a braking lever  128 . The braking assembly is affixed to a channel  22  or  24  of the track, as desired, and oriented thereupon such that when stopping of a carrier  40  is desired, the braking lever  128  rotatably extends down through opening  28  of the track  20  and correspondingly blocks passage of the uncoupling bar  74 . Stopping occurs as the carrier  40  moves past the braking assembly  120 , and the braking lever  128  is lowered by the cylinder  122  and rod  124 . Upon moving into contact with the braking lever  128 , the uncoupling bar  74  engages the uncoupler actuator  126 , thereby lowering the bar  74  whereby the pin  72  is raised, disconnecting the carrier  40  from the chain  30 . The carrier  40  is held in place and prevented from moving forwards by the braking lever  128 , and from moving backwards by the uncoupler actuator  126 . Particularly, the uncoupler actuator  126  is of a geometric configuration to include a spacing between a terminating edge  126   a  and the braking lever  128 . Moreover, the terminating edge  126   a  has a leading edge  126   b  which, as shown in FIG. 8C, engages pin  79  and in cooperating relation with braking lever  128  wedges pin  79  therebetween in a non-rotatable condition thereby preventing chain engaging pin  72  from engagement with the chain  30  until the braking lever  128  is raised. 
     In operation, a preferred overhead conveyor rotator system  10  operates as follows: 
     1. The work piece (not shown) is suspended from the work piece support arm  110 . 
     2. The motor is energized, thereby causing the chain  30  to move within the track  20 . 
     3. The carrier  40  moves along with the chain  30 , the pin  72  being in the down position. 
     4. When rotation of a work piece is desired at a particular work station (not shown), the camming assembly  27   a  or  27   b  is utilized. As shown in FIGS. 7A,  7 B, and  7 C, the camming assembly  27   a  affixed to track  20  and having flanges  29   a , receives and guides a camming pin  102 A, thereby rotating the platter  100  and the work piece support arm  110  through a preselected amount of rotation, preferably 90°. 
     5. Whenever stopping a carrier  40  is desired, the uncoupling assembly  70  in cooperation with a braking assembly  120  is utilized. As shown in FIGS. 8A,  8   b  and  8 C, stopping occurs as the carrier  40  moves past the braking assembly  120 , and the braking lever  128  is lowered by the cylinder  122  and rod  124 . Upon moving into contact with the braking lever  128 , the bar  74  engages the uncoupler actuator  126 , thereby lowering the bar  74  whereby the pin  72  is raised, disconnecting the carrier  40  from the chain  30 . The carrier  40  is held in place and prevented from moving forwards by the braking lever  128 , and from moving backwards by the uncoupler actuator  126 . 
     6. When a carrier  40  is to be allowed to proceed from a stopped position, the braking lever  128  is raised by the cylinder  122  and rod  124 , and the pin  72  is lowered back into engaging relation with the chain  30  and the carrier  40  moves along the track  20  once more. 
     Preferred embodiments allow the use of more than one track section  20  having chains  30  moving at different speeds, but abutting one another in series. Each track section  20  has its own continuous loop of chain  30 , motor  32 , etc. In this fashion, for example, a work piece (not shown) is allowed to progress at 21 feet per second in one track section  20 , and then slowed to 7 feet per second in a second track section  20 . A braking assembly  120  is inserted directly between the abutting track sections  20 . A carrier  40  is advanced forward to the second track section  20  by a known carrier  40  or load carrying units advancing means. This feature allows stacking of work pieces (not shown) between track sections  20 . When combined with the rotating features of the present invention, optimal use of space is achieved in storing and moving often times long and unwieldy work pieces (not shown) such as, for example, bed head boards, and the like. 
     The foregoing description is given primarily for clearness of understanding and no unnecessary limitations are to be understood therefrom for modifications will become obvious to those skilled in the art upon reading this disclosure and may be made without departing from the spirit of invention or scope of the appended claims.