Abstract:
A cable carrier chain having link sections that include metal and plastic portions to allow the chain to operate at high velocity yet also be suitable for high acceleration and deceleration and/or heavy load applications. The metal portions are “free floating” when the chain rotates around a pivot point to allow the plastic portions to flex, but become “locked out” when the chain is no longer rotating to provide sufficient strength to support the load of the chain.

Description:
CROSS-REFERENCE TO RELATED APPLICATION AND PRIORITY CLAIM 
     This application is based on and claims priority to U.S. Provisional Patent Application No. 62/291,250 filed on Feb. 4, 2016, which is incorporated herein by reference in its entirety for all purposes. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to the field of cable carrier chains. More particularly, the present invention relates to a cable carrier chain having a plastic portion and a steel portion. 
     BACKGROUND 
     Cable carrier chains, also called drag chains, energy chains, or cable chains surround and guide flexible cables or hoses. Typically, cable carrier chains are used in connection with articulated machinery which may or may not be automated. Cable carrier chains reduce wear and stress on the cables or hoses, prevent entanglement, and improve operator safety. Cable carrier chains come in a wide variety of sizes, from applications in small devices, up to very large industrial applications. Typical cable carrier chains have a rectangular cross section forming a cavity through which cables, hoses, or other flexible materials can pass. Spacer bars may be included along the length of the chain that can be opened to allow cables to be inserted or removed. Cable carrier chains may also include internal separators to separate the cables. 
     Cable carrier chains may be configured to bend or articulate in a wide variety of directions. Many cable carrier chains only permit bending in one direction, however, to further control the movement of the enclosed cables to prevent tangling or crushing of the cables. 
     Cable carrier chains are typically made of either metal or plastic, depending on the needs of the application. Size and material selection are also important to consider when selecting the right cable carrier chain for a particular application. 
     Metal chain sections are often made of steel and/or aluminum and distribute large stress and strain forces without buckling or shearing because of the chain section material has high mechanical strength properties. These forces are produced by moment forces acting on the chain sections. These moment forces can occur due to long unsupported spans, heavy distrusted loads, or high accelerations and decelerations acting on the chain sections. As described above, such unsupported spans often occur because the cable carrier chain may only permit bending in one direction. 
     Plastic chain sections absorb high impact forces without permanent deformation due to the high level of elasticity of plastic compared to metal. These impact forces are often the result of the chain sections being pushed and/or pulled at high velocities. However, the higher elasticity of plastic chain sections as compared to metal chain sections make them typically unable to reliably support long unsupported spans or heavy loads without unacceptable wear or, in some cases, failure. 
     No solution currently exists that combines the qualities of both metal and plastic cable carrier chains. As such, there is a need for a cable carrier chain that incorporates both metal and plastic parts to take advantage of the desirable properties of each type of chain. 
     SUMMARY 
     The present invention is a cable carrier chain having a cavity through which cables or hoses can pass. The cable carrier chain includes a plurality of alternating male pivot sections and female pivot sections, wherein the male and female pivot sections are rotatably and removably attached to each other to form a chain. 
     Each male pivot section has two side portions, which are separated by at least one spacer bar. A male support plate is removably attached to each side portion and includes at least one inner bearing flange. The side portion is made of a different material than the male support plate. 
     Similarly, each female pivot section has two side portions, which are separated by at least one spacer bar. A female support plate is removably attached to each side portion and includes at least one arcuate slot. Again, the side portion is a different material than the female support plate. 
     Each of the side portions includes at least one damper block that selectively engages at least one damper block on an adjacent side portion. The damper blocks are positioned to allow limited rotation of the pivot sections by engaging an adjacent damper block. Further, the damper blocks are positioned to engage an adjacent damper block before the bearing flanges engage the arcuate slots. Finally, the damper blocks made of a material that allows the damper bocks to elastically deflect under load until the bearing flanges engage inner arcuate slots. 
     It will be understood by those skilled in the art that one or more aspects of this invention can meet certain objectives, while one or more other aspects can lead to certain other objectives. Other objects, features, benefits and advantages of the present invention will be apparent in this summary and descriptions of the disclosed embodiment, and will be readily apparent to those skilled in the art. Such objects, features, benefits and advantages will be apparent from the above as taken in conjunction with the accompanying figures and all reasonable inferences to be drawn therefrom. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a portion of a hybrid cable carrier chain in accordance with the invention; 
         FIG. 2  is an exploded perspective view of a portion of the hybrid cable carrier chain of  FIG. 1 ; 
         FIG. 3  is an opposite side exploded perspective view of the hybrid cable carrier chain of  FIG. 2 ; 
         FIG. 4  is a side view of a hybrid cable carrier chain in accordance with one embodiment of the present invention shown in an unlocked position; 
         FIG. 5  is a side view of the hybrid cable carrier chain of  FIG. 4  shown in a locked position; 
         FIG. 6  is a front view of the interiors of two links of a hybrid cable carrier chain in accordance with one embodiment of the invention shown in an unlocked position; 
         FIG. 7  is a detail view of the interiors of the links of the hybrid cable carrier chain of  FIG. 6  taken generally along the line  7 - 7  in  FIG. 6 ; 
         FIG. 8  is another front view of the interiors of two links of the hybrid cable carrier chain of  FIG. 6  shown in a locked position; 
         FIG. 9  is a detail view of the interiors of the links of the hybrid cable carrier chain of  FIG. 8  taken generally along the line  9 - 9  in  FIG. 8 ; 
         FIG. 10  is another front view of the interiors of two links of a hybrid cable carrier chain in accordance with one embodiment of the invention shown in an unlocked position; 
         FIG. 11  is a detail view of the interiors of the links of the hybrid cable carrier chain of  FIG. 10  taken generally along the line  12 - 12  in  FIG. 10 ; and 
         FIG. 12  is another detail view of the interiors of the links of the hybrid cable carrier chain of  FIG. 10  taken generally along the line  12 - 12  in  FIG. 10  showing the links in a locked position. 
     
    
    
     DETAILED DESCRIPTION 
     The hybrid cable carrier chain of the present invention provides a solution that has the benefits of both metal and plastic chains, particularly in high velocity and/or high acceleration-deceleration application. The hybrid cable carrier chain is able to benefit from the properties of both metal and plastic chains by using chain links that include both plastic and metal components and selectively either material when desirable. 
       FIGS. 1-12  show one embodiment of a hybrid cable carrier chain  10  in accordance with the invention. As shown in  FIG. 1 , hybrid carrier chain  10  includes a plurality of pivot sections  100  that are connected to each other to form a chain. In the embodiment shown, two pivot sections  100  are integrally formed into links  101 . Each link  101  includes sides  102  that are connected to each other by spacer bars  104 , to form a cavity  105  through which cables, hoses, or any other flexible material can pass. The spacer bars  104  may be selectively opened or closed to allow cables to be inserted or removed from cavity  105 . The links  101  and spacer bars  104  may be of any suitable size or length without departing from the invention. In the embodiment shown, each pivot section  100  includes a pivot axis  106 . When pivot axes  106  of two adjacent pivot sections  100  are aligned, the pivot sections may be secured to each other using a locking hub  108 . At either end of the chain  10 , the last pivot section  100  may also be attached to an anchor point  110  (see  FIGS. 4-5 ). 
     Turning now to  FIG. 2 , an exploded view of two adjacent links  101  is shown. Unlike typical chains where each link is identical, the present invention includes side portions  112  and alternating male and female support plates  114 ,  116 . In the embodiment shown, side portions  112  are solid parts made of glass filled nylon but may alternatively be made of multiple parts of any other suitable material without departing from the invention. A plurality of damper blocks  122  extends from the side portions  112  and are positioned around pivot axes  106 . When side portions  112  are rotationally attached to each other to form a chain  10 , damper blocks  122  on adjacent pivot sections  100  align so that the pivot sections  100  can rotate a limited distance until adjacent damper blocks engage each other. Although damper blocks  122  have the general shape of pie slices in the present embodiment, the damper blocks may be any suitable shape without departing from the invention. 
     Support plates  114 ,  116  are removably attached to the links  101  by a plurality of fasteners  128 . As shown in  FIGS. 2-3 , support plates  114 ,  116  are substantially flat and include a plurality of mounting holes  130  though which fasteners  128  may pass. Threaded inserts  132  are included in side portion  112  that correspond to the locations of mounting holes  130 . Of course, alternative fasteners or fastening methods may be used to attach the support plates  114 ,  116  to side portion  112  without departing from the invention. In the embodiment shown, support plates  114 ,  116  are made of steel, but any suitable material may alternatively be used without departing from the invention. 
     Male support plate  114  further includes a plurality of bearing flanges  134  that are positioned around the pivot axes  106 . In the embodiment shown, three bearing flanges  134  are positioned concentrically around each pivot axis  106 , but additional or fewer bearing flanges may alternatively be used without departing from the invention. Further, the bearing flanges may alternatively be positioned non-concentrically around pivot axis  106 . As shown, the bearing flanges  134  are circular but any other suitable shape may also be used. Further, the bearing flanges  134  are punched through the male support plate  114 , but the holes shown in the present embodiment are not necessary to practice the invention. 
     Female support plate  116  includes a plurality of arcuate slots  136  that surround the pivot axes  106 . The location of the arcuate slots  136  corresponds to the position of the bearing flanges  134 , i.e., concentrically around pivot axis  106  in the present embodiment. When two links  101  are attached, the support plates  114 ,  116  are aligned so that the bearing flanges  134  travel through the arcuate slots  136  and selectively engage the sides of the arcuate slots. 
     In alternative embodiments, the features of the support plates  114 ,  116  may be combined so that all links  101  could be identical. For example, rather than each support plate providing only bearing flanges  134  or arcuate slots  136 , respectively, each plate could alternatively include bearing flanges  134  at one of the pivot sections  100  and arcuate slots  136  at the other pivot section. As such, any suitable combination of bearing features could be included in the support plates  114 ,  116  without departing from the invention. 
       FIGS. 4 and 5  show a hybrid carrier chain  10  supported between two anchor points  110 . The hybrid carrier chain  10  includes an unsupported section  124  and a curved section  126 .  FIG. 4  shows the unsupported section  124  in an “unlocked” position. When the cable carrier chain  10  is in the unlocked position, the support plates  114 ,  116  are “free floating.” Pivot sections  100  are also in the unlocked position whenever the pivot sections are rotating around the pivot axes  106 . In the unlocked position, none of the load  125  is supported by support plates  114 ,  116 . 
       FIG. 5  shows the unsupported section  124  in a “locked” position. In the locked position, the load  125  of the unsupported section has caused the damper blocks  122  to deflect slightly, which causes the bearing flanges  134  to engage the arcuate slots  136 , thereby transferring a portion of the load from the damper blocks  122  to the support plates  114 ,  116 . At this point the moment load acting on the chain sections is shared disproportionately between the damper blocks  122  and the support plates  114 ,  116 , thereby allowing the cable carrier chain  10  to handle greater moment loads caused by high accelerations-decelerations, and/or heavy loads. Importantly, before the load is transferred to the support plates the high elasticity of the damper blocks  122  relative to the support plates  114 ,  116  will dampen and disperse any impact forces before they act on the support plates. This prevents the support plates  114 ,  116  from being deformed due to impact forces. 
       FIGS. 6-12  show in greater detail the interplay between the damper blocks  122  and the support plates  114 ,  116  at different positions.  FIGS. 6-12  all show two pivot sections  100  that are attached at a pivot axis  106  by a locking hub  108 . 
       FIGS. 6 and 7  show pivot sections  100  in an unlocked position. The pivot sections  100  are positioned X° relative to each other. As shown in  FIG. 7 , in the unlocked position, damper blocks  122  on the pivot sections  100  are engaged and supporting a portion of the load, but bearing flange  134  is not engaged with arcuate slot  136  and the support plates  114 ,  116  are not bearing any of the load. 
       FIGS. 8 and 9  show pivot sections  100  in the locked position. In the embodiment shown, the pivot sections  100  are positioned parallel to each other, but the pivot sections  100  could be locked out at any desired angle without departing from the invention. When the pivot sections  100  are in the locked position, bearing flange  134  engages arcuate slot  136  to bear a portion of the load borne by the cable carrier chain  10 . Damper blocks  122  remain engaged, but have deflected slightly to allow the support plates  114 ,  116  to bear a portion of the load. 
       FIGS. 10-12  also show pivot sections  100  in a locked position consistent with curved section  126  as shown in  FIGS. 4 and 5 . Just as in the locked position described above and shown in  FIGS. 6-9 , as the pivot sections  100  rotate relative to each other in curved section  126 , damper blocks  122  begin to engage before the bearing features of the support plates  114 ,  116  engage. Damper blocks  122  then deflect slightly to allow bearing flange  134  to engage arcuate slot  136 , again causing the support plates  114 ,  116  to bear a portion of the load  125 . 
     Although the invention has been herein described in what is perceived to be the most practical and preferred embodiments, it is to be understood that the invention is not intended to be limited to the specific embodiments set forth above. Rather, it is recognized that modifications may be made by one of skill in the art of the invention without departing from the spirit or intent of the invention and, therefore, the invention is to be taken as including all reasonable equivalents to the subject matter of the appended claims and the description of the invention herein.