Patent Publication Number: US-2019178441-A1

Title: Conveyor control component mounting

Description:
BACKGROUND OF THE INVENTION 
     The present invention is directed to a technique for mounting a control component to a conveyor and, in particular, to mounting a control component to the side-channel of the conveyor. Conveyors are difficult to assemble. There are small spaces that are difficult to access with tools, and the conveyor defines a rugged operating environment that requires robust assembly to avoid the need for frequent maintenance. Various assembly techniques use mechanical fasteners. These can be difficult to attach especially with the difficulty of accessing small spaces. 
     SUMMARY OF THE INVENTION 
     The present invention overcomes the difficulties associated with the use of permanent magnets to mount control components to a conveyor side-channel. In particular, the present invention recognizes that permanent magnets are good at attracting a housing to a ferromagnetic member, but have drawbacks that have prevented their use in the rugged environment of a conveyor. While the invention is illustrated for use in mounting a control component to a side-channel of the conveyor, it should be understood that it is useful for mounting to any ferromagnetic portion of the conveyor. 
     A conveyor system, control assembly used with the conveyor system, and method of assembling a control assembly to a member made of ferromagnetic material, according to an aspect of the invention, includes the control assembly having a control housing that houses at least one control component that is adapted to perform a control function. A support mechanism supports the control housing with the member. The support mechanism includes at least one permanent magnet mounted at a surface of the control housing that is adapted to attract the housing to the ferromagnetic material of the member and a positioning feature. The positioning feature resists movement of the housing with respect to the member. 
     The ferromagnetic material may be a side rail of the conveyor system having a pair of spaced apart longitudinally extending side-channels and a conveying surface between said side-channels. The support mechanism may include a stem that extends from the housing through an opening in the side-channel and a positioning plate that has a cutout that is configured to resist rotation of the stem with respect to the positioning plate when in the cutout. The positioning plate may include at least one other permanent magnet mounted at a surface thereof that is adapted to attract the plate to the side-channel. This resists rocking of the control housing along the length of the stem. The positioning plate may be mounted to a surface of the side-channel that is opposite to the surface supporting the control housing. The side-channel may have a bend adjacent the side-wall opening and the positioning plate is configured to engage the bend. This resists rotation of the positioning plate and therefore rotation of the housing about the stem. 
     The positioning plate may define at least one pocket adjacent a surface of the positioning plate and the another permanent magnet is in the at least one pocket. The control housing may include at least one pocket adjacent the control housing surface and the at least one permanent magnet is in the at least one pocket. The at least one permanent magnet and said another permanent magnet may each be a plurality of distributed bar magnets. The bar magnets may be made at least partially of cobalt. 
     The positioning feature may include a recess formed in said surface of the control housing with the recess sized to receive an extension from the side-channel. The extension from the side-channel may be a portion of a mounting bracket. The mounting bracket may support another control assembly. The another control assembly may be mounted at a surface of the side-channel that is opposite to the surface supporting the control housing. The conveying surface may be defined by belt-driven rollers and the another control assembly including a pneumatic actuator assembly that is adapted to selectively pressure the belt against some of the rollers. The mounting bracket may be supported in an opening in the side-channel and the extension is opposite the another control assembly. 
     The recess may be substantially a same shape as the extension. The recess may be substantially rectilinear. A grasping flange may defined in the control housing to facilitate separation of the control housing from the side-channel. 
     A conveyor system, control assembly used with the conveyor system, and method of assembling a control assembly to a side rail of the conveyor system, according to an aspect of the invention, includes a pair of spaced apart longitudinally extending side-channels, formed of a ferromagnetic material, and a conveying surface between the side-channels. A control assembly is supported by one of the side-channels. The control assembly has a control housing that houses at least one control component that performs a control function. A support mechanism supports the control housing with one of said side-channels. The support mechanism includes at least one permanent magnet mounted at a surface of the control housing that is adapted to attract the housing to a side-channel and a positioning feature. The positioning feature resists movement of the housing with respect to the side-channel in at least one degree of freedom. The positioning feature may be adapted to resist movement of said housing with respect to the side-channel in at least two degrees of freedom. 
     These and other objects, advantages and features of this invention will become apparent upon review of the following specification in conjunction with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side elevation view of a control assembly according to an embodiment of the invention mounted to a side-channel as viewed from the direction of the conveying surface; 
         FIG. 2  is a sectional view taken along the lines II-II in  FIG. 1 ; 
         FIG. 3  is a perspective view of the control assembly mounted to a side-channel taken in the same general direction as in  FIG. 1 ; 
         FIG. 4  is another perspective view of the control assembly mounted to a side-channel taken from the direction away from the conveying surface; 
         FIG. 5  is a perspective view taken generally from the front of the control assembly according to an embodiment of the invention; 
         FIG. 6  is an elevation view taken from the front of the control assembly in  FIG. 5 ; 
         FIG. 7  is a perspective view taken generally from the rear of the control assembly in  FIG. 5 ; 
         FIG. 8  is an exploded perspective view of the control assembly in  FIG. 5 , illustrating the support mechanism; 
         FIG. 9  is a perspective view of an alternative embodiment of an assembly mounted to a side-channel. 
         FIG. 10  is a side elevation view of the control assembly in  FIG. 9  mounted to the side-channel as viewed from the direction away from the conveying surface; 
         FIG. 11  is a sectional view taken along the lines XI-XI in  FIG. 10 ; 
         FIG. 12  is a perspective view of the control assembly in  FIG. 9  taken generally from the rear surface that faces the side-channel; 
         FIG. 13  is an elevation view of the control assembly in  FIG. 12  taken from the rear surface; 
         FIG. 14  is a top plan view of the control assembly in  FIG. 13 ; 
         FIG. 15  is an exploded perspective view of the control assembly in  FIG. 12  illustrating the support mechanism; and 
         FIG. 16  is a perspective view of a conveyor system used with the invention with one side-channel and the rollers defining the conveying surface removed to illustrate internal details thereof. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawings and the illustrative embodiments depicted therein, a conveyor system  20  includes a pair of spaced apart longitudinally extending side-channels  22 , only one of which is shown in  FIG. 16 , and a conveying surface  24  between said side-channels  22  defined by rollers (not shown) that are driven from below by a driven belt  64 . It should be understood that the invention can be embodied in other forms of conveying surfaces including, belt, segmented-belt-on-roller (SBOR), motorized rollers, and the like. Side rails  22  are formed of a ferromagnetic material such as steel, which is capable of attracting a permanent magnet. Conveyor system  20  includes a control assembly  26  supported by one side-channel  22 . Control assembly  26  has a control housing  28  that houses at least one control component  30  that is adapted to perform a control function. In the illustrated embodiment, control component  30  is a photo eye made up of a light-emitting laser diode, power supply, and logic circuitry for detecting an object being conveyed by conveying surface  24 . However, control component  30  may include an electronic logic controller, a pneumatic logic controller, or a combination of the two. Thus, the term control component is intended to be broadly interpreted to include any component used in a control function including laser reflectors, indicators, and the like. 
     Control assembly  26  further includes a support mechanism to support control housing  28  with one of side-channels  22 . The support mechanism includes at least one permanent magnet  34  mounted at a surface  35  of control housing  28  that is adapted to attract housing  28  to a side-channel  22  and a positioning feature  36  that is adapted to resist movement of control housing  28  with respect to the side-channel  22 . In the illustrated embodiment, permanent magnet  34  is made up of a plurality of individual bar magnets that are distributed across surface  35  within recesses  37 . Recesses  37  retain the bar magnets in place with little or no adhesive and separate the bar magnets from surface  35 . However, permanent magnet  34  could alternatively be one or more larger planar magnets as are known in the art. 
     Control assembly  26  has a stem  38  that extends from housing  28  through an opening  23  in the side-channel and a positioning plate  40  that has a cutout  42  that is configured to resist rotation of stem  38  with respect to plate  40  when stem  38  is in cutout  42 . This allows positioning plate  40  to establish rotational position of housing  28 . Also, opening  23  can be a conventional circular opening and does not need to be specially formed to fit stem  38 . Positioning plate  40  includes at least one other permanent magnet  44  mounted at a surface thereof, so that positioning plate is mounted to a surface of side-channel  22  that is opposite to the surface supporting the control housing. In this manner, permanent magnet  44  is adapted to attract plate to the side-channel  22  and does not create magnetic attraction between housing  28  and positioning plate  40 . In the illustrated embodiment, permanent magnet  44  is formed of a plurality of bar magnets that are fixedly retained in recesses  48  that are distributed about plate  40 , but could be other shapes as well. Positioning plate  40  is positioned at a bend  46  in side rail  22 . This restrains positioning plate  40  from rotating about an axis defined by stem  38 . Thus, with positioning plate  40  against bend  46 , control housing  28  is resisted from rotating about stem  38 , and is thereby adapted to resist movement of the housing with respect to the side-channel in at least one degrees of freedom. Also, positional plate  40  adds thickness to stem  38 . This resists rocking of control housing  28  along the length of stem  38  which is toward and away from conveying surface  24 . Thus, the support mechanism resists movement of the housing with respect to the side-channel in another degrees of freedom. 
     Thus, control assembly is firmly affixed to side rail  22 . This is accomplished without the need for fasteners, which would be difficult to thread onto stem  38  and rotate in the tight spaces within side-channel  22 . Also, since fasteners tend to be made of plastic, they can only be hand tightened or risk damage to the fastener or the stem. It should be understood that control and/or power wires leading to control component  30  can extend through an opening (not shown) in stem  38  and cutout  42 . In the illustrated embodiment, the bar magnets that define permanent magnets  34  and  44  are made at least partially of cobalt, or rare earth element, which are compact for the field they generate, but could be made of magnetized iron or other conventional material. 
     An alternative embodiment of a conveyor system  120  includes a control assembly  126  includes a housing  128  and interval control components that are not visible through housing  128  and at least one permanent magnet  134  that attracts housing  128  to side-channel  22 . Control assembly  126  further includes a positioning feature  136  that is adapted to resist movement of control housing  128  with respect to the side-channel  22  ( FIGS. 9 through 15 ). Positioning feature  136  is made up of a recess  152  formed in a surface of control housing  128  that faces side-channel  22 . Recess  152  sized to receive an extension  154  from side-channel  22 . Thus, positioning feature  136  is adapted to resist movement of housing with respect to the side-channel in at least one degree-of-freedom, namely against the force of gravity and a second degree of freedom, namely longitudinally along the side-channel. The permanent magnet attracts the housing against the side-channel. 
     Extension  154  is a portion of a mounting bracket  156 . Mounting bracket  156  supports another control assembly  158 . In the illustrated embodiment, another control assembly  158  and its mounting bracket  156  are mounted to a surface of side-channel  22  that is below conveying surface  24 , and therefore opposite to the surface supporting control housing  128 . In particular, extension  154  is one of two hook shaped portions of mounting bracket  156  that engage openings  60  in side-channel  22  to support mounting bracket  156 . Both extension  154  and recess  152  are substantially the same shape and are rectilinear. However, the shape of recess  152  is dictated by the shape of extension  154 . 
     Thus, control assembly  126  can be held in position against a vertical wall of side-channel  22  just by using existing features of conveyor system  120 . In this manner, no new holes need to be formed in the side channel and the control assembly  126  can be mounted by placing the housing  128  over existing extension  154  and allowing the permanent magnet  134  to attract the housing to the side-channel and the positioning feature  136  to resist downward or side-to-side motion of control assembly  126  with respect to the side-channel. Thus, a strong mounting is obtained without mechanical fasteners and without adding openings to the side-channel. This not only makes assembly easy but is also field assembly backward compatible with existing equipment. Grasping flanges  162  are shown on housing  128  in order to facilitate separation of control housing  128  from the side-channel by grasping the flanges. 
     In the illustrated embodiment another control assembly  158  is a pneumatic actuator assembly that is adapted to selectively pressure belt  64  against some of the rollers defining conveying surface  24 . Control assembly  126  is an electronic/pneumatic control that connects with an electronic network and provides pneumatic signals to operate another control assembly  158 . Control assembly  158  is disclosed in more detail in commonly assigned U.S. Pat. No. 6,478,142 entitled CONTACT ASSEMBLY FOR ACCUMULATION CONVEYORS, the disclosure of which is hereby incorporated herein by referenced in its entirety. 
     While the foregoing description describes several embodiments of the present invention, it will be understood by those skilled in the art that variations and modifications to these embodiments may be made without departing from the spirit and scope of the invention, as defined in the claims below. The present invention encompasses all combinations of various embodiments or aspects of the invention described herein. It is understood that any and all embodiments of the present invention may be taken in conjunction with any other embodiment to describe additional embodiments of the present invention. Furthermore, any elements of an embodiment may be combined with any and all other elements of any of the embodiments to describe additional embodiments.