Patent Publication Number: US-2022212824-A1

Title: Magnetic pouch clamp assembly and related methods

Description:
FIELD OF THE INVENTION 
     The present invention relates to pouching machines, and more particularly, to clamps for releasably holding the pouches through forming, filling and/or sealing operations. 
     BACKGROUND OF THE INVENTION 
     Most pouching machines employ pairs of track-mounted clamps which successively receive pouches and carry them to various stations where different operations are performed on the pouches, typically including filling and sealing and, depending on the type of pouching machine, initial forming operations. The clamps then release the filled and sealed pouches, which may be grouped and loaded in cartons or subject to further processing. 
     Most commonly, each clamp is held closed by spring pressure and, when receiving or releasing pouches, the clamp is urged open by application of an external mechanical force. While such clamps have been effectively used for many years, further improvements are possible. 
     SUMMARY OF THE INVENTION 
     In view of the foregoing, it is an object of the present invention to provide a magnetic pouch clamp assembly and related methods. According to an embodiment of the present invention, a magnetic pouch clamp assembly includes a first clamping arm, a second clamping arm and a magnet assembly. The first clamping arm has a first clamping surface, and the second clamping arm has a second clamping surface opposed to the first clamping surface. The second clamp arm is slidably connected to the first clamping arm such that the first and second clamping arms are movable between open and closed positions, with the first and second clamping surfaces being engaged in the closed position. The magnet assembly includes a first magnet having a first polarity carried by the first clamping arm and a second magnet having a second polarity carried by the second clamping arm, the first and second polarities being oriented such that a closing attractive force therebetween holds the first and second clamping surfaces in the closed position. 
     According to an aspect of the present invention, the magnet assembly includes a third magnet having a third polarity carried by the second clamping arm, the second and third magnets being located on opposite sides of the first magnet and the first and third polarities being oriented such that an opening attractive force therebetween holds the first and second clamping surfaces in the open position. 
     According to another aspect of the present invention, the first clamping arm defines a first guide slot and the second clamping arm defines a second guide slot, the first clamping arm includes a first magnet housing slidably received in the second guide slot and carrying the first magnet, and the second clamping arm includes a second magnet housing slidably received in the first guide slot and carrying the second magnet. 
     These and other objects, aspects and advantages of the present invention will be better appreciated in view of the drawings and following detailed description of preferred embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a magnetic pouch clamp assembly, according to an embodiment of the present invention; 
         FIG. 2  is another perspective view of the magnetic pouch clamp assembly of  FIG. 1 , with a guide slot cover removed to show internal details; 
         FIG. 3  is a partially exploded perspective view of the magnetic pouch clamp assembly of  FIG. 1 ; 
         FIGS. 4A and 4B  are sectional views taken along line  4 - 4  of  FIG. 1  with clamping surfaces in the open and closed positions, respectively; 
         FIG. 5  is a perspective view of a pair of magnetic pouch clamp assemblies mounted to carriages, according to another embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     According to an embodiment of the present invention, referring to  FIGS. 1-3 , a magnetic pouch clamp assembly  10  includes slidably connected clamping arms  12 ,  14  carrying a magnet assembly  16 . The magnet assembly  16  is operable to engage opposed clamping surfaces  20 ,  22  of the clamping arms  12 ,  14  in the open ( FIG. 4A ) and closed positions ( FIG. 4B ). 
     The clamping arm  12  includes a magnet housing  24  extending laterally therefrom through the clamping arm  14 . Magnet housing retention lugs  26  extend upwardly and downwardly from a distal end  30  of the housing  24 . Guide slots  32 ,  34  are defined in the clamping arm  12  extending across a width thereof. 
     Guide slot retention lug passages  36  are defined extending upwardly and downwardly from the guide slots  32 ,  34 . A guide slot cover  40  is attached to the clamping arm  12  over outer ends of the guide slots  32 ,  34 . Magnet housing blocking protrusions  42  extend into the guide slot retention lug passages  36  from an inner surface of the cover  40 . 
     The clamping arm  14  includes magnet housings  44 ,  46  extending laterally therefrom and slidably accommodated, respectively, in the guide slots  32 ,  34  of the first clamping arm  12 . The clamping arm  14  defines a guide slot  50  extending across a width thereof, which slidably receives the magnet housing  24  of the first clamping arm  12 . 
     Magnet housing retention lugs  26  extend upwardly and downwardly from the distal ends  52 ,  54  of the magnet housings  44 ,  46 . The guide slot  50  defines guide slot retention lug passages  36  extending downwardly and upwardly therefrom. A guide slot cover  56  is attached to the clamping arm  14  over outer ends of the guide slot  46  and includes a magnet housing blocking protrusion  42  extending inwardly therefrom into the passages  36 . 
     Each of the lugs  26  extend upwards or downwards beyond the height of respective guide slot  32 ,  34 ,  46 , which prevents lateral separation of the clamping arms  12 ,  14  by retaining the each magnet housing  26 ,  44 ,  46  within its respective guide slot  32 ,  34 ,  36 . The clamping arms  12 ,  14  are only separable by sliding them to align each lug  26  with a respective one of the passages  36 . Because the blocking protrusions  42  extend into the passages  36  with the guide slot covers  40 ,  56  in place, the covers  40 ,  56  must be removed prior to separating the arms  12 ,  14 —preventing inadvertent separation during normal opening and closing operations of the clamp assembly  10 . 
     The magnet assembly  16  includes magnets  60 ,  62 ,  64 , each located in a respective one of the magnet housings  24 ,  44 ,  46 . The magnets  60 ,  62 ,  64  are preferably rare earth magnets, such as neodymium or samarium-cobalt magnets, although electromagnets could be used within the scope of the present invention. 
     The polarities +/− (see  FIGS. 4A, 4B ) of the magnets  60 ,  62  are oriented such that an attractive force therebetween holds the clamping surfaces  20 ,  22  in the closed position. The polarity +/− of the magnet  64  is preferably oriented relative to that of the magnet  60  such that an attractive force therebetween holds the clamping surfaces  20 ,  22  in the open position, and more particularly, a fully open position. 
     This is advantageous in that application of force is required only to transition the clamping surfaces  20 ,  22  between the open and closed position, and not to maintain the surfaces  20 ,  22  in either position. Alternately, the polarity (+)/(−) of the magnet  64  is oriented relative to that of the magnet  60  such that a repulsive force therebetween urges the clamping surfaces  20 ,  22  toward the closed position, reducing the energy required for this transition. 
     Advantageously, each magnet  60 ,  62 ,  64  is situated in its respective magnet housing  24 ,  44 ,  46  with a plurality of shims  66 . The spacing between the magnets  60 ,  62  and between the magnets  60 ,  64  can be adjusted by moving some or all of the shims  66  in a magnet housing  24 ,  44 ,  46  to the other side of the magnet  60 ,  62 ,  64 . The guide slot covers  40 ,  50  help ensure that the magnets  60 ,  62 ,  64  and shims  66  remain in their respective housings  24 ,  44 ,  46 . 
     The use of three magnets in each magnet assembly is preferred because it minimizes the number of magnets while still allowing the clamp assembly to be held by magnetic attraction in both the closed and open positions. It will be appreciated that two or more pairs of magnets could be used to the same effect simply by modifying the clamping arms to include a corresponding number of additional magnet housings and guide slots. Likewise, the present invention could be used with only a single pair of magnets, such that magnet attraction only holds the clamp assembly to be held closed (or open). 
     In operation, the clamping arm  14  is mounted to a carriage via the mounting holes  70 , with the clamping arm  12  slidably mounted thereto. An engagement roller  72  extending from the clamping arm  12  is engaged by an external mechanism to transition the magnetic clamp assembly  10  between open and closed positions. 
     Pouch retention when closed is enhanced by knurled or otherwise textured finishes on opposing faces of the clamping surfaces  20 ,  22 . Since the clamping arms  12 ,  14  are laterally adjacent, a lateral extension  74  at the distal end  76  of the clamping arm  14  to allow the clamping surface  22  to be located coaxially along a clamping axis opposed to the clamping surface  20 . A lateral extension  82  at the distal end  84  of the clamping arm  12  is angled away from the clamping surface  20  and facilitates pouch loading. 
     The abutting inner sides of the clamping arms  12 ,  14  preferably completely cover the inner openings of the guide slots  32 ,  34 ,  50  while the outer openings of the guide slots  32 ,  34 ,  50  are completely covered by the covers  40 ,  56 . This arrangement advantageously inhibits fine particulates commonly encountered during pouching operations from entering the guide slots  32 ,  34 ,  50  and interfering with the opening and closing of the clamp assembly  10 . 
     Referring to  FIG. 5 , according to another embodiment of the present invention, a pair of magnetic pouch clamp assemblies  10 A,  10 B are each mounted on adjacent carriages  90 A,  90 B. The clamp assemblies  10 A,  10 B are mirror-images of one another, such that lateral extensions  74 A/B,  82 A/B on the distal ends  76 A/B,  84 A/B of the clamping arms  12 A/B,  14 A/B extend toward one another, allowing both side of a pouch to accommodated therebetween. 
     It will be noted that, in the clamp assemblies  10 A,  10 B, the outboard clamping arms  14 A,  14 B carry the engagement rollers  72 A,  72 B while the inboard clamping arms  12 A,  12 B are mounted to the carriages  90 A,  90 B. A roller engagement mechanism  92  is positioned to engage the rollers  72 A,  72 B to simultaneously urge both the clamp assemblies  10 A,  10 B into the open position. 
     To help counteract the force exerted on the clamp assemblies  10 A,  10 B and carriages  90 A,  90 B, retentions mechanisms  94 A,  94 B (such as the depicted hooks) are located on proximal ends  96 A,  96 B of the mounted clamping arms  12 A,  12 B. These mechanisms  94 A,  94 B are able to engage a rail or other fixed structure at opening positions for the assemblies  10 A,  10 B, thereby preventing unwanted movement thereof. 
     The above-described embodiments are provided for illustrative purposes; the present invention is not necessarily limited thereto. Rather, those skilled in the art will appreciate that various modifications, as well as adaptations to particular circumstances, will fall within the scope of the invention herein shown and described, and of the claims appended hereto.