Abstract:
A method and apparatus of unloading a battery group from a jig box including engaging the bottom of group on a support, releasing the grip of the jig box on the group, raising the support and gripping the raised group.

Description:
This application is a division of application Ser. No. 09/180,579 filed on Nov. 12, 1998 now U.S. Pat. No. 6,324,751, which is a 371 of PCT/GB97/01176 filed on May 12, 1997. Application Ser. No. 09/180,579 is the national phase of PCT International Application No. PCT/GB97/01176 filed on May 1, 1997 under 35 U.S.C. §371. The entire contents of each of the above-identified applications are hereby incorporated by reference. 
     CROSS REFERENCE TO RELATED APPLICATION 
     This is the 35 USC 371 national stage of International application PCT/GB97/01176 filed on May 1, 1997, which designated the United States of America. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to apparatus for loading battery plate groups into a battery box and, in particular, but not exclusively to loading groups for recombination batteries. 
     BACKGROUND OF THE INVENTION 
     Recombination batteries (i.e. batteries in which the hydrogen and oxygen recombine to form water) tend to have separators of mircroporous glass fibre in which the acid electrolyte is fully absorbed. The separator material is extremely delicate and the group has to be loaded into the battery box in a compressed state (and retained in that state by the box) in order to ensure that the electrolyte is in active contact with the plates. 
     It will readily be appreciated that there are significant difficulties in inserting the compressed group into the battery box cell when that cell is substantially the same size without damaging the separators. 
     There are also problems in transferring such groups from the processing jig boxes, because the walls in the jig boxes which apply the compression can mark the separators if they do not act over the full separator surface. Accordingly attempts have been made to load the groups directly from the jig box by providing guides on the ends of the jig box walls. However, these guides can only extend partially across the width of the battery cell, because space must be allowed for the transverse supports on which the group elements sit when the jig box is being loaded. The result is that the unguided portions of the groups snag on the box wall. 
     SUMMARY OF THE INVENTION 
     From one aspect the invention consists in a frame for use in loading groups of battery plates into respective cells in a box, comprising a plurality of spaced walls defining respective group receiving spaces, the walls being moveable away from and towards each other to allow groups to be inserted in the spaces and subsequently grippingly retained therein by the walls, and guide means mounted at the lower end of the walls to locate in the cells and form a continuous surface with the walls characterised in that guide means extend across the full width of the walls, cells or groups. 
     It is particulary preferred that the frame further comprises stop means for each space insertable between a respective pair of walls into the respective space to locate the bottom edge of a group when it is placed into the space. 
     From another aspect the invention consists in a frame for use in loading groups of battery plates into respective cells in a box, comprising a plurality of spaced walls defining respective group receiving spaces, the walls being moveable away from and towards each other to allow groups to be inserted into the spaces and subsequently grippingly retained therein by the walls characterised in that it further comprises stop means for each space insertable between a respective pair of walls into the respective space to locate the bottom edge of a group when it is placed into the space. 
     Conveniently, in either case, the stop means locates the group against downward movement and lateral movement relative to the mid-plane of the group. In any of these cases, the stop means should be removable from the spaces. Thus, for example, the stop means may provide orthogonal abutments and may be rotatable about an axis adjacent to the intersection of the abutments so that the stop means can be rotated into and out of the space. The stop means may also be moveable with or in relation to the walls to maintain their relative location vis-à-vis the walls. 
     The distance between the group bottom edge location defined by the stop means and the top of its associated walls in preferably greater than the total height of the groups. This prevents any part of the group becoming snagged on the edges of the walls during insertion from the frame. 
     From yet another aspect the invention consists in battery group loading apparatus including a frame as defined above and further comprising means for loading groups into respective spaces in the frame to sit on the respective stop means, means for moving the walls towards each other to grip the groups between the walls, means for removing the stop means from the spaces, means for engaging a battery box with the guide means and means for pushing the groups through the guide means into the box. 
     Preferably the means for moving the walls towards each other are designed to exert compressive forces on the groups, in which case this force can be maintained during the operation of the pushing means. 
     The pushing means may act simultaneously on all the groups and may have heads, each of which may be formed with formations to cooperate with the terminal posts or straps cast on the groups so as to achieve precise location between the head and the group. 
     From another aspect the invention includes apparatus for unloading a battery group from a jig box including support means for engaging the bottom of a group on a support, whilst the group is held in a jig box, means for releasing the groups within the jig box, means for raising the support to a level at which a substantial portion of a supported group would stand clear of the jig box and means for gripping the raised group. The support may include lateral abutments for preventing sideways movements of the group during raising. 
     From a further aspect the invention consists in apparatus for unloading groups with cast on straps from a jig box and for loading those groups into a battery box comprising the apparatus for unloading as defined above and the battery group loading apparatus as defined above. 
     From a still further aspect the invention consists in a method of unloading a battery group from a jig box including engaging the bottom of a group on a support, releasing the grip of the jig box on the group, raising the support and hence the group until a substantial portion of the group is clear of the jig box and gripping the raised group. 
     The advantage of this method and the associated apparatus defined above, is that, in contrast to existing gripping arrangements (where the groups are gripped through openings in the jig box, whilst the groups are still in the box) is that both the jig box and the gripping means may be provided with gripping surfaces which are continuous over the whole portion which engages the group. This prevents damage and marking of the outside separators. 
     Although the invention has been defined above, it is to be understood that it includes any inventive combination of the features set out above or in the following description. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     The invention may be performed in various ways and a specific embodiment will now be described, by way of example, with the reference to the accompanying drawings, in which: 
     FIG. 1 is a view from above of a recombination battery with its lid removed; 
     FIG. 2 is a vertical section through an end cell of FIG. 1 showing the group in situ; 
     FIG. 3 is a part schematic view of an unloading station of a machine for casting straps on battery groups; 
     FIG. 4 is a diagrammatic representation of the removal of groups from the jig box of the machine of FIG. 3; 
     FIG. 5 is a diagrammatic representation of a loading configuration and illustrates in descending order a gripper holding groups, a compression frame and a battery box on a conveyor; 
     FIG. 6 is a view from above on the compression frame of FIG. 5; 
     FIG. 7 is a schematic partial side view of part of the frame of FIG. 6; and 
     FIG. 8 is a edge view of a stuffing tool for pushing the groups from the frame of FIG. 7 into a battery box. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As has been mentioned previously recombination batteries require that the battery groups of plates and separators are inserted into the cells of a battery box under compression and that that compression is maintained by the walls of the battery box cells. 
     FIG. 1 illustrates a battery box  10  have cells  11  in which groups  12  have been inserted. The groups  12  comprise interleaved separators  13  and plates  14 . The plates  14  have lugs  15  onto which straps  16  or terminal posts  17  have been cast by a machine for casting on such straps. 
     Whilst such machines can take a number of forms, they now typically comprise a rotatable table which can support jig boxes in a series of circumferentially spaced locations. Each jig box comprises a number of spaces or cells into which groups can be loaded at a loading station and the jig boxes have walls which can be moved towards and away from each other to group and release the groups. As the table indexed around the groups pass through stations in which they are aligned, the lugs cleaned and fluxed, and have straps and terminal posts cast on them so that by the time a jig box arrives at an unloading station it contains, in the correct order and alignment, a set of groups  12  ready for loading into a battery box. The Applicants sell examples of such machines under the Trade Marks COS5 and COS8. 
     Such an unloading station is illustrated in FIG. 3 and is generally indicated  18 . However the unloading station  18  has a number of new an inventive features. A jig box  19  is illustrated at the station and it can be seen that it defines a plurality of side-by-side spaces  20  in which the groups are contained. (The groups are not shown in FIG.  3 ). When the jig box  19  arrives at the unloading station  18  the groups  12  are gripped within the spaces  20 . Contrary to traditional jig boxes designed for automatic unloading, the walls  21  of the jig box  19  are continuous and extend over almost the full area of the engaged faces on the groups  12 . This means that it is not possible to remove the groups from the jig box by the traditional method of passing gripping fingers through gaps in the wall to engage the groups. The Applicant has overcome this problem by providing a series of supports  22  which are initially raised to the position shown in FIG. 3 at which they engage the lower most edge of the groups  12 , as indicated by the broken line  23 . (The supports  22  may have upstanding ends (not shown) to restrict lateral movement of the groups  12 .) 
     Once the groups  12  are engaged by the supports  22 , the walls  21  can be moved marginally away from each other to release the groups, whereupon further upward movement of the supports  22  allows the groups  12  to be pushed up through the spaces  20  so that they stand substantially proud of the jig box  18  as illustrated at  24  in FIG.  4 . In this position the groups  12  are engaged by plates  25  of gripper heads  26  and they can then be raised out of the jig boxes as illustrated at  27  in FIG.  4 . 
     The removed groups  12  can then be transported laterally by the heads  26  until they overlie a compression frame, which is generally indicated at  28 , as can be seen in FIG.  5 . The compression frame  28  is more fully illustrated in FIGS. 6 and 7 and includes two end pieces  29 ,  30 , which are interconnected, at each side, by pairs of vertically spaced horizontal rods  31 - 34 . Walls  35  are slidably mounted on the upper rods  31 - 32 , whilst stops  36  are rotatably and slidably mounted on the lower rods  33 - 34 ; there being a pair of opposed stops  36  for each group space  37  defined between a pair a of adjacent walls  35 . The walls  35  and stops  36  are interlinked by respective chains  38 , 39  so that when an end stop and wall combination  40  is pulled away from its adjacent wall, the other walls and stops are pulled apart equally to spacing defined by the lengths of the chains. This movement is obtained by cylinder  60 , which can also move in the opposite direction to compress the walls  35  together to spacings defined by spacers  41 . These two positions constitute the open and closed positions of the frame  28 . 
     As can be seen in FIG. 5 each stop  36  comprises a generally rectangular body  42 , which is slidably and rotatably mounted on a respective rod  33 , 34 , and a projecting foot  43  for supporting the bottom of a group  12 . The inward ends  44  of the bodies  42  define lateral abutments for the groups  12  so that they cannot move in a sideways direction. The bodies  42  on each side are interlinked as a set by respective rods  45 , which can be used to rotate the stops  36  from their support position, which is shown in FIG. 5 to a generally vertical position in which they completely disengage the groups  12 . 
     Each wall  35  carries one or more guide shims, which are designed to project into associated cells  11  of the battery box so that they define a guide surface for the groups to be slid along as they move into the respective cells  11 . The shims  46  are formed continuously with their associated walls  35  so that there are no edges or projections which can damage the groups. Preferably the walls  35  and their shims  46  are formed from a single piece of highly polished flexible metal. The height of the walls from the location defined by the feet  43  is greater than the height of the groups, so that, once inserted, the groups cannot catch on any part of the wall and the width of the walls is greater than the width of the groups. 
     At the lower end of the frame  28  is mounted a rectangular guide frame  47 , which receives and locates the frame  28  relative to a battery box  10  carried on a conveyor  49 . The guide frame  47  has a tapered open mouth  49  so that the box  10  is not damaged, when the frame  47  is engaged on it and equally the groups do not snag on the box  10  during insertion. 
     Returning to FIG. 5, the groups  12  held in the gripping heads  26  are loaded into respective spaces between pair of walls  35 , when the walls are in their “open” position. In this position the stops are arranged as shown in FIG.  5  and so the groups are supported within their respective spaces by pairs of feet  43  and are laterally located by ends  44 . The walls  35  are then drawn together by cylinder  60  until they both grip and compress the groups  12 . (Adjustable stops  40   a  define the limit of compression and may be provided in addition to or instead of stops  41 . Their advantage is that they allow easy adjustment for different battery size. Stops  41  are in any case used for ‘dry’ running the machine.) The frame  28  is then lowered downwardly onto a battery box  10  which has been brought to the correct position by a conveyor  50  and the exact relative position between the battery box  10  and the frame  28  is defined by the guide frame  47 . At this time the stops  36  can be swung out so that the groups can then be pushed downwardly, whilst still under compression into the cells  11 . Because the walls  35  and shims  46  provide a continuous surface this is achieved simply, swiftly and without damage. 
     This pushing steps is achieved by a pusher (or stuffer) which is generally indicated at  51  in FIG.  8 . The pusher comprises a number of laterally spaced vertically dependent rods  52  each of which carries a head  53  at its free end. The upper ends of the rods  52  are located on a plate  54 , which can be raised and lowered by a cylinder  55 . The heads  53  are profiled so that they precisely receive the upper surface of the group, the exact shape being determined by whether the engaged group includes end terminals or simply straps. This profiling not only protects the group, but ensures very precise alignment between the heads  53  and the groups  12 . Once the heads  53  have been engaged on the tops of the groups  12 , the cylinder  55  moves the pusher  51  downwards and the groups are pushed straight into the cells  11 . 
     It will be understood that the whole arrangement of the frame  28  and the pusher  51  enables very precise relative location of the pusher  51 , the groups  12  and the battery box  10  and so the insertion happens extremely smoothly, despite the very tight fit which is necessary in a recombination battery. 
     Although the invention has been described very much in the context of recombination batteries, the ability to load a series of adjacent cells simultaneously, is also attractive in the manufacture of other types of battery and the general principles outlined in the above specification may be equally applicable. 
     The precise construction shown in the drawings is advantageous, but the invention incorporates many variations. For example the stops could be slid in and out of the spaces, in which case a pair of stops could be constituted by a single element. Equally a single stop element might be swung up from one side.