AU3847101A - Low profile six-volt lead-acid battery with front terminals - Google Patents

Description

WO 01/61771 PCT/USO1/05200 LOW PROFILE SIX-VOLT LEAD-ACID BATTERY WITH FRONT TERMINALS FIELD OF THE INVENTION This invention relates to six-volt lead-acid batteries and, more particularly, to 5 a low profile six-volt lead-acid battery having front terminals. BACKGROUND OF THE INVENTION Lead-acid batteries have long been in use for a wide variety of applications. For example, such cells and batteries have been used for what have sometimes been 10 termed "stationary" battery applications wherein the lead-acid batteries provide stand by power in the event of a power failure. For this type of application, such stationary batteries are maintained at a full-state-of-charge and in a ready-to-use condition, typically by float maintenance charging at a constant preset voltage. By way of illustration, such stationary batteries may be used in telecommunications, utilities and 15 the like. In many applications, the space allotted for the battery is limited, yet there is a need for batteries having increased electrical capacity. For example, in some stationary applications, the batteries are placed upon racks. Utilizing batteries having top terminals requires more battery space since clearance must be provided above the 20 batteries so the installer can reach in above the batteries and make the appropriate electrical connections. Utilizing shelves that slide out may reduce some of the clearance required, but add additional cost for the rack structure required. Further, as is known, current lead-acid battery designs create restrictions on the height of the grids utilized. Thus, in general, and as is known, the grid height that 25 may be utilized is limited by the requirements involved in sealing (typically, heat sealing) of the cover to the battery container and in providing appropriate internal electrical connections. Thus, there is a need for a lead-acid battery having terminals located such that they can be accessed from the front of a battery rack or the like. Further, there is a 30 need for such lead-acid batteries having enhanced electrical performance without requiring undesirably tall batteries, i.e., a low profile battery. Such batteries, however, must be capable of being assembled to provide a reliable battery without WO 01/61771 PCT/US01/05200 2 requiring undue modification of conventionally used lead-acid battery assembly processes and equipment. Accordingly, it is a primary object of the invention to provide a battery that may be efficiently utilized when placed in a battery rack without requiring the use of 5 sliding shelves or excessive clearance above the battery. A related object of this invention is to provide a six-volt lead-acid battery having front terminals so as to facilitate access when such batteries are located in use in battery racks or the like. It is another object of the present invention to provide a low profile battery having enhanced electrical performance. 10 A still further object lies in the provision of such low profile, front terminal batteries which are capable of being fabricated using existing lead-acid battery assembly techniques. Other objects and advantages of the present invention can be seen from the following description of the invention. 15 BRIEF SUMMARY OF THE INVENTION The invention provides a low profile, 6-volt battery having both positive and negative terminals disposed along the front of the battery, that is, having both terminals disposed along the front cell such that connections may be readily made to 20 the terminals when the battery is disposed on a shelf The battery container is divided by partitions into three cells disposed in a 1 by 3 arrangement with front, middle, and rear cells which each contain alternating positive and negative plates separated by separators. The lugs of the positive plates and the lugs of the negative plates are electrically connected by positive and negative straps, respectively, the straps of 25 adjacent cells being electrically coupled by conventional means by through the partition welds or the like. In accordance with the invention, the elements of the front cell are electrically coupled to a front terminal along the front of the battery via a front cell terminal bushing, while the elements of the rear cell are electrically connected to the front of 30 the battery, i.e., adjacent the front cell, by a connector bar. The lugs of the rear cell which are not coupled to the middle cell are electrically connected by a strap to an upstanding post. The connector bar then couples the post to a front cell terminal WO 01/61771 PCT/USO1/05200 3 bushing which presents the terminal along the front of the battery. The connection to the post may be direct, or, alternately, a strap bushing may be welded to the post and the connector bar coupled to the strap bushing. The terminals may be disposed along the front wall, along the top of the 5 battery substantially adjacent the front wall, along the sides of the battery substantially adjacent the front wall, or as dual terminals substantially adjacent the front wall, i.e., as a combination of top terminals with side or front terminals. In this way the user may readily access the terminals even when the battery is disposed on a shelf which does not permit the user to reach in between. 10 Additionally, the battery may be readily constructed according to methods known in the art. The invention provides a high quality, durable battery which may be economically and efficiently manufactured. BRIEF DESCRIPTION OF THE DRAWINGS 15 FIGURE 1 is a perspective view of a preferred embodiment of a six-volt battery according to teachings of the present invention. FIG. 2 is a top view of a container used in the battery of the present invention. FIG. 3 is a cross-sectional view taken generally along line 3-3 of FIG. 2. FIG. 4 is a cross-sectional view taken generally along line 4-4 of FIG. 2. 20 FIG. 5 is a plan view of an intermediate cover used in the battery of FIG. 1. FIG. 6 is a cross-sectional view of the intermediate cover taken along line 6-6 in FIG. 5 and illustrating one of the front cell terminals. FIG. 7 is another cross-sectional view of the intermediate cover taken along line 7-7 of FIG. 5 and showing the rear connection bushing and the other front cell 25 terminal. FIG. 8 is a bottom view of the intermediate cover of FIG. 5 and illustrating the respective positioning of the alignment guides for accommodation of a six-volt battery as well as a twelve-volt battery. FIG. 9 is a plan view of a final cover of a battery such as illustrated in FIG. 1. 30 FIG. 10 is a bottom view of the final cover of FIG. 9. FIG. 11 is an enlarged fragmentary view of the post and rear connector bushing of FIG. 12.

WO 01/61771 PCT/USO1/05200 4 FIG. 12 is a top assembly view of the container and intermediate cover of FIG. 1 showing the cell elements, the intercell welds, and the connector. FIG. 13 is a cross-sectional view of the assembly taken generally along line 13-13 of FIG. 12 and illustrating the internal electrical connections. 5 FIG. 14 is an end view of the assembly of FIG. 12 taken generally along line 14-14 in FIG. 12. FIG. 15 is a connector arm of a first embodiment of the six-volt battery of FIG. 1. FIG. 16 is a cross-sectional view of the connector taken along line 16-16 in 10 FIG. 15. FIG. 17 is a cross-sectional view of the connector taken along line 17-17 in FIG. 15. FIG. 18 is a top assembly view of the battery assembly illustrating an alternate embodiment of the connector bar and the connection of the connector bar to the 15 internal components. FIG. 19 is a top assembly view of the battery assembly illustrating a third embodiment of the connector bar and the connection of the connector bar to the internal components. FIG. 20 is an enlarged fragmentary view of the post and connector bar of 20 FIGS. 18 and 19. DESCRIPTION OF THE PREFERRED EMBODIMENTS As is shown in FIGURE 1, the lead-acid battery 10 comprises a container 12 having side walls 14, a front wall 16, and a back wall 18. The composite cover shown 25 generally at 20 comprises an intermediate cover shown generally at 22 sealed or otherwise attached to container 12, and a final cover 24 sealed to intermediate cover 22. The battery 10, according to the preferred embodiment, includes a flame arrestor shown at 26, and positive and negative terminals 28, 30. The container 12, as best seen in FIGS. 2-4, includes cross-partitions 34 30 dividing the container into three cells in a lx3 cell configuration, with a front cell 38, a central cell 40, and a back cell 42. The terminal cells are thus defined by the interior surface of the side walls 14 (see FIG. 4), the front and rear walls 16, 18 and by the WO 01/61771 PCT/US01/05200 5 surfaces of the cross-partitions 34. Although six-volt battery configuration is illustrated, the size of the cells can be varied as desired to satisfy the space and electrical performance requirements of the particular application. An optional feature includes structure allowing the battery to be lifted, 5 whether by hand or other means. As is shown in FIG. 3, container 12 is provided with holes 46 located on front wall 16 and back wall 18 so as to accommodate a rope or other handle (not shown). The illustrative embodiment utilizes a two-piece cover 20, that is, a cover which includes an intermediate cover 22 and a final cover 24. As shown in FIGS. 5 10 8, the intermediate cover 22 is configured complementally with container 12 so as to allow the use of conventional heat sealing equipment to seal these components together. In the preferred embodiment illustrated, the intermediate cover may likewise be utilized in a 12-volt battery configuration having a 2x3 cell arrangement as opposed to the lx3 cell arrangement illustrated in FIGS. 2-4. Accordingly, the 15 intermediate cover 22 includes a base structure shown generally at 50 divided by intermediate cover center partitions 52 (see FIG. 8) configured to align with center partitions of a 12-volt container (not illustrated). Access to the front cell 38 is provided by fill holes 54, while fill holes 56 and 58 provide access to central cell 40 and back cell 42, respectively. 20 Optionally, and desirably, intermediate cover 22 likewise includes guide pins 70 (FIG. 8), preferably positioned both adjacent intermediate cover walls 68 and the location of a central partition in a 12-volt battery so as to facilitate assembly. Any desired configuration of guide pins 70 can be used. Additionally, the preferred embodiment of the intermediate cover 22 is 25 designed to provide common head space for the cells 38, 40, 42 and also to allow for pressure testing to ensure that appropriate sealing has been provided. As can be seen from FIGS. 5, 7 and 8, common head space is provided via fill holes 54, 56, 58 and upstanding structure 78. Inasmuch as the battery operates under pressure, the intermediate cover 22 30 also comprises valves 76, as may be seen in FIGS. 5, 7, and 8. In operation, the valves 76 operate to release pressure when a given pressure is exceeded within the battery 20.

WO 01/61771 PCTIUS01/05200 6 FIGS. 9-10 illustrate a preferred embodiment for the final cover 24. This cover piece comprises a final cover base 82 complementally shaped so as to fit upon intermediate cover 22. Final cover 24 accordingly includes a front sealing surface 84, a rear cell sealing surface 86 and side surfaces 88 all complementally sized with 5 respect to intermediate cover 22. Final cover 24 likewise includes structure compatibly shaped and positioned with regard to fill holes 54, 56, 58 and structure 78 of intermediate cover 22 so as to allow for the common head space. Appropriate venting into such common head space can be achieved through venting techniques known in the art. A flame arrestor 26 may likewise be included in the final cover 24. 10 Turning back to the intermediate cover 22 and referring now to FIGS. 12 and 13, a battery is illustrated having the intermediate cover 22 and the cell components in place. Each of the three cells 38, 40, 42 contains a battery element comprising a series of alternately disposed positive plates (not visible) and negative plates 100 having separators 102 positioned therebetween, as is known in the art (the battery 15 element is illustrated only schematically in FIG. 12 to eliminate excess lines). As shown in FIG. 13, the negative plates 100 include upwardly extending lugs 104 which are electrically connected together in each cell by a negative strap 106, 108. The positive plates of each cell similarly include lugs 110 which are electrically connected together in each cell by a positive strap 112, 114. The positive and negative straps 20 112, 108 of adjacent cells may be electrically connected by conventional intercell connections. As shown in FIGS. 12 and 13, intercell welds 116 connect the positive and negative straps 112, 108 of adjacent cells 38 and 40, 40 and 42 via conventional tombstones 118. The particular configuration and the number of plates and their respective size 25 can be varied as desired for a particular application. Moreover, the present invention can be used whether the lead-acid battery is of the flooded electrolyte type or sealed type (i.e., a VRLA or valve-regulated lead-acid). Suitable grids and alloys are known and may be utilized, as are appropriate separator materials. The intermediate cover 22 also houses the terminals 28, 30 and contains 30 structure allowing appropriate electrical connection to such terminals. As may be seen most clearly in FIGS. 6 and 12, a negative terminal bushing 120 having an opening 122 is provided. The negative strap 76 of the front cell 38 is connected to an WO 01/61771 PCT/US01/05200 7 upstanding post 124, which is received in the opening 122 in order to present a terminal 30 for connection. The bushing 120 and post 124 are coupled by any appropriate method known in the art, e.g., welding, to provide an electrical connection to the negative terminal 30. In order to facilitate formation of the battery 12, the 5 bushing 120 further includes a formation adapter 126 to which a lead (not shown) may be coupled during formation. It would be appreciated by those of skill in the art that a 1x3 cell arrangement, such as illustrated in the figures, would typically yield a terminal of a first polarity at one end of the container adjacent one cell, and a terminal of a second polarity at the 10 opposite end of the container adjacent a cell disposed at the opposite end. This is due to the structural arrangement whereby a strap 106 of one polarity (in this case, a neGative strap) is disposed adjacent one end of the battery 10 adjacent the front cell 38, while a strap 114 of the opposite polarity (in this case, a positive strap) is disposed at the opposite end of the battery 10 adjacent the back cell 42. 15 In accordance with the invention, however, the positive and negative terminals may both be disposed along the same end of the battery 10 adjacent a single cell, in this case the front cell 38. In this fashion, when placed upon a battery rack or the like, the positive and negative terminals 28 and 30 can be readily accessed, as is needed in service. In order to permit both terminals 28, 30 to be disposed adjacent a single cell, 20 in this case, the front cell 38, the strap 106 of the front cell 38 is connected to a terminal 30 along the front cell 38 of the battery, while a connector or metallic bar 130 is provided which electrically connects the strap 114 adjacent the back cell 42 to a terminal 28 substantially adjacent the front cell 38. While the respective arrangement of the terminals 20, 30 will be described with respect to the negative 25 strap 106 of the front cell 38 being connected directly to the front cell negative terminal 30, and the positive strap 114 of the back cell 42 being coupled to the front cell positive terminal 28 by way of the connector bar 130, the arrangement might be reversed such that a front positive strap is connected directly to a front cell terminal and a rear cell negative strap is coupled to the front of the battery by an elongated 30 connector bar. In accomplishing this objective, the positive strap 114 of the rear cell 42 comprises an upstanding post 132, similar to the negative post 124 of the front cell 38.

WO 01/61771 PCT/US01/05200 8 The post 132 is received in an opening 134 in a positive strap bushing 136 or connector bushing as shown in FIGS. 11 and 13. As with the negative terminal bushing 120, the positive strap bushing 136 includes a formation adapter 138 to which a lead (not shown) may be coupled during battery formation. In contrast to the 5 negative terminal bushing 120, however, the positive strap bushing 136 does not include the positive terminal 28. In order to present a positive terminal 28 for connection, a positive terminal bushing 140 is likewise provided along the front cell 38. The positive terminal bushing 140 includes the positive terminal 28 which is presented at the front of the battery 12. 10 In order to couple the positive strap bushing 136 to the positive terminal bushing 140, the bushings 136, 140 are each provided with upstanding coupling structures 138, 142 in the form of hollow posts. The connector bar 130 comprises openings 144, 146 at either end which may receive the posts 138, 142 to electrically connect the positive strap bushing 136 to the positive terminal bushing 140. The 15 connector bar 130 may be coupled to the posts 138, 142 by conventional methods, such as welding In this way, the rear cell 42 is directly connected to the front terminal 28 such that both the positive and negative terminals 28, 30 are accessible from the front of the battery. As a result, when such batteries 12 are stored in a rack (not shown), the terminals 28, 30 may be easily accessed without necessitating that the 20 shelves of the rack be movable even if the shelves are closely spaced. It will be appreciated that the upstanding coupling structure 138 of the positive strap bushing 136 may likewise be utilized for the placement of a lead, or as a formation adapter, during formation of the battery 12. Utilization of the formation adapter 126 of the negative terminal bushing 120 and coupling structure 138 of the 25 positive strap bushing 136 for attachment of the leads allows the manufacturer to put the acid into the cells 38, 40, 42 and clean the battery 12 prior to assembly of the connector bar 130 and welding it in place. The connector bar 130 is preferably formed of copper to provide minimal resistance. In the preferred embodiment illustrated in FIGS. 9 and 10, an elongate 30 copper rod 150 is at least partially embedded in lead 152, and is offset from attachment points or openings 144, 146 at either end. It will be appreciated that the battery 12 may be formed and cleaned as described above prior to assembling the WO 01/61771 PCT/US01/05200 9 connector bar 130 to the battery, minimizing the opportunity for interaction between the acid and the copper of the bar 130. Further, in order to protect the bar 130, a final cover 80 may be heat sealed to the intermediate cover 28, or a second cover (not shown) may be heat sealed to cover the compartment in the intermediate cover 22 5 containing the bar 130. It will further be appreciated that the connector bar 130 may be alternately laid out and/or coupled between the strap 114 of the rear cell 42 and the terminal 28 of the front cell 38. By way of example only, the connector bar 160 may be straight, as illustrated in FIG. 18, rather than offset. Further, the bar 160 may be directly 10 connected to the positive strap post 168, as likewise illustrated in FIG. 18, as well as the embodiment illustrated in FIG. 19, FIG. 19 comprising a bar 170 which is offset as connected to the positive terminal bushing. In the embodiments shown in FIGS. 18 and 19, a bushing 172 is molded into the intermediate cover 174 as shown in FIG. 20. An appropriate weld or the like is then made to electrically connect the post 168 to the 15 bushing 172, and the bushing 172 to the connector bar 160, 170. Alternately, the connector bar may be molded into the intermediate cover itself. It should be appreciated that the particular configuration of the terminals themselves can be varied as needed for the service requirements of the particular application. Internally threaded configurations, as are illustrated, are often employed 20 in stationary applications where several batteries need to be electrically connected together. Further, while the embodiment shown has front terminals located adjacent the front wall 16 of the battery, it should be appreciated that top terminals, either alone or as dual terminals with the front terminals as illustrated might alternately be provided. Indeed, if desired, the terminals, either alone or as a dual terminal 25 configuration, could be located as side terminals adjacent the front of side walls 14. In any event, the terminals employed are located at least near the front wall 16 so as to allow ready access in service. It will likewise be appreciated that the connector bar arrangement would be equally applicable to any cell arrangement comprising an odd number of cell rows 30 extending rearward from the front wall of the battery. For example, the connector bar could be utilized in a 3x3 or 3x5 arrangement.

WO 01/61771 PCT/USO1/05200 10 Further, the manner and structure which is utilized to make the electrical connections can vary as desired, consistent with the objectives of this invention. Thus, what is most important is that the terminals are accessible from the front of the battery and are located so as to minimize the profile of the battery.

Claims (20)

1. A 6-volt lead-acid battery having terminals capable of being accessed from the front of the battery, comprising a container having front, side, and back walls and first and second cross-partitions extending between the side walls, said cross partitions dividing said container into a front cell defined by said container front and side walls and said first cross-partition, a center cell defined by said container side walls and said first and second partitions, and a back cell defined by said container side and back walls and said second cross-partition, each cell containing an element comprising positive and negative plates and separators therebetween, said plates having a lug for electrically connecting said plates together, said cell elements being electrically connected together, a cover complementally configured with said container side, front, and back walls and sealed thereto, said cover having a first terminal electrically connected to said cell element in said front cell and having a second terminal, a connector bar electrically coupled to said second terminal, said first and second terminals being located in said intermediate cover adjacent said front cell and positioned to provide access thereto from the front of the battery, said intermediate cover having electrolyte fill holes for access to said cells.

2. The battery of claim 1 further comprising a back cell strap coupling the lugs of the plates of a given polarity contained in said at least one back cell, a back cell post electrically connected to said back cell strap, said connector bar being electrically coupled to said back cell post.

3. The battery of claim 2 further comprising a back cell bushing electrically connected to the back cell post and said connector bar being electrically connected to the back cell bushing.

4. The battery of claim 1 wherein the connector bar is metallic and comprises and elongated copper bar.

5. The battery of claim I further comprising a final cover overlaying said cover and sealed thereto. WO 01/61771 PCT/US01/05200 12

6. The battery of claim 5 wherein the intermediate cover comprises an upper surface, and the connector bar being disposed along the intermediate cover upper surface, said final cover overlaying said connector bar.

7. The battery of claim 1 wherein said intermediate cover has an interior surface sealed to said container side walls and said partitions, said interior surface having cover partition surfaces aligning with the respective container partitions and having alignment guides.

8. A battery comprising a container having a front, side, and back walls and partitions dividing said container into cells including a front cell and a back cell, each cell containing an element comprising positive and negative plates and separators therebetween, said plates having a lug for electrically connecting said plates together, said cell elements being electrically connected together, a first front cell terminal bushing electrically connected to the element of said front cell, said first front cell terminal bushing comprising a first terminal said first terminal being disposed substantially adjacent said front cell, a second front cell terminal bushing comprising a second terminal, said second terminal being disposed substantially adjacent said front cell, a connector bar electrically coupled to the second front cell terminal bushing and to the element of said back cell such that the first and second terminals are presented along a front end of the battery.

9. The battery of claim 8 wherein the battery comprises an odd number of rows of cells extending from the front wall.

10. The battery of claim 9 wherein the battery comprises three cells in a single row extending from the front wall.

11. The battery of claim 8 further comprising a back cell strap coupling the lugs of the plates of a given polarity contained in said back cell, a back cell post WO 01/61771 PCT/US01/05200 13 electrically connected to said back cell strap, said connector bar being electrically coupled to said back cell post.

12. The battery of claim 11 further comprising a back cell bushing electrically connected to the back cell post and said connector bar being electrically connected to the back cell bushing.

13. The battery of claim 8 wherein the connector is a metallic bar and comprises an elongated copper bar.

14. The battery of claim 8 wherein said battery is a valve-regulated lead acid battery.

15. The battery of claim 8 wherein the first and second terminals are disposed along a front surface of the battery.

16. The battery of claim 8 wherein the first and second terminals are disposed along a top surface of the battery.

17. The battery of claim 8 wherein the first and second terminals are disposed along the side walls of the battery.

18. The battery of claim 16 further comprising first and second dual terminal bushings.

19. The battery of claim 1 wherein the connector bar is molded into the cover.

20. The battery of claim 8 wherein the connector bar is molded into the cover.