Battery charger with a terminal protector

• US 6,346,793 B1
• Filed: 10/10/2000
• Issued: 02/12/2002
• Est. Priority Date: 10/26/1999
• Status: Active Grant

• Current Assignee: Makita Corporation
• Original Assignee: Makita Corporation
• Inventors: Shibata, Yoshinori, Masuda, Junichi
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): TIBBITS, PIA FLORENCE
• Application Number:
  US09/686,101
• Time in Patent Office: 490 Days
• Field of Search: 429/97, 429/100, 320/107, 320/110, 320/113, 320/114, 320/115, 213/103, 213/107, 213/108
• US Class Current: 320/113
• CPC Class Codes: H02J 7/0042 characterised by the mechanical construction

Abstract

A charger (1) includes a box enclosure (2), terminals (11, 12, 13), and a protective terminal cover (14) which in turn includes a top plate (15) extending at right angles to a pair of guide rails (6). The terminal cover (14) is pivotally supported by a pair of pivot pins (17) inside the box enclosure (2) such that the terminal cover (14) is pivotal between a protruding position, in which the top plate (15) is located directly above and protects the terminals and a retracted position, in which the terminal cover (14) is completely retracted inside the box enclosure (2). The terminal cover (14) is biased to the protruding position by a torsion spring (18) when a battery pack (40) is not set on the charger (1) for a recharge, whereas the terminal cover is manually moved to the retracted position against the biasing force of the torsion spring when the battery pack is slid on the charger into a set position.

Claims

1. A charger for charging a battery pack, comprising:

a housing including on an outside surface thereof a connecting portion to which a battery pack is removably attached;

a plurality of charger terminals provided in the connecting portion for establishing electrical connection with the battery pack upon attachment of the battery pack to the connecting portion; and

protective means provided in the connecting portion, the protective means being adapted to cover the charger terminals when the battery pack is not attached to the connecting portion and to be actuated by a motion of attaching the battery pack to the connecting portion to expose the charger terminals when the battery pack is attached to the connecting portion.

2. A charger in accordance with claim 1, wherein the protective means comprises a rotatable cover adapted to rotate between a protruding position, which is attained when the battery pack is not attached to the connecting portion, in which at least a portion of the cover protrudes from the housing and the connection portion so as to at least partially cover the charger terminals, and a retracted position, which is attained when the battery pack is attached to the connecting portion, in which the cover is at least partially retracted inside the housing.

3. A charger in accordance with claim 2 further comprising

guide means provided in the connecting portion for allowing the battery pack to be slid along a predetermined guide locus into attachment to the connecting portion, and

biasing means for urging the protective cover to the protruding position when the battery pack is not attached to the connecting portion,

wherein the battery pack is brought into contact with and rotate the protective cover to the retracted position against the biasing force of the biasing means when the pack is slid along the guide locus.

4. A charger in accordance with claim 3, wherein the guide locus has a front end at which a front portion of the battery pack is placed on the charger prior to sliding of the charger into attachment with the connecting portion and a rear end to which the battery pack is slid into attachment with the connecting portion, and

wherein the protective cover is pivotally disposed between the front and rear ends of the guide locus so as to pivot toward the rear end to the retracted position when the battery pack is slid to the rear end of the guide locus.

5. A charger in accordance with claim 3, wherein the guide means and the guide locus are slanted such that the rear end of the guide locus is located at a lower level than the front end, facilitating sliding and thus attachment of the battery pack to the connecting portion.

6. A charger in accordance with claim 4, wherein the protective cover includes a transverse top plate extending substantially orthogonal to the guide locus, a pair of vertical side plates connected to the top plate, and a pair of pivots for supporting the side plates inside the housing so as to allow the protective cover to pivot along the guide locus between said two positions, the top plate being located outside the housing directly above the charger terminals to protectively cover the charger terminals when the battery pack is not attached to the connecting portion.

7. A charger in accordance with claim 6 further comprising a transverse slit formed in the connecting portion for allowing the top plate to pivot between the two positions and a pair of side slits provided in the connecting portion for allowing the side plates to pivot between the two positions.

8. A charger in accordance with claim 6, wherein the top plate has a curved cross section on a plane parallel to the guide locus, the curvature substantially coinciding with the locus of the pivoting motion of the top plate, and wherein the transverse slit is at least partially defined by at least one wall surface of the housing having a curvature substantially concentric with said locus of the pivoting motion.

9. A charger in accordance with claim 6, wherein the guide means includes a pair of guide rails for slidably engaging the battery pack, and wherein the biasing means includes a coil spring fitted on one of the side plates.

10. A charger in accordance with claim 1, wherein the protective means includes a pair of rotatable covers, the charger further comprising

guide means provided in the connecting portion for allowing the battery pack to slide along a guide locus into attachment to the connecting portion,

biasing means for urging the rotatable covers to respective protruding positions, which are attained when the battery pack is not attached to the connecting portion, in which at least a portion of each rotatable cover protrudes out of the housing and the connection portion so as to cover the charger terminals, and

a button located in the guide locus and depressed by the battery pack when the pack is placed on the connecting portion prior to sliding of the battery pack on the charger into attachment to the connecting portion, wherein when depressed by the battery pack, the button is adapted to actuate the rotatable covers to rotate against the biasing force of the biasing means from the respective protruding positions to respective retracted positions, in which the covers are retracted inside the housing so as to expose the charger terminals.

11. A charger in accordance with claim 10, wherein the guide locus has a front end at which a front portion of the battery pack is placed on the charger prior to sliding of the charger into attachment with the connecting portion and a rear end to which the battery pack is slid into attachment with the connecting portion, and

wherein the rotatable covers are pivotally disposed between the front and rear ends of the guide locus and the button is located between the front end and the rotatable covers.

12. A charger in accordance with claim 11, wherein the rotatable covers are pivotally supported inside the housing by a common pivot extending parallel to the guide locus and are substantially symmetrical about a plane passing through the common pivot so as to pivot away from each other in directions orthogonal to the guide locus when the button is depressed, and wherein opposing continuous edges of the covers abut each other on said plane passing through the common pivot when the two covers are in the respective protruding positions so as to completely cover the charger terminals outside the housing.

13. A charger in accordance with claim 11, wherein the housing includes a plurality of slits provided therein to permit the covers to rotate between the respective protruding positions and the respective retracted positions.

14. A charger in accordance with claim 11, wherein the guide locus and the guide means are slanted such that the rear end is located at a lower level than the front end, thus facilitating sliding and attachment of the battery pack to the charger.

15. A charger in accordance with claim 12, wherein the biasing means includes a coil spring fitted on the rotatable covers, and wherein the guide means includes a pair of guide rails for slidably engaging the battery pack.

16. A charger in accordance with claim 10, wherein the button extends through the connecting portion and is adapted to be depressed by the weight of the battery pack to actuate the rotatable covers to rotate to the respective retracted positions when the pack is placed on the button.

17. A charger in accordance with claim 10, wherein each cover includes a curved top plate having an identical arc-shaped cross section on a plane orthogonal to the guide locus and a pair of vertical side plates connected to the top plate such that when the covers abut each other in the protruding positions, said cross sections of the top plates form a continuous arc.

18. A charger for charging a battery pack, comprising:

a housing including on an outside surface thereof a connecting portion to which a battery pack is removably attached;

a plurality of charger terminals provided in the connecting portion for establishing electrical connection with the battery pack upon attachment of the battery pack to the connecting portion;

protective means comprising a rotatable cover provided in the connecting portion, the protective means being adapted to cover the charger terminals when the battery pack is not attached to the connecting portion and to be actuated by a motion of attaching the battery pack to the connecting portion to expose the charger terminals when the battery pack is attached to the connecting portion, wherein the rotatable cover is adapted to rotate between a protruding position, which is attained when the battery pack is not attached to the connecting portion, in which at least a portion of the cover protrudes from the housing and the connection portion so as to at least partially cover the charger terminals, and a retracted position, which is attained when the battery pack is attached to the connecting portion, in which the cover is at least partially retracted inside the housing; and

a guide means provided in the connecting portion for allowing the battery pack to be slid along a predetermined guide locus into attachment to the connecting portion.

19. A charger in accordance with claim 18, further comprising

biasing means for urging the protective cover to the protruding position when the battery pack is not attached to the connecting portion, wherein the battery pack is brought into contact with and rotates the protective cover to the retracted position against the biasing force of the biasing means when the pack is slid along the guide locus.