Electrical device having a battery pack with an easy attachment and release mechanism

1. An electrical device, comprising:

a device body defining a cavity;

a battery pack received in said cavity of said device body, said battery pack comprising an arm and a sleeve that at least partially surrounds said arm, said sleeve being rotatable relative to said arm about an axis of rotation;

biasing means configured for urging the sleeve into one direction of rotation around said axis of rotation toward a first position relative to said arm.

2. An electrical device as defined in claim 1 , wherein said sleeve has a sleeve latch element which cooperates with a body latch element provided on said device body and within said cavity for securing said battery pack to said device body.

3. An electrical device as defined in claim 2 , wherein said sleeve latch element on said sleeve and said device body latch element on said device body have angled profile surfaces.

4. An electrical device as defined in claim 1 , wherein said sleeve is configured so that when said battery pack is received in said cavity, said sleeve contacts said device body and is rotatable relative to said device body.

5. An electrical device as defined in claim 1 , wherein said battery pack body is configured so that when said battery pack is received in said cavity, said battery pack body which is non-rotatably coupled with said arm contacts said device body and cannot rotate relative to said device body.

6. An electrical device as defined in claim 1 , wherein said battery pack has a battery pack body, further comprising battery pack alignment means located on said battery pack body and cooperating with device alignment means within said cavity of said device body to prevent said battery pack body from rotating relative to said device body.

7. An electrical device as defined in claim 1 , wherein said biasing means are positioned in a sealed compartment between said sleeve and said arm.

8. An electrical device as defined in claim 1 , further comprising grip-improving means positioned on said sleeve.

9. An electrical device as defined in claim 1 , wherein said battery pack has a battery pack body and an end plate that is secured to said arm and which secures said sleeve to said arm and said battery pack body.

10. An electrical device as defined in claim 1 , wherein the electrical device is configured as a hand-held power tool, and said cavity is substantially within a handle which is used for gripping said hand-held power tool.

11. An electrical device as defined in claim 1 , wherein the electrical device is configured as a battery charger for charging said battery pack.

12. A electrical device a defined in claim 1 , wherein said first position is configured as a resting position and latched position for said battery pack.

13. An electrical device as defined in claim 1 , wherein said sleeve is directly secured to said arm.

14. An electrical device as defined in claim 13 , wherein the other end of said biasing means is anchored to a shelf on the inside surface of said sleeve.

15. An electrical device as defined in claim 1 , wherein one end of said biasing means is anchored to a protrusion projecting from said arm.

16. A battery pack comprising:

an arm; and

a sleeve that at least partially surrounds said arm, said sleeve being rotatable relative to said arm along an axis of rotation;

biasing means configured for urging said sleeve into one direction of rotation around said axis of rotation toward a first position relative to said arm.

17. A battery pack as defined in claim 16 , wherein said biasing means are positioned in a sealed compartment between said sleeve and said arm.

18. A battery pack as defined in claim 16 , further comprising grip-improving means positioned on said sleeve.

19. A battery pack as defined in claim 16 , wherein said battery pack has a battery pack body and an end plate that is secured to said arm and which secures said sleeve to said arm and said battery pack body.

20. A battery pack as defined in claim 16 , wherein said sleeve is directly secured to said arm.

21. A battery pack as defined in claim 16 , wherein said first position is configured as a resting position and latched position for said battery pack.

22. A battery pack as defined in claim 16 , wherein one end of said biasing means is anchored to a protrusion projecting from said arm.

23. A battery pack as defined in claim 16 , wherein the other end of said biasing means is anchored to a shelf on the inside surface of said sleeve.