ELECTRIC TOOL POWERED BY A PLURALITY OF BATTERY PACKS AND ADAPTER THEREFOR

• US 20110198103A1
• Filed: 09/22/2010
• Published: 08/18/2011
• Est. Priority Date: 02/12/2010
• Status: Active Grant

• Current Assignee: Makita Corporation
• Original Assignee: Makita Corporation
• Inventors: Suzuki, Hitoshi
• Granted Patent: US 8,813,866 B2
• Time in Patent Office: Days
• US Class Current: 173/46
• CPC Class Codes: A47L 9/2884 Details of arrangements of batteries or their installation
• CPC Class Codes: B25F 5/00 Details or components of portable power-driven tools not particularly related to the operations performed and not otherwise provided for
• CPC Class Codes: H02J 7/00306 Overdischarge protection
• CPC Class Codes: H02J 7/00309 Overheat or overtemperature protection
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: H02J 7/0063 with circuits adapted for supplying loads from the battery
• CPC Class Codes: H02M 1/10 Arrangements incorporating converting means for enabling loads to be operated at will from different kinds of power supplies, e.g. from ac or dc

Abstract

An electric power tool is powered by a plurality of battery packs connected in series. The electric power tool comprises a controller configured to receive signals outputted from the integrated circuits located in each of the battery packs. A first voltage level-shifter is disposed between the controller of the electric power tool and one of the integrated circuits of the battery packs. The first voltage level-shifter is configured to shift the voltage level of the signal outputted from the respective integrated circuit to the tool controller to an acceptable level for the controller.

Claims

1. An electric power tool configured to be powered by at least a first battery pack and a second battery pack connected in series, wherein each battery pack comprises an integrated circuit, the electric power tool comprising:

a controller configured to receive signals respectively outputted from the integrated circuits of the first and second battery packs, wherein the integrated circuit of the first battery pack outputs a first signal at a first voltage level and the integrated circuit of the second battery pack outputs a second signal at a second voltage level different from the first voltage level; and

a first level-shifter disposed between the controller and the integrated circuit of the first battery pack, the first level-shifter being configured to shift the first voltage level of the first signal to the second voltage level that is usable by the controller.

2. The electric power tool as in claim 1, further comprising:

a second level-shifter disposed between the controller and the integrated circuit of the first battery pack, the second level-shifter being configured to shift the second voltage level of a signal outputted from the controller to the first voltage level that is usable by the integrated circuit of the first battery pack.

3. The electric power tool as in claim 1, further comprising:

at least one cut-off switch disposed between the controller and the integrated circuit of the first battery pack, the cut-off switch being configured to cut off an electrical connection between the controller and the integrated circuit of the first battery pack.

4. The electric power tool as in claim 3, wherein the at least one cut-off switch is controllable by the controller.

5. The electric power tool as in claim 1, further comprising:

at least one bypass circuit comprising a diode that electrically connects a positive electrode and a negative electrode of one of the battery packs.

6. The electric power tool as in claim 5, wherein the at least one bypass circuit further comprises a fuse.

7. The electric power tool as in claim 1, further comprising:

a second level-shifter disposed between the controller and the integrated circuit of the first battery pack, the second level-shifter being configured to shift the second voltage level of a signal outputted from the controller to the first voltage level that is usable by the integrated circuit of the first battery pack;

at least one cut-off switch disposed between the controller and the integrated circuit of the first battery pack, the cut-off switch being configured to cut off an electrical connection between the controller and the integrated circuit of the first battery pack; and

at least one bypass circuit comprising a diode that electrically connects a positive electrode and a negative electrode of one of the battery packs.

8. An electric power tool configured to be powered by a plurality of battery packs connected in series, the electric tool comprising:

at least one bypass circuit comprising a diode that electrically connects a positive electrode and a negative electrode of one of the battery packs.

9. The electric power tool as in claim 8, wherein the at least one bypass circuit further comprises a fuse.

10. An adapter configured for detachably connecting a plurality of battery packs to a main body of an electric power tool, wherein each battery pack comprises an integrated circuit and the adapter is detachable from the main body of the electric power tool, the adapter comprising:

a controller configured to receive signals respectively outputted from the integrated circuit of the first and second battery packs, wherein the integrated circuit of the first battery pack outputs a first signal at a first voltage level and the integrated circuit of the second battery pack outputs a second signal at a second voltage level different from the first voltage level; and

a first level-shifter disposed between the controller and the integrated circuit of the first battery pack, the first level-shifter being configured to shift the first voltage level of the first signal to the second voltage level that is usable by the controller.

11. The adapter as in claim 10, further comprising:

a second level-shifter disposed between the controller and the integrated circuit of the first battery pack, the second level-shifter being configured to shift the second voltage level of a signal outputted from the controller to the first voltage level that is usable by the integrated circuit of the first battery pack.

12. The adapter as in claim 10, further comprising:

at least one cut-off switch disposed between the controller and the integrated circuit of the first battery pack, the cut-off switch being configured to cut off an electrical connection between the controller and the integrated circuit of the first battery pack.

13. The adapter as in claim 12, wherein the at least one cut-off switch is controlled by the controller.

14. The adapter as in claim 10, further comprising:

at least one bypass circuit comprising a diode that electrically connects a positive electrode and a negative electrode of one of the battery packs.

15. The adapter as in claim 14, wherein the at least one bypass circuit further comprises a fuse.

16. The adapter as in claim 10, further comprising:

a second level-shifter disposed between the controller and the integrated circuit of the first battery pack, the second level-shifter being configured to shift the second voltage level of a signal outputted from the controller to the first voltage level that is usable by the integrated circuit of the first battery pack;

at least one cut-off switch disposed between the controller and the integrated circuit of the first battery pack, the cut-off switch being configured to cut off an electrical connection between the controller and the integrated circuit of the first battery pack; and

at least one bypass circuit comprising a diode that electrically connects a positive electrode and a negative electrode of one of the battery packs.

17. An adapter configured for connecting a plurality of battery packs to a main body of an electric power tool, the adapter being detachable from the main body of the electric power tool, the adapter comprising:

at least one bypass circuit comprising a diode that electrically connects a positive electrode and a negative electrode of one of the battery packs.

18. The adapter as in claim 17, wherein the at least one bypass circuit further comprises a fuse.

19. A power supply interface for an electric power tool comprising:

a first battery pack interface configured to detachably attach a first battery pack and comprising a first positive battery electrode input terminal, a first negative battery electrode input terminal and a first battery controller interface terminal,

a second battery pack interface configured to detachably attach a second battery pack and comprising a second positive battery electrode input terminal, a second negative battery electrode input terminal and a second battery controller interface terminal, the first negative battery electrode input terminal being electrically connected in series with the second positive battery electrode input terminal, wherein the first positive battery electrode input terminal is electrically connectable with the second negative battery electrode input terminal via a load of the electric power tool, and

a first DC-to-DC converter electrically connected with the first battery controller interface terminal and configured to proportionally step down a voltage of a first signal received at the first battery controller interface terminal.

20. A power supply interface as in claim 19, further comprising:

a second DC-to-DC converter electrically connected with the first battery controller interface terminal and configured to proportionally step up a voltage of a second signal received at the second DC-to-DC-converter to be supplied to the first battery controller interface terminal.

21. A power supply interface as in claim 20, further comprising:

a first switch electrically connected between the first battery controller interface terminal and the first DC-to-DC converter and

a second switch electrically connected between the first battery controller interface terminal and the second DC-to-DC converter,

wherein the first and second switches are controllable such that;

the battery controller interface terminal is electrically connected with the first DC-to-DC converter when the first signal is being input at the first battery controller interface terminal and

the battery controller interface terminal is electrically connected with the second DC-to-DC converter when the second signal is being input at the first DC-to-DC converter.

22. A power supply interface as in claim 21, further comprising:

a first battery pack attached to the first battery pack interface and comprising a first controller having an output terminal electrically connected to the first battery controller interface terminal, the first controller being configured to output an autostop signal as the first signal to the first battery controller interface terminal when the first controller determines that the first battery pack is experiencing an abnormality or requires recharging, and

a second battery pack attached to the second battery pack interface and comprising a second controller having an output terminal electrically connected to the second battery controller interface terminal, the second controller being configured to output an autostop signal to the second battery controller interface terminal when the second battery controller determines that the second battery pack is experiencing an abnormality or requires recharging.

23. A power supply interface as in claim 22, further comprising:

a first diode having an anode electrically connected to the first positive battery electrode input terminal and a cathode electrically connected to a first negative battery electrode input terminal, the first diode having the property that it becomes conductive when a reverse voltage is generated across the first positive battery electrode input terminal and the first negative battery electrode input terminal, and

a second diode having an anode electrically connected to the second positive battery electrode input terminal and a cathode electrically connected to a second negative battery electrode input terminal, the second diode having the property that it becomes conductive when a reverse voltage is generated across the second positive battery electrode input terminal and the second negative battery electrode input terminal.

24. A power supply interface as in claim 23, further comprising a fuse electrically connected between the first negative battery electrode input terminal and the second positive battery electrode input terminal.

25. A power supply interface as in claim 24, further including a controller comprising:

an input terminal electrically connected to the first DC-to-DC converter,

a first output terminal electrically connected to the second DC-to-DC converter, and

a second output terminal electrically connected to the first and second switches, the controller being configured to cause the first switch to conduct when the first signal is received at the first battery controller interface terminal and to cause the second switch to conduct when the controller outputs the second signal at the first output terminal.

26. A power supply interface as in claim 25, further comprising a housing having a first portion with the first and second battery pack interfaces disposed on a surface thereof, wherein the housing further comprises a second portion with a power tool interface disposed on a surface thereof, the power tool interface comprising:

a positive battery electrode output terminal electrically connected to the first positive battery electrode input terminal, and

a negative battery electrode output terminal electrically connected to the second negative battery electrode input terminal,

wherein the power tool interface is configured to be detachably attachable to a battery pack interface of the electric power tool.

27. A power supply interface as in claim 26, wherein the first portion of the housing is connected to the second portion of the housing via an electric cord.

28. A power supply interface as in claim 27, further comprising an attachment device disposed on the first portion, the attachment device being configured to attach to at least one of an article worn by a user and a body part of the user.

29. A power tool comprising:

an electric load disposed within a tool housing, and

the power supply interface of claim 25, wherein the first and second battery pack interfaces are disposed on a surface of the tool housing and the first positive battery electrode input terminal and the second negative battery electrode input terminal are selectively electrically connectable to the electric load.

30. A power supply interface for an electric power tool comprising:

a first battery pack interface configured to detachably attach a first battery pack and comprising a first positive battery electrode input terminal and a first negative battery electrode input terminal,

a second battery pack interface configured to detachably attach a second battery pack and comprising a second positive battery electrode input terminal and a second negative battery electrode input terminal, the first negative battery electrode input terminal being electrically connected in series with the second positive battery electrode input terminal, wherein the first positive battery electrode input terminal is electrically connectable with the second negative battery electrode input terminal via a load of the electric power tool,

a first diode having an anode electrically connected to the first positive battery electrode input terminal and a cathode electrically connected to the first negative battery electrode input terminal, the first diode having the property that it becomes conductive when a reverse voltage is generated across the first positive battery electrode input terminal and the first negative battery electrode input terminal, and

a second diode having an anode electrically connected to the second positive battery electrode input terminal and a cathode electrically connected to the second negative battery electrode input terminal, the second diode having the property that it becomes conductive when a reverse voltage is generated across the second positive battery electrode input terminal and the second negative battery electrode input terminal.

31. A power supply interface as in claim 30, further comprising a fuse electrically connected between the first negative battery electrode input terminal and the second positive battery electrode input terminal.

32. A power supply interface as in claim 31, further comprising a housing having a first portion with the first and second battery pack interfaces disposed on a surface thereof, wherein the housing further comprises a second portion with a power tool interface disposed on a surface thereof, the power tool interface comprising:

a positive battery electrode output terminal electrically connected to the first positive battery electrode input terminal, and

a negative battery electrode output terminal electrically connected to the second negative battery electrode input terminal,

wherein the power tool interface is configured to be detachably attachable to a battery pack interface of the power tool.

33. A power supply interface as in claim 32, wherein the first portion of the housing is physically and electrically connected to the second portion of the housing via an electric cord.

34. A power supply interface as in claim 33, further comprising an attachment device disposed on the first portion, the attachment device being configured to attach to at least one of an article worn by a user and a body part of the user.

35. A power supply interface as in claim 34, further comprising a power FET electrically connected between one of (i) the positive battery electrode output terminal and the first positive battery electrode input terminal and (ii) the negative battery electrode output terminal and the second negative battery electrode input terminal, the power FET being configured to shut-off current flow to the load of the power tool in case a short-circuit is detected.

36. A power tool comprising:

an electric load disposed within a tool housing, and

the power supply interface of claim 32, wherein the first and second battery pack interfaces are disposed on a surface of the tool housing and the first positive battery electrode input terminal and the second negative battery electrode input terminal are selectively electrically connectable to the electric load.