Battery pack for hand-held electric machine tools

• US 20060001404A1
• Filed: 06/29/2005
• Published: 01/05/2006
• Est. Priority Date: 06/30/2004
• Status: Active Grant

• Current Assignee: Hilti Aktiengesellschaft (Hilti Martin Family Trust)
• Original Assignee: Hilti Aktiengesellschaft (Hilti Martin Family Trust)
• Inventors: Ziegler, Bernd, Heigl, Bernd, Krebs, Stephan
• Granted Patent: US 7,498,774 B2
• Time in Patent Office: Days
• US Class Current: 320/150
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/443 in response to temperature
• CPC Class Codes: H01M 10/486 for measuring temperature
• CPC Class Codes: H02H 5/042 using temperature dependent resistors
• CPC Class Codes: H02H 7/18 for batteries; for accumulators
• CPC Class Codes: H02J 7/0029 with safety or protection devices or circuits
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A battery pack (2) for an associated hand-held electric machine tool (1) and for an associated charging device (13) including an analog temperature sensor (3) with a negative temperature coefficient and a temperature measuring interface (4) accessible from the outside. Battery protection electronics (5) arranged in the hand-held electric machine tool (1) and in the charging device (13), which have a battery protection logic (6) and a power switch (8) that is arranged in the circuit path (7) of the battery pack (2) can be influenced. The battery pack (2) is provided with an emergency protection circuit (10), which is connected in parallel with the analog temperature sensor (3) and which, in emergency situations, can actively reduce the total resistance (R) measurable from the outside via the temperature measuring interface (4).

Claims

1. A battery pack for an associated hand-held electric machine tool (1) and for an associated charging device (13) comprising an analog temperature sensor (3) with a negative temperature coefficient and a temperature measuring interface (4) accessible from the outside and by which battery protection electronics (5) arranged in the hand-held electric machine tool (1) and in the charging device (13) and which have a battery protection logic (6) and a power switch (8) arranged in the circuit path (7) of the battery pack can be influenced, wherein the battery pack is provided with an emergency protection circuit (10) connected in parallel with the analog temperature sensor (3) and which, in emergency situations, can actively reduce the total resistance (R) that is measurable from the outside via the temperature measuring interface (4).

2. The battery pack of claim 1, wherein the emergency protection circuit (10) is constructed as an integrated circuit.

3. The battery pack of claim 1, further comprising battery cells (11) constructed internally as Li-ion cells.