Battery Pack and Cordless Power Tool Having The Same

A combination of a power tool and a power pack comprising:

• the power tool having a motor and a receiving portion;
• the power pack having a plurality of battery cells being assembled into the receiving portion so as to supply electric power from the power pack to the motor;
• the power pack comprising:
• an insertion portion insertable into the receiving portion through an open end of the receiving portion, the insertion portion delimiting an elongated space therein extending in an elongated direction away from the open end of the receiving portion, wherein the insertion portion does not accommodate a battery cell therein;
• a terminal holding portion accommodated in a part of the elongated space which is at a position away from the open end of the receiving portion when the insertion portion is inserted into the receiving portion;
• an accommodation portion having a bottom surface and side walls connected to the insertion portion and disposed outside of the power tool when the insertion portion is inserted into the receiving portion;
• the accommodation portion having the plurality of battery cells accommodated therein for supplying the electrical power to the motor, each of the plurality of battery cells having a positive terminal and a negative terminal and a longitudinal axis, wherein all of the plurality of battery cells of the power pack only being accommodated into the accommodation portion so that none of the plurality of battery cells is accommodated in the insertion portion, each of the plurality of battery cells of the power pack having the longitudinal axis thereof oriented substantially parallel to the bottom surface of the accommodation portion and in a substantially perpendicular extending direction at least with respect to the elongated extending direction of the elongated space of the insertion portion;
• and
• an electrical circuit board disposed in the elongated space of the insertion portion at least at a position between the terminal holding portion and the accommodation portion, the electrical circuit board extending in an elongated direction of the elongated space, and the electrical circuit board having a circuit which controls a switching element for electrical protection of at least one of the plurality of battery cells, at least a major portion of the circuit board being located in the insertion portion.

A power pack to be assembled into a power tool provided with a portion having an internal space for receiving a part of the power pack having a plurality of battery cells so as to supply electrical power from the power pack to the power tool, the power pack comprising:

• an insertion portion insertable into the internal space, the insertion portion delimiting an elongated space extending in an elongated direction, wherein the insertion portion does not accommodate a battery cell therein;
• a terminal holding portion accommodated in an upper portion of the insertion portion;
• an accommodation portion having a bottom surface and side walls connected to the insertion portion and disposed outside of the power tool when the insertion portion is inserted into the internal space, the accommodating portion having the plurality of battery cells accommodated therein for supplying the electrical power to the power tool, each of the plurality of battery cells having a positive terminal and a negative terminal and a longitudinal axis, wherein the plurality of battery cells of the power pack are accommodated into the accommodation portion so that none of the plurality of battery cells of the power pack is accommodated in the insertion portion, each of the plurality of battery cells of the power pack having the longitudinal axis thereof oriented substantially parallel to the bottom surface of the accommodation portion and in a substantially perpendicular extending direction at least with respect to the elongated extending direction of the elongated space of the insertion portion;
• and
• an electrical circuit board disposed in the insertion portion and extending between the plurality of battery cells and the terminal holding portion, the electrical circuit board having a circuit which controls a switching element for electrical protection of at least one of the plurality of battery cells, the circuit board being located in the insertion portion;
• wherein the term of upper is utilized based upon an orientation of the power tool in which the power tool is located above the power pack when the power pack is assembled into the power tool.

A combination of a power tool and a power pack comprising:

• the power tool having a motor and a receiving portion;
• the power pack having a plurality of battery cells being assembled into the receiving portion so as to supply electrical power from the power pack to the motor;
• the power pack comprising:
• an insertion portion insertable into the receiving portion, the insertion portion delimiting an elongated space extending in an elongated direction, wherein the insertion portion does not accommodate a battery cell therein;
• a terminal holding portion accommodated in an upper portion of the insertion portion;
• an accommodation portion having a bottom surface and side walls connected to the insertion portion and disposed outside of the power tool when the insertion portion is inserted into the receiving portion;
• the accommodating portion having the plurality of battery cells of the power pack accommodated therein for supplying the electrical power to the power tool so that none of the plurality of battery cells of the power pack is accommodated in the insertion portion, each of the plurality of battery cells having a positive terminal and a negative terminal and a longitudinal axis, each of the plurality of battery cells of the power pack having the longitudinal axis thereof oriented substantially parallel to the bottom surface of the accommodating portion and in a substantially perpendicular extending direction at least with respect to the elongated extending direction of the elongated space of the insertion portion;
• and
• an electrical circuit board disposed in the insertion portion and extending between the plurality of battery cells and the terminal holding portion, the electrical circuit board having a circuit which controls switching element for electrical protection of at least one of the plurality of battery cells, the circuit board being located in the insertion portion;
• wherein the term of upper is utilized based upon an orientation of the power tool in which the power tool is located above the power pack when the power pack is assembled into the power tool.

A power pack comprising:

• a housing including an upper portion extending in a first direction so as to delimit an elongated space extending in an elongated direction and a lower portion, and an accommodating portion connected to the lower portion, the accommodating portion having a bottom surface and side walls, and having a width extending in a second direction which is transverse to the first direction and which is greater than a width extending in the second direction of the upper portion, wherein the upper portion does not accommodate a battery cell therein;
• a plurality of battery cells of the power pack accommodated in the accommodating portion of the housing;
• a circuit board extending in the first direction and positioned above the plurality of battery cells of the power pack accommodated in the accommodating portion, the circuit board being at least partially accommodated in the upper portion of the housing;
• a terminal positioned above the circuit board in the first direction;
• a switching element fixed to the circuit board;
• and
• a heat sink connected to the switching element and extending in the first direction, at least a part of the heat sink being accommodated in the upper portion;
• wherein all of the plurality of battery cells of the power pack are accommodated in the accommodating portion so that none of the plurality of battery cells of the power pack is accommodated in the upper portion of the housing, each of the plurality of battery cells having a positive terminal and a negative terminal and a longitudinal axis;
• and
• wherein the plurality of battery cells of the power pack include a first battery cell having the longitudinal axis thereof extending in the second direction substantially in parallel to the bottom surface of the accommodating portion and substantially perpendicularly to the extending first direction of the circuit board, a second battery cell having the longitudinal axis thereof extending in the second direction substantially in parallel to the bottom surface of the accommodating portion and substantially perpendicularly to the extending first direction of the circuit board, and a connection piece connecting the first lithium ion battery cell to the second lithium ion battery cell.