Abstract: An apparatus converts rotary motion of a motor drive shaft into oscillatory motion of a work piece, for example, in a power tool. The apparatus comprises a planetary gear assembly connected to the motor for rotating an output gear. The output gear meshes with a drive gear including a drive pin. The drive pin fits in a yoke slot for reciprocation of the yoke upon rotation of the drive gear. The yoke is operatively connected to the work piece. An air flow system cools the power tool housing. The housing has an inlet aperture in the handle portion and an outlet aperture for placing the interior of the housing in communication with the atmosphere. A wall integral with the handle portion engages the body of the motor housing between a first end and openings in the body. The wall provides a barrier to minimize air flow between an intake air portion of the interior of the housing and an exhaust air portion.

Abstract: An apparatus converts rotary motion of a motor drive shaft into oscillatory motion of a work piece, for example, in a power tool. The apparatus comprises a planetary gear assembly connected to the motor for rotating an output gear. The output gear meshes with a drive gear including a drive pin. The drive pin fits in a yoke slot for reciprocation of the yoke upon rotation of the drive gear. The yoke is operatively connected to the work piece. An air flow system cools the power tool housing. The housing has an inlet aperture in the handle portion and an outlet aperture for placing the interior of the housing in communication with the atmosphere. A wall integral with the handle portion engages the body of the motor housing between a first end and openings in the body.

Abstract: A battery-powered grease gun is provided for enhancing the pressure applied to a blocked grease fitting. The grease comprises a circuit interconnecting the battery and an electric motor. The circuit includes a switch operable by a user and a thermal protector for breaking the circuit at a predetermined temperature. When applying grease to a blocked grease fitting, actuating the switch until the thermal protector reaches the predetermined temperature breaks the circuit until the motor cools and the thermal protector resets for completing the circuit and again energizing the motor. Continuing to maintain the switch in the actuated position until the thermal protector resets causes the pressure in the grease gun to increase with each cycle of the thermal protector.

Abstract: An apparatus converts rotary motion of a motor drive shaft into oscillatory motion of a work piece, for example, in a power tool. The apparatus comprises a planetary gear assembly connected to the motor for rotating an output gear. The output gear meshes with a drive gear including a drive pin. The drive pin fits in a yoke slot for reciprocation of the yoke upon rotation of the drive gear. The yoke is operatively connected to the work piece. An air flow system cools the power tool housing. The housing has an inlet aperture in the handle portion and an outlet aperture for placing the interior of the housing in communication with the atmosphere. A wall integral with the handle portion engages the body of the motor housing between a first end and openings in the body. The wall provides a barrier to minimize air flow between an intake air portion of the interior of the housing and an exhaust air portion.