Battery powered orthopedic cutting tool

Claim 2

A hand held battery-powered surgical power tool, including: a motor barrel containing therein an electric motor, reduction gear means driven by said motor, and an output drive shaft driven by said reduction gear means, said shaft projecting from an end of said barrel; a pistol grip handle mounted on a side of said barrel in a generally central region of said barrel; and a battery pack cannister affixed to and extending in its entirety beyond the butt end of said pistol grip handle; said tool having its parts so weighted and distributed that, with a battery pack in said cannister, its center of mass falls generally in the region of said pistol grip handle.

Claim 3

The subject matter of claim 1, in which the parts are balanced with said center of mass located inside the boundaries of the pistol grip handle, approximately mid-way between the bottom of the barrel and the top of the battery cannister.

Claim 4

The subject matter of claim 2, wherein said pistol grip handle is formed in its upper front region with a prominence constraining the grip of the operator to be taken therebelow, and said center of mass is spaced below said prominence.

Claim 5

The subject matter of claim 3, wherein said center of mass is located generally mid-way between the front and rearward surfaces of said handle.

Claim 6

The subject matter of claim 1, wherein said battery cannister is in the form of a cylinder, whose axis is generally parallel to the general direction of extension of the pistol grip handle, and including a bottom in the form of a screw cap.

Claim 7

The subject matter of claim 5, wherein a battery pack in said battery cannister comprises a group of cells including a centrally positioned cell surrounded by a plurality of encircling cells.

Claim 8

The subject matter of claim 5, including a cylindrical battery pack container received inside said cannister, a removable top wall on said container, a neck extending upwardly from the top wall of said container there being a bore in said pistol grip handle opening through the butt end thereof for receiving said neck, an insulation plug in said neck and spaced electrical contacts at the top of said plug, electrical leads from said battery pack connected to said contacts, an insulation disc seated in said bore in said pistol with electrical contacts thereon adapted to be engaged by said contacts at the top of said plug, and electric circuit leads extending from said last mentioned contacts through said pistol grip handle and into said motor barrel adapted to energize said motor.

Claim 9

The subject matter of claim 1, wherein said pistol grip handle is inclined generally rearwardly in the direction from its junction with the barrel to its butt end, said battery cannister being cylindrical in shape, with the axis of the cylinder generally vertical when the barrel is held generally horizontal, the axis of said cylindrical cannister substantially intersecting the center of the butt end of the pistol grip handle.