Abstract: A family of cordless electric tools and devices is adapted to use one or more identical rechargeable battery packs and each pack is adapted to interchangeably fit into a pocket or any one of a plurality of pockets in the tool or device in which the pack is employed. The battery pack is positively but releasably retained in the respective pocket of the tool or device with which it is used. A pair of standard AC prongs extend from a flat sidewall of the battery pack which is of a relatively flat, rectangular box-like shape. The prongs are adapted for insertion into a standard AC receptacle for charging the battery pack through rectifier means contained in the pack thus eliminating the need for a separate charger.

Abstract: An upright cordless grass trimmer incorporated incoporates fixed multi-toothed bottom blade and plural sets of top blades which oscillate over the bottom blade to achieve cutting. The sets of top blades are driven by a motor through a gear and cam mechanism and are synchronized so that one top blade set cuts at a different time in the cycle from the other set to achieve a counterbalancing and load leveling effect. A clutch mechanism absorbs abrupt blade stoppage and shock situations and a rechargeable battery pack is releasably received by an elevated cavity in a shroud which mounts over the motor and drive mechanism. An upright handle and electrical control means are attached to the trimmer which allows the operator to operate the trimmer in an upright position.

Abstract: Pairs of planar cutting blades with angularly related cutting edges such as are used in grass shears, and the like, and which are mechanically actuated to move relative to each other and to cut by a scissors-like action are formed in a manner such that during each cutting action the contacting cutting point between each pair of coacting edges moves at a uniform speed. The improved blade construction finds application in shears, particularly cordless, i.e., battery, grass shears, by more nearly equalizing incremental power requirements; by reducing the maximum input power requirements; and by increasing time of performance between battery recharging at a given forward advancement speed of the shear.