Battery powered implement and circuit control therefor

Claim 1

In a battery powered implement, in combination, a tubular cylindrical casing defining a forward load-containing section, an intermediate battery section and a rear switch section, a front end wall closing the forward end of the casing, an electric load disposed in said forward section and provided with electrical input and output terminals, a battery pack including a cylindrical battery disposed within said battery section and having its negative end wall terminal facing forwardly and its positive end wall terminal facing rearwardly, a conductive shunt bar disposed alongside said battery within said battery section and presenting a positive end terminal which faces forwardly and a negative end terminal which faces rearwardly, said battery and shunt bar being of substantially the same effective length and being capable of independent shifting movement bodily within the casing, a first conductive compression spring physically and conductively interposed between the negative end wall terminal of said battery and one terminal of the load and serving to yieldingly bias the battery rearwardly within the casing, a second conductive compression spring physically and conductively interposed between the positive end terminal of the shunt bar and the other terminal of the load and serving to yieldingly bias the shunt bar rearwardly within the casing, a nonconductive circular switch plate mounted in said switch section for rotation within the casing about the central longitudinal axis thereof, means normally preventing axial shifting of the switch plate within the casing, the rear end of said battery pack normally and yieldingly bearing against said switch plate under the influence of said compression springs, a bridging contact bar extending diametrically across said switch plate and movable bodily therewith, said switch plate being movable between and off position wherein at least one of said rearwardly facing terminals is out of contact with said switch bar and an on position wherein both of said rearwardly facing terminals are in contact with said bar, said bridging contact bar being provided with a cam surface thereon which, upon movement of the cam plate to its on position, engages said one terminal and displaces the shunt bar rearwardly against the action of the associated compression springs.