Power tool torque overload clutch
AssigneeBlack & Decker Inc.
InventorJonathan Armstrong
Life of this patent
Estimating the term…
Abstract
A torque overload clutch for an electrical power tool, such as a percussion hammer drill, is provided. The clutch is accommodated in a cavity in a gear cog. Spring washers are used to urge ball bearings into indentations formed in the base of the cavity. The ball bearings are accommodated in cavities formed in a drive plate which engages with the spindle drive of the power tool. The spring washers are held in position by a circlip or a threaded plate. The threaded plate arrangement provides means for compressing the spring washers with a consistent force across a manufactured batch. A method of manufacturing the clutch is also disclosed.
Claims9
An electrically powered tool comprising:
- a housing;
- a motor disposed in the housing;
- a drive shaft in rotatable engagement with the motor;
- a drive gear located on and rotatable by the drive shaft;
- an output spindle having a first axial end and a second axial end;
- an output gear disposed on and rotatable relative to the output spindle, the output gear including an interior surface at least partially defining a cavity including an opening, and the interior surface including a first torque transmitting surface;
- a thrust plate fixed relative to the output gear;
- a first clutch plate located around the output spindle and inside the cavity between the thrust plate and the first torque transmitting surface, the first clutch plate in axially slidable and rotatable driving engagement with the output spindle, and including a second torque transmitting surface;
- and
- a clutch spring located in the cavity between the thrust plate and the first clutch plate and arranged to maintain the first torque transmitting surface in driving engagement with the second torque transmitting surface gear when torque is less than a predetermined threshold.
Dependencies are inferred from the claim text.