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US 4,204,580 AGranted
Forward biased switch for a reversible hammer drill
AssigneeThe Singer Company
InventorDavid J. Nalley
Life of this patent
Estimating the term…
Abstract
A hammer drill having a reversible switch which is forward biased normally to prevent the drill from operating in the hammer mode while the switch is in the reverse position. This is a precaution to prevent damage to the clutch teeth which are designed for ratchet action when the tool is operated in the forward direction, but will lock down in reverse to stall tool or damage the mechanism.
Claims4
A forward biased switch assembly for a reversible hammer drill comprising:
- a. a housing,
- b. a motor journaled in the housing,
- c. a hammer drill mechanism selectively operable as a drill or as a hammer drill,
- d. a trigger switch in circuit with the motor to turn the motor on and off,
- e. a reversing switch in circuit with the motor and having an actuating button selectively to place switch into the operative positions of forward or reverse,
- f. a lever pivotally connected to the reversing switch to shift the actuating button between the forward position and the reverse position,
- g. a biasing means including a spring connected in the housing to bias the lever and cause it to urge the actuating button continuously in the forward position whereby the operator is free to manually shift the lever to place the actuating button in the reverse position.
4 more elements
Dependencies are inferred from the claim text.