Motorized tape measure
AssigneeMilwaukee Electric Tool Corporation
InventorsGareth J. Mueckl, Scott Earl McKinster
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Abstract
Various aspects of tape measures with one or more of a sensor, a motor, and a clutch, are shown. The sensors described herein detect, through various mechanisms, the position of the retraction system of a tape measure. The measurements by the sensors may be used to control a motor to adjust an amount of tension in the spiral spring of a tape measure. In various embodiments a motor interacts with the retraction system of the tape measure via a clutch, which moderates an amount of force that the motor can communicate to the retraction system.
Claims20
A tape measure comprising:
- a housing;
- a tape reel rotatably mounted within the housing;
- a rotational axis defined by the tape reel around which the tape reel rotates;
- an elongate tape blade wound around the tape reel;
- a spiral spring coupled to the tape reel, wherein when the elongate tape blade is unwound from the tape reel to extend from the housing the spiral spring stores energy, wherein the spiral spring releasing energy drives rewinding of the elongate tape blade on to the tape reel, and wherein the spiral spring is made of a first material that is electrically-conductive;
- a detector made of a second material that is electrically-conductive;
- and
- a sensor that measures a capacitance of the detector.
A tape measure comprising:
- a housing;
- a tape reel rotatably mounted within the housing;
- a rotational axis defined by the tape reel around which the tape reel rotates;
- an elongate tape blade wound around the tape reel;
- a spiral spring located within the housing, wherein when the elongate tape blade is unwound from the tape reel to extend from the housing the spiral spring stores energy, wherein the spiral spring releasing energy drives rewinding of the elongate tape blade on to the tape reel, and wherein the spiral spring is made of a first material that is electrically-conductive;
- a magnet that emits a magnetic field;
- and
- a detector that measures a change in the magnetic field caused by a repositioning of the spiral spring in response to a portion of the tape blade being extended from or retrieved into the housing.
A tape measure comprising:
- a housing defining an interior surface;
- a tape reel rotatably mounted within the housing;
- a rotational axis defined by the tape reel around which the tape reel rotates;
- an elongate tape blade wound around the tape reel;
- a spiral spring located within the housing, wherein when the elongate tape blade is unwound from the tape reel to extend from the housing the spiral spring stores energy, wherein the spiral spring releasing energy drives rewinding of the elongate tape blade on to the tape reel;
- an axle rotatably mounted within the housing, the axle defining a first end and an opposing second end;
- a motor shaft rotatably mounted within the housing, the motor shaft defining a first end and an opposing second end, wherein the first end of the motor shaft interfaces with the first end of the axle;
- and
- a sensor that measures a position of the second end of the motor shaft.
Dependencies are inferred from the claim text.