Automatically retracting chalk line marking tool
OwnerAnne Nemesinventor
Life of this patent
Estimating the term…
Abstract
A pistol-shaped automatically retracting chalk-line dispenser comprises a three-member housing enclosing two separate chambers. The upper, chalk-receiving chamber, contains a double-walled chalk-line spool and a line-guiding roller. A seal on the chalk-line spool shaft prevents chalk dust from entering the second chamber, which contains drive gears, the line-retracting spring, and a trigger-actuated latching brake mechanism. In one embodiment, a finger-like projection from the trigger is initially brought to bear on a rotating cap to brake the rate of line retraction as the trigger is pulled rearwardly. If the trigger is pulled back more than a predetermined distance, the finger-like projection snaps into engagement between the teeth of a sprocket attached to the cap and thus locks the retraction mechanism.
Claims15
An automatically retracting chalk-line dispenser comprising a housing;
- a chalk-line spool coupled to a first shaft for rotation therewith, the spool disposed in a chalk-receiving chamber;
- a line-retracting spring coupled to a second shaft;
- and a gear arrangement coupling the first shaft to the second shaft;
- the dispenser further comprising:
- a shaft seal adjacent a wall of the chalk-receiving chamber, the first shaft adapted to rotate within the seal, the seal intermediate the spool and the spring;
- and
- a trigger attached to the housing for pivotal motion between a latched and a released position, a projection portion of the trigger coacting with the second shaft so as to prevent the second shaft from rotating when the trigger is in the latched position, the projection not coacting with the second shaft when the trigger is in the released position, the projection frictionally coacting with the second shaft so as to brake the rotation thereof when the trigger is intermediate the latched and the released positions.
An automatically retracting chalk-line dispenser comprising:
- a first, chalk-receiving, chamber containing therein a chalk-line spool the first chamber adapted to receive therein chalk dust, the chalk line spool rotating with a spool shaft;
- a spool shaft seal intermediate the chalk-receiving chamber and a second chamber containing therein a line-retracting spring, the spool shaft extending into the second chamber and journalled for rotation within the seal, the seal adapted to prevent chalk from coming into contact with the spring;
- a pinion gear attached to a portion of the spool shaft within the second chamber, the pinion gear drivingly engaged with a spur gear attached to a second shaft, the second shaft driven by the line-retracting spring;
- and
- braking means movable between a braking position in which the braking means frictionally acts upon a portion of the second shaft distal from the spur gear, and a released position, in which the braking means does not frictionally act upon the second shaft.
A chalk line dispenser comprising:
- a spirally wound line-retracting spring having a first end at a center of the spiral and a second end at an outer circumference thereof, the line-retracting spring disposed in a cylindrical cartridge having a cylindrical wall with a slot therethrough, the second end of the spring extending outwardly through the slot;
- a drive gear fixedly attached to a first shaft the first shaft engaging the first end of the line-retracting spring;
- a pinion gear fixedly attached to a second shaft journaled for rotation within a seal, the pinion gear engaging the drive gear;
- a chalk-line spool engaging the second shaft for rotation therewith;
- a housing comprising a handle-like portion comprising a first chamber wherein the cartridge is disposed so that the second end of the spring engages a wall of the first chamber;
- a second chamber wherein the spool is disposed;
- and
- means of retaining the seal about the second shaft intermediate the first and the second chambers.
In a chalk-line dispenser comprising a housing holding a chalk-line spool, the spool coupled to a line retracting spring by means comprising a shaft, an improvement comprising a latching brake, the latching brake comprising:
- a first portion rotating with the shaft, the first portion having a non-circular cross-section;
- and
- a trigger attached to the housing for pivotal motion between a latched and a released position, the trigger comprising a flexible portion coacting with the first portion when the trigger is in the latched position, the flexible portion frictionally bearing on the first portion when the trigger is intermediate the latched and the released positions, the flexible portion not coacting with the first portion when the trigger is in the released position.
Dependencies are inferred from the claim text.