A length measuring device and a length measuring system are provided, in which the length measuring device includes a casing, a first rotating portion accommodated in the casing, and rotated with a portion of a circumference thereof being exposed out of the casing and in contact with an object to be measured, a first sensing portion which senses an amount of rotation of the first rotating portion, and a controller which converts the amount of rotation of the first rotating portion into length measurement. Additionally, the length measuring device may further include a second rotating portion coiled with a strip by a plurality of times, and rotated according to the strip being withdrawn or retracted through an outlet formed in the casing, and a second sensing portion which senses an amount of rotation of the second rotating portion, in which the controller may convert the amount of rotation of the second rotating portion into length measurement.

According to an embodiment, a tape measure comprises an accessory removably coupleable to either side of the housing. According to another embodiment, a tape measure comprises an accessory removably coupleable to the housing via a locking mechanism that holds the accessory at a plurality of desired orientations. According to another embodiment, a tape measure comprises a slide lock, where movement of the slide lock from a locked position into an unlocked position requires depression of the actuator towards the interior of the housing. According to another embodiment, a motor assembly for a tape measure comprises a backer plate, a motor body, and a spring, where a bond is applied therebetween. According to another embodiment, a motor assembly for a tape measure comprises a motor body and a spring, where one of a metallurgical bond or an adhesive is applied between the motor body and the spring.

A tool, such as a tape measure, including a spring-based retraction system is shown. The retraction system utilizes an epicyclic gear train coupled between the tape blade winding reel and a rotating arbor or axle within the tape measure. A spiral spring has an outer end coupled to the reel and an inner end coupled to the axle. The gear train may be a reduction gear train such that the axle rotates slower than the reel. By coupling the spiral spring between the gear train input and gear train output, high energy density springs may be used, which may allow for decrease in housing size, increase in tape length or thickness for a given housing size, and/or advantageous retraction speed control.

A tape rule assembly includes differential spring-drive systems for rotating a reel of tape through an angular distance different from the angular distance traveled by a hub carrying a wound spring, relative to the tape rule housing. The differential spring drive systems include planetary and cycloidal drive systems. The tape rules of the present invention are thus made more compact than conventional tape rules.

A tool, such as a tape measure, including a spring-based retraction system is shown. The retraction system utilizes an epicyclic gear train coupled between the tape blade winding reel and a rotating arbor or axle within the tape measure. A spiral spring has an outer end coupled to the reel and an inner end coupled to the axle. The gear train may be a reduction gear train such that the axle rotates slower than the reel. By coupling the spiral spring between the gear train input and gear train output, high energy density springs may be used, which may allow for decrease in housing size, increase in tape length or thickness for a given housing size, and/or advantageous retraction speed control.

A tool, such as a tape measure, including a spring-based retraction system is shown. The tape measure includes a fluid-based retraction speed controller. The speed controller may be formed from a rotor/stator arrangement. The rotor is coupled to the reel and the stator is coupled to the housing opposing the rotor. The rotor converts some rotational energy from tape reel into movement of a fluid (e.g., movement of air, movement of oil, etc. through friction) which acts to slow or limit the retraction/rotational speed of the reel as the retraction spring expands driving the reel during tape blade retraction.

A tool, such as a tape measure, including a spring-based retraction system is shown. The retraction system utilizes an epicyclic gear train coupled between the tape blade winding reel and a rotating arbor or axle within the tape measure. A spiral spring has an outer end coupled to the reel and an inner end coupled to the axle. The gear train may be a reduction gear train such that the axle rotates slower than the reel. By coupling the spiral spring between the gear train input and gear train output, high energy density springs may be used, which may allow for decrease in housing size, increase in tape length or thickness for a given housing size, and/or advantageous retraction speed control.

According to an embodiment, a tape measure comprises an accessory removably coupleable to either side of the housing. According to another embodiment, a tape measure comprises an accessory removably coupleable to the housing via a locking mechanism that holds the accessory at a plurality of desired orientations. According to another embodiment, a tape measure comprises a slide lock, where movement of the slide lock from a locked position into an unlocked position requires depression of the actuator towards the interior of the housing. According to another embodiment, a motor assembly for a tape measure comprises a backer plate, a motor body, and a spring, where a bond is applied therebetween. According to another embodiment, a motor assembly for a tape measure comprises a motor body and a spring, where one of a metallurgical bond or an adhesive is applied between the motor body and the spring.

Provided is a length measuring device having an automatic zero point adjusting function and a control method thereof. The length measuring device includes a line to which a hook part is attached at one end, a case having an opening formed therein, a rotating part to be rotated according to extraction or retraction of the line out of or into the case through the opening, a rotation sensing part which senses a rotation of the rotating part, and a control part which converts an amount of rotation of the rotating part into a length measurement value and resets the converted length measurement value to a predetermined value when the length measuring device is in a first state.

A laser tape measure device has a casing comprised of a first housing and a second housing. A laser ranging device is arranged toward and is attached to the first housing. An upper interior plate is arranged between the first housing and the second housing, and is attached to the second housing to form a chamber for the laser ranging device. A tapeline structure is arranged toward and fastened to the second housing and includes a tapeline wheel upon which a measuring tape is wound. A lower interior plate is attached to and covers only the bottom of the tapeline wheel and forms a lower part of a tapeline cavity. No portion of the upper interior plate extends into the tapeline cavity and no portion of the lower interior plate extends into an upper part of the tapeline cavity.