Tape measure with finger drag brake

A tape measure has a finger recess in a housing, with at least a portion of the underside of a tape blade exposed in the finger recess. Pressing a finger against the underside of the tape allows the user to create a drag brake that acts against the retraction spring to slow and/or stop the retraction of the tape blade. The finger recess is located upstream (i.e. closer to the coiled portion of the retracted tape blade) than the point at which the tape measure's lock engages the tape blade. This arrangement results in a compact yet versatile overall tape measure with good tactile feedback during finger-braking.

BACKGROUND

“Power-return” tape measures typically employ a mechanical spring to supply a retraction force that urges the tape blade to retract into the housing. Such tape measures typically include a manually actuated lock mechanism to lock the tape blade, once deployed, in the deployed position. Release of the lock mechanism causes the tape blade to retract under the bias of the spring. The speed of retraction may be faster than desired in some situations. As such, some tape measures have been proposed that utilize finger-controlled drag brakes in addition to the locking mechanism. For example, see U.S. Pat. Nos. 7,174,656 and 6,161,299. While such approaches have provided some desired functionality, there remains a need for alternative designs for tape measures that include drag brake functionality.

SUMMARY

A tape measure is described that has a finger recess in a housing, with at least a portion of the underside of a tape blade exposed in the finger recess. Pressing a finger against the underside of the tape allows the user to create a drag brake that acts against the retraction spring to slow and/or stop the retraction of the tape blade. The finger recess is located upstream (i.e. closer to the coiled portion of the retracted tape blade) than the point at which the tape measure's lock engages the tape blade. This arrangement results in a compact yet versatile overall tape measure.

In one embodiment, the present invention provides a tape measure comprising a housing having an exit port and a finger recess. A retraction spring is disposed in the housing. A tape blade having measuring indicia thereon is movably mounted to the housing. The tape blade is moveable between a deployed configuration where the tape blade extends forwardly outward from the housing at the exit port and a retracted configuration where the tape blade is substantially retracted into the housing. The tape blade is biased toward the retracted configuration by the spring. A lock is movably disposed in the housing and movable between an unlocked position in spaced relation to the tape blade and a locked position engaged with an upper surface of the tape blade at a blade engagement location so as to inhibit retraction of the tape blade. The tape blade exits the housing at the exit port in the deployed configuration. A laterally central portion of an underside surface of the tape blade is externally exposed in the finger recess. The exit port is disposed forwardly relative to the blade engagement location. The finger recess is disposed rearwardly relative to the blade engagement location.

Some or all of the embodiments may have the following aspects. An end hook may be slidably mounted to a distal end portion of the tape blade, with the end hook extending through the exit port when the tape blade is in the retracted configuration. The end hook may comprise first and second downwardly extending legs. The lateral edges of the tape blade, for a longitudinal portion of the tape blade disposed in the finger recess, may be protected by the housing so as to be not externally exposed. The tape blade may naturally assume a concavo-convex cross-sectional configuration when deployed from the housing. The tape blade may form a convolute coil on a drum in the retracted configuration, the drum being disposed in the housing and rotatable relative thereto about a rotational axis; wherein the finger recess is disposed forwardly relative to the rotational axis. A portion of tape blade disposed in the finger recess may have a downstream cross-section disposed closer to the exit port and an upstream cross-section disposed farther from the exit port, with the downstream cross-section having a greater height than the upstream cross-section. The housing may comprise a generally planar lower surface that extends forwardly and rearwardly of the finger recess. The housing may comprise lateral sidewalls, and the finger recess may extend across a bottom of the housing and partially along the sidewalls and taper into the sidewalls.

In another embodiment, the present invention provides a method of operating a tape measure. The tape measure includes a housing, a tape blade selectively deployable from the housing, a lock movably disposed in the housing and movable between an unlocked position in spaced relation to the tape blade and a locked position engaged with an upper surface of the tape blade at a blade engagement location so as to inhibit retraction of the tape blade. The housing has a finger recess disposed rearwardly relative to the blade engagement location. The method comprises deploying a portion of the tape blade forwardly from the housing, and thereafter retracting at least a segment of the portion of the tape blade into the housing via a retraction spring while the lock is in the unlocked position. The method includes, during the retracting, pressing a finger upward against a underside surface of the tape blade that is exposed in the finger recess. The pressing a finger upward against the underside surface may comprise pressing the finger against a laterally central portion of a segment of the tape blade while the corresponding lateral edges of the segment are protected by the housing so as to be unexposed. A portion of tape blade disposed in the finger recess may have a downstream cross-section disposed closer to the exit port and an upstream cross-section disposed farther from the exit port; with the downstream cross-section having a greater height than the upstream cross-section. The pressing the finger upward against the underside surface of the tape blade may cause the retracting to stop. The method may continue by removing the finger from the underside surface of the tape blade and fully retracting the tape blade.

Of course, the present invention is not limited to the above features and advantages. Indeed, those skilled in the art will recognize additional features and advantages upon reading the following detailed description, and upon viewing the accompanying drawings. The various aspects discussed above may be used alone or in any combination.

DETAILED DESCRIPTION

In one embodiment, the present application is directed to a tape measure having a finger recess in a housing, with at least a portion of the underside of a tape blade externally exposed in the finger recess. Pressing a finger against the underside of the tape blade allows the user to create a drag brake that acts against the retraction spring to slow and/or stop the retraction of the tape blade. The finger recess is located upstream (i.e., closer to the coiled portion of the retracted tape blade inside the housing) than the point at which the tape measure's lock engages the tape blade. This arrangement results in a compact yet versatile overall tape measure.

Referring toFIG. 1, a tape measure10according to one or more embodiments includes a housing20and a tape blade50selectively deployable from the housing20. The housing20may take any of a variety of shapes known in the art, but advantageously has a generally rectangular shape in side profile, with a front face21, a rear22, a top23, a bottom24, and lateral sidewalls27. The tape blade50extends from the housing20, when deployed, at an exit port38located in the lower portion of the front21. The top23and/or front21advantageously includes a lock actuator opening25that allows a lock actuator82to slide relative to the housing20in a conventional fashion. The housing20may optionally include a clasp extension28, such as at the lower rear corner, for allowing attachment of a clasp such as a carabiner, for hanging the tape measure10when not in use.

The bottom24of the housing20includes a finger recess30. The finger recess30is formed by an upward indention in the bottom24. The lower surface26of the bottom24may advantageously be generally planar, and extend both forward and rearward of the finger recess30, so as to provide a flat surface for standing the tape measure10upright on a work surface. The finger recess30includes an opening32through which the tape blade50is exposed. The opening32has a forward edge34and a rearward edge36, which may have different lateral cross-sectional profiles as discussed further below. The finger recess30advantageously may be configured such that the lateral sides thereof blend into the sidewalls27if desired.

The housing20is advantageously formed of a suitable hard plastic, but any material known in the art may be used. The housing20may optionally include softer plastic overmolding for enhanced feel, as is known in the art. Also, a belt clip44may be mounted the housing20if desired.

A drum40is rotatably mounted in the housing20for rotation about a drum rotational axis41. The drum40provides a means for winding the tape blade50into a convolute coil shape when the tape blade50is retracted into the housing20. The housing20also advantageously includes a suitable post29for anchoring one end of a retraction spring42that supplies a retraction bias to the tape blade50in any known fashion.

The tape blade50is advantageously formed of metal with a polymer coating as is conventional, but any other materials known in the art may alternatively be used. The tape blade50includes suitable length indicia62on an upper surface60thereof to indicate distance along its longitudinal axis, as is conventional. While not required, the tape blade50advantageously has a concavo-convex cross-sectional profile when extended from the housing20. However, the tape blade50advantageously assumes a flattened profile for the portion thereof wound on the drum40. The proximal end portion54of the tape blade50is mounted to the drum40and/or the spring42so as to be moveably anchored inside the housing20. The distal end portion52of the tape blade50is intended to be repeatably deployed from and retracted into the housing20via exit port38. As is conventional, an end hook70may be attached to the distal end portion52of the tape blade50. The end hook70may take any form known in the art. The end hook70typically includes a mounting portion72that extends parallel to the longitudinal axis51of the tape blade50, and a hooking portion74that extends generally perpendicular thereto. In some embodiments, the hooking portion74of the end hook70may have two legs76that extend downward and/or outward. The end hook70may be slidably mounted to the tape blade50by (not shown) rivets that extend through slots78in the mounting portion72, so as facilitate both “inside” and “outside” length measurements. Typically, the mounting portion of the end hook70extends into and through the exit port38when the tape blade50is fully retracted.

The tape blade50is selectively deployable from the housing20. Thus, the tape measure10is changeable from a deployed configuration where the tape blade50extends forwardly from the housing20(with the end hook70spaced from the housing20) for taking measurements to a retracted configuration where the tape blade50is retracted into the housing20(and the end hook70is advantageously abutting the housing20). Because the tape blade50is under a retraction bias from the spring42, a lock mechanism (or simply “lock”)80is provided to allow the tape blade50to be locked in position when deployed. The lock80may take any form known in the art. For example, the lock80may include an actuator82having an externally accessible button83, and a pivotally mounted locking arm84. Movement of the actuator82forward/downward causes the locking arm84to pivot so that it comes in contact with an upper surface60of the tape blade50at a blade engagement location88and presses the tape blade50against the housing20to as to lock the tape blade50in position. Movement of the actuator82rearward/upward causes the locking arm84to pivot so as to move out of engagement with the tape blade50, thereby allowing the spring42to pull the tape blade50backward to the fully retracted position. Regardless of the particular lock structure used, the lock80is movable between a locked position where the lock80is in engagement with the tape blade50at the blade engagement location88and an unlocked position where the lock80is in spaced relation to the tape blade50.

The finger recess30allows the user to apply finger pressure to the tape blade50to either slow down or stop the retraction of the tape blade50when the lock80is in the unlocked position. The tape blade50passes through the finger recess30when moving from the drum40to the exit port38(and then out of housing20). The underside surface64of the tape blade50, for that segment66of the tape blade50in the finger recess30, is exposed due to the opening32in the housing20at the finger recess30. In some embodiments, the finger recess30may be configured so that the entire lateral width of the tape blade50is exposed in the finger recess30. Thus, in some embodiments, the lateral edges58of the segment66of the tape blade50disposed in the finger recess30may be exposed. However, in other embodiments, the lateral edges58of the tape blade50are advantageously protected by the housing20such that only a laterally central portion56of the tape blade50cross-section is externally exposed in the finger recess30, while the lateral edges58are hidden by the housing20. This latter arrangement is believed to help inhibit debris from entering the housing20and potentially adversely affecting the deployment/retraction action of the tape blade50. Further, this latter arrangement is believed to help protect the user's finger(s) from the relatively “sharper” lateral edges58of the tape blade50. It is possible that the tape blade50will have a different cross-sectional profile at the forward portion of the finger recess30than at the rearward portion of the finger recess30. For example, the cross-sectional profile of the tape blade50at the forward edge34of opening32may be more curved so as to have greater height H than the cross-sectional profile of the tape blade50at the rearward edge36of opening32(seeFIGS. 6-7). Advantageously, the contour of the opening32likewise differently shaped at the forward edge34and the rearward edge36to match this difference in cross-sectional profile of the tape blade50.

From the fully retracted configuration and the lock80in the unlocked position, the user may deploy the tape blade50to a first long desired length, and optionally lock the tape blade50in position and take a measurement. The user may then release the lock40if locked, and allow the tape blade50to start retraction. The user presses their finger upward against the exposed underside surface64of tape blade50in the finger recess30, advantageously against the laterally central portion56, to apply a finger-braking action that slows down or stops the retraction. The finger-braking action, or retardation force, is a result of frictional drag of the user's finger against the underside surface64of the tape blade50in the finger recess30. Because the finger-braking action is due to the direct contact of the user's finger against the tape blade50, the user is provided with good tactile feel of the braking action. Advantageously, the finger-breaking is achieved without pressing the laterally central portion56of tape blade50against a support internal to the housing20, so that the good tactile feel is maintained. Further, the finger-breaking advantageously does not distort the tape blade50so as to breakback/buckle the tape blade50. Release of the finger pressure allows the retardation force to be removed. Thus, a user is able to control the tape blade50retraction via application of finger force against the underside surface64of the tape blade50at the finger recess30.

It should be noted that the finger recess30is located behind (or “upstream”) of the tape exit port38where the tape blade50exits the housing20. Indeed, the finger recess30is spaced rearward from the exit port38so that the housing20may provide a suitable stopping surface to stop the end hook70when the tape blade50is fully retracted. Further, the location of the finger recess30corresponds to a natural location for the user's finger when holding the tape measure10. In addition, this configuration allows the blade engagement location88associated with the lock80to be located forward of the finger recess30, allowing for compact yet versatile overall tape measure10. In most embodiments, the configuration of the opening32and finger recess30allows for use of a tape blade50with relatively high natural cross-sectional height (high concavity).

In some embodiments, the housing20may optionally include a tape blade wiping feature proximate forward edge34and/or rearward edge36of opening32, to help inhibit dirt infiltration. The wiping feature may take any suitable form, such as a foam and/or elastomeric material, a curved ridge on the housing that acts as a scraping blade against the tape blade, or the like.

In some embodiments, one or more lights (e.g., LED's) may be disposed in the housing20so as to shine forwardly or forwardly/downwardly when energized. Such lights (not shown) may be powered by any known means (e.g., battery, wind-up mechanism, capacitor(s), etc.) and controlled via a suitable switch.

Additional information about optional configurations relating to post29may be found in U.S. Pat. No. 6,718,649 and U.S. Pat. No. 7,458,537. Additional information about optional configurations relating to spring42may be found in U.S. Pat. No. 6,718,649. Additional information about optional configurations relating to end hook70may be found in U.S. Pat. No. 5,010,657 and U.S. Pat. No. 7,240,439. Additional information about optional configurations relating to tape blade50may be found in U.S. Patent Application Publication No. 2004/0071869. The disclosures of these U.S. patents and patent application publications are hereby incorporated herein by reference in their entirety.