Patent Description:
Tape measures are measurement tools used for a variety of measurement applications, including in the building and construction trades. Some tape measures include a graduated, marked blade wound on a reel and also include a retraction system for automatically retracting the blade onto the reel. In some typical tape measure designs, the retraction system is driven by a coil or spiral spring that is tensioned, storing energy as the tape is extended, and that releases energy to spin the reel, winding the blade back onto the reel.

<CIT> discloses a winding and reeling device for an elongated, flexible member. A reel is connected to the outer end of a spiral spring. The outer end of the spiral spring is rigidly connected to the reel, whereby a gear is connected between the outer and the inner end of the spiral spring such that upon rotation of the outer end of the spiral spring around its center axis the inner end of the spiral spring rotates around the same axis, however at a slower rotational speed. The reel has smooth surfaces and comprises at no place any gear teeth. A rotation of the reel causes the rotation of the gear wheels of the gear, whereby two gear wheels having a different number of teeth are rigidly connected to each other and arranged on a common shaft. A further shaft is provided which carries two further gear wheels, whereby one gear wheel is rigidly connected to the further shaft and the other gear wheel is freely rotatable on said further shaft. The gear is a speed reduction gear, whereby its input end is driven by the reel and its output end drives the inner end of the spiral spring.

<CIT> discloses a structure of automatic return band tape for reducing a ruler shell, lightening the weight and lengthening the ruler tape. The structure of the band tape includes: a ruler shell, a winding drum mounted in the ruler shell, a ruler strip winded around the winding drum, a winding device mounted in the winding drum, a rotation shaft penetrating the winding device, a base plate mounted on the side of the winding device, a pinion mounted on the center of the base plate; the turbination spring mounted in the said winding wheel, the inner ring teeth are mounted on the side of winding wheel, the gear cluster are mounted on the base plate, and joggling with said inner ring teeth, the additional pinion is also joggled with the gear cluster and driven by the rotation shaft or winding drum to drive the gear cluster to drive the winding wheel to crinkle the turbination spring.

<CIT> discloses a system having a band under a spring action which is achieved through a gearbox. It works in combination by sitting in between a housing containing a turnable arranged spool to wind the band. A spring can be pulled. If the band is released the spring is tensioned by the spool. One end of the spring is interconnected with the spool. The other end of the spring is connected to a spline gear wheel of the gearbox.

Aspects of the invention are defined in the claims listed at the end of this specification.

Additional features and advantages will be set forth in the detailed description which follows, and, in part, will be readily apparent to those skilled in the art from the description or recognized by practicing the embodiments as described in the written description and claims hereof, as well as the appended drawings. It is to be understood that both the foregoing general description and the following detailed description are exemplary.

The accompanying drawings are included to provide further understanding and are incorporated in and constitute a part of this specification. The drawings illustrate one or more embodiments and, together with the description, serve to explain principles and operation of the various embodiments.

The embodiments of <FIG> and <FIG> are not claimed as such.

Referring generally to the figures, various embodiments of a tape measure are shown. Various embodiments of the tape measure discussed herein include an innovative retraction system designed to provide for a variety of desired retraction characteristics, including controlled/reduced retraction speed. Some tape measure blades are susceptible to damage/breakage due to high speed during retraction. For example, high speeds during retraction may cause the tape blade to whip (e.g., the tendency of the tape measure blade to bend or snap back on itself during fast retraction), which can crack or tear the tape blade, and similarly, high retraction speeds can damage the tape blade when the tape hook contacts the tape housing at the end of retraction. Applicant believes that the tape measure retraction system described herein provides for retraction speed control that can limit such sources of tape measure damage while at the same time providing a more compact tape measure without sacrificing tape length or retraction performance.

As will generally be understood, in certain tape measure designs, a spring stores energy during tape blade extension and applies a force/torque to a reel causing the tape blade to wind on to the reel during tape blade retraction. Various aspects of spring design, such as spring energy, torque profile, spring constant, etc., are selected to ensure that operation of the spring has enough energy to provide satisfactory tape retraction. However, because of the physics and characteristics of the typical tape measure spiral spring, in order to ensure full tape retraction at a satisfactory speed, the typical tape measure spiral spring delivers excess energy to the tape blade during retraction, which in turn translates into undesirably highly retraction speeds and whip, particularly toward the end of retraction. In addition, for a given spiral spring design increasing spring energy to provide for retraction of longer, wider and/or thicker measuring tape blades typically requires use of a larger spiral spring, which in turn results in a larger tape measure.

As discussed herein, Applicant has developed various innovative tape measure blade retraction systems that provide a desired level of spring energy while utilizing a relatively short or small volume spring, while maintaining a relatively small tape measure housing (e.g., a tape measure outer diameter) and/or while providing desired retraction characteristics. As discussed in more detail, the tape retraction system discussed herein utilizes a gear train having its input coupled to a rotating tape reel, the output coupled to a rotating central arbor or axle, and one portion coupled to a stationary tape measure housing. The tape retraction system also includes a spring, such as a spiral spring, coupled at its inner end to the rotating axle and at its outer end to the rotating tape reel. In general, the gear train is a reduction gear train that translates each rotation of the tape reel to less than one rotation of the axle, and both the tape reel and the axle rotate together during tape extension and retraction.

As compared to a gear reduction arrangement in which the input of a gear train is coupled to the tape reel and the output of the gear train is coupled to the outer end of the spiral spring, the gear train arrangement discussed herein provides for space savings within the reel, which can be utilized to further decrease spring size, allowing housing size to be decreased. Alternatively, the space savings provided by the retraction system arrangements discussed herein can be utilized to increase spring energy for a fixed housing size, which allows for a longer tape blade to be deployed within a smaller tape housing than would typically be needed to accommodate the longer tape length. As will be understood from the description below, the gear train operates in one direction during tape measure extension as the reel drives winding of the spiral spring, and the gear train operates in the opposite direction during tape measure retraction as the expanding spiral spring drives rotation of the reel and tape blade uptake. As used herein, the directionality of the gear train (e.g., input and output) refers to operation of the gear train during tape extension, with the understanding that the gear train operates in the opposite direction during tape blade retraction.

Referring to <FIG>, a length measurement device, tape measure, measuring tape, retractable rule, etc., such as tape measure <NUM>, is shown according to an exemplary embodiment. In general, tape measure <NUM> includes a housing <NUM> having a first part <NUM> and a second part <NUM>. Tape measure <NUM> includes a tape blade <NUM> and, in the retracted position shown in <FIG>, tape blade <NUM> is wound or coiled onto a tape reel <NUM>. In general, tape blade <NUM> is an elongated strip of material including a plurality of graduated measurement markings, and in specific embodiments, tape blade <NUM> is an elongated strip of metal material (e.g., steel material) that includes an outer most end coupled to a hook assembly <NUM>. Tape blade <NUM> may include various coatings (e.g., polymer coating layers) to help protect tape blade <NUM> and/or the graduated markings of the blade from wear, breakage, etc..

In general, tape reel <NUM> is rotatably mounted within housing <NUM> and positioned around an axle <NUM>. As will be explained in more detail below, axle <NUM> is rotatably mounted within housing <NUM> such that axle <NUM> is allowed to rotate relative to housing <NUM> during tape extension or retraction.

As shown schematically in <FIG>, tape measure <NUM> includes a retraction system <NUM> that includes a spring, shown as spiral spring <NUM>. In general, spiral spring <NUM> is coupled between axle <NUM> and tape reel <NUM> (or through tape reel <NUM> to directly couple to an inner end of tape <NUM>) such that spiral spring <NUM> is coiled or wound to store energy during extension of tape <NUM> from housing <NUM> and is unwound, releasing energy, driving rewinding of tape <NUM> onto tape reel <NUM> during retraction of tape <NUM> (e.g., following release or unlocking of the tape <NUM>). Specifically, when tape blade <NUM> is unlocked or released, spring <NUM> expands, driving tape reel <NUM> to wind up tape blade <NUM> and to pull tape blade <NUM> back into housing <NUM>.

As shown in <FIG>, the non-extended portion of tape <NUM> is wound onto a reel <NUM>, which is surrounded by housing <NUM>. Reel <NUM> is rotatably disposed about an axis <NUM> of tape measure <NUM>, and spring <NUM> is coupled to reel <NUM> and configured to drive reel <NUM> about rotation axis <NUM>, which in turn provides powered retraction of tape blade <NUM>. Referring to <FIG>, a tape lock <NUM> is provided to selectively engage tape blade <NUM>, which acts to hold tape blade <NUM> and reel <NUM> in place such that an extended segment of tape blade <NUM> remains at a desired length.

A slot <NUM> is defined along a forward portion of housing <NUM>. Slot <NUM> provides an opening in the tape measure housing <NUM>, which allows tape lock <NUM> to extend into housing <NUM> and to engage with tape <NUM> or reel <NUM>. In addition, slot <NUM> provides a length sufficient to allow tape lock <NUM> to be moved relative to housing <NUM> between locked and unlocked positions. Below slot <NUM>, a tape port <NUM> is provided in tape housing <NUM>. In one embodiment, tape port <NUM> has an arcuate shape, corresponding to an arcuate cross-sectional profile of tape blade <NUM>. Tape port <NUM> allows for the retraction and extension of tape blade <NUM> into and from housing <NUM> during tape extension and retraction.

Referring to <FIG>, a schematic view of tape measure <NUM> including retraction system <NUM> is shown. In general, retraction system <NUM> includes a gear train <NUM>. Gear train <NUM> includes an input <NUM> that is coupled to tape reel <NUM> and an output <NUM> that is coupled to rotating axle <NUM>. In particular embodiments, gear train <NUM> is a reduction gear train that provides gear reduction between tape reel <NUM> and axle <NUM> such that for each rotation of tape reel <NUM> (e.g., during tape extension), axle <NUM> experiences less than one rotation. In specific embodiments, the gear reduction provided by gear train <NUM> is at least <NUM> reel turns to <NUM> axle turns (<NUM>/<NUM>), specifically at least <NUM> reel turns to <NUM> axle turns (<NUM>/<NUM>), and more specifically at least <NUM> reel turns to <NUM> axle turns (<NUM>/<NUM>). In a specific embodiment, gear train <NUM> provides a gear reduction of <NUM> reel turns to <NUM> axle turns (<NUM>/<NUM>).

In specific embodiments, both reel <NUM> and axle <NUM> are rotating in the same direction, which in turn causes the inner end of spring <NUM> (coupled to axle <NUM>) and the outer end of spring <NUM> (coupled to reel <NUM>) to rotate in the same direction as each other. Thus, by coupling spring <NUM> between two rotating portions of retraction system <NUM>, the number of turns that spring <NUM> experiences per rotation of reel <NUM> is substantially greater than the number of rotations axle <NUM> experiences per rotation of reel <NUM>. As will be understood, while the specifics of the gear reduction calculation will vary based on the specific gear arrangement used, the following formula defines the spring turn ratio of the various gear trains discussed herein: <MAT>.

In this manner, by providing gear reduction between tape reel <NUM> and axle <NUM>, and by locating spring <NUM> between the rotating input and output of gear train <NUM>, the number of turns spring <NUM> experiences for each rotation of reel <NUM> can be decreased by utilizing a gear train with a relatively low gear ratio. By decreasing the number of turns of spring <NUM> (as compared to a standard spiral spring) needed to achieve full extension of tape blade <NUM> from reel <NUM>, spring <NUM> can be formed from stiffer material that is more energy dense (spring energy stored per unit volume occupied by the spring) than a spring compliant enough to experience a high number of turns. In specific embodiments, gear train <NUM> is configured such that the Spring Turn Ratio is greater than <NUM>, is between <NUM> to <NUM>, is between <NUM> to <NUM>, is between <NUM> to <NUM>, is between <NUM> to <NUM>, is between <NUM> to <NUM> or is between <NUM> to <NUM>. In one specific embodiment, the Spring Turn Ratio of gear train <NUM> is <NUM> to <NUM>, and in another specific embodiment, the Spring Turn Ratio of gear train <NUM> is between <NUM> and <NUM>, and specifically is <NUM>. In additional specific embodiments, gear train <NUM> is configured such that the ratio of rotations of reel <NUM> to the rotations of axle <NUM> is between <NUM> to <NUM>, is between <NUM> to <NUM>, is between <NUM> to <NUM> (this embodiment correlates to the embodiment of gear train <NUM> with a Spring Turn Ratio between <NUM> to <NUM>), is between <NUM> to <NUM> or is between <NUM> to <NUM>. Applicant believes that retraction control systems having ratios within these ranges generally provide satisfactory torque profiles and spring sizes for tape measure applications.

Thus, retraction system <NUM> allows for a desired level of torque/energy to be delivered by spiral spring <NUM> while decreasing the total volume of spiral spring <NUM> (e.g., reducing width or length of spring <NUM>). In specific embodiments, by reducing the total length of spiral spring <NUM>, the diameter of spiral spring <NUM> can be reduced as compared to a tape measure retraction system with the same torque/energy needs but does not utilize gear reduction as discussed herein. Further, by utilizing retraction system <NUM> with the gear train arrangements discussed herein, spring <NUM> is coupled at its outer end directly to reel <NUM>, which eliminates the need for additional transmission elements to be located within reel <NUM> to effect the coupling between the spring and the gear system. This extra volume can be used for additional spring size or for additional tape length while maintaining a selected outer tape measure housing.

In general as noted above, using a thicker spring increases torque while reducing the number of turns applied to the spring to achieve a particular level of energy stored within the spring. Thus, by utilizing a reduction gear drive, such as gear train <NUM>, a smaller, more compact spring can be used by taking advantage of the increased power density of the lower turn spring. In specific embodiments, spring <NUM> and gear train <NUM> are configured to deliver a preload torque of <NUM>-<NUM> (<NUM> - <NUM> in-lbf), and specifically of <NUM>-<NUM> (<NUM> - <NUM> in-lbf), and a maximum torque reacting between reel <NUM> and axle <NUM> of <NUM>-<NUM> (<NUM> - <NUM> in-lbf), and specifically of <NUM>-<NUM> (<NUM> - <NUM> in-lbf). Referring to <FIG>, the effect on preload torque of various gear ratios is shown for an exemplary tape measure and spring having the following characteristics:. <NUM> spring thickness, <NUM> tape housing inner diameter and <NUM> operating turns. As shown in <FIG>, preload torque decreases as spring turn ratio increases. Given a desired target preload torque of between <NUM> -<NUM> (<NUM> - <NUM> in-lbf), a spring turn ratio of between about <NUM>:<NUM> to <NUM>:<NUM> is desirable for the given spring and tape housing shown in <FIG>.

As will be understood, the retraction speed delivered to reel <NUM> is related to the torque and energy supplied by spring <NUM> and gear train <NUM> to reel <NUM> during retraction. In specific embodiments, spring <NUM> and gear train <NUM> are configured to deliver a desired rotation speed to reel <NUM> during retraction of between <NUM> rpm to <NUM> rpm, specifically of <NUM> rpm to <NUM> rpm and more specifically of between <NUM> rpm to <NUM> rpm.

Retraction system <NUM> also includes a fixed, rigid connection <NUM> coupling gear train <NUM> to housing <NUM>. As will be generally understood, one component of gear train <NUM> is coupled to housing <NUM> via connection <NUM>, which allows for the rotation transfer and gear reduction from input <NUM> to output <NUM> of gear train <NUM>. As will be discussed in detail below, which gear train components are coupled to reel <NUM>, to axle <NUM> and to housing <NUM> through connection <NUM> will vary based on the particular gear train design used. However, as noted above, in various embodiments, a rotatable component of gear train <NUM> is coupled to reel <NUM> such that rotation of reel <NUM> is transferred to gear train <NUM> and a rotatable component of gear train <NUM> is coupled to axle <NUM> such that rotation of reel <NUM> is transferred through gear train <NUM> to axle <NUM>.

In various embodiments, gear train <NUM> may be any one of a variety of epicyclic gear train designs. In specific embodiments, gear train <NUM> is any one of the gear arrangements shown and described in ANSI/AGMA <NUM>-B06. In other embodiments, gear train <NUM> includes two or more epicyclic gear arrangements connected to each in series in which the input of a first epicyclic gear arrangement is coupled to reel <NUM>, the output of the first epicyclic gear arrangement is coupled to the input of a second gear arrangement, and the output of the second epicyclic gear arrangement is coupled to axle <NUM>. This pattern can be repeated for gear trains <NUM> that include, <NUM>, <NUM>, <NUM>, etc. epicyclic gear trains in series. In other embodiments, gear train <NUM> is a gear arrangement not described in ANSI/AGMA <NUM>-B06. As will be understood, utilizing some epicyclic gear arrangements in which the input of the gear train is coupled to reel <NUM>, the output is coupled to axle <NUM> and spring <NUM> is coupled between reel <NUM> and axle <NUM>, spring <NUM> is wound in the same direction as rotation of reel <NUM> during tape extension, and in other embodiments, spring <NUM> is wound in the opposite direction of rotation of reel <NUM> during tape extension.

While Applicant generally understands that a wide variety of epicyclic gear train arrangement may be implemented as gear train <NUM> discussed above, Applicant believes that certain gear train arrangements provide for efficient space use within tape housing <NUM>, low complexity, desirable torque characteristics, etc. Specific exemplary embodiments of such gear trains are shown in <FIG> and <FIG>.

Referring to <FIG>, in a specific embodiment, gear train <NUM> may be a planetary gear train <NUM>. Planetary gear train <NUM> includes a central or sun gear <NUM>, an outer ring gear <NUM>, a gear carrier <NUM> and at least two planetary gears <NUM>.

As shown in <FIG>, sun gear <NUM> is rigidly coupled to tape housing <NUM> and provides fixed connection <NUM> between planetary gear train <NUM> and housing <NUM>. Sun gear <NUM> defines an axis of rotation of gear train <NUM> that is co-linear with rotation axis <NUM> of tape measure <NUM>. In the specific embodiment shown, sun gear <NUM> is a gear structure that extends inward from an inner surface of tape housing <NUM>. In one embodiment, sun gear <NUM> is a structure that is integrally formed or molded with a component of housing <NUM>, and in another embodiment, sun gear <NUM> is a separate piece coupled (e.g., through an adhesive, weld, friction fit, etc.) to the inner surface of housing <NUM>.

Outer ring gear <NUM> is rigidly coupled to reel <NUM>. As shown in <FIG>, outer ring gear <NUM> is formed on an annular flange <NUM> that extends outward from reel <NUM>. As will be understood (see <FIG>), outer ring gear <NUM> includes gear teeth extending radially inward from an inner, generally cylindrical surface of annular flange <NUM> such that outer ring gear <NUM> surrounds rotation axis <NUM>. In some embodiments, outer ring gear <NUM> and reel <NUM> are integrally formed or molded from a single, contiguous and continuous piece of material, and in another embodiment, outer ring gear <NUM> is a separate piece coupled (e.g., through an adhesive, weld, friction fit, etc.) to an outer surface of reel <NUM>.

Planetary gears <NUM> are mounted to posts <NUM> of gear carrier <NUM>. Gear carrier <NUM> is rigidly (e.g., non-rotationally) coupled to axle <NUM>. The gear teeth of planetary gears <NUM> interface with gear teeth of outer ring gear <NUM> and with the gear teeth of fixed sun gear <NUM>. In this arrangement, as reel <NUM> rotates during tape extension, the interface between outer ring gear <NUM> and planetary gears <NUM> translates rotational motion of reel <NUM> to planetary gears <NUM>. Through the engagement between planetary gears <NUM> and sun gear <NUM>, planetary gears "orbit" around sun gear <NUM> which, in turn translates the orbital movement of planetary gears <NUM> to gear carrier <NUM> and to axle <NUM>. In the specific embodiment shown in <FIG>, planetary gear train <NUM> results in rotation of axle <NUM> in the same direction as reel <NUM>, such that spiral structure of spring <NUM> is coiled in the same direction as tape <NUM> on reel <NUM>.

As will be understood, the relative sizing of sun gear <NUM>, ring gear <NUM> and planetary gears <NUM> dictates the gear reduction between reel <NUM> and axle <NUM>. Thus, this relative sizing of gear train components dictates the spring turn ratio (see Equation <NUM> above) for planetary gear train <NUM>.

Referring to <FIG>, in addition to the increased spring energy density and the resulting space savings within housing <NUM> provided by the gear reduction of planetary gear train <NUM>, the arrangement of planetary gear train <NUM> relative to spring <NUM> and reel <NUM> shown in <FIG> provides further space savings. In particular, in the embodiment of <FIG>, spring <NUM> is coupled directly between reel <NUM> and axle <NUM>, which allows spring <NUM> to be sized to fill the entire cross-sectional diameter of internal chamber <NUM> of reel <NUM>. Thus, in such embodiments, the outermost coil of spring <NUM> faces the inner cylindrical surface of reel <NUM> without a component of planetary gear train <NUM> located between spring <NUM> and reel <NUM>. In addition, compared to some epicyclic gear arrangements, planetary gear train <NUM> further provides for a relatively low number of moving components. Also, planetary gear train <NUM> only results in a relatively minor addition to tape measure width as only one layer of gearing is arranged in the width direction between housing <NUM> and reel <NUM>/axle <NUM>.

Referring to <FIG>, tape measure <NUM> may include a gear train, shown as gear train <NUM>. Gear train <NUM> is an exemplary embodiment of gear train <NUM> discussed above regarding <FIG>. In this embodiment, gear train <NUM> includes a pair of opposing planetary gear trains <NUM>. In the embodiment shown in <FIG>, one planetary gear train <NUM> is located on one side of reel <NUM> and a second planetary gear train <NUM> is located on the other side of reel <NUM>. In this arrangement, spring <NUM> is located within reel <NUM> and located between the two opposing planetary gear trains <NUM> along axis of rotation <NUM>.

Referring to <FIG>, tape measure <NUM> may include a gear train, shown as gear train <NUM>. Gear train <NUM> is an exemplary embodiment of gear train <NUM> discussed above regarding <FIG>. As shown, gear train <NUM> is an epicyclic gear train and includes an outer ring gear <NUM>, an inner ring gear <NUM> and at least two planetary gears <NUM>.

Outer ring gear <NUM> is rigidly coupled to reel <NUM>. As shown in <FIG>, outer ring gear <NUM> is located on annular flange <NUM> that extends outward from reel <NUM>. As will be understood (see <FIG>), outer ring gear <NUM> includes gear teeth extending radially inward from an inner, generally cylindrical surface of annular flange <NUM>. In some embodiments, outer ring gear <NUM> and reel <NUM> are integrally formed or molded from a single, contiguous and continuous piece of material, and in another embodiment, outer ring gear <NUM> is a separate piece coupled (e.g., through an adhesive, weld, friction fit, etc.) to an outer surface of reel <NUM>.

Each planetary gear <NUM> is rotationally mounted to posts <NUM> that are rigidly coupled to the inner surface of housing <NUM>. Posts <NUM> are rigidly coupled to tape housing <NUM> such that planetary gears <NUM> are prevented from translating relative to housing <NUM> but are permitted to spin or rotated about posts <NUM> to translate rotation to axle <NUM>. In this manner, posts <NUM> provide the fixed connection (see connection <NUM> in <FIG>) between gear train <NUM> and housing <NUM>.

Each planetary gear <NUM> includes an outer or high gear section <NUM> and an inner or low gear section <NUM>. Inner ring gear <NUM> is rigidly coupled axle <NUM> through plate <NUM>. In some embodiments, inner ring gear <NUM> and/or plate <NUM> are integrally formed or molded from a single, contiguous and continuous piece of material with axle <NUM>, and in another embodiment, inner ring gear <NUM> and/or plate <NUM> are separate pieces coupled (e.g., through an adhesive, weld, friction fit, etc.) to axle <NUM>.

In operation during tape extension, outer ring gear <NUM> engages high gear section <NUM> of each planetary gear <NUM> such that rotation of reel <NUM> translates into rotation of each planetary gear <NUM> about its post <NUM>. Low gear section <NUM> of each planetary gear <NUM> engages inner ring gear <NUM> such that rotation of the planetary gears <NUM> translates into rotation of inner ring gear <NUM>. Through the rigid coupling between inner ring gear <NUM> and axle <NUM>, the rotation of inner ring gear <NUM> causes rotation of axle <NUM>. In the specific embodiment shown in <FIG>, gear train <NUM> results in rotation of axle <NUM> in the same direction as reel <NUM>, such that spiral structure spring <NUM> is coiled in the same direction as tape <NUM> on reel <NUM>.

Referring to <FIG>, tape measure <NUM> may include a gear train, shown as gear train <NUM>. Gear train <NUM> is an exemplary embodiment of gear train <NUM> discussed above regarding <FIG>. As shown, gear train <NUM> is an epicyclic gear train and includes a small sun gear <NUM>, a large sun gear <NUM> and at least two planetary gears <NUM>.

As shown in <FIG>, small sun gear <NUM> is rigidly coupled to tape housing <NUM> and provides fixed connection <NUM> (see <FIG>) between gear train <NUM> and housing <NUM>. In the specific embodiment shown, small sun gear <NUM> is a gear structure that extends inward from an inner surface of tape housing <NUM>. In one embodiment, small sun gear <NUM> is a structure that is integrally formed or molded with a component of housing <NUM>, and in another embodiment, sun small gear <NUM> is a separate piece coupled (e.g., through an adhesive, weld, friction fit, etc.) to the inner surface of housing <NUM>.

As shown in <FIG>, large sun gear <NUM> is rigidly coupled to axle <NUM> and has an outer diameter greater than that of small sun gear <NUM>. In the specific embodiment shown, large gear <NUM> is a gear structure that extends outward from one of the outer ends of axle <NUM> in the direction of rotation axis <NUM>. In one embodiment, large sun gear <NUM> is a structure that is integrally formed or molded with the end of axle <NUM>, and in another embodiment, large sun gear <NUM> is a separate piece coupled (e.g., through an adhesive, weld, friction fit, etc.) to the end of axle <NUM>.

Gear train <NUM> includes at least two planetary gears <NUM> that are mounted to posts <NUM>. Posts <NUM> extend outward in a direction parallel to rotational axis <NUM> from outer lateral surfaces of reel <NUM>. In this manner, posts <NUM> couple planetary gears <NUM> to reel <NUM>.

Each planetary gear <NUM> includes an outer or high gear section <NUM> and an inner or low gear section <NUM>. As shown in <FIG>, the outer diameter of each high gear section <NUM> is greater than the outer diameter of low gear section <NUM>. The gear teeth of high gear section <NUM> engage with small sun gear <NUM>, and the gear teeth of low gear section <NUM> engage with large sun gear <NUM>.

The coupling between reel <NUM> and planetary gears <NUM> through posts <NUM> carries planetary gears <NUM> around small sun gear <NUM> during tape extension. The engagement between low gear section <NUM> and large sun gear <NUM> drives rotation of axle <NUM> as planetary gears <NUM> rotate or orbit around small sun gear <NUM>. In the specific embodiment shown in <FIG>, gear train <NUM> results in rotation of axle <NUM> in the same direction as reel <NUM>, such that spiral structure spring <NUM> is coiled in the same direction as tape <NUM> on reel <NUM>.

Referring to <FIG>, tape measure <NUM> may include a gear train, shown as gear train <NUM>. Gear train <NUM> is an exemplary embodiment of gear train <NUM> discussed above regarding <FIG>. Gear train <NUM> is similar to gear train <NUM> shown in <FIG> except as discussed herein. As shown, gear train <NUM> is an epicyclic gear train and includes a central or sun gear <NUM>, an outer ring gear <NUM>, a gear carrier <NUM> and at least two planetary gears <NUM>.

Each planetary gear <NUM> includes an outer or high gear section <NUM> and an inner or low gear section <NUM>. Planetary gears <NUM> are mounted to posts <NUM> of gear carrier <NUM>. The gear teeth of low gear section <NUM> of planetary gears <NUM> interface with gear teeth of outer ring gear <NUM>. The gear teeth of high gear section <NUM> of planetary gears <NUM> interface with the gear teeth of fixed sun gear <NUM>. In this arrangement, as reel <NUM> rotates during tape extension, the interface between outer ring gear <NUM> and the gear teeth of low gear section <NUM> of planetary gears <NUM> translates rotational motion of reel <NUM> to planetary gears <NUM>. Through the engagement between planetary gears <NUM> and sun gear <NUM>, planetary gears <NUM> "orbit" around sun gear <NUM>, which in turn translates the orbit movement to gear carrier <NUM> and axle <NUM>. In the specific embodiment shown in <FIG>, gear train <NUM> results in rotation of axle <NUM> in the same direction as reel <NUM>, such that spiral structure spring <NUM> is coiled in the same direction as tape <NUM> on reel <NUM>.

<FIG> show tape measure <NUM> including various epicyclic gear train arrangements according to additional exemplary embodiments. In general the gear train arrangements shown in <FIG> are similar to those discussed above, in that they provide gear reduction between the reel and the axle such that the number of turns applied to the spring per reel revolution is decreased.

Referring to <FIG>, gear carrier <NUM> is coupled to housing <NUM> and includes posts <NUM>, around which inner planetary gear <NUM> and outer planetary gear <NUM> are rotatably mounted. The gear teeth of outer planetary gear <NUM> interface with outer ring gear <NUM> and inner planetary gear <NUM>, the gear teeth of which also interface with inner ring gear <NUM>. Outer ring gear <NUM> is coupled to axle <NUM>, inner ring gear <NUM> is coupled tape reel <NUM>, and spring <NUM> is coupled between tape reel <NUM> and axle <NUM>.

Referring to <FIG>, gear carrier <NUM> is coupled to tape reel <NUM> and includes posts <NUM>, around which inner planetary gear <NUM> and outer planetary gear <NUM> are rotatably mounted. The gear teeth of outer planetary gear <NUM> interface with outer ring gear <NUM> and inner planetary gear <NUM>, the gear teeth of which also interface with sun gear <NUM>. Sun gear <NUM> is coupled to housing <NUM>, outer ring gear <NUM> is coupled to axle <NUM>, and spring <NUM> is coupled between tape reel <NUM> and axle <NUM>.

Referring to <FIG>, gear carrier <NUM> is coupled to axle <NUM> and includes posts <NUM>, around which inner planetary gear <NUM> and outer planetary gear <NUM> are rotatably mounted. The gear teeth of outer planetary gear <NUM> interface with outer ring gear <NUM> and inner planetary gear <NUM>, the gear teeth of which also interface with sun gear <NUM>. Outer ring gear <NUM> is coupled to tape reel <NUM>, sun gear <NUM> is coupled to housing <NUM>, and spring <NUM> is coupled between tape reel <NUM> and axle <NUM>.

Referring to <FIG>, gear carrier <NUM> is coupled to axle <NUM> and includes posts <NUM>, around which inner planetary gear <NUM> and outer planetary gear <NUM> are rotatably mounted. The gear teeth of outer planetary gear <NUM> interface with outer ring gear <NUM> and inner planetary gear <NUM>, the gear teeth of which also interface with inner ring gear <NUM>. Outer ring gear <NUM> is coupled to tape reel <NUM>, inner ring gear <NUM> is coupled to housing <NUM>, and spring <NUM> is coupled between tape reel <NUM> and axle <NUM>.

Referring to <FIG>, gear carrier <NUM> is coupled to axle <NUM>. Tape reel <NUM> includes posts <NUM>, around planetary gear <NUM> is rotatably mounted. The gear teeth of inner planetary gear <NUM> interface with outer ring gear <NUM>, and the gear teeth of outer planetary gear <NUM> interface with inner ring gear <NUM>. Outer gear ring <NUM> is coupled to housing <NUM>, inner gear ring <NUM> is coupled to gear carrier <NUM>, and spring <NUM> is coupled between tape reel <NUM> and axle <NUM>.

Referring to <FIG>, gear carrier <NUM> is coupled to axle <NUM>. Posts <NUM> are coupled to tape reel <NUM>, and planetary gears <NUM> are rotatably mounted to posts <NUM>. The gear teeth of outer planetary gear <NUM> interface with outer ring gear <NUM>, and the gear teeth of inner planetary gear <NUM> interface with inner ring gear <NUM>. Outer gear ring <NUM> is coupled to housing <NUM>, inner gear ring <NUM> is coupled to gear carrier <NUM>, and spring <NUM> is coupled between tape reel <NUM> and axle <NUM>.

Referring to <FIG>, gear carrier <NUM> is coupled to axle <NUM> and includes posts <NUM>, around which inner planetary gear <NUM> and outer planetary gear <NUM> are rotatably mounted. The gear teeth of outer planetary gear <NUM> interface with inner ring gear <NUM> and inner planetary gear <NUM>, the gear teeth of which also interface with outer ring gear <NUM>. Inner gear ring <NUM> is coupled to tape reel <NUM>, outer ring gear <NUM> is coupled to housing <NUM>, and spring <NUM> is coupled between tape reel <NUM> and axle <NUM>.

Referring now to <FIG>, in various embodiments, tape measure <NUM> may include one or more structures configured to reduce friction while tape reel or spool <NUM> is rotating (e.g., while housing <NUM> is paying out or retrieving tape blade <NUM>). On the left side of spool <NUM> in <FIG>, spool <NUM> is supported radially by axle or carrier <NUM> at contact surface <NUM>. On the right side of spool <NUM> in <FIG>, spool <NUM> is indirectly supported radially by carrier <NUM> via spool cover <NUM> at contact surface <NUM>. On both sides of carrier <NUM>, carrier <NUM> itself is confined by housing <NUM> at contact surface <NUM>.

In one embodiment, carrier <NUM> has a diameter of <NUM> and is created from diecast Zinc, although it is contemplated herein that other diameters, manufacturing methods and/or materials may be utilized and still practice the disclosure herein.

Contact surfaces <NUM>, which include the bearing interfacing surfaces of spool <NUM> and spool cover <NUM>, are located directly around carrier <NUM>. The area of contact surfaces <NUM> is reduced because the diameter of the bearing surface is smaller relative to other embodiments in which the bearing surface is located at an increased diameter from carrier <NUM>. As a result, the amount of energy lost to friction while spool <NUM> rotates is concurrently reduced. Therefore less torque is required to provide full retraction of spool <NUM> and of the tape blade.

Tape measure <NUM> includes dust cover <NUM>, which at least partially encloses the interface between planetary gears <NUM> and both sun gear <NUM> and outer ring gear <NUM> (best shown in <FIG>).

In the embodiment in <FIG>, similar to one or more other embodiments described herein, spring <NUM> is anchored to carrier <NUM> and spool <NUM>, and planetary gears <NUM> interface with and rotate around sun gear <NUM> (best shown in <FIG>). The outer periphery of planetary gears <NUM> also interface with outer ring gear <NUM>. Both spool <NUM> (also referred to as tape reel <NUM>) and carrier <NUM> (also referred to as axle <NUM>) rotate about the longitudinal axis of axle <NUM> relative to and within housing <NUM>.

Referring now to <FIG>, tape measure <NUM> also may include spool cover <NUM>, which is located on the opposite side of spool <NUM> relative to dust cover <NUM>. Spool cover <NUM> at least partially encloses internal chamber <NUM> of spool <NUM> where spring <NUM> is disposed. Spool cover <NUM> is rotatably fixed to spool <NUM> and rotates about carrier <NUM>. The tabs in spool cover <NUM> allow for easy rotational locking with spool <NUM> during assembly. Support ring <NUM> furthers a more secure coupling between spool cover <NUM> and spool <NUM>, thus reducing a chance of decoupling if tape measure <NUM> is dropped. In an alternative embodiment spool cover <NUM> is not fixed to spool <NUM>, and instead is permitted to rotate independently with respect to both carrier <NUM> and spool <NUM>.

Referring now to <FIG>, illustrated therein is another embodiment of tape measure <NUM>. In this embodiment, tape measure <NUM> is designed to create a direct load path between the primary mass of tape measure <NUM> (typically tape blade <NUM> and spring <NUM>) into housing <NUM> which improves durability and stability, for example during impact if tape measure <NUM> is dropped. Another aspect and advantage of this embodiment is that input torque is converted to higher turns at a lower torque, which is reacted at sun gear <NUM> / front housing <NUM>, causing tape reel <NUM> to rotate.

In the embodiment shown in <FIG>, spring <NUM> is anchored to carrier <NUM> and spool <NUM>. Carrier <NUM> spins freely with respect to housing <NUM> and spool <NUM>. Further, when tape blade <NUM> is being either paid out or retrieved into housing <NUM>, carrier <NUM> spins in the same direction as spool <NUM>, but at a slightly slower speed than spool <NUM>.

In this embodiment, spool <NUM> is radially supported by housing <NUM> on the right side of <FIG> at contact surface <NUM>, and by hubcap <NUM> on the left side of <FIG> at contact surface <NUM>. Contact surfaces <NUM>, which include the bearing interfacing surfaces of spool <NUM> and hubcap <NUM>, are located around housing <NUM> as indicated in <FIG>. Therefore, the area of contact surfaces <NUM> is slightly increased relative to <FIG> because the diameters of the bearing surfaces in <FIG> are relatively larger.

Hubcap <NUM> partially encloses the interface between planetary gears <NUM> and outer ring gear <NUM>. Hubcap <NUM> is rotatably fixed to spool <NUM> (e.g., via rivets, screws, and/or fasteners). In the embodiment illustrated in <FIG>, hubcap <NUM> extends from annular flange <NUM> to approximate a radially interior edge of planetary gears <NUM>. In this configuration hubcap <NUM> helps prevent contamination from entering the gear assembly. However, it is contemplated herein that hubcap <NUM> may have other configurations.

Also included in the embodiment in <FIG> is membrane <NUM>. Membrane <NUM> separates internal chamber <NUM> from the gears, including sun gear <NUM>, planetary gears <NUM>, and outer ring gear <NUM> (best shown in <FIG> and <FIG>). In one embodiment, outer ring gear <NUM> is configured to be disposed within an opening in spool <NUM> (best shown in <FIG>), such that outer ring gear <NUM> and spool <NUM> are rotatably fixed together.

Referring now to <FIG>, illustrated therein is an exemplary embodiment of carrier <NUM>. In this embodiment, carrier <NUM> includes gear carrier <NUM>, which extends radially from the primary axis of carrier <NUM>. Protruding from gear carrier <NUM> are several posts <NUM>, upon which planetary gears <NUM> are disposed, and around which planetary gears <NUM> axially rotate. In the embodiment illustrated in <FIG>, carrier <NUM> includes five posts <NUM>, although it is contemplated herein that any number of posts may be utilized, such as for exemplary purposes only and without limitation, <NUM>-<NUM> posts. Further, in one or more embodiments, such as <FIG>, posts <NUM> are symmetrically located on gear carrier <NUM> with respect to each other. It should be understood that while carrier <NUM> is shown as circular, in other embodiments carrier <NUM> may be any other suitable shape such as hexagonally shaped, D-shaped, oval shaped, an X-sided polygon, etc..

In one embodiment, carrier <NUM> has a diameter of <NUM> and is created from diecast Zinc, although it is contemplated herein that other diameters, manufacturing methods and/or materials may be utilized and still practice one or more disclosures herein.

Referring now to <FIG>, a method of assembly of an epicyclic geared tape measure, such as tape measure <NUM>, is shown. At step <NUM>, one side of membrane <NUM> is slightly lubricated, such as with grease. Membrane <NUM> is installed onto carrier <NUM> with the greased side of membrane <NUM> facing carrier <NUM>. Spring <NUM> is formed around the axle of carrier <NUM> at step <NUM>, and then wound. An external tail of spring <NUM> is captured, spool <NUM> is placed around spring <NUM> at step <NUM>, and the external tail of spring <NUM> is anchored to spool <NUM>.

Planetary gears <NUM> are lightly lubricated (e.g., with grease) between planetary gears <NUM> and posts <NUM>, and then planetary gears <NUM> are placed on posts <NUM> at step <NUM>. Outer ring gear <NUM> is placed around planetary gears <NUM> and the teeth of planetary gears <NUM> are lightly lubricated at step <NUM>. At step <NUM>, hubcap <NUM> is then placed over the gear assembly and fixedly attached to spool <NUM> (e.g., via screws). Then, at step <NUM> the spool assembly is placed into housing <NUM> (e.g., front housing) that includes sun gear <NUM>, such that planetary gears <NUM> are interfaced with sun gear <NUM>. Subsequently, at step <NUM> the rest of tape measure <NUM> is assembled, such as attaching a rear housing, a bumper, a brake, and/or housing screws to attach the housings.

The relative rotational speed of arbor <NUM> to spool <NUM> is partly based on whether tape blade <NUM> and spring <NUM> are wound in the same direction. To demonstrate a result of winding blade <NUM> and spring <NUM> in different directions, two embodiments are described below. In both embodiments, spring <NUM> is anchored to spool <NUM> on one end and to arbor <NUM> on the other end. In use, spool <NUM> and arbor <NUM> rotate in the same direction as each other when tape blade <NUM> is being either extracted or retracted. Spool <NUM> and arbor <NUM> are both coupled to housing <NUM> through gear train <NUM>. Tape blade <NUM> is wound around spool <NUM>, and when tape blade <NUM> is extended from housing <NUM>, energy is stored in spring <NUM> through the rotations of arbor <NUM> and spool <NUM>.

In a first embodiment, spring <NUM> and tape blade <NUM> are wound in the same direction and as a result spool <NUM> rotates faster than arbor <NUM>. For example, if a <NUM>:<NUM> spring turn ratio is used with this embodiment then spool <NUM> rotates <NUM> times while arbor <NUM> rotates <NUM> times, and the result is one turn of force is applied to spring <NUM> (instead of <NUM> turns as in a typical tape measure in which housing <NUM>, spring <NUM>, spool <NUM>, and arbor <NUM> are in series).

In a second embodiment, case spring <NUM> and tape blade <NUM> are wound in opposite directions and as a result, arbor <NUM> rotates faster than spool <NUM>. For comparison, if a <NUM>:<NUM> spring turn ratio is used with this embodiment then spool <NUM> rotates <NUM> times while arbor <NUM> rotates <NUM> times, and the result is one turn applied to the spring (instead of <NUM> turns as in a typical tape measure).

It should be understood that the figures illustrate the exemplary embodiments in detail, and it should be understood that the present application is not limited to the details or methodology set forth in the description or illustrated in the figures. It should also be understood that the terminology is for description purposes only and should not be regarded as limiting.

Further modifications and alternative embodiments of various aspects of the invention will be apparent to those skilled in the art in view of this description. Accordingly, this description is to be construed as illustrative only. The construction and arrangements, shown in the various exemplary embodiments, are illustrative only. Although only a few embodiments have been described in detail in this disclosure, many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter described herein. Some elements shown as integrally formed may be constructed of multiple parts or elements, the position of elements may be reversed or otherwise varied, and the nature or number of discrete elements or positions may be altered or varied. The order or sequence of any process, logical algorithm, or method steps may be varied or re-sequenced according to alternative embodiments. Other substitutions, modifications, changes and omissions may also be made in the design, operating conditions and arrangement of the various exemplary embodiments without departing from the scope of the present invention.

Unless otherwise expressly stated, it is in no way intended that any method set forth herein be construed as requiring that its steps be performed in a specific order. Accordingly, where a method claim does not actually recite an order to be followed by its steps or it is not otherwise specifically stated in the claims or descriptions that the steps are to be limited to a specific order, it is in no way intended that any particular order be inferred. In addition, as used herein, the article "a" is intended to include one or more component or element, and is not intended to be construed as meaning only one. As used herein, "rigidly coupled" refers to two components being coupled in a manner such that the components move together in a fixed positional relationship when acted upon by a force.

Claim 1:
A tape measure (<NUM>) comprising:
a housing (<NUM>);
an axle (<NUM>) rotatably mounted within the housing (<NUM>);
a tape reel (<NUM>) rotatably mounted within the housing (<NUM>) around the axle (<NUM>), the tape reel (<NUM>) comprising a radially inward-facing surface defining an interior reel cavity (<NUM>) and a radially outward-facing surface;
an elongate tape blade (<NUM>) wound around the radially outward-facing surface of the tape reel (<NUM>);
a hook assembly (<NUM>) coupled to an outer end of the elongate tape blade (<NUM>);
a spiral spring (<NUM>) located at least partially within the interior reel cavity (<NUM>) and at least partially surrounded by the elongate tape blade (<NUM>) in the radial direction, the spiral spring (<NUM>) is coupled between the tape reel (<NUM>) and the axle (<NUM>) such that when the elongate tape blade (<NUM>) is unwound from the tape reel (<NUM>) to extend from the housing (<NUM>) the spiral spring (<NUM>) stores energy, and the spiral spring (<NUM>) releasing energy drives rewinding of the elongate tape blade (<NUM>) on to the tape reel (<NUM>); and
a gear train (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) rotatably coupling the tape reel (<NUM>) and the axle (<NUM>) such that during extension of the elongate tape blade (<NUM>) from the housing (<NUM>), each full rotation of the tape reel (<NUM>) results in less than a full rotation of the axle (<NUM>);
wherein, during extension and rewinding of the elongate tape blade (<NUM>), both the axle (<NUM>) and tape reel (<NUM>) rotate within the housing (<NUM>);
wherein the axle (<NUM>) comprises a gear carrier (<NUM>) that extends radially outward from an end of the axle (<NUM>), the gear carrier (<NUM>) comprises a plurality of posts (<NUM>, <NUM>) extending along an axis parallel to a primary axis of the axle (<NUM>), and the gear train (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) comprises:
a sun gear (<NUM>) fixedly coupled to the housing (<NUM>);
an outer ring gear (<NUM>) fixedly coupled to the tape reel (<NUM>); and
a plurality of planetary gears (<NUM>, <NUM>, <NUM>, <NUM>) rotatably mounted to the plurality of posts (<NUM>, <NUM>), the plurality of planetary gears (<NUM>, <NUM>, <NUM>, <NUM>) rotatably engaging with the outer ring gear (<NUM>) and the sun gear (<NUM>).