Measuring tape with multi coil spring retraction system

Abstract

A measuring tape device may include a housing which may have an aperture, a reel assembly, a blade which may have a first end that may extend from the housing through the aperture and a second end wound on the reel assembly, a self-retraction assembly to retract the blade into the housing via the reel assembly and an end hook which may be disposed at the first end of the blade. The self-retraction assembly may include a spring having a plurality of coils, the plurality of coils comprising a first coil and a second coil arranged coaxially with, and disposed axially displaced with respect to the first coil.

Description

[0001] MEASURING TAPE WITH MULTI COIL SPRING RETRACTION SYSTEM

[0002] TECHNICAL FIELD

[0003] Example embodiments generally relate to measuring tape devices, and particularly relate to a measuring tape with an improved retraction system for a more compact design.

[0004] BACKGROUND

[0005] Measuring tapes have been around for a very long time, and are common measuring tools used in numerous contexts to obtain linear measurements. Measuring tapes can come in many forms and may be made of cloth, fiber glass, metal, plastic, or the like. The materials used are often dictated by the specific measuring application. For example, tailors and dressmakers typically use a flexible tape that can be easily manipulated between two hands to measure a distance therebetween. However, for construction or carpentry applications, a stiff and often metallic tape is preferred to allow the measuring tape to be extended between an a first location at which one end of the tape is anchored, and the location of the user at whose location the measuring tape is paid out from a reel assembly. The reel assembly may have a manual retracting mechanism or a self-retracting mechanism, typically depending upon the length of the measuring tape. For relatively short measuring tapes (e.g., 12 ft or 25 ft), selfretracting mechanisms are very common. For very long measuring tapes (e.g., larger than 100 ft), a manual retracting mechanism is typically employed.

[0006] For nearly a century, metallic tape ribbons with a curved and relatively stiff construction have been preferred for use in self-retracting measuring tapes. The metallic tape ribbon tends to be flexible enough to permit the metallic tape ribbon to be wound onto a spring loaded reel assembly, but stiff enough to have a relatively long standout. By employing an end hook at one end of the tape, the user may take advantage of the standout to pay out the measuring tape toward an anchor point on a media that is to be measured and then conduct the measurement without having to physically move to the anchor point to affix the end hook and then move away to make the measurement, with the self-retracting mechanism helping to hold the end hook in place. The self-retracting mechanism of some measuring tapes may occupy a relatively large amount of space when compared to the other components of the measuring tape, often making the measuring tape housing larger as well. Since many tradesmen and jobsite workers may need to carry measuring tapes on themselves at all times, having a more compact and portable measuring tape housing can be very attractive to consumers. BRIEF SUMMARY OF SOME EXAMPLES

[0007] Some example embodiments may provide for a measuring tape device. The measuring tape device may include a housing which may have an aperture, a reel assembly, a blade which may have a first end that may extend from the housing through the aperture and a second end wound on the reel assembly, a self-retraction assembly to retract the blade into the housing via the reel assembly and an end hook which may be disposed at the first end of the blade. The self-retraction assembly may include a spring having a plurality of coils, the plurality of coils comprising a first coil and a second coil arranged coaxially with, and disposed axially displaced with respect to the first coil.

[0008] Some example embodiments may provide for a retraction system for a measuring tape device. The retraction system may include a reel assembly, and a self-retraction assembly to retract a blade into a housing via the reel assembly. The self-retraction assembly may include a spring having a plurality of coils, the plurality of coils comprising a first coil and a second coil arranged coaxially with, and disposed axially displaced with respect to the first coil. The reel assembly may include a first drum reel and a second drum reel. The first and second drum reels may be substantially cylindrical and arranged coaxially with one another, an outer diameter of the second drum reel may be less than an inner diameter of the first drum reel.

[0009] BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

[0010] Having thus described some example embodiments in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:

[0011] FIG. 1 illustrates a perspective view of a measuring tape device in accordance with an example embodiment;

[0012] FIG. 2 illustrates a block diagram of the measuring tape device in accordance with an example embodiment;

[0013] FIG. 3 illustrates an exploded perspective view of a measuring tape retraction system in accordance with an example embodiment;

[0014] FIG. 4 illustrates a perspective view of the retraction system in accordance with an example embodiment;

[0015] FIG. 5 illustrates a perspective view of the spring and the second drum reel in accordance with an example embodiment;

[0016] FIG. 6 illustrates a perspective view of the first and second coils of the spring according to an example embodiment; FIG. 7 illustrates a side view of the first and second coils of the spring according to an example embodiment;

[0017] FIG. 8 illustrates a section view of the measuring tape device according to an example embodiment; and

[0018] FIG. 9 illustrates a block diagram of the measuring tape device in accordance with an example embodiment.

[0019] DETAILED DESCRIPTION

[0020] Some example embodiments now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all example embodiments are shown. Indeed, the examples described and pictured herein should not be construed as being limiting as to the scope, applicability or configuration of the present disclosure. Rather, these example embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like reference numerals refer to like elements throughout. Furthermore, as used herein, the term “or” is to be interpreted as a logical operator that results in true whenever one or more of its operands are true. As used herein, operable coupling should be understood to relate to direct or indirect connection that, in either case, enables functional interconnection of components that are operably coupled to each other.

[0021] As indicated above, some example embodiments may relate to the provision of a measuring tape device that may have an improved retraction system. To reduce the amount of space required for the retraction system of the measuring tape device, a spring may have a plurality of coils disposed side-by-side as opposed to one coil with a large outer diameter. Example embodiments are therefore directed to providing a retraction system that can effectively balance the desire to reduce the size of the measuring tape housing with the need to maintain the self-retracting functionality. Other efforts have been made to accomplish this, and such efforts may include the addition of additional springs to maintain a similar spring force and the same retraction functionality while reducing the size of the measuring tape. While effective for the primary purpose, these solutions are relatively expensive, and complicated to produce, due to the addition of more components. Some example embodiments therefore use a single spring separated into a plurality of coils to reduce the overall outer diameter size of the spring without increasing the complexity or manufacturing costs of the measuring tape. Thus, the resulting tape measure employing such retraction system can reduce the overall size of the measuring tape in a manner that is both cheaper and simpler than prior methods. The resulting device may therefore be more portable, more easily produced, and have improved cost efficiency.

[0022] FIG. 1 illustrates a perspective view of a measuring tape device. FIG. 2 illustrates a block diagram of such device, in accordance with an example embodiment. FIG. 3 illustrates an exploded perspective view of a measuring tape retraction system according to an example embodiment. FIG. 4 illustrates a perspective view of the retraction system according to an example embodiment. FIG. 5 illustrates a perspective view of the spring and the second drum reel in accordance with an example embodiment. FIG. 6 illustrates a perspective view of the first and second coils of the spring in accordance with an example embodiment. FIG. 7 illustrates a side view of the first and second coils of the spring in accordance with an example embodiment. FIG. 8 illustrates a section view of the measuring tape device according to an example embodiment. FIG. 9 illustrates a block diagram of the measuring tape device in accordance with an example embodiment.

[0023] Referring now to FIGS. 1 and 2, a measuring tape device 100 of an example embodiment may include a housing 110, inside which a retraction system 115 including a reel assembly 120 and a self-retraction assembly 130, may be provided. A blade 140 (or tape) portion of the device 100 may be wound onto the reel assembly 120. The blade 140 may be paid out through an aperture 150 formed in the housing 110. Although not required, in some cases, a locking assembly 160 may be provided to enable the retraction system 115 to be alternately locked and unlocked. When locked, the locking assembly 160 may prevent the selfretraction assembly 130 from retracting the blade 140, and when unlocked, the retraction system 115 may retract the blade 140 into the housing 110.

[0024] The blade 140 has an end hook 170 disposed at one end thereof, and is affixed to the reel assembly 120 at the other end of the blade 140. The end hook 170 may be affixed (temporarily) to an anchor point on a medium that is to be measured. Once the end hook 170 is affixed to the anchor point, the blade 140 may be paid out of the aperture 150 and unwound from the reel assembly 120. When a desired length of the blade 140 has been paid out, the user can make any necessary markings, readings, etc., associated with measuring scale markings that may be printed on the blade 140. The measuring scale markings generally measure length from the end hook 170 in one or more units, with divisions and subdivisions of such units clearly marked on the blade 140.

[0025] By fixing the end hook 170 to the anchor point, the self-retraction assembly 130 (which may be spring loaded in some cases) may be prevented from retracting the paid out portions of the blade 140 into the housing 110 (via the aperture 150). Similarly, when the locking assembly 160 is engaged, a force (e.g., a pinching force) may be placed on the blade 140 to prevent retraction or motion of the reel assembly 120 may otherwise be inhibited to prevent the selfretraction assembly 130 from retracting the paid out portions of the blade 140. However, when the end hook 170 is not anchored and the locking assembly 160 is not engaged, the selfretraction assembly 130 may cause the retraction system 115 to wind the blade 140 back onto the reel assembly 120.

[0026] As mentioned above, for a typical measuring tape, when the blade 140 is paid out through the aperture 150, the blade 140 will extend relatively straight out the aperture 150 (although some sagging or droop may be noticed due to the weight of the blade 140). The blade 140 can be extended in a guided fashion toward an intended target anchor point while the blade 140 continues to have sufficient rigidity to standout. The blade 140 will continue to extend and standout until the weight of the blade 140 extended past the aperture 150 is sufficient to cause the blade 140 to collapse and bend, thereby losing its rigidity and preventing any further guided extension.

[0027] FIG. 3 illustrates an exploded perspective view of the retraction system 115 of the measuring tape device 100 according to an example embodiment, and FIG. 4 depicts a perspective view of the retraction system 115 assembled, according to an example embodiment. Referring now to FIGS. 3 and 4, and as mentioned above, the retraction system 115 may include the reel assembly 120 and the self-retraction assembly 130. The reel assembly 120 may operably couple the blade 140 to the self-retraction assembly 130, which may wind the blade 140 back onto the reel assembly 120 responsive to the end hook 170 not being anchored and the locking assembly 160 being unlocked, which is also described above. In some cases, the reel assembly 120 may include a first drum reel 180 and a second drum reel 190. The first and second drum reels (180, 190) may each include a substantially cylindrical body which may be arranged coaxially with one another within the housing 110. In some embodiments, the first and second drum reels (180, 190) may be arranged one inside the other, whereas in some other cases, the first and second drum reels (180, 190) may be spaced apart along a longitudinal axis 185 shared by each drum reel (180, 190). In the embodiment shown in FIG. 3, the self-retraction assembly 130 may include a spring 200 which may be wound into a plurality of coils. The plurality of coils may include a first coil 210 and a second coil 220 arranged coaxially with, and disposed axially displaced with respect to the first coil 210. The first and second coils (210, 220) of the plurality of coils may be formed from a single, unitary, piece of metallic material. Each coil of the plurality of coils may include at least one full rotation of the spring 200, so that each coil may occupy a full inner diameter of an inner radial surface (184, 194) of the respective drum reel (180, 190) to which the coil is operably coupled. Thus, each coil may also include more than one full rotation of the spring 200, up to the respective inner diameter. Further, each coil may be distinguished from other coils of the plurality of coils by the location in the housing at which the coil resides. In some cases, for example, that may be to say that the first coil 210 may be disposed at the first drum reel 180 and the second coil 220 may be disposed at the second drum reel 190, axially displaced from the first coil 210. In an example embodiment, each coil of the plurality of coils may be separated by partitions operably coupled to the housing 110 that define each coil.

[0028] In this regard, both the first and second drum reels (180, 190) may be hollow (e.g. like a pipe or tube) and thus may include respective interior regions bound by the respective inner radial surface (182, 192) of each drum reel (180, 190). The first and second drum reels (180, 190) may therefore also each include a respective outer radial surface (184, 194) that may wrap around an exterior of the curved portion of the substantially cylindrically shaped body of each drum reel (180, 190). In this regard, the first drum reel 180 may operably couple to the blade 140 at the outer radial surface 184 and may also be wound around the outer radial surface 184 of the first drum reel 180 accordingly. In an example embodiment, the first drum reel 180 may include retention walls 183 disposed at opposing axial ends of the first drum reel 180. In such cases, the retention walls 183 may help the first drum reel 180 to function like a spool, and the retention walls 183 may align the blade 140 with the outer radial surface 184 as the blade 140 is wound onto and unwound off of the outer radial surface 184 accordingly.

[0029] In some embodiments, such as the one shown in FIG. 3, the spring 200 may be a helical spring, and more particularly, may be a type of spiral spring. Spiral springs typically comprise a rectangular flat strip of a metallic material that has been coiled up into a large spiral shape. In many cases, the center of the spiral spring may be fixed and the end of the coiled material on the outermost layer may be free. Pulling on the free end of the spiral spring will cause the spiral spring to radially contract (e.g. wind tighter) about the fixed end, and as the spiral spring radially contracts, the spring may build up potential energy derived from the spring force as the material resists the contracting motion. The built up potential energy in the spring may be converted to kinetic energy responsive to the free end of the spiral spring being released and the spiral spring expanding to return to its original position / shape. In the context of the measuring tape device 100, as the blade 140 is paid out of the aperture 150, the reel assembly 120 rotates the self-retraction assembly 130 and thus the spring 200 contracts radially and stores potential energy. When the end hook 170, the locking assembly 160, or both, are released, the spring 200 may be free to return to its original shape. In doing so, the spring 200 may rotate the reel assembly 120 to retract the blade 140 into the housing 110. In some cases, the plurality of coils of the spring 200 may radially contract simultaneously as the blade 140 gets paid out of the housing 110. In this regard, both the first coil 210 and the second coil 220 may have their outer diameters reduced at the same time and rate responsive to the blade 140 being paid out of the housing 110. In another example embodiment, the plurality of coils of the spring 200 may radially contract consecutively. In other words, the first coil 210 may have its outer diameter reduced responsive to the blade 140 being paid out of the housing 110 before the second coil 220 begins to contract.

[0030] Typically, a spiral spring may have a relatively large outer diameter due to the spiral spring needing room to physically contract and expand, radially, as it is operated. In this regard, the original or unaltered position / shape of the spiral spring may leave space between each layer of the coiled metallic material so that the spring is able to radially contract accordingly. Thus, in its original or unaltered position / shape, the outer diameter of the spiral spring may be at its largest, and depending on the specific use case of the spring and how much spring force is required, the outer diameter could get relatively large. In order to make the spring 200 more compatible for a compact use case (i.e. within the measuring tape housing 110), an object of the present invention may be for the spring 200 to be spread into the plurality of coils axially displaced from one another and arranged around the common longitudinal axis 185 to make the spring 200 more radially compact overall. In this regard, the plurality of coils may contain the same amount of metallic material coiled up as a spring with just a single coil, but the material of the spring 200 with multiple coils may be spread out amongst the plurality of coils. Thus, each consecutive coil in the plurality may have a slightly smaller outer diameter than the previous coil as a result of pulling the material axially away from each coil, which may therefore reduce the overall amount of radial space that the spring 200 may occupy. In other words, the spring 200 may still provide sufficient torque to the reel assembly 120 to retract the blade 140, but the overall outer diameter of the spring 200 may be reduced due to the material being spread amongst the plurality of coils rather than one large coil.

[0031] In this regard, while the blade 140 may be operably coupled to the outer radial surface 184 of the first drum reel 180, the first coil 210 of the plurality of coils may be operably coupled to the first drum reel 180 at the inner radial surface 182. In some other cases, the first coil 210 of the spring 200 may be operably coupled directly to the blade 140. In either case, the outer diameter of the first coil 210 of the spring 200 may be limited by the inner diameter of the interior region of the first drum reel 180, since the outer diameter of the first coil 210 may not exceed the inner diameter of the inner radial surface 182. A free outer end of the spring 200 at an outer edge of the first coil 210 may be operably coupled to the inner radial surface 182 accordingly. Thus, as the blade 140 is paid out of the housing 110, the first drum reel 180 may rotate as the blade unwinds from the first drum reel 180, which may accordingly pull on the free outer end of the spring 200 and cause the spring 200 to radially contract and store energy as discussed above.

[0032] FIG. 5 illustrates a perspective view of the spring 200 and the second drum reel 190 in accordance with an example embodiment with the first drum reel 180 removed for illustrative purposes. FIG. 6 similarly illustrates a perspective view of the first and second coils (210, 220) of the spring 200 in accordance with an example embodiment with the first drum reel 180 and the second drum reel 190 removed for illustrative purposes. FIG. 7 illustrates a side view of the first and second coils (210, 220) of the spring 200 in accordance with an example embodiment. Referring now to FIGS. 5-7, at an interior of the first coil 210, the spring 200 material may spiral laterally (i.e. axially) away from the first coil 210 and to the second coil 220. The second coil 220 may thus be disposed proximate to the first coil 210 and axially aligned with the first coil 210 since the second coil 220 may simply be an extension of the spring 200 material from the first coil 210. In some cases, the combined axial length of the plurality of coils, with each individual coil disposed axially displaced from each other, may be substantially equal to, or less than, a width of the blade 140.

[0033] The second coil 220 may be operably coupled to the second drum reel 190 as well. In this regard, the second coil 220 may be operably coupled to the second drum reel 190 at the inner radial surface 192 of the second drum reel 190. In some embodiments, the second drum reel 190 may not rotate. In this regard, the second drum reel 190 may be fixed relative to the housing 110 at a distal axial end of the second drum reel 190. In some cases, the second drum reel 190 need not be a separate component at all, and may instead be formed as a cylindrical extension of the housing 110 that may be integral to the housing 110. In any case, the second coil 220 may thus contain the fixed end of the spring 200 that allows the spring 200 to build up potential energy in response to the first drum reel 180 rotating as the blade 140 is paid out of the aperture. Paying out the blade 140 may cause the first drum reel 180 to rotate and the spring 200 to wind in both the first and second coils (210, 220), building up the stored energy in the spring 200. As such, one rotation of the first drum reel 180 due to the blade 140 is shared between each of the first and second coils (210, 220) so that more blade 140 length may be paid out for less rotations of the spring 200 due to it having a smaller outer diameter.

[0034] FIG. 8 illustrates a section view of the measuring tape device 100 according to an example embodiment. FIG. 8 depicts the blade 140 wound around the first drum reel 180 disposed between the retention walls 183 within the housing 110. The section view shown in FIG. 8 also depicts the first and second coils (210, 220) of the spring 200 disposed inside the first and second drum reels (180, 190) respectively. The first and second coils (210, 220) may be operably coupled to each other by a central portion of the spring 200 that extends substantially perpendicularly or axially between the first and second coils (210, 220). The central portion of the spring 200 may be parallel, and in some cases coaxial with, the longitudinal axis 185 of the first and second drum reels (180, 190). In this regard, in an example embodiment, the self-retraction assembly 130 may only comprise the single spring 200. The second drum reel 190 is also shown to be operably coupled to the housing at a distal axial end of the second drum reel 190, while also extending from the housing 110 into the interior region of the first drum reel 180 that is bound by the inner radial surface 182. In other words, the second drum reel 190 may nest within the first drum reel 180. The first drum reel 180 may thus be axially longer than the second drum reel 190. In some cases, the second drum reel may be about half as long as the first drum reel 180 in the axial direction (i.e. in a direction parallel to the longitudinal axis 185).

[0035] Also of note with respect to the retraction system 115, there may be no central post or axle to which the spring is operably coupled. In this regard, some other examples of measuring tapes may include a central axle extending along the longitudinal axis 185, which serves as an axis of rotation as well as a means to fix the end of the spring or springs. The embodiments shown and described herein may not include the central post since the second drum reel 190 helps accomplish the necessary functions. In other words, the second drum reel 190 may help fix the end of the spring 200 relative to the housing 110, and it may help to define an axis of rotation for the first drum reel 180 by extending into the interior region of the first drum reel 180 accordingly. Thus, the present invention may simplify the measuring tape device 100 to not need a central post / axis as well as to only require a single spring 200.

[0036] FIG. 9 illustrates a block diagram of the measuring tape device 100 in accordance with an example embodiment. In some cases, it is important to note that the spring 300 may be separated into more than two coils in the plurality of coils. In such cases, any additional number of coils in the plurality of coils of the spring 300 may be achieved based on the application for the spring 300 and other design constraints that may need to be met. As such, FIG. 9 illustrates an example embodiment in which the plurality of coils may include a first, second and third coil (310, 320, 330). In such cases, the first coil 310 may still be operably coupled to the first drum reel 180, but the third coil 330 may be operably coupled to the second drum reel 190 instead of the second coil 320 being operably coupled to the second drum reel 190. In other words, the first drum reel 180 may be operably coupled to the blade 140 at an outer radial surface 184 of the first drum reel 180 and to the first coil 310 of the spring 300 at an inner radial surface 182 of the first drum reel 180, and the second drum reel 190 may be operably coupled to the third coil 330 of the spring 300 at an inner radial surface 192 of the second drum reel 190 and to the housing 110 at a distal axial end of the second drum reel 190. The second coil 320 may, in such cases, be an intermediate coil disposed in between the first and third coils (310, 330), accordingly. In this regard, the outer diameter of the spring 300 may be even smaller and more radially compact than the spring 200 comprising just two coils, without sacrificing any performance of the spring 300. Thus, the third coil 330 may be arranged coaxially with, and disposed axially displaced to the second coil 320, which may be arranged coaxially with, and disposed axially displaced to the first coil 310. It should also be appreciated that any number of coils may be provided in the plurality of coils, and that the examples discussed herein where the plurality of coils comprises two and three coils, respectively, are merely provided as examples and are not meant to represent an exhaustive list of possibilities.

[0037] Some example embodiments may provide for a measuring tape device. The measuring tape device may include a housing which may have an aperture, a reel assembly, a blade which may have a first end that may extend from the housing through the aperture and a second end wound on the reel assembly, a self-retraction assembly to retract the blade into the housing via the reel assembly and an end hook which may be disposed at the first end of the blade. The self-retraction assembly may include a spring having a plurality of coils, the plurality of coils comprising a first coil and a second coil arranged coaxially with, and disposed axially displaced with respect to the first coil.

[0038] The measuring tape device of some embodiments may include additional, optional features, and / or the features described above may be modified or augmented. Some examples of modifications, optional features and augmentations are described below. It should be appreciated that the modifications, optional features and augmentations listed below may each be added alone, or they may be added cumulatively in any desirable combination. For example, in some embodiments, the reel assembly may include a first drum reel and a second drum reel. In some cases, the first and second drum reels may be substantially cylindrical and may be arranged coaxially with one another, an outer diameter of the second drum reel may be less than an inner diameter of the first drum reel. In an example embodiment, the first drum reel may be operably coupled to the second end of the blade at an outer radial surface of the first drum reel, and the first drum reel may be operably coupled to the first coil of the spring at an inner radial surface of the first drum reel. In some cases, the second drum reel may be operably coupled to the second coil of the spring at an inner radial surface of the second drum reel and to the housing at a distal axial end of the second drum reel. In an example embodiment, the second drum reel may extend into an interior region of the first drum reel bounded by the inner radial surface of the first drum reel. In some cases, the first drum reel may carry the blade and may be rotatable relative to the housing and the second drum reel and the second drum reel may be fixed relative to the housing. In an example embodiment, the first drum reel may rotate responsive to the blade exiting the housing and entering the housing. In some cases, responsive to the blade exiting the housing, the first and second coils of the spring may radially contract either simultaneously or consecutively. In an example embodiment, the plurality of coils may be formed from a single unitary piece of metallic material. In some cases, the plurality of coils may include a third coil arranged coaxially with, and disposed axially displaced with respect to the second coil. In an example embodiment, the reel assembly may include a first drum reel and a second drum reel. In some cases, the first and second drum reels may be substantially cylindrical and arranged coaxially with one another, an outer diameter of the second drum reel may be less than an inner diameter of the first drum reel. In an example embodiment, the first drum reel may be operably coupled to the blade at an outer radial surface of the first drum reel, and the first drum reel may be operably coupled to the first coil of the spring at an inner radial surface of the first drum reel. In some cases, the second drum reel may be operably coupled to the third coil of the spring at an inner radial surface of the second drum reel and to the housing at a distal axial end of the second drum reel.

[0039] Some example embodiments may provide for a retraction system for a measuring tape device. The retraction system may include a reel assembly, and a self-retraction assembly to retract a blade into a housing via the reel assembly. The self-retraction assembly may include a spring having a plurality of coils, the plurality of coils comprising a first coil and a second coil arranged coaxially with, and disposed axially displaced with respect to the first coil. The reel assembly may include a first drum reel and a second drum reel. The first and second drum reels may be substantially cylindrical and arranged coaxially with one another, an outer diameter of the second drum reel may be less than an inner diameter of the first drum reel.

[0040] Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Moreover, although the foregoing descriptions and the associated drawings describe exemplary embodiments in the context of certain exemplary combinations of elements and / or functions, it should be appreciated that different combinations of elements and / or functions may be provided by alternative embodiments without departing from the scope of the appended claims. In this regard, for example, different combinations of elements and / or functions than those explicitly described above are also contemplated as may be set forth in some of the appended claims. In cases where advantages, benefits or solutions to problems are described herein, it should be appreciated that such advantages, benefits and / or solutions may be applicable to some example embodiments, but not necessarily all example embodiments. Thus, any advantages, benefits or solutions described herein should not be thought of as being critical, required or essential to all embodiments or to that which is claimed herein. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

THAT WHICH IS CLAIMED:

1. A measuring tape device comprising: a housing having an aperture; a reel assembly; a blade having a first end configured to extend from the housing through the aperture and a second end configured to be wound on the reel assembly; a self-retraction assembly to retract the blade into the housing via the reel assembly; and an end hook disposed at the first end of the blade, wherein the self-retraction assembly comprises a spring having a plurality of coils, the plurality of coils comprising a first coil and a second coil arranged coaxially with, and disposed axially displaced with respect to the first coil.

2. The device of claim 1, wherein the reel assembly comprises a first drum reel and a second drum reel, and wherein the first and second drum reels are substantially cylindrical and arranged coaxially with one another, an outer diameter of the second drum reel being less than an inner diameter of the first drum reel.

3. The device of claim 2, wherein the first drum reel is operably coupled to the second end of the blade at an outer radial surface of the first drum reel, and wherein the first drum reel is operably coupled to the first coil of the spring at an inner radial surface of the first drum reel.

4. The device of claim 3, wherein the second drum reel is operably coupled to the second coil of the spring at an inner radial surface of the second drum reel and to the housing at a distal axial end of the second drum reel.

5. The device of claim 2, wherein the second drum reel extends into an interior region of the first drum reel bounded by an inner radial surface of the first drum reel.

6. The device of claim 2, wherein the first drum reel carries the blade and is rotatable relative to the housing and the second drum reel and the second drum reel is fixed relative to the housing.

7. The device of claim 6, wherein the first drum reel rotates responsive to the blade exiting the housing and entering the housing, and wherein responsive to the blade exiting the housing, the first and second coils of the spring radially contract either simultaneously or consecutively.

8. The device of claim 1, wherein the plurality of coils is formed from a single unitary piece of metallic material.

9. The device of claim 1, wherein the plurality of coils further comprises a third coil arranged coaxially with, and disposed axially displaced with respect to the second coil.

10. The device of claim 9, wherein the reel assembly comprises a first drum reel and a second drum reel, wherein the first and second drum reels are substantially cylindrical and arranged coaxially with one another, an outer diameter of the second drum reel being less than an inner diameter of the first drum reel, wherein the first drum reel is operably coupled to the blade at an outer radial surface of the first drum reel, wherein the first drum reel is operably coupled to the first coil of the spring at an inner radial surface of the first drum reel, and wherein the second drum reel is operably coupled to the third coil of the spring at an inner radial surface of the second drum reel and to the housing at a distal axial end of the second drum reel.

11. A retraction system for a measuring tape device, the retraction system comprising: a reel assembly; and a self-retraction assembly to retract a blade into a housing via the reel assembly,wherein the self-retraction assembly comprises a spring having a plurality of coils, the plurality of coils comprising a first coil and a second coil arranged coaxially with, and disposed axially displaced with respect to the first coil, wherein the reel assembly comprises a first drum reel and a second drum reel, and wherein the first and second drum reels are substantially cylindrical and arranged coaxially with one another, an outer diameter of the second drum reel being less than an inner diameter of the first drum reel.

12. The system of claim 11, wherein the first drum reel is operably coupled to the second end of the blade at an outer radial surface of the first drum reel, and wherein the first drum reel is operably coupled to the first coil of the spring at an inner radial surface of the first drum reel.

13. The system of claim 12, wherein the second drum reel is operably coupled to the second coil of the spring at an inner radial surface of the second drum reel and to the housing at a distal axial end of the second drum reel.

14. The system of claim 11, wherein the second drum reel extends into an interior region of the first drum reel bound by an inner radial surface of the first drum reel.

15. The system of claim 11, wherein the first drum reel carries the blade and is rotatable relative to the housing and the second drum reel and the second drum reel is fixed relative to the housing.

16. The system of claim 15, wherein the first drum reel rotates responsive to the blade exiting the housing and entering the housing, and wherein responsive to the blade exiting the housing, the first and second coils of the spring radially contract either simultaneously or consecutively.

17. The system of claim 11, wherein the plurality of coils is formed from a single unitary piece of metallic material.

18. The system of claim 11, wherein the plurality of coils further comprises a third coil arranged coaxially with, and disposed axially displaced with respect to the second coil.

19. The system of claim 18, wherein the reel assembly comprises a first drum reel and a second drum reel, and wherein the first and second drum reels are substantially cylindrical and arranged coaxially with one another, an outer diameter of the second drum reel being less than an inner diameter of the first drum reel.

20. The system of claim 19, wherein the first drum reel is operably coupled to the blade at an outer radial surface of the first drum reel, wherein the first drum reel is operably coupled to the first coil of the spring at an inner radial surface of the first drum reel, and wherein the second drum reel is operably coupled to the third coil of the spring at an inner radial surface of the second drum reel and to the housing at a distal axial end of the second drum reel.

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