Rule assembly with increased blade standout

The present invention comprises a retractable rule assembly that includes a housing assembly and a reel rotatably mounted in the housing assembly. An elongated blade formed of a ribbon of metal is mounted on the reel. One end of the blade is connected to the reel. The blade is constructed and arranged with respect to the housing assembly to extend from a position tangential to the reel outwardly through a spaced opening in the housing assembly. A coil spring that is formed of a ribbon of metal has a construction and arrangement between the housing assembly and the reel to rotate the reel in the housing assembly in a direction to wind the elongated blade about the reel when the blade is extending outwardly of the housing assembly opening. The blade has a “normal” concavo-convex cross-sectional configuration when extended and has a flat cross-sectional configuration when it is wound about the reel so that the wound reel is disposed about the reel in an abutting volute coil formation. A blade holding assembly is provided which can hold the blade in any position of extension outwardly of the housing assembly opening and to release the blade from any position in which it is held. The blade has a width in its flattened configuration thereof within the range of 1.10″-1.5″ and a height in its concavo-convex configuration thereof within the range of 0.25″-0.40″.

The present invention is generally related to retractable tape rule assemblies and more particularly to tape rule assemblies of the spring retractable type.

BACKGROUND OF THE INVENTION

Spring retractable rule assemblies have been available commercially for many years. It is also known in the tape rule industry to provide a concavo-convex tape rule blade with a standard width dimension of ¼″, ½″, ¾″ or 1″, with a height dimension as high as 0.226″ as disclosed in U.S. Pat. No. 4,429,462 to Rutty et al. There always exists a need to provide a retractable rule assembly that presents new and innovative blade configurations.

BRIEF DESCRIPTION OF THE INVENTION

The present invention comprises a retractable rule assembly that includes a housing assembly and a reel rotatably mounted in the housing assembly. An elongated blade formed of a ribbon of metal is mounted on the reel. One end of the blade is connected to the reel. The blade is constructed and arranged with respect to the housing assembly to extend from a position tangential to the reel outwardly through a spaced opening in the housing assembly. A coil spring that is formed of a ribbon of metal has a construction and arrangement between the housing assembly and the reel to rotate the reel in the housing assembly in a direction to wind the elongated blade about the reel when the blade is extending outwardly of the housing assembly opening. The blade has a “normal” concavo-convex cross-sectional configuration when extended and has a flat cross-sectional configuration when it is wound about the reel so that the wound reel is disposed about the reel in an abutting volute coil formation. A blade holding assembly is provided which can hold the blade in any position of extension outwardly of the housing assembly opening and to release the blade from any position in which it is held. The blade has a width in its flattened configuration thereof within the range of 1.10″-1.5″ and a height in its concavo-convex configuration thereof within the range of 0.25″-0.40″.

It is also contemplated to provide a wide range of tape assembly embodiments having increased blade standout. More particularly, in the more specific aspects of the present invention, it is a further objective to provide a retractable rule assembly having a blade constructed according to the principles briefly described above to provide the improved standout characteristics previously described with any combination of the following additional features:1. A retractable rule assembly wherein a relatively short free end portion of the blade has a clear film of plastic material adhered to a concave side thereof.2. A retractable rule assembly wherein the metal ribbon of the spring has a width which is 95%-120% of the width of the metal ribbon of the blade.3. A retractable rule assembly wherein the blade has an end hook member on the free end thereof, the end hook member being formed of sheet metal of a predetermined thickness to include a concavo-convex mounting portion having a U-shaped hook portion bent at a generally right angle from an end thereof, the end hook member being mounted on the free end of the blade with the mounting portion thereof secured in limited sliding engagement with a concave side of the fee end of the blade so that the rule can be measured externally from an exterior surface of the U-shaped hook portion or internally from an interior surface of the U-shaped hook portion, the U-shaped hook portion including a bight section extending transversely from a convex side of the free end of the blade and spaced leg sections extending beyond transversely spaced corners of the free end of the blade.4. A retractable rule assembly wherein the housing assembly includes a pair of cooperating housing members, each including an end wall having a peripheral wall extending from a periphery thereof and terminating in a free edge, the housing members being fixed together with their free edges interengaged by a plurality of bolts extending through one of the housing members and threadedly engaged in the other at spaced positions adjacent the peripheral walls thereof and by a fixed reel spindle having a non-circular interengaging recess-projection connection at each end thereof with the central interior of the adjacent end wall, each end of the spindle being interiorly threaded to threadedly receive a blot therein extending through a central hole in the adjacent end wall and the recess-projection connection between the central hole and threaded interior.5. A retractable rule assembly wherein the housing assembly includes a fitment defining a part of the housing assembly opening adjacent a convex side of the blade, the fitment having a plurality of tangentially extending transversely spaced elongated ridges defining surfaces for engaging the convex side of the blade extending tangentially from the reel to said housing assembly opening.6. The housing assembly includes a bottom wall having an exterior portion at an end position adjacent the housing assembly opening which projects below the exterior surface portion extending therefrom toward an opposite end to provide a finger grip enhancing configuration.7. The housing opening has a height dimension which exceeds the height dimension of the blade an amount that is at least approximately equal to the amount the hook position extends below the bottom end surface of the housing assembly at the housing opening.

In the broader aspects of the present invention, it is an objective to provide any known retractable rule assembly with improved blade standout by constructing a blade therefor to have the blade cross-sectional geometry briefly described above and/or the blade dimensions as previously described.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1-3show an exterior view of a retractable rule assembly that is generally designated10and is constructed according to the principles of the present invention. The rule assembly10includes a housing assembly12and a reel14that is rotatably mounted inside the housing assembly12(best seen in the cross-sectional views of FIGS.4-6). The reel14is mounted in the housing assembly12by a reel spindle15that is secured within the housing assembly12(FIGS.4-6). An elongated tape rule blade16is mounted on the reel14.

The blade16is formed of a ribbon of metal, the preferred metal being steel, and the top concave surface of the blade is printed with measuring lines and digits (not shown) for measuring lengths and distances. One longitudinal end18of the blade16is connected to the reel14and a second longitudinal free end20of the blade16extends generally outwardly of the reel14. The blade16is constructed and arranged with respect to the housing assembly12to extend generally from a position tangential of the reel14outwardly through a spaced opening22provided in the housing assembly12(as shown, for example, in FIG.4).

Preferably the reel14is made of a molded plastic and is provided with slots or openings24,26in a central cylindrical wall portion28thereof. The one end18of the blade terminates in a hook-like structure30that hookingly engages an edge of the wall portion28of the reel14at opening24to connect the end18of the blade16to the reel14(FIGS. 4,5).

A coil spring32has a construction and arrangement between the housing assembly12and the reel14to rotate the reel14with respect to the housing assembly12in a direction to wind the elongated blade16about the reel when the blade16is extending outwardly of the housing assembly opening22. The coil spring32is generally enclosed within the central wall portion28of the reel14(FIGS.4-6). One longitudinal end35of the coil spring32hookingly engages an edge of the wall portion28of the reel14that defines the opening26; a second longitudinal end37of the blade16hookingly engages the spindle15. The spindle15is rigidly mounted to the housing assembly12in a manner considered in detail below. Preferably the spring32is a thin, flat ribbon of metal, the preferred metal being steel.

The blade16is generally movable between a fully retracted position outwardly of the housing assembly12to a fully extended position. The fully retracted position of the blade16is shown in FIG.4and the fully extended position of the blade is shown (in fragmentary view) in FIG.5. It can be appreciated from a comparison of FIG.4andFIG. 5that as the blade is unwound from the reel14, the coil spring32is wound around the rigidly fixed spindle15. This winding of the spring around the spindle stores energy in the spring to provide spring powered rewinding of the blade16around the reel14when the extended blade is released.

The blade16is constructed of a ribbon of sheet metal that is shaped during the manufacturing to have a normal or memory configuration that has a generally arcuate or concavo-convex transverse cross-section. When a portion of the blade16is wound about the reel14, the wound portion has a flat transverse cross-section (FIGS. 6 and 8) and the wound layers of the coiled blade provide the wound blade with an abutting volute coil configuration. A representative transverse cross-section of the extended blade16showing its concavo-convex configuration is illustrated in FIG.7. It can therefore be understood from a comparison ofFIGS. 4-5(and from a comparison ofFIGS. 7-8) that when the blade16is wound around the reel14, it has the flat cross-section of FIG.8and when the blade16is withdrawn from the housing assembly12to measure an object, it returns to the concavo-convex cross-section shown in FIG.7. Thus, the coil spring32is constructed and arranged between the housing assembly12and the reel14to rotate the reel14about the spindle with respect to the housing assembly12in a direction to wind up the elongated blade16when extending outwardly of the housing assembly opening22in a normal concavo-convex cross-sectional configuration onto the reel14in an abutting volute coil formation in a flattened cross-sectional configuration. The concavo-convex cross-section provides the extended blade with rigidity and maintains the blade essentially straight in the longitudinal direction.

The concavo-convex cross-section of the blade generally provides the unsupported blade16with blade standout. As described in greater detail below, the blade16has a blade width, thickness and height of concavo-convex curvature sufficient to enable the blade16to standout arcuately a length measured along the blade of at least 10.5 feet with a horizontal linear length of standout thereof that is greater than 97 percent of the arcuate length of standout. As also described in greater detail below, the concavo-convex transverse cross-section of the blade16is provided with a geometry that also improves blade standout.

Generally, one skilled in the art will understand that the length of blade standout depends on many factors, including (but not limited to) blade width (i.e. the transverse width of the blade measured when the blade is in its flattened condition shown, for example, in FIG.8and designated F); the height of the blade16in the concavo-convex configuration (designated H in FIG.7); blade thickness (designated T in FIG.7); and the geometry of the blade transverse cross-section when the same is in its normal concavo-convex than configuration. The blade12has a width in the flattened condition thereof having a dimension within the broad range of from approximately 1.10 inches to approximately 1.5 inches and a height H in the concavo-convex configuration thereof having a dimension within the broad range of approximately 0.25 inch to approximately 0.40 inch. Preferably, the blade12has a thickness in either configuration thereof within the broad range of approximately 0.0045 inch to approximately 0.0063 inch. More preferably, the blade12has a width in the flattened condition thereof having a dimension within the narrower range of from approximately 1.25 inches to approximately 1.39 inches; a height H in the concavo-convex configuration thereof having a dimension within the narrower range of approximately 0.30 inch to approximately 0.35 inch; and a thickness in either configuration thereof having a dimension within the narrower range of approximately 0.005 inch to approximately 0.0056 inch. Most preferably the blade16width is approximately 1.25 inch, the blade height H is approximately 0.32 inch and the blade thickness T is approximately 0.0051 inch. A blade constructed according to these principles has a blade standout of up to approximately 13 feet. More specifically, a blade construction having dimensions within the broadest ranges identified immediately above for the width F, height H and thickness T can have a blade standout in the preferred broad range of at least 10.5 feet to approximately 13 feet; a blade construction having dimensions within the more referred narrower ranges identified immediately above for the width F, height H and thickness T can have a blade standout in the range of at least 10.5 feet to approximately 12.5 feet; and a blade construction having the most preferred dimensions identified immediately above for the width F, height H and thickness T has a blade standout of approximately 11 feet.

The concavo-convex cross-section of the blade16has a unique geometry (shown inFIG. 7) that increases in the standout ability. The concavo=convex cross-sectional configuration of the blade16includes an arcuate central section36and integral arcuate end sections38. Each arcuate end section38has the same radius of curvature (indicated for one of the two end sections38inFIG. 7by the line designated R1). The central section36has a radius of curvature designated R2(FIG.7). The radii of curvature R1for the two end sections38are greater than the radius of curvature R2of the central section36. The central section having a radius R2extends through an angular extent designated X in FIG.7. Preferably angle X is approximately 84 degrees.

Preferably the arcuate central section36has a radius of curvature R2that is a dimension within the broad range of approximately 0.30″ to approximately 0.60″; and the radius of curvature R1of each end section38is a dimension within the broad range of approximately 1.0″ to approximately 5.0″. More preferably the arcuate central section36has a radius of curvature R2that is a dimension within the narrower range of approximately 0.40″ to approximately 0.50″ and the radius of curvature R1of each end section38is a dimension within the narrower range of approximately 2.0″ to approximately 4.0″. Most preferably, the arcuate central section36has a radius of curvature R2of approximately 0.46″ and the radius of curvature of each end section R1is approximately 3.0″.

The transverse cross-sections of prior art tape blades are either constant curves (i.e., constant radius of curvature) or are constant curves in the center of the blade with straight (i.e. flat) sections at each transverse end of the cross-section when the blade is extended. Blades constructed to have either these basic cross-sections are less stable during blade standout and show a greater tendency to buckle than blades having cross-sections constructed according to the present invention.

FIG. 9shows a comparison of the construction and standout capabilities of three prior art rule assemblies (shown in the first six rows of the table and indicated with a bracket) with a preferred embodiment of the rule assembly10constructed according to the principal of the present invention (shown in the last five rows of the table). As the first column ofFIG. 9indicates, typical prior art rule blades did not exceed one inch in width (measured in the flattened, coiled configuration of the blade). The second column indicates that prior art blade thickness for a one inch blade ranged from 0.0045 inch to 0.0056 inch and produced blade having a standout length of from approximately 7 feet to approximately 9 feet as indicated inFIG. 9, the third column.

The embodiment of the rule assembly constructed according to the principles of the present invention shown inFIG. 9has a blade width of 1.250 inches (in the flat configuration) and a blade thickness of 0.0051 inch. Preferably, the blade described inFIG. 9has a concavo-convex cross-section in the extended configuration as described above and as shown in FIG.8.

The last five columns inFIG. 9compare the standout characteristics of the three prior art tape assemblies with the tape assembly10constructed according to the principles of the invention. The standout characteristics of the blade of a given tape assembly are best understood by comparing the arcuate (i.e., actual) length-out measured along the surface of the blade with the linear length-out of the blade. These two characteristics are often expressed as a percentage of linear length-out to arcuate length-out.FIG. 10shows a schematic diagram that illustrates what is meant by arcuate length-out and linear length-out.

Arcuate length-out is represented by arcuate line C in FIG.10and is a measure of the total length of the extended portion of the blade. Linear length-out is designated B in FIG.10and is a measure of the linear length of the protection of the extended blade on an imaginary horizontal surface below the tape assembly10. Line A designates the height the housing assembly10is required to be above the horizontal surface when the housing assembly12is angularly oriented with respect to the surface at an angle D to position the arcuately extending blade so that the free end thereof just touches the surface. Thus, angle D generally represents the degree of tape rule housing assembly rotation (with respect to the horizontally extending surface) required to achieve maximum standout for a given length of extended tape.

The comparison of the prior art and the present invention given inFIG. 9indicates that the maximum prior art arcuate length-out that could be achieved with a one inch wide blade was approximately nine feet. Because of the relatively shallow (relative to the present invention) cross-sectional blade height H of approximately 0.21 inch (not shown inFIG. 9) typically used in prior art one inch blades and because of the relatively high thickness of the metal of the prior art blades (which thickness is required for the arcuate length-out to be achieved), however, the linear length-out B was approximately 93 inches. This results in a percent of linear to arcuate length-out of approximately 86 percent. It can be appreciated that the third embodiment of the prior art shown in the fourth through the sixth rows ofFIG. 9shows relatively little bending for seven feet of standout (96% linear to arcuate length-out), but that this embodiment bends a very large degree when two additional feet of the blade are extended. This high degree of arcuate bending of the 1 inch blade at standout lengths approaching 9 feet makes the task of measuring a large distance difficult for a single person using the prior art tape rule assembly. As indicated inFIG. 9, the present invention provides a rule assembly that can achieves seven feet to approximately 11 feet of arcuate length-out while maintaining the percent of linear to arcuate length-out in the approximate range of 99 percent to 98 percent. This greatly facilitates the task of measuring a length for the tape assembly user. Greater degrees of standout with a comparable percentage of linear to arcuate length-out can be achieved by making the blade wider. It is, for example, within the scope of the present invention to provide a blade width of 1.5 inches or greater.

It can be understood by one skilled in the art that the 1.25 inch blade width of a preferred embodiment of the assembly10allows the blade height H to be increased without increasing the overall blade curvature to a degree that would make reading the gradations and lettering printed on the concave surface of the blade16difficult. This construction results in a blade with relatively high height H that is also easy to read. (In contrast, one inch blades having a curve height of the extended blade of over 0.21 become very difficult to read and are thus not commercially practical.) Increasing the blade width of the blade of the present invention also allows the printing on the blade to be made larger, thus making measurements easier by making the blade easier to read. When the preferred 1.25 inch blade (flat width F) is in its concavo-convex cross-sectional configuration (FIG.7), the height H thereof, as mentioned above, is approximately 0.32 inch and the curved or arcuate width W is approximately 1.018 inches. This relatively wide width W of the extended blade also facilitates reading a measurement from the blade16.

The blade of the rule assembly10is thus able to achieve the approximately 11 feet of standout while improving the percent of linear to arcuate length-out relative to the prior art. This length of standout is achieved while the bottom surface of the housing is angled approximately 45 degrees with respect to the horizontal surface S (as indicated in the right most column ofFIG. 9) which is comparable to the three prior art rule assembly embodiments shown in FIG.9.

One skilled in the art will appreciate that when the rule assembly10is provided with a 33 foot long blade, a coil spring32must be provided to accommodate outward movement of the blade16to its fully extended position. It can be appreciated that it is desirable to construct a rule assembly10so that the housing assembly12is small enough and compact enough to fit easily in one hand of a user. Because the rule assembly10has a wide blade, the width of the housing assembly12is comparably wide. It is desirable to construct a retractable rule assembly10so that the height and length of the housing assembly12(also called the “footprint” of the housing assembly12) are as small as possible. Because both the spring32and the blade16can be quite long in some embodiments of the invention (up to approximately 33 feet of blade length, for example), the spring32must be carefully constructed so that it provides sufficient spring forced to retract the fully extended blade and yet fits within a housing assembly12having a footprint that is dimensioned to easily fit in a user's hand.

The coil spring is constructed of a coiled ribbon of metal (typically steel). The spring force provided by the spring is approximately directly proportional to the spring width and the spring thickness. A thick spring undesirably increases the height and length of the housing assembly12, however. It has been found that the most desirable construction of a rule assembly constructed according to the principles of the present invention has a coil spring that is relatively thin and relatively wide compared to prior art springs. Preferably the spring32of the rule assembly10has a width that is approximately 95 percent to approximately 120 percent of the width of the blade (for a given blade width in the broad range set forth above for the flattened blade). More preferably, the spring has a width that is approximately 100 percent to approximately 110 percent of the width of the metal ribbon of the blade, and is most preferably 100% of (i.e., equal to) the blade width (as shown in FIG.9). Because the spring width is relatively great, the spring can be made the same thickness as or thinner than the blade16. The reduction in the spring thickness relative to blade thickness (as compared to the prior art), allows the housing assembly12to be constructed so that it has a minimal footprint to provide a housing assembly12that can be easily gripped in one hand.

Typical springs used with prior art one-inch blades have a width that is less than the width of the blade, usually in the range of 0.8 to 0.89 inch.FIG. 9shows a typical value of 0.875-inch for the spring width for all three embodiments of the one-inch blades described in the figure. Prior art spring thickness ranges from 0.0051 to about 0.0060 inch. Generally, prior art spring thickness is approximately 0.0003-0.0006 greater than the blade thickness. Thus, prior art construction uses springs that are thicker and significantly narrower than the blade. It can be appreciated that although it is possible to use this prior art construction and the present invention, it is undesirable because the relatively thick spring of the prior art would result in a housing assembly footprint that is too large to fit comfortably within the average user's hand. Thus there is a need for a new spring construction that can be used with the blade16that will allow the footprint of the housing assembly to be made small to be comfortably grippable using one hand.

It can thus the understood that the relatively wide spring allows the thickness of the spring to remain relatively small and this allows the footprint of the housing assembly to be small enough to be easily gripped in a single hand of the most users. More specifically, preferably, when the spring width is approximately equal to the blade width, the spring32of the present invention is 0 percent to 10 percent thinner than the blade16. As another example, if the spring32is made one hundred twenty percent the width of the blade16, the spring32is preferably 0 percent to 25 percent of thinner than the blade. In terms of actual measurement, this means that typically the spring thickness is up to 0.0005 inch thinner than the thickness of the blade. Furthermore, because the spring of the present invention is made wide relative to the width of the blade, the overall length of the spring can be made shorter relative to the length of the prior art springs for comparable measuring blade16lengths. For example, a typical one inch wide, 25 foot long prior art blade has a spring that is approximately 240 inches in length; the length of a wide spring32constructed according to the principles of the present invention for the rule assembly10having a 25 foot blade is approximately 230 inches.

By increasing the spring width of the spring16, the thickness of the spring can be decreased and the length decreased while still providing sufficient spring force to retreat the blade without increasing the footprint of the housing assembly to an undesirable degree. Examples of specific housing assembly12heights for particular blade lengths will be considered below after other structural details of the construction of the rule assembly10are considered.

The housing assembly12is further constructed to easily and comfortably fit in a hand of the user because it optimizes the use of space within the housing assembly12to house the blade16, coil spring and other cooperating components. The details of the internal structure of the housing assembly12and the blade16mounted therein are shown inFIGS. 4-6and11. Preferably the housing assembly12and the reel14are constructed of a molded plastic. As best appreciated fromFIG. 6, the housing assembly12includes a pair of cooperating molded plastic housing members40,42. Each housing member40,42includes an end wall44,46, respectively, having a peripheral wall48,50, respectively, extending from a periphery thereof and terminating in a free edge52,54, respectively. The pair of cooperating housing members40,42are movable toward one another in an axial direction into cooperating relation to define the housing assembly (where “axial direction” refers to the direction of the axis of rotation of the reel defined by the spindle).

When the housing members40,42are fixed together in the assembled rule assembly10, the free edges52,54are interengaged as shown inFIG. 6. Aplurality of axially extending bolts58extend through one of the housing members42and threadedly engage the other housing member40(FIG. 11) at spaced positions adjacent the peripheral walls48,50. The housing members40,42are also fixed together by the threaded engagement of bolts68with the fixed reel spindle15. The axially extending spindle15is fix at a central portion of the housing assembly12. Specifically, the fixed spindle15has a noncircular interengaging recess-projection connection (shown in FIG.6and described below) at each end thereof generally with a central interior region62,64, respectively, of the end walls44,46of the housing assembly12. Each end of the fixed spindle15is interiorly threaded to threadedly receive the bolts68therein. The bolts68extend through central holes70,72formed in the respective adjacent end walls44,46of the housing assembly and threadedly engage internal threading73in each end of the spindle15. Each bolt68extends through a recess-projection connection, generally designated75, when each bolt68is disposed in a respective central hole70,72and threaded interior73. A metal clip77is secured to one side of the housing assembly by one of the blots68.

Preferably the fixed spindle15is constructed of a molded plastic or nylon. The construction of the recess-projection connections75between the ends of the spindle15and the walls44,46is shown in cross-section in FIG.6. Each recess-projection connection75is identical. Specifically, projections74having exterior noncircular cross-sections are integrally formed on the walls44,46and are received within recesses76having complementary non-circular interior cross-sections formed on each end of the spindle15. The noncircular interior and exterior cross-sections cooperate to present rotation of the spindle15with respect to the housing assembly12when the ends of the spindle15are mounted on the projections74in the assembled rule assembly10. Each end of the spindle15extends through a hole79of circular cross-section formed in opposite sides of the reel14. The portions of the spindle15that extend through the holes79in the reel14have circular exterior cross sections. A flange81on the spindle15engages an annular groove83in the reel14surrounding the hole79to guide the rotation of the reel on the spindle. Thus, the reel14is rotatably mounted on the spindle15for bidirectional rotational movement of the reel with respect to the housing assembly12. As can best be appreciated fromFIGS. 4 and 6, the spindle15is internally slotted to receive the one longitudinal end37of the spring32to thereby secure the one end37of the spring to the spindle.

The molded plastic reel14includes two reel members78,80(FIG.6). Reel member78includes the integral cylindrical wall portion28about which the blade12is wound. Reel member80is essentially disk shaped. Each reel member78,80includes an outwardly extending cylindrical wall portion88,90, respectively, formed around the hole79. An annular edge portion84on the wall portion82is received within an annular groove86formed within reel member80to help hold the reel14together. The abutting engagement of the wall portions88,90on the reel with the end walls44,46of the housing assembly12maintain the edge portion84within the groove86in the assembled rule assembly.

The housing members40,42include portions along the abutting free edges thereof52,54, respectively, of tongue and groove construction (FIG. 6) to help secure the molded housing members40,42of the assembled rule assembly10together. Specifically, at a top portion of the housing assembly12, a wall portion92formed on edge54is received within a groove94formed along a portion of the edge52; and an integral wall portion93formed on edge52is disposed in underlying, abutting relation to wall portion50of the housing member44. At a bottom portion of the housing assembly12, a wall portion95formed along a length of edge54is received within a recess97formed on a portion of the wall portion48of housing member40.

When viewed from the side elevational view, the housing assembly12includes only two corner portions (seeFIG. 4, for example), generally designated96,98. One corner96is adjacent the housing assembly opening22and the other corner portion98is at an opposite bottom end of the housing assembly12. The two blots58are positioned in the only two corner portions96,98, respectively, of the housing assembly12. Thus, it can be appreciated that the housing assembly12is secured together using threaded fasteners in only three locations (from the point of view of one looking at the side elevational view of, for example, FIG.4): at the opposite corners96,98(bolts58) at the bottom portion of the housing assembly12and in the center of the housing assembly12(bolts68). This use of the blots68on opposite ends of the reel spindle15allows the housing assembly12to be secured together without using any bolts in a peripheral top portion or portions of the housing assembly12.

This arrangement of the bolts helps reduce the size of the footprint of the housing assembly12to allow the housing assembly12for a 33-foot long blade constructed according to the principles of the invention to have up to 13 feet of blade standout, for example, to easily fit in a hand of a user. Specifically, it is within the scope of the invention to provide tape assemblies constructed according to the principles taught herein wherein the height (and length) of the housing assembly does not substantially exceed 3.65 inches for a blade length that is at most approximately 33 feet; wherein the height (and length) of the housing assembly does not substantially exceed 3.45 inches for a blade length that is at most approximately 30 feet; and wherein the height (and length) of the housing assembly does not substantially exceed 3.25 inches for a blade length that is at most approximately 8 meters.

As best appreciated fromFIGS. 3-4, because the housing assembly does not require bolts in the upper periphery of the housing assembly12, the top portions108of the housing assembly12can be made to have a relatively arcuate profile (FIG. 2, for example) that generally conforms to the profile of the reel, thus minimizing the footprint of the housing assembly12, eliminating corners in the upper portion of the housing assembly and providing a comfortable curved top surface to receive the palm of a user's hand. This arc-shaped upper surface of the housing assembly12also increases impact resistance of the housing member12in case the assembly10is dropped.

A peripheral portion of housing assembly12is provided with a rubber-like coating110around the gripped portion of the housing assembly12to provide increased frictional engagement between the housing assembly and a user's hand and to provide a relatively soft comfortable surface for the user's hand.

The housing assembly12includes a bottom wall109(FIGS. 4-5) having an exterior portion107at an end position adjacent the housing assembly opening22which projects below an exterior surface portion108extending therefrom toward an opposite end113of the bottom wall109to provide a finger grip enhancing configuration, generally designated119for a gripping hand of the user. More specifically, the bottom wall109(FIGS. 3-4) has a forward end portion107adjacent the housing assembly opening22and a rearward end portion113at the opposite end of the bottom wall109; the portion108of the wall109therebetween is generally recessed to provide the finger grip enhancing configuration119for the gripping hand of the user. This recessed area or gripping are119on the bottom of the housing assembly12is preferably completely covered with the overmoled rubber or rubber-like polymeric material. It can thus be appreciated that the housing assembly12is constructed to be easily held in one hand of a user such that the user's fingers engage the finger grip enhancing portion119and the user's palm and thumb are generally in overlying relation with a top portion of the housing assembly.

The housing assembly includes a fitment118(FIG. 11) which forms a part of the housing assembly opening22adjacent a convex side of the blade16. The fitment118is an essentially U-shaped structure having a transversely extending cross member115and two upstanding arms117extending upwardly from opposite sides of the cross member115. The cross member115defines the lower edge of the housing opening; a bottom surface170of the cross member115is flush with the adjacent surface portion107of the bottom wall109so that a bottom surface portion170of the fitment118forms part of the bottom surface of the housing assembly12adjacent the opening22. The fitment118is preferably an integral molded plastic structure. The fitment118is held within appropriately sized opposing recesses121,123(FIG. 11) formed in the respective housing members40,42and which recesses are disposed on opposite sides of the opening22when the housing members40,42are secured together. The cross member115of the fitment118has a plurality of tangentially extending, transversely spaced elongated ridges120which define surfaces125along the bottom of the opening22for engaging and supporting the convex side of the blade16extending tangentially from the reel14of the housing assembly opening22. Thus, the ridges120slidably engage the convex side of the blade16and provide a low friction engagement between the housing assembly12and blade16.

A holding assembly, generally designated to124, is constructed and arranged to be manually actuated to hold the blade16in any portion of extension outwardly of the housing assembly opening22and to release the blade16from any position in which it is held. The structure and operation of the holding assembly124is best appreciated from a comparison ofFIGS. 4-5. The holding assembly124includes a holding member126mounted on the housing assembly12for movement in opposite directions between a normally inoperative position (FIG. 4) and a holding position (FIG.5). It can be appreciated that the blade holding member126is an arcuate member that is movable along an arcuate path between the two positions as aforesaid. The holding member126has an interior free end portion128that is movable into wedging engagement with the tangentially extending portion of the blade16to engage and hold the blade against an interior holding structure130(FIG. 5) on the housing assembly12when the holding member126is in its holding position. The free end portion128includes a central recess129(FIG. 2, for example) that is described in detail below. The holding member126has an exterior thumb engaging portion132configured to be moved digitally to selectively move the holding member126from its normally inoperative position and its holding position. The exterior thumb engaging portion132is best seen inFIGS. 1-2.

Preferably the holding member126is an integral structure made of an appropriate durable flexible plastic. The thumb engaging portion132is connected by an integral outwardly extending neck portion134to an elongated arcuate flexible body portion133that terminates in the interior free end128. The outwardly extending portion134is slidably held within and guided by a slot136formed within a front part of housing assembly12by the members40,42. The movement of a lower portion of the holding member126is guided by a pair of tabs131integrally formed on respective housing members40,42(only one tab is shown in the figure). An integral locking structure138on the holding member126engages holding structure140(FIG. 5) integrally formed on the housing assembly12to releasably lock the holding member126in the holding position in wedging engagement with the blade16.

More specifically, to lock the blade16in a given position of extension, the user (while holding the blade16outwardly of the housing assembly12against the spring force of the coil spring32) slides the thumb engaging portion132downwardly with respective to the housing assembly12causing the locking structure138to slide over a ramped surface142on the holding structure140and causing the free end128to move in a locking direction with respect to the blade16. The flexible plastic locking structure138bends resiliently outwardly slightly as it passes over the holding structure140. After the free end128contacts the blade16, continued movement of the thumb engaging portion132in the locking (downward) direction thereafter wedges the free end128of the flexible body portion133against blade16to hold the blade16in place against the spring force of the coil spring32and moves the locking structure138into abutting engagement with a locking surface141on the holding structure140. The holding member flexes slightly as the free end128is wedged against the blade16. The abutting engagement between the locking structure138and the locking surface141locks the holding member126in its holding position. It can be understood fromFIG. 5that the blade16is held in an extended position (against the spring force of the coil spring32) between the free end128of the body portion133and the interior holding structure130by the downward force exerted by the wedged body portion133. The interior holding structure130(not visible in detail) is a series of longitudinally spaced, transversely extending ribs that are constructed and arranged to support the convex side of the blade16. When viewed from the point of view ofFIG. 5(i.e., on a transversely directed line of sight), the top surfaces not visible in the FIGS.) of the ribs cooperate to provide a generally downwardly sloped support (in a direction toward the opening22) for the blade16; and when viewed from the front, (i.e., on a longitudinally directed line of sight) the top surfaces (not visible in the figures) of each rib of the interior holding structure130are transversely spaced in a concave array to receive and support the convex side of the blade.

To release the blade16, the user pulls upwardly on the thumb engaging portion132which causes the locking structure138on the plastic holding member126to move resiliently outwardly and past the locking surface141to release the holding member126from engagement with a blade16. The holding member126resiliently returns to its normal arcuate shape. It can be appreciated fromFIG. 2that the recess129on the free end128of the holding member126defines two transversely spaced teeth147which have spaced arcuate side surfaces144sized in conform to the concave surface of the blade16to hold the same in locked position.

It can be understood that the use of the holding member126when a measurement is being taken is optional. When taking a measurement, the user typically holds the housing assembly12in one hand and manually pulls the blade16out of the housing assembly12with the other hand. When a sufficient length of blade16has been withdrawn from the hosing assembly12, the user can lock the blade16with respect to the housing assembly12using the holding member126to prevent the blade16from retracting back into the housing assembly12(under the spring force of spring32) when the user releases the blade16. When the measurement has been taken, the user simply releases the holding member126from holding engagement with the blade16by moving the free end128thereof out of wedging engagement with the blade16in the manner described above. If the holding member126is not used during the taking of a measurement, the user can simply hold the blade16with his other hand while the measurement is being taken or, alternatively, the hook member34can be placed in hooking engagement with the workpiece to hold the blade16outwardly of the housing assembly12in a controlled and steady manner against the spring force of spring32while the measurement is being taken.

When the blade16is released after taking the measurement, the spring32rotates the reel14with respect to the housing assembly12in a blade-winding direction to wind the blade16around the reel14. A relatively short free end portion of the blade16has a clear film158of plastic material adhered to the concave side thereof (FIG. 11) to protect the blade16while the same is out of the housing assembly12and while the blade16is being retracted under the spring force of the spring32back into the housing assembly12. Preferably the film is made of polyurethane and is adhered to the blade by an acrylic adhesive. It is also contemplated to use Mylar® and Nylon® to construct the film. Preferably the film has a thickness dimension within the range of approximately 0.006 inches to approximately 0.014 inches. It is within the scope of the invention to apply this film to the blade of any known tape rule assembly.

Preferably the self adhering film158is placed over several leading inches (preferably within a broad range of approximately 2 inches to approximately 12 inches) of the free end20of the blade16, including the portion of the blade on which the hook member34is disposed so that preferably the film goes under the hook member34all the way to the free end20of the blade16. More preferably, the film158is applied a length from the free end20of the blade16that is less than 10.5 inches; and most preferably, the length of the blade16from the free end thereof that is covered by the film158is approximately 6 incehs. It is generally desirable to have the film-covered portion end at approximately the point on the blade16where the volutes of the coiled blade are in overlying relation to one another when the blade16is in its fully retracted configuration. Typically in a tape rule assembly, the tape blade starts to warp on itself at approximately 9.5 inches when a typical reel size of approximately 2.9 inches in outer diameter is used in the construction. The film158is provided because most failures in a rule blade16occur within the first six inches of the free end of the blade16from cracks or tearing. The cracks or tearing occur because when the blade is wound back around reel under the spring force of the coil spring, the free end of the blade tends to “whip” as it enters the opening22, causing the last several inches of the blade16to hit against the housing assembly12. This can cause cracking or breaking of the free end of the blade16over time. The protective film158prevents these cracks and tears and other damage to the blade16associated with blade whipping.

The free end of the blade16is frequently handled by the user and this handling can over time cause the numbering and markings on the concave side of the blade16to wear off or become difficult to read. The film158prevents this damage because it covers the numbering and markings on the free end of the blade and thereby protects the same from being worn off.

The construction of the hook member34and the manner in which it is disposed on the free end20of the blade16is best seen inFIGS. 1-4,11. Preferably the end hook member34is formed of sheet metal of predetermined thickness and includes a concavo-convex mounting portion150(FIG. 11) having a U-shaped hook portion152bent at a generally right angle from an end of the concavo-convex mounting portion150. The hook member34is mounted on the free end20of the blade16with the mounting portion150thereof secured in limited sliding engagement with a concave side of the free end20of the blade16and in overlying relation thereto.

More specifically, the mounting portion150is provided with large holes167(FIG. 4) and a plurality of rivets169extend through the holes167to slidably mount the hook member34to the blade16for limited longitudinal relative movement between the hook member34and the blade16(i.e., the diameter of each hole167is greater than the diameter of the associated rivet169by an amount approximately equal to the desired amount of hook movement). The limited sliding engagement allows the blade16to be measured externally from an external surface161of the U-shaped hook portion or internally from an internal surface163of the U-shaped hook portion152. In other words, the sliding movement of the hook member34allows an accurate measurement to be taken with either surface161or163in abutting relation with the workpiece; the holding member34slides longitudinally with respect to the blade16a distance approximately equal to the thickness of the hook portion152(where the thickness is measured from surface161to surface163) so that a measurement taken with either surface161or163in abutting engagement with the workpiece will yield an accurate measurement.

The U-shaped hook portion152includes a bight section160extending transversely downwardly from a convex side of the free end of the blade16and spaced leg sections162extending beyond transversely spaced corners171of the free end of the blade. The bight section160of the hook portion152of the hook member34provides an under-catch structure that can hookingly engage a workpiece to facilitate extension of the blade16and to temporarily secure the blade to the workpiece while a measurement is being taken. As can be appreciated fromFIG. 11, the leg sections162extend beyond the longitudinally extending edges of the blade16to provide a side catch surface on each side of the blade that16can be used to hook the blade to an object or workpiece. The side catch structure provided by the legs162can function to secure the free end of the blade16during a measurement. The side catch structure provided by the leg sections162also allow the blade16to be easily and steadily held in a tilted position relative to a surface of the workpiece, thereby allowing a longitudinally extending edge of the blade16to be held against the workpiece. More specifically, when the convex side of the blade16is against the workpiece, the longitudinal edges are normally spaced from the surface because of the concavo-convex cross-section of the blade16. The legs162of the hook member34provide a side catch that can be hooked over an edge of the workpiece to allow the user to hold steadily a longitudinal edge of the blade very close to or directly against the workpiece when the convex side of the blade16is against the workpiece, which facilitates reading a measurement. This is helpful in taking measurements because the curve height H of the cross section is preferably approximately 0.32 of an inch so that the curve height of the blade is relatively high.

The upper portions of the leg sections162extend generally upwardly and outwardly above the concave side of the blade16(FIG. 11) to provide structure above the concave surface of the blade16to hookingly engage the workpiece to facilitate extension of the blade16and to hold the free end of the blade16while a measurement is being read. For example, the blade16can be placed against a workpiece such that the concave side of the blade16is facing the workpiece and such that the opposite longitudinal edges of the blade16abut a surface on the workpiece at a point where they measurement is to be read. When the blade16is in this position, the upwardly extending protoins of the legs162on the hook member34can be used to hold the free end20of the blade16against the workpiece.

It can also be appreciated fromFIGS. 1-2that the hook-shaped portion152of the hook member34provides an aesthetically pleasing “face” appearance on the front of the rule assembly10when the blade16is in the fully retracted position. Transversely spaced corners171on the free end20of the blade16are mitered (FIG. 4) inwardly from opposite longitudinal edges of the blade16; the leg sections162of the hook member34extend beyond the mitered corners171on the opposite edges of the end20of the blade16. The mitered corners171prevent the user from being scratched or cut by the corners on the end of blade16. Preferably each corner171is mitered inwardly from the respective opposite longitudinal edge starting at a distance of approximately 3/32 of an inch from the free end of the blade16.

Preferably, the housing opening22has a height dimension that extends the height dimension of the hook member mounting portion150and its connection with the free end of the blade16by an amount which is at least approximately equal to the amount the hook portion152of the hook member34extends below a bottom end surface170of the housing assembly12at the housing opening22when the hook member34is at the housing opening22(FIG.11). This height of the opening22is provided to prevent possible damage to the hook member34when the blade16is fully retracted and the hook member34is impacted (by dropping or the like) in a direction that tends to move the hook member34upwardly with respect to the opening22.

The details of the construction of the housing opening22can be appreciated fromFIGS. 4 and 11. It can be appreciated that the axially extending fastener58in the corner96must be spaced upwardly in the housing assembly12a sufficient distance to allow the opening22to have sufficient height to protect the hook member during impact. The location of this fastener58in the corner96is restricted by the dimensions of the corner96. Specifically, the arcuate path followed by the arcuate holding member126between its inoperative position and its blade holding position defines the interior extent of the bottom corner96of the housing assembly and a lower front wall portion200at the front of the housing assembly12generally defines the forward extent of the bottom corner96. Thus, it can be appreciatedFIG. 4that the tape assembly10must be constructed so that the holding member126and the front wall portion200cooperate to allow the fastener58to be positioned upwardly relative to the housing assembly12sufficiently to allow the housing opening22to have the height as aforesaid. The heights of prior art housing openings are generally restricted by the position of a fastener over the housing opening. Prior art housing assembly construction prevented the fastener from being spaced upwardly far enough to provide an opening having a height dimension large enough to protect the hook member from impact damage as aforesaid. The present invention overcomes this problem by constructing the lower front wall portion200of the housing assembly so that it is essentially flush with the central portion204of the front of the housing assembly. By positioning the lower front wall portion200essentially flush with the central front wall portion204, the associated axially extending fastener58can be moved upwardly sufficiently to allow the housing assembly opening22to have a height as recited sufficient to protect the hook member in the event of impact. Specifically, the increased housing opening height allows the bottom edge177to move upwardly to a position flush with the bottom surface170of the housing assembly12adjacent the opening22before the mounting portion150of the hook member34impacts any downwardly facing surfaces on the housing assembly12.

It can be appreciated fromFIG. 4that in the exemplary embodiment of the tape assembly10, the interior free end128of the holding member126is disposed generally above the mounting portion150of the hook member34when the hook member34is at the opening22. The recess129is provided in the free end128of the holding member126so that if the hook member34is caused to move upwardly in the opening22because of an impact, the free end128of the holding member126does not present upward movement of the hook member34in the opening22so that the bottom edge177can move upwardly to a position flush with exterior housing assembly12bottom end surface170. More particularly, the central recess129is of a width to operatively accommodate the width of the hook member mounting portion150. Therefore when the hook member34is forced upwardly in housing opening22by an impact, the mounting portion150moves upwardly into the recess129, thereby allowing the bottom edge177of the hook member34to move upwardly sufficiently so that it is flush with the bottom end surface170of the housing assembly adjacent the opening22. If the recess129were not provided, the free end128of the holding member126could possibly restrict the upward movement of the mounting portion150so that an impact on the hook portion152of the holding member34could bend of the hook member34against the holding member126. The recess129precludes the possibility of this type of damage to the hook member34by allowing the holding a member126to move upwardly in the housing assembly opening22at least far enough to allow the bottom edge177to move flush with the surface170at the bottom end of the housing assembly12.

The opening22is constructed to allow the hook member34to move upwardly in the opening22until the upper edges of the mounting portion150impacts structure at the top of the opening22. More specifically, it can be appreciated fromFIGS. 4 and 11that the lateral edges of the mounting portion150adjacent the hook portion152provide upwardly facing surfaces206which engage one or more downwardly facing surfaces208defining the housing opening22to limit the upward movement of the hook member34within the opening22. The lateral longitudinally extending edges210of the blade16extend upwardly and outwardly beyond the upwardly facing surfaces206of the hook member mounting portion150, but the edges210do not limit the upward movement of the hook member34in the opening22. This is because when the hook member34moves upwardly in the opening22during impact, the edges210of the blade16engage the downwardly facing housing opening surfaces208and deflect resiliently outwardly before the mounting portion150of the hook member34engages of the upwardly facing surfaces206. In other words, in the exemplary embodiment of the tape assembly10shown, the concavo-convex cross sectional curve height of the blade16is such that the edges210are normally above the upwardly facing surfaces206on the mounting structure150of the hook member34. When the hook member34at the opening20is moved upwardly with respect to the housing assembly opening22by an impact, the edges210of the blade16impact the upper portion of the opening22first, causing the edges210of the blade to flex outwardly in opposite directions, slightly flattening the blade16to a degree sufficient to allow the mounting portion150of the hook member34to move toward and into contact with the downwardly facing surfaces208at housing opening22. When the upwardly facing surfaces206on a mounting portion abut the downwardly facing surfaces208at the opening22, the hook member34reaches the upper limiting position of its upward movement in the housing opening. This upper limiting position is usually not reached, however, because preferably the tape assembly10is constructed and arranged such that the bottom edge177of the hook member34moves upwardly to a position flush with the surface170on the bottom of the housing assembly12before the upwardly facing surfaces206on the hook member34impact the downwardly facing surfaces208on the housing assembly12. When the bottom end177of the hook member34is flush with the bottom end surface170of the housing assembly, the hook member34is protected with further impact, thereby presenting damage to the hook member34.

It can be understood that the coiled blade16has a tendency to unwind and return to a straight (in the longitudinal direction), extended configuration of concavo-convex cross-section. This tendency provides a downward force on the free end20of the fully retracted blade16with respect to the housing assembly opening22that maintains the extended portion of the fully retracted blade16against the bottom of the housing assembly interior at the opening22and thereby normally maintains a portion of the hook member34of the fully retracted blade16below the bottom surface170of the exterior of the housing assembly12. This allows the tape assembly user to easily hook the hook member34on a structure such as a workpiece because a portion of the hook member34is normally below the surface170.

One skilled in the art will understand that the embodiment of the tape rule assembly10shown in the figures and described above is exemplary only and not intended to be limiting. It is within the scope of the invention to provide any known tape rule assembly with any or all of the features of the present invention. For example, the clear film of plastic material can be applied to any known tape rule assembly. Similarly, an end hook member constructed according to the principles of the present invention can be applied to any known rule assembly.

The features of the housing assembly including the molded plastic construction, the shape of the housing, the use of relatively few bolts, the elimination of bolts in the upper portion of the housing assembly, the manner in which the spindle is mounted therein, the height dimension of the housing assembly opening relative to the dimension of the downwardly extending portion of the hook member on the free end of the blade and construction of the finger engaging portion on the bottom surface of housing assembly can be used separately or in combination on any existing tape rule assembly.

Similarly, the geometry of the cross-section of the blade and the general teachings of the dimensions and construction of the blade and coil spring can be used on any existing tape rule assembly.

The construction of the fitment, including the construction of the tangentially extending transversely spaced elongated ridges thereof can be used on any known tape rule assembly. It can also be understood that even though it is preferable to construct the tape rule assembly having the ridges on a separate fitment, it is contemplated to provide an embodiment of the tape rule assembly in which the ridges are formed integrally on the housing members of the housing assembly. It can also be appreciated that it is contemplated to use any of the aforementioned features singly or in any appropriate combination on a tape rule assembly that has a spring-powered retractable blade or, alternatively, on any tape rule assembly in which the blade is manually retracted.

It can be appreciated by one skilled in the art that it is within the scope of the present invention to apply the teachings presented herein to construct a tape measure of a wide range of sizes and that it is not intended to limit the invention to the embodiments or to the specific measurements or ranges of measurements presented herein. It can be understood, for example, that it is within the scope of the invention to construct a retractable tape measure assembly that includes a one inch wide (i.e., flattened width) tape blade with increased standout. Because it is contemplated to provide tape measure assemblies with the features of the invention enumerated herein separately or in any combination, it can be understood that a wide range of tape measure assemblies having one inch wide blades could be constructed. More specifically, a tape measure assembly having one inch wide blade could include for example, a cross-section blade geometry; a small footprint housing; a hook member; a protective film; a housing opening height and hook member size; and/or a fitment with transversely extending ribs all as described above in any combination.

It will thus be seen that the objects of the present invention have been fully and effectively accomplished. It will be realized, however, that the foregoing specific embodiments have been shown and described for the purposes of illustrating the functional and structural principles of the present invention and is subject to change without departure from such principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims.