Patent Description:
Tape measures conventionally include a retractable tape having measuring indicia thereon that is spring biased into a housing. A front of the tape commonly includes a hook that provides a surface to engage and fix the end of the tape against a point to be measured from, so the measurement can be made from the hook to a position on the tape indicated by the measuring indicia. The housing often has a lock mechanism that allows the tape to be locked into a certain position relative to the housing (e.g., locked into an extended position, preventing the spring bias from retracting the tape into the housing). An example of such a measuring tape can be found in <CIT>. Examples of punch type rivet fastening elements can be found in <CIT>and <CIT>.

Among other things, the present application relates to various improvements to tape measures, including strengthening the front of the tape to prevent separation of the end hook from the tape blade, either through impact of the hook against the housing of the tape due to excessive retraction under the spring force, impact against the hook, or so on.

The problems are solved by a measuring tool according to claim <NUM> and a method according to claim <NUM>.

In one embodiment of the invention, the structural components illustrated herein are drawn to scale. In addition, it should be appreciated that structural features shown or described in any one embodiment herein can be used in other embodiments as well. As used in the specification and in the claims, the singular form of "a", "an", and "the" include plural referents unless the context clearly dictates otherwise.

Features of tape measures in accordance with one or more embodiments are shown in the drawings, in which like reference numerals designate like elements. The drawings form part of this original disclosure in which:.

Tape measure blades are usually formed of metal, and have measurement indicia and other coatings provided for color, ink wear resistance, and overall abrasion resistance. In some embodiments, a polymer coating is provided that is usually thick relative to a metal substrate of a blade. Such thick coatings may require consideration when designing other aspects of a tape measure (e.g., how long the tape may be, the size and arrangement of components within a tape measure housing, etc.) Such coatings or similar appliques (e.g. reinforcements, such as of metal) are usually thicker near the free end of the blade, adjacent to the hook, to prevent damage at those points of the blade, in particular where the hook is attached to the blade through rivets or other fasteners extending through the blade. Even with the thick coatings, typical blades may tend to weaken, kink, crack, or break at the attachment point between the blade and a blade hook, especially after prolonged use, or improper use such as uncontrolled retraction of the blade.

<FIG> illustrate a self-retracting tape measure <NUM>. In an embodiment, as shown in <FIG> (perspective view) and 1B (cross-sectional view), the tape measure <NUM> includes an elongated tape measure blade <NUM> wound on a reel <NUM> that is rotatably mounted in a housing <NUM>. The blade <NUM> is extendable through an opening <NUM> in housing <NUM>. Blade <NUM> has a proximal end <NUM> that remains within the housing <NUM>, and a distal end <NUM> that has a hook <NUM> coupled thereto. Tape measure <NUM> also includes a spring <NUM> within housing <NUM> configured to rotate reel <NUM> in housing <NUM> in a direction to wind up blade <NUM>. In an embodiment, the end <NUM> of blade <NUM> terminates in a hook-like structure <NUM> that engages a first longitudinal end <NUM> of spring <NUM> to couple end <NUM> of blade <NUM> to spring <NUM>. In some embodiments, reel <NUM> includes two reel members <NUM> (and another corresponding reel member on an opposite side of reel <NUM>) that provide circular side walls on sides of spindle <NUM> about which blade <NUM> is wound. In an embodiment, spindle <NUM> is internally slotted to receive one end <NUM> of spring <NUM> to secure end <NUM> of spring <NUM> to spindle <NUM>.

In some embodiments a lock <NUM> may be provided in the tape measure <NUM> and may be configured to be actuated to hold blade <NUM> in any position of outward extension (e.g., moving the hook <NUM> away from housing <NUM>, such as is shown in <FIG>). In an embodiment the lock <NUM> may comprise a slide lock such as that illustrated, while in other embodiments spring biased locking mechanisms or other such mechanisms may be utilized.

In some embodiments, blade <NUM> may comprise a ribbon of metal (e.g., steel) and one or more surfaces of blade <NUM> may include measurement indicia thereon. The measurement indicia may include measuring lines, digits, and/or other indicia for measuring lengths and/or distances, in one or more scales. In some embodiments the blade <NUM> may be associated with a digital encoder configured to provide a digital determination of the amount of extension of the hook <NUM> relative to a portion of the housing <NUM>.

As shown in <FIG>, hook <NUM> is coupled to end <NUM> of blade <NUM> with a mounting portion <NUM> of the hook <NUM> engaging a first (e.g., concave or upper as described below) side <NUM> of end <NUM> of blade <NUM>. In some embodiments, mounting portion <NUM> is provided with holes <NUM>, described in greater detail below. One or more fasteners, such as rivets <NUM>, may extend through holes <NUM> to mount hook <NUM> to blade <NUM>. In some embodiments, hook <NUM> and/or mounting portion <NUM> may be similar to and/or the same as a hook and/or mounting portion described in <CIT>.

<FIG> illustrates blade <NUM> in a partially extended position <NUM>, so that hook <NUM> extends forward from the housing <NUM>. Blade <NUM> is generally movable between a fully retracted position (e.g., as shown in <FIG> and <FIG>) and a fully extended position (not shown). It can be appreciated from <FIG>, <FIG>, and <FIG> (and the additional description below) that as blade <NUM> is unwound from reel <NUM>, spring <NUM> is wound more tightly around the reel spindle <NUM>. This winding of spring <NUM> around spindle <NUM> stores energy in spring <NUM> to provide spring powered rewinding of blade <NUM> around reel <NUM> when the extended blade <NUM> is released (either by hand, or when a lock such as lock <NUM> is disengaged. As may also be appreciated from the side view of <FIG>, the blade <NUM> may generally have a curved shape when not flattened inside the housing when the blade <NUM> is retracted, and as such, when the tape measure <NUM> is viewed from a side when the blade <NUM> is extended, a second (e.g., convex or lower) side <NUM> of the tape blade <NUM> may be seen, obscuring the mounting portion <NUM> of the hook <NUM> and the top of the rivets <NUM>.

As discussed herein, an aspect of the present disclosure includes a method of creating a hole in a tape blade, such as the holes <NUM> in the blade <NUM>, so as to create a secure connection region for a fastener such as the rivets <NUM> to extend therethrough. In particular, as shown in <FIG>, formation of the holes <NUM> in the end <NUM> of the blade <NUM> is formed through a friction drilling process, where friction drilling flows substrate material of the blade <NUM> downward to reinforce the hole <NUM>. Accordingly, as discussed herein, a bead of the substrate material may reinforce the hole <NUM> and reduce tearing of the blade <NUM>.

As shown in <FIG>, in an embodiment the blade <NUM>, or stock material that may eventually be formed into the blade <NUM>, may be provided so that a hole such as the hole <NUM> may be formed therein. In some embodiments, a pilot hole 166A may initially be punched through the blade at a hole axis A. In an embodiment, the hole axis A may extend perpendicular to a length of the blade <NUM> as it extends along a flat surface. In an embodiment the pilot hole 166A may be punched from the top surface <NUM> to the bottom surface <NUM> of the blade <NUM>, while in another embodiment the pilot hole 166A may be punched from the bottom surface <NUM> to the top surface <NUM>. In other embodiments other mechanisms for making the pilot hole 166A may be utilized, including but not limited to drilling and/or cutting the pilot hole 166A out of the blade <NUM> at the hole axis A. In an embodiment the formation of the pilot hole 166A would be through a method that creates a smooth edge without stress risers, and as such punching or drilling the pilot hole 166A may be preferable to other mechanisms of forming the pilot hole 166A, such as through plasma cutting. It may be appreciated that the size of the pilot hole 166A may depend on a desired size (e.g., diameter) of the fastener to ultimately be inserted therein, such as the diameter of the rivet <NUM>. It may also be appreciated that the desired amount of material available for further steps in creation of the hole <NUM> described below may also guide an appropriate size for the pilot hole 166A. In one embodiment, the pilot hole 166A may have a diameter of approximately <NUM>. As the pilot hole 166A might not be utilized in some embodiments, it may be appreciated that in embodiments utilizing the pilot hole 166A, the pilot hole 166A may be any appropriate size that will be smaller than the ultimate hole <NUM> created through further processing.

It may be appreciated that creating a pilot hole 166A prior to further processing of the hole <NUM> may reduce shear stress during the further processing of the hole <NUM>, and may maintain hook accuracy for appropriate positioning of the hook <NUM> relative to the blade <NUM> (as such positioning is important for accuracy of measurements relative to an innermost and/or outermost face of the hook <NUM>). It may also be appreciated that the pilot hole <NUM> may produce a more consistent and smoother vertical wall of blade material during the further processing of the hole <NUM>, as described below, or may determine the size of the vertical wall produced during the further processing, allowing creation of a vertical wall of a desired size for such further processing. It may be appreciated that in some embodiments, the larger a pilot hole 166A, the more consistently it may be formed in a blade <NUM> and across a production run of blades <NUM>, while the smaller the pilot hole 166A, the greater a vertical wall would be formed. As such, in an embodiment the pilot hole 166A may be approximately <NUM>-<NUM>% the size of the final diameter hole for production.

Turning to <FIG>, according to the invention, a hole 166B is formed by friction drilling the blade <NUM> at the hole axis. A through a pilot hole 166A, wherein such pilot hole 166A may be larger than an initial point of a friction drilling bit used to create the hole 166B at the hole axis A. It may be appreciated that in an embodiment the diameter of the hole 166B may be dictated by a desired size of the fastener to ultimately be inserted therein. Accordingly, in some embodiments, the diameter of the hole 166B may be approximately between <NUM> and <NUM> in diameter. In an embodiment, the hole 166B may be approximately <NUM> in diameter. As shown, friction drilling of the hole <NUM> creates a protruding wall <NUM> extending from the blade <NUM>. According to the invention, the wall <NUM> extends from the second side <NUM> of the blade <NUM> to a plane of protrusion extension B by a length C, as discussed in greater detail below. It may be appreciated that in some embodiments the difference between the diameter of the pilot hole 166A and the diameter of the friction drilled hole 166B may dictate the amount of material that protrudes through, and thus the length C of the protruding wall <NUM>. In other embodiments, other ways of controlling the length C of the protruding wall <NUM> may be utilized, such as by cutting, shaving, and/or sanding the protruding wall <NUM> after formation through the friction drilling. According to the invention, the hole 166B is made into the pilot hole 166A. In examples not covered by the scope of the claims where no pilot hole 166A would be formed, the hole 166B formed by friction drilling may be the first penetration into the blade <NUM>, which may require such other mechanisms of controlling the length C of the protruding wall <NUM>, which may determine the curl and overall diameter resulting from further processing of the protruding wall <NUM>, as described in greater detail below. It may be appreciated that in such examples lacking the pilot hole 166A, if the hole 166B is large, the length of the protruding wall <NUM> may be trimmed to a desired size prior to further processing such at that described below.

In an embodiment the friction drilling may be approximately <NUM>,<NUM> RPM drill rotation speed at <NUM> per second vertical movement along the hole axis A. In some embodiments, the friction drilling may comprise continuous rotation with one motion down, and one motion for retraction, while continuing to rotate so as to not bind with moved material. In other embodiments, the speeds may vary during the friction drilling, or the friction drilling may comprise a plurality of up and down motions to create the hole 166B. In some embodiments, the friction drilling rotation speed may be approximately between <NUM>-<NUM> RPM, while the vertical movement along the hole axis A may be approximately between <NUM> - <NUM> per second. For example, in some embodiments, the friction drilling rotation speed may be approximately <NUM>,<NUM> RPM with vertical movement of approximately <NUM> - <NUM> per second. It may be appreciated that the speeds may vary depending on the material of the blade <NUM>, the feed rate, the drill size and shape, and other considerations across various embodiments. In an embodiment the length C of the protruding wall <NUM> formed by the friction drilling may be approximately <NUM>× -<NUM>× the average thickness of the remainder of the blade <NUM> (e.g., the thickness F described with reference to <FIG> below). In an embodiment, the length C may be approximately 4x the average thickness of the remainder of the blade <NUM>, such that a vertical measurement between the upper surface <NUM> and the plane B is approximately 5x the average thickness of the remainder of the blade (e.g., where the blade is generally <NUM> thick, such vertical measurement would be approximately <NUM>). In other embodiments the length C that the protrusion wall <NUM> extends may as formed through the friction drilling may be approximately between <NUM> and <NUM>.

Following creation of the protruding wall <NUM> by friction drilling, the protruding wall <NUM> may then be rolled or otherwise pressed against the second side <NUM> of the blade <NUM> to form a bead <NUM> surrounding a reinforced hole 166C. In an embodiment the bead <NUM> may extend from the second side <NUM> of the blade <NUM> to a plane of bead extension D by a length E. In an embodiment the bead <NUM> may be formed by rolling the protruding wall <NUM> with a die set. Other mechanisms of forming the bead <NUM> from the protruding wall <NUM> are also possible, including but not limited to heat melting the protruding wall <NUM>, using a laser melting or forming the protruding wall <NUM>, using rollers to shape the protruding wall <NUM>, or so on.

It may be appreciated that an excessive size of protruding wall <NUM> created by the friction drilling may create an uncontrollable bead <NUM> which may mushroom outward rather than forming a nearly closed loop against the second side <NUM>. Accordingly, in some embodiments, the length E that the bead <NUM> extends below the second side <NUM> of the blade <NUM> may be approximately between 1x and 2x as thick as the average thickness of the remainder of the blade (i.e. the thickness F as shown in <FIG>). It may be appreciated that in an embodiment the depth of the reinforced hole 166C may be a length G, which may be thicker than a thickness G of the remainder of the blade <NUM> by the length E. In some embodiments, the length E that the bead <NUM> extends below the second side <NUM> may be thicker than the average thickness F of the remainder of the blade <NUM>. Regardless, it may be appreciated that the length of the depth G of the reinforced hole 166C is greater than the thickness F of the remainder of the blade <NUM>. In some embodiments, the average thickness F of the blade <NUM> may be approximately between <NUM> and <NUM>, including in an embodiment being approximately <NUM> thick. As such, in some embodiments, the length E that the bead <NUM> extends below the second side <NUM> may be approximately between <NUM> and <NUM>.

It may be appreciated that while in the illustrated embodiments the hole 166B is formed from the first side <NUM> into the second side <NUM> such that the protruding wall <NUM>, and thus the bead <NUM>, are located adjacent the second side <NUM> as described relative to the tape blade <NUM> of the tape measure <NUM> above, in other embodiments the drilling may be reversed such that the bead <NUM> ultimately is formed on the concave first side <NUM> of the tape blade <NUM>.

As shown in <FIG>, in an embodiment the reinforced hole 166C may be the same as the hole <NUM> described with reference to <FIG> above, ready for receiving the holes 150a of the mounting portion <NUM> of the hook <NUM> adjacent thereto, with the rivet <NUM> secured through the aligned holes 150A of the mounting portion <NUM> and the hole <NUM> of the blade <NUM>, crimped over the bead <NUM>. As shown, the hole 150A of the mounting portion <NUM> may be larger than the hole <NUM> that is firmly filled by the rivet <NUM>, so that the hook <NUM> (and mounting portion <NUM>) may move laterally relative to the blade <NUM>, so that the hook <NUM> may move to account for the thickness of the hook <NUM> depending on whether an inside or outside measurement is being taken. In other embodiments the mounting portion <NUM> may be firmly fixed to the blade <NUM> by the rivet <NUM> or other appropriate fastener, and in some such embodiments other mechanisms for accounting for inside or outside measurements by the hook <NUM> may be utilized. As further shown in an embodiment a gap is provided above the mounting portion <NUM> and a head of the rivet <NUM>, which may facilitate attaching hook attachments such as magnets, hook extenders, or other appropriate hook accessories. Again, while the illustrated embodiment in <FIG> illustrates a rivet, it may be appreciated that other fasteners such as threaded fasteners such as screws or bolts, or other appropriate fasteners, may be secured through the reinforced hole <NUM> over the bead <NUM>.

According to the invention, the hole described herein is formed from friction drilling. In examples not covered by the scope of the claims, other mechanisms for forming the protrusion of blade material may be understood, including but not limited to additive deposition of blade material (e.g., laser deposition) to form either the vertical wall <NUM> or the bead <NUM> directly. For example, the blade may be positioned on a mold so that additive deposition of blade material forms a desired shape of bead <NUM>. Aspects of such localized additive deposition of blade material, and other teachings implementable with the teachings of this disclosure, may be understood from <CIT>, entitled "Self-Retracting Tape Rule".

While the tape measure illustrated herein is shown as a spring retractable short tape measure, the tape measure hook reinforcement discussed herein may be implemented with other types of measuring instruments utilizing an end hook, including but not limited to long-tapes (e.g., manually retractable with a reel). It may further be appreciated that the components described herein may be of different constructions or configurations, including but not limited to one or more being comprised of different material choices. For example, the components described herein may each be constructed from a variety of materials, including but not limited to one or more plastics, metals, rubbers, elastomers, or any other appropriate material choice. For example, in an embodiment one or more of the components may be formed of aluminum (e.g., machined aluminum), iron (e.g., steel), or any other appropriate material. In some embodiments, the material choices may differ from component to component.

Claim 1:
A measuring tool (<NUM>) comprising:
an end hook (<NUM>) having a mounting portion (<NUM>);
a blade (<NUM>) having a length and a width, the length being greater than the width;
a hole (<NUM>) extending through the blade (<NUM>) along a hole axis (A), near a first end of the blade (<NUM>);
a fastener (<NUM>) extending through the hole (<NUM>) and securing the blade (<NUM>) to the mounting portion (<NUM>) of the end hook (<NUM>);
wherein the blade (<NUM>) generally has an average first thickness along the length of the blade (<NUM>); and
characterized in that the hole (<NUM>) formed in the blade (<NUM>) is created by friction drilling through a pilot hole (166a), which causes downward flows of blade substrate material to create a protrusion of blade material extending from the blade (<NUM>) and give the hole a depth of a second thickness;
wherein second thickness is greater than the first thickness.