阅读说明：本技术 包括端部保护膜的具有尺条的卷尺 (Tape measure with tape blade including end protective film ) 是由 A·A·坎加尔 C·D·罗瑟 于 2020-04-30 设计创作，主要内容包括：示出了包括长形尺条的卷尺。该卷尺包括相对较短的聚合物保护膜,该聚合物保护膜联接到该尺条的与该尺条的钩端相邻的端部。(A tape measure comprising an elongate blade is shown. The tape measure includes a relatively short polymeric protective film coupled to an end of the blade adjacent the hook end of the blade.)

1. A tape measure comprising:

a housing;

a spool rotatably mounted within the housing;

an elongated blade coiled around the reel, the elongated blade having an inner end coupled to the reel and an outer end extending out of the housing;

a hook assembly coupled to an outer end of the elongated blade; and

a retraction system coupled to the reel, wherein the retraction system drives the elongated blade to rewind onto the reel;

wherein, this microscler chi strip includes:

an elongated metal core having an upper surface and a lower surface, wherein the upper surface includes a concave curve and the lower surface includes a convex curve;

an upper polymer coating covering at least a portion of the upper surface of the elongated metal core;

a lower polymeric coating covering at least a portion of the lower surface of the elongated metal core;

an ink layer forming a series of measurement indicia and located between the upper surface of the elongated metallic core and the upper polymer coating; and

a protective film coupled to an outer surface of the lower polymer coating adjacent an outer end of the elongated blade via an adhesive, the protective film having a length less than 20% of an overall length of the elongated blade.

2. The tape measure of claim 1 wherein the protective film has a length of 2 inches to 12 inches.

3. The tape measure of claim 1 wherein the hook assembly includes a hook tab that overlaps a portion of the protective film.

4. The tape measure of claim 1 wherein the average thickness of the protective film is between 0.14mm and 0.25 mm.

5. The tape measure of claim 1 wherein the protective film comprises a transparent PET material.

6. The tape measure of claim 5 wherein the elongated metallic core comprises a steel material having a hardness of 45-60RHC, the upper and lower polymer coatings comprise nylon, and the protective film has a thickness of between 0.03mm and 0.3 mm.

7. The tape measure of claim 6 wherein the upper and lower polymer coatings comprise nylon paint having a thickness between 0.01mm and 0.03 mm.

8. The tape measure of claim 1 wherein the elongate blade is less than 50 feet in length.

9. The tape measure of claim 1 wherein the peel strength between the protective film and the outer surface of the lower polymer coating is greater than 9 pounds.

10. A tape measure comprising:

a housing;

a spool rotatably mounted within the housing;

an elongated blade coiled around the reel, the elongated blade having an inner end coupled to the reel and an outer end;

a hook assembly coupled to an outer end of the elongated blade; and

a retraction system coupled to the reel, wherein the retraction system drives the elongated blade to rewind onto the reel;

wherein, this microscler chi strip includes:

an elongated metal core having an upper surface and a lower surface, wherein the upper surface includes a concave curve and the lower surface includes a convex curve; and

a protective film coupled to the elongated metal core via an adhesive, the protective film having a length less than a total length of the elongated blade, wherein a peel strength between the protective film and an adjacent surface of the elongated blade is greater than 9 pounds.

11. The tape measure of claim 10 further comprising: a polymer coating coupled to the elongated metal core, wherein the protective film is directly coupled to an outer surface of the polymer coating via the adhesive.

12. The tape measure of claim 11 wherein the protective film has a length less than the length of the polymer coating.

13. The tape measure of claim 12 wherein the polymer coating is coupled to a lower surface of the elongated metal core and the protective film is located below the elongated metal core.

14. The tape measure of claim 10 wherein the peel strength is measured via a test defined by astm d 3330.

15. A tape measure comprising:

a housing;

a spool rotatably mounted within the housing;

an elongated blade coiled around the reel, the elongated blade having an inner end coupled to the reel and an outer end;

a hook assembly coupled to an outer end of the elongated blade; and

a retraction system coupled to the reel, wherein the retraction system drives the elongated blade to rewind onto the reel;

wherein, this microscler chi strip includes:

an elongated metal core having an upper surface and a lower surface, wherein the upper surface includes a concave curve and the lower surface includes a convex curve;

an upper nylon coating covering at least a portion of the upper surface of the elongated metal core;

a lower nylon coating covering at least a portion of a lower surface of the elongated metal core;

an ink layer forming a series of measurement indicia and located between the upper surface of the elongated metal core and the upper nylon layer;

a pressure sensitive adhesive layer coupled to at least one of an outer surface of the upper nylon coating and an outer surface of the lower nylon coating; and

a protective film coupled to the pressure sensitive adhesive layer adjacent the outer end of the elongated blade.

16. The tape measure of claim 15 wherein the protective film has a length that is less than 20% of the total length of the elongated blade.

17. The tape measure of claim 16 wherein the pressure sensitive adhesive layer is coupled to an outer surface of the lower nylon coating.

18. The tape measure of claim 15 wherein the upper nylon coating and the lower nylon coating each comprise nylon paint having a thickness between 0.01mm and 0.03 mm.

19. The tape measure of claim 15 wherein the elongate blade is less than 50 feet in length.

20. The tape measure of claim 15 wherein the peel strength between the protective film and at least one of the outer surface of the upper nylon coating and the outer surface of the lower nylon coating is greater than 9 pounds.

Background

The present invention relates generally to the field of tools. The present invention relates particularly to a tape measure, measuring tape, extension rule or the like which includes a relatively short reinforced polymer film coupled to the end of the blade adjacent the outer hook end of the blade.

Tape measures are measuring tools used in a variety of measuring applications, including use in the building and construction industry. Some tape measures include a graduated, marked blade that is wound on a reel, and also include a retraction system for automatically retracting the blade onto the reel. In some typical tape measure designs, the retraction system is driven by a coiled or helical spring that is tensioned as the tape measure is extended to store energy, and releases the energy to rotate the reel to wind the blade back onto the reel.

Disclosure of Invention

One embodiment of the present invention is directed to a tape measure that includes a reinforcing blade. The blade includes a metal core, a first coating on an upper surface of the metal core, and a second coating on a lower surface of the metal core. The hook assembly is coupled to the first end of the blade. The tape measure includes a polymeric protective film adhered to an outer surface of at least one of the first and second coatings adjacent the hook assembly such that a portion of the hook assembly extends over the protective film in a lengthwise direction of the blade. The protective film has a longitudinal length of less than 10 inches, specifically 4 to 8 inches. In various embodiments, the adhesive layer bonds the protective film to an adjacent coating. In various embodiments, the protective film has a peel strength from an adjacent coating of greater than 9 pounds.

Another embodiment of the present invention is directed to a tape measure that includes a housing, a spool rotatably mounted within the housing, and an elongated blade coiled around the spool. The elongated blade has an inner end coupled to the reel and an outer end extending out of the housing. The tape measure includes a hook assembly coupled to an outer end of the elongated blade and a retraction system coupled to the spool. The retraction system drives the elongated blade to rewind onto the reel. The elongated blade includes an elongated metal core having an upper surface and a lower surface, and the upper surface includes a concave curve and the lower surface includes a convex curve. The elongated blade includes an upper polymer coating covering at least a portion of the upper surface of the elongated metal core and a lower polymer coating covering at least a portion of the lower surface of the elongated metal core. The elongated blade includes an ink layer forming a series of measurement indicia and is located between the upper surface of the elongated metal core and the upper polymer coating. The elongated blade includes a protective film coupled to an outer surface of the lower polymer coating adjacent the outer end of the elongated blade via an adhesive, and the protective film has a length that is less than 20% of the total length of the elongated blade.

Another embodiment of the present invention is directed to a tape measure that includes a housing and a spool rotatably mounted within the housing. The tape measure includes an elongated blade coiled about a spool, and the elongated blade has an inner end coupled to the spool, and an outer end. The tape measure includes a hook assembly coupled to an outer end of the elongated blade and a retraction system coupled to the spool. The retraction system drives the elongated blade to rewind onto the reel. The elongated blade includes an elongated metal core having an upper surface and a lower surface. The upper surface includes a concave curvature and the lower surface includes a convex curvature. The elongated blade includes a protective film coupled to the elongated metal core via an adhesive. The protective film has a length less than the total length of the elongated blade and a peel strength between the protective film and the adjacent surface of the elongated blade of greater than 9 pounds.

Another embodiment of the present invention is directed to a tape measure that includes a housing and a spool rotatably mounted within the housing. The tape measure includes an elongated blade coiled about a spool, and the elongated blade has an inner end coupled to the spool, and an outer end. The tape measure includes a hook assembly coupled to an outer end of the elongated blade and a retraction system coupled to the spool. The retraction system drives the elongated blade to rewind onto the reel. The elongated blade includes an elongated metal core having an upper surface and a lower surface. The upper surface includes a concave curvature and the lower surface includes a convex curvature. The elongated blade includes an upper nylon coating covering at least a portion of the upper surface of the elongated metal core and a lower nylon coating covering at least a portion of the lower surface of the elongated metal core. The elongated blade includes an ink layer forming a series of measurement indicia and is located between the upper surface of the elongated metal core and the upper nylon layer. The elongated blade includes a pressure sensitive adhesive layer coupled to at least one of the outer surface of the upper nylon coating and the outer surface of the lower nylon coating. The elongated blade includes a protective film coupled to the pressure sensitive adhesive layer adjacent the outer end of the elongated blade.

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

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

Drawings

FIG. 1 is a left side perspective view of a tape measure according to an exemplary embodiment.

FIG. 2 is a left side perspective view of the tape measure of FIG. 1 with a portion of the tape measure housing removed, according to an exemplary embodiment.

FIG. 3 is a cross-sectional view of the hook end of the blade of the tape measure of FIG. 1 showing the blade film on the bottom of the blade according to an exemplary embodiment.

Fig. 4 is a top view of the ruler film of fig. 3 according to an example embodiment.

FIG. 5 is a perspective view of the tape film of FIG. 4 positioned on a roll of roll adhesive protective film according to an exemplary embodiment.

FIG. 6 is a cross-sectional view showing the tape film of FIG. 5 positioned on a release liner roll, according to an exemplary embodiment.

FIG. 7 is a cross-sectional view of the hook end of the blade of the tape measure of FIG. 1 showing the blade film on top of the blade according to an exemplary embodiment.

Fig. 8 and 9 illustrate aspects of a test procedure for measuring peel strength of a variety of different tape measures having the blade film prototype discussed herein and the film/coating of a commercial tape measure for comparison.

FIG. 10 shows the tensile strength and elongation at break of the blade film material according to an exemplary embodiment.

FIG. 11 shows a cross-sectional image of a commercially available prior art 1 blade.

FIG. 12 shows a cross-sectional image of a commercially available prior art 2 blade.

Detailed Description

Referring generally to the drawings, there are shown a number of different embodiments of tape measures. Various embodiments of tape measures discussed herein include an outer polymeric film layer coupled to a relatively short length of tape measure blade adjacent the hook end of the tape measure blade. The applicant has found that by reinforcing a relatively short length of blade adjacent to the hook, the blade will be more resistant to wear, damage, cracking etc. than a blade without such reinforcement, whilst reducing the overall blade diameter by confining the reinforcing film to only a short portion of the blade. Further, in some embodiments, applicants have found that a relatively high stiffness protective film further protects the blade from spinning during blade retraction.

In addition, in various embodiments, the applicant has developed a tape measure blade having an adhered, short hook end protective film with very high peel strength or adhesion to the blade of an adjacent layer. From applicants' testing, applicants determined that film applied to a shorter length of blade may delaminate during the extension/retraction cycle. Thus, as discussed in the various embodiments herein, applicants' design includes a very high level of peel strength that is believed to be not present in commercially available tape measures.

In addition, the applicant has determined that the short hook end protective film discussed herein helps to achieve a fast retraction time (from 8', 0.6-1 seconds) because of the increased stiffness of the blade by the film helping to resist blade revolutions when going up at a faster speed. In addition, applicants have determined that the short hook end protective film discussed herein increases the fatigue life of the blade even when a curl does occur. In addition, the applicant has determined that the short hook end protective film discussed herein holds the blade together for a longer period of time even if the tape measure breaks the film, thus preventing the blade from hanging up on parts of the housing during retraction.

As explained below, in particular embodiments, the short hook end protective film discussed herein is located on the bottom surface of the blade. In such embodiments, the applicant has determined that such placement has better performance in cold weather during tape measure revolutions.

Referring to fig. 1 and 2, a tape measure, such as tape measure 10, is shown according to an exemplary embodiment. The tape measure 10 includes a blade (shown as a coilable blade 14) and a housing 18. Generally, the blade 14 is an elongated strip of material that includes a plurality of scale measuring markings, and in a particular embodiment, the blade 14 is an elongated strip of metallic material (e.g., steel material) that includes an outermost end coupled with a hook assembly (shown as hook assembly 26). In one embodiment, the hook assembly 26 includes one or more magnets to facilitate coupling the hook assembly 26 with a workpiece during a measurement. As will be discussed in more detail below, the blade 14 may include a number of different coatings and layers (e.g., polymer coatings, films, etc.) to help protect the blade 14 and/or the scale markings of the blade from wear, breakage, revolutions, etc., particularly during blade retraction. In one embodiment, the first layer surrounding the steel is a paint with a measuring scale printed thereon, followed by a polymer or lacquer coating with a PET film applied thereon.

As shown in FIG. 1, the variable length extension 22 of the blade 14 can be retracted and extended from the housing 18. The hook assembly 26 is fixedly coupled to the outer end portion 30 of the blade 14. In various embodiments, the blade 18 can extend from the housing to a maximum length of between 10 feet and 50 feet.

As shown in FIG. 2, the inner end of the blade 14 is coupled to a reel 34, and the non-extended portion of the blade 14 is wound on the reel 34, which is surrounded by the housing 18. The reel 34 is rotatably disposed about the axis 38 of the tape measure 10, and a retraction system or mechanism 42 is coupled to the reel 34 and configured to drive the reel 34 about the axis of rotation 38, which in turn provides powered retraction of the blade 14. Typically, the retraction mechanism 42 drives the elongated blade to be rewound onto the tape reel 34. The retraction mechanism 42 may include one or more elongated coil springs that provide retraction energy to the retraction mechanism 42. In other embodiments, the retraction mechanism 42 includes other mechanisms such as one or more electric motors. A lock 46 is provided to selectively engage the blade 14 and is used to limit the retraction mechanism 42 so that the extended section 22 of the blade 14 is maintained at the desired length.

Referring to fig. 1, the housing 18 includes a first side wall 50, a second side wall 54, and a peripheral wall 58 connecting the first side wall 50 with the second side wall 54. As shown in fig. 2, the first side wall 50, the second side wall 54, and the peripheral wall 58 define an interior cavity 62 in which the spool 34 and the retraction mechanism 42 are received. Referring to fig. 1, the first and second sidewalls 50, 54 have a generally circular profile 66. In other embodiments, the sidewalls may be rectangular, polygonal, or any other desired shape. The portions of housing 18 may be co-molded or separately formed from a resilient material such as natural or synthetic rubber. In the illustrated construction, the housing 18 is formed with a housing bumper 70, and legs 74 extending from a lower portion 78 of the peripheral wall 58.

A slot 82 is defined along a forward portion 86 of the peripheral wall 58. The slot 82 provides an opening in the tape measure housing that allows the tape lock 46 to extend into the housing 18. Additionally, the length of the slot 82 is sufficient to enable the movement of the ruler lock 46 relative to the housing 18 between the locked and unlocked positions.

Below the slot 82, a tape opening (shown as tape mouth 90) in the housing is provided in the peripheral wall 58. The blade mouth 90 has an arcuate shape 94 corresponding to the arcuate cross-sectional profile of the blade 14. The blade 90 allows the blade 14 to be retracted into and extended from the cavity 62 defined within the housing 18.

As shown in fig. 1 and 2, the tape measure 10 includes a finger guard assembly 98. Finger guard assembly 98 includes a guard 102 and a guard support member 106. As shown in fig. 1, the portion of the guard 102 outside of the housing 18 is substantially U-shaped and extends downwardly from the housing 18. As shown in FIG. 2, when the blade 14 is in the retracted position, the rear surface of the hook assembly 26 abuts the guard 102.

Referring to fig. 3 and 4, the hooked end 110 of the blade 14 is shown according to an exemplary embodiment. The blade 14 includes an elongated metal core or inner layer 112 formed from a thin elongated strip of metal material. In a particular embodiment, the inner layer 112 is formed from a strip of steel material. In a particular embodiment, the thickness T1 of the inner layer 112 is between 0.09mm and 0.2mm, specifically between.1 mm and.18 mm (thickness varies by up to 25%), more specifically between.11 mm and.13 mm. As will be appreciated, the inner layer 112 may be formed in a concavo-convex configuration, thus providing the curved shape of the blade 14 shown in FIG. 1. In this arrangement, the upper surface of the blade 14 and the inner layer 112 include a concave curve, and the lower surface of the blade 14 and the inner layer 112 include a convex curve. Inner layer 112 may be an alloy spring steel, an alloy high strength steel, or the like. In one embodiment, the hardness of the steel is between 50-54RHC (Rockwell hardness C). In another embodiment, the hardness of the steel is between 45-60 RHC.

The blade 14 includes an upper coating 114 coupled (e.g., attached, bonded, glued, etc.) to the concave upper surface of the inner metal layer 112 and a lower coating 116 coupled (e.g., attached, bonded, glued, etc.) to the convex lower surface of the inner metal layer 112. Generally, the coatings 114 and 116 are formed from a polymeric material, and in a particular embodiment, a nylon material. As shown, the coating 114 has an upper surface 118 that defines the uppermost surface of the blade 14, and the coating 116 has a lower surface 120 that defines the lowermost surface of most of the blade 14. Ink layers are located between the coating 114 and the coating 116 forming a measuring mark or indicia, and in particular, on the upper and lower surfaces of the inner metal layer 112 between the coating 114 and the coating 116, respectively. In particular embodiments, the coatings discussed herein are formed from a nylon 12 material and/or a nylon 6/6 material. In various embodiments, the coatings 114 and 116 may be applied as a lacquer, a laminate, a nylon extrusion, an adhesive-attached film, or a powder/spray on coating.

In one embodiment, the coatings 114 and 116 may be applied over the entire length of the inner layer 112. In one embodiment, the coatings 114 and 116 are applied over a length of at least 6 feet of the inner layer 112, specifically over a length of at least 8 feet of the inner layer 112, more specifically over a length of at least 10 feet of the inner layer 112. In particular embodiments, these coating lengths are continuous lengths of coating material.

In a particular embodiment, coatings 114 and 116 are formed of nylon paint and have relatively smooth outer surfaces 118 and 120, respectively. In at least some embodiments, it is believed that the nylon lacquer has a higher surface energy than the film or extruded layer, which results in better bonding with the adhered polymer film. The lacquer was smoother compared to the nylon extrudate. Different polymers have different surface energies, which can alter the bond strength and when combined with surface roughness will provide different low temperature properties. This can be achieved by matching the glue to the layer to which it is applied, in order to obtain improved performance and higher bonding/peeling forces. The thickness and type of glue is also related to the peel force. In the case of pressure-sensitive adhesives, the pressure with which the film is applied is also a factor related to peel strength.

As shown in fig. 3, a ruler-strip film 122 is bonded or adhered to the outer surface 120 of the lower coating 116. In such an embodiment and without being bound by theory, applicants believe that placing the film 122 on the lower surface provides reinforcement while reducing the chance of delamination due to the mechanics of the blade during the turn. When the film is applied to the bottom side, the film is in tension rather than compression during tape revolution. This contributes to increased stiffness and low temperature performance of the film. In another embodiment, the film 122 may be applied directly to the printed layer of paint without a coating in between.

Typically, the blade film 122 is a stiffening layer formed of a polymeric material, particularly a transparent polymeric material, to allow viewing of indicia markings located beneath the film 122 in the blade configuration. In various embodiments, the blade membrane 122 is formed of a polymer material having high stiffness, which applicants have determined reduces the likelihood of the blade circling during retraction. In various embodiments, the stiffness of the diaphragm 122 is selected to be higher than other commonly used blade materials to reduce curl. In a particular embodiment, the blade film 122 is formed from a polyethylene terephthalate (PET) material, such as a relatively high stiffness PET material. In particular embodiments, the tensile modulus, flexural modulus, and hardness will be combined with the thickness of the film to provide rigidity and resist the wrap of the tape during retraction when applied to the tape measure. Fig. 10 shows modulus and elongation at break data for materials that may be used for the ruler film 122. In another embodiment, the ruler film 122 is formed of a Thermoplastic Polyurethane (TPU) material.

The ruler-strip film 122 is adjacent to the hook end 110 such that it overlaps the hook tab 124. Unlike the coatings 114 and 116, the blade film 122 has a length L1 such that the blade film 122 extends a relatively short portion of the length of the blade 14 from the hook end 110. In various embodiments, L1 is less than 20% of the total length of the blade 14, specifically less than 10% of the total length of the blade 14, and more specifically less than 5% of the total length of the blade 14. In various embodiments, L1 is 2 inches to 12 inches, specifically 4 inches to 8 inches, and more specifically 5 inches to 7 inches. In a specific embodiment, L1 is 6 inches plus or minus 5%. Applicants have determined that a relatively short reinforcing layer, such as the blade film 122, provides improved blade strength, wear resistance, fracture resistance, and roll resistance without unduly increasing the overall thickness of the blade on the spool.

In various embodiments, applicants have determined that a particular thickness of the blade film 122 and coatings 114 and 116 provides increased blade protection without unduly increasing the tape measure spool diameter. As shown in fig. 3, coating 114 has a thickness T2, coating 116 has a thickness T3, and rule film 122 has a thickness T4. In various embodiments, T4 is between 0.03mm and 0.3mm, specifically between 0.1mm and 0.2mm, more specifically between 0.14mm and 0.16 mm. In a specific embodiment, T4 is 0.15mm plus or minus 0.005 mm. In another specific embodiment, T4 is between 0.14mm and 0.25 mm.

In various embodiments, coating 114 and/or coating 116 are formed from a polymeric material, such as a polymeric lacquer, and thicknesses T2 and/or T3 are between 0.01mm and 0.03mm, and specifically about 0.02 mm. In a particular embodiment, the thickness T2 and/or T3 of coating 114 and/or coating 116 formed of nylon paint is between 0.01mm and 0.03mm, and specifically is about 0.02 mm. In a specific embodiment, the steel is 0.11 thick and the nylon paint on each side is 0.02-0.03 thick.

In a particular embodiment, the blade film 122 is adhered to the adjacent coating via a layer of adhesive material 126. In various embodiments, the adhesive layer 126 is formed from a polymeric adhesive, such as a pressure sensitive adhesive. In a particular embodiment, the adhesive layer 126 is a pressure sensitive acrylic material.

Applicants have determined that by balancing the thickness of the blade film 122 with the thickness of the adhesive layer 126, a very high level of adhesion of the blade film 122 to the blade 14 can be achieved. In various embodiments, the adhesive layer 126 has a thickness of 0.01mm and 0.05mm, specifically 0.01mm to 0.035mm, and more specifically 0.02mm plus or minus 5%. In various embodiments, the ratio of adhesive layer thickness to T4 is selected to provide improved adhesion/peel strength. In various embodiments, the ratio of adhesive layer thickness to T4 is between 0.05 and 0.25, specifically between 0.1 and 0.15, and more specifically between 0.13 and 0.14.

In particular embodiments, applicants have determined that the level of adhesive strength (as determined by the peel strength test defined in astm d3330, and described below) is significantly higher than the commercial tape measure that applicants tested. The applicant has determined that this measured characteristic of the blade protective layer is related to the likelihood of delamination of the protective layer from the blade, which is one of the primary failure modes of the blade protective layer. In various embodiments, the peel strength between the blade film 122 and the adjacent coating is greater than 9 pounds, specifically greater than 10 pounds, and more specifically greater than 11 pounds. In the particular embodiment where coating 116 is a smooth layer of nylon paint, applicants' design accomplishesGreater than 18 pounds peel strength. (For example, seeExamples in table 1 below).

Referring to fig. 4, dimensional details of the ruler film 122 according to an exemplary embodiment are shown. In the particular embodiment shown, the blade film 122 is sized to attach to the inner metal layer 112 having a width of 32 mm.

Referring to fig. 3 and 4, with the ruler film 122 positioned adjacent the hook assembly 26, the hook rivet 128 passes through the ruler film 122. To accommodate the hook rivets 128, the blade film 122 includes at least one opening for each hook rivet 128. In the particular embodiment shown, the hook assembly 26 includes two rivets 128, and thus, the rule film 122 includes a first rivet opening 130 and a second rivet opening 132. To position the rivet openings 130 and 132 adjacent the hook assembly 26, the rivet openings 130 and 132 are located in the front half, and particularly the front quarter, of the length of the rule film 122. In another embodiment, if the PET film is applied before punching the rivets, the film 122 and other layers of the blade may be punched simultaneously.

Referring to fig. 5, a plurality of ruler films 122 may be provided on a roll 140 of release liner 142. During the manufacture of the blade 14, one blade film 122 is removed from the coil 140 and adhered to each blade via adhesive. Fig. 6 shows a cross-sectional view of a particular embodiment of a ruler-strip film 122 on a release liner 142. In various embodiments, the thickness of the tape film 122, adhesive layer 126, and release liner 142 are shown in fig. 6. In one embodiment, the thickness dimension shown in FIG. 5 is in inches, while in another embodiment, the thickness dimension shown in FIG. 5 is in millimeters.

Fig. 7 illustrates a hook end 150 according to an exemplary embodiment. Hook end 150 is substantially identical to hook end 110 except for the differences discussed herein. In the arrangement of the hook end 150, the blade film 122 is coupled to the outer surface 118 of the upper coating 114. In this arrangement, the blade film 122 is located on the upper surface of the blade 14 and is positioned so that the outer surface of the blade film 122 is in contact with the inner surface of the hook tab 152.

Rule film and adhesive material

In various embodiments, applicants have identified a variety of specific materials for the ruler film 122 and adhesive layer 126 that are believed to improve one or more of the performance characteristics of the ruler film 122 discussed herein.

In a particular embodiment, the blade film 122 is formed of a PET material. In general, applicants have determined that the stiffer the material of the blade film 122, the greater the resistance it provides to resist the orbital rotation of the blade 14 during retraction. Applicants have determined that PET is a particularly stiff film compared to other potential polymers, while still being transparent. In a specific embodiment, the blade film 122 is formed from PET film 75% CAS. NO.931-36-2.

In a particular embodiment, the blade film 122 is a PET film with an acrylic glue forming layer 126. In this example, the film with glue has 75% PET, 12.5% polyurethane, 10% epoxy, 2.5% curing agent.

In a particular embodiment, the blade film 122 is formed from a polymeric material, such as PET, which has the following physical properties. Transparent in color and density of 1.395-1.405g/m 3; melting point, GB/T13541, 259.5 °; tensile strength, MPA, GB/T13541, 170/210; elongation at break,%, GB/T13541, 130/110; thermal shrinkage,%, GB/T13541, 1.5/0.5; the continuous use temperature is-20-120 ℃.

In various embodiments, the material forming the adhesive layer 126 is a pressure sensitive polymer adhesive, and specifically a pressure sensitive acrylic material. In a particular embodiment, the material forming the adhesive layer 126 is an acrylic glue comprising: 12.5 percent of polyurethane (CAS. NO.51852-81-4), 10 percent of modified epoxy resin (CAS. NO. 25068-38-6); curing agent 2.5% CAS. NO. 931-36-2.

In particular embodiments, the material forming the adhesive layer 126 includes one or more of the following properties: initial adhesion, GF/inch, FINAT 9, > 1000; 180 ° peel strength, GF/inch, ASTM D3330, > 800; permanent adhesion, H, FINAT 8, > 24; thickness, ASTM D3652, (0.03. + -. 0.002) MM; the continuous use temperature is-10-80 ℃.

Peel Strength and test procedure

As noted above, applicants have determined that the peel strength of the tape film 122 formed as discussed herein has a much higher peel strength than commercially available prior art tape measures. Without wishing to be bound by theory, applicants believe that the blade films discussed herein have increased peel strength due to the nature of the interface between the adjacent coating and adhesive. In addition, the thickness of the ruler-strip film also appears to be related to the peel strength.

Table 1 below shows the peel strength of two arrangements of the blade 14 with blade film 122 discussed herein compared to two commercially available tape measures. The procedure for testing peel strength is set forth in astm d3330, and images of an example test procedure are shown in fig. 8 and 9. As shown in fig. 8, the Instron clamp 200 grips the film on the blade 202, and the Instron clamp 204 secures the blade. To set, the tape was positioned so that the folded region of the film was within the Instron clamp 200. One inch long test sample tape 202 was clamped in an Instron grip 204 with the base six inches from the edge. Figure 9 shows the clamping of the sample. The clamp is lowered so that it can grip the folded section and the extension of the machine is set to zero. In the test, the extension rate was set at 8 mm/s. The selection is to start running the test and to zero when the clamps have reached the maximum extension. The output data from the test run are the machine extension distance and force, and the force measurements in different zones are averaged, such as in the 75.0mm to 225.00mm zone.

TABLE 1

Both commercially available prior art 1 and commercially available prior art 2 have a blade with a first film over the entire blade, and a second film at the first six inches above the first film. Commercial prior art 1 has a thicker film than commercial prior art 2. For reference, enlarged photographs with markings and annotations are shown in fig. 11 and 12, respectively, for commercial prior art 1 and commercial prior art 2.

In addition to the peel strength tests discussed above, applicants also tested the number of retractions of various blade that resulted in delamination of various blade protective layers. During this test, the applicant obtained 10 samples of a 25 foot version of the commercially available prior art 2 tape measure and conducted a retraction test. During this test, the tape is pulled 8' out of the housing and then the tape is retracted into the housing. This is done on a testing machine that keeps each tape measure in the same position for each test and minimizes human variation. Commercially available prior art 2 tape retraction 8' takes on average 0.75 seconds (ranging from 0.66 seconds to 1.0 seconds) and an average of 162.4 cycles (ranging from 56-314 cycles) before the tape tears. In addition, the applicant obtained 10 new samples of a 25 foot version of the commercial prior art 2 tape measure, removed the protective film located around the first 6 inches, and performed the same retraction test. Commercial prior art 2 without film retracted an average of 0.739 seconds (ranging from 0.65 seconds to 0.99 seconds) and averaged only 58.9 cycles (ranging from 14-111) before the tape torn. Thus, the life of the film over the first six inches increased by an average of 103.5 cycles for the commercial prior art 2 tape measure tested.

Applicants also performed the same retraction test on a 25 foot version of a commercially available prior art 1 tape measure (e.g., 10 samples with film and 10 samples without film). With the film, the commercially available prior art 1 tape measure retracted an average of 0.698 seconds (ranging from 0.63 to 0.79 seconds) and an average of 179.7 cycles (ranging from 22 to 683) before the tape torn. Without the film, the commercial prior art 1 tape measure retracted an average of 0.685 seconds (ranging from 0.60 seconds to 0.76 seconds) and an average of 75.8 cycles (ranging from 21-194 cycles) before the tape broke. Thus, the life of the film over the first six inches increased by an average of 103.9 cycles for the commercial prior art 1 tape measure.

Applicant also performed the same retraction test on the 25 foot version of prototype 2. Applicant used a 25-foot version of prototype 2. The applicant tested three samples of prototype 2 without the PET film on the first six inches, which had an average retraction time of 0.83 seconds (ranging from 0.83 seconds to 0.84 seconds) and an average of 112 cycles (ranging from 65-173 cycles) before tape tearing. Applicants then tested four samples of prototype 2, which did have a PET film on the first six inches of the blade, and which had an average retraction time of 0.86 seconds (ranging from 0.83 seconds to 0.87 seconds), but an average of 2,023.8 cycles (ranging from 1430-. Thus, the reinforcement of the PET film on the blade of prototype 2 increased the life of the blade in this test by more than 1,911 cycles (i.e., 18 times longer life).

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

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

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

Various embodiments of the invention are directed to any combination of features and any such combination of features may be claimed in this or a future application. Any of the features, elements or components of any of the exemplary embodiments discussed above may be used alone or in combination with any of the features, elements or components of any of the other embodiments discussed above.