Measuring tape with improved case durability

A measuring tape device may include a housing having an aperture, a reel assembly enclosed within the housing, and a blade having a first end configured to extend from the housing through the aperture and a second end configured to be wound on the reel assembly. The housing may include a first case half and a second case half. The reel assembly may be configured to alternately allow the blade to be withdrawn from the reel assembly through the aperture or received in the aperture onto the reel assembly. The first case half and the second case half may be joined together via threaded fasteners inserted into respective portions of screw bosses formed in corresponding portions of the first and second case halves. Mating features may be provided on the first and second case halves to facilitate joining the first and second case halves. At least some of the mating features may be longer than others of the mating features, or a diameter of the screw bosses is about 1.5 time to about 2.5 times larger than a diameter of the threaded fasteners.

TECHNICAL FIELD

Example embodiments generally relate to measuring tape devices, and particularly relate to a measuring tape that is structured to have improved durability.

BACKGROUND

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

The reel assembly can often also be locked at a given location so that, for example, the measuring tape can be locked with a given amount of the metallic tape ribbon extending out of the housing of the measuring tape. The locking mechanisms that support this functionality are typically embodied as a sliding lock button that is disposed on a top and/or front portion of the measuring tape housing. The housing is often formed from case halves that are joined together to enclose the tape and at least a drum and spring that are part of the reel assembly. A common failure mode for measuring tapes has been for the drum and spring, or other parts of the reel assembly to become inoperable after an impact event (e.g., dropping the measuring tape from a height). In some cases, the two case halves may become temporarily separated due to the impact, and the tape itself may become bound in the gap formed between the two case halves. In other cases, the drum and spring may become disengaged by the impact thereby preventing functional retraction of the tape blade after it is extended from the housing.

Typical efforts to improve durability have centered around increasing substrate and over-mold wall thickness. However, as can be appreciated from the failure modes described above, these efforts do not specifically target, and can be ineffective to address, some of the main failure modes that are experienced. In this regard, thickening of portions of the case do not address the fact that some of the main failure modes occur due to temporary separation of the parts of the case, and not due to failure of the case walls themselves. Accordingly, it may be desirable to design a measuring tape device with a more robust capability to avoid case half separation.

BRIEF SUMMARY OF SOME EXAMPLES

Some example embodiments may enable the provision of a measuring tape that has case halves that are designed to be joined together in a more robust way. In this regard, for example, some embodiments may provide improved fastening structures and/or mating features between the case halves in order to reduce vulnerability to impact damage.

In an example embodiment, a measuring tape device is provided. The measuring tape device may include a housing having an aperture, a reel assembly enclosed within the housing, and a blade having a first end configured to extend from the housing through the aperture and a second end configured to be wound on the reel assembly. The housing may include a first case half and a second case half. The reel assembly may be configured to alternately allow the blade to be withdrawn from the reel assembly through the aperture or received in the aperture onto the reel assembly. The first case half and the second case half may be joined together via threaded fasteners inserted into respective portions of screw bosses formed in corresponding portions of the first and second case halves. Mating features may be provided on the first and second case halves to facilitate joining the first and second case halves. At least some of the mating features may be longer than others of the mating features, or a diameter of the screw bosses is about 1.5 time to about 2.5 times larger than a diameter of the threaded fasteners. In another example embodiment, a measuring tape device is provided. The measuring tape device may include a housing having an aperture, a reel assembly enclosed within the housing, and a blade having a first end configured to extend from the housing through the aperture and a second end configured to be wound on the reel assembly. The housing may include a first case half and a second case half. The reel assembly may be configured to alternately allow the blade to be withdrawn from the reel assembly through the aperture or received in the aperture onto the reel assembly. The first case half and the second case half may be joined together via mating features provided on the first and second case halves to facilitate joining the first and second case halves. At least some of the mating features are about 45% to about 55% longer than others of the mating features.

In yet another example embodiment, a measuring tape device is provided. The measuring tape device may include a housing having an aperture, a reel assembly enclosed within the housing, and a blade having a first end configured to extend from the housing through the aperture and a second end configured to be wound on the reel assembly. The housing may include a first case half and a second case half. The reel assembly may be configured to alternately allow the blade to be withdrawn from the reel assembly through the aperture or received in the aperture onto the reel assembly. The first case half and the second case half may be joined together via threaded fasteners inserted into respective portions of screw bosses formed in corresponding portions of the first and second case halves. A diameter of the screw bosses may be about 1.5 time to about 2.5 times larger than a diameter of the threaded fasteners. The diameter of the screw bosses may be about 7.8% to about 8.8% of a defining diameter of the first and second case halves, and the screw bosses may occupy about 2% to about 3% of a cross sectional area enclosed by the first and second case halves.

DETAILED DESCRIPTION

As indicated above, some example embodiments may relate to the provision of a measuring tape device that may have an improved design for resistance to impact damage. This may be accomplished by providing mating features and/or fastening structures that resist separation of the case halves in response to impact and, in some cases, may also guide the case halves back together to ensure proper alignment of the case halves is maintained or restored responsive to such impact.FIG. 1illustrates a perspective view of a measuring tape device,FIG. 2illustrates a block diagram of such device, in accordance with an example embodiment, andFIG. 3illustrates a front view of the measuring tape device to illustrate the case halves thereof.

Referring now toFIGS. 1-3, a measuring tape device100of an example embodiment may include a housing110comprising a first case half112and a second case half114. The first and second case halves112and114may house a reel assembly120and a self-retraction assembly130therein. A blade140(or tape) portion of the device100may be wound onto the reel assembly120. The blade140may be paid out through an aperture150formed in the housing110. A locking assembly160may be provided to enable the reel assembly120to be locked to prevent the self-retraction assembly130from retracting the blade140when the locking assembly160is engaged.

The blade140has an end hook170disposed at one end thereof, and is affixed to the reel assembly120at the other end of the blade140. The end hook170may be affixed (temporarily) to an anchor point on a medium that is to be measured. Once the end hook170is affixed to the anchor point, the blade140may be paid out of the aperture150and unwound from the reel assembly120. When a desired length of the blade140has been paid out, the user can make any necessary markings, readings, etc., associated with measuring scale markings that may be printed on the blade140. The measuring scale markings generally measure length from the end hook170in one or more units, with divisions and subdivisions of such units clearly marked on the blade140.

By fixing the end hook170to the anchor point, the self-retraction assembly130(which may be spring loaded in some cases) may be prevented from retracting the paid out portions of the blade140into the housing110(via the aperture150). Similarly, when the locking assembly160is engaged, a force (e.g., a pinching force) may be placed on the blade140to prevent retraction or motion of the reel assembly120may otherwise be inhibited to prevent the self-retraction assembly130from retracting the paid out portions of the blade140. However, when the end hook170is not anchored and the locking assembly160is not engaged, the self-retraction assembly130may cause the reel assembly120to wind the blade140back onto the reel assembly120.

As mentioned above, impacts may cause separation of the first case half112from the second case half114. Although the separation may be temporary and/or small, such separation can still cause lasting consequences for operation of the measuring tape device100. For example, if any portion of the blade140gets bound in between the first and second case halves112and114, or if the spring and drum of the self-retraction assembly130become misaligned, it may not be possible to continue to rewind the blade140onto the reel assembly120once the blade140is withdrawn from the housing110. Example embodiments increase the size of certain mating features as a function of the overall dimensions of the measuring tape device100in order to strike an optimal balance between the size and weight of the measuring tape device100and its robustness.

In this regard, the size of the reel assembly120(e.g., the diameter of the reel) may be a significant determiner of the minimum dimensions of the measuring tape device100. The housing110, which is desirably kept to a light and compact construction, must have at least sufficient height (H), length (L) and width (W) to enclose the reel assembly120when the full length of the blade140is stored thereon. The diameter of the reel assembly120may therefore be referred to as a “defining diameter” for the measuring tape device100. The defining diameter controls the height (H) and length (L) dimensions for the housing110(and therefore also for the first and second case halves112and114). The width of the reel assembly120also determines a minimum width for the measuring tape device100, and the width (W) of the housing110will be desirably kept relatively close to the minimum width.

Some example embodiments may define optimal characteristics for certain fastening structures or mating features that join the first and second case halves112and114together. In this regard, for example, the optimal characteristics may be defined as a function of the defining diameter and/or the width (W) of the housing110. Fastening structures such as screw bosses may be increased in diameter relative to typical screw bosses. For example, the screw bosses may be increased in diameter to define an optimal screw boss diameter as a function of the defining diameter. Doing so may make the screw bosses much less likely to fail due to cracking, stripping out, or other failure modes, and may also increase the ability of the screw bosses and the fasteners provided therein to retain the first and second case halves112and114in contact in response to impact. Meanwhile, the mating features may be increased in length to define an optimal mating feature length as a function of the width (W) of the housing110. Doing so may increase the ability of the measuring tape device100to avoid failure on impact since the longer mating features may ensure that contact and alignment is maintained between the first and second case halves112and114during any minor separation thereof, and the alignment will ensure that the first and second case halves112and114guide themselves back together in response to impact.

FIGS. 4-8illustrate various different views of the first and second case halves112and114in isolation in order to facilitate a discussion of the optimization of the housing110construction in accordance with an example embodiment. In this regard,FIG. 4illustrates a perspective view of an inner portion of the first case half112andFIG. 5illustrates a side view of the inner portion of the first case half112.FIG. 6illustrates a perspective view of an inner portion of the second case half114andFIG. 7illustrates a side view of the inner portion of the second case half114.FIG. 8illustrates a front view of the first and second case halves112and114separated from each other to show the length of the mating features.

Referring now toFIGS. 4-8, the first and second case halves112and114may each include sidewalls and an end wall that form a cup-like structure. An end wall200of the first case half112and an end wall202of the second case half114may each extend substantially parallel to each other when the first and second case halves112and114are joined together to form the housing110. Sidewalls210of the first case half112may extend substantially perpendicularly away from the end wall200of the first case half112. However, there may be a curved transition from the end wall200of the first case half112to the sidewalls210of the first case half112. Similarly, sidewalls212of the second case half114may extend substantially perpendicularly away from the end wall202of the second case half114. However, there may also be a curved transition from the end wall202of the second case half114to the sidewalls212of the second case half114. A receiving opening220may be defined between the sidewalls210and212inside which the reel assembly120may be housed. As shown inFIGS. 5 and 7, the defining diameter (D) may be defined at least in part by the radial length (i.e., diameter) of the receiving opening220.

The first and second case halves112and114meet each other at a first mating surface230and a second mating surface232, respectively. The first and second mating surfaces230and232each lie in a plane and, when joined together, meet at a common plane. The first mating surface230may be disposed at a distal end of the sidewalls210of the first case half112and may define a continuous flat surface that lies perpendicular to the axis of rotation of the reel assembly120at or near an outer periphery of the side of the first case half112that faces the second case half114. The second mating surface232may be disposed at a distal end of the sidewalls212of the second case half114and may define a continuous flat surface that lies perpendicular to the axis of rotation of the reel assembly120at or near an outer periphery of the side of the second case half114that faces the first case half112. The first and second mating surfaces230and232may meet each other upon assembly of the housing100at the common plane to define a nearly continuous enclosure around the reel assembly120and the self-retraction assembly130within the receiving opening220.

Screw bosses240may be incorporated into the first and second mating surfaces230and232to enable fasteners (e.g., screws) to be threaded therein to hold the first case half112and the second case half114together. In this regard, the first and second mating surfaces230and232may substantially mirror each other, and the screw bosses240may be positioned to also mirror each other so that any portion of one of the screw bosses240that lies in the first case half112will align with a corresponding portion of one of the screw bosses240that lies in the second case half114when the first and second mating surfaces230and232are mated together.

The screw bosses240may be mounting features that are formed as substantially hollow cylindrical structures configured to receive a screw in the internally hollow portion thereof. Although the outer shape of the screw bosses240need not necessarily be perfectly cylindrical, a general cylindrically shaped structure is formed (e.g., during molding) of the base material (e.g., resin, plastic, polymers, or other rigid materials such as, for example, acrylonitrile butadiene styrene (ABS)) used to form the first and second case halves112and114. The screw bosses240could be threaded. However, in an example embodiment, the screw bosses240may be initially be formed without any threads therein, and a thread forming fastener300(seeFIG. 9) may be used to form threads in the screw bosses240when the thread forming fastener300is inserted therein.

The screw bosses240may be formed to have a diameter (DB) that is substantially the same for each screw boss240and portion thereof. Moreover, the diameter (DB) of the screw bosses240may be optimized as a function of the defining diameter (D), as a function of the cross sectional area enclosed by the meeting of the first and second mating surfaces230and232and/or as a function of the diameter (DF) of the thread forming fastener300(seeFIG. 9). In this regard, for example, the diameter (DB) of the screw bosses240may be about double (e.g., from 1.5× to 2.5×) the diameter (DF) of the thread forming fastener300. In this example, if the diameter (DF) of the thread forming fastener300is 0.125 inches, the diameter (DB) of the screw bosses240may be about 0.25 inches.

Additionally or alternatively, the diameter (DB) of the screw bosses240may be structured to occupy about 2.4% (e.g., from 2% to 3%) of the cross sectional area enclosed by the meeting of the first and second mating surfaces230and232. Thus, for this example in which the diameter (DB) of the screw bosses240is about 0.25 inches, the cross sectional area enclosed by the meeting of the first and second mating surfaces230and232(e.g., the area enclosed, normal to the centerline of the case, as a line drawn around the perimeter of the case at the meeting of the first and second case halves112and114, substrate and over-mold included) may be about 8.14 square inches.

Additionally or alternatively, the diameter (DB) of the screw bosses240may be structured to have a ratio to the defining diameter (D) of about 8.3% (e.g., from about 7.8% to about 8.8%). It is generally advantageous to maximize each of the relationships discussed above while still maintaining good clearance for proper operation of the reel assembly120. Thus, for example, the relationships discussed above are selected to be as large as they can be while still keeping the housing110as small and light as it can be while still enabling the reel assembly120and the self-retraction assembly130to operate properly. The particular relationships identified above can be followed for any size of measuring tape device100in order to give optimal balance between minimizing weight and size, while maximizing strength and durability.

As perhaps best seen inFIG. 8, one or both of the first and second case halves112and114may include mating features that extend from and are received within corresponding portions of the first and second case halves112and114. The mating features may include protruding members that extend perpendicularly away from a respective one of the first and second mating surfaces230and232and corresponding receiving slots that are shaped to receive respective ones of the protruding members. Some of the protruding members (e.g., case alignment protruding members260) may be formed to correspond to edges of the sidewalls210or212and/or edges defining the receiving opening220. Others of the protruding members (e.g., boss alignment protruding members270) may be formed to facilitate alignment of the screw bosses240when the first and second case halves112and114are joined together. As used herein, the term “protruding members” can therefore be understood to refer to either or both of the case alignment protruding members260and the boss alignment protruding members270.

In this example, the first case half112includes the case alignment protruding members260and boss alignment protruding members270, and the second case half114includes corresponding receiving slots262and272, which may be shaped to receive respective ones of the protruding members. However, it should be appreciated that all or some of the protruding members could extend from the second case half114into respective instances of the receiving slots262and272positioned at the first case half112.

In this example, some of the protruding members may be longer than others. In this regard, all of the protruding members may generally have the same length (e.g., 0.110 inches) except for protruding members that are in a critical area. Based on experience regarding failure modes, and based on testing regarding the same, the bottom portion of the housing110(i.e., the portion of the housing110along which the blade140extends prior to exiting the aperture150) may be considered as the critical area since it is most prone to failure during impact events. Accordingly, at least some of the protruding members in the critical area may have a length that is about 50% (e.g., 45% to 55%) longer than other protruding members. In this example, case alignment protruding members260′, which are located in the critical area, are about 50% longer than other protruding members. Thus, the case alignment protruding members260′ in the critical area are about 0.165 inches long in this example. The case alignment protruding members260′ in the critical area may also or alternatively have a length that is selected to be about 8.8% of the width (W) of the housing110. Thus, for example, the case alignment protruding members260′ in the critical area may have a length of about 8.3% to about 9.3% of the width (W) of the housing110.

In an example embodiment, a measuring tape device is provided. The measuring tape device may include a housing having an aperture, a reel assembly enclosed within the housing, and a blade having a first end configured to extend from the housing through the aperture and a second end configured to be wound on the reel assembly. The housing may include a first case half and a second case half. The reel assembly may be configured to alternately allow the blade to be withdrawn from the reel assembly through the aperture or received in the aperture onto the reel assembly. The first case half and the second case half may be joined together via threaded fasteners inserted into respective portions of screw bosses formed in corresponding portions of the first and second case halves. Mating features may be provided on the first and second case halves to facilitate joining the first and second case halves. At least some of the mating features may be longer than others of the mating features, or a diameter of the screw bosses is about 1.5 time to about 2.5 times larger than a diameter of the threaded fasteners.

In some embodiments, the features of the device described above may be augmented or modified, or additional features may be added. These augmentations, modifications and additions may be optional and may be provided in any combination. Thus, although some example modifications, augmentations and additions are listed below, it should be appreciated that any of the modifications, augmentations and additions could be implemented individually or in combination with one or more, or even all of the other modifications, augmentations and additions that are listed. As such, for example, in some cases both the at least some of the mating features may be longer than the others of the mating features, and the diameter of the screw bosses may be about 1.5 time to about 2.5 times larger than the diameter of the threaded fasteners. In some cases, the at least some of the mating features may be about 45% to about 55% longer than the others of the mating features. Alternatively or additionally, the at least some of the mating features are about 8.3% to about 9.3% of a total width of the first and second case halves. In an example embodiment, the at least some of the mating features may include protruding members disposed at the first case half to extend into respective receiving slots disposed at the second case half. In some cases, the protruding members may be case alignment protruding members disposed at a bottom portion of the housing alongside which the blade extends prior to extending through the aperture. In an example embodiment, the mating features may include protruding members disposed only on the first case half to extend into respective receiving slots disposed only on the second case half. In some cases, the diameter of the screw bosses may be about 7.8% to about 8.8% of a defining diameter of the first and second case halves. In an example embodiment, the screw bosses occupy about 2% to about 3% of a cross sectional area enclosed by the first and second case halves. In some cases, the diameter of the screw bosses is about 7.8% to about 8.8% of a defining diameter of the first and second case halves, and the screw bosses occupy about 2% to about 3% of a cross sectional area enclosed by the first and second case halves.