Layered beam measurement apparatus

This application is a continuation of and claims the benefit of prior U.S. patent application Ser. No. 11/556,381, filed 3 Nov. 2006, which claims the benefit of U.S. provisional application No. 60/733,914, filed on 4 Nov. 2005, which are both incorporated in their entirety by this reference.

The present disclosure relates generally to measurement tools, and in particular to tape measures.

The ideal tape rule would be perfectly flat and yet would not suffer from bending or folding when in the cantilevered position. Yet the tape rule of all tape measures loses rigidity after being extended to some length. To increase the rigidity of tape rules, tape rules of the prior art opt for either a wider tape rule or a deeper curve in the profile of the tape rule. However, a deeper profile in the tape rule results in difficulty in marking measurements on the surface being measured as the edges of the tape rule tend to curve up and away from the surface being measured. This results in the user having to tilt the tape in order to accurately mark a desired measurement.

FIG. 1 is a cross-sectional diagram of a tape rule in accordance with the teachings of this disclosure;

FIG. 2 is a cross sectional view of a tape rule assembly in accordance with the teachings of this disclosure taken at Line 2 - 2 of FIG. 1 ;

FIG. 3 is a section view of a tape rule assembly in accordance with the teachings of this disclosure; and

FIG. 4 is a cross-sectional diagram of a tape rule in accordance with the teachings of this disclosure.

Embodiments of the present invention described in the following detailed description are directed at virtual agents. Those of ordinary skill in the art will realize that the detailed description is illustrative only and is not intended to restrict the scope of the claimed inventions in any way. Other embodiments of the present invention, beyond those embodiments described in the detailed description, will readily suggest themselves to those of ordinary skill in the art having the benefit of this disclosure. Reference will now be made in detail to implementations of the present invention as illustrated in the accompanying drawings. Where appropriate, the same reference indicators will be used throughout the drawings and the following detailed description to refer to the same or similar parts.

In the interest of clarity, not all of the routine features of the implementations described herein are shown and described. It will, of course, be appreciated that in the development of any such actual implementation, numerous implementation-specific decisions must be made in order to achieve the developer's specific goals, such as compliance with application- and business-related constraints, and that these specific goals will vary from one implementation to another and from one developer to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking of engineering for those of ordinary skill in the art having the benefit of this disclosure.

Referring now to FIG. 1 shows a cross section of the full tape assembly 30 . An end hook 14 is attached to a primary tape rule 10 . Affixed to the underside of the primary tape rule 10 is a secondary tape rule 12 . The secondary tape rule 12 is slidably affixed to the primary rule in at least two locations; the leading edge, closest to hook 14 and trailing ends closest to the housing 16 . FIG. 1 shows the primary tape rule entering a housing 16 and connecting with a reel 18 . The reel 18 is connected to a flat wound coil spring 20 that is reciprocally attached to the housing 16 so as to provide a retracting bias to the reel as is known in the art. The trailing end is preferable rigidly affixed using a weld, adhesive, rivet, hooking mechanism(s) or similar fixing method. The housing 16 may include a user-actuatable rule lock as is known in the art.

Referring now to FIG. 2 , a cross-sectional diagram of an assembly of the primary 10 and secondary 12 tape rules taken along section 2 of FIG. 1 . In one preferred embodiment, the secondary rule 12 may include a pair of edge portions 13 that may fold over the primary rule, providing for a relative sliding motion between the two rules. The leading end may be slidably affixed in such a way as to allow lengthwise relative motion of the primary 10 and secondary 12 tape rules.

FIG. 3 is an isometric view of the assembly illustrating the operation of the layer tape rule apparatus of this disclosure. The tape rule is extended in the usual manner for general tasks. In one embodiment, in shorter extension type tasks, only the primary tape rule 10 need extends beyond the housing for flexible utility. This also serves the purpose of minimizing the extended mass. As the primary rule 10 is extended for longer extension type tasks, the leading end of the secondary tape rule 12 may extend beyond the housing, increasing the combined section stiffness and stand out length, and reducing sag.

As the combined tape rule assembly extends, the leading end of the secondary tape 12 moves lengthwise relative to the primary tape 10 to adjust for relative length changes encountered while unrolling from the reel. When the secondary tape rule 12 trailing edge is in the housing 16 and the leading edge is extended from the housing, the leading edge moves lengthwise relative to the primary tape rule to adjust for relative length changes while rolling. For the longest extension type tasks the secondary tape rule 12 trailing edge exits the housing 16 . This minimizes material within the housing 16 when fully retracted and results in a smaller, lighter weight assembly. The combined tape rule assembly retracts in the usual manner and the section is induced to collapse by rolling around the reel 18 .

There are other ways in which this layer beam measurement apparatus of this disclosure may be embodied. For example, in one embodiment, the secondary tape is affixed at the leading edge using an assembly that allows lengthwise relative motion of tapes. The secondary tape trailing edge may extend to the primary tape rule reel interface, or the secondary tape rule leading edge may extend to the primary tape rule hook interface. It is contemplated that the secondary tape rule may be rigidly affixed using welds, adhesive or rivets at leading edge and affixed in such a way as to allow lengthwise relative motion of tapes at the trailing edge. Alternatively either rule may be bent or formed at its leading edge(s) to overlap and capture the other rule.

In various embodiments, the primary tape rule may have a varying thickness, width, or radius as compared to the secondary tape rule. It is contemplated that another secondary rule 122 , as shown in FIG. 1 , or any number of secondary rules may be employed, and they may be deployed progressively or simultaneously as the tape rule assembly extends.

In one preferred embodiment, the primary and secondary tape rules may be mounted on separate reels 19 within housing to allow independent motion between tapes, as shown in FIG. 4 . The secondary tape may be mounted to allow relative motion at both ends, or mounted to allow lengthwise relative motion at both leading and trailing edges.

It is further contemplated that the primary rule may be marked with measurement indicia, however the secondary tape may include marking indications as well. The two tapes may be marked in such a way to provide interaction features between the primary tape rule and secondary tape rule. For example, markings on the two tapes may be configured to provide variant measurement systems, units or arithmetic tools.

In terms of construction, it is contemplated that the secondary tape may comprise a convexo-concave orientation.

Additionally, it is contemplated that the hook will normally be affixed to the primary tape, however, the secondary tape may also includes a hook or plurality of hooks. Alternate materials may be used for the primary and secondary tape rule sections, such as steel, plastic, resin impregnated fibrous cloth, or a combination of these.

The tape assembly may also be constructed of a single tape rule with varying thickness or a single tape rule with a varying curve that is flatter at the leading edge, and gradually changes to a deeper curve near the trailing edge of the tap.

The tape assembly may also be constructed of a single tape rule incorporating a shape memory element such that when the tape is extended to greater lengths the tape rule either manually or automatically changes its cross section to a deeper curve down its entire length or alternatively near known lengths of excessive bending or folding.

As will now be appreciated, a new, improved tape rule that increases stiffness and standout length over standard tape rules has been described. This invention can provide a variety of benefits, including increased blade flexibility while performing short extension related tasks, increased standout and reduced sag while performing tasks requiring longer extensions, reduced size and weight for tasks requiring the longest extensions and adds the ability to utilize alternate measurement methods or units and built in computational references.

While embodiments and applications of this invention have been shown and described, it will now be apparent to those skilled in the art having the benefit of this disclosure that many more modifications than mentioned above are possible without departing from the inventive concepts disclosed herein.