(12) United States Patent
`Murray
`
`111111111111111111111111111111111111111111111111111111111111111111111111111
`US006324769Bl
`US 6,324,769 Bl
`Dec. 4, 2001
`
`(10) Patent No.:
`(45) Date of Patent:
`
`(54) RULE ASSEMBLY WITH INCREASED
`BLADE STANDOUT
`
`(75)
`
`Inventor: John C. Murray, Canton, CT (US)
`
`(73) Assignee: The Stanley Works, New Britian, CT
`(US)
`
`( *) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 0 days.
`
`(21) Appl. No.: 09/366,781
`
`(22) Filed:
`
`Aug. 4, 1999
`
`Int. Cl? ....................................................... GOlB 3/10
`(51)
`(52) U.S. Cl. .................................. 33/755; 33/757; 33/769
`(58) Field of Search .............................. 33!755, 757, 559,
`33/760, 761, 769; 242/381.3, 381.6
`
`(56)
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`1,730,199 * 10/1929 Farrand ............................. 242/396.6
`2,050,941 * 8/1936 Farrand .................................. 33/771
`2,809,142 * 10/1957 Beeber eta!. ......................... 33/770
`3,630,104 * 12/1971 Milner .................................... 81/487
`3,716,201 * 2/1973 West .................................. 242/375.2
`4,352,244 * 10/1982 Tomuro .................................. 33/757
`4,429,462 * 2/1984 Rutty et a!. ............................ 33/757
`4,487,379 * 12/1984 Drechsler et a!.
`................ 242/375.2
`4,578,867 * 4/1986 Czerwinski et a!. ................. 242/375
`4,930,227 * 6/1990 Ketchpel ................................ 33/755
`4,976,048 * 12/1990 Blackman .............................. 33/767
`5,210,956 * 5/1993 Knispel et a!.
`........................ 33/761
`5,699,623 * 12/1997 Lee ......................................... 33/758
`
`5,806,202 * 9/1998 Blackman et a!. ..................... 33/767
`6,243,964 * 6/2001 Murray ................................... 33/769
`6,282,808 * 9/2001 Murray ................................... 33/769
`* cited by examiner
`Primary Examiner-Andrew H. Hirshfeld
`Assistant Examiner-R. A Smith
`(74) Attorney, Agent, or Firm-Pillsbury Winthrop LLP
`
`(57)
`
`ABSTRACT
`
`A retractable rule assembly includes a housing assembly and
`a reel rotatably mounted in the housing assembly. An
`elongated blade formed of a ribbon of metal having one end
`connected to the reel is constructed and arranged with
`respect to the housing assembly to extend from a position
`tangential to the reel outwardly through a spaced opening in
`the housing assembly. A coil spring formed of a ribbon of
`metal has a construction and arrangement between the
`housing assembly and the reel to rotate the reel in the
`housing assembly in a direction to wind up the elongated
`blade when extending outwardly of the housing assembly
`opening in a normal concavo-convex cross-sectional con(cid:173)
`figuration onto the reel in an abutting volute coil formation
`in a flattened cross-sectional configuration. A blade holding
`assembly is constructed and arranged to be manually actu(cid:173)
`ated to hold the blade in any position of extension outwardly
`of the housing assembly opening and to release the blade
`from any position in which it is held. The blade has a blade
`width, thickness and height of concavo-convex curvature
`sufficient to enable the blade to stand out arcuately a length
`measured along the blade of at least 10.5 feet with a
`horizontal linear length of standout thereof being greater
`than 97% of the arcuate length of standout.
`
`29 Claims, 10 Drawing Sheets
`
`Rl
`
`'
`'
`! -W - - j
`
`!BLADE PROJECTION ANGLE -EXITING TAPE CASE)
`
`IIQ ~~~~OROONTAl POSITION -~EGRESS
`"A"l ~ "B"
`
`---t
`
`I
`
`APEX TOOL GROUP, LLC - EX. 1010-001
`
`

`

`U.S. Patent
`
`Dec. 4, 2001
`
`Sheet 1 of 10
`
`US 6,324,769 Bl
`
`40 48
`
`108 59 12
`
`44
`
`®r-- 68
`
`136
`
`204
`
`161
`
`FIG. 1
`
`APEX TOOL GROUP, LLC - EX. 1010-002
`
`

`

`U.S. Patent
`
`Dec. 4, 2001
`
`Sheet 2 of 10
`
`US 6,324,769 Bl
`
`110
`
`10~
`
`204
`
`40
`
`48
`
`108
`
`77
`
`96
`
`128 129
`126 22
`
`162 20
`
`FIG. 2
`
`APEX TOOL GROUP, LLC - EX. 1010-003
`
`

`

`U.S. Patent
`
`Dec. 4, 2001
`
`Sheet 3 of 10
`
`US 6,324,769 Bl
`
`10
`~
`
`108
`
`68 '®38
`
`6~
`
`FIG. 3
`
`162
`96
`160
`
`152
`161
`107 163 177
`
`APEX TOOL GROUP, LLC - EX. 1010-004
`
`

`

`U.S. Patent
`
`Dec. 4, 2001
`
`Sheet 4 of 10
`
`US 6,324,769 Bl
`
`FIG. 4
`
`APEX TOOL GROUP, LLC - EX. 1010-005
`
`

`

`U.S. Patent
`
`Dec. 4, 2001
`
`Sheet 5 of 10
`
`US 6,324,769 Bl
`
`108
`
`82
`
`131
`200
`58
`7
`2
`111 r==:tti:..J~F~~=---1-
`11
`
`FIG. 5
`
`98
`
`APEX TOOL GROUP, LLC - EX. 1010-006
`
`

`

`U.S. Patent
`
`Dec. 4, 2001
`
`Sheet 6 of 10
`
`US 6,324,769 Bl
`
`78-hL.
`
`62
`75
`79
`
`12
`46
`64
`78
`15
`74
`
`68 ~~~~~~~r-68
`
`70
`76
`73
`
`108
`
`FIG. 6
`
`APEX TOOL GROUP, LLC - EX. 1010-007
`
`

`

`U.S. Patent
`
`Dec. 4, 2001
`
`Sheet 7 of 10
`
`US 6,324,769 Bl
`
`co
`u..l9
`LL
`
`APEX TOOL GROUP, LLC - EX. 1010-008
`
`

`

`1--"
`~
`\0
`0'1
`~
`~
`N
`~
`0'1
`rJ'l
`e
`
`"""' c
`0 ......,
`00
`~ ......
`'JJ. =(cid:173)~
`
`"""'
`N c c
`
`~.J;;..
`!"l
`~
`~
`
`"""'" ~ = """'"
`
`~
`~
`
`\Jl .
`d .
`
`>45
`>45
`>45
`>45
`>45
`=1<25
`=1<35
`>45
`>45
`>45
`>45
`
`AT FULL
`ANGLE "D"
`ROTATION
`TAPE RULE
`MAXIMUM
`
`****
`
`98%
`99%
`99%
`99%
`99%
`86%
`95%
`96%
`90%
`95%
`94%
`
`IT
`
`Ll
`
`LINEAR TO
`PERCENT
`
`38
`30
`17
`8
`5
`53
`31
`18
`40
`22
`23
`
`'Yo]
`
`EXTENSION
`FULL BLADE
`TO ACHIEVE
`
`HEIGHT
`REQUIRED
`TAPE RULE
`
`LENGTH-OUT
`***LINEAR
`
`****ROTATION ANGLE REQUIRED WHEN MEASURING VERTICAL POINTS ABOVE HORIZONTAL PLANE OF BLADE TIP
`*** AOUAL UTILITY OF TAPE BLADE STANDOUT
`** RAW STEEL THICKNESS WITHOUT COATINGISI
`* BLADE WIDTH MEASURED IN FLAT FORM OR ARCUATE PERIMETER OF THE CROSS SECTION
`1.250 I 1.250
`1.250 I 1.250
`1.250 I 1.250
`1.250 I 1.250
`1.250 I 1.250
`1.000 I 0.875
`1.000 I 0.875
`1.000 I 0.875
`1.000 I 0.875
`1.000 I 0.875
`1.000 I 0.875
`WIDTHIINI
`
`FIG. 9
`
`129
`119
`107
`95
`83
`93
`91
`81
`86
`80
`79
`
`[R,
`
`7o)
`
`[~
`
`132 I 11FT
`120 I 10FT
`108 I 9FT
`96 I 8FT
`84/7FT
`108 I 9FT
`96 I 8FT
`84 I 7FT
`96 I 8FT
`84 I 7FT
`84 I 7FT
`
`!RANGE tl-6 IINII
`
`"C" liN I FTI
`LENGTH-OUT
`"ARCUATE"
`
`0.0051 I 0.0051
`0.0051 I 0.0051
`0.0051 I 0.0051
`0.0051 I 0.0051
`0.0051 I 0.0051
`0.0056 I 0.0060
`0.0056 I 0.0060
`0.0056 I 0.0060
`0.0051 I 0.0056
`0.0051 I 0.0056
`0.0045 I 0.0051
`THICKNESS (IN]
`*BLADE I SPRING
`
`0...
`c:l<::
`0
`c:l<::
`<(
`l:i2
`
`*BLADE I SPRING
`
`APEX TOOL GROUP, LLC - EX. 1010-009
`
`

`

`U.S. Patent
`
`Dec. 4, 2001
`
`Sheet 9 of 10
`
`US 6,324,769 Bl
`
`[Lj
`(,/")
`
`(,/")
`(,/")
`LJ.J
`0.:::::
`~
`LJ.J
`0 =
`•U
`0 =
`z:
`0
`I--
`(./')
`
`0 a..
`___.
`~
`:z:
`0
`N
`02
`0
`:r:
`
`0
`
`0
`.
`r--
`(.9
`-
`u...
`
`co
`=
`
`<( u
`LJ.J a..
`~
`~
`z:
`i=
`><
`LJ.J
`I
`___.
`LJ.J
`~
`z:
`<(
`z:
`0
`b
`a
`::s e
`
`LJ.J
`
`0.:::::
`CL
`LJ.J
`0
`
`APEX TOOL GROUP, LLC - EX. 1010-010
`
`

`

`U.S. Patent
`
`Dec. 4, 2001
`
`Sheet 10 of 10
`
`US 6,324,769 Bl
`
`42
`
`FIG. 11
`
`APEX TOOL GROUP, LLC - EX. 1010-011
`
`

`

`US 6,324,769 Bl
`
`1
`RULE ASSEMBLY WITH INCREASED
`BLADE STANDOUT
`
`The present invention is generally related to retractable
`tape rule assemblies and more particularly to tape rule
`assemblies of the spring retractable type.
`
`BACKGROUND OF THE INVENTION
`
`Spring retractable rule assemblies have been available
`commercially for many years. One of the most desirable
`characteristics commercial rule assemblies can possess is a
`relatively long blade standout. To date, as a practical matter,
`that standout length of most blades has rarely exceeded 7
`feet or at most approximately 9 feet. Standout is generally
`measured by the length of the rule assembly blade that can
`be extended in a self-sustaining manner without the blade
`buckling under its own weight. An important characteristic
`of standout relates to the vertical bend that the blade takes
`in its maximum self-sustained extension. This is generally
`expressed in terms of the height the housing assumes from
`a horizontal surface when the free end of the blade is just
`touching the horizontal surface. The vertical height of the
`housing above the horizontal surface, the position at which
`the free end of the blade touches the horizontal surface and
`the vertical projection of the position of the housing onto the
`horizontal surface roughly define three points of a right
`angle triangle. The hypotenuse of the triangle represents a
`close approximation of the actual length of the blade extend(cid:173)
`ing from the housing and the horizontal leg of the triangle
`represents the linear horizontal extension of the blade. It is
`generally recognized to be desirable to maintain the ratio
`between the linear horizontal extension to the actual exten(cid:173)
`sion as near to one as possible. There always exists a need
`to provide a retractable rule assembly that will provide 35
`greater standout with a greater ratio of linear horizontal
`standout to actual standout.
`
`30
`
`2
`Preferably, the width of the elongated blade in its flattened
`configuration is within the range of 1.10"-1.5"; the height of
`the elongated blade in its concavo-convex configuration is
`within the range of 0.25"--0.40"; and the thickness of the
`elongated blade in either configuration thereof is within the
`range of 0.0045" to 0.0063".
`The geometry of the cross-section of the extended blade
`is also important in increasing blade standout. Preferably,
`the concavo-convex cross-sectional configuration of the
`10 elongated blade includes an arcuate central section having a
`predetermined radius of curvature and integral arcuate end
`sections each having the same radius of curvature (i.e., the
`radius of curvature of one integral arcuate end section is
`equal to the radius of curvature of the opposite integral
`15 arcuate end section); preferably, the radius of curvature of
`the central section is a dimension within the range of 0.35"
`to 0.60" and the radius of curvature of each end section is a
`dimension within the range of 1.0" to 5.0".
`It is contemplated to provide a wide range of tape assem-
`20 bly embodiments having increased blade standout. More
`particularly, in the more specific aspects of the present
`invention, it is a further objective to provide a retractable
`rule assembly having a blade constructed according to the
`principles briefly described above to provide the improved
`25 standout characteristics previously described with any com(cid:173)
`bination of the following additional features:
`1. A retractable rule assembly wherein a relatively short
`free end portion of the blade has a clear film of plastic
`material adhered to a concave side thereof.
`2. A retractable rule assembly wherein the metal ribbon of
`the spring has a width which is 95%-120% of the width of
`the metal ribbon of the blade.
`3. A retractable rule assembly wherein the blade has an
`end hook member on the free end thereof, the end hook
`member being formed of sheet metal of a predetermined
`thickness to include a concavo-convex mounting portion
`having a U-shaped hook portion bent at a generally right
`angle from an end thereof, the end hook member being
`40 mounted on the free end of the blade with the mounting
`portion thereof secured in limited sliding engagement with
`a concave side of the free end of the blade so that the rule
`can be measured externally from an exterior surface of the
`U-shaped hook portion or internally from an interior surface
`of the U-shaped hook portion, the U-shaped hook portion
`including a bight section extending transversely from a
`convex side of the free end of the blade and spaced leg
`sections extending beyond transversely spaced corners of
`the free end of the blade.
`4. A retractable rule assembly wherein the housing assem(cid:173)
`bly includes a pair of cooperating housing members, each
`including an end wall having a peripheral wall extending
`from a periphery thereof and terminating in a free edge, the
`housing members being fixed together with their free edges
`interengaged by a plurality of bolts extending through one of
`the housing members and threadedly engaged in the other at
`spaced positions adjacent the peripheral walls thereof and by
`a fixed reel spindle having a non-circular interengaging
`recess-projection connection at each end thereof with the
`central interior of the adjacent end wall, each end of the
`spindle being interiorly threaded to threadedly receive a bolt
`therein extending through a central hole in the adjacent end
`wall and the recess-projection connection between the cen(cid:173)
`tral hole and threaded interior.
`5. A retractable rule assembly wherein the housing assem(cid:173)
`bly includes a fitment defining a part of the housing assem(cid:173)
`bly opening adjacent a convex side of the blade, the fitment
`
`BRIEF DESCRIPTION OF THE INVENTION
`
`An objective of the present invention is to fulfill the need
`expressed above. In accordance with the principles of the
`present invention, this objective is achieved by providing a
`retractable rule assembly that includes a housing assembly
`and a reel rotatably mounted in the housing assembly. An
`elongated blade formed of a ribbon of metal is mounted on 45
`the reel. One end of the blade is connected to the reel. The
`blade is constructed and arranged with respect to the housing
`assembly to extend from a position tangential to the reel
`outwardly through a spaced opening in the housing assem(cid:173)
`bly. A coil spring that is formed of a ribbon of metal has a 50
`construction and arrangement between the housing assem(cid:173)
`bly and the reel to rotate the reel in the housing assembly in
`a direction to wind the elongated blade about the reel when
`the blade is extending outwardly of the housing assembly
`opening. The blade has a "normal" concavo-convex cross- 55
`sectional configuration when extended and has a fiat cross(cid:173)
`sectional configuration when it is wound about the reel so
`that the wound reel is disposed about the reel in an abutting
`volute coil formation. A blade holding assembly is provided
`which is manually actuated to hold the blade in any position 60
`of extension outwardly of the housing assembly opening and
`to release the blade from any position in which it is held. The
`blade has a blade width, thickness and height of concavo(cid:173)
`convex curvature sufficient to enable the blade to stand out
`arcuately a length measured along the blade of approxi- 65
`mately 11 feet with a horizontal linear length of standout
`thereof greater than 97% of the arcuate length of standout.
`
`APEX TOOL GROUP, LLC - EX. 1010-012
`
`

`

`US 6,324,769 Bl
`
`3
`having a plurality of tangentially extending transversely
`spaced elongated ridges defining surfaces for engaging the
`convex side of the blade extending tangentially from the reel
`to said housing assembly opening.
`6. The housing assembly includes a bottom wall having an
`exterior portion at an end position adjacent the housing
`assembly opening which projects below the exterior surface
`portion extending therefrom toward an opposite end to
`provide a finger grip enhancing configuration.
`7. The housing opening has a height dimension which
`exceeds the height dimension of the blade an amount that is
`at least approximately equal to the amount the hook portion
`extends below the bottom end surface of the housing assem(cid:173)
`bly at the housing opening.
`In the broader aspects of the present invention, it is an
`objective to provide any known retractable rule assembly
`with improved blade standout by constructing a blade there(cid:173)
`for to have the blade cross-sectional geometry briefly
`described above and/or the blade dimensions as previously
`described.
`These and other objectives, features, and advantages of
`the present invention will become apparent from the fol(cid:173)
`lowing detailed description, the accompanying drawings,
`and the appended claims.
`
`DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 shows a perspective view of a tape rule assembly
`constructed according to the principles of the present inven(cid:173)
`tion;
`FIG. 2 shows a front of elevational view of the tape rule
`assembly;
`FIG. 3 shows a side of elevational view of the tape rule
`assembly;
`FIG. 4 shows a cross-sectional view of the tape rule
`assembly taken through the line 4---4 in FIG. 2 showing a
`blade thereof in a fully retracted configuration;
`FIG. 5 is a view similar to FIG. 4 except showing the
`blade in a fully extended configuration;
`FIG. 6 is a cross-sectional view taken through the line
`6-6 in FIG. 3;
`FIG. 7 is a transverse cross-sectional view taken through
`a portion of the extended blade;
`FIG. 8 is a transverse cross-sectional view taken through
`a portion of the blade when the blade is in a flattened
`configuration;
`FIG. 9 is a table showing a comparison of the construction
`and standout characteristics of a plurality of exemplary prior
`art tape rule assemblies with an embodiment of the tape rule
`assembly constructed according to the principles of the
`present invention;
`FIG. 10 is a schematic representation of an extended tape
`blade extending from a housing assembly to illustrate the
`linear length-out, arcuate length-out of the blade and the
`rotational angle of the housing assembly; and
`FIG. 11 is a cross-sectional view of a fragment of the tape
`rule assembly taken through the line 11-11 of FIG. 4.
`
`50
`
`DETAILED DESCRIPTION OF THE
`INVENTION
`FIGS. 1-3 show an exterior view of a retractable rule
`assembly that is generally designated 10 and is constructed
`according to the principles of the present invention. The rule 65
`assembly 10 includes a housing assembly 12 and a reel14
`that is rotatably mounted inside the housing assembly 12
`
`20
`
`25
`
`4
`(best seen in the cross-sectional views of FIGS. 4--6). The
`reel 14 is mounted in the housing assembly 12 by a reel
`spindle 15 that is secured within the housing assembly 12
`(FIGS. 4-6). An elongated tape rule blade 16 is mounted on
`the reel14.
`The blade 16 is formed of a ribbon of metal, the preferred
`metal being steel, and the top concave surface of the blade
`is printed with measuring lines and digits (not shown) for
`measuring lengths and distances. One longitudinal end 18 of
`10 the blade 16 is connected to the reel 14 and a second
`longitudinal free end 20 of the blade 16 extends generally
`outwardly of the reel 14. The blade 16 is constructed and
`arranged with respect to the housing assembly 12 to extend
`generally from a position tangential of the reel14 outwardly
`15 through a spaced opening 22 provided in the housing
`assembly 12 (as shown, for example, in FIG. 4).
`Preferably the reel14 is made of a molded plastic and is
`provided with slots or openings 24, 26 in a central cylin(cid:173)
`drical wall portion 28 thereof. The one end 18 of the blade
`terminates in a hook-like structure 30 that hookingly
`engages an edge of the wall portion 28 of the reel 14 at
`opening 24 to connect the end 18 of the blade 16 to the reel
`14 (FIGS. 4, 5).
`A coil spring 32 has a construction and arrangement
`between the housing assembly 12 and the reel14 to rotate
`the reel 14 with respect to the housing assembly 12 in a
`direction to wind the elongated blade 16 about the reel when
`the blade 16 is extending outwardly of the housing assembly
`30 opening 22. The coil spring 32 is generally enclosed within
`the central wall portion 28 of the reel14 (FIGS. 4-6). One
`longitudinal end 35 of the coil spring 32 hookingly engages
`an edge of the wall portion 28 of the reel14 that defines the
`opening 26; a second longitudinal end 37 of the blade 16
`35 hookingly engages the spindle 15. The spindle 15 is rigidly
`mounted to the housing assembly 12 in a manner considered
`in detail below. Preferably the spring 32 is a thin, fiat ribbon
`of metal, the preferred metal being steel.
`The blade 16 is generally movable between a fully
`40 retracted position outwardly of the housing assembly 12 to
`a fully extended position. The fully retracted position of the
`blade 16 is shown in FIG. 4 and the fully extended position
`of the blade is shown (in fragmentary view) in FIG. 5. It can
`be appreciated from a comparison of FIG. 4 and FIG. 5 that
`45 as the blade is unwound from the reel14, the coil spring 32
`is wound around the rigidly fixed spindle 15. This winding
`of the spring around the spindle stores energy in the spring
`to provide spring powered rewinding of the blade 16 around
`the reel 14 when the extended blade is released.
`The blade 16 is constructed of a ribbon of sheet metal that
`is shaped during the manufacturing to have a normal or
`memory configuration that has a generally arcuate or
`concavo-convex transverse cross-section. When a portion of
`the blade 16 is wound about the reel14, the wound portion
`55 has a fiat transverse cross-section (FIGS. 6 and 8) and the
`wound layers of the coiled blade provide the wound blade
`with an abutting volute coil configuration. A representative
`transverse cross-section of the extended blade 16 showing
`its concavo-convex configuration is illustrated in FIG. 7. It
`60 can therefore be understood from a comparison of FIGS. 4-5
`(and from a comparison of FIGS. 7-8) that when the blade
`16 is wound around the reel14, it has the fiat cross-section
`of FIG. 8 and when the blade 16 is withdrawn from the
`housing assembly 12 to measure an object, it returns to the
`concavo-convex cross-section shown in FIG. 7. Thus, the
`coil spring 32 is constructed and arranged between the
`housing assembly 12 and the reel 14 to rotate the reel 14
`
`APEX TOOL GROUP, LLC - EX. 1010-013
`
`

`

`US 6,324,769 Bl
`
`5
`about the spindle with respect to the housing assembly 12 in
`a direction to wind up the elongated blade 16 when extend(cid:173)
`ing outwardly of the housing assembly opening 22 in a
`normal concavo-convex cross-sectional configuration onto
`the reel14 in an abutting volute coil formation in a flattened
`cross-sectional configuration. The concavo-convex cross(cid:173)
`section provides the extended blade with rigidity and main(cid:173)
`tains the blade essentially straight in the longitudinal direc(cid:173)
`tion.
`The concavo-convex cross-section of the blade generally 10
`provides the unsupported blade 16 with blade standout. As
`described in greater detail below, the blade 16 has a blade
`width, thickness and height of concavo-convex curvature
`sufficient to enable the blade 16 to standout arcuately a
`length measured along the blade of at least 10.5 feet with a
`horizontal linear length of standout thereof that is greater
`than 97 percent of the arcuate length of standout. As also
`described in greater detail below, the concavo-convex trans(cid:173)
`verse cross-section of the blade 16 is provided with a
`geometry that also improves blade standout.
`Generally, one skilled in the art will understand that the
`length of blade standout depends on many factors, including
`(but not limited to) blade width (i.e. the transverse width of
`the blade measured when the blade is in its flattened con(cid:173)
`dition shown, for example, in FIG. 8 and designated F); the
`height of the blade 16 in the concavo-convex configuration
`(designated H in FIG. 7); blade thickness (designated Tin
`FIG. 7); and the geometry of the blade transverse cross(cid:173)
`section when the same is in its normal concavo-convex than
`configuration. Preferably, the blade 12 has a width in the 30
`flattened condition thereof having a dimension within the
`broad range of from approximately 1.10 inches to approxi(cid:173)
`mately 1.5 inches; a height H in the concavo-convex con(cid:173)
`figuration thereof having a dimension within the broad range
`of approximately 0.25 inch to approximately 0.40 inch; and 35
`a thickness in either configuration thereof having a dimen(cid:173)
`sion within the broad range of approximately 0.0045 inch to
`approximately 0.0063 inch. More preferably, the blade 12
`has a width in the flattened condition thereof having a
`dimension within the narrower range of from approximately 40
`1.25 inches to approximately 1.39 inches; a height H in the
`concavo-convex configuration thereof having a dimension
`within the narrower range of approximately 0.30 inch to
`approximately 0.35 inch; and a thickness in either configu(cid:173)
`ration thereof having a dimension within the narrower range 45
`of approximately 0.005 inch to approximately 0.0056 inch.
`Most preferably the blade 16 width is approximately 1.25
`inch, the blade height H is approximately 0.32 inch and the
`blade thickness T is approximately 0.0051 inch. A blade
`constructed according to these principles has a blade stand- 50
`out of up to approximately 13 feet. More specifically, a blade
`construction having dimensions within the broadest ranges
`identified immediately above for the width F, height H and
`thickness T can have a blade standout in the preferred broad
`range of at least 10.5 feet to approximately 13 feet; a blade 55
`construction having dimensions within the more preferred
`narrower ranges identified immediately above for the width
`F, height H and thickness T can have a blade standout in the
`range of at least 10.5 feet to approximately 12.5 feet; and a
`blade construction having the most preferred dimensions 60
`identified immediately above for the width F, height H and
`thickness T has a blade standout of approximately 11 feet.
`The concavo-convex cross-section of the blade 16 has a
`unique geometry (shown in FIG. 7) that increases in the
`standout ability. The concavo-convex cross-sectional con- 65
`figuration of the blade 16 includes an arcuate central section
`36 and integral arcuate end sections 38. Each arcuate end
`
`6
`section 38 has the same radius of curvature (indicated for
`one of the two end sections 38 in FIG. 7 by the line
`designated R1). The central section 36 has a radius of
`curvature designated R2 (FIG. 7). The radii of curvature R1
`for the two end sections 38 are greater than the radius of
`curvature R2 of the central section 36. The central section
`having a radius R2 extends through an angular extent
`designated X in FIG. 7. Preferably angle X is approximately
`84 degrees.
`Preferably the arcuate central section 36 has a radius of
`curvature R2 that is a dimension within the broad range of
`approximately 0.30" to approximately 0.60"; and the radius
`of curvature R1 of each end section 38 is a dimension within
`the broad range of approximately 1.0" to approximately
`15 5.0". More preferably the arcuate central section 36 has a
`radius of curvature R2 that is a dimension within the
`narrower range of approximately 0.40" to approximately
`0.50" and the radius of curvature R1 of each end section 38
`is a dimension within the narrower range of approximately
`20 2.0" to approximately 4.0". Most preferably, the arcuate
`central section 36 has a radius of curvature R2 of approxi(cid:173)
`mately 0.46" and the radius of curvature of each end section
`R1 is approximately 3.0".
`The transverse cross-sections of prior art tape blades are
`25 either constant curves (i.e., constant radius of curvature) or
`are constant curves in the center of the blade with straight
`(i.e. fiat) sections at each transverse end of the cross-section
`when the blade is extended. Blades constructed to have
`either these basic cross-sections are less stable during blade
`standout and show a greater tendency to buckle than blades
`having cross-sections constructed according to the present
`invention.
`FIG. 9 shows a comparison of the construction and
`standout capabilities of three prior art rule assemblies
`(shown in the first six rows of the table and indicated with
`a bracket) with a preferred embodiment of the rule assembly
`10 constructed according to the principal of the present
`invention (shown in the last five rows of the table). As the
`first column of FIG. 9 indicates, typical prior art rule blades
`did not exceed one inch in width (measured in the flattened,
`coiled configuration of the blade). The second column
`indicates that prior art blade thickness for a one inch blade
`ranged from 0.0045 inch to 0.0056 inch and produced blade
`having a standout length of from approximately 7 feet to
`approximately 9 feet as indicated in FIG. 9, the third
`column.
`The embodiment of the rule assembly constructed accord(cid:173)
`ing to the principles of the present invention shown in FIG.
`9 has a blade width of 1.250 inches (in the fiat configuration)
`and a blade thickness of 0.0051 inch. Preferably, the blade
`described in FIG. 9 has a concavo-convex cross-section in
`the extended configuration as described above and as shown
`in FIG. 8.
`The last five columns in FIG. 9 compare the standout
`characteristics of the three prior art tape assemblies with the
`tape assembly 10 constructed according to the principles of
`the invention. The standout characteristics of the blade of a
`given tape assembly are best understood by comparing the
`arcuate (i.e., actual) length-out measured along the surface
`of the blade with the linear length-out of the blade. These
`two characteristics are often expressed as a percentage of
`linear length-out to arcuate length-out. FIG. 10 shows a
`schematic diagram that illustrates what is meant by arcuate
`length-out and linear length-out.
`Arcuate length-out is represented by arcuate line C in
`FIG. 10 and is a measure of the total length of the extended
`
`APEX TOOL GROUP, LLC - EX. 1010-014
`
`

`

`US 6,324,769 Bl
`
`7
`portion of the blade. Linear length-out is designated B in
`FIG. 10 and is a measure of the linear length of the
`projection of the extended blade on an imaginary horizontal
`surface below the tape assembly 10. Line A designates the
`height the housing assembly 10 is required to be above the
`horizontal surface when the housing assembly 12 is angu(cid:173)
`larly oriented with respect to the surface at an angle D to
`position the arcuately extending blade so that the free end
`thereof just touches the surface. Thus, angle D generally
`represents the degree of tape rule housing assembly rotation
`(with respect to the horizontally extending surface) required
`to achieve maximum standout for a given length of extended
`tape.
`The comparison of the prior art and the present invention
`given in FIG. 9 indicates that the maximum prior art arcuate
`length-out that could be achieved with a one inch wide blade
`was approximately nine feet. Because of the relatively
`shallow (relative to the present invention) cross-sectional
`blade height H of approximately 0.21 inch (not shown in
`FIG. 9) typically used in prior art one inch blades and
`because of the relatively high thickness of the metal of the
`prior art blades (which thickness is required for the arcuate
`length-out to be achieved), however, the linear length-out B
`was approximately 93 inches. This results in a percent of
`linear to arcuate length-out of approximately 86 percent. It
`can be appreciated that the third embodiment of the prior art
`shown in the fourth through the sixth rows of FIG. 9 shows
`relatively little bending for seven feet of standout (96%
`linear to arcuate length-out), but that this embodiment bends
`a very large degree when two additional feet of the blade are 30
`extended. This high degree of arcuate bending of the 1 inch
`blade at standout lengths approaching 9 feet makes the task
`of measuring a large distance difficult for a single person
`using the prior art tape rule assembly. As indicated in FIG.
`9, the present invention provides a rule assembly that can 35
`achieves seven feet to approximately 11 feet of arcuate
`length-out while maintaining the percent of linear to arcuate
`length-out in the approximate range of 99 percent to 98
`percent. This greatly facilitates the task of measuring a
`length for the tape assembly user. Greater degrees of stand- 40
`out with a comparable percentage of linear to arcuate
`length-out can be achieved by making the blade wider. It is,
`for example, within the scope of the present invention to
`provide a blade width of 1.5 inches or greater.
`It can be understood by one skilled in the art that the 1.25 45
`inch blade width of a preferred embodiment of the assembly
`10 allows the blade height H to be increased without
`increasing the overall blade curvature to a degree that would
`make reading the gradations and lettering printed on the
`concave surface of the blade 16 difficult. This construction 50
`results in a blade with relatively high height H that is also
`easy to read. (In contrast, one inch blades having a curve
`height of the extended blade of over 0.21 become very
`difficult to read and are thus not commercially practical.)
`Increasing the blade width of the blade of the present 55
`invention also allows the printing on the blade to be made
`larger, thus making measurements easier by making the
`blade easier to read. When the preferred 1.25 inch blade (fiat
`width F) is in its concavo