Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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The present invention relates generally to crank
operated tape measures and is more particularly concerned with
a new and improved reel lock for crank operated tape measures.
It is a principal aim of the present invention to
provide in a crank operated tape measure a new and improved
reel lock for ],ocking the measuring tape against unwinding
after a selected length of tape is unreeled. Included in this
aim is the provision of a tape measure reel lock which permits
a user, after hooking the frce end of the measuring tape at a
measuri,ng point, to pull the tape taut with the tape measure
case and without having to hold the tape reel crank to keep the
tape from paying out.
It is another aim of the present invention to provide
a new and improved tape measure reel lock that is automatically
disengaged in conjunction with reeling in the measuring tape.
It is another aim of the present invention to
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provide a new and improved manually operable tape measure
reel lock of economical construction which is adapted to
be manually operated between locking and unlocking posi-
tions and which is frictionally retained in each position
against unintended operation.
It is still another aim of the present invention
to provide a new and improved tape measure reel lock of
the type described that is particularly well suited for
long tapes having a length of fifty feet or more.
It is a further aim of the present invention to
provide a new and improved tape measure reel lock of eco-
nomical and yet rugged and durable construction that is
well suited to rapid assembly.
Other objects will be in part obvious and in
part pointed out more in detail hereinafter.
A better understanding of the invention will be
obtained from the following detailed description and the
accompanying drawing of an illustrative application of the
invention.
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In the drawing:
Fig. 1 is a side view of a tape measure incor-
porating a preferred embodiment of a reel lock of the pre-
sent invention, showing the measuring tape fully withdrawn;
Fig. 2 is a front end view, partly broken away
and partly in section, of the tape measure;
Figs. 3 and 4 are enlarged section views, partly
in section, of a reel and a reel locking slide of the tape
measure, showing respectively the reel locked by the slide
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against paying out the measuring tape and the slide engaged
by the reel to release the lock;
Fig. S is an enlarged partial section view,
partly broken away and partly in section, showing the
locking slide in full lines in its withdrawn unlocking
position and in part in broken lines in its intermediate
and locking positions;
Fig. 6 is an enlarged partial side view, partly
broken away and partly in section, of the tape measure
showing the locking slide in its withdrawn unlocking posi-
tion; and
Fig. 7 is an enlarged partial transverse section
view, partly broken away and partly in section, taken sub-
stantially along line 7-7 of Fig. 5.
Referring now to the drawing in greater detail
wherein like reference numerals indicate like parts through-
out the several figures, a tape measure 10 incorporating a
preferred embodiment of the present invention has a case 11
consisting of a pair of mating side members 12, 14 which,
in their assembled condition, define an intermediate tape
storage cavity 16, open at its front and rear ends, for
storing a long measuring tape or blade 20 of, for example,
fifty feet long or more. A slotted receptacle 21 for a
blade hook 23 is shown provided at the lower front end of
the casing 11. The mating side members 12, 14 of the case
11 have sidewalls 22, 24 respectively with slightly con-
cave exterior surfaces at generally central portions there-
of. The side member 12 has an enlarged circular central
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aperture 28 in its sidewall 22 with a radially extending
lip 30 defining its periphery. The interior surface of
sidewall 24 is provided with a center post 32 projecting
a short distance into the interior of the case.
A generally cylindrical cup-shaped molded plastic
reel 38 is mounted within the large central aperture 28
of the side member 12 and has a peripheral flange 40 that
cooperates with the lip 30 of the side member 12 to pre-
vent withdrawal of the reel from the casing. The reel 38
has a pivotal crank 44 for rotating the reel and rewind-
ing the measuring tape 20 to the reel in a generally con-
ventional manner. The reel 38 has a generally cylindri-
cal skirt or drum 46 that extends across the interior of
the case into a coaxial circular groove of the sidewall
24. An axially extending post 50 is provided inwardly
of but generally tangential to the outer cylindrical sur-
face of the drum 46 for securing an inner end loop 52
of the tape 20 to the reel 38. Thus, as will be appre-
ciated, the reel 38 can be manually rotated by the crank
14 to wind the measuring tape 20 onto the drum 46 for
storage within compartment 16.
In accordance with the present invention, the
reel 38 is molded with three e~uiangularly spaced abut-
ments 60 formed by generally V-shaped webs extending
generally radially inwardly from the cylindrical drum 46.
As shown in Figs. 3 and 4, the post 50 is located within
a notch defined by one of the generally V-shaped webs 60
which extends inwardly from the circumferentially spaced
ends of the drum 46.
Each abutment 60 forms two oppositely angularly
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facing flat surfaces 64, 66 respectively at its "leading"
and "trailing" sides relative to unwinding rotation of
the reel 38, in the clockwise direction as viewed in Figs.
3 and 4. The "leading" abutment surfaces 64 are angularly
inclined from a radial to provide a latching surface with
substantially face to face engagement with one side of
the forward end of a molded plastic locking slide 70 as
shown in Fig. 3 for locking the reel 38 against further
unwinding rotation.
The locking slide 70 is mounted on the sidewall
24 opposite the crank 44 and within an elongated slot 72
in the sidewall 24. The slide 70 has a generally flat
depending locking blade 74 adapted to be inserted into
the slot 72. The depending blade 74 has an enlarged
section 76 with an upper flat shoulder or edge 77 adja-
cent to but slightly rearwardly of its forward end, and
the slot 72 has an enlarged section 78 for inserting the
enlarged locking blade section 76 through the slot 72.
Once inserted into the slot 72, the blade 74 is retained
within the slot by the engagement of the flat upper
shoulder 77 with the inside flat face 79 of the sidewall
24 and by an integral resilient tab 80 having an offset
unflexed condition shown in Fig. 7 with an upper flat
edge 83 engaging the inside flat face 79 of the sidewall
24. The tab 80 is made sufficiently resilient to insert
the blade 74 through the slot 72 and the tab 80 then snaps
outwardly to underlie the sidewall 24. For that purpose,
the slot 72 is internally chamfered at 81 to permit the
tab 80 to snap outwardly to underlie the sidewall 24 to
its relaxed position shown in Fig. 7.
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The locking slide 70 has an outer integral base
82 substantially wider than the blade 74 and received with-
in a recess 84 of corresponding width in the sidewall 24.
The base 82 is formed with an outer rear button 86 with
a generally longitudinally curved transversely serrated
face 88 facilitating thumb operation of the slide between
its withdrawn unlocking position shown in full lines in
Fig. S and its fully extended locking position shown in
part in broken lines in Fig. 5.
After the desired length of measuring tape 20
is payed out, the reel 38 can be locked to prevent fur-
ther pay out of the tape 20 by manually shifting the lock-
ing slide 70 to its fully forward position where the for-
ward end of locking slide 70 has face to face engagement
with "leading" surface 64 of an abutment 64. As locking
slide 70 is so shifted, the forwardly extending cantilever
leaf spring member 90 of the slide 70 rides up over an
inclined shoulder or ramp 92 formed in the sidewall 24.
The spring force of the cantilever spring member 90 is
effective in causing the friction between the slide and
the tape casing to retain the slids in its fully forward
locking position. The slide 70 is formed with the canti-
lever spring member 90 and the rear relatively thin wall
section of the button 86 bowed slightly downwardly in
their relaxed state, as shown in part in broken lines in
Fig. 5, to increase the spring force of the cantilever
spring member 90. The forward end 94 of the cantilever
spring member 90 is tapered and the ramp 92 is tapered
to facilitate shifting the locking slide 70 to its fully
forward locking position.
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The "trailing" abutment edge 66 of each abut-
ment 60 is angularly inclined to a radial to provide for
engaging the forward end of the locking blade 74 of the
slide 70 and cam the locking slide 70 rearwardly as the
reel 38 is rotated, in the counterclockwise direction as
viewed in Figs. 3 and 4, to rewind the tape 20 onto the
reel 38. Upon reference to Fig. 4, it can be seen how
the "trailing" cam edge 66 is effective in automatically
retracting the locking slide 70. Also, when the locking
slide 70 is cammed-to an intermediate locking position in
which the locking slide just clears the abutment 60, the
tapered forward end 94 of the cantilever leaf spring 90
is in engagement with the ramp 92 to provide, in combina-
tion with the stored energy of cantilever leaf spring 90,
a snap action return of the slide to its fully retracted
position where it is positively spaced from the abutment
60 by a small clearance. The slope of fixed ramp 92 is
slightly greater than the taper of end 94 of spring member
90 to facilitate this action.
Accordingly, it can be seen that the reel 38
can be selectively locked in any one of three equiangu-
larly spaced angular positions with the three abutments
60 by selective manual operation of the locking slide 70.
The locking slide 70 is frictionally retained in its fully
forward locking position and whereby the case alone can
be held with one hand for making the tape taut. There-
afterg when the reel is manually rotated to reel in the
measuring tape 20, the locking slide 70 is automatically
returned to its fully retracted position.
As will be apparent to persons skilled in the
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art, various modifications, adaptations and variations
of the foregoing specific disclosure can be made without
departing from the teachings of the present invention.
