Note: Descriptions are shown in the official language in which they were submitted.
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ITW CASE 8016
TENSION RELEASE DELAY MEC~ANISM FOR MANUAL
PNEUMATIC SEAL TYPE STRAPPING TOOL
FIELD OF THE INVENTION
The present invention relates generally to pneumat-
ically operable tools for crimping or applying a metal seal
about the overlapping portions of a tensioned loop of strap-
ping which has been encircled about an object or article to
be strapped for ensuring the integrity of the object or arti-
cle during storage or transportation thereof, and more par-
ticularly, to a pneumatically operable strapping tool whichis provided with a new and improved interlock ~~h~n; sm de-
fined between the tension and seal levers of the strapping
tool so as to ensure the maintenance of a proper tension lev-
el within the strapping during the sealing operation.
~3ACKGROUND OF THE INVENTION
Pneumatically operable tools, for crimping or apply-
ing metal seals about the overlapping portions of a tensioned
loop of strapping which has been encircled about an object or
article to be strapped, are of course well-known in the art.
One early type of conventional pneumatically operable tool of
the aforenoted type is disclosed within United States Patent
3,552,450 which issued to Larry Plunkett and is assigned to
the assignee of the present patent application. Other more
current types of conventional pneumatically operable strap-
ping tools are disclosed within the SIGNODE Operation, Partsand Safety Manual for the PNSC-12/58/34 Push Type Combination
; -. CA 02217063 1997-09-30
Strapping Tool, and within the ORGAPACX Operations Manual
for the CR 25 A Steel Strapping Tool.
As can be readily appreciated from the ORGAPACK
Operations Manual, and as more particularly noted and deR-
cribed on Pages 7 and 8 thereof, the tool comprises a green-
colored tension lever and a yellow-colored seal lever. As is
known, each of these actuating levers operate or control in-
ternal valves which, in turn, operate or control pneumatic-
ally operable motors for operating or actuating the tension
and sealing mechanisms. In utilizing the strapping tool in
order to apply or secure tensioned strapping about an article
or object to be strapped, the strapping is initially drawn
from a supply reel of strapping material, the free end of the
strapping is inserted through the uncrimped seal member, and
the loop of strapping is then encircled about the article or
object to be strapped. After manually tightening the loop of
strapping about the article or object so as to remove a large
portion of slack within the looped strapping, an overlapped
end of the strapping is inserted into the feedwheel -ch~nism
of the strapping tool. The green-colored tension lever is
then actuated so as to actuate one of the internal valves
which, in turn, actuates the air motor operatively associated
with the feedwheel mechanism. The latter tensions the strap-
ping, disposed about the article or object being strapped, to
a predetermined tension level which will be indicated to the
operator as a result of the feedwheel motor drive stalling.
Upon stalling of the feedwheel motor drive, the yellow seal
lever is then actuated so as to similarly actuate the other
one of the internal valves which, in turn, actuates the air
motor operatively associated with the sealing jaw me~h~nism
so as to perform the seal crimping, sealing, and strap cut-
ting operations.
While the aforenoted type of prior art strapping
tools operate quite satisfactorily and have of course been
quite successful in the marketplace, such tools do exhibit
some operational drawbacks or deficiencies which, if properly
~ ' CA 02217063 1997-09-30
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addressed, would provide strapping which is more secure when
such strapp ng is disposed about the objects, loads, articles
or packages~being s~rapped with such strapping. More particu-
larly, the tension and seal levers of such pneumatically ope-
S rated strapping tools are interrelated or re~hAnically inter-
connected with respect to each other by an internal cam mech-
anism. Consequently, when the seal lever is actuated after
the tension or feedwheel motor drive stalls, the depression
of the seal lever, through means of such interrelated or me-
chanically interconnected cam ~echAnism, permits the tensionlever to be released from its actuated position. Accordingly,
actuation of the tension or feedwheel motor drive, through
means of the aforenoted internal pneumatic valving, is termi-
nated. However, due to the fact that the strapping has neces-
lS sarily been subjected to such a high degree of tension by thefeedwheel motor drive in order to properly tension or load
the strapping being disposed about the particular article,
object, or package being strapped, due to the additional fact
that t}.e strapping exhibits a predetermined amount of inher-
ent resiliency, and due to the passage of a predeterminedamount of time, however small, which elapses between the ter-
mination of the tension or feedwheel motor drive and the ac-
tuation and completion of the sealing operation, the tension
level or value achieved by the tension or feedwheel motor
drive at the time of stalling is not able to be maintained
and accordingly the amount of tension within the tensioned
strapping is undesirably reduced to a level which renders the
strapping, disposed about the article, load, or package, to
exhibit a degree of fixation which is not as secure as is de-
sired.
Therefore, there is a need in the art, to which thepresent invention is addressed, for a pneumatically operable
strapping tool wherein the tension level, previously develop-
ed within the strapping during the tensioning phase of the
strapping operation, is able to be fully maintained within
the strapping, at the same tension level and without any re-
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duction in such tension level, during the sealing phase of
the strapping operation even though actuation of the seal
lever has caused the internal cammed interlock mechanism de-
fined between the seal and tension levers to disengage the
tension lever from its actuated and locked position.
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OBJECTS OF THE I~VENTION
Accordingly, it is an object of the present inven-
tion to provide a new and improved pneumatically operable
strapping tool for fastening and securing strapping about ar-
ticles, loads, packages, or the like, in order to securelyfasten or bind the same for storage or transportation pur-
poses.
Another object of the present invention is to pro-
vide a new and improved pneumatically operable strapping
tool, for fastening and securing strapping about articles,
loads, packages, or the like, which does not exhibit the ope-
rational drawbacks or deficiencies of the prior art pneumat-
ically operable strapping tools for fastening and securing
strapping about articles, loads, packages, or the like as has
been noted hereinbefore.
A further object of the present invention is to
provide a new and improved pneumatically operable strapping
tool, for fastening and securing strapping about articles,
loads, packages, or the like, wherein the tension level, pre-
viously developed within the strapping during the tensioningphase of the strapping operation, is able to be fully main-
tained within the strapping, at the same tension level and
without any reduction in such tension level, during the seal-
ing phase of the strapping operation even though actuation of
the tension lever has been disengaged or released from its
actuated and locked position as a result of the actuation of
the seal lever and the operation of the cam mechanism inter-
connecting the seal lever and the tension lever.
CA 022l7063 l997-09-30
SUMMARY OF T~F INV~NTION
The foregoing and other objectives are achieved in
accordance with the present invention through the provision
of a new and improved pneumatically operable strapping tool,
for fastening and securing strapping about articles, loads,
packages, or the like in order to securely fasten or bind the
same for storage or transportation purposes, wherein the seal
lever is provided with an outwardly projecting or transverse-
ly extending tab or tang member which is adapted to extend
over or above the tension lever. Consequently, when the seal
lever is depressed and moved downwardly so as to initiate the
sealing operation, the tab or tang member of the seal lever
will engage an external portion of the tension lever and
thereby maintain the tension lever in its depressed or down-
ward po5ition.
In this manner, despite the internal release ordisengagement of the tension lever from its downwardly ac-
tuated and locked position as a result of the engagement of
an associated tension lever lock lever by means of an intern-
al cam mechanism defined between the seal lever and the ten-
sion lever lock lever, the tension lever is physically main-
tained in its downward depressed position such that the in-
ternal pneumatic or air control valve, operatively associated
therewith for controlling the air motor driving the strap-
tensioning feedwheel ~chAnism, is nevertheless maintainedactivated or open so as to conduct a supply of compressed air
to the air motor driving the feedwheel ?~hani . Therefore,
the feedwheel ~~hanism is maintained active and in its drive
state, and consequently, the predetermined tension level pre-
viously developed within the strapping by the feedwheel mech-
anism during the tensioning phase of the strapping operation
is now able to be fully maintained within the strapping, at
the same tension level and without any reduction in such ten-
sion le~,el, during the sealing phase of the strapping opera-
tion.
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CA 02217063 1997-09-30
~RIEF DESCRIPTION OF THE DRAWING
~ Various other objects, features, and attendant ad-
vantages of the present invention will be more fully appreci-
ated from the following detailed description of the present
invention when considered in conjunction with the accompany-
ing drawing wherein: .~
The SOLE FIGURE is a perspective view of the new
and improved pneumatically operable strapping tool, for fas-
tening and securing strapping about articles, loads, pack-
ages, or the like in order to securely fasten or bind thesame for storage or transportation purposes, constructed in
accordance with the teachings of the present invention and
showing the various cooperative parts thereof.
DETAI~ED DESCRIPTION OF THE PREFERRED EM~ODIMENT
R~ferring r.ow to the drawing, the new and improved
pneumatically operable strapping tool, for fastening and se-
curing strapping about articles, loads, packages, or the like
in order to securely fasten or bind the same for storage or
transportation purposes, is generally indicated by the refe-
rence character 10. The tool 10 conventionally comprises a
feedwheel 12, which is provided for drivably engaging one of
the overlapped ends of the strapping encircled about the ar-
ticle, load, package, or the like to be strapped, and the
feedwheel 12 is adapted to be mounted upon a transversely
extending feedwheel drive shaft 14 which projects laterally
outwardly from a feedwheel gear housing 16. The feedwheel 12
is provided with an axial through-bore 18 which has a hexag-
onal configuration, and feedwheel drive shaft 14 is provided
with a section 20 wherein the external configuration of sec-
tion 20 is hexagonal such that the feedwheel drive shaft 14is drivingly mated with feedwheel 12 as a result of the feed-
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wheel drive shaft section 20 being accommodated within the
hexagonally shaped through-bore 18 of the feedwheel 12. An
air motor 2' has suitable drive components thereof, not
shown, operàtively connected to suitable gear components, not
shown, of the gear housing 16 so as to transmit rotary drive
from the air motor 22 to the feedwheel 12 through means of
the gear housing 16 and feedwheel drive shaft 14.
The strapping tool 10 further comprises a tension
lever 24 which is pivotably mounted upon an upstanding brack-
et 26 by means of a suitable pivot pin 28 such that the ten-
sion lever 24 is pivotably movable between a first, upper,
inoperative or inactive position as illustrated, and a sec-
ond, lower operative or active position, not illustrated, at
which the tension lever 24 actuates a suitable air valve, not
shown, which is fluidically connected to the air motor 22 so
as to permit the drive thereof to be transmitted to the gear
housing 16 and feedwheel 12. An upstanding tension lever lock
lever 30 is pivotably mounted upon the tool 10 such that a
first shoulder portion 32 thereof engages the tension lever
24 when the latter is disposed at its first, upper, inopera-
tive or inactive position, and the tension lever lock lever
30 is also provided with a second shoulder portion, not
shown, which is disposed vertically beneath the first should-
er portion 32 in a spaced arrangement with respect thereto
and which is adapted to engage a notched or recessed portion
34 defined upon the tension lever 24 so as to retain the lat-
ter at its second, lower operative or active position. The
tension lever 24 is normally spring-biased toward its first,
upper, inoperative or inactive position, and tension lever
lock lever 30 may be similarly spring-biased toward its nor-
mal upstAn~ing position so as to properly engage the tension
lever 24 when the latter is disposed at either one of its
first, upper, inoperative/inactive or second, lower, opera-
tive/active positions.
As is also known in the art, the tool 10 further
comprises a seal lever 36 which, in a manner similar to that
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of tension lever 24, is pivotably mounted upon an upstanding
bracket 38 so as to be movable between a first, upper, inope-
rative or inactive position, as illustrated, and a second,
lower, operative or active position, not illustrated, at
which the seal lever 36 activates another suitable air valve,
not shown, which controls the operation of another air motor,
also not shown, for driving the sealing m~h~ni~ of the tool
10 so as to crimpingly secure the metal seal member onto the
overlapped portions of the strapping. As has been noted here-
inbefore, the sealing operation, as initiated by movement ofthe se81 lever 36 from its first, upper, inoperative or in-
active position to its second, lower, operative or active po-
sition, is implemented after a predetermined amount of ten-
sion has been impressed upon the strapping by means of the
lS feedwheel 12 and as indicated to the operator by means of the
stalling of the air motor 22 and feedwheel 12. In addition,
it has also been noted that the seal lever 36 and the tension
lever lock lever 30 are also conventionally ~e~h~n; cally in-
terrelated or interconnected together by means of a suitable
cam ech~n; sm, not shown, whereby when the seal lever 36 is
depressed downwardly so as to be moved from its illustrated
first, upper, inoperative or inactive position to its non-
illustrated second, lower, operative or active position, the
tension lever lock lever 30 is cammed away from its position,
at which it is engaged with the tension lever 24 so as to
maintain the latter at its second, lower, operative or active
position, to a position at which the tension lever 24 is re-
leased and permitted to return from its second, lower, opera-
tive or active position to its first, upper, inoperative or
inactive position.
As a result of such movement of the tension lever
24, activation or operation of the air motor 22 for feedwheel
12 is terminated whereby tensioning of the strapping is stop-
ped. Consequently, during the performance of the sealing ope-
ration by means of the tool's sealing -ch~nism as initiated
or activated by means of the seal lever 36, and its associat-
CA 02217063 1997-09-30
.
ed air drive motor, not shown, and before completion of such
sealing operation, and due to the fact that the strapping had
necessarily been subjected to such a high degree of tension
by the feedwheel 12 in order to properly tension or load the
S strapping being disposed about the particular article, load,
package, or the like being strapped, due further to the addi-
tional fact that the strapping exhibits a predetermined
amount of inherent resiliency, and due to the elapsed time
which elapses between the termination of the feedwheel motor
drive and the completion of the sealing operation, the ten-
sion level or value achieved by the feedwheel motor drive at
the time of stalling of such feedwheel motor drive and initi-
ation of the sealing operation is not able to be maintained
and accordingly the amount of tension within the tensioned
strapping encircled about the particular article, load, pack-
age, or the like being strapped is undesirably reduced to a
level which results in the strapping exhibiting a degree of
fixation which is not as secure as is desired.
In accordance then with the teachings of the pre-
sent invention, the seal lever 36 is provided with an inte-
gral, laterally projecting or transversely extending tab,
tang member, or ear 40 which has its distal free end portion
thereof disposed above the tension lever 24. Consequently,
when the seal lever 36 is depressed and moved pivotably down-
wardly during the initiation of a sealing operation, the arc-
uate movement of the tab or ear 40 will be such that such tab
or ear 40 will encounter and engage an upper surface portion
of the tension lever 24. Therefore, despite the fact that the
aforenoted interconnecting or interlocking cam ~~h~nism de-
fined between the seal lever 36 and the tension lever locklever 30 normally results in the tension lever lock lever 30
being disengaged from its interlocked position or state with
respect to the tension lever 24 so as to permit the tension
lever 24 to be move away from its second, lower, operative or
active position and toward its first, upper, inoperative or
inactive positlon when the seal lever 36 is depressed down-
CA 02217063 1997-09-30
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wardly so as to commence a sealing operation, such downward
depression of the seal lever 30 now results in the integral
tab or ear 40 thereof physically encountering and engaging
the tension lever 24 such that the tension lever 24 cannot
return to its normal or first, upper inoperative or inactive
position. Therefore, the tension lever 24 effectively remains
in its second, lower, operative ~r active position whereby
the tension lever 24 still activates or opens its operatively
associated air control valve, not shown, which permits com-
pressed air to operate air motor 22 which, in turn, and bymeans of the suitable gearing housed within gear housing 16,
drives the strap tensioning feedwheel 12.
As a result of such retention of the tension lever
24 at its second, lower, operative or active position and the
continuance of the drive of feedwheel 12 during the initia-
tion and performance of the sealing operation, the tension,
originally developed within the strapping by means of the
feedwheel 12 during the tensioning phase of the strapping op-
eration, is now able to be fully maintained within the strap-
ping, durin~l the sealing phase of the strapping operation, atthe same tens-on level impressed upon or developed within the
strapping, during the tensioning phase of the strapping ope-
ration, when the air motor 22 driving the feedwheel 12 under-
went stalling because the stall condition attendant the driv-
ing of the feedwheel 12 is effectively maintained. Therefore,the strapping does not experience any slackening or loss of
tension and the strapping can therefore be secured, fastened,
or bound about the particular article, load, package, or the
like with the proper level of tension effectively preserved
therein. Obviously, when the seal lever 36 is released so as
to permit the same to return to its normal, first, upper, in-
operative or inactive position upon the termination of the
sealing operation, the tension lever 24 is likewise permitted
to return to its normal, first, upper, inoperative or inact-
ive position as a result of the disengagement of the seallever tang or ear member 40 therefrom. ~Consequently, it is
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CA 02217063 1997-09-30
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appreciated that the tensioning phase of the strapping opera-
tion is not prematurely terminated, termination of the ten-
sioning pha~e of the strapping operation is effectively de-
layed until after the sealing operation has been completed,
and that the tensioning and sealing operations are terminated
substantially simultaneously.
It is to be further appreciated that the aforenoted
release or disengagement of the tension lever 24 from its
second, lower, operative or active position, as a result of
the camming away of the tension lever lock lever 30 by the
cam rechAnism defined between the seal lever 36 and the ten-
sion lever lock lever 30, cannot be viably prevented by elim-
inating the cam mechanism defined between the seal lever 36
and the tension lever lock lever 30 because the cam ~e~hAn;sm
serves an important operational role within the overall
strapping operation. If such cam mechanism did not exist,
then once the tension lever 24 was depressed and moved to its
second, lower, operative or active position, and when the
seal lever 36 was subsequently moved to its second, lower,
operative or active position so as to initiate the sealing
phase of the strapping opertion, upon termination of the
sealing phase of the strapping operation when the seal lever
36 is released from its second, lower, operative or active
position so as to return to its first, upper, inoperative or
inactive position, the tension lever 24 would nevertheless be
disposed and retained at its second, lower, operative or act-
ive position which would then necessitate manual release or
disengagement of the tension lever 24 from such operative or
active pc~ition. In accordance with the present invention,
such release or disengagement of the tension lever 24 occurs,
in effect, automatically and simultaneously with the release
or movement of the seal lever 36 from its second, lower, ope-
rative or active position to its first, upper, inoperative or
inact1ve position because the tension lever 24 has been pre-
viously released or disengaged from the tension lever locklever 30 as a result of the tension lever lock lever 30 hav-
CA 02217063 1997-09-30
ing be~en moved away or released from its upright illustrated
position by means of the aforenoted cam ~e~h~n;sm~
Thus, it may be seen that the present invention
comprises an advancement in the strapping art to the effect
that by means of the present invention, the deficiencies or
drawbacks characteristic of the prior art or conventional
strapping sealing systems are overcome and the problems re-
sulting therefrom appropriately rectified. In particular, by
means of the present invention, the tensioning phase of the
strapping operation is not prematurely terminated and the
termination of such tensioning phase of the strapping opera-
tion is, in effect, delayed such that the tension level, pre-
viously present within the strapping at the conclusion of the
tensioning phase of the strapping as indicated to the operat-
lS or by means of the stalling of the feedwheel drive motor, isnot reduced. In particular, the tensioning phase of the
strapping operation is positively and effectively continued
until the sealing phase of the strapping operation has been
completed. In this manner, the resultant tension developed
within the 5trapping during the tensioning phase of the
strapping operation is effectively preserved and is therefore
substantially greater than the tension characteristic of con-
ventional strapping secured about articles, loads, packages,
or the like. In addition, such increased resultant tension
level within the strapping facilitates severance of the
strapping when the cutting implement of the strapping tool
severs the sealed strapping from the supply of strapping ma-
terial disposed upon a reel of strapping material upon con-
clusion of the sealing phase of the strapping operation.
Obviously, many modifications and variations of the
present invention are possible in light of the above teach-
ings. It is therefore to be understood that within the scope
of the appended claims, the present invention may be practic-
ed otherwise than as specifically described herein.
