Note: Descriptions are shown in the official language in which they were submitted.
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The present invention yenerally relates to an improved
conveying system, which may be employed for moving packages
through a station at which a package is weighed following by a
station at which a label bearing package weight/price indicia is
applied to the weighed package.
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A problem inherent in weighing-la~eling machines is the
necessity of first moving a package to be weighed from the conveyOr
to a weigher and then returning such package to the conveyor with-
out interrupting conveyor movement or adversely influencing opera-
tion of the weigher or increasing the period of time required by
the weigher to perform a weighing operation. Opposite approaches
to this problem are disclosed for instance by U.S. Patents 2,597,069
and 3,394,792.
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In Patent 2,597,069 transfer of packages from a conveyor
to a weigher and from the weigher to the conveyor is achieved by
projecting elements oE the weigher upwardly between transversely
spaced elements of a continuous bolt type conveyor whereby to lift
the package from the conveyor; the weigher elements being subse-
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;~ quently retracted at the completion of the weighing operation in
order to re-position the weighed package on the conveyor for dis-
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charge from the weighing station. A serious drawback of this type
of machine is that the required vertical displacement of the
weigher produces substantial vibrations, which must of course be
~, dampened before the weighing operation can proceed. As a result
;, 20 only a relatively low speed weighing and labeling operation can be
achieved with this type of machine.
An increase in speed of the weighing operation may be
theoretically achieved by employing a machine of the type disclosed
' in Patent 3,394,792, which features an arrangement wherein a portion
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' of a conveyor passing through a weighing station is lowered and . raised relative to a weighing platform such that vertical deflec-
tions or movement of the platform are essentially limited to those
'~ induced by the weight of the package. However, the operational
speed of this type of machine is limited by the requirement that
the conveyor cannot be driven at a speed above that at which an
article when placed upon the weighing platform will slide off such
platform or be incorrectly positioned thereon. ~1oreover, as the
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~peed of the conveyor and thus the package is increased, the
tendency of the weighing platform to be subjected to tilting
vibrations increases. Since these vibrations must also be dampened
to avoid inaccuracies in the weighing operation, a definite limit
is placed on permissive speed of the conveyor.
The present invention is primarily directed towards an
improved package conveying arrangement, which is particularly
adapted to provide an overall increase in the operational speed
of package weighing and labeling machines cf the general type
described above.
In accordance with a preferred form of the present
invention, a conveyor is formed from a plurality of transversely
spaced, endless belt elements, which are trained about a plurality
of guide or idler rollers to define an intermediate conveyor belt
, flight end connected by non-supporting inlet and outlet belt loop
por~ions to infeed and outfeed conveyor belt flights, respectively.
The intermediate flight extends through the weighing station and
is normally arranged in a package receiving-discharge position
above a relatively stationary weighing platform for receiving a
package to be weighed from the infeed flight and for discharging
a weighed package from the weighing station onto the outfeed flight.
A remotely disposed motor drive is employed to drive the belt.
elements at an essentially constant, given package transport speed.
Certain of the guide rollers adjacent opposite ends of
' the intermediate flight are fixed to a frame having vertical
reciprocating movements controlled by a piston-cam arrangement,
, whose operation is in turn controlled by signals from an electric
eye responsive to the presence of a package to be weighed on the
intermediate flight and to a signal indicating completion of a
weighing operation. The presence of a package to be weighed on
the intermediate flight initiates lowering of the frame associated
guide roller~ and thus the intermediate flight in order to place
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~e package to ~e weighed in res-tin~ en~a~ement with khe weighing
platform, while concurrently shortening and lengthening the out-
feed and infeed belt portions, respectively. Thus, although the
intermediate flight, as an integral part of the overall belt con-
veyor is still driven, its speed relative to the weighing platform
is in effect decreased with the result that the package to be
weighed is decelerated before it is placed in resting engagement ~`
with the weighing platform. When the intermediate flight is ;
returned to its normal package receiving-discharge position for
the purpose of first removing the weighed package from the weighing
platform and then effecting discharge thereof onto the outfeed
flight, the outfeed and infeed belt loops are concurrently length-
ened and shortened, respectively. As a result, the intermediate
flight is caused to accelerate or travel at a speed relative to
the weighing platform, which is in excess of the given package
transport speed.
By employing the intermediate flight to decelerate the
package to be weighed before it is placed in engagement with the
weighing platform, the speed at which packages are presented to
` 20 the weighing station may be substantially increased without sub-
jecting the weighing platform to a corresponding time consuming
increase in vibrational influences or causing misplacement or
; misalignment of the package on the weighing platform. On the other
hand, by causing the intermediate flight to travel at a higher rate
~;, of speed than the overall conveyor speed, as the intermediate ~
flight is ret~rned to its normal position, inertia of the weighed ~-
package may be more easily overcome and it is presented for dis-
1 chaxge onto the outfeed flight within a shorter period of time
i than heretofore possible. As a result, the overall operational
speed of the machine may be substantially increased. Moreover,
the overall conveyor system of the present invention is greatly
simplified, since a single remotely placed motor may be employed
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simultaneously to drive all ~lights of the system. Also, the high
operational speed of the machine permits it to be fed continuously
from a source comprising a lower speed line of engaged end-to end
` packages and automatically to achieve required spacing between
packages for passage through the weighing station, thereby negating
the need to provide escapements or releases to control or permit
intermittent release of packages from the source.
While for the purpose of reference, the conveying system
of the present invention is herein described with particular
reference to its being used in conjunction with a weighing and
labeling machine, it is considered as possessing more general
utility in the field of high speed material handling. Specifically
its use is contemplated in checkweigher apparatus, which would
include a package filling mechanism arranged above a weighing plat-
form. Of course, khe present conveying system would also possess
utility in diverse material handling environments in which a
weighing operation is not involved. As by way of specific example,
the present conveying system may be used wherever it is desired to
bring a conveyed object to rest on a suitable platform in order to
enable some processing step to be performed, including for instance
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inspection, testing treatment and part assembly. With reference
to this latter example, it will be appreciated that it would be
practical to provide a plurality o~ assembling stations or both
, assembling and inspection stations located at spaced points along
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~ a common supporting run of the conveyor system, since the raising
`~ and lowering of the conveyor at any of the stations would not
` influence conveyor speed at adjacent stations.
The nature and mode of operation of the present invention
will now be more fully described in the following detailed descrip-
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tion taken with the accompanying drawings wherein:
Fig. 1 is a perspective view of a machine formed in
- accordance with the preferred form of the present invention;
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Fig. 2 is a sectional view taken generally along the line
2-2 in Fig. l;
Fig. 3 is a sectional view similar to Fig. 2, but showing
a package being weighed;
Fig. 4 is a sectional view taken generally along the line
4-4 in Fig. 2;
Fig. 5 is a sectional view taken generally along the line
5-5 in Fig. 2;
Fig. 6 is a sectional view similar to Fig. 5, but taken -
~10 generally along the line 6-6 in Fig. 3; and
Fig. 7 is a block diagram of the control elements of the
present machine.
Reference is flrst made to Fig. 1, wherein a package
weighing and labeling machine of the present invention is desig-
nated as 10 and shown as generally including a machine base ~2; an
endless conveyor 14, which is supported above the machine base and
~i employed to transport packages 16 lengthwise thereof successively
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i~ through package processing stations including a weighing station
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,~j! 18 and a package labeling station 20; and a control console 22,
~i 20 which is supported by and extends along the front of the machine ,
' base. For purposes of reference, machine base 12 is considered to
:~ include a horizontally disposed top plate 24; a weigher mounting
, standard 26, shown only in Fig. 4; and a pair of brackets 27 and
28, which upstand from opposite ends of the top plate and serve to ~ `
support a conveyor mounting plate 30.
Any suitable means may be employed to feed packages 16
, to and remove same from conveyor 14, as for instance endless belt
1 type supply and discharge conveyors 32 and 33 shown only in Fig.
;;~ 1. The term "package" as used herein is intended to be broadly
construed as including for example a single article, plural `
associated articles, or a container in either an empty or filled
condition.
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It will be understood by referring to Figs. 1, 2 and 4
that weighing station 18 is provided with scale device or weigher
34 including a stationary housing 36, which is fixed to standard
26 by a mounting bracket 38, and a weighing or package processing
platform 40, which is supported by a bar 42 extending horizontally
outwardly through opposite side walls of housing 36 for vertical
movement in response to the positioning thereon of the package to
be weighed. The internal structure of scale device 34 to which
bar 42 is attached may be conventional and forms no part of the
present invention.
In the illustrated form of the invention, platform 40
includes a pair of lower bar or base members 44, which are supported
one by each end of bar 42; a pair of upper bar members 46, which
are ad~ustably supported one on each of lower bar members 44 by
pairs of locking and adjusting screws 48 and 50, xespectively; and ;
, a plurality of parallel, vertically upstanding rib or plate mem-
bers 52, which extend between and are rigidly attached to upper bar ~i
¦ members 46 and have coplanar upper edge surfaces 52a, which serve
j to support packages 16 during a weighing operation. The construc-
tion of platform 40 may depart from that illustrated in the drawings
as required to handle packages of varying shape and/or size.
Weighing station 18 would also include an electric eye or
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; other suitable sensor device 54 for sensing the presence of a
3~ package presented to the weighing station. Sensor device 54 would
normally be arranged within the confines of the weighing station
to indicate the proper positioning of a package by conveyor 14 over
~, platform 40.
;~ Labeling station 20 is shown for purposes of illustration
, as including a suitable label supply 56, a label printer 57 and
label-applicator 58, which may be conveniently mounted on a pedestal
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60 upstanding from the rear of top plate 24. The specific construc-
tion of the labeling station forms no part of the present invention.
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A suitable computer designated generally as 62 in Fig.
7 and conveniently enclosed wi-thin console 22, is responsive to
scale device 34 for controlling operation of labeling station 20
such that a label will be printed with any of the following:
~: weight, price of a weighed package, and the price per pound; and
such label immediately applied to the weighed package as it is
passed through the labeling station. To insure weighing accuracy,
` the unladen or tare weight of platform 40 would be sensed before
each weighing o~eration and the thus newly established tare gross
weight employed in computing the weight of the next package to
be weighed. Computer entries of package tare weight, net weight,
price per pound and package price may be presented for observation,
as digital displays 64. The specific construction of computer 62
and the elements of labeling station may be conventional and form
', no part of the present invention.
, Now referring to Figs. 1-4, it will be seen that conveyor
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14 is in the form of an endless belt type conveyor including a
plurality of transversely spaced, endless belt elements 70, which
are preferably in the form of endless chain elements, trained about
~ 20 a plurality of peripherally grooved guide or idler rollers 71-80 ; -~
-' and a drive sprocket or roller 81 to define relatively aligned,
package supporting infeed, intermediate and outfeed conveyor belt
flights or conveyor portions 82, 84 and 86, respectively; non-
; package supporting infeed and outfeed conveyor belt loops or con-
', veyor portions 88 and 90, which serve to connect the infeed and
;7 outfeed ends of intermediate flight 84 with infeed and outfeed
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flights 82 and 86, respectively; and a non-package supporting
return or drive conveyor portion flight 92. As will be apparent
from viewing Fig. 2, intermediate flight 84 is arranged to extend
,; 30 through weighing station 18, whereas outfeed flight 86 is arranged -
~, to extend below labeling station 20.
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Conveyor belt elements 70 are normally simultaneously
driven at an essentially constant, given package transport speed
by sprocket 81, which is in turn connected to a suitable source
of power including a chain or belt drive 94 and an electrical motor
not shown; tension in the conveyor belt elements being adjustably
controlled, as required, by a suitable spring bias applied for
example to guide roller 71. ~;
In the illustrated construction, mounting plate 30
serves to cantilever support rollers 71-73 and 77-80, as well as
sprocket 81, such that infeed and outfeed flights 82 and 86 are
vertically fixed in horizontal alignment and disposed relatively
above weighing platform 40. Elongated, generally U-shaped channel
elements 96 and 98 may be also suitably supported by mounting plate
30 for the purpose of guiding and preventing undesired gravity and
package weight induced vertical flexures of the belt elementSof
~infeed and outfeed flights 82 and 86, respectively.
Rollers 74, 75 and 76 are end journaled on a frame 100,
which is supported by pairs of guide rods 102 and 104 for vertical
- reciprocating movements relative to platform 40, whereby to move
-~ 20 intermediate flight 84 vertically between an upper package
receiving-discharge or transport position shown in Figs. 2, 4 and
5, and a lower weighing position shown in Figs. 3 and 6. Vertical
'`'! movements of frame 100 are under the control of a pneumatically
operated control mechanism 106, which in turn is controlled by
computer 62 in response to a package present signal generated by
sensor device 54 and a package weighing operation completion sig-
nal generated by scale device 34.
Referring to Figs. 2 and 4, it will be understood that
guide rods 102 and 104 slideably extend through vertically aligned
guide openings, not shown, provided in mounting plate supported
brackets 106a, 106b and 108a, 108b, respectively. Any suitable
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: means, such as coil spring devices 110 and 112 disposed about rods
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102 and 104 to end bear on brackets 106b and 108b and rod carried
plates 114 and 116, respectively, may be employed to assist gravity
in tending to drive frame 100 downwardly from its upper or trans~
port position into its lower or weighing position, shown in Figs. 2
and 3, respectively. The lower ends of each pair of guide rods
102 and 104 are interconnected by pin shafts 118 and 120, respec-
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tively, which serve to journal follower rollers 122 and 124,
respectively. `~
Again referring to Figs. 2 and 4, it will be seen that
frame 100 includes generally U-shaped infeed and outfeed loop
`~ brackets 128 and 130, which are rigidly connected to the upper
ends of guide rods 102 and 104, respectively and serve to end ~1
journal rollers 74, 75 and rollers 76, respectively Brackets
128 and 130 are rigidly interconnected by elongated, generally
U-shaped channel members 132, which additionally serve to guide
and prevent undesired gravity and package weight induced flexures
of belt elements 70 of intermediate flight 84 intermediate rollers
75 and 76.
Control mechanism 106 includes a pneumatic cylinder
device 140 having a casing 142 rigidly fixed to a guide support
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~i plate 144, which is in turn cantilever supported by mounting ; ;~
plate 30. The piston rods 146a and 146b of cylinder device 140
are connected to like shaped and orientated cam blocks 148a and
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`~ 148b. Cam blocks 148a and 148b are slideably supported on the
upper surface of plate 144 and have their upper or cam surfaces
positioned to provide continuous support for roller devices 122 ~ ~
~, and 124, respectively. The upper surfaces of guide blocks 148a ` ;~;and 148b include essentially horizontally disposed or first cam
`~ portions 148a' and 148b' and vertically inclined or second cam
30portions 148" and 148b". Means other than a pneumatic cylinder
and cam arrangement may be employed to control ver~ical movements
~ of frame 100 in the manner to be described.
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In the package transport condition of cylinder device
140 illustrated in Fig. 2, wherein piston rod 146b is fully ex-
tended and piston rod 136a is fully retracted, rollers 122 and
124 are disposed in engagement with horizontal cam portions 148a'
and 148b', respectively; this serving to maintain frame 100 in
its upper transport or non-processing position shown in Fig. 2
against the effects of gravity and the bias of springs 110 and
- 112. In this position of frame 100, conveyor elements 70 of
intermediate flight 84 are arranged in essential horizontal
alignment with the belt elements of infeed and outfeed flights 82
and 84, as best shown in Fig. 2, and are disposed vertically
above the upper surfaces 52a of platform plate members 52, as
best shown in Fig. 5, such that a package 16 may be fed into or
discharged from weighing station 18 free from engagement with
weighing platform 40. In the package weighing condition of
; c~linder device 140 illustrated in Fig. 4, wherein piston rod
146a is fully extended and piston rod 146b is fully retracted,
rollers 122 and 124 are disposed in engagement with inclined cam
, portions 148a" and 148b"; the movement of the rollers downwardly
along these inclined cam portions permitting lowering of frame
100 into its lower weighing or processing position. As frame 100
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moves into its lower position, belt elements 70 of intermediate
flight 84 are lowered into their weighing or processing position
below surfaces 52a of platform 1ight members 52 and as this occurs
a package to be weighed is lowered into supporting or resting
engagement with surfaces 52a to initiate the package weighing
operation.
By again referring to Figs. 2 and 3, it will be under-
stood that as frame 100 is lowered, the length of infeed loop 88.
as measured between rollers 73 and 74 is increased as the length
` of autfeed loop 90, as measured between rollers 76 and 77, is
correspondingly decreased. This concurrent lengthening and
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shortening of the infeed and outfeed belt loop portions serves to
decelerate or reduce the speed of intermediate belt flight 84
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relative to both frame 100 and scale platform 40 to a value less
than the given conveyor transport speed. The rate at which the -
intermediate bolt flight and thus a package carried -thereby is
decelerated relative to platform 40 will be proportional to the
rate of fall or downward movement of frame 100, this in turn
being determined by the speed of operation of control mechanism
~06.
-, 10As intermediate flight ~4 reaches its weighing position
,after depositing the package to be weighed on platform 40, change
in length of the infeed and outfeed loops ceases to occur, and
thus the speed of the intermediate flight relative to platform 40
returns to its initial or given transport speed.
After a weighing operation has been completed, cylinder
~, device 140 is returned to its initial or package transport condition ~ `~
3 described above. As this occurs the belt elements of intermediate
conveyor 84 initially lift the weighed package from platform 40 and
finally return same to its initial or infeed elevation for dis-
charge onto outfeed flight 86. It is important to note that as
frame 100 is raised, the length of infeed loop 88 is decreased as
the length of outfeed loop 90 is correspondingly increased. This
concurrent shortening and lengthening of the infeed and outfeed
, loops serves to accelerate or increase the speed of intermediate
belt flight 84 relative to both frame 100 and scale platform 40 to
a value in excess of the given transport speed. The rate of change
in speed is proportional to the rate of rise of frame 100, which in
turn is datermined by the speed of operation of control mechanism
106. As intermediate flight 84 reaches its initial or receiving-
j 30 discharge position, the change in length of the infeed and outfeed
loops ceases to occur, and thus the speed of the intermediate flight
relative to platform 40 returns to its initial or given transport
` speed.
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By employiny intermediate flight 84 to decelerate the
package to be weighed before it is placed in supportlng or resting
engagement with weighing plat~orm 40, the speed at which packages
; are presented to weighing station 18 may be substantially increased
' without subjecting the weighing platform to a corresponding time
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consuming increase in vibrational influences or causing mtsplace-
ment or misalignment of the package on the weighing platform. On
the other hand, by causing intermediate flight 40 to travel rela-
~ tive to the weighing platform and thus the stationary weighed
'~ 10 package at a higher rate of speed than the overall conveyor speed,
as the intermediate flight is returned to its receiving-discharge
position, inertia of the weighed package may be more easily over-
come and it is presented for discharge onto outfeed flight 86
;~ within a shorter period of time than would otherwise be possible.
The construction of the conveyor system of the preferred
form of the present invention is relatively simple, since a single
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endless conveyor defines all of the package supporting flights and
a sLngle remotely placed power source may be employed simultaneously
, to drive all such flights at a constant speed.
Further, it will be understood that the relatively high
transport speed of conveyor 14 permits required spacing of packages
passing through machine 10 to be achieved without the use of an
' escapement for controlling discharge of such packages from a source
s. o end-to-end or abutting packages, such as would be provided by
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supply conveyor 32 having a relatively lower transport speed. For
the specific form of the invention disclosed, differences between
s transport speeds of conveyor 14 and supply conveyor 32 will be on
I the order of between 2 and 2 l/2 to l.
j While the specifically disclosed form of conveyor 14 is
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l 30 preferred from the standpoint of simplicity of machine construction
i and control, it is anticipated that the basic concept of employing
-~ a vertically displaceable, variable speed conveyor section in the
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~eighing station initially to dec~ease the speed of a package to
be weighed prior to its engagement with a weighing platform and
subsequently to assist in overcoming the inertia of a stationary
~eighed package, may be employed in other weighing machines. As
by way of example, it is contemplated that one or both of infeed
flight 82 and outfeed flight 86 may be replaced by other conveyor
devices, including chutes, which are separate from the intermediate
and drive flights and loop portions of the conveyor.
As previously indicated, it is also contemplated that the
described conveyor system possesses utility in association with
mechanisms other than weighing and labeling machines. Specifically,
the present conveyor system possesses utility in any environment
requiring a package, article or the like to be brought to rest on a
platform, fixture or the like at one or more processing stations
arranged along a high speed conveyor run without changing the speed
at which the conveyor is driven. In view of the general utility of
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the present conveyor system, the genoric term "processing" is used i;~
in the appe~nded claims to include any operation or process performed
on a package, article or other object incident to its being brought ~ s~
to rest on a platform by operation of the present conveyor system
including as by way of example, weighing, inspection, testing,
treatment and part assembly.
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