Note: Descriptions are shown in the official language in which they were submitted.
13i'&N 7.1 ()7
ll\E',E~r. PRI NT]'R
_ _ __~
Backgrollncl of the lnvention
'I`he present invention relates to a label
printer of the type used to print both human
readable and machine readable indicia on labels from
a strip of label stock and, more particularly, to
such a printer in wl~ich the label stock has
laterally extending perforation lines spaced along
its length which define ~he individual labels and in
which the leading label in the strip is printed and
subsequently burst along the perforation line
between it and the next label in the strip.
The printer of the present invention is
particularly suited for weighing and labeling
systems of the type used in supermarkets and grocery
stores for determining the weight and total value of
a random weight packaged item, printing a label
including this information, and applying the label
to the packaged item. Such a label may typically
include machine readable bar code indicia, such as
the Universal Product Code, specifying the type of
product and the total cost of the labeled package,
as well as human readable indicia specifying this
information. Additional information such as weight,
price per unit weight, and shelf life, may also be
printed on the label in human readable indicia.
` Each of a series of packages may be weighed
and labeled automatically, as shown in Treiber
patent No. 3,989,929, issued November 2, 1976, and
assigned to the assignee of the present invention.
The Treiber patent discloses an arrangement by which
a first human readable label is printed by one
printer, and a second bar code label is printed by a
second printer. The labels are then applied in
succession to the top and bottom surfaces of a
package. It will be appreciated, however, that it
Bs:)7
n F&N 7167 -2-
may be desirable to ~abel packages with labels
inclucling both machine readable and human readable
indicia .
Such labels may, for example, be printed on
label stock consisting of a strip of release
material carrying a plurality of labels mounted on
the release material by a pressure sensitive
adhesive. After printing labels of this type, they
may be peeled from the strip of release material and
applied to the packages. Although advantageous in
certain respects, the use of pressure sensitive
adhesive backed label stock is relatively expensive,
and the labels are somewhat difficult to handle
after being removed from the release material.
Additionally, the web of release material takes up a
substantial portion of the label stock supply space
in the printer and, further, must be disposed of in
some manner after the labels are printed and removed.
Other printers, such as shown for example
in U.S. Patent No. 3,104,806, issued September 2~,
1963, to Allen, and assigned to the assignee of the
present invention, have utiliæed a strip of label
stock having a heat activated adhesive coating which
is softened by a heater in the printer output chute
just prior to applying the labels to the packages.
I~eat activated adhesive backed label stock is
advantageous in that no release material is required
to support the labels during printing. Further,
since the adhesive is not activated by heating until
just prior to application of the labels, special
label handling arrangements required with a~hesive
backed labels are unnecessary.
One difficulty, however, in printing on
heat activated adhèsive backed label stock and,
indeed, UpOIl any label stoclc not having a strip oE
backing material, is that printing typically must be
7~)7 -3~-
accomplished on the lat)el at the very forward elld oE
the strip of ]abel stoclc. If it is desired to print
very close to the edge of the label, it may be
difficult to engage the lahel on both sides of the
printing station so as to hold it taut during
printing.
In the printer disclosed in the Allen '806
patent printiny is accomplished both prior to the
detachment of the leading label from the label stock
at a cutting station, and subsequent to the
detachment of the leading label. It will be
appreciated that while the label stock ls not held
on both sides of the print station during printing,
nevertheless, the print quality of the human
readable indicia produced by the Allen printer is
acceptable. Although high resolution printing of
human readable indicia is desirable, it is not
critical so long as the printed indicia are
legible. The resolution of printed machine readable
indicia tends to be somewhat more important,
however, since the printed bars must be well defined
and accurately positioned for reliable readiny by an
optical reader system.
U.S. Patent No. 4,057,015, issued
November 8, 1977, to Kodis, discloses a ticket
printing system having a rotatable print drum with
rows of raised printing elements disposed about its
periphery. A print hammer assembly cooperates with
each column of printing elements or printing
indicia on a paper web advanced between the rotating
drum and the hammer assembly. The web is pressed
against specific printing elements by individual
hammers. The Kodis system prints both bar codes and
human readable indicia and the patent disclosure
recognizes the need for high resolution. The Kodis
printer prlnts both bar codes and human readable
o~
131;~N 7167 ~~~
in(licla on each ticket portion o the web prior to
separa~ion of that portion from the web and with the
leading edge of the~ web bei1lg unsupported. An
attempt is made to improve resolution in the liodis
printer by inking the print drum heavily. While
this may produce bar codes which are of sufficient
contrast, nevertheless, the bars may be slightly
misplaced on the tickets since the tickets are
supported only along their trailing edges during
printing. In reading UPC characters, it is
extremely important to provide accurate spacing
between successive bar characters in order for the
code information to be read successfully by machine.
A further problem which is encountered with
printers of the type shown in the Kodis '015 and
Allen ' gO6 patents is that of separating the
leading label or ticket from the balance of the
label stock or paper web. Quite typically, as shown
in both of these patents, a cutter arrangement is
provided to detach the printed label or ticket from
the unprinted stock or web. Such arrangements add
appreciably to the complexity and cost of the
printers. Additionally, cutting successive labels
from the label stock produces paper dust which may
contaminate various printer elements and require
frequent cleaning.
Accordingly, it is seen that there is a
need for a printing device capable of hlgh
resolution printing of both human readable indicia
and machine readable indicia on the leading label in
a strip of label stock, and for such a device in
which the leading label may be separated from the
strip of label stock subsequent to printing without
unduly complicating the printer.
c~
B];~N 71G7 -5-
_mrl~ar~ o~ the Invetltion
A lak>el printer Lor printin(3 both human
readable and machine readable indicia on the end
label in a strip of perforated label stock, includes
printer means, positioned at a print station, for
printing both human readable and machine readable
indicia on a label transported past the print
station. A supply means provides a strip of label
stock having laterally extending perforation lines
spaced along the strip so as to define a plurality
of labels. Label advancing rollers are provided
between the supply means and the print station for
engaging opposite sides of the label stock and for
advancing the label stock through the print station
to permit printing on the end label thereof. Only
human readable indicia are printed on the end label
during advancement of the end label past the print
station by a predetermined distance. Label
tensioning rollers are positioned on the opposite
side of the print station from the label advancing
rollers for engaging opposite sides of the end label
as the label is transported past the print station.
- The label tensioning rollers are positioned a
distance from the print station equal to or less
than the predetermined distance. As a result, the
label stock is engaged by both the label advancing
rollers and the label tensioning rollers during
printing of the machine readable indicia on the end
label. A roller drive means is connected to both
the label advancing rollers and the label tenisioning
rollers and rotates these rollers in synchronization.
The roller drive means may comprise means
for rotating the label advancing rollers and the
label tensioning rollers at substantially the same
rotational velocity. The radius of the label
tensioning rollers may be greater than the radius of
o~
13~N 7:1C7 -6~
the labe.l advanci.ng .rollers, wher~by the end :Label
i.s held in ten.sioll during printing ol- the maclline
readabl.e indicia.
The printer may further inclucle means
definlng a label output path for removing printed
labels from the printer to a label output, and label
stock bursting rollers, positioned between the label
output and the label tensioning rollers, for
bursting the end label from the strip of label
stock. The bursting rollers may include idler
rollers on one side of the strip of label stock and
noncircular rollers on the other side of the strip
of label stock. The noncircular rollers are mounted
such that a label is is engaged between the idl.er
roll.ers and the noncircular rollers only during a
portion of a rotation of the noncircular rollers.
The label printer further includes a gripping member
positioned adjacent the label output path on one
side thereof and a cooperating roller on the
opposite side of the label output path. The printer
includes means for moving the gripping member to
grip the label adjacent the end label in the central
portion thereof between the member and the
cooperating roller during bursting of the end label
from the strip of label stock.
Accordingly, it is an object of the present
invention to provide a label printer for printing
both human readable and machine readable indicia on
the end label in a strip of perforated label stock
in which label advancing rollers and label
tensioning rollers are provided on opposite sides of
a print station, and in which each label is engaged
by both the label advancing rollers and the label
tensioning rollers prior to printing the machine
readable indici.a thereon; to provide such a printer
in which a roller drive means provides for rotation
~ N 71fi7 -7-
ol` the .label advallcincJ rollers and the label
tensioning rollc-rs at substantia:Lly the same
rotational vel.ocity, but in which the radius of the
label tensioning rollers is greater than the radius
of the label advancing rollers, whereby the end
label is held in tension during printing of the
machine readable indicia thereon; to provide such a
printer in which bursting rollers are also provided
adjacent a label o~tput path for removing printed
labels from the printer to a label output; to
provide such a printer in which the bursting rollers
comprise idler rollers on one side of the strip of
label stock and noncircular rollers on the other
side of the strip of label stock; and to provide
such a printer in which a gripping member is
positioned adjacent the label output path on one
side thereof and a cooperating roller is positioned
on the opposite side of the label output path with
means being provided for moving the gripping member
so as to grip the label adjacent the end label in
the central portion thereof between the member and
the cooperating roller during bursting of the end
label from the strip of label stock.
Other objects and advantages of the
invention will be apparent from the following
description, the accompanying drawings and the
appended claims.
Brlef Description of the Drawings
Fig. 1 is a plan view of a label o:E the
type printed by the printer of the present
invention, bearing both human readable indicia and
machine readable indicia;
: FigO 2 is a plan view, illustrating a
splice between two strips of unprinted label stock;
BL~`hN 7167 -8-
Fig. 3 is a side elevational view of a
printer constructed according to the present
invention;
Fig. 4 is a side view of the drive
mechanism of the printer, as seen from the side
opposite that from which Fig. 3 was taken;
Fig. 5 is an enlarged partial side view,
similar to Fig. 3, showing the label tensioning
rollers of the printer;
Fig. 6 is a view, similar to Fig. 5,
illustrating rotation of the bursting rollers and
movement of the gripping member;
Fig. 7 is a view illustrating the bursting
rollers and gripping member, taken generally along
line 7-7 in Fig. 6;
Fig. 8 is an isometric diagrammatic view,
illustrating the label path;
Fig. 9 is a view of the upper label
advancing rollers, taken generally along line 9-9 in
Fig~ 4; and
Fig. 10 is a sectional view taken generally
along line 10-10 in Fig. 9.
Detailed Descr_ption of the Preferred Embodiment
r~he present invention relates to a label
printer and, more particularly, to a printer of the
type which prints both human readable indicia, such
as alphanumeric characters, and machine readable
indicia, such as a bar code, on labels supplled from
a strip of label stock having laterally extending
perforation lines spaced along the strip so as to
define the labels. Fig. 1 illustrates the leading
label 10 in a strip of label stock 12 after the
label is printed. In contrast, Fig. 2 illustrates a
strip of label stock 12 E~rior to printing and
separation of the labels from the stock along
B~`&N 7167 --9-
perforation lines 1~. It will be notcd that the
strip of lahe~] stock 12 may inclucle a number of
preprinte~d headings which are useful in interpreting
subsequently printed human readable indicia.
The present invention may advantageously be
incorporated into an automatic weighing and labeling
system of the kind utili~ed in grocery stores and
supermarkets to weigh and label produce, meats, and
other items which are packaged in the store. As
shown in the above referenced U.S. patent No.
3,~7~,909, issued April 22, 1975, to Treiber, a
wrapped package may be automatically conveyed to or,
alternatively, manually placed on a scale which
determines the weight of the package. This weight
information is then supplied to a computer which
computes the total price of the package, based upon
previously entered price per unit weight information
The computer then supplies the printer with
control signals specifying the measured weight, the
computed total price, and the unit cost, along with
control signals specifying the name of the packaged
item, the date upon which it was packed, and shelf
life information. Control signals relating to the
product and total price are also provided for
controlling printing of the bar code information on
the label. As shown in Fig. l, the packed "PI~WHEEL
` BROIL STEAK BONELESS" meat weighs l.43 lbs. and, at
a unit cost of ~1.45 per pound, has a total price of
$2.07. The meat was packed on February 24, and the
shelf life is three days. In addition to this human
readable information printed on label l0, bar code
indicia 16 are also printecl on the label. This code
may for example be in the machine readable Universal
Product Code (UPC) format. The printed bar code
identifies the UPC number system selected, the
commodity being sold, the value of the package, and
'7
Bl;~N 71~7 -10-
inc]udes a parity number used by the reading system
to validate the reading operation.
Fig. 3 is a side elevational view of the
label printer with the hinged portion 18 of the
printer cabinet raised to reveal the internal
printer elements. ~ printer means, including a
rotatable print drum 20, is provided for printing
both the human readable indicia and the machine
readable indicia on label stock 12 at print station
22. Print drum 20 is continuously rotated and
defines raised printing elements which are disposed
about its peripheral surface 24 in arcuate columns.
A label to be printed is indexed past print station
22 between the drum 20 and a plurality of print
hammers 25. Each print hammer includes an
electromagnetic actuation device which, when
electrically energized,~ causes the hammer to move
toward drum 20.
The surface 24 of the drum 20 is coated
with ink by means of an ink impregnated roller 26
held against surface 24 by support arms 27 which
engage roller cover 28. Roller 26 may be made of a
porous rubber material which is impregnated with
ink. Ink roller 26 freely rotates in contact with
drum 20 and continuously inks peripheral surface 24
of the drum. When the ink in roller 26 is depleted,
the roller 26 is discarded and replaced by a fresh
roller.
Print hammers 25 are arranged in a row
normal to the plane of Fig. 3~ with each hammer
being associated with a corresponding arcuate
column of print elements on the peripheral surface
2~ of drum 20. An encoder arrangement, such as an
optical encoder, monitors the rotational position of
drum 20 and, when a desired print element in one ot-
the columns Oll surface 24 is properly aligned at
)'7
~ &N -11G7
print .station ~2, the corresponding print hamlller is
electri~ally actuated, and presses the Label against
the inked print e~lement at print station 22,
resulting in printing of the desired indicia on the
label.
The printer further comprises a supply
means, including label supporting rack 29 mounted on
main support wall 30. Rack 29 includes a front
label support flanye 32 and a bottom rack portion 34
which support a an-folded stack 36 of label stock
12. Label stock 12 is folded at every third
perforation line, for example, in a zig-~ag fold
arrangement such that the label stock 12 may be
withdrawn from the top of the stack 36 until the
entire stack is depleted.
If desired, the trailing end of the strip
of label stock making up stack 36 may be connected
to the leading end of a second stack of label stock
by means of a splice 38, as shown in Fig. 2,
attached to the back side of the label stock.
Splice 38 may conveniently comprise a piece of
transparent adhesive backed tape having a
perforation l:ine 39 along its length so as to permit
separation of label 10' from trailing label 10" in
the same manner that the labels within a strip are
separated from the strip of label stock subsequent
to printing. If desired, rear cover portion 40 may
be pivoted reaxwardly to provide an additional
support surface for supporting a second stack o~
label stock which is spliced to the trailing end of
stack 36.
~ s seen in Fig. 3, the label printer
further includes label advancing rollers 42 and 44
which are positioned between the supply means and
the print station 22, and which engage opposite
sides of the label stock 12. When rotated, the
'7
I~.l&N 7:l~,7 -12-
label a~vancillg rollers 42 and 44 aclvance the lahel
stock 1~ through the print station 22 to permit
printing aJ.ong the length of the leading label in
the str.ip. Label 10 on strip 12 is advanced through
the print station 22 in the direction of arr~w 46,
as shown in Fig. 1. During the movement of the
f.irst portion 48 past the print station 22, only
human readable indicia are printed on the end label
10. Only after the label has moved past the print
station 22 by a predetermined distance equal to the
length of portion 48 are the bar code indicia 16
printed. Human readable indicia in the trailing
portion 50 of the label 10 are printed
simultaneously with printing of indicia 16.
Label tensioning rollers 52 and 54 are
positioned on the opposite side of the print station
22 from the label advancing rollers 42 and 44.
Label tensioning rollers 52 and 54 engage the end
label in the strip 12. The label tensioning rollers
52 and 54 are positioned a distance from the print
station equal to or less than the predetermined
distance, corresponding to the length of label
portion 48, and as a consequence, the label 10 is
engaged by the label tensioning rollers during
printing of the machine readable indicia 16 on the
end label. As explained more fully below, the label
tensioning rollers 52 and 54 are rotated such that
their tangential velocity i5 slightly greater than
that of the label advancing rollers 42 and 44. As a
result, the end label 10 is held taut during
printing of the bar code 16 as the second portion 50
of the label 10 is transported past the print
station 22. By holding the label on both sides of
the print station 22 and maintaining the label under
a slight tensi.on, the position of the label with
respect to print station 22 is precisely controlled
t~
J~F&N 7167 -13-
and the bar code indicia printed on the label are
properly positioned and spaced. ~s melltioned
previously, accurately printed indicia greatly
increase the likelihood oE successful machine
reading of the label.
As seen in Fig. 4, the printer includes a
roller drive means including a drive motor 56
coupled directly to shaft 58 upon which label
tensioning rollers 52 are mounted. The label
tensioning rollers 54 are mounted for free rotation
in contact with rollers 52. Motor 56 also is
connected to shaft 60 upon which rollers 42 are
mounted by means of a timing belt 62 extending
between pulleys 64 and 66 and also extending around
idler pulley 68. Motor 56 is preferably a stepping
motor which is actuated to move the labels 10 past
the print station 22 in an incremental fashion, with
each increment of movement being effected after
printing all of the desired indicia on the label at
the portion of the label aligned with the printing
station.
Also illustrated in Fig. 4 is the pulley
drive arrangement by which drum 20 is driven. Belt
70 extends between pulley 72, mounted on drum shaft
74, and motor 76 which is driven continuously at a
substantially constant speed. ~ belt tensioning arm
assembly 78 is mounted on motor 76 and includes a
tensioning roller 80 which is urged into contact
with belt 70 by spring 82 such that the desired
tension is maintained in belt 70.
Pulleys 64 and 66 are substantially the
same in size such that the label advancing rollers
42 and 44 and the label tensioning rollers 52 and 54
are rotated at substan-tially the same rotational
rate. The radius of label tensioning roller 52,
however, is slightly greater than the radius of
sF~N 7]67 -14-
I.abe.l. arlvancing roller 42. The tangential velocity
of rol].er~ 52 and 54 is therefore greater than the
tangential ve]ocity of roll.ers 42 and 44.
Rollers 52 and 5~ are urged togetller with a
force greater than that which urges rollers 42 and
44 toclether. As a result, each label is securely
frictionally engaged between rollers 52 and 5~,
while a small amount of slippage occurs between the
label and roller 42 during printing of label portion
50. Each label is thereby held taut as the machine
readable bar code indicia are printed, resulting in
a higher resolution printing of this portion of the
label and a corresponding increase in machine
readability.
After a label is engaged by rollers 52 and
54, its movement is controlled by these rollers. It
is important to note that these rollers are mounted
on shaft 58 which is directly coupled to driving
motor 56. As a resultr rotation of motor 56 moves
the label by precise increments. Rotational
inaccuracies of rollers 42 produced by the belt
drive do not affect the position o~ the label since
slippage occurs between these rollers and the label
in any event. The tension in the portion of the
strip of label stock between roll.ers 42 and 44, and
rollers 52 and 54 is maintained at a level less than
that which could cause the strip to tear along a
perforation line 14.
After the leading end label in the strip of
label stock is printed, it is necessary to separate
the label from the remainder of the strip of label
stock and to convey i.t along a label ou-tput path.
For this purpose, a pair of continuously rotating
discharge rollers 84 and 86 are provided which
deliver each label 10 to a label output 88. ~ label
retainer 90 is pivotally mounted at 92 and may be
~ ~34~
BY&N 7167 15
moved downward so as to permlt a packacle pressed
agclinst ol~tput 8S to receive a label held within the
retainer 90 and resting on heater 94. Ileater 94
heats each lahel delivered to output 88 so as to
soften heat sensitive adhesive coating on the upper
surface of the label in preparation for application
of the label to a package.
In order to remove the leading end label
from the strip of label stock after the label has
been printed, label stock bursting rollers 96 and 98
are provided and positioned between the label output
88 and the label tensioning rollers 52 and 54. The
label stock bursting rollers 96 and 98 are
illustrated in Figs. 5 and 6 in somewhat greater
detail. Rollers 98 are idler rollers, mounted for
free rotation, which serve to press each label
against rollers 96 during the label bursting
operation. Noncircular rollers 96 are mounted for
rotation on shaft 100 such that a label is engaged
between the bursting rollers only during a portion
of each one-half rotation of rollers 96. Shaft 100
carries a gear 102 which engages an intermediate
gear 104, as shown in Fig. 4. Gear 104, in turn,
engages gear 106 which is mounted on the shaft 108
of clutch 110. Motor 112 continuously drives
discharge rollers 84 and 86 by means of belt 114
extending between pulley 116 on motor shaft 118 and
pulley 120 on discharge roller shaft 122. Clutch
110 is actuated to rotate shaft 100, however, only
when bursting a leading end label from the strip of
label stock is desired.
Gripping member 124 is mounted on shaft 100
which extends through slot 125. Gripping member 124
is positioned below the label output path and a
cooperating roller 126 is mounted above the label
output path. ~ember 124 is movable vertically, as
131~&N /167 -16~
shown in l~ig. 6, such that a ]abel may be gripped
between portion 128 and roller ]26 durincl burstlng
of a ]eading end label from the strip of label
stock. ~ cam 129 is mounted on a shaft 130 which is
rotated by gear 104 during the bursting operation.
Cam 129 contacts a cam follower roller 132 which is
pivotally mounted on arm 134. Arm 134, in turn, is
pivotally supported on shaft 136 and is biased in a
counterclockwise direction, as seen in Figs. 5 and
6, by spring 138 which also engages bar 140. Arm
134 pivotally engages member 124 attached to member
124 at 141. As cam 129 is rotated, the arm 134
pivots about shaft 136. As a consequence, member
124 is raised with respect to shaft 100 by virtue of
lS slot 125 such that portion 129 contacts the bottom
surface of the next following unprinted label and
presses the label against roller 126, as illustrated
in Fig. 7.
The method by which a label is printed and
~0 subsequently burst or detached from the strip of
label stock may be understood more fully by
reference to Fig. 8. The leading label in the strip
of label stock is initially advanced only by label
advancing rollers 42 and 44 which are driven by
stepping motor 56. As the label passes through
print station 22, human readable indicia are printed
on the downwardly facing print receiving surface of
the label. After the label has advanced
sufficiently such that its leading edge is also
engaged by label tensioning rollers 52 and 54 and
the position of the label controlled thereby, the
machine readable indicia are printed on the label,
as well as any additional human readable indicia.
After the label is printed, the strip of
label stock is advanced such that the perforation
line between the leading end label and the next
~F&N 71~;7 -17-
following label in the striE) is positioned between
labe] tensionitlcJ rollers 52 and 54, and label stock
b~lrsting rollers 96 and 98. Prior to positioning of
the perforation line as indicated, the noncircular
rollers 96 are in the position shown in Fig. 5 and,
therefore, the leading label is not pinched between
rollers 96 and 98. When the perforation line is
properly positioned between rollers 52 and 54, and
rollers 96 and 98, rotation of rollers 52 and 54 is
terminatedO Clutch 110 is then actuated to produce
a 180 rotation of rollers 96, pulling the leading
label free of the strip of label stock along the
perforation line.
To enhance this label bursting operation,
the gripping member 124 is moved upward such that
the central portion of the label following the
leading end labe] is held between portion 128 and
roller 126. This ensures that the separation is
complete along the entire row of perforations. The
detached leading label is then conveyed to the label
output 8~ by discharge rollers 8~ and 86 which are
rotated continuously by motor 112.
The 180 rotation of rollers 96 having
been completed, clutch 110 is deenergized, and
portion 128 of gripping member 124 is moved
downwardly out of contact with the label which has
now become the leading end label in the strip of
label stock. Stepping motor 56 is then reversed so
as to rotate rollers 42 and 52 in a clockwise
direction, as viewed in Fig. 3, and retract the
leading edge of the label stoc~ to a point ad~acent
the printing station 22 such that this end label may
now be printed. Determination of the position of
the strip of label stock in the lahel path may
conveniently be made by means of a photocell device
(not shown) positioned adjacent the label path which
B~N 71.67 -18-
detects tlle passage oE ligllt through the openings
144 (l~`igs. 1 and 2) betweell adjacent labels.
As discussed previously, si.nce the
tangential velocity o:E rollers 42 is less than the
S tangential veloc.ity of roll.ers 52, s].ippage occurs
between rollers 42 and a label engaged by both of
these rollers simultaneously. In order to assure
uniform movement of each label through the printing
station 22, the pinching force between rollers 42
and 44 is selected to be less than the pinching
force between rollers 52 and 54, with the result
that substantially all of the slippage occurs
. between the label and rollers 42. Rollers 54 are
mounted on an arm assembly 146 which is pivotally
15 secured to shaft 148. Spring 150 applies a
countercloclcwise movement to arm assembly 146 which
provides the downward force, urging rollers 52 and
54 together.
The support arrangement for upper label
advancing rollers 44 is illustrated in Figs. 9 and
10. Each of rollers 44 is rotatably mounted on an
: arm 154 which, in turn, is pivotally supported on
shaft 156. Arms 15A are engaged by a rod 158 which
extends through support plate 160, acting as a leaf
spring, provides the necessary downward pinching
force between rollers 44 and 42. The radius of
rollers 42 is only slightly smaller than rollers 52,
and as a consequence, very little actual slippage
occurs between rollers 42 and a label. Since the
position of a label during printing of successive
machine readable indicia is controlled by rollers
directly connected to the driving motor, there is no
play in the roller drive, and print position error
for successively printed indicia is minimized.
: 35 It will be appreciated that the label
printer of the present invention has numerous
'7
r~l'&N 71~)7 -]9~
applicat:ions. Whi:le this printer has been descrihed
with respect to :label stock having a heat activated
adhesive coatiny, it will be appreciated that the
printer ma~ be utilized with various other types of
S lahel stock.
While the form of apparatus herein
described constitutes a preferred embodiment oE the
invention, it is to be understood that the invention
is not limited to this precise form of apparatus,
and that changes may be made therein without
departing from the scope of the invention.
What is claimed is:
