Thermal ink transfer decorating apparatus

In a thermal ink transfer machine, the web is drawn translationally through a station at which thermal ink graphics are transferred from the web to the periphery of a container such as a glass or plastic bottle or can. Transfer of the graphics is effected with a transfer head or cylinder which has arranged about its axis of rotation a plurality of equally spaced apart radially spring biased rollers. When the longitudinally extending graphics on the web enters the transfer station, the spring biased rollers yield radially inwardly and outwardly to press against the backside of the web to effect transfer of the graphics. The apparatus has the rotating transfer head on one side of the web and the containers carried on a turntable on the opposite side of the web. The transfer head rotates in a particular direction around its vertical axis and drives the rollers orbitally toward and away from the graphics transfer station. The containers are supported on rotationally driven disks that are equally spaced apart on the turntable and bring the periphery of the containers into alignment with one of the spring biased rollers when graphics transfer is initiated where the leading end of the graphics make first contact with the container. The containers rotate in a direction opposite from the direction in which the turntable rotates. Thus the periphery of a container when in the transfer station moves in the same direction as the web. Means are provided for feeding web from an unwind reel to the transfer station and from the transfer station to a rewind reel. Means are also provided for maintaining equality in the length of web extending from the unwind reel to the transfer station and from the transfer station to the rewind reel. Means are also provided for maintaining constant tension in the web.

BACKGROUND OF THE INVENTION 
The invention disclosed herein pertains to a machine for transferring 
graphical and decorative images from a moving web to moving articles such 
as containers including plastic and glass bottles and metal cans. 
Machines for transferring graphics and decorative images printed in the 
negative or reverse form on a web with heat transferable ink are basically 
known. The ink images on the web, whether for decorating a container or 
for providing graphical information will be characterized herein 
selectively as "graphics". The transfer process will be characterized as 
"decorating" for the sake of brevity. For optimized graphics transfer of 
an image from the web to a container it is usually necessary to heat the 
container and the web before the web is pressed against the container to 
transfer the graphics at a transfer station. The web is coated with a 
release agent which assures that no trace of the ink will remain on the 
web after thermal transfer. 
Containers that are to be decorated are conveyed linearly uniformly spaced 
apart and rotated about their own axes as they pass the transfer station 
and are transported on a turntable so the containers arrive at the 
transfer station in phase with graphics on the web. 
Existing thermal ink graphics transfer machines have been found to be 
disadvantageous because they must be run at unacceptably low speeds in 
order to obtain reasonably accurate positioning and appearance of the 
decoration on the containers. These machines are not suitable for use in a 
production line with other apparatus that may process containers that are 
fed to the thermal transferring machine at rates of five or more times the 
rate at which the existing machines can be operated. Precise positioning 
of graphics on a bottle or can is especially important where a graphics 
label or decoration is to be applied to the front of bottles or cans and 
other decorations are to be applied to the backs of the bottles or cans. 
In such cases the decoration or labeling on the front and back of the 
container must be diametrically opposite of each other. For prior thermal 
ink transfer decorating machines to be widely acceptable it would be 
necessary for the machines to decorate containers at speeds of five 
hundred containers or more per minute. Insofar as applicant is able to 
ascertain, speeds of this magnitude have never been achieved before the 
invention to be described herein was made. 
It is elementary that any thermal ink graphics transferring machine must 
unwind a roll of web bearing uniformly spaced apart graphics. Various 
satisfactory wind and unwind systems are available since they have been 
used for a long time in other labeling machines. The technology for 
maintaining proper web feed rates and tension is also known. Designers of 
web handling or transporting apparatus have been reasonably successful in 
achieving low inertia web handling systems so the web can be accelerated 
and decelerated rapidly to correct for positional errors between the 
graphics and place where the moving web and graphics ought to be relative 
to each other when graphics transfer occurs. If the inertia within the web 
handling system is high, there is an increased probability of the web 
being stretched or broken when it is being accelerated. 
One of the reasons why the output of decorated containers from existing 
graphics transfer machines has been less than optimum results from 
designers failing, before the invention disclosed herein was made, to 
realize or understand what the relationship should be between the speed 
and direction of the web, the rotational speed and rotational direction of 
the container and the translational direction of the container. 
SUMMARY OF THE INVENTION 
In the machine described herein, articles including containers such as 
plastic and glass bottles and cans are transferred in succession and in 
upright orientation to support disks that are continuously rotating and 
are arranged in a circle about a turntable. Coincident with arrival of a 
container on a support disk, a "centering bell" for each container is 
driven downwardly to engage the top of the container and stabilize it. 
Shortly thereafter, the support disk starts to rotate at a substantial 
speed about its vertical axis. The turntable is turning about its vertical 
axis and the container is turning about its vertical axis as the container 
is being translated in a circular path by the turntable. A rotatable 
thermal ink graphics transfer head is arranged along the circular path 
with its periphery proximate to the peripheries of the passing containers 
with the web interposed or being translated between the head and the 
containers. The rotational axis of the transfer head is parallel to the 
rotational axis of the turntable when the graphics are transferred to a 
regular upright cylindrical region of a container. The transfer head has 
radially biased equiangularily spaced apart rollers at its periphery. The 
web translates in contact with the periphery of the container and the web 
moves between the transfer head and the periphery so the rollers on the 
transfer head press against the bare back face of the web and roll the 
thermal ink graphics onto the rotating container. 
According to the invention, the theoretical and actual maximum output of a 
thermal ink graphics transfer machine is obtained by having the transfer 
head on one side of the web and the turntable on the other side of the web 
such that their linear or tangential components of rotation point in the 
same direction and the transfer head and turntable rotate about vertical 
axes in opposite directions. The web is translated in either direction of 
the tangential components of the rotating head and the turntable. The 
containers on the turntable are on individual rotatingly driven disk 
supports for the peripheries of the containers to move in the same 
direction as the web translates but in either direction of the rotational 
direction of the turntable. Stated in another way, the containers rotate 
in a direction opposite of the direction in which the containers travel or 
translate and the web translates in the peripheral direction of the 
container. 
For the most part, the machine uses conventional parts and methods for 
maintaining equality in the tension and quantity of web leading from the 
web unwind reel to the graphics transfer station and from the transfer 
station to the bare web rewind roll. Web equality is accomplished by 
utilizing a shuttle in conjunction with metering rolls. The shuttle 
signals a programmable controller when inequality exists and the 
controller controls the metering rolls to run at a rate that reestablishes 
equality. 
A photodetector senses registration marks on the web in a traditional way. 
The marks are indicative of the location on the web of the leading edge of 
the graphics. Any error between where the graphics are located relative to 
the machine or container position is corrected quickly with a capstan 
motor that drives rollers that pinch the web near the transfer station and 
either accelerate or decelerate the web to assure that the leading end of 
the graphics will first touch the container exactly on the container where 
graphics transfer should begin. 
How the rotational directions of the turntable, the containers, the 
transfer head, the direction of the linear components of rotation, and the 
direction of web travel relative to the transfer edge, turntable and 
containers are implemented will be evident in the more detailed 
description of a preferred embodiment of the invention which will now be 
set forth in reference to the accompanying drawings.

DESCRIPTION OF A PREFERRED EMBODIMENT 
The general characteristics of the thermal ink transfer machine will be 
outlined in reference to FIG. 1. The machine is comprised of a base 10. 
Operator interface with the machine is accomplished with a computer 
station 11 which is symbolized by a rectangle and includes a programmable 
logic controller (PLC). A turntable, generally designated by the numeral 
12, is driven rotationally about a vertical axis on a shaft 13. The 
turntable 12 has a circular rim 14 on which are mounted for rotation about 
their vertical axes a plurality of container support disks 15 which are 
spaced apart equiangularily on rim 14. By way of example and not 
limitation, there are forty rotationally driven disks in the illustrated 
machine. As will be explained in more detail later, each disk 15 receives 
a container such as 17, such as a plastic or glass bottle or metal can, 
that is fed into the machine for being decorated by the thermal ink 
transfer method. Also to be discussed in more detail later is how a 
centering bell, not shown in FIG. 1, comes down on the open mouth of a 
container 17, such as a bottle or can or any other suitable article, to 
stabilize the container as it is rotated about its vertical axis by 
rotating container support disk 15 while the container 17 is being 
translated reversely by turntable 12. 
Containers that are to be decorated or labeled, as the case may be, are 
supplied to the machine by an infeed belt conveyor 18 on which the 
containers 17 have little, if any, space between them. A deflector 19 
directs incoming containers 17 from infeed conveyor 18 to another conveyor 
20 which is translating slower than conveyor 18 so the containers become 
back-to-back on conveyor 20. This is conventional. The pitch of the infeed 
worm 21 is the same as the pitch of the pockets 23 in an infeed starwheel 
22 which is driven for rotating about a vertical axis at a constant speed 
in phase relationship with turntable 12. As containers 17 are moving along 
on conveyor 20, they are captured by the infeed worm 21 and advanced into 
pockets 23 of infeed starwheel 22. The starwheel moves the containers and 
deposits them successively and correctly synchronized on rotatable 
container support disks 15 that orbit with turntable 12. When an incoming 
container 17 is released from infeed starwheel 22 to the turntable 12, the 
container is engaged at its mouth end by a centering bell, not shown in 
FIG. 1, for the container to be ready for being rotated as it orbits. 
After the containers 17 on the turntable 12 are decorated, at one or more 
of the decorating stations in units 25, 26 and 27, the containers are 
transferred consecutively from turntable 12 to an outfeed starwheel 28. 
The starwheel 28 discharges the decorated containers to linear outfeed 
conveyors 29 and 30 in the stated order. 
Substantially all of the structure thus far described except the briefly 
mentioned decorating units, 25, 26 and 27 is conventional. 
The center-to-center or axis-to-axis distance between adjacent rotating 
container support disks 15 and the containers thereon is characterized as 
the "machine pitch". An encoder, not shown, makes one revolution per 
machine pitch. Counting means in the programmable controller count 
continuously at the rate of 1,000 counts per machine pitch, for example. 
The beginning of a 1,000 count series is marked by the encoder signaling 
the machine position. Thus, in a sense, the programmable controller knows 
where the machine is at all times to within one part in 1,000 so that the 
leading edge of the graphics on the web can be made to make first contact 
with the container very accurately in respect to the place on the 
container where the graphics deposition should be started. The rate at 
which the bottle rotates depends upon a number of factors including 
machine pitch relative to the diameter of the container. By way of example 
and not limitation, in an actual embodiment of the machine, beverage 
bottles, for example, are rotated at approximately two revolutions per 
pitch as they are transported by the turntable and as they are being 
decorated. 
In FIG. 1, one may see that each one of the decorating units 25, 26, and 27 
has affiliated with it web unwind and rewind systems 31, 32 and 33. These 
systems are well known but will be discussed in a little more detail 
later. 
Part of the drive system for the rotatable container support disks 15 on 
turntable 12 is shown in the plan view of FIG. 2. At a level slightly 
below the turntable 12 the latter is surrounded over the majority of its 
circumference by a stationary toothed belt 35. One end 36 of the belt is 
anchored in a belt anchoring and tensioning mechanism 37 and the other end 
is fastened in a belt anchoring mechanism 38. The smaller circles 56 in 
FIG. 2 are the circular tops of bearing capsules which appear in side 
elevation in FIGS. 6 and 7, for example. Skilled designers will perceive 
that the toothed belt 35 can be anchored and tensioned in various ways so 
that elaboration of this matter is not necessary. It is sufficient to 
observe that the gears 39 are rotated by engaging the belt and that the 
containers rotate on support disks 15 at the rate of gears 39 while the 
containers are translated by the turntable 12. 
As shown in FIGS. 2, 6, and 7, the teeth of belt 35 mesh with toothed 
wheels 39 which rotate freely on shaft 42. A bearing 41 on rotatable shaft 
42 permits gear 39 to rotate on it. A gear 43 is pinned to wheel 39 for 
the two to rotate together freely on shaft 42. Gear 43 has a bearing 44 
fitted on shaft 42. Gear 43 meshes with a pinion 45 which is keyed to a 
rotatable shaft 46. Another gear 47 is keyed to rotatable shaft 46 and 
meshes with a pinion 48 that is keyed to shaft 42 for rotating shaft 42 
and, hence, rotating container support disk 15 which is fastened to shaft 
42 with a machine screw 50. Shaft 42 is mounted for rotation with two 
bearings which are fixed in a cylindrical member 53 and are fixed in 
turntable 12. Shaft 46 is rotatable by means of two bearings 54 and 55 
whose outer races are fixed in cylindrical member 56 whose top circular 
surface shows in FIG. 2. In FIGS. 6 and 7, a container in the form of a 
bottle 17 is rotating with container support disk 15. Part of a front 
thermal transfer label that is presently being applied to container 17 is 
outlined with dash-dot lines. 
The gear train just described is for stepping up the rotational speed of 
the support disks and containers thereon about their vertical axes 
relative to the turntable rotational speed. Because of the relationship 
mentioned earlier between the rotational and translational directions of 
the turntable, transfer head, bottle supports and web, unusually high 
rotational speeds for the disks and bottles can be used to maximize 
productivity of the machine. 
FIG. 6 also shows the working part of a container centering and stabilizing 
assembly designated generally by the numeral 61. The assembly and its 
function are well known to designers of labeling machines and the like. A 
container 17 rotating at high speed and orbiting at the same time with the 
turntable must be prevented from falling off its support disk 15. Thus, 
when a container is being released by infeed starwheel 22 to a container 
support disk 15 on turntable 12, a conventional cam activated spring 
loaded cylinder 66 drives a ram 62 downwardly. The ram has a stem 63 to 
which a coupler, usually called a centering bell 64, is attached. The 
lower end 65 of the centering bell is configured for engaging a mouth of a 
container 17. The ram 62 is journaled for rotation in cylinder 66. 
FIG. 6 also shows a side elevational view of a typical one of the thermal 
ink transfer heads or cylinders which will be returned to for discussion 
later. One may observe at this time that the axis of the transfer head is 
vertical in FIG. 6 which is appropriate for transferring thermal ink 
graphics from a web 95 to the front or diametrically oppositely to the 
back of the cylindrical body of a container such as a bottle. In FIG. 7, 
on the other hand, the transfer head is tilted to provide for applying 
graphics to a tapered surface of revolution such as the neck of a bottle 
17. FIG. 3 shows a general or summary arrangement of some parts of the 
machine involved in orbiting and concurrently rotating containers. Most of 
the parts are conventional except for the two of three transfer heads 70 
and 72 which are illustrated. The mechanisms 72 and 74, for raising and 
lowering the transfer heads to permit decorating containers of various 
heights and for moving the transfer heads radially inwardly and outwardly 
to permit decorating containers of various diameters, has also been used 
in labeling machines before. FIG. 3 shows that the turntable 12 is driven 
rotationally by a driven shaft 75 that is coupled to the main drive 
system, not shown, of the machine. The shaft is provided with bearings 76 
and 77 for rotating in a housing 78. The typical transfer heads 70 and 71 
are driven by shafts which interconnect with upper and lower universal 
joints 79 and 80. Typical universal joint 80 is in a housing 81 which is 
mounted to a gear 82 for rotating with the gear. Gear 82 is driven by a 
gear 83 which turns with shaft 75. The toothed wheels 39 that are driven 
by running along stationary toothed belt 35 are also shown. The structure 
85 which supports the pressurized air lines and so forth for actuating 
centering bell assemblies 61 can be raised and lowered to adjust for 
containers 17 of various heights. When shaft 75 is driven rotationally 
about its vertical axis, the container supports 15 rotate and orbit 
concentrically on the turntable 12 around shaft 75. This shaft is actually 
hollow for bringing up tubing and wiring, not shown, as is a known 
practice. A bellows cuff 86 is concentric with shaft 75 to keep the shaft 
unexposed for any elevation of structure 85. 
Attention is now invited to FIG. 8 to initiate a more detailed description 
of the new thermal ink graphic transfer unit and the web control system it 
incorporates. Any unit 25, 26 or 27 depicted in FIG. 1 could be selected 
for description because they are all the same structurally. In FIG. 8, the 
unit is identified as unit 25. This unit has web unwind and rewind system 
31 associated with it and contains unwind and rewind rolls 91 and 92 which 
are more easily visualized in FIG. 9 and will be discussed briefly later. 
The spindles for the rolls are congruent in FIG. 8 so only one spindle 93 
appears but the other spindle 94 is beneath it. 
In FIG. 8, a web 93 being unwound from an unwind reel through a dancer roll 
system is moving in the direction of the arrow 96. The graphics, not 
visible, which are represented with thermally transferable ink are on the 
side of the web where the lead line from numeral 95 touches the web. It is 
this side that will ultimately bear on the periphery of a container 15 in 
the ink transfer station 9. The web may be comprised of a paper-like 
substrate which has a release coating on it that is compatible with the 
ink graphics which are printed in negative or reverse form on the release 
coating and are transferable to an object such as a glass, plastic or 
metal container when subjected to heat and pressure. A suitable web 
material is obtainable from Avery Dennison Manufacturing Company of 
Framingham, Mass. as well as other manufacturers. It is necessary for the 
container to be hot, usually over 175.degree. C. (350.degree. F.) to get 
satisfactory transfer. The container preheating oven is not shown nor is 
the heat curing oven through which the containers pass after they have 
been decorated to cure the ink. After curing, the ink adheres tenaciously 
to the containers. It is estimated that despite expected rough handling of 
returned containers by consumers and others, that the graphics will 
withstand multiple recycles without significant blemishes. 
All of the same type of graphics on any web 95 are ideally uniformly spaced 
apart or, in other words, the graphics have uniform pitch. The rotational 
speed of a container depends on the length and pitch of the graphics on 
the web. There are registration marks 211, not visible on the web except 
in FIG. 4, that are ideally uniformly spaced apart and are ideally at a 
uniform distance from the graphics. Errors must be compensated to assure 
that the graphics make first contact on the container the graphics to be 
rolled on at exactly the same place on every container passing through the 
machine. How this is accomplished will be explained in more detail later. 
In FIG. 8, the web 95 after unwinding from unwind reel 91 first encounters 
a direction changing idler pulley 97. A twist is imparted by roll 97 since 
the web comes off of the unwind reel running horizontally and must go 
through the machine with the plane of the web oriented vertically. Shortly 
after roll 97, the web passes between a pair of pinch rolls 98 and 99 
which are motor driven web infeed metering rolls. These rolls participate 
in maintaining equality or balance in the quantity and tension of the web 
on the infeed unwind side of the thermal ink graphic transfer head 70 and 
station 9 and on the outfeed or web rewind side of the transfer head and 
station 9. The rolls 98 and 99 also function to limit inertia in the web 
transport system. Inertia must be minimized to avoid web breakage and to 
permit rapid acceleration of the web to make one graphics transfer after 
another. The structure and function of the metering rolls will be 
discussed in more detail after the principle components of the thermal ink 
graphics transfer machine are all identified. 
The web advances away from metering rolls 98 and 99 to pass around 
successive idler rolls 101 and 102 and a roll 103 on a shuttle system 
which is designated generally by the numeral 100. The function and 
structure of the shuttle system will be discussed in detail later. After 
passing around the shuttle roll 103, the web 95 goes around an idler roll 
105 and, after passing a detector 106 for a registration mark 211 the web 
moves along and in contact with an elongated platen 107 with the opposite 
side from the inked side of the web bearing on the platen. The platen is 
heated with temperature regulated electric heaters to warm the ink which 
is necessary for it to be released from the web substrate. The web emerges 
from the heated platen 107 and passes between a roller 108, of eight 
identical rollers, on typical transfer head 70 and the periphery of a 
container at the decorating station 9 which is the place where the 
graphics or thermal transfer ink images are rolled onto rotary containers 
15 in succession. 
At this juncture it is important to observe, particularly in FIG. 5 the 
physical relationships of the components of the machine and their 
translational and rotational characteristics, for it is these 
relationships, according to the invention, which permit decorating 
containers at a higher rate than any other relationships and 
characteristics which are known. Specifically, one should observe that the 
transfer head 70 is on one side of the web 95 and the turntable 12 and a 
container 15 are on the opposite side of the web from the transfer head. 
The rotational axes of the transfer head 70 and the turntable 12 are 
parallel except in the special case where the transfer head is adjusted to 
a small angle from vertical for tapered container decorating. The 
turntable 12 and transfer head 70 rotate in opposite directions but their 
tangential or linear components of motion at the decorating station where 
graphic transfer is occurring are the same. The containers 17 on disks 15 
rotate in a direction indicated by the arrow 109 while being translated in 
the opposite direction by the turntable as indicated by the arrow marked 
110. The peripheral surface of a container 17 is moving in the same 
direction as the web 95. In the embodiment shown, the web is moving in a 
direction opposite of the turntable 13. Under some conditions the web may 
be required to move in the same direction as the turntable. An example 
would be where the rotational velocity of the container is less than the 
rotational velocity of the turntable. What is always true, according to 
the invention is that the container 17 always rotates in a direction 
opposite of the rotational direction of the turntable 12 and the transfer 
head 70 always rotates in a direction that is opposite of the rotational 
direction of the turntable. The rollers 108 on the transfer cylinder roll 
in the direction of the web and roll and rotate on the back of the web. 
After an ink image is transferred to a container, the now bare web passes 
between a pair of pinch rollers called capstan rollers 112 and 113. One of 
these rollers is driven rotationally by a servomotor that is under base 
plate 10 and is not visible in FIG. 8 but will be discussed later in 
reference to FIG. 13. It is sufficient to recognize for the moment that 
the capstan drive system is operative to accelerate or retard the web 
travel rate to correct any small discrepancy between the position of the 
graphics entering the decorating station and the position of the 
container. The capstan system assures that graphics will start to transfer 
at the identical place on each container. This is important because it 
assures that if labels or graphics are applied to the front of a container 
at one place, for example, graphics can be placed exactly diametrically 
opposite at the back of the container or on the neck of the container if 
it is a bottle. 
After the web transits the capstan rollers 112 and 113, the web goes around 
another shuttle system roller 104 and then around idler rollers 114, 115 
and 116. Then the web passes between pinch rollers 117 and 118 which are 
web tensioning rollers. One of the rollers 117 or 118 is driven with a 
differential gear system and a servomotor which are positioned under base 
plate 10 so they are not visible in FIG. 8 but will be shown and discussed 
in reference to other FIGURES later. 
After leaving the web tensioning rollers 117 and 118, the web goes through 
a dancer roll system and then passes on to a motor driven rewind reel 92. 
A transfer station position adjusting mechanism 125 is mounted to base 
plate 10. It is conventional and is used in various pre-existing labeling 
machines, for example. Mechanism 125 acts on bed plate 126 to provide for 
raising and lowering of the plate and to moving it backward and forward 
for the transfer cylinder rollers 108 to align with the proper place on a 
container 15 in the graphic transfer station. 
Now that the major components of the machine have been identified the 
details of the individual components will be considered by way of the 
different drawings and in conjunction with FIG. 8. 
Refer to FIG. 13 for a discussion of the capstan drive. A servomotor 130 is 
mounted to the bottom of bed plate 126. Coupled to the shaft of the 
servomotor is driven roller 113 which was identified in FIG. 8. The upper 
end of roller 113 has a ball bearing 131 whose outer race is fixed in 
plate 132 which is supported on posts 133 and 134 of a total of four 
posts, two of which are not visible in FIG. 13. Either pinch roller 112 is 
journaled in bearing box 135 and 136. Web 95 is passing between rollers 
112 and 113 in FIG. 13 and the web is being pulled by these rollers which 
are driven by servomotor 130. 
As mentioned earlier briefly, the registration mark photodetector 106 in 
FIG. 8 sends a signal to the programmable controller in console 11 shown 
in FIG. 1 when the detector cites a graphics location indicating 
registration mark passing. The controller is always counting clock pulses 
at a rate of 1,000 counts per pitch, as an example of what is done in an 
actual embodiment of the machine. An encoder, not shown, produces signals 
indicative of the instantaneous rotational angle of the turntable and, of 
course, the position of a container that will be the next to enter the 
decorating station 9. Knowing where the container is and knowing where the 
graphic is because of the photodetector signal, the drive signal for 
servomotor 130 causes the servomotor to run at a speed that results in the 
leading edge of the graphics of the web to make first contact with a 
container at the exact place that it should. Because the position of 
everything involved is relative to a high count rate, in this example 
1,000 counts per pitch, graphics precision on the container as good as one 
part per thousand can be obtained. 
FIG. 14 shows a plan view of the capstan drive including rollers 113 and 
112. Roller 112 is on a swingable pressure bar 137. In FIG. 14, one may 
see that the web 95 is departing from the transfer head 70 and is passing 
through the capstan rolls on its way to the metering system which is shown 
in FIG. 11 and will be discussed in more detail later. 
A section through a transfer head 70 is shown in FIG. 5. The rotor of the 
head itself is marked 136. In this particular embodiment, there are eight 
roller assemblies including previously mentioned rollers 108. One roller 
is presently traversing the transfer station 9 and is in contact with the 
backside of the web which is being pressed by roller 108 against the 
periphery of a container 15 which is on its support disk 17 and is 
rotating counterclockwise as viewed from the top and oppositely of the 
transfer head 70 as a whole. It will be evident that the graphics are not 
simply pressed on the container but are rolled on. The rollers are on 
carriages such as the one marked 137 and are slidable and pressed toward 
the container by a spring 138. Thus the rollers can retract and advance to 
maintain contact with the periphery of the container after the transfer 
head passes the radial line on which the axis of roller 137 the axis of 
transfer head shaft 139 and the support disk shaft 140 are coincident with 
the same straight line. It will be evident also that the roller 108 has to 
be advanced radially outwardly to meet the oppositely translating 
container 15 as the container enters the transfer station area 9. The 
transfer head is provided with a plurality of housings 141 in which there 
are electric heater elements, not shown, for heating curved metal 142 
which span between rollers 108. Each of the heating element assemblies in 
housings 141 are associated with temperature controllers 143 that maintain 
the temperature of the segments 142 very close to a specified temperature 
over the entire axial length of the segments and, hence, over the entire 
width of the web as the web is kept hot by the segments as long as 
possible before the rollers 108 become active to press the web against the 
container 15 periphery. Each heater element in the housing 141 has an 
individual temperature controller. 
The shuttle assembly 104 is shown enlarged in FIG. 15. The shuttle device 
consists of commercially available components. The shuttle is comprised of 
an air cylinder 146 which contains a piston, not visible. A piston rod 147 
is attached to the piston and has a clevis 148 attached to it. The clevis 
connects the piston to a carriage 149 by way of a pin 150. A bracket 151 
extends from carriage 149 and contributes to guiding the carriage on a 
magnetizable rod 152. There is air under pressure in the cylinder on one 
side of the piston. This pressure is held very constant and is regulated 
closely. Cylinder 146 is coupled by way of a pin 153 passing through 
suitable holes in a roller carriage 154 and a protuberance 155 which is 
fixed to the cylinder 146. The carriages 149 and 154 are slidable on and 
guided by a fixed rod 156. A bracket 157 extends from carriage 154 and is 
slidable on rod 152 with carriage 151 but the carriages can move 
independently of each other since one is connected to the piston rod and 
the other is connected to the cylinder. The positions of the carriage are 
sensed with a sensor device 158 using magnetostriction phenomena. The 
output signal of sensor 158 represents the time interval between 
initiation of an interrogation pulse and detecting a return of the pulse 
along rod 152. The interrogation pulse is generated by the sensor's 
electronics and travels at the speed of light. A pulse or physical strain 
travels back to the sensor 158. Some magnetic fields interact and are 
processed by the electronics, not shown, and they yield a signal 
indicative of the distance by which the brackets 151 and 157 are separated 
which is equivalent to the distance by which rollers 103 and 104 are 
separated. In an actual machine, a Temposonics LH position sensor 158 is 
used but other methods for sensing the relative positions of the rollers 
103 and 104 such as deriving signals from potentiometers, not shown, could 
be used. 
The metering roll system is illustrated in FIGS. 10 and 11. The metering 
roll pairs 98, 99 and 117, 118 were previously identified in connection 
with FIG. 8. These pinch rolls are shown in FIG. 10 as well. In FIG. 10 
one may see that the pinch rolls 99 and 117 are pressed toward the driven 
rolls 98 and 118, respectfully, on pivotal arms 166 and 167 and which are 
biased by a pneumatic cylinder 168. 
The overall metering roll system is depicted in FIG. 11. The driven 
metering rolls 98 and 118 are rotated in ball bearings that are mounted in 
plates 169 and 170. The plates are maintained in parallelism with posts, 
one of which is identified by the numeral 171. The main electric metering 
motor is marked 172. A toothed pulley on the shaft of this motor is marked 
173. Toothed pulley 173 drives a toothed belt 174 which engages with a 
pulley 175 that drives roller 108 rotationally. The belt also engages a 
toothed pulley 176 on the shaft of a differential device 177. The 
differential has a pulley 178 on its shaft and there is a comparable 
toothed pulley 179 on roller 118. A motor 180, called the tensioning 
motor, drives differential 177. 
The conventional unwind and rewind reel systems are depicted in FIG. 9. 
Each is provided with a dancer roll system that is familiar to those 
involved in the labeling art as a way to store a length of web at the 
input or output to a roll so that if web is drawn rapidly, it can be paid 
out from storage by the dancer system when needed. There are motors, not 
shown, for driving the unwind reel 91 and the rewind reel 92. The sensors, 
that monitor the storage condition of the dancer systems 73 and 87 are not 
shown but are represented in FIG. 4. Since the rolls 91 and 92 rotate 
about horizontal axes, it is necessary to impart a twist in the web for 
the web to pass through the machine from infeed to outfeed by means of 
rolls marked 181 and 182 in FIG. 9. 
FIG. 12 shows a special centering head that is used when thin wall cans are 
being decorated. In such cases the can 189 must be pressurized interiorly 
or its sidewall will collapse under the force of spring biased roller 108 
during the graphics transferring step. Before the can 189 arrives at 
transfer station 9, a hollow piston 190 is pressed onto the top of the can 
out of a cylinder 191. When the piston 190 is pressed onto the top of the 
can, it moves a plunger 192 upwardly. Cylinder 191 is fastened to a 
cylindrical air chamber 193. Air chamber 193 provides a pressurized plenum 
194 to which an air supply hose 195 is connected. Cylinder 193 has a valve 
seat under a valve ball 196. When the piston is not engaged with a can, 
the valve is biased toward closed position by a spring 197. When the can 
is engaged, plunger 192 raises valve 196 from its seat to allow air to 
flow into the can. In an actual machine, the air pressure was chosen to be 
40 psi. When the can is engaged, piston 190 is able to turn in a needle 
bearing 198 at high speed. In an actual machine, byway of example and not 
limitation, the piston rotates at a speed of about two revolutions per 
pitch for a commonly used bottle size. It must rotate at high speed in 
order to be coordinated with the previously mentioned innovative 
relationship between the rotational direction of the turntable, the 
rotational direction of the containers on the turntable, the translational 
direction of the web, and the rotational direction of the graphics 
transfer head which, according to the invention, are related to obtain 
ideally high container decorating rates. Suitable seals are provided to 
prevent air leaks. The piston rotates in a seal having a U shaped cross 
section and which is marked 199. There is another seal 200 between the 
cylinder 191 and cylindrical chamber 193. The whole pressure head is 
driven downwardly with a ram 201 whose downward force is limited by 
interposing a spring 202 between the ram and the cap 203 of the 
combination centering bell and pressurizing assembly. The cap 203 is 
maintained in accurate vertical alignment with a guide rod 204. 
Operation of the machine will now be summarized in reference to FIGS. 4 and 
8, particularly. In FIG. 4, the first thing that happens is for a sensor 
209 to sense the presence of a container entering the machine. The sensor 
provides a signal to programmable controller (PLC) 11 that a container is 
present. The PLC knows where the container is because it has data 
referencing to the turntable angular position and to the container pitch 
in the turntable. The PLC 11 is counting clock pulses continuously at a 
rate of 1,000 per pitch, by way of example and not limitation. An encoder 
210 makes one revolution per container pitch and provides this information 
by way of a signal to the PLC for the PLC to be able to interpret 
container position in terms of clock pulses. 
The capstan rollers 112 and 113 actually pull web through the image 
transfer station 9. The capstan drive system comprises rollers 112, 113 
and servomotor 130. The capstan drive system has the responsibility of 
assuring that the graphics on web 95 will begin to roll on every container 
at the transfer station at precisely the same position on every container. 
The graphics registration sensor 106 determines the position of the 
incoming graphics by detecting a registration mark 211 which is at a known 
distance from the next thermal ink transfer graphics on the web. This 
information is signaled to the capstan drive which can now determine if 
the graphic is too far advanced or retarded relative to the position of 
the container for precise positioning of the graphic on the container. 
The capstan drive system is controlled to change its drive speed in an 
anticipatory fashion, that is, the capstan servomotor 130's speed must be 
modified in advance of the time that the transfer of the graphic should 
begin. So the capstan system pulls web in a direction away from metering 
rolls 98 and 99 to get the graphic and the place on the container where 
the graphic should be applied to coincide. 
Since web has been drawn out of the infeed side of the transfer station 9 
and web has been yielded to the rewind side of the transfer head, tension 
force exerted by the web to the shuttle shifts the shuttle to the left in 
FIG. 8. The shuttle roller 104 is on a carriage that connects to the 
shuttle piston rod 147 which extends from the invisible piston in shuttle 
cylinder 146. Constant air pressure on the piston results in the web 
tension being maintained constant provided the piston is never allowed to 
bottom out. However, the shuttle has shifted which means that the amount 
of web on opposite sides of the transfer station 9 must be equalized. As 
mentioned earlier, separation of shuttle rollers 103 and 104 is determined 
for enabling determination of the shuttle piston position. FIG. 4 shows 
two shuttle sensors which are collectively indicated by the numeral 158 
since the magnetostrictive sensing system is bidirectional. 
Preventing the piston in cylinder 146 from bottoming out is accomplished 
with a differential drive in the web metering system. This system includes 
the rollers 99, 108, 117, 118, metering motor 172, differential drive 177 
and tensioning motor 180. If no correction in piston position in shuttle 
cylinder 146 is necessary, the metering drive system allows the same 
amount of web into the shuttle as it takes out. If correction is required, 
the tensioning motor 180 drives the differential 177 in the proper 
direction either to add or take away web to center the piston. This 
actually happens while the metering system is supplying web and decorating 
is taking place. Thus, web tension is adjustable but accurately 
controllable. 
Continuing with the description of machine operation in reference to FIG. 
4, the rewind buffer 73 and 87 are identified and correspond to the dancer 
systems which were previously mentioned. The amount of web in storage 
between the unwind reel and metering rollers 98 and 99 and from the rewind 
roll to metering rollers 117 and 118 is determined with optical detectors 
212 and 213. These detectors signal the rewind drive system, and 
particularly the motor that drives the reels, to effect taking in some of 
the stored web and the unwind buffer 87 does the same thing except that it 
controls the unwind drive system motor.