CA1090196A - Precision imprinting with prescribed coding formats - Google Patents

Abstract

PRECISION IMPRINTING WITH PRESCRIBED CODING FORMATS

ABSTRACT

Imprinting of labels, tickets and the like with changeable, user prescribed coding formats. Precision imprinting which satisfies all format requirements is achieved by using reinforced and cleanable print bands with controlled roller inking and controlled feeding with dual feed fingers.

Description

1090196 ~

BACKGROUND OF THE INVENTION
This invention relates to lmprinting and more particularly to the precision imprinting of labels or tickets with prescribed coding formats.
When items are to be imprintable with the many different kinds of characters that can be encountered in practice, the imprinter must be able to accommodate a wide variety of formats.
Under some conditions, the imprinting will be with characters ~ where only user readability is required, and the characters are suitable if they can be distinguished by the users without regard t~o their precision. Under other circumstances, however, the characters are to be read by machine and precision imprinting is required to avoid errors. In such cases, a clarity and quality of printing are required which have not been attainable with traditional imprinters.
In the usual machine for the imprinting of tickets and labels, a print head is reciprocatable with respect to an inking pad where embossed characters on the bands of a print head are brought into pressure contact with the pad. The print head~is then moved to a position overlying the stock and impressed against it to produce the desired imprint. This arrangement tends to produce a nonuniform imprint because the impact and inking of the bands with respect to the ink pad tends to be nonuniform. While the resulting imprints are generally suitable for user readable characters, they are often unsuitable when the characters must be read by machine where relatively uniform ink density is needed. In addition the pressure contact of the bands with ink pads often produces smearing when the bands are sub-sequently brought into contact with the stock.
~ccordingly it is an object of the invention to improve the inking ~echanism by which the bands of a print head are inked for the imprinting of stock. Another object is to increase the uniformity of the imprint made by inked bands which are subsequent ly impressed on stock. Another object of the invention is to reduce the tendency for inked bands to produce smearing and unwanted depositsof ink on the stock Another characteristic of imprinters commonly encountered in practice is that the stock is fed over a platen using a recipro-cating pawl which moves the stock under the print head. This is accomplished by having a feed finger engage a notch in the stock and push it over the platen. The customary feed finger often proves inadequate to keep the feed of labels or tickets of vary-ing lengths relatively constant and prevent jamming. In addition, it is necessary to prevent the stock from backing up on the return stroke of the feed finger. This has typically required units requiring a great deal of adjustment in order to achieve proper machine operation.
Accordingly, it is a further object of the invention to facilitate the advance of stock in a reciprocating feed imprinter.
Another object is to accommodate labels and tickets of varying lengths while achieving relatively constant speed and preventing jamming in the machine. Still another object of the invention is to control the backup of ticket stock during the return stroke of the feed mechanism.
A further characteristic of prior imprinters with print bands has been that the bands tend to become clogged after extensive use. As a result, subsequent ticket impressions become fuzzy and relatively indistinct. The impressions are nevertheless usable where the tickets are read only by the users, but they are generally unsatisfactory where the tickets must be read by machine The us 1 correct1ve measure is to change the prlnt head. This is cumbersome and inefficient. It also adds an unnecessary complexity to the imprinting operation.
Accordingly, it is a further object of the invention to facilitate the cleaning of an imprinting machine. A related object is to achieve the cleaning of the machine without the need for replacing the print head. Another related object is to clean the bands of the print head while they are in position on the machine without disturbing the mechanism of the machine.
The print heads of the ordinary imprinter are generally made of a rubberized material with molded characters that provide a reasonable facsimile of the desired imprint. In these cases where tickets or labels are to be user read alone, variations in the character impressions do not prevent proper ticket usage.
However, where the tickets or labels are to be processed by machine, strict standards are required for the character imprint and the ordinary print bands have been found to be unsatisfactory, for example, in providing suitable character consistency from one imprint to another.
Accordingly, it is a further object of the invention to improve the print bands of machines used in the imprinting of tickets and labels. A related object is to achieve relatively consistent character impressions from one imprint to another.
Another difficulty with prior art machines has been that it had been difficult to adjust the machines when it became neces-sary to change the stock; for example, by changing from labels of one thickness to tickets of a greater thickness. The usual procedure is to make mechanical adjustments in the machine.
Not only are such adjustments time consuming, they cause in-creased complexity in the machine.
Accordingly, it is still another object of the invention to achieve stock changeability without the need for complex adjust-ments in the machine. A related object is to allow the same machine to be used for the imprinting of both tickets and label stock without making mechanical adjustments in the machine.
Representative examples of prior art imprinters are dis-closed in U.S. patents 3,899,971; 3,379,128; and 3,366,050.

SUMMARY OF THE INVENTION
In accomplishing the foregoing and related objects, the invention provides machine modifications and methods for precision imprinting with user prescribed formats.
In one measure for achieving the required precision of imprinting for decodable labels with machine readable codes, such as the optical character code, the invention provides a print head with compression or transfer molded bands that are reinforced by a compatible fibrous material. This special processing of the print bands assures relative stability of the print characters from one impression to another.
Precision feed is assured in accordance with one aspect of the invention by the use of dual feed fingers in conjunction with an antibackup roller.
Controlled inking is provided in accordance with another aspect of the invention by the use of a rack and pinion roller which contacts an inking supply during one stroke and rolls on the bands of the print head to apply an initial coating of ink which is smoothed on the return stroke of the roller. The inking supply can also be controlled to assure proper metering. of the ink on each inking roller.
Moreover, the inking supply is replacable by a solvent member which is used in conjunction with a cleaning pad that is inserted in place of the platen in order to clean the bands of the print head. This cleaning operation takes place automatically 1~90196 when the solvent and cleaning pads are placed in the machine, and the machine is operated for a prescribed number of labelling countc which can be set by the user.
In accordance with a further aspect of the invention, the solvent is selected to prevent damage to the constituents of the imprinter while having sufficient volatility that there is sub-stantially no dilution of the ink supply during subsequent machine operation.

DESCRIPTION OF THE DRAWINGS
Other aspects of the invention will become apparent after considering several illustrative embodiments taken in conjunction with the drawings, in which:
FIGURE lA is a perspective view of an imprinter in accordance with the invention.
FIGURE lB is a plan view of a representative ticket which has been imprinted with illustrative optical code characters in accordance with the invention.
FIGURE 2 is a perspective view of a representative print head assembly for the imprinter of FIGURE 1.
FIGURE 3 is a perspective view of a feed mechanism for the imprinter of FIGURE 1.
FIGURE 4 is a side view of an inking and platen assembly -for.the imrpinter of FIGURE 1.
FIGURE 5 is a block and schematic diagram of a control system for the inking and platen assembly of FIGURE 4.

DETAILED DESCRIPTION
Turning to the drawings, an overview of an imprinter 10 in accordance with the invention is shown in FIGURE lA. The principal operating elements of the imprinter 10 include a re-movable print head 20, a feed assembly 30, and an inking assembly 40 shown positioned beneath a removable dust cover 11. A pawer train for operating the inking and feed assemblies is contained within a housing 12.
. To operate the imprinter 10, the dust cover 11 is raised into position and the power train enabled by a switch 13 on a control panel 12c at the top of the housing 12. Imprinting is then initiated by depressing-a start button 14. The imprinting can be stopped by an operator at any time by depressing a stop button 15.
The number of labels or tags to be imprinted is dialed into a counter 16 and the unit stops automatically when the desired count has been attained. A second counter 45 is used in conjunc-tion with the inking assembly 40, as discussed below.
A supply hub 31 shown in FIGURE 2 (not visible in FIGURE lA) for labels is located in a hinged compartment 12s of the housing 12 in FIGURE lA.
The imprinter 10 of FIGURE lA is configured to provide precision imprinting regardless of the coding format employed.
The machine 10 is particularly suitable for the imprinting of labels and tickets with optically readable characters of the kind shown on the stock S in FIGURE lB.
The strip of stock S includes two labels, s-l and s-2 with feed apertures _ and perforations _ between adjoining labels on the partially imprinted strip S. The label s-l contains a middle line of character _-2, while the label ~-2 contains outer lines of chara t rs c-l and c-3. The characters, whlch are set on the print head 20 as discussed below, somewhat resemble those used in the imprinting of checks for machine processing and have the advantage of being both user and machine readable. It will be understood that the number of lines of coding, the parameters of the characters, and the distribution of code characters on the print head are a matter of choice.
The imprinter 10 of FIGURE lA may be used to provide labels with ordinary characters by simply interchanging the print head 20 with a print head providing the desired coding format. The imprinter 10 may also be used with a wide variety of non-user readable formats, such as the universal product code, by using a suitable print head.
It is to be noted in connection with the illustrative char-acters shown in the rows c-1 through _-3 of the illustrative labels s-1 and s-2 that precise character positioning and imprint-ing are required for correct machine reading. Thus the optically readable characters of FIGURE lB are intended to be read not only by fixed devices, such as at checkout counters, but also by hand held wands which are passed over the imprinted information for detection. In general, machine decoding can take place correctly only if the characters are imprinted with precision.
Thus each ticket or label includes marginal areas where no imprinting is permitted, failing which there will be an error in decoding. In addition each line of print must be properly separated, and the individual characters in any line of imprint must be correctly aligned. Moreover the character sizes and shape~
must meet prescribed criteria. Edge expansion of the characters, such as that caused by the improper metering of ink~ can cause incorrect decoding. The ink coverage must also be relativeiy uniform, and ink spots outside of the prescribed character area can cause decoding errors.

1090~96 The print head assembly 20 of FIGURE 2 illustratively has three sets of bands, B-l, B-2 and B-3, so that three lines of coding, c-l, c-2 and c-3, may appear on each imprinted item. The individual bands are set by knobs 21-1 and 21-3 on the right hand side of the print head 20 for the first and third lines -1 and c-3, while the knob 21-2 on the left side is used for the second line _-2. In setting the characters, each of the knobs 21-1 through 21-3 is moved until its pointer _ is over the individual band to be dialed, such as the band 22-a shown in phantom in FIGURE 2.
In producing the desired print bands, such as the band 22-a of FIGURE 2, base material is placed in a mold in slab form for compression molding and in liquid form for transfer molding. The base material is a polymeric substance such as urethane which is reinforced by a polyester fiber made, for example, from poly-ethylene terephalate. The urethane is a resin with a repeating structure of ethylcarbonate, also known as ethylurethane. Poly-ester fibrous material is chosen because of its compatibility with urethane. It has been discovered in practice that the re-inforcement of urethane with polyester provides a particularly stable character band. It is to be noted that bands reinforced in accordance with the invention cannot be produced by injection molding since the injection would damage the fibrous reinforce-ment.
As shown in FIGURES 2 and 3, the feed assembly 30 includes a forward finger 32f and a rearward finger 32r. A strip of labels passes from the supply roll 31 around a feed roller 33 to the adjustable feed fingers 32f and 32r. Each individual label or ticket on the strip S has a feed slot _ in the upper portion of lts per ration p as lnd~cated in FIGURE 3.

The extended finger 32f of the adjustable dual feed finger assembly 30 is shown locked into the slot a-l of a forward label s-l. The companion finger 32b is shown locked into the slot a-2 of a succeeding label s-2. The distance between the tip of the extended finger 32f and the finger 32r is adjustable by shifting a control knob 32-1 according to the width of the label being imprinted. The distance between the adjustable dual feed finger assembly 30 and the print head 20 is also adjustable by shifting a second control knob 32-2. The adjustable dual feed finger lQ assembly 32 is reciprocated in standard fashion to move the strip S to an adjustable print platen 22 (FIGURE 2) where imprinting occurs.
Backup of the labels is prevented during the return stroke of the feed assembly 30 by an anti-backup roller assembly 35.
The assembly is mounted to pivot along on axis A (FIGURE 3) which is parallel to the edges of the labels, and is held against the labels by an adjustable spring 35s, with a circumferential ridge 36r of a roller 36 in contact with a forward label s-f. The roller 36 includes a one-way roller mechanism of the kind shown in U.S. patent 3,899,971; so that there is no hindrance to label advance, but the contact of the rounded ridge 36r prevents label retraction. The labels can be advanced manually as desired by rotating the knob 36k in the direction indicated by the arrow B.
The adjustable print platen 22 of FIGURE 2 may be adjusted to accommodate varying thicknesses of labels and tickets. If the platen 22 is in position for the imprinting of labels, it may be lifted out of place by, for example, a platen lever (not shown).
The platen 22 may then be overturned and placed in a reverse posi-tion to permit the imprinting of tickets. For that purpose the platen 22 is configured to provide a different spacing relative to the print head for its original and reverse positions.

The inking assembly 40 shown in FIGURE 4 includes an ink roller 41, an ink pad 42, and a rack and pinion drive assembly 43.
The ink roller 41 is moved by the rack and pinion drive assembly 43 across the ink pad 42 and coated with ink as the adjustable dual feed finger assembly 30 moves the strip 15 to the imprinting position on the adjustable print platen 20. The ink roller 41 then moves beneath the print head 20 applying ink to the print bands such as the bands 22-a through 22-x, located in the print head 20. As the roller 41 returns to its original position, it smooths the ink applied to the print bands. The inking process is repeated for each label or ticket, ensuring that the same measured amount of ink is applied to each label or ticket.
The print counter 45, as shown in FIGURE 1, records the number of imprintings. The counter 45 automatically halts the imprinting process after a prescribed number of imprintings have occurred, illustratively 50,000. The ink pad 42 must then be replaced before the imprinting process can continue, ensuring that the same measured amount of ink is applied to each label or ticket.
A control system 50 for the inking assembly 40 is shown in FIGURE 4. For each operation of the imprinter a counter 51 is incremented. The output of the counter is applied to a register 52 with taps 52-a through 52-x corresponding to various pre-determined count levels. The attainmen-t of each count level pro-duces a signal applied through an OR gate 53 to an amplifier 54 whose output supplies a motor 55 which in turn rotates a gear assemblage 56 and moves the ink pad 42 relative to the roller 41 to maintain a suitable contact pressure between the pad and the roller 41. Where desired, each different tap of the reg ster 52 can be applied to a different amplifier in order to apply an in-creasing pressure as the count which corresponds to usage of the machine also increases. This compensates for the usage of ink during the printing operation.
In the particular embodiment of the inking control system 50 shown in FIGURE 5, the ink pad 42 is spaced from a support 45 by four screws 57-1 through 57-4, which bear against the pad 42. As the gear assemblage 56 is operated, the screws 57-1 through 57-4 are rotated and threaded out of the support 45, thus moving the pad 42 towards the roller 41 and its associated pinion and rack assemblage 43.
In order to suitably clean the print bands, 22-a through 22-x of FIGURE 4, without interfering with subsequent imprinting opera-tions, a special solvent is employed which does not damage either the print bands, or any of the associated apparatus, and at the same time has sufficient volatility to prevent any dilution of the ink supply during ensuing operations. A suitable solvent contains less than 1% aromatic constituents. The remaining 99%
are advantageously a mixture of approximately equal parts of paraffins and cycloparaffins, but paraffins or cycloparaffins alone may be employed.
The distillation range of a suitable solvent mix has an initial boiling point of approximately 240F and a dryness point of approximately 300F. In practice the distillation range can vary from about 212F. to about 350F. The solvent mix can be prepared by combining approximately 55% paraffins that are hexanes and above with approximately 45% cycloparaffins that are cyclo-hexanes and above.

The cleaning operation is effected by replacing the print pad 42 with a solvent pad, for example of tan foam, (not shown) and the platen 22 with a cleaning pad, for example of white felt, (not shown) of absorbent material.
The foregoing description and examples are illustratlve only and other adaptations, modifications and equivalents of the invention will be apparent to those of ordinary skill in the art.

Claims (10)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:-

1. Imprinting apparatus comprising a print head containing imprintable characters having a pre-scribed format, means for inking said characters, and means for advancing items to be imprinted with respect to said print head, characterized in that the advancing means includes dual feed fingers combined with a backup roller to assure relatively constant speed feed and avoid jamming in the machine while accommodating items to be fed of varying lengths.

2. An imprinter as defined in claim 1 wherein the print head includes a plurality of settable character print bands which are molded from a polymeric material and reinforced by a compatible fibrous material.

3. An imprinter as defined in claim 1 wherein the printing instrumentalities of said print head are inked using a roller which applies an initial coating of ink during a forward stroke and smooths the ink on the return stroke.

4. An imprinter as defined in claim 3 wherein the inking supply for said roller is controlled for proper metering of ink thereon.

5. An imprinter in accordance with claim 4 where the inking of said roller is controlled by changing the pressure applied between the ink supply and said roller.

6. An imprinter as defined in claim 4 wherein the inking supply is controlled by a counter which causes a change in the operation of said roller with respect to said ink supply.

7. An imprinter in accordance with claim 1 wherein said machine is used for the precision imprinting of tickets and labels with machine-readable codes, including optical and universal product codes.

8. An imprinter in accordance with claim 1 further in-cluding an inking supply which is replacable by a solvent member and used in conjunction with a cleaning pad that is inserted in place of a platen upon which imprinting otherwise takes place.

9. An imprinter in accordance with claim 8 wherein the solvent pad employs a solvent which does not damage the print bands and has sufficient volatility to prevent dilution of the ink supply during ensuing operations.

10. An imprinter in accordance with claim 9 wherein said solvent contains less than 1% aromatic constituents with a remaining mixture of approximately equal parts paraffins and cycloparaffins.