Paper Roll Holder With Dancer Bar for Use With Printers and the Like

The present invention relates to paper supply means and more particularly to a novel paper supply holder for use with a printer and having a dancer bar for assuring orderly feeding of the web from the supply reel, and which is especially advantageous for use with web feeding means of the incremental-feed type.

Printers of the high-speed type have a capability of printing under control of a computer or communications link receiver in which sheets of paper would have to be changed rather rapidly due to the printing speed capability of such printers. In order to limit the number of paper feed operations required to be performed per unit time, it is typical to adapt the printer to receive and feed paper from a continuous elongated web of indeterminate length. A web of this nature is typically provided in a large supply roll. The web is arranged to rotate upon a supporting shaft or pin to enable feeding of the paper web from the supply reel. The support for the supply roll is preferably of the free-wheeling type to enable the paper to be fed rapidly without being torn. However, a free-wheeling support of this type also carries with it the disadvantage of allowing the supply reel to continue rotation due to the large inertia of the supply reel and due to the force imparted to the supply reel through the pulling force exerted on the outermost layer of the paper web, thereby enabling the paper web to begin to unravel and feed more paper than is necessary during a paper feed operation. This is particularly disadvantageous when utilizing large paper web supply reels with printers of the incremental paper-feed type, which impart an abrupt pulling force upon the paper web.

The present invention is characterized by providing a highly-simplified and yet unique paper roll holder which is adapted to allow the paper web to be substantially freely unraveled and which is provided with dancer bar means adapted to yield its quiescent position to provide for the orderly feeding of the web by allowing an increment of linear length of the web already unwound from the supply roll but not yet fed into the printer to be rapidly fed into the printer while causing the paper supply roll to unwind slowly as the incremental paper feed mechanism pauses after a line feed and during the subsequent printing of each line. In addition, the dancer bar imparts sufficient drag to the paper web to prevent more than the desired amount of paper web to be fed from the supply reel, thus maintaining the web on the supply reel substantially fully and tautly wound and preventing the supply reel from unraveling to feed more paper from the supply reel than is required due to the performance of a web of an incremental paper feed operation.

It is therefore one object of the present invention to provide a paper supply roll holder for use with a printer paper feed device and which is adapted to rotatably support a supply roll and feed the paper web from the supply roll in a neat and orderly manner.

Another object of the present invention is to provide a paper supply roll holder of the character described hereinabove and which utilizes a dancer bar assembly resiliently supporting an unwound portion of the web for preventing the paper supply roll from unraveling more paper than is required.

Still another object of the present invention is to provide a paper supply roll of the character described hereinabove and in which the dancer roll assembly utilizes spring means for buffering the impact of an abrupt line feed operation to prevent the abrupt movement of the paper web from reaching the supply roll.

Still another object of the present invention is to provide a novel paper supply roll holder for use with a printer and having resilient locking arms for releasably engaging cooperating mounting openings provided on said printer, so as to positively locate the paper supply roll holder and hence the paper supply roll relative to said printer.

Still another object of the present invention is to provide a novel paper supply roll holder having an axle with slideably-mounted end cap members for adjustably positioning a paper supply roll upon said axle and further for accommodating paper supply rolls of different axial lengths.

The above, as well as other objects of the present invention, will become apparent when reading the accompanying description and drawings in which:

FIG. 1a shows a side elevational view of a paper supply roll holder designed in accordance with the principles of the present invention and showing a portion of the elements of a printer associated therewith.

FIG. 1b shows a partial top plan view of the assembly of FIG. 1a.

FIG. 2a shows a detailed side elevational view of the holder of FIG. 1a with the paper supply roll removed.

FIG. 2b shows a front elevational view of the paper supply roll holder of FIG. 2a.

FIG. 3a shows a top plan view of a portion of the holder of FIG. 2a.

FIG. 3b shows a front elevational view of a support portion of the paper supply roll holder of FIG. 2a.

FIG. 4a is a top plan view of one spring and a portion of the dancer bar of FIGS. 1a and 2a and the manner in which said spring supports one end of the dancer bar.

FIG. 4b shows a side view of the spring of FIG. 4a.

FIG. 5a shows a top plan view of the paper supply roll axle of FIGS. 1a and 2a.

FIG. 5b shows a right-hand end view of the axle of FIG. 5a.

FIG. 5c shows a left-hand end view of the axle of FIG. 5a.

FIG. 5d shows a sectional view of the axle of FIG. 5a looking in the direction of arrows 5d-5d.

FIG. 5e shows a side view of one of the adjustable end caps of FIG. 2b.

FIG. 5f shows an end view of one of the end caps of FIG. 2b.

FIG. 1a shows a paper supply roll holder 10 designed in accordance with the principles of the present invention and is comprised of a support assembly 11, an axle assembly 20, and a dancer bar assembly 30. The paper supply reel 40 is comprised of a large roll of a paper web of indeterminate length, which is rotatably positioned upon axle assembly 20. The free end of the paper web extends from the underside of the supply reel, as shown best in FIG. 1a, and upwardly and over the top of dancer bar assembly 30 and thereafter downwardly and into the printer 50 comprised of a printer housing 51 supporting a rotatable paper feed roller assembly 52, rotatable pinch rollers 53, and a stationary paper supporting platen 54. The paper web moves upwardly through the gap provided between the printing surface of platen 54 and a slideably-mounted print head 55 mounted along a print head carriage supporting means 56.

The printer housing is provided with a shelf 57 facing the supply roll holder assembly 10 and having a pair of semicircular-shaped grooves 57a and 57b (see FIG. 1b), which are arranged immediately adjacent to substantially circular-shaped openings 57e and 57f, respectively provided in upright sidewalls 57c and 57d, which upright sidewalls are provided on opposite sides of shelf 57.

The paper supply roll holder assembly 11 can best be seen in detail in FIGS. 2a, 2b, 3a, and 3b, said holder support being comprised of an elongated rod, preferably of a metallic material and bent in such a fashion as to form: a support having a cross-piece portion 12a; two downwardly-depending substantially U-shaped support legs 12b and 12c; a pair of upwardly-extending side arms 12d and 12e; and a pair of downwardly-depending side arms 12f and 12g. A U-shaped axle support portion is provided between each pair of support arms 12d-12f and 12e-12g; for example, as shown best in FIG. 3a, wherein U-shaped axle support portion 12h is arranged between arms 12d and 12f. It should be noted that a U-shaped intermediate portion is provided between arms 12e and 12g which is substantially identical to the U-shaped portion 12h but which has been omitted herein only for purposes of simplicity.

The arms 12d and 12e, as shown best in FIG. 3b, can be seen to be arranged in substantially spaced parallel fashion. However, arms 12f and 12g can be seen to be bent slightly outwardly from the point where they are joined to the axle supporting portions (see axle supporting portion 12h) toward their outwardly-bent free ends 12j and 12k, respectively.

The metallic material from which the holder support 12 is formed has sufficient resiliency to enable the arms 12f and 12g to be sufficiently yieldable to be urged slightly inwardly toward one another and, when released, to resume their slightly outwardly-bent orientations, as shown in FIG. 3b. The outwardly-bent free ends 12j and 12k of holder support 12 are adapted to be releasably secured to the adjacent sidewall of the printer housing in the following manner:

The arms 12f and 12g are bent inwardly and are positioned so that their free ends 12j and 12k are aligned immediately above the semicircular-shaped recesses 57a and 57b, shown best in FIG. 1b. The free ends 12j and 12k are then pressed downwardly so as to be seated in the semicircular-shaped recesses 57a and 57b. In this position, the arms 12f and 12g are then released, whereby the arms move outwardly due to their normal resiliency, so that their free ends 12j and 12k respectively enter into the openings 57e and 57f in the sidewalls 57c and 57d embracing opposite sides of the printer shelf 57. In this manner, the supply roll holder 11 is secured to the printer 50 and is positively located relative to the printer housing 51 and further serves as the means for supporting and properly orienting the paper supply roll holder relative to the printer to assure smooth, proper operation thereof.

Considering FIGS. 3a and 3b, the arms 12f and 12g can be seen to be provided with reduced thickness portions 12m and 12n, whose top and bottom surfaces 12m-1, 12m-2, and 12n-1, 12n-2 are substantially flat. Each of said reduced thickness portions is provided with a pair of openings 13 and 14 adapted to receive fastening members 15 shown, for example, in FIG. 2. The openings 13 and 14 are preferably tapped to threadedly engage the threaded fastening members 15. The reduced thickness portions 12m and 12n are each adapted to position and support the mounting end 31a of a dancer bar supporting spring 31 shown best, for example, in FIGS. 4a and 4b. The mounting end 31a is provided with a pair of openings 31b for alignment with the tapped openings 13 and 14 in each arm 12f and 12g. The spring is bent at 31c, whereby a straight linear resilient portion 31d extends upwardly and away from the mounting portion, as can best be seen in FIG. 4b. The free end of each spring is bent as shown at 31e to form a substantially circular-shaped free end which is adapted to receive and embrace the small diameter end portion 32a of dancer rod 32. FIG. 4 shows one end portion of dancer rod 32, it being understood that the opposite end is substantially identical and receives a spring identical to the spring 31.

As shown best in FIGS. 1a, 1b, 2a, 2b, and 5a through 5c, each axle supporting portion, such as, for example, the axle supporting portion 12h of the holder support 12, is adapted to receive and freely rotatably support axle assembly 20 shown in detail in FIGS. 5a through 5c. The paper supply roll axle assembly 20 is comprised of an elongated portion 21 having a substantially X-shaped cross-sectional configuration, as shown best in FIG. 5d and which is comprised of four arms 21a-21d extending radially outward from the longitudinal axis of rotation 22. The cross-sectional configuration of FIG. 5d is a sectional view looking in the direction of lines 5d-5d of FIG. 5a.

A roller assembly 23 is integral with the left-hand end of elongated X-shaped axle member 21 and is comprised of a central cylindrical-shaped recessed portion 23a having a pair of circular-shaped disk-like flanges 23b and 23c arranged on opposite sides of intermediate cylindrical-shaped recessed portion 23a. The outer end thereof is provided with a tapered bore 23d for receiving a holding pin, to be more fully described.

The opposite end of elongated X-shaped axle member 21 has an integral end cap 24. End cap 24 has a substantially cylindrical-shaped periphery 24a and is similarly provided with a tapered bore 24b for receiving a holding pin, as will be more fully described.

The axial assembly 20 is further comprised of a pair of adjustable end caps 25 and 26, slideably mounted along elongated X-shaped axle member 21. Since both of these members are substantially identical in both design and function, only one of said members will be described herein for purposes of simplicity. Turning to a consideration of FIGS. 5e and 5f, it can be seen that left-hand end cap 25 (relative to FIG. 2b) has a disk-shaped portion 25a provided with a centrally-located circular-shaped opening 25b. A pair of slots extend radially outward from said centrally-shaped opening 25b and lie along a common diameter, said slots being shown at 25c and 25d, respectively.

A pair of substantially semicircular-shaped projections 26 and 27 immediately surround circular-shaped opening 25b. Each of these projections 26 and 27 is provided with a plurality of radially outwardly-extending projections 26a-26c and 27a-27c, respectively. The outer edges of these projections, for example, the outer edge of projection 26a-1 of projection 26a, is slightly tapered to facilitate insertion of the six projections 26a-26c and 27a-27c into the hollow core of a paper supply roll 40.

The end caps 25 and 25' are slideably mounted along X-shaped axle portion 21. The slots 25c and 25d provide the end cap disco-shaped portion 25a with some resiliency to allow the end cap portion to be slightly yieldable in order to allow the end caps to be slideably moved, either toward or away from one another in order to accommodate paper supply rolls of differing axial lengths and also in order to be able to center the particular paper supply roll mounted upon the axle assembly.

The manner of use of the axle assembly is as follows:

Presuming that the axle assembly 20 has been removed from the holder support 12, end cap 25' is completely removed from the axle assembly. Thereafter, the cap 24 is inserted into the hollow core 40a of the paper supply roll 40. The outer edges of the radially-aligned arms 21a through 21d do not engage the interior surface of the paper supply roll hollow cylindrical-shaped core 40a due to their substantially small diameter relative to the paper roll core 40a. The end cap 25 is pressed into the paper supply roll core 40a, which is centered upon the axle assembly. The fit between the hollow cylindrical core 40a of the paper supply roll 40 and the end cap 25 is a close press fit.

End cap 25' is remounted upon the axle assembly, and the projections of the end caps 25 and 25' are firmly force-fitted into the adjacent ends of the hollow cylindrical core 40a of the paper supply roll 40. Centering may be accomplished at this time or, alternatively, may be accomplished after the axle assembly is mounted upon the supply roll holder support.

After mounting of the paper supply roll 40 upon the axle assembly 20 and a light force-fitting insertion of the end caps 25 and 25' into the ends of the paper supply roll 40, the axle assembly 20 is placed upon the holder support 12 by positioning cylindrical-shaped recessed portion 23a of roller-like assembly 23 immediately above the left-hand U-shaped axle support portion 12h of support 12. The outer disk-shaped portions 23b and 23c prevent the axle assembly 20 from any movement along its longitudinal axis relative to support 12 while, at the same time, permitting the axle assembly to rotate freely about its longitudinal axis relative to support 12. The cylindrical-shaped cap 24, provided at the opposite end of axle assembly 20, simply rests upon the U-shaped axle support portion of support 12 which is arranged between arms 12e and 12g, as was previously described. It should be obvious that removal of the paper reel occurs in substantially the reverse order, wherein once the paper supply reel is exhausted, cylindrical-shaped cap 24 and roller assembly portion 23 are lifted upwardly and away from the support 12; end cap 25' is removed from the axle assembly; and the remaining hollow cylindrical-shaped core 40a of the exhausted paper supply roll 40 is removed, after which the steps employed for mounting a fresh paper supply roll 40 upon the axial assembly are the same as those described hereinabove.

With a fresh paper supply roll being mounted upon the axle assembly 20 and with the axle assembly 20 being mounted upon the U-shaped portions (see 12h) of the holder support 12, the paper may now be fed into the printer. Noting especially FIG. 1a, the paper is fed from beneath the supply roll 40, wherein paper portion P.sub.1 can be seen to be directed diagonally upward, so as to extend over the top of dancer rod 32. Thereafter, the paper extends over and upon the dancer roll 32 and then diagonally downwardly toward the printer housing 51 and into an opening in the adjacent side of the printer 50, where it passes between paper fed roller 52 and pinch rollers 53 and then upwardly along the right-hand side of feed roller 52, wherein the paper extends through the narrow gap defined by the printing surface of platen 54 and the forward nose 55a of print head 55.

The paper supply roll holder of the present invention may be used to great advantage with the printer of the type briefly described herein and described in greater detail in copending applications Ser. No. 40,911, filed May 21, 1979 and assigned to the assignee of the present invention. The printer described therein is provided with an incremental feed means (not shown in the present application for purposes of simplicity), which is arranged to drive the paper feed roller 52 in an incremental fashion. More specifically, the paper feed mechanism abruptly rotates the paper feed roller 52 through an angle usually of the order of 10.degree. to 20.degree., depending upon the particular line feed distance desired. The incremental line feed mechanism is adapted to abruptly feed the paper sheet. The fact that the paper sheet is pinched between pinch rollers 53 and paper feed roller 52 causes rotation of the feed roller 52 to be imparted to the paper web which serves to abruptly pull the paper web into the printer 50 and more specifically serves to pull the portion of the paper web P.sub.2 in the downward diagonal direction shown by arrow 57. The abrupt movement of the paper web causes the resilient dancer spring elements 31 to be urged downwardly so as to move from the solid-line position 31, shown in FIG. 2a, to the dotted-line position 31', also shown in FIG. 2a. Thus, abrupt movement of the paper web serves to urge the dancer bar 32 substantially in a downward direction, causing the dancer bar springs 31 to be flexed, as shown by the dotted-line configuration 31'. It can clearly be seen that the web portion P.sub.1 and the supply roll 40, yet to be unraveled, experiences effectively no movement whatsoever, the dancer rod 32 and the dancer rod support springs 31 serving to substantially fully absorb the abrupt movement imparted to the portion of the paper web extending to the right of dancer rod 32 (relative to FIGS. 1a and 2a).

Thereafter, the paper web feed operation typically pauses at least long enough for the printing of a full line. Since the web is substantially incapable of being stretched, the portion of the web extending between dancer rod 32 and the printer experiences no movement. However, the dancer rod springs 31 begin to move from their flexed position, shown by dotted-line configuration 31', back to their rest position, shown by solid-line 31 of FIG 2a, which return action is significantly less abrupt, i.e., the return of the springs 31 to their rest position occurs at a rate which is significantly slower than the original abrupt feeding applied to the paper web so as to gradually and substantially gently pull the large mass, high inertia paper supply roll 40 through an angle of rotation in the counterclockwise direction, as shown by arrow 33.

Even in the case where the paper feed mechanism is operated to perform a plurality of successively repeated feed operations, for example, to feed the paper web rapidly through ten "line feed" movements, the time required for the paper feed mechanism to return to its rest position before it performs its successive abrupt paper incremental paper feed operation is of sufficient length to allow the dancer rod 32 to enable the supply roll 40 to feed at a less abrupt and hence non-jerky manner. In addition, there is sufficient frictional drag between the dancer roll and the paper supply reel, which is substantially maintained in a somewhat-taught fashion, to prevent the paper from completely slipping about the dancer bar 32, so as to impart an abrupt pull upon the portion of the paper web to the left of the dancer rod 32 and the paper supply roll per se, thereby preventing the paper supply roll from unraveling unnecessarily, thereby assuring a neat, orderly unwinding of the paper web from the paper supply roll.

The tapered bores 23d and 24b, provided in end cap members 23 and 24 of the axle assembly 20, may be utilized to receive holding pins for facilitating the lifting and replacement of the axle assembly upon the holder support 12. For example, the members 23, 24 may be adapted to receive the tapered heads of a pair of blunt instruments to facilitate lifting of the axle assembly and paper supply roll. In addition, the axle assembly may be adapted for use with a holder support of alternative design, i.e., one in which the U-shaped support portions, such as support portion 12h of support 12 is eliminated and replaced with an inwardly-directed projection for insertion into tapered opening 23d. A similar projection may be provided at the opposite axle supporting end of the holder support for insertion into the tapered bore 24b, shown in FIG. 5d.

A latitude of modification, change, and substitution is intended in the foregoing disclosure, and in some instances, some features of the invention will be employed without a corresponding use of other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the spirit and scope of the invention herein.