US3345940A

US3345940A - Ribbon feed mechanism

Info

Publication number: US3345940A
Application number: US467495A
Authority: US
Inventors: Ralph B Porter; John A Maul
Original assignee: Multigraphics Inc
Current assignee: DBS Inc
Priority date: 1965-06-28
Filing date: 1965-06-28
Publication date: 1967-10-10
Anticipated expiration: 1984-10-10
Also published as: GB1139251A

Description

06$ 1967 R. B. PGRTER ETAL R IBBON FEED MECHANI SM 4 Sheets-Sheet 1 Filed June 28, 1965 INVENTORS. IFAI. PH 51 PORTER JOHN A. MAL/L fiwwzzf/gat ATTORNEY Oct. 10, 1967 R. B. PORTER ETAL RIBBON FEED MECHANISM 4 Sheets-Sheet 2 Filed June 28, 1965 an w:

wm ll Q m 0 N N m m w 3 ow oh N R A Q m N l F 3 NM 5 A R 5 a W M m mm ANN m o T mm mm P J A Oct. 10, 1967 Filed June 28, 1965 R. B. PORTER ETAL RIBBON FEED MECHANISM 4 Sheets-Sheet 5 INVENTORS. RALPH B. PORTER OHN A. MAL/L C/IQ ATTORNEY.

10, 1967 R. B. PORTER ETAL 3,345,940

RIBBON FEED MECHANI SM Filed June 28, 1965 4 Sheets-Sheet 4 IIIIII [I] V 1N VENT 0R3.

F4439 5 PQFTEI? z/0///V A. MAI/L BYMOKW A TTOPNE Y,

m7 n M 4 United States Patent 3,345,940 RIBBON FEED MECHANISM Ralph B. Porter, Willoughby, and John A. Maul, Lyndhurst, Ohio, assignors to Addressograph-Multigraph Corporation, Cleveland, Ohio, a corporation of Delaware Filed June 28, 1965, Ser. No. 467,495 12 Claims. (Cl. 101-336) ABSTRACT OF THE DISCLOSURE A data recorder for imprinting forms from embossed printing plates using a transfer ribbon and a manually operated roller platen, has a printing head which supports both the roller platen and the transfer ribbon and is mov+ able with respect to a base between a closed printing position and an open non-printing position. Movement of the head to the open position is efliective to drive a take-up spool and thereby advance the ribbon to present a fresh portion of the ribbon at the printing station. The driving action is generated by a gear fixed on the base in mesh with a driven gear rotatable on the head. Sensing means, and ribbon feed control means responsive thereto, render the ribbon advancement uniform regardless of the diameter of the ribbon accumulation on the take-up spool. This feed control includes a pawl and ratchet mechanism, embodied in the take-up spool drive, whose effective throw is governed by a shroud cam positioned by the sensing means (which feels the diameter of the ribbon accumulation). The cam determines the point at which the pawl is permitted to engage the ratchet and hence adjusts forward motion of the take-up spool.

.The present invention relates to a ribbon feed mechanism and, more particularly, to a mechanism for automatically advancing a ribbon by a predetermined length from a supply spool to a take-up spool regardless of the amount of ribbon on the take-up spool.

Although the ribbon mechanism of the present invention may be utilized in a wide variety of applications, wherein it is desirable to have the ribbon indexed in predetermined increments, the mechanism of the present invention will be described in connection with data recorders adapted to imprint forms from embossed plates or cards. Such data recorders are utilized in numerous installations such as automotive service stations, department stores and the like, to imprint the customers name, address and account number from the embossed card onto a sales slip and, additionally, may be provided with key set levers for imprinting variable data such as the money amount of the sale. A data recorder of the character referred to is shown and described, for example, in US. Patent No. 3,138,091.

The forms imprinted in data recorders such as the above, in addition to being imprinted with human sensible alphanumeric data, are usually also imprinted with coded or machine readable data. The coded data may correspond to the account number and money amount of the sale, and are adapted to be scanned by automatic data processing equipment. Accordingly, because of the requirements of the automatic scanning equipment to properly read the imprinted coded data, it is frequently necessary that the code impressions on the forms be made using carbon paper, either so that pigments which will be effective in the operative wave length range of optical scanning equipment can be put down on the sheet, or so that sharp, uniform deposits readable by magnetic scanning equipment can be formed.

There are data recorders currently in use which meet the requirements set forth above, but in doing so they Patented Oct. 10, 1967 require an expensive multiple part form including at least one carbon sheet. These machines utilize a dry or uninked roller platen which is rolled in pressure engagement across the form overlying an embossed card to provide a dense image as a result of the interleaved carbon paper in the form set. Since there are many data collection systems wherein it is advantageous to imprint a single part form with machine scannable data, such as in manufacturing for direct labor reporting, production, inventory, tool crib control and the like, it is an object of the present invention to provide a carbon ribbon mechanism for a data recorder to permit imprinting highquality machine scannable data either onto a single form, or onto the top sheet of a carbon set form.

It is another object of the present invention to provide a ribbon mechanism which automatically indexes the ribbon at predetermined amount after each printing cycle so as to continually rnove fresh ribbon to the printing position and prevent exhaustion of the transfer coating.

Another object of the invention is to provide a mechanism for advancing a ribbon by means of the take-up spool, but to do so in a way that provides equal increments regardless of the amount of ribbon wound on the take-up spool.

Another object of the invention is to provide a ribbon advancing mechanism for use in a data recorder, wherein the ribbon is automatically advanced under control of the operation of the data recorder.

Still another object of the invention is the provision of a ribbon feed mechanism for a data recorder so arranged that the ribbon will be automatically removed to clear the printing area at the end of each printing operation to permit easy changing of printing elements and documents.

By using the principles of the invention it is possible to create impressions on a single part form which have the pigment density and/or an impression quality such that the impression thereon will be accurately interpreted by the data processing equipment.

According to one form of the present invention the foregoing objects are attained by providing a ribbon mechanism in the platen-carrying printing head of a data recorder of the kind having the head mounted for movement on the base of the machine and movable toward and away from a printing position. The ribbon is threaded from a supply spool across the underside of the head to a take-up spool. Means are provided for sensing the amount of ribbon wound on the take-up spool and thereby controlling the advance of the ribbon so as to feed it a predetermined amount after each printing operation, during the movement of the printing head away from the printing station, which amount remains substantially constant from one feeding stroke to another.

Other objects, features and advantages of the present invention will be apparent from the following description and claims and are illustrated in the accompanying drawings which, by way of illustration, show a preferred embodiment of the present invention and the principles thereof now considered to be the best mode contemplated for applying these principles. Other embodiments of the invention embodying the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art without departing from the present invention and the purview of the appended claims.

In the drawings:

FIG. 1 is a condensed plan view of a printing head of a data recorder partially broken away, incorporating a ribbon mechanism constructed in accordance with the present invention;

FIG. 1a is a side elevation of a data recorder according to the invention, showing an alternate position of the printing head in dotted lines;

FIG. 2 is a condensed front elevation of the printing head and ribbon mechanism shown in FIG. 1;

FIG. 3 is a section taken on the line 33 of FIG. 2 showing a ribbon supply assembly;

FIG. 4 is a section taken on the line 44 of FIG. 2 showing a latch arrangement for releasably retaining a ribbon mask;

FIG. 5 is a section taken approximately on the line 55 of FIG. 2 and shows a ribbon take-up assembly and associated ribbon advancing mechanism;

' FIG. 6 is a section taken on the line 66 of FIG. 5; FIG. 7 is a section taken on the line 77 of FIG. 5; FIG. 8 is a detail view on a reduced scale showing component parts of the latch assembly and taken on the line 8-8 of FIG. 1 with the platen carriage omitted and the platen shown diagrammatically in other positions;

FIG. 9 is a section taken'on the line 99 of FIG. 8; and

FIG. 10 is a section taken on the line 101) of FIG. 8.

The ribbon mechanism of the present invention provides a relatively simple arrangement which can be incorporated in various types of data recorders. For purposes of this specification, the novel arrangement is described as being incorporated in a machine such as shown and described in the aforementioned US. Patent No. 3,138,091. The printing machine includes a base B (FIG. 1a) affording a support for a printing device bearing data to be printed. A printing head indicated generally at 10 in FIGS. 1, 1a and 2 is mounted on the base and includes a roller platen 12 mounted on a platen carriage 28 manually movable along the printing head to imprint the data from the printing device onto a form interposed between the base and the printing head. The printing head 10 is pivotally mounted on the base B by means of a shaft 120 and is movable between a printing position and a non-printing position, sometimes referred to as an inactive position. The machine also includes a latch arrangement comprising a pair of spring-urged pawls 14 and 16 (FIGS. 2, 8, 9 and 10) to latch the printing head automatically to the base of the printing machine whenever the printing head is moved to its printing position, the pawls also being so interconnected as to release the printing head automatically upon completion of a printing operation when the platen strikes the pawl 16, whereupon the head is automatically raised by a biasing means to be described hereinafter.

The novel ribbon mechanism of the present invention comprises a ribbon supply assembly mounted on the left side of the printing head 10, as viewed in FIGS. 1 and 2, and indicated generally at 18, and a ribbon take-up and advancing assembly mounted on the right side of the printing head 10 and indicated generally at 20 in FIGS. 1 and 2. A ribbon 22 is led from a supply spool 24 of the assembly 18 under the roller platen 12 and to a takeup spool 26 of the assembly 20. While the ribbon 22 may be of any suitable kind, in order to produce images on the form having a high degree of clarity, it is preferred to utilize a carbon coated Mylar ribbon of the one-timeuse type.

In operation a printing member is placed on the base B with a form lying on its upper surface. Then the printing head 10 is latched in its printing position as shown in full lines in FIG. 1a, and the platen carriage 28 is moved from left to right as viewed in FIG. 2 to effect rolling pressure engagement of the roller platen 12 against the ribbon and the form to imprint the latter from the embossed printing device positioned on the base B of the machine. On completion of the imprinting operation, when the roller platen reaches the right end of the machine, the carriage 28 strikes the pawl 16 and the printing head 10 is automatically released to its non-printing position as shown in dotted lines in FIG. 1a and the ribbon is advanced a predetermined length to present an unused 4- portion of the ribbon at the printing station for a subsequent imprinting operation, in a manner to be further explained hereinafter.

The ribbon supply assembly is shown in FIGS. 1, 2 and 3 and comprises a housing 30 having a removable front cover 32. A shaft for rotatably supporting one end of the ribbon spool 24 is provided with an enlarged end 34 rotatably journalled in a boss 36 in the rear wall of the housing and a reduced section 38 which extends forwardly toward the front cover 32. The shaft is retained in the boss 36 by providing a pin 40 through the diameter of the enlarged end 34 at the inside face of the boss, and a drag is applied to the shaft to keep the ribbon taut by positioning a spring 42 around the enlarged end 34 and between the outside face of the boss and a knob 44 for manually rotating the shaft. The ends of the pin 40 extend beyond the diameter of the shaft end 34 and are received in a pair of notches 46 provided in the end face of the spool 24 to afford a driving connection between the shaft and the spool. It will be seen that the spring 42 urges the shaft 34, 38 to the right as viewed in FIG. 3, thereby urging the extended ends of the pin 40 against the inside face of the boss 36 to effectively retain the shaft in the boss.

The other ends of the shaft section 38 and the spool 24 are rotatably supported in a bearing member indicated generally at 48 which is journalled in a boss 50 provided in the front cover 32. The bearing member comprises a knob 52 provided with a body 54 and a pintle 56, the body and pintle having a blind axial hole 58 therein for the reception of the end of the shaft section 38. The body 54 is rotatably received in the boss 50 and the pintle 56 supports the other end of the spool for rotation thereon.

The front cover 32 of the assembly 18 is removable from the housing 30, of course, to permit access to the inside of the housing when replacing the ribbon. This is accomplished by providing one or more pins 60 (only one pin being shown in FIG. 3 of the drawings) in the housing such that the pins project outwardly toward the front cover. The pin 60 is provided with a head 62 which enters a recess 64 in the front cover to thereby properly position the cover when it is being placed on the housing. Additionally, the pin 60, in conjunction with a spider 66, serves as a latching means to secure the front cover to the housing. In this regard, the spider 66 is rigidly mounted on the body 54 of the bearing member 48 and is provided with radially extending arms, one for each pin 1 60. Thus, when the knob 52 is rotated in a clockwise direction as viewed in FIG. 2 and from the left in FIG. 3, the spider 66 is rotated to cause the arms to frictionally engage the rear of the head 62 of each of the pins 60 to thereby latch the front cover to the housing. Rotation of the knob 52 in the opposite direction is effective to rotate the arms out of engagement with the pins and to release the cover for removal from the housing. It will be appreciated, with the arms of the spider disengaged from the pins, to remove the cover it is merely necessary to withdraw the bearing member 48 from the spool and, the bearing member, spider and front cover are all removed as a unit. To replace the cover on the housing, the blind hole 58 in the bearing member and the recess 64 in the cover are pushed onto the end of the shaft 38 and the head 62 of the pin respectively, and the knob is rotated to position the arms of the spider 66 in latching engagement with the pins 60.

As shown in FIGS. 1, 2 and 4, the printing head 10 includes a pair of

side plates

70 and 72 which are secured to a channel member 78, for example, by a pair of mounting

brackets

74 and 76 which are welded or otherwise attached to the inner surfaces of the

side plates

70 and 72 and the under surface of the channel member. A template or mask is provided on the underside of the printing head and is adapted to be pivotally movable between a closed position against the channel 78 as shown in FIG. 4, and an open position to permit threading the ribbon 22 from the supply spool assembly 18 to the takeup spool assembly 20. The mask 80 is provided with suitable cutouts which correspond to the parts of the form to be imprinted overlying the printing plate and, if present, other printing devices such as fixed information plates, date wheels and variable data print wheels.

The mask 80 is pivotally mounted to the inside of the

side plates

70 and 72 by means of screws 82, only one being shown in FIG. 4 of the drawings, and is retained in its closed position by a latch device indicated generally at 86. Although there are two latch devices provided in the machine, one adjacent the inside surface of each of the

side plates

70 and 72 as shown in FIG. 1, since they are both alike only one latch device will be described herein.

The latch device 86 comprises a sliding member 88 having a pair of elongate holes 94 and 96 therein. The holes 94 and 96 are positioned over a pair of pins 98 and 100 respectively, provided in the side plate 70, and the member 88 is held in place by providing a C washer 101 on the pin 100, and by positioning a spring 102 from the pin 98 to an. ear 104 formed out of the slide 88. Thus, the spring 102 is effective to urge the slide 88 in a forward direction, to the left as viewed in FIG. 4, to thereby maintain a nose portion 90 thereof in engagement with an opening 92 provided in the mask 80. To place the mask 80 in its open position, both sliding members 88 are pulled rearwardly, by grasping a finger grip such as 110 provided thereon, against the action of the spring 102 to withdraw the nose portion 90 out of the opening 92 in the mask 80 to permit the mask to pivot downwardly about the screws 82. After the ribbon 22 is in position, the mask is pushed upwardly and is cammed over the nose portion 90 to position the opening 92 in latched engagement therewith. The ribbon is positioned against the upper surface of the mask, under the roller platen 12 and through a wide notch 112 provided in the lower margin of each of the

side plates

70 and 72.

The printing head is pivotally mounted by means of rod 120 as indicated in FIG. 1a. The rod 120 has a pivotal connection with the base B, and portions of the rod are square in cross section and pass through square openings 121 (FIGS. 1 and 7) in the

side plates

70 and 72 to provide a driving connection therewith. Suitable biasing means 33 shown in FIG. 1 is provided for urging rotation of the rod 120 in a direction to open the printing head when the

latches

14 and 16 are released as will now be described.

The printing head 10 includes latching means for latching the printing head to the printing machine base upon movement of the printing head to the lower, printing position. These latching means are so mounted within the printing head as to retain the printing head in its printing position until the platen roller is moved sufficiently far to complete the printing operation, whereupon a final movement in the same direction is effective to disengage the latching means and thereby enable the printing head to return to the upper, non-printing position as illustrated in dotted outline in FIG. la.

The latching means comprising the

pawls

14 and 16 are shown in detail in FIGS. 8 through 10 of the drawings. The

pawl members

14 and 16 are pivotally mounted internally of the channel member 78 by respective pivot pins 11 and 13. With particular reference to FIGS. 9 and 10, it is seen that the pivot pins are fixed within the forwardmost flange 78L of the channel member. A bar 17 extends along the inner surface of the forwardmost depending fiange 78L of the channel member 78 and includes a depending leg 17L Which extends downwardly adjacent the pawl 16. The lower portion of the depending leg 17L is connected by a pin 19 to the pawl 16 at a point below the pivot pin 13. At its opposite end, the bar 17 is connected to the pawl 14 by a pin 21 disposed above the pivot pin 11. Thus, the bar 17 forms a link interconnecting the two pawl members. The bar 17 is provided with an enlarged opening 31 which encircles the pin 13 so as to permit movement of the bar in the direction indicated by the arrows C-C in FIG. 8 and thereby enable the pawl members to be pivoted about the pivot pins 11 and 13 between the positions indicated by the bold and phantom outlines in FIG. 8. A spring 23 is connected at its opposite ends to the inner end of the pivot pin 11 and to a lug 25 formed on the lower edge of the bar 17. The spring 23 pulls the bar 17 to the left, as viewed in FIG. 8, to bias the lowermost ends of the

pawl members

14 and 16 toward the inner, latching positions illustrated in the bold outline of FIG. 8.

Referring now to FIG. 8, the base B includes a pair of lugs 27 (only one being shown in the drawings) which are positioned to be engaged by the

pawl members

14, 16 whenever the printing head 10 is moved downwardly t0 the printing position as illustrated in FIG. 2. The manner in which the pawl 16 latches with the lug 27 is illustrated in FIG. 8 in the bold outline. The upper surfaces of the lugs 27 are slightly beveled, as are the lower and inner edges of the

pawl members

14 and 16 so that the lower ends of the pawl members are rotated outwardly by a camming action during downward movement of the printing head. Once the printing head is moved downwardly a sufiicient distance, the spring 23 is effective to bias the

pawls

14 and 16 inwardly to the latched position illustrated in the bold outlines in FIG. 8. Thereafter the spring 23 is effective to retain the pawls, and therefore the printing head, in this position until the latching pawls are disengaged at the termination of the printing stroke of the platen roller. r

The platen roller 12 is reciprocably movable along the channel 78 and is engageable with the inner vertically extending edges of the

pawl members

14 and 16 in the manner illustrated in FIG. 8. Engagement of the platen roller 12 with the pawl member 16 pivots the pawl member outwardly and simultaneously effects a similar pivoting movement of the opposite pawl member by reason of the resulting movement produced in the bar 17 interlinking the two pawl members. Thus, assuming that the platen roller assembly is moved to the right from a position adjacent the pawl member 14 to the position indicated in phantom outline in FIG. 8, in the process of imprinting a form positioned in the printing station, the platen roller 12 engages the pawl member 16, pivots the pawl member in a counterclockwise direction about the pivot pin 13 and moves the pawl member to the unlatched position indicated in the phantom outline. Simultaneously, the bar 17 is pulled to the right, as illustrated in FIG. 8, by the pin connection 19, rotating the pawl member 14 in a clockwise direction about the pivot pin 11 to the unlatched position illustrated by the phantom outline. Biasing means, described below are effective to move the printing head 10 upwardly upon release of the latch pawls 14 and 16. The spring 23 then returns the

pawls

14 and 16 to the positions shown in the bold outline.

The biasing means for raising the printing head 10 upon completion of a printing operation comprises a torsion spring 33 which is mounted on the rod (FIG. 1) and connected in a conventional manner to act between the rod 120 and the base B so as to exert a continuous biasing force on the printing head, urging the head 10 toward the upper, non-printing position. Thus, upon disengagement of the pawl members from the lugs 27, the spring 33 moves the printing head upwardly. In the device of the present invention the rod 120 also extends outwardly through the side plate 72 and into a housing 122 of the take-up spool assembly 20 as shown in FIG. 7. The portion of the rod extending into the housing is circular in cross section and is received in a boss 124 provided in a wall of the housing. A spiral gear sector 126 is mounted on the rod and has an integral sleeve 128 which spaces it from the boss 124. The sector with its sleeve is held on the rod by providing a threaded end on the rod and applying retaining nuts 130. The design of the sector and the rod is such that the rod is free to rotate in the sector but the sector is held against rotation relative to the base B by a bracket 132. This bracket is positioned on the sleeve 128 and is secured at its upper end to one face of the sector 126 by fastening means 134. The lower end of the bracket is formed with a depending offset which extends outwardly through an opening in the bottom of the housing 122 and terminates in a pair of spaced feet 136 positioned to rest against the upper surface of base B. In this way, when the printing head is moved between printing and inactive positions, the feet 136 prevent the sector 126 from rotating with the rod 120. While other arrangements could be utilized to hold the sector against rotation, the arrangement disclosed herein offers the advantage of attaching the ribbon mechanism of the present invention to existing data recorders, such as shown in the above identified patent, with only a minimum amount of alterations required to the machine.

The ribbon take-up spool 26, and the manner in which it is mounted, is essentially the same as the supply spool described above. Additionally, however, the take-up assembly includes mechanism to effect advancement of the ribbon after each printing operation. With reference to FIG. 5, the spool 26 is rotatably mounted at one end on a bearing member indicated generally at 140, and at the other end on an enlarged portibn 142 of a shaft 144. The bearing member is also rotatably journalled in a front cover 146 of the housing 122, and is provided with a knob 148 for manually rotating a spider 150 into and out of engagement with pins 152 to effect locking and unlocking of the front cover in the same manner described in connection with the supply spool assembly 18. Further, one end of the spool 26 is provided with a notch 154 drivingly engaged with a pin 156 in the enlarged portion 142 of the shaft, and any free spinning of the shaft is prevented by a drag spring 158 positioned on the end 142 of the shaft and between a bearing bracket 160 for rotatably supporting the shaft end 142, and a ratchet wheel 162 pinned thereon which will be described herein below.

Another shaft 164 is provided and extends coaxially of the spool 26 and rearwardly therefrom to a position slightly beyond and directly above the spiral gear 126. Shaft 164 is rotatably supported in

bushings

166 and 168 provided in

ribs

167 and 169 respectively. A shroud cam 170 and a gear sector 172 integral therewith are loosely mounted on the shaft 164 with the cam 170 adjacent the ratchet wheel 162. An arm 174 for mounting a combination pawl and cam follower device is also fixed to the shaft 164 at a position between the gear sector 172 and the rib 167. Pivoted thereto at 180 is a pawl 176 which coacts with the ratchet wheel 162, and which has an integral cam follower lug 178 which extends outwardly from one face of the pawl and is adapted for engagement with the periphery of cam 170. The pawl 176 is urged toward the ratchet wheel and cam by a spring 182 interposed between the pawl and a recess 184 provided in the arm as shown in FIG. 6. The arm 174 carrying the pawl 176 is rotated with the shaft 164 between the full line and dotted line positions shown in FIG. 6 each time the printing head is actuated as will be further explained below.

A spiral gear wheel 186 is pinned on the shaft 164 at a position between the

ribs

167 and 169 and in mesh with the spiral gear sector 126. Thus, as the printing head 10 is moved between printing and non-printing positions, the gear wheel 186 remains in mesh with the stationary sector 126 to impart rotation to the shaft 164 in a clockwise direction as seen in FIG. 6.

The bracket 168 for rotatably supporting the shaft end 142 is secured to suitable ribs such as 188 and 206 by screws 190 as shown in FIGS. 1 and 5 of the drawings. Additionally, however, the bracket 16! also rotatably supports one end of a shaft 192, the other end of the shaft being journalled in a bushing 194 provided in a rib 196 of the housing 122. The end of the shaft 192 supported in the bracket 168 extends outwardly therefrom and has a sensing member 198 pinned thereon. The sensing member is preferably made of molded plastic and is provided with a smooth finger 200 adapted to ride against the surface of the ribbon 22 wound on the take-up spool 26, (FIGS. 1 and 5). It will be understood that member 198 and finger 2% actually occupy a position in FIG. 5 nearer to the observer than the plane of the section through the spool 26, as can be seen from FIG. 1, to simplify the showing in the drawing. Adjacent the other end of the shaft 192, and up against the rib 196, is a gear segment 292 which is pinner on the shaft and in mesh with the gear sector 172. Further, a torsion spring 204 is provided on the shaft, positioned between the gear segment 202 and the rib 206 to urge the sensing member in an anticlockwise direction as viewed from the right in FIG. 5 to thereby maintain the finger 200 in slight pressure engagement with the periphery of the ribbon on the spool 26.

The housing 122 is also provided with a removable side cover 288 which is fastened to the housing with suitable screws 209. The inside face of the cover is provided with bosses 218 (only one being shown in FIG. 1) which engage a fiat face 212 provided on each of the

bushings

166, 168 and 194, to thereby maintain the bushings against dislodgement when the cover 288 is mounted on the housing.

The overall operation of the novel ribbon mechanism of the present invention, as incorporated in a data recorder, will now be described. The front covers 32 and 146 of the

housings

38 and 122 respectively, are removed by rotating the

knobs

52 and 148 in an anticlockwise direction as viewed in FIG. 1. With the printing head 10 in raised or non-printing position, the latch devices 86 are actuated to release the ribbon mask and permit it to pivot downwardly about the screws 82. The supply spool 24 having the ribbon 22 wound thereon is slid onto the enlarged end 34 of the shaft 38, with the notch 46 of the spool engaged with the pin 40, and the ribbon 22 is withdrawn from the spool and threaded across the underside of the printing head and onto the take-up spool 26 positioned on the shaft section 142. The free end of the ribbon may be provided with adhesive, and the same is thereby attached to the take-up spool. The

covers

32 and 146 are then replaced on the housings 3t) and 122, with the hearing members 48 and rotatably supporting the other ends of the

spools

24 and 26 respectively, and the covers are locked into position by rotating the

knobs

52 and 148. The mask 80 is then closed against the printing head where it is retained by the latch devices 86 and the data recorder is in condition to perform printing operations.

A form to be imprinted is placed on top of an embossed printing device on the base of the machine, and the printing head is moved to its closed or printing position where it is held in latched engagement with the base of the machine by the

pawls

14 and 16. Next, the platen carriage 28 is moved through a printing stroke from the left to the right as viewed in FIG. 2, to thereby cause the roller platen 12 to apply rolling pressure contact to the ribbon 22 against the form to produce an impression thereon from the embossed plate. When the platen 12 reaches the end of its printing stroke, the printing head is automatically released from the base as described hereinabove and returns to its inactive position. At the same time, the platen carriage 28 is restored to start position as shown in FIG. 2, either by the operator or by a suitable return spring (not shown).

The ribbon mechanism is effective to advance the ribbon the same distance, regardless of the amount of ribbon wound on the takeup spool, after each printing operation. This movement of the ribbon takes place at the time the printing head is being raised or restored to its non-printing position. Referring to FIG. 5, it can be seen that as the printing head is pivoted in a clockwise direction, worm wheel 186 remains in mesh with the worm sector 126 which is held against rotation by the bracket 132, and will thus impart rotation, in a direction seen as clockwise in FIG. 6, to the shaft 164 and, of course, to the arm 174 which is pinned thereon. During this rotation of the shaft 164, the pawl 176 on the casting 174 is engaged with the ratchet wheel 162. Accordingly, the pawl rotates the ratchet wheel and the shaft 142 to which it is pinned, as well as the take-up spool 26 through the driving connection afforded by the notch 154 in the spool and the pin 156 in the shaft. The ribbon is kept taut by the action of the drag springs 42 and 158 positioned on the shafts 34 and 142 respectively.

As the spool 25 is rotated and the ribbon is wound thereon, the build up of the ribbon on the spool is detected .by the sensing finger 200 which is in continual engagement with the surface of the ribbon on the spool, thereby causing the sensing member 198 to be rotatively moved a distance corresponding to the added thickness of the ribbon diameter on the spool. This moving of the sensing member 198 is clockwise as seen from the right in FIG. and is effected against the action of the spring 204 which, of course, serves to maintain the finger 200 of the sensing member against the ribbon on the spool.

Since the sensing member 198 is fixed on the shaft 192, the rotative movement ofthe sensing member imparts rotative movement to the shaft 192 and to the gear segment 202 which is pinned thereon. Gear segment 202, in turn, is in mesh with the gear sector 172 which, as mentioned above, is integral with the cam 170 and loosely mounted on the shaft 164. Thus, as the gear sector 172 is rotated by the gear segment 202, cam 170 is also rotated slightly in an anticlockwise direction as viewed in FIG. 6 for a purpose to be explained presently.

The arm 174 assumes the position shown in full lines in FIG. 6 when the printing head 10 is in closed or printing position, and it rotates with the shaft 164 to the dotted line position when the printing head is raised to non-printing position. In this way, when the printing head is being closed against the base of the machine, the pawl 176 mounted on the arm 174 merely idles over the teeth of the ratchet Wheel 162. However, when the printing head is raised to inactive position, the pawl 176 is engaged with the ratchet wheel 162 and rotates the same in a clockwise direction as viewed in FIG. 6.

Although the arm 174 is moved the same distance for each printing stroke of the machine, the ratchet wheel 162 is rotated a shorter distance each machine cycle so that the ribbon will continue to be advanced about the same distance regardless of the amount of ribbon wound on the take-up spool. The distance that the ratchet wheel is rotated is under control of the cam 170 which is, as mentioned hereinabove, positioned by the

gear sectors

172 and 202, as a result of the sensing member 198 detecting the diameter of the ribbon wound onthe spool 26. As shown in FIG. 6, the cam 170 is provided with a low-level edge 214 extending from a point P to a step or rise 216. Thus, as the printing head 10 is opened, the cam follower 178 rides on or slightly clear of the edge 214 of the cam, and the pawl 176 is engaged with the ratchet wheel 162 to rotate the same. When the cam follower engages the step 216, the latter is effective to pivot the pawl out of engagement with the ratchet wheel and thereby terminate the ribbon feeding stroke. At the same time, the slight build up of ribbon on the spool causes the cam to be rotated slighty in an anticlockwise direction as viewed in FIG. 6, thereby minutely shortening the time during which the cam follower 178 is opposite the low-level edge 214 of the cam for the next printing operation.

For each succeeding printing stroke, the cam continues to be stepped around such that the pawl 176 is caused to be engaged with the ratchet wheel for shorter intervals as a result of the step 216 being gradually moved toward the start position of the pawl. Accordingly, it will be understood that as the ribbon builds up on the take-up spool, the ratchet wheel is rotated through gradually diminishing angles to thereby advance the ribbon in approximately 10 equal amounts irrespective of the diameter of the ribbon wound on the spool.

Obviously the ribbon advancing mechanism of the present invention could be designed to advance the ribbon any desired predetermined distance. However, when utilized in a data recorder as described herein, it has been found that extremely good printing impressions are obtained when the ribbon is advanced in increments of approximately inch. While this movement of the ribbon might vary slightly from one printing stroke to another, the exact distance the ribbon is advanced is not critical and, therefore, need not be held to a precise value.

From the foregoing description, it will be appreciated that the ribbon mechanism of the present invention provides a novel arrangement for automatically advancing a ribbon a predetermined distance after each printing operation, to thereby provide a continuous renewal of the ribbon at the printing station. The amount of travel of the ribbon remains constant for each printing stroke regardless of the amount of ribbon wound on the take-up spool so that the renewal rate will be adequate at the start of the ribbon feed and still will not become wasteful as the diameter of the roll on the take-up spool increases.

Additionally, incorporating the ribbon mechanism in a data recorder permits imprinting single part forms, as well as multiple part forms, with high quality impressions having the degree of clarity and/ or density, to permit accurate machine scanning of the imprinted forms, as a result of continuously and uniformly renewing the ribbon. While a preferred embodiment of the invention has been described and illustrated, it is to be understood that it is capable of variation and modification. Accordingly, the

aim in the appended claims is to cover all such variations and modifications as may fall within the true spirit of the invention.

What is claimed is;

1. In a ribbon mechanism for a data recorder of the kind having a printing head pivotally mounted on a base and movable between a printing position and an inactive position, in which said printing head includes a platen,

the combination comprising:

means including a takeup spool mounted on the printing head for supporting a transfer ribbon for advancement across the printing head;

advancing means of the positive drive type actuated by the movement of the printing head from printing position to inactive position to wind the ribbon on the takeup spool;

means to detect the diameter of the ribbon wound on the spool; and means controlled by said detection means for so conditioning the advancing means as to provide for the advancement of the ribbon in substantially uniform increments at each movement of the printing head from printing position to inactive position.

2. Ribbon mechanism as set forth in claim 1 in which the advancing means comprises:

a first shaft in driving engagement with the takeup spool; a second shaft coaxial with the first shaft and rotatable in either direction;

means for rotating the second shaft under control of the movement of the printing head between printing and inactive positions;

and means effective to rotate the first shaft when the second shaft is rotated in one direction, and ineffective to rotate the first shaft when the second shaft is rotated in the opposite direction.

3. In a ribbon mechanism for a data recorder of the kind having a printing head pivotally mounted on a base and movable between a printing position and an inactive position, in which said printing head includes a platen, the combination comprising:

means including a take-up spool mounted on said printing head for supporting a transfer ribbon for advancement across said printing head;

advancing means under control of the movement of said printing head to wind said ribbon on said take-up spool;

means to detect the diameter of said ribbon wound on said spool; and

control means responsive to said detection means for controlling the extent of ribbon advancement effected by said advancing means;

said advancing means including:

(a) a first shaft in driving engagement with said said take-up spool,

(b) a second shaft coaxial with said first shaft and rotatable in either direction,

() means effective to rotate said first shaft when said second shaft is rotated in one direction, and ineffective to rotate said first shaft when said second shaft is rotated in the opposite direction,

(d) a pair of meshing gears, one of which is fixed on said second shaft, and

(e) means to hold the other gear stationary with respect to said base whereby the stationary gear is effective to rotate said second shaft in said one direction when said printing head is moved to inactive position, and to rotate said second shaft in the opposite direction when said printing head is moved to printing position.

4. In a ribbon mechanism for a data recorder of the kind having a printing head pivotally mounted on a base and movable between a printing position and an inactive position, in which said printing head includes a platen, the combination comprising:

advancing means under control of the movement of said printing head to wind the ribbon on said take-up spool;

means to detect the diameter of said ribbon wound on said take-up spool; and

control means responsive to said detection means for controlling the extent of ribbon advancement to provide for substantially uniform advancement of the ribbon at each operation of the printing head between printing and inactive position;

said advancing means comprising a pawl oscillatably driven by movement of said printing head, and a ratchet drivingly connected with said take-up spool and coacting with said pawl; and

said control means comprising a movable cam means cooperable with said pawl for determining the arc of its driving contact with said ratchet and means controlled by said detecting means for determining the position of said cam means.

5. A data recorder comprising a base; a printing head, including a platen, pivotally mounted on said base and movable between a printing position and an inactive position; means including a takeup spool mounted on the printing head for supporting a transfer ribbon for advancement across the printing head; and means to drive said takeup spool to advance the ribbon comprising a first gear centered on the pivotal axis of said base and head and non-rotatably associated with said base, and a second gear carried by said head and meshing with said first gear.

6. A data recorder comprising a base; a printing head, including a platen, pivotally mounted on said base and movable between a printing position and an inactive position; a shaft pivotally relating said base and head; means including a takeup spool mounted on the printing head for supporting a transfer ribbon for advancement across the printing head; and means to drive said takeup spool to advance the ribbon comprising a first gear on the shaft and a second gear mounted on the head adjacent the shaft and meshing with said first gear, and means attached to said first gear arranged for contact with said base for preventing rotation thereof relative to said base.

7. A data recorder as set forth in claim 6 in which the means to drive said takeup spool comprises in addition a pawl and ratchet drive driven by said second gear; and which further includes means to alter the drive of said takeup spool to provide a substantially uniform ribbon advance including means for detecting the diameter of the takeup spool, and means responsive to said detecting means for controlling the extent of driving contact of said pawl with said ratchet.

8. A data recorder comprising:

a bed for receiving printing elements and documents;

a printing head pivotally mounted on said bed for movement between a printing position and an inactive position;

a roller platen supported on said printing head and movable across said bed for making impressions;

means mounted on said printing head for supporting a transfer ribbon supply with a reach of the ribbon in printing position between said roller platen and a document on said bed;

ribbon moving means on said printing head for feeding said ribbon from the ribbon supply to renew the ribbon at the printing position;

a first gear centered on the pivotal axis of the bed and head and non-rotatably associated with said bed;

a second gear carried by said printing head and meshing with said first gear;

means drivingly associating the second gear with the ribbon moving means to actuate the ribbon moving means when the head is pivotally moved from printing position to inactive position; and

means responsive to completion of a printing stroke of the roller platen for causing pivotal movement of the head from printing position to inactive position.

fi. A data recorder as set forth in claim 8 in which the means for causing pivotal movement of the head includes latch means for holding the printing head in printing position, said latch means being positioned to be acted upon and released by the platen as it completes a printing impression, and spring means urging the printing head from printing position to inactive position and active to move the same when released by the latch means.

10. A data recorder comprising:

a bed for receiving printing elements and documents;

a printing head pivotally mounted on said bed and movable between an elevated inactive position relative to said bed and a lowered printing position;

a transfer ribbon extending across said printing head with a reach of said ribbon in printing position between said platen and a document on said bed;

a supply spool mounted on one side of said printing head and a take-up spool mounted on the opposed side of said printing head for supporting said transfer ribbon for advancement across said printing head;

means to detect the diameter of said ribbon wound on said take-up spool; and

said advancing means comprising a first gear non-rotatably associated with said bed, a second gear carried by said printing head and meshing with said first gear, a pawl oscillatably driven by said second gear in response to movement of said printing head, and a ratchet drivingly connected with said take-up spool and coacting with said pawl; and

11. A data recorder as set forth in claim 10 which further includes latch means for holding the printing head in printing position, releasable by the platen as it completes a printing impression, and spring means for moving the printing head from printing position to inactive position when released by the latch means, and in which the pawl and ratchet are arranged for causing ribbon advancing motion of the take-up spool during the raising motion of the printing head from printing to inactive position.

12. A ribbon feed mechanism for uniformly advancing a ribbon comprising:

means including a take-up spool for supporting a ribbon;

a first shaft in driving engagement and coaxial with said take-up spool;

a ratchet drivingly associated with said first shaft;

a second shaft coaxial with said first shaft;

means to drive said second shaft with an oscillating motion;

a pawl drivingly associated with said second shaft and cooperating with said ratchet;

a third shaft parallel with said first and second shafts;

a sensing member at one end of said third shaft for engaging the surface of the ribbon accumulated on said spool;

a shroud cam mounted for rotary movement about the axis of said ratchet and cooperating with said pawl for controlling the degree of driving contact of said pawl with said ratchet;

means to urge said third shaft in a rotary direction to maintain said sensing member in contact with the ribbon surface;

and means drivingly connecting said third shaft with said shroud cam for rotating the same in response to rotary movement of said third shaft.

References Cited UNITED STATES PATENTS 607,226 7/ 18-98 Diss.

981,808 1/191 1' Steele 197151 1,165,662 12/1915 Freeman 197161 1,410,357 3/1922 Adams 101336 1,465,741 8/ 1923 Sheras.

1,852,645 4/ 1932 Dugdale 101336 X 1,926,355 9/ 1933 Tarlton 10l336 2,026,115 12/1935 Anthony l01274 2,634,533 4/1953 Hahn 101-33-6 2,664,819 1/1954 Janke 101336 X 2,692,555 10/ 1954 Gruver 101-336 3,138,091 6/1964 Maul 101-45 ROBERT E. PULFREY, Primary Examiner.

E. T. WRIGHT, Assistant Examiner.

Claims

1. IN A RIBBON MECHANISM FOR A DATA RECORDER OF THE KIND HAVING A PRINTING HEAD PIVOTALLY MOUNTED ON A BASE AND MOVABLE BETWEEN A PRINTING POSITION AND AN INACTIVE POSITION, IN WHICH SAID PRINTING HEAD INCLUDES A PLATEN, THE COMBINATION COMPRISING: MEANS INCLUDING A TAKEUP SPOOL MOUNTED ON THE PRINTING HEAD FOR SUPPORTING A TRANSFER RIBBON FOR ADVANCEMENT ACROSS THE PRINTING HEAD; ADVANCING MEANS OF THE POSITIVE DRIVE TYPE ACTUATED BY THE MOVEMENT OF THE PRINTING HEAD FROM PRINTING POSITION TO INACTIVE POSITION TO WIND THE RIBBON OF THE TAKEUP SPOOL;