Printing Ribbon Indexing System

Abstract

A printing ribbon indexing mechanism for use with a printing mechanism utilizing a pair of operating hammer members. The indexing mechanism includes a printing ribbon supply reel mounted on a slip clutch, a take-up reel supplying tension to the ribbon, a pair of stationary rollers, a pair of movable rollers, each of which is mounted to one of the hammer members and a pressure roller mounted on a one-way clutch. Movement of either of the hammer members in a printing operation will allow the movable roller which is attached to that hammer member, to withdraw ribbon from the supply roller such that the hammer member will print on a new area of the printing ribbon.

Description

BACKGROUND OF THE INVENTION

The present invention is directed to a multiple hammer printer mechanism for printing data in the form of bars on a record tag and more particularly to an indexing mechanism for moving a printing ribbon past a pair of printing hammers. The printer mechanism utilizes a pair of printing hammers mounted in a side-by-side configuration, each of which is independently operated to pring on a record tag a series of bars of two different configurations, each of which represents coded information. The record tag may be attached to a merchandise item with the coded information relating to the price of the item and also providing inventory information. The record tag is read during the sale of the item by hand-held, optical probe scanner which is "squibbed" or glided across the record tag. Information from this reading is transmitted to a data collecting source or an electronic cash register from which merchandise operations are carried out and inventories are controlled.

SUMMARY OF THE INVENTION

In the printing of record tags on which coded information is to be utilized as part of a merchandizing operation, it is desirable that the cost of the tags be kept at a minimum. One of the areas of cost in the printing of these tags is the amount of printing ribbon which is used to print the coded information on the tags. It is desirable that all of the surface area of the printing ribbon be utilized in the printing of the tags. It is, therefore, an object of this invention to provide a ribbon indexing mechanism for supplying a printing ribbon to a printing station comprising a pair of printing hammers which will utilize fully the printing ribbon and which is simple in construction and, therefore, low in cost. In carrying out the object of this invention, there is supplied an indexing mechanism which comprises a pair of rollers, each of which is independently mounted to one of the pair of print hammers, a supply reel of printing ribbon which is mounted on a slip clutch for supplying ribbon to the print hammer, a take-up reel which supplies tension to the ribbon system, a pair of stationary rollers mounted between the movable rollers located on the hammers and a pressure roller mounted on a one-way clutch and which is operated in one direction by the ribbon pulled by the take-up reel. The movable rollers mounted on the printing hammers are positioned adjacent the stationary rollers and are movable upon the operation of the pring hammers in a printing direction to move new ribbon from the supply reel such that the actuated print hammer, upon reaching a printing position, will engage a new supply of ribbon.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a schematic representation of the indexing mechanism for advancing a printing ribbon from a supply reel to a take-up reel.

FIG. 2 is a diagrammatic representation of the printing ribbon showing the position of the ribbon at the time of the printing of the striped bar.

FIG. 3 shows the position of the ribbon after the hammer printing the striped bar has returned to its home position.

FIG. 4 shows the position of the ribbon at the time of the printing of the solid bar.

FIG. 5 shows the position of the ribbon after the hammer printing the solid bar has returned to its home position.

FIG. 6 shows the position of the ribbon at the time of the printing of a second solid bar.

FIG. 7 shows the position of the ribbon after the hammer printing the second solid bar has returned to its home position.

FIG. 8 shows the position of the ribbon at the time of the printing of a second striped bar.

FIG. 9 shows the position of the ribbon after the hammer printing the second striped bar has returned to its home position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1, there is shown a schematic representation of the indexing mechanism which includes a supply reel 21 of printing ribbon 22. The supply reel 21 is mounted on a hub 23 which, in turn, is connected to a slip clutch 16. The slip clutch 16 is of standard construction and will supply a drag on the supply reel 21 whenever the supply reel 21 is rotated. The printing ribbon 22 is threaded over a plurality of roller members 24 to 30 inclusive and a guide member 31 to a take-up reel 32. The take-up reel 32 provides constant tension on the ribbon system by means of being connected to the constantly rotating drive shaft 17 of a motor 18 through a slip clutch 19. The slip clutch 19 is of standard construction and similar to clutch 16. The tension supplied by the take-up reel 32 is sufficient to wind ribbon 22 onto the take-up reel 32 but is less than the drag supplied to the supply reel 21 by the slip clutch 16. Thus the take-up reel 32 will be unable to pull ribbon 22 from the supply reel 21. The printing ribbon 22 is engaged by a roller 33 rotatably mounted on a one-way roller clutch 20, the function of which will be described more fully hereinafter. The one-way clutch 20 is of standard construction, an example of which is disclosed in U.S. Pat. No. 2,240,359 issued to D. W. Weizel on Apr. 29, 1941. Associated with the roller 33 are a pair of pressure rollers 40,41. The roller 26 is mounted by means of support member 14 to a print hammer member 34 while roller 29 is mounted by means of support member 15 to a second hammer member 35. As shown in FIG. 4, hammer member 34 will print a striped pattern 36 while hammer member 35 will print a solid pattern 37.

In the operation of the printer, assume that hammer 34 will be activated to print a striped pattern 36 on a record tag (FIG. 2). The ribbon 22 is taut due to the tension supplied by the take-up reel 32. As the hammer 34 moves in a downward direction, roller 26 (FIG. 1) will also move in a downward direction creating a sag in the ribbon 22 between rollers 26 and 27. This sag is then removed by the take-up reel 32, again tensioning the ribbon 22. On the upward movement of the hammer 34 to its home position after a printing operation has occurred, roller 26, in moving in an upward direction, will pull new ribbon 22 from the supply reel 21 (FIG. 3), so that a fresh printing area of the ribbon 22 is adjacent the hammer 34. The roller 33 mounted on the one-way clutch 20 (FIG. 1) will prevent the ribbon 22 from moving from the take-up reel 32 towards the supply reel 21 during the upward movement of the roller 26. As shown by the arrow in FIG. 1, the one-way clutch 20 conditions the roller 33 to be rotated in a clockwise direction only. Thus the ribbon 22 is advanced after the hammer 34 has been operated. If the hammer 34 is to be again operated, the ribbon 22 will be in position for a new printing operation.

Assuming that print hammer 35 will now be operated, the downward movement of hammer 35 and the roller 29 will pull the ribbon 22 from the supply reel 21, thus positioning new ribbon 22 under the hammer 35 for the printing of a solid pattern 37 (FIG. 4) on the tag. Upon the return movement of the hammer 35 to its home position (FIG. 5), the upward movement of the roller 29 will create a sag in the ribbon 22 which will be eliminated by the action of the take-up reel 32. It will be seen by mounting the one-way clutch 20 on the roller 33 that the downward movement of roller 29 will pull ribbon 22 from the supply reel 21 rather than the take-up reel 32.

If the hammer 35 is again actuated, the downward movement of the roller 29 will again move the ribbon 22 to allow the printing (FIG. 6) of a second solid pattern 37. Upon the return movement (FIG. 7) of the hammer 35 to its home position, the sag created by the upward movement of roller 29 will be eliminated by the take-up reel 32. If hammer 34 is now actuated (FIG. 8), the downward movement of roller 26 will create a sag in the ribbon 22 which will be eliminated by the take-up reel 32. After the printing of the striped pattern 36 has occurred, the hammer 34 and the roller 26 will be moved in an upward direction allowing the roller 26 to pull a new ribbon 22 (FIG. 9) from the supply reel 21, thus conditioning the printer for a subsequent printing operation. The length of feed of the ribbon 22 from the supply reel 21 by the movement of the rollers 26 and 29 is controlled by the distance between the rollers 27 and 28. Thus by shortening the distance between the rollers 27 and 28, the length of feed of the ribbon 22 will be shortened. It will thus be seen by this construction that fresh portions of the ribbon 22 will always be positioned by the movement of either of the hammers 34,35 to allow the hammers 34,35 to be actuated in any sequence of operation. It is obvious that the system of rollers 26 to 29 inclusive can be mounted between the supply reel 21 and the hammers 34, 35 and still function in the same manner as described previously. While two printing hammers 34,35 are disclosed in the present embodiment, the ribbon indexing mechanism disclosed herein will function in the same manner with one print hammer.

While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in form and detail may be made therein without departing from the sphere and scope of the invention.

Claims

What is claimed is:

1. A mechanism for indexing a printing ribbon past a print station during a printing operation, the mechanism including

a. a source of printing ribbon;

b. means engaging said printing ribbon for tensioning said printing ribbon;

c. a unidirectional drive means engaging said printing ribbon;

d. a pair of stationary roller members engaging said printing ribbon between said source and said tensioning means;

e. a first roller member engaging said printing ribbon and positioned adjacent said stationary roller members, said first roller member mounted for reciprocal movement between said source and said tensioning means;

f. and first means engaging said first roller member for reciprocally moving said first roller member during a printing operation whereby said first roller member is first moved in a direction away from said stationary roller members to produce slack in the printing ribbon which slack is removed by said tensioning means and then moved towards said stationary roller members to position new printing ribbon adjacent the print station.

2. The ribbon indexing mechanism of claim 1 which includes

a. a second roller member engaging said printing ribbon and positioned adjacent said stationary roller members, said second roller member mounted for reciprocal movement between said source of printing ribbon and said tensioning means;

b. and second means engaging said second roller member for reciprocally moving said second roller member during a printing whereby said second roller member is first moved towards said stationary roller members to position new printing ribbon adjacent the print station and then moved away from the stationary roller members to produce slack in the printing ribbon which is removed by said tensioning means.

3. The ribbon indexing mechanism of claim 2 in which said source of printing ribbon includes

a. a supply reel of ribbon; and

b. a slip-clutch engaging said supply reel to provide a drag on the rotation of the supply reel when the ribbon printing is removed from the supply reel.

4. The ribbon indexing mechanism of claim 3 in which said tensioning means includes

a. a take-up reel for the printing ribbon; and

b. means for exerting a constant torque on the take-up reel which is less than the drag of said slip-clutch whereby the take-up reel will be unable to pull printing ribbon from the supply reel.

5. The ribbon indexing mechanism of claim 4 in which said unidirectional drive means includes

a. a rotatably mounted third roller member engaging said printing ribbon;

b. a pair of pressure rollers normally moving the printing ribbon into engagement with said third roller member; and

c. a one-way clutch member engaging said third roller member whereby the third roller member will rotate in only one direction.

6. An apparatus for printing data from a printing ribbon including

a. a supply reel of printing ribbon;

b. means for continually tensioning said printing ribbon including a take-up reel;

c. unidirectional drive means engaging the printing ribbon for releasing the printing ribbon for movement in a direction only from the supply reel to the take-up reel;

d. a first print hammer slidably mounted for movement to a printing engagement with the printing ribbon;

e. a pair of stationary rollers engaging said printing ribbon and positioned downstream from said first print hammer; and

f. a first roller member mounted on said first print hammer and positioned downstream of said first print hammer and upstream of said stationary rollers whereby upon movement of said first print hammer to a printing engagement with the printing ribbon, the first roller member is moved in a direction to create a sag in the printing ribbon which sag is eliminated by said tensioning means and upon movement of the first print hammer to a home position, said first roller member is moved towards said stationary rollers to position new printing ribbon adjacent said first print hammer.

7. The printing apparatus of claim 6 which includes

a. a second print hammer slidably mounted for movement to a printing engagement with the printing ribbon; and

b. a second roller member mounted on said second print hammer, said second roller member positioned downstream of said stationary rollers, whereby upon movement of the second print hammer to a printing engagement with the printing ribbon, said second roller member is moved toward said stationary rollers thereby positioning new printing ribbon adjacent said second print hammer and upon movement of said second print hammer to a home position, said second roller member is moved in a direction away from the stationary rollers thereby creating a sag in the printing ribbon, which sag is eliminated by said tensioning means.

8. The printing apparatus of claim 7 in which said supply reel of printing ribbon engages a slip clutch which provides a drag on the supply reel during removal of printing ribbon from the supply reel.

9. The printing apparatus of claim 8 in which said tensioning means includes means for exerting a constant torque on the take-up reel which is less than the drag of said slip clutch whereby the take-up reel is unable to pull printing ribbon from the supply reel.

10. The printing apparatus of claim 9 in which said unidirectional drive means includes

a. a rotatably mounted third roller member engaging said printing ribbon;

b. a pair of pressure rollers normally moving the printing ribbon into engagement with said third roller member; and

c. a one-way clutch member engaging said third roller member whereby the third roller member will rotate in one direction only.