Stuffed Ribbon Cartridge

Abstract

A shroud is positioned near the exit area of a stuffed ribbon cartridge for a typewriter or similar machine to prevent more than one strand of a ribbon from being withdrawn from the storage chamber of the cartridge at a time. The shroud is a ridge on the floor of the storage chamber with the distance from the top of the ridge to the ceiling less than the width of the ribbon. The shroud is formed around the exit area in an arc shaped so that the single strand of ribbon being withdrawn from the storage chamber will cross the shroud substantially at right angles to the shroud from any direction that it is pulled from inside the storage chamber.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to stuffed ribbon cartridges and more particularly to an improved stuffed ribbon cartridge for machines such as typewriters.

2. Description of the Prior Art

Typewriter stuffed ribbon cartridges of the type disclosed in the copending U.S. Pat. application Ser. No. 288,830 of Samuel D. Cappotto et al., filed Sept. 13, 1972, provide a new way for quickly changing the ribbon in a typewriter without ever having to manipulate or touch the ribbon. Projections positioned along the walls of the exit ramp prevent the flow of convolutions of ribbon from the storage chamber. However, because of the widely varying coefficients of friction of typewriter ribbon even from the same supplier, sometimes the exiting strand of ribbon will drag convolutions of ribbon along with it into the exit area. If enough convolutions of ribbon are dragged into the exit area, the exit area can become clogged. Because of the increased tension on the ribbon caused by the clogged exit area, the ribbon can break or become frayed along its heat-sealed top edge and break later. Using eight yards of ribbon instead of the maximum capacity of ten yards to decrease the pressure in the storage chamber does not eliminate clogging completely.

SUMMARY OF THE INVENTION

It is, therefore, a primary object of the invention to provide an improved stuffed ribbon cartridge for a ribbon in which the ribbon cannot clog the exit from the storage chamber.

Another object of the invention is to provide a stuffed ribbon cartridge for a ribbon in accordance with the foregoing object in which the ribbon will not break.

Another object of the invention is to provide a stuffed ribbon cartridge for a ribbon in accordance with the foregoing objects in which the ribbon will not fray.

Another object of the invention is to provide a stuffed ribbon cartridge for a ribbon in accordance with the foregoing objects capable of using all kinds of ribbons such as ribbons having widely varying coefficients of friction, widely varying kinds and amounts of ink, and widely varying kinds and qualities of material.

Another object of the invention is to provide a stuffed ribbon cartridge for a ribbon in accordance with the foregoing objects capable of storing a maximum length of the ribbon.

Another object of the invention is to provide a stuffed ribbon cartridge for a ribbon in accordance with the foregoing objects in which a single strand of the ribbon will always exit from the storage chamber with very little disturbance of other portions of the ribbon in the storage chamber.

Another object of the invention is to provide a stuffed ribbon cartridge for a ribbon having an exit shroud in accordance with the foregoing objects in which a single strand of the ribbon will always exit from the storage chamber substantially radial to or at right angles to the shroud.

In order to accomplish the objects of the invention, a shroud is positioned near the exit area of the cartridge. The shroud is a ridge on the floor of the storage chamber. The distance from the top of the shroud to the ceiling of the storage chamber is less than the width of the ribbon so that only one strand of the ribbon will be withdrawn from the storage chamber at a time. The shroud is formed around the exit roller in an arc shaped so that the single strand of ribbon being withdrawn from the storage chamber will cross the shroud substantially at right angles to the shroud from any direction that it is pulled from inside the storage chamber so that none of the ribbon remaining in the storage chamber will be greatly disturbed. Convolutions of ribbon in the storage chamber remain poised in an arc around the shroud. Stuffed ribbon cartridges incorporating the invention have used ribbons with high coefficients of friction and the maximum length of ten yards of ribbon without clogging the exit areas and without fraying.

Other objects and a fuller understanding of the invention can be had by referring to the description and claims taken in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a perspective view, partially broken away, of a stuffed ribbon cartridge embodying the invention.

FIG. 2 is a detail view of the cartridge of FIG. 1 with the ribbon extended around the exit roller.

FIG. 3 is a section view taken substantially along with line 3 -- 3 in FIG. 2.

FIG. 4 is a section view taken substantially along the line 4 -- 4 in FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT

With reference to FIG. 1 of the drawing, the invention is shown embodied in a stuffed ribbon cartridge for a machine such as a typewriter. The typewriter is not shown except for part of a cartridge support 10 and part of a feed mechanism 12. The feed mechanism 12 has a gear 14 for interaction with the cartridge as hereinafter described.

The cartridge is of the type disclosed in the copending U.S. Pat. application Ser. No. 288,830 of Samuel D. Cappotto et al., filed Sept. 13, 1972. The cartridge has an arm 16 for guiding an endless loop of ribbon 18 toward a print point, which is not shown, of the typewriter. The arm 16 is connected to a housing 20.

The housing 20 includes a base 22 and a cover 24 connected to the base 22. A platform 26 is mounted on the base 22 to provide a storage chamber, indicated generally at 28, for the ribbon 18. The platform 26 has a wall 30 and 32 around most of its periphery to confine the ribbon 18 in the storage chamber 28. The inner surface of the platform 26 serves as a floor 34 for the storage chamber 28, and the inner surface of the top of the cover 24 serves as a ceiling 36. The distance between the floor 34 and the ceiling 36 is only slightly greater than the width of the ribbon 18.

The housing 20 also has an entrance area, indicated generally at 38, and an exit area, indicated generally at 40. The entrance area 38 has a knurled feed roller 42 and an integral gear 44 rotatably mounted on the housing 20 with the gear 44 in mesh with the gear 14 of the feed mechanism 12 of the typewriter when the cartridge is in operating position on the support 10 on the typewriter. A knurled idler roller 46 is rotatably mounted on a bell crank 48 that is pivotally mounted on the housing 20. The idler roller 46 is biased in a counterclockwise direction against the feed roller 42 by a spring lever 50 on the bell crank 48. The idler roller 46 squeezes a strand 18a of the ribbon 18 entering the storage chamber 28 from the arm 16 against the feed roller 42.

The exit area 40 has a barrel-shaped exit roller 52 rotatably mounted on a vertical pin 54 on the floor 34 of the platform 26. As shown in FIG. 2, the roller 52 is used to change the direction of a strand 18b of the ribbon 18 being withdrawn from the storage chamber 28. After passing the roller 52, the strand 18b of ribbon 18 traverses an exit ramp, indicated generally at 56, on its way to the arm 16. Projections 58 are formed along the sides of the exit ramp 56 to guide the exiting strand 18b of ribbon 18.

In order to prevent convolutions of ribbon 18 from being pulled out of the storage chamber 28 by the exiting strand 18b ribbon 18, a shroud 60 is formed around the exit roller 52. The shroud 60 is a ridge on the floor 34 of the storage chamber 28. As shown in FIGS. 3 and 4, the distance from the top of the shroud 60 to the ceiling 36 of the storage chamber 28 is less than the width of the ribbon 18. In one embodiment of the invention, the height of the storage chamber 28 is 0.355.+-. 0.010 inch, the height of the shroud 60 is 0.070.+-. 0.005 inch, and the width of the ribbon 18 varies from 0.305 to 0.320 inch. At the worst condition, the distance (0.365 - 0.065 = 0.300 inch) from the top of the shroud 60 to the ceiling 36 of the storage chamber 28 is 0.005 inch less than the minimum width of the ribbon 18. The foregoing dimensions are, of course, only an example, and numerous variations can be used without departing from the invention.

The shroud 60 also has an inclined surface 62 sloping toward the storage chamber 28 at a 20.degree. angle. The angle also is only an example. However, if the angle of the inclined surface 62 is too gradual, the shroud 60 has to be very wide and thus will take up too much space from the storage chamber 28. If the angle is too steep, convolutions of ribbon 18 in the storage chamber 28 will be too tightly packed around the shroud 60. It is best to have a moderate angle so that each convolution of ribbon 18 will find its own level on the shroud 60 and not all of them will be at the same level. As shown in FIGS. 1 and 2, the shroud 60 is formed around the exit roller 52 in an arc shaped so that the strand 18b of ribbon 18 being withdrawn from the storage chamber 28 will cross the shroud 60 substantially radial to or at right angles to the shroud 60 no matter what direction it is pulled from inside the storage chamber 28 so that none of the ribbon 18 remaining in the storage chamber 28 will be greatly disturbed.

In operation, with the cartridge in operating position on the support 10 on the typewriter, the gear 44 of the feed roller 42 is in mesh with the gear 14 of the feed mechansim 12 of the typewriter as shown in FIG. 1. After each impact at the print point of a type character, not shown, the feed roller 42 pulls the strand 18a of ribbon 18 one character width from the arm 16 and stuffs the strand 18a, of ribbon 18 into the storage chamber 28 of the housing 20. The strand 18a of ribbon 18 forms the convolutions of ribbon 18 in the storage chamber 28. The convolutions of ribbon 18 form an arcuate front with the crest of the arc pointing toward the exit area 40.

At the same time that the strand 18a of ribbon 18 is being fed into the storage chamber 28 from the arm 16, the strand 18b of ribbon 18 is being pulled from the storage chamber 28 to the arm 16 at the exit area 40. The strand 18b of ribbon 18 is pulled across the shroud 60 substantially radial to or at right angles to the shroud 60 no matter what direction it is pulled from inside the storage chamber 28. Since the strand 18b of ribbon 18 crosses the shroud 60 substantially at right angles to the shroud 60, the convolutions of ribbon 18 remaining in the storage chamber 28 are only slightly disturbed by the withdrawal of the strand 18b of ribbon 18. In crossing the shroud 60, the strand 18b of ribbon 18 might collapse to conform to the cross section of the shroud 60 as shown in FIG. 3 or might warp or tilt slightly. Since the convolutions of ribbon 18 remaining in the storage chamber 28 have no tensile pull to cross the shroud 60 and the frictional force of the exiting strand 18b of ribbon 18 is insufficient to pull them across the shroud 60, they remain poised in an arc around the shroud 60, each finding its own level on the inclined surface 62 of the shroud 60. Tests conducted using cartridges with the shroud 60 have shown very favorable results. The cartridges have used ribbons 18 with high coefficients of friction and the maximum length of ten yards of ribbon 18 without clogging the exit area 40 and without fraying.

Although the invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made by way of example and that numerous changes in the details of construction and the combination and arrangement of parts can be resorted to without departing from the spirit and the scope of the invention.

Claims

Having thus set forth the nature of the invention, what is claimed is:

1. An improved stuffed ribbon cartridge for a ribbon, the cartridge having a storage chamber for the ribbon with a floor and a ceiling substantially perpendicular to and farther apart than the width of the ribbon and an exit area for a single strand of the ribbon to exit from the storage chamber, wherein the improvement comprises a shroud on the floor of the storage chamber near the exit area and an inclined surface on the shroud rising from the floor toward the exit area until the distance from the top of the shroud to the ceiling of the storage chamber is slightly less than the width of the ribbon to restrain all but the single strand of ribbon from being fed from the storage chamber.

2. The cartridge of claim 1 in which the inclined surface on the shroud rises from the floor of the storage chamber toward the exit area at a substantially uniform angle.

3. The cartridge of claim 2 in which the shroud is formed in an arc near the exit area.

4. The cartridge of claim 3 in which the shroud is formed around the exit area in an arc shaped so that the single strand of ribbon being fed from the storage chamber will cross the shroud substantially at right angles to the shroud from substantially any direction that the single strand of ribbon is pulled from inside the storage chamber.

5. The cartridge of claim 4 in which the exit area includes a roller to change the direction of the single strand of ribbon exiting from the storage chamber and the shroud is formed around the roller.

6. The cartridge of claim 5 in which the cartridge has an entrance area for the ribbon to enter the storage chamber and a feed roller near the entrance area to stuff the ribbon into the storage chamber.

7. An improved stuffed ribbon cartridge for a ribbon, the cartridge having a storage chamber for the ribbon and an exit area for a single strand of the ribbon to exit from the storage chamber, wherein the improvement comprises a shroud formed in an arc near the exit area for confining the width of the ribbon to a space less than the width of the ribbon to restrain all but the single strand of ribbon from being fed from the storage chamber.

8. The cartridge of claim 7 in which the storage chamber has two substantially parallel surfaces greater than a ribbon's width apart to confine the ribbon in the storage chamber with the width of the ribbon substantially perpendicular to the surfaces, and the shroud is a ridge on one of the surfaces with the distance from the top of the ridge to the other surface less than the width of the ribbon.

9. The cartridge of claim 8 in which the shroud has an inclined surface extending from one of the surfaces of the storage chamber toward the storage area.

10. The cartridge of claim 9 in which the shroud is formed around the exit area in an arc shaped so that the single strand of ribbon being fed from the storage chamber will cross the shroud substantially at right angles to the shroud from substantially any direction that the single strand of ribbon is pulled from inside the storage chamber.

11. The cartridge of claim 10 in which the exit area includes a roller to change the direction of the single strand of ribbon exiting from the storage chamber and the shroud is formed around the roller.

12. The cartridge of claim 11 in which the cartridge has an entrance area for the ribbon to enter the storage chamber and a feed roller near the entrance area to stuff the ribbon into the storage chamber.