GB2104046A - Loading ink ribbons into cartridges - Google Patents

Abstract

An unfilled but otherwise assembled cassette containing a leader ribbon is provided for subsequent filling with an inked ribbon. The cassette is adapted to fit a printhead or platform of a needle or a daisy-wheel or a golfball printer or the like. It has a ribbon inlet 14 and a ribbon outlet 16 communicating with an otherwise closed chamber 24 to be packed with ribbon in serpentine manner. The short length of leader ribbon is threaded between the inlet and outlet along the intended inked ribbon path with exposed flying ends A, B for attachment of the inked ribbon or the leader may be a loop which is cut to expose flying ends. The ink- impregnated ribbon is joined to the leader ribbon protruding from the inlet opening 14 e.g. by stapling, heat welding or sewing, the leader ribbon is then withdrawn from the outlet opening 16 until a short length of ink- impregnated ribbon protrudes therefrom, inked ribbon is then fed into the cassette by means of a stuffing machine until it is filled, and the exposed length of inked ribbon between the inlet and outlet is then joined to form an endless loop. <IMAGE>

Description

SPECIFICATION Unfilled tape cassette The present invention relates to an assembled unfilled cassette for printer ribbon and to a method of completing it.

Traditionally typewriters have used fabric ribbons which are wound from reel to reel. With golf-ball typewriters and more recently needle and daisy wheel printers and the like there has been a tendency to enclose the ribbon in a disposable cartridge or cassette. Such cassettes are injection moulded in a plastics material and have an inlet to and an outlet from an otherwise closed chamber in which an inked textile ribbon is stuffed in serpentine manner so that the chamber is tightly packed. Ribbon may be pulled out through the outlet of the chamber and may be returned into the chamber by means of a ribbon transport roller in the chamber adjacent to the inlet which bears upon either an idler roller or a pressure plate so as frictionally to engage ribbon travelling passed it.A formation on an accessible portion of the transport roller (which is normallyjournalled in the upper and lower halves of the cassette) engages in a rotary drive member on the printhead or platform or the like so that the ribbon is advanced stepwise as the characters are printed. Guides may extend for the inlet and outlet (though not all cassettes have them) and the free ends of the ribbon are joined to form an endless loop.

The present practice is for the parts of the cassette to be made first and sold in pieces to a ribbon manufacturer who assembles the component parts, threads the ribbon through the body or pan of the cassette, places the lid on and holds it in place while the internal cavity is being stuffed with ribbon, after which the lid is assembled to the body, e.g. by pin fixing. The free ends of the ribbon are then joined together, e.g. by ultrasonic butt welding. But this is a timeconsuming operation because individual pieces of the cassette have to be unpacked, identified, assembled and the cassette threaded manually, then it has to be stuffed with ribbon and finally the ribbon has to be butt welded. This is a labourintensive process for the ribbon manufacturer who also has to invest in the necessary machinery.It is an object of the invention to provide an unfilled cartridge system that is simpler from the standpoint of the ribbon manufacturer.

This invention is based on the realization that it is advantageous to make available unfilled cassettes in fully assembled condition, utilising a short length of messenger ribbon (which could also be described as a leader") being threaded between the inlet and the outlet of the cassette with exposed flying ends or with an exposed loop that may be cut by the user to define flying ends.

Another aspect of the invention provides a method of making an inked tape cassette which comprises threading a short length of messenger ribbon through the body of the cassette so that flying portions protrude through inlet and outlet openings in the body, assembling the lid of the cassette to the body, joining the ink-impregnated ribbon to the messenger ribbon protruding from the inlet opening, withdrawing the messenger ribbon from the outlet opening until a short length of ink-impregnated ribbon protrudes therefrom, winding ribbon into the cassette until it is filled and joining the exposed lengths of ribbon between the inlet and outlet to form an endless loop.

It is preferred that the messenger ribbon be of a visibly distinct colour to the ink-impregnated ribbon and it may conveniently be white.

An embodiment of the invention will now be described by way of example only with reference to the accompanying drawings, Figure 1 of which is apartly cut away plan view of an inked fabric ribbon cassette in its unfilled state with a messenger ribbon threaded through and Figure 2 of which shows the cartridge with flying ends of messenger ribbon.

In the Figure 1 a body or pan 10 of a ribbon cassette is injection moulded in a plastics material and has a peripheral wall 12 formed with an inlet opening 14 and an outlet opening 1 6. A short length of messenger ribbon 1 9 from the inlet 14 is threaded between a ribbon transport roller and a spring where it passes into the ribbon space 24 and an opposed spring which imposes a tension on ribbon leaving the cavity and thence through outlet 1 6. In the form as sold the messenger ribbon may take the form of a continuous loop, but it is cut to define flying ends A and B (Figure 2) of the messenger ribbon that protrude from respective openings 1 4 and 1 6. The lid 20 is assembled to the body or pan of the cassette in conventional manner and the cassette is supplied to ribbon manufacturers as such with the ribbon transport system already in place and with the messenger ribbon (typically a woven tape white in colour or of any other flexible material) already threaded through the cassette.

The ribbon manufacturer attaches the leading end of the inked ribbon to the flying end A of the messenger ribbon and places the cassette in a ribbon stuffing machine. The attachment may be made mechanically, e.g. by a staple, by heatwelding, or by sewing or by any other method. But preferably a strip adhesive having a latex base compatible with the solvents in the ribbon ink is placed latex face down on the uninked messenger ribbon and the cover paper is removed exposing the adhesive which then readily accepts the inked ribbon. This is particularly important because the leading edge of the inked ribbon must be held firmly down so that no threads can catch on projections within the cassette. The stuffing machine is driven to draw the flying end a of the messenger ribbon slowly through the cassette, the operator pulling the end B of the messenger ribbon through until inked ribbon protrudes form the outlet 1 6. Then the stuffing machine is driven at high speed to fill the cavity 24 with an appropriate length of inked tape. The resulting filled cartridge now has flying ends of inked ribbon protruding from openings 14 and 16 and these are butt-welded together to define an endless band.

Claims (8)

1. An unfilled assembled cassette for subsequent filling with an inked ribbon and adapted to fit a printhead or platform of a needle or a daisy-wheel or a golf-ball printer or the like, said cassette having a ribbon inlet and a ribbon outlet communicating with an otherwise closed chamber to be packed with ribbon in serpentine manner, a short length of messenger or leader ribbon threaded between the inlet and outlet along the intended inked ribbon path for attachment of the eventual inked ribbon.

2. A cassette according to Claim 1 wherein the leader ribbon has a visually distinct colour from the eventual inked ribbon.

3. A cassette according to Claim 2 wherein the leader ribbon is coloured white.

4. A cassette according to Claim 1 wherein the messenger ribbon is in the form of a continuous loop.

5. A cassette according to Claim 1 wherein the messenger ribbon is in the form of a tape with flying ends.

6. A method of making an inked tape cassette which comprises threading a short length of messenger ribbon through the body of the cassette so that flying portions protrude through inlet and outlet openings in the body, assembling the lid of the cassette to the body, joining the inkimpregnated ribbon to the messenger ribbon protruding from the inlet opening. withdrawing the messenger ribbon from the outlet opening until a short length of ink-impregnated ribbon protrudes therefrom, winding ribbon into the cassette until it is filled and joining the exposed lengths of ribbon between the inlet and outlet to form an endless loop.

7. An unfilled assembled cassette for subsequent filling with an inked ribbon and adapted to fit a printhead or platform of a needle or a daisy-wheel or a golf-ball printer or the like, substantially as hereinbefore described with reference to the accompanying drawings.

8. A method of making an inked tape cassette substantially as hereinbefore described with reference to the accompanying drawings.