Sealed cassette for moist facsimile recording paper

Abstract

A disposable cassette fits in a facsimile recorder with a moving electrode which yieldingly opposes a blade electrode and traverses the blade as electrical signals mark an electrolytic recording web. A supply roll of the moist electrolytic recording paper confined in the cartridge is drawn at very low speed along a passage between the moving and blade electrode. A resilient member in the cassette displaces the paper from contact with the blade electrode except where the moving electrode opposes the blade electrode.

Description

BACKGROUND OF THE INVENTION

In electrolytic recorders for facsimile or like graphic recording of electric signals marking current is passed through a moist electrolytic paper or web drawn between a linear or blade electrode at one side of the paper and a second electrode on the other side of the paper which effectively moves along the linear blade. As the paper is advanced it is marked line by line by electric signals applied to the electrodes as metal ions migrate from the recording edge of the blade to the paper and form a colored lake with the paper impregnant.

Good continued recording is dependent on maintenance of moist electrolyte in the paper and on freedom of the blade electrode from irregularities at its recording edge or random accumulation of lake deposits. If the paper dries out it is unable to induce ionic lake deposition from the blade. On the other hand continued contact of stationary or very slow moving moist paper on the blade between recording periods may result in random formation of lake concentrations along the blade due to stray currents. When recording is resumed these concentrations streak along the paper marring the recording. The streaking problem is particularly severe in very slow speed recording in which the paper is fed at a few inches per hour as in ceilometers, compared with high speed recording at inches per minute.

The object of the present invention is to overcome the streaking problem and also avoid drying of moist electrolytic paper.

STATEMENT OF INVENTION

According to the invention an electric graphic recording cassette detachably fitting a recorder having a scanning electrode cooperating with a linear electrode in a recording zone, comprises a housing forming a moist recording web supply compartment and an exit path for the web through the recording zone, the housing having an opening at the recording zone admitting the scanning electrode thereto, and a resilient member at said opening positioned to engage a recording web and yieldingly displace the web from the recording zone. Further the housing contains a supply of moist electrolytic recording web in the compartment and path, the resilient member being biased to displace the web toward the scanning electrode opening out of contact with the linear electrode except where the scanning electrode presses the web against the linear electrode. By displacing the moist paper from the linear electrode lake formation is prevented. Also the resilient displacing member seals the paper compartment from the exit and thereby prevents drying of the electrolyte.

DRAWINGS

FIG. 1 is a side elevation of a facsimile recorder receiving a cassette according to the invention partly broken away;

FIG. 2 is an enlarged fragmentary view of the cassette of FIG. 1; and

FIG. 3 is a side elevation of an alternative form of cassette.

DESCRIPTION

Shown in FIGS. 1 and 2 is a facsimile recorder similar to that more fully described in U.S. Pat. No. 3,545,004, to Milton Alden and comprising a base 1, to which a cover 2 is hinged at 3. Attached to the cover 2 is a linear electrode or blade 4 opposed to a helical electrode 6 curved around a drum 8 as disclosed in U.S. Pat. No. 3,577,150 to Milton Alden which is incorporated herein by reference. Such a helical electrode comprises a folded, serrated strip of thin flexible stainless steel, for example, which yieldingly presses against the blade 4, and the drum about which it is curved is journalled on a support 11 on the base 2. The blade 4 may be in the form of a moving loop as shown in U.S. Pat. No. 2,621,999.

The base 2 forms a cradle 12 receiving a cassette 20 of formed plastic which includes a closed tubular compartment 21 enclosing a roll of moist electrolytic recording paper 22. Extending integrally from the paper compartment 21 is a flat tube 23 whose walls surround a path for the paper to an exit 24 for the paper 22 from the cassette. On its path through the flat tube 23 the paper 22 passes through a recording zone Z between the blade 4 and helical electrode 6 which respectively enter the tube through an upper opening 27 and a lower opening 28. Beyond the cassette exit 24 the paper strip is drawn by rolls 26 and fed out of the base 2 through an exit slit 29.

As shown in detail in FIG. 2, around the opposed edges of the upper opening 27 are wrapped two rubber sheets 15 which seal the opening when the blade is inserted between them. Inside the lower opening 28 a pair of flexible Teflon shields 25 are attached to the flat tube 23. As described in U.S. Pat. No. 3,611,424 to Milton Alden, the shields narrow the recording zone and limit the paper area which might contact the helix 6. The shields also tend to lift the paper, but in any case the resilient upward thrust of the helical electrode 6 urges the paper toward the blade 4. Between recordings and at very low paper speeds pressing of the paper against the lower recording edge of the blade 4 tends to permit stray currents to cause random migration of lake forming ions to the line contact between the paper and blade. During recording random lake concentrations at the blade edge deposit on the paper in elongate unwanted streaks. To obviate this streaking problem a flexible insulating member 30 is attached to the inner wall of the flat tube 23 adjacent to the upper opening 27 for the blade. The free flexing end 31 of the member is biased to extend through the recording zone Z and yieldingly displace the paper 22 out away from the blade and out of the recording zone except at the recording spot where the helical electrode 6 is opposed to the blade 4. As the helical electrode traverses the blade it presses a travelling wave or ridge 22* of paper against the blade only at the effective recording spot. As shown in FIG. 2 the outside edge of the paper 22 (double lines) as viewed from the side travels on straight lines from the left shield 25 to the insulating member 30 and thence to the right hand shield 25, but inwardly from the double line edge of the paper 22, where the helical electrode 6 opposes the linear electrode 4 at an effective recording spot, the upper surface of the paper is shown raised in the ridge 22 by and conforming to the helical electrode 6. This travelling paper wave 22* is so small with respect to the full recording edge of the blade that stray current have negligible effect in producing unwanted ion formation. In addition to preventing unwanted ion formation the displacing member also cooperates with the helix left hand shield 25, and paper 22 to form a barrier to the escape of moisture from the tubular paper compartment 21 and the adjacent flat tube portion 23 surrounding the paper path, the paper 22 bridging the gap between the left hand shield 25 and the insulating member 30, 31 substantially across the lower opening 28.

In FIG. 3 the blade electrode 41 is mounted within a dome 42 integral with the cassette 20, and the displacing member comprises a block 43 of sponge rubber. The shields 25 of FIGS. 1 and 2 are omitted; other elements of the cassette 20 are the same as in FIGS. 1 and 2. The sponge rubber displacer cooperates with the helical electrode 6 as does the Teflon spring of FIGS. 1 and 2 to separate the paper and blade and seal the cassette between recordings, while allowing the helical electrode 6 to press the paper against the blade during recording.

Thus it will be understood that the present disclosure is for the purpose of illustration only and that this invention includes all modifications and equivalents which fall within the scope of the appended claims.

Claims

I claim:

1. An electric graphic recording cassette detachably fitting a recorder having a scanning electrode cooperating with a linear electrode in a recording zone, the cassette comprising:

a housing including a moist recording web supply compartment and guide means forming an exit path for the web through the recording zone, the housing having an opening at the recording zone admitting the scanning electrode thereto, and the guide means including means urging the web toward the opening and into the recording zone, and

a resilient member extending along the recording zone and having a free flexing end closely adjacent the zone and biased yieldingly to displace the web out of the recording zone away from the linear electrode, the scanning electrode resiliently urging the web into contact with the linear electrode against the yielding displacement of the resilient member only at the effective recording spot where the scanning electrode opposes the linear electrode.

2. A cassette according to claim 1 wherein the housing contains a supply of moist electrolytic recording web in the compartment and path, the resilient member being biased to displace the web toward the scanning electrode opening out of contact with the linear electrode.

3. A cassette according to claim 1 including an elongate aperture admitting the linear electrode into the housing and elastomeric means on opposed edges of the aperture cooperating with the linear electrode to seal the opening.

4. An electric graphic recorder for marking a recording web comprising:

a base,

means on the base for holding a supply of recording web,

feed means for drawing the web through the recording zone,

means for guiding the web on a path through the zone, the guide means including means urging the web toward the opening and into the recording zone,

a linear electrode and a scanning electrode on opposite sides of the web at the recording zone cooperating to mark the web, and

a resilient member extending along the recording zone and having a free flexing and closely adjacent the zone and biased yieldingly to displace the web out of the recording zone away from the linear electrode, the scanning electrode resiliently urging the web into contact with the linear electrode against the yielding displacement of the resilient member only at the effective recording spot where the scanning electrode opposes the linear electrode.