Automatic paper feeder

An automatic paper feeder for use with a character printer, the feeder having a dual cartridge capability and, alternatively, the capability of feeding envelopes to the printer. The feeder is constructed so that cut sheets or envelopes leaving the printer are delivered to a receiving station in a first in-first out arrangement. The dual cartridges are adapted to contain the cut sheets and either one or both of the cartridges can be inserted in the feeder for any given run. When both cut sheet cartridges are used the first and second sheets of a two page letter, for example, can be sequentially printed. Simultaneous use of both cartridges also permits sheets of different size and/or weight to be programmed into the feeder. In addition to cut sheets and envelopes, the feeder of the invention can be utilized for feeding continuous forms or the feeder can be deactivated to permit printing on a single "pre-empt" sheet. The feeder is provided with an outer sound minimizing housing that encloses both the feeder and the character printer.

BACKGROUND OF THE INVENTION 
This invention relates generally to word processing equipment, and has 
particular reference to a novel automatic paper feeder for use with known 
types of character printers. 
Automatic paper or sheet feeding attachments for character printers are 
presently available from a number of manufacturers. Originally, these 
auxiliary paper feeders provided for a single cartridge or cassette 
containing a stack of cut sheets of paper that were fed into the printer a 
sheet at a time. 
Single cartridge paper feeders were followed by feeders having a dual 
cartridge capability whereby the first and second sheets of a two page 
letter, for example, can be sequentially printed. Dual cartridge feeders 
also permit sheets of different size and/or weight to be programmed into 
the feeder if desired. Dual cartridge feeders as described are the feeders 
that are the most widely used with character printers at the present time. 
In addition to paper feeders having single and dual cartridges for cut 
sheets, feeders have been developed for envelopes and other feeders have 
been developed for feeding continuous forms to a printer, the latter being 
known as pin or tractor feeders. In spite of these different capabilities, 
a single feeder capable of effectively performing all of them has not been 
developed heretofore to the best of applicants' knowledge. There exists a 
need for such a feeder in view of the growing use and importance of word 
processing equipment. 
SUMMARY OF THE INVENTION 
The automatic paper feeder of the present invention is adapted to feed to a 
character printer cut sheets from either one or both of a pair of cut 
sheet cartridges or, alternatively, to feed envelopes to the printer from 
a special envelope cartridge. For each cartridge there are roller and 
guide means for successively delivering single sheets or envelopes to the 
printer. Paper leaving the printer after having been printed upon is 
guided by the feeder to a receiving or stacking station, the feeder being 
constructed so that the paper is delivered to the station in a first 
in-first out arrangement. 
When both cut sheet cartridges are employed, the feeder can be programmed 
so that the first and second sheets of a two page letter, for example, can 
be sequentially printed. Use of both of the cut sheet cartridges also 
permits sheets of different size and/or weight to be programmed into the 
feeder. 
The paper feeder disclosed herein also includes an interface unit which may 
have incorporated therein a pin or tractor feed assembly that can be 
utilized for printing on continuous forms. In addition, the feeder can be 
deactivated to permit printing on a single "pre-empt" sheet if required. 
To minimize the sound of the printer and feeder to an acceptable level, 
the feeder is provided with an outer, foam lined housing that encloses 
both units.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring now to the drawings, and with particular reference to FIGS. 1-3, 
the automatic paper feeder of the invention is comprised of three main 
parts which are the paper cartridge-paper guide unit generally indicated 
at 15, FIGS. 2 and 3, the interface unit generally indicated at 16 and the 
outer, sound minimizing housing 17 shown in FIG. 1 and in phantom lines in 
FIG. 2. The housing 17 is not essential to the operation of the feeder but 
is a very desirable feature. The paper cartridge-paper guide unit 15, 
hereinafter usually referred to as the cartridge-guide unit, is rockably 
mounted on the interface unit 16 in a manner to be described hereinafter. 
The interface unit is in turn mounted on the character printer (not shown) 
and is constructed so that it can be readily attached to any of the 
presently most widely used printers. 
The cartridge-guide unit 15 includes left and right side plates 18 and 20 
secured together by suitable structural members, not shown. The unit 15 is 
arranged so that it can accommodate a pair of cut paper containing 
cartridges, 21,22 as shown in FIG. 4 or, in the alternative, an envelope 
containing cartridge 24 as shown in FIG. 5. Means to be described are 
provided in the cartridge-guide unit 15 and interface unit 16 to guide a 
sheet of paper or an envelope to the printer platen shown in phantom lines 
at 25, and other means to be described are provided for guiding the paper 
leaving the platen to a receiving station 26, FIGS. 1-5, on the cartridge 
guide-unit 15. Throughout the specification and claims, it is intended 
that the generic term "paper" include cut or single sheets, envelopes and 
continuous forms. 
As shown in FIG. 4, the upper and lower cut paper cartridges 21 and 22 are 
received in a cartridge cradle assembly 27 rockably mounted in the 
cartridge-guide unit 15 in a manner to be described. The upper paper 
cartridge 21 is supported in the cradle assembly by a pair of guideways 28 
and the lower paper cartridge 22 is supported by guideways 29. These 
guideways also guide the cartridges as they are inserted into or removed 
from the unit 15 through an access opening 30, FIG. 3, in the left side 
plate 18 thereof. The outer housing 17 is provided on its left side with a 
hinged door (not shown) giving access to the opening 30. 
Upper and lower paper cartridges 21,22 are identical in construction and 
reference is made to FIG. 8 illustrating an upper cartridge 21 with its 
hinged lid 31 in raised position. The cartridge is formed with flanges 32 
at opposite lower edges which flanges are received in the guideways 28 as 
shown in FIG. 4. A bottom opening 34 adjacent one side of the cartridge 
permits the bottom sheet of a stack of sheets loaded into the cartridge to 
be engaged by a scrub roll to be described. The upper and lower cartridges 
can accommodate sheets ranging in size from 5.5".times.5.5" up to 
14".times.14", and slidable guide bars 35,36 are provided in the interior 
of the cartridge for engaging and keeping in alignment the side and bottom 
edges of a stack of sheets of a particular size. Adjustable guide bars as 
shown are well known in the art. 
When the paper feeder is to feed envelopes rather than cut paper, the paper 
cartridges 21 and 22 are removed and an envelope containing cartridge 24 
as shown in FIGS. 5 and 9 is substituted. Cartridge 24 is provided with 
opposite lower edge flanges 37 that are received in guideways 38 in the 
cartridge guide unit 15. The envelope cartridge is formed with a front 
opening 40 through which the front envelope of a vertical stack can be 
engaged by a scrub roll to be described. The envelope engaged by the scrub 
roll is ejected from the cartridge through a narrow top opening 41. Top 
opening 41 is restricted by an appropriate plastic flexure beam 200 acting 
as a variable width throat to provide for the varying thickness of an 
envelope, and to prevent multiple feeding. The envelopes in a stack are 
biased into engagement with the scrub roll by a movable vertical plate 42 
and compression spring 43. 
Referring to FIG. 4, the scrub roll for the upper paper cartridge 21 is 
shown at 44 and the scrub roll for the lower paper cartridge 22 at 45. The 
upper scrub roll 44 also serves as the scrub roll for the envelope 
cartridge 24 as shown in FIG. 5. The scrub rolls are driven by a stepping 
motor 46, FIG. 2, a pulley 47 on the motor shaft driving scrub roller 
clutches 48,50 through a timing belt 51. 
When, under program control, a sheet of paper is to be fed from the upper 
paper cartridge 21, FIG. 4, the scrub roll 44 feeds the lowermost sheet in 
the stack 52 into a paper guide assembly comprising a first pair of guide 
plates 54 and 55, a pair of guide rollers 56,57 and a second pair of guide 
plates 58,60. The plates 58,60 guide the sheet between guide rollers (not 
shown) in the interface unit 16 and from thence into the nip of the usual 
idler rollers 61 at the rear of the platen. 
When a sheet of paper is to be fed from the lower cartridge 22, FIG. 4, the 
scrub roll 45 for that cartridge feeds the lowermost sheet in the stack 62 
into a paper guide assembly comprised of the guide plates 58,60. From 
plates 58,60 the paper follows the same path as paper from the upper 
cartridge 21., i.e., between rollers in the interface unit 16 and then 
into the nip of the idler rollers 61. It should be noted that the cut 
paper in the lower cartridge 22 may differ from that of upper cartridge 21 
in size and/or weight, and further that the feeder can be programmed to 
feed from these cartridges alternately as, for example, in printing the 
first and second sheets of a two page letter. 
When an envelope is to be fed from the envelope cartridge 24, FIG. 5, the 
upper cartridge scrub roll 44 feeds the front envelope of the vertical 
stack of envelopes 64 up through the top opening 41 and into a paper guide 
assembly comprising short and long guide plates 65,66 and two pairs of 
guide rollers 67,68 and 70,71. From rollers 70,71, the long guide plate 66 
guides the envelope between rollers 56,57 and from thence the envelope 
follows the same path as a sheet of paper into the nip of the idler 
rollers 61. 
In the above described paper guide assemblies for upper and lower paper 
cartridges 21,22 and envelope cartridge 24, the rollers 56,67 and 70 are 
driven and rollers 57,68 and 71 are idlers. Referring to FIG. 2, wherein 
the driven pulley 50 for the lower scrub roller 45 is shown, it can be 
seen that the pulley 50 in turn drives an auxiliary pulley 72 by means of 
a timing belt 74. The pulley 72 is fixed on a shaft 75 that extends across 
the cartridge-guide unit to the opposite or left side thereof where a 
second pulley 76, FIG. 3, is fixed on the shaft. Pulley 76 is connected by 
a timing belt 77 to the guide rollers 56,67 and 70 whereby the latter are 
driven in synchronism with the scrub roll 44 or 45. To this end, the belt 
77 is also in operable engagement with a pulley 78 secured to the left end 
of the shaft for the upper scrub roll 44. 
After a sheet of paper from the upper or lower paper cartridge 21 or 22 or 
an envelope from the envelope cartridge 24 has been rolled around the 
printer platen 25, FIGS. 4 and 5, and the printing has been completed, the 
printer rolls the sheet or envelope clear of the platen and into still 
another paper guide assembly that takes the paper to the receiving station 
26 at the top of the feeder. The guide assembly for paper leaving the 
platen comprises three pairs of guide plates 80, 81; 82,83 and 85,86, and 
five pairs of guide rollers, the rollers in each pair having the reference 
numbers 87 and 88. In each pair of guide rollers, the rollers 87 are 
driven and rollers 88 are idlers. 
When the paper emerges from the third pair of guide plates 85,86, it is fed 
by a continuous belt 90 to the receiving station 26. Belt 90 passes around 
a drive roller 92 and a series of idler rollers 93,94,95,96 and 97. The 
belt also passes around and drives a larger idler roller 98 that has a 
serrated or toothed surface as shown. Idler rollers 96 and 98 extend 
between and are supported by upstanding bracket members 100 at the 
opposite sides of the cartridge-guide unit and the terminal roller 97 
extends between and is supported by a pair of arms 101 that are pivotally 
connected to the bracket members on the axis of roller 96. 
Paper leaving guide plates 85,86 is picked up by belt 90 and passes under 
idler rollers 93 and 94, around idler 98 and under idler 97 as indicated 
in FIG. 4. This roller arrangement turns the sheet of paper over, the 
sheet passing between plates 85,86 with its printed side up and being 
turned over as it passes around rollers 94 and 98 whereby it is delivered 
to the receiving station 26 with its printed side down. This results in 
the desired first in-first out arrangement or sequence because after a 
particular run of sheets has passed through the feeder and is stacked as 
shown, the stack as a whole is picked up and turned over and the sheets 
are then arranged in the same order that they were fed into the machine. 
As shown in FIGS. 1, 4 and 5, the receiving station is provided with an 
adjustably positioned guide plate 102 of conventional construction to keep 
the stacked sheets in vertical alignment. 
When the paper feeder is to process envelopes, the roller 97 and its 
supporting arms 101 are rotated upwardly to the position shown in FIG. 5. 
The roller assembly thus has one position for paper sheets and another for 
envelopes, and the supporting arms are releasably held in one or the other 
of these positions by a spring biased detent 104 that enters one of two 
indentations 105. A transversely extending hood 106, FIGS. 1, 2 and 5, is 
operably connected to roller 97 and arms 101 and rotates with them between 
the sheet feeding position shown in FIGS. 1 and 2 and the envelope feeding 
position of FIG. 5. 
As with sheets of paper, envelopes pass between the guide plates 85,86 with 
their printed side up. The envelopes are oriented with their long 
dimension crosswise to the feeder and as they leave guide plates 86,86 
they are picked up by belt 90 and pass under idler rollers 93,94 and then 
around idler roller 98. Each envelope is moved upwardly by roller 98 until 
its upper edge engages a lip on spring 107, FIG. 5, at the forward edge of 
the tipped up hood 106. This stops the upward movement of the envelope but 
the serrated roller 98 continues rotating and positively carries the lower 
edge of the envelope forward and down whereby the envelope is positioned 
at the back of the stack 108 of envelopes as shown. This transitional 
movement of the envelope is indicated by the phantom lines 110 in FIG. 5. 
The envelopes in the stack 108 are positioned with their printed sides 
facing forwardly and, as will be apparent, in the first in-first out 
arrangement that is desired. The roller assembly in envelope feeding 
position also operates to stack the envelopes vertically which enables 
many more envelopes to be processed than if they were to be stacked 
horizontally. 
The drive means for the driven rollers of the above-described paper guide 
assembly, extending from the exit side of the printer platen 25 to the 
receiving station 26, are as follows. The platens of most character 
printers include a gear (not shown) adjacent one end thereof which gear is 
utilized for driving the pin or tractor feed. When the interface unit 16, 
FIG. 2, of the invention is mounted on the printer, a gear 110 in the unit 
meshes with the platen tractor gear and operates through a train of gears 
111,112 in the unit to drive a gear 114 on the shaft of the driven guide 
rollers 87, FIGS. 4 and 5. Gear 114, mounted on a one way bearing, is 
connected by a timing belt 115, FIG. 3, to the next driven guide roller 87 
above it and the latter is connected by another timing belt 116, FIG. 2, 
to the next two driven rollers 87. With this arrangement all of these 
guide rollers 87 are driven in synchronism with the printer platen as it 
rolls paper around the platen and up into the guide assembly. 
From FIG. 3 it can be seen that the upper right roller 87 engaged by the 
timing belt 116 of FIG. 2 is also engaged by a generally horizontally 
extending belt 117 that passes around the final guide roller 87 in the 
series and the driven roller 92, FIGS. 3 and 4. As previously noted, 
roller 92 drives the continuous belt 90 which in turn drives the idler 
rollers 93,94,95,96 and 97. The belt 117 is driven by a D.C. motor 118, 
FIGS. 3 and 4. This motor is inactive as the paper is advancing around the 
printer platen but when the trail-edge of the paper is sensed by a photo 
detector 120 located just above the platen, FIGS. 4 and 5, the printer 
becomes inactive and the motor 118 becomes active and finishes feeding the 
paper to the receiving station 26. 
Having reference now to FIGS. 4 and 6, it was noted above that the 
cartridge cradle assembly 27 in which the paper and envelope cartridges 
are received is rockably mounted in the cartridge-guide unit 15. The 
reason for this is to permit the cartridges and paper therein to be rocked 
out of engagement with the scrub rolls 44 and 45, the rocking movement 
being clockwise in FIG. 4 and counterclockwise in FIG. 6. If this were not 
done, the insertion of full cartridges into the feeder would cause the 
exposed bottom sheets thereof to be wrinkled or torn by the scrub rolls 
and these sheets could thereafter jam the feeder. 
FIG. 6 shows in solid lines the cartridge cradle assembly 27 in operative 
engagement with the scrub rolls. The phantom lines illustrate the cradle 
assembly after it has been rocked out of engagement with the scrub rolls, 
the clearance between permitting full cartridges to be inserted into or 
removed from the assembly without damaging the exposed paper. The cradle 
assembly is rocked on a pivot 121 by an eccentric element 122 that 
operates in an opening 124 in the lower portion of the cradle assembly. 
The eccentric element can be turned to effect the rocking by means of a 
suitable handle not shown. 
Referring now to FIGS. 2 and 7, the interface unit 16 is positioned on the 
top of the character printer and is secured thereto by latch elements 125 
that hook under the platen shaft 126 adjacent the ends thereof. The unit 
16 includes an adjustable foot 127 on each side to level the unit, and 
thus the feeder, as necessary. The paper feeder disclosed herein is 
particularly adapted for use with Qume, Diablo and NEC character printers 
and the interface unit may be adapted as necessary to fit these and other 
printers, the construction of the cartridge-guide unit 15 always being the 
same. Normally, after the interface unit 16 has been mounted on a printer 
it is not removed except for repairs to the printer. 
The cartridge-guide unit 15 is mounted on the interface unit 16, FIGS. 2 
and 7, so that it can be tipped or rocked back out of operative engagement 
therewith as shown in phantom lines in FIG. 7. In such position, the 
feeder is inactive and there is no driving connection between the printer 
and cartridge-guide unit because gear 114 for the lowermost guide roller 
87 is out of engagement with the gear train 110,111 and 112 in the 
interface unit. The cartridge-guide unit pivots on a shaft 128 in the 
interface unit and is normally held in operative engagement therewith by a 
pair of latch elements 129, the lower hook ends of which engage the 
opposite ends of a shaft 130 in the interface unit. 
The cartridge-guide unit 15 is rocked back out of engagement with the 
interface unit when the latter is equipped to process continuous forms by 
the printer. The pin or tractor feed for such forms which is optional is 
shown at 131 in FIG. 4. The feed units 131 are themselves conventional as 
is the manner in which the forms are passed around the printer platen. The 
pin feed units are slidably mounted on a round shaft 132 and square shaft 
134, both being part of the interface unit. The shaft 134 is the drive 
shaft and is driven by gear 112 in the interface unit. 
In addition to processing continuous forms, the cartridge-guide unit 15 may 
be rocked back out of engagement with the interface unit to permit 
printing on a single sheet in what can be called a "pre-empt" use. To hold 
the unit in its rocked back position a conventional slide and thumbscrew 
device 135-136 is provided, FIGS. 2, 3 and 7. 
With reference to FIG. 1, the outer housing 17 has an inner lining 137 of 
foam rubber or the like and this plus the fact that the housing encloses 
the printer as well as the feeder greatly reduces the noise of operation. 
The housing is provided with a top hinged front door 138 for access to the 
printer and feeder. 
The cartridge-guide unit 15 includes a shelf member 140, FIGS. 2-7, for 
supporting printed circuit boards (not shown) or the like. As shown in 
FIGS. 2 and 3, the various idler rollers in the paper guide assemblies are 
urged into engagement with their corresponding driven rollers by springs 
141 mounted on the left and right side plates 18 and 20. As also shown in 
these Figures, one-way bearing caps 142 are provided for the driven 
rollers. 
In operation, paper from one of the cartridges selected under program 
control is fed to the nip of the idler rollers at the rear of the printer 
platen. This provides registration relative to the platen. A command is 
then sent to the printer to roll the paper around the platen and position 
it to be checked by a photo sensor (not shown) for proper registration. If 
the form is properly registered against the photo sensor, a command is 
issued to the printer to register the form for printing on line one. 
Control at this time is turned over to the host system and the paper 
feeder becomes inactive. 
When printing is complete, the system sends an ASCII Form Feed character 
with a Character Strobe or energizes a Top of Form line or other 
appropriate means. The feeder, even though inactive during printing, 
monitors the data lines and when a Form Feed Character is detected, 
monitors printer activity. When execution is complete in the printer, the 
feeder inhibits further commands from the host system and assumes control 
of the printer. The feeder issues a command to the printer to roll the 
form clear of the printer platen. The feeder then feeds the forms to the 
receiving station where it is stacked face down in a first in-first out 
manner. A new form is then inserted in the manner previously described. 
From the foregoing description, it will be apparent that the invention 
disclosed herein provides a novel and very versatile paper feeder for use 
with a character printer. As will be understood by those familiar with the 
art, the invention may be embodied in other specific forms without 
departing from the spirit or essential characteristics thereof.