U.S. patent number 3,834,507 [Application Number 05/327,945] was granted by the patent office on 1974-09-10 for printing apparatus.
This patent grant is currently assigned to Kroy Industries Inc.. Invention is credited to Franklin C. Bradshaw.
United States Patent |
3,834,507 |
Bradshaw |
September 10, 1974 |
PRINTING APPARATUS
Abstract
A printing apparatus of the type having an image carrier, a
color carrier, a font with a plurality of raised, selectively
positionable characters, and a piston assembly whereby activation
of the piston assembly causes an image to be transferred from the
color carrier to the image carrier. The printing apparatus further
includes backspace means for compensating for letter interlock.
Inventors: |
Bradshaw; Franklin C. (St.
Paul, MN) |
Assignee: |
Kroy Industries Inc.
(Stillwater, MN)
|
Family
ID: |
23278780 |
Appl.
No.: |
05/327,945 |
Filed: |
January 30, 1973 |
Current U.S.
Class: |
400/134.6;
400/308; 400/615.2; 400/613 |
Current CPC
Class: |
B41J
3/38 (20130101) |
Current International
Class: |
B41J
3/00 (20060101); B41J 3/38 (20060101); B41j
001/30 () |
Field of
Search: |
;197/6.3-6.7,18,49,53,82,84R,84A,84B,91 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Pulfrey; Robert E.
Assistant Examiner: Rader; R. T.
Attorney, Agent or Firm: Dorsey, Marquart, Windhorst, West
& Halladay
Claims
I claim:
1. A printing apparatus having means for providing proper spacing
between the printed characters of certain two character
combinations whose spacing appears visually improper because of the
comparative shape of such characters when positioned adjacent to
each other comprising:
a printing station;
an image carrier;
a font having a plurality of raised characters, each selectively
positionable in alignment with said printing station to thereby
define an aligned character;
means for causing an image of said aligned character to be
transferred to said image carrier;
means for guiding said image carrier between said aligned character
and said printing station and for advancing said image carrier
relative to said printing station subsequent to each transfer of an
image of said aligned character to said image carrier;
backspace means for causing the selective rearward movement of said
image carrier a specified distance relative to said printing
station, such rearward movement occurring subsequent to the
printing of the first character of certain two character
combinations and prior to the printing of the second character of
such two character combinations and said specified distance
corresponding to the distance necessary to provide proper spacing
between the characters of said certain two character
combinations.
2. The printing apparatus of claim 1 wherein said backspace means
includes first and second elongated members pivotally connected to
each other at one end for limited relative pivotal movement, each
of said first and second elongated members including means for
gripping said image carrier upon said limited relative pivotal
movement.
3. The printing apparatus of claim 2 wherein the connection between
said first and second elongated members is such that subsequent to
said limited relative pivotal movement, further movement of said
first and second elongated members results in corresponding
movement of said image carrier.
4. The printing apparatus of claim 3 having means for moving said
first and second elongated members.
5. The printing apparatus of claim 4 wherein said means for moving
said first and second elongated members includes a slide member
adapted for reciprocal movement and having an elongated slot
transversely disposed with respect to the direction of reciprocal
movement of said slide member.
6. The printing apparatus of claim 5 wherein said means for moving
said first and second elongated members includes a pin connected
with said first and second elongated members and extending through
said elongated slot.
7. The printing apparatus of claim 6 wherein said pin is securely
fastened to one of said first and second elongated members and
associated with the other for limited movement relative
thereto.
8. The printing apparatus of claim 7 having means for limiting the
movement of said first and second elongated members, the extent to
which said movement is limited being dependent upon the size of the
characters on said font.
Description
BACKGROUND AND SUMMARY OF THE INVENTION
The present invention relates generally to the field of lettering
and printing equipment and more specifically to a printing
apparatus designed for high quality, appropriately spaced printing
of characters onto an image carrier with means for compensating for
letter interlocking.
In the past, lettering such as that appearing on engineering
drawings and the like has been hand lettered either by free hand or
through the use of mechanical lettering aids such as those commonly
identified by the trademark "LeROY" and manufactured by Kueffel
& Esser Company of Morristown, New Jersey. Because it was
desired that this lettering be uniform and of high quality, the
skill of a trained draftsman was, of course, required. As a result
these conventional methods were quite expensive, not only because
of the skilled draftsman which was necessary, but also because such
lettering when done free hand or with the use of lettering aids was
quite time consuming. Thus, there was, and still is, a real need
for a printing apparatus which can be used to accomplish the high
quality, appropriately spaced lettering desired for engineering
drawings and the like and which can be used by a relatively
unskilled operator.
One of the features which such an apparatus must have in order to
be acceptable is a means for adjusting the position of the printing
surface to compensate for letter interlocking. Letter interlocking,
as it is referred to in the present application is the ability of
certain letter combinations to interlock or appear improperly
spaced because of the particular shape of such letters. For
example, the letters "A" and "V" or "A" and "W" if printed as
adjacent characters would appear improperly spaced if no letter
interlocking adjustment is made. The apparatus of the present
invention provides means for physically moving the print media or
surface to compensate for such letter interlocking when such an
adjustment is necessary. Further, the apparatus of the present
invention provides means for adjusting the amount which such print
media is moved relative to the size of the characters being
printed. These and other accomplishments of the present invention
will become apparent with reference to the description of the
preferred embodiment, the drawings, and the appended claims.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the exterior features of the
lettering apparatus of the present invention.
FIG. 2 is a top perspective view of the lettering apparatus of the
present invention.
FIG. 3 is a perspective, exploded view of the internal elements of
the present invention.
FIG. 4 is a plan view showing, among other things, the travel of
the image carrier through the apparatus and the means for advancing
the image carrier during the printing cycle.
FIG. 5 is a plan view showing the travel of, among other things,
the color carrier through the apparatus and the means for advancing
the color carrier during the printing cycle.
FIG. 6 is a close-up view, partially in section, of the means for
advancing the image carrier.
FIG. 7 is a close-up view of the means for compensating for letter
interlocking.
FIG. 8 is a close-up view, partially in section, of a portion of
the means for varying the force propelling the piston head upwardly
toward the raised character in proportion to the square area of the
character being printed.
FIG. 9 is a plan view of one side of the cam assembly.
FIG. 10 is a front view of the cam assembly.
FIG. 11 is a close-up view, partially in section, of the means for
activating the printing cycle and insuring proper alignment of the
raised character prior to activation.
FIG. 12 is a plan view of the font.
FIG. 13 is a side view, partially in section, of the font.
FIG. 14 is a view, partially in section, of the piston assembly and
a portion of the means for varying the force propelling the piston
head toward the raised character.
FIG. 15 is a view, partially in section, of the piston
assembly.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference first to FIGS. 1 and 2, the printing or lettering
apparatus of the present invention includes an external shell 8
covering the frame of the apparatus which is not specifically shown
but which is disposed throughout the apparatus for supporting the
shell 8 and various shafts, slides, springs and other elements of
the apparatus as will hereinafter be described.
Generally, a font 36 (individually illustrated in FIGS. 12 and 13)
is positioned on the shell 8, as shown, by means which permit the
font 36 to be free spinning or freely rotatable about a center
shaft 13 extending upwardly from the surface of the shell 8. As
shown in FIGS. 12 and 13, a plurality of raised characters 27 are
disposed on the underside of the font 36 near its periphery so that
as the font 36 is rotated about the shaft 13, the characters 27
pass a printing station 55 (FIGS. 1 and 2) positioned immediately
above a piston assembly. A font retainer 9 adapted for limited
slideable movement relative to the shell 8 is positioned such that
a portion of the retainer 9 extends over the periphery of the font
36 in the area of the printing station 55 to serve as a means
against which the font 36 may be supported during the printing
cycle to oppose the upward movement of a portion of the piston
assembly against the underside of the font 36 and to oppose
movement of the font 36 in response to movement of an alignment
means hereinafter described.
An image carrier or print media and a color carrier or ribbon are
adapted for movement past the printing station 55 at right angles
to each other between the raised character on the underside of the
font 36 and the piston assembly so that when the piston is released
and caused to move upwardly toward the font 36, an image of the
raised character is transferred from the color carrier to the image
carrier. It should also be noted that the image carrier passes the
center of the font 36 during its advancement and printing is done
on a center line of the font 36. As further illustrated in FIGS. 1
and 2, the shell 8 contains a number of external buttons and
selector wheels which control the operation of the lettering
apparatus. In this respect, a print button 28 operates to activate
a motor and commence the printing cycle, a word space button 82
serves to advance the image carrier an appropriate amount between
adjacent words, a lettering spacing selector wheel 63 functions to
adjust the amount of the image carrier which is advanced between
each printed character, a tape advance button 94 operates to
advance the image carrier when relatively large advancement is
desired and to allow proper cut-off length, a letter interlock
button 142 serves to physically backspace the image carrier a
specified amount to obtain proper spacings for certain combinations
of letters and to compensate for letter interlocking, a font size
selector wheel 124 functions to provide for proper ribbon spacing,
letter spacing and letter interlock spacing corresponding to the
character size of a particular font, and the button 83 operates to
cut the image carrier for removal from the apparatus when such is
desired.
The internal elements of the lettering apparatus can be seen best
with reference to FIG. 3. As shown, the apparatus is driven by a
motor 10 having a shaft 12 upon which is mounted an anti-reverse
clutch 11 designed, among other things, to permit revolution of the
clutch, and thus a cam assembly 14 secured to it, in one direction
only. The motor 10 is a conventional skeleton frame motor which, in
the preferred embodiment, is a Model No. PF 4515U121 supplied by
Merkle-Korff Gear Co. of Franklin Park, Illinois. As illustrated,
the clutch 11 is mounted to the shaft 12 and together with a single
revolution clutch assembly 15, serves as a rotatable support for
the cam assembly 14 during the printing cycle. As will be described
in more detail throughout the specification and with reference to
other Figures, the cam assembly 14 has four cam surfaces which,
during a single revolution, drive a piston assembly 49, a means for
advancing the print media and a means for advancing the color
carrier, and serve to insure proper alignment of the character
being printed. The single revolution clutch 15 is a relatively
cylindrical element disposed between the clutch 11 and the cam
assembly 14 and has means designed to limit the cam assembly 14 and
also the motor 10 to single revolution during a printing cycle.
A catch 16 is integrally formed with the clutch 15 and extends
outwardly therefrom for engagement with one end of an elongated
member 18 of a trigger assembly 19. As illustrated, the member 18
is bifurcated at one end for operative engagement with a trigger
stem 20 and a trigger stem connection 21 and is pivotally connected
between its ends at the pivot 22 to the frame of the apparatus. The
end of the member 18 adapted for engagement with the catch 16
includes a cut-out portion 25 designed to fit over the catch 16 and
a latch 24 designed to engage the catch 16 to limit the rotational
movement of the clutch 15 and thus the entire cam assembly 14.
The trigger stem connection 21 which is rigidly secured to the
trigger stem 20 includes a transversely extending pin 26 adapted to
fit between the bifurcated portions of the member 18 for
transferring reciprocal movement of the stem 20 to the member 18,
thereby causing the member 18 to pivot about its pivot 22. The
trigger stem 20 extends upwardly from the connection 21, through
one end of a bracket 29 and is connected with a print button 28 at
its upper end. The bracket 29, is pivotally connected to the frame
of the apparatus at the pivot 30 and has one end operatively
connected with the trigger assembly 19 for transferring reciprocal
movement of the stem 20 to a pair of alignment pins or font locking
pins 31, 31. The reciprocal movement of the stem 20 is transferred
to the bracket 29 by a washer 32 rigidly secured to the stem 20
immediately above the point at which the stem 20 passes through an
elongated opening in the bracket 29. When the button 28 is
depressed the bracket 29 pivots in a counterclockwise direction
about the pivot 30 as a result of engagement with the washer 32. It
should be noted that the opening in the bracket 29 must be
elongated to compensate for the pivotal movement of the bracket 29
and the reciprocal movement of the stem 20.
The other end of the bracket 29 is rigidly connected with a pin
support member 34 which supports a pair of upstanding font locking
pins 31, 31. As illustrated best in FIG. 11, the pair of pins 31,
31 are tapered at their upper ends and are adapted to fit into
corresponding tapered notches 35 in the underside of the printing
font 36 which appropriately positioned to insure proper alignment
of the character to be printed, and thus the font 36, during the
printing cycle. The pins 31, 31 extend through a pair of
conventional spring members 38, 38 which abut a portion of the
apparatus frame 39 and which serve to continuously bias the support
member 34, and thus the pins 31, 31, downwardly as viewed in FIG.
11. This force on the member 34, and thus the bracket 29, opposes
depression of the print button 28 (FIG. 3) A microswitch,
illustrated in FIG. 11 by the reference numeral 40, has a switch
member 41 connected to the pin support member 34 in such a manner
that the upward movement of the support 34 and the pins 31, 31 into
the corresponding notches 35 activates the switch 40 which in turn
activates the motor 10 (FIG. 3). It should be noted that the switch
40 is positioned such that it will be activated only when the pins
31, 31 are fully extended into the notches 35. This insures proper
alignment of the font 36 upon commencement of the printing cycle.
For example, if the font 36 is manually positioned so that the pins
31, 31 engage a portion of the font 36 between the notches 35, the
switch 40, and thus the motor 10 (FIG. 3) will not be activated
when the print button 28 is depressed since the pins 31, 31 will
not have moved a distance sufficient to trigger such activation. If
the font 36 is positioned so that the pins 31, 31, although not
perfectly aligned, have their upper tapered points disposed
anywhere in the notches 35, proper alignment will be achieved as a
result of the wedging action between the opposing tapered surfaces
of the tips of the pins 31, 31 and their respective notches 35 and
the upward movement of the pins 31, 31. For example, if the font
36, as viewed in FIG. 11, were misaligned slightly to the right,
upward movement of the pins 31, 31 upon depression of the print
button 28 would cause the free spinning font 36 to be moved
slightly to the left, thereby achieving proper alignment prior to
commencement of the printing cycle. It should be noted that the
font retainer 9 shown best in FIGS. 1, 2 and 14 has a portion
extending over the periphery of the font 36 to oppose upward
movement of the font 36 and to allow for the above mentioned
wedging action to occur. Thus, it can be seen that the above
discussed elements provide a means for properly aligning the
character to be printed and insuring such proper alignment upon
commencement of the printing cycle.
With general reference to FIG. 3 and specific reference to FIGS. 4,
5, 9 and 10, it can be seen that the cam assembly 14 has four cam
surfaces 42, 45, 48 and 50 which function to drive the apparatus of
the present invention during a single revolution of the cam 14.
First, the cam surface 42, best shown in FIGS. 3 and 4, is located
at the outermost periphery of the assembly 14 and functions to
drive the image carrier advance mechanism. Second, the cam surface
45, best shown in FIGS. 3, 5 and 10, is disposed on one side of the
assembly 14 and drives the color carrier advance mechanism
indicated generally in FIG. 5 by reference numeral 46. Third, the
cam surface 48, which is an interior surface illustrated best in
FIGS. 3, 9, 14 and 15, drives the piston assembly 49. The operation
of each of these surfaces and the elements which they drive will be
described in more detail later in the specification.
Finally, the cam surface 50, illustrated best in FIGS. 3 and 4,
comprises a partially cylindrical surface and serves to lock the
trigger assembly 19 out and the font locking pins 31, 31 in during
the printing cycle. For example, when the print button 28 is
depressed, the trigger stem 20 and connection 21 are moved
downwardly causing the member 18 to pivot about its pivot 22 to
release the latch 24 from the catch 16. Simultaneously, the
downward movement of the stem 20 causes the washer 32 to engage and
pivot the bracket 29 about the pivot 30, thereby causing upward
movement of the pins 31, 31 into the notches 35 and the activation
of the switch 40 (FIG. 4) to commence the printing cycle.
Activation of the switch 40 in turn causes activation of the motor
10 to rotate the clutch 11 and the cam assembly 14 in a clockwise
direction as indicated. As the cam assembly 14 and thus the cam
surface 50 rotate, the outer surface 50 engages the portion 51 of
the member 18 to keep the trigger assembly 19 and latch 24 open and
the pins 31, 31 locked into the notches 35 (FIG. 11). When the cam
assembly 14 has rotated sufficiently so that the partial
cylindrical surface 50 passes the point 51, the member 18 is caused
to move in a clockwise direction as a result of the force exerted
on the member 34 by the springs 38, 38 which in turn causes the
latch 24 to engage the catch 16 to prevent further movement of the
clutch 15 and the cam assembly 14. It should be noted that the
clutch 15, in addition to including means to limit the movement of
the assembly 14 to a single revolution, also includes an internal
spring means for braking the assembly 14 to prevent a sudden stop
when the latch 24 engages the catch 16.
With general reference to FIG. 3 and specific reference to FIG. 4,
a print media or image carrier in the form of the printing tape 52
is fed from the roll of tape 54, through the means for advancing
the media and past the printing station 55. As illustrated, the
printing station 55 is located immediately above the piston
assembly 49 to enable the printing of a desired character onto the
tape 52 through the cooperative action of the piston assembly 49
and the font 36 in the manner hereinafter described. The roll of
printing tape 54 is rotatably mounted on the center spindle 56 of a
cartridge 58 supported within the frame of the apparatus to allow
the tape 52 to be freely taken from the roll 54.
The means for advancing the print media 52 includes a double crank
lever or motion transfer arm 59 rotatably supported with respect to
the apparatus frame by the shaft 60. One arm of the transfer lever
59 serves to rotatably support a roller 61 adapted for rolling
engagement with the cam surface 42. A second arm of the lever 59 is
anchored via the spring member 62 to the apparatus frame thereby
causing the member 59 to be continuously biased in a clockwise
direction and the roller 61 biased toward engagement with the
surface 42. The third arm of the transfer lever 59 is connected via
the connecting member 64 to one arm of a bellcrank member 65. The
connecting member 64 extends through the end of the third arm of
the lever 59 and into an elongated slot 66 formed in the bellcrank
65 to transfer movement from the lever 59 to the bellcrank 65. The
bellcrank 65 is secured to a spring clutch 69 which in turn is
mounted to a shaft 68 in a manner which permits free rotational
movement of the clutch 69 and thus the bellcrank 65 about the shaft
68 in a clockwise direction, but which grips the shaft 68 and
causes the clutch 69, the bellcrank 65 and the shaft 68 to rotate
in unison when the bellcrank 65 is moved in a counterclockwise
direction.
As shown best in FIG. 6, a drive roller 70 is mounted to the shaft
68 for rotational movement therewith and an idler roller 71 is
disposed immediately above the drive roller 70 in sufficient
proximity thereto to cause the image carrier 52 passing between the
rollers 70 and 71 to move in the direction indicated upon
counterclockwise movement of the drive roller 70. A rubber "O" ring
72 is disposed in a groove on the periphery of the roller 70 to aid
in gripping the print media 52 and advancing it. A letter spacing
arm 74 is connected to a second arm of the bellcrank 65 for
variably advancing the media 52 during the printing cycle. As
illustrated, the spacing arm 74 has a forwardly extending portion
75 adapted for engagement with a notch 76 formed in the letter
spacing ring 77 (FIG. 12) of the font 36 to limit the
counterclockwise movement of the bellcrank 65 and thus similar
movement of the drive roller 70. This in turn limits the
advancement of the image carrier 52 during each printing cycle.
This arrangement provides means for variably advancing the media 52
in accordance with the particular character being printed. For
example, as shown in FIG. 12, the underside of the font 36 includes
a letter spacing ring 77 having a plurality of notches 76 of
different size for controlling the image carrier advance following
the printing of each character. It should be noted that the
particular size of the notch 76 and thus the permissible forward
movement of the spacing arm 74 during the printing of any
particular character will depend upon the character being printed.
For example, the size of notch 76 associated with each of the
letters I and W will be different since the letter I takes less
printing space than the letter W and consequently, the advance of
media following the printing of the I would be less. Thus, the
notch 76 for the letter I is such that it allows less forward
movement of the arm 74 than that for the letter W thus advancing
the print media a lesser amount. Thus, the above discussed elements
afford a means for properly spacing the characters to be printed
despite the amount of printing space required for the various
characters.
With reference to FIGS. 3, 4 and 5, the operation of the means for
advancing the print media 52 may be described as follows: Following
depression of the print button 28, the latch 24 is released from
the catch 16 and the cam assembly 14 is rotated in a clockwise
direction by the motor 10. Because of the tension in the spring
member 62, the roller 61 is caused to roll along the surface 42
during rotation of the cam assembly 14. As the assembly 14 begins
to rotate, the shape of the surface 42 is such that it causes
movement of the lever 59 in a counterclockwise direction,
corresponding clockwise movement of the bellcrank 65 and rearward
movement of the letter spacing arm 74. During this movement, the
shaft 68 and drive wheel 70 do not rotate because of the
orientation of the clutch 69 with respect to the shaft 68. It
should be noted that during this portion of the printing cycle, the
radial distance between the shaft 12 and the point on the surface
41 engaged by the roller 61 is increasing or remaining constant. If
this condition is not met, the media 52 would begin to advance
prior to the printing portion of the printing cycle. At a
preselected point during the printing cycle, the piston assembly 49
is released and the image of the character being printed is
transferred to the media 52. Following this, the surface 42 at the
point engaged by the roller 61 is such that the radial distance
between the shaft 12 and this point is decreasing, thereby allowing
for clockwise movement of the lever 59, counterclockwise movement
of the bellcrank 65 and forward movement of the spacing arm 74 into
engagement with the notch 76. This movement also causes
counterclockwise movement of the shaft 68 and drive wheel 70 and
advancement of the print media 52. Although the surface 42 may have
several operable alternative shapes, it is necessary that the
radial distance between the portion of the surface 42 engaged by
the roller 61 and the shaft 12 prior to or during the printing step
never be decreasing since this would cause advancement of the print
media 52 before or during the printing step, thus resulting in an
inferior or improperly spaced printed character.
As further illustrated in FIG. 3, means is provided in the form of
the eccentric shaft 53 for adjusting the spacing between adjacent
printed characters. As is evident from FIGS. 3 and 4 and from the
description of the means for advancing the image carrier the
distance which the image carrier 52 is advanced between printed
characters is dependent on, among other things, the position of the
axis 60 about which the member 59 rotates relative to the surface
42. For example, the greater the distance which the axis 60 is
spaced from the surface 42, the smaller the counterclockwise
movement during revolution of the assembly 14, and thus, the
smaller the advancement of the media 52. Similarly, positioning the
axis 60 closer to the surface 42 would result in a greater
rotational movement of the member 59 during a printing cycle and
thus greater advancement of the media. Because of the eccentric
shaft 53, one end of which supports the member 59 and the other end
of which is supported by the apparatus frame, the position of the
axis 60 about which the member 59 rotates relative to the cam
surface 42 can be varied by rotation of the shaft 53. As pointed
out above, this in turn varies the advancement of the media between
adjacent characters. Rotation of the shaft 53 is accomplished by
manual rotation of a letter spacing selector wheel 63 which is
operatively connected to the shaft 53 via a plurality of gears 57a
and 57b.
Associated with the shaft 68 as shown in FIG. 3 is a means for
advancing the image carrier 52 (FIG. 4) to provide proper spacing
between printed words. Such means includes a word space lever 78
freely pivotable at one end about the shaft 68 and moveable at its
other end between a stop member 79 and one end of a lever arm 80.
The arm 80 is pivotally connected at its other end 81 to the frame
of the apparatus and is connected between its ends to a word space
button 82 operatively disposed in the apparatus frame. Although not
specifically illustrated in the drawings, the lever arm 80 has a
shoulder portion adapted to engage a portion 84 of a directional
clutch 85 to rotate the clutch 85 in a counterclockwise direction
upon depression of the word space button 82. The clutch 85 is a
conventional directional clutch mounted on the shaft 68 in a manner
which causes the clutch 85 to be freely rotated about the shaft 68
in a clockwise direction, but which grips the shaft 68 and rotates
it therewith when the clutch 85 is moved in a counterclockwise
direction. Thus, depression of the button 82 and consequential
downward movement of the arm 78 and counterclockwise movement of
the clutch 85 causes counterclockwise rotation of the shaft 68 and
drive wheel 70, thereby advancing the print media. As can be seen,
the distance which the media 52 is advanced is directly dependent
upon the permissible downward movement of the arm 78 against the
vertical stop 79. In this respect, means which will be discussed
later is provided for automatically adjusting the vertical position
of the stop 79 in relation to the size of the characters being
printed, thereby providing the proper word spacing for the various
sizes of characters.
Also associated with the shaft 68 and the clutch 85 as illustrated
in FIG. 3 is a means for feeding the print media 52 (FIG. 4) when a
relatively large advancement of the media is desired such as, for
example, when the printing or a particular group of words has been
completed and the media is desired to be advanced for cutting and
removal from the apparatus. This means includes a cammed gear
segment 86 pivotally connected at the pivot 88 to the apparatus
frame and having a plurality of gear teeth 89 adapted to
operatively engage corresponding gear teeth 90 formed in the clutch
85. Disposed against a lower portion of the gear segment 86 is one
end of a spacing linkage 81 which is pivotally mounted to the frame
at the pivot 92 and which is connected at its other end to a tape
feed button 94. Upon depression of the button 94, the linkage 91
moves about the pivot 92 causing upward movement of the segment 86
and corresponding counterclockwise movement of the clutch 85. As
discussed earlier, such movement of the clutch 85 also causes
counterclockwise movement of the shaft 68 and drive wheel 70 and
advancement of the print media 52. A spring member 97 is attached
to the gear segment as shown to bias the segment 86 downwardly and
against depression of the button 94. This also biases the clutch 85
in a clockwise direction against the shoulder of the arm 78 (not
shown) and thus biases the arm 78 upwardly against the end of the
arm 80.
Referring again to FIG. 3 and also to FIG. 5, the color carrier or
ribbon 96 is fed from a ribbon cartridge 98 of conventional design,
past the printing station 55 above and at right angles to the print
media 52, through the means for advancing the ribbon and finally
onto a take-up spool 99. Although not specifically illustrated, the
take-up spool 99 is powered by a conventional stalled synch-motor
such as Model No. GL33RA-46 supplied by Hansen Manufacturing
Company of Princeton, Indiana.
The means for advancing the ribbon 96 during the printing cycle
includes a ribbon advance arm assembly 100 pivotally mounted to the
apparatus frame at the pivot 101 and having a pair of arms 102 and
104 integrally formed with and extending outwardly therefrom. A
roller 105 is rotatably supported by the end of the arm 102 for
engagement with the cam surface 45 of the cam assembly 14. As
illustrated, the surface 45 is such that rotation of the assembly
14 causes reciprocating movement of the arm 100 about the pivot 101
as a result of engagement between the surface 45 and the roller
105. The end of the arm 104 is operatively connected to a clutch
arm 106 by an appropriate connection member 108 for transferring
the reciprocating movement of the arm 100 to the arm 106. Also
connected with the arm 104 is a spring member 107 biasing the
entire advance arm assembly 100 in a counterclockwise direction
about the pivot 101. Integrally formed with the clutch arm 106 is a
conventional directional clutch 109 similar to the clutch 85 used
in the tape advance means (FIGS. 3 and 4). The clutch 109 is
mounted to a shaft 110 in a manner such that it is freely movable
relative to the shaft 110 when moved in a counterclockwise
direction, but such that it grips the shaft 110 and rotates it and
the ribbon drive wheel 111 therewith when it is moved in a
clockwise direction. Similar to the drive wheel 70, the drive wheel
111 includes an "O" ring 112 disposed in a groove about its
periphery which, together with the roller 114, causes the ribbon 96
to be moved in the direction shown in response to clockwise
movement of the wheel 111. When the printing cycle is commenced,
the shape of the surface 45 is such that its engagement with the
roller 105 causes clockwise movement of the arm 100 about the pivot
101. During this movement, the clutch 109 and the clutch arm 106
are moved in a counterclockwise direction. Following release of the
piston, the shape of the portion of the surface 45 engaging the
roller 105 is such that it allows the arm 100 to move in a
counterclockwise direction because of the spring 107, thereby
causing clockwise rotation of the wheel 111 and advancement of the
ribbon 96. Similar to the cam surface 42, the surface 45 may have
several operative alternative shapes. However, it is necessary that
the surface 45 be such that before and during the release of the
piston, the arm is precluded from movement in a counterclockwise
direction. If such condition is not met, the ribbon 96 will be
advanced during the actual printing step, thereby resulting in an
inferior printed character and possible damage to the ribbon 96. It
should also be noted that, for optimum performance, the shape of
the surfaces 42 and 45 and their relation to their respective
operative elements be such that the ribbon is advanced slightly
ahead of the print media. Since the ribbon 96 is quite flimsy
compared to the image carrier 52 (FIG. 4), movement of the media
prior to the ribbon would cause the ribbon to ruffle, thereby
resulting in a smudge on the tape. When the ribbon is moved first,
however, the tension in the ribbon results in a free break away
from the tape. It should be noted that the image carrier or media
52 (FIG. 4) is an adhesive backed printing media of relatively
stiff construction which is capable of receiving an image from the
color carrier 96 (FIG. 5) when the same are disposed between the
raised character of the font and the piston assembly and when the
piston head of the piston assembly is propelled toward the raised
character as hereinafter described.
Extending outwardly from the upper end of the arm 100 is a pin 116
adapted for engagement with a canted stop member 118 to limit the
counterclockwise movement of the arm 100 and thus the advancement
of the ribbon 95. The stop member 118 forms the upper portion of a
ribbon advance adjustment slide 119 which is slideably connected
relative to the apparatus frame and which is biased downwardly by
the spring member 121 connected between the frame and the slide
119. As illustrated, the slide 119 contains an elongated opening
120 which, together with the ribbon spacing adjustment bar 122,
enables adjustment of the vertical position of the slide 119. This
adjustment, in turn, controls the extent to which forward,
counterclockwise movement of the ribbon advance arm 100 is
permitted. As is evident from the drawings, downward adjustment of
the slide 119 permits further counterclockwise movement of the arm
100, while upward adjustment of the slide 119 reduces such
permissible movement. The stop member 79 which limits the downward
pivotal movement of the word space arm 78 is connected with the
upper portion of the slide 119. Thus, adjustment of the vertical
position of the slide 119 also adjusts the vertical position of the
stop 79 to thereby vary the advancement of the media upon
depression of the word space button 82.
As shown best in FIG. 3, the adjustment bar 122 is an elongated
member having one end extending through the opening 120 in the
slide 119 and having its other end operatively associated with a
font size selector wheel 124. The wheel 124 is mounted on a shaft
125 which is journaled at each end by appropriate means to the
apparatus frame. A gear 126 is likewise mounted to the shaft 125
and contains a plurality of gear teeth adapted for engagement with
corresponding gear teeth in a rack 128 integrally formed with the
adjustment bar 122. Through this arrangement, rotation of the wheel
124, and thus the shaft 125 and the gear 126, causes lateral
movement of the bar 122. It should be noted that the bar 122 is
slideably mounted relative to the apparatus frame by appropriate
means to permit such movement.
The end of the bar 122 which extends through the opening 120
includes a generally inclined surface having a plurality of steps
or intermediate levels 129 intended for engagement with the upper
end of the opening 120 to support the slide 119 and oppose the
downward force of the spring 121. Because of the inclined nature of
the end of the bar 122, the vertical position of the slide 119 will
depend upon the lateral position of the bar 122. For example, if
the bar 122 is moved toward the left as viewed in FIG. 3 resulting
from a clockwise movement of the wheel 124, the slide 119 will be
moved upwardly as a result of engagement between the upper end of
the opening 120 and the inclined surface at the end of the bar 122.
The steps 129 in the inclined surface enable definite vertical
positions of the slide to be achieved in response to a particular
setting of the wheel 124. As discussed above, such vertical
adjustment of the slide 119 controls the extent of ribbon advance
and the word space advance of the print media during each printing
cycle. The wheel 124 includes various numerical settings
corresponding to the various sizes of characters normally printed
thereby enabling the operator to properly set the selector wheel to
achieve the correct ribbon advance and word space adjustments.
Referring next again to FIG. 3 and also to FIG. 7, a means adapted
to compensate for letter interlocking is indicated generally by the
reference numeral 130. In the present application, the term letter
interlocking refers to the ability of certain combinations of
adjacent letters to fit together or interlock because of their
particular shape. Because of such interlocking, a space adjustment
is required to make such combinations visually satisfactory. For
example, if the letters A and V or the letters A and W were printed
adjacent to each other without any such adjustment, the space
between such letters would appear to be greater than that between
other letters because of the particular shape of such letters. To
compensate for this, a means 130 is provided for physically moving
the image carrier 52 (FIG. 4) backward an appropriate amount to
compensate for the apparent difference in spacing.
More specifically, as shown best in FIG. 7, the means 130 includes
a first elongated member 131 pivotally connected near its lower end
to the apparatus frame at the pivot 132. The upper end of the
member 131 is connected to the apparatus frame by the floating
pivot 134 which permits limited rotational movement of the member
131 about the pivot 132. A second elongated member or linkage 135
is pivotally connected at one end of the member 131 by the pivot
134 and is connected at its other end to an intermediate portion of
the member 131 by a connecting pin 136 in a manner permitting
limited pivotal movement of the link 135 relative to the member 131
about the pivot 134. The limitation of such movement is
accomplished by an elongated slot indicated by the broken line 138
in the member 131. The upper end of each of the members 131 and 135
have integrally connected thereto, a print media guide 139 and 140
respectively, each of which are designed to guide the advancement
of the media 52. Further, when a letter interlocking adjustment is
necessary, the guides 139 and 140 are adapted to grip the media 52
and move it to the right as viewed in FIG. 7 to compensate for such
letter interlocking.
Associated with the members 131 and 135 is a means for causing
movement of said members in the form of a letter interlock slide
141 which is slideably connected to the apparatus frame by
appropriate slide means and which is connected for vertical,
reciprocal movement in response to the depression and release of a
letter interlock button 142. The movement of the button 142 is
transferred to the slide 141 via the connecting link 144 pivotally
connected to the apparatus frame at the pivot 145. The slide 141
includes an elongated, diagonally disposed slot 146 through which
the pin 136 extends with the slot being disposed such that vertical
movement of the slide 141 causes pivotal movement of the member 135
about the pivot 134. Upon upward movement of the slide 141, the
link 135 is moved in a counterclockwise direction about the pivot
134 relative to the member 131 as a result of the pin 136 being
guided and urged to the right by the lower side of the diagonal
slot 146. During this relative rotational movement between the
members 131 and 135, the guide 140 is moved upwardly toward the
guide 139 until the media 52 is nipped by a portion 148 of the
guide 140 and is gripped between the portion 148 and the guide 139.
When this is accomplished, the rotated position of the link 135 is
such that further upward movement of the slide 141 causes
engagement between the pin 136 and the right hand end of the slot
138 to thereby result in clockwise rotation of the member 131 about
its pivot 132. During this latter movement of the member 131, the
media 52, which has been gripped between the portion 148 and the
guide 139, is moved toward the right, thereby affording proper
spacing between those certain letter combinations for which
adjustment is necessary. It should be noted that the letter
interlocking adjustment is made subsequent to the printing of the
first letter of those various combinations of letters and prior to
the second. For example, when printing the letters AV, the button
142 is depressed and adjustment is made after the letter A is
printed and prior to the printing of the letter V.
It can be seen that the extent to which the media 52 is physically
moved to the right is dependent upon the extent to which the slide
141 is moved upwardly. This, in turn, is dependent upon the extent
to which the button 142 is moved downwardly. As illustrated best in
FIG. 3, the permissible downward movement of the button 142 is
dependent upon the lateral position of an adjustment slide 149. The
slide 149 is slideably connected to the apparatus frame by
appropriate means and includes an inclined surface at one end with
a plurality of steps or levels 150 adapted for engagement with the
link 144 and serving to limit the pivotal movement of the link 144
about its pivot 145. The slide 149 is keyed to the rotation of the
font size selector wheel 124 by a rack 151 integrally formed with
the slide 145 and a corresponding gear 152 secured to the shaft
125. Upon rotation of the selector wheel 124, the lateral position
of the slide 149 and thus the permissible rotational movement of
the link 144 and the extent to which the media 52 (FIG. 11) is
moved rearwardly is adjusted. Because the ribbon advance and the
word space adjustments are also controlled by adjustment of the
wheel 124, the various operative elements by which each of the
ribbon advance, the word space and the letter interlocking is
controlled, are constructed such that for a particular character
size setting of the wheel 124, the proper spacings and advancements
for such character size will be achieved.
Referring generally again to FIG. 3 and more specifically to FIGS.
4, 5, 14 and 15, a piston assembly 49 is positioned immediately
below the printing station 55 and comprises a cylindrical body 154
housing a piston head 155 mounted to one end of a piston stem 158
and a spring member 156 biasing the piston head 155 upwardly. As
best illustrated in FIGS. 14 and 15, the piston stem 158 extends
through and below the cylindrical member 154 and includes a portion
159 at its lower end to which a roller 160 is rotatably mounted.
The roller 160 is designed for rolling engagement with the internal
cam surface 48 shown best in FIGS. 14 and 9.
One end of the spring 156 is disposed against the bottom surface of
the piston head 155 and the other end is supported by a spring
retaining member or cup 162 positioned immediately below the spring
156. The cup 162 is supported at its lower end by a spring lifter
165. During the printing cycle, the stem 158 and piston head 155
are caused to move downwardly in opposition to the force of the
spring 156 as a result of engagement between the roller 160 and the
cam surface 48. When the rotation of the cam assembly 14 is such
that the roller 160 reaches the point 164 of the surface 48 (FIG.
9), the roller 160 is released and the spring 156 which has been
compressed during downward movement of the head 155 expands,
propelling the piston head 155 upwardly toward the raised
characters on the underside of the font 36 thereby transferring the
image of the raised character from the color carrier 96 to the
image carrier 52 disposed immediately below the raised character.
When this is accomplished, the printing step is complete and the
piston assembly elements return to the position illustrated in FIG.
14. As shown in FIGS. 14 and 15, the color carrier 96 and the image
carrier 52 cross at right angles to each other immediately below
the raised character 27 which is aligned with the printing head
155. It should be noted that the image carrier 52 is disposed below
the color carrier 96. Although the printing head 155 may be
composed of a variety of materials, it is important that such
material have a good memory so that impressions of previously
printed characters do not remain in the head and that the material
be softer than the material from which the raised characters on the
font are composed to reduce wear on the font. It should also be
noted that a font retainer 9 is slideably mounted to the frame of
the apparatus with a portion extending over the periphery of the
font 36 to oppose and prevent upward movement of the font 36 as a
result of the piston head 155 being propelled toward the font and
as a result of the alignment pins 31, 31 (FIG. 11) being moved
upwardly into the notches 35.
Associated with the piston assembly 49 is a means for varying the
vertical position of the retaining cup 162 and thus the base
against which the spring member 156 rests. As will be discussed
below, this also varies the upward force of the spring 156 on the
piston head 155 when the piston roller 160 has been released from
the surface 48 and thus the force with which the head 155 is
propelled toward the raised characters 27 of the font 36. In
general, such a means is designed to vary the force urging the head
155 toward the font 36 in proportion to the size or area of the
character being printed. Thus a "period" or a "comma" would be
printed with less force than, for example, the letters M or W. Such
means is necessary to achieve uniform printing of the various
characters.
The means for varying the printing pressure exerted by the piston
head 155 on the raised characters 27 on the font 36 includes a
spring lifter 165 having one end integrally connected to a rack
166, and having its other end extending through an elongated
opening 168 in the cylinder member 154 and engaging a lower portion
of the retaining cup 162. With this arrangement, the vertical
position of the cup 162 is dependent upon the vertical movement of
the lifter 165. Associated with the rack 166 and having teeth
adapted for engagement with corresponding teeth on the rack 166 is
a gear 169 whose rotational movement causes vertical movement of
the rack 166 and the lifter 165. With reference to FIG. 3, the gear
169 is mounted to one end of a shaft 170 whose other end is
connected to a gear 171. The shaft 170 is supported by appropriate
means to the apparatus frame. The gear 171 is operatively connected
via an intermediate gear 172 to a rack 174 mounted for sliding
movement by appropriate slides to the apparatus frame. A character
sensing means in the form of the sensing pin 175 is connected to
the top of the rack 174 as shown best in FIG. 8 and extends above
the surface of the apparatus 176 for engagement with a portion 178
on the underside of the font 36 adapted for engagement with the pin
175 for limiting the lateral movement thereof. This controlled
lateral movement of the pin 175, as a result of the corresponding
operation of the racks 174 and 166 and the gears 172, 171 and 169,
controls the vertical position of the cup 162 and thus the force
with which the head 155 is propelled upwardly toward the font 36
during the printing cycle. For example, referring to FIGS. 14 and
15, if the vertical position of the cup 162 is near the bottom of
the cylindrical member 154, the force by the spring 156 propelling
the piston head 155 upwardly when the roller 160 is released from
the surface 48 is much less than if the vertical position of the
lifter 162 is higher since the spring 156 would not be compressed
as much. It should be noted that the portion 178 (FIG. 8)
corresponds to the pressure control ring 177 (FIG. 12) disposed on
the underside of the font 36 whose particular shape and orientation
relative to the characters on the font is such that the movement of
the pin 175 against the portion 178 as shown in FIG. 8 provides for
the proper vertical positioning of the cup 162, and thus the proper
printing pressure relative to the size or area of the character
being printed. It should be noted that this means varies the
printing force so that it is generally in proportion to the size of
the character printing. Ideally, the force would vary in direct
proportion to the square area of the character printed.
With general reference now to FIG. 3 and more specific reference to
the other figures, the general operation of the lettering apparatus
of the present invention may be understood as follows: First, as
illustrated in FIGS. 1 and 2, the font 36 is manually rotated about
its center support shaft 13 until the character desired to be
printed is positioned in alignment with the printing station 55.
Although exact alignment of the character with the printing station
through this manual rotation is not necessary, it is necessary that
the character be sufficiently aligned so that the font locking pins
31, 31 will engage the tapered notches 35 as shown in FIG. 11.
After the desired character is so aligned, the print button 28 is
depressed causing the member 18 to pivot about the point 22
releasing the catch 16 and causing the font locking pins 31, 31 to
be moved upwardly toward engagement with the tapered notches 35
(FIG. 11) on the underside of the font 36. When the pins 31, 31 are
fully extended into the notches 35, the motor 10 is activated,
causing the cam assembly 14 to rotate about the shaft 12. Such
activation of the motor 10 constitutes the commencement of the
printing cycle. During the initial portion of the printing cycle,
the surface 42 engages the roller 61 in a manner which causes
counterclockwise movement of the member 59 about its axis 60. This
movement, in turn, causes clockwise movement of the bellcrank
member 65 about the shaft 68. During this same initial portion of
the printing cycle, the surface 45 engages the roller 105 to pivot
the assembly 100 in a clockwise direction above the pivot 101. As
illustrated, this movement causes corresponding counterclockwise
movement of the arm 106 and the clutch 109. Also, during this
initial portion of the printing cycle, the surface 48, best
illustrated in FIGS. 9 and 14, engages the roller 160 attached to
the end of the piston stem 158. As the cam assembly 14 and thus the
surface 48 rotate, the engagement between the surface 48 and the
roller 160 causes downward movement of the printing head 155 and
compression of the spring 156.
When the cam assembly 14 has rotated to the point at which the
roller 160 reaches the point 164 of the surface 48 (FIG. 9), the
piston assembly is released, causing the piston head 155, as a
result of the spring 156, to be propelled upwardly toward the
raised character on the underside of the font 36. Because the image
carrier and the color carrier are disposed immediately below the
raised character, an image of the raised character is transferred
from the color carrier to the image carrier. The propelling of the
piston head 155 toward the font 36 is referred to as the printing
step. Following the printing step, the elements of the piston
assembly 49 return to the position illustrated in FIG. 14. Also,
following the printing step, the surfaces 42 and 45 of the cam
assembly 14 are such that clockwise movement of the member 59 and
counterclockwise movement of the assembly 100 are permitted. These
movements, in turn, permit counterclockwise movement of the tape
drive wheel 70 and clockwise movement of the ribbon drive wheel 111
respectively. As described above, the movement of the wheels 70 and
111 cause appropriate advancement of the image carrier and the
color carrier so that the image carrier and color carrier are
appropriately positioned for the next printing cycle.
As also described in the above specification, the preferred
embodiment of the printing apparatus of the present invention
includes a means for variably spacing the characters being printed
in accordance with the space needed to print such characters, a
means for backspacing the image carrier a specified amount to
compensate for the interlocking of certain letter combinations, and
a means for varying the force with which the piston head 155 is
propelled against the raised character on the underside of the font
in direct proportion to the square area of the character being
printed. Finally, means are also provided for advancing the image
carrier to provide proper spacing between words and a means for
adjusting the above features and elements to provide for proper
spacings, advancements and backspacing in accordance with the
particular size of characters being printed.
Although the description of preferred embodiment of the present
invention has been quite specific, it is contemplated that various
modifications may be made to the embodiment disclosed without
deviating from the spirit of the present invention. Consequently,
the scope of the present invention is intended to be dictated by
the appended claims, rather than by the description of the
preferred embodiment.
* * * * *