U.S. patent number 3,890,491 [Application Number 05/457,592] was granted by the patent office on 1975-06-17 for arithmetic unit for a postage meter.
This patent grant is currently assigned to A J M Research Corporation. Invention is credited to Malavazos, administrator, by Gregory A., Arthur J. Malavazos, deceased, Jan Urdal.
United States Patent |
3,890,491 |
Malavazos, deceased , et
al. |
June 17, 1975 |
Arithmetic unit for a postage meter
Abstract
This invention relates to an arithmetic unit for a postage meter
in which the arithmetic and printing mechanism, commonly called
"the meter", is removably attached to a heavy base by easily
removable means, so that the arithmetic printing unit may be
readily separated therefrom and taken to a Post Office for
resetting. The mechanism of the present invention comprises a
hollow cylindrical drive shaft on which is mounted a single
Thomas-type mutilated drum actuator; driven gears slidably, but
non-rotatably mounted on register drive shafts that are arranged on
a concentric arc around the actuator; preferably a second
Thomas-type mutilated drum actuator driven from said drive shaft; a
second plurality of driven gears mounted on register drive shafts
which are concentrically arranged in an arc around said second
actuator; a descending register driven from one of said actuators
and its associated driven gears and register drive shafts;
ascending register driven by said second actuator and its
associated driven gears and register drive shafts; a manually
operated and ordinally arranged selection mechanism to
simultaneously set into each of the orders of the registers driven
by said register drive shafts, the value of the stamp to be
impressed upon the mail matter; and a postage printing mechanism
set by said manually operable selection mechanism and driven by the
drive shaft. Preferably, the means for setting the printing
mechanism comprises a set of first selection bars in the interior
of said hollow drive shaft and set by the manually operated
selection mechanism, and a set of second longitudinal, or axial,
members resting on the exterior of said drive shaft and operable to
set the printing mechanism; and means for interconnecting the
interior and exterior longitudinally movable members.
Inventors: |
Malavazos, deceased; Arthur J.
(late of San Leandro, CA), Malavazos, administrator, by Gregory
A. (San Leandro, CA), Urdal; Jan (San Mateo, CA) |
Assignee: |
A J M Research Corporation
(Hayward, CA)
|
Family
ID: |
23817326 |
Appl.
No.: |
05/457,592 |
Filed: |
April 3, 1974 |
Current U.S.
Class: |
235/101;
235/132R; 235/133R; 101/91 |
Current CPC
Class: |
G07B
17/00193 (20130101); G07B 2017/00233 (20130101); G07B
2017/00548 (20130101); G07B 2017/00241 (20130101) |
Current International
Class: |
G07B
17/00 (20060101); G07g 001/00 (); G06c
007/02 () |
Field of
Search: |
;235/101,132R,133R
;101/91 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Tomsky; Stephen J.
Attorney, Agent or Firm: Wilcox; Robyn
Claims
What is claimed is:
1. An arithmetic and printing unit for a postage meter
comprising:
1. a cylindrical hollow main drive shaft;
2. means for mounting said drive shaft for rotation;
3. means for cyclically rotating said drive shaft;
4. an ascending register and a descending register;
5. a print head mounted on said drive shaft;
6. a manually operative selection mechanism for selecting values to
be registered in said registers and in said print head;
7. a mutilated drum actuator for one of said registers mounted on
said drive shaft;
8. means controlled by said selection mechanism for operating one
of said registers from said actuator differentially from the value
set in said selection mechanism;
9. a second mutilated drum actuator;
10. means driven by said main drive shaft for driving said second
mutilated drum actuator;
11. means controlled by said selection mechanism for registering a
value in said second register from the operation of said second
actuator;
12. value stamping members for printing a stamp value on mail
matter positionably mounted within said print head; and
13. means controlled by said selection mechanism for positioning
said stamping members.
2. The apparatus of claim 1 comprising also means for locking said
value stamping members and said selection mechanism against
adjustment during an initial portion of a cycle of rotation of said
drive shaft, said means comprising:
a. an arm pivotally mounted on said print head;
b. locking means on said arm for engaging the exterior bars;
and
c. means operated during an initial portion of a cycle of operation
of said drive shaft for operating said arm.
3. The apparatus of claim 1 wherein said registers comprise:
1. a plurality of register drive shafts circumferentially arranged
around each of said actuators;
2. 9-tooth selection gears slidably but non-rotatably mounted on
some of said shafts;
3. a tens-transfer gear slidably but non-rotatably mounted on each
of said shafts;
4. a 9-tooth gear rigidly mounted on said shaft;
5. a 40-tooth gear meshing with said last mentioned gear;
6. a 20-tooth gear meshing with said 40-tooth gear;
7. a 10-tooth gear meshing with said 20-tooth gear;
8. a dial rigidly mounted on said 10-tooth gear;
9. a 4-tooth gear and a Geneva wheel mounted on said 40-tooth
gear;
10. a 9-tooth gear and a Geneva wheel rotatably mounted on said
shaft and registering with said 4-tooth gear and said Geneva,
respectively;
11. projecting cam faces in said last-mentioned gear and
Geneva;
12. a cam follower moved longitudinally by said cam projections;
and
13. means moved by said cam follower for moving said tens-transfer
gear of the adjacent higher order into alignment with the single
tens-transfer tooth on said actuator.
Description
BACKGROUND OF THE INVENTION
The present invention relates to the combination of the several
functional elements which comprise what is generally known as a
"Postage Meter". The several elements are described more in detail
in the four applications filed on even date herewith, and is
adapted to be associated with them, namely: (a) one entitled
"Selection Mechanism for a Postage Meter", Ser. No. 457,594; (b) a
second entitled "Register for a Postage Meter", Ser. No. 457,593;
(c) a third entitled "Print Head for a Postage Meter", Ser. No.
457,595; and (d) a fourth entitled "Lock for Selection Mechanisms
and Controls for a Postage Meter", Ser. No. 457,591. In one sense,
these four applications could be considered as divisions of this
application, although it is obvious that they are not legally
such.
Postage meters are made under strict regulations prescribed by the
United States Post Office which require, among other things, that a
value selected for the meter must be accurately set in the value
printing stamp of the meter and actually set into each of the
registers: one in which the values are accumulated known as the
"ascending register", and one in which a value of a stamp is
subtracted from the value set by the Post Office at the time of
payment for postage, known as the "descending register"; a
mechanism which locks the meter against operation while the machine
is printing and operating the registers, so that the amount printed
by the print head and registered in the registers are exactly the
same; and a mechanism which locks the meter against any operation
when the value in the descending register falls below that which
could be set into the machine by an operator. The particular
invention described and claimed herein relates to the combination
of the various essential mechanisms which constitute a postage
meter.
It is well-known in the art that the Post Office with which a meter
is registered will, upon the payment of an amount to cover postage
desired by the user, reset the descending register from time to
time, but the values accumulated in the ascending register are
never changed except by machine operation.
Other requirements of the Post Office are that the meter must be
accurate in all aspects of its operation. It should be ruggedly
constructed to withstand long and hard usage and it must be
relatively trouble-free. It is well-known that a meter is so
encased in its cover that it cannot be repaired and the mechanism
cannot be changed in any way except to change what are known as
"slogan" dies on the print head, and except that the descending
register can have its setting changed at the Post Office when a
Post Office official unlocks access to that register--any other
repair or change in the meter requires that the meter be officially
taken from service by the distributor and repaired in a facility
that is subject to Post Office inspection. Hence, it is essential
for a satisfactory postage meter to be extremely accurate in
registering the values printed by it into both registers as well as
to be rugged and trouble-free in its operation.
It is an object of the present invention to provide an arithmetic
unit, commonly called a Postage Meter for a mailing machine which
can be driven at a speed twice or even more than that commonly used
at present.
It is another object of the present invention to provide a very
rugged and simple construction for a postage meter so that its
operation will be long and trouble-free.
It is a further object of the present invention to provide a
postage meter that is completely accurate in its operation.
It is another object of the present invention to provide a postage
meter that will print larger and more legible stamp designs that is
now possible.
It is still a further object of the present invention to provide a
postage meter in which the printing unit is immediately adjacent
the main bearing of the postage machine, so that there will be less
twisting of the mechanism of the meter than is now possible.
It is still a further object of the present invention to provide an
overall design for a postage meter that is faster and will print
larger stamp indicia than is now possible and which, at the same
time, will be simple and rugged in construction.
It is still a further object of the present invention to provide a
better postage meter than any now available.
These and further objects of the invention will be apparent from
the description of the register in the following specification when
construed in connection with the accompanying drawings in
which:
FIG. 1 is a longitudinal cross-sectional view of the front portion
of the main drive shaft taken along a vertical plane through the
center of the shaft, and showing particularly the mechanism closely
associated therewith.
FIG. 2 is a transverse cross-sectional view of the selection
mechanism taken on a plane perpendicular to the axis of the drive
shaft through the forward part of the selection mechanism, such as
along the plane indicated by the line 2--2 of FIG. 1.
FIG. 3 is a cross-sectional view through the rearward part of the
selection mechanism of the descending register showing the rearward
part of the selection mechanism taken along a plane perpendicular
to the axis of the drive shaft, such as indicated by the lines 3--3
of FIG. 1.
FIG. 4 is a view of the selection locking mechanism taken at the
forward end of the device, such as along the plane indicated by the
line 4--4 of FIG. 1.
FIG. 5 is a view of the back side of the mechanism shown in FIG. 4,
such as taken along the vertical plane indicated by the lines 5--5
of FIG. 1.
FIG. 6 is a cross-sectional view through the drive shaft of the
mechanism, taken on a vertical plane such as that indicated by line
6--6 of FIG. 1.
FIG. 7 is a cross-sectional view through the print head of the
present invention, such as along the vertical plane indicated by
the line 7--7 of FIG. 1.
FIG. 8 is a side view of the print head, such as taken along the
transverse vertical plane indicated by the line 8--8 of FIG. 1;
and
FIG. 9 is a cross-sectional view of the left end of the drive shaft
shown in FIG. 1, showing particularly the mounting of that drive
shaft and is an extension of the drive shaft shown in FIG. 1.
It is well-known that a postage meter, such as the one involved in
the present invention, should be rather light and easily portable,
as it must be taken to the local Post Office from time to time in
order to get it reset so that it may be used for an additional
period of time. The use of postage meters is restricted by the Post
Office to those who have paid postage in advance. The regulations
require that the user must pay for a selected amount of postage at
the local Post Office where the machine is registered, whereupon a
Post Office official will set the descending register in the meter
for that amount of postage. When that amount of postage is
exhausted, the meter must be taken back to the Post Office to be
reset and postage paid thereon. Thus, it is common practice to
divide postal machines into two different devices:
A. A base, which contains the drive mechanism and much of the
auxiliary equipment, such as tape feeding devices, envelope
transporting devices, moisteners, sealers, and particularly the
motor which drives the mechanism. The meter itself is mounted in
the base and the meter and all of the auxiliary equipment is driven
by the power supply in the base.
B. The meter, which should be quite light and easily portable as it
must be taken periodically to the local Post Office. It must have
two registers (one ascending and one descending), a printing
mechanism, and means for setting the register actuating mechanism
and the printing devices. These mechanisms must be so interlocked
that registers receive the exact value that is printed on the
stamp.
This invention relates to the meter per se, and the base will be
mentioned only insofar as it is necessary to support the postage
meter, and to drive it.
The postage meter of the present invention will be enclosed in a
cover (not shown in this application, as it forms no functional
part in the operation of the mechanism contained in the meter). The
cover, or casing, is necessary only to protect the mechanism and
particularly the registers and the stamp printing dies, so that the
register cannot be reset by an unauthorized person or a stamp taken
from the die without operation of the registers.
The meter of the present invention is built around a main drive
shaft 120 (FIGS. 1 and 9). The front end of the drive shaft is
journalled in a suitable bearing 121 in the front of the machine
and in an intermediate bearing 122 affixed to an intermediate
supporting plate 104. The rear end of the drive shaft, or sleeve
(FIG. 9) is keyed to a sleeve 125 that is journalled in a drive
sleeve 130. The hub, or sleeve, 125 is also keyed to a large gear
126 which carries a clutch dog 127 pivotally mounted thereon by a
suitable pivot stud 128. The nose (not shown) on the clutch dog 127
is biased into engagement with a notch 131 formed in the drive
sleeve, or hub, 130 by a suitable spring (not shown). The sleeve
130 is rotatably affixed to the rear frame plate 110 by any
suitable means, such as brackets 132 which are rigidly secured to
the base plate 110 by any suitable means, such as studs 133. These
brackets ride in a peripheral notch 134 formed in the wall of the
drive sleeve 130. The drive sleeve 130 is driven by means of a
bracket, or ear, 135, the bracket 135 being an offset portion of
the drive sleeve 130. The bracket 135 fits into a notch 141 of a
drive disk 140 rotatably mounted in the base by means not pertinent
to the present invention and therefore not shown. An end plate 123
may be rigidly attached to the rear end of the main drive shaft 120
in order to prevent any access to the drive shaft 120 while the
meter is separated from the base. It will be understood that the
disk 140 is driven by a suitable electric motor, likewise not
pertinent to this invention and therefore not shown. It will be
apparent, however, that rotation of the disk 140, one complete
revolution for each cycle of the machine, will rotate the main
drive sleeve 130. Normally the rotation of the drive sleeve 130
will rotate the hub 125 since the nose of the clutch pawl 127 is
engaged in the notch 131 of the drive sleeve except at such time as
the amount standing in the descending register is less than the
maximum amount that could be set into the meter by an operator. The
means for disabling operation of the clutch 127, 131 will be
described hereafter.
It is required by the Post Office that each meter be provided with
two registers: an ascending register in which the total amount of
postage is accumulated from the time it is first placed in service
until it is oficially taken out of service, and is not changed,
even by the Post Office, at any time; and a descending register
which is set from time to time by a Post Office employee in the
local Post Office where the meter is registered, and from which the
value of the stamps set into the meter by its operator is
successively subtracted. In the present invention it is preferred
that the descending register actuator 501 (FIG. 1) be placed on the
main drive shaft 120, which actuator will drive the descending
register 50 in a subtractive direction. Preferably, the ascending
register 60 will be substantially identical with the descending
register but is driven additively by its own actuator 601 (which
preferably is identical to the actuator for the descending
register) but is driven in the reverse direction from the former.
In the preferred form of the invention, this ascending register
actuator 601 and its register 60 are driven from a gear train which
comprises the gear 126 rigidly mounted on the drive shaft 120 and a
gear train which includes the gears 150 and 151, all of which are
pivotally mounted on suitable pivot studs in the rear frame plate
105.
The mechanism of the present invention is mounted in a frame
structure which includes, among other things, a front frame plate
101, intermediate frame plates 102, 104, a rear plate 105, and
auxiliary front plates 107 and 108, all shown in FIG. 1. A fixed
round shaft, or bar, 115 is rigidly supported at its front end in
the front end by the auxiliary plates 107, 108 and at its rear in
the cap, or end plate 123 (FIG. 9). The main drive shaft 120 is a
hollow cylinder surrounding the bar 115 and maintained in proper
spacial relationship with the bar 115 by a series of eleven grooved
disks 367 which primarily serve as intermediate members in setting
a selected value into the printing head, as hereinafter described.
These disks 367 are non-rotatably but slidably mounted on the fixed
bar 115. It will be understood that there are a series of such
grooved disks 367 throughout the length of the drive shaft 120,
therebeing one for each order of the selection mechanism, one for
setting the month of the date stamp, two for setting the days of
the month, and four for setting the various mechanisms which
control the print or non-print operation of the date stamp, the
bulk rate printing slug and two slogan plates.
SELECTION MECHANISM
Each order of the selection mechanism of the present invention is
set by a setting wheel 301 which is rotatably mounted on a stud 302
carried by a plate 303 extending between the front frame plate 101
and the intermediate plate 102. Since operators occasionally let
their hands rest on setting members, it is believed preferable for
it to have a slipping connection with its gear 307, as is more
fully explained in the application entitled "Selection Mechanism
for a Postage Meter".
The gear 307 of each setting wheel 301 meshes with a rack 315 which
is rigidly affixed to a selection bar 320 that is mounted in
suitable bearings carried by the frame plates 101 and 102, for both
longitudinal and rotating movement. Each rack 315 carries a yoke
316 that embraces a slot 513 in a 9-tooth gear 512 mounted on a
square shaft 510, whereby the gear 512 will be differentially set
opposite a selected value tooth on the mutilated drum 501, as more
fully described in the application entitled "Register for a Postage
Meter" above referred to.
The selection bar 320 is provided with a series of ten circular
detent grooves 321 with which is associated a spring ball detent
322 that is resiliently pressed against the bar 320 by a
compression spring 323, the ball and spring being held in a
suitable cylindrical holder, not shown, carried by the frame of the
device. Thus, the bar 320 can be longitudinally adjusted by
rotation of the wheel 301 against the force of spring 323, and once
adjusted, will be resiliently held in that position by the force of
that spring.
It will be understood that there is a setting wheel 301 and an
associated selection bar 320 for each order of the selection
mechanism. In the preferred form of this invention there are four
such setting mechanisms, so that a value of $99.99 may be printed
and set into the register (or a value of $9.99-1/2 in those few
instances in which a user desires a 1/2 mechanism). The bars 320
and setting wheels 301 are angularly placed around the actuator 501
as shown in FIGS. 2 and 3. Since the mechanisms of all of these
selection setting devices are identical, it is believed that only
one need be described.
Rearwardly of the detent grooves 321 on bar 320 is an annular notch
324. The groove 324 is embraced by an ascending register yoke 330
which is rigidly secured to an ascending register setting bar 331.
The forward end of the register bar is provided with a series of
circumferential teeth 332. These teeth mesh with a gear 333 which
is rigidly secured to a check dial 334 mounted on a shaft 335. The
check dial 334 is provided with indicia showing the values from 0
to 9, inclusive, and is visible through a suitable window in the
frame, not shown. The operator can thus determine the value set in
the register by looking at the check dials 334, which, at all
times, will correctly register the value set in the mechanism. No
indicia are required in the setting wheel 301, as that can slip
with respect to the value set in the mechanism and hence it is
preferred that this wheel have no indicia.
The ascending register selection bar 331 is suitably journalled in
the machine for axial, or longitudinal movement, such as in
bearings in the frame plates 104 and 105. Adjacent its rear end,
the bar 331 carries a yoke 335 rigidly secured thereto by any
suitable means, such as a pin, not identified. The outer, or Y, end
of the yoke engages a notch 513 in the hub of a selection gear 512
in the ascending register, which gear, hub and notch are identical
with that previously described in connection with the descending
register 50 and its mutilated drum actuator 501. It will be
understood by those skilled in the art that the gear 512 in the
ascending register will drive the ascending register 60 to
additively enter the same value in that register that is being
subtracted from the descending register 50.
Adjacent the rear end of the main setting bar 320 is a series of
nine circumferential rack teeth 340. As shown in FIG. 1, this
section of the bar has a flattened surface 341. In the drawing, it
would appear that this flattened surface 341 lies at the very top
of the bar in the normal position of the bar. However, in actual
construction, it is preferred that this flattened surface be
slightly off to the side, being placed 107.degree. from the bottom
of the rack key when the bar 320 is in its normal position.
Associated with the rack 340 is a restore cam 342, having a series
of nine projecting cam faces 343 so angled as to restore the
selection bar 320 one tooth, or step, forwardly as a cam face
engages one of the teeth 340. These nine restore cam faces 343 are
so angularly positioned that they trail all of the teeth on the
mutilated drum actuator 501. Hence, after digitation is completed,
the cam 342, 343 will normally restore the bar 320 to its 0
position, one step at a time, before the completion of the cycle of
operation. On the other hand, if the selection bar 320 is rocked
through an angle of 107.degree., the flat 341 will lie opposite the
restore cam disk 342 and its nine camming teeth 343 cannot engage
the teeth of rack 340 so that the bar will not be restored
automatically.
Adjacent the forward end of the main selection bar 320 is a second
series of circumferential rack teeth 350. While the setting bar can
only be moved nine steps to enter a maximum value of nine in any
order it is preferred to provide about double that number of teeth
in order to lock the bar in a non-restore position by the means
hereinafter described. At this point it can be noted that the
central portion of this series of rack teeth is flattened as at 351
(see FIGS. 4 and 5), which permit the bar to be moved past a
locking plate 420 in the normal position shown. However, when the
bar 320 is rocked through an angle of 107.degree., the space
between the adjacent teeth 350 will engage the edge of the plate
420, thereby locking the bar 320 in its adjusted position.
Whether or not the shaft 320 is in the automatic restore position
shown in FIG. 1, or in the locked position just mentioned, the gear
teeth of each setting, or selection, bar 320 meshes with a first
idler gear 360 rotatably mounted on a pivot stud 361 and that, in
turn, meshes with a second idler 362 rotatably mounted on a stud
363. The two gears 360 and 362 are mounted radially of the fixed
bar 115 and drive shaft 120, as shown in FIG. 1. The second idler
362 meshes with a rack portion 364 on the forward end of a setting
bar 365 which runs lengthwise of the fixed bar, or axle 115 and the
rotating cylindrical drive shaft 120. Each bar 365 is held in its
proper angular position by being nested in a groove 116 in the
fixed bar 115. The bars 365 are therefore held against rotation of
the drive shaft 120 but are free to move axially along the fixed
shaft, or axle, 115.
Each of the interior setting bars 365 carries at an intermediate
point a grooved disk 367. The grooved disk 367 has a central
annular groove 368 and a pair of side walls 369, as shown in FIG.
1. The grooved disk 367 is mounted on its respective bar 365 by
means of a pair of collars 370 tightly holding the grooved disk
between them, each of the collars being riveted to the bar 365 by
suitable rivets 371. In order to prevent interference between the
different grooved disks 367 and their clamping rings 370, each
order of the selection mechanism is spaced from the next by an
increment slightly greater than the next one can be moved. It will
be understood that each of the eleven setting bars 365 (one for
each order of the value selection mechanism, three for setting the
date stamp, and one for each of the four controls previously
mentioned) will readily slide under each of the other disks 367.
The rings 368 non-rotatably engage the interior wall of the main
drive shaft 120. Since there are eleven such disks 367, it is
obvious that they prevent any of the setting bars 365 from being
displaced from their grooves in the axle 115. The outside wall of
the drive shaft 170 is provided with a series of eleven
longitudinal slots 376 so angularly arranged as to most
conveniently connect to the mechanisms in the print head 70 to
which they relate. In each such slot 376 is an exterior setting bar
377, the rear end of which is provided with gear teeth, or rack,
378. A pin is riveted at the point in its bar 377 where it will
register with the grooved disk 367 on the functionally related
interior setting bars 365. This pin 379, as shown in FIG. 1, is
adapted to engage the groove 368 in the functionally related
grooved disk 367 through a slot 375 through the walls of the drive
shaft 120.
It would appear from FIG. 1 that the interior bar 365 and the
exterior bar 376 lie in the same angular plane. However, this
figure has been distorted to show that the two are functionally
associated. Actually, as shown in FIG. 6, the two are angularly
separated. As a practical matter, it is preferred to have the print
wheels and the indicia for the stamp to trail the printing position
(bottom of the figure) by a very slight angle so that it may
contact an ink supply device and immediately print the stamp on the
mail close to the leading edge of the mail (which generally goes
from left to right). However, the setting mechanism is preferably
placed on top of the machine where it is readily available to the
operator, and with the unit order on the extreme right-hand as an
operator faces the machine. The date stamp controls are most
conveniently placed on the lower left side of the front of the
machine, as shown in FIG. 1, and the four print or non-print
controls can be set in any place convenient to the operator. The
angular displacement of the two setting bars 365 and 377 is readily
accomplished by the use of the slotted disk 367. Since the disk 367
is rigidly fastened to the inner bar 365, it moves axially of the
axle 115 and drive shaft 120 and in a plane perpendicular to both
as the inner setting bar 365 moves longitudinally. Also, since the
disk 367 forms a complete circle, the pin 379 (regardless of where
the outer slot 376 and the slot 375 through the bottom of the
exterior slot 376 into the interior of the cylindrical drive shaft
120, are located) is always in contact with the slotted disk 367
and hence is effective to set the outer setting bar 377 in exact
increments from the movement of the inner setting bar 365. Thus,
the manual setting devices can be arranged in the most advantageous
position on the outside of the cover and be directly connected to
its respective inner setting bar 365 and the outer setting bar 377
can be placed where most practical in the printing head 70. It can
be noted that the exterior setting bars 377 are held in their
respective slots 376 against radial displacement as the front ends
lie within the confines of the front actuator drum 501 and the rear
ends lie within the confines of the print head 70 itself.
Thus, as the main selection bar 320 is moved to a differential
position selected by the operator, the rack teeth 350, through the
medium of idler gears 360 and 362, moves the interior rack bar 365
forwardly an equal differential amount. By means of the grooved
disk, or collar, 367 and pin 379, the rack bar 377, lying in the
groove 376 in the exterior walls of the main drive shaft 12, is
moved a like amount. When the main drive shaft 120 is rotated to
enter the values into the respective registers 50 and 60 and rotate
the print head 70 to print the proper stamp on mail matter, the
rack 377 is held in an adjusted position as its pin travels
completely around a circle by its constant contact with the walls
369 of grooved disk 367. It will also be positively locked in this
position throughout the printing and registering portion of a cycle
of operation (the portion for each such operation being
coextensive) as will be described later under the heading "Printing
Head". It may be mentioned at this point that each cycle of
operation requires a complete circle of 360.degree.. Regardless of
whether the meter is set for a single cycle of operation and the
consequent automatic restore of the selection mechanism, or for a
continuous series of operations on a locked value, the drive shaft
120 must automatically complete a full circle and will then stop
unless an incoming piece of mail triggers another cycle before it
is stopped. The means for cycling the drive shaft 120 is contained
in the base and is not pertinent to this invention. However, it is
understood by those skilled in this art that it is controlled by an
incoming piece of mail operating a trigger. When operating
continuously, the succeeding incoming letter triggers the next
cycle before the completion of the pervious one, so the meter runs
continuously without stopping.
The means for rotating the main selection bars to set them for
either automatic restore or a fixed selection will now be
described. It is seen in FIG. 1 that an interior hand wheel 385 is
rotatably mounted on a collar 386 affixed to the forward end plate
107. Adjacent the inner end of the hub of hand wheel 385 is a
partial gear 387 (FIGS. 4 and 5). This partial gear 387 can be
resiliently detented in any adjusted position by means of five
detent notches 388 which can be engaged by a pin 389 carried by an
arm 390 that is pivoted on stud 392 and is resiliently biased into
engagement with the partial gear 387 by means of a tension spring
391. The partial gear meshes with an idler gear 395 that is
pivotally mounted on the plate 107 by any suitable means, such as
stud 396. The idler 395 meshes with a pair of locking gears 397 and
398, which are identical in construction, but since they are not
similarly set, are given distinguishing reference characters. These
gears are respectively mounted on studs 399 and 400 carried by the
end plate 107. Each of the gears 397 and 398 carry a Geneva wheel
401 and a 3-tooth gear segment 402 (see FIG. 5). The three elements
of gear 397 or 398 and its associated Geneva wheel 401 and 3-tooth
gear segment 402 are affixed together to form an integral
structure. The gear 397 and its assembly are effective to lock the
thousands order selection bar 320-m and the hundreds order
selection bar 320-c while the gear 398 and its assembly are
effective to lock the tens order selection bar 320-x and the units
order selection bar 320-u. (Where it is necessary to distinguish
between orders of the selection mechanism, the suffix u is used to
indicate the units order of the selection bar 320, the suffix x to
indicate the tens order, the suffix c to indicate the hundreds
order, and the suffix m to indicate the thousands order selection
bars.)
Associated with the wheels 397 and 398 and their integral Geneva
wheels 401 and 3-tooth gear segments 402 are a set of gear sleeves
410 mounted on the forward ends of the selection bars 320 into
which values can be selected. The gear sleeves are suitably keyed
to the respective selection bar 320 by any suitable means, such as
a chordal section mating with the flat 351 on the bar 320, so that
while the sleeves are held in a single plane, the bars 320 can move
longitudinally within them. These mutilated gear sleeves 410
comprise a pair of central gear teeth 411 (FIGS. 4 and 5). These
gears have a width, or thickness, equal to the thickness of the
Geneva disk 401 and the 3-tooth gear segment 302. Adjacent the two
central teeth 411 and lying on either side thereof is a long
half-thickness section 112 having the radius of a gear tooth and
extending angularly for a distance equivalent to two gear teeth,
but the trailing edge of this section 412 is a full width tooth
413. In either adjusted position, the Geneva wheel 401 will lie
between the trailing gear tooth 413 and the first adjacent central
tooth 411, thereby preventing rotation of the mutilated gear 410.
When the 3-tooth gear segment 402 comes to a position opposite the
mutilated gears 410, the first gear tooth of the 3-tooth gear will
engage the leading full tooth 413 and then drive the mutilated gear
410 through an angular distance of the two central gear teeth 411,
whereupon the Geneva wheel 401 again comes between the trailing
full width tooth 413 and the adjacent central tooth 411. Thus, the
gear 410 and consequently its selection bar 320 can be rotated
between two angular positions 107.degree. apart and will be locked
in the respective positions until again rotated by manipulation of
the hand wheel 387. Whenever the selection bar 320 is rotated from
the position shown in FIG. 1 by the means just described, the flat
341 on the back end of the selection bar is rotated through an
angle of 107.degree. and consequently the restore cam 342 will lie
opposite the flat 341 and can have no restorative effect upon the
bar 320. A similar flat 351 on the rearwrd portion of the gear
teeth 350 on the forward end of the selection bar 320 normally
faces a locking plate 420 that is rigidly mounted on the frame
plate 108. The locking late 420 is shown in dotted lines in FIG. 4.
In FIG. 4 the selection bars 320-u and 320-x are shown in the
position indicated in FIG. 1 in which the flats 351 on those
selection bars lie opposed to the locking bar 420, while the flats
351 on the hundreds and thousands order have been rotated to lie
angularly away from said plate. As shown in FIG. 4, the plate 420
has four arms which lie opposite the selection shafts 320-u, 320-x,
320- c and 320-m. When a selection bar 320 is so rocked, the
associated arm of the locking plate 424 will engage between two
adjacent teeth 350 on the bar 320 and hence it cannot be moved in
either direction. By the means just described, the selection
mechanism of the present invention can be set order-by-order from
the highest to the lowest from an automatic restore position into a
position in which automatic restoring is impossible and the
selection mechanism is locked in its adjusted position; and can be
unlocked from the lowest order to the highest.
It can be mentioned here that in the preferred form of this
invention, the hand wheel can be partially or fully locked against
adjustment by a locking wheel 900 (FIG. 1). However, since it is
not a necessary part of a meter according to Post Office
regulations, and it is fully described in the above-mentioned
copending application entitled "Locking Mechanism for a Postal
Meter", it will not be described here.
REGISTERS
The registers of the present invention are driven by the old and
well-known Thomas-type mutilated drum actuators 501 shown in FIG.
2. In the present invention a single drum is effective to drive all
of the orders of one of the registers and second drives all of the
orders of the second. Since both actuators are identical, although
they rotate in opposite directions, and the registers are identical
except that the ascending register will not have a "lock-out"
mechanism to disable the machine when the amount standing in the
register is less than could be set into the machine by an operator,
only the descending register will be described. The first drum 501
is mounted on the main drive shaft 120 of the machine. The drum is
provided with nine teeth of differentially longitudinally extending
teeth 502. The teeth 502 differ in length by approximately the
thickness of the driven gear 512 described in the next paragraph.
The drum 501 is rotated in a counter-clockwise direction in this
figure, and the driven gear 512 will be rotated one tooth-space if
the gear is in alignment with the right end of the lowermost tooth
502, two teeth if aligned with the right end of the second of such
teeth, and on to nine increments if aligned with the ninth, or
highest, such tooth. The tens-transfer mechanism is driven by a
tens-transfer tooth 503, which trails the lowermost, or trailing
tooth 502 by considerable space as shown. A pair of Geneva blocks
504 and 505, preferably formed integral with the drum 501, are
utilized to stop rotation of a driven gear 512 immediately after
digitation is completed. One block 504 is aligned with the space
between the trailing tooth 502 and the tens-transfer tooth 503, and
the second Geneva block 305 trails the transfer tooth 503, as shown
in this figure. Cooperating with the Geneva blocks 504, 505 is a
Geneva disk 511 (one on each shaft 510).
It has previously been indicated that there is a series of square
shafts 510 angularly arranged around the mutilated drum 501. These
square shafts are journalled in the front frame plate 101 and
intermediate frame plate 102, and pass through enlarged apertures
in the auxiliary plate 103. The descending register herein
described preferably has eight orders, so that conceivably it could
be used to register $999,999.99 in postage, although only the four
lower orders can receive selected values from an operator. The
number of registers is obviously not important to the invention
herein described, but it can be noted at this point that where a
particular order is referred to, the square shafts 510 will be
identified by -8 as referring to the eighth order, etc. As above
mentioned, each of the square shafts 510 is provided with a Geneva
block 511, as shown at 510-8 in FIG. 2. Each of the square shafts
510 in the lower four orders carries a 9-tooth gear 512 slidably
mounted thereon. Each of these gears has an extended hub provided
with an annular slot 513 in which will be the respective yoke 316
already mentioned. Hence, there would be four gears 512 which could
be engaged by the actuator drum 501. It will be seen, therefore,
that the positioning of a driven gear 512 with respect to the teeth
502 on drum 501, in the lowest four orders of the register, will be
effective, upon rotation of the drum, to enter incremental values
in the corresponding orders of the register through the incremental
rotation of the gears 512 and square shafts 510.
It should be mentioned at this point that tens-transfers are
effected through the driving of a 9-tooth tens-transfer gear 514
(FIG. 2) from the rotation of the drum 501 and the tens-transfer
tooth 503. Normally, the transfer gears 514 are out of registration
with the tooth 503. The gears 514 (FIG. 2) are moved into the plane
of the single transfer tooth 503 by means of a yoke 515 rigidly
secured to a tens-transfer shaft 516, the yoke engaging an annular
groove, not shown, in the hub of the transfer gear. The operation
of the bar 516, and consequently the placement of gear 514 either
in registration with the tens-transfer gear 503, or out of such
registration, will be described subsequently.
The register 50 itself is preferably placed between the auxiliary
frame plate 103 and the intermediate frame plate 102. In this space
there are a series of 40-tooth gears 520 rotatably mounted on the
main drive shaft 120. There is one such gear for each order of the
register. The 40-tooth gears are driven by their respective driving
gears (see FIG. 3) 521 which are rigidly mounted on the square
shaft 510 in registration with the 40-tooth gear 520. The 40-tooth
gear, in the preferred embodiment of this invention, drives a
20-tooth idler 522. These idlers 522 are mounted upon a common
shaft 523 and, in turn, mesh with and drive a 10-tooth dial gear
524. Attached to the gear 524 is a dial 525 which will be viewable
through an appropriate window in the meter cover (not shown
herein). It will be obvious from FIG. 3 that the differential
rotation of a selection gear 512 will effect a corresponding
differential rotation of the 9-tooth gear 521, as both are mounted
on the same square shaft. Such incremental rotation of the gear 521
will drive the 40-tooth gear 520, and accordingly, the idler 522
and the dial 525 will be rotated a differential amount depending
upon the location of the selection gear 512 with respect to the
teeth 502 of drum 501.
Rigidly secured to the 40-tooth gear 520, as by means of rivets
530, is a 4-tooth gear 531 and a Geneva block disk 532 (see FIG.
3). The 4-tooth gear 531 has its four teeth 533 equally spaced, or
ten gear apart with respect to the teeth of 40-tooth gear 520. The
Geneva block 532 has corresponding notches 534 adjacent each tooth
533 on 4-tooth gear 531. Adjacent the 9-tooth gear 521 which drives
the 40-tooth gear 520 but not connected thereto, is a driven gear
536, which gear registers with the 4-tooth gear 533 above
mentioned. Rigidly secured to the gear 536 is a Geneva wheel 537
whereby the gear 536 and Geneva 537 are turned simultaneously. The
Geneva 537 is provided with nine projecting cam faces 538. It
follows that rotation of the 9-tooth gear 521 on the square shaft
510 drives the 40-tooth gear 320, but the Geneva block 532 and
Geneva 537, because of the cooperation of these two, will hold the
gear 536 against rotation until the 40-tooth gear 520 has gone from
a 0 to a 9 position. At that time, the single tooth 533 will mesh
with the teeth of gear 536 and drive it one tooth-space, thereby
rotating the Geneva block 537 and the cams 538 one tooth-space
likewise.
A cam follower arm 544 is rigidly mounted on the tens-transfer bar
516 by any suitable means, not shown. The bar 516 is slidably
mounted in the front and intermediate plates 101 and 102,
respectively. Normally, the shaft 316 is held in its rearward
position by means of a detent mechanism which, for purposes of
illustration, is shown as spring-pressed ball 545 (FIG. 3) engaging
a pair of adjacent notches 546 in the bar 516. Normally, the bars
516 are positioned rearwardly by means of a restore disk 546 having
diametrically opposed cam faces 547. Thus, the bars 516 are
restored to their rearward inoperative position, both before and
subsequent to digitatation. This is preferred, as it permits
adjustment of the descending register by Post Office officials to
accommodate additional prepaid postage without regard as to whether
a tens-transfer is effected or not.
It has already been mentioned that the tens-transfer bar 516 also
carries the tens-transfer drive gear yoke 515 which is rigidly
secured thereon by any suitable means, not shown. The yoke 515
registers with an annular notch in the tens-transfer gear 514. It
follows that each step of the gear 536 and its Geneva disk 537 and
integral cams 538, is effective to push the follower arm 544
forwardly. This, of course, pushes the bar 516 forwardly and
accordingly the yoke 515 and tens-transfer gear 516 forwardly to be
in registration with the single tens-transfer tooth 303 on the drum
301.
It is believed obvious that the placing of the selection gear 512
in a proper incremental position on its square shaft 510 by means
of the selection mechanism described above will, upon rotation of
the drive shaft, first rotate that gear and the square shaft 510 on
which it is located an incremental amount, following which the
rotation of the gear is stopped by the registration of the Geneva
511 with the first Geneva block 504 on the drum. Whenever the
40-tooth gear 520 has gone through the 0 to 9 position, it will
have rotated the gear 536, Geneva 537 and the cams 538 one
tooth-space, thereby projecting the assembly of the follower arm
544, bar 516, yoke 515, and transfer gear 514 of the adjacent
higher order into alignment with the single tooth transfer gear
503. The break between the first Geneva block 504 and the second
block 505, which is aligned with the transfer tooth 503, permits a
single step of rotation of the square shaft 510 in the adjacent
higher order, and that rotation is then blocked by the second
Geneva block 505. It is seen in FIG. 7 that the second Geneva block
505 is longer than 504 but is not entirely around but is still
relatively short so that after the tens-transfer is effected and
rotation of the shaft 510 is definitely stopped, the Geneva 511
will not be in opposition to any blocking surface, such as 504 or
505.
It is customary in devices using the Thomas principle of the
mutilated drum and positionable selection gears driven thereby, to
use 10 teeth on the selection gear and subsequent mechanisms. It
has been found that by using 9-tooth gears, a substantially heavier
Geneva, such as 511, can be used. The 9-tooth Geneva gives a much
more pronounced arcuate section between the teeth and thereby
provides a stronger and more reliable detent, and one which does
not wear nearly as readily as the customary 10-tooth Genevas. This
enables a faster and longer operation of the meter and much longer
usage than would be possible with a 10-tooth gear. It had been
thought that 10-tooth gears were necessary in order to provide for
the proper operation of the tens-transfer mechanism. However, it
has been found that by using the 40-tooth gears between the
register drive shaft 510 and its register dial 525, the
tens-transfer can be properly secured. As a matter of fact, the two
gears 512 and 514 on the register driving shaft could have less
than nine teeth, such as eight, or even less; and the intermediate
gear could be a 30-tooth, or even a 20-tooth gear and accurate
tens-transfers be properly secured. The numbers mentioned are
preferred as they adapt themselves to the size and weight of the
meter.
It has been mentioned that one of the requirements of the Post
Office regulations is that when the descending register reaches the
amount equal to the maximum that can be set upon the selection
mechanism and thereby entered into the dials, the machine must be
locked against operation. In the present device this is
accomplished by means of the mechanism best shown in FIG. 3. A
locking shaft 550 is journalled in the front and intermediate frame
plates 101 and 102, respectively. This shaft carries four arms 551
rigidly mounted on the shaft by any suitable means, not shown. As
shown in FIG. 3, the arms 551 are each provided with a nose 552
which lies in the same plane as a diametrically notched disk 553
attached to the 20-tooth gear 522. The notches 554 of this disk are
so located that they register with the nose 552 each time the
respective dial 525 stands in a 0 position. The shaft 550 is biased
in a counterclockwise position in FIG. 3 by a spring 555 tensioned
between an arm 556, also rigidly attached to shaft 550 and a
suitable seat, not shown, on the frame. A link 557 connects the arm
556 to the clutch pawl 127 (FIG. 9). It is obvious that the shaft
550 cannot rock so long as any one of the noses 552 of the four
arms 551 register with the circumference of its respective disk
553. However, when all noses 552 can enter their respective notches
554, the set of four arms 551 and the shaft 550 will be rocked
(counter-clockwise in FIG. 3) to pull the clutch pawl 127 out of
engagement with notch 131 and thereby disable the clutch that
drives the main drive shaft 120. The machine is thus locked against
further operation until the descending register is reset by the
local Post Office.
In the preferred embodiment of this invention, four orders of the
register can be driven by the actuator 301, thereby registering up
to postage of $99.99 for each operation. Another four orders of the
register are provided without selection mechanism but operative to
be driven by the tens-transfer mechanism herein described. While
this excess register is believed so large that it will very seldom,
if ever, be used, it does permit a large user in sufficient amounts
to avoid the necessity of frequent trips to the Post Office to have
the meter reset.
It is believed obvious that the ascending register 60 of the meter
can be identical to the descending register herein described with
the elimination of the lockout mechanism just described. The
actuator, selection gears, register drive gear train, and the
tens-transfer mechanism are preferably interchangeable. If the
actuator 601 of the ascending register 60 is driven in the reverse
direction to the main drive shaft 120, this register will operate
additively while the descending register is operating
subtractively. This is readily secured by means of the gear train
126, 150 and 151 previously mentioned.
PRINT HEAD
It will be understood that their is a pair of setting bars 365 and
377 for each order of the value selection mechanism which, in the
preferred form of the present invention is four, as this enables
the large value stamp (up to $99.99) to be posted. There are,
therefore, four print wheels in the print head for registering like
values on the printed stamp. There will be three pairs of
exterior-interior setting bars 377, 365 for use in printing the
date, one for the month, two for the days of the month (the year,
since it is used so infrequently, can be set by a stylus). There is
a control bar adapted to set the "date stamp" into either a
printing or non-printing position, and another pair of setting bars
for setting two "slogan" plates into printing or non-printing
position, and a fourth for setting a "bulk rate slug" into either a
printing or non-printing position. It can be noted here that due to
the size of the print head (in the preferred form of the present
invention being approximately four and one-half inches in
diameter), there is available for printing slogans or other
material, such as return addresses, more than another linear seven
inches for such plates. In the preferred form of the invention, two
are used--one of three inches and one of four inches, both of which
can be set to non-printing or printing position. Hence, there are
eleven pairs of exterior-interior setting bars 377, 365, all of
which operate in substantially the same manner.
The value setting wheels which enter values into the register and
print the value of the stamp are readily settable through the
selection wheel previously mentioned. The date stamps are
controlled through wheels, preferably the hand-setting wheels 701
(FIG. 1). It will be understood that there are three such wheels,
although only one is shown in this figure, one such wheel being
used for printing the name of the month, and the other two for the
date of the month. A gear 702 on each such wheel meshes with an
idler 703, and that, in turn, meshes with a third gear 704. These
gears are rotatably mounted on pivot studs 705 carried by plate 706
extending between frame plates 107 and 108. The gear 704 meshes
with the rack 364 of the functionally related selection bar
365.
The print head 70 (FIG. 7) in the preferred form of this invention
carries four value print wheels 720 corresponding to the four
manually set selection wheels 301 previously described. These four
value print wheels 720 are preferably mounted on a single shaft 721
carried by a U-shaped frame member 722 rigidly mounted on the web
705 of the print head 70. As shown in this figure, the wheels must
vary slightly in shape and curvature, as they are mounted on a
shaft 721 that, if extended, would form a cord with the
circumference of the print head 70. Only one of these value print
wheels can be perpendicular to the circumference of the print head
and since the others are parallel to it, they decrease in size and
increasingly increase in curvature as shown.
These print wheels are set by means of the exterior setting bar
377, the operation of which has heretofore been described. The rack
378 on the rear end of this setting bar meshes with a gear 710
pivotally mounted on a mounting plate 711 by any suitable means,
not shown. The gear 710 meshes with an idler 713, likewise
pivotally mounted on the plate 711 by some suitable means, not
shown. The gear, in turn, meshes with a print wheel gear 715 which
is rigidly secured to each of the value print wheels 720. Thus, it
is seen that the longitudinal movement of the setting bars 365 and
377, through the gear train 710, 713 and 715, will set the
respective value wheels 720 to the proper positions. The value
printing wheels 720 are centered in a postage design die plate 730
which carries a design 731 approved by the Post Office. The die
plate 730 is affixed to the print head by any suitable means, such
as screws, not shown.
The mechanism for printing the date on the envelope adjacent the
stamp comprises a month printing wheel 740, two date setting wheels
741, 742 which can be identical, although the first one will never
print more than three digits, and a year wheel 743. As mentioned
previously, the year wheel, since it is set only once a year, can
be adjusted by a stylus. The three wheels 740, 741 and 742,
however, are changed more often and accordingly it is preferred to
control them from the manual setting of the setting wheels 701
previously mentioned. The setting wheels 701 (FIG. 1) position
interior setting bars 365 as heretofore explained, and they, in
turn, translate the exterior setting bars 377 for controlling the
three print wheels 740, 741 and 742. The longitudinal movement of
the three sets of bars for the dating mechanism to operate gear
trains similar to the gear train 710, 713 and 715 heretofore
described set the date stamps to the selected position.
It is well-known that in some types of mail the Post Office does
not want the date sprinted, so that the dating mechanism should be
selectively controlled--both to either a print or a non-print
position. This control can be readily secured by providing an
eccentric 745 which lies between opposed arms 746 and 747 on a
frame 744, which carry the dating print wheels. The frame 744 is
pivotally mounted on the web 705 of the print head. It will be
obvious from a glance of FIG. 7 that rotation of the eccentric 745
about its pivot 748 will rock the frame 744 through an angle
sufficient to move the entire frame away from the periphery of the
print head, so that it will no longer be in a print position. The
rotation of the eccentric on its shaft 748 can be secured through a
gear train meshing with the functionally related exterior setting
bar 377.
It was mentioned previously that the preferred form of the print
wheel of this invention has a diameter of 41/2 inches and
accordingly, there is approximately seven inches of space left for
slogan plates, or the like. It can be noted that when the print
head is at rest (full cycle position shown), there is a large blank
space between the tail end of the second slogan plate and the
postage die 730. It is preferred that there be no printing die in
printing position in the full cycle position. Preferably, this
usable space is divided into two sections, or slogan plates 760 and
761 (FIG. 7). In this figure, the first slogan plate 760 has a
length of three inches, and the second plate 761 has a length of 4
inches. These are much larger than any heretofore usable, as most
print heads heretofore have been about half the diameter of that in
this preferred form. The first plate 760 is pivoted on a stud 762
and is moved in and out of printing position by an eccentric 763
mounted on a shaft 764 carried by the web of the wheel. The
eccentric 763 is embraced by a pair of arms 765 which are connected
by a sleeve 766. The sleeve 766 is rigidly mounted on a bar 767
formed integrally with the circumference of the slogan plate 760.
It will be understood that any suitable slogan die can be mounted
on the plate 760 by any suitable means, such as screws (not shown).
The shaft 764 and its integral eccentric 763 can be rotated to rock
the slogan plate 760 into and out of printing position by means of
a gear train operated by an exterior setting bar 377, similar to
that previously described in connection with the postage value
print wheels.
The longer plate 761 is pivotally mounted on a stud 773 that
extends through an aperture 771 in the first slogan plate 760. The
plate 761 is controlled by an eccentric 775 formed on a shaft 776.
What appears to be another eccentric is actually a clearance
aperture 772 and a frame bar 774 that rigidly ties the two side
pieces, or webs, 705 that form the frame of the print head. The
inward or outward movement of this plate 761 is controlled by the
rotation of the eccentric 775 that is integral with a rotatable
shaft 776 journalled in suitable bearings carried by the web 705 of
the print head 70. The eccentric 775 is embraced between a pair of
arms 777 that are rigidly mounted on a post 778 which is rigidly
mounted on the peripheral wall of the slogan plate 761. This
eccentric is controlled in the same manner as those previously
mentioned.
One of the requirements of the Post Office of the manufacturer of
postage meters requires that the value printing devices be centered
in a proper digital position and be rigidly locked in their
adjusted position throughout the printing cycle, so that they are
not subject to displacement from the position selected by the
operator. This is readily secured in the present invention by means
of a locking arm 785 (FIG. 8) that is pivotally mounted on the
outside of a web 705 of the print wheel 70 as by means of a pivot
stud 786 rigidly mounted on the web of the print wheel. This
locking arm 785 carries four teeth 787, each of which, when the
locking arm 785 is rocked (clockwise in FIG. 8 from the position
shown) engages between the teeth 378 of the respective exterior
setting rack 377 which lie immediately outside of the inside web
705. It will be seen in FIG. 1 that there is at least one
inter-tooth space to the outside (to the right) of the print head
70. Since setting of the value wheel is to the right from a zero
position, it is obvious that the teeth 787 can mesh with the teeth
of these four exterior racks in any adjusted position of the racks.
When so locked against movement, not only the bar 377 and print
wheels 720 are centered and firmly held against any displacement,
but the respective selection bars 320 are also locked against
adjustment.
The locking arm 785 carries a roller 788 pivotally mounted thereon.
As the print head starts to rotate (counterclockwise in this
figure), the roller engages the leading beveled edge 789 of a cam
bar 790 that is rigidly mounted on the backside (left in FIG. 1) of
the frame plate 104. The cam plate 790 is spaced away from the
frame plate by suitable spacers and studs 791. The cam plate 790
has a length which keeps the locking arm 785 in deep contact with
the teeth of the rack 378 throughout the printing phase of a cycle
of operation. Trailing the locking cam plate 790 is an unlocking
cam plate 792, also mounted on the frame plate 104. This cam plate
likewise is spaced from the adjacent frame plate by suitable
spacers and studs 793. This cam plate 792 is located inside of the
locking cam plate 790 and as the roller 788 comes off of cam 790,
it is moved outwardly by a leading cam edge 794 and will thereafter
roll against the outside of this cam plate 792. In this position,
the locking arm 785 is out of locking engagement with the racks 378
and the entire setting mechanism can be restored to zero if
necessary.
It will be understood that a suitable inking mechanism 800 of any
suitable construction is placed ahead of the stamp die and before
the printing mechanisms of the print head can reach the printing
position, i.e., the lowermost peripheral edge of the print head in
FIG. 7.
* * * * *