Note: Descriptions are shown in the official language in which they were submitted.
'7~
HAND-HELD PRINTING APP~RATUS
This invention relates generally to hand-held
printing apparatus and specifically to a hand-held ink
jet printing apparatus for printing alpha-numeric
characters onto a suitable printing substrate such as
a large containerO
At the present time, there is a need for a relatively
compact and convenient hand-held printing apparatus
which can replace stencils for printing alpha-numeric
characters, e.g., manufacturers codes or part numbers,
addresses or ports o~ destination, or other legends or
information on crates, cartons, containers, or the like,
Although printing devices exist for use in packaging lines
where containers move past a printing station on a
conveyor, such devices are generally fixed in position
and are not adaptable for portable use. In addition, such
prior devices were often complex in design and used only
parts which had to be specially manufactured with the
result that the apparatus tended to be extremely costly.
s~
3~
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention
to provide a hand-held printing device for applying alpha-
numeric characters to cartons, boxes, and the like which
is compact and convenient to use.
Another object of this inven-tion is to provide a hand-
held printing device which is simple in design and can be
manufactured from commercially available parts.
The hand~held printing apparatus of the present invention
has a carriage adapted -to be held in the hand of the user.
Rollers mounted on the carriage allow the carriage to be
moved over a surface -to be printed such as the exterior of a
container. Ink jet printing means are mounted on the carriage
and are controlled by an electrical con-trol means remo-tely
located from the carriage. Signal generating means mounted
on the carriage supply electrical signals to the electrical
control means indicative of the rate at which -the carriage
is moved over the surface to be printed by the user.
In the preferred embodiment, a plurality of nozzles are
located in a common nozzle block mounted on carriage.
Electrically operated solenoid valves associated with each
nozzle control the supply of ink to the nozzles. A micro-
computer remotely loca-ted from the carriage controls the
operation of the solenoid valves. An encoder disk assembly
mounted on the carriage and associa-ted with the roller supplies
electrical signals to the microcomputer which indicate the
rate at which the carriage is moved over the printing surface.
The nozzles ln the common nozzle block are preferably
arranged in a single row in alignment with and at equally
spaced intervals from one another. The nozzles are jeweled
orifice nozzles having orifices in the range of 0.025mm to
0.215mm in diameter. The electrical cycle time of the elec-
trically operated solenoid valves is in the range of 0.1 to
10 milliseconds. The encoder disk assembly has an
~1
53d~
encoder disk which is mounted on a drive shaft and a photo-
detector subassembly. The drive shaft of the encoder disk
is driven by the movement of the wheels over the printing
surface. The ink jet printing means are connected to a
source of ink under pressure remote from the apparatus by
a flexible conduit. The remotely located electronic control
means is connected to the ink jet printing means by a
flexible electric cable.
Addltional objects, features, and advantages of the
invention will be apparent in the following description.
3~
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is perspective view of the device of this in-
vention being used to apply a label to a container.
Fig. 2 is a side view of the hand-held unit with por-
tions broken away.
Fig. 3 is a front perspective view of the hand-held
unit.
Fig. 4 is an isolated view of the signal generating
means of the device of Fig. 1.
Fig. 5 is a schematic diagram of the electrical con-
trol means of the device of Fig. 1.
Fig. 6 is a cross-sectional view of the nozzle block
of the device taken along lines VI-VI in Fig. 3.
Fig. 7 is a cross-sectional v;ew of a valve used in
the device taken along lines VII-VII in Fig. 2.
Fig. 8 is a front isolated view of one of the nozzles
used in the nozzle block of the device.
Fig. 9 is a close-up view of the ink source of the
device partially broken away.
~l65~
5.
DETAII,ED DESCRIPTION OF THE IN~7ENT~ON
Referring now to Fig. 1, there is shown a hand-held
printing apparatus of the present invention illustrated
generally as 11. The hand-held printing apparatus 11, has
a carriage 13 adapted to be held in the hand of the user
which is connected by flexible cable 15 to a remotely lo-
cated electrical control means 17 and remote source of
pressurized ink 19. Although the remotely located electrical
control means 17 and ink source 19 are shown mounted on a
wagon or dolly 21, it should be understood that the same
could be mounted in a pack which would be worn by the user 23.
Referring now to Fig. 2, the hand-held unit is designated
generally as 25 and includes a handle 27 extending from a
generally rectan~ular carriage or housing 29. Roller means
such as wheels 31 are mounted on the carriage for moving the
carriage 29 over a surface to be printed such as a box or
container. Wheels 31 are mounted on carriage 29 by suitable
bushings 33 and an axle 35.
As shown in Fig. 3, an ink jet printing means is mounted
on the carriage and includes a plurality of nozzles 37.
Nozzles 37 are preferably located in a common nozzle block 39
which fits withirl a slot 41 in the front wall 43 of carriage
29. Nozzles 37 are preferably aligned in a single row which
extends laterally of the direction of movement of the carriage
29 over the surface to be printed. As can be seen in Fig. 3,
the nozzles 37 are located between the paths of travel of
: wheels 31 so that when the apparatus is in use the wheels 31
will not pass over any printing produced on the printing surface
by the ink jet printing means. A follower wheel 45 can be
provided to add stability to the carriage as print is being
applied or wheels could be provided at four corners of the
carriage 29.
Each nozzle 37 comprises a single aperture for the
passage of ink. Alternatively, each nozzle 37 can comprise
a plurality of apertures which provide the same cross-
sectional area as the single aperture. The nozzles 37 are
~ ~'
3'~ ~
preferably jeweled orifice nozzles such as the sapphire
jewels used in acetylene torches and the like. Each
jeweled oriEice nozzle as shown in Fig. 6 and 7 has a
generally circular body 47 having an orifice 49 of rela-
tively smaller diameter on one face 51 and an opening 53
of relatively greater diameter on the opposite face 55.
The diameter of orifice 49 is in -~he range of 0.025mm to
0.215mm, and preferably is in the range of 0.145mm to
0.185mm.
As shown in Fig. 6, each nozzle 37 is set in a nozzle
block 39 preferably made of an inert material such as a
suitable plastic. The nozzle block 39 has a series of
generally circular recesses 57 having an internal diameter
selected to receive the external diameter of the nozzle
bodies 47. Recesses 57 are of sufficient depth to allow
the nozzles 37 to fit flush with the top surface 59 of
the block 39 when the nozzles are in place. The nozzles
37 are placed in recesses 57 with the opening 53 being
first to enter the recess 57. The distance between the
center of each orifice 49 when the orifices are vertically
aligned is in the range of O.Olmm to 5.Omm and preferably is
in the range of 0.05mm to 0.50mm.
A series of rigid tubes 61 lead from the nozzle recesses
57 in block 39 and project outwardly from the side of block
39 opposite recesses 57. Tubes 61 and hence nozzles 37
are each in fluid communication with the output port 63 of a
valve 65 (Fig. 2) located within the carriage 29 by means
of fluid conduits 67. Conduits 67 are of any suitable
commercially available conduit, e.g., of metal or plastic
material and are preferably in the range of 0.127mm to
1.270mm in diameter.
Valves 65 may be any suitable commercially available
fast acting valve having an electrical time in the range of
from 0.1 to 10 milliseconds, preferably in the range of
1.0 to 4.5 milliseconds. Suitable valves can be either a
single-acting spring return, a double-acting electromagnetic
~S~'J'5~
solenoid valve or a piezoelectric valve. Preferably a
single-acting spring return solenoid valve such as is
shown in Fig. 7 is used. Such a valve 65 typically has
an outpu-t port 63 and an input port 69 leading to a
fluid chamber 71 within an outer housing 73. A plunger
75 closes off output port 63 when in ~e position shown and
has an elongated body 77 which is slidably received within
a solenoid coil 79 held in place by mounting collars 81, 83.
The solenoid coil and valve housing 73 are preferably coated
with a suitable epoxy resin to prevent ink fluid damage.
The solenoid coil 79 when energized exerts an electro-
magnetic force on plunger body 77 to cause the plunger 75
to move out of sealing engagement with the output port 63,
allowing ink to flow out the output por-t. A spring 85
mounted between collar 81 and plunger 75 urges -the plunger
75 into sealing engagement with the output port 63 and thus
prevents the flow of ink Erom the fluid chamber 71 when
solenoid coil 79 is de-energized. Wires 87, 89 run from
solenoid coil 79 to the control circuit of the electrical
control means 17 by way of a flexible electrical cable 91.
rJhe input ports 69 of valves 65 are each in fluid
communication with a common ink manifold 93 by means of fluid
conduits 95 which are similar to fluid condui-ts 69. Ink
manifold 93 communicates with ithe pressurized ink source 19
(Fig. 1) by means of a flexible ink line 97. The pressurized
ink source 19 can comprise a reservoir and pressure means
such as a vibrator pump to supply air pressure to the reservoir.
An on-off switch 99 on handle 27 is provided between solenoid
valves 65 and the electrical con-trol means 17.
As shown in FigO 2 and 4, a timing pulley 101 is
mounted in carriage 29 on a drive shaft 103. Timing pulley
101 is connected to and driven by a~le 35 of front wheel
31 by means of timing belt 105. The end of drive shaft
103 opposi-te carriage wall 107 has an encoder disk
3~
109 mounted thereon by suitable bushings 111 said encoder
disk being associated with a photo detector assembly 113.
As best seen in Fig. 4, photo detector 113 includes
an elongated bar 115 having a side flange 117 in which i5 mQUnted
a light source 127 and a matching side flange 119 in which
is mounted a photo electric sensor 129. Encoder disk 109
is suitably positioned on drive shaft 103 so that the path
of travel of holes 121 along the outer periphery of disk 109
is in the path of light from the light source 127 in fl.ange
117 and the photo detector 129 located in flange 113.
Electrical leads 123, 125 running from the photo detector
subassembly 113 to the electrical control means 17 carry
electrical pulses created by the movement of disk 109 and
holes 121 through the light beam 131 between the source 127
and the photo cell 129.
In this manner, the spacing between holes 121 on encoder
disk 109 can be correlated to the distance between the columns
of print generated by the electrical control means 17 on the
printing surface. The ink jet printing device 25 prints a
column through nozzles 37 when a hole 121 or select number of
holes comes into the view of the photo detector subassembly
113. Encoder disk 109 and photo detector subassembly 113
thus comprise signal generating means associated with wheel
31 for supplying to the microcomputer electrical signals
indicative of the rate at which the carriage 29 is moved over
the surface to be printed. Although an encoder disk and
photo detector subassembly have been shown, other signal
generating means can be utilized such as fluidic or electro-
magnetic to perform the same function.
The source of pressurized ink 19 is shown in greater
detail in Fig. 9. Pressure means such as a vibrator pump
135 supply air pressure through a hose 137 to a reservoir
133 which is filled with ink from the top by means of a
cap 139. Pump 135 is suspended within reservoir housing
141 by means of resilient bands 143. A vent
valve 145 in air hose 147 allows the air pressure to
reservoir 133 to be adjusted. Air pressure in the range
of 0.5 to 7 psi is acceptable for the present purpose.
A filter 149 can be utilized to filter the ink passing
through ink line 97 to manifold 93.
The operation of the present invention will now
be described in greater detail. The operation of the
electrical control means 17 is shown schematically in
Fig. 5. Movement of the hand-held unit 25 by the user
across the surface to be printed causes axle 35 (Fig. 2)
attached to wheel 31 to rotate. Rotation of axle 35
causes corresponding rotation of drive shaft 103 through
belt 105. Movement of drive shaft 103 causes holes 121 in
encoder disk 109 (Fig. 4) to pass between the light source
127 and photo cell 129 which are mounted in the opposing
flanges 117, 119 of photo detector subassembly 113. Inter-
ruption of light beam 131 causes electrical pulses to be
sent through lines 123, 125 to the microcomputer 17 indicative
of the speed in which the hand-held unit 25 is being moved over
the printing surface.
Microcomputer 17 has been programmed by the user through
an input device 151 (Fig. 5) to direct the printing of a
desired character message on the printing surface. The control
circuit of microcomputer 17 is electrically connected to
the solenoid valves 65 (Fig. 2). Valves 65 are thus selectively
and intermittently actuated by the microcomputer 17 to allow
ink to flow from manifold 93 through output ports 63 to jeweled
orifice nozzles 37 and onto the printing surface. The selective
actuation of valves 65 by the microcomputer 17 as the carriage
29 is moved over the printing surface allows a message to be
printed in dot~matrix format with columns of the dot-matrix
being printed only when holes 121 in enccder disk 109 are
aligned with the light beam 131.
An invention has been provided with significant advantages.
The ink jet printing apparatus is suitable for printing large
size alpha-numeric characters on a printing surface such as
that of a container in a warehouse and is portable and compact.
q~
The device is also simple in design and utilizes commercially
available parts making it economically feasible for the
intended application.
While the invention has been shown in only one of its
forms, it should be apparent to those skilled in the art that
it is not so limited but is susceptible to various changes
and modifications without departing from the spirit thereof.
