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Claims  |
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What is claimed is:
1. In a wire-matrix printer of the type including at least three
reciprocable print wires, means for mounting inner printing ends of the
wires, in a vertical column for movement toward and away from a printing
station, and a plurality of individual actuators having portions connected
to the outer ends of the print wires for reciprocating them to print
characters, the improvement characterized by:
the print wires comprising substantially straight wires of uniformly
varying length; and
means for mounting the print wires essentially horizontally and parallel to
each other in a vertical column throughout their lengths, for
substantially linear reciprocation along spaced, parallel, essentially
horizontal printing axes, and so that the lowermost wire in the column is
the shortest and each successive higher wire in the column is a
predetermined amount longer than the preceding one, whereby the outer ends
of the print wires define a horizontally spaced and vertically stepped
array.
2. A printer as recited in claim 1, wherein the print wire mounting means
includes:
a plurality of spring reeds corresponding one to each print wire;
means for mounting the spring reeds generally vertically in a parallel row
such that the lower end of each reed is fixed and the upper end is free to
flex and is aligned with the outer end of the corresponding print wire;
and
means for coupling the outer end of each print wire to the upper end of the
corresponding reed.
3. A printer as recited in claim 2, wherein the coupling means includes:
a plastic insert mounted on the upper end of each reed; and
a wire loop formed at the outer end of each print wire and flexibly coupled
about the plastic insert so that the print wire reciprocates essentially
horizontally in response to flexing movement of the reed.
4. A printer as recited in claim 3, wherein the wire loop comprises an
expansion spring shaped to resiliently grip portions of the perimeter of
the plastic insert to couple the print wire to the reed.
5. A printer as recited in claim 4, wherein:
each plastic insert comprises a plastic tip attached to the upper end of
its corresponding reed, the tip having inner and outer flat faces facing
toward and away from the printing station, respectively, the outer tip
face being formed with a horizontal groove perpendicular to both the
corresponding print wire and reed, the loop being of such size that a
first portion of the loop is received in the groove and a second portion
of the loop opposed to the first loop portion fits over the tip and
expands the loop thereby to resiliently grip the inner face of the tip
with the loop.
6. A printer as recited in claim 5, wherein the tip is formed with an
inclined camming surface at the top of the front face which forces the
second portion of the loop outward and, with the loop placed over the tip,
into resilient gripping engagement with the inner face, so that the print
wire and reed are assembled with a snap-on fit.
7. A printer as recited in claim 3, wherein the plastic insert is formed
with a central longitudinal groove in the upper surface thereof running in
the same direction as and parallel to the print wires, a section of the
body of the next higher print wire being received in the longitudinal
groove above the upper end of every reed except the uppermost one each
received print wire being out of contact with the reed and insert
corresponding to the next lower print wire.
8. A printer as recited in claim 3, wherein each spring reed comprises a
Latin cross, t-shaped member having the plastic insert affixed to the top
of the t, above the crossarm, and the wire is coupled about the insert
above the crossarm.
9. A printer as recited in claim 8, wherein:
the insert has a generally rectangular perimeter about the top of the t;
and
the wire loop has a generally elliptical configuration with inner and outer
straight side legs shaped to fit the contours of the insert with an
expansionspring fit.
10. A printer as recited in claim 9, wherein each insert comprises a
plastic tip molded about the upper end of its corresponding reed above the
crossarm, each tip having the first groove for receiving and locating a
portion of its corresponding wire loop, and a second groove for receiving
a portion of the next higher print wire out of contact with the tip.
11. A printer as recited in claim 1, wherein the print wire mounting means
includes:
a plurality of spring reeds corresponding one to each print wire, each reed
comprising a Latin cross, t-shaped member of such material and thickness
that the body of the reed comprises a leaf spring;
means for mounting the reeds generally vertically in a parallel row so that
the base of the t is down and is fixed at its lower end, so that the tip
of the t above the crossarm is free to flex toward and away from the
printing station and is aligned with the outer end of the corresponding
print wire, and so that the crossarm of the t is generally horizontal and
generally perpendicular to the plane of the vertical print wire column;
and
means for coupling the outer end of each print wire to the tip of the
corresponding reed.
12. A printer as recited in claim 11, wherein the reeds comprise identical
members, and the reed mounting means is arranged to mount the reeds in a
horizontally spaced and vertically stepped array corresponding to that
defined by the outer ends of the print wires.
13. A printer as recited in claim 11, wherein the actuators include:
means for biasing the crossarm of each reed away from the printing station
to hold the reed in a cocked position, in which the reed body is bowed to
store potential energy; and
means for releasing the bias applied to any given reed when it is desired
to print a dot with its companion print wire, the reeds being so
constructed and mounted that the cocked spring body of the reed then takes
over and fires the associated print wire toward the printing station to
print a dot.
14. A printer as recited in claim 13, wherein:
the biasing means comprises a plurality of magnetic means, one to each
reed, for attracting the crossarm of a corresponding reed and magnetically
latching it in the cocked position, the reeds being made of ferromagnetic
material so as to constitute magnet armatures; and
the means for releasing comprises a plurality of means one to each biasing
means for individually demagnetizing its corresponding magnetic means to a
sufficient degree where its corresponding magnetic means no longer is
capable of holding the associated reed in the latched position.
15. A printer as recited in claim 14, wherein each magnetic means is so
constructed and arranged that it acts as an electromagnet when attracting
the associated reed into the latched position and as a permanent magnet
when holding the reed in the latched position.
16. A printer as recited in claim 14, where each magnetic means includes:
a magnet core mounted parallel to its corresponding reed on the opposite
side of such reed from the corresponding print wire, each core having
spaced pole faces aligned with the ends of the crossarm of its
corresponding reed; and
electrical circuit means for magnetizing and demagnetizing the core.
17. A printer as recited in claim 16, wherein:
the reeds comprise identical members and the cores comprise identical
members;
means are provided for fastening the reeds and cores together into
individual subassemblies each consisting of one core and one reed; and
means are provided for mounting the core-reed subassemblies in a parallel,
horizontally spaced and vertically stepped array corresponding to the
pattern defined by the outer ends of the print wires so that the tips of
the successive reeds in the array are aligned with the outer ends of the
corresponding print wires.
18. A printer as recited in claim 14, wherein:
the reeds comprise relatively thin, flat plates and
the stems of the reeds taper inwardly from the base of each reed to the
crossarm, with the narrowest portion of the stem being located just below
the crossarm.
19. A printer as recited in claim 14, wherein:
the reed mounting means are so arranged that, in a neutral unattracted
condition, the reeds incline forward from base to tip toward the printing
station at an angle .theta. from the vertical.
20. A printer as recited in claim 19, wherein the magnetic means are so
arranged and the angle .theta. is so set that, when magnetically
attracted, each reed flexes rearward away from the printing station and
past the vertical so that the crossarm is inclined from the vertical at an
angle .phi. when latched, with the reed stem bowed in a retroflex curve.
21. A printer as recited in claim 20 wherein the angle .theta. is set
approximately equal to the angle .phi., the combination of the angles
.theta. and .phi. determining the amount of the potential energy storable
in each cocked spring reed, given a particular reed material and geometry.
22. A printer as recited in claim 20, wherein the magnetic means include
pairs of spaced pole faces, one pair to each reed, mounted on the opposite
side of the reed from the companion print wire, the pole faces in each
pair being aligned with opposed areas at the ends of the crossarm of the
associated reed, the pole faces being bevelled away from the reed and the
printing station at the angle .phi. set in accordance with the reed
geometry so that the opposed crossarm areas at the ends thereof lie flat
against the bevelled surfaces of the pole faces to magnetically seal the
reed crossarm against the pole faces with the crossarm closing the gap
between the pole faces.
23. A printer as recited in claim 14, wherein:
the magnetic means includes pairs of spaced pole faces, one pair to each
reed, mounted on the opposite side of the reed from the companion print
wire, the pole faces in each pair being aligned with opposed areas at the
ends of the crossarm of the associated reed;
the reed mounting means are so arranged that, when magnetically attracted,
each reed body flexes rearward away from the printing station and the
crossarm is inclined at an angle .phi. from the vertical; and
the pole faces are bevelled away from the reed and the printing station at
the angle .phi. set in accordance with the reed geometry so that the
opposed crossarm areas at the ends thereof lie flat against the bevelled
surfaces of the pole faces to magnetically seal the reed crossarm against
the pole faces with the crossarm closing the gap between the pole faces.
24. A printer as recited in claim 1
I. wherein the mounting means for the print wires include: a plurality of
magnet armatures corresponding one to each print wire;
means for mounting the armatures so that portions thereof are movable
toward and away from the printing station and portions thereof are aligned
with the outer end of the corresponding print wire; and
means for coupling the outer end of each print wire to the aligned portion
of the corresponding armature and
Ii. wherein the actuators include:
the armatures;
a plurality of magnet cores corresponding one to each armature, each core
having a pair of spaced pole faces;
means for mounting each magnet core adjacent to its companion armature on
the opposite side from the associated print wire and the printing station
so that the pole faces are aligned with portions of the corresponding
armature;
means for selectively magnetizing and demagnetizing each core so that (1)
when the core is magnetized, it attracts the armature against the pole
faces to bias the armature and the corresponding print wire to a retracted
position with respect to the printing station, and (2) when the core is
demagnetized, the armature is magnetically released; and
means for driving the armature and associated print wire forward toward the
printing station to print a dot when the core is demagnetized.
25. A printer as recited in claim 24, wherein the cores comprise identical
members, and the core-mounting means are arranged to mount the cores with
the pole faces located in a horizontally spaced and vertically stepped
array corresponding to the pattern defined by the outer ends of the print
wires.
26. A printer as recited in claim 25, wherein the cores comprise relatively
thin, generally flat plates mounted in spaced, parallel vertical planes
and vertically stepped from each other, the pole faces being disposed at
spaced areas along inner, generally flat surfaces of the cores.
27. A printer as recited in claim 26, wherein each core has a base portion
and a pair of arms extending toward each other from the base portion so as
to define an air gap in the space between the inner tips of the arms,
areas of the arms adjacent to the inner tips constituting the pole faces
of the core.
28. A printer as recited in claim 27, wherein:
the armatures comprise flat spring reeds;
the armature mounting means are arranged for mounting the reeds generally
vertically and, generally parallel to the associated core so that one end
is fixed and the other end is free to flex toward and away from the
printing station and the associated core, the armature reed having
portions aligned with and overlapping the pole faces of the core so that
these portions are attracted to and magnetically latched against the pole
faces when the core is magnetized, the reed being further mounted so that
the body of the reed bows rearward when the reed is latched to cock the
reed in the retracted position; and
the driving means comprises the cocked spring reed body, which stores
sufficient potential energy in the cocked position to drive the associated
print wire against the printing station.
29. A printer as recited in claim 28, wherein the reed-mounting means
comprises means for fastening each reed to the base portion of the
associated core so that the overlapping armature portions of the reed are
normally spaced from the pole faces by a preset distance when the
associated core is in a neutral, nonmagnetized state.
30. A printer as recited in claim 29, wherein:
the reed fastening means are so arranged that, in the neutral,
nonmagnetized state, the reeds incline forward from base to tip toward the
printing station at an angle .theta. from the vertical.
31. A printer as recited in claim 30, wherein the cores are so arranged
that, when magnetically attracted, each reed flexes rearward past the
vertical and the reed is inclined from the vertical at a reverse angle
.phi. when latched, with the reed body bowed in a retroflex curve.
32. A printer as recited in claim 31, wherein the angle .theta. is set
approximately equal to the angle .phi. , the combination of the angles
.theta. and .phi. setting the amount of potential energy storable in each
cocked spring reed, given a particular reed material and geometry.
33. A printer as recited in claim 31, wherein the pole faces of the core
are bevelled away from the reed and the printing station at the angle
.phi. set in accordance with the reed geometry so that the facing areas at
the tips of the crossarms lie flat against the bevelled surfaces of the
pole faces to magnetically seal the reed against the pole faces with
portions of the reed closing the gap between the pole faces.
34. A printer as recited in claim 24, wherein each core comprises a
symmetrical generally triangular C-shaped member having a base leg and a
pair of arms sloping inwardly toward each other from the base leg and
spaced from each other to define an air gap in the space between the inner
tips of the arms, the pole faces of the core being defined by areas of the
core adjacent to the inner tips of the arms.
35. A printer as recited in claim 34, wherein the core is shaped so that
the pole face areas face the armature and are generally trianglular.
36. A printer as recited in claim 35, wherein the triangular pole face
areas are so disposed that corresponding vertices of each triangle are
located at the inner facing tips of the arms, so that the air gap is
defined between facing angles of the arms.
37. A printer as recited in claim 36, wherein the facing angles are
identical obtuse angles.
38. A printer as recited in claim 35, wherein:
the armature comprises a flat spring reed fixed at one end and having a
free end mounted for flexing movement toward and away from the pole faces,
the reed having opposed areas respectively aligned with and overlapping
the pole faces; and
the pole faces are bevelled away from the reed and the printing station at
angles so that the opposed portions of the reed in the attracted position
lie flat against the pole faces and are magnetically sealed thereagainst.
39. A printer as recited in claim 38, wherein: the cores comprise
relatively thin, flat plates wherein the core mounting means positions the
cores in parallel vertical planes adjacent to the reeds, with the base leg
of the C horizontal and with the legs tapering upwardly toward the top and
the air gap centered over the middle of the base leg and horizontally
aligned with the center of the reed, the cores and the reeds being
horizontally spaced and vertically stepped in accordance with the pattern
of the outer ends of the print wires.
40. A printer as recited in claim 39, wherein the reed mounting means
includes means for fixing a lower end of each reed to an area at the
center of the base leg of the corresponding core, the working length of
the reed and thus the resultant spring force being a function of the
length of the base leg of the core and the angle of inclination of the
arms of the core, which set the vertical altitude between the reed
armature portions and the point of affixation of the reed to the base leg
of the core.
41. A printer as recited in claim 40, wherein the surface of the base leg
of the core against which the reed is mounted is bevelled downward and
away from the printing station at an angle .theta. set so that the reed
projects forward toward the printing station at the angle .theta. when the
core is not magnetized, the spacing between reed armature portions and
pole faces when the core is non-magnetized being set by the angle .theta.
and the length of the reed from the mounting point to the pole faces.
42. A printer as recited in claim 41, wherein .theta. is set approximately
equal to .phi., the combination of the angles .theta. and .phi. with the
reed length and material, setting the amount of potential energy storable
in the cocked spring.
43. A printer as recited in claim 34, wherein:
the core arms have equal rectangular cross sections; and
the means for magnetizing and demagnetizing each core include electrical
circuit means having a pair of electrical windings, one winding being
positioned on each core arm between the pole face and the base leg of the
C.
44. A printer as recited in claim 43, wherein:
the windings are prewound on plastic bobbins having rectangular mounting
holes shaped to fit over the tips of the core arms the core arms being
formed with enlarged shoulders near the bases of the arms for receiving
the bobbins.
45. A printer as recited in claim 44, wherein the circuit means further
include plastic inserts shaped to fit along a side wall of each core at
the base of each arm and having electrical connector plugs for the
windings projecting downward beneath the base leg of the core, and a
printed circuit board fastened to the printer below the cores and
receiving the connector plugs for connecting the windings to control
circuits for operating the printer.
46. A printer as recited in claim 24, wherein the means for selectively
magnetizing and demagnetizing each core includes electrical circuit means
arranged to:
1. magnetize the core so as to latch the armature in the rearward position
prior to a first printing operation;
2. demagnetize the core to actuate the means for driving the armature and
print wire to print each required dot; and then
3. promptly remagnetize the core so as to relatch the armature on rebound.
47. A printer as recited in claim 46, wherein the core and circuit means
are so constructed and arranged that an electrical pulse in a first or
forward direction magnetizes the core sufficiently to attract and
magnetically latch the armature against the core, and that a momentary
electrical pulse in the opposite or reverse direction demagnetizes the
core sufficiently to release the armature.
48. A printer as recited in claim 47, wherein the driving means includes a
spring tensioned on latching of the armature and released on partial
demagnetization of the core to fire the print wire toward the printing
station.
49. A printer as recited in claim 48, wherein the electrical circuit means
are so arranged that the forward pulse is stronger than the reverse pulse
and so that the core is not driven to magnetic zero, below the H axis of
the operating magnetic B-H curve for the core material, by the reverse
pulse.
50. A printer as recited in claim 49, wherein the core and pulsing means
are so arranged that the core acts as an electromagnet when attracting the
armature into the latched position and as a permanent magnet when holding
the reed in the latched position.
51. A printer as recited in claim 50, wherein each core has an operating
magnetic B-H curve as illustrated in FIG. 14 of the drawings.
52. A printer as recited in claim 1;
I. wherein the mounting means for the print wires include a plurality of
magnet armatures corresponding one to each print wire, each armature
comprising a flat spring reed;
means for mounting the reeds generally vertically in a parallel row so that
a lower end of each reed is fixed and an upper end thereof is free to flex
toward and away from the printing station and portions thereof are aligned
with outer ends of the corresponding print wire; and
means for coupling the outer end of each print wire to the aligned portion
of the corresponding reed; and
Ii. wherein the actuators include:
the reeds;
a plurality of magnet cores corresponding one to each reed, each core
comprising a flat plate having a pair of core arms extending toward each
other from a base portion so as to define an air gap between the inner
tips of the arms, areas of the arms adjacent to the inner tips
constituting spaced pole faces of the core;
means for mounting the magnet cores generally vertically adjacent to the
companion reeds on the opposite side from the associated print wire and
the printing station so that the pole faces are aligned with facing
portions of the corresponding reeds; and
means for selectively magnetizing and demagnetizing each core so that (1)
when the core is magnetized, it attracts the facing portions of the reed
against the pole faces to cock the reed in a retracted position with
respect to the printing station, and (2) when the core is demagnetized,
the reed is magnetically released so that the cocked spring reed drives
the associated print wire forward toward the printing station to print a
dot.
53. A printer as recited in claim 52, wherein the progressive variation in
print-wire length is a given amount greater than the combined thicknesses
of the reed and the core.
54. A printer as recited in claim 53, wherein the mounting means for the
reeds and cores include means for mounting each pair of reeds and cores in
a horizontally spaced and veritcally stepped print head assembly
corresponding to the spaced and vertically stepped array of the outer ends
of the print wires.
55. A printer as recited in claim 54, wherein the mounting means for the
reeds and cores further include:
a plurality of actuator mounting panels associated one with each core and
reed pair;
means for mounting each core to its companion panel so that the panel, core
and reed form a discrete actuator subassembly for the associated print
wire; and
means ford assembling the mounting panels together to form a print head
assembly.
56. A printer as recited in claim 55, wherein:
the mounting panels, cores and reeds all comprise identical members in each
actuator subassembly, and the panel-assembling means is arranged to mount
the panels in the horizontally spaced and vertically stepped array
corresponding to that defined by the inner ends of the print wires so that
the panel positions set the corresponding positions of the cores, reeds,
and the outer ends of the associated print wires coupled to the reeds.
57. A printer as recited in claim 56, wherein each panel is formed with a
slotted extension at its upper-end for receiving and guiding the print
wires coupled to all higher subassemblies in the array.
58. A printer as recited in claim 57, wherein the mounting panels comprise
flat blocks having a thickness equal to the desired horizontal increment
of length between consecutive print wires, the blocks having mounting
recesses for receiving the associated core and reed, and the blocks being
assembled in a stacked vertical, parallel array with each block contacting
the block associated with adjacent print wires.
59. A printer as recited in claim 58, further comprising front and rear
print head mounting panels, also comprising flat blocks, the front-head
mounting panel being assembled in contacting engagement with the first
actuator-mounting panel in the array (for the lowermost wire) and the rear
head-mounting panel being assembled in contacting engagement with the last
actuator-mounting panel (for the uppermost wire); and
means for fastening the front and rear head-mounting panels together with
the actuator-mounting panels into a rigid, cage-like mounting assembly for
the print wires and actuator members.
60. A printer as recited in claim 59, wherein the front head-mounting panel
is formed with an upwardly extending slotted guide for guiding all of the
print wires to the printing station.
61. A printer as recited in claim 60, further comprising a cover plate
secured atop the front and rear head-mounting panels and covering the
array of print wires.
62. A printer as recited in claim 59, further comprising a printed circuit
board secured to the bottom surfaces of the front and rear head-mounting
panels, and carrying electrical circuit means for magnetizing and
demagnetizing the cores.
63. A printer as recited in claim 62, further comprising:
a reciprocable carriage for the print head; and
means for mounting the front and rear head-mounting panels to the carriage
to position the print head on the carriage and with respect to the
printing station.
64. A printer as recited in claim 59, wherein the actuator-mounting panels
comprise identical pieces having locating holes on one side and mounting
pins on the other arranged to mount the panels together in the stacked
assembly and to set the required position of each panel with respect to
the next, thus setting the height of each print wire in the array, and
wherein the front and rear head-mounting panels have similar locating and
mounting means to set the position of the first and last actuator-mounting
panels with respect to the front and rear head-mounting panels.
65. A printer as recited in claim 59, wherein the fastening means
comprises:
a fastening band threaded through mounting holes in all of the panels;
a spring for urging one end of the band against one of the front and rear
mounting plates so as to urge the panels together; and
retainer means for holding the band in place against the assembly.
66. A printer as recited in claim 65, wherein the band comprises a square
U-shaped metal band having outwardly curved tips at the ends of the U.
67. A printer as recited in claim 66, wherein the keeper means comprises a
retainer plate positioned against the front panel and having receiving
holes for receiving and retaining the outer tips of the band.
68. A printer as recited in claim 67, wherein the band-urging spring
comprises a bowed flat spring keeper plate having outer tips received
against spaced contact points along the outer surface of the rear
head-mounting panel, and having a bowed central section spaced from the
rear head-mounting panel and engaging the base of the band so as to urge
the band longitudinally rearward of the head mounting panels to urge the
tips of the band into the retaining holes in the retainer plate.
69. The printer as recited in claim 54, wherein in each actuator;
each reed comprises a t-shaped flat plate fabricated of a ferromagnetic
spring metal;
each core comprises a rectangular C-shaped, flat metal plate fabricated of
a magnetizable, highly retentive metal; and
each pair of reeds and cores are of such relative sizes and are so mounted
with respect to each other that the gap between the arms of the C aligns
with the crossarm of the t and areas at the ends of the crossarm of the t
overlap facing portions of the ends of the core arms, the overlapping
areas of the core arms comprising the pole faces of the core.
70. Apparatus for coupling an outer end of a reciprocable wire to an
actuator, the wire having an inner working end positioned adjacent to a
work station, which comprises:
a spring reed for actuating the wire;
means for mounting the spring reed generally perpendicular to the wire in a
position such that one end of the reed is fixed and the other end is free
to flex and is aligned with the outer end of the wire;
a plastic insert mounted on the free end of the reed; and
a wire loop formed at the outer end of the wire and flexibly coupled about
the plastic insert so that the wire reciprocates essentially linearly
along a work axis in response to flexing movement of the reed.
71. Apparatus as recited in claim 70, wherein the wire loop comprises an
expansion spring shaped to resiliently grip portions of the perimeter of
the plastic insert to couple the wire to the reed.
72. Apparatus as recited in claim 71, wherein:
the plastic insert comprises a plastic tip attached to the free end of the
reed, the tip having inner and outer flat faces facing toward and away
from the work station, respectively, the outer tip face being formed with
a horizontal groove perpendicular to both the wire and the reed, the loop
being of such size that a first portion of the loop is received in the
groove and a second portion of the loop opposed to the first loop portion
fits over the tip and expands the loop thereby to resiliently grip the
inner face of the tip with the loop.
73. Apparatus as recited in claim 72, wherein the tip is formed with an
inclined camming surface at the top of the front face which forces the
second portion of the loop outward and, with the loop placed over the tip,
into resilient gripping engagement with the inner face, so that the wire
and reed are assembled with a snap-on fit.
74. Apparatus as recited in claim 70, wherein the spring reed comprises a
Latin cross,t-shaped member having the plastic insert affixed to the top
of the t, above the crossarm, and the wire is coupled about the insert
above the crossarm.
75. Apparatus as recited in claim 74, wherein:
the insert has a generally rectangular perimeter about the top of the t;
and
the wire loop has a generally elliptical configuration with inner and outer
straight side legs shaped to fit the contours of the insert with an
expansion-spring fit.
76. Apparatus as recited in claim 75, wherein the insert comprises a
plastic tip molded about the upper end of the reed above the crossarm, the
tip having a groove for receiving and locating a portion of the wire loop
so that the wire loop fits on the tip with a snap-on fit.
77. Apparatus for moving a workpiece toward and away from a work station,
which comprises:
a spring reed comprising a Latin cross, t-shaped member of such material
and thickness that the body of the reed comprises a leaf spring;
means for mounting the reed so that the base of the t is fixed, the tip of
the t above the crossarm is free to flex toward and away from the work
station, and the crossarm of the t faces the work station and extends in a
direction generally perpendicular to the line of flexing of the reed;
means for mounting the workpiece to the tip of the reed so that the
workpiece moves toward and away from the work station on flexing movement
of the reed;
means for biasing the crossarm of the reed away from the work station to
hold the reed in a cocked position, in which the reed body is bowed to
store potential energy therein; and
means for releasing the bias when it is desired to actuate the workpiece,
the reed being so constructed and mounted that the bowed spring body of
the reed then takes over and drives the workpiece toward the work station.
78. Apparatus as recited in claim 77, wherein: the biasing means comprises
magnetic means for attracting the crossarm of the reed and magnetically
latching it in the cocked position, the reed being made of ferromagnetic
material so as to constitute a magnet armature; and
the means for releasing comprises means for demagnetizing the magnetic
means to a sufficient degree where it no longer is capable of holding the
associated reed in the latched position.
79. Apparatus as recited in claim 77, wherein the magnetic means is so
constructed and arranged that it acts as an electromagnet when attracting
the reed into the latched position and as a permanent magnet when holding
the reed in the latched position.
80. Apparatus as recited in claim 77, wherein the magnetic means includes:
a magnet core mounted parallel to the reed on the opposite side of the reed
from the work station and having spaced pole faces aligned with the ends
of the crossarm of the reed; and
electrical circuit means for magnetizing and demagnetizing the core.
81. Apparatus as recited in claim 78, wherein:
the reed comprises a relatively thin, flat plate; and
the stem of the reed tapers inwardly from the base of the reed to the
crossarm, with the narrowest portion of the stem being located just below
the crossarm, to minimize stress in the reed.
82. Apparatus as recited in claim 32, wherein: the reed mounting means is
so arranged that, in a neutral, unattracted condition, the reed inclines
forward from the base to tip toward the work station at an angle .theta.
from a reference plane perpendicular to the line of movement of the tip of
the reed.
83. Apparatus as recited in claim 82, wherein the magnetic means is so
arranged and the angle .theta. is so set that, when magnetically
attracted, the reed flexes rearward away from the work station and past
the reference plane so that the crossarm is inclined from the reference
plane at an angle .phi. when latched, with the reed stem bowed in a
retroflex curve.
84. Apparatus as recited in claim 83, wherein the angle .theta. is set
approximately equal to the angle .phi., the combination of the angles
.theta. and .phi. determining the amount of potential energy storable in
the cocked spring reed, given a particular reed material and geometry.
85. Apparatus as recited in claim 83, wherein the magnetic means includes a
pair of spaced pole faces mounted on the opposite side of the reed from
the work station and aligned with opposed areas at the ends of the
crossarms of the reed, the pole faces being bevelled away from the reed
and the work station at the angle .phi. set in accordance with the reed
geometry so that the opposed crossarm areas at the ends thereof lie flat
against the bevelled surfaces of the pole faces to magnetically seal the
reed crossarm against the pole faces with the crossarm closing the gap
between the pole faces.
86. Apparatus as recited in claim 78, wherein:
the magnetic means includes a pair of spaced pole faces mounted on the
opposite side of the reed from the work station and aligned with opposed
areas at the ends of the crossarm of the reed;
the reed mounting means is so arranged that, when magnetically attracted,
the reed body flexes away from the work station and the crossarm is
inclined at an angle .phi. from a reference plane perpendicular to the
line of movement of the tip of the reed; and
the pole faces are bevelled away from the reed and the work station at the
angle .phi., set in accordance with the reed geometry so that the opposed
crossarm areas at the ends thereof lie flat against the bevelled surfaces
of the pole faces to magnetically seal the reed crossarm against the pole
faces with the crossarm closing the gap between the pole faces.
87. An electromagnetic actuator, which comprises:
a magnet armature;
means for mounting the armature so that portions thereof are movable toward
and away from a work station along a line Y;
a magnet core comprising a generally flat plate having a base portion and a
pair of arms extending toward each other from the base portion so as to
define an air gap in the space between the inner tips of the arms, areas
of the arms adjacent to the inner tips constituting spaced pole faces of
the core;
means for mounting the magnet core adjacent to the armature on the opposite
side from the work station so that the core is generaly perpendicular to
the line Y and an inner, generally flat surface of the core plate faces
the armature and work station, the pole faces being aligned with portions
of the armature and being disposed at spaced areas along the inner surface
of the core;
means for selectively magnetizing and demagnetizing the core so that (1)
when the core is magnetized, it attracts the armature against the pole
faces to bias the armature to a retracted position, away from the work
station, and (2) when the core is demagnetized, the armature is
magnetically released; and
means for driving the armature forward toward the work station when the
core is demagnetized.
88. Apparatus as recited in claim 87, wherein:
the armature comprises a flat spring reed;
the armature mounting means is arranged for mounting the reed generally
parallel to the core so that one end is fixed and the other end is free to
flex toward and away from the work station and the core, the armature reed
having portions aligned with and overlapping the pole faces of the core so
that these portions are attracted to and magnetically latched against the
pole faces when the core is magnetized, the reed being further mounted so
that the b | | |
