FR2536701A3 - SHUTTER TYPE POINT LINE PRINTER - Google Patents

Abstract

ONE PERFECTED SHUTTLE-TYPE POINT LINE PRINTER INCLUDES SHUTTLE 26 HAVING MULTIPLICITY OF NEEDLES AND DRIVEN IN SENSITIVELY SINUSOIDAL ALTERNATIVE MOVEMENT, MOTOR 28 HAVING MAIN SHAFT PORTION 28A AND SUPPLEMENTARY 28B SHARE OF 28B AND ON THE OTHER OF THE MOTOR SHAFT, A FLYWHEEL 38 MOUNTED COAXIALLY ON THE MAIN SHAFT PORTION OF THE MOTOR AND ALLOWING TO ABSORB THE FLUCTUATIONS OF THE LOAD APPLIED TO THIS SHAFT, A CRANK 30 FIXED THROUGH THE FLYWHEEL ON THIS MAIN SHAFT PORTION, A LINK 32 OF WHICH ONE END IS CONNECTED TO CRANK 30 AND THE OTHER END IS CONNECTED TO SHUTTLE 26. A COUNTERWEIGHT 40 IS CONNECTED THROUGH THE FLYWHEEL TO THE MAIN SHAFT PORTION BY THE INTERMEDIATE OF A CRANK 42 AND OF A CONNECTING ROD 44 AND IS MOVING IN AN ALTERNATIVE MOVEMENT IN AN OPPOSITE DIRECTION FROM THE SHUTTLE; AS A RESULT, THE INERTIA FORCES OF THE SHUTTLE AND OF THE WHEEL CANCEL.

Description

Printer by shuttle type dot line.

  The present invention relates to a line printer

  shuttle type points, and more particularly a print

  mantis by line of points with a shuttle system, in the-

  which shuttle has a multiplicity of needles and is driven in a perpendicular transverse movement

  to the direction of arrival of the printing paper.

  We know such a printer by line of dots, in

  which the needles are projected towards the printing paper

  pressure according to predetermined printing information

  Born in such a way that the required character images can be formed by a multiplicity of dots, various types of information equipment adopt the dot printer as the output printing device. such a dot printer, in which a multiplicity of needles are arranged along a line of the printing paper, equidistant from the

  of each other, and are driven in an alternating movement

  tif corresponding to the pitch of the needles to perform a

  printing on paper arriving in perpetual direction

  specific to this reciprocating movement, such a printer being able to carry out printing by line at high speed and with a large capacity.

  in which are arranged, along a line, a multipli-

  city of needles, which are drawn in a movement

  alternatively corresponding to the pitch of the needles, is called "shuttle", this type of printer is known

  name "shuttle line printer of dots".

  In this type of printer, the fact that the shuttle is driven in a linear reciprocating movement by a motor by

  through a crank mechanism, and that the turnip

  comprising you both a multiplicity of needles and the solenoids moving these needles thus has a great inertia, the fluctuations of the load applied to the motor during reversals of movement of the shuttle become significant and a torsion occurs in the rotating shaft of the motor In addition, in the reciprocating movement of the shuttle, in particular during reversals of movement in one direction and the other, the increase in the load exerted on the frame is so great that the high speed drive of the shuttle causes large vibrations throughout the printing system. In an attempt to reduce these fluctuations in the load applied to the motor during reversals of movement in one direction and the other of the shuttle in the known device: prior described in US Pat. No. 3,768,403, a system has been proposed. transmission having drive belt means and reversing cam means in the conventional improvement of the shuttle type dot line printer, in which the motor is coupled to the shuttle by means of drive belts drive and reversing cam means, as described in US Patent No. 3,941,051 However, this prior device

  raises certain problems, namely that this printing system

  mantis requires a largely dimensioned frame having a part

  heavy mobile so print noises are important

  tants and that the life of the printer itself is short The last cited US patent also raises a fundamental problem as regards the precise positioning of the printing, because of the impossible elongation

  to measure drive belts.

  Other known devices, described in US Pat. Nos. 3,789,969 and No. 3,833,891 show different types of prior shuttle printers. However, in these printers, it is very difficult to adjust the times.

desired printing.

  In addition, in the shuttle line dot printer of the prior art, because the shuttle has a unitary structure and the needles are attached

  on the face of the shuttle facing the printing paper

  cannot easily detach the needles from the shuttle and this raises problems for disassembly

and reassembly for maintenance.

  It is therefore a general aim of the: present invention to provide a printer by line of dots of the small shuttle type, in which a steering wheel is

  fixed on a main shaft portion of the engine for ab-

  absorb fluctuations in the load applied to the motor shaft.

  In accordance with the teachings of this invention

  tion, this goal is achieved in a line printer of

  shuttle type points causing a shuttle in a movement

  horizontal alternative perpendicular to the direction of arrival of the printing paper and projecting needles arranged in line in the shuttle in the direction of the paper

  so that you can form the character images

  sought after, this improved printer comprising a shuttle having a multiplicity of needles and being enttait = born in a substantially sinusoidal reciprocating motion, a motor having a main shaft portion and an additional shaft portion on both sides of a motor shaft, a flywheel mounted coaxially directly on the main shaft portion, a crank attached to the main shaft portion of the motor via the flywheel, a connecting rod one end of which is rotatably mounted on the crank and of which the other end is connected to the shuttle by a pin, and a shuttle position detector mounted on the additional shaft portion and detecting the position of the shuttle by detecting the

  engine rotation, the flywheel being able to absorb fluctuations

  of the load applied to the motor shaft

  The invention will be better understood on reading the description.

  detailed description, given below by way of example only, of several preferred embodiments, in conjunction with the attached drawing, in which FIG. 1 is a perspective view of a dot-line printer of the shuttle type according to a first realization of the present invention;

  FIG. 2 is a perspective view, with parts broken away;

  tiel, showing a main part of figure 1;

  FIG. 3 is a sectional view showing a removable connection

  ble between a needle head and a needle head holder; and Figure 4 is a perspective view of a printer by

  shuttle line _ of a shuttle type according to a second realization

tion of the present invention.

  Referring more particularly to the drawing, FIG. 1 is a perspective view of a dot-line printer of the shuttle type according to the first embodiment of the present invention and FIG. 2 is a perspective view, with partial cutaway, of 'a main part of figure 1.

  A plate 16 is pivotally mounted on side plates.

  rails 12 and 14 which are fixed on a frame 10, and a paper

  18 is mounted along the surface of the plate

  tine 16 The printing paper 18 is held by paper guides 20 and 22 cooperating with the marginal perforations on the two edges of the paper The rotation of a feed shaft 24 makes the paper advance according to arrow A.

  A shuttle 26 is installed on the frame 10 so that

  see being driven in a horizontal reciprocating movement in directions B and C, perpendicular to the direction of arrival of paper A; the shuttle 26 performs this reciprocating movement in a substantially sinusoidal manner thanks to a

  crank mechanism which will be described below A multi-

  plicity of needles (not shown) are arranged in

  line in shuttle 26 and can be projected directly

  tion of the printing paper The impact of the needle required on the printing paper 18 allows a clear and uniform printing in the direction of the line through

  an ink ribbon or the like on paper 18 The

  sembles of needles and born drive solenoids are

  not shown in detail in the figures, but each ai-

  guille is created in the same way as in the print

  mantis by conventional point line.

  In order to drive the shuttle 26 in its alternating movement

  tif in,: directions B and C, alternative drive devices are installed in the system, for example a

  crank mechanism, cam mechanism, linear motor

  re, etc. In the figure, the motor having a main shaft portion 28 a and an additional shaft portion 28 b, each portion being disposed respectively on one side of the solid rectilinear shaft of the engine, is fixed to the frame by a motor support 29 The motor 28 is coupled to

  the shuttle 26 by means of a handling mechanism

  velle, which transforms the rotational movement of the motor

  28 in an alternating movement to drive the shuttle 26.

  This crank mechanism comprises a crank 30 fixed to the main shaft portion 28a of the motor 28, and a connecting rod 32, one end of which is connected to the crank 30 and the other end of which is connected to: the shuttle 26 Consequently , the shuttle 26 is driven in an alternating movement in the directions B and C by means of labièl, 1 e 32 depending on the rotation of the motor 28. On the other hand, the shuttle 26 has guide holes 36 a and 36 b and a rectilinear guide shaft 34 is mounted on the frame 10 so that the cooperation of the guide holes 36 a and 36 b and of the guide shaft 34 pivotally keeps the shuttle 26 and allows it to to be trained

  precisely in directions B and C Regarding

  identifies the rectilinear guide of the shuttle 26, it is possible to use

  use sliding guides, leaf springs: parallel, etc., in place of the above-mentioned straight guide shaft 34

  and guide holes 36 a and 36 b.

  The present invention is characterized in that a steering wheel is

  mounted coaxially directly on the shaft portion-, main-

  28 a motor 28 The flywheel 38 can absorb fluids

  charge kills applied to the main shaft portion

  28a of the motor shaft In other words, the na-

  vette 26 has a multiplicity of needles inside

  and needle actuators to operate these

  last; the drive section is used as a bench

  strike and is therefore very heavy In the movement

  alternative of shuttle 26, especially during reversals

  movement in one direction or the other of the shuttle 26, the fluctuations in the load on the motor come to be large, but, in the present invention, the flywheel 38 mounted on the main shaft portion 28 has

  motor 28 can absorb these fluctuations in the load applied

  quée on the main shaft portion 28a of the motor 28.

  In the first realization, in order to absorb the fluctua-

  of the load applied to the motor shaft 28 by an opposing force, a counterweight 40 is driven in the reciprocating movement in the opposite direction to the movement of the

  shuttle 26 at the same time In other words, a second

  crank 42 is mounted on the main shaft portion

  28 a of the motor 28, and the counterweight 40 is coupled to the two

  10th crank 42 by a second connecting rod 44 Consequently, the shuttle 26 and the counterweight 40 move at the same

  moment of a reciprocating motion, but in directions-

  opposite ,, and''the counterweight 40 constitutes a system of equi-

free space for the shuttle 26.

  Consequently, the use of the opposing force of the

  counterweight 40 can cancel the force of inertia and acceleration

  ration from shuttle 26 and can absorb

  load fluctuations applied to the motor shaft 28.

  In addition, a rectilinear guide shaft 45 a is fixed on the frame 40 and guide holes 45 b and 45 c are formed in

  the counterweight 40 and cooperate with the guide shaft rec-

  tiligne 45 a The counterweight is kept pivotally by

  the straight guide shaft 45 a and through the guide holes

  45 b and 45 c so that they can be trained

  precise in directions B and C in an alternating movement

  native in the same way as the shuttle 26 -

  In the present invention, in order to detect the position of the shuttle 26 by determining the rotation of the motor 28, a shuttle position detector 46 is mounted on the additional shaft portion 28 b of the motor 28 and presents along of its circumference, a multiplicity of slots In addition, a photo-switch 48 is fixed on the frame 10 in

  vis-à-vis the shuttle position sensor 46 Consequently

  quence, the precise electrical detection of the position of

  the shuttle in its reciprocating movement by means of the detector

  position switch 46 and photo-switch 48 can provide

  rer better printing operation.

  Consequently, according to the present invention, it must be

  clearly understood that the motor shaft directly supports the

  lant 38, connected to crank 30 to absorb fluctua-

  tions of the load applied to the engine via the crank means, and the engine 28 can be arranged very close to the flywheel 38; consequently, the torsion of the motor shaft is practically eliminated and the position detector 46 can follow the rotation of the flywheel 38 with great precision to detect the position of the shuttle.

26 without error.

  Furthermore, because the position detector 46 is available

  dried in the front part of the frame 10 in this embodiment, in order to be mounted on the additional shaft portion 28 b, the manual adjustment of the position of the detector 46 or of the

  photo-switch 48 can be easily performed.

  Furthermore, in this first embodiment of this

  invention, the regulatory action of the steering wheel and the anti-

  gonist; supplied by the counterweight can absorb

  fluctuations in the load applied to the motor in the movement

  alternative to the shuttle, in particular to reversals of movement in one direction and the other. Consequently, this dot-line printer of the shuttle type can be produced in small dimensions and be light, no twisting occurring in the rotation shaft of the motor and no excessive load being applied to the bearings of the rotating shaft Due to the absence of torsion in

  the motor shaft, and the fact that the motor runs smoothly-

  The detection accuracy of the shuttle position sensor can be increased and the position of the shuttle can be accurately detected. Furthermore, because the position sensor is mounted on the additional shaft portion of the motor, it is accessible from the side opposite the shuttle and it can be assembled and adjusted

very easily.

  The present invention is further characterized in that the shuttle has a straight guide section, and comprises

  print head holders coupled to an input mechanism

  reciprocating and print heads on them-

  which needles are mounted, arranged in line on the printing head portets; in addition, the print heads

  sion are removably attached to the print head holders

  pressure In the production, the print head is

  tée on the printhead holder by a fixing screw held on the printhead holder when the fixing screw is detached from the printhead Figure 3

  is a sectional view of the shuttle 26 and the removable assembly

  ble of the print head and the print head holder

  now be described with reference to this figure.

  In FIG. 3, the shuttle 26 has a rectilinear guide section constituted for example by the guide holes

  36 a and 36 b; it is made up of print head holders

  sion 50 coupled to the other end of the aforementioned connecting rod 32, the print head 52 being mounted on the print head holder 50 The needle, not shown, is aligned

  on the print head 52 facing the printing paper

  pressure 18 The fixing screw is used to fix amo-

  the print head 52 on the print head holder This fixing screw is constituted by a male threaded shaft portion 56 and a through shaft portion coaxial with the threaded portion 56, and having no thread A female threaded hole 60 is formed in the print head 52% to cooperate with the male threaded portion 56 and an opening 62 is also formed in the print head, coaxial with the aforementioned hole 60; the threaded portion 56 of the fixing screw 54 can pass freely through the opening 62 In addition, a female threaded hole 64 is formed in the print head holder 50 and the male threaded portion 56 of the fixing screw 54 can cooperate with

this hole 64 and pass through.

  When the print head 52 is fixed on the print head holder 1 O 5 p, the male threaded portion 56 of the screw

  fixing 54 firstly cooperates with the tapped hole fe-

  melle 64 from the printhead holder 50 and passes through

  the opening 62 of the print head 52 to come cooperate

  rer with the female threaded portion 60 The cooperation of the threaded portion 56 of the fixing screw 54 with the hole

  threaded 60 of the print head 52 fixes the print head

  sion 52 on the head holder 50 When the head 52 is released from the head holder 50, the male portion 56 of the fixing screw 54 is detached from the tapped hole 60 of the print head 52 At this time, in the embodiment shown, the male threaded portion 56 of the fixing screw 54 cooperates with the female tapped hole 64 and the fixing screw is not detached from the head holder 50 when the male portion 56 of the fixing screw 54 is released from the tapped hole female 60

  print head 52 Consequently, in this realization

  When the fixing screw 54 is released from the printhead 52, it remains with the printhead holder. The removable assembly of the printhead 52 and the printhead holder 50 therefore constitutes an upgrade

important in operation.

  As described above, according to the invention, the print head is mounted on the print head holder by the fixing screw and the fixing screw can remain with the print head holder when she is free from

printhead.

  FIG. 4 shows a dot-type printer of the shuttle type according to the second embodiment of the present invention. In FIG. 4, the same references designate the

  same elements as in FIGS. 1 and 2 and their descrip-

tion will not be repeated.

  In the second embodiment, in the same way as in the first embodiment, the flywheel 38 is mounted coaxially directly on the main shaft portion 28a of the engine.

  28 and this flywheel 38 absorbs fluctuations in the load applied

  quée on the main shaft portion 28a of the motor 28 during the reciprocating movement of the shuttle 26, in particular during reversals of movement in one direction and in the other. In addition, the second embodiment is characterized in that the shuttle 26 is constituted by two separate shuttle parts, 70 and 72, which are respectively installed in accordance with each half, right and left, of the printing paper 18 These two parts shuttle 70 'and 72 are

  arranged parallel to the direction of the alter-

  native and they are respectively and simultaneously ', entered I-

  born in alternative movements in opposite directions

  ses, 3 and B 2, and C 1 and C 2 The inertial forces in each

  one of the two shuttle parts 70 and 72 are equal so that the reciprocating movements in the opposite directions cancel the inertia loads of the two parts

  shuttle 70 and 72 and that the load fluctuations applied

  the main shaft portion 28 has the engine 28 may

  These shuttle parts 70 and 72 are held by shuttle supports, 74 and 76, fixed on the frame 10, and the shuttle supports 74 and 76 serve to

  bearings in the respective alternative movements.

  In order to drive the two aforementioned shuttle parts in alternating movements in the respective directions B 1, C 1, B 2 and C 2, the motor 28 is fixed on the support 29 of the frame 10 A crank 30 and a second crank 42 are fixed to the main shaft portion 28a of the motor 28 via the flywheel 38; they are respectively connected to a connecting rod 32 and to a second connecting rod 44 and the rotation of the main shaft portion 28a of the motor 28 is thus transmitted to the two shuttle parts 70 and 72

  so as to animate them with a linear reciprocating movement.

  In other words, in the second embodiment, in the same way as in the first embodiment, the crank 30 and the second crank 42 are fixed to the main shaft portion 28a of the motor 28 by means of the flywheel 38 , and the crank 30 is coupled to the aforementioned shuttle part 70. The second connecting rod 42 is connected to the preactivated shuttle part 72 by means of the second connecting rod 44 Consequently, and as a function of the rotation of the portion of main shaft 28 has the motor 28, the crank and the associated connecting rod 32, and the second crank 42 and

  the second associated connecting rod 44 'have their synchronous movements

  so that the two parts of the shuttle separate

  rees 70 and 72 are driven simultaneously in reciprocating movements in opposite directions, respectively Bl and B 2, and C 1 and C As described above, in the second embodiment, because the shuttle is constituted by two separate shuttle parts, driven simultaneously in reciprocating directions in opposite directions, and both

  parts of the shuttle have the same weight and the same inertial force

  tie, and are driven in alternating movements synchronized in opposite directions, the fluctuations of the load applied to the main shaft portion of the

  motor can be absorbed during these alter-

  native, in particular during reversals of movement in one direction and in the other, in the same way as in the first embodiment In addition, in the second embodiment, each shuttle portion is short in comparison with the unitary shuttle of the prior devices; this results in little deformation during manufacture, little thermal deformation, etc. As has been described hitherto, according to the present invention, it is advantageous that the torsion of the motor shaft is

  practically eliminated by the fact that the means of driving

  engine and the shuttle means are arranged in the vicinity of each other, and the position detector

  of the shuttle can be easily adjusted to fix its position

  tion preferred by means of detection on the frame.

  In addition, according to the invention, a print head can be fixed without any difficulty on the drive mechanism of the shuttle or be detached therefrom. It is also advantageous that the steering wheel can absorb

  fluctuations in the load applied to the rear portion

  main bre of the motor and that there is no torsion of the rotating shaft of the motor during the random movement of the shuttle, in particular during reversals of movement in one direction and in the other It is also advantageous that there are no excessive loads applied to the bearings of the rotating shaft and that one can obtain a printer by line of dots of the shuttle type of small size and light weight Because there is no twist in the rotating shaft of the motor and that it rotates regularly, the detection accuracy of the position detector can be considerably increased

  shuttle As a result, it is advantageous to be able to detect

  ter precisely the position of the shuttle In addition, the motor has a main shaft portion and an additional shaft portion The shuttle position detector is mounted on this additional shaft portion

  and can be attached to the side opposite the shuttle.

  As a result, the position sensor can be easily mounted and adjusted. As described, the shuttle type dot line printer according to the present invention can be equipped with print heads which can be detached from the head holder

  As a result, it is advantageous that the needles

  them can be arranged in line in front of the paper

  easily assembled and maintained.

Claims (4)

Claims.   1 Printer per shuttle type dot line,   nant a shuttle in an alternating perpendicular movement-   laire to the direction of arrival of the printing paper and projecting needles arranged in line in the shuttle   toward the printing paper so that it can form   sea of character images: sought after, characterized by   what it comprises: a shuttle (26) having a multipli-   city of needles and driven in a substantially sinusoidal reciprocating movement; a motor '(28) having a portion   main tree (28 a) and a portion of additional tree   keep quiet (28 b) on each side of the motor shaft; a flywheel (38) mounted coaxially directly on the main shaft portion (28a); a crank (30) fixed to the main shaft portion (28a) of the engine via the flywheel; a connecting rod (32) one end of which is connected to the crank (30) and the other end of which is connected to the shuttle (26); and a shuttle position detector (46) mounted on the additional shaft portion and controlling the position of the shuttle by detecting the rotation of the motor, whereby the flywheel can absorb fluctuations in the load   applied to the main shaft portion of the engine.   2 Printer per shuttle line of dots according to the   claim 1, characterized in that a second mani-   velle (42) is mounted on the main shaft portion   (28 a) of the engine via the flywheel, that a counter   weight (40) is driven simultaneously in an alternating movement   tif in opposite directions to the shuttle (26), that a second connecting rod (44) is connected to the second crank at one end and to the counterweight at the other end, and that the motor is connected to this counterweight (40) via the second crank (42) and the second connecting rod (44),   whereby the counterweight balances the shuttle.   3 dot-line printer of the shuttle type according to claim 1, characterized in that the shuttle consists of two separate shuttle parts (70, 72)   so that these shuttle parts can print each   cune the right half and the left half respectively of the printing paper, these two separate shuttle parts being arranged parallel to the direction of the reciprocating movement and being respectively connected to the motor by means of cranks (30, 42) and connecting rods (32, 44) so as to be driven simultaneously in one movement   alternating in opposite directions, the forces of inertia   tie of the two separate shuttle parts canceling each other. 4 shuttle line dot printer according to claim 1, characterized in that the shuttle has a rectilinear guide section and comprises print head holders (50) coupled to a drive mechanism in an alternating movement and printheads (52) on which are mounted needles arranged in line on the printheads, and that these printheads   are removably attached to the printhead holders.   Printer per line of shuttle type points according to   claim 4, characterized in that each print head   pressure is mounted in a movable manner on the printhead holder by a fixing screw (54) and that, when this fixing screw is released from the printhead,   it remains with the print head holder.