US 3924528 A
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Description (OCR text may contain errors)
United States Patent [1 1 Ludin I I PRINTER  Inventor: Ludwig Ludin, Anglikon,
Switzerland  Assignee: Camille Bauer Messinstrumente AG,
Wohlen, Switzerland  Filed: Oct. 3, 1973  Appl. No.: 403,329
 Foreign Application Priority Data Oct. 6, 1972 Germany 2249125  US. Cl. l0l/93.l5; 101/93.29; 346/139 A;
346/141  Int. Cl. B41J 9/04  Field of Search 101/930, 93.15, 93.29;
 References Cited UNITED STATES PATENTS 3,300,017 l/1967 Yazejian et a1. 197/1 R 3,318,429 5/1967 Burns et a1 147/1 R N In 1 S h S d 11] 3,924,528 [451 Dec. 9, 1975 Kleinschmidt et a1. 101/93 C X 3,603,442 9/1971 Ward 101/93 C X 3,698,529 10/1972 Cattaneo.... 101/93 C X 3,742,846 7/1973 Knappe 101/93 C 3,780,650 12/1973 Meier l0l/93 C Primary ExaminerEdgar S. Burr Assistant Examiner-Edward M. Coven ABSTRACT with a given polarity to produce a deflection of one or more permanent magnets in the direction of the recording means to cause the print component to print thereon.
12 Claims, 2 Drawing Figures U.S. Patent Dec. 9 1975 Fig '1 US. Patent Dec.91975 Sheet 2 of2 3,924,528
PRINTER BACKGROUND OF INVENTION or other sheet recording support means. Print hammers are spaced at a distance from the support to the other side of the sheet support means, and an ink ribbon is arranged between the sheet and the type. The print hammers are pivotable about an axis running parallel to the line of print and are actuated by tappets which perform a translatory movement along their axis. The tappets are in turn actuated by a pivoting armature of an electro-magnet whose pivoting axis is arranged parallel to the axis of the print hammers. Several print hammers, tappets and electromagnets are provided. A disadvantage of this type of device lies in the fact that the power transmission from the electromagnets to the print hammers takes place through several mechanical parts each of complicated design. At high printing speed these parts are exposed to considerable acceleration and forces which make wear at the joints and connections unavoidable. The efficiency of the arrangement is relatively poor. Further, multiple directional changes occur in translating rotary movement to linear movement and back again to rotary movement. On each such change in direction a portion of the force of the driving power of the electromagnet is lost. Because of this, the electromagnet has to be made relatively strong and large. A large control output is necessary to operate the electromagnet. As a result, the response constant of the electromagnet is greatly increased having a disadvantageous effect on the speed which can be attained for printing. Another disadvantage lies in the fact that the rate of response of the electromagnet is relatively slight since the armatures have to be constantlymagnetized and demagnetized. Another drawback resides in the fact that due to the large number of engaging and connecting points between components a considerable degree of noise is produced which results in a troublesome noise level for the operator unless sufficiently dampened or insulated. Finally, this type of apparatus requires complicated correction devices to compensate for chordal error. This error arises because a print is provided for several printing spaces or gaps. The necessary adjustment is made by slewing or angularly positioning the hammer along a circular path.
Printers are also known, for use in conjunction with measurement recording devices which are in the form of curve-recording-dot printers by means of which electrical measurements are expressed as curve dots or other symbols. As the printing unit, these well known printers have a chopper bar or a printing drum. Besides the curve dots, additional symbols, e.g. numbers allotted to a measuring point, can also be printed. These well known printers nevertheless perform very complex mechanical movements which require a very complicated and accurate manufacture of the individual parts- Furthermore, in the printing operation considerable forces have to be transmitted, so that the use of relatively strong parts is needed. This presupposes the structure of large masses, whereby undesirable inertia is created leading on the one hand to considerable wear and on the other hand to a relatively slow printing sequence. These well known printers are therefore only suitable for recording slowly variable factors.
It is the object of the present invention to provide a graphic recording device and printer therefor overcoming the numerous disadvantages and difficulties found in the prior art devices.
It is a further object of the present invention to provide a printer of the type described in which a higher printing speed ispossible, with fewer moving parts and with considerably smaller masses to be moved.
These objects, other objects and the numerous advantages of the present invention will be apparent from the following disclosure.
SUMMARY OF THE INVENTION According to the present invention a graphic recording device is provided in which a plurality of printing components are attached to a movable transport extending along the line of printing with respect to a recording means. A permanent magnet is secured to each component and an electromagnet is fixed in spaced relation to the permanent-magnet between the transport and the recording means. The permanent magnets have their polarity varying alternately from component to component. The electromagnet is selectively excited with a given polarity to thereby produce a deflection of the permanent magnet and the component. Preferably, the electromagnet comprises a pair of opposed poles lying in the direction of the line of print, one of the poles being provided with an exciter winding which is connected to a control device which emits a direct current pulse of selected polarity in response to a given signal from the measuring device, or other source to be graphically recorded.
Preferably, the print componentscomprise a type face attached at one end of a resilient, spring-like arm, which is secured at its other end to the transport, the arm extending cantilevered therefrom in a direction normal or perpendicular to the direction of movement of the transport. The transport may be in the form of a continuous belt and/or chain conveyor.
According to one form of the invention, several electromagnets are provided whose air-gaps are arranged in parallel planes offset between the transport and the recording device and correspondingly offset permanent magnets are allotted to each electromagnet on selected print components. In this way the number of symbols that can be printed at any one time can be increased.
The printing is recorded on a sheet of paper or the like which is supported on a roller or spaced roller transport device and is movable in a direction normal to the movement of the print component transport. By selectively moving each with respect to the other, in well known and conventional manner, the print may be made on the recording sheet at selected graphical coordinates.
In well-known printers the ink support or ribbon is provided immediately at the point of printing. This is often undesirable, because this zone is not readily accessible and the ink support has to be occasionally changed or re-inked. Moreover, when the recording sheet support is inserted the latter may come to rest on the inking support, and thereby become undesirably inked or soiled. In a form of carrying outthe present invention, therefore, at least one further electromagnet, arranged away from the printing point, is provided for inking the printing components. The inking vehicle is therefore also arranged away from the printing point,
and the printing component is inked and then printed. To produce the movement of the printing component towards the inking support or vehicle, the further electro-magnet is provided.
In the preferred form of utilizing the invention, the printer is in the form of a recording instrument for the dot or symbol recording of one or more variable measurement factors. Each measuring factor is represented by a curve composed of dots and the individual dots can have shapes deviating from each other, for instance in the form of a dot, cross or circle.
Full details of the present invention are given in the following description of several practical embodiments thereof and in the accompanying drawings.
BRIEF DESCRIPTION OF DRAWING DESCRIPTION oF TIIE'INVENTION In the embodiment of theinvention depicted in FIG. l, the printer comprisesa transport 1 shown in the form of a continuous belt conveyor. The transport may be a belt'or a chain, entrained over suitable means, not depicted here-since the same are well known to those in this art. The transport is adapted to move linearly or be reciprocated along the direction indicated by the arrow X. Extending cantilevered from the transport 1 are a plurality of supporting arms 8 (only twoare shown). The arms 8 are resilient and extend perpendicular to the line of movement of the transport. The arms may be secured to the transport by any suitable known means depending of course on whether the transport is a belt, chain or is in another. form. A permanent magnet 2 is secured on each arm 8. The arm 8 may extend through the magnet and be retained either by suitable screw means, adhesive welding,'etc. The permanent magnets 2 are bar magnets and are arranged so that their polarity alternates from one to the other, adjacentmagnets having opposing polarity. The polarity indicated in the drawing are illustrativeand not necessarily restrictive.
' An electromagnet having opposing pole cores 3a and 3b, aligned with the permanent magnets 2 is arranged adjacent the transport 1. The cores 3a and 3b are spaced so that the magnets 2 pass freely between them. One core of the electromagnet is provided with an exciter winding 4 which on receipt of a current pulse excites the associate core with selected polarity. The pole core may be made of soft iron or the like. The exciter winding 4 is connected to a control device 4a which may include pulse generator, relay or similar device by which a direct current pulse is produced in response to an external stimuli. Such devices are not shown herein as they are well known in the art. Any suitable control device may be used. I
The magnets 2 are preferably bar magnets having theiraxis of polarity normal to the, arm 8 and lying in the vertical plane formed between the pole cores 3a and 3b. The use of a permanent magnet creates adynamic system in which the active component, i.e. magnets 2, is continuously magnetized and deflected merely on modification of the flux field.
A printing component 5 is secured to the free end of each of the arms 8. The printing component carries the character, or type to be imprinted; for instancea dot or other symbol such as a cross, zero or standard letter or number type. The print component 5 is arranged to one side of an ink ribbon 6 which lies above a record sheet 7 such as an endless paper strip or the like. The sheet 7 is entrained over a roller which acts as a platen for the print component 5.* The sheet is driven to move in a direction indicated by the arow Y, normally i.e. perpendicularly, with respect to the line of travel of the transport 1.
The supporting arms 8 are preferably made of flexible spring material, such as leaf or bar springs. The attachment of the arms Q to the transport 1 also preferably is provided with a degree of flexibility or elasticity, depending of course on the nature of the transport. The arms 8, however, must extend outwardly sufficiently rigidly so that the printing component remains in a sub stantially fixed position with respect to the transport. Therefore, if the attachment to the transport is elastic, the arm must be less so and vice versa.
As will be obvious, the print components 5 move in a straight line of print, parallel to the direction of travel X of the transport 1, while the record sheet 7 moves in a direction Y perpendicular to it. Thus on proper control or indexing of the transport and the record sheet the print component can be made to print a symbol on the sheet at a given graphical horizontal and vertical set of coordinates, as indicated by the pattern of dots, seen on the sheet 7. Thus printing is accomplished by selectively exciting the winding 4 with a given polarity so as to repel the permanent magnet of the selected print component and deflect it downwardly against the ribbon 6, and sheet 7.
The entire arrangement is preferably of such dimensions, that there are always two permanent magnets 2 of opposite polarity in the air gap of the electromagnet at the same time. By an appropriate choice of the polar ity of a control signal passed'to the exciter winding 4', one of the permanent magnets 2 andtherefore one of the printing components 5 for the printing operation can be deflected downwardly, while the other is deflected upwardly. This leads in practice to doubling of the pressure frequency, in comparison to those devices in which there is only a single permanent magnet in the zone of the electromagnet. It is of course also possible to arrange the system in such a way that there is only one permanent magnet at a time inthe air gap of the electromagnet.
The permanent magnets 2 have relatively small dimensions when a material of highcoercivity or permeability is used, as for instance samarium oxide. As a result the mass of the supporting arms 8 and also that of the printing components 5 can be relatively slight.
.Thus, the printer described has extremely low mass inertia, providing a further increase in the printing frequency and speed in relation to well known printers of thisvtype is furnished.
With the use of the printer as a type printer, i.e. to provide anon-coded or coded message, the printing ,type or characters can be arranged in a determined se- With the use of the printer as a graphical recording device, in which the outline of the curve of one or more measuring factors is to be recorded as a function of time, the printing components are provided with simple symbols, for instance dots, triangles, circles etc. In this case also the transport device 1 may take any form, for instance that of a revolving belt. In the case of the simultaneous determination of several measuring factors, a printing symbol is allotted to each measuring factor, and in this example, by meansof a suitable control device that isnotshown here, coordination between the printing symbols and the measuring factor and the correct printing moment are fixed.
It is finally possible to combine both type printers and recording printers with one another, so that for instance on the edge of a recording strip that is moved on as a function of time, the clock time and/or the number of a measurement point and/or other alphanumerical characters can be expressed, while at the same time the curve outline of the measuring factors is recorded in the form of dots. (See FIG. 2):
The transport device, in particular when it is in the form of a conveyor belt, can itself contain coding, for instance punched coding after the manner of the well known punched strip, with the help of which the required printing components can be selected for printing, by a signal generator, computer or the like.
It is also possible to arrange the inking ribbon 6 at another point of the printer, especially in the zone out of reach of the record sheet 7. That is, an inker may be arranged along the path of travel of the print. Components and an auxiliary electromagnet are provided by which the printing components are first deflected on the inker, and thus prepared for the actual printing operation. This measure dispenses with the often unpleas ant manipulation of an inking ribbon, in the actual printing zone. The separate inker may be a ribbon, well or other device.
The special advantage of the printer according to the invention resides in the fact that it makes it possible to attain a very high printing speed. This is on the one I hand, due to the fact that the number of moving parts and the size of the masses moved are very small. Moreover, no change in power direction is needed to move the magnets. The driving power can also be kept low since losses associated with changes of the direction of the force are avoided. Finally, through the electrodynamic drive system that is used according to the invention, in contrast to the electromagnetic driving systems heretofore known an additional increase in the operating speed is possible. The armatures do not have to be constantly magnetized and demagnetized. As the excitation output can be reduced in relation to the wellknown printer due to the reduced energy requirement, not only is a reduction in the pulse output possible; it is also possible to obtain a quicker printing sequence, because the poles of the electromagnets to be magnetized can be reduced in volume. A very special advantage also resides in the fact that the printer according to the invention operates very noiselessly. It does not there'- fore require sound proofing, nor will it annoy persons present in the same room.
In FIG. 2 a further practical example of a printer is described, in which the printing components are arranged in considerable density along the transport device 23. According to the principle of the example previously described there may only be a single, permanent magnet with a determined polar direction, in the air-gap of the electro-magnet. According to the practical example of FIG. 2, several electromagnets 21 and 22 are provided, (two are shown) whose air gaps are arranged on planes A and B running in the direction of the transport device 23 and the recording track 24. At the same time, the poles of the electromagnets extend thewidth of sheet 25 either wholly or partially. If the width of sheetis entirely covered, a-printing operation can be carried out at any point of the strip of paper. If there is only partial overlap, printing is of course only possible for the zone covered.
The permanent magnets attached to the supporting arms are therefore coordinated in pairs to the different electromagnets, according to the arrangement of FIG. 2. The pair of permanent magnets 26a is therefore arrangedat the plane A corresponding to the first electromagnet while the pair of permanent magnets 26b is arranged on the plane B of the second electromagnet. In thisway the result may be obtained, according to FIG. 2 where printing components 27a, which are allotted to the pair of permanent magnets 26a and the electromagnet 21' covering the full width of the paper, are arranged on plane A and print throughout the width of the sheet typecharacters, e.g. figures, while with the same transport device other printing components 27b, which are allotted to the pair of permanent magnets 26b and the electromagnet 22 on the plane B, record in the form of dots the curve of the measurements. It is of course also possible to provide other such groups of magnets to print any indicia desired. It is not necessary here for the poles of all the electromagnets to extend throughout the length of the line of writing although the printing type to be printed and actuated by this electromagnet do not have to be printed throughout the whole width of the recording support.
In general, the arrangement shown in FlG. 2 comprises components designed and combined in the manner described in connection with FIG. 1. Several other changes, modifications and embodiments will be obvious to those skilled in this art. The description therefore is to be taken as illustrative only and not limiting of the scope of the invention.
What is claimed is:
l. A printer comprising a plurality of deflectable printing components and a recording means, each of said components being attached to a movable transport means adapted to sequentially carry said printing components in a path extending along a line with respect to said recording means, a permanent magnet attached to each of said components to move conjointly therewith and an electromagnet fixed in spaced relationship to the line of movement of said permanent magnets, said permanent magnets being adjacent said recording means, said permanent magnets having their polarity varying alternately from component to component, and means for selectively exciting said electromagnet with a given polarity to produce a force field on at least one permanent magnet to thereby cause deflection of selected printing components in the direction of said recording means to cause said print component to print thereon.
2. The printer according to claim 1 wherein said electromagnet comprises a pair of spaced poles providing an air gap therebetween in which said permanent magnet may move, said poles having a length such that the gap extends over the permanent magnet of at least one printing component, and an exciter winding arranged about at least one of said poles.
magnets of each of the associated sets are coordinated 3. The printer according to claim 2 including means for producing a direct current pulse of selected polarity in said exciter winding.
4. The printer according to claim 2 wherein said printing components are spaced along said transport means with respect to each other a distance whereby the permanent magents of at least two of said printing components pass through said air gap between the poles of said electromagnet at the same time.
5. The printer according to claim 1 wherein each of said printing components comprise an elongated resilient arm having printing means at one end and being thereto.
8. The printer according to claim 1 wherein said transport means comprises an endless conveyor and said printing components are circulated past said recording means. I
'9. The printer according to claim 1 including an ink carrier arranged between said printing components and the recording means to transfer ink to said recording means on deflection of said printing components.
10. The printer in accordance with claim 1 wherein each of said printing components is provided with a predetermined symbol.
v 11. The printer according to claim ,10 wherein said recording means comprises an elongated sheet movable in a direction normal to the movement of said transport means and means for moving said sheet.
' 12. The printer according to claim 1 including an ink carrier spaced from said recording means alongthe path of travel of said printing components and one of said electromagnet being operable on excitation. to deflect said printing components toward said ink carrier to be inked thereby. l