US3844211A

US3844211A - Endless type support band for movable-type printing machine

Info

Publication number: US3844211A
Application number: US00876913A
Authority: US
Inventors: R Migoux; J Singery
Original assignee: Societe Industrielle Honeywell Bull
Current assignee: Bull SA
Priority date: 1969-11-14
Filing date: 1969-11-14
Publication date: 1974-10-29
Anticipated expiration: 1991-10-29

Abstract

The invention concerns an endless type support band intended for a printing machine, said band being provided, on one of its edges, with flexible strips referred to as fingers, which extend parallel to the axes of driving pulleys around which the band is stretched, each finger being provided, towards its free end, with a printing type in relief, said band also being provided with an endless strip, consisting of an elastomer and secured to the free end of the fingers in order to damp the vibrations produced in each finger as a result of the striking of said finger by a printing hammer.

Description

1451 Oct. 29, 1974 ENDLESS TYPE SUPPORT BAND FOR MOVABLE-TYPE PRINTING MACHINE Inventors: Robert Jean Migoux, Paris;

Jean-Michel Singery, Belfort, both of France Societe lndustrielle Honeywell Bull, Paris, France Filed: Nov. 14, 1969 Appl. No.: 876,913

Assignee:

US. Cl. 101/111, 101/93 C Int. Cl B41j 7/08 Field of Search 101/93, 111

References Cited UNITED STATES PATENTS 3,216,348 11/1965 Oldenburg et al. 101/111 X 3,402,657 9/1968 Potter et al. 101/93 C 3,416,442 12/1968 Brown et a1 101/93 C Primary ExaminerRobert E. Pulfrey Assistant ExaminerEdward M. Coven Attorney, Agent, or Firm-Fred Jacob [57] ABSTRACT The invention concerns an endless type support band intended for a printing machine, said band being provided, on one of its edges, with flexible strips referred to as fingers, which extend parallel to the axes of driving pulleys around which the band is stretched, each finger being provided, towards its free end, with a printing type in relief, said band also being provided with an endless strip, consisting of an elastomer and secured to the free end of the fingers in order to damp the vibrations produced in each finger as a result of the striking of said finger by a printing hammer.

10 Claims, 5 Drawing Figures PATENTEDnms 1974 3.84421 1- sum 20? 3 PAIENTEMBI 29 m4 SHEET 30$ 3 ENDLESS TYPE SUPPORT BAND FOR MOVABLE-TYPE PRINTING MACHINE The present invention concerns an endless type support band intended for use in a printing machine in which printing is effected by striking on-the-fly of a series of printing types moving continuously along a printing line, also known as a chain printer.

In a printing machine of this kind, a series of printing types in relief, equally spaced apart and secured to a movable support, are shifted at constant speed along a continuous path past a row of striker hammers disposed along a rectilinear and horizontal portion of the said path, this portion constituting the printing line. A paper sheet and an inked ribbon are disposed and advanced in known manner between the movable types and the striker hammers, the latter being adapted to be individually actuated in known manner at predetermined instants in order to print selected characters on a paper line.

Chain printers are known in which the types are fixedly mounted on an endless band stretched over two driving pulleys, the said band being provided, on one of its edges, with flexible steel strips, called fingers, which extend perpendicularly to the direction of travel of the band, each finger being provided, towards its free end, with a type in relief which is formed or welded on the said finger. Although this type support band may consist of a resilient belt formed with apertures in which the dogs are engaged and fixedly maintained, it is also possible to construct the said band in one piece, from an endless steel band, which is successively cut away at regular intervals, perpendicularly to one of its edges and over only a part of its width, so as to form fingers on the ends of which the printing types are formed.

With a type support band of this kind, the printing of the characters on the paper may be effected by individual displacement of the fingers of the band, by means of striker hammers, so that the said fingers become curved out of the plane of that portion of band which is situated opposite the printing line and come into contact with the inked ribbon in order to apply it to the paper. The curved fingers return to their initial position owing to their natural resilience. However, the return to the inoperative position of the fingers which have been displaced by the striker hammers produces in the said fingers rapid vibrations which, although of small amplitude, are harmful to the clarity of the impression, notably when fingers are again displaced by hammers while they are still vibrating. For this reason, in printing machines provided with such a type support band and operating at high speed, the printing of the characters preferably takes place by the application of the paper and of the inked ribbon by means of the striker hammers to the printing types provided on the fingers. In order to provide a support for the printing types during impact, each machine normally comprises a plate, called an anvil, which absorbs the shocks and which is disposed, at the level of the printing line, in parallel relationship to that portion of the band which travels past the hammers, and in proximity to that face of the fingers which is opposite to that situated opposite the hammers. However, even in this mode of printing, owing to the fact that the band is continuously driven and the printing types against which the inked ribbon and the paper are applied are stopped in their displacement for a very short time corresponding to the period of the impact, the fingers on which these printing types are situated undergo a slight flexure in a direction parallel to the direction of travel of the band. After the impact, the fingers which have thus been flexed return to their position as a result of their natural resilience. However, the return of the said fingers to the normal position again produces in these fingers very rapid vibrations which, in this case, take place in a direction parallel to the direction of travel of the band. These vibrations, which are generally very rapidly damped, are nevertheless very troublesome in high-speed printing machines and are often responsible for the printing of the characters out of their correct position, notably when a printing type which has been struck by one hammer is struck by the next hammer while it is still vibrating.

The present invention has the object of damping the vibrations produced in each finger as a result of the action of the striker hammers on the said finger.

One object of the invention concerns, in a printing machine in which the characters are printed by the actuation of striker members, an endless type support band comprising a flexible metal band stretched around two driving pulleys and provided, on one of its edges, with flexible strips or fingers which extend perpendicularly to the direction of travel of the band, the said fingers being identical and equally spaced apart, each finger being provided, towards its free end, with a printing type in relief, the said band being characterised in that it is also provided with an endless strip consisting of an elastomer and secured to the free end of the fingers in order to damp the vibrations produced in each finger as a result of the actionof the striker members on the said finger.

For a better understanding of the invention and to show how it may be carried into effect, the same will now be described, by way of example, and with reference to the accompanying drawings, in which:

FIG. 1 is a diagrammatic view in perspective of the printing mechanism of a machine provided with an endless band comprising fingers carrying printing types,

FIG. 2 is a fragment of an endless band of the type illustrated in FIG. 1, this band comprising an endless strip secured to the free end of the fingers,

FIG. 3 is a fragmentary sectional view of the printing mechanism of a machine provided with a type support band of the pattern illustrated in FIG. 2,

FIG. 4 is a sectional view of a fragment of a type support band, showing a second form of construction and arrangement of the endless strip, and

FIG. 5 is a view in perspective, partly in section, of a fragment of a type support band showing a third form of construction and arrangement of the endless strip.

In the printing mechanism illustrated in FIG. 1, an endless band 10 stretched around two

driving support pulleys

11 and 12 is provided, on one of its edges, with a series of flexible strips 13, called fingers, which extend parallel to one another in a direction substantially perpendicular to the direction of travel of the band, the direction of travel of the latter being, for example, that indicated by arrows in FIG. 1. The fingers 13 are identical and are regularly distributed over the whole periphery of the band 10. Each finger bears a printing type 14 in relief, which is disposed towards its free end, these printing types being situated on the outside face of the fingers and aligned, as perfectly as possible, in relation to one another in the direction of travel of the band. Thus, when the endless band is driven by the pulleys 11 and I2, the printing types 14 travel along a continuous path, past a row of striker hammers 15 mounted horizontally and disposed along a rectilinear and horizontal portion of the path followed by the printing types between the two

pulleys

11 and 12, this portion constituting the printing line.

The paper sheet intended to receive the impression consists of a paper web 16 guided by the two guide elements l7 and I8 and driven in known manner in a direction perpendicular to the direction of travel of the endless band 10 by feed members of known type, these feed members consisting, in the described example, of two

upper traction members

19 and 20 and two

lower traction members

21 and 22. These traction members which each comprise a belt or chain 23 provided with pointed projections 24 adapted to engage in marginal perforations in the paper web 16, are currently employed in printing machines for feeding the paper and for this reason will not be described in greater detail. However, the upper and lower traction members are mechanically coupled by means of pulleys 25 and a transmission belt (not shown) mounted on the said pulleys 25 to ensure that the said traction members are synchronously driven.

An inked ribbon 26 supported by supply and take-up spools denoted by 27 and 28 respectively is disposed at the level of the printing line, between the paper web 16 and the fingers l3 situated opposite the striker hammers.

The striker hammers 15, of which only two are shown in FIG. 1 for the sake of simplicity, are normally maintained out of contact with the paper web 16 by springs, one of which is illustrated and denoted by 29 in FIG. 3. These striker hammers may be selectively actuated by electromechanical actuating devices of known type. In FIG. 1, these actuating devices consist, for example, of electromagnets 30, of which the armatures 31 are fast with levers 32 rockably mounted on a pivot rod 33. When an electromagnet associated with a striker hammer is energised for a very short time by means of an electric pulse, this electromagnet attracts its armature, the result of which is that the corresponding lever 32 is rocked and this hammer is thrown towards the paper and the inked ribbon at a sufficient speed to apply the latter for a very short time against a printing type on the endless type support band. A plate 34, called an anvil, is disposed parallel to that portion of the band which travels past the hammers, at the level of the printing line and in proximity to that face of the fingers which is opposite to that situated opposite the hammers, in order to provide a support for the printing types when the paper and the inked ribbon are applied against them.

In the printing mcchanismjust described, the relative arrangement of the striker hammers, of the endless type support band, of the paper web, of the inked ribbon and of the anvil is similar to that indicated in FIG. 3, which is a fragmentary sectional view of the printing mechanism of a printing machine, this machine being provided with an endless type support band of the type illustrated in FIG. 2.

The endless type support band, of which a portion is shown in FIG. 2, consists of a flexible band 10 made of a material having high tensile strength and a high modulus of elasticity. In a preferred embodiment, this material is an iron-chromium-nickel alloy, known as stainless steel. The flexible band 10 is provided on its upper edge with fingers 13 which, in the described example, are made of the same material as the band 10. It will be assumed by way of example that the fingers 13 have been obtained from an endless steel band which is cut away, by an appropriate method, at regular intervals perpendicularly to one of its edges and over a part of its width, this part corresponding to the length of the fingers. In the described example, the width of each finger is about 2 to 3 millimetres, the fingers being about I to 2 millimetres apart. Each finger is provided with a printing type 14 in relief, which is situated in the neighbourhood of its free end, these printing types being situated on those faces which are situated on the same side, and being aligned as perfectly as possible in a direction parallel to the edges of the band.

FIG. 2 again shows that, in the described example, the lower edge of the band is formed with regularly spaced slots 35 to define synchronising fingers 36 serving to ensure the necessary synchronisation in the actuation of the striker hammers. For this purpose, the synchronising fingers 36 and the slots 35 are employed, as shown in FIG. 3, to intercept or allow the passage of a beam of light emitted by a light source enclosed in a casing 37 and transmitted to a photoelectric cell disposed within another casing 38. However, it is to be noted that the presence of the slots 35 in the endless band is not essential for effecting the synchronisation, it being possible for the passage of the light beam to be controlled by spaces present between the type support fingers. Likewise, the above-indicated photoelectric means may be replaced by other known means performing a similar function, for example such as magnetic means.

In order to damp rapidly the vibrations produced in the type support fingers, as a result of the action of the striker hammers on the said fingers, an endless strip 40 of synthetic material is secured to the free end of the fingers, this strip having the desired damping properties. Synthetic material of which this strip may suitably be made are elastomers of known type, such as, for example, polychloroprene or the elastomer known as butyl.

FIG. 3 shows that, in one embodiment, the endless strip 40 is secured to the face of the fingers which is opposite to that supporting the types serving for the printing, which may be done by previously covering with an adhesive gum that surface of the fingers which is to receive the said strip. In another embodiment, the said fingers may be secured by moulding the elastomer on the fingers. Finally, the type support fingers may be appropriately shaped to permit the mechanical engagement of the strip therein.

In another embodiment illustrated in FIG. 4, the endless strip 40 is secured to that face of the fingers which supports the printing types. However, it is to be noted that, in order to avoid the risk of interfering with the application of the inked ribbon and of the paper to the printing types, the thickness of the latter must be greater than that of the damping strip. Nevertheless, it is always possible, in order to obtain the desired degree of damping, also to secure another damping strip to that face of the fingers which is opposite to that on which the printing types are situated. This object may also be achieved by employing a U-shaped member consisting of elastomer on the end of the fingers, the

said member being secured to the two faces of the said fingers.

FIG. 5 illustrates another form of construction of the damping strip. The strip 40 illustrated in this figure is formed with apertures 41, the cross section of which corresponds substantially to that of the type support fingers, the said apertures being spaced apart at a distance equal to the spacing of the fingers in order to permit attachment of the strip by engagement of the free end of the fingers in these apertures.

It may be noted that, in all the various methods of attachment which have just been described, the damping strip is disposed above the direction of alignment of the printing types, between the level of the latter and the free end of the fingers. This arrangement, in combination with the characteristic damping properties presented by elastomers, makes it possible to obtain a maximum efficiency in the damping of the vibrations produced in the fingers by the action of the striker members. It has in fact been found in high-speed machines that this results in a distinct improvement in the quality of the printing on the paper.

Although the essential features of the invention have been described in the foregoing and illustrated in the accompanying drawings, it is obvious that the person skilled in the art may make therein any modifications of form or detail which may be considered necessary, without departing from the scope of the invention.

We claim:

1. ln a printing mechanism comprising printing types fastened to an endless flexible metal band stretched around a pair of driving pulleys rotating at constant speed, a plurality of printing hammers adapted to be selectively actuated and disposed along a rectilinear portion of the path followed by the printing types between the two pulleys and in proximity to said types, said hammers being adapted to effect a selective printing of characters on a printing support by producing brief contact of this support with predetermined printing types, said endless flexible metal band being provided on an edge with flexible strips in the form of fingers each having one end integral with the band edge and a free end which extends parallel to the axes of said pulleys and supported for flexure about said band edge in the plane of said band, said fingers being identical and equally spaced apart, each finger being provided, on one face thereof and towards its free end, with one of said printing types in relief, said band also comprising an endless strip consisting of an elastomer and secured to the free end of each of said fingers to permit its flexure and to damp vibrations produced in each finger as a result of the action of one of said hammers on said finger.

2. An endless type support band according to claim 1, wherein said endless strip is secured on that face of the fingers on which the printing types are mounted.

3. An endless type support band according to claim 1, wherein said endless strip is secured on that face of the fingers which is opposite to that on which the printing types are mounted.

4. An endless type support band according to claim 1, wherein said endless strip is formed with apertures in which the free ends of said fingers are engaged.

5. In a printing mechanism wherein a type carrying band is continuously moved relative to a plurality of hammers which are adapted to be selectively actuated to apply a force to a selected type character effective to provide selective printing of characters on a print support; an endless type support band comprising, a flexible band portion movable along a path spaced from the hammers, a plurality of flexible strips in the form of fingers integrally formed at one edge of said band portion extending perpendicular to the path of movement and having one end substantially free for flexural movement about said edge of said band portion, a type element disposed on each of said strips near the free end thereof, and elastomer means other than said band interconnecting each of said flexible strips near the free end for damping vibrations produced in said strips by hammer action during the printing operation.

6. The mechanism of claim 5 wherein said vibration damping means comprises an endless strip interconnecting each of said flexible fingers.

7. The mechanism of claim 6 wherein said endless strip consists essentially of an elastomeric material.

8. The mechanism of claim 5 wherein said flexible fingers consist essentially of metallic material and wherein said endless strip consists essentially of an elastomeric material.

9. A type support band for use in a printing machine wherein the type is impacted to cause printing on a printing support, comprising; a flexible band portion having a plurality of strips each supported at one end by said band for flexural movement about one edge of said band and having the opposite end substantially free, a type element disposed on each of said strips near the free end thereof, and elastomer means other than said band interconnecting each of said strips near the free end for damping vibrations produced in said strips when impacted during the printing operation.

10. The type support band of claim 9 wherein said damping means comprises an endless strip of elastomeric material.

Claims

1. In a printing mechanism comprising printing types fastened to an endless flexible metal band stretched around a pair of driving pulleys rotating at constant speed, a plurality of printing hammers adapted to be selectively actuated and disposed along a rectilinear portion of the path followed by the printing types between the two pulleys and in proximity to said types, said hammers being adapted to effect a selective printing of characters on a printing support by producing brief contact of this support with predetermined printing types, said endless flexible metal band being provided on an edge with flexible strips in the form of fingers each having one end integral with the band edge and a free end which extends parallel to the axes of said pulleys and supported for flexure about said band edge in the plane of said band, said fingers being identical and equally spaced apart, each finger being provided, on one face thereof and towards its free end, with one of said printing types in relief, said band also comprising an endless strip consisting of an elastomer and secured to the free end of each of said fingers to permit its flexure and to damp vibrations produced in each finger as a result of the action of one of said hammers on said finger.