BE475154A - - Google Patents

Description

       

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  "Improvements to machines, to printing".
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  - ,,, 1 The present invention relates to P31ir pressing mechanisms desfines to printing machines such as ceqlfls, quflcflasiveoe% t,% qur, pflq-, putting the pressing mechanism to draw one or more prints from each of said organs. These can take on many different shapes, but in general each organ has a number of lines of printing characters, for example in relief, with the help of which prints can be made on a surface. sheet of paper, envelope, form, etc., The printing unit may comprise a frame or plate holder in which is detachably mounted a metal printing plate capable of being stamped,

     letterpress characters being stamped on this plate to appear in relief on the face of the work. In a variant, the typographical characters are stamped on a so-called one-piece printing unit. In addition, typefaces are sometimes made from stencil paper mounted in a frame of cardboard or other material.
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  When printing must be carried out with the printing units comprising stamped characters, each of these units may,
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 bzz 3 Tt, tiCl'S which the 7 = '¯1 (: C lm) r:' l11Cur .: are li., ':: L'.ltS.

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 after being brought to the printing station, be placed on a printing base, or anvil, with its printing characters facing an ink ribbon, but placed at a slight distance from this ribbon, while the sheet on which the printing is to be made is located above the opposite side of the ink ribbon. A pressure roller provided with an elastic surface can then be driven in a rolling motion on the reverse side of the sheet so as to press the latter and the ink ribbon towards the printing member and to produce an impression on the sheet. .

   The pressure roller rolls transversely across the character lines of the printing member to successively draw prints from said lines.



   Printing units of this kind are often established for their use in the preparation of documents, business documents or other materials and, for this reason, such units usually bear, in addition to characters representing, for example, a name and an address, characters or lines of printing characters which are intended for special purposes and which, therefore, are not used to prepare certain kinds of documents, etc.

   When it is desired to make prints of some of the lines of print characters, to the exclusion of certain other lines, the selection of the lines of characters to be printed is carried out by cutting off certain portions of the elastic insert. of the pressure roller and suitably adjusting the angular position of said roller so that its elastic lining only comes into contact with that of the character lines which are to be used for printing.



   To adjust the angular position and the rolling movement of the pressure roller, gears are often used. These positively determine the initial position of the actual liner relative to the character lines and maintain the desired rolling relationship of the presser roller relative to said lines as the printing operation continues. . Thus, when the pressure roll has been initially brought to a position such that it is ready to roll in

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 through the first line of characters and the other lines of characters in succession) said roll, is placed in a predetermined initial angular position.

   Then, when said roller performs its rolling movement, the elastic lining normally comes to the position of printing cooperation with the character lines of the member. printer, and this, successively from the first to the last line, or final line, of characters, after which said roller receives a movement which moves it away from the position in which it can come into contact with the sheet.



   If the user wishes to avoid printing the first character line, the lining of the pressure roller is formed so that there is no printer cooperation between him and the first character line, so that the pressure roller rotates without coming into contact with the sheet, until it reaches the interval between the first and second lines of characters. The elastic lining then comes to the position of printer cooperation with the sheet and with the, second line of characters of the printer body. Of course, the liner can be changed so that printing two or more lines or parts of lines of letterpress characters is avoided in the initial portion of the print stroke of the roll.

   Such a modification can be regarded as the adjustment of the amputation or "initial cutting" of lines of the machine, since the effect is, so to speak, to amputate the trim by the machine. cutting of certain lines or portions of lines of letterpress characters to prevent printing using said lines or portions of lines in the initial part of the printing movement of the pressure roller.



   If it is to avoid the printing of one or more of the final lines of characters of the printing member, the elastic lining of the pressure roller may be similarly formed or cut so as to prevent printing. cooperation between this trim and the or the final lines of characters. Such modification of the final part of the printing operation can be considered as the setting of the "final cut".

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 or "terminal" of the lines.

   This final cut can, up to a point, be determined by the setting of the point of removal of the pressure roll, but it is achieved in most cases by a combination of these two actions, with the elastic lining being cut to size. desired shape, and the removal of the presser roll being adjusted in a corresponding manner and such as to take place immediately after the completion of printing of the last selected character line. This is how you get crisp, unblemished prints.



   The adjustment of line cutting in printing machines of this kind is usually carried out with great care and precision, so that crisp and unblocked prints are obtained, but it has been found that in earlier pressing mechanisms d other settings of the pressing mechanism may interfere with the setting of the line trimming; as a result, smeared prints are obtained even though the line trimming was initially set with great care. Such troubles have been experienced in the adjustment of line trimming by adjusting the "start-up" or working level of the pressing mechanism and adjusting the printing pressure which is to be exerted by the pressing roller.



   The pressure setting is very important when the print is to form the name and address and the polite letter in a circular letter. It is then extremely desirable that the intensity of the individual pressure be matched with that of the course of the letter, which has been printed en bloc, so that a personal letter of a beautiful appearance is obtained. Although the preservation of the desired line cutting and the proper matching of the intensity of the printed name and address to the printed body of the letter are both of the utmost importance in the production of personal letters of this letter. As such, the smears resulting from faulty line cutting are the most obvious and most damaging.

   As a result, as has been observed, operators tended to avoid adjusting the printing pressure, since this adjustment often disturbs the printer.

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 adjustment of the line trimming and requires a new adjustment of this trimming to prevent smearing. This is why the goal which we propose to achieve precisely by sending circular letters addressed personally, has often been thwarted by the contrast between the appearance of the name and address and that of the printed body of the letter. letter.



   An important object of the present invention is, therefore, to enable the adjustment and mounting of the press mechanism of a printing machine of the above kind to be easily carried out without disturbing the adjustment of the line cutting. According to the invention, this object is achieved by the application of a pressing mechanism in which a pressing roller is driven by a movement which brings it closer to or away from the plane in which it can print and in which the roller is carried by a carriage driven by a back and forth movement along a path substantially parallel to said plane,

   this mechanism being provided with a device for adjusting the pressure exerted by the roller for printing and with a gear transmission which operates under the influence of the reciprocating motion of the carriage to rotate the roller around its axis and adjust its angular position and which is so arranged that the adjustment of the angular position of the roller is not disturbed by the adjustment of the printing pressure.



   When using printing machines of the kind in which this pressing mechanism has one of its main applications, it is often desirable to perform a series of printing operations in which different line cuts are applied alternately or in different directions. some other order of succession. For example, it may be desirable to print text on letters and to print the address on envelopes intended for those letters.

   In this case, each printing unit then usually carries four lines of characters, the first line comprising the name, the second the street indication, the third the indication of the city or town and the department, for example, and the latter, which is usually placed a little further away than the adjacent line, constituting a polite phrase.

   So when the name and address and the polite phrase

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 must be printed in one letter, the four lines of characters of the printing unit are used, while when the address is printed on the corresponding envelope, the initial line cutting of the presser mechanism is adjusted so that the The printing house's polite line is not used, printing being limited to the three lines which bear the name and address. With the previous presser roller mechanisms, it was necessary to pass the group entire printing units through the printing machine with the initial line cutting of the press mechanism in an adjustment position, in order to print the name,

   the appropriate address and salutation on each letter in the entire group of individually addressed letters. The original line cutting was then changed and the entire group of printing units passed through the machine a second time, so as to print the corresponding names and addresses on the letter-related envelopes. These two groups, that is, the individually addressed letters and their envelopes, then had to be sorted to put each letter in the corresponding envelope.



   Another object of the invention is therefore to enable at least two series of documents or papers having a relation between them and involving different settings of line trimming to be printed in a single series of printing operations. the machine. The series of printing units must then be passed through the machine only once. This is achieved by providing the pressure roller with the desired number of pressure pads, each of which has a special line cut, and arranging the different pads so that they are selectively put into action by an automatic mechanism.



  However, preferably, this automatic change of line cutting is made to be disabled when the same line cutting is desired in successive printing operations. Further, the mechanism is advantageously such that the line cutting adjustment can easily be changed so that the number of prints made while the line cutting adjustment device is

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 occupies any particular position among its various automatic adjustment positions can be changed easily.



   Another example of a case where successive prints are taken from different portions or, rows, of a printing unit is that of the printing of lists, with multiple columns by printing machines of the kind envisaged. For example, the name carried by a printing organ may be printed in one column, while the address or other related indication carried by the organ may be printed in another column, as in the preparation of formulas. or tax, accounting or similar bulletins. In such work, each printing member and the corresponding sheet occupy a position relative to each other during a first printing operation, and a second position during the second printing operation.

   The necessary choice of the lines of characters to be printed in such successive printing operations has hitherto been carried out with the aid of screens intended to cover the unwanted lines, or even with the aid of Pressing members with several movable stamping sections or seals, the different sections of these members being selectively actuated in accordance with the position of the sheet with respect to the printing member. In a machine according to the present invention, the choice of the indications to be printed can be made only by the pressure roller mechanism.



   As stated above, the pressure rollers are usually lined with an elastic material which, in the printing process, comes into contact with the paper on which the printing is to be performed. , and the character of the print varies considerably with the elasticity or hardness of the coating material or backing used on the roll.

   In order to obtain the best possible presentation in printing, it is often necessary to adapt the hardness of the roller to the character of the paper used and, with the ink roller, it has often been found that the operators of these machines often avoid changing the roll which is necessary to adapt the characteristics of the lining of the roll to other factors, when the series of operations

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 to perform is relatively short. The fact that the operator neglected to replace the roller with one having the correct lining was mainly due to the tedious work involved in the operation of removing and replacing the pressure rollers.

   However, a machine established in accordance with the present invention can be arranged such that the hardness of the roller lining can be adjusted as desired by the operator. This is achieved by attaching different linings to a roll and changing the angular position of the roll to bring one of the selected linings to the working position.



   According to the invention, therefore, a printing machine is provided with a pressing mechanism in which a pressing roller is carried by a carriage which reciprocates in a path substantially parallel to a plane in which the roller performs. printing operations and in which the angular position of the roller is positively controlled throughout the duration of each printing operation, the mechanism being provided with means for adjusting the annular position of the roller to bring into action different areas of its surface in printing operations.

   In fact, it had already been proposed to mount the pressure roller on a reciprocating carriage provided with a mechanism capable of operating in the movement of the carriage in one of the directions to move the pressure roller towards the base on which is placed. The printing member and, in the return movement of the trolley, the pressure roller is held in the printing position as it rolls across the face of the printing member, an ink ribbon and a sheet. being of course interposed between said member and the pressure roller.

   After the rolling motion of the pressure roller across the sheet has effected the printing of the desired number of lines of characters from the printing body on the sheet, the pressure roller is brought out of its way. working position, and it is of course desirable that the point at which removal of said roll commences be adjustable to allow the clean and unblocked printing of different numbers of character lines.

   In previous mechanisms,

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 it has often been necessary to make a relatively complicated adjustment of a series of adjustment devices to vary this point at which the removal of the pressure roller takes place; and another object of the present invention is to simplify this adjustment and to enable the operator to effect the adjustment by operating simple and easily accessible adjustment motors.



   According to the invention, the machine can therefore be provided with a pressing mechanism in which a pressing roller is carried with the aid of a toggle linkage by a carriage which reciprocates along the side. of a path substantially parallel to a plane in which the roller performs printing operations, a play or partially empty movement connection being provided between a member serving to actuate the toggle linkage and a point relative to at which the carriage moves, so that the toggle is straightened to advance the roller to said plane in the forward movement of the carriage and is broken ¯ after the carriage has completed a par- predetermined length of its backward travel,

   after which the roll is returned to the carriage. In this case, by adjusting the linkage to the set insofar as this link influences the bending of the toggle linkage, the point of removal of the pressure roller can be varied.



  It is also advantageous to provide the mechanism with a device which communicates an initial impulse in the folding of the toggle. In this case, the roller suddenly arrives at the plane in which the printing takes place and suddenly moves away from this plane. This decreases the tendency of the roll to smudge the job, especially when using overlapping sheets with carbon interposed.



   In order to better understand the invention and to facilitate its practice, some constructions in accordance with the said invention will now be described by way of example, with reference to the appended drawings in which:
Fig. 1 is a front view of a printing machine; , Fig., 2, is a plan view of this machine;
Fig. 3 is a section on the line 3-3 (fig. 2);

   (x) final in the straightening of the knee brace tune imoulsion

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Fig. 4 shows on a larger scale part of Figure 3;
Fig. 5 is a section through line 5-5 (Fig. 2);
Fig. 6 is a perspective view of part of the machine;
Fig. 7 is a section taken on line 7-7 of FIG. 2;
Fig. 8 is another view, partially cut away, of part of the machine;
Fig. 9 is a plan view of part of the machine;
Fig. 10 is a plan view of a printing member for use in the machine;
Fig. 11, 12 and 13 are diagrams showing the action of the machine;
Fig. 14 and 15 show the kind of work done by the machine;
Fig. 16 is a perspective view of details;
Fig. 17 is a sectional view of other details;
Fig. 18 is another perspective view of the details of Figure 16;

   
Fig. 19 is a section showing further details;
Fig. 20 is a perspective view of a detail;
Fig. 21 is an elevational view looking from line 21-21 of Figure 20;
Fig. 22 is a section taken on line 22-22 of Figure 8 and shows how the pressure roller is mounted and secured in its working position;
Fig. 23 is a section taken on line 23-23 of FIG. 22;
Fig. 24 is a section taken on line 24-24 of Figure 21;
Fig. 25 is a section through line 25-25;
Fig. 26 is a section taken on line 26-26 of Figure 8;
Fig. 27 is a section taken on line 27-27 of Figure 26;
Fig. 28 is a view similar to Figure 26, but shows the parts in the positions they occupy at another point in the work cycle;
Fig. 29 is a section taken on line 29-29 of FIG. 28;

   
Fig. 30 is a section taken on line 30-30 of Figure 28;

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Fig. 31 is a perspective view of a detail; ¯
Fig. 32 is a section taken on line 32-32 of Figure 26;
Fig. 33 is a section through line 33-33 of Figure 30;
Fig. 34 is a section taken on line 34-34 of Figure 7;
Fig. 35 is a section taken on line 35-35 of Figure 8;
Fig. 36 is a section taken on line 36-36 of Figure 35;
Fig. 37 is a section taken at line 37-37 of Figure 26;
Fig. 38 to 43 are diagrams showing a set of parts of the machine in different relative positions;
Fig. 44 is a vertical section through part of a modified construction;
Fig. 45 is a section taken through line 45-45 of Figure 44;

   , Fig. 46 is a section taken along line 46-46 of FIG. 45;
Fig. 47 is a perspective view of a detail of the mechanism of Figures 44 to 46;
Fig. 48 is a section similar to FIG. 44, but showing the opposite side of the mechanism;
Fig. 49 and 50 are diagrams showing a set of parts of the machine of Figures 44 to 48 in different relative positions;
Fig. 51 is a sectional elevation view of part of another construction;
Fig. 52 shows some of the parts of figure 51 at a different point in their working cycle,
Fig. 53 is a section taken on line 53-53 of Figure 51;
Fig. 54 is a section taken on line 54-54 of Figure 51;
Fig. 55 is a section taken on line 55-55 of Figure 54;
Fig. 56 is a view similar to Figure 55, but shows the parts in different positions;

   
Fig. 57 is a section taken on line 57-57 of Figure 53;
Fig. 58 is a section taken on line 58-58 of Figure 53;
Fig. 59 and 60 are diagrams showing an assembly of the machine of Figures 51 to 58 in different relative positions;

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The machine comprises a desk or desk-shaped frame 70 (Figs. 1, 2 and 3) having a table top T on which sheets, such as envelopes, letterheads, invoice forms and sheets. registers, can be arranged to receive impressions from printing units D (fig. 3, 7 and 10) driven in succession through the machine.

   The printing units D are stacked in a store M and are successively withdrawn from the lower part of the stack to be driven step by step below the table top, passing through a series of positions comprising a printing station. After passing through the printing station, the printing units D are placed in a collecting drawer K located below the table top T, as shown in FIGS. 1 and 3. During this movement, the organs - our printers D come to a probing position SE where tabs 71 (fig. 10) are probed in order to determine whether each organ will be used for printing or "jumped" in its passage through. the machine.

   On leaving the sounding station SE, the printing units D arrive at the printing station, in which they are placed above a base A (fig. 7 and 8) and below an ink ribbon. (fig. 6). While a printing unit D is thus situated, a sheet (fig. 6) on which printing is to be carried out is placed, face down, on the table top T, above the ink ribbon R and the printing member D, and printing is obtained by the action of a pressing mechanism P. The latter is mounted on an upper arm 72 carried by a printing frame 73. The frame 73 has the form of a C and the upper arm 72 of the C is connected by a vertical portion 74, integrally with it, to a lower arm 75.

   The vertical portion 74 protrudes through the table top T next to the magazine M, and the lower arm 75 supports the pedestal A (fig. 26 and 28), while the upper arm 72 supports the presser mechanism above the magazine. plinth A. The C-frame 73 is disposed obliquely with respect to the front edge 76 of the table top T and lends itself to receiving large sheets and forms of various types which had hitherto been difficult to handle in the

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 printing machines, of this type. Further, said frame 73 is set up such that the printing-producing forces involved in a printing operation are absorbed entirely within the frame 73 of the printing machine. so that the support of this frame is relatively simple.



  Thus, as can be seen in Figures 3, 4, 26, 28 and 30, with the front end of the lower arm 12, there is formed a print base support 78 which rests on a support bar. 79 going from one to the other of the end walls 80 of the main frame 70. The base A is fixed to the upper part of the support 78 by screws 78 'visible in FIGS. 26. and, 30. The rear part of the printing frame 73 is supported by a bracket 81 (Figs. 2, 4 and 5) which is attached to the vertical part 74 and which rests and is bolted on a rear support bar 82 going from one of the end walls 80 to the other.



   The presser mechanism P comprises a roller PR carried, below a carriage which is supported and guided by the front end of the upper arm 72 of the frame, 11, au. during the reciprocating movement that it performs in, through the printing position, defined by the base A. In general, the carriage C is guided by rollers 89 and 90 rolling along paths 91 provided on a carriage carrier plate 92.

   The plate 92 is mounted in an adjustable manner on the underside of a head 94 constituted by a forging part forming the front end of the upper arm 72, the adjustable mounting being carried out, as will be described later. , by an adjustment handle 95 making it possible to vary the pressure exerted by the pressure roller PR for printing.



   The reciprocating motion of the roller carriage is derived from a continuously rotating main motor shaft 100, this shaft being mounted. in the main frame 70 just in front of the rear support bar 82 and parallel to this bar. An eccentric 101 (fig. 5) mounted loose on the shaft 100, is periodically connected to the latter by a single-turn clutch 102 (fig. 2 and 5). The eccentric 101 actuates a connecting rod 103 via a collar 104, and the other end of the connecting rod 103 is pivotally connected to the end of an arm 105

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 attached to one end of an intermediate shaft 106.

   This shaft 106 is mounted to oscillate in a bush-bearing fixed in the lower arm 75 and passing through this arm. The other end of intermediate amber 106 is located above table top T, near the lower left corner of magazine 31 (Fig. 2), and carries an arm 109 (Fig. 5). A link 110 connects the arm 109 to an arm 111 attached to an upper swing shaft 112 mounted in the upper arm 72 of the frame 73. The upper swing shaft 112 is parallel to the shaft 106, being mounted in a shaft. bush 112 'rigidly fixed in the upper arm 72.

   On the left end (fig. 2) of the upper swing shaft 112 is wedged to an arm 113 which is connected to the pressure roller carriage C in such a way that the oscillating movement of the shaft 112 communicates a movement. back and forth to the carriage C. When such a movement is to take place, the single-turn clutch 102 is released by a release bar 115 actuated by a pedal 116 (fig. 1), so that the clutch 102 rotates eccentric 101 in a single turn. The operating pedal 116 is also arranged to control the mechanism which brings a different printing member D to the printing station each time the pedal 116 is operated. .



   When the upper shaft 112 and its arm 113 oscillate in a work cycle, the roller carriage C first moves forward along the path determined by the support and guide paths 91 of said carriage and , during this forward movement, the pressure roller PR is moved down from its retracted position in Figure 26 to its working or lowered position of Figure 28. This downward movement pressure roller PR is effected through a toggle mechanism 120 described in more detail below, and when the roller carriage C has reached the limit of its forward movement, the pressure roller PR occupies its fully lowered or working position of Figure 28.

   The return movement of the shaft 112 then causes the carriage to move backwards, while the pressor roller PR is held in its lowered, or working position, and forced to move with a pushing action. rolling across

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 lines of characters from a printing unit D placed at the printing station on the base A. The sheet or form is thus pressed against the ink ribbon to produce the desired print.



   The connection between the arm 112 and the carriage C comprises a ¯transversal bar 122 provided at the end of the arm 113. This bar is connected by two links 124 to the roller carriage C. The connection between the links 124 and the transverse bar 122 is such that, during the stroke of the carriage C backwards, backwards, or printing stroke, the carriage is directly actuated, while, during the forward stroke or preparation of said carriage, this is driven by means of a link which can flex to prevent the risk of damage to the operator's hands if these are placed below the pressure roller PR during the movement of said roll down.

   This drive link comprises a curved notch 125 made near the rear end of each link 124 and facing downward. The two notches 125 normally rest in the upper halves of annular guide grooves 126 provided near opposite ends of crossbar 122 (Figs. 4 and 5).

   In fact, the grooves 126 constitute tapered portions of the cross member 122 with which the curved notches 125 are resiliently held in engagement by springs 127. These are torsion springs whose turns surround the cross bar 122, and each two has back arms 128 which are hooked, at 129, on the upper edge of the adjacent rod 124, so as to urge the latter downwards to engage it in the grooves 126.

   When, in the forward movement of the arm 115, the presser mechanism encounters excessive resistance, such as that which would be caused by the presence of an operator's finger below the presser roller. , the transverse bar 122 acts on the front sides of the curved notches 125 and lifts the rear ends of the connecting rods 124 behaving like cams, which has the effect of disengaging said bar 122 from the notches
125.

   The crossbar 122 can then move empty for the remainder of its stroke while the hooks 129 of the springs 128 slide out of its stroke while the hooks 129 of the springs 128 slide along the upper edges of the links 124. One more push

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 of the presser roller PR downwards is thereby prevented. In its return stroke, the bar 122 re-engages the notches 125 so that it is ready for the next operation of the mechanism.



  The desired positive drive of the carriage C backwards is provided by lower projections or tabs 125 'provided on the links 124 just behind the notches 125. These projections 125' are hooked by the bar 122 when the carriage C is positively driven in its backward stroke, or print.



   One of the printing members D is shown in FIG. 10, and it will be noted that this member comprises a sheet metal frame 130 to which a printing plate (or cliché) 131 is fixed by means of an edge. 132 and rolled tabs 122. Plate 131 is held in its desired longitudinal position on frame 130 by flexible locking springs 134. On the same side of frame 130, an identification card 135 is held by overhanging tabs 136, and by a rolled edge 136 'of frame 150. This card bears a print 137 which may have been printed using some or all of the print characters from plate 131.



   The characters are formed on plate 131 in a series of lines which are parallel to the longitudinal edges of the plate and frame and, for convenience of description, these lines will be described with reference to the lower edge of the plate because, in the machine being described, the printing operation takes place from the lower edge to the upper edge of the cliché. Characters in plate 131 can represent many different classes of data or information, these depending to a large extent on the type of business for which the printing machine and printing devices are used.



  Such a class of information may include a person's name, which is ordinarily formed in the top line of characters 140, the street name, which is usually formed in the following line of characters, 141, city names and country, which are usually represented in the following character line 142, and a formula

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 personal courtesy, which is usually formed in the bottom line 143. The latter, in accordance with the normal pattern of business letters, is spaced from line 142 by an additional interval.



   With the arrangement of the typefaces of FIG. 10, the printing unit D can be used to write addresses on envelopes or to prepare other forms in which it is desired to print only the name of the addressee, the name of the street and the, name of the city and the country. As an alternative, it can be used to print both the full name and address and the personal salutation in a correct position relative to a previously printed main part of a letter, such as the letter 144 which appears in part in figure 14.

   The use of the printing unit D to print different parts of the material represented by the typefaces makes it necessary to suppress certain parts of the typefaces during some of the printing operations, the particular example described above. being such that, during the printing of an address on the envelope, it is necessary to prevent the printing of the polite letter.



   The pressure roller PR rolls, in its working, or printing movement, over the sheet S, backwards, so that the lower line, i.e., line 143, of the printing body is the first to be printed and the lines of characters are successively printed toward the top of the printing body, so that line 141 is the last to be printed in a printing operation.



  Thus, the adjustment of the presser mechanism to modify the initial action of the presser roller with regard to the removal of one or more of the lower lines of characters in the printout to be obtained can be regarded as the setting or mounting of the initial line cutting; whereas the adjustment of the presser mechanism to determine its printing action in the last part of the printing operation with regard to the printing of one or more of the upper lines of characters may be regarded as the adjustment or fitting

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 of the final line cutting.

   The way in which the initial line cutting is effected is shown in Figures 11 and 12, which show a printing member D whose character lines are arranged as shown in Figure 10. In Figure 11, the mechanism presser has been adjusted and arranged so that the name and address, as well as the salutation of the. line 143, are printed in one operation. In Fig. 12, the pressure roller PR has been adjusted and arranged so that only the name and address are printed.



  As a result, the roll of Fig. 12 can be used to print an address on an envelope 145, as shown in Fig. 15.



   The arrangement of the press mechanism of Figures 1 to 43 is such that when the press roll occupies its front limit position where it is ready for the backward printing stroke, a particular point on the circumference of the PR roll is located. directly below its axis, and this point is indicated by an X-1 mark in Figures 11 to 13. In the return movement, or backwards, of the carriage C, the pressure roller rolls in the levorotatory direction around its axis. Consequently, the sector of said roller which extends in the dextrorotatory direction from the mark X-1 constitutes a working face of the roller.

   The PR roll has a diameter such that when the number of lines of characters to be printed in a single operation is relatively small, a number of such sectors can be provided on a single press roll.



  In the mechanism of Figures 1 to 43, only one of these sectors has been used, but in certain applications of the mechanism of Figures 1 and 43, several sectors may be provided. In FIG. 11, an X-2 mark has therefore been entered at 1800 from the X-1 mark, this X-2 mark defining the initial edge of a second roll sector.



   As the rolling movement of the pressure roller PR is positively controlled, it is evident that particular areas of the roller surface cooperate, in the working stroke of said roller, with particular areas or lines of the roller. printing unit, and we take advantage of this feature to adjust or mount the

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 initial line splitting, in most cases for the purpose of determining, at least in part, the final line splitting.



   In a printing operation, the pressure roller PR must exert the required force on the back of the sheet S through an elastic agent such as a rubber sheet. Such a sheet is ordinarily applied in the form of a tubular sheath or coating to the periphery of the PR roll and is then cut to form one or more individual linings PF which, by their shape, their extent. and their position, during the rolling movement of the pressure roller PR, determines the line cutting which must be obtained with the particular packing used.

   Thus, as seen in Fig. 11, the elastic sheet or sheath is cut a short distance to the left of the mark X-1 along a surface 146, so that the edge thus formed meets the outer peripheral surface of the sheath along a line 147 the position of which is such that, in the rolling movement, towards the rear of the plate PR from its initial working position of Figures 11 and 28, said line 147 comes into contact with the , back side of sheet S slightly behind the first line of characters to be printed.

   As can be seen in figure 11, when the PF pad is intended to print the character line 143 which constitutes the polite phrase, the edge 147 is placed near the mark, Xl, while, as shown in Fig. 12, when said PR roller must avoid printing this formula, the corresponding edge 147 'is located much further to the left of the X-1 mark. Thus, the linings of Figures 11 and 12 respectively give different conditions for the initial line cutting. The two end edges 148 of the linings of Figure 11 and 12, respectively, occupy similar positions relative to the roll and are located beyond character line 140.



   In FIG. 13 is shown a presser roller PR, the initial line cutting of which is the same as that shown in figure 11, but the lining of which ends in a plane indicated at 148 ',

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 so that the final line cutting is such that printing of the last two lines of characters from the printing unit D cannot take place. It should be noted that the printing unit D of figure 13 is set up a little differently from the printing unit of figures 10 to 12, the difference being due to the fact that typefaces are provided on all possible lines of the cliche.

   Such training may be employed, for example, in work relating to taxation, where the top two lines may represent the name and address of an owner, while the three lines the lower lines, that is, the lines to the right of Figure 13, are a description of the property owned by that person. In preparing for a collection roll using a printing device of this general type, the owner's name and address is usually printed in a column to the left, and the description printed. of the property in a second column to the right.



  The liner of the roll shown in Figure 13 lends itself to the operations involved in printing the second column. It is understood that the other operation, or first printing operation, that is to say printing the name and address of the owner, would be carried out using a roller lining of the same nature as that shown in FIG. 11, the peripheral extent of this lining being such that it cooperates only with the two upper lines of characters.



   The machine is also intended to simultaneously perform auxiliary printing operations, such as, for example, printing a number using a "consecutive" numberer, printing a date, or printing a signature, when the machine is used to prepare documents such as checks. In order to perform such auxiliary printing operations, the pressure roller PR has a length which is somewhat greater than that which would be necessary to perform the primary printing operations using the members D, and over this additional length from the PR roll a lining is formed

  <Desc / Clms Page number 21>

 PFS auxiliary printing obtained, as shown in Figure 7, by appropriate cutting of the elastic sheath of the pressure roller.



  The auxiliary lining PFS cooperates, via the ink ribbon R, with an auxiliary printing device placed below dū, said ribbon to the left of the primary printing position, as seen in the figure. 1. The relationship between the primary printing position and the auxiliary printing device is shown in Figure 6, which shows a screen 150 forming part of the table top T. This screen has a primary opening 151 delimiting the primary printing position above the base A and a secondary opening 152 delimiting the auxiliary printing position.

   The screen 150 includes a detachable front section 150 'which can be removed easily enough to expose the front end of a slider 155 mounted on the support 78 of the printing stand for movement from its normal position (Fig. 4). ) at a point to the right of this position, with a view to receiving an auxiliary printing unit 156. This unit may be a plate on which are stamped typographical characters which represent the date; or else, where appropriate, the said organ may be a signature plate or a consecutive numberer, depending on what is desired. After mounting such an auxiliary printing member on the slider 135, this slider is turned over to bring the printing member below the strip R.

   Section 150 'can then be replaced.



   The PR pressure roller is mounted on a support frame or frame.



  92 established as seen in detail in Figure 31. This frame includes relatively heavy sidebars 160 connected at one end by a relatively heavy end bar 161 and at the other end by a relatively light spacer 162 The paths 91 are established separately from the frame 92 and each of them is constituted by a rectangular plate of elongated shape.

   One of the paths 91, is fixed along the underside of each of the side bars 160, the outer edge of each plate being slightly extended outwardly beyond the edge of the corresponding side bar 160, to come into contact with the

  <Desc / Clms Page number 22>

 flange 90 'formed on the outer edge of the rollers 90, as shown in Figures 30 and 36. Two such rollers 90 carried by the carriage C roll on the undersurface of each path 91. The inner edge of each path 91 protrudes inwards from the corresponding bar 160 to form a bearing surface 91 'facing upwards (fig. 31) on which the corresponding roller of the carriage C. rolls.

   Each roller 89 is in contact with the path 91 between the points at which the two corresponding rollers 90 are in contact with the underside of the path.



   Two studs 166 are screwed into holes 167 made on the upper faces of the side bars 162 of the frame or support frame, such a hole 167 being provided in each of the side bars 160, approximately in the middle of the length of said bars. As shown in Figure 34, each stud 166 rises through a spacer wall 165 of forging 94 and enters a pocket in which a compression spring 168 is mounted. Each stud 166 carries two nuts 169 which are tight to compress the corresponding spring 168.



   The elastic force of the two springs 168 therefore acts, through the studs 166, to urge the support frame upwards, and means are associated with the wall 165 for controlling the upward movement of the support frame. such that said frame can easily be leveled and, after being leveled, be adjusted relatively gradually in a vertical direction. Three leveling screws 170 are therefore provided to determine the extent to which the support frame can be raised by the springs 168. These screws 170 are located at points considerably spaced from each other and can slide. in vertical bores 171 (fig. 26) of the wall 165.

   The lower end of each screw 170 is narrowed and engaged in a recess 172 provided on the top face of the support frame 2. As shown in Figure 31, one of these recesses 172 is made on the top surface. of crossbar 161, then

  <Desc / Clms Page number 23>

 that the others are formed respectively in the side bars 160, towards the front ends of said bars.



   The vertical movement of the leveling screws 170 is governed by nuts 175 mounted at the rate of one nut on each screw 170 immediately below the wall 165. These nuts 175 are established on their periphery as pinions, and the three pinions mesh with a central toothed wheel 176 mounted below the wall 165 on a bolt 177 which passes through said wall such that its upper end 178 serves to mark the position of a cover 179 detachably mounted on the top of the wall 165 to form an ornamental extension of the surface of the arm 72¯ above the top of the forging 94. The end 178 engages a recess 180 provided on the underside of the cover 179.

   It is obvious that it is possible, by rotating the central toothed wheel 176, to rotate all the nuts 175 in synchronism with respect to their screws 170, which allows the height of the support frame 92 to be modified. thus turn the toothed wheel 176, then it is maintained in the position to which it has been brought with the aid of members associated with the operating handle 95. As shown in FIGS. 35 and 36, the handle 95 is provided with a rod or shaft 190 which protrudes through a flange 191 of the forging 94. The rod 190 carries a worm 192 which meshes with that of the pinions 1 which is adjacent to it.

   So that the worm 192 can properly mesh with the teeth 175 'of the nut 175, said teeth are set so that they are slightly helical, and all the other teeth 175' of the other nuts 175, likewise that those of the central toothed wheel 176, have a corresponding shape.



   As shown in Figure 36, the rod 190 has an annular groove 195 located inside the rim 191, and a pusher 196, disposed in the wall 165 and subjected to the action of a spring 197, is engaged. in the groove 195 to maintain the rod 190 in the desired longitudinal position. An adjusting screw and nut device 198 comes into contact with the upper end of the spring! 21 to allow

  <Desc / Clms Page number 24>

 modify the thrust of the pusher 196 engaged in the groove of the rod 190.



  This adjustment device is accessible, as seen in FIG. 9, when the cover 179 has been removed. Of course, the worm 192 is such that when the vertical position of the support frame 92 has been adjusted using the handle 95, the desired position is maintained even if a fairly large force is exerted towards it. the top on the adjusting screws 170 to be transmitted by the gears 175 and 176 to the worm 192. By its frictional contact with the rod 190, the spring plunger 196 increases the irreversible action of the worm. end 192 and provides protection against disturbance of the vertical adjustment of the support frame 192.



   The vertical movement of the support frame 192, described above, is based on the synchronous and phased movement of the screws 170 and, to allow the initial adjustment of each of the screws 170 relative to the associated nut 175, so as to carry out the leveling of the support frame. 22, each of the screws 170 has over a considerable part of its length a non-circular part 210 (fig. 9 and 28) obtained by flats formed on the opposite sides of this screw . A fixing washer 211, having a central opening corresponding to the non-circular portion 210 of the screw, engages each screw 170 so that the screw can move longitudinally through the washer, but cannot rotate. pax compared to it.

   Thus, when the leveling screw 170 is rotated by the action of a screwdriver engaged in a groove 212, the fixing washer 211 rotates with this screw, whereas, due to a. Irreversible ction of the worm 192 and the retaining action of the spring plunger 196, 18, the associated nut 175 cannot rotate. This adjustment of any of the screws 170 changes the level or inclination of the support frame 92. After, by operation of the leveling screws 170, the support frame 92 has been leveled, the adjustment necessary is maintained by fixing the screws 170 in the angular positions in which they were set.

   This result is obtained with the aid of lock washers 214 provided in a number equal to that

  <Desc / Clms Page number 25>

 fixing washers 211, each of which partly covers the edge of a corresponding fixing washer 211. By tightening a central locking screw 215, each locking washer 214 is forced to lock the corresponding fixing washer 211. We do so. Note that although the locked securing washers 211 prevent the corresponding leveling vias 170 from rotating, these screws can move vertically when the screws 175 are operated by the operating handle 95.



   The carriage C, which is mounted as previously said below the support frame 92, has a movement whose locus is adjusted vertically and leveled as a result of the vertical adjustment and leveling of the frame. said built. This carriage is hollow, so as to enclose certain portions of the drive and control mechanism of the pressure roller, and comprises a member having the form of an inverted trough or channel, which has an upper wall 220, front walls. and rear 221 and 222 and end walls 223 and 224. This carriage is clearly visible in Figures 16, 18, 26 and 28.



   The guide rollers 89 and 90 are mounted on the top wall 220 of the carriage C and, as seen in Fig. 16, pairs of watches 225 are formed on the top face of the top wall. 220 to support, with the aid of pivot pins 226, the two front guide rollers 90. Pair of ears 227 support, with the aid of pivot pins 228, the two rollers, of rear guide, 20, these ears extending rearwardly a sufficient distance from the rear wall 221 so that the rear rollers 90¯ are placed a considerable distance from the front rollers¯20.

   The rollers 89 are supported by support studs 251 carried by ears 230 rising from the top wall 220. Each stud 231 is held in place by a nut 252.



  To mount the carriage on the guideways 91, it is raised to the front edge of the support frame 92 which (Figs. 26 and 31) occupies a position such that its spacer 162 is located a good distance away. above the upper surfaces 21 'of the raceways, and the

  <Desc / Clms Page number 26>

   rollers between these paths and the spacer 162. As seen in Figure 16, the drive rods 124 are connected to the rear part of the carriage C by pivot pins 236 mounted in pairs of ears 235 each of which is integral with one of the ears 227.



   As shown in Figures 18,26, 28 and 30, the toggle mechanism 120 is mounted inside the carriage C on a support shaft 240 which rotates in bearings 241 mounted in the end walls 223 and 224. This mechanism comprises two toggle links, one at each end of the presser roller PR, each toggle comprising an upper toggle link 242 and a lower toggle link 243, these two links pivoting together on a common pivot shaft 244.



  The upper toggle links 242 similarly protrude from the support shaft 240 to pivot about its axis. Each of said links 242 has a groove or slot (fig. 18 and 30) in a plane perpendicular to the axis of the shaft 240, and the upper end of each lower toggle link is engaged in the slot 245. of the corresponding upper link to the point where it is pivotally connected to shaft 244.



   The lower ends of the lower toggle links 243 cooperate with guide links 250 and 251, respectively, to support the pressure roller PR. As seen in Figure 19, link 250 is pivotally connected to adjacent link 243 located at the left end of carriage C (Figs. 1, 8,27 and 30) by two mutually concentric bushings. locked 252 and 253, which protrude through an opening or slot 254 in guide rod 250. Bushing 252 is provided with a collar 255 which bears against the right face, or inside, of the guide rod. toggle 243 (fig. 19), while the sleeve 253 carries a collar 256 which bears against the outer face, or on the left, of the guide rod 250.



  The other end of the guide rod 250 is pivotally connected, by a pivot pin 258, to a lug @ extending rearwardly from the rear wall 221 of the carriage C, as shown. sees

  <Desc / Clms Page number 27>

 in FIG. 16. The other guide rod 251 pivots at one end, using a pivot pin 260, on a lug 261 (FIG. 18) which protrudes on the rear wall 221 of the carriage. , near the right end of the said carriage looking at figure 18, but the left end, as seen in figure 7, shows that the pivots 258 and 260 of the two guide rods 250 and 251 respectively, are coaxial.



     Since the rolling action of the pressure roller PR must be precisely adjusted, a gear mechanism is provided to effect this adjustment, and the final element of the gear train is a pinion, 265 (fig. 19) pierced with a central hole through which passes a bushing - 266. At the left end, looking at figure 19, this bushing carries a collar 267 which prevents the pinion 265 from moving to the left. Bushing 266 passes through an opening 268 in the lower end of the toggle link 245 and enters an opening 269 in the outer end of the guide link 251.



  Said bush is held in this position by another bush 270 which protrudes inside the first and is attached thereto: The bush 2 0 is provided with a collar 271 which comes into contact with the first. - this outer, or right, of the guide rod 251.



   When you want to mount a pressure roller PR between the lower ends of the two knee pads, this roller is placed in the axial alignment of the two sleeves 252 and 270 and a support rod 280 is passed through these sleeves and along the axis. of the pressure roller. In this regard, it will be noted that the roller PR is a cylinder containing roller bearings 281 and 282. As seen in Fig. 19, the left roller bearing 281 comprises a bush 283 recessed in the 'left end of roller and carrying track rollers 284.



   The other roller bearing 282 (including roller bearings
286) is somewhat different in shape because, as seen in Figure 24, it comprises a sleeve 285 embedded in the right end of the roller PR and provided, with a semicircular projection 287 which cooperates with a collar similar curve 288 carried by the pinion 265 (fig. 18 and 19). Thus, when mounting a pressure roller PR, this roller

  <Desc / Clms Page number 28>

 The water can only be placed in one angular position relative to the pinion 265 and, in this position, the parts 287 and 288 fit together to form a complete circle.

   As a result, an operator will invariably effect mounting the pressure roll in the correct position for the line cutting action for which the intended roll has been prepared.



   After the mounting rod 280 has been inserted from left to right (fig. 19), passing successively through the bush 252, the bearings, 281 and 282 and the bush 270, said rod is locked by means which are visible in Figures 19, 22 and 25 and which include a spring collar 295 surrounding the end of the sleeve 270. This has a groove 296 in which is placed the retaining spring 295. At a point of its periphery, the groove 296 is hollowed out (Fig. 25) to form a slot 297 through which a flattened portion 298 of the spring 295 can be placed in locking relationship pax with respect to a groove 299 provided on the surface of the rod. mounting 280.

   The right end of the rod 280 tapers, at 300, so that when said rod is pushed to the right, the inclined surface 300 contacts the flattened portion 298 of the retaining spring and widens the latter, which remains widened until the locking groove 299. comes opposite the flattened part 298 of said spring.



  The ends of the retaining spring 295 are normally crossed (fig.



  25) and constitute operating keys 301 which can be grasped between the thumb and forefinger to disengage the retaining spring 295 from the mounting rod when it is desired to remove the latter.



   As shown in Figures 18 and 19, the above-mentioned gears which govern the rotation of the pressure roller PR comprise a pinion 305 mounted on the pivot pin 260 which supports the upper or rear end of the guide rod 251, this pinion being interposed between said link and the support lug 261. Between the two pinions 265 and 305, and in engagement with them, is a pinion mounted on the guide link 251 using a pin.

  <Desc / Clms Page number 29>

 support 307.

   Pinion 505 is driven by a somewhat larger toothed wheel 310 (Figs. 7 and 32) rigidly attached to a second wheel 311 spaced from the first by a bushing 312 which carries assembly pins 313 passing through bores in the bushing. and toothed wheels so that these members turn as a unit. As shown in Figures 7 and 32, this assembly is mounted on the pin 236 which constitutes the pivot connecting one of the drive links 124 to the corresponding lugs 255 of the roller carriage.

   Of course, the pivot pin 236 is supported by its two support ears 235 and, in addition, the end remote from said pin is supported by an arm 315 (fig. 27) which constitutes a rear extension of the wall. far right 224 of carriage C.



   During the back and forth movement of the roller carriage C, the toothed wheel 511 rotates in synchronism with the reciprocating movement of the carriage. This rotation is communicated to said wheel by a rack 520 approximately parallel to the movement of the carriage C and in engagement with the upper edge of the wheel 311 (fig. 26,27, 28, 32 and ¯3 °).



  This rack is prevented from moving longitudinally, so that, when the carriage C performs its reciprocating movement, the wheel 311, which is mounted on it, is forced to roll on the toothing 321 formed at the lower edge of the rack 520 .



   The necessary independence of the print thrust adjustment from the line cutting adjustment is achieved by mounting the rack 520 and the associated gear train in such a way that when the carriage 0 is moved vertically in In view of the print thrust adjustment, the working relationship between the rack, and the wheel 311 is not changed, even though the wheel 511 has been moved vertically.

   This results from the fact that the rear end of the enamel- er 520 pivots about an axis 322 which is placed a considerable distance behind the limit of the rearward meshing between the rack. 320 and the wheel 311, so that as the wheel 311 moves vertically during the adjustment of the print thrust, the

  <Desc / Clms Page number 30>

 rack 320 rises or falls with pinion 311, to the point where it meshes with the latter.

   Of course, the degree of vertical adjustment normally required of the pressing mechanism is relatively small, so that, within the limits of this normal adjustment scale, the mutual relationship of the elements of the rack and of the gear train remains unchanged. , and the line trimming setting is not changed. The axis or pivot 322 is connected to a fixed bracket 323 which is mounted in a triangular housing 324 extending above the bearing tube 112 '(fig. 2 and 6), the method of mounting said bracket being shown. in figure 29.



   A guide plate 325 is mounted between the wheel 311 and the support arm 315. As this plate is fixed while the wheel 311 is rotating, a support disc 326 is interposed between these two parts. On its upper edge, the plate 325 is provided, at 327, with a double bend suitable for constituting a slide for the rack 320 (FIG. 32). Therefore, the slide 327 maintains the rack 320 in a proper position relative to the toothed wheel 311.



   The toggle mechanism 120 which supports the pressure roller PR is normally biased towards the folding position of FIG. 26 and in the movement of the carriage C forwards, this mechanism comes to occupy the upright position of FIG. 28, from so as to bring the pressure roller PR against the sheet S (fig. 11 to 13). As the roller PR descends from the position of Figure 26 to that of Figure 28, the movement of the carriage C forwards causes, through the gears, the rotation of the pressure roller PR, so that, when this roller reaches its lowered and forward position of Figure 28, it occupies the predetermined angular position which is necessary for the desired line cutting.

   In other words, the position of the pressure roller PR is then that described with regard to FIGS. 11 to 13, the reference point X-1 being situated vertically below the axis of said roller.



   During the print run back, or work, of the carriage C backwards, the toggle mechanism 120 is held in

  <Desc / Clms Page number 31>

 the upright position of figure 28, so that, when the roller PR is actuated, by the gears, this roller acts on the sheet S in such a way that its lining PF cooperates with the selected lines of characters of the printing member D. When the last line of characters chosen has been printed, the knee pads are broken and returned to their position in figure 26.



   The force which normally urges the toggle mechanism towards its folded position in Fig. 26 acts, through the shaft 240 to which the upper links 242 of the knee joints are attached. As seen in Figures 18 and 30, the shaft 240 is supported not only by the two end walls 223 and 224 of the carriage C, but also by bearings 340, 341 and 342 which extend downward. from the top wall 220. A torsion coil spring 345 surrounds the shaft 240 with one end attached at 346 to the bearing 342 and the other being attached at 347 to a collar, 8, which. can rotate on shaft 240.

   A torque can thus be transmitted by the spring 345 to the shaft 240 by means of a ratchet toothing 349 formed on the mutually opposite faces of the collar 348 and of a collar 350 pinned at 351 on the shaft 240 The one-way coupling thus formed is so arranged that the torsion spring 345 can rotate the shaft 240 in the levorotatory direction, looking at Fig. 26, to return the toggle mechanism to position. position of figure 26. To allow easy adjustment of the torsional effect of the spring 345, the collar 8 is drilled with a number of radial holes 355 in which an adjusting pin can be engaged for. rotate collar 348 relative to collar 350.

   As seen in Figure 30, this pin is inserted into the anterior hole µµ ±, and its projecting end receives a downward movement, such that the teeth of collar 348 slide opposite those of collar 350.



   As the carriage 0 moves forward from its rear position in Figure 26 and to its forward position in Figure 28, the knee pads are straightened by a retaining force exerted on

  <Desc / Clms Page number 32>

 the central pivot shaft 244 The mechanism serving to communicate this retaining force is also that which serves to communicate the force necessary to break the knee pads and thus make them able to obey the return mechanism comprising the spring 345. The aforesaid mechanism serving to impart the retaining force, comprises a control rod 360 which has a lug or loop embracing the pivot shaft 244 substantially in the middle thereof. The connecting rod 360 is placed between two legs 362 extending downwardly. from the rear wall 221 of the carriage.

   The necessary retaining force is applied to the control rod 360 through the control mechanism of the carriage. As can be seen from Figures 6, 7, 27 and 29, the swivel arm 113 comprises an upper bush 364 and two radial arms 113 'between which there is a gap 113 ". The two arms 113' are interconnected, at their lower end, by a transverse sleeve 375 integral with them and in which is mounted the transverse bar 122. A transverse pin 366 goes from one of the arms 113 'to the other through a longitudinal slot 367 of the connecting rod. command 360.

   Two bushings 368 carried by the transverse pin 366 on either side of the connecting rod 360, act so as to maintain said connecting rod midway between the two arms 113 '. The slot 367 and the transverse pin 366 constitute a play connection, the effect of which is apparent from Figures 38 to 43.



   When the carriage C occupies its recalled or rear position at the end of a printing cycle, the connecting rod 360 occupies, relative to the drive arm 113 and its transverse pin 366, the position shown on the Figure 38, with transverse pin 366 spaced forwardly from the rear end of slot 367.

   When the oscillating shaft 112 and the drive arm 113 move in the levorotatory direction so as to cause the carriage C to move forward from its rear limit position of figure 38, the connecting rod µ60 moves forward at the same speed as the carriage, but, due to the difference in the radial positions of crossbar 122 and cross pin 366 relative to the axis of shaft 112, the pin 366

  <Desc / Clms Page number 33>

 moves forward more slowly than shaft 112. Since, at this time, ball 360 is moving with carriage C and crossbar 122, it is evident that upon completion of part of the travel of the carriage C forward, the rear end of the slot 367 butts against the transverse pin 366.

   This relation is visible in figure 39, and it will be noted that, in this first part of the oscillating movement of the shaft 112, from the position of figure 38 to that of figure 39, the differential relation of the two elements 122 and 366 causes the pin 366 to move the distance y (Fig. 38) along the slot 367 so that said pin contacts the rear end of the slot 367.



   In the continuation of the movement of the oscillating shaft 112 from the position of figure 39 to that of figure 40, this same differential relation existing between the horizontal components of the movement of the two transverse elements 122 and 366 continues, and when As the shaft 112 reaches the position of Fig. 40, the bar 112 has been moved to the right, in a horizontal direction, by a distance somewhat greater than the horizontal movement of the cross pin 366. The difference between the The movements of the two transverse members 122 and 366 are indicated by x in FIG. 40. Consequently, the carriage C travels a greater distance than the control rod 360.

   As a result, the upper and lower ends of the knee pads move at the same speed as the carriage C, while the central pivot shaft 244 of the knee pads is retained by the connecting rod 360 and moves more slowly. The result of this action is to straighten the toggle mechanism 120, as shown in Figure 40.



   As the connecting rod 360 straightens the knee pads, the gears rotate the pressure roller PR in the dextrorotatory direction to an extent which is directly proportional to the movement of the cart C forward. This rotation is approximately completed when the carriage reaches the position of figure 40. We are

  <Desc / Clms Page number 34>

 thus ensuring that, before the toggle mechanism 120 has been fully straightened, the PF liner of the roller, which is to act in the printing operation, has rotated sufficiently to prevent damaging pressure and reverse rotational movement and pressure of the edge 145 on the paper, so as to prevent smearing.



  As a result, when the carriage reaches the point in Fig. 40, only a very small additional movement of the carriage forwards is required, the initial rotation of the pressure roller PR being thus substantially completed. An additional mechanism is therefore provided to complete the straightening of the knee pads.



   This additional mechanism includes an arm 370 pivoting on the pivot pin 236 which connects the front end of the left-hand drive link 124 to the carriage C. As seen in Figure 37, this pivoting arrangement is achieved by using a socket 371 fixed to the pin 236. A nut 372, screwed onto the end of the socket 371, fixes the arm 370. The latter extends forward through a slot 373 made in the rear wall 221 of the carriage. At its front end, the arm 370 has a curved notch 375 facing upwards, which notch receives a pin 376 carried eccentrically (relative to the shaft 230) by an arm 377 forming part of the sleeve 350.



   The arm 370 is urged upwards by a spring 378 connected to a stud 379 projecting from the left ear 230 (fig.



  16). Of course, the bush 350 is attached to the shaft 240 to participate in its oscillation, and the pin 376 is disposed on the shaft 240, so that when the knee pads are about to reach their positions When straightened, pin 376 meets a cam surface 370 'provided at the end of arm 370 (Fig. 39). The resulting cam action causes arm 370 to pivot downward, and when the knee pads have been brought to a position relatively close to their fully upright positions, the stud 376

  <Desc / Clms Page number 35>

 slides away from cam surface 370 'over the edge of notch 375, as shown in Figure 40.

   The spring 378 then acts so that the curved notch 375, behaving like a cam, pushes back the stud 376, causing a rapid continuation of the movement of the toggle mechanism to its position. completely straightened position. In this way, a fairly large movement is imparted to the central pivot shaft 244 of the knee pads during a very, small movement towards the front of the carriage C.



  When the knee pads have been brought to their fully upright positions, a flat surface 380 ', formed on the top end of each of the lower toggle links 243, contacts a flat top surface of the associated slot 254 to prevent the passage of the knee pads beyond neutral. This contact of the surface 380 'with the top of the slot 245 has the effect of keeping the two links of each toggle in exact alignment and cooperates with the guide links 250 and 251 to maintain the axis of the rod. PR roller in the desired position relative to the carriage C during the rearward stroke of the working roller PR.



   Since the function of the arm 370 is to maintain the knee pads in the upright state, the return movement of the drive swing shaft 112 and of the drive arm 113 has the effect of causing the control rod 360 to move. towards the rear relative to the links 124. However, during this relative movement, a stop lug 380 carried by the connecting rod 360, hits a stop 385 (fig. 42), which delays the continuation of the movement of the connecting rod 360 rearward. The stop 385 is a pin going from one of the two arms 113 'to the other of the oscillating member 113.

   The rearward movement of the central pivot shaft 244 of the knee pads is therefore itself retarded, and when the carriage C continues to move rearward the knee pads break, i.e. - say that the movement of said knee pads towards the folded state begins. Of course, spring 378 is strong enough to hold the knee pads.

  <Desc / Clms Page number 36>

 in the upright state by overcoming the normal forces acting on the various elements of the toggle mechanism and on the pressure roller during the printing stroke. However, when the positive driving force is applied to the shaft 244, this force overcomes the locking action of the arm 370 and has the effect of moving the shaft 244 forward relative to the pivots. upper and lower knee pads.

   As a result, stud 376 moves against the anterior curved face of notch 375 of arm 370, and the resulting cam action causes that arm to pivot downward until stud 376 passes through. over the leading edge of notch 375 and over the anterior sloping cam surface 370 '. The upward force exerted by the spring 378 then acts through the cam surface @ '(fig. 43) so as to increase the return action of the torsion spring 345, and the pressure roller PR is therefore quickly recalled to its retracted position in Figures 26 and 38.



   As stated previously, it is often desirable to vary the point at which this withdrawal movement of the pressure roll PR begins, because this roll is often set so as to avoid printing one or more of the lines. of final characters carried by a printing member, as seen in Figure 13 where the final edge 148 'of the PF liner is disposed such that the printing operation is completed after the first three lines number of characters of the printing unit D have been printed.



  In such a case, many operators find it desirable to begin the removal of the pressure roller PR as soon as the printing of the last selected line of characters has been completed.



   Adjustment of the point of withdrawal or removal of the pressure roller PR is achieved by mounting the stopper tab 380 adjustably along the slot 367 of the connecting rod 360. As shown in Figure 16, a rectangular rib 381 protrudes on one of the faces of the stop tab 380 and engages in the slot 36 ?, the stop tab being held in position by a screw 382 which passes through a washer 383 and is screwed into the projection 381.

  <Desc / Clms Page number 37>

 



   Since the movement of the parts is relatively rapid, the rear face of the stopper tab 380 is preferably provided with a spring member 388 secured by a screw 389, and the member 388 constitutes the actual stopper face of the tab 380 , which engages with the stop constituted by the pin 385 or by a sleeve 386 mounted on this pin.



   The mode of action of the stopper tab 380 to begin the withdrawal movement of the pressure roller PR is shown in Figures 42 and 43.



  It will be noted in Figure 42 that, in its rearward stroke, the carriage C has been brought to a point such that the stop tab 380 is in contact with the transverse pin 385, so that, in the continuation the movement of the carriage backwards, the speed of this movement of the carriage under the action of its drive rods 124 exceeds the speed of movement of the transverse pin 385 towards the rear, this which retards the movement of the control rod 360. As a result, the central pivot shaft 244 of the knee pads is actually prevented from moving backwards, so that the carriage and the upper and lower ends associated knee pads move rearward relative to said shaft, which is shown in figure 43,

   where we see that the toggle has been broken and is in a state such that it can be quickly pulled to its retracted position by the spring 345 (fig. 30 and 37) and by the action of the spring cam surface 370 '.



   In the event that the stop tab 380 becomes free in its slot 367, or in the event that the operator neglects to block this tab, the means are provided to cause the withdrawal of the presser roller PR just before the carriage C reaches the end of its stroke. These means comprise a pin 390 projecting laterally on the control rod 360 (fig. 27) and arranged so as to come into contact with a stop constituted by a spring arm 394 in the movement of the rod 360 towards the rear. The   . @ arm 394 and another spring arm 395 are carried by a console

  <Desc / Clms Page number 38>

 angle 391 (fig. 26 and 31), one branch of which is fixed by a screw 392 on the underside of the rear transverse bar 161 of the support frame 92.

   When the pin 390 is brought into contact with the arm 394, the movement of the connecting rod 360 backwards is retarded, and the folding of the knee pads takes place just as the stop tab 380 comes into action. It goes without saying that this action of the spring arm 394 takes place only when the stopper tab 380 is located approximately at the front end of the slot 368.



   The rear spring arm 395 is intended to cooperate with a pin 398 carried by the control rod 360. The pin 398 occupies a position such that, while the pin 376 passes rearwardly over the cam surface 370 ' , pin 398 bends and cocks spring arm 395. Thus, when pin 376 moves away from. cam surface 370 'and enters the notch 375, the spring 395 acts on the connecting rod 360 to move the pivot shaft 244 more quickly backwards.



   In Figures 44-50 there is shown a variation of the invention in which the operator can selectively employ any of a series of presser roller linings PR without replacing the roller. Thus, as shown in Figures 49 and 50, the PR roll has two linings PF and PF-2 on different sectors of the roll. The PF seal corresponds, as regards its shape and its position, to the PF seal of FIG. 12, this seal being intended to ensure an initial cutting which avoids printing using the line 143 of characters. of the printing unit D of FIG. 10.

   The PF lining carried by the pressure roller of figures 49 and 50 is placed, with respect to the index X-1, in the same way as the lining with respect to the index X-1, in the same way as the guard. PF seal of Figure 13, while the other PF-2 seal is set in a predetermined position pax relative to. the other X-2 mark, the position and situation of which have been described with reference to Figures 11 to 13. Of course, the PF-2 trim could be arranged in

  <Desc / Clms Page number 39>

 any desired relationship to the X-2 mark, but, for the purposes of this description, it can be considered to be formed in the same way as the PF liner of Figure 11.



   The choice of linings is made by moving the enamel pin 320 and for this purpose rack teeth 400 are cut along the top edge of the rack 320 near the rear end thereof. Means are provided for moving the rack 320 longitudinally, so as to vary its initial position relative to the gear transmission which rotates the roller, and, in particular, relative to the toothed wheel 311.



   In the construction of Figures 1 to 43, the rear end of the rack 320 pivots on a bracket 323 carried by the side wall 324 'of a housing 324. In the present construction, the console 323 is replaced by a mechanism. which not only serves as a pivot for the rack 320, but also offers the possibility of adjusting said rack, between a series of positions which determine which of the linings of the roller is to be used in a printing operation. Thus, as shown in Fig. 45, housing 324 contains a U-shaped bracket 401 having bearings 402 and 403 for a shaft 404 which protrudes through side wall 324 '.

   A handle 405 is attached to the outer end of the shaft 404 and carries an eccentric locating pin 406 intended to be placed in coincidence with one or the other of two locating openings made in a locating plate. 408 fixed by screws 409 on the outer face of the side wall 324 '. A relatively wide pinion 410 is pinned to the shaft 404 and meshes with the tooth 400 formed on the upper edge of the narrower rack 320.

   A guide plate 411 supports the rack 320 in engagement with the lower edge of the pinion 410. The plate 411 has an opening 412 through which the shaft 404 passes, so that said plate is so supported. pivoting by the shaft 404. At its lower edge, the plate 411 carries two transverse arms 414 which support the rack 320. The lateral position of the latter is

  <Desc / Clms Page number 40>

 ensured by its engagement in a slot 415 made in a wall 416 extending upwardly of the U-shaped part 401.



   The locating pin 406 is biased to engage with one or the other of the openings 407 by a coil spring 418 which surrounds the shaft 404 between the bearing 403 and the plate 411, this spring 418 tending to move. shaft 404 and related parts to the left of figure 45. Therefore, when it is desired to turn pinion 410, handle 405 is pulled to the right of figure 45 to release the pin 406 of the locating opening 407 in which it is engaged. The shaft 404 and the pinion 410 can then be rotated until the pin 406 is aligned with the other locating opening 407. This movement of withdrawal of the handle 405 is limited by the meeting of the plate 411 with a shoulder 420 of the wall 416 (FIG. 45).



   The positions of the registration openings 407 relative to the pinion 410 and to the other elements of the gear train are such that, when the pin 406 is engaged in one of said openings, the PF lining is in the desired position to come into action in the printing operation, while when the pin 406 is engaged in the other registration opening 407, the packing PF-2 comes into action in the printing operation. Thus, as seen in Figure 49, when the pin 406 is engaged in that of the openings 407 which is located at the rear, the rack 320 is returned to its rear limit position.

   In this case the PF-2 gasket is in the working position, as can be seen from the position it occupies in FIG. 49. In FIG. 50, the pin 406 is engaged in that of the two openings of marking which is at the front so that the rack 320 has been brought to its front position, and that the PF lining occupies the working position.



   This relatively easy selection of fillings is used for several applications. For example, when the operator desires to use selectively different cutouts, these can be provided on different linings of the pressure roll.

  <Desc / Clms Page number 41>

 



  Alternatively, when the same blanking is to be used, the different linings may be made from elastic materials with different characteristics, for example one side of the roll may be a little harder than the side. 'other, so that the operator can easily bring one or the other of the two toppings to the working position to obtain a better match between the printed impression and the characteristics of the paper, or a better adaptation other factors, such as the condition of the ribbon.



   Another construction is shown in Figures 51 to 60.



  This construction is particularly useful when consecutive impressions are to be taken from different portions of the characters carried by a printing member, the different impressions being obtained by means of gaskets, capable of entering into action selectively, which have cutouts. of different lines. The selective printing of the different portions of the information carried by a printing unit D in successive printing cycles is carried out automatically, so that the mechanism is particularly useful in a printing operation of two-column lists.

   Such an operation can be carried out in conjunction with a mechanism not forming part of the present invention, in order to move the sheet S in such a way that a first impression, either, carried out by a PF-3 liner, which prints, in a left column of the sheet, for example name and address, using the first two lines of a printing device, such as that in figure 13, and in such a way that a second impression is then carried out with the aid of other lines, such as the three or more lower lines of the printing member, by a PF-4 packing, this second impression taken from the same printing member D being performed in a column right of the sheet S.

   The arrangement of the liners necessary to perform such a two column list printing job is shown in Figures 51, 59 and 60, and it will be noted that the PF-3 liner is located on the part of the liner.

  <Desc / Clms Page number 42>

 the periphery of the pressure roll which is turned in the dextrorotatory direction from, mark X-1, while the packing PF-4 is located on the part of the periphery of the press roll which is turned in the dextrorotatory direction from the mark X-2.



   When, as has been said previously, it is desired to draw several prints from each printing member D, the machine is adjusted so that the drive of said member from the printing station to the collector drawer K is delayed until the desired number of impressions have been taken from said organ.



   The automatic selection of PF-3 and PF-4 packings is achieved by adjusting rack 320 in the same general manner as in the construction of Figures 44 @@ to 50, with a drive shaft 404 'mounted in a U-bracket 401' supported by the housing 324. The shaft 404 'carries a toothed wheel 426 meshing with the toothed rack 400 cut at the upper edge of the rack 320, which is kept in engagement with the toothed wheel by a support plate 411' mounted on tree 404 '. This mode of support allows pivotal movement of rack 320 during print thrust adjustments in much the same way as pivot 322 in the construction of Figures 1 through 43.

   The rack 320 is protected against any lateral movement by a groove 427 of a wall 428 provided in the lower part of the U-shaped bracket 401 '.



   A coil spring 430 surrounds the shaft 404 ', and the inner end of this spring is fixed, at 431, to the shaft 404', while its outer end is secured, at ¯432, to a part of the U-shaped bracket 401 ', as shown in figure 58. The action of spring 430 is such that it tends to rotate shaft 404' in the dextrorotatory direction (fig. 51) to pull rack 320 towards rear, that is to the left when looking at figures 51, 59 and 60.



   In this example, two linings are provided and, consequently, the automatic mechanism is arranged, so as to move the rack 320 alternately in one direction and in the opposite direction between the

  <Desc / Clms Page number 43>

 two positions in which the two packings PF-3 and PF-4, respectively, are ready for work. This mechanism is actuated by the mechanism driving the presser carriage C and connects the pivoting arm 113 to the shaft 404 '.

   The mechanism comprises a toothed sector 440 comprising a socket 441 which pivots on a stud 442 mounted in a vertical wall 435 'forming part of a housing 435 fixed by screws 437 to the housing 324. The toothed sector 440 meshes with a pinion 443 pinned on the projecting end of the shaft 404 ', so that the relative position of the shaft 404' is governed by the toothed sector 440. The latter is controlled by a cam mechanism comprising a cam follower 445 mounted on a stud 446 which protrudes from the sector 440 at a point a considerable distance below the axis of its support stud 442. The cam follower 445 rests on the periphery of a plate. cam 450 rotating around the axis of a head forming a bearing 451 formed on a stud 452 which passes through a boss 453 of the wall 435 '.

   The stud 452 is held in place by a nut 455. Of course, the spring 430 acts, through the intermediary of the shaft 404 'and the pinion 443. so as to urge the sector 440 in the levorotatory direction, while looking at the Figure 51, to elastically hold the roller 445 in contact with the cam 450. The latter has several cam surfaces which are such that, by, rotation. of said cam, the roller 445 can be brought to any of two different positions. One of them (fig. 51 and 59) is such that it allows the spring 430 to disengage the rack 320 to the extent required to allow the PF-4 lining to be brought to the working position.



  The surface provided for this purpose on the cam 450 is indicated at 460. A part of the oame surface which causes the PF-3 lining to be brought into the working position is indicated at 461, this second surface being separated from the axis of the cam 450 by a distance greater than the surface 460. Depending on the number of impressions to be drawn from each of the linings PF-3 and PF-4, the cam 450 is provided with over- cam faoes corresponding to the cam surfaces 460 and 461. In the present example, the linings PF-3 and PF-4 are brought alternately.

  <Desc / Clms Page number 44>

 to work position. Consequently, the. cam 450 is set so that cam surfaces 460 and 461 alternate with each other around the perimeter, and there is a group of three of each of these surfaces.

   Therefore, in each cycle of the roller carriage, the cam 450 must rotate through an angle of 60. For this purpose, a ratchet wheel 465, having six equally spaced teeth 466, is fixed to the cam 450, these two members being mounted on a common hub 467 and assembled by pins 468. When the cam and wheel assembly ratchet was mounted on the head formed bearing 451, it is secured in position with a cover plate 470 held in place by screws 471.



   The cam assembly is actuated, in each working cycle of the carriage C, by a pawl 475 pivoting at one end thereof on the transverse pin 385. The pawl 475 is relatively long and carries, at its front end, a pin 476 disposed. below the lower edge of the cover plate 470 so that it can engage with the teeth 466 of the ratchet wheel 465. The pawl 475 is biased by a torsion spring 478 which acts between said click. quet and the swivel arm 113 to bias the pin 476 towards the ratchet wheel 465.

   In the forward movement of the arm 113, the pin 476 engages the lower of the teeth 466, and the arrangement is such that, in the continuation of the movement of the pivoting arm 113 towards the forward until the end of its forward travel, the ratchet wheel and associated cam 450 rotate 60 around the axis of the support pin 451-452. Thus, if the cam follower 445 is initially in contact with one of the surfaces 460 of the cam 450, the movement of 60 of the ratchet wheel and the cam has the effect of bringing the next cam surface. 461 in contact with the cam follower 445. As a result, the sector 440 pivots in the dextrorotatory direction from the position of Figures 51 and 59 to that of Figure 60, and thus causes a corresponding movement of the rack 520.

   This takes place during the inactivity or preparation run of the roll carrier C.

  <Desc / Clms Page number 45>

 



  As a result, during the working or return stroke of said carriage, the PF-3 liner plays its active role in the printing operation.



   In the next forward movement of the carriage, pawl 475 engages next tooth 466 and again advances cam 450 by 60. The cam follower 445 then leaves the relatively high surface 461 and passes over the next surface 460. This allows the spring 430 to return the sector 440 in the levorotatory direction, so that said sector again comes to the position of the. Figures 51 and 59. This has the effect of moving the rack 320 to enable the PF-4 packing to operate in the printing stroke of the carriage C.



   In order to deactivate the automatic device determining the choice of the linings, a control plate 480 is mounted on the internal face of the cover plate 470 which must be moved to put the pawl 475 out of action. The control plate 480 carries a threaded stud 481 which protrudes through an arcuate slot 482 of the cover plate 470, and a retaining nut 483 is provided on the protruding end of the stud 481. The arcuate slot is concentric with the ratchet wheel 465, and control plate 480 pivot on support pin 451-453.

   During normal operation of the automatic presser selector mechanism, the control plate 480 occupies the position shown in Fig. 55, so that a cutout portion 484 of the plate allows the pawl 475 to be engaged in the position. toothing of the ratchet wheel 466. When it is desired to put the pawl 475 out of action, the control plate is rotated, 480 in the dextrorotatory direction, looking at figure 55, until the position of the Figure 56, in which a surface 485 of the plate engages the pin 476 of the pawl 475 during the movement of the pivot arm 113 forward.

   This has the effect of guiding the pin 476 opposite the lower tooth 466, so that the pawl AU cannot rotate the cam 460.


    

Claims (1)

CLAIMS. 1. A printing machine having a pressing member mechanism in which a pressing roller is arranged to be moved in a direction which brings it closer to and away from the plane in which it can perform a printing operation and in which the roller is. carried by a carriage capable of receiving a reciprocating movement along a path which is substantially parallel to said plane, the mechanism being provided with a device making it possible to adjust the printing thrust exerted by the roller and a gear mechanism which is capable of operating under the influence of the reciprocating movement of the carriage, so as to rotate and adjust the angular position of the roller about its axis, and which is so arranged that the angular position of the roll is not disturbed when adjusting the print thrust to be exerted by the roll. 2. A printing machine according to claim 1, in which the mechanism is provided with means for adjusting the angular position of the roller to make different areas of its surface capable of coming into action in printing operations. 3. A printing machine according to either of claims 1 and 2, in which the position of the roller about its axis is controlled by a gear mechanism comprising a rack which remains fixed while the roller is in motion. carriage performs an alternating movement, and which causes the pressure roller to oscillate around its axis in one of the directions while the carriage is moving in one of the directions and a print is in progress, and in the 'other direction when the carriage moves in the opposite direction to the previous one. 4- A printing machine according to claims 1 and 3, wherein the rack pivots around a point remote from the carriage and performs only a slight angular displacement when adjusting the printing thrust to be exerted by the roller, the latter adjustment being carried out by bringing the carriage closer to or away from said plane. <Desc / Clms Page number 47> 5. A printing machine according to claims 2 and 3, wherein the rack is adjustable longitudinally so that the angular arrangement of the pressure roll relative to the starter is changed and the portion of the surface of the roll which enters. in action during the printing operation is changed in a corresponding way. 6. A printing machine according to claim 5, in which the adjustment of the position of the rack is effected by hand by a pinion in engagement with the rack. 7. A printing machine according to claim 5, in which the adjustment of the rack is effected automatically by a ratchet operation dependent on the reciprocating movement of the carriage. 8. A printing machine according to either of claims 5 and 7, in which the rack is biased in one direction by a spring and is selectively biased in the other direction by a cam. 9. A printing machine according to any one of claims 3 to 8, in which the pressure roller is arranged to oscillate alternately in one direction and in the opposite direction with respect to said printing plane, on a lever. which pivots on the carriage and which carries a gear transmission connecting the rack to the roller. 10. A printing machine according to any of the preceding claims, in which the position of the pressure roll relative to the carriage is determined by a toggle linkage. 11. A printing machine according to claim 10, in which a clearance connection is provided between a drive member for the toggle linkage and a point with respect to which the carriage moves, such that the toggle link is moved. straightens to advance the pressure roller to said plane, in the forward movement of the carriage, and breaks after the carriage has <Desc / Clms Page number 48> completed a predetermined part of its rearward travel, the roller then being returned to the carriage. 12. A printing machine according to claim 1, in which the press roll is carried by a toggle linkage mounted on a carriage slidable in a reciprocating motion, following a path substantially parallel to a. plane in which the roller performs printing operations a clearance connection being provided between a drive member for the toggle linkage and a point with respect to which the carriage moves, so that the toggle lever moves straightens to advance the pressure roller to said plane, in the forward movement of the carriage, and breaks after the carriage has completed a predetermined part of its backward stroke, the roll being then returned to the carriage. 13. A printing machine according to either of claims 11 and 12, in which the position of a stopper determining the degree of play before the toggle linkage breaks is adjustable by. so that the point at which the pressure roller leaves the printing plane is variable. 14. A printing machine according to any one of claims 11 to 13, in which the carriage is moved to and fro by a pivoting arm connected to the carriage and bearing two stops, the carriage of which is 'one contacts the driver to straighten the toggle linkage after a predetermined degree of idle movement, and the other contacts the driver to break the toggle linkage after a predetermined degree of idle movement. 15. A printing machine according to any one of claims 11 to 14, wherein the toggle link is straightened by overcoming the action of a spring which comes out to bend the toggle after it has been broken. 16. A printing machine according to any one of claims 10 to 15, in which the carriage carries a spring device. <Desc / Clms Page number 49> intended to impart a final impulse to the toggle linkage when its straightening occurs and an initial impulse to the linkage after it has been broken so that the pressure roller abruptly arrives at the printing plane and is pulled sharply to the gap of the printing plane. 17. A printing machine according to claim 16, wherein the spring device also serves to lock the toggle linkage in the upright condition. 18. A printing machine according to any one of the preceding claims, in which the carriage is arranged to roll, on a guide path carried by a frame adjustable in a direction going towards and away from it. 'a support, so as to vary the printing thrust. 19. A printing machine according to claim 18, in which the adjustment of the frame relative to the support is effected by means of screws intended to be actuated simultaneously by nuts coupled by gears. 20. A printing machine according to claim 19, wherein the screws are also rotatable relative to each other to adjust the inclination of the frame. 21. A printing machine according to claim 20, in which the frame is placed in position relative to the support by screws acting on the frame while the latter is resiliently biased in the opposite direction.