US2405786A - Printing machine - Google Patents

Description

Aug, 13, 1946. w. T. GOLLWITZER PRINTING MACHINE Original Filed May 31, 1953 3 Sheets-Sheet 1 Weldon" Um T Aug. 13, 1946. w. T. GOLLWI'II'ZER PRINTING NACHINE Original Filed May 31, 1938 s Sheets-Sheet 3 III I I I I 'IH LCKPPPP W Patented Aug. 13, 1946 ZAGSJSG PRINTING MACEHNE Walter '1. Gollwitzer, Euclid, Ohio, assignor to Addressograph-Multigraph Corporation, Cleveland, ()hio, a corporationof Delaware Original application May 31, 1938, Serial No.

210,897, now Patent No. 2,265,229, dated Decemher 9, 19,41. Divided and this application May 31, 1943, Serial No. 489,112

4 Claims. 1

application is a division of my copending application, Serial No. 416,547, filed October 25, 1941, which was, in turn, a division of my then copending application, Serial .No. 210,897, filed May 1 and new issuedas United :States Letters Patent No. 2,265,229., patented December '9, 194.1. The aforesaid application Serial No. 415154? is directed to the plate clamping means shown herein, while Patent No. 2,265,229 is dirooted to the combination of a perforating mechanism and the embossing means herein shown.

The present invention relates to preparing printing devices and the like, and particularly to embossing machines for forming type characters on printing devices as on plates or like elements of such devices.

In such embossin machines, the printing plates which are to be embossed are supported in the desired relation to an embossing position while embossing dies are actuated to form the desired type character on the printing plate, and to attain the required distribution of the successively for-med characters upon the printing plate, the printing plate is shifted through character spacing, back spacing or like spacing movements with relation to the embossing position of the machine. Such spacing movements are attained through the use of a s'hiftable carriage means upon which the printing plate is supported, and to improve and simplify such carriage means .and its operation through such required shifting or spacing movements is the primary object of this invention.

Further and more specific objects of the (invention are to enable the carriage means in such an embossing machine to be indexed or spaced in either direction longitudinally of a line of type coordinate the line spacing and carriage return vmeansso as to simplify the operation of the embossing machine; and to afford a common actuating means for-effecting line spacing and carriage return movements.

Other and further objects of the present invention will be apparent from the following description and claims and will be understood by reference .to the accompanying drawings which, by way of illustration, show .a preferred embodiment and the principle thereof and what I now consider to be the best .mode in which I have .contemplated applying that principle. Other embodiments of the invention embodying the same or equivalent principle may be used and structinal changes may be made as desired by those skilled in the :art without departing from the present invention and the purview of the appended claims.

"In the drawings:

l is .a fragmentary front eleva-tional view of an embossing machine embodying the present invention;

Fig. 2 is an .elevational view of a printing plate of the character produced by a machine as illustrated inFig. 1;

Fig. 3 is an elevational view of a printing and control device in which such a printing plate may be used;

Fig. 4 is a fragmentary plan view .of the carriage illustrated in Fig. 1., with the gripping jaw-s removed therefrom;

Fig. .5 is .a horizontal sectional view taken in the direction of the arrows on the line 5-.-.5 on

Fig. 6 is a fragmentary detail view of a ratchet employed in the arrangement illustrated in detail in Fig. 5.;

Fig. .7 is a sectional detail view takensubstantiallyon the line 1-1 on Fig. 5.6;

.Fig. :8 is a front elevational view of the carriage arrangement;

.Fig. 9 is a view partly in elevation and partly in section .of .a portion of the carriage arrangement shown in Fig. 8; and

Fig. 10 is :a sectional view taken substantially on the line J ll-4 9 .on Fig. 9..

An embossing machine embodying the present invention is illustrated generally in Fig. .1, While a printing plate of the character such a machineiis adapted to produce is shown in ,Fig. .2. This printing plate, designated 242., is pnov-ided printing characters which-are formed there- -on by the embossing machine, such printing characters appearin in relief on one race of the plate 632 and in intaglio on the opposite face .of this plate. These characters may be arranged in individual lines as shown in Fig. 2, for example, to enable printing of the various lines of a name..55 and address -56 and supplemental data as 51.

Printing plates such as 42, ,Fig. 2, are adapted to be mounted onprinting and control devices as as shown in Fig. 3. As commonly constructed such printing and control devices as 40 comprise a frame 44 having along its lower edge a head 43 against which the lower edge of the printing plate 32 is fitted. Retaining devices-M struck from the frame 4| are disposed in spaced relation to the head 43 and cooperate therewith to retain the printing plate I42 on the lower half .of the frame 4|, .the devices .44 engaging the upper or serpentine edge of the plate 32. To restrain the .plate 45 may be depressed to enable th plate 42 to be slid endwise from the frame.

A bead 50 is formed along the upper edge of the frame 4| and cooperates with retaining devices struck from the frame 4| to removably secure separate index and control cards 52 and 53 in position on the upper half of the frame. The index card 52 has an impression thereon of the data represented by the printing characters constituting the name 55 and address 56 embossed on the printing plate 42, thereby affording a convenient visible indication of such data. The control card 53 and the underlying portion of the frame '4! are adapted to be perforated as shown in Fig. 3 to represent, according to a predetermined code, for example, supplemental data such as the numerical amount printed from the characters 51.

It will be understood, that while I have described the printing plate 42, Fig. 2, as being incorporated in a printing and control device as 48, Fig. 3, this i merely illustrative of the manner in which such a printing plate may be utilized for, as is well understood by those skilled in the art, printing plates such as 42 may be equally Well employed in printing devices which are not equipped with control areas such as 53, Fig. 3.

In fact, insofar as the present invention is concerned, the use to which a printing plate such as 42 may be put is immaterial and has been described hereinabove only as a matter of general interest.

- The embossing machine is so arranged that the die heads 65'and 66, Fig. 1, may be rotated on a vertical axis to bring any selected pair of complemental dies 65:: and 66a, Fig. 1, into operative relation with a blank plate 42 carried along the forward side of the machine frame by a carriage 15. The die heads 65 and 66, as herein shown, are fixed in vertically spaced relation on a rotatable vertical shaft 16, Fig. 1, journaled at its lower end in th machine frame 68 and at its upper end in an upstanding arch-like frame element H. The pairs of complemental dies 65a and 6612 are mounted in opposed vertically shiftable relation about the periphery of the die heads 65 and 86 so that any pair, selected and shifted by rotation of the die heads to an embossing position at the forward side of the machine, may be brought together to emboss the selected character on the plate 42 positioned between the selected pair of dies.

Actuation of the selected pair of dies 65a and 66ais preferably effected by means which drive the two dies toward each other so as to engage the plate 42 and form the desired character therein without vertically shifting the plate from the full-line position of Fig. 10. In the form illustrated this means, for the upper die 65a, comprises an upper rocker arm 18, Fig. 1, pivoted at 19 on the frame element 1'! and operated by a toggle 89, interposed between said arm I8 and an actuating shaft 8| mounted adjacent to the top of the frame element 11.

The lower die 66a is actuated by a lower rocker arm 85 which has one end pivoted at 85' to the frame 'I'Lwhile a pitman 86 operated by a crank 81 on a horizontal operating shaft 88 is connect- 4 ed to its other end. A lower die stock 89, Fig. 7, is mounted for sliding movement in the frame between the lower rocker arm 85, Fig. 4, and the lower die 86a located in embossing position. A similar upper die stock 9|, Fig, 1, is provided between the upper rocker arm 18 and the upper die 65a, the die stock 9| being supported for vertical 1 movement on a carrier arm 92 pivoted at 19.

When the shaft 88 is rotating, the two rocker arms 18 and are constantly actuated in unison by the pitman 86 and an operating connection'between said shaft 88 and the toggle shaft 8|, such operating connection being located at the back of the machine and being shown in detail in the patent to Joseph S. Duncan and Henry E. Hubbard, No. 1,831,103.

As described in the patent to Joseph S. Duncan, No. 1,518,904, the rocking movement of the arms 18 and 85 is normally ineffective to actuate the dies 65a and 65a. To this end shiftable die shuttles 9m and 92a, Fig. 1, are mounted for movement into the path of the arms 18 and 85 only when an embossing operation is desired. The shuttles 9m and 92a are connected by links to opposite ends of a lever 93, which is rocked by means of a bell crank lever 94. This bell crank lever 94 is associated with the die selecting mechanism in the manner disclosed in said Patent No. 1,518,904 50 as to render said rocker arms 18 and 85 operable only after selection and proper positioning of a pair of dies.

The selection of the desired pair of dies 65a and 99a is, in the present embodiment, effected by the keys 81a and 81!), Fig. 1, the die-carrying shaft 18 being normally rotated at a high rate of speed and being stopped in any selected position by suitable stop or abutment means operated by said keys. The mechanism for effecting such selective positioning of the die heads forms no part of the present invention, and therefore it will sufiice to point out that its specific structure is described in the aforementioned Duncan et al. Patent, No. 1,831,103. It may be stated, however, that as disclosed in said patent, the dieactuating rocker arms 18 and 85 ar rendered effective automatically during one rocking cycle of these arms immediately after and as an incident to the stopping of the die heads in any selected position.

The carriage 15, Fig. 1, upon which the plate 42 is supported during the performance of the embossing operations, is so constructed and related to the die-actuating mechanism as to effect automatic step-by-step or character spacing movement, as Well as providing for tabulating and back spacing movement and manually effected line spacing of the plate 42. To this end the carriage 15 has its main body portion mounted by means of a plurality of guide rollers 95, Figs. 8 and 10, on a transverse rail or track 96 which extends across the front of the frame 11. The rollers 95 are so related to the track 96 as to permit movement of the carriage across the front of the machine during, for example, character spacing movement of the carriage, while on the top of the carriage a cross slide 98, Figs. 8 and 10, is provided for movement transversely with respect to the track 96, or toward and away from the die heads. Thus, the cross slide 98 provides for line spacing movement, the plate 42 being supported on the cross slide 98 by releasable clamping means such as the clamping jaws 99, Fig. 10.

As shown in Figs. 8 and 10, the jaws 99 are carried on a mounting member I88 which is detachably secured to the cross-slide 98 by means described hereinafter, the member I80 having upstanding bearing lugs Ifl'l thereon in which a jaw-supporting shaft N32 is j'ournaled. The two jaws '99 and 95", Fig. '10, are in the nature of opposed plates, the lower one 99' of which carries lugs H13, Fig. 8, through which the shaft 482 rotatably extends, and the upper jaw 99" has a pivotal connection with the iower jaw 99 .by means of pins NM extending loosely through the two plates 99 and 99". These pins I04 have securing wires 135 extending 'therethrough on the outer sides of the two plates, 99 and 99" and the pins -4 .and these plates are so fitted as to permit slight pivotal movement for clamping and unclamping of a "printing plate 42.

To provide for clamping of the jaws 99, the plates '99 and 99 extend at their rear ends so as to embrace opposite sides of the shaft M12, and the shaftis flattened on opposite sides there- *of as shown in Fig. 1-0. Thus when the shaft 12 is rotated in one direction nearly 90 relative to the plates 99" and 9 9" and into. a position like that shown in Fig. 10., the adjacent rear edges-of the plates are separated so as to clamp the for-- ward or outer edges of the plates or jaws upon the printing plate i2. It will be seen in Fig. 1-0 that a substantially U-shaped spring Hit is provided adjacent the central pin Hi4 and between the plates as and 93 to separate said plates or ijaws to the maximum extent. Preferably the forward end of the upper jaw 89 is hooked cooperates in 'pincers fashion with a fiat portion or ledge on the forward end of the lower jaw $9 to firmly clam the printing plate M in position, as shown in Fig. 10. To facilitate accurate positioning of the printing plates between the jaws, a shoulder till is formed on the lower jaw 95 slightly inwardly of the flat part thereof, thereby affording a stop for limiting insertion of :a print ing plate as 4-2 between the jaws.

In the operation of the jaws 99 to clamp a printing plate t2, the jaws are first rocked toward the operator so as to rest against a loading abutment 1| \I'Ei formed on the member i023. Such movemerit of the jaws is effected by the shaft #62 which has a 90 rotative lost motion connection with the lower jaw 99', sufficient to enable the shaft I82 to accomplish its jaw-clamping function in addition to its function in moving the aws between loading and working positions. The desired .lost motion is attained by means that are shown and described in my aforesaid Patent No. 2,265,229. To facilitate the operation of the jaws 39, the shaft 1.62 has a knurled operating diskor .lzn'ob H l on its projecting left end, Fig. 8. When the jaws $9 have been shifted to their upright or loading position the shaft 102 is turned to the full extent permitted by its lost-motion connection so as to thereby present the flattened surfaces thereon to the jaws 99 and 99 and thereby enable the spring let to separate the plate clamping portions of the jaws so as to fully release or unclamp the jaws. I he printing plate G2 is then inserted between the jaws 89 which grip the plate sufii'ciently firmly to enable the jaws to be rotated back to their horizontal position shown in Fig. 10 without releasing the plate, 'soas'to thereby enable the plate to be carried to its working position. This movement of the jaws 'is limited by an abutment pin H 2 Fig. 10, on the cros slide 98, and to securely clamp the printing plate, the "operator continues the turning of the shaft 302 to the full extent permitted by its lost motion connection which results in retracting T the flattened portions of the shaft I'M from the jaws 9-8 and so" :so as to dispose these portions in the position shown in Fig. 10 and since the rounded portions on the shaft then engage the jaws they are forced into tight engagement with the plate. It will be understood that such rocking movement of the jaws 99 to and from the loading position takes place in the normal use of the machine while the carriage 15 is located at one side of the embossing position.

As herein shown the mounting member Ill-0,, Figs. 8 and 10, is secured on the cross slide 98 by means which provides for adjustment of the mounting member parallel to the path of the carriage, and also which provides for adjustment of the mounting member .so that the plate 52 carried thereby is positioned with its axis parallel to said path of the carriage '15.. To this end the top face of the cross slide. 93 has aligned slots H3 and H3, Fig. 4, formed therein generally parallel to the carriage path, and a 'iixed depending jpin H4, Figs. 4 and 8, projects from the mounting member Hi0 into the slot H3. For cooperation with the other slot H3 a pin H4 is provided which is fixed eccentrically on a small "disk H5 mounted in the bottom of the member me. By means of a stub shaft 41:5 Figs. '4 and 3 projecting upwardly through the member Hill, the eccentric :pin lid may be shifted so as to adjust the mounting member into the desired parallel relation to the carriage path, and by a lock .nut H5, Fig. :8, threaded onto the stub shaft i it, this adjustment may be maintained.

A headed screwiflii', Fig. 10, extends through an aperture ifliWin the member HM! and is threaded into the cross slide 98 to :secure "the mounting member Hi0 onto the cross slide 98 and, as shown in Fig. 10., the aperture 190" is :somewhat larger than the screw Hill so as to permit the desired horizontal adjustment of the member Iiifl.

To afford longitudinal adjustment of the mounting member 160, a transverse slot 93', Fig. 4, is formed :in the cross slide 58 and a headed screwed, projecting from the left end of the member i103, Fig. '8, has the lower edge of its a head positioned in the slot '98. Thus, by adjustment of -the screw 98" the positioning of the mounting member longitudinally of the direction of movement of the carriage is determined.

For the purpose of imparting the desired line spacing movement to the printing plates, the cross slide '93 is normally urged to a retracted position by springs 15', Fig. 10, and is advanced line by line by means of a ratchet mechanism H6, Figs. 4 and 5.. In the form shown, the cross slide 8 is partially (supported and guided on the car riage 1'5 by a rod ll, Figs. 9 and 10, which is secured to the carriage "l5 and is slidab-ly fitted in bearing apertures H8 in depending flanges H9 along the front and rear edges of the cross slide 98..

A rotatable shaft i212, Figs. 5 and 10, is mounted transversely of the carriage '55, and pinion 125 fixed on this shaft mesh with racks :22 formed on dependingflanges at opposite ends of the cross slide 98. The shaft 126 carries a ratchet wheel I25, Fig. 5, at one end thereof, and this ratchet is fixed in a rotatively adjustable relation to the shaft I20 through the medium of a non-rotatable collar I26 and two adjusting screw i 21', as shown in Figs. 6 and '7 of the drawings. An actuating pawl I30, Figs. 4, 5 and 8, and a control pawl TM are associated with the ratchet wheel 12%: to actua-te the shaft 428. As shown in Fig. 5, the actuating pawl I30 is of an inverted U-form and is pivoted intermediate its ends, at I 32, on one end of a carrier arm I33. The pawl I30 has a tooth I34 at one end thereof and this tooth is urged into operative engagement with the teeth of the ratchet wheel I25 by a spring I35 extended between the pawl I30 and its carrier arm I33. The carrier arm I33 is pivotally mounted on the shaft I20 for rotative movement relative to said shaft, so that by rocking said arm from the position of Fig. in a counterclockwise direction the cross slide 33 may be advanced. The carrier arm I33 is normally urged by a spring I34 to its normal position as shown in Fig. 5.

A bell crank I35, Fig. 4, pivoted on the carriage has an actuating arm I35 which engages the downwardly extending end of the carrier arm I33, as shown in Fig. 5, and this bell crank I35 is operated by a second bell crank I35 which is pivoted on the ame axis as bell crank I35. One arm of the bell crank I 36 extends outwardly from the carriage I5 and constitutes a line space lever I33, Fig. 4, while the other arm has a return spring I 3'! connected thereto and has a "stop shoulder I31 formed thereon which cooperates with an abutment I40 on the carriage 15 to determine the initial position of the line space lever I36. Anoperating connection between the line space lever I36 and the transmitting bell crank I35 is provided by a downturned lug I38 on the bell crank lever I36 which overlies the bell crank I35 so that actuation of the lever I36 serves to impart operating movement to the arm I 35' of bell crank I 35 for thereby actuating the pawl I313.

The extent of movement of the lever I33 is limited by abutment faces I40, Fig. 4, on the pawls I35 and I36 which engage the abutment I40 on the carriage I5 so that a full stroke of said lever advances the cross slide 98 one line-space. Having been given such a line spacing movement the cross slide is retained in its advanced position by the controlpawl I3I, Fig. 5, which is pivoted on the carriage beneath the shaft I on a pivot pin I 4| and has a tooth I42 operable to engage the ratchet wheel I25. The tooth I42 and the teeth of the ratchet wheel are so related that the yielding force of the springs I5, Fig. 10, tending to produce return movement of the ratchet wheel I acts to hold the cooperating teeth in their operative relation and thereby fixes the cross slide 98 in the desired position. As shown in Figs. 4 and 5, the control pawl I3I has a finger piece I44 by which it may be depressed to disengage the pawl I3I from the ratchet wheel I25, and the pawl I3I also has a tail piece I45 whioh,in the disengaging movement of pawl I3I, engages a roller I46 on the pawl I to shift said pawl I30 out of engagement with the ratchet I25 to thereby release the cross slide 98 to the restoring action of the springs I5, Fig. 10. A spring I41 acting between the tail piece I and the carriage I5 tends to maintain the control pawl I3I in operative engagement with the ratchet wheel I 25. V

The requisite step-by-step character-spacing movement of the carriage I5 is effected by means provided to control a pring-biased tendency of the carriage I5 to shift toward the right, as viewed in Fig. 1. Such a spring bias may be imparted to the carriage by a conventional tensioning drum TD, Fig. 1, mounted on the extending right end of the rail 96 and operatively connected to the carriage I5 by a flexible band I50 as shown in Fig. 8.

The means herein provided for controlling the spring-biased right-hand movement of the carriage I5 is preferably such as to simplify and cooperate in part in attaining a tabulating control of the carriage as well as affording a back spacing movement and such means include a rack I51 operatively associated with the carriage, a ratchet and pawl mechanism, and a tabulating disc, and a control shaft I'I0, as fully described in my aforesaid Patent No. 2,265,229.

Character spacing is effected automatically near the end of each embossing operation by suitable means such as that shown and described in Patent No. 1,831,103, patented November 10, 1931.

In order that the operator may manually shift the carriage I5 back and forth, as for the loading and unloading operations, mean is provided whereby the carriage may be released from the controlling action of the character spacing escapement. This means preferably includes a manually operable release means located on the carriage I5, and as shown herein, comprises a bell crank lever 220 mounted on a shaft 22I, Figs. 9 and 10, within the carriage I5 and having one arm 222 thereof projecting forwardly through an opening 223 in the forward side of the carriage. The arm 222 constitutes a carriage release lever and is positioned directly over a fixed gripping piece 224 so that an operator may conveniently depress the release lever 222. A spring 225 urges the release lever 222 to an elevated position and as shown in Fig. 10, means is provided in association with the rearwardly projecting arm 226 of the bell crank 22!] to release the pawl I62 from I the ratchet wheel I60 when the release lever 222 is depressed.

Thi last-mentioned means is preferably operable in any position of the rack I51 and the carriage I15, and as herein shown comprises a horizontally positioned angle bar 230, Figs. 8, 9 and 10, mounted on the rail for transverse or vertical shifting movement by the arm 226, and arranged, when elevated from its position of Fig. 10, to release the escapement pawl I62 and thereby permit free traversing movement of the carriage. To this end the angle bar 230 has a forwardly facing channel portion 23I at its left end. Fig. 8, into which a roller 232, Fig. 10, on the rear face of the pawl I 62 projects, and the bar 230 is uspended on parallel links 233 from the rail 96. Thus the bar 230 is maintained in a horizontal position at all times and it is of such a length that the carriage I5 may be shifted a substantial distance to the right, as viewed in Figs. 1 and 8, while still maintaining the roller 234 on the arm 226 beneath the forwardly projecting flange of the bar 230. Hence, when the carriage is located at any point within this range, the release lever 222 may be depressed and the carriage traversed freely back and forth, and upon return of the lever 222 to it normal position the escapement pawl I62 again becomes effective to hold the carriage in its new position.

As shown in Fig. 8, the rack I5! is releasably connected to the carriage I5 by means of the latch member I58 carried by the rack I51, which latch has a notch 240 that is normally maintained in engagement with a lug 24! on the carriage 15 by means of a leaf spring 242 acting upon the latch I58. In some instances it is desirable to move the carriage 75 to the right beyond the range of movement of the rack I51 for the purpose of smoothing the embossed letters by means of a plate roller attachment (not shown). When such rolling of the plate 42 is desired, the carriage I5 is moved to the right, Fig. 8, untila beveled surface 243 on the latch member I58 strikes a pin 244 on the rail 96, so that the latch I58 is disengaged from the tooth MI. The rack I51 then remains in substantially the position of Fig. 8 while the carriage I is shifted farther to the right. In the return movement of the carriage the tooth 2M engages the left side of the notch 24!] so as to shift the rack I51 to the left, Fig. 8, and to cause re-engagement of the latch I58 with the tooth 24!.

It will be apparent from the foregoing description that I have provided an arrangement which materially expedites and simplifies the production of printing plates or the like in embossing machines of the character set forth hereinabove. More specifically, the return of the carriage to its initial position causes the cross slide to be line spaced thereby to speed and facilitate the production of embossed plates by the machine.

While I have illustrated and described a selected embodiment of my invention, it is to be understood that this is capable of variation and modification and I therefore do not wish to be limited to the precise details set forth but desire to avail myself of such changes and alterations as fall within the purview of the following claims.

I claim:

1. In a machine of the character described wherein a work supporting cross slide is mounted on a carriage for line spacing movement, spring means urging said cross slide to a predetermined position and opposing line spacing movement thereof to other line spacing positions, a rack on said cross slide disposed parallel to the path of such line spacing movement, a pinion rotatably mounted on said carriage and meshed with said rack, a ratchet wheel fixed to said pinion for rotation therewith, a control pawl normally engaged with said ratchet to restrain said cross slide against movement by said spring means, an advancing pawl normally engaged with said ratchet and mountedfor movement from an initial position to an advanced position to impart a line spacing movement to said cross slide, spring means urging said advancing pawl to said initial position thereof, a line spacing lever shiftably mounted on said carriage and operable when shifted to actuate said advancing pawl to said advanced position, and means for concurrently releasing both of said pawls from said ratchet wheel to enable return of said cross slide to said initial position thereof.

2. In a machine of the character described wherein a work supporting cross slide is mounted on a carriage for line spacing movement, spring means urging said cross slide to a predetermined position and opposing line spacing movement thereof to other line spacing positions, a rack on said cross slide disposed parallel to the path of such line spacing movement, a control shaft mounted in said carriage parallel to the path of movement of said carriage and having a pinion mounted on one end thereof and meshed with said rack, a ratchet wheel fixed on the other end of said shaft, a control pawl disposed adlacent to said other end of said shaft and normally engaged with said ratchet to restrain said cross slide against movement by said spring means, an advancing pawl normally engaged with said ratchet and mounted for movement from an initial position to an advanced position to impart a line spacing movement to said cross slide, spring means urging said advancing pawl to said initial position thereof, a line spacing lever extending from and shiftably mounted on said carriage and operable when shifted to actuate said advancing pawl to said advanced position, and means for concurrently releasing both of said pawls from said ratchet wheel to enable return of said cross slide to said initial position thereof.

3. In a machine of the character described wherein a work supporting cross slide is mounted on a carriage for line spacing movement, spring means urging said cross slide to a predetermined position and opposing line spacing movement thereof to other line spacing positions, a rack on said cross slide disposed parallel to the path of such line spacing movement, a pinion rotatably mounted on said carriage and meshed with said rack, a ratchet wheel fixed to said pinion for rotation therewith, a control pawl normally engaged with said ratchet to restrain said cross slide against movement by said spring means, an advancing pawl normally engaged with said ratchet and mounted for movement from an initial position to an advanced position to impart a line spacing movement to said cross slide, spring means urging said advancing pawl to said initial position thereof, a line spacing lever mounted on said carriage for shifting movement through an active stroke generally parallel to the path of said carriage and in an active direction opposite to said advancing movements of said carriage, means operable by said line spacing lever in its active stroke to actuate said advancing pawl to thereby impart line spacing movement to said cross slide, means limiting the active stroke of said lever whereby continued actuation of said lever in said active direction imparts return movement to said carriage to said initial position thereof, and means for concurrently releasing said advancing pawl and said control pawl to enable said cross slide to return to said predetermined position.

4. In a machine of the character described wherein a work supporting cross slide is mounted on a carriage for line spacing movement, a rack formed on said cross slide and a pinion on said carriage for advancing said cross slide, spring means acting to retract said cross slide, means for advancing said cross slide or releasing the same for retraction comprising a ratchet wheel fixed to rotate with said pinion, a control pawl normally urged into engagement with said ratchet wheel to prevent retraction of the cross slide and releasable therefrom to permit retraction, an advancing pawl normally urged to engage said ratchet, means for shifting said advancing pawl from an initial position to advance said carriage, means to return said advancing pawl to said initial position, and means operated by said control pawl in its releasing movement to release said advancing pawl from said ratchet wheel.

WALTER 'I. GOLLWITZER.

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