US2225915A - Electric machine - Google Patents

Description

Dec. 24, 1940. LOSER 2,225,915

ELECTRIC MACHI'NE Original Filed Dec. 19, 1932 3 Sheets-Sheet l ,JeR EEN/N 6 5 AMPL lF/ER CUTTING A MP1. lF/ER /90 George E Lander Dec. 24, 1940. LOSER 2,225,915

ELECTRIC MACHINE Original Filed Dec. 19, 1932 3 Sheets-Sheet 5 Q I 0 IV/-45.

JiwJ/ 23/ 234 232 235 233 236 ee/' .E. L oJL'er.

W A b lzas Patented Dec. 24, 1940 UNITED STATES PATENT OFFICE ELECTRIC MACHINE George E. Losier, Bloomfield, N. J., assignor of one-fifth to William A. Hughes, Newark, N. J., and four-fifths to Marion L. Losier, Bloom- 4 Claims.

The present invention relates to methods and apparatus for cutting printing plates and for cutting plates which can be used for making matrices for cast type metal and for cutting other reproductions of pictures, images, patterns and so on.

The present application is a division of my copending application Serial No. 647,884, filed December 19, 1932, and issued to Patent No. 2,092,765, on Sept. 14, 1937.

An object of the present invention is to provide a cutting head for use in an electrically controlled halftone picture reproducing machine.

Other objects of the present invention will appear from the following description and accompanying drawings used to describe and show illustrative embodiments of the present invention.

The accompanying drawings, forming part of the present application, show, somewhat diagrammatically, an embodiment of the present invention, with alternative forms of certain parts, in which:

Figure 1 is a plan view, somewhat diagrammatic, or an apparatus embodying the invention;

Figure 2 is a section view in elevation, taken along the line 22 of Figure 1, looking in the direction of the arrows, and in part cut away;

Figure 3 is a vertical section of a scanning head;

Figure 4 is a diagram of the circuit of an amplifier used;

Figure 5 is a vertical elevation view in section of the plate cutting head, in place on a plate to be out, taken along the line.5-5 of Figure 6, looking in the direction of the arrows;

Figure 6 is a section view, in part cut away, taken along the line 66 of Figure 5, looking in the direction of the arrows;

Figure 7 is a bottom plan view of a portion of Figure 6, looking from the position of arrows 'l-'l;

Figures 8 and 9 are, respectively, side and back elevation views of the end of the cutting tool;

Figure 10 is a diagrammatic illustration of a screen-effect producing unit of the apparatus, including a screening wheel;

Figure 11 is a graph of current against time, showing relative strengths of current used in reproducing light, grey and dark portions of the l icture;

Figures12 and 13, 14 and 15, and 16 arTl' 17 are sets of section elevation and plan views, respectively, or parts of the cut plate corresponding, respectively, to light, grey and dark portions of the picture, and corresponding, respectively in sets, to the light, grey and dark portions of the plotting of Figure 11; and

Figure 18 is a somewhat diagrammatic view of a screening wheel, in part cut away; and

Figure 19 is a diagrammatic view of a scanning H tape, alternate in form to the wheel of Figure 18.

In the drawings a channel shaped bed l0 (see Figures 1 and 2) carries a pair of spaced apart bottom rails II, II, and a pair of side rails l2, [2, one on each of the channel sides l3, l3, which pairs of rails H, H, and l2, [2, respectively support and laterally guide a picture table l4 and a plate table l5 by means of the bottom rollers l6, l6 and side rollers l1, ll. Means for moving said tables l4 and I5 synchronously on said rails H, l l are provided comprising an arm l8 pivoted at one end to said table l4 and at its other end to a lever H] which at an intermediate point pivots on a pin 20 fixed on a side l3 of said bed I0 at one end thereof. Similarly an arm 2| pivoted to said table l5 connects to a lever 22 which pivots on a pin 23 at the other end of said bed ID. A rigid turnbuckle arm 24 connectslevers l9 and 22 in driving relation by means of slides 25 and 26, which are pivoted on to each end of said turnbuckle arm 24 and which are fixedly adjustable one in each of the slots 21 and 28, in the outer,

ends of said levers l9 and 22, respectively. By arranging the distance of said slide 25 from its corresponding pin 20 to be different from the distance of said slide 26 from said pin 23,"the length of the stroke movement of said table I4 can be made to be difierentfrom that of said table l5, either greater or less to suit the needs of reduction or enlargement from the picture to the plate, as desired. Obviously, when the reproduction is to unit scale there distances are arranged to be the same.

Movement of said tables [4 and I5 is secured by means of a motor 30 which drives the slow speed vertical shaft 31 which passes through said bed In and drives a scotch yoke 32 (see Figure 2) which connects with the bottom of said table M in driving relation. The scotch yoke, a well known form of adjustable mechanical movement, is used on account of its adjustability to secure different lengths of strokes of movement of said table l4 (and of table l5) to suit various sized pictures to be reproduced. In the present case adjustability of the distance of movement of said table M for each revolution of said shaft 31 is secured through the adjusting screw 33.

Directly over said table [4 is a scanning head 35 for scanning a picture 36 carried by said table l4. Said scanning head 35 rides on the bar 31,

mounted transversely across said bed I0 and with its ends fixed to said sides I3, I3, for movement of said scanning head 35 across said picture 35 while said table I2 is carrying said picture 36 longitudinally, the relative movement of said scanning head 35 with respect to said picture 36 being along a diagonal across said bed Ill, in a manner and by means hereinafter fully described. Said scanning head 35 comprises a support bar 46 which rides on said bar 31 and which carries a housing 4| within which is a photoelectric cell 42 which latter faces downward toward said table It. A tube 43, slidably mounted on said support bar 40, extends vertically below said photoelectric cell 22 with its upper end fitting in sliding relation in a short tube 44 connecting with and ex tending downwardly from said housing 4|. Said tube 43 has fixed thereto a rack 45 which engages with a pinion 46 mounted to said support bar 46 and having a thumb-piece (not shown) vfor moving said tube 43 up or down to adjust the position thereof. In its side adjacent said support bar 46 carries a laterally projecting short tube 41 in which is mounted a condensing lens 48 opposite which, on said support bar 46, is a source of light 49. At the lower end of said tube 43 is a set of condensing lenses 50, and between said lens 48 and lenses 50 is a reflecting prism 5| adapted to reflect light passing thereto from said lens 43 so that it passes through said lenses to to a picture 36 on said table I4 by which it is reflected upwardly back through said lenses through an aperture 52 carried at the upper end of said tube 43 and thence to said photoelectric cell 22.

Means for moving said scanning head 35 on said bar 31 comprise a bevel gear 55, on said shaft 3|, which drives a pinion 56 on a shaft 51'which drives a bevel gear 58 and pinion 53, which latter, through the set of interchangeable reduction gears 60 drives another set of reduction gears (not shown) in gear box 6| from the upper side of which extends the driven slow speed shaft 62 which carries a belt pulley 63 opposite which latter, on a side I3, is an idler pulley 54. Between said pulleys 63 and 64 there extends a belt 66 which connects with said scanning head 35 by a set screw 61 in driving relation. The driving gear train for said belt 66 is geared down to move said belt 66 at such a rate that said scanning head 35 is moved the distance of the size of the screen mesh to be simulated in the case of a one to one reproduction or a predetermined coefiicient thereof in case of reduction or enlargement, for each forward and back stroke of said table I4, that is, for each revolution of said shaft 3 I. Mounted on and insulated from said shaft 3| is a commutator 10 having one part cut away for half the distance around its circumference in which place is set an insulating piece 1|, with brushes 12, 12 bearing on the commutator so that for one half of a revolution of said shaft 3| said commutator 10 makes a circuit between said brushes 12, I2 and for the other half it breaks the circuit. Said brushes 12, 12 connect to the leads 13, 13 one of which includes a source of electric energy M for a purpose hereinafter described.

Over said table I5 is mounted a cutting head in operative relation to a plate 3| on said table I5, in similar relation to that of said scanning head 35 with respect to said picture 36. Said cutting head 86 rides on a bar 82 mounted to said sides I3, I3, across said bed In and receives its motion from a belt 83 mounted on idler pulley 84 and driving pulley 85 which latter connects through a set of interchangeable reduction gears (not shown) in gear box 66, through a connecting shaft 81 and pinion 83 to said bevel gear 58. Through these driving means, said cutting head 80 will move in synchronism with said scanning head 35 when the latter moves, either in unit ratio for exact size reproduction or greater or less if enlargement or reduction is desired; the ratio being changeable through the gears of said gear box 85, or of gear box 6|, or of gears 35 or any or all of them.

Said cutting head 86 (see Figures 5, 6 and 7) comprises a supporting rod 98, one end or which rides in looking engagement in the slot 9| in said bar 82. From the other end of said rod 80 there depends a bar 92 having a vertical slot 93 therein in which latter rides a slide rod 94 whose position in said slot 33 is fixed and vertically adjustable by means of the screw 85 which is threaded into said slide rod 94 at its lower end and has its upper end extending through an opening in said rod 36 where it has a knurled fixed head 96 bear ing against the upper surface and a fixed Washer 91 bearing against the lower surface of said rod 36.

Said slide rod 94 intermediate its ends carries a yoke 98 which extends transversely in the direction away from said bar 32 and which carries Within itself an electrcmagnet 99 having a polepiece Hi6 extending in the direction toward said bar 22. Said electromagnet $9 is energized by said source 16 through said leads 13, 13 in a manner and for the purpose hereinafter described. An armature bar I82, hinged to the lower end or said slide rod through an offset I83, extends vertically upwards and carries at its upper end a transverse bar I64 which extends through an opening I05 in said slide rod 54 and carries an armature I96 in operative relation to said pole piece I00.

Extending oppositely from said bar I36 and fixed to said armature bar I32 is a support bar I01 which supports beneath it a permanent magnet yoke I68, which latter at its outer end carries an electromagnet I69 and at its inner end carries the pole-pieces III], III having therein, respectively, the oppositely facing slots H2, H3. Said field coil I29 is energized by direct current during opertion of the mechanism. Clamped one on each side of said pole pieces I IEI and I I I, by means of the bolts H5 and H6 are the back plate H1 and the front plate II8. Said bolts II5 and H6 also hold between them the oval shaped coil I25 which extends horizontally edgewise through said slots IIZ, II3. Extending centrally lengthwise in the longitudinal opening I26 of said coil I25 is the flat armature I21 which carries, one at each end, the flexible loops I28, I28, each of which is mounted on one of said bolts I I5, |I6 which loops I28, I28 allow a small rotative movement of said armature I21 about an axis which is the median of said coil I25. To be actuated by such rotative movement of said armature I21 is a vertical tool holder I30 which connects at its upper end through a flexible link |3I to said armature I21, said link I3I being flexible in a direction at right angles to said coil I25. At its lower end said tool holder I30 terminates in a chuck I32 which carries a cutting tool I33.

Clamped between a shoulder I34 and an adjustable nut I35 on said tool holder I36 is a flexible annular diaphragm I36 which serves to hold the lower end of said tool holder I30 and to steady it during movement. Said diaphragm I36 is attached by the four screw bolts I31, I31, near its edges, to a bar I33 fixed to the bottom of said yoke I38 under the pole piece end and extending outwardly therefrom with an opening I39 therein through which said tool holder I30 passes.

To one side from saidtool holder I30, said bar I38 carries a vertical guide I45 through which extends a vertical slide bar I46 which has a longitudinal passageway I41 extending therethrough and carries a horizontal bar I48 projecting therefrom under said diaphragm I36 with an opening I49 therein into or through which said toolholder I30 passes. A longitudinal passageway I50 within said bar I48 connects at its inner end with said passageway I48 and at its other end terminates in a U-shaped opening I5I through the lower face of said bar I48 about said opening I49. In the bottom face of said bar I43 adjacent said opening I5I is another opening I52 which connects with said passageway I50 and which carries therein the supporting roller I53 which is adapted to ride on and to carry the cutting head over a plate BI to be cut by said tool I33. Means (not shown) for drawing a suction through said passageways I41 and I50 will draw chips cut from the plate and any dirt from under and through said openings I5I and I52. A brush I54 fixed in said opening I52 and bearing on said roller IE3 will wipe off any chips or dirt adhering to the latter and release them to be carried away by such suction. A gear rack I55 fixed to said slide ba'r I46 engages a pinion I50 in said guideway I45 which latter carries a spindle I51 which passes through a friction bushing I58 in a wall of guideway I45 and terminates in a knurled head I59. By turning said knurled head I59 to move said pinion I55 on said rack I55, said cutting head 80 can be raised or lowered to suit the length of said tool I33 and to suit the length of the cutting stroke thereof.

In Figures 8 and 9 said cutting tool 33 is illustrated in detail in which the shank i555 carries at one end the cutting point H563 which has two cutting edges I61, I61 which taper to a point from said shank IE5 and for making a plate of a given screen the angle A defined by said edges I01; I6! is predetermined the value of said angle A being smaller for fine screens than for larger ones. The bisecting line of said angle A is at right angles to the plate being cut. The face I68 of said cutting point I66 is cut upwardly and back from the perpendicular at an angle B to give the tool a bite, the back of the cutting point is cut backwardly from said two edges IKi'I to give them clearance and in the form here illustrated defines two faces I69, I69. Togive bottom clearance, said cutting point I65 is cut upwardly and back from the tip at an angle C from the horizontal whereby a diamond shaped face Ill) is defined in the embodiment of the tool illustrated in Figures 8 and 9. 9

Referring again to Figures 1 and 2 and others, said photoelectric cell 42 connects to the aporiodic screening amplifier I80 (see Fig. 4) by the leads I 8| and I82, which amplifier um comprises two high amplification tubes I83 and I84, which are connected in series with each other and with said photoelectric cell 42, and two power tubes I85 and I96 which are connected in parallel with each other and in series with said tubes I83 and I84, with a resistor I87 in parallel between said tubes I04 and I85. From the plates of said tubes I85 and I06 a lead I88 connects to one terminal of a screening system IQiJ-andfrom the grids thereof through said resistor I31 and a source of electric energy I9I the lead I92 connects to another terminal of said screening system I90.

The rest of the connections of said power amplifier I80 are conventional, as shown.

Said leads I88 and I92 connect and carry power to a reflecting galvanometer I93 of the type commonly known in the art as the vibrator element of an oscillograph. The mirror I94 of said galvanometer I93 is in operative relation to a con- I stant source of light I95 and an optical system comprising three condensing lenses I96, I96 and a light slit I91, which latter is arranged to permit a vertical beam of light to be projected by said lenses I96, I96 onto said mirror I94. In operative relation to receive reflected light from said mirror I94 is a second photoelectric cell I98, with a horizontal cylindrical lens I99 between for concentrating the reflected vertical beam from said source I95 into a point at a toothed light interrupting disc 200 positioned between said cylindrical lens I99 and said photoelectric cell I98 and mounted on a shaft 20I (see also Figure 1) which latter is driven by said cutting table I5 through a stud 2&2, fixed to the latter and connected to a chain 203 (which can be a rack and pinion or other equivalent) through a sprocket 204 and a gear train 205. An alternate to said disc 200 is a toothed ribbon 206 (see Figure 19) which can be driven in back and forth movement by said table I5 and which can be a notched opaque strip or a transparent strip 206 having an opaque portion till running lengthwise thereof with one edge describing serrations or a series of uniform notches which come to points at their tops and bottoms like a saw edge.

Said light interrupting disc 200 (also ribbon 206) is opaque and is positioned in relation to said galvanometer mirror Hi4 so that the light reflected by the latter passes midway between the top and bottom of the notches of the disc 200 as at G in Figures 18 and 19 (at which point the Width of the teeth and of the notches is the same) when said photoelectric cell 42 is passing over a portion of a picture which is midway in tone between black and white.

From said photoelectric cell I98 leads 2H! and 2 connect with the cutting amplifier 2I2 which can be a transformer, resistance or impedance coupled amplifier of types generally well known and its purpose is to amplify the current passed through said photoelectric cell I08 to sufficient strength to operate said cutting head 80. Leads 2!? and 2M connect said cutting amplifier to said coil I25 (see Figures 5 and 6) When a pushpull type amplifier is used the lead 2I5 connects from the source of high potential of the amplifier to the midpoint of said coil I25.

In the operation of the above described embodiment of my invention for making a printing plate from a picture or other delineament, a picture 36 is placed on said table I4 laterally within the movement range of said scanning head 35. The said picture 96 can be aligned with the direction of movement of said table I4 or transverse thereto, but preferably for black and white printing it is placed at an angle of about fortyfive degrees so that the black (or white) printed dots in adjacent rows are alternate or staggered (see Figures 13, 15 and 17 which show sections of the printing plate) whereby adjacent dots of a given shade, black or white, are adjacent only at the corners thereof thereby avoiding continuousbands of black or white or more or less continuous width in the longitudinal direction which produces an optical illusion which detracts from the desired effect in the picture. The manner of cutting is more fully explained hereinafter.

When a positive plate BI is to be made from a positive picture 36, or a negative printing plate 8| is'to be made from a negative picture 39, then said scanning head 35 and said cutting head are moved in opposite directions across said bed 59; and, if a negative printing plate 8| is to be made from a positive picture 36, or a positive plate 8| is to be made from a negative picture 35, then said scanning head 35 and said cutting head 89 are moved in the same direction across said bed Ill.

Said picture 36 and plate 8I being properly placed and fixed on their respective tables I4 and I5 by suitable means not shown, said scanning head 35 is brought to lower end of said bar 3? as shown in Figure 1 and the table I4 is moved to the right in Figure 1 far enough for the left hand corner of said picture 36 to be to the right beyond the line of travel of said scanning head 35. If said picture 36 is a positive and a negative plate is to be out then said cutting head 89 is moved to the upper end of said bar 82 in Figure l and said table I5 is far enough to the right to bring the left hand corner of said plate ill to the right of the line of travel of said cutting head 80.

The various electric circuits and sources of light are now energized and said motor 30 is set in motion, whereupon said tables I4 and I5 begin their synchronous rapid forward and backward movements and said scanning head 35 and cutting head 80 commence their comparatively slow movement across the picture 36 and plate 8I, respectively. During forward movement of said table I said commutator I0 is in the open circuit part of its rotation and said electro-magnet '99 is de-energized leaving said cutting head 89 down in the plate cutting position, and during the backward movement of table I4 the circuit between said source of electric energy I4 and said electro-magnet 99 is closed through said commutator Ill and said cutting head 89 is lifted out of the plate cutting position. This movement of said cutting head '80, by said electromagnet 99, into and out of plate cutting position is through movement of said armature bar I92 on its hinged connection at the lower end of said slide rod 94.

Light from said source of light 49 is reflected from a point on said picture 36 to said photoelectric cell 42, the amount of lightreaching the latter being proportional to the degree of light or shade at the point of reflection. Likewise the value of the current which flows through said photoelectric cell 42 and the circuit connected thereto, including said screening amplifier I80 and oscillograph unit I93 is proportional to the amount of light reaching said photoelectric cell 42.

said galvanometer I93 is now energized by current passing through said photoelectric cell 42 by virtue of light reflected to the latter from said picture 36 on said table I4 and said mirror I94 is deflected at an angle from a predetermined normal energized position in one direction or the other in ratio to the degree of light or shade of the picture above or below the predetermined medium or normal tone. Said angle is zero, of course, when the said photoelectric cell 42 is scanning those parts of the picture 36 which are of medium or normal shade. Said light interrupting disc 299 is now rotating and entirely cutting oiT successive portions of the light passing from said mirror I94 toward said photoelectric cell I98 whereby the current flowing through the latter and through said coil I25 of said cutting head 80 and the circuit therebetween varies in alternate succession from a minimum in accordance to the dark conductivity of said photoelectric cell I98 when the light is cut 01f therefrom, to a maximum which occurs when light from said mirror passes through the notches of said disc 200. The graph in Figure 11 indicates the changes in value from minimum to maximum of this current as the light is interrupted by said disc 200, and also the time duration of the minimum and maximum current values as determined by the position of said mirror I94 and the path of the light from the latter to said photoelectric cell I98. It is seen that for light portions of the picture the time duration of the maximum value of the current in the graph of Figure 11 is greatest and of the minimum value the least. For the dark portions the maximum value of the current is of the least duration and the minimum of the greatest duration. For the grey portions the time duration of the maximum and minimum current values are substantially equal.

During periods of the greatest time duration of the maximum current value said cutting tool I33 will reach its greatest depth in said plate 8| because it will have time to reach further, for although it is actuated into and out of cutting position from several hundred times to several thousand per second, said table I5 and plate 8i is moved at a corresponding speed to give the required number of actuations of said cutting tool I 33 per inch of movement of said table I5 and plate BI, for example, to simulate a sixtyfive mesh screen, the number of complete up and down movements of said cutting tool I33 per inch movement of plate 8| will also be sixty-five. The number of actuations of said cutting tool i33 in a given unit of time depends on the number of interruptions of light made by said disc 299, and, of course, on the mechanical characteristics of the moving parts, for example, of said cutting head 89. An actual working example is in cutting pictures in a babbit metal plate at the rate of ten lineal inches per second to simulate a sixtyfive mesh screen under which conditions the actuations of said cutting tool I33 are thirteen hundred per second, regard being had for the fact that half of the one second period is used the forward or cutting movement and half in the return movement of said cutting head over said plate 8|.

Figures 12, 14 and 16, respectively, show enlarged cross-sections of parts of said plate SI having cut therein, respectively, the depressions 23I, 232 and 233 by said tool I33, the depths of these said depressions being proportional to and the areas of the horizontal or printing faces of the elevations 234, 235 and 236 between said depressions 23I, 232 and 233, respectively, being directly proportional to the time durations of the maximum value of current at those parts of the current curve in Figure 11 marked, respectively, light, grey and dark. Face views (also enlarged) of the plate parts shown in Figures 12, 14 and 16 are shown, respectively, in Figures 13, 15 and 17, with the printing faces of the elevations 234, 235 and 236 blackened in with ink to indicate the relative degree of shading and light on those parts of an image or picture printed from a plate 81 having elevations 234, 235 and 236 thereon of various areas of horizontal or printing surface. The slanting arrows indicate the direction of movement of the cutting tool I33 in going over the plate 8| during the cutting operation. Where the depressions in the plate 8I run in together as Figures 12, 13 and 14, 15 the elevations (234, 235) are in the forms of frustums offour-sided prisms, with the top faces of the frustums forming the ink receiving areas. The depressions 23l, 232, and 233 have their lower portions (if not all) in inverted four-sided hollow pyramidal contour. Figures 14 and 15, for example, illustrate a section of printing plate of the invention in which the area cut away was equal to the printing area (made up of the faces of elevations 235, 235) which is left. Here the depressions 232, 232 are in the form of inverted four-sided pyramids. In Figures 12 and 13 the depressions 23I, 23I are in the form of inverted four-sided pyramids which run in together at their bases, the cut-away surface area being greater than the printing area left. In Figures 16 and 1'7, the form illustrated has the printing area greater than the cut-away surface area. Here again the depressions 233, 233 are in the form of inverted four-sided pyramids. In some cases the lateral faces of said depressions 23l, 232 and 233 are not true planes but can be slightly concave, due to the shape of the energy curve of the current supplied to said coil I25 and the resultant movement of said tool I33 with respect to said plate 8| as the two are moved, the former up and down and the latter horizontally.

The operation of said cutting head 80 to give an average light and shape effect, for example, to compare with that of the picture being reproduced, in several ways as for example, by adjusting the light slit 52 in the scanning head 55; by raising or lowering the cutting head 80 as by thumb adjustment I59 to adjust the depth of cut; by adjusting the median of the angle of movement of the beam of light from the galvanometer mirror I94 with respect to said interrupter 250; by running the whole apparatus faster or slower whereby the depth of cut is shallower or deeper; or by using harder or softer metal for the plate to be cut to control the depth of cut in various other ways.

Themethod and apparatus of the present invention, in addition'to use in a unit machine, are applicable to use in an arrangement in which the cutting head is at a point distant from the scanning transmission of current from one to the other being accomplished by wire connection or by a radio system, with suitable amplifying units when required and with suitable means for synchronizing the scanning head and the cutting head. In such case a number of cutting heads could be set up in operated relation to one scanning head and several reproductions made simultaneously. In such case positives and negatives could be made at the same time on different cutting heads governed by the same scanning head.

Having thus described my invention, what I claim and desire to protect by Letters Patent, is:

1. In a photo-electric engraving machine, a

cutting head comprising a cutting tool, a controlling diaphragm for said cutting tool, an actuating armature for said cutting tool, and an actuating coil for said actuating armature; and electromagnetic means separate from said actuating coil for moving said cutting tool in a direction away from its cutting stroke.

2. In combination, a cutting head comprising a cutting tool, electrical means for actuating said cutting tool, and a controlling diaphragm for said cutting tool; and electromagnetic means, separate from said electrical means, for moving said cutting tool in a direction away from its cutting stroke.

3. In a cutting head, in combination, supporting means, a V-shape pointed cutting tool adapted for movement with respect to said supporting means substantially in a straight line along the axis of its point, electrical means for actuating said cutting tool including an electromagnet having a movable core mechanically connected to said cutting tool, and. a controlling diaphragm for said cutting tool fixed at two places on said supporting means in a plane substantially at right angles to said straight line and fixed to said cutting tool at a point intermediate said two places.

4. In an engraving machine in which a V-faced cutting tool is moved reciprocally in rectilinear motion along the axis of its V-face and a surface of a part to be cut is moved in operative relation to said cutting tool and in a direction substantially at right angles toward and from the V-face of said cutting tool and at right angles to the direction of said rectilinear motion of said cutting tool, said rectilinear motion of said V-faced cutting tool being in the directions toward and from said surface of said part to be cut, a cutting head for operating said tool comprising, in combination, supporting means, a tool holder for a V-faced cutting tool adapted for movement reciprocally with respect to said supporting means substantially in a straight line along the axis of the point of a V-faced tool held thereby, electrical means carried by and having a fixed position on said supporting means and being adapted to operate said tool holder reciprocally in said straight line and being adapted to move the point of a V-faced tool in said tool holder into and below the surface of a part to be cut and out of and from contact with said surface of said part to be out, said electrical means including an electromagnet having a movable core mechanically connected to said tool, and a controlling diaphragm for said tool holder fixed at two places on said supporting means in a plane substantially at right angles to said straight line and fixed to said tool holder at a place intermediate said two places.

GEORGE E. LOSIER.

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