US2248446A

US2248446A - Optical profile grinding machine

Info

Publication number: US2248446A
Application number: US278397A
Authority: US
Inventors: Wohlfarth Reinhard Max
Original assignee: Seidel & Naumann AG
Current assignee: AG Vorm Seidel & Naumann; Seidel & Naumann AG
Priority date: 1938-06-29
Filing date: 1939-06-10
Publication date: 1941-07-08
Anticipated expiration: 1958-07-08

Description

July 8, 1941. N M, WQHLFARTH 2,248,446

OPTICAL PROFILE GRINDING MACHINE I Filed June 10, 1939 2 Sheets-Sheet 1 H Q 3/4, 23 a E Rez'nhardMaxWohlfafih I 25 26 ByIhZfSAHOIneyQ m It July 8, .1941. R. M. WOHLFARTH OPTICAL PROFILE GRINDING MACHINE 2 Sheets-Sheet 2 Filed June I 10, 1939 I !I{ IIIIIIIIAVIIIII IIIlIIIIIIIlIlIIIIIIl A RezhhardMcLx 4414,44

' By his Afiorney ments are used it can happen that thelines oithe slide orturntable used as a frame is mounted shadow are distorted. Furthermore the exactthe upper part of a microscope and also the up- Y of the picture on the screen mustbe done b'yithe sit-ions so that either the upper part of the ml- Patented July 8, lgdl STATE OPTICAL PRO GRINDING MAC i i Reinhard Max Wohlfarth, Dresden, Germany, as-

signor to Aktiengesellschaft vorm. Seidel 8: Naumarm, Dresden, Germany Application June 10; 1939, Serial No. 278,397 I in Germany June 29, 1938 '6 Claims. (oral-165) The present invention refers to an opticalvpro- This adjustment is of extreme importance befile grinding machine on which form-gauges and cause an enlargement on the screen is obtained form-tools, etc, are ground by causing a grlndonly in the position of the sharpest adjustment. ing-disk to grind the form-gauges or form-tools which enlargement corresponds to the profile line to their actual shapes which shapes are repredrawn in enlargement on the screen. And there sented by the lines of a very much enlarged drawremains Still the lack o Gleam-9 8. due to the ing. a. fusion of the screen. i

Generally we distinguish between two of If the kind of optical profile grinding machine optical profile grinding machines. In the first fitted with microscope as its optical system asthe pattern line is traced piece by piece by means 10 sures absolute exactness of the making of the of a pin; and this motion is transferred by means profile when the grind n s do e fairly .S O y, of a pantograpli to an optical system which serves even if the adjustment of, the microscope is not forwatching the piece to be ground at the grindmade with the greatest exactness, then the grinding point. The axis or the optical system is al i p e s in the d of Optical profile crimiways brought to the exact position above-the 5 m machine fitted with projection apparatuses grinding point and the grinding wheel is guided s optical system procee P p Somewhat so that it grinds to that place or point which is faster, but at the expense of absolute exactness. observed by means of the optical system. Here- The p e invention bring-S forth anblitifial tofore the optical system has been in the form of profile grinding machine in which are incorpo a microscope. lithe tracing of the pattern is rated the advantages of observation by both finds done with great exactness, which can be satis Qf p y while the dlsadvantagesare iactorily accomplished by means of phototechnic avoided, i. e. the rather slow work .under ohse rva methods, this foregoing method guarantees I an I tion by microscope and the less exact work made. absolute exactness in the profiles to be ground O s o by P j o aPP J dependent upon the accuracy of the pantograph In my invention, I am using an optical profile mechanism. The optical enlargement .of the g in machine i which the axis of an Optical microscope does not directly aiiect the exactness syste p ss d along a traces the desired Shape of the operation at the point of grinding. It of the form-gauge or form-tool under the serves only to observe the point of grinding. 1 guidance oi a mechanical device, which is made In the second kind of optical profile grinding to follow a drawn pattern. v machine the outline of the entire iorm-gauge .or In order to accomplish the aboveprocess it is form-tool to be ground is projected on a screen the first object o y invention o P de fi e in shape of a picture. On this screen the profilesaid machine 4 with means to observe the Point lines are drawn inan enlarged scale and the proo grinding y Optical P ojection. .Fo h D jected picture of the form-gauge or form-tool can pose I use an illuminating device Of- 8 7 be compared with the profile-lines drawn in fen-1 t i y f li ht, the rays of which psss throush largement. Here one sees as a shadow onj'the a set of Optica l s p p l t P 9 screen,.even if vanishing at times, thegrinding screen- Q 5" wheel which is operating on the iorm gapgeor A".s'ec 0nd object of my invention is to provide form-tool in a steady vertical up and down; mo- 40 the said machine with. a. new and useful device, tion, and therefore it'is possible to follow up the which allows observation of a give P operating of the grindingwheel on the form-gauge grinding by means. of two kinds, of Optical. 5 or form-tool and to continue the grinding until tems, i. e. observation by microscope or observathe outlines of the picture coincide with the protion by means of optical projection, each kind of file lines drawn on the screen. observation being used independently of the other Since in this second method optical enlargeat the choice of 'the operator. Therefore on a nessof the method depends on how carefully the per set 9f lensesof the apparatus for optical prooperator services the machine; ,The adjustment jectlon. This Iramecan be shifted into two pooperator so that theoutlines of "the picture ap croscope'pr the upper set of the lenses of the pear sharp and clear-at all times. {This adju'st apparatus for the optical projection device (which ment'however dep n s .more orless on the good .'eve1 ;is desired). .can rest over the lower partiotv eyesight of the operator. r 5 the'ontical sv'stem.

Other objects of my invention are explained as they occur in the following description and in the drawings appended.

In the drawings V Fig. 1 shows a front view of an optical profile grinding machine equipped with means for observation by projection,

Fig. 2 shows a view from above of Fig. 1,

Fig.3 shows a section of the optical system in the pantograph mounting and a view of. the projection device,

Fig. 4 shows a section of two upper parts of the optical system mounted on a gangway,

Fig. 5 shows a view from above of the pantograph system and of a turntable with two upper parts of the optical system.

On base Ii there is a structure on which th form-gauge or form-tool is placed. This structure consists of a housing I2 which is fastened to the base and in which is a bevel wheel l3.

This wheel can be turned by means of a second bevel wheel I4, which is fastened to the end of a shaft [5. To the other end of the shaft 1 5 is fastened a hand wheel IS. The bevel wheel I3 is connected with an internally threaded cylinder l1. This cylinder when turned by means of the hand wheel i6 screws a spindle 18 up and down which spindle supports a hollow shaft l9. This shaft moves within the stationary housing 20. On the upper end of the shaft l9 there is a slide .2! which can be moved to the right or left by means of a spindle 2'2 and a crank 23. Across the slide 2| there is another slide 24 with a table 24a. This slide 24 with the table 24a can be moved to and fro by means of a spindle 25 and a crank 26. The form-gauge or form-tool '21, to be ground can be clamped on top of the said table 24a. s i

Facing this structure there is a construction on which the grinding-disk is movably mounted.

This construction consists of the following parts:

On the base i I is a stationary platform 28. On this platform 28 is rotatably mounted a gangway 29ion which moves a slide 30 to and fro. This slide 30 is moved by means of a spindle 30a and crank 30b. Across the slide 3|] there is another slide 3| which slide moves by means of a spindle 3m and a crank 3lb. .Upon this slide 3| there is a housing 32 for the gears. At the rear of this gear box 32 there is adriving. mechanism, for instance an electromotor 32a which drives the grinding disk 33. This grinding disk 33 is mounted on a slide 34 which slide is mounted movably on the front of an arc-like frame 35 and travels up and down by means of a leverdevice (not shown). The gangway 29 and its super-structure, i. e. the gear-box 32' and the arc-like frame 35 and the slides 3Ufand 3| and the grinding-disk 33 can be turned around on the stationary platform 28 by means of a spindle 36.

Projecting from the side of the base ll there is an arm 31 supporting a stand 33. On top of this stand 38 is a drawing board 39 on which a drawing 40 is stretched. This drawing 40 shows the shape 40a of the profile to be ground on a very much enlarged scale.

From the base Ii extends upwards a column device which when moved along the lines of the pattern-drawing, produces a similar motion of the axis of the optical system. This pantograph system consists of a short arm 43 parallel to a long arm 44 and of two parallel connecting

rods

45 and 46. In the free end of the rectangular arm 42 is a hole into which is movably fitted an outer bushing 41. To the top of this outer bushing 4'! is fastened the connecting rod 46. Within the outer bushing 41, but excentrically to its center, there is movably fitted an inner bushing 48 to which is fastened the short arm 43. 'This short arm 43 is connected with the long arm 44 by the connecting rod 45. Excentrically to the center of the inner bushing 48 there is a hole into which is fitted a lower set 49 of an optical system containing the objective lenses. The end of the long arm 44 is provided with a device 50 which traces the contours of the drawing. Over the hole in the bushing 48 is a projection device. This device consists of a frame 5! which carries a set of projection lenses 52, a mirror'53 and a plane or screen 54 upon which to project. It is an advantage to have the projection device provided with an attachment 65 for a magnifying glass.. In order to have no light entering from the outside upon the projection device the latter is covered by a casing 56.

The optical profile grinding machine has two illuminating devices. One of them is within the base II. It consists of a source of illumination 51 and above it a set of lenses 58. These lenses concentrate the rays upon the point of grinding from below and produces a deep shadow on the screen or projection plane 54.

Another illuminating device is attached to the lower side of the rectangular arm 42. It consists of one or more sources ofillumination 59 which throw their rays upon the upper side of the formtool or form-gauge. The collected rays of this device are .of such intensity that they reflect towards the optical system and then produce a projection of the form-gauge or form-tool at the screen or plane.

The machine functions as follows:

After having clamped the form-tool or formgauge on the work-table 39 and after having stretched the drawing of the pattern desired on the drawing board 34, the tracing device 50 on the end of the long arm 45 of the pantograph is moved from a starting point to a further point to be ground. The pantograph system moves the axis of the optical system to that point of it to which the work-piece is to be ground, in other words the axis of the optical system marks the position of the point to which the form-tool or form-gauge is to be ground. This point is observed simultaneously by means of the projection device. On the screen or projecting plane this fixed point and the central point of the image are one. It can be marked by a reticule drawn upon the screen or the fixed point can appear projected on the screen or plane. The point of the pattern line traced by means of the tracing device at the free end of the long pantograph-arm, and the actual point on the form-tool or form-gauge fixed by the optical axis,-and the central-point of the image on the screenthese three coincide. Now, by illumihating the form-gauge or'form-tool from below or from above the image of the unfinished formgauge or form-tool extends beyond the central point on the screen, and this part which extends must be ground away. For this purpose the 4 grinding disk while rotating moves up and down and must .be graduallymoved in against the edge cranks until it has ground ofi the extending parts of the'form-gauge or form-tool, i. e. until the 'aaaaeeo finished point ofthe workpiece coincides with the fixed point on the screen. Then a further point of the pattern is traced and this process is repeated. In this way the optical axis strikes each time a point on the form-gauge or form tool which lies besides the last one ground until the repeated grinding operation has finished the desired workpiece.

'The ratio of the enlargement of the image on the screen is about 20 to 1; that is to say, the

area shown as silhouette on the projection plane is about 20-times greater than the area covered by the objective lenses of the optical system. Observation on such an enlargement does not I always satisfy the demands of required exactness.

48 is constructed as a gangway 61 for a slide 62 which slide is used as a frame to carry two upper parts of the optical system consisting of an upper set of lenses 63 of a microscope at one end of the frame and. also a set of lenses 64 with mirror 65 to complete the device of a projection apparatus on the other end of the frame. On the gangway ii are two stops 6G and 61 to limit the scope of motion of the slide. If the end of the slide 62 which carries the set of lenses 64 with mirror 65 is moved over the lower part of the optical system until it strikes the stop 66, theprojection apparatus is completed, and the spot 1 to be ground may be observed as silhouette on the projection plane. The distance of the plane from the mirror 65 can be adjusted in order to produce sharp and clear images. The slide when in the position to complete the projection apparatus is arrested by means of a tapered pin 68 which passes through the hole 62a in the slide 62 into a hole 10 of the gangway 6|.

If the end of the slide 62, which carries the upper set of lenses 63 of the microscope is moved over the lower part 60 of the optical system until it strikes the stop 61 the microscope. system of observation is completed. For this purpose withdraw the pin 68 from the hole 10 and move the slide 62 till it strikes the stop G'I'and insert the pin 68 through hole 62a into hole 69. The microscope part for observation now rests over the lower part 60 of the optical system (see Fig. 4), and the spot to be ground may be observed by means of the microscope. 4

Instead of using aslide 62 as a frame on which the upper parts 63 and 64-65 are mounted, a turntable 13 may be used.. This design is shown in Fig. 5. The upper end of the inner bushing has been shaped into a flange and united into one piece with the short arm 15. A bolt 14 is screwed into this flange acting as a pivot around which the turntable is rotatorily mounted. This turntable 1-3 carries the said two upper parts of the optical system, namely: an upper set of lenses [6 to complete the microscope. and a set of lenses 'I'I with mirror 18 to complete the projection apparatus. is mounted on an are or. circle, the axis of which lies in the center of the bolt 14. By turning the turntable 13 either the upper part of the micro- Each of the two upper parts.

scope or the upper part of the projection ap-.

paratus completes with the lower part of the optical system 60 the desired means of observation.

Two stops I9 and 80 will halt the turntable I3 in its desired position for observation and this position can be secured by means of a tapered pin 8| in much the same way as is used in case of the slide.

The work with an optical profile grinding machine fitted with the dual system of observation describedabove is as follows:

The mechanical operation of the machine is the same as is described above in the machine with only the projection device. However the observation of the grinding process can be made either by means of the projection apparatus or by means of the microscope. If the projection apparatus is desired the frame supporting the two upper parts of the optical system is brought in the position where the set of lenses with the mirror complete the projection device. Then the silhouette of the point to be ground is projected on the plane or screen and the operator may observe it while grinding the spot to within a fraction of the desired point to be reached. In order to observe the grinding process from now on with a greater exactness the operator shifts the frame which supports the two upper parts of the optical system in the position where the upper set of lenses complete the microscope. The observation of the grinding process can be observed from this point on with a greater exactness because the ratio of the enlargement of the microscope ently are avoided.

I claim: 1. An optical profile grinding machine for the grinding of form-gauges or form-tools said ma.-

the grinding-disk on the form-tool or form-gauge and apparatus to complete the means to observe in enlargement point by point the path of the grinding-disk.

2. An optical profile grinding machine'for the grinding of form-gauges or form-tools said machine consisting of a base, a structure on which the form-gauge or form-tool is clamped, a construction facing this structure on which the grinding-disk is movably mounted, a drawingboard on which may be stretched an enlarged pattern-drawing, a long arm and a short arm and two connecting rods, forming a pantographsystem, a tracing device at the free end of the long arm for tracing point by point the lines on the pattern drawing. and a set of lenses mounted into the short arm of the pantograph and forming the lower part of an optical system for observing the path of the grinding-disk on the formtool or form-gauge, an upper part of a. projection apparatus which completes the optical system and which under enlargement allows ob-- servation point by point of the path of the grinding-disk and illumination devices to illuminate the point of grinding.

3. An optical profile grinding machine for the grinding of form-gauges or form-tools said machine consisting of a base, a structure on which the form-gauge or form-tool is clamped, a construction facing this structure on which the grinding-disk is movably mounted, a drawingboard on which may be stretched an enlarged pattern-drawing, a long arm and a short arm and two connecting rods, forming a pantographsystem, a tracing device at the free end of the long arm, for tracing point by point the lines on the pattern-drawing, and a set of lenses mounted into the short arm of the pantograph and forming the lower part of an optical system for observing the path of the grinding-disk on the form-tool or form-gauge, a, set of lenses and a mirror, and a projection plane and a framewhich carries these lenses, mirror and projection plane as the upper part of the optical system which upper parts complete with the lower part of the optical system a projection apparatus which under enlargement allows observation point by point of the path of the grinding-disk and sources of illumination to illuminate the point of grinding both from above and from below.

4. An optical profile grinding machine for the grinding of form-gauges or form-tools, said machine consisting of abase, a structure on which the form-gauge or form-tool is clamped, a construction facing this structure on which the grinding-disk is movably mounted, a drawingboard on which may be stretched an enlarged pattern-drawing, a system having a tracing-device for tracing point by point the lines on the pattern-drawing, a set of lenses forming the lower part of means for observing the path of the grinding-disk on the form-tool or form-gauge and a dual device for observation of the point of grinding, having one upper set of lenses which with the lower set of lenses, complete a microscope, and a second upper set of lenses which, with the lower set of lenses, complete a projection apparatus, and illumination-devices for illuminating the point of grinding.

5. An optical profile grinding machine for the grinding of form-gauges or form-tools said machine consisting of a base, a structure on which the form-gauge or form-tool is clamped, a construction facing this structure on 'which the grinding-disk is movably mounted, a drawingboard on which an enlarged pattern-drawing may be stretched, an em fastened at right angle mounted into the free end of this arm, an inner bushing rotatably mounted within the outer bushing, a pantograph system consisting of a short arm, fastened on top of the inner bushing, a first connecting rod linked on the free end of the short arm, a second connecting rod, fastened on top of the said outer bushing and parallel to the first connecting rod, and a. long arm linked to the free ends of the connecting rods and parallel to the short arm, a tracing-device mounted on the free end of the long arm of said pantograph-system, and a set of lenses mounted into the short arm of the pantograph and forming the lower part of means to watch the path of the grinding-disk on the form-tool or formgauge, a gangway constructed on top of the inner bushing, a .slide movably mounted on said gangway which slide carries at one end one upper set of lensesto complete a microscope and at the other end a second upper set of lenses and a mirror and a-projection plane to complete a projection apparatus, means to limit the scope of motion of said slide and sources of illumination for illuminating the point of grinding both from above and from below.

6. An optical profile grinding machine for the grinding of form-gauges or form-tools said ma-- chine consisting of a base, a structure on which the form-gauge or form-tool is clamped, a construction facing this structure on which the grinding-disk is movably mounted, a drawing-board on which may be stretched an enlarged patterndrawing, an arm fastened at right angle on top of the column, an outer bushing rotatably mounted into the free endot' this arm, a pantograph system consisting of a short arm which short arm is a part of a. flange at the upper end of an inner bushing which inner bushing is rotatably mounted within the outer bushing, a first connecting rod linked on the free end of the short arm, a second connecting rod fastened on top of the said outer bushing and parallel to the first connecting rod and a long arm linked to the free. ends of the connecting rods and parallel to the short arm, a tracing-device mounted on the free end of the long arm of said pantograph system, and a set of lenses mounted into the short arm of the pantograph forming the lower part of means to watch the path of the grinding-disk on the form-tool or form-gauge, a turn-table rotatably mounted around a bolt over the flange at the upper end of the inner bushing of the pantograph, which tum-table carries one upper set of lenses to complete amicroscope and a. second upper set of lenses and a mirror and a projection plane with reticule to complete a projection apparatus, means to limit the scope of motion of said slide, and sources of illumination for illuminating the point of grinding both from above and from below.

REINHARD MAX WOHLFAR'IH.