US2263788A

US2263788A - Machine for generating multisided apertures

Info

Publication number: US2263788A
Application number: US228307A
Authority: US
Inventors: Schroder Hans Joachim
Original assignee: Messerschmitt Bolkow Blohm AG
Current assignee: Airbus Defence and Space GmbH
Priority date: 1937-09-06
Filing date: 1938-09-03
Publication date: 1941-11-25
Anticipated expiration: 1958-11-25
Also published as: CH205261A; FR842761A; GB508443A

Description

Nov.- 25, 1941. H. J. SCHRODE R MACHINE FOR GENERATING MUL'IISIDED APERTURES Filed Sept. 5, 1958 5 Sheets-Sheet l H. J. SCHRCSDER Nov. 25, 1941.

- MACHINE FOR GENERATING MULTIICSIDED APERTURES Filed Sept. 3, 1938 5 Sheets-Sheet 2 1941- H. J. SCHRODER MACHINE FOR GENERATING MULTISIDED APERTURES- 5 Sheets-Sheet 5 Filed Sept. 3, 1938 Fig. 5

lllllllltll H lllllllll Hlll //7 venton' Nov. 25, 1941. H. J. SCHRODER 2,263,788

MACHINE FOR GENERATING MULTISIDED APERTURES Filed Sept. 5., 1938 s Sheets-Sheet 4 Nov. 25, 1941. H. J. scHRODER MACHINE FOR GENERATING MULTISIDED APERTURES 5 Sheets-Sheet 5 Filed Sept. 3, 1938 I Inventor: 660.: 7a'acfiz'm Sammie 4 with the aid of th 'accompanying Patented Nov. 2 5a1941 I TED; STATES PATENT. Z series MACHINE For:

GENERATING MU 'rrsmEn anemones Hans Joachim Schriider. Dessam Germany, as-

signor, to

Junkers Flugleugmnd Motoren- Aktimsesellschflt, Des'sau, Germany," a ration of Germany Application September-3,1938, sens! naafzaso'z.

. In Germany September 6, 1937 z This invention relates a machine for generating multi-sided apertures'which are suiilciently accurate in form to merits.

My invention is based on the fact that certain fulfill all ordinary requirecycloids are generated around the perimeters of polygons having rounded corners; hypocycloids are important in the development 01 apertures which are multi-sided in section. The curves referred to are utilized in the following mariner:

While the cutting edge of my tool rotates once about the axis of the toolholder, the latter also rotates several times in the. opposite direction. I

about the axis of the multi-sidedaperture'being generated. Moreo'verthe ratio of the speeds of rotation of the tool about these two axes determines the number of sides of the multi-sidedl Again to produce multi-sided' aperaperture. tures having flat sides the radial distance of the cutting edge of the tool from its axis must be correctly proportioned to the distance between the tool axis and the axis of multi-sided -aper-' ture.

It is an' object of the invention to provide a machine for generating multi-speed apertures all the lateral walls of which are of equal length and disposed at a common angle to one another and by which all multi-sided apertures cut when the device has once been set are identical. Moreover the machine may be so set that all, the'sides of the multi-sided aperture are flat.

Another object of theinvention is to provide a machine for generating multi-sided apertures which is simple in construction, has only few moving parts, requires very little attention when in ope tion, and which does not-subject the cutting 01 to excessive wear.

A further object of the invention is to provide .a machine for generating multi-sided apertures wherein the tool spindle is rotated through gearing, and wherein the spindle, which rotates at a constant speed, is simultaneously rotated about a secondaxis in alignment with longitudinal axis of the aperture beinggenerated.

Yet another object of the invention is to provide a machine for cutting multi-sided apertures wherein the ratio of the cooperating gears con- ZIP , lg-urel.

I Figure '1 is a longitudinal sectionshowlng one embodiment of-theinvention.

Figure 2 is a section on the line" IIII of somewhat imodified construction.

Figure 3. a 1 a Figure-'5 is a longitudinal section showing another modification. 1 I I Figure 6 i a section on VI--VI of Figure 5.

. Figure '7 is a'partial longitudinal section show-- ing a slight further modification. r s

Figure 8 is a longitudinal section showing an- 3 showsa longitudinal section of a I Figure-4 is a section on the line IV- I V. cf

othenmodified form of the invention wherein" the axis of the tool spindle islinclined to the axis of the multi-sidedaperture to be generated.

Figures 9 and 10 are'enlarged sectional details showing .methods of adjustablymounting: the' tool for angular movement upon the tool spindle. J Referring first to Figures 1 and 2, the drive spindle or shaft I has a shank I mounted therein neath the spindle I and is" rotatably supported in a' fixed frame 3. The said. shank 2 isaiso provided with-an eccentric tapered bore to re- 'ceive a cone 4. Fixed eccentrically-upon thev latter is a gear 5,'and'projecting from the opposite fac ofzthe said gear andconcentrictheretrols the number of sides generated around the aperture; and wherein by varying the radial length of projection of the cutting tool from the tool spindle axis the length of the sides of the multi-sided aperture generated is changed.

Some of the preferred embodiments of the invention are hereinafter more fully described drawings in which:

with is a guide pin 6 which is rotatably mounted in a bearing I formed in a movable guide 8.

' for'rotation therewith. The shank! projects be- Mounted for rotation in the latter is a tool spindie I0 upon the upper extremity of which a gear 9 is concentrically fixed which mesheswltl the gear 5. II denotes the operating extremity of the tool spindle I0 which in the present instance is integral with th latter.- I2 is a tool bit carried by the spindle I0 and projecting. radially therefrom to cut the'lateral faces of an aperture It due to thefact that the axis C :of the gearS and its pin 6 is'spaced a distance r'irom the axis B I a of the drive spindle I rotation of the latter moves 4 the-guide 8 around an axis M whlchmust coin- .cide with. the axis of the multi-sided'aperture- I515 be generated. Moreover the axis M is parallel 2 to and spaced from the axis A of the tool spindle a distance 1' which isequal to the distance r between the axes B and C.

The circular pathof movement of the guide is insured by the carriage l4, movement of which 5 occurs simultaneously in two directions at right angles to one another along the ways I'l and I8 and I9 caused by the rotation of the eccentric pin 6. The distance r is regulated by the rotary position of the cone 4 in the eccentric bore of the shank 2 because the said cone is eccentric with the gear 5 and therefore may be turned so that its eccentric mounting in the shank 2 either through the gears-38 and 31. The axis M should complements or offsets the eccentricity of the gears 5-. The ratio of the teeth in the two gears 5 and 9 controls the shape of the multi-sided apertures generated;. with these gears proportioned 1:2 a triangular aperture. is obtained; and when proportioned 1:3 the aperture is made rectangular.

In the modification shown in Figures 3 and 4, 29 denotes portions of a fixed frame in which the extremities of two 'spaced parallel columns 28 are supported. Bushings 24 eccentrically bored at 2'! 'are mounted for rotation about columns 26 and have gears 25 fixed thereon. A guide 2| has a spindle 22 rotatably mounted therein, and fixed upon the latter is a gear 26 opposite sides of which mesh with the gears 25.

Integral with the guide 2| areopposed lateral extensions 23 through which the bushings 24 extend and wherein they are rotatably mounted.

A universal joint 30 is secured both to the upper extremity of the tool spindle 22 and also to a drive spindle or shaft 3| which turns about a fixed axis B The eccentricityof the tool spin-,- dle 22 relative to the drive shaft 3|, which is represented by the distance r between the drive shaft axis B and the axis A of the tool spindle 22, must be equal to the distance 3' between the axes D of the columns 28 and the axes E'of the bushings 24. It is therefore obvious that the rotation of the tool spindle 22 about its own axis A imparts rotation to the bushings 24 through the

gearing

26 and 25, and, due to the eccentric mounting of the saidbushings upon the fixed columns 28, rotation is also imparted to the guide 2|, through which the vtool spindle 22 extends, about the said axis B -Obviously,

in this form of construction the guide 2|, the

bushings 24 and the

gears

25 and 26 may all be moved axially together upon the columns 28 to provide axial feed for the tool spindle 22; moreover in this form of construction the axis B is in alignment with the 'axis about which the guide 2| is rotated and must therefore be in alignment with the axis of the multi-sided aperture being generated. v

In Figures 5 and 6 the tool spindle 32 is eccentrically mounted in a guide 33, and in order to make the view shown in Figure 5 clearer this eccentricity is perpendicular to the plane on which the section is taken. The guide 33 is concentrically supported in a stationary frame 34- so that its axis is coaxial with th axis M of the latter. The guide 33 is in the present instance rotated by means of a belt 35 passingthrough a suitable opening .36 in the frame 34 and around the guide periphery though other means may coincide with the axis of the multi-sided aperture to be generated. In this case the cross sectional form of the aperture is dependent upon the total ratio of the. two coacting pairs of gears. For instance, a 3:2 ratio produces a triangular hole, and a 4:3 ratio produces a rectangular hole.

Figure 7 shows a slight modification of the construction just described and illustrates one means for varying the distance 1 between the axis M and A, and thus the. diameter of the circular path around which the axis of the tool spindle travels as it rotates about its own axis. The bore of the guide 33a is longitudinally inclined and a-bushing 54, the periphery of which is correspondingly inclined, is longitudinally movable therein, so that the bore of the bushing is parallel with the axis M and eccentric with theperiphery of the guide 3311. Obviously, by adjusting the longitudinal position of the bushing in its guide in the direction of the arrows X or Y the distance 1 may be varied.

However in order to make this arrangement operative in the construction shown in Figures 5 and 6 the

gears

31 and 33 must b changed and another set of larger or smaller diameter used for each vertical setting of the bushing 54, which must therefore be at certain predetermined ver- 5 tical positions so that the set of

gears

31 and 38 employed mesh properly with one another. Similarly such an adjustment may also be employed in the arrangement shown in Figures 3 'and '4 by changing the

gears

25 and 26 for others 0 of larger or smaller diameter.

Figure 8 shows an inclined tool spindle 43 having a bevel gear 44 fixed upon its upper extremity which travels around an internal gear 46 provided within a stationary housing 45. The axis A of the spindle is inclined at an angle a to the axis M of the frame and intersects the latter at the point K below the said frame. The tool spindle 43 is in its inclined position eccentrically mounted in a guide 41 which is coaxial with the internal gear 46 insomuch that the axis A intersects the'bushing axis M at K beneath the bottom of the said guide. The guide 41 is connected to a drive spindle or shaft 48 which be employed for turning said guide. Fixedupon 7 the spindle 32 is a gear 31 which meshes with a gear 38 upon a stub shaft 33 supported in a laterally projecting member 46 integral with the said guide 33. Fixed upon the shaft 39 is a secis mounted for rotation in the 'upper portion of the housing 45 and extends therethrough in alignment with the axis M.

When the shaft" and the guide 41 are turned the bevel gear 44 travels around the internal gear 46 and the tool spindle 43 is rotated about both axes A and M. The proportionate sizes of the

gears

44 and 46 control the cross-sectional form of the multi-sided apertures generated by the cutting edge S of the tool 49. For instance, if the ratio of the gears is 3:2 a triangular hole is formed and if the ratio is 4:3 the hol generated is rectangular. From the foregoing, it will be clearly seen that the tool spindle 43 turns both about its axis A and about the axis W of the guide 41. Moreover on account of the inclination of these two axes to one another, the

transverse distance between them varies accord-.

section K. ond gear 4| which engages a gear 42 concentri- The cutting edge S of the tool must be sufwith the internal gear through which said spindle is turned by the rotation of the guide, and a tool carried by the spindle, said tool having a Figure 9 is an enlarged diagrammatic view showing a modification of the structure shown in Figure 8 wherein the tool spindle 43a is tubular and the point K is located beneath the cut-- ting edge S of the tool 49. Axially movable in the spindle 43a is a rod 52 having a laterally disposed pin 60 projecting therefrom. Formed in the tool spindle 43a is an inclined guide 6| in which a toolholder 50 is slidably mounted. The outer extremity of the pin 60 is a sliding fit in an aperture 50a in the toolholder 50 so that it may slide therethrough as the rod 52 is moved in the tool spindle 43a and the said toolholder is correspondingly moved in the guide 6|. construction it is obvious that upon feeding the rod 52 in the guide 43a the cutting edge S of the tool 49 must travel along a line S'-K parallel with the base of the guide 6| that is at an angle 3 to the axis A of the tool spindle; and a tie-'- notes the angle between the axes A and M The arrangement shown in Figure 10 is practically identical to that shown in Figure 9 except that the point K, which again designates the intersection of the axes A and M is located above instead of beneath the tool 49, and therefore the line S-K lies above instead of beneath the said tool. The rod 53 and the-tool holder and the pin 60a correspond to the rod 52, the toolholder 50 and the pin 60 above described. a again denotes the angle between the cutting edge spaced axially from the point of intersectionand displaced laterally from the axis of the spindle.

2. A machine for generating multi-sided apertures comprising a frame, a drive shaft mounted for rotation therein, a guide fixed on the shaft for rotation in the frame, an internal bevel gear on the frame, a spindle mounted for rotation in the guide at an inclination to the guide axis, said guide and spindle axes being adapted to inter sect, a bevel gear fixed on the spindle and meshing with the internal bevelgear whereby the spindle is turned by the rotation of the guide,

Inthis' and a tool carried by the spindle, .said tool having a cutting edge spaced axially from the point of intersection and displaced laterally from the axis of said spindle.

ported by said spindle, said tool including a cutting edge displaced laterally from the rotative axis of the spindle, means for rotating said guide, I

and cooperating means on said frame and spindle whereby rotation of the guide causes rotation of the'spindle about its rotative axis to thereby impart to the cutting edge of the tool a axes A and. M and B the angle between the line S-K and the axis A The purpose of the embodiments shown in Figures 9 and 10 is to provide means, by feeding the rod 52 or 53 inthe spindle 43a, for forming multi-sided apertures the walls of which are all uniformly inclined to the longitudinal axis M and the latter of course also coincides with. the

' axis of the multi-sided aperture being generated. In other words the apertures thus formed are of different sizes at the top and bottom, thus having the shape of a truncated pyramid.

It will of course be noted from the drawings that as above stated the tool spindle rotates about its own axis in the opposite direction to that in which it travels around the second axis.

a spindle mounted for rotation in the guide about its axis, saidaxis being angularly disposed withv reference to the guide axis and adapted to intersect the same, a gear on the spindle meshing hypocycloidal movement with reference to a circular line'about the rotative axis of the guide.

4. Mechanism of the class described comprising a frame, said frameincluding a circular portion having a driving surface around its internal periphery, a guide rotatable in the frame, a tool spindle rotatable in the guide with its axis of rotation eccentrically disposed with relation to the rotative axis of the guide, said spindle including a circular portion having a driven surface around its external periphery in operative engagement with the driving surface in said frame, means, for producing relative rotation of said frame and-guide, and a cutting tool positioned by said spindle.

5. Mechanism of the class described comprising a frame, said frame including a circular porguide, and a cutting tool positioned by said spindle.

6. The mechanism set forth in claim 5 wherein the cutting edge of the tool is laterally displaced from the spindle axis and axially displaced from the intersection of the guide and spindle axes of rotation.

,l-IANS JOACHIM scnaonna.