US2386145A

US2386145A - Dividing mechanism

Info

Publication number: US2386145A
Application number: US504513A
Authority: US
Inventors: Ruysdael Basil
Original assignee: LOUIS M RABINOWITZ
Current assignee: LOUIS M RABINOWITZ
Priority date: 1943-09-29
Filing date: 1943-09-29
Publication date: 1945-10-02
Anticipated expiration: 1962-10-02

Description

B. RUYsDAEL DIVIDING MECHANISM Filed Sept. 29, 1943 s sheets-sheet 1 Oct. 2, 1945. B. RUYsDAVEl. l 1 2,386,145

' DIVIDING MEcHAN'IsM Filed sept.4 29', 1943 3 sheets-sheet s' INVENTml Patented Oct. 2, 1945 ,UNITEDTSTATS PATENT 2orrlcr.

` BaslRuys'dael, New York, N. Yi, assignor of one.- l halflto Louis M, Rabinowitz, Nev:r York, N. Y.

Application september 291, 1943, serial No. 504,513 aclaims.V ('01. sx1- 56) This invention generally relates to 'dividing mechanism and, more specifically, to dividing at` tachments Yadaptedfor use on milling machines, and the like, in the cutting ofgears or similar operations, and commonly known as dividing or indexing heads. f f The dividing heads heretofore vgenerallyl employed are of more or less complicated and ex` pensiveconstruction arid their use requires considerable practice and study'on vthe part of the operator. By` reason o'f thei`rconst1uetion and the principles on which theyfare based, the range of operation of these devices is somewhat limited and, in many instances,` complicated mathematical' operations must be Yperformed to set the mechanism for the desired number of divisions with considerable chances for error, as is well known to those skilled in the art.

Itis, therefore, the general object of this invention to provide a dividing head of an entirely novel character which is simple and inexpensive so as t be within the reach of experimenters, and which embodies novel index means adapted to aiTord much greater ease' of operation as cornpared with the devices of the prior art, while insuring absolute accuracy of divisions.

More specically, it is a further and important object of the invention to provide a dividing head wherein all forms of holed or notched index plates or of index gears are dispensed with, and which has such a broad range of operation that. any number of divisions maybe obtained, as weil as complicated Vernier divisions. .Y

The invention furtheraims at providing a dividing head of the character described, comprising only a limited number of parts, easily replaceable whenever necessary, the construction and the manner of operation of the device being such as to eliminate any possibility of cumulative error due to wear or slack.

These and other objects of the invention will become apparent in the following description of a preferred embodiment of the invention illustrated Figure 4 is a front elevation of the same mechanism.

'Figure '5 is an enlarged view, on line 5-5 of Figure 1, showing a portion of the plate carried bythe spindle of the dividing head andthe graduations provided on said plate.

Figure 6 is a` fragmentary enlarged view, on line 6 6 of Figure 4, of`one of the index dials of the device.

Figure '7 is a similar fragmentary enlarged View, on line `I-'I of Figure 1, of the other,` or main index dial of the device. I

Referring now in detail tothe drawings, wherein like characters of reference are employed to designate the similar partsin the various views, ID indicates the base or support of the dividing mechanism adapted to be mounted on the table I I of a milling machine. A horizontal spindle I2, rotatably mounted in base I0, and suitably held therein against axial displacement, carries, at one enda plate I 3 rigidly connected to the spindle for rotation therewith and a conventional driver I 4 for a dog I 5, for use when the workpiece is mounted Abetween centers, as in the showing of FigureV 1. v

As shown in detail in Figure 5, the rear face of plate I3 is' provided with degree graduations that are readable against an indicator member I1 supported by the base Ill, as at I8; lock handle I9 actuates a conventional mechanism in base I Il for locking the spindle in anydesired angular position during operation of the device.

A worm gear 20, suitably connected to `spindle I2 for rotation therewith, meshes with a single thread worm 2| provided on a shaft 22 rotatable in a supporting member 23 and having a portion projecting downwardly from` said member; as worm gear 2U has seventy-two teeth, a complete revolution of shaft 22 and Worm 2Iresults in a rotation .of five degrees of the worm gear and therefore of the spindle I2. Member 23 is carried by a support 24, to which it is suitably fastened, as by means of screws 25, support 24 being in turn bolted to base I0, as shown at 26;

A disk 21, which may be designated as the main index dial of the dividing headby reason oflits function, is fastened to the aforementioned downwardly projecting portion of` shaftV 22, as shown at I6, for rotation with said shaft and is provided, on itsupper face, with a scale consisting of five hundred uniformly spaced divisions, every tenth division being marked with a longer line and a numeral asshown in Figure '7; an indicator member 28 secured to `abracket 29` carried by member 23, as at 30,4 is provided for the dial.

spindle of one hundred-th of a degree.

carrying index dial 21 there corresponds a five degree rotation of spindle I2 and plate I3, it will be apparent that the rotation of the dial through anV angle dened by ten of the divisions indicated by the longer lines will determine a rotation of spindle I2 and plate I3 through an angle of onetenth of one degree, and a rotation of shaft 22 through an angle defined by two adjacent divisions therefore will result in arotation of the VIt is therefore evident that a rotation of the spindle through one-hundredth of a degree, which yis accurate enough for ordinary gear work, can be easily controlled by means of the indexV dial 21.

Greater accuracy in indexing the spindle is, however, attainable by means .of the device that will now be described. A gear 3l mounted on shaft 22 meshes with a pinion 32 secured to the l-ower end of a second vertical shaft 33 which is rotatable in a bushing 34 mounted in member 23 and held against rotation therein as by means of set screw 35; a portion of shaft 33, having .a shoulder 3-1, extends upwardly from member 23 for rotation within a hollow member .or sleeve 36 interposed between the upper' face of member 23 and shoulder 31 to prevent axial ,displacement of shaft 33 and to' insure proper meshing of gear 3| and pinion 32. As shown in Figure 2, gear 3l is of smaller diameter than index dial 21 so as not to interfere with the reading of the graduations of .this dial. f I t A. Second index dial 39, Similar to index dial 2 and likewise provided with a scale consisting of ve hundred uniformly spaced divisions and longer lines to mark every tenth division, is suitably secured .to the upper end of shaft ,3.3, as at 40, the divisions beine readable against an indicator member k4H carried by the base Il). A s the ratio of the gear coupling .3l-.f3.2 has been made 10 to i the embodiment illustrated, it will be apparent that the rotation af index dial 39 through an angle defined by two adjacent divisions will result in a rotation of spindle I2 of oneinonsandih. ci a degree, ,andV that such .an aneular movement, which is Asulicient for practically A perfect indexing accuracy, can b e easily controlled by means of index dial 39.

With a 10W power magnifying glass, that can be conveniently mounted on indicator member .4 I movements of'dial 39 of a half graduation can be easily checked, thereby controlling the rotation o f spindle I2 even through an angle of half a thousandth of a degree.

`The manner of operation of the dividing head will be apparent from the foregoing description. The work piece may be mounted on the milling machine Vin any suitable manner, as in the show.- ing of Figure 1, which illustrates the cutting of a gear blank 4 2, mounted between center 45 of spinolle I2 and center 46 of a conventional tailstock hby means of a cutter t3. The operator determines the angular interval between tWO .Successive divisions in relation to the total number 0f divisions desired, which will represent the initial setting of the dividing mechanism, and manipulates the main index dial 2'I and the index dial 39 thereby rotating spindle I2 until the desired angle` has been obtained; the main index dial may be set within one degree of the desired angle and the second dial moved on to the thousandths of degree required. Should the setting be inadvertently passed, the spindle can be rotated back a degree, or so, and the mechanism reset to take up any slack.

The spindle is then locked by means of lock handle I9 and the first division is effected, the spindle being then rotated, of course, by the same angular amount as many times as necessary to obtain the desired number of divisions. As the train moves always in the saine direction during the dividing operation, there is no objectionable slack or backlash to the train, and no vibration affects the setting due to the fact that the spindle is yirmly locked in the proper angular position after each setting.

The angular interval required for any given `number of divisions is determined by means of tables that show, at a glance, in degrees and thousandths of degree, the angular interval between any two successive divisions and the total angu- -lil' displacement of the spindle in any phase of the dividing operation. If, for instance, 38 divisions are desired, the tables will show an angular interval between any two successive divisions of 9.474" (which will be the initial setting of the dividing head) and a total angular displacement for, say, the fourteenth division of 132.6322 the setting can be rin this manner continuously checked during the dividing operation as the total angular displacement of the spindle is readable, at any time, on the index dials. Obviously, the angular values given in the tables cannot always be absolutely correct as the third decimal figure must, in some instances, be approximated; however, the error is insignificant and compensated back and forth in the tables, to avoid the possibility of cumulative error, so that it does not affect in any way the accuracy of the divisions.

The foregoing description .clearly lillustrates the advantages of ,the novel dividing mechanism as compared with the devices of the prior art. The dividing head is of simple and inE expensive construction, it comprises only a limited number of parts, easily assembled and disassembled for replacemeritof any part as might be required due to wear or other causes; cumulative errors due to Wear or slack are entirely eliminated.

The adoption of index dials graduated in degrees and decimals of degrees, and the arrangement of the parts, permit of great accuracy of divisions and of an extremely broad range of operation; furthermore, the operation of the mechanism is rendered so simpleand easy that anyone can use the device provided he is capable of reading the graduations on the index dials.

While I have described the invention substantially with reference to a preferred embodiment thereof, it will be understood that many modifications may be made in the structure described in the specification and illustrated in the drawings without departing from the spirit of the invention or exceeding the scope of the claims.

I claim: A

l. A dividing mechanism comprising a base, a horizontal spindle rotatably mounted in Vsaid base, a plate and a worm wheel fastened to said spindle for rotation therewith, a scale on said plate, a vertical shaft rotatably supported externally of the base and having a worm meshing with the worm wheel fastened to the spindle, said worm and worm wheel being so proportionedy as to determine a rotation of the Spindle through an angle of ve degrees for each revolution of the shaft, a second vertical shaft rotatably supported externally of the base, constantly meshing gear means for driving the firstmentioned shaft at the reduced rate of one to ten relative to said second shaft upon rotation of this latter, discs fastened to the shafts operable to rotate the same, and scales on said discs, said scales cooperating with the scale on the plate fastened to the spindle to indicate the amount of angular displacement imparted to the spindle through the rotation of the shafts.

2. A dividing mechanism comprising a base, a horizontal spindle rotatably mounted in said base, a plateand a worm Wheel fastened to said spindle for rotation therewith, a scale on said plate, supporting means removably carried by the base externally thereof, a shaft rotatably mounted on said supporting means and having a Worm meshing externally of the base with the Worm wheel fastened to the spindle, said worm and worm. wheel being so proportioned as to determine a rotation of the spindle through an angle of ve degrees for each revolution of the shaft, a second shaft rotatably carried by said supporting means, constantly meshing gear means for driving the first-mentioned shaft at the reduced rate of one to ten relative to said second shaft upon rotation of this latter, discs fastened to the shafts ,operable to rotate the same, scales on said discs, said scales cooperating with the scale on the plate fastened to the spindle toindicate the amount of angular displacement imparted to the spindle through the rotation of the shafts, and means independent of the discs for locking the spindle in any angular position.

3. A dividing mechanism comprising a base, a horizontal spindle rotatably mounted in said base, a plate and a worm wheel fastened to said spindle for rotation therewith, a scale on said plate, a vertical shaft rotatably supported externally of the base and having a worm meshing'with the worm wheel fastened t0 the spindle, said Worm and worm wheel being 'so proportioned as to determine a rotation of the spindle through a specific part of a revolution for each revolution of the shaft, a second vertical shaft rotatably supported externally of the base, constantly meshing gear means for driving the firstmentioned shaft at a fixed reduced rate relative to said second shaft upon rotation of this latter, discs fastened to the shafts operable to rotate the same, and scales on said discs, said scales cooperating with the scale on the plate fastened to the spindle to indicate the amount of angular displacements imparted to the spindle through the rotation of the shafts.

BASIL RUYSDAEL.