US1642077A - Gear-tooth gauge - Google Patents

Description

J. A. MCINTOSH GEAR TOOTH GAUGE Sept. 13; 1927 1,642,077

Filed June 19, 1920 2 Sheets-Sheet l (fez neg Sept. 13, 1927.

J. A. M INTOSH GEAR TOOTH GAUGE Filed June 19, 1920 2 Sheets-Sheet 2 Patented Sept. 13, 1927.

UNI ED STATES "PATENT OFFICE.

JAMES A. HOIli'I-OSK, OF lJETBOIT, MICHIGAN, ASSIGNOR TO THE LEES-BBADNEB COMPANY, 01 CLEVELAND, OHIO, A OORPOBATIONOF OHIO.

GEAR-TOOTH GAUGE.

This invention relates to gauges for indicating the condition of gear teeth being cut. At the present time, in setting up a machine for cutting gear teeth, it is the practice to 6 cut a gear and then roll the gear into contact with another gear and solely by observation and feel determine whether t e teeth are accurately and properly cut to get the proper meshing action between the teeth of 10 the two gears. It is the princi al ob ect of the present invention to provi e an instrument which will register any inaccuracies by thousandths of an inch or less, in a gear 5' which is not out true.

In the drawings,-

\ Fig. 1 is a plan view of the instrument.

Fig. 2 is a side elevation of the. same,

partly in section. I

Fig. 3 is a sectlon on the line 3-3 of Fig. 2.

a designates a base that may be bolted thru the slot 6 to a suitable-su port. This base is recessed to form a sli e-wav a: in which travels the slide 0 actuated by the winged screw d against the resistance of. the spring e. This slide is provided with an upstanding post f-which 'ournals a reel g adapted to take a steel and h fastened thereto b the clamping block i. The

center (considered in the direction of its thickness) of this band upon this reel registers substantially with the pitch circle of the gear. which is bolted to the externallythrea ed hub y of the reel by means of the 85 nut in. The op osite end of the band h is clamped to the d by the block m. A torsional spring n has one leglattached to the slide 0 and the other to t e reel g. (See Fig. 2.) This keeps'the reel turned to draw 40 the band taut at all times. The object of this band is to cause the gear 7' to so' rotate, when the slide 0 is moved inwardly against the tension of the spring 0, that it will develop its pitch circle into a straight line.

At 9 is shown a major slide adapted to be adjustably slid in ways H in the base a. The position of the slide 9 in the ways may be fixed by screws f-q. The slide 9 carries supports o -0 provided with rectangular ldeways oo'* in which is mounted for sliding movement transversely of the slide g, a minor slide 0, provid with a 1920. Serial No. 390,089.

point or projection p. The point p is shaped like a rack tooth and meshes with the teeth of the gear A lever 2,'-pivotally supported on the sli e g at 2 has one end in engagement with a notch z in the minor slide 0 and has the other and longer end in engagement w1th the stem .1 of an indicator 2, such as a Brown & Sharp indicator or any similar device. A centralizing mechanis'm is provided for normally maintaining the lever z and minor slide 0 in a central positlon and comprises a guide rod t su ported on posts u-a, a sleeve 8 loosely sli dable on the guide rod, and sprin s v'v between the ends of the sleeve 8 an the osts w-u. The lever .2 is pivoted to the s eeve When the gear 7' is rotated as above descrlbed, the teeth of the gear will mesh with the point p similarly as it would if it were one of the teeth of a rack.

The operation will be (perfectly plain. When the gear j to be teste ismounted on the post f, the slide 0 and the adjustable slide q are preferably in the positions shown in Fig. 1, so that the point p meshes with the gear teeth. Before the nut is tightened, the gear 1' is turned by hand counter clockwise until one of its teeth is in engagement or contactwith the surface p of the point p, this contact being resiliently maintained by the centralizing mechanism above described, as will be understood. Now, by turning the screw d .in one direction, the slide a is caused to move forward, the spring e taking up any lost motion. This unwinds the band h from the reel, causing the gear jto roll in the same way it would roll if it were rolling on a plain surface on its pitch circle, this operation serving to ut thettorsional s ring- 11. under tension so t at it maintains t e band It taut as rolling of the reel and unwinding of the band takes place. When the screw d is turned inthe other direction, the slide 0 is thereby moved back towards its starting position, and the torsion spring 7 rotates the reel 9 and gear in the opposite direction and thus takes up any slack in the band h which would otherwise occur therein. This is the movement the gear would take in traveling over a rack havin teeth accurately cut. Instead of traveling over a rack, t

e teeth travel over the point p connected with the indicating lever. Since the surface p of the point or tooth p is held in contact with the adjacent tooth face as above described, the point or 5 tooth 79 will be moved if the tooth face is inaccurate, and such movement will cause the lever z to rockand the amount of its movement will be registered onthe (hill of the indicator 2, thus indicating in fractions of an inch the amount of inaccuracy in the gear tooth face. In this way one face of each tooth, one after another, can be tested. Then by loosening the nut 11 and rotating the gear clockwise until the other surface 4* of the point or tooth 72 is engaged by the much better running of the machinery containing sets of gears. I

There are several well recognized circles in connection with calculating gears; for in stance, there is an addendum circle, a, root circle and any number of pitch circles the diameters of which do end upon the slope or pressure angle of th surfaces (in this case the surfaces 7) and p with which the gear to be tested is meshed. It will be obvious that my instrument, especially the band,

could be used to develop any one of these circles by simply changing the reel to accord with such circle. Hence I am not limiting myself in the claims directed to the specific means for developing a itch circle to a sintill till

gle circle. I have, there ore, seen fit to refer to such a circle generically as one of the gear teeth circles. i

What I claim is:

l. In a machine for the purpose specified, the combination of a gear support, means for causing a gear on said support to roll and develop a part of its pitch circle into a straight line, and testing means including a device yieldingly sup orted at the side of the tooth to he tested an in engagement therewith, so that, when the gear tooth is accurately out, the said means will not be to any appreciable extent displaced when the gear is caused to roll over the same in do veloping its said pitch circle, but, when the gear tooth is inaccurately formed, the same will be displaced from its normal position.

2. In a device for the purpose specified, the combination of means for sup orting a gear and causing it to roll and evelo a part of its pitch circle out in a straight lme, a. testing tooth, means for yieldingly supporting said tooth in a predetermined position with one face thereof adjacent to the face of a gear tooth of a gear on said supporting means so that, if the latter is accurately shaped, the said testing tooth will not. be a preclabl displaced when the gear tooth rolls over the same as the gear develops its pitch circle, but, when the gear tooth is inaccurately formed, the same will be displaced from its redetermined position, and means actuated y said testing tooth for indicating such displacement of the gear tooth.

3. In a device of the character described, the combination of means for sup orting a gear and causing it to roll and evelop a portion of its pitch circle into a straight lmo, a tooth in the form of a'rack tooth, means for yicldably supporting said tooth in a. predetermined position with one face thereof adjacent a gear tooth of a ear on said supporting means, so that wien the latter is accurately formed it will roll over the rack tooth without appreciably displacing the same when the gear develops its pitch circle into a straight line, but, when the gear tooth is inaccurately formed, the said rack tooth will be displaced, and indicating means to show the displacement of said rack tooth.

4. In an instrument of the character specitied, the combinationof means for supporting and rolling a gear to cause it to develop a art of its pitch circle into a straight line, a ever, resilient means for yieldingly holding the lever in a normal position, a pointed member connected with the lever, and adapted to mesh with the teeth of a gear on the supporting means in developing its pitch circ e into a straight line whereby any irregularities in the teeth cause the lever to move to indicate the presence of such irregularities.

5. In an instrument of the character specified, the combination of a support, means for developing a portion of the pitch circle of a gear supported on said support into a straight line, a member adapted to mesh with said gear, a lever pivotally mounted on said support and operatively connected to said member, means for holding said lever in a predetermined position, and an indicator engaging the other end of the lover to indicate any irregularities in the gear teeth actuated by the irregular teeth of the gear in displacing said lever.

6. In. an instrument for the purpose specified, the combination of a support, means for causing a gear supported on said support to develop a portion of its pitch circle into a straight line, a member adapted to engage between the teeth of the gear in making such movement, an indicating lever pivotally mounted on said support, means for yieldably holding said lever in a predetermined position, and an indicator engaging the other end of the indicating lever in a relation to multiply the movement from the point to the indicator stem contact whereby pull the an irregularities in the gear teeth cause the in icating lever to move and multiply the movement and communicate the same to the said indicator,

{7. In an-instrument for the purpose specified, the combination of indicating means for testing gear teeth for irregularities, and means for supporting a ear to be tested and causin it to roll and evelo a portion of one 0 its gear teeth circles mto a"straight line, the lattercomprising a slide .on which the gear is mounted rotatably, a reel concentric with the gear, and a band fixed to the reel periphery in registry with said circle of the gear and ada ted to-unwind as the slide is caused to trave and thereby constrain the gear to develop its said circle into a straight 8. In an instrument for the purpose speci-v fied, the combination .of indicating means for testing gear teeth for irregularities, and means for supporting a gear to be tested and developing a portion of one of its teeth circles-into a straight line, and comprising a slide, a reel rotatably mounted on the slide and arranged to be secured to the gear to be tested, a band carried on the reel, the band, the reel and the gear being arranged so that the reel periphery is in registry with the said *circle of the gear whereby movement of the slide causes the gear to develop itssaid circle into a straight line to permit the operation of the tooth testing means.

9. In an mstrumentjor the purpose specified, the combination of a slide, a reel mounted on the slide, a band fixed onto the reel and winding about the periphery of the reel, the band being arranged to be in substantial registry with one of the gear teeth circles of a gear to be tested adapted to be secured to and in registry with the said reel, and a spring for operating upon the reel to band taut about the reel periphery.

10. In an instrument for the; purpose specified, the combination of indicating means for testing gear teeth for irregularities, and

means for supportmg a gear and causing it to develop a portion of one of its gear teeth circles into a straight line, the latter comprising a slide adapted to gupport said gear, means for advancing the slide, a reel rotatably mounted upon the slide, a band encircling a portion of the periphery of the reel and having one end fixed, and a torsionalspring for taking up the slack of the band on the reel, the said band being in substantial registry with the said circle of said gear.

11. In apparatus of the character described, the combination of a support, a stud mounted thereon and supporting a roller and adapted to support a gear to be tested, a flexible member connected to said support and roller, means for moving ported on said stud to effect winding of and 'for translating and rotating a gear on sai a gear sup:

flexible, member on and oil said roller, a lever, lever operating connections between a toothofv the gear at one end of the'leve'r,

and means. operated bythe movement of said lever to indicate the inaccuracies of the gear teeth.

12. In apparatus of the character de-- .scribed, the combination of a su port for a gear permittmg a, gear su porte thereon to \be translated and rotate .a separate support associated w th said first mentioned support, a tooth engaging member mounted to move on said separate support in a direction parallel to the translatory movement of the gear, and indicating means operatively connected with said tooth engaging member to indicate the amount-of movement thereof resulting from inaccuracies inthe gear teeth.

In apparatus of the character described, the combination of a sup ort for a gear, an ind1cating means on em support, a tooth engaging member movably mounted on said sup ort and actuated by inaccuracies in the teet of a gear on said support, guide means permitting translator movement of the gear in a direction paral el to the direction of movement of said tooth engaging member and rotary movement about its axis, and operative connections between said tooth engaging member and said indicating means.

14. In apparatus of the class described,

the combination of a support for a gear to be tested, means associated with the support support, a separate support associated with sand first mentioned support, a gear tooth engagmg member on said separate sup ort mounted for movement in a straight me,

and indicating means operatively connected with said tooth engaging member to indicate the movement thereof resulting from inaccuracies in the gear tooth.

15. In a device of the class described, means for supporting a gear and causing it to roll and to develop a portion of its pitch circle in astraight line, a movable contact device supported and constrained to move in ioo a straight line, and means for holding said device in yieldable engagement with the face of a tooth of a gear on the support, whereby, when the gear tooth face is accurately formed, the gear will roll without appreciably moving the contact device, but,

when the gear tooth face is inaccurately 1 formed, the device will be moved, and means for indicating the movement of said device.

16. In apparatus of the class described, means for supporting a gear which is 'to be tested and causin it to roll on its pitch circle without slipping, a testing member pro-- vided with a surface having the shape and position relative to a gear on the supporting means of a rack tooth face in meshed engagement with a tooth of the rolling gear,

the testing member bein supported with ing the testing member, but, when the gear said surface held yieldab in engagement tooth is inaccurately formed. will move it with a tooth face of the supported gear and and means for indicating the movement 0 10 movable in a direction parallel tothe move said testing member.

5 ment of the center of the gear when rolling, In testimony whereof I aflix my signature.

whereby when the gear tooth is accurately formed, it'will roll without appreciably mov- JAMES A. MoINTOSI-L

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