Aug. 30, 1932. 3,5, OLSON 1,874,592

nos ennwmc ucnms Filed m. s. 1929 5 Sheets-Sheet 1 kg g j /ZZO (517/ 0Z5? Aug; 30, 1932' c. e, OLSON HOB GRINDING CHINE 5 SheetsSheet 2 :"L 6 w A D 1 Filed Juno '8. 1929 Aug. 30, 1932. c. a; OLSON 2 nos 9123mm IAGHINE I Filed June 8. 1925 5 Sheets-Sheet 3 Aug. 30, 1932. c. e. transom 1,374,592

nos enmnme lucamrz Filed Juno 8. 1929 5 Sheets-Sheet '5 Patented Aug. 30, 1932 UNITED STATES PATENT OFFICE CARL G. OLSON, OF CHICAGO, ILLINOIS, ASSIGNOR TO ILLINOIS TOOL WORKS, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS HOB GRINDING MACHINE Application filed June 8, 1929. Serial No. 369,502.

My present invention relates to improvements in methods of an apparatus for grinding hobs and it is one of the primary objects provision of methods and apparatus whereby grinding operations on a hob may be per formed without the ,necessity of using a plurality of machines and without the necessity of adjusting the grinding wheels for each operation and to this end I propose to successively position each of the various grinding wheels in substantially the same operating zone and upon the same mounting. More specifically, it is an object of my present invention to provide improved grinding wheel supporting means in association with a rotatable hob supporting spindle, said grinding wheel supporting means being such as to'enable grinding wheels used for successive and different grinding operations to be very accurately positioned with a minimum amount of eiiort and skill on the part of the operator.

Another object of my present invention is to provide in combination with a reciprocable grinding tool support, adjusting means of improved practical construction whereby the degree of reciprocating movement experienced by the grinding tool support may be accurately and quickly adjusted.

More specifically, my invention contemplates the provision of a stroke adjusting device in which a rack and pinion mechanism is employed to adjust the pivotal point of the link interposed between an actuating cam" and the cross slide or carriage.

These and numerous other objects and advantages will be more apparent when considered in connection with the accompanying drawings, wherein:

Figure 1 is a side elevational view shown partly in cross section of a hob grinding machine which is representative of a grinding machine by means of which my improved method of grinding hobs may be efficiently practiced;

Figure 2 is an end view of the machine as viewed from the right of Figure 1.

Figure 3 is a plan view of that portion ofthe machine which supports the hob and the grinding wheel;

Figure 4 is an enlarged fragmentary transverse sectional view of the machine taken substantially along the line 4-4 of Figure 1;

Figure 5 is a detailed plan sectional view taken substantially along the line 5-5 of Figure 4;

Figure 6 is an enlarged fragmentary elevational view disclosing the manner in which a grinding wheel may be employed to grind the outer relieved surfaces of the hob teeth;

Figure 7 is a fragmentary elevational view disclosing the manner in which a grinding wheel may be employed to grind spline hobs and the like; i

Figure 8 is an end view of the grinding fixture as viewed from the right of Figure 6;

Figure 9 is a horizontal fragmentary sectional view taken substantially along the line 99 of Figure 7;

Figures 10 and 11 are fragmentary plan I views disclosing the manner .in which grindv in wheels may be emplo ed for grinding at relieved side surfaces if the hob teeth; andv Figures 12 and 13 are front or side elevational views of the grinding wheels and supports shown in Figures 10 and 11, the hob 1n each instance being shown by dot and dash lines in order to disclose the parts which would otherwise be hidden.

Referring now to the drawings more in detail wherein like numerals have been employed to designate similar parts throughout the various figures, it will be observed that for the purpose of illustrating one practical application of my invention I have disclosed a hob grinding machine, the spindle driving mechanism of which simulates that disclossd in the Irwin Patent No. 1,70%,833, and my Patent No. 1,667,488. This driving mechanism includes an integral spindle 20, one extremity thereof being designed for supporting a hob 22 and. the other extremity thereof being formed so as to present a lead screw 24. The spindle 20 is mounted between a bearing 26 and a bearing 28, the latter bearing providing a nut in which the lead screw 24 rotates. The spindle 20 carries a gear 30 which meshes with an elongated pinion 32 .andthis pinion 32 is driven through the that therotation of the lead screw 24 within the hearing or nut 28 will cause the hob to be moved axially, the lead of the screw 24 being equal to the lead of the thread in the hob. It will be noted in Figures 1 and 3 that the hob is shown in its retracted position, that is,

in its extreme left position, Figure 1, and

this position is shown merely for the purpose of more clearly bringing to view the grinder unit which I have designated generally in Figures 1 to 3 inclusive by the numeral 42.

This grinder unit 42 comprises a grinding wheel 44 which is designed to grind the relieved-outer surfaces of the hob teeth, said grinder wheel being mounted upon a spindle 46 which is rotatable within a bearing 48. The outer end of the spindle 46 is provided with a pulley 50 which is connected in any suitable manner such as by means of a flexible belt 52 to a source of power supply (not shown). The bearing 48 is supported upon a base plate 54 which is centrally split at 56, Figure 8, so as to enable said base to be clamped upon a mounting 58. The base 54 is adapted to be clamped in position upon the mounting 58 by means of a suitable handle 60 which is mounted at the threaded ex- 'tremity of a clamping bolt 62 which completely traverses the base 54. In this connection it is to be noted that the base 54 is positioned upon the mounting 58 so as to accurately position the grinding wheel 44 with respect to the hob. In other words, the dovetailed connection between the mounting 58 and the base 54 serves to insure the accurate positioning of the grinding wheel with a minimum amount of effort on the part of an operator. The mounting 58 is carried by a slide 64, the movement of said slide being controlled by a hand wheel 66 which is carried by and secured to a screw 68. This slide 64 is in turn carried upon a slide 7 0 which is movable transversely of the machine by means of'an operating handle 72 carried by a screw 74,Figure 4. It will thus be apparent that the grinder unit 42 may be moved axially of the hob spindle by manipulating the handle wheel 66 and may be moved transversely of the spindle axis by rotating the handle 7 2. a The slide 7 0 is mounted upon a carriage 7 6 which is horizontally reciprocable upon a sub-base 7 8. Reciprocation is imparted to the carriage 7 6 through the agency of a cam 80, Figures 1, 2, 4 and 5, which is the numeral 88. A link which includes 2. pair of spaced arms 92 is pivotally secured at one extremity to the lower end of a depending arm 94 which is formed integral with or' otherwise secured to the carriage 76. The opposite extremity of the arms 92 receive a shaft 96, the portion of the shaft passing through the frame or yoke 86 supporting a collar 98. This collar 98 snugly fits within the longitudinal opening of the frame 86 and thus forms a connecting bearing between the frame 86 and the link 90. A coil spring 100 is interposed between one wall of the sub-frame 78 and a pin 102 secured to the carriage 76 and this coil spring serves to constantly urge the carriage to the right, Figure 4. From the foregoing it will be understood that during each rotation of the cam 80, the frame 86 will experience one complete oscillation and the carriage 76 a complete reciprocation. In order to vary the position of the shaft 96 within the frame so as to enable variations in the stroke imparted by the cam 80, I provide a rack and pinion device which includes a rack bar 104 and a companion pinion 106 which is secured to the shaft 96. Thus, rotation imparted to the pinion 106 will cause the shaft 96 t0 beraised or lowered with respect to the ,pivotal point 88, thereby varying the stroke imparted to the link 90. In order to facilitatethe rotation of the shaft 96 I provide a suitable hand wheel 108. To secure the shaft 96 in its various positions of adjustment I provide a ratchet 110 which is secured to the shaft 96 and the teeth of this ratchet are adapted to be engaged by a yield- ,able pawl or pin 112. This pin 112 is continuously urged into engagement with the teeth of the ratchet 110 by means of a suitable spring 114 mounted within a housing 116 which is carried by the link 90. The resiliency of the spring114 is such as to yield in response to manual manipulation of the hand wheel 108 and thus a convenient arrangement is provided for rendering the position of the shaft 96 adjustable at all times.

The inner end of the cam shaft 82 is connected with a drive shaft 116 through the agency of a click-clutch mechanism desig- 8 nated generally by the numeral 118. This clutch mechanism is similar in operating characteristics to that disclosed in the patent to Olsen et al. Reissue No. 16,590, and therefore a detailed explanation of the constituent parts will not be given at this time. It will suflice to say that this clutch mechanism includes a pair of ratchet members 120 and 122, the function thereof being to permit the member 120 to rotate backward without rotating the companion member or section 122. In this way the position of the cam is never disturbed when the hob is returned for a successive grinding operation. which rotates the clutch member 120, is driven from the shaft of the pinion 86 through the agency of a train of gears 124:, 126 and 128, Figure 1. The sub-frame 78 which supports the cam shaft and its associated mechanisms, rests upon a main frame 130 which houses the driving mechanism, etc., (not shown).

Thus far, the description of the grindingwheels has been limited to the specific type of wheel shown in Figure 6 and in Figures 1 to 3 inclusive. This grinding wheel 44 is particularly adapted for grinding the outer relieved surfaces of the hob teeth. In order to perform another grinding operation upon the hob teeth it is only necessary to impart a loosening twist to the handle 60 and slide the unit 42 from the mounting 58 and replace said unit by another unit as for example one of the units shown in Figures 10 and 11 which are designated generally by the numeral 42a. Each of these units 42a includes a grinding wheel 44a mounted upon a spindle 460, which is rotatable within a bearing 48a. A base 54a supports the bearing 48a and it will be apparent that one of the grinding Wheels will serve to grind one side of the hob teeth and the other wheel will grind the opposite side. Each of the bases 54a are adapted to be clamped in position upon the mounting 58ain the same manner as the base 54 by merely manipulating a hand wheel 60a.

In Figures 7 and 9 I have disclosed still another grinding unit which I have designa-ted generally by the numeral 42?). This grinding unit includes a grinding wheel 44?) which is of the type adapted for grinding spline hobs and the like. The wheel 4A?) is carried by a suitable spindle 46?) mounted within a bearing 48?). This bearing is mounted upon a base 54?) which is similar in construction to the base 5.4 already described. 'A suitable handle is provided to effect the clamping of the base 54?) upon the mounting 58.

From the foregoing it will be apparent that my invention enables a succession of grinding operations to be performed in a very convenient and economical manner. By practicing my improved method of grinding hobs, a grinding wheel, as for ex- The shaft 116 ample the grinding wheel 44, is supported ina predetermined position and by suitable rotation of the hob and the wheel, the outer surfaces of the hob teeth are relieved. Upon the completion of this grinding operation this grinding wheel is removed and a grinding wheel for performing a different grinding operation is supported similarly to the first mentioned wheel without disturbing the position of the hob, and then this second wheel is operatively associated for grinding the hob teeth as for example the relieved sides of the teeth by the use of the grinding wheels 44a. Obviously, various types of wheels may be employed for producing diiferent grinding operations upon the teeth. The standard mounting 58 serves as a common support for all of the grinding units, the grinding wheels being thus successively positioned in substantially the same grinding zone for each operation. Each of the grinding wheels and their respective spindles must be positioned at the proper elevation in order to properly function and this proper vertical positioning of the wheels is accomplished by aving the unit so arranged that the distance between the spindle axis and the top of the mounting 58 is in accordance with the design of the hob to be ground. It will be apparent that by successively positioning grinding wheels in the same zone of action in the manner described, a minimum amount of adjustment of the grinding wheel is necessitated. In some of the methods which have heretofore been practiced in performing the 1913 various grinding operations to which a hob must necessarily be subjected, numerous adjustments have been made to properly position the grinding wheel and these adjustments have not only necessitatedv consider- 105 able skill on the part of the operator but also have required the expenditure of a considerable amount of time. By using my improved apparatus in practicing the above described method, I am able to reduce the necessity for adjusting the position of the grinding wheels to a minimum by reason of the simplicity in successively mounting said wheels in operative relation with respect to the hob teeth. The described means for ad- 5 justing the stroke of the transverse carriage 76 also presents a simple and economical construction. By merely imparting rotation to the hand wheel 108 the axis of the shaft 96 may be raised or lowered with respect to the pivotal point 88 so as to adjustably control the degree of relief which is imparted to the hob teeth during the grinding operations. The described apparatus presents a very compact, efliciently operable machine which may be economically manufactured.

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

1. The method of grinding hobs having a spiral series of relieved teeth which includes the steps of supporting a grinding wheel in a predetermined position, rotating the grinding wheel and the hob to eifect a certain grinding operation on one of the surfaces of the hob teeth, removing said grinding wheel upon the completion of said grinding operation, maintaining the position of the hob and similarly supporting another grinding wheel for grinding a second surface of the hob teeth, effecting grinding contact between the hob and the second mentioned wheel, replacing said second mentioned wheel with a third wheel, and efi'ecting grinding contact of said Wheel with a third surface portion. a

2. In a machine of the class described, a

rotary work supporting spindle, a tool hold-' to the axis of oscillation of the oscillatory means.

3. In a machine of the class described, a rotary work supporting spindle, a tool holder for supporting a tool in operative position with respect to said work, and means for causing relative bodily movement between the work and the tool radially of the work axis, said means including a cam and an oscillatory means for imparting movement to one of the aforementioned parts, said oscillatory means having a connecting member and a rack and pinion mechanism for effecting the adjustment of said connecting member with respect to the axis of the oscillatory means whereby movements imparted in response to the actuation of the cam may be ad- 1 justably varied.

4. In a machine of the class described, a roe tary work supporting spindle, a tool holder for supporting a tool in operative position with respect to the spindle, said tool holder being reciprocable to effect the movement of the tool radially of the work carried by the spindle, and means for reciprocating said tool holder including a cam, an oscillatory means engaging said cam, and means for operatively connecting said oscillatory means with the work holder, said oscillatory means having a connecting member mounted therein which is adapted to be adjustably positioned with respect to the axis of said oscillatory means whereby variations in the stroke imparted to the tool holder in response to the actuation of the cam may be adjustably varied.

5. In a machine of the class described, a rotary work supporting spindle, a. tool holder for supporting a tool in operative position with respect to the work, and means for imparting relative bodily movement between the work and the tool including a rotary cam, and an oscillatory frame engaging said cam for imparting movement to one of the aforementioned parts in response to the rotation of the cam, a connecting member within said frame, and a rackand pinion mechanism associated with said frame for adjusting the position of said connecting member with respect to the axis of oscillation of the frame.

6. In a machine of the class described, a rotary work supporting spindle, a tool holder for supporting a tool in operative position with respect to the work, and means for imparting relative bodily movement between the work and the tool including a rotary cam, an oscillatory frame engaging said cam for imparting movement to one of the aforementioned parts in response to the rotation of the cam, a connecting member within said frame, a rack and pinion mechanism associated with said frame for adjusting the position of said connecting member with respect to the axis of oscillation of the frame, and means for locking the rack and pinion mechanism in various positions of adjustment.

7. In a machine of the class described, a rotary work supporting spindle, a tool holder for supporting a tool in operative position with respect to the work, and means for imparting relative bodily movement between the. work and the tool including a rotary cam, an oscillatory frame engaging said cam for imparting movement to one of the aforementioned parts in response to the rotation of the cam, a connecting member within said frame, a rack and pinion mechanism associated with said frame for adjusting the position of said connecting member with respect to the axis of oscillation of the frame, and a pawl' and ratchet mechanism securing said rack and pinion mechanism in various positions of adjust'ment.

8. In a hob grinding machine of the class described, a rotary work supporting spindle, means for effecting longitudinal movement of the spindle, a tool holder for supporting a grinding wheel in operative position with respect to the work supported by the'spindle during the rotary and longitudinal movement thereof, a machine frame for slidably supporting the grinding wheel holder, a rotary cam, a pivoted member engaging said cam, means connecting said pivoted means with the grinding wheel holder, and a rack and pinion mechanism for varying the position of said connecting means to adjustably control the relieving action of the supported grinding wheel.

In witness whereof, I have hereunto subscribed my name.

I CARL o. OLSON.