US2433717A

US2433717A - Shaft grinding machine and the like

Info

Publication number: US2433717A
Application number: US583507A
Authority: US
Inventors: Sven A Stolberg
Original assignee: RUSSELL ELECTRIC Co
Current assignee: RUSSELL ELECTRIC Co
Priority date: 1945-03-19
Filing date: 1945-03-19
Publication date: 1947-12-30
Anticipated expiration: 1964-12-30

Description

s; A. STOLBERG SHAFT GRINDING MACHINE AND THE LIKE Filed March 19, 1945 11 Sheets-Sheet 1 INVENTOR! svem-hs'lulber Dec. 30, 1947. a STOLBERG 2,433,717

SHAFT GRINDING MACHINE AND THE LIKE Filed March 1 9, 1945 1 1 Sheets-Sheet 2 INVENTOR. Sven-Afii'olber Dec. 30, 1947. s. A. STOLBERG SHAFT GRINDING MACHINE AND THE LIKE Filed March 19, 1945 11 Sheets-Sheet S INVENTOR. I Sven-ASTMbers,

Dec, 30, 1947. s. A. STOLBERG 2,433,717

SHAFT GRINDING MACHINE AND THE LIKE Filed March 19, 1945 ll Sheets-Sheet 4 mmvron. SvenA. Si-fiber .31 l i lllil. m

m E in 2 1 $1 a a Dec. 30, 1947. s. A. STOLBERG SHAFT GRINDING MACHINE AND THE LIKE Filed March 19, 1945 11 Sheets-Sheet 5 w: w Wmwmw. w I mw y w: 7 T v m: m I M a v1 llll ll {1| T v e nn W3 QV I I w: W an/w 8. .2 s \A +6 8 v a I Ms i 6 I 3 m r4 W I. wyfivnwr 6 1; NM; Q v. MIMI m: 2. 375. L

Dec. 30, 1947. s. A. STOLBERG SHAFT GRINDING MAQHINE AND THE LIKE I 11 Sheets-Sheet 7 Fiied March 19, 1945 2 Y W\\\\\ IL I1 mn v Ni SHAFT GRINDING MACHINE AND THE LIKE Filed March 19, 1945 I ll Sheets-Sheet 8 Dec. 30, 1947.

s. A. STOLBERQ SHAFT GRINDING MACHINE AND THE LIKE Filed March 19, 1945 ll Sheets-Sheet 9 Q bw i o #tosnw p0 LPEEQD om w 5 INVENTOR.

Dec. 30, 1947. s. A. STOLBERG SHAFT GRINDING MACHINE AND THE LIKE ll Sheets-Sheet 1O INVENTOR fiven $.21 B Q Filed March 19, 1945 1947- s. A. STOLBERG I SHAFT GRINDING MACHINE AND THE LIKE Filed March 19, 1945 v 11 Sheets-Sheet ll Patented Dec. 30, 1947 SHAFT GRINDING MACHINE AND THE LIKE Sven A. Stolberg,

Chicago,

Ill., assignor to Russell Electric Company, Chicago, 111., a corporation of Illinois Application March 19, 1945, Serial No. 583,507

Claims.

This invention relates to improvements in shaft grinding machines and the like. In particular it has to do with improvements in centerless grinding machines, that is, grinding machines in which the shaft or other Work is supported in grinding position by engagement with a surface which engages the surface of the shaft or other work itself, as distinguished from machines in which the work is supported by end centering supports. Certain features of the present disclosures, however, are not limited to use in centerless grinders, as will appear from a detailed examination of the said disclosures. It is also an object of the present invention toprovide a grinder which is Well adapted to grinding the shafts of rotors and similar work, but as will appear hereinafter the features of the present invention are not limited to such uses.

An object of the invention is to provide a grinder which is so designed and constructed that it is capable of securing very accurate grinding results; being capable of grinding the shafts of the rotors or other work to very close tolerances. This is a very important'object, since very slight variations from prescribed shaft sizes will result in poorly operating rotors, especially when said rotors operate at high rotative rates. In this connection, it is an object of the invention to provide a grinder which is well adapted to accurate grinding of relatively small shafts to very close tolerances, thus adapting the grinder to use in finishing the shafts of small rotors. In this connection it is noted that such small shafts as are used in these small rotors cannot well be supported by center supports during the grinding operations, and for this additional reason it is desirable to effect the grinding operations by use of centerless grinders. The present invention relates to improvements in such centerless grinders for small shafts or other work.

One feature of the present invention is to provide a centerless grinder of such construction that when once the grinder and the grinding wheel have been set up for work each shaft or other piece of work will be brought to exactly the correct position with respect to the grinding wheel and against the peripheral grinding surface of such wheel to ensure correct and accurate grinding finish of the shaft to exact size. This result is secured by direct application of the work to the eripheral grinding face of the wheel with movement of the work radially of such grinding wheel, and Without the need of endwise movement of the Work itself. In other words, no end wise or longitudinal movement of the shaft or other work element is required during the grinding and finishing operations, all said operations being performed by a single movement of the work towards the axis of wheel rotation. The exact finish size of the work is then determined by the limit of such inward movement of the work towards the axis of wheel rotation.

Since the exact finish size of the Work is determined by the limit of such movement towards the axis of wheel rotation it follows that for exactness and uniformity of performance the grinding machine must be so designed and constructed that each and every piece of work will be brought finally to the same exact distance or radius from the axis of wheel rotation; and it is an object of the present invention to make provision for attaining this result with a high degree of accuracy. In this connection it is here noted that the presently disclosed embodiment of my invention includes a step-by-step rotatable wheel or carrier which brings the rotors or other units of work successively into grinding position with respect to the grinding wheel. It is an important object of the present invention to make provision in this carrier for exact uniformity of carriage of the successive rotors or other work units, so that they will all be brought to grinding range and position at exactly the same position with respect to the grinding wheel axis. Any non-uniformity in the final grinding positions or ranges of the various units of work would result in non-uniformity of finish sizes of the rotor shafts; but by use of one feature of my present invention I am able to so build the carrier, and to so finish its shaft supporting surfaces that exactness of position of said surfaces will be assured to a uniformity which is required by the degree of tolerances permitted between finish sizes of the various work units being ground.

In connection with the foregoing feature, I so build the carrier wheel that its peripheral portion is provided with shaft supporting surfaces for the successive shafts or units of work, said supporting surfaces being of hard metal, and the carrier design being such that all said surfaces may be initially ground to a high degree of exactness, and on the same radius of the carrier wheel itself.

The work carrier wheel advances from position to position by a step-by-step movement, bringing a fresh unit of work into finishing position at completion of each step of such movement. The grinding wheel remains supported on'a fixed axis of rotation during these step-by-step advancements. Each rotor shaft or other unit of work is originally of over-size and must be ground portion of the carrier wheel.

down to the exact prescribed finish size. It is desirable to so arrange the grinding operations that the initial grinding action will be in the nature succeeding unit of Work towards the axis of the.

grinding wheel should be relatively fast during the roughing operation, followed by a' greatly reduced rate of movement towards the axis of the grinding wheel, and terminating witha complete rest of the work at the final or finish position;

By such a sequence of rates of movement the several stages of grinding will beproperly related to each other to ensure a finish of the work to exact size, and with extremely close toierances. The machine "hereinafter disclosed is specially adapted to secure these results.

In connection with the foregoing objective, and in connection with the feature ofa stepbystep advancement of the units of work, it is noted that when using a carrierwheel of relatively large size or diameter, the final rest positions ofsaid carrier wheel will depend on the form and accuracy of performance of the step-by-step mechanism whereby said carrier is advanced. The exactness of such rest positions, and their variations from a specified rest point, will depend largely on the accuracy or tolerance of the-stepby-step device, and when using a carrier of relatively large size there may be slight departuresof the rest positions of the work units from such specified point. However, it is an object of the present invention to so design and construct the grinder that relatively substantial variationsof rest positions of the successive units of work will not materially vary the finish size to which the said units of work are ground, due to the relationship which I have established between the carrier with its step-by-step stop positions, and in the manner in which the grinding wheel performs its work. Thus I have provided a grinder wherein the desired exactness of finish grinding will be secured even with slight variations "of stop positions of the units of work.

Since the carrier wheel comes to rest for an interval during the finishing of the grinding operation, it is desirable to provide for holding the carrier wheel in such rest position for each unit of work. To this end I have provided a brake device which e'ifectively holds the carrier wheel stationary during this rest interval; and I have also provided for accurate adjustment of the braking action thereof so that smooth operation of the carrier wheel will be ensured at all times. In this connection I have also provided a positive hold-back device to ensure against accidental reverse movement of the carrierwheel in case of emergency.

It is a further object of the present invention to provide for simultaneous grinding of both ends of the shafts of rotors and like units of work. In such operation the body portion of the rotor which is larger size than the projecting shaft end portions must be accommodated without interfering with the grinding of said shaftaends. I have made provision for such accommodation of the body portions of the rotors inthe peripheral In this sam connection, I have also made provision for accurately spacing the individual rotors and their shafts endwise of said rotor shafts, so that exactly the correct positioning of each rotor and its shaft ends will be ensured on the carrier wheel during the grinding operation. Specifically, also, I have made provision for substituting different end spacer for the rotor shaft ends to thereby make provision for accommodation of various lengths and designs of rotors and their shafts.

I have also made provision for feeding the successive rotor or other work units into place on the carrier wheel with the step-by-step advancements of said wheel, so that the supplying of units of work will proceed automatically and continuously during the operations of the grinder. In this connection, I have also made provision'for bringing each succeeding unit of work into place adjacent to the carrier wheel periphery, and for ensuring that such unit of work will then betaken correctly into its assigned holder in the carrier wheel for proper holding during the succeeding grinding operation. Likewise, I have made provision for automatically discharging the successive finished and ground units of work from the carrier wheel to a suitable receptacle, and for at the same time ensuring correct release of each finished unit of work from the carrier wheel.

I hav also made provision for securely holding each unit of work in its assigned place on the carrier wheel during the movements of said Wheel, step-by-step from entry to discharge of such unit into and from the carrier Wheel. This holding means, in the disclosure hereinafter made, is in the form of a belt which travels over the successive units of work on the carrier wheel. I have also made provision for retaining said belt at all times under the desired amount of tension, which tension is made adjustable from a convenient position, either during operation ofthe carrier wheel, or while said wheel is idle.

I have also made provision for rotating the several units of work on their respective axes during the grinding operations. This is necessary in order that each shaft element will be .uniformly ground around its entire peripheral surface, and to avoid any eccentricity of such ground shaft element when finished. In this connection, I have so arranged the parts that a number of complete rotations of such rotor shaft or unit of work will occur during the finishing operation, thus improving the finishing accuracy of the operation.

Specifically, I have also availed myself of the presence of the aforementioned holding belt for also securing the rotations of the rotors or units of work during the grinding and finishing operations, thus simplifying and improving the design and construction of the complete machine.

In the drawings:

Figure 1 shows a'plan view of a grinding machine embodying the'features of my present invention, several rotors or workunits being in place on the carrier wheel;

Figure 2 shows a frontelevation, corresponding to Fig. 1;

Figure 3 shows a right-hand end elevation corresponding to Figs. 1 and 2; on. enlarged scale as compared to Figs. 1 and 2;

Figure 4 shows'a cross-section through the machine taken on the lines4-4 of Figs. 1, 2 and 6, looking in the directions of the arrows, and it shows in particular the right-hand face of the carrier wheel and adjacent parts, includin the work feeder and the work receiver, eto.; Fig. 4 being on enlarged scale as compared toFigs. 1 and 2.;

Figure 5 shows a cross-section through the machine taken on the line 5-5 of Figs. 1, 2 and 6, looking in the directions of the arrows, and it shows in particular the left-hand face of the carrier wheel and adjacent parts, similar to the ShOWiIlg of Fig. 4, and Fig. 5 is also on enlarged scale as compared to Figs. 1 and 2;

Figure 6 shows a longitudinal section through the central portion of the machine, and especially through the carrier wheel element, and bearings therefor, etc., being a section on the lines 66 of Figs. 1, 3, 4 and 5, looking in the directions of the arrows; Fig. 6 being on enlarged scale as compared to Figs. 1 and 2;

Figure '7 shows a cross-section on the lines l---'! of Figs. 1 and 2, looking in the directions of the arrows, and on enlarged scale as compared to said figures;

Figure 8 shows diagrammatically the relationship of the carrier wheel, the grinding wheel, and units of work being brought into grinding position, and it shows the manner in which the diameter of a unit of work must reduce from any initial diameter to a specified finish diameter during the step-by-step movement of the carrier wheel to the final grinding and finishing position;

Figure 9 shows by a series of curves the relative relationship of the several movements with respect to each other and with respect to time and velocity, in the type of grinder herein disclosed; 7

Figure 10 shows an edge view of the carrier wheel itself, on enlarged scale as compared to previous views;

Figure 11 shows a side elevation corresponding to Figure 10, the shaft end retainers for the work units being removed from both Figures 10 and 11 to simply said figures;

Figure 12 shows a detail elevation of one of the carrier wheel shaft bearings, whereby said shaft is journaled and also is gripped to effect a braking action on the carrier wheel rotation; this figure being an enlarged scale as compared to Figures 1, 2, 3 and 6;

Figure 13 shows a longitudinal section corresponding to Figure 12, being taken on the line Iii-l3 of Figure 14, looking in the direction of the arrows;

Figure 14 shows an end view corresponding to Figures 12 and 13, looking at the right hand end of the element of said figures;

Figures 15, 16, 17, 18 and 19 are detail views of the fixture used for supporting the radial inserts which act as stops to set the rotor shafts at the correct positions on the carrier wheel, and to ensure that said rotor shafts will be correctly placed when the carrier wheel comes to rest, to ensure correct grinding of the rotor shaft supported against said radial inserts; Figures 15, 16, 17, 18 and 19 being on enlarged scale as compared to Figures 1 and 2; and

Figures 20, 21, 22, 23 and 24 are detail views of the form of rotor shaft end retainer used on the carrier wheel for the left-hand ends of the rotor shafts when viewed as in Figures 1 and '2, these retainers being of spring characteristic; and Figures 20, 21, 22, 23 and 24 being on enlarged scale as compared to Figures 1 and 2.

In order that the fundamental principles governing the movement of the units of work to finishing position herein disclosed, reference may first be had to Figs. 4, 5, 6, 10 and 11, wherein the construction of the carrier wheel is shown. This wheel includes a body portion 30, keyed or otherwise drivingly carried by the cross shaft 3|. Said wheel is designed to accommodate rotors or other units of work of a general size limit for which the grinder is intended; and to this end said carrierwheel is provided with the circumferential groove or depression 32 which is of width and depth to accommodate the body portions of the units of work. In Figs. 4 and 5 several such rotors are shown in place on the carrier wheel, each being designated by the numeral 33, and the several rotors being individually identified by the suffixes a, b, c, d and 6, respectively. Furthermore, rotors which have not yet been taken into the carrier wheel are designated as 33, with the suffixes .x, and those rotors which have been ground or worked are designated as 33 with the sufiixes g. Each rotor has the rotor shaft 34 whose projecting end portions are to be ground to a predetermined exact and uniform size.

These rotors when in place on the carrier wheel have their projecting ends supported by the

wheel side flanges

35 and 36 at the sides of the depression 32, the said depression being of sufficient depth to fully accommodate the body portions of the rotors with the rotor shafts supported by said flanges as well shown in Figs. 4 and 5. The grinding wheel is shown at 31 in Fig. 4 (and it is also shown in Fig. 8 which will be presently considered in detail). This grinding wheel is preferably of relatively large diameter, and the grinding and finishing operations on the rotor shafts are performed by the peripheral face 38 of this wheel 31. For this purpose said peripheral face is made of width sufficient to meet the requirements of the length of shaft to be ground and finished, and said face is dressed. to an exact surface lying in a cylinder parallel to the axis of grinding wheel rotation. Means for so dressing said grinding wheel are provided on the grinder of the present disclosure, as will presently appear.

An examination of Figs. 4 and 8 will show that the peripheral face of the grinding wheel is set at a-definite clearance from the

edge portions

35 and 35 of the carrier wheel. Consequently, if the rotor shafts are supported against said

edge portions

35 and 36 during the grinding operation the rotor shaft will be ground and finished to a diameter equal to this clearance, if, during the advancement of the carrier wheel a given rotor with its shaft is advanced past the position where the grinding wheel comes closest to these edge portions. Furthermore, the position of the rotor 33 in Figs. 4 and 5 is that position at which each shaft is finish ground, since advancement of the carrier wheel past that position results in carrying the rotor shaft again away from the peripheral grinding edge surface of the grinding wheel.

Furthermore, the rotors are themselves rotated during the grinding contact with the grinding wheel, preferably in the directions shown by the arrows in Fig. 4, the direction of rotation of the grinding wheel also being therein indicated. Thus, each shaft is ground and finished uniformly around its entire circumferance. This action will be more fully considered hereinafter in connection with a discussion of Figs. 8 and 9.

The carrier wheel is advanced in the direction of the large arrow 39 in Figs. 4 and 5. This advancement is preferably effected with a step-bystep movement, but evidently other types of advancement might be substituted, such as continuous rotation of the carrier Wheel at the propby the radial line 43 in said figure.

* an'segvrv :er angular speed. 'Since, "however, step-by-step advancement is particularly disclosed herein I shall refer to the same, but in so doing I wish 'it understood that I do not intend to limit myself to such operation, nor .to the means to se- :cure such operation, except as I may do so in the claims to follow.

When using a step-by-step operation, the adancements should be so effected that each com- .plete pause occurs with the carrier wheel in such position that the shaft then being worked lies directly in the line ill which connects the centers of rotation of the carrier wheel and the grinding wheel (See Fig. 8.) This is the position of minimum clearance between the

edge portions

35 and 36 of the carrier wheel and the peripheral grinding surface of the grinding wheel. In that position the

rotors

33 and 33* have .not yet reached grinding position, and the

rotors

33 and 33 have been worked and have passed beyond the grinding position. n the next stepicy-step advancement all rotors will advance one position from that shown in Figs. 4 and 5, the rotor 33 being discharged and a new rotor being added to the carrier wheel at the supply position presently to be described. Since each shaft of a rotor is over-size prior to reaching the grinding position by a generally pre-selected amount, and since each shaft is then to be ground to exactsize and finished at the finish position of the rotor 33, this action deserves careful consideration in order that the functions of the machine as an entirety may be better understood. For this purpose reference may nowbe had to Figs. 8 and 9.

In Fig. 8 I have shown schematically the carrier wheel 35 and the grinding wheel 31, and their respective axes of rotation, 3i and M. It is also assumed that the carrier wheel is advanced stepby-step through an angle of 45 degrees at each advancement, as this is a convenient amount of advancement and is the amount provided for in the presently shOV/n design. Then the position of the rotor 33* is shown by the radial line 42 in Fig. 8, and the position of the rotor 33 is shown (Note: the line 43 coincides with the line it drawn between the two centers of rotation, for the carrier wheel and the grinding wheel, respectively). It will also be noted that the maximum diameter of rotor shaft which could possibly be accommodated at the position of the radial line 42 is shown by the circle l i, being in contact with the carrier wheel flange or edge and with the grinding urface of the grinding wheel. As the carrier wheel is then advanced from the radial line position e2 to the radial line position 43 the diameter of that rotor shaft would have to be reduced finally to the clearance distance between the carrier wheel edge and the grinding wheel surface. Such reduction would have to be effected by the grinding action. Man'ifestly, such an amount of shaft reduction is greatly in excess of actual requirements, but the principle thus brought into play can be well illustrated by considering this maximum condition as well as conditions of more practical amounts.

In advancing the carrier wheel from the radial position 2 to the radial position 43 said carrier wheel and the sup-ported rotors must be acce erated from a position of rest (at the position of the line 32) to a maximum angular velocity condition; and then said parts must be decelerated back to zero velocity or rest at the finish position of the line 43. A simple means of advancementof the carrier wheel, step-by-step 'is oneinclu'ding :arocking'pawlacting periodically ion a ratchet wheel connected to the carrier wheel; and since that form of structure is shown in detail herein I shall consider itmore in detail in considering the accelerations and decelerations lust referred to.

I have also assumed that the pawl movements are such, in relation to the ratchet wheel, that a substantially sinusoidal movement of the carrier wheel is effected, from a rest position to a maximum angular velocity, and back to rest at the finish position. In Figure 8 I have shown a number of successive radial lines between the lines it and 6'3,- representing successive angu-larly moved positions. of the carrier wheel between the two rest positions. I have alsoin that figure shown the sizes of shafts which can be -accom'- modated between the edge of the carrier wheel andthe grinding surfaceof the grinding wheel for such several radial linepositions. It is noted, of course, that these shaft sizes successively diminish as the carrier wheel is advanced.

In Figure 9 I haveshown by the curve 55 the angular advancement in degrees with time elapsed during argiven advancing operation; and it is noted that this curverises slowly at first, then rapidly, and then again reduces in speed or angular advancement to the final rest position 55. The curved? shows angular rate of advancemeht .in comparison to degrees of angular travel; and it is noted that, since the advancement is substantially sinusoidal in form, this curve rises to a maximum at the point 48 where one-half of the advancement has been accomplished, and then falls to zero speed at the point where the'advancement has been concluded.

I have shown, by the curve 50 the variation of shaft diameter or grinding finish which can be accommodated between the edge of the carrier wheel and the grinding surface, for the successive angular positions represented "by the radial lines in Fig. 8. This curve diminishes in height from the initial position 5| rapidly at first, and then more slowly, to the final 'or finish position 52, at which final position the'shaft' must be of a diameter equal to the clearance between the edge of the carrier wheel and the grinding surface.

From the curves ii and 50 I have been able to plot the curve 53 which represents the variation of angular velocity of carrier wheel advancement with diameter which can be accommodated between the carrier wheel edge and the grinding surface; and it is noted that this curve rises from the position 5d where the advancing action commences, to the position 55 where the rate of change is a maximum, and then falls very rapidly to zero again at the position 56 where the shaft diameter is equalto the clearance between the carrier wheel edge and the grinding surface. The rapid falling of this line or curve in the portion 5? between

the'positions

55 and 55 is significant, and merits further consideration herein.

Manifestly' for practical purposes the amount of reduction of shaft diameter by the grinding operation is quite small, probably only a few thousandths of an inch for relatively small shafts. Therefore the position of initial engagement of the work with the grinding surface does not take place until the advancement has proceeded to some point along the portion 57 of this curve and in fact, probably some point near the lower end of such portion 5! and only slightly above the zero line and above the finish point 56. In that range it is seen thatthe angularv efiected by a considerable angular movement. of.

the carrier wheel, and at the same time, that movement of the carrier wheel is being slowly effected, so that the last stages of .reduction of shaft diameter and finish are being effected under the most advantageous conditions.

It is also to be noted that by increase of diameter of thergr'inding Wheel the above benefits are further accentuated, since thereby the rate of reduction of shaft diameter in the last,

stages is less than is the case. with a larger diameter of grinding wheel. The ideal condition would be one including a grinding'wheel of infinite diameter, that is, a straight grinding surface; and in Fig. 8 I have shown such an ideal grinding surface by the straight line. 58 In Fig. 9 I have shown by dotted curves 59 and 60 the conditions corresponding to the

curves

50 and 53, respectively, but for the, condition of a grinding wheel of infinite diameter; and it will be seen that the slope of thedownwardly extending portion Gl of the curve 60 is even greater than the portion 57 of the curve 53. I

It is evident that the uniform accuracy of successive grinding. operations depends onthe fundamental condition that the clearance between the peripheral edges of the carrier wheel and the grinding surface shall be exactly the same for all successive positions of the carrier wheel. In other words, as each fresh unit of work comes finally to the position of the line 43 (see Fig. 8), the clearance between the supporting edgeof the carrier wheel and the grinding surface must be exactly the same as the clearances of previous work supporting points of said carrier wheel from the same grinding surface. Any departure from that condition will be reflected in non-uniformity of finish sizes of different units of work, and non-dependability of the accuracy of the machine as a whole. To ensure against such possibility of non-uniformity I have made provision in the following manner: 1 t

The work supporting edge portions of the carrier wheel are provided, at each work supporting position of said Wheel, with the hard metal (such as tool steel) inserts 58 and 59. These are set into suitable recesses provided in the wheel edges, and are held therein securely as by brazing or otherwise. It is here noted that the carrier wheel is finally provided with suitable positioning lugs or retainers at the sides of said wheel in position to position each rotor or other unit of worklaterally of the carrier wheel, which retainers will be hereinafter described;' but these are secured to the side faces of the carrierwheel after the

inserts

53 and 59 have been set into place and after said inserts have been finished. Such finishing comprises accurate grinding of the entire peripheral edge portions of the carrier Wheel after these inserts have been set and secured in place, so that said inserts then are exactly ground to'accurate centering with respect to the axis of carrier wheel rotation; and so that all these inserts then have exactly the same radius measured from the axis of rotation of said carrier wheel. Since these inserts afterwards perform the function of supporting and exactly placing the units of work during the grinding operations it follows that with this arrangement there is full assurance that all units of work will be so supported at exactly the same radius from the axis of carrier wheel rotation, and therefore the clearances all said inserts measured from the grinding surface of the grinding wheel on the line will be exactly the same. Thus all units of work, such as rotor shafts, will be ground to exactiy the same size of finish.

It is here noted that by following the procedure of grinding these inserts to exactness prior to attachment of the side retainers to the carrier wheel it is possible to efiect such grinding operation over the full circumferential surfaces of said inserts and clear out to the side edges of the carrier wheel itself. The work supporting surfaces are designated 60 and iii for convenience.

In order to ensure that each unit of work will be brought to the position of the line 43 and directly in alignment with the plane passing through the axes of rotation of both the carrier wheel and the grinding wheel, and to ensure that each unit of work will be retained in such alignment during the rest interval of the carrier Wheel and during the finishing operation, I have provided a radial, or substantially radial surface 62 on each edge of the carrier wheel directly behind the work position. These surfaces 62 for each supporting position are in the form of inserts of hard metal (such as tool steel) set into or against bracket plates 63 secured to the side faces of the carrier wheel itself. These bracket plates have the overhanging arms 65 which overlie the peripheral or edge portion of the carrier wheel, so as to span the entire width of the edge portion of such carrier wheel; and the inserts or hard metal elements 62 are secured thereto in convenient manner, as by brazing or otherwise. These inserts have their radial faces finished, preferably ground. It is noted that when the unit of work such as the rotor shaft is in place it bears against these surfaces 62 which thus prevent such rotor shaft from rolling peripherally over the edges of the carrier wheel, thus also ensuring proper placement of the rotor shaft during the grinding and finishing operation.

Now examination of Figure 8 in particular will disclose that any slight departure of a unit of work from the exact position of the line 33 during the finishing operation will result in a slight departure of the finish size from that prescribed, since the curving surfaces of both the carrier wheel and the grinding surface both depart from each other as the position of the line 43 is vacated. However, due to the relatively large sizes of both the carrier wheel and the grinding wheel, and due also to the fact that such departure from exactness is proportionate to the change of the co-sine of the angle 1 of departure from exact alignment, it follows that slight variations from exact alignment will result in only extremely minute variations from the exact prescribed finish size of the unit of work, and in order to cause any variation which would be beyond the permissible tolerances of finish size the departure from exact alignment would have to be quite considerable.

Due to the foregoing circumstance it is found permissible to finish' the faces BZ'of the inserts prior. to attachment of said brackets63 to the.

assay-1r:

variations of positioning of the successivebrack ets from exactness will result. in variations of finish position of the successive units of work of such slight amount asto cause variations in finish sizes of the grinding operations well within the limits of tolerance prescribed in usual practice. These brackets 83: are secured to the side faces of thecarrier wheel in convenient manner, as by means. of screws 65. It is noted that it is desirable to ensure that the surfaces 62 shall be parallel tothe axis of thecarrier wheel. Such result canbe secured with suincient accuracy by grinding said surfaces prior to attachment of thebrackets to the carrier wheel itself. These brackets are preferably set into recesses 58 formed in the side faces of the carrier wheel as well shown in Figures and 11, thus; further ensuring correct placement of said brackets and the surfaces 62.

Reference to Figures 1, 4, 5 and 6 shows the presence of retainers 61. at one side face of the carrier wheel, and retainers 58 at the other sideface ofsaid' wheel, and at each work unit supporting; position. One of the retainers 68 is shown in detail in Figures 20, 21, 22, 23 and 24. The retainers ii]: may bedesignated as spacers, and the retainers 58* as holders, since each of the retainers 61 serves to accurately space the rotor shaft or other unit of work transversely of the carrier wheel, whereas the retainer 68 is of spring form and serves topress such shaft or unit of work against the retainer 6'? under spring pressure to ensure correct engagement of the endv of the shaft with the retainer 57, and this to ensure correct spacing of the rotor laterally on the carrier wheel.

Each of theretainers 6 lconveniently' takes the form of a substantially rectangular plate placed in face contact with the bracket 53, and conveniently held in place by the same screws 65 which secure said bracket in place; and said plate of the retainer t? is provided with a radially'extend ing lug 69 which projects out far enough to overlie the shaft end of the rotor shaft; said lug being preferably recessed as shown at in Figures 1 and 6, to receive the rotor shaft end.

One of the retainers 68 is shown in detail in Figures to 24, inclusive. formed from sheet metal, being provided with a plate portion H adapted to lie fiat against thebracket 63 at that location, and conveniently held in position by the samev screws 65 which secure said bracket in place. This sheet metal blank is then formed outwardly at right angles to provide the outwardly extending flange portion l2 which reaches outwardly a distance sufiicient to meet the requirements of the rotor shaft length being handled. Said outwardly extending portion is then further treated to provide the edge lug 13 which extends more or less radially of the carrier wheel, and reaches outwardly far enough to properly engage the end of the rotor shaft. It is noted from examination of Figure 24 that the portion 12 is cut back to provide the notch M adjacent to said lug portion 13 at the leading edge of said lug portion, so that said leading edge portion of said lug is supported or attached to the portion 12 with 'a spring like function, permitting said lug to spring outwardly slightly during engagement with the shaft end, and thus to retain said shaft firmly gripped against the nonspring retainer 61 at the opposite sideof the carrier wheel. This willensure not only correct positioning of the rotor shaft endwise (laterally of the carrier wheel) but will also ensure firm It is convenientlyposition. Such supply and delivery of these rogripping of said shaftduring carriageof therotoi from position to position of the carrier Wheel, step-by-step, and W111 also ensure proper reten.-.- tion: of the rotor in place on the carrier wheel: prior to and directly after engagement of the belt...

which will be presently explained.

Theleading end of the spring lug'i3 may be,

slightly bent or otherwise formed. outwardly, as.

shown in Figure.24 tofacilltate engagement and:

disengagement of thelrotor shaft therewith.

Wh1lel have mentioned that all of said retainers may be secured in place by the same screws 6'5 which hold the several brackets to,

the carrier wheel, still in some cases it may be- 5 found desirable to providedistinct sets of screws for these two functions, so that the retainers may be setinto place or removed independently or the. several brackets I provide a closed-belt l5 which is suitably supported and journalled to travel in contact with the exposed cylindrical surlaces of the several rotors. This belt passes over the driving pulley T6,.and over the two corner pulleys l! and 18, and then over the take-u pulley l9, and returns over the faces of the several rotors 33 33 33 33 and 33 'respectively, and backto the driving pulley, thus providing the closed path of travel for the belt, the direction of travel being as shown,

by the several arrows; and. it will be seen that by this arrangement all rotors are simultaneously driven in the same angular direction while in contact with said belt. itself will serve to press each of said rotors against the surface of the corresponding insert 58 while belt engagement with the rotor is main tained. It will also be seen that each rotor may be readily suppliedinto its position on the carrier wheel at the supply position, and may be readily delivered from the carrier wheel at the delivery tors is also readily effected due to the spring manner in which each rotor shaft is grippedby the retainers already described.

The rotors are supplied successively to the car rier wheel at correct positioning in the following manner:

A rotor supply track -is provided adjacent to the supply position, this track including the parallel rails SI and 82' secured to or comprising a portion of a bottom rail 83 (see Figures 2, 4 and 5-)-, and at spacing sufficient to accommodate the body portions ofthe several rotors, and at elevation sufficient to ensure that each rotor is supported by riding of its projecting shaft portions 1 on the respective rails.

continuous feed towards said wheel); and said forward portions terminate adjacent to the, receiving position of the carrier wheel, as well shown in Figures 4 and 5. One of the rotors isshown insaid' figures in correct position for transfer towthecarrier wheel. Carried by the side rails 8i. and.,-82"c1oseto said transfer position are the leaf: springs 84 and 85 which reach towards the edge portions of the carrier-wheel as well shown in Figures 4 and 5. These springs are, conveniently thus carried by securing their outer ends tothe small brackets 8'6 which'are in turnsecured to the faces of the track rails, as well Further, that said belt shown in Figures 4 and 5. The free ends of the spring leaves are slightly up-turned as shown in said Figures 4 and 5 so that as each rotor moves down to its last position on the rails its shaft end portions which overlie the rails come against these upturned ends of said leaf springs and are retained by them against further advancement, the said rotor shaft ends also engaging the peripheral surfaces of the edge portions of the carrier wheel as is well shown in said Figures 4 and 5. Thereafter, when the carrier wheel is next advanced its next faces 62 will come against such projecting portions of the rotor shaft and force such rotor to advance with the carrier wheel during completion of such advancement of saidwheel, thus forcing the rotor shaft end portions over the spring ends, the springs yielding for that purpose, and releasing the said rotor from further engagement with the supply rails.

Such so gathered rotor will then also be brought into engagement with the belt surface,

since that belt is so held that its path of travel will make this relationship effective, and directly that the rotor is released from the supply rails it will be pressed by the belt against the rotor surfaces of the inserts 58, and this relationship will be retained until completion of travel of such rotor stepby-step with the carrier wheel to thedelivery position.

The delivery of each rotor is effected into a trough or channel 81 located above the supply track already described. This trough includes the

side flanges

88 and 89, and the bottom web 9%]. Said flanges are sufficiently spaced from each other to accommodate the rotor bodies, leaving the rotor shaft end portions projecting over the side flanges as shown in Figures 4 and 5.

The rear or outer end of this receiving channel is closed by the end plate 9| and the receiving end of this channel is provided with a tongue or prong 92 which comprises an inward extension of the channel floor or web, and terminates close to the channel or depression 32 of the carrier wheel. In fact, this prong preferably reaches well into said channel 32 so as to better engage the oncoming rotor which is to be taken thereby and is to be delivered into the receiving channel.

This prong is slightly bent upward as shown in Figures 4 and 5 so that as the oncoming rotor is engaged with such prong, said rotor is drawn away from the carrier wheel, the rotor shaft being disengaged from the retainers of the carrier wheel, and such disengagementv being readily effected due to the spring engagement of the retainer G8 with the adjacent shaft end. Upon such disengagement of the rotor from the carrier wheel said rotor will run down along the slanting prong 92 and into the receiving channel and well away from the carrier wheel itself.

Having thus explained the more essential elements of my present grinder and its principles of operation, I shall now describe the means whereby said elements are conveniently supported and certain of them are driven to perform their several functions: 7

A base plate 93 is provided and upon which the several elements are mounted. This-base plate carries the two stands 94 and 95 wherein the carrier wheel shaft 95 is journalled. The body portion of the carrier wheel is keyed or otherwise se-' cured to this shaft 96 so thatsaid shaftmay serve to either rotate the wheel or to lock it in advanced position. These stands include the bearingreceivers Q! and 98 wherein the shaft bearings 99 these shaft bearings ly compressed. The sleeve is also provided with the additional slots Iot I05 and [86 which reach along sufficient length of the sleeve to include the encircling rings I82 and IE3, but these slots do not completely sever the sleeve into distinct segments. They, however, serve to increase the compressibility of the sleeve for shaft gripping purposes. The inside bore I07 of this sleeve receives the bearing portions of the carrier shaft 96, and by compressing the sleeve bearing the shaft will be gripped with a braking force determined by the extent of such gripping force. The bearing receivers 9i and 98 are provided with slightly tapered bores E68 and I839, and the rings I82 and I63 of the bearing sleeves are also formed with peripheral surfaces of slightly conical form to correspond with such conical surfaces I68 and it)?! of the bearing receivers. Thus, by shifting each'bearing sleeve slightly endwise it will be subjected to a compressing force which will contract such bearing sleeve against the shaft bearing portion, with a gripping and braking force dependent on the endwise force to which the sleeve is subjected.

The threaded end portions I84 and 35 of the bearing sleeve receive the setting nuts i it and l I I which engage the end faces of the bearing receivers 91 and 98, so that by turning these nuts in proper direction and in proper harmony each bearing sleeve can be set back and forth slightly to thereby develop the desired amount of braking action on the carrier shaft. In this connection it is noted that as the carrier wheel is advanced step-by-step such advancement is relatively slow; but furthermore, after completion of each such advancement of the carrier wheel said wheel should be retained firmly against further rotative movement during the finishing grinding operation, and until the next advancement is performed. In other words, the shaft of this carrier wheel is not freely journalled in the usual sense, but is rotatable but under such restraint that upon discontinuance of such rotating force the shaft will immediately'come to rest in the exact desired position, and will be retained at rest in such position until afterwards and purposely again advanced. These gripping bearings enable such result to be secured. It is, however, noted that in all cases the carrier wheel and its shaft should be retained in exact centralized position and condition, so that the several faces of the inserts 58 will always be exactly and uniformly positioned with respect tothe grinding wheel,

It may be found desirable to place a block of hard wood or fiber or the like, H2 in the split opening of each bearing sleeve, same being shown at the upper portion of Figure 14. Such block will be sufficiently compressible to enable the production of the desired gripping and braking action, but will retain the bearing sleeve under control during the adjustments of the nuts H9 and Hi. Furthermore, a lock pin H3 may be extended through each bearing receiver ill and 98, and into the bearing sleeve (into the split slot thereof) to retain such bearing sleeve againstrotation with the carrier wheel shaft. Such lock pin is slightly narrower than the slot in the bearpressed as already explained herein.

mea re Between the stands: 94 and 95 andthe carrier wheel. are located theuframe plates ll l'and H5, which are carried by and secured to the baseplate. These frame plates are provided with ample openings to pass the carrier wheel shaft as shown in Figure 5. These frame plates carry bhB belt idler pulleys l1 and 18 by means of the transverse rods IIS and I IT, said rods being provided with the spacer sleeves I it? and I I9 to retain the respective pulleys at proper spacing. with respect to the frame plates and in proper alignment with the path of belt travel. The take-up pulley 'IB'is directly mounted on a shaft I2!) which extends through. the slotted openings I2I and I22 of the frameplates (or of plates secured to said frame plates, as shown), to positions outside said frame plates. Secured on the projecting ends of this shaft I2il are the pulleys E23 and I24 located ou side of said frame plates; and the steel tapes I25 and IZS, or the like, connected to and wound on: these pulleys have their free ends connected to the pull springs I2? and. i 28, respectively. These springs are adjustable as to tension by suitable means, such as by'turnin'g the screws I29 to which their free ends are connected. The shaft I carries the pinions I35 and I3I which mesh with rack bars I32 and i-33 carried by the frame plates or by plates attached thereto. It willnow be seen that the pulls created on the tapes I and I26 by their respective springs will tend to rotatethe pulleys I23 and I24," thus also tending to rotate the shaft Hit, and such rotativetendency is communicated through the pinions' I39 and IBI to the rack" bars, thus developing a translatory force against said. rackbars, which force-tends to draw the shaft forwardly with respect to the rack bars. This will place a strain on the belt proportional to thepull exerted bythe springs, thus keeping the belt under desired tension; and. also making provision for slight back and forth movements of the take-up pulley 79 required during the operation of the machine. In this latter connection it will be'noted that as the carrier wheel isadvanced from one step position to the next, the

positions of the carried rotors are advancedwith respect to the positions of the idler pulleys i1 and I8, and due to slight angularity of the belts riding over these several pulleys there will be desirability of provision for slight back and forth movementsof the take-up pulley as already explained.

In connection with the spring take-uparrangement acting on the take-up pulley i9 through the steel tapes, reference to Figure 3 shows thatthe diameters of. the pulleys I23 and. I24 is greater than that of the pinions I and I 3i, so thata proper resultant of'forces is developed to ensure the desired pull being created on the belt as here tofore explained.

Furthermore, and asa further detail of con struction, I have shown the. frame-plates H4 and H5 as provided with the relativelylarge slotted openings I34 audit-e (see -Figures 2, 3, 4. and 5),

and the previously-mentionedslottedopenings.

I2I and I22 are" formedin side plates I35 and I37: which are set onto the outside faces of the frame plates H4 and. ii5-respectivel-y, and secured thereto, over the openings tilt and I35. Then the rack bars I32 and 533 are secured tothe. plates I36 and I31 by screws or. the like; and in such position that said rack} bars will set directly against the bottom edges'oftheslotted opening-s.- I'34' and 35 of theframe-platea These frame plates also carry a crossbar I38,

preferably welded to said frame plates; and the:

rotor receiver channel. 87 is then securedtoand carried by this cross bar-'as 'well shown'in Figures.

endaof a shaft Ifitjournalled in. theboxes I l-0- andi i'l Whichi are'ecarriedby the brackets securedto theibase plate-as well shown in Figures 1, 2,. 3; 4,. .5 andJL Theother end of said shaft carries the pulley i tzwher'eby said shaft is belt driven. Mounted on the: base plate at a convenient location isthe motor driven gear reducer drive shown at the-left hand portion of Figures 1 and 2. This drive means includes-the motor I43 driving. theareducer I44 through. suitable worm and worm-gear. reduction; and the reducer shaft IAB-carries the belt pulley I46 which drives the pulley I42; through themedi-um of the belt I iI. This reducer shaft 445 also drives or carries a sprocket I l-81; which drives another sprocket I49 through the mediumof the chain drive I50. Saidforthe. belt, and also carries an idler tension sprocketllfifi for the chain. These idlers are vertically. adjustableby movement of their carrying studs in the vertical slots Iii-land I58 (see Figure'l').

The .step-by-step. advancements of the carrier wheelIare secured by a rock. pawl reciprocated periodically, and engaging a ratchet wheel carried by or secured to the carrier wheel or to the carrier wheel shaftdescribe:

Mounted on the carrier wheel shaft and secured to the carri'erWheel-is the ratchetwheel I59 (see Figures .1, 2, 4,5 and 6.). This ratchet wheel has a number of teeth. equal-to the number of step-by-s'tep'positions for which the carrier wheeris designed; so' that. by advancing the ratchet wheel one tooth' ata'time the carrier wheel. is likewise so advanced from grinding po sition'to grinding position. This ratchet'wheel is drivingly connected to'the carrier wheel as by the pin I 60" (see Figure 6');

Rockingly mounted on thecarrier wheel shaft 93 adjacent to'the ratchet wheel is the rock arm I6I. The upper end'of this rock-arm carries the pawl Hi2 which engagesthe'teethof the ratchet wheel," so that forward" movements of this pawl (being backward movements of the lower end' of the rock arm), serve to'advancethe ratchet wheel. C'arriedbythefree end of the chain driven shaft I 5I is the-crank arm I6 3 having the crank pin I64; This crankpin I 64 engages a connecting rod box I 65 (see Figures 1, 2, 3 and 4') to which is connected the connecting rod I66. The rear end of. this ccnnec'ting'rod connects to the lower end of the rockarm iti, so that rotationsof the crank serve to effectv reci'procationsv of the connecting rod, and thusstep-bwstep advancements of the carrier wheel. Suitableadjusting. means such as the-companion nuts I61. and ISB'may be provided Tliese parts I shall now 'tion' such that the rotor shaft to be worked will come to finish position on the line 43 of Figure 8. It will also be noted that this pawl and ratchet advancement will providea substantially sinusoidal movement of the carrier wheel advancement, v y

It has been pointed out that I have provided means to hold the carrier wheel in advanced position by a braking actionj I have a1s0,'as a precaution, provided a pawl I69, carried by the pin l'lll extending inwardly from the frame plate I M, which pawl will engage the ratchet wheel to prevent retrograde movement thereof, and therefore hold the carrier wheel against accidental backward movements. A spring I10 is provided to keep this pawl in engagement with the ratchet wheel. 7

It will be understood that the grinding wheel 31 has its shaft 4| suitably journalled, and .for convenience I have herein shown such journal as carried by the stand I'll. This stand may be adjusted towards and away from the carrier wheel of the grinder so that exact adjustment of the clearance and exact determination of the finish size of the rotor shafts may be secured. Such back and forth adjustments are indicated in Figure 8 by means of the arrows H2 and H3.

It will also be understood that the grinding peripheral surface of the grinding wheel should be exactly dressed to ensure that said surface shall be parallel to the rotor shafts being finish ground. Such dressing of the grinding wheel surface is usually done by means of a diamond tool. I have therefore shown in Figures 1, 3 and 4 a stand I14 extending up from the base plate 93 and having suitable means to lockingly secure a diamond dressing tool H5 in place on the upper portion of such stand; the arrangement being such that the dressing elevation of said tool is in horizontal alignment with the grinding position of the grinding wheel (namely, the line 43). By shifting the base plate and grinder proper laterally (the grinding wheel having been moved back out of the way), to a position where the diamond dressing tool is opposite to the grinding surface of the grinding wheel, and then re-setting the grinding wheel back towards the carrier wheel to the correct position, the diamond tool may be brought into engagement with the grinding surface to dress the same; and by then moving the grinder itself back and forth during the dressing operation the grinding surface may be exactly dressed. This will bring said surface into correct parallelism with the carrier wheel itself.

To make possible such back and forth movements of the grinder I have shown in Figures 2, 3, 4, 5, 6 and 7 the rails I16 and I1! which ride on the stationary rails I18 and I19 in well understood manner.

Since when grinding the projecting ends of rotor shafts there are two such ends for each rotor, one at each end of the rotor, provision may readily be made for simultaneously grinding both said ends by suitably forming the grinding wheel with an encircling groove to accommodate the body of the rotor, and with two edge portions, one at each side of said encircling groove, said edge portions being provided with peripheral grinding surfaces corresponding to the shaft end portions to be ground, and corresponding to the edge portions of the carrier wheel. Both said grinding surfaces of the grinding wheel can be readily dressed by use of the diamond tool so that they will both grind and finish to exactly the same shaft diameters. Of course, if desired, each 'end portion of a rotor shaft may be ground and finished independently of the other end portion of such shaft. As an example of a grinding operation performed on a machine embodying the features herein disclosed, I may mention a belt travel at rate to give substantially 240 R. P. M, rotative speed to the rotors being ground and finished, and also that during the rest interval during which the shaft ends of such rotor are being finished said rotor makes substantially 20 revolutions, so that it is effectively finished to an exact size and to an exact surface. Such rates and number of revolutions are mentioned merely by way of illustration, and not as a limitation.

I claim:

1. In a shaft grinding and finishing machine, a carrier wheel mounted for rotational advancement, friction means to oppose such rotational advancement under a sustained amount of friction, means to supply shafts to be ground to uniform size to said carrier wheel parallel to the axis of carrier wheel rotation and with a predetermined spacing on said wheel, a grinding wheel mounted for rotation on an axis parallel to the carrier wheel rotational axis, and a single means for simultaneously rotating said shafts relative to said carrier wheel and retaining said shafts on said carrier wheel from a position in advance of the plane extending through the carrier wheel and grinding wheel axes to a position on the other side of said plane,

2. Means as specified in claim 1, together with means to advance the carrier wheel with an intermittent step-by-step movement against said friction means.

3. Means as specified in claim 1, wherein said carrier wheel advancing means acts intermittently and is effective to ensure rest of said carrier wheel with each shaft position on the carrier wheel successively substantially in alignment with the plane passing through the carrier wheel and grinding wheel rotational axes.

4. In a shaft grinding and finishing machine for grinding and finishing shaft ends projecting from cylindrical bodies of larger size than said shaft ends, a carrier wheel mounted for rotatable movement, a pair of peripheral shaft engaging and locating circumferential surfaces on said carrier wheel spaced from each other longitudinally of said carrier wheel a distance to directly support the shaft ends of a body with the cylindrical portion between said shaft ends free for rotation, means to retain the body with its shaft ends to be ground and finished against said locating surfaces to thereby retain said shaft ends at a predetermined distance from the rotational axis of said carrier wheel, said retaining means comprising a belt element in engagement with the cylindrical portion of the body between the shaft ends, a grinding wheel located at a predetermined spacing from said shaft engaging surfaces of the carrier wheel and rotatable on an axis parallel to the carrier wheel rotational axis, and means for advancing the carrier wheel rotationally to carry a body which is retained on the carrier wheel periphery so that the shaft ends of said body are brought into grinding position with respect to the circumference of the grinding wheel.

5. Means as specified in claim 4, wherein said peripheral shaft engaging and locating surfaces are ground to an exact circular surface with respect to the axis of carrier wheel rotation.