US2091456A - Cam grinding machine - Google Patents

Description

Aug. 31, 1937. c. J. RYBlCK CAM GRINDING MACHINE Filed Oct. 15, 1936 2 Sheets-Sheet 1 R. O m M BY Ckesfer c/Fyfi/w? ATTORNEY.

2 Sheets-Sheet 2 INVENTOR.

e/lesfer- JFyJ/wf ATTORNEY.

C. J. RYBICK CAM GRINDING MACHINE Filed Oct. 15, 1956 Aug 31, 1937.

Patented Aug. 31, 1937 FATE T O F Fl CE CAM GRINDING MACHINE Chester J. Rybick, Cleveland, Ohio Application October 15,

12 Claims.

This invention relates as indicated to cam grinding machines and more particularly to that type of cam grinding machine especially adapted to grinding edge cams.

The principal object of my invention is to provide a machine for automatically grinding edge cams, which is not only efiicient to operate but comparatively cheap to manufacture as well.

Another object of my invention is to provide a machine which will efficiently turn out a large number of cams in a comparatively short space of time.

Other objects of my invention will appear as the description proceeds.

To the accomplishment of the foregoing and related ends, said invention then consists of the means hereinafter described and particularly pointed out in the claims.

The annexed drawings and following description set forth in detail certain mechanism embodying my invention, said means constituting, however, but one of various mechanical forms in which the principle of my invention may be used.

In said annexed drawings:

Fig. 1 is a top plan view of my invention.-

Fig. 2 is a side ele-vational view of my device.

Fig. 3 is a part elevational and part sectional View taken substantially on the line indicated by 3-3 in Fig. 2.

Fig. 4 is a part sectional and part top plan view of the clutch mechanism taken substantially on the line indicated by the numerals 44 in Fig. 2.

Fig. 5 is a sectional view of the clutch mechanism taken substantially on the line indicated by the numerals 55 in Fig. 2.

Fig. 6 is a perspective View of the cam shaft and the adjustable offset arm.

Fig. 7 is a side elevational view of part of the variable speed mechanism showing a cam having more than one clip just as the clutch has been thrown into slow speed.

Fig. 8 is the same as Fig. '7, but showing the cam as its second dip approaches the cam follower, wherein the variable speed mechanism has been thrown into low speed for the second time during one revolution of the cam.

At the present time there is no machine of comparatively low priced construction which will adequately suit the needs of the average manufactur'er who uses edge cams on his machines. My machine is directed to overcome this particular disadvantage, although there are several othor difficulties in the grinding of edge cams which my device is designed to overcome.

1936, Serial No. 105,726

The three main obstacles which I encountered are (-1) the abrasive wheel, being wider than the cam tends to become grooved thus making the finished cam too large, (2) the rough cam can not take a very deep cut at certain places necessitating rotation of said cam a number of times, and controlling the depth of such cut by suitable mechanism, and (3) the necessity for placing different cams on the shaft at varying angles in a vertical plane and rotating them at different speeds during one revolution, depending upon the location and depth of the dip or clips.

All of these difiiculties have been overcome in my machine, as will be more readily seen as the description proceeds.

Referring now more particularly to the drawings and more especially to Figs. 1 and 2, the base or work table of my device is indicated by the numeral I. Set in a horizontal position in this base is the main or driven shaft, 2. This shaft is drivenby means of a motor, 3, and belts, 4 and 5, which are connected respectively to the coneclutch pulleys, 6 and 1.

Since the speed of shaft, 2, will vary from time to time, it becomes necessary to place a sleeve, 8, over the opposite end of shaft, 2, in order to insure a single speed for the moving parts which operate from this point. A third belt, 9, is then connected to the shaft of the motor, 3, to the pulley, In, on the sleeve, 8. Also situated on the sleeve, 8, are pulleys, I I and I2, which are in turn connected respectively to pulleys, l3 and M, on the secondary shaft, l5. At the outer end of shaft, I5, is situated another pulley, i6, which is connected by means of a belt, H, to a pulley, [8, on the shaft, I9, which rotates the abrasive wheel, 20.

Pivotally mounted on the shaft, l5, are arms, 2!, 22 and 23. The ends of arms, 2| and 22, support the bearing, 24, through which is rotatably mounted a shaft, l9.

Arm, 23, supports, at its outer end, the cam follower, 25. On one end of shaft, 2, is mounted a worm 26, which in turn is connected to a worm gear, 21. From the worm gear, 21, extends a shaft, 28, on the opposite end of which is mounted another worm, 29, which is connected with the worm gear, 30. Said worm gear, 30, is mounted in a bearing, 3!, through which extends a shaft, 32. On one end of shaft, 32, is placed an adjustable offset arm, 33, which supports a shaft, 34, on which the master cam, 35, and the cam to be ground, 36, are mounted.

It will be seen from the foregoing, that due to the revolution of the sleeve, 8, the abrasive wheel, 20, is made to revolve. Furthermore, the

, oluticn.

revolution of shaft, 2, also causes shaft, 32, to revolve, which in turn revolves the master cam, 35, and the cam to be ground, 35.

In order to overcome the first difficulty above mentioned, namely that of insuring an even surface at all times on the abrasive wheel, I have placed a drum earn, 3?, on the shaft, 55. A pivotal point, 38, extends from the arm, M, to which is connected a rod, 39. One end of the rod, 353, is placed in the drum cam, 37. The other end is placed at the end of shaft, 59. As the shaft, 55, and consequently the cam, 3?, revolves, it will be seen that the shaft, is, and the abrasive wheel, 2i will move back and forth,

t due to the reciprocal motion of the end of. rod,

3%. Since this operation is continuous throughout the grinding of the cam, it will be seen that an even surface on the abrasive wheel will result.

The next important thing to consider is the mechanism which adjusts the pressure of the abrasive wheel on the cam to be ground. A sectional view of this feature is shown in Fig. 3. The brace, which is pivotally mounted on the shaft, i5, is indicated by the numeral ifi. EX-

' tending horizontally from the arm, 22, is a short arm, ti, the end of which is situated between the upper and lower ends of the brace, All. A threaded shaft, 32, extends through the upper terminus of the brace, Ml, having its lower end secured to the end of the arm, M. It will be seen from this construction that upon the raising or lowering of the threaded element, $2, the arm, 22, and consequently, the abrasive wheel, 2%, will be raised or lowered accordingly.

As hereinbefore explained'this adjusting device is employed to prevent the abrasive wheel, 2%, from cutting into the cam to be ground, too deeply at any one time. The usual procedure is to use this adjusting mechanism to raise the abrasive wheel, 20, a sufiicient amount during the first few revolutions of the cams to take only a slight out. As cam, 35, approaches the size and contour of the master cam, 35, the abrasive wheel, may be lowered by means of the adjusting mechanism, so that the final cut taken will insure the cam to be ground being the same size and contour of the master cam, 35. The adjusting screw, s2, is so arranged that it will be impossible to lower the abrasive wheel, 2E3, any more than is sufficient to bring it in horizontal alignment with the master cam follower,

The next and perhaps most important feature of my invention is directed to the mechanism which automatically varies the speed of rotation of cams, and 36, in order to insure the grinding of every point of the cam to-be ground. The clutch which operates this mechanism is more clearly shown in Figs. 4 and 5, wherein the coneclutch pulleys, 6 and 'l, are shown mounted on the shaft, 2. The only moving part of this mechanism is the center piece of the clutch, #33, which is keyed to the shaft, 2, and is slidably mounted thereon and controls its speed of rev-- The pulleys, 5 and l, ride loosely on shaft, 2. It will be apparent, therefore, that when the center piece, 63, is in contact with pulley, l, shaft, 2, will rotate at a slower rate of speed than when it is in contact with pulley, 6, since both pulleys are driven from. the same size pulleys on the motor, 3, and the pulley, E, is larger than pulley, 6.

For purposes of convenience, the entire mechanism in the drawings are shown as having just been thrown into the slower speed.

In order to actuate the clutch mechanism, 33, a slotted wheel, Ml, is placed on the end of shaft, The number of openings in wheel, M, is immaterial; however, three are shown in Fig. 2 for the purpose of convenience. Through these slots are slidably mounted fingers, 15 and it, which extend on either side of the wheel. The point at which the clutch will be thrown either into high or low speed will depend on the position of these fingers. Pivotally mounted on the base, i, at point, ll, is a forked rocker arm, 38, which has two prongs. extending upwardly, one on either side of the center of rotation of the wheel, The one prong, ii-3, is placed outwardly the other prong, 5E3, is placed inwardly with respect to the wheel, Ml.

Extending inwardly from the end of rocker arm, 58, is a link, iii, to the end of which is attached a bell crank, pivoted at the point, 52%. To the lower end of. bell crank, 52, is attached a spring, 54%. The other end of spring, 5 5, is secured to a pin, 55, which is attached to an arm, which is pivoted at point, 525. The arm, at, and pivotal point, 5i, are supported by an arm, 58, which extends outwardly from the base, 5.

One end of the arm, 56, is forked, and its upper and lower ends, 555 and terminate in the slot provided for that purpose in the center piece, i l, of the clutch mechanism.

This arrangement has been developed in order to prevent any lost motion between the changing from low to high speeds or vice versa. It is necessary, in order to secure greatest efficiency, that this action be quick, and for this reason the spring arrangement has been devised. A well known principle is utilized in obtaining this action, since the clutch mechanism, 33, will not be moved as the spring is forced into the dotted position indicated by 54, until it passes the position of dead center. Immediately upon the passing of dead center, the spring will pull the clutch mechanism, it, into contact with pulley, 6; thus speeding up immediately the rotation of the cams.

As before stated, the position of the fingers, do and ll will determine at what points the speed of rotation of the cams will be either decreased or increased. As shown in Fig. 2, the clutch, 43, has just been thrown into low speed because of the fact that the dip in the cam is nearing the cam follower and the abrasive wheel. As the wheel, fil i, rotates, finger, it, will eventually contact the prong, 5d, of the rocker arm, 38, forcing the end upwardly into the dotted position lli. By the action of this arm on the bell crank, 52, said bell crank will be moved into position 52, the spring into the position 54', the arm, 56, into its position 56 and the clutch, ts, in contact with pulley, 6, immediately increasing the speed of the cams.

The fingers, 45 and 46, are made slidable in order to regulate at what point the speed will be varied because of the variation in the position of the dips in various cams.

By the use of this method, the number of times which the speed may be varied during one revolution of the cam will depend upon the number of clips in such carn.

Figs. 7 and 8 show a cam having two dips instead of one. By virtue of finger, d5, having contacted prong, it, of rocker arm, it, the clutch mechanism has just been thrown into low speed. When finger, 56, reaches prong, 50, during the revolution of wheel, 44, the speed of rotation of the cam will again be increased. During the same revolution, when the second dip of the cam nears the cam roller, 25, finger 45' Will contact prong, 49, throwing the clutch into slow speed. Then when finger, 46', contacts prong, 5B, the speed will again be increased. Thus, it will be seen the speed has been varied twice during one revolution of the cam, and it will be apparent that this may be done as many times during one revolution as is necessary.

It may be desirable, in the case of certain cams, to have their center of rotation nearer to the shaft, 32. For this purpose, the offset arm, 33, is provided with a slot, 6|, through which the cam shaft, 34, is secured in any desired position by means of the nut, 62. Shaft, 32, passes through the opening, 63, in the arm, 33, and, being secured at that point, causes said arm to rotate.

After the cam shaft, 34, has been secured in the slot, 6|, in the desired position, the master cam is then placed on and keyed to said shaft. The spacer, 64, is then placed next to the master cam and the cam to be ground, 36, is placed next to the spacer and secured on the shaft by any desired means, such as a nut.

It will be seen, therefore, from the foregoing description that an efficient machine for grinding edge cams has been devised which has overcome all of the difiiculties which have been encountered heretofore.

Other forms may be employed embodying the features of my invention instead of the one here explained, change being made in the form or construction, provided the elements stated by any of the following claims or the equivalent of such stated elements be employed.

I therefore particularly point out and. distinctly claim as my invention:

1. A cam grinding machine comprising in combination a stationary work table, a horizontal shaft situated at one end of said work table to support a master cam and the cam to be ground, a plurality of arms pivotally mounted on and extending forwardly from a secondary shaft at the opposite end of said work table to support a cam follower and an abrasive wheel, and means to horizontally reciprocate said abrasive wheel comprising a rod pivoted at an intermediate point on one of said arms, having one end positioned in a drum cam and the other end secured to the shaft on which said abrasive wheel is mounted.

2. A cam grinding machine comprising in combination a stationary work table, a main shaft and a secondary shaft mounted horizontally in said work table, a plurality of arms pivotally mounted on and extending forwardly from said secondary shaft to support a cam follower and an abrasive wheel, a third shaft mounted horizontally at the forward end of said work table to support a master cam and the cam to be ground, means to adjust the pressure of said abrasive wheel on said cam to be ground and means pivotally mounted on one of said arms to horiwheel and adj'ustably supported between the terminal of said brace by a threaded element.

4. A cam grinding machine comprising in combination a work table, main and secondary shafts mounted therein, means pivotally mounted on and extending forwardly from said secondary shaft to support an abrasive Wheel and a cam follower, a third shaft to support in horizontal alignment with each other a master cam and the cam to be ground, means to horizontally reciprocate said abrasive wheel, means to adjust the pressure of -said abrasive wheel on said cam to be ground, and means to vary the speed of rotation of both of said cams simultaneously and at definite intervals during one complete revolution thereof.

5. A cam grinding machine comprising in combination a work table,-main and secondary shafts mounted therein, means pivotally mounted on and extending forwardly from said secondary shaft'to support an abrasive wheel and a cam follower, a third shaft to support in horizontal alignment with each other a master cam and the cam to be ground, means to horizontally reciprocate said abrasive wheel and means to vary the speed of rotation of both of said cams simultaneously and at definite intervals during one complete revolution thereof.

6. A cam grinding machine comprising in combination a work table, main and secondary shafts mounted therein, means pivotally mounted on and extending forwardly from said secondary shaft to support an abrasive wheel and a cam follower, a third shaft to support in horizontal alignment with each other a master cam and the cam to be ground, means to adjust the pressure of said abrasive wheel on said cam to be ground and means to vary the speed of rotation of both of said cams simultaneously and at definite intervals during one complete revolution thereof.

7. A cam grinding machine comprising in combination a work table, main and secondary shafts mounted therein, means pivotally mounted on and extending forwardly from said secondary shaft to support an abrasive wheel and a cam follower, a third shaft to support in horizontal alignment with each other a master cam and the cam to be ground, means to horizontally reciprocate said abrasive wheel, means to adjust the pressure of said abrasive wheel on said cam to be ground, means to decrease the speed of rotation of both of said cams as a dip in said cams approaches said cam follower and abrasive wheel, and means to increase said speed after said dip has passed said cam follower and abrasive wheel.

8. In combination with a cam grinding machine of the character described, means for decreasing the speed of rotation of the master cam and cam to be ground each time a dip in said cams approaches the cam follower and abrasive wheel and increasing said speed each time a clip has passed said cam follower and abrasive wheel comprising a low and high speed, clutch pulleys riding on a driven shaft, each rotatable by means of a motor, a clutch keyed to said shaft between said pulleys, a wheel having a plurality of arcuate openings therein, fingers extending on either side and perpendicularly from said wheel slidable in said openings, a forked arm having a prong extending on either side of the center of said wheel to contact said fingers at certain times during the rotation of said wheel, a bell crank connected by a link to the end of said forked arm, and a spring connecting the end of said bell crank with a pivoted arm to operate said clutch mechanism with a snap action.

9. A cam grinding machine comprising in combination a work table, main and secondary shafts mounted therein, means pivotally mounted on and extending forwardly from said secondary shaft to support an abrasive wheel and a cam follower, a third shaft, mounted off of its center of rotation, to support in horizontal alignment with each other a master cam and the cam to be ground, means to decrease the speed of rotation of both of said cams as a dip in said cams approaches said cam follower and abrasive wheel, and means to increase said speed after said dip has passed said cam follower and abrasive wheel.

10. A cam grinding machine comprising in combination a work table, main and secondary shafts mounted therein, means pivotally mounted on and extending forwardly from said secondary shaft to support an abrasive Wheel and a cam follower, a third shaft, mounted off of its center of rotation, to support in horizontal alignment with each other a master cam and the cam to be ground, means for adjusting the proximity of said third shaft to its center of rotation, means to decrease the speed of rotation of both of said cams as a dip in said cams approaches said cam follower and abrasive wheel, and means to increase said speed after said dip has passed said cam follower and abrasive wheel.

11. A cam grinding machine comprising in combination a work table, main and secondary shafts mounted therein, meanspivotally mounted on and extending forwardly from said secondary shaft to support an abrasive wheel and a cam follower, a third shaft to support in horizontal alignment with each other a master cam and the cam to be ground, means to horizontally reciprocate said abrasive wheel, means to adjust the pressure of said abrasive wheel on said cam to be ground, means to decrease the speed of rotation of both of said cams as a dip in said cams approaches said cam follower and abrasive wheel, means to increase said speed after said dip has passed said cam follower and abrasive wheel, means to support said third shaft off of its center of rotation, and means to adjust the proximity of said third shaft to said center of rotation.

12. A cam grinding machine comprising in combination a work table, main and secondary shafts mounted therein, means pivotally mounted on and extending forwardly from said secondary shaft to support an abrasive wheel and a cam follower, a third shaft mounted off of its center of rotation, to support in horizontal alignment with each other a master cam and the cam to be ground, and means to adjust the proximity of said third shaft to its center of rotation including a slotted arm rotating about one end as an axis and supporting said third shaft at its other end, said shaft being slidable in said slotted arm.

CHESTER J. RYBICK.

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