US2448874A - Hydraulically operated wheel feeding mechanism - Google Patents

Description

Sept. 7, 1948. c. G. FLYGARE ET AL 2,448,374

HYDRAULICALLY QPERATED WHEEL FEEDING MECHANISM Filed Nov. 2, 1946 IN VEN TORS CARL G. FLYGARE CHARLES C.ALVOF?D Patented Sept. 7, 1948 HYDRAULICALLY OPERATED WHEEL FEEDING MECHANISM Carl G. Flygare and Charles C. Alvorll, Worcester, Masa, asslgnors to Norton Company, Worcester, Mass., a corporation of Massachusetts Application November 2, 1948, Serial No. 707,400

Claims.

The invention relates to grinding machines and more particularly to a grinding wheel feeding mechanism.

One object of the invention is to provide a simple and thoroughly practical grinding wheel feeding mechanism. Another object of the invention is to provide a hydraulically operated wheel feeding mechanism which is arranged to cause a rapid approaching movement of the grinding wheel, then a slow shoulder grinding feed of the wheel until the grinding wheel engages the peripheral surface of the work at which time the infeed is automatically reduced to a slower uniform body feed. Another object of the invention is to provide a wheel feeding mechanism in which a mechanism including a work engaging feeler automatically changes the rate of infeed when the periphery of the grinding wheel engages the body portion of the work to be ground regardless of the initial diameter of the bodyportion.

A further object of the invention is to provide a wheel feeding mechanism in which the rapid approaching or shoulder feed of the grinding wheel continues until the periphery of the grinding wheel engages the cylindrical body portion of the work at which time the feed is automati-- cally reduced to a predetermined and uniform grinding feed. Another object of the invention is to provide a wheel feeding mechanism with a control means which is governed by the diameter of the work being ground for automatically changing the rate of infeed to a predetermined grinding feed when the grinding wheel engages the periphery of the work piece. Another object of the invention is to provide a hydraulically actuated electrically controlled feeding mechanism in which a work engaging feeler and control means governed thereby automatically changes the rate of feed of the grinding wheel to a grinding feed when the grinding wheel moves into engagement with the work piece being ground. Other objects will be in part obvious or in part pointed out hereinafter.

The invention accordingly consists in the features of construction, combinations of elements, and arrangements of parts, as will be exemplifled in the structure to be hereinafter described, and the scope of the application of which will be indicated in the followingclaims.

In the accompanying drawings, in which is 2 shown one of various possible embodiments of the mechanical features of this invention, Fig. 1 is a diagrammatic showing of the hydraulically actuated electrically controlled grinding wheel feeding mechanism.

A grinding machine has been illustrated in the drawings comprising a base 9 which supports a transversely movable grinding wheel slide Ill on the usual V-way and flat way (not shown). The wheel slide It serves as a support for a rotatable grinding wheel II. A rotatable work support is provided for rotatably supporting a work piece l2 in order that its peripheral cylindrical surface may be ground. The work support has not been illustrated since it is not considered to be a part of the present invention. A conventional work support comprising a head stock and a footstock may be utilized such as for example that shown in the expired U. S. patent to C. H. Norton, No. 762,838, dated June 14, 1904, to which reference may be had for details of disclosure not contained herein.

The wheel slide I0 is provided with a depending half nut I3 which meshes with or engages a rothe feed screw I4.

tatably mounted feed screw it. The right hand end of the feed screw I4 is supported in a slidably mounted bearing IS. The screw l4 may be rotated by the old and well known manually operable cross feeding mechanism such as for example that shown in the above mentioned expired U. S. patent.

In order to feed the grinding wheel toward and from the work piece, a hydraulically operated mechanism is provided comprising a cylinder I! which is fixedly mounted in the base 9. The cylinder l8 contains a slidably mounted piston H which is connected to a double end piston rod It. The left hand end of the piston rod II is operatively connected to the slidably mounted bearing l5. As illustrated in the drawings, the hydraulic cylinder IS, the piston-ll, and the piston rod l8 are arranged in axial alignment with When it is desired to move the grinding wheel to a rearward or inoperative position such as that shown in the drawings, fluid under pressure may be admitted through a pipe l9 into a cylinder chamber Ill to cause the piston "and associated parts to move toward the right into the position illustrated in the drawing. During this movement or the piston ll, fluid within a. cylinder chamber 2| may be exhausted through a pipe 22. Similarly, when it is desired to cause a forward feeding movement of the grinding wheel, fluid under pressure may be admitted through the pipe 22 into cylinder cham- :ber 2| to cause the piston H to move toward the left and thus transmit a corresponding movement through piston rod 8, the slidably mounted bearing l5, the feed screw l4, the half nut 3, and the wheel slide l8to cause the wheel II to approach the peripheral surface of the work piece l2. During this movement of the wheel slide l8, fluid within the cylinder chamber 28 may be exhausted through the pipe l9.

A fluid pressure system is provided comprising a reservoir 25. A motor driven pump 26 draws fluid through a pipe 21 from the reservoir 25 and passes fluid under pressure through a pipe 28 to a control valve 29. The control valve 29 is preferably a piston type control valve comprising valve stem 38 having formed integrally therewith a plurality of valve pistons 3|, 32, 33 and 34. The valve stem 38 is normally held in its right hand end position by means of a compression spring 35 which surrounds the valve stem 38 and is interposed between the end face of 'the valve casing 28 and a flan 36 which is either formed integral or fixedly mounted on the valve stem 38. In the position of the valve as shown in the drawings, fluid under pressure passing through the pipe 28 enters a valve chamber located between the valve pistons 32 and 33 and passes out through the pipe is into the cylinder chamber 28 to cause the piston I 1 to move toward the right into the position illustrated in the drawings. During this movement of the piston l1, fluid within the cylinder chamber 2| may exhaust through the pipe 22 into a valve chamber located between the valve pistons 3| and 32' and pass out through an exhaust pipe 38 into the reservoir 25.

-In the preferred construction, the valve 25 is arranged to be automatically shifted into a reverse position to change the direction of flow of fluid under pressure by means of an electric solenoid 31. When the'solenoid 31 is energized, in a manner to be hereinafter described, the valve stem 38 will be shifted toward the left against the compression of the spring 35 so that fluid under pressure passing through the pipe 28 will enter the valve chamber located between the valve pistons 32 and 33 and pass outwardly through the pipe 22 into the cylinder chamber 2| to cause an in-feeding or approaching movement of the grinding wheel slide l8 and the grinding wheel II.

In order to control the energization of the solenoid 31, power lines 48 are provided for supplying electrical current to the control system. A push button type starter switch 4| is provided which, when closed, serves to energize a relay switch 45. When the relay switch 45 is energized, a circuit is closed to energize the solenoid 31 and thereby shift the control valve 28 so as to cause a forward feeding movement of the grinding wheel A push button type stop switch 42 is provided to facilitate stopping the forward feeding movement at any time it is desired and thereby deenerg-izing the solenoid 31 so that the released compression of the spring 35 will shift the control valve into the position illustrated in the drawings thereby causing the wheel slide l8 and the grinding wheel H to move to a rearward or inoperative position. A manually operable control lever 43 is pivotally supported on a stud 44 which is preferably supported in fixed relationship with the base 8. The control lever 43 serves to facilitate manual 80W?!- opposite sides of the piston rod l8. pot feed regulator is substantially the same as.

cause the control valve to shift to cause the wheel slide i 8 and grinding wheel H to move to an inoperative position.

A dash pot feed regulator 58 is provided for reducing the rapid approaching movement of the grinding wheel to a slow uniform grinding feed when the grinding wheel reaches a predetermined position. This regulator comprises a pair of dash pot pistons 5| and 52 arranged on diametrically This dash that shown in the prior U. S. Patent to W. H. Wood, No. 2,082,728, dated June 1, 1937, to which reference ma be had for details of disclosure not contained herein. The dash pot pistons 5| and 52 are normally urged in a right hand direction by a pair of compression springs 53 and 54 whic serve to return the dash pot pistons 5| and 52 to inoperative positions when the grinding wheel II is moved rearwardly to its inoperative position. A flanged collar 55 is adjustably mounted on a rearwardly extending portion 56 of the piston rod l8.

The rapid approaching movement of the grinding wheel continues until the flanged collar 55 engages the ends of the dash pot pistons 5| and 52 and moves them toward the left. This movement serves to exhaust fluid from the dash pot cylinder chambers through a passage 51 and through a needle valve 58. By regulating the needle valve 58, the exhaust of fluid from the dash pot cylinders may be regulated so as to produce th desired feed.

Fluid exhausting through the needle valve 58 passes through a pipe 58 and through a throttle valve '58 and a pipe 6| which returns the exhausting fluid to the reservoir 25. In certain types of grinding operations it is desirable to provide not only a rapid approaching but also a slow shoulder grinding feed and then a slower uniform feed during the grinding of the peripheral body portion of a work piece. In order to provide the desired control of the exhausting fluid so as to obtain the different feeds desired, a normally open solenoid valve 63 is provided comprising a valve chamber 62. through thechamber 62 and out through a pipe 64, through a second throttle valve 65 and through the pipe 6| into the reservoir 25. A compression spring 66 serves normally to maintain the valve in an open position. A solenoid 61 is provided which, when energized, causes an upward movement of the valve parts to close the valve and thereby to prevent fluid passing from the pipe "through the pipe .64.

As illustrated in the drawings, the shoulder grinding feed is determined by the setting of the needle valve 58 and the throttle valves 68 and 65. When it is desired to change from a shoulder grinding feed to a body grinding feed, the solenoid 61 is energized to close the valve 63 so that fluid exhausting from the feed regulator 58 through the pipe 58'may pass only through the throttle valve 68. The throttle valve 65 being cut off by the closing of the solenoid valve 63. By manipulation of the throttle valve 68, the desired Fluid passing through the pipe 58 may pass amen and predetermined body grinding feed may be obtained. 7 I i In order to refill e dash pot cylinders duringthe rearward mov ent of the grinding wheel I I so that the feed regulator will be in condition rolthe next grinding operation, a pipe 88 is connected with the pipe ip to'pass fluid to a check valve", through a pipe I8 into the pipe 88. It will be readily apparent from the fore oin disclosure that in the position of the valves as shown in the drawing. fluid under pressure passing throughsame time fluid under pressure is passedthrough the pipe 88 into the cylinder chamber If to move the work engaging feeler I8 into operative engagethe pipe l8 will pass through the pipe 88, through feed be continued until the grinding wheel is about to engage the periphery oi thework to be ground regardless of the initial diameter of the work. In the preferred construction a feeler actuated mechanism is provided which serves automatically to change to a body grinding feed as the grinding wheel ll is-about to engage the perlphery of the work piece II to be ground. This mechanism preferably comprises an adjustably vrnent with the workpiece [2 when the infeedlng V movement of the grinding wheel II is started.

. In order to effect a change of theinfeeding movement of the grinding wheel from either an approaching or a shoulder grinding feed to a body'feed, an adlustably mounted block'll is mounted on the rearwardly' extending portion 81 of the piston rod. The block 84 serves as a support for a normally open limit switch 88. The

limit switch I is provided with an actuating roller 88 which is arranged in the path of a detent 81 which is adjustably supported on the rearwardly extending portion 88 of the piston rod [8;

It will be readily apparent from the foregoingdisclosure that the limit switch 88 is moved with the piston 88 as the feeler- 18 is moved into or out of an operative position. The limit switch 88 is operatively connected to the solenoid 81. when the infeeding movement of the grinding wheel is started by energizing the magnetic starter switch 88, the feeler II will be moved into operative engagement withthe work piece II by movement of the piston 88 which serves to move the block u and the limitswitch u toward the left. The

mounted work engaging feeler 18 which is supported on an upwardly extending arm of a bell crank lever 18. The bell crank lever 18 -is pivotally supported by a stud 11 which is in turn supported by a bracket [8 fastened to the base 8. A micrometer adjusting knob I8 is provided to facilitate adjustment of the feeler 18 relative to the bell crank lever I8. A horizontally extending arm of the bell crank lever T8 is pivotally connected by a stud 88 witha vertically arranged connecting rod 8|. The lower end of the rod II is connected by a stud 82 with a horizontally extending arm of a bell crank lever 88. The bell crank lever 88 is pivotally supported by a stud 84 on a bracket 88 which is fixed to the base 8.

A downwardly extending arm of the bell crank lever 88 is connected by means of a stud 88 with a horizontally arranged piston rod 81.

It is desirable that the work engaging feeler be moved automatically into and out of operative engagement with the periphery of the work piece to be ground in timed relationship with the feeding movement of the grinding wheel l'i This is preferably accomplished by means of a hydraulically operated mechanism comprising a cylinder 88 and a piston 89. The piston 88 is fixedly connected to the double end piston rod 81. A pipe 88 connects a cylinder chamber 8| with the pipe 22. A pipe 82 connects a cylinder chamber 88 with the pipe I8.

, With the control valve 28 in the position shown in the drawing, fluid under pressure passing through the pipe i8 to cause the piston II to movement of the grinding wheel ii, fluid under pressure is passed through the pipe 22 to cause the piston II to move toward the left and at the infeedin'g movement of the grinding wheel will continue 'first at a rapid approaching rate as caused by the piston l1 and then at a shoulder grinding rate as caused by the dash pot pistons 8i and 82 which movement will continue until the detent 81 engages the roller- 86 and closes the limit switch 88. The closing of the limit switch 88 serves to energize the solenoid 81 to close the valve 88. The closing of the valve 88 cuts oil exhaust of fluid through the throttle valve 88 so that fluid exhausting from the dash pot cylinders may exhaust only through the needle valve 88 which is set for a predetermined body grinding feed. It will be readily apparent from the foregoing disclosure that movement of the feeler II as caused by the piston 88 will position the limit switch 8! so that the shoulder grinding feed will l2 regardless of the initial diameter of the work piece.

The operation of this improved feeding mecha- I nism will be readily apparent from the foregoing disclosure. Assuming all adjustments to have been previously made, a work piece i2 is mounted in the machine, the pump 26 is started and the grinding wheel is alsorstarted in rotation for a grinding operation. The infeeding movement of the grinding wheel is initiated by movement of the control lever 88 in a counter clockwise direction to close the starter switch ll which serves to close the relay switch 45 thus energizing the solenoid 81 to shift the control valve 28 so as to admit fluid under pressure through the pipe 22 to start a forward feeding movement of the piston l1 and grinding wheel ll. At the same time, fluid under pressure is passed through the pipe 88 to cause a movement of the piston 88 towardv the left so as to move the work engaging feeler II into operative engagement with the periphery feeding movement caused by the piston i1 is then reduced to a predetermined shoulder grinding feed as governed by the needle valve 88, the

7 throttle valves 60 and 85. The shoulder grinding feed continues until the detent 91 engages the actuating roller 86 to close the limit switch SI. The closing of the limit switch 95 energizes the solenoid 61 to close the solenoid valve 63 thus cutting ofl exhaust of fluid through the throttle valve 6!. The closing of the solenoid valve 63 then allows fluid to exhaust only through the throttle valve 80 which is adjusted to give the desired body grinding feed for grinding the peripheral surface of the work piece l2. The body grindin'gfeed may continue until the work has been ground to the desired and predetermined size after which the control lever 43 may be shifted in a clockwise direction to actuate the stop switch 42 which serves to deenergize the magnetic switch 45 thus breaking the circuit to deenergize the solenoid 31 allowing the released compression of the spring 35 to return the valve 29 into the position shown in the drawing. The latter shifting of the control valve 29 serves to pass fluid through the pipe l9 to cause the piston I! together with the grinding wheel Ii to move to the extreme right hand end position and at the same time serves to move the piston 89 toward the right to cause the work engaging feeler I to move to an inoperative position out of engagement with the work piece l2.

It will thus be seen that there has been provided by this invention apparatus in which the various objects hereinabove set forth together with many thoroughly practical advantages are successfully achieved. As many possible embodiments may be made of the above invention and as many changes might be made in the embodiment above set forth, it is to be understood that all matter hereinbefore set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

We claim:

1. In a grinding machine having a rotatable grinding wheel, a transversely movable wheel slide therefor, and a feeding mechanism for said slide to feed the slide rapidly toward and from a work piece to be ground, means to slow down the rapid approaching feed to a shoulder grinding feed, means including a work engaging feeler engageable with the work piece to be ground control means movable with said feeler automatically to slow down the shoulder feed to a predetermined body feed when the grinding wheel engages the periphery of the work to be ground, and means to move said feeler to and from an operative position which is operated in timed relation with the wheel feeding mechanism so that the feeler is moved into an operative position in engagement with the work when the wheel is moved toward thework piece.

2. In a grinding machine having arotatable grinding wheel, a transversely movable slide therefor, a feeding mechanism for said slide including a fluid pressure piston and cylinder to feed said slide toward and from a work piece to be ground, means to slow down the rapid apinto operative engagement with the work piece when the wheel is moved toward the work piece to be ground.

3. In a grinding machine having a rotatable grinding wheel, a transversely movable slide therefor, and a feeding mechanism therefor including a fluid pressure piston and cylinder to feed said slide toward and from a work piece to be ground, means including a dash not feed regulator to slow down the rapid approaching feed to a shoulder grinding feed, means including a normally open solenoid valve in the exhaust line of said regulator, a work engaging-feeler engageable with the periphery of the work piece to be ground, means including a normally open limit switch which is movable with said feeler which is arranged when actuated to close said solenoid valve automatically to slow down the infeed to a predetermined body feed when the wheel moves into engagement with the periphery of-the work piece, and means including a detent movable with said feed piston to actuate said limit switch so as to automatically change the rate of infeed when'the grinding wheel engages the work piece to be ground regardless of the initial diameter of the work piece to be ground.

4. In a grinding machine having a rotatable grinding wheel, a transversely movable slide therefor, and a feeding mechanism for said slide including a fluid pressure piston and cylinder to feed said slide toward and from a work piece to be ground, means including a dash pot feed regulator to slow down the rapid approaching feed to a predetermined shoulder grinding feed, a pair of throttle valves to control the exhaust of fluid from said regulator, a normally open solenoid valve between one of said throttle valves and the regulator, means including a work engaging feeler engageable with the periphery of the work piece to be ground, a piston and cylinder to move said feeler to and from an operative position, means including a normally open limit switch which is movable with said feeler piston which is arranged when actuated automatically to close said solenoid valve to slow down the infeed to a predetermined body feed, and means including an adjustable detent which is movable with said feed piston to actuate said limit switch when the grinding wheel moves into engagement with the work piece to be ground so as to automatically change the rate of infeed to a predetermined body feed regardless of the initial size of the work piece to be ground.

5. In a grinding machine having a rotatable grinding wheel, a transversely movable slide therefor, and a feeding mechanism for said slide including a fluid pressure piston and cylinder to feed said slide toward and from a work piece to be ground, means including a dash pot feed regulator to slow down the rapid approaching feed to a predetermined shoulder grinding feed, means including a normally open solenoid valve in the exhaust line of said regulator, means including a normally inoperative work engaging feeler which is engageable with the periphery of the work piece to be ground, a piston andcylinder to move said feeler to and from an operative position, fluid connections between said feed cylinder and said feeler cylinder which is arranged so that fluidunder pressure simultaneously is admitted to the feed and feeler cylinders simultaneously to cause a forward feed of the grinding wheel and a movement of the feeler into operative engagement with the work, means including a normally open limit switch which is movable 9 10 with said Ieeler piston. said switch beta: arranged when actuated to close said solenoid valve REFERENCES automatically to slow down the inteed to a pre- The f lowin r f r n re 0! record in the determined body feed, and means including a: me 01 this P nt: adjustable detent which is movable with so! 5 UNITED TENT teed piston to actuate said limit switch when the STATE? PA 7 s grinding wheel moves into engagement with the Number work piece to be around so as to automatically 1. .511 meal-e Mar. 0, 1934 change the rate 01 infeed to a. predetermined 2,083,748 Steiner June 15, 193'! body speed regardless of the initial size of the 10 $367,391 Dem 23.1941 work piece to be ground. 9,7 6 I'lysere et a1 May 23, 1944 CARL G. FLYGARE. CHARLES C. ALVORD.

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