US2082727A - Grinding machine - Google Patents

Description

June 1, 1937. w. H. WOOD ET AL GRINDING MACHINE Filed April 29, 1936 E m n W W SWY m ME i LP. m5

Pat ented June 1, 1937 PATENT OFFICE aoszazi V GRINDING MACHINE Wallace H. Wood and Carl G. Flygare, Worcester, Mass.,

assignors to Norton Company,

Worcester, Mass., a corporation of Massachusetts i I Application April 29,

8 Claims.

This invention relates to grinding machines, and more particularly to a grinding machine arranged to grind a plurality of faces on a work piece.

5 One object of this invention is to provide a simple thoroughly practical grinding machine for grinding a plurality of faces on a work piece. A further object of this invention is to provide a hydraulically driven grinding machine which is 10 adapted to grind the peripheral and end face of a work piece in a single operation.

It is a further object of this invention to provide an angularly arranged wheel unit with a grinding wheel which is arranged to grind both.

the peripheral and end face of a work piece. It is a furthe object of this invention to provide a grinding m shine in which the grinding wheel is moved to ard and from the work piece to in the structure to be hereinafter described, and

the scope of the application of which will be indicated in the following claims.

30 In the accompanying drawing .in which is shown one of various possible embodiments of the mechanical features off this invention,

Fig. '1 is a combined fr "gmentary plan view, having parts broken away nd shown in section,

35 to more clearly show the construction and a piping and wiring diagram 'to show the operation of the mechanism. Y

A grinding machine has been illustrated in the drawing comprising a base It which is arranged to support a transversely movable wheel slide I I on the usual V-way l2 and flat way l3. The wheel slidell supports a rotatable wheel spindle l4 mounted in bearings (not shown). The wheel spindle l4 supports a grinding wheel 45 I5 on" its outer end. The wheel spindle l4 may be rotated in any well-known manner, such as by means of an electric motor Hi mounted on the upper surface of the wheel slide II. The motor is provided with a rotor shaft II supporting 50 a driving pulley 18 which is connectedby driving belt IS with a pulley 20 mounted on the end of the wheel spindle l4.

The base I also supports a longitudinally movable work supporting table 25 which is ar- 55 ranged to slide longitudinally on the base l0 on a 1936, Serial No. 76,900

V-way 26 and flat way 21. The table 25 carries a headstock 28 and a footstock 29 which are provided with centers 30 and 3| respectively which serve to rotatably support a work piece 32 in operative relation with the grinding'wheel l5. The headstock is provided with a rotatable spindle 33 which is driven by means of a pulley 34 from a well-known source of power, such as a motor on the headstock (not shown) or an overhead drive (not shown). l

The wheel slide H is arranged to be moved transversely toward and from the work supporting table 25. In the preferred construction, a hydraulically operated feeding mechanism is provided comprising a cylinder 40 which is fixed to the base.- The cylinder 40 carries a slidably mounted piston 4| which is connected by a piston; rod 42 with the wheel slide H. A fluid pressure system is provided to supply fluid under pressure to either side of said cylinder to cause a forward .or rearward movement of the grinding wheel I 5. This system comprises a fluid pressure reservoir 43 which is preferably located within the base oi the machine. Fluid is drawn from reservoir 43 through a pipe 44 by means of a geared pump 45 which forces fluid through a pipe 46 to a'feed. controlling valve 41. The feed control valve is preferably a balanced piston type valve comprising a valve stem 48 having formed integrally therewith valve pistons 49, 50, 5i, and 52 which are slidably mounted within the valve casing 41. In the position of the parts, as illustrated in the drawing, fiuid under pressure passing through 4 the pipe 46 enters a valve chamber 53-and passes througha passage 54 into a cylinder chamber 55 to cause the piston 4|, the piston rod 42 and the wheel slide H to move forward so as to cause an infeeding movement of the grinding wheel 15.

During the forward feeding movement, fluid within a cylinder chamber 56 is exhausted' through a passage 51 into a valve chamber 58 which is located between valve pistons 5i and 52 and exhausts through a pipe 59 into the reservoir 43. When the valve is shifted into a reverse position, fluid under pressure from pipe 46 will pass into valve chamber 53 between the valve pistons 50 and 5| and pass through the passage 51 into the cylinder chamber 56 to move the piston 4i and the wheel slide ll rearwardly. A manually operable control lever B0 is plvotally mounted on a stud 6| which is preferably supported on the base ID of the machine.- The lever' 60 is provided with a stud 62 which is connected to the forward end of an extension 63 of the piston rod 48. When the lever 60 is in the position illustrated in full lines inthe drawing.

fluid under pressure will be'admitted to cause a forward feeding movement of the grinding wheel.

When the lever 68 is shifted into dotted line posi- 5 tlon 68a, a rearward movement of the wheel will be obtained.

In order to automatically reverse the valve 81 in timed relationship with the other movements 4 T of the machine parts, an automatic mechanism is provided comprising an electrically operated solenoid 65 which is connected to a projecting arm 66 fixed on the extension 63 of the valve stem 48. When the solenoid I55 is energized, it serves to move the valve rearwardly into the reverse position from that shown in Fig. 1 to cause a rear- .25 closed herein is identical with that shown in the prior United States patent to Sllven No. 2,023,704 dated December 10, 1935. A dash pot piston 18 is slidably mounted on the outer end of the piston rod 42. The dash pot piston I8 is contained within a dash pot cylinder II fixedly mounted on the end of the cylinder 88. A spring 12 serves'to normally hold the dash pot piston in a rearward position. On the forward feeding movement of the grinding wheel, the wheel moves rapidly until an adjustable bushing I8 supported on the outer end of the piston rod 42 engages the dash pot piston I8 which serves to retard the forward motion of the wheel while exhausting fluid through a needle valve 'H. The forward 40 grinding feed continues until a second adjustable bushing 15 engages the end of the dash pot cylinder to positively limit the infeeding movement of the grinding wheel.

In precision grinding it is necessary to allow the wheel to dwell or the sparks to die out with the wheel in contact with the work piece. This is preferably accomplished by means of a dwell control valve 88 which is connected by a pipe llI with achamber 82 which receives exhaust fluid passing outwardly through the needle valve 18: When the dash pot piston' starts its forward movement, exhausting fluid through needle valve 18 and pipe 8|, it causes an upward movement of the piston 82 which serves to rock the lever; pivotally mounted on a'stud 84 in a-clockwise direction. A pivotally mounted trigger 85 rides by the projecting stud 86 for a mercury switch 88. The complete, details of the dwell control valve and its operation have not been illustrated since this valve is not considered part of the present invention. This valve is identical with that shown in the prior United States patent to Wood No. 1,969,997 dated August 14, 1934, to whichreference may be had for a detailed illustration and 5 description of the operation of the dwell control valve. During the forward movement of the dash pct piston I8 while fluid is being exhausted,

prior Patent No. 1,969,997. Fluid exhausts from the dwell control valve 88 through a pipe SI int a sump or reservoir 92. e

During the return or rearward movement of the dash pot piston I8 under the influence of the spring I2, fluid is drawn from the reservoir 92, through a pipe 93, through a ball check valve 94 and a pipe 95. into the dash pot chamber so that the dash pot chamber is filled ready for the next grinding operation.

After the periphery of the work piece has been ground to the desired predetermined size, it is desirable to cause a relativelongitudinal movement between the wheel and work piece to bring .a second operative face of the grinding wheel into bperative relation with a second surface, such as a shoulder, to be ground... In the preferred construction, as illustrated in the drawing, movement is accomplished by providing a similar hydraulic mechanism for moving the work .table 25 longitudinally to move the .work piece 82 into operative relation with the face of the grinding wheel. This hydraulic unit is substantially identical to that above described for moving the wheel slide. A cylinder I88 ismounted on the end of the machine base I8 and carries a piston I8I which is connected. by a piston rod I82 with the end of the table 25. The admission of fluid under pressure ,to the cylinder chambers I83 and I88 is controlled by a reversing control valve I85. This valve is identical with the valve for controlling the transverse movement of the wheel slide and consequently will not be described in detail. The

. valve I85 is'preferably a piston type valve having a valve stem I86. Fluid under pressure is forced from pump 85 through pipe 46 into a'valve chamber I81 and. in the position of the valve as shown in the drawing passes through a passage I88 into the cylinder chamber I83 to cause the table 25 to move toward the right, as viewed in Fig. 1. During this movement of the table, fluid isexhausted from the cylinder chamber I8 through a passage I89, through the valve I85 and out through a pipe 58 which exhausts into the reservoir 43.

The hydraulic system is arranged so that the table 25 will move. rapidly-when moved toward the right to move the work piece 82 through aninoperative position. When the table is moved toward the left to mo the end face II8 of the work piece into 0 tive relation with the operative face III of a ding wheel II2, it is desirable to provide a suitable control unit for precisely regulating the feed to a proper grinding feed. This is accomplished in a manner similar to. that described in connection with the wheel feeding mechanism by means of a dash pot cylinder II5 which is mounted on the end of the cylinder I88 and which contains a dash pot piston H6 which is slidably mounted on the piston rod I82. The details of the dash pot mechanism will not be described, since this dash pot is identical with the dash pot shown on the wheel feeding mechanism. During the movement of the table 25 toward the left, the valve I85 is preferably arranged for either manual or automatic operation. A manually operable control lever I28 is pivotally mounted on a stud III which is supported on the base of the machine. The other end of the lever I28 is connected by a stud I22 with the endof the valve stem I85. When it is desired to cause a feeding movement of the table 25 to move the end face III of the work piece 32 into operative relation with the face III of grinding wheel II 2, the lever I28 is moved into dotted line position I2'8a so that fluid under I pressure from the pipe 45 will pass through passage I09 into cylinder chamber I04 to cause the table to move rapidly toward the left to move the work-into operative position with relation to the grinding wheel 2. The rapid movement of the table toward the left continues until an adjustable sleeve I25 which is mounted on the outer end of the piston rod I02 engages the end of the dash pot piston H8 and causes fluid to exhaust therefrom through a needle valve I26 out through a pipe I21 into a dwell control valve I28-tocause the dwell control valve piston I23 to move upwardly.

The dash pot mechanism, as controlled by the needle valve I26, serves to modify the movements as produced by the pi ton IM to slow down the table movement to a predetermined grinding speed or feed. The infeed toward the left continues until a second sleeve- I30 on the piston rod I02 engages the end of the dash pot cylinder, serving to positively limit'the movement of the table 25 toward the left. when the dash pot piston is prevented from moving further, fiuid under pressure ceases to pass through pipe I 21 and the dwell control valve piston I20 moves downwardly under the influence of gravity, as controlled by a needle valve I32. The flange I33 is connected with the dwell control piston I25 and rocks a pivotally mounted lever I34 in a counterclockwise direction so that the projec tion I35 on the lever engages aproletition I30 on a mercury switch I31 and serves to rock the mercury switch so as to energize a solenoid I40 which is connected to a lever I4I fixedly mounted on the valve stem I05 and shifts the control valve I05 into the position illustrated in Fig. l so as to reverse the fluid 'under'p'ressure and pass it through a passage I08 in thecylinder chamber 'I03 to move the piston II" and the table 25 toward the right to withdraw the face IIO of the work piece 32 away from the operative face 'I II of the grinding wheel II2.

Fluid under pressure is exhausted from the dwell control valve I28, through a pipe I45, into a reservoir I48. During the return movement of, the dash pot piston 'I it under the influence of the spring I", fluid is drawn through a pipe I48, a ball check valve I43 and a pipe I50 into the dash pot chamber so that the chamber is H filled,'ready for the next grinding operation." It is desirable that the relative transverse movement of the grinding wheel and the work support and taken from a source of power, as indicated by the power lines I55. In order that the-wheel feeding movement and the table traversing may be synchronized to operate in the desired sequence, a solenoid I 55 is connected in, parallel with the solenoid 55. The solenoid- I55 is connected through the link' I to actuate the reverse control valve I05 and cause it to move toward the left into a position to cause the table 25 to move the face III! of the work piece 32 into operative relation with the face-I II -of the grinding-wheel II2.- Y

In the operation of this mechanism, the wheel feed and the table operating mechanism have been previously adjusted to produce the desired feed and the stops have been set to stop the infeed and longitudinal movements thereof when the work has been ground to a predetermined extent. The work piece 32 is-mounted on centers '30 and 3I and the headstock pulley 34 is start- 4 ed rotating. The lever 60 is then moved from the dotted line position 80a into the full line position' to move the valve' stem 48 into the position illustrated in the drawing, so that fluid from the pipe 45 passes into the cylinder chamber 55 to cause an infeeding movement of the grinding wheel Ii As above described, the wheel first moves rapidly until the dash pot mechanism is rendered effective to cause a slow grinding feed which continues until the dwell control valve piston 82 drops downwardly under the influence ofgravity to trip the mercury switch 88. Tripping of the mercury switch 88 makes a circuit so as to simultaneously energize the solenoids s5 and use. The energizing of the solenoid 55 serves to remove the'val've 41 into the reverse position to causes.

rearward movement of the grinding wheel. The

face I II of the'grinding wheel II2. This feeding movement continues until the fixed stop I 30 limits the movement of the table toward the left and the dwell control valve piston I 29 drops under; the in-' fluence of gravity to trip the mercury switch I31 which makes a circuit to energize the solenoid I40 which shifts the control valve, I05 toward the right into the position as illustrated in 1 so as to, admit fluid under pressure from the pipe 48 through the passage I08 intothe cylinder chamher I 03 to cause the table 25 to move'toward the right to an inoperative position. v

It' will-thus been seen that there has beenpifovidedby this invent apparatus in whigl i the various objects here nabove set forth together with many thoroughly practical advantages are successfully achieved. As many possible embodimerits 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 ihthe accompanying drawing is to be interpreted as illustrative and not in a limiting sense.

. 1. A grinding machine comprising a base, a

rotatable grinding wheel and a rotatable work support which are arranged to be moved longitud inally and transversely relative to each other, said grinding wheel having a pairof angularly isposed operative faces arranged successively to grind a peripherafsurface and an adjacent shoulderface on the work piece, precision means autofiatically-to cause a relative transverse movement between the wheel and work support to grind the peripheral face on the work piece to a predetermined size, and a second precision means actuated iii relation therewith automatically to move the wheel and table longitudinally relative to each other to grind a shoulder face thereon to a predetermined extent.

2. A grinding machine comprising a base, a

' rotatable grinding wheel and a rotatable work support which are arranged to be moved. longitudinally and transversely relative to each other, said grinding wheel having an operative face arranged to grind a peripheral surface and an end eral face on the work piece to a predetermined size, and means including a fluid pressure op: erated piston and cylinder which are controlled by said regulator and are operatively connected automatically to cause a relative longitudinal movement between the wheel and work support to grind an end or shoulder face on said work piece v to a predetermined extent.

3. A grinding machine comprising a base, a rotatable grindingwheel and a rotatable work support which are arranged to be moved longitudinally and transversely relative to each other, said grinding wheel having a pair of angularly disposed operative peripheral faces arranged to grind a peripheral surface and an end or shoulder face on said work piece, means including a fluid pressure operated piston and cylinder rapidly to move the wheel and work support transversely relative to eachother, a hydraulic feed regulator. associated therewith to control the infeed of the grinding wheel to grind a peripheral face on the work piece to a predetermined extent, electrically operated dwell control mechanism which is' actuated by said regulator when the work piece has been ground to a predetermined size to cause a transverse relative separating movement between the grinding wheel and-the work support, means including a second fluid pressure piston and cylinder which are operatively connected tocause a relative longitudinal movement between the grinding wheel and the work support, and means including a control valve therefor which is actuated by said, dwell control mechanism to control the grinding; of an end orshoulder face on said work piece to a predetermined extent.

' 4. A grinding machine comprising a base, a rotatable grinding wheel, a transversely movable slide supporting said wheel, a longitudinally movable work supporting table, a rotatable work support on said table arranged to rotatably support a work piece, precision means including a fluid pressure piston and cylinder mechanism to feed the wheel slide transversely toward and from the work support to grind a peripheral surface on the work support to a predetermined size, a feed regulator therefor to control therate of said transverse movement, and means including a fluid pressure piston and cylinder controlled by said regulator which are operatively connected to automatically cause a relative longitudinal movement between the wheel and work support to grind an end face thereon to a predetermined extent.

5. A grinding machine comprising a base, a

transversely movable wheel slide thereon, a pair of rotatable grinding wheels suppo'rted on said slide, said grinding wheels-each anoperative face formed thereon, one of wmenisar:

ranged to, grind a peripheral" surface and the other of which is arranged to grind an end-or shoulder face on a work piece, a longitudinally movable work supporting table, means including a fluid pressure operated piston and cylinder to cause a transverse movement of the wheel slide,

to grind a peripheral face on the work piece to j a predetermined size, a hydraulic feed regulator cooperating therewith to control the infeeding movement of the, grinding wheel, means including a fluid pressure operated piston and cylinder,

. and a control valve therefor which isactuated in timed relation with said regulator automatically to move said table longitudinally to bring anend face or shoulder on a work piece into operative relation with the second operative face i on the grinding wheel to grind said surface to a predetermined extents 6. A grinding machine comprising a rotatable grinding wheel, a transversely movable slide therefor, a longitudinally movable work supporting table, a rotatable work support on said table, a fluid pressure piston and cylinder operatively connected to move the slide transversely to cause an infeeding movement of the grinding wheel to grind a peripheral face on the work piece, a dash pot and dwell control mechanism electrically operated means and operatively connected to move the table longitudinally to grind an end face on the work piece to a predetermined extent.

7. A grinding machine comprising a base, a

rotatable grinding wheel and a rotatable worksupport which are arranged to be moved longitudinally and transversely relativeto each other, said grinding wheel -having an operative face arranged to grind a peripheral surface and an end or shoulder face on a work piece, means including afluid pressure operated piston and cylinder to cause a relative transversemovement between the wheel and the work support, a control valve to control the admission and exhaust-of fluid to said piston and cylinder, electrically operated means including a mercury switch actuatedwhen the work piece is reduced to a predetermined size, a solenoid rendered operative by said switch to actuate said valve and cause a transverse separating movement between the wheel and work support, a second fluid pressure piston and cylinder operatively connected to causea-relative longitudinal movement between the wheel and work support to grind an end or shoulder face on the work piece, a control valve for said second piston and cylinder to cause a relative longitudinal movement between the wheel and work in either direction, electrically operated means including a solenoid actuated by saidmercury switch to shift said second control valve to initiate a longitudinal movement between the wheel and work to move a shoulder or end face into operative relation with the face of the grinding wheel to grind the face we predetermined extent, and electrically operated means actuated whensaid face has been ground to a predetermined extent to shift the second control valve and thereby cause a relative longiwork piece from the operative face of the grinding wheel. a

8. A grinding machine comprising a base, a

' transversely movable wheel slide supported Tricia, a.

thereon, a rotatable grinding wheel supported by said slide, said grinding wheel having an operative face arranged to grind a peripheral surinder to move said wheel slide toward and from the work support to grind a peripheral face to a predetermined. size; a dash pot and dwell control mechanism arranged to control the speed of movement of said slide toward the work and to control said grinding operation, a control valve associated with said piston and cylinder, an electrically operated mechanism actuated in timed relation with said dwell control mechanism to actuate said valve and reverse the wheel slide movement alter the peripheral surface has been ground to a predetermined size, means including a second fluid pressure piston and cylinder operatively connected to move said table longitudinally, a dash pot and dwell control mechanism arranged to control the speed of the longitudinal movement of said table in one direction when the table is moved to position an end or shoulder face on a work piece in operative relation with the second face on said grinding wheel, a control valve arranged to control the admission of fluid under pressure to said second cylinder, and electrically operated means including a solenoid actuated in timed relation with said first electrically operated mechanism to shift said second control valve and start the table moving in a predetermined direction to grind a second face on the work piece, and electrically operated means actuated when said shoulder or end face has been ground to a predetermined extent to cause said table to move in the reverse direction to an inoperative position.

CARL G. F'LYGARE. WALLACE H. WOOD.

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