Title:
Grinding machine
United States Patent 2436561


Abstract:
This invention relates to grinding machines, and more particularly to an automatically actuated grinding machine for grinding work pieces, such as the faces of automotive engine valves. One object of the invention is to provide a simple and thoroughly practical automatically actuated and controlled...



Inventors:
Flygare, Carl G.
Fleur, Elphege LA. D.
Silven, Herbert A.
Application Number:
US58409645A
Publication Date:
02/24/1948
Filing Date:
03/22/1945
Assignee:
NORTON CO
Primary Class:
Other Classes:
29/38C, 451/332, 451/339
International Classes:
B24B15/04
View Patent Images:
US Patent References:
2326034Article grinding apparatus1943-08-03
2260843Centerless grinding machine1941-10-28
2229312Fully automatic cylindrical grinding machine1941-01-21
2117917Automatic grinding machine1938-05-17
2113387Valve grinding machine1938-04-05
2110931Machine tool1938-03-15
2109600Grinding machine1938-03-01
2003269Automatic grinding machine1935-05-28
1997551Grinding machine1935-04-09
1779823Automatic cylindrical grinding machine1930-10-28
1017881N/A1912-02-20



Description:

This invention relates to grinding machines, and more particularly to an automatically actuated grinding machine for grinding work pieces, such as the faces of automotive engine valves.

One object of the invention is to provide a simple and thoroughly practical automatically actuated and controlled grinding machine for successively grinding a plurality of work pieces. Another object of the invention is to provide an improved automatic grinding machine with a wheel feeding mechanism which Is arranged first to position the wheel at a rapid rate, then to reduce the rate of movement to a predetermined grinding feed, and a positive stop to limit the infeeding movement of the grinding wheel, combined with an electrically controlled timing mechanism which allows the wheel to spark out or finish grind the work, after which the wheel is automatically moved to an inoperative position.

Another object of the invention is to provide a hydraulically operated feeding mechanism including a piston and cylinder to facilitate a rapid positioning of the grinding wheel, a dash pot mechanism to reduce the rate of movement of the grinding wheel to a predetermined grinding feed as the wheel engages the work, a positive stop to limit the infeeding movement of the grinding wheel, and an electrically operated timer mechanism to allow the wheel to spark out for a predetermined time interval, after which the wheel is hydraulically moved rapidly to a rearward or inoperative position.

Another object of the invention is to provide an automatically actuated work loading mechanism including a rotatable turret for automatically positioning successive work pieces in operative relation with a work supporting collet. Another object of the invention is to provide such a machine with an automatically actuated pusher and ejector mechanism for pushing a work piece axially into position within said work collet and for ejecting a finish ground work piece therefrom after a grinding operation.

A further object of the invention is to provide a collet actuating mechanism which is spring actuated to close the collet to grip a work piece for a grinding operation and a hydraulically operated mechanism to release said collet after the work piece has been ground to the predetermined extent. A further object of the invention is to provide a turret actuating mechanism which is operated in timed relation with the collet actuating and pusher and ejecting mechanism so that after a ground work piece has been ejected from said collet, the work turret will be automatically indexed to present the next work piece into an operative position. 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 exemplified in the structure to be hereinafter described, and the scope of the application of which will be indicated in the following claims.

In the accompanying drawings in which is shown one of various possible embodiments of the mechanical features of this invention, Fig. 1 is a front elevation of the improved automatic grinding machine; Fig. 2 is a right-hand end elevation of the machine shown in Fig. 1; Fig. 3 is a plan view of the automatic grinding machine; Fig. 4 is a fragmentary plan view, partly in section, on an enlarged scale, showing a fragment of the work loading turret and the work chucking mechanism; Fig. 5 is a fragmentary side elevation, on an enlarged scale, of the work loading turret and work support; Fig. 6 is a combined fragmentary cross-sectional view through the grinding wheel feeding mechanism combined with an electrical wiring and piping diagram of the feed controlling mechanism; and Fig. 7 is a fragmentary combined hydraulic piping and electrical wiring diagram of the control mechanism for the work loading and supporting apparatus.

A grinding machine has been illustrated in the drawings comprising a base 10 which serves as a support for a transversely movable wheel slide II. The wheel slide II is slidably supported on the usual V-way and flat way (not shown) on the base 10. The wheel slide II supports a rotatable grinding wheel 1.2 which is mounted on one end of a rotatable wheel spindle 13. The wheel spindle 13 may be driven by any of the well known mechanisms, such as an overhead belt drive or an electric motor 14 which is mounted on the upper surface of the wheel slide II. As illustrated, a wheel driving pulley 15 is mounted on the opposite end of the wheel spindle 13 and is connected by a driving belt 16 with a pulley 17 which is mounted on an armature shaft 18 of the motor 14.

Work head The base 10 also supports a work rotating and work loading mechanism comprising a rotatably mounted work spindle 20 which is rotatably supported in a work head 21. The work head 21 may be either fixed or adjustably positioned on the base 10 so that the axis of the work spindle 20 may be adjusted relative to the axis of the grinding wheel if desired so that either a true cylindr:cal face may be ground on the work piece or a frusto-conical shape may be ground, if desired. The sp'ndle 20 serves as a support for a work collet 22 which is arranged to be c'osed by means of a compression spring 23 (Fig. 7). A I hydraulically actuated mechanism is provided for releasing the collet 22 to facilitate ejection of a ground work piece therefrom after a grinding operation has been completed. This mechanism comprises a cylinder 24 which is supported on the work head 21. The cylinder 24 contains a piston 25 which is provided with an integral piston rod 26 arranged in axial alignment with the co'let actuating sleeve contained within the spindle 20. 2 This improved grinding machine, as shown in the drawings, is illustrated as being set up for automatically grinding a frusto-conical face 26 on an automotive valve 27. A work pushing and ejecting mechanism is provided comprising a pusher arm 28 and an ejector arm 29 which are mounted on the right-hand end of a piston rod 30. A hydraulically actuated mechanism is provided for controlling the movement cf said pusher arm 28 and the ejector arm 29 comprising a cylinder 31 which is mounted on the work head 21. The cylinder 31 contains a piston 32 which is fixedly mounted on one end of the piston rod 30.

Work turret An automatic work loading mechanism is provided for automatically and successively conveying work pieces into axial alignment with the work supporting and rotating collet 22. As illustrated in the drawings, this work turret may comprise a pair of spaced disks 35 and 36 which are fixedly supported on a rotatable shaft or spindle 37. The periphery of each disk 35 and 36 is provided with aligned work receiving notches or apertures 37 and 38, respectively. Spring clips 39 are provided on the disk 36 for holding the work pieces 27 in position within the notches 31 and 38 in the work turret disks 35 and 36 respectively.

The work pieces 27 are manually loaded into the notches 37 and 38 by the operator.

A pawl and ratchet mechanism is provided for automatically actuating the work turret so that after a work piece 27 has been ejected from the collet 22, the shaft or spindle 31 supporting the work turret disks 35 and 36 may be automatically indexed to convey the next work piece 27 into operative relation in alignment with the collet 22. This mechanism may comprise a ratchet wheel 40 which is fixedly mounted relative to the shaft or spindle 31. A pawl 41 is provided for coacting with the ratchet wheel 40. The pawl 41 is pivotally connected by means of a stud 42 with a spring-pressed member 43 which is slidably supported in a member 44. The member 44 is fixedly mounted on the right-hand end of a piston rod 45 (Fig. 7).

A hydraulically operated mechanism is provided for actuating the pawl 41 comprising a cylinder 46 which is supported on the work head 21. The cylinder 46 contains a slidably mounted piston 47 which is connected to or fixedly mounted on the left-hand end of the piston rod 45. A compression spring 48 is provided for moving the piston 47 in a direction toward the left (Fig. 7) to move the pawl 41 through its idle stroke.

When fluid under pressure is passed through a pipe 49 into a cylinder chamber 50, the piston 47 together with the associated parts and the pawl 41 will be moved toward the right to index the 6 work turret to present the next work piece 21 into axial alignment with the collet 22.

Wheel feed A wheel feeding mechanism is provided for 0 feeding the grinding wheel 12 toward and from ,the work piece to be ground. This mechanism may comprise a half nu' 55 depending from the under side of the wheel slide 11. The half nut 55 meshes with or engages a rotatable cross feed .6 screw 56. The cross feed screw 56 may be manually rotated by a manually operable feed mechanism such as, for example, a manually operable feed wheel 57 which is supported on the upper portion of the wheel slide II (Figs. 1 and !0 2). If desired, however, the feed screw 56 may be rotated in the conventional manner by means of a manually operable feed wheel 58 shown diagrammatically in Fig. 6 of the drawings. The right-hand end of the feed screw 56 is journalled in a slidably mounted sleeve 59 which is slidably mounted within a housing 60 fixed relative to the base 10. A hydraulically operated feed mechanism is provided for feeding the feed screw 56 and the wheel slide II rapidly to position the grinding wheel relative to the work piece to be ground. This mechanism may comprise a hydraulic cylinder 61 fixed relative to the base 10 which contains a slidably mounted piston 62.

The piston 62 is fixedly mounted on a piston 36 rod 63, the left-hand end of which is connected with the slidably mounted sleeve 59. It will be readily apparent that when fluid under pressure is admitted through a pipe 64 Into a cylinder chamber 65 at the right-hand end of the piston 62, the piston 62 together with the feed screw 56 and the wheel slide II will be moved toward the work piece. During this forward movement of the grinding wheel 12. fluid within a cylinder chamber 66 may exhaust through a pipe 67.

A feed control valve 10 is provided for controlling the flow of fluid under pressure to and from the cylinder 61. This valve comprises a valve stem 71 having formed integrally therewith valve pistons 72, 73, 14 and 75. The valve stem 1 is arranged so that it may be electrically actuated in timed relation with the other mechanisms of the machine. This actuating mechanism comprises an electric solenoid 16 .mounted adjacent to and operatively connected " to the left-hand end of the valve stem 71 and an electric solenoid 77 mounted adjacent to and operatively connected to the right-hand end of the valve stem 11'.

In the position of the valve 70 as shown in Fig. 6, fluid is pumped from a reservoir 80 through a pipe 81 by means of a motor driven geared pump 82. The pump 82 forces fluid under pressure through a pipe 83. A pressure relief 15 valve 84 is connected by a pipe 85 with the pipe line 83 to facilitate maintaining the desired operating pressure within the hydraulically operated system. Fluid under pressure passing through the pipe 83 enters a valve chamber located between the valve pistons 73 and 74 and passes 70 through the pipe 61 into the cylinder chamber 66 to move the piston 62 into a rearward position, thus moving the grinding wheel 12 into its rearward or inoperative position. The valve stem 71 Sis shifted into the position illustrated in Fig. 6 by energization of the solenoid 11. While the valve parts are in the position illustrated, fluid under pressure within the cylinder chamber 65 may exhaust through the pipe 64, a valve chamber located between the valve pistons 12 and 13, and out through an exhaust pipe 86 into the reservoir 80.

When it is desired to initiate an infeeding movement of the grinding wheel 12, the solenoid 76 is energized to shift the valve stem 11 toward the left (Fig. 6). This movement serves to pass fluid under pressure from the pipe 83 through the valve chamber located between the valve pistons 73 and 74, and through the pipe 64 into the cylinder chamber 65 to cause the piston 62, the feed screw 56, and the wheel slide II to move toward the left (Fig. 6) to cause the grinding wheel 12 to approach the work piece to be ground.

A suitable fluid pressure control or feed regulating mechanism is provided for modifying the rapid approaching movement caused by the piston 62 to obtain a controlled predetermined grinding feed of the grinding wheel 12. A selfcontained dash pot feed regulator 90 is provided having a pair of spaced dash pot cylinders which Scontain slidably mounted dash pot pistons 91 and 92. The dash pot pistons 91 and 92 and their respective cylinders are arranged with their axes parallel to each other and spaced on diametrically opposite sides of the axis of the piston rod 63. The dash pot pistons 91 and 92 are normally held in a rearward (right-hand) position by means of compression springs. An adjustable stop screw 93 serves to limit the rearward movement of the dash pot pistons 91 and 92, respectively. A slidable sleeve 94 is supported on the rear extension of the piston rod 63. The sleeve 94 has a flanged portion 95 which is either formed integral therewith or fixedly secured thereto. The flange 95 is arranged to engage the right-hand end faces of the dash pot pistons 91 and 92, respectively. The stop screw 93 engages the flange 95 and thereby serves to limit the rearward movement of both dash pot pistons 91 and 92 toward the right (Fig. 6).

The rapid feeding movement of the grinding wheel 12 and wheel slide I I continues intil an adjustable nut 96 on a threaded portion 97 of the rearward extension of the piston rod 63 engages the right-hand end of the sleeve 94. Continued movement of the piston rod 63 moves the sleeve 94 and the flange 95 toward the left and continued movement serves to move the dash pot pistons 91 and 92 in a direction toward the left (Fig. 6). When the flange 95 engages the ends of the dash pot pistons 91 and 92, respectively, the rapid approaching or feeding movement of the grinding wheel 12 toward the work piece 27 as produced by the piston 62 is reduced to a slower predetermined grinding feed due to the fact that fluid confined within the dash pot cylinders which are interconnected exhausts through a passage 98, a needle valve 99, through a pipe 100, into a reservoir 101. By adjusting the aperture of the needle valve 99, a desired and predetermined infeeding movement of the grinding wheel may be obtained.

When fluid under pressure is admitted to the cylinder chamber 66 to cause a rearward movement of the piston 62, the sleeve 94 together with the flange 95 is moved rearwardly by means of the released compression of the springs within the dash pot cylinders which returns the dash pot pistons 91 and 92, respectively, to their rearward positions and moves the flange 95 into engagement with the stop screw 93. During the rearward movement of the dash pot pistons 91 and 92, a suction is created within the dash pot cylinders which serves to draw fluid from the reservoir 101, through a pipe 102, and a ball check valve 103, to fill the dash pot cylinders for the next infeeding movement of the grinding wheel 12. During the infeeding movement of the dash pot pistons 91 and 92, fluid within the dash pot cylinders serves to hold the ball cheek valve 103 closed so that fluid within the dash pot cylinders Is forced out through the passage 98 and the needle valve 99 and also through a throttle valve 104 until the passage 98 is closed, into the reservoir 101 to control the rate of infeeding move16 ment, as desired.

The adjustable throttle valve 104 is connected between the pipe 102 and a chamber 106 to facilitate exhaust of fluid from the dash pot cylinders after the passage 98 is closed by the dash pot piston 91. If desired, the throttle valve 104 may be used to give a very final feeding movement of the grinding wheel 12 just prior to a positive stop collar 107 engaging a stop surface formed on the rear end of the dash pot feed regulator unit which 26 positively limits the advance of the grinding wheel 12 toward the work axis. In the latter case, two distinct grinding feeds of the grinding wheel 12 may be obtained, by manipulation of the needle valve 99 combined with the opening of the throttle valve 104 which would continue until the passage 98 is cut off, after which the feeding movement is reduced to a very slow infeeding controlled by the throttle valve 104.

In order to maintain the desired quantity of fluid in the reservoir 101, initially to fill the feed regulator system and thereafter to replenish leakage from the feed regulator system, a pipe 108 is connected to the pressure pipe 83 to pass fluid to the reservoir 101. A valve 109 is provided in the pipe line 108 which may be readily opened to allow the desired amount of fluid from the pump 82 to pass into the reservoir 101, after which the valve 109 may again be closed.

It is desirable that a continuous cycle, namely, a continuous in-and-out movement of the grinding wheel 12, be obtained so that after one work piece 27 has been ground to the desired and predetermined size, the grinding wheel 12 will move rearwardly to an inoperative position to facilitate 5o loading of the next work piece 27 into the machine. After the next work piece 27 has been loaded in position, the wheel slide II is automatically started on the next grinding cycle. An electrical control system is provided for controlling automatically the grinding cycle of the wheel 12. A normally closed limit switch 115 is mounted on the rear surface of the dash pot feed regulator casing 90. This limit switch 115 is arranged to be actuated by a micrometer adjusting screw 116 6o carried by the positive stop collar 107. A normally open limit switch 117 is mounted on the base of the machine at the rear of the wheel slide II and is arranged to be actuated by an abutment 118 projecting from the rear portion of the wheel slide II. A time delay relay 119 is provided which may be a standard electrically operated adjustable time delay relay, such as that known as the "Microflex" instantaneous reset timer manufactured by the Eagle Signal Corporation of Moline, Illinois. The Microflex timer is a synchronous motor operated time delay relay and consists of a clutch-operating mechanism and a motor and gear train assembly, with an electromagnetically operated clutch for coupling 76 them together. It is entirely automatic in action and requires only the closing or opening of the timer control circuit to initiate a cycle of operation. Power is supplied from power lines 120 (Fig. 6). A stop button stop switch 121 and a push button starter switch 122 are mounted in the front of the machine base. A pivotally mounted manually operated control lever 123 is supported on the front of the machine base 10 and is arranged to actuate either the stop switch 121 or the starter switch 122. An electrically operated relay 124 is connected with the starter switch 122. An electrically operated relay 124 is connected with the starter switch 122 so that when the starter switch 122 is closed, the electromagnet of the relay 124 will be energized to start a grinding cycle. A snap switch 125 is provided for rendering the electric time delay relay 119 inoperative if and when desired so that the wheel feeding movement may be manually controlled by actuation of the control lever 123. A snap switch 126 is provided which may be manually operated to open a circuit so as to deenergize the solenoid 17 when the machine is idle.

When it is desired to start a grinding cycle, the control lever 123 is rocked in a counterclockwise direction (Fig. 6) to actuate and close the starter switch 122 which closes a circuit, thus energizing the relay 124 which serves to close a circuit and energize the solenoid 76 so as to shift the valve stem 71 toward the left (Fig. 6) so that fluid under pressure from the pump 82 passing through the pipe 83 will be conveyed to the cylinder chamber 65 to initiate a forward feeding movement of the grinding wheel 12. The grinding wheel 12 moves rapidly toward the work axis until the wheel approaches the surface of the work to be ground, at which point the nuts 96 engage the sleeve 94 and thus render the dash pot feed regulating mechanism operative to reduce the rapid approaching movement to a slower uniform grinding feed of the wheel 12. The grinding feed continues until the positive stop collar 101 engages the positive stop surface at the rear of the dash pot cylinder casing 90. At the same time, the micrometer adjusting screw 116 engages and actuates the normally closed limit switch 115 to open the same, thus breaking a circuit to set the electric time delay relay 119 in motion. The grinding wheel 12 remains in grinding engagement with the work for a sparking-out or finish grinding period for a definite time interval as governed by the time delay relay 119. After the predetermined time interval has elapsed, the time relay 119 closes a circuit to energize the solenoid 77 so as to shift the valve stem 71 toward the right (Fig. 6) into the position illustrated so that fluid under pressure from the pump 82 and pressure pipe 83 will pass into the cylinder chamber 66 to cause a rapid rearward movement of the grinding wheel 12 and its supporting wheel slide SI. The rapid rearward movement of the slide continues until the lug 118 on the rear of the wheel slide engages and actuates the normally open limit switch 17 to close the same and thus close a circuit again to energize the solenoid 76 to initiate a forward feeding movement of the grinding wheel 12 and its supporting slide. It will thus be seen that the cycle of movement of the wheel slide toward and from the work will continue automatically until it is stopped by the operator. In order to break the circuit and thus stop the cycle of movement of'the grinding wheel 12 and its supporting slide I, the control lever 123 may be swung in a clockwise direction (Fig. 6) to actuate the stop switch 121 to break the circuit and thus deenergize the electromagnet in the relay 124 which renders the electrical control for the wheel slide inoperative and thus maintains the grinding wheel in a stopped position.

a A diagrammatic illustration of the control mechanism for the work loading, supporting and rotating mechanism is shown in Fig. 7. Fluid under pressure passing through the pipe 83 passes through a pipe 130 to a solenoid actuated valve 131 which is actuated by a solenoid 132. The valve 131 is a standard well known three-way solenoid operated valve, such as that manufactured by Vickers Inc. of Detroit, Michigan. The valve 131 is connected by a pipe 133 with a cyl1i inder chamber 134 in the cylinder 24 which controls the releasing of the work gripping collet 22. When the valve 131 is opened, fluid under pressure passing through the pipe 133 enters the cylinder chamber 134 to move the piston 25 toward the right (Fig. 7). When the piston 25 reaches the position illustrated, the collet 22 is moved a sufficient distance to release the work piece therefrom. In this position of the piston 25, fluid under pressure in the cylinder chamber 134 may by-pass through a pipe 135 to a threeway solenoid operated valve 136 which is actuated by a solenoid 137. Fluid under pressure passing through the pipe 135 into the valve 136 may normally pass through a pipe 138 and a pipe 139 into a cylinder chamber 140 in the cylinder 31 to move the piston 32 toward the right so that the ejector arm 29 will also move toward the right to move the work piece such as the valve 27 axially out of engagement with the collet 22. After the piston 32 reaches the position illustrated in Fig. 7, fluid under pressure in the cylinder chamber 140 may by-pass through a pipe 141 and the pipe 49 into the cylinder chamber 50 to move the piston 47 toward the right (Fig. 7) which moves the pawl 41 toward the right to rotate the ratchet wheel 40 so as to index the next work piece 21 into an operative position in axial alignment with the collet 22. As the pawl 41 moves toward the right, a cam 143 carried by the member 44 actuates the normally open limit switch 144 to close a circuit and thus energize the solenoid 131 which serves to open a three-way valve 142 so that fluid under pressure in the pipe 83 may pass through the valve 142 and through a pipe 145 into a cylinder chamber 146 in the cylinder 31 to move the piston 32 toward the left so that the pusher 28 will engage the end of the valve 27 to be ground and push it axially toward the left into operative engagement with the collet 22. At the same time, when the solenoid 137 is energized, the valve 136 is actuated so that fluid in the cylinder chamber 140 may exhaust through the pipe 139, the pipe 138, the valve 136 and return through a pipe 148 to the reservoir 80.

It is desirable that the chucking and turret actuation take place during the rearward movement of the grinding wheel 12 after a work piece 27 has been ground to the predetermined extent. A pair of power wires 150 are cut into the power lines 120 inside the fuses, as illustrated in Fig. 6, to convey current to the electrical circuit shown in Fig. 7. A snap switch 152 is connected in one of the power lines 150 by means of which the electrical circuit shown in Fig. 2 may be rendered operative or inoperative, as desired. A normally open limit switch 153 is mounted on the machine base and has an actuating roller in the path of an adjustably mounted cam 154 which is carried by the wheel slide 11. When the wheel slide II moves rearwardly, the cam 154 engages the actuating roller of the limit switch 153 to close the limit switch 153 and thereby energize the solenoid 132, thus opening the valve 131 to pass fluid through the pipe 133 to release the collet 22, after which fluid may pass thrcugh the pipe 133 to re- I lease the collet 22, after which fluid may pass through the pipe 135 and the valve 138, through the pipes 138 and 139, into cylinder 31, to actuate the ejector arm 29 to eject the work piece 27 from the collet 22. After the work piece has been 1 ejected from the collet 22, fluid under pressure may by-pass through the pipes 141 and 49, into the cylinder 48, to move the pawl 41 toward the right so as to move the ratchet wheel 40 in a counterclockwise direction (Fig. 7).

During the actuating movement of the pawl 4 1, the cam 143 engages the actuating roller of the normally open limit switch 144 to close the limit switch 144 and thereby energize the solenoid 137.

Energization of the solenoid 137 serves to open 2 the valve 142 so that fluid under pressure may pass through the pipe 145 into the cylinder chamber 146 so as to move the pusher arm 28 toward the left (Fig. 7) to push the next work piece 27 into operative engagement with the collet 22. When the wheel slide I I starts its next forward movement, the forward movement of the cam 154 allows the normally open limit switch 153 to open, thus breaking the circuit to deenergize the solenoid 132 so that fluid under pressure passing through the pipe 130 is cut off by the valve 131 and fluid under pressure within the cylinder chamber 134 may exhaust through the pipe 133, the valve 31, and a pipe 155 into the reservoir.

This cycle of operation is repeated on each successive rearward movement of the wheel slide i so that when the wheel slide I1 starts its next forward movement, a new piece of work, such as a valve 27, is positioned in operative relation with the collet 22.

It may be desirable to provide means whereby both the electrically controlled hydraulic wheel feeding mechanism and also the electrically controlled hydraulically operated work loading, chucking and rotating mechanism may be rendered inoperative so that the machine may be manually controlled. In order to accomplish this result, a snap switch 151 is located in one of the power lines 120 inside the fuse so that when the switch is snapped to an off position, the power is cut off from the auxiliary feed wires 150 which control the work loading, chucking and rotating mechanism and also from the grinding wheel feed controlling mechanism. 'As above described, each circuit is provided with an independent switch whereby either the automatic cyclic wheel feed may be rendered inoperative or the work loading, chucking and rotating mechanism may be rendered inoperative. The snap switch 125 is provided whereby the timer I 9 may be cut out and rendered inoperative, thus facilitating a manual control of the hydraulic feed mechanism by means of the lever 123, the stop switch 121 and the start switch 122. Similarly, the snap switch 152 is provided in the electrical circuit for controlling the work loading, chucking and rotating mechanism whereby this mechanism may be similarly cut off independently of the wheel feed.

The exhausting of fluid from the cylinder chamber 134 releases the compression of the spring 23 which serves to close the collet 22 and thus grip the work piece 27 so as to rotate the same during the next grinding operation.

In order to rotate the work piece 27 during a grinding operation, an electric motor 160 is mounted on the upper portion of the work head 21. The motor 160 is connected by means of a driving bclt contained within a belt housing or casing 161 (Fig. 3). The belt drive contained Swithin the casing 161 is operatively connected to rotate the.sleeve 20 (Fig. 4) so as to rotate the collet 22 and thereby rotate the work piece 27 during a grinding operation.

In order to steady and support the work piece 0 during a grinding operation, a roller type rest is prov'dcd comprising a pair of spaced rotatable rollers 164 and 165 which are rotatably supported by a bracket 166 (Fig. 5). The bracket 166 is arranged so that it may be adjusted vertically 8 by means of an adjusting screw 167 and may be clamped in adjusted position by means of clamping screws 168 and 169. The rollers 164 and 165 are preferably adjusted so that a work piece 27 supported thereby is axially aligned with the 0 axis of the work collet 22. The rollers 164 and 165 are preferably located between the plates 35 and 36 of the work loading turret. A third work supporting and steadying roller 170 is rotatably supported at the lower end of an arm 1 1I. The arm 171 is pivotally supported on a stud 172.

The stud 172 also supports an arm 173. The arms 173 and 171 are preferably pinned to the stud 112 so that they serve as a bell-crank lever to actuate and support the roller 170. The bellcrank lever 171-173 is normally urged in a clockwise direction by means of a tension spring 174 which is connected between a stud 175 on the arm 173 and a stud 176 which is fixed relative to the base of the machine. A stop pin 177 serves normally to limit the rocking movement of the bell-crank lever 17-173 in a clockwise direction.

It will be readily apparent from the foregoing disclosure that when the work loading turret disks 35 and 36 move to position a work piece 27 in an operative position, the work piece 27 engaging the roller 170 will rock the bell crank lever 171-173 against the tension of the spring 174 until the work piece 27 rides into engagement with the rollers 164 and 165. After the work piece 27 has been clamped in position in the work driving collet 22, the rollers 164, 165 and 170 serve to steady and support the work piece 27 during a grinding operation while the 60 grinding wheel 12 grinds the face 26 on the valve 27.

The finish ground work pieces 27 are ejected from the turret wheel by means of a pair of guides 180 and 181 which project upwardly between the turret plates 35 and 36. The guides 180 and 181 are arranged in the path of the valve stem 27 so that as'the turret wheel is successively indexed, the finish ground valve 27 will be pulled out of the pockets 37 and 38 and the spring clips 39. The finish ground work pieces then drop onto a continuously rotated conveyor belt 182 and may be dropped into a receptacle (not shown) at the sides of the machine base.

The operation of this improved grinding machine will be readily apparent from the foregoing disclosure. Assuming all of the adjustments have been previously made, the wheel drive motor 14 and work drive motor 160 are set in motion.

The work pieces 27 are then manually placed in position on the turret wheel 35-36 and the tur'ret is rotated manually to position the first work piece 27 into engagement with the supporting and steadying rollers 164, 165 and 170 in axial alignment with the collet 22. The control lever 70 123 is then rocked in a counterclockwise direction to close the push button switch 122 which serves to energize the relay 125. Energization of the relay 124 closes a circuit to energize the solenoid 76 which shifts the valve stem 71 toward the left (Fig. 6) to initiate a forward movement of the grinding wheel. The forward movement of the grinding wheel starts at a rapid approaching rate until the nut 16 on the piston rod 63 engages the sleeve 94, after which the dash pot pistons 91 and 92 reduce the movement of the piston- 62 to a predetermined grinding feed. The grinding feed continues until the positive stop collar 107 engages the stop surface formed on the rear face of the dash pot unit 90. At this time the micrometer adjusting screw 116 engages and actuates the normally closed limit switch 115 to set the electric time delay relay 119 in motion. The time relay allows the grinding wheel to remain in grinding contact with the work piece for a predetermined time interval to allow the wheel to spark-out or finish-grind the work piece. After the predetermined time interval has elapsed, the relay 119 energizes the solenoid 77 to shift the valve stem 71 into the position illustrated in Fig. 6 so as to cause a rearward movement of the wheel slide II and grinding wheel 12.

When the grinding wheel slide reaches its rearmost position, the abutment 118 on the rear of the wheel slide 1 engages and actuates the normally open limit switch 117 to close the same, thereby closing a circuit again to energize the solenoid 76 to shift the valve stem 71 so as to start a forward feeding movement of the wheel slide II and grinding wheel 12 for the next grinding cycle. The above described grinding cycle operates continuously unless stopped by the operator. In case it is desired to interrupt the grinding cycle, the manually operable lever 123 may be rocked in a clockwise direction to actuate the stop switch 121 which breaks the circuit, thus deenergizing 'the relay 124 which immediately causes the wheel slide to move rearward'y to an inoperative position.

The automatically operated work loading mechanism is actuated by the rearward movement of the wheel slide II. The adjustably positioned cam 154 engages and actuates the normally open limit switch 153 during the rearward movement of the wheel slide II to close a circuit and thereby energize the solenoid 132 which opens the three-way valve 131 so as to allow fluid under pressure from the pump 82 passing through the pipe 83 to pass through the pipe 130 and through the pipe 131 into the chamber 134 to release the collet 22. After the collet has been released, fluid under pressure in the cylinder chamber 134 passes through the pipe 135, the valve 136, the pipe 138, the pipe 139, into the cylinder chamber 140 to move the piston 32 toward the right (Fig. 7) to shift the ejector 20 also toward the right to eject the work piece 27 from engagement with the collet 22. After the work has been ejected, fluid under pressure in the cylinder chamber 140 may pass through the pipe 141 and the pipe 149 into the cylinder chamber 50 to actuate the pawl 41 and thereby index the turret wheel 35-36 to move the finish ground work piece out of axial alignment with the collet and to present the next work piece in alignment therewith.

During the actuating movement of the pawl 41, the cam 143 engages and actuates the normally open limit switch 144 which serves to energize the solenoid 137 to shift the three-way valve 136 so as to allow fluid to exhaust from the chamber 140 and at the same time shifts the threeway valve 142 to allow fluid under pressure in the pipe 83 to pass through the pipe 145 into the cylinder chamber 146 to move the piston 32 and pusher arm 28 toward the left (Fig. 7) to push the next work piece 27 into operative engagement with the collet 22. When the wheel slide moves forward and the cam rides out of contact with the limit switch 153, the switch 153 opens, thus deenergizing the solenoid 132 which allows the valve 131 to shift so that fluid in the cylinder chamber 134 may exhaust therefrom, thus releasing the compression of the spring 23 which serves to close the collet 22 so as to grip and rotate the work piece for the next grinding operation. The above cycle of operation of the work loading. ejecting, pushing and indexing mechanism operates during each rearward movement of the wheel slide so as automatically to remove a ground work piece from the collet and present a new work piece to be ground.

It will thus be seen that there has been provided by this invention apparatus in which the 28 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 means including a rotatable chuck to support and rotate a work piece, a rotatable grinding wheel, a transversely movable slide therefor, a wheel feeding mechanism automatically to feed said slide toward and from the work piece to grind the same to a predetermined size, and a work loading mechanism including a rotatable turret to convey successive work pieces into axial alignment with said chuck, a hydraulically operated pusher to move a work piece supported by said turret into operative relation with said chuck before a grinding operation, and means including an automatically actuated ejector to eject finish ground work pieces from said chuck after a grinding operation has been completed.

2. In a grinding machine having a rotatable work supporting chuck, a rotatable grinding wheel, a transversely movable slide therefor, an automatic continuously operated feeding mechanism including a hydraulic piston and cylinder to feed said wheel slide transversely toward and from the axis of the work chuck successively to grind a plurality of work pieces to a predetermined size, a control valve for said cylinder, means to shift said valve to cause an infeed of said grinding wheel, an electric time delay relay to control the duration of the finish grinding, said time relay serving after a predetermined time interval to shift the control valve so as to cause a rearward movement of the slide, and means including a limit switch which is actuated by said wheel slide each time it reaches a rearward position automatically to initiate another grinding cycle.

3. In a grinding machine having a rotatable work support including a work chuck, a rotatable grinding wheel, a transversely movable slide therefor, an automatic continuously operated feeding mechanism including a hydraulic piston and cylinder to feed said wheel slide transversely toward and from the axis of the work chuck successively to grind a plurality of work pieces to a predetermined size, a control valve for said cylinder, a solenoid to shift said valve in either direction, means to energize one of said cylinders to initiate a forward feeding movement of the grinding wheel, an electric time delay relay set in motion by said forward movement to control the duration of the finish grinding, said relay serving after a predetermined time interval to shift said control valve to cause a rearward movement of the grinding wheel, and means including a limit switch which is actuated by said wheel slide each time it reaches a rearward position automatically to initiate another grinding cycle.

4. In a grinding machine having a rotatable work support including a work chuck, a rotatable grinding wheel, a transversely movable wheel slide therefor, an automatically actuated continuously operated feeding mechanism to feed said slide transversely toward and from the axis of said work chuck successively to grind a plurality of work pieces to a predetermined size, means including a limit switch which is actuated by said wheel slide each time it reaches a rearward position automatically to initiate another grinding cycle, a work loading mechanism including a rotatable work turret to convey successive work pieces to and from said chuck, and means including a limit switch which is actuated during each rearward movement of said wheel slide to initiate a loading cycle.

5. In a grinding machine having a rotatable transversely movable grinding wheel, a rotatable work chuck, a compression spring to close said chuck, a hydraulic piston and cylinder to release said chuck, a work ejector to eject a ground work piece from said chuck, a piston and cylinder to actuate said ejector, said ejector cylinder being connected in series with the chuck releasing cylinder so that after the chuck has been released, fluid may by-pass from the chuck cylinder into the ejector cylinder so as to eject a ground work piece from said chuck, a rotatable work loading turret successively to convey work pieces to and from an operative position relative to said chuck, and means including a piston and cylinder to index said turret, said turret actuating cylinder being connected in series with said ejector cylinder so that after the ejector has moved to eject a work piece from said chuck, fluid under pressure from the ejector cylinder may by-pass into said turret cylinder to index the work turret.

6. In a grinding machine having a rotatabl grinding wheel, a transversely movable slide therefor, a wheel feeding mechanism automatically to feed said slide first at a rapid positioning rate, then at a predetermined feeding rate and a positive stop for limiting the forwar movement of said slide, an electric time dela relay to allow the grinding wheel to spark-ou for a predetermined time interval, a rotatabl work supporting and rotating collet, a rotatable work loading turret automatically to conve successive work pieces to and from an operativi position relative to said collet, a work pushe and ejector automatically to push a work piec into said collet before a grinding operation anm to eject a work piece therefrom after a grindin; operation, and a limit switch which is actuatec by the rearward movement of the wheel slid to release said collet, to eject the ground worl piece therefrom, to index said turret to conve the ground work piece to an inoperative positior and to present the next work piece in an oper ative position relative to said collet and to push said work piece axially into said collet ready for the next grinding cycle before the grinding wheel slide starts its next forward movement.

7. In a grinding machine having a rotatable grinding wheel, a transversely movable wheel slide therefor, a wheel feeding mechanism for said slide comprising a hydraulic piston and cylinder to move said slide, a dash pot feed regulator, a control valve for said cylinder, a solenoid to shift said valve in either direction, a start and stop switch, an electric relay actuated thereby, said relay serving to energize said solenoid to shift the control valve so as to initiate an infeeding movement of the grinding wheel, an electric time delay relay to control the spark-out period, a limit switch actuated by and in timed relation with the forward feeding movement of said slide to set said timer in motion, said timer serving after a predetermined time interval to energize a second solenoid to shift the control valve so as to cause a rearward movement of the slide, and a limit switch actuated by the wheel slide when it reaches its rearmost position to 25energize said first solenoid to initiate the next Sgrinding cycle.

8. In a grinding machine having a rotatable grinding wheel, a transversely movable grinding wheel slide therefor, means including a hydraulic piston and cylinder to feedsaid slide and grinding wheel toward and from a work piece, a rotatable work support including a positively driven work chuck to support and drive one end of a work piece, a plurality of rotatable rollers to steady and support said work piece at a point spaced from said collet and adjacent to said grinding wheel, a rotatable work turret automatically to convey work pieces to and from an operative position with relation to said collet, a pawl and ratchet to actuate said turret, a hydraulic piston and cylinder to actuate said pawl, a compression spring to close said chuck, a hydraulic piston and cylinder to open said chuck, and means actuated by and in timed relation with the rearward movement of said slide to conStrol the cycle of operation.

9. In a valve grinding machine having a rotatable work chuck, a transversely movable rotatable grinding wheel, means to feed said wheel toward and from the axis of said chuck, a rotatable work loading turret, a plurality of work receiving pockets arranged around the periphery of said turret, a pawl and ratchet mechanism to index said turret, a hydraulic piston and cyline 55 der to actuate said ratchet, a plurality of spaced - symmetrically arranged rollers to engage the - periphery of a work piece to steady and support *, the same when it is in an operative position, d means including a pusher automatically to push y 60 said valve axially into said chuck, an ejector to t move said valve axially out of said chuck, a pise ton and cylinder to actuate said pusher and e ejector, and means including a switch actuated y during the rearward movement of the grinding e 65 wheel to control the cycle of operation. r 10. In a grinding machine as claimed in claim e 9, the combination with the parts and features d therein specified, of a piston and cylinder to g actuate the work chuck, a solenoid actuated d 70 valve to control the admission of fluid under e pressure to said chuck cylinder, a limit switch k connected with said solenoid, a cam on said y wheel slide which is arranged during the rearI, ward movement of the wheel slide to actuate - 75 said switch and energize said solenoid and thereby automatically to initiate a work discharge and loading cycle.

11. In a grinding machine as claimed in claim 9, the combination with the parts and features therein specified, of a work chuck, a piston and cylinder to actuate said chuck, a work ejector, a piston and cylinder to actuate said ejector, a rotatable work turret, and means including a piston and cylinder to index said turret, said cylinders being connected in series so that said chuck piston first releases said chuck, then said ejector piston ejects a work piece from said chuck,, after which said index piston indexes the turret to move the next work piece into alignment with said chuck.

12. In a grinding machine as claimed in claim 9, the combination with the parts and features therein specified, of a piston and cylinder to actuate the work chuck, a solenoid actuated valve which is arranged when energized to allow fluid to exhaust from the chuck cylinder, the ejector cylinder and the turret index cylinder, and also to admit fluid under pressure to the opposite end of said ejector cylinder to cause the work pusher to move the next work piece into operative relation with said chuck, and a limit switch actuated by said turret index mechanism to energize said solenoid.

13. In a grinding, machine having a rotatable work support including a rotatable spindle and a work chuck supported thereon, means to rotate said spindle and chuck, yieldable means including a compression spring to close said chuck, means including a hydraulic piston and cylinder to open said chuck, a rotatable work loading turret having a plurality of work receiving pockets arranged around its periphery, a pawl and ratchet to index said turret,, a hydraulic piston and cylinder to actuate said ratchet, a plurality of symmetrically-arranged spaced rollers to steady and support the valve stem at a position spaced from said chuck and adjacent to said grinding wheel, means including a pusher to push said valve axially into said chuck before a grinding operation, and an ejector automatically to move said valve stem axially out of said chuck after a grinding operation has been completed.

CARL G. PLYGARE.

ELPHEGE D. LA FLEUR.

HERBERT A. SILVEN.

REFERENCES CITED The following references are of record in the 20 file of this patent: UNITED STATES PATENTS Number 1,017,881 1,779,823 1,997,551 2,003,269 2,109,600 2,110,931 2,113,387 2,117,917 2,229,312 2.260,843 2,326,034 Name Date Landis ----------- Feb. 20, 1912 Norton ----------- Oct. 28, 1930 Romaine --------- Apr. 9, 1935 Arter et al. ------- May 28, 1935 Vonderbeek -------- Mar. 1, 1938 Dyer et al. ----- _ Mar. 15, 1938 Silven ------------ Apr. 5, 1938 Silven ----------_ May 17, 1938 Silven et al. ----- _ Jan. 21, 1941 Strong ----------- Oct. 28, 1941 Jackson -----.-----, Aug. 3, 1943