US2023777A - Feed control - Google Patents

Description

H. E. BALSIGER 2,023,777

FEED CONTROL Dec. 10, 1935.

Filed July 18, 1932 4 Sheets-Sheet l 9/ INVEbgQR I BY ma ATTO NEY M10, 1935. H E AL ER I 2,023,777

FEEDIGONTROL Filed July 18, 1932 4 sheets-sheet 2 INVENTOR a I W,# i AITO NVEY i0, 1935. E, L E 2,023,777

FEED CONTROL Filed July 18, 1932 4 Sheets-Sheet 3 INVENTOR M C. BY

ATTo EY Dec. 10, 1-935. 7

H. E. BALSIGER FEED CONTROL Filed July 18, 1932 4 Sheets-Sheet 4 INVENTOR huwfd 5 BY ATT RNEY Patented Dec. 1 0, 1935 UNITED STATES PATENT OFFICE FEED CONTROL 5 Application July 18, 1932, Serial No. 623,225

21 Claims. (Cl. 51-165) This invention relates to grinding machines and particularly to means for regulating the feed of the grinding wheel toward the work and for providing various speeds of such feeding movement as the grinding wheel approaches the position at which the work is finished.

A further object is to provide means for con- Referring to the accompanying drawings which.;-. are made a part hereof and on which similar reference characters indicate similar parts,

Figure l is an end elevation of a grinding machine showing my improvements applied thereto,

Figure 2, a vertical section of the control valve and reservoir forming a part of the invention,

Figure 3, a partial front view in elevation of the control valve and reservoir of the feed regulator shown in Figure 2,

Figure 4, a diagrammatic view of the wiring system for the control circuit,

Figure 5 shows a two-throw crank shaft in relation to the grinding wheel for illustrating the operation of the invention.

Figure 6 shows the grinding wheel ready to feed into a bearing on the crankshaft and is an enlarged detail of the relation of the grinding wheel to the crank shaft shown in Figure 5,

Figure 7, a front view in elevation of a modified form of construction of the control valve using two operating solenoids,

Figure 8, a wiring diagram for the modified form of valve shown in Figure 7, and

Figure 9, a side elevation of the wheel base showing operating means for forming part of the modified form.

In the drawings numeral I indicates the bed of a grinding machine having a lower wheel base slide I I rigidly secured thereto. Within the wheel slide I I or secured thereto is a wheel feed cylinder I2. A piston I3 operates within the cylinder I2 and has attached thereto a piston rod I4 which is secured to a bracket I which is secured to or made integral with the upper wheel base slide l6. Secured in the wheel base slide II is a feed regulator cylinder IT in which operates a piston III. A reservoir I9 is mounted on a bracket 20 secured to the wheel base slide II. Reservoir I9 is partially filled with oil or other suitable liquid. The reservoir I9 has fluid chambers 22, 23 and 24. A pipe 2I communicates with the chamber 24. A port 25 leads from the chamber 24 into the chamber 22 and is provided with a spring pressed check valve 26 which permits liquid to flow freely from the reservoir I9 into the cylinder 5 H but prevents return flow from the cylinder into the reservoir. Chamber 23 communicates with chamber 24 through ports 21 and 28. A manually operable needle valve 29 controls the port 21 and a solenoid operated needle valve 30 controls the port 28. The needle valve 29 is connected by a universal joint at 36 to a rod 35 which extends to the front of the machine. A rock arm 3I is attached to the valve 30 for operating it.

One end of this rock arm is attached'to a link 32' which is attached to the armature of a solenoid 34. A spring 31 is applied about the end of the valve stem, one end of the spring engaging a stop'pin and the other end engaging under one arm of the rock arm 3|, the spring tending to rotate the rock arm in a counterclockwise direction a'sshown in Figure 3 and also tending to rotateqtheneedle valve so as to open the port at 28.

The wheel base 38 is adjustable upon the wheel base slide 'I-B independently of movement of the slide I6 by means of a manually operable wheel 39 which is connected to means for moving the wheel base'in a manner well-known in the adjustment of a grinding wheel base relative to an upper slide "upon which it is mounted. A work carriage 40 is mounted for movement transversely of the grinding wheel, being movable upon a V- shaped slide M and a flat slide 42. The work carriage has suitable means for supporting the work 43, including head-stock and tail-stock elements 44 and'45 of any suitable construction. The workas shown here is a. crank-shaft, the line bearings of which are to be ground. The work carriage may be operated in any well-known manner such as manually by hand wheel 46 or by a suitable fluid motor and may have means, not shown, for stopping the work in any predetermined position to position any portion of the work opposite the grinding wheel.

Motive fluid for operating piston I3 is supplied by a pump 41 through aline 48. Fluid is distributed for operating the wheel base toward and from the work by means of a valve 49 which delivers fluid either throu h line 50 or 5|. Fluid 50 exhausts into a reservoir in the bed of the machine through pipe 52. ffI'he valve 49 is operated by means of a rod 53 anda reversing lever 54 which is pivotally attaehedto the front of the machine bed and is urgediin a clockwise direc- 55 tion by means of spring 55. The lever 54 has a lug 56 engageable by a latch 51 for holding the lever in the position shown in Figure 1, in which position motive fluid is delivered to move the grinding wheel toward the work. A spring 58 is attached to the latch 51 to hold it in engagement with the lug 56. The latch 51 is tripped by means of a solenoid 59 which acts through a rod 68 engageable with the end of the latch opposite the lug 56. The latch may be manually tripped by means of a knob 6I. Solenoid 59 is energized when the column of mercury 65 rises so as to close circuit between 62 and 63, as will presently be described. These contacts are closed when the work has been reduced'to its finished size so that solenoid 59 will be energized to release the latch 51 whereupon the spring 55 will swing the reversing lever 54 in a clockwise direction to shift the valve 49 to admit fluid to the line 59 to withdraw the wheel base from the work. At 66 is shown a limit switch which is open when the lever is moved to the dotted line position 61. Switch 66 is in circuit with solenoid 68 which controls a valve 69 which supplies coolant through line 18 to the grinding wheel. The valve 69 is automatically closed by any suitable means when the solenoid 68 is deenergized. The purpose of the limit switch is to cut off the flow of coolant when the grinding wheel is withdrawn from the work grinding position. A sizing device 1| is in con trol of the mercury column 65 so that when the work has been reduced to approximately its final size mercury column 65 will rise to close contact between 62 and 12. When the work has been reduced to its final size contact will be closed between 62 and 63. The sizing device shown is that forming the subject matter of my copending application No. 603,236, filed April 5. 1932. The

circuits controlled by the said sizing device are similar in most respects to those described in my copending application No.'598,498, filed March 12, 1932.

Current for operating the various motors is supplied through lines 13 and 14. This may be either alternating or direct current, for purpose of convenience in describing the structure we will assume that direct current is used. In this case the high potential is reduced to approximately 10 volts by resistance indicated as a whole at 15. With alternating current a step-down transformer might be used to give the necessary low voltage. When the mercury column 65 rises to close contact between points 62 and 12 circuit is closed through wire 16, wire ll, relay '18, wire 19, resistance 80, wire 8| to lead-in wire 14 and from contact point 62 through wire 82, resistance 83, wire 84 to lead-in wire 13. Relay 18 is therefore energized to close switch 85. This closes circuit from power lines 13 and 14 through the solenoid at 34 to energize this solenoid and rotate the valve 30 in a direction to partially close the port 28. This reduces the infeed of the grinding wheel base and as described the contacts 62 and 12 are closed when the work has been reduced approximately to finished size. The grinding wheel will run for a few seconds in this position to polish the work. When the work has been reduced to its final size, contacts 62 and 63 will. be closed to close circuit through the relay 86 and close switch 81 in the same manner in which the switch was closed. Tins closes circuit through power lines I3 and i4 through solenoids 59 and 68. As has been previously described solenoid 5'9 releases the latch 51 and permits the reversing valve to reverse the wheel feed motor; the solenoid 68 cuts off coolant supply to the grinding wheel. The grinding wheel is then withdrawn preparatory to removing the work and placing a new piece in position to be ground. The limit switch 66 insures that the coolant will be cut off when- 5 ever the reversing lever is in the dotted line position 61. This prevents a flow of coolant at all times other than when the grinding wheel is in forward position. Condensers 88 and 89 are provided to prevent sparking at the contacts 62,10 63, I2 and 66 when these circuits are closed.

In operation work is placed between the head and tail stocks and the lever 54 is moved to the position shown in Figure l. The wheel is fed in rapidly by means of the motor I3 until a depend- 15 ing arm on the wheel base slide I6 engages the end of the cylinder I8. This checks the rapid in-feed of the wheel. The rapid in-tfeed is also used to allow the wheel base slide to come quickly to the forward stop or position for dressing the 20 wheel in the forward position. When valve 21 is closed it slows down the wheel movement to the necessary feed for rough grinding the work. When the work has been ground approximately to its finished size the sizing device will close con- Z5 tacts 62 and 12 to energize solenoid 34 to close off valve 28 so as to further slow down the in-' feed-of the grinding wheel. The grinding wheel will continue to be fed at a very slow rate so as to polish the work; this polishing however will 30 remove some remaining surplus stock and soiurther reduce the diameter of the work which reduced size will cause the sizing device to close contacts between points '62 and 63 to energize solenoids 59 and68. This will stop the flow of coolant and will operate the reversing valve to retract the wheel base.

In Figures 7, 8 and '9 means are shown for automatically slowing down the wheel in-feed as. the grinding wheel reaches the point at which it 40 begins rough grinding. Switch 94 is secured on the bed of the machine. A lever is pivotally attached to the sub-slide which is mounted on the bed of the machine and the upper free end of the lever 95 carries a roller 96 engageable 45 with a cam 91 which is adjustably secured to the wheel base. When the grinding wheel moves in and reaches the point at which the edge 99 of the wheel contacts with the shoulder of the work at 92 the wheel base contacts piston I8 to slow so down wheel in-feed. When the grinding wheel moves further inwardly. and reaches the point at 93 its periphery contacts with the work to begin rough grinding, the cam 91 through the levers just described closes switch 94. This closes a 55 circuit to energize the solenoid 98 to close switch 99. The switch 99 is in circuit with solenoid I98. The solenoid I98 has an armature I8I connected by link I 92 with one arm I93 of a rock arm which is secured to a valve stem I94 which valve stem to is similar in all respects to the valve 29. An adjustable' screw I05 is provided for limiting the movement of the arm I03. v

In operation, in the form just described, the grinding wheel 9i moves to the position shown 95 in full'lines in Figure 6. Just as it reaches this position the in-feed is slowed down by means of the wheel feed regulator I1. The wheel moves in at a speed which is still in excess of the grinding speed but which is suitable for grinding oil? 70 the edges of the shoulder 92 on the crank pin. The wheel continues to move in relatively fast until it reaches the dotted line position 93 shown in Figure 6. At this time the cam 91 closes switch 94 which partially or entirely. closes off 75 the valve port corresponding to port 21 in Figure 2. The wheel in-feed is therefore checked and the wheel moves in at rough grinding speed. When the work has been reduced approximately to its finished size solenoid I06 will be energized to further slow down the wheel in-feed and practically stop it for a polishing grinding. The solenoid M6 is energized when the work has been reduced to approximately its finished size. The for doing this includes the sizing device it by means of which circuit is closed between contacts 62 and 12 as is more fully dese the co'pending application referred to. This polishing of course will reduce the size 01. the work somewhat more which size will be gaged, and caused to operate the solenoids 59 and 68 as described more fully in the preferred form.

lit will be obvious to those skilled in the art that various changes may be made in my device without departing from the spirit of the invention and therefore I do not limit myself to what shown in drawings and described in the specification, but only as indicated in the appended claims.

Having thus fully described my said invention, what I as new and desire to secure by Letters Patent, is:

l. in a grinding machine having a wheel base movable toward and from the work to be ground, sizing device, a motor for moving the wheel toward and from the work, means for limiting the speed with which the wheel base moves toward the work comprising hydraulic means for first checking movement of the wheel base toward the work at a predetermined distance from the work to be ground, hydraulic means for further limiting the speed of movement toward the work as the grinding wheel engages the work, and electrically operable means controlled by the said sizing device for further controlling the said lastnamed hydraulic means for limiting the speed of tiovement of the grinding wheel toward the work as the work reaches approximately its finished size, substantially as set forth.

A grinding machine of the kind described comprising a work carriage adapted to support work to be ground, a wheel base having a grinding wheei mounted thereon, work sizing means on the Work carriage, means for moving the wheel toward and from the work at high speed, pressure fluid means for slowing the speed with which the wheel base moves toward the work as the grinding wheel reaches approximate grinding automatically operable pressure for further slowing down movement 1e grinding wheel toward the work as the .a, approximately its finished size, said last named means being controlled by the said sizing device, substantially as set forth.

3. f1). machine for grinding crank pins on a crank shaft comprising work supporting means, a work sizing device, a wheel base movable toward and from. the work, said wheel base having a grinding wheel mounted thereon, means for moving the wheel base at high speed toward and irom the work, a dash pot for checking the high speed movement as the grinding wheel engages the outermost portion of the work, means operated by the wheel base for controlling said dash pot for further slowing down movement of the wheel base as the grinding wheel contacts with the work to effect rough grinding, and means controlled by the sizing device for further controliing said dash pot for slowing down movement of the grinding wheel toward the work as the work "reaches approximately its finished size, substantially as set forth.

4. A machine for grinding crank pins on a crank shaft comprising a work supporting means,

a work sizing device, a wheel base movable toward and from the work, said wheel base having a grinding wheel mounted thereon, means for moving the wheel base at high speed toward and from the work, hydraulic means for checking the high speed movement as the grinding wheel en- 1 gages the outermost portion of the work, means operated by movement of the wheel base for controlling said hydraulic means for further slowing down movement 01' the wheel base as the grinding wheel contacts with the work to efiect 15 rough grinding, means controlled by the sizing device for further slowing down movement of the grinding wheel toward the work as the work reaches approximately its finished size, and additional means controlled by the sizing device for stopping movement of the grinding wheel toward the work and for effecting its withdrawal as the work is reduced to its finished size, substantially as set forth.

5. A grinding machine of the kind described comprising a base, a work carriage movable thereon, work supporting means on said work carriage, a wheel base having a grinding wheel mounted thereon and movable toward and from grinding position, a motor for moving the said wheel base at high speed toward and from the work, hydraulic means for slowing down movement of the wheel base toward the work as the grinding wheel reaches a predetermined position relative to the work, and electrically con- 5 trolled means for controlling said hydraulic means responsive to a change in size of the work for further slowing down the movement oi the wheel toward the work as the work is reduced to a predetermined size, substantially as set forth.

6. A grinding machine 01' the kind described comprising a base, a work carriage movable thereon, work supporting means on said work carriage, a wheel base having a grinding wheel mounted thereon and movable toward and from grinding-position, a motor ior'moving the said wheel base at high speed toward and from the work, hydraulic means for slowing down movement of the wheel base toward the work as the grinding wheel reaches a predetermined po- 5 sition relative to the work, electrically controlled meansfor controlling said hydraulic means for further slowing down the movement of the wheel toward the work as the work is reduced to a. predetermined size, and still further means for stopping forward movement of the wheel toward the work when the work is reduced to finished size, said means eifecting withdrawal of the wheel from the work, substantially as set forth.

7. A grinding machine of the kind described so comprising work supporting means, a wheel base having a grinding wheel mounted thereon and movable toward and from the work, a motor for moving said wheel base at high speed toward and from the work, fluid pressure means for checking movement of the grinding wheel toward the work to cause said grinding wheel to be moved first at one speed and then at a slower speed toward the work, work sizing means, said work sizing means eilecting one of the slow speed 7o movements, said work sizing means also eflect ing withdrawal of the wheel base when the work has been reduced to its finished size, a reversing lever in control 01' the movements or the said wheel base, means for supplying coolant to the grinding wheel, and means operated by the said reversing lever for shutting off the supply of coolant to the'grinding wheel, when the grinding wheel base is moved away from work grinding position, substantially as set forth.

8. Means for grinding bearings of a crankshaft which bearings have shoulder portions, comprising work supporting and work sizing means, a wheel base having a grinding, wheel mounted thereon and movable toward and from the work, a motor for moving said grinding wheel at high speed toward the work, hydraulic means for checking the high speed movement when the periphery of the grinding wheel reaches, approximately the shoulder portion on the work to permit relatively slower movement as the grinding wheel moves inwardly to grind the shgulder portions of the work, means operated by the wheel base for controlling said hydraulic means for further slowing down the movement of the grinding wheel toward the work as the periphery of the grinding wheel comes approximately into grinding contact with the work and electrically controlled means for further slowing down movement of the wheel base toward the work as the work is reduced approximately to its finished size, said last named means being controlled by said work sizing means, substantially as set forth.

9. Means for grinding bearings of a crankshaft which bearings have shoulder portions, comprising work supporting and work sizing means, a wheel base having a grinding wheel mounted thereon and movable toward and from the work,

. v a motor for moving said grinding wheel at high speed toward the work, means for checking the high speed movement when the periphery of the grinding wheel reaches approximately the shoulder portion on the work to permit relatively slower movement as the grinding wheel moves inwardly to grind the shoulder portions of the work, means operated by movement of the wheel base toward the work for further slowing down the movement of the grinding wheel toward the work as the periphery of the grinding wheel comes approximately, into grinding contact with the work and electrically controlled means for further slowing down movement of the wheel base toward the work as the work is reduced approximately to its finished size, said last named means being controlled by said work sizing means, said work sizing means effecting withdrawal of the wheel base when the work has been reduced to its finished size, substantially as set forth.

10. A grinding machine of the kind described having work sizing means, work grinding means movable toward and from the work a conduit for supplying coolant to the work and tool, a valve in said conduit, a fluid motor for moving said grinding means at high speed from the work and at high speed toward the work, means for checking the high speed movement toward the work as the grinding means comes into contact with some portion of the work, manually operable means for further slowing down movement of the grinding means toward the work as the periphery of the grinding wheel contacts the work to effect rough grinding of the same, said sizing means causing further, slowing down the movement of the grinding means as it moves toward the work, said work sizing means also initiating withdrawal of the grinding wheel and shutting off the coolant to the grinding wheel as the work isreduced to finished size, substantially as set forth.

11. A grinding machine of the kind described having a work carriage, a work support on said carriage, a grinding wheel support, a fluid motor for moving said grinding wheel support toward and from the work support, a hydraulic feed regulator for controlling the speed of movement of the wheel support toward the work support, and automatic means responsive to changes in size of the work for adjusting said regulator to control the speed of movement of the wheel support toward the work support, substantially as regulator to further slow down the feed toward 20 the work, and means controlled by the work for still further controlling said regulator to further slow down the feed of the 'wheel toward the Work, and means controlled by the'size of the work for stopping the feed toward the work and for reversing the wheel base.

13. In a grinding machine having a work support and a Wheel support, a fluid motor for effecting relative movement between said supports, a dash pot in control of the movement of said supports toward each other, a valve in control of said dash pot for controlling the speed of movement of said supports toward each other, and a sizing device for controlling said valve to control the working speed of said supports toward each other.

14. In a grinding machine, a work support and a wheel support, a sizing device, a fluid motor for moving said wheel support toward and from said work support, a dash pot for controlling the feeding movement of said wheel support toward said work support, a valve operated by movement of the wheel support for partially controlling said dash pot, and a second valve operated by said sizing device for further controlling said dash pot to provide a further slowing down of feeding speeds of said wheel support toward the work.

15. In a machine of the kind described, a work support, a tool; support, hydraulically actuated means for driving one of said supports, mechanism for opposing said driving means to control the rate of movement of said support, and means responsive to a change in size of a work piece to regulate the action of said opposing means to vary the effect thereof on said driving means.

16. In a machine of the kind described a tool support, a work 'support, means to effect a rapid movement of one of said supports toward and from the other,- mechanism for opposing said rapid moving means to change said rapid movement to a slow movement at a predetermined point and automatic means responsive to changes in size of. the work adapted to control said mechanism to effect intermittent changes in said slow movement.

1'7. In a machine of the kind described, a work support, a tool support, fluid means to effect a rapid transverse movement of one of said supports toward the other to place the tool and work in grinding position, mechanism separate from said fluid pressure mechanism operable thereafter to effect a slow feeding movement of said support in the same direction, and means re sponslve to a change in size of a work piece to 75 control said mechanism to vary the speed of said slow feed.

18. In a machine of the kind described, a work support, a tool support, a sizing device, means to move one of said supports toward the other at a plurality of speeds and for separating them at a relatively high speed, mechanism to change from high speed to slow speed including a dashv pot, means responsive to movement of the wheel base toward the work for controlling the dash pot to vary said slow speed, means actuated by said sizing device when the work reaches a predetermined size to control said dash pot to eiiect a further change in speed, and additional means actuated by said sizing device for stopping the feeding movement and for withdrawing the wheel base from the work.

19. In a machine of the kind described, a work support, a tool support, a sizing device, means to move one of said supports toward the other at a plurality of speeds and for separating them at a relatively high speed, mechanism to change from high speed to slow speed including a dash pot, and means actuated by said sizing device when the work reaches a predetermined size to control said dash pot to vary said slow speed.

20. In a machine of the kind described a work support, a tool support. fluid means to effect a rapid transverse movement of one of said supports toward the other to place the tool and the work in grinding position, mechanism separate from said fluid pressure mechanism operable to efiect a slow feeding movement of said support 5 in the same direction, a pneumatically operated sizing device in control of said slow feeding mechanism and means actuated by said sizing device in response to a change in size of a work piece to control said mechanism to vary the 10 speed of said slow feed.

21. In a machine of the kind described a work support, a tool support, fluid means to eflect a rapid transverse movement of one of said supports toward the other to place the tool and the 15 work in grinding position, mechanism separate from said fluid pressure mechanism operable to efl'ect a slow feeding movement of said support in the same direction, a pneumatically operated sizing device in control of said slow feed- 20 ing mechanism, means actuated by said sizing device in response to a change in size of a work piece to control said mechanism to vary the speed of said slow feed, and means actuated by said sizing device in response to a further change 5 in size of said work piece to separate the work and the grinding wheel.

HAROLD E. BALSIGER.

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