US1952432A - Grinding machine - Google Patents

Description

March 27, 1934.,- F s HMS 1,952,432

GRINDING MACHINE Filed April 28, 1930 2 SheebS-Shl-Zel l March 27, 1934. F. s. HAAs GRINDING MACHINE Filed. April 28, 19:50

2 Sheets-Sheet 2 Q m mw mw QN i mm. YL Q N Q @N Q w NNNI Y mwN BQQYNN RM y my NN f .Il fw N y i mm Q K N n Nh QN.. .NN mw w Patented Mar. 27, 1934 GRINDING MACHINE Frederick S. Haas, Cincinnati, Ohio, assignor to Cincinnati Grinders Incorporated, Cincinnati, h10, a corporation of Ohio Application April 28, 1930, Serial No. 447,842

18 claims. (0151-95) This invention relates to improvements in machine tools and especially to improvements in center type grinding machines.

An object of the invention is the provision of improved mechanism for actuating a movablev slide of a machine tool organization.

Another object of the invention is the provision of improved means associated with the tool slide of a machine tool organization to insure l0 the retraction of the slide to carry the tool a sufficient distance away from the work while same is being replaced so that no inadvertent engagement between the work and tool may occur.

Another object of the invention is the provision of automatic mechanism for retracting and advancing a tool slide relative to the work which supplements the normal feeding mechanism of the slide.

A further and specific object of the invention is the provision of a grinding machine having a grinding wheel slide movable toward andfrom the work including improved means supplementing the normal feeding means so that at the completion of the grinding operation and upon reversal of the feeding means a certain definite retraction of the slide takes place before' the automatic retraction of the slide to permit replacement of a work piece in the machine.

Other objects and advantages of the present invention should be readily apparent by reference to the following specification considered in conjunction with the accompanying drawings forming a part thereof and it is to be understood that any modifications may be made. within the exact structural details there shown and described Within the scope of the appended claims without departing from or exceeding the spirit of the invention.

In the drawings:

Figure 1 is a front elevation of a grinding machine embodying the improvements of this invention.

Figure 2 isa transverse sectional view of the machine shown in Figure l as seen from line 2 2 thereon.

Figure 3 is a fragmentary view as seen from line 3 3 of Figure 2. l

Figure 4 is a fragmentary elevational view of certain parts shown in Figure 3 as seen from line 4 4 thereon.

Figure 5 is a sectional View taken on line 5 5 of Figure 3.

Figure 6 is a diagrammatic view illustrating the hydraulic circuit involved in this application, and

Figure 7. is an enlarged fragmentary sectional view of a part of the disclosure shown in Figure 2 illustrating the connection between the mechanical means and the hydraulic means.

Throughout the several views of the drawings similar reference characters are employed to denote the same or similar parts.

A device of this invention may comprise a bed 10 having mounted thereon for longitudinal reciprocation a work supporting table 11. Any desirable means may be employed for reciprocating the table l1 which has adjustably secured thereto a tail stock 12 and a head stock 13 having the 9 usual center and driving dog for supporting and rotating a workpiece 14. Supported by the bed 10 for movement transversely thereof on suitable Ways l5 is the grinding wheel slide 16 having journaled therein spindle 17 for grinding wheel 75 18. The carriage 16 is adapted to be actuated by either manual or mechanical means toward and from the work 14. For this purpose the said carriage has depending interiorly thereof a web 19 in which is secured a nut 20 threadedly receiv- 80 ing cross feed or adjusting screw 21. The screw 21 has a splined portion 22 telescoping within a complementary spline hub 23 of driving gear 24. The hub 23 is journaled in bearing 25 of housing 26 secured to the rear wall of the bed or support 10. The housing 26 supports a stub shaft 27 for compound idler gear 28 having its smaller step 29 in mesh with gear 24. 'Ihe larger gear 30 of idler gear 28 meshes with a driving pinion 31 secured to the rear end of transverse or driven shaft 32. The inner end of the transverse shaft 32 has integral therewith drive gear 33 enclosed within housing 34 secured to the forward face of the bed or support 10. The housing 34 also acts as a journal for the inner end of transverse 9 shaft 32 and also supports the mechanism, indicated generally by the numeral 35, for rotating the drive gear 33. It should be understood that the mechanism 35 is actuated either automatically by the pick feedsystem which terminates in dog 36, shown in Figure 1, or the mechanism 35 may be actuated manually by the crank or handle 37.

It is to be understood that the dog 36 of the pick feed automatic mechanism is actuated at each end of the strokeof the work reciprocating table 10D 11 as is well understood by those conversant With the art.

From the foregoing it will be noted that the carriage 16 is actuated either automatically or manually toward and from the work supporting table 11. This mechanism however, is a very slow process requiring considerable time and ef4 fort to retract the grinding wheel a sufficient distance to permit the replacement of work pieces on the table. This retraction is generally accomplished manually by rotating the mechanism 35 through the medium of the handle 37. The time and effort involved in retracting the wheel and carriage has led to the careless practice on the part of grinding machine operators to retract the wheel an amount barely suiiicient to permit the removal of the work piece so that when a new work piece was placed on the work supporting table it frequently engaged the surface of the grinding wheel causing the work to be marred sometimes beyond repair. Frequently the wheel was backed away a-suilicient distance to permit the replacement of the work piece without contacting with the wheel but' the operator would then negligently advance the grinding wheel toward the work at such a rate of speed that the slight clearance between the wheel and work was soon taken up and the wheel rammed into the work resulting in a jar to the machine and sometimes injury to the wheel and work.

To overcome the difficulties just enumerated and to insure the retraction of the wheel an amount suiiicient to replace the work piece on the table so that the operator knows definitely the position of the wheel with respect to the work the following improved mechanism has been provided. The adjusting screw 21 is provided With a plane portion 38 beyond the splined portion 22 and surrounded by a packed bearing 39 carried by plate or head 40 secured to a housing 41 which housing in turn is secured to the housing 26. The plane portion 38 of the screw 21 terminates in a reduced threaded stud 42 on which a piston 43 is secured. This piston 43 is adapted to be actuated through a cylinder 44 formed integral with the housing 41 which cylinder is closed at one end by the plate or head 40, above referred to, and `at the other end by a head 45. An hydraulic medium under pressure is introduced into the cylinder 44 at one side of the piston 43 through a port 46 which empties into an annular recess 47 formed in the head 45 to the righthand side of the piston 43 to actuate same to the position shown in Figure 2. This medium enters the cylinder to the other side of the piston 43 through a port 48 to an annular recess 49 formed in the head 40 from which the medium ows through a series of ports 49a to the left hand side of piston 43. The flow of the hydraulic medium to either of the ports 46 and 48 is controlled by a slidable valve 50 enclosed in a suitable casing formed integral with the housing 41. The valve 50 is received in and slides through a sleeve 51 fastened in the valve casing'and has the inlet port 52 through which the hydraulic medium enters the said sleeve. The medium is conveyed to the port 52 through a conduit 53 by a pump 54 which draws the medium through conduit 55 from a sump or tank 56. The hydraulic medium then passes, as shown in Figure 6, from the sleeve 51 through a conduit 57to the port 48, annular recess 49 and ports 49a. The medium ahead of the piston 43 is forced from the cylinder 44 through the annular recess 47 and conduit 46 for conveyance by a conduit '58 to the sleeve 51 from which it is directed through conduits 59 and 60 back to the tank or sump 56.'

To shift the valve 50 it is provided with a stem 6l in which a groove 62 is formed to provide shoulders 63 and 64. Apin 65 is .received in the slot 62 intermediate the shoulders 63 and 64 being carried by an arm 66 frictionally mounted on the end of transverse or driven shaft 32. The arm 66 surrounds a bushing 67 and abuts on one side with the face of a flange 68 formed integral with the bushing 67. A collar 69 keyed or otherwise secured to the bushing 67 for rotation therewith but for sliding movement relative thereto abuts the arm 66 on its other side and the said collar 69 is heldin engagement with the arm 67 by a spring 70 abutting on -one end therewith and on the other end with a nut 71 threaded to the end of the bushing 67. This bushing 67 has journaled interiorly thereof the reduced end of the transverse or driven shaft 32 having anti-friction bearings mounted therebetween. A pin 72 extends from the flange 68 into the path of movement of a second pin 73 extending upwardly from the hub 74 of driving pinion 31. From this it will be noted that rotation of the transverse or driven shaft 32 and pinion 31 will positively shift the valve 50 in one direction while the said Valve is mpositively shifted in the other direction. This impositive shifting means comprises a spring 75 mounted within the bore 76 formed centrally of the said valve 50 and the spring 75 abuts on one end a shoulder 77 formed by the bore 76 and on the other end with an adjustable abutment pin 78. The position of the pin 78 is determined by the stop screw 79 adjustable through a cap 80 secured to the housing 41. A lock'nut 8l is carried by the adjusting screw 79 to lock the same in its several positions.

With the foregoing description in mind and assuming the work piece has been reduced to the required size and it is desired to retract the grinding wheel from the work piece or actuate wheel 18 and slide 16 to the right as seen in Figure 2 the operator would actuate the handle 37 by rotating it in the proper direction together with the transverse shaft 32. In practice this would cause the pin 73 carried by the hub or driving pinion 31 to leave pin 72 Without moving same or any of the parts connected therewith and the reduced end of the shaft 32 would rotate on the anti-friction bearing mounted within' the bush-A ing 67. Substantially a complete revolution of the handle 37, shaft 32 and driving pinion 31 has taken place before the pin 73 carried by pinion 3l, engages pin 72 on the side opposite to that shown in Figure 2, at which time a continued movement of the handle would cause the pin 72 to be moved by the pin 73 which would eiTect a movement of bushing 67, flange 68, friction collar 69 and actuating arm 66 with the shaft 32, and the arm 66 through the pin 65 would shift valve 50 to permit the hydraulic medium under lpressure to enter the cylinder 44 to the left hand face of piston 43, as seen in Figure 2, to actuate same to the right carrying with it the grinding wheel carriage 16 and grinding wheel 18. During the movement of the valve 50 the spring 76 contained therein was compressed and is held under tension during the replacement of the work piece on the table 11. As soon as the new work piece has been mounted between the head and tail stocks the handle 37 is actuated to feed the grinding wheel and carriage toward it which would cause the pin 73 to leave the pin 72 whereupon the spring 75 would expand to shift the valve to its other extreme position causing a simultaneous rapid advancing movement of the grinding wheel and its carriage toward the work. This movement under the influence of the hydraulic pressurereturns the parts to the position occupied means, must be taken up at the time of the completion of one revolution of the handle 37 so that the wheel and work are still spaced a distance corresponding to the said one revolution of the handle 37 which is taken up by the operator in the usual way.

It is to be understood that at least one complete revolution of the handle is necessary before the hydraulic mechanism comes into play for actuating the slide away from the work. However, the rotation of the handle 37 is not limited to only one revolution but any desired number of revolutions; partial revolutions may be made since after the first revolution and after the 'shifting of the valve 50 the pin 73 will carry with it the pin 72 and cause a slipping between the flange 68, collar 69 and the actuating arm 66 without in any way aiecting the position of the arm 66 and the holding of the valve in the necessary position to direct the hydraulic medium against the face of the piston 43 to hold the grinding wheel in a position remote from the work piece. However, when more than one revolution of the handle has been resorted to for backing or retracting the grinding wheel and carriage from the work, independent of the retracting movement by the hydraulic means, the same number of revolutions of the handle 37 or the same amount of feeding of the grinding wheel and carriage toward the work must take place after the return of the parts under influence of the hydraulic medium.` In other words, the movement of the grinding wheel and carriage under influence of the hydraulic means is always the same and any supplemental movement given them away from the work whether by manual or mechanical by the same means by feeding the grinding wheel andcarriage toward the work. While the operation and control of grinding wheel and carriage has been described in connection with the manually operable handle 37 it is to be understood that any reversibleautomatic feeding means may be employed to accomplish the same result.

To prevent a sharp coming together of the sides,of the piston 42 with the caps or heads 40 and 45 the said 'sides of the piston are provided with reduced projections 82 and 83 cooperating with recesses 84 and 85 formed on the adjacent faces of the caps or heads 40 and 45. The projections 82 and 83 and recesses 84 and 85 act as dash pots for cushioning the engagement of the piston proper with definite stops formed on the heads 40 and 45. The recesses 84 and 85 are respectively provided with a port 86 and 87 through which the hydraulic medium therein is discharged. This discharge being controlled by needle valves 88 and 89 threaded respectively into the head 45 and housing 41. The medium after passing the needle valves enters the annular recesses 47 and 49 for conveyance by the proper conduit to tank or sump 56.

By reference to Figure 2 it will be noted-that housings 26 and 41 extend above the bed or support 10 into the vpath of movement of the grinding wheel carriage 16 when said carriage is being retracted. In the operation of the machine on work pieces of the usual run of work, which are generally of a size below the capacity of the machine, the rear piston head stops the retraction of the carriage with the housing 26. However, when operating on large diameter work or work near the capacity of the machine, the carriage 16 is retracted to a position where the rear piston head 45 would not stop the retraction of the carriage by the 16 before it can contact piston 43 prior to its engagement with the hous ing 26 without means for stopping the movement prior to its engagement with the cylinder head 45. To this end there is pivotally mounted on the housing 26 a bell crank 91 having arms 92 and 93. A stop screw 94 is adjustably mounted in the arm 92 to be engaged by the rear wall of the grinding wheel carriage 16. The arm 93 is bifurcated to provide fingers 95 and 96 engaging on the opposite sides of a pin 97 which extends from a plunger 98 vertically shiftable through a housing 99 formed integral with the housing 41, A spring 100 surrounds the plunger 98 for holding same in an elevated position, as shown in Figures 3 and 4. The lower end of the plunger 98 is wedge shape to provide a cam face 101 for engagement with a cam face 102 formed adjacent the outer end of valve stem 61.

In operation the retraction of the carriage 16 causes the end thereof to engage adjustable abutment or stop screw 94 to actuate the lever 91 in a clockwise direction about its pivot from the position shown in full lines in Figure 4, to the position shown in dotted lines to thereby depress plunger 98 and through the interengagement of the cam faces 101 and 102 shift the valve to a neutral position thereby. stopping further retraction of the grinding wheeland carriage. By reference to Figure 3 it will be noted that the shifting of the valve 50 by the cam facesr101 and 102 partially releases the spring 76 by oscillating the actuator arm 66 relative to the friction mechanism associated therewith. The spring 76 is, however, still under partial compression rso that as soon as the grinding wheel and carriage are actuated toward the work the spring expands f ,the slide at a slow rate including a shaft, means for actuating the slide at a rapid rate including a piston, an hydraulic medium for actuating this piston, a shiftable reversing valve controlling the direction of flow of the medium and direction of movement of the piston, and means operatively connecting the valve with the shaft whereby actuation of the shaft in one direction effects instantaneous shifting of the valve and actuation of the shaft in the other direction effects a delayed shifting of the valve. i

2. In a machine tool organization the com@ binationV of a bed, a slide carried thereby and movable relative thereto, a driven shaft carried by the bed, an adjusting screw carried by the bed and operatively connected with the slide, transmission means between the shaft and the screw whereby the screw is rotated, means for rotating the shaft at a slow feeding rate to correspondingly actuate the slide and means connected with the screw and energizable by the shaft for axially shifting the screw at a rapid rate together with the slide.

3. In a grinding machine the combination of a bed, a work supporting table carried thereby and movable longitudinally thereof, a grinding Wheel carriage carried transversely of the bed toward and from the work supporting table, means for actuating the by the bed and movable carriage at a slow rate in the direction away from the work supporting table for a predetermined distance, and means energizable by the slow rate means for continuing the movement of the slide at a rapid rate away from the work supporting table after it has been moved the said predetermined distance.

4. In a grinding machine the combination of a bed, a tool slide carried thereby and movable transversely thereof, means for actuating the slide at a slow feeding rate including a driven shaft, an adjusting screw operatively coupled with the shaft forrotation thereby, a piston on the screw, hydraulic means for actuating the piston and screw at a rapid rate and including a valve, means operated by the shaft for actuating the valve to control the direction of flow of the medium and direction of movement of the piston, a cylinder for the piston, a closure head on each end of the piston, and means carried by the piston and heads for cushioning the engagement of the piston with said heads.

5. In a machine tool organization the combination of a bed, a tool slide carried thereby and movable relative thereto, reversible feeding means for actuating the slide at a slow rate in cluding a driven shaft, anadjusting screw connected with the slide, transmission means between the driven shaft and adjusting screw for actuating same, a piston on the screw, a cylinder for the piston, an hydraulic medium under pressure for actuating the piston through the cylinder at a rapid rate and axially moving the adjusting screw and slide correspondingly, a shiftable valve controlling the direction of ow of the medium, and a connection between the driven shaft and valve wherebyoperation of the driven shaft in one direction will effect a predetermined amount of rotation of the screw prior to the shifting of the valve and piston and whereby operation of the shaft in the other direction will effect a substantially instantaneous shifting of the valve and piston and rotation of the screw.

6. In a machine tool organization the combination of a bed, a tool slide carried thereby and movable relative thereto, means for operating the tool slide at a slow rate includinga driven shaft, an adjusting screw operatively connected with the slide, transmission means between the shaft and screw, means for actuating the slide at a rapid rate including a piston on the screw, an hydraulic medium for actuating the piston,`a valve for controlling direction of flow of the medium, a lost motion connection between the driven shaft and valve for actuating the valve and whereby a predetermined amount of slow movement is given the slide before the actuation of the valve and the rapid movement of the slide by the piston, means associated with the last mentioned means whereby the driven shaft may be additionally actuated without affecting the setting of the valve or movement of the piston.

7. In a machine tool organization the combination of a bed, a tool slide carried thereby and movable relative thereto, means for actuating the slide at a slow feeding rate including an adjusting screw, a driven shaft, transmission means between the adjusting screw and driven shaft, hydraulic means for actuating the slide at a rapid rate including a piston carried by the adjusting screw for effecting axial movement of the screw, .an hydraulic medium under pressure for actuating the piston, a valve controlling the direction of flow of the medium, means carried by the driven shaft for actuating the valve in one direction, and yielding means associated with the valve for operating same in the other direction.

8. In a machine tool organization the combination of a bed, a tool slide carried thereby and movable transversely thereof, a bracket on the bed in the path of movement of the slide, hydraulic means carried by the bracket for actuating the slide including a valve, a cam face on the valve, a pivotally mounted bell crank carried by the bracket adapted to be engaged by the slide, a yieldably shiftable plunger carried by the bracket operatively connected with the bell crank whereby engagement of the bell crank by the tool slide causes a depression of the plunger and a shifting of the valve to a neutral position through the interengagement of the cam faces to stop the movement of the slide, and yielding means for returning the plunger to its normal inoperative position.y

9. In a grinding machine the combination of a bed, a work supporting table carried thereby and movable longitudinally thereof, a tool slide carried by the bed and movable transversely thereof toward and from the work table, mechanical means including a driven shaft for actuating the slide away from the table a predetermined distance, hydraulic means for actuating the slide away from the table including a valve, and means between the shaft and valve operable by the shaft for shifting the valve after the slide has been moved the said predetermined distance by the mechanical means and forinstantaneously shifting the valve upon reversal of the shaft.

. 10. In a grinding machine the combination of a bed, a grinding wheel carriage carried thereby and shiftable relative thereto, an adjusting screw having a threaded engagement with the carriage,A

the screw having a splined portion thereon, a gear connected with the screw through the splined portion whereby the screw is rotated with the gear while the screw may be axially shifted relative to the gear, a piston on the screw, means for rotating the gear for adjusting the slide at a slow rate and for shifting the piston for moving the slide at a rapid rate independent of the movement thereof by the gear, and a common control member for energizing and operating the said gear and piston.

11. In a grinding machine the combination of a bed, a grinding wheel carriage carried thereby and shiftable relative thereto, an adjusting screw having a threaded engagement with the carriage, the screw having a splined portion thereon, a gear connected with the screw through the splined portion whereby the screw is rotated with the gear while the screw may be axially shifted relative to the gear, a piston on the screw, means for rotating the gear for adjusting the slide at a slow rate, means for controlling the shifting of the piston for moving the slide at a rapid rate independent of the movement thereof by the gear, and means having a direct connection with either the gear rotating means or the piston control means for positively actuating same and having a lost motion coupling with the remaining means.

l2. In a machine tool organization the combination of a bed, a tool slide carried thereby and movable relative thereto, reversible means for actuating the slide at a slow rate of speed, mechanically operated means for actuating the slow rate means, reversible means for actuating the slide at a rapid rate, a pressure source for operating the fast rate moving means, and a common control means for the mechanical and pressure slide shifting means interconnected therewith for effecting the simultaneous and sequential operation of said mechanical and pressure slide shifting means ina given direction.

13. In a grinding machine the combination of a bed, a work supporting table mounted thereon for translatory movement relative thereto, a grinding wheel slide carried by the bed for movementtoward and from the work supporting table, an adjusting screw rotatably and slidably supported by the bed and operatively connected with the grinding wheel slide, a piston secured to the screw, a rotatable shaft carried by the bed, transmission means between the shaft and screw whereby rotation of the shaft effects rotation of the screw and adjustment of the. slide, an hydraulic medium for shifting the piston, screw and slide, and a valve controlling the direction of flow of the medium and operatively connected with the shaft whereby rotation of the shaft in adirection to retract the grinding wheel slide from the Work table will rotate the screw a predetermined amount prior to the'shifting of the valve and the retraction of the slide by the piston.

14. In a grinding machine the combination of a bed, a work supporting table mounted thereon 'for translatory movement relative thereto, a

grinding wheel slide carried by the bed for movement toward and from the work supporting table, an adjusting screw rotatably and slidably supported by the bed and operatively connected with the grinding wheel slide, a pist-on secured to the screw, a rotatable shaft carried by the bed, transmission means between the shaft and screw whereby rotation of the shaft effects rotation of the screw and adjustment of the slide, an hydraulic medium for shifting the piston, screw and slide, a valve controlling the direction of flow of the medium and operatively connected with the shaft whereby rotation of the shaft in a direction to retract the grinding wheel slide from the work table will rotate the screw a predetermined amount prior to the shifting of the valve and the retraction of the slide by the piston, and means associated with the Valve and shaft connecting means whereby the shaft may be additionally rotated for additionally rotating the screw without affecting the movement of the valve.

15. In a grinding machine of the class described the combination with a" bed and a work supporting table mounted thereon for translation relative thereto, of a grinding wheel slide carried by the bed for movement toward and from the Work supporting table, mechanical means for shifting the slide at a slow rate toward and from the table, hydraulic means for shifting the slide ata rapid rate toward and from the table, and ueans for automatically energizing the slow rate and rapid rate shifting means in sequential order whereby the grinding wheel slide is actuated at a rapid rate toward the table, actuated at a slow rate toward the table, actuated at a slow rate from the table, and actuated at a rapid rate from the table.

16. In a grinding machine of the class described the combination with a bed and a Work supporting table mounted thereon for translation relative thereto, of a grinding wheel slide carried by the bed for movement toward and from the work supporting table, mechanical means for shifting the slide at a slow rate toward and from the table, hydraulic means for shifting the slide at a rapid rate toward and from the table, means for energizing the slow rate and rapid rate shifting means in sequential order whereby the grinding Wheel slide is actuated at a rapid rate toward the table, actuated at a slow rate toward the table, actuated at a slow rate from the table, and actuated at a rapid rate from the table, and means associated with the slow rate moving means whereby it may be operated when the rapid rate moving means is at the end of its movement and without disturbing said means.

17. In a grinding machine of the class described the combination with a bed and a table carried thereby for translation relative thereto, of` a grinding wheel slide mounted on the bed. for movement toward and 'from the work supporting table, means for actuating the slow rate moving means, means for actuating the rapid traverse rate moving means, and a connection between the slow rate means and the rapid rate means whereby the slow rate means is operated for shifting the slide in one direction through a Ypredetermined zone prior to the actuation of the rapidv rate means and whereby. the operation of the slow rate means in the opposite direction instantaneously effects operation of the rapid rate means in said reverse direction.

18. In a grinding machine of the class described the combination with a bed and a table carried thereby for translation relative thereto, of a grinding wheel slide mounted on the bed for movement toward and from the work supporting table, means for actuating the slow rate moving means, means for actuating the rapid traverse rate moving means, a connection between the slow rate means and the rapid rate means whereby the slow rate means is operated for shifting the slide in one direction through a predetermined zone prior to the actuation of the rapid rate means and whereby the operation of the slow rate means in the opposite direction instantaneously effects operation of the rapid rate means in said reverse direction, and means for automatically cutting out the rapid rate means just prior to the slide reaching the end of its travel.

FREDERICK S. HAAS.

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