US1665160A - Automatic size-grinding machine - Google Patents

Description

April 3, 1928. 1,665,160

s. EINSTEIN ET AL .6 AUTOMATIC SIZE GRINDING MACHINE Filed July 29, 1925 a sheets-sheet 1 v J" V y /J I .1 J0 45 J5 712 Snow Toma -51 6(2 fez 7?,

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1,665,160 S. EINSTEIN ET AL AUTOMATIC SIZE GRINDING MACHINE Fil y 29, 1925 's Sheets-Sheet 2 Jar f7 f 10g 5 0 J8 f8 f6 {00 I 101 f0 70 ff I 43 48 743 gnua'ntou J. insaeizz, 56 W Peas/cc 4 1d fled/fads April 3, 1928. 1665,l60

s. EINSTEIN ET AL AUTOMATIC SIZE GRINDING MACHINE Filed July 29, 1925 s Sheets-Sheet Patented Apr. 3, 1928.

UNITED STATES PATENT OFFICE.

SOL EINSTEIN, WILLETTS IEASLEE, AND FRED S. HAAS, OF CINCINNATI, OHIO, AS-

SIGNOBS, BY MESNE ASSIGNMENTS, T CINCINNATI GRINDERS INCORPORATED, 0F

CINCINNATI, OHIO,

A CORPORATION OF OHIO.

AUTOMATIC SIZE-GRINDING MACHINE.

Application filed July 29, 1925. Serial No. 46,818.

lhis invention relatesto improvements in grinding machinery and more particularly to what is known as precision grinding machinery such as is normally employed for the production of accurate cylindrical work. Machines of this type are primarily advantageous in the quantity production of similar workpieces accurateto within a fractional thousandth of an inch. In their construction and operation there are two points which are of prime importance. One of these points is that of accurate construction and operation of the machine so that there will be minimum of chatter or vibration and the other is the provision of control mechanism of simple but efficient character which will permit of reduction to a minimum of the time lost in gauging the size of the work or re-setting the machine for different work-- pieces.

It is the purpose of the present invention to provide a machine which is an improvement over the structures of the prior art primarily in the matter of control of operation thereof so that the various necessary movements of the arts of the machine prior to, during and sdbsequent to the grinding operation may be accomplished in the simplest and most eflicient manner.

A further object of the invention is the provision of automatic mechanism adapted to co-act with the workpiece whereby the,

operation of the machine will be a variable matter depending on the actual stock removal rather than a so-called automatic operation dependent upon'the setting of certain mechanical stops or the like having reference only to the movements of the machine and not to the condition of the work itself. F

A further object of the invention is the elimination of waste time in movement of the parts from inoperative to operative position and the reverse.

Further objects of the invention include a simplificationof the methods of operating a machine of this type and of the mechanical elements for accomplishing the foregoing results substantially as hereinafter shown and described and it will be understood that any modifications may be made in the specific structural details illustrated within the scope of the appended claims without departing from or exceeding the spirit of the invention.

Figural represents a front view of a machine embodying the invention.

Figure 2 is a section view on, the line 2-2 of Figure 1.

Figure 3 is a section on the line 3-3 of Figure 2.

Figure 4, is a section on the line H of said figure.

Figure 5 is av section on the line 5-5 of Figure 2.

Figure Figure 2.

Figure 7 is a fragmentary view of the feed mechanism clutch, and

6 is a section on the line 66 of Figure 8 is a diagrammatic view of the electric control. circuits.

In the .drawings in which similar characters of reference are employed to denote corresponding parts throughout the several views, the numeral 15 designates the bed of a grinder having the longitudinally extending ways 16 for the table 17. The bed is further formed with ways 18 for the grinding wheel carriage 19. This carriage has the bearings 20 for spindle 21 bearing the grinding wheel 22. A feed screw 23 rotatably engaged'innut 24 of the carriage is rotatably supported in bracket 25 on the bed 15. Rotation of this screw, impart an in and out or feeding and retracting movement to the carriage 19. Such movement is imparted to screw 23 through the chain ofgears 26, 27 and pinion ,28, the latter being carried by the feed-controlling shaft 29 which extends to the front of the machine. A handwheel 30 is connected through gear box 31 with the shaft 29 for therefore, serves to v manual actuation thereof in a conventional manner, one form of such mechanism'being shown in co-pending application Serial Number 715,860. This mechanism is so geared down both through the gear box 31 and through the pinion and gears 28, 26 and 27 that a complete rotation of the handle will be equivalent only to a single turn of the feed screw with the result that the carriage and grinding stone may be advanced by frac tions of a thousandth of an inch to most accurately regulating the amount of material removed. Necessarily this results in a very slow movement of the stone carriage and ordinarily considerable loss of time in backing off the wheel from a position where the work is completed to position to receive a new workpiece and in again bringing the stone into grinding relation to the new workpiece. As a part of this invention, therefore, certain mechanism which will be hereinafter I described has been provided to obviate these I tached motor 35.

prior art difficulties.

Referring first, however, to the normal operation of the machine, a workpiece 32 is clamped in position between the headstock 33 and tailstock 34, the headstock bein suitably driven to rotate the work as y at- In order that the feedmay be constant, uniform and automatic, power mechanism is employed for imparting a relative feeding movement to the work and grinding member. In the present instance this feed is shown as a movementof the grinding member but it will be understood that the same result could be accomplished by a corresponding inward movement of the work, these two, broadly considered, beingequivalents and therefore equally -fall ing within the scope of the present invention. This power mechanism comprises pri marily the motor 36 suitably secured to the bed 15 and having the motor pinion 37 op-' ,erating through gear 38, worm 39, and

wormwheel or gear 40 to drive the power or driving shaft 41. This shaft is of tubular form having integral therewith gear 42 and a clutch portion 43. Gear 42 is in constant mesh with large gear 44- of the back gear unit 45 having the reduction gear 46. R0- tatable within the tubular power shaft 41 is driven shaft 47 on which is slidably keyed spool 48 having clutch portion 49 and gear portion 50 respectively adapted for selective engagement with clutch face 43 or reduction gear 46. Shift lever 51 engages spool 48 and is movable by in and out sliding of a manually controllable member 52 to reciprocate member 48 from an intermediate neutral position into an interclutched direct drive from member 41 or a reduced speed drive therefrom through the gears 46 and 50.

Pivotally connected with the bed at 53 is bracket 54 having journaled therein the stubshaft 55 having worm portion 56 meshable with the worm-gear 57 on shaft 29. A

4 universal joint 58 co-axial with pivot 53 rotate same.

connects shaft 55 with shaft 47. By comparison of Figures 3 and 7 it will be understood that when bracket 54 is in raised position parts 56 and 57 will be in driving engagement while'when the bracket is in dcpressed position as indicated in Figure 7 the worm 56 will be moved out of engagement with the wormgear and no longer operate to The bracket is formed with a depending socketed lug 60 receiving the plunger '61 outwardly actuated by spring 62 but capable of inward yielding movement.

ward to mesh worm 56 with gear 57. This swinging movement of the bracket and thus the meshing of the parts is limited by the adjustable stopscrew on the bracket contacting with a portion of the bed as indicated in Figure 3. Further movement of the cam therefore serves simply to compress spring 62. To normally maintain the cam in this position, spindle 65 is further provided with arm 71 forengagement with the solenoid 72. As a result, the parts once having been shifted into this position, they will be so held until either manually released or automatically released by interruption of the solenoid circuit de-energizing same. While so held power applied by motor 36 will serve through the chain of gearing just described to rotate feed shaft 29 at a relatively rapid rate of speed when handle 52 is drawn outwardly to throw clutch parts 43 and 49 into engagement or at a much slower or normal feeding speed when the drive is through the back gear unit 45 and gear 50. On de-energizing of the solenoid, retaining arm 71 will dro downward carrying with it cam 64 and t e parts will move out of mesh as indicated in Figure 7.

The electric control circuit includes the current leads 73 and 74 from either the main source of supply as indicated or from an auxiliary source, of supply. These leads normally" energize the solenoid 72. In addltion, however, there is provided the shunt circuit including lead 75 and 76, resistance 77 and contacts 78 and 79. One of these contacts, as 78. is held in fixed position with" respect to the table 17 while the other is carried by the pivoted feeler member 80 having a contacting point 81 riding on the work. The action is such that as thesize of the work is decreased the contacts 78 and 79 will approach each other and will finally close the shunt circuit 75-76. As the resistance of this circuit is less than that of the solenoid the solenoid will then become deenergized releasing arm 71 so that worm 56 will be disengaged and the inward feed of stone and work will cease. It is to be understood that the feeler mechanism and contact just described is adjustable for varying sizes of work, this mechanism being shown and claimed in detail in co-pending application Serial No. 46,816.

In a mechanism of this character it is clesirable that the work and tool or grinding wheel be separated at the completion of the grinding operation. The present invention contemplates" the automatic separation of the parts a pre-determined amount at the conclusion of the said movement when the work has been brought down to proper size. Also the invention contemplates this removal being effected as respects the final position of the operative surface of the tool so that this surface may bea known distance away from a subsequent standard workpiece at the inception of the grinding operation irrespective of the amount of wear of the tool during the previous grinding. Emphasis is placed on this point as differentiated from a definite reverse movement of the carriage through reverse rotation of the handwheel as has been possible with prior-art constructions. This distinction is raised for the reason that with prior-art constructions a definite reverse rotation of the controlling means is true moves the carriage back a pre-determined amount, but as the stone wears away at each cutting the same initial position of the handle would not be satisfactory for rapid re-adjustment to grinding position with a new workpiece but calculation and allowance would have to be made for the wear which has taken place. With the present mechanism, however, as the withdrawing movement is calculated for a definite number of a thousandths of an inch from proper operating position, corresponding for example to a complete turn of the manual feed wheel,

' the operator knows that it is safe to make this single turn of the wheel in bringing back the grinding carriage and that such movement will neither bring the tool against the work with undue force nor will it leave the tool such a distance fromthe work that appreciable time will be consumed in-the automatic taking up the remainder of the distance before grinding starts. 'In the attainment of these results there is mounted on shaft 29 the drum 181 having the clutch face 82 for co-operation with a second clutch face 83 formed on gear 57. These two clutch faces are yieldingly urged into engagement one with the'other by spring 84 mounted on the shaft between drum 181 and fixed collar85 of the shaft. This connection, therefore, yieldable coupling between the parts. Secured to the drum and adapted to be wound thereon by feeding rotation of shaft 29 is the flexible connection, or chain 86* running over idler 87 and having securedxto its free end the gravity actuated weight device 88. This member 88 movesin the tubular guide or dashpot 89 and has its upward movement limited by the adjustable guide bracket 90 which is slidably secured to member 89 as by the bolts 91. The adjustment of bracket 90 definitely checkin the upward movement of the weight 88 aTso limits the winding provides amovement of drum 181 as actuated by the yielding engagement of the parts 82 and 83. If, therefore, additional feeding rotationbe applied to member 29 beyond that necessary to wind the chain or flexible cone nection 86 and bring parts '88 and 90 intov engagement as shown in Figure 6, the additional movement will be inade without rotation of the drum. The feed can thus be indefinitely continued. On the other hand when the worm 56 disengages gear 57 shaft 29 is free to reversely rotate. The force of spring 84 being sufficient to hold the drum locked to the gear 57 and the weight or equivalent pull on member 86 being sufficient the member 29 will be reversely rotated by the unwinding act-ion of the drum moving the tool and work a definite distance apart which is entirely independent and irrespective of the indefinite feeding movement previously imparted thereto.

It has previously been mentioned that the headstock is suitably driven by motor 35 to rotate the work during grinding. At the completion of grindin operation it is desirable that this rotation be automatically stopped so that the work maybe immefront of the machine allowing it to move into inoperative position ready to be again shifted to start the parts when the old workpiece has been removed. The lever 93 is so positioned that therocking movement 1mparted thereto by cam 92 during 1ts winding movement will in no wise affect any of the'other mechanisms of the machine.

It is to be understood that in'- grinding operations of the sort here involved the grinding wheel may in some instances be.

of sufiicient width to cover the entire length of the article being 0 erated upon while in another instance the ength of the article is greater than the width of the wheel so that it is necessary to relatively reciprocate the parts during grinding. For this reason the table 17 has been shown as mounted on ways 16. In addition the table isprovided with a rack 96 engaged by shift pinion 97 on spindle 98. This spindle has at its lower end the double faced gear 99 resting on the pair of beveled gears 100-101 rotatably supported on shaft 47. Each of these gears is provided with a clutch faceas at 102 for selective engagement by the terminal clutch portions 103-104 of the clutch spool keyed on shaft 47 for sliding movement relative thereto. A shifter yoke 106 engages the spool and is operable through suitable linkage from the front of the machine by means of handle 107. This handle may be shifted from side to side to place the spool in either neutral position as shown in Figure 3 or to mesh witheither of the bevel gears and thus impart a driving motion to said gears and large gear 99 and the rack and pinion mechanism to shift the table in one direction or the other. It will be noted the speed of rotation of spindle 98 and thus of table driver depends on whether the shaft 47 is being directly driven or is being driven through the reduction back gear Dogs 108 on the table may be employed in the customary manner to engage the lever 107 and thus automatically reverse the direction of travel of the table during the grinding operation.

In the event that it is desired to manually shift or position the table irrespective of the actuation of the power mechanism, spindle 109 journaled in suitable bearings 110 on the bed has at one end a pinion 11] meshing with the opposite face of the double beveled gear 99 and at its other end sritable sprocket connected by the chain 112 with a second sprocket operatively associated with thehandwheel 113 whereby rotation' of this wheel Will actuate pinion 111 to shift the table in one direction or another as desired.

From the fore oing description taken in connection with t e accompanying drawings the construction and operation of the present machine should be readily understood.

It will be noted that means are provided by which the position of the table longitudinally of the bed may be manually varied and that the distance between the work table and work may also be manually adjusted to initially position the parts as desired. In addition a single power mechanism may be employed which may be selectively coupled with either the table shifting or the feed mechanism or with both to positively actuate said part-s.

It will further be observed that automatic means have been provided for checking the feeding movement when the work has been reduced to a-pre-determined size and that in connection with such automatic size controlling mechanism there are additional automatic means for withdrawing the tool or grinding member from work-engaging position a definite and prescribed amount and inadditionautomatic means for stopping the rotation of the workpieceafter the tool has been withdrawn a suflicient amount to avoid any possibility of production of flats on the workpiece.

We claim- 1. An automatic grinding machine ineluding a bed, a work support, and a tool carriage mounted on the bed, means for a relatively shifting said parts on the bed in a direction one toward the other, work controlled means for limiting their approach, and means for causing a definite separation of the tool and surface produced on the work by the tool irrespective of the previous relative advance, of the parts.

2. A grinding machine including a bed, a Work support and a grinding wheel carriage on the bed, means for shifting the carriage toward and from the support in cluding a source of power, manually shiftable means for variably connecting the shifting mechanism with the source of power to control the rate of movement thereof,

additional automatically operated mechaq nism for disconnecting the shifting mechanism and source of power, and Work-engagmg means for controlling the operation of said automatic device.

3. A grinding machine including a bed, a work support carried thereby, a [001 carriage movable toward and from the support, a rotatable member controlling the movement of the carriage relative to the work support, a positive actuating mechanism therefor, a drum, a yieldable coupling between the drum and shifting mechanism, and means for imparting a reverce rotation to the drum to withdraw the carriage.

4. A grinding machine including a bed, a. work support on the bed, a tool carriage on the bed, means for applying relative feedmg and withdrawing movements to said parts, said means including a rotatable feed device, means capable of positive connection therewith for applying feed movement thereto, and additional means yieldably coupled therewith for applying a limiting reverse movement to said rotatable member when the feeding force is disconnected therefrom.

5. A control device for the return movement of a grinding wheel carriage including a drum frictionally coupled with the feed mechanism of the carriage, a memberwindable on the drum, means limiting the amount of winding movement thereof, whereby the frictional coupling will permit a slippage of the parts if the determined winding action has occurred, and means and frictionally connected thereto for rotation therewith but capable of slippage relative thereto, means for limiting the rotation of the drum with said feed mechanism in one direction, and means for applying a definite amount of reverse rotation to the drum, the force of said reverse power being less than the frictional resistance of the coupling whereby the drum will be reversely rotated only when the rotatable feed member is free for movement therewith.

7. In a grinding machine, the combination with a movable grind stone carriage, of means for shifting the carriage to feed the stone toward the work including a rotatable member, a flexible connection windable on said rotatable member by feeding rotation thereof, and means for applying an unwinding force to said flexible member to produce a reverse or non-feeding movement of the wheel carriage.

8. In a return mechanism for a grinding wheel carriage, the combination with a rotatable carriage shifting member, of a drum yieldably coupled for rotation therewith, a flexible member windable upon the drum, adjustable means for limiting the amount of windin movement thereof whereby slippage 0 the coupling will compensate for additional movement of the rotatable member, and means exerting an unwinding tension against the flexible member whereby the rotatable carriage-shifting device is reversely operated in amount equal to the winding of the flexible member on the drum.

9. In mechanism of the character described, the combination with a bed, of a power shaft journaled in the bed, a transmission line including a worm gear, a bracket pivotally supported adjacent the power shaft, a worm shaft journaled in the bracket and adapted to mesh with the worm gear in the transmission line, a universal joint connecting the worm shaft and power shaft, a positive stop limiting the movement of the bracket and worm shaft in the direction of the worm gear, yielding means resiliently holding the parts against said stop, and a manually operable cam engaging said yielding means for shifting the parts into engaging position. A

10. In mechanism of the character described, the combination with a bed, of a power shaft journaled in the bed, a transmission line including a worm gear, a bracket pivotally supported adjacent the power shaft, .a worm shaft journaled in the bracket and adapted to mesh with the worm gear in the transmission line, a universal joint connecting the worm shaft and power shaft, a positive stop limiting the movement of the bracket and worm shaft in the direction of the worm gear, yielding means resiliently holding the parts against said stop, a manually operable cam engaging said yielding means for shifting the parts into engaging position, and an electrical retaining device for securing the parts in engaged relation.

11. In mechanism of the character described, the combination with a bed, of a power shaft journaled in the bed, a transmission line including a worm gear, a bracket pivotally supported adjacent the power shaft, a worm shaft journaled in the bracket and adapted to mesh with the worm gear in the transmission line, a universal oint connecting the worm shaft and power shaft, a positive stop limiting the movement of the bracket and worm shaft in the direction of the worm gear, yielding means resiliently holding the parts against said stop, a manually operable cam engaging said yielding means for shifting the parts into engaging position, an electrical retaining device for securing the parts in engaged relation, and a work-engaging member coupled with said electrical retaining device for causing release of the cam on prescribed reduction of the workpieces.

SOL EINSTEIN. W'ILLETIS PEASLEE. FRED S. HAAS.

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