US2161465A - Grinding machine - Google Patents

Description

F. S. HAAS GRINDING June 6, 1939.

MACHINE Filed Oct. 2'7, 1937 3 Sheets-Sheet 1 INVENTOR. FREDERICK 5. HM:

ATTORNEY.

June 6, 1939.

F. s. HAAS GRINDING MACHINE s Sheets-Sheet 2 Filed Oct. 27, 1937 INVENTOR. FEEDER/CK 5. HAAS ATTORNEY.

June 6,- 1939. F. s. HAAS GRINDfNG momma 3 Sheets-Sheet 3 INVENTOR. FEEDER/6K 5 IHAAS' Filed Oct. 27, 1937 ATTORNEY.

Patented June 6, 1939 omen GRINDING mcnma 1 Frederick s; um, Cincinnati, out, aasignor a Cincinnati Grinders Incorporated, Cincinnati, Ohio, a corporation of Ohio Application ombu- 27, 19:7, SerialNo. 111,310 a 13 Claims.

, This invention. relates to improvements in grindingmachin'ery of the'centerless typeand has particular reference-to the type of machine illustrated in a United States Letters Patent One of the principal objects of the present invention is the provision in connection with a machine of the type there illustrated of a novel and improved feeding mechanism for presental0 tion oi work piecesto the grinding throat.

A further object of the present invention is the provision of an improved automaticmachine of the magazine typefor continuous operation in controlled grinding of successive work pieces.

A.further object of the present invention is v the provision of a-feed mechanism" embodying improved safety'features for automatically stopplug the machineupon any interference with the proper flow of work through the grinding throat.

Other objects and .advantages of the present invention should *be'readily apparent by referenceto the following specification, considered in conjunction with the accompanying drawings forming-a partthereof and itis tobe understood that any modifications may be made in the exact structural details. there shown and described, withinthescope of the appended claims, without departing from -or exceeding the spirit of theinventionr I a -z Figure 1 is in part -a transverse section and in part an ,elevational view of the work control mechanism at the'grinding throat of the machinexw i 1 wFlgure 2 is a vertical-sectional view taken on the line. 1-10! Figure 1. l v I i .3 is'a sectional view through the synchronized driving mechanism for controllingthe operation of the parts in proper timed sequence.

Figure 4 .ls a fragmentary rearviewillustrating' the end stop and ejecting'mechanism', and Figure 5 is a simplifieddiagram of the. essential electricalcontrolsi'or-themachine.

In the drawings in which simllar characters 0 reference are employed to' denote corresponding parts throughout the several views, numeral l0 designatesthe'bed'of a grinding machine of conventional centerlesstype having rotatably. mountcd thereon at one end thereof a. pair 1 of spaced grinding wheels II laior operation: on th'e terminal to portions. of anv-armatureshaft or rother work 1 piece l2. Disposed in-.:opposition;to thesegrinding :wheelsis a; regulating wheel 1support. 13 mounted for oscillation about a suitable trunnion l4. .Oscillation of thesupport serves, as in u the Patent '.8'I2.4Q5 ev s r eferr t am move the regulatingwheel II in a direction toward and from the grinding wheels ll, pressing an interposed workpiece i2 thereagainst, the work piece riding on the customary work support blade it during this operation. i To eil'ect this movementoi the regulating wheel unit, the member i3 is' provided with an abutment l1 riding on cam it carried by the shaft 19 journaled in bed l0 and bearinga worm gear 20. Worm gear-20 is driven through atrain o1 gearing including worm 2|; worm and worm wheel 12,23 and change gears 24, 25, the latter being mounted on shaft 26 rotated by suitable motor 21. It will thus be seen that the cam is operated at a relatively slow rate of speedand that the amountof its eccentricity and its shape controls the rate and extent of movementof the regulating wheel support foreifecting successive widenings and narrowings of the work receiving throat. I g

To efiect rapid production, it is'desirable that the operator be relieved, as far ,aspossible, of control of the machine and that the work pieces be automatically presentedto and removed from the grinding throat in timed relation to the movements ,of the regulating wheel and 'without necessity of stoppingthe machine betweenvgrindings. a To accomplish this result there is mounted on the bed il adjacent the grinding throata guide chute or hopper 28 to receive the work pieces, this hopper having a lowerlguide 29 for the lowermost work pieces extending substantially into contactwith the proximate end of the work rest blade l6 so that in event of any variance in diameter between the central and terminal portions of the unfinishedwork piece, the same will be properly guided into position on themwork rest blade. r v

Forefiecting transferof the workpiecesfrom the chute oryhopper into the grinding, throat, there is, further mounted on the bed ill abracket 30 vpi -.oviding a guideway ll v:ifor the, slide "32., having an upwardly projecting arm 33. carrying the pusher l4.- It'will-be noted that th pusher}! has been shownas :or sectional formhavlng a removable terminal portion .35 interchangeable for fqper engagement with .difierent types of work pieces,-thus increasing the range of adaptabilityof themachine. it -Slide 32;bears centrally thereofa stud 36pmjecting through slot in. the bracket 3.] and provided with a rollerjt engaged between the iurcations 39 of-rock arm lll. This arm has a hub @l exteriorly. supp f din bracket 42 by suitable anti-friction bearings 43, facilitating free oscillation of the arm. Interiorly, it is keyed to sleeve 44, having clutch disc 45 driven from shaft 46 through discs 41. the parts together for suitable frictional actuation while permitting of slippage between the drive member 46 and arm 46 when resistance to movement of arm 46 exceeds a prescribed amount. Member 46 has positively secured thereto for movement therewith a supplemental rock arm 49 having an arcuate head 56 provided with .a central groove 5I receiving quadrant 52, normaily held inwardly in the slot by spring 53.

Quadrant 52 has the laterally projecting pin 54 riding on the surface of cam 55 carried by clutch plate 45, this cam having an arcuate portion concentric with spindle 46 and an elongated notch or recess 56. So long as the movements of plate 45 and drive member 46 are in phase, pin 54 remains in the recess, but should an obstruction prevent movement of arm 46, the positive drive to member 46 will cause a slippage of the clutch and a consequent relative movement of pin 54- with respect to cam 55. As it is intended that a certain amount of movement may take part at this point without affecting operation of the machine, the pin will for a time ride in the recess, after which, however, it will ride onto the upper face of the cam, moving the quadrant outward. This outward movement reacts on roller 51 of safety switch 56, opening the control circuit of motor 21 and stopping the operation of the machine. An auxiliary manual push button control 59 is provided by which the motor may again be started, it being necessary manually to maintain this contact until the parts are restored to proper phased relation, as before described, when the quadrant will drop back to the position indicated in Figure 1, allowing the manual switch 59 to-cause an automatic continued operation of the machine to be eifected.

It should be apparent that the foregoing structure must be operated by an oscillatory movement and is not, as shown, capable of complete rotational driving as is the cam I6. To effect this movement of arm 46 in cyclically timed re- .lation to the opening and closing of the grinding throat as determined by cam I6, there is secured on the spindle I! of cam I6 a cylindrical or barrel cam 66 engaging pin 6I on reciprocable rack bar 62 having a rack portion 63 meshing with the peripheral teeth or pinion 64 on shaft 65 which transmits motion to the member 46. It will thus be seen that for each rotation of cam I6 there is a corresponding back and forth oscillation of member 62 effected by cam 66 and, therefore, a corresponding oscillation of ram 46 and consequently of pusher actuated thereby.

It is to be understood that the work pieces drop by gravity into a position ahead of pusher 35 and the cycle is such that when the cam causes a retraction of the regulating wheel, opening the grinding throat, an inward movement or movement toward the right, as viewed in Figure 1, is imparted to the member 35 when the lowermost work piece in the chute 26 will be pushed toward the grinding throat moving ahead of it the completed work piece. work pieces may each' individually be properly positioned in the throat and yet permit of ejection on completion, use is made of the oscillate.- ble end stop 66, resiliently actuated as by spring 61 into the position shown in Figure 1 for engagement with the far terminus of the work A spring 46 serves to hold In order that the piece being operatedupon. As the grinding is completed, however, face cam 66 secured to and movable with cam I6 actuates control plunger 69 of control switch 16 for solenoid II which serves to draw member 66 downward out of the path of movement of the work piece. This then permits the work piece to be moved out of the grinding ,throat, riding over the top of member 66 to an extent that it will by gravity tilt into the trough portion 12 thereof and be discharged from the machine. During continued movement of cam I6, a lower portion thereof is brought into alignment with control plunger 69, allowing the switch to move into position, opening the solenoid circuit when spring 61 will restore the end stop member to limit the movement of the following work piece.

To accommodate any variation in length of work pieces and insure same in all events being properly pressed into engagement with the end stop, bracket 42 is provided with the adjustable stop screws 13 and I4. On the inward or feeding stroke arm 46 is limited in its maximum movement by engagement with screw 13, while the drive effected through rack 62 is preferably a greater potential amount so that a certain counterclockwise slippage takes place in the driving clutch.

correspondingly, this slippage will take place before arm 46 strikes screw I3 in the eventthat it is limited by the response of the work piece against the fixed end stop. Conversely, on movement of arm 46 in a reverse direction it will contact with screw I4 before maximum counterclockwise oscillation of member 46 has been effected, being, therefore, slipped back into its original phased relationship with the member 46 for re-engagement with a proper presentation of a subsequent work piece in the chute or trough 26. As has been pointed out, the length .of notch 56 is such as to permit this slippage without efiecting control switch 51.

In the event that for any reason it is desired to utilize the machine for grinding but a single work piece at a time, either for manual feeding of the work pieces, or for set-up purposes or where it is desired individually to check each work piece before grinding of a subsequent work piece, the cam shaft I9 may be utilized to perform. a double function. In this event a supplemental face cam 15 is terminally secured thereto for cooperation with plunger 16 of switch 'll, serving to move the switch to open the circuit of motor 2'Ipreferably when the regulating wheel carriage is in a maximum retracted position. In this event, an additional manually controlled switch 16 is provided for temporarily closing the motor circuit to restart the cycle of operation of the machine. As will be seen by reference to the electrical circuit diagram, a selector switch I9 is further provided by which the switch 'II may be rendered either effective or ineffective, as respects control of the motor circuit.

From the foregoing description, taken in connection with the drawings, the operation of' the present machine should be readily understood, and it will be understood that there has been provided a machine which may be either manually controllable, semi-automatic or completely automatic in operation, and which will serve satisfactorily to eject completed work ,pieces from the machine, introduce new work pieces, limiting definitely their positioning within the throat, and in which a positively operapotentially impositive movement to the control arm for the work ejecting and injecting device, such that under proper operating conditions, the machine will be completely automatic in performance of the grinding, while in the event of improper work conditions or failure to release of a part, such as the end stop, the machine will be automatically stopped and thus damage to the work or breakage of parts prevented. It will further be noted that there has been provided a mechanism having an inherent slippage capacity, such as positively to insure accurate positioning of work pieces of variable lengths with-- in the machine, which mechanism will be automatically self-restoring during each cycle of operation to normal prescribed position for operation upon properly formed or standard length work blanks.

'I claim: I

1. The combination with a centerless grinding machine including opposed grinding and regulating wheels forming a work supporting throat therebetween, and means for cyclically varying the width of said throat, of means for introducing work pieces within the throat of said grinder in timed relation to the variance in said throat, said means including an oscillatable work shifting device, power actuating means for moving the device in timed relation to the throat varying movement of the centerless grinder, an impositive connection between said power means and the oscillatable member, permitting slippage of the latter with respect to its actuator in the presence of an obstruction, and means responsive to a predetermined slippage for stopping the operation of the machine.

2. In a centerless grinding machine including opposed grinding and regulating wheels and an interposed work rest, means mounting one of said wheels for movement in a direction toward and from the other, means for injecting work into the throat between the wheels during separation thereof and a control mechanism for said parts, including a drive motor, a control shaft rotatable thereby, a first cam means carried by the shaft for varying the effective dimension of the work receiving throat, a second cam means carried by the shaft, an impositive connection between said second cam means and the work injecting mechanism for actuation of the latter, a safety control switch for the motor, and means actuable by out of phase movement between the throat control cam and the work injector for actuating the safety switch to stop the drive motor.

3. The combination with a centerless grinder having opposing grinding and regulating wheels providing a work receiving throat, and means for automatically varying the width of said throat, of means for effecting movement of a work piece in the throat including a cam operable by and in synchronism with the throat adjusting mechanism, a rock shaft oscillated by said cam, a work injector, and a friction couplingbetween said parts for effecting movement thereof with and with respect to each other, a first stop device for limiting the movement of the work injector in a feeding direction whereby slippage in one direction will occur between said member and its actuator, and an additional means for limiting its movement in a reverse direction for restoring same to initially phased relation with respect to its actuator.

4. The combination with a centerless grinder I having opposing grinding and regulating wheels providing a work receiving throat, and means for automatically varying the width of said throat, of means for effecting movement of a work piece in the throat including a cam operable by and in synchronism with the throat adjusting mechanism, a rock shaft oscillated by said cam, a work injector, and a friction coupling between said parts for eil'ecting movement thereof with and with respect to each other, a first stop device for limiting the movement of the work injector in a feeding direction whereby slippage in one direction will occur between. said member and its actuator, an additional means for limiting its movement in a reverse direction for restoring same to initially phased relation with respect to its actuator, a safety device for discontinuing-actuation of the work injector drive, and means for actuation of the safety device when the relative movement of the parts exceeds a prescribed amount. a

5. The combination with a centerless grinder having opposing grinding and regulating wheels providing a work receiving throat and means for automatically varying the width of said throat, of a prime mover, means for effecting movement of a work piece in the throat, a friction safety device, and means operable upon slippage of the safety device beyond prescribed limits for stopp ing the prime mover.

6. The combination with a centerless grinder having opposing grinding and regulating wheels providing a work receiving throat and means for automatically varying the width of said throat, of a prime mover, means for effecting movement of a work piece in the throat, a friction safety device, and means operable upon slippage of the safety device beyond prescribed limits for stopping the prime mover, said means including an electrical circuit, a switch in the circuit opened by said means to interrupt the circuit and additional means exclusive of said switch for completing the circuit to re-establish operation of the prime mover.

7. The combination with a centerless grinder having opposinggrinding and regulating wheels providing a work receiving throat and means for automatically varying the width of said throat. of a primemover, means for effecting movement of a workpiece in the throat, a friction safety device, means operable upon slippage of the safety device beyond prescribed limits for stopping the prime mover, said means including an electrical circuit, a switch in the circuit opened by said means to interrupt the circuit and additional means exclusive of said switch for completing the circuit to re-establish operation of the prime mover, and automatically operable means for effecting reverse slippage of the safety device to restore the first-mentioned switch to circuit completing position,

'8. The combination with a centerless grinder having opposed grinding and regulating wheels providing a work receiving throat, of work feeding and grinding controlling mechanism for said grinder including a prime mover, a cam shaft actuated thereby having a first cam portion for effecting contraction andexpansion of the grinding throat, means for introducing and ejecting a work piece as respects the grinding throat, an end stop member for limiting movement of the work axially in the throat, electrically operated a positioning of said switch.

9. The combination with a centerless grinder having opposed grinding and regulating wheels providing a work receiving throat, of work feeding and grinding controlling mechanism for said grinder including a prime mover, a camshaft actuated thereby having a first cam portion for effecting contraction and expansion of the grinding throat, means for introducing and ejecting a work piece as respects the grinding throat, an end stop member for limiting movement of the work axially in the throat, electrically operated means for shifting said end stop into inoperative position, a control switch for said electrical operated means and an operating member actuable by said cam shaft for determining the effective positioning of said switch, said work feeding mechanism including a pusher device for effecting axial movement of successive work pieces in the direction of said end stop, means on said cam shaft for effecting actuation of said pusher device in timed relation to the throat widening and end stop releasing mechanisms, and a safety device including a power actuable electric switch for eflfecting discontinuance of actuation of the cam shaft when resistance to movement of the pusher exceeds a predetermined amount.

10. The combination with a centerless grinder having opposed grinding and regulating wheels providing a work receiving throat, of work feeding and grinding controlling mechanism for said grinder including a prime mover, a cam shaft actuated thereby having a first cam portion for effecting contraction and expansion of the grinding throat, means for introducing and ejecting a work piece as respects the grinding throat, an and stop member for limiting movement of the work axially in the throat, electrically operated means for shifting said end stop into inoperative position, a control switch for said electrical operated means and an operating member actuable by said cam shaft for determining the effective positioning of said switch, said work feeding mechanism including a pusher device for effecting axial movement of successive work pieces in thedirection of said end stop, means on said cam shaft for effecting actuation of said pusher device in timed relation to the throat widening and end stop releasing mechanisms, a safety device including a power actuable electric switch for effecting discontinuance of actuation of the cam shaft when resistance tomovement of the pusher exceeds a predetermined amount, and means exclusive of said switch for re-establishing power actuation of said shaft.

11. In'a machine of the character described,

a work shifting mechanism including a prime mover, a rock shaft actuable thereby, a plunger, means for transmitting movement from the rock shaft to the plunger including a slip clutch, the amplitude of oscillation of the rock shaft exceeding the angular amplitude of potential movement of the plunger, whereby slippage will take place at each power oscillation of the'rock shaft, means for re-establishing initial phased relationship of said parts during each complete oscillatory stroke, and means actuable by excessive relative slippage of the parts as when an unwarranted obstruction unduly limits movement of the plunger for stopping the oscillation of the shaft.

12. In a machine of the character described, a work shifting mechanism including a prime mover, a rock shaft actuable thereby, a plunger, means for transmitting movement from the rock shaft to the plunger including a slip clutch, the amplitude of oscillation of the rock shaft exceeding the angular amplitude of potential movement of the plunger, whereby slippage will take place at each power oscillation of the rock shaft, means for re-establishing initial phased relationship of said parts during each complete oscillatory stroke, and means actuable by excessive relative slippage of the parts as when an unwarranted obstruction unduly limits movement of the plunger for stopping the oscillation of the shaft, said means including a segmental member movable with the rock shaft, a switch member mechanically interengaged with the segment, and means for radially displacing the segment when the slippage between the parts exceeds a prescribed amount, whereby said radial displacement actuates the switch arm to stop the movement of the rock shaft.

13. A machine of the character described including means providing a variable width grinding throat, means for terminally limiting axial movement of a work piece in the throat, and a control mechanism for cyclically determining the operation of the machine, including a prime mover, a timer shaft driven by the prime mover,

means actuated by the timer shaft for effecting intermittent variations in the width of the grinding throat, a shiftable terminal end stop member for limiting movement of the work in the grinding throat, control means including a solenoid for determining the effective position of the end stop member, means on the timer shaft for determining the energization of the solenoid in timed relation to variance of the grinding throat, a cyclic determinator selectively conditionable to effect uni-cycle or continuous operation of the machine, means on the timer shaft for controlling the uni-cycle mechanism, and means independent of the timer shaft control for initiating a succeeding cycle of operation.

FREDERICK S. HAAS.

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