US1656537A - Automatic control of centrifugal machines - Google Patents

Description

Jan. 11,1928.

M. D. SMITH ET AL AUTOMATIC CONTROL OF CE NTRIFUGAL MACHINES Filed March 19. 1926 2 Sheets-Sheet l INVENTQRS Mun/w WA M A ORN Jan. 17, 1928.

M. D. SMITH ET AL AUTOMATIC CONTROL OF CENTRIFUGAL MACHINES Filed March 19. 1926 2 Sheets- Sheet 2 INVENTOR 5 Mam /4'8 6M! 7% J.M W

Patented Jan. 17, 1928. I I

UNITED STATES MURPHY 1). SMITH, WALTER MORGAN, AND wItL'IAM-n. MOORE, or BIRMINGHAM,

ALABAMA, Assrenons ".ro SAND SPUN PATENTS CORPORATION, or WILMINGTON, DELAWARE, A coRPonA'rIoN or DELAWARE.

Ao'romAriooonrnor. or CENTRIFUGAL MACHINES.

Application filed March 19, 1926. Serial No. 95,911.

This invention is an improvement incentrifugal casting methods and machines, and more particularly in mechanism for controlling the motor which rotates the mold.

In casting centrifugally in refractory or sand lined molds, by the method set forth in Patents Nos.'1,620,829, 1,620,83Q, and 1,620,- 831, all of-March 15, 1927, the molten metal is charged into a tilted mold, while the mold is rotating at a speed insufficient to hold the metal on the mold Wall bycentrifugal force.

. The longitudinal distribution of the molten metal is attained by the movement of the mold to level position, and this leveling operation may take place at or near the completion of charging, and during the rotation at a relatively low speed.

After the completion or substantial com-. pletion of the longitudinal distribution of the molten metal, the speed of rotation of the mold is abruptly increased to a relatively high rate, sufficient to hold the metal on the mold wall by centrifugal force, thus attaining ci'rcumferential distribution of the metal. f f p In Patent No. 1,620,829, mechanism is shown and described, for operating the controller of the motor, usually an electric motor, by the movement of the mold toward level position. The arrangement is such that just prior to, or at the moment when the mold reaches level position, the controller is operated'to increase the speed of the motor.

However, the moment speed should be initiatedvaries in accordance with many factors, and it is sometimes desirable to delay the initiation of the high speed until after the attainment of the mold .for automatically operating the controller of the motor, initiated by the mold when it attains a predetermined position in its leveling vmovement and completed by the mechanism itself, independent of the mold.

A further object is the provision of means in connection with the said mechanism en- 'ablingthe duration of thechange from low to high to be easily varied, to make the "at which the high change from low to high more or less abrupt. With these and other objects in view the invention consists in the construction and novel combination of parts fully described and minor details of machine construction within the scope of the claims, maybe resorted to without departing from the spirit of the invention.

1,556,531 PATENT OFFICE.

In the drawings forming a part hereof n Fig. 1 is an end view of a part of a centrifugal castingmachine provided with the improved control.

Fig. 2 is an end view of the control.

Fig. 3 is a top plan view of the same.

Fig. 4 is a detail of Fig. 1, showing the control, with the parts in'one' position.

Fig. 5 is an end view of Fig. 4.

The present embodimentof the invention is shown in connection with the tilting carriage l of a centrifugal casting machine, of

the type shown in the last mentioned patent,

the said carriage being pivoted at 2, near one end, to swing. into inclined or substantially horizontal position. The mold indicated generally at 3 is rotatably supported on the carriage, beneath a hood 4, and it is rotated by means of an electrically controlled motor 5, mounted to slide on the carriage toward and from the mold, and coupled to and released from the mold by the said movement,

the coupling mechanism being indicated gen- I erally at 6.

The motor is controlled by a controller indicated generally 'at -7, arranged at the 0nd of the carriage, and the controller shaft 8 has the usual ha'nd operating mechanism therefor. This mechanism which includes a lever 9 and latch mechanism 10 for holding it is adjusted position is coupled to the con troller shaft in such manner that the shaft may move freely in one direction with re spect thereto. The arrangement is such that the controller shaft may rotate freely withspeed up the motor is initiated by the movement of the carriage to horizontal position,

e troller sha t.

as indicated at 13, and one or both of the said ends are removable. A' ball 14 as for instance a cannon ball is arranged within the cylinder. The cylinder may be made from a section of iron pipe of suitable size,

15 and buffers 13 are arranged at the ends, for

engaging the ball'during its movement to be described.

An arm 16' extends longitudinally from the carriage 1, and longitudinally of the controller shaft. The outer end 17 of the arm is hinged or pivoted to the body of the arm as indicated at 18, and the free end of the said outer'end when the. parts are 1n normal position with the carriage tilted lies beneath one end of the cylinder 12, as clearly shown in Fig. 2. An adjustable sto 19 in the form of a set screw, is threaded t rough {the end 17 of the arm, and is adapted to 3 engage the c linder thereby to initiate the U movement 0 viously stated is adjustable, and is held in the same. The stop as preadjusted position by lock nuts as shown,

It will be evident from the description, that when during the leveling movement of 12-" the carriage, the stop 19 engages the cylinder 12, it will move the same a predetermined distance, de ending upon the adjustment of the stop, an the partsare so arranged that at the 'moment when the carriage reaches the selected position in the leveling movement the cylinder will be tilted far enough to start the ball rolling.

The ball 14 normally occupies the position of Fig. 2. That is the ball is in that end of the cylinder which is above the stop 19. The

relative arrangement of the controller shaft and cylinder is such that when the mold is 'rotating at the relatively low speed during charging, the cylinder will be slightly inclined toward the stop as shown in Fig. 2.

\Vhen the stop first engages the cylinder, the cylinder will be moved toward level position, and as soon as it passes beyond level position, the ball 14 will begin to roll. The

5 movement of the ball rapidly accelerates the movement of the cylinder and the corresponding movement of the controlling shaft, and the acceleration increases with much greater ra idit as the ball passes the con he speed of the motor is rapidly increased from relatively low to rela tively high, but in such manner that there is no injurious shock or jar to the parts.

Mechanism is also provided for enabling 66 the time between initiation and attainment of high speed to be varied within nice limits. The said mechanism in the resent instance isof the dash pot type, suc 1 as is used for door checks. This mechanism has the fixed part 20 thereof secured to the base 21 of the controller. The movable part 22 of the check is connected by a link 23 with a radial arm 24 on the controller shaft. The check acts as a brake on the movement of the cylinder 12, and b adjusting the relation between the fixed an movable parts of the check in a usual and well known manner, the extent of the braking action may be varied, thus to vary the duration of the time between the commencement and the end of the movement of the cylinder. After the ball begins to roll, and especially as it passes the controller shaft, the cylinder quickly assumes the JUSltion of Figs. 4 and 5, that is substantially vertical, and an adjustable stop 24 is provided on the controller base for engagement by the cylinder to limit its movement toward the vertical position.

After the mold has rotated at a high speed for a suitable length of time, the speed is reduced, by means of the lever 9, and after the completion of the casting operation the motor is stopped by the same mechanism, to

enable the removal of the mold and casting inder 12 is returned toward the position of Fig. 2, and werethe portion "12 of thearm 16 rigid therewith, the cylinder could not passthe said arm, hence the end of the arm is pivoted as previously described, so. that it may be swungout of the path of the movement of the cylinder, as shown in Figures 3 and 5.

\Vhen a new flask or mold has been placed on the carriage, it is again tilted, and mechanism is provided for returning the pivoted portion of the arm to normal operative position. The said mechanism is a cam bar 26 arranged along side the controlled base. This bar inclines inwardly and downwardly toward the base, and when the pivoted end of the arm engages the same, it will be swung into the full line normal position of Fig. 3. The bar is the hypothenuse of a right triangular frame 27 which is secured in a suitable manner at this point.

In operation, with the parts in the position of Fig. 1, the mold is charged, and durmg charging or after charging, as may be desired, the mold is leveled. At the selected time in the leveling operation, the stop 19 enga es the cylinder 12 and moves the same. The stop is-so arranged that the cylinder will just pass the level position as' completes the movement of the cylinder to the position of Fig. 5, and the rapid rotation of the mold completes the'easting operation. After the mold has rotated at a high speed for a suiiicient length of time the movement is slowed and eventually stopped by the hand lever 9. At the same time the cylinder is returned to the position of Fig. 2, the end 17 of the arm 16 being moved laterally to enable this return movement. When the mold is again returned for another charging operation, the end 17 of the arm is restored to operative position.

The mechanism for moving the controller in a direction to speed up the motor is in the nature of a counterpoise, and is gravity controlled. The said mechanism is normally inoperative, that is whenit is in theposition of Fig. 2, and it is moved into operative position by the carriage, as it moves toward level position, and near the end of such movement. The check, which is an adjustable brake, .enables the movement of the counterpoise under the influence of gravity to be nicely controlled, and the stop 19 enablesthe moment at which the'counterpoise will come into'operativeposition to be predetermined. By the proper regulation, the

mechanism may be brought into operative "position just before the carriage attains the horizontal, at the moment ofsuch attainment, or afterwards, as may .be found desirable. Furthermore by means of the check, the duration of the time required for the controller to move from relatively low to relatively high positions may be nicely determined. That is the transition from, relatively low to" relatively high speed may be made more or less abrupt. The transition may be made practicallyinstantaneous" iftdesired, or there may be an appreciable delay between relatively low and relatively high speed positions. v

What is claimed as new is:

1. In a centrifugal casting machine includinga tilting carriage, a mold rotating motor, and a controller for the motor,

7 mechanism in connection with the controller for moving the same tospeed up the motor,

said mechanism normally inoperative and automatically operating by gravity to move the controller w th accelerating motion from relatively low to relatively high speed posi-- tions when set in operation, and mean s operated by the movement of the carriage into 1e e1 position to initiate theoperation relatively low to relatively high' speed positions when set in operation, means operated by the movement of the carriage into level position to initiate the operation-of said mechanism, and means-in connection with said last named means and adjustable with respect thereto enabling the moment when .said mechanism normally inoperative and automatically operating by gravity to move so the controller with accelerating motion from relatively low to relatively high speedpos'ltions when set'in operation, means operated by the movement of the carriage into level. position to initiate the operation of said mechanism, and. means in connection with said last named means enabling selection of the moment when the speeding up commences, the mechanism including a counterpoisw normally in inoperative position, and engaged by the carri'age near the end of the leveling movement to move said counterpoise into operative position, whereby the counterpoise will complete the operation of the cont-roller.

4. In a centrifugal casting machine in eluding a tilting carriage, amold rotating motor, and a controller for the. motor,

mechanism in connection with the controller for moving the same to speed up the motor, said mechanism normally inoperative and automatically operating by gravity to move the controller with accelerating motion from I relatively low to relatively highspeed positions when set in operation, means operated 1H5 by the movement of the carriage into level position to initiate the operation of, said mechanism, and means in connection with said last named means enabling selection ofthe moment whenth'e speeding up com- 116 mences, the mechanism including a counterpoise normally in inoperative position, en gaged by the carriage near the end of the leveling movement to move said counterpoise into operative position, whereby the counteripoise will complete the operation of the controller, and an adjustable brake in connet tion with the counterpoise to damp the movement thereof. p

5. In a centrifugal casting machine eluding a tilting carriageya mold rotating motor, and a controller for the motor, mechanism in connection with the controller for moving thesame to speed up the motor,

said mechanism normally inoperative and 1 automatically operating/ by gravity to move the controller w1th accelerating motion from relatively low to relatively high speed positions when set in operation, means operated by the movementof the carriagemto level position to initiate the operation of said mechanism, and means in connect on with said last named means enabling selection of the moment when the speeding up commences, the mechanism including a counter-- poise normally in inoperative position, engaged by the carriage near the end ofthe leveling movement to move said counterpoise brake in connection with the counterpoise to damp the movement thereof.

6. In a centrifugal casting .machine including a tilting carriage, a mold rotating motor, and a. controller for the motor, mechanism in connection with the controller for moving the same to speed up the motor, said mechanism normally inoperative and automatically operating by gravity to move the controller with accelerating motion from relatively low to relatively high speed position when set in operation, means operated by the movement of the carriage into level position to initiate the operation of said mechanism, and 'means to vary the duration of the gravity movement of said mechanism.

7. In a centrifugal casting machine including a tilting carriage,a mold rotating motor, and a controller for the motor a normally inoperative counterpoise for moving the controller to speed up the motor, and means operated by the movement of the carriage toward level position and near the end of such movement for moving the counterpoise into operative position.

8. In a centrifugal casting machine including a tilting carriage, a mold rotating motor, and a controller for the motor, a normally inoperative counterpoise for moving the controller to speed up the motor, means operated by the movement of the carriage .toward level position and near ,the end of such movement for moving the counter poise into operative position, and means to regulate the speed of movement of the controller under the influence of the counterpoise.

9. In a centrifugal casting machine in-. cluding a tilting carriage, amold rotating motor, and a controller for the motor, a

- normally inoperative counterpoise for mov- .ing the controller to speed up the motor,

means operated by the movement of the ca 1'- riage toward level position and near the end of such movement for moving the counterpoise into operative position, means to regulate the s eed of movement of the controller under t e influence of the counterpoise, said means includinga dash ot having one member fixed and the ot er connected with the counterpoise.

10. In a centrifugal casting machine including a tilting carria e, a mold rotating motonard a controller or the motor, mech anism in connection with the controller for operating the same to speed up the motor and gravity controlled to accelerate the movement of the controller toward speeding up position, said mechanism normally in operative, means operated by the movement of the carriage into level position to initiate the operation of said mechanism, and means in connection with said last named means and adjustable with respect thereto enabling the moment when the speeding up commences to be changed at will.

11. In a centrifugal casting machine including a tilting carriage, a mold rotating motor, and a controller for the motor, mech anism in connection with the controller for moving the same to speed up the motor, said mechanism normally inoperative and'automatically operating by gravity to move the controller with accelerating motion from relativelyloiv to relatively high speed positions'when set in operation, and means operated by the movement of the carriage into level position to initiate the operation of said mechanism, the controller being freely movable with respect to said mechanism in the reverse direction.

12. In a centrifugal casting machine including a tilting carriage, a mold rotating motor, and a controller shaft for controlling the motor, a normally inoperative counterpoise for moving the controller shaft in a direction to speed up the motor, manually operated means to move the shaft in the opposite direction, means operated by the movement of the carriage toward level position and near the end of such movement for moving the counterpoise into operative position, said means including an arm on the carriage having the outer end thereof in position to engage the counterpoise and swing the same as the arm swings upwards, said arm having a ivoted portion at the outer end thereof to swing out of engaging position with the counterpoise when the counterpoise is restored to inoperative position, and means operated by the movement of the arm when the carriage is tilted to restore the pivoted portion to operative position.

13'. In a centrifugal casting machine including a tilting carriage, a mold rotating motor, and a controller for the motor, normally inoperative gravity controlled mechanism for moving the controller in a.direction to speed up the motor, means operated by the carriage as it nears the level position to move said mechanism into operative position, and means to regulate the speed of movement of the controller under the influence of said mechanism.

14. In a centrifu'gal eas'ting machine in-. cluding a tilting carria e, a mold rotating motor, and a controller or the motor, means operated by the carriage in its movement to duration of time between commencement of the speeding up and attainment of full speed to be varied.

15. In a centrifugal casting machine including a tilting carriage, and a mold rotating motor, means operated by the movement of the carriage into level position to speed up the motor, and means in connection with said last named means enabling selection of the moment in the movement of the carriage when the speeding up will commence.

16. In a centrifugal casting machine ineluding a tilting carriage, and a mold rotating motor, means operated by the movement of the carriage into level position to speed up the motor, means enabling selection of the moment in the movement of the carriage when the speeding up of the motor will commence and means to vary the duration of the time between commencement and the attainment of full speed.

Signed at Birmingham in the county of J efierson, and State of Alabama, this 16th day of March, A. D. 1926.

I MURPHY D. SMITH.

' WALTER MORGAN WILLIAM D. MOORE.

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