US3492697A

US3492697A - Rotational casting apparatus

Info

Publication number: US3492697A
Application number: US729725A
Authority: US
Inventors: Alden C Boyce
Original assignee: Rota Matic Inc
Current assignee: Rota Matic Inc
Priority date: 1968-05-16
Filing date: 1968-05-16
Publication date: 1970-02-03
Anticipated expiration: 1987-02-03

Description

Feb. 3, 1970 A. c. BOYCE 3,492,697

ROTATIONAL CASTING APPARATUS Filed May 16, 1968 s Sheets-Sheet 1 INVENTOR. AL DE N C. BOYCE BY ATTORNE Y5 Feb. 3, 1970 A. c. BOYCE ROTATIONAL CASTING APPARATUS Filed May 1968 Q 5 Sheets Sheet 2 a 9 s: I 8 a T r T R -m \V- 3 v INVENTOR;

ALDEN C. BOYCE filflms wm AT TORNEYS Feb. 3, 1970 A. c. aovcs ROTATIONAL CASTING APPARATUS 5 Sheets-Sheet 5 Filed May 16, 1968 IIOVOLT l Cl il CRI RESET NIOI Q MOLD 1 ROTATE OR! I INDEX STOP FIG. 3

INVENTOR. ALDEN C. BOYCE ATTORNEYS Feb. 3, 1970 A. c. BOYCE 3, 7

ROTATIQNAL CASTING APPARATUS Filed May 16, 1968 5 Sheets-Sheet 4 CRI CRI I r [-1 E I V L l I l INVENTOR ALDEN C. BOYCE BY AT TOR NEYS Feb. .3, 1970 A. c. BOYCE I ROTATIONAL CASTING APPARATUS 5 Sheets Sheet 5 Filed May 16, 1968 FIG. 5

INVENTOR. ALDEN C. BOYCE ATTORNEYS United States Patent Ofitice 3,492,697 Patented Feb. 3, 1970 Int. Cl. 1829c /04 US. Cl. 155-26 7 Claims ABSTRACT OF THE DISCLOSURE A rotational casting machine having an inner shaft and an outer sleeve, coaxial with the inner sleeve, are provided with a gear box assembly being operatively secured to the outer sleeve for rotation therewith. A mold carrying spindle is journalled in the gear housing and is positioned on an axis perpendicular to the inner shaft which engages the spindle for rotation thereof on its own longitudinal axis. Cam and switch means are associated with the outer and inner shafts for controlling rotation thereof to stop the outer sleeve with one end of the mold carrying spindle being uppermost whereby molds secured thereto are substantially horizontally positioned for mold opening, article removal and mold filling action. The mold carrying spindle and outer sleeve are provided with controlled rotation through 180 for again positioning molds horizontally for opening, article removal and refilling action.

The present invention relates to rotational casting apparatus wherein a plurality of molds are adapted to be positioned in the apparatus and be rotated simultaneously at controlled speeds on major and minor axes positioned at 90 with relation to each other.

Heretofore, there have been many different types of rotational casting machines provided and certain of these machines have had some appreciable commercial acceptance. However, these machines are relatively expensive, and complex in mechanical construction.

Another problem encountered in most rotational casting machines with which I am familiar is that it is difficult, if not impossible, to stop rotation of the mold carrying shaft with the molds thereon in proper positions for mold opening and article discharge action and in many instances, one mold spindle must be manually rotated for proper mold positioning for recharging the mold and removing articles therefrom.

It is the general object of the present invention to provide a relatively uncomplicated, sturdy type f rotational casting apparatus which is adapted to have a long service life with a minimum of maintenance thereon.

Another object of the invention is to provide special control circuits in rotational casting apparatus whereby the rnOld carrying spindle in the apparatus can be stopped in a vertical position with one end thereof uppermost to position the molds thereon in substantially horizontal positions, and then to provide substantially 180 rotation of such mold carrying spindle on the major axis of rotation to position the other end of the mold carrying spindle uppermost to present the molds associated therewith in horizontal position for opening, article discharge and mold recharging action.

A further object of the invention is to provide a novel .mold positioning spindle in a rotational casting apparatus and to rotate it at any suitable speed in either direction as desired.

starting and stopping action on the drives therefor readily and to terminate the outer mold spindle drive in a predetermined manner.

The foregoing and other objects and advantages of the invention will be made more apparent as the specification proceeds.

Reference now is made to the accompanying drawings, wherein:

FIG. 1 is a diagrammatic plan view of apparatus em bodying the principles of the invention;

FIG. 2 is an enlarged fragmentary vertical section through one rotary spindle assembly of the invention and associated apparatus of the structure shown in FIG. 1;

FIG. 3 is a diagrammatic view of the wiring diagram for the controls of the invention;

FIG. 4 is a fragmentary diagrammatic view of the wiring details of portions of the motor control circuit for the outer shaft; and

FIG. 5 is a fragmentary diagrammatic view of a portion of the circuit control for rotation of the inner shaft of the apparatus.

When referring to corresponding members shown in the drawings and referred to in the specification, corresponding numerals are used to facilitate comparison therebetween.

With reference to the details of the structure shown in the accompanying drawings, a rotational casting machine of the invention is indicated as a whole by the numeral 10. This machine 10 includes a support column or post 11 that has a turntable 12 operatively associated therewith. Only a portion of the frame 13: for the machine 16 is shown, and the machine includes a plurality of mold support means, or arm assemblies 14, 15", 16 and 17 that are operatively carried by the turntable 12 and normally extend radially therefrom. The machine 10 is shown as having an oven 18 with suitable heat supply means 19 connected thereto operatively associated with the frame 13 to receive a pair of the mold support means therein at all times for heating, curing or setting up the materials carried in the molds in the mold assemblies by heat while the mold carrying means are being rotated in the oven 18. A cooling station or enclosure 20 also is provided in the machine and one of the mold support means or assemblies is operatively positioned in such cooling chamber for enclosure 20 at all times. Suitable arcuate movement of the turntable 12 is provided whereby it is adapted to be indexed through operative stages of so as to position the mold support means in predetermined arcuate relationships to the frame 13 and support column or post 11. The mold carrying arm 14 in FIG. 1 is shown at the mold opening and loading station of the apparatus and one such arm is stopped by indexing action at such station at each increment of indexed movement.

In FIG. 2, the details of one typical mold support means 14 are shown and such means includes an outer sleeve 25 which is journalled in a pair of bearings 26, positioned in radially spaced housings 26a carried by the turntable. Only one bearing and housing is shown in the drawings. Such sleeve 25 is hence positioned for rotation on its longitudinal axis which is considered to be the major axis of rotation for the molds carried by the machine 10, as hereinafter described. This outer sleeve 25 has a conventional drive means, such as a sprocket 27 secured thereto, and a chain or equivalent drive means 28 connects to the sprocket 27 and connects to a drive motor 71 which comprises a DC. adjustable speed motor for controlled drive of this outer sleeve 25, as hereinafter described.

An inner shaft 30 is journalled within the outer sleeve 25, as by bearings 31 and 32 and the ends of the inner shaft 30 protrude from the outer sleeve at each end thereof. A sprocket 33 or equivalent member is secured to the radially inner end of the shaft 30 and a drive chain 34 or equivalent means connects thereto and extends to a conventional adjustable speed DC. motor 72 for controlled speed drive of such inner shaft 30 which is adapted to rotate the molds in the machine of the invention on the minor axis, as hereinafter described in more detail. This outer sleeve 25 protrudes radially beyond the turntable 12 and a gear housing 40 is secured to the radially outer end thereof in any conventional manner. The gear housing 40 is of any desired shape and it is assembled from conventional means such as a plurality of members including plates 41, 42, 43 and 44 as shown in the drawings, and with such plates, being suitably secured together by cap screws 45, or equivalent means. FIG. 2 of the drawings best shows that a pair of the plates 42 and 44 have a mold support spindle 46 journalled therein by bearings 47 and 48. The drawings show that such mold support spindle is positioned on an operative axis at right angles to the longitudinal axis of the outer sleeve 25 and such mold spindle axis is indicated by the line AB and is the minor axis of rotation in the machine while the outer spindle or sleeve axis C-D is the major axis of rotation of the mold support spindle 46 and obviously of any means carried thereby.

The drawings indicate that a bevel gear 50 is secured to the radially outer end of the inner shaft 30 and it engages with a companion bevel gear 51 that is secured to, or preferably formed as a unit with, the mold support spindle 46 intermediate the ends thereof whereby the engagement of the equal size gears 50 and 51 rotates the mold support spindle 46 on its axis A-B when the inner shaft 30 is driven. At the same time, when the sprocket 27 is driven, then the outer sleeve 25 causes the entire gear housing 40 and the mold support spindle 46 positioned therein to be rotated on the major axis C-D, whereby a multi-plane rotation is provided for any molds secured to

ends

52 and 53 of the mold support spindle. These mold spindle ends can have any desired construction and a mold support means, indicated as a whole by the numeral 54, can be attached thereto for positioning one or more molds therein in any desired manner.

It will be realized that any desired types of controls can be provided to provide the usual automatic indexing action and movement of the turntable 12 and with the outer sleeve 25 and inner shaft 30 being continually driven as the turntable 12 moves one of the mold support means through an operative are into the oven 18 and into the cooling station or chamber so as to set up and fuse the article producing material inserted into the molds and to prepare the molds in the machine for mold opening action at the mold unloading station.

However, special controls are provided in the apparatus of the invention for certain features of operation of the present apparatus.

In the apparatus as shown, when drive is terminated for the inner shaft 30, normally a dynamic braking action is applied to the electric motor powering such shaft. Thus when the outer sleeve continues to be driven, there will still be a drive of the spindle 46 on the minor axis A-B of the machine through the gears 50 and 51 and with such rotation on the axis A-B being on a 1 to 1 ratio to the drive of the outer sleeve 25. Normally, if both the inner shaft and the outer sleeve 25 are being driven in the same direction, then the drive of the inner shaft 30 is cumulative in relation to the drive of the outer sleeve 25 in relation to the number of rotations provided for the mold carrying spindle 46 on its longitudinal axis A-B. It has been determined that it may be desirable to have the inner shaft 30 rotated in a reverse direction so that in such instances, the drive of the inner shaft 30 could be equal in r.p.m.s to the drive of the outer sleeve 25, whereby the mold spindle 46 would be held stationary on its minor axis A-B, and the only rotation imparted to molds carried by the mold positioning unit 54 would be the rotation of such means about the major the machine.

Yet other novel controls are provided in the apparatus of the invention and they have a special physical relationship with various components of the machine to provide improved and novel control means for regulating the position of the mold carrying member 54 when the outer sleeve drive is terminated.

FIG. 3 of the drawings shows that power supply leads 60 and 61 are provided in a simplified control circuit for the apparatus and with a main drive motor for the turntable 12 being indicated at 62 and being operatively connected across the power leads 60 and 61 as hereinafter described, while operating coils for relays RR, CR-l, CR-2, CR-3 and CR-4 are indicated respectively by enclosures identified b the

numerals

63, 64, 65, 66 and 166. The individual switches or sets of contacts'controlled by such relays are designated by RR, CR-l, etc., and are shown as normally open or closed. In the energization circuit for the relay 63, a reset button or switch 67 is provided and it is adapted to energize the operating coil of relay 63 and then to lock one set of contacts 68 in a closed position after the reset switch 67 has been temporarily actuated. Hence, the relay 63 is maintained energized as the contacts 63 bridge across the reset switch 67.

In the diagrammatic control circuit shown, for purposes of simplicity and clarity, only one spindle control motor system has been disclosed, but similar means would be provided for the other operative spindles in the machine. Normally, the apparatus will function through an operative cycle by the controls shown in association with other conventional circuit means. The machine is started to operate by temporarily closing an index start switch 69 operatively connected to the operating coil for the relay 64. Such relay energization closes a plurality of switches, or sets of contacts indicated by the numerals 70 in the control circuits for the DC. motor 71 controlling the outer sleeve 25 and its rotation and the second individual DC. motor 72 for the inner shaft is also energized when the relay 64 is energized to close the normally open switches provided in the power circuits for both

motors

71 and 72. Energization of the control relay 64 also closes a set of contacts 73 provided in the power circuit for the operating coil for the control relay 65, so that such relay 65 is now also energized and this closes a set of switches or contacts 74 in the control circuit for the index drive motor 62 whereby the turntable starts to rotate through a given cycle and at the same time, the

motors

71 and 72 are rotating the mold assembly arms and any molds carried thereby in two planes. In the circuit shown, the drive for the motor 62 is terminated when the arcuate movement of the turntable 12 brings it to LS-l or switch 75 at the mold opening station. The switch 75 has been closed when the turntable 12 is started to rotate by the motor 62 and ultimate movement of such turntable to the mold opening station opens the limit switch 75 and closes LS2 or limit switch 76 that is indicated in FIG. 2 of the drawings. Such limit switch 76 is positioned on the turntable assembly and is closed by a cam 176 on the post 11 by relative arcuate movement of the turntable and associated means in relation to the frame 13 as the tumtable moves an arm assembly to the mold open station. By rotation of the outer sleeve 25, still continuing, a lobe of a cam 80 on the outer sleeve is brought into operative engagement with LS-3, or limit switch 77, that is positioned on the turntable 12 is fixed relationship to the outer sleeve 25 and such switch 77 is closed. When the limit switch 77 is closed, this energizes the actuating coil for CR-4 control relay 166, and causes such control relay to open sets of

contacts

81 and 82 and closes the set of contacts 83 provided in the control circuit for regulating the operation of the outer sleeve motor 71, as hereinafter described in more detail. Such action stops the drive for such motor 71.

axis C-D of When LS-2 is closed, rotation of the inner shaft 30 by its drive means causes a lobe of a cam 90 secured operatively to a radially inner end of the inner shaft 30 to contact an associated limit switch LS-4, indicated by the numeral 91, and close it. This energizes the operating coil of CR3, control relay 66. In turn, the control relay 66 causes normally closed sets of

contacts

91 and 92 in the control circuit for the motor 72 to open and at the same time it closes normally open contact 93 provided in the operative circuit or such motor 72 and stops this motor.

By the circuits shown, both

motors

71 and 72 and their control circuits have a dynamic braking action exerted on the armatures thereof by the change in circuit control conditions effected by actuation of the control relays 166 and 66, respectively, whereby such motors will cease rotation with a very limited amount of inertia movement after the control relays 166 and 66, respectively, have been energized.

By adjustment of the position of the cam 80 and the operative lobes or fingers provided thereon in relation to the circumferential positioning of such operative lobes on the circumference of the outer sleeve 25, such inertia travel or limited arcuate movement of the outer sleeve 25 can be regulated so that the outer sleeve 25 will terminate its rotation under the dynamic braking action with the mold support spindle 46 being on a substantially or exactly vertical axis. This enables workers operating the machine to open the mold carrying member 54, remove articles therefrom, and to recharge the mold, close the mold and have the machine ready for further operation. Then, after the molds carried on the upper end 52 of the mold support spindle have been processed, it is desirable to have the spindle 46 rotated about 180 about the major axis C-D of the machine. To achieve this action, a mold rotate switch 100 is temporarily closed and this energizes an operating coil of a control relay indicated by the letters CR and number 101. This opens a normally closed set of contacts 102 in the operative circuit for the control relay 166 and

permits contacts

81 and 82 to reclose and to open the contacts 83 to thus start the outer sleeve motor 71 for rotation of the outer sleeve 25. The limit switch 77 is, as before, opened by such rotation of the outer sleeve as the cam 80 brings an operative lobe into engagement with the limit switch 77 after 180 of rotation to close it, energize the control relay 166 and again cause the outer sleeve motor 71 to terminate its rotation under the dynamic braking action provided. Hence the opposite end 53 of the mold support spindle 46 will be uppermost and the molds carried thereby can be opened, unloaded, and supplied with new article forming material.

In some instances, it is desirable to reverse the rotation, particularly of the inner shaft motor 72. Thus, in the control circuit shown for both the

motors

71 and 72, a forward and reverse type of a conventional switch means 103 and 104, respectively, are provided for the

motors

71 and 72 so that at any time, the operator can reverse the rotation of either one of these motors and have them operating in opposite directions, if desired. The remaining portions of the diagrammatic circuits shown are all of conventional natures and do not need any detailed description. However, by the improved control means of the invention, a controlled stop action is obtained for the outer sleeve and molds carried thereby whereby the mold carrying spindle 46 can be positioned vertically when the drive for the mold support arm 14 is terminated and this spindle 46 will be vertically positioned and can be readily rotated through 180 for complete mold processing at the mold loading and unloading station of the apparatus.

FIGS. 4 and 5 show variable resistances 110 and 111' respectively, which are connected in the field circuits 112 and 113, respectively, for the

motors

71 and 72. Hence, ready speed control means are provided so that any de- 6 sired ratios of drive for the outer sleeve 25 and inner shaft 30 can be obtained.

From the foregoing, it is seen that novel and improved rotational casting apparatus has been provided. Hence, the objects of the invention have been realized.

While one complete embodiment of the invention has been disclosed herein, it will be appreciated that modification of this particular embodiment of the invention may be resorted to without departing from the scope of the invention as defined in the appended claims.

What is claimed is:

1. In a rotational casting machine having a frame, a horizontal turntable journalled on said frame, means for rotating said turntable, and a plurality of mold support means carried by said turntable and extending radially thereof to terminate radially beyond said turntable, and Where said mold support means comprise an outer sleeve,

means on said turntable positioning said outer sleeve for rotation therein,

adjustable speed driven means engaging said outer sleeve to rotate it on a major axis,

an inner shaft journalled in said outer sleeve and extending therebeyond from both ends thereof,

adjustable speed driven means engaging the radially inner end of said shaft,

a first bevel gear secured to the radially outer end of said shaft,

a gear housing secured to the radially outer end of said outer sleeve and enclosing said first gear,

a mold spindle journalled in said gear box on a minor axis perpendicular to that of said outer sleeve and protruding from said gear box at both ends, and

a second bevel gear on said mold spindle within said gear housing and engaging said first gear,

said mold spindle being adapted to have mold carrying means attached to both ends thereof for rotation in a multiplicity of planes with rotation of said outer sleeve and said shaft.

2. In a rotational casting machine as in claim 1 where a 1 to 1 ratio exists between said first and second bevel gears and said outer sleeve will drive said mold spindle on its axis at the same speed as said outer sleeve when said inner shaft is held stationary.

3. In a rotational casting machine as in claim 1 where a 1 to 1 ratio exists between said first and second bevel gears and a DC. motor is provided to drive said inner shaft,

means are provided to reverse the power supply to said motor, and

adjustable resistance means are present in such power supply whereby said shaft can be driven in reverse to retain said mold spindle stationary on its longitudinal axis when said outer shaft and gear housing are rotated to rotate said mold spindle on only the major axis.

4. In a rotational casting machine as in claim 1, where a cam is carried by said outer sleeve,

a switch is secured to said turntable and engages said cam to be actuated thereby at a predetermined position of rotation of said outer sleeve, and

circuit means connect said switch to the drive means for said outer sleeve to terminate drive therefor when said mold spindle is substantially vertical with one end up and any molds operatively secured thereto at the upper end thereof are substantially horizontially positioned.

5. In a rotational casting machine as in claim 4 where additional circuit means connect to said first-named circuit means to actuate said outer sleeve drive means and start rotation thereof, and

said cam actuates said switch a second time after approximately of rotation of said outer sleeve and said mold spindle on the major axis to stop said mold spindle with its other end up.

6. In a rotational casting machine having a frame, a horizontal turntable journalled on said frame, means for rotating said turntable, and a plurality of mold support means carried by said turntable and extending radially thereof to terminate radially beyond said turntable, and where said mold support means comprise an outer sleeve,

adjustable speed and reversible driven means engaging the radially inner end of said shaft,

a mold support spindle operatively journalled on an axis perpendicular to that of said outer sleeve but carried thereby for rotation therewith, said spindle also engaging said inner shaft for rotation thereby.

7. In a rotational casting machine as in claim 6, where a cam is carried by said outer sleeve,

a switch is secured to said turntable and engages said cam to be actuated thereby at a predetermined position of rotation of said outer sleeve,

circuit means connect said switch to the drive means for said outer sleeve to terminate drive therefor when said mold spindle is substantially vertical with one end up and any molds operatively secured thereto at the upper end thereof are substantially horizontally positioned,

additional circuit means connect to said first-named circuit means to actuate said outer sleeve drive means and start rotation thereof, and

said cam actuates said switch a second time after approximately 180 of rotation of said outer sleeve and said mold spindle on the major axis to stop said mold spindle with its other end up.

References Cited UNITED STATES PATENTS 2,681,472 6/ 1954 Rempel. 2,874,964- 2/ 1959 Edwards. 3,095,260 6/1963 Ferriot. 3,112,529 12/ 1963 Chupa. 3,117,346 1/1964 Bertin et al.

WILLIAM J. STEPHENSON, Primary Examiner