US2681738A

US2681738A - Mold pallet dumping device

Info

Publication number: US2681738A
Application number: US191874A
Authority: US
Inventors: Axel G Granath
Original assignee: Simpson Herbert Corp
Current assignee: Simpson Herbert Corp; Herbert Simpson Corp
Priority date: 1950-10-24
Filing date: 1950-10-24
Publication date: 1954-06-22
Anticipated expiration: 1971-06-22

Description

June 22, 1954 A. G. GRANATH 2,681,738

MOLD PALLET DUMPING DEVICE Filed Oct. 24, 1950 4 Sheets-Sheet l Axel G. Granaz W ma@ 51412 www June 22, 1954 A G, GRANATH 2,681,738

MOLD PALLET DUMPING DEVICE Filed Oct. 24, 1950 4 Sheets-Sheet 2 June 22, 1954 A. ci, GRANATH MOLD PALLET DUMPING DEVICE 4 Sheets-Sheet 3 Filed Oct. 24, 1950 Inl/E 27222 1 Axe! June 22, 1954 A. G. GRANATH 2,681,738

MOLD PALLET DUMPING DEVICE Filed Oct. 24, 1950 4 Sheets-Sheet 4 E ..5 l() q E??? Hls-l5 Patented June 22, 1954 UNITED STATES ATENT OFFICE MOLD PALLET DUMPING DEVICE Application October 24, 1950, Serial No. 191,874

4 claims. l

larly adaptable for utilization in a foundry or l the like to separately and sequentially dump various portions of a molding assembly, such as a snap mold and a pallet-cart assembly, to separate conveying means. Conventional molding procedures in the mass-production casting of relatively small parts involves the pouring of molten metal into a snap-type mold supported upon a pallet or similar floor which is mounted upon a dump cart movable on conveying rails. After the casting step has been completed and the molten metal has sufficiently cooled, the completed molding assembly is moved to a dumping station where the mold is separated from the pallet-cart assembly so that the casting may be removed and the cart-pallet assembly returned to a subsequent casting cycle.

Manual separation of the molding assembly is undesirable due to exposure of the workman accomplishing the separation to extreme dust conditions and hard manual labor. Various devices have been proposed for mechanically separating the molding assembly, but such devices have typically been quite complicated and expensive in installation and usage. For example, it has previously been necessary to provide a pit for the conveyor means receiving the mold, thus greatly increasing the expense of installation of the mold dumping device. In addition, the mold, in being dumped from the cart, has traveled through a relatively great distance, with the possible consequence of damage to the casting and the mold.

It is, therefore, an important object of the present invention to provide an improved, simple, inexpensive and easily employed dumping device.

Another important object of the present invention is to provide means for separately and sequentially dumping various portions of a molding assembly, the dumping operation being carried out without the possibility of injury to the mold or the casting carried thereby.

It is a further important object of the present invention to provide a means for automatically and sequentially separating a mold from a moldsupporting structure and to return the moldsupporting structure for reuse.

An important and desirable feature of the present invention is the utilization of a dump platform which is tilta-ble about separate pivot points in oppositely directed arcuate paths relative to a support structure, tilting movement of the dump platform being accomplished by power means energizable to move the platform to dumping position and to the pallet return position by pivoted movement thereof.

Another feature of the present invention resides in the provision of a dumping platform having a dumping pivot point which is `well for- Ward upon the dumping platform itself in order to give a short dumping distance preventing injury to the mold or the casting carried thereby. The dumping platform is formed in two separate sections which are pivotal relative to each other to a mold dumping position and which are jointly pivotal relative to the supporting structure `to the pallet returning position.

An additional feature of the invention resides in the self-dumping of the mold when the platform is in dumping position and the self-dumping of the pallet and cart assembly when the dumping platform is placed in its return position.

Therefore, another object of the present invention is to provide an improved dumping device wherein separation of a molding assembly is accomplished by tilting of a dumping platform structure about separated pivot points.

A further object related to that set forth above is the provision of power means to carry out tilting movement of the dump platform.

It is a still further object of the present invention to provide a dumping device including a dumping platform comprising a pair of relatively pivotal sections separably movable to one dumping position and jointly movable to a second dumping position.

Yet another important object of the present invention is to provide a dumping device for separating a mold assembly with the various portions of the assembly being sequentially selfdumping when the dumping device as a whole is actuated to its various dumping positions.

Still another feature of the present invention resides in the provision of a power-operated dumping device movable to a plurality of adjusted positions and provided with resilient means for cushioning the shock generated upon movement of the dumping device to its various positions.

A further feature of the present invention is the provision of a dumping device movable from a central load-receiving position to a first mold dumping position and to a second mold support dumping position, means being provided for indexing the dumping device to its central loadreceiving position upon completion of a dumping cycle. A more detailed feature of the present invention is the provision of means for retaining a mold supporting pallet upon a mold cart during dumping of a mold from the pallet while accommodating simultaneous discharge of the pallet and the cart for return to a molding station.

Other and further objects and features of the present invention will be apparent from the disclosures in the specification and the accompanying drawings.

On the drawings:

Figure l is a side elevational view of a dumping device of the present invention when in its central load-receiving position;

Figure 2 is a side elevational view similar to Figure l illustrating a device of the present invention when in its mold dumping position;

Figure 3 is a side elevational View similar to Figures l and 2 illustrating a device of the present invention when in its return position;

l Figure e is a sectional View, with parts shown in elevation, taken along the planes IV-IV of Fgure l and Figure 5 is a cross-sectional view, with parts shown in elevation, taken along the planes V-V of Figure l.

As shown on the drawings:

In Figure l, reference numeral I refers generally to a mold assembly including a snap-type mold or flask El adapted to contain a body of sand or similar mold-forming material and a casting previously formed within the flask by the introduction of molten metal thereinto. The flask l i is mounted upon a pallet l2 defining the flask bottom board and having transversely extending cleats i3 dening pallet legs for elevating the pallet above a supporting surface.

The pallet l2 is supported upon a dump cart i4 including a pair of spaced, parallel, dependent channel irons I6 supporting a plurality of axles li for rotatably journalling cartwheels I8. As illustrated, four such wheels i3 are provided for supporting the cart for movement of the cart. The cart body portion l carries a pair of spaced transversely extending angle iron supports I9 secured to the cart body and projecting thereabove to contact the undersurface of the pallet l2.

The angle irons i9 are preferably so spaced as to receive the pallet legs i3 therebetween in abutting relation so that the pallet is firmly retained upon the dump cart.

As hereinbefore explained, the mold assembly it is utilized during pouring of molten metal and, after the metal has solidied within the flask l l, the assembly is moved along a conveyor rail by suitable means. A dump platform support having a supporting structure 2l is provided in advance of the end of the conveyor rails 2i) and includes a oor surface 22 and a pair of edge mounted longitudinally extending channel irons 23 carried by the floor surface. The channel irons 23 each carry an upwardly projecting post 2li at the forward end thereof and rigidly attached to the irons 23 through a generally triangular web 25. Each of the upright posts 2s carries at its free ends and contacting opposing edges thereof, a pair of upstanding pivot posts 26 secured to the posts 24 by suitable means, as by bolts and nuts 2l. The pivot posts 26 are further rigidied by an angle beam 28 extending transversely across the width of the platform support 2i and secured to the posts 24 by suitable means.

Each pair of the pivot posts 26 journals there- Cil between a pivot pin 29, and each pivot pin 29 carries an upstanding pivot link 30 at the central portion thereof intermediate the pivot posts 26.

The pivot links 30 are rigidly secured by suitable means, as by welding, to the inner surfaces of the longitudinal members of a generally rectangular lower dumping platform 3l. rihe lower dumping platform includes a pair of longitudinal beams 32 and a plurality of transverse joining beams 33.

The rectangular lower dump platform frame 3i carries adjacent the rear transverse frame member 33 a pair of pivot pins 35 secured to angle beams 3% secured to the frame and receiving the pin 35 therethrough (Fig. 4). The pivot pins are rigidly secured to and carry intermediate their length a depending upper return lever 31 receiving at its free end a pivot pin 33 also received by a lower return lever 39, which in turn is pivoted as at 49 to a pair of brackets lll carried by the floor 22 and projecting upwardly therebeyond. It will be understood that each of the pairs of pivot pins 35 is carried by the frame 3l and that each pin is secured to a return lever assembly fil-lll, respectively. Each of the upper return levers 3i is provided with a transverse stop plate 43 adjacent its free end and adapted to overlie a corresponding edge of the lower return lever 39 so as to accommodate relative pivoting movement of the levers in one direction and to prevent relative pivoting movement in the other direction. Transversely extending rigidifying irons @lde4 are provided between each set of upper and lower levers, 3"!-37 and 39-39, respectively. The lower return lever assembly has pivoted thereto, as at 45, an actuating rod i6 telescopica-Hy received by and adapted to be actuated by a uid pressure, either hydraulic or pneumatic, cylinder 4l. It will be appreciated that the cylinder 41 has in the interior thereof a reciprocable piston which is actuated for movement in either direction by fluid under pressure introduced through fluid pressure conduits 49 connected to a suitable source of fluid. rThe other end of the cylinder il is pivotally secured, as at 49, to an upwardly projecting bracket 59 carried by the base or floor 22.

It will thus be seen that the lowei` dump platform 3l is adapted to be lowered by actuation of the fluid pressure cylinder 4l to cause relative pivoting movement of the return levers 31 and 39. Consequently, the rear end of the lower dump platform will be lowered about the pivot pin 29 which is carried by the upstanding post 2li. The stop plate d3 permits relative pivoting of the return levers 3l and 39 in only one direction so that over-center pivoting of these members is impossible upon retraction of the actuating rod 46. Thus, the return lever assembly serves as an indexing means for retaining the lower platform 3l in horizontal alignment upon retraction of the rod ll-i.

An upper dump platform 5! of generally rectangular configuration but of slightly smaller transverse dimensions than the lower platform 3l is provided to overlie the lower platform. More specifically, the upper dumping platform comprises a plurality of rectangularly arranged frame members 52 carrying adjacent the forward end thereof a depending pivot link 53 which is apertured to receive therethrough a pivot pin 54 carried by the lower dump frame at the extreme forward end thereof. The upper dump platform 5l also carries a pair of depending centrallylocated pivot brackets 55 having a pivot pin 56 extending therebetween. The pivot pin 56 is also received by the extreme end of an actuating rod 5l extending beyond and adapted to be moved by a uid pressure cylinder 58. The cylinder 58 is supported beneath 'the lower dump platform 3| by means of a pair of angled supporting brackets 59 depending from the lower` platform and each vcarrying a pivot pin 6-3 supporting the cylinder 58 therebetween. It will be appreciated that the cylinder 53 of a construction generally similar to that of the cylinder 4'! heretofore described, and that the cylinder has in the interior thereof a reciprocable piston carrying the actuating rod 51 and energized by fluid under pressure admitted to the interior of the cylinder 58 through fluid conduits 6l connected to a suitable source of fluid under pressure.

The rear end of the upper dump platform 5| is supported upon a resilient bumper 62 carried by the lower dump platform and best illustrated in Figure 4. The bumper 62 preferably comprises a plurality of metal or similar rigid plates having one or more layers of resilient material, such as rubber` or the like, interposed therebetween. A similar bumper 3 is secured by suitable means, as by nuts and bolts 5d, to a upstanding standard 55 carried by the base channels 23. The second bumper 53 serves to cushion or resiliently absorb any shock generated upon lowering of the lower platform frame 1l i while the cushions or bumpers S52 serve te cushion any shock generated upon lowering the upper platform 5| to its position in abutment with the lower platform 3 l.

The side members 52 defining the upper dump platform 5i carry at their upper edges parallel upwardly projecting platform rails 55 adapted to receive the double flanged wheels i8 of the dump cart lil. Movement of the dump cart from the xed conveying rails to the dump platform rails 66 is facilitated by joining rails 67 carried at the rear end of the lower dump platform 3i. A dump cart stop 68 is carried by the side members 52 of the upper dump platform 5l to project upwardly therebeyond directly in the path of the wheels I8 so as to prevent rolling of the dump cart from the rails 55.

An additional cushioning of the lower dump platform upon its being lowered to its position of Fig. 3 is obtained by utilization of leaf springs 'Hl secured to the forwardly projecting flange 28a formed on the rigidifyingmember 28 extending between the upwardly projecting posts 24. More particularly, the leaf springs 'l0 are each secured to the member 23 by means of a spring lock bar ll contacting the butt end of the leaf springs and urged thereagainst by nuts and bolts l2.

Actuation of the fluid pressure cylinder 58 to extend the actuating rod 5l beyond its retracted position shown in Fig. 1 will serve to elevate the upper dump platform 5I, this elevating movement being accommodated by the pivot pins 54 located at the extreme forward end of the lower dump platform 3l. The pivoted attachment of the fluid pressure cylinder 58 to the flanges 59 will accommodate pivoting of the cylinder during elevational movement of the dump platform.

Operation The operation of the device will be appreciated from the foregoing description of the drawings. The operation includes, the prior forming of a casting within the flask Il which is positioned upon the pallet l2 and the dump cart I4. The dump cart is trundled or otherwise moved along the stationary conveying rails 20 and the joining rails 61 to a position upon the rails 66 carried by the upper dump platform, substantially as shown in Figure 1. As the next step in the operation, the fluid pressure cylinder 58 is energized to cause the extension of the actuating rod 5?, which in turn causes the elevation of the upper dump platform. Elevation of the dump platform 5i causes pivoting movement of the same about the pivot pin 54 and the relative movement between the upper and lower dump platforms continues until the position of Figure 2 is attained. When the upper dump platform 5i is inclined with respect to the lower dump platform 3l, gravitational forces acting upon the mold assembly lil will carry the assembly forwardly until the dump cart abuts the stop 65. The cart and pallet will be brought to an abrupt halt upon striking the stop 5B, while the flask l l will continue forwardly clue to its momentum so that it will slide easily from the upper surface of the pallet l2. A conveyor C is preferably positioned immediately adjacent the dump platform in a position to conveniently receive the flask and its contents.

It will be noted that the angle irons i3 supporting the pallet l2, by virtue of their Contact with the pallet legs i3, will prevent displacement of the pallet during removal of the flask Il therefrom.

Following removal of the flask ll from the pallet-cart assembly, the power cylinder 53 is again energized to return the upper pallet platform to its original position, as shown in Figure 1. Return of the upper dump platform will bring the platform into abutment with the bumper 62 which will absorb any shock due to contact between the upper and lower platforms.

As a next step in the method, the 'dump cart and pallet are removed from the rails 5t by a lowering of the complete dump platform. As hereinbefore explained, this movement of the dump platform is accomplished by energization of the return cylinder 4l to extend the cylinder actuating arm 45. Extension of the arm 46 `breaks the linkage between the upper and lower return levers 31 and 39, respectively, so that the platform` is lowered to brinCr the joining rails 61 into alignment with a fixed return rail 65, all as best shown in Fig. 3. Due to the inclination of the pallet floor when in this position, and the absence of any obstruction at the rear end of the dump platform, the dump cart and pallet carried thereby will roll freely down the dump platform rails across the joining rails 5l onto the fixed return rails 69.

In this manner, it will be seen that the present invention provides a dumping device whereby a mold assembly may be readily moved from a rst conveying means, namely the fixed conveying rails 20, to a second conveying means, the conveyor C in case of the flask and its contents, and the fixed return rails liti in the case of the pallet and dump cart. The dumping operation is carried out automatically upon energization of the dump platform power means, there is no necessity for any manual manipulation of any portion of the mold assembly during the complete operation.

The function of the leaf springs 'f6 will be appreciated inasmuch as upon return movement of the device, the spring is deflected downwardly and placed under stress, the stressing absorbing a portion of the shock of the lowering of the complete platform. A portion of this shock is also absorbed by the bumper 63. Upon retraction of the actuating arm 46 of the cylinder 41, the leaf springs I0 aid in returning the dump platform to its horizontal position. The leaf springs particularly aid in initial movement of the dumping platform from its completely lowered return position to give a quick recovery, while the stop plate 43 prevents reverse bending of the linkage composed of the return lever arms 31 and 39, thus making the device self-centering in its normal central position.

It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present information.

I claim as my invention:

1. A mold dumping assembly for separating a mold nask from its suporting means and for returning the supporting means to a molding station, comprising a support structure, a lower dumping platform pivoted to said support structure for movement relative thereto, an upper dumping platform secured to said first dumping platform for movement therewith and for pivoting movement independently thereof, power means for effecting independent pivoting movement of said upper dumping platform, means retaining the mold flask supporting means on said upper dumping platform while accommodating removal of said mold flask therefrom, and power means for effecting simultaneous pivoting movement of each of said dumping platforms to discharge said supporting means therefrom.

2. A mold dumping device comprising a supporting frame, dumping means superimposed on said frame and including a lower dumping platform and an upper dumping platform, said lower dumping platform being pivotally attached to said supporting frame and said upper dumping platform being pivotally attached to said lower dumping platform for movement relative thereto, power means for effecting pivotal movement of said upper dumping platform relative to said lower dumping platform, power means for effecting pivotal movement of said lower dumping platform and the upper dumping platform carried thereby relative to said supporting frame, stop means carried by said supporting frame for limiting said last-mentioned pivoting movement, and resilient means interposed between said supporting frame and said dumping platform to absorb the shock generated upon contact between said dumping platform and said stop.

3. A dumping device for selectively transferring different portions of a molding assembly carried thereby to separated first and second conveying means, comprising a supporting frame, a platform including a lower section pivoted intermediate its length to said frame. and an upper section movable with said lower section and also pivoted to said lower section adjacent one end thereof for tilting movement relative thereto in a direction toward the second conveying means, said platform sections being pivotable about the point of pivoted attachment of said lower platform section to said frame toward the second of said conveying means, separate power means operatively connected to said frame sections, respectively, arld selectively energizable to accomplish pivotal movement thereof, and. means carried by the upper of said sections for supporting thereon said molding assembly.

4. In a foundry mold dumping mechanism, a supporting platform structure for a multiple part mold flask assembly and which structure includes stacked relatively tiltable parts, means .for supporting said platform structure in generally horizontal position to receive a mold flask assembly, means for tilting at least one part of said platform structure for moving said mold assembly toward the lower end of the structure, stop means impacting with a lower part of the mold assembly while another and upper part is carried off the lower end of the platform structure by its momentum, and means for tilting said platform structureand said lower flask assembly part thereon in an opposite direction to discharge said lower part of the mold assembly from the other end of said platform structure, said lower part of the mold assembly traveling along the tilted part of said platform structure and its momentum providing the impetus for discharge of said lower part from the other end of said platform structure.

References Cited in the file of this patent UNITED STATES PATENTS