GB2074911A - Vertical face shake out for foundry molds - Google Patents

Abstract

The shake-out apparatus comprises a vibratory vertical wall (25) against which a mold and/or a large casting is pressed while supported by a crane. The wall (25) is suspended from a rigid support structure (10) by vertical isolators (24, 29) and horizontal isolators, e.g. air- springs (30, 31), for vibration in a vertical plane by exciters (35). <IMAGE>

Description

SPECIFICATION Vertical face shake out for foundry molds Technical Field of the Invention The invention has to do with foundry practices related to "shake out" devices and particularly related to shake out equipment for cleaning very large castings of up to a hundred tons or more in weight.

Background Art Heretofore, foundries have always had a definite need for "shake out" devices to separate a molded casting from the mold and to remove all of the sand from the inside of the mold. As herein used the term "flask" has reference to the outside container for the sand mold and it is this sand that must be removed by the shake out.

The flask basically comprises a four sided box and when preparing a mold the center core is inserted first, after which a pattern is placed in the mold and which actually comprises the form of the casting. Sand is packed around the pattern after which the pattern is carefully removed and the void which this leaves is filled by pouring hot metal into the mold and this is allowed to set to form the final casting. It is the cleaning of all of this equipment that this invention is concerned with. It has been the practice to remove the casting as well as the casting, the core and the sand by vibratory action and this action is obtained by use of the "shake out" devices referred to.

A typical method used for shaking out molds utilized a shake out table particularly where large casting were involved. In use of the shake out table the entire mold was placed upon the. table which vibrated up and down in a vertical direction and this vibration caused the flask and the foundry sand as well as the casting to separate with the sand falling through holes provided for that purpose in the shake out table. The flask and the casting were removed by a crane so that, in effect, all of the various pieces were deposited on the table where they would remain until they were lifted off.

Some foundries have utilized what is known as a "shake out feeder" wherein the mold was placed at the inlet of the feeder by means of a "push-out" which was nothing more than a large plunger that pushed the casting and the sand out of the flask and caused it to drop into the inlet of the feeder. The feeder conveyed the materials forward by a vibratory action so that the casting and the molding sand were subjected to this vibration. The sand dropped through holes in the deck of the feeder and the casting rode on top of this deck and eventually was discharged over the end of the feeder. The degree of cleaning obtained depended upon the length of time the parts were retained on the vibrating deck.

Summary of the Invention According to the invention there is provided a foundry shake out apparatus including a support structure, a substantially vertical front wall mounted on the support structure, isolators operable vertically and horizontally between the vertical wall and the support structure, and a vibrating device mounted on the wall to cause said wall to vibrate.

The invention thus includes a basic support structure for a vibratory vertical front wall that is suspended from the structure and isolated from the structure, including isolating springs at the bottom of the wall, air-mounts that comprise air springs above and below a pair of vibratory excitors mounted behind the vibratory wall which in addition to isolating the wall also act as shock absorbers when a heavy casting first "collides" with the vertical wall. The vibratory wall may comprise a thick steel plate secured to a heavy steel block of similar size with a thick slab of rubber sandwiched between the steel plate and the block with the complete sandwich secured together by bolts, or the like.This rubber sandwich acts to absorb some of the shock resulting from the pounding of a large and heavy casting against the vibratory wall and importantly, also reduces the sound level of the noise resulting from the vibrating action. In fact, when the vibratory wall is operating without a mold in engagement with the wall, the sound level may approximate 55 db and when in actual operation vibrating a casting, the sound level is not more than 85 db, which for a shake out of any capacity is very quiet and when considered in relation to the capacity of this equipment is exceptionally quiet.

The vibratory front wall of the shake out is disposed vertically and is especially adapted to the cleaning of large castings weighing upwardly of ten tons and including exceptionally large castings of up to one hundred tons, or more. Such excessively large casting were not adaptable to cleaning on the previously existing shake out tables or feeder shake outs of the prior art but the vertically disposed vibrating wall enabled such castings to be suspended by a crane in contact with the vertical wall to be vibrated in a manner effectively to provide complete cleaning and separation of the casting from the flask and core sand. The vertical vibrating wall not only revolutionizes the foundry shake out practices especially for large castings but does so with equipment that can be manufactured at substantially lower cost than the shake outs previously used.

Objects of the Invention The primary purpose of this invention is thus related to a new shake out apparatus as used in metal casting foundries and especially adapted to the effective cleaning of exceptionally large castings by suspending the castings in contact with a vertically disposed vibratory wall surface.

The principal object of the invention is to provide a vibratory wall suspended from a base supporting structure and isolated therefrom for vibrating independently thereof when a casting is placed in contact with the vibratory wall.

An important object of the invention is the provision of a vibratory wall disposed substantially vertically enabling a large casting to be suspended next to the vibratory wall to be shaken out and separated from the flask and core sand.

Another object of the invention is to provide a foundry shake out apparatus including a vertically disposed vibratory wall constructed from a thick steel face plate and a heavy steel block as a back-up with a thick rubber slab sandwiched between the two steel members.

A further object of the invention is the provision of a vertically disposed shake out for metal foundries wherein a vibratory vertical front wall is mounted on a basic supporting structure in isolated relationship for freely vibrating independently of the support structure.

Still another object of the invention is to provide a foundry shake out apparatus including a vibratory front wall mounted at the top thereof by means of suspension isolators from a basic support structure and having supporting springs between the bottom of the wall and the support structure and including a plurality of groups of horizontal isolators behind the front wall to isolate the wall from the support structure and absorb shocks resulting from large castings engaging the front face of the wall.

A still further object of the invention is the provision- of a vertical vibratory wall shake out having a pair of vibratory excitors mounted on the rear face of the wall on vertical axes and rotating in opposite directions to obtain a linear stroke action.

A foundry shake out apparatus embodying the invention is diagrammatically illustrated in the accompanying drawings, wherein: Figure 1 is a general side elevational view of the present shake out apparatus including a vertically disposed vibratory wall structure mounted on a basic support structure in isolated relationship; Figure 2 is a front elevational view of the shake out apparatus showing the front face of the vibratory wall with the top isolators suspending the wall structure from the support structure and bottom springs supporting and isolating the wall from the support structure at this location; and Figure 3 is a general plan view of the shake out apparatus showing the construction of the basic support structure and the vertically disposed vibratory wall at the front of the structure.

Description of Preferred Embodiment In the concept of this invention it was found that the excessively large molds for very large and heavy castings were not adaptable to foundry shake out operations utilizing the usual shake out table, or feeder, where the castings were so large and heavy, because of the extreme difficulty in engineering a vibrating unit to handle such massive weights. By suspending a large mold on a crane hook it was demonstrated that such large units could be pressed against the face of a vibrating vertical wall and held there to be vibrated clean of core sand and separate the casting from the flask.

Referring to Figure 1 of the drawings it will be seen that the basic supporting structure 10 is rigidly mounted on and secured to a substantial base foundation 11. A pair of diagonals 12 extend upwardly at an angle toward the front of the structure and project over a pair of uprights 1 3 forming the front structure of the basic support.

The uprights 13 and the diagonals 12 are connected by a series of bracing connecting members 14, 1 5 and 1 6 which reinforce the support structure in the several directions required and a cross-member 1 7 connects the diagonals 12 at the top where they extend outwardly over the uprights 13. A bracket assembly 1 8 is mounted on and rigidly secured to the support structure by means of the cross member 1 7 for a purpose hereinafter to appear. Both the diagonals 12 and the upright members 13 are mounted on and secured to horizontal base members 1 9 which in turn are secured to transverse base members 20 at the rear of the basic support structure.The members 1 9 extend forwardly of the uprights 1 3 as will best be seen in Figure 1.

The uprights 13 are connected by-plates 21 and 22 extending across the front of the uprights and secured thereto by welding, or the like. The plates 21 and 22 are located adjacent to the top and bottom respectively of the uprights and are each backed up and reinforced by series of spaced web plates 23 extending between the uprights and welded to the uprights and to the back sides of the plates 21 and 22 to provide a rigid bearing structure, or back-up against which vertically spaced sets of horizontal isolators are adapted to bear as hereinafter described.

The bracket assembly 18 at the top of the basic support structure 10 provides a mounting connection for a series of suspension isolators 24 that are connected to and suspend a front wall structure 25 from the basic support structure. The wall structure 25 hangs more or less free from the top of the support structure by means of the suspension isolators 24 and is constructed of a heavy steel face plate 26 and a heavy steel block 27 with a heavy slab of rubber 32 sandwiched there between. The sandwiched assembly is secured together preferably by bolts and vertically spaced guide blocks 28 at each side of the steel block 27 which blocks 28 are secured to the support structure upright members 13 by welding and engage the opposite sides of the block 27 to prevent lateral displacement of the wall assembly 25 and act to guide and confine the assembly to its normal operative position.

The front wall assembly is supported at the bottom by isolating springs 29 disposed between the base structure and the bottom edge of the wall assembly. The springs 29 are mounted on a member 39 extending between and secured to the base members 1 9 by welding. Two vertically spaced groups of horizontal isolator springs 30 and 31 are disposed behind the front wall assembly at upper and lower locations corresponding with the positions of the back-up plates 21 and 22 on the support structure so that these springs can act to isolate the front wall structure from the support structure during operation and whena heavy casting suspended from a crane, as indicated in Figure 1 , first collides with the steel plate 26, the shock resulting from this massive weight is absorbed largely by the springs 30 and 31 but the rubber slab 32 also absorbs some of the initial shock of this collision and deadens the sound as well. It should be pointed out that the bolted connection securing the rubber slab 32 between the steel block 27 and the steel plate 26 includes an angle member 33 at each side of the assembly and which is secured to the respective sides of the block 27 by welding so that an outstanding flange is provided behind the slab 32 at each side and it is through this flange that the bolts 34 extend after after passing through the steel plate 26 and the rubber slab 32.

The steel face plate 26 thus is replaceable should it become damaged or unduly worn due to the heavy service.

The isolator springs 30 and 31 actually are airmounts, as shown and in addition to their function as shock absorbers against the impacts of heavy castings, also act as isolators to the vibratory action of the front wall assembly 25 under the excitation of a pair of vibratory excitors 35 mounted on the back side of the steel block 27 between the isolator air mounts 30 and 31. The operating shafts of these excitors are disposed vertically and rotate in opposite directions to cause the wall assembly 25 to vibrate back and forth and it is this reciprocating vibratory action that pounds a flask bearing against the face plate 26 to cause the casting to fall clear and the clinging sand to come loose from the fiask.The excitors 35 are electrically operated and the usual eccentric weights disposed at the top and bottom of the excitors are enclosed by housings 37 as best shown in Figures 1 and 2.

The entire front wall assembly 25 is completely free to vibrate in this manner since the wall assembly is supported at the bottom on the row of steel coil isolator springs 29 which provide undersupport for the vibrating wall as well as isolating the wall from the basic supporting structure and the top suspension arm isolators 24 are primarily for safety purposes not only to help support the wall assembly but especially function to prevent the vibratory wall 25 from separating completely from the support structure 1 0. If these connections 24 were not utilized the vertical wall 25 might fall forward and constitute a serious hazard to foundry personnel.

As shown in Figure 2, a pair of retaining brackets 38 is mounted at respectively opposite sides of the vertical wall structure 25 for the attachment of a suitable cable should it be thought necessary by some users to bind a casting to the vibrating wall to maintain contact for effective shake out but it has been found that mere suspension of a massive casting and flask against the face 26 of the vibrating wall is fully capable of obtaining the degree of vibration of the casting and flask necessary to effect separation and shake out of the core sand.

The vertical face shake out of this invention involving the basic principle of a vibrating substantially vertical face to perform the shake out function by suspending the mold against such vibrating face by means of a crane represents a highly effective apparatus for separating such massive castings from the flasks and to clean out the core sand. In operation an entire mold is suspended by the crane and pressed against the vibrating vertical face 26. In a matter of seconds the bottom of the mold is caused to drop free together with the core and the casting as well. The flask is continued to be held against the vibrating vertical wall until all of the sand clinging to the inside surfaces is dislodged and drops free, after which the clean flask may be moved away.If necessary, the core and casting can be again pressed against the vibrating vertical wall to remove all traces of core sand which may remain after the initial separation.

In actual operation, as indicated in Figure 1, the entire mold is brought to the shake out by a crane and lowered to the foundry floor whereupon a foundry operator disconnects the C clamps normally used to lock the core bottom to the flask, but when these clamps are released the core and casting usually continues to adhere to the flask because of the strong bonding capability of the hot molding sand contained in the flask. The entire mold assembly is now pressed against the vibrating vertical wail 25 by the crane and the vibration of the unit causes the mold and core to drop free of the flask almost immediately. The flask is then 17fled sightly by the crane and pressed firmly against the vibrating wall to remove all of the stubbornly clinging molding sand from the internal side walls. The cleaned flask is removed by crane from the shake out but the hot casting and the core remain. To separate the internal core clinging to the casting, from the hot casting, the casting is pressed against the vibrating vertical wail and the core drops free after which the hot casting is removed from the shake out by the crane.

From the foregoing it will be seen that a foundry shake out apparatus has been provided that incorporates a substantially vertically disposed vibratory wall isolated from supporting structure and adapted to vibrate large casting molds held against the face of the vibrating wall.

Claims (8)

1. A foundry shake out apparatus including a support structure, a substantially vertical front wall mounted on the support structure, isolators operable vertically and horizontally between the vertical wall and the support structure, and a vjbrating device mounted on the wall to cause said wall to vibrate.

2. A foundry shake out apparatus as claimed in Claim 1 , wherein said wall comprises an assembly including a heavy metal face plate and heavy metal block secured together with a rubber slab between said face plate and metal block.

3. A foundry shake out apparatus as claimed in Claim 2, wherein said vibrating device is located on the back side of the substantially vertical wall between said isolators operable horizontally.

4. A foundry shake out apparatus as claimed in any preceding claim, wherein said isolators operable vertically include undersupporting isolator springs adjacent the bottom of said substantially vertical wall and suspension isolators adjacent the top of the vertical wall both operable between the vertical wall and the support structure.

5. A foundry shake out apparatus as claimed in any preceding claim, wherein said'vibrating device includes a pair of excitors having vertical axes and rotating in opposite directions to cause said substantially vertical wall to reciprocate back and forth.

6. A foundry shake out apparatus as claimed in Claim 2, wherein said face plate and metal block are secured by bolts passing through the face plate and rubber slab adjacent to respectively opposite side edges of the face plate, and flanged members secured to respectively opposite sides of said metal block, said bolts passing through an outstanding flange of each of said flanged members.

7. A foundry shake out apparatus as claimed in Claim 6, wherein one or more guide blocks are disposed at respectively opposite sides of said heavy metal block and secured to said support structure to guide and confine said front wall assembly to its operative position.

8. A foundry shake out apparatus, substantially as hereinbefore described with reference to and as shown in the accompanying drawings.