SAND CORE MAKING MACHINE

Abstract

A sand core making machine that includes a hopper having a hollow body with an inner surface delimiting a passageway for a material used in the manufacture of a sand core. The hopper includes a plurality of breaker assemblies with each breaker assembly having at least one string. The ends of a string are attached to corresponding attachment points of the inner surface of the hollow body, such that the strings are arranged in a flow passage of the material. At least two breaker assemblies are spaced apart such that the two breaker assemblies interact with each other to break lumps of the material supplied to the hopper when the hollow body is shaken.

Claims

1. A sand core making machine comprising; a hopper having a hollow main body with an inner surface delimiting a passageway for a material used in the manufacture of a sand core, the hopper including at least first and second breaker assemblies that respectively include first and second strings, each of the first and second strings having a first end and a second end opposite the first end, the first and second ends of the first string being respectively attached to first and second attachment points of the inner surface of the hollow main body, the first and second ends of the second string being respectively attached to third and fourth attachment points of the inner surface of the hollow main body, the first and second strings not being connected to one another in the material passageway and being configured to vibrate upon the hollow main body of the hopper being shaken, the first and second breaker assemblies being spaced apart from each other such that the when the first and second strings vibrate, the first and second breaker assemblies interact with each other to break lumps of the material supplied to the hopper; and an actuator coupled to and configured to shake the hollow main body of the hopper.

2. The sand core making machine according to claim 1, further comprising a first plurality of breaker elements attached to and distributed in series on the first string, and a second plurality of breaker elements attached to and distributed in series on the second string, the first and second plurality of breaker elements respectively protruding from the first and second strings.

3. The sand core making machine according to claim 2, wherein the first and second plurality of breaker elements has a shape selected from the group consisting of a spike shape, a cube shape and a ball shape.

4. The sand core making machine according to claim 1, wherein the first string extends in a first direction and resides at a first height inside the hollow main body of the hopper, and the second string extends in a second direction and resides at a second height inside the hollow main body of the hopper, the second direction being different than the first direction and the second height being different than the first height.

5. The sand core making machine according to claim 2, wherein the first string extends in a first direction and resides at a first height inside the hollow main body of the hopper, and the second string extends in a second direction and resides at a second height inside the hollow main body of the hopper, the second direction being different than the first direction and the second height being different than the first height.

6. The sand core making machine according to claim 5, wherein the first and second directions are perpendicular to one other.

7. The sand core making machine according to claim 1, wherein the first and second attachment points reside in a first plane, and the third and fourth attachment points reside in a second plane below the first plane.

8. The sand core making machine according to claim 2, wherein the first and second attachment points reside in a first plane, and the third and fourth attachment points reside in a second plane below the first plane.

9. The sand core making machine according to claim 7, wherein the first and second planes are parallel to one another.

10. The sand core making machine according to claim 1, wherein the first and second strings are configured to be arched upon being vibrated.

11. The sand core making machine according to claim 1, further comprising a filtering assembly arranged below the first and second breaker assemblies, the filtering assembly including at least one filter mesh.

12. The sand core making machine according to claim 11, wherein the filtering assembly comprises a first filter mesh and a second filter mesh spaced apart from and below the first filter mesh, and a plurality of elements arranged between the first and second filter meshes with freedom of movements.

13. The sand core making machine according to claim 12, wherein a distance between the first and second filter meshes is larger than a size of the plurality of elements so that upon the hollow main body being shaken, the plurality of elements jump between the first and second filter meshes.

14. The sand core making machine according to claim 12, wherein a space between the first and second filter meshes is divided into a plurality of compartments, each of the plurality of compartments housing a subset of the plurality of elements.

15. The sand core making machine according to claim 14, wherein adjacent compartments of the plurality of compartments are communicated with each other through passages that are smaller in size than the size of the plurality of elements to prevent a movement of the elements between the adjacent compartments but allowing the passage of material between the adjacent compartments.

16. The sand core making machine according to claim 15, wherein the filtering assembly comprises walls that extend at least partially between the first and second filtering meshes to delimit the plurality of compartments.

17. The sand core making machine according to claim 16, wherein the walls extend partially between the first and second filtering meshes with there being a gap between the walls and the second filtering mesh.

18. A sand core making machine comprising; a hopper having a hollow main body with an inner surface delimiting a passageway for a material used in the manufacture of a sand core, the hopper including a first breaker group having a first plurality of spaced-apart breaker assemblies arranged in a first plane inside the passageway, and a second breaker group having a second plurality of spaced-apart breaker assemblies arranged in a second plane inside the passageway, the second plane being spaced apart from the first plane, the first and second plurality of breaker assemblies being coupled to the hollow main body and configured to interact with one another upon the hollow main body being shaken; and an actuator coupled to and configured to shake the hollow main body of the hopper.

19. The sand core making machine according to claim 18, wherein the first and second planes are arranged parallel to one another.

20. The sand core making machine according to claim 18, wherein each of the first plurality of breaker assemblies includes a string extending in a first direction, and each of the second plurality of breaker assemblies includes a string extending in a second direction different from the first direction.

21. The sand core making machine according to claim 20, wherein the first and second directions are perpendicular to one another, and the strings of the first plurality of breaker assemblies being arranged parallel to one another, and the strings of the second plurality of breaker assemblies being arranged parallel to one another.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIG. 1A shows a perspective view of a hopper of an embodiment of a sand core making machine according to the invention.

[0013] FIG. 1B partially shows the hopper in FIG. 1A.

[0014] FIG. 2 shows the hopper of FIG. 1A, arranged in a sand core making machine.

[0015] FIG. 3A shows a detail A-A of the hopper of FIG. 1A, without the main body of the hopper being subjected to shaking.

[0016] FIG. 3B shows the detail of FIG. 3A, with the breaker assemblies in one position as a result of the shaking of the main body.

[0017] FIG. 4 shows a cutaway side view of the hopper of FIG. 1A.

[0018] FIG. 5 shows a filtering assembly of the hopper of FIG. 1A, without a first filter mesh.

DETAILED DISCLOSURE OF THE INVENTION

[0019] FIG. 1A shows a hopper 100 of an embodiment of a sand core making machine 1000 as shown by way of example in FIG. 2. The hopper 100 comprises a hollow main body 1 with an inner surface 1.0 delimiting a passage for a material used in the manufacture of the sand core. The machine 1000 comprises a mold not shown in the figures, adapted to receive the material from the hopper 100, such that the sand core is generated in the mold.

[0020] The material supplied to the hopper 100 falls in a supply direction through the hopper 100, which generally coincides with a longitudinal axis of the hopper 100. The material may comprise lumps, or even lumps may be generated during its supply, and the lumps may adversely affect the manufactured sand core if the lumps reach the mold. Therefore, the hopper 100 comprises a plurality of breaker assemblies 3 arranged, at least partially, inside the main body 1, such that when the material is supplied to the hopper 100, the breaker assemblies 3 can break the lumps and eliminate them or at least reduce their size. Preferably the hopper 100 comprises as many breaker assemblies 3 as are necessary so that all the material supplied to the hopper 100 passes through some breaker assembly 3, thus ensuring that no unwanted lumps reach the mold without first having been contacted by any breaker assembly 3. The plurality of breaker assemblies 3 may form a lattice as partially shown in FIG. 1B.

[0021] Each breaker assembly 3 comprises at least one string 3.0, and each end of a string 3.0 is attached to a corresponding attachment point 1.1 of the inner surface 1.0 of the main body 1 such that the string 3.0 is arranged in the passage delimited by the inner surface 1.0. Two attachment points 1.1 associated with the same string 3.0 are arranged in such a way that they can be joined together with a straight line passing through the passage delimited by the inner surface 1.0. Depending on the tension of the string 3.0 between the attachment points 1.1 the string 3.0 will be more or less slack, but preferably the string 3.0 will be sufficiently taut to form a line. The string 3.0 is preferably made by a rigid material such as plastic or metal, and, preferably, the material is stainless. A string 3.0 can be a wire, a cable or similar, but, in any case, it is configured to be arched or cambered when it vibrates (as shown in FIG. 3B).

[0022] In some embodiments, as in the embodiment shown in the figures for example, the hopper 100 is rectangular (although it could have other shapes, if required, such as a cylindrical shape for example). In these embodiments the attachment points 1.1 associated with the same string 3.0 are on different walls. In the case of the embodiment shown in the figures, the attachment points 1.1 associated with the same string 3.0 are on opposite walls.

[0023] The main body 1 is configured to be shaken during use, and when shaking of the main body 1 is generated, the strings 3.0 vibrate (as depicted in FIG. 3B, as compared to FIG. 3A where strings 3.0 are shown without the main body 1 being shaken) such that they are arched or cambered, and the breaker assemblies 3 are spaced apart such that, with said shaking, the breaker assemblies 3 interact with each other and break up any lumps that are present in the material supplied to the hopper 100. How they vibrate will depend on the frequency and amplitude at which the main body 1 is shaken, and the required frequency and/or amplitude will be applied in each case, depending on the design of the breaker assemblies 3 and the material supplied to the hopper 100 in each case, for example, and may even be varied throughout the same supply of material, to further refine the filtrate carried out in the hopper 100 for example.

[0024] Preferably, each breaker assembly 3 comprises a plurality of breaker elements 3.3 distributed in series, associated with the corresponding string 3.0, and attached to the string 3.0. Each breaking element 3.3 may have any desired shape, but protrudes from the string 3.0 to which it is attached. Thus, it may have a spike shape, a cube shape or a ball shape, for example. In the embodiment shown in the figures, the breaker elements 3.3 are balls. The material of the breaker elements 3.3 is, preferably, the same material of the string 3.0.

[0025] By protruding from the string 3.0 to which it is attached, the breaker elements 3.3 strike against the material delivered to the hopper 100, generating a more effective strike which ensures that any lumps are broken to a greater extent. As the breaker elements 3.3 are arranged in series, the positive effect of the breaker elements 3.3 covers the largest possible area of the passage for the material supplied to the hopper 100.

[0026] During vibration of a string 3.0, the amplitude of such vibration in the string 3.0 is smaller the closer it is to the end which is attached to an attachment point 1.1, and it has been detected that this may result in a greater risk of accumulation of material at the ends of the string 3.0, despite the vibrations generated. Thus, in order to avoid this possible negative effect, the hopper 100 comprises a string 3.0 of one breaker assembly 3 which intersects an end of another string 3.0 of another (contiguous) breaker assembly 3, at a different height, i.e. a string 3.0 of one breaker assembly 3 extends in a first direction at a different height from the end of another string 3.0 of another breaker assembly 3 which extends in a second direction different from the first direction (see FIG. 4). Preferably the first direction and the second direction are perpendicular to each other. The separation distance between the two breaker assemblies 3 is such that the breaker assemblies 3 interact with each other when the main body 1 is shaken, in order to break possible lumps of the material supplied to the hopper 100.

[0027] Additionally, or alternatively, in the case where a breaker assembly 3 has a plurality of the breaker elements 3.3, the size of the breaker elements 3 is larger the closer it is to an end of the corresponding string 3.0.

[0028] The strings 3.0 of the breaker assemblies 3 may be extended transversely (in a plane transverse to the material supply direction), or inclined with respect to that transverse plane, and may be arranged as required. This may depend, for example, on the ease of mounting the breaker assemblies 3 in the hopper 100 and/or the required specifications for the material. The more breaker assemblies 3 there are, the greater the lump-breaking capacity of the hopper 100 will generally be.

[0029] In some embodiments, the attachment points 1.1 associated with a plurality of breaker assemblies 3 are distributed in a same plane, said plane being preferably transverse to the material supply direction, the breaker assemblies 3 whose attachment points 1.1 are in a same plane forming a breaker group. In such cases, preferably, all the breaker assemblies 3 of a breaker group are parallel to each other and comprise an equal distance therebetween. The hopper 100 may comprise a single breaker group or a plurality of breaker groups, each breaker group being associated with a different plane and all planes being spaced apart from each other (preferably in the supply direction). This distance between planes is such as to allow the breaker assemblies 3 of one breaker group to interact with the breaker assemblies 3 of another breaker group when the main body 1 is shaken, in order to break possible lumps in the material supplied to the hopper 100. The more breaker groups one has, the greater the lump breaking capacity of the hopper 100 will generally be. Preferably, moreover, the breaker assemblies 3 of one breaker group extend in a different direction from the breaker assemblies 3 of the breaker group of an adjoining plane, as can be seen in the embodiment of the figures (see FIGS. 1B and 4), such directions being preferably perpendicular to each other.

[0030] When there is a plurality of breaker groups, furthermore, the distance between the breaker assemblies 3 of one breaker group may be different from the distance between the breaker assemblies 3 of another breaker group, the distance between the breaker assemblies 3 of another breaker group decreasing from top to bottom. Thus, the distance between the breaker assemblies 3 of a breaker group distributed in a first plane is greater than the distance between the breaker assemblies 3 of a breaker group distributed in a second breaker plane downstream of the first plane.

[0031] This is advantageous since as the lumps of material are broken up, the resulting lumps or particles become smaller and smaller, leaving less space between the breaker assemblies 3 of the next breaker assembly 3 for the material to pass through. It is the distance between breaker assemblies 3 that determines what size of lump or particle can pass between two adjacent or contiguous breaker assemblies 3.

[0032] The hopper 100 may further comprise a filtering assembly 4 arranged downstream of the breaker assemblies 3 (in the supply direction). The hopper 100 comprises an inlet opening 101 through which material is supplied and an outlet opening 102 through which material exits the hopper 100, the filtering assembly 4 being preferably arranged at the outlet opening 102 and in a way that all material exiting the hopper 100 has passed through the filtering assembly 4.

[0033] The filtering assembly 4 comprises at least one filtering mesh 4.1, such that only material comprising a size smaller than that defined by the size of the holes of the filtering mesh 4.1 can exit the hopper 100 and can be used for the manufacture of sand cores. In this way, the action of the breaker assemblies 3 and the filtering assembly 4 results in the utilization of all, or at least to a greater extent, of the material supplied to the hopper 100, and in a manner which ensures the manufacture of acceptable sand cores which are free from lumps of such material. For the sake of clarity such a filter mesh 4.1 is not shown in FIG. 1B.

[0034] Preferably, as in the embodiment shown in the figures, the filtering assembly 4 comprises a first filtering mesh 4.1 and a second filtering mesh 4.2 spaced apart in height (longitudinally, in the supply direction), and a plurality of elements 4.3 (preferably balls) arranged between both filtering meshes 4.1 and 4.2 with freedom of movement. The distance between both filter meshes 4.1 and 4.2 is larger than the size of these elements 4.3, so that when the main body 1 is shaken, these elements 4.3 move or jump between the two filter meshes 4.1 and 4.2, hitting the material between both filter meshes 4.1 and 4.2 and reducing the size of the lumps which may have reached therein after passing through the breaker assemblies 3. The first filter mesh 4.1 is arranged upstream of the second filter mesh 4.2 and comprises holes for the passage of material larger than the holes of the second filter mesh 4.2, so that some lumps that have passed through the first filter mesh 4.1 cannot pass through the second filter mesh 4.2 until they have been hit and broken by the elements 4.3.

[0035] Preferably, in addition, the space between the two filter meshes 4.1 and 4.2 of the filtering assembly 4 is divided into a plurality of compartments 4.4, as shown in FIGS. 4 and 5 by way of example, by walls 4.5 extending partially, preferably from the first filter mesh 4.1 towards the second filter mesh 4.2. In each compartment 4.4, the hopper 100 comprises a plurality of elements 4.3. Due to the shaking supported by the main body 1 of the hopper 100, it is possible for the elements 4.3 to concentrate in the same area over time in absence of sad compartments 4.4, and the fact of compartmentalising the space between the two filtering meshes 4.1 and 4.2 avoids this possibility and ensures the presence of elements 4.3 throughout this space, providing homogeneity in the filtering performed by the filtering assembly 4. The compartments 4.4 are distributed transversally to the material supply direction.

[0036] Preferably the walls 4.5 do not reach the second filter mesh 4.2, leaving a gap 4.6 between it and the filter mesh 4.2. This gap 4.6 is used to allow the supplied material to move through the entire filtering assembly 4 and not only through the interior of a compartment 4.4, but the gap 4.6 is such that it does not allow the passage of an element 4.3 between a compartment 4.4 and an adjacent compartment 4.4, so that the elements 4.3 which are in a compartment 4.4 always remain in the compartment 4.4.

[0037] In some embodiments, the hopper 100 comprises an actuator attached to the main body 1 and configured to shake the main body 1 in a controlled manner. The actuator is adapted to be able to apply a frequency of vibration to shake the main body 1, and to control the frequency, and to vary the frequency when required if so required. Furthermore, the actuator could also control the amplitude of the frequency, thus having total control over the shaking of the main body 1. Depending on the value of the frequency the vibration generated from the breaker bodies 3 will be greater or lesser, and depending on the amplitude the shock exerted by the breaker assemblies 3 will be greater or lesser.

[0038] The sand core making machine 1000 comprise an actuator 2 associated with the hopper 100 as shown in FIG. 2, for causing the shaking of the hopper 100, and the actuator 2 can be part of the hopper 100 or not. In any embodiment, a machine 1000 may further comprise a control unit 1001 such as a microprocessor or other computationally capable device, communicated with the actuator 2, to be able to cause the actuator 2 to actuate in a controlled manner.