ES2876233T3 - Feeding system - Google Patents

Abstract

A feed system (100, 200, 300) comprising: a base (10, 110, 210, 310, 410) comprising a first end (12, 112, 412) for mounting in a mold pattern, a second opposite end (14, 114, 414) and a hole (16, 416) between the first (12, 112, 412) and second (14, 114, 414) ends defined by a side wall (18, 118, 418) , the side wall (18, 118, 418) comprising a first connecting region (24, 124, 224, 324, 424) spaced from the first end (12, 112, 412); and a body (34, 134, 234, 334) that is spaced from the base (10, 110, 210, 310, 410), the body (34, 134, 234, 334) comprising a first end (36, 136) for mounting on the base (10, 110, 210, 310, 410), a second opposite end (38, 138) and a hole (40, 140) between the first (36, 136) and the second (38, 138 ) ends defined by a side wall (42, 142), the side wall (42, 142) comprising a second connecting region (48) spaced from the second end (38, 138), wherein one of the first (24, 124 , 224, 324, 424) and the second (48) connecting regions has a radially outer surface comprising at least one curved section (outer curved section) (30, 230, 330) whose radius increases continuously from a smaller radial distance (R1) at a larger radial distance (R2) from a fixed center point (P), where the other of the first (24, 124, 224, 324, 424) and second (48) connecting regions has a radially inner surface you buy It has at least one curved section (inner curved section) (60, 260, 360) whose radius increases continuously from a smaller radial distance (R3) to a larger radial distance (R4) from said fixed center point (P), in where the largest radial distance (R4) of the inner curved section (60, 260, 360) is greater than the largest radial distance (R2) of the outer curved section (30, 230, 330), and the largest radial distance small (R3) of the inner curved section (60, 260, 360) is greater than the smallest radial distance (R1) of the outer curved section (30, 230, 330), such that one of the first (24, 124 , 224, 324, 424) and the second (48) connection regions is sized to receive the other, wherein the largest radial distance (R2) of the outer curved section (30, 230, 330) is greater than the distance smaller radial (R3) of the inner curved section (60, 260, 360), such that when one of the first (24, 124, 224, 324, 424) and second (48) connecting regions is re conceived within each other, the base (10, 110, 210, 310, 410) and body (34, 134, 234, 334) can rotate relative to each other from an unlocked position to a locked position in the that a contact area (θ) between the first connection region (24, 124, 224, 324, 424) and the second connection region (48) extends over at least a part of the outer curved sections (30, 230 , 330) and inner (60, 260, 360), and wherein: (i) each of the outer (30, 230, 330) and inner (60, 260, 360) curved sections extends over at least 60° in a circumferential direction, optionally wherein the first (24, 124, 224, 324, 424) and second (48) connecting regions each comprise at least 2 outer (30, 230, 330) and inner ( 60, 260, 360), respectively; or (ii) the first (24, 124, 224, 324, 424) and second (48) connecting regions each comprise at least 2 outer (30, 230, 330) and inner (60, 260, 360) curved sections ), respectively, wherein the outer curved sections (30, 230, 330) extend in total over at least 200° in a circumferential direction, and the inner curved sections (60, 260, 360) extend in total over at least 200° in a circumferential direction; or (iii) the contact area (θ) extends over at least 90° in a circumferential direction.

Description

DESCRIPTION

Feeding system

The present invention relates to a feeding system for use in metal casting operations using casting molds. More particularly, the invention relates to a two-part feeding system comprising a body and a base.

In a typical casting process, molten metal is poured into a preformed mold cavity that defines the shape of the casting. However, as the metal solidifies it shrinks, resulting in shrinkage cavities which in turn result in unacceptable imperfections in the final casting. This is a well-known problem in the casting industry, and it is solved by the use of feed sleeves or risers that are integrated into the mold, during the formation of the mold. Each feed sleeve provides an additional (generally closed) volume or cavity that is in communication with the mold cavity so that molten metal also enters the feed sleeve. During solidification, molten metal within the feed sleeve flows back into the mold cavity to compensate for the shrinkage of the casting. It is important that the metal in the feed sleeve cavity remains molten longer than the metal in the mold cavity, which is why the feed sleeves are manufactured to be highly insulating or more usually exothermic, so that upon entering Contact with molten metal will generate additional heat to delay solidification.

After solidification and removal of the material from the mold, unwanted residual metal within the feed sleeve cavity remains adhered to the casting and must be removed. To facilitate removal of residual metal, the feed sleeve cavity can taper toward its base (i.e., the end of the feed sleeve that will be closest to the mold cavity) in a design commonly referred to as a neck-down sleeve. When a strong blow is applied to the residual metal, it separates at the weakest point that will be near the mold (the process commonly known as "shaking"). Small occupancy in the casting is also desirable to allow placement of feed sleeves in areas of the casting where access may be restricted by adjacent features.

Feed sleeves can be applied directly to the surface of the mold cavity, or they can be used in conjunction with a rupture core. A rupture core is typically a disc of refractory material (typically a core of resin bonded sand or a ceramic core or core of feed sleeve material) with a hole in its center that lies between the mold cavity and the feed hose. The diameter of the hole through the rupture core is designed to be smaller than the diameter of the inner cavity of the feed sleeve (which does not necessarily have to be tapered) so that a shake will occur in the rupture nucleus near the casting piece.

Molding sand can be classified into two main categories; chemically bound (based on organic or inorganic binders) or clay bound. Chemically bonded molding sand binders are typically self-hardening systems where a binder and chemical hardener are mixed with the sand and the binder and hardener begin to react immediately, but slowly enough to allow the sand to settle around pattern plate and then allowed to harden enough to be removed and cast. Clay-bonded molding systems use clay and water as a binder and can be used in the "green" or undried state and are commonly referred to as green sand. Green sand mixtures do not flow immediately or move easily by compressive forces only and therefore in order to compact the green sand around the pattern and give the mold sufficient strength properties, various combinations of shaking, vibration, is applied pressing and tamping to produce molds of uniform strength with high productivity.

Molding practices are well known and are described as examples in Chapters 12 and 13 of the Foseco Ferrous Foundryman's Handbook (ISBN 075064284 X). A typical process known as a no-bake or cold-set process is to mix the sand with a liquid resin or silicate binder together with an appropriate catalyst, usually in a continuous mixer. The mixed sand is then compacted around the pattern by a combination of vibration and tamping and then allowed to settle, during which time the catalyst begins to react with the binder resulting in hardening of the sand mixture. When the mold has reached manageable strength, it is removed from the pattern and continues to harden until the chemical reaction is complete.

EP-A-1184104 describes a two-part feed sleeve. During the molding operation, pressure is applied to the top of the sleeve and one element of the sleeve is folded towards the other. One of the sleeve parts is always in contact with the pattern plate, and the outer upper sleeve member moves towards the pattern plate and compresses the molding sand below it and adjacent to the pattern plate. One of the advantages of this folding sleeve is the small contact area with the pattern plate. Therefore, such collapsible sleeves have become popular for manual molding applications. However, a drawback of such sleeves is that, prior to use, the collapsible sleeve has a neck of Long feed that can cause problems in manual casting applications. Therefore, Foundry workers have to pre-compress the sleeve, but there is a risk of inhomogeneous pre-compression, which can result in inconsistent sleeve volumes and feed properties.

US 5158217 describes a twist lock joint between refractory tubular shapes used in bottom pouring of steel. The joint is formed by inserting a male polygonal protrusion of a first component into a complementary polygonal female recess of a second component. Upon rotation of either the female or male joint, the corners of the male polygonal boss are placed against the flats of the female polygonal boss to make a multi-point contact that locks the two components together.

An object of the present invention is to provide an improved feeder that can be used in a cast molding operation that alleviates one or more of the problems associated with known feeders.

According to a first aspect of the present invention, there is provided a feeding system according to claim 1.

Thus, it will be understood that the base and the body are separate components, which can be assembled to form a feed sleeve. The feed sleeve is assembled by inserting the second end of the base into the first end of the body, until one of the first and second connecting regions is received within the other in the unlocked position.

In the unlocked position, there is no contact between the outer and inner curved sections. In this position, the largest radial distance of the outer curved section can be radially aligned with the largest radial distance of the inner curved section, and the smallest radial distance of the outer curved section can be radially aligned with the smallest radial distance of the inner curved section.

As the base or body is rotated relative to the other, the larger radial distance of the outer curved section is shifted towards the smaller radial distance of the inner curved section, until the outer and inner curved sections become in area contact, thereby providing a friction lock.

Thus, unlike the multi-point contact formed in the polygonal locking system of US 5 158217, the present invention provides a contact area between the outer and inner curved sections of the connecting regions. This design allows for greater friction between the first and second connecting regions, such that the base and body of the sleeve lock together more securely.

Furthermore, by providing a larger contact area between the connecting regions, the risk of excessive twisting is avoided or at least significantly reduced. In the arrangement of US 5158217, if the male polygonal protrusion is too large, there is a risk of breakage or abrasion of the corners of the polygon in case of excessive twisting. If the protrusion is too small, there is a risk of excessive twisting of the two components, that is, rotation beyond the locking point such that the joint is unlocked. In the present invention, the provision of a contact area, which extends in a circumferential direction over at least a part of the outer and inner curved sections, prevents the lock from loosening by excessive twisting, as the greater the twisting (that is, the more relative rotation of the base and the body), the greater the blockage.

A further advantage of the invention is that, by virtue of the friction lock, no additional fixing means, such as gluing, are required to secure the base and the sleeve body to each other.

In some embodiments, the outer and inner curved sections are complementary in shape. By "complementary", it is meant that the shape of the curved sections is substantially the same (ie, the shape of one of the curved sections matches that of the other), but that one of the curved sections must be dimensionally larger. than the other so that the larger of the curved sections can receive the smaller of the curved sections inside it. Therefore, in the unlocked position and when the curved sections are fully aligned (that is, when the largest radial distance of the outer curved section is radially aligned with the largest radial distance of the inner curved section and the smallest radial distance of the outer curved section is radially aligned with the smallest radial distance of the inner curved section), a gap is formed between the outer curved section and the inner curved section, the width of the gap being unchanged over the extent of the sections in a circumferential direction.

In some embodiments, the first and second connecting regions are complementary. In these embodiments, the shape of the radially inner surface matches that of the radially outer surface around the entire circumference of the connecting regions.

In some embodiments, relative rotation of the base and body through an angle of 20 ° to 110 °, 30 ° to 90 °, or 40 ° to 70 ° is required to move the feeding system from the unlocked position to the locked position. It will be appreciated that the greater the number of curved sections in the connecting regions, the smaller the angle of relative rotation that is required to achieve locking.

In some embodiments, one of the first and second connecting regions comprises at least 2, at least 3, or at least 4 outer curved sections, and the other of the first and second connecting regions comprises at least 2, at least 3 or at least 4 interior curved sections. Preferably, the curved sections are equally spaced at the connecting regions. It will be appreciated that the larger the contact area between the first and second connecting regions, the more friction is provided between the outer and inner curved sections, and the stronger the connection or lock between the base and the body. It will be understood that the number of inner curved sections in one of the connecting regions is normally the same as the number of outer curved sections in the other connecting region. For example, the first connecting region may comprise 3 outer curved sections, and the second connecting region may comprise 3 inner curved sections.

In some embodiments, each of the outer and inner curved sections extends over at least 60 °, at least 75 °, at least 90 °, at least 120 °, at least 140 °, at least 160 °, or at least 180 °. in a circumferential direction. However, in some embodiments, each of the inner and outer curved sections extends over the same angle in the circumferential direction.

In some embodiments, the inner and / or outer curved sections extend substantially the entire circumference of the first / second connecting regions. In other words, where one curved section ends, the next begins immediately.

Alternatively, the inner and / or outer curved sections may be spaced apart, such that there are gaps between the adjacent curved sections. In these embodiments, the curved sections extend only over a portion of the circumference of the first / second connecting regions.

In some embodiments, the outer curved sections extend, in total, over at least 180 °, at least 200 °, at least 220 °, at least 250 °, at least 270 °, at least 300 °, at least 330 ° or at least 350 ° in a circumferential direction. In some embodiments, the interior curved sections total over at least 180 °, at least 200 °, at least 220 °, at least 250 °, at least 270 °, at least 300 °, at least 330 °, or at least 350 ° in a circumferential direction. The outer curved sections can be extended in total over the same angle as the total inner curved sections. For example, each of the first and second connecting regions may comprise 3 outer / inner curved sections, in which each curved section extends more than 100 ° such that the total outer / inner curved sections extend more than 300 ° in the circumferential direction.

In some embodiments, the first and second connecting regions each comprise no more than 6, no more than 5, no more than 4, or no more than 3 curved sections.

In some embodiments, in the locked position, the contact area between the first connection region and the second connection region extends over at least 90 °, at least 120 °, at least 150 °, at least 180 °, or at least 210 °. It will be appreciated that the extent of the contact area will depend in part on how locked the base and the body are to each other, and how "soft" the material that makes up these components is. It will also be appreciated that "the contact area between the first connecting region and the second connecting region" refers to the total area of contact between the outer and inner curved sections. For example, in an embodiment where the first and second connecting regions each comprise 3 curved sections, in the locked position 3 contact areas will be formed between the outer and inner curved sections. If each contact area extends over approximately 45 °, the (total) area of contact between the first and second connecting regions will extend over approximately 135 ° in a circumferential direction.

In some embodiments, the fixed center point coincides with the axis of the hole in the base and, optionally, with the axis of the hole in the body. It will be understood that by "coincident", the fixed center point may exactly coincide with, or may be at least within a few millimeters of the axis of the base hole and, optionally, of the axis of the body hole.

In some embodiments, the first connecting region has a radially outer surface comprising the at least one outer curved section and the second connecting region has a radially inner surface comprising the at least one inner curved section, such that the first region of Base connection is received within the second connection region of the body. This arrangement helps to ensure that the liquid metal correctly feeds the casting through the base portion.

In some embodiments, the cross-sectional area of the base decreases distally from the second end. In other words, the second end is wider than the first end, such that the side wall of the base is generally tapered. It is desirable for the first end to be narrower than the second end as it provides a small footprint in the mold pattern, allowing for easier and cleaner shaking after casting. The base can have any suitable cross-sectional shape. In some embodiments, the base is circular or oval in cross section. In some embodiments, the base is substantially frusto-conical.

An outer surface of the side wall of the base may be inclined with respect to the axis of the central hole. The Angle of inclination may vary along the longitudinal axis of the base (ie, from the first to the second end), or it may be substantially constant. In some embodiments, the side wall may comprise two or more side wall regions that differ in their inclination. For example, the base may comprise a lower region near the first end and an upper region distal to the first end, wherein the slope of the outer surface of the side wall is greater in the lower region than in the upper region. Thus, in these embodiments, the taper of the side wall is greater in the lower region than in the upper region.

It will be understood that the angle of inclination of the outer surface of the side wall of the base will vary according to the application and the anticipated requirements. If the angle is too small, it will result in a long base that can adversely affect the overall power performance of the power system. If the angle is too large, it will be more difficult for the mixed sand to flow and compact under and around the base in the trim.

In some embodiments, an inner surface of the side wall of the base is substantially parallel to the outer surface of the side wall. Alternatively, in some embodiments, the slope of the inner side wall surface is different from that of the outer side wall surface.

In some embodiments, the inner surface of the side wall of the base defines a substantially frusto-conical bore. In some embodiments, the inner surface of the side wall of the base flares at the first end, thereby defining a restriction in a lower portion of the bore, adjacent to the first end. This creates a notch or notch in the solidified feeder near the casting surface, further enhancing shaking.

The base can provide the function of a breaking core. Thus, in some embodiments, the base constitutes a rupture core or comprises an integral rupture nucleus.

It will be appreciated that the first and second ends of the base are open to allow molten metal to flow between the body and the metal casting. The first end of the base comprises a first opening, while the second end comprises a second opening. The first and second openings can be of any suitable shape and can be the same or different. In some embodiments, the first and / or second aperture is circular, oval, or oblong in shape (ie, it has two parallel straight sides and two partially circular ends).

The body provides a bore or cavity to receive molten metal, the cavity being closed by the side wall. The body is open at the first end, so that molten metal can flow between the metal melt and the body, through the base. In some embodiments, the second end of the body is closed. The body can be formed with an integral end wall, or the feeding system can include a separate cap to close the second end of the body.

Thus, in some embodiments, the feed system further comprises a lid or cover to prevent the molding sand from falling into the feeder and the casting cavity during molding. The cap can be formed either of the same material as the body or of a different material.

In embodiments where the second end of the body is closed, the end wall or cap may be flat-butted, domed, flat-domed, or any suitable shape.

The body can have any suitable cross-sectional shape. In some embodiments, the body is circular or oval in cross section. The side wall of the body can be substantially tubular or cylindrical. The cross section of an outer surface of the body may vary along the longitudinal axis of the body or, alternatively, the body may have a substantially constant outer surface cross section.

During use, the feed system can be placed on a support or molding pin that is fixed to the pattern plate, to hold the feed system in the required position prior to molding. In some embodiments, the body is provided with a central bore to receive one end of the casting pin, the central bore extending partially through the end cap or wall (i.e., a blind bore) or completely through the end cap. end cap or wall to top surface of end cap. The center hole or the blind hole can have a conical or frusto-conical shape. In certain applications, the feed system is suspended away from the pattern plate on a fixed pin. During mold formation, and under the application of pressure, the sleeve moves downward and the casting pin passes through the center hole (piercing the top surface of the wall or end cap in the case of a blind hole ), and ensures that the feed sleeve moves towards the mold plate in a uniform direction without deviating from the longitudinal axis. This ensures that the base remains fully in contact with the mold plate and that the sand is evenly compacted under the body. In other applications, a feed system can be used with a blind hole in a spring pin that compresses as the sleeve moves downward under molding pressure. Alternatively, the feed system can sit directly on the pattern plate and molding sand can be applied around it.

In some embodiments, the body comprises a Williams wedge, that is, a prism-shaped protrusion that extends to the top of the bore or body cavity. The Williams wedge may be an insert or it may be an integral part of the body that may be located on an interior of the end wall or cap of the sleeve. In some embodiments, the body comprises two or more Williams wedges. A Williams wedge prevents the premature formation of a casting skin in the upper region of the hole or cavity. In casting, when the feed system is filled with molten metal, an edge of the Williams wedge ensures atmospheric piercing of the molten metal surface and release of the vacuum effect within the feed system to allow a more consistent feed .

The feeding system of the invention is modular, allowing the base and body to be independently selected for the assembly of the feeding sleeve, thus providing flexibility in terms of the configuration of the feeding system, the materials used and maintaining stocks. Users can assemble the feed sleeve on site from base and body stock as required. This provides the added benefit of reducing packaging and transportation costs.

The base and body of the present invention may be formed or may comprise any refractory insulating and / or exothermic material or composition from which known feeders can be formed; the person skilled in the art will be able to select the appropriate materials for each particular requirement. The nature of the material is not particularly limited and it can be, for example, insulating, exothermic or a combination of both. Typically, an insulating feeder is made from a mixture of high- and low-density refractory fillers (e.g., silica sand, olivine, hollow aluminosilicate microspheres and fibers, chamotte, alumina, pumice, perlite, vermiculite) and binders . An exothermic feeder further requires a fuel (generally aluminum or aluminum alloy), manganese dioxide or potassium nitrate) and generally initiators / sensitizers (usually cryolite). Suitable feeder compositions include, for example, those sold by Foseco under the tradename KALMIN, FEEDEX and KALMINEX, prepared by both grouting and shot blasting methods.

In some embodiments, the base and the body are formed from the same material. Alternatively, the base and the body can be formed from different materials. This allows the base and the body to have different properties as needed.

In some embodiments, the base and / or body are made from insulating, insulating-exothermic, or exothermic material. In some embodiments, the base and / or body are manufactured from a high-density, highly exothermic material sold by Foseco under the trade name FEEDEX HD. In some embodiments, the base and / or body are manufactured from medium density exothermic insulating material sold by Foseco under the trade names KALMINEX XP and KALMINEX 2000. In some embodiments, the base and / or body are manufactured from of low-density insulating material sold by Foseco under the trade name KALMIN 600.

Additionally, the body and base of the feeder system can be formed by any of the known feeder-forming methods. For example, the body and / or base can be vacuum formed by slurrying the material around a forming set and within an outer mold, followed by heating the sleeve to remove the water and harden or cure the material. Alternatively, the body and / or base can be formed by tamping or blowing the material into a core box (shot blasting method) and curing the body and / or base by passing a reactive gas or catalyst through the sleeve to cure. the binder, or by applying heat through the use of a heated core box, or by removing the body and / or base and heating in an oven. The preferred method of manufacture is shot blasting, as it typically provides sleeves with greater dimensional accuracy and strength.

The strength of the base and body must be sufficient such that when they are twisted together to block the feed system, there is little or no abrasion that causes particle breakdown. Similarly, the material that forms the body and the base must be sufficiently rigid and not easily deformed, to prevent the locked assembled power system from being weak or loose. In some embodiments, the base and body strength is at least 5 kN, preferably at least 10 kN, and most preferably at least 15 kN. For ease of comparison, the strength of a component is defined as the compressive strength of a 50x50mm cylindrical trial body made from the same material. A 201/70 EM compression testing machine (Form & Test Seidner, Germany) is used and operated according to the manufacturer's instructions. The test body is placed in the center of the bottom of the steel plates and loaded to destruction as the lower plate moves towards the upper plate at a speed of 20 mm / minute. The effective strength of the actual body and foundation will depend not only on the exact composition, binder used, and manufacturing method, but also on the size and design of each component.

Therefore, the invention allows specific feeding systems with specific feeding performances to be easily and simply assembled to suit the requirements of individual castings. For example, the base component can be dimensionally and / or compositionally changed to accommodate the different requirements of different alloys in the casting. The body can also be dimensionally and / or compositionally changed, depending on the size of the casting and whether the feed requirements are driven by volume or modulus. By having a series of base and body units Individual users effectively have a kit that allows them to assemble power systems on demand to meet their changing requirements.

According to a second aspect of the present invention, there is provided an assembled feed sleeve from the feed system of the first aspect of the invention, in which the body is mounted on the base, and in which one of the first and the second connection regions is received within the other of the first and second connection regions.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which:

Figures 1a and 1b show perspective views, Figure 1c shows a top view and Figure 1d shows a bottom view of a base of a feeding system according to an embodiment of the present invention; Figures 2a and 2b show perspective views, and Figure 2c shows a bottom view of a body suitable for connecting to the base of Figure 1, according to an embodiment of the present invention;

Figure 3 shows a cross-sectional view of a feeding system according to an embodiment of the present invention, formed from the base of Figure 1 and the body of Figure 2;

Figure 4 shows a cross section of the feeder system of Figure 3, taken through line A-A, when the feeder system is in an unlocked position;

Figure 5 shows a cross section of the feeding system of Figure 3, taken through the line A-A, after relative rotation of the body by 35 ° to place the feeding system in a locked position;

Figures 6a and 6b show two cross-sectional side views in perpendicular planes of a feeding system according to an alternative embodiment of the present invention;

Figure 7 shows a cross-sectional view of a feeding system according to an embodiment of the present invention, when the feeding system is in an unlocked position;

Figure 8 shows a cross-sectional view of a feeding system according to a further embodiment of the present invention, when the feeding system is in an unlocked position;

Figure 9 shows the feeding system of Figure 8, after relative rotation of the body by 50 ° to place the feeding system in a locked position; and

Figure 10 shows a perspective view of a base of a feeding system according to an embodiment of the present invention.

With reference to Figures 1a-1d, a base 10 comprises a first open end 12, an opposite open second end 14, and a hole 16 between the first end 12 and the second end 14. The hole 16 is defined by a side wall 18 having an outer surface 20 and an inner surface 22. Side wall 18 comprises a first connecting region 24 adjacent to second end 14. Side wall 18 can be considered to comprise two additional regions, a lower region 26 extending from the first end 14, and an upper region 28 between the lower region 26 and the connection region 24. The first connection region 24 is slightly larger in cross-section than the upper region 28 of the side wall 18, such that it is formed a lip 32 between them.

The first end 12 of the base 10 is defined by a first annular mounting surface 25, which defines a circular opening 27 through which molten metal flows into the casting. The annular mounting surface 25 contacts the mold pattern when the feed system is in use. The second end 14 of the base 10 is defined by a second annular mounting surface 29 for receiving a body thereon.

Base 10 has an outer profile that is generally tapered from the second widest end 14 to the first narrow end 12. In the lower region 26, the outer surface 20 of the side wall 18 is tapered (25 ° to the axis of the hole) to a greater extent than in the upper region 28 (10 ° to the axis of the hole). In the embodiment shown, the base 10 is circular in cross section.

In the embodiment shown, the inner surface 22 of the side wall 18 is generally parallel to the outer surface 20, thereby defining a frusto-conical bore 16, but widens at the first end 12 of the base 10 to define a restriction. 17 at the bottom of the hole 16. After casting, this results in a notch that forms in the residual metal in the feeder and facilitates shaking.

Referring to Figures 2a-2c, a body 34 comprises a first open end 36, a second closed end 38 formed by an integral end wall, and a bore or cavity 40 extending between the first and second ends 36, 38, defined by a side wall 42. The side wall 42 has an inner surface 44 and an outer surface 46. The outer surface 46 can be considered to comprise a lower region 47, a middle region 50 and an upper region 52, each of the which have a different angle between the outer surface 46 and a central axis of the bore or cavity 40. The middle region 50 has an approximately tubular profile, while the upper and lower regions 47, 52 are tapered or frustoconical. The second closed end 38 of the body 34 is continuous with the upper region 52. The first end 36 of the body 34 is defined by an annular surface 53.

Figure 3 shows a feed system 54 formed from the body of Figure 2 mounted to the base of the Figure 1. It can be seen that the inner surface 44 of the side wall 42 of the body 34 does not follow the same profile as the outer surface 46. Instead, the bore or cavity 40 within the body is generally tapered, tapering in the direction of the second end 38 such that the thickness of the side wall 42 increases from the first end 36 to the second end 38. In the embodiment shown, a blind hole 55 for receiving a casting pin extends partially through the closed second end 38 of the body. 3. 4.

The inner surface 44 of the side wall 42 is formed with a second connection region 48 adjacent the first end 36. In the second connection region 48, the inner surface 44 is parallel to the axis of the bore. The bore 40 also widens in the region of the second connecting region, thereby forming an annular bearing surface 57 which rests on the second annular mounting surface 29 of the base 10.

Figure 4 shows the relationship between the first and second connection regions 24, 46, when the base 10 and the body 34 of the feeding system 54 are in the unlocked position. In the first connection region 24, the outer surface 20 of the side wall 18 comprises three outer curved sections 30, each of which extends over an angle of approximately 115 ° in a circumferential direction. The radius of each curve continuously increases from a smaller radial distance R ¹ to a larger radial distance R ² , measured from a fixed central point P that coincides with a central longitudinal axis of hole 16. Similarly, in the second region connecting link 46 inner surface 44 comprises three inner curved sections 60, each extending over an angle of approximately 115 ° in a circumferential direction. The radius of each curve increases from a smaller radial distance R ³ to a larger radial distance R ⁴ , measured from the fixed center point P. In the embodiment shown, the outer and inner side wall surfaces 18, 20 are of complementary shape in the connection regions 24, 46, the second connection region 46 being dimensionally slightly larger than the first connection region 24 such that the first connection region 24 fits within the second connection region 46 with only a narrow gap between them.

At the boundary between the smallest radial distance R ¹ of an outer curved section 30 and the largest radial distance R ² , a ridge 31 is formed. Similarly, at the boundary between the smallest radial distance R ³ of a section inner curve 60 and the larger radial distance R ⁴ , an opposite ridge 61 is formed. The ridges 31, 61 function as stops so that relative rotation between the body 34 and the base 10 is only possible in one direction, towards the locked position. In the embodiment shown in Figure 4, the body 34 must be rotated clockwise with respect to the base 10 to provide locking of the feeding system.

5 shows the first and second connecting regions 24, 46 upon rotation of the body 34 relative to the base 10 at an angle 35 ° to a locked position. It can be seen that as the body and base rotate relative to each other, the larger radial distance of each outer curved section is shifted towards the smaller radial distance of each inner curved section. In other words, a continuously increasing width side wall region moves into a continuously decreasing width space. This causes the outer curved sections to be positioned against the inner curved sections, thereby locking the first and second connecting regions, and thus the base and the body, to each other. In the embodiment shown in Figure 5, three contact areas are formed between the outer and inner curved sections, each area 9 extending over approximately 45 ° in a circumferential direction. Thus, the total area of contact between the first connection region 24 and the second connection region 26 extends over approximately 135 ° in a circumferential direction. The base and body cannot be unlocked by excessive twisting because the radius of each outer curved section continues to increase "behind" the contact area, such that it is not possible to force the outer curved sections out of the locked position.

Figures 6a and 6b show an alternative embodiment of a feeding system 100 according to the present invention, two cross-sectional views being in two different planes perpendicular to each other. The feeding system 100 comprises a base 110 and a body 134 mounted thereon. Base 110 comprises a first end 112, a second end 114, and a side wall 118 therebetween having an outer surface 120 and an inner surface 122. A first connection region 124 is provided adjacent the second end 114. Base 110 it is similar in shape to that of figure 1, in that it is substantially frustoconical. However, unlike the embodiment of Figure 1, the outer surface 120 of the side wall 118 is slightly curved, changing the angle of curvature from the first end 112 to the first connection region 124.

Body 134 comprises a first end 136, a second end 138, and a side wall 142 therebetween, defining a cavity 140. Side wall 142 has an inner surface 144 and an outer surface 146. Side wall 142 is substantially tubular , which has a slight taper towards the second end 138. In this embodiment, the second end 138 is closed by an end wall 170 in which two Williams wedges 172a and 172b project into the cavity 140 are formed. forms a blind hole 150 to receive a casting pin in end wall 170, between the two wedges 172a, 172b.

The first and second connecting regions of this embodiment may have the same dimensions and shape as the embodiment shown in Figure 3.

Figure 7 is a cross-sectional view of a feed system 200 according to a further embodiment of the present invention, and shows the feeding system 200 in an unlocked position. The feeding system 200 comprises a base 210 and a body 234, and may have the same general dimensions and / or shape as the feeding system 54 shown in Figures 1-4. In the embodiment of Figure 7, base 210 has a first connection region 224 having two outer curved sections 230, each extending over an angle of approximately 175 °, with associated ridges 231 formed at the boundary between the smallest radial distance and the largest radial distance. Similarly, body 234 has a second connecting region 246 having two inner curved sections 260, each extending over an angle of approximately 175 °, with associated ridges 261 formed at the boundary between the radial distance plus smallest and largest radial distance.

Figure 8 is a cross-sectional view of a feeder system 300 according to another embodiment of the present invention, and shows the feeder system 300 in an unlocked position. The feeding system 300 comprises a base 310 and a body 334, and may have the same general dimensions and / or shape as the feeding system 54 shown in Figures 1-4. In the embodiment of Figure 8, base 310 has a first connecting region 324 having three outer curved sections 330, each extending over an angle of approximately 115 °. In this embodiment, there is a notch or cutout 332 formed at the boundary between the smallest radial distance R1 and the largest radial distance R2. Similarly, body 334 has a second connecting region 346 having three interior curved sections 360, each extending over an angle of approximately 115 °, with notches or cutouts 362 formed at the boundary between the radial distance. smallest R3 and largest radial distance R4. The notches are used to align base 310 and body 334 when assembling power system 300. Figure 9 shows the first and second connection regions 324, 346 after rotation of body 334 relative to base 310 at an angle of 45 ° to a locked position. Three contact areas are formed between the outer and inner curved sections, each area 0 extending over approximately 40 ° in a circumferential direction, such that the total area of contact between the first and second connecting regions 324, 346 extends approximately 120 °. in a circumferential direction.

Figure 10 shows an alternative embodiment of a base 410, the base 410 comprising a first open end 412, an opposite open second end 414, and a bore 416 between the first end 412 and the second end 414. The bore 416 is defined by a side wall 418 having an outer surface 420 and an inner surface 422.

The first end 412 of the base 410 is defined by a first oblong mounting surface 425, which defines an oblong opening 427. The second end 414 of the base 410 is defined by a second annular mounting surface 429 for receiving a body thereon.

Base 410 has a first connection region 424 that has three outer curved sections, each extending over an angle of approximately 115 °, and ridges 431 formed at the boundary between the smallest and largest radial distance of the curved sections.

Base 410 has an outer profile that is generally tapered from the second widest end 414 to the first narrow end 412. The outer surface 420 of the side wall 418 tapers outward from the axis of the bore from the first end 412 to the second end 414, such that the base 410 has an oblong cross section at the first end 412 and a circular cross section at the second extreme 414.

Claims (10)

1. A feeding system (100, 200, 300) comprising: a base (10, 110, 210, 310, 410) comprising a first end (12, 112, 412) for mounting in a mold pattern, a second opposite end (14, 114, 414) and a bore (16 , 416) between the first (12, 112, 412) and the second (14, 114, 414) ends defined by a side wall (18, 118, 418), the side wall (18, 118, 418) comprising a first connecting region (24, 124, 224, 324, 424) spaced from the first end (12, 112, 412); and a body (34, 134, 234, 334) that is spaced from the base (10, 110, 210, 310, 410), the body (34, 134, 234, 334) comprising a first end (36, 136) for the mounting on the base (10, 110, 210, 310, 410), a second opposite end (38, 138) and a hole (40, 140) between the first (36, 136) and the second (38, 138) ends defined by a side wall (42, 142), the side wall (42, 142) comprising a second connecting region (48) spaced from the second end (38, 138), wherein one of the first (24, 124, 224, 324, 424) and the second (48) connecting regions has a radially outer surface comprising at least one curved section (outer curved section) (30, 230, 330) whose radius increases continuously from a smaller radial distance (R ¹ ) to a larger radial distance (R ² ) from a fixed central point (P), wherein the other of the first (24, 124, 224, 324, 424) and the second (48) connecting regions has a radially inner surface comprising at least one curved section (inner curved section) (60, 260, 360 ) whose radius increases continuously from a smaller radial distance (R ³ ) to a larger radial distance (R ⁴ ) from said fixed central point (P), where the largest radial distance (R ⁴ ) of the inner curved section (60, 260, 360) is greater than the largest radial distance (R ² ) of the outer curved section (30, 230, 330), and the smallest radial distance (R ³ ) of the inner curved section (60, 260, 360) is greater than the smallest radial distance (R ¹ ) of the outer curved section (30, 230, 330), such that one of the first (24, 124, 224, 324, 424) and second (48) connection regions are sized to receive the other, where the largest radial distance (R ² ) of the outer curved section (30, 230, 330) is greater than the smallest radial distance (R ³ ) of the inner curved section (60, 260, 360), such that When one of the first (24, 124, 224, 324, 424) and the second (48) connecting regions is received within the other, the base (10, 110, 210, 310, 410) and the body (34 , 134, 234, 334) can rotate relative to each other from an unlocked position to a locked position in which a contact area (0) between the first connection region (24, 124, 224, 324, 424 ) and the second connecting region (48) extends over at least a portion of the outer (30, 230, 330) and inner (60, 260, 360) curved sections, and where: (i) each of the outer (30, 230, 330) and inner (60, 260, 360) curved sections extends over at least 60 ° in a circumferential direction, optionally in which the first (24, 124, 224 , 324, 424) and the second (48) connecting regions each comprise at least 2 outer (30, 230, 330) and inner (60, 260, 360) curved sections, respectively; or (ii) the first (24, 124, 224, 324, 424) and the second (48) connecting regions each comprise at least 2 outer (30, 230, 330) and inner (60, 260, 360) curved sections , respectively, wherein the outer curved sections (30, 230, 330) extend in total over at least 200 ° in a circumferential direction, and the inner curved sections (60, 260, 360) extend in total over at least 200 ° in a circumferential direction; or (iii) the contact area (0) extends over at least 90 ° in a circumferential direction. 2. The feeding system according to claim 1, wherein the first (24, 124, 224, 324, 424) and the second (48) connecting regions each comprise at least 2 outer curved sections (30, 230, 330) and inner (60, 260, 360), respectively, and wherein the outer curved sections (30, 230, 330) extend in total over at least 300 ° in a circumferential direction, and the inner curved sections (60, 260, 360) extend in total over at least 300 ° in a circumferential direction. The feeding system according to any preceding claim, wherein the first (24, 124, 224, 324, 424) and the second (48) connecting regions each comprise no more than six curved sections. The feeding system according to claim 3, wherein the first (24, 124, 224, 324, 424) and the second (48) connecting regions each comprise no more than three curved sections. The feeding system according to any of the preceding claims, wherein the fixed central point (P) coincides with the axis of the hole of the base (10, 110, 210, 310, 410) and / or the body (34 , 134, 234, 334). The feeding system according to any preceding claim, wherein the first connecting region (24, 124, 224, 324, 424) has a radially outer surface comprising the at least one section outer curve (30, 230, 330) and the second connecting region (48) has a radially inner surface comprising the at least one inner curved section (60, 260, 360), such that the first connecting region (24, 124, 224, 324, 424) of the base (10, 110), 210, 310, 410) is received within the second connection region (48) of the body (34, 134, 234, 334). The feeding system according to any one of the preceding claims, wherein the base (10, 110, 210, 310, 410) and the body (34, 134, 234, 334) are manufactured from different materials. The feeding system according to any preceding claim, wherein the feeding system further comprises a cap for closing the second end (38, 138) of the body (34, 134, 234, 334). The feeding system according to any preceding claim, wherein the body (34, 134, 234, 334) comprises at least one Williams wedge (172a, 172b). A feeding sleeve assembled from the feeding system (100, 200, 300) according to any of claims 1 to 9, wherein the body (34, 134, 234, 334) is mounted on the base (10 , 110, 210, 310, 410), and wherein one of the first (24, 124, 224, 324, 424) and the second (48) connection regions is received within the other of the first (24, 124 , 224, 324, 424) and the second (48) connecting regions.