JPH05230506A - Integrally constructed, metal-made tablewear part - Google Patents

Abstract

PURPOSE: To provide a simple and economical manufacturing method by manufacturing a metal tableware part by powder metallurgy and constituting it as a single body from a sintered metal. CONSTITUTION: A metal tableware part of integral structure, particularly a metal part of knife, fork, or spoon set 1, is manufactured by powder metallurgy and constituted as a single body from a sintered metal. The tableware part is formed of at least two alloy compositions over the whole length. One of the alloy compositions has relatively high hardness. The manufacturing is carried out by using die pressing and sintering of metal powder. By this method, the stainless steel tableware part requiring no restriction on the kinds of shape and its moldability can be manufactured.

Description

Detailed Description of the Invention

The present invention is directed to monolithic metal tableware parts, such as knives, forks and spoons, especially knives,
Fork and spoon set tableware.

Known to date, commercially available, expensive,
Tableware parts made of steel or silver, especially stainless steel chrome-nickel steel or silver, must be manufactured by an expensive manufacturing method. The manufacturing method for producing silver-plated nickel-silver tableware parts and chrome-nickel-steel tableware parts is almost the same.

Knife and spoon dish parts are cut as a single piece from a steel plate. Brandern
This cut, called the eln), must be sharpened and blunt rolled. Branderns for the production of spoon tableware must be rolled to a thinner material thickness in the area of the spoon to be subsequently formed. The forks and spoons Brandelund must then be trimmed to a size that matches the model. Before the dish parts are given their shape and their decoration by the stamping process, washing and tempering operations are added.

The embossing process causes inevitable protrusion from the "high ante" of the tableware portion. This protrusion must be removed by polishing, and only then can the surface be made flat and glossy by the grinding and polishing steps. Then, a washing process is performed to complete the manufacturing process of the chrome-nickel steel tableware portion.

The above list alone has already shown how costly to manufacture. In tableware production, expensive tableware production is relatively expensive, as problems in individual steps have largely hindered mechanization. Many steps also result in long manufacturing process times.

In order to be able to decorate this in the knife tableware in the same way as a similar spoon and fork,
It must be assembled and manufactured. The knife grip is welded from two petri dish halves, previously deformed from one plate strip. The blade is fixed to the hollow knife grip, in particular by welding or cementing. For knives of this kind, the grip is made of chrome-nickel steel, which has a good surface finish.
However, the blade is made of hardened, resilient stainless steel.

To avoid this costly manufacturing method, methods of manufacturing monoblock knives are known. In this manufacturing method, a knife as a unit is manufactured from a hardenable chromium-nickel steel by rolling and / or forging.

However, various requirements, such as mechanical strength and scratching strength for gripping and, on the other hand, cutting force and elasticity for blade blades, are optimally met when using only one type of plate. I can't.

The forging process does not provide the same or similar decoration as the stamping process. The forging process is also very expensive, especially since the surface must continue to be expensively polished. In this case,
A fine decoration cannot be realized. Even if this is applied in forging, it will be removed again in the polishing process. Therefore, a one-piece knife can only have a very simple decoration. Fitting spoons and forks can only be inferred from this simple decoration.

Therefore, in the manufacture of knives, forks and spoons, the shape and decoration are very limited by the manufacturing method.

The usual tableware parts for carrying dishes from plate to mouth have changed little over the last few hundred years. This is related to the manufacturing method not being able to cost-effectively manufacture other shapes.

In practice, however, so that the dish can be more easily received from the plate and delivered more reliably to the mouth,
Forming tableware is required. Further, it is required that the spoon fits better in the mouth than ever before, and the handle of the tableware portion is formed so as to be easy to grip. In addition to this, there is a desire to be able to produce industrial wares with rich decorations and excellent, well-defined shapes.

The object of the present invention is to make a simple and economical manufacturing method, produced by powder metallurgy, which, in addition to the usual simple shape, limits the shape and the type of its shaping possibilities. It consists in producing stainless steel tableware pieces which require no or very little.

The subject of the present invention is a new tableware part of the type characterized in the main part of claim 1, the subclaims
17 is a tableware part having the advantageous and / or purposeful shape described in 17.

The tableware part according to the invention is relatively technically inexpensive to manufacture, deformable, and, in a good and partially improved usability without change, an increasingly internationalized eating habit. Enables any novel dish shape that is advantageous and purposeful for. The tableware part according to the invention offers all possibilities for the latest improvements and progressive shapes.

For the production of the tableware part according to the invention:
Known powder metallurgy methods are useful for other purposes. Many methods are known for obtaining sintered metal materials from metal powders by pressing and sintering and for producing working materials by powder metallurgy. By these methods, the tableware part according to the invention can be manufactured and shaped.

Known methods of manufacture include, for example, hot forging of metal powders or metal powder mixtures filled in sheet metal capsules (Blechkapsel), isostatic pressing, explosive compression of metal powders or metal powder mixtures and temporary binders. Casting or extrusion or injection molding of the kneaded or mixed metal powder mixture and the subsequent removal of the binder from the "green cast" and the sintered body of the green cast.

For example, the metal powder is placed in a sheet metal capsule formed corresponding to the tableware part from which the metal powder is to be produced, which is evacuated, the powder mixture is mechanically compressed and then placed in a closed capsule. And sinter in the open state. In particular, special tools are useful for compressing the metal powder in the form of fine images, such as representing dish parts; for example by means of spring resilience, hydraulic and / or pneumatic cylinders, matr
controlling the die speed relative to the movable stamp during the compression process so that the die follows a predetermined speed when the top stamp descends in the case of a fine image, which can ensure accurate positioning of the size). You can Also in the case of special forging machines, the metal powder mixture contained in the sheet metal capsules can be subjected to the forging-sintering process or after being pressed by rollers and then demolded. The material of the sheet metal capsule is reusable.

This can be cold isostatically or hot isostatically (so-called HIP method) pressed.

The so-called MIM process (metal injection molding) is used for the production of tableware parts according to the invention which have a complex shape, for example a special decorative shape of the table-grip part or a particularly "exotic" tableware structure. Is also advantageous. In this case, the metal powder is mixed with a plasticizing binder or mixture of binders, for example admixed or suspended, the admixture mass or suspension (dross) is degassed, and the mold corresponding to the tableware part to be produced. In a die, for example, or by extrusion or injection molding with a suitably shaped injection molding tool (so-called PM injection molding), followed by removal of the binder from the green casting, The work casting is sintered and / or pressed to obtain the finished tableware part. The starting material for the tableware part according to the invention is obtained by commerce. Metal powders of different metals are offered on the market in different particle sizes and granules, especially in relatively small particle sizes, spherical and droplet granules. Such metal powders having a small particle size of up to about 60 μm for the tableware parts according to the invention are particularly useful. Two
Metal powders having a particle size of up to 0 μm are particularly desirable for the production of the tableware parts of the invention by injection molding. The specific composition of the starting metal powder for the production of the tableware part according to the invention is
It is specifically tailored to the properties desired for the finished tableware part. In addition to the usual sheet metals, the metal powder mixture as the starting material also gives alloys which cannot be obtained by the usual melting process, which leads to materials with properties suitable for the intended use of the tableware part according to the invention. Can be reached.

In the tableware part according to the invention, the properties of the tableware part can be appropriately influenced within a relatively wide range by the composition of the metal powder mixture used for the production. The metal composition is no longer limited to the alloy phase. A wide variety of chemical compositions can be formed by powder metallurgy, and the shape and size of differently formed powder particles and the mixing ratio can influence the properties of the finished tableware part during its manufacture. .. The unitary tableware portion according to the present invention may include more than one alloy composition along its entire length. Particularly advantageous is a single knife-tableware part according to the invention, the blade part of which has a greater hardness than the elongated handle part.

Depending on the composition of the metal powder-starting mixture and, depending on the particular manufacturing conditions selected, the tableware part according to the invention can have in part the desired porosity,
It may also have a decorative coating at least partially, for example on the grip. The tableware part according to the invention can have sheet metal anywhere on its surface with functional and / or decorative elements of sheet metal which cannot be manufactured by technically industrial manufacturing methods. They can also be surface-treated in a manner known per se and can be provided with decorations, for example by lacquering or enameling. The surface of the tableware part according to the invention can be partially advantageously decorated by the method described by the applicant in DE 1298384. It is also possible to perform silver plating by a method known per se.

The tableware part according to the invention only requires a small amount of material use, since it does not actually produce any processing waste during its manufacture compared to sheet metal technology.

Example 1 Stainless C having the following composition (% by weight) and particle size distribution
Atomization hardening (zerstaubt) of r-Ni steel
es vorlegiertes) metal powder was used: C 0.05 mesh width <0.150-> 0.075 Cr 17.32 mesh width <0.075-> 0.045 Ni 9.2 mesh width <0.045 Fe The rest mesh width <0.045 The powder mixture was filled into a spoon-shaped press die, and the mixture was poured to about 6500.
Compressed from both sides using a bar press pressure. A spoon-shaped raw cast product is obtained, which is
Sintering was performed for 3 hours at a sintering temperature of 300 ° C. After sintering, the density was 92% of theoretical density. Then, it is re-compressed with the first press pressure and then newly re-compressed for 1 hour under hydrogen atmosphere for 1,30 hours.
Sintered at 0 ° C. This gives a theoretical density of 96
A sintered metal spoon having a density of% was obtained. The sintered metal spoon thus obtained was degreased with acetone to remove surface dirt, dried at 80 ° C., washed with aqueous ammonia and finished at 150 ° C. under vacuum.

The spoon thus obtained had excellent usability, scratch resistance and corrosion resistance.

Example 2 A metal powder mixture having the following composition and particle size distribution was used to make spoons: 18 parts Ferrochrome particle size 10-30 μm 6% Cr, 0.2% C, 0.05% Si, balance Fe. 9 parts Carbonyl-nickel particle size 0.5-10 [mu] m 73 parts Carbonyl-iron particle size 0.5-10 [mu] m Powder of 2.5 vol% polyethylene oxide as a dispersion aid and 50 vol% xylol as a suspending agent in a ball mill. Injected inside. A well-mixed, sticky, powdery metal mass was obtained. Granular polyethylene was used as a binder. Known for the production of foam strips, for example the specialist magazine "Plastverarb"
eitet "32, 1981, No. A tandem extruder was used, as described in page 8,948. The homogenizing extruder of the tandem apparatus was formed with two supply ports spaced by 20D (screw diameter). Binder granules were continuously fed into the first feed port and melted in the screw. The powder metal suspension was continuously supplied to the second supply port and mixed in the binder melt. The melt homogenization process was controlled by the screw speed. The screw length of the homogenizing extruder, calculated from the mixing distance, i.e. powder metal mass-feed port, was 12D. After this, the homogenized powder-binder melt reached a cooling extruder containing a degasser, which removed the solvent present in the melt. At the screw head, the solvent-free molding batch is compressed and extruded from a nozzle into a spoon mold. From the release-free spoon body (raw casting), which consisted of 63% by volume of powdered metal and 37% by volume of binder and was practically free of pores, the binder was then removed by heating. In addition, the raw cast product is heated at a heating rate of 15 ° C / min in a continuous heating furnace for
Heat to 0 ° C. and maintain at this temperature for 5 hours. The resulting decomposition products (essentially water, CO ₂ , traces of thermal decomposition products) were continuously removed from the furnace chamber by diffusion. Then, the spoon body containing no binder was subjected to 0.01 in a sintering furnace.
Sintered under 1 mb pressure at 1260 ° C. for 10 hours and then slowly cooled to room temperature. The spoon thus obtained was finished by the usual mechanical post-treatments, which had an excellent appearance and a very good usability.

In the accompanying drawings, the tableware portion according to the present invention will be described by way of example.

FIG. 1 is a plan view of an embodiment of the spoon tableware portion.

FIG. 2 is a side view of the spoon tableware portion of FIG.

FIG. 3 is a sectional view taken along the line I--I of FIG.

FIG. 4 is a sectional view taken along line II-II of FIG.

FIG. 5 is a plan view of another embodiment of the spoon tableware portion. FIG. 6 is a plan view of still another embodiment of the spoon tableware portion.

FIG. 7 is a transverse sectional view of the lower portion of the spoon tableware portion.

FIG. 8 is a cross-sectional view of another lower portion of the spoon tableware portion.

FIG. 9 is a cross-sectional view of still another lower shape of the spoon tableware portion.

FIG. 10 is a vertical sectional view of the lower-handle shape of the spoon tableware portion.

1 to 4, a stainless steel spoon 1 having a spoon lower portion 2 and a handle 3 as a single unit made of sintered metal will be described. Spoons are manufactured by powder metallurgy. The lower part 2 of the spoon--as is apparent from FIGS. 1 and 2--is asymmetric with respect to the longitudinal and transverse axes. The contour edge 4 of the lower part 2 of the spoon forms a curve and has an inflection point.
This curve consists of a total of three curves which are discontinuously adjacent to each other. The lower part of the spoon has a dent 5 on its front side. As is apparent from FIG. 3, one of the dents 5a is larger in size than the other dent 5b. further,
As can be clearly seen in FIG. 3, the thickness distribution under the spoon is discontinuous. The lower part of the spoon is thicker in the indentation 5b near the contour edge 4 than in the indentation extending to the center of the lower part, and in the indentation 5a the material thickness of the contour edge 4 is smaller than in the lower center. The lower part 2 of the spoon, as shown in FIG. 1, has a pattern 6 on its front side, which serves for a more decorative construction and at the same time also for characterizing the various indentations 5 in the lower part 2 of the spoon.

The variable thickness-configuration of the lower portion of the spoon improves the usability of the spoon. It is possible to separate the dishes on this spoon by different indentations 5a and 5b defined from one another so that the spooned dishes can be dropped separately from the lips, eg liquids and solid substances. The spoon 1 has three wing openings (dreifluegliger Durc) within the range of transition from the lower part of the spoon 2 to the handle 3.
hbruch). This opening serves a decorative purpose. However, it can also be used to drain liquid from the bottom of the spoon under certain usage conditions of the spoon. The opening 7 is connected to the pattern 8 on one side and to the arcuate line of the constriction 9 on the other side. Pattern 3 shows a panoramic image (Rundum-anisicht). The handle 3 is formed by structural elements that are mixed and migrate over the entire surface. The handle 3 moves from the neck 9 of the handle to the grip portion 11 with the gradually tapering profile 10. Profile 10 is
As shown in FIG. 4, the cross section is irregularly formed from various curves and undercuts (Hinterschnitte). Both the cross section and the shape of profile 10 vary over the length of the profile. For example, in the center of the handle 3, the handle 3 becomes thicker in several steps up to the grip portion 11.
The grip portion 11 extends discontinuously in its cross section up to the handle end 13. The profile 12 of the grip portion 11 is inclined to the handle end portion 13 by a notch (Schnitt) which makes an angle with the handle length axis. As shown in FIG. 2, the grip portion 11 has an oval opening 14.

The spoon 15 shown in FIG. 5 comprises a spoon lower portion 16 and a handle 17 as a single body, and is made of a sintered metal made of stainless steel. It was manufactured by powder metallurgy. The lower part of the spoon 16 has a straight edge 1 on one side.
Formed by 8. With such a spoon according to the invention, dishes, in particular liquids, are advantageously scooped from the dishes. The material distribution in the cross section of the lower part 16 of the spoon is discontinuous. The thickness of the lower part of the spoon is thinner at the straight edge 18 than on its opposite side. With such a material distribution, spoons are also suitable for easy dispensing of dishes.

In FIG. 6, in the spoon lower shape in which the tip 22 of the lower portion of the spoon changes into a rounded conical shape, the spoon dish 20 is made of stainless steel and is composed of the lower portion 20 of the spoon and the handle 21 according to the present invention. A portion 19 is shown. In the lower part of this spoon, there are lateral edges 23a and 23b on both sides which run in a substantially straight line, which exert the same effect of use as described above in connection with the shape according to FIG.

FIGS. 7-10 show another novel type of spoon shape, which could not be industrially manufactured by the conventional spoon tableware part.

The lower part of the spoon shape 24 shown in FIGS.
26, 29 advantageously have a thin spoon bottom material, which is preferred and produces a very light tableware piece.
Since the edge stiffeners 25 and 27 ensure the required use stability according to the embodiment according to FIGS. 7 and 8, the tableware part according to the invention thus formed has a low material thickness underneath the spoon. Instead, it has a rounded finish and is stable in use due to the thick spoon bottom rim. In the embodiment of FIG. 8, the lower part 26 of the spoon is formed so as to project outward on one side. The lower rim 28 of the spoon does not transition in one plane, which also has a positive effect on usability.
The lighter spoon lower part 29 of the very thin material shown in FIG. 9 has a spoon lower edge 30 which is bent and formed without reinforcement, this edge guarantees the necessary stability of use and is uncomfortable to handle and use. is not.

FIG. 10 is a tableware part according to the present invention made of a sintered metal, a spoon lower part 31 and a handle 33 as a single body.
Shows a spoon shape consisting of and, in this spoon shape, handle 3
3 starts already from the side edge 32 and / or the lower part of the spoon increases in thickness towards its handle 34, with a continuous transition to a thick handle neck. By this treatment, the bending strength at the critical point of the constriction of the tableware is increased,
This is a particularly stable use embodiment.

It is self-evident that the structural features shown in the drawing of the spoon-tableware part are realized comparatively in the fork and knife dish part according to the invention.

It is also possible for the tableware parts, such as spoons, forks, knives, of conventional construction, to be formed in one piece from sintered metal according to the invention, which is advantageous depending on the material and the manufacturing method.

The tableware parts according to the invention, which are produced by powder metallurgy, are subsequently processed by a polishing process so that they have the same surface properties as conventional tableware parts produced by deformation from sheet metal and polished. It is possible to have it.

[Brief description of drawings]

FIG. 1 is a plan view of an embodiment of a spoon dish portion.

2 is a side view of the spoon tableware portion of FIG. 1. FIG.

FIG. 3 is a sectional view taken along line I-I of FIG.

FIG. 4 is a sectional view taken along line II-II of FIG.

FIG. 5 is a plan view of another embodiment of the spoon tableware portion.

FIG. 6 is a plan view of yet another embodiment of the spoon tableware portion.

FIG. 7 is a cross-sectional view of the lower portion of the spoon tableware portion.

FIG. 8 is a cross-sectional view of another lower shape of the spoon tableware portion.

FIG. 9 is a cross-sectional view of yet another lower shape of the spoon tableware portion.

FIG. 10 is a vertical cross-sectional view of the bottom-handle shape of the spoon tableware portion.

[Explanation of symbols]

 1. Spoon 2. Lower part of the spoon 3. Pattern 4. Contour edge 5. Indentation 6. Pattern 7. Opening 8. Pattern 9. Constriction 10. Profile 11. Grip part 25, 27. Edge reinforcement 30. Bottom edge of spoon

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hans-Friedrich Feese Federal Republic of Germany Day-7342 Bad Ditzzenbach, Lindenstraße 11 (72) Inventor Rolf Ritter German Republic Day-7340 Geislingen / Steige, Germany Over Boehringer Straße 22

Claims (17)

[Claims] 1. A monolithic metal tableware part, in particular a metal part of a knife, fork, spoon set,
A tableware piece manufactured by powder metallurgy and composed of a sintered metal as a single piece. 2. A tableware part according to claim 1, characterized in that it consists of at least two alloy compositions over its entire length. 3. The tableware portion of claim 2 wherein one of the alloy compositions has a relatively high hardness. 4. Tableware part according to claim 2 or 3, characterized in that one of the alloy compositions is curable. 5. A die press of metal powder (Matritz)
5. A tableware part according to any one of claims 1 to 4, characterized in that it is manufactured using enpress) and sintering. 6. The tableware part according to claim 1, which is produced by cold or hot isostatic pressing of metal powder and sintering. 7. A tableware part according to any one of the preceding claims, characterized in that it is produced by insert in a mold shell, pressing and / or rolling and sintering. 8. The tableware part according to claim 1, which is manufactured by a powder metal injection molding method. 9. A plastic functional element and / or a decorative element, which cannot be produced by a sheet metal technically industrial production method, is present at any arbitrary position of the tableware portion. Tableware part of 8. 10. Tableware part according to any of the preceding claims, characterized in that it is at least partially surface-treated and / or decorated in a manner known per se. 11. The tableware portion of claim 10, wherein the tableware portion is at least partially enameled. 12. The spoon lower part (16) has a straight edge (18) on one side, as defined in claims 1 to 11.
The tableware part of the spoon described in any of 1. 13. The edge tip (22) is rounded and has a conical edge shape including linear side edges (23a and 23b) on a part of both sides. The spoon tableware part according to any one of 1 to 11. 14. The spoon tableware portion according to claim 1, wherein the periphery of the rim has a reinforcing material. 15. The rim periphery has a raised curvilinear transition at least on one side of the rim.
4. The spoon tableware part according to any one of 4 above. 16. The spoon and fork tableware portion according to claim 1, wherein the thickness of the edge continuously transitions to the constricted portion of the handle. 17. Spoon and fork according to any of claims 1 to 16, characterized in that the edge thickness is asymmetric in cross section and decreases from one side to the other. Tableware part.