Methods, patterns and devices for forming composite material devices

Abstract

To provide a method of forming a device of a composite material.SOLUTION: The method includes: providing a mold having an internal space forming a cavity with an inner surface having a shape corresponding to an inner shape of a device to be formed; placing inserts at one or more predefined positions along the inner surface; holding the inserts at the one or more positions; introducing removable material into the cavity of the mold to form a pattern having the inserts fixed therein when the removable material is in a solid form; and removing the pattern having the inserts fixed therein from the mold.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to a method for forming a composite material device, a pattern for a composite material device, and a composite material device, during which method inserts and / or functional components are essentially embedded in said pattern and / or said device. [Background technology]

[0002] Composite materials are often used to form lightweight, high strength devices (also called composites) in place of metallic devices such as vehicle panels, device housings, etc.

[0003] Composites are further used to form panels, frames, interior components, housings, and the like, and are used to form lightweight, stable parts in, for example, vehicles, sporting goods, electronic applications, robotics, composite equipment, tools, and the like. Summary of the Invention [Problem to be solved by the invention]

[0004] During the formation of such devices, it can be very difficult to embed functional components, especially those with close tolerances or components that are aligned with one another, into the device during manufacturing. This can be particularly relevant, for example, during the manufacture of vehicle panels, parts for robotics, tools, and electronic applications.

[0005] It is therefore an object of the present invention to make available a device and a method for manufacturing the device having functional components embedded therein. Another object is to make available a device having functional components embedded therein which are aligned with one another. Yet another object is to make available a relatively low-cost method for manufacturing such components. [Means for solving the problem]

[0006] This object is met by a method for forming a composite material device having the features set forth in claim 1.

[0007] The method is: providing a mold having an interior space forming a cavity having an interior surface, the cavity having a shape corresponding to an interior shape of a device to be formed; positioning an insert at one or more predetermined locations along the inner surface; holding the insert at the one or more positions; introducing a removable material into the mold, the removable material being in the cavity of the mold to form a pattern with an insert secured therein when the removable material is in solid form; removing the pattern with the insert secured therein from the mold; Includes.

[0008] The use of patterns to form parts of composite moulds is well known for producing composites with well-defined internal structures. The general idea underlying the present invention is to embed inserts forming either the functional parts or the supports for the functional parts directly into a removable pattern at predetermined locations, so that they can be embedded in the composite device at said predetermined locations. In this way, complex housing structures can also be formed. The use of patterns thus makes available a cost-efficient production of composites.

[0009] In this regard, the support for the functional component may be a negative of the functional component and may include undercut recesses or the like that are used to connect the functional component to the composite.

[0010] The step of retaining may include retaining the insert through application of a vacuum, the use of sliders, functional elements, and / or the use of magnets. In this way, the insert may be retained in a simple and reproducible manner.

[0011] The insert may include at least one of a magnetic material and a metal. Such an insert may be held in the pattern mold in a suitable manner.

[0012] The insert may be shaped to form a functional component or may be formed by, i.e. be a functional component of, the device. In this way, either a functional component or a support for a functional component may be embedded directly in the pattern and later included in the device, either directly or with a support formed by the insert.

[0013] The removable material pattern may be manufactured by an injection molding process or a wax casting process, which allows for rapid and cost-effective manufacture of the pattern.

[0014] The removable material is introduced into the cavity in liquid form, thus ensuring that the entire inner surface of the mould is covered with removable material to create a pattern of the desired outer shape.

[0015] The step of introducing the removable material into the mold may include filling 40-99% of the cavity with liquid removable material, in this way minimizing the effects of shrinkage on the outer surface of the pattern.

[0016] The method may further comprise the step of introducing a gas into the removable material present in the mold and pressurizing the removable material present in the mold with a pressure differential selected within the range of 0.02 to 20 bar between the outside of the formed pattern and the hollow space within the pattern, in this way the effect of shrinkage on the outer surface of the pattern can be further minimized.

[0017] The method may further comprise the step of applying a pressure in the cavity selected in the range of 0.02 to 0.95 bar, in particular 0.05 to 0.5 bar, before introducing the removable material into the cavity, in such a way that a pattern having an outer surface at least substantially free of defects can be suitably formed.

[0018] The method includes the steps of moving the mold to completely coat the interior surface of the mold with the removable material in liquid form; and solidifying the removable material in the mold. The centrifugal or gravitational force acting on the removable material can further prevent shrinkage effects at the surface of the pattern, thereby obtaining a pattern with inserts securely positioned at predetermined locations on the outer surface of the pattern for forming functional components at predetermined locations on the inner surface of the device.

[0019] The method may further include covering the pattern having the insert with one or more layers of a web of fibrous material. Covering the pattern with one or more layers of a web of fibrous material may form a composite device having an inner shape corresponding to an outer shape of the pattern.

[0020] In this connection, it should be noted that the pattern can be used as part of a mould for the so-called Resin Transfer Moulding (RTM) process: in this case, the mould can be covered with rovings and then inserted into another mould for adding resin and heat treating to form the final device in the composite material in a manner known per se.

[0021] In this context, it should be noted that each web of fibrous material can be a layer of fabric made from woven fibers, created by interlacing two or more tows of fibers at right angles to each other. Additionally or alternatively, a web of fibrous material can be formed by fiber tows. In this context, a fiber tow is a bundle of fibers, such as threads.

[0022] In this regard, it should be further noted that, although tows of fiber can be applied at the location of the insert to reinforce the insert in the finished device, the woven fabric can be introduced in areas representing the inner and / or outer surface of the device.

[0023] The layer or layers of fibrous material, either dry or as prepregs, can include natural fibers such as carbon fiber, glass fiber, basalt fiber, wood fiber, as well as hemp fiber, aramid fiber, polyester fiber. Such fibers can be beneficially used in the formation of composite devices. In this regard, it should be noted that a prepreg is a layer of fibers that includes an adhesive.

[0024] The method may further comprise the step of placing said pattern having an insert and covered with one or more layers of fibrous material into another mold, such that one or more layers of the web of fibrous material are held within the other mold between the pattern and the inner surface of the other mold, forming a predetermined inner and outer shape of the device via the one or more layers of fibrous material.

[0025] The method may further include heating the other mold to a first, second, and / or third temperature within the first, second, and / or third temperature ranges. By selecting an appropriate heating step, the resin may be transported to a desired location within the mold, the resin may be cured within the mold around one or more layers of fibrous material, and the removable material may be removed from said mold.

[0026] The first, second, and third temperatures can be used for at least one of heating the mold to aid in the introduction of resin into the mold, heating the mold to harden the material of the device being formed, and removing removable material of the pattern, such as wax.

[0027] It should also be noted that the first temperature range is preferably a temperature range of ±3° around the desired first temperature. The first temperature is preferably selected between 30 and 85°C, in particular between 50 and 80°C.

[0028] It should also be noted that the second temperature range is preferably a temperature range of ±3° around the desired second temperature. The second temperature is preferably selected between 60 and 105° C., preferably between 70 and 95° C. In this connection, it should be noted that it is also possible to gradually adapt the temperature over the entire temperature range in stages.

[0029] It should also be noted that the third temperature range is preferably a temperature range of ±3° centered on the desired third temperature. The third temperature is preferably selected between 80 and 130°C, preferably between 95 and 120°C.

[0030] The method may further include the step of introducing a resin into the other mold before and / or during the step of heating the mold to the first temperature, optionally applying a vacuum during the step of curing the resin. By applying temperature and / or vacuum, the resin may have a more flowable consistency than at room temperature, thereby flowing better into the voids between one or more layers of fibrous material disposed between the pattern and the inner surface of the cavity. By introducing resin into the other mold to coat one or more layers of a web of fibrous material in the space between the inner surface of the other mold and the outer surface of the pattern, a composite device may be formed with a functional part essentially formed in the wall of the device at the location of the insert present in the pattern, and with a desired inner and outer shape.

[0031] The method may further include curing the resin in the other mold to form the device, the curing step including at least one of heating and applying UV light. Such a method step may beneficially harden the removable material.

[0032] The step of applying heat may include heating the other mold to the second temperature, which is a fast and efficient way to cure resin in one or more layers of the web of fibrous material.

[0033] The resin may be heated to a second temperature, for example below the curing temperature of the resin, when it is introduced into the other mould, in such a way that the resin can be transported more efficiently around the layer or layers of the web of fibrous material present in the other mould, to avoid the inclusion of air bubbles which may reduce the quality of the housing at the location of the air bubbles.

[0034] The resin may be one of a one-component resin, a two-component resin including a hardener, and a multi-component resin including one or more hardeners. The resin may include an epoxy-based resin, a polyurethane-based resin, a cyanate ester, or another base resin suitable for injection or pouring. Such resins may be beneficially used in the formation of composite devices.

[0035] The method may further include removing the removable material from the device. In this manner, the pattern may be removed without destroying the composite device. The method may further include heating the other mold to a third temperature. Heating the removable material to a temperature above the melting point of the removable material allows for rapid removal of the removable material.

[0036] In this regard, it should be noted that the third temperature step can be carried out in a further apparatus such as an oven or furnace.

[0037] According to a further aspect, the present invention relates to a pattern of removable material, optionally formed by the methods described herein, the pattern including one or more inserts disposed at one or more predetermined locations along an outer surface of the pattern, such a pattern can be beneficially used during the manufacture of a composite device.

[0038] The pattern of removable material may have a melting point selected in the temperature range of 80-130° C., preferably in the range of 95-120° C. The pattern of removable material may remain shape stable to a temperature selected in the range of 60-100° C., preferably in the range of 70-95° C. The pattern of removable material may remain shape stable at temperatures below the melting point of the removable material. These properties of the pattern make it particularly suitable for low-cost, high-precision manufacturing of composite devices.

[0039] According to a further aspect, the invention relates to a composite material device, optionally formed by the methods described herein, comprising one or more functional components disposed at one or more predetermined locations along an inner surface of the pattern, the functional components being either integrally formed with the device or embedded within a structure integrally formed with the device.

[0040] The functional part may be selected from the group of members consisting of tappets with undercuts, pockets with undercuts, internal seats (cylindrical), bearing seats optionally with an insertion point for a circlip, T-grooves (outwardly formed and inwardly formed), external threads such as a bolt or stud with an external thread, internal threads such as a sleeve with an internal thread or nut, bayonet connections, open wedge sockets, eyelets, ball studs, dowels and dowel pins (both optionally with an insertion point for a circlip), hooks, spring elements, bearing blocks, bearing blocks with clamps, serrated pins / couplings with or without a bore, sleeves, apertures, supports for one or more of the foregoing, and combinations of the foregoing.

[0041] The device may have a pre-settable wall thickness with a wall thickness tolerance in the range of ±0.5 mm, in particular ±0.1 mm, in particular ±0.05 mm for a wall thickness selected in the range of 1-4 mm, in particular for a length of material of the device cut in a width selected in the range of 0.5-2.5 cm, in the range of 1-5 cm from the device, such tolerances being impossible with hollow devices using prior art moulds.

[0042] The device may have a wall thickness tolerance in the range of ±0.3 mm, in particular ±0.2 mm, very preferably less than 0.05 mm, for a wall thickness selected in the range 1-4 mm.

[0043] The device may have a surface profile tolerance of ±0.1 mm. In this manner, devices having particularly smooth surfaces may be achieved with the present teachings.

[0044] In this context, it should be noted that surface profile tolerance is a standard measurement technique used to define the surface quality of an object. The more uniform the surface, the lower its tolerance. The surface profile is defined by a uniform boundary around the surface where the surface elements must reside. A surface profile is a complex tolerance that simultaneously controls the shape, size, orientation and sometimes location of features. A surface profile is a three-dimensional tolerance that applies in all directions, regardless of the drawing view in which the tolerance is specified. It is typically used for parts with complex outer shapes and constant cross sections such as extrusions.

[0045] To measure the tolerance of a surface profile, two planes are placed around the surface whose tolerance profile is to be measured, and the tolerance is defined by the spacing between the planes placed around the surface.

[0046] The device may have a surface profile tolerance of ±0.05 mm, in particular ±0.03 mm, in particular ±0.01 mm at the location of the functional part forming the second insert. Such a device has a particularly smooth surface.

[0047] Two or more inserts may be provided, the angular tolerance of the positioning between two inserts in the device may be less than 0.3°, preferably less than 0.2°, and if two or more inserts are fixed to each other in a pattern, the angular tolerance between two inserts may be less than 0.1°, preferably less than 0.05°. Two or more inserts may be provided, the axial tolerance of the positioning between inserts in the device may be less than 0.2mm, preferably less than 0.1mm, and if two or more inserts are provided and fixed to each other in a pattern, the axial tolerance between two inserts may be less than 0.1mm, preferably less than 0.05mm. Two or more inserts may be provided, the positioning tolerance between inserts at the spacing between inserts in the device may be less than 0.1mm+1mm / m, preferably less than 0.05mm+0.5mm / m, and if two or more inserts are fixed to each other in a pattern, the positioning tolerance between two inserts may be less than 0.05mm+0.5mm / m, preferably less than 0.05mm+0.2mm / m.

[0048] The device may be a golf club head and the one or more functional components may be selected as at least one of a weight integrated into the golf club, a shaft connector insert forming a connector to the shaft of the golf club, and a surface that functions as the face of the golf club. Using the above methods, golf clubs can be made that have a very favorable weight distribution.

[0049] One or more functional parts may be provided to function as one or more weights of the head, one functional part may be provided to function as a shaft connector insert, and one functional part may be provided to function as a face of the golf club head. In this way, one or more weights may be formed separately from the face, which results in a particularly favorable weight distribution in the golf club head. In this connection, it should be noted that both iron and wood heads may be formed in this manner, particularly using the method described herein. By embedding the shaft connector insert, the angular accuracy of the face relative to the shaft position may be increased compared to prior art golf clubs.

[0050] Further embodiments of the invention are described in the figures attached hereto and in the following description of the dependent claims. The invention is explained in more detail below by means of embodiments and with reference to the illustrated drawings. [Brief description of the drawings]

[0051] [Figure 1] 1 is a perspective view of functional components disposed at one or more predetermined locations along an inner surface of a device. [Diagram 2] FIG. 1 is a partial schematic cross-sectional side view of a mold for forming a pattern for a device showing various inserts. [Diagram 3] FIG. 2 is a partial schematic cross-sectional side view of a mold for forming a pattern for a device showing an insert present within the mold. [Figure 4] 1 is a partial schematic cross-sectional side view of a mold for forming a pattern for a device filled with a removable material in a device around the insert. [Diagram 5] 5 is a cross-sectional view similar to FIG. 4, with the pattern having the insert embedded therein being removed from the mold. [Figure 6] 6 is a cross-sectional view similar to FIG. 5, but with the pattern covered with a layer of fibrous material. [Figure 7] 7 is a cross-sectional view similar to FIG. 6, but with the covered pattern disposed on another mold. [Figure 8] A cross-section similar to FIG. 7, with the space around the layer of fiber between the pattern and the inner surface of another mold filled with resin. [Figure 9] 9 is a cross-sectional view similar to FIG. 8, with the device being removed from the other mold. [Figure 10] 10 is a cross-sectional view similar to FIG. 9, with the pattern removed from the device. [Figure 11] 11 is a cross-sectional view similar to FIG. 10 with the insert removed from the device. [Figure 12] 11 is a cross-sectional view similar to FIG. 10, with an additional type of functional component essentially present on the interior surface of the device. [Figure 13] 11 is a cross-sectional view similar to FIG. 10, with an additional type of functional component essentially present on the interior surface of the device. [Figure 14] 11 is a cross-sectional view similar to FIG. 10 with a further type of functional component essentially present on the interior surface of the device, the further type of functional component being an insert previously embedded within a pattern. [Figure 15] 15 is a cross-sectional view similar to FIG. 14 with a further type of functional component essentially present on the interior surface of the device, the further type of functional component being an insert previously embedded within a pattern. [Figure 16] Schematic diagram of the internal parts of the device with the bearing support integrally formed therewith. [Figure 17] Diagram of a golf club head. [Figure 18] Diagram of golf club head patterns. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0052] In the following, the same reference numerals are used for parts having the same or equivalent functions. Statements made with respect to the orientation of parts are made with reference to the positions shown in the drawings and may naturally vary depending on the position of the actual application.

[0053] 1 shows a perspective view of functional components 12, 12' disposed at one or more predetermined locations along an inner surface 14 of a housing 16 of a device 10. The functional components 12 may be formed by and within the housing 16 of the device 10 itself. Alternatively, the functional components 12' may be supported directly within the housing 16 of the device 10 by supports formed within the housing 16.

[0054] The functional parts 12' shown in Fig. 1 are the hook 12' and the bolt 12' which are present in the pattern 54 for the device and are formed by inserts embedded in the device 10 during its manufacture. The supports of the functional parts 12 shown in Fig. 1 are the pocket 12 with an undercut, the internal seat 12 (cylindrical), the support 12 for the nut, the bearing seat 12, the inwardly facing T-groove 12 and the sleeve 12.

[0055] The functional part or support for the functional part can be one of the following types of functional parts 12, 12' and is selected from the group of members consisting of tappets with undercuts, bearing seats with insertion points for circlips, outward T-grooves, external threads such as externally threaded bolts and studs, internal threads such as internally threaded sleeves or nuts, bayonet connections, open wedge sockets, eyelets, ball studs, dowels and dowel pins (both optionally with insertion points for circlips), spring elements, bearing blocks, bearing blocks with clamps, sawtooth pins / couplings with or without bores, apertures, supports for one or more of the foregoing, and combinations of the foregoing.

[0056] To form device 10, a pattern 54 (see FIG. 4) of removable material M is first formed in mold 18. FIG. 2 shows a partial schematic cross-sectional side view of mold 18 for forming pattern 54 of device 10. The mold includes upper and lower halves 18', 18'', which together define a cavity 20 having an interior surface 22.

[0057] A seal 19 is present between the upper and lower halves 18', 18'' to seal the cavity from the outside. Such a seal 19 can be formed, for example, by an O-ring.

[0058] The first and second types of inserts 24, 24' are disposed and held on the inner surface 22. The first type of inserts 24 are formed by structures that can be inserted into the cavity 20, for example via sliders 26, and thus protrude into the cavity before and during the manufacture of a pattern 54 for the device 10 to form structures on an outer surface 56 (see FIG. 4) of the pattern 54. The structures can thereby form recesses in the pattern 54 that can be filled with material that forms the device 10.

[0059] The second type of insert 24' is an insert that is intended to remain in the pattern 54 after it has been formed. This second type of insert 24' may likewise form structures on the outer surface 56 of the pattern 54. These structures may form supports for the functional parts 12, i.e. may have a shape complementary to the functional parts 12'. Alternatively, the second type of insert 24' is the functional part 12 (see Figures 14 and 15). The functional parts 12' are then bonded to the device 10 via the structures present on the outer surface 56 of the pattern 54.

[0060] The second type of insert 24' can be held within the mold cavity 20 via one or more magnets 28 or through the application of a vacuum V. To this end, the second type of insert 24' is connected via a vacuum passage 30 to a vacuum pump 32 which is connected to the mold 18 via a vacuum port 36.

[0061] To form a pattern, removable material M (see, e.g., FIG. 4) is introduced into cavity 20 from a container 38 of removable material, which may be wax W. Removable material M is introduced into cavity 20 in liquid form via port 40 and line 42. In practice, the volume of cavity 20 in mold 18 is only filled to between 40-98% with liquid removable material M.

[0062] To pressurize pattern 54, gas G can be introduced into removable material M via gas supply 44 connected to mold 18 via gas port 46 and gas line 48. Additionally or alternatively, cavity 20 can be sealed in that manner or such that gas present within the cavity is compressed upon introduction of removable material M to form pressurized gas G within the cavity.

[0063] As shown in FIG. 4, in each case the gas G creates a hollow space 54' in the pattern 54. The gas fills this cavity 54' and is able to pressurize the removable material M present in the mould 18 so that the wax 20 covers the entire surface of the cavity 20. The pressure difference between the outside of the formed pattern 54 and the hollow space 54' in said pattern 54 is chosen in the range of 0.02 to 19 bar, i.e. the pressure in the hollow interior of the wax pattern can be chosen to be in the range of 1.02 to 20 bar before the wax solidifies, i.e. when the wax is in the molten state. In this connection it should be noted that the pressure in the hollow interior of the wax pattern can be lower after the wax has solidified than before it has solidified, this being due to the contraction of the wax as it solidifies.

[0064] Typically, the wax can be selected to be a wax that melts at a high temperature in the range of 60 to 140° C., particularly 70 to 120° C., and to be solid at a low temperature in the range of 30 to 100° C., particularly 60 to 90° C. The temperature difference between the high and low temperatures is preferably selected to be less than 40° C., preferably less than 30° C., particularly less than 20° C., in particular less than 10° C.

[0065] The waxes may have a viscosity of more than 2000 mPas at temperatures below 85° C. and less than 800 mPas at temperatures above 105° C. It has been found that such waxes are particularly stable in shape up to their melting point, with the transition between the liquid and solid states occurring in a relatively narrow temperature range, making said waxes more cost-effective in their use.

[0066] In forming the wax pattern 54, the mold 18 can be heated to a temperature below the solidification temperature of the wax, in particular to a temperature selected in the range of 1-40° C., in particular 5-25° C. below the solidification temperature of the wax. In this way, the wax can be solidified in a more controlled manner and shrinkage effects at the surface of the wax pattern can be reduced, since the wax does not automatically solidify on contact with the surface of the mold cavity.

[0067] The mould cavity can be evacuated to a pressure selected in the range of 0.02 to 0.95 bar, in particular to a pressure selected in the range of 0.05 to 0.5 bar.

[0068] Following this, the mold can be rotated about one or more axes of rotation. A first possible axis is shown about a vertical axis 36, in which case the mold 18 can rotate in the direction of the arrow shown about the vertical axis 36 or in the opposite direction. A second possible axis of rotation is about a horizontal axis H, in which case the mold 18 can rotate in the direction of the arrow shown about the horizontal axis H or in the opposite direction. By moving the mold 18 in this manner, centrifugal or gravitational forces urge the pressurized removable material toward the inner surface 22 of the mold 18, so that it is completely coated with the removable material, and the resulting pattern has an outer surface 56 that is essentially free of shrinkage and other forms of defects (see FIG. 4). During rotation of the mold 18, it can be cooled, for example using water cooling, resulting in solidification of the removable material M within the mold 18.

[0069] A vacuum can be applied to said mould 18 using a vacuum pump to form a pattern 54 with functional parts 12, 12' arranged at a predetermined position or positions. Once the desired vacuum, for example 0.3 bar, is achieved in the mould 18, a valve can be closed to maintain the pressure in the cavity. A liquid form of a removable material M can then be introduced into the mould 18. For example, 80% of the volume of the mould 18 can be filled with a liquid material M, for example wax W. Residual air in the mould is thereby compressed by the addition of wax W such that the pressure in the mould can range from 1.02 to 4 bar, depending on the initial vacuum pressure and the amount of wax added.

[0070] The pressurized gas within the mold and rotation of the mold then allows the mold 18 to rotate about its axis of rotation while the mold cools, initially allowing the liquid wax to cover the entire surface of the mold and form a wax pattern having an outer shape similar to the inner shape of the mold and a hollow interior bearing the wax pattern.

[0071] When forming a pattern having a particularly complex outer shape, additional gas can be added to the mold before, during, and / or after the addition of the liquid removable material M. Additionally or alternatively, greater than 80% of the volume of cavity 20 can be filled with removable material M. This additional pressure within the mold can direct the liquid removable material into the complex negative shape of the mold, ensuring the formation of a pattern having a substantially defect-free outer surface.

[0072] 3 shows a partial schematic cross-sectional side view of a mold in which, rather than using a movable insert 12 that can move into cavity 20, inner surface 22 of mold 18 includes protrusions 52 thereon that take over the function of insert 12 to form a support structure for functional part 12'. A second type of insert 24' is inserted into mold 18. The left insert 24' is held to inner surface 22 via a magnet. The right insert 24 is held in place via a vacuum V, a seal 50 in the form of an O-ring seal between mold 18 and insert 24'.

[0073] Figure 4 shows a partial schematic cross-sectional side view of the mould of Figure 3 with removable material M introduced therein. Also visible is hollow space 54'.

[0074] Figure 5 is a cross-sectional view similar to Figure 4 with the removable material having solidified and the pattern 54 having been removed from the mold 18. The insert 24' is held in place within the pattern 54 in the outer surface 56. The pattern 54 further includes a recess 58 in the outer surface 56.

[0075] The pattern 54 includes two inserts 24, 24' arranged at one or more predetermined locations along the outer surface 56. The pattern 54 of removable material M may have a melting point selected in the temperature range of 80-130°C, preferably in the range of 95-120°C. The pattern 54 may remain shape stable to a temperature selected in the range of 60-100°C, preferably in the range of 70-95°C. Generally speaking, the pattern 54 of removable material M may remain shape stable at temperatures below the melting point of said removable material M.

[0076] Figure 6 shows a cross-sectional view similar to that of Figure 5, in which the pattern 54 is covered with layers of fibrous material 60, 62. The woven layer of fibrous material 60 is placed directly on the outer surface 56, while tows of fibers 62 are inserted into the recesses and free spaces of the inserts accessible from the outer surface 56 of the pattern 54.

[0077] The layer or layers of fibrous material 60, 62 may include carbon fiber, fiberglass, basalt fiber, wood fiber, hemp fiber, aramid fiber, polyester fiber, either dry or as a prepreg.

[0078] Thus, the pattern 54 of removable material M can be used as a mould in a resin transfer moulding (RTM) process to form a composite device in a manner known per se.

[0079] Figure 7 shows a cross-sectional view similar to Figure 6, but with the covered pattern 54 disposed within another mold 64. The other mold 64 has an inner surface 64'. Thus, layers of fibrous material 60, 62 are disposed between the inner surface 64' of the other mold 64 and the outer surface 56 of the pattern 54.

[0080] Figure 8 shows a cross-sectional view similar to Figure 7 with the space around the layers of fibre 60, 62 between the pattern 54 and the inner surface 64' of another mould 64 filled with resin R. Resin R is introduced from a container 66 via a supply line 68.

[0081] The other mold 64 may be heated via a heating and / or cooling device 96 to a first, second, and / or third temperature within the first, second, and / or third temperature ranges.

[0082] In this regard, it should be noted that when the other mold 64 is heated to one of the first, second, and third temperatures, the heating step can be carried out gradually in steps or continuously.

[0083] It should be noted that especially during the RTM process, the fiber-resin composite is usually heated stepwise below the glass transition temperature of the resin to prevent the device being formed from softening and thereby obtaining a deformed outer and / or inner surface.

[0084] In this regard, it should be noted that the top half 18' of mold 18, the bottom half 18'' of mold 18, and the other mold 64 are each preferably formed from a thermally conductive and non-magnetic material such as aluminum or an aluminum alloy.

[0085] Resin R is introduced into the other mold 64 during the step of heating the other mold 64 to the first temperature. Resin R is heated below its cure temperature as it is introduced into the other mold 64. A vacuum V can be simultaneously applied via a vacuum pump 74 connected to a vacuum line 78 via a port 76 to enhance the flow of resin R of a flowable consistency.

[0086] The resin R is cured in the other mold 64 to form the device 10. The curing step includes heating the other mold 64 to said second temperature, the second temperature being higher than the first temperature.

[0087] Resin R may be one of a one-component resin R, a two-component resin R including a hardener, and a multi-component resin R including one or more hardeners. Resin R includes an epoxy-based resin, a polyurethane-based resin, a cyanate ester, or another base resin suitable for injection or pouring.

[0088] Thus, in the aforementioned RTM process, at least one roving layer is provided as a first layer of fibrous material 60, and optionally also a second layer or layers of fibrous material 62. The pattern 54 covered with the first layer of fibrous material 60, and optionally with the second layer of fibrous material 62, is then placed in the other mold 64. The other mold 64 is then evacuated to create a vacuum in the other mold 64. The resin R is then injected into the other mold 64 at a temperature higher than room temperature, but possibly lower than the ideal curing temperature of the resin R under pressure. The resin R, which may be pressurized at high temperature, is more fluid than the non-pressurized resin R at room temperature and can therefore flow more easily through the roving and the other mold 64, to ensure that, if possible, no air pockets are formed in the composite material of the final device.

[0089] The resin R can then be solidified, i.e. cured, at a temperature selected below the melting temperature of the wax pattern 54, preferably while gradually increasing the temperature of the mold from lower to higher temperatures (e.g., from 90°C to 100°C) between the boundaries of the second temperature range. If necessary, the cured composite device can be provided with openings and / or apertures. The temperature of the other mold 64 is then gradually increased, for example from 100°C to 120°C, in order to dissolve and remove the wax pattern 54. Dissolving and removing the wax pattern 54 can also be optionally performed outside the mold 64, for example in an oven.

[0090] As known to those skilled in the art of RTM processes, the glass transition temperature of the resin can be temporarily raised in the mold while the temperature is gradually increased in steps above the melting point of the wax to form the device. The liquid wax can then be removed through openings and / or apertures imprinted on the device 10.

[0091] Also, the insert 24' can be removed following removal of the liquid wax to allow for placement of a functional component at the resulting support location. For example, in Figure 16, the insert 24' forms a support for a bearing, and then the bearing 84 is placed in the bearing support 12 that is intrinsically formed within the device 10.

[0092] 9 shows a cross-sectional view similar to that of FIG. 8, with the device 10 having been removed from the other mold 64. The removable material M of the pattern 54 is still present in the device 10.

[0093] FIG. 10 shows a cross-sectional view similar to FIG. 9 in which pattern 54 has been removed from device 10 by application of a heating step that heats removable material M above its melting point by heating another mold 64 to a third temperature.

[0094] Figure 11 shows a cross-sectional view similar to Figure 10, but with insert 24' removed from device 10. The insert on the left in Figure 10 was used to form aperture 80 in housing 16 of device 10. The insert on the right is used to form a support for a bearing, i.e. a bearing race, which can be assembled with the functional part 12 shown on the right in Figure 11. The functional part 12 on the left is an internal seat for a part that can cooperate with a bearing seat.

[0095] Thus, a composite material device 10 includes two functional components 12 located at two predetermined locations along an inner surface 14 of the device 10. The functional components 12 are integrally formed in one piece with said device 10.

[0096] The device 10 can have a pre-determinable wall thickness with a wall thickness tolerance in the range of ±0.5 mm for a wall thickness selected in the range of 1-4 mm, in particular for a length of material of the device 10 cut from the device 10 in a width selected in the range of 0.5-2.5 cm in the range of 1-5 cm.

[0097] FIG. 12 is a cross-sectional view similar to FIG. 10 with a seat 12 for a nut, ie, a part having an internal thread that is essentially present on the inner surface 14 of the device 10.

[0098] FIG. 13 is a cross-sectional view similar to FIG. 10, in which a T-shaped groove is provided as a functional feature 12 essentially present on the inner surface 14 of the device 10.

[0099] Figure 14 shows a cross-sectional view similar to that of figure 10, in which a functional part 12' in the form of a threaded bolt is embedded in the material of the device 10 at the inner surface 14 of the device 10. The threaded bolt is bonded in place by the provision of an insert surrounding said bolt 12', which holds said bolt 12' in place in the pattern and makes it possible to form a permanent bond between the bolt 12' and the device 10 during the step of curing the resin R to form the device 10. In this way, the bolt 12' is embedded in one piece with the device 10.

[0100] Figure 15 shows a cross-sectional view similar to Figure 14, but with sleeve 12' having internal threads that are inherently present on the inner surface 14 of device 10. Like bolt 12' of Figure 14, sleeve 12' is bonded to the device during a step of curing resin R used to form housing 16 of device 10.

[0101] 16 shows a schematic diagram of the internal components of device 10. Device 10 includes a shaft 82 extending along a horizontal axis of said device 10, with ball bearings 84 within device 10 attached to the device at bearing supports 12' formed in one piece with device 10. Shaft 82 is also journalled in device 10 at sleeves 86 and 88. Shaft 82 is connected to electric motor 94 via transmission 92 and drive shaft 90.

[0102] In FIG. 16, since the inserts 12 used for the two parts are fixed to each other when forming the wax pattern 45, the angular tolerance between the sleeve 86 and the ball bearing 84 is less than 0.1°. An angular tolerance of less than 0.05° is achievable with the present teachings. Furthermore, the axial tolerance of the positioning between the inserts 12 of the sleeve 86 and the inserts 12 of the ball bearing 84 is less than 0.1 mm, preferably less than 0.05 mm. Similarly, the positioning tolerance between the inserts 12 of the sleeve 86 and the inserts 12 of the ball bearing 84 is less than 0.05 mm+0.5 mm / m, preferably less than 0.05 mm+0.2 mm / m.

[0103] 17 shows the device 10 as the head of a golf club 96. The head 96 comprises a front face 98 and a body 100. The head can be connected to a shaft (not shown) via a shaft connector 102 in a manner known per se.

[0104] Although not shown in FIG. 17 but shown in FIG. 18, two weights 104, for example formed by tungsten inserts, can be provided as inserts 12' in the wax pattern 54.

[0105] 18, a further insert 12' is embedded within the wax pattern 54. This further insert 12' is a shaft connector insert 106 which allows for a precise connection of the shaft at a predefined angle to the front face and base 108 of the golf club 10'. In this way, the angle between the shaft and the front face of the golf club can be reliably formed with improved alignment quality compared to the prior art. [Explanation of symbols]

[0106] 10, 10' device, golf club 12, 12' Functional part, 12 formed by insert 14. Inside 16 Housing 18, 18', 18'' Pattern template, top half of 18, bottom half of 18 19 Seal 20 cavities 22 Inside 24, 24' 1st type insert, 2nd type insert 26 Slider 28 Magnet 30 Vacuum passage 32 Vacuum Pump 34 Vacuum Port 36 Vertical Axis 38 W container 40 Resin Port 42 Resin Line 44 Gas Supply Section 46 Gas Port 48 Gas Line 50 Seals 52 22 prongs 54, 54' pattern, hollow space 56 54 exterior 58 56 hollow 60 First layer of fibrous material 62 Second layer of textile material 64 Other types 66 R container 68 R Line 70 Heating and cooling devices 72 Coupling 70 to 64 74 More Vacuum Pumps 76 Vacuum Port 78 Vacuum Line 80 Aperture 82 Shaft 84 Ball Bearings 86 Sleeve 88 Sleeve 90 Drive shaft 92 Transmission 94 Electric Motor 96 Golf Club Head 98 Front 100 Body 102 Shaft connector 104 Weight 106 Shaft connector insert 108 Base G Gas H horizontal axis M Removable materials R resin V vacuum W Wax

Claims

1. A composite device (10), said device (10) having an exterior surface and an interior surface (14) and including a plurality of functional components (12, 12') disposed at one or more predetermined locations along said interior surface (14), said functional components (12, 12') being either integrally formed in one piece with said device (10) or embedded within a structure that is integrally formed in one piece with said device (10); The positioning tolerance between the two or more functional parts (12, 12') is less than 0.2 mm; The functional part (12, 12') of the device (10) is selected from the group of members consisting of a tappet with an undercut, an internal seat, a bearing seat, a T-groove, an external thread such as a bolt or stud with an external thread, an internal thread such as a sleeve with an internal thread or a nut, a bayonet connection, an open wedge socket, an eyelet, a ball stud, a dowel and a dowel pin, a hook, a spring element, a bearing block, a bearing block with a clamp, a serrated pin / coupling with or without a bore, a sleeve, an aperture, a support for one or more of the foregoing, and a combination of the foregoing.

2. 2. The device (10) of claim 1, wherein the device (10) has a wall thickness between an outer surface and an inner surface, the wall thickness having a wall thickness tolerance in the range of ±0.5 mm for a material of the device (10) cut from the device (10) at a length in the range of 1-5 cm and at a width in the range of 0.5-2.5 cm for a wall thickness selected in the range of 1-4 mm.

3. The device (10) of claim 1 or claim 2, wherein the device (10) has a wall thickness between an outer surface and an inner surface, and has a wall thickness tolerance in the range of ±0.3 mm for the wall thickness selected in the range of 1 to 4 mm.

4. The device (10) according to any one of claims 1 to 3, wherein the device (10) has a surface profile tolerance of ±0.1 mm.

5. The device (10) according to any one of claims 1 to 4, wherein the device (10) has a surface profile tolerance of ±0.05 mm at the location of the functional components (12, 12').

6. A device (10) described in any one of claims 1 to 5, wherein the angular positioning tolerance between the two functional components (12, 12') in the device (10) is less than 0.3°.

7. A device (10) described in any one of claims 1 to 6, wherein the positioning tolerance between the functional parts (12, 12') is less than 0.1 mm + 1 mm / m.

8. The device (10) according to any one of claims 1 to 7, wherein the device is a head (96) of a golf club (10') and the plurality of functional parts (12, 12') are selected from a weight (104) integrated into the golf club, a shaft connector insert (106) forming a connector to the shaft (10') of the golf club, and a surface serving as a face (98) of the golf club (10').

9. 9. The device of claim 8, wherein one or more functional parts are provided to function as one or more weights (104) of the head, one functional part is provided to function as the shaft connector insert (106), and one functional part is provided to function as a face (98) of the head (96) of the golf club (10').

Images