DE2852033A1 - ROTARY ELEMENT AND PROCESS FOR ITS MANUFACTURING - Google Patents

Description

description

The invention relates to a rotary element for transmission of torques and bending forces, the considerable capable of withstanding axial and torque loads and a method of manufacturing the same.

Conventional rotary elements for the transmission of Kfts, such as For example rotors or drive shafts are generally made of metal, since one of these metal rotors or -driveshafts believes they have great durability own. However, recently there has been considerable interest, particularly the weight of such rotating elements in vehicles, to reduce fuel efficiency with which these elements are driven to increase. Accordingly, from the viewpoint of fuel efficiency a rotor or a drive shaft of light weight turned to considerable interest. One rotor

, or a drive shaft that is not only lighter but also Having a greater axial stiffness would also allow such a shaft to travel at a higher critical speed to drive than this is possible with a shaft made entirely of metal.

Some attempts have been made in the past to develop lighter drive shafts. This is how it is, for example known to reinforce metal pipes by helically folded fibers, which then with a resin, such as for example an epoxy resin are impregnated, whereby a composite structure consists, which has a metal part and a plastic part, which by continuous Fiber windings is reinforced. A composite structure of this type is capable of higher peripheral speeds to withstand, however, there were other disadvantages.

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For example, such helically wound rotors have insufficient axial stiffness for use as Drive shaft.

The invention is accordingly based on the object of a rotary element which is used as a rotor or drive shaft can be to create that is able to transmit large forces despite an extremely low weight and a allows high rotation speed.

It has been found that a composite structure is particularly useful for transmitting the torque and bending loads is suitable in which the axial loads are absorbed essentially by rectified reinforcing fibers will. These reinforcing fibers are embedded in a resin. The primary torque is absorbed by a metal tube. The metal and the fibers form a composite structure in which the fibers in a predetermined Angles are aligned so as to make the essential differences in the physical properties of the fiber-reinforced Resin and the physical properties of the metal pipe, such as the difference in the thermal expansion coefficient of the metal pipe and the thermal expansion coefficient of the fibers of the fiber-reinforced Resin. Thus, a metal tube core is proposed, which preferably consists of aluminum, on the surface of which a metal adhesive layer is first applied. Above Alternating layers of resin-impregnated, rectified fibers are applied to the adhesive layer preferably made of carbon or graphite and woven glass fibers, with a layer of woven glass fibers begins. This layer is followed by another made of resin-impregnated, continuous, rectified reinforcing fibers, where one continues the alternating structure

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sets, but ends with a layer of resin-impregnated, continuous unidirectional reinforcing fibers. Each subsequent layer of resin impregnated, continuous unidirectional reinforcing fibers is oriented so that the fibers make an angle of between about 5 ° to about 20 ° to the Form the longitudinal axis of the metal pipe, while the corresponding next layer is oriented in opposite directions. One such Pipe is preferably made by placing substantially rectangular layers of fiber-reinforced around the metal core Materials, creating a substantially cylindrical wave that has a uniform thickness of the fiber reinforced resin layer on the surface of the core wearing.

It was found that the fiber reinforced layer is a composite tubular shaft does not have to have a uniform thickness over the entire length of the shaft to achieve the required must have mechanical properties with regard to the transmission of torsional and bending forces. Much more is essentially the greatest strength of fiber reinforced resin required in the middle part of the tubular structure, while less reinforcing material on the exterior Must be at the end.

Accordingly, it becomes generally a in accordance with the invention tubular structure for a torsion element described, by means of which torsional and bending loads are transmitted let, being around a metal core, which is preferably made of If there is aluminum, a layer of metal adhesive is first placed. One applies alternately to the metal adhesive Layers of resin-impregnated, rectified reinforcing fibers, especially carbon or graphite and woven fiberglass starting with a layer of woven fiberglass, the one layer made of resin

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Impregnated, unidirectional reinforcing fibers follows, whereupon the application of the layers is continued alternately, but ends with a layer of resin-impregnated, continuous unidirectional reinforcement fibers. Each of the successive layers of the with
Resin-impregnated, continuous rectified fibers have a fiber orientation at an angle of about 5 ° to 20 with respect to the longitudinal axis of the metal pipe, the next layer with respect to the previous one with its fibers on the opposite side ori- is entertained. The fibers in the woven fiberglass layer are each aligned at 0 ° or with respect to the longitudinal axis of the tubular metal core. However, it is important that the number of
Layers over the length of the tubular core changes, so that the wall thickness over the length of the tubular metal shaft is thickest essentially in the central region of the shaft.

Further features, advantages and details of the invention
are based on the following description of various exemplary embodiments with reference to the attached
Drawings clearly. It shows in detail:

1 shows a partially cut-open, perspective illustration of the assignment of the alternately applied layers to the metal core _f

Fig. 2 is a plan view of a preferred geometric embodiment of the one used according to the invention Layers,

3 shows a top view of another geometric embodiment of the one used according to the invention Layers,

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FIG. 4 shows a further plan view of another geometric shape of the layers which, according to FIG Invention find use,

FIG. 5 is a vertical section through the preferred layering along section line 5-5 of FIG Fig. 2 and

Fig. 6 is a perspective view of the tubular shaft according to the invention, partially is cut open to show the Fibers in the reinforcement layers.

The drive shaft described according to the invention has a metal core 25 in the form of a cylindrical, hollow Tube, as shown in FIG. So that the drive shaft has the required weight and the desired Having strength, the metal core is preferably made of aluminum or magnesium alloy. Preferred the following aluminum alloys are used for the manufacture of the core 25: 2024, 7075, 7078 and 6061, where these specifications are American alloy compositions acts. In particular, these alloys preferably have a T-6 hardening. Aluminum alloy Alloys with the aforementioned compositions and the aforementioned hardness are commercially available and can are formed into tubes by conventional methods, which are formed by drawing or extruding thick-walled, cylindrical Elements to be shaped according to the required dimensions.

In making the composite tubular element of the invention, it is of great importance that the Metal core 25 is completely clean. To avoid any possible upper

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The final cleaning is to avoid surface pollution of the metal core 25 with a material such as alcohol or chlorofluorocarbon carried out to remove traces of oil, fat etc. to remove.

The metal core 25 is according to the invention with a coating of resin-impregnated, continuous rectified Reinforcing fibers and woven glass fibers surround that with are connected to the core 25, so that a substantially integrally formed element is formed. This layer made of fiber material impregnated with resin consists of individual layers of these materials. However, it is particularly preferred that the two layers of fiber reinforced resin material are finally bonded together by allowing the resin contained therein to harden.

When making the composite structure of the tubular Element is first put together a number of layers that have essentially the same shape. Thus, a layer such as layer 26 is made up of a surface of a rectified continuous fiber-reinforced material that is impregnated with a synthetic resin. Preferably the Fibers in this fiber-reinforced sheet material made of carbon or graphite, and for the sake of simplicity these are Fibers hereinafter referred to as graphite fibers. Like fig. show, the layer 26 has a predetermined pattern, the length of which is preferably slightly longer than the axial length of the fiber reinforced layer in the final composite tubular element. The reason for this oversize is one Ease of manufacture, which will become clear in the course of the following description. As can be seen from the 1 and 2, is the preferred geometric shape

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for the generally provided with the reference numeral 10 Layers are essentially triangular, with End tabs 30 and 32 are provided which extend outwardly from the base of the triangle. The width of the end flaps 30 and 32 is about twice as large as the circumference of the tubular core 25, so that the sheet material can be wrapped around the core 25 essentially twice. The width of the impregnated sheet material, measured from the top of the triangle to the base line should be sufficient so that the layer is several times around the perimeter of the metal core 25 can be placed. Preferably the width of the impregnated fiber material is about that Six times the circumference of the metal tube 25.

As FIGS. 3 and 4 show, other patterns can also be used in the manufacture of the layers and finally of the composite Find rotor use. So each layer can be cut out in the desired pattern or pattern by putting different geometric shapes together combined. Thus, the pattern 10 according to FIG. 2 was created by combining rectangular and triangular shapes, the are alternately cut out and arranged. The shift pattern 11 according to FIG. 3 is obtained by making several rectangles each subsequent shape is a little shorter than the preceding rectangle. One obtains, for example the layer pattern 12 of FIG. 4 by combining a trapezoid and a rectangle with one another.

In the Hazrmaterial with which the graphite fibers 22 of Layer 26 are impregnated, it is a thermosetting resin. Basically the resin of all is resin impregnated Thermosetting layers. Suitable resins which harden in heat are, for example, epoxy and polyester resins.

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The epoxy resins or polyepoxides, which are Well known condensation products are compositions containing oxirane rings with compounds containing hydroxyl groups or active hydrogen atoms such as amines and aldehydes. The usual epoxy resin compounds are those of epichlorohydrin and bisphenol and their homologues.

The polyester resin is a condensation product of polybasic acids with polyhydric alcohols. Typical polyester include polyterephthalates such as polyethylene terephthalate.

It is well known in the art that these thermosetting resins contain additives such as hardeners and may contain something similar. The preferred modified epoxy resin impregnated graphite fibers are commercially available. For example, the epoxy pre-impregnated graphite fibers are called Rigidite 5209 and Rigidite 5213 manufactured by the Narmco Division of Celanese Corporation, New York, V. St. A., sold. Other sources of supply for the resin prepreg graphite fibers are known in the industry.

Generally, the resin impregnated sheet material 26 has a thickness of about 0.178 mm to about 0.254 mm and contains from about 50% by volume to about 60% by volume graphite fibers in the thermosetting resin. The layer material used according to the invention preferably contains 26 54% by volume to 58% by volume continuous unidirectional graphite fibers in the epoxy resin. The graphite fibers preferably have Young's vision

6 6

Young's modulus in the range from 2.11 10 to 3.52 χ 10 kg / cm

2 and a strength in the range of about 14 085 kg / cm to

about 20 169 kg / cm ² .

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As shown in the drawings, layers 24 and 27 of woven glass are also provided. These layers 24 and 27 made of woven fiberglass have the same dimensions and geometric patterns as the resin-impregnated, fiber-reinforced Layer 26. The layers of woven fiberglass 24 and 26 are about 0.0254 to about 0.0508 mm thick and are made of woven glass fibers, which is a cloth-like fabric known as fiberglass gauze. A particularly preferred fiberglass gauze is Style 107, marketed from Burlington Glass Fabrics Company, New York, V. St. A. The fibers 21 of the fabric are, as can be seen, aligned at an angle of 0 and 90 ° with respect to the longitudinal axis of the layer material 24 and 27.

As can be seen from the detail in Fig. 1, the rectified Graphite fibers 20 in the layer 28 at a specific predetermined angle Ql with respect to the longitudinal axis of layer 28 aligned. The next layer of resin impregnated rectified continuous graphite fibers, namely in the layer 26, the rectified graphite fibers are 22 is oriented at a negative predetermined angle θ 2 with respect to the longitudinal axis of the layer 26. Such a Angle preferably has the same dimension and of course an opposite sign with regard to the orientation of the fibers in the first layer 28.

As the composite shaft is made, a plurality of layers become more resin impregnated, more continuous Graphite fibers made from woven fiberglass made from a layered material cut out in the desired flat shape. Each layer is the same size and shape. As already mentioned, the end flaps 30 and 32 have a sufficient width so that they are at least twice

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can be constantly knocked around the tubular metal core 25. As already mentioned, lies the major axis substantially along the length of the shaft, the major axis preferably being slightly longer than the length of the assembled tubular element.

The different layers of the layer material are arranged alternately, for example with a lower one A layer of resin-impregnated graphite fibers begins, followed by a layer of fiberglass, followed by another layer resin-impregnated graphite fibers is applied, which is followed by a further glass fiber layer. In Fig. 1 For example, the glass layers 24 and 27 alternate with the graphite fiber layers 26 and 28.

For each subsequent layer of resin-impregnated, unidirectional reinforcing fibers, however, it should be ensured that the reinforcing fibers are oriented at a predetermined orientation angle with respect to the longitudinal axis of this layer. In general, this orientation angle is between about 5 · ^r and about 20 °, preferably this orientation angle is about 10 °. According to a particularly preferred embodiment, the orientation angles for the graphite fibers are the same for each subsequent layer of the resin-impregnated graphite layer material, but with the opposite sign for each subsequent layer. Thus, with respect to Figure 1, the fibers 20 in the layer 28 are arranged at an angle of θ 1 and the fibers 22 of the layer 26 are arranged at an angle θ 2 relative to the length of the layer. As mentioned, it is particularly preferred that the size of Q 1 and θ be the same, with θ 1 and θ 2 merely having an opposite sign, so that the fibers cross one another.

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When arranging the individual layers to produce the Layer envelope, it is particularly expedient to have a woven layer on a layer consisting of resin-impregnated graphite fibers Apply fiberglass layer. Then on this layer the next resin-impregnated graphite fiber layer is applied.

As can be seen from FIGS. 1 to 5, there is the first layer made of a layer of resin-impregnated graphite fiber material 26, to which a fiber glass layer 27 is applied. Next is a layer of resin impregnated sheet material 28 applied, on which a fiber glass layer 24 rests.

As can be seen from FIGS. 1, 2 and 5, these embodiments include a rectangular layer 19. This layer 19 is a metal adhesive. The width the rectangular layer 19 is sufficiently around the core 25 easy to enclose. It is particularly important according to the invention that a metal adhesive layer is used which Resin of the resin-impregnated sheet material to the tubular core 25 binds. The metal adhesive material according to the invention is used is one that is normally used for bonding plastics to metals, such as an elastomeric, modified epoxy resin and an elastomeric, modified phenolic urea resin. An example of such an adhesive is a modified polysulfide elastomer Epichlorohydrin bisphenol resin. Many of these adhesives are commercially available, with one being called Meiallbond 1133 is known, which is an elastomeric, modified epoxy material available from Narmco Division of Celanese Corporation, New York, V. St. A., is sold. Another glue is FM123-2 made by the company American Cyanamid, Wayne, V. St. Α. Of the Metal glue can be applied to the top of the fiberglass sheet material be applied when the physical co-existence of the

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Glue allows this. It can also be brushed or sprayed onto the circumference of the metal core 25, for example will. According to a preferred embodiment of the invention, the adhesive is made in the form of a thin film Layer material, such as. B. the layer material 19, in the Fig. 1, 2 and 5 applied.

It has also been found that it is particularly advantageous to use a solution of the same adhesive as he is present in the layer 19 to be brushed or sprayed onto the exterior of the metal core 25 after the metal core has been cleaned accordingly.

In general, the weight of the metal adhesive layer used in accordance with the invention is in the range from about 0.0089 to

2
about 0.0196 g / cm, with it being particularly preferred that the

2 weight of adhesive layer 19 maintained at about 0.0146 g / cm will. With the amount of glue to be used, it is important to ensure that it is not just an appropriate one Bond occurs between the synthetic resin and the metal core, but that there is also sufficient torsional rigidity of the Metal pipe is achieved with the longitudinal stiffness of the graphite fiber reinforcement.

In each case, a polygonal layer of layer material, consisting of the adhesive layer 19, resin-impregnated graphite fibers and a glass fabric, is placed around the circumference of the metal core 25. It should be understood that the adhesive will of course be brought into contact with the tubular metal core 25, and that the continuous, unidirectional graphite fiber at an angle between - are oriented 20 ° with respect to the longitudinal axis of the metal core, while the woven fiber glass layers - 5 ° to are aligned so that the angle at 0 bz ·. 90 in

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with reference to "the longitudinal axis of the metal core 25. After the Metal core with the. required layers is encased, these materials can be removed with the help of a Zellofan tape, for example, be held. On the other hand, the arrangement of the core and the outer resin-impregnated graphite fiber layers held by applying a heat-shrinkable polyethylene film (not shown), which acts as a form and is removed in the manner still to be described below.

After wrapping the core material in the required number of layers, the assembly is placed in an oven and heated to a temperature sufficient to achieve a Bonding of the individual layers to one another, as well as of the various layers to one another, to accomplish. The temperature, to which the assembly is heated depends on a number of factors, including the type of one used Resin that is used to impregnate the graphite fibers. These temperatures are well known. For a modified epoxy resin with which the graphite fibers are impregnated the temperature is in the range of about 100 ° C to about 180 ° C, and preferably about 140 ° C.

If a polypropylene wrapping film is applied to the outside to hold the various layers around the core, it can can be easily peeled off the surface of the shaft by hand. Surface irregularities, if any should be on the shaft can be removed by smacking or grinding and similar operations. If so desired the shaft can be provided with a color coating.

Given that it is not always possible to have a To achieve a completely flat end in the assembled pipe material, it is preferred, as already stated, in

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generally to use a layer material that is slightly longer than the final length of the pipe element to be produced. In this way, a rounded shoulder, such as shoulder 6 in FIG. 6, can be avoided by Make a radial cut through the tube behind the shoulder, making a completely straight end edge achieved if this is desired for the assembled pipe element.

The invention has been described in relation to composite shafts which are essentially torsional and bending loads are excluded, regardless of the area in which such shafts are used.

In order to further explain the invention, a typical composite drive shaft for a truck will be described below. For such an application, the metal core 25 typically has a length of 1.22 m to 3.05 m _{· t,} an inside diameter in the range of 5.08 to 11.43 cm, and an outside diameter in the range of 5.08 to 12.7 cm. The shaft carries a layer of a metal adhesive in the area

from about 0.0098 to 0.0195 g / cm. On top of the metal adhesive layer are two layers of a fiberglass gauze and the epoxy resin impregnated, rectified, continuous graphite fiber sheet material applied, each layer consisting of a layer of the gauze and a layer of the fiberglass layer material. The orientation of the fiberglass layer is at 0 ° and 90 ° with respect to the longitudinal axis of the shaft, and the orientation of the continuous graphite fibers is about 10 ° to this. Each of the subsequent layers of graphite fibers is also at 10 °, but in the opposite direction to the next preceding one Layer. The graphite fibers are thus oriented at an angle of -10 ° with respect to the longitudinal axis.

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As can be seen from Fig. 6, has such a drive shaft a first end part 42 and a second end part 43 and two intermediate areas 44 and 45, respectively. Finally, there is one more substantially central part 46 is present. The fiber-reinforced covering in the area of the first and second end parts 42 and 43 consist of two layers around the core 25. However, the number of layers changes over the length of the shaft in the Way that the cladding thickness is thickest substantially in the central region of the shaft. With the truck drive shaft described the height of the essentially triangular pattern for the production of the layer material is chosen so that essentially six or seven layers are laid around the central portion 46 of the tubular shaft, wherein the layers in the intermediate regions 44 and 45 decrease over the length of the shaft.

In contrast, a standard composite automobile driveshaft would according to the invention have an aluminum core, with a length between about 102 cm to 183 cm, a Outside diameter between 6.35 cm and 7.62 cm as well as one Inside diameter between 5.72 cm and 6.99 cm. Such a compound For example, drive shaft would have about two layers of woven fiberglass and continuous Graphite fibers impregnated with an epoxy resin carry, each envelope consisting of a layer of fiberglass and a layer of resin impregnated fibers. As in the drive shaft of the truck, the graphite fibers are in an angle of i 10 ° with respect to the longitudinal axis of the shaft aligned while the optical fibers are at an angle of 0 ° and 90 ° with respect to the longitudinal axis of the shaft. In addition, there is a -between the metal core and the reinforcement layer Layer of metal glue provided.

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As noted, one difficulty lies in the manufacture of composite tubular members for transmission of axial forces and torsional loads in that there is a big difference in physical properties the metal core and the fiber-reinforced layer material consists, wherein the layer material tends to the other ■ to counteract. Different components of this compound Structure are based on the appropriate alignment of the graphite fiber glass in the reinforcement material and in the layer of metal adhesive between the metal core and the continuous graphite fiber layer. The decrease of the Weight without sacrificing any loss of strength is achieved by adding the maximum fiber reinforcement to one Point provides where the loads are greatest. Thus, the gradual increase in fiber reinforcement is of one End to center and the decrease to the second end of the pipe is of the utmost importance.

The dimensions and dimensions can easily be adapted to the respective area of application.

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Claims (8)

PATENTA N WALTE DR. KARL TH. HEGEL DIPL.-ING. KLAUS DICKEL GROSSE BERGSTRASSE 223 2000 HAMBURG 50 JULIUS-KREIS-STRASSE 33 JOOO MONKS. 60 PO Box 500662 TELEPHONE (040) 39 6295 TELEPHONE (089) 885210 Γ Π Telegram address: Deollnerpatenl Munich L J Your reference: Our reference: 8000 Munich, den H 2901 ßxxon Research And Engineering Company PO Box 55
Linden, NJ 07036
V. St. A. Rotary element and process for its manufacture Expectations: Λ - iy rotary element for the transmission of torques and Bending forces, characterized by a tubular metal core (25) §09823 / 0770 Postal checking account: Hamburg 291220-205 Bank: Dresdner Bank AG. Hamburg, account no. 3813897 ORIGINAL INSPECTS one around the outer surface ¹ :. : the metal core (25) laid metal adhesive layer (19), a plurality of superimposed layers of resin impregnated, unidirectional fibers (20) laid around the circumference of the tubular metal core (25), the resin impregnated fibers (20, 22) of each layer at an angle of between about 5 ° to 20 ^; are aligned with respect to the longitudinal axis of the metal core (25) opposite to the orientation of the closest layer of resin-impregnated fibers, a layer (27) of woven glass fibers (21) in each case between layers (26, 28) lying one on top of the other Resin impregnated fibers (20, 22), a layer (24) of woven glass fibers between the metal adhesive layer (19) and the overlying layer (28) of resin-impregnated fibers (20), each of the overlying layers (26, 28) of resin impregnated, unidirectional continuous fibers (20, 22) and the layer (24, 27) of woven glass fibers (21) have such a shape that when the tubular Metal core (25), the thickness of which changes over the length, the maximum thickness essentially in the middle area of the element, while the minimum thickness is at both ends of the element. 2. Rotary element according to claim 1, characterized in that the resin is a thermosetting resin. 3. Rotary element according to claims 1 or 2, characterized in that that the reinforcing fibers (20, 22) made of carbon 0098? 3/077 Π ^ 852033 made of fabric or graphite, the fibers with respect to the longitudinal axis of the tubular metal core (25) in one Angle of about 10 ° are aligned. 4. Rotary element according to one of the preceding claims, characterized in that the woven glass fibers (21) are aligned such that they form an angle of 0 or 90 ° with the longitudinal axis of the tubular metal core (25) form. 5. Rotary element according to one of the preceding claims, characterized in that the tubular metal core (25) consists of an aluminum alloy. 6. Rotary element according to one of the preceding claims, characterized in that the adhesive layer (19) has a 2 2 Thickness from about 0.0098 g / cm to about 0.0196 g / cm. 7. Rotary element according to one of the preceding claims, characterized in that it is a drive shaft for a truck. 8. A method for producing the rotary element according to any one of claims 1 to 7, characterized in that alternating layers of fiberglass fabrics and resin layers reinforced with fibers are laid around a tubular metal core, the unidirectional fibers of carbon and / or graphite, the glass fibers of the fabric with the longitudinal axis of the metal core form an angle of 0 ° or 90 °, while the unidirectional reinforcing fibers approximately at an angle of - to about 5 ° - are oriented 20 ° to the longitudinal axis of the tubular core, and that the thickness of the fiber- reinforced resin layer over the length of the metal core so that it is from one end of the pipe 909 8 23/0 7 1 Π 2 ^ 52033 shaped metal core gradually increases to the middle and from there gradually to the second end of the metal core decreases again. 909823/0770