Middle part for a bow

Abstract

The invention relates to a center section for a bow with receptacles for two limbs, wherein the center section has a tiller screw with a spring system. According to the invention, the middle part has a limb receptacle in which the tiller screw for holding the end of the limb and a receptacle for a hemisphere of a limb are arranged, by whose interaction with a limb a counterforce to the limb movement when drawing the bow can be built up. This creates a central part as described above, which can be assembled without tools and facilitates the handling of the bow.

Description

[0001] The invention relates to a center section for a bow with two limb pockets for two limbs, wherein the center section has a tiller screw with a spring system.

[0002] Archery, especially outdoors, is enjoying ever-increasing popularity. A wide variety of bows are used. One well-known type is the three-piece bow, which consists of a riser and two limbs attached to the riser via various connection systems.

[0003] With few exceptions, such as the Japanese Yumi, the grip of a bow is located at its geometric center. The arrow rests above this center, and the string is consequently drawn—depending on the grip technique used—more or less far above its center. This results in the upper limb bending back further than the lower limb—logically, to a greater extent the higher the string is gripped. With the same draw weight and angle of attack, this would result in an extremely uneven movement of the limbs. The limbs would neither reach their endpoints simultaneously nor exert a uniform force on the arrow. The tiller is the difference in distance between the upper and lower limbs and the string, or rather, the ratio of their forces. Adjusting the tiller is a fine-tuning method for bows whose limb pockets allow for this adjustment.The tiller is a factor that must be considered in the production of bows. On bows with a suitable limb attachment, this angle can be fine-tuned by the archer using a tiller screw.

[0004] Apart from a few special connection systems, which make up only a very small percentage of the market, there are two systems that are mainly used in three-piece bows: Firstly, a mechanical connection between the riser and the limbs, which is primarily used in bows with wooden risers (partly also in metal risers, but to a very limited extent), and secondly, the so-called ILF system (international limb fitting system), which has become the standard for metal risers and is now also widely used in wooden risers.

[0005] Although both connection systems (connection types) utilize mechanical components, for the purposes of this application, a mechanical connection is defined as a rigid fastening in which the limb cannot move relative to the riser and the limb's alignment is not adjustable. Such a mechanical connection is typically achieved via a screw connection, whereby small threaded inserts are installed in the riser, and the limbs are then rigidly screwed to the riser using screws that are screwed into these inserts, thus creating a fixed connection.To ensure the correct orientation of the limbs in relation to the riser, even if only one screw is used to attach a limb, alignment pins are used, which are also provided in the riser of the bow and engage in corresponding counter-shaped recesses in the limbs.

[0006] Unlike this mechanical connection, the ILF system uses a plug-in connection. With this system, the limbs are attached to the riser with slight movement when the bow is unstrung. Only when the bow is drawn does a stable system emerge. Unlike screw-in limbs, no screws need to be tightened to secure the limbs; instead, the limbs are simply inserted into the slots. The system consists of a pivot pocket on the riser and a tiller screw. To mount the limb, a corresponding counterpart attached to the limb is inserted into the pivot pocket until it reaches a defined end position. Using only the pivot pocket would allow the limb to rotate relative to the riser. Therefore, a tiller screw is threaded into the riser.The end of the limb features a groove, giving it a dovetail-like shape. When the limb is fully inserted into the pivot slot, its dovetail end slides past the tiller screw on both sides, engaging the screw in the groove. This prevents the limb from rotating around its attachment point in the pivot pocket. The advantages of this system include quick and easy assembly and disassembly of the limbs, as well as the numerous adjustment options available. The tiller screw allows for adjusting the bow's draw weight, while the limb's orientation can often be adjusted via lateral adjustments on the pivot slot. The ILF system has become a standard in archery, and for further explanation, please refer to the relevant literature.The ILF system consists of standardized attachments for the upper and lower limbs on the bow's riser, compatible with all ILF limbs. This system is simple to manufacture but difficult for the archer to handle.

[0007] From EP 4 141 375 A1, a connection device is known which is configured to enable the attachment of limbs of different connection types to a bow riser and which has at least one receiving section which is designed to receive various elements, wherein the elements are configured to adapt the geometric shape of the connection device to the corresponding geometry of the connection type of the limb to be attached and can be inserted into and removed from the receiving sections.

[0008] German patent DE 44 32 500 A1 describes a dynamic limb mounting with point-like, variable support and splash protection for sporting bows, designed to dampen vibrations at the transition from the limb to the riser. Simultaneously, the limb mounting is designed to be floating in order to reduce torsional stresses when drawing the bow and thereby achieve better shooting performance, i.e., improved grouping.

[0009] The variable mounting system allows the archer to tune the bow (compound bow) to increase efficiency or improve shooting characteristics. Crucial to achieving these advantages is the combination of point mounting and support via a disc spring assembly, which is installed in a splash-proof manner.

[0010] The object of the present invention is to create a central part according to the preamble which can be mounted without tools and facilitates the handling of the bow.

[0011] This problem is solved according to the invention by arranging in the limb pocket the tiller screw for holding the end of the limb and a receptacle for the ball head of a limb, the interaction of which with a limb can build up a counterforce to the limb movement when drawing the bow.

[0012] Regardless of the spring system, the tiller can be locked without tension using the tiller screw. When the bow is drawn, tension is applied to the limb, causing the tiller screw to lift against the force of the spring system, thus creating a counterforce to the limb movement. A kind of rocker mechanism ensures that any lateral forces on the limbs are completely compensated for in case of release errors. Furthermore, the residual energy after the shot is completely dissipated and absorbed away from the archer and the riser by means of a decoupled swing-out. This prevents breakage and delamination, resulting in a significant improvement in safety. The limb itself no longer touches the receivers, which improves flexibility and also enhances the surface durability of the limbs.Self-centering of the limbs is achieved, minimizing release errors because the limbs can move freely, unaffected by lateral forces caused by release errors, and can counteract the string's oscillation through controlled force from the spring. The spring can be implemented in various ways, such as using disc springs or coil springs, a magnetic spring, a pneumatic spring, or a hydraulic spring. Bounce effects can also be minimized during the so-called "tapping" process.

[0013] A further development of the invention consists in the fact that the receptacle for the ball head of a throwing arm is designed as a spherical cap or as a cone.

[0014] It is possible to use either limbs that are already equipped with a ball head or to equip existing limbs with a ball head adapter.

[0015] To achieve full support for the resolution of lateral forces, a ball-head adapter is screwed onto conventional ILF limb screws. The ball head of the adapter is inserted into a spherical cap or cone, where it can move freely. In this way, all commercially available ILF limbs can be easily converted.

[0016] A further development of the invention consists in the fact that the receptacle for the ball head of a throwing arm comprises a preferably tool-free locking system for positive locking of the throwing arm.

[0017] In a tool-free design of such a locking system, two movable arms of the locking system, traveling around a common axis, engage the dovetail screw above the hemisphere and thus fix the hemisphere in the receptacle. As an alternative to this positive locking mechanism, the throwing arm can also be fixed magnetically or by friction.

[0018] The locking system can be reopened by spring pressure, magnetic pressure, or finger pressure, causing the locking arms to open and releasing the dovetail screw. A return spring then returns the locking arms to their starting position.

[0019] In one embodiment of the invention, the tiller screw is designed as a hollow tiller screw body, which has an external thread for screwing into a receiving bolt with centering cone and an internal screw channel for screwing in a fixing grub screw as well as a tiller screw head, wherein the tiller screw head has a screw cap with scale.

[0020] With this design of the tiller screw, the tiller can be locked into the receiving bolt with centering cone without tension. Initially, the bolt rests flat against the upper breechblock due to the spring's preload until the limb is drawn. The receiving bolt, freely mounted and protected from wear by a bearing, then lifts out of the breechblock. As this happens, the spring system is increasingly charged with energy, creating a counterforce to the limb's movement.

[0021] An alternative embodiment of the invention consists in a roller body having a thread into which the tiller screw can be screwed, wherein the end of the tiller screw opposite the tiller screw head engages in an opening of a pin knob acted upon by a compression spring, which is arranged slidingly in an opening of the roller body perpendicular to the direction of the thread, wherein a indexing mechanism with a ball detent is arranged on the pin knob.

[0022] During this training, the tiller screw can be adjusted without tools using spring pressure and a ball detent mechanism with measurable clicks. One click of the ball detent corresponds to an actual stroke of, for example, 0.1 mm, enabling extremely precise adjustment of the limbs relative to each other in the tiller. This allows basic settings to be recorded and, after further testing, reproducibly documented and readjusted. The tiller screw itself should have variable thickness adjustment at the mounting point below the adjustment knob to compensate for tolerances in the limb's slot and thus completely eliminate lateral variation during release.In the lower part of the tiller screw, which protrudes laterally from the roller body, a color scale, similar to a traffic light system, can be used, in which "green" stands for "safe", "yellow" for "moderate use" and "red" for "caution - risk of injury".

[0023] Counting the clicks and using a color scale ensures double-checking of the safety and reproducibility of the adjustment. The tiller screw is adjusted and locked using a button located on the side of the roller body. Pressing the button releases the tiller screw, and pressing it again locks it. This eliminates the possibility of a lock screw loosening, unlike conventional ILF tiller screws, thus preventing tolerances and adjustments during shooting. It also significantly improves ease of use, as no tools are required to adjust the tiller. The roller body, mounted horizontally in the limb pocket, conforms fully to the limb angle. This means the limb rests completely under the tiller screw head, which is not the case with conventional risers.This ensures better energy transfer and smoother limb oscillation. The resulting release is smoother, more accurate, and more repeatable. While the dovetail socket of the ILF screw is adjustable without tools, thanks to a knurled screw and a control wheel beneath the socket, no tools are required to adjust the entire bow. The zero-play adjustability and fine-tuning create a limb socket without tolerances, which dramatically improves shooting accuracy.

[0024] A further development of the invention consists in the fact that the throwing arm receptacle can be connected to the middle part without tools.

[0025] This simplifies the assembly and replacement of the limb holder, as both can be done without tools.

[0026] In this context, it is advantageous that the limb receptacle can be positively connected to the middle section, wherein a guide, preferably a dovetail guide, is provided in the middle section, into which a sliding element of the limb receptacle with a corresponding shape can be inserted, and wherein in the end position a preferably spring-operated or magnetically operated locking element is provided between the limb receptacle and the middle section.

[0027] The locking element can be manually reopened.

[0028] A preferred embodiment of the invention consists in the middle part being made of fiber-reinforced composite materials, wherein the fiber-reinforced composite materials are selected from the group consisting of • Plastics, especially aramids and acrylates, • Fiber-reinforced plastics, in particular glass fiber reinforced plastic (GFRP) and carbon fiber reinforced plastic (CFRP), • crystalline or amorphous metals, especially aluminium, magnesium and steel, • organic natural materials, especially wood or bamboo, • mineral natural substances, especially basalt and gneiss.

[0029] The middle section can be manufactured from these materials using a composite process.

[0030] Furthermore, it is advantageous that the body of the middle part is designed as a grid or honeycomb structure, with a transverse reinforcing plane preferably provided at the outer edges.

[0031] Similar to a steel H-beam, the central section preferably has a transverse reinforcing layer at its outer edges, preferably running at an angle of approximately 9° to the central layer. This transverse reinforcing layer preferably consists of high-strength aluminum or amorphous metals or metal alloys, each preferably encased in carbon prepreg or basalt prepreg. These material combinations combine good vibration damping with high strength. Surface treatment of the metal layer is unnecessary, as the prepregs adhere better to the rough cast or milled metal surface.

[0032] This creates a stable base body that follows the contours of the longitudinal axis with intact fibers. All important fittings, bushings, and fasteners are attached in this transversely reinforcing plane and stiffened with additional webs using a measurement and development method preferably based on finite elements, in order to counteract all force influences in the form of vibrations, deformations, etc., by following the lines of force.

[0033] Non-load-bearing materials are then inserted into the resulting honeycomb structure. These materials can be of any design, as they do not contribute to stability. For example, imperfect but beautiful wood or brittle materials like stones, which were previously avoided due to the risk of injury, can be used.

[0034] These materials can be inserted into the space between the struts using an adhesive, ideally forming a joint with damping properties between the respective material and the struts of the honeycomb structure. Preferably, the joint also exhibits a different thermal expansion behavior than the other elements of the central section. This ensures that the parts cannot shear off each other in the event of temperature fluctuations.

[0035] In a further development of the invention, it is provided that the middle part has a handle shell which is individually shaped using artificial intelligence after a 3D scan of the user's hand and based on experience.

[0036] The middle section has a grip recess by which the bow is held. Preferably, according to the invention, the grip recess is individually adapted to the user's anatomy, preferably using artificial intelligence. In this process, a 3D scan of the user's hand is preferably created, and then, based on experience with previously created grip recesses for users with a similar hand shape or size, an individually shaped grip recess is produced.

[0037] The handle scales are preferably made from stabilized wood. Stabilized wood is oven-dried, resin-free wood that is filled and compacted with acrylate, thanks to the wood's capillary action. This creates a natural fiber composite material without hygroscopic properties, exhibiting increased hardness and elasticity, and being both waterproof and robust.

[0038] The surface treatment of the risers, including the grips, and limbs is preferably carried out by coating them with a polyurethane with clear properties, ideally with the product Puroclear® (RÜHL PUROMER GmbH, Hugenottenstraße 105, D-61381 Friedrichsdorf). This is sprayed onto the limbs, riser, and grips using a vacuum injection process in metal molds, resulting in faster demolding and painting times compared to conventional painting methods. In addition to increased cost-effectiveness, this also creates a surface with self-healing properties. In the event of impact or scratches, Puroclear® is able to restore its original surface within 24 hours at room temperature.

[0039] Another problem in archery is achieving perfect clearance, i.e., that an arrow does not touch the bow after leaving the string and has the most perfect trajectory possible.

[0040] To achieve this, an arrow rest and an arrow support were developed within the scope of the invention, each of which can be used both together with the inventive middle part, but also independently with other middle parts.

[0041] This arrow rest comprises a lifting plate that can be pushed upwards via a release mechanism and returned to its starting position by a return spring. A support cylinder, rotatable around its axis by a magnetic mechanism, is mounted in the plane of the lifting plate. A support wire is attached to this cylinder. By rotating the support cylinder, the support wire can be lowered onto the resting board or raised to protrude from it. In this raised position, the arrow rest is activated. When the shot is released, the support wire folds into the resting area, i.e., into the plane of the lifting plate, after supporting the arrow. A locking screw on the magnetic mechanism allows adjustment of its preload.A locking screw allows adjustment of the support wire's alignment and resistance, which is necessary, for example, for heavier arrows. A setscrew inside the support cylinder allows adjustment of the support wire's height and alignment with the arrow's central axis.

[0042] The arrow rest can be operated with one finger, readjusted during the shot, and fine-tuned using a tool. Handling is therefore very simple, and tuning is easy. The arrow rest can be made of stainless steel, aluminum, or amorphous metals or metal alloys based on zirconium or titanium, which offer exceptional springiness and a non-magnetic base, making the mechanism resistant to fatigue fractures or similar material failures.

[0043] The described arrow rest is arranged in a rest body, which can be connected to a central section. If the described arrow rest is not to be used, a replacement rest body can be inserted into the central section, allowing the use of a conventional arrow rest. The rest body preferably has a hole on the side facing the central section, which allows water to drain away if it penetrates due to weather conditions.

[0044] The arrow rest, also called a button, serves to compensate for irregular arrow oscillation, enabling the arrow to pass the center line, the so-called centershot, during its forward movement through the bow. Like conventional buttons, the button according to the present invention also serves to cushion the arrow's oscillation. However, in the button according to the invention, a preload screw, an eccentric lever, and a rotary cylinder are used to retract the button pin, thus eliminating any protruding part of the rest in the shooting window that the arrow could collide with during an incorrect release technique.

[0045] The centershot position of the button pin can be locked by an adjustment mechanism. At its maximum extension, this mechanism should accommodate the smallest micro-diameter of an arrow in the centering position. Larger diameter arrows are screwed further into the arrow rest by the adjustment mechanism to ensure a centershot. The button pin's preload is regulated by a button spring within a ball-end threaded preloader (threaded ball) via a preload screw. This allows for a certain degree of variation in the button pin's preload and pressure. The aforementioned components are secured by the eccentric lever and the rotating cylinder and moved by an angular movement through a magnetic system. This movement guides the button pin, button spring, ball-end threaded preloader, and preload screw out of the bow within a guide chamber of the button pin.All of this happens in a fraction of a second, namely the time it takes the arrow to fly through the bow. Since arrows vary in weight and thickness, the impact energy at the trigger pin differs. This energy can be adjusted through the interaction of the trigger spring, the ball-joint thread preload adjuster, and the preload screw on the eccentric lever, via the magnetic system and the magnetic preload screw. The magnetic preload screw locks the magnetic system and the rotating cylinder, thus influencing the resistance and sensitivity of the lever movement on the rotating cylinder.

[0046] To ensure guidance that adequately compensates for the falling weight, acceleration, and oscillation of the arrow, the interplay of spring tension and magnetic leverage is essential. Both are adjusted using only two screws located in the button body and the activation slot. To activate the entire mechanism or reactivate it after use, the eccentric lever is pushed back into the bow with a single finger movement. Drainage holes are provided in the button body to prevent rainwater from flooding the button body and the activation slot. If the user decides against the aforementioned arrow rest and arrow system, the entire body can be replaced with a plate, such as a metal plate, or a double-drilled mounting plate, allowing the installation of conventional arrow rests or arrow systems.

[0047] To ensure maximum performance and durability, the parts are made of stainless steel, high-strength aluminum, amorphous metals or metal alloys, preferably zirconium or titanium.

[0048] Alternatively, instead of actuation via a spring, actuation via air discharge through a small valve is possible.

[0049] Exemplary embodiments of the invention are explained in more detail below with reference to drawings.

[0050] They show Fig. 1a and Fig. 1b a top view and a sectional view of a device according to the invention for a throwing arm, Fig. 2a to 2f a tiller screw designed as a roller system, Fig. 3a and Fig. 3b a tool-free connection between the locking system and the central part, Fig. 4a and Fig. 4b the arrow rest according to the invention, Fig. 4c and Fig. 4d the arrow system according to the invention.

[0051] As from Fig. 1a and Fig. As can be seen in Figure 1b, the central part according to the invention for a bow comprises two limb pockets 1 for two limbs 2, the upper limb and the lower limb. In the Fig. Figure 1a shows the throwing arm pocket 1 of the middle section with a throwing arm 2 arranged therein.

[0052] The throwing arm is provided with a ball head 3, which is received in a receptacle 4 for the ball head 3 of the throwing arm 2 of the middle section.

[0053] The throwing arm 2 is secured to the central section by a tool-free locking system for positive locking of the throwing arm 2. This system comprises two catch arms 5, which are pivotable about a common axis 6 and have a locking mechanism 7, designed as a catch roller, at the end opposite the axis 6. These catch arms 5, equipped with a return spring 9, positively engage the area above the ball head 3 and are secured by a catch roller 9. They thus fix the ball head 3 in the receptacle 4 for the ball head. This connection can be released via an actuating element.

[0054] In the present example, the tiller screw 8 is designed with a hollow tiller screw body 11, which has an external thread for screwing into a receiving bolt 12 with a centering cone and an internal screw channel 13 for screwing in a locking set screw 14, as well as a tiller screw head 15, wherein the tiller screw head 15 has a screw cap with a scale. The tiller screw 8 has a screw cap 16 with a scale on its upper side, by means of which the tiller screw 8 can be adjusted.

[0055] In addition to being fixed in the receptacle 4 for the ball head 3, the throwing arm 2 is secured by the spring-loaded tiller screw 8, which extends through the throwing arm 2 so that it lies flat against the tiller screw head 15 below.

[0056] Through the interaction of the receptacle 4 for the ball head 3 of the bow arm 2 on the one hand and the tiller screw 8 on the other hand with the bow arm 2 itself, a counterforce to the bow arm movement is built up when the bow is drawn.

[0057] Alternatively to the one in Fig. The tiller screw 8 shown in 1b can, as in the Fig. As shown in Figures 2a to 2f, a roller body 17 is also provided, which has a thread 18 into which the tiller screw 8 can be screwed, wherein the end of the tiller screw 8 opposite the tiller screw head 15 engages in an opening of a pin knob 20 acted upon by a compression spring 19, which is arranged sliding in an opening 21 of the roller body 17 perpendicular to the direction of the thread 18, wherein a division mechanism 22 with a ball detent is arranged on the pin knob 20.

[0058] The Fig. 3a and Fig. Figure 3b shows a tool-free connection of the limb receiver 22 to the riser. This simplifies the assembly and replacement of the limb receiver, as both can be done without tools.

[0059] Here, the limb receptacle 22 is positively connected to the center section, wherein a guide, here a dovetail guide 23, is provided in the center section into which a sliding element 24 of the limb receptacle 22 with a corresponding shape can be inserted, and wherein, in the end position, a locking element is provided between the limb receptacle 22 and the center section. The locking element can be spring-operated or magnetically operated and can be manually released.

[0060] The Fig. 4a and Fig. Figure 4b shows the arrow rest according to the invention.

[0061] This arrow rest comprises a lifting plate 25, which can be pushed upwards by a release 26 and returned to its initial position by a return spring 27. A support cylinder 28 is rotatably mounted about its axis in the plane of the lifting plate 25 by means of a magnetic mechanism, and a support wire 29 is attached to the cylinder. The support wire 29 can thus be lowered onto the support bed 30 by rotating the support cylinder 28, or it can protrude from the support bed 30 in a raised position. The arrow rest is activated in this raised position.

[0062] When the shot is released, the support wire 29 folds into the support bed 30, i.e., into the plane of the lifting plate 25, after the arrow has been supported. A locking screw 31 of the magnetic mechanism serves to adjust its preload. The alignment of the support wire and its resistance can be adjusted via a locking screw, which is necessary, for example, for arrows with a higher weight. A setscrew is located in the support cylinder, allowing adjustment of the support wire in height and alignment with the arrow's central axis.

[0063] The arrow rest can be operated with one finger, readjusted during the shot, and fine-tuned using a tool. Handling is therefore very simple, and tuning is easy. The arrow rest can be made of stainless steel, aluminum, or amorphous metals or metal alloys based on zirconium or titanium, which offer exceptional springiness and a non-magnetic base, making the mechanism resistant to fatigue fractures or similar material failures.

[0064] The described arrow rest is arranged in a rest body, which can be connected to a central section. If the described arrow rest is not to be used, a replacement rest body can be inserted into the central section, allowing the use of a conventional arrow rest. The rest body preferably has a hole on the side facing the central section, which allows water to drain away if it penetrates due to weather conditions.

[0065] The arrow rest, also called a button, serves to compensate for irregular arrow oscillation, enabling it to pass the center line, the so-called centershot, during its forward movement through the bow. Like conventional buttons, the button according to the present invention also serves to cushion the arrow's oscillation. However, in the button according to the invention, a preload screw 32, an eccentric lever 33, and a rotary cylinder 34 pull out the button pin 35, thus eliminating any protruding part of the rest in the shooting window that the arrow could collide with during an incorrect release technique.

[0066] The centershot position of the 35-pin button can be locked by an adjustment mechanism. At its maximum extension, this mechanism should accommodate the smallest micro-diameter of an arrow in the centering position. Larger diameter arrows are screwed further into the arrow rest by the adjustment mechanism to ensure a centershot.

[0067] The preload of the button pin 35 is regulated by a button tension spring 36 in a ball-end threaded preloader 37 (threaded ball) via a preload screw. This allows for a certain degree of variation in the preload and pressure of the button pin 35. The aforementioned parts are attached via the eccentric lever 33 and the rotary cylinder 34 and moved by means of an angular movement by a magnetic system 38. This causes the button pin 35, the button tension spring 36, the ball-end threaded preloader 37, and the preload screw to move out of the bow in a guide chamber 39 of the button pin 35. All of this happens in a fraction of a second, namely the time it takes the arrow to fly through the bow.

[0068] Since arrows vary in weight and thickness, the impact energy at the button pin 35 differs. This energy can be adjusted by the interaction of the button tension spring 36, the ball sleeve thread preloader 37, and the preload screw on the eccentric lever 33 via the magnetic system 38 and the magnetic preload screw 40. The magnetic preload screw 40 serves to lock the magnetic system and the rotary cylinder 34, which influence the resistance and sensitivity of the lever movement on the rotary cylinder 34. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] EP 4 141 375 A1

[0007] DE 44 32 500 A1

[0008]

Claims

[1] A center section for a bow with limb holders for two limbs (2), wherein the center section has a tiller screw (8) with a spring system (10), characterized by , that in the limb receptacle the tiller screw (8) 14 for holding the end of the limb (2) and a receptacle (4) for the ball head (3) of a limb (2) are arranged, by the interaction of which with a limb (2) a counterforce to the limb movement when drawing the bow can be built up. [2] Middle part according to claim 1, characterized by , that the receptacle (4) for the ball head (3) of a throwing arm (2) is designed as a spherical cap or as a cone. [3] Middle part according to claim 1 or claim 2, characterized by , that the receptacle for the ball head (3) of a throwing arm (2) comprises a preferably tool-free locking system (5, 6, 7) for positive locking fixation of the throwing arm (2). [4] Middle part according to any one of claims 1 to 3, characterized by, that the tiller screw (8) is designed as a hollow tiller screw body (11) which has an external thread for screwing into a receiving bolt (12) with centering cone and an internal screw channel (13) for screwing in a fixing set screw (14) as well as a tiller screw head (15) wherein the tiller screw head (15) has a screw cap (16) with scale. [5] Middle part according to any one of claims 1 to 3, characterized by , that a roller body (17) is provided which has a thread (18) into which the tiller screw (8) can be screwed, wherein the end of the tiller screw (8) opposite the tiller screw head (11) engages in an opening (21) of a pin knob (20) acted upon by a compression spring (19), which is arranged sliding in an opening of the roller body (17) perpendicular to the direction of the thread, wherein a division mechanism with a ball detent is arranged on the pin knob (20). [6] Middle part according to any one of claims 1 to 5, characterized by , that the limb receptacle (22) can be connected to the middle section without tools. [7] Middle part according to any one of claims 1 to 6, characterized by that the limb receptacle (22) can be positively connected to the middle section, wherein a guide, preferably a dovetail guide (23), is provided in the middle section, into which a sliding element (24) of the limb receptacle (22) with a corresponding shape can be inserted, and wherein in the end position a preferably spring-operated or magnetically operated locking element is provided between the limb receptacle (22) and the middle section. [8] Middle part according to any one of claims 1 to 7, characterized by that the middle part consists of fiber-reinforced composite materials, wherein the fiber-reinforced composite materials are selected from the group consisting of • Plastics, especially aramids and acrylates, • Fiber-reinforced plastics, in particular glass fiber reinforced plastic (GFRP) and carbon fiber reinforced plastic (CFRP), • crystalline or amorphous metals, especially aluminium, magnesium and steel, • organic natural materials, especially wood or bamboo, • mineral natural substances, especially basalt and gneiss. [9] Middle part according to any one of claims 1 to 8, characterized by , that the body of the middle part is designed as a grid or honeycomb structure, with a transverse reinforcing plane preferably provided at the outer edges. [10] Middle part according to any one of claims 1 to 9, characterized by , that the middle part has a handle shell which is individually shaped using artificial intelligence based on a 3D scan of the user's hand and on empirical data.

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