Energy store comprising composite material, and tool having energy store comprising composite material

Abstract

A tool for driving a fastening element into a substrate, wherein the tool comprises an energy transmission system; wherein the energy transmission system comprises an energy store for storing mechanical energy in the tool; and wherein the energy store comprises a bending spring and a composite material.

Description

[0001] Composite energy storage system and working device with composite energy storage system

[0002] The present invention relates to a tool for driving a fastener into a substrate and an energy storage device for storing mechanical energy in a tool. Such tools typically have an electrical energy source – for example, an electric battery – and an energy transfer system that transfers the electrical energy from the electric battery to the fastener in the form of mechanical energy.

[0003] The energy transfer system comprises an energy transfer belt that converts electrical energy into mechanical energy and transfers it to an energy storage device. This energy storage device serves as an intermediate storage unit for the mechanical energy. The mechanical energy is then transferred from the energy storage device to an energy transfer element, which in turn transmits the energy to a fastening element, driving this element into the ground.

[0004] background

[0005] Driving fasteners requires a high power output from the batteries. These batteries have a high energy density but can only provide a very limited amount of power. Therefore, all battery-powered devices require an energy storage system to store mechanical energy. This energy storage system allows the energy needed to drive fasteners to be released very quickly, thus achieving the required high power output.

[0006] The general trend is towards developing battery-powered devices for applications requiring higher drive energy. This will allow combustion-based devices to be replaced. Battery-powered devices are easier to handle, less expensive, and have a significantly better CO2 balance than combustion-based devices. A generic energy storage device for storing mechanical energy in a working tool is known from DE102019109554 A1. This patent describes a bending spring element made of fiber-reinforced plastic composite material, designed for optimized bending performance and structural integrity. It comprises cover layers made of a fiber-reinforced plastic composite material with parallel-aligned fibers and a spacer element between these layers made of a second, different fiber-reinforced plastic composite material.This design improves the flexibility and damping properties of the spring element and allows for curvatures without significant structural loads.

[0007] The patent application DE102014110558 A1 deals with a flexible element made of fiber-reinforced plastic, intended to serve as a bending spring element. This component is structured in such a way that its flexibility and elasticity are improved through a specific arrangement and orientation of the fiber materials. DE102014110558 A1 describes in detail how the fibers are embedded in the composite material to achieve the desired mechanical properties and durability. This makes it useful in industries such as automotive, aerospace, and consumer electronics, where lightweight and high-strength materials are crucial.

[0008] A generic tool is known from US 2007 / 0007319 A1. US 2007 / 0007319 A1 describes a fastener-driving tool that is efficient, lightweight, and provides sufficient energy to drive a fastener. The tool has a housing assembly and a nose assembly connected to it, as well as a magazine that provides the fasteners. A motor moves the energy transfer element by means of a return stroke, and a composite spring drives the energy transfer element by means of a strike stroke. The tool includes exactly one energy storage device designed as a spring. The spring is made of a composite material and is designed as a helical or torsion spring. US 2007 / 0007319 A1 also describes a detailed arrangement of the drive system, which uses a battery as the electrical energy source.German patent application DE102006000139 B3 describes a hand-held driving tool suitable for faster and more efficient driving of fasteners. It includes a drive spring element made of fiber-reinforced plastic, which is lighter and allows for higher driving speeds and energies than conventional metal springs. The spring consists of several segments made of materials such as fiberglass, carbon fiber, or aramid.

[0009] DE102008054816 A1 describes a hand-held driving device, optimized in particular for the use of composite springs. The invention aims to solve problems in force transmission to the spring that can occur in traditional designs due to the changing pitch of the spring coils during compression. A special force application element is attached to the ends of the drive spring element, enabling a central and uniform force application, even if the shape of the spring changes under load.

[0010] DE102007000226 A1 is considered the closest prior art and describes a hand-held driving tool with a movable energy transfer element. A mechanical drive spring, which can be tensioned via a tensioning mechanism, serves as the drive source for the energy transfer element. An advantage of this is that the mechanical drive spring is inexpensive, making such a driving tool cost-effective to manufacture. Furthermore, mechanical springs have the advantage over gas springs that tensioning a mechanical spring does not cause temperature increases, as does tensioning gas springs, and that a tensioned spring does not lose its stored energy over a long period, whereas energy is gradually lost through leakage in a gas spring. This driving tool has the disadvantage that only relatively low setting energies can be achieved and that these contribute significantly to the recoil of the driving tool during a setting operation.

[0011] One object of the present invention is to overcome the disadvantages of the nearest prior art and to increase the potential energy of the energy storage device while simultaneously reducing the weight of the energy storage device and / or the working device.

[0012] Description

[0013] A first aspect of the invention comprises a tool for driving a fastener into a substrate, comprising an energy transfer system, wherein the energy transfer system includes an energy storage device for storing mechanical energy in the tool, and wherein the energy storage device comprises at least one bending spring and a composite material. At least one technical benefit of this aspect is that a bending spring, which preferably comprises a composite material, can be constructed in a compact or spatially optimized manner, thus enabling access to more—especially difficult—fastening points. Therefore, the tool has a broader range of applications compared to generic devices from the prior art.An additional technical benefit is that the integration of the bending spring into the energy transfer system allows for significantly higher insertion energies than with conventional tools of the claimed type. This additional technical benefit also expands the application range of the tool. The term "bending spring" includes, among other things, springs that can be subjected to compressive and / or tensile loads. Within the scope of the invention, C-springs, helical springs, compression springs, and tension springs are considered "bending springs." The tool comprises at least one bending spring, but can also include between two and six bending springs, in particular four. The term "composite material" includes, among other things, fibers and a matrix material. The fibers and the matrix material can be present separately and only mixed during the manufacturing process of the energy storage device.The technical benefit of the fibers lies in their ability to absorb tensile and compressive stresses. The technical benefit of the matrix lies in its ability to absorb shear stresses. It is also possible for the fibers and matrix material to be mixed before the manufacturing process. In this case, it is referred to as a "prepreg" material. Preferably, unidirectionally oriented fibers are used in prepreg materials. Advantageously, the fibers are oriented in the direction of maximum compressive and tensile stress. The technical benefit of unidirectionally oriented fibers is that the tensile and compressive strength of the flexural spring is increased. The fiber content is between 35% and 75%, particularly between 45% and 65%.

[0014] In a further embodiment, the invention comprises a working device having an energy storage device with an energy density of at least 500 J / kg. The term "energy density" includes, among other things, the amount of energy that can be temporarily stored in the energy storage device per kilogram of its own weight and / or that can be transferred from the energy storage device to the fastening element. Alternatively, the invention comprises a working device wherein the energy storage device has an energy density of at least 600 J / kg, preferably at least 650 J / kg, more preferably at least 750 J / kg, and particularly preferably at least 950 J / kg. At least one technical benefit of this further embodiment and these alternatives is that the driving energy can be increased while simultaneously reducing the weight.

[0015] In a further embodiment, the invention comprises an energy transmission system comprising at least one roller holder for mounting the bending spring in the working device, wherein the bending spring includes a bearing contact surface for contacting the bending spring with the roller holder. The term "bearing contact surface" includes, among other things, a surface section on the bending spring which is designed to be in contact with, i.e., touching, a part of the roller holder. The bearing contact surface can be located on one and / or different sections of the bending spring. Alternatively, the invention comprises a working device wherein the bearing contact surface of the bending spring is planar, concave, or convex.At least one technical advantage of this further embodiment and the alternative is that the bending spring, and thus the energy storage device, can be integrated into the working device without requiring a dedicated mounting element. This results in a smaller and lighter working device. Another technical advantage is that the relative position of the roller holder within the housing of the working device can be changed. This relative position changes whenever mechanical energy is added to or removed from the energy storage device. In a further embodiment, the invention comprises a working device in which the roller holder includes a bearing element, allowing relative movement between the bearing contact surface of the bending spring and the cylindrical surface of the bearing element in a circumferential direction.The term "bearing element" includes, among other things, a cylindrical body on whose lateral surface, i.e., in a circumferential direction of the bearing element, the bending spring and the bearing element can move relative to each other. Furthermore, the "bearing element" can also comprise a non-ideal cylindrical body outside the contact area with the bending spring, which may deviate from a cylindrical shape for manufacturing reasons. Alternatively, the invention includes a working device wherein the lateral surface of the bearing element is flat, concave, or convex. At least one technical advantage of this further embodiment and the alternative is that the roller holder for supporting the bending spring, and thus the energy storage device, can be easily implemented in the working device. This results in a smaller and lighter working device.

[0016] In a further embodiment, the invention comprises a working device, wherein the energy transmission system includes at least one support bracket for supporting the bending spring in the working device, the bending spring comprising a support contact surface for contacting the bending spring with the support bracket. The term "support bracket" includes, among other things, an element on which the bending spring can be supported or clamped so that forces can be transmitted from the bending spring to the housing of the working device. The term "support contact surface" includes, among other things, a surface section on the bending spring which is designed to be in contact with, i.e., touching, a part of the support bracket. The support contact surface can be located on one and / or different surfaces of the bending spring. Furthermore, the bending spring can be supported or fixed to the working device at the support contact surface.Alternatively, the invention comprises a working device wherein the support contact surface of the bending spring is flat, concave, or convex. At least one technical advantage of this further embodiment and the alternative is that the bending spring, and thus the energy storage device, can be integrated into the working device without requiring a dedicated element for support or fixation within the device. This results in a smaller and lighter working device.

[0017] In a further embodiment, the invention comprises a working device wherein the support holder includes a support element such that relative movement between the support contact surface of the bending spring and a circumferential surface of the support element is possible in a circumferential direction of the support element. The term "support element" includes, among other things, a cylindrical body on whose circumferential surface, i.e., in a circumferential direction of the support element, the bending spring and the support element can move relative to each other. Furthermore, the "support element" can also comprise a non-ideal cylindrical body outside the contact surface with the bending spring, which may deviate from a cylindrical shape for manufacturing reasons. Alternatively, the invention comprises a working device wherein the circumferential surface of the support element is planar, concave, or convex.At least one technical benefit of this further embodiment and the alternative is that the support bracket for supporting or fixing the bending spring, and thus the energy storage device, in the working tool can be easily implemented. This results in a smaller and lighter working tool.

[0018] In a further embodiment, the invention comprises a working device wherein the support holder is fixedly connected to a housing of the working device, such that the support holder is fixedly positioned within the housing of the working device. The term "fixedly positioned" includes, among other things, the relative position of the support holder within the housing of the working device. This relative position is fixed and does not change even when mechanical energy is added to or removed from the energy storage device. At least one technical benefit of this further embodiment is that the support holder is suitable for supporting or fixing more than one bending spring. In particular, the support holder is suitable for supporting or fixing two bending springs. This results in a smaller and lighter working device.

[0019] In a further embodiment, the invention comprises a working device wherein the bending spring has a first outer surface with a first radius of curvature and a second outer surface with a second radius of curvature, wherein the bending spring comprises a curvature section in which the first radius of curvature and the second radius of curvature are different. The term "curvature section" includes, among other things, a partial region of the bending spring in which the first outer surface has at least one first radius of curvature and the second outer surface has at least one second radius of curvature. In a curvature section, the first outer surface can comprise two or more first radii of curvature and the second outer surface can comprise two or more second radii of curvature. The first radii of curvature of the first outer surface can be the same or different from each other. The second radii of curvature of the second outer surface can be the same or different from each other.A curvature section begins when the radius of curvature is greater than 0 mm and less than 100 mm. A curvature section ends when the radius of curvature is close to 0 mm or greater than 100 mm. The bending spring can comprise one or more curvature sections. The difference between the first and second radii of curvature corresponds to the spring thickness D. The spring thickness D is in the range of 3 mm to 9 mm, preferably between 5 mm and 7 mm, and 6 mm is particularly preferred. At least one technical benefit of this further embodiment is that the size of the bending spring is reduced. This results in a smaller and lighter tool.

[0020] In a further embodiment, the invention comprises a working device, wherein the curved section includes the bearing contact surface of the bending spring and / or the support contact surface of the bending spring. At least one technical advantage of this further embodiment is that the bending spring, and thus the energy storage device, can be integrated into the working device without requiring a dedicated element for bearing or support within the device. A further technical advantage is that the curved section fulfills two functions simultaneously. For the first alternative (bearing contact surface), the curved section provides a contact surface to the roller holder and increases the tensile and compressive strength of the bending spring. For the second alternative (support contact surface), the curved section provides a contact surface to the support holder and increases the tensile and compressive strength of the bending spring.The aforementioned technical effects result in a smaller and lighter piece of equipment.

[0021] In a further embodiment, the invention comprises a working device in which the energy transfer system comprises an energy transfer belt and the energy storage device comprises at least two bending springs. The expression "at least two bending springs" includes, but also includes, more than two bending springs, for example, three, four, five, six, seven, eight, nine, or ten bending springs. An even number of bending springs is preferred. At least one technical effect of this further embodiment is that the potential energy stored in the energy storage device can be distributed uniformly within the working device. In addition, the at least two bending springs reduce the tensile and compressive stresses on the working device—especially on the housing of the working device. Thus, both the durability of the working device and the required energy density of the device can be ensured.The term "energy transmission belt" includes, among other things, a rope- or ribbon-shaped transmission means as shown in DE102007000226 A1. At least one technical effect of this further embodiment is to transfer the electrical energy from the battery to the fastening element in the form of mechanical energy.

[0022] In a further embodiment, the invention comprises a working device wherein the resulting forces of the at least two bending springs on the roller holder and / or on the support holder define a plane of action W, wherein the longitudinal axis of an energy transfer element is located at least partially in this plane of action W. An even number of bending springs is preferred. At least one technical effect of this further embodiment is that the even number of bending springs act with a direct line of force on the even number of roller holders and / or support holders. A tensioned bending spring exerts a force that displaces the roller holder in the direction of movement. This avoids lateral forces and bearing friction, leading to higher efficiency and a lighter device. An even number of springs and roller holders also allows them to move in opposite directions.This cancels out their inertial forces within the device. This reduces the recoil the user feels when driving in the nail.

[0023] A second aspect of the invention comprises an energy storage device for storing mechanical energy in a working device, wherein the energy storage device comprises a composite material with unidirectional fibers and a bending spring with a bearing contact surface and / or support contact surface. At least one technical effect of this second aspect is that the bending spring, and thus the energy storage device, can be installed in a working device without the bending spring, and thus also the energy storage device, requiring a dedicated element for its mounting in the working device.

[0024] In a further embodiment, the invention comprises an energy storage device wherein the unidirectional fibers are aligned along a circular segment in the area of ​​the bearing contact surface and / or the support contact surface. At least one technical benefit of this further embodiment is that, due to the arrangement of the fibers, the bearing contact surfaces and the support contact surfaces of the bending spring can be used for mounting the bending spring in a working device. This allows the bending spring, and thus also the energy storage device, to be integrated into the working device without requiring a dedicated element for support, fixation, or mounting within the working device. This results in a smaller and lighter working device.

[0025] In a further embodiment, the invention comprises an energy storage device wherein the unidirectional fibers are oriented in the direction of a tensile and compressive stress of the bending spring, wherein the bending spring has at least one fabric layer and / or one non-woven layer whose fiber direction is oriented at 45° to the unidirectional fibers. At least one technical benefit of this further embodiment is to connect the unidirectionally oriented fibers in the transverse direction in addition to the matrix material. Another technical benefit is that the use of fabric and / or non-woven layers reduces the inclusion of air bubbles. This leads to lower stress peaks in the energy storage device and thus also to a longer service life. In a further embodiment, the invention comprises an energy storage device wherein the fabric layer and / or the non-woven layer are arranged on an outer surface of the bending spring.At least one technical benefit of this further embodiment is the prevention of air bubbles. This results in fewer voltage spikes in the energy storage device and thus also a longer service life.

[0026] Further optional embodiments follow, which can be combined or specified arbitrarily with all previous embodiments of the first and second aspects and also with all further optional embodiments of the first and second aspects.

[0027] In a further optional embodiment, the invention comprises a working device, wherein the energy transfer system includes an energy storage device, a roller holder, an energy transfer belt, a spindle, and an energy transfer element. The energy transfer system comprises at least one roller holder, but can also include two, three, or four roller holders. The roller holder includes at least one roller element for guiding the energy transfer belt, but can also include two, three, or four roller elements. The roller elements constitute the basic elements of the pulley-based transmission mechanism. Preferably, the working device comprises two roller holders, each with two roller elements. This results in a gear ratio of 1:4.

[0028] The energy transfer element thus moves four times faster than the energy storage device when the bending springs relax. A high

[0029] Driving speed is necessary for driving fasteners such as nails into steel or concrete substrates. Therefore, the stroke of the energy transfer element is four times greater than the stroke of the energy storage device.

[0030] In a further optional embodiment, the invention comprises a working device wherein the energy storage element comprises a torsion spring. In this embodiment, the working device comprises at least one torsion spring, but it can also comprise between two and six torsion springs, in particular four. The term "torsion spring" includes, among other things, springs that can be subjected to torsional loads. Within the scope of the invention, helical springs and torsion bars are considered "torsion springs," among others. At least one technical advantage of these alternatives is that a torsion spring can be constructed very lightly, thus reducing the weight of the working device.

[0031] In a further optional embodiment, the invention comprises a working device wherein the energy storage unit includes two torsion springs arranged one inside the other. Here, both torsion springs are connected torsionally rigidly at a common end. The inner torsion bar would, for example, be fixedly mounted at one end to prevent rotation. The torque is transmitted through the inner torsion bar, via the fixed mounting, to the outer torsion bar, which in turn transmits the torque. At least one technical benefit of these alternatives is that the stiffness of the bar is increased by the lengthening of the torsion spring. This extends the service life of the working device and makes its design more compact.

[0032] In a further optional embodiment, the invention comprises a working device, wherein the fibers used can include glass fibers, carbon fibers, or aramid fibers. Glass fibers are preferably used. At least one technical advantage of these alternatives is that the elongation at break is significantly greater than, for example, that of carbon fibers. In addition, glass fiber prepreg layers are considerably less expensive. This allows the spring to be made smaller and simplifies the manufacturing process. Carbon fiber-based prepreg material has at least the technical advantage of higher tensile and compressive strength and lower density compared to glass fiber-based prepreg material.

[0033] In a further optional embodiment, the invention comprises a working device wherein the composite material used comprises fibers and a thermoset, e.g. epoxy resin, or can be constructed from fibers and thermoplastic.

[0034] In a further optional embodiment, the invention comprises a working device wherein the first radius of curvature and / or the second radius of curvature lies within at least one of the following ranges: i. 5 mm to 80 mm; ii. 10.5 mm to 77 mm; iii. 11.5 mm to 76 mm; iv. 12.0 mm to 75.5 mm; v. 13 mm to 74.5 mm.

[0035] At least one technical advantage of this embodiment is that the first radius of curvature and / or the second radius of curvature encompass values, or lie within a range of values ​​for radii of curvature, whereby the bending spring exhibits the tensile, compressive, and shear strength required for a tool used to drive a fastener into a substrate. A further technical advantage of this embodiment is that individualized values, corresponding to the designed load, can be achieved for both the tensile and compressive strength and the shear strength.

[0036] In a further optional embodiment, the invention comprises a working device wherein the bending spring comprises a longitudinal section in which the first radius of curvature and the second radius of curvature have a value greater than 100 mm or the first radius of curvature and the second radius of curvature have a value of 0 mm.

[0037] The term "longitudinal section" encompasses at least one sub-section of the bending spring in which the first outer surface has a first radius of curvature that is 0 mm or very close to it, and the second outer surface has a second radius of curvature that is 0 mm or very close to it. Furthermore, the term "longitudinal section" also encompasses at least one sub-section of the bending spring in which the first outer surface has such a large first radius of curvature and the second outer surface has such a large second radius of curvature that the sub-section of the bending spring is almost flat and thus virtually uncurved. This is achieved with a value greater than 100 mm. In a longitudinal section, the first outer surface has a first radius of curvature and the second outer surface has a second radius of curvature. A longitudinal section begins when the radius of curvature is close to 0 mm or greater than 100 mm.The longitudinal section ends when the radius of curvature is greater than 0 mm and less than 100 mm. The bending spring can comprise one or more longitudinal sections. At least one technical benefit of this further embodiment is that the size of the bending spring is reduced. This results in a smaller and lighter tool.

[0038] In a further optional embodiment, the invention comprises a working device wherein the bending spring has at least one section combination from the following list: i. At least three curved sections and at least two longitudinal sections; ii. At least four curved sections and at least three longitudinal sections; iii. At least five curved sections and at least four longitudinal sections; iv. At least six curved sections and at least five longitudinal sections; v. At least seven curved sections and at least six longitudinal sections.

[0039] The term "section combination" encompasses at least two distinct sections of the bending spring—that is, at least one curved section and at least one longitudinal section. The term "section combination" includes both an alternating sequence of at least one curved section and at least one longitudinal section, as well as a repeating sequence of either a curved section or a longitudinal section. A combination of alternating and repeating sequences is also encompassed by the term "section combination."

[0040] Alternative i) of this embodiment includes, among other things, three curved sections and two longitudinal sections. Two of the three curved sections may comprise a bearing contact surface of the bending spring and / or the support contact surface of the bending spring. In such a case, the bending spring of alternative i) corresponds to a single C-shape with two curved sections for bearing and / or supporting the bending spring. Alternative ii) of this embodiment includes, among other things, four curved sections and three longitudinal sections. Two of the four curved sections may comprise a bearing contact surface of the bending spring and / or the support contact surface of the bending spring. In such a case, the bending spring of alternative ii) corresponds to an S-shape or a double C-shape with two curved sections for bearing and / or supporting the bending spring.

[0041] Alternative iii) of this embodiment comprises, among other things, five curved sections and four longitudinal sections. Two of the five curved sections may comprise a bearing contact surface of the bending spring and / or the support contact surface of the bending spring. In such a case, the bending spring of alternative iii) corresponds to an M-shape or a triple-C-shape with two

[0042] Curved sections for storing and / or supporting the bending spring.

[0043] Alternative iv) of this embodiment includes, among other things, six

[0044] Curved sections and five longitudinal sections. Two of the six curved sections can comprise a bearing contact surface of the bending spring and / or the support contact surface of the bending spring. In such a case, the bending spring of alternative iv) corresponds to a double-S shape or a quadruple-C shape with two curved sections for bearing and / or supporting the bending spring.

[0045] Alternative v) of this embodiment includes, among other things, seven curved sections and six longitudinal sections. Two of the seven curved sections may comprise a bearing contact surface of the bending spring and / or the support contact surface of the bending spring. In such a case, the bending spring of alternative v) corresponds to a five-fold C-shape with two curved sections for bearing and / or supporting the bending spring.

[0046] The list of alternatives to this embodiment is not exhaustive. Any n-fold C-shape is feasible and encompassed by this embodiment. In principle, an n-fold C-shape results in at least n+2 curvature segments and at least n+1 longitudinal segments. For example, an 8-fold C-shape therefore comprises at least 10 curvature segments and at least 9 longitudinal segments.

[0047] At least one technical benefit of this further embodiment is that alternatives i) to v) exhibit a specific tensile and compressive strength to ensure the required service life of the working device or energy storage device and the bending spring. A further technical benefit is that, through different shapes (C-shape to n-fold C-shape), the buckling stiffness is always guaranteed for bending springs of varying sizes and lengths. This allows for different energy densities of the energy storage device and also enables the realization of working devices of varying sizes – according to the requirements profile of the device application.

[0048] In a further optional embodiment, the invention comprises a working device wherein the curvature section includes at least one curvature gradient from the following list: i. The curvature gradient is constant; ii. The curvature gradient increases; iii. The curvature gradient decreases.

[0049] Alternative i) of this embodiment includes, among other things, a curvature section in which the curvature gradient does not change. Thus, both the first outer surface and the second outer surface always have a constant first radius of curvature and a constant second radius of curvature. In other words, in alternative i) of this embodiment, the radius of curvature within the curvature section does not change for either the first outer surface or the second outer surface.

[0050] Alternative ii) of this embodiment includes, among other things, a curvature section in which the curvature gradient increases. Thus, the first outer surface has a first radius of curvature that increases, and the second outer surface also has a second radius of curvature that increases. In other words, in alternative ii) of this embodiment, the radius of curvature increases at least once within the curvature section. The radius of curvature—of both the first and second outer surfaces—can also increase further within the curvature section.

[0051] Alternative iii) of this embodiment includes, among other things, a curvature section in which the curvature gradient decreases. Thus, the first outer surface has a first radius of curvature that decreases, and the second outer surface also has a second radius of curvature that decreases. In other words, in alternative iii) of this embodiment, the radius of curvature decreases at least once within the curvature section. The radius of curvature—of both the first and second outer surfaces—can also decrease further within the curvature section.

[0052] The alternatives of these embodiments can be combined as desired. For example, the curvature gradient within a curvature section can increase (Alternative II), then remain constant (Alternative I), and finally decrease again (Alternative III). This example thus shows the combination II-I-III of the alternatives of this embodiment. At least one technical benefit of this optional embodiment is that the curvature gradient makes the manufacturing of the bending spring easier. Another technical benefit is that a load-specific bending spring shape can be realized. This extends the service life of the working tool and makes its design more compact.

[0053] At least one technical benefit of this optional embodiment is that the tensile and compressive strength of the bending spring can be customized for the load range. This extends the service life of the tool and makes its design more compact. Another technical benefit is that a continuous geometry, i.e., a slowly changing curvature gradient, is achieved to avoid stress peaks. This also extends the service life of the tool. In a further optional embodiment, the invention comprises a tool wherein the first outer surface and the second outer surface are opposite each other and / or parallel to each other. The term "opposite each other" includes, among other things, that the two outer surfaces preferably do not touch.The term "parallel to each other" implies that the two outer surfaces are equidistant from the median plane of the two outer surfaces. The term "median plane" refers to the plane located at the midpoint between the two outer surfaces. At least one technical benefit of this embodiment is that a bending spring, preferably comprising a composite material, can be constructed in a compact and spatially optimized manner, thus enabling access to more—especially difficult—fixing points.

[0054] In a further optional embodiment, the invention comprises a working device wherein the roller holder and / or the support holder include a stop surface. The term "stop surface" encompasses a surface of any shape—curved, cylindrical, or flat—which can stop or alternatively slow down the movement of the bending spring along the circumferential direction of the bearing element or along the circumferential direction of the support element. At least one technical effect of this optional embodiment is that it improves the functionality of the roller holder and / or the support holder. This improves and extends the reliability and service life of the working device.

[0055] In a further optional embodiment, the invention comprises a working device wherein the bearing element and / or the support element is either fixed or rotatable. The term "fixed" implies that the bearing element cannot rotate about its longitudinal axis. The term "rotatable" implies that the bearing element can rotate about its longitudinal axis. At least one technical benefit of this optional embodiment is that the roller holder for mounting the bending spring and / or the support holder for supporting the bending spring, and thus the energy storage device, can be easily implemented in the working device. This results in a smaller and lighter working device.

[0056] In a further optional embodiment, the invention comprises a working device wherein a first longitudinal section has a greater width than a second longitudinal section and / or than at least one curved section. At least one technical effect of this optional embodiment is that the shear stress strength in this first longitudinal section with greater width is higher than in the second longitudinal section and / or than in the at least one curved section. This increases the permissible shear stress of the bending spring and thus the service life of the working device, and makes the design of the working device more compact.

[0057] In a further optional embodiment, the invention comprises a working tool which has a working tool efficiency of between 10% and 40%, preferably between 20% and 30%, and particularly preferably 25%. Furthermore, the working tool can also have a working tool efficiency of 15% or 35%. The term "working tool efficiency" refers to the ratio of the energy transferred to a fastening element per driving operation to the energy drawn from the electrical storage of an electric battery per driving operation. This extends the battery life of the working tool and reduces the frequency of charging.

[0058] In a further optional embodiment, the invention comprises a working tool which has an energy storage efficiency of between 65% and 90%, preferably between 70% and 85%, and particularly preferably 80%. The term "energy storage efficiency" refers to the ratio of the energy transferred to a fastening element per driving operation to the energy released as potential energy from the mechanical energy storage device per driving operation. This reduces the weight of the working tool, increases the setting rate of the working tool, and reduces the cooling requirements of the working tool.

[0059] In a further optional embodiment, the invention comprises a working device wherein the support holder includes at least two support contact surfaces. At least one technical benefit of this optional embodiment is that at least two bending springs can be contacted or attached to a support holder. This makes the design of the working device more compact. In a further optional embodiment, the invention comprises a working device wherein the support holder or the support element includes a damper. At least one technical benefit of this optional embodiment is that the force transmitted by the bending spring(s) to the support holder or the support element is not completely transmitted to the housing of the working device but is partially absorbed by the damper. This extends the service life of the working device.

[0060] In a further optional embodiment, the invention comprises a working device wherein the longitudinal section can have a constant thickness and / or a converging thickness and / or a diverging thickness. The term "constant thickness" includes the fact that the distance of the first outer surface to the median plane and the distance of the second outer surface to the median plane in the longitudinal section can remain constant in the direction of the setting direction X. The term "converging thickness" includes the fact that the distance of the first outer surface to the median plane and the distance of the second outer surface to the median plane in the longitudinal section can decrease in the direction of the setting direction X. The term "diverging thickness" includes the fact that the distance of the first outer surface to the median plane and the distance of the second outer surface to the median plane in the longitudinal section can increase in the direction of the setting direction X.At least one technical benefit of this optional embodiment is that the buckling strength of the longitudinal section, and thus of the spring, can be improved. This extends the service life of the tool. At least one further technical benefit of this optional embodiment is that the tensile and compressive strength of the longitudinal section can be customized depending on the load. This reduces the weight of the tool and makes its design more compact.

[0061] In a further optional embodiment, the invention comprises a working device wherein the first radius of curvature and / or the second radius of curvature comprises at least one value from the following list: i. 12 mm; ii. 15.5 mm; iii. 19 mm; iv. 22.5 mm; v. 44 mm; vi. 47.5 mm; vii. 51 mm; viii. 54.5 mm; ix. 58 mm; x. 68.5 mm; xi. 72 mm; xii. 75.5 mm.

[0062] At least one technical advantage of this embodiment is that the first radius of curvature and / or the second radius of curvature comprise values ​​that enable the bending spring to possess the tensile, compressive, and shear strength required for a tool used to drive a fastener into a substrate. A further technical advantage of this embodiment is that individualized values, corresponding to the intended load, can be achieved for both the tensile and compressive strength and the shear strength.

[0063] In a further optional embodiment, the invention comprises a working device and / or an energy storage device, wherein the bending spring comprises at least one layer of woven fabric and / or non-woven material. The term "woven fabric" includes, among other things, a layer that also comprises a matrix material. In contrast, the term "non-woven material" includes a layer that does not comprise a matrix material. At least one technical benefit of this embodiment is that air bubbles trapped in the composite material by the woven fabric and / or non-woven material are better prevented, thus reducing stress peaks in the composite material. This increases the service life of the working device and / or the energy storage device.

[0064] In a further optional embodiment, the invention comprises a working device and / or an energy storage device, wherein the bending spring has at least one layer of fabric and / or non-woven material in the central plane of the bending spring. At least one technical effect of this embodiment is that the fabric and / or non-woven material in the central plane of the bending spring achieves higher shear strengths by preventing air inclusions.

[0065] This increases the lifespan of the working device and / or the energy storage device.

[0066] In a further optional embodiment, the invention comprises a working device and / or an energy storage device, wherein the bending spring has at least one layer of fabric and / or non-woven material on the first and / or second outer surface of the bending spring. At least one technical effect of this embodiment is that the outer surfaces of the bending spring are reinforced by the fabric and / or non-woven material. This increases the service life of the working device and / or the energy storage device. In particular, the wear resistance in the area of ​​the bearing element and / or the support element can be increased.

[0067] In a further optional embodiment, the invention comprises a working device and / or an energy storage device, wherein the matrix material used includes at least one value for shear stress strength from the following list: i. 80 MPa; ii. 90 MPa; iii. 100 MPa; iv. 110 MPa; v. 120 MPa; vi. 122 MPa; vii. 130 MPa.

[0068] At least one technical effect of this optional embodiment is that the shear stress strength of the bending spring, and thus also of the energy storage device and the working tool, is increased. This extends the service life of the working tool and the energy storage device.

[0069] In a further optional embodiment, the invention comprises a working device and / or an energy storage device, wherein the bending spring has a utilization factor of at least 0.1, preferably in the range of 0.11 to 0.5, and particularly preferably in the range of 0.11 to 0.33. The term "utilization factor" describes the ratio of the stresses in the spring cross-section to a uniform stress distribution. The uniform stress distribution is designed to meet the stress for the planned service life. At least one technical benefit of this optional embodiment is that the weight of the bending spring, and thus of the working device, can be reduced. This results in a more compact design of the working device.

[0070] In a further optional embodiment, the invention comprises a working device and / or an energy storage device, wherein the fibers of the composite material have a length in the range of 20 to 300 mm and / or a width in the range of 5 to 30 mm.

[0071] Examples of implementation

[0072] The invention is explained in more detail below with reference to exemplary embodiments and the drawings.

[0073] Figure 1 shows an isometric view (Figure 1a) and a side view (Figure 1b) of an embodiment of a bending spring according to the invention comprising an S-shape and a double-C-shape, respectively.

[0074] Figure 2 shows an isometric view (Figure 2a) and a side view (Figure 2b) of an embodiment of a bending spring according to the invention comprising a simple C-shape.

[0075] Figure 3 shows an isometric view (Figure 3a) and a side view (Figure 3b) of an embodiment of a bending spring according to the invention comprising an M-shape and a triple-C-shape, respectively.

[0076] Figure 4 shows an isometric view (Figure 4a) and a side view (Figure 4b) of a bending spring comprising a double S shape and a quadruple C shape, respectively.

[0077] Figure 5 shows an isometric view (Figure 5a) and a side view (Figure 5b) of a bending spring comprising a five-fold C-shape. Figure 6 shows a side view of an embodiment of a working device according to the invention comprising four bending springs, each having an S-shape or a double C-shape.

[0078] Figure 7 shows an isometric view (Figure 7a), a longitudinal section (Figure 7b) and a cross-section (Figure 7c) of an embodiment of an energy storage device according to the invention, comprising four bending springs, each having an S-shape or a double-C shape and arranged within the energy transfer band.

[0079] Figure 8 shows an isometric view (Figure 8a) and a cross-section (Figure 8b) of an embodiment of an energy storage device according to the invention, comprising four bending springs, each having an S-shape or a double-C shape and arranged next to the energy transfer belt.

[0080] Figure 9 shows another embodiment of an energy storage device according to the invention, comprising four bending springs, each of which has a simple C-shape and is arranged within the energy transfer belt.

[0081] Figure 10 shows another embodiment of an energy storage device according to the invention, comprising four bending springs, each of which has a simple C-shape and is arranged outside the energy transfer band.

[0082] Figure 11 shows another embodiment of an energy storage device according to the invention, comprising four bending springs, each of which has a triple C shape and is arranged within the energy transfer belt.

[0083] Figure 12 shows another embodiment of an energy storage device according to the invention, comprising four bending springs, each having a triple C-shape and arranged outside the energy transfer band. Figure 13 shows another embodiment of an energy storage device according to the invention, comprising four bending springs, each having a quadruple C-shape and arranged inside the energy transfer band.

[0084] Figure 14 shows another embodiment of an energy storage device according to the invention, comprising four bending springs, each of which has a quadruple C shape and is arranged outside the energy transfer belt.

[0085] Figure 15 shows another embodiment of an energy storage device according to the invention, comprising four bending springs, each of which has a five-fold C shape and is arranged within the energy transfer belt.

[0086] Figure 16 shows another embodiment of an energy storage device according to the invention, comprising four bending springs, each of which has a five-fold C shape and is arranged outside the energy transfer band.

[0087] Figure 17 shows a further embodiment of a bending spring according to the invention comprising an S-shape or a double-C-shape, wherein the bending spring has a fabric or lay-up in the middle plane (Figure 17a), a fabric or lay-up on the outer sides (Figure 17b) or fabric or lay-up in the middle plane and on the outer sides (Figure 17c).

[0088] Figure 1 shows an isometric view (Figure 1a) and a side view (Figure 1b) of an embodiment of a bending spring 20 according to the invention, comprising an S-shape and a double-C shape, respectively. The bending spring 20 has a length L, a width B, and a thickness D. This embodiment comprises a first outer surface 21 and a second outer surface 22. The median plane 25 is located at the midpoint between the two outer surfaces 21 and 22. The median plane 25 is equidistant from the first outer surface 21 and the second outer surface 22 along its entire length L. The thickness D comprises twice this distance a. The bending spring also has two surfaces 23 and 24, which can be used as both a bearing contact surface 23 and a support contact surface 24 in a working device according to the invention.In this embodiment, the bending spring comprises a surface 23, 24 on both the first outer surface 21 and the second outer surface 22, which can be used as a bearing contact surface 23 and / or a support surface 24. In this example, the bearing contact surface 23 and the support contact surface 24 are concave. Figure 1 also shows an embodiment with four curved sections 27 and three longitudinal sections 28. The radii of curvature of the first outer surface 21 and the second outer surface 22 are clearly visible to those skilled in the art. For the sake of clarity, the radii of curvature are not marked.

[0089] Figure 2 shows an isometric view (Figure 2a) and a side view (Figure 2b) of an embodiment of a bending spring 10 according to the invention, comprising a simple C-shape. The bending spring has a length L, a width B, and a thickness D. This embodiment comprises a first outer surface 11 and a second outer surface 12. The median plane 15 is located at the midpoint between the two outer surfaces 11 and 12. The median plane 15 is equidistant from the first outer surface 11 and the second outer surface 12 along its entire length L. The thickness D comprises twice this distance a. The bending spring 10 also has two surfaces that can be used both as a bearing contact surface 13 and as a support contact surface 14 in a working device according to the invention. In this embodiment, the bending spring comprises a surface on both the first outer surface 11 and the second outer surface 12 that can be used as a bearing contact surface 13 and / or a support surface 14.In this example, the bearing contact surface 13 and the support contact surface 14 are concave. Figure 2 also shows an embodiment with three curved sections 17 and two longitudinal sections 18. The radii of curvature of the first outer surface 11 and the second outer surface 12 are clearly visible to those skilled in the art. For the sake of clarity, the radii of curvature are not marked.

[0090] Figure 3 shows an isometric view (Figure 3a) and a side view (Figure 3b) of an embodiment of a bending spring 30 according to the invention, comprising an M-shape and a triple-C-shape, respectively. The bending spring 30 has a length L, a width B, and a thickness D. This embodiment comprises a first outer surface 31 and a second outer surface 32. The median plane 35 is located at the midpoint between the two outer surfaces 31 and 32. The median plane 35 is equidistant from the first outer surface 31 and the second outer surface 32 along its entire length L. The thickness D comprises twice this distance a. The bending spring also has two surfaces which can be used both as bearing contact surfaces 33 and as support contact surfaces 34 in a working device according to the invention.In this embodiment, the bending spring comprises a surface on both the first outer surface 31 and the second outer surface 32, which can be used as a bearing contact surface 33 and / or support surface 34. In this example, the bearing contact surface 33 and the support contact surface 34 are concave. Figure 3 also shows an embodiment with five curved sections 37 and four longitudinal sections 38. The radii of curvature of the first outer surface 31 and the second outer surface 32 are clearly visible to those skilled in the art. For the sake of clarity, the radii of curvature are not marked.

[0091] Figure 4 shows an isometric view (Figure 4a) and a side view (Figure 4b) of an embodiment of a bending spring 40 according to the invention, comprising a double-S shape and a quadruple-C shape, respectively. The bending spring 40 has a length L, a width B, and a thickness D. This embodiment comprises a first outer surface 41 and a second outer surface 42. The median plane 45 is located at the midpoint between the two outer surfaces 41 and 42. The median plane 45 is equidistant from the first outer surface 41 and the second outer surface 42 along its entire length L. The thickness D comprises twice this distance a. The bending spring 40 also has two surfaces which can be used both as bearing contact surfaces 43 and as support contact surfaces 44 in a working device according to the invention.In this embodiment, the bending spring 40 comprises a surface on both the first outer surface 41 and the second outer surface 42, which can be used as a bearing contact surface 43 and / or support surface 44. In this example, the bearing contact surface 43 and the support contact surface 44 are concave. Figure 4 also shows an embodiment with six curved sections 47 and five longitudinal sections 48. The radii of curvature of the first outer surface 41 and the second outer surface 42 are clearly visible to those skilled in the art. For the sake of clarity, the radii of curvature are not marked. Figure 5 shows an isometric view (Figure 5a) and a side view (Figure 5b) of an embodiment of a bending spring 50 according to the invention, comprising a five-fold C-shape. The bending spring 50 comprises length L, width B, and thickness D. This embodiment comprises a first outer surface 51 and a second outer surface 52.The median plane 55 is located midway between the two outer surfaces 51 and 52. The median plane 55 maintains the same distance a to the first outer surface 51 and the second outer surface 52 along its entire length L. The thickness D comprises twice this distance a. The bending spring 50 also has two surfaces that can be used as both a bearing contact surface 53 and a support contact surface 54 in a working device according to the invention. In this embodiment, the bending spring 50 comprises a surface on both the first outer surface 51 and the second outer surface 52 that can be used as a bearing contact surface 53 and / or a support surface 54. In this example, the bearing contact surface 53 and / or the support contact surface 54 are concave. Figure 5 also shows an embodiment with seven curved sections 57 and six longitudinal sections 58. The radii of curvature of the first outer surface 51 and the second outer surface 52 are clearly evident to those skilled in the art.For the sake of clarity, the radii of curvature are not marked.

[0092] Figure 6 shows a first embodiment of a working device 620 according to the invention, comprising an energy transfer system 600, an electrical energy source 690 (here a battery), an electric motor (not shown here), and a trigger 610. The energy transfer system 600 comprises, for storing mechanical energy, an energy storage device with four bending springs 20, each with a double C-shape, two roller holders 62 with a total of four roller elements 66 – i.e., two roller elements 66 per roller holder 62 –, an energy transfer belt 67, a spindle 68 (shown here without threads), and an energy transfer element 69 (also called a working piston) for driving a fastening element into a substrate. In order to drive a fastening element into a substrate, electrical energy is first drawn from the electrical energy source 690 and supplied to an electric motor (not shown here).The electric motor converts electrical energy into a rotational movement, which in turn sets the spindle 68 into a translational movement. As the spindle 68 moves in the direction of the setting direction X, the roller holders 62 and thus their two roller elements 66 also move towards each other. This compresses the four bending springs 20 of the energy storage device and stores mechanical energy. The stored mechanical energy in the energy storage device is transferred to the energy transfer element 69 by actuating the trigger 610 via the energy transfer belt 67, driving a fastening element into a substrate.

[0093] Figure 7a shows an isometric view of an energy transfer system 600 according to the invention, with a section through the upper part of the energy transfer system 600 along the setting direction X by means of the section plane E. Figure 7b reveals the same embodiment as Figure 7a, comprising a top view of the energy storage system and the plane E (not shown in Figure 7b). Figures 7a and 7b show the same embodiment of the energy transfer system 600 as in the working device of Figure 6. The energy transfer system 600 reveals an energy storage device comprising four bending springs 20, each with a double C-shape. The four bending springs 20 are arranged within the energy transfer belt 67. The energy transfer system 600 also has two roller holders 62, each comprising a bearing element 63 and two roller elements 76.The top view of the section plane E (Figure 7b) shows two bending springs 20, each with a double-C shape. Both bending springs 20 are mounted on individual roller holders 62 and on a common support holder 65.

[0094] Figure 7b shows a bearing contact surface 23 for each of the two bending springs 20 and the corresponding, i.e., directly adjacent, cylindrical surface of a bearing element 63 of the roller holder 62. The bearing element 63 and the bearing contact surface 23 are contacted in such a way that relative movement between the bearing contact surface 23 of the bending spring 20 and the corresponding cylindrical surface of the bearing element 63 is possible in a circumferential direction (arrow U) of the bearing element. This relative movement occurs as soon as the energy transfer system 600 absorbs or releases mechanical energy. This is the case as soon as the bending springs 20 are compressed or relaxed. In this embodiment, the cylindrical surfaces of the bearing element 63 are convex and the bearing contact surfaces 23 of the two bending springs 20 are concave. Figure 7b shows that each of the two bending springs 20 also has a support contact surface 24.These support contact surfaces 24 of the two bending springs 20 contact the outer surface of the support element 64 such that relative movement between the support contact surfaces 24 of the bending springs 20 and the outer surface of the support element 64 is possible in a circumferential direction S (arrow S) of the support element. Thus, two bending springs 20 can be contacted and supported by one support element 64. This results in a smaller and lighter working device. In this embodiment, the outer surfaces of the support element 64 are convex and the support contact surfaces 24 of the two bending springs 20 are concave. The relative movements of the bending spring 20 with respect to the bearing contact surface 23 and the support contact surface 24 occur as soon as the energy transfer system 600 absorbs or releases mechanical energy. The support holder 65 is fixedly connected to the housing of the working device (see Figures 6a and 6b).Thus, the support bracket 65 is fixedly positioned within the housing of the working device, and its position does not change even when mechanical energy is introduced into or removed from the energy transmission system. This allows the support bracket 65 to support and / or fix the four bending springs 20 of the illustrated embodiment. This results in a smaller and lighter working device.

[0095] Figure 7c shows another isometric view of the same energy transfer system 600 according to the invention, as shown in Figures 7a and 7b. Figure 7c also shows a section through the energy transfer system 600 along the setting direction X using the plane of action W. Only the bending springs 20 are not shown in section in Figure 7c. The energy transfer system 600 discloses an energy storage device comprising four bending springs 20, each with a double-C shape. The four bending springs 20 are arranged within the energy transfer band 67. Figure 7c also shows the forces F that are transmitted from the four bending springs to the support element and the bearing elements. All resulting forces F lie in the same plane of action W. The longitudinal axis of the energy transfer element 69' is located at least partially in the plane of action W. Figure 8a shows an isometric view of another embodiment of an energy transfer system 800 according to the invention.The energy transfer system 800 discloses an energy storage device comprising four bending springs 20, each with a double C-shape. The four bending springs 20 are arranged outside the energy transfer belt 87. The energy transfer system 800 also has two roller holders 82, each comprising a bearing element (not shown) and two roller elements 86. The bending springs 20 are mounted on each roller holder 82 and on a common support holder 85. The support contact surfaces 24 (not shown) of the bending springs 20 contact the outer surface of the support element 84 such that relative movement between the support contact surfaces 24 of the bending springs 20 and the outer surface of the support element 84 is possible in a circumferential direction S (arrow S) of the support element 84. Thus, four bending springs 20 can be contacted and mounted by one support element 84. This results in a smaller and lighter device.In this embodiment, the outer surface of the support element 84 is convex, and the support contact surfaces 24 of the bending springs 20 are concave. The relative movements of the bending spring 20 with respect to the bearing contact surface 83 and the support contact surface 84 occur as soon as the energy transfer system 800 absorbs or releases mechanical energy. The support holder 85 is fixedly connected to the housing of the working device. Thus, the support holder 85 is fixedly positioned in the housing of the working device, and its position does not change even when mechanical energy is added to or removed from the energy transfer system. This allows the support holder 85 to support and / or fix the four bending springs 20 of the illustrated embodiment. This results in a smaller and lighter working device.

[0096] Figure 8b shows another isometric view of the same energy transfer system 800 according to the invention as Figure 8a. Figure 8b also shows a section through the energy transfer system 800 along the setting direction X using the plane of action W. Only the bending springs 20 are not shown in section in Figure 8b. The energy transfer system 800 discloses an energy storage device comprising four bending springs 20, each with a double-C shape. The four bending springs 20 are arranged outside the energy transfer band 87. Figure 8b also shows the forces F that are transmitted by the four bending springs to the support element and the bearing elements 82. All resultant forces F lie in the same plane of action W. The longitudinal axis of the energy transfer element 89' is located at least partially in the plane of action W.

[0097] Figure 9 shows an isometric view of another embodiment of an energy transfer system 900 according to the invention. The energy transfer system 900 discloses an energy storage device comprising four bending springs 10, each with a simple C-shape. The four bending springs 10 are arranged within the energy transfer belt 97. The energy transfer system 900 also has two roller holders 92, each comprising a bearing element (not shown) and two roller elements 96. The bending springs 10 are mounted on each roller holder 92 and on a common support holder 95.

[0098] Figure 10 shows an isometric view of another embodiment of an energy transfer system 1000 according to the invention. The energy transfer system 1000 discloses an energy storage device comprising four bending springs 10, each with a simple C-shape. The four bending springs 10 are arranged outside the energy transfer belt 107. The energy transfer system 1000 also has two roller holders 102, each comprising a bearing element (not shown) and two roller elements 106. The bending springs 10 are mounted on each roller holder 102 and on a common support holder 105.

[0099] Figure 11 shows an isometric view of another embodiment of an energy transfer system 1100 according to the invention. The energy transfer system 1100 discloses an energy storage device comprising four bending springs 30, each with a triple C-shape. The four bending springs 30 are arranged within the energy transfer belt 117. The energy transfer system 1100 also has two roller holders 112, each comprising a bearing element (not shown) and two roller elements 116. The bending springs 30 are mounted on each roller holder 112 and on a common support holder 115. Figure 12 shows an isometric view of another embodiment of an energy transfer system 1200 according to the invention. The energy transfer system 1200 discloses an energy storage device comprising four bending springs 30, each with a triple C-shape.The four bending springs 30 are arranged outside the energy transfer belt 127. The energy transfer system 1200 also has two roller holders 122, each comprising a bearing element (not shown) and two roller elements 126. The bending springs 30 are each mounted on one roller holder 122 and on a common support holder 125.

[0100] Figure 13 shows an isometric view of another embodiment of an energy transfer system 1300 according to the invention. The energy transfer system 1300 discloses an energy storage device comprising four bending springs 40, each with a quadruple C-shape. The four bending springs 40 are arranged within the energy transfer belt 137. The energy transfer system 1300 also has two roller holders 132, each comprising a bearing element (not shown) and two roller elements 136. The bending springs 40 are mounted on each roller holder 132 and on a common support holder 135.

[0101] Figure 14 shows an isometric view of another embodiment of an energy transfer system 1400 according to the invention. The energy transfer system 1400 discloses an energy storage device comprising four bending springs 40, each with a quadruple C-shape. The four bending springs 40 are arranged outside the energy transfer belt 147. The energy transfer system 1400 also has two roller holders 142, each comprising a bearing element (not shown) and two roller elements 146. The bending springs 40 are mounted on each roller holder 142 and on a common support holder 145.

[0102] Figure 15 shows an isometric view of another embodiment of an energy transfer system 1500 according to the invention. The energy transfer system 1500 discloses an energy storage device comprising four bending springs 50, each with a five-fold C-shape. The four bending springs 50 are arranged within the energy transfer belt 157. The energy transfer system 1500 also has two roller holders 152, each comprising a bearing element (not shown) and two roller elements 156. The bending springs 50 are mounted on each roller holder 152 and on a common support holder 155.

[0103] Figure 16 shows an isometric view of another embodiment of an energy transfer system 1600 according to the invention. The energy transfer system 1600 discloses an energy storage device comprising four bending springs 50, each with a five-fold C-shape. The four bending springs 50 are arranged outside the energy transfer belt 167. The energy transfer system 1600 also has two roller holders 162, each comprising a bearing element (not shown) and two roller elements 166. The bending springs 50 are mounted on each roller holder 162 and on a common support holder 165.

[0104] Figure 17 shows a further embodiment of a bending spring 170 according to the invention, comprising an S-shape or a double-C shape, wherein the bending spring 170 comprises a fabric or non-woven material 172 in the central plane (Figure 17a). The bending spring 180 comprises a fabric or non-woven material 183 on the outer sides (Figure 17b). The bending spring 190 comprises a fabric or non-woven material 173 in the central plane and a fabric or non-woven material 183 on the outer sides (Figure 17c).

Claims

Patent claims 1. Working device (620) for driving a fastening element into a substrate, comprising an energy transfer system (600), wherein the energy transfer system (600) comprises an energy storage device for storing mechanical energy in the working device (620), wherein the energy storage device comprises at least one bending spring (20) and a composite material, characterized in that the energy transfer system (600) comprises at least one roller holder (62) for storing the bending spring (20) in the working device (620), wherein the bending spring (20) comprises a bearing contact surface (23) for contacting the bending spring (20) with the roller holder (62).

2. Working device (620) according to claim 1 , characterized in that the energy storage device has an energy density of at least 500 J / kg.

3. Working device (620) according to the preceding claim, characterized in that the roller holder (62) comprises a bearing element (63) so that a relative movement between the bearing contact surface (23) of the bending spring (20) and a cylindrical surface of the bearing element (63) is possible in a circumferential direction of the bearing element (63).

4. Working device (620) according to one of the preceding claims, characterized in that the energy transmission system (600) comprises at least one support holder (65) for supporting the bending spring (20) in the working device (620), wherein the bending spring (20) comprises a support contact surface (24) for contacting the bending spring (20) with the support holder (65).

5. Working device (620) according to the preceding claim, characterized in that the support holder (65) comprises a support element (64) so ​​that a relative movement between the support contact surface (24) of the bending spring (20) and a cylindrical surface of the support element (64) is possible in a circumferential direction of the support element (64).

6. Working device (620) according to the preceding claim, characterized in that the support holder (65) is firmly connected to a housing of the working device (620), so that the support holder (65) is firmly positioned in the housing of the working device (620).

7. Working device (620) according to one of the preceding claims, characterized in that the bending spring (20) has a first outer surface (21) with a first radius of curvature and a second outer surface (22) with a second radius of curvature, wherein the bending spring (20) comprises a curvature section (27) in which the first radius of curvature and the second radius of curvature are different.

8. Working device (620) according to the preceding claim, wherein the curvature section (27) comprises the bearing contact surface (23) of the bending spring (20) and / or the support contact surface (24) of the bending spring (20).

9. Working device (620) according to one of the preceding claims characterized in that the energy transfer system (600) comprises an energy transfer belt (67) and the energy storage device comprises at least two bending springs (20).

10. Working device (620) according to the preceding claim, characterized in that the resulting forces of the at least two bending springs (20) on the roller holder (62) and / or on the support holder (65) define a plane of action W, wherein the longitudinal axis of an energy transfer element (69') is located at least partially in this plane of action W.

11. Working tool (620) for driving a fastening element into a substrate, comprising an energy transfer system (600), wherein the energy transfer system (600) comprises an energy storage device for storing mechanical energy in the working tool (620), wherein the energy storage device comprises at least a bending spring (20) and a composite material, wherein the energy transfer system (600) The energy transfer belt (67) and the energy storage device comprise at least two bending springs (20), wherein the resulting forces of the at least two bending springs (20) on the roller holder (62) and / or on the support holder (65) define a plane of action W, wherein the longitudinal axis of an energy transfer element (69') is located at least partially in this plane of action W.

12. Working device (620) according to claim 11 , characterized in that the energy storage device has an energy density of at least 500 J / kg.

13. Working device (620) according to one of claims 11 to 12, characterized in that the energy transmission system (600) comprises at least one roller holder (62) for storing the bending spring (20) in the working device (620), wherein the bending spring (20) comprises a bearing contact surface (23) for contacting the bending spring (20) with the roller holder (62).

14. Working device (620) according to claim 13, characterized in that the roller holder (62) comprises a bearing element (63) so that a relative movement between the bearing contact surface (23) of the bending spring (20) and a cylindrical surface of the bearing element (63) is possible in a circumferential direction of the bearing element (63).

15. Working device (620) according to one of claims 11 to 14, characterized in that the energy transmission system (600) comprises at least one support holder (65) for supporting the bending spring (20) in the working device (620), wherein the bending spring (20) comprises a support contact surface (24) for contacting the bending spring (20) with the support holder (65).

16. Working device (620) according to the preceding claim, characterized in that the support holder (65) comprises a support element (64) so ​​that a relative movement between the support contact surface (24) of the bending spring (20) and a cylindrical surface of the support element (64) is possible in a circumferential direction of the support element (64).

17. Working device (620) according to the preceding claim, characterized in that the support holder (65) is firmly connected to a housing of the working device (620), so that the support holder (65) is firmly positioned in the housing of the working device (620).

18. Working device (620) according to one of claims 11 to 17, characterized in that the bending spring (20) has a first outer surface (21) with a first radius of curvature and a second outer surface (22) with a second radius of curvature, wherein the bending spring (20) comprises a curvature section (27) in which the first radius of curvature and the second radius of curvature are different.

19. Working device (620) according to the preceding claim, wherein the curvature section (27) comprises the bearing contact surface (23) of the bending spring (20) and / or the support contact surface (24) of the bending spring (20).

20. Energy storage device for storing mechanical energy in a working device (620), wherein the energy storage device comprises a composite material with unidirectional fibers and a bending spring (20) with a bearing contact surface (23) and / or a support contact surface (24), wherein the unidirectional fibers are oriented in the direction of a tensile and compressive stress of the bending spring (20), characterized in that the bending spring (20) has at least one fabric layer (172) and / or one non-woven layer (172) whose fiber direction is oriented at 45° to the unidirectional fibers.

21. Energy storage device according to the preceding claim, wherein the unidirectional fibers are aligned along a circular segment in the area of ​​the bearing contact surface (23) and / or the support contact surface (24).

22. Energy storage device according to the preceding claim, characterized in that the fabric layer (183) and / or the lay-up layer (183) is arranged on an outside of the bending spring (20).

Images