A method and a device for driving a fastener into a workpiece

Abstract

A method for forcing a fastener into a workpiece by using a device (110) is disclosed, the device (110) comprising: - an air spring chamber (112); - a piston (114), wherein the piston (114) is arranged within the air spring chamber (112) in a manner that the piston (114) is moveable on a drive axis (116) from a ready position along a flight path in order to force the fastener into the workpiece; - a preload system (118), wherein the preload system (118) is configured for preloading the device (110) by forcing the piston (114) in the ready position applying a preloading force; the method comprising: a) bringing the piston (114) in the ready position by using the preload system (118) in order to preload the device (110); b) maintaining the piston (114) in the ready position by using the preload system (118) by using a retaining member; c) bringing the preload system (118) out of a flight path of the piston (114); d) releasing the piston (114) from the retaining member in order to release the preloading of the device (110) and, thereby, force the fastener into the workpiece.

Description

Technical Field

[0001] The present invention relates to a method and a device for driving a fastener into a workpiece.Background art

[0002] JP2018051715A relates to a driving machine that can change driving energy of a driving piece. The driving machine includes: a cylinder chamber for storing a gas; a driving piece moving in a first direction with pressure from the cylinder chamber to drive a fastener; a pressure accumulating chamber for storing a gas to be fed to the cylinder chamber; a flow passage through which the gas passes when being fed to the cylinder chamber from the pressure accumulating chamber; and an adjustment mechanism capable of changing flow resistance of the gas in the flow passage.

[0003] US 2020 / 282534 A1 relates to an electric nail gun including a muzzle seat, a safety component being movable relative to the muzzle seat, and a cylinder unit connected to the muzzle seat and including a striking cylinder, at least one storage chamber that is adapted for storing pressurized air, and a sealing cap that is coupled to the striking cylinder and the at least one storage chamber. The electric nail gun further includes an air valve disposed in the cylinder unit and being co-movable with the safety component from a closed position to an open position to allow the pressurized air to flow into the striking cylinder, and a nail-striking unit driven movably by the pressurized air for striking a nail when the air valve is at the open position.

[0004] US 2023 / 088831 A1 relates to a power tool including an air spring cylinder. A piston is movably positioned within the cylinder and a driver blade and a rack are attached to the piston. The power tool includes a lifter gear including a lifter gear wheel portion, and a plurality of teeth extending radially from the lifter gear wheel portion and configured to en-gage the rack. A hub includes a first end operably connected to a motor output and a sec-ond end including a hub wheel portion. A first receptacle is provided in one of the lifter gear and the hub and a first bearing element extends from the other of the lifter gear and the hub into the first receptacle. A first elastomeric damper is positioned within the first receptacle between the first bearing element and a bearing element defined portion of the first receptacle.Problem to be solved

[0005] It may be therefore desirable, preferably in view of US 2023 / 088831 A1, to provide a device and a method for driving a fastener into a workpiece that at least partially overcome the problems of the state of the art.

[0006] In particular, it may be an object of the present invention to prevent wear of the components of the device. Further in particular, it may be an object of the present invention to provide a particular robust preloading system of the device.Summary

[0007] This problem is addressed by a method and a device for driving a fastener into a workpiece with the features of the independent claims. Advantageous embodiments which might be realized in an isolated fashion or in any arbitrary combinations are listed in the dependent claims as well as throughout the specification.

[0008] In a first aspect, a method for forcing a fastener into a workpiece by using a device, preferably wherein the fastener is a nail. The device comprises: an air spring chamber, preferably wherein the air spring chamber is an air spring cylinder; a piston, wherein the piston is arranged within the air spring chamber in a manner that the piston is moveable on a drive axis from a ready position along a flight path in order to force the fastener into the workpiece; a preload system, wherein the preload system is configured for preloading the device by forcing the piston in the ready position applying a preloading force;

[0009] The term "air spring chamber" may refer to chamber configured for supporting the piston. The piston may be moveable within the air spring chamber. The air spring chamber may be configured to guide the movement of the piston. The movement of the piston may be a translational movement. The movement may be along a drive axis. The movement may be in a preload direction and / or in a fastening direction. The fastening direction may be opposite to the preload direction.

[0010] The term "preload system" may refer to an active unit configured for preloading the device by forcing the piston in the ready position. The device may comprise a driving unit configured to at least indirectly move the piston in the preload direction. The driving unit may further move the piston in the fastening direction. The driving unit may be comprised by the preload system. Thereby, the preload system may actively decrease the pressurized volume.

[0011] The steps of the method for driving a fastener into a workpiece may be performed in the given order. A different order, however, may also be feasible. Further, two or more of the method steps may be performed simultaneously. Thereby, the method steps may at least partly overlap in time. Further, the method steps may be performed once or repeatedly. Thus, one or more or even all of the method steps may be performed once or repeatedly. The method may comprise additional method steps, which are not listed herein.

[0012] The method comprises: a) bringing the piston in the ready position by using the preload system in order to preload the device; b) maintaining the piston in the ready position by using the preload system by using a retaining member; c) bringing the preload system out of a flight path of the piston; d) releasing the piston from the retaining member in order to release the preloading of the device and, thereby, force the fastener into the workpiece.

[0013] The term "retaining member" may refer to a mechanical component used to hold and / or secure a further component in place in order to prevent movement and displacement of the further component. The retaining member may be a pivot that engages in a notch or protrusion of a driver of the piston and / or the piston. The retaining member may be a circular element situated annularly around the driver or the piston. The retaining member may be released when the device detects a triggering action by the user at a time when the air flow regulating element is in the open position. The air flow regulating element may be or may be used as the retaining member. When the air flow regulating element is a closed position, the piston may remain in the ready position due to the friction between the piston and the air spring chamber. When the air flow regulating element is brought in the open position, said friction may be overcome and the piston may be released from the retaining member in order to release the preloading of the device.

[0014] The term "flight path" may refer to a trajectory through the air spring chamber that the piston takes starting from the ready position in order to force the fastener into the workpiece. The preload system may be brought out of the flight path in a manner that a collision of the preload system and the piston is avoided when the piston is released from the retaining member in order to release the preloading of the device.

[0015] By bringing the preload system out of a flight path of the piston, the piston can move indecently from the preload system. Thereby, the fastening energy may be increased and / or stabilized.

[0016] The inertial forces, specifically the preloading force, may be acting along a piston axis, specifically in contrast to typical devices. As a result, the piston design may be more simple, since the inertial force may now act only in the driving axis. This may increase safety by decreasing component stresses without increasing the mass of moving parts.

[0017] The preload system may be or may comprise at least one of: a chain configured to transmit the preloading force to the piston; a hydraulic system configured to transmit the preloading force to the piston; a lifter wheel and a lifting member, wherein the lifter wheel is configured to drive the lifting member by a rotary motion, wherein the lifting member is driven parallel to the drive axis in order to transmit the preloading force to the piston.

[0018] The term "chain" may refer to series of connected links, typically made of metal, designed to transmit motion or force, or to secure objects. The chain may be or may comprise stiffening element configured to stiffen the chain when the chain is unguided. The chain may further be guided by at least one guiding element comprised by the device in order to change a translational direction of the chain in a manner that the chain is bent. When the chain is bent, this may allow a particular compact design of the device.

[0019] The term "hydraulic system" may refer to a mechanical system using pressurized fluid to transmit the preloading force. The hydraulic system may be or may comprise a hydraulic fluid container, preferably being a high pressure reservoir, and / or an hydraulic cylinder surrounding a lifting member comprised by the piston, and / or a 4-way-valve. The fluid may be a pneumatic fluid, specifically a pneumatic incompressible fluid.

[0020] For bringing the piston in the ready position by using the preload system, the device further comprises a driving unit, wherein the driving unit is configured to move the preload system in order to bring the piston in the ready position. For bringing the preload system out of a flight path of the piston, the driving unit is configured to move the preload system in a waiting position while the retaining member maintains the piston in the ready position.

[0021] The term "waiting position" may refer to a position or configuration in which the preload system is in rest and out of the flight path of the piston. The waiting position may be a position or configuration that the preload system maintains until the fastener has been driven into the workpiece.

[0022] For bringing the preload system out of a flight path of the piston, the preload system is decoupled from the piston when the piston is in the ready position in a manner that the preload system is moveable out of the flight path independent of the piston.

[0023] The term "decoupling" may refer to the process of reversibly mechanically separating at least two components so that they are no longer attached to each other in a manner that the at least two components can move away from each other in at least one direction. When the preload system is decoupled from the piston, the preload system may move in the waiting position while the piston is maintained in the ready position. Thereby, the preload system may be moved out of the flight path of the piston. For decoupling, the preload system may comprise an active member configured to actively couple and decouple from the piston.

[0024] The device may further be configured to remove the preload system out of the flight path of the piston when piston is in the ready position. Consequently, when the preloading force is released in order to force the fastener into the workpiece, the preload system does not impact the flight of the piston, such as by colliding with the piston. This advantageously minimizes interference of both components and improves control and performance of the device.

[0025] The device further comprises a safety unit comprising a position sensor configured to monitor the position of the preload system, wherein the safety unit is configured to enable releasing the maintaining of the piston by the retaining member only when the preload system is in the waiting position. Thereby, the user safety may be increased.

[0026] The device further may comprise: a pressurized volume, wherein the pressurized volume is at least partially formed by a pressure chamber, wherein the pressurized volume decreases in a manner that the pressure within the pressurized volume increases when the piston is brought in the ready position by using the preload system in order to preload the device.

[0027] The device further may comprise: an air flow regulating element, preferably wherein the air flow regulating element is a valve, wherein the air flow regulating element is configured to seal, in a closed position of the air flow regulating element, a first chamber compartment of the pressurized volume from a second chamber compartment of the pressurized volume.

[0028] The method may comprise: e) bringing the air flow regulating element in the open position when the piston is in the ready position.

[0029] The air flow regulating element may be further configured to enable, in an open position of the air flow regulating element, an air flow from the first chamber compartment into the second chamber compartment in order to drive the movement of the piston such that the fastener is forced into the workpiece, preferably wherein said movement of the piston causes the pressurized volume to increase.

[0030] The term "pressurized volume" may refer to volume formed by at least the pressure chamber. The pressurized volume may be further formed by the air spring chamber and / or the piston. A pressure within the pressurized volume that is minimized may be, typically, larger than 4 bar.

[0031] When the air flow regulating element is in a closed position, it may separate the pressurized volume into a first chamber compartment and a second chamber compartment such that the first chamber compartment is sealed from the second chamber compartment in a manner that no air flow between the first chamber compartment and the second chamber compartment is possible. When the air flow regulating element is in the closed position, the air within the pressurized air within the second chamber compartment may apply a force onto the piston. The air within the second chamber compartment may be in contact with the piston. On the other hand, the pressurized air within the first chamber compartment may apply no force onto the piston. The air within the first chamber compartment may not be in contact with the piston. Typically, the first chamber compartment may be larger than the second chamber compartment by a factor of 5, preferable when the piston is in the ready position.

[0032] The device further may comprise: a driver that is fixedly attached to the piston, wherein the driver is forced against the fastener in a manner that the fastener is forced into a workpiece when the preloading of the device is released.

[0033] In order to the drive the movement of the piston such that the driver that is attached to the piston is forced against the fastener in a manner that the fastener is forced into a workpiece, the air within the pressurized volume may be caused to expand abruptly.

[0034] Therefore, the air flow regulating element may be brought in the open position, such that an air flow between the first chamber compartment and the second chamber compartment is possible. Thereby, the first chamber compartment may no longer form a closed volume. Rather, the air within the first chamber compartment may drive the movement of the piston by flowing through the air flow regulating element into the second chamber compartment. When the air flow regulating element is in the open position, the preloading of the device may be released by releasing the piston from the retaining member. This causes the air within the pressurized volume to expand abruptly and, thereby, move the piston. The preloading may be release by a user that presses a trigger comprised by the device. This may be called a triggering action.

[0035] The movement of the piston may cause the driver to move in the fastening direction. Thereby, a further volume may decrease, which may, typically, allow gaseous exchange with the environment, typically air. The gaseous exchange may be allowed via at least one ventilation hole within the air spring chamber.

[0036] As a result of said movement, the driver may contact the fastener at a contact surface of the driver and, thereby, drive the fastener into the workpiece. The driver may be an integral part of the piston. A cross-section of the piston in a plane orthogonal to the drive axis may be of an arbitrary shape. Preferably, the cross-section of the piston in the plane orthogonal to the drive axis may be of a circular shape.

[0037] The device may comprise a workpiece contact unit; wherein, for bringing the air flow regulating element in the open position, the workpiece contact unit is pressed against the workpiece.

[0038] The method further may comprise: f) bringing the air flow regulating element in the closed position; g) bringing the piston in an air exchange position in order to increase the second chamber compartment of the pressurized volume; h) enabling an air exchange between the environment and the second chamber compartment of the pressurized volume in order to increase the pressure within said second chamber compartment; i) stopping the air exchange of the environment and the second chamber compartment of the pressurized volume; j) bringing the piston in a loading position in order to decrease a volume of the second chamber compartment and, thereby, decrease the pressurized volume.

[0039] For bringing the piston in the "air exchange position", the piston may be moved in the fastening direction. For bringing the piston in the "loading position", the piston may be moved in the preload direction.

[0040] The method further may comprise: k) bringing the air flow regulating element in an open position such that an air flow between a first chamber compartment of the pressurized volume and a second chamber compartment of the pressurized volume is enabled.

[0041] When the air flow regulating element in an open position in step k), the pressure within the pressurized volume may increase when compared to the pressure within the pressurized volume before step f).

[0042] For bringing the piston in the air exchange position, the driving unit may move the piston when the preload system is coupled to the piston. For bringing the air flow regulating element in the closed position, the device may comprise a further driving unit configured for bringing the air flow regulating element in the closed position. For bringing the air flow regulating element in the open position, the further driving unit may be configured for bringing the air flow regulating element in the open position.

[0043] The device may comprise at least one ventilation hole in the air spring chamber for the enabling of the air exchange of the environment and the second chamber compartment of the pressurized volume. The device comprises a further air flow regulating element configured for closing the at least one ventilation hole for stopping the air exchange of the environment and the second chamber compartment of the pressurized volume. The further air flow regulating element is a sliding seal ring. A seal ring may be a particular cost efficient solution.

[0044] For enabling the air exchange of the environment and the second chamber compartment, the further air flow regulating element may be brought in an open position such that the air exchange of the environment and the second chamber compartment of the pressurized volume is enabled. For stopping the air exchange of the environment and the second chamber compartment, the further air flow regulating element may be brought in a closed position such that the air exchange of the environment and the second chamber compartment of the pressurized volume is stopped.

[0045] In a further aspect, a device for driving a fastener into a workpiece is disclosed, wherein the device is configured for performing the method.

[0046] As used in the following, the terms "have", "comprise" or "include" or any arbitrary grammatical variations thereof are used in a non-exclusive way. Thus, these terms may both refer to a situation in which, besides the feature introduced by these terms, no further features are present in the entity described in this context and to a situation in which one or more further features are present. As an example, the expressions "A has B", "A comprises B" and "A includes B" may both refer to a situation in which, besides B, no other element is present in A (i.e. a situation in which A solely and exclusively consists of B) and to a situation in which, besides B, one or more further elements are present in entity A, such as element C, elements C and D or even further elements.

[0047] Further, it shall be noted that the terms "at least one", "one or more" or similar expressions indicating that a feature or element may be present once or more than once typically will be used only once when introducing the respective feature or element. In the following, in most cases, when referring to the respective feature or element, the expressions "at least one" or "one or more" will not be repeated, non-withstanding the fact that the respective feature or element may be present once or more than once.

[0048] Further, as used in the following, the terms "preferably", "more preferably", "particularly", "more particularly", "specifically", "more specifically" or similar terms are used in conjunction with optional features, without restricting alternative possibilities. Thus, features introduced by these terms are optional features and are not intended to restrict the scope of the claims in any way. The invention may, as the skilled person will recognize, be performed by using alternative features. Similarly, features introduced by "in an embodiment of the invention" or similar expressions are intended to be optional features, without any restriction regarding alternative embodiments of the invention, without any restrictions regarding the scope of the invention and without any restriction regarding the possibility of combining the features introduced in such way with other optional or non-optional features of the invention.

[0049] Summarizing and without excluding further possible embodiments, the following embodiments may be envisaged: Embodiment 1: A method for forcing a fastener into a workpiece by using a device, preferably wherein the fastener is a nail, the device comprising: an air spring chamber, preferably wherein the air spring chamber is an air spring cylinder; a piston, wherein the piston is arranged within the air spring chamber in a manner that the piston is moveable on a drive axis from a ready position along a flight path in order to force the fastener into the workpiece; a preload system, wherein the preload system is configured for preloading the device by forcing the piston in the ready position applying a preloading force; the method comprising: a) bringing the piston in the ready position by using the preload system in order to preload the device; b) maintaining the piston in the ready position by using the preload system by using a retaining member; c) bringing the preload system out of a flight path of the piston; d) releasing the piston from the retaining member in order to release the preloading of the device and, thereby, force the fastener into the workpiece. Embodiment 2: The method according to the preceding Embodiment, wherein the preload system is or comprises at least one of: a chain configured to transmit the preloading force to the piston; a hydraulic system configured to transmit the preloading force to the piston; a lifter wheel and a lifting member, wherein the lifter wheel is configured to drive the lifting member by a rotary motion, wherein the lifting member is driven parallel to the drive axis in order to transmit the preloading force to the piston. Embodiment 3: The method according to any one of the preceding Embodiments, wherein, for bringing the piston in the ready position by using the preload system, the device further comprises a driving unit, wherein the driving unit is configured to move the preload system in order to bring the piston in the ready position. Embodiment 4: The method according to the preceding Embodiment, wherein, for bringing the preload system out of a flight path of the piston, the driving unit is configured to move the preload system in a waiting position while the retaining member maintains the piston in the ready position. Embodiment 5: The method according to any one of the preceding Embodiments, wherein, for bringing the preload system out of a flight path of the piston, the preload system is decoupled from the piston when the piston is in the ready position in a manner that the preload system is moveable out of the flight path independent of the piston. Embodiment 6: The method according to any one of the preceding Embodiments, wherein the device further comprises a safety unit comprising a position sensor configured to monitor the position of the preload system, wherein the safety unit is configured to enable releasing the maintaining of the piston by the retaining member only when the preload system is in the waiting position. Embodiment 7: The method according to any one of the preceding Embodiments, wherein the device further comprises: a driver that is fixedly attached to the piston, wherein the driver is forced against the fastener in a manner that the fastener is forced into a workpiece when the preloading of the device is released. Embodiment 8: The method according to any one of the preceding Embodiments, wherein the device further comprises: a pressurized volume, wherein the pressurized volume is at least partially formed by a pressure chamber, wherein the pressurized volume decreases in a manner that the pressure within the pressurized volume increases when the piston is brought in the ready position by using the preload system in order to preload the device. Embodiment 9: The method according to the preceding Embodiment, wherein the device further comprises: an air flow regulating element, preferably wherein the air flow regulating element is a valve, wherein the air flow regulating element is configured to seal, in a closed position of the air flow regulating element, a first chamber compartment of the pressurized volume from a second chamber compartment of the pressurized volume. wherein the method comprises: e) bringing the air flow regulating element in the open position when the piston is in the ready position. Embodiment 10: The method according to the preceding Embodiment, wherein the device comprises a workpiece contact unit; wherein, for bringing the air flow regulating element in the open position, the workpiece contact unit is pressed against the workpiece. Embodiment 11: The method according to the preceding Embodiment, wherein the method further comprises: f) bringing the air flow regulating element in the closed position; g) bringing the piston in an air exchange position in order to increase the second chamber compartment of the pressurized volume; h) enabling an air exchange between the environment and the second chamber compartment of the pressurized volume in order to increase the pressure within said second chamber compartment; i) stopping the air exchange of the environment and the second chamber compartment of the pressurized volume; j) bringing the piston in a loading position in order to decrease a volume of the second chamber compartment and, thereby, decrease the pressurized volume. Embodiment 12: The method according to the preceding Embodiment, further comprising: k) bringing the air flow regulating element in an open position such that an air flow between a first chamber compartment of the pressurized volume and a second chamber compartment of the pressurized volume is enabled. Embodiment 13: The method according to any one of the two preceding Embodiments, wherein, for bringing the piston in the air exchange position, the driving unit moves the piston when the preload system is coupled to the piston. Embodiment 14: The method according to any one of the three preceding Embodiments, wherein for bringing the air flow regulating element in the closed position, the device comprises a further driving unit configured for bringing the air flow regulating element in the closed position. Embodiment 15: The method according to the preceding Embodiment, wherein for bringing the air flow regulating element in the open position, the further driving unit is configured for bringing the air flow regulating element in the open position. Embodiment 16: The method according to any one of the five preceding Embodiments, wherein the device comprises at least one ventilation hole in the air spring chamber for the enabling of the air exchange of the environment and the second chamber compartment of the pressurized volume. Embodiment 17: The method according to the preceding Embodiment, wherein the device comprises a further air flow regulating element configured for closing the at least one ventilation hole for stopping the air exchange of the environment and the second chamber compartment of the pressurized volume. Embodiment 18: The method according to the preceding Embodiment, wherein the further air flow regulating element is a sliding seal ring. Embodiment 19: The method according to any one of the two preceding Embodiments, wherein, for enabling the air exchange of the environment and the second chamber compartment, the further air flow regulating element is brought in an open position such that the air exchange of the environment and the second chamber compartment of the pressurized volume is enabled. Embodiment 20: The method according to any one of the three preceding Embodiments, wherein, for stopping the air exchange of the environment and the second chamber compartment, the further air flow regulating element is brought in a closed position such that the air exchange of the environment and the second chamber compartment of the pressurized volume is stopped. Embodiment 21: A device for driving a fastener into a workpiece, wherein the device is configured for performing the method according to any one of the preceding Embodiments. Short description of the Figures

[0050] Further optional features and embodiments will be disclosed in more detail in the subsequent description of embodiments, preferably in conjunction with the dependent claims. Therein, the respective optional features may be realized in an isolated fashion as well as in any arbitrary feasible combination, as the skilled person will realize. The scope of the invention is not restricted by the preferred embodiments. The embodiments are schematically depicted in the Figures. Therein, identical reference numbers in these Figures refer to identical or functionally comparable elements.

[0051] In the Figures: Figure 1shows an exemplary device for driving a fastener into a workpiece; Figure 2shows the exemplary device for driving a fastener into a workpiece in a further configuration; and Figure 3shows an exemplary method for forcing a fastener into a workpiece. Detailed description of the embodiments

[0052] Figure 1 shows an exemplary device 110 for driving a fastener into a workpiece. The device 110 comprises: an air spring chamber 112, preferably wherein the air spring chamber 112 is an air spring cylinder; a piston 114, wherein the piston 114 is arranged within the air spring chamber 112 in a manner that the piston 114 is moveable on a drive axis 116 from a ready position along a flight path in order to force the fastener into the workpiece; a preload system 118, wherein the preload system 118 is configured for preloading the device 110 by forcing the piston 114 in the ready position applying a preloading force.

[0053] In Figure 1, the piston 114 is in the ready position.

[0054] The device is configured for performing an exemplary method 120 for forcing a fastener into a workpiece, illustrated in Figure 3. The method 120 comprises: a) bringing the piston 114 in the ready position (denoted by reference number 122) by using the preload system in order to preload the device; b) maintaining the piston in the ready position (denoted by reference number 124) by using a retaining member 119; c) bringing the preload system out of a flight path of the piston 114 (denoted by reference number 126); d) releasing the piston 114 (denoted by reference number 128) from the retaining member 119 in order to release the preloading of the device 110 and, thereby, force the fastener into the workpiece.

[0055] To release the piston 114 from the retaining member 119 a user may press a trigger 182 of the device 110.

[0056] The device 110 further may comprises: a pressurized volume 130, wherein the pressurized volume 120 is at least partially formed by a pressure chamber 132.

[0057] The pressurized volume 130 may decreases in a manner that the pressure within the pressurized volume 130 increases when the piston 114 is brought in the ready position by using the preload system in order to preload the device, particularly in step a).

[0058] For bringing the piston 114 in the ready position by using the preload system 118, the device 110 further may comprise a driving unit 140, wherein the driving unit is configured to move the preload system 118 in order to bring the piston 114 in the ready position.

[0059] The preload system may be or may comprise at least one of: a chain 142 configured to transmit the preloading force to the piston; a hydraulic system configured to transmit the preloading force to the piston 114; a lifter wheel and a lifting member, wherein the lifter wheel is configured to drive the lifting member by a rotary motion, wherein the lifting member is driven parallel to the drive axis 116 in order to transmit the preloading force to the piston 114.

[0060] The device 110 further may comprise: an air flow regulating element 134, preferably wherein the air flow regulating element 134 is a valve, wherein the air flow regulating element 134 is configured to seal, in a closed position of the air flow regulating element 134, a first chamber compartment 136 of the pressurized volume 130 from a second chamber compartment 138 of the pressurized volume 130.

[0061] In an open position of the air flow regulating element 134 an air flow between the first chamber compartment 136 of the pressurized volume 130 and the second chamber compartment 138 of the pressurized volume 130 may be enabled.

[0062] The method may comprise: e) bringing the air flow regulating element in the open position (denoted by reference number 146) when the piston is in the ready position, particularly during at least one of the steps b) and c).

[0063] In order to bring the air flow regulating element 124 in the respective position, the air flow regulating element 124 may be pivotable via a joint 170. In Figure 1, the air flow regulating element 134 is in the open position. In Figure 2, the air flow regulating element 134 is in the closed position.

[0064] The device further comprises: a driver 144 that is fixedly attached to the piston 114, wherein the driver 144 is forced against the fastener in a manner that the fastener is forced into a workpiece when the preloading of the device 110 is released.

[0065] The steps a) to d), particularly also including step e), may be repeated in order to drive a further fastener into the workpiece or a further workpiece.

[0066] For bringing the preload system 118 out of a flight path of the piston 114, the driving unit 140 is configured to move the preload system in a waiting position while the retaining member maintains the piston in the ready position. In Figure 2, the piston 114 is in the waiting position.

[0067] For bringing the preload system 118 out of a flight path of the piston 114, the preload system 118 may decouple from the piston 114 when the piston 114 is in the ready position in a manner that the preload system 118 is moveable out of the flight path independent of the piston 114.

[0068] The device further may comprises a safety unit 148 comprising a position sensor configured to monitor the position of the preload system 118, wherein the safety unit 148 is configured to enable releasing the maintaining of the piston 114 by the retaining member only when the preload system 118 is in the waiting position.

[0069] The device 110 may comprise a workpiece contact unit 150; wherein, for bringing the air flow regulating element 134 in the open position, the workpiece contact unit 150 is pressed against the workpiece. The device 110 may further comprise: a plunger 172; wherein the plunger 172 is configured for bringing the air flow regulating element 134 from the closed position of the air flow regulating element 134 in the open position of the air flow regulating element 134; or vice versa.

[0070] The plunger 172 may pass through a pass-through 174 in the pressure chamber 132 into the pressurized volume 130. The plunger 172 may be movably arranged within the pass-through 174. Thereby, the plunger 172 may be translationally moveable.

[0071] The workpiece contact unit 150 may be configured to move the plunger 172 for bringing the air flow regulating element 134 from the closed position of the air flow regulating element 134 in the open position of the air flow regulating element 134 when the workpiece contact unit 150 is pressed against the workpiece.

[0072] The device 110 may further comprise a stopper 177, specifically an elastic stopper, configured for stopping the piston 114, when the piston 114 is forced along the flight drive axis 116. The preload system 118 may comprise a contact member 176 that contacts the piston 114 in order to bring the piston 114 in the ready position and apply the preloading force.

[0073] The method 120 further may comprises, particularly in order to increase the pressure of the pressurized volume 130: f) bringing the air flow regulating element in the closed position(denoted by reference number 152); g) bringing the piston in an air exchange position (denoted by reference number 154) in order to increase the second chamber compartment of the pressurized volume; h) enabling an air exchange (denoted by reference number 156) between the environment and the second chamber compartment of the pressurized volume in order to increase the pressure within said second chamber compartment; i) stopping the air exchange (denoted by reference number 158) of the environment and the second chamber compartment of the pressurized volume; j) bringing the piston in a loading position (denoted by reference number 160) in order to decrease a volume of the second chamber compartment and, thereby, decrease the pressurized volume.

[0074] The method may further comprise: k) bringing the air flow regulating element in the open position (denoted by reference number 162) such that an air flow between a first chamber compartment of the pressurized volume and a second chamber compartment of the pressurized volume is enabled.

[0075] The steps f) to k) may be repeated in order to further increase the pressure of the pressurized volume 130.

[0076] For bringing the piston 114 in the air exchange position, the driving unit 140 may move the piston 114 when the preload system 118 is coupled to the piston 114.

[0077] When the preload system 118 is coupled to the piston 114 the preload system 118 may be configured to move the piston 114 along the drive axis 140 in a preload direction 178 and / or in a fastening direction 180.

[0078] For bringing the air flow regulating element 134 in the closed position, the device may comprise a further driving unit 164 configured for bringing the air flow regulating element 134 in the closed position. The further driving unit 164 may be configured for bringing the air flow regulating element 134 in the open position. The further driving unit 164 may be configured to move the plunger 172 for bringing the air flow regulating element 134 from the respective position.

[0079] The device 110 may comprise at least one ventilation hole 166 in the air spring chamber 112 for the enabling of the air exchange of the environment and the second chamber compartment 138 of the pressurized volume 130.

[0080] The device 110 may comprise a further air flow regulating element 168 configured for closing the at least one ventilation hole 166 for stopping the air exchange of the environment and the second chamber compartment 138 of the pressurized volume 130. The further air flow regulating element 168 may be a sliding seal ring. For enabling the air exchange of the environment and the second chamber compartment 138, the further air flow regulating element 168 is brought in an open position such that the air exchange of the environment and the second chamber compartment 138 of the pressurized volume 130 is enabled. For stopping the air exchange of the environment and the second chamber compartment 138, the further air flow regulating element 168 may be brought in a closed position such that the air exchange of the environment and the second chamber compartment 138 of the pressurized volume 130 is stopped. In Figure 1, the further air flow regulating element 168 is in the closed position. In Figure 2, the further air flow regulating element 168 is in the open position.List of reference numbers

[0081] 110device 112air spring chamber 114piston 116drive axis 118preload system 120method for forcing a fastener into a workpiece 122bringing the piston in the ready position 124maintaining the piston in the ready position 126bringing the preload system out of a flight path of the piston 128releasing the piston 130pressurized volume 132pressure chamber 134air flow regulating element 136first chamber compartment 138second chamber compartment 140driving unit 142chain 144driver 146bringing the air flow regulating element in the open position 148safety unit 150workpiece contact unit 152bringing the air flow regulating element in the closed position 154bringing the piston in an air exchange position 156enabling an air exchange 158stopping the air exchange 160bringing the piston in a loading position 162bringing the air flow regulating element in an open position 164further driving unit 166ventilation hole 168further air flow regulating element 170joint 172plunger 174pass-through 176stopper 177contact member 178preload direction 180fastening direction

Examples

Embodiment Construction

[0052]Figure 1 shows an exemplary device 110 for driving a fastener into a workpiece. The device 110 comprises:

an air spring chamber 112, preferably wherein the air spring chamber 112 is an air spring cylinder; a piston 114, wherein the piston 114 is arranged within the air spring chamber 112 in a manner that the piston 114 is moveable on a drive axis 116 from a ready position along a flight path in order to force the fastener into the workpiece; a preload system 118, wherein the preload system 118 is configured for preloading the device 110 by forcing the piston 114 in the ready position applying a preloading force.

[0053]In Figure 1, the piston 114 is in the ready position.

[0054]The device is configured for performing an exemplary method 120 for forcing a fastener into a workpiece, illustrated in Figure 3. The method 120 comprises:

a) bringing the piston 114 in the ready position (denoted by reference number 122) by using the preload system in order to preload the device; b) mai...

Technical Field

[0001] The present invention relates to a method and a device for driving a fastener into a workpiece.Background art

[0002] JP2018051715A relates to a driving machine that can change driving energy of a driving piece. The driving machine includes: a cylinder chamber for storing a gas; a driving piece moving in a first direction with pressure from the cylinder chamber to drive a fastener; a pressure accumulating chamber for storing a gas to be fed to the cylinder chamber; a flow passage through which the gas passes when being fed to the cylinder chamber from the pressure accumulating chamber; and an adjustment mechanism capable of changing flow resistance of the gas in the flow passage.

[0003] US 2020 / 282534 A1 relates to an electric nail gun including a muzzle seat, a safety component being movable relative to the muzzle seat, and a cylinder unit connected to the muzzle seat and including a striking cylinder, at least one storage chamber that is adapted for storing pressurized air, and a sealing cap that is coupled to the striking cylinder and the at least one storage chamber. The electric nail gun further includes an air valve disposed in the cylinder unit and being co-movable with the safety component from a closed position to an open position to allow the pressurized air to flow into the striking cylinder, and a nail-striking unit driven movably by the pressurized air for striking a nail when the air valve is at the open position.

[0004] US 2023 / 088831 A1 relates to a power tool including an air spring cylinder. A piston is movably positioned within the cylinder and a driver blade and a rack are attached to the piston. The power tool includes a lifter gear including a lifter gear wheel portion, and a plurality of teeth extending radially from the lifter gear wheel portion and configured to en-gage the rack. A hub includes a first end operably connected to a motor output and a sec-ond end including a hub wheel portion. A first receptacle is provided in one of the lifter gear and the hub and a first bearing element extends from the other of the lifter gear and the hub into the first receptacle. A first elastomeric damper is positioned within the first receptacle between the first bearing element and a bearing element defined portion of the first receptacle.Problem to be solved

[0005] It may be therefore desirable, preferably in view of US 2023 / 088831 A1, to provide a device and a method for driving a fastener into a workpiece that at least partially overcome the problems of the state of the art.

[0006] In particular, it may be an object of the present invention to prevent wear of the components of the device. Further in particular, it may be an object of the present invention to provide a particular robust preloading system of the device.Summary

[0007] This problem is addressed by a method and a device for driving a fastener into a workpiece with the features of the independent claims. Advantageous embodiments which might be realized in an isolated fashion or in any arbitrary combinations are listed in the dependent claims as well as throughout the specification.

[0008] In a first aspect, a method for forcing a fastener into a workpiece by using a device, preferably wherein the fastener is a nail. The device comprises: an air spring chamber, preferably wherein the air spring chamber is an air spring cylinder; a piston, wherein the piston is arranged within the air spring chamber in a manner that the piston is moveable on a drive axis from a ready position along a flight path in order to force the fastener into the workpiece; a preload system, wherein the preload system is configured for preloading the device by forcing the piston in the ready position applying a preloading force;

[0009] The term "air spring chamber" may refer to chamber configured for supporting the piston. The piston may be moveable within the air spring chamber. The air spring chamber may be configured to guide the movement of the piston. The movement of the piston may be a translational movement. The movement may be along a drive axis. The movement may be in a preload direction and / or in a fastening direction. The fastening direction may be opposite to the preload direction.

[0010] The term "preload system" may refer to an active unit configured for preloading the device by forcing the piston in the ready position. The device may comprise a driving unit configured to at least indirectly move the piston in the preload direction. The driving unit may further move the piston in the fastening direction. The driving unit may be comprised by the preload system. Thereby, the preload system may actively decrease the pressurized volume.

[0011] The steps of the method for driving a fastener into a workpiece may be performed in the given order. A different order, however, may also be feasible. Further, two or more of the method steps may be performed simultaneously. Thereby, the method steps may at least partly overlap in time. Further, the method steps may be performed once or repeatedly. Thus, one or more or even all of the method steps may be performed once or repeatedly. The method may comprise additional method steps, which are not listed herein.

[0012] The method comprises: a) bringing the piston in the ready position by using the preload system in order to preload the device; b) maintaining the piston in the ready position by using the preload system by using a retaining member; c) bringing the preload system out of a flight path of the piston; d) releasing the piston from the retaining member in order to release the preloading of the device and, thereby, force the fastener into the workpiece.

[0013] The term "retaining member" may refer to a mechanical component used to hold and / or secure a further component in place in order to prevent movement and displacement of the further component. The retaining member may be a pivot that engages in a notch or protrusion of a driver of the piston and / or the piston. The retaining member may be a circular element situated annularly around the driver or the piston. The retaining member may be released when the device detects a triggering action by the user at a time when the air flow regulating element is in the open position. The air flow regulating element may be or may be used as the retaining member. When the air flow regulating element is a closed position, the piston may remain in the ready position due to the friction between the piston and the air spring chamber. When the air flow regulating element is brought in the open position, said friction may be overcome and the piston may be released from the retaining member in order to release the preloading of the device.

[0014] The term "flight path" may refer to a trajectory through the air spring chamber that the piston takes starting from the ready position in order to force the fastener into the workpiece. The preload system may be brought out of the flight path in a manner that a collision of the preload system and the piston is avoided when the piston is released from the retaining member in order to release the preloading of the device.

[0015] By bringing the preload system out of a flight path of the piston, the piston can move indecently from the preload system. Thereby, the fastening energy may be increased and / or stabilized.

[0016] The inertial forces, specifically the preloading force, may be acting along a piston axis, specifically in contrast to typical devices. As a result, the piston design may be more simple, since the inertial force may now act only in the driving axis. This may increase safety by decreasing component stresses without increasing the mass of moving parts.

[0017] The preload system may be or may comprise at least one of: a chain configured to transmit the preloading force to the piston; a hydraulic system configured to transmit the preloading force to the piston; a lifter wheel and a lifting member, wherein the lifter wheel is configured to drive the lifting member by a rotary motion, wherein the lifting member is driven parallel to the drive axis in order to transmit the preloading force to the piston.

[0018] The term "chain" may refer to series of connected links, typically made of metal, designed to transmit motion or force, or to secure objects. The chain may be or may comprise stiffening element configured to stiffen the chain when the chain is unguided. The chain may further be guided by at least one guiding element comprised by the device in order to change a translational direction of the chain in a manner that the chain is bent. When the chain is bent, this may allow a particular compact design of the device.

[0019] The term "hydraulic system" may refer to a mechanical system using pressurized fluid to transmit the preloading force. The hydraulic system may be or may comprise a hydraulic fluid container, preferably being a high pressure reservoir, and / or an hydraulic cylinder surrounding a lifting member comprised by the piston, and / or a 4-way-valve. The fluid may be a pneumatic fluid, specifically a pneumatic incompressible fluid.

[0020] For bringing the piston in the ready position by using the preload system, the device further comprises a driving unit, wherein the driving unit is configured to move the preload system in order to bring the piston in the ready position. For bringing the preload system out of a flight path of the piston, the driving unit is configured to move the preload system in a waiting position while the retaining member maintains the piston in the ready position.

[0021] The term "waiting position" may refer to a position or configuration in which the preload system is in rest and out of the flight path of the piston. The waiting position may be a position or configuration that the preload system maintains until the fastener has been driven into the workpiece.

[0022] For bringing the preload system out of a flight path of the piston, the preload system is decoupled from the piston when the piston is in the ready position in a manner that the preload system is moveable out of the flight path independent of the piston.

[0023] The term "decoupling" may refer to the process of reversibly mechanically separating at least two components so that they are no longer attached to each other in a manner that the at least two components can move away from each other in at least one direction. When the preload system is decoupled from the piston, the preload system may move in the waiting position while the piston is maintained in the ready position. Thereby, the preload system may be moved out of the flight path of the piston. For decoupling, the preload system may comprise an active member configured to actively couple and decouple from the piston.

[0024] The device may further be configured to remove the preload system out of the flight path of the piston when piston is in the ready position. Consequently, when the preloading force is released in order to force the fastener into the workpiece, the preload system does not impact the flight of the piston, such as by colliding with the piston. This advantageously minimizes interference of both components and improves control and performance of the device.

[0025] The device further comprises a safety unit comprising a position sensor configured to monitor the position of the preload system, wherein the safety unit is configured to enable releasing the maintaining of the piston by the retaining member only when the preload system is in the waiting position. Thereby, the user safety may be increased.

[0026] The device further may comprise: a pressurized volume, wherein the pressurized volume is at least partially formed by a pressure chamber, wherein the pressurized volume decreases in a manner that the pressure within the pressurized volume increases when the piston is brought in the ready position by using the preload system in order to preload the device.

[0027] The device further may comprise: an air flow regulating element, preferably wherein the air flow regulating element is a valve, wherein the air flow regulating element is configured to seal, in a closed position of the air flow regulating element, a first chamber compartment of the pressurized volume from a second chamber compartment of the pressurized volume.

[0028] The method may comprise: e) bringing the air flow regulating element in the open position when the piston is in the ready position.

[0029] The air flow regulating element may be further configured to enable, in an open position of the air flow regulating element, an air flow from the first chamber compartment into the second chamber compartment in order to drive the movement of the piston such that the fastener is forced into the workpiece, preferably wherein said movement of the piston causes the pressurized volume to increase.

[0030] The term "pressurized volume" may refer to volume formed by at least the pressure chamber. The pressurized volume may be further formed by the air spring chamber and / or the piston. A pressure within the pressurized volume that is minimized may be, typically, larger than 4 bar.

[0031] When the air flow regulating element is in a closed position, it may separate the pressurized volume into a first chamber compartment and a second chamber compartment such that the first chamber compartment is sealed from the second chamber compartment in a manner that no air flow between the first chamber compartment and the second chamber compartment is possible. When the air flow regulating element is in the closed position, the air within the pressurized air within the second chamber compartment may apply a force onto the piston. The air within the second chamber compartment may be in contact with the piston. On the other hand, the pressurized air within the first chamber compartment may apply no force onto the piston. The air within the first chamber compartment may not be in contact with the piston. Typically, the first chamber compartment may be larger than the second chamber compartment by a factor of 5, preferable when the piston is in the ready position.

[0032] The device further may comprise: a driver that is fixedly attached to the piston, wherein the driver is forced against the fastener in a manner that the fastener is forced into a workpiece when the preloading of the device is released.

[0033] In order to the drive the movement of the piston such that the driver that is attached to the piston is forced against the fastener in a manner that the fastener is forced into a workpiece, the air within the pressurized volume may be caused to expand abruptly.

[0034] Therefore, the air flow regulating element may be brought in the open position, such that an air flow between the first chamber compartment and the second chamber compartment is possible. Thereby, the first chamber compartment may no longer form a closed volume. Rather, the air within the first chamber compartment may drive the movement of the piston by flowing through the air flow regulating element into the second chamber compartment. When the air flow regulating element is in the open position, the preloading of the device may be released by releasing the piston from the retaining member. This causes the air within the pressurized volume to expand abruptly and, thereby, move the piston. The preloading may be release by a user that presses a trigger comprised by the device. This may be called a triggering action.

[0035] The movement of the piston may cause the driver to move in the fastening direction. Thereby, a further volume may decrease, which may, typically, allow gaseous exchange with the environment, typically air. The gaseous exchange may be allowed via at least one ventilation hole within the air spring chamber.

[0036] As a result of said movement, the driver may contact the fastener at a contact surface of the driver and, thereby, drive the fastener into the workpiece. The driver may be an integral part of the piston. A cross-section of the piston in a plane orthogonal to the drive axis may be of an arbitrary shape. Preferably, the cross-section of the piston in the plane orthogonal to the drive axis may be of a circular shape.

[0037] The device may comprise a workpiece contact unit; wherein, for bringing the air flow regulating element in the open position, the workpiece contact unit is pressed against the workpiece.

[0038] The method further may comprise: f) bringing the air flow regulating element in the closed position; g) bringing the piston in an air exchange position in order to increase the second chamber compartment of the pressurized volume; h) enabling an air exchange between the environment and the second chamber compartment of the pressurized volume in order to increase the pressure within said second chamber compartment; i) stopping the air exchange of the environment and the second chamber compartment of the pressurized volume; j) bringing the piston in a loading position in order to decrease a volume of the second chamber compartment and, thereby, decrease the pressurized volume.

[0039] For bringing the piston in the "air exchange position", the piston may be moved in the fastening direction. For bringing the piston in the "loading position", the piston may be moved in the preload direction.

[0040] The method further may comprise: k) bringing the air flow regulating element in an open position such that an air flow between a first chamber compartment of the pressurized volume and a second chamber compartment of the pressurized volume is enabled.

[0041] When the air flow regulating element in an open position in step k), the pressure within the pressurized volume may increase when compared to the pressure within the pressurized volume before step f).

[0042] For bringing the piston in the air exchange position, the driving unit may move the piston when the preload system is coupled to the piston. For bringing the air flow regulating element in the closed position, the device may comprise a further driving unit configured for bringing the air flow regulating element in the closed position. For bringing the air flow regulating element in the open position, the further driving unit may be configured for bringing the air flow regulating element in the open position.

[0043] The device may comprise at least one ventilation hole in the air spring chamber for the enabling of the air exchange of the environment and the second chamber compartment of the pressurized volume. The device comprises a further air flow regulating element configured for closing the at least one ventilation hole for stopping the air exchange of the environment and the second chamber compartment of the pressurized volume. The further air flow regulating element is a sliding seal ring. A seal ring may be a particular cost efficient solution.

[0044] For enabling the air exchange of the environment and the second chamber compartment, the further air flow regulating element may be brought in an open position such that the air exchange of the environment and the second chamber compartment of the pressurized volume is enabled. For stopping the air exchange of the environment and the second chamber compartment, the further air flow regulating element may be brought in a closed position such that the air exchange of the environment and the second chamber compartment of the pressurized volume is stopped.

[0045] In a further aspect, a device for driving a fastener into a workpiece is disclosed, wherein the device is configured for performing the method.

[0046] As used in the following, the terms "have", "comprise" or "include" or any arbitrary grammatical variations thereof are used in a non-exclusive way. Thus, these terms may both refer to a situation in which, besides the feature introduced by these terms, no further features are present in the entity described in this context and to a situation in which one or more further features are present. As an example, the expressions "A has B", "A comprises B" and "A includes B" may both refer to a situation in which, besides B, no other element is present in A (i.e. a situation in which A solely and exclusively consists of B) and to a situation in which, besides B, one or more further elements are present in entity A, such as element C, elements C and D or even further elements.

[0047] Further, it shall be noted that the terms "at least one", "one or more" or similar expressions indicating that a feature or element may be present once or more than once typically will be used only once when introducing the respective feature or element. In the following, in most cases, when referring to the respective feature or element, the expressions "at least one" or "one or more" will not be repeated, non-withstanding the fact that the respective feature or element may be present once or more than once.

[0048] Further, as used in the following, the terms "preferably", "more preferably", "particularly", "more particularly", "specifically", "more specifically" or similar terms are used in conjunction with optional features, without restricting alternative possibilities. Thus, features introduced by these terms are optional features and are not intended to restrict the scope of the claims in any way. The invention may, as the skilled person will recognize, be performed by using alternative features. Similarly, features introduced by "in an embodiment of the invention" or similar expressions are intended to be optional features, without any restriction regarding alternative embodiments of the invention, without any restrictions regarding the scope of the invention and without any restriction regarding the possibility of combining the features introduced in such way with other optional or non-optional features of the invention.

[0049] Summarizing and without excluding further possible embodiments, the following embodiments may be envisaged: Embodiment 1: A method for forcing a fastener into a workpiece by using a device, preferably wherein the fastener is a nail, the device comprising: an air spring chamber, preferably wherein the air spring chamber is an air spring cylinder; a piston, wherein the piston is arranged within the air spring chamber in a manner that the piston is moveable on a drive axis from a ready position along a flight path in order to force the fastener into the workpiece; a preload system, wherein the preload system is configured for preloading the device by forcing the piston in the ready position applying a preloading force; the method comprising: a) bringing the piston in the ready position by using the preload system in order to preload the device; b) maintaining the piston in the ready position by using the preload system by using a retaining member; c) bringing the preload system out of a flight path of the piston; d) releasing the piston from the retaining member in order to release the preloading of the device and, thereby, force the fastener into the workpiece. Embodiment 2: The method according to the preceding Embodiment, wherein the preload system is or comprises at least one of: a chain configured to transmit the preloading force to the piston; a hydraulic system configured to transmit the preloading force to the piston; a lifter wheel and a lifting member, wherein the lifter wheel is configured to drive the lifting member by a rotary motion, wherein the lifting member is driven parallel to the drive axis in order to transmit the preloading force to the piston. Embodiment 3: The method according to any one of the preceding Embodiments, wherein, for bringing the piston in the ready position by using the preload system, the device further comprises a driving unit, wherein the driving unit is configured to move the preload system in order to bring the piston in the ready position. Embodiment 4: The method according to the preceding Embodiment, wherein, for bringing the preload system out of a flight path of the piston, the driving unit is configured to move the preload system in a waiting position while the retaining member maintains the piston in the ready position. Embodiment 5: The method according to any one of the preceding Embodiments, wherein, for bringing the preload system out of a flight path of the piston, the preload system is decoupled from the piston when the piston is in the ready position in a manner that the preload system is moveable out of the flight path independent of the piston. Embodiment 6: The method according to any one of the preceding Embodiments, wherein the device further comprises a safety unit comprising a position sensor configured to monitor the position of the preload system, wherein the safety unit is configured to enable releasing the maintaining of the piston by the retaining member only when the preload system is in the waiting position. Embodiment 7: The method according to any one of the preceding Embodiments, wherein the device further comprises: a driver that is fixedly attached to the piston, wherein the driver is forced against the fastener in a manner that the fastener is forced into a workpiece when the preloading of the device is released. Embodiment 8: The method according to any one of the preceding Embodiments, wherein the device further comprises: a pressurized volume, wherein the pressurized volume is at least partially formed by a pressure chamber, wherein the pressurized volume decreases in a manner that the pressure within the pressurized volume increases when the piston is brought in the ready position by using the preload system in order to preload the device. Embodiment 9: The method according to the preceding Embodiment, wherein the device further comprises: an air flow regulating element, preferably wherein the air flow regulating element is a valve, wherein the air flow regulating element is configured to seal, in a closed position of the air flow regulating element, a first chamber compartment of the pressurized volume from a second chamber compartment of the pressurized volume. wherein the method comprises: e) bringing the air flow regulating element in the open position when the piston is in the ready position. Embodiment 10: The method according to the preceding Embodiment, wherein the device comprises a workpiece contact unit; wherein, for bringing the air flow regulating element in the open position, the workpiece contact unit is pressed against the workpiece. Embodiment 11: The method according to the preceding Embodiment, wherein the method further comprises: f) bringing the air flow regulating element in the closed position; g) bringing the piston in an air exchange position in order to increase the second chamber compartment of the pressurized volume; h) enabling an air exchange between the environment and the second chamber compartment of the pressurized volume in order to increase the pressure within said second chamber compartment; i) stopping the air exchange of the environment and the second chamber compartment of the pressurized volume; j) bringing the piston in a loading position in order to decrease a volume of the second chamber compartment and, thereby, decrease the pressurized volume. Embodiment 12: The method according to the preceding Embodiment, further comprising: k) bringing the air flow regulating element in an open position such that an air flow between a first chamber compartment of the pressurized volume and a second chamber compartment of the pressurized volume is enabled. Embodiment 13: The method according to any one of the two preceding Embodiments, wherein, for bringing the piston in the air exchange position, the driving unit moves the piston when the preload system is coupled to the piston. Embodiment 14: The method according to any one of the three preceding Embodiments, wherein for bringing the air flow regulating element in the closed position, the device comprises a further driving unit configured for bringing the air flow regulating element in the closed position. Embodiment 15: The method according to the preceding Embodiment, wherein for bringing the air flow regulating element in the open position, the further driving unit is configured for bringing the air flow regulating element in the open position. Embodiment 16: The method according to any one of the five preceding Embodiments, wherein the device comprises at least one ventilation hole in the air spring chamber for the enabling of the air exchange of the environment and the second chamber compartment of the pressurized volume. Embodiment 17: The method according to the preceding Embodiment, wherein the device comprises a further air flow regulating element configured for closing the at least one ventilation hole for stopping the air exchange of the environment and the second chamber compartment of the pressurized volume. Embodiment 18: The method according to the preceding Embodiment, wherein the further air flow regulating element is a sliding seal ring. Embodiment 19: The method according to any one of the two preceding Embodiments, wherein, for enabling the air exchange of the environment and the second chamber compartment, the further air flow regulating element is brought in an open position such that the air exchange of the environment and the second chamber compartment of the pressurized volume is enabled. Embodiment 20: The method according to any one of the three preceding Embodiments, wherein, for stopping the air exchange of the environment and the second chamber compartment, the further air flow regulating element is brought in a closed position such that the air exchange of the environment and the second chamber compartment of the pressurized volume is stopped. Embodiment 21: A device for driving a fastener into a workpiece, wherein the device is configured for performing the method according to any one of the preceding Embodiments. Short description of the Figures

[0050] Further optional features and embodiments will be disclosed in more detail in the subsequent description of embodiments, preferably in conjunction with the dependent claims. Therein, the respective optional features may be realized in an isolated fashion as well as in any arbitrary feasible combination, as the skilled person will realize. The scope of the invention is not restricted by the preferred embodiments. The embodiments are schematically depicted in the Figures. Therein, identical reference numbers in these Figures refer to identical or functionally comparable elements.

[0051] In the Figures: Figure 1shows an exemplary device for driving a fastener into a workpiece; Figure 2shows the exemplary device for driving a fastener into a workpiece in a further configuration; and Figure 3shows an exemplary method for forcing a fastener into a workpiece. Detailed description of the embodiments

[0052] Figure 1 shows an exemplary device 110 for driving a fastener into a workpiece. The device 110 comprises: an air spring chamber 112, preferably wherein the air spring chamber 112 is an air spring cylinder; a piston 114, wherein the piston 114 is arranged within the air spring chamber 112 in a manner that the piston 114 is moveable on a drive axis 116 from a ready position along a flight path in order to force the fastener into the workpiece; a preload system 118, wherein the preload system 118 is configured for preloading the device 110 by forcing the piston 114 in the ready position applying a preloading force.

[0053] In Figure 1, the piston 114 is in the ready position.

[0054] The device is configured for performing an exemplary method 120 for forcing a fastener into a workpiece, illustrated in Figure 3. The method 120 comprises: a) bringing the piston 114 in the ready position (denoted by reference number 122) by using the preload system in order to preload the device; b) maintaining the piston in the ready position (denoted by reference number 124) by using a retaining member 119; c) bringing the preload system out of a flight path of the piston 114 (denoted by reference number 126); d) releasing the piston 114 (denoted by reference number 128) from the retaining member 119 in order to release the preloading of the device 110 and, thereby, force the fastener into the workpiece.

[0055] To release the piston 114 from the retaining member 119 a user may press a trigger 182 of the device 110.

[0056] The device 110 further may comprises: a pressurized volume 130, wherein the pressurized volume 120 is at least partially formed by a pressure chamber 132.

[0057] The pressurized volume 130 may decreases in a manner that the pressure within the pressurized volume 130 increases when the piston 114 is brought in the ready position by using the preload system in order to preload the device, particularly in step a).

[0058] For bringing the piston 114 in the ready position by using the preload system 118, the device 110 further may comprise a driving unit 140, wherein the driving unit is configured to move the preload system 118 in order to bring the piston 114 in the ready position.

[0059] The preload system may be or may comprise at least one of: a chain 142 configured to transmit the preloading force to the piston; a hydraulic system configured to transmit the preloading force to the piston 114; a lifter wheel and a lifting member, wherein the lifter wheel is configured to drive the lifting member by a rotary motion, wherein the lifting member is driven parallel to the drive axis 116 in order to transmit the preloading force to the piston 114.

[0060] The device 110 further may comprise: an air flow regulating element 134, preferably wherein the air flow regulating element 134 is a valve, wherein the air flow regulating element 134 is configured to seal, in a closed position of the air flow regulating element 134, a first chamber compartment 136 of the pressurized volume 130 from a second chamber compartment 138 of the pressurized volume 130.

[0061] In an open position of the air flow regulating element 134 an air flow between the first chamber compartment 136 of the pressurized volume 130 and the second chamber compartment 138 of the pressurized volume 130 may be enabled.

[0062] The method may comprise: e) bringing the air flow regulating element in the open position (denoted by reference number 146) when the piston is in the ready position, particularly during at least one of the steps b) and c).

[0063] In order to bring the air flow regulating element 124 in the respective position, the air flow regulating element 124 may be pivotable via a joint 170. In Figure 1, the air flow regulating element 134 is in the open position. In Figure 2, the air flow regulating element 134 is in the closed position.

[0064] The device further comprises: a driver 144 that is fixedly attached to the piston 114, wherein the driver 144 is forced against the fastener in a manner that the fastener is forced into a workpiece when the preloading of the device 110 is released.

[0065] The steps a) to d), particularly also including step e), may be repeated in order to drive a further fastener into the workpiece or a further workpiece.

[0066] For bringing the preload system 118 out of a flight path of the piston 114, the driving unit 140 is configured to move the preload system in a waiting position while the retaining member maintains the piston in the ready position. In Figure 2, the piston 114 is in the waiting position.

[0067] For bringing the preload system 118 out of a flight path of the piston 114, the preload system 118 may decouple from the piston 114 when the piston 114 is in the ready position in a manner that the preload system 118 is moveable out of the flight path independent of the piston 114.

[0068] The device further may comprises a safety unit 148 comprising a position sensor configured to monitor the position of the preload system 118, wherein the safety unit 148 is configured to enable releasing the maintaining of the piston 114 by the retaining member only when the preload system 118 is in the waiting position.

[0069] The device 110 may comprise a workpiece contact unit 150; wherein, for bringing the air flow regulating element 134 in the open position, the workpiece contact unit 150 is pressed against the workpiece. The device 110 may further comprise: a plunger 172; wherein the plunger 172 is configured for bringing the air flow regulating element 134 from the closed position of the air flow regulating element 134 in the open position of the air flow regulating element 134; or vice versa.

[0070] The plunger 172 may pass through a pass-through 174 in the pressure chamber 132 into the pressurized volume 130. The plunger 172 may be movably arranged within the pass-through 174. Thereby, the plunger 172 may be translationally moveable.

[0071] The workpiece contact unit 150 may be configured to move the plunger 172 for bringing the air flow regulating element 134 from the closed position of the air flow regulating element 134 in the open position of the air flow regulating element 134 when the workpiece contact unit 150 is pressed against the workpiece.

[0072] The device 110 may further comprise a stopper 177, specifically an elastic stopper, configured for stopping the piston 114, when the piston 114 is forced along the flight drive axis 116. The preload system 118 may comprise a contact member 176 that contacts the piston 114 in order to bring the piston 114 in the ready position and apply the preloading force.

[0073] The method 120 further may comprises, particularly in order to increase the pressure of the pressurized volume 130: f) bringing the air flow regulating element in the closed position(denoted by reference number 152); g) bringing the piston in an air exchange position (denoted by reference number 154) in order to increase the second chamber compartment of the pressurized volume; h) enabling an air exchange (denoted by reference number 156) between the environment and the second chamber compartment of the pressurized volume in order to increase the pressure within said second chamber compartment; i) stopping the air exchange (denoted by reference number 158) of the environment and the second chamber compartment of the pressurized volume; j) bringing the piston in a loading position (denoted by reference number 160) in order to decrease a volume of the second chamber compartment and, thereby, decrease the pressurized volume.

[0074] The method may further comprise: k) bringing the air flow regulating element in the open position (denoted by reference number 162) such that an air flow between a first chamber compartment of the pressurized volume and a second chamber compartment of the pressurized volume is enabled.

[0075] The steps f) to k) may be repeated in order to further increase the pressure of the pressurized volume 130.

[0076] For bringing the piston 114 in the air exchange position, the driving unit 140 may move the piston 114 when the preload system 118 is coupled to the piston 114.

[0077] When the preload system 118 is coupled to the piston 114 the preload system 118 may be configured to move the piston 114 along the drive axis 140 in a preload direction 178 and / or in a fastening direction 180.

[0078] For bringing the air flow regulating element 134 in the closed position, the device may comprise a further driving unit 164 configured for bringing the air flow regulating element 134 in the closed position. The further driving unit 164 may be configured for bringing the air flow regulating element 134 in the open position. The further driving unit 164 may be configured to move the plunger 172 for bringing the air flow regulating element 134 from the respective position.

[0079] The device 110 may comprise at least one ventilation hole 166 in the air spring chamber 112 for the enabling of the air exchange of the environment and the second chamber compartment 138 of the pressurized volume 130.

[0080] The device 110 may comprise a further air flow regulating element 168 configured for closing the at least one ventilation hole 166 for stopping the air exchange of the environment and the second chamber compartment 138 of the pressurized volume 130. The further air flow regulating element 168 may be a sliding seal ring. For enabling the air exchange of the environment and the second chamber compartment 138, the further air flow regulating element 168 is brought in an open position such that the air exchange of the environment and the second chamber compartment 138 of the pressurized volume 130 is enabled. For stopping the air exchange of the environment and the second chamber compartment 138, the further air flow regulating element 168 may be brought in a closed position such that the air exchange of the environment and the second chamber compartment 138 of the pressurized volume 130 is stopped. In Figure 1, the further air flow regulating element 168 is in the closed position. In Figure 2, the further air flow regulating element 168 is in the open position.List of reference numbers

[0081] 110device 112air spring chamber 114piston 116drive axis 118preload system 120method for forcing a fastener into a workpiece 122bringing the piston in the ready position 124maintaining the piston in the ready position 126bringing the preload system out of a flight path of the piston 128releasing the piston 130pressurized volume 132pressure chamber 134air flow regulating element 136first chamber compartment 138second chamber compartment 140driving unit 142chain 144driver 146bringing the air flow regulating element in the open position 148safety unit 150workpiece contact unit 152bringing the air flow regulating element in the closed position 154bringing the piston in an air exchange position 156enabling an air exchange 158stopping the air exchange 160bringing the piston in a loading position 162bringing the air flow regulating element in an open position 164further driving unit 166ventilation hole 168further air flow regulating element 170joint 172plunger 174pass-through 176stopper 177contact member 178preload direction 180fastening direction

Examples

Embodiment Construction

[0052]Figure 1 shows an exemplary device 110 for driving a fastener into a workpiece. The device 110 comprises:

an air spring chamber 112, preferably wherein the air spring chamber 112 is an air spring cylinder; a piston 114, wherein the piston 114 is arranged within the air spring chamber 112 in a manner that the piston 114 is moveable on a drive axis 116 from a ready position along a flight path in order to force the fastener into the workpiece; a preload system 118, wherein the preload system 118 is configured for preloading the device 110 by forcing the piston 114 in the ready position applying a preloading force.

[0053]In Figure 1, the piston 114 is in the ready position.

[0054]The device is configured for performing an exemplary method 120 for forcing a fastener into a workpiece, illustrated in Figure 3. The method 120 comprises:

a) bringing the piston 114 in the ready position (denoted by reference number 122) by using the preload system in order to preload the device; b) mai...

Claims

1. A method for forcing a fastener into a workpiece by using a device (110, the device (110) comprising: - an air spring chamber (112); - a piston (114), wherein the piston (114) is arranged within the air spring chamber (112) in a manner that the piston (114) is moveable on a drive axis (116) from a ready position along a flight path in order to force the fastener into the workpiece; - a preload system (118), wherein the preload system (118) is configured for preloading the device (110) by forcing the piston (114) in the ready position applying a preloading force; the method comprising: a) bringing the piston (114) in the ready position by using the preload system (118) in order to preload the device (110); b) maintaining the piston (114) in the ready position by using the preload system (118) by using a retaining member; c) bringing the preload system (118) out of a flight path of the piston (114); d) releasing the piston (114) from the retaining member in order to release the preloading of the device (110) and, thereby, force the fastener into the workpiece.

2. The method according to the preceding claim, wherein the preload system (118) is or comprises at least one of: - a chain (142) configured to transmit the preloading force to the piston (114); - a hydraulic system configured to transmit the preloading force to the piston (114), - a lifter wheel and a lifting member, wherein the lifter wheel is configured to drive the lifting member by a rotary motion, wherein the lifting member is driven parallel to the drive axis (116) in order to transmit the preloading force to the piston (114).

3. The method according to any one of the preceding claims, wherein, for bringing the piston (114) in the ready position by using the preload system (118), the device (110) further comprises a driving unit (140), wherein the driving unit (140) is configured to move the preload system (118) in order to bring the piston (114) in the ready position.

4. The method according to the preceding claim, wherein, for bringing the preload system (118) out of a flight path of the piston (114), the driving unit (140) is configured to move the preload system (118) in a waiting position while the retaining member maintains the piston (114) in the ready position.

5. The method according to any one of the preceding claims, wherein, for bringing the preload system (118) out of a flight path of the piston (114), the preload system (118) is decoupled from the piston (114) when the piston (114) is in the ready position in a manner that the preload system (118) is moveable out of the flight path independent of the piston (114).

6. The method according to any one of the preceding claims, wherein the device (110) further comprises - a safety unit (148) comprising a position sensor configured to monitor the position of the preload system (118), wherein the safety unit (148) is configured to enable releasing the maintaining of the piston (114) by the retaining member only when the preload system (118) is in the waiting position.

7. The method according to any one of the preceding claims, wherein the device (110) further comprises: - a driver (144) that is fixedly attached to the piston (114), wherein the driver (144) is forced against the fastener in a manner that the fastener is forced into a workpiece when the preloading of the device (110) is released.

8. The method according to any one of the preceding claims, wherein the device (110) further comprises: - a pressurized volume (130), wherein the pressurized volume (130) is at least partially formed by a pressure chamber (132), wherein the pressurized volume (130) decreases in a manner that the pressure within the pressurized volume (130) increases when the piston (114) is brought in the ready position by using the preload system (118) in order to preload the device (110).

9. The method according to the preceding claim, wherein the device (110) further comprises: - an air flow regulating element (134), wherein the air flow regulating element (134) is configured to seal, in a closed position of the air flow regulating element (134), a first chamber compartment (136) of the pressurized volume (130) from a second chamber compartment (138) of the pressurized volume (130). wherein the method comprises: e) bringing the air flow regulating element (134) in the open position when the piston (114) is in the ready position.

10. The method according to the preceding claim, wherein the device (110) comprises a workpiece contact unit (150); wherein, for bringing the air flow regulating element (134) in the open position, the workpiece contact unit (150) is pressed against the workpiece.

11. The method according to the preceding claim, wherein the method further comprises: f) bringing the air flow regulating element (134) in the closed position; g) bringing the piston (114) in an air exchange position in order to increase the second chamber compartment (138) of the pressurized volume (130); h) enabling an air exchange between the environment and the second chamber compartment (138) of the pressurized volume (130) in order to increase the pressure within said second chamber compartment (138); i) stopping the air exchange of the environment and the second chamber compartment (138) of the pressurized volume (130); j) bringing the piston (114) in a loading position in order to decrease a volume of the second chamber compartment (138) and, thereby, decrease the pressurized volume (130).

12. The method according to the preceding claim, further comprising: k) bringing the air flow regulating element (134) in the open position such that an air flow between a first chamber compartment (136) of the pressurized volume (130) and a second chamber compartment (138) of the pressurized volume (130) is enabled.

13. The method according to any one of the two preceding claims, wherein the device (110) comprises at least one ventilation hole (166) in the air spring chamber (112) for the enabling of the air exchange of the environment and the second chamber compartment (138) of the pressurized volume (130), wherein the device (110) comprises a further air flow regulating element (168) configured for closing the at least one ventilation hole (166).

14. The method according to the preceding claim, wherein, for enabling the air exchange of the environment and the second chamber compartment (138), the further air flow regulating element (168) is brought in an open position such that the air exchange of the environment and the second chamber compartment (138) of the pressurized volume (130) is enabled, wherein, for stopping the air exchange of the environment and the second chamber compartment (138), the further air flow regulating element (168) is brought in a closed position such that the air exchange of the environment and the second chamber compartment (138) of the pressurized volume (130) is stopped.

15. A device (110) for driving a fastener into a workpiece, wherein the device (110) is configured for performing the method according to any one of the preceding claims.

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