Patent Publication Number: US-8978953-B2

Title: Driving device

Description:
FIELD OF TECHNOLOGY 
     The application relates to a device for driving a fastening element into a substrate. 
     BACKGROUND OF THE INVENTION 
     Such devices typically have a piston for transferring energy to the fastening element. The energy required for this purpose must be made available within a very short time, which is why, for example, in the case of so-called spring nailers, a spring is initially set in tension and outputs the tension energy onto the piston like an impulse during the driving-in procedure for this piston to accelerate onto the fastening element. 
     In such devices, the energy with which the fastening element is driven into the substrate has an upper limit, so that the devices cannot be used universally for all fastening elements and every substrate. Therefore, it is desirable to make available driving devices that can transfer sufficient energy to a fastening element. 
     BRIEF SUMMARY OF THE INVENTION 
     According to one aspect of the application, a device for driving a fastening element into a substrate has an energy-transfer element for transferring energy to the fastening element. The energy-transfer element can move preferably between a starting position and a setting position, wherein, before the driving-in procedure, the energy-transfer element is located in the starting position and, after the driving-in procedure, in the setting position. 
     According to one aspect of the application, the device comprises a mechanical-energy storage device for storing mechanical energy. The energy-transfer element is then suitable preferably for transferring energy from the mechanical-energy storage device to the fastening element. 
     According to one aspect of the application, the device comprises an energy-transfer mechanism for transferring energy from an energy source to the mechanical-energy storage device. The energy for the driving-in procedure is preferably buffered in the mechanical-energy storage device, in order to be output like an impulse onto the fastening element. The energy-transfer mechanism is preferably suitable for transporting the energy-transfer element from the setting position into the starting position. The energy source is preferably an, in particular, electrical-energy storage device, especially preferred a battery or an accumulator. The device preferably has an energy source. 
     According to one aspect of the application, the energy-transfer mechanism is suitable for the purpose of transporting the energy-transfer element from the setting position in the direction toward the starting position without transferring energy to the mechanical-energy storage device. In this way it is made possible that the mechanical-energy storage device can hold and/or output energy, without moving the energy-transfer element into the setting position. The energy storage device thus can be discharged without a fastening element being driven from the device. 
     According to one aspect of the application, the energy-transfer mechanism is suitable for transferring energy to the mechanical-energy storage device without moving the energy-transfer element. 
     According to one aspect of the application, the energy-transfer mechanism comprises a force-transfer mechanism for transferring a force from the energy storage device to the energy-transfer element and/or for transferring a force from the energy-transfer mechanism to the mechanical-energy storage device. 
     According to one aspect of the application, the energy-transfer mechanism comprises a catch element that can be brought into engagement with the energy-transfer element for moving the energy-transfer element from the setting position into the starting position. 
     Preferably, the catch element allows a movement of the energy-transfer element from the starting position into the setting position. In particular, the catch element contacts only the energy-transfer element, so that the catch element carries along the energy-transfer element only in one of two opposing movement directions. 
     Preferably, the catch element has a longitudinal body, in particular, a rod. 
     According to one aspect of the application, the energy-transfer mechanism comprises a linear output that can move in a linear manner and comprises the catch element and is connected to the force-transfer mechanism. 
     According to one aspect of the application, the device comprises a motor with a motor output, wherein the energy-transfer mechanism comprises a movement converter for converting a rotational movement into a linear movement with a rotational drive that can be driven by the motor and the linear output and a torque-transfer mechanism for transferring a torque from the motor output to the rotational drive. 
     Preferably, the movement converter comprises a spindle drive with a spindle and a spindle nut arranged on the spindle. According to one especially preferred embodiment, the spindle forms the rotational drive, and the spindle nut forms the linear output. According to another especially preferred embodiment, the spindle nut forms the rotational drive, and the spindle forms the linear output. 
     According to one aspect of the application, the linear output is arranged locked in rotation relative to the rotational drive by means of the catch element, in that, in particular, the catch element is guided into a catch element guide. 
     According to one aspect of the application, the energy-transfer mechanism comprises a torque-transfer mechanism for transferring a torque from the motor output to the rotational drive and a force-transfer mechanism for transferring a force from the linear output to the energy storage device. 
     Preferably, the mechanical-energy storage device is provided for the purpose of storing potential energy. The mechanical-energy storage device comprises, in an especially preferred way, a spring, in particular, a coil spring. 
     Preferably, the mechanical-energy storage device is provided for the purpose of storing rotational energy. The mechanical-energy storage device comprises, in an especially preferred way, a flywheel. 
     In an especially preferred way, two ends of the spring that are, in particular, opposite each other, are movable, in order to tension the spring. 
     In an especially preferred way, the spring comprises two spring elements that are spaced apart from each other and are, in particular, mutually supported. 
     According to one aspect of the application, the energy-transfer mechanism comprises an energy-feeding mechanism for transferring energy from an energy source to the mechanical-energy storage device and a retracting mechanism that is separate from the energy-feeding mechanism and operates, in particular, independently, for transporting the energy-transfer element from the setting position into the starting position. 
     According to one aspect of the application, the device comprises a coupling mechanism for temporarily holding the energy-transfer element in the starting position. Preferably, the coupling mechanism is suitable for temporarily holding the energy-transfer element only in the starting position. 
     According to one aspect of the application, the device comprises an energy-transfer mechanism with a linear output that can move in a linear manner for transporting the energy-transfer element from the setting position into the starting position on the coupling mechanism. 
     According to one aspect of the application, the coupling mechanism is arranged on the setting axis or essentially symmetric about the setting axis. 
     According to one aspect of the application, the energy-transfer element and the linear output are arranged displaceable opposite the coupling mechanism, especially in the direction of the setting axis. 
     According to one aspect of the application, the device comprises a housing in which the energy-transfer element, the coupling mechanism and the energy-transfer mechanism are accommodated, wherein the coupling mechanism is fastened to the housing. Here it is guaranteed that, in particular, sensitive parts of the coupling mechanism are not exposed to the same acceleration forces as, for example, the energy-transfer element. 
     According to one aspect of the application, the spring comprises two spring elements that are spaced apart from each other and are supported, in particular, on opposite sides, wherein the coupling mechanism is arranged between the two spring elements spaced apart from each other. 
     According to one aspect of the application, the coupling mechanism comprises a locking element that can move perpendicular to the setting axis. Preferably, the locking element is ball-shaped. Preferably, the locking element has a metal and/or an alloy. 
     According to one aspect of the application, the coupling mechanism comprises an inner sleeve oriented along the setting axis with a recess running perpendicular to the setting axis for holding the locking element and an outer sleeve encompassing the inner sleeve with a support surface for supporting the locking element. Preferably, the support surface is inclined relative to the setting axis by an acute angle. 
     According to one aspect of the application, the linear output is arranged displaceable relative to the energy-transfer element, especially in the direction of the setting axis. 
     According to one aspect of the application, the coupling mechanism further comprises a restoring spring applying a force on the outer sleeve in the direction of the setting axis. 
     According to one aspect of the application, the device comprises a holding element, wherein, in a locked position of the holding element, the holding element holds the outer sleeve against the force of the restoring spring and wherein, in a released position of the holding element, the holding element releases a movement of the outer sleeve based on the force of the restoring spring. 
     Preferably, the energy-transfer element consists of a rigid body. 
     Preferably, the energy-transfer element has a coupling recess for receiving the locking element. 
     According to one aspect of the application, the energy-transfer element has a recess, wherein the force-transfer mechanism extends into the recess, in particular, both in the starting position of the energy-transfer element and also in the setting position of the energy-transfer element. 
     According to one aspect of the application, the recess is constructed as an opening and the force-transfer mechanism extends through the opening, in particular, both in the starting position of the energy-transfer element and also in the setting position of the energy-transfer element. 
     According to one aspect of the application, the force-transfer mechanism comprises a force diverter for diverting the direction of a force transferred by the force-transfer mechanism. Preferably, the force diverter extends into the recess or through the opening, in particular, both in the starting position of the energy-transfer element and also in the setting position of the energy-transfer element. Preferably, the force diverter is arranged movable relative to the mechanical-energy storage device and/or relative to the energy-transfer element. 
     According to one aspect of the application, the device comprises a coupling mechanism for temporarily fixing the energy-transfer element in the starting position and a tie rod for transferring a tension force from the energy-transfer mechanism, in particular, the linear output and/or the rotational drive onto the coupling mechanism. 
     According to one aspect of the application, the tie rod comprises a rotating bearing connected rigidly to the coupling mechanism and a rotating part connected rigidly to the rotational drive and supported in the rotating bearing so that it can rotate. 
     According to one aspect of the application, the force diverter comprises a belt. 
     According to one aspect of the application, the force diverter comprises a cord. 
     According to one aspect of the application, the force diverter comprises a chain. 
     According to one aspect of the application, the energy-transfer element further comprises a coupling plug-in part for temporarily coupling on a coupling mechanism. 
     According to one aspect of the application, the coupling plug-in part comprises a coupling recess for holding a locking element of the coupling mechanism. 
     According to one aspect of the application, the energy-transfer element comprises a shaft turned, in particular, toward the fastening element. Preferably, the shaft has a convexo-conical shaft section. 
     According to one aspect of the application, the recess, in particular, the opening, is arranged between the coupling plug-in part and the shaft. 
     According to one aspect of the application, the force-transfer mechanism, in particular, the force diverter, and the energy-transfer mechanism, in particular, the linear output, are mutually loaded with a force, while the energy-transfer element transfers energy to the fastening element. 
     According to one aspect of the application, the energy-transfer mechanism comprises a movement converter for converting a rotational movement into a linear movement with a rotational drive and a linear output and a force-transfer mechanism for transferring a force from the linear output to the energy storage device. 
     According to one aspect of the application, the force-transfer mechanism, in particular, the force diverter, in particular, the belt, is fastened to the energy-transfer mechanism, in particular, the linear output. 
     According to one aspect of the application, the energy-transfer mechanism, in particular, the linear output, comprises a passage, wherein the force-transfer mechanism, in particular, the force diverter, in particular, the belt, is guided through the passage and is fixed on a locking element that has, together with the force-transfer mechanism, in particular, the force diverter, in particular, the belt, an extent perpendicular to the passage that exceeds the dimensions of the passage perpendicular to the passage. Preferably, the locking element is constructed as a pin. According to another embodiment, the locking element is constructed as a ring. 
     According to one aspect of the application, the force-transfer mechanism, in particular, the force diverter, in particular, the belt, encompasses the locking element. 
     According to one aspect of the application, the force-transfer mechanism, in particular, the force diverter, in particular, the belt comprises a damping element. Preferably, the damping element is arranged between the locking element and the linear output. 
     According to one aspect of the application, the linear output comprises a damping element. 
     According to one aspect of the application, the belt comprises a plastic matrix interspersed with reinforcement fibers. Preferably, the plastic matrix comprises an elastomer. Preferably, the reinforcement fibers comprise a braid. 
     According to one aspect of the application, the belt comprises a woven fabric or non-crimp fabric of woven or non-crimp fibers. Preferably, the woven or non-crimp fibers comprise plastic fibers. 
     According to one aspect of the application, the woven fabric or non-crimp fabric comprises reinforcement fibers that differ from the woven or non-crimp fibers. 
     Preferably, the reinforcement fibers comprise glass fibers, carbon fibers, polyamide fibers, in particular, aramide fibers, metal fibers, in particular, steel fibers, ceramic fibers, basalt fibers, boron fibers, polyethylene fibers, in particular, high-performance polyethylene fibers (HPPE fibers), fibers made from liquid-crystalline polymers, in particular, polyesters, or mixtures thereof. 
     According to one aspect of the application, the device comprises a deceleration element for decelerating the energy-transfer element. Preferably, the deceleration element has a stop face for the energy-transfer element. 
     According to one aspect of the application, the device comprises a receiving element for receiving the deceleration element. Preferably, the receiving element comprises a first support wall for the axial support of the deceleration element and a second support wall for the radial support of the deceleration element. Preferably, the receiving element comprises a metal and/or an alloy. 
     According to one aspect of the application, the housing comprises a plastic and the receiving element is fastened to the drive mechanism only by means of the housing. 
     According to one aspect of the application, the housing comprises one or more first reinforcement ribs. 
     Preferably, the first reinforcement rib is suitable for transferring a force acting on the receiving element from the deceleration element onto the drive mechanism. 
     According to one aspect of the application, the deceleration element has a greater extent in the direction of the setting axis than the receiving element. 
     According to one aspect of the application, the device comprises a guide channel connecting to the receiving element for guiding the fastening element. Preferably, the guide channel is arranged displaceable on a guide rail. According to one aspect of the application, the guide channel or the guide rail is connected rigidly, in particular, monolithically, to the receiving element. 
     According to one aspect of the application, the receiving element is connected rigidly, in particular, screwed to the housing, in particular, to the first reinforcement rib. 
     According to one aspect of the application, the receiving element is supported on the housing in the setting direction. 
     According to one aspect of the application, the housing comprises a carrier element that projects into the interior of the housing, wherein the mechanical-energy storage device is fastened to the carrier element. Preferably, the carrier element comprises a flange. 
     According to one aspect of the application, the housing comprises one or more second reinforcement ribs connecting, in particular, to the carrier element. Preferably, the second reinforcement rib is connected rigidly to the carrier element, in particular, monolithically. 
     According to one aspect of the application, the housing comprises a first housing shell, a second housing shell, and a housing seal. Preferably, the housing seal seals the first housing shell relative to the second housing shell. 
     According to one aspect of the application, the first housing shell has a first material thickness and the second housing shell has a second material thickness, wherein the housing seal has a seal material thickness that differs from the first and/or second material thickness. 
     Device, wherein the first housing shell comprises a first housing material and the second housing shell comprises a second housing material, and wherein the housing seal comprises a sealing material that differs from the first and/or the second housing material. 
     According to one aspect of the application, the housing seal comprises an elastomer. 
     According to one aspect of the application, the first and/or the second housing shell has a groove in which the housing seal is arranged. 
     According to one aspect of the application, the housing seal is connected to the first and/or the second housing shell with a material fit. 
     According to one aspect of the application, the piston seal seals the guide channel relative to the energy-transfer element. 
     According to one aspect of the application, the device comprises a pressing mechanism, in particular, with a contact-pressing sensor for identifying the distance of the device to the substrate and a contact-pressing sensor seal. Preferably, the contact-pressing sensor seal seals the contact-pressing mechanism, in particular, the contact-pressing sensor, relative to the first and/or second housing shell. 
     According to one aspect of the application, the piston seal and/or the contact-pressing sensor seal has a circular-ring shape. 
     According to one aspect of the application, the piston seal and/or the contact-pressing sensor seal comprises a bellows. 
     According to one aspect of the application, the device comprises a contact element for the electrical connection of an electrical-energy storage device to the device, a first electrical line for connecting the electrical motor to the motor control mechanism, and a second electrical line for connecting the contact element to the motor control mechanism, wherein the first electrical line is longer than the second electrical line. 
     Preferably, the motor control mechanism supplies the motor with electrical power via the first electrical line in commutated phases. 
     According to one aspect of the application, the device comprises a grip for gripping the device by a user. Preferably, the housing and the control housing are arranged on opposite sides of the grip. 
     According to one aspect of the application, the housing and/or the control housing connects to the grip. 
     According to one aspect of the application, the device comprises a grip sensor for identifying a gripping and release of the grip by a user. 
     Preferably, the control mechanism is provided for the purpose of emptying the mechanical-energy storage device as soon as a release of the grip by the user is identified by means of the grip sensor. 
     According to one aspect of the application, the grip sensor comprises a switching element that sets the control mechanism into a ready mode and/or into a turned-off state as long as the grip is released and sets the control mechanism in a normal mode as long as the grip is gripped by a user. 
     The switching element is preferably a mechanical switch, in particular, a galvanic closing switch, a magnetic switch, an electronic switch, and, in particular, electronic sensor, or a non-contact proximity switch. 
     According to one aspect of the application, the grip has a gripping surface that is grasped by one hand of the user when the grip is gripped by the user, and wherein the grip sensor, in particular, the switching element, is arranged on the gripping surface. 
     According to one aspect of the application, the grip has a trigger switch for triggering the driving of the fastening element into the substrate and the grip sensor, in particular, the switching element, wherein the trigger switch is provided for actuation with the pointer finger and the grip sensor, in particular, the switching element, is provided for actuation with the middle finger, the ring finger and/or the pinky finger of the same hand as that of the pointer finger. 
     According to one aspect of the application, the grip has a trigger switch for triggering the driving of the fastening element into the substrate and wherein the trigger switch for actuation with the pointer finger and the grip sensor, in particular, the switching element, is provided for actuation with the palm and/or the heel of the same hand as that of the pointer finger. 
     According to one aspect of the application, the drive mechanism comprises a torque-transfer mechanism for transferring a torque from the motor output to the rotational drive. Preferably, the torque-transfer mechanism comprises a motor-side rotating element to a first rotational axis and a movement-converter-side rotating element with a second rotational axis offset parallel relative to the first rotational axis, wherein a rotation of the motor-side rotating element directly causes a rotation of the movement-converter-side rotating element about the first axis. Preferably, the motor-side rotating element is immovable relative to the motor output and is arranged displaceable along the first rotational axis relative to the movement-converter-side rotating element. Through the decoupling of the motor-side rotating element from the movement-converter-side rotating element, the motor-side rotating element is impact-decoupled together with the motor from the movement-converter-side rotating element together with the movement converter. 
     According to one aspect of the application, the motor-side rotating element is arranged locked in rotation relative to the motor output and is constructed, in particular, as a motor pinion. 
     According to one aspect of the application, the torque-transfer mechanism comprises one or more additional rotating elements that transfer a torque from the motor output to the motor-side rotating element, and wherein one or more rotating axes of the rotating element or the additional rotating elements are arranged offset relative to a rotational axis of the motor output and/or relative to the first rotational axis. The rotating element or the additional rotating elements are then impact-decoupled together with the motor from the movement converter. 
     According to one aspect of the application, the movement-converter-side rotating element is arranged locked in rotation relative to the rotational drive. 
     According to one aspect of the application, the torque-transfer mechanism comprises one or more additional rotating elements that transfer a torque from the movement-converter-side rotating element to the rotational drive and wherein one or more rotational axes of the rotating element or the additional rotating elements are arranged offset relative to the second rotational axis and/or relative to a rotational axis of the rotational drive. 
     According to one aspect of the application, the motor-side rotating element has motor-side teeth and the movement-converter-side rotating element has drive-element-side teeth. Preferably, the motor-side teeth and/or the drive-element-side teeth run in the direction of the first rotational axis. 
     According to one aspect of the application, the drive mechanism comprises a motor-damping element that is suitable for absorbing movement energy, in particular, vibration energy, of the motor relative to the movement converter. 
     The motor-damping element preferably comprises an elastomer. 
     According to one aspect of the application, the motor-damping element is arranged on the motor, in particular, in a ring shape around the motor. 
     According to one aspect of the application, the drive mechanism comprises a holding mechanism that is suitable for fixing the motor output relative to rotation. 
     According to one aspect of the application, the motor-damping element is arranged on the holding mechanism, in particular, in a ring shape around the holding mechanism. 
     Preferably, the motor-damping element is fastened to the motor and/or the holding mechanism, in particular, with a material fit. In an especially preferred way, the motor-damping element is vulcanized on the motor and/or the holding mechanism. 
     Preferably, the motor-damping element is arranged on the housing. In an especially preferred way, the housing has an, in particular, ring-shaped assembly element on which the motor-damping element is arranged, in particular, is fastened. In an especially preferred way, the motor-damping element is vulcanized on the assembly element. 
     According to one aspect of the application, the motor-damping element seals the motor and/or the holding mechanism relative to the housing. 
     According to one aspect of the application, the motor comprises a motor-side tension-relief element with which the first electrical line is fastened on the motor spaced apart from the electrical connection. 
     According to one aspect of the application, the housing comprises a housing-side tension-relief element with which the first electrical line is fastened to the housing. 
     According to one aspect of the application, the housing comprises a motor guide for guiding the motor in the direction of the first rotational axis. 
     According to one aspect of the application, the holding mechanism is provided to be moved on the rotating element, in particular, in the direction of the rotational axis, in order to fix the rotating element relative to rotation. 
     According to one aspect of the application, the holding mechanism can be actuated electrically. Preferably, the holding mechanism exerts a holding force on the rotating element when an electrical voltage is applied and releases the rotating element when the electrical voltage is removed, the rotating element. 
     According to one aspect of the application, the holding mechanism comprises a magnet coil. 
     According to one aspect of the application, the holding mechanism fixes the rotating element by means of a friction fit. 
     According to one aspect of the application, the holding mechanism comprises a wrap spring coupling. 
     According to one aspect of the application, the holding mechanism fixes the rotating element by means of a positive fit. 
     According to one aspect of the application, the energy-transfer mechanism comprises a motor with a motor output that is connected to the mechanical-energy storage device in an uninterruptible and force-coupled manner. A movement of the motor output causes a charging or discharging of the energy storage device and vice versa. The flow of forces between the motor output and the mechanical-energy storage device cannot be interrupted, for example, by means of a coupling. 
     According to one aspect of the application, the energy-transfer mechanism comprises a motor with a motor output that is connected to the rotational drive in an uninterruptible and torque-coupled manner. A rotation of the motor output causes a rotation of the rotational drive and vice versa. The torque flow between the motor output and the rotational drive cannot be interrupted, for example, by means of a coupling. 
     According to one aspect of the application, the device comprises a guide channel for guiding the fastening element, a contact-pressing mechanism arranged displaceable relative to the guide channel in the direction of the setting axis, in particular, with a contact-pressing sensor, for identifying the distance of the device to the substrate in the direction of the setting axis, a locking element that allows, in a released position of the locking element, a displacement of the contact-pressing mechanism and prevents, in a locked position of the locking element, a displacement of the contact-pressing mechanism and an unlocking element that can be actuated from the outside and holds, in an unlocked position of the unlocking element, the locking element in the released position of the locking element and allows, in a waiting position of the unlocking element, a movement of the locking element into the locked position. 
     According to one aspect of the application, the contact-pressing mechanism allows a transfer of energy to the fastening element only when the contact-pressing mechanism identifies a distance of the device to the substrate in the direction of the setting axis that does not exceed a specified maximum value. 
     According to one aspect of the application, the device comprises an engaging spring that moves the locking element into the locked position. 
     According to one aspect of the application, the guide channel comprises a launching section, wherein a fastening element arranged in the launching section holds the locking element in the released position, in particular, against a force of the engaging spring. Preferably, the launching section is provided for the reason that the fastening element that is designed to be driving into the substrate is located in the launching section. 
     Preferably, the guide channel, in particular, in the launching section, has a feed recess, in particular, a feed opening through which a fastening element can be fed to the guide channel. 
     According to one aspect of the application, the device comprises a feed mechanism for feeding fastening element to the guide channel. Preferably, the feed mechanism is constructed as a magazine. 
     According to one aspect of the application, the feed mechanism comprises an advancing spring that holds a fastening element arranged in the launching section in the guide channel. Preferably, the spring force of the advancing spring acting on the fastening element arranged in the launching section is greater than the spring force of the engaging spring acting on the same fastening element. 
     According to one aspect of the application, the feed mechanism comprises an advancing element loaded against the guide channel by the advancing spring. Preferably, the advancing element can be actuated from the outside by a user, in particular, displaceable, in order to bring fastening elements into the feed mechanism. 
     According to one aspect of the application, the device comprises a disengaging spring that moves the unlocking element into the waiting position. 
     Preferably, the locking element can be moved back and forth in a first direction between the released position and the locked position and wherein the unlocking element can be moved back and forth in a second direction between the unlocked position and the waiting position. 
     According to one aspect of the application, the advancing element can be moved back and forth in the first direction. 
     Preferably, the first direction is inclined relative to the second direction, in particular, at a right angle. 
     According to one aspect of the application, the locking element comprises a first displacement surface that is inclined at an acute angle relative to the first direction and faces the unlocking element. 
     According to one aspect of the application, the unlocking element comprises a second displacement surface that is inclined at an acute angle relative to the second direction and faces the locking element. 
     According to one aspect of the application, the advancing element comprises a third displacement surface that is inclined at an acute angle relative to the first direction and faces the unlocking element. 
     According to one aspect of the application, the unlocking element comprises a fourth displacement surface that is inclined at an acute angle relative to the second direction and faces the advancing element. 
     According to one aspect of the application, the unlocking element comprises a first catch element, and the advancing element comprises a second catch element, wherein the first and the second catch element engage with each other when the unlocking element is moved into the unlocked position. 
     According to one aspect of the application, the advancing element can be moved away from the guide channel from the outside by a user, in particular, can be tensioned against the advancing spring, in order to fill fastening elements into the feed mechanism. 
     According to one aspect of the application, the engagement between the unlocking element and the advancing element is detached when the advancing element is moved away from the guide channel. 
     According to one aspect of the application, in a method for using the device, the motor is operated with decreasing rotational speed against a load torque that is exerted by the mechanical-energy storage device on the motor. In particular, the load torque becomes greater the more energy is stored in the mechanical-energy storage device. 
     According to one aspect of the application, the motor is initially operated during a first time period with increasing rotational speed against the load torque and then during a second time period with constantly decreasing rotational speed against the load torque, wherein the second time period is longer than the first time period. 
     According to one aspect of the application, the largest possible load torque is greater than the largest possible motor torque that can be exerted by the motor. 
     According to one aspect of the application, the motor is supplied with decreasing energy while energy is being stored in the mechanical-energy storage device. 
     According to one aspect of the application, the rotational speed of the motor is reduced, while energy is stored in the mechanical-energy storage device. 
     According to one aspect of the application, the motor is provided to be operated with decreasing rotational speed against a load torque that is exerted by the mechanical-energy storage device on the motor. 
     According to one aspect of the application, the motor control device is suitable for supplying the motor with decreasing energy or for reducing the rotational speed of the motor while the motor is operating for storing energy in the mechanical-energy storage device. 
     According to one aspect of the application, the device comprises an intermediate energy storage device that is provided for temporarily storing energy output by the motor and for outputting it to the mechanical-energy storage device while the motor is operating for storing energy in the mechanical-energy storage device. 
     Preferably, the intermediate energy storage device is provided for storing rotational energy. In particular, the intermediate energy storage device is a flywheel. 
     According to one aspect of the application, the intermediate energy storage device, in particular, the flywheel is connected locked in rotation with the motor output. 
     According to one aspect of the application, the intermediate energy storage device, in particular, the flywheel, is accommodated in a motor housing of the motor. 
     According to one aspect of the application, the intermediate energy storage device, in particular, the flywheel, is arranged outside of a motor housing of the motor. 
     According to one aspect of the application, the deceleration element comprises a stop element made from a metal and/or an alloy with a stop face for the energy-transfer element and an impact-damping element made from an elastomer. 
     According to one aspect of the application, the mass of the impact-damping element equals at least 15%, preferably at least 20%, especially preferred at least 25%, of the mass of the impact element. In this way, an increase in the service life of the impact-damping element with simultaneous weight savings is possible. 
     According to one aspect of the application, the mass of the impact-damping element equals at least 15%, preferably at least 20%, especially preferred at least 25%, of the mass of the energy-transfer element. In this way, an increase in the service life of the impact-damping element with simultaneous weight savings is likewise possible. 
     According to one aspect of the application, a ratio of the mass of the impact-damping element to the maximum kinetic energy of the energy-transfer element equals at least 0.15 g/J, preferably at least 0.20 g/J, especially preferred at least 0.25 g/J. In this way, an increase in the service life of the impact-damping element with simultaneous weight savings is likewise possible. 
     According to one aspect of the application, the impact-damping element is connected to the stop element with a material fit, in particular, is vulcanized onto the stop element. 
     According to one aspect of the application, the elastomer comprises HNBR, NBR, NR, SBR, IIR and/or CR. 
     According to one aspect of the application, the elastomer has a Shore hardness that equals at least 50 Shore A. 
     According to one aspect of the application, the alloy comprises, in particular, a hardened steel. 
     According to one aspect of the application, the metal, in particular, the alloy, has a surface hardness that equals at least 30 HRC. 
     According to one aspect of the application, the stop face comprises a concavo-conical section. Preferably, the cone of the concavo-conical section agrees with the cone of the convexo-conical section of the energy-transfer element. 
     According to one aspect of the application, in a method, the motor is initially operated in a restoring direction in a rotational speed-regulated and essentially load-free manner and then in a tensioning direction in a current intensity-regulated manner, in order to transfer energy to the mechanical-energy storage device. 
     Preferably, the energy source is formed by an electrical-energy storage device. 
     According to one aspect of the application, a desired current intensity is defined according to specified criteria before operation of the motor in the tensioning direction. 
     Preferably, the specified criteria comprise a load state and/or a temperature of the electrical-energy storage device and/or an operating period and/or an age of the device. 
     According to one aspect of the application, the motor is provided to be operated essentially load-free in a tensioning direction against the load torque and in a restoring direction opposite the tensioning direction. Preferably, the motor control mechanism is provided for controlling the current intensities received by the motor to a specified desired current intensity for rotation of the motor in the tensioning direction and to control the rotational speed of the motor to a specified desired rotational speed when the motor rotates in the restoring direction. 
     According to one aspect of the application, the device comprises the energy source. 
     According to one aspect of the application, the energy source is formed by an electrical-energy storage device. 
     According to one aspect of the application, the motor control mechanism is suitable for determining the specified desired current intensities according to specified criteria. 
     According to one aspect of the application, the device comprises a safety mechanism through which the electrical energy source can be or is coupled with the device such that the mechanical-energy storage device is automatically relaxed when the electrical energy source is separated from the device. Preferably, the energy stored in the mechanical-energy storage device is discharged in a controlled manner. 
     According to one aspect of the application, the device comprises a holding mechanism that holds stored energy in the mechanical-energy storage device and automatically releases a discharge of the mechanical-energy storage device when the electrical energy source is separated from the device. 
     According to one aspect of the application, the safety mechanism comprises an electromechanical actuator that automatically unlocks a locking mechanism that holds stored energy in the mechanical-energy storage device when the electrical energy source is separated from the device. 
     According to one aspect of the application, the device comprises a coupling and/or braking mechanism, in order to discharge energy stored in the mechanical-energy storage device in a controlled way when the mechanical-energy storage device is discharged. 
     According to one aspect of the application, the safety mechanism comprises at least one safety switch that short-circuits phases of the electrical drive motor, in order to discharge energy stored in the mechanical-energy storage device in a controlled manner when the mechanical-energy storage device is discharged. Preferably, the safety switch is constructed as a self-governing electronic switch, in particular, as a J-FET. 
     According to one aspect of the application, the motor comprises three phases and is controlled by a 3-phase motor bridge circuit with freewheeling diodes that rectify a voltage generated during discharging of the mechanical-energy storage device. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       Below, embodiments of a device for driving a fastening element into a substrate will be explained in detail using examples with reference to the drawings. Shown are: 
         FIG. 1 , a side view of a driving device; 
         FIG. 2 , an exploded view of a housing; 
         FIG. 3 , an exploded view of a frame hook; 
         FIG. 4 , a side view of a driving device with opened housing; 
         FIG. 5 , a perspective view of an electrical-energy storage device; 
         FIG. 6 , a perspective view of an electrical-energy storage device; 
         FIG. 7 , a partial view of a driving device; 
         FIG. 8 , a partial view of a driving device; 
         FIG. 9 , a perspective view of a control mechanism with wiring; 
         FIG. 10 , a longitudinal section of an electric motor; 
         FIG. 11 , a partial view of a driving device; 
         FIG. 12   a , a perspective view of a spindle drive; 
         FIG. 12   b , a longitudinal section of a spindle drive; 
         FIG. 13 , a perspective view of a tensioning device; 
         FIG. 14 , a perspective view of a tensioning device; 
         FIG. 15 , a perspective view of a roller holder; 
         FIG. 16 , a longitudinal section of a coupling; 
         FIG. 17 , a longitudinal section of a coupled piston; 
         FIG. 18 , a perspective view of a piston; 
         FIG. 19 , a perspective view of a piston with a deceleration element; 
         FIG. 20 , a side view of a piston with a deceleration element; 
         FIG. 21 , a longitudinal section of piston with a deceleration element; 
         FIG. 22 , a side view of a deceleration element; 
         FIG. 23 , a longitudinal section of a deceleration element; 
         FIG. 24 , a partial view of a driving device; 
         FIG. 25 , a side view of a contact-pressing mechanism; 
         FIG. 26 , a partial view of a contact-pressing mechanism; 
         FIG. 27 , a partial view of a contact-pressing mechanism; 
         FIG. 28 , a partial view of a contact-pressing mechanism; 
         FIG. 29 , a partial view of a driving device; 
         FIG. 30 , a perspective view of a bolt guide; 
         FIG. 31 , a perspective view of a bolt guide; 
         FIG. 32 , a perspective view of a bolt guide; 
         FIG. 33 , a cross section of a bolt guide; 
         FIG. 34 , a cross section of a bolt guide; 
         FIG. 35 , a partial view of a driving device; 
         FIG. 36 , a partial view of a driving device; 
         FIG. 37 , a configuration schematic of a driving device; 
         FIG. 38 , a switching diagram of a driving device; 
         FIG. 39 , a state diagram of a driving device; 
         FIG. 40 , a state diagram of a driving device; 
         FIG. 41 , a state diagram of a driving device; 
         FIG. 42 , a state diagram of a driving device; 
         FIG. 43 , a longitudinal section of a driving device; 
         FIG. 44 , a longitudinal section of a driving device and 
         FIG. 45 , a longitudinal section of a driving device. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows a driving device  10  for driving a fastening element, for example, a nail or bolt, into a substrate in a side view. The driving device  10  has a not-shown energy-transfer element for transferring energy to the fastening element as well as a housing  20  in which the energy-transfer element and a similarly not-shown driving device are accommodated for transporting the energy-transfer element. 
     The driving device  10  further has a grip  30 , a magazine  40  and a bridge  50  connecting the grip  30  to the magazine  40 . The magazine is non-removable. A frame hook  60  for hanging the driving device  10  on a frame or the like and an electrical-energy storage device constructed as accumulator  590  are fastened to the bridge  50 . A trigger  34  and also a grip sensor constructed as a hand switch  35  are arranged on the grip  30 . The driving device  10  further has a guide channel  700  for guiding the fastening element and a contact-pressing mechanism  750  for identifying a distance of the driving device  10  from a not-shown substrate. An alignment of the driving device perpendicular to a substrate is supported by an alignment aid  45 . 
       FIG. 2  shows the housing  20  of the driving device  10  in an exploded view. The housing  20  has a first housing shell  27 , a second housing shell  28  and also a housing seal  29  that seals the first housing shell  27  against the second housing shell  28 , so that the interior of the housing  20  is protected from dust and the like. In a not-shown embodiment, the housing seal  29  is produced from an elastomer and is injection-molded onto the first housing shell  27 . 
     For reinforcement against impact forces during the driving of a fastening element into a substrate, the housing has reinforcement ribs  21  and second reinforcement ribs  22 . A retaining ring  26  is used for holding a not-shown deceleration element that is accommodated in the housing  20 . The retaining ring  26  is advantageously produced from plastic, in particular, injection-molded, and is part of the housing. The retaining ring  26  has a contact-pressing guide  36  for guiding a not-shown connecting rod of a contact-pressing mechanism. 
     The housing  20  further has a motor housing  24  with ventilation slots for holding a not-shown motor and a magazine  40  with a magazine rail  42 . In addition, the housing  20  has a grip  30  that comprises a first grip surface  31  and a second grip surface  32 . The two grip surfaces  31 ,  32  are advantageously films made from plastic injection-molded onto the grip  30 . A trigger  34  and also a grip sensor formed as a hand switch  35  are arranged on the grip  30 . 
       FIG. 3  shows a frame hook  60  with a spacer  62  and a retaining element  64  that has a pin  66  fastened in a bridge opening  68  of the bridge  50  of the housing. A screw sleeve  67  that is secured against loosening by a retaining spring  69  is used for fastening. The frame hook  60  is provided to be suspended with the retaining element  64  in a frame brace or the like, in order to suspend the driving device  10  on a frame or the like, for example, during working breaks. 
       FIG. 4  shows the driving device  10  with opened housing  20 . In the housing  20 , a driving mechanism  70  is accommodated for transporting an energy-transfer element covered in the drawing. The driving mechanism  70  comprises a not-shown electric motor for converting electrical energy from the accumulator  590  into rotational energy, a torque-transfer mechanism comprising a transmission  400  for transferring a torque of the electric motor to a movement converter formed as a spindle drive  300 , a force-transfer mechanism comprising a roll train  260  for transferring a force from the movement converter to a mechanical-energy storage device formed as spring  200  and for transferring a force from the spring to the energy-transfer element. 
       FIG. 5  shows the electrical-energy storage device formed as an accumulator  590  in a perspective view. The accumulator  590  has an accumulator housing  596  with a recessed grip  597  for improved gripability of the accumulator  590 . The accumulator  590  further has two retaining rails  598  with which the accumulator  590  can be inserted similar to a sled into not-shown, corresponding retaining grooves of a housing. For an electrical connection, the accumulator  590  has not-shown accumulator contacts that are arranged under a contact cover  591  protecting from splashed water. 
       FIG. 6  shows the accumulator  590  in another perspective view. On the retaining rails  598 , catch tabs  599  are provided that prevent the accumulator  590  from falling out of the housing. As soon as the accumulator  590  has been inserted into the housing, the catch tabs  599  are pushed and locked to the side against a spring force by a corresponding geometry of the grooves. Through compression of the recessed grips, the locking is detached, so that the accumulator  590  can be removed from the housing by a user with the help of the thumb and fingers of one hand. 
       FIG. 7  shows the driving device  10  with the housing  20  in a partial view. The housing  20  has a grip  30  and also a bridge  50  projecting essentially at a right angle from the grip at its end with a frame hook  60  fastened to this bridge. The housing  20  further has an accumulator receptacle  591  for holding an accumulator. The accumulator receptacle  591  is arranged on the end of the grip  30  from which the bridge projects. 
     The accumulator receptacle  591  has two retaining grooves  595  in which not-shown, corresponding retaining rails of an accumulator can be inserted. For an electrical connection of the accumulator, the accumulator receptacle  591  has several contact elements that are formed as device contacts  594  and comprise power contact elements and communications contact elements. The accumulator receptacle  591  is suitable, for example, for holding the accumulator shown in  FIGS. 5 and 6 . 
       FIG. 8  shows the driving device  10  with opened housing  20  in a partial view. In the bridge  50  of the housing  20  that connects the grip  30  to the magazine  40 , a control mechanism  500  is arranged that is accommodated in a control housing  510 . The control mechanism comprises power electronics  520  and a cooling element  530  for cooling the control mechanism, in particular, the power electronics  520 . 
     The housing  20  has an accumulator receptacle  591  with device contacts  594  for an electrical connection of a not-shown accumulator. An accumulator held in the accumulator receptacle  591  is connected electrically by means of accumulator lines  502  to the control mechanism  500  and thus provides the driving device  10  with electrical energy. 
     The housing  20  further has a communications interface  524  with a display  526  that is visible for a user of the device and an advantageously optical data interface  528  for an optical data exchange with a read-out device. 
       FIG. 9  shows the control mechanism  500  and the wiring going out from the control mechanism  500  in a driving device in a perspective view. The control mechanism  500  is held with the power electronics  520  and the cooling element  530  in the control housing  510 . The control mechanism  500  is connected by means of accumulator lines  502  to device contacts  594  for an electrical connection of a not-shown accumulator. 
     Cable strands  540  are used for the electrical connection of the control mechanism  500  to a plurality of components of the driving device, such as, for example, motors, sensors, switches, interfaces, or display elements. For example, the control mechanism  500  is connected to the contact-pressing sensor  550 , the hand switch  35 , a fan drive  560  of a fan  565  and by means of phase lines  504  and a motor retainer  485  to a not-shown electric motor that is held by the motor retainer. 
     In order to protect a contact of the phase lines  504  from damage due to movements of the motor  480 , the phase lines  504  are fixed in a motor-side tension-relieving element  494  and in a housing-side tension-relieving element hidden in the drawing, wherein the motor-side tension-relieving element is fastened directly or indirectly to the motor retainer  485  and the housing-side tensioning-relieving element is fastened directly or indirectly to a not-shown housing of the driving device, in particular, a motor housing of the motor. 
     The motor, the motor retainer  485 , the tension-relieving elements  494 , the fan  565  and the fan drive  560  are accommodated in the motor housing  24  from  FIG. 2 . The motor housing  24  is sealed, in particular, against dust, relative to the rest of the housing by means of the line seal  570 . 
     Because the control mechanism  500  is arranged on the same side of the not-shown grip as the device contacts  594 , the accumulator lines  502  are shorter than the phase lines  504  running through the grip. Because the accumulator lines transport a greater current intensity and have a greater cross section than the phase lines, shortening of the accumulator lines at the cost of lengthening the phase lines is advantageous overall. 
       FIG. 10  shows an electrical motor  480  with a motor output  490  in a longitudinal section. The motor  480  is constructed as a brush-less direct-current motor and has motor coils  495  for driving the motor output  490  that comprises a permanent magnet  491 . The motor  480  is held by a not-shown motor retainer and supplied with electrical energy by means of crimp contacts  506  and controlled by means of the control line  505 . 
     On the motor output  490 , a motor-side rotating element constructed as a motor pinion  410  is fastened locked in rotation by a press fit. The motor pinion  410  is driven by the motor output  490  and drives, on its side, a not-shown torque-transfer mechanism. A retaining mechanism  450  is supported, on one hand, by means of a bearing  452  on the motor output  490  so that it can rotate and is attached, on the other hand, locked in rotation by means of a ring-shaped assembly element  470  on the motor housing. Between the retaining mechanism  450  and the assembly element  470 , there is a similarly ring-shaped motor damping element  460  that is used for damping relative movements between the motor  480  and the motor housing. 
     Advantageously, the motor damping element  460  is used alternatively or simultaneously with respect to the seal against dust and the like. Together with the line seal  570 , the motor housing  24  is sealed relative to the rest of the housing, wherein the fan  565  draws air for cooling the motor  480  through the ventilation slots  33  and the rest of the drive mechanism is protected from dust. 
     The retaining mechanism  450  has a magnetic coil  455  that exerts a force of attraction on one or more magnetic armatures  456  when energized. The magnetic armatures  456  extend into armature recesses  457  of the motor pinion  410  formed as openings and are thus arranged locked in rotation on the motor pinion  410  and thus on the motor output  490 . Due to the force of attraction, the magnetic armatures  456  are pressed against the retaining mechanism  450 , so that a rotational movement of the motor output  490  is braked or prevented relative to the motor housing. 
       FIG. 11  shows the driving device  10  in another partial view. The housing  20  has the grip  30  and the motor housing  24 . In the motor housing  24  shown only partially, the motor  480  is accommodated with the motor retainer  485 . The motor pinion  410  with the armature recess  457  and the retaining mechanism  450  sits on the not-shown motor output of the motor  480 . 
     The motor pinion  410  drives gearwheels  420 ,  430  of a torque-transfer mechanism formed as transmission  400 . The transmission  400  transfers a torque of the motor  480  to a spindle gear  440  that is connected locked in rotation with a rotational drive formed as spindle  310  of a movement converter not shown in more detail. The transmission  400  has a step-down gear ratio, so that a greater torque is exerted on the spindle  310  than on the motor output  490 . 
     In order to protect the motor  480  from large accelerations that occur in the driving device  10 , especially in the housing  20 , during a driving procedure, the motor  480  is decoupled from the housing  20  and the spindle drive. Because a rotational axis  390  of the motor  480  is oriented parallel to a setting axis  380  of the driving device  10 , a decoupling of the motor  480  in the direction of the rotational axis  390  is desirable. This is implemented in that the motor pinion  410  and the gearwheel  420  driven directly by the motor pinion  410  are arranged displaceable relative to each other in the direction of the setting axis  380  and the rotational axis  390 . 
     The motor  480  is thus fastened to the housing-fixed assembly element  470  and thus to the housing  20  only by means of the motor damping element  460 . The assembly element  470  is held secured against twisting by means of a notch  475  in corresponding counter contours of the housing  20 . In addition, the motor is supported displaceable only in the direction of its rotational axis  390 , namely by means of the motor pinion  410  on the gearwheel  420  and by means of a guide element  488  of the motor retainer  485  on a correspondingly shaped, not-shown motor guide of the motor housing  24 . 
       FIG. 12   a  shows a movement converter formed as a spindle drive  300  in a perspective view. The spindle drive  300  has a rotational drive formed as a spindle  310  and also a linear output formed as a spindle nut  320 . A not-shown internal thread of the spindle nut  320  here engages with an external thread  312  of the spindle. 
     If the spindle  310  is now driven to rotate by means of the spindle gear  440  fastened locked in rotation on the spindle  310 , then the spindle nut  320  moves along the spindle  310  in a linear motion. The rotational movement of the spindle  310  is thus converted into a linear movement of the spindle nut  320 . In order to prevent rotation of the spindle nut  320  with the spindle  310 , the spindle  320  has a twisting securing device in the form of catch elements  330  fastened on the spindle nut  320 . For this purpose, the catch elements  330  are guided in not-shown guide slots of a housing or a housing-fixed component of the driving device. 
     The catch elements  330  are further constructed as retaining rods for retracting a not-shown piston into its starting position and have barbed hooks  340  that engage in corresponding retaining pins of the piston. A slot-shaped magnet receptacle  350  is used for holding a not-shown magnet armature to which a not-shown spindle sensor responds, in order to detect a position of the spindle nut  320  on the spindle  310 . 
       FIG. 12   b  shows the spindle drive  300  with the spindle  310  and the spindle nut  320  in a partial longitudinal section. The spindle nut has an internal thread  328  that engages with the external thread  312  of the spindle. 
     A force diverter of a force-transfer mechanism formed as belt  270  for transferring a force from the spindle nut  320  to a not-shown mechanical-energy storage device is fastened to the spindle nut  320 . For this purpose, the spindle nut  320  has, in addition to an internally threaded sleeve  370 , an external clamping sleeve  375 , wherein a peripheral gap between the threaded sleeve  370  and the clamping sleeve  375  forms a passage  322 . The belt  270  is guided through the passage  322  and fixed on a locking element  324 , in that the belt  270  surrounds the locking element  324  and is led back through the passage  322  again, where a belt end  275  is sewn with the belt  270 . Advantageously, the locking element has a peripheral form just like the passage  322  as a locking ring. 
     Perpendicular to the passage  322 , that is, in the radial direction with respect to a spindle axis  311 , the locking element  324  has, together with the formed belt loop  278 , a larger width than the passage  322 . Thus, the locking element  324  cannot slip through the passage  322  with the belt loop  278 , so that the belt  270  is fastened to the spindle nut  320 . 
     Through the fastening of the belt  270  to the spindle nut  320 , it is guaranteed that a tensioning force of the not-shown mechanical-energy storage device that is constructed, in particular, as a spring, is diverted by the belt  270  and transferred directly to the spindle sleeve  320 . The tensioning force is transferred from the spindle nut  320  via the spindle  310  and a tie rod  360  to a not-shown coupling mechanism that holds a similarly not-shown, coupled piston. The tie rod has a spindle arbor  365  that is connected rigidly on one side to the spindle  310  and is supported on the other side in a spindle bearing  315  so that it can rotate. 
     Because the tensioning force is also exerted on the piston, but in the opposite direction, the tensile forces exerted on the tie rod  360  are essentially canceled, so that tension is relieved from a not-shown housing on which the tie rod  360  is supported, in particular, fastened. The belt  270  and the spindle nut  320  are loaded mutually with the tensioning force, while the piston is to be accelerated onto a not-shown fastening element. 
       FIG. 13  shows a force-transfer mechanism formed as roll train  260  for transferring a force to a spring  200  in a perspective view. The roll train  260  has a force diverter formed by a belt  270  and also a front roll holder  281  with front rolls  291  and a rear roll holder  282  with rear rolls  292 . The roll holders  281 ,  282  are advantageously made from, in particular, a fiber-reinforced plastic. The roll holders  281 ,  282  have guide rails  285  for a guide of the roll holders  281 ,  282  in a not-shown housing of the driving device, in particular, in grooves of the housing. 
     The belt engages with the spindle nut and also a piston  100  and is placed above the rolls  291 ,  292 , so that the roll train  260  is formed. The piston  100  is coupled in a not-shown coupling mechanism. The roll train causes a step-up transmission of a speed of the spring ends  230 ,  240  into a speed of the piston  100  by a factor of two. 
     Furthermore, a spring  200  is shown that comprises a front spring element  210  and a rear spring element  220 . The front spring end  230  of the front spring element  210  is held in the front roll holder  281 , while the rear spring end  240  of the rear spring element  220  is held in the rear roll holder. The spring elements  210 ,  220  are supported on support rings  250  on their facing sides. Through the symmetric arrangement of the spring elements  210 ,  220 , recoil forces of the spring elements  210 ,  220  are canceled out, so that the operating comfort of the driving device is improved. 
     Furthermore, a spindle drive  300  is shown with a spindle gear  440 , a spindle  310 , and a spindle nut arranged within the rear spring element  220 , wherein a catch element  330  fastened to the spindle nut is to be seen. 
       FIG. 14  shows the roll train  260  in a tensioned state of the spring  200 . The spindle nut  320  is now located on the coupling-side end of the spindle  310  and pulls the belt  270  into the rear spring element. Therefore, the roll holders  281 ,  282  are moved toward each other, and the spring elements  210 ,  220  are tensioned. The piston  100  is here held by the coupling mechanism  150  against the spring force of the spring elements  210 ,  220 . 
       FIG. 15  shows a spring  200  in a perspective view. The spring  200  is constructed as a coil spring and is made from steel. One end of the spring  200  is held in a roll holder  280 ; the other end of the spring  200  is fastened to a support ring  250 . The roll holder  280  has rolls  290  that project from the roll holder  280  on the side of the roll holder  280  facing away from the spring  200 . The rolls are supported so that they can rotate about axes that are parallel to each other and allow a not-shown belt to be pulled into the interior of the spring  200 . 
       FIG. 16  shows a coupling mechanism  150  for a temporary fixing of an energy-transfer element, in particular, a piston, in a longitudinal section. Furthermore, the tie rod  360  is shown with the spindle bearing  315  and the spindle arbor  365 . 
     The coupling mechanism  150  has an inner sleeve  170  and an outer sleeve  180  displaceable relative to the inner sleeve  170 . The inner sleeve  170  is provided with recesses  175  constructed as openings, wherein locking elements constructed as balls  160  are arranged in the recesses  175 . In order to prevent the balls  160  from falling out into an interior of the inner sleeve  170 , the recesses  175  taper inward, in particular, in a conical shape, to a cross section through which the balls  160  cannot pass. In order to be able to lock the coupling mechanism  150  with the help of the balls  160 , the outer sleeve  180  has a support surface  185  on which the balls  160  are supported on the outside in a locked state of the coupling mechanism  150 , as shown in  FIG. 16 . 
     In the locked state, the balls  160  therefore project into the interior of the inner sleeve and hold the piston in the coupling. A retaining element constructed as pawl  800  here holds the outer sleeve in the illustrated position against the spring force of a restoring spring  190 . The pawl is here biased by a pawl spring  810  against the outer sleeve  180  and engages behind a coupling pin projecting from the outer sleeve  180 . 
     For releasing the coupling mechanism  150 , for example, by the actuation of a trigger, the pawl  800  is moved away from the outer sleeve  180  against the spring force of the pawl spring  810 , so that the outer sleeve  180  is moved toward the left in the drawing by the restoring spring  190 . On its inside, the outer sleeve  180  has recesses  182  that can then hold the balls  160  sliding along the inclined support surfaces into the recesses  182  and releasing the interior of the inner sleeve. 
       FIG. 17  shows another longitudinal section of the coupling mechanism  150  with coupled piston  100 . For this purpose, the piston has a coupling plug-in part  110  with coupling recesses  120  in which the balls  160  of the coupling mechanism  150  can engage. Furthermore, the piston  100  has a shoulder  125  and also a belt passage  130  and a convexo-conical section  135 . The balls  160  are advantageously made from hardened steel. 
     A coupling of the piston  100  in the coupling mechanism  150  begins in an unlocked state of the coupling mechanism  150  in which the outer sleeve  180  loaded by the restoring spring  190  allows a holding of the balls  160  in the recesses  182 . The piston  100  can therefore displace the balls  160  outward when the piston  100  is inserted into the inner sleeve  170 . With the help of the shoulder  125 , the piston  100  then pushes the outer sleeve  180  against the force of the restoring spring  190 . As soon as the pawl  800  engages with the coupling pin  195 , the coupling mechanism  150  is held in the locked state. 
     The piston  100  comprises a shaft  140  and a head  142 , wherein the shaft  140  and the head  142  are advantageously soldered to each other. A positive fit in the form of a shoulder  144  prevents the shaft  140  from sliding out from the head  142  in the case of rupture of the solder connection  146 . 
       FIG. 18  shows an energy-transfer mechanism constructed as piston  100  in a perspective view. The piston has a shaft  140 , a convexo-conical section  135 , and a recess constructed as belt passage  130 . The belt passage  130  is constructed as an elongated hole and has, for gentle treatment of the belt, only rounded edges and heat-treated surfaces. A coupling plug-in part  110  with coupling recesses  120  connects to the belt passage. 
       FIG. 19  shows the piston  100  together with a deceleration element  600  in a perspective view. The piston has a shaft  140 , a convexo-conical section  135 , and a recess constructed as belt passage  130 . A coupling plug-in part  110  with coupling recesses  120  connects to the belt passage. Furthermore, the piston  100  has several retaining pins  145  for engaging not-shown catch elements, for example, belonging to a spindle nut. 
     The deceleration element  600  has a stop surface  620  for the convexo-conical section  135  of the piston  100  and is held in a not-shown receptacle element. The deceleration element  600  is held in the receptacle element by a not-shown retaining ring, wherein the retaining ring contacts a retaining shoulder  625  of the deceleration element  600 . 
       FIG. 20  shows the piston  100  together with the deceleration element  600  in a side view. The piston has a shaft  140 , a convexo-conical section  135  and a belt passage  130 . A coupling plug-in part  110  with coupling recesses  120  connects to the belt passage. The deceleration element  600  has a stop surface  620  for the convexo-conical section  135  of the piston  100  and is held in the not-shown receptacle element. 
       FIG. 21  shows the piston  100  together with the deceleration element  600  in a longitudinal section. The stop surface  620  of the deceleration element  600  is adapted to the geometry of the piston  100  and therefore likewise has a convexo-conical section. In this way, a planar contact of the piston  100  against the deceleration element  600  is guaranteed. Thus, excess energy of the piston  100  is absorbed sufficiently by the deceleration element. Furthermore, the deceleration element  600  has a piston passage  640  through which the shaft  140  of the piston  100  extends. 
       FIG. 22  shows the deceleration element  600  in a side view. The deceleration element  600  has a stop element  610  and also an impact-damping element  630  that connect to each other along a setting axis S of the driving device. Excess impact energy of a not-shown piston is initially received by the stop element  610  and then damped by the impact-damping element  630 , that is, expanded in time. The impact energy is finally received by the not-shown receptacle element that has a floor as a first support wall for supporting the deceleration element  600  in the impact direction and a side wall as a second support wall for supporting the deceleration element  600  perpendicular to the impact direction. 
       FIG. 23  shows the deceleration element  600  with the holder  650  in a longitudinal section. The deceleration element  600  has a stop element  610  and also an impact-damping element  630  that connect to each other along a setting axis S of the driving device. The stop element  610  is made from steel; in contrast, the impact-damping element  630  is made from an elastomer. A mass of the impact-damping element  630  advantageously equals between 40% and 60% of a mass of the stop element. 
       FIG. 24  shows the driving device  10  in a perspective view with opened housing  20 . In the housing, the front roll holder  281  is to be seen. The deceleration element  600  is held in its position by the retaining ring  26 . The tab  690  has, among other things, the contact-pressing sensor  760  and the unlocking element  720 . The contact-pressing mechanism  750  has the guide channel  700  that advantageously comprises the contact-pressing sensor  760  and the connecting rod  770 . The magazine  40  has the advancing element  740  and the advancing spring  735 . 
     Furthermore, the driving device  10  has an unlocking switch  730  for an unlocking of the guide channel  700 , so that the guide channel  700  can be removed, for example, in order to be able to more easily remove clamped fastening elements. 
       FIG. 25  shows a contact-pressing mechanism  750  in a side view. The contact-pressing mechanism comprises a contact-pressing sensor  760 , an upper push rod  780 , a connecting rod  770  for connecting the upper push rod  780  to the contact-pressing sensor  760 , a lower push rod  790  connected to a front roll holder  281  and a crossbar  795  linked to the upper push rod  780  and to the lower push rod. A trigger rod  820  is connected at one end to a trigger  34 . The crossbar  795  has an elongated hole  775 . Furthermore, a coupling mechanism  150  is shown that is held in a locked position by a pawl  800 . 
       FIG. 26  shows a partial view of the contact-pressing mechanism  750 . Shown are the upper push rod  780 , the lower push rod  790 , the crossbar  795  and the trigger rod  820 . The trigger rod  820  has a trigger diverter  825  projecting laterally from the trigger rod. Furthermore, a pin element  830  that has a trigger pin  840  and is guided in a pawl guide  850  is shown. The trigger pin  840  is guided, on its side, in the elongated hole  775 . Furthermore, it becomes clear that the lower push rod  790  has a pin block  860 . 
       FIG. 27  shows another partial view of the contact-pressing mechanism  750 . Shown are the crossbar  795 , the trigger rod  820  with the trigger diverter  825 , the pin element  830 , the trigger pin  840 , the pawl guide  850  and also the pawl  800 . 
       FIG. 28  shows the trigger  34  and the trigger rod  820  in a perspective view, but from the other side of the device than the preceding figures. The trigger has a trigger actuator  870 , a trigger spring  880  and also a trigger rod spring  828  that applies a load on the trigger diverter  825 . Furthermore, it becomes clear that the trigger rod  820  is provided laterally with a pin notch  822  that is arranged at the height of the trigger pin  840 . 
     In order to allow a user of the driving device to initiate a driving procedure by pulling the trigger  34 , the trigger pin  840  must engage with the pin notch  822 . Only then does a downward movement of the trigger rod  820  cause an engagement of the trigger pin  840  and thus, by means of the pawl guide  850 , a downward movement of the pawl  800 , wherein the coupling mechanism  150  is unlocked and the driving procedure is initiated. Pulling of the trigger  34  causes, in each case, by means of the beveled trigger diverter  825 , a downward movement of the trigger rod  820 . 
     A prerequisite for the trigger rod  840  engaging with the pin notch  822  is that the elongated hole  775  in the crossbar  795  is located in its rearmost position, that is, at the right in the drawing. In the position shown, for example, in  FIG. 26 , the elongated hole  775  and thus also the trigger pin  840  is located too far forward, so that the trigger pin  840  does not engage with the pin notch  822 . Pulling the trigger  34  thus does nothing. The reason for this is that the upper push rod  780  is located in its front position and thus indicates that the driving device is not pressed onto a substrate. 
     A similar situation is produced when a not-shown spring is not tensioned. Then, the front roll holder  281  and thus also the lower push rod  790  are each located in their forward position, so that the elongated hole  775  again moves the trigger pin  840  out of engagement with the pin notch  822 . As a result, pulling the trigger  34  also does nothing when the spring is not tensioned. 
     A different situation is shown in  FIG. 25 . There, the driving device is both in a state that can be driven, namely with tensioned spring, and also pressed onto a substrate. Consequently, the upper push rod  780  and the lower push rod  790  are each located in their rearmost position. The elongated hole  775  of the crossbar  795  and thus also the trigger pin  740  are then each located likewise in their rearmost position, in the right in the drawing. Consequently, the trigger pin  740  engages in the pin notch  722 , and pulling the trigger  34  causes the trigger pin  740  to be carried along downward by the pin notch  722  by means of the trigger rod  820 . By means of the pin element  830  and the pawl guide  850 , the pawl  800  is likewise diverted downward against the spring force of the pawl spring  810 , so that the coupling mechanism  150  is moved into its unlocked position and an unlocked piston in the coupling mechanism  150  transfers the tensioning energy of the spring to a fastening element. 
     In order to counteract the risk that the pawl  800  is diverted by vibrations, for example, when a user roughly sets the driving device in the tensioned state of the spring, the lower push rod  790  is provided with the pin lock  860 . The driving device is then in the state shown in  FIG. 26 . Therefore, because the pin lock  860  prevents the pin  840  and thus the pawl  800  from downward movement, the driving device is protected from such inadvertent triggering of a driving procedure. 
       FIG. 29  shows the second housing shell  28  of the housing that is otherwise not shown in detail. The second housing shell  28  consists of, in particular, a fiber-reinforced plastic and has parts of the grip  30 , the magazine  40  and the bridge  50  connecting the grip  30  to the magazine  40 . Furthermore, the second housing shell  28  has support elements  15  for a support relative to the not-shown first housing shell. Furthermore, the second housing shell  28  has a guide groove  286  for guiding not-shown roll holders. 
     For holding a not-shown deceleration element for decelerating an energy-transfer element or a holder carrying the deceleration element, the second housing shell  28  has a support flange  23  and also a retaining flange  19 , wherein the deceleration element or the holder is held in a gap  18  between the support flange  23  and the retaining flange  19 . The deceleration element or the holder is then supported, in particular, on the support flange. In order to introduce impact forces that occur due to impacts of the piston on the deceleration element with reduced stress spikes into the housing, the second housing shell  28  has first reinforcement ribs  21  that are connected to the support flange  23  and/or to the retaining flange  19 . 
     For fastening a drive mechanism that is held in the housing for transporting the energy-transfer element from the starting position into the setting position and back, the second housing shell  28  has two support elements formed as flanges  25 . In order to transfer and/or introduce tensile forces that occur, in particular, between the two flanges  25  into the housing, the second housing shell  28  has second reinforcement ribs  22  that are connected to the flanges  25 . 
     The holder is fastened to the drive mechanism only by means of the housing, so that impact forces that are not completely absorbed by the deceleration element are transferred to the drive mechanism only by means of the housing. 
       FIG. 30  shows a tab  690  of a device for driving a fastening element into a substrate in a perspective view. The tab  690  comprises a guide channel  700  for guiding the fastening element with a rear end  701  and a holder  650  arranged displaceable relative to the guide channel  700  in the direction of the setting axis for holding a not-shown deceleration element. The holder  650  has a bolt receptacle  680  with a feed recess  704  through which a nail strip  705  with a plurality of fastening elements  706  can be fed to a launching section  702  of the guide channel  700 . The guide channel  700  is simultaneously used as a contact-pressing sensor of a contact-pressing mechanism that has a connecting rod  770  that is similarly displaced when the guide channel  700  is displaced and thus indicates a contact pressing of the device onto a substrate. 
       FIG. 31  shows the tab  690  in another perspective view. The guide channel  700  is part of a contact-pressing mechanism for identifying the distance of the driving device to the substrate in the direction of a setting axis S. The tab  690  further has a locking element  710  that allows displacement of the guide channel  700  in a released position and prevents displacement of the guide channel  700  in a locked position. The locking element  710  is to be loaded by an engaging spring hidden in the drawing in a direction toward the nail strip  705 . As long as no fastening element is arranged in the launching section  702  in the guide channel  700 , the locking element  710  is located in the locked position in which it blocks the guide channel  700 , as shown in  FIG. 31 . 
       FIG. 32  shows the tab  690  in another perspective view. As soon as a fastening element is arranged in the launching section  702  in the guide channel  700 , the locking element  710  is located in a released position in which it can pass the guide channel  700 , as shown in  FIG. 32 . Therefore, the driving device can be pressed onto the substrate. In this case, the connecting rod  770  is displaced, so that the contact pressing can guarantee the triggering of the driving procedure. 
       FIG. 33  shows the tab  690  in a cross section. The guide channel  700  has a launching section  702 . The locking element  710  has, adjacent to the launching section, a locking shoulder  712  that can be loaded by the nail strip  705  or also individual nails. 
       FIG. 34  shows the tab  690  in another cross section. The locking element  710  is located in the released position, so that the locking element  710  can pass the guide channel  700  when moving in the direction of the setting axis S. 
       FIG. 35  shows a driving device  10  with the tab  690  in a partial view. The tab  690  has, in addition, an unlocking element  720  that can be actuated by a user and holds, in an unlocked position, the locking element  710  in its released position and allows, in a waiting position, a movement of the locking element in its locked position. On the side of the unlocking element  720  facing away from the viewer, a not-shown disengaging spring is located that loads the unlocking element  720  away from the locking element  710 . Furthermore, the unlocking switch  730  is shown. 
       FIG. 36  shows the driving device  10  with the tab  690  in another partial view. A feed mechanism constructed as magazine  40  for fastening elements has, at the launching section, an advancing spring  735  and also an advancing element  740 . The advancing spring  735  loads the advancing element  740  and thus also optionally fastening elements located in the magazine toward the guide channel  700 . The unlocking element  720  has, at a projection  721  of the unlocking element  720 , a first catch element  746 , and the advancing element  740  has a second catch element  747 . The first and the second catch element lock with each other when the unlocking element  720  is moved into the unlocked position. In this state, individual fastening elements could be introduced along the setting axis S into the guide channel  700 . As soon as the magazine  40  has been reloaded, the engagement between the unlocking element  720  and the advancing element  740  is detached, and the driving device can be used again as usual. 
       FIG. 37  shows a schematic view of a driving device  10 . The driving device  10  comprises a housing  20  which holds a piston  100 , a coupling mechanism  150  held closed by a retaining element constructed as pawl  800 , a spring  200  with a front spring element  210  and a rear spring element  220 , a roll train  260  with a force diverter constructed as belt  270 , a front roll holder  281  and a rear roll holder  282 , a spindle drive  300  with a spindle  310  and a spindle nut  320 , a transmission  400 , a motor  480  and a control mechanism  500 . 
     The driving device  10  further has a guide channel  700  for the fastening element and a contact-pressing mechanism  750 . In addition, the housing  20  has a grip  30  on which a hand switch  35  is arranged. 
     The control mechanism  500  communicates with the hand switch  35  and also with several sensors  990 ,  992 ,  994 ,  996 ,  998 , in order to detect the operating state of the driving device  10 .  990 ,  992 ,  994 ,  996 ,  998  each have a Hall probe that detects the movement of a not-shown magnetic armature that is arranged, in particular, fastened, on each element to be detected. 
     With the guide channel sensor  990 , a movement of the contact-pressing mechanism  750  toward the front is detected, wherein it is indicated that the guide channel  700  was removed from the driving device  10 . With the contact-pressing sensor  992 , a movement of the contact-pressing mechanism  750  toward the back is detected, wherein it is indicated that the driving device  10  is pressed onto a substrate. With the roll holder sensor, a movement of the front roll holder  281  is detected, wherein it is indicated whether the spring  200  is tensioned. With the pawl sensor  996 , a movement of the pawl  800  is detected, wherein it is indicated whether a coupling mechanism  150  is held in its closed state. With the spindle sensor  998 , it is finally detected whether the spindle nut  320  or a retracting rod mounted on the spindle nut  320  is in its rearmost position. 
       FIG. 38  shows a control configuration of the driving device in a simplified representation. The control mechanism  1024  is indicated by a central rectangle. The switch and/or sensor mechanisms  1031  to  1033  supply information or signals, as indicated by arrows, to the control mechanism  1024 . A hand or main switch  1070  of the driving device connects to the control mechanism  1024 . Through a double-headed arrow it is indicated that the control mechanism  1024  communicates with the accumulator  1025 . Through additional arrows and a rectangle, a catch  1071  is indicated. 
     According to one embodiment, the hand switch detects holding by the user, and the control reacts to the switch being released by discharging the stored energy. In this way, safety is increased for the case of unexpected errors, such as dropping the bolt setting device. 
     Through additional arrows and rectangles  1072  and  1073 , a voltage measurement and a current measurement are indicated. Through another rectangle  1074 , a shutdown device is indicated. Through another rectangle, a B6 bridge  1075  is indicated. This involves a 6-pulse bridge circuit with semiconductor elements for controlling the electrical drive motor  1020 . This is preferably controlled by driver components that are controlled in turn preferably by a controller. Such integrated driver components have, in addition to the suitable driving of the bridge, also the advantage that, if an under-voltage occurs, the switch elements of the B6 bridge are brought into a defined state. 
     Through an additional rectangle  1076 , a temperature sensor is indicated that communicates with the shutdown device  1074  and the control mechanism  1024 . Through another arrow it is indicated that the control mechanism  1024  outputs information to the display  1051 . Through additional double-headed arrows it is indicated that the control mechanism  1024  communicates with the interface  1052  and with another service interface  1077 . 
     Preferably, for the protection of the control device and/or the drive motor, in addition to the switches of the B6 bridge, another switch element is inserted in series that separates the power flow from the accumulator to the loads by means of the shutdown device  1074  through operating data, such as over-current and/or temperature rise. 
     For an improved and stable operation of the B6 bridge, the use of storage devices, such as capacitors, is useful. So that no current spikes are produced by the quick charging of such storage components, which would lead to increased wear of the electrical contacts, when the accumulator and control device are connected, these storage devices are preferably placed between the additional switch element and the B6 bridge and charged in a controlled manner according to the accumulator supply by means of suitable switching of the additional switch element. 
     Through additional rectangles  1078  and  1079 , a fan and a locking brake are indicated that are controlled by the control mechanism  1024 . The fan  1078  is used for circulating cooling air around components in the driving device for cooling. The locking brake  1079  is used for slowing down movements when the energy storage device  1010  is discharged and/or for holding the energy storage device in the tensioned or charged state. The locking brake  1079  can interact, for example, with the belt drive  1018  for this purpose. 
       FIG. 39  shows the control procedure of a driving device in the form of a state diagram in which each circle represents a device state or operating mode and each arrow represents a process through which the driving device is moved from a first device state or operating mode into a second. 
     In the “Accumulator removed” device state  900 , an electrical-energy storage device, such as, for example, an accumulator, has been removed from the driving device. By inserting an electrical-energy storage device into the driving device, the driving device is set into the “Off” device state  910 . In the “Off” device state  910 , an electrical-energy storage device is inserted into the driving device, but the driving device is still turned off. By turning on with the hand switch  35  from  FIG. 37 , the “Reset” device mode  920  is reached in which the control electronics of the driving device are initialized. After a self-test, the driving device is finally moved into the “Tensioning” operating mode  930  in which a mechanical-energy storage device of the driving device is tensioned. 
     If the driving device is turned off with the hand switch  35  in the “Tensioning” operating mode  930 , the driving device is moved directly back into the “Off” device state  910  when the driving device is still not tensioned. In contrast, for a partially tensioned driving device, the driving device is moved into the “Tension releasing” operating mode  950  in which tension is released from the mechanical-energy storage device of the driving device. On the other hand, if a tension path set in advance is reached in the “Tensioning” operating mode  930 , then the driving device is moved into the “Ready-to-use” device state  940 . Reaching the tension path is detected with the help of the roll holder sensor  994  in  FIG. 37 . 
     Starting from the “Ready-to-use” device state  940 , the driving device is moved into the “Tension releasing” operating mode  950  if the hand switch  35  is turned off or by the determination that more time has elapsed than a predetermined time since reaching the “Ready-to-use” device state  940 , for example, more than 60 seconds. In contrast, if the driving device has been pressed onto a substrate in due time, the driving device is moved to the “Ready-to-drive” device state  960  in which the driving device is ready for a driving procedure. Contact pressure is here detected with the help of the contact-pressing sensor  992  from  FIG. 37 . 
     Starting from the “Ready-to-drive” device state  960 , the driving device is moved into the “Tension releasing” operating mode  950  and then into the “Off” device state  910  if the hand switch  35  is turned off or by the determination that more time has elapsed than a predetermined time since reaching the “Ready-to-drive” device state  960 , for example, more than six seconds. In contrast, if the driving device is turned on again by actuation of the hand switch  35 , while it is in the “Tension releasing” operating mode  950 , it is moved from the “Tension releasing” operating mode  950  directly to the “Tensioning” operating mode  930 . Starting from the “Ready to drive” operating mode  960 , the driving device is moved back into the “Ready-to-use” device state  950  by lifting the driving device from the substrate. The lifting is here detected with the help of the contact-pressing sensor  992 . 
     Starting from the “Ready-to-drive” operating mode  960 , by pulling the trigger the driving device is moved into the “Driving” operating mode  970  in which a fastening element is driven into the substrate and the energy-transfer element moves into the starting position and is also coupled in the coupling mechanism. Pulling the trigger causes an opening of the coupling mechanism  150  in  FIG. 37  by pivoting the associated pawl  800 , which is detected with the help of the pawl sensor  996 . From the “Driving” operating mode  970 , the driving device is moved into the “Tensioning” operating mode  930  as soon as the driving device is lifted from the substrate. The lifting is detected here, in turn, with the contact-pressing sensor  992 . 
       FIG. 40  shows a more detailed state diagram of the “Tension releasing” operating mode  950 . In the “Tension releasing” operating mode  950 , initially the “Stopping motor” operating mode  952  is executed in which possibly existing rotation of the motor is stopped. The “Stopping motor” operating mode  952  is reached from any other operating mode or device state when the device is turned off with the hand switch  35 . After a predetermined time span, the “Braking motor” operating mode  954  is then executed in which the motor is short-circuited and, operating as a generator, the tension-releasing procedure is braked. After another predetermined time span, the “Driving motor” operating mode  956  is executed in which the motor actively further brakes the tension-releasing process and/or brings the linear output into a predefined final position. Finally, the “Tension releasing complete” device state  958  is reached. 
       FIG. 41  shows a more detailed state diagram of the “Driving” operating mode  970 . In the “Driving” operating mode  970 , initially the “Waiting for driving procedure” operating mode  971 , then after the piston has reached its setting position, the “Fast motor running and open retaining mechanism” operating mode  972 , then the “Slow motor running” operating mode  973 , then the “Stopping motor” operating mode  974 , then the “Coupling piston” operating mode  975 , and finally the “Motor off and waiting for nail” operating mode  976  are executed. Reaching the coupling by the piston is here identified by a spindle sensor  998  from  FIG. 37 . Finally, the driving device is moved from there into the “Off” device state  910  by the determination that more time has elapsed than a predetermined time since reaching the “Motor off and waiting for nail” operating mode  976 , for example, more time than 60 seconds. 
       FIG. 42  shows a more detailed state diagram of the “Tensioning” operating mode  930 . In the “Tensioning” operating mode  930 , initially the “Initializing” operating mode  932  is executed in which the control mechanism tests, with the help of the spindle sensor  998 , whether the linear output is in its rearmost position or not and, with the help of the pawl sensor  996 , whether the retaining element is holding the coupling mechanism closed or not. If the linear output is in its rearmost position and the retaining element holds the coupling mechanism closed, the device moves immediately into the “Tensioning mechanical-energy storage device” operating mode  934  in which the mechanical-energy storage device is tensioned because it is guaranteed that the energy-transfer element is coupled in the coupling mechanism. 
     If, in the “Initializing” operating mode  932 , it is determined that the linear output is in its rearmost position, but the retaining element is not holding the coupling mechanism closed, initially the “Driving up linear output” operating mode  938  and after a predetermined time span the “Driving back linear output” operating mode  936  are executed, so that the linear output transports and couples the energy-transfer element backward for coupling. As soon as the control mechanism determines that the linear output is in its rearmost position and the retaining element is holding the coupling mechanism closed, the device is moved into the “Tensioning mechanical-energy storage device” operating mode  934 . 
     If, in the “Initializing” operating mode  932 , it is determined that the linear output is not in its rearmost position, then the “Driving back linear output” operating mode  936  is performed immediately. As soon as the control mechanism determines, with the help of the spindle sensor  998 , that the linear output is in its rearmost position and the holding element is holding the coupling mechanism closed, the device moves, in turn, into the “Tensioning mechanical-energy storage device”  934 . 
       FIG. 43  shows a longitudinal section of the driving device  10  after a fastening element has been driven, with the help of the piston  100 , forward, that is, toward the left in the drawing, into a substrate. The piston is located in its setting position. The front spring element  210  and the back spring element  220  are located in the non-tensioned state in which they actually still have a certain residual tension. The front roll holder  281  is in its front-most position in the operating procedure, and the rear roll holder  282  is in its rearmost position in the operating procedure. The spindle nut  320  is located at the front end of the spindle  310 . The belt  270  is essentially load-free due to the spring elements  210 ,  220  that are, under some circumstances, relaxed to a residual tension. 
     As soon as the control mechanism  500  has identified, by means of a sensor, that the piston  100  is in its setting position, the control mechanism  500  triggers a retracting procedure in which the piston  100  is transported into its starting position. For this purpose, by means of the transmission  400 , the motor rotates the spindle  310  in a first rotational direction, so that the spindle nut  320  locked in rotation is moved backward. 
     The retracting rods here engage in the retracting pin of the piston  100  and thus likewise transport the piston  100  backward. The piston  100  here carries along the belt  270 , wherein, however, the spring elements  210 ,  220  are not tensioned, because the spindle nut  320  likewise carries the belt  270  backward and here releases, by means of the rear rolls  292 , just as much belt length as the piston pulls in between the front rolls  291 . The belt  270  thus remains essentially load-free during the retracting procedure. 
       FIG. 44  shows a longitudinal section of the driving device  10  after the retracting procedure. The piston  100  is located in its starting position and is coupled with its coupling plug-in part  110  in the coupling mechanism  150 . The front spring element  210  and the rear spring element  220  are further each located in their non-tensioned state; the front roll holder  281  is in its front-most position, and the rear roll holder  282  is in its rearmost position. The spindle nut  320  is located on the rear end of the spindle  310 . Due to the relaxed spring elements  210 ,  220 , the belt  270  is further essentially load-free. 
     If the driving device is now lifted from the substrate, so that the contact-pressing mechanism  750  is displaced forward relative to the guide channel  700 , then the control mechanism  500  causes a tensioning procedure in which the spring elements  210 ,  220  are tensioned. For this purpose, by means of the transmission  400 , the motor rotates the spindle  310  in a second rotational direction set opposite the first rotational direction, so that the spindle nut  320  that is locked in rotation is moved forward. 
     The coupling mechanism  150  here holds the coupling plug-in part  110  of the piston  100  fixed, so that the belt length that is pulled from the spindle nut  320  between the rear rolls  292  cannot be released by the piston. The roll holders  281 ,  282  are therefore moved toward each other and the spring elements  210 ,  220  are tensioned. 
       FIG. 45  shows a longitudinal section of the driving device  10  after the tensioning procedure. The piston  100  is further located in its starting position and is coupled with its coupling plug-in part  110  in the coupling mechanism  150 . The front spring element  210  and the rear spring element  220  are tensioned; the front roll holder  281  is in its rearmost position and the rear roll holder  282  is in its front-most position. The spindle nut  320  is located at the front end of the spindle  310 . The belt  270  diverts the tensioning force of the spring elements  210 ,  220  to the rolls  291 ,  292  and transfers the tensioning force to the piston  100  that is held against the tensioning force by the coupling mechanism  150 . 
     The driving device is now ready for a driving procedure. As soon as a user pulls the trigger  34 , the coupling mechanism  150  releases the piston  100  that then transfers the tensioning energy of the spring elements  210 ,  220  to a fastening element and drives the fastening element into the substrate.