Patent Publication Number: US-10328555-B2

Title: Driving-in device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This patent application is the U.S. National Stage of International Patent Application No. PCT/EP2014/075604, filed Nov. 26, 2014, which claims the benefit of European Patent Application No. 13195724.3, filed Dec. 4, 2013, which are each incorporated by reference. 
     TECHNICAL FIELD 
     The application relates to a device for driving a fastening element into an underlying surface. 
     BACKGROUND OF THE INVENTION 
     Such devices typically comprise a piston for transmitting energy to the fastening element. The required energy must be provided in a very short time, which is why in so-called spring nailers, for example, a spring is first tensioned that abruptly transmits the tensioning energy during the driving process to the piston and accelerates the latter toward the fastening element. 
     The energy with which the fastening element is driven into the underlying surface has an upward bound for such devices, so that the devices cannot be arbitrarily used for all fastening elements and every underlying surface. It is therefore desirable to make driving devices available that can transmit sufficient energy to a fastening element. 
     BRIEF SUMMARY OF THE INVENTION 
     According to one aspect of the invention, a device for driving a fastening element into an underlying surface comprises a mechanical energy accumulator for storing mechanical energy; an energy transmitting element for transmitting energy from the mechanical energy accumulator to the fastening element; an energy transmitting device for transmitting energy from an energy source to the mechanical energy accumulator; a housing with a first and a second housing part, the first housing part being connected to the second housing part in order to form an interior, in which the mechanical energy accumulator is arranged, between the first and second housing part; and an intermediate element, by means of which the mechanical energy accumulator can be secured to the first housing part at least temporarily while energy is being stored in the mechanical energy accumulator. This simplifies the installation and/or removal of an already pretensioned mechanical energy accumulator. 
     According to an advantageous embodiment, the mechanical energy accumulator is supported firstly on the first housing part and secondly on the intermediate element against release of the energy stored in the mechanical energy accumulator. According to an alternative embodiment, the mechanical energy accumulator is supported only on the first housing part against release of the energy stored in the mechanical energy accumulator. According to an alternative embodiment, the mechanical energy accumulator is supported only on the intermediate element against release of the energy stored in the mechanical energy accumulator. 
     According to an advantageous embodiment, the intermediate element divides the interior into a first partial chamber and a second partial chamber. In that way, a preferably dust-tight and particularly preferably an air-tight separation of the first and the second partial chambers is implemented. For this purpose, the intermediate element preferably has a sealing element which particularly preferably closes off the intermediate element circumferentially. The first partial chamber is preferably closed dust-tightly relative to the surroundings and particularly preferably air-tightly, and the second partial chamber can be ventilated with ambient air. Thereby it is possible to ventilate a heat-producing device such as an electric motor without contaminating a dust-sensitive device such as a mechanical energy accumulator. The mechanical energy accumulator is therefore preferably arranged in the first partial chamber. The energy transmission device also preferably comprises a motor that is arranged in the second partial chamber. The energy transmission device also preferably comprises a transmission that is arranged in the first partial chamber. 
     The motor, the transmission if present, a sensor and/or an electrical line are preferably mounted on the intermediate element. 
     According to an advantageous embodiment, the mechanical energy accumulator comprises a helical spring. According to another advantageous embodiment, the mechanical energy accumulator comprises a gas spring. 
     According to an advantageous embodiment, the energy transmission device comprises a motion converter having a rotary drive and a linear output for converting a rotational movement into a linear movement. Thus a rotation of a motor, for example, produces a linear tensioning motion of the mechanical energy accumulator. The motion converter is preferably arranged in the first partial chamber. The motion converter also comprises a spindle drive comprising a spindle and a spindle nut arranged on the spindle. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) 
       Embodiments of a device for driving a fastener element into an underlying surface will be described in detail below using examples, with reference to the drawings. Therein: 
         FIG. 1  shows a side view of a driving device, 
         FIG. 2  shows a side view of a driving device with an opened housing, 
         FIG. 3  shows a partial view of a driving device, 
         FIG. 4  shows a side view of a driving device with an opened housing, 
         FIG. 5  shows an energy transmission device of a driving device, 
         FIG. 6  shows a partial view of a driving device, 
         FIG. 7  shows a partial sectional view of a driving device, 
         FIG. 8  shows a side view of a driving device, 
         FIG. 9  shows a plan view of a driving device, 
         FIG. 10  shows a partial view of a driving device, 
         FIG. 11  shows an intermediate element, 
         FIG. 12  shows a partial view of a driving device with an opened housing, 
         FIG. 13  shows a partial view of an energy transmission device, 
         FIG. 14  shows a partial view of an energy transmission device, 
         FIG. 15  shows a partial view of an energy transmission device, 
         FIG. 16  shows a partial view of an energy transmission device, 
         FIG. 17  shows a side view of an energy transmission device, 
         FIG. 18  shows a partial sectional view of an energy transmission device, 
         FIG. 19  shows a partial view of a driving device with an opened housing, 
         FIG. 20  shows a side and a frontal view of a driving device, 
         FIG. 21  shows a side and a frontal view of a driving device, 
         FIG. 22  shows a side view of a driving device, 
         FIG. 23  shows a side and a frontal view of a driving device, 
         FIG. 24  shows a partial view of a driving device, 
         FIG. 25  shows a partial view of a driving device, 
         FIG. 26  shows a partial view of a driving device, 
         FIG. 27  shows an oblique view of a scaffold hook, and 
         FIG. 28  shows a side view of a scaffold hook. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 1-4  show a battery-operated fastener-setting tool  100  as a device for driving a fastening element into an underlying surface. The fastener-setting tool  100  comprises a housing  1  that contains a brushless DC motor  11 , a mechanical energy accumulator designed as two helical springs  9  and a nail driving device. The housing also contains a control electronics unit  12  for controlling the operation and a sensor system for determining tool states. The energy for loading the helical springs  9  is provided by a rechargeable battery  5  which is detachable from the tool and thus serves as an energy source. The tool has a fastener guide  2  as a pressing probe, which is pressed against an underlying surface during use of the fastener-setting tool  100 . Thereby the fastener-setting tool  100  is put into triggering standby and the user can pull a trigger  6 . A magazine  3  bears a plurality of fastening means designed as nails  3   a , which are supplied to the fastener-setting tool  100 . The magazine  3  has a support base  4 , which helps the user press the fastener-setting tool  100  at a right angle onto the underlying surface. 
     The housing  1  comprises a first housing part  71  and a second housing part  72 , which are connected to one another in such a manner that an interior, in which the helical springs  9  are arranged, is formed between them. An intermediate element is designed as an intermediate plate  7  having a sealing element  13  and arranged between the first housing part  71  and a second housing part  72  in such a manner that the intermediate plate  7  separates two partial chambers from one another. A first partial chamber is formed between the intermediate plate  7  and the first housing part  71 , and a second partial chamber is formed between the intermediate plate  7  and the second housing part  72 . The housing  1  further comprises a cover hood  8  in an anterior region of the fastener-setting tool  100 . 
     The intermediate plate  7 , together with the first housing part  71 , forms the support for the upright ends of the two helical springs  9 . The other end of the springs is supported on two roller brackets  10 , which are mounted axially movably in the housing  1 . Thereby four different spaces are formed inside the housing  1 , namely the first partial chamber, closed off dust-tightly from the surroundings and in which the helical springs  9  are arranged; the second partial chamber, which can be vented via venting slots  73  in the second housing part  72  and in which the motor  11  is arranged; a handle region  74  through which electrical lines  75  are routed between the motor  11  and the control electronics unit  12 ; and a magazine region in which the nails  3   a  are transported. Since many mechanical parts are mounted directly in the plastic housing, stability and impact resistance of the housing  1  are important. Therefore it is proposed that the housing  1  and/or other supporting parts such as the intermediate plate  7  be produced from fiber-reinforced plastic, in particular PA12. In embodiments that are not shown, PA6 is used alternatively or additionally. 
     The cover hood  8 , together with the first housing part  71  and the second housing part  72 , forms the magazine  3 , in which the nails  3   a  are stored and transported before each setting, in front of an energy transmission element designed as a piston  20 . The cover hood  8  is connected at least partly by catch hooks  14  to the first housing part  71  and the second housing part  72 . 
     The motor  11  is subject to high acceleration forces occur during setting in the fastener-setting tool. To protect the motor  11  from such forces, it is mounted in a damped manner relative to the intermediate plate  7  and the housing  1  by means of a motor damper  23 . For example, the motor damper  23  can be directly injection-molded or vulcanized onto the motor assembly. This leads to a cost-effective design. To obtain good damping values that are, in particular, independent of the ambient temperature, the damper is preferably produced from polyurethane. In order to limit the exclusion of the damped motor, the motor is stopped after a defined excursion by a damped stop  24 . The damped stop  24  is attached to the intermediate plate  7  in the embodiment shown. In the other movement direction, the motor  11  likewise has an end stop, not shown here, in the housing  1 . It is designed as a fixed or damped stop. 
       FIG. 5  shows essential parts of the energy transmission device. A ball screw  18 , which is driven by the motor  11  via a transmission  19 , is mounted in the rear part of the fastener-setting tool  100 . The rotational motion of the ball screw  18  is converted into a linear motion of a spindle nut  21 . A tensioning belt  16  foxed to the spindle nut  21  transmits the linear movement to the rollers  17  and therefore to the roller brackets  10  that tension the helical springs  9 . The tensioning belt  16  running through an opening in the piston  20  then transmits the tensioning force of the helical springs  9  to the piston and can accelerate the piston in the direction of the front aperture of the tool as soon as it is released by a clutch  25  mounted in the fastener-setting tool  100 . The tensioning belt  16  guided through the opening of the piston  20  transmits power to the piston. In the area of the opening, the tensioning belt  16  is preferably made with a softer weave in comparison to the remainder of the belt  16  in order to prevent the belt from being damaged by the strong deflection under a high load. 
     The transmission  19  consists of at least one stage and can be designed as a gear transmission or a belt transmission. The gear wheels or belt wheels are preferably made from a plastic material. Metal spring supports  29  are used to mount the helical springs  9  between the first housing part  71  and the intermediate plate  7  in order to protect the plastic parts from wear. 
     The position of the roller bracket  10  can be determined by means of a magnet  46  attached to the roller bracket  10  and a sensor system described below. The roller bracket stands here as an example for various parts in the tool, the positions of which are of interest for controlling the fastener-setting tool  100 . In particular, these parts are monitored with a sensor system; in the described embodiment it uses magnets and Hall sensors. The magnet  46  is ideally snapped into plastic parts. 
       FIG. 6  shows that a force is transmitted to the roller bracket  10  by the tensioning belt  16  in order to tension the helical springs. Guide plates  22 , which offer stable guidance with low wear for the roller brackets  10 , are snapped into place in the housing  1  and in the intermediate plate  7  in order to support the roller brackets  10 . The guides have different widths on each side of the roller bracket  10  in the housing  1 , whereby incorrect installation is avoided. Two deflection rollers  30  that deflect the tensioning belt  16  by 180° are mounted on the roller brackets  10 . Since the tensioning belt  16  is loaded by high forces, the deflection rollers  30  are preferably coated in order to reduce friction due to slippage between the tensioning belt  16  and the defection roller  30  during acceleration. This reduces the wear on the tensioning belt  16 . For simplified installation, the deflection rollers  30  are mounted on cylindrical axles  48  that are snapped into the roller brackets. 
       FIG. 7  shows a section through the front part of the drive mechanism. A piston brake  27  mounted in this front part can catch the piston  20  in the event that not all the energy from the piston is transmitted to the fastening element during driving. In the embodiment shown, the piston brake  27  consists of a metallic cone ring  26  having a conical contact surface  26   a  for the piston  20  and also having an adjoining damping element  28 . The damping element  28  can be made of polyurethane, for example, and injection molded directly onto the cone ring  26 . The cone ring  26  can additionally have a coating that reduces the friction between the piston  20  and the cone ring  26 . This can prevent jamming of the piston  20  in the cone ring  26 . 
     Also visible in  FIG. 7  is a piston seal ring  45 , which seals the piston along  20  with its piston guide  20   a  radially outward. This can prevent particles from falling along the piston  20  into the interior of the fastener-setting tool  100 . The piston sealing ring  45  may be designed as a metal ring for example and slides under elastic initial tension on the piston  20 . The piston brake  27  is retained in a bracket  62 , which also comprises the piston guide  20   a  formed as a drilled hole. 
       FIG. 8  shows the second housing part  72  of the fastener-setting tool  100 . In particular, the magazine  3  with the nails  3   a  is visible. The nails are transported by a spring-loaded magazine slide  32 . The position of the magazine slide  33  is marked directly on the housing shell as a fill level indicator. If the number of nails falls below a minimum, pressing the fastener-setting tool  100  into place is prevented. This is accomplished by a nail detection mechanism, which detects the spring force  32  of the magazine slide onto a nail  3   a  that may be ready for setting. In a preferred embodiment, a slot in which the magazine slide runs is at least partially closed off by an elastic cover not shown here. This can reduce entry of dirt into the tool. 
     The fastener-setting tool  100  offers the possibility of setting fasteners that do not fit the magazine due to their dimensions as individual elements. For this purpose, the individual setting button  34  can be pressed when the magazine  3  is empty. This allows pressing the fastener-setting tool  100  into contact when the magazine  3  is empty. When the individual setting button is pressed, a single element can be loaded from the front into the fastener guide  2 . Because the individual setting button  34  is kept pressed by the magazine slide  32  in its most forward position, it is possible to prevent individual setting when the magazine is loaded, i.e. when the magazine slide  32  is in its rear position. 
       FIG. 9  shows the fastener-setting tool  100  in a plan view. The fastener-setting tool  100  has a fastener-ejection slide  36 . By pressing on the fastener-ejection slide  36 , a user can detach the fastener guide  2  from the fastener-setting tool  100 . This is particularly advantageous if elements jam in the fastener guide  2 . The latter can then be removed and cleaned. A scaffold hook  35  is pushed onto the fastener-setting tool  100 . Ventilation slots  73  for the motor  11  are also shown. 
     As shown in  FIG. 10 , the fastener-ejection slide  36  is designed in two parts. The actuating element  36   a  is mounted in the housing and drives an internally positioned latch  37 , which has a cutout  38 . If the actuating element  36   a  is pressed, the latch  37  moves into a position that allows the fastener guide  2  to be removed to the front (toward the viewer in  FIG. 10 ). This happens because a cam, not shown, on the fastener guide  2  can slide forward through the cutout  38  in the latch  37 . If the actuating element  36   a  is not pressed, the latch  37  blocks the cam of the fastener guide  2 . A spring is used to reset the latch  37  and the actuating element  36   a.    
     The bracket  62  for the piston brake  27  is used as a guide for the fastener guide  2  and the piston  20 . The bracket  62  also guides the nail-detection slide, not shown here, and the fastener-ejection slide  36 . These individual parts are resiliently mounted. In order to handle this assembly easily during installation, the bracket is  62  surrounded laterally by a two-part clamp  63  that secures the mounted individual parts. 
       FIG. 11  shows the intermediate plate  7 . The intermediate plate  7  is used as a support for a number of sensor circuit boards  39 . The sensor circuit boards  39  carry sensors that generate signals according to the position of other tool components. The control electronics  12  unit controls the fastener-setting tool  100  by means of these signals. For example, the position of a part carrying a permanent magnet may be monitored by means of a Hall sensor. Some sensor circuit boards  39  are connected to one another, by means of plug connections, for example, as shown in  FIG. 11 , or by fixedly soldered cables. The sensor circuit boards  39  are plugged, snapped or bolted into the intermediate plate  7 . A cable  40   a  connects the sensors to the tool electronics. The damped stop  24  for the motor  11  is likewise mounted on the intermediate plate  7 . In addition, the intermediate plate  7  comprises the sealing element  13 , a slot-like receptacle  41  for the motor damper  23 , and an abutment  42  for relieving the tension on the electrical lines  75  for the motor  11 . 
     The motor damper  23 , which is fixedly connected to the motor  11 , can be seen in  FIG. 12 . The motor damper  23 , along with the motor  11 , is axially and radially fixed in the slot-like receptacle  41  and a matching opposing contour on the housing  1 . The electrical lines  75  of the motor  11  are clamped against the abutment  42  by means of a clamping element  42   a . Molded-on plastic parts, which can be plugged into the abutment  42  in the intermediate plate  7 , are located on the electrical lines  75 . This realizes a relief of tension for the electrical lines  75 . The electrical lines  75  are guided and run through the handle area  74  to the control electronics  12 . For this purpose, a cable duct  44 , which is also provided for part of the support of the trigger  6  in addition to receiving the cable, is located in the handle. Together with the sealing element  13 , the motor damper  23  is used for dust-tight separation of the first partial chamber from the second partial chamber. 
       FIG. 13  shows the trigger mechanism of the tool in the initial state. The fastener-setting tool  100  comprises a clutch  25 , which is able to hold the piston  20  in its initial position against the force transmitted by the tensioning belt, not shown here. The clutch  25  is held closed by a pawl  51 . If the helical springs  9  are tensioned and the fastener-setting tool  100  is pressed against the underlying surface, the pawl  51  can be pushed outward by a triggering plate  52 . In the process, the pawl  51  turns about an axis of rotation  54  and thus releases the clutch  25 . The piston  20  then moves in the direction of the nail  3   a  (to the right in  FIG. 13 ) and drives the nail  3   a  into the underlying surface. The triggering plate  52  is driven via a deflection lever  53  when the user presses the trigger  6 . The pawl  51  is advantageously made from a very rigid fiber-reinforced plastic material. Thereby it is light, reacts quickly and is nevertheless stiff enough to be able to handle its function. 
       FIG. 14  shows the trigger mechanism when the helical springs  9  are tensioned. The helical springs  9  are tensioned by pulling the tensioning belt via the spindle nut  21  in the direction of the clutch  25  while holding the piston  20  in the clutch  25 . At the end of this tensioning movement, the triggering plate  52  is pushed by the transmission element  57  into a position that allows it to come into contact with and trigger the pawl  51 . The spindle nut  21  has a snapped-in magnet  46 , which is used to determine the position of the spindle nut  21 . 
       FIG. 15  shows the triggering mechanism when the fastener-setting tool  100  is pressed against the underlying surface. Due to this pressing contact, the fastener guide  2  is pushed into the tool. This movement is transmitted by a pressing rod  49  onto a blocking lever  55 . This blocking lever is used to block or enable the movement of the pawl  51 . The pawl  51  is enabled via the pressing motion but not actuated. 
       FIG. 16  shows the triggering mechanism with setting triggered. The triggering plate  52  has pressed the pawl  51  outward and released the clutch in the process. The piston moves into a front position no longer visible here. The pawl  51  likewise has a snapped in magnet  46 , which is used to detect the position of the pawl  51  and thus the shifting position of the clutch  25 . 
       FIG. 17  shows the helical springs  9  and the energy transmission device comprising the tensioning belt  16 , the deflection rollers  17 , the ball screw  18 , the piston  20  and the clutch  25 . The clutch  25  is held by a plate  56 , which is seated in the housing. Two hooks  50  are fastened to the spindle nut  21 . They move with the spindle nut  21  and are guided in the plate  56 . The hooks  50  each have a slot  58  in which a cam  57  fastened to the piston runs. After the setting, the slot  58  and its closed end on the side facing the spindle nut  21  allow the spindle nut  21  to pull the piston  20  into its initial position in the clutch  25 . The cams  57  on the piston  20  are each produced as part of the piston. In embodiments not shown, the cams are produced by a different method and then connected to the piston. 
       FIG. 18  shows a section through the clutch  25 . The ball screw  18  is seated in the plate  56 . Since high axial forces act upon the ball screw  18  during tensioning of the helical springs  9 , the ball screw  18  is supported against the plate via a screwed-on nut  61  on a rolling bearing  59 . On the other hand, there are axial forces in the opposite direction during the return of the piston  20  into the clutch  25 . These axial forces are absorbed by a sliding bearing ring  60 . A clutch hub  62  is form-fittingly connected to the plate  56 , for example by orbital riveting. In embodiments not shown, the clutch hub is materially bonded to the plate, e.g. soldered or welded. 
       FIG. 19  shows the rear part of the fastener driving device  100  with an opened housing  1 . The transmission  19  conducts the rotational movement of the motor  11  stepped-down to the ball screw  18 . The transmission  19  consists of two stages. The gear wheels  19   a  are produced from plastic materials, for example. The axle  80  of the central gear stage is mounted in the intermediate plate  7  and in a transmission plate  64 . The transmission plate  64  itself is bolted onto the intermediate plate  7 . This leads to a compact construction. The transmission plate  64  additionally has a protruding tab  64   a , which extends behind the rotational axis of the ball screw  18 . The tab  64   a  protects the ball screw  18  and the gear wheel  19   a  of the third transmission stage in case of an impact on the rear end of the tool (from the left in  FIG. 19 ), for example in case the fastener-setting device  100  is dropped from a great height. 
     When the housing  1  is closed, the sealing element  13  and the motor damper  23  seal off the first partial chamber, with the transmission  19  therein, from the second partial chamber with the motor  11  therein. The sealing element  13  is designed as an open ring, closed off by the motor damper  23 . The sealing element  13  preferably consists of an elastic material, particularly preferably an elastomer, which is sprayed onto or molded onto the intermediate plate  7 . 
       FIG. 20  shows a fastener-setting tool  200  that has two lamps  210  for lighting up the driving region  205  for the fastening element to be set. 
     The lamps  210  are mounted laterally on the magazine  220 , where the accelerations during a setting process are lower than on a main body  230  of the fastener-setting tool  200 . 
       FIG. 21  shows a fastener-setting tool  300  that has two lamps  310  for lighting up the driving region  305  for the fastening element to be set. The lamps  310  are mounted laterally on a connecting bridge  340  between the magazine  320  and a handle  350  as well as a battery  360 , the accelerations during a setting process likewise being lower on the connecting bridge than on a main body  330  of the fastener-setting tool  300 . 
       FIG. 22  shows a fastener-setting tool  400  that has two lamps  410  for lighting up the driving region  405  for the fastening element to be set. The lamps  410  are mounted laterally on a connecting bar  470  between a tip  480  of the tool and a handle  450  as well as a battery  460 , the accelerations during a setting process likewise being lower on the connecting bar than on a main body  430  of the fastener-setting tool  400 . 
       FIG. 23  shows a fastener-setting tool  500  that has two lamps  510  for lighting up the driving region  505  for the fastening element to be set. The lamps  510  are mounted laterally on a handle  550  in the area of a battery  560 , where the accelerations during a setting process are likewise being lower than on a main body  530  of the fastener-setting tool  500 . In embodiments that are not shown, the fastener-setting tool has only one lamp or more than two lamps. In some embodiments, the lamps are not arranged laterally, but at the front center on the fastener-setting tool, e.g. on the magazine or on the battery. In additional embodiments that are not shown, the fastener-setting tool has a handle switch, which is automatically actuated when the fastener-setting tool is gripped by this handle. Upon actuating the handle switch, the lamp or lamps are switched on, and when the fastener-setting tool is released, the lamps are automatically switched off. In one variant, the fastener-setting tool has an activation switch, upon the actuation of which the lamps and additional tool functions, such as the control electronics in some cases, are switched on. When the activation switch is again actuated, the lamps are again switched off. 
       FIGS. 24-26  show a fastener-setting tool  600  that has a housing  610 . A belt hook  620  is fastened to the housing  610 . A scaffold hook  630  can be pushed onto the belt hook  620  if necessary so that the fastener-setting tool can be selectively suspended on a belt or scaffolding. The belt hook  620  is preferably made from metal and the scaffolding hook  630  is made of fiber-reinforced plastic. 
       FIGS. 27 and 28  show the scaffold hook  630  pressed onto the belt hook  620 . The scaffold hook  630  has a snap hook  640  for detachably mounting the snap hook  630  on the belt hook  620 . The snap hook  640  for its part has an actuating surface  650  for detaching and removing the scaffold hook  630  from the belt hook  620 .