Patent Publication Number: US-2020298386-A1

Title: Driving-in device

Description:
TECHNICAL FIELD 
     The application relates to an apparatus for driving a fastening element into an underlying surface. 
     BACKGROUND OF THE INVENTION 
     Such apparatuses usually have a piston for transmitting energy to the fastening element. The energy required for this has to be made available in a very short time, which is why, for example in the case of what are known as spring nailers, first of all a spring is tensioned, said spring, during the driving-in operation, imparting the tensile energy to the piston in a sudden burst and accelerating the latter onto the fastening element. 
     The energy released in a sudden burst, with which the fastening element is driven into the underlying surface, causes a recoil, which mechanically loads some components of such apparatuses. When a center of gravity of the apparatus does not lie on the path of movement of the piston or in the extension thereof, the recoil comprises a torque, which causes the entire apparatus to tilt while the fastening element is being driven into the underlying surface. 
     SUMMARY OF THE INVENTION 
     The object of the invention is to improve the fastening quality of the apparatus mentioned at the beginning. 
     The object is achieved by an apparatus for driving a fastening element into an underlying surface, having a center of gravity, an energy transmission element, which is movable between a starting position and a setting position, for transmitting driving-in energy to the fastening element, a piston drive that provides driving-in energy, a housing, and a bolt guide that guides the fastening element while it is being driven in, wherein the bolt guide is mounted on the housing in a rotatable manner with respect to rotation about the center of gravity. As a result of being mounted in a rotatable manner, the bolt guide remains in position on account of its mass inertia even when the rest of the apparatus is already tilting on account of the recoil. This applies for the period in which the fastening element is being driven into the underlying surface. 
     An advantageous embodiment is characterized in that the apparatus has a damping element, which damps a rotary movement of the bolt guide about the center of gravity. 
     An advantageous embodiment is characterized in that the bolt guide has a holder, which is mounted on the housing in a rotatable manner with respect to rotation about the center of gravity. Preferably, the holder comprises a deceleration element for braking the energy transmission element. 
     An advantageous embodiment is characterized in that the bolt guide is mounted on the housing in a rotatable manner through an angular range of at least 2°. Preferably, the angular range extends through at least 3°, particularly preferably through at least 5°. 
    
    
     
       EMBODIMENTS OF THE INVENTION 
       Exemplary embodiments of an apparatus for driving a fastening element into an underlying surface are explained in more detail in the following text by way of examples with reference to the drawings, in which: 
         FIG. 1  shows a side view of a driving-in apparatus, 
         FIG. 2  shows a side view of a driving-in apparatus with the housing open, 
         FIG. 3  shows a partial view of a driving-in apparatus, 
         FIG. 4  shows an oblique view of a bolt guide, and 
         FIG. 5  shows a driving-in apparatus. 
     
    
    
       FIG. 1  shows a side view of a driving-in apparatus  10  for driving a fastening element, for example a nail or bolt, into an underlying surface. The driving-in apparatus  10  has an energy transmission element (not illustrated) for transmitting energy to the fastening element, and a housing  20 , in which the energy transmission element and a drive device (likewise not illustrated) for advancing the energy transmission element are received. 
     The driving-in apparatus  10  also has a handle  30 , a magazine  40  and a bridge  50  connecting the handle  30  to the magazine  40 . The magazine is not removable. Fastened to the bridge  50  are a scaffold hook  60  for hanging the driving-in apparatus  10  on a scaffold or the like, and an electrical energy store in the form of a rechargeable battery  590 . Arranged on the handle  30  are a trigger  34  and a grip sensor in the form of a manual switch  35 . Furthermore, the driving-in apparatus  10  has a guide duct  700  for guiding the fastening element and a pressing device  750  for identifying a distance of the driving-in apparatus  10  from an underlying surface (not illustrated). Alignment of the driving-in apparatus perpendicularly to an underlying surface is assisted by an alignment aid  45 . 
       FIG. 2  shows the driving-in apparatus  10  with the housing  20  open. Received in the housing  20  is a drive device  70  for advancing an energy transmission element that is concealed in the drawing. The drive device  70  comprises an electric motor (not illustrated) for converting electrical energy from the rechargeable battery  590  into rotational energy, a torque transmission device, comprising a gear mechanism  400 , for transmitting a torque of the electric motor to a motion converter in the form of a spindle drive  300 , a force transmission device, comprising a roller train  260 , for transmitting a force from the motion converter to a mechanical energy store in the form of a spring  200  and for transmitting a force from the spring to the energy transmission element. 
       FIG. 3  shows an oblique view of the driving-in apparatus  10  with the housing  20  open. In the housing, the front roller holder  281  can be seen. The deceleration element  600  is kept in its position by the holding ring  26 . The nose  690  has, inter alia, the contact pressure sensor  760  and the unblocking element  720 . The pressing device  750  has the guide duct  700 , which preferably comprises the contact pressure sensor  760 , and the connecting rod  770 . The magazine  40  has the feeding element  740  and the feeding spring  735 . 
     Furthermore, the driving-in apparatus  10  has an unlocking switch  730  for unlocking the guide duct  700  such that the guide duct  700  is removable, for example to make it easier to remove jammed fastening elements. 
       FIG. 4  shows an oblique view of a nose  690  of an apparatus for driving a fastening element into an underlying surface. The nose  690  comprises a guide duct  700  for guiding the fastening element, having a rear end side  701  and a holder  650 , which is arranged so as to be displaceable toward the setting axis relative to the guide duct  700 , for holding a deceleration element (not illustrated). The holder  650  has a bolt receptacle  680  with a feed cutout  704 , through which a nail strip  705  with a multiplicity of fastening elements  706  is feedable to a firing portion  702  of the guide duct  700 . The guide duct  700  serves at the same time as a contact pressure sensor of a pressing device, which has a connecting rod  770 , which is likewise displaced during a displacement of the guide duct  700  and thus indicates contact pressure of the apparatus with an underlying surface. 
       FIG. 5  shows a driving-in apparatus  100  having a center of gravity  110 , an energy transmission element  120 , which is movable between a starting position and a setting position, for transmitting driving-in energy to a fastening element (not shown), a piston drive  130  that provides the driving-in energy, a housing  140 , and a bolt guide  150  that guides the fastening element while it is being driven in. The bolt guide  150  has a holder  160  and is mounted on the housing  140  only via the holder  160 . The holder  160  is connected to the rest of the bolt guide  150  so as to rotate therewith. With respect to rotation about the center of gravity  110 , the holder  160  and thus the bolt guide  150  are mounted on the housing  140  in a rotatable manner. As a result of being mounted in a rotatable manner, the bolt guide remains standing on the underlying surface on account of its mass inertia in the period in which the fastening element is being driven into the underlying surface, and ensures guidance of the fastening element until the fastening element has been driven into the underlying surface. A rotary movement  170 , caused by a recoil, of the driving-in apparatus  100 , in particular of the housing  140 , is compensated and the fastening quality is improved. 
     A driving-in apparatus  100  has a damping element  180 , which is arranged on the side of the holder  160  remote from the center of gravity  110 , in front of the holder  160  and behind a supporting element  145  of the housing  140 , and therefore, during a recoil, a rotary movement of the bolt guide  150  about the center of gravity  110  relative to the housing  140  is damped. For symmetric mounting of the bolt guide  150 , the driving-in apparatus  100  has a further damping element  185 , which is arranged on the side of the holder  160  facing the center of gravity  110  and therefore makes no significant contribution to damping a rotary movement of the bolt guide  150  during a recoil. 
     An angular range through which the bolt guide is mounted on the housing in a rotatable manner depends on a distance between the holder  160  and the supporting element  145  and is 5° in the present case. The holder  160  otherwise comprises a deceleration element  190  for braking the energy transmission element  120 .