Patent Application
20130153621
The application relates to a device for deflecting forces and to a device with a force deflection device for driving fastening elements.
Such force deflection devices are usually constructed as belts, cables or chains that run in a non-constant direction in order to deflect forces and are moved along their extension direction. Both internal and external friction occurs in this process, so the force deflection devices are subject to wear.
Fastener driving 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.
Fastener driving devices are known that are furnished with force deflection devices that are run over deflection pulleys, for example, in order to transfer forces to the piston. It is desirable in this case that the service life of the respective force deflection device at least equals the service life of the fastener driving device.
According to one aspect of the application, a device for deflecting forces comprises a force deflector for deflecting the direction of a force acting on the force deflector, wherein the force deflector comprises a protective layer. The protective layer is used to increase the robustness and/or wear resistance of the force deflector and thus of the force deflection device.
According to a preferred embodiment, the protective layer comprises a plastic. The plastic preferably comprises PVC and/or a plastic based on acrylic. The plastic preferably comprises a synthetic elastomer, especially preferably latex, more particularly natural latex or synthetic latex, a thermoplastic elastomer, a polyurethane, neoprene, a vulcanized elastomer and/or a silicone, particularly a mono-component or a multi-component silicone.
According to a preferred embodiment, the protective layer comprises a lubricant. According to another preferred embodiment, the protective layer covers a surface of the force deflector.
According to a preferred embodiment, a thickness of the protective layer is between 0.2 mm and 0.5 mm. According to a likewise preferred embodiment, a thickness of the protective layer is between 0.1 mm and 0.2 mm. According to another preferred embodiment, a thickness of the protective layer is between 0.01 mm and 0.1 mm.
According to a preferred embodiment, the force deflector comprises a protective layer matrix permeated by reinforcement fibers. The reinforcement fibers especially preferably comprise a stranded wire.
According to a preferred embodiment, the force deflector comprises a fabric or scrim made of weaving or scrim fibers, especially plastic fibers.
The fabric or scrim preferably comprises reinforcement fibers that are different from the fabric or scrim fibers. The reinforcement fibers especially preferably comprise glass fibers, carbon fibers, polyamide fibers, especially aramid fibers, metal fibers, especially steel fibers, ceramic fibers, basalt fibers, boron fibers, polyethylene fibers, high-performance polyethylene fibers, polymer fibers, crystalline fibers, liquid crystalline fibers, polyester fibers, asbestos fibers and/or natural fibers, especially hemp fibers.
According to another preferred embodiment, the force deflector comprises a belt, a cable or a chain.
According to one aspect of the application, the force deflection device is used in a device for driving a fastening element into an underlying surface, the fastener driving device comprising a mechanical energy accumulator for storing mechanical energy, an energy transmission element, movable between a starting position and a set position, for transmitting energy from the mechanical energy accumulator to the fastening element, and a force transmission device for transmitting a force from the energy accumulator to the energy transmission element.
According to another preferred embodiment, the force transmission device, in particular the force deflector, is provided for transmitting a force from the energy accumulator to the energy transmission element.
According to a preferred embodiment, the force deflector is arranged movably relative to the mechanical energy accumulator and/or relative to the energy transmission element. According to another preferred embodiment, the energy transmission element is suitable for transmitting energy from the mechanical energy accumulator to the fastening element.
According to one aspect of the application, the device comprises an energy transmission device for transmitting energy from an energy source to the mechanical energy accumulator. The energy for a driving process is preferably interim-stored in the mechanical energy accumulator in order to be abruptly output to the fastening element. The energy transmission device is preferably suitable for conveying the energy transmission element from the set position to the starting position. In particular, the energy source is preferably an electrical energy accumulator, especially preferably a battery or a rechargeable battery. The device preferably comprises the energy source.
According to one aspect of the application, the energy transmission device comprises a force transmission device for transmitting a force from the energy accumulator to the energy transmission element and/or for transmitting a force from the energy transmission device to the mechanical energy accumulator.
The mechanical energy accumulator is preferably provided to store potential energy. The mechanical energy accumulator especially preferably comprises a spring, in particular a helical spring.
According to one aspect of the application, the force transmission device comprises a force deflector for deflecting the direction of a force transmitted by the force transmission device. The force deflector is preferably arranged movably relative to the mechanical energy accumulator and/or relative to the energy transmission element.
According to one aspect of the application, the force transmission device, in particular the force deflector, more particularly the belt, is fastened to the energy transmission device.
Embodiments of a device for driving fastener elements into an underlying surface and a device for deflecting forces will be described in detail below using examples, with reference to the drawings. Therein:
In a side view,
The fastener driving device 10 further comprises a handle 30, a magazine 40 and a bridge 50 connecting the handle 30 to the magazine 40. The magazine is not removable. An energy accumulator configured as a rechargeable battery 590 and a scaffold hook 60 for suspending the fastener driving device 10 on a scaffold or the like are mounted on the bridge 50. A trigger 34 and a handle sensor configured as a manual switch 35 are arranged on the handle 30. The fastener driving device 10 further comprises a guide channel 700 for guiding the fastening element and a contacting device 750 for recognizing a distance of the fastener driving device 10 from an underlying surface, not shown. Alignment of the fastener driving device perpendicular to an underlying surface is assisted by an alignment aid 45.
A force deflector constructed as a belt 270 of a force transmission unit is fastened to the spindle nut 320 in order to transmit a force from the spindle nut 320 to a mechanical energy accumulator, not shown. For this purpose, the spindle nut 320 comprises an external clamping sleeve 375 in addition to an internal threaded sleeve 370, a gap between the threaded sleeve 370 and threaded sleeve 375 forming a passage 322. The belt 270 is run through the passage 322 and fastened to a locking element 324 by wrapping the belt 270 around the locking element 324 and feeding it back through the passageway 322, where one end 275 of the belt is sewn to the belt 270. Like the passage 322, the locking element is preferably shaped circumferentially as a locking ring.
The belt is preferably configured as a textile belt and comprises a plurality of individual fibers. In an embodiment that is not shown, the force deflector is configured as a cable that preferably comprises a plurality of individual fibers. In another embodiment that is not shown, the force deflector is constructed as a chain of individual chain links.
Transverse to the passage 322, i.e. in the radial direction relative to a spindle axis 311, the locking element 324, together with the formed belt loop 278, has a greater width than the passage 322. Thus the locking element 324 with the belt loop 278 cannot slip through the passage 322, so that the belt 270 is fixed to the spindle nut 320.
Because the belt 270 is fixed to the spindle nut 320, it is guaranteed that a tension force of the mechanical energy accumulator, not shown, constructed in particular as a spring, is deflected by the belt 270 and directly transmitted to the spindle nut 320. The tension force is transmitted by the spindle nut 320 via the spindle 310 and a tie rod 360 to a clutch device, not shown, that holds a piston, likewise not shown. The tie rod comprises a spindle mandrel 365 that is connected fixedly to the spindle 310 at one end and rotatably seated in a spindle bearing 315 at the other end.
The front end 230 of the front spring element 210 is held in the front pulley mount 281, while the rear end 240 of the rear spring element 220 is held in the rear pulley mount. The spring elements 210, 220 are braced at their sides facing one another on support rings 250. Because of the symmetrical arrangement of the spring elements 210, 220, the recoil forces of the spring elements 210, 220 cancel one another, so that the operating comfort of the fastener driving device is improved.
The belt 270 is engaged with the spindle nut 320 and a piston 100, and is placed over the pulleys 291, 292 so that the pulley assembly 260 is formed. The piston 100 is coupled to a clutch device, not shown. The pulley assembly effects a transmission of a relative velocity of the spring ends 230, 240 relative to one another into a speed of the piston 100 by a factor of two. If two identical springs are used, the pulley assembly thus effects a transmission of the speed of each of the spring ends 230, 240 into a speed of the piston 100 by a factor of four.
A spindle drive 300 with a spindle wheel 440, a spindle 310 and a spindle nut arranged inside the rear spring element 220 is also shown, a driving element 330 fixed to the spindle nut also being visible.
As soon as the control unit 500 has recognized by means of a sensor that the piston 100 is in the set position, the control unit 500 initiates a return process in which the piston 100 is conveyed back into its starting position. For this purpose, the motor rotates the spindle 310 in a first rotational direction via the gear unit 400, so that the rotationally fixed spindle nut 320 is moved backward.
The return rods engage in the return pin of the piston 100 and thereby move the piston 100 to the rear as well. The piston 100 carries along the belt 270, but the spring elements 210, 220 are not tensioned thereby, because the spindle nut 320 likewise carries the belt 270 to the rear and thereby the rear pulleys 292 release exactly the same length of belt as the piston pulls in between the front pulleys 291. The belt 270 thus remains substantially load free during the return process.
If the fastener driving device is now lifted off the underlying surface, so that the contacting device 750 is displaced forward relative to the guide channel 700, the control unit 500 initiates a tensioning process in which the spring elements 210, 220 are tensioned. For this purpose, the motor rotates the spindle 310 in a second rotational direction opposite to the first rotational direction via the gear unit 400, so that the rotationally fixed spindle nut 320 is moved forward.
The clutch device 150 holds the coupling insertion part 110 of the piston 100 fixed, so that the length of belt that is drawn in between the rear pulleys 292 by the spindle nut 320 is not released by the piston. The pulley mounts 281, 282 are therefore moved toward one another and the spring elements 210, 220 are tensioned.
The fastener driving device is now ready for a driving process. When a user pulls the trigger 34, the clutch device 150 releases the piston 100, which then transmits the energy of the spring elements 210, 220 to a fastening element and drives the fastening element into the underlying surface.
The force deflector, constructed more particularly as a belt, has a preferably elastic protective layer. The protective layer supports and/or cushions a fabric structure of the force deflector, reduces its internal friction under deformation and avoids buckling of individual fibers under a compressive stress on the force deflector. The protective layer also prevents penetration of dust or similar particles into the belt and thus protects the force deflector from environmental influences or accelerated aging.
In some embodiments, individual fibers or fiber bundles are furnished with the protective layer. In a preferred embodiment, the entire force deflector is furnished with the protective layer.
Internal or external friction is achieved under certain conditions by an alternative or additional protective layer configured as a lubricant. The lubricant preferably comprises an oil, a grease, a solid lubricant such as graphite or MoS2, Teflon, wax or the like.
According to one embodiment, the protective layer is applied to the force deflector or introduced into it by means of an injection molding process. It is possible to furnish the force deflector locally and in a targeted manner with the protective layer, particularly one made from plastic.
According to another embodiment, the protective layer is applied to the force deflector or introduced into the force deflector by means of a two-component cold casting process. The process temperature is preferably roughly 80° C. It is also possible to furnish the force deflector locally and in a targeted manner with the protective layer, particularly one made from polyurethane.
According to another embodiment, the protective layer is applied to the force deflector or introduced into the force deflector by means of an extrusion process. It is also possible to furnish the force deflector continuously with the protective layer, particularly one made from plastic.
According to another embodiment, the protective layer is applied to the force deflector or introduced into the force deflector mechanically, particularly as a protective jacket and/or thermally, particularly as a shrink tube. The protective layer is applied to the force deflector while avoiding air inclusions that may occur in some cases.
According to another embodiment, the protective layer is applied to the force deflector or introduced into the force deflector by means of an immersion process. It is possible to perform the process by machine or manually, continuously or discontinuously in either case.
According to additional embodiments, the protective layer is applied to the force deflector or introduced into the force deflector by vulcanization, by a spraying process, by lamination of a film or by application of an adhesive, especially an elastic adhesive.
The invention was described based on a force deflector for a device for driving a fastening element into an underlying surface. It is hereby pointed out, however, that the force defector according to the invention can also be used for other purposes.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2011088778.4 | Dec 2011 | DE | national |
