Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25C—HAND-HELD NAILING OR STAPLING TOOLS; MANUALLY OPERATED PORTABLE STAPLING TOOLS
  • B25C1/00—Hand-held nailing tools; Nail feeding devices
  • B25C1/06—Hand-held nailing tools; Nail feeding devices operated by electric power
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25C—HAND-HELD NAILING OR STAPLING TOOLS; MANUALLY OPERATED PORTABLE STAPLING TOOLS
  • B25C1/00—Hand-held nailing tools; Nail feeding devices
  • B25C1/04—Hand-held nailing tools; Nail feeding devices operated by fluid pressure, e.g. by air pressure

Definitions

• the present disclosure relates to fastener driving apparatuses, and, more particularly, to such fastener or staple driving mechanisms that require operation as a hand tool.
• Electromechanical fastener driving apparatuses also referred to herein as a "driver,” “gun” or “device" known in the art often weigh generally less than 15 pounds and may be configured for an entirely portable operation.
• These power-assisted means of driving fasteners can be either in the form of finishing fastener systems used in baseboards or crown molding in house and household projects, or in the form of common fastener systems that are used to make walls or hang sheathing onto same.
• These systems can be portable (i.e., not connected or tethered to an air compressor or wall outlet) or non-portable.
• the most common fastener driving apparatus uses a source of compressed air to actuate a guide assembly to push a fastener into a substrate.
• this is a very functional system and allows rapid delivery of fasteners for quick assembly.
• a disadvantage is that it does however require that the user purchase an air compressor and associated air-lines in order to use this system.
• a further disadvantage is the inconvenience of the device being tethered (through an air hose) to an air compressor.
• FIG. 1 Another commercially available solution is a fastener gun that uses electrical energy to drive a stapler or wire brad.
• Such units typically use a solenoid to drive the fastener (such as those commercially available under the ArrowTM name or those which use a ratcheting spring system such as the RyobiTM electric stapler).
• These units are limited to short fasteners (typically 1" or less), are subject to high reactionary forces on the user and are limited in their repetition rate. The high reactionary force is a consequence of the comparatively long time it takes to drive the fastener into the substrate.
• the ability to drive longer fasteners or larger fasteners is severely restricted, thus relegating these devices to a limited range of applications.
• a further disadvantage of the solenoid driven units is they often must be plugged into the wall in order to have enough voltage to create the force needed to drive even short fasteners.
• a final commercially available solution is to use a flywheel mechanism and clutch the flywheel to an anvil that drives the fastener.
• Examples of such tools can be found under the DewaltTM name. This tool is capable of driving the fasteners very quickly and in the longer sizes.
• the primary drawback to such a tool is the large weight and size as compared to the pneumatic counterpart. Additionally, the drive mechanism is very complicated, which gives a high retail cost in comparison to the pneumatic fastener gun.
• the first technique is based on a multiple impact design.
• a motor or other power source is connected to an impact anvil through either a lost motion coupling or other device. This allows the power source to make multiple impacts on the fastener to drive it into the workpiece.
• the disadvantages in this design include increased operator fatigue since the actuation technique is a series of blows rather than a single drive motion.
• a further disadvantage is that this technique requires the use of an energy absorbing mechanism once the fastener is seated. This is needed to prevent the anvil from causing excessive damage to the substrate as it seats the fastener.
• the multiple impact designs are not very efficient because of the constant motion reversal and the limited operator production speed.
• 172, 121 includes the use of potential energy storage mechanisms (in the form of a mechanical spring).
• the spring is cocked (or activated) through an electric motor. Once the spring is sufficiently compressed, the energy is released from the spring into the anvil (or fastener driving piece), thus pushing the fastener into the substrate.
• drawbacks exist to this design include the need for a complex system of compressing and controlling the spring, and in order to store sufficient energy, the spring must be very heavy and bulky. Additionally, the spring suffers from fatigue, which gives the tool a very short life. Finally, metal springs must move a significant amount of mass in order to decompress, and the result is that these low-speed fastener drivers result in a high reactionary force on the user.
• a further disadvantage presented is that the fastener must be fed once the anvil clears the fastener on the backward stroke. The amount of time to feed the fastener is limited and can result in jams and poor operation, especially with longer fasteners.
• a further disadvantage to the air spring results from the need to have the ratcheting mechanism as part of the anvil drive. This mechanism adds weight and causes significant problems in controlling the fastener drive since the weight must be stopped at the end of the stroke. This added mass slows the fastener drive stroke and increases the reactionary force on the operator. Additionally, because significant kinetic energy is contained within the air spring and piston assembly the unit suffers from poor efficiency. This design is further subject to a complicated drive system for coupling and uncoupling the air spring and ratchet from the drive train which increases the production cost and reduces the system reliability.
• US Patent No. 5,720,423 again teaches of an air spring that is compressed and then released to drive the fastener.
• the drive or compression mechanism used in this device is limited in stroke and thus is limited in the amount of energy which can be stored into the air stream.
• this patent teaches use of a gas supply which preloads the guide assembly at a pressure higher than atmospheric pressure.
• the compression mechanism is bulky and complicated.
• the timing of the motor is complicated by the small amount of time between the release of the piston and anvil assembly from the drive mechanism and its subsequent re-engagement.
• US Patent No, 5,720,423 teaches that the anvil begins in the retracted position, which further complicates and increases the size of the drive mechanism. Furthermore, because of the method of activation, these types of mechanisms as described in US Patent Nos. 5,720,423 and 4,215,808 must compress the air to full energy and then release off the tip of the gear while under full load. This method of compression and release causes severe mechanism wear. As will be discussed below, the present disclosure overcomes these and other limitations in the prior art use of air springs.
• a third means for driving a fastener includes the use of flywheels as energy storage means.
• the flywheels are used to a hammering anvil that impacts the fastener.
• This design is described in detail in US Patent Nos. 4,042,036, 5,511,715, and 5,320,270.
• One major drawback to this design is the problem of coupling the flywheel to the driving anvil.
• This prior art teaches the use of a friction clutching mechanism that is both complicated, heavy and subject to wear. Further limiting this approach is the difficulty in controlling the energy in the fastener system. The mechanism requires enough energy to drive the fastener, but retains significant energy in the flywheel after the drive is complete. This further increases the design complexity and size of such prior art devices.
• Patent No. 8,079,504 which uses a compression on demand system with a magnetic detent.
• This system overcomes many of the advantages of the previous systems but still has its own set of disadvantages which include the need to retain a very high pressure for a short period of time. This pressure and subsequent force necessitate the use of high strength components and more expensive batteries and motors.
• the fuel powered mechanisms have loud combustion reports and combustion fumes.
• the multiple impact devices are fatiguing and are noisy.
• a fastener driving apparatus which derives its power from an electrical source, preferably rechargeable batteries, and uses a motor to actuate a spring (such as a gas spring, for example).
• a spring such as a gas spring, for example.
• the piston of the gas spring commences movement, accelerating an anvil and/or anvil assembly.
• the anvil assembly preferably has a mass that is greater than the weight of the piston, the contact of the piston with the anvil causes the anvil to move.
• the piston comes to rest on a bumper but the anvil assembly continues to move toward and into contact with a fastener such that the anvil drives the fastener.
• the effective mass differential between the piston and the anvil facilitates sufficient energy being transferred to the anvil for driving a fastener.
• a return spring or other return mechanism is incorporated to return the anvil, after the anvil drives the fastener, to a position where the anvil and/or anvil assembly may again be operatively contacted by the piston for another drive by the anvil.
• test results show conversion efficiencies (potential energy to kinetic energy in the drive anvil) of over 80%, which is far better than the 65% obtained by the apparatus of the '504 patent.
• the fastener driving cycle of the apparatus disclosed herein may start with an electrical signal, after which a circuit connects a motor to the electrical power source.
• the motor is coupled to the gas spring through a drive mechanism.
• the mechanism alternatively (1) actuates the piston of the gas spring and (2) decouples from the piston.
• the drive mechanism may move the piston to increase potential energy stored within the gas spring.
• the mechanism decouples from the piston to allow the accumulated potential energy within the gas spring to act on and actuate the piston.
• the piston thereupon moves and causes the anvil assembly to move and drive a fastener.
• a spring or other return mechanism is operatively coupled to the anvil and anvil assembly to return the anvil to an initial position.
• at least one bumper is disposed within the gas spring or outside the gas spring to reduce the wear on the piston.
• another bumper is used to reduce the wear on the anvil assembly that otherwise may occur in operation of the fastener driving apparatus.
• the mass of the anvil and anvil assembly is at least equal to the moving mass of the gas spring, and more preferably, at least 1.2 times the moving mass of the gas spring.
• the stroke or movement of the piston is less than one half the total movement of the anvil and anvil assembly. Further preferred is that the movement of the piston results in a volume decrease within the gas spring of less than 20% of the initial volume (which thus reduces losses from heat of compression.)
• a sensor and a control circuit are provided for determining at least one position of the anvil, anvil assembly, and/or drive mechanism to enable the proper timing for stopping the operational cycle of the apparatus. Further, this information can be used to detect a j am condition for proper recovery.
• the piston launches the anvil and/or anvil assembly prior to or within less than 20% of the total fastener stroke. This results in an improved safety profile in the event of a jam, as the anvil and anvil assembly will have dissipated its kinetic energy, thus allowing the user to fix the jam without having potential energy remaining in the anvil and anvil assembly.
• Figure 1 shows a cutaway view of a fastener driving apparatus, in accordance with an exemplary embodiment of the present disclosure
• Figure 2 shows a cutaway view of a fastener driving apparatus, in accordance with an exemplary embodiment of the present disclosure wherein the gas spring is being compressed;
• Figure 3 shows a cutaway view of a fastener driving apparatus, in accordance with an exemplary embodiment of the present disclosure wherein the gas spring is releasing the drive anvil;
• Figure 4 shows a cutaway view of a fastener driving apparatus, in accordance with an exemplary embodiment of the present disclosure wherein the anvil assembly has separated from the gas spring and is driving the fastener;
• Figure 5 shows a cutaway view of a fastener driving apparatus, in accordance with an exemplary embodiment of the present disclosure wherein the gas spring has retumed to a starting position, and .
• Figure 6 shows a piston flange of a fastener driving apparatus, in accordance with an exemplary embodiment of the present disclosure.
• the present disclosure provides for a fastener driving apparatus 100.
• the apparatus 100 comprises a power source 10, a control circuit 20, a motor 30, a gas spring 40, a drive mechanism 50, an anvil assembly 60, and an anvil 62.
• the apparatus 100 may further comprise an anvil return mechanism 64 and at least one bumper 70.
• the gas spring 40 includes a piston 42, which piston 42 is at least partially disposed within a sealed chamber 44, and which piston 42 is selectively actuated by the drive mechanism 50.
• a bumper 72 is preferably disposed within the gas spring 40 to absorb a portion of the force of impact of the piston 42.
• the gas spring 40 further comprises a nose portion 46 (which nose portion may be a part of or coupled to the piston) and which nose portion 46 extends out of the chamber and which makes operative contact with the anvil 62 and/or anvil assembly 60 during a portion of the operational cycle of the apparatus 100.
• the piston 42 also comprises a flange 48 that is at or near the end of the piston that is distal to the anvil and anvil assembly, which flange 48 retains the piston 42 within the gas spring 40.
• the flange extends away from and beyond the circumference of the piston and may also impact the bumper 72 to absorb the energy of the gas spring during a portion of the stroke.
• the flange 48 further comprises an opening or open area 49 to allow air or gas to flow from one side of the piston or piston flange to another side of the piston or piston flange.
• the area of the opening or open area is least 5% of the area of the cross-sectional area of the interior of the gas piston.
• the drive mechanism 50 may comprise, in an embodiment, a rack gear with intervals of teeth and no teeth.
• the drive mechanism 50 preferably comprises a cam-driven mechanism 52 as illustrated in the figures.
• the drive mechanism 50 may comprise an interrupted friction wheel. It will be apparent that the drive mechanism 50 is configured to permit transition from engagement with the gas spring 40 to disengagement from the gas spring 40.
• the drive mechanism 50 is operatively coupled to the gas spring 40, and in an particular embodiment, to the piston 42 such that the drive mechanism 50 may alternate in actuating the piston 42 (when the gear teeth or cam is engaged, for example, and as shown in Figures 1 and 2) and in refraining from applying a drive force on the piston (as shown in Figures 3 and 4).
• the drive mechanism 50 preferably acts directly upon the anvil assembly 60, which anvil assembly 60 is at least operatively coupled to and moves the piston 42 to store potential energy (as described elsewhere herein.)
• the drive mechanism 50 engages and actuates the piston 42 (and/or anvil assembly 60) to store potential energy within the gas spring 40, which actuation of the piston 42 may be referred to as an "energized position" of the piston 42.
• the initial pressure (before the drive mechanism 50 actuates the piston 42) within the gas spring 40 is at least 40 psia. In another embodiment, the initial pressure within the gas spring 40 is at least 200 psi.
• the configuration and design of the gas spring 40 are such that the pressure increase during the piston movement is less than 30% of the initial pressure, and in an embodiment, less than 50% of the initial pressure, which allows the drive mechanism 50 to operate at a more constant torque, thus improving the motor efficiency.
• the drive mechanism 50 thereafter disengages the piston 42 (and/or anvil assembly 60), allowing potential energy to act on the piston 42 and cause the piston 42 to move and act on the anvil 62 and/or anvil assembly 60 (as will be described in further detail below).
• the drive mechanism 50 is timed and/or configured to prevent further engagement with the gas spring 40 (and/or anvil assembly 60) until after the anvil 62 and/or anvil assembly 60 has returned to an approximate starting position.
• the drive mechanism 50 may thereafter again act on the piston 42 (and/or anvil assembly 60) to again store potential energy within the gas spring 40 and may thereafter again temporarily cease to act on the piston 42 (and/or anvil assembly 60) to allow potential energy to instead act on the piston 42.
• the stroke of the piston 42 is less than stroke of the anvil assembly 60.
• the anvil 62 and/or anvil assembly 60 is operatively coupled to the gas spring
• the mass of the anvil 62 is at least two times the mass of the piston 42.
• the piston 42 has a mass of 90 grams and the anvil 62 has a mass of 250 grams.
• the piston 42 is hollowed out to lighten its mass and further may be constructed of lightweight materials such as hard anodized aluminum, plastics or the like.
• the anvil 62 may be operatively coupled to a guide, shaft, or other structure that limits and guides the range of motion of the anvil 62.
• a sensor 90 is provided for determining at least one position of the anvil, anvil assembly, and/or drive mechanism to enable the proper timing for stopping the operational cycle of the apparatus. Further, this information can be used to detect a j am condition for proper recovery .
• At least one bumper 70 may be disposed on the apparatus 100 for absorbing a portion of the force of impact of the piston 42 within the gas spring 40 or of the anvil 62 and/or anvil assembly 60, to reduce wear and tear on the components of the apparatus 100.
• the at least one bumper 70 may be of an elastic material, and may be disposed on the apparatus 100 at any position where it is capable of absorbing a portion of the force of impact by the piston 42 or the anvil 62.
• the anvil 62 further comprises a return mechanism 64 to enable to the anvil 62 to return to a position where it can be again contacted or acted on by the gas spring 40.
• the return mechanism 64 is a return spring that is disposed on or in the guide or shaft that constrains the anvil 62, which return spring would be disposed nearer the end or portion of the anvil 62 that is distal to the gas spring 40.
• the return spring may be disposed with respect to the anvil 62 such that motion of the anvil 62 toward a fastener to be driven also causes the spring to compress, and after the anvil 62 has reached the end of its drive stroke, the compressed return spring decompresses to actuate the anvil 62 to the anvil's earlier or original position.
• the fastener driving apparatus 100 disclosed herein comprises a spring in place of the gas spring and piston.
• the spring may comprise a mechanical spring, a gas spring, an elastomer spring or an elastomer, for example.
• the apparatus further comprises a drive mechanism, an anvil assembly, an anvil, an anvil return mechanism, and at least one bumper.
• the drive mechanism may comprise, in an embodiment, a rack gear with intervals of teeth and no teeth.
• the drive mechanism preferably comprises a cam-driven mechanism as illustrated in the figures. It will be apparent that the drive mechanism is configured to permit transition from engagement with the spring to disengagement from the spring.
• the drive mechanism is operatively coupled to the spring such that the drive mechanism may alternate in actuating the spring (when the gear teeth or cam is engaged, for example) and in refraining from applying a drive force on the such that other forces are able to act on and actuate the spring.
• the drive mechanism preferably acts directly upon the anvil assembly, which anvil assembly is at least operatively coupled to the spring and moves the spring to store potential energy (as described elsewhere herein.)
• the drive mechanism engages and actuates the spring
• the drive mechanism thereafter disengages the spring (and/or anvil assembly), allowing potential energy to act on the spring and cause the spring to move and act on the anvil and/or anvil assembly (as will be described in further detail below).
• the drive mechanism is timed and/or configured to prevent further engagement with the spring (and/or anvil assembly) until after the anvil and/or anvil assembly has returned to an approximate starting position.
• the drive mechanism may thereafter again act on the spring (and/or anvil assembly) to again store potential energy within the spring and may thereafter again temporarily cease to act on the spring (and/or anvil assembly) to allow potential energy to instead act on the spring.
• the stroke of the spring is less than stroke of the anvil assembly.
• the anvil and/or anvil assembly is operatively coupled to the spring, such that when the spring is released from the drive mechanism the force from the spring is imparted onto the anvil and/or anvil assembly, causing the anvil and/or anvil assembly to move in a direction and to release (or be launched) away from the spring and drive a fastener, for example.
• the mass of the anvil is at least two times the mass of the spring.
• the spring has a mass of 90 grams and the anvil has a mass of 250 grams.
• the anvil may be operatively coupled to a guide, shaft, or other structure that limits and guides the range of motion of the anvil.
• At least one bumper may be disposed on the apparatus for absorbing a portion of the force of impact of the spring, to reduce wear and tear on the components of the apparatus.
• the at least one bumper may be of an elastic material, and may be disposed on the apparatus at any position where it is capable of absorbing a portion of the force of impact by the spring.
• the anvil further comprises a return mechanism to enable to the anvil to return to a position where it can be again contacted or acted on by the spring.
• the return mechanism is a return spring that is disposed on or in the guide or shaft that constrains the anvil, which return spring would be disposed nearer the end or portion of the anvil that is distal to the spring that causes the anvil to drive a fastener. After the spring causes the anvil to move to drive a fastener, and after or in connection with the anvil impacting and driving a fastener, the return mechanism imparts a force on the anvil to cause the anvil to return to a position where it may again be operatively acted upon by the spring.
• the return spring may be disposed with respect to the anvil such that motion of the anvil toward a fastener to be driven also causes the return spring to compress, and after the anvil has reached the end of its drive stroke, the compressed return spring decompresses to actuate the anvil to the anvil's earlier or original position.
• the gas spring, mechanical spring and elastomer are capable of generating a relatively high amount of force in a small amount of space such that the size of the apparatus may be smaller than other fastener drivers.
• the motor of the apparatus is not significantly overworked or over torqued, thus leading to a longer useful life of the apparatus.
• this invention has an improved safety profile. For example, if a nail becomes jammed, the potential energy of the air spring does not act directly on the fastener and thus while the user removes the fastener, there is reduced potential for injury. It was a further unexpected discovery of the present disclosure that the apparatus has an improved recoil force as opposed to conventional and or the inventor's prior fastener inventions.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Portable Nailing Machines And Staplers (AREA)

Applications Claiming Priority (2)

Publications (3)

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Family Applications (1)

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• 2016
  • 2016-07-25 EP EP16828681.3A patent/EP3325217B1/de active Active
  • 2016-07-25 WO PCT/US2016/043825 patent/WO2017015654A1/en active Application Filing
  • 2016-07-25 CA CA2993187A patent/CA2993187C/en active Active
  • 2016-07-25 ES ES16828681T patent/ES2874088T3/es active Active
  • 2016-07-25 AU AU2016297660A patent/AU2016297660B2/en not_active Ceased

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