Metal deforming – With means to drive tool – Including gear-actuated tool support
Reexamination Certificate
1999-04-16
2001-05-29
Jones, David (Department: 3725)
Metal deforming
With means to drive tool
Including gear-actuated tool support
C072S391400, C029S243526
Reexamination Certificate
active
06237390
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a riveting apparatus.
A riveting apparatus of that kind is known, for instance, from EP-A-0527414. Great riveting forces can be realized by riveting apparatus of that kind, in which the gearing is usually formed by a ball screw drive. In order to perform a riveting process, a blind rivet is inserted in a manner known per se into a mouthpiece of the riveting means. For setting the rivet, the rivet pin is drawn in the longitudinal direction into the rivet sleeve by means of the ball screw drive in the riveting means. The rivet pins then breaks. The required movement in the longitudinal direction of the rivet pin can be achieved by the ball screw drive of the riveting means. After setting the rivet, the direction of rotation of the motor is changed to put the riveting means with the ball screw drive back to its starting position. in riveting apparatus of that kind, the high energy consumption, however, proves to be disadvantageous. Since riveting apparatus of that kind are usually operated by a rechargeable battery, a low energy consumption is especially important to thereby prolong the possible operating time of the riveting apparatus.
SUMMARY OF THE INVENTION
Hence, it is the object of the invention to lower the energy consumption of a riveting apparatus of the above-mentioned kind.
The object is solved by the invention in that at least one flywheel is provided which is releasably connected to the motor shaft or a gearing shaft of the gearing via a clutch.
This solution is simple and has the advantage that, during permanent operation of riveting apparatus of that kind, the energy stored in the flywheel may be used for carrying out the riveting process. Thereby, the energy consumption can be significantly reduced. The flywheel may be used for accelerating the start of the motor after each riveting process, or to reduce power peaks during the riveting process and the voltage peaks for the motor generated thereby. This is in particular advantageous during permanent operation of the riveting apparatus. The flywheel keeps on rotating between the individual riveting processes and is decoupled from the motor shaft. At the beginning of the riveting process, the flywheel and the motor shaft are joined by means of a clutch. In this manner, the energy of the flywheel can be utilized. For the first time, the clutch enables to use a flywheel for a riveting apparatus having a ball screw drive. Since for re-transferring the riveting means after the riveting process, the engine must be operated in reverse direction with respect tot he riveting process, the flywheel may be decoupled from the motor during this period of time. The flywheel therefore keeps its direction of rotation. As an alternative, the flywheel can also be coupled in an analog manner with a gearing shaft of the gearing. Riveting apparatus which, for instance, comprise a ball screw drive, have a constant ratio of transmission between the motor shaft and the riveting means. Basically, it is also conceivable to use the invention in such riveting apparatus in which the drive is formed by a crank mechanism.
In an advantageous embodiment of the invention, a gearing with a ratio of transmission can be provided between the flywheel and the motor shaft, in a manner that the revolution speed of the flywheel is greater than the revolution speed of the motor shaft. Thereby, smaller flywheels can be arranged in the riveting apparatus at an equal flywheel effect. The undesired torque around the flywheel axle during start-up of the flywheel can also be reduced thereby.
It may be an advantage if the ratio of transmission is selected in a manner that the revolution speed of the flywheel is approximately twice as high as the revolution speed of the motor shaft.
According to an advantageous development of the invention, the clutch may be formed as a non-positive clutch, preferably as a frictional clutch.
It may be an advantage if the clutch is operable electromagnetically. A clutch of that kind can be realized in a simple manner.
As an alternative, the clutch may be formed as a positive clutch, preferably as a claw clutch. Thereby, an especially robust clutch can be realized.
In an advantageous development of the invention, a brake may be provided, by means of which the flywheel can be braked. This brake prevents an undesired long after-running of the flywheel. This brake may be operated by the operator, for instance, by a switch attached in the housing of the riveting apparatus.
It may prove to be advantageous if the flywheel can be braked by short-circuiting the drive motor. Then the brake can be realized in a simple manner by using the already existing components.
In an advantageous development of the invention, the flywheel may be coupled with the motor for re-charging a rechargeable battery of the riveting apparatus in order to operate the motor as a generator. Thereby, the power consumption of the riveting apparatus may be reduced.
An advantage may also be if two flywheels are provided, which have directions of rotation opposite one to another. Thereby, the torques generated by the flywheel can be reduced, since the two opposed flywheels substantially mutually compensate for their torques.
Moreover, it may turn out to be an advantage if a reverse gear is provided by means of which the direction of rotation of the flywheel with respect to the motor shaft can be changed. Then the flywheel may also be used for carrying out the back-stroke of the riveting device.
Moreover, the invention claims a method for operating a riveting apparatus, in which during the setting stroke of the riveting means, the flywheel is coupled to the motor shaft and is decoupled therefrom during the backstroke of the riveting means. Thereby, the energy consumption for setting the rivets can be significantly reduced, in particular during permanent operation.
It may turn out to be an advantage when, upon termination of the riveting process, the flywheel is coupled to the motor shaft of the drive motor to operate the drive motor as a generator. Thereby, the current generated by the generator may, for instance, be supplied to a rechargeable battery to enable an extended work period by means of the rechargeable battery.
The invention will now be described in detail by means of two embodiments.
REFERENCES:
patent: 2753072 (1956-07-01), Mitchell
patent: 3119507 (1964-01-01), Burritt
patent: 3359777 (1967-12-01), Lee
patent: 3410128 (1968-11-01), Sauter et al.
patent: 4085337 (1978-04-01), Moeller
patent: 5131255 (1992-07-01), Fushiya et al.
patent: 5473805 (1995-12-01), Wile
patent: 0527414 (1995-05-01), None
Honsel Michael H.
Perkins Dallas B.
Coudert Brothers
Jones David
M. H. Honsel Beteilgungs GmbH
LandOfFree
Riveting apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Riveting apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Riveting apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2513883