Metal deforming – By use of non-deforming work-gripping clamp and relatively... – Clamp structure constitutes sole initial metal-deforming...
Reexamination Certificate
1999-01-05
2001-05-08
Crane, Daniel C. (Department: 3725)
Metal deforming
By use of non-deforming work-gripping clamp and relatively...
Clamp structure constitutes sole initial metal-deforming...
C072S319000
Reexamination Certificate
active
06227028
ABSTRACT:
The present invention relates to a device for adapting the size of a jaw.
BACKGROUND OF THE INVENTION
A jaw is a machine tool part designed for machining elements in the form of sheets, such as sheet metal, that holds the machined sheet firmly. Jaws are found, for example, in drawing machines and bending brakes.
The size of the jaw must be adapted to the size of the sheet metal to be machined and to the operation carried out. To be able to machine pieces of sheet metal of different sizes on the same machine tool, it is necessary to be able to change the size of the jaw.
Adapting the entire jaw to the size of the sheet metal to be machined without manual intervention is known.
The main drawback of conventional systems for adapting the size of a jaw automatically is that this operation takes a relatively long time, thus limiting productivity in relation to flexibility. The time required to machine the sheet metal is less than the time taken to adapt the jaw in known systems. Hence, a user will endeavor to fabricate several parts with the same size before changing the size of the jaw.
Moreover, for optimization reasons, manufacturers recommend first running operations requiring a short jaw on the machine tool equipped with a modular jaw, and subsequently, running operations requiring a long jaw. The user, thus, has to adjust the machining sequence to these constraints.
SUMMARY OF THE INVENTION
The goal of the invention is to furnish a device enabling the size of a jaw to be adapted very rapidly to improve the flexibility of a machine tool designed to receive this jaw and enable the various machining operations to be conducted in any sequence without thereby affecting cycle time.
For this purpose, the device it proposes consists of a frame provided with guide means, jaw modules designed to move along the guide means, means for independently locking each jaw module into a given position, a magazine of end modules located near each end of the guide means and gripping and handling means for gripping an end module in a magazine to position the end module against a jaw module and withdraw an end module positioned against a jaw module to replace it in a magazine.
The configuration of the jaw can then be changed very rapidly. One need only move the jaw modules not used for making a predefined bend toward the ends of the guide means and regroup the jaw modules needed for this bending operation at the center of the guide means then, with the aid of gripping means, bring an end module to each end of the group of jaw modules to form a jaw of the desired size for making the bend. All these operations can be conducted rapidly, because the jaw modules can move at the same time as the end modules.
Advantageously, a module, called a central module, is mounted in a fixed position relative to the frame. The movable jaw modules are located on each side of the central module. The jaw modules on a given side of the central module are all similar, and the jaw modules on one side of the central module have a different length in the direction of the guide means than those located on the other side of the central module. The central module then serves as a stop when the jaw modules are being moved. The different lengths of the jaw modules on one side and on the other side of the central module enables a greater variety of different jaw lengths to be offered. If, for example, all the jaw modules and the central module are 100 mm long, the assembly formed by the jaw modules and the central module will always be a multiple of 100 mm long. On the other hand, if the jaw modules on one side are 100 mm long and those on the other side are 50 mm or 150 mm long, it will also be possible to have total lengths that are multiples of 50 mm. Of course, other values and other length ratios are possible.
In a preferred embodiment, the guide means are comprised of at least one rectilinear rail integral with the frame. In this case, advantageously, the jaw modules are mounted on two parallel rails between which is guided a drive bar, and the locking means enable each jaw module, independently of the others, to be coupled to either the drive bar or the guide rails. To move the jaw modules, one need only join them to the drive bar and move the latter with these modules. The other jaw modules that are not supposed to move remain coupled to the frame. To shift all the jaw modules that are to be moved, one need only move the drive bar once in one direction with the modules moving in the same direction, then move the jaw modules that are supposed to move, in the other direction.
In a preferred embodiment, each jaw module has a locking part that can move perpendicularly to the guide rails. The locking part has a U-shaped section perpendicularly to the guide rails with the end of one arm of the U being in a lengthwise groove provided in a rail. The other arm end of the U is opposite the other guide rail and the drive bar projects between these two arms. A spring pretensions the locking part in one direction making the locking part coupled to the frame or the drive bar. An actuator is provided to act against the spring to make the locking part coupled to the drive bar or the frame.
To drive the drive bar, it is provided with a rack meshing with a gear driven by a motor. Other means are of course possible: the bar can, for example, be connected to an actuator or to a linear motor.
In the device according to the invention, the gripping and handling means may be a gripper moving lengthwise on the frame. Other solutions such as a manipulator robot are also possible.
The invention also proposes using a device such as that described above on a machine designed to make bends in a piece of sheet metal, having two jaws and one bending tool. In such a machine, there is no point in having two modular jaws; a single jaw is generally sufficient.
Such a machine, or bending brake, can adapt the size of its jaw during the time taken for the bent piece of metal to leave and the metal to be bent to take its place. For sheets to be bent on two opposite sides, the invention proposes a machining center, characterized by having two bending brakes according to the invention, the two bending brakes being opposite each other and able to move toward or away from each other, and by a conveyor designed to convey the pieces of sheet metal being located between the two bending brakes. The conveyor can also be provided with a central rotator which is placed between the two bending brakes and is able to turn the sheets to be bent on four sides—or more.
In any event, the invention will be properly understood with the aid of the description that follows with reference to the attached schematic drawings that show a device according to the invention as a nonlimiting example.
REFERENCES:
patent: 4532792 (1985-08-01), Hongo
patent: 4656861 (1987-04-01), Koyama
patent: 4722214 (1988-02-01), Hayashi et al.
patent: 4765171 (1988-08-01), Klingesberger
patent: 5168745 (1992-12-01), Miyagawa
patent: 0 332 221 A2 (1989-09-01), None
patent: 0 682 996 A2 (1995-11-01), None
patent: 0 713 734 (1996-05-01), None
patent: 148021 (1983-09-01), None
Crane Daniel C.
DUO Forma
Oliff & Berridg,e PLC
LandOfFree
Device for adapting the size of a machine tool jaw does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Device for adapting the size of a machine tool jaw, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Device for adapting the size of a machine tool jaw will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2545911