Metal deforming – Tool and/or tool holder – Having unitary tool-face
Reexamination Certificate
1999-08-25
2001-07-24
Jones, David (Department: 3725)
Metal deforming
Tool and/or tool holder
Having unitary tool-face
C072S482910, C072S462000
Reexamination Certificate
active
06263721
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an upper tool holder apparatus in a press brake, and more specifically relates to an upper tool holder apparatus in a press brake which is capable of easily detaching an upper tool from an upper table in the press brake so as to exchange it with new one.
2. Description of Relevant Art
A press brake has an upper table (called also as an upper apron) and a lower table (called also as a lower apron). The upper table and the lower table are arranged in an up-and-down direction so as to face each other. One of the upper table and the lower table is suitably driven up and down as a ram.
In order that the press brake having the above structure bends a plate-shaped workpiece, a lower tool (die) is mounted to an upper portion of the lower table, and an upper tool (punch) is mounted to a lower portion of the upper table.
In the above structure, after the workpiece is located on the die, the upper tool and the lower tool are engaged with each other so that the workpiece can be bent.
Incidentally, when a forward end (lower end) of the upper tool provided on the upper table via an upper tool holder apparatus is brought into contact with a V groove formed in the lower tool so that an origin is set in the press brake with a pressure of 2 to 3 t, for example, being applied, the upper tool is broken in the case where a length of the upper tool is short. For this reason, conventionally an operator lifts the upper tool so as to set the origin, and thus this operation is hard.
In addition, since the upper tool is exchanged in the press brake because of a difference in forms of bent workpieces, for example, a lot of upper tool holder apparatuses are mounted to the lower portion of the upper table, and the upper tool holder apparatuses support the upper tool to the upper table detachably.
The conventional upper tool holder apparatus is constituted so as to mount an upper tool clamp to a holder main body mounted to the lower portion of the upper table via a clamping bolt to be oscillated and firmly fix the upper portion of the upper tool inserted between the upper tool clamp and the holder main body via the upper tool clamp by clamping the clamping bolt.
Incidentally, since the above-mentioned conventional upper tool holder apparatus detaches the upper tool from the upper table to exchange it even if the length of the upper tool is short, a lot of the clamping bolts provided in the upper tool holder apparatus should be operated. As a result, this operation is extremely troublesome. Moreover, since a long wedge member is provided in a right-and-left direction between the upper table and lower tool holder apparatus in order to adjust the height of the upper tool, crowning in a longitudinal direction of the upper tool cannot be adjusted fine.
SUMMARY OF THE INVENTION
The present invention has been achieved with such points in view. It therefore is an object of the present invention to provide an upper tool holder apparatus in a press brake which is capable of simplifying an operation for mounting an upper tool clamp to a holder main body and preventing its rotary movement in a right-and-left direction and easily adjusting a height of an upper tool even if a plurality of especially short upper tool holder apparatuses are used with them being arranged adjacently and simultaneously adjusting crowning.
A first aspect of the invention provides an upper tool holder apparatus in a press brake, comprising: a holder main body to be mounted detachably to an upper table in a press brake, the holder main body having an upper tool supporting section for supporting an upper tool a lower portion of the holder main body, the holder main body further having a mounting plate which is pressed and fixed to an upper table at an upper front surface of the holder main body; an upper tool clamp supported to the holder main body so as to be swung on a vicinity of a center portion in an up-and-down direction, the upper tool clamp having an engagement projection at the bottom end of the upper tool clamp, the engagement projection being engaged with a drop-prevention groove provided in the upper tool; a pressing section provided on a lower portion of the upper tool clamp, the pressing section pressing the upper tool against the upper tool supporting section; clamping force applying means for applying a clamping force which clamps the upper tool by pressing an upper portion of the upper tool clamp, the clamping force applying means being provided on the holder main body; clamp operating means for transmitting the clamping force from the clamping force applying means to the upper tool clamp and for releasing the clamping force; and a wedge piece, which is engaged with the drop-prevention groove provided in the upper tool, provided on an upper portion of the engagement projection provided on the lower portion of the upper tool clamp, a force being applied to the wedge piece in a direction where it moves forwards and backwards and it is engaged with the drop-prevention groove, wherein a groove is formed in a front-and-rear direction on a center portion of a right-and-left direction of a lower portion of the mounting plate; and wherein a right-and-left pivoting prevention member which is engaged with the groove is provided on an upper portion of the upper tool clamp.
Therefore, the engagement projection provide on the lower portion of the upper tool clamp is engaged with the drop-prevention groove provided in the upper tool so that the upper tool is securely prevented from dropping out of the upper tool holder apparatus.
In addition, when the clamping force is transmitted from the clamping force applying means to the upper tool clamp by operating the clamp operating means, the upper tool clamp presses and fixes the upper tool firmly to the upper tool supporting section of the holder main body, and thus the upper tool is fixed securely.
Further, since the wedge piece which is engaged with the drop-prevention groove is provided on the upper portion of the engagement projection provided on the lower portion of the upper tool clamp so as to move forward and backward, a clearance between the drop-prevention groove provided in the upper tool and the engagement projection can be reduced, and thus the upper tool is prevented from dropping more securely.
The groove is formed in the front-and-rear direction on the center portion of the right-and-left direction of the lower portion of the mounting plate, and the right-and-left pivoting prevention member which is engaged with the groove is provided on the upper portion of the upper tool clamp. As a result, the upper tool clamp is prevented from pivoting in the right-and-left direction.
A second aspect of the invention provides an upper tool holder apparatus in a press brake characterized in that the mounting plate and the holder main body are integral with each other.
Therefore, the mounting plate and the holder main body are produced integrally so that they are mounted to the upper table easily and more definite accuracy is secured.
A third aspect of the invention provides an upper tool holder apparatus in a press brake characterized in that a height adjustment wedge member for adjusting a height by means of a pushing bolt and a pulling bolt is provided between the upper table and the holder main body.
Therefore, since the height adjustment wedge member for adjusting a height by means of the pushing bolt and the pulling bolt is provided between the upper table and the holder main body, in the case particularly where short upper tool holder apparatuses are used so as to be adjacent to each other, the respective height adjustment wedge members adjust heights from a front side by means of the pushing bolts and the pulling bolts and simultaneously adjust crowning.
REFERENCES:
patent: 5511407 (1996-04-01), Kawano
patent: 5513514 (1996-05-01), Kawano
patent: 5572902 (1996-11-01), Kawano
patent: 5619885 (1997-04-01), Kawano et al.
patent: 5685191 (1997-11-01), Kawano et al.
patent: 5794486 (1998-08-01), Sugimoto e
Amada Company Limited
Blank Rome Comisky & McCauley LLP
Jones David
LandOfFree
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