Cutting – Processes – With reorientation of work between cuts
Reexamination Certificate
2000-04-28
2003-05-13
Dexter, Clark F. (Department: 3724)
Cutting
Processes
With reorientation of work between cuts
C083S054000, C083S167000, C083S180000, C083S184000, C083S192000, C083S195000, C083S456000, C083S687000
Reexamination Certificate
active
06561065
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to an apparatus, system, and method for punching holes in the walls of elongate hollow bodies. In particular, the invention relates to an apparatus, system, and method for die punching holes in the walls of elongate hollow bodies by use of an expandable die which is insertable into the elongate hollow body and positionable anywhere along the length of the elongate hollow body.
2. Description of the Prior Art
There has long existed a need to be able to economically and reliably die punch holes at desired locations along the length of elongate hollow bodies. For example, in the architectural glass industry, elongate hollow bodies in the form of aluminum mullions up to thirty feet in length are used for supporting panels of architectural glass. Cross-members and associated hardware are attached to the mullions by way of fasteners such as screws and bolts. The holes in the mullions for receiving the fasteners must be precisely located and reliably sized to provide for the fit and structural integrity necessary for the assembled architectural structure. Moreover, the mullion surface is often exposed to view making its surface finish an aesthetically important feature.
Two methods have been commonly employed for making the holes in such mullions. One way is to make the holes by use of a rotary tool such as drilling or routering. Rotary tool hole-making can be done in a shop, but is time consuming and produces shavings which present cleanup problems. Rotary tool hole-making can also be done in the field, but the hole location is not as precise and the sizing as reliable as they are for shop-made holes. Furthermore, the surface of the mullion may become scratched or dented during such hole-making processes. Moreover, even when done in a shop, rotary tool hole-making is a relatively slow and expensive process and the hole shape is limited to being generally round.
The other commonly used way of making holes in a mullion is to use die punching in conjunction with an open body such as an open-side extrusion. This method requires that the mullion consists of two or more longitudinal pieces that may be joined together during service, but which during hole punching are separate and apart so that each piece has at least one open side. The open side permits the piece to be fit over a conventional punch die anvil. This method allows reliably sized holes of a desired shape to be die punched at precise locations along the length of the mullion. However, this method is not suitable for use with a single-piece elongate hollow body and the use of a multi-piece assembly is more expensive than the use of a single-piece extrusion.
There are other methods which have also been employed in the past for punching holes into elongate hollow bodies, but each of these has its own drawbacks. For example, Duce, U.S. Pat. No. 4,744,276, issued May 17, 1988, describes a method and an apparatus which use an exterior punch in combination with a die contained in a solid mandrel. This solid mandrel is inserted into the interior of a square tube with very little clearance. This method has the disadvantage that the mandrel must be sized to have a cross-section which approximates the interior cross-sectional dimensions of the elongate hollow body closely enough to avoid any collapse or deformation of the hollow body during the pressing operation. Thus, a separate mandrel is needed for each hollow body interior cross-section. Another disadvantage is that size variances and straightness irregularities in the interior of the elongate hollow body may make it difficult or impossible to employ this method. Woodward, U.S. Pat. No. 3,209,575, issued Oct. 5, 1965, also teaches the use of a solid mandrel, and, thus, is similarly disadvantaged.
Coulon et al., U.S. Pat. No. 3,698,274, issued Oct. 17, 1972, uses an exterior punch in combination with a die contained within a longitudinally split mandrel. The ends of the split-mandrel which are remote from the die are fixedly anchored. A wedge is forced between the two mandrel halves at their ends which are proximate to the die so as to make them engage the top and bottom interior surfaces of the tubular body that is to be punched. Although this method allows the same split-mandrel to be used for a range of tube diameters, it suffers from the obvious disadvantage of requiring the use of large amounts of material to make the mandrel and difficulties in supporting the mandrel for long elongate hollow bodies. Furthermore, this method is somewhat sensitive to the straightness of the interior of the hollow body.
Aizaki et al., U.S. Pat. No. 5,140,881, issued Aug. 25, 1992, describes an apparatus which uses an interior punch in combination with an exterior die to punch a hole in the sidewall of a cylinder from the inside out. The punch mechanism is contained within a sleeve tube that fits inside the cylinder that is to be punched. The punch mechanism consists of a radially-situated, floating punch, a bar-like cam supporting the floating punch, and a cylindrical member slidably inserted into the sleeve tube. The cylindrical member is attached to the bar-like cam at one end and at the other to a device which can axially reciprocate the cylindrical-member within the sleeve tube so as to cause the bar-like cam to force the floating punch radially outward through the cylinder wall and into the exterior die and then radially inward withdrawing the floating punch from the cylinder wall. Although this apparatus could conceivably be adapted to shapes other than cylinders, it has the disadvantage that the sleeve must be sized to closely approximate the interior size of the hollow body to be punched. Thus, uniformities in interior straightness and size of the hollow body are important constraints on the operation of this method. This method also has the disadvantage that, for long elongate hollow bodies, the punch mechanism is cumbersome and relatively expensive.
SUMMARY OF THE INVENTION
The present invention comprises a novel apparatus, system, and method for satisfying the need for economically and reliably punching holes along the length of elongate hollow bodies of any shape and length while overcoming the disadvantages inherent in the prior art devices described above.
The apparatus of the present invention comprises an expandable die that is insertable into the elongate hollow body. In operation, the expandable die cooperates with the punch or punches of an external conventional punch press. The expandable die is connected to the free end of a longitudinal member. The longitudinal member is hereinafter referred to as the positioning bar because it is used to longitudinally position the expandable die in relation to the punch or punches of the punch press. The distal end of the positioning bar is fixed in relation to the punch press. Preferably, the positioning bar is attached to a conventional support table and the attachment is made in a manner that allows for adjusting and then locking the longitudinal position of the expandable die with respect to the punch or punches of the punch press.
The expandable die is inserted into the elongate hollow body by sliding the hollow body through the gap between the expandable die and the punches of the punch press to the location where a hole or set of holes is to be punched. The expandable die has a die member which has one or more die cavities for receiving the punch or punches of the punch press. The cross-sectional shapes and sizes of the die cavities and the punches are made to produce the desired shape and size of hole or holes that are to be punched. Such cross-sectional shapes may be circular or non-circular so that a circular or a non-circular hole is punched, respectively. The expandable die also has a base member. The die and base members are designed so as to cooperate in supporting the elongate hollow body during the punching operation in a manner which prevents the elongate hollow body from becoming dented or otherwise damaged. Preferably, the outside surfaces of the
Dexter Clark F.
Friedman Barry I.
Lizzi Thomas
Metz Lewis LLC
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