Metal working – Method of mechanical manufacture – Obtaining plural product pieces from unitary workpiece
Reexamination Certificate
2001-10-11
2004-03-23
Bryant, David P. (Department: 3726)
Metal working
Method of mechanical manufacture
Obtaining plural product pieces from unitary workpiece
C029S564600, C029S564700, C029S564800, C029S03300H, C072S181000
Reexamination Certificate
active
06708384
ABSTRACT:
FIELD OF THE INVENTION
The present invention concerns muntin bars used for separating window panes of large size into smaller size panes to enhance the appearance of a window.
BACKGROUND ART
Windows constructed from multiple glass panes utilized “muntins” or “muntin bars” to secure the edges of the individual glass panes within the window sash. In many windows, muntins formed distinctive grid patterns that are associated with architectural styles of buildings containing the windows.
Modern windows formed by insulating glass units utilize single glass lites separated by an insulating dead air space. Where a particular architectural “look” is desired, a grid of muntin bars is fixed in the dead air space between the glass lites to simulate a multi-pane window. Typical muntin bars for insulating glass units are formed from decoratively coated interfitted metal tubes. The grids are anchored to the insulating glass unit periphery.
Constructing muntin bar grids for insulating glass units has been a labor intensive process. As a consequence, manufacturing such units, and thus windows formed by the units, has been costly and inefficient. Some efforts to mechanize the manufacture of muntin grids have been made. Commonly owned U.S. Pat. No. 6,173,484 entitled “System for Fabricating Muntin Bars from Sheet Material” which issued Jan. 16, 2001 to McGlinchy et al. is an example of a system for automated fabrication of muntin bars. The subject matter of this patent is incorporated herein by reference. Commonly owned pending U.S. patent application Ser. No. 09/525,349 entitled “System for Fabricating Contour Muntin Bars from Sheet Material” is a second patent application to McGlinchy et al concerning automated fabrication of so-called contour muntin bars and the subject matter of this application is incorporated herein by reference.
The muntin bar stock is produced by roll forming decoratively coated sheet material such as aluminum or steel, in a known manner. Various sizes of the sheet material are used to form different size muntin bar stock. The roll forming machine has a series of rolls configured to form sheet material into elongated tubular muntin bar stock. A window manufacturer purchases the muntin bar stock size(s) needed to produce insulating glass units. Apparatus disclosed in the aforementioned patent application also cuts the stock into lengths that are notched in appropriate locations for assembly into grids for incorporation into the insulating glass units.
The residential window and door industry has witnessed an increased demand for internal decorative muntin bars contained in insulated glass units (IGUs) of their windows. This market demand for muntin bars has increased due to popular “colonial look” trends in the market. Also contributing to the demand are new construction and residential building codes requiring a common facade in local neighborhoods. With people also desiring differentiation and designer choices in their windows, a demand for so-called “two tone” muntin bars is on the rise. The two tone muntin bar assembly presents one appearance from the outside and a second appearance from inside the window.
Two-tone muntin bars are offered today in many color combinations for both rectangular and contour style muntin bars. A two-tone muntin bar demands a premium price in the market place. One reason for the increased price of two tone muntin bars is the fact that automated manufacturing of two tone muntin bars using controlled notching, roll forming and severing has not occurred.
The most common method practiced at the present time for manufacturing two tone muntin grids starts with a long roll formed bar that is often shipped to a secondary supplier that paints or laminates the bar with a solid color tone or wood pattern on one side and a second color or wood pattern on the opposite side. Use of multiple steps performed by multiple suppliers results in significant additional cost to the product. More elaborate bars have simulated wood grains that are used to match up with the wood trim in or surrounding the window sash. All of the current methods require cutting specified length segments from a two tone bar. This bar is then mitered and/or punched to complete fabrication of the muntin bar. The current methods require post painting and/or lamination of the formed muntin bar which is time consuming, costly and constrained throughput in a production environment. The current process also leads to a build up of material inventory to give the suppliers adequate lead time for performing these post roll forming procedures.
SUMMARY OF THE INVENTION
The present invention concerns an automated method and apparatus for producing notched muntin bars from a supply of sheet material having first and second finishes. In accordance with one process muntin bars having first and second finishes are provided that have one appearance when viewed from outside the window and a second appearance when viewed from inside the window.
In an exemplary embodiment of the invention a supply of thin sheet material that has been treated to define first and second finishes on one side of the sheet material is provided. Sections of the material having the first finish and sections of the material having the second finish are removed from the sheet material. The sheet material is then formed into an elongated tubular muntin bar stock. The muntin bar stock has a first side having the first finish and a second side having the second finish. The muntin bar stock has notches in the first side that correspond to the removed sections of material having the first finish. The formed muntin bar stock has notches in its second side that correspond to the removed sections of material having the second finish. The muntin bar stock is severed at predetermined locations to form individual notched muntin bars. The notches in the individual muntin bars are located along the length of the muntin bars to allow the individual muntin bars to be combined to form a muntin bar grid having a first side with the first finish and a second side with the second finish.
One aspect of the invention is used to make a first set of muntin bars that will be assembled in a first orientation. Each of the muntin bars in the first set of muntin bars includes notches only in the side having the first finish. Each muntin bar in a second set of muntin bars that will be assembled in a second orientation includes notches only in the side having the second finish. By notching the muntin bars that will be assembled in the first orientation only on one side and notching the muntin bars that will be assembled in the second orientation on the opposite side, a muntin bar grid having first and second finishes on opposing sides is easily assembled.
An apparatus for making notched muntin bars having sides with first and second finishes includes a ribbon stock support or uncoiler, a notching device, a roll forming machine and a severing device. The uncoiler supplies the ribbon stock having one surface with first and second finishes. The notching device receives the ribbon stock from the supply of ribbon stock. The notching device has a punch that is movable between a first position where the punch is engageable with ribbon stock having the first finish and a second position where the punch is engageable with ribbon stock having the second finish. The roll forming machine receives ribbon stock from the notching device to form hollow muntin bar stock that has a first side with the first finish and a second side with the second finish. The formed muntin bar stock has notches in one side that correspond to removed sections of material having the first finish and notches in the second side that correspond to removed sections of material having the second finish. The severing device severs the formed muntin bar stock to form individual notched muntin bars having sides with first and second finishes.
In the exemplary embodiment, the notching device includes a pneumatic cylinder that moves the punch between the first and second positions. A control is coupled to
Bryant David P.
Glass Equipment Development, Inc.
Watts Hoffmann Co. L.P.A.
LandOfFree
Notched muntin bars having two finishes does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Notched muntin bars having two finishes, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Notched muntin bars having two finishes will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3259409