Abstract:
A window measuring device measures the distance between a target feature and a datum feature on a window. In another aspect of the present invention, a window measuring device is flexibly conformable to a curved window. Yet another aspect of the present invention provides a window measuring device having a pair of legs with incremental marking and a target feature alignment portion.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates generally to a window measuring device and more specifically to a multi-directional measuring device for a window. 
     Windows for automotive vehicles usually having regions of colored or opaque ceramic frit which is silkscreened onto flat glass panels which are subsequently bent into a final curved shape. Such frit regions often include manufacturer logos, part numbers, heating grids, antennas and a blackout band adjacent to an edge of the window. It has been desirable to measure the distance of such logos and features from the edge of the window in order to check the accuracy of the silkscreening operation. Conventionally, such measuring has been conducted by use of a single or a pair of separate rulers. This has been proven to be inaccurate, unwieldy and time consuming. 
     Various traditional carpentry and drafting measurement tools, entirely independent from the glass industry, have also been employed for this window measuring purpose. For example, reference should be made to the following U.S. Pat. No. 5,090,129 entitled “Carpenter Square” which issued to Cunningham on Feb. 25, 1992; U.S. Pat. No. 494,169 entitled “Combination Gage” which issued to Schaum on Mar. 28, 1893; and U.S. Pat. No. 310,420 entitled “Combination Gage” which issued to Hellings on Jan. 6, 1885. Furthermore, U.S. Pat. No. 2,964,848 entitled “Portable Glass Cutting Machine” which issued to Gonsalves on Dec. 20, 1960 discloses a glass cutting machine having multiple measuring members. However, these devices, too, have been unsatisfactory for the intended purpose. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention, the preferred embodiment of a window measuring device measures the distance between a target feature and a datum feature on a window. In another aspect of the present invention, a window measuring device is flexibly conformable to a curved window. Yet another aspect of the present invention provides a window measuring device having a pair of legs with incremental markings and a target feature alignment portion. In still another aspect of the present invention, a window measuring device is employed to measure the distance between an opaque target feature and at least two edges of a window. 
     The window measuring device of the present invention is advantageous over prior arrangements by providing a much more accurate measurement. The integrated and one-piece multi-directional construction of the present invention further allows for measurements to be taken in two directions in a quick, generally simultaneous manner. The flexible nature of the present invention is ideally suited in measuring “frit to edge of window” distances for formed automotive glass. Furthermore, the present invention is very economical to produce, compact and is durable since it has no moving parts. Additional advantages and features of the present invention will become apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a rear elevational view showing a typical rear automotive window with which the present invention is utilized; 
     FIG. 2 is an enlarged rear elevational view, taken within circle  2  of FIG. 1, showing the preferred embodiment of the window measuring device of the present invention in use in the window of FIG. 1; 
     FIG. 3 is a cross sectional view, taken along line  3 — 3  of FIG. 2, showing the preferred embodiment of the window measuring device in use on the window of FIG. 1; 
     FIG. 4 is a true elevational view showing the preferred embodiment window measuring device; 
     FIG. 5 is a true elevational view showing a first alternate embodiment of the window measuring device; and 
     FIG. 6 is a perspective view showing a second alternate embodiment of the window measuring device. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A curved rear window or backlite  11  is shown in FIGS.  1 — 3 . Backlite  11  is formed from a sheet of glass. A ceramic frit blackout band  13  is silkscreened onto an interior surface  15  of backlite  11 . A ceramic frit manufacturer&#39;s logo  17  or part number is also silkscreened onto backlite  11 . Furthermore, a ceramic frit defroster grid  19  is silkscreened onto interior surface  15  of backlite  11 . The ceramic frit is generally opaque and often colored black, brown or silver. The frit is denoted herein as an example of a target feature. The ceramic frit is composed of materials such as those disclosed in U.S. Pat. No. 5,244,484 entitled “Process for Producing a Curved Glass Plate Partially Coated with a Ceramic” which issued to Chiba et al. on Sep. 14, 1993 and is incorporated by reference herein. 
     The preferred embodiment of a window measuring device  31  includes four integrally joined and elongated legs  33 ,  35 ,  37  and  39 . Referring to FIGS. 2-4, each of the legs have incremental markings adjacent to an edge. The incremental markings are illustrated herein as millimeters, but can be in any predetermined units of measurement. Leg  37  is perpendicularly joined to a middle section of relatively shorter leg  33  while leg  39  is perpendicularly joined to a middle section of relatively shorter leg  35 . Legs  33  and  35  are perpendicularly joined together to define a crotch  41 . The incremental markings of the legs  37  and  39  preferably include an axis that intersects the crotch  41  of the legs  33  and  35 . The leg angles of a window measuring device  31 ′ may vary as is alternately shown in FIG. 5 in order to optimally coincide to the orientation of the datum or reference points desired. 
     Window measuring device  31  is preferably stamped from a single piece of sheet steel but may alternately be cut from plastic which has minimal expansion properties due to heat or moisture. The thickness t of window measuring device  31  is much less than its leg width w. Thus, window measuring device  31  can flexibly conform to a highly curved window as is typical for automotive vehicles. 
     Another alternate embodiment of the present invention can be observed in FIG.  6 . In this embodiment, a window measuring device  131  has the outlines of four legs  133 ,  135 ,  137  and  139  printed, silkscreened, etched or otherwise permanently affixed to a thin sheet of transparent plastic  141 . Plastic sheet  141  can be made of flexible acrylic, mylar or the like. This advantageously protects the window from any inadvertent damage or scratching during measuring. It is also lightweight and easy to see through the legs. 
     The preferred embodiment window  11  and measuring device  31  are made and used together as follows. The edges of a window are cut and then ground from a large flat sheet of glass. The ceramic frit, including target features, is then silkscreened onto the window and heated to dry. Next, the window is heated in a furnace and bent to a desired curved shape. The formed window is subsequently cooled on a quench ring. Examples of such steps and machinery can be found in the following U.S. patents, which are assigned to Asahi Glass Company Ltd. and are incorporated by reference herein: U.S. Pat. No. 5,393,316 entitled “Glass Plate Bend-Shaping Apparatus and Method of Bend-Shaping a Glass Plate” which issued to Sugiyama et al. on Feb. 28, 1995; U.S. Pat. No. 5,332,412 entitled “Process for Producing a Glass Sheet with a Ceramic Color Composition and a Conductive Strip” which issued to Manabe et al. on Jul. 26, 1994; U.S. Pat. No. 5,240,816 entitled “Method of Producing a Screen for Printing a Heating Line Pattern and a Method of Forming a Heating Line Pattern on a Glass Plate” which issued to Noguchi et al. on Aug. 31, 1993; and U.S. Pat. No. 5,178,659 entitled “Method of an Apparatus for Bend-Shaping a Glass Plate and Bending Mold Used for Them” which issued to Watanabe et al. on Jan. 12, 1993. 
     After the previous steps, the window measuring device is employed to check the locational accuracy of the frit, including target features, to a datum or reference, such as the window&#39;s edges. More specifically, logo  17  is aligned in crotch  41  of measuring device  31  such that the inside facing edges of legs  33  and  35  contact against the outside edges of logo  17 . Concurrently, legs  37  and  39  overhang edges  171  and  173  of window  11 , respectively. Hence, two visually observed distance measurements can be read and compared to desired values. It should be appreciated that such a measurement can be conducted on either the inside or outside window surface. The incremental markings on measuring device  31  can also be continuous between the crotch and window edge portion of the legs. 
     While various embodiments of the window measuring device and window have been disclosed, it should be appreciated that other modifications may be employed without departing from the present invention. For example, the present invention measuring device can be used with windshields, automotive side windows, appliance shelves, building windows, or other formed or flat windows. Furthermore, a target feature alignment portion on the measuring device  31  can be differently configured and may even fully surround the target feature. The target feature can also constitute a formed glass shape or adhesively applied part rather than an opaque frit marking. In another construction, the device may have a “+” configuration wherein the legs  33 / 35  and  35 / 37  are aligned with each other. Various materials for constructing the measuring device  31  have been disclosed in an exemplary fashion, however, other materials may of course be employed. It is intended by the following claims to cover these and any other departures from the disclosed embodiments which fall within the true spirit of this invention.