Abstract:
An improved set of calipers or dividers having a pair of measurement jaws for measuring the distance between points, a display, and a calculation module which performs calculations or retrieves values for any one or more of the following functions: scaling, nominal values, basic geometry, and complex geometry. The scaling function is performed in one of two ways: numerical input or a calculated scaling factor. The nominal values function displays the nominal value which corresponds to the measured value of any preprogrammed table of values. Common tables would include tables of drill sizes, wire gauge, sheet metal gauge, screw size, font size, paper weight, hole size, etc. The basic geometry function calculates geometric values based on one or more measured inputs. For example, the user can measure the opposite and adjacent legs of a triangle and the caliper will calculate and display the angle. With the complex geometry function, the user can input measured inputs and obtain exact or approximate values for more complicated formulas such as area, moments of inertia, approximate area under a curve. For embodiments where the user is prompted for information on a pictorial display, a larger display is used to allow for the pictorial image.

Description:
CROSS-REFERENCE TO OTHER APPLICATIONS 
     The present invention claims the benefit of U.S. Provisional Patent Application No. 60/057,051, filed Aug. 27, 1997, which is hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND-FIELD OF INVENTION 
     The present invention relates to electronic calipers. More particularly, the present invention relates to electronic calipers having multiple function modes, each mode allowing the user to perform a basic mathematical or geometric calculation, such as scaling the measurement by a chosen value, providing a nominal value corresponding to the physical measurement, and/or utilizing physical measurements in geometric formulas to determine other calculable values. 
     BACKGROUND OF THE INVENTION 
     Most calipers currently in use are designed for inspection of existing parts and materials. This is optimal for occupations such as inspector, machinist or fabricator, where the user wants to verify a particular dimension, wants to know a dimension for design of a corresponding part, etc. However, engineers, designers, architects, and pattern makers frequently have different needs. When creating a new part, important information may be obtained for alternate sources, including drawings, catalogues, facsimiles, and photographs. Since, many of these sources are not printed in a known scale and/or rarely have all the necessary dimensions, the user must make repetitive manual calculations using a calculator, a machinists handbook, protractor, an architects scale and a caliper to obtain the desired or necessary values for the new part. 
     Some prior art device have attempted to overcome some of these limitations. For example, U.S. Pat. No. 4,435,904 to Logan et al. describes an automated measuring scale which aids a user in scaling values by allowing a user to input a scale factor and a scaled number. When the system is then activated, the device automatically moves the index member an amount which is scaled by the scale factor. 
     U.S. Pat. No. 5,067,249 to Terrigno calculates the number of miles along a path by scaling the distance a rolling disk travels on a map by the corresponding map scale. 
     These prior art devices are limited to a basic scaling of a particular measured distance by an entered scale factor. Therefore, there is a clear need in the industry for a device which is more versatile and allows a user to calculate the scale factor, calculate other values based on measured parameters, display alternate nominal values such as wire or sheet gauge, paper weight, etc. which correspond to a measured value, and measure values which are automatically input into geometric formulas and used to calculate resulting values. 
     SUMMARY OF THE INVENTION 
     Accordingly, the object of the present invention is to provide an electronic caliper or divider which can convert physical measurements by chosen parameter(s) to calculate and/or display chosen or nominal values while maintaining the ease-of-use, simplicity and elegance of current digital calipers. The present invention is particularly designed to calculate and display scaled values from either an input or a calculated scale factor; display a nominal value corresponding to a measured value such as, wire gauge, sheet metal gauge, paper weight, etc.; a value calculated from a simple geometric function, such as area, radius, angle, perimeter, volume, etc.; or an exact or approximate value calculated from a more complex geometric function, such as moment of inertia, area under a curve, areas of more complex shapes, etc. 
     In keeping with the forgoing discussion, the present invention takes the form of a set of calipers having a pair of measurement jaws for measuring the distance between points, a display and a calculation module which performs calculations or retrieves values for any one or more of the following functions: scaling, nominal values, basic geometry, and complex geometry. 
     The scaling function is performed in one of two ways: numerical input or a calculated scaling factor. The numerical input is for cases where the drawings, model, or item to be measured is of a known scale. The user inputs that scale. Further measurements are then multiplied by this scale factor and displayed. The calculated scaling factor is for cases in which the user is uncertain of the scale, but has a reference dimension. In this case, the user measures the reference dimension, then inputs the value corresponding to the actual dimension of the object. The calculation module then calculates the scale factor and scales further measurements by the scale factor. 
     The nominal values function displays the nominal value which corresponds to the measured value of any preprogrammed group. Common groups would include tables of drill sizes, wire gauge, sheet metal gauge, screw size, font size, paper weight, hole size, etc. Optimally, this function also displays nominal values for manually input values or scaled values. 
     The basic geometry function calculates geometric values based on one or more measured inputs. For example, the user can measure the opposite and adjacent legs of a triangle and the caliper will calculate and display the angle. Geometry functions can be programmed for radius, angle, area, perimeter, volume, etc. These measurements could be measured in many units, inch, metric, and scaled. 
     With the complex geometry function, the user can input measured inputs and obtain exact or approximate value for more complicated values such as area, moments of inertia, area under a curve, etc. The caliper may be designed to display in pictorial form different items, like an I-beam. The user can then measure different values as the caliper prompts the user for specific measurements. When all the measured inputs have been entered, the caliper will display the results. Again, many units can be used, inch, metric, or scaled. For embodiments where the user is prompted for information on a pictorial display, a larger display is used to allow for the pictorial image. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     FIG. 1 is a front view of the electronic calipers of the present invention. 
     FIG. 2 is a front close-up view of the jaws and body of the electronic calipers displaying the scaling function. 
     FIG. 3 is a front close-up view of the jaws and body of the electronic calipers displaying the nominal value and simple geometry functions. 
     FIG. 4 is a front dose-up view of the jaws and body of an alternate embodiment of calipers. 
     FIG. 5 is a front view of a dividers version of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIGS. 1,  2 , and  3  show the first embodiment of the electronic calipers  10  of the present invention. FIG. 1 is an overall side view of the calipers  10 , and FIGS. 2 and 3 show different displays corresponding to some of the possible functions of the calipers  10 . The electronic calipers  10  have a first jaw  12  and a second jaw  14 . As the second jaw  14  moves along the guide rail  16 , the calipers  10  measure the distance between the two jaws  12 ,  14 . Although other jaw  12 ,  14  configurations may also be used, in the embodiment shown, the first jaw  12  has a first end  18  and a second end  20 , and the second jaw  14  also has a first end  22  and a second end  24 . The distance the calipers  10  measures is the space between the inner faces  26 ,  30  of the first ends  18 ,  22  of the first and second jaws  12 ,  14  or the distance between the outer faces  28 ,  32  of the second ends  20 ,  24  of the first and second jaws  12 ,  14 . An optional thumb wheel  54  assist the user in moving the jaws  12 ,  14  in relation to one another. 
     Attached to the second jaw  14  of the calipers  10  is a calculation/display module  36  containing a digital display  38 , four input buttons  40 ,  42 ,  44 ,  46 , and a calculation module  52 . The calipers also optionally include a hold button  50  to hold the digital value in the module  52  and a thumbscrew  48  to physically hold the jaws  12 ,  14  in a particular configuration. In standard mode, the digital display  38  indicates the value corresponding to the distance between the jaws  12 ,  14 . The four input buttons include: a power button  40 , an increment button  44 , a decrement button  46 , and a enter button  42 . These buttons  40 ,  42 ,  44 ,  46  allow the user to access and use the scaling, nominal value, basic geometric and complex geometric functions of the present invention. 
     The preferred method for entry of numerical values is accomplished in two or three parts: the integer portion, the fractional portion and the units of the number, if necessary. The integer and fractional portions are input by scrolling up or down to the value and pressing the enter button  42  when a user reaches a point where numerical entry of a value is desired. Initially, the display  38  reads a flashing “0000.” The user then presses the increment button  44  or the decrement button  46  to scroll to the desired value. Pressing the increment button  44  or the decrement button  46  once scrolls one unit. Continue holding either button  44 ,  46  down and the value scrolls slowly at first and jumps to faster speeds. Once the integer portion is reached, the enter button  42  is pressed. For example, if 10.50 is the required scale, the display  38  is scrolled to  10  and the enter button  42  is pressed. At this point, the display  38  reads a flashing “10.00.” The user then scrolls the fractional portion up or down to 50. This scrolling works exactly as it did for the integer portion. When “10.50” is displayed, the enter button  42  is pressed, saving the value of 10.50 to memory. If necessary for a particular function, the units are then selected. For functions requiring units, after the enter button  42  is pressed, the units flag  60  flashes, thereby prompting the user to enter the units. The user toggles between units, i.e. English and metric by pressing the increment button  44  or the decrement button  46  and then pressing the enter button  42 . If a mistake is made before the last enter  42  is pressed, the power button  40  can be pressed. This action allows the user to retain the last saved value to perform measurements or to restart the entry process. 
     Alternate designs could enter the data with more or less than the four buttons  40 ,  42 ,  44 ,  46  given in the embodiment shown. Also, numerically entered data could be entered may different ways, including, but not limited to, a numeric keypad, knobs, thumb screws, etc. Also, different strategies of entering the data other than integer and fraction could be employed, i.e. entering each digit and the location of the decimal point, keypad, scrolling the entire number, opening the jaws to display an exact number, etc. 
     In order to use the calipers  10 , they first must be turned on, which is done by pressing the power button  40 . Once the calipers  10  are on, the user selects a function by scrolling through the options with the increment button  44  and/or decrement button  46 . For example, after the power button  40  is depressed, the last used mode will appear. The modes include the standard English measurement, the standard metric measurement, set scale, calculate scale, gauge, nominal value, radius, angle, area, etc. Once the desired mode is displayed, the user presses the enter button  42  to select the mode and proceeds with the necessary measurements as described below. 
     An alternate version of the calipers  10  have all of the modes categorized allowing the user to select a category, then select the specific function within the category. The categories currently envisioned include the standard measurement, scaling, nominal values, basic geometry, and complex geometry. For ease of explanation. The remainder of the description is broken in these groups for explanation and illustrative examples. 
     To use the standard measurement, the user selects the desired standard measurement, either English indicated by “in”  62  on the display  38  or metric indicated by a “mm”  64  on the display  38 . Then, the user makes any desired measurements similar to the operation of a standard caliper. The jaws  12 ,  14  are used to precisely measure whatever is desired: the side of a part, an internal diameter, an external diameter, etc. 
     To use the scaling function, the user selects the desired scale mode, either the set scale function indicated by an “ss”  66  on the display  38  or the calculate scale function indicated by a “cs”  68  on the display  38 . The set scale function is used when the user knows the exact scale required. For example, if the user wanted to scale all measured values by a factor of 1.5, he or she would select the set scale function, then enter the scale of 1.500 and select the proper units. Measurements taken after setting the scale would be multiplied by the scale factor and displayed. If the user measured a distance where the jaws  12 ,  14  of the calipers  10  were 2.000 inches apart, the display  38  would show 3.000 inches. This function would be especially useful for pattern makers, mold makers, architects and users that have drawings or patterns of a known scale. 
     The calculate scale mode is used when a drawing or photograph has an unknown or uncertain scale, but has at least one know dimension. First, the user selects the calculate scale mode. At this point, the calipers  10  display the last saved scaling factor. To begin entry of a new scale, the jaws  12 ,  14  are opened to a reference dimension from the item being measured and the enter button  42  is pressed to enter the reference dimension. On pressing the enter button  42 , the calipers  10  save the actual distance the jaws  12 ,  14  are opened and flashes “0000” on the display  38 . The user then enters the actual value of the dimension, either by setting the calipers  10  to the actual dimension and pressing the enter button  42 , or by numerically entering the value as described above. No units are needed because the calculate scale mode is unitless and thus is automatically in the units of the entered dimension. The calipers  10  calculate the scale by dividing the actual entered value by the reference dimension entered. This scale is then multiplied by all other caliper jaw  12 ,  14  displacements to display values scaled by the scaling factor, thereby displaying values corresponding to actual values. This function is useful when working from incomplete date, i.e. photographs, brochures, facsimiles, sketches and other documents. This would be particularly valuable for reverse engineering, layouts, faxed drawings and drawings printed out of scale. As before, the power button  40  can be depressed at any time before the last entry and the last calculated scale factor is saved and the user can start again. 
     The nominal values function is used to determine the nearest nominal value which corresponds to a measured material. To use this function, the user selects the nominal value function which is indicated by a “ga”  70  on the display and the type of nominal value desired: wire gauge, sheet metal gauge, paper thickness, drill size, hole size, screw size, and font size. Then, when the jaws  12 ,  14  are used to measure a material, the nearest gauge or nominal value is displayed. Similar features could be added for other type of values where a measurable value corresponds to a non-inch/non-metric number. These functions are preprogrammed look-up routines which display the nearest value in a pre-entered table of values. These functions would save the user from hauling around different scales and handbooks. 
     The other two function categories contain the geometric calculations. The first category contains the basic geometric equations for areas, circumference, volumes, perimeters, radius, etc. When one of these modes is selected, the calipers  10  prompt the user to enter the necessary measurement(s), then calculates and displays the desired resulting value. For example, if the area of a rectangle is to be determined, the user selects the area mode. The calipers  10  then prompt the user to measure a first length side of the rectangle, then measure a second length side of the rectangle. Once these two measurements are made, the calipers multiply the values together and displays the result, which is the area of the rectangle. 
     If the user wanted to determine the radius of curvature, the radius function is used. The calipers prompt the user to enter the appropriate units, then measure across the arc length and the arc height. The calculated radius of curvature is displayed in the selected units. 
     The angle function allows the user to calculate in degrees. When the user wishes to calculate a new angle, he or she opens the jaws  12 ,  14  to the adjacent length (x) and press the enter button  42 , then opens the jaws  12 ,  14  to the opposite length (y) and press the enter button  42 . The display  38  then shows the angle in degrees. 
     The complex geometry functions are a group of more complex geometrical calculations, i.e. area of more complex shapes, moments of inertia, areas under a curves, etc. For some of these functions, the calipers  10  make estimates to allow the user to obtain an approximate result for the desired value. These functions along with those listed above, would be included in a pair of calipers with an enlarged display, i.e. 1.5 inches by 2.0 inches. The data required and calculated could be presented in a pictorial fashion where the user could scroll through the required and desired values. Input for these function would be performed similar to the method for the basic geometric functions. 
     FIG. 4 is a front close-up view of the jaws  12 ,  14 , body, and module  80  of an alternate calipers  78  embodiment. The input buttons  82 ,  84 ,  86 ,  88  are in a single line to allow easy access, and a slide switch  90  is used to select a mode, English, or metric units. 
     FIG. 5 is a front view of a dividers  100  version of the present invention. In this case, the module  102  is mounted on the upper portion of the pivotally connected dividers. The module  102  calculates the distance between the jaws or tips  104 ,  106  of the dividers  100  and uses this as the measured input. This device  100  can use the same set of functions as the embodiments above, including: standard measurement, scaling function, nominal value function, basic geometry function, and complex geometry function. The current display  108  is similar to existing calipers with the addition of bullets  110  that indicate which function is in use. Other methods could be used such as larger alpha-numeric display, LEDs, etc. 
     Alternate embodiments could also have interchangeable jaws for different types of measurement, i.e. internal holes. Also, it could have compass jaws allowing for drawing circles. 
     Many features have been listed with particular configurations, options, and embodiments. Any one or more of the features described may be added to or combined with any of the other embodiments or other standard devices to create alternate combinations and embodiments. The features of one of the functions may also be used with other functions. For example, a scaled measurement could be converted to a nominal value such as a wire gauge. 
     Although the examples given include many specificities, they are intended as illustrative of only one possible embodiment of the invention. Other embodiments and modifications will, no doubt, occur to those skilled in the art. Thus, the examples given should only be interpreted as illustrations of some of the preferred embodiments of the invention, and the full scope of the invention should be determined by the appended claims and their legal equivalents.