Abstract:
A pipe reference and calculating device pipe reference and calculating device includes a housing that can be held in a hand of a user. A processor is contained within the housing. A keypad is on the housing and is electrically connected to the processor. The keypad operates a plurality of switches, each switch controlling a circuit to produce an input signal to the processor for a desired function. A display screen and a memory device are disposed in the housing and are electrically connected to the processor. Software is stored in the memory device. The software causes the processor access data from a database of pipe reference information and data, and formulas, perform pipefitting calculations with data accessed from the database, perform calculations on data input from the keypad, and perform pipefitting and geometric calculations using graphical images with labeled variables.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/536,715, filed Jan. 16, 2004. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates generally to electronic calculating devices. In particular, the invention relates to a handheld calculating device having a complete pipe reference source for solving a variety of piping problems. 
   2. Description of Related Art 
   Pipe fitters, pipe fabricators, and plumbers all have jobs that require pipe fabrication and/or installation. Pipe fitting tasks typically require a person to use a calculator, and to refer to reference books for data and formulas for solving a variety of piping problems that occur during the fabrication and/or installation pipes. One problem is that most fitters, fabricators, welders, plumbers and others working with pipes do not learn enough mathematics to realize their full potential, so that many workers do not have the ability to remember the formulas required, or require considerable time to figure out how to use a formula properly, even with the assistance of an electronic calculator. This results in the craftsman having to use far less accurate calculations and more time consuming methods to fabricate or fit the piping being worked on. 
   Every project superintendent that has any sizable amount of piping on their job knows that among the journeyman there are many different skill levels. A person in supervision is charged with the duty of assigning the appropriate tasks to the appropriate journeyman. More often than not there is the problem of not enough craftsmen with a high level of skill to go around. The calculator of the present invention is the equalizer a craftsman needs to bring him or her to a higher level of performance in order to enjoy a previously unattainable level of success in their career. This translates into a higher earning potential and more efficient job performance. 
   Various calculating devices have been programmed to provide various functions for assisting work related activities. However, the relevant art does not provide a calculator capable of performing the necessary calculations required for pipe fabrication and/or installation. Nor does the relevant art provide such a calculator having a graphical interface to assist a user in performing the necessary calculations required for pipefitting applications. 
   U.S. Pat. No. 5,111,426, issued May 5, 1992 to Bergstresser, Sr. et al., shows a handheld calculator that allows welders to manipulate welding and cutting data for a job at hand. The calculator includes a complete welding reference source providing on-the-spot answers to problems and can calculate data necessary for the completion of a welding task. The calculator includes a saving and retrieving function that allows a user to quickly retrieve information from a subset or compare a calculation to a subset. Similarly, U.S. Pat. No. 6,167,412, issued Dec. 26, 2000 to Simons, discloses a handheld medical calculator and medical reference device having an input keypad and an output screen connected to a processor with memory to perform specific clinical functions. Some of the clinical functions require accessing various medical reference tables to perform complex medical calculations. 
   U.S. Pat. No. 5,265,029, issued Nov. 23, 1993 to Ramsay, discloses a chemical calculator providing rapid and convenient ways to retrieve information and perform calculations of chemical elements and chemical formulas obtained by direct entry from a periodic table keypad. These calculations allow chemists to compute chemical transformations, reaction yields, limiting reactants, and empirical formulas. U.S. Pat. No. 4,744,044, issued May 10, 1988 to Stover et al., describes a handheld calculator for specialized dimensional calculations. The calculator may be used to calculate the dimensions and unit price of lumber. 
   U.S. Pat. No. 3,979,057, issued Sep. 7, 1976 to Katz et al., discloses an electronic calculator having a limited stored program capability and which is adapted to perform a plurality of problems particularly useful to aircraft pilots. The programs stored in the calculator cause sequential operation, including the demand for manual entry of necessary data, to calculate a desire result. U.S. patent Publication No. 2003/0126166, published Jul. 3, 2003, discloses a handheld computing device providing instructions for a user to graphically display vectors on a display screen. The device performs vector operations for one or more vectors using an input device while concurrently graphically viewing the vector and the vector changes on the display screen. 
   Several calculating devices include soft or programmable keys that provide a user with various functions that assist in performing desired calculations. U.S. Pat. No. 4,823,311, issued Apr. 18, 1989 to Hunter et al., shows a calculator keypad having keys with labels created by a display and subject to interactive change as the user desires. Specialized function keys with different functional labels provide a user with various desired functions. U.S. Pat. No. 4,107,782, issued to Cochran, discloses a user programmable calculator having special keys in addition to the numerical and function keys normally incorporated into a calculator in order to facilitate responding to data functional information requests by the calculator. 
   U.S. Pat. No. 4,680,455, issued Jul. 14, 1987 to Kuo, describes a method of manipulating a calculator using special function keys and instructions from a selected instruction card. The instruction cards provide formulas and equations to achieve various desired calculations. U.S. Pat. No. 4,035,627, issued Jul. 12, 1977 to Dickinson et al., describes a handheld calculator with keys for performing arithmetic, trigonometric, and logarithmic functions. U.S. Pat. No. 4,852,057, issued Jul. 25, 1989 to Patton, discloses a calculating device having stored menus with labels of operations that are performed on mathematical expressions. 
   U.S. Pat. No. 4,695,983, issued Sep. 22, 1987 to Oda et al., shows a calculator capable of executing formula calculations with different operational sequences. The calculator comprises means for selecting and designating either the sequential operation mode that sequentially executes formula calculations according to individual key operations, or a formula memory operation mode that executes operations after entry of the sequential operation mode. U.S. Pat. No. 4,078,251, issued Mar. 7, 1978 to Hamilton, describes an electronic calculator having an instruction word memory for storing instruction words that is addressable by the address register, and instruction word decoder logic for decoding the instruction words and for controlling the arithmetic unit in response thereto. 
   None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed. Thus, a pipe reference and calculating device solving the aforementioned problems is desired. 
   SUMMARY OF THE INVENTION 
   The present invention is a pipe reference and calculating device. The device includes a housing dimensioned and configured for being held in a hand of a user. A processor is contained within the housing. A keypad is on the housing and is electrically connected to the processor. The keypad operates a plurality of switches, each switch controlling a circuit to produce an input signal to the processor for a desired function. A display screen is disposed in the housing and is electrically connected to the processor. A memory device is disposed in the housing and is electrically connected to the processor. Software is stored in the memory device. The software causes the processor access data from a database of pipe reference information and data, and formulas, perform pipefitting calculations with data accessed from the database, perform calculations on data input from the keypad, and perform pipefitting and geometric calculations using graphical images with labeled variables. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a pipe reference and calculating device according to the present invention. 
       FIG. 2  is a block diagram of a pipe reference and calculating device according to the present invention. 
       FIG. 3  is a top plan view of a pipe reference and calculating device according to the present invention. 
       FIG. 4  is a flow chart for operation of the “calc” key of the pipe reference and calculating device of the present invention. 
       FIG. 5A  is a flow chart for operation of the “reference” key of the pipe reference and calculating device of the present invention. 
       FIG. 5B  is an example of a display screen resulting from pressing the “reference key” of the pipe reference and calculating device of the present invention. 
       FIG. 6A  is a flow chart for operation of the “offset” key of the pipe reference and calculating device of the present invention. 
       FIG. 6B  is an example of a display screen resulting from pressing the “offset” key of the pipe reference and calculating device of the present invention. 
       FIG. 6C  is an example of a display screen for a  450  offset calculation using the pipe reference and calculating device of the present invention. 
       FIG. 7A  is a flow chart for operation of the “layout” key of the pipe reference and calculating device of the present invention. 
       FIG. 7B  is an example of a display screen resulting from pressing the “layout key” of the pipe reference and calculating device of the present invention. 
       FIG. 8A  is a flow chart for operation of the “convert key” of the pipe reference and calculating device of the present invention. 
       FIG. 8B  is an example of a display screen resulting from pressing the “convert” key of the pipe reference and calculating device of the present invention. 
       FIG. 9A  is a flow chart for operation of the “right triangle solve” key of the pipe reference and calculating device of the present invention. 
       FIG. 9B  is an example of a display screen resulting from pressing the “right triangle solve” key of the pipe reference and calculating device of the present invention. 
       FIG. 10A  is a flow chart for operation of the “circle solve” key of the pipe reference and calculating device of the present invention. 
       FIG. 10B  is an example of a display screen resulting from pressing the “circle solve” key of the pipe reference and calculating device of the present invention. 
       FIG. 11A  is a flow chart for operation of the “arc solve key” of the pipe reference and calculating device of the present invention. 
       FIG. 11B  is an example of a display screen resulting from pressing the “arc solve key” of the pipe reference and calculating device of the present invention. 
   

   Similar reference characters denote corresponding features consistently throughout the attached drawings. 
   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The present invention is pipe reference and calculating device. The invention disclosed herein is, of course, susceptible of embodiment in many different forms. Shown in the drawings and described herein below in detail are preferred embodiments of the invention. It is to be understood, however, that the present disclosure is an exemplification of the principles of the invention and does not limit the invention to the illustrated embodiments. 
   The present invention, represented in  FIG. 1 , is a pipe reference and calculating device having a software application adapted to assist in the fabrication of pipe and pipefitting related tasks of all types, generally represented as  20  in the drawings. The device  20  calculates the cut length for a vast array of piping offsets and solves pipefitting problems involving arcs, triangles, and circles. The device  20  is provided with a handheld case housing the calculator. The device  20  includes additional keys performing special functions not found on traditional scientific calculators. Keys for these functions are related to the fabrication of pipe and pipefitting related tasks and include a reference key  31  allowing a user to search a variety of reference topics to obtain detailed information about a particular subject; an offset key  33  that brings up a list of offset types to scroll through; a layout key  35  that brings up a list of common piping problems to scroll through; a trig key  55  that brings up a complete trigonometric table to scroll through; and a conversion key  57  that converts from one unit of measurement to another unit of measurement. 
   Additional keys for these functions include a right triangle solve key  67  for solving right triangles; a circle solve key  71  for solving circles; an arc solve key  75  for solving arc length; a feet/in key  61  for displaying the calculation in feet and inches; a fraction bar  65  for inserting a fraction bar when the calculator is in feet and inches mode; a files key  69  that brings up a list of previously saved files; and a save key  73  that saves the information on the screen  25 . Each key will be discussed later in greater detail. 
   Turning briefly now to  FIG. 2 , a block diagram illustrates the basic components of the present invention. The device  20  includes a processor  115 , a display screen  25 , an input device  100 , and memory  120 . The display screen  25  and the input device  100  are electrically coupled to the processor  115 . The display screen  25  may be, e.g., a Liquid Crystal Display (LCD). The input device  100  comprises a keypad with a variety of buttons. 
   Each button operates an electrical switch controlling a circuit which sends an input signal to the processor  115  in order to carry out a desired function or operation. The display screen  25  has a large display area to accommodate drop down menus and visual aids, providing a graphical interface. Memory device  120  is also electrically coupled to processor  115 . Memory deice  120  may include areas of read only memory (ROM) and random access memory (RAM) for permanent and temporary memory storage, respectively. A software application is stored in the memory device  120 , and when executed by the processor  115 , the software application provides a reference source and a guide for layout information to be used in the fabrication of pipe and pipefitting related tasks of all types. 
   Turning now to  FIG. 3 , the device  20  includes most of the keys found on many scientific calculators, including: alphanumeric keys 0-9 generally represented by  77 ; on/off keys  37 ; a clear key  38  for clearing the screen  25 ; trigonometric keys  41  for performing basic trigonometric functions, such as sine, cosine, and tangent functions; a second key  39  for performing a secondary function for the next key depressed of certain keys, such as the inverse sine, inverse cosine function, or inverse tangent obtained when depressing the second key  39  and then a trigonometric key  41 ; scroll arrow keys  43 ,  45 ,  47 ,  49  for allowing a user to navigate through the various menus and lists or to move a cursor; an enter key  51  for bringing up the next list, screen, prompt or answers to problems; a tab key  53  for moving a cursor from point to point in the display; algebraic function keys (squares, square roots, reciprocals)  59 ; operational keys  81 , including division, multiplication, subtraction, addition, and equality signs; a % key  78 ; and +/− key  79 . 
   Referring briefly back to  FIG. 1 , a more detailed description of the additional keys performing special functions not found on traditional scientific calculators is given. The trig key  55  brings up a complete trigonometric table to scroll through. This allows users who have become accustomed to looking up trigonometric data in written tables to continue to do so. Files key  69  brings up a list of previously saved files. A user can scroll through the list until the desired file is found. By pressing the enter key  51  when the desired file is highlighted, the calculator  20  will bring the file up from memory. The save key  73  saves the information on the screen into a file. When the save key  73  is pressed, a cursor will appear in the lower portion of the screen  25 . A user can then type a number for a file name, or by pressing the alfa key  27  the user can then type notes and file name using the second function of the number keys  77 . The decimal key  58  will cause the calculator to display measurements in decimals. The feet and inches key  61  causes the calculator  20  to display measurements in feet and inches. The fraction bar  65  is pressed to insert the fraction bar when the calculator  20  is in feet and inches mode. 
     FIG. 4  shows a flow chart describing the function of the calculation or “calc” key  29 . When the calculation key  29  is pressed at step  202 , processor  115  checks if device  20  is already functioning as a scientific calculator, that is, functioning in calculator mode, at step  204 . If device  20  is in calculator mode, any operands and the calculator registers, including any results or instructions for pending calculator functions, are cleared at step  206 , and processor  115  enters or re-enters calculator mode at step  208 . If device  20  is not in already in calculator mode, processor  115  enters calculator mode at step  208 . Hence, pressing the “calc” key has the effect of clearing any pending calculations and re-starting the scientific calculator mode. 
     FIGS. 5A-5B  illustrate operation of the reference key  31 .  FIG. 5A  shows a flow chart of operation when the reference key  31  is pressed. Upon pressing the reference key  31  at step  212 , a general or broad list of reference subjects is provided at step  260 . A keyword search prompt is simultaneously displayed adjacent a keyword text block at step  285 , so that the user can obtain access to the desired reference information. This can occur by selecting menu entries at step  265  through operation of scroll keys  43 ,  47 , and the enter key  51 . This can also occur by pressing the tab  53  or horizontal scroll key  45  to move to the keyword search, and then using the alfa  27 , alphanumeric  77 , and enter  51  keys to perform a keyword search at step  290 . 
   If a menu subject is selected at step  265 , the user is presented with a further defined list of reference subjects under the first subtitle at step  275 . Once a desired general reference subject has been chosen at step  280 , the result is displayed at step  295 . If the user entered a keyword search term at step  290 , the user may be presented with a broad general reference menu at step  260 , or a detailed reference subject menu at step  280 , depending upon the keyword entered. 
     FIG. 5B  provides an example of the display screen  25  resulting from the operation of the reference key  31 . As described above, upon pressing the reference key  31 , the processor  115  provides two methods of searching for desired reference material upon display screen  25 , including a drop-down menu reference list  320  to scroll through providing general reference list menu  330 . Only three reference topics are shown in the list box  330  in the drawing, the number of topics displayed being dependent upon screen size. The current selection may be indicated by highlighting the selection with bold print (as shown), by reverse video, by color-coding, by a selection arrow  332 , or any other manner. Additional selections may be viewed by scrolling through the list using arrow keys  43  and  47  until the desired selection is highlighted, and then pressing the enter key  51 . 
   The submenu list box  335  lists more detailed topics in the category selected, which is updated as the selection in the general menu list  330  is changed. In the example provided, the general drop-down reference menu list  330  is a plastics selections usage category, and the submenu  335  has more detailed topic categories of plastic pipes, including the subcategories of ABS, CPVC, PP, PPE, or PVC pipe. The currently selected subcategory topic may also be indicated by highlighting the selection in bold print (as shown), by reverse video, by color-coding, by a selection arrow  337 , or any other manner. The user scrolls to the desired subcategory in submenu list box  335 , selects the subcategory by pressing the enter key  51 , and the desired reference information is displayed (not shown). An exemplary keyword search prompt  325  is also shown on the display screen  25  when the reference key  31  is pressed. The user may leave the reference mode by pressing the “calc” key  29 . 
     FIG. 6A  shows a flow chart illustrating operation of the offset key  33 . Upon pressing the offset key at step  350 , the device  20  displays a list of offset types at step  355 . An offset type may then be selected at step  357  in the same manner as a menu selection described with regard to  FIG. 5B  above. An illustration of the offsets with variables is then displayed at step  360 . Each offset type and measurements for the offset are entered in step  365  for the processor  115  of the device  20  to calculate the pipe offset cut lengths in step  370 . The result may be automatically calculated and displayed after entering sufficient measurements. Alternatively, a keyword search may be done at step  375  by tabbing to the keyword search prompt, entering the search term at step  385 , and pressing the enter key  51  at step  390 . The user is then directed to the display offset types list of step  355 , which will display a portion of the offset list that includes the search term. 
     FIGS. 6B-6C  provide an example of the display screens  25  resulting from the operation of the offset key  33 . In  FIG. 6B , an example of a search for a 45° offset is implemented. The search is carried out by selecting 45° offset from list menu  420 . Alternatively, a search for a 45° offset may be input into search prompt  405 . In  FIG. 6C , an illustration of the display screen  25  which appears when a 45° offset calculation is shown to include a graphical illustration  425  of a 45° pipe offset provided with variable letters where the measurements are to be taken for the run R or offset O, and for the location of the travel T to be calculated. A corresponding list of variable letters  445  is below the illustration. 
   The user is prompted to enter the pipe type (i.e. cast iron, butt weld, copper, etc.) at list box  435  and size of pipe being worked with (i.e., 2″, 1½″, 48″, etc.) via list box  440 . Upon tabbing to the variable letters  445  and typing in either the run or the offset value and the enter key  51 , the calculator computes and displays the center-to-center travel length T and cut length C. The calculator automatically subtracts the take outs from T and this is represented by C. Other standard pipefitting offset calculations, such as around circular, around square corners, and rolling offsets, are performed in similar fashion using the offset key  33  to access the appropriate software routine as described above. 
     FIG. 7A  shows a flow chart illustrating operation of the device  20  when the layout key  35  is pressed at step  450 . Upon pressing the layout key  35 , a list of common piping problems is displayed on the screen at step  455  so that the user may scroll through the list at step  460 . The user selects the pipe problem at step  465  by pressing the enter key  51 , and the device  20  displays detailed instructions to solve the pipe problem at step  470 .  FIG. 7B  provides an example of the display screens  25  resulting from a search for common piping layout problems. The search for common piping layout problems is performed by conducting a keyword search via prompt  510  or common piping problems layout drop down list menu  505 . In the example, a cut angle is selected from the drop down list menu  505 . 
     FIG. 8A  shows a flow chart describing the operation of the convert key  57 . Upon pressing the convert key  57  at step  520 , the device displays a convert screen at step  525 , as exemplified in  FIG. 8B . The user moves the cursor or focus to select a category of measurement (e.g., distance, weight, etc.) and enters the selection at step  527  by pressing the enter key  51 . The user then enters the number to be converted at step  530  and the units of measurement at step  535 . The user then enters the desired units of measurement the number is to be converted to at step  540 , presses the enter key at step  545 , and the device  20  performs the conversion and displays the numerical result in the desired units of measurement at step  550 . 
     FIG. 8B  provides an exemplary display screen  25  that appears when the convert key  57  is pressed. A menu  625  of categories of units of measurement is displayed across the top of the screen  25 . The user may select the desired category by tabbing and operation of the arrow cursor control keys to highlight the desired category, and then select the category by pressing the enter key  51 . A first edit box  627  is provided for entering the numerical units of the quantity to be converted, and a list box  628  or scrollable list box is presented beneath the edit box  627  for selection of the dimensional units of the quantity to be converted. A second edit box  629  or a text box is provided adjacent the first edit box  627  for display of the numerical result, and a second list box  631  is provided beneath edit box  629  for selection of the dimensional units desired. The screen  25  may also include a keyword search prompt  633  for help in measurement units or other aspects of operation of the convert key  57 . 
     FIG. 9A  shows a flow chart of the operation of the right triangle solve key  67 . Upon pressing the right triangle solve key  67  at step  634 , the device  20  displays a screen  25  having a graphical depiction of a right triangle with variables labeling the sides and angles of the triangle and edit boxes for entry of the known values at step  635 . The known variables are entered at step  640 . The enter key  51  is pressed at step  645 , and the device computes the unknown value and displays the results at step  650 . 
     FIG. 9B  is an exemplary display screen  25  showing the right triangle solve key in operation. Pressing the right triangle solve key  67  results in a display screen having a graphical image  665  of a right triangle. All of the sides and angles are labeled with variables. Below the triangle  665 , there is a corresponding list of variables  670 . The user types in the known parts within the list of variables  670 , and the device  20  solves the remaining sides and angles. The user navigates between the variables using the tab key  53  and arrow cursor control keys  43 ,  45 ,  47 , and  49 . The screen  25  may have an edit box next to the variable currently having the focus, or the screen  25  may simply have a blinking underscore or cursor next to the variable having the focus to prompt for entry of a measurement, the user entering the numerical digits followed by the enter key  51 . 
     FIG. 10A  shows a flow chart describing operation of the circle solve key  71 . Upon pressing the circle solve key  71  at step  702 , the device  20  presents a display screen  25  having a graphical image of a circle with variables noted on the figure and a list of variables for entry of known measurements at step  705 . The known variables are input at step  710 . After the enter key  51  is pressed at step  715 , the device  20  computes and displays the remaining unknown parts of the circle at step  720 . 
     FIG. 10B  shows an exemplary display screen  25  illustrating operation of the circle solve key  71 . Pressing the circle solve key  71  produces a display screen  25  having a graphical image of a circle  755 . All parts of the circle  755  are labeled with a variable. A corresponding list of variables, such as the area  760 , diameter  765 , and circumference  770 , etc., are below the circle  755 . The user types in the known parts of the circle and the device  20  solves the remaining parts of the circle  755 . 
     FIG. 11A  shows a flow chart describing operation of the arc solve key  75 . Upon pressing the arc solve key  75  at step  802 , a graphical image of an arc is displayed labeled with variables along with a list of variables for entry of the known values at step  805 . The known variables are entered at step  810 . After pressing the enter key  51  at step  815 , the device  20  computes and displays the unknown remaining parts of the arc at step  820 . 
     FIG. 11B  shows an exemplary display screen  25  illustrating operation of the arc length solve key  75 . Pressing the arc key  75  causes the device  20  to present a graphical image of an arc  827  on the display  25 . All parts of the arc  827  are be labeled with variables. Below the arc  827  is a corresponding list of variables  830 , e.g., radius, angle, chord, and arc length. The user enters numerical digits for the known values, either into an edit box or at a blinking cursor. Upon pressing the enter key  51 , the calculated value for the arc length is displayed in the variable list  830 . 
   It will be understood that the display screens shown in the drawings are exemplary only, and that details of the display screen  25  and the interface for the entry of data and menu displays may vary in different implementations of the present invention, provided that the display screen  25  shows graphical images labeled with variables to provide an easy to use interface for solving pipefitting calculations. 
   While the invention has been described with references to its preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the true spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teaching of the invention without departing from its essential teachings.