Abstract:
A novel apparatus and method for use in measuring surface slope is disclosed. In a preferred embodiment, the measurement apparatus includes a fluid case having an arch of flat segments forming a sloped ceiling. In another preferred embodiment, a smooth curve, instead of a series of flat segments, is formed by reducing the length, and increasing the number, of the constant slope flat segments. And in a preferred embodiment, the apparatus provides a mechanism for compensating for any expansion or contraction of the fluid in the fluid case. A method for measuring the slope of a surface includes providing a measurement apparatus, placing the measurement apparatus adjacent the surface and reading an indicator corresponding to the slope of the surface.

Description:
REFERENCE TO PENDING PRIOR PATENT APPLICATION 
     This patent application is a continuation-in-part of pending prior U.S. patent application Ser. No. 09/741,935, filed Dec. 20, 2000 by Hans U. Roth et al. for UNIVERSAL NON-ELECTRONIC MULTI-SECTIONAL GRADIENT METER AND INCLINOMETER AND METHOD OF USE, which patent application is hereby incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to measurement tools in general. More particularly, this invention relates to measurement tools used to non-electronically measure surface gradient and inclination. 
     BACKGROUND OF THE INVENTION 
     Tools for measuring surface gradient or surface inclination are well known in the art. For example, on construction sites, and in other situations, accurate and precise measurement must often be considered for the gradient and the inclination of a surface. Currently, water-level instrumentation and electronic instrumentation are typically used to indicate whether or not a particular surface is level. 
     Currently, water-level instrumentation generally does not accurately indicate the percentage of gradient and amount of inclination for a non-level surface. 
     Electronic instrumentation is used in some applications for measuring the gradient and inclination of surfaces. However, many applications are in relatively harsh or rough environments, such as construction sites, and the use of electronic instrumentation is frequently not practical due to various factors. These factors include environmental factors, such as shock sensitivity, and the replacement cost for broken or damaged electronic instrumentation. 
     The foregoing demonstrates the need for novel instrumentation to measure surface gradient and surface inclination. Ideally, the measurement instrumentation should be highly accurate and precise for measuring surface gradient and surface inclination. The measurement instrumentation should also be unaffected by most environmental factors. Furthermore, the measurement instrumentation should be inexpensive to manufacture. 
     SUMMARY OF THE INVENTION 
     These and other objects are addressed by the present invention, which comprises a novel apparatus and method for use in measuring surface slope, including gradient and inclination, in such places as a construction site. The present invention provides a universal non-electronic multi-sectional gradient meter and inclinometer. 
     The measurement apparatus includes a fluid case containing a fluid and an indicator, calibrated markings on the fluid case corresponding to the indicator, and a sloped ceiling within the fluid case. 
     In a preferred embodiment, the sloped ceiling includes several portions forming an arch and each portion having a constant slope. From a portion corresponding to zero slope, the other portions slope downwardly from the portion corresponding to zero slope toward each end of the fluid case, respectively. The portions also have a progressively increasing slope from the zero slope portion to each end, respectively. In this configuration, an arch of flat segments is formed in the profile view of the fluid case&#39;s ceiling. 
     In another preferred embodiment, the sloped ceiling includes several portions forming an arch, each portion having a constant slope along its length. From one end of the fluid case and a portion corresponding to zero slope, each of the other portions slope away from the zero slope portion toward the other end of the fluid case and have progressively increasing slopes. As such, the zero slope portion is located in one end of the fluid case and an arch of flat segments is formed in the fluid case&#39;s ceiling. 
     In another preferred embodiment, the portions in the sloped ceiling are shortened, and additional portions are added, so as to form a smooth curve instead of a series of flat segments. 
     In still another preferred embodiment, a smooth curve, instead of a series of flat segments, is formed in the sloped ceiling by reducing the length, and by increasing the number, of the constant slope portions. 
     And in still another preferred embodiment, the fluid case is formed so as to provide a mechanism for compensating for any expansion or contraction of the fluid in the fluid case. 
     A method for measuring the slope of a surface includes providing a measurement apparatus adjacent the surface, placing the measurement apparatus, and reading an indicator corresponding to the slope of the surface. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other objects and features of the present invention will be more fully disclosed or rendered obvious by the following detailed description of the invention, which is to be considered together with the accompanying drawings wherein like numbers refer to like parts and further wherein: 
     FIG. 1 is a side elevational view of a novel measurement instrument for determining the slope of a surface; 
     FIG. 2 is a top plan view of the measurement instrument of FIG. 1; 
     FIG. 3 is an end view of the measurement instrument of FIG. 1; 
     FIG. 4 is a cross-sectional view taken along line  4 — 4  of FIG. 2; 
     FIG. 5 is a cross-sectional view taken along line  5 — 5  of FIG. 2; 
     FIG. 6 is a side elevational view of a measurement instrument for determining the slope of a surface; 
     FIG. 7 is a top plan view of the measurement instrument of FIG. 6; 
     FIG. 8 is a cross-sectional view taken along line  8 — 8  of FIG. 7; 
     FIG. 9 is a side elevational view of the measurement instrument of FIG. 1 attached to a prior art level; 
     FIG. 10 is a top plan view of the measurement instrument and prior art level of FIG. 9; 
     FIG. 11 is an end view of the measurement instrument and prior art level of FIG. 9; 
     FIG. 12 is a side elevational view of the measurement instrument of FIG. 1 incorporated within a prior art level; 
     FIG. 13 is a top plan view of the apparatus of FIG. 12; 
     FIG. 14 is a cross-sectional view taken along line  14 — 14  of FIG. 12; 
     FIG. 15 is a side elevational view of the measurement instrument of FIG. 6 in conjunction with a prior art level; 
     FIG. 16 is a top plan view of the measurement instrument and prior art level of FIG. 15; 
     FIG. 17 is a schematic view of a ceiling configuration of the measurement instrument of FIG. 1 in which the regions X, Y, Z each have a constant slope of increasing magnitude to one another from the instrument&#39;s level center toward each of the ends, respectively; 
     FIG. 18 is a side view, partially in section, of an alternative form of measurement instrument also formed in accordance with the present invention; 
     FIG. 19 is an enlarged end view of one end of the measurement instrument shown in FIG. 18; 
     FIG. 20 is a sectional view taken along line  20 — 20  of FIG. 19; 
     FIG. 21 is a schematic view showing how the indicator gas bubble may be enlarged as desired; and 
     FIG. 22 is a schematic view showing how the indicator gas bubble may be reduced as desired. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to FIGS. 1-16, a measurement apparatus  5  is shown for measuring the gradient of inclination of a surface (not shown). Measurement apparatus  5  includes a fluid case  10  having an indicator  15 , such as an air bubble, and a ceiling  20 . Indicator  15  reacts to changes in the elevation of the ceiling  20  as measurement apparatus  5  is disposed on a surface. Ceiling  20  is formed having multiple sections  25 . From a portion  30  of ceiling  20  in which indicator  15  signals that apparatus  5  is on a zero slope, or a level surface, sections  25  slope progressively downward toward first end  35  and toward second end  40 , respectively. In one form of the invention, each of the sections  25  has a constant slope along its own length. In another form of the invention, sections  25  are integral to one another so as to form a curved surface. 
     Still looking at FIGS. 1-16, in a preferred embodiment of the invention, fluid case  10  is configured with a wider cross-sectional width along a bottom surface  45  (FIG. 5) and a narrower cross-sectional width along an upper portion  50  adjacent ceiling  20 . This configuration is advantageous in that the motion and display of indicator  15  is amplified to indicate the gradient or the inclination of a portion of the surface measured by apparatus  5 . Apparatus  5  uses a fluid composition  55  similar to, or the same as, a standard water-level. 
     Now looking at FIGS. 1-5, apparatus  5  is shown with measurement units  65  in the configuration of a gradient meter. In this embodiment, measurement units  65  include 0.25, 0.5, 1.0, 2.0, 2.5, 3.0 percentage of elevation deviation from exact level 0.0 towards each end  35  and  40 , respectively. In other words, when apparatus  5  is placed on a surface and indicator (e.g., air bubble)  15  settles under the measurement unit  65  labeled “2.5”, the surface will be 2.5 percent off horizontal. Apparatus  5  may also include other measurement units  65 . 
     Now looking at FIGS. 6-8, another preferred embodiment of apparatus  5  is shown in the configuration of an inclinometer. In this embodiment, measurement units  65  include 0°-90° indications, in units of 5°. 
     Referring now to FIGS. 9-17, in still another preferred embodiment, novel apparatus  5  is shown in several configurations with a conventional level device  70 . 
     In FIGS. 9-11, novel apparatus  5  is detachably attached to the top of conventional level device  70 . Conventional level device  70  has a prior art fluid filled chamber  75  including a bubble  80  to indicate zero slope of a surface when bubble  80  is between lines  85 . In this configuration, novel apparatus  5  is attached to conventional level device  70  using attachment means  90 . Attachment means  90  include, but are not limited to, suction cups and other temporary or permanent mounting means generally known. In one form of the invention, an aftermarket kit contains apparatus  5  and attachment means  90  to retrofit existing conventional level devices. 
     Looking next at FIGS. 12-14, novel apparatus  5  is shown incorporated within an otherwise-conventional level device  70 . In a preferred embodiment, conventional level device  70  and apparatus  5  are manufactured integral with one another as shown. In another preferred embodiment, conventional level device  70  and apparatus  5  manufactured as separate components such that novel apparatus  5  may be quickly and easily replaced if broken or defective. 
     Now referring to FIGS. 15 and 16, a preferred embodiment of apparatus  5  is shown in combination with conventional level device  70 . Apparatus  5  is mounted at an end of level  70  such that the inclination is indicated by measurement units  65  from above and to the side. The embodiment shown in FIGS. 15 and 16 is similar to the embodiment shown in FIGS. 6-8 above, except that apparatus  5  is attached to the end of a conventional level device  70 . In the embodiment of FIGS. 15 and 16, apparatus  5  may be secured to level device  70  during manufacture or apparatus  5  may be sold in a kit with attachment means (not shown) for attachment to an existing level  70 . 
     Looking now at FIG. 17, three sections  25 , including regions X, Y, Z, are each shown on both sides of zero slope portion  30 . Regions X, Y, Z, on each side of portion  30 , each slope progressively downward from portion  30  toward first end  35  and second end  40 , respectively. Each portion is shown with a constant slope over each region X, Y, Z. However, as discussed above, each of the regions X, Y, Z may itself be configured to have an increasing slope along its own length, so as to essentially form a smooth curve over the expanse from portion  30  toward first end  35  and second end  40 . A configuration between these two embodiments is accomplished by successively reducing the length of regions X, Y, Z and adding additional sections  25 . 
     It should also be appreciated that in FIG. 17, zero slope portion  30  is shown as the apex of two adjacent sloped sections  25  (i.e., regions X); however, if desired, zero slope portion  30  could also comprise a longitudinally extending surface, of zero slope, extending between adjacent sloped sections  25  (i.e., regions X). 
     In a preferred embodiment of the invention (not shown), a single unit is disclosed with a first apparatus  5  having a first set of measurement units  65  (e.g., apparatus  5  such as shown in FIGS. 1-5) and a second apparatus  5  having a second set of measurement units  65  (e.g., apparatus  5  such as is shown in FIGS.  6 - 8 ). In one configuration, first and second measurement units allow simultaneous measurement on a single surface of its gradient, as a percentage of elevation deviation, and of its inclination, as measured in degrees. Alternatively, first and second measurement units are configured with differing scales. As such, precise measurements can be taken over multiple ranges, rather than one narrow range. 
     In one preferred embodiment of the present invention, indicator  15  is formed by a gas bubble floating within a fluid  55 . This arrangement is relatively simple and inexpensive to manufacture and reliable in operation. However, depending on the materials and/or compositions used to form gas bubble  15  and fluid  55 , and depending on the environmental conditions apparatus  5  may be used in (e.g., 0° F. through 110° F.), gas bubble  15  and/or fluid  55  may experience significant thermal expansion or contraction, resulting in a significant increase or decrease in the size of gas bubble  15 . Small changes of this type will generally not significantly affect the utility of apparatus  5 ; however, excessive shrinkage of gas bubble  15  may render the indicator  15  difficult to read, or excessive expansion of gas bubble  15  may render indicator  15  ambiguous as to its precise location, etc. 
     To this end, and looking next at FIGS. 18-22, there is shown an alternative construction which permits the size of indicator  15  to be increased or decreased as desired. More particularly, in FIGS. 18-20 there is shown apparatus  5  which is generally similar to the apparatus  5  shown in FIGS. 1-5, except that a wall  100  separates main fluid chamber  105  from a supplemental fluid chamber  110 , with an aperture  115  connecting supplemental fluid chamber  110  from main fluid chamber  105 . Supplemental fluid chamber  110  is used to store a supplemental gas bubble  15 A. By passing gas between supplemental gas bubble  15 A and indicator gas bubble  15 , the size of indicator gas bubble  15  can be adjusted so as to maintain it at the desired size. 
     More particularly, and looking next at FIG. 21, suppose thermal conditions have caused the size of indicator gas bubble  15  to decrease to the point where it is adversely affecting use of apparatus  5 . In this case, gas may be passed from supplemental gas bubble  15 A to indicator gas bubble  15  by turning apparatus  5  as such is shown in FIG. 21, so that some gas will escape from supplemental fluid chamber  110  into main fluid chamber  105  via aperture  115 . This will have the desired effect of increasing the size of indicator gas bubble  15 . 
     Conversely, and looking next at FIG. 22, suppose thermal conditions have caused the size of indicator gas bubble  15  to increase to the point where it is adversely affecting use of apparatus  5 . In this case, gas may be passed from indicator gas bubble  15  to supplemental gas bubble  15 A by turning apparatus  5  such as shown in FIG. 22, so that some gas will escape from main fluid chamber  105  into supplemental fluid chamber  110  via aperture  115 . This will have the desired effect of decreasing the size of indicator gas bubble  15 . 
     In this way, the size of indicator gas bubble  15  may be adjusted by the user so as to compensate for thermal conditions. 
     In order to prevent aperture  115  from unintentionally passing gas during normal use of device  5 , aperture  115  is preferably formed on the bottom end of wall  100  and sized so that it will not be contacted by either indicator gas bubble  15  or supplemental gas bubble  15 A during normal use of the device. On one preferred embodiment, aperture  115  comprises a gap extending between the bottom end of wall  100  and the floor of main fluid chamber  105  and supplemental fluid chamber  110 . 
     The present invention is not limited to the foregoing specific embodiments, but also encompasses all improvements and substitutions within the scope of the claims.