WO2009137692A1

WO2009137692A1 - Improved level vial

Info

Publication number: WO2009137692A1
Application number: PCT/US2009/043164
Authority: WO
Inventors: William L. Litchfield
Original assignee: Litchfield William L
Priority date: 2008-05-09
Filing date: 2009-05-07
Publication date: 2009-11-12
Also published as: WO2009136947A1

Abstract

An improved level vial comprising a cylindrical vial containing a fluid and a straight member. The straight member has a specific gravity less than the specific gravity of the fluid, a length less than the inside diameter of the cylindrical vial, and a thickness less than the inside depth of the cylindrical vial. The cross section of the straight member could be circular or square or rectangular. The ends of the straight member could be curved or pointed. There could be a transverse scribe mark on the straight member. Further the center of the straight member could be pivotally attached to the center of the vial. A level made with this improved level vial includes a frame having at least one plane measuring surface and at least one side at right angles to each other. The frame also includes a level indicating mark on the side.

Description

Improved Level Vial Technical Field

The present invention relates to the field of levels and more particularly to the field of level vials. This application is a continuation of PCT Application No. PCT/US2008/063317, filed 09 May 2008, the entire specification, claims and drawings of which are incorporated herein by reference.

Background Art

Most commonly, spirit levels are employed to indicate how horizontal (level) or how vertical (plumb) a member or surface is. Different types of spirit levels are used by carpenters, stone masons, bricklayers, other building trades workers, surveyors, millwrights and other metalworkers, and serious videographers.

The first spirit levels had two banana-shaped curved glass vials at each viewing point and were much more complicated to use. In the 1920s, Henry Ziemann, the founder of Empire Level, invented the modern level with a single vial. These vials, common on most ordinary levels today, feature a slightly curved glass tube with scribe lines at right angles to the long axis of the tube. The tube is incompletely filled with a liquid, usually yellow-colored ethanol, leaving a bubble. Ethanol is used because of its low freezing point, -114°C, which prevents it from freezing in cold weather.

A large number of inventors have tried to improve on the construction of levels.

US Patent No.2,282,166 discloses a plumb and level made in sections. The invention primarily concerns the mechanism that joins the sections together. No particular mention is made of where the scribe lines are located.

US Patent No. 2,535,791 discloses a level with a magnetic securing means. No particular mention is made of where the scribe lines are located.

US Patent No.3,104,477 discloses an extendible level. No particular mention is made of where the scribe lines are located but Figure 2 indicates that they are on the level vials.

US Patent No. 3,956,934 discloses a liquid level indicator for a container of pressurized liquid. US Patent No. 4,124,940 discloses a particular method of assembling a level. No particular mention is made of where the scribe lines are located but Figure 1 indicates that they are on the level vials.

US Patent No. 4,979,310 discloses a particular level construction which eliminates the need for painting and eliminates problems resulting from shrinkage of plastic covers. No particular mention is made of where the scribe lines are located but Figure 1 indicates that they are on the level vials.

US Patent No. 5,199,177 discloses the construction of a lighted level. No particular mention is made of where the scribe lines are located but Figure 1 indicates that they are on the level vials.

US Patent No. 5,412,876 discloses a protective end cap for a spirit level. No particular mention is made of where the scribe lines are located but Figure 1 indicates that they are on the level vials.

US Patent No. 5,479,717 discloses construction of a slip resistant level. No particular mention is made of where the scribe lines are located.

US Patent No. 5,575,073 discloses an apparatus for setting a level plane which includes a spirit level. While the vials are mentioned no particular mention is made of the scribe marks.

US Patent No. 508,762 discloses a spirit level with laterally adjustable end sections.

US Patent No. 6,324,767 discloses a sight level.

US Patent No. 6,381 ,859 discloses a particular construction for a level. Figures 1 and 2 show the scribe marks on the bubble level vials.

US Patent No. 6,434,842 discloses a sanding and rasping level. This device is a level with sandpaper on one surface. The level vials are described as "typical" and Figures 1 and 5 show scribe lines on the longitudinal vial.

US Patent No. 6,577,388 discloses a laser level including bubble levels. No particular mention is made of where the scribe marks are located. US Patent No. 6,915,586 discloses a box level with hang openings. No particular mention is made of where the scribe lines are located but Figures 1 and 2 indicate that they are on the level vials.

US Patent No. 6,988,320 discloses a particular level construction. Holes for insertion of level vials are mentioned.

US Patent No. 6,988,406 discloses a system and method for detection of liquid level in a tank.

US Patent No. 7,150,106 discloses a level with removable end caps and holes for insertion of level vials. The specification includes no description of the level vials.

US Patent No. 7,204,029 discloses a particular level construction including structures for receiving magnets and level vials covered by lenses. The level vials are described as having "spaced line indicators of usual type". See column 7, lines 3-6.

US Patent No. 981 ,434 discloses a float gage.

US Patent No. D388,719 discloses a spirit level.

US Patent No. D457,446 discloses a laser level. Scribe marks are not visible.

US Patent No. D479,139 discloses a level. Scribe marks appear to be on the level vials.

US Patent No. D503,635 discloses a spirit level. Scribe marks are visible on the level vials.

US Patent No. D509,761 discloses a laser level but level vials are not readily discernible.

US Patent No. D525,543 discloses a spirit level with scribe marks clearly on the level vials.

US Patent No. D528,022 discloses a laser measuring device with a circular bubble level having a circular scribe mark on its top.

US Patent No. D533,093 discloses a laser measuring device. Figures 3, 5 and 6 show a bubble level having several scribe marks.

US Patent No. D535,576 discloses an electronic spirit level with level vials having scribe marks. US Patents Nos. 6,675,490 and 6,792,686 disclose a construction of a level using a thin wall construction. The construction includes horizontal and vertical vial assemblies but no particular mention is made of where the scribe lines are located but in Figure 10, they are shown on the vial.

US Patent No. 4,164,077 discloses level indicating devices wherein at least a side portion of a bubble cavity is defined by a reflecting surface having at least a linear cross section lying generally in a plane aligned with or paralleling a light source and a bubble image observer (i.e. person or sensor).

US Patent No. 3,956,831 discloses an attitude meter which measures the orientation of a plane surface with respect to the magnetic North direction and a horizontal plane. The meter includes a hollow transparent sphere containing liquid for supporting a compass and a vertical indicator, combined with a rotatable arcuate scale for facilitating visual reading of the compass and relative position of the vertical indicator. More particularly, the arcuate scale includes vertical orientation indicia and is mounted for rotational displacement to a position immediately adjacent the vertical indicator. By this arrangement the vertical angle of the surface being measured may be read directly from the arcuate scale and the direction of inclination relative to the magnetic North may be determined from the point of intersection of the arcuate scale and the liquid supported compass.

US Patent No. 2,635,350 discloses a leveling device comprising an elongated base having a pair of longitudinal side legs disposed in inverted V relationship and a top defined by the apex of the V, the legs having co-planar fiat level checking faces at the bottom edges 15 thereof spaced apart co-planar flat level checking faces at the inner surface of each leg and flat level checking faces adjacent the outer sides of the legs at right angles to the inner faces and the top including a raised handle portion ex- 20 tending longitudinally from, adjacent one end of the base to the raid-region thereof, the outer surface of the handle tapering toward the one end of the base.

One of the most critical aspects of manufacturing levels is to ensure that the long axis of the vial is parallel to the measuring surface of the level. Another is keeping the long axis of the vial and the measuring surface parallel throughout long use and possible abuse of the level. Hopkins Manufacturing Corporation of Emporia, Kansas, sells a model 09515 level vial that is roughly square and can be used for determining plumb and level of members and level of surfaces. It is made from injection molded plastic so it is not a very precision instrument but very inexpensive to produce.

Stabila, Inc. of Germany sells extremely high precision and expensive levels. Their levels incorporate very high tech methods of clamping the vial into the level frame so that the long axis of the vial is precisely aligned with the measuring surface and so that the orientation of the vial cannot be easily changed during use.

However, all the above listed inventions and improvements utilize vial technology that was developed in the 1920's. There has been no improvement in vial technology since.

Development of a new type of vial which can enable manufacture of high precision levels more inexpensively and with a greater tolerance to abuse represents a great improvement in the field of level manufacturing and satisfies a long felt need of carpenters, stone masons, bricklayers, surveyors, millwrights and others for levels in which they can intuitively place greater trust.

Disclosure of Invention

This invention is an improved level vial comprising a cylindrical vial containing a fluid and a straight member. The straight member has a specific gravity less than the specific gravity of the fluid, a length less than the inside diameter of the cylindrical vial, and a thickness less than the inside depth of the cylindrical vial.

The cross section of the straight member could be circular or square or rectangular. The ends of the straight member could be curved or pointed. There could be a transverse scribe mark on the straight member. Further the center of the straight member could be pivotally attached to the center of the vial.

A level made with this improved level vial includes a frame having at least one plane measuring surface and at least one side at right angles to each other. An improved level vial as described above is affixed within the frame designed so that it is visible from the side. The frame also includes a level indicating mark on the side. The level could have a cladding on the plane measuring surface. The improved level vial of this invention can be made by the following steps:comprising the steps of:

obtaining a cylindrical vial;

obtaining a fluid;

obtaining a straight member the straight member having a specific gravity less than the specific gravity of the fluid, a length less than the inside diameter of the cylindrical vial, and a thickness less than the inside depth of the cylindrical vial;

placing the straight member within the cylindrical vial; and

filling the cylindrical vial with the fluid.

A level containing the improved level vial of this invention can be fabricated by the following steps:

fabricating a frame having at least one plane measuring surface and at least one side at right angles to each other; the frame designed to retain a level vial so that the level vial is visible from the side;

obtaining an improved level vial as described above;

affixing the level vial within the frame; and

applying a level indicating mark to the side of the frame.

Such a level could also have a cladding fastened to the plane measuring surface.

Brief Description of Drawings

Figure 1 is a partial side elevational view of a typical prior art level. Figure 2 is a cross sectional view along the lines 2-2 of Figure 1.

Figure 3 is a side elevational view of a level vial in accordance with this invention.

Figure 3A is a side elevational view of an alternate embodiment of the level vial illustrated in Figure 3.

Figure 4 is a front elevational view of the level vial illustrated in Figure 3.

Figure 5 is a side elevational view of a level vial in accordance with this invention illustrating an alternate end configuration for the straight member.

Figure 6 is a side elevational view of a level vial in accordance with this invention illustrating another end configuration for the straight member.

Figure 7 is a side elevational view of an alternate embodiment of a level vial in accordance with this invention illustrating how the straight member can be a slightly modified bubble level vial.

Figure 8 is a front elevational view of the level vial illustrated in Figure 7.

Figure 9 is a side elevational view of another alternate embodiment of a level vial in accordance with this invention illustrating how the straight member can be a standard bubble level vial with a low specific gravity projection attached to each.

Figure 10 is a front elevational view of the level vial illustrated in Figure 9.

Figure 1 OA is a side elevational view showing how the member and vial can be pivotally attached center to center with a pivot pin.

Figure 10B is a cross sectional view showing how the member and vial can be pivotally attached center to center with mating projections on the inside of the vial and depressions in the sides of the member.

Figure 11 is side elevational view of a level incorporating the level vial of this invention. In this view the level has been placed on a level surface.

Figure 11A is side elevational view of a level incorporating the level vial of this invention placed on a surface that is not level. Figure 12 is a cross sectional view along the lines 12-12 of the level illustrated in Figure 11.

Figure 13 is a side elevational view of a level via which has an oval shape.

Figure 14 is an enlarged cross sectional view along the lines 14-14 of Figure 11

Figure 15A is a side elevational view of a level vial in accordance with this invention with air relief holes.

Figure 15B is a top view of the straight member illustrated in Figure 15A

Figure 16A is a side elevational view of a level vial in accordance with this invention with end air relief vents.

Figure 16B is a top view of the straight member illustrated in Figure 16A

Best Mode for Carrying Out Invention

Figures 1 and 2 illustrate a portion of a typical prior art level 10. Such a level 10 has a frame 14 which has a top plane surface 18, a bottom plane surface 22 and an intermediate web 26. The top and bottom plane surfaces are parallel to each other. Retained within the web 26 is a bubble level vial 30. A variety of different methods are used to retain the level vial 30 within the web 26 but the retaining ring 34 usually protrudes from the web 26. In the portion illustrated in Figures 1 and 2 the level vial 30 is essentially tubular and it is secured within the web 26 so that its longitudinal axis 38 is parallel to the plane surfaces 18, 22. The bubble level vial 30 typically comprises a transparent tube with slightly curved sides 42, preferably made of glass or plastic, which is incompletely filled with a fluid 46 so that a bubble of air 50 remains. The outside surface of the vial 30 is scribed with scribe marks 54, at right angles to the longitudinal axis 38 of the vial 30. The quantity of fluid 46 in the vial 30, and thus the size of the bubble 50, and the distance between the scribe marks 54 are adjusted so the length of the bubble 50 is just about the same size as the distance between the scribe marks 54 when the level 10 and the vial 30 are horizontal.

Although not illustrated, those familiar with the art to which this invention pertains will recognize that another vial 30 may be retained within the web 26 with a longitudinal axis that is at right angles to the top and bottom plane surfaces 18, 22. Such a vial 30 is used to determine plumb. Further, another vial 30 may be retained within the web 26 with a longitudinal axis that is at 45 ⁰ to the one of the plane surfaces 18 or 22. Such a vial 30 is used to determine how close a surface is to 45 °from level or plumb. Those familiar with the art to which this invention pertains will recognize that bubble level vials must have a constant radius which is centered at the axis to be leveled. Alternatively, the bubble level vial reaches its highest arc between the scribe lines. Those familiar with manufacturing techniques will also recognize that it is impossible to fabricate items exactly. Every dimension of an item must be fabricated to a tolerance. Thus the when the terms right angle, parallel, etc. are used in this specification it will be understood that this means within manufacturing tolerances.

Figures 3 and 4 illustrate a first embodiment 100 of a level vial in accordance with this invention. This embodiment 100 includes a cylindrical vial 104 filled with a fluid 108. Also within the vial 104 is a straight member 112. This member 112 has specific gravity less than the specific gravity of the fluid 108 within the vial 104. The length L of the member 112 along its central longitudinal axis 114 is preferably slightly shorter than the inside diameter ID of the vial 104. The width W of the member 112 is preferably slightly less than the depth D of the vial 104. The ends 116 of the member are preferably shaped with a curvature that matches the curvature of the vial 104. The vial 104 can be made of any convenient material such as glass or clear plastic. The member 112 can be made of any convenient material, such as wood, cork or plastic. The shape and dimensions of the member 112 are preferably arranged so that its central longitudinal axis 114 is in line with a diameter of the vial 104 and the member 112 stays in this position during use of the level vial 100. If the length L of the member 112 is appreciably less than the diameter of the vial 104, the member 112 will float with its central longitudinal axis 114 parallel to the diameter of the vial 104. This embodiment 10OA is illustrated in Figure 3A. While not preferred, useful level vials could be constructed this way. The member 112 can have two scribe marks 120 placed equidistant from its center. When the level vial 100 is positioned vertically, the member 112 floats level no matter how the vial 104 is turned in the vertical plane.

Figure 5 illustrates another alternate embodiment 100B. In this embodiment 100B, the ends 116 of the member are flat but it has slightly broken corners 124 and only one central scribe mark 120. Figure 6 illustrates another embodiment 100C. In this embodiment 100C, the ends of the member are pointed. Figures 7 and 8 illustrate yet another embodiment 100D, in which the member 112 is a bubble level vial with curved ends128. Figures 9 and 10 illustrate still another embodiment 100E in which the member 112 is a standard bubble level vial 132 with low specific gravity projections 136 fastened to each end 140. The ends 144 of the projections 136 may have shapes previously described for the members 112 on Figures 3, 5 and 6.

Figure 10A is a side elevational view showing how the member and vial can be pivotally attached center to center with a pivot pin.

Figures 11 and 12 illustrate one way this invention can be built into a level frame. Such a level 10 has a frame 14 which has a top plane surface 18, a bottom plane surface 22 and an intermediate web 26. The top and bottom plane surfaces 18, 22 are parallel to each other.

Retained within the web 26 is a level vial 100, 100A, 100B, 10OC, 10OD or 100E. A variety of different methods are used to retain the level vial 100A-E within the web 26. Scribed onto the web 26 are one or more horizontal and/or vertical scribe marks 50, 54. The horizontal mark(s) 54 are parallel to the top 18 and bottom 22 surfaces. The vertical mark(s) 50 are at right angles to the top 18 and bottom 22 surfaces. These vertical mark(s) 50 are intended to line up with the scribe mark(s) 120 on the member 112. The horizontal mark(s) are intended to line up with the top 148 and/or bottom 152 surfaces of the member 112. Every dimension of an item must be fabricated to a tolerance. Thus the when the terms right angle, parallel, etc. are used in this specification it will be understood that this means within manufacturing tolerances.

It will be appreciated by those familiar with the art to which this invention pertains how a level 10 constructed with a viaM OO, 100A, 100B, 100C, 100D or 100E in accordance with this invention works. When the level 10 is placed on a horizontal surface, if the horizontal mark(s) 54 line up with the top 148 and bottom 152 surfaces of the member 112, or the vertical mark(s) 50 line up with the scribe mark(s) 120 the surface is level. If the horizontal mark(s) 54 do not line up (i.e. are at an angle to) with the top 148 and bottom 152 surfaces of the member 112, or the vertical mark(s) 50 do not line up with the scribe mark(s) 120 the surface is not level. Figure 11A illustrates how the level 10 looks when it is placed on a not level surface. Further when the level 10 is placed on a vertical surface, if the vertical mark(s) 54 line up with the top 148 and bottom 152 surfaces of the member 112, or the horizontal mark(s) 50 line up with the scribe mark(s) 120 the surface is plumb. If the vertical mark(s) 54 do not line up (i.e. are at an angle to) with the top 148 and bottom 152 surfaces of the member 112, or the horizontal mark(s) 50 do not line up with the scribe mark(s) 120 the surface is not plumb.

While all vials described and illustrated so far in this document have been circular, there is no reason why other shapes such as square, rectangular or oval could not be used. A level incorporating an oval vial is illustrated in Figure 13.

For proper use of levels 10, scribe marks 50, 54, may have to cross the level vial 100A, 100B, 110C, 100D, 100E. Such a construction is illustrated in Figure 14. The web 14, is covered with a clear material 60 which covers the vial 100A, 100B, 110C, 100D, 100E. Then the scribe mark, in this case 54, is inscribed on the clear material 60.

It has been found that air becomes trapped under the straight member 112, when the vial 100A, 100B, 110C, 100D, 10OE is inverted. As illustrated in Figures 15A and 15B, air holes 64 through the straight member 112, will allow the air to flow to the top of the vial again. Alternatively, end vents 68, as illustrated in Figures 16A and 16B will accomplish the same purpose.

The level vial 100, 100A, 100B, 100C, 100D, 100E has been described with reference to several embodiments. However, it should be obvious to those skilled in the art to which this invention pertains that other modifications and enhancements can be made without departing from the spirit and scope of the claims that follow.

Claims

1. A level vial comprising:

a) a cylindrical vial;

b) a fluid within said cylindrical vial; and

c) a straight member within said cylindrical vial; said straight member having a specific gravity less than the specific gravity of said fluid, a length less than the inside diameter of said cylindrical vial, and a thickness less than the inside depth of said cylindrical vial.

2. A level vial as claimed in claim 1 in which the cross section of said straight member is circular.

3. A level vial as claimed in claim 1 in which the cross section of said straight member is square.

4. A level vial as claimed in claim 1 in which the ends of said straight member are curved.

5. A level vial as claimed in claim 1 in which the ends of said straight member are pointed.

6. A level vial as claimed in claim 1 further comprising a transverse scribe mark on said straight member.

7. A level vial as claimed in claim 1 in which the center of said straight member is pivotally attached to the center of said vial.

8. A level vial as claimed in claim 1 in which said straight member comprises a standard bubble level vial having a specific gravity less than the specific gravity of said fluid.

9. A level vial as claimed in claim 1 in which said straight member comprises a standard bubble level vial, with a section of material having a specific gravity less than the specific gravity of said fluid attached to each end.

10. A level vial as claimed in claim 1 in which said straight member includes a vertical through hole.

11.A level vial as claimed in claim 1 in which said cylindrical vial is circular.

12.A level vial as claimed in claim 1 in which said cylindrical vial is rectangular.

13.A level vial as claimed in claim 1 in which said cylindrical vial is oval.

14. A level comprising:

a) a frame having: at least one plane measuring surface and at least one side at right angles to each other; said frame designed to retain a level vial so that said level vial is visible from said side;

b) a level vial as claimed in claim 1 affixed within said frame; and

c) a level indicating mark on said side.

15. A level as claimed in claim 14 further comprising a cladding on said plane measuring surface.

16.A method of fabricating a level vial comprising the steps of:

a) obtaining a cylindrical vial;

b) obtaining a fluid;

c) obtaining a straight member; said straight member having a specific gravity less than the specific gravity of said fluid, a length less than the inside diameter of said cylindrical vial, and a thickness less than the inside depth of said cylindrical vial;

d) placing said straight member within said cylindrical vial; and

e) filling said cylindrical vial with said fluid.

17.A method as claimed in claim 16 in which the cross section of said straight member is circular.

18.A method as claimed in claim 16 in which the cross section of said straight member is square.

19.A method as claimed in claim 16 in which the ends of said straight member are curved.

20. A method as claimed in claim 16 in which the ends of said straight member are pointed.

21.A method as claimed in claim 16 further comprising the step of inscribing a transverse scribe mark on said straight member.

22.A method as claimed in claim 16 further comprising the step of pivotally attaching the center of said straight member to the center of said vial.

23.A method as claimed in claim 16 in which said straight member comprises a standard bubble level vial having a specific gravity less than the specific gravity of said fluid.

24.A method as claimed in claim 16 in which said straight member comprises a standard bubble level vial, with a section of material having a specific gravity less than the specific gravity of said fluid attached to each end.

25.A method as claimed in claim 16 in which said straight member includes a vertical through hole.

26.A method as claimed in claim 16 in which said cylindrical vial is circular.

27.A method as claimed in claim 16 in which said cylindrical vial is rectangular.

28.A method as claimed in claim 16 in which said cylindrical vial is oval.

29.A method of fabricating a level comprising the steps of:

a) fabricating a frame having; at least one plane measuring surface and at least one side at right angles to each other; said frame designed to retain a level vial so that said level vial is visible from said side;

b) obtaining level vial as claimed in claim 16;

c) affixing said level vial within said frame; and

d) applying a level indicating mark to said side.

30. A method as claimed in claim 29 further comprising the step of fastening a cladding to said plane measuring surface.