WO2011070562A1

WO2011070562A1 - Level with asymmetrical transverse cross section

Info

Publication number: WO2011070562A1
Application number: PCT/IL2010/000458
Authority: WO
Inventors: Rafi Ben-Josef; Shahar Harari; Yossi Palatshe; Amy Levinson; Tsvi HERSHKOVICH
Original assignee: Kapro Industries Ltd
Priority date: 2009-12-13
Filing date: 2010-06-09
Publication date: 2011-06-16
Also published as: WO2011070561A1

Abstract

Levels including a main body for assisting a user holding a level in a conventional manner to instinctively tactilely distinguish whether he is holding the level in a front to back orientation, namely, facing its front major surface, or a back to front orientation, namely, facing its rear major surface, and a level indication device for indicating the orientation of the level relative to the horizontal.

Description

LEVEL WITH ASYMMETRICAL TRANSVERSE CROSS SECTION

Field of the Invention

This invention relates to levels.

Background of the Invention

Conventional box section spirit levels include a rectangular box section main body having a longitudinal axis, parallel and opposite front and rear major surfaces, left and right ends, a leveling surface for placing on a surface, and a top surface parallel and opposite the leveling surface. The spirit levels include a horizontal bubble vial for indicating level in a horizontal plane and typically include one or more vertical bubble vials for indicating plumb in a vertical plane. The spirit levels can include one or more handgrips depending on their length, weight, etc. Users typically grip a spirit level with their palms bridging over a spirit level's top surface such that their thumb and fingers are disposed against opposite major surfaces.

Conventional rectangular box section spirit levels are manufactured from a symmetrical extruded rectangular box section aluminum profile. Such profiles are symmetrical with respect to a longitudinal vertical plane perpendicular to a minor surface intended to become a leveling surface for placing on a generally horizontal surface and midway along aforesaid leveling surface in a transverse cross section in a left end elevation view. Such profiles undergo several manufacturing steps after being cut into required metric or inch lengths including inter alia punching of apertures, punching of cutaways, milling of a minor surface to become a leveling surface, milling of a pair of opposite minor surfaces to become a pair of opposite leveling surfaces, painting, etc. Some apertures are intended, for example, for mounting, horizontal bubble vials, vertical bubble vials, handgrips, and the like. Some cutaways are intended for mounting digital units for displaying digital readouts, and the like. One such commercially available digital level is Applicant's

DIGIMAN Professional Digital Box Level, model No. 985D. Most professional users become accustomed to reading a spirit level in a front to back orientation, namely, facing its front major surface, for observing its bubble vials notwithstanding its one or more bubble vials can be equally observed when a user is facing its rear major surface in a back to front orientation of the spirit level. Moreover, many such professional users are even accustomed to flipping a spirit level from a back to front orientation to a front to back orientation to ensure they are facing their preferred front major surface for observing a bubble vial. Professional users when they are not actively using their spirit levels place them close by on one side, on the floor, etc and then "blindly" reach out to grip them when they require them for a particular measurement. However, users cannot instinctively tactilely distinguish the orientation of a conventional box section spirit level and therefore a user may unknowingly grip a spirit level in a back to front orientation. Only on placing the spirit level in front of himself or observing the spirit level would the user realize the back to front orientation whereupon he has to awkwardly flip it to his preferred front to back orientation. Thus, the force of habit of professional users who prefer to take measurements in a front to back orientation of a spirit level often impedes them during their work Summary of the Invention

The present invention is directed towards levels including a main body for assisting a user holding a level in a conventional manner along its entire length to instinctively tactilely distinguish whether he is holding the level in a front to back orientation, namely, facing its front major surface, or a back to front orientation, namely, facing its rear major surface, and a level indication device for indicating the orientation of the level relative to the horizontal. The present invention is achieved by manufacturing the levels from asymmetrical closed hollow transverse cross section profiles as opposed to aforesaid symmetrical rectangular box section profiles. The asymmetrical closed hollow cross section profiles undergo some or all of aforesaid manufacturing steps in a conventional manner. The present invention is envisaged to assist professional users to work more efficiently by ensuring that they will always be able to immediately tactilely distinguish the orientation of a level along its entire length and therefore correctly place a level in front of them in their preferred front to back orientation.

It should be noted that users gripping, for example, Applicant's

®

DIGIMAN Professional Digital Box Level, model No. 985D at its digital unit can instinctively tactilely distinguish whether they have gripped the level in a front to back orientation or a back to front orientation. However, this cross section is an asymmetrical open hollow transverse cross section due to the presence of the punched cutout for the digital unit as opposed to an asymmetrical closed hollow transverse cross section in accordance with the

®

present invention. Users gripping the Applicant's DIGIMAN Professional Digital Box Level, model No. 985 D at locations other than its at digital unit are unable to tactilely distinguish whether they have gripped the level in a front to back orientation or a back to front orientation.

The levels of the present invention can be provisioned with a conventional horizontal bubble vial level and/or a conventional digital unit both constituting aforesaid level indication device. The horizontal bubble vials can be constituted by inter alia cylindrical bubble vials, rectangular parallelepiped bubble vials, and the like. The levels can be provisioned with one or more handgrips depending on their length, weight, etc. The leveling surface can be flat or grooved in aforesaid transverse cross section. Grooved leveling surfaces are suitable for placing on pipes, etc. The levels can be provisioned with one or more magnets for hands free mounting on magnetic surfaces.

The levels of the present invention can be provisioned with a horizontal bubble vial observable between a top plan view and a front elevation view only and unobservable from a rear elevation view. The levels can be provisioned with a horizontal bubble vial including a coloring agent as illustrated and described in Applicant's PCT International Application No. PCT/IL2009/001184 entitled Spirit Level having Horizontal Bubble Vial with Improved Bubble Visibility, the contents of which are incorporated by reference.

Brief Description of Drawings

In order to understand the invention and to see how it can be carried out in practice, preferred embodiments will now be described, by way of non- limiting examples only, with reference to the accompanying drawings in which similar parts are likewise numbered, and in which:

Fig. 1 is a front perspective view of a conventional box section spirit level with a rectangular box section main body including a horizontal bubble vial, a vertical bubble vial, a handgrip, and a digital unit for displaying digital readouts;

Fig. 2 is a transverse cross section along line A-A in Figure 1 in a left end elevation view showing a symmetrical closed rectangular box section;

Fig. 3 is a transverse cross section along line B-B in Figure 1 in a left end elevation view showing a symmetrical open hollow transverse cross section at the horizontal bubble vial;

Fig. 4 is a transverse cross section along line C-C in Figure 1 in a left end elevation view showing a symmetrical open hollow transverse cross section at the vertical bubble vial;

Fig. 5 is a transverse cross section along line D-D in Figure 1 in a left end elevation view showing a symmetrical open hollow transverse cross section at the handgrip;

Fig. 6 is a transverse cross section along line E-E in Figure 1 in a left end elevation view showing an asymmetrical open hollow transverse cross section at the digital unit;

Fig. 7 is a front perspective view showing a spirit level including a horizontal bubble vial, a vertical bubble vial and a handgrip in accordance with the present invention; Fig. 8 is a transverse cross section along line F-F in Figure 7 in a left end elevation view showing an asymmetrical closed hollow transverse cross section;

Fig. 9 is a transverse cross section along line G-G in Figure 7 in a left end elevation view showing an asymmetrical open hollow transverse cross section at the horizontal bubble vial;

Fig. 10 is a transverse cross section along line H-H in Figure 7 in a left end elevation view showing an asymmetrical open hollow transverse cross section at the vertical bubble vial;

Fig. 11 is a transverse cross section along line I-I in Figure 7 in a left end elevation view showing an asymmetrical open hollow transverse cross section at the handgrip;

Fig. 12 is a front perspective view of a user's right hand gripping Figure 7's spirit level in a preferred front to back orientation;

Fig. 13 is a front perspective view of a user's right hand gripping Figure

7's spirit level in an undesired back to front orientation;

Fig. 14 is a transverse cross section of an extruded hollow main body profile with an alternative asymmetrical closed hollow transverse cross section;

Fig. 15 is a transverse cross section of an extruded hollow main body profile with an another alternative asymmetrical closed hollow transverse cross section;

Fig. 16 is a transverse cross section of an extruded hollow main body profile with a yet another alternative asymmetrical closed hollow transverse cross section; and

Fig. 17 is a transverse cross section of an extruded hollow main body profile with a yet another alternative asymmetrical closed hollow transverse cross section.

Detailed Description of Preferred Embodiments of the Invention

Symmetrical Closed Hollow Transverse Cross Section Spirit Levels Figures 1 to 6 show a spirit level 10 including an extruded rectangular box section main body 11 having a longitudinal axis 12, a front major surface 13, a rear major surface 14, a left end 16, a right end 17, a leveling surface 18 for placing on a surface, and a top surface 19 parallel and opposite the leveling surface 18. The front and rear major surfaces 13 and 14 are parallel and opposite and co-directional with the longitudinal axis 12. The leveling surface 18 extends widthwise between the front and rear major surfaces 13 and 14. The leveling surface 18 and the top surface 19 have the same width W. The leveling surface 18 joins the front and rear major surfaces 13 and 14 at longitudinal edges 21 A and 21B. The top surface 19 joins the front and rear major surfaces 13 and 14 at longitudinal edges 21C and 21D.

The spirit level 10 includes a lengthwise directed central horizontal bubble vial 22 having a longitudinal axis parallel to the leveling surface 18 for providing a visual indication of the inclination of a generally horizontal surface relative to the horizontal, and a vertical bubble vial 23 having a longitudinal axis perpendicular to the leveling surface 18 towards the right end 16 for providing a visual indication of the inclination of a generally vertical surface relative to the vertical. The spirit level 10 includes a handgrip 24 and a digital unit 26 for displaying digital readouts.

The main body 11 has a symmetrical closed hollow rectangular box section along line A-A with respect to a lengthwise directed vertical plane VP perpendicular to the leveling surface 18 and midway along its width, namely, at a distance W/2 from the rear major surface 12. The main body 11 has symmetrical open hollow transverse cross sections along line B-B at the horizontal bubble vial 22, line C-C at the vertical bubble vial 23 and line D-D at the handgrip 24. The main body 11 has an asymmetrical open hollow transverse cross section along line E-E at the digital unit 26.

Users gripping the spirit level 10, for example, towards the right end 17 are unable to tactilely distinguish whether they have gripped in the spirit level 10 in a front to back orientation, namely, facing the front major surface 13 or a back to front orientation, namely, facing, the rear major surface 14. In the front to back orientation, the users tactile distinguish the longitudinal edge 21C close to their thumbs and the longitudinal edge 21 D close to their fingers. In the back to front orientation, the longitudinal edge 21D close to their thumbs and the longitudinal edge 21C close to their fingers.

Asymmetrical Closed Hollow Transverse Cross Section Spirit Levels Figures 7 to 13 show a spirit level 40 having a similar construction as the spirit level 10 with similar parts similar numbered. The former 40 differs from the latter 10 by virtue of being manufactured from an extruded closed hollow transverse cross section profile to assist a user to instinctively tactilely distinguish whether he has gripped the spirit level 40 in a preferred front to back orientation (see Figure 12) or an undesired back to front orientation (see Figure 13).

The spirit level 40 includes a near rectangular box section main body 41 having a longitudinal axis 42, a front major surface 43, a rear major surface 44, a left end 46, a right end 47, a leveling surface 48 for placing on a surface, and a top surface 49 parallel and opposite the leveling surface 48. The main body 41 has a height HI. The leveling surface 48 has a width Wl.

The front major surface 43 includes a lower front surface 51 perpendicular to the leveling surface 48 and a curved upper transition surface 52 joining the top surface 49 and the lower front surface 51. The lower front surface 51 has a height H2 where 0.75H1 > H2 > 0.5 HI. The top surface 49 has a width W2 where 0.6 Wl > W2 > 0.4W1.

The main body 41 has an asymmetrical closed hollow transverse cross section along line F-F with respect to a lengthwise directed vertical plane VP perpendicular to the leveling surface 48 and midway along its width, namely, at a distance W/2 from the rear major surface 44. The main body 41 has asymmetrical open hollow transverse cross sections along line G-G at the horizontal bubble vial 22, line H-H at the vertical bubble vial 23 and line I-I at the handgrip 24. Users gripping the spirit level 40, for example, towards the right end 47 is able to instinctively tactilely distinguish whether they have gripped in the spirit level 40 in a front to back orientation, namely, facing the front major surface 43 or a back to front orientation, namely, facing the rear major surface 44. In the front to back orientation, the users tactile distinguish the upper transition surface 52 close to their thumbs and the rear major surface 44 close to their fingers. In the back to front orientation, the users tactile distinguish the rear major surface 44 close to their thumbs and the upper transition surface 52 close to their fingers.

The spirit level 40 includes a cutaway 61 for receiving the horizontal bubble vial 22 constituted by a rectangular parallelepiped bubble vial 62 disposed in and mounted at 45° with respect to a conventional mounting as shown in Figures 1 and 3. A lengthwise vertical plane PI and a horizontal plane P2 intersect at the center of the bubble vial 62 and divide same into a front upper quadrant FUQ, a rear upper quadrant RUQ, a front lower quadrant FLQ, and a rear lower quadrant RLQ. The vertical plane PI and the vertical plane VP may or may not coincide depending on the leveling surface 48's width and the location of the bubble vial 62 within the spirit level 40. The bubble vial 62 includes an external peripheral surface 63 divided into a front upper bubble vial surface 63A in the front upper quadrant FUQ, a rear upper bubble vial surface 63B in the rear upper quadrant RUQ, a front lower bubble vial surface 63C in the front lower quadrant FLQ and a rear lower bubble vial surface 63 D in the rear lower quadrant RLQ.

The bubble vial 62 has a longitudinal barrel shaped bubble cavity 64 having an internal cavity surface 66 including an uppermost internal cavity surface 66A towards the top surface 49. The bubble cavity 64 includes a central portion 67 with a pair of spaced apart reference lines 68. The bubble cavity 64 is near completely filled with a vial liquid 69 leaving a lengthwise directed ellipsoidal bubble 71 with a central meniscus surface 72 and an uppermost bubble surface 73 bounded by the uppermost internal cavity surface 66A. The spirit level 40 also includes a transparent window 74 and a lengthwise directed transparent or opaque colored uniform triangular prism 76 constituting a coloring agent disposed against the rear upper bubble vial surface 63B for coloring the bubble's uppermost bubble surface 73 along a user's direct line of sight LOS bounded between a direct top plan view TPV and a direct front elevation view FEV in the front upper quadrant FUQ.

The spirit level 40 also includes an additional lengthwise directed transparent or opaque colored uniform triangular prism 77 constituting a second coloring agent disposed against the front lower bubble vial surface 63C for coloring the central meniscus surface 69 as perceived by a user observing the bubble 71 along the direct line of sight LOS. The spirit level 40 also includes a typically white opaque uniform triangular prism 78 disposed against the rear lower bubble vial surface 63 D for providing a bright background for further accentuating the central meniscus surface 72 and the bubble surface 73 as perceived by a user.

Figures 14 to 17 show alternative asymmetrical closed hollow transverse cross sections along Figure 7's line F-F. Figure 14 shows an asymmetrical closed hollow transverse cross section similar to Figure 8's asymmetrical closed hollow transverse cross section but having a planar upper transition surface 52. Figure 15 shows an asymmetrical closed hollow transverse cross section similar to Figure 8's asymmetrical closed hollow transverse cross section but having a grooved leveling surface 48 and a curved top surface 49 joining the rear major surface 44 and a curved front major surface 43. Figure 16 shows an asymmetrical closed hollow transverse cross section similar to Figure 2's symmetrical closed hollow transverse cross section and additionally including a longitudinal directed front flange 53. Figure 17 shows an asymmetrical closed hollow transverse cross section similar to Figure 2's symmetrical closed hollow transverse cross section except that its front major surface 43 includes a longitudinal directed recess 54.

While the invention has been described with respect to a limited number of embodiments, it will be appreciated that many variations, modifications, and other applications of the invention can be made within the scope of the appended claims.

Claims

CLAIMS:

1. A level for placing on a generally horizontal surface, the level comprising:

(a) an extruded hollow main body having a longitudinal axis, a front major surface, a rear major surface, a leveling surface for placing on the generally horizontal surface, and a top surface opposite said leveling surface,

said front major surface and said rear major surface being co -directional with said longitudinal axis; and

(b) a level indication device for indicating the orientation of the level relative to the horizontal,

characterized in

said extruded hollow main body having at at least one location along the level an asymmetrical closed hollow transverse cross section with reference to a longitudinal vertical plane perpendicular to said leveling surface and midway along said leveling surface in a transverse cross section in a left end elevation view whereupon a user gripping said main body with his palm extending widthwise over said top surface such that his thumb and fingers are disposed against said front major surface and said rear major surface at a location of said at least one location is capable of instinctively tactilely distinguishing a front to back orientation of the level from a back to front orientation.

2. The level according to claim 1 wherein said front major surface includes a longitudinal directed lower front surface substantially perpendicular to said leveling surface and an upper transition surface joining said top surface wherein said main body has a height HI and said lower front surface has a height H2 where 0.75H1 > H2 > 0.5 HI in said left end elevation view.

3. The level according to claim 2 wherein said leveling surface has a width Wl and said top surface is parallel to said leveling surface and has a width W2 where 0.6W1 > W2 > 0.4W1 in said left end elevation view.

4. The level according to claim 2 wherein said top surface is parallel to said leveling surface and has a width W2 where 0.6W1 > W2 > 0.4W1 in said left end elevation view.

5. The level according to claim 2 wherein said upper transition surface is planar in a transverse cross section of said main body in said left end elevation view.

6. The level according to claim 2 wherein said upper transition surface is curved in a transverse cross section of said main body in said left end elevation view.

7. The level according to claim 1 wherein said top surface and said front major surface are curved in a transverse cross section of said main body in said left end elevation view.

8. The level according to any one of claims 1 to 7 wherein said level indication device is constituted by a digital unit for displaying digital readouts of the inclination of a surface relative to the horizontal.

9. The level according to any one of claims 1 to 7 wherein said level indication device is constituted by a bubble vial for indicating the inclination of a surface relative to the horizontal.

10. The level according to claim 9 wherein said bubble vial includes a bubble cavity with a central region and an internal uppermost cavity surface towards said top surface and an external peripheral surface, said bubble cavity near completely filled with a vial liquid having a central meniscus surface to leave a lengthwise directed ellipsoidal bubble with an uppermost bubble surface uppermost bounded by said internal uppermost cavity surface, a pair of orthogonal planes including a lengthwise directed vertical plane perpendicular to said leveling surface and traversing said bubble cavity at said central region and a horizontal plane parallel to said leveling surface and traversing said bubble cavity at said central region for dividing said external peripheral surface into a front upper bubble vial surface in a front upper quadrant, a rear upper bubble vial surface in a rear upper quadrant, a front lower bubble vial surface in a front lower quadrant, and a rear lower bubble vial surface in a rear lower quadrant,

said level further comprising a coloring agent in said rear upper quadrant such that a user observing said bubble vial along a line of sight bounded within said front upper quadrant perceives said uppermost bubble surface as being colored thereby improving bubble visibility for assisting user readability for leveling purposes.

11. The level according to claim 10 and further comprising a lengthwise directed bright opaque background surface in said rear lower quadrant such that a user observing said bubble vial along a line of sight bounded within said front upper quadrant perceives said colored bubble surface against said bright opaque background thereby further improving bubble visibility for assisting user readability for leveling purposes.

12. The level according to claim 10 and further comprising an additional coloring agent disposed in said front lower quadrant such that a user observing said bubble vial along a line of sight bounded within said front upper quadrant perceives said central meniscus surface as being colored in addition to said colored bubble surface thereby further improving bubble visibility for assisting user readability for leveling purposes.