Spirit level

Wider overall angular viewing range for a spirit level achieved by provisioning spirit levels with a bubble vial module including a reflective surface wherein the reflective surface is manually pivotal about a pivot axis relative to a non-pivoted direct opposite viewing position such that a user can pivot the reflective surface towards himself. The system may include predetermined viewing positions.

FIELD OF THE INVENTION

This present invention relates to spirit levels in general and to spirit levels for setting a vertical surface in particular.

BACKGROUND OF THE INVENTION

U.S. Pat. No. 2,791,036 to Gericke entitled Liquid Level discloses a spirit level10having a leveling surface11for placing on a surface to be leveled, a top surface opposite the leveling surface, and a pair of opposite major surfaces extending between the leveling surface and the top surface. The spirit level10is provided with a liquid level tube21having right angularly extending portions22and23is formed with level indicating lines24and filled with a liquid25(see US '036 Col. 2, lines 13-15). Air forming a bubble27is trapped in the tube21and is adapted to cooperate with the indicator lines24in either arm22or23depending on the position of the level10(see US '036 Col. 2, lines 17-20). The spirit level10is provided with a retainer plate38which is highly polished and serves as a mirror to reflect an image of the arm22of the tube21as illustrated inFIG. 1to permit the horizontal bubble vial therein to be viewed from eye level (see US '036 Col. 2, lines 39-42). A user can view the reflected image of the vial along a so-called direct opposite line of sight directly opposite the spirit level and within a limited so-called direct opposite angular viewing range in the order of ±5° with respect thereto. Any greater movement to the right or left prevents the user viewing the reflected image which limits his ability to work efficiently and comfortably.

Commonly owned U.S. Pat. No. 6,748,666 to Zugel et al. entitled Spirit Level discloses a spirit level10having a body12with a level face14for setting a surface to be leveled, a top surface opposite the leveling surface, and a pair of opposite major surfaces extending between the leveling surface and the top surface. The spirit level10includes one or more bubble vials20mounted in body12for setting a vertical surface and a bubble vial22for setting a horizontal surface. The spirit level10includes a reflective surface36mounted inside a hollow portion of body12at an angle to bubble vial20and to a viewing plane32which reflects the image of bubble vial20to the viewing plane. Reflective surface36can be a polished mirror or a prism. The spirit level also has a limited direct opposite angular viewing range in the order of ±5° with respect a direct opposite line of sight similar to Gericke.

Level which is a continuation of aforementioned U.S. Pat. No. 6,748,666 discloses spirit levels with arrangements for deploying a reflective surface external to a main body for reflecting an image of a vial for setting a vertical surface. However, such arrangements are vulnerable and can only be used from a single side of a spirit level.

There is a need for an improved spirit level so that a user can view a vial for setting a vertical surface over a wider viewing angle compared to the hitherto described spirit levels.

SUMMARY OF THE INVENTION

The present invention is directed towards spirit levels in general and for setting a vertical surface in particular. The spirit levels of the present invention are similar in construction and use as the hitherto described conventional spirit levels insofar as they include an inclined reflective surface for enabling a user standing directly opposite a spirit level to view a reflected image of a bubble vial providing a visual indication of an inclination of a vertical surface to the vertical within a direct opposite angular viewing angle in the order of ±5° with respect a direct opposite line of sight directly opposite the bubble vial.

The spirit levels of the present invention differ from the hitherto described conventional spirit levels insofar as they enable a user standing offset either to the left or the right of a spirit level to still view the reflected image of the bubble vial, thereby enabling a user to use a spirit level work in locations precluding he stand directly opposite a spirit level. Thus, the spirit levels of the present invention afford a wider overall angular viewing range in comparison to the hitherto described conventional spirit levels. This wider overall angular viewing range is achieved by provisioning spirit levels of the present invention with a bubble vial module including a reflective surface wherein the reflective surface is manually pivotal about a pivot axis relative to a non-pivoted direct opposite viewing position such that a user can pivot the reflective surface towards himself.

The reflective surface is preferably pivotal in the order of ±35° with respect to its non-pivoted direct opposite viewing position between an extreme clockwise viewing position and an extreme counterclockwise viewing position such that the spirit level affords an overall angular viewing range in the order of ±40° with respect to a direct opposite line of sight. The reflective surface can be interference fit mounted such that it can be manually pivoted to any angle between its extreme opposite clockwise and counterclockwise positions. Alternatively, the reflective surface can be so-called clicked into one of a predetermined number of viewing positions, for example, a non-pivoted direct opposite viewing position, three clockwise pivoted viewing positions and three counterclockwise pivoted viewing positions. The reflective surface can optionally be a magnifying reflective surface for magnifying the reflected image of a bubble vial.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1is a partial vertical cross section of Gericke's liquid level corresponding to U.S. Pat. No. 2,791,036 FIG. 2 as hereinabove discussed in the Background of the Invention.

FIG. 2is a perspective view of Zugel's spirit level corresponding to U.S. Pat. No. 6,748,666 FIG. 1 as hereinabove discussed in the Background of the Invention.

FIGS. 3 to 12show a spirit level10including a main body11having a longitudinal level axis12, a leveling surface13for setting a vertical surface, a top surface14opposite the leveling surface13, a pair of opposite major surfaces16and17, and a pair of end caps18and19. The main body11defines an imaginary longitudinal plane21traversing the longitudinal level axis12and perpendicular to the leveling surface13.

The main body11is formed with a generally elongated U-shaped cutout22in the top surface14towards the end cap18for forming a first cutout surface23parallel to the leveling surface13, a second cutout surface24perpendicular to the leveling surface13and towards the end cap18and a third curved cutout surface26opposite the second cutout surface24.

The spirit level10is provided with a bubble vial27having a longitudinal bubble vial axis28parallel to the leveling surface13for providing a visual indication regarding the inclination of a horizontal surface relative to the horizontal on setting the leveling surface13on a horizontal surface.

The spirit level10is provided with a bubble vial module29mounted in the cutout22. The bubble vial module29includes a housing31having a bubble vial32having a longitudinal bubble vial axis33disposed in the imaginary longitudinal plane21for providing a visual indication regarding the inclination of a vertical surface relative to the vertical on setting the leveling surface13on a vertical surface.

The housing31includes a support34for supporting a reflective surface member36including a reflective surface37inclined towards the bubble vial32. The support34supports the reflective surface member36about a pivot axis38disposed in the imaginary longitudinal plane21and subtending an acute included angle with the longitudinal bubble vial axis33. The acute included angle is typically in the order of 45°.

FIGS. 3 to 5show a non-pivoted direct opposite viewing position similar to the hitherto described conventional spirit levels. The reflective surface member36is typically pivotal in the order of ±35° with respect to its non-pivoted direct opposite viewing position in a front elevation view of the spirit level10.FIG. 7Ashows an extreme counterclockwise viewing position.FIG. 7Bshows an extreme clockwise viewing position.

The support34has a spring leaf member39for click fitting in longitudinal grooves41formed in the rear of the reflective surface member36such that the reflective surface member36can be manually deployed at any one of a series of, say, seven predetermined viewing positions including the non-pivoted direct opposite viewing position,FIG. 7A's extreme counterclockwise viewing position, andFIG. 7B's extreme clockwise viewing position. The series of predetermined viewing positions includes two additional counterclockwise viewing positions betweenFIG. 3's non-pivoted viewing position andFIG. 7A's extreme counterclockwise viewing position and two additional clockwise viewing positions betweenFIG. 3's non-pivoted viewing position andFIG. 7B's extreme clockwise viewing position.

FIGS. 8 to 10show the use of the spirit level10for determining the inclination of an upright surface as benefited.

FIGS. 8A and 8Bshow the user standing directly opposite the spirit level10and holding the spirit level10in his right hand. The user typically sets the reflective surface37in its non-pivoted viewing position such that the user is able to view a reflected image of the bubble vial27along a direct opposite line of sight bound within a direct opposite angular viewing range similar to the hitherto described conventional spirit levels. The direct opposite angular viewing range is typically in the order of ±5° relative to the imaginary longitudinal plane21.

FIGS. 9A and 9Bshow the user standing to the left of the spirit level10at a −35° line of sight position with respect to the imaginary longitudinal plane21and also holding the spirit level10in his right hand.FIGS. 9A and 9Bshow the reflective surface member37set to its extreme clockwise viewing position for enabling the user to view a reflected image of the bubble vial32from his −35° line of sight position within an ±5° angular viewing range.

FIGS. 10A and 10Bshow the user standing to the right of the spirit level10at a 35° line of sight position with respect to the imaginary longitudinal plane21and holding the spirit level10in his left hand.FIGS. 10A and 10Bshow the reflective surface member37set to its extreme counterclockwise viewing position for enabling the user to view a reflected image of the bubble vial32from his 35° line of sight position within an ±5° angular viewing range.

Thus, the spirit level10affords an overall angular viewing range relative to the imaginary longitudinal plane21in the order of ±40° as opposed to the ±5° direct opposite angular viewing range of the non-pivoted viewing position similar to hitherto described conventional spirit levels.

FIG. 11shows a spirit level50similar to the spirit level10except without the former40is shorter and does not include the bubble vial27.

FIG. 12shows a spirit level60similar to the spirit level10except with the reflective surface is a magnifying reflective surface61for magnifying the reflected image of the bubble vial.

While particular embodiments of the present invention are illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention.