Adjustable T-square

1. An adjustable T-square comprising:

a head portion with a body adapted to sit adjacent to a work surface;

a ruler portion movable relative to the head portion, wherein the ruler portion has a first portion and a second portion, and the first portion defines a plurality of angle apertures therein;

a locking mechanism operative to lock the ruler portion in a fixed position relative to the head portion; and

an alignment mechanism including at least one locking detent having a detent body operatively engaged with a spring; and

wherein an aperture of the plurality of angle apertures is operative to accept the at least one locking detent when at least a portion of the detent body is received within the aperture and the spring is in an extended position.

2. The adjustable T-square of claim 1 , further comprising:

a pivot pin extending between the ruler portion and the head portion, said pivot pin enabling pivotal motion of the ruler portion relative to the head portion when the locking mechanism is disengaged.

3. The adjustable T-square of claim 2 wherein the locking mechanism further comprises:

at least one locking pin.

4. The adjustable T-square of claim 3 , wherein the at least one locking pin and pivot pin are operative to prevent movement of the ruler portion with respect to the head portion.

5. The adjustable T-square of claim 1 , further comprising:

a faceplate that extends partially over a first end of the ruler portion and is operatively connected to the head portion.

6. The adjustable T-square of claim 5 , further comprising:

a channel formed by the faceplate and a top surface of the head portion operative to permit movement of the ruler portion within the channel.

7. The adjustable T-square of claim 1 , wherein the

first portion of the ruler portion has an arced surface and wherein the plurality of angle apertures are defined in the arced surface and extend between an inner surface and an outer surface of the arced surface.

8. The adjustable T-square of claim 7 , wherein the first portion further includes a track operative to accept a portion of a locking pin of the locking mechanism therein.

9. The adjustable T-square of claim 1 , wherein the head portion further comprises:

a plurality of indicia indicating angle of the ruler portion with respect to the head portion.

10. The adjustable T-square of claim 1 , wherein the alignment mechanism includes:

audible and tactile feedback members to operative to provide audible and tactile feedback to a user that the apparatus is set to a precise angle.

11. A method for drawing a straight angled line comprising:

rotating a ruler portion of an adjustable T-square;

aligning an alignment mechanism of the adjustable T-square with angled indicia on a head portion of the adjustable T-square;

engaging a locking mechanism of the adjustable T-square at a precise angle to prevent movement of the ruler portion with respect to the head portion;

using an edge of the ruler portion to draw a line with a writing implement at the precise angle; and

wherein during rotating:

hearing audible feedback from the alignment mechanism which is operative to provide audible feedback to a user; and

feeling tactile feedback from the alignment mechanism which is operative to provide tactile feedback to the user, wherein the audible feedback and the tactile feedback indicate to the user that the precise angle is engaged.

12. The method of claim 11 , further comprising:

prior to rotating;

disengaging a locking mechanism that allows the ruler potion to rotate with respect to the head portion.

13. The method of claim 11 , wherein aligning further comprises:

interlocking at least one locking detent into an aperture on the ruler portion.

14. The method of claim 11 , where rotating comprises:

rotating the ruler portion about a pivot point engaged with the ruler portion and the head portion.

15. The method of claim 11 , wherein prior to rotating:

abutting the head portion against a work surface.

16. An adjustable T-square comprising:

a head portion including a first surface and a second surface, wherein the first surface is adapted to rest adjacent an edge of a work piece, and the second surface is arranged at right angles to the first surface;

a recess defined in the second surface of the head portion, wherein the recess originates in the first surface and extends inwardly into the head portion and away from the first surface, and wherein the recess includes an arcuate section;

angle indicia provided on the second surface of the head portion in the arcuate section of the recess;

a ruler portion comprising a first portion and a second portion;

wherein the first portion is received within the arcuate section of the recess of the head portion;

wherein the second portion extends outwardly from the first portion and beyond the first surface of the head portion;

a pivot pin extending between the ruler portion and the head portion, said pivot pin enabling pivotal motion of the ruler portion relative to the head portion; and

a locking mechanism extending between the ruler portion and the head portion a distance away from the pivot pin, said locking mechanism being movable between an engaged position and a disengaged position, and when the locking mechanism is in the engaged position, pivotal motion of the ruler portion relative to the head portion is prevented.

17. The adjustable T-square of claim 16 , wherein the second portion of the ruler portion extends outwardly in a first direction from a straight edge of the first portion, wherein side edges of the second portion extend outwardly at right angles to the straight edge of the first portion; and wherein a section of the straight edge of the first portion of the ruler portion is selectively alignable with one of the angle indicia of the head portion.

18. The adjustable T-square of claim 17 , wherein the first portion further includes an arcuate edge that curves convexly through 180° from a first end of the straight edge of the first portion to a second end of the straight edge of the first portion, and wherein the arcuate edge of the first portion of the ruler portion is complementary to the arcuate section of the recess of the head portion.

19. The adjustable T-square of claim 18 , wherein the head portion includes a faceplate that overhangs the arcuate edge of the ruler portion.

20. The adjustable T-square of claim 16 , further comprising

an adjustment mechanism that provides both tactile and audible feedback when the ruler portion is pivoted relative to the head portion.