Swinging t-square

Claim 2

A swinging T-square tool comprising an upstanding T-square having a planar rear wall surface, a semicircular head, a blade Depending from the midsection of said head and a cylindrical boss projecting forwardly about the transverse center of volume of said T-square at the juncture of said head with said blade, panel means disposed in spatially adjacent parallelism with the rear wall surface of the T-square, a stub shaft rigidly secured to said panel means and projecting therefrom concentrically through said cylindrical boss, bearing means normally pendulously supporting said T-square on said shaft, and stop means rectilinearly movable along the shaft and engagable with the interior of said boss for releasably locking said T-square to said panel means.

Claim 3

The tool in accordance with claim 1, wherein the semicircular arc of the T-square head is subdivided as a protractor.

Claim 4

The T-square tool defined in claim 1, wherein an internal recess tapers inwardly from the forward end of said boss and said stop means has an externally tapered portion conforming to the internal surface of said recess, said stop means being reciprocably movable to either fit snugly into said recess or move therefrom.

Claim 5

The subject matter of claim 3, in which a guide slot extends longitudinally along the stub shaft and said stopper includes an inwardly projecting portion fitting into the guide slot.

Claim 6

The subject matter of claim 3, wherein a plurality of longitudinally extending microgrooves constitute the external surface of the tapered portion of said stopper.

Claim 7

The subject matter of claim 3, wherein a plurality of microgrooves extend longitudinally over the internal surface of said recess.

Claim 8

The swinging T-square tool in accordance with claim 3, including resilient means opposing movement of said stopper in the direction to enter said recess.

Claim 9

The tool in accordance with claim 1, in which said bearing means is a ball bearing structure interposed between said shaft and said boss.

Claim 10

A swinging T-square tool for use in an upright position, comprising inflexible upper and lower rectangular panels of equal width, a stub shaft rigidly secured to and projecting normally forward through the vertical centerline of the lower panel, bearing means revolubly supporting a T-square on said shaft and stop means rectilinearly movable along said shaft, said stop means coacting with said shaft to lock said T-square to said shaft, and T-square having a semicircular head through which said shaft extends, a blade depending from the midsection of said head and a planar rear wall surface disposed in spatially adjacent parallelism with the forward wall surface of the lower panel, said upper panel being hinged to the upper margin of the lower panel and swingable downwardly and outwardly between a position coplanar with the forward face of the lower panel and a position perpendicular thereto, and limit stops mounted on said lower panel in the path of movement of said upper panel, said stops limiting the upward and inward swingable movement of said upper panel to said coplanar position.

Claim 11

A swinging T-square tool for use in an upright position, comprising inflexible upper and lower rectangular panels of equal width, a stub shaft rigidly secured to and projecting normally forward through the vertical centerline of the lower panel, bearing means revolubly supporting a T-square on said shaft and stop means rectilinearly movable along said shaft, said stop means coacting with said shaft to lock said T-square to said shaft, and T-square having a semicircular head through which said shaft extends, a blade depending from the midsection of said head and a planar rear wall surface disposed in spatially adjacent parallelism with the forward wall surface of the lower panel, said upper panel being hinged to the upper margin of the lower panel and swingable downwardly and outwardly between a position coplanar with the forward face of the lower panel and a position perpendicular thereto, and limit stops mounted on said lower panel in the path of movement of said upper panel, said stops limiting the upward and inward swingable movement of said upper panel to said coplanar position.

Claim 12

The subject matter of claim 9, wherein fastening means for tacking the tool to an associated structural member is secured to the upper margin of the upper panel.

Claim 13

The subject matter of claim 9, in which a bracket secured midway on the upper margin of the upper panel projects forwardly therefrom.

Claim 14

The tool as set forth in claim 9, wherein the semicircular head of the T-square bears indicia means for indicating the angle of departure from the horizontal of the lower edge of said lower rectangular panel.