Measuring instrument

The disclosed measuring instrument includes a pair of members arranged together to form a right-angled L and the members having indicia providing linear scales useful in measuring areas in architectural plans and the like. The members are separable at the joint that forms the corner of the L and are further capable of re-connection to each other in end-to-end relationship so as to provide an elongated straight edge. The junction of the members at the corner of the L includes a pivot about which one member may be moved through a 180.degree. range to form an inverted L. In a modification, at least one of the members includes a wing element along one edge and rockable about a separable pivot on an axis parallel to that one edge.

BACKGROUND AND SUMMARY OF THE INVENTION 
The art is replete with various types of measuring devices, such as 
carpenter squares, retractable scaled measuring tapes, bevel squares and 
the like, but none of these enables the speedy accomplishment of measuring 
"to-scale" plans for quantity survey, lay-out, estimating and like 
purposes other than the retractable scaled measuring tape. The carpenter 
square is a fixed L-shaped member, and its versatility is limited. The 
bevel square lacks a precise means for setting the blades at right angles 
to each other. The retractable scaled measuring tape is limited to only 
two scales, usually 1/4"=1'-0" and 150"=1'-0" and only one directional 
measure, vertical and/or or horizontal can be achieved in a given motion. 
Like the tape, the architect's scale is mono-directional and is difficult 
to measure with quickly for quantity take-off purposes even in that 
configuration, mainly because it holds two scales on each face (i.e., from 
left to right and right to left) which overlap one another thus making 
quick measurement confusing and awkward. 
The present invention provides a simple, convenient instrument operable in 
one or more mode(s). A pair of members interconnected to form a 
right-angled L allows for dual scale measure in a single motion, both 
vertically and horizontally and also allows for both scales to be readily 
used, one on the obverse and one on the reverse. The interconnection 
includes a pivot about which the members may be rotated to form an 
inverted L, again allowing for two scales to be readily used, one on the 
obverse and one on the reverse. Thus, in all, in both the "L" and inverted 
"L" position(s) a total of four scales can be applied in the basic and/or 
modified design. The pivot is separable to enable the members to be 
interconnected in end-to-end fashion for achieving an elongated straight 
edge, which is supplemental to the main purpose of the invention which is 
dual directional scale measure in one motion. Numerated indicia are 
provided running in opposing direction to the primary indicia on the scale 
face accordingly on the appropriate scale face to allow for extended, 
elongated measure when in the elongated mode. Further features include the 
provision on the members of indicia representing linear scales of 
different amplitude; e.g., 1/4"= 1'-0", 1/8"=1'-0", 1/2"=1'-0", 3/4"=1'-0" 
and so forth. In a modified form, at least one edge of one member has an 
interchangeable longitudinal "wing" with two scale faces, one on the 
obverse and one on the reverse. This wing pivots about the member which 
allows for flush contact with the measured surface as well as 
interchangeability for use of other scales since it is removable. 
Further salient features of the invention will appear as the disclosure 
progresses in connection with a preferred embodiment of the invention.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION 
Reference will be had first to FIGS. 1 and 2 for a general description of 
what is involved. As seen in these Figures, the measuring instrument 
comprises, essentially, a pair of substantially similar members 10 and 12, 
each being on the order of, say, ten to twelve inches long and one to one 
and one-half inches wide and one-eight to one-quarter inch thick. These 
are, of course, representative dimensions and may be widely varied without 
sacrificing the advantages of the inventive structure. With particular 
reference to the member 10, it is seen as being generally rectangular in 
plan, having opposite ends 14 and 16, top and bottom flat surfaces 18 and 
20 and opposite straight sides 22 and 24. Linear measuring indicia 26 and 
28, respectively, are provided along the edges 22 and 24. These are shown 
in representative fashion, since they may take many forms and, by way of 
example, may be different scales such as found on architectural, 
engineering and like measuring elements. Scales of different amplitude or 
degree will appear on the under-side (reverse) of the member, the member 
being reversible from obverse to reverse conditions to bring a wide 
selection of scales into play. The members may, if desired, be transparent 
and the indicia portions opaque, for example. Since the members are 
similar, except for the essential fact that one member acts as the male 
and the other as the female, what is said about the member 10 as to ends, 
sides, surfaces, scales, etc., applies also to the member 12 and, in the 
interests of clarity and brevity, a detailed repetitive description is 
omitted. 
The members are interconnected at the corner of the L by pivot means 30 on 
an axis normal to the general plane of the members. The meeting ends of 
the members are reduced in thickness to afford a lap joint 32 so that the 
members are essentially coplanar; i.e., in either reverse or obverse 
position they will lie "flush-to-the-surface" on the drawing or the like 
being measured or estimated. The pivot comprises an upright circular 
"button" or "stud" 34 integral with the member 12 and a complementary 
circular opening 36 in the member 10. The stud has an annular rib 38 which 
mates with an annular groove 40 within the opening 30 (FIG. 3) for 
securing the joining of the two members. 
The members are preferably formed of any suitable, commercially available 
material, such as plastic, of a relatively stiff but at least slightly 
temporarily distortable nature so that, when the members are assembled at 
the pivot 30, the rib on the stud will be received by and have a light but 
effective force fit with the groove 40 in the opening 36, thus affording a 
snap-in/snap-out interconnection so that the members can be manually 
separated for use in the in-line mode of FIG. 4 to be presently described. 
The nature of the force fit is such as to enable pivoting of the member 12 
from the position or mode shown in FIG. 1 to the mode or position of FIG. 
2 wherein an inverted L is achieved by the members. Since it is important 
that the members bear a right-angled relation to each other in both modes, 
detent means are provided between the members in the area of the pivot 30 
so as to releasably interlock the members. A suitable form of detent means 
is seen in FIG. 3 as including recesses 42 in the bottom of the end of the 
member 10 and matching nodes 44 on the associated end of the other member 
12. Because of the nature of the material of which the members are formed, 
as discussed immediately above, the detent force is relatively easily 
overcome by manual force in changing the positions of the members from the 
FIG. 1 mode to that of FIG. 2. 
Because of the snap-in/snap-out nature of the parts at the pivot 30, the 
members may be separated and reassembled in a third mode as seen in FIG. 
4, wherein the members are arranged in end-to-end fashion to achieve an 
elongated straight edge. For this purpose another snap-in/snap-out means 
is employed, taking the form of pockets 46 in the reduced-thickness end 16 
of the member 10 and projections 48 at the reduced-thickness end of the 
member 12. The projections 48 are releasably force-fitted into the pockets 
46 to effect the interconnection as seen in FIGS. 4 and 5. The force fit 
may be relatively easily manually overcome in order to separate the 
members. Here, as in the case of the pivot 30, representative 
interconnecting means are shown by way of example and wide variations in 
details may be indulged without departing from the basic thrust of the 
invention. This observation applies of course to other details chosen for 
purposes of disclosure. 
Reference will now be had to FIGS. 6 and 7 for a disclosure of a modified 
form of member 50 which may be substituted for the members 10 and 12. This 
member has one end provided with pivot and detent components 52 and 54, 
respectively, like those already described, however, in this modified 
version, the pivot and detents are offset from the centerline of the 
radius end accordingly to the left of that point to allow for proper 
alignment of both vertical and horizontal scales when in "L" and/or 
inverted "L" positions (modes) (refer to FIG. 6). The member has an 
elongated body 56 from which "arms" 58 extend symmetrically laterally to 
provide pivots 60 on axes parallel to the length of the member. Each of 
these pivots allows for mounting an interchangeable, axial-rotating wing 
element 62. Each wing is of generally V section as seen in elevation or in 
section in a plane normal to the pivot axes, having top and bottom faces 
64 and 66 converging to a relatively narrow edge or "point" 68. Each wing 
is configured at 70 to enable limited rocking about its pivot to engage 
flush contact with the measured surface. Detent means 72 is provided to 
releasably retain the wing in flush-to-surface position. Compare full and 
dotted-line positions in FIGS. 7 and 8. Note that in the modified form, to 
allow for elongated measure via detaching the two members and joining them 
at their ends such as depicted in FIG. 4, the "arms" 58 as well as the 
wings 62 must be one-half in cross-section as shown in FIG. 8 to allow for 
complimentary "mating" to occur. 
As seen in full lines in FIG. 7, the bottom faces of the wings engage the 
surface being measured and the top faces slope downwardly to the edge 68 
along which indicia are provided. The advantage is that the straight edge 
along the narrow portion 68 is easier to read relative to the area being 
measured since it is flush with the surface. Another feature of this phase 
of the invention is that the top and bottom faces of each wing are 
slightly concave so that contact with the surface being measured is 
limited to essentially two contact lines 76 and 78 as distinguished from 
flat face-to-face contact. The line contact results in cleaner and neater 
use of the wings, since they, because of their configuration, minimize the 
pick-up of dirt, etc., from the face of the drawing being measured. Since 
the wings are symmetrical from top to bottom, they function identically 
whether the member 50 is in obverse or reverse position. 
As will have been seen from the foregoing, the invention provides a simple, 
low-cost, convenient measuring tool that affords substantial versatility 
in use because of the several modes of operation. Features in addition to 
those pointed out will readily occur to those versed in the art, as will 
many modifications in the preferred embodiments disclosed, all without 
departure from the spirit and scope of the invention.