U.S. patent application number 12/613720 was filed with the patent office on 2011-05-12 for method for manufacturing high-visibility measurement tool.
This patent application is currently assigned to EMPIRE LEVEL MFG. CORP.. Invention is credited to JOHN R. CHRISTIANSON, CHARLES DUNN KIM.
Application Number | 20110108428 12/613720 |
Document ID | / |
Family ID | 43970200 |
Filed Date | 2011-05-12 |
United States Patent
Application |
20110108428 |
Kind Code |
A1 |
CHRISTIANSON; JOHN R. ; et
al. |
May 12, 2011 |
Method for Manufacturing High-Visibility Measurement Tool
Abstract
A method for manufacture of a substantially flat rigid
measurement tool of the type formed of a substantially non-ferrous
lightweight anodized metal plate with measurement markings thereon.
The inventive method includes the steps of anodizing the metal
plate to create a dark anodized layer, forming the flat rigid
measurement tool from the anodized metal plate, and creating
non-removable substantially white measurement markings by oxidizing
selected mark-areas of the dark anodized surface to a depth below
the anodized layer. The markings are created by application of a
laser energy. The metal plate contains aluminum and the
non-removable substantially white markings are formed by oxidized
aluminum.
Inventors: |
CHRISTIANSON; JOHN R.;
(WAUKESHA, WI) ; KIM; CHARLES DUNN; (RALEIGH,
NC) |
Assignee: |
EMPIRE LEVEL MFG. CORP.
Mukwonago
WI
|
Family ID: |
43970200 |
Appl. No.: |
12/613720 |
Filed: |
November 6, 2009 |
Current U.S.
Class: |
205/202 ;
205/199 |
Current CPC
Class: |
G01B 3/566 20130101 |
Class at
Publication: |
205/202 ;
205/199 |
International
Class: |
C25D 11/24 20060101
C25D011/24; C23C 28/00 20060101 C23C028/00; C25D 11/18 20060101
C25D011/18 |
Claims
1. In a method for manufacture of a substantially flat rigid
measurement tool of the type formed of a substantially non-ferrous
lightweight anodized metal plate with measurement markings thereon,
the improvement comprising: anodizing the metal plate to create a
dark anodized layer; forming the flat rigid measurement tool from
the anodized metal plate; and creating non-removable substantially
white measurement markings by oxidizing selected mark-areas of the
dark anodized surface to a depth below the anodized layer.
2. The method of claim 1 wherein the creating step is by
application of a laser energy.
3. The method of claim 2 wherein the metal plate contains aluminum
and the non-removable substantially white markings are result of
oxidized aluminum.
4. The method of claim 3 wherein: the metal plate is a
substantially rectangular extruded aluminum segment including a
main portion and two heel portions each extending along one of the
parallel sides of the major portion and orthogonal thereto; and the
creating step is performed upon such rectangular segment.
5. The method of claim 3 wherein the forming step further includes
the step of dividing the substantially rectangular extruded
aluminum segment into two triangular components each including one
of the heel portions.
6. The method of claim 5 wherein the heel portion of each
triangular component has a width greater than 0.875 inch (2.2 cm).
Description
FIELD OF THE INVENTION
[0001] This invention generally relates to hand tools. More
specifically, this invention relates to a method of manufacturing
measuring and marking tools such as rafter squares and the
like.
BACKGROUND OF THE INVENTION
[0002] Carpenters frequently use framing squares, also known as
rafter squares, of different types as a means of working more
efficiently and accurately. To insure proper perpendicularity and
angularity for correct alignment of adjacent members, rafter
squares, levels and gages are commonly employed. A metal rafter
square is widely used in carpentry. The typical rafter square has a
shape of a right triangle with a main portion and a heel portion
perpendicular to the main portion. The main portion and the heel
form a T-shaped cross-section. The heel portion extends along one
of the right-angle-adjacent sides of the main portion. The main
portion has various indicia such as periodic markings to indicate
incremental lengths or angles with respect to a pivot point at the
right angle. Some rafter squares may also include information
regarding most-common conversions.
[0003] It is important that the measuring and marking indicia be
accurate and easy to read. Some prior rafter squares are made by
stamping the markings on the main-portion surface. The stamping
process makes grooves in the main-portion surface by displacement
of metal at the surface of the main portion. Such metal
displacement may result in slight deviations in the markings. Of
course, any even slight deviation may translate in measurement
inaccuracies resulting in errors on the construction site. Clearly,
high accuracy of the measurement markings is highly desirable.
[0004] Work on a typical construction site is performed under
various lighting conditions which may vary from bright sunlight to
electric illumination. Many prior rafter squares include only a
single color such that with insufficient or excessive lighting such
markings blend with the rest of the main-portion surface and are
not easily readable. Alternatively, in some other prior rafter
squares, the markings are painted in a color contrasting the color
of the main-portion surface. However, after some use, such
painted-on color tends to rub off even if the paint has been
applied within the grooves. This results in the same single-color
effect just described. It is, therefore, desirable to have a rafter
square which is easy to use and see under various lighting
conditions and for extended periods of time.
[0005] The heel of the rafter square is most often used to
reference the square along an edge of a framing wooden workpiece.
Often, however, some wooden boards do not have a sufficiently sharp
edge for such reference. In such cases, the heel of the square
slips off the edge and makes it very hard to retain the rafter
square in a fixed position for making necessary measurements and
marking on the wooden board. It would be advantageous to have a
rafter square which accommodates various shapes of wooden-board
edges and allows to retain the square in a fixed position.
OBJECTS OF THE INVENTION
[0006] It is an object of the invention to provide an improved
method for manufacturing a measuring tool such as a rafter square
overcoming some of the problems and shortcomings of the prior art,
including those referred to above.
[0007] Another object of the invention is to provide an improved
method for manufacturing a rafter square with high-accuracy marking
indicia.
[0008] Another object of the invention is to provide a method of
manufacturing a high-visibility and easy-to-use rafter square which
maintains such characteristics for an extended period of time.
[0009] Still another object of the invention is to provide an
improved rafter square which accommodates various shapes of
wooden-board edges and allows to retain the tool in a fixed
position for performing measurements and markings.
[0010] How these and other objects are accomplished will become
apparent from the following descriptions and the drawings.
SUMMARY OF THE INVENTION
[0011] The present invention relates to a method for manufacture of
a substantially flat rigid measurement tool of the type formed of a
substantially non-ferrous lightweight anodized metal plate with
measurement markings thereon. In the inventive method, the metal
plate is anodized to create a dark anodized layer. It is preferred
that the dark anodized layer results in a dark preferably matt
finish of the metal-plate surface. While the matt finish is
preferred to reduce the surface glare, a glossy finish may also be
made if so desired. The flat rigid measurement tool such as a
rafter square is formed from such anodized metal plate.
Non-removable substantially white measurement markings are created
by oxidizing selected mark-areas of the dark anodized surface to a
depth below the anodized layer.
[0012] In highly preferred embodiments, the creating step is by
application of a laser energy. The metal plate preferably contains
aluminum. The non-removable substantially white markings are formed
by oxidized aluminum with the substantially white color resulting
from formation of aluminum oxide. The application of laser energy
also preferably forms grooves in the surface of the metal plate.
The depth of the grooves is selected by programming a controller
which contains programmable information regarding the laser
application. Because the grooves and the white-color markings are
formed by application of the laser energy, such process
substantially eliminates any displacement of the metal at the plate
surface. This, along with the programmable laser controller,
results in highly accurate measurement markings. Furthermore, in
the absence of any color coating, the white markings are
substantially permanent due to the change in a chemical state of
the metal plate surface. The white markings are highly visible on
dark anodized layer. The white-on-dark contrast of the markings is
maintained even after an extended use with repetitive rubbing.
[0013] In preferred embodiments, the metal plate is a substantially
rectangular extruded aluminum segment including a main portion and
two heel portions each extending along one of the parallel sides of
the main portion and orthogonal thereto. It is preferred that the
step of creating the measurement markings is performed upon such
rectangular segment. The forming step further includes the step of
dividing the substantially rectangular extruded aluminum segment
into two triangular components each including one of the heel
portions. The inventive method preferably includes further steps of
forming and finishing the measuring tool. Such steps are disclosed
in commonly-owned U.S. Pat. No. 5,901,445 (Woods et al.), the
entire contents of which are incorporated herein by reference.
[0014] It is further preferred that the heel portion of each
triangular component has a width which is greater than 0.875 inch
(2.2 cm), preferably about 1.125 inch (2.9 cm). Such enlarged heel
dimension allows improved holding of the tool on boards which in
turn further improves accuracy of the measurements and markings of
the board.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a front perspective view of a rafter square made
according to a method of the present invention.
[0016] FIG. 2 is a side perspective view from below of the rafter
square of FIG. 1.
[0017] FIG. 3 is a fragmentary front view of the rafter square of
FIG. 1.
[0018] FIG. 4 is a front plan elevation showing product positions
and configurations as they occur during the forming step.
[0019] FIG. 5 is a front plan elevation of two formed rafter
squares.
[0020] FIG. 6 is a cross-sectional view of an initial extruded
metal plate.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0021] The present invention relates to a method for manufacture of
a substantially flat rigid measurement tool such as rafter square
10 of the type formed of a substantially non-ferrous lightweight
anodized metal plate 11 with measurement markings 12 thereon. FIGS.
1-3 illustrate metal plate 11 anodized to create a dark anodized
layer 13. Rafter square 10 shown in FIGS. 1-3 has dark anodized
layer 13 which results in a dark preferably matt finish of a
surface 14 of metal-plate 11. As seen in the FIGURES, measurement
markings 12 are non-removable substantially white markings.
Markings 12 are created by oxidizing selected mark-areas 15 of dark
anodized surface 14 to a depth below anodized layer 13.
[0022] In highly preferred embodiments, markings 12 are created by
application of laser energy. Metal plate 11 shown in the FIGS. 1-3
contains aluminum. Non-removable substantially white markings 12
are formed by oxidized aluminum with the substantially white color
resulting from formation of aluminum oxide which has the
substantially white color. The application of laser energy also
forms grooves 16 in surface 14 of metal plate 11. The depth of
grooves 16 is selected by programming a controller which contains
programmable information regarding the laser application. As
further seen in FIGS. 1-3, white markings 12 are highly visible on
dark anodized layer 13.
[0023] FIGS. 4-6 show that initially metal plate 11 is a
substantially rectangular extruded aluminum segment 20 including a
main portion 21 and two heel portions 22 each extending along one
of the parallel sides 23 of main portion 21. FIG. 6 best shows that
the heel portions are orthogonal to main portion 21. FIG. 4
illustrates that measurement markings 12 are created upon
rectangular segment 20. FIG. 5 shows that the forming step further
includes the step of dividing rectangular extruded aluminum segment
20 into two triangular components 24 each including one of heel
portions 22.
[0024] FIG. 4 depicts the different positions and configurations of
segment 20 as it moves from a first position 31 and are
successively transformed into intermediate products 32, 33 and 34.
A first hole-punching tool forms holes 55a-55d in second
intermediate product 32. A second hole-punching tools forms holes
73a-73c comprising the second set of holes in third intermediate
product 33. A laser device forms measurement markings 12 in forth
intermediate product 34. As seen in FIG. 4, hole 73b extends along
a hole axis 110.
[0025] FIG. 5 shows that forth intermediate product 34 is divided
into two semifinished components 107, 109 by moving a cutting tool,
e.g., a milling tool, along hole 73b and, particularly, along axis
110. To divide a product 34 into two semi-finished components 24,
24, the length of the tool-receiving hole 73b is extended by
milling away material at the hole ends until the hole "breaks out."
Components 24 are then finish-machined, thereby making two rafter
squares 10 from each third intermediate product 34.
[0026] FIG. 2 further illustrates that heel portion 22 of each
rafter square 10 has an enlarged width 25 which is greater than
0.875 inch (2.2 cm), preferably about 1.125 inch (2.9 cm). Such
enlarged heel dimension allows improved holding of the tool on
boards which in turn further improves accuracy of the measurements
and markings of the board.
[0027] While the principles of the invention have been shown and
described in connection with specific embodiments, it is to be
understood that such embodiments are by way of example and are not
limiting.
* * * * *