Coded tape for determining tire size

In a measuring device for tires, wherein the device comprises a length of flexible tape adapted to overlap an annular portion of the outer peripheral surface of a tire, the improvement comprises the addition to the outer surface of the tape of a plurality of circumferentially extending discrete bands, identifiable via individual codes marked thereon consisting of other than physical dimensions, for determination of the sizes of the tires.

TECHNICAL FIELD 
The field of art to which this invention pertains is that of pneumatic 
tires, particularly to the use of a measuring tape adapted to 
circumferentially surround and overlap an annular portion of the outer 
peripheral surface of the tire for determining the size thereof. 
BACKGROUND OF THE ART 
Tire dimensions are important, particularly tire diameters. For example, 
tires should be matched, in terms of diameter when mounting them in dual 
wheel applications, such as on heavy duty trucks, where matched tire 
sizing is required for load carrying purposes, etc. In addition, in 
retreading operations it is important to determine the exact tire 
dimensions, particularly in minimum and maximum diameters of buffed tire 
casings in order to select the proper matrix for retreading purposes. One 
way to measure the buffed diameter of a tire casing is to pull a band 
tightly around the center of the casing and then reading the physical 
dimension of the tire, generally in vernier scale calibration, in terms of 
either circumference or, if so calibrated, directly in diameter. It is 
better practice to measure the circumference of the tire and then 
calculate the diameter therefrom since a direct diameter measurement of 
the tire is more complicated due to tire contour and is often not fully 
accurate due to out-of-round conditions of the tire casing. Once the 
correct physical dimension is determined, the operator then must consult a 
separate maintenance chart in order to select the proper matrix. This is 
not only time consuming, but also can lead to errors in selecting the 
proper chart to determine the proper matrix. 
U.S. Pat. No. 1,797,389 to Woock discloses a measuring tape which is 
specifically designed and adapted for measuring the exterior 
cross-sectional peiphery or cross-sectional profile of an automobile tire. 
However, the tape is not calibrated in matrix code, is not oriented to be 
circumferentially placed around the tire and does not appear to be 
specifically used for determining matrix sizes. German Pat. No. 917,272 to 
Zangl appears to disclose a tire measuring tape somewhat similar to that 
shown by Woock. There appears to be no indication in regard to tape 
calibrations. 
U.S. Pat. No. 2,434,156 to Heintz discloses a method and device for 
retreading tires wherein a tape (not shown) is placed along line 3 such 
that the buffed contour of the tire from bead-to-bead is measured. The 
dimensions of the tire are then compared to a table, as shown in FIGS. 5 
and 8, whereupon the appropriate size matrix is chosen for retreading the 
tire. 
U.S. Pat. No. 3,007,251 to Rawls discloses a method and apparatus for 
measuring tire casings, both of which differ from that of the present 
invention inasmuch as they are used to measure cross-sectional contour and 
the cross-sectional dimension. In addition, the matrix appears to be based 
on the measured bead-to-bead dimension. 
U.S. Pat. No. 3,633,279 to Frezlev et al discloses an apparatus for 
measuring tire parameters of the tire carcass, which apparatus however 
does not disclose the use of circumferentially displaced tape or a 
calibrated scale which indicates matrix dimensions. 
U.S. Pat. No. 3,986,267 to Taylor discloses a tire measuring instrument for 
the diameter and bead-to-bead dimension of a tire casing and correlating 
such measurement to a particular retreading matrix. The mechanism in 
question appears to measure the cross-sectional periphery of the tire as 
well as its diameter, but not the circumferential periphery. In addition, 
Taylor does not disclose a calibrated tape which is used to indicate 
matrix dimensions. 
U.S. Pat. No. 1,962,716 to Johnson discloses a spring wire gauge for 
measuring the treads of flanged wheels that are primarily used on railway 
stock. Johnson however neither describes the form of calibrations on his 
measuring plate nor illustrates a measuring device oriented specifically 
to tires. 
U.S. Pat. No. 3,685,155 to Oblander discloses a sewing measurement device 
comprising a coded tape which is used to fit different parts of a person's 
body in order to determine body dimensions for sewing parameters. Each 
area of the strip has different indicia relating to particular body 
dimensions and these areas may be color coded to indicate particular 
deviations. 
DISCLOSURE OF THE INVENTION 
The present invention provides a solution to the prior art porblems 
pertaining to initially measuring the dimension of a tire and then 
comparing same to a table, whereupon the appropriate size matrix is chosen 
for retreading the tire. A known measuring device, comprising a length of 
flexible tape, is placed so as to circumferentially surround and overlap 
an annular portion of the outer peripheral surface or largest 
circumference of the tire. The present invention pertains to an improved 
measuring device wherein the outer surface of the tape is provided with a 
plurality of circumferentially extending discrete bounded markings, 
identifiable via individual codes consisting of other than physical 
dimensions, for determining the sizes of the tires. As will become more 
apparent, this improved measuring device may be used on new tires, worn 
tire casings, buffed tire casings, built-up tire casings prior to curing, 
and cured retreaded tires, for example. 
In terms of retreading operations, the plurality of codes preferably takes 
the form of matrix codes corresponding to a plurality of matrices or molds 
used in the curing of retreaded tires. Preferably each of the matrix codes 
corresponds to the working tolerance of its corresponding matrix, but may 
also include an undersize and/or oversize tolerance range. 
In terms of the matrix codes themselves, they may represent a tolerance 
range in terms of either tire diameter and/or tire circumference and 
furthermore, the improved measuring device of the present invention may 
also include the use of more than one plurality of differing 
circumferentially extending codes on one tape. 
The use of matrix codes directly on the measuring tape surface saves time 
and expense by providing a simple means of enabling the direct 
determination of matrices for the curing of tires inasmuch as matrix codes 
rather than direct physical dimensions are shown on the tapes. The matrix 
code can thus be read directly from the tape thereby eliminating the need 
to determine a physical dimension which in turn then needs to be compared 
with a separate reference chart in order to select the proper matrix. 
Several preferred non-limiting embodiments are shown by way of example in 
the accompanying drawings and described in detail without attempting to 
show all the various forms or modifications in which the present invention 
may be embodied. The features and advantages of the present invention will 
become more readily understood by persons skilled in the art when 
following the best made description in conjunction with the several 
drawings.

BEST MODE FOR CARRYING OUT THE INVENTION 
Referring now to the drawings, specifically FIG. 1, there is illustrated a 
perspective view of a tire 10, at least an annular central portion of 
whose circumferential outer peripheral surface 12 is enveloped by the 
coded tape 20 of the present invention. The shape, profile, actual 
construction, size or material composition of tire 10 form no part of the 
present invention. Tire 10 may be of any desired construction, be it bias, 
bias belted or radial, all of which constructions are well-known in the 
art. For example, the construction (not shown) of a conventional radial 
tire, which is described herein merely for reference and background 
purposes, may consist of one or more radial body plies preferably 
extending from bead-to-bead and consisting of a fabric material such as 
rayon, topped by two tread plies or belts of reinforcing material, such as 
for example of steel cord construction, with these tread plies in turn 
being topped by a circumferential tread portion of suitable rubber-based 
composition and tread design which is the actual road-contacting portion 
of the tire. 
The term "casing" of a tire or phrase "tire body" are generally used with 
reference to a used or worn tire whose remaining tread will be removed and 
whose crown and shoulder areas will be shaped, as needed, to conform to a 
predetermined size and shape for retreading. Such removal is normally 
accomplished via a buffing operation in a manner well-known in the art. 
Suffice to say, surface 12 may be that of a new tire, i.e. provided with a 
full depth tread surface (not shown), a tire with a worn tread surface 
(not shown), a tire whose worn tread has been buffed to the casing or, 
surface 12 may be provided with a fresh rubber prior to the curing step in 
a retreading process, for example. 
Among other uses, coded tape 20 of the present invention also finds utility 
in determining tire size in retreading operations. In retreading, 
generally each particular tire size requires its own specific matrix or 
mold which is used for curing the retreaded casing into its desired size 
and tread design configuration. For example, the primary method for 
fitting radial tire casings into matrices requires exact buffed dimension 
measurements together with, to a lesser extent, crown and bead-to-bead 
measurements. Assuming now, for discussion purposes, that tire 10 takes 
the form of a buffed casing, the buffed dimension thereof could be 
measured with coded tape 20 by pulling same tightly around the center of 
casing outer circumferential surface 12. 
Coded tape 20 may be of spring or flexible steel construction, preferably 
about 1.25 inches in width, and is, of course, of sufficient length to be 
used in connection with most tire sizes. In order to facilitate the 
handling of tape 20, the outer end portion 22 may be provided with a hand 
knob 24, directly secured thereto whereas the inner end portion 26 may be 
provided with a further hand knob 28 that is attached thereto via a 
contoured retaining bracket 30 which also permits tape end portion 22 to 
pass therethrough and slide relative to tape end portion 26, as best seen 
in FIG. 3. 
For actual measuring purposes, the zero or innermost end portion of tape 20 
may be defined by slight line 32 on transparent window 34 held, via a 
further contoured bracket 36, relative to band inner end portion 26 as 
best shown in FIG. 4. FIG. 5 also shows the use of inner bracket 38 which, 
similar to bracket 30, partially encircles tape portions 22 and 26 while 
yet permitting relative transverse sliding motion therebetween. It should 
be noted that the specific shape, construction and material composition of 
coded tape 12 forms no part of the present invention and preceding 
description is but for disclosure and enablement purposes. 
At least a portion of the annular outer surface 40 of tape end portion 22 
is provided with a plurality of matrix codes 42 at specific locations in a 
vernier or linear range or scale, with each matrix code defining a band or 
range of dimensions of buffed tires that fit within a particular matrix. 
For example, as shown in FIG. 2, sight line 32 falls between lines 44 and 
46, which define the upper and lower limit, respectively, of the range of 
tire casing dimensions usable with a matrix or mold denominated by symbols 
MF. Looking at it another way, the range between lines 44 and 46 (matrix 
MF) defines the working tolerance asssociated with the matrix, i.e. the 
maximum and minimum dimensions of buffed casings usable in that particular 
matrix without further changes. 
Looking now at matrix MJ in FIG. 2, the range between line 44 and 46 again 
represents the working tolerance of the matrix. The range or band 48 
defined between low limit line 46 and undersize limit line 50 defines the 
undersize tolerance of matrix MJ. If, for example, sight line 32 were to 
fall within band 48, the tire casing will have to be built up a 
predetermined amount sufficient so its built-up dimensions fall within the 
working tolerance of matrix MJ. If on the other hand, for instance, sight 
line 32 were to fall into band 52, between upper limit line 44 of matrix 
MJ and undersize limit line 54 of matrix MK, the casing cannot be used in 
either matrix MJ (since it is too small, i.e., the casing is too large) or 
in the next tire larger matrix MK (since it is too large, i.e., the casing 
is too small). 
Turning now to FIG. 6, it takes the form of a fragmentary plan view of a 
portion of a further embodiment of the coded tape of the present 
invention. Specifically FIG. 6 depicts a segment of outer end portion 122 
of a coded tape 120 where outer surface 124 is provided with two 
transversely adjacent, but different pluralities of circumferentially 
extending matrix codes 126, 130, separated by circumferential centerline 
120. For example, letting broken line 132 represent an imaginary sight 
line, it should be evident that the tire casing would fit into any one of 
the four matrices, i.e., matrices 3A and 3D of matrix codes 126 as well as 
matrices 3B and 3C of matrix codes 130. On the other hand, the location of 
imaginary sight line 134 indicates that the tire casing will only fit into 
matrices 9U and 4U of matrix codes 130. Matrix codes 126 and 130 may 
represent two different lines of molds for two different lines of tires. 
For example, code 126 may be utilized for all-season type tires whereas 
code 130 may be used for snow tires. If desired, additional matrix codes 
could be added to coded tape 120, if compatible. 
At this point it should be evident that the use of one or more pluralities 
of circumferentially extending matrix codes, such as 42 in FIGS. 1 and 2 
as well as 126 and 130 in FIG. 6, save time and expense by providing a 
simple means of enabling direct determination of matrices for the curing 
of tires. Basically, matrix codes rather than physical dimensions are 
shown on tapes 220 (FIG. 1) and 120 (FIG. 6). Thus, the matrix code, by 
being provided on the tape itself, can be read directly from the tape 
thereby eliminating the need to determine a physical dimension which in 
turn then needs to be compared to a separate reference chart in order to 
select the proper matrix. The system of matrix codes, provided directly on 
the measuring tape, may of course utilize any type of desired indicia, be 
it numerals, letters, differing colors, etc., as long as they are provided 
at specific locations on a measuring tape and occupy a linear range 
defined for each matrix. 
From the foregoing, it is believed that those familiar with the art will 
readily recognize and appreciate the novel concepts and features of the 
present invention. Obviously, while the invention has been described in 
relation to only a limited number of embodiments, numerous variations, 
changes, substitutions and equivalents will present themselves to persons 
skilled in the art and may be made without necessarily departing from the 
scope and principles of this invention. As a result, the embodiments 
described herein are subject to various modifications, changes and the 
like without departing from the scope and spirit of the invention, with 
the scope thereof being determined solely by reference to the claims 
appended hereto.