Method of continuously measuring a successively conveyed lengthy body

A method of continuously measuring a successively conveyed lengthy body. Light sensors are located above and laterally of the conveying path of a conveyor and measure the distances from the sensors to various points on the surface of the lengthy body while being conveyed. The sectional area of the body is then calculated by a computer, and further the weight of the body is calculated. Various kinds of light sensors are applicable to the method of this invention.

BACKGROUND OF THE PRESENT INVENTION 
1. Field of the Invention 
The present invention relates to the measurement of the volume or weight of 
a successively conveyed lengthy body, and particularly to a method of 
measuring distances from a sensor or sensors to various points on the 
surface of a successively conveyed lengthy body on a conveyance path and 
calculating a sectional area thereby obtaining the volume or weight of the 
body per unit length. The present invention further relates to a method of 
measuring distances from sensors to the surfaces of the lengthy dough body 
which is successively conveyed in the production of bread or confectionery 
products, calculating the sectional area of the body, and then calculating 
the volume or weight of the body without using any conventional mechanical 
method. 
2. Description of Prior Art 
The measurement of the weight of a body which is successively conveyed has 
conventionally been made by various methods, for instance, a balance 
method, a spring expansion and compression method, and a strain meter 
method. Apparatuses using these methods are disposed midway of a conveyor 
by which a body to be measured is carried, and weight measurements per 
unit length of the body are integrated to obtain the weight value of the 
body of a required length. 
These mechanical methods have proved to be satisfactory, to a certain 
extent, when a powdery or granular material is conveyed. However, none of 
them could attain accurate measurements because the torque in the 
conveying direction caused by the conveyance of the material influences 
the measurement of the weight. Further, it is theoretically impossible for 
these methods to measure a lengthy rigid body. 
Japanese Patent Early-Publication (KOKAI TOKKYO KOHO) No. 14128/85 teaches 
an apparatus for measuring the weight of massive substance, in which an 
X-ray generator and aligned X-ray linear sensors are oppositely disposed. 
The massive substance to be measured is moved relative to the X-ray 
generator and the X-ray linear sensors detect the X-rays transmitted 
through the massive substance thereby computing the weight of the massive 
substance. This apparatus is based on a theory that the amount of 
transmitted X-rays depends on the mass of substance through which X-rays 
are transmitted, so that rapid and accurate measurement is expected. There 
is no teaching in this prior art publication that the apparatus can also 
be used in the measurement of lengthy bodies. Again, a specially designed 
cover is required to protect the X-ray generator from the leakage of 
X-rays, and X-ray linear sensors should also be disposed underneath the 
massive substance in alignment. Furthermore, in view of safety, the 
apparatus of the prior art is not applicable to the measurement of food, 
for example, dough or confectionery. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide a method of 
continuously measuring a successively conveyed lengthy body by providing 
sensors to measure the distance between the sensors and the surface of the 
body. It is another object of the present invention to provide a method of 
continuously measuring a successively conveyed lengthy body by providing 
sensors above and laterally of the body to accurately measure the distance 
from the sensors and the surface of the body and calculating the sectional 
area and in turn the volume and furthermore the weight of the body. 
It is still another object of the present invention to provide a method of 
measuring a successively fed lengthy body, by which a quantitative feeding 
of, for instance, a pasty product material into a dividing station in the 
process of making bread or a product to be cooked can be satisfactorily 
conducted. It is still a further object of the present invention to 
provide a method of continuously measuring a successively fed lengthy 
body, by which the weight of a raw material or an elongate solid material 
is measured and the material is divided into portions of desired weight. 
In one aspect of this invention, a method of continuously measuring a 
successively conveyed lengthy body is provided, which comprises moving a 
sensor back and forth in a horizontal and transverse direction above the 
conveying path of a conveyor from one side to the other, operating the 
sensor to measure the distance from the sensor to various points on the 
surfaces of a lengthy body while being conveyed on the conveyor, 
calculating the height of the lengthy body at each point measured, 
calculating the sectional area of each section of the lengthy body 
comprising the points measured, and calculating the volume of a fraction 
of the body by multiplying the sectional area by a predetermined length of 
the fraction of the body. 
In another aspect of this invention, a method of continuously measuring a 
successively conveyed lengthy body is provided, which comprises operating 
a plurality of sensors to measure the distances from the sensors to 
various points on the surfaces of a lengthy body while being conveyed on a 
conveyor, the plurality of sensors being disposed in a horizontal and 
transverse direction above the conveying path of the conveyor, calculating 
the height of the lengthy body at each point measured, calculating the 
sectional area of each section of the lengthy body comprising the points 
measured, and calculating the volume of a fraction of the body by 
multiplying the sectional area by a predetermined length of the fraction 
of the body. 
Various kinds of sensors are applicable to the present invention. For 
example, an infrared ray sensor composed of an infrared ray generator and 
an infrared ray sensing element may be utilized. This infrared ray sensor 
works as a unit, so that it can attain measurement of distances without 
the help of any other sensing elements. Similarly, by utilizing 
ultraviolet ray sensors, visible light sensors, or laser beam sensors, 
which also work as a unit as light or beam generators and light or beam 
sensing elements, a simple and accurate method of measuring distances 
between the sensors and the surfaces of the successively conveyed lengthy 
body is realized. 
Thus, according to the present invention,the volume or weight of a lengthy 
body can be simply and continuously measured with great accuracy 
regardless of whether the body to be conveyed is a powdery or granular 
material, whether the body is in the form of a lengthy rigid body such as 
an elongate pillar, or whether the body is a pasty product such as bread 
dough or a material to be cooked. 
On the basis of the distance information from sensors, a computer may 
calculate the sectional area of the body and then the volume or the weight 
of the body per unit length is calculated. The computed values are 
compared with predetermined control values, and the computer transmits 
commands, for example, to a dough dividing apparatus and so forth. 
In one mode of the invention, a sensor located above the conveying path is 
adapted to move back and forth in a horizontal and transverse direction 
above a lengthy body to be measured and emits rays or beams and senses the 
reflection from the surface of the body. The sensor, thus, detects the 
distances from the sensor to various points on the body's surface and 
transmits electric signals as distance information to a computer which 
then calculates the height of the object, the sectional area of each 
section of the lengthy body, and the volume of a fraction of the object. 
When the lengthy body is thicker and has recess portions in the side walls, 
no accurate measurement may be obtained, consequently, in each side of the 
conveying path additional sensors are provided. 
Furthermore, a plurality of fixedly disposed sensors may also be utilized 
in the present invention. These sensors are located in a horizontal and 
transverse direction above the conveying path to measure the distances in 
a stationary condition without moving sensors thereby to obtain more 
accurate measurements. 
Since the method of this invention can achieve the measurement of the 
weight of any lengthy body which is successively conveyed on a conveyor, 
the method serves as a method of controlling the quantity and quality of 
products in a mass production process.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
An embodiment of the present invention will now be described with reference 
to the drawings. 
In FIG. 1, dough 2 is conveyed on a conveyor belt 1 above which a sensor 3 
is located. The sensor 3 reciprocates in a horizontal direction which is 
transverse to the conveyance path above the dough 2, and the directions of 
its movement are shown by the arrows m and m'. The sensor 3 emits light 
and senses its reflection from portions on the surfaces of the body at 
each measuring point that is spaced apart from the adjacent points by a 
certain incremental distance m". An example of a distance-measuring light 
sensor, which is commercially available, is sensor PA-1810 made by Lead 
Electric Co., Ltd., Japan. Typically, the sensor detects the amount of 
displacement of a light spot on the surface of a body moving at a known 
velocity to compute the distance of the reflecting surface from the 
sensor. Ultrasonic sensors which measure distance by the time it takes for 
sound waves to be reflected back to the sensor are also well known. 
The light emitted from the sensor 3 and the reflection from the dough 
surface are indicated by vertical lines H. The sensor 3 is composed of a 
light emission element and a reflection sensing element which constitute 
the sensor working as a unit. 
Light emitted from the light emission element reflects at the dough 
surface, and the reflection is detected by the reflection sensing element. 
This reflection has distance information responding to the distance from 
the sensor 3 to the dough surface and is converted into an electric 
signal. 
The sensor 3, while moving reciprocally above the dough 2 which is being 
conveyed, transmits the electric signal at each measuring point to a 
computer. The computer, upon receiving the signal, calculates the height 
of dough at each measuring point and multiplies the value of the dough 
height by the value of the incremental distance m" to obtain an 
incremental area of the dough. The total cross-sectional area is then 
obtained by totalling all of the incremental areas across the width of the 
cross-section of the dough, which will be referred to as "sectional area 
A," when the sensor 3 completes its transverse movement covering the 
stretch indicated by the arrow m. The computer multiplies the value of the 
sectional area A by a predetermined length l that corresponds to the 
distance of the dough conveyed in a unit time interval, to obtain the 
volume of the relevant portion of the dough and then multiplies the volume 
of the dough by the specific gravity P of the dough to obtain the weight 
of the dough per unit length l. The sensor 3 then moves as shown by an 
arrow m' to the original position, while measuring distances in the same 
manner as described above. Thus the sectional area of the dough covered by 
the return stroke of the sensor 3 is obtained, and this area will be 
referred to as "sectional area B." The sectional area B is then multiplied 
by l and further multiplied by P to obtain the weight of the dough portion 
for the succeeding length l. If the weight measurements of the dough 
portions are expressed as X.sub.1, X.sub.2 . . . , they may be expressed 
by the following equations: 
EQU X.sub.1 =A.times.l.times.P, X.sub.2 =B.times.l.times.P 
When the dough is high, a pair of sensors (4,5), one provided at each side 
of the conveyor (1), perpendicularly reciprocate to measure the horizontal 
distances from the traveling sensors (4,5) to points on the dough surfaces 
thereby supplementing the distance information with information about each 
side of the dough body (2). This process is desirable because, if the 
dough is high, measurement taken by the overhead sensor (3) is liable to 
be inaccurate. For example, if the dough has a depression on its side, the 
sensor (3) cannot detect the existence of the depression. Thus the 
sectional area of the dough calculated should be greater than the accurate 
sectional area due to the area of the depression. However by using the 
pair of sensors (4,5), the corrected sectional area of dough is calculated 
as discussed below. 
In this embodiment, the dough is assumed to have three portions, that is, a 
middle portion (2a) defined by two planes (P.sub.1,P.sub.2) vertical to 
and in the longitudinal direction on the conveyor belt (1) and the side 
portions (2b.sub.1,2b.sub.2) of which are portions of the dough other than 
the middle portion. The planes (P.sub.1,P.sub.2) are spaced apart from the 
sensors (4,5) by predetermined distances which are used as reference 
distances for calculating the sectional areas of the side portions 
(2b.sub.1,2b.sub.2) as discussed below. In this embodiment, the planes 
(P.sub.1,P.sub.2) are selected so that most of the dough body (2) can be 
included between them. The top sensors (3) move at a predetermined height 
above the conveyance belt (1) across the middle portion (2a) of the dough 
body (2) and measures the vertical distance to each point on the top 
surface. Then the sectional area of the middle portion (2a) is calculated 
as explained above. 
While moving the top sensor (3), the pair of side sensors (4,5) move back 
and forth on both sides of the conveyance path across the heights of the 
side portions (2b.sub.1,2b.sub.2) of the lengthy body (2) as indicated by 
the arrows n and n' in FIG. 2 and measures the distance from the sensors 
to each point on the side surfaces of the side portions 
(2b.sub.1,2b.sub.2). Then, the horizontal distances from the vertical 
planes to each point on both side surfaces of the side portions 
(2b.sub.1,2b.sub.2) of the dough body are calculated by subtracting the 
measured distance at each point on the side surfaces from the 
predetermined distance between the respective planes (P.sub.1,P.sub.2) and 
the relevant side sensors (4,5). The sectional areas B of the side 
portions (2b.sub.1,2b.sub.2) are calculated as described above. The total 
sectional area is then obtained by adding the sectional area of the middle 
portion (2a) and the sectional areas of the side portions 
(2b.sub.1,2b.sub.2). Finally the volume of the relevant portion of the 
dough body (2) can be obtained by multiplying the total sectional area by 
the predetermined length l as explained above. The vertical distance 
information on the varying top surface of the dough body 2 provided by 
sensor 3, as described above, is used to obtain the incremental heights 
across the top surface of the dough, whereas the horizontal distance 
information provided by sensors 4, 5 reciprocated in directions n and n' 
is used to obtain the incremental widths over the side surfaces of the 
dough. Alternatively, arrays of sensors may be used similar to that show 
in FIG. 5. Then, a more accurate total sectional area is obtained by 
computation using the incremental heights and the incremental widths 
measured by the sensors. 
The transverse movement of the overhead sensor 3 is further shown in FIGS. 
3 and 4. In these figures, the dough 2 is conveyed by the conveyor belt 1, 
and the tails of the sensor 3 are shown by the lines J and K. In FIG. 3, 
the speed of the sensor 3 relative to the speed of the dough is much 
higher than the case of FIG. 4, and the halt time at each side of the 
dough is longer. Thus, the halt time substantially corresponds to the 
distance l. The trail of the sensor 3 is made by its reciprocative 
movement, which begins at a point a and continues through points b, c, d, 
e . . . Points on the lines J and K are those where the sensor 3 takes 
measurement. When the relative speed of the sensor 3 is lower and the halt 
time is very short, the trail may be as shown in FIG. 4. In this case, 
measurements must be adjusted accordingly. Another embodiment of this 
invention is shown in FIG. 5, in which instead of the traveling sensor (2) 
in FIG. 2, a plurality of aligned sensors (6) are provided horizontally 
above the conveyor belt (1) in a direction transverse to the conveyance 
path of the conveyor belt (1), each being spaced apart from the adjacent 
ones by a short distance m'". As shown in FIG. 5, the pair of side sensors 
(4,5) are provided and obtain information about the horizontal distances 
to the respective points on both side surfaces of the side portions 
(2b.sub.1,2b.sub.2). Thus, by adding the sectional areas of the middle and 
side portions (2a, 2b.sub.1,2b.sub.2 ) described above, the more accurate 
calculation is attained in this embodiment. The pair of sensors (4,5) can 
be replaced with a pair of sensor arrays, one on each side of the conveyor 
belt (1). A plurality of measuring points for this embodiment are shown in 
FIG. 6. As will be seen in the drawing, measurement is conducted at each 
time when the dough moves a distance l, and the computer calculates the 
dough weight in the similar manner as mentioned in the preceding 
embodiments. In either embodiment, the shorter the length l, the greater 
the accuracy of measurement of the present invention. 
As described above, the present invention does not use any mechanical 
measurement. Therefore, various accidents attributable to external causes 
can be prevented. In using the mechanical measurement, if, for instance, a 
balance is disposed beneath the conveyor belt to mechanically measure the 
weight of dough 2 conveyed by the belt, the tension of the belt tends to 
disturb the measurement of the weight of the dough 2, and no accurate 
weight measurement can be obtained. According to the present invention, 
the sectional area of dough being successively conveyed can be 
continuously measured by the sensor to continuously measure the volume and 
weight of each of very minute portions of the dough, so that the weight of 
a specified length of the dough can be easily computed by integration. 
According to the present invention, no particular device, such as the 
X-ray protector or X-ray sensing elements are required. 
Although the embodiments of this invention have principally referred to the 
measurement of the volume or weight of dough, this invention is in no way 
limited to the measurement of dough and can also be utilized for the 
measurement of a plastic material, a viscoelastic material and a rigid 
lengthy material.