JP2001026326A - Fed paper separating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a proper paper feeding capability by correcting a paper feeding pressure deflected from a proper value. SOLUTION: This fed paper separating device is constituted such that paper sheets S are loaded on the paper sheet loading surface 3 of a bottom plate 2, pressing a paper feeding roller 4 to a front end of the upper most sheet of the paper sheets S and rotating the roller 4 feeds the upper most sheet, and a separating pad 5 retains sheets S lower than the upper most sheet. A pressure with which separating pad 5 presses the paper feeding roller 4 has a larger contribution to a frequency change of the occurrence of an overlap feed than a pressure (paper feeding pressure) at which the sheets S presses the paper feeding roller 4. An energizing force of an energizing member 10 energizing the bottom plate 2 to a direction to the paper feeding roller 4 is detected to adjust it to a prescribed value. This accordingly detects the paper feeding pressure and is adjusted to the prescribed value to maintain proper paper feeding capability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding / separating apparatus used in a sheet feeding mechanism of a copying machine or the like, which separates and conveys sheets one by one so as to prevent double feeding.

[0002]

2. Description of the Related Art In recent years, machines having a paper conveying device such as a copying machine have been required to have higher speed, higher reliability, and higher productivity. From the viewpoint of ensuring high reliability even in a paper feed mechanism such as a copying machine, a “paper feed separation device” disclosed in JP-A-5-330683 and a “paper feed cassette pad pressure” disclosed in JP-A-5-238576 are disclosed. An adjustment mechanism has been proposed.

In each of these proposals, a pressure detecting device for detecting a pressure (hereinafter, referred to as a separation pressure) at which a separation pad is pressed against a paper feed roller is provided, and this pressure is made variable. Here, the paper feed roller is a member that comes into direct contact with the uppermost paper of the paper stacked in the paper feed cassette and sends out the uppermost paper by rotating in the paper feed direction. And a member for holding the lower-order paper moved in the paper feeding direction in the paper feeding cassette.

[0004]

However, in a sheet separation apparatus using a separation pad, even if the separation pressure is changed, the sheet feeding performance, especially the double feeding performance, is not significantly affected. This will be described with reference to FIGS. 9 and 10 and Table 1.

[0005] First, FIG. 9 shows the results of an experiment in which the frequency of occurrence of double feeding was evaluated by increasing the separation pressure in five stages from A to E in a certain sheet separation device. FIG. 10 shows the result of an experiment in which the pressure at which the paper feed roller is pressed against the paper (hereinafter referred to as the paper feed pressure) was increased in five stages from a to e to evaluate the frequency of occurrence of double feeding (a). 4) Graph and (b) table. Table 1 shows the results of variance analysis of the results of these experiments.

[0006]

[Table 1]

As is apparent from Table 1, most of the contribution to the change in the frequency of occurrence of double feeding (nearly 90%) is caused by the paper feed pressure. It can be said that the paper pressure is dominant. This is proved by the small error in the experiment, and the fact that "the paper feed pressure is dominant with respect to the change in the frequency of occurrence of double feeding" is unique to the equipment used in the experiment. However, it can be said qualitatively about a sheet feeding separation apparatus using a separation pad.

It is an object of the present invention to obtain a good paper feed performance by correcting the paper feed pressure to an appropriate value if it deviates from an appropriate value.

Further, the present invention is to adjust the feed pressure to an appropriate value immediately in response to a change in the feed pressure, thereby always keeping the feed pressure at an appropriate value and stabilizing the feed performance in a good state. Aim.

[0010]

According to a first aspect of the present invention, there is provided a paper separating apparatus comprising: a bottom plate having a sheet stacking surface on which sheets are stacked; and a bottom plate near a front end of the bottom plate facing the sheet stacking surface. A paper feed roller disposed to move the top paper in the paper feed direction by rotating in contact with the top paper, and a biasing member for biasing the bottom plate in a direction close to the paper feed roller, A feed pressure detecting device that detects a feed pressure that is a pressure at which the highest-order paper is pressed against the feed roller, a feed pressure adjusting mechanism that adjusts an urging force of the urging member, and the feed pressure detecting device Automatic adjusting means for controlling the paper feed pressure adjusting mechanism so that the paper feed pressure detected by the above becomes a predetermined value.

Therefore, the sheet feeding pressure can be appropriately detected and adjusted to a predetermined value.

According to a second aspect of the present invention, in the sheet separating apparatus according to the first aspect, the sheet pressure detecting device receives the sheet pressure and outputs a signal corresponding to the sheet pressure. A pressure receiving portion that forms a portion of the sheet stacking surface facing the paper feed roller;

Therefore, it is possible to constantly measure the paper feed pressure applied to the paper sandwiched between the paper feed roller and the bottom plate.

According to a third aspect of the present invention, in the sheet feeding / separating apparatus according to the first aspect, the sheet feeding pressure detecting device has a pressure receiving portion for receiving a pressure to be measured, and the pressure receiving portion is provided with the pressure receiving portion. It is disposed at a measurement position near the paper roller and at substantially the same distance as the paper feed roller with respect to the paper loading surface, and comes into pressure contact with the uppermost paper.

Therefore, it is possible to measure substantially the same pressure as the paper supply pressure applied to the uppermost paper by the paper supply roller.

According to a fourth aspect of the present invention, there is provided the sheet separating apparatus according to the third aspect, wherein the sheet pressure detecting device moves the pressure receiving portion between the measurement position and a retracted position away from the uppermost sheet. A support mechanism that movably supports the pressure receiving section, a positioning mechanism that positions the pressure receiving section at the measurement position, and a retraction mechanism that positions the pressure receiving section at a retreat position. And a retracting means for moving the pressure receiving portion to the retracted position by means of

Accordingly, the pressure receiving portion does not hinder the feeding of the uppermost sheet.

According to a fifth aspect of the present invention, there is provided the sheet separating apparatus according to the fourth aspect, wherein the retracting unit detects the start and stop of the rotation of the paper feed roller during continuous paper feeding. By the retreat mechanism, the pressure receiving part is moved to the retreat position by the start of the movement of the top paper, and after the top paper passes through the measurement position of the pressure receiving part, the pressure receiving part moves the pressure receiving part to the measurement position by the positioning mechanism. Position.

Therefore, each time one sheet of paper is fed, the paper feeding pressure is measured, and the pressure can be adjusted according to the measurement result.

The invention according to claim 6 is the invention according to claims 1, 2, and
6. The sheet feeding / separating device according to 3, 4, or 5, wherein the urging member is a compression spring, and the sheet pressure adjusting mechanism is configured to move the compression spring so as to be movable toward and away from the bottom plate. A support table sandwiched between the bottom plate and a stepping motor that generates a driving force to move the support table,
The automatic adjusting means controls the stepping motor to move the support base in a direction approaching the bottom plate when the sheet feeding pressure detected by the sheet feeding pressure detecting device is less than a predetermined value. When the sheet pressure detected by the sheet pressure detection device is higher than a predetermined value, the support table is moved in a direction away from the bottom plate.

Therefore, by using the stepping motor, the feeding pressure can be adjusted with high accuracy.

The invention according to claim 7 is based on claims 1, 2, and
6. The sheet feeding / separating device according to 3, 4, or 5, wherein the urging member is a compression spring, and the sheet pressure adjusting mechanism is configured to move the compression spring so as to be movable toward and away from the bottom plate. A support table sandwiched between the bottom plate, a DC motor that generates a driving force to move the support table, and one or more position detection sensors disposed in a movement range of the support table,
The automatic adjusting means controls the DC motor based on a signal sent from the position detection sensor to move the support table when the sheet pressure detected by the sheet pressure detection device is less than a predetermined value. When the sheet pressure detected by the sheet pressure detecting device is higher than a predetermined value, the support table is moved in a direction away from the bottom plate.

Therefore, by using the DC motor and the position detection sensor together, the paper feed pressure can be easily and accurately adjusted.

The invention according to claim 8 is the invention according to claims 1, 2, and
8. The paper feeding separation device according to 3, 4, 5, 6, or 7, wherein the paper pressure detecting device uses a strain gauge load cell as the pressure receiving portion.

Therefore, even a slight change can be detected.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a paper feed separation apparatus according to the present invention will be described with reference to FIGS. FIG. 1 is a vertical cross-sectional view illustrating a sheet feeding / separating apparatus 1 according to the present embodiment. The sheet feed separation device 1 has a bottom plate 2 on which sheets S are stacked, and a sheet stacking surface 3 near the center of the front end of the bottom plate 2 on the side where the sheets S are stacked on the bottom plate 2. A sheet feed roller 4 is provided at a position facing the sheet feed roller 4. The paper feed roller 4 is rotated by a driving force generated by a motor or the like (not shown) in the paper feed direction. In addition, the paper feed roller 4 includes
Separation pad 5 located downstream of the front end of bottom plate 2 in the sheet feeding direction
Are pressed against each other by being urged by the spring 6.

A stepped shape 7 is formed at the center of the front end of the bottom plate 2 on the side of the sheet loading surface 3 so as to be away from the front end of the sheet S. The stepped shape 7 has a strain gauge load cell 8 as a pressure receiving portion. And a part of the paper loading surface 3 is formed by the strain gauge load cell 8. A support 9 faces the lower surface of the stepped shape 7, and a compression spring 10 as an urging member is sandwiched between the lower surface of the stepped shape 7 and the support 9. The compression spring 10 urges the bottom plate 2 in a direction approaching the paper feed roller 4.

As shown in FIG. 2, the strain gauge load cell 8 has a gauge R1, a gauge R2, a gauge R3, and a gauge R on four sides of a rectangular column-shaped aluminum block 11, respectively.
4 is affixed. As shown in FIG. 3, a Wheatstone bridge 12 is formed by the four gauges R1 to R4, and an output from the Wheatstone bridge 12 is transmitted via an amplifier 13 and an A / D converter 14 to a system bus (to be described later). (Not shown).

The system bus includes a CPU (not shown) for executing various arithmetic processing and centrally controlling each unit, and a ROM.
(Not shown) and a RAM (not shown) are connected by a bus. The ROM is a medium that stores operation programs of the respective units, and the CPU controls the respective units according to the operation programs. The RAM temporarily stores various types of variable information.
Further, a part of the RAM is used as a print buffer or used as various counter areas.
In the present embodiment, the RAM is also used as a step number counter for counting the number of steps of the stepping motor. The RAM stores a target value P of the paper feed pressure and is backed up by a battery or the like.

Here, the strain gauge load cell 8, the Wheatstone bridge 12, the amplifier 13, and the A / D converter 1
4 constitute a paper feed pressure detecting device 15. The change that occurs in the current flowing through the Wheatstone bridge 12 due to the change in the resistance value of each gauge R1 to R4 of the strain gauge load cell 8 is amplified by the amplifier 13,
The data is converted into a digital value by the A / D converter 14 and sent to the CPU through the system bus, and the paper feed pressure, which is the pressure at which the uppermost paper is pressed against the paper feed roller 4, is detected.

As shown in FIG. 4, on the lower surface of the support 9,
A rack 16 that is substantially orthogonal to the support table 9 is provided, and the driving force generated by the stepping motor 18 is transmitted to the rack 16 via a pinion gear 17 so that the support table 9 approaches and separates from the bottom plate 2. Move in the direction you want.
Here, the support 9, the rack 16, the pinion gear 17, and the stepping motor 18 constitute a paper feed pressure adjusting mechanism 19.

The feed pressure adjusting mechanism 19 adjusts the biasing force of the compression spring 10 to push up the bottom plate 2 by adjusting the height of the support base 9 in accordance with the program shown in the flowchart of FIG. Adjust. First, a target value P of the paper feed pressure is read from the RAM (step S1). Next, a measured value of the paper feed pressure detected by the paper feed pressure detecting device 15 is fetched (step S2). And the measured value is the target value P
Is determined (step S3), and if they are equal (Y in step S3), the process is terminated. If not equal (N in step S3), it is determined whether the measured value is smaller than the target value P (step S4), and if it is smaller (step S4).
(Y), the sheet feeding pressure is increased by a predetermined step of the stepping motor 18 (step S5), and the process returns to step S2 to measure the corrected sheet feeding pressure. If it is determined in step S4 that the measured value exceeds the target value P (step S4).
4) N), the sheet feeding pressure is reduced by a predetermined step of the stepping motor 18 (step S6), and the process returns to step S2 to measure the corrected sheet feeding pressure. Here, step S3
The means for executing steps S6 to S6 is an automatic adjustment means. Steps S2 to S6 are repeated until the sheet feeding pressure reaches the target value P.

In such a configuration, the paper feed pressure, which is the pressure at which the paper feed roller 4 is pressed against the uppermost sheet, always has the target value P
It is desirable to take The paper feeding pressure is given by the urging of the compression spring 10, but the paper feeding pressure given by the urging of the compression spring 10 changes as the weight of the paper S stacked on the bottom plate 2 changes. The weight of the sheet S differs depending on the size even if the number of sheets is the same, and changes every time the number of sheets is changed after the sheet is fed. Therefore, in this embodiment, every time a predetermined number of sheets are fed, or every time one sheet is fed, FIG.
According to the flow chart of FIG. 7, the sheet feeding pressure is detected by the sheet feeding pressure detecting device 15 and the sheet feeding pressure is adjusted by the sheet feeding pressure adjusting mechanism 19.

Therefore, according to the present embodiment, even if the sheet feeding pressure deviates from the target value P, the sheet feeding pressure can be corrected to the target value P, so that good sheet feeding performance can be obtained.
Further, if the sheet pressure is detected and adjusted each time one sheet is fed, the sheet pressure can be immediately changed and the sheet pressure can always be maintained at the target value P, so that the sheet feeding performance can be improved. The state can be stabilized.

According to the present embodiment, the height of the support is controlled by the number of steps of the stepping motor.
There is no need to feed back the position of the support base using a sensor or the like.

In implementation, the target value P may be given an appropriate width to make it an allowable range.

Next, a second embodiment of the sheet separating apparatus according to the present invention will be described with reference to FIGS. The same parts as those described in the previous embodiment are denoted by the same reference numerals, and detailed description is omitted (the same applies to the following embodiments).

In this embodiment, as shown in FIG. 6A, the strain gauge load cell 8 as the pressure receiving portion is substantially the same as the paper feed roller 4 with respect to the paper loading surface 3 near the paper feed roller 4. The strain gauge load cell 8 is disposed at a measurement position corresponding to a distance so that the strain gauge load cell 8 receives a pressure substantially equal to the paper feed pressure received by the paper feed roller 4 from the uppermost sheet.

In the present embodiment, the strain gauge load cell 8 is movably supported by the support mechanism 20 between a measurement position and a retracted position (see FIG. 6B) away from the topmost sheet. ing. The support mechanism 20 includes a first arm 21
And a second arm 22. The first arm 21 has one end rotatably supported by a side plate (not shown), and the other end of the first arm 21 rotatably supports one end of the second arm 22. And the other end of the second arm 22 is connected to the strain gauge load cell 8.
Is attached. Near the other end of the second arm 22, there is provided a shaft 24 that slidably penetrates a long hole 23 formed in the side plate in the longitudinal direction. The longitudinal direction of the long hole 23 is a direction that approaches and separates from the bottom plate 2. In a state where the strain gauge load cell 8 is located at the measurement position, the first arm 21 and the second arm 22 are located on a straight line.

At the other end of the first arm 21, that is, in the vicinity of the joint with the second arm 22, the other end of a tension spring 25 which is a retraction mechanism having one end fixed to the side plate is fixed. On the opposite side of the first arm 21 to the side where the extension spring 25 is fixed, an action portion 27 of a measurement solenoid 26 as a positioning mechanism is attached. In the energized state of the measurement solenoid 26, the action part 27 is retracted,
The joint between the first arm 21 and the second arm 22 is pulled against the urging of the tension spring 25 to be in a state of being located on a straight line, that is, the strain gauge load cell 8.
Is located at the measurement position. When the measuring solenoid 26 is not energized, the action portion 27 is pulled out by the urging force of the tension spring 25, and the joint between the first arm 21 and the second arm 22 is pulled, thereby causing the strain gauge load cell 8 to move. Move to the evacuation position.

FIG. 7 is a timing chart showing the energization timing of the measurement solenoid 26. When the paper feed clutch is set to H, the driving force of the driving means is transmitted to the paper feed roller 4, and the top sheet starts moving. Measurement solenoid 26
Is set to a current-carrying state between the time when the topmost paper has passed the measurement position of the strain gauge load cell 8 and the time when the next topmost paper starts moving, the strain gauge load cell 8 is positioned at the measurement position, and the feed pressure is adjusted. Detection is performed. Here, evacuation means is being executed.

According to the present embodiment, since the strain gauge load cell is retracted to the retracted position during the movement of the uppermost sheet, it does not hinder the sheet feeding.

A third embodiment of the paper separating apparatus according to the present invention will be described with reference to FIG. In the present embodiment, the driving force for moving the support 9 is obtained from the DC motor 28. Since the DC motor 28 cannot perform position detection as in the case of the stepping motor, a plurality of position detection sensors 29 are arranged side by side along the moving direction of the support 9. Fillers 30 detected by these position detection sensors 29 are formed on the rack 16.

In such a configuration, the detection and adjustment of the sheet feeding pressure are performed according to the flowchart of FIG. At the time of adjustment, the position detection sensor 2 that has detected the filler 30
The position accuracy of the support table 9 is determined by the feedback from the controller 9.

[0045]

According to the first aspect of the present invention, since the paper feed pressure can be appropriately detected and adjusted to a predetermined value, a stable paper feed pressure can be secured and the paper feed performance can be improved. it can.

According to the second aspect of the present invention, in the first aspect of the present invention, since the paper feed pressure received by the paper sandwiched between the paper feed roller and the bottom plate can always be measured, the stable paper feed pressure can be maintained at all times. It is possible to secure and improve paper feeding performance.

According to the third aspect of the present invention, in the first aspect of the present invention, since the pressure substantially equal to the feed pressure applied to the uppermost sheet by the feed roller can be measured, an accurate feed pressure can be detected. In addition, the paper feeding performance can be improved.

According to the fourth aspect of the present invention, in the third aspect of the present invention, since the pressure receiving portion does not hinder the feeding of the uppermost sheet, it is possible to stably convey the sheet and improve the sheet feeding performance. Can be improved.

According to the fifth aspect of the present invention, in the fourth aspect of the present invention, the feeding pressure is measured each time one sheet of paper is fed and can be adjusted according to the measurement result. It is possible to secure a stable paper feed pressure and improve paper feed performance.

According to the invention of claim 6, according to claim 1,
In the invention described in 2, 3, 4 or 5, the use of the stepping motor enables the paper feed pressure to be adjusted with high accuracy, so that a stable paper feed pressure can be secured and the paper feed performance can be improved.

According to the invention of claim 7, according to claim 1,
In the invention described in 2, 3, 4 or 5, the combined use of the DC motor and the position detection sensor makes it possible to easily and accurately adjust the paper feed pressure.
Paper feed performance can be improved.

According to the invention of claim 8, according to claim 1,
In the invention described in 2, 3, 4, 5, 6 or 7, even a slight change can be detected, so that a stable paper feed pressure can be set immediately and the paper feed performance can be improved.

[Brief description of the drawings]

FIG. 1 is a front view showing a sheet feeding and separating device according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a pressure receiving portion in detail.

FIG. 3 is a circuit diagram showing an electrical connection of a pressure receiving unit.

FIG. 4 is a front view showing a support base and its driving structure.

FIG. 5 is a flowchart illustrating a flow of adjusting a sheet feeding pressure.

FIGS. 6A and 6B are front views showing a sheet feeding and separating apparatus according to a second embodiment of the present invention, wherein FIG.
(B) shows a state in which the top sheet is being fed.

FIG. 7 is a timing chart showing the energization timing of the measurement solenoid.

FIG. 8 is a front view illustrating a support provided in a sheet feeding / separating apparatus according to a third embodiment of the present invention and a driving structure thereof.

FIG. 9 is a graph (a) and a table (b) showing the results of an experiment in which the separation pressure was increased in five stages from A to E in a conventional sheet separation device to evaluate the occurrence frequency of double feeding.

FIG. 10 is a graph (a) and a table (b) showing the results of an experiment in which the feeding pressure was increased in five stages from a to e to evaluate the occurrence frequency of double feeding.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 paper feed separation device 2 bottom plate 3 paper loading surface 4 paper feed roller 8 pressure receiving section, strain gauge load cell 9 support base 10 urging member, compression spring 15 paper pressure detection device 18 stepping motor 19 paper pressure adjustment mechanism 20 support mechanism 25 evacuation mechanism 26 positioning mechanism 28 DC motor 29 position detection sensor S paper S3 to S6 automatic adjustment means

Claims (8)

[Claims] A bottom plate having a sheet stacking surface on which sheets are stacked, and a top plate disposed at a position near the front end of the bottom plate facing the sheet stacking surface and rotating by contacting the top sheet. A paper feed roller for moving paper in a paper feed direction; an urging member for urging the bottom plate in a direction close to the paper feed roller; and a paper feed pressure that is a pressure at which the highest-order paper is pressed against the paper feed roller. A sheet pressure detecting device for detecting the sheet feeding pressure, a sheet feeding pressure adjusting mechanism for adjusting the urging force of the urging member, and the sheet feeding so that the sheet pressure detected by the sheet pressure detecting device becomes a predetermined value. A sheet separating device having automatic adjusting means for controlling a pressure adjusting mechanism. 2. The apparatus according to claim 2, wherein the sheet pressure detecting device includes a pressure receiving unit that receives the sheet pressure and outputs a signal corresponding to the sheet pressure.
The paper feed separation device according to claim 1, wherein the pressure receiving unit forms a portion of the paper stacking surface facing the paper feed roller. 3. The sheet pressure detecting device has a pressure receiving portion for receiving a pressure to be measured, and the pressure receiving portion is substantially the same as the sheet feeding roller with respect to the sheet stacking surface near the sheet feeding roller. 2. The paper feed separation device according to claim 1, wherein the paper feed separation device is disposed at a measurement position that is a distance and pressed against the uppermost paper. 4. A paper feed pressure detecting device, comprising: a support mechanism for movably supporting the pressure receiving portion between the measurement position and a retracted position away from the topmost sheet; and moving the pressure reception portion to the measurement position. 4. A retracting mechanism that has a positioning mechanism for positioning and a retracting mechanism that positions the pressure receiving section at a retracted position, and has a retracting unit that moves the pressure receiving section to the retracted position by the retracting mechanism when the uppermost sheet is moved. Paper separation equipment. 5. The retreating means detects the start and stop of rotation of the sheet feeding roller during continuous sheet feeding, and moves the pressure receiving unit to the retreat position by the retreat mechanism before the start of movement of the top sheet. 5. The sheet separating device according to claim 4, wherein the pressure receiving unit is moved to the measurement position by the positioning mechanism after the topmost sheet has passed the measurement position of the pressure reception unit. 6. 6. The support member, wherein the urging member is a compression spring, and wherein the paper feed pressure adjusting mechanism is movable in a direction in which the compression spring approaches and separates from the bottom plate, and holds the compression spring between the bottom plate and the bottom plate. And a stepping motor for generating a driving force for moving the support table, wherein the automatic adjusting means controls the stepping motor to adjust the sheet feeding pressure detected by the sheet feeding pressure detecting device to a predetermined value. When it is less than the above, the support table is moved in a direction approaching the bottom plate, and when the sheet pressure detected by the sheet pressure detection device is higher than a predetermined value, the support table is moved away from the bottom plate. The paper feed separation device according to claim 1, 2, 3, 4, or 5, which is moved. 7. The support member, wherein the urging member is a compression spring, and wherein the paper feed pressure adjusting mechanism is movable in a direction in which the compression spring approaches and separates from the bottom plate, and holds the compression spring between the bottom plate and the bottom plate. And a D that generates a driving force for moving the support table.
A C-motor, and at least one position detection sensor disposed in a movement range of the support table, wherein the automatic adjusting means is configured to control the DC based on a signal transmitted from the position detection sensor.
When the feeding pressure detected by the feeding pressure detecting device is less than a predetermined value by controlling a motor, the support base is moved in a direction approaching the bottom plate and detected by the feeding pressure detecting device. When the sheet supply pressure is higher than a predetermined value, the support table is moved in a direction away from the bottom plate.
6. The paper feed separation device according to 2, 3, 4 or 5. 8. The paper feed separation device according to claim 1, wherein the paper feed pressure detection device uses a strain gauge load cell as the pressure receiving unit.