Note: Descriptions are shown in the official language in which they were submitted.
CA 02490203 2004-12-15
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part patent application which claims
priority to the nonprovisional patent application having Serial No.09/978,266,
which was filed on October 15, 2001, and which claims priority to the
provisional
patent application having Serial No. 60/239,952, which was filed on October
16,
2000.
BACKGROUND OF THE INVENTION
This invention relates principally to a device for measuring the torque
generated by a hydraulic installer when installing an earth anchor into the
ground.
Installers for driving earth anchors, such as through a Kelly bar, into the
ground, have long been available in the art. Usually, such anchors are
provided
to achieve just that, the anchoring of an end of, for example, a cable, or
other
brace, that is designed for stabilizing the installation of a tower, pole, or
other
instrument, or for whatever use anchors may be installed deeply into the
ground,
during application. For example, anchors may also be used for supporting
foundations, or other structures.
An example of an anchor torque controller, that provides a gauging of the
amount of torque generated when installing an anchor into the ground, can be
seen in the assignee's prior patent No. 5,570,577, upon Anchor Torque
Controller for Anchor Installing Machines. The reason for such a regulator, is
exactly as described in the patent, and that is to provide means for
regulating
and limiting, in addition to controlling, the amount of torque generated by a
hydraulic motor, when driving an anchor into the ground, so that it does not
exceed specified forces, that could lead to a fracture of the anchor, when
installed, and failure when implemented.
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The measurement of torque output of hydraulic diggers of the type used
to install auger type (helical plate) anchors, has been a difficult problem
over the
years. A shear pin type of indicator has been used to limit the torque by
shearing calibrated pins, but such an instrument is difficult to use, has
questionable or poor accuracy, and is subject to maintenance problems.
Likewise, electronic devices attached in-line with the installing tool train,
such as
the Kelly bar, wrench tubes, etc., are usually not durable enough to withstand
the
wear and tear of the excessive G forces generated during difficult anchor
installations. Some methods have tried to employ hydraulic supply line
pressure
as a measuring means, but generally have been frustrated by the changing oil
temperature and viscosity which makes the relationship between the supply
pressure and driving torque an unreliable variable, providing usually
indefinite
read-outs, that are quite inaccurate.
SUMMARY OF THE INVENTION
This invention relates generally to earth anchors, and their installation, but
more specifically provides means for accurately measuring the torque generated
by the hydraulic installer when installing an earth anchor into the ground.
The device of this invention is designed to sense the hydraulic fluid
pressure and translate it into a torque output. To avoid the problems of oil
temperature and viscosity changes, the pressure is measured on both the
driving
side and exhaust side of the hydraulic motor, remote to the drive train.
Locating
the electronics portion of the invention remote to the drive train also avoids
the
damaging effects of vibrations from G-forces during the installation.
The proposed design combines the single output of two sensors,
electronically, with appropriate compensation for individual sensor
differences to
compute the differential pressure applied to the hydraulic motor. The
hydraulic
motor manufacturers have established differential pressure as a highly
accurate
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measure of motor torque, when properly calibrated. The proposed invention
consists, typically, of a pair of pressure sensors with appropriate mounting
means, connected by a cable to an electronic read-out similar to a digital
volt
meter. The electronic circuitry of the read-out is designed to provide
excitation to
the sensors, as well as compensating circuitry for variations in sensor
characteristics, along with a means for calibrating the reading to show the
torque
generated on the display. The torque reading is directly related to the
corrected
pressure differential, but is also some multiple of the actual voltage or
current
differential generated by the sensors. The circuitry to generate the
appropriate
multiple and thus calibrate the read-out for a wide variety of motor types is
provided within the read-out device.
This invention incorporates electronic transducers and a digital display
that lets the user accurately read the torque output of the drive motor. It
displays
torque delivered to the anchor shaft directly in torque measurement units, for
example, foot pounds, kilo-Newton-meters, and related measurement units. The
transducers are attached to the fluid supply and return lines of the hydraulic
anchor installer. Based upon the principle of differential pressure, or
pressure
drop across the hydraulic motor, each unit is calibrated to a specific drive
motor.
A typical complete assembly consists of the shown identified components,
but may or may not include a small rectangular solid manifold, but can use
other
means of attaching sensors, to monitor the supply pressure in return lines.
Two
solid-state, strain-gauge sensors, one for the pressure side, and one for the
return line side, individually sense the pressure on these two lines. The
signals
are transmitted to the read-out via a multi-wire cable that remotely connects
to
the display unit. This cable may be disconnected and stored when not in use.
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The sensors are usually mounted in a steel or other case to protect the
strain gauges against impact, fluid leaks or exposure to the weather, oils,
gases,
and the like. Such gauges are capable of adjustment to provide for efficiency
in
accuracy readings from the torque measurement device.
In usage the cable is connected between the digital display package and
the pressure sensors, as provided, and then the electric power source is
actuated to read the torque motor output directly in torque measurement units.
Then, one reads or records the actual anchor installation torque. The pressure
differential, which is sensed, is translated into torque by the circuitry.
It is, therefore, the principal object of this invention to provide for an
electronic torque measuring device to furnish a precise torque output so the
installer knows exactly and continuously the amount of force being generated
to
drive an anchor into the ground.
Another object of this invention is to provide a compact unit for an
electronic torque transducer and display means, which furnishes very accurate
torque readout during installation of an anchor into the ground.
A further object of this invention is to provide for a very compact electronic
device for determining precisely the torque output of an anchor installer, and
which can be very easily connected to a portion of the hydraulic installer
rather
promptly during usage.
A further object of this invention is to provide a compact unit that produces
accurate torque information, in an electronic digital format, that can be
electronically stored and later retrieved for display or transfer to modern
computer work stations.
These and other objects may become more apparent to those skilled in
the art upon reviewing the summary of the invention as provided herein, and
upon undertaking a study of the description of its preferred embodiment, in
view
of the drawings.
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BRIEF DESCRIPTION OF THE DRAWINGS
In referring to the drawings, FIG. 1 is an isometric view of the electronic
read digital display unit that translates the measured torque into a digital
readout
of the hydraulic pressure differential output of the anchor installer, showing
the
pressure sensor cable and computer data connectors;
FIG. 2 is an isometric view of the same electronic read-out device,
showing its display, and optional power switch;
FIG. 3 is a front view of the hydraulic installer monitoring device which
measures the high and low fluid pressure by the strain-gage sensors which
provide data to the electronic read-out for determination of the amount of
torque
experienced during driving of the anchor;
FIG. 4 is a side view of the hydraulic sensors, with a part of the side guard
being removed to expose the hydraulic pressure sensors;
FIG. 5 is a block diagram of the circuit logic of the invention; and
FIG. 6 is a main torque-traks of sub-assembly for this invention;
FIG. 7 is the main circuit board assembly for the device shown in FIG. 6;
and
FIG. 8 shows the remote torque-trak sub-assembly for this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In referring to FIG. 1 of the drawings, the invention, basically comprising
an electronic torque transducer and display unit, as at 1, is readily
disclosed. As
can be seen, the invention includes the unit 2 itself, having its various
cabling
connectors 3, the sensors 4 (see FIG. 4) and the electronic read-out 5 that
provides information relevant to the installer, as to when the proper torque
is
being applied when driving an earth anchor into the ground.
FIG. 2 discloses the unit 2 incorporating its covering means, so that the
device, when used out in the field, may be resistant to occasional abuse that
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may occur such as through dropping, bumping, of the entire sensitive
instrument
package, when employed for detecting, rather precisely, the amount of torque
experienced. The current design of the main unit for this invention is
intended to
be dash board mounted, on the utility digger truck. While this device is not
necessarily intended for portable usage, it could be, and every effort should
be
made not to tip or impact the unit. In addition, this device is connected
through
the vehicle; it is intended to be hardwired to the vehicles 12 Volt DC power
supply. Battery operation is not necessary to the device, but in an
alternative, the
units may be battery powered, for more portable usage. An optional toggle
switch 5A can be used to disconnect the electrical power source when the unit
is
inactive, thus conserving electrical power.
FIG. 3 and 4 disclose the hydraulic installer monitoring device generally at
4, and which includes a pair of hydraulic fluid measuring sensors, which
include
a high pressure transducer 6 and a low pressure transducer 7, which
effectively
measure the high and low fluid pressures during operation of the installer,
and
which cooperates with the electronic circuitry contained within the transducer
and
display unit 1, to determine a pressure differential as applied to the
hydraulic
motor. There are finro solid-state, strain-gage sensors, one for the fluid
pressure
line side, and the other for the return hydraulic fluid line side, which
individually
sense the pressure on the two fines, and then determine a read out as to the
amount of pressure being applied at these differentials.
As can also be seen in FIG.3, there are fittings to either side of the
hydraulic installer monitoring device 4, each of the fittings 4A and 4B
provided for
connecting within the hydraulic supply and return lines to allow access of the
transducers and gages 6 and 7, respectively, to measure the fluid pressure in
both of said lines. Similar fittings are provided on the back side of the
device 4,
to provide a flow through of the hydraulic fluid in both the supply and return
lines.
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FIG. 5 discloses a block diagram of the circuit logic of this particular
invention. Basically, the primary purpose of the circuit is to take the
electrical
output from two individual sensors, and determine their electrical difference,
so
that the amount of torque generated can be calibrated and displayed. This
circuit accomplishes this task by utilizing passive components, without
amplifiers,
to avoid much of the drift and temperature problems inherent in amplifying
these
types of signals from components. On the other hand, it is just as likely that
the
unit may use active electronic elements, such as amplifiers and
microprocessors,
in its processing of measurements of generated torque. Generally, this
circuitry
works with the use of the two transducers, the high pressure transducer 6, and
the low pressure transducer 7, which are connected, respectively, for
detecting
pressure at the hydraulic source that is used for driving the installer, and
for also
measuring the low pressure in the hydraulic return line, operating with the
same
installer. As an example of the application of the components in the unit,
such
transducers may have a 0.5 volt to 4.5 volt output range, or related voltage
ranges, with the current output transducers having an amperage measuring
means from 0 mil-amps to 20 mil-amps, and 4 mil-amps to 20 mil-amps in
current measurement. This is just an example. The circuit shown is tailored to
work well with the 0.5 volt to 4.5 volt transducers, provided with a regulated
source of 5.0 volts. Through these transducers, the pressure is measured,
converted to current, providing an amperage output that can be processed by
the
circuitry of this invention.
A double throw switch, as at 8, connects to an electrical power source, as
noted. The charge is conducted to a regulator 10, to supply the 5 volts needed
for the circuit and pressure transducers, and simultaneously connects a second
electrical power source, as at 11, to provide the power for a panel meter 12
that
furnishes a display.
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In describing the unit as shown in the circuitry of FIG. 5, these transducer
outputs may be conducted through various resistances, to conduct the charge to
a kilo-ohm potentiometer, which may be used to zero the measurement when the
pressures are equal into the device. In addition, parallel conductive paths is
provided for the kilo-ohm resistors, that are furnished in series with the
potentiometer, and are used to adjust the differential signal to a level
suitable for
display. In this case, for example, a mil-volt signature corresponds to foot
pounds
of torque, with proper calibration and the correct pressure transducers.
With only slight modification of resistor and potentiometer values, the
range can be adjusted to allow measurement of lesser or greater pressures. In
addition, the panel meter is not essential since the circuit also permits the
use of
a multi-meter or other measurement device in which case the second electrical
power source is then included in the meter.
Although a number of variations of this circuit are possible to
accommodate various read-out devices and pressure transducer types, the
common characteristic is an electric subtraction of the two transducer
signals.
The circuit shown here uses a voltage subtraction technique, but can be
modified
for current output pressure transducers by using a current subtraction.
FIG. 6 shows the main torque-trak sub-assembly for this invention. It
includes a main enclosure 13, which incorporates various pin connectors, as at
14, for use for providing electrical connection with the circuitry provided
upon the
main circuit board assembly 15, as can be noted. An enclosure lid sub-assembly
16 furnishes sealed closure for the unit. The enclosure 16 includes a viewing
window 17, through which the various readings, during usage of this device,
can
be observed.
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FIG. 7 shows the main circuit board assembly 15, for this invention. It
includes the circuit board 18, a 200 volt, more or less, 10 OF compacitor 19,
and
a DC-DC converter 20. In addition, a 35 volt 100 OF compacitor 21 also is
employed in the operations of this assembly.
The embodiment shown in FIG. 8 discloses the remote enclosure housing
22, which has its pin connectors 23 provided therein, for electrical
connection to
the remote circuit board 24, as can be noted. An enclosure lid 25 for the sub-
assembly is also provided, for furnishing a sealed closure to the housing, and
the
lid further includes its viewing aperture 26 through which readings can be
determined from the LED readouts provided upon the circuit board assembly 24.
Further advantages of this invention include:
a means of remotely reading the torque output of hydraulic digger motors
commonly used to install earth anchoring devices, thus enabling the installer
to
realize immediately the quality of the anchor installation, such as potential
pull
out strength, proper depth of earth penetration, and whether the installing
system
is in danger of over-torque failure;
a hydraulic/electronic device which can electro-mechanically measure with
high accuracy, the hydraulic pressure drop across a hydraulic motor and
provide
circuitry to vary the resulting electronic voltage or current output of the
sensor
means to display a linear multiple of that signal so that the readout requires
no
further interpretation;
the device as previously described above, with an electronic means for
recording the output so that actual installing information such as time and
applied torque are preserved without the need for manual recording;
a device which provides a low cost means of measuring differential
pressures using two single sensors rather than more complex, expensive, and
range-limited, integrated differential devices.
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Variations or modifications to the subject matter of this invention may
occur to those skilled in the art upon reviewing the disclosure as provided
herein.
Such variations, if within the scope of this development, are intended to be
encompassed within the invention as described herein. The description of the
preferred embodiment, as furnished herein, is done so for illustrative
purposes
only.
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