Note: Descriptions are shown in the official language in which they were submitted.
CA 02279514 1999-08-02
SCOOP WITH WEIGH SCALE
This invention relates to scoops with weighing
capacity. Scoops generally have attached handles. In
this case, a weighing device such as a load cell
incorporating a strain gauge connects the handle to the
scoop supporting the scoop proper, and a display scale is
built into the handle. The weighing device is calibrated
so that when the scoop is empty it registers zero, and
registers the specific weight of material in the scoop.
Although the invention is described and referred to
specifically as it relates to specific devices,
structures and methods for scoops with handles
incorporating display scales, it will be understood that
the principles of this invention are equally applicable
to similar devices, structures and methods for material
containing and handling and accordingly, it will be
understood that the invention is not limited to such
devices, structures and methods for material containing
and handling.
BACKGROUND OF INVENTION
Generally scoops are used to transfer bulk material
from a storage or holding container to a traditional
weighing scale, where the bulk material is poured out to
be weighed. Often a specific approximate or exact amount
is required, and achieved by hit and miss methods. It is
of practical advantage and convenience to know the amount
in the scoop before pouring.
PRIOR ART
Scoops and the like are ancient. Applicant is not
aware of prior art scoops incorporating means to indicate
content weight.
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It is a principal object of the invention to provide
a scoop having weighing capacity. It is a further
principal object of the invention to provide a scoop
having weighing capacity and a display scale. It is a
further principal object to provide a level indicator for
the scoop. Other objects will be apparent to those
skilled in the art from the following specification,
appended claims and accompanying drawings.
DESCRIPTION OF THE INVENTION
In one broad aspect the invention is directed to a
scoop attached to a handle. The handle comprises load
cell means with strain gauge means. The load cell means
is mounted in the handle and bears the scoop. Preferably
the handle has a projecting neck extending toward the
scoop covering the load cell. The strain gauge is
operatively associated with CPU means, which is
operatively associated with readout display means,
whereby a weight in the scoop is converted to a display
number on the readout display means. Preferably the
scoop is manufactured from PVC (polyvinylchloride),
especially preferred is flex PVC. PVC is approved by
both the USDA (United States Department of Agriculture)
and the FDA (Food and Drug Administration, of the United
States) for use with food and agricultural products. The
scoop is not restricted to these materials, conventional
light metals including alloys, a wide range of
conventional plastics, ceramics, and wood may be used.
Typically there is a control switch assembly operatively
associated with the CPU means, and similarly there are
indicator/annunciator lights operatively associated with
the CPU means. The control switch assembly has a
plurality of switches, typically one switch each for
ON/ZERO, OFF, ACCUMULATE, HOLD and UNITS. The ON/ZERO
switch actuates the CPU means on first actuation, and
setting the display number to zero on second and
subsequent actuations. The OFF switch deactivates the
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CPU means. The ACCUMULATE switch actuates the readout
display when a second or subsequent weight is
placed in the scoop displaying the summed weights as a
display number on the readout display. The HOLD switch
HOLD switch actuates the readout display to display the
previous display number. The UNITS switch changes the
units of weight of the display number, from metric to
avoirdupois, or from avoirdupois to metric. Typically
the indicator/annunciator lights comprise ZERO, HOLD, and
UNITS lights. The ZERO light is lit when the display
number on the readout display is zero, but not otherwise.
The HOLD light is lit when the readout display shows the
previous display number, but not otherwise. One UNIT
light is lit when the display number indicates metric
units, but not otherwise. The other UNIT light is lit
when the display number indicates avoirdupois units, but
not otherwise. A level indictor is preferably
operatively associated with the CPU means. The level
indicator actuates a level registering means, which
registers level when the means is horizontal or at an
angle to the horizontal less than or equal to a
predetermined angle, and does not register level when the
means is at an angle to the horizontal greater than the
predetermined angle. An indicator/annunciator light is
operatively associated with the level registering means.
The light is lit when the level registering means
registers level, and off otherwise.
In a second broad aspect the invention is directed
to a level indicator comprising a conducting base being
part of a electric circuit, and forming a sector of a
generally spherical surface. The base has a conducting
surface, which is typically metal, conveniently the
entire base is a metal plate or sheet. A sidewall
circumjacent the sector extends inward toward the center
of the spherical surface. The sidewall has a
circumferential conducting element spaced apart from and
above the conducting base. This conducting element is
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part of the electric circuit and generally level when the
indicator is level. A round conductor typically a ball
bearing rests and is rollable on the conducting base.
The ball bearing is in the middle of the conducting base
when the base is level, and touches the conducting
element in the sidewall when resting against the
sidewall, whereby the electric circuit is closed.
The electric circuit when open allows an
indicator/annunciator light to light and when closed
switches it off. The spherical surface preferably
subtends an angle of between about 8 and 12° at the
center of the spherical surface, allowing the scoop to
displace up to half the angle before contacting the
sidewall. The level indicator may have a transparent
insulating top wall above and touching the sidewall
spaced apart from and opposed to the conducting base.
Preferably a scoop having an attached handle,
incorporates the level indicator which is associated with
the handle. Preferably the scoop has load cell means
with strain gauge means, said load cell means being
mounted in said handle and bearing said scoop. The level
indicator may be mounted directly on the load cell, or
more preferably on a neck attached or integral with the
handle. When present the neck projects toward the scoop
covering the load cell. The strain gauge is operatively
associated with CPU means, which is operatively
associated with readout display means, whereby a weight
in the scoop is converted to a display number on the
readout display means. Typically there is a control
switch assembly operatively associated with the CPU
means, and similarly there are indicator/annunciator
lights operatively associated with the CPU means. The
control switch assembly has a plurality of switches,
typically one switch each for ON/ZERO, OFF, ACCUMULATE,
HOLD and UNITS. The ON/ZERO switch actuates the CPU
means on first actuation, and setting the display number
to zero on second and subsequent actuations. The OFF
switch deactivates the CPU means. The ACCUMULATE switch
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actuates the readout display when a second or subsequent
weight is placed in the scoop displaying the summed
weights as a display number on the readout display. The
HOLD switch actuates the readout display to display the
previous display number. When HOLD and ACCUMULATE
switches are combined the first actuation actuates the
readout display to display the previous display number,
while the second actuation displays summed weights when a
second or subsequent weight is placed in the scoop. The
UNITS switch changes the units of weight of the display
number, from metric to avoirdupois, or from avoirdupois
to metric. Typically the indicator/annunciator lights
comprise ZERO, HOLD, and UNITS lights. The ZERO light is
lit when the display number on the readout display is
zero, but not otherwise. The HOLD light is lit when the
readout display shows the previous display number, but
not otherwise. One UNIT light is lit when the display
number indicates metric units, but not otherwise. The
other UNIT light is lit when the display number indicates
avoirdupois units, but not otherwise. A level indictor
is preferably operatively associated with the CPU means.
The level indicator actuates a level registering means,
which registers level when the means is horizontal or at
an angle to the horizontal less than or equal to a
predetermined angle, and does not register level when the
means is at an angle to the horizontal greater than the
predetermined angle. An indicator/annunciator light is
operatively associated with the level registering means.
The light is lit when the level registering means
registers level, and off otherwise.
The invention in a third broad aspect is directed to
a method of weighing material, by placing it in a hand
held scoop, where the material displaces a strain gauge
in a load cell in the scoop, the displacement of the
strain gauge is measured, and this displacement is
converted into a weight, which is displayed on a visual
display. Preferably the strain gauge displacement is
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measured as analog, converted to digital using an analog-
digital converter, and displaying the digital weight on
the visual weight display. The method also indicates
when the scoop is not level by closing a circuit when the
scoop level is further than a predetermined angle from
horizontal, the closed circuit switches off an
annunciator/indicator light showing the scoop is level
within the predetermined angle from horizontal.
Preferably the closed circuit also disables the visual
weight display.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 shows a top plan view of an embodiment of the
invention.
Fig. 2 shows a bottom plan view of the embodiment of
Fig. 1.
Fig. 3 shows a side elevational view of the
embodiment of Fig. 1.
Fig. 4 shows a schematic of the circuitry of the
embodiment of Fig. 1.
Fig. 5 shows a side sectional view of a level
indicator of the invention.
Fig. 6 shows a top sectional view of a level
indicator of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention is now illustrated by reference to
preferred embodiments thereof. Numeral 10 indicates the
weigh scoop of the invention. Weigh scoop 10 has scoop
12 connected by load cell 45 incorporating strain gauge
46 to handle 16. Load cell is preferably covered by neck
14, attached to, or more preferably integral with handle
16. Handle 16 has broad end 18 for membrane keyboard 20,
which has display panel 22 for display 24. Keyboard 20
has besides tactile switches 26 to 34, where switch 26 is
ON/ZERO, switch 28 is OFF, switch 30 is ACCUMULATE,
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switch 32 is HOLD, switch 34 is UNITS, and
indicator/annunciator lights 36 to 44, where Light 36
indicates LEVEL, light 38 indicates METRIC (Kg/g) units,
light 40 indicates AVOIRDUPOIS (or IMPERIAL) (Lb/Oz)
light 42 indicates HOLD, light 44 indicates ZERO. The
HOLD/ACCUMULATE switches can be combined into a single
switch, either switch 30 or switch 32. The
indicator/annunciator lights can also be in display panel
22. Strain gauge 46 of load cell 45 measures the weight
in scoop 12 in analog form (stress/strain,
deformation/displacement), which is converted by
Analog/Digital converter in board 48 in handle 16 to
digital signal for the CPU to process to digital readout
on display 24. There is also level switch indicator 50
mounted either directly on load cell 45, or more
preferably on neck 14, when present, and operatively
associated with board 48, to ensure the scoop is held
level to provide for the most accurate weighments. In
the embodiment shown light 36 is on when level and off
when not. 9V battery 52 provides power and excitation
voltage to load cell, CPU, and display. Tactile
switches, CPU, A/D converter, strain gauge load cell, and
battery are all readily available conventional
technology. The scoop can be made of any conventional
materials that suit customer requirements, such as
corrosive environment, or regulatory requirements, such
as those imposed by departments of agriculture and
health. Scoop 12 need not be the same material as handle
16 (and neck 14), as scoop 12 is generally more subject
to regulatory requirement than handle 16. As noted above
pvc, especially flex pvc is preferred, but conventional
light metals, conventional plastics and wood, or even
conventional ceramics can be used in scoop and handle.
Weighing capacity is envisaged between a minimum capacity
of 10 oz (about 300 grams) and a maximum capacity of 160
oz (about 5 kilograms), with graduation steps of 1 to 10
oz, which is felt to be the most convenient range,
although lesser and greater capacities, as well as
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different graduation steps, may be employed as those
skilled in the art appreciate. This can be carried out
routinely by programming the CPU converter with different
parameters. In Fig. 4 is shown a schematic of the
circuitry of the preferred embodiment. CPU and A/D
converter are part of board 48, which is supplied with
power by battery 52 through power lines 54, keyboard 20
is connected by data lines 56 to board 48, as is display
panel 22 by data lines 58. Load cell 46 is connected to
board 48 by paired excitation lines 60, while paired data
lines 62 provide analog output to board 48. Level
indicator 50 is shown in Figs. 5 and 6, with transparent
level top 64, circular sidewall 66 and conductive bottom
wall 68, which forms a segment of a sphere. Inside level
indicator 50 is metal ball bearing 70, as those skilled
in the art appreciate any electrically conductive sphere
will do. Bottom 68 subtends an angle of 8 to 12° at the
center of the sphere of which it is part, to match the
optimal maximum out-of-level condition (4 to 6°) so that
when ball bearing 70 contacts sidewall 66 the scoop is
from 4 to 6° from horizontal. Sidewall 66 has upper and
lower insulating portions 72 and 74 separated by
conductor 76. Conductor 76 is preferably
circumferentially continuous and has conducting connector
78 to board 48. When level indicator 50 is tilted so
ball bearing 70 contacts conductor 76 it closes a circuit
between metal plate 68 and connectar 78 supplying current
to board 48. When this circuit is closed
annunciator/indicator light 36 goes out, and optionally
display 22 is disabled so that there is no weight
reading. Otherwise, when the circuit is open
annunciator/indicator light 36 is on ann display 22 is
enabled. The level indicator is mounted atop neck 14, so
that the position of ball 70 is visible through
transparent top 64, allowing the operator to maneuver the
handle to center the ball within the indicator. Conductor
78 may be formed of one or more wires threaded through
holes in sidewall 64, which are conveniently of copper.
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These wire or wires may be twisted around each other or
braided to form connector 78. Ball bearing 70 is less in
diameter than the height of sidewall 66 to allow free
movement.
In use the ON/ZERO switch is actuated, to activate
the device then the ON/ZERO switch is actuated to set the
scale at zero. The LEVEL switch or indicator indicates
whether the scoop is level (within 4° to 6° of
horizontal) or not, which may be necessary for "legal for
trade" applications and to achieve optimal weighing
results. The scoop is then used to pick up material, the
weight of which is indicated on the display. By
actuating either the UNITS switch, the display will read
in grams or ounces. The HOLD switch is used to indicate
the previous weight, after the scoop is emptied, while
the ACCUMULATE switch accumulates multiple weighments and
provides a grand total of those weighments. HOLD and
ACCUMULATE functions are conventional in the scale art.
They also may be combined into a HOLD/ACCUMULATE switch,
which on first actuation performs as HOLD and on second
actuation behaves as ACCUMULATE. The OFF switch is used
to switch the device off, an adjustable timer is built
into the CPU board 48 to switch the device off after a
predetermined time to lengthen battery life.
As those skilled in the art would realize these
preferred described details and materials and components
can be subjected to substantial variation, modification,
change, alteration, and substitution without affecting or
modifying the function of the described embodiments.
Although embodiments of the invention have been
described above, it is not limited thereto, and it will
be apparent to persons skilled in the art that numerous
modifications and variations form part of the present
invention insofar as they do not depart from the spirit,
nature and scope of the claimed and described invention.
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