U.S. patent application number 13/923766 was filed with the patent office on 2013-12-26 for weighing utensil.
The applicant listed for this patent is Mettler-Toledo AG. Invention is credited to Alice Buchmann, Sandra Ehrbar, Michalis Meyer.
Application Number | 20130340882 13/923766 |
Document ID | / |
Family ID | 46319047 |
Filed Date | 2013-12-26 |
United States Patent
Application |
20130340882 |
Kind Code |
A1 |
Ehrbar; Sandra ; et
al. |
December 26, 2013 |
WEIGHING UTENSIL
Abstract
A utensil (1) for weighing a sample (6) has fill (2) and
discharge (3) positions. The utensil has a receptacle (4) with an
attached neck (5). An outside surface (7) of the receptacle has a
seating surface (9) that defines a plane, as well as a fill opening
(13), through which the sample is placed when the utensil is in the
fill position. A passage opening (15) and a discharge opening (14),
at the ends of the neck, allow sample flow from the receptacle
through and out of the neck when in the discharge position, with
flow into the neck occurring between the fill and discharge
positions. The neck has at least one support contact point in the
plane of the seating surface, so that the receptacle rests on both
the seating surface and the at least one support contact point when
in the fill position.
Inventors: |
Ehrbar; Sandra; (Gutenswil,
CH) ; Buchmann; Alice; (Hinwil, CH) ; Meyer;
Michalis; (Islisberg, CH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Mettler-Toledo AG |
Greifensee |
|
CH |
|
|
Family ID: |
46319047 |
Appl. No.: |
13/923766 |
Filed: |
June 21, 2013 |
Current U.S.
Class: |
141/1 ;
141/83 |
Current CPC
Class: |
G01G 23/00 20130101;
B65B 1/32 20130101; B67C 11/02 20130101 |
Class at
Publication: |
141/1 ;
141/83 |
International
Class: |
B65B 1/32 20060101
B65B001/32 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 21, 2012 |
EP |
12173020.4 |
Claims
1. A utensil for receiving and weighing a sample substance when the
utensil is positioned in a fill position and for discharging the
sample substance into a measuring flask having a flask neck with a
standardized ground glass mouth at an end thereof when the utensil
is positioned in a discharge position, the utensil comprising: a
receptacle with a fill opening and a seating surface provided on an
outside surface thereof, the seating surface defining a plane, and
positioned relative to the fill opening so that the sample
substance is placed into the receptacle while the utensil is in the
fill position, with the utensil resting upon the seating surface;
and a utensil neck, arranged on the receptacle, with a passage
opening at a first end thereof, communicating the receptacle to the
utensil neck and a discharge opening at a second end thereof, the
utensil neck and discharge opening sized and adapted so that, when
the utensil neck is seated into the ground glass mouth in the
discharge position, the discharge opening extends into the flask
neck beyond the ground glass mouth; the utensil neck having at
least one support contact point, located in the plane of the
seating surface so that, in the fill position, the utensil rests on
both the seating surface and the at least one support contact
point.
2. The utensil of claim 1, wherein: the at least one support
contact point comprises a support contact surface defining a plane
in the same plane as the seating surface, so that, in the fill
position, the utensil rests on both the seating surface and the
support contact surface.
3. The utensil of claim 2, wherein: the utensil neck has an axis
that is inclined at an acute angle to the plane of the seating
surface.
4. The utensil of claim 3, wherein: the receptacle and the utensil
neck each have tangential planes at all points of the surface
thereof which are inclined relative to the utensil neck axis at
angles of the same algebraic sign or at an angle of zero
degrees.
5. The utensil of claim 1, wherein: the receptacle has a width that
is significantly larger than wider than a width of the utensil
neck.
6. The utensil of claim 1, wherein: the fill opening has a width
substantially equal to a width of the receptacle.
7. The utensil of claim 1, wherein: the receptacle has an inside
surface comprising a bottom area adapted to receive the sample
substance, the bottom area surrounded by a peripheral surface zone
that inclines away from the bottom area at at least one obtuse
angle.
8. The utensil of claim 7, wherein: the passage opening is
connected to the receptacle a height above the level of the bottom
area, so that, while in the fill position, the substance sample
substance cannot flow out of the receptacle through the neck.
9. The utensil of claim 7, wherein: when in the fill position, the
fill opening projects vertically onto the plane of the seating
surface to essentially overlap the bottom area.
10. The utensil of claim 1, wherein: Along a length thereof, the
utensil neck has at least one conical portion, tapering down at a
rate of 1:10, so that the utensil neck conforms to the standardized
ground-glass mouth when in the discharge position.
11. The utensil of claim 10, wherein: the utensil neck has at least
two conical portions, each having the 1:10 taper and a different
diameter.
12. The utensil of claim 1, wherein: the utensil neck comprises at
least one region of decreasing diameter.
13. The utensil of claim 1, further comprising: a handle adjoining
the receptacle.
14. The utensil of claim 1, wherein: the utensil neck has an axis
that is inclined at an acute angle to the plane of the seating
surface.
15. The utensil of claim 14, wherein: the receptacle and the
utensil neck each have tangential planes at all points of the
surface thereof which are inclined relative to the utensil neck
axis at angles of the same algebraic sign or at an angle of zero
degrees.
16. The utensil of claim 4, wherein: the receptacle has an inside
surface comprising a bottom area adapted to receive the sample
substance, the bottom area surrounded by a peripheral surface zone
that inclines away from the bottom area at at least one obtuse
angle.
17. The utensil of claim 16, wherein: the passage opening is
connected to the receptacle a height above the level of the bottom
area, so that, while in the fill position, the substance sample
substance cannot flow out of the receptacle through the neck.
18. The utensil of claim 16, wherein: when in the fill position,
the fill opening projects vertically onto the plane of the seating
surface to essentially overlap the bottom area.
19. A method for placing a sample substance into a measuring flask,
comprising the steps of: placing the sample substance into a
utensil according to claim 1, with the utensil arranged in the fill
position thereof; and setting the weighing utensil upright in the
discharge position thereof, with the utensil neck in the mouth of
the measuring flask, so that the sample substance flows out into
the measuring flask.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is entitled to benefit of a right of
priority under 35 USC .sctn.119 from European patent application
12173020.4, filed 21 Jun. 2012, the content of which is
incorporated by reference as if fully recited herein.
TECHNICAL FIELD
[0002] The present invention concerns a weighing utensil that
serves to weigh a substance or to transfer a substance into a
volumetric flask or another type of receptacle used in the
laboratory for the preparation of solutions. In the fill position
of the weighing utensil, a substance is put into the latter, and
the weighing utensil with the substance is weighed. In the
discharge position of the weighing utensil, the substance can be
transferred into the volumetric flask.
BACKGROUND
[0003] Typically, weighing utensils of this kind are used in the
laboratory for the preparation of solutions.
[0004] Solutions are typically mixtures of at least one liquid and
at least one solid substance that is dissolved in the at least one
liquid. The concentration of a solution is the quantitative
proportion of the solid substance relative to the at least one
liquid in which it is dissolved. To ensure that a solution contains
an accurate proportion of a dissolved substance, the respective
quantities of the solution and of the substance have to be
accurately measured. In the laboratory, the quantity of a solution
is normally determined volumetrically, while the substance is
weighed. A volume is normally measured by means of a volumetric
flask. A volumetric flask is a specific type of bottle with a wide
body and a long narrow neck. A graduation mark on the neck defines
the given volume, for example 100 milliliters. The volumetric flask
has a stopper which is inserted into the neck. The section of the
neck that is in contact with the stopper is precision-ground and is
referred to as a ground mouth of the flask. The ground mouth and
the stopper together serve to provide a tight seal of the flask
which minimizes the loss of solution for example when the flask is
shaken.
[0005] The quantity of the solid substance, on the other hand, is
determined by weighing, and it is therefore also referred to as the
weighing sample. First, a receptacle is placed on a balance,
whereupon the latter is tared, i.e. reset to zero. Next, the
substance is incrementally added to the receptacle until the
desired weight has been reached. When this so-called weighing-in
process is completed, the receptacle is held over the volumetric
flask and rinsed with the liquid by pressing the latter out of a
squeeze bottle, so that the substance is washed completely into the
volumetric flask. After the substance in its entirety has been
transferred to the volumetric flask and dissolved in the liquid,
and after the liquid has been topped off to the graduation mark and
the mixture has been homogenized, a homogeneous solution has been
obtained as a result.
[0006] Conventionally a paper weighing boat which is made of a
sheet of parchment paper is used as receptacle. The sheet of
parchment paper can be folded into a desired shape. Normally, the
folding produces a receptacle with a bottom and deep sides. Paper
weighing boats are a very handy means for holding and weighing the
substance. Transferring the substance, on the other hand, proves to
be more difficult. Due to the light weight and the pliability of
the paper weighing boat, it takes diligence to manipulate it with
skill and precision. In the process of dumping the substance into
the measuring flask, the weighing boat can easily slip out of one's
hands or be crushed.
[0007] It is also common to use weighing boats of a plastic
material, for example polystyrene. They are available commercially
in rectangular, rhombic or hexagonal shapes with a wide bottom and
low, slanted sides. Due to their flat bottoms, they rest very
securely on a flat surface for the filling and weighing of the
substance. They have the advantage of being pliable, which makes it
possible to channel the flow of the substance when transferring the
latter into the measuring flask. However, like the paper weighing
boats, the plastic boats are so light and soft that the substance
can easily get spilled.
[0008] U.S. Pat. No. 6,179,022 discloses a receptacle in the shape
of a weighing funnel which is made of plastic. Similar weighing
funnels are also known which are made of glass. The weighing funnel
consists of a receptacle with a fill opening for the substance. A
neck with an opening for the discharge of the substance from the
weighing funnel is connected to the receptacle. In one embodiment
of the weighing funnel, the receptacle has a flat surface parallel
to the axis of the neck, which makes it easier to place the
substance in the receptacle. While transferring the substance into
the measuring flask is safer with the weighing funnel than with the
conventional weighing boats, the weighing funnel still has the
disadvantage that it can roll over easily because the flat surface
is not large enough, and/or it can lose its equilibrium because of
the neck. Thus, the stable position of such weighing funnels during
the filling and weighing operation cannot be assured.
[0009] A further disadvantage of the conventional weighing funnel
is its short and narrow neck. Due to the narrow outside diameter of
its neck, the weighing funnel does not sit securely in the neck of
the measuring flask. The weighing funnel will be loose in the
measuring flask. This makes the rinsing of the weighing funnel with
a jet of liquid cumbersome and increases the risk of spills.
[0010] The shortness of the neck of the weighing funnel also leads
to a loss of substance, as the substance flowing out of the
weighing funnel into the measuring flask will come into contact
with the ground surface at the mouth of the flask and a small part
of the substance will necessarily remain there. Thus, substance
particles will be caught between the ground mouth and the stopper
and therefore not get dissolved in the subsequent shaking,
resulting in an incorrect concentration.
[0011] It is critical for the accurate concentration of the
solution that at the end of the procedure the entirety of the
weighed substance is transferred into the liquid. Accordingly, no
substance may remain in the receptacle or between the ground mouth
of the flask and the stopper.
[0012] The present invention therefore has the objective to provide
a weighing utensil which allows the substance to be weighed and
transferred into a measuring flask with a minimal loss and which
makes the handling as convenient and safe as possible.
SUMMARY
[0013] This task is solved with a device and a method having the
characteristics specified in the independent patent claims. Further
advantageous embodiments are described in the dependent claims.
[0014] The invention covers a weighing utensil with a receptacle
and with a neck arranged on the receptacle, wherein in the fill
position of the weighing utensil a substance can be filled into the
receptacle, and in the discharge position of the weighing utensil
the substance inside the receptacle can flow out through the neck.
The receptacle has a flat seating surface arranged on the outside
of the receptacle, and a fill opening through which a substance can
be filled into the receptacle when the weighing utensil is in its
fill position, i.e. the position in which the weighing utensil
rests on its flat seating surface. At a first end of the neck there
is a passage opening through which the substance can flow out of
the receptacle when the utensil is in discharge position, and at a
second end of the neck there is a discharge opening for the
discharge of the substance from the neck when the utensil is in
discharge position. The neck and the receptacle are connected to
each other in such a way that between the fill position and the
discharge position the substance can flow out of the receptacle by
way of the passage opening and through the neck. The neck has at
least one support contact point in the same plane as the seating
surface of the receptacle, so that in the fill position of the
weighing utensil, the latter will rest on the seating surface and
on the at least one support contact point.
[0015] This arrangement is advantageous in that it allows the
weighing utensil to rest securely on a flat surface, for example on
a table or on a balance. Thus, the weighing utensil remains in a
stable condition, supported at the seating surface and the support
contact point, and there is no risk that it could tip over sideways
or to the back. In addition, since the weighing utensil is thus on
a stable footing, the operator has both hands free for the filling
of the weighing utensil. The weighing sample can be an expensive,
dangerous, or even toxic substance. Therefore, care needs to be
taken already in the filling of the weighing utensil in order to
minimize spillage and/or to prevent the substance from getting into
contact with the skin of the operator.
[0016] A weighing utensil according to a particularly preferred
embodiment has not only a support contact point but a support
contact surface on the neck extending in the same plane as the
seating surface of the receptacle. This embodiment has the
advantage that it is even more stable. The support contact surface
on the neck is ideally arranged in such a way that the width of the
discharge opening is reduced as little as possible.
[0017] The seating surface is preferably arranged so that the
longitudinal axis of the neck is inclined at an acute angle to the
plane of the seating surface. With the neck at an acute angle to
the seating surface, the rinsing liquid can reach the inside bottom
of the receptacle more easily when the weighing utensil is in
discharge position. In weighing utensils of the existing state of
the art, the seating surface and the neck are aligned parallel to
each other. This means that in the discharge position the seating
surface of the receptacle is oriented vertically. Due to the small
angle between the bent-over neck of a squeeze bottle and the
receptacle bottom on the inside of the seating surface, the
weighing utensil cannot be rinsed out efficiently. The ideal angle
for effective rinsing is between 20.degree. and 40.degree., so that
the inside bottom of the weighing utensil is sprayed at an angle of
about 60.degree. to 90.degree., which allows a direct, convenient
and efficient flushing of the weighing utensil.
[0018] In an advantageous embodiment of the invention, the
tangential planes at all points of the surface of the weighing
utensil are inclined relative to the axis of the neck at angles of
the same algebraic sign or at an angle of zero degrees. In other
words, the tangential planes at all points of the surface of the
weighing utensil cross the axis of the neck in the same direction
or are parallel to the axis of the neck. Accordingly, the shape of
the weighing utensil is free of projections that would prevent its
release from a single-piece casting mold. This property allows the
weighing utensil to be manufactured by injection molding, using a
mold without transverse slide. Thus, the casting can be taken out
of the mold quickly and easily without subjecting the weighing
utensil to bending. In addition, it makes the manufacturing process
more efficient and thus more economical.
[0019] It is of particular advantage that the receptacle is
significantly wider than the neck. Ideally, the receptacle is twice
as wide as the neck is at its widest diameter. This proportion
promotes a good and comfortable grip on the weighing utensil for
the filling as well as the rinsing.
[0020] It has been found to be beneficial to design the fill
opening with the same width as the receptacle. With the weighing
utensil in fill position, the user thus has a clear space to hold
his implements above the receptacle bottom when placing the
substance into the weighing utensil. In addition, this kind of fill
opening facilitates the rinsing of the weighing utensil in the
discharge position.
[0021] The receptacle has an inside surface which, in an
advantageous embodiment, includes a bottom area where the weighing
substance can be placed. The bottom area is located essentially
opposite the seating surface of the receptacle. The bottom area is
surrounded by a peripheral surface zone that is inclined at obtuse
angles to the bottom area, ideally between 100.degree. and
140.degree.. In this arrangement, it is particularly advantageous
that the receptacle has the shape of a wide and open bowl. Thus,
the weighing utensil can be rinsed easily in the discharge
position. The liquid jet of the squeeze bottle can reach the bottom
area and the peripheral zone without a problem. Also, it is
practically unnecessary to tilt the squeeze bottle in order to aim
the liquid jet directly, i.e. with an incident angle of about
90.degree., at the bottom area and the peripheral zone.
[0022] Furthermore, the receptacle and the passage opening can be
designed so that the threshold of the passage opening is at a
height A above the level of the bottom area. In the fill position
the substance can therefore not flow out of the receptacle through
the neck. This feature is particularly advantageous for liquid
substances as it reduces the risk that substance may get lost in
the change from the fill position to the discharge position.
[0023] In a further embodiment of the weighing utensil, the fill
opening is designed so that the vertical projection of the fill
opening overlaps the bottom area. This feature offers the user an
unobstructed view of his manipulations. In addition, it allows him
to place the substance on the bottom area from above.
[0024] The aforementioned features contribute to limiting the loss
of substance during the filling and weighing operations. Also, when
transferring substance from the weighing utensil to the measuring
flask, there is a risk of losing some of the substance. For
example, portions of the substance that come into contact with the
ground glass surface at the mouth of the flask will not be washed
away by the solution after the stopper has been put in the
flask.
[0025] The discharge opening is therefore preferably at a lower
level than the ground glass area when the weighing utensil is
seated in a measuring flask with a ground neck. Thus the outflowing
substance will not come into contact with the ground glass
surface.
[0026] The neck of the weighing utensil can be shaped conically
and/or cylindrically. There can be one or more sections of
decreasing diameter, i.e. the neck does not need to have a
continuous taper. It can have conical and/or cylindrical
sections.
[0027] According to the German industry standard DIN 12664, the
ground glass mouth of a measuring flask has a 1:10 taper. It is
therefore especially advantageous to design the weighing utensil
with a conical neck that has a taper of 1:10, so that in the
discharge position the neck will conform to the ground glass
surface.
[0028] In a further advantageous embodiment of the invention, the
neck of the weighing utensil has at least two sections with a 1:10
taper. The sections have different diameters and are connected by
more strongly tapered transitions. Due to the transitions, the
length of the neck is limited. A weighing utensil with this kind of
neck can be set into measuring flasks with different mouth sizes.
When the weighing utensil is in discharge position on a wide
measuring flask with a large diameter, the neck of the weighing
utensil does not come into contact with the liquid inside the
measuring flask.
[0029] The weighing utensil can further be equipped with a handle.
The handle is preferably arranged at the receptacle, for example at
the opposite end from the discharge opening.
[0030] Beside the weighing utensil, the scope of the invention
extends to a method according to which a substance is filled into a
weighing utensil that is set up in a fill position, wherein the
weighing utensil is subsequently seated upright in a discharge
position in the opening of a measuring flask so that the substance
flows out into the measuring flask.
[0031] The receptacle can have a fill opening with a rounded
contour at the opposite end from the discharge opening. Such a
design has the advantage of a larger inside surface of the
receptacle and/or a larger bottom area.
[0032] The receptacle can also have a fill opening with a pointed
contour at the opposite end of the discharge opening.
[0033] For pulverous substances, a weighing utensil with a biased
discharge opening is particularly suitable. For liquid substances
on the other hand, a weighing utensil with a discharge opening
perpendicular to the axis of the neck is used.
[0034] The weighing utensil can be made of glass. However,
disposable weighing utensils are made mostly of plastic, typically
of polypropylene, polyethylene and/or polystyrene.
[0035] The loss of substance can also be reduced by making the
weighing utensil of an anti-static material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] The weighing utensil and the method of filling a substance
into a measuring flask are hereinafter described through examples
which are illustrated schematically in the drawings, wherein
identical parts are identified by identical part numbers and
wherein:
[0037] FIG. 1 is a side sectional view of the weighing utensil in
fill position in a drawing plane that contains the axis of the neck
and is perpendicular to the plane of the seating surface of the
receptacle;
[0038] FIG. 2 is a top plan view of the FIG. 1 weighing utensil in
fill position;
[0039] FIG. 3 is a perspective view of the FIG. 1 weighing utensil
in fill position;
[0040] FIG. 4 is a side view of the FIG. 1 weighing utensil in
discharge position, seated in the neck of a measuring flask;
[0041] FIG. 5 shows the FIG. 1 weighing utensil seated in discharge
position in a measuring flask, in the process of being rinsed with
a squeeze bottle; and
[0042] FIG. 6 is a top view of a second embodiment of the weighing
utensil with a handle.
DETAILED DESCRIPTION OF THE DRAWINGS
[0043] FIGS. 1 to 3 show, in side sectional, top plan and
perspective views, a weighing utensil 1 in its fill position 2. The
two main parts of the weighing utensil 1 are made evident, i.e.,
the receptacle 4 and the neck 5. The receptacle 4 has the shape of
a bowl with an inside surface 8 and an outside surface 7. The
outside surface 7 of the receptacle includes a seating surface 9.
The seating surface 9 is flat and serves to put the weighing
utensil on a flat base for example on a table or on a balance. The
inside surface 8 consists of a flat bottom 16 and of a peripheral
zone 17 surrounding the flat bottom 16. In the sectional plane of
FIG. 1, the peripheral zone 17 rises up from the flat bottom 16 at
angles .beta. and .gamma., which are obtuse angles, i.e. larger
than 90.degree.. In this configuration, the flat bottom 16 and the
peripheral zone 17 form an open inside surface 8 of the receptacle.
This facilitates the rinsing out of the substance 6. The bottom is
located essentially at the center of the receptacle 4. It is
essentially flat and can be in parallel alignment with the support
contact surface 9. A weighing sample 6 such as for example a
chemical or biological substance is put by the user into the
receptacle 4. The weighing sample 6 is brought in through a fill
opening 13 and placed on the bottom area 16.
[0044] The receptacle 4 is connected to the neck 5. The latter has
at one end a passage opening 15 through which the weighing
substance 6 can flow out of the receptacle 4 when the weighing
utensil is the discharge position 3. At the other end of the neck
5, there is a discharge opening 14 through which the weighing
substance 6 leaves the weighing utensil 1. The neck 5 has three
conical sections 19 that have a 1:10 taper. This is also the
conicity of the ground-glass surface 22 inside the mouth of the
measuring flask 21. Thus, the neck 5 sits securely against the
ground-glass surface 22 in the opening of the measuring flask 21
which provides a stable support. The plurality of sections 19 of
the neck 5 serve the purpose that the weighing utensil can be used
for measuring flasks with different opening diameters. With the
more strongly tapered transitions 20 between the sections 19, a
larger range of diameters can be covered with a limited length of
the neck 5.
[0045] The receptacle 4 connects to the passage opening 15 of the
neck 5. The axis 12 of the neck 5 is slanted downward towards the
discharge opening at an angle .alpha. relative to the plane of the
seating surface 9. In other words, the axis 12 of the neck 5 and
the seating surface 9 of the receptacle 4 are not parallel to each
other. When the utensil is in the fill position 2, the neck 5 rests
on a support contact surface 10 and contributes to the stability of
the weighing utensil 1. The threshold of the passage opening 15 of
the neck 5 is elevated at a height A above the level of the bottom
area 16. Thus, the weighing substance 6 cannot flow out through the
neck 5 when the utensil is in the fill position 2.
[0046] Directing attention now to FIG. 2, the top plan view shows
that the fill opening 13 has essentially the same width as the
receptacle 4. The bottom area 16 and the peripheral zone 17 appear
in the middle of the fill opening 13. The width E of the bottom
area 16 is approximately half as large as the width B of the fill
opening 13. The size of the fill opening 13 and its centered
position relative to the bottom area 16 show that the user can
place the weighing substance on the bottom area 16 in an easy
manual operation using laboratory implements such as a spoon,
tweezers, a dissecting needle or a spatula.
[0047] The perspective view of FIG. 3 shows a weighing sample 6
that has been placed on the bottom area 16 of the weighing utensil
1.
[0048] FIG. 4a illustrates a weighing utensil 1 in discharge
position 3. The neck of the weighing utensil 1 is seated in the
neck of a measuring flask 21. The taper of the sections 19 of the
neck 5 is equal to the conicity of the ground-glass surface 22,
i.e. 1:10, so that the neck 5 is in form-fitting engagement with
the ground-glass mouth 22 of the flask 21. The discharge opening 14
is at a lower level than the ground-glass surface 22; consequently
the weighing substance 6 flows out into the measuring flask 21
without coming into contact with the ground-glass surface 22.
[0049] FIG. 4b represents an enlarged view of the ground-glass
mouth portion 22 of a measuring flask 21. While the neck 25 of the
measuring flask 21 is cylindrical, the ground-glass portion 22 is
tapered with a conicity of 1:10 in accordance with DIN 12664.
[0050] In a perspective view, FIG. 5 illustrates the FIG. 1
weighing utensil 1 in discharge position 3, seated in the neck of a
measuring flask 21. A weighing substance 6 on the bottom area 16 of
the weighing utensil 1 flows, propelled by its own weight, into the
neck 5 of the weighing utensil 1. A squeeze bottle 24, which stands
to the left of the measuring flask 21, is used to spray a jet of
liquid onto the weighing substance 6. In this way, the inside 8 of
the receptacle and especially the bottom area 16 of the weighing
utensil 1 are rinsed off. The weighing substance 6 attacked by the
spray jet flows with the liquid through the neck 5 of the weighing
utensil 1 into the measuring flask 21. This procedure is carried
out in such a way as to minimize the residues of the weighing
substance 6 remaining in the weighing utensil 1 and to maximize the
amount of weighing substance 6 that flows into the measuring flask
21. As is apparent from this drawing, a bottom area 16 that is
slanted slightly backwards can be rinsed effectively with the
squeeze bottle 24. The liquid jet ideally meets the bottom are 16
of the weighing utensil 1 at an angle of 70.degree. to 90.degree..
The large width B of the fill opening 13 as well as the obtuse
angles .beta. and .gamma. of the peripheral zone 17 allow a good
exposure of the bottom area 16 and the peripheral zone 17 to the
liquid jet and thus ensure that only minimal residues of the
weighing substance 6 remain in the weighing utensil 1.
[0051] As is apparent from FIGS. 1, 2 and 4 showing, respectively,
a sectional view, a top view and a side view, the tangential planes
at all points of the surface of the weighing utensil 1 are inclined
relative to the axis of the neck at angles of the same algebraic
sign. Consequently, the weighing utensil can be manufactured by
injection molding using a single-piece mold, and the casting can be
taken out of the mold without subjecting the weighing utensil to
bending.
[0052] FIG. 6 illustrates a further weighing utensil 1 according to
the invention which has a handle 23. The handle 23 is formed as an
extension of the receptacle 4 at the opposite side of the discharge
opening 14. The handle 23 allows the user to hold the weighing
utensil without covering up the contents with his hand. Thus the
user can keep the weighing substance 6 in view while handling the
weighing utensil 1, for example to move it from the table to the
balance and from the balance to the measuring flask 21.
Furthermore, a large handle 23 can be grasped more comfortably and
reduces the risk of coming into contact with the substance, which
is especially important when handling toxic substances.
[0053] Although the invention has been described through the
presentation of specific examples of embodiments, it will be
evident to the reader that numerous further variant embodiments
could be developed from the teachings of the present invention, for
example by combining the features of the individual examples with
each other and/or by interchanging individual functional units
between the embodiments described herein.
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