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BACKGROUND OF THE INVENTION
1. Field of the Invention
The apparatus and method of the present invention relate generally to molds
for shaping moldable materials and more particularly to a reusable mold
with freestanding walls capable of being formed in any desired shape for
use with edible andd nonedible materials and the like.
2. Description of the Prior Art
It is often desirable to provide a mold for shaping moldable materials in
any desired shape. For example, such molds have proven useful in molding,
baking or freezing edible materials such as cakes, gelatins, custards, ice
creams, casseroles, ground meats, decorative ice shapes, butter or
margarine, etc. Likewise, such molds have been used for nonedible
materials such as ceramic, plaster, clay or plastic objects. Furthermore,
the mold outline has found utility as a design pattern or design tracer
for drawing, sewing, woodworking, or stenciling for spray painting, to
name a few of the numerous examples.
U.S. Pat. No. 2,015,097 issued Sept. 24, 1935 to H.T. Bowman et al.
describing A method and Apparatus For Shaping Edible Products, and U.S.
Pat. No. 3,128,725 issued Apr. 14, 1964 to W. C. Becker et al. for Methods
and Apparatus For Shaping Baking Materials and the Like, describe typical
prior art attempts to develop a formable mold for the uses mentioned
above. These molds are generally not reusable and are designed to be
disposable, being constructed of paper, cardboard or similar nonpermanent
material. Thus the molds tend to react unfavorably to the material to be
molded, which generally is a liquid or moist material. The walls of the
mold may become saturated and break down or warp, causing leakage of the
moldable material through or under the mold. In addition, the mold walls
may absorb the material or impart an undesirable taste or coloring to the
material being molded. It has also been found that such molds may crimp
when bent in particular design configurations, thereby limiting their
usefulness as a universally shapable wall. It has further been found that
difficulty may be experienced in separating the mold wall from the
hardened material, resulting in destruction of the mold or the molded
product, or both.
It has been proposed to use bars, flanges and other support features to
hold the mold wall sections in a vertical position to retain the mold
shape as well as prevent undesired expansion of the molded material, such
as might occur during baking or freezing of an edible product. Such
supports require a base or outer wall to provide structural integrity.
Intricate designs are discouraged since an unwieldy number of support bars
or flanges are required to adequately support the non-freestanding wall.
In addition, such support means to nothing to prevent leakage beneath the
mold wall. Thicker mold wall elements have not provided a satisfactory
solution to the problem inasmuch as such walls do not permit the degree of
flexibility necessary to construct intricate designs.
It has also been proposed to use tabs, with or without an adhesive, located
on the bottom edge of the mold wall for stabilization and sealing. These
tabs prevent intricate designs since the tabs tend to overlap and bunch
when the wall section is bent. In addition, wall section bends may only be
made between tabs, limiting the size and shape of the formed products.
Slits located in a pan base for receiving the tabs have also proved
ineffective. For example, approximately 200 randomly arranged slits would
be necessary in a pan bottom to accommodate a mold capable of producing
only ten designs and would be unnecessarily confusing to the user. In
addition, slits aid in warpage of the pan bottom, allowing gaps between
the pan and the wall sections permitting leakage of the moldable material.
It has been found that, once a slit has been used and the tab removed, the
slit becomes stretched or distended rendering the pan bottom unsuitable
for reuse.
Prior art workers have also suggested design outlines preprinted on a pan
bottom which the user may use as a guide to form the outline of the wall
mold sections. It has been found, however, that such techniques using more
than five designs, even if printed in different colors, prove confusing to
the user and impossible to follow. Hence, the number of designs available
from a particular mold in the past has been severely limited.
SUMMARY OF THE INVENTION
The present invention overcomes the foregoing disadvantages by providing a
reusable mold for shaping moldable materials comprising a flexible
freestanding wall capable of being formed in any desired shape to form the
contour of the product to be molded. The mold walls are constructed of
silicone rubber and aluminum, or similar materials, having the ability to
withstand baking and freezing temperatures. When bent to a design
configuration, the mold will hold its shape during the molding process,
and may be easily returned to its original shape for reuse in other design
configurations. The wall sections are freestanding and require no external
support. The mold may include several interconnecting sections permitting
simplified assembly of the mold and removal from the molded product.
Holding means may also be provided to hold the mold walls tightly against
a base section to prevent leakage of the moldable material. Designs may be
made by molding the wall sections around geometric shapes, patterns,
drawings, or in a freehand manner. Preprinted designs may be provided for
shaping the mold to follow a particular design outline.
The flexible freestanding mold wall section consists generally of a thin
solid or ribbed half-hard or thick dead-soft aluminum wall support strip
which may be encapsulated with a resilient silicone rubber coating.
Covering the aluminum with a resilient material prevents fatigue failure
of the metal as well as adds stability and ease of shaping to the wall
section. The lowermost portion of the wall section may be provided or
trimmed with a sponge silicone rubber edge which forms a seal between the
wall section and a suitable base upon which the section rests to prevent
leakage of the material from within the mold. A resilient clip is affixed
to one end of the wall section at its uppermost surface which engages a
suitable tab located on the uppermost end of an adjoining wall section,
thereby permitting several sections to be joined together, in overlapping
relationship, to form the desired wall length for shaping the wall
contour. Alternately, the wall may be constructed of frictionally hinged
wall sections. In this configuration, the solid or ribbed wall support is
replaced by a plurality of contiguous close ratio hinged joints, which
permit the wall to be bent in the small increments necessary for intricate
designs. Each individual hinge is constructed with a tightly fitting hinge
post, creating a hinge capable of being moved to and retained in a desired
bent position. In certain applications, the friction hinges may be
replaced by pyramid type spring lock joints. In this configuration, each
joint comprises a pair of convoluted meshed surfaces providing a discrete
number of locked angular positions for the joint. The meshed surfaces may
be urged together by springs or the like.
The mold contour may be formed freehand or by following a suitable design
outline. In one embodiment, wall sections are interconnected and shaped by
hand to follow the design outline. The completed mold then may be placed
on a suitable base, such as an aluminum sheet pan, and filled with the
material to be molded. Since the wall sections are temperature resistant,
the mold may be used for baking or freezing.
In another embodiment, the design outline sheet is placed upon a suitable
base, such as an aluminum sheet pan, and covered with a transparent heat
resistant overlay, such as a heat resistant plastic. The wall sections are
then interconnected and shaped to follow the design outline contour. The
material to be molded may then be poured directly into the mold, the heat
resistant transparent overlay forming a leakproof seal with the sponge
silicone rubber edge of the wall section. In still another embodiment, the
formed wall sections are placed atop an aluminum base having a plurality
of parallel slots formed therein. An aluminum foil sheet is interspersed
between joined wall sections and the base to form an impervious layer. A
number of spaced spring loaded clips engage the upper edge of the joined
wall sections, with the lower end of each clip piercing the aluminum foil
sheet and engaging one of the parallel slots. The clip is locked into
place thereby firmly holding the joined wall sections against the aluminum
foil sheet and base to prevent leakage of the mold material beneath the
wall of the mold.
In another embodiment, the joined wall sections surmount an impervious
base, such as an aluminum sheet pan, and are pressed firmly against the
base surface by a wire pressure grid or rack. The pressure grid may be
comprised of a plurality of parallel spaced rod-like members attached at
their ends of a rectangular frame. A member of spring-assisted pressure
grid clips or other fasteners, such as connecting nuts and bolts, connect
the frame and base together to provide a downward pressure, thereby
sandwiching the joined wall sections between the pressure grid and the
base to form a complete seal between the lower edge of the joined wall
sections and the base.
In another embodiment, the lower edge of each wall section is slotted to
approximately one-half the depth of the wall. When the wall sections have
been joined together in the desired shape, the joined wall sections are
positioned with the slit portion facing upwardly, and covered with a heat
transparent plastic sheet. A blunt object is then used to force the
plastic sheet into the slit in the wall edge. This procedure of tucking
the plastic into the slit is followed around the wall edge, producing a
sealed bottom for the mold. The entire mold is returned to the upright
position and filled with the desired moldable material. After use, the
heat resistant transparent plastic sheet may be easily removed from the
slits, and stored with the disassembled wall sections for future use. A
specialized plastic tool may be included to perform the tucking function,
comprising a handle, a blunt rounded end, and a stop portion consisting of
a cross arm attached perpendicularly to the handle to limit the distance
the tool may be inserted into the wall slit. Alternatively, the wall may
be constructed with a plurality of parallel resilient ribs spaced along
the length of the outside surface of each wall section, each rib being
hinged at its upper edge to snugly hold a tucked plastic sheet between the
rib and the outer wall surface to form a leakproof base for the mold.
Small tabs projecting from the outer surface of the wall between the wall
and the resilient ribs may be provided to increase the frictional
engagement with the tucked sheet. This construction has been found to be
particularly useful for mold contours having sharply bent areas to insure
effortless attachment of the tucked sheet.
In another embodiment, the lower outside surface of the wall sections may
be provided with a plurality of parallel spaced silicon rubber ribs. The
bottom of each rib is flush with the lowermost edge of the wall sections
and contains a centrally located aperture for receiving a conventional
round top tack. The joined wall sections configured in the desired shape
are placed with the bottommost edge of the wall facing up, and a heat
resistant plastic sheet placed over the joined wall sections. Round top
tacks are then pushed through the heat resistant plastic sheet into the
aperture located in the lowermost surface of each rib, thereby providing a
leakproof bottom for the mold. The entire mold is then inverted and is
ready for use.
In another embodiment, each wall section is substantially T-shaped in cross
section, the wall having leg sections extending from the lower edge of the
mold. The mold made up of such T-shaped wall sections is formed into the
desired design shape and inverted, with the legs of the mold facing
upwardly. A sheet of conventional aluminum foil is placed over the lower
edge of the mold, with the edge of the foil extending beyond the edge of
the mold. The foil sheet is then pressed into contact with the inner and
outer legs of the wall section. The entire mold is inverted and the excess
foil bunched around the outside of the mold section. Beginning at the
center of the mold, the foil sheet is smoothed toward the inner surface of
the wall sections, until the sheet is substantially smooth. Excess foil
remaining on the inside of the mold may be bunched around the inner mold
leg. The aluminum foil sheet bunched around the projecting legs of the
wall sections thus forms a tight seal around the inner and outer edges of
the base of the wall sections. After use, the wall sections may be
disassembled and the aluminum foil sheet reused or discarded.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a perspective view of a first embodiment of the mold of the
present invention with one reusable freestanding wall section shaped to
form part of the outline contour.
FIG. 1B is the mold of FIG. 1A with a second free-standing wall section
added to follow the outline contour of part of the particular design
pattern.
FIG. 1C is the completed mold of FIG. 1A with all freestanding wall
sections joined to follow the outline contour of the particular design
pattern.
FIG. 2 is a cutaway perspective view of a reusable freestanding wall
section of the mold of the present invention.
FIG. 3 is a cutaway perspective view of a second embodiment of the present
invention.
FIG. 4 is a perspective view of a wall-to-base attaching clip used with the
embodiment of FIG. 3.
FIG. 5 is a perspective view of a third embodiment of the present
invention.
FIG. 6 is a perspective view of a pressure grid clip used with the
embodiment of FIG. 5.
FIG. 7 is a cutaway perspective view of a flexible rib freestanding wall
section.
FIG. 8 is a fragmentary perspective view of an inverted single freestanding
wall section used with a fourth embodiment of the mold of the present
invention showing the heat resistant transparent plastic sheet tucked into
the wall section slit.
FIG. 9 is a fragmentary perspective view of an inverted single wall section
of a fifth embodiment of the mold of the present invention showing
attachment of the heat resistant plastic sheet to the wall section ribs.
FIG. 10 is a perspective view of a sixth embodiment of the mold of the
present invention.
FIG. 11 is a fragmentary cross sectional view of the mold of FIG. 10
showing the crushed foil seals.
FIG. 12A is an inverted fragmentary cutaway perspective view of a
hinged-rib freestanding wall section.
FIG. 12B is a cross sectional view through the wall section of FIG. 12A.
FIG. 13 is an exploded fragmentary perspective view of a frictionally
hinged freestanding wall section.
FIG. 14 is an exploded fragmentary perspective view of a lock joint
freestanding wall section.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The general configuration of a single formable wall section 1 is
illustrated in FIG. 2. Each wall section 1 comprises a thin flexible
strip-like aluminum wall support 2 encapsulated with a thin resilient
coating 3, which completely covers wall support 2. Wall support 2 may
consist of half-hard aluminum, 0.016 inches or less in thickness.
Encapsulant 3 may be solid silicone rubber, or a similar resilient
material While silicone rubber covered aluminum is the preferred
construction, other types of covered wall supports, such as aluminum
covered with Teflon or coated canvas, will also serve. It has been found
that covering the metal wall support with a material on both sides, of
approximately the same thickness as the metal itself, prevents fatigure
failure by limiting the degree to which the metal may be bent. In
addition, the covering adds stability to the wall section. Alternatively,
a thicker 0.048 inch or less dead-soft aluminum wall support 2 can be used
in place of the half-hard aluminum support. In this configuration,
encapsulant 3 may be omitted if desired.
A resilient clip 4 is secured to the wall support 2 at the upper end of the
wall section by rivets 5 or similar fasteners. Clip 4 may be constructed
of metal, plastic or similar spring-like material. Clip 4 may also be
molded into resilient coating 3 or formed as an integral part of wall
support 2. It is preferred that the clips be of a harder metal or temper
than the wall support material in order to prevent breakage of the clip
with repeated use. At the opposite end of the wall section 1 the wall
support protrudes for a short distance and is bent at approximately a
45.degree. angle to form a tab 6. As will be described, tab 6 operates in
conjunction with clip 4 to join adjacent wall sections to form the
complete mold.
A strip of sponge-like material 7, which may consist of a sponge silicone
rubber, is secured to the lower edge of wall section 1 to aid in sealing
the wall section to prevent leakage thereunder, as will be described
hereinafter. A fill line 8 consisting of a ridge, groove or painted line,
running the length of the wall sections, may also be provided to enable
the user to fill the completed mold to the proper level with the material
to be molded.
While shown formed in a U-shaped contour, it will be understood that the
wall section 1 of FIG. 2 may be shaped or reshaped to any desired
configuration, and will retain the desired configuration indefinitely.
FIG. 13 and FIG. 14 illustrate alternative constructions for wall support
2. In FIG. 13 wall support 2 comprises a plurality of closely spaced
identical metal or plastic hinge joints, one of which is shown detached
from an adjacent hinge joint at 83. Each hinge member 83 is secured to an
adjacent hinge member by pin 84, whose diameter is slightly larger than
the inner diameter of apertures 85 and 86 to provide a snug friction fit,
thus enabling wall section 2 to retain a particular bent configuration.
End hinge joint 87 lacks the central aperture 86 of hinge joints 83 to
provide a smooth edge 88 for forming the end of wall section 2. It will be
understood that the friction hinge embodiment of FIG. 13 may be provided
with a suitable coating 3, on one or both sides of the wall, and
sponge-like strip 7 as described hereinbefore in connection with the
embodiment of FIG. 2. It has been found that the hinged construction of
FIG. 13 finds particular utility in applications where sharp bends or
intricate designs are required, or in environments where fatigue failure
of a solid metal wall support may be a problem.
FIG. 14 illustrates a further alternative wall support 2 construction
composed of a plurality of interlocking metal or plastic lock joints, one
of which is shown detached from an adjacent lock joint at 89. Each joint
89 comprises a pair of convoluted surfaces 90 and 91 having a plurality of
pyramid-shaped teeth, one of which is shown at 92, surface 90 meshing with
surface 91 of adjacent joint 89a and surface 91 meshing with surface 90 of
joint 89b. Adjacent lock joints are hinged by means of an upstanding pin
93 projecting from the bottom of each joint which engages a matching pin
engaging aperture 94 projecting from the lower edge of an adjacent joint.
Adjacent joints are connected together and the mating surfaces 90 and 91
thereof urged together by connecting post 95 which passes through
centrally located apertures 96 and 97 in surfaces 90 and 91, respectively.
Spring 98 and restraining washer 99 may be included on post 95 adjacent
aperture 96 to urge surfaces 90 and 91 into meshed contact. End 95 of a
post 95 may be flared (not shown) adjacent the lower portion of aperture
97 to maintain spring 98 in partial compression, as shown generally at
100.
In operation, teeth 92 of mating surface 91 engage the spaces between teeth
92 of mating surface 90, while teeth 92 of mating surface 90 engage the
spaces between teeth 92 of mating surface 91. When wall 2 is bent to a
desired design configuration surface 90 and 91 are rotated with respect to
each other such that the pyramid-shaped teeth 92 of one ride along and
over the teeth of the other. When wall 2 has been bent to the new
position, teeth 92 of surface 91 will once again engage the spaces between
teeth 92 of mating surface 90, and vice versa, to retain wall 2 in the new
position. It will be understood that spring 98 is only partially
compressed to allow for further compression as mating surface 90 is urged
upwardly as teeth 92 of surface 90 travel over teeth 92 of surface 91. It
will be further understood that the lock joint wall of FIG. 14 may be
provided with a suitable coating 3, on one or both sides of the wall, and
sponge-like strip 7 as described hereinbefore in connection with the
embodiment of FIG. 2. End joint 89a may also be provided with a smooth
edge 101 for forming the end of wall section 2.
FIG. 1A-FIG. 1C illustrate the sequence of events used to form a complete
mold using a plurality of the formable wall sections 1 of FIG. 2.
A suitable design pattern 9 is placed atop a base 10. Base 10 may be a
conventional aluminum sheet pan formed of 1/32 inch aluminum sheet or
similar material. Design pattern 9 comprises a sheet of 65 pound cover
stock paper or similar flexible material bearing the preprinted outline 11
having the desired finished contour of the mold. While for purposes of an
exemplary showing, the outline of a train has been selected, it will be
understood that an outline having any shape may be used. For example, a
design pattern may be selected corresponding to a particular holiday, such
as a shamrock for St. Patrick's Day, A Christmas tree for Christmas, or a
turkey for Thanksgiving Day. In addition, standard shaped outlines such as
squares, rectangles, circles, hearts, numerals, letters, etc. may be
employed. In addition, blank sheets may be provided so that additional
designs may be drawn by the user. Several different designs may be
provided on one side of the design pattern and distinguished by
contrasting colors or designs may be provided on both sides of a design
pattern sheet. The pattern sheet may also be constructed as a stencil,
whereby the desired design outline may be transferred onto an underlying
surface, such as base 10, by means of perforations in the pattern sheet
following the design outline. A suitable marker, such as a pen or pencil,
may be inserted through the perforations to transfer the design outline
onto the underlying surface. In addition, the design patterns may be made
disposable or reusable, depending upon the type of material employed, for
example, paper, plastic, etc. Furthermore, decorating suggestions, (not
shown) such as life-size representations of a finished decorated product,
may be provided within the design outline for the convenience of the user.
Suggested recipes or instructions for using the design pattern may also be
printed on the design pattern, in any convenient location, such as the
area depicted 12 in FIG. 1A. While it is preferred that individual design
pattern sheets be used, it is also within the scope of the present
invention to provide a plurality of sheets bound together to form a
booklet as shown in FIG. 1A, from which the user may select as desired.
While the mold of the present invention may be constructed directly atop a
suitable design pattern 9, an additional intermediate layer (not shown),
such as a heat resistant transparent sheet or other transparent film, may
be provided between the mold and the design pattern to prevent leakage or
sticking of the mold material, depending upon the particular mold material
employed. This intermediate sheet may be removed prior to subsequent
processing steps, or left in place with the completed molded product.
Turning to FIG. 1A, a single wall section 1a is placed atop the desired
design pattern 9, with the sponge rubber edge 7 of the wall section
resting against the upper surface of the design pattern 9, and bent to
follow the outline contour of the particular design. For example, wall
section 1a has been bent at locations 13-17 to follow the outline of the
train design 11 of FIG. 1A. In addition, portion 18 of wall section 1a has
been shaped in a circular contour to follow the outline of the wheel
portion 19 of train design 11.
In FIG. 1B a second wall section 1b has been added atop design pattern 9
and shaped to follow the continuing contour of the train design. The upper
edge of the end of wall section 1b containing tab 6 is inserted beneath
tab 4 of wall section 1a with tab 6 facing outwardly. Wall sections 1a and
1b are then adjusted so that their lower edges make intimate contact with
the upper surface of design pattern 9 and so that the end of wall section
1b containing tab 6 protrudes slightly beyond clip 4 of wall section 1a.
Wall sections 1a and 1b are thus joined in overlapping relationship, with
resilient clip 4 holding both sections firmly in place. Tab 6 of wall
section 1b prevents wall section 1b from becoming disengaged from clip 4
of wall section 1a.
In FIG. 1C the mold is completed by shaping two additional wall sections 1c
and 1d to follow the outline contour of design pattern 9. It will be
understood that wall section 1c is joined to wall section 1b, wall section
1c is joined to wall section 1d, and wall section 1d is joined to wall
section 1a in a manner similar to that described hereinbefore for the
joinder between wall sections 1a and 1b. Since designs may be of various
sizes, it may be found that the entire length of a particular wall section
2 is not needed to complete the mold contour. When this situation is found
to occur, the adjoining wall sections are overlapped with the unneeded
portion of the wall section left exposed on the outer surface of the
completed mold outline. In particular instances, it may be necessary to
bend the unneeded portion away from the outside surface of the mold to
prevent interference with adjacent portions of the mold. If desired,
designs can be provided that require a given number of complete wall
sections, resulting in no overlap of the final wall section used.
The completed mold outline shown generally at 20 in FIG. 1C may be left
atop design pattern 9, or removed to another suitable base section, such
as an aluminum sheet pan. The inside surface of the mold may then be
coated with a suitable lubricant, if necessary, and the mold slowly filled
with the desired material to be molded 21 to the mold fill line 8, or as
required. When the molded material has hardened to the desired
consistency, the individual wall sections may be stripped from the molded
product by disengaging the clip 4 between two adjacent sections, and
slowly peeling the joined sections in one continuous strip from the
contour of the molded product. Thereafter, the molded product may be
removed from the design pattern 9 and used as required. The joined wall
sections may be disconnected by slipping the tab end of each wall section
from its associated clip 4. The individual wall sections may then be
cleaned, straightened, and reused in other configurations.
While for purposes of an exemplary showing the individual wall sections
have been described as being joined by a resilient clip 4, it will be
understood that any other suitable fastening means may be employed, such
as snaps, resilient fasteners, slots and tabs, etc. In addition, while the
mold outline has been described for use in shaping moldable products, it
will be understood that the outline may also be used as a stencil for
spray painting, as a pattern or tracer for drawing, sewing, woodwork, or
the like.
In certain situations, moldable materials of high viscosity may show a
tendency to leak beneath the lower surface of the completed mold. Hence,
it has been found desirable to include means for producing a downward
pressure on the upper surface of the mold wall sections to insure a
complete seal between the sponge rubber lower edge of the wall sections
and the upper surface of the base upon which the mold rests.
In FIG. 3, a plurality of spring loaded clips 22, one of which is shown in
more detail in FIG. 4, urge joined wall sections 1a-1d downwardly to
produce a leakproof seal between the lower edge of the wall sections and
the upper surface of the supporting base. When the completed mold outline
20 of FIG. 1C has been shaped to the desired contour, it is placed atop
slotted aluminum base 23 which is surmounted by an impervious sheet 24,
shown partially cutaway in FIG. 3. Slotted base 23 comprises a thin sheet
of aluminum or other suitable material containing a plurality of parallel
spaced slots, one of which is shown in FIG. 3 at 25. For example, base 23
may comprise a conventional aluminum sheet pan with 1/16 inch wide slots
spaced 1/2 inch apart. In addition, to improve the rigidity of base 23,
some of slots 25 may extend the entire length of base 23, such as slot 26,
for example, while other slots, such as that shown at 27, may extend less
than the entire length of base 23.
As is best shown in FIG. 4, attaching clip 22 comprises a clamp portion 28,
a post 29, and a compression spring 30. Clamp 28 includes a pair of
horizontal, parallel spaced webs 31 and 32, each web containing a
centrally located aperture 33 and 34 respectively. Webs 31 and 32 are
joined by a vertical member 35. Clamp 22 also includes a downwardly
depending lip 36 parallel to and spaced from connecting member 35.
Downwardly depending lip 36 is spaced a distance from connecting member 35
slightly greater than the thickness of a formable wall section 1. Post 29
comprises an L-shaped rod-like pin extending through apertures 33 and 34,
with the leg portion 37 of post 29 underlying lower web 32. The uppermost
end of post 29 is flattened, as at 40, to provide a surface which may be
easily grasped by the fingers. A compression spring 30 is wrapped about
the shank of post 29 between webs 31 and 32. The lowermost portion of
spring 30 is enlarged slightly to prevent its passage through aperture 34,
so that the spring rests upon the upper surface of web 32. The uppermost
end of spring 30 is restrained by a pair of flanges 41 extending outwardly
from the shank of post 29. Hence, when the flattened portion 40 of post 29
is depressed, leg 39 will be separated from the lower surface of web 32 by
a distance at least equal to the thickness of slotted aluminum base 23.
When the pressure on post 29 is released, the post will be urged upwardly
by compression spring 30, returning to its original position. It will be
understood that post 40 may also be rotated to lock the post in place, as
will be described hereinafter.
In operation, the mold wall sections 1 are joined and shaped into the
desired contour as described hereintofore in connection with FIG. 1A-FIG.
1C. A sheet of conventional aluminum foil 24 or other impervious material,
is placed atop slotted aluminum base 23. The upper surface of sheet 24 may
be smoothed across base 23 to expose the location of slots 25, which will
be indicated by impressions in sheet 24. The mold outline is then placed
atop sheet 24 so that its outline lies within the boundaries of sheet 24
and base 23. Clips 22 are attached to the mold such that the wall section
lies between connecting member 35 and downwardly depending lip 36 of the
claim portion 28 of clip 22. Each clip 22 is then lowered until it rests
upon the upper edge of the mold sections 1. Clips 22 are oriented such
that the post 29 lies on the outside surface of the wall sections 1. Each
clip 22 is moved along the wall so that leg portion 39 of post 29 is lying
approximately above a slot 25. It will be observed that it will not be
necessary to move attaching clips 22 more than approximately 1/2 inch to
locate a slot 25. Post 29 may be rotated by grasping flattened portion 40
and twisting, in order to align leg 39 with a slot 25. Post 29 is then
depressed, piercing the surface of sheet 24, until the upper surface of
leg portion 29 lies beneath the lower surface of aluminum base 23. Post 29
may then be rotated until leg portion 39 is approximately perpendicular to
slot 25, thereby locking post 29 into place. Compression spring 30 urges
post 29 upwardly holding leg portion 39 firmly against the lower surface
of base 23. In addition, the spring tension urges wall sections 1 firmly
downwardly against the upper surface of sheet 24, thereby providing a
leakproof seal. It is found that a particular portion of the mold is not
sealed adequately, additional clips 22 may be added, as required.
Then the mold has been filled with the material to be molded, and the
molding process is complete, post 29 of each clip 22 may be rotated until
leg portion 39 lies parallel with its associated slot 25, and post 29 will
spring upwardly to disengage the clips from the wall sections. The wall
sections may then be disconnected and reused as described hereintofore.
The clips 22 can be taken off or left on the wall sections, as required.
FIG. 5 illustrates an alternative method for holding completed mold outline
20 against base 42 by means of a pressure grid, indicated generally at 43,
to prevent leakage of the material to be molded beneath mold 20. Pressure
grid 43 comprises a generally rectangular wire frame 44 having a number of
wire cross members, such as those shown at 45 and 46, spanning the length
of the frame 44. Pressure grid 43 is held firmly against the upper edge of
mold 20 by a plurality of pressure grid clips 47, one of which is shown in
more detail in FIG. 6, located approximately at the corners of frame 44,
and attached at their lower edges to base 42 as will be described
hereinafter.
As is best shown in FIG. 6, each pressure grid clip 47 comprises a
stationary section 48 joined to a sliding section 49 by means of a spring
50. Stationary section 48 includes a lip 51, located at the upper edge of
clip 47, which engages wire rack 43. Lip 51 may be adapted to wrap around
the substantially tubular members of rack 43 in order to prevent clip 47
from becoming disengaged from rack 43. Stationary section 48 also contains
a pair of ears or flanges 52 which form a channel to slidably receive
sliding section 49. Sliding section 49 has at its lower end a semicircular
lip 53 which engages a corresponding slot in base 42, as will be described
hereinafter. Sliding section 49 is slidably received within the channel
formed by flanges 52 of stationary section 48. Stationary section 48 and
sliding section 49 are joined by a spring 50, one end of which is attached
to stationary portion 48, and the other end of which is attached to
sliding portion 49, as is best shown in FIG. 6, thereby urging sliding
portion 49 toward stationary portion 48.
Base 42 contains at its outer periphery a number of slots 54, which engage
lip 53 of clip 47 to hold pressure grid 43 in place atop mold 20. In use,
the shaped mold 20 is placed atop base 42, and pressure grid 43 centered
over the upper edges of the mold sections. The required number of clips
47, four of which are shown for purposes of an exemplary illustration in
FIG. 5, are attached to frame 44 with spring 50 facing inwardly of the
frame such that lip portion 51 firmly engages frame 44. Each clip 47 is
then slid along frame 44 until aligned with a suitable slot 54. Sliding
portion 49 is then extended until the upper edge 55 of lip portion 53 lies
below the lower surface of base 42. Lip 53 is then inserted into slot 54
to complete assembly of the mold. The spring-loaded action of each clip 47
will urge pressure grid 43 tightly against the upper edge of mold 20
thereby compressing the lower edge of the mold sections to provide a
leakproof seal, as described hereintofore for the embodiment of FIG. 3 and
FIG. 4. The pressure grid 43 may be removed and the mold disassembled by
reversing the steps described above.
For purposes of an exemplary showing, the embodiment of FIG. 5 has been
described in conjuncton with a pressure grid 43. It will be understood by
one skilled in the art that the grid 43 may be eliminated and other means
used to insure a leakproof seal between the mold bottom and the base. For
example, a plurality of magnets may be attached to mold 20 for applying a
downward force against the mold upon a metallic base. Likewise, grid 43
may b | | |
