Spring clip and molding form utilizing same

An apparatus for constructing a molding form for a concrete deck structure is disclosed. U-shaped spring clips secure flexible form boards to vertically anchored support stakes, with a flat side of each form board positioned along a desired border of the concrete. Each spring clip has a pair of arms spaced apart, each of which has a slot for receiving an anchored stake. The slots in the two arms are in registration to receive the anchored stake simultaneously, and appendages extend from the free end of each arm to hook onto a concrete form board and secure it to the anchored stake. Each spring clip includes a generally S-shaped flat spring defining a resilient wedge structure near its free end which transmits a spring force that holds the gripped form board firmly against the anchored stake.

BACKGROUND OF THE INVENTION 
The invention relates generally to molding forms and, more particularly, to 
an apparatus for constructing a molding form having an accurately located 
reference surface that establishes a border for the molded structure. 
Molded structures formed along the surface of the ground, such as concrete 
decks, typically are constructed by preparing a firm bed upon which the 
deck is to rest. Border defining forms are provided for confining the 
uncured concrete mixture to a desired border contour. A concrete mixture 
is poured over the prepared bed to fill the form and the surface of the 
poured concrete troweled. After the concrete cures to a firm state, the 
forms are dismantled. 
Two types of molding form structures have been used in constructing 
concrete decks; structures of wood form boards and stakes fastened 
together by nails, and structures of specially formed metal form boards 
and stakes held together by rigid metal wedges. The wood form structures 
are constructed by driving stakes into the ground at intervals along a 
stake line that follows the desired edge contour of the deck. Then, 
flexible form boards of wood, commonly referred to as bender boards, are 
placed against the stakes and fastened thereto by nailing. In most cases, 
the stakes are displaced by the force of nailing, making it virtually 
impossible to locate the reference surface of the bender board at the 
reference line for the border of the deck. In addition to not being able 
to locate the reference surface precisely, the manner of construction of 
such wood form structures causes rapid deterioration of the materials 
used. Repeated nailing weakens the wood bender boards and they frequently 
break during the assembling and dismantling of the forms. The low number 
of repeated uses of the wood bender boards and stakes and the consumption 
of nails is an expense of construction that is becoming increasingly 
significant with the rising costs of construction materials. 
The metal type molding form structure includes a metal form board having a 
pair of apertured appendages extending perpendicularly from one side of a 
planar member, the opposite side of the planar member forming the 
reference surface. A support stake is inserted through apertures of the 
appendages and a separate rigid metal wedge is driven between the stake 
and the facing side of the metal form board. Driving the wedge forces the 
metal form board away from the support stake to cause the stake to bear 
forcefully against the wall of the apertures whereby the metal form board 
is held firmly in place relative to the support stake. A substantial force 
is required to drive the rigid wedge between the stake and the facing side 
of the form board and, frequently, the wedge galls the side and/or support 
stake. After many uses of the metal form boards and support stakes, 
galling often becomes so extensive that the metal form boards and/or 
support stakes are deteriorated beyond use. Even before the metal form 
boards and/or support stakes are deteriorated beyond use, galling may 
deform them to such an extent that accurate location of the reference 
surface that defines the border of the concrete deck is prevented. 
Consequently, the metal type molding form structures do not entirely 
alleviate the shortcomings of the previously described wood type. In 
addition, it is more costly to manufacture and use the metal form 
structures than their wood counterparts. 
Accordingly, considerable advantage is to be gained by the use of 
inexpensive molding form components that are not easily damaged by 
repeated usage. Additional advantages are to be gained by the use of 
molding form components that permit commonly available bender boards to be 
used repeatedly. 
SUMMARY OF THE INVENTION 
The present invention is an apparatus for constructing molding forms 
characterized by the aforementioned and other advantages. Several 
advantages accruing to the apparatus of the present invention are realized 
because of the use of a U-shaped spring clip having a flat spring stressed 
to hold form boards in place. Other advantages are realized by using the 
U-shaped spring clips with a form board that has a pair of open channels 
lengthwise along one of its sides that are gripped by the spring clip. 
More specifically, the U-shaped spring clip of the invention includes a 
generally U-shaped member that has a pair of spaced arms joined together 
at one of their respective ends by a web. Each of the arms extends from 
the web to a free end to join an appendage that extends transverse to the 
plane of the arm to define a hook latch. In use, the hook latch grips the 
form board at opposite sides of its longitudinal center line. To secure 
the form board in place relative to the support stake, a flat spring 
having a bend in its length is pivotally mounted at one of its ends to the 
spaced arms near the web to pass between the arms. Such flat spring has an 
unstressed span surface defined thereby permitting the spring to be 
positioned between the spaced arms and stressed to have its load bearing 
surface bear against the support stake with sufficient spring force to 
hold the form board firmly against the appendaged hook latches and in 
place relative to the support stake. 
The U-shaped spring clip significantly lessens the impact forces imparted 
to the form boards and support stakes during assembly of the molding 
structure. The impact forces are lessened because the unstressed flat 
spring is resilient and has a bend in its length that permits the spring 
to be pivoted and forced into position by wedging its load bearing surface 
against the support stake along a path generally parallel to the form 
board. In dismantling the molding form, the form board is released from 
the support stake by disengaging the wedged spring, in a manner which does 
not impart significant force to the spring. This lessening of the impact 
forces avoids impairing the form boards and support stakes during assembly 
and disassembly of the molding form. Commonly available bender boards have 
been used repeatedly to construct concrete decks without causing 
noticeable damage and would last indefinitely if not for the deterioration 
of the wood caused by the moisture and corrosive materials contained in 
the concrete. 
Wedging the spring in the above-described manner also facilitates the 
construction of a molding form with an accurately located border defining 
surface. The force component produced by the wedging action along a line 
normal to the form board is reduced to such an extent it is incapable of 
disturbing the position of a properly anchored support stake. Therefore, 
the line for anchoring the support stakes can serve as a reference for 
establishing the border defining reference line for the form boards. 
Moreover, the spring clips can be placed at differing positions as needed 
along the lengths of the anchoring stakes to set the form board at a 
desired grade. 
The U-shaped spring clip has the additional advantage of permitting the use 
of commonly available bender boards and support stakes to achieve the 
above-described advantages. However, the construction of mold form is 
facilitated by using the spring clip with a form board having open 
channels longitudinally along one side of the form board opposite its 
reference surface, that can be gripped by the hook latches of the spring 
clip. These open channels permit the form board to be secured to anchored 
support stakes without the structural components of the clip contacting 
the reference surface or longitudinal edges of the form board. Thus the 
form can be dismantled without danger of damaging the molded structure. 
Moreover, the reference surface and longitudinal edges of the form board 
are free of undesirable obstructions which may interfere with surface 
finishing of the concrete. 
The U-shaped spring clip also is instrumental in the method of constructing 
molding forms. In the method, stakes for supporting form boards are 
anchored in a bed serving as a support for the molded structure. The 
stakes are distributed at intervals along a stake line following the 
contour of the reference line defining the desired border contour of the 
structure to be molded. A U-shaped spring clip of the type described above 
is positioned with respect to each anchored stake by threading the stake 
through the registered apertures defined by the U-shaped spring clip. 
After threading by the stakes, form boards are positioned along and 
adjacent to the line of stakes between the spaced arms of the U-shaped 
spring clips. Each form board has a reference surface defined by one of 
its longitudinally extending sides that established the border of the 
molded structure. The form boards are positioned with their respective 
reference surfaces facing away from the anchored stakes. To secure the 
form boards in place relative to the anchored stake, the flat spring of 
each U-shaped spring clip is pivoted between the clip's arms to wedge the 
form board, the clip's hook latches, and the anchored stakes in place 
relative to each other. As a result of the placement of the anchored 
stakes, the reference surface defined by the wedged form board is 
automatically located at the desired position for the border to be 
constructed.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The apparatus of the present invention will be described in detail as 
adapted to construct a molding form for a concrete deck structure for a 
swimming pool. A section of the molding form located adjacent a corner of 
the swimming pool is illustrated in FIG. 1. However, as will become more 
apparent from the following detailed description of the preferred 
embodiments of the invention, the apparatus can be adapted to construct 
molding forms for other concrete structures and for molded structures of 
materials other than concrete. 
In constructing a concrete deck structure against a swimming pool coping, 
the molding form, generally identified by the reference number 11, is 
constructed to define all borders of the concrete deck structure 11 not 
abutting adjacent structures, such as the outer border of the concrete 
deck that is to extend along a desired reference line 12. The inner border 
of the deck abuts and is defined by the coping 13 of a constructed 
swimming pool and, therefore, a molding form is not required. As 
illustrated by FIG. 1, the coping 13 extends along the ground a short 
distance from the upwardly extending side wall 14 of the swimming pool 16 
and is formed during the construction of the pool. Bordering concrete deck 
structures usually are constructed separately and after the pool 
construction. 
The molding form 11 is constructed by anchoring support stakes 17 along a 
stake line 18 plotted along the ground 19 to follow the desired border 
contour of the concrete deck, but spaced from the desired border reference 
line 12 and located outside the area of the deck structure. The support 
stakes are anchored by driving them vertically into the ground 19 and are 
distributed along the stake line 18 at suitable intervals, depending on 
the length of the form boards and the contour of the outer border of the 
concrete deck structure. 
To define the outer border of the concrete deck structure, the required 
form boards 21 are secured to the anchored support stakes 17 so that they 
are held firmly in place along the border reference line 12. At least one 
side 22 of each form board 21 is flat and is positioned along the border 
reference line 12 to form a reference surface facing towards and defining 
the outer border of the concrete deck structure. The widths of the form 
boards 21 are selected according to the thickness of the concrete deck 
structure to be constructed. Flat concrete decks and pedestrian paths 
typically are four inches thick and require molding forms 11 constructed 
with form boards that are four inches wide. Because concrete decks or 
other similar structures often have irregularly contoured borders as 
illustrated in FIG. 1, flexible form boards are used to construct molding 
forms. Wood bender boards are most commonly used to construct molding 
forms for concrete structures. However, more recently, flexible form 
boards have been fabricated from plastic materials. 
In accordance with one aspect of the present invention, spring clips 23 of 
generally U-shaped configuration are employed to secure the form boards 21 
in place relative to the anchored support stakes 17. Exemplary embodiments 
of the U-shaped spring clip useful in constructing molding forms in 
accordance with the present invention are illustrated in and will be 
described in detail hereinbelow with reference to FIGS. 2 through 5 and 9. 
In general, however, a single spring clip 23 is employed with each 
anchored support stake 17 to hold the form boards 21 securely in place 
relative to the anchored stakes. Each spring clip includes a pair of 
spaced apart flat arms 24 and 26 that cooperate with a curved flat spring 
27 pivotally mounted between the arms to hold the form board 21 in place 
relative to the support stake 17. The pair of arms 24, 26 are arranged to 
grip the form board 21 along opposite longitudinal edges 28 and 29 with 
the curved flat spring 27 stressed to bear against the support stake 17. 
The stressed flat spring 27 generates a spring force that acts against the 
anchored stake 17 and the flat arms 24, 26 to hold the gripped form board 
21 securely in place relative to the anchored stake. 
As will become more apparent from the following description of various 
embodiments of the U-shaped spring clip and channelled form board of the 
present invention, the U-shaped spring clip 23 can be used with commonly 
available bender boards to construct molding forms by arranging the arms 
24, 26 to span the longitudinal edges 28 and 29 of the form boards 21 and 
grip the side 22 defining the reference surface. FIG. 6 illustrates such 
an embodiment of the U-shaped spring clip. However, employing form boards 
constructed in accordance with the present invention having channels near 
both longitudinal edges on the side opposite that defining the reference 
surface, such as illustrated in FIGS. 7 through 9, permits the spring 
clips 23 to grip the form boards without obstructing either the reference 
surface side 22 or the top and bottom edges 28 and 29 of the form boards 
21. 
One preferred embodiment of the generally U-shaped spring clip 23 of the 
present invention is illustrated in FIG. 2. Such clip is fabricated from 
metal and includes a generally U-shaped clip 31 that works with a 
pivotally mounted curved flat spring 32 to hold a form board in place 
relative to an anchored support stake. The U-shaped clip 31 includes a 
pair of flat arms 33 and 34 joined together at one of their ends in a 
spaced apart relationship by a curved web member 36. Each of the arms 33, 
34 extends from the web member to a free end 37 and 38, respectively. 
Both of the arms 33 and 34 have longitudinally spaced offset flat end 
segments 41, 42 and 43, 44, respectively, with the offset flat end 
segments of each arm joined together by one of the S-curved central 
segments 46 and 47. Corresponding flat end segments of the arms 33 and 34, 
namely, corresponding end segments 41 and 43 and corresponding end 
segments 42 and 44, extend in spaced apart parallel planes, with the 
corresponding flat end segments 42 and 44 joined to the curved web member 
36 closer together than the corresponding flat end segments 41 and 43 
defining the free ends 37 and 38 of the arms. The corresponding flat end 
segments 42 and 44 are spaced apart a distance that permits the curved 
flat spring 32 to be pivotally mounted between them with the width of the 
flap spring extending between the segments so that the flat spring is held 
centrally between the spaced arms. The distance separating the 
corresponding flat end segments 41 and 43 is determined by the form board 
to be held by the arms 33 and 34. If common bender boards are used to 
construct the molding form, the flat end segments 41 and 43 are spaced 
apart a sufficient distance to permit the bender boards to be placed 
between the arms 33 and 34 with the width dimension of the bender board 
extending between the arms 33 and 34. An example of such bender board and 
spring clip arrangements is illustrated in FIG. 6. On the other hand, if 
channelled form boards of the present invention are used to construct the 
molding form, such as one of the embodiments illustrated in FIGS. 7 
through 9, the flat end segments 41 and 43 are spaced apart only the 
distance for gripping the channels of the form boards. FIGS. 3, 4 and 9 
illustrate examples of such U-shaped spring clip and channelled form board 
arrangements. 
To support the U-shaped spring clip 23 at an anchored support stake, the 
arms 33 and 34 have apertures 51 and 52 cut in them, respectively, with 
one aperture located in each of the flat end segments 41 and 43 defining 
the free ends 37 and 38 of the arms. The apertures 51 and 52 are located 
in the corresponding flat end segments 41 and 43 in registration and are 
of a size that allows an anchored support stake to pass through the 
registered apertures 51 and 52 along a line that is perpendicular to the 
two flat end portions 41 and 43. In the preferred embodiments of the 
U-shaped spring clip 23, the apertures 51 and 52 are elongated slots 
centrally located in the corresponding flat end portions 41 and 43. Each 
slot 51 and 52 extends from a closed end 53 and 54, respectively, to an 
opening at the free end 37 and 38 of each arm 33 and 34 to form in each 
arm a pair of spaced apart coplanar parallel fingers 41a, 41b and 43a, 
43b. However, as will be explained in further detail hereinbelow with 
reference to FIGS. 4A and 4B, the apertures 51 and 52 can take other forms 
such as circular holes in the flat end segments 41 and 43. 
Regardless of the configuration of the apertures 51 and 52, they have a 
dimension in the direction of the width of the respective arms 33 and 34, 
that is just large enough to permit the apertures 51 and 52 to receive an 
anchored support stake. With the apertures 51 and 52 cut in this manner, 
the anchored support stake fits snugly, for example, between the two sets 
of parallel fingers 41a, 44b and 43a, 43b. The snug fit prevents the 
U-shaped spring clip 23 from moving relative to the support stake. This 
can be best understood by reference to FIG. 1. If the apertures are 
considerably larger than the received support stake 17, the spring clip 23 
can be moved along the length of the form board 21. Also, the spring clip 
23 may rotate about its axis of symmetry when the flat spring 27 is 
stressed to bear against the anchored support stake 17 to hold the form 
board 21 securely in place relative to the stake. Either one of those 
movements of the spring clip 23 can lead to mispositioning of the form 
board and damaging of the molding form components. 
To grip the form board, appendages 56a, 56b, 57a and 57b are respectively 
joined to the fingers 41a, 41b, 43a and 43b to form a hook latch with each 
finger at the free ends 37 and 38 of the arms 33 and 34. The appendaged 
hook latches may be curved as illustrated in FIG. 2 or at a sharp angle 
relative to the fingers as illustrated in FIG. 9. Depending on the type of 
form board used with the U-shaped spring clip, the appendaged hook latches 
of the spaced apart arms 33 and 34 may face each other as illustrated in 
FIG. 2 or may face away from each other as illustrated in FIG. 9. The 
appendage hook latches 56a, 56b, 57a and 57b serve to grip the form board 
that is to be held in place relative to an anchored support stake. 
In its preferred form, the U-shaped clip 23 is a unitary piece of metal of 
a thin gauge so that the integral S-curved central portions 46 and 47 and 
flat end segments 41 and 43 of the arms 33 and 34 form a resilient 
structure that permits the flat end portions 41 and 43 to be displaced 
toward and away from each other. The resilient characteristic of the 
structure assists the hook latches 53a and 53b, and 54a and 54b in holding 
a gripped form board firmly in place. 
In the U-shaped spring clip embodiment illustrated in FIG. 2, the flat 
spring 32 is curved lengthwise to form a first bend 61 and a second 
reverse bend 62, which together define a generally S-shape. Spring 32 is 
pivotally mounted between the flat end segments 42 and 44 of the U-shaped 
clip 23 to pass centrally between the spaced apart flat arms 33 and 34, 
with the plane of the spring defined by edges 63 and 64 transverse to the 
planes of the spaced apart flat arms. One end of the flat spring 32 is 
folded on itself to define a hinge joint 66 for pivotally mounting the 
flat spring between the flat end segments 42 and 44. A cotter key 67 
serves as a hinge pin and is inserted for this purpose through registered 
apertures 68, the cotter key 67 being held in place by its ends bearing 
against the outer surfaces of the arms 33 and 34. 
The S-shaped flat spring 32 extends along a curved path from the hinge 
joint 66, through the first bend 61, reverses at the second bend 62 and 
terminates at the free end 71. The second bend 62 is formed by converging 
spring segments 72 and 73 that together define a resilient wedge structure 
having a wedge edge formed by the second bend 62. The face 74 of the wedge 
formed by the converging spring segment 73 extending between the free end 
71 and the second bend or wedge edge 62 defines a load bearing surface 
that faces away from the other converging spring segment 72. The wedge 
face 74 has a recess 76 extending across its width for seating an anchored 
support stake passing through the slots 51, 52 of the arms 33, 34. 
The curved flat spring segment 77 extending between the hinge joint 66 and 
the second bend or wedge edge 62 defines an arc having a curvature such 
that the distance from the first bend 61 to a line extending between the 
hinge joint 66 and the recess 76 is greater than one-half the width of the 
arms 33, 34. Consequently, the curved flat spring segment 77 will extend 
outside the plane defined by the aligned edges 78 and 79 of the spaced 
apart arms 33 and 34, when the flat spring 32 is positioned to bear 
against an anchored support stake extending through the slots 51 and 52. 
This enables the curved flat spring 32 to be conveniently disengaged from 
the stake by inserting a rod or other implement in the clearance between 
the curved flat spring 32 and adjacent edges 78 and 79 of the arms, and 
prying against the edges. 
Referring now to FIGS. 3A and 3B, the U-shaped spring clip 23 described 
above with reference to FIG. 2 is illustrated as arranged to hold a form 
board 81 securely in place relative to a support stake 17 anchored in the 
ground 19. The form board 81 illustrated in FIGS. 3A and 3B is an 
embodiment of the channelled form board illustrated in FIG. 8, which will 
be described in further detail hereinbelow. Briefly, however, form board 
81 has a flat side 82 forming a reference surface that faces towards and 
defines the border of the concrete deck structure to be constructed. 
Joined to the opposite side 83 of the form board 81 is a T-shaped 
structure 84 that extends centrally from the side 83 to define a pair of 
open channels 86 and 87 longitudinally extending along the form board 81 
near its opposite top and bottom edges 88 and 89. 
To secure the form boards 81 in place relative to the anchored support 
stakes 17, each spring clip 23 is positioned with an anchored support 
stake 17 passing through the clip's slots 51 and 52 located between the 
fingers 41a, 41b and 43a, 43b of the arms 33 and 34. For form boards 
having outwardly opening channels as illustrated in FIGS. 3A and 3B, the 
flat end segments 41 and 43 are separated a distance slightly less than 
the distance separating the openings defined by the vertically spaced open 
channels 86 and 87. The appendaged hook latches 56a, 56b, 57a and 57b are 
seated in the channels to grip the form board 81 by forcing the flat end 
segments 41 and 43 apart, positioning the form board 81 with the channels 
86 and 87 located to receive the hook latches, and releasing the flat end 
segments to seat the hook latches in the channels. With the hook latches 
seated in the channels 86 and 87, the fingers 41a, 41b, 43a and 43b of the 
flat end segments 41 and 43 bear against the edges 91 and 92 of the 
T-shaped structure defining the channels 86 and 87. As described 
hereinabove with reference to FIG. 2, this bearing against the form board 
81 assists the spring clip 23 in holding the form board 81. 
With the form board 81 gripped by the appendaged hook latches 56a, 56b, 57a 
and 57b, the S-shaped flat spring 32 is pivoted about its hinged joint 66 
to bring its wedge defining converging spring segment 73 into contact with 
the anchored support stake 17, with the stake 17 abutting the form board 
81 along the facing surface of the T-shaped structure 84. In U-shaped 
spring clip embodiments for holding form boards against anchored support 
stakes as illustrated in FIGS. 3A and 3B, the unstressed span of the 
S-shaped flat spring 32 from the hinge joint 66 to the wedge edge 62, is 
selected to allow the abutted anchored support stake 17 and gripped form 
board 81 to clear the wedge edge 62. However, the unstressed span of the 
flat spring 32 from the hinge joint 66 to the load bearing surface at the 
recess 76 for seating the anchored support stake 17 is greater than that 
which would allow the recess 76 to stand clear of the abutted anchored 
support stake 17 and gripped form board 81. 
The gripped form board 81 is secured to the anchored support stake 17 by 
forcing the flat spring 32 against the stake with sufficient force to 
cause the resilient wedge formed by the converging spring segments 72 and 
73 to be stressed enough to allow the support stake 17 to be seated in the 
recess 76. This can be accomplished conveniently by striking the curved 
flat spring 32 in the vicinity of the bend 61 with a strong blow. With the 
anchored support stake 17 seated in the recess 76, the flat spring 32 
remains stressed to generate a spring force that acts against the anchored 
support stake 17 to force the hinged joint 66 away from the stake and 
thereby cause the attached flat arms 41 and 43 to draw the gripped form 
board 81 firmly against the anchored support stake. 
Several advantages are realized by the molding form embodiment illustrated 
by FIGS. 3A and 3B. Because the anchored support stake 17 bears firmly 
against the entire width of the form board 81, the form board does not 
bend in its plane as a result of the forces exerted by the spring clip 23 
near top and bottom edges 88 and 89 of the form board 81. Typically, form 
boards are thin flexible members, usually having a thickness of about 1/4 
inch, and tend to bend under the influence of locally applied forces. 
Another advantage accruing to the molding form embodiment illustrated by 
FIGS. 3A and 3B is the U-shaped spring clip 23 can be removed after the 
concrete mixture is poured in the molding form to form the concrete deck 
structure. The concrete mixture exerts a force against the form boards 81 
that urges it against the anchored support stake 17. Consequently, the 
U-shaped spring clip is not required to hold the form board 81 in place 
after the concrete is poured. 
Each spring clip 23 is removed by forcing its flat spring 32 out of 
engagement with the anchored support stake 17. Because the curved flat 
spring segment 77 of each extends outside the plane defined by the aligned 
edges 78 and 79 of the spaced apart arms 33, 34 (FIG. 2), a space 93 
exists between the engaged flat spring 32 and the aligned edges. Inserting 
a rod in the space 93 and prying against the edge 78 of the arm 33 forces 
the flat spring 32 out of engagement with the anchored support stake 17. 
Following the disengagement of the flat spring 32, the flat end segments 
41 and 43 are forced apart to unseat the appendaged hook latches 56a, 56b, 
57a and 57b from the channels 86 and 87, and the U-shaped spring clip 23 
is withdrawn from the anchored support stake 17. After the concrete 
mixture has cured, the anchored support stakes 17 are withdrawn from the 
ground 19 and the form boards removed from the border of the constructed 
concrete deck structure. 
FIGS. 4A and 4B illustrate another U-shaped spring clip 23' embodiment of 
the present invention, arranged to hold a form board 101 securely in place 
relative to an anchored support stake 17. The form board 101 illustrated 
in FIGS. 4A and 4B is an embodiment of the channelled form board 
illustrated in FIG. 7, which will be described in further detail below. 
Such form board is similar to that illustrated in FIG. 8, differing in 
that a pair of separate, spaced apart L-shaped structures 102 and 103 
define the longitudinally extending channels 104 and 106 gripped by the 
U-shaped spring clip. In all other respects, the construction of the form 
board 101 illustrated in FIGS. 4 and 7 is similar to that of the form 
board 81 illustrated in FIGS. 3 and 4. 
The U-shaped spring clip 23' illustrated in FIGS. 4A and 4B is similar to 
the spring clip 23 illustrated in FIGS. 2 and 3, differing only in the 
configuration of the curved flat spring 107. Elements of the spring clip 
23' embodiment illustrated by FIGS. 4A and 4B that are like the elements 
of the spring clip 23 embodiment illustrated by FIGS. 2 and 3 are 
identified by the same reference numbers. 
In the U-shaped spring clip embodiment illustrated in FIGS. 4A and 4B, the 
flat spring 107 is curved lengthwise to form a first bend 108 and a second 
reverse bend 109, which together define a generally S-shaped flat spring 
107. The second reverse bend 109 is formed by converging spring segments 
111 and 112 that together define a resilient wedge structure having a 
wedge edge formed by the second bend 109. 
U-shaped spring clip 23' secures a gripped form board 101 relative to an 
anchored support stake 17 by forcing the resilient wedge structure formed 
by the flat spring 107 at the wedge edge 109 between the form board 101 
and the stake 17. Consequently, the faces of both converging spring 
segments 111 and 112 form load bearing surfaces for engaging the form 
board 101 and the support stake 17, with the converging spring segment 112 
having a concave seat 113 for receiving the stake 17. 
The unstressed span of the S-shaped flat spring 107 from its hinge joint 
114 to the wedge edge 109, is selected to pass between the gripped form 
board 101 and the anchored support stake 17, with the stake seated against 
the closed ends 53 and 54 of the slots defined in the spaced apart arms 33 
and 34. However, the unstressed span of the resilient wedge portion of the 
flat spring 107 from the seat 113 of the converging spring segment 112 to 
the corresponding location along the converging spring segment 111, is 
greater than that which would allow the wedge portion of the flat spring 
107 to pass between the gripped form board 101 and the anchored support 
stake 17. 
The gripped form board 101 is secured to the anchored support stake 17 by 
positioning the flat spring 107 with the wedge edge 109 between the 
gripped form board 101 and the anchored stake 17. The converging spring 
segment 111 bears against the surface 116 of the form board 101 extending 
between the spaced apart L-shaped structures 102 and 103 and the 
converging spring segment 112 bears against the anchored stake 17 seated 
against the arms 33 and 34. A force is applied to the flat spring 107 that 
causes the converging spring segments 111 and 112 to be stressed enough to 
allow the resilient wedge to pass between the gripped form board 101 and 
anchored stake 17 and position the stake 17 in seat 113. The stressed flat 
spring 107 generates a spring force that acts against the anchored support 
stake 17 to force the gripped form board 101 away from the stake and to 
draw the hinged joint 114 towards the stake. This draws the arms 33 and 34 
of the U-shaped spring clip 23' firmly against the anchored stake 17 and 
forces the gripped form board 101 firmly against the hook latches 56a, 
56b, 57a and 57b. To ensure that the gripped form board 101 is held 
securely in place relative to the anchored stake 17, the length of the 
fingers 41a, 41b, 43a and 43b (or length of the slots 51 and 52) are 
selected for the S-shaped flat spring 107 so that the flat spring 107 
remains heavily stressed as it bears against the anchored support 17 at 
the closed ends 53 and 54 of the slots 51 and 52 and the form board 101 
gripped by the hook latches. 
In embodiments of the U-shaped spring clip 23' having a flat spring 107 
that passes between the anchored support stake and gripped form board to 
support the form board in place, the open-ended slots 51 and 52 can be 
replaced by a single closed aperture in each of the arms 33 and 34. This 
would eliminate the fingers 41a, 41b, 43a and 43b, and a single appendaged 
hook latch would be located at the free end of each of the arms 33, 34. 
The size of the closed aperture need only be large enough to allow support 
stakes to pass through it. For example, in the U-shaped spring clip 
embodiment illustrated in FIGS. 4A and 4B, circular holes would be used. 
The holes would be located at the closed end of the slots 51 and 52 and 
would be of a diameter slightly larger than the diameter of the support 
stake 17. 
Another embodiment of the U-shaped spring clip of the present invention is 
illustrated in FIG. 5. In this embodiment, the U-shaped spring clip 23" is 
constructed the same as the U-shaped spring clip 23 illustrated in FIG. 2, 
except the S-shaped curved flat spring 32 of spring clip 23 is replaced 
with a curved flat spring 121 having a single spring force creating bend 
122 in its length. The U-shaped clip 23" holds a gripped form board in 
place relative to anchored support stakes in the same manner as 
illustrated in FIGS. 3A and 3B and can be used in place of the U-shaped 
spring clip 23 illustrated in FIGS. 3A and 3B. More specifically, 
appendaged hook latches at the free ends of the arms of the U-shaped 
spring clip 23" (upper arm 33 being illustrated in FIG. 5) are seated in 
channels to grip the form board 81 (upper channel 86 being illustrated in 
FIG. 5). A segment 123 of the flat spring 121 close to the free end 124 of 
the flat spring forms a load bearing surface along its face and defines a 
recess 126 for seating the anchored support stake 17. 
As in the U-shaped spring clip embodiment illustrated in FIGS. 3A and 3B, 
the gripped form board 81 is held securely against the anchored support 
stake 17. This is accomplished by stressing the curved flat spring 121 
with sufficient force to seat the anchored stake 17 in the recess 126. 
With the anchored stake 17 seated in the recess 126, the curved flat 
spring 121 remains stressed to generate the spring force that acts against 
the anchored support stake 17 to draw the gripped form board 81 firmly 
against the stake. The curved flat spring 121 remains stressed because the 
unstressed span from the hinge joint 127 to the load bearing surface at 
the recess 126 is greater than that which would allow the recess 126 to 
stand clear of the abutted anchored support stake 17 and gripped form 
board 81. To facilitate positioning the curved flat spring 121, its 
unstressed span from the hinge joint 127 to the free end 124 is selected 
to allow the abutted anchored support stake 17 and gripped form board 81 
to clear the free end 124. This construction allows the curved flat spring 
121 to be positioned with its recess 126 at the anchored support stake 17 
by gradually increasing the stress in the curved flat spring, hence, the 
force bearing on the support stake 17. By gradually increasing the stress, 
forces harmful to the molding form components are avoided. The 
constructions of the embodiments of the U-shaped spring clip illustrated 
by FIGS. 3 and 4 also incorporate this feature. 
Referring to FIG. 6, the U-shaped spring clip 23 of FIG. 2 is illustrated 
as employed at a junction 131 of contiguous commonly available bender 
boards 132. To hold the contiguous bender boards 132 in place, a support 
stake 17 is anchored at the position of the junction 131 of the boards. 
The corresponding fingers 41a and 43a and appendaged hook latches (not 
visible) of the flat arms 33 and 34 grip the longitudinal edges 133 and 
134 of one of the bender boards 132 while the corresponding fingers 41b 
and 43b and appendaged hook latches of the flat arms grip the longitudinal 
edges 133 and 134 of the other contiguous bender board. A buttress 136 in 
the form of a flat board is placed between the anchored support stake 17 
and the contiguous bender boards 132. The buttress 136 prevents the bender 
boards 132 from bowing at the junction 131 or escaping the hold of the 
U-shaped spring clip 23. The buttressed contiguous form boards 132 are 
held firmly against the anchored support stake 17 by the spring force 
generated by the S-shaped flat spring 32 that is stressed to bear against 
the support stake 17. 
Reference is now made to FIGS. 7 through 9, which illustrate embodiments of 
the flexible form board. As generally described hereinbefore, a form board 
particularly useful in the present invention has channels on opposite 
sides of its longitudinal center line. For example, in the embodiment of 
FIG. 7, the form board 101 has a pair of separate L-shaped structures 102 
and 103 that extend the entire length of the form board 101 near opposite 
longitudinal edges 141 and 142. In the form board 101 illustrated in FIG. 
7, the separate L-shaped structures 102 and 103 define channels 104 and 
106 that open away from each other. The L-shaped structures 102 and 103 
are joined to the side 143 of the form board 101 opposite the side 144 
form the flat reference surface employed to define the border of molded 
structures. In addition, if the form board 101 is to be used with U-shaped 
spring clips 23' of the type illustrated in FIGS. 4A and 4B, the L-shaped 
structures 102 and 103 are preferably spaced apart a distance that is 
sufficient to permit the S-shaped flat spring 107 to be located between 
them and against the surface 116. 
FIG. 8 illustrates another embodiment of the form board. The form board 81 
of that embodiment is similar to form board 101 illustrated in FIG. 7, 
differing in that a T-shaped structure 84 forms the channels 86 and 87 
instead of separate L-shaped structures. The T-shaped structure 84 extends 
the length of the form board 81 and includes a bar member 151 centrally 
joined to a stem member 152. The stem member 152 of the T-shaped structure 
84 is joined at and extends perpendicularly from the side 83 of the form 
board 81, opposite the reference surface defining side 82. 
In both form board embodiments 101 and 81 illustrated by FIGS. 7 and 8, 
respectively, it is preferred to locate the channel defining structures so 
that the U-shaped spring clips are not above the plane of the longitudinal 
board edges when they grip the form boards. As brought out above, such 
construction facilitates assembly, constructing and dismantling of molding 
forms. In the form board 101 illustrated in FIG. 7, the separate L-shaped 
structures 102 and 103 are joined to the side 143 of the form board at 
locations that place the edges 145 and 146 a distance inside the 
longitudinal edges 141 and 142 of the form board 101 that permits the 
U-shaped spring clips to be positioned to grip the channels without 
breaking the planes defined by the edges 141 and 142. Similarly, the ends 
91 and 92 of the bar member 151 of the form board 81 illustrated in FIG. 8 
terminate a distance below the proximate edges 88 and 89 of the form board 
that permits the U-shaped spring clips to so positioned. 
FIG. 9 illustrates additional embodiments of the form board and U-shaped 
spring clip of the present invention. The form board 161 includes separate 
L-shaped structures 162 and 163 joined to a side 164 of the form board at 
its longitudinal edges 166 and 167 to define channels 168 and 169 
longitudinally along the form board 161 that open inwardly. To hold the 
form board 161 in place relative to an anchored support stake 17, a 
U-shaped spring clip 171 is provided. Such U-shaped spring clip 171 is 
constructed like the U-shaped spring clip 23 illustrated in FIG. 2, except 
the appendage hook latches 172 and 173 carried by the spaced apart arms 
174 and 176 face away from each other instead of towards each other. In 
addition, the arms 174 and 176 are spaced apart a distance slightly 
greater than the distance separating the openings into the channels 168 
and 169 so that the arms are stressed to bear against the L-shaped 
structures 162 and 163 when the hook latches 172 and 173 are seated in the 
channels. As described hereinbefore, this aids the U-shaped spring clip 
171 in gripping the form board 161 as the form board is drawn against the 
anchored support stake 17 by a force created by the curved flat spring 177 
bearing against the stake. 
The flexible form board structures illustrated in FIGS. 7 through 9 
preferably are fabricated as integral structures of plastic by extrusion 
processes. However, the flexible form board can be constructed by 
attaching separate channel defining structures to a flat form board with 
suitable fasteners. In addition, it is not necessary that the channels 
extend the entire length of the form board. A plurality of short L-shaped 
(or T-shaped) brackets can be fastened to the form board at intervals to 
define interrupted channels longitudinally along the same. 
Although the invention has been described in connection with preferred 
embodiments thereof, it will be appreciated by those skilled in the art 
that various changes and modifications can be made without departing from 
the spirit of the invention. Therefore, it is intended that the coverage 
of the invention be limited only by the language of the claims and its 
equivalent.