Molding device for modular concrete unit

A molding device includes a multi-sided contractible inner form and outer forms that can be connected detachably to the inner form. The inner form has, at each side, a wedge-shaped spacer formwork board, on which are mounted a power means and a linkage mechanism, disposed between and connected detachably to left and right component formwork boards. The wedge-shaped spacer boards in all sides of the inner form can be pulled inward by individual power means through individual linkage mechanisms to leave space for the left and right component formwork boards to approach one another at all sides to contract the entire inner form.

BACKGROUND OF THE INVENTION 
This invention relates to a molding device, particularly to a molding 
device adapted to mold box-like modular concrete units having large 
assembled formwork boards that can be removed entirely from the molded 
concrete structure and resetted quickly at the next location. 
Molding devices of the above described type have existed in various forms. 
U.S. Pat. No. 2,544,297 discloses an inner collapsible form having 
multiple plate parts interconnected at corners by means of locking 
devices. The inner form collapses and is released from the molded 
structure when the corner plate parts are unlocked. U.S. Pat. No. 
3,614,054 discloses an inner form with a core frame incorporating means 
for collapsing and stripping the inner form from the molded structure. 
U.S. Pat. No. 3,934,808 discloses an inner form having side panels, end 
panels and corner panels. The corner panels can be pulled inward by a 
central single power means through a center linkage mechanism to leave a 
space between the adjacent side panel and end panel so that the whole 
inner form contracts. French Pat. No. 2489206 discloses an inner form 
having internal wall shutters and wedge-shaped corner pieces which can be 
pulled inward by individual power means. The wedge-shaped corner pieces 
are not connected to the shutters and move individually independently of 
the shutters. 
SUMMARY OF THE INVENTION 
The object of the present invention is to provide a molding device 
including a multi-sided contractible inner form and outer forms that can 
be connected detachably to the inner form. The inner form has, at each 
side, a wedge-shaped spacer formwork board, on which are mounted a power 
means and a linkage mechanism, disposed between and connected detachably 
to left and right component formwork boards. The wedge-shaped spacer 
boards in all sides of the inner form can be pulled inward by individual 
power means through individual linkage mechanisms to leave space for the 
approach of the left and right component formwork boards at all sides to 
contract the entire inner form. When each spacer board moves inward, the 
left and right component boards move relatively and approach one another. 
Each linkage mechanism includes a lever pivoted to a corresponding spacer 
board and connected to a hydraulic power means mounted on the spacer 
board, crank members mounted at the upper and lower sides of the spacer 
board and connected to the lever with longitudinal links. There are upper 
and lower links connecting left and right component boards to the crank 
members. 
There are detachable connecting means for the inner form and outer forms 
which includes top fastening means having a first top bar fixed to the top 
of the inner form and having a portion projecting outward, and a second 
top bar fixed to the top of the outer form and having a portion projecting 
inward. One of the top bars has a slot in the projecting portion thereof 
and clamping screws extending threadedly into the slot, and the other top 
bar has a protrusion in the projecting portion thereof to be inserted into 
the slot and to be clamped by the clamping screws. 
The detachable connecting means further includes insert spacer members to 
be disposed between the inner form and the outer forms, and screw 
fasteners for fastening the insert spacer members to the inner form and 
the outer forms. 
The molding device further includes a bottom form, bottom spacer members of 
truncated-cone shape attached detachably to the bottom form and projecting 
upward to be connected to and to support the inner form. There are also 
strut means to support the bottom form, and strut locating members to be 
embedded in part in the concrete floor to secure the lower end of the 
strut means.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIGS. 1, 2 and 3, a molding device is shown, in its molding 
position, including a bottom form board 71, a four-sided inner form 1 and 
four outer forms 2 for molding a box-like concrete structure. The inner 
form 1 comprises a pair of opposing first formwork boards 11a and a pair 
of opposing second formwork boards 11b interconnecting said first formwork 
boards 11a. Each of the first or second formwork boards is set up by using 
channel members 12 and batters 13, and includes a left and right component 
boards 11c and a spacer board 4 between the left and right component 
boards 11c. Each left or right component board 11c has a concrete forming 
face 11d, and a web 11e inclining in relation to the forming face 11d. 
The spacer board 4 has a concrete forming face 4a and two webs 4b inclining 
in relation to the forming face 4a and extending divergingly from the 
forming face 4a, forming a wedge shape in cross-section. The webs 4b of 
the spacer board 4 abut with and are secured to the webs 11e of the right 
and left component boards llc by means of bolts 412. 
A hydraulic cylinder 42, which is used to provide power to move each spacer 
board 4 inward and outward relative to left and right formwork boards 11d, 
is mounted on a bracket 421 fixed to a transverse plate 423 which is 
secured to the webs 4b of the spacer board 4. The dydraulic cylinder 42 
has a piston rod 422 connected to one end A of a lever 43 which is 
pivoted, at point B, to a bracket 432 mounted on a fixed support member 
431 below the hydraulic cylinder 42. An upper longitudinal link 433 is 
connected to the lever 43 at a point C and extends therefrom 
longitudinally upward. At the end point D of the lever 43 is connected a 
lower longitudinal link 434 which extends longitudinally downward 
therefrom. The points D and C are on two sides of the point B. 
Each of links 433 and 434 is connected to crank means 44 provided at the 
top and bottom of the spacer board 4. Each crank means 44 has an arm 445 
connected to the end of link 433 or 434 and extending from a crank shaft 
441 journalled in two journal supports 444 of the spacer board 4. Two arms 
442 extend from crank wheels 44 disposed at the ends of the crank shaft 
441. The arms 442 are connected pivotally to two links 443 respectively 
which are connected pivotally to the adjacent left and right component 
boards 11d. The operation of the hydraulic cylinder and the above linkage 
mechanism will be described hereinafter. 
The webs 4b of the spacer board 4 are connected movably to the webs 11e of 
the left and right component boards 11d by using bolts 412. Each bolt 412 
is threaded through a screw hole of one of the webs 4b into a block 411 
which is fitted movably in an elongated guide groove 111 provided in the 
web 11e of the left or right component board 11d, as shown in FIGS. 3A and 
3B. The blocks 411 can move in the grooves 111 when the spacer board 4 is 
moved relative to the left and right component boards. Angled brackets 413 
are fixed to the webs 4b and then screwed to the left and right component 
boards 11d to secure detachably the spacer board 4 to the left and right 
component boards 11d. In this situation, the spacer boards 4 are wedged in 
between the adjacent left and right component boards, and the forming 
faces 4a thereof are flush with the forming faces of the left and right 
component boards 11d. The whole inner form 1 is in a completely expanded 
position for molding. Each outer form board 2 is assembled using modular 
boards, channel members 22 and batters 23 and 24, and is secured to each 
side of the formwork board of the inner form 1 by securing means. The 
forming faces of the outer form boards are spaced apart from the forming 
faces of the inner form 1. 
The securing means includes insert spacer members 5 incorporating screw 
fasteners for fastening and spacing the forming faces of the outer form 2 
and the inner form 1a, and top fastening means 6 for hanging the outer 
forms 2 on the inner form 1. 
The insert spacer members 5 can be truncated cone-shaped insert bodies 5A 
and/or insert rods 5B as shown in FIGS. 4 and 6. The insert spacer members 
5A and 5B are disposed between the forming faces of the lower sides of the 
outer forms 2 and the inner form 1 and are screwed to the channel members 
22 and 12 of the outer forms 2 and the inner form 1 by using bolts 51 and 
52. 
The truncated cone-shaped insert members 5A can be made of concrete, cast 
iron or the like. Each of them has two opposite threaded bores for 
engaging with the bolts 51 which are attached to the channel member 22 or 
21. The insert rod 5B is a screw rod having two threaded ends for engaging 
with the bolts 52 having threaded bores. 
As shown in FIGS. 7 and 8, the top fastener means 6 includes top bars 61 
secured transversely to a top channel member 12 of the inner form 1 at 
appropriate location, and top bars 62 secured transversely to a top 
channel member 22 of the outer forms 2 at appropriate locations. Each of 
the first bars 61 has a portion projecting outward and a protrusion 611 of 
square cross-section at the top side of said portion. Each of the second 
bars 62 has a portion projecting inward and has a coupling member 623 
disposed fixedly at the top side of said projecting portion. The coupling 
member 623 has a square slot 621 to receive the protrusion 611 and a 
rectangular slot 622 near the slot 621. Four clamping screws 63 are 
attached threadedly to the coupling member 623 and extend into the slot 
621 in directions perpendicular to four sides of the slot 621 
respectively. The rear portion of one of the clamping screws 63 extends in 
the rectangular slot 622. In assembly, the coupling member 623 of the 
second bar 62 is brought to overlap the projecting portion of the bar 61 
so that the protrusion 611 is received in the slot 621 of the coupling 
member 623. Then, the protrusion 611 is clamped tightly in the slot 621 by 
the clamping screws 63, thereby fastening the top sides of the outer forms 
2 to the top side of the inner form 1. Alternatively, the top fastener 
means 6 may be a fastening bar 64 which are screwed to the top side of the 
outer form 2 and the top side of the inner form 1 at its two ends. 
Referring to FIGS. 1 and 5, the bottom formwork board 71 is held by 
horizontal beams 72 and vertical struts (not shown). The bottom side of 
the whole inner form 1 is supported by and spaced apart from the top face 
of the bottom formwork board 71 by using spacer members 5C. The spacer 
members 5C are truncated cone-shaped insert bodies which are placed on and 
screwed to the bottom formwork board 71. 
The molding device set up as described above can be used repeatedly and 
conveniently for casting modular concrete units. The inner form 1, outer 
forms 2, and bottom formwork board 71 can be detached from each other and 
carried to a next location without being disassembled into small units. 
The inner form 1 can be loosened and contracted to be released from the 
concrete structure by detaching the wedge-shaped spacer boards 4 from the 
left and right component boards 11d and moving them outward from between 
the left and right component boards 11d with the hydraulic means. After 
the inner form 1 is contracted it is lifted upward as a whole and sent to 
the next location. Before the inner form 1 is installed at the next 
location, the bottom form board 1 must be set up. Then the inner form 1 is 
put on the spacer insert bodies 5c which are attached to the bottom 
formwork board 71. By operating the hydraulic means, the spacer boards 4 
can be moved again into between left and right component boards 11d to 
expand the whole inner form 1 tightly to the molding position. 
Referring to FIGS. 2 and 3, when each wedge-shaped spacer boards 4 is to be 
pulledinward it is unfastened from the left and right component boards 11d 
by detaching screws 413. The hydraulic cylinder 42 is operated to move 
piston rod 422 to push the lever 43 to turn counter-clockwise about point 
B. In this situation, the link 433 and 434 are moved in the direction 
towards the mid portion of the spacer board 4 from the bottom side and the 
top side, thus rotating the respective crank members 44. The crank members 
44, in turn, move the respective links 443 in the direction towards the 
forming face of the left and right component boards 11d, thereby moving 
the spacer board 4 inward. When the spacer board 4 moves inward, it causes 
the adjacent left and right component boards 11d to approach one another, 
thus contracting the inner form 1 and releasing it from the concrete 
structure, as shown in FIG. 13. 
If the piston rod of each hydraulic cylinder 42 is pulled inward, the 
directions of the movements of the lever 43, links 433 and 434, crank 
members 44 and links 443 are reversed, and each spacer boards is moved 
again into between the adjacent left and right component boards. 
It is described hereinabove that the inner form 1 is supported by the 
bottom form board 71 by means of spacer members 5C when the concrete floor 
is cast simultaneously with the molding of the concrete wall. 
Alternatively, the inner form 1 can be set up after the concrete floor is 
cast. As shown in FIGS. 9 and 10, in casting the concrete floor, truncated 
cone-shaped support bodies 5E are concealed in part in the concrete before 
the concrete is hardened, the top side of the support bodies being exposed 
on the surface of the concrete. Each support body 5E has a threaded bore 
54 and an adjustable threaded core 55 received in the bore 54. There are 
screw holes 56, 57 and 58 provided in the body 54 and core 55. When the 
concrete hardens, the support bodies 5E are secured in the concrete floor 
as shown. At this time, concrete walls can be fabricated by setting up the 
inner form 1 and outer forms 2, The channel members 12 of the inner form 1 
can be connected to the support bodies 5E by inserting screws 59 into the 
threaded bores 58 of the core 55. 
The support bodies 5E secured in a concrete floor can also be used for 
supporting an inner form 1 which is set up to mold the next wall structure 
or an bottom form 71 to mold the next concrete floor in a second floor 
above. As shown in FIG. 11, vertical struts 9 are set upright with their 
lower ends screwed to the cores 55 of the support bodies 5E. The top end 
of each strut 9 is screwed to the beam 72 and the bottom form board 71 for 
supporting the form board 71. The height of the structs can be adjusted by 
rotating the core 55 relative to the support body 5E. 
To immobilize the insert spacer members 5C disposed on the bottom form 
board 71, the spacer members 5C can be screwed to hollow heads 91 of the 
struts 9, as shown in FIG. 12. By using vertical struts 9 and support 
bodies 5E, the whole weight of the inner form 1 and outer forms 2 can be 
bone by the completely hardened concrete of a lower floor. 
Although the inner form 1 described in the present embodiment is a 
four-sided closed form, the present invention is not limited to four sides 
only. The inner form 1 can be a closed form having more or less than four 
sides or an open forming having three sides or more than three sides. 
With the invention thus explained, it is apparent that various 
modifications and variations can be made without departing from the scope 
of the invention. It is therefore intended that the invention be limited 
as indicated in the appended claims.