Formwork system for constructing a structural concrete floor with projecting floor beams

1. A formwork system for constructing a structural concrete floor comprising:

an adjustable main frame ( 100 ) forming a concrete slab formwork structure;

a plurality of adjustable side frames ( 110 ) each movably mounted at the edge of the main frame ( 100 ), each side frame forming a concrete beam formwork structure;

a plurality of retainers mounted at the edge of the main frame for supporting below the side frames;

jacking means for raising and lowering the formwork system;

wherein the main frame is provided with a concrete ceiling slab formwork surface; each side frame ( 110 ) forms the side of a respective concrete beam extended from the concrete ceiling slab; the side frames ( 110 ) being movable enable the formwork system to be effectively detached from a casted structural concrete floor having concrete beams extended therefrom; and the formwork system is extricable on site after fabrication of the concrete ceiling slab floor and beams;

characterized in that

the retainers are cantilever brackets ( 55 ) each comprising:

a side truss ( 165 ) detachably mounted to a main prop ( 30 ) of the main frame ( 100 );

an upper horizontal member ( 170 ) at one end attached to the top portion of the side truss ( 165 );

a lower horizontal member ( 180 ) at one end attached to the side truss ( 165 ) for supporting a respective bottom of a respective side frame;

a vertical bracing ( 185 ) having its upper end attached to the upper horizontal member ( 170 ) and the lower end attached to the lower horizontal member ( 180 );

a side inclined bracing ( 190 ) having one end attached to the lower horizontal member ( 180 ) and an opposite other end attached to the bottom portion of the side truss ( 165 );

a leveling jack ( 195 ) positioned at the end of a formed lower horizontal primary member for supporting a sheathing ( 5 ) for forming the bottom of the concrete beam at an adjustable position; and

a plurality of horizontal beams ( 200 ) transversely disposed at the top of the lower horizontal members ( 180 ) thereof wherein the horizontal beams ( 200 ) each comprising:

a plurality of outer portions each having a relatively large cross sectional area; and

a plurality of inner portions each having a relatively small cross sectional area telescopically received in the outer portion for selective length adjustment of the horizontal beam;

wherein the outer portions are slidable along the inner portions.

2. The formwork system as recited in claim 1 , wherein the side frames ( 110 ) each comprising:

a plurality of sheathings ( 5 ) disposed at the top and the side of the side frame;

a plurality of side beams ( 45 ) spanning across the inner side of the sheathings ( 5 );

a plurality of side props ( 50 ) retaining the side beams ( 45 );

a plurality of mounting brackets ( 160 ) each at one end mounted at a predetermined position to the upper portion of the side prop ( 50 ), the other end of the mounting bracket ( 160 ) is pivotally mounted to the main frame ( 100 ) for enabling the side frame ( 110 ) to be tiltable on a horizontal axis relative to the main frame ( 100 ); and

an inner beam ( 400 ) extending at the inner side of the side props ( 50 ) substantially in a relatively transverse manner below the mounting brackets ( 160 ).

3. The formwork system as recited in claim 2 , wherein the side beams ( 45 ) each comprising:

a plurality of outer portions each having a relatively large cross sectional area; and a plurality of inner portions each having a relatively small cross sectional area telescopically received in the respective outer portions for selective length adjustment of the side beams;

wherein the outer portions are slidable along the inner portions; and the side frame ( 110 ) is facilitated to have an longitudinally extensible surface according to said selective length adjustment.

4. The formwork system as recited in claim 2 , wherein the main frame ( 100 ) comprising:

a plurality of main props ( 30 );

a plurality of sheathings ( 5 ) mounted on top of the main props ( 30 );

a plurality of upper primary beams ( 15 ) mounted to the main props ( 30 );

a plurality of upper secondary beams ( 10 ) mounted to the main props ( 30 ), the upper secondary beams ( 10 ) are disposed on top of the upper primary beams ( 15 ), and the upper secondary beams ( 10 ) spanning below the sheathings ( 5 ); and

a plurality of supporting brackets ( 80 ) each mounted to the main props ( 30 ) for propping the upper primary and secondary beams ( 15 & 10 );

wherein the upper secondary beams ( 10 ) are disposed in a substantially transverse manner relative to the upper primary beams ( 15 ).

5. The formwork portion as recited in claim 4 , wherein the mounting brackets ( 160 ) each comprising:

an elongated aperture ( 515 ) formed at the inner end thereof for securing means to pivotally secure the mounting bracket ( 160 ) to the corresponding upper primary beam of the main frame ( 100 ); and an aperture formed at the outer end thereof for securing means to fix the mounting bracket ( 160 ) to the side prop ( 50 ) of the side frame ( 110 ).

6. The formwork system as recited in claim 4 , wherein the upper primary beams ( 15 ) each comprising:

a plurality of outer portions ( 302 b ) each having a relatively large cross sectional area; and a plurality of inner portions ( 304 b ) each having a relatively small cross sectional area telescopically received in the outer portions ( 302 b ) for selective length adjustment of the upper primary beam ( 15 );

wherein the outer portions ( 302 b ) are slidable along the inner portions ( 304 b ); and the main frame ( 100 ) is adjustably extensible according to said selective length adjustment.

7. The formwork recited as recited in claim 4 , wherein the upper secondary beams ( 10 ) each further comprising:

a plurality of outer portions ( 302 a ) each having a relatively large cross sectional area; and a plurality of inner portions ( 304 a ) each having a relatively small cross sectional area telescopically received in the outer portions ( 302 a ) for selective length adjustment of the upper secondary beam ( 10 );

wherein the outer portions ( 302 a ) are slidable along the inner portions ( 304 a ); and the main frame ( 100 ) is adjustably extensible according to said selective length adjustment.

8. The formwork system as recited in claim 4 , wherein the main frame ( 100 ) further comprising a plurality of legs ( 32 ) each mounted to the corresponding main prop ( 30 ) of the main frame ( 100 ).

9. The formwork system as recited in claim 1 further comprising an end side frame ( 140 ) having:

a plurality of sheathings ( 5 );

a plurality of outer side beams ( 210 ) spanning across the inner side of the sheathings ( 5 );

a plurality of outer side props ( 215 ) retaining the outer side beams ( 210 ); and

a plurality of outer inclined bracings ( 220 ) at the upper end mounted to the top portion of the outer side props ( 215 ).

10. The formwork system as recited in claim 9 , wherein the outer side beams ( 210 ) each comprising:

a plurality of outer portions each having a relatively large cross sectional area; and

a plurality of inner portions each having a relatively small cross sectional area telescopically received in the outer portions for selective length adjustment of the side beam;

wherein the outer portions are slidable along the inner portions; and the outer side frame is facilitated to have an longitudinally extensible surface according to said selective length adjustment.

11. The formwork system as recited in claim 1 further comprising a cantilever portion ( 150 ) comprising:

a plurality of inner side trusses ( 225 ) each adjustably mounted to the main prop ( 30 ) of the main frame ( 100 );

a plurality of outer side truss ( 230 ) each having a horizontal bracing ( 240 ) at lower portion thereof connected to the inner side truss ( 225 );

a plurality of horizontal shafts ( 245 ) each propped at the top ends of the inner side truss ( 225 ) and the outer side truss ( 230 );

a plurality of diagonal beams ( 250 ) each attached to the lower portion of the outer side truss ( 230 ) and the outer end of the horizontal shaft ( 245 );

a longitudinal beam ( 255 ) mounted transversely on the horizontal shafts ( 245 ) to retain the side frame;

a plurality of retaining beams ( 510 ) mounted transversely on the horizontal shafts ( 245 ) and positioned between the side frame ( 110 ) and the end side frame ( 140 ); and

a longitudinal sheathing mounted on the retaining beams ( 510 );

wherein the outer inclined bracings ( 220 ) each at the lower end are coupled substantially to the outer end of the corresponding horizontal shaft ( 245 ).

12. The formwork system as recited in claim 11 , wherein the longitudinal beams ( 255 ) each comprising:

a plurality of outer portions each having a relatively large cross sectional area; and

a plurality of inner portions each having a relatively small cross sectional area telescopically received in the outer portions for selective length adjustment of the longitudinal beam ( 255 );

wherein the outer portions are slidable along the inner portions; and the cantilever portion ( 150 ) is facilitated to have an adjustably extensible length according to said selective length adjustment.

13. The formwork system as recited in claim 11 , wherein the retaining beams ( 510 ) each further comprising:

a plurality of outer portions each having a relatively large cross sectional area; and

a plurality of inner portions each having a relatively small cross sectional area telescopically received in the outer portions for selective length adjustment of the retaining beam;

wherein the outer portions are slidable along the inner portions.

14. The formwork system as recited in claim 4 further comprising:

a plurality of lower primary beams ( 25 ) mounted to the main props ( 30 );

a plurality of lower secondary beams ( 20 ) mounted to the main props ( 30 ); the lower secondary beams ( 20 ) are disposed on top of the lower primary beams ( 25 ), ( 20 );

a plurality of vertical bracings each at the top end mounted to the upper primary beam ( 15 ) and at the bottom end mounted to the lower primary beam ( 25 ); and

a plurality of inclined bracings each mounted to the corresponding lower primary beam ( 25 ) and the corresponding main prop ( 30 );

wherein the lower secondary beams ( 20 ) are substantially disposed in a transverse manner relative to the lower primary beams ( 25 ).

15. The formwork system as recited in claim 14 , wherein the lower primary beams ( 25 ) each comprising:

a plurality of outer portions each having a relatively large cross sectional area; and

a plurality of inner portions each having a relatively small cross sectional area telescopically received in the outer portions for selective length adjustment of the upper primary beam ( 25 );

wherein the outer portions are slidable along the inner portions; and the main frame ( 100 ) is adjustably extensible according to said selective length adjustment.

16. The formwork system as recited in claim 14 , wherein the lower secondary beams ( 20 ) each further comprising:

a plurality of outer portions each having a relatively large cross sectional area and a plurality of inner portions each having a relatively small cross sectional area telescopically received in the outer portions for selective length adjustment of the lower secondary beam;

wherein the outer portion is slidable along the inner portion; and the main frame ( 100 ) is adjustably extensible according to said selective length adjustment.

17. The formwork system as recited in claim 2 , wherein the inner beam ( 400 ) comprising:

a plurality of outer portions each having a relatively large cross sectional area; and a plurality of inner portions each having a relatively small cross sectional area telescopically received in the outer portions for selective length adjustment of the side beam;

wherein the outer portion is slidable along the inner portion; and the side frames ( 110 ) is facilitated to have an longitudinally extensible surface according to said selective length adjustment.

18. The formwork system as recited in claim 8 , wherein the plurality of legs ( 30 ) each at the bottom portion thereof are attached with base support which includes jacking means ( 260 ).

19. The formwork system as recited in claim 8 , further comprising a plurality of wheels ( 265 ) attached at the bottom of the legs ( 32 ) for transportation purpose.