ADJUSTABLE FORM FOR CASTING CONCRETE BEAMS
United States Patent 3645490
A plurality of form sections are connected together end-to-end for casting rectangular concrete beams on edge in horizontal position. Each form section is mounted on transverse base beams secured to a concrete foundation or floor. One side form in each form section is mounted on trolleys to roll out on the base beams away from the opposite side form. Provision is made for longitudinal expansion movement of the side forms when they are heated to cure the concrete. Each trolley is equipped with a special locking device to hold the rollout side form in different casting positions for casting beams of different widths. A grooved roller in the locking device engages a bar on a base beam to perform the three functions of locking the trolley against rollout, holding the trolley down to prevent uplift from the fluid pressure of the wet concrete and permitting movement of the locking device with longitudinal expansion and contraction of the rollout side form.
US Patent References:
Mold for concrete objects
McCall - November 1961 - 3010174
Molding apparatus
Tumey - January 1963 - 3071833
Mold for concrete objects
McCall - November 1961 - 3010174
Molding apparatus
Tumey - January 1963 - 3071833
Application Number:
05/077107
Publication Date:
02/29/1972
Filing Date:
10/01/1970
View Patent Images:
Export Citation:
Assignee:
Ted Nelson Company (Portland, OR)
Primary Class:
Other Classes:
249/160
International Classes:
B28B7/02; B28B7/02
Field of Search:
249/50,161,160,26,18,13,117,155 25/41B,41C,131.5G,121M
Primary Examiner:
Overholser, Spencer J.
Assistant Examiner:
Jones, Dewalden W.
Claims:
Having now described my invention and in what manner the same may be used, what I claim as new and desire to protect by Letters Patent is
1. A form for casting concrete beams comprising a first side form, a plurality of base beams extending transversely of said side form, means supporting said side form on said base beams arranged to accommodate longitudinal expansion and contraction of said side form relative to said base beams, trolleys movable on said base beams toward and away from said first side form, a second side form, means supporting said second side form on said trolleys arranged to accommodate longitudinal expansion and contraction of said second side form relative to said trolleys and base beams, bars extending parallel with said side forms mounted on said base beams, grooved lock rollers on said second side form, and a lock linkage arranged to move said rollers into and out of engagement with said bars, said rollers when in engagement with said bars locking said trolleys against movement away from said first side form and locking said trolleys and second side form against uplift, and said rollers rolling on said bars to accommodate said longitudinal expansion and contraction of said second side form.
2. A form as defined in claim 1 including means for mounting said bars at intervals along said base beams to vary the spacing of said second side form from said first side form.
3. A form as defined in claim 2, said last means comprising a series of holes in the sides of said base beams to receive said bars at different locations along said base beams.
4. A form as defined in claim 3 including plates on said bars, and screws securing said plates to said sides of said base beams.
5. A form as defined in claim 1, said lock rollers being approximately horizontal in locked position and engaging the sides of said bars facing said first side form.
6. A form as defined in claim 1, said lock rollers being carried by pivotal arms on said second side frame.
7. A form as defined in claim 1, said bars each projecting from one side of said base beam and said lock rollers being disposed under said second side form at said one side of said base beams.
8. A form as defined in claim 1, said second side form being mounted on the inner ends of said trolleys adjacent said first side form, a horizontal flange on each of said base beams, and antitip rollers on the outer ends of said trolleys remote from said second side form engaging the undersides of said flanges.
9. In a form for casting elongated concrete structures wherein the form is subject to longitudinal expansion and contraction, a base member, a rollout side form on said base member which is subject to an uplift force from the fluid pressure of concrete in the form, and a rollout lock for preventing rollout and uplift of said side form while permitting longitudinal expansion thereof relative to said base member; said lock comprising a longitudinal bar on said base member, a grooved roller on said side form, and a lock linkage arranged to clamp said roller in approximately horizontal position in engagement with the inside edge of said bar and to retract said roller inwardly and upwardly away from said bar.
10. A form as defined in claim 9, said roller being carried by a pivotal arm on said side form for said clamping and retracting movements.
1. A form for casting concrete beams comprising a first side form, a plurality of base beams extending transversely of said side form, means supporting said side form on said base beams arranged to accommodate longitudinal expansion and contraction of said side form relative to said base beams, trolleys movable on said base beams toward and away from said first side form, a second side form, means supporting said second side form on said trolleys arranged to accommodate longitudinal expansion and contraction of said second side form relative to said trolleys and base beams, bars extending parallel with said side forms mounted on said base beams, grooved lock rollers on said second side form, and a lock linkage arranged to move said rollers into and out of engagement with said bars, said rollers when in engagement with said bars locking said trolleys against movement away from said first side form and locking said trolleys and second side form against uplift, and said rollers rolling on said bars to accommodate said longitudinal expansion and contraction of said second side form.
2. A form as defined in claim 1 including means for mounting said bars at intervals along said base beams to vary the spacing of said second side form from said first side form.
3. A form as defined in claim 2, said last means comprising a series of holes in the sides of said base beams to receive said bars at different locations along said base beams.
4. A form as defined in claim 3 including plates on said bars, and screws securing said plates to said sides of said base beams.
5. A form as defined in claim 1, said lock rollers being approximately horizontal in locked position and engaging the sides of said bars facing said first side form.
6. A form as defined in claim 1, said lock rollers being carried by pivotal arms on said second side frame.
7. A form as defined in claim 1, said bars each projecting from one side of said base beam and said lock rollers being disposed under said second side form at said one side of said base beams.
8. A form as defined in claim 1, said second side form being mounted on the inner ends of said trolleys adjacent said first side form, a horizontal flange on each of said base beams, and antitip rollers on the outer ends of said trolleys remote from said second side form engaging the undersides of said flanges.
9. In a form for casting elongated concrete structures wherein the form is subject to longitudinal expansion and contraction, a base member, a rollout side form on said base member which is subject to an uplift force from the fluid pressure of concrete in the form, and a rollout lock for preventing rollout and uplift of said side form while permitting longitudinal expansion thereof relative to said base member; said lock comprising a longitudinal bar on said base member, a grooved roller on said side form, and a lock linkage arranged to clamp said roller in approximately horizontal position in engagement with the inside edge of said bar and to retract said roller inwardly and upwardly away from said bar.
10. A form as defined in claim 9, said roller being carried by a pivotal arm on said side form for said clamping and retracting movements.
Description:
BACKGROUND OF THE INVENTION
This invention relates to an adjustable form for casting concrete beams.
In casting concrete beams of different lengths it is convenient to connect together a plurality of form sections end to end to provide the overall length desired. The forms are preferably heated to accelerate the curing of the concrete, causing considerable longitudinal expansion in the forms when casting a long beam. Removal of the cured beam and cleaning of the form are facilitated by providing a rollaway side on at least one side of each form section. Locking the rollaway form securely in casting position and at the same time allowing expansion movement of the form presents a problem.
Objects of the invention are to provide an improved adjustable form for casting concrete beams, to provide an improved form having a plurality of sections connected together in end to end relation, to provide form sections having adjustable rollout side forms for making beams of different thickness, and to provide a locking device for a rollout side form which locks the side form against roll out and uplift and at the same time allows longitudinal movement with expansion and contraction of a heated form.
SUMMARY OF THE INVENTION
In the present construction each roll out side form is carried by trolleys running on transverse base beams. Each base beam has a horizontal lock bar extending longitudinally of the form which is adjustable to different positions along the beam for casting concrete beams of different thickness. A lock linkage on the side form has a grooved horizontal roller engageable with the lock bar arranged to lock the side form against roll out and uplift while, at the same time, permitting longitudinal movement along the lock bar to accommodate expansion and contraction movements of the form.
The invention will be better understood and additional objects and advantages will become apparent from the following description of the preferred embodiment illustrated on the accompanying drawing. Various changes may be made in the details of construction and arrangement of parts and certain features may be used without others. All such modifications within the scope of the appended claims are included in the invention.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a top plan view of an adjustable form for casting concrete beams embodying the invention;
FIG. 2 is a view on the line 2--2 in FIG. 1;
FIG. 3 is a view on the line 3--3 in FIG. 2; and
FIG. 4 is a view on the line 4--4 in FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a form having a plurality of form sections A, B, C, D and E connected together end to end for casting a common type of prestressed concrete beam. These form sections are identical to each other except that the end section A is mounted on three transverse base beams 10 while each of the other sections is mounted on two of the base beams 10. The base beams 10 are bolted rigidly to a concrete foundation. In a typical form the sections are each 20 feet long and base beams 10 are spaced 10 feet apart.
As shown in FIG. 2, each form section comprises upstanding side forms 11 and 12 and a bottom form 13 which define a space 15 to receive concrete for making a simple rectangular beam. The invention may also be applied to forms for making other beam shapes such as, for example, the wing T form for making T-shaped beams shown in U.S. Pat. No. 3,168,771.
Side form 11 is pivotally supported by a bracket 19 connected by a horizontal pin 20 with a bracket 21 on each base beam 10. The upper portion of side form 11 is braced against the fluid pressure of concrete in space 15 by an inclined strut 22 at each base beam 10. The lower end of the strut is pivotally connected with the base beam by pin 23 and the upper end is connected with side form 11 through a toggle lever 25. By releasing toggle lever 25 side form 11 is tilted outward at a small angle to clear the cured beam in space 15 for removal of the beam from the form.
The lower edge of side form 12 is similarly supported by a bracket 26 connected by a horizontal pin 20 with the inner end of a trolley 30. There is a trolley 30 supported by grooved wheels 31 on a track 32 on top of each base beam 10. A strut 22 and toggle lever 25 are connected between the upper portion of side form 12 and the outer end of trolley 30 for tilting the side form outward as described in connection with side form 11.
When there is no concrete in casting space 15 the weight of side form 12 to the left of the inner wheel 31 would overbalance trolley 30 causing uplift of the outer end of the trolley. In order to stabilize the trolley an antitip roller 33 is mounted on a bracket 34 on the outer end of the trolley. Roller 33 rides on the underside of a horizontal flange 35 on base beam 10 as shown in FIG. 3.
When the form sections are heated to cure the concrete in space 15, longitudinal expansion occurs. Ordinarily the central form section C would be fixedly secured to the foundation causing the end form sections to expand in opposite directions away from section C. Spaces 36 in FIG. 3 provide for such expansion movement of the rollout side forms 12 on trolleys 30. Pin 20 is secured in the ears of bracket 26 which are wider apart than the width of trolley frame 30, allowing limited longitudinal movement of pin 20 in the trolley frame. In a similar manner provision is made for longitudinal expansion of side forms 11 by spacing the ears of bracket 19 farther apart on pin 20 than the ears of bracket 21. This allows clearance spaces similar to the spaces 36 in FIG. 3 for longitudinal movement of bracket 19 and pin 20 relative to bracket 21.
At one side of each trolley 30 a bellcrank lock arm 40 is pivotally mounted on a pin 41 in a depending bracket plate 42 on the bottom of rollout side form 12. A vertical pin 43 carries a grooved lock roller 45 on the lower end of arm 40. Roller 45 is movable toward and away from a horizontal lock bar 46 by a lock linkage having a rod 47 pivotally connected with a pin 48 in the upper end of arm 40. A coupling nut 50 having left and right handed threads provide a turnbuckle type of length adjustment connection between rod 47 and a rod 51. A desired adjustment is maintained by a jamb nut 52. A clevise on the upper end of rod 51 is connected by a pin 53 with a handle lever 55. Handle lever 55 is pivotally mounted on a pin 56 in a bracket 57 on the outside of side form 12.
In the position shown a stop 58 holds the end of lever 55 with pin 53 in overcenter position in relation to pin 56 to clamp lock roller 45 against bar 46 and prevent outward movement to the right of rollout side form 12. When handle 55 is swung outward or clockwise in FIG. 2, the upper end of arm 40 is depressed moving roller 45 to the left away from bar 46 and upward so as to pass over bar 46 when it is desired to move trolley 30 and side form 12 outward to the right on track 32.
Bar 46 is mounted in a plate 60 with its outer end braced by gusset plates 61 and 62. A half round bar 63 is welded on one side of bar 46 to provide a track for roller 45 as shown in FIG. 4. Plate 60 has a pair of arcuate slots 65 concentric with bar 46 to receive capscrews 66 in holes 67 in the side of base beam 10. Bar 46 has an inner end projecting through hole 70 in base beam 10. Thus the bar 46 may be shifted along base beam 10 to move side form 12 in relation to side form 11 for producing the desired width of concrete beam. Arcuate slots 65 permit limited rotation of plate 60 to register the half round track bar 63 accurately in the groove of roller 45.
The fit of track bar 63 in the groove of roller 45 provides a hold down function for side form 12 to resist uplift caused by the lateral fluid pressure of concrete in space 15 acting against the vertical surface of the side form. Fluid pressure in space 15 tends to rotate side form 12 and trolley 30 clockwise about outer trolley wheel 31. As the side form expands in a longitudinal direction with heating the roller 45 rolls on track bar 63 while serving its functions of preventing roll out of trolley 30 and preventing uplift of the left end of the trolley.
Side form 11 may also be mounted on a trolley 30 and provided with lock rollers and bars 45 and 46 if desired.
This invention relates to an adjustable form for casting concrete beams.
In casting concrete beams of different lengths it is convenient to connect together a plurality of form sections end to end to provide the overall length desired. The forms are preferably heated to accelerate the curing of the concrete, causing considerable longitudinal expansion in the forms when casting a long beam. Removal of the cured beam and cleaning of the form are facilitated by providing a rollaway side on at least one side of each form section. Locking the rollaway form securely in casting position and at the same time allowing expansion movement of the form presents a problem.
Objects of the invention are to provide an improved adjustable form for casting concrete beams, to provide an improved form having a plurality of sections connected together in end to end relation, to provide form sections having adjustable rollout side forms for making beams of different thickness, and to provide a locking device for a rollout side form which locks the side form against roll out and uplift and at the same time allows longitudinal movement with expansion and contraction of a heated form.
SUMMARY OF THE INVENTION
In the present construction each roll out side form is carried by trolleys running on transverse base beams. Each base beam has a horizontal lock bar extending longitudinally of the form which is adjustable to different positions along the beam for casting concrete beams of different thickness. A lock linkage on the side form has a grooved horizontal roller engageable with the lock bar arranged to lock the side form against roll out and uplift while, at the same time, permitting longitudinal movement along the lock bar to accommodate expansion and contraction movements of the form.
The invention will be better understood and additional objects and advantages will become apparent from the following description of the preferred embodiment illustrated on the accompanying drawing. Various changes may be made in the details of construction and arrangement of parts and certain features may be used without others. All such modifications within the scope of the appended claims are included in the invention.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a top plan view of an adjustable form for casting concrete beams embodying the invention;
FIG. 2 is a view on the line 2--2 in FIG. 1;
FIG. 3 is a view on the line 3--3 in FIG. 2; and
FIG. 4 is a view on the line 4--4 in FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a form having a plurality of form sections A, B, C, D and E connected together end to end for casting a common type of prestressed concrete beam. These form sections are identical to each other except that the end section A is mounted on three transverse base beams 10 while each of the other sections is mounted on two of the base beams 10. The base beams 10 are bolted rigidly to a concrete foundation. In a typical form the sections are each 20 feet long and base beams 10 are spaced 10 feet apart.
As shown in FIG. 2, each form section comprises upstanding side forms 11 and 12 and a bottom form 13 which define a space 15 to receive concrete for making a simple rectangular beam. The invention may also be applied to forms for making other beam shapes such as, for example, the wing T form for making T-shaped beams shown in U.S. Pat. No. 3,168,771.
Side form 11 is pivotally supported by a bracket 19 connected by a horizontal pin 20 with a bracket 21 on each base beam 10. The upper portion of side form 11 is braced against the fluid pressure of concrete in space 15 by an inclined strut 22 at each base beam 10. The lower end of the strut is pivotally connected with the base beam by pin 23 and the upper end is connected with side form 11 through a toggle lever 25. By releasing toggle lever 25 side form 11 is tilted outward at a small angle to clear the cured beam in space 15 for removal of the beam from the form.
The lower edge of side form 12 is similarly supported by a bracket 26 connected by a horizontal pin 20 with the inner end of a trolley 30. There is a trolley 30 supported by grooved wheels 31 on a track 32 on top of each base beam 10. A strut 22 and toggle lever 25 are connected between the upper portion of side form 12 and the outer end of trolley 30 for tilting the side form outward as described in connection with side form 11.
When there is no concrete in casting space 15 the weight of side form 12 to the left of the inner wheel 31 would overbalance trolley 30 causing uplift of the outer end of the trolley. In order to stabilize the trolley an antitip roller 33 is mounted on a bracket 34 on the outer end of the trolley. Roller 33 rides on the underside of a horizontal flange 35 on base beam 10 as shown in FIG. 3.
When the form sections are heated to cure the concrete in space 15, longitudinal expansion occurs. Ordinarily the central form section C would be fixedly secured to the foundation causing the end form sections to expand in opposite directions away from section C. Spaces 36 in FIG. 3 provide for such expansion movement of the rollout side forms 12 on trolleys 30. Pin 20 is secured in the ears of bracket 26 which are wider apart than the width of trolley frame 30, allowing limited longitudinal movement of pin 20 in the trolley frame. In a similar manner provision is made for longitudinal expansion of side forms 11 by spacing the ears of bracket 19 farther apart on pin 20 than the ears of bracket 21. This allows clearance spaces similar to the spaces 36 in FIG. 3 for longitudinal movement of bracket 19 and pin 20 relative to bracket 21.
At one side of each trolley 30 a bellcrank lock arm 40 is pivotally mounted on a pin 41 in a depending bracket plate 42 on the bottom of rollout side form 12. A vertical pin 43 carries a grooved lock roller 45 on the lower end of arm 40. Roller 45 is movable toward and away from a horizontal lock bar 46 by a lock linkage having a rod 47 pivotally connected with a pin 48 in the upper end of arm 40. A coupling nut 50 having left and right handed threads provide a turnbuckle type of length adjustment connection between rod 47 and a rod 51. A desired adjustment is maintained by a jamb nut 52. A clevise on the upper end of rod 51 is connected by a pin 53 with a handle lever 55. Handle lever 55 is pivotally mounted on a pin 56 in a bracket 57 on the outside of side form 12.
In the position shown a stop 58 holds the end of lever 55 with pin 53 in overcenter position in relation to pin 56 to clamp lock roller 45 against bar 46 and prevent outward movement to the right of rollout side form 12. When handle 55 is swung outward or clockwise in FIG. 2, the upper end of arm 40 is depressed moving roller 45 to the left away from bar 46 and upward so as to pass over bar 46 when it is desired to move trolley 30 and side form 12 outward to the right on track 32.
Bar 46 is mounted in a plate 60 with its outer end braced by gusset plates 61 and 62. A half round bar 63 is welded on one side of bar 46 to provide a track for roller 45 as shown in FIG. 4. Plate 60 has a pair of arcuate slots 65 concentric with bar 46 to receive capscrews 66 in holes 67 in the side of base beam 10. Bar 46 has an inner end projecting through hole 70 in base beam 10. Thus the bar 46 may be shifted along base beam 10 to move side form 12 in relation to side form 11 for producing the desired width of concrete beam. Arcuate slots 65 permit limited rotation of plate 60 to register the half round track bar 63 accurately in the groove of roller 45.
The fit of track bar 63 in the groove of roller 45 provides a hold down function for side form 12 to resist uplift caused by the lateral fluid pressure of concrete in space 15 acting against the vertical surface of the side form. Fluid pressure in space 15 tends to rotate side form 12 and trolley 30 clockwise about outer trolley wheel 31. As the side form expands in a longitudinal direction with heating the roller 45 rolls on track bar 63 while serving its functions of preventing roll out of trolley 30 and preventing uplift of the left end of the trolley.
Side form 11 may also be mounted on a trolley 30 and provided with lock rollers and bars 45 and 46 if desired.