US3437305A - Self-raising cantilever steel forms for mass concrete - Google Patents

Description

w. w. CURRY 3,437,305

SELF-RAISING CANTILEVER STEEL FORMS-FOR MASS CONCRETE April 8, 1969 Sheet Filed Sept. 11. 1967 INVENTOR WINSTOR W. CURRY ATTORNEYS April 8, 1969 w. w. CURRY 3,437,305

SELF-RAISING QANTILEVER STEEL FORMS PO R MASS CONCRETE INVENTOR WINSTOR W. CURRY ATTORNEYS April 8, 1969 SELF-RAISING Filed Sept. 11, 1967 w. w. CURRY Sheet CANTILEYER STEEL FORMS FOR MASS CONCRETE FIG. 6

WINSTOR W. CURRY WWW ATTORNEYS W. W. CURRY April 8, 1969 SELF-BAISING CANTILEVER STEEL FORMS FOR MASS CONCRETE Sheet Filed Sept. 11, 1967 INVENTOR WINSTOR W. CURRY ATTORNEYS FIG. 11

April 8, 1969 3,437,305

SELF-RAISING CANTILEVER STEEL FORMS FOR MASS CONCRETE Filed se i. 11, 1967 w. w. CURRY Sheet INVENTOR WINSTOR W. CURRY ATTORNEYS United States Patent 3,437,305 SELF-RAISING CANTILEVER STEEL FORMS FOR MASS CONCRETE Winstor W. Curry, San Antonio, Tex., assignoito Ewing- Record & Associates, Inc., Converse, Tex., a corporation of Texas Filed Sept. 11, 1967, Ser. No. 666,727 Int. Cl. E02b 7/02 US. Cl. 249-10 7 Claims ABSTRACT OF THE DISCLOSURE Spaced, stiffened steel panel sections supported against concrete pressure by cantilever members anchored in the previous pour and telescoped to be raised by elevating jack drive connection and transversely by stripping and aligning jacks.

Background of the invention Cantilever steel forms are used extensively in forming mass concrete dams and range from a five foot lift to as high as a ten foot cantilever section. Such forms, although constituting the most economical technique of forming mass concrete, are rather heavy frequently requiring contractors to use portable hydraulic cranes capable of lifting five to eight tons of form at a time. If such heavy cranes are being used at the job site, naturally they can also be used to handle the heavy cantilever forms. However, the high labor costs make it necessary for contractors to find ways to reduce the cost of handling these forms. Naturally, safety dictates that the structural members be in contact with or fastened to the concrete which has previously been poured and obtained the necessary strength.

Siimmary of the invention The lower section of the form member, which is fastened firmly to the previous pour, provides the stability for the upper section which slides within the lower member. The form is stripped away from the concrete by means of horizontal jacks operated mechanically by screw jacks. The long threaded rod is operated and the form is raised to a new position. Then, it is pushed against the concrete and firmly clamped to the previous pour. Finally, the outer section is moved up to reinforce the section already in place and, of course, is located in the position for the next lift after the pour is made.

Description of the drawings FIG. 1 is a side view illustrating the self-raising strongback in pouring position;

FIG. 2 is a side view illustrating the telescoped member beginning to extend;

FIG. 3 is a side view illustrating the self-raising member extended to the next pouring level;

FIG. 4 is a side view illustrating the self-raising strongback support system retracted for reanchor;

FIG. 5 is an elevation view illustrating the panels and standard strongbacks being raised at one time with the use of the self-raising strongbacks;

FIG. 6 is a cross-sectional view taken through the selfraising strongback along line 66 of FIG. 1;

FIG. 7 is a cross-sectional view taken through the selfraising strongback along line 77 of FIG. 1;

FIG. 8 is a cross-sectional view taken through the selfraising strongback along line 88 of FIG. 1;

FIG. 9 is a cross-sectional view taken through the selfraising strongback along line 99 of FIG. 1;

FIG. 10 is a cross-sectional view taken through the self-raising strongback along line 1010 of FIG. 1; and

FIG. 11 is a vertical cross-sectional view taken along line 11-11 of FIG. 1.

Description of preferred embodiment Illustrated in FIG. 5 are a series of form panels, designated by the reference numeral 10, and standard intermediate strongbacks 12, designed to be raised at one time by self raising strongbacks 14 which constitute the heart of the present invention. Walkway brackets 16 attached to form panels 10 are provided adjacent the self-raising strongbacks 14.

FIG. 1 illustrates a typical self-raising strongback 14 in pouring position. The self-raising member 20 is telescoped within support guide 18 and arranged to be elevated and lowered within support guide 18 with the jack drive assembly illustrated in detail in FIG. 11. Specifically, jack rod 22 is mounted to self-raising member 20 through lower connection 24 while also being mounted .to support guide 18 at upper connection 26. Finally, power connection 28 is provided at the top of rod 22. Thus, as power connection 28 is turned, self-raising member 20 and support guide 18 move relative to each other. The turning of rod 22 through power connection 28 may be accomplished, for example, by a portable drill or a permanently mounted air or electric motor fastened to the top of selfraising-member 20.

As seen in FIGS. 6-9, support guide 18 is provided with suitable stiffening members such as flanges 30, for example, which are configured to enclose corresponding flanges 32 of self-raising member 20.

As seen in FIG. 1, support guide 18 is attached firmly to the previous pour with anchor bolt 42. Possible reanchoring on the face may be accomplished by bolt 23 and/ or 21.

The operation of the present invention is initiated by removing the dummy template bolt 34 of the lifter strongback 14 shown in FIG. 1. Then, the anchor bolts 36 are removed at the standard intermediate strongbacks 12 shown in FIG. 5. The form panels 10 and standard intermediate strongbacks 12 are stripped clear of the concrete surface 38, as seen in FIG. 2, by use of the stripping bolt assemblies 40. The power connection 28 is then turned clockwise rotating jack rod 22 raising member 18 until the forms 10 are raised to the correct elevation, illustrated in FIG. 3. The forms 10 are then cleaned and oiled before proceeding to the next stage. Stripping bolt assemblies 40 are extended until the bottoms of the form panels 10 contact the previous poured concrete 43, as seen in FIG. 3. Then, anchor bolts 36 are secured in the standard intermediate strongbacks 12 (FIG. 5) after which anchor bolts 42 are removed at the self-raising strongbacks 14. The stripping bolt assemblies 40 are then used to move self-raising strongbacks 14 out to clear concrete 43. Jack rod 22 is then rotated in a counter-clockwise direction until support guide 18 is raised, as seen in FIG. 4, to the correct height for entering anchor bolts 42 after which they are secured on the self-raising strongbacks 14. Finally, the tops'44 of form panels 10 are aligned.

The details of construction of aligning and Stripping assemblies 40 are shown in FIGS. 6 and 8. Support 46, to which the form panel 10 is attached, is arranged to mov horizontally in relation to element 47 connecting the sides of self-raising member 20. As can be seen in FIG. 1, the sides of support 46 are provided with slots 45 within which element 47 fits. Thus, the movement of rod 48 strips the form panel 10 from the concrete and provides accurate alignment of forms.

I claim:

1. A lifter strongback, comprising:

(A) a support guide;

(B) means rigidly attaching said support guide to poured concrete;

(C) a member;

(D) means telescopically mounting said member within said support guide;

(E) means moving said member relative to said sup port guide;

(F) a form panel; and

(G) means associated with said member for supporting said form panel and retracting same from the face of the poured concrete during movement of said member while said support guide remains rigidly attached to the poured concrete, said means for retracting said form panel from the face of the poured concrete includes a support, means attaching said form panel to said support, means permitting said support to move horizontally in relation to said member telescopically mounted within said support guide including a single screw within said support guide and member for stripping the form panel from the pour d concrete.

2. A lifter strongback as in claim 1, including slot means within said support.

3. A lifter strongback as in claim 2, said member telescopically mounted within said support guide including two separate components, each being generally U-shaped in cross-section and spaced apart from each other, and plural elements connecting said separate components at pre-selected points, one of said elements passing through said slot means contained within said support.

4. A lifter strongback, comprising:

(A) a support guide;

(B) means rigidly attaching said support guide to poured concrete;

(C) a member;

(D) means telescopically mounting said member within said support guide;

(E) means moving said member relative to said support guide;

(F) a form panel; and

(G) means associated with said member for supporting said form panel and retracting same from the face of the poured concrete during movement of said member while said support guide remains rigidly attached to the poured concrete, said means moving the member and support guide relative to each other includes a jack rod located Within said support guide and telescopically mounted member and connected at one end to said support guide and at the other end thereof to said member, means threadedly encompassing said jack rod and secured to said support guide and a power connection for rotating said jack rod t0 raise said member in relationship to said support guide and raise said support guide in relationship to said member, as desired.

5. A lifter strongback as in claim 4, said member including two separate components spaced apart to provide a large opening, and wherein said support guide includes two separate components spaced apart to provide a large opening, each guide component being gradually U-shaped in cross-section and encompassing preselected portions of said two separate components of said telescopically mounted member.

6. A lifter strongback as in claim 5, wherein the means for anchoring the support guide to the poured concrete includes at least one anchor bolt passing through the large openings defined by the spaced apart components of said support guide and member.

7. A lifter strongback as in claim 6, wherein the means for anchoring the support guide to the poured concrete also includes at least one dummy template bolt used as a form for casting said anchor bolt connection within the poured concrete.

References Cited UNITED STATES PATENTS 2,493,264 1/ 1950 Records. 2,620,543 12/1952 Scharsach. 2,649,643 8/ 1953 Schutte 24910 3,071,837 1/1963 Crutti 249-10 3,222,750 12/ 1965 Kimball.

FOREIGN PATENTS 902,188 1/1954 Germany. 460,665 12/ 1950 Italy.

I. HOWARD FLINT, JR., Primary Examiner.

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