US3588026A

US3588026A - Two-stage form-securing system

Info

Publication number: US3588026A
Application number: US732198A
Authority: US
Inventors: Chester I Williams
Original assignee: Individual
Current assignee: Individual
Priority date: 1968-05-27
Filing date: 1968-05-27
Publication date: 1971-06-28
Anticipated expiration: 1988-06-28
Also published as: DE1926975B2; GB1222347A; DE1926975A1

Abstract

A SYSTEM FOR SECURING FORMS PREPARATORY TO POURING CONCRETE, IN WHICH THE FORM STRUCTURE IS HELD IN PLACE BY FORCES TRANSFERRED THROUGH AN INNER BOLT SECTION ENGAGING AN EMBEDDED ANCHOR, AN OUTER BOLT SECTION VERTICALLY ENGAGEABLE WITH THE INNER BOLT SECTION, A CAM MOUNTED ON THE OUTER BOLT SECTION, A BRACKET SUPPORTING THE CAM AND MOVABLY MOUNTED ON THE FORM, PREFERABLY A SECONDARY INTERLOCK BETWEEN THE OUTER BOLT SECTION AND THE BRACKET, AND AN ADJUSTING DEVICE FOR APPLYING FORCES BETWEEN THE FORM AND THE BRACKET AT LARGE MECHANICAL ADVANTAGE TO GENERATE STRESS IN THE BOLT SECTION AND HOLD THE FORM FIRMLY AGAINST THE FACE OF THE SET CONCRETE OF THE PREVIOUS POUR.

Description

United States Patent 0 m9 H 9 W4 2 2 mum a a mmmmm i ii WHCWW 02349 66666 99999 11111 29 ll I 9 786 84386 7 ,33 20 04 66766 J 23333 h c m m D. a R m r G s m mS mm a w 9 .n l 8 w 9 6% v. MMH. C347M r 0 m 8 n ym v p .m AF .1 ll. 2 2 7 22 l [l Primary Examiner-Charles W. Lanham Assistant Examiner-Ben D. Tobor Attorney-Glenn B. Morse Patented June28, 1971 [54] TWO-STAGE FORM-SECURING SYSTEM 14 Claims, 27 Drawing Figs.

ABSTRACT: A system for securing forms preparatory to pouring concrete, in which the form structure is held in place by forces transferred through an inner bolt section engaging an embedded anchor, an outer bolt section vertically engageable with the inner bolt section, a cam mounted on the outer bolt section, a bracket supporting the cam and movably mounted on the form, preferably a secondary interlock between the outer bolt section and the bracket, and an adjusting device for applying forces between the form and the bracket at large mechanical advantage to generate stress in the bolt section and hold the form firmly against the face of the set concrete of the previous pour.

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m m 9 I488 N n n 999 m n N "H" .L In 302 C am 1 s M mun U IF 054 .l l] l. WEB 2 l0 6 U r 15 U 22 PATENTED JUN28 197i SHEET 1 OF 5 INVENTOR. Chester I. Williams ATTORNEY PATENTEU M28197;

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PATENTEUJUNZBIQY: 8,588,028

Fig. 26

INVENTOR, Chester I. Williams TWO-STAGE FORM-SECURING SYSTEM SUMMARY OF THE INVENTION The construction of dams with concrete is a step-by-step procedure in which successive layers are poured with just enough intervening time to permit each pour to set. The vertical (or inclined) face of the dam is established by forms confining the poured concrete, and these forms are held against the face of the dam by anchor devices embedded in each pour as it is deposited. The accurate maintenance of the face of the dam as a continuous surface is dependent upon the alignment of the forms for each pour, and this phase of the work has necessarily been time consuming. The form sections are usually lifted and placed by a crane, and are then secured by special bolts engaging the anchor devices. Lateral and vertical placement for engagement of the bolts has always been a problem, as well as the tightening of the bolts with enough prestress to withstand the tremendous pressure of concrete poured to a depth of to feet.

The present invention provides a new system for securing the form sections, which simplifies both the placement of the forms and also the stressing of the bolts. The bolt assembly that transfers forces from the embedded anchor to the form structure includes an inner section that acts as a locating projection extending from the face of the concrete, and on which the form can be vertically and horizontally located by a bearing component on the form structure. The placement of the form also has the effect of coupling the inner bolt section to an outer bolt section mounted on the form. This outer bolt section in ludes a preliminary clamping device that can be pulled down quickly and easily with enough force to hold the form in place. The initial securing is followed by an adjustment of a bracket that supports the bolt on the form, and the effect of this adjustment is to apply the necessary prestress to the bolt with much less effort than that involved in the conventional procedure (in which a nut is tightened directly on the bolt against the form). Provision is made for uncoupling the bolt sections so that the form can be backed off from the face of the concrete after the pour has set. This movement is necessary in order to clear the form from the newly placed anchor devices and inner bolt sections held in position by the upper part of the form for embedment in the pour as it is cast.

DETAILED DESCRIPTION The several features of the invention will be analyzed in detail through a discussion of the particular embodiments illustrated in the accompanying drawings. In the drawings:

FIG. 1 is a sectional elevation of the portion of the form structure surrounding the tie system, and shown in a position corresponding to the beginning placement of the form by a crane.

FIG. 2 is a section of the structure shown in FIG. 1, with the initial placement and securing completed.

FIG. 3 shows the position of the form structure and tie system as the form is backed off from the new pour after it has set.

FIG. 4 shows the position of the form following that of FIG. 3, in which the form is being pulled away from the new pour of concrete, at a somewhat inclined position.

FIG. 5 is a perspective view of the inner bolt section.

FIG. 6 is a view of the coupling structure associated with the outer bolt section.

FIG. 7 is a perspective view of the coupling shown in FIG. 6, from the opposite side.

FIG. 8 is a perspective view of the bracket mounted on the form structure for supporting the outer bolt section.

FIG. 9 is a perspective view of the bracket shown in FIG. 8, from the opposite side.

FIG. 10 is a view of the rod portion of the outer bolt section.

FIG. 11 is an enlarged view of the rod section shown in FIG. It), with a portion of the length broken away to permit the use of a larger scale for illustrating the configuration.

FIG. 12 is an elevation on a plane taken perpendicular to the elevation shown in FIG. llll. FIGS. l1 and 12 may be'considered as side and bottom views, with regard to the projection relationship.

FIGS. 13 through 19 are sections on the corresponding planes 13 through 19 of FIG. 12.

FIG. 20 is a front view of the cam an handle on the outer bolt section, showing its relationship with the bolt-supporting bracket.

FIG. 21 is a perspective view showing the cam. the outer bolt section, and its engagement with the supporting bracket.

FIG. 22 is a perspective view of a locating collar associated with a tubular receptacle mounted at the upper part of the form for positioning an inner bolt section (together with an anchor device associated with it) at the upper portion of the form.

FIG. 23 shows the assembled relationship of the tubular receptacle and the inner bolt section.

FIG. 24 shows an adjusting shim for altering the vertical relationship between the form structure and the supporting bolts.

FIG. 25 is a perspective view of the positioning plate on the form structure for engagement with the projecting portion of the inner bolt section for lateral and vertical positioning of the form.

FIG. 26 is a sectional elevation of the portion of the form on which the locating plate is mounted.

FIG. 27 is a top view showing the assembled relationship of the tie system in the position in which the form is fully secured preparatory to the casting of the next pour.

The form structure generally indicated at 30 includes a panel 31 stiffened by a group of horizontal and vertically spaced beams 32. Forces from these beams are received by the pairs of so-called walers 33 and 34 (refer to FIG. 27). These pairs of vertical beams being preferably channel-shaped in configuration, and separated by standard spacing. The distance from one pair to the next will commonly be on the order of 4 to 8 feet. The illustrated form structure is of steel, which is the usual type with which the present invention would be associated. The space between the

vertical walers

33 and 34 is traversed by tie systems of the type shown in FIG. 27,

these being vertically spaced by an amount related to the height of'the forms being used.

It is common practice to incorporate in the form structure some form of locating receptacle for positioning an anchor to be embedded in the newly cast pour so that it is available after the pour has set to tie the form for the next succeeding pour. The developing face 35 of the dam is established by the form structure, and the previous pour 36 contains an anchor device 37 embedded in it through proper placement by an inner bolt section 38 carried by the tubular receptacle assembly 39 shown in FIG. 23. After the pour 36 has set to the necessary strength, the inner bolt section 38 becomes available as a locating projection for positioning the form structure 30 preparatory to making the new pour 40. The tie system 41 (referring to FIG. 27) is responsible for producing the forces necessary to hold the form structure 33 in place against the terrific liquid pressure generated by the presence of the newly cast concrete forming the pour 40.

The embedded anchors 37 are essentially lengths of crimped steel rod heavily cold worked so that the yield point of the material is fairly close to the ultimate strength. This type of material is necessary, as any yielding of the anchor will result in displacement of the form, and the strength of the anchor beyond that point is useless. The best retention of the anchor in comparatively green concrete is obtained through the use of the configuration described and claimed in my U.S. Pat. No. 3,160,988. The ability to sustain the necessary force in green concrete shortens the necessary intervening time between pours, and permits the most effective use of the efficiency provided by the clamping system of this invention. The outer ends of the anchors 37 are threaded for engagement with the internal threading at 42a on the conical inner end 42 of the inner bolt section 38. This threaded engagement is standard, and does not itself form a part of this invention.

Since the major portions of the form structure are relatively standard, it is desirable to provide the components of the present invention as attachments that can be applied to these otherwise standard structures. The panels 31 of the form are modified to the extent of providing holes capable of receiving the outside diameter of the tubular members 43, and these members have flange plates 44 welded as shown at 45 to the periphery at a point set back from the inner end an amount equal to the thickness of the plates 31, so that the inner extremity of the tubes 43 is flush with the inside surface of the plates 31. The inner bolt sections 38 are provided with an annular flange 46 that fully occupies the inside diameter of the receptacle 39, with the inner face of the flanges 46 also being flush, or coplanar, with the inside of the panel 31. The flanges 46 have the primary function of excluding concrete from the interior of the receptacles 39 around the sections 47 of reduced diameter that extend between the flanges 46 and the heads 48. It is preferably that these heads be tapered outwardly to reduced diameter, as shown in FIG. 23, to accommodate a tilting of the form with respect to the inner bolt sections as the form is removed from the set concrete. This same tilting action is further facilitated by providing more clearance between the outside diameter of the head 48 and the inside of the receptacle 39 than is present between the inside of the receptacle and the flange 46. With this arrangement, the flange 46 serves the function of locating the bolt sections 38 with respect to the form, and provides some increase in freedom to disengage the form from the head 48. The axial placement of the bolt sections 38 with respect to the form is obtained through the use of a cross pin 49 which traverses suitable aligned holes in the tubular receptacle member 43 and the cross hole 50 in the bolt section 38. When not in use, the pin 49 remains secured with respect to the form by the presence of the chain 51 secured to the receptacle 39 at the juncture of the flange plate 44 with the tubular member 43. This connection is preferably made simply by welding one of the links in place.

When the form 30 is initially swung into place by a crane, it is maneuvered so that ti approaches the position shown in FIG. 1. The locating plate 52 (shown in FIG. 25') is angular in configuration having the mounting flange 53 secured to the underside of the form structure by bolts 54 traversing the beam 32 of the form, and engaging the nuts 55 welded to the underside of the flange 53. The center of the flange 53 serves as an abutment receiving the end of the adjusting bolt 56 which engages a nut similar to the nut 55, but which is welded to the upper face 57 of the beam 32, the beam being provided with a hole opposite this welded nut to permit passage of the adjusting bolt 56. The bolts 54 may be loosened to permit some degree of vertical displacement of the plate 52 with respect to the beam 32, and the bolt 56 may be adjusted downwardly so that the weight of the form is transferred through the bolt to the flange 53. The bolts 54 may then be tightened selectively, if desired, to generate some degree of lateral adjustment of the form, using the bottom extremity of the bolt 56 as a fulcrum. The portion of reduced diameter 47 of the inner bolt sections is received within the V-shaped lower edge 58 of the plate 52, and the final position of the form is such that the weight of the form is carried on the portion 47 of the inner bolt section, which rests against the central portion 59 of the lower edge of the plate. In this relationship, it will be obvious that any angular adjustment of the plate by relative tightening of the bolts 54, with the adjusting bolt 56 acting as a fulcrum, will produce a slight lateral displacement of the form with respect to the supporting inner bolt sections 38. Lateral adjustability can also be provided by a degree of clearance in the unthreaded holes traversed by the bolts 54. It is inevitable that some accumulations of tolerance occur during the construction of the form and their successive placement on the succeeding pours of concrete, and the adjustments provided here are used to compensate for accumulating misalignment. When once the forms seen to be properly aligned with respect to each other, it is normally preferably to incorporate the shim plates 60 shown in FIG. 24 to fix the relative position of the locating plates 52 with respect to the form structure. These shim plates are provided with cutout portions at 61-63 for receiving the

bolts

54 and 56.

When the form is initially lowered in position as shown in FIG. 1, this action not only serves to place the form vertically and laterally as previously described, but also engages the coupling portion 64 of the outer bolt section 41 with the inner bolt section 38. A simple form of this coupling is illustrated in FIGS. 6 and 7, and includes a pair of side bars 65 and 66 welded to the opposite faces of a heavy nut 67. At the inner end of the

bars

65 and 66, a yoke piece 68 is securely welded, with this piece having a normally downwardly open opening capable of receiving the portion 47 of reduced diameter of the inner bolt sections. The function of the yoke 68 is to slip behind the head 48, and thereby permit transfer of forces from the imbeded anchors 37, through the inner and outer bolt sections, to the form structure. A bar 70 is welded in place so that it spans across between the

bars

65 and 66 to strengthen the coupling in the area adjacent the yoke 68.

The inner extremity of the rod 71 of the outer bolt section is threaded at 710 for engaging the nut 67 of the coupling 64. The outer extremity of this rod traverses the space between the

plates

73 and 74 of the bracket 75 shown in FIGS. 8 and 9. These outer plates are welded to the

opposite side plates

76 and 77, the inner edges of which are bridged on one side by the threaded member 78, and on the other side by the abutment piece 79. The attachment of the bracket 75 to the form structure 30 is best shown in FIG. 27, and this attachment cen ters primarily in the bolt 80. The

side plates

76 and 77 are timed off as shown at 81 and 82 to provide fulcrum edges at 83 and 84 near a vertical plane containing the axis of the bolt 80, so that the bracket 75 is capable of rocking a slight amount about this point. A limited freedom of movement for this rocking motion is provided by the spring washer 85 interposed between the head of the bolt 80 and the bracket 75 so that some looseness is present. The purpose of the abutment piece 79 appears most clearly in FIG. 27, and it prevent s rotation of the bracket 75 with respect to the form so that the bracket remains in a cantilever position extending generally horizontally.

The outer extremity of the rod 41 has a diametral hole 86 receiving the cam pin 87. The

opposite cam plates

88 and 89 are welded to the opposite sides of an actuating handle 90, which is of approximately the same diameter as the transverse dimension across the

flats

91 and 92 at the end of the rod 41. The cams 8% and 89 are eccentrically mounted on the pin 87, and actuation of the handle will therefore vary the axial position of the outer bolt section 41 with respect to the frame 30, with the uncammed" position shown in FIG. 1, and the cammed position shown in FIG. 2. When in the fully cammed" position, it becomes possible to insert the cross pin 93 through the aligned holes 94 and 95 of the bracket 75, and through the hole 96 in the rod 41. This cross pin will have the effect of transferring the forces from the rod 41 to the bracket 75, and thus relieve the

cams

88 and 39 after they have performed their function of positioning the form structure. It is desirable that this direct transfer of force be made through the cross pin 93, as the intensity of these forces is tremendous. The manual actuation of the handle 90 has the effect of pulling the form down into position as shown in FIG. 2, but does not provide enough loading to effectively prestress the tie system. This latter function is provided by the bolts 97 which bear against the flange 98 of the form structure, and are in threaded engagement with the members 78 best shown in FIG. 9. Tightening of the bolts 97 will cause the bracket 75 to rock about the

fulcrum

83 and 84, and generate a stress in the rod M approximately equal to twice the force applied by the bolt 97. This feature of mechanical advantage makes it possible to tighten the bolts 97 with far less effort than is otherwise the case. A direct tightening of the securing nut on a conventional form-securing bolt requires such a high degree of torque, and the use of such a large torque wrench, as to produce a considerable problem for the workmen. .By cutting this force in half, and possibly by using a thread system on the bolt 97 of less pitch than would normally be necessary on a direct bolting arrangement, a much smaller torque wrench can be used.

The spacing between the

plate

73 and 74 is such that the bolt rod 71 can be rotated to all angular positions about its axis only when the portions of reduced

diameter

99, 100, or 101 are present in the space directly between the

plates

73 and 74. The rod 71 may move axially between the

portions

100 and 101 only when the axis of the pin 87 is horizontal, and between the

portions

99 and 100 only when the pin axis is vertical. When the handle 90 is swung downward or upward, as shown in FIGS. 1 and 2, the axial position of the pin 87 is horizontal. The placement of the portion 101 between the

plates

73 and 74 corresponds to the uncammed position of the outer bolt section. ln the cammed position, the portion 100 is between the

plates

73 and 74. The length of these portions is such as to provide an approximate axial positioning of the outer bolt section for the various stages of installing and removing the form. When the form is initially placed, it is desirable that the outer rod assembly be extended inwardly so that the yoke 68 can easily engage behind the head 48 of the inner bolt section. The locking of this axial position by rotating the handle 90 out of a vertical plane prevents accidental jostling from displacing the outer bolt sections during the location ofthe form.

The manner of engagement of the bolt with the bracket obviously permits a considerable amount of articulation of the axis of the bolt with respect to the form, and the extended position of the handle (parallel to the axis of the rod 71) shown in H0. 3 will permit the handle to be pressed downwardly while the pin 87 is vertical and rock the outer bolt section up into the dotted-line position shown in FIG. 3 so that is can be retracted in the direction of the arrow to a point where it will not reengage with the head 48. This position makes it possible to remove the form with a minimum amount of interference form the coupling 64. The retracted position corresponds to a placement of the portion 99 of reduced diameter between the

plates

73 and 74, which is maintained by rotating the

flats

104 and 105 out of alignment by manipulating the handle 90 so that the axis of the pin 87 is off vertical. With this freedom of articulation of the outer bolt section, it is necessary to provide some form of support on the form structure so that the outer bolt-section bolt remains generally horizontal during the placement of the form. The support bar 106 extends between the waler beams 33 and 34 to perform this function, and it will be noted that downward movement of the form may easily result in the accidental jostling of the coupling member prior to arriving at a position of alignment. This movement is easily accommodated without putting any unnecessary stresses on the tie assembly. The angular position of the rod 71 about its axis will naturally either be determined by the effect of gravity urging the handle 90 to the downward position shown in FIG. 2, or by the cam plate 89 resting against the jack bolt 97, with the handle 90 extending laterally. This intermediate position can be utilized to maintain the bolt in the fully retracted position, such that the portion 99 of reduced diameter is embraced between the

plates

73 and 74. With the handle rotated counterclockwise from the position shown in P10. 1, the angular position about the axis can be maintained by the tendency for the handle to rest between the

beams

33 and 34, and thus preserve the fully projected position of the bolt assembly to assist in the coupling of the inner and outer sections.

The particular embodiments of the present invention which have been illustrated and discussed herein are for illustrative purposes only and are not to be considered as a limitation upon the scope of the appended claims. In these claims, it is may intent to claim the entire invention disclosed herein, except as I am limited by the prior art.

lclaim:

1. A system for securing a form for confining poured concrete, the form having a concrete-retaining panel and beam means disposed to transfer stress from said panel to securing bolt means engaging an embedded anchor, wherein the improvement comprises:

a bracket mounted on certain of said beam means, said bracket having an opening:

an outer bolt section received in said opening, said outer bolt section being movable axially with respect to said bracket and having coupling means of the inner extremity of said outer bolt section;

pulldown means having portions thereof disposed to bear on said bracket and said outer bolt section, and operative to axially position said outer bolt section with respect thereto;

means for adjusting under stress the position of said bracket with respect to said fonn in the direction perpendicular to said panel to prestress said system; and

an inner bolt section normally projecting from the face of the concrete established by said panel, and engageable to one end with said anchor, and at the other end with coupling means.

2. A system as defined in claim 1, wherein said form additionally includes a locating member vertically engageable with said inner bolt section, and having a lower edge converging upwardly for laterally positioning said form means by engagement with said inner bolt section.

3. A system as defined in claim 2, wherein said form is supported vertically on said edge.

4. A system as defined in claim 3, wherein said locating.

member is adjustable vertically with respect to said form.

5. A system as defined in claim 1, wherein said coupling means and inner bolt section are provided with interrelated configuration whereby said coupling means is vertically engageable and disengageable from said inner bolt section.

6. A system as defined in claim 5, wherein said outer bolt section is mounted on said form with a freedom of movement whereby said outer bolt section it tiltable in a vertical plane with respect to said form.

7. A system ad defined in claim 1, wherein said bracket has one side secured to said form with limited freedom to rotate about a fulcrum, and said bracket has adjustable jack means at the opposite side thereof, and disposed to bear on said form.

8. A system as defined in claim 7, additionally including auxiliary securing means interengaging said outer bolt section and said bracket.

9. A system as defined in claim 1, wherein said pulldown means includes a cam mounted on said outer bolt section for rotation on a transverse axis, and engageable with said bracket, said cam having actuating handle means.

10. A system as defined in claim 9, wherein said outer bolt section is mounted on said form for rotation about the axis of said outer bolt section in said bracket, and said coupling and inner bolt section have interengageable configurations whereby said coupling is rotatable on said inner bolt section.

1 1. A system as defined in claim 10, wherein said outer bolt section traverses an opening in a member fixed with respect to said bracket, said opening and outer bolt section having interrelated configuration whereby said outer bolt section is axially movable with respect to said bracket only in selected angular positions about the axis of said bolt.

12. A system as defined in claim 1, wherein said form additionally has a tubular receptacle defining an opening in said panel, and disposed to receive an inner bolt section in position for embedment, said inner bolt section having a head and a portion of reduced diameter adjacent said head, said inner bolt section also having a flange disposed to occupy the said panel opening, said receptacle also having disengageable means securing said inner bolt section with respect thereto.

13. A system as defined in claim 12, wherein said inner bolt section has the head thereof tapering outwardly to reduced diameter, and said head has greater clearance within said receptacle than has said flange.

d in olaim 22, wherein said portion of mam with said reduced diameter for laterally positioning said ds substantially from said flange to form, said plate being set outward from the plane of the inside .s-Qid form additionally includes a loca'tface of said fonn panel an amount at least equal to the oz'dly fol engagethickness of said flange.