US3858993A

US3858993A - Reusable tie assembly for concrete forms

Info

Publication number: US3858993A
Application number: US459566A
Authority: US
Inventors: Peter R Lovisa; Dusan Tausanovitch
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-03-07
Filing date: 1974-04-10
Publication date: 1975-01-07
Anticipated expiration: 1992-01-07

Abstract

A retractable, removable and reusable tie assembly for concrete forms which includes a single tie rod, and an internal spreader and spacing system which includes a sleeve means, the spreader system having built-in provisions for internal spreading and spacing of forms in such a manner as to permit the tie rod to be partially withdrawn on one side of the form facilitating the installation of the closing form, on the opposite side, and then to be inserted to engage and lock with the internal spreader system, thus keeping the two adjacent sides of the forms in a definite predetermined position apart during the concrete pour, then to be removed undamaged from the hardened concrete prior to dismantling of the forms, leaving the internal spreader in the concrete to be removed after stripping of the forms without damaging the internal spreader.

Description

United States Patent [191 Lovisaet al.

[45] Jan. 7, 1975 1 REUSABLE TIE ASSEMBLY FOR CONCRETE FORMS [75] Inventors: Peter R. Lovisa, Pelham; Dusan Tausanovitch, Northpor't, both of N.Y.

' [73] Assignee: Tullio E. Lovisa, Huntington Related US. Application Data [62] Division of Ser. No. 232,450, March 7, 1972, Pat.

[52] US. Cl 403/247, 52/753 G, 52/754, 403/256, 403/374, 403/409 [51] Int. Cl. Fl6b 2/14, Fl6b 9/00 [58] Field of Search 52/753 G, 754, 755, 756; 403/247, 252, 254, 256, 374, 409

[56] References Cited UNITED STATES PATENTS 676,984 6/1901 Hofbauer 403/409 X 1,052,200 I 2/1913 Adams 403/247 X 2,353,831 7/1944 Keffer 403/409 X 2,406,668 8/1946 Cohen 403/374 2,562,483 7/1951 Bender 403/247 3,003,733 10/1961 Peterson.. ..52/755X 3,493,272 2/1970 Sylvester et al 403/374 X FOREIGN PATENTS 0R APPLICATIONS 117,947 l/1944 Australia 52/753 G Primary ExaminerWerner H. Schroeder Attorney, Agent, or Firm-Kane, Dalsimer, Kane, Sullivan and Kurucz [57] ABSTRACT V A retractable, removable and reusable tie assembly for concrete forms which includes a single tie rod, and an internal spreader and spacing system which includes a sleeve means, the spreader system having built-in provisions for internal spreading and spacing of forms in such a manner as to permit the tie rod to be partially withdrawn on one side of the form facilitating the in stallation of the closing form, on the opposite side, and then to be inserted to engage and lock with the internal spreader system, thus keeping the two adjacent sides'of the forms in a definite predetermined position apart during the concrete pour, then to be removed undamaged from the hardened concrete prior to dismantling of the forms, leaving the internal spreader in the concrete to be removed after stripping of the forms without damaging the internal spreader.

9 Claims, 13 Drawing Figures PATENTED JAN 71975 SHEET 1 [IF 4 SW m OE PATENTEI] JAN 71975 SHEET 3 OF 4 REUSABLE TIE ASSEMBLY FOR CONCRETE FORMS This is a division, of application Ser. No. 232,450, filed Mar..7, l972,now Pat. No. 3,822,860.

BACKGROUND OF THE INVENTION The general purpose of tie assemblies as a tensile unit is to secure forms in place against the lateral pressure of unhardened concrete.

There are three basic types of ties for concrete forms.

7 First, a continuous single tie rod, usually equipped with 7 tie is a reusable tapered tie, removed from the concrete wall in the direction of larger rod diameter. The third type of tie is an internal disconnecting tie which consists of a threaded inner part that is lost in the concrete and two removable end bolts which project through the form. In all cases, holes left in the concrete surface are plugged or patched by grout.

. The first type of tie, (commonly called snap tie), break back tie, have a smallei' c'ross section, and a weakened section for break back and are feasible only for lighter concrete pressures. They are used with a simple wedge type holding devices, which are hammered in placefor easy adjustment of the forms.

The snap ties are a single unit tie with a built-in spreader system washers, or cones, but has disadvantages in closing and stripping operations of the forms. After the first side of the form is erected and reinforcing steel is installed, the snap tie has to be inserted from the inner face of these forms through the hole in the plywood sheet. In this position snap ties project through the thickness of the future wall and in addition, about 8 inches past the face of the concrete surface. This condition creates time consuming work in matching and pushing fishing of ties through the large number of holes on the plywood sheet when it is installed on the opposite side.

Similar difficulties exist in stripping of the forms. Usually, a form panel or plywood sheet gets stuck on the projected tie heads and long tie ends, which are nearly impossible to place exactly parallel to each other.

To overcome this, ends of snap ties are usually broken before stripping of forms. This cannot be done after the minimum required curing period of the concrete has elapsed since the ties cannot be twisted and broken because they will rotate in the still insufficiently hardened or green concrete. Forms have to remain in place for a longer period and the reusability of the forms is decreased. Finishing can not take place while concrete is still green or relatively soft.

The second type of tie, a tapered tie, requires a coating before each reuse, needs to be hammered or rotated, or both, after concrete is poured, which often requires overtime work. The spreader system is independent of the tie and as such is not positive and reliable. Manufacture and machining of tapered ties is expensive and, therefore, uneconomical for general use.

The third type of tie has an internal disconnecting part and two removable threaded end bolts, commonly known as coil type, and is generally used where heavier loads are required or when using large forming panels known as gang" forms. The bolt ends require screwing and the use of tools to secure them to the form which is time consuming and adds to the labor costs.

Conditions for closing and stripping of forms are much betterthan with a break back tie, but still represent a two man job to match and thread end bolts with intermediate threaded connection, especially for bolts out of reach, located in the middle part of large form panels.

A reusable concrete form tie is disclosed in US. Pat. No. 3,437,309. The tie assembly disclosed is provided with a yieldable tube with a tie rod slidably disposed therein, the tube being employed as the sleeve means between the forms. After the forms have been removed the entire assembly, including the tie rod, is removed from the concrete wall.

SUMMARY OF THE INVENTION The present invention, combines the benefits of snap ties as a single tie rod unit, but without being restricted to a small cross-section and with the benefits of removable end bolts of the coil type tie, thereby providing greatly reduced labor costs in the forming operation, freely retractable, easily installed ,and entirely withdrawn with forms in place. The removable tie rod with a remotely engaged internal spreader assembly represents an entirely new and unique type of tie, thus offering an improved technique in forming operations.

The invention herein generally contemplates the provision of a reusable tie assembly for concrete forms capable of beingdisassembled .after use and which is readily removed from the concrete wall or structure without damage to any portion of the tie assembly. The tie assembly includes an internal spreader means adapted to be positioned between concrete forms and to provide internal spreading and spacing means as well as a passage forreceiving a tie rod. The tie rod is removably mounted in the passage of the sleeve means and is-provided with means defining surfaces engage able with the rodand internal spreader means so that the rod and internal spreader means are disengageable from each other after the concrete has been poured". The 'tie rod is removable therefrom while the forms remain in an erected position thereby permitting the stripping of the forms from the concrete without the necessity of severing tie rods or holding the forms in a position for removal from ends of tie rods embedded in the concrete and with the subsequent removal of the internal spreader means without damage. The invention also contemplates the provision of a novel wedge for removably mounting to the forms and adapted to releasably couple to the ends of the tie rod regardless of the plane of the tie rod passing through the concrete forms. I

lt'is therefore an object of the present invention to provide an improved type of tie assembly which will facilitate the erection and stripping of concrete forms; which readily reduces the labor costs attendant thereto, and which can be disassembled prior to the stripping operation after the concrete structure has been formed. Another object of the invention is to provide a tie assembly which can be easily and quickly installed having a variety of uses including gang forming."

Another object of the invention is to provide a tie assembly which is relatively inexpensive to manufacture, economical to use, readily assembled and disassembled prior to and subsequent to use, with all parts being re- -usable. Another object of the invention is to provide DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded view which illustrates one form of a tie assembly of the invention herein.

FIG. 2 is an elevational sectional view of the tie assembly ready for use. FIG. 3 is a side elevational view of a washer means for releasably mounting the elastomeric sleeve means to the tie rod of the assembly shown in FIGS. 1 and 2.

FIG. 4 is a plan view of the washer means illustrated in FIG. 3.

FIG. 5 is an exploded view of another form of the tie assembly of the invention herein. v

FIG. 6 is an elevational sectional view of the tie assembly ready for use. a

FIGS. 7, 8 and 9 illustrate the steps for erecting and stripping concrete forms employing the tie assembly of the invention herein.

f FIG. 10 is a perspective view of the novel wedge assembly for removably mounting to the ends of the tie rod of FIGS. 1 and 3.

FIG. 11 illustrates the wedge of FIG. 10 mounted to an end of the tie rod of FIG. 1. I .FIG. 12 illustrates the wedge of FIG. 10 mounted to the sleeve endof the tie rod of FIGS.

FIG. 13 is a perspective view of the tie rod coupling means before being mounted to the wedge of FIG. 10.

DESCRIPTION OF THE PREFERRED EMBODIMENT For a better understanding of the invention herein Tie assembly 10 includes tie rod 12 and internal.

spreader means20. Internal spreader means 20 comprises a yieldable elastomeric tubular sleeve Zlhaving mounted at one end 24 a frustro conical cone 22. A passage extending through cone 22 is formed so as to be in axial alignment with the passage of tubular sleeve 21. Cone 22 is generally formed of hard rubber suchas neoprene.

Cone 22 has a lower base 26 and an upper base 28 with an annular recess 30 formed therein and having a diameter substantially equal to the outside diameter of sleeve 21. The annular recess 30 facilitates mounting cone 22 on end 24 by providing contact surfaces within the annular recess for receiving a suitable adhesive so that end 24 is bonded thereto.

Cone 22 has embedded therein adjacent base 26 slotted washer 36. Slotted washer 36 is formed of a rigid material such as steel and forms part of the locking mechanism for removably mounting internal spreader.

means 20 on rod 12. Slotted washer 36 may be formed by a stamping procedure wherein

slots

38 and 39 are formed diametrically opposite to each other. The portion of the slot which is stamped from washer 36

forms depending projections

40 and 41. Also, formed around I the outer edge of base 26 is annular rim 29 which serves as a seal to prevent leakage of concrete through the holes in the forms F.

as illustrated in FIG. 4 but is preferably provided without slots. Also, a similar sealing rim 29' as formed on base 26 is provided on base 27. Formed on the lateral surface of

cones

22 and 23 and adjacent their respective upper bases 28 and 28' are raised

projections

22 and 23 so as to provide stop means to prevent rotation thereof when retracting or removing the tie rod 12.

Tie rod 12 is made of a material having high tensile and shearing properties such as suitable types of steel.

Small projections 14 are formed on rod 12 and are positioned diametrically opposite to each other. Projections 14 may be made by simply pressing the steel rod so as to die cut the rod to form a raised projection on each side thereof. Similarly formed projections 15 are 22 to pass beyond raised projections 14. Then, by simply rotating cone 22 less than 180 internal spreader means 20 will be in locked position on rod 12. Then cone 23 is passedover the end of rod 12 adjacent projections 14 so that cone-23 will be mounted in position as illustrated in FIG. 2.

Formed adjacent each end of rod 12 is a pair of parallel notches l8 and.l9. Thesenotches form part of the locking assembly for'removably mounting the tie rod assembly in fixed position to the forms. Parallel notches l8 and 19 in theembodiment illustrated in FIG. 1 are mounted in a steel holding device-such as illustrated in FIG. 11. Such a steel holding device or wedge is easily mounted ,to a form as illustrated in FIGS. 7 and 8. Wedge 42 is generally rectangular in shape and is made of a malleable steel. A'raised body portion in the form of an incline plane 43 having a longitudinally extending slot 44 isformed therein. At the base of slot 44 an opening 45 is provided for receiving

rod

12 or 62 and also to' provide an access opening for mounting tie rod coupling means 50 in slot 44. Tie rod coupling means 50 is held in fixed slot 44 by a suitable stop means 52. Thus, tie rod anchoring means 50 is slidable Y upper surface has an arcuate recess 56 formed normal to notch 46. The arcuate recess 56 permits the arcuate wall 71 of the respective parallel notches l8, 19, 65 and to contact tie rod coupling means at any angle with respect to the tie rod passing through the concrete forms F illustrated in FIGS. 7 through 9. Also,

- that when wedge 42 is mounted on the fonn as seen in FIG. 11 tie rod coupling means 50 will automatically slip over camming head 64 to releasably lock tie rod 62 in fixed position.

Wedge 42 has increased strength due to the construction of tie rod coupling means 50. When

tie rod

12 or 62 is mounted in fixed position on the forms as illustrated in FIGS. 7 and 8 the forces exerted by the concrete against

tie rod

12 or 62 would tend to shear the ends of the tie rod or tend to deform wedge 42 so that it would fail. However, by providing the tie rod 62 with arcuate wall surfaces 71 the forces exerted on the tie rod are transmitted over the entire mass of tie rod coupling means 50 as illustrated most clearly in FIGS. 11

and 12. It is possible therefore to increase the load of the wedge by providing the structure of tie rod coupling means 50.

FIG. 5 and 6 illustrate another embodiment of a reusable tie assembly 60 for concrete forms capable of being disassembled after use in accordance with the invention herein. Tie assembly 60 comprises tie rod 62 having a flanged head portion 64 formed at end 63 and at the other end 61 is a pair of parallel slots 65. A tubular metal member 68 having a pair of parallel slots 70 is formed at end 69 and at the other end a threaded portion 72 is formed and is adapted to threadably mount internalspreader means 80 thereto. Tubular member 68 is slidably mounted on tie rod 62 so that parallel slots 70 are positioned adjacent the flanged head portion 64. Tubular member 68 is permanently retained on tie rod 62 by forming diametrically 0pposed projections 66 after tubular member 68 has been slidably mounted on rod 62. Projections 63 are formed similar to

projections

14 and 15 of rod 12 as described in FIG. 1. A similar pair of projections 66 are formed and spaced a distance from threaded end 72 of pipe 68 such that when internal spreader means 80 is mounted thereon, as illustrated in FIG. 6, a desired distance for maintaining forms is obtained as illustrated most clearly in FIGS. 7 through 9. Internal spreader means 80 has mounted at one end a frustro conical cone 82 similar in design and formed of similar material to frustro

conical cones

22 and 23 of FIG. 1. Embedded in base 81 of cone 82 is threaded nut 83 adapted to receive in threaded engagement threaded end 72 of tubular member 68. At the other end of internal spreader means 80 is a removable frustro conical cone 84 similar in configuration to frustro

conical cones

22 and 23 of FIG. 1. Embedded in the base of cone 84 is washer 37 similar to the washer 36 of FIGS. 3 and 4 but preferably without slots. Internal sleeve means 80 includes sleeve 86 and forms a passage for tie rod 62. Sleeve 86 is made of an elastic material such as natural or synthetic rubber.

Illustrated in FIG. 8, tie assembly 60 is mounted in position to forms F. Also illustrated mounted in position on tie rod 62 is steel wedge 42. Tie rod coupling means 50 is illustrated having the surfaces defining parallel slots 65 mounted therein while at the other end the surfaces defining parallel slots 70 of tubular member 68 are mounted to slot 44 of wedge 42 as illustrated in FIGS. 11 and 12. Tie rod coupling means 50 is provided with a recess 57 which is of a size to receive a portion of camming head 64 of rod 62. The surfaces defining parallel slots 70 slidably engage the surfaces defining longitudinally extending slot 44. Thus, when tie assembly 60 is mounted in position, as shown in FIGS. 8, 11 and 12, tie rod 62 is incapable of lateral movement since the

parallel slots

65 and 70 are locked in wedge 42 thereby maintaining forms F a predetermined distance defined by the length of internal spreader means 80. Also, by employing the wedge 42, tie assembly 60 does not necessarily require mounting through forms F in a position normal to forms F but may be skew thereto. This is possible since the surfaces defining parallel slots 65 and are formed having arcuate walls 71' and 72'. Similar arcuate walls are formed in

parallel slots

18 and 19 of rod 12. Further, by providing arcuate walls in the parallel slots of the embodiments of FIGS. 1 and 3 and the arcuate recess 56 of tie rod coupling means 50 it is possible to maintain the lateral pressures created by concrete being poured into the space between the forms and to increase the rated load of the wedge without the necessity of increasing the mass of the wedge or tie rod.

In practice, the process for erecting and stripping forms is illustrated in FIGS. 7 through 9. As indicated above, the tie assembly depicted in FIGS. 7 through 9 illustrates the assembly of FIG. 3. Thus, in describing the erection and stripping of forms F illustrated in FIGS. 7 through 9 the tie assembly of FIG. 3 will be described. Tie assembly 60 is disassembled by unthreading tubular member 68 from internal spreader means and is removed from tie rod 62. Tie rod 62 is passed through an openingin form F, then internal spreader means 80 is slidably mounted on tie rod 62 so that only a short distance of tie rod 62 extends beyond removable cone 84 of internal spreader means 80. Then, after all of the tie rods that are to be employed for form F are similarly mounted therein the closing form is mounted by manipulating tie rod 62 into corresponding openings of the second form. Tie rod 62 is then mounted in position by the assembly of steel wedge 40 the parallel members or wallers as illustrated in FIG. 8 and as shown in enlarged elevational view of FIGS. 11 and 12. Tie rod 62 is locked in position by mounting the ends of the tie rod as described for FIGS. 11 and 12. Wedge 42 is held in position simply by a wedging action or, for example, by using a nail through the openings 49 provided in wedge 42 as shown in FIG. 10.

After the concrete has been poured, the nails are removed from wedge 42 and the ends of the tie rod 62 are unlocked by simply removing the steel wedge from the forms. Tie rod 62 is released from tie rod coupling means 50 and is retracted to the point where projections 66 of tie rod 62 contact the end of tubular member 68. When tie rod 62 is removed to the point where projection 66 are contacted by tubular member 68, tubular member 68 is unthreaded from the threaded nut 43 embedded in cone 82. Then tie rod 62 together with tubular member 68 is removed. Tie rod 62 is shown removed'in FIG. 9 so that only internal spreader means 80 remains embedded in the concrete. Forms F are then stripped from the concrete in the usual

fashion exposing cones

82 and 84. Also projections 82' and 84' formed on

cones

82 and 84 prevent rotation of the cones when removing tie rod 62 as described above. Cone 82 is grasped and by simply stretching elastomeric sleeve 86 the bond holding the elastomeric sleeve in the concrete is broken and is then easily removed therefrom. Then by simply grasping cone 84 embedded on the other side of the concrete it is re moved and reassembled as explained above. The passage made by elastomeric sleeve means is plugged in the usual fashion.

' be reassembled for subse- We claim:

l. A wedge adapted to be mounted to a concrete form and capable of releasably coupling a tie assembly, said wedge comprising a generally rectangular body portion and a central portion thereof being raised to form an incline plane, said incline plane having a slot extending longitudinally thereof; tie rod coupling means slidably mounted in said slot and having means formed thereon for releasably mounting said bly to said wedge. 1 2. The wedge of claim 1 wherein an opening is formed at the base of the incline plane adapted. to receive an end of said tie assembly.

3. The wedge of claim 1 wherein stop means is positioned adjacent one wall of the longitudinally extending slot at the base of the incline plane so as to limit the movement of the tie rod coupling means within said slot.

tie assem- 3 wherein said stop menas is projection at the base of the incline movement thereof.

6. The wedge of claim 5 wherein the generally rectangular member is provided having a notch formed in axial alignment with said longitudinally extending slot and adapted to receive an end of said tie to releasably mount said tie rod to said wedge.

7. The wedge of claim 6 wherein the notch formed in the generally rectangular member also includes a recess for receiving and end of the tie rod assembly.

8. The wedge of claim 6 wherein thesurfaces defining the open end of said notch are bevelled to provide camming surfaces so as to permit the rectangular body member to slidably engage the end of the tie rod by force of gravity.

9. The wedge of claim 6 wherein the upper surface of the generally rectangular member is formed having a lateral transverse arcuate the arcuate wall formed in the parallel slot adjacent the end of the tie rod.

recessadapted to engage UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 1 3 ,858,993

DATED 1 January 7, 1975 INVENTOR(5) I Peter R. Lovisa and Dusan Tausanovitch It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 8, line 13, insert after "tie" -=-rod.

Signed and sealed this 17th day of June 1975.

(SEAL) Attest:

C. MARSHALL DANN RUTH C. MASON Commissioner of Patents Attesting Officer and Trademarks

Claims

1. A wedge adapted to be mounted to a concrete form and capable of releasably coupling a tie assembly, said wedge comprising a generally rectangular body portion and a central portion thereof being raised to form an incline plane, said incline plane having a slot extending longitudinally thereof; tie rod coupling means slidably mounted in said slot and having means formed thereon for releasably mounting said tie assembly to said wedge.

2. The wedge of claim 1 wherein an opening is formed at the base of the incline plane adapted to receive an end of said tie assembly.

4. The wedge of claim 3 wherein said stop menas is formed as a raised projection at the base of the incline plane.

5. The wedge of claim 1 wherein the tie rod coupling means comprises a generally rectangular member slidably mounted in said slot and having surfaces extending into the slot which slidably contact the walls defining said slot to prevent substantial rotational and lateral movement thereof.

8. The wedge of claim 6 wherein the surfaces defining the open end of said notch are bevelled to provide camming surfaces so as to permit the rectangular body member to slidably engage the end of the tie rod by force of gravity.

9. The wedge of claim 6 wherein the upper surface of the generally rectangular member is formed having a lateral transverse arcuate recess adapted to engage the arcuate wall formed in the parallel slot adjacent the end of the tie rod.