Concrete curb form construction

Aug. 6, 1968

D. E. LAUKALA

3,395,884

CONCRETE CURB FORM CONSTRUCTION

Filed Sept. 15, 1965

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United States Patent Office

3,395,884

Patented Aug. 6, 1968

3,395,884

CONCRETE CURB FORM CONSTRUCTION Delvin E. Laukala, Auburn, Wash., assignor io Mardel Investment Company, Auburn, Wash., a corporation of Washington

Filed Sept. 15, 1965, Ser. No. 487,506

Claims. (Cl. 249—4)

ABSTRACT OF THE DISCLOSURE

A concrete curb form system having vertical side forming walls held during the concrete pouring operation in an exact spaced position one from another by cross-tie bars. One forming wall is staked in position and the opposite side wall is held in position through engagement by a notch, adjacent one end of the tie bar, with a slot formed in the side wall. The tie bar is held at its other end by engagement with a second notch, exactly spaced from the first notch the desired width of the curb and inserted into a slot formed in the staked side wall. The tie bar is held in position by wedges forced between the slot wall and the tie bar and thereby prevents the forming walls from moving away from or toward one another.

This invention concerns a form for use in pouring concrete curbs.

There are forms available for this use, but it is the object of this invention to devise such a form that is simpler and cheaper to make, and faster to install and remove. In particular, it can be securely held in set-Up condition by the use of stakes at one side only, and not at both sides, with these stakes materially farther apart than is customary, even when stakes are used at both sides of the form. This result is achieved by spacing the forms apart in a special way and by special cross-tie bars, whereby the unstaked form wall is firmly held in relation to the staked form wall, against both approach and separation, yet with no detriment to the finished curb. Moreover, the form walls of this invention will serve admirably as rails whereon a curb-pouring machine can run, there being nothing about the forms to interfere with such a machine.

The form of this invention has other advantages. For example, certain wedges can be used to tighten the staked form to its stakes, and these wedges are so mounted that they cannot be detached and mislaid, yet allow adequate freedom of movement of the stakes when required.

A representative embodiment of the invention is illustrated in the drawing, and will be described herein, although it will be evident that it may be embodied in other forms.

FIGURE 1 is an isometric view of the form, largely in set-up condition.

FIGURE 2 is an end elevation of a section of the set-up form.

FIGURE 3 is a plan view of the same, partly broken away in section.

FIGURE 4 is an enlarged detail, in plan section, illustrating a cross-tie bar engaged with one ribbon of the form.

It will be convenient to refer to the individual sides or walls of the form as ribbons, for sections thereof are joined end to end to whatever length is required. The elements that join these ribbons at intervals in their length will be referred to as cross-tie bars.

There are two such ribbons 1 and 2 that make up the form. The back ribbon 1 is normally higher than the front or gutter ribbon 2, and the top surface of the curb between them may be sloped or curved in cross-section. These ribbons preferably are made in predetermined lengths or sections that are interfitted and abutted at their ends, and they should be stiffened longitudinally as well as vertically. Siffening flanges 10 and 11 on the back ribbon and

20, 21 on the gutter ribbon serve to stiffen them longitudinally, and a male projection 12 or 22 at one end of each section engages a female recess of corresponding shape at the adjoining end of the next section. Preferably the female recess on one of two cooperating sections, as at the left on ribbon 1 in FIGURE 1, is at the same end as the male projection, 22, on the other cooperating section. By interengaging the sections thus they are securely held, yet are easily taken down. As many sections are joined as is required for the length of the curb.

One only of the ribbons need be staked. Normally this would be the taller back ribbon 1. Few stakes are needed—fewer than are normally used—for the ribbons are supported each from the other, in a manner to be described shortly. To receive a stake S, a box which constitutes a vertical stiffener, and having opposite upright side walls 13 and a top wall 14, is secured at intervals to the outside of ribbon 1, as by welding. The top wall 14 is apertured to receive the stake, as is the stiffening flange 11 at the bottom, the stake passing through these aperures, and being driven into the ground G. Desirably the stake is of a length to hold firmly, and it should be driven in until its upper end is below the upper stiffening flange 10. Thereby the curb-pouring machine can run along this ribbon 1 and its cooperating ribbon 2, as guiding rails.

To insure that there is no looseness of the stake S in its hole in the upper wall 14, a metal wedge 15, carefully chosen as to its dimensions, may pass through slots in the side walls 13, to wedge the stake tightly in place. An enlargement 16 at the smaller end of the wedge prevents it from pulling out and becoming detached, just as its larger end is too large to pull it out in this direction.

The gutter ribbon 2 does not need to be staked, and preferably is not. Its construction is similar to that of the back ribbon 1, except that it is of less height, and while it may have boxes with upright side walls 23 and a top wall 24, these serve merely as vertical stiffeners, and the top wall need not be apertured for a stake, nor its lower flange 21.

The back ribbon 1 is first located and staked. The gutter ribbon 2 is then rested upon the ground, upright and in approximate spaced relation to ribbon 1. Cross-tie bars 3 are then used to space the ribbon 2 accurately from ribbon 1, and to insure that ribbon 2 is held upright. The two cooperating ribbons each have narrow slots or apertures 17 and 27 at corresponding locations and intervals, preferably one near the upper edge of ribbon 2 and one near its lower end at each location. These slots 17, 27 are of a horizontal length to freely receive the ends of the cross-ties 3. The cross-ties at their ends are notched, at 30, to straddle snugly the thickness of the ribbons 1 and 2, at the ends of their apertures 17 and 27. With the ribbon 1 set up and staked, the cross-ties 3 at top and bottom are inserted within corresponding apertures 17 and 27, and are then moved bodily sidewise—in the direction of the length of the ribbons—until their notches 30 interlock with the ends of apertures 17, 27. This holds the ribbon 2 upright, and correctly spaced from ribbon 1 against approach or separation. If the concrete pour is in the direction such that it might shift the notches of the cross-tie bars 3 out of their interengagement with the ribbons, or if for any other reason greater security of interlock is desired, wedges 31 may be driven into the apertures behind the bars 3.

The spacing between notches 30 at the opposite ends of the cross-tie bars 3 will, of course, correspond to the desired thickness of the concrete curb. A different set of bars will be used for a curb of different thickness.

It has been found that the intervals longitudinally of the ribbons between cross-ties 3 can be rather long. Few of them are needed, for each ribbon section is reasonably stiff, and a few cross-ties at top and at bottom will hold the ribbon 2 securely set up, once the ribbon 1 is correct70

3,395, ³ ly set up—particularly if the cross-ties are located near the vertical stiffeners 13 and 23.

The cross-ties do not stay in place until the concrete hardens. Once the forms are set up and the concrete is poured, parts are left undisturbed until the concrete be- 5 gins to set. Workmen then knock out the wedges 31, if they have been used, and, striking the two projecting ends of each cross-tie 3 with a hammer, these cross-ties are displaced bodily until their notches no longer interlock with the ends of their apertures. Now each one can be _]0tapped and moved endwise, and can be withdrawn from the concrete. It may be helpful to grease them in advance. The concrete, although not hardened, has set sufficiently by this time that the form ribbons will not bulge nor separate from the concrete. Later on they can be re- 15 moved, first the ribbon 2 and then the ribbon 1 and its stakes. All this can be done quickly and with a minimum of effort.