US2114328A - Concrete key strip support - Google Patents

Description

J. F. BA TON.

CONCRETE KEY STRIP SUPPORT April 938.

Filed July 19, 1937 Patented Apr. 19, 1938 UNITED STATES PATENT OFFICE 6 Claims.

This invention relates to certain new and useful improvements in concrete key strip supports, the peculiarities of which will be hereinafter fully described and claimed.

In concrete road making, a slab is laid on one half the width of the roadway and a V-strip is supported against the form forming the center of the road so as to leave a longitudinal groove in the edge of the slab to provide a key for the other half slab when it is laid. Various means for supporting such a key strip while the concrete is poured and being rammed have been employed in the prior art, such as hanging it from a'goose neck mounted above the form; another with pronged nails; and another bolts to the form.

My invention provides for setting the key strip after the grade is finished and offers a firm support for the key strip, which support does not extend above the form and is not liable to interference by the power graders and planer, nor while pouring the slab; my key strip is firmly supported against the inner face of the adjacent form without connecting bolts, is maintained in proper position while the concrete is being rammed; and is readily disengaged from the slab after the concrete has set, with little or no damage to the key strip or its support, so that it promotes continual use of the key strip with resultant economy.

In the accompanying drawing in which like reference numerals indicate corresponding parts,

Fig. 1 represents a perspective view of a concrete slab with a form and key strip in place, and my improved support ready for removal of the strip after the concrete has set;

Fig. 2 an enlarged view of a portion of the same;

Fig. 3 a plan view showing a portion of a form 0 partly in section, a key strip having my support, and a stake in section below the prong, holding the strip close to the inner face of the form ready for pouring and ramming the concrete;

Fig. 4 a side view of my stake and its prong;

Fig. 5 a back view of the same; and

Fig. 6 a top view of the stake.

Referring to the drawing, the numeral I indicates a slab of concrete as laid for half of the width of the road having a form 2 at its inner edge and wooden key strip 3 (commonly known as a V-strip) for forming a longitudinal groove in the inner edge of the slab.

Said groove is filled by the concrete when the adjacent slab is poured and keys the two slabs together on the center line of the road.

My support for the key strip consists of a flat metal bar in the form of a strap, one end 4 of which is laid into the face of the key strip so as to be flush therewith, and then is bent over the top down the back side, forward under the strip, then down in the same vertical plane as the end 4 forming a vertical leg 5 about half the slab thickness, or long enough to allow an outwardly projecting foot 6 to be driven at right angles under the form as indicated in Figs. 1, 2, and 3.

- A flat head bolt passes through the-end 4 and the back strap to hold the enclosed strip firmly by a nut l.

The key strip'is thus firmly held and supported midway of the proposed thickness of the slab and rests on the shoulder 8 of the strap, so that the strip will maintain its position while the concrete is being rammed above and below it. The upper end of the strap support may be otherwise formed in connection with the leg, and secured to the key strip in any suitable manner.

The foot 6 under the form (see Fig. 3) holds the leg and strip from rising, and the foot also supports them from the ground while the concrete is beingrammed above and below said strip.

As a further assurance of the strip remaining 1 in contact with the inner face of the adjacent form while the concrete is being poured and rammed, I provide a stake 9 having a beveled point II and a lateral prong ID near its top that engages the top of the support or otherwise, when driven into the ground adjacent the key strip. The beveled point ll causes the stake, when driven, to incline toward the key strip and press it against the face of the form, while the prong assists the foot 6 in holding down the strip.

The preferred form of said stake is shown in the drawing and consists of a curved semi-cylindrical stake with a beveled point H and lateral prong l0 formed by punching outward a portion of the back as indicated in Figs. 4, 5, and 6. The prong may be otherwise formed.

The open side of this stake fits over the nut l and is guided thereby while being driven down- Ward until the prong engages the strap surrounding the V-strip, or otherwise, and when thus embracing the nut the stake is held against displacement sidewise.

The strip and the leg of the support being thus held close to the inner face of the form, are

not separated from it by any concrete getting down between such faces in contact as above described. Therefore, when the concrete has set and the form is removed, the key strip and my support therefor, is exposed as shown in Figs. 1

and 2. It is common practice in other forms of key supports, to drive a chisel or crowbar into the key strip in order to pry it out of its groove. My method provides a better way in which the key strip is preserved in its undamaged condition. In the foot extending from the bottom of the leg of my support, I provide a hole l2 which is exposed to view upon removal of the form as above stated. A pointed rod inserted in this hole 12, allows of springing outward the leg and V- strip secured to the top of the support without actual contact of any chisel or crowbar with the strip itself. By such means as I have just described, the wooden key strip is preserved in un-' damaged condition for continued use. The metal stake I have described, being driven below. the surface of the concrete slab remains in its position as set in the concrete and is not subject to removal. As stated above, the stake assists the foot 6 in holding down the key strip and the prong supplements the foot 6 in maintaining the key strip in proper position against the inner face of the adjacent form.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. The combination with a wooden key strip, of a support consisting of a fiat metal bar bent at its upper front end to embrace said strip and let in flush with the outer face of said strip, and then over the top, down behind, and under the strip, and then extending downward in the same vertical plane as the said upper front end forming a leg, and having a right-angled foot extending outward to be disposed under an adjacent form and support said strip from the ground.

2. The combination with a concrete key strip of a support secured at its upper end to said strip and extending downward to form a vertical leg the outer face of which leg is in the same plane as said strip to allow the strip to contact with an adjacent form, and having a right-angled foot extending outward at the grade surface pro- ,under an adjacent form to support said strip from the ground, and a stake to be driven adjacent said strip to press it against an adjacent form and having a lateral prong to hold down the key strip, substantially as described.

4. In combination with a key strip and a support therefor having a leg the lower end of which is adapted to engage the ground and having its upper end secured by a bolt through the strip with a nut on its rear end, of a semi-cylindrical stake embracing said nut and guided thereby when driven into the ground adjacent said strip to press said strip against an adjacent form.

5. In combination with means to support a key strip for concrete slabs, of a stake having a beveled point adapted to slant the stake toward the key strip while being driven into the ground, and having a lateral prong near its upper end adapted to engage and to hold down said strip and limit the depth driven, substantially as described.

6. The combination with a form for a concrete slab and a key strip disposed against the inner face of the form, of a concrete strip support consisting of a supporting bar adapted to be se.

cured to said strip and characterized by a verti-r cal leg having its outer face disposed substantially in the same plane as the inner face of said form and having at its lower end an outwardly projecting foot adapted to rest on the ground and support said key strip, in said position, substantially as described.

JAMES FRED BARTON.

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