US3374983A

US3374983A - Concrete form stripping valve

Info

Publication number: US3374983A
Application number: US478149A
Authority: US
Inventors: Eldridge R Garretson; William S Spurr; Chester L Ward
Original assignee: MOLDED GLASS CO
Current assignee: MOLDED GLASS CO
Priority date: 1965-08-09
Filing date: 1965-08-09
Publication date: 1968-03-26
Anticipated expiration: 1985-03-26

Description

March 26, 1968 E. R. GARRETSON ET AL. 3,374,983

CONCRETE FORM STRIPPING VALVE Filed Aug. 9, 1965 INVENTORS ELDR/DG'E R. GARRETSON WILLIAM S SPURR CHESTER L. WARD ATTOR YS United States Patent Ofiice 3,374,983 Patented Mar. 26, 1968 CONCRETE FORM STRIPPING VALVE Eldridge R. Garretson, North Kingsville, William S. Spurr,

Geneva, and Chester L. Ward, Ashtabula, Ohio, assignors to The Molded Glass Company, Ashtabula,

Ohio, a corporation of Ohio Filed Aug. 9, 1965, Ser. No. 478,149

8 Claims. (Cl. 249205) I ABSTRACT OF THE DISCLOSURE A valve for concrete molding form having a stripping aperture, such valve having a domed head and cylindrical stem, with the stem having an internal air passage from the free end to a point just beneath the head. The valve is inserted in the mold aperture and the stern has an external rib which will pass through the aperture by resilient deformation but engage With the underside for permanent assembly to the form in the normal use of the same.

This invention relates to a concrete form of the type which is stripped or separated from the set concrete shape formed by the same by supplying compressed air or other fluid to the interface of the form and the shape.

A well-known and widely used form of this type is the pan or dome employed in building construction to form waffleslab floors, and this use serves further to illustrate that an installation can be of considerable size and thus involve a very large number of individual forms to be handled, installed or applied, and finally stripped or removed. In such floor construction, the pans are inverted to form downwardly open recesses at the underside of the floor, and they are provided with generally central apertures in their uppermost bottom walls for the noted air stripping. The apertures or blow holes must be shielded in one manner or another to prevent clogging or blockage by the concrete slurry poured against the pans, while permitting and facilitatingthe initial entry of the air applied under pressure from below between the pan and the overlying concrete shape.

It isthus known, as shown by US. Patent No. 2,850,- 785, to make such a pan with an internal nipple at the aperture, to receive the compressed air line nozzle, and provide an adhesive patch to be applied externally over the aperture, with the patch being of rough or irregular character so that the contact with the pan surface around the aperture is intermittent and the dic'sontinuities effectively provide passages for the discharge of air from about the periphery of the patch and hence to-the interface of the pan and the concrete shape. This practice requires that there be a separate supply ofpatches available at the particular work location, and the application thereof to the individual pans=in the installation prior to pouring constitutes a separate operation to be performed. More recently, such concrete forming pans or domes have been made with simple apertures, that is, without attached or integral nipples, and, molded plastic plugs of various configurations have. been employed in lieu of the noted adhesive patches. Such plugs have generally been in the form of thin domes with fluted or non-cylindrical stems, as shownby'U.S. Patent No. 3,151,374, these stems being adapted to be temporarily inserted through the apertures with the protective domes externally shielding the apertures. Such stem may have some force engagement with the pan in the aperture, but the assembly is nevertheless still temporary, the stem requiring its noted irregular shape to permit passage of the compressed air from the inside to the outside of the pan in use and ready to be stripped. Not only are these plugs thus also of impermanent assembly, they further equally constitute a second component source to be supplied and handled in much the same manner as the adhesive patches.

The plug type of shield has also proved to be rather erratic in its performance, with some provision usually made to facilitate the initial entry of the air beneath the dome portion for efficient air stripping, so that the plug will in this sense be equivalent to the crinkled or irregular adhesive patch as above noted. The underside of the dome in such a plug has therefore been made with projections in a variety of configurations serving to space portions of the dome and thereby define air escape or discharge passages. The known plugs of this class, however, have not proved to be wholly satisfactory and reliable, and their use in any event still inherently involves a separate supply and handling in view of the temporary nature of their association with the forming pans.

It is a primary object of this invention to provide an improved assembly of concrete forming pan and the like and a permanently associated valve device for stripping in the manner discussed. The permanent character of this assembly has been shown to greatly simplify the use of the forms, for example, in the noted waflle slab forming operation where the number of pans or domes employed is very considerable, especially in regard to actual time on the job. The valve devices can thus be associated with the pans conveniently at a storage or other supply location, without any further operation in the actual placement of the pans in the forming installation of the same, there being no chance of accidental dislodgement of the devices as assembled with the pans.

Another object of the invention is to provide an assembly of a concrete forming pan and valve device as set forth in which the mechanical design of the latter is such to assure uniform proper performance over long periods of use. The valve device, nevertheless, can very readily and economically be manufactured.

It is also an object of the present invention to provide such a valve device which is capable of use in association with concrete form apertures of varying extent or, in other words, with forms of different wall thicknesses at the aperture portions thereof. A

Other objects and adavntages of the present invention will become apparent as the following description proceeds.

To the accomplishment of the foregoing and related ends the invention, then comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawing setting forth in detail a certain illustrative embodiment of the invention, this being indicative, however, of but one of the various ways in which the principle of the invention may be employed.

In said annexed drawing:

FIG. 1 is a perspective view, on a relatively reduced scale, of a typical concrete forming pan equipped with a stripping valve in accordance with the present invention;

FIG. 2 is a vertical sectional view of the pan through the valve, with this view fragmented for convenience;

FIG. 3 is an elevation of the valve device separate from the pan; and

FIG. 4 is a bottom plan view of such valve device.

Referring now to the drawing in detail, the concrete form designated generally by reference numeral 10 is a pan or dome of the type commonly used for example in forming waffle slab floors in building construction. This pan has a peripheral flange 11 for support and attachment in the particular operative disposition desired, and the actual bottom 12 of the pan in the floor example at least will be uppermost. Insofar as the present invention is concerned, the material of which the pan is made is not important and any suitable material can be used, such as metal or fiber reinforced plastic, both of which are presently employed for the purpose.

There is a central aperture provided in the pan bottom 12, and a valve device designated generally by reference numeral 13 is assembled with the pan at such aperture. Valve device 13 should preferably be made of a durable, corrosion-resistant, and resilient material, such as neoprene rubber, which has been found to be quite satisfactory in these respects and lends itself to ready manufacture of the valve by conventional molding techniques.

This valve device, more particularly, comprises a circular head portion 14, which can be slightly convex as shown, for a reason to be later explained, and a stem portion 15 as an integral central extension of reduced size. Stem portion 15 is cylindrical and provided with a continuous external rib 16 at a predetermined distance along the length of such portion from that end thereof joined to the head portion 14. The other end of the stem portion is preferably provided with a recess 17 as illustrated and there is an axial cylindrical passage 18 extending from such free or exposed end recess substantially the full length of the stem portion to intercept a lateral passage 19 of generally rectangular cross section extending completely diametrically through the stem portion, whereby communication is provided from the free end of the valve stem portion to a pair of diametrically opposite outlets approximately at the other end or the juncture with the head portion.

The manner in which the valve device 13 is attached to the pan is believed evident from FIG. 2, and it will be appreciated that this attachment is not difficult to accomplish in view of the resiliently deformable character of the valve body. The location of the stem portion rib 16 is such to engage with the inner surface of the pan bottom 12 about the aperture therein when the head portion 14 is engaged against the exterior of the bottom, as shown, with some degree of resilient opposition serving to help maintain the valve device in the desired normally permanent association with the pan. The slightly convex shape of the head portion will permit this valve device to be thus assembled with pans of varying thickness without impairing the permanent character of the assembly, and it will be further apparent that the ends of the lateral passage 19 are approximately at the outer surface of the pan bottom.

Since the manner of use of such a concrete forming pan is well-known, no illustration of a concrete shape has been included in the drawing, it being sutficient for the purpose to note again that the pan in the floor construction use will be supported in inverted condition as shown in FIG. 1, whereby the head portion of the valve device is at the top where it will be covered by the poured concrete slurry. The aperture or blow hole is effectively sealed about the lip of the head portion. After the concrete has set sufliciently for stripping of the pan, the workman places the nozzle of a compressed air line against the end of the stem portion, the recessed formation of the latter assisting such application, and air is then forced through the

passages

18 and 19 to discharge at the ends of the latter. The air thus supplied will effectively break the peripheral seal by pressure deformation of the edge or lip to escape along the outer surface of the pan bottom or between the bottom and the formed concrete shape and thus force the pan from the shape.

It will be noted thatthe stem of the valve device is of approximately the same size as the pan aperture, such.

hollow stern being readily compressible by hand for insertion therein, and the head is of radially outwardly tapering thickness to provide a quite thin sealing edge or lip. The convexity of the head is not critical to performance and could be eliminated if desired, whereby the underside of this portion would be flat.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims or the equivalent of such be employed.

We, therefore, particularly point out and distinctly claim as our invention:

1. In a molding form for concrete and the like having a fluid stripping aperture, a valve device at the aperture of said form, said valve device comprising a head portion and a cylindrical stem portion of relatively reduced size extending generally centrally from the head portion, both said head and stem portions being made of a resiliently deformable material, the stem portion passing through the aperture and the head portion overlying the exterior of the form and obscuring the aperture, and locking means for maintaining the valve device normally permanently in such association with the form in use of the latter, the

' stem portion having an internal air passageway extendholding means is an integral part of the resilient stem portion.

3. The combination set forth'in claim 1, wherein the head portion is generally convex, with the stem portion 7 extending interiorly therefrom.

4. The combination set forth in claim 1, wherein the holding means is a peripheral projection on the stem portion and is engaged with the interior of the form about the aperture in resilient opposition to the engagement of the head portion with the exterior of the form.

5. The combination set forth in claim 1, wherein the free end of the stem portion is provided with a recess to receive an air nozzle, and said passageway includes an axial length in communication with said recess.

6. The combination set forth in claim 1, wherein said air passageway comprises an axial length extending from the exposed free end of the stem portion and a connecting lateral length which extends from said axial length to said outlet.

7. The combination set forth in claim 1, wherein said air passageway comprises a lateral section extending transversely through the stem portion with its ends generally in diametric opposition, and a connecting longitudinal section extends from an intersection with the lateral section to the free end of the stem portion.

8. The combination set forth inclaim 7, wherein the holding means is a peripheral projection on the stem portion and so located therealong as to engage the form interior about the aperture in resilient opposition to the head portion engagement with the form exterior.

References Cited UNITED STATES PATENTS 1,522,780 1/ 1925 Hennessy.

1,983,757 12/1934 Hick.

2,148,084 2/ 1939 Nock.

2,850,785 9/1958 Rushing 249--66 X 2,886,876 5/1959 Wilson 25-120X 3,151,374 10/1964 Kersten 249-187 WILLIAM J. STEPHENSON, Primary Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,374,983 March 26, 1968 Eldridge R. Garretson et a1.

It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

In the heading to the printed specification, line 5, for "The Molded Glass Company," read The Molded Fiber Glass Company,

Signed and sealed this 8th day of July 1969.

iEAL) ttest:

iward M. Fletcher, Jr. WILLIAM E. SCHUYLER, JR.

ttesting Officer Commissioner of Patents