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Publication numberUS2959198 A
Publication typeGrant
Publication dateNov 8, 1960
Filing dateApr 5, 1956
Priority dateApr 5, 1956
Publication numberUS 2959198 A, US 2959198A, US-A-2959198, US2959198 A, US2959198A
InventorsBjork Wilbur E
Original AssigneeBjork Wilbur E
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Water shut off box cap
US 2959198 A
Abstract  available in
Previous page
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Claims  available in
Description  (OCR text may contain errors)

Nov. 8, 1960 w. E. BJORK 2,959,198

WATER SHUT oFF Box CAP Filed April 5, 195e @fing/727mg United States Patent WATER SHUT OFF BOX CAP Wilbur E. Bjork, 4040 12th St., Des Moines, Iowa Filed Apr. 5, 1956, Ser. No. 576,489

2 Claims. (Cl. 13S-89) This invention is a cap or covering for the ground surface or sub ground surface opening of the pipe giving access to the outdoor shut oli valve of a water system. It features structure for holding it in place by friction rather than by threads and is provided with a tough core of high tensile strength.

Prior to my invention, the caps of these pipes leading to the shut off valve box have been threaded on the inside to match mating threads on the outside top of the pipe. This thread system has been very satisfactory from the point of view of keeping the plug or cap in place. AS both the pipe and the cap are made of cast iron, however, they usually rust together when left for any substantial period of time. When the cap and threads of the pipe are both rusted, removing the cap from the pipe is often a rather difficult job. In fact considerable time can be consumed in merely getting the cap otf the pipe. Usually the desire to operate the valve is to shut olf the water in order to repair damage to the system. As this cannot be carried on until the valve is closed, operating the valve is often an emergency situation of more or less gravity. Time lost in operating the valve is, therefore, important.

While it might be possible to make the pipe and cap of some material other than cast iron, this material is used for outdoor fittings. It is rather hard which makes it wear well when installed in sidewalks or streets. It is relatively inexpensive compared to other possible materials. Also since it is a magnetic material and will respond to a magnet, a compass will aid in locating rapidly a unit that for one reason or another is not visible to the eye.

Not only is this known form of cap hard to remove, but also often requires that the top of the pipe be rethreaded before the cap can be screwed into position to cover the valve box after the water has been turned on again. Such a rethreading job is not diicult when the pipe is located in the ground. In some cases, as when the shut off box is in a business area, the shutoff is located beneath a pavement or sidewalk. When such is the case, and the end of the pipe must be rethreaded, the work becomes involved. The rethreading die is powered by a workman using a rather long handle or die stock as it is known. Since the top of the pipe is always recessed in the street or sidewalk, for obvious reasons, a substantial portion of `the pavement or walk must be removed to provide room for the operation of the die stock. When the work is completed, this paving material must be replaced. If this work can be avoided, it would save much time for the workman and inconvenience for other persons desiring to use the area.

While it is not of great consequence, it should also be noted that casting the conventional type cap and machining the threads into it involve more time and labor than is necessary in the construction of my improved cap as will appear hereafter.

Accordingly it is the principal object of my invention to provide a novel water shut ofi box cap; one that:

(1) Is easily made at a relatively low cost.

I from its fitting down inside the pipe.


(2) Is easily installed on and removed from the pipe it caps.

(3) Avoids much of the maintenance work necessitated by the use of conventional caps.

(4) Is secured by friction to the pipe it caps to resist accidental displacement or removal by tampering by unauthorized persons.

While the foregoing specific objects are the main ones of this invention, it is my intention Ito include as objects hereof any such as may be clear to a person skilled in this art after he has read this specification and examined the drawings herewith which are briey described as follows:

Fig. 1 is a perspective view of the cap;

Fig. 2 is a vertical sectional view of the cap and Fig. 3 is a side elvation of the cap shown positioned in a vertical section of a fragment of a pipe leading to a water shut oi box.

Referring to the drawings, the cap invention is seen to consist of a tapered plug 10 cast integrally with an overhanging ange 12. The taper of the plug is not critical, but it should be gradual enough to effect a pronounced Wedging of the cap into the top of the pipe 14 in Fig. 3 when the plug is forced down into the pipe. The size of the plug is such that i-t can be forced down into the pipe so that the ange 12 is approximately onequarter (1A) of an inch from the top of the pipe 14 when the latter has its usual inside diameter. Flange 12 is provided with lthe usual grooves 16 to receive the end of a conventional key 18 for turning the conventional type of cap. When used with my cap, the key can be used conventionally to apply turning motion. A particularly stubborn cap may be tapped gently with a hammer on the side of the flange 12. Such tapping will usually loosen a cap that cannot be loosened by the use of the key 18 alone.

The only hazard in using my improved cap results It is possible in removing the cap to break off a piece of it which may fall down into the pipe or box in which the shut ol valve is located. If the piece so falling is large enough, it could make it difficult or impossible to operate the valve without digging up the entire installation and removing the broken portion of the cap. In order to minimize the likelihood of such an occurrence, the plug is preferably cast around a core having a much greater tensile strength than cast iron. In Fig. 2 this core 20 is shown extending the length. of the device vertically and is preferably of steel. In the event that some other material than cast iron is used for the cap, the core is still advisable and it will then serve the dual purpose of providing strength and a magnetizable substance to aid in locating hidden cap by means of a magnetic compass. In short, the core at least should be of a material that will attract a magnet.

While the device is made to lit a new pipe, or one that has retained its original inside diameter, it is worth noting that the cap is not intended to be water tight. The box in which the shut olf valve is located is not of water tight construction. It is intended merely to prevent extranous solids from fouling the operation of the valve. Consequently it is not important whether the cap is adapted to making a water tight seal on the pipe. Where the pipe is old and worn, therefore, so that the cap will not wedge tightly into the pipe but instead will rest with the ange 12 engaging the top of the pipe 14; the cap can be made to be secured in the pipe by friction by bending the pipe until the inside diameter of it a point near its top is smaller than the largest diameter of the tapered portion 10 of the cap. Also of course, the tapered cap has a diameter at its lower end, as installed, that is substantally smaller than the smallest inside diameter of the pipe even after the latter is bent. Clearly my cap can be used on old and worn pipes as, or nearly as, effectively as on ones having their originaldimensions.

I have disclosed my invention by drawings and a description of the preferred practical embodiment of it. I now point out with particularity what I believe to be my invention in the following claims.

I claim:

l. In an outdoor shut oir valve access pipe cap', a tapered smooth sided plug of cast iron; a flange of cast iron moulded on the larger end of said tapered plug; a strengthening core extending entirely through vertically said tapered plug whereby said pipe cap may be held in a pipe by friction; and removed without danger of major References Cited in the le of this patent UNITED STATES PATENTS 791,351 Malloy May 30, 1905 1,975,976 Robinson Oct. 9, 1934 2,225,205 Brooks Dec. 17, 1940 FOREIGN PATENTS 624,400 Great Britain lune 7, 1949 mi; Mw

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US791351 *Mar 11, 1905May 30, 1905John Mcwilliams FordFlue-plug.
US1975976 *Mar 11, 1933Oct 9, 1934Nat Electric Prod CorpUnderfloor duct outlet
US2225205 *Jun 27, 1938Dec 17, 1940Lisle CorpMagnetic plug
GB624400A * Title not available
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US5707344 *Apr 25, 1996Jan 13, 1998Olympus Optical Co., Ltd.Endoscope
U.S. Classification138/89, 215/355, 215/302
International ClassificationF16L55/10, F16L55/11
Cooperative ClassificationF16L55/11
European ClassificationF16L55/11