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Publication numberUS948539 A
Publication typeGrant
Publication dateFeb 8, 1910
Filing dateDec 2, 1908
Priority dateDec 2, 1908
Publication numberUS 948539 A, US 948539A, US-A-948539, US948539 A, US948539A
InventorsTheodore Ellsworth Clark
Original AssigneeTheodore Ellsworth Clark
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Mold for sewers.
US 948539 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)



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Patented Feb. 8, 1910.

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To all whom it may concern:

Be it known that I, THEODORE ELLswonTi-i CLARK, a citizen of the United States, residing at Sacramento, in the county of Sacramento and State of California, have invented new and useful Improvements in Molds for Sewers, of which the following is a speciication.

My invention relates to improvements in molds for sewers, conduits, water-pipes, culverts and other tubular structures of the kind which are constructed of cement, concrete, brick, or other suitable materials, and the object of my invention is to provide a contractible sewer-mold that may easily be set up and conveniently removed from the sewer-pipe or conduit after the said pipe has been constructed about it. I attain this and other objects by the mechanism described in this specification and illustrated in the accompanying drawings which form part thereof and in which similar letters or figures refer to similar parts throughout.

Figure lis a longitudinal sectional view in part of the sewer-mold forming' the basis of my invention. Fig. 2 is a transversev sectional view of the same on the dotted line 0 0. Fig. 3 is an end view of the same and Figs. 4t and 5 are side views of Fig. 3. Fig. G is a longitudinal sectional view in part of the sewer-mold in its contracted form. Fig. 7 is a transverse sectional view of the same at the point indicated by the dotted line 0-0. Fig. 8 is a side view of the upper or semi-circular form or mold which is used in connection with the contractible mold in forming the upper half of sewer-pipes, conduits etc. Fig. 9 is a transverse sectional view of Fig. 8. Fig. 10 is a transverse sectional view of a trench showing a sewer-pipe or conduit partly constructed about the sewer-mold and showing the semi-circular mold Fig. 8 in position leaving a space between it and the sewer-mold ready to be filled with concrete or other mixture.

Having thus described the several views, I will now explain more in detail the various parts. In Figs. l and 2, P is a sheet-steel or iron circular tube or pipe with its longitudinal seam unriveted or unfastened together, one edge overlapping the other as shown in the upper part of Fig. 2. This sewer-mold may be any desired length con-4 sistent with the facility with which it may be handled; for pipes of ordinary diameter, I employ molds twenty to thirty feet long.

Specification of Letters Patent.

Application filed December 2, 1908.

Fatented Feb. 3, 1910.

Serial No. 465,660.

In the several views, 3 is a rod extending the full length of the mold, one end beingconstructed as shown with recesses R and S and an eye T. Upon the rod 3 are hubs 2 having forked projections 2 to receive the arms l which are rotatably secured to lugs B at o-ne end and to the forked projections at the other by rivets or bolts B. B are lugs which are riveted or bolted to the inner surface of the sheet-iron mold and which receive one end of the arms l. The hubs 2 are securely fastened to the rod 3 by set-screws C or other suitable means. There may be any number of arms l with corresponding lugs B and projections 2 as may be desired, reference being had to the diameter of the mold. I show only four to each hub for the sake of illustration. This combination of hubs 2, arms l, lugs B and rod 3 form toggle-joints which, when the rod 3 is drawn out, causes the sheet-iron mold P to be contracted and assume a smaller diameter as shown in Figs. 6 and 7. There may be any number of these toggle-joints, reference being had to the length of the mold.

In order that the arms l may retain their position at right angles to the rod 3 as shown in Fig. l, a bar LL, Fig. 3, is dropped into the recess S, said bar extending across the mold, one end being rotatably connected to one edge of the mold I by the lug 6 (sec Fig. 5) and the other end dropped into the catch 5 (see Fig. 4) secured to the diametrical opposite edge of the mold. By this arrangement, a simple yet effective means is provided for holding the rod 3 in a fixed position so that the toggle-joints may not operate and cause a diminution of the diameter of the sewer-mold when a sewer-pipe is being constructed about it. When it is desired to remove the sewer-mold from the inside of a conduit which has been constructed about it, the rod 3 is partly drawn out by pulling on the eye T and the bar 4 dropped into the recess R. The act of drawing out the bar 3 causes the several toggle-joints to act simultaneously in contracting the diameter of the mold as indicated in Figs. 6 and 7 one edge lapping over the other as indicated in the upper part of Fig. 7. When the sewer-mold has been contracted, it may readily be removed from the sewer-pipe or conduit and placed in position ready for the construction of another portion or section of sewer, the mold, after hav- REIS Sill ing been withdrawn, having been enlarged [struction of other tubular bodies such as again to its original diameter by forcing conduits,

back the rod 3 into the position indicated in Fig. l.

For the purpose of stiiiening the edges of the mold where they overlap, bars of angle iron A A or other suitable shape are riveted or fastened to the inner surface of the mold as indicated.

ln connection with the inner form or mold Fig. l, an outer form Figs. 8 and 9 may be used, especially where large pipes are t0 be constructed, although with pipes of small diameter I discard its use altogether. This form consists of two curved pieces of sheetsteel or iron 9 9 joined together by arched braces T-J, leaving a space lengthwise between the inner edges through which cement or other building material may be passed. On the inner surface and at one end are placed lugs 8-8 extending inwardly which keep the semi-circular forni a speciiied distance from the inner mold, see Fig. l0.

This form is made preferably of short length, say four to six feet, and as fast as the cement or other building material is tamped between it and the sewer-mold, it is moved along, one end resting on the top of the sewer already formed and the other end held in place by the lugs 8 resting on the top of the inner form.

In the construction of these molds, it will be noted that various changes may be made in the details without in any way sacriiicing any of the advantages of this invention or departing from the spirit thereof.

ln describing and claiming my invention as a sewer-mold l do not desire to limit its use specifically to such, but it is adapted to be used as stated in the preamble to the conwater-pipes etc. whether constructed of cement, concrete, brick or other building materials. I may state also that with the sewer-mold described in this invention, it is possible to use reinforcing bars or rings in the construction of sewers, conduits, etc.

Having thus described my invention, what l claim as new and desire by Letters Patent to secure, is-

l. In combination with a contractible metallic sewer-mold, a retaining' bar extending across the end of said mold, one end being rotatably secured to one edge of the mold by a lug` or other suitable means and the opposite end adapted to engage in a catch secured to the diametrical opposite edge of the mold, and a recess or recesses on the end of the centrally located rod adaptedto receive the middle section of the retaining bar, the combination forming means of preventing the said centrally located rod from moving forward or backward longitudinally except when required.

2. In combination with a sewer-mold, an-

other mold consisting of two curved members joined together by braces in such a manner that a longitudinal opening is left between the inner edges of said curved members through which the material of which the sewer is constructed may be passed, said curved members being provided on their inner faces at one end with lugs or braces extending inwardly representing the thickness of the sewer-walls.


Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3338546 *Jan 25, 1965Aug 29, 1967Revilo FullerCollapsible self-supporting core
US5290006 *May 20, 1992Mar 1, 1994Clifford GoukerExpanding form for pouring mixed cement to reposition manhole castings
US5934820 *May 14, 1998Aug 10, 1999Hinkle; Vernon W.Manhole collar assembly and method for producing same
US6161985 *Oct 15, 1998Dec 19, 2000Vernon W. HinkleManhole collar assembly
US6869249 *Oct 23, 2003Mar 22, 2005Stephen CalhoonAdjusting device for installing a manhole ring onto a manhole
Cooperative ClassificationB28B7/168, E04G11/02