US3916590A

US3916590A - Pulling iron

Info

Publication number: US3916590A
Application number: US534508A
Authority: US
Inventors: Arthur C Miller
Original assignee: Individual
Current assignee: Individual
Priority date: 1974-12-19
Filing date: 1974-12-19
Publication date: 1975-11-04
Anticipated expiration: 1992-11-04
Also published as: CA1010674A

Abstract

A pulling iron adapted to be partially embedded in an underground vault has a loop of steel cable wherein the legs and bight portion of the loop are coated with a polymeric plastic material. Each leg has an extension disposed at an angle with respect thereto to facilitate connection thereof to rebars. The coating on each leg is integral in one piece with a mold plate extending across the loop.

Description

O Umted States Patent [191 [111 3,916,590

Miller Nov. 4, 1975 PULLING IRON 3,420,014 1/1969 Courtois et al. 52/125 x 3,431,012 3/1969 Courtois et a]. 52/125 X [76] Inventor- Arthur Mlue" Concrete 3,562,979 2/1971 Ali-Oglu 52/125 Products, Inc., Rte. 29, Devault, Pa. 19432 Primary Examiner-J. Karl Bell [22] Filed: Dec. 19, 1974 Attorney, Agent, or Firm-Seidel, Gonda & 21 Appl. No.2 534,508 Gddhamme 52 U S Cl [57] ABSTRACT 1 52/125 A pulling iron adapted to be partially embedded in an [51] Int. Cl. E04H 13/00 d d l h l f l bl h [58] Field of Search 52/125, 128, 142, 133, Y a ca e W the legs and bight port1on of the loop are coated wlth 52/124 a polymerlc plastlc matenal. Each leg has an extension disposed at an angle with respect thereto to facilitate [56] References Cited connection thereof to rebars. The coating on each leg UNITED STATES PATENTS is integral in one piece with a mold plate extending 2,794,336 6/1957 Ballou 52/125 X across the 1001; 3,l24,385 3/1964 Neptune 52/125 X 3,263,378 8/1966 Dorris 52 125 x 11 Clams, 4 Drawmg Figures US. Patent Nov. 4, 1975 3,916,590

PULLING IRON BACKGROUND Pulling irons are per se old in the art of concrete reinforced underground vaults. Such vaults are generally made of two or more pieces coupled together. See FIG. 6 of Pat. No. 3,263,378 wherein the pulling irons are located in or near the bottom wall of the vault. Wires to be joined within the vault are looped through the pullmg II'OI'IS.

Present pulling irons are usually zinc coated steel and weigh approximately pounds. The zinc coating is easily damaged by hooks which engage the loop of the pulling irons and otherwise have a very limited lifetime. The underground vaults usually have water in them so that the pulling irons in an existing vault are usually rusty.

Use of the present pulling irons as described above requires a removeable plate on the steel forms used for casting the vault or components thereof. Before the concrete vault can be stripped from the forms, the plate must be removed.

The pulling iron of the present invention is adapted to be partially embedded in a wall of an underground vault such as the bottom wall thereof. The pulling iron is in the form of a loop of steel cable having legs extending from a bight portion. Each leg has an extension disposed at an angle with respect thereto to facilitate connection of the pulling iron to a rebar.

A polymeric plastic coating is provided on each leg so as to encase the bight portion and at least a part of the legs. The coating covers all portions of the pulling iron loop adapted to be exposed when the pulling iron is partially embedded in a wall of the underground vault.

In the preferred embodiment of the present invention, a surface plate is molded integrally with the coating on the legs of the loopvand extends between the legs of the loop. The surface plate is of sufficient size so that it may overlie the slot in a metal castirig form. The coated loop extends through the slot in the metal form while the surface plate overlies the entire slot in said form during casting of the vault. The surface plate is preferably provided with projections for properly aligning the plate with the slot in the casting form and to prevent the loop from tilting during casting of the vault.

It is an object of the present invention to provide a novel pulling iron which is stronger and less expensive than those utilized heretofore, while being lighter in weight and noncorrosive.

Other objects will appear hereinafter.

For the purpose of illustrating the invention, there is shown in the drawings a form which is presently preferred; it being understood, however, that this invention is not limited to the precise arrangements and instrumentalities shown.

FIG. 1 is a vertical sectional view through an underground vault.

FIG. 2 is a perspective view ofa pulling iron in accordance with the present invention.

FIG. 3 is an enlarged detail view of steel forms in which the bottom wall of the vault shown in FIG. 1 is being cast.

FIG. 4 is a partial plan view taken along the line 4-4 in FIG. 3.

Referring to the drawing in detail, wherein like numerals indicate like elements, there is shown in FIG. 1

a concrete reinforced underground vault of a simplified construction having a manhole 12 to facilitate entry thereinto. The vault 10 includes a bottom wall 14 containing one or more of the pulling irons l6 partially embedded therein. A wire way or conduit 18 for wires communicates with the interior of the vault 10 through a vertical side wall thereof. If desired, another conduit 20 may communicate with another one of the side walls of the vault l0. Wires to be joined within the vault 10 enter the same through the conduit 18 and/or 20.

The pulling iron 16 is embedded in or near the bottom wall 14 of the vault 10. The pulling iron 16 includes a bight portion 22 from which extends

legs

24 and 26 of a steel cable. Leg 24 terminates in an angled extension 28 while leg 26 terminates in an angled extension 30. The steel cable is preferably a rigid cable having seven or eight strands and which complies with ASTM Designation: A4l6-68 so as to have a minimum ultimate strength of 250,000 psi based on the nominal area of the strand. In a seven strand cable, there is a center wire enclosed tightly by six helically placed outer wires with a uniform pitch of not less than 12 and not more than 16 times the nominal diameter of the strand.

The bight portion 22 and any portion of the

legs

24 and 26 adapted to be exposed when the pulling iron 16 is embedded in the vault 10, are provided with a coating 32 of polymeric plastic material. It will be noted that the coating 32 is thicker on the inside of the bight portion 22. Otherwise the coating 32 is of uniform thickness. I have found a suitable thickness for coating 32 to be one-eighth of an inch.

The coating 32 may be a wide variety of polymeric plastic materials which are hard, rigid, strong, tough and resilient, dimensionally stable under exposure to moisture and heat, resistant to chemicals, high strength, and which are a substantially non-hygroscopic (have a water absorption of less than l%/24 hours). I prefer to use a highly crystalline acetal copolymer sold commercially under the trademark Celcon, having a water absorption of 0.41%[24 hours; tensile strength of 10,000 psi; elongation 15%; flexural strength 14,000 psi; and shear strength of 9,500 psi.

Due to the fact that the cable has an irregular surface, a nonrotatable coating 32 may be applied thereto with a good bond between the cable and the coating, The irregular surface of the cable also facilitates a good bond with the concrete in which it is to be embedded as described hereinafter.

The coating 32 terminates in radially outwardly directed

flanges

34 and 36 on the

legs

24 and 26 respectively. The

flanges

34 and 36 act as barriers for any water or moisture which tends to follow the seam between the concrete and the coating 32. The coating 32 on leg 24 is preferably integral in one piece with the coating 32 on the leg 26 by way of a surface plate 38. Thus, coating 32 and plate 38 are molded onto the cable at the same time. Plate 38 is provided with a plurality of projections such as

projections

40, 42 and 44. The projections are integral with the plate and are spaced inwardly from the periphery of plate 38 as shown more clearly in FIG. 2. The projections have a height of about 1% inch, a thickness of about one-eighth inch, and a width corresponding to the diameter of the coated loop as shown more clearly in FIG. 4.

The components of the vault 10 are cast using metal casting forms including the inner form plate 46 and an outer plate form 48. Before concrete 56 is poured into the space between the

form plates

46 and 48, the loop of the pulling iron 16 is inserted through the slot 54 in the plate '46. The plate 38 overlies the peripheral portion on the plate 46 around the slot 54. The distance between

projections

40 and 44 corresponds to the length of the slot so as to properly orientate the loop of the pulling iron with respect to the slot. Each of the projections 40-44 extends through the slot 54 and maintains the loop perpendicular to the plane of the plate 46. The loop should not tilt during the introduction of concrete 56 into the space between the

form plates

46, 48.

The exposed portion of the

legs

24, 26 and/or the

extensions

28, 30 are rigidly connected to transverse rebars 50 and/or longitudinally extending rebars 52. Hence, the pulling iron 16 is an integral part of the reinforcing steel for the vault 10. The

extensions

28 and 30 need not be angled upwardly in FIG. 4 but rather may extend horizontally in FIG. 4.

It will be noted that there is no separate plate to be removed as part of the casting forms in order to accomodate the pulling iron 16. When the

form plates

46, 48 are stripped, the plate 38 remains as a part of the vault flush with the wall of the vault except for the projections 40-44 which may remain or may be removed with a grinder if desired.

While the above described polymeric plastic is preferred as the material for coating 32 and plate 38, other thermoplastic materials capable of being injection molded may be used. For example, an acetal resin sold under the trademark DELRIN may be used. The coating 32 has a smooth outer periphery but its inner periphery enters the crevices between adjacent peripheral strands of the cable so as to be non-rotatable with respect to the cable.

Dimensions can vary depending on the size of the vault. The following are exemplary by way of example and not by way of limitation: the included angle between

legs

24, 26 is 52, the cable has a diameter of one-half inch, coating 32 is one-eighth inch except for the inner side of bight portion 22 which is one-fourth inch, plate 38 is 3/32 inch, the

extensions

28, 30 are about 6 inches long and perpendicular to their respective legs, and plate 38 is connected to

legs

24, 26 at their midpoint about 4 inches from bight portion 22. The included angle between

legs

24, 26 is usually 4565.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification as indicating the scope of the invention.

I claim:

1. A pulling iron adapted to be partially embedded in an underground vault comprising a loop of steel strandtype cable, said loop having legs extending from a bight portion, each leg having an extension disposed at an angle with respect thereto to facilitate connection thereof to rebars, said bight portion and at least a portion of each leg being encased in a coating of polymeric plastic material, said coating covering all portions of said loop adapted to be exposed when the loop is partially embedded in a wall of a vault, said coating being a tough plastic material which has substantially no ab- 4 sorption with respect to water and oil, said coating being non-rotatable with respect to said cable.

2. A pulling iron in accordance with claim 1 including a plate extending across said legs, said plate being integral in one piece with the coating on said legs at a location where the legs are adapted to emerge from a wall of a vault whereby the plate will be substantially flush with a wall of the vault, said plate being of the same material as said plastic material.

3. A pulling iron in accordance with claim 2 wherein said steel cable includes a center wire enclosed tightly by at least six helically placed outer wires and has a minimum ultimate strength of at least 250,000 psi.

4. A pulling iron in accordance with claim 2 including a plurality of projections on one surface of said plate, said projections extending away from said plate toward the bight portion of said loop.

5. A pulling iron in accordance with claim 2 wherein the'coating on said legs terminates in a radially outwardly extending protuberance, said plate being connected to said coating between said bight portion and said protuberances.

6. A pulling iron in accordance with claim 1, a concrete reinforced vault having a bottom wall, said pulling iron being embedded in said vault bottom wall, said loop and plate being exposed, said plate being substantially flush with the surface of said bottom wall.

7. A pulling iron comprising a loop of steel strandtype cable, said loop having legs extending from a bight portion, each leg having an extension disposed at an angle with respect thereto, a polymeric plastic coating on said bight portion and on at least a substantial portion of each leg, a plate-like member extending between said legs, said plate-like member being integral with and of the same material as said plastic coating, said plastic coating being a tough plastic material having a water absorbency of less than l%/24 hours.

8. A pulling iron in accordance with claim 7 wherein said coating on said bight portion and legs extends into crevices between adjacent peripheral strands of said cable to render the coating non-rotatable with respect to said cable.

9. A pulling iron in accordance with claim 8 wherein said plastic coating on said bight portion and legs is of substantially uniform thickness except for the inner side of the bight portion which is thicker than the remainder of the coating.

10. A pulling iron comprising a loop of metal strand cable having a center wire enclosed tightly by a plurality of helically placed outer wires, said loop having a bight portion from which a pair of legs extends, each leg having an extension disposed at an angle with respect thereto, a polymeric plastic coating on said bight portion and extending along a portion of each leg, the remaining portion of each leg and each extension being free from any coating, said coating extending into crevices between adjacent peripheral strands of said cable so that the coating is non-rotatable with respect to the cable.

11. A pulling iron in accordance with claim 10 including a plate-like member integral with said coating and extending between said legs, said member being wider than the diameter of said coated loop.

Claims

1. A pulling iron adapted to be partially embedded in an underground vault comprising a loop of steel strand-type cable, said loop having legs extending from a bight portion, each leg having an extension disposed at an angle with respect thereto to facilitate connection thereof to rebars, said bight portion and at least a portion of each leg being encased in a coating of polymeric plastic material, said coating covering all portions of said loop adapted to be exposed when the loop is partially embedded in a wall of a vault, said coating being a tough plastic material which has substantially no absorption with respect to water and oil, said coating being non-rotatable with respect to said cable.

5. A pulling irOn in accordance with claim 2 wherein the coating on said legs terminates in a radially outwardly extending protuberance, said plate being connected to said coating between said bight portion and said protuberances.

7. A pulling iron comprising a loop of steel strand-type cable, said loop having legs extending from a bight portion, each leg having an extension disposed at an angle with respect thereto, a polymeric plastic coating on said bight portion and on at least a substantial portion of each leg, a plate-like member extending between said legs, said plate-like member being integral with and of the same material as said plastic coating, said plastic coating being a tough plastic material having a water absorbency of less than 1%/24 hours.