US3488907A

US3488907A - Rust protection and distance device for reinforcing rod chairs

Info

Publication number: US3488907A
Application number: US690450A
Authority: US
Inventors: Anders Bertil Aberg
Original assignee: Individual
Current assignee: Individual
Priority date: 1966-12-16
Filing date: 1967-12-14
Publication date: 1970-01-13
Anticipated expiration: 1987-01-13
Also published as: DE1659020A1; FR1547999A; SE321334B; GB1206189A

Description

Jan. 13, 1970 .A. B1ABERG 3,488,907

RUST PROTECTION ANDDISTANCE DEVICE FOR REINFORCING ROD CHAIRS Filed Dec. 14, 1967' I N VEN TOR A/zde/s' Berfz/ Abe/' United States Patent US. Cl. 52309 4 Claims ABSTRACT OF THE DISCLOSURE The disclosure relates to a rust protection and distance device for covering ends of reinforcing rod chair feet in concrete structures which, when pouring the concrete, are to rest against a mould. The device which according to the disclosure is made from plastics such as, polyethylenes, polypropylenes, polyvinylchlorides and polyamides constitutes a socket to be applied to the ends of the chair feet, the socket comprising a sleeve which is open at one end and closed at the other by a bottom portion. The cavity of the sleeve, has adjacent the bottom, a smaller cross section than the cross section of remaining portions of the cavity nearer to said open end. The sleeve has at least two mutually remote distance means protruding radially from the outer surface of the sleeve in at least one common direction radially of the sleeve.

BACKGROUND OF THE INVENTION The invention relates to an improved rust protection and distance device, in particular for concrete reinforcements. The purpose of such distance devices is to maintain horizontally disposed reinforcing rods at a predetermined distance from the form when pouring floors, slabs or the like, and a rust protection and distance socket constituting part of such distance device.

When mounting reinforcements for concrete constructions prior to pouring the concrete, and in particular when it is a question of heavy reinforcements, so called chairs made from round-iron pieces, the ends of which are bent so as to constitute feet defining a support of the chairs to provide a desired stability and surface of contact with the form, are used to support reinforcing rods at a desired distance from the form. The ends of the round-iron pieces which constitute the feet of the chairs usually cause certain inconveniences as regards the final concrete construction, firstly due to the fact that wounds may appear in the concrete surface, secondly, due to the fact that the ends are apt to constitute an entrance for rust attacks on the reinforcement.

It is an object of my invention to provide a device 'by which said inconveniences are eliminated in a substantial degree and, to this end, relates to a rust protection and distance device constituting a socket for ends of rods supported by a concrete form when pouring the concrete, said device having properties as defined in one or more of the appended claims.

SUMMARY OF THE INVENTION According to the invention a rust protection and distance device of the kind described is substantially characterized by the fact that said device comprises a sleeve which is open at one end and closed at the other by a bottom portion, the cavity of the sleeve having adjacent the bottom a smaller cross section than the cross section of remaining portions of the cavity nearer to said open end, said sleeve having at least two mutually remote distance means protruding radially from the outer surface 3,488,907 Patented Jan. 13, 197( thereof in at least one common direction radially of thl sleeve axis.

Plastic materials suitable for the purpose are, by wet: of example, polyethylenes, polypropylenes, polyvinyl chlorides, polyamides.

-With a device as defined the result is attained, that ill! end of the rod constituting the chair is protected agains influences of humidity at the concrete surface, the contac with the concrete form when pouring being present at 2 number of restricted areas and by the intermediary of 2 material which is experienced to give rise to no or only insignificant marks in the poured concrete. When the socket cavity has a conical shape or has otherwise 2 somewhat larger diameter than the rod end introduced into the cavity, there will be an annular space between the socket and the rod, which, when tamping the concrete, is partially filled with concrete and protects the portion of the round-iron against rusting by influence oi humidity, which would otherwise possibly come into contact with the iron via a relatively short creep length.

Other objects, features and advantages of my invention will become apparent from the following description with reference to the drawings, in which:

' BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a side view of an embodiment of my invention and constituting a socket to be applied to the end of a round-iron rod bent to constitute a chair for a reinforcement rod, for instance,

DESCRIPTION OF A PREFERRED EMBODIMENT In FIGS. 1 and 2, the rust protection and distance device comprises a frusto-conical sleeve 1, the wider end of which is open and the smaller end of which is closed by a bottom 2, the device constituting a socket to be placed over the end of a rod of appropriate dimension. The slope of the walls of the sleeve can be rather small and need not be as large as illustrated in FIGS. 1 and 3 for illustrative purpose. With slope of the walls toward the axis of the sleeve as small as 0.2, corresponding to a difference in diameter of about 0.5 mm. for a length of the sleeve of 10 cm., the sleeve will be easily applicable to the end of a rod of appropriate dimension to be held thereon by coaction between the walls of the sleeve and the rods adjacent the closed ends of the sleeve. Chairs of this kind for reinforcement irons or other bar-shaped components to be enclosed by the poured concrete, are usually made from round-iron having a diameter of between 4 and 10 mm.

A number of distance means extend radially of the external surface of the sleeve. As illustrated in FIGS. 1 and 2, said distance means constitute annuluses 3, extending radially in the peripheral direction of the sleeve. Said rings protrude a distance of at least 0.5 and preferably 1-3 mm. and more from the external surface 4 of the sleeve. When the protection devices are placed onto'the legs of a chair as illustrated in FIG. 2 said rings as well constitute means for preventing humidity from migrating along the sleeves toward the reinforcement iron through the concrete along the legs of the chair.

3 lhe round-iron piece 5 is bent to a shape so as to convute a chair having two legs 6 and an intermediary vered portion 7 to support a reinforcement rod, the legs ling ends 8 which are bent out laterally and in opposite ections so as to define a support area of the chair on the Wild. The ends 8 have a tight fit in the sleeve at and acent the bottom 2 thereof, so that the sleeve is sefely held onto the chair. Due to the conical shape of sleeve, an annular space 10 is present between the eve and the round-iron 5 adjacent the open end 9 of the eve, said annular space to be filled with finely divided lcrete during tamping, said concrete providing for an reased creep length for humidity from the concrete "face to the portion of the round-iron inserted into the eve and not covered by a concrete layer protecting it ainst corrosion. FIG. 3 shows a modification of the protecting means lstrated in FIG. 1. In this embodiment, distance memrs 11 extend radially of the sleeve only along one side reof. In this embodiment the protection against creep humidity along the external wall of the sleeve is less .cient than with the embodiment according to FIG. 1. [n the embodiment illustrated in FIG. 4, the cavity of a sleeve has a cylindrical shape and has a constriction iacent the bottom 2 constituted by a rounded cam 12 to ld the protection device attached to the round-iron and one of the annuluses lateral holes 13 for nails to temrarily hold the chair attached to a form before and ring pouring, the nails being removed after removal of a form by pulling them out of the plastic socket. While this invention has been described with respect to :cific examples thereof, it should not be construed as ing limited thereto. Various modifications and substituns will be obvious to everyone skilled in the art and 1 be made without departing from the scope of this Iention. I claim: 7 1. .A chair for supporting reinforcing bars above the bstantially horizontal surface of a form comprising a rod :rnent formed into an inverted U-shaped structure havg a saddle for supporting a reinforcing bar, two bent mgate foot portions laterally spaced from each other id extending horizontally away from the plane of the U- aped portion of said structure in opposite directions and apted to overlie said form surface, and a rust protector r each foot portion comprising an integral molded prodt made of a synthetic resin having a body portion in the .4 form of an elongate hollow sleeve which is closed at one end, and a plurality of projections extending downwardly from the outer surface of said body portion for spacing said body portion above said horizontal form surface, the interior surface of said sleeve being shaped to provide a gripping engagement with said elongate foot portion at a point remote from the open end of said sleeve, said open end being of a diameter sufiiciently greater than the diameter of said foot portion as to receive concrete mix and permit the formation of a concrete plug to prevent entry of water into the space between the surface of said elongate foot portion and the interior surface of said sleeve, at least two of the projections of each rust protector being remotely spaced from each other to provide a stable three point support for said chair comprising the two remotely spaced projections of the rust protector of one foot portion and one projection of the laterally spaced rust protector of the other foot portion.

2. A rust protector as claimed in claim 1 in which said interior surface is tapered.

3. A rust protector as claimed in claim 1 in which said interior surface is provided with an annular constricted portion located close to said closed end but spaced therefrom.

4. A rust protector as claimed in claim 1 in which said projections are in the form of annular flanges surrounding said body portion.

References Cited UNITED STATES PATENTS 3,132,448 5/1964 Phillips et al 52689 2,305,979 12/1942 Mitchell 52396 X 3,289,378 12/1966 Carroll 5268'8 3,348,347 10/1967 Berry 52309 FOREIGN PATENTS 338,587 7/1959 Switzerland.

963,741 7/1964 Great Britain.

OTHER REFERENCES 293,077, July 1965, Netherlands, printed application Carroll.

ALFRED C. PERHAM, Primary Examiner U.S. Cl. X.R. 52-689