Systems and Methods for Indicating the Location of Various Structural Members in Concrete Members

This invention relates to systems and methods for indicating the location of structural members, such as pre-tensioned and post tensioned cable, strands and rods, which are disposed within the interstices of concrete members.

Many concrete members, such as concrete slabs or beams, employ high-strength structural members as the means of pre-tensioning or post-tensioning these members for providing strength requirements. In the building construction industry a serious safety concern is posed if these post-tension members are damaged or severed when holes used for anchorage devices or utility lines are drilled into the slab after the concrete has hardened. More specifically, since these tension members are the primary source of strength, these concrete members may fail if the tension members are severed.

The present methods of locating structural members are limited to the use of x-ray photography and/or magnetic induction devices. However, the x-ray photography and magnetic induction devices cannot distinguish between the mild standard concrete steel of concrete reinforcing elements and that of the structural members, respectively. Therefore, severing of the structural members often results. Moreover, the more reliable x-ray photography requires evacuation of the area being exposed during location of structural members for safety reasons.

With respect to other non-analogous uses such as underground utility lines in U.S. Pat. No. 3,523,515 and U.S. Pat. No. 3,927,637, devices have been provided which indicate the depth below ground depth and/or water level of those utility lines. In these devices, the depth can be read by an observer at the ground and/or water level surface.

Therefore, a need exists for a system for easily and accurately indicating the location of structural members located in the interstices of concrete members, in order to avoid the unwanted severing of these structural members when for example, holes are drilled into the concrete member.

The above-described existing needs have been met by the indicator system of the present invention which is used in locating structural members within a concrete member. Thus, the locating of such structural members is accomplished by employing at least one indicator means capable of showing the position of the structural member in the concrete member. Furthermore, the indicator means also can show the directional location of the support members. The indicator means of the present invention generally connects to a post member. This post member provides vertical support for the indicator system. A clamping assembly is attached to the post member and connects the structural member to the indicator system for fixing the location of the structural member.

The clamping system can also identify the location of the structural member, and the indicator means can then be provided to show the directional line of the structural member. Typically, the post member is sized to a predetermined length so that the longitudinal dimension of the indicator system corresponds to the thickness of the concrete member. In this way, after the concrete is cast, the indicator means will be visible at the surfaces of the concrete member. Depending on the location of the structural member, the clamping assembly is preferably slidably attached to, and movable to a plurality of positions along, the post member. The clamping member can also include coupling means for interlocking engaging with the structural member. A slidable clamping assembly can also be provided which comprises a sleeve section in sliding engagement with the post member. Moreover, the coupling means can further include a slot for facilitating the engagement and disengagement of the structural member therewithin.

In a preferred indicator system, a pair of indicator means are joined to the respective ends of the post member. Each indicator means is preferably positioned so that it will be substantially vertically aligned with the structural member, or in a plane substantially parallel to the longitudinal axis of the coupling means, for fixing the directional line of the structural member. Generally, the indicator means comprises a substantially flat outer surface, and directional indicator means elements pointed in the directional line of the structural member. The indicator means further can also include a holder section for joining the indicator means to the post member, and a fastener slot for joining the indicator system to an underlying concrete form.

The foregoing and other objects, features and advantages of the invention will become more readily apparent from the following detailed description of a preferred embodiment which proceeds with reference to the drawings.

FIG. 1 is an elevated, plan view of a typical concrete member including the structural member indicator systems of the present invention showing the location of the structural members in the interstices of the concrete member.

FIG. 2 is an elevated, enlarged sectional view taken along line 2--2 of FIG. 1.

FIG. 3 is an enlarged, front view of the structural member indicator system of the present invention.

FIG. 4 is an enlarged, side view of the structural member indicator system of FIG. 3.

FIG. 5 is an enlarged plan view of the structural member indicator system of FIG. 3.

Referring now to FIGS. 1 and 2, the structural member indicator system of this invention, denoted 10, is disposed within the interstices of a concrete member 30, in this case a concrete slab. Indicator system 10 is more specifically depicted in FIGS. 3-5, and comprises a post member 12 which supportedly connects at its respective ends 14 to top and bottom indicator means 16 and 18, respectively. Indicator means 16 includes a base portion 22 having a substantially flat outer portion 24 and including a holder portion 26 to which post member 12 is joined. A retaining collar 13 is joined about holder 26 for maintaining indicator system 10 in position within concrete member 30. The indicator means 16, which is generally elongated in shape, comprises a substantially rectangular support portion 15 and a pair of pointed directional indicators 17 extending from the elongate edges 19 at one end of indicator means 16. Typically, one of the flat surfaces 24 will rest on a complementary substantially flat underlying surface, typically a concrete form 32. Flat surface 24 is generally in a horizontal plane during use. Therefore, post member 12 will preferably extend at right angles to the flat surfaces and in a substantially vertical plane. Slot 28 is provided in base sections 16 and 18 having a central aperture 29 which passes entirely through base portion 22 and surface 24 (see FIG. 5). Fastening means 25, in the form of a nail in FIG. 4, pass within aperture 29 and attach the indicator system 10 to a concrete form 32 (see FIG. 2).

A clamping assembly 40 is connected for sliding engagement via sleeve portion 42 to post member 12 between indicator means 16 and 18. Coupling means 46, preferably in the form of a snap clamp, is joined to sleeve portion 42 by arm portion 44. A slot 48 is disposed within the coupling means 46 for facilitating the engagement and disengagement of cable 50 from within the coupling means. The coupling means extend in a longitudinal plane in substantially the same direction as the pointed directional indicators 17 which are shaped to indicate the direction that the line of the cable extends. Therefore, the pointed directional indicators 17 will provide a directional marker for locating the cable 50 and for indicating the direction in which the cable extends within the coupling means 46.

Preferably, the indicator system 10 is fabricated from a polymeric or metal material, depending on cost and use requirements of a given installation.

In operation, structural members 50 are first installed in position over the construction forms 32. Each clamp assembly 40 is then placed onto each of the cables 50 by moving slot 48 the cable, and then into coupling means 46. Next, post member 12 is inserted through sleeve 42. Previously, post member 12 was precut to a size equal to the predetermined thickness of the concrete member 30. The bottom indicator means 18 is attached to the bottom of post member 12 by inserting lower end 14 into holder portion 26 of the top indicator. The post member is then aligned vertically and bottom indicator 18 is joined to the form 32 by driving nail 25 thereinto. The top indicator means 16 is attached to the top of post member 12 by inserting the upper end 14 into holder portion 26 of the bottom indicator. The concrete member 30 is then cast. When the concrete member 30 has set, the forms are removed and the indicator system 10 remains in place and in alignment with the outer surface of the concrete member so that indicator means 16 and 18 depict the location and directional location of the cables 50.

Having illustrated and described the principles of my invention in a preferred embodiment thereof, it should be readily apparent to those skilled in the art that the invention can be modified in arrangement and detail without departing from such principles. We claim all modifications coming within the spirit and scope of the accompanying claims.