Patent Application
20120160990
This invention relates to an apparatus for holding concrete forms together or in place, while concrete is being placed, or for any number or reasons a rod must be held.
Concrete forms are typically held together by standard form ties while placing concrete. Forms are manufactured to have a standard spacing for which the ties are made. If this spacing deviates from the standard spacing, then metal pencil rods and rod clamps are typically used to hold the non-standard forms together. The rod clamps that are used are conventional and have been in use for many years.
Conventional rod clamps are typically in the form of a metal casting having a hole through which a form tie or pencil rod (hereinafter referred to as rods) can be passed. A bolt is threaded into the casting in a direction perpendicular to the rod, so that the bold can be tightened to clamp against the rod and secure it in place within the casting. The casting has a flat side adapted to rest against a concrete form, and is sufficiently large to prevent the casting from slipping through the form when pressure is applied by the poured concrete. Rod clamps are normally placed on both sides of concrete forms, and must be held tight against the form while concurrently tightening the bolt to hold the rod in place. The bold must be sufficiently tightened to secure the rod, yet not so tight as to sever the rod.
Rod clamps of the type described above are widely used and work well if the bolts are not fouled, such as with concrete or corrosion. However, fouling is inevitable under the conditions in which the clamps are used. Furthermore, the bolt threads can eventually become stripped due to over-tightening or repetitive use. However, damage to the rod and stripping of the bolt threads are often not discovered until the concrete pressure is applied, at which point the clamp is no longer able to secure the forms and the forms give under the pressure from the concrete. If a clamp fails, the forms must be braced in some manner to keep the concrete from bulging the forms.
An alternative to the rod clamp described above comprises a metal piece through which a rod is passed. The metal piece does not use a bolt to secure the rod, but instead uses a notched hinged piece that is adapted to bias against the rod. This type of rod clamp has not been as widely adopted because the notch is prone to wear.
The present invention provides a rod clamp assembly and method for securing a rod, for example, a form tie or pencil rod used to secure and support concrete forms.
According to a first aspect of the invention, the rod clamp assembly includes a housing and a wedge member. The housing has sidewalls and endwalls. The sidewalls are arranged to define at least first and second pairs of sidewalls, and the endwalls are arranged to define at least one pair of endwalls. The sidewalls of the first pair of sidewalls are oppositely-disposed from each other, the sidewalls of the second pair of sidewalls are oppositely-disposed from each other, and the endwalls of the pair of endwalls are oppositely-disposed from each other. Each of the first and second pairs of sidewalls has a side passage that passes entirely through the housing. The side passages have congruous cross-sectional shapes and are defined by side passage walls within the housing. The side passages of the first and second pairs of sidewalls intersect each other to define an interior cavity within the housing. The pair of endwalls has an end passage that passes entirely through the housing and through the cavity within the housing to define an intersection with the cavity. The end passage is defined by end passage walls within the housing. The wedge member has a first longitudinal end, an oppositely-disposed second longitudinal end, and at least a first ramp feature at the second longitudinal end that defines an edge that is not parallel to a longitudinal axis of the wedge member. The wedge member has a cross-sectional shape congruous to the cross-sectional shapes of the side passages of the housing, and a longitudinal length that is sufficient so that the first ramp feature enters the intersection between the end passage and one of the side passages when the wedge member is inserted through the one of the side passages of the housing.
Other aspects of the invention include methods of using the rod clamp assembly to secure and support concrete forms.
A technical effect of the invention is the versatility of rod clamp assembly and its ability to repetitively reused. Notably, the rod clamp assembly is more resistant to fouling than prior art rod clamps, since concrete, sand, dirt, rust and other potential foulants are able to flow completely through the rod clamp housing and are therefore less likely to be trapped within the housing. Foulants that become trapped within the housing are less likely to affect the operation of the assembly, and can be easily removed. In addition, the wedge member can be inserted through any one of four sides of the housing, allowing the wedge member to be installed from a more convenient location and orientation based on the placement of the housing. Installation of the wedge member does not require threads, notch, or any other special fastener, but instead can be installed by being forced into engagement with a rod passing through the housing, for example, by driving the wedge member with a hammer. As such, the rod clamp assembly does not comprise threads or other relatively delicate or precision features that are prone to damage from corrosion and fouling. The length of the wedge member can be sized so that full installation of the member involves completely driving the member into the housing until an abutment feature on the wedge member abuts the housing.
Other aspects and advantages of this invention will be better appreciated from the following detailed description.
As represented in
Each pair of sidewalls 16 has a side passage 20 that passes entirely through the housing 14. Preferably, the side passages 20 have identical (or at least congruous) cross-sectional shapes. In the embodiment shown, the side passages 20 have rectangular cross-sectional shapes that correspond to a preferred (but not required) rectangular cross-sectional shape of the wedge member 40, as evident from
A passage 32 also passes entirely through the housing 14 between the pair of endwalls 18. The passage 32, which may be referred to as an end passage 32, also passes through the cavity 24 within the housing 14 defined by the side passages 20, such that the side and end passages 20 and 32 define an intersection 34 with the cavity 24. The end passage 32 is defined by end passage walls 36 within the housing 14. As evident from
The wedge member 40 can be specially fabricated for use with the housing 14. Alternatively, commercially available hardware can be used as the wedge member 40, for example, bolts that are commercially available from Dayton Superior under the SYMONS® and STEEL-PLY® line of products. The wedge member 40 represented in
As evident from
As previously noted, insertion of the wedge member 40 into one of the side passages 20 and into engagement with the rod 12 can be performed with a hammer or other tool. The length of the wedge member 40 between the tapered end 44 and abutment feature 52 can be such that the tapered end 44 protrudes from the housing 14 at the sidewall 16 opposite the sidewall 16 through which the wedge member 40 was installed, which enables the wedge member 40 to be removed from the side passage 20 by striking the tapered end 44 of the wedge member 40. The housing 14 is represented as having holes 54 through which nails, screws, or other suitable fasteners can be driven to temporarily secure the housing 14 to a concrete form during installation and removal of the housing 14.
While the invention has been described in terms of a specific embodiment, it is apparent that other forms could be adopted by one skilled in the art. For example, the physical configurations of the rod clamp housing and wedge member could differ from that shown, and materials and processes other than those noted could be used. Therefore, the scope of the invention is to be limited only by the following claims.
This application claims the benefit of U.S. Provisional Application No. 61/359,868, filed Jun. 30, 2010, the contents of which are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61359868 | Jun 2010 | US |
