1. TECHNICAL FIELD
The present invention generally relates to tools and, more particularly, to an alignment guide for a core bit used with a rotary drilling apparatus. Specifically, the invention relates to a collapsible alignment guide that may be used with any of a plurality of different core bits to form smooth holes in block walls wherein the holes are desired to be perpendicular to the outer surface of the wall.
2. BACKGROUND INFORMATION
Numerous situations require a hole to be drilled through a block wall. One product that benefits from such a hole is the THERMOTHIMBLE® poke through disclosed in US 20050109523. A concrete core bit typically is used to form these holes in block walls. A concrete core bit is an elongated cylindrical drill bit with a circle of teeth disposed on the cutting end of the cylinder. A drawback with using these bits for cut holes in concrete block walls is that there is no centering mechanism or starter on the bit itself. The combination of the wall material and the difficulty of maintaining the core bits centered makes forming smooth holes in block walls difficult to form.
The invention provides an alignment guide for a core bit. The guide laterally supports a core bit perpendicular to the wall in which the hole is being drilled. The support thus allows the core bit to start a smooth hole perpendicular to the wall and successfully drill a high quality hole with smooth edges.
In one configuration, the invention provides a collapsible alignment guide for a core bit. The guide is provided to the user in a collapsed configuration. The user erects the guide and uses a connector to hold the guide in an erect configuration wherein the guide may be used to stabilize a core bit. In one configuration, the guide may be formed from a flat blank of material that is folded into a collapsible six sided box with opposed sets of guide openings.
In another configuration, the alignment guide is arranged to work with a plurality of different core bit diameters. Different hole sizes are provided on the three sets of opposed walls of a six-sided box. Perforated lines may be provided outwardly of the openings to allow the user to increase the size of the openings to configure the guide for a different size bit.
The invention also provides a configuration wherein the small core bit holes are formed through double thickness walls formed by overlap tabs.
Similar numbers refer to similar parts throughout the specification.
The guide of the invention is indicated generally by the numeral 2 in the accompanying drawings. Guide 2 is used to stabilize and laterally support a core bit 4 during the process of drilling a hole in a structure such as a concrete block wall 6 or foundation 6. Such stabilization and lateral support of a core bit 4 has been found to yield smooth, well-defined holes in traditionally unpredictable surfaces such as concrete block structures.
Guide 2 is in the form of a six-sided box having guide openings disposed on opposed walls of the box. The pairs of opposed walls are disposed perpendicular to one another when the box is erected and ready for use. Guide 2 provides at least one pair of aligned guide openings configured to be slightly larger than the outer diameter of core bit 4. The openings a small enough to create some friction with a rotating core bit but large enough to allow the bit to be easily slid through the openings. Guide 2 may provide three sets of aligned guide openings on its three sets of opposed walls for three different diameter bits. The three sets of openings may be provided in small, medium, and large diameters. Guide 2 may also provide additional alternative guide opening sizes to increase its versatility with different bit diameters.
Guide 2 may be formed from a unitary blank 12 or 14 as shown in
In the alternative configuration shown in
In the blank of
Notches 60 may be used to reduce the resiliency or spring-back force of the hinge between walls 20/22 and 26. Notches 60 may be enlarged scored areas or sections of walls 20 and 22 that have been completely removed. Both methods reduce the width and thus the strength of the living hinge and allow walls 20 and 22 to be easily folded into the erected position.
Tape 62 may be used to hold walls 20 and 22 in the erected position as shown in
Three or four mounting pads 70 may be used when guide is in use. Pads 70 may have adhesive holding forces that help hold guide 2 in place. Pads 70 may be adhesively connected to guide 2 and wall 6. In an alternative, pads 70 may be provided in pairs of hook and loop connectors that are held to guide 2 and wall 6 with adhesive and then locked together with the hook and loop connectors. An example of this type of product is available as Command Removable Interlocking Fasteners sold by 3M. A mounting putty may also be used to help hold guide 2 in place during use. Pads 70 may be used to dampen vibration forces.
At least one handle 80 also may be used to allow the user to hold guide 2 in place during use. Handles 80 may be secured to guide 2 with connectors such as adhesives, tapes, interlocking engagements, and mechanical connectors.
Guide 2 is formed in the configuration shown in
In the foregoing description, certain terms have been used for brevity, clearness, and understanding. No unnecessary limitations are to be implied therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes and are intended to be broadly construed.
Moreover, the description and illustration of the invention is an example and the invention is not limited to the exact details shown or described.