Patent Application
20130058736
The present invention relates to eye bolts and, more particularly, to eye bolts which are simple to start without need for a pilot hole and drivable without need for special tools or attachments.
Eye bolts with lag threads are commonly used to hang loads from overhead locations, such as beams and ceilings, as well as from walls, trees and other structures. In the usual procedure, the worker will either hammer the eye bolt into the structure (e.g., wood) in order to grab a few threads, or he will pre-drill a pilot hole. In either case the threaded shank of the eye bolt is thereafter manually screwed into the structure material using conventional tools such as wrenches or pliers to grasp the loop of the eye bolt or by insertion of a short bar through the eye of the bolt. The bar is then operated to rotate the eye bolt until the bolt is securely in place. Any type of short bar which fits through the loop of the bolt is satisfactory and, frequently, the shaft of a screwdriver is used as the bar. However, use of a bar for rotating the eye bolt is slow and clumsy, particularly if a large number of eye bolts are to be inserted in place. Special tools have been devised to assist in rotating the eye bolt, such as rotatable driver attachments which are configured to grasp and rotate the loop of the eye bolt. For example, U.S. Pat. No. 5,628,235 to Kambara discloses a portable drill attachment comprising separately adjustable jaws. U.S. Pat. No. 6,374,707 to Browning discloses a wrench comprising a shaft adapted to be driven by an electrically powered rotational driving device and an eye bolt cup having a cavity for snugly receiving the eye portion of an eye bolt. However, such special tools are expensive to acquire and, typically, not readily available.
It will be appreciated that the procedure for threading an eye bolt into a structure is cumbersome, time consuming and requires several different tools. Moreover, unless a pilot hole is first drilled, the starting process can be frustrating and difficult since hammering is likely to deform the loop end of the eye bolt. Of course, drilling the pilot hole requires additional time and additional tools. Accordingly, there exists a need for an eye bolt which can be easily started without need for a separately drilled pilot hole and which can be rapidly and simply inserted into a structure utilizing a single readily available tool.
It is, therefore, a primary object of the present invention to provide a novel and improved eye bolt which is simple to insert into a structure without need for special tools.
It is also an object of the present invention to provide a novel and improved eye bolt which is simple to start without need for a pilot hole and which can be rapidly inserted utilizing a single readily available tool.
It is another object of the present invention to provide a novel and improved eye bolt which includes a driving head to facilitate being driven by a tool capable of engaging the driving head and rotating the eye bolt about the axis of the shank.
It is yet another object of the present invention to provide a novel and improved eye bolt which is self drilling and self tapping.
The foregoing and other objects are achieved in accordance with the present invention by providing an eye bolt for insertion into a material comprising:
an elongate shank having a longitudinal axis and a loop projection extending from one end of said shank;
said shank having a threaded portion extending from the opposite end of said shank along at least a portion of its length; and
a driving head rigidly mounted on said loop projection, said driving head being coaxial with the longitudinal axis of said shank, whereby a rotational driving force applied to said driving head causes said threaded portion on said shank to screw into said material to securely insert said eye bolt into said material.
In another aspect of the invention, there is provided an eye bolt wherein the loop projection is either a fully closed loop, such as a circular loop, or a partially closed loop.
In yet another aspect of the invention there is provided an eye bolt wherein said driving head is polygonal for defining a plurality of flats, and/or said driving head includes a surface defining sockets or slots, which can be engaged by a rotatable driving tool.
In still another aspect of the invention there is provided an eye bolt for insertion into a material comprising:
an elongate shank having a longitudinal axis, a loop projection extending from one end of said shank and a self drilling and self tapping portion at the opposite end portion of said shank;
said shank having a first threaded portion along at least a portion of its length which is contiguous with said self drilling and self tapping portion; and
a driving head rigidly mounted on said loop projection, said driving head being coaxial with the longitudinal axis of said shank, whereby a rotational driving force applied to said driving head causes said self drilling and self tapping portion to drill an internally threaded hole in said material into which said threaded portion on said shank may be screwed to securely insert said eye bolt into said material.
In yet another aspect of the invention there is provided an eye bolt wherein said self drilling and self tapping end portion of said shank includes a second threaded portion along its length and a drilling tip at its free end, said drilling tip including cutting edges for drilling a core hole in the material.
In a preferred aspect of the invention said first threaded portion has a larger diameter than said second threaded portion and said self drilling and self tapping end portion includes a tapered threaded shank portion interconnecting the first and second threaded portions.
Referring to
Referring to
Referring to
In use, the eye bolt 10 is positioned for insertion into structural material with its boring tip 38 pressed against the insertion location. A rotatable tool is selected which is able to rotatably drive head 18. For example, such a tool might be a hand operated wrench, a socket wrench, a screwdriver or a power driven rotary tool having a driving element compatible with the grooves and/or sockets and/or flats of drive head 18. The positioning of drive head 18 coaxially with shank 12 allows rotation of the rotatable tool to rotate shank 12. Initially, the cutting edges 36 of drilling tip 34 drill a core hole in the material and, as tool rotation continues, the screw threads 30 of shank 12a are screwed into this core hole, creating an internally threaded hole for receiving larger diameter threaded portion 20 of shank 12. Tapered threaded shank portion 40 facilitates the transition between, and interconnects, screw threads 30 and the larger diameter threads of threaded portion 20 which, guided by the internally threaded hole, bite into the material until eye bolt 10 is fully screwed into the material.
While the present invention has been described in terms of specific embodiments thereof, it will be understood that no limitations are intended to the details of construction or design other than as defined in the appended claims.
