Background of the Invention
1. Technical Field
The present invention relates to stud gripping tools for removing or installing the stud and in particular to a stud gripping tool employing rolling pins on lobe surfaces with open access through the tool head for admitting and gripping a smooth stud shaft at any point along its length.
2. Background Art
Most tools for gripping screw-in connectors are primarily designed for engagement with a head on a bolt or screw rather than the smooth cylindrical shaft of the stud. Shaft gripping tools tend to be complex and too large to fit into tight locations.
Most other stud gripping tools are complex have devices at the end of the tool for retaining the gripping means, thereby recessing the working components of the tool interiorly of the retaining means precluding any gripping action at the end of the tool.
Present stud gripping tools, including applicant Young's tool described in his U.S. Pat. No. 3,889,557, generally utilize a handle, such as a socket wrench handle, which attaches to the top of the gripping head, thereby blocking access at the top of the head to prevent the stud from passing completely through the head and thereby limiting contact of the gripping tool to a small portion of the stud shaft, or the retaining means blocks through passage of the stud.
Disclosure of Invention
Providing three simple components: a stepped roller, mating stepped lobular cam surfaces and a simple retaining means creates a compact and simple means for removing and installing studs by gripping the smooth shaft of the stud regardless of how tight the access space might be.
Using a simple retaining device, such as a ring or a thin-walled cylinder installed adjacent to a smaller diameter section of the roller within the boundary limits of the larger diameter section of the roller, permits full access of the larger diameter section of the roller to the shaft inserted into the stud gripping head. A shaft nearly equal in diameter to the working boundary limits of the large diameter sections of the rollers may be gripped utilizing the full power with maximum contact of the rollers on the shaft.
Having the retaining means recessed out of the way within the boundary limits of the working sections of the rollers and providing a series of external flat surfaces, such as hexagonal faces, around the invention at one end enables use of the invention with a standard wrench around the perimeter of the casing, and thereby leaves the central axis of the invention completely open so that the invention may fit over a stud and slide down the stud shaft to any point on the shaft for application of the gripping force.
Having the retaining means recessed at the handle end of the invention permits the working ends of the rollers to extend to the very end of the casing, so that the invention can grip even at the very end of the tool and thereby provide maximum gripping power on a stud even close to the surface to which the stud is attached.
Usng a ring retaining means fitting into a central groove in each roller with a protruding wall ring around the casing enables the rollers to be the same size on both ends of the casing and thereby creates twice the gripping contact and twice the power.
Brief Description of the Drawings
These and other details and advantages of our invention will be described in connection with the accompanying drawings, which are furnished only be way of illustration and not in limitation of the invention, and in which drawings:
FIG. 1 is a perspective view of the preferred embodiment of the stub gripping tool;
FIG. 2 is a cross-sectional view of the preferred embodiment taken through 2--2 of FIG. 1, showing the stepped rollers and a double-lipped cylindrical retaining means;
FIG. 3 is a cross-sectional view of an alternate embodiment of the invention having a ring retaining means and a roller of equal diameter on both ends;
FIG. 4 is a broken perspective view in partial section of the components of the preferred embodiment of the gripping tool aligned for assembly;
FIG. 5 is a perspective view of the gripping tool applied to a smooth cylindrical stud shaft and utilizing an open-end wrench for turning the gripping tool.
Best Mode for Carrying Out the Invention
In FIGS. 1, 2 and 3 the gripping tool 10 comprises a hollow cylindrical casing having a handle portion 14 with means to turn the casing, such as the hexagonal faces 12 around the casing exterior to receive a standard wrench 57, as seen in FIG. 5. Opposite the handle end is the working end 16 which may be smooth or have any desired configuration around the exterior.
Interiorly of the casing a series of paired stepped lobes 20 and 42 are formed into the interior surfaces of the casing, each pair extending longitudinally from the working end to the handle end of the casing. Each lobe pair receives a stepped roller 18. A larger diameter working end 40 rolls within the working lobe 20 and the smaller diameter retained end 34 rolls within a smaller lobe 42 at the handle end of the casing. A retaining means, such as the cylinder 26 holds the rollers in rolling contact with the lobes. A large lip 28 extending from one end of the cylinder 26 rests against a recessed rim 32 around the mouth of the handle end of the casing. A smaller lip 30 extending from the opposite end of the cylinder 26 hooks into a recessed groove 38 around the roller between the large and small diameter sections.
The larger diameter section 40 encounters a ridge 36 in the interior casing surface between the large working lobes 20 and smaller retaining lobes 42 to prevent the rollers from falling out of the handle end, while the retaining cylinder 26 prevents the rollers from falling out of the working end of the casing. The retaining cylinder which may be plastic fits with the larger lip 28 forming a continuous surface with the handle end face 55 of the casing, as seen in FIG. 5. The working ends of the rollers align with the working end face 19, as seen in FIG. 1.
Each roller is then free to roll within each pair of lobes so that when a stud shaft 60, in FIG. 5, is positioned within the casing in contact with the working ends of the rollers, a ramped camming action takes place within each lobe to lock the rollers around the stud shaft for a tight grip. The shaft may then be turned as desired to install or remove the stud. Naturally the gripper may be used on the heads of nuts or bolts and around any shaft-like connector which will fit within the rollers when gripping and turning is desired.
In FIG. 3 an alternate embodiment of the invention utilizes rollers 18A having equal diameters on both sections 34A and 40A of the roller with a recessed groove 38A between the two different sections. A rigid circular ring 50 fits within the grooves and interacts with an annular protrusion 46 forming a band around the interior surface of the casing to retain the rollers in place leaving them free to roll within the lobes 20 and 42A which are equal in this embodiment to interact with the equal roller sections. Both ends of the rollers align with both ends of the casing in this embodiment.
The rollers and casing are formed of high quality steel normally used in tools, although the retaining means may be fabricated of plastic.
It is understood that the preceding description is given merely by way of illustration and not in limitation of the invention and that various modifications may be made thereto without departing from the spirit of the invention as claimed.