OPEN ACCESS STUD GRIPPING TOOL

Abstract: Stepped roller pins roll within stepped lobes formed around the interior wall of a hollow cylindrical casing. A hollow cylindrical retainer or simple ring retainer hook into a recessed groove around the middle of the roller and interact with ridges or grooves in the casing to retain the rollers within the lobes. The retainer fits within the limits of movement of a larger diameter section of the roller so that maximum contact is made between the rollers and a smooth stud shaft which is encircled by the casing to any desired extent. The rollers move along the lobes until they lock tight to grip the stud shaft for threading or unthreading. The casing is provided with wrench gripping faces around the exterior. A wrench grips the casing from the side to operate it leaving both ends of the casing open to admit the stud shaft.

Description: Background of the Invention 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. 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. PATENT # 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 In accordance with the present invention there is provided a stud gripper tool comprising a hollow open-ended cylindrical casing having a working end and a handle receiving end and at least one pair of axially aligned lobes on the inner surface of the casing, a roller associated with each pair of lobes, roller retaining means for retaining said roller inside the casing and in rolling contact with said lobes and a handle receiving means on the exterior of the casing at the handle receiving end, characterized in that; at least one pair of said lobes is stepped axially and aligned in longitudinal relationship comprising a larger radius of curvature at the working end where larger radius lobe intrudes into the interior surface of the casing further than the smaller radius lobe at the handle end and are separated by a ridge formed in the interior surface of the casing between the lobe pair, said roller is also stepped in that at least one elongated, axially extending roller, has a larger diameter cylindrical shaft portion in rolling contact with said larger radius lobe and is disposed toward the working end of the casing to tighten about a stud shaft when the casing is turned about the stud, and a smaller diameter cylindrical shaft portion in rolling contact with said smaller radius lobe and is disposed toward the handle receiving end of the casing for engaging with the roller retaining means to keep said roller from falling out of the casing, where said roller's larger diameter end and said roller's smaller diameter end are separated by a circumferential recess, said roller retaining means comprising a hollow cylinder portion inside and coaxial with the casing and having a larger lip externally protruding at one end of the cylinder portion for engaging a rim of the casing to prevent said cylinder portion from moving towards the working end of the casing; and having a small lip externally protruding at the other end of the cylinder portion for engaging with said circumferential recess to retain said roller in the casing and to maintain said roller in rolling contact with the pair of stepped lobes, wherein the inner diameter of the hollow cylinder portion of the roller retaining means is such that a clear interior opening through the entire casing from the working end to the handle end is maintained, to admit a stud therethrough, which stud may be approximately equal in diameter to a circumferential boundary defined by the larger diameter shaft portion of the roller. 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. Using 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 advantages of our invention will be described in connection with the accompanying drawings, which are furnished only by way of illustration and not in limitation of the invention, and in which drawings: Figure 1 is a perspective view of the preferred embodiment of the stub gripping tool; Figure 2 is a cross-sectional view of the preferred embodiment taken through 2-2 of Figure 1, showing the stepped rollers and a double-lipped cylindrical retaining means; Figure 3 is a cross-sectional view of a stud gripping tool which is not within the scope of the invention and which has a ring retaining means and a roller of equal diameter on both ends; Figure 4 is a broken perspective view in partial section of the components of the preferred embodiment of the gripping tool aligned for assembly; and Figure 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 Figures 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 Figure 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 Figure 5. The working ends of the rollers align with the working end face 19, as seen in Figure 1. Each roller is then free to roll within each pair of lobes so that when a stud shaft 60, in Figure 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 Figure 3 there are shown 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, which is defined in claim 1.

Claims: A stud gripper tool (10) comprising a hollow open-ended cylindrical casing having a working end (16) and a handle receiving end (14) and at least one pair of axially aligned lobes (20, 42) on the inner surface of the casing, a roller (18) associated with each pair of lobes (20, 42), roller retaining means for retaining said roller (18) inside the casing and in rolling contact with said lobes (20, 42) and a handle receiving means (12) on the exterior of the casing at the handle receiving end (14), characterized in that; at least one pair of said lobes is stepped axially and aligned in longitudinal relationship comprising a larger radius of curvature at the working end where larger radius lobe (20) intrudes into the interior surface of the casing further than the smaller radius lobe (42) at the handle end and are separated by a ridge (36) formed in the interior surface of the casing between the lobe pair, said roller (18) is also stepped in that at least one elongated, axially extending roller, has a larger diameter cylindrical shaft portion (40) in rolling contact with said larger radius lobe (20) and is disposed toward the working end of the casing (16) to tighten about a stud shaft (60) when the casing is turned about the stud, and a smaller diameter cylindrical shaft portion (34) in rolling contact with said smaller radius lobe (42) and is disposed toward the handle receiving end of the casing (14) for engaging with the roller retaining means to keep said roller (18) from falling out of the casing, where said roller's larger diameter end (40) and said roller's smaller diameter end (34) are separated by a circumferential recess (38), said roller retaining means comprising a hollow cylinder portion (26) inside and coaxial with the casing and having a larger lip (28) externally protruding at one end of the cylinder portion (26) for engaging a rim of the casing (32) to prevent said cylinder portion (26) from moving towards the working end of the casing; and having a small lip (30) externally protruding at the other end of the cylinder portion for engaging with said circumferential recess (38) to retain said roller (18) in the casing and to maintain said roller (18) in rolling contact with the pair of stepped lobes (20, 42), wherein the inner diameter of the hollow cylinder portion of the roller retaining means is such that a clear interior opening through the entire casing from the working end to the handle end is maintained, to admit a stud therethrough, which stud may be approximately equal in diameter to a circumferential boundary defined by the larger diameter shaft portion of the roller. A stud gripper tool according to claim 1 wherein the large lip (28) of the roller retaining means forms a continuous plane with a flat end surface of the handle end of the casing. A stud gripper tool according to claim 1 wherein the roller (18) aligns with an end face of the casing at the working end of the casing. A stud gripper tool according to claim 1 wherein the handle receiving means (12) comprises surface variations around an exterior surface of the casing at the handle end. A stud gripper toil according to claim 4 wherein the surface variations comprise a series of standard faces for receiving a wrench or like tool around the handle end of the casing. A stud gripper tool according to claim 1 wherein the handle receiving means (12) comprises a permanent connection to a handle rigidly secured to the casing. A stud gripper tool according to claim 1 comprising at least three adjacent pairs of lobes positioned around the interior surface of the casing and a stepped roller contacting each lobe pair. A stud gripper tool according to claim 1 comprising a single pair of lobes and a stepped roller contacting the lobe pair, wherein the remaining inside surface of the casing is provided with a plurality of spaced axially extending flutes, ribs or teeth for gripping in cooperation with the roller and lobes.

Inventors: MCLAUGHLIN, EDWARD T., YOUNG, RICHARD H.
Applicants: MCLAUGHLIN, EDWARD T., YOUNG, RICHARD H.
Application year: 1986
Main classification: B25B13
IPC codes: B25B23