Patent Application
20170106503
In a principal aspect the present invention relates to a socket construction of a type utilized by automotive repair mechanics and service personnel. More specifically, the invention comprises a socket construction wherein the socket has a driven end, typically with a square or spline drive cross section counterbore, and a drive end, with a hexagonal cross section counterbore for engaging a threaded fastener to either attach or remove the fastener from a compatibly threaded bore or opening. The socket may comprise an alternative to sockets Type I, II and VII as disclosed by ASME standard B107.110-2012 (incorporated herein by reference).
When repairing automobiles, machinery or other items, a mechanic or technician typically requires multiple sets and types of tools, including wrenches, for removal of or attachment of bolts, screws, nuts and other fasteners. For example, one such task involving a mechanic is attachment or removal of the harmonic balancer associated with an internal combustion engine. That is, the harmonic balancer may be attached by hexagonal headed bolts threaded into and recessed in a counterbore. The bolts thus fasten the harmonic balancer to the drive shaft of the internal combustion engine. To remove the harmonic balancer from the shaft, a hexagonal socket may be positioned on the head of a bolt and a pneumatic impact tool is then fitted on the socket and used to drive the socket and thereby unthread the fastener from the shaft to which the balancer is attached. The above-referenced sockets may typically be used for this task.
This is an extremely difficult undertaking and typically requires a pneumatic impact tool to drive the socket in order to provide adequate torque necessary to loosen and remove the fasteners. Because the head of a fastener is often recessed in a counterbore, access may be limited or restricted. Also, because a fastener may be corroded, very high torque may be required to effect removal of the fastener. Many motor vehicles exhibit this problem including, for example, certain models of Honda brand vehicles.
Thus, there has developed a need for tools and methods for removal of extremely tightly or highly torqued fasteners, particularly from vehicles wherein fasteners are used to attach a harmonic balancer or some other mechanical part to the vehicle or vehicle engine.
Briefly, the present invention comprises an elongate, high mass, impact socket comprised of a body with a generally cylindrical section that extends between a driven end of the socket and a drive end of the socket. The driven end of the socket may comprise a square or spline cross section counterbore or structure adapted to receive the drive, such as a square drive or spline drive, of a pneumatic impact tool. The opposite drive end of the socket includes a hexagonal counterbore or opening coaxial with the generally cylindrical section or body and the driven counterbore end. The dimensions, density, mass, physical character and outer surface shape of the socket construction typically comprises features of design including an elongate, high mass, socket useful in a circumstance where many prior art sockets do not function appropriately or may fracture or otherwise fail. Additionally, the disclosed sockets are fabricated with a unitary design compatible with a high impact, pneumatic driver.
Thus, an aspect, feature, objective and benefit of the socket construction of the invention is to provide a carefully dimensioned, elongate socket construction having a relatively high density, increased mass relative to a typical socket, high tensile strength and good fracture toughness. The socket has dimensional and other requisite characteristics including weight or mass which enable the socket to provide high impact forces on a fastener to efficiently and effectively loosen a very heavily torqued and tightly attached fastener from a threaded passage or bore. The socket is uniquely useful in combination with a cooperative, pneumatic impact tool to drive the socket.
A further object of the invention is to provide a socket which has broad utility; namely, a design that will enable efficient operation in combination with a standard impact tool or wrench for removal of frozen or locked fasteners.
Another object of the invention is to provide a socket which is useful over a wide range of torque requirements for attachment as well as removal or unthreading of a fastener.
These and other aspects, objects, advantages and features of the invention are set forth in the detailed description which follows.
In the detailed description which follows reference is made to the drawing comprised of the following figures:
Sockets having an appropriate size, mass or weight and design in combination with a standard pneumatic impact wrench are disclosed. Such sockets provide a successful means to increase the effective torque imparted to a fastener and thereby enhance the efficiency and the utility of an impact tool or wrench to detach or unthread or thread a fastener from or into a threaded bore or passage. That is, typically the necessary torque or turning force required to remove a fastener from a threaded passage or bore is dependent upon the condition, size, design and configuration of the fastener and the threaded bore. The dimensional characteristics or relationship between the size of and the dimensional and design characteristics of a socket to provide adequate, useful torque and thus effect fastener removal are uniquely disclosed.
A socket embodiment of the invention is depicted in
A second uniform diameter, concentric, cylindrical outside section 22 of the body 10 extends axially intermediate the first section 14 and the second face 18 at end surface 21. The second section 22 has an outside diameter in the range of about 80%±5% of the outside diameter of the first section 14 which has a cylindrical cross section as depicted in
The outside radius of the first section 14 is in the range of 2.25±0.2 times the point to point dimension 30 of a hexagonal counterbore 24 at the drive end axis coaxial with a square or spline counterbore 26 in the driven end of the body 10. The socket has an axial dimension 13 in the range of about 5+0.2 to −0.1 times the axial depth dimension of the hexagonal counterbore 24. Section 14 has an axial dimension of about 2.5 inches in the embodiment depicted. The socket further has a material density in the range of about 0.28±0.3 pounds per cubic inch and tensile strength in the range of or at least greater than about 150,000±25,000 psi. The socket further includes a transverse or radial passage 32 at the driven end 19 of the socket which is for receipt of a pin of a drive of an impact tool joined to the socket.
The first greater axially extending section 14 and the second, lesser axially extending section 22 of the socket are joined along a circumferential, arcuately curved uniform radius section 34. The square counterbore 26 has a point to point dimension in the range of 1.0±0.50 times the point to point dimension of the hexagonal counterbore 24.
Tables 1 and 2 set forth a summary of the physical parameters of a standard socket and two test sockets. Socket 1 is a prior art standard socket design. Sockets 2 and 3 are variations of the socket design embodiments of the invention wherein socket design 3 is a preferred embodiment depicted in
Thus, the dimension of the socket drive end is correlated with the other socket dimensions. In particular, the diameter of the threaded fastener and the head thereof serve as an initial basis for determination of and maintaining proportionality with the remaining dimensions and mass of the socket. As a consequence, upon determining the size and dimensions of a fastener diameter and fastener head, one may calculate a proportional relationship to the remaining dimensions of a socket associated with a particular fastener having a particular thread design. Importantly, the mass of the socket is correlated with fastener dimensions. Each socket can in this manner be correlated with the size of the fastener which is to be removed or engaged and driven.
Following are examples of sockets (items 2 and 3) which are designed to safely maximize dimensional limits to provide adequate torque in the environment associated with the tools and devices which require high torque to be provided by standard torque wrenches.
The empirical data of two series of tests, as set forth in Tables 3 and 4, was obtained using test sockets 1, 2 and 3 of Table 1 and Table 2 to remove threaded fasteners in compatible threaded openings in a test block. The test block was thus threaded to receive a standard “Harmonic Balancer Bolt”. A thread locker compound “Loctite 232” was applied to the bolt prior to being threaded into a test block. The “Loctite” (trade name) compound was allowed to cure after the bolt was tightened to various torque values as shown in Tables 3 and 4. The “Loctite” compound was applied to simulate the effects of corrosion and “tightness” of the fastener.
The tests to effect removal of the fasteners were conducted with a Craftsman Model No. 875-198650 air impact wrench. The wrench was operated at a static pressure of 88 psi and a dynamic pressure of 50 psi. The air impact wrench is typical of the type used by technicians for the removal of Harmonic Balancer Bolts and was used to untighten the test bolts after they had been secured into the test block.
The sockets tested and were of various weights, dimensions and configurations. Socket No. 1 weighted 8 ounces and is typical of a standard 19 MM impact socket. Socket No. 2 was manufactured for test purposes and weighed 20 ounces. Socket No. 3 is a high mass socket with a weight of 30 ounces and dimensions set forth in Table 2.
The test result (Tables 3 and 4) were compiled and demonstrate the effectiveness of the increased mass and test design of test sockets to loosen fasteners that had been tightened in increments up to 400 ft.-lbs. This information is exhibited in graphical form in
Another approach to identify the improved torque that is applied to a fastener which has been locked in place constitutes calculation of a parameter wherein the relative mass of the prior art type socket is compared with examples of the sockets of the invention. Reference is therefore made to Table 5 which identifies various sized sockets. The column identified as Socket Style references standard prior art sockets. The legend “extended” references sockets designed and made in accord with the invention wherein the density of the socket material is the same for the standard as well as the extended sockets. In every event the comparison is made between socket sizes of the same size. The standard socket sizes are in conformance standards ASMEB107, 110 ZR sockets. The sockets identified as extended are designed to engage fasteners of the same size but the ratio of the mass for the 19 MM sockets is approximately 2.25 to 1. For the 21 MM sockets, it is approximately 2.5 to 1 and for the 27 MM sockets, it is approximately 2 to 1. This variance provides significant advantages as indicated by the tensile forces that can be applied successfully to test specimens.
That is, test specimens were prepared substantially identically with utilization of a tension calibrator. The calibrator is a device typically used for calibrating impact wrenches and testing fasteners. The calibrator consists of a hydraulic load cell with an opening in the center for insertion of a sample bolt as a test specimen. As the bolt is tightened, the load cell is compressed creating internal pressure. A gauge measures the pressure and provides a dial readout allowing the tensile force created in the bolt to be measured. The test bolts for the variously sized specimens are listed in Table 5. All the bolts were identical material and had the same thread size. The bolts were provided with a hexagonal head that was the size corresponding to the socket that was being tested. The bolts were tightened in 1,000 pound tension increments.
After tightening, attempts were made to loosen the bolts using an impact wrench as described above. The impact wrench was assembled with the appropriate socket size. When the bolt could no longer be loosened, the selected socket with the selected socket, that tension limit was noted in the chart. The static pressure used for the impact wrench was 85 psi and the dynamic pressure was 55 psi in all events. As will be seen in Table 5, the tensile force applied to the test specimens wherein the specimen was subject to being removed by “extended” sockets was significantly greater than use of standard sockets. The ratio of the standard versus the “extended” sockets test results is approximated in the far right hand column. It is noted that the sockets incorporating design aspects of the present invention remove fasteners by imparting a tensile force typically greater than twice that of the standard sockets.
Thus, the construction of the sockets disclosed enable maximization of torque in a restricted space environment using standard torque wrenches. By correlating a set of sockets to the dimensional patterns and proportions of the example fasteners disclosed utilizing the diameter of the fastener associated with the socket, a uniquely configured, sized and “extended” mass socket can be constructed for efficient removal or driving of the particular sized fastener.
The above test results demonstrate the effectiveness of the additional mass and alternate design via extended sockets to loosen the tightened test specimens. This would equate to the enhanced effectiveness for loosening various bolts, fasteners, etc. that may be corroded or damaged.
Variable features of the “extended” socket invention thus include: (1) The socket typically includes a uniform cross section of a regular geometric configuration, preferably a circle, or a multi sided polygon with equal length sides. (2) The density of the socket material may vary axially within recommended limits. (3) The configuration may vary axially. (4) The moment of inertia of the socket subjected to the torque of an impact wrench is in the range of 1 to about 6 times the moment of inertia of the impact wrench, preferably greater than 1. (5) The length verses the nominal diameter of the socket is in the range 1:1 to 6:1. A preferred range is about 2:1 to 4:1. (6) The mass of the socket is in the range of 2 to 3 times of the mass of corresponding standard ASMEB107, 110 ZR sockets (7). The correlation between thread surface engagement (and size) and fastener mass is generally proportional to socket mass (8). The correlation between the torque imparted by an impact wrench and the torque generated thereby to socket tools is facilitated by the mass and geometric design of the “extended” socket tool as demonstrated by the data displayed in
With respect to the designs of such sockets, the moment of inertia of the socket may be calculated by integrating the product of the mass per unit volume of the socket times the volume of the socket taking into account that the body of the socket will rotate about a single axis. As discussed, it is important to maintain essentially a uniform distribution of the mass radially about the axis of the socket. For that reason, the configuration of the socket preferably is discussed; namely, a body comprised of generally circular cross sectional dimensions transverse to the axis of rotation. This is considered an important aspect of the invention in order to avoid undesirable perturbations of the socket when in use. Thus, sections of the socket may be cylindrical, conical, or multi-sided. The axial length of the sections may be varied to accommodate different materials used in the manufacture of the socket and to accommodate clearances with respect to the attachment of the socket to a drive end to a fastener.
Referring therefore to
Multiple variations of the designs discussed are deemed to be within the scope of the invention and equivalents thereto. For example, body sections may comprise of curved shapes. The shapes, however, of the various body sections are preferably symmetric with respect to a plane transverse to a central axis.
For example, the frustoconical configuration of the drive end body section 120 may be inverted with the larger diameter positioned intermediate the sections 120 and 124. The same inversion may apply with respect to the driven end frustoconical section 124.
Yet another configuration that is deemed within the scope of the invention is to include or provide that the socket may be a frustoconical shape between the opposite end faces thereof with the narrow end or narrow diameter of the frustoconical configuration located at the drive end or alternatively at the driven end. The sockets may also have undulating curve surfaces between the opposite ends or an array of cylindrical and frustoconical surfaces joined together from end to end between the opposite end faces of the socket construction.
While there have been set forth embodiments of the invention it is to be understood that the invention is to be limited only by the following claims and equivalents thereof By way of example and not limitation, the socket tool may comprise two or more conical body sections or multiple cylindrical body sections or other curved or shaped sections. Thus, a conical driven end body section may be conical and the drive and body section cylindrical and coaxial with the driven end body section. The driven end and drive end body sections may each be conical with a virtual apex directed toward the drive end or section of the tool. The driven end body section may be shaped with coaxial cylindrical sections or portions as may the drive end section of the socket tool.
This is a continuation-in-part application based on Ser. No. 15/013,736 filed Feb. 2, 2016 entitled “Extended Impact Socket Construction” which is a utility application based on provisional application Ser. No. 62/111,992 filed Feb. 4, 2015 entitled “Extended Impact Socket Construction” for which priority is claimed in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 62111992 | Feb 2015 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 15013736 | Feb 2016 | US |
| Child | 15391401 | US |
