Presently fasteners are made with various recesses and matched driving tools, or bits, such as the Phillips® design, Torx®, straight walled hexagon, and other multi-fin geometries. Driving bits comprise driving walls and faces designed to fit within a recessed socket area of the fastener. However, to enable insertion of the driver into the recessed socket area, there must be some clearance between the driving tool and the recessed socket area of the fastener. As a result, the area of contact is typically less than full face-to-face contact between the driving tool and the recessed socket area of the fastener. In addition, the driving walls of the driving bit are longer than the recessed socket area of the fastener is deep such that a significant portion of the driving walls is not inserted into the recessed socket area. Consequently, when torque is applied by the driving bit to the fastener, the forces applied to the fastener head and driving walls are concentrated in localized stress regions. These localized stresses may lead to breakage of the bit. Efforts to increase the strength of the driving walls commonly focuses on the use of stronger materials or increasing the thickness of the driving walls. These efforts may provide some increased strength but the results are often limited due, at least in part, to size constraints of the related geometries.
Methods and apparatus for an enhanced driving bit according to various aspects of the present technology include a bit comprising a plurality of driving surfaces having a limited length and a shoulder portion positioned between the driving surfaces and a mid-body portion of the bit. The length of the driving surfaces is selected to allow complete insertion into a recessed socket area of a fastener such that the entire driving surface is positioned within the recessed socket area. The shoulder surface is configured to distribute localized stresses away from the driving surfaces to the mid-body portion more efficiently to reduce a potential for breakage of the driving surfaces during use.
A more complete understanding of the present technology may be derived by referring to the detailed description when considered in connection with the following illustrative figures. In the following figures, like reference numbers refer to similar elements and steps throughout the figures.
The present technology may be described in terms of functional block components and various processing steps. Such functional blocks may be realized by any number of components configured to perform the specified functions and achieve the various results. For example, the present technology may employ various types of materials, fastening devices, driver systems and the like, which may carry out a variety of functions. In addition, the present technology may be practiced in conjunction with any number of processes such as the manufacture of drivers for fasteners, mechanical attachment, and torque transmitting systems, and the system described is merely one exemplary application for the invention. Further, the present technology may employ any number of conventional techniques for metalworking, component manufacturing, tooling fabrication, and/or forming surfaces.
Methods and apparatus for an enhanced driving bit according to various aspects of the present technology may operate in conjunction with any suitable torque delivery system. Various representative implementations of the present technology may also be applied to any device capable of being inserted into and rotating a fastener.
Referring now to
The bit 102 may comprise any suitable material capable of withstanding torque forces between the fastener 104 and the bit 102. For example, the bit 102 may comprise a metal or alloy that may be hardened or anodized. The material may also be capable of being subjected to one or more types of machining operations such as grinding, cutting, heading, hobbing, cold forming, or the like.
The shank portion 106 allows the bit 102 to be coupled to a device to allow the bit 102 to be rotated and apply a torque to the fastener 104. The shank portion 106 may comprise any suitable size or shape and may be configured in any suitable fashion. For example, in one embodiment, the shank portion 106 may comprise a series of sidewall elements forming hexagonal shape to allow the bit 102 to be selectively inserted into a receiving mechanism such as a chuck of a mechanical screw gun, drill, robotic arm, or the like. In an alternative embodiment, the shank portion 106 may comprise a circular shape suitably configured to be coupled to a handle to form a manually operated device such as a screw driver.
The mid-body section 108 extends at least part way between the shank portion 106 and the driving portion 112. The mid-body section 108 may be formed integrally with the shank portion 106 to create single unitary structure or may have a separate shape from the shank portion 106. For example, the bit 102 may be formed from a single metal rod, wherein the mid-body section 108 retains the original dimensions of the metal rod and the shank portion 106 is subjected to a machining operation to form a surface that may be used to couple the bit 102 to a device such as a drill or other like device that is configured to rotate the bit 102.
Referring now to
The driving portion 112 may comprise any suitable shape or size for engaging the recessed socket area 114 of the fastener 104. For example, the driving portion 112 may comprise a shoulder surface 208 extending longitudinally away from the mid-body section 108 and a torque surface 202 extending outwardly from the shoulder surface 208. The torque surface may be suitably configured to engage or otherwise substantially conform to a surface located within the recessed socket area 114.
The torque surface 202 may extend between a base portion 204 and an end portion 206. The torque surface 202 may be aligned substantially parallel to the shank portion 106 or the mid-body section 108. Alternatively, the torque surface 202 may taper towards a longitudinal axis 200 of the bit 102. A distance between the base portion 204 and the end portion 206 may comprise a length selected such that the entire torque surface 202 may be inserted into the recessed socket area 114 so that the shoulder surface 208 will abut the recessed socket area 114 and no portion of the torque surface 202 is positioned outside of the recessed socket area 114 when the bit 102 is used to torque the fastener 104. Limiting the length of the distance between the base portion 204 and the end portion 206 ensures that the entire length of the driving surface is in contact with the recessed socket area 114 and is being used to transfer a torque to the fastener 104. This substantially eliminates a situation where one portion of an individual torque surface 202 is applying a torque to the fastener 104 and a second portion of the individual torque surface 202 is not applying a torque because it is not in contact with the recessed socket area 114 of the fastener 104. For example, the torque surface a prior art style driver bit has a length greater than the recessed socket area 114 of a standard screw head resulting in the torque surface the prior art style driver bit extending outward beyond the top of the screw head.
For example, in one embodiment, the distance between the base portion 204 and the end portion 206 may be less than two tenths of an inch when the recessed socket area 114 has a depth of about two tenths of an inch. In a second embodiment, the distance between the base portion 204 and the end portion 206 may be less than about five one hundredths of an inch when the recessed socket area 114 has a depth of between about five one hundredths of an inch and seven one hundredths of an inch.
In alternative embodiments, the distance between the base portion 204 and the end portion 206 may be determined according to a relationship between a length of the driving portion 112 and the shoulder surface 208. Referring now to
Referring now to
Each fin 302 may comprise a driving wall 304, a removal wall 306, and a first transition wall extending between the driving wall 304 and the removal wall 306. The torque surface may also comprise a second transition wall extending between the driving wall 304 of a first fin and the removal wall 306 of a second fin. Each of these walls may be suitably configured to mate to a corresponding surface within the recessed socket area 114 of the fastener 104. For example, the driving wall 304 may comprise a constant fin height from the base portion 204 to the end portion 206 that equals a height of a corresponding driving surface within the recessed socket area 114. In addition, the driving wall 304 may be configured to be aligned with the axis 200 of the bit 102 such that there is substantially complete face-to-face contact between the driving wall 304 and the driving surface within the recessed socket area 114 during engagement. This allows the driving force to be spread across a larger area than is achievable through known fastener systems that only provide localized contact between the driving surface and a corresponding surface within the fastening device.
Similarly, the removal wall 306 may be configured to have the same dimensions as the removal surface 212 such that there is substantially complete face-to-face contact between the removal wall 306 and a corresponding removal surface within the recessed socket area 114 during engagement. For example, in one embodiment, the removal wall 306 may form a substantially mirror image of the driving wall 304.
Alternatively, in a second embodiment, the removal wall 306 may form a non-vertical line relative to the axis 200 of the bit 102 as it extends from the base portion 204 to the end portion 206 in an equivalent manner to the removal surface. The non-vertical line may lie on an angle that causes the first transition wall to become progressively smaller as it descends toward the end portion 206. Likewise, as the driving wall 304, the removal wall 306, the first transition wall, and a second transition wall progress to the end portion 206 of the torque surface 202, each surface may taper inwardly towards the axis 200 such that the polygonal shape of the fins have a smaller area at the end portion 206 than at the base portion 204. The end result is that the torque surface 202 tapers the same in every dimension as the recessed socket area 114 and is the same size at every corresponding position to the recessed socket area 114. Accordingly, when the bit 102 is inserted into the recessed socket area 114, the entire the torque surface 202 is in contact with every surface of the recessed socket area 114 both longitudinally and horizontally. The similar geometry allows the torque surface 202 to be wedged into the recessed socket area 114 to create a substantially 100% wedged fit between the bit 102 and the fastener 104 in all directions and with no portion of the torque surface 202 extending out of the recessed socket area 114.
This wedged fit may further align the bit 102 and the fastener 104 during use by reducing tolerances between the torque surface 202 and the recessed socket area 114. Reduced tolerances may result in a decreased likelihood that the bit 102 may wobble within the recessed socket area 114 when the driving force or removal force is being applied which reduces the chances of cam out and/or disengagement. The wedge fit during use may also decrease plastic deformation on the driving wall 304 and the removal wall 306 which results in decreased wear on the torque surface 202 and the recessed socket area 114.
Referring now to
The tapered nose section 1002 may help center the torque surface 202 during insertion or allow the torque surface 202 of a customized bit to be indexed more easily to a correct position and provide complete insertion of the driving portion 112 into the recessed socket area 114. The tapered nose section 1002 may also allow for improved engagement between the torque surface 202 and the fastener 104 be reducing or eliminating a radius at an end of the torque surface 202. For example, standard flat nosed driver bits often comprise a radius of at least 0.020 inches at the tip that prevents the driver bits from getting full engagement at insertion depth.
The tapered nose section 1002 may be formed in any suitable manner to allow for a tip of the driving portion 112 to be adapted to various types of recessed socket areas 114. For example, referring now to
In prior art driver bits, the transition between the torque surface 202 and the mid-body section 108 is abrupt commonly forms a substantially ninety degree angle. The abrupt transition creates a location of increased stress that increases a likelihood that one or more fins of the torque surface 202 will break during use since the torque forces are not efficiently transferred from the driving portion 112 to the mid-body section 108 of the bit 102.
Referring again to
Referring now to
By shortening the length of the driving portion 112 to ensure full insertion into the recessed socket area 114 and incorporating the shoulder portion, overall strength of the driver bit 102 is increased and the likelihood of fin or torque surface 202 breakage is reduced. For example, in testing, a prior art Torx® style driver bit was inserted into a fastener head and torqued until the torque surface 202 broke. During testing, the prior art driver bit broke when subjected to approximately fifty-five to sixty inch pounds of torque. A driver bit 102 of the present technology was then subjected to the same testing and broke at approximately ninety-five to one hundred five inch pounds of torque. Similar increases in strength were found in other styles of driver bits evidencing the benefits of the reduce length of the driving portion 112 and the incorporation of the shoulder surface 208 between the driving portion 112 and the mid-body section 108.
The shoulder surface 208 and the driving portion 112 may be formed by any suitable method such as by forming, forging, casting, cutting, grinding, milling, and the like. In one embodiment, the shoulder surface 208 and the driving portion 112 may be formed through a metal operation such as cold heading or hobbing. For example, referring now to
In an alternative embodiment, the shoulder surface 208 and the driving portion 112 may be formed through a series of computerized numerical controlled (“cnc”) machining steps. For example, the torque surface 202 may initially be milled on an end portion of a metal rod. The metal rod may then be positioned within a lathe to form the shoulder surface 208 and the tapered nose section 1002.
The particular implementations shown and described are illustrative of the invention and its best mode and are not intended to otherwise limit the scope of the present invention in any way. Indeed, for the sake of brevity, conventional manufacturing, connection, preparation, and other functional aspects of the system may not be described in detail. Furthermore, the connecting lines shown in the various figures are intended to represent exemplary functional relationships and/or steps between the various elements. Many alternative or additional functional relationships or physical connections may be present in a practical system.
In the foregoing specification, the invention has been described with reference to specific exemplary embodiments. Various modifications and changes may be made, however, without departing from the scope of the present invention as set forth in the claims. The specification and figures are illustrative, rather than restrictive, and modifications are intended to be included within the scope of the present invention. Accordingly, the scope of the invention should be determined by the claims and their legal equivalents rather than by merely the examples described.
For example, the steps recited in any method or process claims may be executed in any order and are not limited to the specific order presented in the claims. Additionally, the components and/or elements recited in any apparatus claims may be assembled or otherwise operationally configured in a variety of permutations and are accordingly not limited to the specific configuration recited in the claims.
Benefits, other advantages and solutions to problems have been described above with regard to particular embodiments; however, any benefit, advantage, solution to problem or any element that may cause any particular benefit, advantage or solution to occur or to become more pronounced are not to be construed as critical, required or essential features or components of any or all the claims.
As used herein, the terms “comprise”, “comprises”, “comprising”, “having”, “including”, “includes” or any variation thereof, are intended to reference a non-exclusive inclusion, such that a process, method, article, composition or apparatus that comprises a list of elements does not include only those elements recited, but may also include other elements not expressly listed or inherent to such process, method, article, composition or apparatus. Other combinations and/or modifications of the above-described structures, arrangements, applications, proportions, elements, materials or components used in the practice of the present invention, in addition to those not specifically recited, may be varied or otherwise particularly adapted to specific environments, manufacturing specifications, design parameters or other operating requirements without departing from the general principles of the same.
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Number | Date | Country | |
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20170106507 A1 | Apr 2017 | US |