Patent Application
20140259592
The present disclosure relates generally to hand tools. More particularly, this disclosure relates to tools and methods to remove draw wedge bolts in order to remove and replace the kingpin in a vehicle steering assembly.
In a steering assembly of large vehicles such as semi-trailer trucks draw wedge bolts are placed horizontally into cavities of the vehicle steering assembly to secure a vertically placed kingpin. When the kingpin becomes worn or damaged, it must be replaced. To service the kingpin draw wedge bolts must be removed to retrieve the kingpin.
Typical removal methods include either use of hand-hammer or pneumatic hammer applied directly onto draw wedge bolt or use of cutting torch to cut out the draw wedge. During the first removal method, if the hammer is not struck directly onto the small diameter of the draw wedge bolt, the draw wedge bolt may bend and cannot then be extracted. Using the second removal method requires heating areas near the steering assembly and slag must be cleaned from cavity for replacement of new draw wedge bolt and kingpin. The immense heat can also cause unintended damage to the vehicle. For example, rubber hosing and bushings that may be present near the kingpin may be inadvertently melted or compromised from the heat. Either method described is time consuming and may add several hours to the maintenance of the vehicle.
What is required is a tool and method for easy, efficient, time saving way to remove the draw wedge bolts and to enable a mechanic to quickly and easily access the kingpin for maintenance of the steering assembly of a vehicle.
The present application discloses a draw wedge bolt removal tool comprising a single unit impact tool for assisting in the removal of draw wedge bolts that hold a kingpin in place on vehicle steering assemblies. The draw wedge bolt removal tool consists of a threaded smaller diameter end that meets the pitch and diameter of the draw wedge bolt with a clearance length tapered to a larger diameter impact end that will receive the force from a hand or pneumatic hammer to remove the tightened draw wedge bolt. The impact end of the removal tool comprises an inlet hole for insertion of the bolt of the pneumatic hammer. After sufficient impact force is applied to the impact end of the tool the draw wedge bolt will become loosened. Once the draw wedge bolt is loosened, the draw wedge removal tool is unthreaded. In case of a non-threaded draw wedge bolt, the draw wedge bolt removal tool slides over the diameter of draw wedge bolt, impact is made, and the draw wedge removal tool is removed.
Other systems, methods, features and advantages of the invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention.
The forgoing and other aspects, objects, features and advantages of the apparatus and method disclosed will become better understood with reference to the following description, claims, and accompanying drawings, where:
The impact end 105 may comprise an outside edge 125 that is keyed or adapted to be turned by a wrench or a socket. This feature assists the mechanic in affixing and removing the draw wedge bolt removal tool 100 from the draw wedge bolt.
This tool may be part of a kit. The tool kit includes adaptors 705 which affix to the threaded end of the draw wedge tool 100 in order to accommodate different sized draw wedge bolts 810. While several different vehicle manufacturers use roughly the same draw wedge design to hold in the kingpin 805, the various manufacturers use different sized draw wedge bolts 810 with different thread pitches. This kit provides the mechanic different sized adapters 705 to screw onto the threaded end of the tool to accommodate the standard sized draw wedge bolts 810 for different steering system assemblies. Another way to accommodate different sized draw wedge bolts is to have the diameter of the threaded end 110 of the tool large enough to accommodate all the various sizes of draw wedge bolts 810. Thread inserts can be inserted into the cavity 120 of the threaded end 110 to accommodate the varying sizes of the draw wedge bolts 810.
The tool 100 may be tapered so a diameter of the structure is largest at the impact end 105 and decreases to the threaded end 110. The tapering provides for both a more natural hand grip for the mechanic on the tool 100 and provides for a larger surface area on the impact end 105 to strike. In addition it provides a narrower end at the threaded end 110 which may be beneficial when performing maintenance in the tight area of the steering wheel assembly.
The tool 100 can be constructed of various types of materials including high strength metal alloys. Preferably, the tool 100 is constructed of tool steel which refers to a variety of carbon and alloy steels that are particularly well-suited to be made into tools. Their suitability comes from their distinctive hardness, resistance to abrasion, their ability to hold a cutting edge, and/or their resistance to deformation at elevated temperatures (red-hardness). Tool steel is generally used in a heat-treated state. Many high carbon tool steels are also more resistant to corrosion due to their higher ratios of elements such as vanadium and niobium. With a carbon content between 0.7% and 1.5%, tool steels are manufactured under carefully controlled conditions to produce the required quality. The manganese content is often kept low to minimize the possibility of cracking during water quenching. However, proper heat treating of these steels is important for adequate performance, and there are many suppliers who provide tooling blanks intended for oil quenching.
Tool steels are made to a number of grades for different applications. Choice of grade depends on, among other things, whether a keen cutting edge is necessary, as in stamping dies, or whether the tool has to withstand impact loading and service conditions encountered with such hand tools as axes, pickaxes, and quarrying implements. In general, the edge temperature under expected use is an important determinant of both composition and required heat treatment. The higher carbon grades are typically used for such applications as stamping dies, metal cutting tools, etc.
In one embodiment, the tool 100 is comprised of shock resisting type steel. S-type tool steel is designed to resist shock at both low and high temperatures. A low carbon content is required for the necessary toughness (approximately 0.5% carbon). Carbide-forming alloys provide the necessary abrasion resistance, hardenability, and hot-working characteristics. This family of steels displays very high impact toughness and relatively low abrasion resistance, it can attain relatively high hardness (HRC 58/60).
After the draw wedge bolt is loosened, the mechanic will remove the draw wedge bolt removal tool 100 from the draw wedge bolt 810. Next, the mechanic will remove the draw wedge bolt from the steering assembly. Following removal, the mechanic will remove and replace the kingpin 805 as necessary. Following installation of the kingpin 805, the mechanic will reinstall the draw wedge bolts into the steering assembly cavity and reinstall the nut 905 onto the draw wedge bolt 810. The mechanic will tighten the nut 905 to the manufacturer recommended torque.
While the description above refers to particular embodiments of the present invention, it should be readily apparent to people of ordinary skill in the art that a number of modifications may be made without departing from the spirit thereof. The accompanying claims are intended to cover such modifications as would fall within the true spirit and scope of the invention. The presently disclosed embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than the foregoing description. All changes that come within the meaning of and range of equivalency of the claims are intended to be embraced therein. Moreover, the applicants expressly do not intend that the following claims “and the embodiments in the specification to be strictly coextensive.” Phillips v. AHW Corp., 415 F.3d 1303, 1323 (Fed. Cir. 2005) (en banc).
