1. Field of the Invention
The present invention relates to a tool used in performing retrofit operations on motor vehicle axle and suspension assemblies. Preferred retrofit operations are described in 115 Proia, and the purpose of these preferred retrofit operations is to convert a motor vehicle axle that does not pivot (in a horizontal plane (that is, a non-self-steering axle) into an axle that does pivot in a horizontal plane through some range of permitted angular motion (that is, a self-steering axle). One especially potential favorable application of these retrofit operations is to convert axles on trailers (pulled by tractor trailers) and/or trailer dolly sub-assemblies, and the tool of the present invention is believed to be especially advantageous in performing that specific type of retrofit operation.
2. Description of the Related Art
Good background information on self-steering axle assemblies and/or retrofit operations to create self-steering axle assemblies is set forth in 115 Proia; U.S. Pat. No. 5,220,972 (“972 Proia”) and/or U.S. Pat. No. 6,679,517 (“517 Proia”). The reader is especially referred to FIGS. 23A and 23B of 115 Proia because these show an important aspect of the retrofit that relates to the alignment tool of the present invention, to be discussed in subsequent sections of this document. Specifically, springs, like spring 269A of FIGS. 23A and 23B of 115 Proia must have some transverse direction clearance within the recesses in the hanger parts so that these springs can pivot in the horizontal plane about their vertical centerlines, so that the attached axle can pivot in a horizontal plane. This pivoting is shown (not necessarily to scale) in FIGS. 23A and 23B of 115 Proia. Even a relatively small range of pivoting motion of the spring (say, 3 degrees) can be very helpful in making effective and efficient self steering. Note the transverse direction clearance: (i) between spring 269A and hangar 238A; and (ii) between spring 269A and hanger 265A. This is the clearance that allows the pivoting of the spring and the axle mechanically connected to it.
The present invention recognizes that it is critical that, during retrofit operations, that the spring be precisely centered in the transverse direction relative to the hanger in which the spring rests. The spring must maintain its centering as retrofit work is performed on other parts of the self steering assembly, such as the axle, 45 degree brackets and the like (see 115 Proia). The springs (on at either end of the axle) cannot be allowed to pivot as the other work is being done because this leads to misalignment of the suspension system, which is highly unfavorable and requires correction until the springs (one at either end of the axle) are both properly aligned. To be more specific the longitudinal centerline of each spring must be: (i) centered in the hanger; and (ii) aligned with the forward/reverse direction (as defined by the vehicle or dolly frame).
The present invention is directed to a tool used to maintain proper alignment and centering of the spring during retrofit operations (such as retrofit operations to create a self-steering axle. In most cases, four alignment tools, according to the present invention, are used to maintain spring/hanger alignment and centering during retrofit. More specifically, two springs (one at each end of the axle) must be held in alignment, and one tool is used at each longitudinal end of each spring, thereby making a total of four spring/hanger junctures where alignment must be established and maintained and a corresponding total of four tools to maintain this alignment. The tools are removed from the spring/hanger junctures when the retrofit is completed.
Various embodiments of the present invention may exhibit one or more of the following objects, features and/or advantages:
According to an aspect of the present invention, an alignment tool is used with a hanger and a spring. The tool includes: an arm spacing structure (that defines a longitudinal direction and a transverse direction); a first arm structure; and a second arm structure. The first arm structure is rigidly mechanically connected to the arm spacing structure. The second arm structure is rigidly mechanically connected to the arm spacing structure so that it is spaced apart from the first arm structure. The first arm structure includes an outside facing surface and an inside facing surface. The second arm structure includes an outside facing surface and an inside facing surface. The first and second arms are structured, located and/or connected so that: (i) the inside facing surfaces of the first and second arms mutually oppose each other in a parallel spaced apart relationship, where the spacing is approximately equal to a width of the spring, and (ii) the outside facing surfaces of the first and second arms are both inclined with respect to the longitudinal direction such that the first and second arm structures are each narrower at their respective front ends than at their respective rear ends.
According to further aspect of the present invention, a retrofit of an axle assembly is performed. The axle assembly includes a spring and a hanger, with the hanger defining a spring-receiving recess. The method comprising the steps of: (i) providing an alignment tool having two arm structures; (ii) inserting the alignment tool into the spring-receiving recess of the hanger so that the arm structures of the alignment tool are disposed along opposing transverse edges of the spring so that a longitudinal centerline of the spring is centered in and aligned with the hanger; (iii) subsequent to the inserting step, retrofitting the axle assembly; and (iv) subsequent to the retrofitting step, removing the alignment tool from the spring receiving recess so that a longitudinal centerline of the spring remains centered in and aligned with the hanger.
The present invention will be more fully understood and appreciated by reading the following Detailed Description in conjunction with the accompanying drawings, in which:
Tool 5 is a specially designed tool for accurate and easy installation of all tandem or spring axle parts in retrofitting an axle to convert it into a self steering axle. Due to the fact that all manufactured items, such as suspension hangers, torque bars and springs (see, generally 115 Proia) have relatively loose tolerancing, achieving and maintaining good alignment of the axle (that is, perpendicular to the driving direction) and other parts is a very difficult challenge. However, alignment is critical because the wheels and tires that are attached to the axle must be well aligned for efficient and safe driving. While conversion of an axle to a self-steering axle can improve fuel economy and handling of a tractor trailer, or tandem tractor trailer, these improvements are defeated in their purpose if the axle ends up becoming misaligned through the retrofitting operation that creates it. With the tool of the present invention, good alignment can be reliably ensured through the retrofit. Furthermore, the tool of the present invention allows a single individual worker to perform the retrofit.
Once each pair of arms is assembled, as described in the preceding paragraph, the arms need to be mechanically connected to each other, at a precise mutual distance and alignment, by the arm spacer members 1. As shown in
As best shown in
Any and all published documents mentioned herein shall be considered to be incorporated by reference, in their respective entireties. The following definitions are provided for claim construction purposes:
Present invention: means “at least some embodiments of the present invention,” and the use of the term “present invention” in connection with some feature described herein shall not mean that all claimed embodiments (see DEFINITIONS section) include the referenced feature(s).
Embodiment: a machine, manufacture, system, method, process and/or composition that may (not must) be within the scope of a present or future patent claim of this patent document; often, an “embodiment” will be within the scope of at least some of the originally filed claims and will also end up being within the scope of at least some of the claims as issued (after the claims have been developed through the process of patent prosecution), but this is not necessarily always the case; for example, an “embodiment” might be covered by neither the originally filed claims, nor the claims as issued, despite the description of the “embodiment” as an “embodiment.”
First, second, third, etc. (“ordinals”): Unless otherwise noted, ordinals only serve to distinguish or identify (e.g., various members of a group); the mere use of ordinals shall not be taken to necessarily imply order (for example, time order, space order).
Mechanically connected: Includes both direct mechanical connections, and indirect mechanical connections made through intermediate components; includes rigid mechanical connections as well as mechanical connection that allows for relative motion between the mechanically connected components; includes, but is not limited, to welded connections, solder connections, connections by fasteners (for example, nails, bolts, screws, nuts, hook-and-loop fasteners, knots, rivets, quick-release connections, latches and/or magnetic connections), force fit connections, friction fit connections, connections secured by engagement caused by gravitational forces, pivoting or rotatable connections, and/or slidable mechanical connections.
The present application claims priority to U.S. provisional patent application Ser. No. 61/503,657, filed on 1 Jul. 2011, and U.S. patent application Ser. No. 13/070,140, filed on 23 Mar. 2011 (published as publication number 20110248115 and herein referred to as “115 Proia”); all of the foregoing patent-related document(s) are hereby incorporated by reference herein in their respective entirety(ies).
Number | Date | Country | |
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61503657 | Jul 2011 | US |
Number | Date | Country | |
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Parent | 13070140 | Mar 2011 | US |
Child | 13540025 | US |