BASSANI, Joel (138 Colonial Court, Emmaus, PA, 18049, US)
| I claim:
1. An air spring mounting system for a frame having a threaded fastener, comprising: an air spring body, including an upper plate; a stud extending from the upper plate, the stud having a first threaded portion and a second portion between the first portion and the upper plate, the second portion having an outside diameter less than an outside diameter of the first portion, the first portion being threaded for connecting to a threaded fastener associated with the frame.
2. The air spring as claimed in claim 1 , wherein the second portion is unthreaded.
3. The air spring as claimed in claim 1 , further comprising means for biasing the upper plate toward a frame when the stud engages a fastener in the frame.
4. The air spring as claimed in claim 3, wherein said means for biasing is disposed on the upper plate adjacent the stud.
5. The air spring as claimed in claim 3, wherein said means for biasing is disposable between a threaded fastener and a frame.
6. The air spring as claimed in claim 3, wherein said means for biasing is one of a coil spring, a leaf spring, and an elastomeric spring.
7. A system for mounting an air spring between vehicle frame components, comprising: an air spring body, including an upper plate having threaded hole means; a stud mountable on a frame part to which the air spring is to be mounted, so that the stud extends from the frame part, the stud having a first threaded portion and a second portion between the first portion and the upper plate, the second portion having an outside diameter less than an outside diameter of the first portion, the first portion being threaded for connecting to a threaded fastener associated with the frame.
8. The air spring as claimed in claim 7, wherein the second portion is unthreaded.
9. The air spring as claimed in claim 7, further comprising means for biasing the upper plate toward the frame part when the stud engages a fastener in the frame. |
A Device for Mounting a Vehicle Air Spring
Background and Summary
In vehicles having air springs as part of a suspension system, for example, heavy trucks, the air springs are typically mounted between vehicle components. For example, air springs are mounted between the axle and vehicle frame to suspend the frame, and between the cab and the frame to suspend the cab relative to the frame. Air springs include fittings to be connected to an air source for increasing or decreasing the pressure in the spring, as desired or necessary for adjusting the spring rate.
In one type of mounting arrangement for a cab suspension, an air spring is mounted by a post provided on a top side of the air spring to a hole in a cab lower frame member. After mounting the post in the hole, it is usually necessary to rotate the air spring to orient the air inlet valve fitting for connection with the air supply.
Many known mounting system require access to the opposite side of the cab frame hole for mounting and removing the air spring. For convenience, however, it is preferred to use a blind hole mounting system, so that access is needed to one side only of / the cab frame member. One way of attaching to a blind hole is by using a threaded hole and threaded post on the air spring.
Threaded posts pose a problem in that rotating ' the mounted air spring for access to the air fitting also changes the tightness of the threaded fastener, either loosening the fastener, or being prevented from rotating the spring because of the tightness of the fastener. To get around this problem, the art shows other devices, clip mounting devices and unthreaded collars that are expensive to manufacture and complicated to use.
There is a need for a mounting device for an air spring into a blind hole that allows rotation of the air spring after mounting, but does not alter the mounting integrity, that is, does not tighten or loosen the mounting device by rotation of the air spring.
The invention solves this problem with a device for mounting an air spring to a frame element having a blind hole that is threaded or has an installed threaded nut. The
invention includes an upstanding stud mounted on an upper plate of an air spring, the stud having a first threaded portion at an end of the stud, and a second unthreaded portion between the threaded portion and the upper plate, the unthreaded portion having a diameter less than a diameter of the threaded portion.
According to the invention, the stud of the air spring may be threaded through the hole or nut of a frame part until the threaded portion passes through and the unthreaded portion resides in the nut or hole. The air spring may be turned relative to the frame part without tightening or loosening the stud from the hole by keeping the unthreaded portion in the hole or nut.
According to another embodiment, the stud may be provided on the frame part and the threaded hole or installed nut provided on the upper plate of the air spring.
According to another aspect of the invention, a spring may be disposed between a threaded nut and the frame provide tension on the stud, that is, biasing the upper plate of the air spring toward the threaded hole or nut in the mounting bracket to provide tension while turning the threaded portion of the stud in the threaded hole or nut, in particular on the final turn. According to an alternative embodiment, the spring may be disposed on the upper plate of the air spring adjacent a bottom end of the stud.
Brief Description of the Drawings
The invention will be better understood with reference to the following detailed description read in conjunction with the appended drawings, in which:
Figure 1 is section view of an air spring in accordance with the invention mounted between a frame part and a suspended component;
Figure 2 is a section view of an upper end portion of the air spring of the invention and a portion of the suspended component; and,
Figure 3 is a section view of an alternative embodiment having a stud provided on a frame part.
Detailed Description
The drawings show in simplified form an air spring mounted between frame parts. The drawings are not to scale and certain elements have been enlarged for the purposes of illustration. The description of the invention that follows is related to an air spring for a heavy truck cab suspension as an example of an application of the invention. As will be appreciated, the invention may be applied to any air spring mounting where turning of the air spring may be desired or advantageous after mounting the air spring to a component.
Figure 1 shows an air spring 10 mounted between a cab frame part or mounting bracket 30 and a chassis frame part 40. The air spring 10 includes an upper plate 12 having an upstanding stud 14, a flexible member forming an air chamber 16 for containing air under pressure to provide the spring function, and a base 18 for mounting the air spring to a lower bracket or frame part 40.
An air fitting 20 is shown here incorporated on the base 18 and is connected to a passage (not shown) that communicates with an interior of the air chamber 16 to deliver compressed air to the bag. In typical installations, the air fitting 20 is connected to a vehicle air source to provide compressed air as commanded by a suspension control system (also not illustrated).
The air spring 10 is attached to a threaded nut 32 installed in a fixed manner in the cab mounting bracket 30 by way of threads formed on the stud 14.
Turning now to Figure 2, an enlarged view of the top portion of the air spring 10 is shown. The stud 14 has a threaded portion 22 at an end remote from the upper plate 12, and a second portion 24 between the threaded portion 22 and the upper plate 12. The second portion 24 is preferably non-threaded and has an outer diameter less than an outer diameter of the threaded portion. According to an embodiment, the non- threaded second portion 24 has an outside diameter allowing it to pass through the threaded nut or threaded hole in the frame without engaging the nut or hole threads. The outside diameter of the non-threaded second portion 24 may be equal to an interior diameter (diameter measured at the tips of the threads) nut or threaded hole.
According to the invention, the stud 14 is threaded into the nut past the threaded portion 22, so that the non-threaded portion 24 is free to rotate in the nut. The air spring may hang temporarily by the threaded portion without damage while being manipulated. This allows the air spring to be rotated to a position to align the air fitting for connection with the vehicle air supply line.
The mounting device of the invention may further include a tension element 34, for example, a coil spring, leaf spring, or elastomeric element, positioned between the threaded nut 32 and the cab frame member 30 to maintain tension on the air spring stud threads during turning, in particular, when the during the last thread turn.
A tension element may be disposed, alternatively, between the frame member 30 and the upper plate 12.
The threaded nut 32 may be installed in the frame or bracket 30 by a convenient method, such as welding. Alternatively, the frame or bracket 30 may be formed with a threaded hole.
An alternative arrangement within the scope of the invention is illustrated in Figure 3. A threaded nut 40 (or alternatively, a threaded hole) is provided or formed on the upper plate 42 of the air spring 10. A tension element 34 may also be provided between the threaded nut 40 and an inner surface of the upper plate 42. A partly threaded stud 50 in accordance with the invention is mountable to the cab frame member 30 so as to protrude from the cab frame member in the mounting position of the air spring 10. A support 52 may be provided on the frame member 30 for the stud. In this arrangement, the upper plate 42 is also formed with a pocket or recess 44 to receive the end of the stud 50 and maintain the integrity of the air chamber.
The invention has been described in terms.of preferred principles, embodiments, and components; however, those skilled in the art will understand that equivalents may be substituted for what is here described without departing from the scope of the invention as defined by the appended claims.