CZ173998A3 - Air spring assembly, piston for such assembly and method of securing springing element to pressed steel piston - Google Patents

Abstract

The air spring assembly (10) has a resilient member (12) and a sliding piston (14). Flanging surface (32) of elastic element (12) is provided in the channel (42) in the sliding piston (14) to be has created an airtight seal that can withstand tensile stresses Tension. A hollow piston (14) to which the piston ring (18) is attached, includes a cylindrical surface (38) with ends (40, 44) coaxial with the lateral a wall (20) of a resilient member (12) about a central axis (22). The method of attaching the sliding piston to the resilient member includes forming a cylindrical surface having an extension at the first end, the curvature of said extension to form inward guided sinusoidal arc, settling the latter an annular flashing surface around said arc and curling the arc against the flashing surface

Description

Technical field

The present invention relates generally to the field of pneumatic spring assemblies and more specifically to a method of attaching a resilient member to a sliding piston

BACKGROUND OF THE INVENTION

It is known in the art to use air spring assemblies for a variety of applications. One such application is the damping or suspension of the tractor and trailer linkage. The pneumatic spring assembly generally comprises a resilient member attached to the piston. The piston is able to slide or retract into the interior of the resilient member, thereby varying the internal volume of the assembly. In addition, the amount of air supplied to the interior of the assembly is adjustable, thereby varying the speed of the spring.

It is known in the art to fasten the piston to the resilient element by using a snap fastener element that surrounds the piston. However, the connection between the snap-fastened element and the resilient element is not able to withstand tensile stress.

In addition, the formation of a larger internal air reservoir would allow less spring deflection, which would translate into a more comfortable ride.

The present invention maintains the conventional outer dimensions of the air spring assembly, but overcomes the prior art tensile stress difficulties, removes the snap-fit element, and increases the internal dimensions of the air spring assembly. · ··· · · · · · · · · · · · · · · · · · ·

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SUMMARY OF THE INVENTION

According to the present invention, a new and improved pneumatic spring assembly is provided.

More specifically, according to the present invention, a method of attaching a plunger having a larger internal volume directly to a resilient member of a pneumatic spring assembly is provided.

According to one aspect of the present invention, the air spring assembly comprises a cylindrical resilient member having first and second spaced edges and an annular region surrounding the second edge, the second edge being within the resilient member. The first edge of the resilient member has a first flashing surface and the second edge has a second flashing surface. The first flashing surface is seated in a groove in the upper flashing ring. The pneumatic spring assembly further comprises a hollow piston having a cylindrical surface coaxial with the resilient member. The first end of the piston is curved to form a channel into which the second flashing surface is seated. The piston is movable relative to the resilient member along the central axis. The piston ring is attached to the piston at the other end.

According to another aspect of the present invention, the interior of the air spring assembly forms an air reservoir that is sealed against air leakage. The amount of air contained in the air reservoir is adjusted via the air inlet located in the upper hem ring.

According to another aspect of the present invention, the air spring assembly may be mounted between two surfaces by means of pins in the upper hem ring and by means of at least one pin and threaded screw in the piston ring.

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According to another aspect of the present invention, the piston for the air spring assembly is formed from a cylindrical surface having an extension at one end. This extension of the cylindrical surface is inwardly curved to form a channel. The other end of the cylindrical surface is funnel-shaped to form a surface for receiving the piston ring.

According to another aspect of the present invention, the piston ring is hermetically welded to the cylindrical surface. The means for mounting the piston to the surface extends through the piston ring. These mounting means are sealed against air leakage.

One advantage of the present invention is to provide a pneumatic spring assembly having an increased internal volume while maintaining the external dimensions of a conventional pneumatic spring.

A further advantage of the present invention is the omission of the snap fastener element used in prior art air spring assemblies.

Another advantage of the present invention is the ease of manufacturing the piston.

Another advantage of the present invention is its ability to withstand tensile stress at the location where the piston is connected to the resilient element.

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Another advantage of the present invention is the use of hermetically welded parts which can be tested on an air leak test bench.

Still other gains and advantages of the present invention will be apparent to those skilled in the art upon reading and understanding the following description.

The present invention can be practiced in the physical form of certain components and the arrangement of these components. Preferred embodiments of these components will be described in more detail in the following description and illustrated in the accompanying drawings which form a part of this description.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a perspective view of a pneumatic spring assembly according to the present invention;

Giant. 2 is an exploded cross-sectional view of a pneumatic spring assembly according to the present invention;

Fig. 3 is a cross-sectional view of a pneumatic spring assembly according to the present invention;

Giant. 4 is a top view of the top hem ring of the present invention;

Giant. 5 is an exploded cross-sectional view of a piston according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a pneumatic spring assembly 10 according to the present invention. This pneumatic spring assembly 10 comprises a resilient member 12.

the sliding piston 14, the upper hem ring 16 and the piston ring 18.

As shown in Figure 2, the resilient member 12 comprises a cylindrical side wall 20 having a central axis 22, a first edge 24 and a second edge 26. The first edge 24 comprises a first flashing surface 28. In a preferred embodiment of the invention the first flashing surface 28 comprises an annular pulling member 29 The top flashing ring 16 includes an annular groove 30 that receives the first flashing surface 28. The second edge 26 of the resilient member 12 includes a second flashing surface 32. The second flashing surface 32 likewise comprises an annular pulling member 33. The side wall 20 bends into itself to form an annular region 34 that surrounds the second edge 26. it will be appreciated that the second edge 26 is disposed within the interior 36 of the resilient member 12.

The piston 14 is substantially hollow and includes a cylindrical surface 38 that is coaxial with the side wall 20 of the resilient member 12 about the central axis 22.

In a preferred embodiment of the invention, the first end 40 of the cylindrical surface 38 comprises an annular channel 42. The second end 44 of the cylindrical surface 38 is funnel-shaped to form a spout 46 for receiving the piston ring 18.

As shown more clearly in FIG. 3, in a preferred embodiment of the invention, the air reservoir 50 of the air spring assembly 10 includes a variable internal volume of the resilient member 12 as well as an internal volume of the piston 14. The top flashing ring 16 and the piston ring 18 form the end boundary of this air reservoir 50.

As can still be seen from FIG. 3, the first hemming surface 28 fits into the groove 30 in such a way as to provide an airtight seal 52 between the upper hemming ring and the resilient member 12. Similarly, the resilient member 12 is secured to the sliding piston 14 by seating the second hemming member. An important feature of the air spring assembly 10 of the present invention is the ability of the seal 54 to withstand tensile stress. Because the seal 54 is able to withstand tensile stress, the range of movement for retracting the piston 14 is increased over prior art air spring assemblies. The piston ring 18 is similarly sealed to the piston 14 by an airtight weld 56 or other fastening means. In a preferred embodiment of the present invention, the air spring assembly 10 is sealed against air leakage at joints between different components.

As can be seen from Figures 3 and 4, the air flow to the air reservoir 50 is controlled by an air inlet 58 located in the top hem ring 16. The amount of air contained in the air reservoir 50 is variable so that the spring speed of the system can be set to meet the requirements of an application.

The upper hem ring 16 and the piston ring 18 are provided with means for allowing the assembly of the air spring assembly 10 between two surfaces (not shown). In a preferred embodiment of the present invention, the upper hem ring 16 includes pins 60 having heads 62 into the interior of the assembly 10. The piston ring 18 includes at least one pin 64 having a head 66 into the interior of the air spring assembly 10.

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A preferred embodiment of the present invention further comprises a threaded bolt 70 extending from the piston ring 18. Screw head 72 is within the air spring assembly 10. The pins 60 are sealed against the top flashing ring 16 to prevent air leakage. Similarly, the pin 64 and bolt 70 are sealed against the piston ring 18 to prevent air leakage.

FIG. 5 shows the initial shape of the piston 14. In a preferred embodiment of the present invention, the piston 14 is made of sheet metal. Initially the cylindrical surface 38 comprises an extension 80 at the first end 40. This extension 80 includes an inwardly guided sinus surface 84 that forms a passage 42. To form a seal 54 between the piston 14 and the resilient member 12, a second flashing surface 32 is seated in the passage 42 and then the sinusoidal surface 84 is corrugated or otherwise tapered against the second flashing surface 32 to form an airtight tensile-resistant connection.

In a preferred embodiment of the present invention, the second end 44 of the cylindrical surface 38 is slightly funnel-shaped to form a spout 46 for receiving an annular edge 90 of the piston ring 18.

The present invention has been described by way of a preferred embodiment. Various modifications and changes will be readily apparent to those skilled in the art upon reading and understanding this disclosure. All such modifications and changes are within the scope of the present invention as set forth in the claims or equivalents thereof.

Claims (14)

PATENT CLAIMS 1. A pneumatic spring assembly comprising: a resilient member having a central axis spaced from the first and second edges, a cylindrical side wall, and a interior, the side wall having an annular region surrounding the second edge and wherein the second edge is in said interior, the first edge has a first annular flashing surface and a second edge has a second annular flashing surface; an upper hemming ring having an annular groove therein for receiving the first hemming surface; a hollow piston having a cylindrical surface with first and second spaced apart ends, the first end attached to the resilient member at the second edge, and wherein said piston is displaceable relative to the resilient member along a central axis; and a piston ring that is attached to the piston at said second end. The air spring assembly of claim 1, wherein the first end of the cylindrical surface forms an inwardly guided sinusoidal surface. The pneumatic assembly 2, wherein the surface has a surface channel therein. a spring according to claim 1, wherein said sinusoidal reception of the second flashing spring is: The pneumatic assembly 3, characterized by the surface being outwardly funnel-shaped spout at said second end. according to claim said cylindrical to form a spring according to claim 3, wherein said piston is sealed against said The pneumatic assembly 4, characterized by the ring having an annular edge, a spout. A pneumatic spring assembly 3, wherein the hem ring comprises: air inlet. according to claim that said top A pneumatic spring assembly 6, wherein the hem ring further comprises: first mounting means for mounting the air spring to the first surface. according to claim that said top of said assembly The pneumatic spring assembly of claim 7, wherein said top flashing ring further comprises: second mounting means for mounting said pneumatic spring assembly to the second surface. Pneumatic assembly 5, characterized by being hermetically welded to the piston. 10. The assembly 3, characterized by the means of a pneumatic spring, in that the springs, by varying the air quantity of said interior. according to claim, the piston ring is further comprising: contained within: 10 ··· ··· ···· • ···· · ···· • · ··· · s ·· ···· · ·· · ······· ·· ··· ·· ·· ·· · * 11. Piston for report pneumatic springs, v y from us .mu.Ci s e t It includes: cylindrical Surface, who has extension at the first end; and Yippee funnelly expanded on the other end to create sponges; and a piston ring having an annular edge that is sealed against said spout. 12. The piston of claim 11, wherein said extension comprises an inwardly directed sinusoidal surface. 13. The piston of claim 12, wherein said piston ring includes mounting means for mounting the piston to the surface. A method of attaching a sliding piston to a resilient member in a pneumatic spring assembly, comprising a resilient member having a central axis spaced from the first and second edges, a cylindrical side wall, and an interior, the side wall having an annular region surrounding the second edge; the edge is in said interior, the first edge has a first annular flashing surface and the second edge has a second annular flashing surface, characterized in that it comprises the following steps: forming a cylindrical surface having an elongation at the first end, curving said elongation to form an inwardly guided sinusoidal arc, seating said second annular flashing surface around said arch, and undulating the arch against the flashing surface. 15. The method of claim 14 wherein said cylindrical surface is funnel-shaped at the other end.