FIELD OF THE INVENTION

The present invention relates, in general, to air springs and, more particularly, this invention relates to arrangement and method for sealing ends of an air spring without use of conventional mechanical fasteners, mechanical actions, such as crimping or clamping, or bonding or adhesives.

BACKGROUND OF THE INVENTION

As is generally well known, conventional air springs are employed in numerous applications to absorb shock loads imparted on movable parts or exert a force onto a part connected to one end thereof. Air spring includes a pair of spaced apart end members and an axially expandable elastomeric sleeve member disposed between and attached to the end members so as to form a pressurized chamber therein. The internal pressurized fluid, generally air, absorbs most of the shock impressed upon or experienced by one of the spaced end members by which the air spring is mounted. Generally, the end members move inwards and towards each other and also away and outwards from each other upon absorbing the imparted shock. In railway applications, air springs have been employed in brake riggings so as to generate and apply force, upon inflation, onto components of the brake rigging, resulting in brake shoe engagement with wheels. Deflation of the air spring cancels such brake shoe engagement. On example of such railway application is taught in U.S. Pat. No. 7,931,130 issued to Ring on April 26, 2011 and owned by the assignee of the invention.

Prior to conception and design of the instant invention, as best known by the applicant, in order to seal ends of the elastomeric sleeve member with respective end members, conventional air springs require secondary operations using mechanical fasteners, mechanical actions, such as crimping or clamping, or adhesives. Such secondary operations are associated with greater than desirable cost.

Therefore, there is a need for an arrangement and method for sealing ends of an air spring that do not require use of conventional mechanical fasteners, mechanical actions, such as crimping or clamping, or bonding or adhesives.

SUMMARY OF THE INVENTION

The invention provides an arrangement for attaching and sealing ends of an air spring that does not require conventional fasteners, mechanical fastening operations or bonding and/or adhesives. Specifically, the arrangement provides for an interlock of each end of the flexible elastomeric sleeve with the respective end member and use of air pressure to seal the juncture of the flexible elastomeric sleeve and the end member at such interlock. OBJECTS OF THE INVENTION

It is, therefore, one of the primary objects of the instant invention to provide an arrangement for sealing ends of an air spring that does not require use of conventional mechanical fasteners, mechanical actions, such as crimping or clamping, bonding or adhesives.

Another object of the instant invention is to provide an arrangement for sealing ends of an air spring that uses air pressure to force ends of the flexible elastomeric sleeve member against respective end members.

A further object of the instant invention is to provide an arrangement for sealing ends of an air spring that includes an interlock between each end of the flexible elastomeric sleeve member and a flange of a respective end member sufficient to maintain structural and sealing integrity of the air spring during operation.

A further object of the instant invention is to provide a method for attaching and sealing ends of an air spring that does not require use of conventional mechanical fasteners, mechanical actions, such as crimping or clamping, bonding or adhesives .

Yet another object of the instant invention is to provide an air spring utilizing the above described arrangement that can be employed on railway brake riggings.

In addition to the several objects and advantages of the present invention which have been described with some degree of specificity above, various other objects and advantages of the invention will become more readily apparent to those persons who are skilled in the relevant art, particularly, when such description is taken in conjunction with the attached drawing Figures and with the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial elevation cross-sectional view of an air spring incorporating attachment and sealing arrangement in accordance with one embodiment of the instant invention; FIG. 2 is a partial elevation cross-sectional view of the attachment and sealing arrangement in accordance with another embodiment of the instant invention; and

FIG. 3 is a partial elevation cross-sectional view of the attachment and sealing arrangement in accordance with yet another embodiment of the instant invention.

BRIEF DESCRIPTION OF THE VARIOUS EMBODIMENTS OF THE INVENTION

Prior to proceeding to the more detailed description of the present invention, it should be noted that, for the sake of clarity and understanding, identical components which have identical functions have been identified with identical reference numerals throughout the several views illustrated in the drawing figures.

Now in reference to FIG. 1-3, therein is partially illustrated an air spring, generally designated as 10.

Conventionally, the air spring 10 includes a first end member 20 and a second end member 30 that is spaced apart from the first end member 20 along a longitudinal axis 12. Conventionally, such end members 20 and 30 are manufactured from metallic material, such as steel. A flexible elastomeric sleeve 40 is disposed between the first and second end members, 20 and 30 respectively, along the longitudinal axis 12. The elastomeric sleeve 40 is generally either a diaphragm or a bellow defining a hollow interior or chamber 42. The elastomeric sleeve 40 reciprocally expands along the longitudinal axis 12 upon inflation thereof, when a fluid, generally air, is introduced under pressure into the hollow interior 42 through a port in one of the end members 20 or 30 and contracts along the longitudinal axis 12 when the air pressure is evacuated from the hollow interior 42. Conventionally, the attachment and sealing of the flexible elastomeric sleeve 40 to the end members 20 and 30 is achieved by way of mechanical fasteners, mechanical actions, such as crimping or clamping or by way of bonding or adhesives.

The novel arrangement or interlock uses air introduced under pressure into the hollow interior 12 to force each end of the flexible sleeve 40 into an abutting engagement with a respective end member 20 and or 30, wherein such abutting engagement is sufficient to form a seal and securely attach the end of the flexible sleeve 40 to the end members 20 and 30. In further reference to FIG. 1, such arrangement or interlock 50 includes a peripheral flange 52 upstanding on an interior surface of each end member 20, 30 in a direction generally perpendicular thereto. The cross-sectional shape of each peripheral flange 52 is provided in accordance with a cross-sectional shape of the flexible elastomeric sleeve 40, which is conventionally annular, but may be provided in any other shape. The peripheral flange 52 defines an interior surface 54, which is preferably is a generally planar surface. Preferably, the peripheral flange 52 has a uniform thickness throughout. The peripheral flange 52 may terminate the end member 20 or 30 or may be attached to such end member mediate ends thereof, for example such as by welding or casting method. Preferably, the thickness of the peripheral flange 52 is identical to the thickness of the respective end member 20 and 30 and, essentially, the peripheral flange 52 is integrated thereinto as a unitary one-piece construction.

A peripheral lip 60 is disposed generally coplanar with an interior or exterior surface of each peripheral flange 52 and is rigidly attached thereto. Preferably, the peripheral lip 52 is disposed on an interior surface 54 of the peripheral flange 52. The peripheral lip 60 has an outer edge 62 disposed in general alignment with a distal edge 56 of the peripheral flange 52 and has an inner edge 64 thereof facing in a direction toward the interior surface of each end member 20, 30. The instant invention allows a slight gap between the peripheral lip 60 and peripheral flange 52.

There is also a pair of peripheral flanges 70 and 80 being disposed on and rigidly attached to each end of the flexible elastomeric sleeve 40 in a spaced apart relationship with each other. The flanges 70 and 80 extend concentric with the longitudinal axis 12 and are preferably formed integral with the flexible elastomeric sleeve 40. It is not necessary in the instant invention for the peripheral flanges 70 and 80 to be identical to each other.

A peripheral abutment 72 is disposed on an inner one of the pair of peripheral flanges, referenced with numeral 70 in FIG. 1, in a direction toward an outer peripheral flange 80.

At least the peripheral lip 60 is positioned between the pair of peripheral flanges 70 and 80 with the inner edge 64 of the peripheral lip 60 abuttingly engages an inner edge 74 of the peripheral abutment 72. Furthermore, a surface 76 of the peripheral abutment 72 abuttingly engages the interior or exterior surface of the peripheral flange.

In operation, as further shown in FIG. 1, air 14 under pressure is introduced conventionally into the hollow interior 42 of the flexible elastomeric sleeve 40 through one of the end members 20 or 30 and forces one end member to move outwardly and axially, during inflation, away from another end member. Air 14 under pressure also forces the inner peripheral flange 70 in a direction towards at least the peripheral lip 60 for abutting engagement with an inner surface thereof and further forces the abutment 72 into abutting engagement with the inner edge 64 of the peripheral lip 60, thus attaching to and sealing the ends of the elastomeric sleeve 40 essentially with a respective end member 20, 30 in absence of mechanical fasteners, mechanical actions such as crimping, clamping or bonding or adhesives.

Thus, the peripheral lip 60, peripheral flanges 70 and 80, and the peripheral abutment 72 are so configured and sized that the end of the flexible elastomeric sleeve 40 is interlocked with the end members 20 and 30 assuring that structural and sealing integrity of the interlock 50 is maintained during inflation and deflation of the air spring 10. The instant invention also allows some air leakage though the interlock 50 consistent with any conventional air springs presently in use.

Now in a particular reference to FIG. 2, there is provided an arrangement or interlock, generally designated as 50', that includes the above described peripheral flange 52.

A peripheral abutment 90 is disposed at the distal end 56 of the peripheral flange 52. The peripheral abutment 90 includes an edge 92 tapering inwardly toward the interior surface 54 of the peripheral flange 52.

There pair of above described peripheral flanges 70 and 80 is also provided. The abutment 72 is provided with an edge 94 that has a taper complimentary to the taper of the edge 92. Now in a particular reference to FIG. 3, there is provided arrangement or interlock, generally designated as 50'', that also includes the above described peripheral flange 52.

The peripheral lip 60 is spaced apart from the interior surface 54 by a distance 96 sufficient to house an inturned flange 78 attached to the inner peripheral flange 70 of the flexible elastomeric sleeve 40. The surfaces of the inturned flange 78 may be disposed either in direct abutting engagements with respective surfaces of the peripheral flange 52 and peripheral lip 60 or in an arrangement wherein slight clearances between such mating surfaces are allowed.

It is contemplated by the instant invention that in the embodiment of FIG. 3, one peripheral flange, for example peripheral flange 80, may be omitted for a specific application, particularly of a light duty type.

It is to be understood that a combination of two embodiments of FIGS. 1-3 may be employed within the air spring 10, depending on a particular application.

A method of attaching and sealing ends of the flexible elastomeric sleeve 40 to a pair of end members 20, 30 in an air spring includes the step of providing a peripheral flange 52 on an interior surface of each end member 20, 30. Then, providing a first peripheral lip 60 or abutment 90 disposed on an interior surface of the peripheral flange 52 in general alignment with the distal edge 56 thereof. Next, providing a pair of peripheral flanges 70, 80 on each end of the flexible elastomeric sleeve 40 in a spaced apart relationship with each other. Providing a second peripheral lip 78 or abutment 72 on an inner one of the pair of peripheral flanges in a direction toward an outer one of the pair of peripheral flanges. And, finally, interlocking the first peripheral lip 60 or abutment 90 with at least the second peripheral lip 78 or abutment 72 in a manner not requiring mechanical fasteners, mechanical action or bonding or adhesives and in a manner substantially prohibiting passage of air therethrough.

Thus, in an air spring, the instant invention provides a novel arrangement or interlock that is configured to attach and seal ends of the flexible elastomeric sleeve 40 to the end members 20 and 30 in a manner not requiring mechanical fasteners, mechanical action or bonding or adhesives and in a manner substantially prohibiting passage of air through the interlock .

The above described embodiments are employable in an application taught in U.S. Pat. No. 7,931,130 issued to Ring on April 26, 2011 and owned by the assignee of the invention. Teachings of U.S. Pat. No. 7, 931, 130 are incorporated into this document by reference thereto.

Thus, the present invention has been described in such full, clear, concise and exact terms as to enable any person skilled in the art to which it pertains to make and use the same. It will be understood that variations, modifications, equivalents and substitutions for components of the specifically described embodiments of the invention may be made by those skilled in the art without departing from the spirit and scope of the invention as set forth in the appended claims.