MXPA98003033A - Clamp assembly for actuator of a - Google Patents

Abstract

The present invention relates to an air actuator which includes: a pair of end caps adapted to be mounted in generally axial locations, a flexible sleeve formed of an elastomeric material and having a pair of open ends coupled in a sealing manner with the caps at the end forming a fluid chamber therebetween; an axially extending annular sealing surface formed on at least one of the end caps, the sealing surface being formed with a pair of axially spaced annular projections extending radially outwardly; an annular clamp ring located concentrically with respect to the annular sealing surface of the end cap for securing one sealing end of the flexible sleeve therebetween, the clamp ring having a smooth continuous cylindrical inner surface terminating at a pair of edges of end, at least three grooves being formed on the sealing surface of the lid Extremely by the pair of annular projections to receive there elastomeric material of the arm, one of the slots being intermediate to the pair of projections with the other two slots being located on other sides of the projections, one of the projections is conical and the other of the projections have a rounded symmetrical configuration, and an annular shoulder extending radially outwardly formed at one end of the annular sealing surface of the end cap to confine the clamp ring to restrict movement of the clamp ring in the axial direction during operation of the actuator of ai

Description

CLAMP ASSEMBLY FOR AIR ACCIQNACOR AHTECEOJJECTS OF THE INVENTION Technical Field The invention relates to actuators of air and more particularly to fastening means adapted to fix a resilient elastomeric sleeve member with the relatively rigid end caps at each end of the actuator of air. Specifically, the invention relates to a clamp assembly for an air actuator and / or air spring and springs, which employ annular recesses or indentations in the end caps to form a series of clamping areas, with the intercalated sleeve that The sleeve is seated in a sealing way, when the clamp rings with smooth inner contact surfaces are folded over. Background Information Pneumatic structures such as actuators or air springs and springs have been used for many years for various purposes. The air actuator usually consists of a bellows or flexible rubber sleeve containing a supply of compressed air and a supply to increase or decrease the compressed fluid therein. The flexible sleeve is formed of a flexible elastomeric material that often contains reinforcing cords, wherein the flexibility of the material allows a first end cap to move axially relative to another end cap held within the ends of the sleeve as shown in FIG. amount of the compressed fluid is changed. Since the air actuator is positioned between a moving or actuating object and typically a fixed object, the moving object moves in corralation with this axial movement. As for the pneumatic dampers commonly referred to as air springs and springs, the construction is similar with a bellows or flexible rubber sleeve containing a supply of compressible fluid. However, the air spring and springs have one or more movable pistons with respect to the flexible sleeve. The piston causes compression and expansion of the fluid within the sleeve as the sleeve is stretched or retracted, respectively, thereby absorbing shock loads and / or damping vibrations. The flexible sleeve is formed of a flexible elastomeric material containing reinforcing cords and this allows the pist to move axially with respect to another piston or end cap held within the open ends of the sleeve. One application for air springs and springs is with motor vehicles, wherein the shock absorber provides cushioning between moving parts of the vehicle, primarily to absorb shock loads imparted to the vehicle's axles by wheels that strike an object on the road or fall into a depression. Whether in air actuators or air springs and springs, the ends of the sleeves connect sealingly the opposite end caps or the piston and the opposite end cap respectively and are always one of the important and main aspects to produce a shock absorber or maintenance-free and efficient air actuator. A problem with certain dampers or air actuators- and springs is the ineffective clamping and / or disconnection of the flexible sleeve to the end caps, resulting in the lack of an air-tight seal. Another problem with existing actuators and dampers and springs is that the cutter board exposed at the end of the elastomeric sleeve of the air spring and actuator and damper will engage the sleeve body as it is wound onto the piston or end cap under conditions of axial travel, causing excess wear to the flexible sleeve. Another problem with existing air springs and dampers and springs is the inability to clamp and hold the flexible sleeve to accept high pressures within the fluid pressure chamber within the flexible end-capped sleeve.

Another problem with existing air springs and dampers and springs is the inability to force or flow sufficient rubber from the sleeve into the slots in either or both of the clamping ring and the extra cover as it is stretched so that sufficient clamping occurs. by clamp. Another problem with existing actuators and dampers and springs is the failure of a component.The end-to-wall - the - sleeve between the clamp ring and the end cap is "faulty" and "an end cap or piston is typically the result when excessive pressure occurs and is less convenient against a side wall burst of the sleeve. Another problem with ... actuators and shock absorbers of existing air and springs is inefficiently held by the tightening areas that is, the forced iiule within the slots in either or both the clamp ring and the end cap, as required for a high pressure seal cash. Another problem with actuators and air springs and existing springs and in particular, the clamp ring therefore is that the clamp ring will move in its clamped position under dynamic conditions, causing movement of the material elastomeric clamped between them, tending to loosen the sealing and deterioration of the integrity of the clamp and causing failure and final leakage. This ring movement is especially critical during the rebound or the crush stroke. Another problem with existing actions and shock absorbers and springs and the clamping of the ends of the alastomeric sleeve to the piston member and / or end cap, consists of holding a sufficiently tight seal to be able to withstand high fluid pressures contained in the fluid chamber without premature leakage or bursting, even when experiencing severe movement of the air damper and springs and exposing to rough environments in the lower part of the vehicle. Another problem with existing air springs and dampers and springs and the clamping of the eiastomeric sleeve ends to the piston member and / or end caps is the time-consuming, labor-intensive and costly process of creating grooves. / indentations and / or projections both on the outer diameter of the end caps and / or pistons, and the clamp rings to ensure that the flexible rubber sleeve does not slide out between the end caps and / or piston and the ring. Some examples of actuators and air springs and springs and their end seal devices are illustrated in the following patents described below. The patent of the U.S.A. No. 3,788,628 discloses a system of spring type or pneumatic damper, which includes a structure for anchoring the inner ends of a flexible winding sleeve. The sleeve is placed between surfaces characterized by having a serrated shape with a circumferential groove and rib on an inner circumferential surface and two ribs on an outer circumferential surface. Opposite sides of the grooves converge at predefined angles with predetermined and corresponding radius of curvature, the combination giving a clamping action for holding the flexible sleeve firmly in place, by means of sawtooth design in cooperation with the recess corresponding to the sleeve and ring flange. The patent of the U.S.A. No. 3,870,286, refers to a fluid or hydraulic damper, wherein the ends of the roller sleeve are held by annular clamping rings which engage against the inner surface of the sleeve. The clamp ring secures the winding sleeve to the operating cylinder with the clamp ring containing the annular groove type deformation by which the winding sleeve is held in place, by virtue of this interacting groove shape design in combination with the force of clamp exerted by the ring. - The patent gives the US. No. 4,489,474, relates to means for connecting a flexible tubular member to a piston that includes a recess near the piston end that is secured to a flexible member. The flexible member is wrapped over and around a ring-shaped fixture that holds the flexible member to the piston. The ... piston ... comprises a base extending circumferentially adjacent its end with the flexible sleeve positioned and substantially filling the recess of the piston. The ring-shaped fixture is a conventional crimped or compressed ring and the end portion of the flexible member is cut away from the portion extending from the piston ring with the flexible member that substantially fills the recess of the piston shoulder. The piston employs a serrated edge to assist in holding the flexible member. The patent of the U.S.A. No. 4, 457,692, discloses a structure for sealing two members, one of which has a cylindrical surface bearing the seal, wherein a seal lip is provided to lean against the second member. A cylindrical surface supports the seal comprising a hollow cylindrical body having a lip extending outwardly from the body with an elastomeric band that encircles the body to hold it firmly in place. The cylindrical surface contains a recess extending circumferentially around the surface and receiving a projection member coupled to the seal extending from the inside diameter of the cylindrical body. The patent of ios E.U.A. No. 4,573,692, discloses a structure for sealing two members, one of which has a cylindrical surface bearing the seal, wherein a seal lip is provided to lean against the second member. A cylindrical surface supports the seal comprising a hollow cylindrical body having a lip, which extends outwardly from the body with an elastomeric band qua encircling the body to hold it firmly in place. The cylindrical surface contains a recess extending circumferentially around the surface and receiving a corresponding projecting member of the seal extending from the inside diameter of the cylindrical body. The patent of the? .U.A. No. 4,629,170, relates to a pneumatic damper with a pair of chambers formed by a pair of membranes that are sealingly connected with an axially spaced piston and retainer, wherein the axial end of the membrane is compressed between a surface with a serrated saw. solid member and a retaining ring wherein the ring may be compressed, adapted or otherwise squeezed to produce radial compression against the axial ends of the flexible membranes. British patent 199,789 discloses a metal fastening band that holds a diaphragm and forces it against a tapered end portion of a tubular member. The patent of the U.S.A. No. 4,718,650, shows an air damper and springs wherein the ends of the flexible sleeves are connected to the sealing surfaces of a pair of pistons axially spaced by folded and compressed clamping rings. Piston clamp surfaces are formed with saws to help retain the elastomeric material when they are forced there by the clamp rings. Some of the problems discussed above are resolved by the clamp structure illustrated in the .U.A patents. Nos. 4,399,995 and 4,852,361. These patents show the use of a clamp ring, which has a centrally located, simple recess, which aligns with an outwardly extending projection formed on the seal surface of the piston and end member in order to place the clamp ring in the end member or piston. A pair of compression areas are formed on opposite sides of the precession by surfaces or annular rings extending outwardly on the seal surfaces of the piston and / or end member. These rings form the tightening areas or zones in cooperation with the inner annular surface extending axially of the clamp ring, on opposite sides of the concave recess. Although this clamp ring structure, solves some of the problems discussed above and is extremely efficient for many applications, especially for air springs and larger springs that have high internal pressure, it can provide all the desirable characteristics required by the industry, including clamp power, airtight seal and economical production required. A disadvantage of the clamp structure illustrated in these two patents is that the clamp rings require a more complicated configuration and in particular a recess formed in the center of the inner surface of the ring. This requires that a more expensive ring be used in the air damper and springs. It is much more economical to use a clamp ring in which the inner cylindrical surface is a continuously smooth surface free of recesses, however, achieves the desired clamping force. SUMMARY OF THE INVENTION Objects of the invention include providing an improved end cap structure for air actuators having axially spaced end caps, at opposite ends with a flexible elasto sleeve projecting therein and subjecting them to the caps respective end by a clamp ring to form a fluid tight seal therebetween and provide an intermediate pressurized chamber. A further object of the invention is to provide this end cap structure where the movement of the clamp ring is reduced when operating under dynamic conditions by placing the ring directly against an annular flange of the end cap .. maintaining this a positive seal effect with the elastomeric sleeve held by clamp between the ring and a seal surface of the end cap. A further object of the invention is to provide this improved end cap structure wherein the end cap clamp surface includes concave annular grooves or females separated by projections, to facilitate efficient clamping of the elastomeric material therebetween and to alter the direction of the reinforcing cords contained within the elastomeric sleeve to further increase the clamping effect of the ring, and this construction locates positionally the clamping ring on the seal surface of the end cap. A further object of the invention is to provide an improved end cap structure in which a clamp ring is compressed to facilitate efficient clamping of the elastomeric material between the seal surface in the end cap and the clamp ring. A further object of the invention is to provide an improved air and spring damper and actuator, which is designed to gravitate towards a side wall burst instead of a seal failure or end component when excessive pressure occurs within the chamber. fluid pressure. A further object of the invention is to provide this improved end cap structure wherein annular expansion grooves are formed between annular projections on the end cap seal surfaces to allow the elastomeric material to flow. A further object of the invention is to provide a greater and deeper rubber flow within the grooves in the seal surface in the end cap, thereby providing improved clamp and seal characteristics.

A further object of the invention is to provide annular grooves designed to receive and maintain the sleeve better than the designs of the prior art. A further object of the invention is to provide specific slot configurations including at least one radially designed slot that is preferably larger than the prior art designs. A further object of the invention is to provide three different annular grooves with different configurations and / or dimensions to provide improved clamp. A further principal object of the invention is to provide a clamp ring having an internal, smooth, continuous cylindrical surface, which provides clamping rings less costly than those employed up to the arrow with recesses or shaped interior surfaces. BRIEF DESCRIPTION OF THE DRAWINGS A preferred embodiment of the invention, illustrative of the best mode in which applicants have contemplated applying the principles, is set forth in the following description and is illustrated in the drawings and is particularly and distinctly stated in the appended claims. Figure 1 is an elevation view of the improved end cap structure which is incorporated in an air actuator with cut-out and sectioned portions. Figure 2 is an enlarged perspective view of the clamp ring; and Figure 3 is a highly amplified fragmentary sectional view showing a clamp ring that holds one end of the elastomeric sleeve against the seal surface of the improved end cap. Similar numbers refer to similar parts through the drawings. i DESCRIPTION D? PREFERRED QUALITY The improved end cap structure of the invention is illustrated mounted on an air actuator generally indicated at 10 in Figure 1. The air actuator 10 includes axially spaced end members consisting of two improved end caps. indicated generally with 11 and 12, respectively. A flexible sleeve 13 of elastomeric material having internal reinforcing cords sa extends between the end caps 11 and 12 which are clamped within the open ends of the sleeve 13, by clamp rings 14. Once fully assembled, the sleeve 13 and the extramo lids II and 12 form an internal fluid pressure chamber 15, which is pressurized with a compressed fluid by a fluid feed 40, so that increasing or decreasing the compressed fluid causes an increase or decrement in the distance between the end caps 11 and 12 to drive one or more of the devices there connected. The end caps 11 and 12 are of a substantially identical configuration except that one or more of the end caps, in this embodiment the end cap 12, may include a threaded shaft 20 axially extending therefrom and some form of feed. 40. Due to this similarity in construction, the following description of the end cap 12 will be equally applicable to the end stage 11. The end cap 12 includes an enlarged head 21, a base 23 and a neck 22 therebetween . The enlarged head 21 is of a substantially flat planar flange and of a larger diameter than the neck 22 to the base 23. The enlarged head extension 21 outside the neck 22 defines an annular shoulder 24 against which the clamp ring rests. 14. The enlarged head is also a substantial planar flange with a rounded outer annular surface 25.

The neck 22 extends from the innermost point of the shoulder 24 to the base 23. - The annular outer surface of the neck 22 includes a plurality of annular grooves with a pair of annular projections extending therefrom. Specifically, the neck 22 includes a large annular groove 30, an annular groove of conical shape 31 and a small annular groove 32. Each of these grooves extends inward from the annular-outer surface of the neck 22., as illustrated more clearly in Figure 3. A conical projection 33, projects annularly outwardly into the neck 22 between the slots 30 and 31, while a rounded symmetrical projection 34, extends anuously outwardly between the slots. 31 and 32. In a more preferred embodiment as illustrated in Figures 1-3, the large annular groove 30 is an annular indentation in the neck 22 of a U-shaped cross section, wherein the cross section is taken radially. Similarly, the small annular groove 32 is an annular indentation in the neck 22 of a U-shaped cross section with a rounded base when the cross section is taken radially. The only difference between the slots 30 and 32 is that the slot 32 is of a smaller diameter. In each of these grooves, the depth of the groove is preferably greater than the width. As for the conical annular groove, this groove 31 is an annular indentation in the neck 22 and a V-shaped cross-section, when the cross-section is taken radially when one side of the IVIV "is perpendicular to the central axis of the structure. 10 while the other side of the "V" is at an angle with respect to the central axis, preferably, this angle is approximately 15 ° from the first side "of the" "V" that is perpendicular to the cintra axis! 23 extends from the neck 22 in a radially outward manner to define a lip 35. From the lip 35, the base 23 tapers axially inward on the tapered surface 36 to the bottom 37. In a more preferred embodiment, this taper is about 35 ° As illustrated in Figure 1, the end cap 12 further includes the threaded shaft 20, which extends axially away from the enlarged head 21 opposite the neck 22. A fluid supply 40 extends axially through s of the end cap 12 from the bottom 37, almost to the end of the threaded shaft 20, where the fluid supply 40 ends in a threaded bore 41. In contrast, the end cap 12 does not include a fluid supply but it includes a threaded bore 42. The threaded positions 41 and 42 are used to connect their respective end caps with objects that will move in correlation with changes in fluid pressure. In addition, the threaded bore 41 also supplies a fluid communication gate to the fluid feed 40. Each of the end caps II and 12 are preferably formed of a high strength glass reinforced plastic material. In addition, one of the end caps can be provided with a solenoid control valve for regulating the fluid pressure inside the air actuator, preferably on the fluid supply 40. The flexible sleeve 13 has a generally cylindrical configuration and is formed It gives a material elasto érico that generally contains the internal reinforcing cords that are trapped inside one or more batteries of an erysto ero. The elastomeric material is of sufficient flexibility, so that the flexible sleeve 13 can be wound around the clamp rings 14 and over the enlarged heads 21, during the low levels of compressed fluid, where the objects connected to the caps of end move in closer proximity to each other. It is for this reason that the clamp rings 14 and the end caps 11 and 12, particularly on the enlarged heads 21, have rounded surfaces so as not to tighten or tear the elastomeric material of the flexible sleeve 13. The clamp rings 14 are continuous rings , preferably made of metal such as aluminum with corners or rounded edges. According to one of the features of the invention, each clamp ring 14 will have a continuous cylindrical interior surface __16 that joins with a smooth continuous cylindrical-outer surface 18 by somewhat rounded edges or ends., usually smooth 19 and 19a. When assembled, each end of the flexible sleeve 13 is fastened substantially in a generally air-tight relationship, against the neck surface 22 by the smooth inner surface 16 of the seal ring 14, which is then compressed or otherwise compressed and folds to seal the sleeve end against the neck surface 22. The result of this compression is the force of the rubber sleeve 13 within the grooves 30-32, to fully fill the grooves and compress the sleeve 13 between the inner surface 18 of the clamp ring 14 and the end cap 11 and 12. The bands within the sleeve 13 are deformed and contoured by the slots 30-32. As a result, rubber sleeve knots are formed with deformed bands in the grooves 30-32 which act to prevent the rubber from pulling out of the grooves. This is accentuated particularly in the larger slot 30. In effect, the compressed ring provides an air tight seal that is maintained even during a sleeve break or other failure that will only occur in the side wall instead of the connection due to this improved design. The compressed design also allows higher pressures to be maintained within the chamber 15 than those that are. ^ .alcanz.aron .previously with the designs of the prior art. that did not have the "clamp ring" compressed around the three slotted end caps In use, the end 19 of the clamp ring 14 rests between the shoulder 24 and the combination of the lip 35 and the inflated flexible sleeve 13, as clearly illustrated in Figure 3. In this way, the clamp rings 14 can not be removed without releasing pressure inside the fluid pressure chamber 15, such that the flexible sleeve 13 deflates and rests against or approximate the tapered surface 36, so that the clamp rings 14 can be withdrawn axially inwardly on the base 23 spaced apart from the neck 22 in each extra cover.Thus, the ends of the flexible sleeve 13 are tightened between the smooth inner surface 1S of the clamp ring 14 and the neck 22 in an air-tight manner.Therefore, changes in fluid pressure within the chamber 15 by the increase or decrease in the fluid compressed, they cause the end caps 11 and 12 to move axially closer or closer to each other, respectively. This axial movement allows the movement of any objects connected to the end cap simply by increasing or decreasing the compressed fluid within the chamber 15 by the fluid supply 40. In this way, the air actuator 10 functions to control the space between objects connected to the extramo lid. Although the above description fully illustrates an air actuator, it is readily understood that the term "air actuator" includes air dampers and springs or similar pneumatic components. Accordingly, the improved clamp ring structure is simplified, provides an effective, safe, economical and efficient device that achieves all the objectives listed, allows to eliminate the difficulties encountered with previous devices and solves problems and obtain new results in the technique . In the previous description, certain terms have been used for brevity, clarity and understanding; but no unnecessary limitations shall be implied to them beyond the requirement of the prior art, because these terms are used for descriptive purposes and therefore are widely considered. Still further, the description and illustration of the invention is by way of example, and the scope of the invention is not limited to the exact details illustrated or described. - - - - Having now described the features, discoveries and principles of the invention, the manner in which the clamp ring structure is constructed and used, the characteristics of the construction and the advantages and the new and useful advantageous results obtained; the new and useful structures, devices, elements, assemblies, parts and combinations are set forth in the appended claims.

Claims (3)

1. CLAIMS 1. An air actuator for positioning between a pair of moving objects together, characterized in that it comprises: a pair of axially spaced end caps, each end cap having a sleeve receiving outer surface, including a plurality of annular grooves and wherein at least one of the end caps includes a through fluid; a flexible sleeve having a pair of axially spaced open ends, each received by one of the outer sleeve receiving surfaces in one of the end caps, thereby defining a fluid pressure chamber therein; and a pair of clamp rings, each having a smooth inner clamp surface to hold the flexible sleeve against one of the outer sleeve receiving surfaces.
2. 2. The air actuator according to claim 1, characterized in that each end cap includes an enlarged radial head that extends beyond and adjacent to the outer receiving surface of the sleeve.
3. 3. The air actuator according to claim 1, characterized in that each end cap includes a base tapering radially in and away from the outer receiving surface of the sleeve. 4-. The air actuator according to claim 1, characterized in that each outer receiving surface of the sleeve comprises a neck extending from an enlarged head to a lip, each of which extends radially outward more than the neck to define a channel in which the clamp ring sits. The air actuator according to claim 4, characterized in that the flexible sleeve is displaced and tightened or pinned within the slots, when each clamp ring is placed around the sleeve on the neck and is folded inwardly. or The air actuator according to claim 1, characterized in that the plurality of annular grooves includes a large U-shaped annular groove, a small U-shaped ring groove and an annular groove conically shaped therebetween. 7. The air actuator according to claim 6, characterized in that each of the slots includes an outermost annular surface, an innermost annular surface and a curved base between them. The air actuator according to claim 7, characterized in that the outermost and innermost surfaces of each of the U-shaped grooves are in parallel planes. 9. The air actuator according to claim 7, characterized in that the outer and inner surfaces of the conical groove are in oblique planes. The air actuator according to claim 9, characterized in that the oblique planes are approximately 15 J out of parallelism. The air actuator according to claim 7, characterized in that the large U-shaped groove is the outermost groove. The air actuator according to claim 5, characterized in that the inward folding of the clamp ring around the sleeve on the neck is a compressed connection. The air actuator according to claim 1, characterized in that the fluid passing through is closed after initial prasurization of the fluid pressure chamber, resulting in the air actuator functioning as an air damper and springs. 14. An air actuator that is positioned between a pair of moving objects together, characterized in that it comprises: a pair of axially spaced end members, at least one of the end members has a sleeve receiving outer surface that includes a groove outermost annular, an innermost annular groove and an annular groove intermediate therebetween, wherein the outermost grooves of the first end member are further apart than the innermost grooves and wherein the configuration of each of the outermost grooves, intermediate and more internal is different; a flexible sleeve having a pair of axially spaced ends, at least one of which is open and is received by the outer receiving surfaces of the end member, thereby defining a fluid precession chamber between the members of the end member. end, and a clamp annulus having a smooth internal clamp surface for holding the flexible sleeve against the outer sleeve receiving surface 15. The air actuator according to claim 14, characterized in that the outermost annular groove in the annular groove. end member is an annular cut within the end member having a depth greater than its thickness and having a rounded base 16. The air actuator according to claim 15, characterized in that the innermost annular groove in the member end is an annular cut within the end member that has a depth substantially greater than its thickness when or the depth is substantially equivalent to the depth of the outermost annular groove and having a rounded base. 17. The air actuator according to claim 14, characterized in that the inter-annular groove in the extramo member is an annular cut within the end member having a varying thickness over its depth. X 18. An end cap for "use with an air actuator that is placed between a pair of mobile objects relative to each other, characterized in that it comprises: a neck having a more external and more internal end and including an outer peripheral surface with an outermost annular r-an, an innermost annular groove and an annular groove intarmediate between them, wherein the outermost grooves of the pair of endcaps are separated more than the internal grooves and when the configuration of each of the more external intermediate and innermost grooves is different: an enlarged head of a flat disc shape with upper and lower surface having an outer edge rounded therebetween, the enlarged head integrally connected to the outermost end of the neck and extending radially outwardly beyond the neck, and a base integrally connected to the innermost end of the neck and having a lip adjacent to and extending slightly dial outward beyond the neck. An end cap according to claim 18, characterized in that the outermost annular groove in each end cap is an annular cut within the end cap having a rounded base and a depth greater than its thickness, the groove innermost annular in each end cap is an annular cut within the end layer having a rounded base and a depth substantially greater than its thickness when the depth is substantially equivalent to the depth of the outermost annular groove, which has a rounded base, and the intermediate annular groove in each end cap is an annular cut inside the end cap having a rounded base and varying thickness over its depth.