Equalizer for a suspension system

An equalizer for a suspension system for a trailer is configured to absorb or dampen the harsh shocks or vibrations coming off of the leaf springs proximate to a center frame hangar, thus allowing for a “softer” ride. The equalizer utilizes two independent equalizer arm assemblies which are each rotatably secured within the equalizer. Each equalizer arm assembly is operatively associated with one of the front or rear leaf springs such that upon upward movement of either the front or rear leaf spring, the associated equalizer arm assembly is forced to rotate within the equalizer and to deform a shock absorber provided within the equalizer. The shock absorber, upon the deformation thereof, absorbs the harsh shocks or vibrations which would otherwise normally be transferred from the leaf springs, to the equalizer, and thus to the frame of the trailer.

BACKGROUND OF THE INVENTION

The invention is generally directed to an equalizer for a suspension system used in vehicles or trailers having tandem axles generally between 2,000 pounds and 7,000 pounds with double eye springs, such as recreational vehicles, mobile homes and light trailers of all types.

A prior art suspension system20currently used on trailers incorporates an equalizer22such as the one shown inFIG. 1. The suspension system20is mounted on a frame24of the left side of the trailer and another, identical suspension system20is mounted on the frame24of the right side of the trailer. Only the suspension system20mounted on the frame24of the left side of the trailer is shown inFIG. 1. The suspension system20includes the equalizer22, a front leaf spring26, a rear leaf spring28, a front shackle or link30and a rear shackle or link32.

The equalizer22is generally triangular in shape, having a first end corner34, a second end corner36and a third end corner38. Other equalizers of the prior art may be curved rather than triangular in shape. The equalizer22is generally formed of cast iron and is rigid. The first end corner34of the equalizer22is attached to a center frame hangar40, which depends from the frame24of the trailer, at a point A. The second end corner36of the equalizer22is pivotally mounted to a first end42of the front shackle30at a point B. The third end corner38of the equalizer22is pivotally mounted to a first end44of the rear shackle32at a point C.

A second end46of the front shackle30is pivotally mounted to a rear end48of the front leaf spring26at a point D. A front end50of the front leaf spring26is attached to the frame24of the trailer at a point E.

A second end52of the rear shackle32is pivotally mounted to a front end54of the rear leaf spring28at a point F. A rear end56of the rear leaf spring28is attached to the frame24of the trailer at a point G.

A front axle58is positioned on the forward leaf spring26generally equidistantly between point D and point E. A rear axle60is positioned on the rear leaf spring28generally equidistantly between point F and point G.

To the extent possible, road shock and vibrations from tires of the trailer are transferred to the front and rear axles58,60, and are absorbed by the front and rear leaf springs26,28, respectively. Points A, E and G are the contact points through which the road shock is passed to the frame24. The equalizer22basically has only one purpose for being including in the suspension system20, which is to equalize the weight on both the front and rear axles58,60as the tires pass over uneven terrain. For example, an upward motion of the front leaf spring26results in a downward motion of the rear leaf spring28.

The equalizer22, however, is not configured to dampen or absorb the harsh shocks or vibrations coming off the rear end48of the front leaf spring26and the front end54of the rear leaf spring28proximate to the center frame hangar40, which would thus allow for a “softer” ride. The equalizer22of the prior art has been in use without a single design change for at least the past forty (40) years.

Thus, there is a need for an equalizer which overcomes the aforementioned disadvantages. The present invention provides such an equalizer. Features and advantages of the present invention will become apparent upon a reading of the attached specification, in combination with a study of the drawings.

SUMMARY OF THE INVENTION

Briefly, and in accordance with the foregoing, the invention provides an equalizer for a suspension system for a trailer or the like which is configured to equalize the weight on both the front and rear axles of a trailer as tires of the trailer pass over uneven terrain, but which also is configured to dampen or absorb the harsh shocks or vibrations coming off of the rear end of a front leaf spring and the front end of a rear leaf spring proximate to a center frame hangar, thus allowing for a “softer” ride. The equalizer utilizes two independent equalizer arm assemblies which are each rotatably secured within the equalizer. Each equalizer arm assembly is operatively associated with one of the front or rear leaf springs such that upon upward movement of either the front or rear leaf spring, the associated equalizer arm assembly is forced to rotate within the equalizer and to deform a shock absorber provided within the equalizer. The shock absorber, upon the deformation thereof, absorbs the harsh shocks or vibrations which would otherwise normally be transferred from the leaf springs, to the equalizer, and thus to the frame of the trailer.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT

While this invention may be susceptible to embodiment in different forms, there is shown in the drawings and will be described herein in detail, a specific embodiment with the understanding that the present disclosure is to be considered an exemplification of the principles of the invention, and is not intended to limit the invention to that as illustrated.

It is to be understood that where dimensions are used in the description of the illustrated embodiment, these dimensions are those for the preferred embodiment of the illustrated embodiment. It is to be further understood that modifications to the dimensions may be made in keeping with the spirit of the invention, and that the dimensions are not intended to limit the invention to those dimensions described. Also, it is also to be understood that the drawings may not be drawn to scale in conformance with the dimensions described herein.

An equalizer100is provided for use in a suspension system102, as illustrated inFIG. 2, to equalize the weight on both the front and rear axles418,420as the tires pass over uneven terrain (as does the equalizer22of the prior art suspension system20), as well as to dampen or absorb the harsh shocks or vibrations coming off the rear end408of the front leaf spring394and the front end414of the rear leaf spring396proximate to the center frame hangar372, thus allowing for a “softer” ride. As best illustrated inFIGS. 32-36, the equalizer100includes first and second base plates104a,104b, first and second secondary base plates106a,106b, first and second equalizer arms108a,108b, first and second lower shock plates110a,110b, first and second upper shock plates112a,112b, a reinforcement plate114, first and second shock absorbers116a,116b, first, second, third and fourth upper pivot tubes119a,119b,119c,119d, first and second lower pivot tubes120a,102b, first, second and third fastening members122a,122b,122c, first, second and third securing members124a,124b,124c, and a base or shock spacer126.

FIGS. 3 and 4illustrate the first base plate104a, which is preferably formed of a forged, cast or fabricated metal. The first base plate104ais identical in shape and configuration to the second base plate104b. As such, only the first base plate104ais described with the understanding that the description of the second base plate104bwould be identical. The elements of the first base plate104awill have reference numerals ending in “a”. As such, it is to be understood that the elements of the second base plate104bwill have like reference numerals ending in “b”.

The configuration of first base plate104ais defined with reference to a horizontal reference line X and a vertical center reference line Y, provided inFIG. 4. The first base plate104ais a generally triangular thin plate having first and second side surfaces129a,131aseparated by an edge described herein.

A top128aof the first base plate104ais provided at the intersection of the horizontal reference line X and the vertical center reference line Y. A bottom130aof the first base plate104ais provided at a predetermined distance below the top128a, for example 7.688 inches below. A first reference point A is provided at a predetermined distance below the top128a, for example 1.125 inches below, along the reference line Y. A second reference point B is provided at a predetermined distance below the top128a, for example 2.250 inches below, along the reference line Y, and is spaced apart from and below reference point A. A third reference point C is provided at a predetermined distance below the top128a, for example 3.875 inches below, along the reference line Y, and is spaced apart from and below reference point B. A fourth reference point D is provided at a predetermined distance below the reference line X, for example 3.604 inches below, and at a predetermined distance to the left of reference line Y, for example 1.797 inches to the left. A fifth reference point E is provided at a predetermined distance below the reference line X, for example 4.104 inches below, and at a predetermined distance to the left of reference line Y, for example 3.172 inches to the left, and falls outside of the physical surface of the first base plate104a. A sixth reference point F is provided at a predetermined distance below the reference line X, for example 5.409 inches below, and at a predetermined distance to the left of reference line Y, for example 2.387 inches to the left. A seventh reference point G is provided at a predetermined distance below the reference line X, for example 6.438 inches below, and at a predetermined distance to the left of reference line Y, for example 0.563 inches to the left. An eighth reference point H is provided at a predetermined distance below the reference line X, for example approximately 1.75 inches below, and at a predetermined distance to the left of reference line Y, for example approximately 0.625 inches to the left. Reference points E is provided outside of the perimeter of the first base plate104a, whereas reference points A, B, C, D, F, G, H are provided inside of the perimeter of the first base plate104a.

The left side of the first base plate104a(everything to the left of the reference line Y as viewed inFIG. 3) is described, with the understanding that the right side of the first base plate104a(everything to the right of the reference line Y as viewed inFIG. 3) is the mirror image. As such, the edges, apertures and reference points on the right side are not described and are denoted with a prime.

From the top128a, a first edge portion132ais formed as an arc about reference point A at a predetermined radius, for example at a radius of 1.125 inches. Thus, the first edge portion132acurves downwardly and to the left of reference line Y. A third edge portion136ais formed as an arc about reference point D at a predetermined radius, for example at a radius of 0.687 inches. A second edge portion134ais formed as a line which is tangent to both the first edge portion132aand the third edge portion136a. Thus, the second edge portion134aextends downwardly and to the left from the first edge portion132ato the third edge portion136a, and the third edge portion136acurves downwardly and to the left from the second edge portion134a. A fifth edge portion140ais formed as an arc about reference point E at a predetermined radius, for example at a radius of 0.688 inches. A fourth edge portion138ais formed as a line which is tangent to both the third edge portion136aand the fifth edge portion140a. Thus, the fourth edge portion138aextends downwardly and to the left from the third edge portion136ato the fifth edge portion140a, and the fifth edge portion140acurves downwardly and to the left from the fourth edge portion138a. A seventh edge portion144ais formed as an arc about reference point F at a predetermined radius, for example at a radius of 0.687 inches. A sixth edge portion142ais formed as a line which is tangent to both the fifth edge portion140aand the seventh edge portion144a. Thus, the sixth edge portion142aextends downwardly and to the left from the fifth edge portion140ato the seventh edge portion144a, and the seventh edge portion144acurves downwardly and to the left from the sixth edge portion142ato a left end146a, which is the furthermost left point along the perimeter of the first base plate104afrom reference line Y, and further curves downwardly and to the right from the left end146a. A ninth edge portion150ais formed as an arc about reference point G at a predetermined radius, for example at a radius of 1.250 inches. An eighth edge portion148ais formed as a line which is tangent to both the seventh edge portion144aand the ninth edge portion150a. Thus, the eighth edge portion148aextends downwardly and to the right from the seventh edge portion144ato the ninth edge portion150a, and the ninth edge portion150acurves downwardly and to the right from the eighth edge portion148a. A tenth edge portion152ais formed as a line which is tangent to the ninth edge portion150aand which is parallel to the reference line X. Thus, the tenth edge portion152aextends straight to the right from the ninth edge portion150ato the bottom130a.

A first aperture180ais formed through the first base portion104aand extends from the first surface129ato the second surface131a. The first aperture180ais generally shaped like an hourglass and includes a first section182a, a second section184a, and a third connecting section186awhich connects the first section182ato the second section184a. The first, second and third sections182a,184a,186aare all illustrated as being bisected by the reference line Y such that half of the first, second and third sections182a,184a,186aare provided on the left side of the first base portion104aand such that the other half of the first, second and third sections182a,184a,186aare provided on the right side of the first base portion104a.

The first portion182ais formed by a circle with a predetermined radius defined about reference point A, for example a radius of 1.125 inches. The second portion184ais formed by a circle with a predetermined radius defined about reference point B, for example a radius of 1.125 inches. The circles defining the first and second portions182a,184aare tangential to one another at a point which is on the same horizontal plane as reference points H and H′. The connecting portion186ais defined by edges of the first aperture180aformed at a predetermined radius about reference points H and H′, respectively, for example at a radius of 0.375 inches, such that the first aperture180ais relatively hourglass shaped.

A second aperture188ais formed through the first base portion104aand extends from the first surface129ato the second surface131a. The second aperture188ais formed by a circle with a predetermined radius defined about reference point C, for example with a radius of 0.29 inches. The second aperture188ais illustrated as being bisected by the reference line Y such that half of the second aperture188ais provided on the left side of the first base portion104aand such that the other half of the second aperture188ais provided on the right side of the first base portion104a.

A third aperture190ais formed through the first base portion104aand extends from the first surface129ato the second surface131a. The third aperture190ais formed by a circle with a predetermined radius defined about reference point G, for example with a radius of 0.29 inches.

A fourth aperture190a′ is formed through the first base plate104aand extends from the first surface129ato the second surface131a. The fourth aperture190a′ is formed on the right side of the first base plate104aand is the mirror image of the third aperture190a, which is formed on the left side of the first base plate104a.

FIGS. 5 and 6illustrate the first secondary base plate106a, which is preferably formed of a forged, cast or fabricated metal. The first secondary base plate106ais identical in shape and configuration to the second secondary base plate106b. As such, only the first secondary base plate106ais described with the understanding that the description of the second secondary base plate106awould be identical. The elements of the first secondary base plate106awill have reference numerals ending in “a”. As such, it is to be understood that the elements of the second base plate106bwill have like reference numerals ending in The configuration of the first secondary base plate106ais defined with reference to a horizontal reference line X and a vertical center reference line Y, provided inFIG. 6. The first secondary base plate106ais a generally triangular thin plate having first and second side surfaces195a,197aseparated by an edge described herein.

A top194aof the secondary base plate106ais provided at the intersection of the horizontal reference line X and the vertical center reference line Y. A bottom196aof the secondary base plate106ais provided at a predetermined distance below the top194a, for example 3.75 inches below. A first reference point A is provided at a predetermined distance below the top194a, for example 0.563 inches, along the reference line Y. A second reference point B is provided at a predetermined distance below the reference line X, for example 2.169 inches below, and at a predetermined distance to the left of reference Y, for example 0.281 inches. A third reference point C is provided at a predetermined distance below the reference line X, for example 3.125 inches below, and at a predetermined distance to the left of reference Y, for example 0.563 inches. Reference points A, B and C are all provided inside the perimeter of the first secondary base plate106a.

The left side of the first secondary base plate106a(everything to the left of the reference line Y as viewed inFIG. 6) is described, with the understanding that the right side of the first secondary base plate106a(everything to the right of the reference line Y as viewed inFIG. 6) is the mirror image. As such, the edges, apertures and reference points on the right side are not described and are denoted with a prime.

From the top194a, a first edge portion198ais formed as an arc about reference point A at a predetermined radius, for example at a radius of 0.562 inches. Thus, the first edge portion198acurves downwardly and to the left of reference line Y. A third edge portion202ais formed as an arc about reference point B at a predetermined radius, for example at a radius of 1.5 inches. A second edge portion200ais formed as a line which is tangent to both the first edge portion198aand the third edge portion202a. Thus, the second edge portion200aextends downwardly and to the left from the first edge portion198ato the third edge portion202a, and the third edge portion202acurves downwardly and to the left from the second edge portion200ato a left end204a, which is the furthermost left point along the perimeter of the first secondary base plate106afrom reference line Y, and further curves downwardly and to the right from the left end204a. A fifth edge portion208ais formed as an arc about reference point C at a predetermined radius, for example at a radius of 0.625 inches. A fourth edge portion206ais formed as a line which is tangent to both the third edge portion202aand the fifth edge portion208a. Thus, the fourth edge portion206aextends downwardly and to the right from the third edge portion202ato the fifth edge portion208a, and the fifth edge portion208acurves downwardly and to the right from the fourth edge portion206a. A sixth edge portion210ais formed as a line which is tangent to the fifth edge portion208aand which is parallel to the reference line X. Thus, the sixth edge portion210aextends straight to the right from the fifth edge portion208ato the bottom196a.

A first aperture230ais formed through the first secondary base plate106aand extends from the first surface195ato the second surface197a. The first aperture230ais formed by a circle with a predetermined radius defined about reference point A, for example with a radius of 0.29 inches. The first aperture230ais illustrated as being bisected by the reference line Y such that half of the first aperture230ais provided on the left side of the first secondary base plate106aand such that the other half of the first aperture230ais provided on the right side of the first secondary base plate106a.

A second aperture232ais formed through the first secondary base plate106aand extends from the first surface195ato the second surface197a. The second aperture232ais formed by a circle with a predetermined radius defined about reference point C, for example with a radius of 0.29 inches.

A third aperture232a′ is formed through the first secondary base plate106aand extends from the first surface195ato the second surface197a. The third aperture232a′ is formed on the right side of the first secondary base plate106aand is the mirror image of the second aperture232a, which is formed on the left side of the first secondary base plate106a.

FIGS. 7 and 8illustrate the first equalizer arm108a, which is preferably formed of a forged, cast or fabricated metal. The first equalizer arm108ais identical in shape and configuration to the second equalizer arm108b. As such, only the first equalizer arm108ais described with the understanding that the description of the second equalizer arm108bwould be identical. The elements of the first equalizer arm108awill have reference numerals ending in “a”. As such, it is to be understood that the elements of the second equalizer arm108bwill have like reference numerals ending in “b”.

The configuration of the first equalizer arm108ais defined with reference to a horizontal reference line X and a vertical center reference line Y, provided inFIG. 8. The first equalizer arm108ais a thin plate having first and second side surfaces238a,239aseparated by an edge described herein.

A bottom236aof the first equalizer arm108ais provided at the intersection of the horizontal reference line X and the vertical center reference line Y. A first reference point A is provided at a predetermined distance above the bottom236a, for example 2.173 inches above. A second reference point B is provided at a predetermined distance above the reference line X, for example 1.5 inches above, and at a predetermined distance to the left of reference line Y, for example 1.75 inches. Reference points A and B are provided outside of the perimeter of the first equalizer arm108a.

The left side of the first equalizer arm108a(everything to the left of the reference line Y as viewed inFIG. 8) is described, with the understanding that the right side of the first equalizer arm108a(everything to the right of the reference line Y as viewed inFIG. 8) is the mirror image. As such, the edges and reference points on the right side are not described and are denoted with a prime.

From the bottom236a, a first edge portion240aextends straight to the left of reference line Y, along reference line X, for a predetermine distance, for example 1.504 inches. A left end244aof the first equalizer arm108a, which is the furthermost left point along the perimeter of the first equalizer arm108afrom reference line Y, is provided at a predetermined distance from both the reference line X and the reference line Y, for example 0.612 inches above reference line X and 2.794 inches to the left of reference line Y. A second edge portion242aextends straight upwardly and to the left of reference line Y from the first edge portion240ato the left end244a. A top left end248aof the first equalizer arm108ais provided at a predetermined distance from both the reference line X and the reference line Y, for example 1.375 inches above reference line X and 2.432 inches to the left of reference line Y. From the left end244a, a third edge portion246aextends straight upwardly and to the right to the top left end248a. A fifth edge portion252ais formed as an arc about reference point B at a predetermined radius, for example at a radius of 0.535 inches. From the top left end248a, a fourth edge portion250aextends straight to the right toward the reference line Y and parallel to the reference line X, to an end of the fifth edge portion252a. A seventh edge portion256ais formed as an arc about reference point A at a predetermined radius, for example at a radius of 1.338 inches. A sixth edge portion254aextends parallel to the reference line X and is co-planar with the fourth edge portion250a. The sixth edge portion254aconnects the fifth edge portion252ato the seventh edge portion256a. The fifth edge portion252athus curves downwardly and to the right from the fourth edge portion250aand then upwardly and to the right to the sixth edge portion254a. The seventh edge portion256athus curves downwardly and to the right from the sixth edge portion254ato the reference line Y, to a predetermined position above the bottom236a, for example 0.835 inches above.

Attention is directed toFIGS. 9 and 10which illustrate the first lower shock plate110a, which is preferably formed of a forged, cast or fabricated metal. The first lower shock plate110ais identical in shape and configuration to the second lower shock plate110b. As such, only the first lower shock plate110ais described with the understanding that the description of the second lower shock plate100bwould be identical. The elements of the first lower shock plate110awill have reference numerals ending in “a”. As such, it is to be understood that the elements of the second lower shock plate110bwill have like reference numerals ending in “b”.

The first lower shock plate110ais a thin plate which is curved from a first end274athereof to a second end276athereof. The first lower shock plate110ahas a generally uniform predetermined thickness from the first end274ato the second end276a, for example a thickness of 0.125 inches, such that the first lower shock plate110ahas an inner surface278a, an outer surface279a, a first side280a, and a second side281a. The inner surface278ais formed as an arc about reference point A, as illustrated inFIG. 10, at a predetermined radius, for example at a radius of 1.188 inches. The first and second ends274a,276aare provided at a predetermined angle to one another relative to the reference point A, for example an angle of 145 degrees. The first and second ends274a,276aare provided at a predetermined linear distance to one another, for example a distance of 1.563 inches.

Attention is directed toFIGS. 11 and 12which illustrate the first upper shock plate112a, which is preferably formed of a forged, cast or fabricated metal. The first upper shock plate112ais identical in shape and configuration to the second upper shock plate112b. As such, only the first upper shock plate112ais described with the understanding that the description of the second upper shock plate112bwould be identical. The elements of the first upper shock plate112awill have reference numerals ending in “a”. As such, it is to be understood that the elements of the second upper shock plate112bwill have like reference numerals ending in “b”.

The first upper shock plate112ais a thin plate which is curved from a first end282athereof to a second end284athereof. The first upper shock plate112ahas a generally uniform predetermined thickness from the first end282ato the second end284a, for example a thickness of 0.125 inches, such that the first upper shock plate112ahas an inner surface286a, an outer surface287a, a first side288a, and a second side289a. The inner surface286ais formed as an arc about reference point A, as illustrated inFIG. 12, at a predetermined radius, for example at a radius of 1.188 inches. The first and second ends282a,284aare provided at a predetermined angle to one another relative to the reference point A, for example an angle of 160 degrees. The first and second ends282a,284aare provided at a predetermined linear distance to one another, for example a distance of 1.625 inches.

FIGS. 13 and 14illustrate the reinforcement plate114, which is preferably formed of a forged, cast or fabricated metal. The configuration of the reinforcement plate114is defined with reference to a horizontal reference line X and a vertical center reference line Y, provided inFIG. 14. The reinforcement plate114is a generally T-shaped thin plate having first and second side surfaces305,307separated by an edge described herein.

A first reference point A is provided at a predetermined distance below the reference line X, for example 0.75 inches below, and along the reference line Y. A second reference point B is provided at a predetermined distance below the reference line X, for example 1.954 inches below, and at a predetermined distance to the left of reference line Y, for example 4.23 inches. Reference point B is provided outside of the perimeter of the reinforcement plate114, whereas reference point A is provided inside of the perimeter of the reinforcement plate114.

The left side of the reinforcement plate114(everything to the left of the reference line Y as viewed inFIG. 14) is described, with the understanding that the right side of the reinforcement plate114(everything to the right of the reference line Y as viewed inFIG. 14) is the mirror image. As such, the edges and reference point on the right side are not described and are denoted with a prime.

From the intersection of the reference lines X and Y, a first edge portion290extends straight to the left of reference line Y, along the reference line X, for a predetermined distance, for example 1.875 inches. A second edge portion292extends straight downwardly and to the left from the first edge portion290at a predetermined angle, for instance forty-five degrees, to a top end294of a third edge portion296. The third edge portion296is parallel to the reference line Y and is provided at a predetermined distance to the left of reference line Y, for example 2.375 inches. A fifth edge portion300, which is parallel to the reference line X, extends straight to the left from the reference line Y and is provided at a predetermined distance below the reference line X, for example 2.5 inches below. A fourth edge portion298is formed as an arc about reference point B at a predetermined radius, for example 1.338 inches. The fourth edge portion298curves from a bottom end295of the third edge portion296to a left end299of the fifth edge portion300.

An aperture306is formed through the reinforcement plate114and extends from the first side surface305to the second side surface307. The aperture306is formed by a circle with a predetermined radius defined about reference point A, for example with a radius of 0.5625 inches. The aperture306is illustrated as being bisected by the reference line Y such that half of the aperture306is provided on the left side of the reinforcement plate114and such that the other half of the aperture306is provided on the right side of the reinforcement plate114.

FIG. 15illustrates the first shock absorber116a. The first shock absorber116ais identical in shape and configuration to the second shock absorber116b. As such, only the first shock absorber116ais described with the understanding that the description of the second shock absorber116bwould be identical. The elements of the first shock absorber116awill have reference numerals ending in “a”. As such, it is to be understood that the elements of the second shock absorber116bwill have like reference numerals ending in “b”.

The first shock absorber116ais preferably in the form of a cylindrical puck or disk and made of TORSILASTIC® rubber. The first shock absorber116ahas a cylindrical outer surface117aprovided between a first end surface118aand a second end surface (not shown). An aperture307ais provided through the first shock absorber116afrom the first end surface118ato the second end surface. In use, the outer surface117ais positioned between the inner surfaces278a,286aof the first lower shock plate110aand the first upper shock plate112a, respectively and, therefore, has a circumference which is correspondingly shaped to the first lower and upper shock plates110,112. For example, the outer surface117ais formed at a radius of approximately 1.188 inches, which is the radius at which the inner surfaces278a,286aof the first lower and upper shock plates110a,112a, respectively, are formed.

FIGS. 16 and 17illustrate the first upper pivot tube119a, which is preferably formed of a forged, cast or fabricated metal. The first upper pivot tube119ais identical in shape and configuration to the second, third and fourth upper pivot tubes119b,119c,119d. As such, only the first upper pivot tube119ais described with the understanding that the description of the second, third and fourth upper pivot tubes119b,119c,119dwould be identical. The elements of the first upper pivot tube119awill have reference numerals ending in “a”. As such, it is to be understood that the elements of the second upper pivot tube119bwill have like reference numerals ending in “b”; the elements of the third upper pivot tube119cwill have like reference numerals ending in “c”; and the elements of the fourth upper pivot tube119dwill have like reference numerals ending in “d”.

The first upper pivot tube119ahas a first end308aand a second end310a. In a preferred embodiment, a distance from the first end308ato the second end310ais approximately 1.75 inches. The first upper pivot tube119ais formed of an outer tube312aand an inner tube or bushing314a. The outer tube312aextends from the first end308ato the second end310aand has an aperture316awhich extends therethrough from the first end308ato the second end310a. The outer tube312athus has an outer surface318aand an inner surface (not shown). In a preferred embodiment, the outer tube312ahas an outer diameter of approximately 1.07 inches and an inner diameter of approximately 0.75 inches. The inner tube or bushing314ais positioned within the aperture316aof the outer tube312aand extends from the first end308ato the second end310a. The inner tube or bushing314adefines an aperture320awhich extends therethrough from the first end308ato the second end310a. The inner tube314athus has an outer surface (not shown) and an inner surface322a. In a preferred embodiment, the inner tube314ahas an outer diameter of approximately 0.75 inches and an inner diameter of approximately 0.565 inches. The outer surface of the inner tube314ais configured and sized to snugly fit against the inner surface of the outer tube312a.

FIGS. 18 and 19illustrate the first lower pivot tube120a, which is preferably formed of a forged, cast or fabricated metal. The first lower pivot tube120ais identical in shape and configuration to the second lower pivot tube120b. As such, only the first lower pivot tube120ais described with the understanding that the description of the second lower pivot tube120bwould be identical. The elements of the first lower pivot tube120awill have reference numerals ending in “a”. As such, it is to be understood that the elements of the second lower pivot tube120bwill have like reference numerals ending in “b”.

The first lower pivot tube120ahas a first end324aand a second end326a. A distance from the first end324ato the second end326ais predetermined, for example approximately 1.563 inches. The first lower pivot tube120ais formed of an outer tube328aand an inner tube or bushing330a. The outer tube328aextends from the first end324ato the second end326aand has an aperture332awhich extends therethrough from the first end324ato the second end326a. The outer tube328athus has an outer surface334aand an inner surface (not shown). The outer tube328ahas a predetermined outer diameter, for example approximately 1.07 inches, and a predetermined inner diameter, for example approximately 0.75 inches. The inner tube or bushing330ais positioned within the aperture332aof the outer tube328aand extends from the first end324ato the second end326a. The inner tube or bushing330adefines an aperture336awhich extends therethrough from the first end324ato the second end326a. The inner tube330athus has an outer surface (not shown) and an inner surface338a. The inner tube330ahas a predetermined outer diameter, for example approximately 0.75 inches, and a predetermined inner diameter, for example approximately 0.565 inches. The outer surface of the inner tube330ais configured and sized to snugly fit against the inner surface of the outer tube328a.

FIG. 20illustrates the first fastening member122a. The first fastening member122ais identical in shape and configuration to the second and third fastening members122b,122c. As such, only the first fastening member122ais described with the understanding that the description of the second and third fastening members122b,122cwould be identical. The elements of the first fastening member122awill have reference numerals ending in “a”. As such, it is to be understood that the elements of the second fastening member122bwill have like reference numerals ending in “b” and the elements of the third fastening member122cwill have like reference numerals ending in “c”.

The first fastening member122ais preferably a bolt having an enlarged head portion340a, a first shaft portion342a, and a second shaft portion344a. The enlarged head portion340apreferably is a hex-head, but other shapes are within the scope of the invention. The first shaft portion342aextends from the enlarged head portion340aand is preferably cylindrical. The second shaft portion344aextends from the first shaft portion342a, such that the first shaft portion342ais positioned between the enlarged head portion340aand the second shaft portion344a, and is preferably cylindrical and externally threaded. The second shaft portion344apreferably has a predetermined outer diameter which is smaller than a predetermined outer diameter of the first shaft portion342asuch that a shoulder346ais provided between the first and second shaft portions342a,344a. The predetermined outer diameter of the first shaft portion342ais preferably smaller than a predetermined outer diameter of the enlarged head portion340asuch that a shoulder348ais provided between the enlarged head portion340aand the first shaft portion342a.

FIG. 21illustrates the first securing member124a. The first securing member124ais identical in shape and configuration to the second and third securing members124b,124c. As such, only the first securing member124ais described with the understanding that the description of the second and third securing members124b,124cwould be identical. The elements of the first securing member124awill have reference numerals ending in “a”. As such, it is to be understood that the elements of the second securing member124bwill have like reference numerals ending in “b” and the elements of the third securing member124cwill have like reference numerals ending in “c”.

The first securing member124apreferably includes a conventional nut350asecured to a conventional washer352a. The nut350apreferably has a hex-head. The nut350aand the washer352ahave an aperture354aextending therethrough. The aperture354adefines an aperture wall which is preferably at least partially threaded.

FIGS. 22 and 23illustrate the base or shock spacer126, which is preferably formed of a forged, cast or fabricated metal. The base or shock spacer126has a first end356and a second end358. A distance from the first end356to the second end358is predetermined, for example approximately 1.625 inches. The base or shock spacer126is formed as a tube and has an aperture360which extends therethrough from a first end356to a second end358. The base or shock spacer126thus has an outer surface362and an inner surface364. An outer diameter of the base or shock spacer126at the outer surface362thereof is predetermined, for example approximately 1.07 inches, and an inner diameter of the base or shock spacer126at the inner surface364thereof is predetermined, for example approximately 0.75 inches.

FIGS.2and24-38illustrate the construction of the equalizer100alone and in conjunction with the suspension system102, as well as the function of the equalizer100with the suspension system102.

The equalizer100is constructed by forming first and second equalizer arm assemblies366,368. The configuration of the first equalizer arm assembly366is illustrated inFIGS. 24-26. The first equalizer arm assembly366includes the first equalizer arm108a, the first lower shock plate110a, the first upper pivot tube119a, and the first lower pivot tube120a.

The outer surface318aof the outer tube312aof the first upper pivot tube119ais positioned against the fifth edge portion252aof the first equalizer arm108a, such that the first end308aof the first upper pivot tube119aextends outwardly from the first surface238aof the first equalizer arm108aand such that the second end310aof the first upper pivot tube119aextends outwardly from the second surface239aof the first equalizer arm108a. The outer surface318aof the outer tube312aof the first upper pivot tube119ais fixedly secured to the first equalizer arm108a, preferably by welding.

The outer surface334aof the outer tube328aof the first lower pivot tube120ais positioned against the fifth edge portion252a′ of the first equalizer arm108a, such that the first end324aof the first lower pivot tube120aextends outwardly from the first surface238aof the first equalizer arm108aand such that the second end326aof the first lower pivot tube120aextends outwardly from the second surface239aof the first equalizer arm108a. The first end324ais provided closer to the first surface238aof the first equalizer arm108athan is the first end308aof the first upper pivot tube119a, and the second end326ais provided closer to the second surface239aof the first equalizer arm108athan is the second end310aof the first upper pivot tube119a. The outer surface334aof the outer tube328aof the first lower pivot tube120ais fixedly secured to the first equalizer arm108a, preferably by welding.

The outer surface279aof the first lower shock plate110ais positioned against the seventh edge portions256a,256a′ of the first equalizer arm108a, such that the first side280aof the first lower shock plate110aextends outwardly from the first surface238aof the first equalizer arm108aand such that the second side281aof the first lower shock plate110aextends outwardly from the second surface239aof the first equalizer arm108a. The first side280ais substantially flush with the first end324aof the first lower pivot tube120a, and the second side282ais substantially flush with the second end326aof the first lower pivot tube120a. The outer surface279aof the first lower shock plate110ais fixedly secured to the first equalizer arm108a, preferably by welding. The outer surface279aof the first lower shock plate110a, proximate to the first end274athereof, faces, and may abut against, the outer surface318aof the outer tube312aof the first upper pivot tube119a. The outer surface279aof the first lower shock plate110a, proximate to the second end276athereof, faces, and may abut against, the outer surface334aof the outer tube328aof the first lower pivot tube120a.

The second equalizer arm assembly368includes the second equalizer arm108b, the second lower shock plate110b, the second upper pivot tube119b, and the second lower pivot tube120b. The configuration of the second equalizer arm assembly368is identical to the configuration of the first equalizer arm assembly366, illustrated inFIGS. 24-26, except that the outer surface318bof the outer tube312bof the second upper pivot tube119bis positioned against the fifth edge portion252b′ of the second equalizer arm108b, as opposed to the fifth edge portion252b, and the outer surface334bof the outer tube328bof the first lower pivot tube120bis positioned against the fifth edge portion252bof the second equalizer arm108b, as opposed to the fifth edge portion252b′.

Attention is invited to FIGS.2and27-36. The equalizer100is further constructed by forming a reinforcement plate assembly370. The reinforcement plate assembly370includes the reinforcement plate114, the shock spacer126, and the first and second upper shock plates112a,112b.

The shock spacer126is inserted through the aperture306of the reinforcement plate114such that the first end356of the shock spacer126extends outwardly from the first surface305of the reinforcement plate114and such that the second end358of the shock spacer126extends outwardly from the second surface307of the reinforcement plate114. The second end358preferably extends further outwardly from the second surface307than does the first end356from the first surface305. The outer surface362is preferably generally positioned against a wall defined by the aperture306, and the outer surface362is fixedly secured to the reinforcement plate114, preferably by welding. The shock spacer126spaces the reinforcement plate114from the first and second base plates104a,104bThe outer surface287aof the first upper shock plate112ais positioned against the fourth edge portion298of the reinforcement plate114, such that the first side288aof the first upper shock plate112aextends outwardly from the first surface305of the reinforcement plate114and such that the second side289aof the first upper shock plate112aextends outwardly from the second surface307of the reinforcement plate114. The outer surface287aof the first upper shock plate112ais fixedly secured to the reinforcement plate114, preferably by welding. The second side289apreferably extends further outwardly from the second surface307than does the first side288afrom the first surface305. The first side288ais substantially planar with the first end356of the shock spacer126, and the second side289ais substantially planar with the second end358of the shock spacer126.

The outer surface287bof the second upper shock plate112bis positioned against the fourth edge portion298′ of the reinforcement plate114, such that the first side288bof the second upper shock plate112bextends outwardly from the first surface305of the reinforcement plate114and such that the second side289bof the second upper shock plate112bextends outwardly from the second surface307of the reinforcement plate114. The outer surface287bof the second upper shock plate112bis fixedly secured to the reinforcement plate114, preferably by welding. The second side289bpreferably extends further outwardly from the second surface307than does the first side288bfrom the first surface305. The first side288bis substantially planar with the first end356of the shock spacer126, and the second side289bis substantially planar with the second end358of the shock spacer126.

The reinforcement plate assembly370is positioned against the first surface129bof the second base plate104bsuch that the second end358of the shock spacer126, and the second sides289a,289bof the first and second upper shock plates112a,112b, abut against the first surface129bof the second base plate104b. The aperture360of the shock spacer126is aligned with the second aperture188bof the second base plate104b. The reinforcement plate assembly370is fixedly secured to the first surface129bof the second plate104b, preferably by welding the outer surface362of the shock spacer126to the first surface129bof the second plate104b, by welding the outer surface287aof the first upper shock plate112ato the first surface129b, proximate to the fourth edge portion138bthereof, and by welding the outer surface287bof the second upper shock plate112bto the first surface129b, proximate to the fourth edge portion138b′ thereof.

The third upper pivot tube119cis positioned within the first portion182bof the first aperture180bof the second base plate104bsuch that the second end310cof the third upper pivot tube119cis substantially flush with the second surface131bof the second base plate104b. The outer surface318cof the outer tube312cof the third upper pivot tube119cis fixedly secured to the first surface129bof the second base plate104b, preferably by welding.

The fourth upper pivot tube119dis positioned within the second portion184bof the first aperture180bof the second base plate104bsuch that the second end310dof the fourth upper pivot tube119dis substantially flush with the second surface131bof the second base plate104b. The outer surface318dof the outer tube312dof the fourth upper pivot tube119dis fixedly secured to the first surface129bof the second base plate104b, and to the outer surface318cof the outer tube312cof the third upper pivot tube119c, preferably by welding.

The first equalizer arm assembly366is positioned such that the second end326aof the first lower pivot tube120afaces the first surface129bof the second base plate104b. The aperture336aof the first lower pivot tube120ais in alignment with the aperture190bprovided through the second base plate104b. The inner surfaces278a,286aof the first lower and upper shock plates110a,112aface one another. The first shock absorber116ais positioned between the inner surfaces278a,286aof the first lower and upper shock plates110a,112asuch that the outer surface117aof the first shock absorber116agenerally abuts against or faces the inner surfaces278a,286aof the first lower and upper shock plates110a,112a. The first shock absorber116ais held in place between the first lower and upper shock plates110a,112a. The first end274aof the first lower shock plate110ais spaced from the first end282aof the first upper shock plate112a. The second end276aof the first lower shock plate110ais spaced from the second end284aof the first upper shock plate112a.

The second equalizer arm assembly368is positioned such that the second end326bof the second lower pivot tube120bfaces the first surface129bof the second base plate104b. The aperture336bof the second lower pivot tube120bis in alignment with the aperture192bprovided through the second base plate104b. The inner surfaces278b,286bof the second lower and upper shock plates110b,112bface one another. The second shock absorber116bis positioned between the inner surfaces278b,286bof the second lower and upper shock plates110b,112bsuch that the outer surface117bof the second shock absorber116bgenerally abuts against or faces the inner surfaces278b,286bof the second lower and upper shock plates110b,112b. The second shock absorber116bis held in place between the first lower and upper shock plates110b,112b. The first end274bof the second lower shock plate110bis spaced from the first end282bof the second upper shock plate112b. The second end276bof the second lower shock plate110bis spaced from the second end284bof the second upper shock plate112b.

The first base plate104ais positioned, as illustrated inFIG. 30, such that the first end308cof the third upper pivot tube119cextends into, from the second surface131aof the first base plate104a, the first portion182aof the first aperture180aof the first base plate104a; such that the first end308dof the fourth upper pivot tube119dextends into, from the second surface131aof the first base plate104a, the second portion184aof the first aperture180aof the first base plate104a; such that the first end356of the shock spacer126faces the second surface131aof the first base plate104a, with the aperture360of the shock spacer126being in alignment with the second aperture188aof the first base plate104a; such that the first end324aof the first lower pivot tube120afaces the second surface131aof the first base plate104a, with the aperture336aof the first lower pivot tube120abeing in alignment with the third aperture190aof the first base plate104a; such that the first end324bof the second lower pivot tube120bfaces the second surface131aof the first base plate104a, with the aperture336bof the second lower pivot tube120bbeing in alignment with the fourth aperture190a′ of the first base plate104a; such that the first sides280a,280b,288a,288bof the first and second lower and upper shock plates110a,110b,112a,112b, respectively, face the second surface131aof the first base plate104a; and such that the first surfaces118a,118bof the first and second shock absorbers116a,116b, respectively, face the second surface131aof the first base plate104a.

As illustrated inFIG. 31, the second surface197aof the first secondary base plate106ais positioned against the first surface129aof the first base plate104asuch that the first aperture230aof the first secondary base plate106ais in alignment with the second aperture188aof the first base plate104a, the second aperture232aof the first secondary base plate106ais in alignment with the third aperture190aof the first base plate104a, and the third aperture232a′ of the first secondary base plate106ais in alignment with the fourth aperture192aof the first base plate104a. The first secondary base plate106ais fixedly secured to the first surface129aof the first base plate104a, preferably by welding.

Likewise, although not explicitly illustrated, the first surface195bof the second secondary base plate106bis positioned against the second surface131bof the second base plate104bsuch that the first aperture230bof the second secondary base plate106bis in alignment with the second aperture188bof the second base plate104b, the second aperture232bof the second secondary base plate106bis in alignment with the third aperture190bof the second base plate104b, and the third aperture232b′ of the second secondary base plate106bis in alignment with the fourth aperture190b′ of the second base plate104b. The second secondary base plate106bis fixedly secured to the second surface131bof the second base plate104b, preferably by welding.

As best illustrated inFIG. 32, the first fastening member122aextends through the first aperture230bof the second secondary base plate106b, through the second aperture188bof the second base plate104b, through the aperture360of the shock spacer126, through the second aperture188aof the first base plate104a, and through the first aperture230aof the first secondary base plate106a, such that the shoulder348aof the first fastening member122aabuts against the second surface197bof the second secondary base plate106band at least a portion of the threaded, second shaft portion344aof the first fastening member122aextends beyond the first surface195aof the first secondary base plate106a. The first securing member124ais threaded onto the threaded, second shaft portion344aof the first fastening member122asuch that the washer member352ais tightly positioned against the first surface195aof the first secondary base plate106a. The reinforcement plate assembly370is thus fixedly secured to the first base plate104aby the first fastening and securing members122a,124a.

The second fastening member122bextends through the second aperture232bof the second secondary base plate106b, through the third aperture190bof the second base plate104b, through the aperture336aof the first lower pivot tube120a, through the third aperture190aof the first base plate104a, and through the second aperture232aof the first secondary base plate106a, such that the shoulder348bof the second fastening member122babuts against the second surface197bof the second secondary base plate106band at least a portion of the threaded, second shaft portion344bof the second fastening member122bextends beyond the first surface195aof the first secondary base plate106a. The second securing member124bis threaded onto the threaded, second shaft portion344bof the second fastening member122bsuch that the washer member352bis tightly positioned against the first surface195aof the first secondary base plate106a.

The third fastening member122cextends through the third aperture232b′ of the second secondary base plate106b, through the fourth aperture190b′ of the second base plate104b, through the aperture336bof the second lower pivot tube120b, through the fourth aperture190a′ of the first base plate104a, and through the third aperture232a′ of the first secondary base plate106a, such that the shoulder348cof the third fastening member122cabuts against the second surface197bof the second secondary base plate106band at least a portion of the threaded, second shaft portion344cof the third fastening member122cextends beyond the first surface195aof the first secondary base plate106a. The third securing member124cis threaded onto the threaded, second shaft portion344cof the third fastening member122csuch that the washer member352cis tightly positioned against the first surface195aof the first secondary base plate106a. The first equalizer arm assembly366is thus rotatably secured or pivotally mounted between the first and second base plates104a,104bby the second fastening and securing members122b,124b. The second equalizer arm assembly368is thus rotatably secured or pivotally mounted between the first and second base plates104a,104bby the third fastening and securing members122c,124c.

The equalizer100is thus provided as illustrated inFIG. 32.

As illustrated inFIGS. 2,33,35and36, the equalizer100is secured to a center frame hangar372which depends from a frame374of a trailer (not shown). The center frame hangar372is generally U-shaped such that it has a base portion376and first and second portions378,380which extend downwardly from opposite ends of the base portion376. The base portion376is fixedly secured to the frame374of the trailer by known means, such as welding. The first extending portion378has an aperture382extending therethrough proximate to a free end384. The second extending portion380has an aperture386extending therethrough proximate to a free end388. The apertures382,386are in alignment with one another and the free ends384,388are preferably planar.

As illustrated inFIGS. 2,33and35-38, the first and second base plates104a,104bare positioned between the first and second extending portions378,380of the center frame hangar372such that the first surface129aof the first base plate104afaces the first extending portion378, and the second surface131bof the second base plate104bfaces the second extending portion380. The second portion184aof the first aperture180aof the first base plate104ais in alignment with the aperture382of the first extending portion378of the center frame hangar372. Likewise, the second portion184bof the first aperture180bof the second base plate104bis in alignment with the aperture386of the second extending portion380of the center frame hangar372. A fastening member390, which may be identical to or different from the fastening members122a,122b,122ccan be inserted through the aperture386of the second extending portion380of the center frame hangar372, through the second portion184bof the first aperture180bof the second base plate104b, through the aperture320dof the fourth upper pivot tube119d, through the second portion184aof the first aperture180aof the first base plate104a, and through the aperture382of the first extending portion378of the center frame hangar372. A securing member392, which may be identical to or different from the fastening members124a,124b,124ccan then be secured to the fastening member390such that the equalizer100is rotatably secured or pivotally mounted between the first and second extending portions378,380of the center frame hangar372by the fastening and securing members390,392.

It should be noted that, alternatively, the equalizer100can also be rotatably secured or pivotally mounted between the first and second extending portions378,380of the center frame hangar372by the fastening and securing members390,392, as illustrated inFIG. 34. InFIG. 34, the first portion182aof the first aperture180aof the first base plate104ais in alignment with the aperture382of the first extending portion378of the center frame hangar372and the first portion182bof the first aperture180bof the second base plate104bis in alignment with the aperture386of the second extending portion380of the center frame hangar372. As such, the fastening member390can be inserted through the aperture386of the second extending portion380of the center frame hangar372, through the first portion182bof the first aperture180bof the second base plate104b, through the aperture320cof the third upper pivot tube119c, through the first portion182aof the first aperture180aof the first base plate104a, and through the aperture382of the first extending portion378of the center frame hangar372. The securing member392can then be secured to the fastening member390.

Thus, the configuration of the equalizer100allows for two different connections to the center frame hangar372of the frame374of the trailer depending on the desired position of the equalizer100relative to the frame374of the trailer.

As illustrated inFIG. 2, the suspension system102includes the equalizer100, a front leaf spring394, a rear leaf spring396, a front shackle or link398and a rear shackle or link400. As discussed above, the equalizer100is rotatably secured or pivotally mounted to the center frame hangar372of the frame374of the trailer, illustrated at a point J inFIG. 2. A first end402of the front shackle398is rotatably secured or pivotally mounted to the first equalizer arm assembly366, at a point K. The first end402of the front shackle398is rotatably secured or pivotally mounted to the first equalizer arm assembly366by a fastening member and a securing member. The fastening member extends through apertures of the front shackle398and the aperture320aof the first upper pivot tube119a. A first end404of the rear shackle400is rotatably secured or pivotally mounted to the second equalizer arm assembly368, at a point L. The first end404of the rear shackle400is rotatably secured or pivotally mounted to the second equalizer arm assembly368by a fastening member and a securing member. The fastening member extends through apertures of the rear shackle400and the aperture320bof the second upper pivot tube119b. The fastening members may be identical to or different from the fastening members122a,122b,122c. The securing members may be identical to or different from the securing members124a,124b,124c.

A second end406of the front shackle398is rotatably secured or pivotally mounted to a rear end408of the front leaf spring394at a point M. A front end410of the front leaf spring394is attached to a front frame hangar411of the frame374at a point N, as illustrated inFIG. 2, or can be directly attached to the frame374itself, depending on the configuration of the frame374.

A second end412of the rear shackle400is rotatably secured or pivotally mounted to a front end414of the rear leaf spring396at a point P. A rear end416of the rear leaf spring396is attached to a rear frame hangar417of the frame374at a point Q, as illustrated inFIG. 2, or can be directly attached to the frame374itself, depending on the configuration of the frame374.

A front axle418of the trailer is positioned on the forward leaf spring394generally equidistantly between point M and point N. A rear axle420is positioned on the rear leaf spring396generally equidistantly between point P and point Q.

It is to be understood that while only a single suspension system102is illustrated and described, it is typical to have one suspension system102provided on both a left and a right side of a trailer. If more than two axles are provided on the trailer, it is to be understood that two or more suspension systems102can be provided on both a left and a right side of the trailer.

Like the prior art suspension system20including the equalizer22illustrated inFIG. 1, to the extent possible, road shock and vibrations from tires (not shown) of the trailer, utilizing the suspension system102including the equalizer100of the present invention, are transferred to the front and rear axles418,420, and are absorbed by the front and rear leaf springs394,396, respectively. Points J, N and Q are the contact points through which the road shock is passed to the frame374. The equalizer100is included in the suspension system102in order to equalize the weight on both the front and rear axles418,420as the tires pass over uneven terrain. For example, an upward motion of the front leaf spring394results in a downward motion of the rear leaf spring396.

As illustrated inFIGS. 37 and 38, the equalizer100, unlike the equalizer22of the prior art, is configured to dampen or absorb the harsh shocks or vibrations coming off the rear end408of the front leaf spring394and the front end414of the rear leaf spring396proximate to the center frame hangar372, thereby allowing for a “softer” ride.

When the front leaf spring394moves upward, the equalizer100rotates upwardly and to the left relative to the center hangar372about point J, as illustrated inFIG. 37, such that the rear leaf spring396moves downward, thus equalizing the weight on both the front and rear axles418,420. Further, when the front leaf spring394moves upward, the first equalizer arm assembly366rotates or pivots upwardly between the first and second base plates104a,104bby the second fastening and securing members122b,124babout a point R. As the first equalizer arm assembly366rotates or pivots upwardly, the first lower shock plate110aof the first equalizer arm assembly366is forced against a portion of the outer surface117aof the first shock absorber116a, thus forcing another portion of the outer surface117aagainst the first upper shock plate112a. Under this force, the first shock absorber116adeforms between the first lower and upper shock plates110a,112a, such that the first ends274a,282aof the first lower and upper shock plates110a,112amove toward one another and, such that the second ends276a,284aof the first lower and upper shock plates110a,112amove toward one another. Upon deformation, the first shock absorber116aabsorbs or dampens the harsh shocks or vibrations coming off the rear end408of the front leaf spring394, which would otherwise be transferred through the equalizer to the center frame hangar372and, thus, to the frame374of the trailer. Therefore, a “softer” ride is achieved by the suspension system102including the equalizer100of the present invention.

Likewise, when the rear leaf spring396moves upward, the equalizer100rotates upwardly and to the right relative to the center hangar372about point J, as illustrated inFIG. 38, such that the front leaf spring394moves downward, thus equalizing the weight on both the front and rear axles418,420. Further, when the rear leaf spring396moves upward, the second equalizer arm assembly368rotates or pivots upwardly between the first and second base plates104a,104bby the third fastening and securing members122c,124cabout a point S. As the second equalizer arm assembly368rotates or pivots upwardly, the second lower shock plate110bof the second equalizer arm assembly368is forced against a portion of the outer surface117bof the second shock absorber116b, thus forcing another portion of the outer surface117bagainst the second upper shock plate112b. Under this force, the second shock absorber116bdeforms between the second lower and upper shock plates110b,112b, such that the first ends274b,282bof the second lower and upper shock plates110b,112bmove toward one another and, such that the second ends276b,284bof the second lower and upper shock plates110b,112bmove toward one another. Upon deformnation, the second shock absorber116babsorbs or dampens the harsh shocks or vibrations coming off the front end414of the rear leaf spring396, which would otherwise be transferred through the equalizer to the center frame hangar372and, thus, to the frame374of the trailer. Therefore, a “softer” ride is achieved by the suspension system102including the equalizer100of the present invention.

The equalizer100and the suspension system102which includes the equalizer100is advantageous and beneficial for a “softer” ride in comparison to the prior art equalizer22and the prior art suspension system100which includes the prior art equalizer22.

While a preferred embodiment of the invention is shown and described, it is envisioned that those skilled in the art may devise various modifications without departing from the spirit and scope of the foregoing description and the appended claims.