MXPA96001820A - Suspension lock mechanism with auto-direcc - Google Patents

Abstract

The present invention relates to a locking mechanism for a wheel bearing axle suspension system, with self-steering of a vehicle, the suspension system includes a wheel carrying axle, steering means for steering the wheels of the system and means for connecting the wheel carrying axle and the steering means in travel contact relation with a frame member of the vehicle, characterized in that: the locking mechanism comprises a cylinder connectable to the steering means, the cylinder has a container with walls for fluid therein, a substantial fluid within the container, a piston within the fluid container having a piston head slidable within the container and extending through the fluid container in fluid sealing engagement with the fluid walls thereof to define a first compartment for fluid and a second compartment for fluid separated from the first compartment for As the fluid is fluidized by the piston head, the piston head has a hole therein to thereby define a fluid flow path between the first and second fluid compartments, the locking mechanism further includes a valve associated with the fluid orifice. the piston head for opening and closing the orifice to the fluid flow between the first and second fluid compartments, and a control for actuating the valve to its open or closed position, whereby when the orifice is substantially closed, the locking mechanism prevents any substantial steering of the wheels and when the hole is open the wheels can be directed

Description

SUSPENSION BLOCKING MECHANISM WITH SELF-DIRECTION Field of the invention This invention relates to axle suspension systems with auto-steering for wheeled vehicles. More particularly, this invention relates to locking mechanisms to prevent or control the direction of such suspension systems.

BACKGROUND OF THE INVENTION In recent years, self-steering axle suspension systems, particularly in the medium and heavy-duty truck and two-wheel semi-trailer industry that rests on the pincer of the tractor, have become quite popular. Generally speaking, such suspensions are made of self-steering by adjusting the space or angle of drag (angle of the pivot with the vertical in the longitudinal direction) of the wheels, in such a way that the drag of the wheels as the vehicle advances in the forward direction causes the suspension (that is, the wheels of the system) to be directed or directed automatically in response to the direction of the vehicle. Common to such suspensions are those axes referred to as "drive", "herret" or "rear carrier shafts" axes found on trucks and semi-trailers. They can be of the elevable or non-elevatable type. In most self-steering suspensions in common use, a steering moderator or a pair of moderators are used to suppress (dampen) oscillations during vehicle operation on the road. While such moderators come in a wide variety of styles, a known type is similar in construction to a conventional shock absorber, either with or without an external helical coil spring. Commonly referred to as "stabilizers" are such devices. In such a moderator, a large cylinder is provided, which houses a fluid container that is filled almost completely with a hydraulic fluid (ie, incompressible). This cylinder is separated into two compartments by a piston having a hole, or holes, in its head, to thereby form a flow path between the two compartments, but which otherwise seals the two compartments against fluid flow between the two compartments. the same. The moderation or damping is carried out by joining one end of the cylinder (usually by a piston rod attached to the piston head) to the suspension steering mechanism and the other end to the axle or oscillating lever structure of the suspension of the piston. vehicle (or vice versa). Since the hole (s) in the piston head restricts (n) the flow between the two compartments as the piston slides in the cylinder due to oscillations experienced during the operation of the vehicle (e.g. the road and "abnormal movements of oscillation and lifting of the front wheels"), such oscillations are moderated properly and the direction of the traffic is stabilized. In the self-steering suspensions, the driving angle, as mentioned above, is appropriately adjusted, in a conventional manner, to create the direction during the forward movement of the vehicle (eg as the vehicle moves along a curve). ). When the vehicle is backed up, however, the driving angle is no longer correct and the tires may tend to drive on the road in an inappropriate manner. Indeed, the tires can really tend to be directed or completely oriented to one side or the other, sometimes quite abruptly. This, of course, is undesirable, which can give rise to maneuverability difficulties or damage to the suspension.

- - Several technologies have been developed to address the above problem. The most common is to use some form of mechanical linkage which blocks the direction of the suspension (that is, the wheels) when the vehicle is placed in its counter-march mode of operation. Two systems presently known in use are the so-called "bar fixing" and "pivot fixing" systems. In the "bar fixing" system, it is caused that a bar (or, more appropriately, a fixing arm) oscillates to a fixation position by air actuation with the use of appropriate valvulería of the brake chamber. When the fixing arm swings in place, it is brought into contact with an opening in the plate of the connecting rod of the suspension steering mechanism. Since this plate is attached to the connecting rod of the steering mechanism and the arm is finally joined to the shaft, the steering is impeded. The "pivot lock" is somewhat similar to the bar fastening system, since it operates under the same principle, but uses a bolt or driven pivot instead of a bar. When an air cylinder is actuated, it urges a spring loaded bolt to move down through an opening in the tie rod plate, thereby returning the steering system inoperative. The various blocking devices and techniques known before the present invention have one or more disadvantages associated with their use. For most, they are usually difficult to install, are heavy and complex in the number of parts required to be added to the suspension as additional items, and often require considerable maintenance. Some have the potential for unsafe blocking coupling, and many require the use of additional buffers or moderators because, by themselves, they have no capacity in this regard. In view of the above, it is evident that there is a need in the art for a blocking mechanism which is not subject to the above disadvantages in the prior art. It is a purpose of this invention to satisfy this need in the art, as well as other needs which will become apparent to one skilled in the art given the following description.

BRIEF DESCRIPTION OF THE INVENTION Generally speaking, this invention meets the needs described above in the art, by providing a locking mechanism for a self-steering suspension which, for the first time, and in a unique manner, employs the internal cavity, and parts, of the that in the past it has only been used as the buffer-like moderator to dampen oscillations and reduce "abnormal movements of oscillation and lifting of the front wheels". By making certain modifications and rather simple additions to the piston rod and head of this known moderator, a highly reliable locking mechanism is obtained, still easily installable and relatively light in weight. In certain embodiments of this invention, therefore, a locking mechanism is provided for a suspension system with a wheel-carrying axle, for self-steering a vehicle, the suspension system includes an axle that carries the wheels, steering means for steering the wheels of the system, and means for joining the wheel carrying axle and the steering means in travel engagement relationship to a frame member of the vehicle; the locking mechanism comprises a cylinder connectable to the steering means, this cylinder has a container with walls for the fluid therein, a substantially incompressible fluid (for example liquid or gas) inside the container, a piston inside the fluid container having a piston head slidable within the container and extending through the fluid container in fluid sealing engagement with the walls thereof, to define a first compartment for the fluid and a second compartment for the fluid, separated from the first compartment for the fluid through the piston head, the piston head has a hole therein, to thereby define a fluid flow path between the first and second fluid compartments; the locking mechanism further includes a valve associated with the orifice of the piston head for opening and closing the orifice to the fluid flow between the first and second fluid compartments, and a control for actuating the valve to its open and closed positions; whereby, when the orifice is substantially fully closed the locking mechanism substantially prevents any steering of the wheels and when the orifice is open the wheels are addressable. In certain additional embodiments of this invention, the extent to which the valve of the locking mechanism opens determines the degree of ease of steering of the self-steering suspension. Controls are thus provided to carry out a fully open, partially open, or completely closed fluid flow path. In this way, when the flow path is completely closed the direction is fully blocked effectively, because the fluid in the container is not allowed to flow between the dDS fluid compartments. However, in certain other embodiments of this invention, sufficient fluid is allowed to flow, such as by incomplete tolerance between the seal of the piston head and the container wall, or by such inaccurate tolerance in the valve head, in such a way that even in its most closed or fully closed mode, the cylinder is effective to act as a shock-absorbing moderator to absorb oscillations and prevent "abnormal movements of oscillation and lifting of the front wheels". In short, in such an arrangement the blocking mechanism acts as a moderator regardless of the mode of actuation or deactivation in which it is placed. In still further embodiments, by means of the use of a pressure regulator, the sanctity of closing the flow path by the piston is modulated in such a way that, for example, a high degree of blockage is made if the vehicle makes a lane change or sudden track, but significant addressability is provided if the vehicle is on a large curve.

In still more embodiments, the locking mechanism is provided with one or more detectors. A detector operates to detect when the vehicle is in its counter-gear gear (travel direction) and deactivates the lock at that time or that time. Another detector functions to detect a predetermined forward travel speed (for example 72 km / h (45 miles / hour)) such that at this speed or at a higher speed, blocking is activated. Either one or the other or both of these detectors can be used. This invention will now be described in relation to certain modalities thereof, as summarized in the accompanying illustrations, wherein: BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a partial side plan view of a known type of vehicle with addressable liftable axle, wheel carrier, but in one embodiment of a locking mechanism according to the present invention. Figure 2 is a top plan view of the embodiment of Figure 1. Figure 3 is a top plan view of a known type of steerable axle, but incorporating - therein a modality of a locking mechanism of according to this invention. Figure 4 is a side sectional view of one embodiment of a locking cylinder according to this invention. Figure 5 is a partial side sectional view of the valve mechanism illustrated in Figure 4 and further illustrating the flow path in its fully open position according to an embodiment of this invention. Figure 6 is a partial side sectional view of the valve mechanism of Figure 4, but illustrating the flow path in its fully closed position. Figure 7 is a schematic view of one embodiment of a control mechanism according to this invention. Figures 8a and 8b are plan views of the liftable axle embodiment of Figure 1 in their "elevated" and "road contact" positions, respectively. Figure 9 is a graph illustrating a representative modulating pre-adjustment curve, for the embodiment of Figure 1, if modulation is to be incorporated into the system.

Fig. 10 is a partial side sectional view of the valve of Figs. 4-6 in its modulated, partially open position, as determined by the pre-adjustment established by use of the curves of Fig. 9.

Detailed description of certain modalities Before describing the illustrated embodiments in detail, it will be noted that the term "blocking", as used herein, is used in its conventional, but broad sense. That is, the term "blocking" is used herein to imply that the ability to address, to some significant extent, has become more difficult in effecting the blocking mode of the mechanisms of this invention. Thus, the "block" can be either partial or complete. When, for example, the amount of blockage effected is termed "full" or "fully closed" (with reference to the flow path), these terms are used to imply that no substantial addressability can be present in the wheels of Another addressable way of the suspension system involved. In some systems this may mean complete non-addressability and blocking against any substantial oscillatory movement. In most of the systems contemplated, however, these two terms are used to refer to a system where, while the directional capacity or directionality itself has been effectively eliminated, the system still acts as a buffer effective against oscillatory movements, which include the "abnormal movements of oscillation and lifting of the front wheels" during the operation of the vehicle (for example by means of linkage through the valve as mentioned above). Reference is now made to figures 1-2. In these figures, a liftable axle suspension is illustrated, which finds particular utility as an environment in which the locking mechanisms of this invention are used. The illustrated suspension is a modality, in this respect, of the unique, addressable, wheel bearing, lift axle suspension systems described in U.S. Patent No. 5,403,031. The full description of this patent is incorporated herein by reference, which includes discussion of the addressable nature of the suspension by adjusting the drag angle to produce the self-direction of the suspension. It also describes the nature of how the system rises and collapses according to the unique bidirectional expansion and contraction characteristics of this patented system. Such characteristics are of the prior art prior to the present invention and serve as an advantageous environment in which the blocking mechanism of this invention can be used efficiently and effectively. As a brief reference to this lifting axle, illustrated in Figures 1-2, a pair of parallel oscillating levers 1, 3 pivotally connected at their forward ends by means of pivots 5a, 5b to the bracket or hanging bracket 7 are illustrated. which, in turn, is bolted to the longitudinal frame member 9 of the vehicle 11. The parallel oscillating levers 1 and 3 are pivotally connected at their rear ends to the pivots 13a, 13b. The pivot 13a, of course, contains the mechanism as illustrated (and as fully described in US Pat. No. 5,403,031 mentioned above) for adjusting the drive angle t by rotating the eccentric cam 15 by the required amount. (As illustrated "kp" is the center line of the main bolt and the adjustable angle is usually + 3 ° to + 6 °). Referring next to Figures 8a, 8b, a representative vehicle is shown. The vehicle 11 has a body 107, a non-addressable suspension 109. which carries wheels, not liftable, as a main supporting means, and the lifting axle suspension bearing wheels of Figures 1, 2 which is designated in general as 111. The bed of the road, or floor, is generally designated as 113. The vehicle 11, in this respect, can be any type of vehicle which employs a lift-axle suspension system or non-lift, addressable. Examples include heavy-duty dump trucks, semi-trailers, and the like. Figures 1 and 8b illustrate the suspension in its "knocked down" or "in road contact" position. Figure 8b, of course, shows the suspension 111 in its "raised" or "elevated" position. As more fully described and illustrated in the aforementioned U.S. Patent No. 5,403,031, the raising and lowering of the suspension 111 is carried out by expanding and contracting the air bellows 17 and 19, respectively. The bellows 17, in this respect, is joined at its upper end to the frame 9 and at its lower end to the pedestal 21 on the seat element 23 of the shaft which, in turn, joins the axis 25. The axis 25, in turn, it joins the wheel (and tire) 27. It is understood, of course, that Figures 1-2 illustrate only one side of a representative vehicle and that the suspension in full form is actually duplicated on the other side of the vehicle. vehicle with the axis 25 which is a linking structure between them. Thus, by expanding the bellows 17 and evacuating the bidirectional bellows 19, the wheels are folded in engagement with the path with the surface 113 of the floor. By expanding the bidirectional bellows 17 (joined between the brackets 29a, 29b attached to the oscillating levers 1, 3 respectively, for bidirectional expansion) and evacuating the bellows 17, the wheels 27 are lifted off the road coupling as shown in the figure 8a. The air controls, with the use of the air source of the brakes, to carry out the lifting and the abatement, are conventional and well known in the industry. As mentioned above, the suspension 111 becomes addressable when it is in engagement with the path, as illustrated in Figures 1-2 and 8b by appropriate adjustment of the drive angle, for example to a positive drive angle ta of approximately 3 - 6. The steering capability is conventionally provided by a conventional steering mechanism which includes a steering arm 31, and connecting rod 33, which together with a conventional spindle arrangement (not shown) addresively addressable wheel to the axis. When such addressability is effected, there sometimes arises a need to provide a locking mechanism to control the steering capability. As stated above, it was previously known to this invention the provision in this steering mechanism of a simple stabilizer, which, from all external appearances, looked similar to the blocking cylinder 35. Optionally, in addition, such stabilizers were provided with a helicoildal spring 37 of self-center of known construction. Prior to this invention, however, such stabilizers were used only to moderate oscillations that included "abnormal movements of oscillation and lifting of the front wheels" during the operation of the vehicle. They had no substantial or significant delay effect on the ability to address. Thus, if desired, prior to the present invention, a blocking feature in an addressable suspension, significant additional expense, time, weight, and installation costs had to be incurred to add a locking mechanism which was separate from the This stabilizer (for example the "bar" or "pivot" locking mechanism mentioned above). It is, therefore, a unique feature and distinctive advantage of this invention that full blockage can be provided on selective demand, without the need for such additional locking mechanism. Rather, this invention makes a portion of its incomparability by using, by means of modification, the internal structure of another conventional way of the stabilizers similar to conventional shock absorbers of the past, to obtain the desired blocking characteristics. In certain embodiments, in fact, it is contemplated that the locking is performed, at the same time, by maintaining the damping characteristics of the known outriggers even when the system has blocked steering capability. In such embodiments the need to add a separate locking mechanism or stabilizer, in addition to the suspension is eliminated. Figure 2 (Figure 1 is a side view thereof), in this regard, illustrates the locking cylinder 35 in a position either in a direct mode or as the wheel 27 is directed at an angle &; . to make a turn (the partial wheel is shown). As can be seen, the proto-typical shock absorber-like structure of the locking cylinder 35 has been expanded (during turning) to separate the cover 39 from the housing 41 from the container, to expose the rod 43 of the piston. It will be recalled, in this regard, that in most of the usual embodiments, the system illustrated in Figures 1-2 is duplicated on the other side of the vehicle, such that the lock cylinder 35 on the other side located opposite in the opposite direction, to thereby provide a mechanism which functionally handles both wheels equally as each turns according to the connection link obtained by the connecting rod 3 and the respective steering arms 31 on the other side of the vehicle. The nature of this steering link, also as a way of joining the locking cylinders 35 to the various other parts of the system, is best illustrated in Figure 3. In this figure, the tires have been separated from the wheels 27 for a better visualization of the system. However, the spring brakes 45 are illustrated. As shown, the end of the rod 43 of the piston, having the cover 39 of the locking cylinder 35, is connected via the brackets or brackets 47 to the shaft 25, while the opposite end of the cylinder 35, that is, the container, is pivotally attached to the steering arms 31 by pivot connections 49. In this way, the locking cylinders 35 are joined in the opposite direction, one from the other, to thereby oppose each other functionally, in order to appropriately handle the oscillations and abnormal movements of oscillation and lifting of the front wheels, also as steering in the two opposite wheels 27. The shaft bearings 51, of course, are the place for the shaft seat member 23 and the air bellows 17. It is also stated that the locking cylinders 35 can optionally be provided with coil springs 37. self-centering if desired, as illustrated in Figure 2. As mentioned above, one skilled in the art when visualizing the modalities of Figures 1-3 from the outside would not normally be able to tell the difference between the prior art embodiments utilizing non-blocking stabilizers, resembling buffers and the present invention, except for the air lines 53 (see Figure 3) that they are attached to the end of each piston rod 43 (as more fully described later). However, if that same technician were to dismantle what would normally be considered only a buffer or stabilizer, the difference would be immediately evident. This difference is best illustrated with reference to Figures 4-6 and 10. With reference first to Figure 4, the locking cylinder 35 includes the pivot connection 49, the housing 41 of the container, the cover 39 and the stem 43 of the container. piston. Conventionally, the cover 39 is attached to the piston rod 43, to move with it. The rod 43 of the piston is attached at one end to the head 55 of the piston. The head 55 of the piston extends through the internal cavity of the housing 41 of the container and sealingly, but slidably, comes into contact with the inner wall 57 of the housing 41, which inner wall 57, together with the end caps 59, 61, define a container 63 for fluid therein. As constructed, the head 55 of the piston separates the container 63 in a first compartment 65 for fluid and a second compartment 67 for fluid. Since the end 69 of the rod 43 of the piston is attached to, for example, the shaft 25, while the connection 49 is connected to the steering arm 31 (or vice versa), the structure as shown provides a stabilizer, buffer function , common, due to the formation of a fluid flow path in the head 55 of the piston, such that the first compartment 65 is in fluid flow communication with the second compartment 67. In this regard, the container 63 is generally substantially filled with a hydraulic fluid (this is incompressible). However, other "fluids" that is, defined herein broadly as liquids or gases, or combinations thereof, may be used if desired. Thus, by restricting the size of the flow path through a hole (s) 71 in the head of the piston between the compartments 65, 67 a moderator is provided to control the oscillation and abnormal movements of oscillation and lifting. of the front wheels as the head 55 of the piston slides inside the wall 57 due to oscillations, which impel the fluid from one compartment to the other. Now, for the first time, this invention modifies this internal, and otherwise conventional, structure to obtain a unique locking mechanism. This is accomplished by forming at least one, and usually two or more, side holes 75 at the end of the piston head of the piston rod 43 and a longitudinal intersecting orifice 77 extending centrally through the piston. the length of the rod 43 of the piston, which finally communicates with the hole 71 of the piston head. In this manner, a fluid flow path is formed between the first fluid compartment 65 and the second fluid compartment 67. Then, by including an adjustable valve mechanism 79 at the interface of the holes 71, 75 and 77, a unique locking mechanism is provided. One embodiment of a valve mechanism 79 as contemplated herein and as illustrated in Figure 4 is also illustrated in Figures 5-6. While the mechanism shown in these figures is in the nature of a sliding spool valve, it is understood that various other types of valves can be used, such as a ball valve, to accomplish the same results. Such other types of valves are considered so to be a "valve" within the meaning of this term as used herein and are thus within the scope of the present invention. As illustrated, the valve 79 is located at the intersection of the bore 71 of the piston head, the side hole 75 of the piston rod and the longitudinal bore 77 of the piston rod. The valve 79 includes a spool provided with a pair of end spaces 83 spaced at their circumferential edges by a sealing o-ring 85. An additional sealing o-ring 87 is provided at the other end of the spool 81 similarly separating two portions 89 of space. The valve 79 further includes a spring retaining cap 91, which has a central hole 93 aligned with the hole 71 of the piston head. The cover 91 retaining the spring 91 is cup-shaped, so as to receive the pre-disposed helical spring 73 in its internal cavity. The pre-disposed helical spring 73 has a diameter and helical spring size which, together with the spacing between each continuous winding, does not adversely affect the flow of fluid through the holes 75, 77, 93 and 71 (or vice versa). Such holes, in this regard, define and form a fluid flow path FFP which communicates the first fluid compartment 65 with the second fluid compartment 67 (Figure 4). The coil spring 73 extends in compression between the inner end wall 97 of the cover 91 and the end wall 99 of the space 83 in this flow path as illustrated. As shown in Figure 5, the coil spring 73 normally predisposes the slider reel 81 to a position where the rear wall 99 clears the orifice (s) 75 and thereby does not obstruct the fluid as it flows to it. through the flow path FFP. This position can be referred to as the "fully open" position. In such position, the valve 81 is inoperative for any blocking function and the locking cylinder 35 serves as a common and effective moderator (stabilizer) against the articulation forces which cause oscillations and abnormal oscillation and lifting movements. of the front wheels without, at the same time, having any substantial effect on what is designed in suspension steering capability. As can be seen, the O-rings 85 and 87 act to seal the longitudinal hole 77 of the fluid communication through the reel 81. This, in turn, allows the end of the hole 77 adjacent to the space 89 (as opposed to that portion of the hole 77 at the other end of the reel 81 adjacent the wall 99) is used for driving by air (or other fluid) of the reel 81 to a fully closed or partially open position. In Figure 5 the arrow A indicates the air evacuation direction of the hole 77, to thereby allow the normal predisposition of the coil spring 73 to retain the spool 81 against its rear retaining wall 101 to be in its "fully open" position. As shown in Figure 6, when air or other fluid is applied to a sufficient pressure in the hole 77 and, in the direction of the arrow A, the reel 81 (including the spaces 83) is caused to move through of the intersection of the side hole 75 and the longitudinal hole 77 that prevent fluid flow through the FFP flow path as it advances. Obviously, in order for this to occur, sufficient force must be applied by air in the direction of the arrow A to overcome the predisposition of the coil spring 73. Finally, if sufficient air pressure is applied, the spool 81 will slide to the point illustrated in Figure 6, wherein preferably two spaces 83 (or only space 83 with wall 99 if desired) clears the orifice (s) 75. This position is appropriately designated the "fully closed" position that, except as designed or not designed with respect to leakage through the O-ring 85, no fluid can flow between the first fluid compartment 65 and the second fluid compartment 67. When this "fully closed" position is obtained ", the handling capacity of the suspension is fully blocked and moderation can be carried out only by means of the designed or non-designed leaks mentioned above in the valve m isma (for example by passing around the O-rings 85). A further embodiment of this invention, wherein the air pressure is only sufficient to partially close the hole 75 will be described with respect to the following Figures 9-10. Through the previous structure a valve is provided which defines three basic positions: (1) fully open, (2) partially open and (3) fully closed. In the "fully open" position (figure 5), the suspension is free to be directed or driven to the full degree of its design as determined by the adjusted drag angle "C. Only the oscillations are moderated due to the nature of the flow path FFP which is significantly less than the diameter of the container 63 for fluid. In the "partially open" (that is, "partially closed") position, sufficient interruption of the fluid flow in the FFP flow path is effected to reduce, that is to block to some extent, the directional capacity of the suspension in general, in proportion to the amount of closure of the FFP flow path performed (see figure 10 attached). In the "fully closed" position (figure 6) the direction, for all intents and purposes, is blocked completely. Then, by allowing, as mentioned above and optionally, for the designed with respect to leaks, such as through the spaces 83 and the O-ring 85 when the valve 79 is "fully closed", a measure of damping or moderation can be made even if the direction, for all intents and purposes, is completely blocked. Still further, or as yet another alternative, only one of the two cylinders 35 in the suspension (see Figure 3) need to be provided with this invention. The other can be a moderator of the prior art. Still further, but less desirable, moderators or dampers of the prior art may be provided in addition to the two valve lock cylinders 35 of this invention. In any chosen configuration, by simple evacuation (eg release of the air pressure) in the hole 77 (in the direction of the arrow A in Figure 5), the coil spring 73 automatically returns the spool 81 to the position fully open shown in Figure 5. Several controls from simple to complex, depending on the number of functions to be executed, can be designed to operate the valve 79. An exemplary embodiment is illustrated schematically in Figure 7. Here, a control is provided with several options to detect when the vehicle is placed in either a counter-gear gear mode (or any other preselected mode) and in response to the same block (totally or partially) the direction of the suspension and / or detect when The vehicle has reached a speed at which, or at a higher speed, blocking is desirable (for example 72 km / h (45 miles per hour).) And as illustrated, it is the same control has the ability to lift and lower the lifting axis. While this mode shows a combination of all three functions, it is understood that any selected control needs to have only one function. For example, in an addressable, non-liftable axle suspension, the lift mode is not present and the control can employ either or both of the detectors. An additional modulation option is also provided in Figure 7, and will be discussed with respect to Figures 9-10 below. Referring now to the features of Figure 7, there is illustrated a conventional air container 201, having an inlet 203 from a source of compressed air (for example, the compressor for the vehicle air brakes, not shown for convenience). The outlet line 205 of the container leads to a conventional air brake protection valve, schematically illustrated at 207. Commonly and in accordance with the law in certain jurisdictions, the brake protection valve 207 is provided to not allow air is removed from the brake system unless a minimum of 5.3 kg / mc 2 (75 pounds / inch) is reached in vessel 201. Conventional air control equipment is illustrated schematically in 209. This equipment includes 209 the pressure regulator 211, a manual valve 213 of two positions, and the pressure gauge 215. The equipment 209 is used to regulate the air to the air bellows in order to raise and lower the lifting shaft as mentioned above. For example, when the valve 213 is in a position, air is supplied to the air-driven bellows (springs) 17 and the air bellows 19 of the lifting shaft are evacuated, whereby the suspension is placed in its "lowered" position. "or" in contact with the road ". In the other position, the bellows 17 are evacuated and the bellows 19 are bi-directionally expanded to lift the wheels 27 out of engagement with the path to their "raised" position (according to the above mentioned patent). For convenience, a quick-release valve 217 is provided to decrease the time required to evacuate air from the bellows 17 when the wheels 27 are raised. The control that governs the blocking characteristics of this invention is generally illustrated at 219. As schematically illustrated, such control conveniently includes an electronic solenoid valve 221 positioned as illustrated to be normally closed and having a conductor 223 grounded. At least one, and optionally two, conductors 225, 225 of the detector are additionally provided. The driver 225 can be connected to a conventional detector to detect vehicle speed (e.g. from electronic components in the transmission), while the driver 227 can be connected to detect when the vehicle is placed in its mode of operation. counter-clockwise gear, such as by means of a detector connected to the counter-beam lights. In this way, pre-selected cruise and / or cruise travel speeds can be detected automatically for the blocking of the steerable wheels 27. For example, in the normal forward operation of a common or semi heavy duty truck -trailer, air pressure (usually 2 greater than 5.3 Kg / cm (75 pounds / square inch)) is provided via line 229 from container 201 through brake protection valve 207 to air equipment 209 and the lock control solenoid 221. Then the air equipment 209 can be used to manipulate the lifting shaft and provide a constant air pressure to the bellows 17 when the suspension is in its way of contact with the road. The air provided via line 231 from line 229 to solenoid 221 is stopped because the solenoid valve 221 is predisposed to be normally closed. Then, when a signal is received from either conductor 225 or 227, the spool in valve 221 is shifted to open the valve exit port and activate the lock. In this way an effective locking mechanism is obtained for the back-and-forth trip (or both) at a speed greater than a predetermined speed (eg 72 km / h (45 miles / hour)). Figure 7 further illustrates a further and unique feature, optionally incorporable to the present invention. First of all, it is clear from the foregoing description that by modulating the air pressure applied to the spool 81 in the valve 79, the amount of steering capacity or, in other words, the amount of delay of the designed in steering capability in the flow path FFP is adjustable simply by controlling the amount of closure of the flow path FFP. To effect such modulation, if desired, pressure regulator 233 can be provided. While such regulator 233 can be very sophisticated, and still computer controlled, to produce varying degrees of pressure in response to varying charge inputs, etc., on the blocking cylinders 35, the regulator 233 can also effectively be a simple preset regulator (as illustrated), this is a regulator set to provide a single, preselected simple pressure to the orifice 77 in the rod 43 of the piston.

The choice of a preset pressure is within the capabilities of one skilled in the art. Generally, it only requires the balance of the air pressure necessary to obtain the desired degree of closure of the flow path FFP by the spool 81 against the predisposition (opening force) of the coil spring 73. Figure 10 illustrates the positioning of the extreme wall 99 when this balance is achieved, to obtain a "partially open mind" position. As can be seen, by providing a preset pressure of the regulator 233 (via the arrow A) to the rear end of the reel 81, the predisposition of the coil spring 73 is sufficiently overcome to move the space 99 through the hole 75 a preselected distance, so as to by this delay sufficiently, but not to block fully, the direction. There are numerous instances where such an optional modulation feature is desirable. For example, it is clear to the skilled in the art that in most instances it may be very important to block fully during the trip in back-march mode, but during forward travel some steering capability must be left in the system (through modulation to a "partially open" position to allow steering in slow, long curves, even when the vehicle speed is above the maximum speed selected for steering lock. counter-clockwise omit regulator 233 (omission is not shown for convenience), but detection in forward mode would send 2 air line pressure (eg 8.4 Kg / cm (120 pounds / square inch)) on line 231 by means of the regulator, which would decrease the pressure to the desired amount (eg, 3.5 kg / cm (50 pounds / square inch)) to present the spool 81 in the partially open position shown in Figure 10. A technique for choosing the appropriate pressure for regulation can be described with reference to Figure 9. Such a technique includes instrumenting an exemplary vehicle with the steerable axle of desired model and particular size, such as so that you can verify exactly the direction of the axis against time. The adaptable instrumentation for such use is well known to the experienced and, of course, includes an adjustable regulator. Then the vehicle undergoes a series of maneuvers to change terrain at high speed and long curves, large radius, on the highway. The regulator's air pressure is then varied until the change in steering angle during high-speed ground maneuvering is negligible, while, at the same time, the axle (and wheels) They drive around long curves, large radius. Then the cylinders 35 on the shaft are separated and one of them is placed in a conventional press that verifies the load against bending. Then, with the pressure regulator set to the same pressure that was used to optimize performance characteristics on the highway, the cylinder is subjected to a load and bending verified. As a reference for the one skilled in the art how to carry out this invention, a load curve against deflection (deformation) is shown in Figure 9 for a common cylinder 35 which is useful in liftable axles for heavy duty trucks of the type of steerable lift axle described and illustrated in the aforementioned patent No. 5,403,031. In Figure 9 the dashed line is load and the solid line represents deformation. Then, from this example, a preset pressure is determined which can result if desired, the use of a simple preset non-adjustable regulator for all similar types of vehicles and suspensions. From the curves, the characteristics of the cylinders 35 for similar additional suspensions are established in this way, and single cylinders are selected accordingly. In order to give the experienced an additional reference to carry out this invention, rather than as a limitation, a locking cylinder 35 useful for use in a common liftable axle suspension, as described and illustrated in FIG. US Patent No. 5,403,031 mentioned above, begins with a standard shock absorber such as that manufactured by Gabriel Corporation, part No. 1TX695334, a well-known 4.13 cm (1 5/8") orifice damper. an external diameter for the dust collector of 8.25 cm (3.25 inches) and an outside diameter for the container of 6.98 cm (2.75 inches) .The container holds 1018 ce of hydraulic fluid.The shock absorber has an increased length of 60.10 cm (23.66) inches), a downsloped length of 43.59 cm (17.16 inches), and thus a path of 16.51 cm (6.50 inches) .Then this cushion is modified by providing a longitudinal hole 77 of 0.762 cm (0.30 inches) in diameter, and 2 side holes 75 0.762 cm (0.30 inches) in diameter. The outlet hole 71 and the hole 93 of the lid are substantially the same and are 0.477 cm (0.188 inches) in diameter. The following comprises its performance characteristics when it is fully open: Speed (inches / second) Damping force (LBF) 4.71 13.35 26.70 Bounce 720 950 +/- 190 1212 Compression 113 198 +/- 50 254 Such a cylinder 35, now modified, is useful in the mode in which the blocking of the counter-march and / or the blocking at highway or cruise speed is desired. Then two such cylinders 35 can be used as the cylinders 35 as shown in Figure 3 and are operated effectively by using the controls of Figure 7 as described above. Once given the above description, many other features, modifications and improvements will become apparent to the experienced technician. Such other features, modifications and improvements are therefore considered part of this invention, the scope of which will be determined by the appended claims.

It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects to which it relates. Having described the invention as above, property is claimed as contained in the following

Claims (27)

1. A locking mechanism for a wheel carrier axle suspension system, with self steering of a vehicle, the suspension system includes a wheel carrying axle, steering means for steering the wheels of the system and means for connecting the axle carrier of wheels and the steering means in travel contact relation with a vehicle frame element, characterized in that: the locking mechanism comprises a cylinder connectable to the steering means, the cylinder has a container with walls for fluid in the same , a substantial fluid within the container, a piston within the fluid container having a piston head slidable within the container and extending through the fluid container in fluid sealing engagement with the fluid walls to define a first compartment for fluid and a second compartment for fluid separated from the first compartment for fluid by the head of the piston, the piston head has a hole therein to thereby define a fluid flow path between the first and second fluid compartments; - - the locking mechanism further includes a valve associated with the orifice of the piston head for opening and closing the orifice to the fluid flow between the first and second fluid compartments, and a control for actuating the valve to its open position or closed; whereby when the orifice is substantially closed, the locking mechanism prevents any substantial steering of the wheels and when the orifice is open the wheels can be steered.

2. A locking mechanism according to claim 1, characterized in that the ease of steering of the wheels is in proportion to the extent to which the hole is opened.

3. A locking mechanism according to claim 1, characterized in that the mechanism acts as a damping device against the oscillation of the wheels when the hole is open, partially open, and closed.

4. A locking mechanism according to claim 1, characterized in that the mechanism further includes a spring located in the first fluid compartment which normally predisposes the piston head towards the second compartment for the fluid.

5. A locking mechanism in accordance with claim 4, characterized in that the piston further includes a piston rod attached to the piston head extending outwardly through the second fluid compartment beyond one end of the cylinder, piston rod has a longitudinal hole in it attached to the control and a side hole in it that intersects the longitudinal hole, the side hole is part of the fluid flow path between the second compartment for the fluid, the hole of the piston head, and the first compartment for the fluid, the valve for opening and closing the orifice of the piston head includes a valve head located movably in the longitudinal orifice with respect to the lateral orifice to interrupt or not selectively interrupting the flow of fluid between the longitudinal orifice and the side hole and to be movable to a position in the intersection between the longitudinal hole and the side hole to thereby close the flow path of the fluid between the first and second compartments for the fluid and thereby prevent any substantial steering of the wheels.

6. A locking mechanism according to claim 5, characterized in that the valve further includes a spring that normally predisposes the valve head to a position within the longitudinal hole so as not to interrupt the flow of fluid between the longitudinal orifice and the side hole and by this, normally open the flow path of the fluid between the first and second compartments.

7. A locking mechanism according to claim 6, characterized in that the control includes an actuator for selectively supplying air to the longitudinal orifice under a pressure sufficient to overcome the predisposition of the spring that normally predisposes the valve head and to move the head of the valve. the valve to a position which closes the flow path of the fluid, and to selectively remove the air under pressure to thereby allow the normal predisposition of the spring to return the valve head to a position which reopens the path of fluid flow.

8. A locking mechanism according to claim 7, characterized in that the actuator is able to control the air pressure, thereby selectively moving the valve head to a position which closes the fluid flow path either partially or completely.

9. A locking mechanism according to claim 1, characterized in that the locking mechanism includes two of the cylinders and a connection for connecting each cylinder to an opposite side of the suspension.

10. A locking mechanism according to claim 9, characterized in that the steering means of the vehicle includes a first and a second steering rod, each steering stem is located on a respective side of the vehicle and a connecting rod or Union extending between the first and second steering rods and joined in steering coupling with the rods, and wherein the locking mechanism includes means for joining one of the cylinders to a respective steering rod, such that each cylinder it can be joined to be in one direction operatively opposed to the other of the cylinders.

11. A locking mechanism according to claim 10, characterized in that the locking mechanism further includes means for joining the cylinder to the shaft.

12. A locking mechanism according to claim 1, characterized in that the locking mechanism includes a detector for detecting when the vehicle is in a counter-clockwise gear mode and an actuator for actuating the valve to a closed position in response to the detector that detects when the vehicle is in the counter-gear gear mode.

13. A locking mechanism according to claim 1, characterized in that the locking mechanism includes a detector for detecting when the vehicle reaches a predetermined speed and an actuator for actuating the valve to a closed position when the vehicle is operated at a predetermined speed or at a higher speed and to operate the valve to an open position when the vehicle is operated at a speed lower than the predetermined speed.

14. A locking mechanism according to claim 13, characterized in that the locking mechanism further includes a detector for detecting when the vehicle is in a reverse gear mode and an actuator for actuating the valve to a closed position in response to the detector that detects the vehicle when placed in the counter-gear gear mode.

15. A locking mechanism according to claim 14, characterized in that the vehicle includes electric circuits of return light of the counter-clockwise gear and the detector to detect the counter-clockwise gear mode includes a connection to connect the detector to the electric circuit of the return light.

16. A locking mechanism according to claim 15, characterized in that the vehicle includes an electronic transmission circuit capable of indicating the speed of travel of the vehicle and the detector for detecting the predetermined speed of the vehicle includes a connection to connect the detector to the circuit of electronic transmission.

17. A locking mechanism according to claim 1, characterized in that the control is capable of actuating the valve to a closed position when the wheels are in a turning position.

18. A locking mechanism according to claim 1, characterized in that the mechanism also includes a detector for detecting load inputs to the vehicle at a speed greater than a predetermined speed, and according to the amount of the load input that is incurred , activate the control to vary the closing amount of the valve in proportion to the detected load input.

19. A locking mechanism for a wheel carrier axle suspension system, for self-steering a vehicle, characterized in that it comprises a wheel carrying axle, steering means, and shock absorber means to stabilize the oscillations in the system when it is found. in motion, the locking mechanism includes means located within the shock absorber to lock the steering means.

20. A locking mechanism according to claim 19, characterized in that the damper includes a cylinder portion having therein a fluid container and a piston head thus located in the cylinder to define on either side of the piston head a fluid compartment, the piston head has a hole therein to define in a normal manner a flow path of the fluid that absorbs the shock between the compartments for the fluid, the means located inside the damper for blocking the steering means include means for selectively opening and closing the flow path of buffer fluid between the compartments for the fluid.

21. A locking mechanism according to claim 20, characterized in that the locking mechanism further includes detector means for detecting when the vehicle is in a counter-actuation drive mode and actuator means responsive to the detector means for operating the mechanism. locking to a position that closes the fluid flow path when the detector means senses the vehicle in a counter-drive mode of operation.

22. In a wheeled vehicle with frame elements having a wheel carrier axle suspension system attached to the frame member of the vehicle, the system includes a wheel carrying axle, self-steering means for steering the wheels of the system, means for attaching the system to a frame member of the vehicle and a locking mechanism for preventing the steering means from steering the wheels at selected times, the improvement is characterized in that the locking mechanism includes a cylinder attached to the steering means, the cylinder has a container with walls for the fluid therein, a fluid in the container, a piston inside the fluid container having a piston head slidable within the container and extending through the container for the fluid in coupling of sealing the fluid with the walls of the container, to define on one side or another of the piston head a respective compartment for the With a second fluid compartment, the piston head has a hole to establish a fluid flow path between the first and second compartments for the fluid; the locking mechanism further includes a valve means associated with the orifice for opening and closing the orifice to the fluid flow between the first and second compartments for the fluid, and a control means for actuating the valve means to their open and closed positions. closed; whereby when the hole is fully closed the locking mechanism prevents any substantial steering of the wheels and when the hole is opened the wheels can be steered.

23. The wheel vehicle with frame elements according to claim 22, characterized in that the locking mechanism is effective as a shock absorber against the oscillation of the wheels in any actuation or deactivation mode in which the locking mechanism is placed.

24. The wheeled vehicle with frame elements according to claim 22, characterized in that the vehicle includes a transmission having a counter-gear gear mode, and wherein the locking mechanism includes detector means for detecting when the transmission is in a counter-gear gear mode, and wherein the control means includes means for actuating the valve means to a closed position in response to the detector means sensing the vehicle in a counter-gear gear mode.

25. The wheeled vehicle with frame elements according to claim 22, characterized in that the vehicle includes means for indicating the speed of the vehicle in the direction of forward travel and wherein the locking mechanism includes detector means connected to the means of speed indicator for actuating the valve means to a closed position in response to the detector means sensing a speed greater than a predetermined amount.

26. The wheeled vehicle with frame elements according to claim 25, characterized in that the vehicle includes a transmission having a counter-clockwise gear mode and wherein the locking mechanism includes detector means for detecting when the transmission is in a counter-gear gear mode and wherein the control means include means for actuating the valve means to a closed position in response to the detector means detecting the vehicle in the counter-gear gear mode.

27. The wheel vehicle with frame elements according to claim 24 or 25, characterized in that the locking mechanism is effective as a shock absorber against the oscillation of the wheel in any actuation or deactivation mode in which the locking mechanism is placed.