FR2643961A1 - VARIABLE DAMPING SHOCK ABSORBER AND REMOTE CONTROL FOR MOTOR VEHICLES - Google Patents

Abstract

The invention relates to a shock absorber piston with remote controlled variable damping for motor vehicles. It comprises in combination a piston head 10 connected to a piston rod 14 in which there is an internal cavity 64, a motor 86 disposed in this cavity and comprising a control 94, a fluid passage to obtain a flow during the movement of the piston head, a valve 34 regulating the flow of the fluid, a switch for rotating the motor and an electrical circuit for providing a control voltage to the motor. Application to the manufacture of improved and controlled shock absorption systems.

Description

The present invention relates to dampers such as shock absorbers

  shock or damping bars for vehicles. More particularly, this invention relates to shock absorbers and damping bars in which the damping force provided by a flow

  of fluid is adjustable either manually or automatically

  in response to speed, load or acceleration

  of the vehicle or the conditions of the road.

  In a typical automotive suspension system, the shock forces experienced by the suspension system are "absorbed" by a combination of a spring and a shock absorber. The shock absorber is constituted by a rod and a piston mounted within a cylinder and the spring urges the rod to extend outwardly from the outer cylinder. Vibratory shock energy inside the suspension system is "absorbed" and stored by compressing and extending the spring. This energy in turn is dissipated by

  the shock absorber or bar during the damping action

  resulting from a valve piston moving in a direction

  and-comes inside the cylinder containing the hydraulic fluid. The damping action converts the vibratory energy into heat that the wall of the cylinder conducts and

  transfers to the surrounding atmosphere.

  A typical shock absorber has a cavity for the oil in the cylinder on either side of the piston rod inside the cylinder. The action of the shock absorber (when the spring and the piston rod are compressed in response to contact of the wheel with the road, pushes the oil from one cavity to another and the rebound is then damped by the resistance of the oil flow in the reverse direction as the piston is pushed towards the extension by the force of

  Spring rebound. "The valve effect in the

  of the piston and between the cavities thus provides the appropriate resistance to the flow of fluid between the

two cavities.

  By way of example, various types of shut-off valves and variable flow constrictors have been designed to allow fluid flow in compression (from the cavity below the piston through the piston head or around it and towards the cavity of the outer cylinder reservoir) more freely, ie with less resistance than in the case of the extension (from the external reservoir cavity and from the cavity surrounding the rod towards the cavity below the piston). Such stop valves thus provide greater damping when desired, during extension (rebound), rather than during compression shock absorption when the shock absorber should compress relatively freely for minimize the transfer

  energy to the occupants of the vehicle.

  Improvements in this basic system have provided varying damping characteristics for varying road conditions or vehicle speed, load or acceleration. When the vehicle is moving faster, for example, the damping must often be increased to counteract the increased forces that tend to reduce the contact between the tire and the tire.

road surface.

  Such a variable damping shock absorber is illustrated in U.S. Patent No. 4,527,676 issued July 9, 1985. This patent discloses a shock absorber having variable damping achieved by a motor rotating a valve. four-way stop in the shock absorber. The motor is either a stepper motor with four steps first, a step for each of the possible orientations of a four-way stop valve, or secondly a motor driven by feedback with four arcuate electrical wires in contact with brushes to determine the exact position of the motor control. Both types of engines are relatively complicated and expensive, in the same way as the four-way valve associated with each of them. For example, the device of this patent requires a four-wire harness. This gives a harness

  expensive and complicated vehicle.

  Another problem with the device of this patent is its relatively complicated and expensive engine mechanism. In the embodiment using a four-way stepper motor, these motors are inherently complicated and expensive because they must be designed to stop at each of the four points, with an appropriate electronic device to maintain control. the position of the stepper motor at

  each of its four stop positions.

  In the embodiment of this patent using a feedback-controlled motor, the motor provides a four-way pitch via a feedback control circuit that receives feedback from mechanical contactors. sweeping electrical contacts. These contactors and contacts wear out and corrode over time, causing a loss of electrical contact. The variable damping mechanism of this patent can thus be completely out of order well before

  that the other components fail in turn.

  One of the aims of the present invention is to develop a variable damper for remote controlled vehicle, relatively inexpensive and however more reliable. Another object is to provide a usable damper with a car wiring harness system that only needs two wires used by the variable damping shock absorbers. Another object is to provide a remote controlled variable damper which does not use brush and contact mechanisms for electrically controlling the positioning of the valve member in the damper. Another object of the present invention is to provide a damper having a reliable electric motor that moves safely and quickly on demand

  the valve element between two positions.

  Another object is to provide a variable damper with two damping levels, one of which is optimum for moderate cruising speeds of one vehicle, the other of which is optimal for rapid acceleration and deceleration, high speeds or for a difficult terrain. Another object is to provide a damper which comprises a reliable two-way valve

  easily switchable and located inside the shock absorber

  shock. Yet another object is to provide as an embodiment a valve mechanism which converts the rotary motion of a rotary control spindle into a linear motion of a slide valve to slidably open and close flow outlets damping fluid. Another object of the invention is to alternatively use the rotary movement

  to drive a rotary valve.

  Another variant of the present invention is to provide a variable damper in which a damping level is much greater and preferably

  significantly greater than a second level of depreciation

  even for relatively low road impacts.

  Other objects and advantages of this

  invention will become more clearly apparent in the description

  following which is made in the light of the drawings in which:

  FIG. 1 is a view in transverse section

  vertical dirty of the first preferred piston rod having an internal dosing pin shown in the open upper position;

  FIG. 2 is a view in transverse section

  vertical dirty by the center of the motor housing of the first preferred embodiment; - Figure 3 is an end view from below. the motor housing of the first preferred embodiment; FIG. 4 is a side elevational view of the control head of the metering pin of the first embodiment of the invention, a portion of this view being exploded to reveal internal details of the control head; Figure 5 is a top end view of the control head of Figure 4; Figure 6 is a bottom end view of the control head of Figure 4;

  FIG. 7 is a view in transverse section

  vertical dirty of the dosing pin of the first embodiment of the invention;

  FIG. 8 is a view in trans section

  the counterpart of the metering pin of Fig. 7 taken along section line 8-8 of Fig. 7;

  FIG. 9 is a view in transverse section

  vertical dirty of the first preferred piston rod, the internal dosing pin being in the closed lower position;

  FIG. 10 is a view in transverse section

  vertical dirty of a piston stop of the first embodiment; Fig. 11 is a top end view of the piston stop of the first embodiment; Fig. 12 is a side elevational view of a compression stop pin of the first embodiment; Fig. 13 is an end elevation view of the compression stop pin of the first embodiment; Figure 14 is a partially cross-sectional side elevational view of a control screw of the first embodiment; Fig. 15 is a view of the motor from the end of the pin along section line 15-15 in Fig. 1; Fig. 16 is a top end view of the control screw of the first embodiment; Fig. 17 is a vertical cross-sectional view of the second preferred piston rod having a bypass tube and a rotary valve in the open position; Fig. 18 is a plan view of the underside of a spacer having rotational stops; - Figure 19 is a vertical sectional view

  of the spacer along the cut line 19-

  19 of Figure 18; Fig. 20 is a plan view of the upper surface of the spacer; Figure 21 is an elevational view of a valve stop; Fig. 22 is a plan view of the valve stop having a rotational limitation arm;

  FIG. 23 is a view in transverse section

  vertically draining the second preferred piston rod, the rotary valve being in the closed position; Fig. 24 is an elevational view of a rotary valve member; Figure 25 is another elevational view taken at 90 'to the view of the rotary valve of Figure 24; Fig. 26 is a bottom view of the rotary valve member; Figure 27 is a top end view of the piston stop of the second preferred piston rod; Fig. 28 is a sectional elevation view of the piston stop of Fig. 27, along section line 28; Fig. 29 is a top end view of the motor housing of the second preferred piston rod; FIG. 30 is a sectional elevational view of the engine casing of FIG. 29 along section line 30-30; Figure 31 is a bottom elevational view of the motor housing of Figure 29; Fig. 32 is a vertical cross-sectional view of the second preferred piston rod showing the internal components in the piston rod in the area of a shock absorber; Fig. 33 is an upper cross-sectional view, along section line 33-33 of Fig. 32, of the stress release anchor and the wire strain relief member of the preferred shock absorber; Fig. 34 is a longitudinal bottom view of the wire stress releasing element; Fig. 35 is a side elevational view of the wire stress release member, the passage for the inner wire being shown by dashed lines; Fig. 36 is an upper plan view of the stress release anchor of the preferred embodiments; Fig. 37 is a block diagram of a motor control circuit for the shock absorber utilizing the piston rod assemblies of Figs. 1 and 17; Figs. 38a and 38b are electrical waveform diagrams of the motor current of the shock absorber utilizing the piston rod of Figs. 1 and 17; Fig. 39 is an electrical schematic diagram of a motor control circuit for the shock absorber utilizing the piston rod of Figs. 1 and 17; FIG. 40 is an electrical block diagram of part of the circuit of FIG. 39; - Figures 41, 42 and 43 are schematic electrical diagrams of another embodiment of a motor control circuit for the shock absorber using the piston rod of Figures 1 and 17; and Figures 44 and 45 are schematic electrical diagrams of another embodiment of a motor control circuit for the shock absorber utilizing the piston rod of Figures 1 and 17; FIG. 46 is a sectional side view

  cross-section of a third embodiment of absorbing

  shock absorber of the present invention; and

  FIG. 47 is a view in transverse section

  dirty along the section line 47-47 of Fig. 46 showing the inner cylinder head in the third

  embodiment of the present invention.

  This description uses various terms

  orientation in the space such as "vertical", "upper" and "lower". These terms are only used for

  facilitate the description of the location and movement

  relative in one orientation of the preferred embodiment. These terms do not constitute limitations of all possible orientations of the invention or its components in any given application. Similarly,

  in the description and in the claims, the term

  "vehicle absorber" is considered to include shock absorbers, MacPherson bars and other dampers, particularly those for damping the

movement of vehicles.

  There are three preferred embodiments.

  The first generally bears the reference number and is shown in FIGS. 1 to 16. The second, generally designated by the reference numeral 12, is in FIGS. 17 to 36. The third embodiment, so designated 450, is illustrated in FIGS. 46 and 47. The differences between the first and second embodiments 10 and 12 are in the internal construction of their respective piston rods 14, 16. The third embodiment of FIG. embodiment 450 has other such differences as well as differences in the surrounding structure of the absorber

of choc.

  Referring to the first embodiment of the piston rod 14 shown in FIG. 1, there is shown a piston rod 14 having an upper cylindrical rod 18 attached to a central piston stop approximately

  cylindrical 20 which in turn is attached to a piston 21.

  The piston stop 20 has diametrically opposed and radially outwardly extending flow passages 24, 26; and the piston 21 also has somewhat narrower but diametrically opposite flow passages 28, 30 extending radially outwardly. The piston 21 further comprises lower flow passages generally designated by reference numeral 32, at the lower end of the piston 21. A valve structure, generally designated by reference numeral 34, within the piston rod 14 provides selective fluid communication of the lower flow passages 32 with opposite piston passages 28, 30 and opposite passages

piston stop 24, 26.

  For example, the fluid entering through the lower flow passages 32 may be selectively directed to either the piston flow passages 28, 30, or to the combination of the piston stop passages 24, 26 and the flow passages. In addition, the selection of the two groups of flow passages, in comparison with the selection of a single group, produces an enlarged flow path, - easier flow and

  less damping by the piston and rod assembly 14.

  As shown in FIG. 10, the piston stop has an internal passage 33 extending over its upper axial length. The inner passage 33 penetrates through the axial center of an upper cylinder portion 36 abutting a plane edge center stop 38. An externally threaded lower portion 48 extends axially downwardly from the edge stop 38. The upper cylinder portion 36 firstly has an externally threaded section 42 abutting the edge stop 38

  and secondly an inner threaded upper section-

  44 on the end of the upper cylinder

36 opposed to the stoppage 38.

  As shown in Figure 11, the edge stop

  plan 38 has an outer periphery 46 substantially circumferential

  lar. As shown in FIG. 10, the opposed piston stop flow passages 24, 26 extend from below the upper planar surface of the edge stop 38 and communicate with the axial stopping passage 33. piston. The upper portion 48 of the axial passage 33 enters the axial center of the edge stop 38 and the upper cylinder portion 36 and has a diameter substantially greater than the diameter of the lower portion 50 of the axial passage 33. The junction passages 48 and 50 constitute a truncated conical seat 52 on the lower edge of the junction of the opposite flow passages 24, 26 and the upper axial passage 33. The conical surface of the seat 52 forms an angle of 45 'to at

  the axis of the axial passage 33 and the axis of the flow passages

24, 26 coaxial opposites.

  As shown in FIG. 1, the upper piston rod 18 has a threaded lower end 54 internally and threadably secured to an externally threaded section 42 of the cylinder portion 36 of the upper piston stop of FIG. In turn, as shown in FIG. 1, the piston 21 has an internally threaded upper section 56 also called the neck, which is screwed onto the threaded lower portion 40.

  externally of the piston stop 20.

  The piston 21 has a radially and externally spaced skirt 39 extending axially downward from the internally threaded section 56. Opposite coaxial piston passages 28, 30 extend radially outwardly from the end

  bottom of the threaded section 56. A passage of

  Piston flow passage 60 communicates with a radially narrower passage 77 in piston end 58. An axially extending collar 66 surrounds the passageway. narrower lower end 77 and terminates at its lower end in a planar and circular valve seat 81 which communicates with a wider underpass 64. The lower end 68 of the wider lower portion 64 of the flow passage of piston has a flange 70 projecting axially, spaced radially outwardly. The rim 70 has an internal diameter substantially equal to the outer diameter of a perforated retaining plate 73 fixed by the rim 70. As shown in FIG. 1, the perforated plate 73 has axial openings, generally designated by the number 32. , which provide fluid communication between the piston flow passage 64 and a volume beyond the end of the piston 21 in front of the piston rod 18 and the piston stop 20. The structure Valve 34 thus has a rebound valve cap 79 and a rebound valve cap spring 75 retained between the axially extending collar 66 on the one hand and

  the rim 70 and the plate 73 on the other hand.

  The bounce valve cap 79 has an upper section 74 of conical shape. The spring 75 pushes the upper section 74 upwardly away from the plate 73. The upper section 74 has a flat lip 76 extending radially outwardly and toward the outermost edge 78 of the upper section 74 The flat lip 76 bounces axially on the valve seat 81. The seat 81 thus provides a stop for the movement

  axial upward of the upper section 74.

  The center of the upper section 74 has a cap swath 80. This passage 80 establishes a fluid communication between the upper passage 60 and the wider lower passage 64 in the piston 21. The valve passage 80 thus provides a communication

  restricted fluid between the axial openings

  32 of the plate 73 and the piston stop passages 24, 26 and the piston passages 28, 30. With regard to the upper part of the piston rod 18, it is seen that the upper portion threaded at the The inner end 44 of the piston stop 20 is screwed with the lowest threaded outer end 82 of the motor housing 84 retained within the upper piston rod cylinder 18. The housing 84 and the upper piston rod 18 thus cooperatively retain a DC motor 86, a gear box housing 84, a spacer member 90, a thrust washer 92, and a control screw 94. the inside of the upper piston rod 18. The DC motor 86 and the gear train housing 88 are manufactured assembled as an independent unit and are fixedly retained within the casing 84. The Motor 86 and gear case 88 are attached within housing 84 to prevent relative rotation between motor 86 and housing 84. Fastening is accomplished by mechanical keying (not shown) between motor housing 84 and

  gearbox 88 or alternatively by the application of

  adhesion bonding material at the interface between

  the motor housing 84 and the gear housing 88.

  Two wires, generally designated 96, pass through a wire passage 98 in the upper portion of the piston rod 18 above the DC motor 86. The wires 96 are connected to the terminals of the upper end of the current motor. continuous to supply current from an external source via the wire passage 8 to the current motor

continuous 86.

  Referring now to FIG. 2, it will be seen that the housing 84 has four coaxial passages 100, 102, 104, 106. The uppermost passage is a zone 100 for retaining the motor and the gear train which is close to the narrower intermediate zone 102 which, in turn, approaches the even narrower passage 104 for guiding the control screw, which in turn is adjacent to a passage

  rectangular sliding spindle 106.

  The housing 84 also has a seal groove 108 which penetrates through its outer periphery 110. The portion of the outer periphery 110 of the housing on each side of the groove 108 has an external diameter slightly less than the internal diameter of the piston rod upper 18. By means of a gasket 112 in the groove 108, as shown in FIG. 1, the housing 84 thus slides easily in a sealing manner in the upper piston rod 18 during assembly or away from it

  piston rod 18 for repairs if neces-

  sary. Referring also to Figure 1, a gear spindle 114 extends downwardly from the gear train: first, through the cutter-shaped carrier 115 of the gear housing; secondly thereafter, through the stop washer 92 abutting the lower side of the gear housing holder 115; and thirdly in the pin passage 116 in the control screw 94, illustrated in FIGS. 14 and 16. The thrust washer 92, the holder 115 and the spacer member 90 are slidably secured within the the zone 102 for retaining the gear of the motor housing 84. Consequently, axial loads produced by the operation of the control screw 94 or by unbalanced hydraulic forces acting on the flange 120 of the control screw 94 are transmitted by the washer 92 and spacing member into (i) the gearbox holder 115 and (ii) the gearbox 88 rather than the motor spindle 114 into the gears located therein. in the

casing 88.

  In Fig. 14, the control screw 94 comprises: firstly an upper head 118 with the slot passage 116 of the slot type penetrating into the head

  118 along the axis of, secondly, a cylindrical flange

  than intermediate 120, with a radial offset therefrom, extending axially downwardly from the head 118; and thirdly, a control end 122 threaded externally with a dosing spindle extending axially downwardly from the rim 120. The head 118 is limited at its upper end by a cylindrical vertical wall 119 terminating in a shoulder 124 radially protruding towards outside. The shoulder 124 thus extends radially outwards to form

  a circular boss 125 extending generally axially

  is lying. The shoulder 124 and the boss 125 provide axial support for the lower surface and cooperate with

  this one on the thrust washer 92.

  In Fig. 15, gear spindle 114 has an axis of rotation which coincides with axis A of DC motor 86 and gear housing 88. Spindle 114 comprises: first, a substantially cylindrical surface; extending axially 121 spaced radially from the axis of rotation; and secondly, a flattened pin surface 117 extending axially on the lower dimension of the pin surface 121. As shown in FIGS. 14 and 16, the width of the slot 116 of the screw head 118 is slightly larger than the cross-sectional dimension w 'of the spindle 114, shown in FIG. 15. The flattened surface 117 corresponds to a flattened corresponding surface of the slot 116 and transmits the twisting force of the spindle 114 to the spindle

order 94.

  In FIG. 1, the cylindrical rim 120 of the control screw 94 is retained in an axially rotational position by the thrust washer 92 and the

  control screw passage 104. In this way, the former

  threaded tremity 122 of the screw 94 can threadingly contact the internally threaded passage 130 in a reciprocal manner and rotate relative thereto, in the slide 126 of

  dosing spindle, as shown in Figures 4 to 6.

  In Fig. 3, the slide passage 106 of the metering spindle of the motor housing 84 has a square periphery in cross-section. In FIGS. 4 and 5, the metering pin slide 126 has an upper outer periphery 128 which is slightly smaller but also square in cross-section, so as to be able to slide axially in the slide passage 106. This prevents any relative angular rotation between the slide 126 of dosing spindle and the housing of

motor 84 of FIG.

  In Fig. 1, when the control screw 94 is held in position in the control screw passage 104, the rotation of the control screw 94 in one direction drives the slider 126 axially and outwardly of the slider passage 106 The rotation of the control screw 94 in the opposite direction places the slide 126 recessed axially and within the

slide passage 106.

  In FIG. 4, the slider 126 also has an externally threaded lower end 132. This lower end 132 comprises threads that can be screwed, as shown in FIG. 1, onto an internally threaded upper end 134 of the

  metering pin 136 as shown in FIGS. 7 and 8.

  In Fig. 7, the metering pin 136 has a cylindrical intermediate section 138 extending downward from the threaded upper end 134 and terminating at its lower end in an outer shoulder 142. A cylindrical pin more narrow passage 140 extends downwardly from the shoulder 142. A passage 121 extends over the entire axial length of the pin 140. The passage comprises: firstly, an enlarged upper portion extending substantially over any the axial length of the intermediate section 138; second, a narrower bottom portion extending substantially the entire axial length of the control pin 140; and third, an inner neck 150 extending radially inwardly, intermediate and adjacent the upper and lower portions 138, 140. The outer conical shoulder 142 provides a truncated conical peripheral surface 142 at an angle of 45 to the The axis of the regulating spindle section 140. As shown in FIG. 9, the conical circumferential surface 142 co-operates, in sealing contact, with a seat 52 at a corresponding angle in the axial stopping passage. piston

  33, also shown in FIG.

  In Fig. 1 again, a compression valve pin 156 slidably penetrates

  over the axial length of the metering pin passage 151.

  As shown in FIG. 12, the valve pin 156 has a flanged top end 159, a tapered end

  160 and a central section approximately cylindrical

  162 between the two ends 158, 160. The central portion 162 has a middle section 164 of a somewhat narrow cross-section to reduce the potential to resist the axial movement of the pin 156 within the pin cylinder 140, as shown in

figure 1.

  In Fig. 1 again, the flanged upper end 159 of the valve spindle 156 is retained within the inner upper axial passage 154 of the dosing spindle 110. A spring 166 of the spindle of the valve pushes toward the flanged end 159 of the valve spindle 156 so that it abuts against the internal shoulder or neck 150 in the upper passage 154 of the metering spindle 136. The radial outer periphery of the spigot end flange 159 is slightly smaller than the inner diameter of axial passage 154, so that flanged end 159 can slide

axially in the passage 154.

  The valve spindle spring 166 also has an outer diameter a little smaller than the inner diameter of the passageway 154. The spring 166 has an upper end (not shown) abutting a radially inwardly extending shoulder 168, such as shown in FIG. 4, in the internal passage 130 of the slider 126 which is also shown in FIG. 1. The spring 166 has a lower end 170 abutting against the upper radial surface of the flange 159 of the compression valve spindle 156, by pushing the flanged end 158 so that it abuts the shoulder 150 of the spindle of

dosage 136.

  Again in Figures 7 and 8, the intermediate section 138 of the metering pin 136 has passages

  intersecting transverse flow streams 144, 146

  The passageways 144, 146 intersect within the upper passage portion 154 in the control pin 140, resulting in fluid escape for the portion of the control pin 140. 154. The escape of the cavity 154 through the passages 144 and 146 facilitates

  the flow of fluid to cavity 154 and out of that

  ci, which adapts to the change of the volume in this cavity since the end portion 158 of the valve pin 156 moves back and forth to the cavity 154 and

out of it.

  As shown in FIG. 1, the central cylindrical section 162 of the valve spindle 156 is slightly longer than the cylindrical control spindle 140. Thus, as shown in FIG. 9, the conical end of the valve spindle 156 extends down to

  through the passage 80 of the rebound valve cap

  79 when: (i) the conical surface 142 of the metering spindle abuts the conical seat 52 in the plunger stop 20, and (ii) the upper flange end 159 of the valve metering spindle 136 as against the inner neck 150 in the metering spindle 136. As shown in FIG. 1, however, the tapered end 160 of the valve spindle 156 barely penetrates the rebound valve passage 80.

  when: (i) the internal threaded upper end

  134 of the metering spindle 136 is retracted from the tapered neck 52 as far as possible, and (ii) the lower surface of the flange 159 of the valve spindle 156 abuts against the inner neck 150 in the metering spindle. 136. In the preferred embodiment of Figures 1 and 9, the metering pin 136 and the compression valve pin 156 are selectively placed in the axial piston stopping passage 33 by the selective actuation of the motor 86. supplying the motor to rotate the gear control pin 114 pushes the external threads on the control end 122 of the control screw 94 to rotate inside

  internal non-rotating threads 130 of the slide 126.

  Since the control screw 94 is retained at the same axial location with respect to the motor housing 84 and the piston rod 14, the rotating threads of the control end 122 push the slide 126 and the metering pin 136 with the spindle. compression valve 156 to move axially in the metering pin slider passage 106 of the motor housing 84. Depending on the orientation of the threads, the rotation of the driven gear pin 114 in a direction drives the slider 126 and the metering pin of the assembly 136 in the axial direction, and the rotation of the pin 114 in the opposite direction drives the slider 126 and the metering pin of the assembly 136 in the opposite axial direction. In operation, during the compression stroke of the piston 21, the fluid flows: (i) upwardly through the lower flow passages 32 of the piston plate 73; (ii) to the piston cavity 64; (iii) through the rebound valve passage; (iv) in the passage 60 of the piston; (v) out of the piston 21 through the passages 28, 30; and (vi) in the bouncing chamber (not shown in Figures 1 or 9). With the metering pin 136 being retracted upward as shown in FIG. 1 to move the inclined periphery 142 away from the pin 136 of the inclined seat 52 of the piston stop 20, the fluid also flows: (i) to the high through the axial passage 51 limited by the outer surface of the control pin 140 and the inner surface of the lower portion 50 of the axial passage 48 in the piston stop 20; and (ii) out of the piston stop passages 24 and 26. In addition, if the fluid pressure passing up through the compression valve passage 80 is large enough to overcome the downward force of the spring With the compression pin 166 against the compression pin 156, the force of the fluid pushes the conical end 160 of the compression valve pin 156 toward the pin 140 of the metering pin 136, away from the valve passage. This upward movement of the compression valve 156 away from the valve passage 80 allows a larger fluid flow through the valve passage 80 due to the reduced blockage caused by the conical end 160. The compression valve pin 156 thus serves to reduce the throttling of the fluid and its damping as the piston rod assembly 10 moves downward during the stroke portion.

  compression of the stroke of the shock absorber.

  When, as shown in FIG. 9, the metering pin 136 is pushed down into the axial passage 48 of the piston stop 20 to abut the inclined seat 52, the inclined peripheral portion 142 of the dosing spindle the upper part of the passage 50 and the passages 24, 26 to eliminate any fluid communication with the lower part of the axial passage 50. In this downward sealing position, the end portion 153 of the metering pin cylinder 140 is spaced narrowly above the rebound valve passage 80 and the valve pin 156 enters the passage 80 to further restrict the flow of the fluid

through passage 80.

  In operation, during rebound or extension of the shock absorber, the fluid flows to the piston flow passages 28, 30. The metering pin 136 is in the "up" or "up" position. open "(spaced from the inclined seat 52), the fluid also flows inwardly through the passages 24, 26. The fluid then flows down through the rebound valve cap passage 80 into a The pressure is not blocked by the compression valve pin 156 and the metering pin 136. If the extension forces are large, the fluid pressure against the rebound valve cap 79 forces the valve 79 to move downward against the opposing force of the valve spring 75. The fluid then flows past the gap created between the valve cap 79 and the rebound valve seat 81 and then to and through the flow passages

lower 32.

  In FIGS. 17 and 23, the form of embodiment

  The most preferred alternate alternation according to the invention does not use the relative axial movement between a metering spindle and stopping flow passages 24, 26 to modify

  fluid flow and damping characteristics

  1 and 9. Instead, in the embodiment of FIGS. 17 and 23, the gear control spindle 239 rotates an inner rotary valve 172 extending axially downwardly from a control rod 132 for modifying the flow path of the fluid and consequently the damping forces. The rotary valve 172 is shown in detail in FIGS. 24 to 26. The arms 176 extend axially downward from a cylindrical body section 177 of the valve 172. The pins 176 are in one piece with, and extend from the diametrically opposed sides of the body portion 177 and are joined on their inner extension by the arcuate section 178. The arcuate outer peripheral surfaces 179 of the legs 176 are concentric and coincide with the cylindrical surface 180 of the section. which outer surface is interrupted in part by a slot 181. External surfaces 179 and 177 of the rotary valve 172 rotatably cooperate, as shown in FIG. 17, with the internal cylindrical surface of the bore 184 of the stop. 185. The branches 176 control the radial fluid flow paths 186 and 187 between a total flow condition and a

  almost no flow condition.

  The total flow condition occurs when the valve 172 is rotated so that the axis A of the radial flow paths 186, 187 is parallel to the axis B of the arcuate surface 178 of the valve 172. The condition of Almost zero flow occurs when, as shown in Fig. 23, the valve 172 is rotated so that the above axes A, B are perpendicular to each other, resulting in blockage of the flow passages 186 and

  187 by the arcuate surface 179 of the branches 176.

  A spring loaded compression valve 190 is biased toward the retaining cap 196 within bore 189 of the piston stop 185. The orifice valve 190 has a valve spring 191 extending to the top from a radially outwardly extending flange seat 192 formed on the perforated port valve 190. The lower end of the valve spring 191 abuts and urges the port valve 190 downwardly. in the lower axial passage 64

piston stop 185.

  As shown in FIG. 17, the orifice valve 190 is thus urged to contact the upper end of a retaining cap 196 of the orifice valve. The cap 196 has a central flow throttle passage 198 and a radially downwardly extending flange 200 whose inner diameter is only slightly larger than the outer diameter of an axial branch tube 194 which extends down to

  through the lower axial piston passage 64. The former

  lowest end of the bypass tube 194 has a radially extending shoulder 201 and an axially projecting cylinder end 202 extending downwardly to

  from the lowest part of the shoulder 201.

  The cylinder end 202 extends down through a central hole 205 in the rebound valve retaining plate 173. The shoulder 207 of the bypass tube thus abuts the upper surface of the retaining plate 173 and an axial bypass flow passage 204 extending through the bypass tube 194 provides a fluid communication between the tip end. lower of the piston 22 and the orifice valve of

compression 190.

  A rebound valve spring 206 surrounds the lower end of the axial bypass tube 194. The lower end of the spring 206 abuts against the upper surface of the valve retainer plate 173 and the upper end of the spring 206 abuts against the

  bottom surface of the bouncing valve cap

  208. The cap 208 has a central port 210 slidably receiving the bypass tube 194. The spring 206 urges the upper surface of the cap of the rebound valve 208 to abut against the lower surface 81 of the projection 66 of the seat. of the valve

  rebound in the axial passage 64.

  As shown in Figs. 18 to 20, a spacer 212 having a cylindrical wall surface 211 and a flattened wall portion 213 interrupting the surface 211 is, as shown in Fig. 17, within the motor housing 218 so as to abut and support the shoulder 219 of the gear case. The end surface 215 on the spacer 212 abuts against the shoulder surface 219 on the gear housing 237. The opposite end surface 217 of the spacer 212 is spaced axially and toward the bottom of the lower end wall surface of the motor and gear housing 237. As shown in FIG. 18, the cushions 222 in the vicinity of the stop faces 209 of the spacer 212 serve as resilient contacts for the arm 203 of the limit rotary arm 228 of the valve stop 223 shown in Fig. 22. As shown in Figs. 17 and 22, a valve stop 223 is symmetrical about the axis 225. The cross-sectional configuration a central bore 226 in the abutment 223 resembles that of the motor spindle 239 as shown in FIG. 17. The spindle 239 is slightly smaller in cross section than the bore 226 and thus penetrates

  with sliding in the axis of the bore 226.

  As shown in Figure 17, a washer of

  stop 224 is retained within a semi-cavity

  circular 207 in the spacer 212.

  In Figure 18, the space element cavity

  207 has a plane bearing surface 217 spaced axially inward from and parallel to the end surface 215. As shown in FIG. 17, the thrust washer 224 surrounds the motor spindle 239 and separates the surface 229 and the spacer surface 217 for providing an anti-friction element between the two surfaces 229 and 217. The driven spindle 239 extending from the gear train is retained partially at the same time. inside

  of the housing 237 and has a cross-section essential-

  The spindle 239 extends outwardly and downwardly relative to the gear box 239 through the bore, corresponding to that of the center bore 226 of the valve stop 223 of FIG. 226

  with snug fit in valve stop 223.

  Pin 239 thus partially engages the axially extending transverse slot and the counterbore 231 of spacer 212, as shown in FIGS. 17 and 19. Valve stop 223 in cavity 207 of FIG. the spacer 212 rotates with and is driven by the pin 239 in the same manner as the control rod 232 driven by the rotation of the current motor

continuous 86.

  In operation, the rotational force of the motor 86 continues until the radial arm 203 of the valve stop 223 contacts one of the elastomeric pads 222. At the moment of contact between the elastic cushion 222 and the arm 203 , the rotational inertia of the motor 86 is gradually absorbed by the resistance associated with the elastomeric elastic cushion 222. The shock and impact that would otherwise occur by the instantaneous stopping of the angular speed of the motor would induce extremely high stresses and cause a physical damage

  to the gear train. This, in turn, would greatly diminish

  the effective longevity of the engine gears. The electrical circuit associated with the control of the motor 86 is such that the resistance to rotation experienced by the rotor as the cushions 222 contact the arm 223 is detected and the supply of electrical power to the motor is interrupted, leaving the rotary valve 172 in a preselected angular position relative to the radial flow paths 186 and 187 of the stop of

piston 185.

  The spacing element 212 and the motor 86 are cylindrical with a single axially extending flattened surface portion such as that shown as the flattened surface 213 for the spacing member.

  212 of Figures 18 and 19. In Figures 29 to 31 which

  the engine housing 218, the housing 218 has an inner top wall 267 which is cylindrical in cross-section and slightly larger in diameter than the outer diameter of the motor 86 and the gear housing 237, allowing adjustment sliding of the motor 86 and the gearbox 237 within the motor housing 218. A radially inward and downwardly inclined surface 268 is located between the fully cylindrical surface 267 and a cylindrical surface 269 extending axially and partially

  flattened. As shown in Figure 17, the space element

  212, the motor 86 and the gear housing 237 are axially and slidably received within the two-piece engine housing 218. The inner and outer close flattened surfaces of the engine housing 218, the spacing 212 and the motor gearbox 237 prevent relative angular movement between the three components: the motor housing 218, the element

spacing 212 and the casing 237.

  As shown in FIGS. 27 and 28, the piston stop 185 has two opposite lugs 270 extending axially upward and protruding a distance beyond the otherwise horizontal end surface 271 of the Piston stopper 185. The lugs 270 each have flat surfaces extending axially and diametrically opposite. As shown in FIGS. 30 and 31, a projecting lower boss 273 on the motor housing 218 has axially extending and diametrically opposed flats 282. The boss with the flats 292, when assembled with the piston stop 185 as shown in FIG. 17, is slidably received between the projecting lugs 270 of the piston stop 185. In this manner and as shown in FIG. 17, the torsional reaction forces from the operating motor 86 and the control rod 232 and the rotary valve 172 are transmitted through the screw contact of the piston stop 185 in the piston rod. 16. The slit 231 of the control rod 232 has an axial depth which prevents contact with the bottom of the lower end portion of the motor spindle 239 within the bottom of the slot 231. This eliminates any axial load of the

  motor spindle 239 and the associated gear train.

  A middle section 235 of the control rod 232 extends axially downwardly through the bearing bore 242 of a sleeve 243 integrally with the tail end 236. An elastomeric sealing member 241 sealingly surrounds the cylindrical middle section 235 of the control rod 232 and sealingly contacts the surface 183 of the axial passage of the piston stop 185. This sealing contact prevents fluid leakage axially upwardly at through the axial bore of

the piston stop 185.

  The tail end 236 penetrates with sliding

  in axial direction 181 in the upper end of the rotary valve 172 as shown in FIG. 17. The axial movement of the valve 172 is rotatably restricted within the bore 184 of the piston stop 185 by the lower annular surface of the sleeve 243 and a shoulder 188. The shoulder 188 extends radially inwardly from the cylindrical bore 184 of

  the piston stop 185 abutting against the inside surface

  The axial slot 181 of the valve 172 has an axial length sufficient to prevent the axially projecting tail end 236

contact the bottom of the slot 181.

  Again in FIG. 17, during the compression stroke, the fluid in the second embodiment flows: (i) into the open bottom end of the bypass tube 194; and (ii) if the rotary valve 172 is in the "open" position as shown in Fig. 17, (a) through the central flow passage 198 of the retaining cap 196, (b) through the ports of the compression port valve 190, (c) through the shoulder bore 276 of the piston stop 185, (d) in the arcuate passage formed by the branches 176 of the rotary valve 172 and (e) radially to the outside the radial flow passages 186, 187 of the piston stop 185. Of course, the latter flow paths 186, 187 are closed when the rotary valve 172 is closed.

  turned to the "closed" position as in figure 23.

  During the extension of the embodiment of Fig. 17, the rotary valve 172 being "open", the fluid flows (i) into the stop passages 186, 187; (ii) downwardly through the orifices of the seated compression valve 190; (iii) through the central flow passage 198 of the retaining cap 196; and (iv) out of the bypass flow passage 204. Additional fluid flows through a parallel passage of the valve zone surrounding the bypass tube 194. This fluid flows through the parallel path to the flow passages. radial flow 28, 30 of the piston 22 and downwardly through the piston passage 77. At a predetermined speed of the

  piston, the hydraulic pressure against the upper surface

  The bounce valve cap 208 urges the valve cap 208 down against the resistance force of the spring 206. The fluid then flows through the open valve and out of the flow passages.

lower 32.

  Closing the rotary valve 172 as

  shown in Figure 23 during the expansion stops the flow of

  fluid through the bypass tube 194. The closure thus increases the damping forces in

  extension and to a lesser degree in compression.

  In Fig. 32, the embodiment of Fig. 23 is shown in the environment of a motor vehicle shock absorber. The piston is mounted inside a sealed intermediate cylinder 221, the upper piston rod 16 slidably penetrating into a seal 220 on the upper end of the cylinder 221. The upper end 244 of the piston rod 16 is threaded externally and a mounting hole adapter 245 is screwed on the top end 244 or attached

otherwise to this one.

  A circular cylindrical section 246 of the piston rod 16 extends immediately below the threaded end 244. The cylindrical portion 246 terminates in a shoulder 247 extending radially outwardly from the cylindrical portion 246. A dust tube cap 248 abuts the shoulder 247. A radially extending vertical slot 234 enters (i) the outer surface of the threaded upper end 244 and (ii) the cylindrical section 246 to communicate with the passage. wire 98 of the piston rod 16 and accept the inwardly extending shank 255 of the cap 240 as shown in FIG. 36. An inclined nose 249 of a wire stress release member 238 enters the vertical slot 234 so as to provide a protective passage for the wires 99 through a central wire passage 250 extending over the

  length of stress release element 238.

  Stress release member 238 is secured in position in vertical slot 234 by anchor cap 240. The bottom surface of the anchor cap abuts the top surface of dust cap 248 and the upper surface of the hood. anchor abuts against the bottom surface of the mounting hole adapter 245. As shown in FIGS. 34 and 35, the stress release element 238 has a section

  median 216 whose shape corresponds to the upper surface of the dust cap 248 and abuts

  block against the lower surface of the anchor 240.

  The stress release member 238 therefore can not rotate relative to the piston rod 216 or through

  compared to the mounting hole adapter 245.

  As shown in FIG. 32, the inner cylinder 254 has an upper cavity 252 and a lower cavity 253, the piston 22 separating the two cavities 252, 253. The oil from the lower cavity 253 must

  to flow into a reservoir cavity 261 through

  A base valve system 257 is provided to move the piston rod 12 downwardly by compression. Likewise, the oil must flow in the opposite direction to obtain the movement of the piston rod 12 upwards.

in extension.

  Flow of fluid through remotely controlled fluid passages has been described. As shown in FIG. 32, however, the fluid may also pass from one cavity to the other during compression by flowing between the inner surface and the inner cylinder wall 254 and the outer circumferential periphery of the piston 22. Spring loaded piston seal 25 limits the volume of the fluid flow in this manner. The piston branch joint assembly 256 has an inclined metal upper ring or support 258, a lower metal plane ring or protector 260, and a sealing ring 262 sandwiched between the support and protector rings 258, 260 in its entirety. extending radially outwardly therefrom. The sealing ring 262 thus tightly and slidably contacts the inner wall of the inner cylinder 254. The lower edge of the vertical wall portion of the carrier 258 is urged to contact the radially extending surface 264 of the piston.

  22 by a compression bypass spring 266.

  The upper end of the piston bypass spring 266 abuts against the radially extending lower surface of the piston stop 185, while the bottom 286 of the spring 266 bears against the upper surface of the carrier 258 to axially compress the seal 262. and urging the lower surface of the protector 260 to push against the radially extending surface 264

* piston 22.

  The piston seal 256 provides an additional mechanism for varying the resistance to movement of the piston 22 during a compression stroke. The fluid pressure against the lowest surface of the protector 260

  push the seal 262 against the horizonally extending surface

  of the support ring 258, which compresses the seal 262 and allows the protector 260 to move vertically and to discover the small slots 280 wedged in the lower edge of the vertical leg of the support 258. The slots 280 provide a communication of restricted fluid allowing the fluid to flow from

  the chamber 253 below the piston to the chamber 252

  top of the piston during the compression stroke of the shock absorber. At a predetermined speed of the piston, the fluid force overcomes the preliminary load of the spring 266, moving the protector 260, the seal 262 and the support ring 258 vertically away from the radially extending surface 264 and thus by allowing increased upward fluid flow between the vertical leg of the corner ring 258 and the upper surface

  290 of the piston 22 and then into the chamber 252.

  This allows a movement of the rod 16 in compression

  when the fluid moves not only through the

  intermediate of the adjustable valve as described above, but also beyond the outer periphery of the piston 22 adjacent the branch joint assembly of

piston 256.

  A two-way compression base valve assembly 257 is secured near the lower end of the inner cylinder 254. When the compressive forces are sufficiently high on the piston 22, the compression valve 259 opens against the force of pressure. solicitation

  going up the compression valve spring 274-

  to provide a flow of fluid from the lower chamber 253 into the base chamber 278 and the reservoir 261 between the outer surface of the inner cylinder 254 and the inner surface of the intermediate cylinder 221. This provides a flow of fluid into the base chamber 278 and out of it and also into and out of an oil reservoir chamber 261. The inner cylinder head 19 fixes the upper piston rod 16 with sliding in the intermediate cylinder 221. The piston seal 220 provides a dynamic seal with the piston rod 16 and a

  static seal with the intermediate cylinder head 251.

  In Figs. 46 and 47, the third alternate embodiment, generally designated by reference numeral 450, is the most preferred form according to the present invention. This embodiment 450 allows for greater disparity between the two damping levels, a soft level and a firm level when there are relatively weak influences of the

  on the shock absorber 450. With this form of

  450, the passenger of the vehicle may perceive a relatively large disparity between the two damping levels, soft and firm, even on a smooth road to

  cruising speeds in a classic automobile.

  In FIGS. 46 and 47, this variable damper 450 has upper fluid slits 452, 453, 454, 455 (454 and 455 are not shown in FIG. 46) in the cylinder cap 456 which seals the most 458 of the inner cylinder wall 458. As shown in FIG. 47, the four upper fluid slits 452-455 extend radially outwardly from the radial cap edge 460 to provide a flow path for damping the fluid, as shown in Fig. 46, between the inner chamber 462 within the inner cylinder wall 458 and the outer chamber 464 surrounding the inner cylinder wall 458. The third embodiment 450 also has a plurality of passages Piston fluid 466 and 468 extend radially outwardly from the wider lower passage 470 of the piston 472 toward the periphery of the piston between the piston seal 474 and the lower end of the piston. The fluid passages 466 and 468 provide an additional path for the flow of fluid between the wider underpass 470 in the piston 472 and the inner chamber 462 as the fluid pressure from the wider lower passage 470 the piston seal 474 during compression is sufficiently high to compress the seal spring 478 and push the seal 474 away from the seal surface

extending radially 480.

  The third embodiment 450 also has a compression head 476 attached to the lower end portion of the inner wall 457. The compression head 476 has a first valve 482 and a second valve 484. The first valve 482 allows the flow of the fluid from the lowest fluid cavity 486 in the shock absorber 450 to the chamber above the compression head 476 and below the piston 472 when the fluid pressure within the chamber 486 when expanding the shock absorber 450 is sufficient to lift the valve 482 by compressing the first valve spring 483. The second valve 484 allows fluid flow to the lowest fluid cavity 486 from the chamber above and in the vicinity of the compression head 476 when the fluid pressure above the compression head 476 is sufficient to

  compressing the second valve spring 485.

  This third embodiment 450 thus provides additional flow paths as the compressive and extending forces and the associated fluid pressures become large enough to compress the respective valves and associated springs. These additional flow paths provide a greater response of the shock absorber when the compression or extension forces are sufficiently large.

  At the same time, the variable mechanism of amor-

  Generally referred to as the control of the addition fluid valve control and the flow passages within the piston during expansion compression. In conjunction with the additional flow paths provided by the additional structure of this embodiment 450, the two damping levels provided by the mechanism 490 are much more different, in

  particularly at low speeds on the road and

  This greatly increases the usefulness of the 450 shock absorber for the user, by providing a distinct drive.

  firm or soft as desired, in a relative range

  wide range of road surfaces and vehicle speeds.

  In Figs. 37 and 38a, the motor 86 is a DC motor that rotates both in the forward direction and in the reverse direction to drive the metering pin 136, as shown in Fig. 1, in an axial direction. to seat or not inclined periphery 142 on an inclined stop collar. When the inclined periphery 142 rests against the inclined stop collar 52, the motor armature can no longer rotate. This causes an electrical transient 315 (FIG. 38a) which develops in the current supplying the motor. A transient current 315 is also produced when the slider 126 is pulled upwards along its entire length and the cylindrical flange portion 127 (FIG. 4) rests against the annular bottom surface 105 (FIG.

motor 84.

  As shown in Fig. 37, a current detector 317 detects the current transient 315 and produces a signal to a switching logic 319. In response, the switching logic 319 interrupts the electric power supplied to the motor. The current is supplied to the motor 86 by two conductors 96a, 96b. When the conductor 96a is positive with respect to the conductor 96b, the motor 86 is driven in the direction of clockwise. When the conductor 96b is positive with respect to the conductor 96a, the motor 86 is driven in the direction

  opposite of that of the hands of a watch.

  A motor control logic 321 provides control voltages to the switching logic 319 on two leads 323, 325. The logic 319 responds to the control signal on the conductor 323 so as to determine the direction of rotation of the motor. The logic 319 responds to the command signal on the driver 325 to start the start and stop conditions of the engine. The switching logic 319 switches the actual connection of the leads 96a or 96b with a

  input voltage VB and with a connection to ground.

  A manual switch 327 is actuated by the driver of the vehicle so as to switch the direction of rotation of the motor and to drive the metering pin 136 to its opposite seated position, in which the motor stops. By operating the switch 327, the motor control logic 321 places a voltage on the leads 323, 325. The drive motor current of the dosing pin can be manually switched by

  the driver of the vehicle or can be automatically checked

  signals produced by remote sensors, for example, speed, load, acceleration of the vehicle or a combination thereof.

  parameters as represented by the detector 329.

  As can be readily understood, the motor 86 may be replaced by a stepper motor or by a counter and a rotation controller to provide a plurality of valve positions of the position

  fully open to the fully closed position.

  In FIG. 39, a first embodiment of the control circuit is shown. A conventional IC chip 401 (manufactured for example by Sprague Electrical Company as UDN chip 2953B) controls the direction of flow of current to motor 86. Chip 401 is a conventional current / voltage control chip 401 having current / voltage input pins P9, P16, current / voltage output pins PlIO, P15, a direction control pin P7, a gate pin P8, and

  stop and control pins P2, P3, P11.

  The chip 401 receives a logic voltage and is grounded in the usual manner. Pin P6 of chip 401 receives a logic voltage supply

264396Â

  5 volts to control the logic gates inside the chip; and the pins P4, P5, P12, P13,

P14 are related to the mass.

  The pins P9, P16 of the chip 401 receive the supply voltage of the motor VB which is connected by internal power transistors either to the output A (pin P10), or to the output B (pin B15) in order to be able to control the motor 86. The phase line pin or PH P7 determines whether the motor supply voltage arrives from the output A to the output B or from the output B to the output A. For example, if the line PH is set on HIGH, the motor 86 is rotated in one direction and if the line PH is set to BAS, the motor 86 is rotated.

in the opposite direction.

  A register R1 is connected across the terminals of the pin Pl1 and the ground to determine the limit

  special when the current passes through the motor 86.

  As shown in Fig. 40, the motor current passes through the resistor R1 to ground. The tension developed

  the terminals of resistance R1 is compared by an amplification

  comparator 406 (housed within the chip 401) to a reference voltage produced by the internal resistors 405, 406, 407. When the voltage across the resistor R1 reaches a predetermined value, the comparator 403 generates a signal output signal for triggering the flip-flop 409. The synchronization of the flip-flop 409 is established by a resistor 411 and a capacitor 413 connected in parallel across the terminals of the pin P3. The output of the flip-flop 409 is returned to the internal logic of the chip 401 to control the running and stopping of the motor by a

  cutting of the current, as is easily understood.

  This step and stopping of the motor 86 serve to limit the

current through the motor 86.

  The pin P3 of the chip 401 is intended to set the period intended for the flip-flop 409 by connecting

  an R-C circuit to the pin P3 as shown in Figure 40.

  However, the pin P3 is used differently in the circuit of Fig. 39 in which the pin P3 provides a signal from the chip 401 which indicates that the value of the current through the resistor R1 has reached a value of

  point o flip-flop 409 starts cutting the current.

  The value of the resistor R1 is set so that the operation of the comparator 403 (FIG. 40) does not start until the voltage transient 315 (FIG. 38c) takes place. When the motor 86 is driven as far as possible and the voltage transient 315 takes place, a signal is developed on the pin P3. This signal is used in the circuit of FIG.

stop the engine 86.

  Again in Fig. 39, an operational amplifier 415 is connected as illustrated to exert a conventional rocker action to produce an output

  HIGH or LOW to trigger the P8 pin of the 401 chip.

  When the operator actuates a manual switch 417, a

  transition coupled into alternating current switches the amplifier

  operational indicator 415 by driving the line of

  to LOW value. When the trigger line

  is LOW, the engine 86 is started and trained in accordance with the direction indicated on the line

PH.

  The operational amplifier 415 is reset to its first condition (HIGH output) by the signal on the pin P3 of the chip 401. The signal on the pin P3, indicating that the voltage transient 315 has occurred, readjusts the operational amplifier 415 by driving the trigger line (pin P8) to the

  HIGH value. This stops the motor 86.

  The transition of the trigger line (PS) from HIGH to LOW, to trigger the motor 86, also drives a transistor 419 so that the pin P2 of the chip is momentarily set to the HIGH value. This prevents (i) that the incident current transient of the motor 314 (FIG. 38a) triggers the operational amplifier 403 (FIG. 40), and (ii) the generation of a signal on the pin P3 which would switch the operational amplifier 415. Thus, the motor 86 is prevented from

  to stop because of the current incident transient 314.

  As is readily understood, the voltage level on the pin P2 is defined in the specifications of the chip 401 and determines the level at which the motor current is cut. In particular, 2.5 volts are on the pin P2 in the circuit of FIG. 39. When the trigger line goes from a voltage level HIGH to a voltage level BAS, the signal developed on the pin P2 increases momentarily. above the level of 2.5 volts. Likewise, when the trigger line changes from LOW to HIGH, the voltage on pin P2 drops momentarily below the voltage level of 2.5. This momentary fall dynamically brakes the motor

86.

  When the switch 417 is moved to the point A, a voltage appears at the node of the circuit 421 and causes the pin PH P7 to the value HIGH. When the switch 417 is moved to the point B, the voltage on the node 421 is grounded, which causes the pin PH P7 to the value LOW. In both cases, however, the operational amplifier 415 is switched to drive the trigger pin P8 to the LOW value for

trigger the engine 86.

  The node 421 is connected by the conductor 431 to three additional circuits which are the same as the circuit of the dotted block 433. Each of these circuits

  additional is connected to a separate shock absorber.

  Four shock absorbers of this type are provided so

usual in the system.

  The current through the motor can be controlled using the chip in two ways. One way sets the value of the resistance on the pin Pll and the other method sets the voltage level on the pin

P2 VREF / BRK.

  A second embodiment of the control circuit is shown in FIGS. 41, 42 and 44. In FIG. 41, the motor 86 is connected to the chip 401 in a manner

  similar to that described with respect to Figure 39.

  In the embodiment of the circuit of FIG. 39, the value of the resistor Ri establishes the threshold level of the motor current at which the motor 86 stops. The chip 401 also makes it possible to establish a threshold level of motor current by the voltage level on the pin P2, the pin

VREF.

  In Fig. 42, an external sense circuit monitors the cross voltage of Ri that develops on pin P1l of the chip. An operational amplifier 501 has a non-inverting input connected to the pin P11 to receive the voltage across the resistor R1. The operational amplifier 501 detects the incident current transient 314 (Fig. 38a) and charges a capacitor 503 at the incident transient. The level of this transient, which is directly related to the temperature of the environment outside the damping system, determines the amplitude of the deposited charge

on the capacitor 503.

  In Fig. 38b, a graph compares the motor current waveforms 316 and 318 which are temperature dependent representations of the waveform 312 (Fig. 38a). As the external temperature increases, the electrical resistance of the armature windings of the motor's copper motor 86 increases and the viscosity of the damping fluid decreases, thereby decreasing the mechanical load on the motor 86. The combination increased electrical resistance and decreased load at high temperatures reduces the control current of the motor 86. Therefore, the incident current transient 322 of the waveform 318 which occurs at high temperatures has an absolute magnitude lower than the incident current transient 320 of the waveform 316 which occurs at low temperatures. By

  Therefore, the voltage initially set on the capacitor

  503 (Figure 42) by the current transient

  incident varies according to the temperature.

  The voltage on the capacitor 503 is discharged through a resistor 505. On the basis of the amount of time that the motor 86 turns before stopping, the voltage across the capacitor 503 discharges to about 75% of the capacitor. its original value stored at

moment of the stop.

  An amplifier 507 amplifies the voltage developed on the capacitor 503 and produces this amplified voltage on the P2 VREF pin. The voltage on the VREF pin P2 varies as the temperature fluctuates, varying the level at which the flip-flop 409 (FIG. 40) expands the signal on the pin P3 to signify that the current threshold of the motor is reached. When this signal appears on the pin P3, the trigger signal on the pin P8 is readjusted, which causes the stop of the

motor 86.

  Again in FIG. 42, a voltage divider 509 formed of two resistors connected in series

  set a fault value of 2.5 volts on pin P2.

  The operational amplifier 507 amplifies the voltage across the divider 509 to develop the 2.5 volts. In addition, a transition of the trigger voltage on pin P8 from LOW to HIGH momentarily acts on the voltage VREF of pin P2 to make it LOW, which causes the dynamic braking function. Likewise, a transition

  on pin P8, values HIGH to LOW bring momentary

  the voltage VREF of the pin P2 to a HIGH value, this

  which ignores the incident current.

  As is easily understood, three additional similar circuits are connected to the conductor 511 to produce the VREF voltage of the other three circuits

shock absorber.

  In FIG. 44, a switch 513 for the conductor can be manually operated in one of two positions so as to develop a control voltage on the pin P7 PH. In addition, a voltage is supplied to the LED elements 515, 517 to indicate which position occupies the driver's switch. A phototransistor 519 reacts at the light level surrounding the LED elements 515 and

  517 so as to place them in a dark environment.

  The movement of the switch 513 to either position produces an impulse output of

  voltage from the operational amplifier 521.

  A set of four 523 flip-flops is connected to the amplifier.

  Operator 521 to develop an output on the trigger pin P8 of each of the four shock absorbers. The flip-flops 523 are reset according to the signal developed on the pin P3 of each of the four shock absorbers. The voltage level DV1 is developed by a voltage divider 525 formed of two resistors connected in series. The voltage DV1 serves to set a comparator level on each of four comparators 527, 529, 531, 533 to establish a comparison with the signal developed on the pins P3. When the voltage level developed on the pins P3 reaches the threshold voltage DV1, the respective operational amplifier develops an output signal resetting its respective flip-flop 523. This changes the control voltage EN on the pin P8

  in order to stop the motor 86.

  A third embodiment of the control circuit is illustrated in FIGS. 43 and 45. The chip 401 is illustrated in FIG. 43 and is connected to

  entries similar to the one discussed above.

  above. The resistor R1 is connected between the pin P11 and the ground and a voltage signal resembling that shown in Fig. 38a develops across the resistor R1. A sampling / filtering and amplifying stage 535 of FIG. 43 includes a filter capacitor 537 which averages the incident peak in a manner similar to that shown at 539. The amplification state 535 storage capacitor 539 with the average voltage developed by the capacitor 537. The average voltage stored on the capacitor 539 passes through a buffer stage 541 and then reaches the VREF pin P2. As can be seen, the voltage on the VREF pin P2 sets a threshold level to keep the motor current at a certain value. When the motor current reaches a certain value as defined by the threshold signal on the pin P2, the chip 401 cuts the motor current to maintain the latter at this level. In fact, the voltage on pin P2 is developed in accordance with the amount of current used by the motor in the primary part of the gait cycle. The

  motor 86 then continues to walk to that level par-

  ticular. The average motor current will vary in accordance with the temperature and viscosity of the oil as previously described. The stopping of the motor 86 is performed by an independent synchronizer rather than by the motor current. In FIG. 45, a manual switch 543 develops a voltage on pin PH P7. In addition, the signal from the switch 543 controls the LEDs 545 and 547 according to a method similar to that described with respect to the circuit of FIG. 44. The movement of the switch 543 switches the operational amplifier 549 so as to

  produce a voltage pulse output.

  The voltage pulse developed by the amplifier

  Operator 549 triggers a synchronizing circuit

  551 which develops an output along the conductor 553 which, in turn, is amplified by an amplifier 555 to produce a trigger signal on the pin 8. After 930 milliseconds, the timer circuit 551 removes its output signal from the driver 553. to distinguish the control signal on pin P8. This stops the motor 86. Thus, the timer 551 triggers the command of the motor 86 for a period of 930 milliseconds each

  once the switch 543 is actuated.

  The 930 millisecond period acts as a safety feature to prevent the engine from burning due to prolonged use. Engine 86 as designed will be tripped for the duration of the 930 millisecond period or gait cycle; however, the running time of the motor 86 operating in the primary part of its operating cycle varies depending on the temperature of the environment. The primary part of the gait cycle is the time elapsing between the arrival of transients 314 and 315 (Figure 38a). For the shock absorber shown in FIG. 2, for example, at the point where the motor 86 drives the metering pin 136 to rest against the inclined periphery 142, a current transient 315 takes place, which starts the cutting current that keeps the motor current at the threshold level. The current cut will persist until the end of the 930 millisecond period and at this time the motor 86 will stop and the cycle will end. The 930 millisecond run cycle is slightly longer than the worst case caused by the environmental temperature. On the other hand, in the embodiment of FIG. 17, the current transient 315 occurs when the arms 203 of the rotary limit arm 228 contact one or the other of the stop faces 209 of the element. 212. As with the embodiment of Figure 1, this current transient 315 causes the same type of current cutting, motor shutdown and termination of the run cycle. In addition to the operational amplifier 555 which has already been discussed, three other operational amplifiers 557, 559, 561 produce respective voltages VREF1, VN, SV1. These voltages are used in the circuit of FIG. 43 where indicated. As can be understood, another similar circuit is used to provide control of all four

shock absorbers.

  While the description above provides some

  details of the preferred embodiments, it is not

  that is illustrative and does not have any limiting values in itself.

  The scope of the present invention is thus determined by

  the contents of the following claims.

Claims (12)

  A shock absorber piston with variable damping and controlled remotely, characterized in that it comprises in combination: a piston head (10) connected to a piston rod (14, 18), an internal cavity (64). ) extending axially within. this piston rod, a motor (86) disposed in the internal cavity and having a control (94) as well as means for alternately rotating the control in one or the other   two directions, a passage (98) for wires extends   of the cavity. internal to a point outside the piston rod, two wires (96) arranged inside the passage (98) and connected to the motor, at least one fluid passage (24, 26, 28, 30, 32) to allow a flow of fluid during the movement of the piston head, a valve (34) connected to the control and moving in accordance with the rotation of this control so as to cooperate with the fluid passage to achieve fluid flow, switching means (327) operable manually to start the rotation of the motor, and an electrical circuit responding to the actuation of the switching means so as to provide a voltage across the two wires (96a, 96b) for driving the motor (86), the electric circuit comprising means for developing a motor voltage and a ground connection, switching logic (319) for switching the motor voltage and the ground connection between the two wires in response to the 'action of switching means, the   switching logic comprising means for switching   to allow application of the motor voltage to one of the two wires in response to actuation of the   switching means, and stop means for inter-   to break the application of the motor voltage to the two wires, these means comprising decision means for stopping   the engine when the valve is in a predetermined position   mined with respect to the fluid passage.   Shock absorber piston according to Claim 1, characterized in that the decision means comprise current detection means (317) for monitoring the current through the motor through report has a threshold level.   3. Impact absorber piston according to claim 1, characterized in that the decision means comprise synchronization means for interrupting the application of the motor voltage after a predetermined fixed period, and means for cutting the current for cut the current to the motor when that current reaches a threshold level.   Shock absorbing piston according to Claim 2 or Claim 3, characterized in that the threshold is set after each actuation of   switch according to the current to the motor.   5. Shock absorber piston according to one   any of the preceding claims, characterized in that   what the wires (96) are two in number and penetrate in the passage (98) for wires.   6. Shock absorber with variable damping   perfected, characterized in that it comprises   a first cylinder having a penetrating piston passage at one end of the cylinder, a piston (21) having a piston head at one end, slidably disposed within the first cylinder, a piston rod (14), , 18) having an intermediate section extending from the piston head through the piston passage in the first cylinder and terminating in an outer end, external to the first cylinder, an inner cavity (64) extending axially to the first cylinder, piston rod (14, 18), a passage (98) for two wires from the inner cavity to the outer end of the piston, and a first piston fluid passage (24, 26, 28, 30). , 32) providing means for establishing fluid communication between the inner cavity (64) and the outer periphery of the piston with provision within the first cylinder, a two-wire conductor (96) extending into the passage ( 98) to the int cavity piston, a motor (86) disposed in the inner cavity of the piston rod (14, 18) and attached to the two-wire conductor (96), the motor having a control means, and the motor and the driving conductor in cooperation means for rotating alternately the control means in one direction and then in the other   direction, a valve (34) arranged axially inside the   of the cavity and fluid passage on the opposite motor side to the two-wire conductor, and valve means for converting the rotation of the control means into a movement of a valve pin (156) therein of the cavity, so that the rotation of the valve spindle drive in one direction places the valve (34) in one direction to open the fluid passage and that the alternating rotation of the control means in the opposite direction moves the spindle valve in the opposite direction so as to close the fluid passage. Shock absorber according to Claim 6, characterized in that the valve (34) is a slide valve and that the valve means comprise a valve stem threaded between the control means and the valve (34). converting the rotary movement of the control means into a movement of   sliding of the slide valve.   Shock absorber according to claim 6, characterized in that the valve (34) is a rotary valve (172), the control means (239) rotating the rotary valve between an open position and closed in the fluid passage.   9. Shock absorber according to any one of   claims 6, 7 and 8, characterized in that the   first cylinder is disposed within the second cylinder and in that the first cylinder has at least a first cylinder fluid passage and a second cylinder fluid passage, each passage providing means for fluid flow from the first cylinder; interior of the first cylinder through the first cylinder towards a fluid zone between the first and second cylinders, the first cylinder fluid passage being adjacent to an end of the first cylinder and the second cylinder fluid passage being close to   the opposite end of the first cylinder.   Shock absorber according to Claim 9, characterized in that the piston also comprises at least a second and a third fluid passage (24, 26, 28, 30, 32) for establishing fluid communication between the internal cavity ( 64) on the side of the valve opposite the control means and the outer periphery of the piston, with   arrangement inside the first cylinder.   11. A shock absorber according to claim 1, characterized in that it comprises at least a first compression valve (257) to terminate in a controlled manner the flow of fluid between the internal cavity and   the fluid zone between the first and the second cylinder.   A shock absorber according to claim 11, characterized in that it comprises at least a second compression valve (259) for controlled termination of fluid flow in the third passage of the piston fluid.