Adjustable double-acting damper

A damper for acting between two relatively movable objects comprising:

• a) housing means adapted to be operatively connected to one of said objects;
• b) piston means comprising a head within said housing means and a rod extending from said housing means and adapted to be operatively connected to the other of said objects;
• c) said housing means including means defining an elongated cavity for containing hydraulic fluid, said piston head being received by said cavity so as to separate said cavity into a first variable-volume chamber and a second variable-volume chamber and adapted to slidably move relative to and along the length of said elongated cavity and thereby vary the volumes of said first and second chambers in response to relative movement between said two objects, said housing means further including means defining first and second access openings, a first passage, a second passage and a third passage, said first chamber communicating with said first access opening through said first passage, said second chamber communicating with said second access opening through said second passage, and said first and second access openings being in communication through said third passage;
• d) a first hydraulic fluid flow control means including a first body sealingly accepted by one of said first and second access openings and defining a passageway therethrough providing flow communication between the particular ones of said first, second and third passages in communication with one of said access opening and thereby providing a flowpath for hydraulic fluid forced to flow therebetween, said first flow control means further including means associated with said first body passageway for adjustably metering the flow of hydraulic fluid in one direction through said first body passageway so that as hydraulic fluid is forced to flow through said first body passageway in said one direction, the damping effect of said damper is controlled and for allowing substantially unrestricted flow of hydraulic fluid in the other direction;
• e) a second hydraulic fluid flow control means including a second body sealingly accepted by the other of said first and second access openings and defining a passageway therethrough providing flow communication between the particular ones of said first, second and third passages in communication with said other access opening and thereby providing a flowpath for hydraulic fluid forced to flow therebetween, said second flow control means further including means associated with said second body passageway for fixedly metering the flow of hydraulic fluid through said second body passageway in said other direction through said second body passageway so that as hydraulic fluid is forced to go through said second body passageway in said other direction, the damping effect of said damper is controlled and for allowing substantially unrestricted flow of hydraulic fluid in said one direction so that said first and second flow control means provide a flow path for hydraulic fluid forced to flow between said first and second chambers as the volumes of said chambers are varied by the relative movement of said two objects whereby said first flow control means provides adjustable tension damping or compression damping depending upon which each access opening it is in and said second flow control means provides fixed compression damping or tension damping depending upon which access opening it is in;
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• f) said body of each of said first and second flow control means being independently releasably accepted by a corresponding one of said access openings so as to permit either of said flow control means to be easily and independently separated from the remainder of said damper.

A damper for acting between two relatively movable objects comprising:

• housing means adapted to be operatively connected to one of said objects;
• piston means comprising a head within said housing means and a rod extending from said housing means adapted to be operatively connected to the other of said objects, said housing means including means defining an elongated cavity for containing hydraulic fluid, said piston head being received by said cavity so as to separate said cavity into a first variable-volume chamber and a second variable-volume chamber and adapted to slidably move relative to and along the length of said elongated cavity and thereby vary the volumes of said first and second chambers in response to relative movement between said two objects toward and away from one another, said housing means further including means defining a first access opening, a first passage and a second passage, said first chamber communicating with said access opening through said first passage and said second chamber communicating with said access opening through said second passage;
• first hydraulic fluid flow control means including a body sealingly accepted by said access opening and defining a passageway therethrough providing flow communication between said first and second passages and thereby providing a flow path for hydraulic fluid forced to flow between said first and second chambers as the volumes of said chambers are varied by said relative movement of said two objects toward and away from one another, said flow control means further including means in said body and associated with said body passageway for controlling the flow of hydraulic fluid in one direction through said passageway so that as hydraulic fluid is forced to flow through said passageway in said one direction, the damping effect of said damper is controlled, said passageway including a chamber having a flow inlet end and flow outlet end and said means associated with said passageway including a flow control element in said body and received by said chamber, said flow control element adapted to be biased toward the chamber inlet or outlet end having the lower fluid pressure, one of said inlet and said outlet ends being of such a conformation that when hydraulic fluid pressure is lower at said one end than the fluid pressure at the other end, said flow control element and said one end cooperate to controllably restrict the flow of hydraulic fluid through said passageway and the other of said inlet and said outlet ends being of such a conformation that when hydraulic fluid pressure is lower at said other end than the fluid pressure is lower at said other end than the fluid pressure at said one end, said flow control element and said other end cooperate to permit substantially unrestricted flow of hydraulic fluid through said passageway, said one end of said chamber defining a contoured surface of such configuration that flow of hydraulic fluid through said one end is controlled by controlling the positional relationship of said flow control element to said contoured surface and said flow control means including adjustment means in said body for adjusting the positional relationship of said flow control element to said contoured surface of said one end, said adjustment means including flow control element contacting means mounted for movement relative to and within said body passageway for moving said flow control element relative to said contoured surface between one positional relationship with and within said chamber and another such positional relationship, said body of said control means defining an elongated opening extending therethrough, said elongated opening having one portion defining at least a portion of said passageway and having another portion, said adjustment means including an adjustment portion and a stem portion extending from said adjustment portion, said adjustment portion being movably and adjustably mounted in said another portion of said elongated opening for adjustable movement of said adjustment means relative to and along the length of said elongated opening as said adjustment portion is moved relative to said body of said control means, and said stem portion extending from said adjustment portion and into said chamber for contacting said flow control element for moving said flow control element between said one positional relationship with said contoured surface and another as said adjustment portion is moved relative to said body;
• said first control means controlling hydraulic fluid flow in one direction between said first and second chambers, said housing means including means defining a second access opening arranged in fluid communication with said passageway of said first control means, with said first passage and with said second passage, and said damper further comprising a second hydraulic fluid flow control means including a body sealingly accepted by said second access opening and defining a passageway through said body of said second flow control means providing flow communication between said first and second passages and thereby providing a flow path for hydraulic fluid forced to flow between said first and second chambers, said second flow control means further including means in said body of said second flow control means and associated with passageways for controlling the flow of hydraulic fluid therethrough in the direction opposite said one direction so that as hydraulic fluid is forced to flow through said passageway of said second flow control means, in said opposite direction, the damping effect of said damper is controlled;
• said means associated with said body passageway of said second flow control means comprising a flow control element in said body of said second flow control means and freely movable in said passages of said second flow control means between a first position blocking fluid flow in said one direction and a second position allowing free flow in the opposite direction, adjustment means in said body of said second flow control means operatively contacting said flow control element in said body of said second flow control means relative to said first position thereby metering the fluid flow in said one direction, and stop means in said body of said second flow control means for engaging said flow control element in said body of said second flow control means at said second position during free flow in the opposite direction;
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• said body of each of said flow control means including said passageway, said flow control element, said adjustment means and said stop means being independently releasably accepted by a corresponding one of said access openings so as to permit said first and second flow control means to be easily and independently separated from the remainder of said damper so that each flow control means can be cleaned, repaired and modified without disassembly of the remainder of said damper.

In a damper for acting between two objects subject to relative movement including a housing assembly defining an elongated cavity for containing hydraulic fluid, a piston assembly including a head slidably received by said cavity and separating said cavity into a first chamber and a second chamber and means supported by said housing defining a flow passage communicating between said first chamber and said second chamber, said housing and said piston assembly adapted to be operatively connected to a corresponding one of said two objects so that as said two objects move relative to each other, said piston head reciprocates in said cavity and forces hydraulic fluid to flow through said flow passage between said first and second chambers, an improved flow control means operatively associated with said flow passage defining means and including:

• a) a body defining a passageway portion of said flow passage and means associated with said passageway portion for metering the flow of hydraulic fluid in one direction through said passageway portion so that as hydraulic fluid is forced to flow through said passageway portion in said one direction, the damping effect of said damper is controlled, and for allowing substantially unrestricted flow of hydraulic fluid in the other direction through said passageway portion;
• b) said housing including means defining an access opening;
• c) said body of flow control means being releasably accepted by said access opening so as to permit said flow control means to be easily separated from the remainder of the damper;
• d) said passageway portion including a ball chamber having a flow inlet end and a flow outlet end and said means associated with said passageway portion including a spherical ball received by said ball chamber, said ball adapted to be biased by the flow of hydraulic fluid toward the ball chamber inlet or outlet end having the lower fluid pressure, one of said inlet and said outlet ends being of such a conformation that when hydraulic fluid pressure is lower at said one end than the fluid pressure at the other end, said ball and said one end cooperate to controllably restrict the flow of hydraulic fluid through said passageway portion, and the other end of said inlet and outlet ends being of such a conformation that when hydraulic fluid pressure is lower at said other end than the fluid pressure at said one end, said ball and said other end cooperate to permit substantially unrestricted flow of hydraulic fluid through said passageway;
• e) said ball chamber providing a first conduit portion of said passageway portion, said one end of said ball chamber being adapted to sealing accept said ball when the fluid pressure at said one end is lower than the fluid pressure at said other end, and said passageway portion includes a second conduit portion arranged in parallel flow relation with said first conduit portion so that when the fluid pressure at said one end is lower than the fluid pressure at said other end, said ball is sealingly accepted by said one end and the entire flow of hydraulic fluid in said one direction through said passageway is directed through said second conduit portion, said second conduit portion being provided by an aperture of predetermined shape and size for controllably restricting the flow of hydraulic fluid when said flow is entirely directed through said second conduit portion.