Restriction disc for shock absorber with optimized bleed range and tuneability

A shock absorber for a vehicle comprising:

• a pressure tube defining a fluid chamber;
• a piston body disposed within the fluid chamber, the piston body dividing the fluid chamber into an upper working chamber and a lower working chamber, wherein the piston body defines a first bleed passage and a first blowoff passage that each extend through the piston body between the upper working chamber and the lower working chamber;
• and
• a valve assembly comprising:
• a restriction disc including:
• a ring having a center hole;
• a first finger extending radially outward from the ring, the first finger configured to cover the first bleed passage, the first finger having a first bleed orifice, wherein the first bleed orifice remains open regardless of position of the restriction disc;
• and
• a second finger extending radially outward from the ring, the second finger configured to at least partially cover the first blowoff passage, wherein the valve assembly further comprises an orifice disc, wherein the restriction disc is positioned between the piston body and the orifice disc, the orifice disc including:
• a ring having a center hole;
• and
• a first finger extending radially outward from the ring, having a first bleed orifice, wherein the first bleed orifice remains open regardless of position of the orifice disc, wherein the first finger of the orifice disc overlaps the first finger of the restriction disc, and wherein the first bleed orifice of the orifice disc is aligned with the first bleed orifice of the restriction disc.

A shock absorber for a vehicle comprising:

• a pressure tube defining a fluid chamber;
• a piston body disposed within the fluid chamber, the piston body dividing the fluid chamber into an upper working chamber and a lower working chamber, wherein the piston body defines a first bleed passage and a first blowoff passage that each extend through the piston body between the upper working chamber and the lower working chamber, the piston body further defining a second blowoff passage and a third blowoff passage;
• and
• a valve assembly comprising:
• a restriction disc including:
• a ring having a center hole;
• a first finger extending radially outward from the ring, the first finger configured to cover the first bleed passage, the first finger having a first bleed orifice, wherein the first bleed orifice remains open regardless of position of the restriction disc;
• a second finger extending radially outward from the ring, the second finger configured to at least partially cover the first blowoff passage;
• a third finger extending radially outward from the ring, the third finger configured to at least partially cover the second blowoff passage;
• and
• a fourth finger extending radially outward from the ring, the fourth finger configured to at least partially cover the third blowoff passage.

A method for controlling the flow of hydraulic between an upper working chamber and a lower working chamber of a pressure tube through a piston disposed within the pressure tube, the piston having a pair of bleed passages and a blowoff passage, the method comprising:

• selecting one of a first restriction disc and a second restriction disc to define a desired damping response, wherein:
• the first restriction disc comprises:
• a first ring having a center hole;
• a first pair of fingers extending radially outward from the first ring, the first pair of fingers configured to cover the pair of bleed passages, each finger of the first pair of fingers having a first bleed orifice, wherein the first bleed orifice remains open regardless of position of the first restriction disc;
• and
• a first restriction finger extending radially outward from the first ring, the first restriction finger configured to cover a first percentage of the blowoff passage;
• and
• the second restriction disc comprises:
• a second ring having a center hole;
• a second pair of fingers extending radially outward from the second ring, the second pair of fingers configured to cover the pair of bleed passages, each finger of the second pair of fingers having a second bleed orifice, wherein the second bleed orifice remains open regardless of position of the second restriction disc;
• and
• a second restriction finger extending radially outward from the second ring, the second restriction finger configured to cover a second percentage of the blowoff passage, wherein the second percentage is different from the first percentage.