Brakes – Internal-resistance motion retarder – Position of thrust member relative to chamber
Patent
1982-09-20
1989-06-13
Reger, Duane A.
Brakes
Internal-resistance motion retarder
Position of thrust member relative to chamber
18832217, F16F 949
Patent
active
048383937
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
This invention relates to a stop for a shock absorber and, more particularly, to a hydraulic assisted rebound stop.
BACKGROUND DISCLOSURE INFORMATION
Often shock absorbers are designed such that the damping rate of the shock absorber becomes higher at the extreme ends of the rebound and compression strokes. The additional damping is desired to prevent an abrupt halt to the piston stroke and to prevent jarring metal-to-metal contact between the various parts in the shock absorber. A variety of mechanisms have been devised to render a higher damping rate at the two extremes. Springs and elastomeric jounce bumpers have been incorporated internally as well as externally of the working cylinder. In addition, secondary pistons have been used which become operative only at the extreme ends of the piston stroke. All previous mechanisms added to the cost of the shock absorber.
It is desired to have a hydro-mechanical stop which effectively dampens the end of a piston stroke while being economical to manufacture and assemble.
One hydro-mechanical stop has been disclosed and claimed in a co-pending patent application filed on the same day as the present application by one of the present joint inventors, Mr. Jack Wayne Mourray, and entitled SHOCK ABSORBER WITH A HYDRO-MECHANICAL STOP now U.S. Pat. No. 4,527,674. The present invention is an improvement over the invention claimed in the mentioned co-pending application.
SUMMARY OF THE INVENTION
In accordance with the invention, a shock absorber has a working cylinder with a piston slideably received therein attached to a piston rod which extends through a rod guide at one end of the cylinder. A hydro-mechanical. stop is coaxially mounted about the piston rod between the piston and the rod guide. The hydro-mechanical stop includes a tubular resiliently flexible ring mounted about the piston rod. The flexible ring has an outer annular wall having a diameter smaller than the diameter of the inner wall of the working cylinder. The ring rests on a shoulder fixed to the piston rod. The ring is sized relative to the diameter of said piston rod to form an annular chamber therebetween. At the end of a rebound stroke of the piston rod, the ring is axially compressed between the shoulder and the rod guide. Hydraulic fluid is forced from the annular chamber through a restrictive passage section. The ring is sufficiently flexible such that upon axial compression of a predetermined amount, the outer annular wall enlarges until it abuts the inner wall of the working cylinder to form with said cylinder and said rod guide a substantially closed hydraulic chamber. Upon further compression of the flexible ring, hydraulic fluid is forced from the annular chamber and the hydraulic chamber through a restrictive passage section to provide additional damping.
Preferably, collars are mounted at opposite axial ends of the flexible ring. It is desirable that each collar has an axial extending cylinder section with a central aperture therethrough large enough to receive the piston rod and to provide an annular space therebetween. The cylindrical section has an outer wall with a diameter sized such that the cylindrical section is pressed fit within an axial end of the flexible ring. In addition, each collar has a radially extending flange. Each flange has an axially inner facing surface which abuts an axial end of the flexible ring. The outer surface of one of the radially extending flanges has a plurality of circumferentially spaced protrusions which are abuttable with the rod guide. The outer surface of the other radially. extending flange has a plurality of protrusions which abut the shoulder fixed to the piston rod. Sections of the restrictive passage are formed by spaces between the protrusions and the annular space about the piston rod. One end of the passage communicates with the hydraulic chamber. The other end communicates with the lower portion of the rebound chamber in the working cylinder. The annular chamber is interposed between the two ends of the passage.
BR
REFERENCES:
patent: 2642845 (1953-06-01), Stephens
patent: 2673625 (1954-03-01), Crabtree
patent: 2981534 (1961-04-01), Peras
patent: 3109520 (1963-11-01), Vossieck
patent: 3412990 (1968-11-01), Gladstone
patent: 3605553 (1971-09-01), Panigati
patent: 3625320 (1971-12-01), Doetsch et al.
patent: 3920253 (1975-11-01), Bauer
patent: 4004662 (1977-01-01), Sorgartz et al.
patent: 4139182 (1979-02-01), Nagase et al.
patent: 4166612 (1979-09-01), Freitag et al.
patent: 4230309 (1980-10-01), Schnitzius
patent: 4240619 (1980-12-01), Wirges et al.
patent: 4286802 (1981-09-01), Roche
patent: 4397452 (1983-08-01), Fouts
The American Heritage Dictionary, Second College Edition (Boston: Houghton Mifflin Company, 1982), pp. 1063-1064.
Mourray Jack W.
Nagy James P.
Drouillard Jerome R.
Ford Motor Company
May Roger L.
Reger Duane A.
LandOfFree
Hydro-mechanical stop having a restrictive passage does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Hydro-mechanical stop having a restrictive passage, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Hydro-mechanical stop having a restrictive passage will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1270117