Patent US4588171A successfully refreshed from Google Patents.
← Back to Patent Explorer
US4588171A Expired / Lapsed US ⏱️ 0.0 years remaining

Shock absorber and air spring assembly

Assignee: Enerpac Tool Group Corp
•
Filing: 1981-12-18
•
Granted: 1986-05-13
•
Expires: 2001-12-18
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A shock absorber and air spring assembly particularly adapted for use in a tilt cab suspension system. It provides the capability of remotely adjusting the amount of damping on the down stroke of the damper piston.

Inventors

  • 👤 Robert K. Stephens

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-06 11:32
CPC Classifications
F; F16; F16F; F16F9/00; F16F9/32; F16F9/44; F16F9/46; B; B62; B62D; B62D33/00; B62D33/06; B62D33/063; B62D33/067; B62D33/07; B62D33/071; F16F9/02; F16F9/04; F16F9/05; B60; B60G; B60G2202/00; B60G2202/30; B60G2202/31; B60G2202/314; B60G2204/00; B60G2204/10; B60G2204/12; B60G2204/129; B60G2204/40; B60G2204/416

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 288 words
An integral shock absorber and spring assembly for remotely adjusting the amount of damping on a down stroke of the shock absorber comprising: (a) a first base; (b) a rod projecting from said first base; (c) a second base; (d) a cylinder projecting from said second base, said cylinder containing a first bore having a first end and a second end, the first end being closed by a cap through which said rod slidingly projects; (e) a piston carried by said rod within said first bore; (f) a reservoir for hydraulic fluid; (g) a first path of fluid communication from the first end of said first bore to said reservoir; (h) a second path of fluid communication from the second end of said first bore to the first end of said bore, said second path including, a first longitudinal bore in said second base in communication with said first bore, a radial bore in said second base in communication with said first longitudinal bore and said second base, a remotely adjustable flow control valve within said radial bore in said second base, a second longitudinal bore in said second base in communication with said radial bore, a one-way valve contained in said second longitudinal bore which permits fluid flow towards the first end of said first bore but prevents fluid flow in the opposite direction, and a conduit in said cylinder in fluid communication between said second longitudinal bore in said second base and said first bore on the first side of said piston; and (i) a spring surrounding said rod and said cylinder and being connected at one end to said first base and at the other end to one of said second base or said cylinder.
Claim 2
Dependent Claim 288 words
An integral shock absorber and spring assembly for remotely adjusting the amount of damping on a down stroke of the shock absorber comprising: (a) a first base; (b) a rod projecting from said first base; (c) a second base; (d) a cylinder projecting from said second base, said cylinder containing a first bore having a first end and a second end, the first end being closed by a cap through which said rod slidingly projects; (e) a piston carried by said rod within said first bore; (f) a reservoir for hydraulic fluid; (g) a first path of fluid communication from the first end of said first bore to said reservoir; (h) a second path of fluid communication from the second end of said first bore to the first end of said bore, said second path including, a first longitudinal bore in said second base in communication with said first bore, a radial bore in said second base in communication with said first longitudinal bore and said second base, a remotely adjustable flow control valve within said radial bore in said second base, a second longitudinal bore in said second base in communication with said radial bore, a one-way valve contained in said second longitudinal bore which permits fluid flow towards the first end of said first bore but prevents fluid flow in the opposite direction, and a conduit in said cylinder in fluid communication between said second longitudinal bore in said second base and said first bore on the first side of said piston; and (i) a spring surrounding said rod and said cylinder and being connected at one end to said first base and at the other end to one of said second base or said cylinder.
Claim 3
Dependent Claim 14 words
An assembly as recited in claim 1 wherein said spring is an air bag.
Claim 4
Dependent Claim 58 words
An assembly as recited in claims 1 wherein said first path of fluid communication comprises a plurality of axially spaced second radial conduits leading from the first end of said first bore to said reservoir, whereby the effective cross-sectional area of the sum of said second conduits is reduced as said piston nears one end of its stroke.
Claim 5
Dependent Claim 22 words
An assembly as recited in claim 1 wherein said rod is mounted on said first base by means of a universal joint.
Claim 6
Dependent Claim 47 words
An assembly as recited in claim 1 and further comprising: (a) a conduit through said piston; and (b) a one-way valve contained in said conduit through said piston which permits fluid flow towards the first end of said first bore but prevents it in the opposite direction.
Claim 7
Dependent Claim 25 words
An assembly as recited in claim 5 wherein said conduit through said pistons permits a slower flow rate than said first path of fluid communication.
Claim 8
Dependent Claim 45 words
An assembly as recited in claim 1 wherein: (a) said spring is an air bag; (b) said second base has an external neck adjacent to said air bag; and (c) said air bag is designed so that, when it expands, it expands into said neck.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1989-05-12 1989-11-11 1990-05-13 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1993-05-12 1993-11-11 1994-05-13 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1997-05-12 1997-11-11 1998-05-13 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag