Head end closure for the cylinder of a piston and cylinder assembly

• US 4,079,925 A
• Filed: 08/02/1976
• Issued: 03/21/1978
• Est. Priority Date: 08/02/1976
• Status: Expired due to Term

• Current Assignee: Atwood Industries, Inc. (Stanley Black & Decker, Inc.)
• Original Assignee: Atwood Vacuum Machine Company
• Inventors: Salin, Gustav G.
• Primary Examiner(s): Marbert, James B.
• Application Number:
  US05/710,898
• Time in Patent Office: 596 Days
• Field of Search: 267/65 R, 267/65 A, 267/64 R, 267/64 A, 267/126, 267/129, 188/321, 188/322, 220/307, 220/67, 29/DIG. 35
• US Class Current: 267/129
• CPC Class Codes: F16F 9/0218 Mono-tubular units F16F9/0227, F16F9/0236, F16F9/0245 take precedence
• CPC Class Codes: F16F 9/3242 of cylinder ends, e.g. caps
• CPC Class Codes: F16F 9/36 Special sealings, including sealings or guides for piston-rods F16F9/325, F16F9/3485 take precedence; arrangements for filling via piston rod sealing or guiding means F16F9/432 ; sealing of moving parts in general F16J15/16 - F16J15/56
• CPC Class Codes: F16F 9/362 Combination of sealing and guide arrangements for piston rods F16F9/361, F16F9/365 take precedence
• CPC Class Codes: F16F 9/516 resulting in the damping effects during contraction being different from the damping effects during extension , i.e. responsive to the direction of movement F16F9/504 takes precedence

Abstract

A gas spring for movable members such as vehicle deck lids in which a piston assembly carried on the end of a rod slides back and forth in a cylinder to expand and contract the spring. The cylinder is sealed at the head end and also around the rod and is filled with a combination of oil and gas under pressure. The piston assembly is such that the passage of oil and gas from one side to the other is restricted as the spring is expanded by extending the rod and this produces a dampening action but the restriction is eliminated when the spring is contracted so that there is virtually no dampening effect. The head end of the cylinder is closed by a plug which includes an inner portion carrying an O-ring to form a seal between the plug and the cylinder and an outer portion with peripheral teeth which bite into the cylinder wall and hold the plug in place.

Claims

1. In a piston and cylinder assembly having an elongated cylinder with a head end and a rod end, a piston slidable in said cylinder and a rod connected to said piston and projecting out of said cylinder through said rod end, said cylinder being formed by a wall of preselected thickness and having predetermined internal and external diameters, a closure for said head end, said closure comprising a plug disposed within said cylinder adjacent the head end thereof and having integrally formed inner and outer cylindrical portions, the diameter of said inner portion being substantially the same as said internal diameter of the cylinder to fit snugly within the cylinder, said inner portion having an annular groove formed in the periphery thereof, a ring of resilient material seated in said groove and bearing against the inside of said wall to form a seal between said plug and said cylinder, and a plurality of sharp elongated teeth formed around the periphery of said outer portion of said plug and extending generally longitudinally thereof, the outer diameter of said teeth being greater than said internal diameter of said cylinder and smaller than said external diameter thereof whereby said teeth bite into the wall of the cylinder and hold said plug in a fixed position relative to the cylinder.

2. A construction as defined by claim 1 in which the root diameter of said teeth is no greater than said internal diameter of the cylinder.