Adjustable dry friction shock absorber
First Claim
1. A shock absorber comprising a casing having an internal surface, a piston, an external surface of low coefficient of friction bearing material on said piston, said external surface being in contiguous relationship with said internal surface, means for moving said piston in first and second opposite directions relative to said casing, actuating means for applying a biasing force tending to move said external surface outwardly toward said internal surface to increase the friction therebetween to provide a shock absorbing action when a first force is applied to said shock absorber for moving said piston in said first direction and for relieving said biasing force to decrease the friction therebetween when a second force is applied to said shock absorber for moving said piston in said same direction, adjustment means for adjusting said biasing force, said piston comprising an elongated member having first and second piston end portions, a hollow portion at said first piston end portion, a bore in said elongated member extending between said hollow portion and said second piston end portion, a rod slidably mounted in said bore, first and second rod end portions on said rod, said first rod end portion extending into said hollow portion, said second rod end portion extending outwardly beyond said second piston end portion, said actuating means being mounted on said first rod end portion within said hollow portion, said actuating means including varying means for varying said biasing force depending on the amount of travel of said first rod end portion into said hollow portion, a fitting adjustably mounted on said second rod end portion, a fitting end on said fitting spaced from said second piston end portion to define a clearance therebetween and for engaging said second piston end portion upon movement of said rod in said first direction for producing said biasing force and said adjustment means for adjusting said biasing force comprising means for adjusting the distance between said fitting end and said second piston end portion to thereby control the limit of travel of said varying means into said hollow portion as determined by the ultimate engagement between said fitting end and said second piston end portion.
2 Assignments
0 Petitions
Accused Products
Abstract
A dry friction shock absorber including a casing having an internal surface, a piston of low coefficient of friction bearing material having an external surface in contiguous relationship with the internal surface of the casing, attachment fittings on the piston and the casing for moving the piston into the casing when the shock absorber is subjected to shock forces, and expanding structure within the piston for tending to move the external surface of the piston outwardly toward the internal surface of the casing to increase the friction therebetween when the shock absorbing force is applied to the shock absorber for moving the piston into the casing. Adjustment structure is provided for varying the expanding force on the piston. A shock absorber of the foregoing type wherein the expanding structure is not activated when the piston moves slowly relative to the casing but which produces an expanding force on the piston when the shock absorber is subjected to shock forces both in tension and compression.
-
Citations
23 Claims
-
1. A shock absorber comprising a casing having an internal surface, a piston, an external surface of low coefficient of friction bearing material on said piston, said external surface being in contiguous relationship with said internal surface, means for moving said piston in first and second opposite directions relative to said casing, actuating means for applying a biasing force tending to move said external surface outwardly toward said internal surface to increase the friction therebetween to provide a shock absorbing action when a first force is applied to said shock absorber for moving said piston in said first direction and for relieving said biasing force to decrease the friction therebetween when a second force is applied to said shock absorber for moving said piston in said same direction, adjustment means for adjusting said biasing force, said piston comprising an elongated member having first and second piston end portions, a hollow portion at said first piston end portion, a bore in said elongated member extending between said hollow portion and said second piston end portion, a rod slidably mounted in said bore, first and second rod end portions on said rod, said first rod end portion extending into said hollow portion, said second rod end portion extending outwardly beyond said second piston end portion, said actuating means being mounted on said first rod end portion within said hollow portion, said actuating means including varying means for varying said biasing force depending on the amount of travel of said first rod end portion into said hollow portion, a fitting adjustably mounted on said second rod end portion, a fitting end on said fitting spaced from said second piston end portion to define a clearance therebetween and for engaging said second piston end portion upon movement of said rod in said first direction for producing said biasing force and said adjustment means for adjusting said biasing force comprising means for adjusting the distance between said fitting end and said second piston end portion to thereby control the limit of travel of said varying means into said hollow portion as determined by the ultimate engagement between said fitting end and said second piston end portion.
- 2. A shock absorber comprising a casing having an internal surface, a piston, an external surface of low coefficient of friction bearing material on said piston, said external surface being in contiguous relationship with said internal surface, means for moving said piston in first and second opposite directions relative to said casing, actuating means for applying a biasing force for moving said external surface outwardly toward said internal surface to produce friction therebetween during movement of said piston in at least one of said first and second opposite directions to thereby produce a shock absorbing action, and adjustment means for causing said actuating means to produce selectively variable predetermined maximum amounts of frictional engagement between said internal and external surfaces when said actuating means apply said biasing force for moving said external surface outwardly during movement of said piston in one of said first and second directions.
- 8. A shock absorber comprising a casing having an internal surface, a piston, an external surface of low coefficient of friction bearing material on said piston, said external surface being in contiguous relationship with said internal surface, means for moving said piston in first and second opposite directions relative to said casing, actuating means for applying a biasing force tending to move said external surface outwardly toward said internal surface to increase the friction therebetween to provide a shock absorbing action when a first force is applied to said shock absorber for moving said piston in said first direction and for relieving said biasing force to decrease the friction therebetween when a second force is applied to said shock absorber for moving said piston in said second direction, said piston comprising an elongated member having first and second piston end portions, a hollow portion at said first piston end portion, a bore in said elongated member extending between said hollow portion and said second piston end portion, a rod slidably mounted in said bore, first and second rod end portions on said rod, said first rod end portion extending into said hollow portion, said second rod end portion extending outwardly beyond said second piston end portion, said actuating means being mounted on said first rod end portion within said hollow portion, said actuating means including engaging means mounted on said second rod end portion and normally spaced from said second piston end portion to define a clearance therebetween when said piston is not being moved in said first direction and for engaging said second piston end portion upon movement of said rod in said first direction for providing said shock absorbing action, said clearance between said engaging means and said second piston end portion thereby controlling the limit of travel of said actuating means into said hollow portion during movement of said piston in said first direction as determined by the ultimate engagement between said engaging means and said second piston end portion to thereby control the amount of frictional engagement between said internal and external surfaces, and means for varying said clearance to produce different magnitudes of shock absorbing action.
- 16. A shock absorber comprising a casing having an internal surface, a piston, an external surface of low coefficient of friction bearing material on said piston, said external surface being in contiguous relationship with said internal surface, means for moving said piston in first and second opposite directions relative to said casing, actuating means for applying a biasing force tending to move said external surface outwardly toward said internal surface to increase the friction therebetween to provide a shock absorbing action when a first force is applied to said shock absorber for moving said piston in said first direction for relieving said biasing force to decrease the friction therebetween when a second force is applied to said shock absorber for moving said piston in said second direction, and adjustment means for adjusting the maximum value of said biasing force which is experienced when said actuating means apply said first force to move said external surface outwardly.
Specification